KR101669807B1 - Positive Mix Paste For Lithium Secondary Battery - Google Patents

Abstract

In the positive electrode material mixture paste for a lithium secondary battery, stabilization of dispersion can be achieved without impeding the conductivity of the positive electrode active material, the binding force between the battery material powder and the binder component can be improved, and the paste prepared using such a paste as an electrode material And to improve the battery performance of the battery. A positive electrode for a lithium secondary battery, comprising a positive electrode active material, a dispersing agent comprising at least one compound selected from the group consisting of an organic compound having a basic functional group and an organic compound having an acidic functional group, and optionally a solvent and a binder Mixed paste is prepared and used.

Description

[0001] The present invention relates to a positive mix paste for a lithium secondary battery,

The present invention relates to a positive electrode material mixture paste used for producing a positive electrode constituting a lithium secondary battery and a manufacturing method thereof. The present invention also relates to a lithium secondary battery having excellent discharge characteristics or charging characteristics in a large current, cycle characteristics, and conductivity of an electrode mixture, and having an electrode having a small contact resistance with an electrode current collector and an electrode material mixture.

Recently, small portable electronic devices such as digital cameras and cellular phones are widely used. In the field of small portable electronic devices, it is always required to minimize the volume of the device and lighten the device. For this reason, realization of a small-sized, light-weight, and large-capacity battery is also required for a battery mounted on an apparatus. In the field of large secondary batteries such as automobiles, realization of a large non-aqueous electrolyte secondary battery has been demanded in place of conventional lead acid batteries.

Under these circumstances, in the field of battery technology, development of a lithium secondary battery has been actively carried out in order to meet the above-mentioned demand. Examples of the electrode of the lithium secondary battery include a positive electrode obtained by fixing an electrode mixture composed of a positive electrode active material containing lithium ions, a conductive auxiliary agent, and an organic binder to the surface of a current collector of a metal foil and a negative electrode active material capable of deintercalating lithium ions, A negative electrode obtained by fixing an electrode mixture made of a binder or the like to the surface of a collector of a metal foil is used.

In general, as the positive electrode active material, lithium transition metal composite oxides such as lithium cobalt oxide, lithium manganese oxide and lithium nickel oxide can be used. However, they have low electronic conductivity and can not obtain sufficient battery performance when used alone. Therefore, attempts have been made to improve the conductivity and reduce the internal resistance of the positive electrode by adding a carbon material such as carbon black (for example, acetylene black) as a conductive auxiliary agent. Further, in order to efficiently reduce the internal resistance with a smaller amount of carbon black, it is necessary that both the positive electrode active material and the carbon material as the conductive additive are uniformly mixed at a finer level in the electrode. Particularly, the reduction of the internal resistance of the electrode is very important from the viewpoint of enabling discharging at a large current or improving efficiency of charging / discharging.

However, since the properties of the particle surface of the carbon material such as the positive electrode active material having high hydrophilicity and the carbon black having high hydrophobicity are greatly different from each other, it is difficult to uniformly disperse and mix the carbon material uniformly in the positive electrode material mixture paste. If both are not uniformly dispersed and mixed, the performance of the positive electrode active material and the carbon material as the conductive additive can not be maximized and the performance of the battery can not be improved. In addition, if the dispersion of the positive electrode active material and the conductive auxiliary in the positive electrode mixture is insufficient, aggregation tends to occur partially. When agglomeration occurs, a resistance distribution is generated on the electrode plate, and currents are concentrated when used as a battery, and partial heat generation and deterioration are promoted in some cases.

When the positive electrode mixture layer is formed on the current collector such as a metal foil, if the charging and discharging are repeated a plurality of times, the adhesion between the positive electrode mixture layer and the positive electrode active material in the positive electrode mixture mixture and the interface between the positive electrode active material and the conductive auxiliary agent And the battery performance tends to deteriorate. This is because the positive electrode active material and the positive electrode material mixture layer repeatedly expand and contract due to the doping and dedoping of lithium ions in charge and discharge, and therefore the interface between the positive electrode material mixture layer and the current collector and the local shearing at the interface between the positive electrode active material and the conductive auxiliary agent It is thought that the stress is generated and the adhesion of the interface is lowered. Such deterioration of the adhesion is more remarkable when the dispersion of the positive electrode active material and the conductive auxiliary agent is insufficient. This is considered to be because the dispersion of the positive electrode active material and the conductive auxiliary agent is insufficient and the presence of coarse aggregated particles makes it difficult for the stress at the interface to be relaxed.

In the technical field of the lithium secondary battery, it is one of important points to increase the dispersibility of the active material and the carbon material, which is a conductive additive, and various investigations have been made. For example, Patent Documents 1 and 2 disclose a technique of using a surfactant as a dispersant when dispersing an active material and carbon black in a solvent. However, since the surfactant has weak adsorption ability to the particle surface, it is necessary to add a large amount of surfactant in order to obtain good dispersion stability. As a result, the amount of the active material that can be contained in the electrode material decreases, and the battery capacity tends to decrease. Further, if the adsorption of the surfactant to the particles is insufficient, the active material or the carbon material tends to easily aggregate. Further, in general surfactants, the dispersing effect in an organic solvent tends to be remarkably low as compared with a dispersion in an aqueous solution.

On the other hand, Patent Document 3 discloses a method for improving the dispersion state by adding a dispersion resin when dispersing the negative electrode active material and the carbon black in water. However, this method improves the dispersibility of the active material and the carbon black, but the dispersion resin having a high molecular weight tends to coat the particle surface. As a result, the conductive network is liable to be hindered and the resistance of the electrode is increased, which may in turn cancel out the effect of improving the dispersion of the active material and the carbon black.

Further, in the technical field of lithium secondary batteries, improvement of the wettability of the electrode to the electrolyte is an important point for improving the dispersibility of the electrode material and improving the charging / discharging efficiency. Since the electrode reaction occurs at the contact interface between the surface of the electrode material and the electrolyte, it is important that the electrolyte penetrates into the inside of the electrode and the electrode material is well wetted. A method of increasing the surface area of an electrode using a fine active material or a conductive additive has been studied as a method of promoting the electrode reaction. However, since the wettability to the electrolyte is poor, the actual contact area is difficult to increase and battery performance is difficult to improve.

As a method for improving the wettability of the electrode, Patent Document 4 discloses a method for improving the wettability by adsorbing a surfactant such as a higher fatty acid alkali salt to a negative electrode active material and a carbon powder. However, as described above, the surfactant in particular is not sufficient in dispersibility in non-aqueous systems in many cases, and it is difficult to obtain a uniform electrode coating film. Thus, all of the conventional methods are insufficient for realizing the comprehensive performance improvement including the dispersibility of the electrode material, and further development is required.

Japanese Patent Application Laid-Open No. 63-236258 Japanese Patent Application Laid-Open No. 8-190912 Specification No. 2006-516795 Japanese Patent Application Laid-Open No. 6-60877

The present invention relates to a positive electrode material mixture paste capable of stabilizing dispersion without inhibiting the conductivity of a positive electrode active material favorable to an electrode material for a lithium secondary battery and capable of improving the wettability of the positive electrode active material to an electrolyte, The present invention provides a lithium secondary battery having improved battery performance by using a material.

As a result of intensive studies on the positive electrode material for a lithium secondary battery in view of the above circumstances, the inventors have found that an organic dye derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, An organic pigment derivative having an acidic functional group, a triazine derivative having an acidic functional group, a resin having a basic functional group, and a resin having an acidic functional group are appropriately selected and used so that the dispersibility and wettability of the positive electrode active material The present invention has been completed.

That is, the present invention is characterized by the matters described in the following (1) to (19).

(1) A positive electrode material mixture paste for a lithium secondary battery, comprising a positive electrode active material, a dispersant comprising at least one compound selected from the group consisting of an organic compound having an acidic functional group and an organic compound having a basic functional group.

(2) the dispersant contains at least one organic pigment derivative having an organic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, and a triazine derivative having a basic functional group (1). ≪ / RTI >

(3) The positive electrode material mixture paste for a lithium secondary battery according to (1) or (2), wherein the dispersant comprises a resin having an acidic functional group.

(4) the dispersant is at least one compound selected from the group consisting of an organic pigment derivative having an organic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, and a triazine derivative having a basic functional group, The positive electrode material mixture paste for a lithium secondary battery according to the above (1), which comprises a resin having a basic functional group.

(5) The resin having an acidic functional group

(H1) polyvinylidene fluoride resin having an acidic functional group,

(A) having two hydroxyl groups at one terminal and obtained by radical polymerization of the ethylenically unsaturated monomer (m) in the presence of a compound (s) having two hydroxyl groups and one thiol group in the molecule (H2) ) Obtained by reacting the above hydroxyl group with an acid anhydride group in an anhydride (b) with a tetracarboxylic acid and

(H3) polyester resin represented by the following general formula

(HOOC-) _m -R ²¹ - (-COO- [-R ²³ -COO-] _n -R ²² ) _t

(Wherein,

R ²¹ is a tetravalent tetracarboxylic acid compound residue, R ²² is a monoalcohol residue,

R ²³ is a lactone residue, m is 2 or 3, n is an integer of 1 to 50, and t is (4-m).

(3) above, wherein the positive electrode material mixture is at least one selected from the group consisting of a positive electrode material and a negative electrode material.

(6) The positive electrode material mixture paste for a lithium secondary battery according to (1), wherein the dispersant comprises at least one derivative selected from the group consisting of an organic colorant derivative having an acidic functional group and a triazine derivative having an acidic functional group.

(7) The positive electrode material mixture paste for a lithium secondary battery according to the above (1) or (6), wherein the dispersant comprises a resin having a basic functional group.

(8) The resin having a basic functional group

(Urethane prepolymer having an isocyanate group at both ends thereof obtained by the reaction of the hydroxyl group and the isocyanate group in the diisocyanate (B1) in the vinyl polymer (A1) having two hydroxyl groups at one terminal region of the terminal (G1) (C1) and the isocyanate group

A polymer having an amine value of 1 to 100 mgKOH / g obtained by a reaction of at least one amino group selected from the group consisting of a primary amino group and a secondary amino group in an amine compound containing at least a polyamine (D1)

(Meth) acryloyl group in the polymer (A2) having one or two (meth) acryloyl groups in the terminal end region of the (G2) terminal group and at least one kind selected from the group consisting of a primary amino group and a secondary amino group The amino group-containing primary and / or secondary amino group in the polymer (C2) having an amino group obtained by the reaction with the amino group in the polyamine (B2)

The isocyanate group in the polyisocyanate (D2) having two or more isocyanate groups

And a polymer having an amine value of 5 to 100 mgKOH / g, which is obtained by the reaction of the above-mentioned (A) and (B).

(9) The polymer (A1) in which the vinyl polymer (A1) having two hydroxyl groups in the one terminal region in the polymer (G1) is a polymer having a hydroxyl group and a thiol group in the molecule The positive electrode material mixture paste for a lithium secondary battery according to (8), which is a polymer obtained by radical polymerization of an unsaturated monomer (a12).

(10) The polymer according to (8) or (9) above, wherein the polymer (A2) having one or two (meth) acryloyl groups in the one terminal region in the polymer (G2) Positive electrode compound paste for lithium secondary battery.

(11) The positive electrode material mixture paste for a lithium secondary battery according to any one of (1) to (10), further comprising a binder component different from the dispersant.

(12) The positive electrode material mixture paste for a lithium secondary battery according to (11), wherein the binder component is a polymer compound having a fluorine atom in a molecule.

(13) The positive electrode material mixture paste for a lithium secondary battery according to any one of (1) to (12), wherein the positive electrode active material is lithium iron phosphate.

(14) The positive electrode material mixture paste for a lithium secondary battery according to any one of (1) to (13), further comprising a conductive auxiliary agent.

(15) The positive electrode material mixture paste for a lithium secondary battery according to any one of (1) to (14), further comprising a solvent.

(16) an organic pigment derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, a triazine derivative having a basic functional group, an organic pigment derivative having an acidic functional group, A conductive auxiliary agent, and a binder component different from the dispersing agent in a solvent, wherein the dispersing agent comprises at least one organic derivative selected from the group consisting of an organic solvent and a derivative.

(17) An organic pigment derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, a triazine derivative having a basic functional group, an organic coloring matter derivative having an acidic functional group, A step of forming a dispersion by dispersing a positive electrode active material and a dispersing agent comprising at least one organic derivative selected from the group consisting of an organic solvent and a derivative; and a step of mixing the dispersion, the conductive additive and a binder component different from the organic compound Wherein the positive electrode mixture paste for lithium secondary battery is produced by a method comprising the steps of:

(18) an organic pigment derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, a triazine derivative having a basic functional group, an organic coloring matter derivative having an acidic functional group, Wherein the positive electrode active material is surface-treated with a dispersing agent comprising at least one organic derivative selected from the group consisting of an organic solvent and a derivative.

(19) A lithium secondary battery comprising a positive electrode having a positive mixture layer on a first current collector, a negative electrode having a negative electrode mixture layer on the second current collector, and lithium interposed between the positive mixture layer and the negative- 1. A lithium secondary battery having an electrolyte, wherein the positive electrode material mixture layer is formed using the positive electrode material mixture paste for a lithium secondary battery according to any one of (1) to (15).

This application is also related to Japanese Patent Application No. 2008-196637 filed on July 30, 2008 by the same applicant and Japanese Patent Application No. 2008-220564 filed on August 28, 2008 , Which are incorporated herein by reference in their entirety.

According to the present invention, it is possible to provide a positive electrode material mixture paste for a lithium secondary battery which is excellent in dispersion stability without inhibiting the conductivity of the positive electrode active material. Further, by using the positive electrode material mixture paste for a lithium secondary battery according to the present invention in the positive electrode of a lithium secondary battery, the positive electrode active material is uniformly mixed at the primary particle level in the positive electrode material mixture to improve the adhesion between the current collector and the positive electrode material mixture, And the wettability of the positive electrode material mixture with respect to the electrolyte solution can be improved. As a result, reduction of the internal resistance of the positive electrode can be promoted, charge and discharge efficiency can be improved, and battery performance can be improved comprehensively.

1 is a schematic sectional view showing one embodiment of a lithium secondary battery according to the present invention.

≪ Positive electrode composite paste for lithium secondary battery >

The positive electrode material mixture paste for a lithium secondary battery according to the present invention is characterized by including a positive electrode active material, a dispersing agent containing at least one compound selected from the group consisting of a compound having a basic functional group and an organic compound having an acidic functional group. The positive electrode material mixture paste may contain various components known in the technical field such as a conductive additive, a solvent, and a binder as needed. In the present invention, it is possible to provide a customary electrode material having improved dispersibility and wettability of the positive electrode active material by using a specific organic compound as a dispersant. Hereinafter, each component constituting the positive electrode material mixture paste will be described in detail.

(Positive electrode active material)

The positive electrode active material usable in the present invention is not particularly limited and may be a compound commonly used in the technical field of lithium secondary batteries. For example, metal compounds such as metal oxides and metal sulfides capable of doping or intercalating lithium ions can be used. More specifically, inorganic compounds such as oxides of transition metals such as Ti, Fe, Co, Ni and Mn, complex oxides of the transition metal and lithium, and sulfides of the transition metal can be mentioned.

Specific examples of the inorganic compound usable as the positive electrode active material in the present invention include the following.

Transition metal oxide powders such as MnO, V ₂ O ₅ , V ₆ O ₁₃ and TiO ₂ ;

Composite oxide powders of lithium and a transition metal such as a layered structure of lithium nickel oxide, lithium cobaltate, lithium manganese oxide and lithium manganese oxide having a spinel structure;

An iron phosphate based material, which is a phosphoric acid compound having an olivine structure, and

Transition metal sulfide powder such as TiS ₂ and FeS.

These inorganic compounds may be used alone or in combination of two or more.

The specific surface area of the positive electrode active material used in the present invention is defined as the specific surface area (BET) which can be obtained from the adsorption amount of nitrogen. In the present invention, the specific surface area of the positive electrode active material is not particularly limited, and the larger the value is, the more the contact point between the positive electrode active material particles is increased, which is advantageous in lowering the internal resistance of the positive electrode. However, it is preferable that the specific surface area is 150 m < 2 > / g or less from the viewpoint of workability at the time of electrode production. From the standpoint of obtaining sufficient conductivity, the specific surface area is preferably 0. 2 m 2 / g or more. In one embodiment of the present invention, the specific surface area of the positive electrode active material is 0.1 m 2 / g or more and 150 m 2 / g or less, preferably 1 m 2 / g or more and 120 m 2 / g or less, G / g or less.

The particle size of the positive electrode active material used in the present invention is preferably 0.01 to 500 μm, more preferably 0.05 to 100 μm, in terms of the primary particle size. Note that the " primary particle diameter " described in this specification means a value obtained by averaging the particle diameters measured by an electron microscope or the like.

Of the inorganic compounds exemplified above as the positive electrode active material, lithium iron phosphate having an olivine structure is a preferable material from the viewpoint of cost and safety.

In general, when a lithium iron phosphate material having an olivine structure is used as a positive electrode active material, the electron conductivity is very low as compared with materials such as lithium cobalt oxide, and it is difficult to obtain excellent battery characteristics. Therefore, when the above-mentioned iron phosphate material is used, a method of supporting a conductive material such as a carbon material on the particles and a method of reducing the primary particle diameter of the material are applied to improve the electronic conductivity.

The lithium iron phosphate material in which the carbon material is supported as described above can be easily manufactured by applying a method well known in the art. As the method for producing the iron phosphate lithium material, for example, the methods disclosed in JP-A-2003-292308 and JP-A-2003-292309 can be applied. Are incorporated herein by reference in their entirety.

An example of a method for producing the iron phosphate lithium material is as follows. First, ferrous phosphate monohydrate (Fe ₃ (PO ₄ ) ₂ .8H ₂ O) and lithium phosphate (Li ₃ PO ₄ ) are mixed so that the element ratio of lithium and iron is 1: 1. Next, a carbon material (for example, acetylene black, ketjen black or the like) as a conductive material or an organic compound decomposed at the time of firing to become a carbon material is added to this mixture, followed by pulverizing and mixing treatment with a dry mill or the like . Then, the treated material is calcined at 600 DEG C for several hours in an inert gas atmosphere, and the calcined material is pulverized to obtain a desired material. In addition, the carbon material or the organic compound to be added as the conductive material is adjusted so that the carbon material component in the final product is 0.1 to 50 wt%.

(Dispersant)

In the positive electrode material mixture paste according to the present invention, at least one organic compound selected from the group consisting of an organic compound having a basic functional group and an organic compound having an acidic functional group is used as a dispersing agent. The above-described specific organic compound not only enhances the dispersibility of the material particles such as the positive electrode active material and the conductive auxiliary agent added as needed, but also can function as a good binder itself. However, the organic compound used as a dispersant in the present invention is distinguishable from a binder described later. According to the present invention, by using a specific organic compound as a dispersant, it is possible to provide a positive electrode material mixture paste excellent in dispersion stability without deteriorating conductivity. In addition, the positive electrode material mixture paste according to the present invention not only exhibits excellent dispersibility but also can improve the adhesion between the current collector and the positive electrode material mixture, the adhesion between the positive electrode active material and the conductive auxiliary agent, and the wettability of the positive electrode material mixture with the electrolyte, It is well-known as the positive electrode material of the battery.

The basic functional group or organic compound having an acidic functional group which can be used as a dispersant in the present invention is not particularly limited as long as it can act on or adsorb on the surface of the positive electrode active material by these functional groups. However, examples of organic compounds having basic functional groups that are important from the viewpoint of cell performance in which electronic conductivity is important include (I-1) organic dye derivatives having basic functional groups, anthraquinone derivatives having basic functional groups, A thiazine derivative having a basic functional group, and (I-2) a resin having a basic functional group. Examples of the organic compound having an acidic functional group include (II-1) an organic dye derivative having an acidic functional group and various derivatives such as a triazine derivative having an acidic functional group, (II-2) a resin having an acidic functional group .

In a preferred embodiment of the present invention, the dispersant contains any one of the derivative (I-1) having the basic functional group and the derivative (II-1) having the acid functional group as essential components. In another preferred embodiment of the present invention, the dispersing agent comprises any one of the resin (I-2) having a basic functional group and the resin (II-2) having an acid functional group as essential components. In another preferred embodiment of the present invention, the dispersant further comprises a resin (I-2) having the basic functional group in addition to the various derivatives (I-1) or (II- 2). Hereinafter, each of the organic compounds will be described in detail.

I-1. Various derivatives having basic functional groups

Various derivatives having a basic functional group include an organic pigment derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, and a triazine derivative having a basic functional group .

In particular, it is preferable to use a triazine derivative represented by the following general formula (1) or an organic coloring matter derivative represented by the following general formula (6).

In the above general formula (1)

X ¹ is -NH-, -O-, -CONH-, -SO ₂ NH-, -CH ₂ NH-, -CH ₂ NHCOCH ₂ NH- or -X ² -Y ¹ -X ³ -

X ² is -NH-, -O-, -CONH-, -SO ₂ NH-, -CH ₂ NH-, -NHCO- or -NHSO ₂ -

X ³ are each independently -NH- or -O-,

Y ¹ is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group or a substituted or unsubstituted arylene group,

P is a substituent represented by any one of the following general formulas (2), (3) and (4)

Q is a substituent represented by any one of -OR ² , -NH-R ² , a halogen group, -X ¹ -R ¹ or the following general formula (2), (3)

R ² is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group or a substituted or unsubstituted aryl group,

R ¹ is an organic dye residue, a substituted or unsubstituted heterocyclic residue, a substituted or unsubstituted aromatic ring residue, or a group represented by the following formula (5)

n ¹ is an integer of 1 to 4;

In the above general formulas (2) to (4)

X ⁴ is a direct bond, -SO ₂ -, -CO-, -CH ₂ NHCOCH ₂ -, -CH ₂ NHCONHCH ₂ -, -CH ₂ - or -X ⁵ -Y ² -X ⁶ -

X ⁵ is -NH- or -O-,

X ⁶ is a direct bond, -SO ₂ -, -CO-, -CH ₂ NHCOCH ₂ -, -CH ₂ NHCONHCH ₂ - or -CH ₂ -

Y ² is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group or a substituted or unsubstituted arylene group,

v is an integer of 1 to 10,

R ³ and R ⁴ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or R ³ and R ⁴ are monosubstituted, A substituted or unsubstituted heterocyclic residue containing a sulfur atom,

R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group or a substituted or unsubstituted aryl group,

R ⁹ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group or a substituted or unsubstituted aryl group.

In the above general formula (5)

T is -X ⁸ -R ¹⁰ or W ^1,

U is -X ⁹ -R ¹¹ or W ^2,

W ¹ and W ² are each independently -OR ²⁰ , -NH-R ²⁰ , a halogen group or a substituent represented by any one of the general formulas (2), (3) and (4)

R ²⁰ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group or a substituted or unsubstituted aryl group,

X ⁷ is -NH- or -O-,

X ⁸ and X ⁹ are each independently -NH-, -O-, -CONH-, -SO ₂ NH-, -CH ₂ NH- or -CH ₂ NHCOCH ₂ NH-,

Y ³ is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group or a substituted or unsubstituted arylene group,

R ¹⁰ and R ¹¹ are each independently an organic pigment residue, a substituted or unsubstituted heterocyclic residue, or a substituted or unsubstituted aromatic ring residue.

Specific examples of the organic dye residue represented by R ^{1 in} the general formula (1) and R ¹⁰ and R ¹¹ in the general formula (5) include a diketopyrrolopyrrole dye; Azo dyes such as azo, disazo and polyazo; Phthalocyanine dye; Anthraquinone type pigments such as diaminodianthraquinone, anthrapyrimidine, flavanthrone, anthanthrone, indanthrone, pyranthrone and biorantrone; A quinacridone dye, a dioxazine dye, a perinone dye, a perylene dye, Thioindigo dye; Isoindoline dye; Isoindolinone dye; Quinophthalone-based coloring matter; Threne-based coloring matter; And metal complex system pigments. In particular, from the viewpoint of enhancing the effect of suppressing shorting of the battery by the metal, it is preferable to use an organic dye residue rather than a metal complex dye.

Specific examples of the heterocyclic residue and the aromatic ring residue represented by R ^{1 in} the general formula (1) and R ¹⁰ and R ¹¹ in the general formula (5) include thiophene, furan, pyridine, pyrazine, triazine, The present invention relates to a process for the preparation of a compound of the formula I wherein R 1 is selected from the group consisting of a benzene ring, a pyrrole, a pyrrole, an imidazole, an isoindoline, an isoindolinone, a benzimidazolone, a benzothiazole, a benztriazole, an indole, a quinoline, a carbazole, an acridine, Threne, anthraquinone, and acridone. These heterocyclic residues and aromatic ring residues may be substituted with at least one substituent selected from the group consisting of an alkyl group (methyl group, ethyl group and butyl group), an amino group, an alkylamino group (dimethylamino group, diethylamino group and dibutylamino group), a nitro group, (Which may be substituted with an alkyl group, an amino group, an alkylamino group, a nitro group, a hydroxyl group, an alkoxy group or a halogen atom), and a phenylamino group (Which may be substituted with an alkyl group, an amino group, an alkylamino group, a nitro group, a hydroxyl group, an alkoxy group or a halogen).

R ³ and R ⁴ in the general formulas (2) and (3) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or R ³ and R ⁴ is a heterocyclic residue which may be monosubstituted and may further have a substituent including a nitrogen, oxygen or sulfur atom.

Y ¹ , Y ² and Y ³ in the general formulas (1) to (5) independently represent a substituted or unsubstituted alkylene, alkenylene or arylene group having 20 or less carbon atoms, A substituted phenylene group, a biphenylene group, a naphthylene group or an alkylene group which may have a side chain of not more than 10 carbon atoms.

In the general formula (6)

Z is at least one selected from the group consisting of the following formulas (7), (8) and (9), n ² is an integer of 1 to 4, R ¹² is an organic dye residue, Or a substituted or unsubstituted aromatic residue.

In the above general formulas (7) to (9)

X ¹⁰ is a direct bond, -SO ₂ -, -CO-, -CH ₂ NHCOCH ₂ -, -CH ₂ NHCONHCH ₂ -, -CH ₂ - or -X ¹¹ -Y ⁴ -X ¹² -

X ¹¹ is -NH- or -O-,

X ¹² is a direct bond, -SO ₂ -, -CO-, -CH ₂ NHCOCH ₂ -, -CH ₂ NHCONHCH ₂ - or -CH ₂ -

Y ⁴ is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group or a substituted or unsubstituted arylene group,

v ¹ is an integer of 1 to 10,

R ¹³ and R ¹⁴ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted phenyl group, or R ¹³ and R ¹⁴ are monosubstituted and further substituted with nitrogen, oxygen or sulfur A substituted or unsubstituted heterocyclic residue containing an atom,

R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group or a substituted or unsubstituted aryl group,

R ¹⁹ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group or a substituted or unsubstituted aryl group.

Specific examples of the organic dye residue represented by R ¹² in the general formula (6) include a diketopyrrolopyrrole dye; Azo dyes such as azo, disazo and polyazo; Phthalocyanine dye; Anthraquinone type pigments such as diaminodianthraquinone, anthrapyrimidine, flavanthrone, anthanthrone, indanthrone, pyranthrone and biorantrone; A quinacridone dye; Dioxazine-based coloring matter; Perinone pigment; Perylene dye; Thioindigo dye; Isoindoline dye; An isoindolinone dye; a quinophthalone dye; Threne-based coloring matter; And metal complex system pigments. In particular, in order to enhance the effect of suppressing short-circuiting of the battery due to metal, it is preferable to use an organic dye residue rather than a metal complex dye.

Examples of the heterocyclic residue and the aromatic ring residue represented by R ¹² in the general formula (6) include thiophene, furan, pyridine, pyrazole, pyrrole, imidazole, isoindoline, isoindolinone, There may be mentioned imidazolone, benzothiazole, benztriazole, indole, quinoline, carbazole, acridine, benzene, naphthalene, anthracene, fluorene, phenanthrene, anthraquinone and acridone. These heterocyclic residues and aromatic ring residues may be substituted with at least one substituent selected from the group consisting of an alkyl group (such as methyl, ethyl and butyl), an amino group, an alkylamino group (dimethylamino group, diethylamino group and dibutylamino group), a nitro group, (Which may be substituted with an alkyl group, an amino group, an alkylamino group, a nitro group, a hydroxyl group, an alkoxy group, a halogen, etc.), and a phenylamino group (May be substituted with an alkyl group, an amino group, an alkylamino group, a nitro group, a hydroxyl group, an alkoxy group, a halogen, etc.).

R ¹³ and R ¹⁴ in the formulas (7) and (8) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted phenyl group, or R ¹³ and R ¹⁴ are monovalent and further substituted or unsubstituted heterocyclic residues containing a nitrogen, oxygen or sulfur atom.

Specific examples of the amine component used for forming the substituent represented by the general formulas (2) to (4) and the general formulas (6) to (8) include the followings.

Dimethylamine, dimethylamine, diethylamine, methylethylamine, N, N-ethylisopropylamine, N, N-ethylpropylamine, N, N-methylbutylamine, N, N, N-sec-butylpropylamine, dibutylamine, di-sec-butylamine, diisobutylamine, N, N-diethylamine, N, N-dimethylaniline, N, N-dimethylaniline, N, N-dimethylaniline, N, N, N-dimethylaniline, N, N-dimethyl-aminomethylamine, N, N-dimethylaniline, Dimethylaminoethylamine, N, N-dimethylaminobutylamine, N, N-diethylaminoethylamine, N, N-diethylaminopropylamine, N, N-di Ethylaminohexylamine, N, N-diethylaminobutylamine, N, N-diethyl But are not limited to, aminopentylamine, N, N-dipropylaminobutylamine, N, N-dibutylaminopropylamine, N, N-dibutylaminoethylamine, N, N-diethylaminoethylamine, N, N-diureylaminoethylamine, N, N-diethylaminoethylamine, N, 2-piperolin, 3-piperolin, 4-piperolin, 2,4-lupetidine, 2,6-lupetidine, 3, But are not limited to, ethyl alcohol, isopropyl alcohol, isopropyl alcohol, isopropyl alcohol, isopropyl alcohol, isopropyl alcohol, isopropyl alcohol, isopropyl alcohol, isopropyl alcohol, Aminoethylpiperidine, N-aminoethylpiperidine, N-aminoethyl-4-piperolin, N-aminoethylmorpholine, N-aminopropylpiperidine, N-aminopropyl- -4-piperolin, N-aminopropylmorpholine, N-methylpiperazine, N-butylpiperazine, N-methyl homopiperazine, 1-cyclopentylpiperazine, 1-amino-4-methylpiperazine and 1-cyclopentylpiperazine.

The method for synthesizing the organic pigment derivative having a basic functional group, the anthraquinone derivative having a basic functional group, the acridone derivative having a basic functional group or the triazine derivative having a basic functional group of the present invention is not particularly limited and a well-known method . For example, JP-A-54-62227, JP-A-56-118462, JP-A-56-166266, JP-A-60-88185, JP-A-63-305173, JP-A-3-2676 Or the method described in Japanese Patent Application Laid-Open No. 11-199796 can be applied. Are incorporated herein by reference in their entirety.

Various derivatives having a basic functional group can be synthesized, for example, by introducing a substituent represented by the following general formulas (10) to (13) into an organic dye, anthraquinone or acridone and then reacting the substituent with an amine component .

Examples of the amine component include N, N-dimethylaminopropylamine, N-methylpiperazine, diethylamine or 4- [4-hydroxy-6- [3- (dibutylamino) , 3,5-triazin-2-ylamino] aniline, and the like.

For example, when a substituent represented by the general formula (10) is introduced, an organic dye, anthraquinone or acridone is dissolved in chlorosulfonic acid and a chlorinating agent such as thionyl chloride is reacted. At this time, the number of substituents represented by the general formula (10) introduced into the organic dye, anthraquinone or acridone can be controlled by adjusting the conditions such as the reaction temperature and the reaction time.

When introducing a substituent represented by the general formula (11), an organic dye having an carboxyl group, anthraquinone or acridone is first synthesized by a known method, and then thionyl chloride or the like is added in an aromatic solvent such as benzene And a method of reacting a chlorinating agent of the formula

When the substituents represented by the general formulas (10) to (13) are reacted with the amine component, when a part of the substituents represented by the general formulas (10) to (13) is hydrolyzed and the chlorine is substituted with a hydroxyl group . In this case, the substituent represented by the general formula (10) becomes a sulfonic acid group, and the substituent represented by the general formula (11) becomes a carboxylic acid group. All of the acid groups may be free acid. Or may form a salt with a metal having 1 to 3 valences or a salt with the amine, respectively.

When the organic dye is an azo dye, the substituent represented by the general formulas (7) to (9) or (14) is introduced into the diazo component or the coupling component in advance and then the coupling reaction is carried out Whereby an azo-based organic dye derivative can be produced.

In the general formula (14)

X ¹³ is -NH-, -O-, -CONH-, -SO ₂ NH-, -CH ₂ NH-, -CH ₂ NHCOCH ₂ NH- or -X ¹⁴ -Y ⁵ -X ¹⁵ -

X ¹⁴ is -NH-, -O-, -CONH-, -SO ₂ NH-, -CH ₂ NH-, -NHCO- or -NHSO ₂ -

X < ¹⁵ > are each independently -NH- or -O-,

Y < ⁵ > is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group or a substituted or unsubstituted arylene group,

P ¹ is a substituent represented by any one of the general formulas (2), (3) and (4)

Q ² is a substituent represented by -OR ²⁴ , -NH-R ²⁴ , a halogen group, -X ¹ -R ^25, or any one of the general formulas (2), (3)

R ²⁴ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group,

R ²⁵ is an organic dye residue, a substituted or unsubstituted heterocyclic residue, a substituted or unsubstituted aromatic ring residue, or a group represented by the formula (5).

The triazine derivative having a basic functional group of the present invention can be obtained by using, for example, cyanuric chloride as a starting raw material and reacting at least one of the chlorines of the formula (7) to (9) or (14) (For example, N, N-dimethylaminopropylamine, N-methylpiperazine or the like) which reacts with the remaining chlorine of cyanuric chloride and various amines or alcohols .

One of the effects of the various derivatives having a basic functional group is considered to be that the added derivative acts on the surface of the positive electrode active material (for example, adsorption) to exhibit a dispersing effect. Among the positive electrode active materials, in the case of lithium iron phosphate bearing a carbon material, since the hydrophobicity of the surface of the particles is high, the adsorption action effect of various derivatives having basic functional groups is further improved and the dispersion effect is also expected to be further exerted.

That is, an organic pigment derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, or a triazine derivative having a basic functional group are completely dissolved or partially dissolved in a solvent to add a positive electrode active material to the solution (For example, adsorption) of these derivatives to the positive electrode active material proceeds, and the polarity of the basic functional groups of the derivative acting on the surface of the positive electrode active material (for example, adsorption) promotes wetting of the surface of the positive electrode active material on the solvent So that the agglomeration of the positive electrode active material is easily released.

In a preferred embodiment of the present invention, various derivatives having a basic functional group are used in combination with a resin (I-2) having a basic functional group described later. In another preferred embodiment of the present invention, various derivatives having a basic functional group are used in combination with an acidic compound. The acidic compound may be a resin (II-2) having an acidic functional group described later, or an inorganic acid described below or an organic acid having a molecular weight of 300 or less.

The dispersion stability of the positive electrode active material can be further enhanced by suitably combining a resin having a basic functional group or an acidic compound in addition to various derivatives having a basic functional group as in the above embodiment. In addition, since the resin having the acidic functional group or the resin having the basic functional group has improved adhesion with the positive electrode active material and the polymer compound having fluorine atom as the binder component, adhesion between the electrode current collector and the active material in the electrode material mixture will be improved I think.

Particularly, when a resin (I-2) having a basic functional group to be described later is used in combination, a basic functional group acts on (e.g., adsorbs) the surface of the positive electrode active material such as a derivative having the basic functional group, And the dispersion stability of the positive electrode active material is further increased by repulsion due to steric hindrance of the resin.

When resin (II-2) having an acidic functional group described below is used in combination with an acidic compound, the interaction between the acidic functional group and the basic functional group of the derivative (for example, acid-base interaction) It is considered that the adhesion with the resin component is improved and the dispersion stability of the positive electrode active material is further increased.

When an inorganic acid or an organic acid having a molecular weight of 300 or less is used as the acidic compound, the interaction between the acidic compound and the basic functional group of the derivative (for example, formation of an ion pair by neutralization (salt formation) (Polarization or dissociation of the ion pair (salt)) of the positive electrode active material, the electrostatic repulsion of the surface of the positive electrode active material is promoted and the dispersion stability of the positive electrode active material is further increased. Such an embodiment will be described in more detail below.

[Acidic compound: inorganic acid, organic acid having a molecular weight of 300 or less]

In the positive electrode material mixture paste for a lithium secondary battery of the present invention, an organic dye derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group and a triazine derivative having a basic functional group It is preferable to further add an acidic compound as a dispersion aid in order to obtain a good dispersion and dispersion stability of the positive electrode active material. The acidic compound used herein is not particularly limited, but various inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, organic acids such as carboxylic acids, phosphoric acids, and sulfonic acids may be used. Of these, it is preferable to use an acidic compound decomposing or volatilizing in the drying step at the time of electrode production, and it is preferable to use an organic acid having a molecular weight of 300 or less, preferably 200 or less. Further, it is preferable to use an acid having low reactivity with the positive electrode active material, and in particular, an organic acid, particularly a carboxylic acid, is preferable. Specific examples thereof include formic acid, acetic acid, fluoroacetic acid, propionic acid, butyric acid (butyric acid), oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, acrylic acid, , Maleic acid, fumaric acid, itaconic acid and citraconic acid.

These inorganic acids and organic acids having a molecular weight of 300 or less function with basic functional groups of an organic pigment derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group or a triazine derivative having a basic functional group, (Formation of salts) by neutralization and polarization or dissociation of ion pairs (salts). As a result, the solubility of the derivatives having these basic functional groups is improved, and at the same time, electrical interaction is induced on the surface of the positive electrode active material acting (for example, adsorbed) by the derivatives having these basic functional groups, so that the agglomeration of the positive active material It is thought to be promoted. Here, the interaction is, for example, an electrostatic repulsion between a cationic (cation) derived from a derivative having a basic functional group adsorbed on the surface of the positive electrode active material, an electrostatic repulsion by an electric double layer formed by dissociated acidion (anion) . Addition of these inorganic acids or organic acids having a molecular weight of 300 or less is also expected to suppress deterioration of the binder due to dehydrofluorination reaction by acidification of the system when a polyvinylidene fluoride binder described below is used.

As described above, in the embodiment of the present invention, by using a derivative having a basic functional group and preferably an inorganic acid or an organic acid having a molecular weight of 300 or less, a functional group is not directly introduced into the surface of the positive electrode active material (covalent bonding) And good dispersion can be obtained. As a result, good dispersion can be obtained without reducing the conductivity of the positive electrode active material. By using the positive electrode material mixture paste for a lithium secondary battery of the present invention in which the positive electrode active material is well dispersed, a positive electrode in which the positive electrode active material is uniformly dispersed can be produced.

As described above, when a positive electrode material mixture paste containing various derivatives having at least the basic functional group is prepared and a positive electrode is produced by using such a paste, a derivative having a basic functional group is present on the surface of the positive electrode active material. As a result, the positive electrode active material is uniformly dispersed and the wettability of the positive electrode to the electrolyte can be improved.

I-2. Resin having basic functional group

The compounded paste for a lithium secondary battery of the present invention may contain a resin having a basic functional group in order to obtain good dispersion and dispersion stability of the positive electrode active material. Preferred basic functional groups are primary, secondary and tertiary amino groups or amide groups. As the resin having a basic functional group, it is preferable to use at least one resin selected from the group consisting of three resins described below, that is, a polymer (G1), a polymer (G2) and a vinylamide resin from the viewpoint of dispersion stability desirable.

The resin having a basic functional group also functions as a binder for binding carbon materials used as an electrode active material and a conductive auxiliary agent to each other, or for bonding a carbon material used as an electrode active material and a conductive auxiliary agent to an electrode current collector. Such a resin having a basic functional group may be at least one compound (II-1) selected from the group consisting of various derivatives (II-1) having an acidic functional group, that is, an organic colorant derivative having an acidic functional group and a triazine derivative having an acidic functional group x "), the dispersion stability of the carbon material and the adhesion of the electrode mixture layer can be improved.

In the above-described embodiment, the acidic functional group of the derivative having an acidic functional group (for example, adsorbed on the surface of the carbon material) interacts with the basic functional group of the resin having a basic functional group (for example, acid-base interaction). Or a derivative having an acidic functional group and a resin having a basic functional group interact (for example, acid-base interaction), and adsorbed on the surface of the carbon material. As a result, in the above-described embodiment, the adsorption of the resin having a basic functional group to the surface of the carbon material is promoted, so that the adhesion between the carbon material and the resin component is improved, and the dispersion stability of the carbon material is improved by repulsion due to the steric hindrance of the resin . Further, adhesion between the carbon material and a binder component such as a polymer compound containing a fluorine atom in the molecule is also improved, so that it is expected that the amount of the binder component to be used decreases. Hereinafter, three kinds of resin, polymer (G1), polymer (G2) and vinylamide resin which can be suitably used in the present invention as specific examples of the resin having a basic functional group will be described.

≪ Polymer (G1) having basic functional group >

The polymer (G1) having a basic functional group which can be used in the present invention is a polymer having a hydroxyl group of a vinyl polymer (A1) having two hydroxyl groups in one terminal region and an isocyanate group of a diisocyanate (B1) Is reacted with a primary and / or secondary amino group of an isocyanate group, a polyamine (D1) and a monoamine (E1) of an isocyanate group-containing urethane prepolymer (C1).

The vinyl polymer moiety grafted to the side chain derived from the vinyl polymer (A1) has excellent affinity with the pigment carrier and the dispersion medium over a wide range, and functions on the solvent-affinitive part. The urea bonding site of the main chain has an organic functional group Derivatives, or triazine derivatives having an acidic functional group, and functions as an adsorbent to the surface of the pigment that is biased toward acid through the derivative. Further, an amino group may be introduced into the main chain for further improving the adsorptivity.

Hereinafter, each component of the polymer (G1) having a basic functional group will be described.

(Vinyl polymer (A1) having two hydroxyl groups in one terminal region)

The vinyl polymer (A1) having two hydroxyl groups in one end terminal region (hereinafter sometimes abbreviated as vinyl polymer (A1)) may be a compound having two hydroxyl groups and one thiol group in the molecule can be obtained by radical polymerization of the ethylenically unsaturated monomer (a12) in the presence of the monomer (a11). The vinyl polymer moiety of the vinyl polymer (A1) is a moiety having high affinity for a pigment carrier such as a binder resin and a solvent which is a dispersion medium, and is represented by the following general formula (15).

In the general formula (15)

R ⁵⁰¹ is a residue other than a hydroxyl group and a thiol group in the compound (a11)

R ⁵⁰² is a residue other than a double bond and R ⁵⁰³ in the ethylenically unsaturated monomer (a12)

R ⁵⁰³ is a hydrogen atom or a methyl group,

n ⁵⁰¹ is an integer of 2 or more, preferably an integer of 3 to 200.

Here, R ⁵⁰¹ is a terminal region referred to in the vinyl polymer (A1).

[Compound (a11) having two hydroxyl groups and one thiol group in the molecule]

The compound (a11) having two hydroxyl groups and one thiol group in the molecule (hereinafter sometimes referred to as the compound (a11)) may be a compound having two hydroxyl groups and one thiol group in the molecule, 1-mercapto-1,1-ethanediol, 3-mercapto-1,2-propanediol (thioglycerol), 2-mercapto- Propanediol, 2-mercapto-2-methyl-1,3-propanediol, 2-mercapto-2- , 2-mercaptoethyl-2-methyl-1,3-propanediol and 2-mercaptoethyl-2-ethyl-1,3-propanediol.

The compound (a11) and the ethylenically unsaturated monomer (a12) are optionally mixed with the polymerization initiator in accordance with the molecular weight of the vinyl polymer (A1) having two hydroxyl groups in the intended one terminal region and heated to obtain the vinyl polymer Can be obtained. It is preferable to perform bulk polymerization or solution polymerization using 0.5 to 30 parts by weight of the compound (a11) relative to 100 parts by weight of the ethylenically unsaturated monomer (a12). The amount of the compound (a11) to be added to 100 parts by weight of the ethylenically unsaturated monomer (a12) is more preferably 1 to 20 parts by weight, still more preferably 2 to 15 parts by weight, particularly preferably 2 to 10 parts by weight . The reaction temperature is 40 to 150 ° C, preferably 50 to 110 ° C. If the amount of the compound (a11) is less than 0.5 parts by weight, the molecular weight of the vinyl polymer moiety is too high, and the absolute amount of the vinyl polymer moiety is increased as an affinity for the pigment carrier and the solvent. On the other hand, if the amount is more than 30% by weight, the molecular weight of the vinyl polymer portion is too low, so that the effect of steric repulsion can not be attained as an affinity for the pigment carrier and the solvent, and it becomes difficult to suppress aggregation of the pigment.

[Polymerization Initiator]

In the polymerization, 0.001 to 5 parts by weight of a polymerization initiator can be optionally used per 100 parts by weight of the ethylenically unsaturated monomer (a12). As the polymerization initiator, an azo compound and an organic peroxide may be used. Examples of the azo based compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane 1-carbonitrile) (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis 2-methylpropionate), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile) and 2,2'-azobis [ 2- (2-imidazolin-2-yl) propane]. Examples of organic peroxides include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propylperoxydicarbonate, di (2- ethoxyethyl) peroxydicarbonate, t- Butyl peroxyneodecanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide and diacetyl peroxide. These polymerization initiators may be used alone or in combination of two or more.

[Polymerization solvent]

In the case of solution polymerization, the polymerization solvent is ethyl acetate, n-butyl acetate, isobutyl acetate, N-methyl-2-pyrrolidone, toluene, xylene, acetone, hexane, methyl ethyl ketone, cyclohexanone and diethylene glycol di Ethyl ether and the like can be used, but the present invention is not limited thereto. These polymerization solvents may be used in combination of two or more kinds, but it is preferable that they are used as a solvent for end use.

[Ethylenically unsaturated monomer (a12)]

As the ethylenically unsaturated monomer (a12), for example,

(Meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t- (Meth) acrylates such as butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, stearyl Alkyl (meth) acrylates such as isobornyl (meth) acrylate;

Aromatic (meth) acrylates such as phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate and phenoxy diethylene glycol (meth) acrylate;

Heterocyclic (meth) acrylates such as tetrahydrofurfuryl (meth) acrylate and oxetane (meth) acrylate;

Alkoxypolyalkylene glycol (meth) acrylates such as methoxypolypropylene glycol (meth) acrylate and ethoxypolyethylene glycol (meth) acrylate;

(Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl N-substituted (meth) acrylamides such as morpholine;

(Meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate and N, N-diethylaminoethyl (meth) acrylate;

(Meth) acrylonitrile, and the like.

Examples of the monomers that can be used in combination with the acrylic monomer include styrene and styrene such as styrene and? -Methylstyrene; Vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether and isobutyl vinyl ether; And fatty acid vinyls such as vinyl acetate and vinyl propionate.

The carboxyl group-containing ethylenic unsaturated monomer may also be used in combination. The carboxyl group-containing ethylenically unsaturated monomer may be selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and crotonic acid.

[Polymerization conditions and others]

Among the ethylenically unsaturated monomers (a12) exemplified above, methyl methacrylate is preferably used in the present invention from the viewpoints of dispersibility and resistance. From the viewpoint of affinity with the pigment carrier and the dispersion medium, it is more preferable to use methyl methacrylate in combination with butyl methacrylate or t-butyl methacrylate. When methyl methacrylate is used as the ethylenically unsaturated monomer (a2) and butyl methacrylate is not used, the proportion of methyl methacrylate in the total of 100% by weight of the ethylenically unsaturated monomer (a12) is 30 to 100 wt% %, More preferably 50 to 100% by weight. When methyl methacrylate and butyl methacrylate or t-butyl methacrylate are used in combination as the ethylenically unsaturated monomer (a12), the sum of the two accounts for 30 to 100% by weight of the ethylenically unsaturated monomer (a12) , More preferably from 50 to 100% by weight. When methyl methacrylate is used as the ethylenically unsaturated monomer (a12), and when methyl methacrylate and butyl methacrylate or t-butyl methacrylate are used in combination, the pigment dispersibility becomes better. The copolymerization site of methyl methacrylate and butyl methacrylate or t-butyl methacrylate maintains basic physical properties such as dispersibility and the like, and has good compatibility with binder resin or dispersion solvent, and is highly versatile.

The weight average molecular weight (Mw) of the vinyl polymer (A1) having two hydroxyl groups in one terminal region in terms of polystyrene calculated by GPC is preferably 500 to 30,000, more preferably 1,000 to 15,000, Particularly preferably 8,000. When the weight average molecular weight is less than 500, the effect of steric repulsion due to the solvent-friendly moiety is reduced, and it is difficult to prevent aggregation of the pigment, and dispersion stability may become insufficient in some cases. On the other hand, if it is more than 30,000, the absolute amount of the solvent-affinitive portion increases, and the effect of dispersibility itself may decrease. And the viscosity of the dispersion may be increased.

When the weight average molecular weight is in the range of 500 to 30,000, it is advantageous to prevent agglomeration of the pigment and suppress the viscosity increase of the pigment dispersion.

The glass transition temperature (Tg) of the vinyl polymer (A1) having two hydroxyl groups in one end terminal region is preferably 50 to 200 占 폚, more preferably 50 to 120 占 폚 in that the resistance of the coating film is improved.

The Tg of the vinyl polymer (A1) having two hydroxyl groups in one terminal region was calculated by the following Fox equation. A skeleton derived from the compound (a11) having two hydroxyl groups and one thiol group in the molecule is also present in the vinyl polymer (A1), but is excluded from the following calculations for calculating the glass transition temperature.

1 / Tg = W1 / Tg1 + W2 / Tg2 + + Wn / Tgn

In the above formula, Wn represents the weight fraction of each monomer used, and Tgn represents the glass transition temperature (unit: absolute temperature " K ") of each homopolymer obtained from each monomer.

The Tg of the major homopolymer used in the calculation is illustrated below.

Methyl methacrylate: 105 占 폚 (378K)

Butyl methacrylate: 20 ° C (293K)

t-Butyl methacrylate: 107 DEG C (380K)

Lauryl methacrylate: -65 占 폚 (208K)

2-ethylhexyl methacrylate: -10 ° C (263K)

Cyclohexyl methacrylate: 66 占 폚 (339K)

Butyl acrylate: -45 ° C (228K)

Ethyl acrylate: -20 ° C (253K)

Benzyl methacrylate: 54 DEG C (327K)

Styrene: 100 ° C (373K)

[Diisocyanate (B1)]

As the diisocyanate (B1) which is a component of the polymer (G1) having a basic functional group, conventionally known ones can be used. For example, aromatic diisocyanate (b11), aliphatic diisocyanate (b12), aromatic aliphatic diisocyanate (b13) and an alicyclic diisocyanate (b14).

Examples of the aromatic-containing diisocyanate (b11) include xylene diisocyanate, 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, , 4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, naphthylene diisocyanate, and 1,3-bis (isocyanatomethyl) benzene.

Examples of the aliphatic-containing diisocyanate (b12) include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3 -Butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

Examples of the aliphatic-containing diisocyanate (b13) include ω, ω'-diisocyanate-1,3-dimethylbenzene, ω'-diisocyanate-1,4-dimethylbenzene, ω, ω'-diisocyanate-1,4 -Diethylbenzene, 1,4-tetramethylxylene diisocyanate, and 1,3-tetramethylxylene diisocyanate.

Examples of the alicyclic diisocyanate (b14) include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3- Cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, and methyl-2,6-cyclohexane diisocyanate.

The diisocyanate (B1) listed above is not necessarily limited to these, and two or more diisocyanates may be used in combination.

The diisocyanate (B) used in the present invention is preferably 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI) because it is egg yolk-denatured.

[Polyamine (D1)]

The polyamine (D1) which is a component of the polymer (G1) having a basic functional group is a compound having at least two primary and / or secondary amino groups and is used to react with an isocyanate group to form a urea bond. Such amines include diamines (d11).

Specific examples of the diamine (d11) having two primary amino groups include ethylenediamine, propylenediamine (also referred to as 1,2-diaminopropane or 1,2-propanediamine), trimethylenediamine Diaminobutane], 2-methyl-1,3-propanediamine, and pentamethylenediamine (also referred to as "1,3-diaminopropane or 1,3-propanediamine" : 1,5-diaminopentane], hexamethylenediamine [alias: 1,6-diaminohexane], 2,2-dimethyl-1,3-propanediamine, 2,2,4-trimethylhexamethylenediamine and tall Aliphatic diamines such as rylene diamine;

Alicyclic diamines such as isophoronediamine and dicyclohexylmethane-4,4'-diamine; And aromatic diamines such as phenylenediamine and xylenediamine.

As the diamine (d11) having two secondary amino groups, known diamines can be used. Specific examples thereof include N, N-dimethylethylenediamine, N, N-diethylethylenediamine and N, -Butylethylenediamine, and the like.

The diamine (d11) having primary and secondary amino groups may be any of those known in the art. Specific examples thereof include N-methylethylenediamine [alias: methylaminoethylamine] and N- ethylethylenediamine [ Ethylamine], N-methyl-1,3-propanediamine [alias: N-methyl-1,3-diaminopropane or methylaminopropylamine], N, Isopropyl-1,3-diaminopropane (also called N-isopropyl-1,3-propanediamine or isopropylaminopropylamine) and N-isopropylethylenediamine (also called isopropylaminoethylamine) Lauryl-1,3-propanediamine [also known as N-lauryl-1,3-diaminopropane or laurylaminopropylamine].

The polyamine of the present invention is a compound having at least two primary and / or secondary amino groups, and a primary and / or secondary amine reacts with an isocyanate group to form a urea group. If the urea group is a pigment adsorption site, but the polyamine (D1) has two primary and / or secondary amino groups at both ends and also has secondary and / or tertiary amino groups other than both ends, the acidic pigment It is particularly preferable because the adsorbability of the adsorbent increases.

Examples of the polyamine (D1) include a polyamine (d12) having two primary and / or secondary amino groups at both ends and having secondary and / or tertiary amino groups in addition to the terminal ends.

As the polyamine (d12)

(N, N-bis (3-aminopropyl) laurylamine], iminobispropylamine (also referred to as N, N, N'-bisaminopropyl-1,3-propylenediamine and N, N'-bisaminopropyl-1,4-butylenediamine, etc., . Methyliminobispropylamine and lauryl iminobispropylamine having two primary amino groups and one tertiary amino group are preferable because they can easily control the reaction with the diisocyanate.

It is preferable that the iminobispropylamine having two primary amino groups and one secondary amino group has good adsorption to the pigment.

As the polyamine (D1) of the present invention, a polymer (d13) having two or more primary and / or secondary amino groups may also be used.

Examples of the polymer (d13) having a primary and / or secondary amino group include a homopolymer of an ethylenically unsaturated monomer having a primary amino group or an ethylenically unsaturated monomer having a secondary amino group such as vinylamine or allylamine, Polyvinylamine or polyallylamine) or copolymers thereof with other ethylenically unsaturated monomers, a ring-opening polymer of ethyleneimine, a condensation polymer of ethylene chloride and ethylenediamine, or a ring-opening polymer of oxazolidin-2 (that is, a polyethyleneimine ). ≪ / RTI > The content of primary and / or secondary amino groups in the polymer is preferably from 10 to 100% by weight, and more preferably from 20 to 100% by weight, based on the polymer as a monomer unit. When the content is 10% by weight or more, it is effective to prevent agglomeration of the pigment and suppress an increase in viscosity.

Examples of the ethylenic unsaturated monomer copolymerizable with the ethylenic unsaturated monomer having a primary amino group or the ethylenic unsaturated monomer having a secondary amino group include (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid and fumaric acid Unsaturated carboxylic acids;

Aromatic vinyl compounds such as styrene,? -Methylstyrene, p-hydroxystyrene, chloromethylstyrene, indine and vinyltoluene;

Alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate and 2-ethylhexyl

Alkyl (meth) acrylate esters such as benzyl (meth) acrylate;

(Meth) acrylic acid substituted alkyl esters having a functional group such as glycidyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate;

(Meth) acrylic acid substituted alkyl esters having a tertiary amino group such as dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate;

(Meth) acrylamide, dimethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, n-butyl Alkyl (meth) acrylamide;

Substituted alkyl (meth) acrylamides such as dimethylaminoethyl (meth) acrylamide and dimethylaminopropyl (meth) acrylamide;

Diene compounds such as 1,3-butadiene and isoprene;

Polymerizable oligomers (macromonomers) such as one-terminal methacryloylated polymethyl methacrylate oligomer, one-terminal methacryloylated polystyrene oligomer and one-terminal methacryloylated polyethylene glycol; And

Vinyl cyanide, and the like.

The weight average molecular weight (Mw) of the polymer having primary and / or secondary amino groups in terms of polystyrene determined by GPC (gel permeation chromatography) is preferably 300 to 75,000, more preferably 300 to 20,000, Particularly preferably 500 to 5,000. When the weight average molecular weight is 300 to 75,000, agglomeration of the pigment is prevented and it is effective to suppress the viscosity increase of the pigment dispersion.

[Monoamine (E1)]

As the amine compound constituting the polymer (G1) having a basic functional group, a monoamine (E1) can be used in addition to the polyamine (D1). The monoamine (E1) is a monoamine compound having one primary amino group or secondary amino group in the molecule and the monoamine (E1) is excessively high in the reaction of the diisocyanate (B1) and the polyamine (D1) And is used as a quencher to inhibit the formation of an acid. The monoamine (E1) may have a polar functional group other than the primary amino group or the secondary amino group in the molecule. Examples of such a polar functional group include a hydroxyl group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, a cyano group, and a nitroxyl group.

As the monoamine (E1), conventionally known compounds can be used, and specifically,

Aminobenzene, 1-aminopentane, 2-aminopentane, 3-aminopentane, isoamylamine, N-ethylisobutane, Aminodecane, 1-aminododecane, 1-aminotridecane, 1-aminohexane, 1-aminodecane, 1-aminodecane, Aminocyclohexane, 1-amino-2-ethylhexane, 1-amino-2-methylpropane, 2-amino-2 3-aminomethylheptane, 3-isopropoxypropylamine, 3-butoxypropylamine, 3-isobutoxypropylamine, 2-ethylhexyloxypropylamine, 3 Decyloxypropylamine, 3-lauryloxypropylamine, 3-myristyloxypropylamine, 2-aminomethyltetrahydrofuran, dimethylamine, Ethylamine, N-methylethylamine, N-methylisopropylamine, N-methylhexylamine, diisopropylamine, di-n-propylamine, , 2-dimethylpropylamine, piperidine, 2-piperolin, 3-piperolin, 4-piperolin, 2,4-lupetidine, 2,6- But are not limited to, 3-piperidine methanol, 3-piperidinemethanol, piperolinic acid, isonipecotic acid, methylisonipecotate, ethylisonipecotate, 2-piperidineethanol, 4- Aniline, o-aminotoluene, m-aminotoluene, p-aminobutyrate, p-aminopyrrolidine, Benzyl aniline, 1-aminoanthraquinone, 2-aminoanthraquinone, 1-aminoanthracene, 2-aminoanthracene, 5-aminoisoquinoline, o-amino di Phenyl, 4-aminodiphenyl Amino benzophenone, o-amino acetophenone, m-amino acetophenone, p-amino acetophenone, benzylamine, N-methylbenzylamine, 3-benzyl Aminopropionic acid ethyl ether, 4-benzylpiperidine,? -Phenylethylamine, phenethylamine, p-methoxyphenethylamine, furfurylamine, p-aminoazobenzene, m-aminophenol, Amine and diphenylamine.

Of the exemplified aliphatic amines having no rigidity, monoamine compounds having only a secondary amino group are preferable because of good dispersibility.

Examples of the aliphatic monoamine compound having only the secondary amino group include dimethylamine, diethylamine, N-methylethylamine, N-methylisopropylamine, N-methylhexylamine, diisopropylamine, butylamine, di-sec-butylamine, N-ethyl-1,2-dimethylpropylamine, piperidine, 2-pipercoline, 3-piperolin, 4-piperolin, 2,4- Piperidine, 3-piperidine methanol, 2-piperidineethanol, 4-piperidineethanol, 4-piperidinol, pyrrolidine, 3-amino Pyrrolidine, 3-pyrrolidinol, and the like.

Since the tertiary amino group does not have an active hydrogen which reacts with the isocyanate group, the diamine having a primary or secondary amino group and a tertiary amino group can be used as a monoamine (E1). In the present invention, the pigment adsorbing ability A tertiary amino group having an improving effect can be introduced.

As the diamine having a primary or secondary amino group and a tertiary amino group,

N, N-dimethylethylenediamine, N, N-diethylethylenediamine, N, N-dimethyl-1,3-propanediamine and N, N, A diamine having a primary amino group and a tertiary amino group; and

And diamines having a secondary amino group and a tertiary amino group such as N, N, N'-trimethylethylenediamine.

These monoamine (E1) compounds may be used alone or in combination of two or more. Since the active hydrogen of the urea bond after the reaction of the primary amino group with the isocyanate group is low in reactivity, the molecular weight of the active hydrogen is not increased by reacting with the isocyanate group further under the polymerization conditions of the dispersant of the present invention.

[Urethane prepolymer (C1)]

The urethane prepolymer (C1), which is a component of the polymer (G1) having a basic functional group, is obtained by reacting a hydroxyl group of the vinyl polymer (A1) having two hydroxyl groups in one terminal region with an isocyanate group of the diisocyanate .

For example, when the number of moles of the vinyl polymer (A1) is α and the number of moles of the diisocyanate (B1) is β, urethane / A prepolymer can be obtained. If? is a positive integer, the larger the?, the higher the molecular weight. The actual structure control will be described later in detail.

[Synthetic catalyst (F1)]

A known catalyst (F1) can be used in the synthesis of the urethane prepolymer (C1). For example, a tertiary amine compound and an organometallic compound.

Examples of the tertiary amine compound include triethylamine, triethylenediamine, N, N-dimethylbenzylamine, N-methylmorpholine and diazabicyclo-undecene (DBU).

Examples of the organometallic compounds include tin compounds and non-saponified compounds.

The tin compound includes, for example, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyl Tributyl tin acetate, tributyl tin acetate, triethyl tin ethoxide, tributyl tin ethoxide, dioctyl tin oxide, tributyltin chloride, tributyltin trichloroacetate And 2-ethylhexanoic acid tin.

As the non-saprophytic compound, for example,

Titanium based materials such as dibutyltitanium dichloride, tetrabutyl titanate and butoxy titanium trichloride;

Lead lead such as lead oleate, lead 2-ethylhexanoate, lead benzoate and lead naphthene;

Iron-based iron such as 2-ethylhexanoate and iron acetylacetonate;

Cobalt-based compounds such as cobalt benzoate and cobalt 2-ethylhexanoate;

A zinc system such as zinc naphthenate and zinc 2-ethylhexanoate; And

And zirconium compounds such as zirconium naphthenate.

Of these catalysts, dibutyltin dilaurate (DBTDL) and 2-ethylhexanoate are preferred from the viewpoints of reactivity and hygiene.

The catalysts such as the tertiary amine compound and the organometallic compound may be used singly or in combination.

The organometallic compound catalyst used in the synthesis of the urethane prepolymer (C1) remarkably promotes the reaction even in a reaction different from the amine described later.

<Synthesis solvent>

In the synthesis of the urethane prepolymer (C1), a known solvent is suitably used. The use of a solvent serves to facilitate reaction control.

Examples of the solvent used for this purpose include ethyl acetate, n-butyl acetate, isobutyl acetate, N-methyl-2-pyrrolidone, toluene, xylene, acetone, hexane, methyl ethyl ketone, cyclohexanone, propylene Glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether, and the like, but are not limited thereto.

In view of the solubility of the urethane prepolymer (C1), the boiling point of the solvent, and the solubility of the amine, ethyl acetate, toluene, methyl ethyl ketone, diethylene glycol diethyl ether or a mixed solvent thereof is particularly preferable.

When the solvent is used, the concentration in the urethane prepolymer reaction system is preferably 30 to 95% by weight from the viewpoint of reaction control in terms of the solid content concentration of the urethane prepolymer, more preferably 40 to 90% by weight, to be. If the amount is less than 30% by weight, the reaction is slowed down and unreacted materials may remain, which is not preferable. If it exceeds 95% by weight, the reaction may progress partially and suddenly, and it is not preferable because the molecular weight becomes difficult to control.

[Synthesis conditions]

Various methods can be applied to the urethanization reaction in which the urethane prepolymer (C1) is prepared by reacting the hydroxyl group of the vinyl polymer (A1) having two hydroxyl groups at one terminal region with the isocyanate group of the diisocyanate (B1) . Typical methods are as follows: 1) the reaction is carried out by adding the whole amount and 2) the vinyl polymer (A) having two hydroxyl groups at one terminal region and, if necessary, the solvent are added to the flask and the diisocyanate (B1) And a method in which the catalyst is added in accordance with the catalyst. When the reaction is precisely controlled, the method 2) is preferable. The reaction temperature for obtaining the urethane prepolymer (C1) is preferably 120 占 폚 or lower. More preferably 50 to 110 ° C. If it is higher than 110 ° C, it becomes difficult to control the reaction rate, and a urethane prepolymer having a predetermined molecular weight and structure can not be obtained. The urethanization reaction is preferably carried out in the presence of a catalyst at 50 to 110 DEG C for 1 to 20 hours.

When the molar ratio of the vinyl polymer (A1) having two hydroxyl groups in the one terminal region to the integer? Is in the blending ratio of the vinyl polymer (A1) and the diisocyanate (B1) having two hydroxyl groups in the one terminal region , The diisocyanate (B1) molar ratio is? + 1, and the urethane prepolymer (C1) having an isocyanate group at both terminals of the liquid crystal phase can be synthesized. the ratio (? + 1) /? of the diisocyanate (B1) to the vinyl polymer (A1) is 2 or less since the minimum of? When the diisocyanate is further increased, all of the isocyanate groups in the mixture of the urethane prepolymer (C1) and the excess diisocyanate (B) are designed to react with the primary and / or secondary amino groups of the polyamine (D1) and the monoamine (E1) , The excess diisocyanate (B1) can be incorporated into the dispersant molecule of the present invention. In the case of synthesizing a typical urethane prepolymer (C1), excess polyisocyanate is often mixed in anticipation of chain extension by a polyamine in the next step in order not to retain the polyol. However, in the dispersant of the present invention, there is a high possibility that an impurity derived from an excess of diisocyanate (B1) derived polymer or a hydrolyzate of excess diisocyanate (B1) adversely affects pigment dispersibility and stability with time .

Therefore, the compounding molar ratio of the diisocyanate (B1) to the vinyl polymer (A1) having two hydroxyl groups in the one terminal region is preferably 1.01 to 3.00 from the viewpoint of the productivity of the urethane prepolymer (C1) More preferably 1.30 to 2.30 from the viewpoint of the design of the pigment dispersion (balance between the pigment adsorption site and the solvent-affinity site), and most preferably from 1.50 to 2.00 from the viewpoint of the dispersion stability of the pigment dispersion using the final dispersant. If the compounding molar ratio is too small, the dispersant as the final product becomes a high molecular weight, and the viscosity of the pigment dispersion or the paint or ink using the same becomes high, which is a problem in practical use. As described above, if the compounding molar ratio is larger than 2.00, the diisocyanate (B1) having no vinyl-polymerized portion derived from the vinyl polymer (A1) and the urethane portion derived therefrom increase, and the adverse effect on the pigment dispersion performance is seriously affected.

[Production method and synthesis conditions of polymer (G1) having basic functional group]

The polymer (G1) having a basic functional group constituting the composition of the present invention

(A1) having two hydroxyl groups in the one terminal region composed of radicals of the ethylenically unsaturated monomer (a12) in the presence of the compound (a11) having two hydroxyl groups and one thiol group in the molecule, A first step of producing

A second step of producing an urethane prepolymer (C1) having an isocyanate group at both ends, which is obtained by reacting a hydroxyl group of the vinyl polymer (A1) having two hydroxyl groups in the one terminal region with an isocyanate group of the diisocyanate (B1) and,

And a third step of reacting an isocyanate group of a urethane prepolymer (C1) having an isocyanate group at its terminal end with a primary and / or secondary amino group of a polyamine (D1) and a monoamine (E2).

A urea reaction for obtaining a urethane urea resin in the urethane prepolymer (C1), a polyamine (D1) and a monoamine (E1) or a polyurethane urea having a primary or secondary amino group at the terminal thereof in the polymer (G1) having a basic functional group silver

1) a method of dropping a polyamine (D1) and a monoamine (E1) by adding a urethane prepolymer (C1) solution into a flask,

2) a method comprising dropping a urethane prepolymer (C1) solution into a flask by adding a solution composed of a polyamine (D1), a monoamine (E1) and, if necessary, a solvent.

A method capable of stably carrying out the reaction may be appropriately selected and synthesized. However, the above method 1), which is easier to operate if there is no problem in the reaction, is preferable. The temperature of the urea reaction of the present invention is preferably 100 DEG C or lower. More preferably not higher than 70 占 폚. When the reaction rate is high even at 70 ° C and can not be controlled, the temperature is preferably 50 ° C or less. If it is higher than 100 ° C, it is difficult to control the reaction rate, and it is difficult to obtain a urethane urea resin having a predetermined molecular weight and structure.

The compounding ratio of the urethane prepolymer (C1) and the polyamine (D1), and if necessary, the monoamine (E1) is not particularly limited and is arbitrarily selected depending on the application and the required performance.

The end point of the reaction is judged by measurement of isocyanate percentage by titration and disappearance of isocyanate peak by IR measurement.

The polymer (G1) having a basic functional group preferably has a weight average molecular weight (Mw) of 1,000 to 100,000, more preferably 1,500 to 50,000, and particularly preferably 1,500 to 20,000. If the weight average molecular weight is less than 1,000, the stability of the pigment dispersion may deteriorate. If the weight average molecular weight is more than 100,000, the interaction between the resins becomes strong, and the viscosity of the pigment dispersion may increase. The amine value of the obtained polymer is preferably 1 to 100 mgKOH / g, more preferably 2 to 50 mgKOH / g, and still more preferably 3 to 30 mgKOH / g. If the amine value is less than 1 mgKOH / g, the functional groups adsorbed to the pigment may be insufficient to contribute to pigment dispersion. When the amine value is more than 100 mgKOH / g, aggregation occurs between pigments, There is a case.

&Lt; Polymer (G2) having basic functional group >

The polymer (G2) having a basic functional group that can be used in the present invention is a polymer (A2) having one or two (meth) acryloyl groups in one terminal region and a (meth) acryloyl group of one or more primary (C2) having an amino group formed by reacting a primary and / or secondary amino group of a polyamine (B2) containing a primary amino group and / or a secondary amino group with a primary and / And isocyanate group of isocyanate (D2).

That is, a pigment adsorption site having a solvent affinity site derived from the polymer (A2) and an amino group and an urea bond site formed by reacting a primary and / or secondary amino group of the polyamine (C2) with an isocyanate group of the polyisocyanate (D2) The branch is made up of structures. The pigment adsorption site having an amino group and a urea bond site is excellent in an interaction ability with an organic dye derivative having an acidic functional group or a triazine derivative having an acidic functional group and the pigment adsorption property on the surface of the pigment, And dispersion stability can be achieved.

In the present specification, in the case of "(meth) acryloyl", "(meth) acrylic acid", "(meth) acrylate" and "(meth) acryloyloxy" Acrylic acid and / or methacrylic acid &quot;,&quot; acrylate and / or methacrylate &quot;, and &quot; acryloyloxy and / or methacryloyloxy &quot; It is also possible to do.

[Polymer (A2) having one or two (meth) acryloyl groups in one terminal region]

The weight average molecular weight of the polymer (A2) in the present invention is preferably 500 to 30,000, whereby the three-dimensional rebound effect is excellent, and high dispersibility, fluidity and storage stability can be obtained. The weight average molecular weight of the polymer (A2) is more preferably from 2,000 to 20,000, and most preferably from 5,000 to 10,000. If it is less than 500, the effect of steric repulsion by the solvent affinity block becomes less, which is not preferable. On the other hand, if it exceeds 30,000, the viscosity of the dispersion tends to be high, which is not preferable.

The polymer (A2) in the present invention is preferably a polyester (A21) or a vinyl polymer (A22). They have good affinity to a solvent and are easy to adjust the molecular weight. The (meth) acryloyl group in the one terminal region is preferably an acryloyl group in which the reaction proceeds at a relatively low temperature from the viewpoint of controlling the reaction with primary and / or secondary amino groups.

[Polyester (A21)]

The polyester (A21) can be produced by a known method, for example, by ring-opening polymerization of a lactone and / or lactide as an initiator with a monohydric alcohol having a (meth) acryloyl group.

[Monoalcohol having (meth) acryloyl group]

The monohydric alcohol having a (meth) acryloyl group used as the initiator of the ring-opening polymerization is not particularly limited, but 4-hydroxybutyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxy- Acrylate and 2-hydroxy-3- (meth) acryloyloxypropyl methacrylate. From the viewpoint of reactivity of the hydroxyl group, 4-hydroxybutyl acrylate and 2-hydroxyethyl acrylate It is preferable to use at least one kind selected from the group consisting of

[Lactones and lactides]

The lactone is not particularly limited and specific examples thereof include? -Butyrolactone,? -Butyrolactone,? -Valerolactone,? -Valerolactone,? -Caprolactone,? -Caprolactone and alkyl-substituted? -Capro Lactone, and the like, but it is preferable to use at least one member selected from the group consisting of δ-valerolactone, ε-caprolactone and alkyl-substituted ε-caprolactone from the viewpoint of ring-opening polymerization.

In the production method of the present invention, the lactone is not limited to the above-mentioned examples, but may be used alone, or two or more kinds of lactones may be used in combination.

The lactide is preferably represented by the following general formula (16) (including glycolide).

In the general formula (16)

R ¹ and R ² are each independently a hydrogen atom or a saturated or unsaturated, linear or branched alkyl group having 1 to 20 carbon atoms,

R ³ and R ⁴ are each independently a hydrogen atom, a halogen atom or a saturated or unsaturated, linear or branched lower alkyl group having 1 to 9 carbon atoms.

In the production process of the present invention, particularly preferred lactides are lactide (3,6-dimethyl-1,4-dioxane-2,5-dione) and glycolide (1,4- Dion).

The lactone and lactide may be used alone or in combination of two or more. Among the lactones and lactides, lactones are preferably used from the viewpoint of solvent affinity.

The number of moles of the lactone and / or lactide to be used per mole of the initiator is preferably 3 to 60 moles, more preferably 10 to 40 moles, and most preferably 15 to 30 moles. If it is less than 3 moles, the molecular weight becomes small, and it does not sufficiently function on the solvent-friendly property. If it exceeds 60 mols, the molecular weight becomes too large, and when used as a dispersant for a pigment, the viscosity of the pigment dispersion becomes high and problems are likely to occur.

[Ring opening polymerization catalyst]

As the ring-opening polymerization catalyst, any known catalyst may be used without limitation, and for example,

Quaternary ammonium salts such as tetramethylammonium chloride, tetrabutylammonium chloride, tetramethylammonium bromide, tetrabutylammonium bromide, tetramethylammonium iodide, tetrabutylammonium iodide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide and benzyltrimethylammonium iodide;

Tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetrabutylphosphonium iodide, benzyltrimethylphosphonium chloride, benzyltrimethylphosphonium bromide, benzyltrimethylsilyl chloride, benzyltrimethylphosphonium chloride, benzyltrimethylphosphonium chloride, Quaternary phosphonium salts such as phosphonium iodide, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide and tetraphenylphosphonium iodide;

Phosphorus compounds such as triphenylphosphine;

Organic carboxylic acid salts such as potassium acetate, sodium acetate, potassium benzoate and sodium benzoate;

Alkali metal alcoholates such as sodium alcoholate and potassium alcoholate;

Tertiary amines such as triethylamine and triphenylamine;

Organotin compounds such as dibutyltin dilaurate, dibutyltin oxide and dioctyltin oxide;

Organic aluminum compounds such as aluminum alkyl acetacetate diisopropylate, aluminum bisethylacetate and monoacetylacetonate, and aluminum trisacetylacetonate;

Organic titanate compounds such as tetra-n-butyl titanate, dimer, tetraisobutyl titanate, tetrastearyl titanate, and diisopropoxy bis (triethanolaminate) titanium;

And zinc compounds such as zinc chloride.

The amount of the ring-opening polymerization catalyst to be used is 0.1 ppm to 3000 ppm, preferably 1 ppm to 1000 ppm, based on 100 wt% of the lactone and / or lactide. When the amount of the catalyst is more than 3000 ppm, the coloring of the resin sometimes becomes worse. Conversely, when the amount of the catalyst used is less than 0.1 ppm, the ring-opening polymerization rate of the lactone and / or lactide becomes very slow, which is not preferable in some cases.

[Synthesis conditions]

The ring-opening polymerization temperature of the lactone and / or the lactide is 100 ° C to 220 ° C, preferably 110 ° C to 210 ° C. When the reaction temperature is less than 100 ° C, the reaction rate may be very slow. On the other hand, when the polymerization temperature exceeds 220 ° C, side reactions other than the addition reaction of lactone and / or lactide, for example, depolymerization of lactone adduct into lactone monomer, formation of cyclic lactone dimer and trimmer, have.

[Radical polymerization inhibitor]

In the case of polymerizing a compound having a (meth) acryloyl group, it is preferable to add a radical polymerization inhibitor and perform the reaction under a stream of dry air. As the radical polymerization inhibitor, known ones can be used without limitation, and examples thereof include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, p-benzoquinone, 2,4-dimethyl-6-t- Azine and the like are preferable. These may be used alone or in combination in an amount of 0.01 wt% to 6 wt%, preferably 0.05 wt% to 1.0 wt% based on 100 wt% of an alcohol having a (meth) acryloyl group.

The polyester (A21) is a polyester obtained by polymerizing a monoalcohol having no (meth) acryloyl group as an initiator and a polyester having a hydroxyl group at one end obtained by ring-opening polymerization of lactone and a group capable of reacting with a hydroxyl group, A compound having an acryloyl group may be reacted.

[Compound having a group capable of reacting with a hydroxyl group and a (meth) acryloyl group]

As the compound having a group capable of reacting with a hydroxyl group and a (meth) acryloyl group, a compound having an isocyanate group and a (meth) acryloyl group is preferable. For example, 2- (meth) acryloyloxyethyl isocyanate.

In the preparation of the polyester (A21), a monoalcohol having no (meth) acryloyl group at the beginning is subjected to ring-opening polymerization with lactone as an initiator to prepare a polyester having a hydroxyl group at one end, A compound having one anhydride group is reacted to prepare a polyester having a carboxyl group at one end. The above-mentioned polyester having a carboxyl group, a compound having an epoxy group and a (meth) acryloyl group, or a compound capable of reacting with a hydroxyl group obtained by ring opening of the epoxy group and a compound having the (meth) acryloyl group And the like. In this case, a polyester (A21) having two (meth) acryloyl groups in one end terminal region can be obtained.

[Monoalcohol having no (meth) acryloyl group]

The monoalcohol having no (meth) acryloyl group may be any compound as long as it is a compound having one hydroxyl group.

For example, alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, isobutanol, tert-butanol, 1-heptanol, 1-octanol, isooctanol, 2-ethylhexanol, 1-nonanol, isononanol, 1-decanol, 1-dodecanol, 1-myristyl alcohol, Aliphatic monoalcohols such as stearyl alcohol, isostearyl alcohol, 2-octyldecanol, 2-octyldodecanol, 2-hexyldecanol, behenyl alcohol and oleyl alcohol;

Containing monoalcohols such as benzyl alcohol, phenoxyethyl alcohol and para-cumylphenoxyethyl alcohol, and

Ethylene glycol monoethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl Propylene glycol monohexyl ether, propylene glycol mono-2-ethylhexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether , Diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol mono-2-ethylhexyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol Monobutyl ether, Dipropylene glycol monohexyl ether, dipropylene glycol mono-2-ethylhexyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, triethylene glycol mono Hexyl ether, triethylene glycol mono-2-ethylhexyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, tripropylene glycol monobutyl ether, tripropylene glycol monohexyl ether, tri Propylene glycol mono-2-ethylhexyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monopropyl ether, tetraethylene glycol monobutyl ether, tetraethylene glycol monohexyl ether, tetraethylene glycol mono- 2- T-butyl hexyl ether, tetrapropyleneglycol monomethyl ether, tetrapropyleneglycol monoethyl ether, tetrapropyleneglycol monopropyl ether, tetrapropyleneglycol monobutyl ether, tetrapropyleneglycol monohexyl ether, tetrapropyleneglycol mono-2-ethylhexyl ether, And alkylene glycol monoalkyl ethers such as tetraethylene glycol monomethyl ether.

[Compound having one dibasic acid anhydride group]

The compound having one dibasic acid anhydride group may be any compound as long as it is a compound having one dibasic acid anhydride group.

For example, succinic anhydride, glutaric anhydride, cyclohexane-1,2-dicarboxylic anhydride, cyclohexene-1,2-dicarboxylic anhydride, dicyclo [2,2,2] 2,3-dicarboxylic anhydride, phthalic anhydride, naphthalene-1,2-dicarboxylic anhydride, naphthalene-2,3-dicarboxylic anhydride, anthracene-1,2-dicarboxylic anhydride, -Dicarboxylic anhydride and the like. Examples of the dibasic acid anhydride having a substituent such as a straight chain alkyl group, a branched alkyl group, a cyclic alkyl group, a heterocyclic ring, an aromatic ring and a halogen may be mentioned.

[Compound having an epoxy group and (meth) acryloyl group]

Examples of the compound having an epoxy group and (meth) acryloyl group include glycidyl acrylate, methyl glycidyl acrylate, 3,2-glycidoxyethyl acrylate, 3,4-epoxycyclohexyl acrylate, 3,4 -Epoxybutyl acrylate and 4,5-epoxypentyl acrylate.

The polyester (A21) is a polyester obtained by polymerizing a monocarboxylic acid having no (meth) acryloyl group as an initiator and a polyester having a carboxyl group at one end obtained by ring-opening polycondensation of a lactone and further adding the above epoxy group and (meth) acryloyl group Can also be obtained by reacting a compound with a compound capable of reacting with a hydroxyl group obtained by ring opening of an epoxy group and a compound having a (meth) acryloyl group. In this case, a polyester (A21) having two (meth) acryloyl groups in one end terminal region can be obtained.

[Monocarboxylic acid having no (meth) acryloyl group]

The monocarboxylic acid having no (meth) acryloyl group may be any compound having a carboxyl group not having a (meth) acryloyl group.

(Isobutyric acid), isobutyric acid (valeric acid), isovaleric acid (isovaleric acid), pivalic acid, lauric acid, myristic acid, palmitic acid, Stearic acid, and isostearic acid.

[Vinyl polymer (A22)]

The vinyl polymer (A22) having one or two (meth) acryloyl groups in one end terminal region can react with a vinyl polymer (a23) having one or two hydroxyl groups in one terminal region (A24) having a t-butoxy group and a t-butoxy (meth) acryloyl group.

A vinyl polymer (a23) having one or two hydroxyl groups in one terminal region (hereinafter sometimes referred to as a vinyl polymer (a23)) may have one or two hydroxyl groups and one thiol Can be obtained by radical polymerization of the ethylenically unsaturated monomer (a21) in the presence of the compound (s) having a group represented by the formula (a). Since the thiol group of the compound (s) having one or two hydroxyl groups and one thiol group in the molecule serves as a chain transfer agent and the vinyl polymer (a23) is synthesized through the S atom, its molecular weight is lower than that of the ethylenically unsaturated monomer it is easy to adjust the molecular weight of the vinyl polymer (a23) to the above range in accordance with the amount of the compound (s) used for the a21), and as a result, the compatibility with the solvent can also be adjusted.

[Compound (s) having one or two hydroxyl groups and one thiol group in the molecule]

Examples of the compound (s) having one or two hydroxyl groups and one thiol group in the molecule include a compound having a hydroxyl group and a thiol group in a molecule such as 1-mercaptoethanol and 2-mercaptoethanol Compound (s1); and

1-mercapto-1,1-methanediol, 1-mercapto-1,1-ethanediol, 3-mercapto-1,2-propanediol (thioglycerol), 2-mercapto- Diol, 2-mercapto-2-methyl-1,3-propanediol, 2-mercapto-2-ethyl-1,3-propanediol, 1-mercapto- (S2) having two hydroxyl groups and one thiol group in the molecule such as ethyl-2-methyl-1,3-propanediol and 2-mercaptoethyl-2-ethyl- .

In the present invention, the compound (s2) having two hydroxyl groups and one thiol group in the molecule is preferable, and 3-mercapto-1,2-propanediol (thioglycerol) is more preferable.

By using the compound (s2) having two hydroxyl groups and one thiol group in the molecule, the finally obtained dispersant has an ideal structure having a pigment adsorption site having a plurality of amino groups and a plurality of solvent affinity sites.

[Ethylenically unsaturated monomer (a21)]

As the ethylenically unsaturated monomer (a21), for example,

Acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (Meth) acrylate, isoamyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (Meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, isomyristyl (Meth) acrylates;

(Meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyl Cyclic alkyl (meth) acrylates such as dicyclopentenyloxyethyl (meth) acrylate and isobornyl (meth) acrylate;

(Meth) acrylates such as trifluoroethyl (meth) acrylate, octafluoropentyl (meth) acrylate, perfluorooctylethyl (meth) acrylate and tetrafluoropropyl (meth) Ryu;

(Meth) acryloxy-modified polydimethylsiloxane (silicone macromers);

(Meth) acrylates having a heterocyclic ring such as tetrahydrofurfuryl (meth) acrylate and 3-methyl-3-oxetanyl (meth) acrylate;

Benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, para-cumylphenoxyethyl (meth) acrylate, para-cumylphenoxypolyethylene glycol (Meth) acrylates having an aromatic ring such as phenoxypolyethylene glycol (meth) acrylate;

(Meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (Meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, triethylene glycol monomethyl ether (meth) acrylate, triethylene glycol monoethyl ether (Meth) acrylates such as hexyl ether (meth) acrylate, dipropylene glycol monomethyl ether (meth) acrylate, tripropylene glycol mono (meth) acrylate, polyethylene glycol monolauryl ether (Poly) alkylene glycol monoalkyl ether (meth) acrylates such as acrylate;

Unsaturated carboxylic acids such as acrylic acid, acrylic acid dimer, methacrylic acid, itaconic acid, maleic acid, fumaric acid and crotonic acid;

Caprolactone adducts of the above carboxylic acids (additional molar numbers 1 to 5);

Acrylates such as 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxypropyl phthalate, 2- (meth) acryloyloxyethylhexahydrophthalate, 2- (meth) acryloyloxypropylhexahydro (Meth) acrylates having a carboxyl group such as phthalate, ethylene oxide modified succinic acid (meth) acrylate,? -Carboxyethyl (meth) acrylate and? -Carboxypolycaprolactone (meth) acrylate;

Styrenes such as styrene and? -Methyl styrene;

Vinyls such as vinyl acetate, vinyl propionate, vinyl (meth) acrylate and allyl (meth) acrylate;

Vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether and isobutyl vinyl ether,

Amides having no amino group such as (meth) acrylamide and N-vinylformamide; And acrylonitrile having no amino group. These may be used alone or in combination of two or more.

In the present invention, among the ethylenically unsaturated monomers (a21) exemplified above, the ethylenically unsaturated monomer (a22) represented by the following general formula (17) is preferably used. The amount of the ethylenically unsaturated monomer (a22) represented by the following general formula (17) is preferably 20% by weight to 100% by weight, and more preferably 20% by weight to 70% by weight based on the total amount of the ethylenically unsaturated monomer (a21). When the monomer represented by the general formula (17) is used, the solvent affinity is improved and the pigment dispersibility is improved. If it is less than 20% by weight, the effect of improving the solvent affinity is insufficient.

In the general formula (17), R ⁵ is a linear or branched alkyl group having 1 to 4 carbon atoms.

[Amount of compound (s) used]

The vinyl polymer (a23) can be obtained by mixing and heating the ethylenically unsaturated monomer (a21) and an optional polymerization initiator in accordance with the molecular weight of the vinyl polymer (a23) for which the compound (s) is intended as a chain transfer agent. The compound (s) is preferably subjected to bulk polymerization or solution polymerization in an amount of 0.8 to 30 parts by weight based on 100 parts by weight of the ethylenically unsaturated monomer (a21), more preferably 1.5 to 15 parts by weight, 2 to 9 parts by weight, particularly preferably 5 to 9 parts by weight. When the amount is less than 1 part by weight, the molecular weight becomes large and the viscosity of the dispersion becomes high, which is not preferable in some cases. If it exceeds 30 parts by weight, the molecular weight becomes small and the effect of steric repulsion by the solvent affinity block becomes small, which is not preferable in some cases.

The reaction temperature is 40 to 150 ° C, preferably 50 to 110 ° C. If the temperature is lower than 40 DEG C, the polymerization does not proceed sufficiently. If the temperature is higher than 150 DEG C, the molecular weight is increased and it becomes difficult to control the molecular weight.

[Radical polymerization initiator]

In the radical polymerization, 0.001 to 5 parts by weight of a polymerization initiator may be optionally used relative to 100 parts by weight of the ethylenically unsaturated monomer (a21).

As the polymerization initiator, for example,

Azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane 1-carbonitrile) Bis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxy valeronitrile), dimethyl 2,2'-azobis Azo compounds such as 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile) and 2,2'-azobis [2- Azolin-2-yl) propane]; and organic peroxides such as

Butyl perbenzoate, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxy dicarbonate, di-n-propyl peroxydicarbonate, di (2-ethoxyethyl) peroxydicarbonate, t- Organic peroxides such as decanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide and diacetyl peroxide. These polymerization initiators include They can be used singly or in combination of two or more.

[Compound (a24) having a group capable of reacting with a hydroxyl group and a (meth) acryloyl group]

The compound (a24) having a group capable of reacting with a hydroxyl group and a (meth) acryloyl group is preferably a compound having an isocyanate group and a (meth) acryloyl group, and examples thereof include 2- (meth) acryloyloxy Ethyl isocyanate and the like.

[Polymerization solvent]

The polyester (A21) and the vinyl polymer (A22) can be synthesized by using a solvent or a solvent as required.

In the case of solution polymerization, the polymerization solvent is ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, acetone, hexane, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate , Ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and N-methylpyrrolidone, but are not limited thereto. These polymerization solvents may be used by mixing two or more kinds. The solvent used in the polymerization reaction may be removed by an operation such as distillation after completion of the reaction, or may be used as a solvent for the next step as it is or as a part of the product.

[Polyamine (B2)]

The polyamine (B2) of the present invention is a compound having at least one primary and / or secondary amino group, and the primary and / or secondary amine has a (meth) acryloyl group at one end terminal (Meth) acryloyl group to produce a polymer (C2) having an amino group. Further, a part or all of the primary and / or secondary amine of the polymer (C2) having an amino group is reacted with an isocyanate group of the polyisocyanate (D2) to form a urea group. That is, in the dispersant of the present invention, the amino group and the urea bond existing in the one terminal region become the pigment adsorption site. Such a polyamine (B2) includes diamine (b21). In the case where the polyamine (B2) has two primary and / or secondary amino groups at both ends and also has secondary and / or tertiary amino groups in addition to both ends, the adsorbability to the acid pigment is improved Particularly.

As the diamine (b21) having two primary amino groups, a known diamine can be used, and specifically,

1,3-diaminopropane or 1,3-propanediamine], tetramethylenediamine (also referred to as 1,2-diaminopropane or 1,2-propanediamine), ethylene diamine 1,4-diaminobutane], 2-methyl-1,3-propanediamine, pentamethylenediamine [alias: 1,5-diaminopentane], hexamethylenediamine [alias: 1,6-diaminohexane ], Aliphatic diamines such as 2,2-dimethyl-1,3-propanediamine, 2,2,4-trimethylhexamethylenediamine and tolylene diamine;

Alicyclic diamines such as isophoronediamine and dicyclohexylmethane-4,4'-diamine, and

And aromatic diamines such as phenylenediamine and xylylenediamine.

As the diamine (b21) having two secondary amino groups, known diamines can be used, and specific examples thereof include N, N-dimethylethylenediamine, N, N-diethylethylenediamine and N, -Butylethylenediamine, and the like.

Further, as the diamine (b21) having a primary and secondary amino group, a known diamine can be used. Specifically, it is possible to use N-methylethylenediamine (also referred to as methylaminoethylamine), N-ethylethylenediamine (also referred to as ethylaminoethylamine) or N-methyl- 3-diaminopropane or methylaminopropylamine], N, 2-methyl-1,3-propanediamine, N-isopropylethylenediamine (also referred to as isopropylaminoethylamine) Diaminopropane (also referred to as N-isopropyl-1,3-propanediamine or isopropylaminopropylamine) and N-lauryl-1,3-propanediamine (also referred to as N-lauryl-1,3-diamino Propane or laurylaminopropylamine] and the like.

As the diamine (b21) having a primary and tertiary amino group, known diamines can be used. Specific examples thereof include N, N-dimethylethylenediamine [alias: dimethylaminoethylamine], N, N-diethylethylenediamine [alias: diethylaminoethylamine], N, N, N-dimethyl-1,3-diaminopropane or dimethylaminopropylamine].

As the polyamine (b22) having two primary and / or secondary amino groups at both terminal ends and having a secondary and / or tertiary amino group in addition to the terminal end, known ones can be used. Specifically, there may be mentioned methyliminobispropylamine (also referred to as N, N-bis (3-aminopropyl) methylamine), lauryliminobispropylamine N, N'-bisaminopropyl-1,3-propylenediamine and N, N'-bisaminopropyl-1,4-butylene (also referred to as N, Diamine, and the like.

Methyliminobispropylamine and lauryl iminobispropylamine having two primary amino groups and one tertiary amino group are preferable because they can easily control the reaction with diisocyanate.

The iminobispropylamine having two primary amino groups and one secondary amino group is preferable because of its good adsorptivity to pigments.

As the polyamine (B2) of the present invention, a polymer (b23) having two or more primary and / or secondary amino groups may also be used.

Examples of the polymer (b23) having a primary and / or secondary amino group include homopolymers of an ethylenic unsaturated monomer having a primary amino group or an ethylenically unsaturated monomer having a secondary amino group such as vinylamine or allylamine Vinylamine or polyallylamine), copolymers of these and other ethylenically unsaturated monomers, ring-opening polymers of ethyleneimine, polycondensates of ethylene chloride and ethylenediamine, or ring-opening polymers of oxazolidin-2 (that is, polyethyleneimine ). &Lt; / RTI &gt; The content of primary and / or secondary amino groups in the polymer is preferably from 10 to 100% by weight, and more preferably from 20 to 100% by weight, based on the polymer as a monomer unit. When the content is 10% by weight or more, it is effective to prevent agglomeration of the pigment and suppress an increase in viscosity.

Examples of the ethylenic unsaturated monomer copolymerizable with the ethylenic unsaturated monomer having the primary amino group or the ethylenic unsaturated monomer having the secondary amino group include, for example,

Unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid and fumaric acid;

Aromatic vinyl compounds such as styrene,? -Methylstyrene, p-hydroxystyrene, chloromethylstyrene, indine and vinyltoluene;

Alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate and 2-ethylhexyl

Alkyl (meth) acrylate esters such as benzyl (meth) acrylate;

(Meth) acrylic acid substituted alkyl esters having a functional group such as glycidyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate;

(Meth) acrylic acid substituted alkyl esters having a tertiary amino group such as dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate;

(Meth) acrylamide, dimethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, n-butyl Alkyl (meth) acrylamide;

Substituted alkyl (meth) acrylamides such as dimethylaminoethyl (meth) acrylamide and dimethylaminopropyl (meth) acrylamide;

Diene compounds such as 1,3-butadiene and isoprene;

Polymerizable oligomers (macromonomers) such as one-terminal methacryloylated polymethyl methacrylate oligomer, one-terminal methacryloylated polystyrene oligomer and one-terminal methacryloylated polyethylene glycol; And

Vinyl cyanide, and the like.

The weight average molecular weight (Mw) of the polymer having primary and / or secondary amino groups in terms of polystyrene determined by GPC (gel permeation chromatography) is preferably 300 to 75,000, more preferably 300 to 20,000, Particularly preferably 500 to 5,000. When the weight average molecular weight is 300 to 75,000, agglomeration of the pigment is prevented and it is effective to suppress the viscosity increase of the pigment dispersion.

[Monoamine]

As the amine compound constituting the dispersant of the present invention, a monoamine may be used in addition to the polyamine (B2). The monoamine is a monoamine compound having one primary amino group or secondary amino group in the molecule. The monoamine inhibits the molecular weight of the polymer (A2) from becoming too high in the reaction between the polymer (A2) and the polyamine (B) It is used as zero. The monoamine may have a polar functional group other than the primary amino group or the secondary amino group in the molecule. Examples of such a polar functional group include a hydroxyl group, a carboxyl group, a sulfonic acid group, a phosphoric acid group, a cyano group, and a nitroxyl group.

As the monoamine, conventionally known compounds can be used. Specific examples thereof include aminomethane, aminoethane, 1-aminopropane, 2-aminopropane, 1-aminobutane, 2-aminobutane, Aminopentane, 2-heptylamine, 1-aminonane, 1-aminodecane, 1-aminodecane, 1-aminopentane, Aminododecane, 1-aminododecane, 1-aminohexadecane, stearylamine, aminocyclopropane, aminocyclobutane, aminocyclopentane, aminocyclohexane, Hexane, 1-amino-2-methylpropane, 2-amino-2-methylpropane, 3-amino-1-propene, 3-aminomethylheptane, 3-isopropoxypropylamine, 3-isobutoxypropylamine, 2-ethylhexyloxypropylamine, 3-decyloxypropylamine, 3-lauryloxypropylamine, 3- Aminomethyltetrahydrofuran, dimethylamine, diethylamine, N-methylethylamine, N-methylisopropylamine, N-methylhexylamine, diisopropylamine, di-n-propylamine , Diphenylamine, di-sec-butylamine, N-ethyl-1,2-dimethylpropylamine, piperidine, 2-pipecoline, 3- Isopentanoic acid, isonipecotic acid, methyl isonipecotate, ethyl isonipecotate, ethyl isonipecotate, ethyl isonipecotate, isonipecotate, Pyrrolidine, 3-pyrrolidinol, indolin, aniline, 2-piperidine, ethanol, 4-piperidineethanol, 4-piperidinebutyric acid hydrochloride, 4-piperidinol, pyrrolidine, Benzyl aniline, 1-anilino naphthalene, 1-amino anthraquinone, 2-amino anthraquinone, 1-amino anthraquinone, 1- Aminoanthracene, 2- Aminobenzophenone, o-aminoacetophenone, m-aminoacetophenone, o-aminobenzophenone, o-aminoacetophenone, m-aminoacetophenone, Phenanthroline, p-methoxyphenethylamine, p-methoxyphenethylamine, p-methoxyphenethylamine, p-methoxyphenethylamine, Aminophenol, p-aminophenol, allylamine, diphenylamine, and the like.

[Polymer (C2) having an amino group]

The polymer (C2) having an amino group may be a polymer having a primary or secondary amino group of the polyamine (B2) having one or two (meth) acryloyl groups in one end terminal region ( A2) to the (meth) acryloyl group. This reaction is commonly called the Michael addition reaction. A structure having a primary or secondary amino group capable of reacting with an isocyanate group can be obtained by adjusting the blend of the polymer (A2) and the polyamine (B2).

In the general formula (18), X ¹ is a portion other than the acryloyloxy group with an acrylic (meth) in the polymer (A2), Y ¹ is a portion other than the primary and secondary amino group of a polyamine (B2), R ⁶ is hydrogen An atom or a methyl group, and R ⁷ is a hydrogen atom or an alkyl group.

For example, with respect to one molecule of the polymer (A2) having one (meth) acryloyl group at one terminal end region as shown in the following general formula (19), the molecule 1 of the diamine (B2) having two primary amino groups , One molecule of the polymer (C2) having one primary amino group and one secondary amino group logically can be obtained.

In the general formula (19), X ¹ is a part of the polymer (A2) excluding the (meth) acryloyloxy group, Y ² is a part of the polyamine (B2) excluding the primary amino group, R ⁶ is a hydrogen atom or a methyl group to be.

Further, for example, a diamine having one primary amino group and one secondary amino group for one molecule of the polymer (A2) having two (meth) acryloyl groups in one terminal end region as shown by the following general formula (20) (B2) are reacted, one molecule of the polymer (C2) having four secondary amino groups can be obtained logically.

In the general formula (20), X ² is a portion other than the acryloyloxy group with an acrylic (meth) in the polymer (A2), Y ² is a portion other than the primary and secondary amino group of a polyamine (B2), R ⁶ is hydrogen An atom or a methyl group, and R ⁸ is an alkyl group.

Further, for example, a molecule of a diamine (B) having two primary amino groups with respect to n molecules of a polymer (A2) having two (meth) acryloyl groups in one end terminal region as shown by the following general formula (21) (n + 1) are reacted, one molecule of the polymer (C2) having two primary amino groups and 2n secondary amino groups can be obtained in a logarithm (n is a positive integer).

In the general formula (21), X ² is a part of the polymer (A2) excluding the (meth) acryloyloxy group, Y ² is a part of the polyamine (B2) excluding the primary amino group, R ⁶ is a hydrogen atom or a methyl group And n is a positive integer.

Further, for example, the number of diamines (B2) having two secondary amino groups may be determined for n molecules of the polymer (A2) having two (meth) acryloyl groups in one terminal end region as shown in the following general formula When n + 1 molecules are reacted, one molecule of the polymer (C2) having two secondary amino groups and 2n tertiary amino groups can be obtained in a logarithm (n is a positive integer).

In the general formula (22), X ² is a part of the polymer (A2) excluding the (meth) acryloyloxy group, Y ² is a part of the polyamine (B2) excluding the secondary amino group, R ⁶ is a hydrogen atom or a methyl group , R ⁸ is an alkyl group, and n is a positive integer.

It is assumed that the primary amino groups of the above four examples are higher in reactivity than the secondary amino group because they are considered to be in the logic state, but in reality, even if the primary amino group remains in the reaction conditions, the secondary amino group may react first . For this reason, the polymer (C2) having a structure different from that expected in some cases may be obtained. However, since the addition reaction proceeds almost stoichiometrically, most of the polymer (C2) having a desired structure can be obtained, and there is no problem in the subsequent reaction or the function as a final dispersant.

[Synthesis conditions]

(A2) having one or two (meth) acryloyl groups in one end terminal region and a polymer (C2) having an amino group in the polyamine (B2) having at least one primary and / or secondary amino group The Michael addition reaction is largely classified into a method in which 1) the whole amount is added and reacted, and 2) a method in which a solution composed of a polyamine (B2) and a solvent as required is placed in a flask and the polymer (A2) solution is added dropwise. It is preferable to apply the method of the above 2) in which the reaction control (molecular design control) is easier if the reaction can be carried out by appropriately selecting a method capable of stably carrying out the reaction.

The Michael reaction temperature of the present invention is preferably 70 DEG C or less. It is also preferably 60 DEG C or lower. When the reaction rate is high at 60 ° C and can not be controlled, it is more preferably 50 ° C or less. If it is higher than 70 ° C, it is difficult to control the reaction rate, and it tends to be difficult to obtain the polymer (C2) having a predetermined molecular weight and structure.

The blending ratio of the polymer (A2) having one or two (meth) acryloyl groups in the one terminal region and the polyamine (B2) having one or more primary and / or secondary amino groups is not particularly limited, And is arbitrarily selected according to the required performance. The end point of the reaction is determined by measuring the% of amine by titration.

[Dispersant having amino group and urea bond]

The polymer (G2) having a basic functional group constituting the composition of the present invention is a dispersant having an amino group and a urea bond and is a polyisocyanate having a primary or secondary amino group of the amino group-containing polymer (C2) and at least two isocyanate groups D2) can be obtained by reacting an isocyanate group. The primary or secondary amino group of the polymer (C2) having an amino group is partially or wholly formed of a urea bond by adjusting the amount of the polyisocyanate to be reacted, and the remainder is present as an amino group in the dispersant.

In addition, when the polymer (C2) having an amino group has a tertiary amino group in addition to the primary or secondary amino group, the tertiary amino group remains in the dispersant as it is without reacting with the isocyanate group.

For example, when one molecule of the diisocyanate (D2) is allowed to react with two molecules of the polymer (C2) having one primary amino group and one secondary amino group as shown in the following general formula (23) , A primary amino group reacts with an isocyanate group to form a urea bond, and a dispersant having four secondary amino groups and two urea bonds can be obtained. When W ¹ and W ² in the following general formula (23) have a tertiary amino group derived from a polyamine (B2) and / or a polymer (C2), the dispersant also has a tertiary amino group.

In the general formula (23), X ¹ is a part of the polymer (A2) which is a precursor of the polymer (C2) except for the (meth) acryloyloxy group, and W ¹ and W ² are polyamines ), R ⁶ is a hydrogen atom or a methyl group, and Z ¹ is a part of the polyisocyanate (D2) excluding an isocyanate group.

For example, when one molecule of the diisocyanate (D2) is reacted with two molecules of the polymer (C2) having one secondary amino group as shown in the following general formula (24), the secondary amino group Reacts with an isocyanate group to form a urea bond, and a dispersant having a urea bond can be obtained. When W ^{3 in the} following general formula (24) has a tertiary amino group derived from a polyamine (B2) and / or a polymer (C2), the dispersant also has a tertiary amino group. The dispersant does not have an amino group having an active hydrogen.

In the general formula (24), X ¹ is a part of the polymer (A2) which is a precursor of the polymer (C2), excluding the (meth) acryloyloxy group, and W ³ is a part of the polyamine (B2) which is a precursor of the polymer R ⁶ is a hydrogen atom or a methyl group, and Z ¹ is a part of the polyisocyanate (D2) excluding an isocyanate group.

(M + 1) molecules of the polymer (C2) having two primary amino groups and 2n secondary amino groups, which are the products of the general formula (23) as shown in the following general formula (25) When m molecules of isocyanate (D2) are reacted, a primary amino group reacts with an isocyanate group to form a urea bond, and a dispersant having two primary amino groups and two secondary amino groups (2 nm + 2n) and two urea bonds Can be obtained. When Y ² in the following general formula (25) has a tertiary amino group derived from the polyamine (B2) and / or the polymer (C2), the dispersant also has a tertiary amino group (n and m are positive integers).

In the general formula (25), X ² is a part of the polymer (A2) which is a precursor of the polymer (C2), excluding the (meth) acryloyloxy group, and Y ² is a part of the polyamine (B2) which is a precursor of the polymer class and in areas other than the amino group, W ⁴ is a portion other than the region having amino groups in the polymer (C2), R ⁶ is a hydrogen atom or a methyl group, Z ¹ is a portion except for an isocyanate group of polyisocyanate (D2), n and m is a positive integer.

Further, for example, a polymer obtained by reacting two molecules of a polyamine (B2) having one primary amino group and one molecule of a polymer (A2) having two (meth) acryloyl groups as shown in the following general formula (26) (M + 1) of the polymer (C2) having two secondary amino groups in the terminal end region of the polymer (A2), m molecules of the diisocyanate (D2) When reacted, in theory, the secondary amino group reacts with the isocyanate group to form a urea bond, and when viewed from the polyurea chain, a dispersant having two secondary amino groups in the terminal end region can be obtained (m is a positive Integer).

In the general formula (26), X ² is a part of the polymer (A2) which is a precursor of the polymer (C2) excluding the (meth) acryloyloxy group, Y ³ is a part of the polyamine (B2) W ⁵ is a portion excluding the portion having an amino group in the polymer (C 2), R ⁶ is a hydrogen atom or a methyl group, Z ¹ is a portion of the polyisocyanate (D2) excluding an isocyanate group, and m is a positive integer.

Theoretically, the above four examples assume that the primary amino group reacts more preferentially than the secondary amino group because it is more reactive than the secondary amino group. However, even when the primary amino group remains in the reaction condition, have. For this reason, a dispersant having a structure different from that expected in some cases may be obtained. However, since the reaction proceeds almost stoichiometrically, the polymer (C2) having the desired structure is obtained in most cases, and there is no problem in the function as a dispersant.

The molecular weight, the amino group (primary, secondary, and / or tertiary) and the amount of the urea bond can be adjusted by changing the reaction ratio between the polymer (C2) having an amino group and the polyisocyanate (D2)

[Polyisocyanate (D2)]

As the polyisocyanate (D2) to be used in the present invention, conventionally known ones can be used, but it is preferable that diisocyanate is used from the low viscosity effect of the dispersion. For example, aromatic diisocyanate (d21), aliphatic diisocyanate (d22) Aliphatic diisocyanate (d23), alicyclic diisocyanate (d24), dimer of these diisocyanates (uretodione), reaction products of these diisocyanate trimer (isocyanurate) with monoalcohol, and diisocyanates And a reaction product of a diol (urethane prepolymer of isocyanate of horseshoe).

Examples of the aromatic diisocyanate (d21) include xylylene diisocyanate, 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, Diphenyl ether diisocyanate, dianisidine diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, naphthylene diisocyanate and 1,3-bis Isocyanatoethyl) benzene, and the like.

Examples of the aliphatic isocyanate (d22) include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (hereinafter sometimes referred to as HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3 -Butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

Examples of the aromatic-aliphatic diisocyanate (d23) include ω, ω'-diisocyanate-1,3-dimethylbenzene, ω'-diisocyanate-1,4-dimethylbenzene, ω, ω'-diisocyanate- -Diethylbenzene, 1,4-tetramethylxylene diisocyanate, and 1,3-tetramethylxylene diisocyanate.

Examples of the alicyclic diisocyanate (d24) include 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate (hereinafter sometimes referred to as IPDI), 1,3-cyclopentane diisocyanate, 1,3- Hexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, and methyl-2,6-cyclohexane diisocyanate.

The diisocyanates (D2) listed above are not necessarily limited to these, and two or more diisocyanates may be used in combination.

As the diisocyanate (D2) used in the present invention, 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate (isophorone diisocyanate, IPDI) is preferable because it is egg yolk-denatured.

In order to increase the molecular weight of the dispersing agent, a polyisocyanate (d25) having three or more isocyanate groups in one molecule may be used, and aromatic polyisocyanate, aliphatic polyisocyanate, aromatic-aliphatic polyisocyanate and alicyclic polyisocyanate .

Specific examples of the polyisocyanate (d25) having three or more isocyanate groups per molecule include a trimer of the isocyanurate of the diisocyanate and a diisocyanate of the diisocyanate, a polyol adduct of the diisocyanate , Copolymers of two or more of these diisocyanates, aromatic triisocyanates, and polymeric aromatic isocyanate oligomers.

Examples of the polyisocyanate (d25) having three or more isocyanate groups in one molecule include isocyanurate of tolylene diisocyanate (hereinafter abbreviated as TDI), isophorone diisocyanate (hereinafter abbreviated as IPDI) Isocyanurate of 4,4'-diphenylmethane diisocyanate (hereinafter sometimes referred to as MDI) isocyanurate, hexamethylene diisocyanate (hereinafter referred to as &quot; , HDI, etc.), burette of HDI, trimethylol propane of HDI (hereinafter sometimes abbreviated as TMP) adduct, TDI TMP adduct, and TDI adduct Diisocyanate-modified products such as TDI / HDI copolymer;

Aromatic triisocyanates such as 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene and 4,4 ', 4 "-triphenylmethane triisocyanate, and the like;

And polymeric aromatic isocyanate oligomers such as polymethylene polyphenyl polyisocyanate (also called MDI oligomer).

[Synthesis conditions]

The reaction between the polymer (C2) having an amino group and the polyisocyanate (D2) is largely divided into 1) a case where the reaction is carried out by adding the whole amount and 2) a method in which the solution of the polymer (C2) is put into a flask and the polyisocyanate (D2) 2) is preferable in the case of precise measurement. The temperature of the urea reaction of the present invention is preferably 70 ° C or lower. It is more preferably 60 DEG C or less. When the reaction rate is high even at 60 ° C and can not be controlled, it is more preferably 50 ° C or less. When the temperature is higher than 70 ° C, it is difficult to control the reaction rate and it tends to be difficult to obtain a dispersant having a predetermined molecular weight and structure.

The mixing ratio of the polyisocyanate (D2) to the polymer (C2) having an amino group is such that the equivalent of the amino group (primary and secondary amino groups) having an active hydrogen of the polymer (C2) is [C2], the polyisocyanate (D2) [D2] / [C2] is preferably in the range of 0.25 to 1.00, and it is preferable to react all the isocyanate groups with the amino group having an active hydrogen. The design of the dispersant, More preferably in the range of 0.35 to 0.9 in view of the balance between the pigment and the pigment, and most preferably 0.5 to 0.8 in terms of the dispersion stability of the pigment dispersion using the dispersant as the final compound.

If the compounding equivalent ratio is less than 0.25, the urea bonding amount in the dispersant as the final product becomes small, and the dispersibility may be deteriorated. If the compounding ratio is greater than 1.00, an isocyanate group having a high reaction activity may remain to react with water or the like to increase the molecular weight and increase the viscosity, which is not preferable. When the compounding equivalent is 1.00, for example, in the reaction between the polyamine (C2) having two amino groups having active hydrogen and the diisocyanate (D2) having two isocyanate groups, the molecular weight becomes theoretically infinite, Lt; / RTI &gt;

Further, when primary and / or secondary amino groups (amino groups having active hydrogen) in addition to the tertiary amino group and urea bond are present in the dispersant skeleton, the adsorbability to the pigment is improved and the balance with the solubilization- The pigment dispersibility and the stability over time are also improved.

In addition, if the amino group having active hydrogen remains excessively large, problems such as the reaction with the acryloyl group of the polyfunctional monomer added when the resist ink is prepared exceeding the required amount of pigment adsorption, for example, arise.

Therefore, it is preferable to blend such that an amino group having an appropriate active hydrogen remains.

That is, when the compounding equivalent ratio is 0.35 to 0.9, preferably 0.5 to 0.8, as described above, the amino group having a tertiary amino group, the urea bond, the active hydrogen, and the solvent-affinity site are well balanced and exhibit excellent pigment dispersion stability.

The polymer (G2) having a basic functional group constituting the composition of the present invention comprises a first step of producing a polymer (A2) having one or two (meth) acryloyl groups in one terminal region,

(B1) of a (meth) acryloyl group of a polymer (A2) having one or two (meth) acryloyl groups in the one terminal region and a polyamine (B2) containing at least one primary and / And / or a polymer (C2) having an amino group reactive with a secondary amino group,

A third step of reacting an isocyanate group of a polyisocyanate (D2) containing a primary and / or secondary amino group of the polymer (C2) having an amino group and at least two isocyanate groups,

. &Lt; / RTI &gt;

The synthesis method and conditions of each step are as described above.

The weight average molecular weight (Mw) of the polymer (G2) having a basic functional group constituting the composition of the present invention is preferably 1,000 to 100,000, more preferably 1,500 to 50,000, and particularly preferably 2,000 to 30,000. If the weight average molecular weight is less than 1,000, the stability of the pigment dispersion may deteriorate. If the weight average molecular weight exceeds 100,000, the interaction between the resins becomes strong, and the viscosity of the pigment dispersion may increase. The amine value of the obtained dispersant is preferably 5 to 100 mgKOH / g, more preferably 10 to 70 mgKOH / g, and even more preferably 20 to 50 mgKOH / g. If the amine value is less than 5 mgKOH / g, the functional groups adsorbing to the pigment may be insufficient to contribute to the pigment dispersion. On the other hand, when the amine value is more than 100 mgKOH / g, aggregation occurs between the pigments, There is a case.

&Lt; Vinylamide &lt;

The compounded paste for a lithium secondary battery of the present invention may contain a vinylamide resin in order to obtain good dispersion and dispersion stability of the positive electrode active material. Vinylamide resins are generally known to have adsorptive interactions with anionic (anionic) species. The vinylamide resin does not strictly correspond to a resin having a basic functional group but is treated as a resin having a basic functional group in this specification because its pH is slightly basic.

The vinylamide resin to be used is not particularly limited, and examples thereof include polyvinylacetamide, polyacrylamide, polyvinylpyrrolidone, alkylated polyvinylpyrrolidone, graft copolymer of polyvinylpyrrolidone, and vinylpyrrolidone And copolymers with comonomers.

Examples of the comonomer copolymerizable with vinyl pyrrolidone include? -Olefins, vinyl acetate, ethyl acrylate, methyl acrylate, methyl methacrylate, dimethylaminomethyl methacrylate, acrylamide, methacrylamide, acrylonitrile, ethylene , Styrene, maleic anhydride, acrylic acid, vinylsulfate, vinyl chloride, vinylpyrrolidine, trimethylsiloxyvinylsilane, vinyl propionate, vinylcaprolactam, and methyl vinyl ketone.

Further, an acid-modified product obtained by treating the vinylamide resin with an organic acid or an inorganic acid can also be used.

Among the above-mentioned vinylamide resins, particularly preferred are a substantially neutral vinylamide resin such as polyvinylpyrrolidone, vinylpyrrolidone-1-butene copolymer or vinylpyrrolidone-styrene copolymer or polyvinylpyridine treated with an organic acid or inorganic acid An acid denatured product of lolidon is commonly used.

The reason why the vinylamide resin of the present invention is effective in dispersing the positive electrode active material is that since the solvent used is excellent in wettability with respect to a solvent in both water and an aqueous solvent and a solvent system, the interaction between the positive electrode active material and the solvent is smoothly promoted And the aggregation between the active materials becomes very small. Particularly, when a solvent having a high polarity is used, the dispersing effect becomes very high.

[Combined effects of vinylamide resin and various derivatives having a basic or acidic functional group]

In order to further obtain good dispersion and dispersion stability of the positive electrode active material, the compounded paste for a lithium secondary battery of the present invention is preferably used in combination with various derivatives having a basic or acidic functional group in the vinylamide resin. One of the effects of the various derivatives having a basic or acidic functional group (hereinafter, may be simply referred to as a derivative) is that since the vinylamide resin increases the wettability with the solvent, the further added derivative acts on the surface of the positive electrode active material It is considered that the dispersion progresses due to the synergistic effect. Among the positive electrode active materials, in the case of lithium iron phosphate bearing a carbon material, it is considered that since the hydrophobicity of the particle surface is high, the adsorption action effect of various derivatives having a functional group is further improved, thereby exerting a more dispersing effect.

Accordingly, in the present invention, by using the above-mentioned vinylamide resin and various derivatives having a basic or acidic functional group, good dispersion can be obtained without directly introducing a functional group (covalent bonding) to the surface of the positive electrode active material and without using a dispersion resin. As a result, good dispersion can be obtained without lowering the conductivity of the positive electrode active material. Also, by using the positive electrode material mixture paste for a lithium secondary battery of the present invention in which the positive electrode active material is well dispersed, a positive electrode in which the positive electrode active material is uniformly dispersed can be produced.

In addition, in the positive electrode using the positive electrode material mixture paste for a lithium secondary battery of the present invention, various derivatives having a functional group are present on the surface of the positive electrode active material, so that the wettability of the positive electrode active material with respect to the electrolyte is improved and the uniform dispersion effect described above is added. Is improved.

The vinylamide resin also functions as a binder for binding the positive electrode active material and the carbon material as the conductive auxiliary agent or for binding the carbon material as the positive electrode active material and the conductive auxiliary agent to the collector electrode. However, an organic dye derivative having a basic functional group, At least one derivative selected from the group consisting of a quinone derivative, an acridone derivative having a basic functional group and a triazine derivative having a basic functional group, or an organic coloring matter derivative having an acidic functional group and a triazine derivative having an acidic functional group The dispersion stability of the positive electrode active material and the adhesion of the positive electrode mixture layer can be further improved.

That is, adsorption of the vinylamide-based polymer onto the surface of the positive electrode active material is promoted by adsorption on the surface of the positive electrode active material while interacting with the above-mentioned derivative (for example, adsorption) on the surface of the positive electrode active material and the vinylamide- It is considered that the adhesion with the resin is improved and the dispersion stability of the positive electrode active material is improved by repulsion due to the steric hindrance of the vinylamide resin. In addition, adhesion between the positive electrode active material and a binder resin such as a polymer compound containing a fluorine atom in the molecule is also improved, so that a reduction in the amount of binder used can be expected.

The resin having a basic functional group is not limited to the three types described above but may be a polyvinyl-based, polyurethane-based, polyester-based, polyether-based, have. Two or more kinds of resins having these basic functional groups may be used in combination.

[Other commercially available basic functional group-containing resins]

The commercially available resin having a basic functional group is not particularly limited, and examples thereof include the following.

108, 109, 112, 116, 130, 161, 162, 163, 164, 166, 167, 168, 180, 182, 183, 184, 185, 2000, 2001 were used as the resins having basic functional groups of BYK Chemie. , 2050, 2070, 2150 or BYK-9077.

The resins having basic functional groups manufactured by Lubrizol Japan include SOLSPERSE 9000, 13240, 13650, 13940, 17000, 18000, 19000, 20000, 24000SC, 24000GR, 28000, 31845, 32000, 32500, 32600, 33500, 34750, 35100, 35200, 37500, 38500 or 39000.

The resins having basic functional groups of Efka Additives include EFKA 4008, 4009, 4010, 4015, 4020, 4046, 4047, 4050, 4055, 4060, 4080, 4300, 4330, 4400, 4401, 4402, 4403, 4406, 4500, 4550, 4560, 4570, 4580 or 4800.

Resins having basic functional groups of Ajinomoto Fine-Techno Co., Inc. include Ajisper PB711, Ajisper PB821 or Ajisper PB822.

Resins having basic functional groups made by Kusumoto Chemicals Ltd. include disparlon 1850, 1860 or DA-1401.

Examples of the resin having a basic functional group of KYOEISHA CHEMICAL Co., LTD include Florene DOPA-15B and Florene DOPA-17.

<II-1. Various derivatives having an acidic functional group>

In order to obtain good dispersion and dispersion stability of the positive electrode active material, the compound paste for a lithium secondary battery of the present invention is an organic compound having an acidic functional group, an organic dye derivative having an acidic functional group, or a derivative selected from one or more triazine derivatives having an acidic functional group .

In particular, it is preferable to use a triazine derivative represented by the following general formula (27) or an organic coloring matter derivative represented by the following general formula (30).

In the general formula (27)

X ¹⁰¹ is -NH-, -O-, -CONH-, -SO ₂ NH-, -CH ₂ NH-, -CH ₂ NHCOCH ₂ NH- or -X ¹⁰³ -Y ¹⁰¹ -X ¹⁰⁴ -

X ¹⁰² and X ¹⁰⁴ are each independently -NH- or -O-,

X ¹⁰³ is -CONH-, -SO ₂ NH-, -CH ₂ NH-, -NHCO- or -NHSO ₂ -

Y ¹⁰¹ is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group or a substituted or unsubstituted arylene group,

Z ¹⁰¹ is -SO ₃ M ¹⁰¹ , -COOM ¹⁰¹ or -P (O) (-OM ¹⁰¹ ) ₂ ,

M &lt; ¹⁰¹ &gt; is 1 equivalent of a cation of 1 to 3 valences (cation)

Q ¹⁰¹ is -OR ¹⁰² , -NH-R ¹⁰² , a halogen group, -X ¹⁰¹ -R ¹⁰¹ or -X ¹⁰² -Y ¹⁰¹ -Z ¹⁰¹ ,

R ¹⁰² is a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkenyl group,

n ¹⁰¹ is an integer of 1 to 4,

R ¹⁰¹ is an organic dye residue, a substituted or unsubstituted heterocyclic residue, a substituted or unsubstituted aromatic ring residue, or a group represented by the following formula (28).

In the general formula (28)

X ²⁰¹ is -NH- or -O-,

X ²⁰² and X ²⁰³ are each independently -NH-, -O-, -CONH-, -SO ₂ NH-, -CH ₂ NH- or -CH ₂ NHCOCH ₂ NH-,

R ²⁰¹ and R ²⁰² are each independently an organic pigment residue, a substituted or unsubstituted heterocyclic residue, a substituted or unsubstituted aromatic ring residue or -Y ²⁰¹ -Z ²⁰¹ ,

Y ²⁰¹ is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group or a substituted or unsubstituted arylene group,

Z ²⁰¹ is -SO ₃ M ²⁰¹ , -COOM ²⁰¹ or -P (O) (-OM ²⁰¹ ) ₂ ,

M &lt; ²⁰¹ &gt; is 1 equivalent of a 1 to 3-valent cation.

Examples of the organic dye residue represented by R ^{101 in the} general formula (27) and R ²⁰¹ and R ²⁰² in the general formula (28) include azo dyes such as diketopyrrolopyrrole dye, azo dye, azo dye, polyazo dye, Anthraquinone type dyes such as dyes, phthalocyanine dyes, diaminodianthraquinones, anthrapyrimidines, flavanthrone, anthanthrone, indanthrone, pyranthrone and biorantrone, quinacridone dyes, Based dye, a thioindigo dye, an isoindolinone dye, a quinophthalone dye, a threne dye, a metal complex system dye, and the like. Particularly, it is preferable to use an organic dye residue rather than a metal complex dye in order to enhance the effect of suppressing a short circuit of the battery due to metal. Among them, an azo dye, a diketopyrrolopyrrole dye, a non- metal phthalocyanine dye, It is preferable to use a coloring agent such as a chroman dye or a dioxazine dye because of excellent dispersibility.

Formula (27) R ^101, and formula 28 of R ²⁰¹ and R in the heterocyclic moiety and the aromatic ring residue shown by ^202, for example, thiophene, furan, pyridine, pyrazole, pyrrole, imidazole , Isoindolinone, benzoimidazolone, benzthiazole, benztriazole, indole, quinoline, carbazole, acridine, benzene, naphthalene, anthracene, fluorene, phenanthrene, . Particularly, it is preferable to use a heterocyclic residue containing at least one of S, N, and O heteroatoms because of its excellent dispersibility.

Y ^{101 in the} general formula (27) and Y ²⁰¹ in the general formula (28) represent a substituted or unsubstituted alkylene, alkenylene or arylene group having 20 or less carbon atoms, preferably a substituted or unsubstituted phenylene group, A biphenylene group, a naphthylene group or an alkylene group which may have a side chain having a carbon number of 10 or less.

The substituted or unsubstituted alkyl or alkenyl group represented by R ¹⁰² contained in Q ¹⁰¹ of the general formula (27) is preferably an alkyl group having 20 or less carbon atoms, more preferably an alkyl group having 10 or less carbon atoms . The alkyl group or alkenyl group having a substituent is one in which the hydrogen atom of the alkyl group or the alkenyl group is substituted with a halogen atom such as a fluorine atom, a chlorine atom or a bromine atom, a hydroxyl group or a mercapto group.

Of formula (27), M ¹⁰¹ and M ²⁰¹ in the formula (28) denotes a one equivalent of 1 to 3 valent cation, for example a hydrogen atom (proton), metal cation or quaternary any of the ammonium cation One. When the dispersant has two or more M's in the dispersant structure, M may be either a proton, a metal cation or a quaternary ammonium cation, or a combination thereof.

Examples of metals include lithium, sodium, potassium, calcium, barium, magnesium, aluminum, nickel, and cobalt.

Quaternary ammonium cation is a single compound or a mixture having a structure represented by general formula (29).

In the general formula (29), R ³⁰¹ , R ³⁰² , R ³⁰³ and R ³⁰⁴ are any of hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group or a substituted or unsubstituted aryl group.

R ³⁰¹ , R ³⁰² , R ³⁰³ and R ³⁰⁴ in the general formula (29) may be the same or different. When R ³⁰¹ , R ³⁰² , R ³⁰³ and R ³⁰⁴ have a carbon atom, the number of carbon atoms is 1 to 40, preferably 1 to 30, more preferably 1 to 20. When the number of carbon atoms exceeds 40, the conductivity of the electrode may be lowered.

Specific examples of the quaternary ammonium include dimethyl ammonium, trimethyl ammonium, diethyl ammonium, triethyl ammonium, hydroxyethyl ammonium, dihydroxyethyl ammonium, 2-ethylhexyl ammonium, dimethylaminopropyl ammonium, Ammonium, and the like, but are not limited thereto.

In the general formula (30)

X ⁴⁰¹ , a direct bond, -NH-, -O-, -CONH-, -SO ₂ NH-, -CH ₂ NH-, -CH ₂ NHCOCH ₂ NH-, -X ⁴⁰² -Y- or -X ⁴⁰² -YX ⁴⁰³ -

X ⁴⁰² is -CONH-, -SO ₂ NH-, -CH ₂ NH-, -NHCO- or -NHSO ₂ -

X ⁴⁰³ is -NH- or -O-,

Y ⁴⁰¹ is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group or a substituted or unsubstituted arylene group,

Z ⁴⁰¹ is -SO ₃ M ⁴⁰¹ , -COOM ⁴⁰¹ or -P (O) (-OM ⁴⁰¹ ) ₂ ,

M &lt; ⁴⁰¹ &gt; is 1 equivalent of a 1 to 3-valent cation,

R ⁴⁰¹ is an organic dye residue,

n ⁴⁰¹ is an integer of 1 to 4;

Examples of the organic dye residue represented by R ⁴⁰¹ in the general formula (30) include an azo dye such as diketopyrrolopyrrole dye, azo dye, disazo dye, polyazo dye, phthalocyanine dye, diamino dianthraquinone, Based dye, a perylene-based dye, a thioindigo-based dye, an isoindigo-based dye, a quinacridone-based dye, a dioxazine-based dye, a perylene-based dye, a perylene- An indolinone dye, an isoindolinone dye, a quinophthalone dye, a threne dye or a metal complex dye, and the like. The organic coloring matter moiety represented by R ⁴⁰¹ includes a light yellow anthraquinone moiety which is not generally called a coloring matter. Particularly, it is preferable to use an organic dye residue rather than a metal complex dye in order to enhance the effect of suppressing a short circuit of the battery due to metal. Among them, an azo dye, a diketopyrrolopyrrole dye, a non- metal phthalocyanine dye, It is preferable to use a coloring agent such as a chroman dye or a dioxazine dye because of excellent dispersibility.

M ⁴⁰¹ in the general formula (30) represents one equivalent of a cation of a valence of 1 to 3, and represents, for example, any one of a hydrogen atom (proton), a metal cation or a quaternary ammonium cation. When two or more M's are present in the dispersant structure, M ⁴⁰¹ may be either a proton, a metal cation or a quaternary ammonium cation, or a combination thereof.

Examples of metals include lithium, sodium, potassium, calcium, barium, magnesium, aluminum, nickel, and cobalt.

Quaternary ammonium cation is a single compound or a mixture having a structure represented by general formula (29).

In the general formula (29), R ³⁰¹ , R ³⁰² , R ³⁰³ and R ³⁰⁴ are any of hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group or a substituted or unsubstituted aryl group.

R ³⁰¹ , R ³⁰² , R ³⁰³ and R ³⁰⁴ in the general formula (29) may be the same or different. When R ³⁰¹ , R ³⁰² , R ³⁰³ and R ³⁰⁴ have a carbon atom, the number of carbon atoms is 1 to 40, preferably 1 to 30, more preferably 1 to 20. When the carbon number exceeds 40, the conductivity of the electrode may be lowered.

Specific examples of the quaternary ammonium include dimethyl ammonium, trimethyl ammonium, diethyl ammonium, triethyl ammonium, hydroxyethyl ammonium, dihydroxyethyl ammonium, 2-ethylhexyl ammonium, dimethylaminopropyl ammonium, Ammonium, and the like.

The method of synthesizing the above dispersant is not particularly limited, and examples of the dispersant include a method of synthesizing the dispersant described in Japanese Patent Publication Nos. 39-28884, 45-11026, 45-29755, 64-5070, 2004 -217842 or the like. The disclosures of which are incorporated herein by reference.

One of the effects of the various derivatives having an acidic functional group is considered to be that the added derivative exerts a dispersing effect by acting on the surface of the positive electrode active material (for example, adsorption).

Among the positive electrode active materials, in the case of lithium iron phosphate bearing a carbon material, it is considered that since the hydrophobicity of the surface of the particles is high, the adsorption action effect of various derivatives having an acidic functional group is further improved and the dispersion effect is further exerted.

That is, one or more derivatives selected from the group consisting of an organic dye derivative having an acidic functional group and a triazine derivative having an acidic functional group (hereinafter sometimes abbreviated as "a derivative having an acidic functional group" or "a derivative") A solvent or water, and the positive electrode active material is added and mixed in the solution. As a result, due to the polarity of the acidic functional group of the derivative in which the derivative acts on the positive electrode active material (for example, adsorption) and acts on the surface of the positive electrode active material (for example, adsorption), the wettability of the surface of the positive electrode active material with respect to the solvent or water And the coagulation of the positive electrode active material is considered to be facilitated.

The cationic functional group of the derivative and the cationic component such as amine (for example, formation of an ion pair (neutralization by neutralization) and polarization or dissociation of an ion pair (salt) It is considered that the repulsion is promoted and the dispersion stability of the positive electrode active material is further increased.

Further, adhesion between the positive electrode active material and the resin component is improved by the interaction (for example, acid-base interaction) between the acidic functional group of the derivative and the basic functional group of the resin having the basic functional group, Is expected to increase further.

It is also believed that the adhesion between the positive electrode active material and the fluorine atom-containing polymer compound or the like, which is a binder component, is improved through the resin having the basic functional group, so that the adhesion between the electrode current collector and the active material in the electrode mixture is also improved.

<II-2. Resins Having Acid Functional Groups>

The compounded paste for a lithium secondary battery of the present invention contains a resin having an acidic functional group in order to obtain good dispersion and dispersion stability of the positive electrode active material. Preferred acid functional groups are carboxyl group, sulfonic acid group and phosphoric acid group. From the viewpoint of dispersion stability, resins having an acidic functional group are preferably the three types of resins (H1) to (H3) shown below.

The resin having an acidic functional group also functions as a binder for binding the positive electrode active material and the carbon material as the conductive auxiliary agent or binding the carbon material as the positive electrode active material and the conductive auxiliary agent to the electrode current collector. Wherein the resin having an acidic functional group is at least one selected from the group consisting of an organic dye derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group and a triazine derivative having a basic functional group, The dispersion stability of the positive electrode active material and the adhesion of the positive electrode mixture layer can be further improved.

That is, an organic dye derivative having a basic functional group (eg, adsorption) on the surface of the positive electrode active material, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, or a basic functional group of a triazine derivative having a basic functional group An organic dye derivative having an acidic functional group (e.g. acid-base interaction) or basic functional group of a resin having an acidic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group or a basic functional group Is adsorbed on the surface of the positive electrode active material with interaction (for example, acid-base interaction) between the triazine derivative having the acid functional group and the resin having the acidic functional group. As a result, the adsorption of the resin having an acidic functional group to the surface of the positive electrode active material is promoted, so that the adhesion between the positive electrode active material and the resin component is improved, and the dispersion stability of the positive electrode active material is improved by repulsion due to steric hindrance of the resin. In addition, adhesion between the positive electrode active material and the polymer compound having a fluorine atom in the molecule, which is a binder component, is also improved, so that a reduction in the amount of the binder to be used can be expected. Hereinafter, three types of resins (H1) to (H3), which are known as resins having an acidic functional group in the present invention, will be described.

[Polyvinylidene fluoride (H1) having an acidic functional group]

The polyvinylidene fluoride resin (H1) having an acidic functional group is not particularly limited, but it is also possible to use polyvinylidene fluoride , WO2004-049475, JP 3121943, JP 3784494, etc., for example. Are incorporated herein by reference in their entirety. Hereinafter, a specific method of preparing the resin will be illustrated, but the term "monomer" in the following description means an ethylenically unsaturated monomer.

For example, a polyvinylidene fluoride resin having a sulfonic acid group may be selected from the group consisting of a homopolymer of vinylidene fluoride (homopolymer) or a monomer having fluorine other than vinylidene fluoride and vinylidene fluoride and other monomers having no fluorine Is obtained by sulfonating a copolymer (copolymer) with one or more kinds of monomers. Examples of the fluorine-containing monomer other than vinylidene fluoride include trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, and fluoroalkyl vinyl ether. The other monomers are monomers copolymerizable with vinylidene fluoride, and examples thereof include ethylene, chloroethylene, propylene, alkyl (meth) acrylate, and styrene. Sulfonation is carried out by substituting a sulfonic acid group for hydrogen in the polymerized units in the polyvinylidene fluoride unit by means of a sulfonating agent such as, for example, concentrated sulfuric acid, fuming sulfuric acid, chlorosulfonic acid, amide sulfuric acid, sulfur trioxide or triethyl phosphate complex.

For example, a polyvinylidene fluoride resin having a carboxyl group may be copolymerized with at least one monomer selected from the group consisting of monomers having vinylidene fluoride and carboxyl groups, monomers having fluorine other than vinylidene fluoride, and other monomers having no fluorine Can be obtained.

Examples of the monomer having a carboxyl group include unsaturated monobasic acids such as acrylic acid, methacrylic acid and crotonic acid, and unsaturated dibasic acids such as itaconic acid, maleic acid and citraconic acid (and their monoesters) .

Examples of the fluorine-containing monomer include trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, and fluoroalkyl vinyl ether.

The other monomers are monomers copolymerizable with vinylidene fluoride, and examples thereof include ethylene, chloroethylene, propylene, alkyl (meth) acrylate, and styrene.

Examples of commercially available polyvinylidene fluoride resins containing carboxyl groups include KF polymers W # 9100, W # 9200 and W # 9300 (manufactured by KUREHA CORPORATION), etc. For example, polyvinylidene fluoride Is obtained by copolymerizing at least one monomer selected from the group consisting of monomers having vinylidene fluoride and phosphoric acid groups, monomers having fluorine other than vinylidene fluoride, and other monomers having no fluorine.

Examples of the monomer having a phosphoric acid group include alkylene oxide-modified phosphoric acid (meth) acrylates, alkylene oxide-modified di (meth) acrylates, alkylene oxide-modified tri (meth) acrylates, alkylene oxide- , Di (meth) acrylates of an alkylene oxide-modified alkoxy acid, adducts obtained by reacting (meth) acrylate containing a glycidyl group with phosphoric acid, and the like.

Examples of the fluorine-containing monomer include trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, and fluoroalkyl vinyl ether. The other monomers are monomers copolymerizable with vinylidene fluoride, and examples thereof include ethylene, chloroethylene, propylene, alkyl (meth) acrylate, and styrene.

Also, the polyvinylidene fluoride resin having a phosphate group can be obtained by reacting a phosphorylating agent such as phosphoric acid, phosphorous pentoxide, phosphorous oxychloride, polyphosphoric acid or orthophosphoric acid, which is a phosphorylating agent, with a polyvinylidene fluoride resin having a hydroxyl group. A polyvinylidene fluoride resin having a hydroxyl group may be copolymerized with one or more monomers selected from the group consisting of monomers having vinylidene fluoride and hydroxyl groups and monomers having fluorine other than vinylidene fluoride and other monomers having no fluorine .

Examples of the monomer having a hydroxyl group include (meth) acrylates and allyl ethers. Examples of the (meth) acrylates include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) Hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (Meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycidyl (meth) acrylate, (Meth) acrylic acid esters of 1,1,1-trimethylol propane or glycerol, and the like.

Examples of the allyl ether having a hydroxyl group include ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, triethylene glycol monoallyl ether, polyethylene glycol monoallyl ether, propylene glycol monoacrylate, dipropylene glycol monoacrylate, tri Propylene glycol monoacrylate, polypropylene glycol monoacrylate, 1,2-butylene glycol monoallyl ether, 1,3-butylene glycol monoallyl ether, hexylene glycol monoallyl ether, octylene glycol monoallyl ether, trimethyl Trimethylolpropane diallyl ether, glycerin monoallyl ether, glycerine diallyl ether, pentaerythritol monoallyl ether, pentaerythritol triallyl ether, pentaerythritol diallyl ether, and the like.

Examples of the fluorine-containing monomer include trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, and fluoroalkyl vinyl ether.

The other monomers are monomers copolymerizable with vinylidene fluoride, and examples thereof include ethylene, chloroethylene, propylene, alkyl (meth) acrylate, and styrene.

The polyvinylidene fluoride resin (H1) having an acidic functional group preferably has a weight average molecular weight of 3,000 to 1,000,000. However, when only the polyvinylidene fluoride resin (H1) having an acidic functional group is used as the binder component, it is preferably 10,000 to 1,000,000. If the molecular weight is small, the resistance as a binder may decrease. Further, when the molecular weight is increased, the resistance of the binder is improved, but the viscosity of the binder itself is increased, so that the workability is deteriorated, and at the same time, the binder component may act as a flocculant and coagulate.

[Polyvinyl alcohol (H2) having an acidic functional group]

The first step for producing the polyvinyl alcohol (H2) having an acidic functional group is a step for producing a polyvinyl butyral having an acidic functional group in the presence of a compound (s) having two hydroxyl groups and one thiol group in the molecule as shown in the general formula (31) (A) having two hydroxyl groups at one terminal end by combining the unsaturated monomer (m) with radicals. (S) having two hydroxyl groups and one thiol group in the molecule acts as a chain transfer agent, and the S atom at the terminal of the solvent-affinity vinyl polymer moiety (M) in which the ethylenically unsaturated monomer (m) Whereby a vinyl polymer (a) having two hydroxyl groups introduced therein is synthesized.

Examples of the compound (s) having two hydroxyl groups and one thiol group in the molecule include 1-mercapto-1,1-methanediol, 1-mercapto-1,1-ethanediol, 3-mercapto- Propanediol, 2-mercapto-1,2-propanediol, 2-mercapto-2-methyl-1,3-propanediol, 2- Propanediol, 1-mercapto-2,2-propanediol, 2-mercaptoethyl-2-methyl-1,3-propanediol and 2-mercaptoethyl- And the like.

The compound (s) having two hydroxyl groups and one thiol group in the molecule is mixed with the polymerization initiator and the ethylenically unsaturated monomer (m) in accordance with the molecular weight of the objective vinyl polymer (a) ) Can be obtained. Preferably, bulk polymerization or solution polymerization is carried out using a compound (s) having 1 to 30 parts by weight of a hydroxyl group and a thiol group, based on 100 parts by weight of the ethylenically unsaturated monomer. The reaction temperature is 40 to 150 ° C, preferably 50 to 110 ° C, and the reaction time is 3 to 30 hours, preferably 5 to 20 hours.

When polymerizing, 0.001 to 5 parts by weight of a polymerization initiator may optionally be used per 100 parts by weight of the ethylenically unsaturated monomer (m). As the polymerization initiator, an azo compound and an organic peroxide may be used. Examples of the azo based compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane 1-carbonitrile) (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis 2-methylpropionate), 4,4'-azobis (4-cyanovaleric acid) and 2,2'-azobis (2-hydroxymethylpropionitrile), 2,2'-azobis [ 2- (2-imidazolin-2-yl) propane].

Examples of organic peroxides include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di (2- ethoxyethyl) peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide and diacetyl peroxide. These polymerization initiators may be used alone or in combination of two or more.

In the case of the solution polymerization, as the polymerization solvent, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, acetone, hexane, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate And N-methylpyrrolidone can be used, and the present invention is not limited thereto. Two or more of these polymerization solvents may be used in combination.

Examples of the ethylenically unsaturated monomer (m) include the following general ethylenically unsaturated monomer (m1). Examples of typical ethylenically unsaturated monomer (m1) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) (Meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, Acrylates;

(Meth) acrylates having an aliphatic ring such as cyclohexyl (meth) acrylate, isobonyl (meth) acrylate and dicyclopentanyl (meth) acrylate;

(Meth) acrylates having a heterocycle such as tetrahydrofurfuryl (meth) acrylate;

(Meth) acrylates having an aromatic ring such as phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate and phenoxy diethylene glycol (meth) acrylate;

Alkoxypolyalkylene glycol (meth) acrylates such as methoxypolypropylene glycol (meth) acrylate and ethoxypolyethylene glycol (meth) acrylate;

(Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl N-substituted (meth) acrylamides such as morpholine;

Amino group-containing (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate and N, N-diethylaminoethyl (meth) acrylate;

Nitriles such as (meth) acrylonitrile;

Styrene, such as styrene and? -Methylstyrene;

Vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether and isobutyl vinyl ether;

And fatty acid vils such as vinyl acetate and vinyl propionate. However, it is not particularly limited to the above-mentioned polymers, and two or more of them may be used in combination. If necessary, monomers shown below may be used in combination.

As an example of the ethylenically unsaturated monomer (m), a carboxyl group-containing ethylenically unsaturated monomer (m2) may be used in combination. Examples of the ethylenically unsaturated monomer (m2) having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, crotonic acid, acrylic acid dimer and caprolactone adducts of acrylic acid 1 to 5) and caprolactone adducts of methacrylic acid (the number of added mols is 1 to 5), and the like.

In the present invention, among the ethylenically unsaturated monomers (m) exemplified above, benzyl (meth) acrylate is preferably used in an amount of 20% by weight to 70% by weight of the entire monomer. If the amount is less than 20% by weight, the solvent affinity is lowered, and sufficient steric repulsion effect can not be obtained. In some cases, the pigment dispersibility is lowered. When the amount exceeds 70% by weight, solubility of the dispersant itself in the solvent is improved. Or the viscosity of the pigment composition may be increased due to agglomeration between solvent-friendly portions.

(M3) having a block isocyanate group, an ethylenically unsaturated monomer (m4) having an oxetane group, and an ethylenically unsaturated monomer having an ethylenically unsaturated monomer (m4) having a t-butyl group in addition to the ethylenically unsaturated monomer , And the unsaturated monomer (m5) can be used to prepare the vinyl polymer (a). By using these monomers, crosslinking functional groups (block isocyanate groups, oxetane groups and t-butyl groups, respectively) in the monomers are crosslinked by small fractions. Therefore, after a green body using the inkjet ink according to the present invention is thermally cured, It is possible to further improve the solvent resistance, heat resistance and alkali resistance.

Examples of the ethylenically unsaturated monomer (m3) having a block isocyanate group include Karenz MOI-BM and Karenz MOI-BP (manufactured by Showa Denko KK). Examples of the ethylenically unsaturated monomer (m4) having an oxetane group include ETERNACOLL OXMA (manufactured by Ube Industries, Ltd.) and the like. Examples of the ethylenically unsaturated monomer (m5) having a t-butyl group include t-butyl methacrylate and t-butyl acrylate.

The block isocyanate group having a monomer is more preferable because it causes a crosslinking reaction with a hydroxyl group when used in combination with a hydroxyl group. The oxetane group is more preferable because it causes a crosslinking reaction with a carboxyl group when used in combination with a carboxyl group. And when it is used in combination with oxetane group, crosslinking reaction with the oxetane group is more preferable.

When a carboxyl group is combined, a carboxyl group derived from an anhydride (b) of tetracarboxylic acid can be used as a curable site in the curable dispersant of the present invention, but an ethylenically unsaturated monomer having a carboxyl group is used in combination with an ethylenically unsaturated monomer (m2) The carboxyl group can be easily introduced into the curable dispersant.

Examples of the ethylenically unsaturated monomer (m2) having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, crotonic acid, acrylic acid dimer and caprolactone adducts of acrylic acid 1 to 5) and caprolactone adducts of methacrylic acid (the number of added mols is 1 to 5), and the like.

In addition, when a hydroxyl group is combined, a hydroxyl group can be introduced into the curing dispersant even when the ethylenically unsaturated monomer (m6) having a hydroxyl group is used in combination as an ethylenically unsaturated monomer.

The ethylenically unsaturated monomer (m6) having a hydroxyl group is not particularly limited as long as it is a monomer having an ethylenically unsaturated double bond having a hydroxyl group, and examples thereof include 2-hydroxyethyl (meth) acrylate, 2 (or 3) Hydroxyalkyl (meth) acrylates such as hydroxypropyl (meth) acrylate, 2 (or 3 or 4) -hydroxybutyl (meth) acrylate, cyclohexanedimethanol mono (meth) acrylate and glycerol Methacrylate;

(Hydroxymethyl) amide such as N- (2-hydroxyethyl) (meth) acrylamide, N- (2- hydroxypropyl) (Hydroxy) alkyl (meth) acrylamides;

Hydroxyalkyl vinyl ethers such as 2-hydroxyethyl vinyl ether, 2- (or 3-) hydroxypropyl vinyl ether and 2- (or 3- or 4-) hydroxybutyl vinyl ether;

And hydroxyalkyl allyl ethers such as 2-hydroxyethyl allyl ether, 2- (or 3-) hydroxypropyl allyl ether and 2- (or 3- or 4-) hydroxybutyl allyl ether.

Further, an alkylene oxide or lactone is added to the above hydroxyalkyl (meth) acrylates, N- (hydroxyalkyl) (meth) acrylamides, hydroxyalkyl vinyl ethers and hydroxyalkyl allyl ethers to obtain Can also be used as an ethylenically unsaturated monomer having a hydroxyl group used in the present invention. Examples of the alkylene oxide to be added include ethylene oxide, propylene oxide, 1,2-, 1,4-, 2,3- or 1,3-butylene oxide, and a combination of two or more thereof. When two or more kinds of alkylene oxides are used in combination, the bonding type may be random and / or block. As the added lactone,? -Valerolactone,? -Caprolactone,? -Caprolactone substituted with an alkyl group having 1 to 6 carbon atoms, and a combination of two or more thereof are used. It may be one obtained by adding both an alkylene oxide and a lactone.

In the present invention, it is also possible to introduce an unsaturated bond into the vinyl polymer (a). Examples of the method for introducing an unsaturated bond into the vinyl polymer (a) include a method of introducing a hydroxyl group into the vinyl polymer (a) and then reacting the ethylenically unsaturated monomer (m7) having an isocyanate group, (M8) having an epoxy group, and a method in which an epoxy group is introduced into the vinyl polymer (a) and then an ethylenically unsaturated monomer (m2) having a carboxyl group is reacted .

Examples of the ethylenically unsaturated monomer (m7) having an isocyanate group include Karenz MOI (Showa Denko KK 2-methacryloyloxyethyl isocyanate) and Karenz AOI (Showa Denko KK 2-acryloyloxyethyl isocyanate) . Examples of the ethylenically unsaturated monomer (m8) having an epoxy group include glycidyl (meth) acrylate and CYCLOMER M100 (Daicel Chemical Industries Limited, 3,4-epoxycyclohexyl (meth) acrylate).

The second step for producing the polyvinylic acid (H2) having an acidic functional group is a step of reacting the vinyl polymer (a) having two hydroxyl groups at one end obtained in the first step and the vinyl polymer And the tetracarboxylic acid is reacted with the anhydride (b).

When the molar ratio of the vinyl polymer (a) having two hydroxyl groups at one terminal is? And the molar ratio of the tetracarboxylic acid anhydride (b) is?, The molecular weight increases to? Or the ratio of alpha / beta is changed to alpha &lt; beta to control the target molecular weight in many cases. For example, in the case of? =? + 1, the polyvinyl resin (H2-1) having an acidic functional group can be stably synthesized without increasing the molecular weight beyond that of the hydroxyl group at both terminals. On the other hand, in the case of? =? + 1, the polyvinylidene (H2-2) having an acidic functional group whose terminal is a carboxyl group can be synthesized because the terminal ends become acid anhydride groups and the stability becomes worse have.

Next, each component in the second production process of the polyvinyl alcohol (H2) having an acidic functional group will be described.

The tetracarboxylic acid dianhydride (b) used in the present invention reacts with the vinyl polymer (a) having two hydroxyl groups at one terminal end to form an ester bond and to retain the pendant carboxyl group on the resulting polyester main chain . When the acid anhydride group remaining in the product of the general formula (32) is hydrolyzed, the product by this reaction is converted into X ⁰ Has two or three carboxyl groups in the moiety, and the plurality of carboxyl groups is effective as a site of adsorption to the carbon material as the conductive auxiliary agent.

However, when there is only one carboxyl group bonded to X ⁰ (outside the scope of the present invention), it is not preferable because it can not exhibit high dispersibility, fluidity and storage stability. X ⁰ in the present invention is a reaction residue after the tetracarboxylic acid anhydride (b) is reacted with the vinyl polymer (a) having two hydroxyl groups at one terminal. Is preferably a reaction residue after the tetracarboxylic acid dianhydride represented by the following general formula (33) or (34) is reacted with the vinyl polymer (a) having a hydroxyl group.

In the above general formula (33), k is 1 or 2.

In the general formula (34), Q ⁰ represents a direct bond, -O-, -CO-, -COOCH ₂ CH ₂ OCO-, -SO ₂ -, -C (CF ₃ ) ₂ - Or (36).

In the present invention, by reacting the vinyl polymer (a) having two hydroxyl groups at one end with the tetracarboxylic acid anhydride (b), a plurality of carboxyl group moieties bonded to X ⁰ in the product of the formula (32) Functions as an adsorption portion to the positive electrode active material, and the vinyl polymer portion functions as a solvent-affinity portion.

The weight average molecular weight of the vinyl polymer (a) having two hydroxyl groups at one terminal end is preferably from 1,000 to 10,000, and this portion becomes an affinity portion to the solvent in which the dispersion medium is a dispersion medium. When the weight average molecular weight of the vinyl polymer (a) is less than 1,000, the effect of steric repulsion due to the solvent-affinitive portion is reduced, and it is difficult to prevent the aggregation of the carbon material, which is the conductive additive, so that the dispersion stability may be insufficient. On the other hand, if it exceeds 10,000, the absolute amount of the solvent-affinity portion increases, and the effect of dispersibility itself may decrease. In addition, the viscosity of the dispersion may be increased.

The vinyl polymer (a) is easy to adjust the molecular weight to the above range, and also has good compatibility with a solvent. As described in the first step of the polyvinyl alcohol (H2) having an acidic functional group, the weight average molecular weight of the vinyl polymer (a) having two hydroxyl groups at one terminal end is preferably within the range of The weight of the compound (s) having two hydroxyl groups and one thiol group, the reaction temperature, the reaction time, the weight of the polymerization initiator to be used, as required for the ethylenically unsaturated monomer (m) The kind of the polymerization solvent and the concentration of the ethylenically unsaturated monomer (m) in the polymerization can be controlled.

As the tetracarboxylic acid dianhydride (b)

1,2,3,4-butanetetracarboxylic anhydride, 1,2,3,4-cyclobutanetetracarboxylic anhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic anhydride, 1,2,3,4-cyclopentanetetracarboxylic anhydride, 2,3,5-tricarboxycyclopentyl acetic anhydride, 3,5,6-tricarboxy norbornane-2-acetic anhydride, 5-tetrahydrofuran tetracarboxylic anhydride, 5- (2,5-dioxotetrahydrofuran) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride and bicyclo [ ] -Octo-7-ene-2,3,5,6-tetracarboxylic acid anhydride; And

Pyromellitic anhydride, ethylene glycol dianhydride trimellitic acid ester, propylene glycol dianhydride trimellitic acid ester, butylene glycol dianhydride trimellitic acid ester, 3,3'-4,4'-benzophenone tetracarboxylic acid anhydride, 3,3 ', 4,4'-biphenylsulfonetetracarboxylic anhydride, 1,4,5,8-naphthalenetetracarboxylic anhydride, 2,3,6,7-naphthalenetetracarboxylic anhydride, 3,3' , 4,4'-biphenyl ether tetracarboxylic anhydride, 3,3 ', 4,4'-dimethyldiphenylsilane tetracarboxylic anhydride, 3,3', 4,4'-tetraphenylsilane tetracarboxylic anhydride , 1,2,3,4-furantetracarboxylic anhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide anhydride, 4,4'-bis (3,4- 3,3 ', 4,4'-perfluoroisopropylidene diphthalic anhydride, 3, 4'-bis (3,4-dicarboxyphenoxy) diphenylpropane anhydride, , 3 ', 4,4'-biphenyltetracarboxylic anhydride, bis Bis (triphenylphthalic acid) anhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether anhydride, bisphenol-bis (triphenylphthalic acid) anhydride, Diphenylmethane anhydride, 9,9-bis (3,4-dicarboxyphenyl) fluorene anhydride, 9,9-bis [4- (3,4- Carboxyphenoxy) phenyl] fluorene acid anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic anhydride and 3,4-dicarboxy- And aromatic tetracarboxylic anhydrides such as tetrahydro-6-methyl-1-naphthalene succinic anhydride.

The tetracarboxylic acid dianhydride (b) usable in the present invention is not limited to the above-exemplified compounds, and any structure may be used provided that the tetracarboxylic acid dianhydride (b) has two carboxylic anhydride groups. These may be used alone or in combination. Also preferably used in the present invention is an aromatic tetracarboxylic acid anhydride represented by the general formula (34) or (35) from the viewpoint of lowering the viscosity of the dispersion of the positive electrode active material, more preferably an aromatic ring And the tetracarboxylic anhydride having two or more carbon atoms. Further, a compound having one carboxylic anhydride group or a compound having three or more carboxylic anhydride groups may be used in combination in the molecule.

The catalyst used in the second step of preparing the polyvinyl alcohol (H2) having an acidic functional group may be a known catalyst. As the catalyst, a tertiary amine compound is preferable, and examples thereof include triethylamine, triethylenediamine, N, N-dimethylbenzylamine, N-methylmorpholine, 1,8-diazabicyclo- [5.4.0] -7-undecene and 1,5-diazabicyclo- [4.3.0] -5-nonene.

The polyvinyl alcohol (H2) having an acidic functional group which can be used in the present invention can be produced by using only the raw materials described above, but it is preferable to use a solvent to avoid problems such as high viscosity and non-uniform reaction. As the solvent, known ones can be used. For example, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, toluene, xylene, acetonitrile, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, Ralidon, and the like. The solvent used in the reaction may be removed by an operation such as distillation after completion of the reaction, or may be used as a part of the product as it is.

The polyvinyl resin (H2) having an acidic functional group usable in the present invention can be obtained by reacting a vinyl polymer (a) having two hydroxyl groups at one terminal and an anhydride (b) of tetracarboxylic acid. The molar ratio of the acid anhydride group in the tetracarboxylic acid anhydride (b) to the hydroxyl group in the vinyl polymer (a) is preferably 2? (?), And the molar ratio of the tetracarboxylic acid anhydride (b) / 2? =? /? = 0.3 to 1.2, more preferably? /? = 0.5 to 1.0, and most preferably? /? = 0.6 to 0.8. In the case of reacting with? /?> 1, the remaining acid anhydride group may be used by hydrolysis with a necessary amount of water. If it is less than 0.3, the acid anhydride residues as the adsorbed portion to the positive electrode active material may be decreased, and the acid value of the resin may be lowered. On the other hand, if it exceeds 1.2, the polyester tends to have a higher molecular weight, and when used as a positive electrode material mixture paste for a lithium secondary battery, the interaction between the resins increases, and conversely viscosity increases.

The reaction temperature of the second step of the polyvinyl alcohol (H2) having an acidic functional group is 80 ° C to 180 ° C, preferably 90 ° C to 160 ° C. When the reaction temperature is lower than 80 ° C, the reaction rate is slow. At 180 ° C or higher, the carboxyl group is esterified to lower the acid value and cause gelation. It is ideal to stop the reaction until the absorption of the acid anhydride disappears by infrared absorption. However, even when the acid value of the polyester is in the range of 5 to 200 or when the hydroxyl value is in the range of 20 to 200 do.

The weight average molecular weight of the obtained polyvinyl alcohol (H2) having an acidic functional group is preferably 2,000 to 25,000. If the weight average molecular weight is less than 2,000, the stability of the positive electrode material mixture paste for a lithium secondary battery may deteriorate. On the other hand, if it exceeds 25,000, the interaction between the resins becomes strong and the viscosity of the positive electrode material mixture paste for a lithium secondary battery may increase. The acid value of the obtained polyvinyl alcohol (H2) having an acidic functional group is preferably 5 to 200 mgKOH / g. More preferably 5 to 150 mg KOH / g, particularly preferably 5 to 100 mg KOH / g. When the acid value is less than 5, the ability to adsorb to the positive electrode active material decreases, which may cause problems in dispersibility. On the other hand, if it exceeds 200 mgKOH / g, the interaction between the resins becomes strong, and the viscosity of the positive electrode material mixture paste for a lithium secondary battery may be increased.

[Polyester resin (H3) having an acidic functional group]

The chemical structure and the production method of the polyester resin (H3) having an acidic functional group usable in the present invention are not particularly limited as far as they have a structure represented by the following general formula (37). The production method thereof includes, for example, a first step of producing a polyester having a hydroxyl group at one terminal end by ring-opening polymerization of a lactone with a monoalcohol as an initiator, and a step of reacting a polyester having a hydroxyl group and a tetracarboxylic acid And a second step of reacting an anhydride.

In general formula (37):

(HOOC-) _m -R ²¹ - (-COO- [-R ²³ -COO-] _n -R ²² ) _t

In the general formula (37), R ²¹ is a tetravalent tetracarboxylic acid compound residue, R ²² is a monoalcohol residue, R ²³ is a lactone residue, m is 2 or 3, and n is an integer of 1 to 50 , and t is (4-m).

In the present invention, a group of formula (38) to (42) to the polyester resins (H3) is R ²¹ to the desired compound having an acidic functional group represented by general formula (37) described below, R ²² is An aliphatic alkyl group having 8 to 20 carbon atoms or a terminal ether group or ester polyoxyalkylene group having a molecular weight of 200 to 1500 (2 to 4 carbon atoms in the alkylene moiety), R ²³ is a hexamethylene group, a pentamethylene group, An alkyl-substituted hexamethylene group, m is 2 or 3, n is an integer of 3 to 20, and t is (4-m).

In the polyester resin (H3) having an acidic functional group represented by the general formula (37), R ²¹ is preferably any one of groups represented by the following general formulas (38) to (40).

In the general formula (40), A ⁰ is a direct _{bond, -O-, -CO-, -COOCH 2 CH} 2 OCO-, -SO 2 -, -C (CH 3) 2 -, -C (CF 3) ₂ - or a group represented by the following general formula (41) or (42).

The monoalcohol which can be used in the production of the polyester resin (H3) having an acidic functional group is not particularly limited as long as it is a compound having one hydroxyl group. Examples of the aliphatic monoalcohol include linear or branched, substituted or unsubstituted saturated aliphatic monohydric alcohols having 1 to 30 carbon atoms (more preferably 1 to 25 carbon atoms), or aliphatic monohydric alcohols having 1 to 30 carbon atoms And preferably a substituted or unsubstituted saturated alicyclic monohydric alcohol having 1 to 25 carbon atoms. The substituent of the saturated aliphatic monoalcohol or the saturated alicyclic monoalcohol includes, for example, a carboxyl group.

Examples of aliphatic monoalcohols include alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, isobutanol, tert-butanol, 1-pentanol, isopentanol, 1-heptanol, 1-dodecanol, 1-myristyl alcohol, cetyl alcohol, 1-stearoyl alcohol, 1-heptanol, 1-octanol, isooctanol, 2-ethylhexanol, Allyl alcohol, isostearyl alcohol, 2-octyldecanol, 2-octyldodecanol, 2-hexyldecanol, behenyl alcohol and oleyl alcohol. The alicyclic monoalcohols include, for example, cyclohexanol.

The aliphatic monohydric alcohol is preferably a branched aliphatic monohydric alcohol. For example, a branched aliphatic monohydric alcohol such as 2-ethylhexanol, isostearyl alcohol, 2-octyldecanol, 2-octyldodecanol and 2-hexyldecanol To 20% by weight.

As the monoalcohol, substituted or unsubstituted aromatic monoalcohols having 6 to 30 carbon atoms (more preferably 6 to 25 carbon atoms) such as phenol or cumylphenol may be used. Also, a saturated aliphatic monoalcohol having an aliphatic group having 1 to 6 carbon atoms and substituted with an aromatic group having 6 to 10 carbon atoms, such as benzyl alcohol, may be used.

Further, a monoalkylene glycol monoether having a hydroxyl group at one end with a mono alcohol or a polyalkylene glycol monoether having a hydroxyl group at one end may be used. These monoalkyleneglycol monoethers or polyalkylene glycol monoethers are preferably mono or polyethylene glycols or alkyl monoethers having 1 to 8 carbon atoms of mono or polypropylene glycol. Specific examples thereof include ethylene glycol mono Ethylene glycol monoethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, Propylene glycol monohexyl ether, propylene glycol mono-2-ethylhexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monopropyl ether, Glycol monobutyl Diethylene glycol monohexyl ether, diethylene glycol mono-2-ethylhexyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipropylene Glycol monohexyl ether, dipropylene glycol mono-2-ethylhexyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, triethylene glycol monohexyl ether , Triethylene glycol mono-2-ethylhexyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, tripropylene glycol monobutyl ether, tripropylene glycol monohexyl ether, tripropylene glycol Mono-2-ethylhexyl Diethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monopropyl ether, tetraethylene glycol monobutyl ether, tetraethylene glycol monohexyl ether, tetraethylene glycol mono-2-ethylhexyl ether, Glycol monomethyl ether, tetrapropylene glycol monoethyl ether, tetrapropylene glycol monopropyl ether, tetrapropylene glycol monobutyl ether, tetrapropylene glycol monohexyl ether, tetrapropylene glycol mono-2-ethylhexyl ether and tetradiethylene glycol monomethyl And alkylene glycol monoalkyl ethers such as ether.

The monoalcohol which can be used in the production of the polyester resin (H3) having an acidic functional group includes a monoalcohol having one or more ethylenic unsaturated double bonds. Examples of the ethylenically unsaturated double bond include a vinyl group and a (meth) acryloyl group, and a (meth) acryloyl group is preferable. These may be compounds having different kinds of double bonds in one compound.

As the monoalcohol having an ethylenically unsaturated double bond, for example, an unsaturated monoalcohol compound having one, two, or three or more ethylenically unsaturated double bonds can be used. Examples of the monoalcohol having one ethylenically unsaturated double bond include hydroxyalkyl esters having 1 to 8 carbon atoms of (meth) acrylic acid, such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-hydroxybutyl - (hydroxymethyl) acrylate, 2-hydroxy-3-phenoxypropyl acrylate and 1,4-cyclohexanedimethanol mono (meth) acrylate.

Examples of the monoalcohol having two ethylenically unsaturated double bonds include 2-hydroxy-3-acryloyloxypropyl methacrylate or glycerin di (meth) acrylate. Examples of the monoalcohol having three ethylenically unsaturated double bonds include pentaerythritol triacrylate and dipentaerythritol pentaacrylate such as monoalcohol having five ethylenically unsaturated double bonds.

Alcohols obtained by addition of an alkylene oxide to the hydroxyl groups of monoalcohols having an aliphatic monoalcohol, an aromatic monoalcohol and an ethylenically unsaturated double bond as described above as an initiator, that is, alcohols obtained by etherification or esterification of one terminal The alkylene glycol can also be used in the production of a polyester resin (H3) having an acidic functional group. The alkylene oxides to be used in the addition polymerization include, for example, ethylene oxide, propylene oxide or 1,2-, 1,4-, 2,3- or 1,3-butylene oxide or mixtures of two or more thereof Can be used. When two or more kinds of alkylene oxides are used in combination, the bonding type may be random and / or block. The number of additions of alkylene oxide is usually 1 to 300, preferably 2 to 250, and particularly preferably 5 to 100 in one molecule.

The addition of the alkylene oxide can be carried out at a temperature of 100 to 200 DEG C in the presence of a known method such as an alkali catalyst. Commercial products of the addition polymerization product thus obtained include the Uniox series manufactured by NIPPON OIL & FATS CO LTD or the Blenmer series manufactured by NIPPON OIL & FATS CO LTD.

For example, Uniox M-400, M-550, M-2000, Blenmer PE-90, PE-200, PE-350, AE-90, AE- PP-800, AP-150, AP-400, AP-550, AP-800, 50PEP-300, 70PEP-350B, AEP series, 55PET-400, 30PET- 50PPT-800, 70PPT-800, APT series, 10PPB-500B and 10APB-500B.

The monohydric alcohol which can be used in the production of the polyester resin (H3) having an acidic functional group is not limited to the above example, and any compound may be used as long as it is a compound having one hydroxyl group. Or more.

Among the above-mentioned monoalcohols, for example, 4-methyl-2-pentanol, isopentanol, isooctanol, 2-ethylhexanol, isononanol, isostearyl alcohol, 2-octyldecanol, Or a branched alkylene glycol having a hydroxyl group at one end is used as a branched aliphatic monoalcohol such as 2-hexyldecanol or the like, crystallinity lowers and a liquid state may be obtained at room temperature. Therefore, workability and compatibility with other resins .

By ring-opening polymerization of the lactone with the monoalcohol as an initiator, a polyester having a hydroxyl group at one end and usable in the production of the resinous dispersant can be obtained. The lactone that can be used in the ring-opening polymerization is preferably a lactone of 4-membered to 10-membered rings, more preferably 5-membered to 7-membered rings, and the ring-constituting carbon atoms may be substituted or unsubstituted. Examples of the substituent of the ring carbon atom include an alkyl group having 1 to 4 carbon atoms. Condensation lactones with unsaturated lactones or aromatic compounds (e.g., benzene) containing one or more ethylene bonds in the ring may also be used.

Specific examples of the lactone include? -Butyrolactone,? -Butyrolactone,? -Valerolactone,? -Valerolactone,? -Caprolactone,? -Caprolactone and alkyl-substituted? -Caprolactone Among them, it is preferable to use δ-valerolactone, ε-caprolactone or alkyl-substituted ε-caprolactone in terms of ring-opening polymerization. Examples of the alkyl substituent include an alkyl group having 1 to 4 carbon atoms, particularly a methyl group or an ethyl group, and these alkyl substituents may be substituted with one or more of these alkyl substituents.

The lactone is not limited to the above examples and may be used alone, or two or more kinds of lactones may be used in combination. The use of two or more kinds is preferable in view of workability and compatibility with other resins because there are cases where the crystallinity decreases and becomes liquid at room temperature.

The ring-opening polymerization of the monoalcohol with the lactone can be carried out in a nitrogen stream by adding the monoalcohol, the lactone, and the polymerization catalyst into a reactor in which a dehydration tube and a condenser are connected, in a known manner. When a monohydric alcohol having a low boiling point is used as the monoalcohol, it can be reacted under pressure using an autoclave. When a compound having an ethylenically unsaturated double bond is used as the monoalcohol, it is preferable to add a polymerization inhibitor and conduct the reaction under the flow of dry air.

The molar number of addition of the lactone to 1 mole of the monoalcohol is 1 to 50 moles, preferably 3 to 20 moles, and most preferably 4 to 16 moles. If the addition mole number is less than 1 mole, the effect of dispersing the positive electrode active material can not be obtained. If the addition mole number is more than 50 moles, the molecular weight becomes too large, and the dispersibility of the positive electrode active material and the fluidity of the positive electrode material mixture paste for lithium secondary battery are decreased.

Examples of the polymerization catalyst for ring opening polymerization include tetramethylammonium chloride, tetrabutylammonium chloride, tetramethylammonium bromide, tetrabutylammonium bromide, tetramethylammonium iodide, tetrabutylammonium iodide, benzyltrimethylammonium chloride, benzyltrimethylammonium Quaternary ammonium salts such as bromide and benzyltrimethylammonium iodide; Tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetrabutylphosphonium iodide, benzyltrimethylphosphonium chloride, benzyltrimethylphosphonium bromide, benzyltrimethylsilyl chloride, benzyltrimethylphosphonium chloride, benzyltrimethylphosphonium chloride, Quaternary phosphonium salts such as phosphonium iodide, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide and tetraphenylphosphonium iodide; Phosphorus compounds such as triphenylphosphine; Organic carboxylic acid salts such as potassium acetate, sodium acetate, potassium benzoate and sodium benzoate; Alkali metal alcoholates such as sodium alcoholate and potassium alcoholate; Tertiary amines; Organotin compounds; Organoaluminum compounds; Organic titanate compounds; And zinc compounds such as zinc chloride. The amount of the catalyst to be used is 0.1 ppm to 3000 ppm, preferably 1 ppm to 1000 ppm. When the amount of the catalyst is 3000 ppm or more, the color of the polyester resin (H3) having an acidic functional group is increased, which adversely affects the stability of the product. Conversely, when the amount of the catalyst used is 0.1 ppm or less, the ring-opening polymerization rate of the cyclic ester is very slow, which is not preferable.

The ring-opening polymerization reaction may be carried out in the absence of solvent or a suitable dehydrated organic solvent. The solvent used in the ring-opening polymerization reaction may be removed by an operation such as distillation after the completion of the reaction, or may be directly used as a part of the composition for a battery.

The ring-opening polymerization reaction is preferably carried out at a temperature in the range of 100 占 폚 to 220 占 폚, more preferably 110 占 폚 to 210 占 폚. When the reaction temperature is lower than 100 ° C, the reaction rate is very slow. When the reaction temperature is higher than 210 ° C, a side reaction other than the addition reaction of the lactone such as decomposition of the lactone adduct into the lactone monomer, the formation of the cyclic lactone dimer and the trimmer easy.

Examples of the radical polymerization inhibitor used in the case of using a monoalcohol having an ethylenically unsaturated double bond include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, p-benzoquinone, 2,4-dimethyl-6-t-butyl Phenol and phenothiazine. These can be used alone or in combination. The amount of the compound to be used is preferably 0.01% to 6%, more preferably 0.05% to 1.0%.

The polyester resin (H3) having an acidic functional group used in the present invention is obtained by reacting the hydroxyl group of a polyester having a hydroxyl group at one terminal end with the anhydride of the tetracarboxylic acid obtained in the first step ).

Examples of the tetracarboxylic acid dianhydride used in the second step include aliphatic tetracarboxylic acid dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, heterocyclic tetracarboxylic dianhydride and polycyclic tetracarboxylic acid dianhydride .

Specifically,

Aliphatic tetracarboxylic acid dianhydride such as 1,2,3,4-butanetetracarboxylic dianhydride;

1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracar 3, 5-tricarboxycyclopentyl acetic acid dianhydride, 3,5,6-tricarboxy norbornane-2-acetic acid dianhydride, and bicyclo [2,2,2] -octo- Alicyclic tetracarboxylic acid dianhydride such as 2,3,5,6-tetracarboxylic dianhydride; And

2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride and 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride Of a heterocyclic tetracarboxylic acid dianhydride.

Further, it is also possible to use pyromellitic acid dianhydride, ethylene glycol dianhydride trimellitic acid ester, propylene glycol dianhydride trimellitic acid ester, butylene glycol dianhydride trimellitic acid ester, 3,3 ', 4,4'-benzophenonetetracar Examples of the organic acid anhydride include 3,3 ', 4,4'-biphenylsulfonetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid Dianhydride, 3,3 ', 4,4'-biphenyl ether tetracarboxylic acid dianhydride, 3,3', 4,4'-dimethyldiphenylsilane tetracarboxylic acid dianhydride, 3,3 ', 4,4 4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ', 4,4'-bis '-Perfluoroisopropylidene diphthalic acid dianhydride, 3,3', 4,4'-biphenyl Bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) anhydride, tetracarboxylic acid dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, (Triphenylphthalic acid) -4,4'-diphenylmethane dianhydride, 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride, 9,4'-diphenyl ether dianhydride, Aromatic tetracarboxylic acid dianhydride such as 9-bis [4- (3,4-dicarboxyphenoxy) phenyl] fluorene dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro- -Naphthalene succinic anhydride and polycyclic tetracarboxylic dianhydrides such as 3,4-dicarboxy-1,2,3,4-tetrahydro-6-methyl-1-naphthalene succinic anhydride.

As the aromatic tetracarboxylic acid dianhydride, an aromatic tetracarboxylic acid dianhydride having at least two aromatic rings is preferable, and particularly, 3,3 ', 4,4'-biphenyltetracarboxylic anhydride, ethylene glycol dianhydride Mellitic acid ester and 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride are preferable.

The tetracarboxylic acid dianhydride which can be used in the production of the polyester resin (H3) having an acidic functional group is not limited to the above-exemplified compounds, and any structure may be used so long as it has two carboxylic anhydride moieties in the molecule. These may be used alone or in combination. Further, the tetracarboxylic acid dianhydride which can be suitably used in the production of the polyester resin (H3) having an acidic functional group is an aromatic tetracarboxylic acid anhydride from the viewpoint of low viscosity of the positive electrode material mixture paste for a lithium secondary battery, Is an anhydride of tetracarboxylic acid having two or more aromatic rings (especially 2 to 4).

<H> / <N> of the number of moles of the anhydride of the tetracarboxylic anhydride <N> to the number of moles of the hydroxyl group of the polyester having hydroxyl groups at one end <H> Is preferably 0.5 &lt; H / N &lt; 1.2, more preferably 0.7 &lt; H / N &lt; 1.1 and most preferably &lt; H / N &gt; = 1. <H> / <N><1, the remaining acid anhydride may be hydrolyzed with a necessary amount of water.

A catalyst may be used for the second step. Examples of the catalyst include tertiary amine compounds such as triethylamine, triethylenediamine, N, N-dimethylbenzylamine, N-methylmorpholine and 1,8-diazabicyclo [5.4.0] Undecene, 1,5-diazabicyclo- [4.3.0] -5-nonene, and the like.

Both the first step and the second step may be carried out without a solvent or a suitable dehydrating organic solvent may be used. The solvent used in the reaction may be removed by an operation such as distillation after completion of the reaction, or may be used as a part of the product as it is.

The reaction temperature is 80 占 폚 to 180 占 폚, preferably 90 占 폚 to 160 占 폚. When the reaction temperature is lower than 80 ° C, the reaction rate is slow. When the reaction temperature is higher than 180 ° C, the half esterified product forms a cyclic anhydride again, making it difficult to terminate the reaction.

In the general formula (1), n is preferably an integer of 1 to 30, more preferably an integer of 2 to 20. In the general formula (1), when at least one of n and t is 2 or more, the plurality of R ²³ 's present in the general formula (1) may all be the same group or a plurality of groups.

The resin having an acidic functional group is not limited to the above three types of (H1) to (H3) but may be a resin other than the three types of polyvinyl, polyurethane, polyester, polyether, These composite polymers may also be used. Two or more kinds of resins having these acidic functional groups may be used in combination.

[Other resins having commercially available acidic functional groups]

The commercially available resin having an acidic functional group is not particularly limited, and examples thereof include the following. These may be used alone or in combination.

As resins having an acidic functional group manufactured by BYK Chemie, anti-Terra-U, U100, 203, 204, 205, Disperbyk-101, 102, 106, 107, 110, 111, 140, 142, 170, 171, 174, 180 , 2001, BYK-P104, P104S, P105, 9076 and 220S.

Resins having an acidic functional group made by The Lubrizol Corporation of Japan include SOLSPERSE 3000, 21000, 26000, 36000, 36600, 41000, 41090, 43000, 44000 and 53095.

Examples of the resin having an acidic functional group of Efka Additives include EFKA 4510, 4530, 5010, 5044, 5244, 5054, 5055, 5063, 5064, 5065, 5066, 5070 and 5071.

Ajisper PN411 and Ajisper PA111 are examples of resins having an acidic functional group manufactured by Ajinomoto Fine-Techno Co.,

Resins having an acidic functional group manufactured by ELEMENTIS include Nuosperse FX-504, 600, 605, FA620, 2008, FA-196 and FA-601.

Police A-550 and Polity PS-1900 are examples of resins having an acidic functional group manufactured by Lion Corporation.

The resin having an acidic functional group made by Kusumoto Chemicals, Ltd. was Disarlon 2150, KS-860, KS-873SN, 1831, 1860, PW-36, DA-1200, DA-703-50, DA- , DA-375 and DA-234, and the like.

Resins having an acidic functional group made by BASF Japan include JONCRYL 67, 678, 586, 611, 680, 682, 683, 690, 52J, 57J, 60J, 61J, 62J, 63J, 70J, HPD-96J, 501J, 6610, PDX-6102B, 7100, 390, 711, 511, 7001, 741, 450, 840, 74J, HRC-1645J, 734, 852, 7600, 775, 537J, 1535, PDX-7630, 352J, 252D, 538J7640, 7641, 631, 790, 780 and 7610, and the like.

Examples of the resin having an acidic functional group made by Mitsubishi Rayon Co., Ltd. include Dianal BR-60, 64, 73, 77, 79, 83, 87, 88, 90, 93, 102, 106, 113 and 116 have.

The positive electrode active material constituting the positive electrode material mixture paste for a lithium secondary battery according to the present invention and the organic compound having a basic functional group and the organic functional compound having an acidic functional group which function as a binder have been described above. However, the positive electrode material mixture paste according to the present invention may contain various components known in the art such as a conductive additive, a binder, and a solvent as needed in order to further improve the electrode characteristics. Representative components are described below.

(Carbon material as conductive additive)

The positive electrode material mixture paste according to the present invention may contain a conductive auxiliary agent. The conductive auxiliary agent is not particularly limited and may be appropriately selected from known compounds, and a carbon material is most preferable. The carbon material is not particularly limited as long as it is a carbon material having conductivity. For example, graphite, carbon black, carbon nanotubes, carbon nanofibers, carbon fibers and fullerene may be used alone or in combination of two or more. It is preferable to use carbon black in terms of conductivity, easiness of access and cost.

Examples of the carbon black include furnace black which is produced by continuously pyrolyzing a gas or a liquid raw material in a reactor, ketjen black which is produced from ethylene heavy oil as a raw material, Channel black deposited by quenching on the bottom surface of the channel steel, thermal black obtained by periodically repeating combustion and pyrolysis using gas as a raw material, and acetylene black mainly using acetylene gas as raw materials, Can be used together. Carbon black, hollow carbon, or the like, which has been subjected to a conventionally-used oxidation treatment as described later, may also be used.

The oxidation treatment of carbon is carried out by treating the carbon with a high temperature in the air or by a secondary treatment with nitric acid, nitrogen dioxide, ozone or the like. Specific examples thereof include a process of directly introducing (covalent bonding) an oxygen-containing polar functional group such as a phenol group, a quinone group, a carboxyl group or a carbonyl group directly to the surface of carbon, and is a treatment method generally practiced to improve the dispersibility of carbon . In general, however, since the conductivity of carbon decreases as the amount of introduced functional groups increases, it is preferable to use carbon that is not subjected to oxidation treatment.

The larger the specific surface area of the carbon black to be used, the more the contact point between the carbon black particles increases, which is advantageous for lowering the internal resistance of the electrode. Specifically, it is preferably 20 m2 / g or more and 1,500 m2 / g or less, preferably 50 m2 / g or more and 1,500 m2 / g or less, more preferably 100 m2 / g or less as the specific surface area (BET) / g or more and 1500 m &lt; 2 &gt; / g or less is preferably used. When carbon black having a specific surface area of less than 20 m &lt; 2 &gt; / g is used, it may be difficult to obtain sufficient conductivity. Carbon black of more than 1500 m &lt; 2 &gt; / g may be difficult to obtain commercially available materials.

The particle diameter of the carbon black to be used is preferably 0.005 to 1 占 퐉, more preferably 0.01 to 0.2 占 퐉 in terms of primary particle diameter. Note that the primary particle diameter referred to herein is a value obtained by averaging the particle diameters measured by an electron microscope or the like.

Commercially available carbon blacks include, for example,

Manufactured by Tokai Carbon Co., Ltd. such as Tokablack # 4300, # 4400, # 4500, and # 5500;

Printex L and the like;

Furnace black made by Columbian Chemicals Co., such as Raven 7000, 5750, 5250, 5000 ULTRA III, 5000 ULTRA, Conductex SC ULTRA, 975 ULTRA, PUER BLACK 100, 115 and 205;

Furnace black made by Mitsubishi Chemical Corporation such as # 2350, # 2400B, # 2600B, # 30050B, # 3030B, # 3230B, # 3350B, # 3400B and # 5400B;

MONARCH 1400, 1300, 900, Vulcan XC-72R and BlackPearls 2000;

Furnace black, such as Ensaco 250G, Ensaco 260G, Ensaco 350G and SuperP-Li;

Ketjen black manufactured by Akzo Nobel, such as ketjen black EC-300J and EC-600JD;

Denke black, denka black HS-100, and Denki Kagaku Kogyo Kabushiki Kaisha acetylene black such as FX-35, but are not limited thereto.

(solvent)

The positive electrode material mixture paste according to the present invention may contain a solvent. Examples of usable solvents include alcohols, glycols, cellosolves, amino alcohols, amines, ketones, carboxylic acid amides, phosphoric acid amides, sulfoxides, carboxylic acid esters, phosphoric acid esters, ethers Nitriles, and water.

It is preferable to use a solvent having a high polarity in order to obtain solubility of the binder resin component and dispersion stability of the carbon material as the conductive additive.

Amide solvents in which various nitrogen such as N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide and N, Methylpyrrolidone, hexamethylphosphoric triamide, dimethylsulfoxide, and the like, but are not limited thereto. Two or more species may be used in combination.

(bookbinder)

The positive electrode material mixture paste according to the present invention may further contain a binder component. Here, the &quot; binder component &quot; is distinguished from an organic compound having a basic functional group or an acidic functional group described above as a dispersant, particularly a resin having a basic functional group or an acidic functional group. That is, the binder component is intended to be a compound different from the dispersant described above.

The binder to be used is, for example, an acrylic resin, a polyurethane resin, a polyester resin, a phenol resin, an epoxy resin, a phenoxy resin, a urea resin, a melamine resin, an alkyd resin, an acrylic resin, a formaldehyde resin, , Cellulose resins such as carboxymethyl cellulose, synthetic rubbers such as styrene-butadiene rubber and fluorine rubber, and conductive resins such as polyaniline and polyacetylene. They may also be modified bodies, mixtures or copolymers of these resins.

Specific examples of the solvent include ethylene, propylene, vinyl chloride, vinyl alcohol, vinyl alcohol, maleic acid, acrylic acid, acrylic ester, methacrylic acid, methacrylic acid ester, acrylonitrile, styrene, vinyl butyral, And the like as a structural unit.

Particularly, it is preferable to use a polymer compound having a fluorine atom in the molecule in terms of resistance, for example, polyvinylidene fluoride, polyvinyl fluoride and polytetrafluoroethylene.

The weight average molecular weight of the resin used as the binder is preferably 10,000 to 1,000,000. If the molecular weight of the resin used is small, the resistance of the binder tends to decrease. On the other hand, when the molecular weight is increased, the resistance of the binder is improved, but the viscosity of the binder itself is increased, and not only the workability is lowered but also the cohesive component tends to coagulate remarkably by acting as a coagulant.

&Lt; Positive electrode composite paste for lithium secondary battery >

The positive electrode material mixture paste of the present invention can be suitably used as a positive electrode material for a lithium secondary battery. When the positive electrode material mixture paste is used as the positive electrode material, in one embodiment, the paste contains at least one dispersing agent and a solvent selected from the group consisting of a positive electrode active material, a compound having a basic functional group and an organic compound having an acidic functional group, It is preferable to contain a material and a binder component.

The ratio of the total solid content of the positive electrode material mixture paste to the positive electrode active material is preferably 80 wt% or more and 98.5 wt% or less, preferably 83 wt% or more and 95 wt% or less. If the ratio of the positive electrode active material is less than 80% by weight, it may be difficult to obtain sufficient conductivity and discharge capacity. On the other hand, when the amount exceeds 98.5% by weight, the proportion of the binder component decreases, so that the adhesion to the current collector is lowered and the positive electrode active material may easily be desorbed.

The proportion of the solid content of the carbon material as the conductive additive in the total solid content in the positive electrode material mixture paste is preferably 0.5 wt% or more and 19 wt% or less, preferably 1.0 wt% or more and 15 wt% or less . If the proportion of the carbon material as the conductive additive is less than 0.5% by weight, it may be difficult to obtain sufficient conductivity. On the other hand, when the content exceeds 19% by weight, the ratio of the positive electrode active material greatly affecting the battery performance is lowered, and thus the discharge capacity may decrease.

The proportion of the binder component (resin component other than the resin having a basic functional group or the acidic functional group) in the total solid content in the positive electrode material mixture paste is preferably 1% by weight or more and 10% by weight or less, more preferably 2% It is preferable to use it at 8 wt% or less. If the proportion of the binder component is less than 1% by weight, the binding property is deteriorated. Therefore, the positive electrode active material and the carbon material as the conductive auxiliary agent tend to desorb in the electrode current collector. When the content exceeds 10% by weight, the positive electrode active material and the conductive auxiliary agent The ratio of the carbon material is lowered, leading to deterioration of the battery performance.

The optimum viscosity of the positive electrode material mixture paste depends on the coating method of the positive electrode material mixture paste, but it is generally preferably 100 mPa · s or more and 30,000 mPa · s or less.

The positive electrode material mixture paste of the present invention not only has excellent dispersibility of the positive electrode active material but also has an effect of alleviating aggregation of the positive electrode active material. The energy for mixing and dispersing the positive electrode active material and the carbon material as the conductive additive in the solvent is efficiently transferred to the carbon material (conductive auxiliary agent) without being inhibited by the agglomerates of the positive electrode active material, It is considered that it becomes possible to improve the dispersibility of the material (conductive auxiliary agent).

According to the positive electrode material mixture paste of the present invention, carbon material particles serving as a conductive additive can be uniformly arranged and adhered to the periphery of the positive electrode active material, and excellent conductivity and adhesion can be imparted to the positive electrode material mixture layer. Further, since the amount of the carbon material used as the conductive additive can be reduced by improving the conductivity, the amount of the positive electrode active material can be increased relatively, and the capacity, which is a large characteristic of the battery, can be increased.

Further, according to the positive electrode material mixture paste of the present invention, since the aggregation of the positive electrode active material and the carbon material (conductive auxiliary agent) is small, a uniform coating film having high smoothness can be obtained when applied to the current collector and the adhesion between the electrode collector and the positive electrode material mixture . Further, a specific organic compound having an acidic functional group and / or a basic functional group used as a dispersant acts on the surface of the carbon material (conductive auxiliary agent) to adsorb the surface of the positive electrode active material such as lithium transition metal composite oxide, Conductive agent) surface becomes stronger, so that the adhesion between the positive electrode active material and the carbon material (conductive auxiliary agent) can be improved as compared with the case where the specific organic compound is not used.

&Lt; Method of producing positive electrode material mixture paste for lithium secondary battery of the present invention &

Next, a method for producing the positive electrode material mixture paste according to the present invention will be described.

The positive electrode material mixture paste of the present invention may be prepared by dispersing, for example, at least one dispersing agent selected from the group consisting of an organic compound having a basic functional group and an organic compound having an acid functional group and a positive electrode active material in a solvent, Carbon material or a binder component. The order of addition of each component is not particularly limited. If necessary, a solvent may be added as a constituent component of the positive electrode material mixture paste.

An embodiment using an acidic compound such as an inorganic acid, an organic acid having a molecular weight of not more than 300 or a resin having an acidic functional group, or a resin having a basic functional group in combination, when the various derivatives having a basic functional group and the positive electrode active material are dispersed in a solvent Is more preferable because the dispersibility of the paste is further improved. In addition, when the vinylamide resin and the positive electrode active material are dispersed in a solvent, embodiments in which various derivatives having a basic or acidic functional group are used together are preferable because the dispersibility of the paste is further improved.

In one embodiment of the method for producing the paste, at least one dispersant selected from the group consisting of an organic compound having a basic functional group and an organic compound having an acidic functional group is completely or partially dissolved in a solvent to add a positive electrode active material , It is preferable that the compound is dispersed in a solvent while the compound acts on the positive electrode active material (for example, adsorption).

In another embodiment of the method for producing the paste, an acidic compound or a resin having a basic functional group selected from the group consisting of various derivatives having a basic functional group and inorganic acid, an organic acid having a molecular weight of 300 or less and an acidic functional group, It is preferable that the derivative and the resin having an acidic compound or a basic functional group are dispersed in a solvent while acting (for example, adsorbing) the positive active material on the positive electrode active material by adding or mixing the positive electrode active material in the solution.

In another embodiment of the method for producing a paste, a vinylamide resin and various derivatives having a basic functional group or an acidic functional group are completely or partially dissolved in a solvent, a positive active material is added to the solution, It is preferable that the derivative is dispersed in a solvent while acting on the positive electrode active material (for example, adsorption).

The concentration of the positive electrode active material in the paste prepared from the dispersion is preferably set appropriately depending on the specific property value of the positive electrode active material such as the specific surface area of the positive electrode active material to be used and the amount of the surface functional group to be used. Although not particularly limited, the concentration of the positive electrode active material is preferably 1% by weight or more and 90% by weight or less, more preferably 10% by weight or more and 80% by weight or less, based on the total weight of the paste. If the concentration of the positive electrode active material is too low, the production efficiency is deteriorated, the viscosity of the compound paste tends to be lowered, the positive electrode active material tends to precipitate with time, and it may become difficult to produce a uniform positive electrode. On the other hand, if the concentration of the positive electrode active material is too high, the viscosity of the dispersion becomes remarkably high, and the dispersion efficiency and handling property of the dispersion body may be deteriorated.

The amount of the at least one organic compound selected from the group consisting of an organic compound having a basic functional group and an organic compound having an acid functional group to be used as a dispersant is determined by the specific surface area and the like of the positive electrode active material to be used. Generally, the amount of the organic compound used as the dispersing agent is preferably 0.01 to 30 parts by weight, preferably 0.05 to 25 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the positive electrode active material , And 20 parts by weight or less. If the addition amount is too small, a sufficient dispersion effect can not be obtained, and if it is added excessively, a remarkable improvement in dispersion tends not to be obtained.

Further, in dispersing the positive electrode active material in a solvent, it is preferable to add an acidic compound containing a variety of derivatives having a basic functional group and an inorganic acid, an organic acid having a molecular weight of 300 or less or a resin having an acidic functional group, or a resin having a basic functional group. The amount of the acidic compound or the resin having a basic functional group to be added when dispersing the positive electrode active material is 0.01 to 30 parts by weight, preferably 0.05 to 25 parts by weight, based on 100 parts by weight of the positive electrode active material More preferably 0.1 part by weight or more and 20 parts by weight or less.

Further, in dispersing the positive electrode active material in a solvent, it is preferable to add various derivatives having a vinylamide resin and a basic functional group or an acidic functional group. The amount of the basic functional group or various derivatives having an acidic functional group to be added when the positive active material is dispersed is 0.01 to 30 parts by weight, preferably 0.05 to 25 parts by weight, based on 100 parts by weight of the positive electrode active material More preferably 0.1 part by weight or more and 20 parts by weight or less.

Further, there is a device (hereinafter, referred to as &quot; device &quot;) used for dispersing one or more organic compounds selected from the group consisting of an organic compound having a basic functional group and an organic compound having an acidic functional group A dispersing device commonly used in pigment dispersion and the like can be applied.

For example, a dispersing machine as shown below.

Mixers such as a disper, a homo mixer or a planetary mixer;

Homogeneous airflow such as "KUREAMIX" manufactured by M TECHNIQUE Co., Ltd. or "FILMICS" manufactured by PRIMIX Co., Ltd.;

Such as a paint conditioner (manufactured by Red Devil), a ball mill, sand mill ("DAINO mill" manufactured by Shinmaru Enterprises Corporation), attritor, pearl mill ("DCP mill" manufactured by EIRICH CO. Type disperser;

("GENUS PY" manufactured by GENUS Corporation, "Star Burst" manufactured by SUGINO MACHINE LIMITED, "Nanomizer" manufactured by NANOMIZER Inc.), "Kuea SS-5" manufactured by M TECHNIQUE Co., Ltd., &Quot; MICROS &quot; and the like; or

Others include Rollil.

It is more preferable that the dispersing machine is provided with a treatment for preventing the metal from being mixed with the dispersing machine.

For example, in the case of using a medium type dispersing machine, it is preferable to use a ceramic or resin dispersing machine for the stirrer and vessel, or a dispersing machine for metal stirring machine and vessel surface treated with tungsten carbide spraying or resin coating . As the medium, it is preferable to use ceramic beads such as glass beads or zirconia beads or alumina beads. It is also preferable to use a ceramic roll even in the case of using a roll mill. Only one kind of dispersing device may be used, or plural kinds of devices may be used in combination.

In the case of using a positive electrode active material which is broken or fragile due to a strong impact, a non-medium type dispersing device such as a roll mill or a homogenizer is preferable to a medium type dispersing device.

In order to improve the wettability of the positive electrode active material to the solvent and to further improve the dispersibility in the solvent, the surface is previously treated with at least one dispersing agent selected from the group consisting of an organic compound having a basic functional group or an acidic functional group and a vinylamide resin One positive electrode active material can be used.

As the treatment method, a roll mill such as two rolls or three rolls as a dry processor, a high-speed stirrer such as a Henkel mixer or a super mixer, a fluid energy crusher such as a microneizer or a jet mill, and an aerator may be used. On the other hand, a kneader can be used as a wet processor. However, the processing method is not limited to the above method. Depending on the kind of the positive electrode active material, the positive electrode active material itself may be broken during the treatment to deteriorate the battery performance. Therefore, it is preferable to select a treatment method suitable for the positive electrode active material. In the case of using a dry processor, the treatment agent may be directly added as it is. However, in order to more uniformly treat the surface of the positive electrode active material, the treatment agent is previously dissolved and dispersed in a small amount of solvent, Method is preferable. In addition, it may be heated according to need to increase the treatment efficiency.

A method of adding a component other than the dispersant such as a binder component, that is, a resin having a basic functional group or an acidic functional group, is preferably a method of adding at least one component selected from the group consisting of an organic compound having a basic functional group and an organic compound having an acidic functional group A method of adding and dissolving the binder component in a solid state while stirring a dispersion obtained by dispersing a species of organic compound and a positive electrode active material in a solvent. Further, a method in which a binder component is dissolved in a solvent is prepared in advance and mixed with the dispersion. Further, after the binder component is added to the dispersion, the dispersion treatment may be carried out again with the dispersion apparatus.

As a method of adding the carbon material used as the conductive auxiliary agent, for example, at least one organic compound selected from the group consisting of an organic compound having a basic functional group and an organic compound having an acidic functional group used as the dispersing agent and a positive electrode active material are dispersed in a solvent And then adding and dispersing the carbon material to be used as a conductive additive to the dispersion obtained by further stirring. Alternatively, a dispersion in which a carbon material used as a conductive auxiliary agent is dispersed in a solvent may be added to the dispersion of the positive electrode active material and mixed. Here, it is more preferable to add various derivatives having a basic functional group and a resin having an acidic compound (an inorganic acid, an organic acid having a molecular weight of 300 or less, an acidic functional group, etc.) or a basic functional group at the time of dispersing the positive electrode active material in a solvent . When the vinylamide resin and the positive electrode active material are dispersed in a solvent, it is more preferable to add various derivatives having a basic functional group or an acidic functional group together.

Further, when at least one compound selected from the group consisting of an organic compound having a basic functional group and an organic compound having an acidic functional group and a positive electrode active material used as a dispersant are dispersed in a solvent, a part or all of the carbon material used as the conductive additive May be added at the same time to perform a covariance process. When various derivatives having a basic functional group are added in this manner, an acidic compound or a resin having a basic functional group selected from the group consisting of inorganic acids, organic acids having a molecular weight of 300 or less and acidic functional groups It is more preferable to add them together. When a vinylamide resin is added, it is more preferable to add various derivatives having a basic functional group or an acidic functional group at the time of covalent treatment.

The dispersion particle diameter of the positive electrode active material varies depending on the size of the primary particle diameter of the positive electrode active material used. But is not particularly limited, but it is preferable to be finer in a typical range of 0.05 to 100 m, preferably 0.1 to 70 m, more preferably 0.15 to 50 m. The positive electrode material mixture paste having a dispersion particle diameter of the positive electrode active material of less than 0.05 mu m may be difficult to prepare itself. Further, when a paste having a dispersed particle diameter of the positive electrode active material of more than 100 mu m is used as the electrode material, there arises a problem that the resistance distribution of the electrode is uneven and the addition amount of the conductive additive is increased for lowering resistance . The &quot; dispersed particle size &quot; described in this specification is a value determined by a determination by a particle size meter (in accordance with JIS K5600-2-5). When the dispersion particle size is 1.0 占 퐉 or less, the particle size distribution is 50% (D50) when the volume ratio of the particles is smaller than that of the particle size distribution in the volume particle size distribution. And a particle size distribution meter ("Microtrac UPA" manufactured by Nikkiso Co., Ltd.).

As described above, the positive electrode material mixture paste of the present invention is usually manufactured and distributed by using a dispersion (liquid) or paste containing a solvent. Generally, even if one or more dispersants selected from the group consisting of a conductive auxiliary agent, an organic compound having an organic functional group and an organic compound having an acidic functional group are mixed in the state of dry powder, the dispersant can be uniformly applied to the positive electrode active material or the conductive auxiliary agent It is difficult to give. Therefore, it is preferable to uniformly disperse the positive electrode active material and the conductive auxiliary agent in the positive electrode active material or the conductive auxiliary agent by dispersing the positive active material or the conductive auxiliary agent in the solvent by the liquid phase method. In addition, the use of a solvent as described below is preferable from the viewpoint that it is preferable to apply the liquid dispersion to the electrode mixture layer as uniformly as possible and to dry it.

However, for example, it is also conceivable that the dispersion prepared by the liquid phase method is once dried to remove the solvent for reasons such as transportation costs. It is also conceivable that the dry powder is re-dispersed in an appropriate solvent and used at the time of forming the electrode mix layer. Therefore, the positive electrode material mixture paste of the present invention is not limited to a liquid dispersion and may be a composition in the form of dry powder as described above.

<Lithium secondary battery>

The lithium secondary battery according to the present invention comprises a positive electrode having a positive mixture layer on a first current collector, a negative electrode having a negative mixture layer on the second current collector, lithium interposed between the positive mixture layer and the negative- And the positive electrode material mixture layer is formed using the positive electrode material mixture paste for a lithium secondary battery according to the present invention. The lithium secondary battery according to the present invention may have a positive electrode material mixture layer formed by using the positive electrode material mixture paste for a lithium secondary battery according to the present invention, and the other constituent members and materials thereof are not particularly limited, and a technique well known in the art Can be applied.

1 is a schematic cross-sectional view showing one embodiment of a lithium secondary battery according to the present invention. 1, in a lithium secondary battery, a positive electrode 34 having a positive electrode mixture layer 32 on a first current collector 30 and a positive electrode 34 having a positive electrode mixture layer 32 in a cell 20 housing the electrolyte 10 The negative electrode 44 having the negative electrode material mixture layer 42 is arranged so that the positive electrode material mixture layer 32 and the negative electrode material mixture layer 42 are opposed to each other. The lithium ion moves through the electrolyte solution 10 between the positive electrode material mixture layer 32 and the negative electrode material mixture layer 42, thereby enabling conduction. Further, a separator 50 may be disposed between the positive electrode material mixture layer 32 and the negative electrode material mixture layer 42 to improve safety. In addition, the positive electrode and the negative electrode may have a foundation layer (not shown) for enhancing the adhesion between the current collector and each of the mixture layers.

The material and shape of the collector used in each electrode are not particularly limited. As the material, for example, metals or alloys such as aluminum, copper, nickel, titanium or stainless steel can be used. In particular, aluminum is preferable as the positive electrode material. Further, copper is preferable as the negative electrode material. As the shape of the current collector, a metal foil in a flat plate shape is generally used, but a roughened surface, a thin foil with a hole, and a mesh-like material can also be used.

An example of a method of forming an electrode ground layer on a current collector is a method of applying an electrode ground paste in which a carbon black and a binder component are dispersed as a conductive material to a collector of electrode and drying the electrode current collector. The film thickness of the electrode base layer is not particularly limited as long as the conductivity and adhesion can be maintained. Generally, it is not less than 0.05 mu m and not more than 20 mu m, preferably not less than 0.1 mu m and not more than 10 mu m.

As an example of the method of forming the electrode mixture layer on the current collector, there is a method of directly coating the electrode mixture paste on the current collector and drying and a method of applying electrode paste paste after drying the electrode mixture layer on the current collector and drying . In the case of forming the electrode mixture layer on the electrode bottom layer, the electrode paste paste may be applied on the current collector, and then the electrode mixture paste may be superimposed on the electrode mixture paste in a wet state, followed by coating and drying. The thickness of the electrode mixture layer is generally 1 占 퐉 or more and 500 占 퐉 or less, preferably 10 占 퐉 or more and 300 占 퐉 or less.

As the material of the positive electrode material mixture layer, the positive electrode material mixture paste according to the present invention is used. On the other hand, the material of the negative electrode material mixture layer is not particularly limited and materials well known in the art can be appropriately selected and used. For example, a mixture containing a negative electrode active material, a conductive auxiliary agent, and a binder component may be used.

The coating method for forming the base layer and the positive electrode or negative electrode mixture layer is not particularly limited and a known method can be applied. Specific examples thereof include die coating, dip coating, roll coating, doctor coating, spray coating, gravure coating, screen printing or electrostatic coating. After the application, a rolling process using a flat plate press, calender roll, or the like may be performed.

As the electrolyte constituting the lithium secondary battery according to the present invention, an electrolyte containing lithium is dissolved in a non-aqueous solvent. Electrolyte is not particularly limited _{to, LiBF 4, LiClO 4, LiPF} 6, LiAsF 6, LiSbF 6, LiCF 3 SO 3, Li (CF 3 SO 2) 2 N, LiC 4 F 9 SO 3, Li (CF 3 SO ₂ ) ₃ C, LiI, LiBr, LiCl, LiAlCl, LiHF ₂ , LiSCN or LiBPh ₄ .

The nonaqueous solvent is not particularly limited, and for example,

Carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate;

lactones such as? -butyrolactone,? -valerolactone and? -octanoic lactone;

1,2-ethoxyethane, 1,2-ethoxyethane and 1,2-dibutyl ether, such as tetrahydrofuran, 2-methyltetrahydrofuran, Glycols such as ethoxyethane;

Esters such as methyl formate, methyl acetate and methyl propionate;

Sulfoxides such as dimethyl sulfoxide and sulfolane; and

And nitriles such as acetonitrile. These solvents may be used alone or in combination of two or more.

In addition, a gel electrolyte in which the electrolytic solution is held in a polymer matrix may be used. Although not particularly limited, examples of the polymer matrix include an acrylate monomer having a polyalkylene oxide segment, a polyphosphazene monomer having a polyalkylene oxide segment, and a polysiloxane having a polyalkylene oxide segment.

Although the structure and materials of the lithium secondary battery according to the present invention have been described with reference to Fig. 1, the constituent members and materials thereof other than the positive electrode material mixture paste of the present invention are not particularly limited. Generally, the lithium secondary battery includes a positive electrode, a negative electrode, an electrolyte, and a separator, and can be formed into various shapes such as a paper type, a cylindrical type, a button type, and a laminate type, depending on the purpose of use.

Example

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the following examples. In the following description, terms are used based on the following definitions.

In the following Examples, "parts" and "%" are parts by weight.

With regard to the dispersing agent, the term "an organic dye derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, and a triazine derivative having a basic functional group" Is hereinafter referred to as &quot; a derivative having a basic functional group &quot;.

With respect to the dispersant, the description of the "organic dye derivative having an acidic functional group and at least one derivative selected from the group consisting of triazine derivatives having an acidic functional group" is hereinafter referred to as "a derivative having an acidic functional group".

With respect to the dispersant, the description of "various derivatives having a basic functional group" or "various derivatives having an acid functional group" is hereinafter referred to as "a derivative having a basic functional group or an acidic functional group".

About the "viscosity" of the positive electrode active material dispersion, a value measured at 25 ° C. at a rotation speed of 50 rpm using an E-type viscometer ("RE80 type viscometer" manufactured by TOKI SANGYO CO., LTD. .

The "dispersion particle size" of the positive electrode active material dispersion and electrode mixture paste is determined by a determination by a particle size analyzer (in accordance with JIS K 5600-2-5).

The &quot; polymerization average molecular weight (Mw) &quot; of a resin having an acidic functional group is intended to be a value obtained by performing measurement using HLC-8320GPC (manufactured by TOSOH CORPORATION) as an apparatus and converting the measured values to polystyrene. A value obtained by measurement by a typical oxidation titration method is also intended for the acid value.

The polymerized average molecular weight (Mw) of the resin having a basic functional group was measured by using HLC-8320GPC (manufactured by TOSOH CORPORATION) as a device and using SUPER-AW3000 as a column and using 30mM triethylamine and 10mM LiBr N , N-dimethylformamide solution, and the value obtained by converting the measured value into polystyrene is intended.

Also, the value of the amine is intended to be the value of the total amine value (mg KOH / g) measured in accordance with the method of ASTM D 2074.

In the following Examples and Comparative Examples, the positive electrode active material, the dispersant, that is, the compound having a basic functional group (a derivative having a basic functional group, the resin having a basic functional group) and the compound having an acidic functional group (a derivative having an acidic functional group , A resin having an acidic functional group) are shown below. The binder resin, the carbon black for the conductive auxiliary, and the carbon black dispersion for the conductive auxiliary, which are used in accordance with necessity, are also shown below.

&Lt; Positive electrode active material &

· Lithium cobaltate LiCoO ₂ HLC-17 (trade name, available from The Honjo Chemical Corporation): average primary particle diameter 2.5 占 퐉, specific surface area 0.54 m2 / g.

- Lithium manganate LiMn ₂ O ₄ CELLSEEDS-LM (trade name, manufactured by Nippon Chemical Industrial Co., Ltd.): average primary particle diameter 12.0 占 퐉, specific surface area 0.48 m 2 / g.

Lithium nickel oxide LiNiO ₂ (manufactured by The Honjo Chemical Corporation): average primary particle diameter 9.0 탆, specific surface area 0.3 m 2 / g.

· Lithium iron phosphate LiFePO ₄ (manufactured by TIANJIN STL ENERGY TECHNOLOGY): average primary particle diameter 0.2 μm, specific surface area 15 m 2 / g.

<Dispersant>

<Compound Having Basic Functional Group: Derivative Having Basic Functional Group>

The symbols (A) to (O) shown in Tables 1 to 4 are more specifically classified as follows.

(A), (B), (C), (D), (E), and (H) having a basic functional group:

Anthraquinone derivatives having basic functional groups: (F), (L)

Acridone derivatives having basic functional groups: (G)

Triazine derivatives having basic functional groups: (H), (I), (J), (K), (L), (M)

&Lt; Compound having no basic functional group and no acidic functional group >

Symbols (P) and (Q) shown in Table 5 are used for comparison in the present invention.

<Compound Having Basic Functional Group: Resin Having Basic Functional Group>

· Resin polymer (G1) type with basic functional group

G1-1: a polyvinyl polymer having an amino group; The weight-average molecular weight is 13,500 and the amine value is 27.5 mgKOH / g.

G1-2: a polyvinyl polymer having an amino group; The weight-average molecular weight was 21600 and the amine value was 17.4 mgKOH / g.

G1-3: a polyvinyl polymer having an amino group; The weight-average molecular weight is 11900 and the amine value is 25.2 mgKOH / g.

The methods for preparing the above polymers (G1-1) to (G1-3) are as follows.

[Preparation of vinyl polymer polymer (G1-1) having an amino group]

&Lt; Synthesis of vinyl polymer (A1-1)

500 parts of methyl methacrylate, 28 parts of thioglycerol and 528 parts of N-methyl-2-pyrrolidone were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a gas introducing tube. The inside of the reaction vessel was heated to 90 캜, and 0.50 part of AIBN was added, followed by reaction for 7 hours. After confirming that 95% of the reaction was carried out by measuring the solid content, the solution was cooled to room temperature to obtain a 50% solid solution of the vinyl polymer (A1-1) having two free hydroxyl groups in one terminal region having a weight average molecular weight of 4200.

&Lt; Synthesis of polymer (G1-1) >

A reaction vessel equipped with a gas inlet tube, a thermometer, a condenser and a stirrer was charged with 1022 parts of a 50% solids solution of the vinyl polymer (A1-1), 45.2 parts of isophorone diisocyanate and 0.11 g of dibutyltin dilaurate as a catalyst And replaced with nitrogen gas. The inside of the reaction vessel was heated to 100 캜 and reacted for 3 hours. The reaction vessel was cooled to 40 캜 and added dropwise over 30 minutes in a mixture of iminopropyl propane (26.7 parts) and N-methyl-2-pyrrolidone (363.3 parts) After the reaction, the reaction was terminated by cooling to room temperature. The solid content was adjusted to 40% to obtain a pale yellow transparent solution of the polymer (G1-1). The polymer (G1-1) had a weight-average molecular weight of 13,500 and an amine value of 27.5 mgKOH / g.

[Preparation of vinyl polymer polymer (G1-2) having amino group]

&Lt; Synthesis of vinyl polymer (A1-2)

500 parts of n-butyl methacrylate, 28 parts of thioglycerol and 528 parts of N-methyl-2-pyrrolidone were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a gas introducing tube. The inside of the reaction vessel was heated to 90 캜, and 0.50 part of AIBN was added, followed by reaction for 7 hours. After confirming that 95% of the reaction was carried out by measuring the solid content, the solution was cooled to room temperature to obtain a 50% solid solution of a vinyl polymer (A1-2) having two free hydroxyl groups in one terminal region having a weight average molecular weight of 4800.

&Lt; Synthesis of polymer (G1-2)

1056 parts of a 50% solid solution of the vinyl polymer (A1-2), 115.1 parts of isophorone diisocyanate and 0.12 g of dibutyltin dilaurate as a catalyst were placed in a reaction vessel equipped with a thermometer, a condenser and a stirrer And replaced with nitrogen gas. The inside of the reaction vessel was heated to 100 캜 and reacted for 3 hours. After cooling to 40 캜, 25.5 parts of iminopropyl propane, 11.5 parts of 2-amino-2-methyl-propanol and 492.0 parts of N-methyl- The mixture was added dropwise over 30 minutes and further reacted for 1 hour, and then cooled to room temperature to terminate the reaction. The solid content was adjusted to 40% to obtain a pale yellow transparent solution of the polymer (G1-2). The polymer (G1-2) had a weight average molecular weight of 21600 and an amine value of 17.4 mgKOH / g.

[Preparation of vinyl polymer polymer (G1-3) having amino group]

&Lt; Synthesis of vinyl polymer (A1-3) >

400 parts of methyl methacrylate, 100 parts of butyl acrylate, 56 parts of thioglycerol and 556 parts of N-methyl-2-pyrrolidone were placed in a reaction vessel equipped with a thermometer, a condenser and a stirrer, did. The inside of the reaction vessel was heated to 90 캜, and 0.50 part of AIBN was added, followed by reaction for 7 hours. After confirming that 95% of the reaction was carried out by measuring the solid content, the solution was cooled to room temperature to obtain a 50% solid solution of the vinyl polymer (A1-3) having two free hydroxyl groups in one terminal region of the weight average molecular weight of 3000.

&Lt; Synthesis of Polymer (G1-3)

A reaction vessel equipped with a gas inlet tube, a thermometer, a condenser and a stirrer was charged with 1112 parts of a 50% solids solution of the vinyl polymer (A1-3), 230.2 parts of isophorone diisocyanate and 0.13 g of dibutyltin dilaurate as a catalyst And replaced with nitrogen gas. The inside of the reaction vessel was heated to 100 ° C. and reacted for 3 hours. The reaction vessel was cooled to 40 ° C., and a solution of 56.4 parts of methyliminobispropylamine, 33.4 parts of dibutylamine and 757.9 parts of N-methyl- And the reaction was further allowed to proceed for 1 hour, followed by cooling to room temperature to terminate the reaction. The solid content was adjusted to 40% to obtain a pale yellow transparent solution of the polymer (G1-3). The polymer (G1-3) had a weight average molecular weight of 11,900 and an amine value of 25.2 mgKOH / g.

· Resin polymer (G2) type with basic functional group

G2-1: a polyester polymer having an amino group; A weight average molecular weight of 13,000, and an amine value of 36 mgKOH / g.

G2-2: a polyester polymer having an amino group; A weight average molecular weight of 27,000, and an amine value of 41 mgKOH / g.

G2-3: a polyvinyl polymer having an amino group; Weight average molecular weight 15,200, amine value 94 mgKOH / g.

The methods for preparing the above polymers (G2-1) to (G2-3) are as follows.

[Preparation of polyester polymer (G2-1) having amino group]

<Synthesis of polyester (A2-1) having acryloyl group at one end>

20.8 parts of 4-hydroxybutyl acrylate and 379 parts of epsilon -caprolactone, 0.1 part of monobutyltin (IV) oxide as a catalyst, 0.1 part of hydrocarbons as a polymerization inhibitor, 0.1 part of quinone was added and the mixture was heated and stirred at 120 ° C for 4 hours under a stream of dry air to confirm that 95% of the solid was reacted. The reaction was terminated and 171 parts of N-methyl- And adjusted to a solid content of 70% by weight to obtain a 70% by weight solid solution of polyester (A2-1) having one acryloyl group at one end with a weight average molecular weight of 6500.

&Lt; Synthesis of polymer (G2-1) >

18.9 parts of iminopropyl propane and 248 parts of N-methyl-2-pyrrolidone were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a gas introducing tube, and the mixture was heated to 50 캜 to obtain a solid component 70 571 parts by weight of the solution was added dropwise over 30 minutes and further reacted for 1 hour. Then, a mixed solution of 16.0 parts of isophorone diisocyanate and 112 parts of N-methyl-2-pyrrolidone was added dropwise over 30 minutes, And N-methyl-2-pyrrolidone was added to adjust the solid content to 30% by weight to obtain a 30% by weight solid solution of the polymer (G2-1) having a weight average molecular weight of 13000 and an amine value of 36 mgKOH / g.

[Preparation of polyester polymer (G2-2) having amino group]

&Lt; Synthesis of polymer (G2-2)

23.9 parts of methyliminobispropylamine and 248 parts of N-methyl-2-pyrrolidone were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a gas introducing tube, and the mixture was heated to 50 占 폚 to obtain a solid 571 parts of a 70 wt% solution was added dropwise over 30 minutes, and after a further 1 hour reaction, a mixture of 18.3 parts of isophorone diisocyanate and 207 parts of N-methyl-2-pyrrolidone was added dropwise over 30 minutes, Hour reaction, and N-methyl-2-pyrrolidone was added to adjust the solid content to 30% by weight to obtain a 30% by weight solid solution of the polymer (G2-2) having a weight average molecular weight of 27,000 and an amine value of 41 mgKOH / g.

[Preparation of vinyl polymer (G2-3) having amino group]

<Synthesis of vinyl polymer (A2-2) having acryloyl group at one end>

400 parts of methyl methacrylate, 100 parts of butyl acrylate, and 100 parts of N-methyl-2-pyrrolidone were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a gas introducing tube. The inside of the reaction vessel was heated to 80 占 폚 and a solution of 0.5 part of 2,2'-azobisisobutyronitrile dissolved in 27.5 parts of 3-mercapto-1,2-propanediol was added and reacted for 10 hours. After confirming that 95% of the solid component was reacted, 427 parts of N-methyl-2-pyrrolidone was added and diluted. Then, 32.6 parts of acryloyloxyethyl isocyanate, 1 part of DBTDL and 0.3 part of methylhydroquinone And the mixture was further heated and stirred for 2 hours. Further, the solid content was adjusted to 50% by weight to obtain a 50% by weight solid solution of the vinyl polymer (A2-2) having two acryloyl groups at one terminal having a weight average molecular weight of 4500.

&Lt; Synthesis of polymer (G2-3) >

27.8 parts of iminopropyl propane and 184 parts of N-methyl-2-pyrrolidone were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a gas introducing tube, and heated to 50 占 폚 to obtain a solid component 70 Was added dropwise over 30 minutes, and after further reaction for 1 hour, a mixture of 15.7 parts of isophorone diisocyanate and 121 parts of N-methyl-2-pyrrolidone was added dropwise over 30 minutes, N-methyl-2-pyrrolidone was added to adjust the solid content to 30% by weight to obtain a 30% by weight solid solution of the polymer (G2-3) having a weight average molecular weight of 15,200 and an amine value of 94 mgKOH / g.

(Y) having a basic functional group other than the polymer (G1) and (G2)

(Y1): Ajisper PB821, manufactured by Ajinomoto Fine-Techno Co., Inc., resin having an amino group

(Y2): SOLSPERSE24000GR, manufactured by The Lubrizol Corporation, Japan, resin having an amino group

· Vinyl amide resin

(1) PVP K-30 (trade name, manufactured by ISP JAPAN): polyvinylpyrrolidone (represented by PVP), weight average molecular weight of about 4-80,000.

(2) AGRIMER AL-10LC (product of ISP JAPAN): alkylated polyvinylpyrrolidone / 1-butene = 90/10 (referred to as AGRIMER)

(3) PNVA GE191 (trade name, manufactured by Showa Denko KK): poly N-vinylacetamide (referred to as PNVA) weight average molecular weight of about 1 to 30,000.

&Lt; Compound having an acidic functional group: Derivative having an acidic functional group >

(Da) to (Ds) shown in Tables 6 to 10, and are more specifically classified as follows.

(Da), (Dk), (Dl), (Dm), (Dn), (Do), (Dp), (Dq), (Dr) and (Ds) having an acidic functional group.

Diazinic acid derivatives having acidic functional groups: (Da), (Db), (Dc), (Dd), (De), (Df), (Dg) Dp), (Dr)

A derivative having an acidic functional group Dm: At the time of preparing the dispersion of the positive electrode active material, 1 equivalent of ammonia was added to a sulfonic acid body (no salt formation) to prepare ammonium salt solution.

Ds: A dispersion of the positive electrode active material was prepared by adding 1 equivalent of ammonia to a sulfonic acid body (no salt formation) to prepare an ammonium salt solution.

<Acid compound: inorganic acid, organic acid having molecular weight of 300 or less>

With respect to the inorganic acid and the organic acid having a molecular weight of 300 or less, the compounds shown in Table 11 described later were added according to the composition shown in Table 11.

&Lt; Acid compound: resin having an acidic functional group >

· Polyvinylidene fluoride resin (H1) type with acidic functional group

Polyvinylidene fluoride having a (H1-1) sulfonic acid group: a weight average molecular weight of about 10,000.

(H1-2) polyvinylidene fluoride resin containing phosphoric acid group: weight average molecular weight of about 10,000.

(H1-3) KF polymer W # 9100 (made by KUREHA CORPORATION): polyvinylidene fluoride resin having carboxyl group, weight average molecular weight about 280,000.

The methods for preparing the resins (H1-1) and (H1-2) are shown below.

<Preparation of polyvinylidene fluoride resin (H1-1) having sulfonic acid group>

The preparation of a polyvinylidene fluoride resin having a sulfonic acid group is disclosed in Japanese Patent No. 3784494. That is, 100 g of polyvinylidene fluoride resin having various molecular weights was dispersed in 400 mL of chloroform in a 1 L separable flask, 100 mL of chlorosulfonic acid was added dropwise while stirring, and the mixture was heated under reflux for 2 hours. Thereafter, the reaction solution was poured into ice water, the solid matter was filtered, washed with water and dried to obtain a sulfonic acid-modified polyvinylidene fluoride resin. As the polyvinylidene fluoride resin having a weight average molecular weight of about 10,000, a homopolymer of 1,1-difluoroethylene synthesized by a known method is used and a polyvinylidene fluoride resin having a weight average molecular weight of about 280,000 and about 1,000,000 Were respectively KF polymers W # 1100 and W # 7300 (homopolymers of 1,1-difluoroethylene, manufactured by KUREHA CORPORATION).

<Preparation of polyvinylidene fluoride resin (H1-2) having a phosphoric acid group>

First, a polyvinylidene fluoride resin having a hydroxyl group was synthesized as described below according to JP-A-6-172452. That is, 1040 g of ion-exchanged water, 0.8 g of methyl cellulose, 2.5 g of ethyl acetate, 4 g of diisopropyl peroxydicarbonate, 396 g of vinylidene fluoride and 4 g of 2-hydroxyethyl acrylate were added to a 2 L autoclave at 28 ° C for 45 hours Suspension polymerization is carried out. After completion of the polymerization, the polymer slurry was dehydrated, washed with water, and then dried at 80 DEG C for 20 hours to obtain a polymer. Then, 100 g of the hydroxyl group-containing polyvinylidene fluoride resin was dispersed in 400 mL of chloroform in a 1 L separable flask equipped with a nitrogen gas introducing tube and a condenser, and 100 g of polyphosphoric acid having an orthophosphoric acid content of 116% After mixing, the mixture was heated under reflux for 2 hours. Thereafter, the reaction solution was poured into iced water, and the solid matter was filtered, washed with water and dried to obtain a phosphoric acid-modified polyvinylidene fluoride resin (H1-2).

Polyvinylidene (H2) type having an acidic functional group < Preparation of a polyvinylidene oxide (H2-1) having a carboxyl group >

100 parts of n-butyl methacrylate and 100 parts of benzyl methacrylate were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a gas introducing tube, and replaced with nitrogen gas. The inside of the reaction vessel was heated to 80 占 폚 and a solution of 0.1 part of 2,2'-azobisisobutyronitrile dissolved in 12 parts of 3-mercapto-1,2-propanediol was added and reacted for 10 hours. It was confirmed that 95% of the solid contents were reacted. 19 parts of pyromellitic anhydride, 231 parts of N-methyl-2-pyrrolidone and 0.40 parts of 1,8-diazabicyclo- [5.4.0] -7-undecene as a catalyst were added and reacted at 120 ° C for 7 hours . As a result of measuring the acid value, it was confirmed that at least 98% of the acid anhydride was half-esterified, and the reaction was terminated to obtain a polyvinyl alcohol (H2-1) solution having a carboxyl group with a solid content of 50%. The polyvinyl alcohol (H2-1) had a weight average molecular weight (Mw) of 8,500 and an acid value of 43 mgKOH / g.

&Lt; Preparation of polyvinyl alcohol (H2-2) having carboxyl group >

A reaction vessel equipped with a gas inlet tube, a thermometer, a condenser and a stirrer was charged with 180 parts of methyl methacrylate and 20 parts of methacrylic acid, and the mixture was substituted with nitrogen gas. The inside of the reaction vessel was heated to 80 占 폚 and a solution of 0.1 part of 2,2'-azobisisobutyronitrile dissolved in 12 parts of 3-mercapto-1,2-propanediol was added and reacted for 10 hours. It was confirmed that 95% of the solid contents were reacted. 19 parts of pyromellitic anhydride, 231 parts of N-methyl-2-pyrrolidone and 0.40 parts of 1,8-diazabicyclo- [5.4.0] -7-undecene as a catalyst were added and reacted at 120 ° C for 7 hours . As a result of acid value measurement, it was confirmed that at least 98% of the acid anhydride was half-esterified, and the reaction was terminated to obtain a polyvinyl alcohol (H2-2) solution having a carboxyl group with a solid content of 50%. The resulting polyvinyl alcohol (H2-2) had a weight average molecular weight (Mw) of 8,600 and an acid value of 93 mgKOH / g.

&Lt; Preparation of polyvinyl alcohol (H2-3) having carboxyl group >

160 parts of ethyl acrylate, 30 parts of methyl methacrylate and 10 parts of methacrylic acid were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a gas introducing tube, and replaced with nitrogen gas. The inside of the reaction vessel was heated to 80 占 폚 and a solution of 0.1 part of 2,2'-azobisisobutyronitrile dissolved in 12 parts of 3-mercapto-1,2-propanediol was added and reacted for 10 hours. It was confirmed that 95% of the solid contents were reacted. 19 parts of pyromellitic anhydride, 231 parts of N-methyl-2-pyrrolidone and 0.40 parts of 1,8-diazabicyclo- [5.4.0] -7-undecene as a catalyst were added and reacted at 120 ° C for 7 hours . As a result of acid value measurement, it was confirmed that at least 98% of the acid anhydride was half-esterified, and the reaction was terminated to obtain a polyvinyl alcohol (H2-3) solution having a carboxyl group with a solid content of 50%. The weight average molecular weight (Mw) of the obtained polyvinyl alcohol (H2-3) was 8,400 and the acid value was 70 mgKOH / g.

· Polyester resin (H3) type with acidic functional group

<Preparation of polyester resin (H3-1) having carboxyl group>

62.6 parts of 1-dodecanol, 287.4 parts of epsilon -caprolactone and 0.1 part of monobutyltin (IV) oxide as a catalyst were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a stirrer, The mixture was heated and stirred at 120 DEG C for 4 hours. After confirming that 98% of the reaction was carried out by measuring the solid content, 36.6 parts of pyromellitic anhydride was added and the reaction was carried out at 120 ° C for 2 hours to obtain a polyester resin (H3-1) having a carboxyl group. The obtained polyester resin (H3-1) was a white waxy solid at room temperature.

&Lt; Preparation of polyester resin (H3-2) having carboxyl group >

169.0 parts of methoxy PEG400 (one terminal methoxylated polyethylene glycol; molecular weight of 400), 96.4 parts of? -Caprolactone, 84.6 parts of? -Valerolactone and 84.6 parts of? -Caprolactone as catalysts were placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a stirrer 0.1 part of monobutyltin (IV) oxide was added, the mixture was purged with nitrogen gas, and the mixture was heated and stirred at 120 DEG C for 4 hours. After confirming that 98% of the reaction was carried out by measuring the solid content, 62.2 parts of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride was added and reacted at 120 ° C for 2 hours to obtain a polyester resin having a carboxyl group (H3- 2). The obtained polyester resin (H3-2) was a light yellow transparent liquid at room temperature.

The resin (X) having an acidic functional group other than the above-mentioned (H1) to (H3)

(X1) Disperbyk-111 (trade name, manufactured by BYK Chemie): Resin having a phosphoric acid group

<Binder>

(1) KF polymer W # 1100 (trade name, manufactured by KUREHA CORPORATION): polyvinylidene fluoride (PVDF), weight average molecular weight about 280,000.

(2) PTFE 30-J (manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.): 60% polytetrafluoroethylene (PTFE) aqueous dispersion.

&Lt; Carbon black for conductive additive >

Denka Black HS-100 (trade name, manufactured by Denki Kagaku Kogyo Kabushiki Kaisha): acetylene black, primary particle size 48 nm, specific surface area 48 m 2 / g.

Denken Black FX-35 (Denki Kagaku Kogyo Kabushiki Kaisha, trade name): acetylene black, primary particle diameter 23 nm, specific surface area 133 m 2 / g.

Super-P Li (trade name, product of TIMCAL Co., Ltd.): furnace black, primary particle diameter 40 nm, specific surface area 62 m2 / g.

Hereinafter, the effect of the dispersing agent will be examined in detail in each of the examples.

(Example A and Comparative Example A)

The following discussion relates to an embodiment in which a derivative having a basic functional group as a dispersing agent is used singly or a mixture of an acidic compound and a derivative having a basic functional group is used. The electrode compound paste obtained in this embodiment is identified as the electrode compound paste (I) in Example G described later.

1-1. Surface treatment of positive electrode active material

Surface treatment of the positive electrode active material with a derivative having a basic functional group and / or a resin having an acidic functional group was carried out according to the composition and treatment method shown in Table 11. The amount of the resin having an acidic group is expressed in terms of solid content. Detailed processing methods are as follows.

[Surface-treated positive electrode active material (1)]

0.2 part of a derivative (B) having a basic functional group as a dispersing agent and 100 parts of a solvent (trade name) were added to 100 parts of lithium cobalt oxide (HLC-17, average primary particle diameter 2.5 탆, specific surface area 0.54 m 2 / g, And 25 parts of N-methyl-2-pyrrolidone (NMP), respectively, and the mixture was treated with two rolls to obtain a surface-treated positive electrode active material (1).

[Surface-treated positive electrode active material (2)]

To the kneader were added 100 parts of lithium manganese oxide (CELLSEEDS-LM, average primary particle diameter: 12.0 mu m, specific surface area: 0.48 m2 / g, manufactured by Nippon Chemical Industrial Co., LTD.) Serving as a positive electrode active material, (D) and 25 parts of NMP as a solvent, respectively, and kneaded. The obtained treated product was dried and pulverized to obtain a surface-treated positive electrode active material (2).

[Surface-treated positive electrode active material (3)]

0.2 part of a derivative (E) having a basic functional group as a dispersant and 100 parts of an acidic (meth) acrylic acid derivative were added to 100 parts of lithium nickel oxide (average primary particle size 9.0 mu m, specific surface area 0.3 m2 / g, manufactured by The Honjo Chemical Corporation) , 0.1 part of a resin (H2-1) having a functional group, and 43 parts of N, N-dimethylformamide (DMF) as a solvent, respectively, and kneaded. The obtained product was added to 1000 parts of hexane and stirred, and then the aggregated matter was filtered, dried and pulverized to obtain a surface-treated positive electrode active material (3).

[Surface-treated positive electrode active material (4)]

, 1.0 part of a derivative (H) having a basic functional group as a dispersing agent and 100 parts of a lithium salt of an acidic functional group were added to 100 parts of lithium iron phosphate (average primary particle diameter 0.2 mu m, specific surface area 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) 0.5 part of Resin (H3-2) was dissolved in 15 parts of NMP, followed by treatment with a dry jet mill to obtain a surface-treated positive electrode active material (4).

[Surface-treated positive electrode active material (5)]

(H) having a basic functional group as a dispersant were added to 100 parts of lithium phosphate (average primary particle size 0.2 mu m, specific surface area 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) -2-pyrrolidone (NMP) (25 parts), and the mixture was treated with two rolls to obtain a surface-treated positive electrode active material (5).

1-2. Evaluation of wettability of positive electrode active material with and without surface treatment

Various positive electrode active materials with no dispersing agent and the positive electrode active materials surface-treated with various dispersants were dried under reduced pressure at 80 DEG C for 10 hours. The dried material was pulverized by mortar, and further dried under reduced pressure at 80 DEG C for 12 hours. The obtained dried product was pulverized again with agate mortar, and a pellet of a positive electrode active material (diameter: 10 mm, thickness: 0.5 mm) was applied with a load of 500 kgf / cm 2 by a tableting machine (Specac). The pellet was mixed with ethylene carbonate and diethyl carbonate at a ratio of 1: 1 with a microsyringe, and the drop was dropped to measure the time required for the droplet to penetrate the pellet. This measurement was carried out five times for each sample and the wettability was evaluated according to the following criteria. The results of the wettability evaluation of the positive electrode active material are shown in Table 11.

(Evaluation standard)

◎: Average penetration time is less than 1 second.

○: Average penetration time is more than 1 second, less than 5 seconds.

△: Average penetration time is 5 seconds or more and less than 10 seconds.

×: Average penetration time is 10 seconds or more.

The abbreviations in Table 11 are as follows.

1) derivatives: derivatives having basic functional groups (see Tables 1 to 4), compounds having no basic functional groups and functional groups (see Table 5)

2) Acid Resin: Resin having an acidic functional group

2-1. Preparation of dispersion of positive electrode active material

Each dispersion was prepared as shown below.

[Positive electrode active material dispersion (1)]

In a container, 29.72 parts of N-methyl-2-pyrrolidone as a solvent and 0.28 part of a basic functional group A having a basic functional group as a dispersant were added and mixed and stirred to partially or completely dissolve the derivative to obtain a solution. Then, lithium cobalt oxide LiCoO ₂ , And the mixture was dispersed in a fill mix as a non-medium type dispersing machine to obtain a positive electrode active material dispersion (1).

[Preparation of positive electrode active material dispersion (2) to (4), (6) to (10), (12) to (15), (17) to (20), (23), (30) ]

(2) to (4), (6) to (10), (12) to (15), and (17) were prepared in the same manner as the preparation of the positive electrode active material dispersion (1) ) To (20), (23), (30) and (31).

[Positive electrode active material dispersion (16)]

29.65 parts of N, N-dimethylformamide as a solvent, and 0.14 part of a 50% solution of a polyvinyl alcohol (H2-1) having a carboxyl group as a dispersant were added to a container and mixed and stirred to obtain a solution completely or partially dissolved. Then, 70.21 parts of the surface-treated positive electrode active material (3) was added to the solution, and the mixture was dispersed with a fill mix as a non-medium type dispersing device to obtain a positive electrode active material dispersion (16).

(Preparation of positive electrode active material dispersion bodies (5), (11), (21) and (22)

The positive electrode active material dispersion bodies 5, 11, 21, and 22 were prepared in the same manner as the preparation of the positive electrode active material dispersion body 16 according to the composition of Table 12.

[Positive electrode active material dispersion (25)]

(PTFE, 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) (0.47 part) as a solvent and mixed and stirred to obtain a resin Was partially or completely dissolved to obtain a solution. Then, 70 parts of lithium cobalt oxide LiCoO ₂ as a positive electrode active material was added to this solution, and the mixture was dispersed in a fill mix as a non-medium type dispersing machine to obtain a positive electrode active material dispersion body 25.

[Preparation of positive electrode active material dispersion bodies (24) and (26) to (29)] [

The positive electrode active material dispersion bodies 24 and 26 to 29 were prepared in the same manner as the preparation of the positive electrode active material dispersion body 25 according to the composition of Table 12.

The abbreviations in Table 12 are as follows.

1) derivatives: derivatives having basic functional groups (see Tables 1 to 4), compounds having no basic functional groups and functional groups (see Table 5)

2) Acid Resin: Resin having an acidic functional group

3) NMP: N-methyl-2-pyrrolidone

4) DMF: N, N-dimethylformaldehyde

5) Binder 1: KF polymer W # 1100 (trade name, manufactured by KUREHA CORPORATION): polyvinylidene fluoride (PVDF), weight average molecular weight about 280,000.

6) Binder 2: 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE, 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.)

2-2. Evaluation of dispersion of the positive electrode active material dispersion (1) to (31)

The viscosity and dispersed particle size of the above-prepared positive electrode active material dispersion (1) to (31) were measured, and the results are shown in Table 13.

3. Preparation of Carbon Black Dispersion for Conducting Assay

Various carbon dispersions were prepared as shown below.

[Carbon dispersion (1)]

89.5 parts of N-methyl-2-pyrrolidone (NMP) and 0.5 part of a derivative (A) having a basic functional group were added to a glass bottle and mixed and stirred to obtain a solution completely or partially dissolved. 10 parts of carbon black HS-100 (acetylene black, primary particle size 48 nm, specific surface area 48 m 2 / g, manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) as a conductive additive was added to the solution, and zirconia beads were further added as a medium, And dispersed with a paint shaker to obtain a carbon dispersion (solid content 10.5%).

[Carbon dispersion (2)]

To a glass bottle, 88.5 parts of N-methyl-2-pyrrolidone (NMP) and 0.5 part (1 part as a solution) of resin (H2-1) having an acidic functional group were added and the resin was partially or completely dissolved to obtain a solution . Then, 0.5 part of the derivative (B) having a basic functional group was added to the solution, and the mixture was stirred to completely dissolve the derivative. Then, 10 parts of carbon black Super-P Li (furnace black, primary particle size: 40 nm, specific surface area: 62 m 2 / g, manufactured by TIMCAL CO., LTD.) Serving as a conductive additive was added and the mixture was further dispersed with a paint shaker To obtain a carbon dispersion (solid content: 11%).

[Carbon dispersion (3)]

89.5 parts of purified water and 0.125 parts of acetic acid were added to the glass bottle, and the solution was thoroughly mixed. Then, 0.375 part of a derivative (J) having a basic functional group was added to the above mixed solution, and the mixture was stirred and mixed to completely or partially dissolve the derivative to obtain a solution. 10 parts of carbon black HS-100 (acetylene black, primary particle size 48 nm, specific surface area 48 m 2 / g, manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) as a conductive additive was added to the solution, and zirconia beads were further added as a medium, And dispersed with a paint shaker to obtain a carbon dispersion (solid content 10.5%).

4. Preparation of positive electrode mixture paste for lithium secondary battery

Using the positive electrode active material dispersion (1) to (31) prepared above, carbon black or the previously prepared carbon dispersions (1) to (3), a binder and a solvent, (23) and comparative positive electrode material mixture pastes (1) to (8) were prepared.

[Example A1]

2.3 parts of polyvinylidene fluoride (PVDF, KF polymer W # 11000, manufactured by KUREHA CORPORATION) as a binder and 30.9 parts of N-methyl-2-pyrrolidone as a solvent were added to 64.3 parts of the positive electrode active material dispersion 1, After mixing with a planetary mixer, 2.5 parts of DENKA BLACK HS-100 as a conductive auxiliary additive was added to the mixture, and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste (1). The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (derivative having basic functional group + acid compound + binder) = 90/5/5.

[Examples A2 to A5, Comparative Example A1]

(2) to (5) and a comparative positive electrode material mixture paste (1) were prepared according to the composition shown in Table 14, in the same manner as in Example A1. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (derivative having basic functional group + acid compound + binder) = 90/5/5.

[Examples A6 to A8, A10, Comparative Example A2]

Positive electrode compound pastes (6) to (8), (10) and comparative compound paste (2) were prepared in the same manner as in Example A1 according to the composition shown in Table 14. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (derivative having a basic functional group + acid compound + binder) = 85/9/6.

[Examples A11 to A13, A15, Comparative Example A3]

Positive electrode compound pastes (11) to (13), (15) and Comparative Positive electrode compounded paste (3) were prepared in the same manner as in Example A1, The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (derivative having a basic functional group + acid compound + binder) = 91/4/5.

[Examples A16 to A21, Comparative Examples A4, A7, A8]

Positive electrode compound pastes (16) to (21) and comparative positive electrode compound pastes (4), (7) and (8) were prepared in the same manner as in Example A1, The resulting paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (a derivative having a basic functional group + an acidic compound + a compound having no basic functional group and no acidic functional group + binder) = 91/4/5 .

[Example A9]

0.0425 part of a derivative M having a basic functional group, 0.0425 part of a polyvinylidene fluoride resin (H1-1) having a sulfonic acid group as an acidic compound, 2.915 parts of polyvinylidene fluoride (PVDF, KF polymer W # 11000, manufactured by KUREHA CORPORATION) And 50 parts of N-methyl-2-pyrrolidone (NMP) as a solvent were mixed and stirred with a high-speed disper to obtain a mixture. To the mixture, lithium manganese oxide LiMn ₂ O ₄ And 4.5 parts of DENKA BLACK HS-100 as a conductive auxiliary additive were added and kneaded with a planetary mixer to obtain a positive electrode material mixture paste 9. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (derivative having basic functional group + acid compound + binder) = 85/9/6.

[Example A14]

0.091 part of a derivative O having a basic functional group, 0.091 part of a polyester resin (H3-1) having a carboxyl group as an acidic compound, 2.318 parts of polyvinylidene fluoride (PVDF, KF polymer W # 11000, manufactured by KUREHA CORPORATION) 50 parts of N-methyl-2-pyrrolidone (NMP) were mixed and stirred with a high-speed disper to obtain a mixture. To the mixture was added 45.5 parts of lithium nickel oxide LiNiO ₂ as a positive electrode active material and ₂ parts of a conductive auxiliary raw material, Adeka black HS-100, and kneaded with a planetary mixer to obtain a positive electrode material mixture paste. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (derivative having basic functional group + acid compound + binder) = 91/4/5.

[Example A22]

3.9 parts of a 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) as a binder and 29.4 parts of purified water were mixed with 64.3 parts of the positive electrode active material dispersion 6, And mixed with a tumble mixer to obtain a mixed solution. To the mixture was added 2.5 parts of a conductive auxiliary raw material, Denka Black HS-100, and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste 22. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (derivative having basic functional group + acid compound + binder) = 90/5/5.

[Comparative Example A5]

A comparative positive electrode material mixture paste (5) was prepared in the same manner as in Example A22 according to the composition shown in Table 15. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (derivative having basic functional group + acid compound + binder) = 90/5/5.

[Example A23]

2.5 parts of a 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) and 12.5 parts of purified water were added to 65.0 parts of the positive electrode active material dispersion 23 as a binder, Lt; / RTI &gt; mixer to obtain a mixture. Then, 20.0 parts of the carbon dispersion (3) was added to the mixture as a conductive auxiliary agent, and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste (23). The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (derivative having basic functional group + acid compound + binder) = 91/4/5.

[Comparative Example 6]

A comparative positive electrode material mixture paste 6 was prepared according to the composition shown in Table 15 in the same manner as in Example A23. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (derivative having basic functional group + acid compound + binder) = 91/4/5.

The abbreviations in Table 14 are as follows.

1) derivatives: derivatives having basic functional groups (see Tables 1 to 4), compounds having no basic functional groups and acidic functional groups (see Table 5)

2) In Example A9, carbon and a binder were collectively dispersed together in the composition of a derivative / acidic compound having a positive electrode active material / basic functional group of the dispersion 10 of Table 12 without using the positive electrode active material dispersion 10.

3) In Example A14, carbon and a binder were collectively dispersed together in the composition of a derivative / acidic compound having a positive electrode active material / basic functional group of the dispersion 15 of Table 12 without using the positive electrode active material dispersion 15. [

4) NMP: N-methyl-2-pyrrolidone

5) DMF: N, N-dimethylformamide

6) PVDF: polyvinylidene fluoride (KF polymer W # 1100, manufactured by KUREHA CORPORATION)

The abbreviations in Table 15 are as follows.

1) Derivatives: Derivatives having basic functional groups (see Tables 1 to 4)

2) PTFE: Polytetrafluoroethylene (60% polytetrafluoroethylene PTFE aqueous dispersion, PTFE 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.)

5-1. Fabrication of cathode for lithium secondary battery

The positive electrode material mixture pastes (1) to (23) prepared in Examples A1 to A23 and the comparative positive electrode material mixture pastes (1) to (8) prepared in Comparative Examples A1 to A8 were placed on an aluminum foil Using a doctor blade, dried under reduced pressure, and subjected to a rolling treatment by roll press or the like to produce a positive electrode material mixture layer having a thickness of 60 占 퐉 (see Tables 14 and 15).

5-2. Assembly of cell for evaluation of lithium secondary battery

The above-prepared positive electrode was punched into a diameter of 9 mm and used as a working electrode. A separator (made by Celgard Co. # 2400) made of a porous polypropylene film was interposed between the working electrode and the counter electrode with a metal lithium foil (thickness: 0.15 mm) And filled with an electrolytic solution to assemble a two-pole sealed metal cell (HS flat cell manufactured by Hohsen Corp.). A nonaqueous electrolyte solution prepared by dissolving LiPF ₆ at a concentration of 1 M in a mixed solvent in which ethylene carbonate and diethyl carbonate were mixed at a ratio of 1: 1 was used as the electrolyte solution. The cells were assembled in a grate box substituted with argon gas, and cell characteristics were evaluated after the cells were assembled.

5-3. Characterization of Lithium secondary charge polarity

The positive electrode characteristics of the lithium secondary battery were evaluated as described below using the lithium secondary battery designation electrode evaluation cell manufactured as described above.

[Charge / discharge cycle characteristics: Examples A1 to A15 and A22, Comparative Examples A1 to A3 and A5]

The prepared cell evaluation cell was fully charged at a constant current constant voltage charge (upper limit voltage 4.2 V) at a charging rate of 0.2 C and 1.0 C at room temperature (25 캜), discharged at a constant current of the same rate as that at the time of charging, (Evaluation apparatus: HOKUTO DENKO CORPORATION, SM-8) was carried out by carrying out charge and discharge in one cycle (charging / discharging interval stopping time 30 minutes) And the appearance of the electrode coating film was visually confirmed. The evaluation results are shown in Tables 16 and 17.

[Charge / discharge cycle characteristics: Examples A16 to A21 and A23, Comparative Examples A4 and A6 to A8]

The prepared cell evaluation cell was fully charged at a constant current constant voltage (4.5 V) at a charging rate of 0.2 C and 1.0 C at room temperature (25 캜), discharged at a constant current of the same rate as that of charging, The charging and discharging was performed for 1 cycle (charging / discharging interval stop time 30 minutes), and this cycle was carried out for 20 cycles in total to evaluate the charging / discharging cycle characteristics (evaluation apparatus: HOKUTO DENKO CORPORATION SM-8). In addition, the cell after evaluation was disassembled to visually confirm the appearance of the electrode coating film. The evaluation results are shown in Tables 16 and 17.

[Measurement of direct current internal resistance: Examples A1 to A23, Comparative Examples A1 to A8]

The prepared cell evaluation cell was fully charged with a constant current constant voltage charge (upper limit voltage 4.2 V) at a room temperature (25 ° C) and a charging rate of 0.2 C, and was discharged for 5 seconds at a constant current rate of 0.1 C, 0.2 C, 0.5 C, The battery voltage was measured. The slope of the linear relationship obtained by plotting the voltage value with respect to the current value was defined as the internal resistance. The evaluation results are shown in Tables 16 and 17. In the case of using lithium cobalt oxide as the positive electrode active material in the table, the relative value when the internal resistance value of Example A1 was taken as 100 was shown. The relative value when the lithium manganese oxide was used as the positive electrode active material was represented by the internal resistance value measured in Example A6 as 100. In the case where lithium nickel oxide was used as the positive electrode active material, the relative value when the internal resistance measured in Example A11 was taken as 100 was shown. In the case of using lithium iron phosphate as the positive electrode active material, the relative value when the internal resistance measurement value of Example A16 was taken as 100 was shown.

As can be seen from Tables 12 to 17, the dispersibility of the positive electrode active material was improved by using a derivative having a basic functional group as a dispersant in each of the examples according to the present invention, and the dispersibility in the positive electrode material mixture paste and the stability . Compared with the comparative example, the internal resistance tends to decrease and the retention ratio of the battery capacity and the 20 cycle capacity is improved.

(Example B and Comparative Example B)

The following discussion relates to an embodiment in which a derivative having a basic functional group as a dispersant and a resin having a basic functional group are mixed and used. The electrode compounding paste obtained in this embodiment is identified as the electrode compounding paste (II) in Example G to be described later.

1-1. Surface treatment of positive electrode active material

Surface treatment of the positive electrode active material was performed with a derivative having a basic functional group and a resin having a basic functional group according to the composition and treatment method shown in Table 18. The amount of the resin having a basic functional group is expressed in terms of solid content. Detailed processing methods are as follows.

[Surface-treated positive electrode active material (1)]

(A) as a dispersing agent and 100 parts of basic (lithium) cobalt oxide (LiCoO ₂ , HLC-17, average primary particle diameter 2.5 탆, specific surface area 0.54 m 2 / 25 parts of N-methyl-2-pyrrolidone (NMP) as a solvent were added to 0.5 part of the dispersion resin (G1-1) solution (solid content 0.2 part), and the mixture was treated with two rolls and dried to obtain a surface-treated positive electrode active material .

[Surface-treated positive electrode active material (2)]

100 parts of lithium manganese oxide (LiMn ₂ O ₄ , CELLSEEDS-LM, average primary particle diameter 12.0 μm, specific surface area 0.48 m 2 / g, manufactured by Nippon Chemical Industrial Co., LTD.) Serving as a positive electrode active material was dispersed in a kneader 0.3 part of a basic derivative (E), 0.25 part of a basic dispersion resin (G1-2) solution (0.1 part of solid content) and 25 parts of N-methyl-2-pyrrolidone (NMP) as a solvent were kneaded. The obtained treated product was dried and pulverized to obtain a surface-treated positive electrode active material (2).

[Surface-treated positive electrode active material (3)]

0.5 parts of a basic derivative (I) as a dispersing agent and 100 parts of a basic dispersing agent were added to 100 parts of lithium iron phosphate (LiFePO ₄ , average primary particle diameter 0.2 μm, specific surface area 15 m 2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) 0.5 part of the resin (G1-3) solution (solid content 0.2 part) and 43 parts of N, N-dimethylformamide (DMF) as a solvent were put and kneaded. The obtained product was added to 1000 parts of hexane and stirred, and then the resulting aggregate was filtered, dried and pulverized to obtain a surface-treated positive electrode active material (3).

[Surface-treated positive electrode active material (4)]

1.5 parts of a basic derivative (M) as a dispersing agent and 100 parts of a resin having a basic functional group were dispersed in 100 parts of lithium iron phosphate (LiFePO ₄ , average primary particle diameter 0.2 μm, specific surface area 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) 1.67 parts (solid content: 0.5 parts) of (G2-1) was dissolved in 15 parts of N-methyl-2-pyrrolidone (NMP) and then treated while being shaken with a dry jet mill and dried to obtain a surface-treated positive electrode active material (4).

[Surface-treated positive electrode active material (5)]

The positive electrode active material of lithium iron phosphate (LiFePO _4, an average primary particle diameter 0.2㎛, a specific surface area 15㎡ / g, TIANJIN STL ENERGY TECHNOLOGY Co., Ltd.) based on 100 parts of the basic derivatives (B) 1.0 part and a basic resin dispersed in a dispersing agent (G2 -2) and 25 parts of N-methyl-2-pyrrolidone (NMP) as a solvent, and the mixture was treated with two rolls and dried to obtain a surface-treated positive electrode active material (5).

1-2. Evaluation of wettability of positive electrode active material with and without surface treatment

Various positive electrode active materials with no dispersing agent and the positive electrode active materials treated with various dispersants were dried under reduced pressure at 80 DEG C for 10 hours. The dried material was pulverized with agate, and further dried under reduced pressure at 80 DEG C for 12 hours. The obtained dried product was pulverized again with agate mortar, and a pellet of a positive electrode active material (diameter: 10 mm, thickness: 0.5 mm) was applied with a load of 500 kgf / cm 2 by a tableting machine (Specac). The pellet was mixed with ethylene carbonate and diethyl carbonate at a ratio of 1: 1 with a microsyringe, and the drop was dropped to measure the time required for the droplet to penetrate the pellet. This measurement was carried out five times for each sample, and the wettability was evaluated according to the following criteria. The results of the wettability evaluation of the positive electrode active material are shown in Table 18.

(Evaluation standard)

◎: Average penetration time is less than 1 second.

○: Average penetration time is more than 1 second, less than 5 seconds.

△: Average penetration time is 5 seconds or more and less than 10 seconds.

×: Average penetration time is 10 seconds or more.

The abbreviations in Table 18 are as follows.

1) Basic derivatives: Derivatives having basic functional groups (see Tables 1 to 4)

2) Basic resin: Resin having basic functional group

2-1. Preparation of dispersion of positive electrode active material

The following dispersions were prepared.

[Positive electrode active material dispersion (1)]

To the vessel were added 26.4 parts of N-methyl-2-pyrrolidone as a solvent, 0.1 part of a derivative (C) having a basic functional group as a dispersant and 3.5 parts of a resin (G1-1) solution having a basic functional group (solid content: 1.4 parts) And the dispersion was completely or partially dissolved by stirring to obtain a solution. Then, 70 parts of lithium cobalt oxide LiCoO ₂ as a positive electrode active material was added to the solution and dispersed in a homogenizer as a non-medium type disperser to obtain a positive electrode active material dispersion (1).

[Preparation of positive electrode active material dispersion (2) to (8)] [

(2) to (8) were prepared in the same manner as in the preparation of the positive electrode active material dispersion (1) according to the composition of Table 19.

[Positive electrode active material dispersion (9)]

To the vessel were added 28.84 parts of N-methyl-2-pyrrolidone as a solvent, 0.44 parts of a derivative (N) having a basic functional group as a dispersant and 0.23 parts (solid content: 0.07 parts) of a 30% solution of a resin having a basic functional group (G2-2) And the mixture was mixed and stirred to partially or completely dissolve the dispersant to obtain a solution. Then, 70.49 parts of the surface-treated positive electrode active material (3) was added to the solution and dispersed with a homogenizer as a non-medium type disperser to obtain a positive electrode active material dispersion (9).

[Positive electrode active material dispersion (10)]

The positive electrode active material dispersion 10 was prepared in the same manner as in the preparation of the positive electrode active material dispersion 9, according to the composition shown in Table 19.

[Positive electrode active material dispersion (11)]

29.22 parts of purified water as a solvent and 0.78 parts (solid content 0.47 parts) of a binder 2, that is, 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE, 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) And the mixture was mixed and stirred to partially or completely dissolve the dispersion to obtain a solution. Then, 70 parts of lithium phosphate LiFePO ₄ was added as a positive electrode active material to the solution, and the mixture was dispersed in a homogenizer as a non-medium type disperser to obtain a positive electrode active material dispersion body 11.

[Positive electrode active material dispersion (12)]

30 parts of N-methyl-2-pyrrolidone as a solvent and 70 parts of lithium phosphate LiFePO ₄ as a positive electrode active material were added to the vessel and dispersed with a homogenizer as a non-medium type disperser to obtain a positive electrode active material dispersion body 12.

The abbreviations in Table 19 are as follows.

1) Basic derivatives: Derivatives having basic functional groups (see Tables 1 to 4)

2) Basic resin: Resin having basic functional group

3) PTFE: polytetrafluoroethylene (water component)

4) NMP: N-methyl-2-pyrrolidone

2-2 Evaluation of dispersion of the positive electrode active material dispersion (1) to (12)

The viscosity and dispersed particle size of the above-prepared positive electrode active material dispersion bodies (1) to (12) were measured. Table 20 shows the results.

3. Preparation of positive electrode mixture paste for lithium secondary battery

Positive electrode material mixture pastes (1) to (12) and comparative positive electrode material mixture pastes (1) and (2) were prepared using the above-prepared positive electrode active material dispersions (1) to (12), carbon black, a binder and a solvent .

[Example B1]

1.536 parts of polyvinylidene fluoride (PVDF, KF polymer W # 11000, manufactured by KUREHA CORPORATION) as a binder and 31.678 parts of N-methyl-2-pyrrolidone as a solvent were added to 64.286 parts of the positive electrode active material dispersion 1, Mixed with a mixer. Then, 2.5 parts of DENKA BLACK HS-100 as a conductive auxiliary additive was added to the mixture and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste (1). The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (derivative having a basic functional group and resin + binder) = 90/5/5.

[Examples B2 to B9, Comparative Example B2]

(2) to (10) and comparative positive electrode material mixture paste (2) were prepared according to the composition of Table 21 in the same manner as in Example B1. Each of the resulting pastes had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (derivative having a basic functional group and resin + binder) = 90/5/5.

[Example B10]

To 64.286 parts of the positive electrode active material dispersion 10, 2.613 parts (solid content 1.568 parts) of a 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) And 30.601 parts of purified water were mixed with a planetary mixer. Then, 2.5 parts of DENKA BLACK HS-100 as a conductive additive was added and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste 10. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (derivative having a basic functional group and resin + binder) = 90/5/5.

[Comparative Example B1]

A comparative positive electrode material mixture paste (1) was prepared in the same manner as in Example B10 except that the positive electrode active material dispersion (11) was used. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (resin having basic functional group + binder) = 90/5/5.

The evaluation results of the dispersion stability of the positive electrode material mixture pastes (1) to (10) and the comparative positive electrode material mixture pastes (1) and (2) (initial and dispersed particle diameters after 3 days at 50 占 폚) are shown in Table 21.

표 21의 약칭은 이하와 같다.

The abbreviations in Table 21 are as follows.

delete

1) Basic derivatives: Derivatives having basic functional groups (see Tables 1 to 4)

2) Basic resin: Resin having basic functional group

3) PVDF: polyvinylidene fluoride

4) PTFE: polytetrafluoroethylene (water component)

5) NMP: N-methyl-2-pyrrolidone

4-1. Fabrication of cathode for lithium secondary battery

The positive electrode material mixture pastes (1) to (10) prepared in Examples B1 to B10 and comparative positive electrode material mixture pastes (1) and (2) prepared in Comparative Examples B1 and B2 were placed on an aluminum foil Using a doctor blade, dried under reduced pressure, and subjected to rolling treatment by roll press or the like to produce a positive electrode material mixture layer having a thickness of 50 占 퐉 (see Table 21).

4-2. Assembly of cell for evaluating positive electrode of lithium secondary battery

The above-prepared positive electrode was punched into a diameter of 9 mm and used as a working electrode. A separator made of a porous polypropylene film (manufactured by CELL GUARD Co., Ltd. # 2400) was inserted between the working electrode and the counter electrode with a metallic lithium foil (thickness 0.15 mm) And the electrolyte was filled to prepare a diaphragm closed metal cell (HS flat cell manufactured by Hohsen Corp.). A nonaqueous electrolyte solution prepared by dissolving LiPF ₆ at a concentration of 1 M in a mixed solvent in which ethylene carbonate and diethyl carbonate were mixed at a ratio of 1: 1 was used as the electrolyte solution. The cells were assembled in a grate box substituted with argon gas, and cell characteristics were evaluated after the cells were assembled.

4-3. Evaluation of positive electrode characteristics of lithium secondary battery

The positive electrode characteristics of the lithium secondary battery were evaluated using the above-prepared lithium secondary battery positive electrode evaluation cell as described below.

[Charging / discharging cycle characteristics Examples B1 to B10, Comparative Examples B1 and B2]

The prepared cell evaluation cell was fully charged at a constant current constant voltage charge (upper limit voltage 4.2 V) at a charging rate of 0.2 C and 1.0 C at room temperature (25 캜), discharged at a constant current of the same rate as that at the time of charging, The charging and discharging was performed for 1 cycle (charging / discharging interval stop time 30 minutes), and this cycle was carried out for 20 cycles in total to evaluate the charging / discharging cycle characteristics (evaluation apparatus: HOKUTO DENKO CORPORATION SM-8). In addition, the cell after evaluation was disassembled to visually confirm the appearance of the electrode coating film. The evaluation results are shown in Table 22.

[DC internal resistance measurement examples B1 to B10, Comparative examples B1 and B2]

The prepared cell evaluation cell was fully charged with a constant current constant voltage charge (upper limit voltage 4.2 V) at a room temperature (25 ° C) and a charging rate of 0.2 C, and was discharged for 5 seconds at a constant current rate of 0.1 C, 0.2 C, 0.5 C, The battery voltage was measured. The slope of the linear relationship obtained by plotting the voltage value with respect to the current value was defined as the internal resistance. The evaluation results are shown in Table 22. The table shows the relative values when the internal resistance value of Example B1 is taken as 100. [

As can be seen from Tables 18 to 22, the dispersibility of the positive electrode active material was improved by using a derivative having a basic functional group as a dispersant and a resin having a basic functional group in each of the examples according to the present invention, Acidity and aging stability were improved. In comparison with the comparative example, the internal resistance tends to decrease, and the battery capacity and the retention ratio of the 20-cycle capacity are improved.

(Example C and Comparative Example C)

The following discussion relates to an embodiment in which a derivative having an acidic functional group is used alone as a dispersant or a mixture of a resin having an acidic functional group and a resin having a basic functional group is used. The electrode compounding paste obtained in the present embodiment is identified as the electrode compounding paste (III) in Example G described later.

1-1. Surface treatment of positive electrode active material

Surface treatment of the positive electrode active material was performed with a derivative having an acidic functional group or a derivative having an acidic functional group and a resin having a basic functional group according to the composition and treatment method shown in Table 23. The amount of the resin having a basic functional group is expressed in terms of solid content. The detailed processing method is as follows.

[Surface-treated positive electrode active material (1)]

0.2 part of a derivative (Db) having an acidic functional group as a dispersing agent, and 0.2 part of a solvent (C) were added to 100 parts of lithium cobalt oxide (HLC-17, average primary particle diameter 2.5 탆, specific surface area 0.54 m 2 / g, manufactured by The Honjo Chemical Corporation) And 25 parts of N-methyl-2-pyrrolidone (NMP), respectively, and the mixture was treated with two rolls to obtain a surface-treated positive electrode active material (1).

[Surface-treated positive electrode active material (2)]

To the kneader, 100 parts of lithium manganese oxide (CELLSEEDS-LM, average primary particle diameter: 12.0 mu m, specific surface area: 0.48 m2 / g, manufactured by Nippon Chemical Industrial Co., LTD.) Serving as a positive electrode active material, (Dg) and 25 parts of N-methyl-2-pyrrolidone (NMP) as a solvent, respectively, and kneaded. The obtained treated product was dried and pulverized to obtain a surface-treated positive electrode active material (2).

[Surface-treated positive electrode active material (3)]

0.2 part of a derivative (Dl) having an acidic functional group as a dispersant and 100 parts of a basic functional group (Dl) were added to 100 parts of lithium nickel oxide (average primary particle diameter 9.0 mu m, specific surface area 0.3 m2 / g, product of The Honjo Chemical Corporation) (G2-2) and 43 parts of N, N-dimethylformamide (DMF) as a solvent, respectively, and kneaded. The treated material was added to 1000 parts of hexane and stirred, and then the aggregated material was filtered, dried and pulverized to obtain a surface-treated positive electrode active material (3).

[Surface-treated positive electrode active material (4)]

, 1.0 part of a derivative (Dq) having an acidic functional group as a dispersing agent and 100 parts of a resin having a basic functional group were added to 100 parts of lithium iron phosphate (average primary particle diameter 0.2 mu m, specific surface area 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) (G1-1) was dissolved in 15 parts of N-methyl-2-pyrrolidone (NMP) and treated while being shaken with a dry jet mill to obtain a surface-treated positive electrode active material (4).

[Surface-treated positive electrode active material (5)]

(Dr) having an acidic functional group as a dispersant (1.0 part) and 100 parts of a solvent (Nitrogen) were added to 100 parts of lithium iron phosphate (average primary particle diameter: 0.2 mu m, specific surface area: 15 m &lt; 2 &gt; / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) -2-pyrrolidone (NMP) (25 parts), and the mixture was treated with two rolls to obtain a surface-treated positive electrode active material (5).

1-2. Evaluation of wettability of positive electrode active material with and without surface treatment

Various positive electrode active materials with no dispersing agent and the positive electrode active materials surface-treated with various dispersants were dried under reduced pressure at 80 DEG C for 10 hours. The dried material was pulverized with agate, and further dried under reduced pressure at 80 DEG C for 12 hours. The obtained dried product was pulverized again with agate mortar, and a pellet of a positive electrode active material (10 mm in diameter and 0.5 mm in thickness) was produced by applying a load at 500 kgf / cm 2 using a tableting machine (Specac). The droplet mixed with ethylene carbonate and diethyl carbonate at a ratio of 1: 1 was poured into the pellet using a microsyringe, and the time for the droplet to permeate the pellet was measured. This measurement was carried out five times for each sample and the wettability was evaluated according to the following criteria. Table 23 shows the results of the wettability evaluation of the positive electrode active material.

(Evaluation standard)

◎: Average penetration time is less than 1 second.

○: Average penetration time is more than 1 second, less than 5 seconds.

△: Average penetration time is 5 seconds or more and less than 10 seconds.

×: Average penetration time is 10 seconds or more.

The abbreviations in Table 23 are as follows.

1) derivatives: derivatives having an acidic functional group (see Tables 6 to 10), compounds having no basic functional group and an acidic functional group (see Table 5)

2) Basic resin: Resin having basic functional group

2-1. Preparation of dispersion of positive electrode active material

Each dispersion was prepared as shown below.

[Preparation of positive electrode active material dispersion (1)] [

29.72 parts of N-methyl-2-pyrrolidone as a solvent and 0.28 parts of a derivative Da having an acidic functional group as a dispersant were added to the vessel, followed by mixing and stirring to completely or partially dissolve the derivative to obtain a solution. Then, lithium cobalt oxide LiCoO ₂ , And the mixture was dispersed in a fill mix as a non-medium type dispersing machine to obtain a positive electrode active material dispersion (1).

[Preparation of positive electrode active material dispersion (2) to (4), (6) to (10), (12) to (15), (17) to (20), (23), (30) ]

(2) to (4), (6) to (10), (12) to (15), and (17) were prepared in the same manner as in the preparation of the positive electrode active material dispersion (1) ) To (20), (23), (30) and (31).

[Positive electrode active material dispersion (16)]

29.56 parts of N, N-dimethylformaldehyde as a solvent, and 0.23 part of a 30% solution of a resin having a basic functional group (G2-2) were put in a container and mixed and stirred to partially dissolve the resin completely. Then, 70.21 parts of the surface-treated positive electrode active material (3) was added and dispersed with a fill mix as a non-medium type dispersing device to obtain a positive electrode active material dispersion (16).

(Preparation of positive electrode active material dispersion bodies (5), (11), (21) and (22)

The positive electrode active material dispersion bodies 5, 11, 21, and 22 were prepared in the same manner as the preparation of the positive electrode active material dispersion body 16 according to the composition of Table 24.

[Positive electrode active material dispersion (25)]

(PTFE, 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) (0.47 part) as a solvent and 29.53 parts of purified water and a binder 2, that is, 60% polytetrafluoroethylene PTFE aqueous dispersion Lt; RTI ID = 0.0 &gt; completely &lt; / RTI &gt; As the positive electrode active material, lithium cobaltate LiCoO ₂ , And the mixture was dispersed in a fill mix as an non-medium type dispersing machine to obtain a positive electrode active material dispersion body 25.

[Preparation of positive electrode active material dispersion bodies (24) and (26) to (29)] [

The positive electrode active material dispersion bodies 24 and 26 to 29 were prepared in the same manner as the preparation of the positive electrode active material dispersion body 25 according to the composition of Table 24.

The abbreviations in Table 24 are as follows.

1) derivatives: derivatives having an acidic functional group (see Tables 6 to 10), compounds having no basic functional group and an acidic functional group (see Table 5)

2) Basic resin: Resin having basic functional group

3) NMP: N-methyl-2-pyrrolidone

4) DMF: N, N-dimethylformaldehyde

2-2. Evaluation of dispersion of the positive electrode active material dispersion (1) to (31)

The viscosity and dispersed particle size of the positive electrode active material dispersion bodies (1) to (31) prepared as described above were measured. The results are shown in Table 25.

3. Preparation of Carbon Black Dispersion for Conducting Assay

Various carbon dispersions were prepared as shown below.

[Carbon dispersion (1)]

89.5 parts of N-methyl-2-pyrrolidone (NMP) as a solvent and 0.5 part of a derivative (Do) having an acidic functional group as a dispersant were added to a glass bottle and mixed and stirred to obtain a solution by completely dissolving or partially dissolving the derivative. 10 parts of carbon black HS-100 (acetylene black, primary particle size 48 nm, specific surface area 48 m 2 / g, manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) as a conductive additive was added to the solution, and further zirconia beads were added to the medium , And dispersed with a paint shaker to obtain a carbon dispersion (solid content 10.5%).

[Carbon dispersion (2)]

88.5 parts of N-methyl-2-pyrrolidone (NMP) as a solvent in a glass bottle and 0.5 part of a resin (H2) having a basic functional group as a dispersant were added and the resin was completely or partly dissolved to obtain a derivative (Dk) 0.5 parts were added and mixed and stirred to partially or completely dissolve the derivative to obtain a solution. 10 parts of carbon black Super-P Li (furnace black, primary particle diameter: 40 nm, specific surface area: 62 m &lt; 2 &gt; / g, manufactured by TIMCAL CO., LTD.) Serving as a conductive additive was added to the above solution and zirconia beads were further added thereto as a medium. To obtain a carbon dispersion (solid content: 11%).

[Carbon dispersion (3)]

89.5 parts of purified water as a solvent in a glass bottle and 0.5 part of a derivative (Ds) having an acidic functional group as a dispersant were added and mixed and stirred to partially or completely dissolve the derivative to obtain a solution. Then, 10 parts of carbon black HS-100 (acetylene black, primary particle size 48 nm, specific surface area 48 m 2 / g, manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) as a conductive additive was added to the solution, and further zirconia beads were added thereto as a medium , And dispersed with a paint shaker to obtain a carbon dispersion (solid content 10.5%).

4. Preparation of positive electrode mixture paste for lithium secondary battery

Using the positive electrode active material dispersion (1) to (31) prepared above, carbon black or the previously prepared carbon dispersions (1) to (3), a binder and a solvent, (23) and comparative positive electrode material mixture pastes (1) to (8) were prepared.

[Example C1]

2.32 parts of polyvinylidene fluoride (PVDF, KF polymer W # 11000, manufactured by KUREHA CORPORATION) as a binder and 30.9 parts of N-methyl-2-pyrrolidone as a solvent were added to 64.3 parts of the positive electrode active material dispersion 1, After mixing with a mixer, 2.5 parts of DENKA BLACK HS-100 as a conductive auxiliary additive was added to this mixture and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste (1). The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (a resin having an acidic functional group + a resin having a basic functional group + binder) = 90/5/5.

[Examples C2 to C5, Comparative Example C1]

(2) to (5) and a comparative positive electrode material mixture paste (1) were prepared according to the composition of Table 26 in the same manner as in Example C1. Each of the resulting pastes had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (a resin having an acidic functional group + a resin having a basic functional group + binder) = 90/5/5.

[Examples C6 to C8 and C10, Comparative Example C2]

Positive electrode compound pastes (6) to (8), (10) and comparative compound paste (2) were prepared according to the composition shown in Table 26 in the same manner as in Example C1. Each of the resulting pastes was found to have a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (a resin having an acidic functional group + a resin having a basic functional group + binder) = 85/9/6.

[Examples C11 to C13 and C15, Comparative Example C3]

Positive electrode compound pastes (11) to (13), (15) and Comparative Positive electrode compounded paste (3) were prepared according to the composition shown in Table 26 in the same manner as in Example C1. Each of the obtained pastes was found to have a solid content of 50% and a solid content weight ratio of positive electrode active material / carbon black / others (a resin having an acidic functional group + a resin having a basic functional group + binder) = 91/4/5.

[Examples C16 to C21, Comparative Examples C4, C7, C8]

Positive electrode compound pastes (16) to (21) and Comparative Positive electrode compound mixture paste (4) were prepared in the same manner as in Example C1 according to the composition shown in Table 26. Each of the obtained pastes was found to have a solid content of 50% and a solid content weight ratio of positive electrode active material / carbon black / others (a resin having an acidic functional group + a resin having a basic functional group + binder) = 91/4/5.

[Example C9]

0.0425 part of a derivative Df having an acidic functional group as a dispersant and 0.0425 part of a resin having a basic functional group (G2-2), 2.915 parts of polyvinylidene fluoride (PVDF, KF polymer W # 11000, manufactured by KUREHA CORPORATION) And 50 parts of methyl-2-pyrrolidone (NMP) were mixed and stirred with a high-speed disper to obtain a mixture. Then, 42.5 parts of lithium manganese oxide LiMn ₂ O ₄ as a positive electrode active material and 4.5 parts of a conductive additive Rodenka black HS-100 were added to the mixture and kneaded with a planetary mixer to obtain a positive electrode material mixture paste 9. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (a resin having an acidic functional group + a resin having a basic functional group + binder) = 85/9/6.

[Example C14]

0.091 parts of a derivative (De) having an acid functional group as a dispersant and 0.091 part of a resin having a basic functional group (H1), 2.318 parts of polyvinylidene fluoride (PVDF, KF polymer W # 11000, manufactured by KUREHA CORPORATION) 50 parts of 2-pyrrolidone (NMP) were mixed and stirred with a high-speed disper to obtain a mixture. To the mixture was added 45.5 parts of lithium nickel oxide LiNiO ₂ as a positive electrode active material and ₂ parts of a conductive auxiliary raw material, Adeka black HS-100, and kneaded with a planetary mixer to obtain a positive electrode material mixture paste. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (a resin having an acidic functional group + a resin having a basic functional group + binder) = 91/4/5.

[Example C22]

3.87 parts (solid content: 2.32 parts) of a 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) as a binder and 64.3 parts of a positive electrode active material dispersion And 29.33 parts of purified water were mixed with a planetary mixer. Then, 2.5 parts of DENKA BLACK HS-100 as a conductive auxiliary agent was added and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste 22. The resulting paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (derivative having an acidic functional group + binder) = 90/5/5.

[Comparative Example C5]

A comparative positive electrode material mixture paste 5 was prepared according to the composition shown in Table 27 in the same manner as in Example C22. The resulting paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (derivative having an acidic functional group + binder) = 90/5/5.

[Example C23]

To 65.0 parts of the positive electrode active material dispersion 23, 2.65 parts (solid content 1.59 parts) of a 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) 13.3 parts of purified water were mixed with a planetary mixer to obtain a mixture. To the mixture was added 19.05 parts (2.0 parts of solid content) of the carbon dispersion (3) as a conductive auxiliary agent and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste (23). The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (derivative having an acidic functional group + binder) = 91/4/5.

[Comparative Example C6]

A comparative positive electrode material mixture paste 6 was obtained in accordance with the composition shown in Table 27 in the same manner as in Example C23. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (derivative having an acidic functional group + binder) = 91/4/5.

The abbreviations in Table 26 are as follows.

1) derivatives: derivatives having an acidic functional group (see Tables 6 to 10), compounds having no basic functional group and an acidic functional group (see Table 5)

2) Basic resin: Resin having basic functional group

3) In Example C9, without using the positive electrode active material dispersion 10, the composition of the resin having the derivative / basic functional group having the positive electrode active material / acid functional group of the dispersion 10 of Table 24 was mixed and dispersed together with the carbon and the binder did.

4) In Example C14, without using the positive electrode active material dispersion 15, the composition of the resin having the derivative / basic functional group having the positive electrode active material / acid functional group of the dispersion 15 of Table 24 was mixed and dispersed together with the carbon and the binder did.

5) NMP: N-methyl-2-pyrrolidone

6) DMF: N, N-dimethylformamide

7) PVDF: Polyvinylidene fluoride (KF polymer W # 1100, manufactured by KUREHA CORPORATION)

The abbreviations in Table 27 are as follows.

1) derivatives: derivatives having acidic functional groups (see Tables 6 to 10)

2) Basic resin: Resin having basic functional group

3) PTFE: Polytetrafluoroethylene (60% polytetrafluoroethylene PTFE aqueous dispersion, PTFE 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.)

5-1. Fabrication of cathode for lithium secondary battery

The positive electrode material mixture pastes (1) to (23) prepared in Examples C1 to C23 and comparative positive electrode material mixture pastes (1) to (8) prepared in Comparative Examples C1 to C8 were placed on an aluminum foil Coated with a doctor blade, dried under reduced pressure, and subjected to rolling treatment by a roll press or the like to produce a positive electrode material mixture layer having a thickness of 50 占 퐉 (see Tables 26 and 27).

5-2. Assemble the cell for evaluation of lithium secondary battery

The above-prepared positive electrode was punched into a diameter of 9 mm and used as a working electrode. A separator made of a porous polypropylene film (manufactured by CELL GUARD Co., Ltd. # 2400) was inserted between the working electrode and the counter electrode with a metallic lithium foil (thickness 0.15 mm) And a two-pole closed metal cell (HS flat cell manufactured by Hohsen Corp.) was assembled by laminating and filling the electrolyte. As the electrolyte solution, a nonaqueous electrolyte solution in which LiPF ₆ was dissolved at a concentration of 1 M in a mixed solvent of ethylene carbonate and diethyl carbonate at a ratio of 1: 1 was used. The cells were assembled in a grate box substituted with argon gas, and cell characteristics were evaluated after the cells were assembled.

5-3 Evaluation of Charging Characteristics

The positive electrode characteristics of the lithium secondary battery were evaluated as described below using the lithium secondary battery designation electrode evaluation cell manufactured as described above.

[Charging / discharging cycle characteristics Examples C1 to C15 and C22, Comparative Examples C1 to C3 and C5]

The prepared cell evaluation cell was fully charged at a constant current constant voltage charge (upper limit voltage 4.2 V) at a charging rate of 0.2 C and 1.0 C at room temperature (25 캜), discharged at a constant current of the same rate as that at the time of charging, The charging and discharging was performed for 1 cycle (charging / discharging interval stop time 30 minutes), and this cycle was carried out for 20 cycles in total to evaluate the charging / discharging cycle characteristics (evaluation apparatus: HOKUTO DENKO CORPORATION SM-8). In addition, the cell after evaluation was disassembled to visually confirm the appearance of the electrode coating film. The evaluation results are shown in Tables 28 and 29.

[Charging / discharging cycle characteristics Examples C16 to C21 and C23, Comparative Examples C4, C6, C7, C8]

The prepared cell evaluation cell was fully charged at a constant current constant voltage (4.5 V) at a charging rate of 0.2 C and 1.0 C at room temperature (25 캜), discharged at a constant current of the same rate as that of charging, The charging and discharging was performed for 1 cycle (charging / discharging interval stop time 30 minutes), and this cycle was carried out for 20 cycles in total to evaluate the charging / discharging cycle characteristics (evaluation apparatus: HOKUTO DENKO CORPORATION SM-8). In addition, the cell after evaluation was disassembled to visually confirm the appearance of the electrode coating film. The evaluation results are shown in Tables 28 and 29.

[DC internal resistance measurement examples C1 to C23, comparative examples C1 to C8]

The prepared cell evaluation cell was fully charged with a constant current constant voltage charge (upper limit voltage: 4.2 V) at a room temperature (25 ° C) and a charging rate of 0.2 C and discharged for 5 seconds at a constant current rate of 0.1 C, 0.2 C, 0.5 C, The battery voltage was measured. The slope of the linear relationship obtained by plotting the voltage value with respect to the current value was defined as the internal resistance. The evaluation results are shown in Tables 28 and 29. In the case where lithium cobalt oxide was used as the positive electrode active material in the table, the relative value when the internal resistance measurement value of Example C1 was taken as 100 was shown. The relative value when the lithium manganese oxide was used as the positive electrode active material was taken as the internal resistance value of Example C6 was taken as 100. In the case where lithium nickel oxide was used as the positive electrode active material, the relative value when the internal resistance measurement value of Example C12 was taken as 100 was shown. In the case of using lithium iron phosphate as the positive electrode active material, the relative value when the internal resistance measurement value of Example C16 was taken as 100 was shown.

As can be seen from Tables 23 to 29, the dispersibility of the positive electrode active material was improved by using a derivative having an acidic functional group as a dispersant in each of the examples according to the present invention, and the dispersibility and the stability with time in the positive electrode material mixture paste . Compared with the comparative example, the internal resistance tends to decrease and the retention ratio of the battery capacity and the 20 cycle capacity is improved.

(Example D and Comparative Example D)

The following discussion relates to an embodiment in which a resin having a basic functional group as a dispersant is used alone. The electrode compounding paste obtained in this embodiment is identified by the electrode compounding paste (IV) for Example G to be described later.

1-1. Surface treatment of positive electrode active material

Surface treatment of the positive electrode active material with a resin having a basic functional group was carried out according to the composition and treatment method shown in Table 30. The amount of the resin having a basic functional group is expressed in terms of solid content. Detailed processing methods are as follows.

[Surface-treated positive electrode active material (1)]

The positive electrode active material of lithium cobalt oxide (LiCoO _2, HLC-17, mean primary particle size 2.5㎛, a specific surface area 0.54㎡ / g, The Honjo Chemical Corporation agent) to 100 parts, a resin having a basic functional group in the dispersant (G1-1 ) And 0.2 part of N-methyl-2-pyrrolidone (NMP) as a solvent, and the mixture was treated with two rolls and dried to obtain a surface-treated positive electrode active material (1).

[Surface-treated positive electrode active material (2)]

100 parts of lithium manganese oxide (LiMn ₂ O ₄ , CELLSEEDS-LM, average primary particle diameter 12.0 μm, specific surface area 0.48 m 2 / g, manufactured by Nippon Chemical Industrial Co., LTD.) Serving as a positive electrode active material was dispersed in a kneader 0.25 parts of a resin (G1-2) having a basic functional group (solid content: 0.1 part) and 25 parts of N-methyl-2-pyrrolidone (NMP) as a solvent were put respectively and kneaded. The obtained treated product was dried and pulverized to obtain a surface-treated positive electrode active material (2).

[Surface-treated positive electrode active material (3)]

A kneader, a resin (G1-3) of the positive electrode active material, lithium iron phosphate (LiFePO _4, an average primary particle diameter 0.2㎛, a specific surface area 15㎡ / g, TIANJIN STL ENERGY TECHNOLOGY Co., Ltd.) to 100 parts, having a basic functional group as a dispersing agent (Solid component: 0.2 part) and 43 parts of N, N-dimethylformamide (DMF) as a solvent, respectively, and kneaded. The resulting treated product was added to 1000 parts of hexane and stirred, and the resulting aggregate was filtered, dried and pulverized to obtain a surface-treated positive electrode active material (3).

[Surface-treated positive electrode active material (4)]

(G2-1) having a basic functional group as a dispersant was added to 100 parts of lithium iron phosphate (LiFePO ₄ , average primary particle diameter 0.2 μm, specific surface area 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) 0.5 part) was dissolved in 15 parts of N-methyl-2-pyrrolidone (NMP), treated while being shaken with a dry jet mill, and dried to obtain a surface-treated positive electrode active material (4).

[Surface-treated positive electrode active material (5)]

(G2-2) having a basic functional group as a dispersant were added to 100 parts of lithium iron phosphate (LiFePO ₄ , average primary particle diameter 0.2 μm, specific surface area 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) (Solid content: 1.0 part) and 25 parts of N-methyl-2-pyrrolidone (NMP) as a solvent were each put in two rolls and dried to obtain a surface-treated positive electrode active material (5).

1-2. Evaluation of wettability of positive electrode active material with and without surface treatment

Various positive electrode active materials with no dispersing agent and the positive electrode active materials surface-treated with various dispersants were dried under reduced pressure at 80 DEG C for 10 hours. The dried material was pulverized with agate, and further dried under reduced pressure at 80 DEG C for 12 hours. The obtained dried product was pulverized again with agate mortar, and a pellet of a positive electrode active material (10 mm in diameter and 0.5 mm in thickness) was produced by applying a load at 500 kgf / cm 2 using a tableting machine (Specac). The pellet was mixed with ethylene carbonate and diethyl carbonate at a ratio of 1: 1 with a microsyringe, and the drop was dropped to measure the time required for the droplet to penetrate the pellet. This measurement was carried out five times for each sample, and the wettability was evaluated according to the following criteria. Table 30 shows the results of the wettability evaluation of the positive electrode active material.

(Evaluation standard)

◎: Average penetration time is less than 1 second.

○: Average penetration time is more than 1 second, less than 5 seconds.

△: Average penetration time is 5 seconds or more and less than 10 seconds.

×: Average penetration time is 10 seconds or more.

The abbreviations in Table 30 are as follows.

1) Basic resin: Resin having basic functional group

2-1 Preparation of dispersion of positive electrode active material

Each dispersion was prepared as shown below.

[Positive electrode active material dispersion (1)]

29.72 parts of N-methyl-2-pyrrolidone as a solvent and 3.5 parts of a resin (G1-1) solution having a basic functional group as a dispersant (solid content: 1.4 parts) were placed in a container and mixed and stirred to partially or completely dissolve the resin Solution. Then, lithium cobalt oxide LiCoO ₂ , And the mixture was dispersed in a homogenizer as an non-medium type disperser to obtain a positive electrode active material dispersion (1).

[Preparation of positive electrode active material dispersion (2) to (8)] [

(2) to (8) were prepared in the same manner as in the preparation of the positive electrode active material dispersion (1) according to the composition shown in Table 31. [

[Positive electrode active material dispersion (9)]

29.56 parts of N-methyl-2-pyrrolidone as a solvent and 0.23 part of a 30% solution of a resin (G2-2) having a basic functional group as a dispersant were added to a container and mixed and stirred to obtain a solution by completely dissolving the resin. Then, 70.21 parts of the surface-treated positive electrode active material (3) was added to the solution and dispersed with a homogenizer as a non-medium type disperser to obtain a positive electrode active material dispersion (9).

[Preparation of positive electrode active material dispersion 10]

The positive electrode active material dispersion material 10 was prepared in the same manner as in the preparation of the positive electrode active material dispersion material 9 according to the composition shown in Table 31. [

[Positive electrode active material dispersion (11)]

(PTFE, 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) (0.47 part) as a solvent and mixed and stirred to obtain a resin Was partially or completely dissolved to obtain a solution. To the solution was added lithium iron phosphate LiFePO ₄ And dispersed with a homogenizer as a non-medium type disperser to obtain a positive electrode active material dispersion body 11.

(Preparation of positive electrode active material dispersion body 12)

To the vessel was added 30 parts of N-methyl-2-pyrrolidone as a solvent, 30 parts of iron lithium LiFePO ₄ , And the mixture was dispersed in a homogenizer as a non-medium type disperser to obtain a positive electrode active material dispersion body 12.

The abbreviations in Table 31 are as follows.

1) Basic resin: Resin having basic functional group

2) PTFE: polytetrafluoroethylene (water component)

3) NMP: N-methyl-2-pyrrolidone

2-2. Evaluation of dispersion of the positive electrode active material dispersions (1) to (12)

The viscosity and dispersed particle size of the positive electrode active material dispersion bodies (1) to (12) prepared as described above were measured. Table 32 shows the results.

3. Preparation of positive electrode mixture paste for lithium secondary battery

The positive electrode material mixture pastes (1) to (12) and the comparative positive electrode material mixture paste (1) and the positive electrode material mixture paste (1) were prepared according to the following examples using the above- (2) were prepared.

[Example D1]

1.6 parts of polyvinylidene fluoride (PVDF, KF polymer W # 11000, manufactured by KUREHA CORPORATION) as a binder and 31.6 parts of N-methyl-2-pyrrolidone were added to 64.3 parts of the positive electrode active material dispersion 1 in a planetary mixer To obtain a solution. To the solution was added 2.5 parts of a conductive auxiliary raw material, Denka Black HS-100, and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste (1). The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (resin having basic functional group + binder) = 90/5/5.

[Examples D2 to D9, Comparative Example D2]

(2) to (10) and a comparative positive electrode material mixture paste (2) were prepared according to the composition of Table 33 in the same manner as in Example D1. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (resin having basic functional group + binder) = 90/5/5.

[Example D10]

3.79 parts (solid content 2.275 parts) of a 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) was added to 64.3 parts of the positive electrode active material dispersion 10, And purified water (29.41 parts) were mixed with a planetary mixer. Then, 2.5 parts of DENKA BLACK HS-100 as a conductive auxiliary agent was added and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste (10). The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (resin having basic functional group + binder) = 90/5/5.

[Comparative Example D1]

A comparative positive electrode material mixture paste (1) was prepared in the same manner as in Example D10 except that the positive electrode active material dispersion (11) was used instead of the positive electrode active material dispersion (10) according to the composition of Table 33. [ The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / other (resin having basic functional group + binder) = 90/5/5.

The dispersion stability of the positive electrode material mixture pastes (1) to (10) and the comparative positive electrode material mixture pastes (1) and (2) was measured after initial dispersion and after 3 days at 50 占 폚. The results are shown in Table 33.

The abbreviations in Table 33 are as follows.

1) Basic resin: Resin having basic functional group

2) PVDF: polyvinylidene fluoride

3) PTFE: polytetrafluoroethylene (water component)

4) NMP: N-methyl-2-pyrrolidone

4-1. Manufacture of lithium ion secondary electrode

The positive electrode material mixture pastes (1) to (12) prepared in Examples D1 to D12 and comparative positive electrode material mixture pastes (1) and (2) prepared in Comparative Examples D1 and D2 were placed on an aluminum foil Using a doctor blade, dried under reduced pressure, and subjected to rolling treatment by roll press or the like to produce a positive electrode material mixture layer having a thickness of 50 占 퐉 (see Table 33).

4-2. Assemble the cell for evaluation of lithium secondary battery

The above-prepared positive electrode was punched into a diameter of 9 mm and used as a working electrode. A separator made of a porous polypropylene film (manufactured by CELL GUARD Co., Ltd. # 2400) was inserted between the working electrode and the counter electrode with a metallic lithium foil (thickness 0.15 mm) And a two-pole closed metal cell (HS flat cell manufactured by Hohsen Corp.) was assembled by laminating and filling the electrolyte. As the electrolyte solution, a nonaqueous electrolyte solution in which LiPF ₆ was dissolved at a concentration of 1 M in a mixed solvent of ethylene carbonate and diethyl carbonate at a ratio of 1: 1 was used. The cells were assembled in a grate box substituted with argon gas, and cell characteristics were evaluated after the cells were assembled.

4-3. Characterization of Lithium secondary charge polarity

The positive electrode characteristics of the lithium secondary battery were evaluated as described below using the lithium secondary battery designation electrode evaluation cell manufactured as described above.

[Charging / discharging cycle characteristics Examples D1 to D12, Comparative Examples D1 and D2]

The prepared cell evaluation cell was fully charged at a constant current constant voltage charge (upper limit voltage 4.2 V) at a charging rate of 0.2 C and 1.0 C at room temperature (25 캜), discharged at a constant current of the same rate as that at the time of charging, The charging and discharging was performed for 1 cycle (charging / discharging interval stop time 30 minutes), and this cycle was carried out for 20 cycles in total to evaluate the charging / discharging cycle characteristics (evaluation apparatus: HOKUTO DENKO CORPORATION SM-8). In addition, the cell after evaluation was disassembled to visually confirm the appearance of the electrode coating film. The evaluation results are shown in Table 34.

[Direct Current Internal Resistance Measurement Examples D1 to D12, Comparative Examples D1 and D2]

The prepared cell evaluation cell was fully charged with a constant current constant voltage charge (upper limit voltage 4.2 V) at a room temperature (25 ° C) and a charging rate of 0.2 C, and discharged for 5 seconds at a constant current rate of 0.1 C, 0.2 C, 0.5 C, , And the battery voltage was measured. The slope of the linear relationship obtained by plotting the voltage value with respect to the current value was defined as the internal resistance. The evaluation results are shown in Table 34. The table shows the relative values when the internal resistance measurement of Example D1 is taken as 100.

As can be seen from Tables 30 to 34, the dispersibility of the positive electrode active material was improved by using the resin having a basic functional group in each of the examples according to the present invention, and the dispersibility and the stability over time in the positive electrode material mixture paste were improved compared with the comparative example . In addition, the internal resistance tended to decrease as compared with the comparative example, and the battery capacity and the 20 cycle capacity retention ratio were improved.

(Example E and Comparative Example E)

The following discussion relates to an embodiment in which a resin having an acidic functional group alone is used as a dispersant. The electrode compounding paste obtained in this embodiment is identified as the electrode compounding paste (V) in Example G to be described later.

1-1. Preparation of surface treatment of positive electrode active material

Surface treatment of the positive electrode active material with a resin having an acidic functional group was carried out in accordance with the composition and treatment method shown in Table 35. The amount of the resin having an acidic functional group was expressed in terms of solid content. Detailed processing methods are as follows.

[Surface-treated positive electrode active material (1)]

0.2 part of a resin (H1-1) having an acidic functional group as a dispersing agent and 100 parts of lithium cobalt oxide (HLC-17, average primary particle diameter 2.5 占 퐉, specific surface area 0.54 m2 / g, manufactured by The Honjo Chemical Corporation) And 25 parts of N-methyl-2-pyrrolidone (NMP) as a solvent were each added, and the mixture was treated with two rolls and dried to obtain a surface-treated positive electrode active material (1).

[Surface-treated positive electrode active material (2)]

100 parts of lithium manganese oxide (CELLSEEDS-LM, average primary particle diameter: 12.0 占 퐉, specific surface area: 0.48 m2 / g, manufactured by Nippon Chemical Industrial Co., LTD.) Serving as a positive electrode active material, (H2-1) solution (0.2 parts of solid content 0.1 part) and 25 parts of NMP as a solvent were kneaded, and the resulting product was dried and pulverized to obtain a surface-treated positive electrode active material (2).

[Surface-treated positive electrode active material (3)]

0.2 part of a resin (H2-2) solution having an acidic functional group as a dispersing agent was added to 100 parts of lithium iron phosphate (average primary particle diameter 0.2 mu m, specific surface area 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) (Solid content 0.1 part) and 43 parts of N-methyl-2-pyrrolidone (NMP) as a solvent, respectively, and kneaded. The resulting treated product was added to 1000 parts of hexane and stirred, and the resulting aggregate was filtered, dried and pulverized to obtain a surface-treated positive electrode active material (3).

[Surface-treated positive electrode active material (4)]

0.75 part of a resin (H3-1) having an acidic functional group as a dispersant was added to 15 parts of NMP with respect to 100 parts of lithium iron phosphate (average primary particle diameter 0.2 mu m, specific surface area 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) Treated while being treated with a dry jet mill, and dried to obtain a surface-treated positive electrode active material (4).

[Surface-treated positive electrode active material (5)]

1.5 parts of a resin (H3-2) having an acidic functional group as a dispersant and 0.1 part by weight of a solvent were added to 100 parts of a positive electrode active material lithium iron phosphate (average primary particle size: 0.2 mu m, specific surface area: 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY CO. And 25 parts of methyl-2-pyrrolidone (NMP), respectively. The mixture was treated with two rolls and dried to obtain a surface-treated positive electrode active material (5).

1-2. Evaluation of wettability of positive electrode active material with and without surface treatment

Various positive electrode active materials with no dispersing agent and each of the positive electrode active materials surface-treated with various dispersants in advance were dried under reduced pressure at 80 DEG C for 10 hours. The dried material was pulverized with agate, and further dried under reduced pressure at 80 DEG C for 12 hours. The obtained dried product was pulverized again with agate mortar, and a pellet of a positive electrode active material (diameter: 10 mm, thickness: 0.5 mm) was applied with a load of 500 kgf / cm 2 by a tableting machine (Specac). The pellet was mixed with ethylene carbonate and diethyl carbonate at a ratio of 1: 1 with a microsyringe, and the drop was dropped to measure the time required for the droplet to penetrate the pellet. This measurement was carried out five times for each sample and evaluated according to the following criteria. Table 35 shows the results of the wettability evaluation of the positive electrode active material.

(Evaluation standard)

◎: Average penetration time is less than 1 second.

○: Average penetration time is more than 1 second, less than 5 seconds.

△: Average penetration time is 5 seconds or more and less than 10 seconds.

×: Average penetration time is 10 seconds or more.

The abbreviations in Table 35 are as follows.

1) Acid Resin: Resin having an acidic functional group

2-1. Preparation of dispersion of positive electrode active material

Each dispersion was prepared as shown below.

[Positive electrode active material dispersion (1)]

28.6 parts of N-methyl-2-pyrrolidone as a solvent and 1.4 parts of a resin (H1-1) having an acidic functional group as a dispersant were added to the container, and the mixture was stirred to obtain a solution. Then, lithium cobalt oxide LiCoO ₂ , And the mixture was dispersed in a homogenizer as an non-medium type disperser to obtain a positive electrode active material dispersion (1).

[Preparation of positive electrode active material dispersion (2) to (8)] [

The dispersion was prepared according to the composition shown in Table 36 in the same manner as the preparation of the positive electrode active material dispersion 1 to prepare positive electrode active material dispersion bodies (2) to (8).

[Positive electrode active material dispersion (9)]

29.70 parts of N-methyl-2-pyrrolidone as a solvent and 0.23 part of a 30% solution of a resin (H3-1) having an acidic functional group as a dispersant (0.07 part of solid content) were added to the container and mixed and stirred to completely dissolve the resin To obtain a solution. Then, 70.07 parts of the surface-treated positive electrode active material (3) was added to the solution and dispersed with a homogenizer as a non-medium type disperser to obtain a positive electrode active material dispersion (9).

[Preparation of positive electrode active material dispersion 10]

29.47 parts of purified water as a solvent and 70.53 parts of surface-treated positive electrode active material (4) were placed in a vessel and dispersed in a homogenizer as an non-medium type dispersing machine to obtain a positive electrode active material dispersion body (10).

[Positive electrode active material dispersion (11)]

29.8 parts of purified water as a solvent and 0.78 parts of a 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE, 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) as a binder (0.47 parts of solid content) To partially dissolve the resin to obtain a solution. Then, 70 parts of lithium phosphate LiFePO ₄ was added as a positive electrode active material to the solution, and the mixture was dispersed in a homogenizer as a non-medium type disperser to obtain a positive electrode active material dispersion body 11.

(Preparation of positive electrode active material dispersion body 12)

30 parts of N-methyl-2-pyrrolidone as a solvent and 70 parts of iron lithium lithium LiFePO ₄ as a solvent were added to the vessel and dispersed with a homogenizer as a non-medium type dispersing machine to obtain a positive electrode active material dispersion body 12.

The abbreviations in Table 36 are as follows.

1) Acid Resin: Resin having an acidic functional group

2) NMP: N-methyl-2-pyrrolidone

2-2 Evaluation of dispersion of the positive electrode active material dispersion (1) to (12)

The viscosity and dispersed particle size of the positive electrode active material dispersion bodies (1) to (12) prepared as described above were measured. Table 37 shows the results.

3. Preparation of positive electrode mixture paste for lithium secondary battery

The positive electrode material mixture pastes (1) to (12) and the comparative positive electrode material mixture paste (1) and the positive electrode material mixture paste (1) were prepared according to the following examples using the above- (2) was prepared.

[Example E1]

1.6 parts of polyvinylidene fluoride (PVDF, KF polymer W # 11000, manufactured by KUREHA CORPORATION) as a binder and 31.6 parts of N-methyl-2-pyrrolidone as a solvent were added to 64.3 parts of the positive electrode active material dispersion 1, And mixed with a mixer to obtain a solution. To the solution was added 2.5 parts of a conductive auxiliary raw material, Denka Black HS-100, and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste (1). The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (resin having an acidic functional group + binder) = 90/5/5.

[Examples E2 to E9, Comparative Example E2]

(2) to (9) and comparative positive electrode material mixture paste (2) were prepared according to the composition shown in Table 38 in the same manner as in Example E1. Each of the resulting pastes had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (resin having an acidic functional group + binder) = 90/5/5.

[Example E10]

3.87 parts (solid content: 2.32 parts) of a 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) as a binder and 64.3 parts of a positive electrode active material dispersion And 29.33 parts of purified water were mixed with a planetary mixer to obtain a solution. To the solution was added 2.5 parts of a conductive auxiliary raw material, Denka Black HS-100, and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste 10. The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (resin having an acidic functional group + binder) = 90/5/5.

[Comparative Example E1]

A comparative positive electrode material mixture paste (1) was prepared in the same manner as in Example E10 except that the positive electrode active material dispersion (11) was used in place of the positive electrode active material dispersion (10). The obtained paste had a solid content of 50% and a solid content weight ratio of: positive electrode active material / carbon black / others (resin having an acidic functional group + binder) = 90/5/5.

The dispersion stability of the positive electrode material mixture pastes (1) to (10) and the comparative positive electrode material mixture pastes (1) and (2) prepared earlier was evaluated by measuring the dispersion particle size after three days at the initial stage and at 50 캜. Table 38 shows the results.

The abbreviations in Table 38 are as follows.

1) PVDF: polyvinylidene fluoride

2) PTFE: polytetrafluoroethylene

4-1. Preparation of cathode for lithium secondary battery

The positive electrode material mixture pastes (1) to (12) prepared in Examples E1 to E12 and comparative positive electrode material mixture pastes (1) and (2) prepared in Comparative Examples E1 and E2 were placed on an aluminum foil Coated with a doctor blade, heated and dried under reduced pressure, and subjected to rolling treatment by roll press or the like to produce a positive electrode material mixture layer having a thickness of 50 占 퐉 (see Table 38).

4-2. Assembly of cell for evaluation of lithium secondary battery

The above-prepared positive electrode was punched into a diameter of 9 mm and used as a working electrode. A separator (made by Celgard Co., # 2400) made of a porous polypropylene film was inserted between the working electrode and the counter electrode with a metal lithium foil (thickness 0.15 mm) And filled with an electrolytic solution to assemble a two-pole sealed metal cell (HS flat cell manufactured by Hohsen Corp.). As the electrolyte solution, a nonaqueous electrolyte solution in which LiPF ₆ was dissolved at a concentration of 1 M in a mixed solvent of ethylene carbonate and diethyl carbonate at a ratio of 1: 1 was used. The cells were assembled in a grate box substituted with argon gas, and cell characteristics were evaluated after the cells were assembled.

4-3. Evaluation of characteristics of lithium secondary battery

The positive electrode characteristics of the lithium secondary battery were evaluated as described below using the lithium secondary battery designation electrode evaluation cell manufactured as described above.

[Charging / discharging cycle characteristics Examples E1 to E12, Comparative Examples E1 and E2]

The prepared cell evaluation cell was fully charged at a constant current constant voltage charge (upper limit voltage 4.2 V) at a charging rate of 0.2 C and 1.0 C at room temperature (25 캜), discharged at a constant current of the same rate as that at the time of charging, The charging and discharging was performed for 1 cycle (charging / discharging interval stop time 30 minutes), and this cycle was carried out for 20 cycles in total to evaluate the charging / discharging cycle characteristics (evaluation apparatus: HOKUTO DENKO CORPORATION SM-8). In addition, the cell after evaluation was disassembled to visually confirm the appearance of the electrode coating film. The evaluation results are shown in Table 39.

[DC internal resistance measurement examples E1 to E12, comparative examples E1 and E2]

The prepared cell evaluation cell was fully charged at a constant current constant voltage charge (upper limit voltage 4.2 V) at a room temperature (25 ° C) and a charging rate of 0.2 C, and was discharged for 5 seconds at a constant current of 0.1 C, 0.2 C, 0.5 C, The battery voltage was measured. The slope of the linear relationship obtained by plotting the voltage value with respect to the current value was defined as the internal resistance. The evaluation results are shown in Table 39. The table shows the relative values when the internal resistance measurement of Example E1 was taken as 100. [

As can be seen from Tables 35 to 39, the dispersibility of the positive electrode active material was improved by using the resin having an acidic functional group in Examples, and the dispersibility and the stability over time in the positive electrode material mixture paste were improved as compared with Comparative Examples. Compared with the comparative example, the internal resistance tends to decrease and the retention ratio of the battery capacity and the 20 cycle capacity is improved.

(Example F and Comparative Example F)

The following discussion relates to an embodiment in which a vinylamide resin is used alone as a dispersing agent or a vinylamide resin is mixed with a derivative having a basic functional group or an acidic functional group. The electrode compounding paste obtained in this embodiment is identified as the electrode compounding paste (VI) in Example G described later.

1-1. Surface treatment of positive electrode active material

Surface treatment of the positive electrode active material was carried out with a vinylamide-based resin or a vinylamide-based resin and a derivative having a basic functional group or an acidic functional group according to the composition and treatment method shown in Table 40. [ The amount of vinylamide resin used is expressed in terms of solid content. The detailed processing method is as follows.

[Surface-treated positive electrode active material (1)]

0.2 part of a derivative (A) having a basic functional group as a dispersing agent and 100 parts of a N-methyl (meth) acrylate as a solvent were added to 100 parts of lithium iron phosphate (average primary particle size: 0.2 탆, specific surface area: 15 m 2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) -2-pyrrolidone (NMP) (25 parts), and the mixture was treated with two rolls to obtain a surface-treated positive electrode active material (1).

[Surface-treated positive electrode active material (2)]

To the kneader, 100 parts of lithium manganese oxide (CELLSEEDS-LM, average primary particle diameter: 12.0 mu m, specific surface area: 0.48 m2 / g, manufactured by Nippon Chemical Industrial Co., LTD.) Serving as a positive electrode active material, (Da) and 25 parts of NMP, kneaded, and dried and pulverized to obtain a surface-treated positive electrode active material (2).

[Surface-treated positive electrode active material (3)]

0.1 part of a derivative (J) having a basic functional group as a dispersing agent and 100 parts of a PVP (polytetrafluoroethylene) solution were added to 100 parts of lithium iron phosphate (average primary particle size: 0.2 탆, specific surface area: 15 m 2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) , And 43 parts of N, N-dimethylformamide (DMF) as a solvent, respectively, and kneaded. The obtained product was added to 1000 parts of hexane and stirred, and then the resulting aggregate was filtered, dried and pulverized to obtain a surface-treated positive electrode active material (3).

[Surface-treated positive electrode active material (4)]

1.5 parts of polyvinylpyrrolidone (PVP) as a dispersing agent was dissolved in 15 parts of NMP with respect to 100 parts of lithium phosphate (average primary particle diameter 0.2 mu m, specific surface area 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) And treated while being shaken with a dry jet mill to obtain a surface-treated positive electrode active material (4).

[Surface-treated positive electrode active material (5)]

1.5 parts of a derivative (D1) having an acidic functional group as a dispersing agent and 100 parts of N-methyl-2 (2-ethylhexyl) were added to 100 parts of lithium iron phosphate (average primary particle diameter 0.2 탆, specific surface area 15 m2 / g, manufactured by TIANJIN STL ENERGY TECHNOLOGY) -Pyrrolidone (NMP) (25 parts), and the mixture was treated with two rolls to obtain a surface-treated positive electrode active material (5).

1-2 Evaluation of wettability of positive electrode active material with and without surface treatment>

Various positive electrode active materials with no dispersing agent and each of the positive electrode active materials surface-treated with various dispersants were dried under reduced pressure at 80 DEG C for 10 hours. The dried material was pulverized with agate, and then dried under reduced pressure at 80 ° C for 12 hours. The obtained dried product was pulverized again with agate mortar, and a pellet of a positive electrode active material (10 mm in diameter and 0.5 mm in thickness) was produced by applying a load at 500 kgf / cm 2 using a tableting machine (Specac). The pellet was mixed with ethylene carbonate and diethyl carbonate at a ratio of 1: 1 with a microsyringe, and the drop was dropped to measure the time required for the droplet to penetrate the pellet. This measurement was carried out five times for each sample, and the wettability was evaluated according to the following criteria. Table 40 shows the results of the wettability evaluation of the positive electrode active material.

(Evaluation standard)

◎: Average penetration time is less than 1 second.

○: Average penetration time is more than 1 second, less than 5 seconds.

△: Average penetration time is 5 seconds or more and less than 10 seconds.

×: Average penetration time is 10 seconds or more.

The abbreviations in Table 40 are as follows.

1) derivatives: derivatives having basic functional groups (see Tables 1 to 4), derivatives having acidic functional groups (see Tables 6 to 10)

2-1 Preparation of dispersion of positive electrode active material

Each dispersion was prepared as shown below.

[Positive electrode active material dispersion 1 to 31]

Various solvents or water and, if necessary, a vinylamide resin were added to the container according to the composition shown in Table 41 to partially or completely dissolve the vinylamide resin. Then, any of the basic functional groups or the derivatives having an acidic functional group shown in Tables 1 to 4 or Tables 6 to 10 was added and mixed and stirred to partially or completely dissolve the derivative to obtain a solution. Then, a positive electrode active material was added to the solution and dispersed with a fillmix as a non-medium type disperser to obtain various positive electrode active material dispersion bodies.

The abbreviations in Table 41 are as follows.

1) derivatives: derivatives having basic functional groups (see Tables 1 to 4), derivatives having acidic functional groups (see Tables 6 to 10)

2) NMP: N-methyl-2-pyrrolidone

3) DMF: N, N-dimethylformaldehyde

4) PVP: polyvinylpyrrolidone

5) PNVA: poly-N-vinylamide

6) AGRIMER: AL-10LC (made by ISP JAPAN): alkylated polyvinylpyrrolidone / 1-butene = 90/10

2-2 Evaluation of dispersion of the positive electrode active material dispersion (1) to (31)

The viscosity and dispersed particle diameter of the positive electrode active material dispersion bodies (1) to (31) prepared as described above were measured. Table 42 shows the results.

3. Preparation of Carbon Black Dispersion for Conducting Assay

Various carbon dispersions were prepared as shown below.

[Carbon dispersion (1)]

In a glass bottle, N-methyl-2-pyrrolidone (NMP) and 0.5 part of a derivative (A) having a basic functional group were added and mixed and stirred to partially or completely dissolve the derivative to obtain a solution. 10 parts of carbon black HS-100 (acetylene black, primary particle size 48 nm, specific surface area 48 m 2 / g, manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) as a conductive additive was added to the solution, and further zirconia beads were added to the medium , And dispersed with a paint shaker to obtain a carbon dispersion (solid content 10.5%).

[Carbon dispersion (2)]

0.5 part of N-methyl-2-pyrrolidone (NMP) and 0.5 part of polyvinylpyrrolidone (PVP) were added to a glass bottle, and the resin was partially or completely dissolved and 0.5 part of an acidic functional group-containing derivative (M) The derivative was completely or partially dissolved to obtain a solution. 10 parts of carbon black Super-P Li (furnace black, primary particle diameter: 40 nm, specific surface area: 62 m &lt; 2 &gt; / g, manufactured by TIMCAL CO., LTD.) Serving as a conductive additive was added to the above solution and zirconia beads were further added thereto as a medium. To obtain a carbon dispersion (solid content 10.5%).

[Carbon dispersion (3)]

Purified water and 0.125 part of PNVA were put into a glass bottle and mixed thoroughly. Then, 0.375 parts of an acid functional group-containing derivative (J) was added and mixed and stirred to obtain a solution by completely or partially dissolving the derivative. Further, 10 parts of carbon black HS-100 (acetylene black, primary particle diameter 48 nm, specific surface area 48 m2 / g, manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) as a conductive additive was added to the above solution, and further zirconia beads were added thereto as a medium , And dispersed with a paint shaker to obtain a carbon dispersion (solid content 10.5%).

4. Preparation of positive electrode mixture paste for lithium secondary battery

The positive electrode material mixture paste and the comparative positive electrode material mixture paste were prepared according to the following examples using the above-prepared positive electrode active material dispersion and carbon black dispersion, respectively.

[Examples F1, F2, F5, F6, F11 to F20, F23 and F24, Comparative Examples F1 and F3]

Polyvinylidene fluoride PVDF (KF polymer W # 1100, manufactured by KUREHA CORPORATION) and N-methyl-2-pyrrolidone were added as a binder to the previously prepared dispersion of iron phosphate lithium LiFePO ₄ (91 parts by volume of LiFePO ₄ ) And mixed with a planetary mixer to obtain a solution. Carbon black or carbon dispersion (4 parts by carbon black amount) was added to the solution as a conductive auxiliary agent, and the mixture was kneaded again with a planetary mixer to obtain a positive electrode material mixture paste. Each of the obtained pastes had a solid content ratio of 50%, a solid content composition ratio; Active material / carbon black / binder and dispersant = 91/4/5 (see Table 43).

[Examples F3, F4, F7 to F10, F21 and F22, Comparative Example F2]

To the above prepared lithium manganate LiMn ₂ O ₄ dispersion (85 parts in terms of LiMn ₂ O ₄ ), polyvinylidene fluoride PVDF (KF polymer W # 1100, manufactured by KUREHA CORPORATION), N-methyl-2- Rawlidon was added and mixed with a planetary mixer to obtain a solution. Carbon black or a carbon dispersion (9 parts by carbon black amount) was added to the solution as a conductive auxiliary agent, and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste. Each paste obtained had a solid content ratio of 50%, a solid content composition ratio; The positive electrode active material / carbon black / binder and dispersant = 85/9/6 (see Table 43).

[Example F25, Comparative Example F4]

A 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE 30-J, Du Pont-Mitsui Fluorochemicals Co., Ltd.) was added to a previously prepared dispersion of lithium manganese oxide LiMn ₂ O ₄ (85 parts in terms of LiMn ₂ O ₄ ). , LTD.) And purified water were mixed and mixed with a planetary mixer to obtain a solution. Carbon black or a carbon dispersion (9 parts by carbon black amount) was added to the solution as a conductive auxiliary agent, and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste. Each paste obtained had a solid content ratio of 50%, a solid content ratio, a positive electrode active material / carbon black / binder and a dispersant = 85/9/6 (see Table 44).

[Example F26, Comparative Example F5]

A 60% polytetrafluoroethylene PTFE aqueous dispersion (PTFE 30-J, manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) was added to the previously prepared dispersion of iron phosphate lithium LiFePO ₄ (91 parts by volume of LiFePO ₄ ) , And purified water were added and mixed with a planetary mixer to obtain a solution. Then, carbon black or a carbon dispersion (4 parts by carbon black amount) was added to the solution as a conductive auxiliary agent and further kneaded with a planetary mixer to obtain a positive electrode material mixture paste. The obtained paste had a solid content ratio of 50%, a solid content composition ratio; Active material / carbon black / binder and dispersant = 91/4/5 (see Table 44).

The abbreviations in Table 43 are as follows.

1) derivatives: derivatives having basic functional groups (see Tables 1 to 4), derivatives having acidic functional groups (see Tables 6 to 10)

2) NMP: N-methyl-2-pyrrolidone

3) DMF: N, N-dimethylformaldehyde

4) PVP: polyvinylpyrrolidone

5) PNVA: poly-N-vinylamide

6) AGRIMER: AL-10LC (made by ISP JAPAN): alkylated polyvinylpyrrolidone / 1-butene = 90/10

The abbreviations in Table 44 are as follows.

1) derivatives: derivatives having basic functional groups (see Tables 1 to 4), derivatives having acidic functional groups (see Tables 6 to 10)

2) PVP: polyvinylpyrrolidone

3) PNVA: poly-N-vinylamide

4) PTFE: polytetrafluoroethylene

5-1. Fabrication of cathode for lithium secondary battery

Various positive electrode material mixture pastes prepared in Examples F1 to F26 and Comparative Examples F1 to F5 shown above were coated on an aluminum foil having a thickness of 20 mu m as a current collector using a doctor blade and then subjected to heat treatment under reduced pressure, To prepare a positive electrode material mixture layer having a thickness of 60 占 퐉 (see Tables 43 and 44).

5-2. Assemble the cell for evaluation of lithium secondary battery

A separator (manufactured by Celgard Co., # 2400) made of a porous polypropylene film was sandwiched between the working electrode and the counter electrode with a metal lithium foil (thickness 0.15 mm) as a counter electrode, And a 2-pole closed metal cell (HS flat cell manufactured by Hohsen Corp.) was assembled by filling the electrolyte solution. As the electrolyte solution, a nonaqueous electrolyte solution in which LiPF ₆ was dissolved at a concentration of 1 M in a mixed solvent of ethylene carbonate and diethyl carbonate at a ratio of 1: 1 was used. The cells were assembled in a grate box substituted with argon gas, and cell characteristics were evaluated after the cells were assembled.

5-3. Characterization of Lithium secondary charge polarity

The positive electrode characteristics of the lithium secondary battery were evaluated as described below using the lithium secondary battery designation electrode evaluation cell manufactured as described above.

[Charge and discharge cycle characteristics Examples F3, F4, F7 to F10, F21, F22 and 25, Comparative Examples F2 and F4]

The prepared cell evaluation cell was fully charged at a constant current constant voltage charge (upper limit voltage 4.2 V) at a charging rate of 0.2 C and 1.0 C at room temperature (25 캜), discharged at a constant current of the same rate as that at the time of charging, The charging and discharging was performed for 1 cycle (charging / discharging interval stop time 30 minutes), and this cycle was carried out for 20 cycles in total to evaluate the charging / discharging cycle characteristics (evaluation apparatus: HOKUTO DENKO CORPORATION SM-8). In addition, the cell after evaluation was disassembled to visually confirm the appearance of the electrode coating film. The evaluation results are shown in Tables 45 and 46.

[Charge / discharge cycle characteristics Examples F1, F2, F5, F6, F11 to F20, F23, F24 and F26, Comparative Examples F1, F3 and F5]

The prepared cell evaluation cell was fully charged at a constant current constant voltage (4.5 V) at a charging rate of 0.2 C and 1.0 C at room temperature (25 캜), discharged at a constant current of the same rate as that of charging, The charging and discharging were performed for one cycle (charging / discharging interval stopping time 30 minutes), and this cycle was carried out for 20 cycles in total to evaluate the charging / discharging cycle characteristics (evaluation device: HOKUTO DENKO CORPORATION SM-8). In addition, the cell after evaluation was disassembled to visually confirm the appearance of the electrode coating film. The evaluation results are shown in Tables 45 and 46.

[Direct Current Internal Resistance Measurement Examples F1 to F26, Comparative Examples F1 to F5]

The prepared cell evaluation cell was fully charged with a constant current constant voltage charge (upper limit voltage 4.2 V) at a room temperature (25 ° C) and a charging rate of 0.2 C, and the battery voltage was measured after a 5 second discharge at a constant constant current of 0.2 C and 1.0 C. The slope of the linear relationship obtained by plotting the voltage value with respect to the current value was defined as the internal resistance. The evaluation results are shown in Tables 45 and 46. In the table, lithium iron phosphate was used as the positive electrode active material, and the relative value when the internal resistance value of Example F1 was taken as 100 was shown. In the case where lithium manganese oxide was used as the positive electrode active material, the relative value when the internal resistance measured in Example F3 was taken as 100 was shown.

As can be seen from Tables 40 to 46, the use of the vinylamide resin as the positive electrode material mixture paste improves the dispersibility of the positive electrode active material in each of the examples according to the present invention, and the dispersibility and the stability with time in the positive electrode material mixture paste . The stability was further improved by using a derivative having a basic or acidic functional group. Compared with the comparative example, the internal resistance tends to decrease, and the battery capacity and the 20 cycle capacity retention ratio are improved.

(Example G)

The following discussion relates to comparison of the characteristics of the electrode compound pastes (I) to (VI) prepared in each of the foregoing Examples. The various pastes used in the following examination are as follows.

Electrode Composition Paste (I): Examples A1, A16, A18, A20

Electrode Composition Paste (II): Examples B3 and B6

Electrode Composition Paste (III): Examples C1, C17, C18, C20

Electrode Composition Paste (IV): Examples D3 and D4

Electrode Composition Paste (V): Examples E4 and E7

Electrode Composition Paste (VI): Examples F2 and F11

1. Comparative study of positive electrode characteristics (charge-discharge cycle characteristics) of lithium secondary battery

(Electrode compounding paste (I): Example A1 and electrode compounding paste (III): Example C1)

Charge-discharge cycle characteristics were evaluated according to the following procedure.

The battery evaluation cell produced in accordance with each of the examples was fully charged at a constant current constant voltage charge (upper limit voltage 4.2 V) at a charging rate of 0.2 C and 5.0 C at room temperature (25 캜), discharged at a constant current of the same rate as that at the time of charging, (Charging / discharging interval stopping time 30 minutes), and the charging and discharging cycles were carried out for a total of 20 cycles to evaluate the charging / discharging cycle characteristics (evaluation apparatus: SM-8 made by HOKUTO DENKO CORPORATION). The ratio of the initial capacity at the charge rate 5.0 C to the initial capacity at the charge rate 0.2 C was defined as the retention rate of the high rate discharge capacity.

The cell after the evaluation was disassembled and the appearance of the electrode coating film was visually confirmed. The adhesion of the coating film was evaluated in four steps according to the following criteria. The evaluation results are shown in Table 47.

(Evaluation standard)

⊚: No peeling at all, no significant change in charging / discharging cycle evaluation.

○: There is no peeling but there is some crack in the film.

?: Peeling of the electrode coating film is less than half.

X: Peeling of the electrode coating film is half or more.

C18 and C20, and electrode mixture paste (IV): Electrode compounding paste (I): Examples A16, A18 and A20, electrode compounding paste (II): Examples B3 and B6, electrode compounding paste (III) : Examples D3 and D4, electrode mixture paste (V): Examples E4 and E7, electrode mixture paste (VI): Examples E2 and E11]

Charge-discharge cycle characteristics were evaluated according to the following procedure.

The cells for evaluation of cells prepared in accordance with the respective examples were fully charged at a constant current constant voltage (5.0 V) at a charging rate of 0.2 C at room temperature (25 캜), discharged at a constant current of the same rate as that at the time of charging, (Charging / discharging interval stopping time 30 minutes), and the charging and discharging cycles were carried out for a total of 20 cycles to evaluate the charging / discharging cycle characteristics (evaluation apparatus: SM-8 made by HOKUTO DENKO CORPORATION). The ratio of the initial capacity at the charge rate 5.0 C to the initial capacity at the charge rate 0.2 C was defined as the retention rate of the high rate discharge capacity.

The cell after the above evaluation was disassembled and the appearance of the electrode coating film was visually confirmed, and the adhesion of the coating film was evaluated in four steps according to the following criteria. The evaluation results are shown in Table 47.

(Evaluation standard)

◎: No peeling at all and no significant change in charging / discharging cycle evaluation

○: No peeling, but some cracks in the film

?: Peeling of the electrode coating film is less than half

X: Peeling of the electrode coating film is half or more.

As can be seen from Table 47, with respect to the high rate discharge capacity retention rate, among the electrode compound pastes of this example, only the derivatives having a basic functional group or the derivative having an acidic functional group as the dispersant seen in Examples A16 and C17 were used It is possible to obtain better performance in the form. It is believed that this is because not only the dispersibility of the positive electrode active material is improved by the dispersing effect of the derivative having an acidic functional group or the acidic functional group-containing derivative, but also because the derivative is a low-molecular one. In other words, the coating of the derivative does not interfere with the interface between the positive electrode active material in the electrode coat film and the carbon black as the conductive additive, or the interface between the positive electrode active material and the current collector, and these interfaces can efficiently flow electrons .

With respect to the coating film adhesion after evaluation of the charge-discharge cycle, it is preferable to use a dispersant, which is found in Examples A18, A20, C18 and C20 among the electrode compound pastes of this embodiment, as a basic functional group or a derivative having an acidic functional group A better performance can be obtained in the embodiments in which a resin having a functional group or an acidic functional group is used in combination. This is because not only the effect of various derivatives exhibiting adsorptivity on the surface of the positive electrode active material but also the effect that the dispersant is firmly adsorbed to the surface of the positive electrode active material due to the acid salt phase interactions among various derivatives is added and the adhesion of the positive electrode active material to the current collector is improved do.

2. Evaluation of metal contamination resistance of lithium secondary battery

(1) Assembly of a cell for evaluating resistance to metal contamination

The positive electrode material mixture layer prepared in each of the above examples was cut into a width of 54 mm and a length of 500 mm and was wound with a separator made of polyethylene (film thickness 25 탆, width 58 mm, porosity 50%). This was placed in a battery can and the electrolyte solution was injected. After the injection, the battery was sealed by sealing the sealing portion. In addition, in this embodiment, in order to evaluate the cell resistance at the time of incorporation of a metal component, LiPF ₆ was dissolved at a concentration of 1 M in a solvent in which ethylene carbonate and diethyl carbonate were mixed at a ratio of 1: 1 as an electrolytic solution, A solution obtained by adding 10 ppm of Cu (BF ₄ ) ₂ or 50 ppm of Fe (CF ₃ SO ₂ ) ₂ in an iron source is used (see Table 48).

(2) Evaluation of charge / discharge cycle characteristics

Electrode compounding paste (I): Examples A16, A18 and A20 Electrode compounding paste (II): Examples B3 and B6 Electrode compounding paste (III): Examples C1, C17, C18 and C20 Electrode compounding paste Examples E3 and D4: Electrode compounding paste (V): Examples E4 and E7, Electrode compound paste (VI): Examples F2 and F11]

The produced battery was fully charged at a constant current constant voltage charge (upper limit voltage 4.5 V) at a room temperature (25 ° C) and a charging rate of 1.0 C, and was discharged at a constant current of the same rate as that at the time of charging until the voltage became 2.0 V Was set as one cycle (charging / discharging interval stopping time 30 minutes), and this cycle was performed for a total of 100 cycles or more. The capacity retention rate was determined from the initial discharge capacity and the discharge capacity at the 100th cycle and evaluated according to the following criteria. The evaluation results are shown in Table 48.

(Evaluation standard)

◎: Capacity retention rate is 95% or more.

○: Capacity retention rate is more than 90% and less than 95%.

DELTA: Capacity retention rate is 85% or more and less than 90%.

X: Capacity retention rate is less than 85%.

As can be seen from Table 48, the cells of this example were repeatedly charged and discharged stably for 100 cycles. Of these, in a preferred embodiment of the present invention, examples of the dispersant that can be seen in Examples A16 and C17 include a derivative having a basic functional group or a derivative having an acidic functional group alone. In another preferred embodiment of the present invention, examples of the dispersant that can be found in Examples B3 and B6 include a combination of a derivative having a basic functional group and a resin having a basic functional group. According to these embodiments, there is a tendency to obtain better performance.

Although not restricted by theory, various derivatives having an acidic functional group or a basic functional group are low in molecular weight, and thus have an acid value and an amine value per weight, which are the same as those of the resin, and are excellent in salt formation or adsorption with transition metal ions such as copper ion and iron ion. . As a result, it is considered that the capacity retention rate at 100 cycles is increased. Further, when a derivative having a basic functional group and a resin having a basic functional group are used in combination, each functional group of the derivative and the resin is likely to exist as a free basic functional group without being bonded to an acid salt phase interaction or the like. As a result, the transition metal ions are trapped more efficiently and the capacity retention ratio at 100 cycles is considered to be enhanced.

It is to be understood that the present invention is not limited by the specific embodiments thereof except as defined in the appended claims.

Claims (19)

Positive active material
A dispersant comprising a resin having a basic functional group,
The resin having a basic functional group
(C1) having an isocyanate group at both ends, which is obtained by the reaction of the hydroxyl group with the isocyanate group in the diisocyanate (B1) in the vinyl polymer (A1) having two hydroxyl groups at one terminal group (G1) Of the isocyanate group
At least one amino group selected from the group consisting of a primary amino group and a secondary amino group in an amine compound containing at least a polyamine (D1)
A polymer having an amine value of 1 to 100 mg KOH / g, and
(Meth) acryloyl group in the polymer (A2) having one or two (meth) acryloyl groups in the terminal end region of the (G2) terminal group and at least one kind selected from the group consisting of a primary amino group and a secondary amino group At least one kind of amino group selected from the group consisting of primary and secondary amino groups which are the amino groups in the polymer (C2) having an amino group obtained by the reaction with the amino group in the polyamine (B2)
The isocyanate group in the polyisocyanate (D2) having two or more isocyanate groups,
A polymer having an amine value of 5 to 100 mgKOH / g,
Wherein the positive electrode active material is at least one selected from the group consisting of a positive electrode active material and a negative electrode active material.
The method according to claim 1,
Wherein the dispersant further comprises at least one derivative selected from the group consisting of an organic dye derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, and a triazine derivative having a basic functional group (A), (B), (C), (D), (E) or (H), wherein the anthraquinone derivative having a basic functional group is represented by the following formula Wherein the acridone derivative having a basic functional group is a derivative of the following formula (G), and the triazine derivative having a basic functional group is represented by the following formulas (H) and (I) , (J), (K), (L), (M), (N) or (O).

The method according to claim 1,
Wherein the dispersant further comprises at least one derivative selected from the group consisting of an organic dye derivative having an acidic functional group and a triazine derivative having an acidic functional group and the organic functional derivative having an acidic functional group is represented by the following chemical formula Da, Dq, Dl, Dm, Dn, Do, Dp, Dq, or Ds, wherein the triazine derivative having an acidic functional group is represented by the following formula (D), (Db), (Dc), (Dd), (De), (Df), (Dg) Positive electrode mixture paste for lithium secondary battery.

The method according to claim 1,
In the polymer (G1), in the presence of the compound (a11) in which the vinyl polymer (A1) having two hydroxyl groups in the one terminal region has two hydroxyl groups and one thiol group in the molecule, the ethylenically unsaturated monomer (a12), which is a polymer obtained by radical polymerization of the polymer (a12).
The method according to claim 1,
Wherein the polymer (A2) having one or two (meth) acryloyl groups in the one end region of the polymer (G2) comprises a vinyl polymer or polyester.
6. The method according to any one of claims 1 to 5,
Further comprising a polyvinylidene fluoride or polytetrafluoroethylene as a dispersant and the other binder component, and a positive electrode material mixture paste for a lithium secondary battery.
6. The method according to any one of claims 1 to 5,
Wherein the positive electrode active material is lithium iron phosphate.
6. The method according to any one of claims 1 to 5,
The positive electrode material mixture paste for a lithium secondary battery further comprising a conductive auxiliary agent.
6. The method according to any one of claims 1 to 5,
The positive electrode material mixture paste for a lithium secondary battery further comprising a solvent.
A dispersant comprising a resin having a basic functional group of claim 1,
Positive active material
With conductive additives
Covalently bonding polyvinylidene fluoride or polytetrafluoroethylene to a solvent as a binder component different from the dispersant
(Method for producing positive electrode material mixture paste for lithium secondary battery).
A step of forming a dispersion by dispersing a dispersant and a positive electrode active material containing a resin having a basic functional group of claim 1 in a solvent,
And a step of mixing polyvinylidene fluoride or polytetrafluoroethylene as a binder component different from the dispersion, the conductive additive and the dispersing agent.
A method for producing a positive electrode material mixture paste for a lithium secondary battery, which comprises surface treating the positive electrode active material with a dispersant comprising a resin having a basic functional group of claim 1.
Comprising a positive electrode having a positive mixture layer on a first current collector, a negative electrode having a negative electrode mixture layer on a second current collector, and an electrolyte containing lithium interposed between the positive mixture layer and the negative electrode mixture layer, With the secondary battery,
Wherein the positive electrode material mixture layer is formed by using the positive electrode material mixture paste for a lithium secondary battery according to any one of claims 1 to 5.
13. The organic electroluminescent device according to any one of claims 10 to 12, wherein the dispersant is an organic dye derivative having a basic functional group, an anthraquinone derivative having a basic functional group, an acridone derivative having a basic functional group, and a tree having a basic functional group Wherein the positive electrode mixture paste further comprises at least one derivative selected from the group consisting of an azine derivative.
13. The process for producing a positive electrode material mixture paste for a lithium secondary battery according to any one of claims 10 to 12, wherein the dispersant further comprises an organic coloring matter derivative having an acidic functional group and a triazine derivative having an acidic functional group. delete delete delete delete

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