WO2019049510A1

WO2019049510A1 - Coating liquid for non-aqueous electrolyte battery separator, non-aqueous electrolyte battery separator using same, and non-aqueous electrolyte battery

Info

Publication number: WO2019049510A1
Application number: PCT/JP2018/026535
Authority: WO
Inventors: 俊充田中; 有紀太田; 能久乾; 岩崎　秀治
Original assignee: 株式会社クラレ
Priority date: 2017-09-11
Filing date: 2018-07-13
Publication date: 2019-03-14
Also published as: TW201912736A; JPWO2019049510A1

Abstract

The present invention provides: a coating liquid for a non-aqueous electrolyte battery separator, which exhibits excellent coatability on a separator substrate and with which a non-aqueous electrolyte battery separator having low electrical resistance and few cell short circuits can be advantageously obtained; a non-aqueous electrolyte battery separator using same; and a non-aqueous electrolyte battery. The present invention relates to: a coating liquid for a non-aqueous electrolyte battery separator, which contains a neutral salt of an α-olefin-maleic acid-based copolymer obtained by copolymerizing an α-olefin and a maleic acid compound, a polyamine and a solvent; a non-aqueous electrolyte battery separator; and a non-aqueous electrolyte battery.

Description

Coating solution for non-aqueous electrolyte battery separator, and non-aqueous electrolyte battery separator and non-aqueous electrolyte battery using the same

This patent application gives priority over the Paris Convention to Japanese Patent Application No. 2017-173760 (filing date: September 11, 2017) and No. 2018-74176 (filing date: April 6, 2018) And are hereby incorporated by reference in their entirety.
The present invention relates to a coating solution for a non-aqueous electrolyte battery separator, and a non-aqueous electrolyte battery separator and a non-aqueous electrolyte battery using the same.

In recent years, the spread of mobile terminals such as mobile phones, laptop computers, pad-type information terminals and the like has been remarkable. Nonaqueous electrolyte batteries are often used for secondary batteries used for power supplies of these portable terminals. As portable terminals are required to have more comfortable portability, miniaturization, thinning, weight reduction, and high performance have rapidly progressed, and they are used in various places. This trend continues, and batteries used in portable terminals are also required to be smaller, thinner, lighter and higher in performance.

In addition, large-sized devices such as electric vehicles, hybrid vehicles, and electric vehicles are also using non-aqueous electrolyte batteries. Therefore, performance such as high capacity and high current charge / discharge characteristics are required, but because it is a non-aqueous electrolyte battery, it has a high risk of smoke, ignition, rupture, etc. compared to water-based batteries. It is known and safety improvement is required.

In a non-aqueous electrolyte battery, a positive electrode and a negative electrode are installed via a separator, and a lithium such as LiPF ₆ , LiBF ₄ , LiTFSI (lithium (bis trifluoromethyl sulfonyl imide)), Li FSI (lithium (bis fluoro sulfonyl imide)) It has a structure housed in a container together with an electrolytic solution in which a salt is dissolved in an organic liquid such as ethylene carbonate.

Therefore, the risk of smoke and the like increases due to temperature rise due to external heat, overcharge, internal short circuit, external short circuit and the like. These can be prevented to some extent by the external protection circuit. In addition, the porous film of the polyolefin resin used as the non-aqueous electrolyte battery separator melts at around 120 ° C., and the holes are closed to block the flow of current or ions, thereby suppressing the temperature rise of the battery. It is also possible. This is called the shutdown function. However, if the temperature rises due to external heat or if a chemical reaction occurs inside the battery due to the temperature rise, the battery temperature will rise even if the shutdown function works and the battery temperature reaches 150 ° C or more, The porous film shrinks to cause an internal short circuit, which may cause ignition or the like.

As described above, it is difficult to suppress the firing of the battery by the shutdown function of the separator. Further, with the increase in capacity of batteries, the increase in current in charge and discharge is also in progress, and in order to suppress the Joule heat generated at that time, it is also necessary to lower the electric resistance value itself of the separator impregnated with the electrolyte. It has become. Therefore, by raising the heat shrinkage temperature more than the porous film of the polyolefin resin, internal short circuit is less likely to occur and the ignition of the battery is suppressed, and the metal oxide is used for the purpose of lowering the electric resistance value. Separators have been developed (eg, Patent Documents 1 and 2).

The formation of the heat-resistant layer in such a separator is performed by applying a paste-formed metal oxide on the surface of the separator. For example, Patent Document 3 discloses that a coating solution in which alumina fine particles are dispersed in carboxymethyl cellulose (hereinafter sometimes abbreviated as CMC) is applied to a microporous polyolefin membrane to obtain a battery separator.

However, CMC has good adhesion to metal oxides and separators, has thermal stability of about 150 ° C, but has high electrical resistance and high electrical resistance at high rate and repeated charge and discharge, so the temperature rise of the battery And internal short circuits are likely to occur. As a result, there is a problem that the heat is generated more than expected, the CMC is decomposed and it becomes difficult to function as a separator.

In view of such circumstances, as a resin composition for a non-aqueous electrolyte battery separator having a low electric resistance and a high heat resistance, a resin composition containing a neutralized salt of an α-olefins-maleic acid copolymer has been proposed ( Patent Document 4).

Japanese Patent Publication No. 2001-527274 JP, 2010-021033, A International Publication 2015/029944 Pamphlet International Publication 2017/022845 Pamphlet

However, in addition to obtaining a non-aqueous electrolyte battery separator with low electric resistance and high heat resistance, the separator coating liquid for a non-aqueous electrolyte battery having good coatability or adhesiveness to the separator substrate is also provided. The request still existed.

The present invention has been made in view of the above problems, and is excellent in coating properties to a separator substrate, and preferably, a non-aqueous electrolyte battery separator having low electric resistance and less short of cells is obtained. It is an object of the present invention to provide a coating solution for a water electrolyte battery separator, and a non-aqueous electrolyte battery separator and a non-aqueous electrolyte battery using the same.

The inventors of the present invention conducted intensive studies and found that a coating for a non-aqueous electrolyte battery comprising a neutralized salt of an α-olefin-maleic acid copolymer obtained by copolymerizing an α-olefin and a maleic acid, a polyamine and a solvent. It has been found that the above-mentioned problems can be solved by the working fluid, and the present invention has been completed.

That is, the present invention includes the following preferred embodiments.
[1] A coating liquid for a non-aqueous electrolyte battery separator, which comprises a neutralized salt of an α-olefin-maleic acid copolymer obtained by copolymerizing an α-olefin and a maleic acid, a polyamine and a solvent.
[2] The coating liquid for a separator as described in [1], further containing an aqueous emulsion.
[3] The aqueous emulsion contains at least one polymer particle selected from the group consisting of an olefin polymer, a diene polymer, an acrylic polymer, and a vinyl aromatic polymer, [2] The coating liquid for a separator as described in.
[4] The coating liquid for a separator as described in [2] or [3], wherein the aqueous emulsion has an average particle diameter of 0.01 to 0.5 μm.
[5] The solid content of the aqueous emulsion in the coating liquid is 0.01 to 50 parts by mass with respect to 100 parts by mass of the neutralized salt of the α-olefin-maleic acid copolymer. The coating liquid for a separator as described in [3] or [4].
[6] The coating liquid for nonaqueous electrolyte battery separator according to any one of [1] to [5], further containing at least one of a metal oxide and a metal salt.
[7] The coating liquid for a non-aqueous electrolyte battery separator according to any one of [1] to [6], wherein the solvent is water.
[8] The coating liquid for nonaqueous electrolyte battery separator according to any one of [2] to [6], wherein the aqueous emulsion is a particulate binder.
[9] A non-aqueous electrolyte battery separator comprising a separator substrate and a separator coating layer formed on the substrate from the coating liquid for a separator according to any one of [1] to [8].
The nonaqueous electrolyte battery which has a separator as described in [10] [9].

According to the present invention, it is preferable to obtain a non-aqueous electrolyte battery separator having low electric resistance and high heat resistance, and further to provide non-water having good coatability or adhesion to the separator substrate. The coating liquid for electrolyte battery separators can be obtained. Further, the separator for a non-aqueous electrolyte battery obtained from the coating solution for a non-aqueous electrolyte battery according to the present invention preferably has a low electric resistance and a high heat resistance, and further uses the same for non-aqueous electrolyte battery. The improvement of the battery characteristic of a water electrolyte battery can be realized.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited thereto.

The coating solution for a non-aqueous electrolyte battery according to the present invention (hereinafter, also simply referred to as a separator coating solution) is a neutralized salt of an α-olefin-maleic acid copolymer obtained by copolymerizing an α-olefin and a maleic acid. , Polyamines and a solvent. That is, the separator coating liquid of the present invention contains a polymer composition, preferably a binder composition, and a solvent, which is to be coated on a separator substrate to remove a solvent and to form a coating film. The coating solution for a non-aqueous electrolyte battery separator of the present invention may be a slurry composition.

An α-olefin-maleic acid copolymer obtained by copolymerizing an α-olefin and a maleic acid is composed of a unit (A) based on an α-olefin and a unit (B) based on a maleic acid, (A) and It is preferable that each component of (B) satisfy (A) / (B) = 1/1 to 1/3 (molar ratio). In addition, linear random copolymers having a weight average molecular weight of preferably 6,000 to 700,000, more preferably 8,000 to 650,000, more preferably 10,000 to 600,000 are preferred. . In one embodiment, a linear random copolymer having a weight average molecular weight of 10,000 to 500,000 is preferred.

Here, a unit (A) based on α-olefins has a general formula —CH ₂ CR ¹ R ² — (wherein R ¹ and R ² may be the same or different from each other, hydrogen, Or a constituent unit represented by the alkyl group having 1 to 10 carbon atoms or an alkenyl group). The α-olefins used in the present embodiment are linear or branched olefins having a carbon-carbon unsaturated double bond at the α-position. In particular, olefins having 2 to 12 carbon atoms, particularly 2 to 8 carbon atoms, are preferred. Representative examples of olefins that may be used include ethylene, propylene, n-butylene, isobutylene, n-pentene, isoprene, 2-methyl-1-butene, 3-methyl-1-butene, n-hexene, 2- Methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-butene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethylbutadiene, 2 And 5-pentadiene, 1,4-hexadiene, 2,2,4-trimethyl-1-pentene and the like. Among these, isobutylene is preferable from the viewpoint of availability, heavy synthesis, and stability of the product. Here, isobutylene also includes a mixture containing isobutylene as a main component, for example, a BB fraction (C4 fraction). These olefins may be used alone or in combination of two or more.

As units (B) based on maleic acids, maleic anhydride, maleic acid, maleic acid monoester (eg, methyl maleate, ethyl maleate, propyl maleate, phenyl maleate etc.), maleic acid diester (eg, maleic acid) Maleic anhydride derivatives such as dimethyl acid, diethyl maleate, dipropyl maleate, diphenyl maleate etc., maleinimido or its N-substituted derivatives (eg, maleinimido, N-methylmaleimide, N-ethylmaleimide, N N-substituted alkyl maleimide such as N-propyl maleimide, Nn-butyl maleimide, N-t-butyl maleimide, N-cyclohexyl maleimide, N-phenyl maleimide, N-methyl phenyl maleimide, N-ethyl phenyl maleimide, etc. Replace Alkylphenyl maleimide, or N-substituted alkoxyphenyl maleimide such as N-methoxyphenyl maleimide, N-ethoxyphenyl maleimide, etc., and further halides thereof (eg N-chlorophenyl maleimide), citraconic anhydride, citraconic acid, citraconic Anhydrides such as acid monoester (eg methyl citraconate, ethyl citraconate, propyl citraconate, phenyl citraconate etc.), citraconic diester (eg dimethyl citraconate, diethyl citraconate, dipropyl citraconate, citraconate diphenyl etc) Citraconic acid derivative, citraconic imide or N-substituted derivative thereof (eg, citraconic imide, 2-methyl-N-methylmaleimide, 2-methyl-N-ethylmaleimide, 2-methyl N-substituted alkyl maleimides 2-methyl-N-phenyl maleimide such as N-propyl maleimide, 2-methyl-Nn-butyl maleimide, 2-methyl-N-t-butyl maleimide, 2-methyl-N-cyclohexyl maleimide, etc. , 2-methyl-N-substituted alkylphenylmaleimides such as 2-methyl-N-methylphenylmaleimide, 2-methyl-N-ethylphenylmaleimide, etc., or 2-methyl-N-methoxyphenylmaleimide, 2-methyl-N- Preferred examples include 2-methyl-N-substituted alkoxyphenyl maleimides such as ethoxyphenyl maleimide and the like, and halides thereof (eg 2-methyl-N-chlorophenyl maleimide). Among these, in view of availability, polymerization rate and ease of molecular weight control, use of maleic anhydride is preferable. These maleic acids may be used alone or in combination of two or more. Maleic acids are neutralized with alkali salts as described above, and the carboxylic acids and carboxylates formed form the form of 1,2-dicarboxylic acid or its salts. This form has a function of capturing heavy metals eluted from the positive electrode.

The content ratio of each structural unit in the α-olefin-maleic acid copolymer is preferably such that (A) / (B) is in the range of 1/1 to 1/3 in molar ratio. This is because the advantages of hydrophilicity, water solubility, affinity to metals and ions as a high molecular weight soluble in water can be obtained. In particular, it is desirable that the molar ratio of (A) / (B) is 1/1 or a value close thereto, in which case a unit based on α-olefin, ie a unit represented by -CH ₂ CR ¹ R ^2- And a copolymer having a structure in which units based on maleic acids are alternately repeated.

Although the mixing ratio of the α-olefins and the maleic acid to obtain the α-olefin-maleic acid copolymer varies depending on the composition of the target copolymer, it is preferably 1 to 3 times the number of moles of the maleic acid. The use of α-olefins is effective to increase the conversion of maleic acid.

The method for producing the α-olefin-maleic acid copolymer is not particularly limited, and, for example, the copolymer can be obtained by radical polymerization. At that time, as a polymerization catalyst to be used, azo catalysts such as azobisisobutyronitrile, 1,1-azobiscyclohexane-1-carbonitrile, organic peroxide catalysts such as benzothio peroxide, dicumyl peroxide, etc. preferable. The amount of the polymerization catalyst used is usually in the range of 0.1 to 5 mol%, preferably 0.5 to 3 mol%, with respect to the maleic acid. As a method of adding the polymerization catalyst and the monomer, it may be collectively added at the initial stage of polymerization, but a method of sequentially adding according to the progress of polymerization is preferable.

In the method for producing an α-olefin-maleic acid copolymer, the adjustment of the molecular weight can be appropriately performed mainly depending on the monomer concentration, the amount of the catalyst used, and the polymerization temperature. For example, salts of metals of groups I, II or III of the periodic table, hydroxides, halides of metals of group IV as substances which lower the molecular weight, the general formula N≡, HN =, H ₂ N— or H It is also possible to control the molecular weight of the copolymer by adding an amine represented by ₄ N-, a nitrogen compound such as ammonium acetate or urea, or a mercaptan during the initial stage of polymerization or during the progress of polymerization. The polymerization temperature is preferably 40 ° C. to 150 ° C., and more preferably 60 ° C. to 120 ° C. When the polymerization temperature is too high, the resulting copolymer tends to be in the form of a block, and the polymerization pressure may be extremely high. The polymerization time is usually preferably about 1 to 24 hours, and more preferably 2 to 10 hours. The amount of the polymerization solvent to be used is preferably adjusted so that the resulting copolymer concentration is 5 to 40% by mass, more preferably 10 to 30% by mass.

As mentioned above, the α-olefin-maleic acid copolymer preferably has a weight average molecular weight of usually 6,000 to 700,000. A more preferable weight average molecular weight is 8,000 to 650,000, and a further preferable weight average molecular weight is 10,000 to 600,000. When the weight average molecular weight of the copolymer of the present embodiment is less than 6,000, the crystallinity is high, and the binding strength between particles may be reduced. On the other hand, when it exceeds 700,000, the solubility to water and a solvent may become small, and it may precipitate easily. In addition, from the viewpoint of improving the heat resistance of the separator using the coating liquid for a separator of the present invention, a weight average molecular weight of 250,000 or more is also a preferable embodiment. In one embodiment, the weight average molecular weight is preferably 15,000 to 450,000.

The weight average molecular weight of the α-olefin-maleic acid copolymer can be measured, for example, by a light scattering method or a viscosity method. When the intrinsic viscosity ([η]) in dimethylformamide is measured using a viscosity method, the copolymer preferably has an intrinsic viscosity in the range of 0.05 to 1.5. The copolymer is usually obtained in the form of powder in which particles of about 16 to 60 mesh are aligned.

In one embodiment of the present invention, the neutralization salt of the copolymer is one in which the active hydrogen of the carbonyl acid generated from the maleic acid reacts with the basic substance to form a salt to form a neutralization salt. Is preferred. In this embodiment, it is preferable to use a basic substance containing a monovalent metal and / or ammonia as the basic substance from the viewpoint of coatability.

In the above embodiment, the amount of use of the basic substance containing monovalent metal and / or ammonia is not particularly limited, and may be appropriately selected depending on the purpose of use, etc., but it is usually in the maleic acid copolymer The amount is preferably 0.6 to 2.0 moles per mole of maleic acid unit. With such an amount, the degree of neutralization of the α-olefin-maleic acid copolymer can be easily adjusted to a predetermined range. When the amount of the basic substance containing a monovalent metal used is preferably 0.8 to 1.8 moles per mole of maleic acid unit in the maleic acid copolymer, it is less soluble in alkali and water soluble. The copolymer salt of can be obtained.

The reaction of the α-olefin-maleic acid copolymer with the basic substance containing a monovalent metal and / or an amine such as ammonia can be carried out according to a conventional method, but it is carried out in the presence of water and α- The method of obtaining a neutralized salt of an olefin-maleic acid copolymer as an aqueous solution is convenient and preferred.

Examples of usable basic substances containing monovalent metals include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide and lithium hydroxide; carbonates of alkali metals such as sodium carbonate and potassium carbonate; Examples thereof include acetates of alkali metals such as sodium acetate and potassium acetate; and phosphates of alkali metals such as trisodium phosphate. Examples of amines such as ammonia include primary amines such as ammonia, methylamine, ethylamine, butylamine and octylamine, secondary amines such as dimethylamine, diethylamine and dibutylamine, and tertiary amines such as trimethylamine, triethylamine and tributylamine. It can be mentioned. Among these, ammonia, lithium hydroxide, sodium hydroxide and potassium hydroxide are preferable. In particular, use of ammonia and lithium hydroxide is preferable in terms of the coatability to the separator substrate. The basic substance containing a monovalent metal and / or ammonia may be used alone or in combination of two or more. Further, within the range not adversely affecting the battery performance, a neutralized substance of an α-olefin-maleic acid copolymer is additionally used together with a basic substance containing hydroxide of alkali metal such as sodium hydroxide and the like. May be prepared.

The degree of neutralization of the carboxylic acid generated from the maleic acid in the copolymer is preferably 0.3 to 1.0. Since the solubility to water or a solvent is favorable in the said neutralization degree being 0.3 or more, it is preferable at the point which can perform coating to a separator base material without precipitation. Further, when the degree of neutralization is 1.0 or less, the basic substance to be neutralized is present in excess in the slurry, which is preferable because there is no risk of becoming a resistance component. More preferably, the neutralization degree is in the range of 0.4 to 0.8.

The degree of neutralization can be measured using methods such as titration with a base, infrared spectrum, NMR spectrum, etc., but in order to measure the neutralization point simply and accurately, it is preferable to perform titration with a base. A specific titration method is not particularly limited, but the copolymer is dissolved in water with few impurities such as ion-exchanged water, and lithium hydroxide, sodium hydroxide, potassium hydroxide, etc. are used. It can be carried out by neutralization with a basic substance. The indicator of the neutralization point is not particularly limited, but an indicator such as phenolphthalein which indicates pH with a base may be used, and titration can also be performed using a PH meter.

The degree of neutralization of the copolymer may be adjusted, for example, by adjusting the degree of neutralization of the copolymer, or by directly adjusting the degree of neutralization of an aqueous solution in which the copolymer is dissolved. It is also good. Specifically, for example, adjustment of the degree of neutralization is performed by adjusting the amount of addition of the basic substance (ammonia, lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.) containing a monovalent metal as described above. Although it is possible to adjust to the said range by these, it is not limited to it. Specifically, as described above, the basic substance containing a monovalent metal and / or ammonia is preferably used in an amount of 0.6 to 2.0 moles per mole of maleic acid unit in the maleic acid copolymer. It can adjust to the said range by adding the quantity which becomes. More preferably, the basic substance containing a monovalent metal and / or ammonia is added more surely by adding 0.6 to 1.8 moles per mole of maleic acid unit in the maleic acid copolymer. The above range can be adjusted.

Also, when the maleic acid is maleic anhydride, with the neutralized salt of the copolymer, the active hydrogen of the carbonyl acid formed by the ring opening of maleic anhydride reacts with the basic substance as described above, It forms and becomes a neutralization thing. The degree of neutralization in this case is not particularly limited, but in view of the reactivity with the electrolytic solution, it is preferably in the range of 0.5 to 1 mole relative to 1 mole of carbonyl acid formed by ring opening. Preferably, it is preferable to use one neutralized in the range of 0.6 to 1 mole. With such a degree of neutralization, there is an advantage that the degree of acidity is low and electrolytic solution decomposition is suppressed. The degree of neutralization of the copolymer when maleic anhydride is used can be measured by the same method as described above.

Next, the ring-opening rate of the α-olefin-maleic acid copolymer represents the hydrolysis rate of the maleic anhydride moiety that is polymerized with the α-olefin when maleic anhydride is used as the maleic acid. In one embodiment of the present invention, the preferred ring opening ratio is 60 to 100%, more preferably 70% to 100%, still more preferably 80 to 100%. If the ring opening ratio is too low, the structural freedom of the copolymer decreases and the stretchability becomes poor, so that the force for bonding the adjacent electrode material particles may be reduced, which is not preferable. Furthermore, there is a risk of causing problems such as low affinity to water and poor solubility. The ring-opening rate can also be obtained, for example, by determining the ratio by measuring the hydrogen at the α-position of the ring-opened maleic acid by ¹ H-NMR based on the hydrogen located at the α-position of maleic anhydride It is also possible to obtain the ratio of the carbonyl group of maleic acid and the carbonyl group derived from the ring-opened maleic anhydride by IR measurement.

Furthermore, the coating liquid for non-aqueous electrolyte battery separators of this invention contains polyamines. By acting as a crosslinking agent in the coating liquid, the polyamines can improve the coatability of the separator coating liquid, and the resulting separator can have a low resistance. The separator coating liquid of the present invention has a structure in which the above-described neutralized salt of the α-olefin-maleic acid copolymer is crosslinked with polyamines.

Such polyamines are not particularly limited as long as they are electrochemically stable, and any polyamines may be used. For example, low molecular weight compounds having a molecular weight of less than 300 and / or molecular weights of 300 or more, preferably 500 The above-mentioned polyamines high molecular weight body is mentioned.

Specific examples of low molecular weight polyamines include aliphatic polyamines, aromatic polyamines, and heterocyclic polyamines. Preferred specific examples thereof include aliphatic polyamines such as ethylene diamine, hexamethylene diamine, diethylene triamine, triethylene tetramine, guanidine and the like; aromatic polyamines such as phenylene diamine; and heterocyclic polyamines such as piperazine and N-aminoethyl piperazine Etc.

Specific examples of polyamine polymers include amino group-containing polymers, and preferred specific examples thereof include, for example, polyethyleneimine, polytetramethyleneimine, polyvinylamine, polyallylamine, polydiallylamine, polydimethylallylamine, dicyandiamide-formalin Examples thereof include condensates and dicyandiamide-alkylene (polyamine) condensates. These may be used alone or in any combination of two or more compounds. In view of availability and economy, use of polyethylene imine (PEI), polyallylamine and polydiallylamine is preferred.

The molecular weight of these polyamines is not particularly limited, and the average molecular weight is preferably in the range of 50 to 200,000, more preferably in the range of 100 to 180,000, still more preferably in the range of 200 to 100,000, still more preferably 500 to 500 It is in the range of 50000, particularly preferably in the range of 1000 to 30000, most preferably in the range of 1500 to 25000. The content of the polyamines in the coating solution for a non-aqueous electrolyte battery separator is not particularly limited, but generally, 100 parts by mass of the neutralized salt (solid content) of the α-olefin-maleic acid copolymer is used. The amount is usually 0.01 parts by mass or more, preferably 0.02 parts by mass or more, preferably 0.05 to 30 parts by mass, more preferably 0.3 to 10 parts by mass, and further more Preferably it is in the range of 0.5 to 6 parts by weight, most preferably in the range of 0.6 to 5 parts by weight. If content of polyamines is the range of 0.05 mass part-30 mass parts, since it is easy to adjust the viscosity of the coating liquid obtained to a desired range, it is preferable. Moreover, when there is too much content of polyamines, it tends to lead to an increase in a resistance component, and when too little, there exists a tendency which can not provide sufficient adhesiveness and the coating property to a separator base material.

In one embodiment of the present invention, polyamines can be added simultaneously by reacting an α-olefin-maleic acid copolymer and a basic substance containing a monovalent metal, or an α-olefin-maleic acid co-product can be added. It can also be added after reacting the polymer and the basic substance containing a monovalent metal. The temperature for promoting the crosslinking reaction is not particularly limited, but the crosslinking reaction proceeds rapidly by heating generally at 20 ° C. or more, preferably 30 ° C. or more. The time required for the crosslinking reaction convergence is not limited because it depends on the temperature, but the crosslinking reaction usually converges in about 0.1 hour to 2 months.

In one embodiment of the present invention, the thermal decomposition temperature of the mixture of the neutralized salt of the copolymer and the polyamine (or the solid content of the separator coating liquid) is preferably 150 ° C. or higher, and is 200 ° C. or higher. Is more preferred. Thus, it is considered that the battery maintains its shape even when the thermal runaway occurs, and the short circuit is suppressed. If the thermal decomposition temperature does not reach a predetermined temperature, the shape of the separator can not be maintained at the time of thermal runaway, and the battery may be easily short-circuited. The thermal decomposition temperature of the mixture (solid content of the separator coating liquid) is usually 380 ° C. or less.

Although the measuring method of thermal decomposition temperature is not specifically limited, For example, it can measure by the method etc. which are described in the below-mentioned Example.

In one embodiment of the present invention, the separator coating liquid or the slurry composition preferably further contains an aqueous emulsion. The aqueous emulsion refers to an emulsion in which particulate matter is dispersed in an aqueous solvent. The particulate matter is preferably one having mutual binding property to the active material and / or current collector described later (particulate binder). That is, the coating liquid or slurry composition for a non-aqueous electrolyte battery separator according to one aspect of the present invention is preferably an α-olefin-maleic acid copolymerized with an α-olefin and a maleic acid as a binder composition. It contains a neutralized salt of an acid copolymer, a polyamine, and a particulate matter, preferably a particulate binder. As a suitable particulate-form binder, the dispersion-type binder which is excellent in the dispersibility to a dispersion medium is mentioned. As such a particulate substance, preferably as a dispersion type binder, for example, a fluorine based polymer, an olefin based polymer, a diene based polymer, an acrylic based polymer, a vinyl aromatic based polymer such as polystyrene, Polymer compounds such as polyimides, polyamides, polyurethane polymers and the like can be mentioned. The particulate material is preferably at least one selected from the group consisting of an olefin polymer, a diene polymer, an acrylic polymer, and a vinyl aromatic polymer.

The olefin polymer is a homopolymer of an olefin compound or a copolymer of two or more components. As an olefin compound, ethylene, propylene, 1-butene, 2-butene, isobutylene, isobutene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-hexene, 1-heptene, 1 -Octene, 1-nonene etc. are mentioned. The olefin polymer may be copolymerized with unsaturated carboxylic acid or its anhydride, (meth) acrylic esters, maleic esters, vinyl esters, (meth) acrylamides, etc. as other constituent components. Good. The olefin polymer is preferably an ethylene polymer or a propylene polymer containing ethylene or propylene.

The diene polymer is a homopolymer of conjugated diene or a random or block copolymer containing vinyl aromatic and conjugated diene, or a hydrogenated product thereof. Specific examples of the diene polymer include conjugated diene homopolymers such as polybutadiene and polyisoprene; aromatic vinyl / conjugated diene copolymers such as styrene / butadiene copolymer (SBR) that may be carboxy-modified; Examples thereof include vinyl cyanide / conjugated diene copolymers such as acrylonitrile / butadiene copolymer (NBR); hydrogenated products of the aforementioned conjugated diene polymers or copolymers such as hydrogenated SBR and hydrogenated NBR.

The acrylic polymer is a homopolymer of acrylic acid ester or methacrylic acid ester or a copolymer with a monomer copolymerizable therewith. Examples of the copolymerizable monomers include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid and fumaric acid; two or more such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate and trimethylolpropane triacrylate Carboxylic esters having a carbon-carbon double bond; styrene, chlorostyrene, vinyltoluene, t-butylstyrene, vinylbenzoic acid, methylvinylbenzoate, vinylnaphthalene, chloromethylstyrene, hydroxymethylstyrene, α-methylstyrene Styrene-based monomers such as divinylbenzene; amide-based monomers such as acrylamide, N-methylol acrylamide, and acrylamido-2-methylpropane sulfonic acid; α, β-nons such as acrylonitrile and methacrylonitrile Diluted nitrile compounds; Diene monomers such as butadiene and isoprene; Halogen atom-containing monomers such as vinyl chloride and vinylidene chloride; Vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl benzoate; Methyl vinyl ether Vinyl ethers such as ethyl vinyl ether and butyl vinyl ether; vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, hexyl vinyl ketone and isopropenyl vinyl ketone; heterocyclic rings such as N-vinyl pyrrolidone, vinyl pyridine and vinyl imidazole Containing vinyl compounds; and hydroxyalkyl group-containing compounds such as β-hydroxyethyl acrylate and β-hydroxyethyl methacrylate.

Among these, it is preferable to use an olefin polymer, an acrylic polymer, a conjugated diene polymer, a copolymer or a hydrogenated product thereof, and a propylene polymer, a homopolymer of (meth) acrylic acid ester or It is more preferable to use a copolymer, SBR, NBR, and hydrogenated SBR. These aqueous emulsions are commercially available, for example, as TRD 2001 (SBR emulsion, manufactured by JSR), Chemipal X800-H (polypropylene emulsion, manufactured by Mitsui Chemicals).

In the particulate substance (or particulate binder), “particulate” refers to polymer particles obtained by emulsion polymerization of the monomers that mainly constitute the above-mentioned polymer, or emulsification after polymerization, It refers to the properties of the emulsified polymer particles. There is no restriction | limiting in particular as an emulsion polymerization method, The conventionally well-known arbitrary emulsion polymerization method is employ | adopted.

The average particle diameter of the aqueous emulsion in which the particulate matter is dispersed is preferably 0.01 to 0.5 μm, and more preferably 0.01 to 0.3 μm. If the average particle size is less than 0.01 μm, the viscosity of the coating liquid or slurry may increase to cause deterioration of the coating property, and the emulsion may be coagulated to reduce the adhesion between the separator and the heat-resistant layer. There is something to do. When the average particle size exceeds 0.5 μm, the dispersibility of the coating film or the binder on the separator may decrease, and the adhesion may decrease. Also, Li dendrite is generated along with the local increase in resistance. Can increase the risk of short circuiting. In addition, an average particle diameter refers to the volume average particle diameter measured by the laser scattering method here.

The content of the particulate matter (solid content) in the aqueous emulsion is preferably 10 to 60 parts by mass, and more preferably 20 to 50 parts by mass with respect to 100 parts by mass of the aqueous emulsion.

The solid content (particulate matter) content of the aqueous emulsion in the separator coating liquid is usually 0.01 to 50 parts by mass with respect to 100 parts by mass of the neutralized salt of the α-olefin-maleic acid copolymer. The amount is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and still more preferably 0.1 to 10 parts by mass.

Also, in one embodiment of the present invention, a protective colloid may be added to the aqueous emulsion in order to stabilize the above-mentioned polymer particles. Here, the protective colloid refers to a hydrocolloid added for the purpose of stabilizing the hydrophobic colloid to the electrolyte. It is considered that this stabilization action is due to the fact that the hydrocolloid particles enclose the hydrocolloid particles and the nature of the hydrocolloid appears as a whole. Examples of protective colloids include polyvinyl alcohol, modified polyvinyl alcohol; water-soluble cellulose derivatives such as methyl cellulose, ethyl cellulose, hydroxymethyl cellulose and hydroxypropyl cellulose; water-soluble salts of (meth) acrylate-unsaturated carboxylic acid copolymers; styrene Maleic anhydride copolymer salt, maleinized polybutadiene salt, naphthalene sulfonate, polyacrylate and the like. These protective colloids can be used alone or in combination of two or more. Among these, in the embodiment, as the protective colloid, it is preferable to use a water-soluble salt of (meth) acrylic acid ester-unsaturated carboxylic acid copolymer and / or polyvinyl alcohol, and (meth) acrylic acid ester It is extremely preferable to use a water-soluble salt of an unsaturated carboxylic acid copolymer.

In one embodiment of the present invention, the solid content (particulate matter) of the aqueous emulsion in the separator coating liquid, in particular the content of the particulate binder, is not particularly limited, but α-olefin-maleic acids The amount is preferably in the range of 1 to 50 parts by mass, more preferably 5 to 30 parts by mass, and still more preferably 7 to 20 parts by mass with respect to 100 parts by mass of the copolymer (solid content). If the amount is too large, the adhesion is lowered, which is not preferable. On the other hand, too small addition amount is not preferable because sufficient binding property can not be provided.

In one embodiment of the present invention, the separator coating liquid further contains, if necessary, additives such as inorganic particles, dispersants such as surfactants, thickeners, wetting agents and antifoaming agents. It is also good.

As the inorganic particles, any of synthetic products and natural products can be used without particular limitation. Examples of inorganic particles include aluminas such as gibbsite, bayerite, boehmite and corundum, silica, titania, zirconia, magnesia, ceria, yttria, oxide ceramics such as zinc oxide and iron oxide, silicon nitride, titanium nitride and nitrided Boron and other nitride-based ceramics, silicon carbide, calcium carbonate, aluminum sulfate, aluminum hydroxide, magnesium hydroxide, potassium titanate, talc, synthetic kaolinite, kaolin clay, kaolinite, fly bondite, steven sites, dickite, nacrite , Halloysite, pyrophyllite, odnightite, montmorillonite, beidellite, nontronite, volkon scoreite, saponite, hectorite, fluorine hectorite, sauconite, swin Rudite, vermiculite, fluorine vermiculite, vercerin, sericite, amesite, keriaite, freiponite, blindlyite, bentonite, zeolite, biotite, phlogopite, fluorine phlogopite, iron mica, yeast nightite, teniolite, siderophyllite Tetra-ferrite mica, phlogopite, fluorine tetra silicon mica, polylithionite, muscovite, ceradonite, iron ceradonite, iron aluminoceradonite, aluminoseladonite, abrasive part mica, soda mica, soda mica, Kinoshita, vitreous mica, Ananda stone, pearlite, clinochlora, chamosite, pennantite, nimite, bailicroa, dombasite, kukeasite, sudoite, hydrotalcite, calcium silicate, magnesium silicate, aluminum silicate, diatomaceous earth and kerosene Such as sand, and ceramics and glass fibers. These inorganic particles may be used alone or in combination of two or more.

When the said separator coating liquid contains an inorganic particle, the quantity of the inorganic particle of a separator coating liquid is 10-10000 mass normally with respect to 1 mass part of neutralization salts of the said (alpha) -olefin-maleic acid copolymer. It is preferably part, more preferably 20 to 1000 parts by mass, and still more preferably 25 to 500 parts by mass.

Moreover, in one embodiment of the present invention, the separator coating liquid is preferably added to the polymer composition (preferably the binder composition) that should preferably constitute the coating film, and further, among the above-mentioned inorganic particles, a metal oxide and The slurry composition may contain at least one of metal salts. Such metal oxides and metal salts are non-water soluble and include, for example, metal oxides of divalent to tetravalent metals or metal salts of divalent to tetravalent metals. Specifically, metal carbonates such as calcium carbonate, magnesium carbonate and barium carbonate; metal sulfates such as barium sulfate; metal oxides such as magnesium oxide, zinc oxide, alumina, silica and titanium oxide; talc, clay, mica And clay minerals such as montmorillonite, and barium titanate. These may be used alone or in combination of two or more.

Among these, alumina, barium sulfate or barium titanate is preferable, and alumina is particularly preferable, from the viewpoint of being chemically inactive when the laminated porous substrate is incorporated into a battery as a battery separator. As the alumina, α-alumina, γ-alumina, θ-alumina, κ-alumina, pseudo-boehmite and the like can be mentioned, but α-alumina is preferable from the viewpoint of being chemically inactive.

Even when the separator coating liquid (or slurry composition) of the present invention further contains at least one of a metal oxide and a metal salt, the separator coating liquid (or slurry composition) is at least one selected from water insoluble metal oxides and metal salts. Viscosity stability when slurrying metal components is improved, and when a coated layer is formed on a porous substrate using the obtained slurry, a laminated porous substrate having excellent surface smoothness is obtained. be able to. The laminated porous substrate can be suitably used as a separator for a non-aqueous electrolyte secondary battery. Here, in the separator for a non-aqueous electrolyte secondary battery, the coating layer containing the above-mentioned polymer composition (preferably a binder composition) and at least one of a metal oxide and a metal salt is a porous substrate. It may be bound to at least one side. The above-mentioned polymer composition (preferably a binder composition) is usually dissolved or dispersed in water to exhibit a function, and is one or more metals selected from water-insoluble metal oxides and metal salts. It has a function as a viscosity modifier to adjust the viscosity of the slurry containing the components and a function as a dispersant to homogeneously disperse the active material in the solvent, and it binds homogeneously and strongly on the porous substrate Can.

The metal oxide and / or metal salt used in the above embodiment preferably has an average particle diameter of 1.0 μm or more and 3 μm or less. When the metal oxide and / or metal salt has an average particle size of 1.0 μm or more, the particle size distribution can be controlled without aggregation of the metal oxide and / or metal salt in the slurry, and packing Improves the quality. As a result, the adhesiveness and shape stability at the time of heating of a coating layer improve. The average particle size and volume distribution less than 1.0 μm can be obtained, for example, by adding a ceramic slurry to water using a laser scattering particle size distribution analyzer (Microtrack Bell (“MT3300EXII” manufactured by Nikkiso Co., Ltd.)) at a flow rate of 45%. The particle diameter (D50) at 50% of the volume-based integrated fraction measured within 10 minutes after circulating for 3 minutes can be obtained as the volume-based integrated amount of particles less than 1.0 μm in particle diameter.

Examples of dispersants such as surfactants include anionic surfactants such as sulfate ester type, phosphate ester type, carboxylic acid type and sulfonic acid type, and cationic surfactants such as quaternary ammonium salt type and amidoamine type Agent, amphoteric surfactant such as alkyl betaine type, amido betaine type, amine oxide type, non-ionic surfactant such as ether type, fatty acid ester type, alkyl glucoxide, polyacrylic acid, polyacrylate, polysulfonic acid Various surfactants such as salts, polynaphthalene sulfonates, polyvinyl pyrrolidone, and high molecular type surfactants such as cellulose type can be used. These are used singly or in combination of two or more for the purpose of preventing aggregation of the fillers. The dispersant is not limited as long as the same effect as described above can be obtained.

When the said separator coating liquid contains a dispersing agent, the quantity of the dispersing agent in a separator coating liquid is normally 0.01 with respect to 100 mass parts of neutralization salts of the said (alpha) -olefin-maleic acid copolymer. The amount is preferably 10 parts by mass, more preferably 0.1 to 5 parts by mass.

Examples of the thickener include synthetic polymers such as polyethylene glycol, urethane-modified polyether, polyacrylic acid, polyvinyl alcohol, vinyl methyl ether-maleic anhydride copolymer, carbomethoxy cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and the like. Cellulose derivatives, natural polysaccharides such as xanthan gum, dayutan gum, welan gum, gellan gum, guar gum, carrageenan gum, starches such as dextrin and pregelatinized starch. These may be used alone or in combination of two or more. The thickener is not limited to the above as long as the same effects as those described above can be obtained.

When the said separator coating liquid contains a thickener, the quantity of the thickener in a separator coating liquid is usually 0 with respect to 100 mass parts of neutralization salts of the said (alpha) -olefin-maleic acids copolymer. It is preferably from 0.1 to 10 parts by mass, more preferably from 0.1 to 5 parts by mass.

As the wetting agent, for example, an aliphatic polyether type nonionic surfactant, a polyoxyalkylene type nonionic surfactant, a modified silicone, a modified polyether, a dimethylsiloxane polyoxyalkylene copolymer can be used. These may be used alone or in combinations of two or more. The wetting agent is not limited as long as the same effect as described above can be obtained.

When the separator coating liquid contains a wetting agent, the amount of the wetting agent in the separator coating liquid is usually 0.01, based on 100 parts by mass of the neutralized salt of the α-olefin-maleic acid copolymer. The amount is preferably 10 parts by mass, more preferably 0.1 to 5 parts by mass.

As an antifoamer, various mineral antifoamers, such as a mineral oil type, a silicone type, an acryl type, and a polyether type, can be used, for example. These may be used alone or in combinations of two or more. The antifoaming agent is not limited to the above as long as the same effect as described above can be obtained.

When the said separator coating liquid contains an antifoamer, the quantity of the antifoamer in the resin composition for separators is usually, With respect to 100 mass parts of neutralization salts of the above-mentioned alpha-olefin-maleic acid copolymer, The amount is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass.

The coating solution for a non-aqueous electrolyte battery of the present invention contains a solvent. As a solvent which can be used, for example, water, alcohols such as methanol, ethanol, propanol and 2-propanol, cyclic ethers such as tetrahydrofuran and 1,4-dioxane, N, N-dimethyl formamide, N, N- Amides such as dimethylacetamide, cyclic amides such as N-methyl pyrrolidone and N-ethyl pyrrolidone, and sulfoxides such as dimethyl sulfoxide are exemplified. Among these, the use of water is preferred from the viewpoint of safety and solubility.

In the embodiment of the present invention, when water is used as a solvent for the separator coating liquid, the following organic solvents may be used in combination within a range of preferably 20% by mass or less of the whole solvent. As such an organic solvent, one having a boiling point of 100 ° C. or more and 300 ° C. or less at normal pressure is preferable, for example, hydrocarbons such as n-dodecane; alcohols such as 2-ethyl-1-hexanol, 1-nonanol Esters such as γ-butyrolactone and methyl lactate; amides such as N-methylpyrrolidone, N, N-dimethylacetamide and dimethylformamide; and organic dispersion media such as sulfoxide and sulfones such as dimethylsulfoxide and sulfolane.

The amount of the solvent in the separator coating liquid is usually preferably 50 to 250 parts by mass, more preferably 70 to 200 parts by mass with respect to 10 parts by mass of the neutralized salt of the α-olefin-maleic acid copolymer. It is a mass part. If the amount of the α-olefin-maleic acid copolymer is too small, the viscosity is lowered and the coatability is lowered, the surface of the separator substrate can not be sufficiently covered, and good battery characteristics such as shorting occur. It may not be expressed. On the contrary, if the amount of the α-olefin-maleic acid copolymer is too large, the viscosity becomes high, the coatability may be reduced, the surface of the separator substrate may not be sufficiently coated, and the electric resistance is also increased. Discharge capacity may be reduced.

The separator coating liquid (or slurry composition) of the present invention mixes and disperses the polymer composition (preferably a binder composition) to be included in the coating liquid or slurry composition and the solvent, and then, if necessary, It can manufacture by adding and mixing additives, such as dispersing agents, such as metal oxides or metal salts, inorganic particles and surfactants, thickeners, wetting agents and antifoaming agents. Although the method of obtaining a coating liquid or a slurry composition is not specifically limited, A mechanical stirring method, an ultrasonic dispersion method, a high pressure dispersion method, a media dispersion method etc. can be mentioned. Above all, the inorganic filler can be highly dispersed, and the binder resin of the present embodiment, which is water-soluble with the metal oxide and / or metal salt that is water-insoluble in a short time, can be made to blend with each other. Mechanical agitation is preferred in that respect. The order of mixing is not particularly limited, but care should be taken so that the coating liquid or the slurry composition does not have an obstacle such as generation of a precipitate.

Furthermore, the present invention also relates to a non-aqueous electrolyte battery separator comprising a separator substrate and a separator coating layer formed on the substrate from the coating solution for the separator.

In one embodiment of the present invention, the non-aqueous electrolyte battery separator is formed by applying the above-described separator coating liquid to a separator substrate to form a separator coating layer (coating layer) on the surface of the separator substrate. You can get it. There is no particular limitation on the method of coating the separator coating liquid on the separator substrate, and, for example, the doctor blade method, dip method, reverse roll method, direct roll method, gravure method, extrusion method, immersion method, brush coating method, etc. Method is mentioned.

The surface of the separator base material is not particularly limited as coating weight of the layer coated with the separator coating solution is preferably 1.0 ~ 30g / ^{m 2,} further 4.0 ~ 20g / ^{m 2} is more preferable. When the adhesion amount of the covering layer is less than 1.0 g / m ² , the surface of the separator substrate can not be sufficiently covered, the pore diameter becomes large, and good battery characteristics do not appear, such as occurrence of short circuit. There is. On the other hand, if the adhesion amount of the coated layer exceeds 30 g / m ² , it may be difficult to thin the separator.

The non-aqueous electrolyte battery separator of the present invention can prevent short circuiting of the electrodes in the non-aqueous electrolyte battery without interfering with charging and discharging of the battery.

In the embodiment, as the separator substrate, for example, a film-like, paper-like, non-woven porous substrate, particularly a porous film or non-woven fabric made of an organic material having fine pores can be used.

More specifically, as a constituent material of the separator substrate, polyethylene terephthalate, polybutylene terephthalate and derivatives thereof, polyester such as aromatic polyester, wholly aromatic polyester, polyolefin, acrylic, polyacetal, polycarbonate, aliphatic polyketone, Aromatic polyketone, aliphatic polyamide, aromatic polyamide, wholly aromatic polyamide, polyimide, polyamideimide, polyphenylene sulfide, polybenzimidazole, polyetheretherketone, polyethersulfone, poly (para-phenylenebenzobisthiazole), poly ( Para-phenylene-2,6-benzobisoxazole), polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, polyurethane and poly salt Such fibers and cellulosic fibers made of a resin such as vinyl and the like. As a separator base material, you may contain combining 2 or more types of these structural materials.

In one embodiment of the present invention, when the non-aqueous electrolyte battery separator is provided with a porous substrate and a covering layer containing the binder composition and the metal oxide and / or metal salt on at least one side thereof, metal oxidation Since the smoothness of the coating layer formed from the slurry containing the metal and / or the metal salt greatly affects the cell performance, it is preferably in the form of a film. As the resin constituting the porous substrate, the melting point (softening point) of the resin is preferably 70 to 150 ° C., more preferably 80 to 140 ° C., from the viewpoint of the shutdown function in which the pores are clogged when the charge / discharge reaction is abnormal. And most preferably in the range of 100.degree. To 130.degree.

As a preferable porous base material, the polyolefin microporous film whose resin which comprises from a viewpoint of heat resistance and air permeability is polyolefin resin is mentioned. In particular, from the viewpoint of electrical insulation, ion permeability, or pore blocking effect, a polyethylene microporous membrane in which the resin constituting is a polyethylene resin or a polypropylene microporous membrane in which the constituting resin is a polypropylene resin is preferable.

The weight-average molecular weight of the polyolefin resin used as the porous substrate is in view of process workability and mechanical strength (for example, tensile strength, elastic modulus, elongation, puncture strength) that withstands various external pressures generated during winding with the electrode. Therefore, it is preferably at least 300,000, more preferably at least 400,000, and most preferably at least 500,000. Also, from the viewpoint of availability, the weight average molecular weight is preferably 1,000,000 or less. In addition, when using polyolefin resin, it is preferable that 50 mass% or more of the polyolefin component which has a weight average molecular weight of the said range is contained, and it is more preferable that 60 mass% or more is contained. If the content is less than the above range, the melt viscosity is low, and the mechanical properties drop when the temperature is raised above the pore blockage temperature, and melting occurs by winding pressure or burrs at the electrode end even near the pore blockage temperature. Membrane rupture may occur.

Although the layer structure of the porous substrate is not particularly limited, a layer structure according to the purpose can be freely provided by the production method. As a method for producing a porous substrate, there are a foaming method, a phase separation method, a solution recrystallization method, a stretched pore method, a powder sintering method and the like. Separation methods are preferred.

The air resistance (JIS-P8117) of the porous substrate is preferably 500 seconds / 100 ccAir or less, more preferably 400 seconds / 100 ccAir or less, further preferably 300 seconds / 100 ccAir or less, and preferably 50 seconds. / 100 ccAir or more, more preferably 70 seconds / 100 cc Air or more, still more preferably 100 seconds / 100 cc Air or more.

The thickness of the separator substrate is usually 0.5 μm or more, preferably 1 μm or more, and usually 40 μm or less, preferably 30 μm or less. The resistance by the separator base material in a battery will become small as it is this range, and it is excellent in the workability at the time of battery manufacture.

The method for drying the solvent such as water contained in the separator coating liquid after applying it to the separator substrate is not particularly limited. For example, dry drying with warm air, hot air, low humidity air; vacuum drying; infrared rays, far infrared rays, Radiation drying such as electron beam may be mentioned. As for the drying conditions, the solvent is removed as quickly as possible within the range of the drying speed at which the layer coated with the separator coating liquid is cracked due to stress concentration or the layer coated with the separator coating liquid does not peel from the separator You should adjust as you can.

As a drying temperature, 100 degrees C or less is preferable, More preferably, it is 90 degrees C or less, More preferably, it is 80 degrees C or less. The heating and drying time is preferably several seconds to several minutes. When the heating and drying temperature is higher than 100 ° C., the shutdown function of the porous substrate may be developed to deteriorate the battery characteristics.

In one embodiment of the present invention, a nonaqueous electrolyte battery separator preferably has a basis weight is 10.0 ~ 50.0g / ^{m 2,} it is 15.0 ~ 40.0g / ^{m 2} More preferable. The thickness of the separator is preferably 10.0 to 50.0 μm, and more preferably 15.0 to 40.0 μm. The density of the separator is preferably 0.4 to 1.2 g / cm ³ , and more preferably 0.6 to 1.0 g / cm ³ .

In the above embodiment, after coating and drying the separator coating liquid, the separator coating layer is smoothed by rolling or calendering for the purpose of controlling the surface flatness and thickness of the coating layer (coating layer). It is also good.

Furthermore, the present invention also relates to a non-aqueous electrolyte battery comprising the above-mentioned separator, a negative electrode, a positive electrode, and an electrolytic solution.

In the embodiment of the present invention, the current collector used for the negative electrode and the positive electrode of the non-aqueous electrolyte battery is not particularly limited as long as it is made of a conductive material, and for example, iron, copper, aluminum, nickel, stainless steel Metal materials such as steel, titanium, tantalum, gold and platinum can be used. One of these may be used alone, or two or more of them may be used in combination at an arbitrary ratio.

In the said embodiment, the material normally used by a non-aqueous electrolyte battery can be used as a negative electrode. For example, Li, Na, C, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, At least one or more elements selected from the group consisting of Mo, Pd, Ag, Cd, In, Sn, Sb, W, Pb and Bi, alloys using these elements, oxides, chalcogenides or halides, etc. used. Furthermore, for example, carbonaceous materials such as amorphous carbon, graphite, natural graphite, mesocarbon microbeads (MCMB), pitch carbon fibers, etc .; conductive polymers such as polyacene; complex metal oxides represented by SiOx, SnOx, LiTiOx And other metal oxides and lithium metals such as lithium metal and lithium alloy; and metal compounds such as TiS ₂ and LiTiS ₂ .

In the said embodiment, a thickener can be further added as needed. The thickener to be added is not particularly limited, and various alcohols, in particular, polyvinyl alcohol and its modified products, celluloses, polysaccharides such as starch, etc. can be used.

The amount of the thickener used is preferably about 0.1 to 4 parts by mass, more preferably 0.3 to 3 parts by mass, and still more preferably 0.5 to 2 parts by mass with respect to 100 parts of the negative electrode active material. It is. If the amount of the thickener is excessively small, the viscosity of the slurry composition containing the negative electrode active material and the solvent (hereinafter, also simply referred to as a negative electrode slurry composition) may be too low and the thickness of the mixed layer may be reduced. An excessive amount of thickener may reduce the discharge capacity.

Moreover, as a conductive support agent mix | blended as needed with the slurry composition for negative electrodes, a metal powder, a conductive polymer, acetylene black etc. are mentioned, for example. The amount of the conductive additive used is usually preferably 0.5 to 10 parts by mass, and more preferably 1 to 7 parts by mass with respect to 100 parts by mass of the negative electrode active material.

The negative electrode is a negative electrode active material as described above, a conductive additive, and a binder such as SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylidene fluoride and the like, and a boiling point of 100 or more at water under normal pressure. The slurry for the negative electrode prepared by mixing in a solvent or the like at a temperature of 300 ° C. to 300 ° C. is applied to the current collector as described above, for example, a negative electrode current collector such as copper, and dried. it can.

In the said embodiment, the positive electrode normally used for a non-aqueous electrolyte battery is used without a restriction | limiting in particular as a positive electrode. For example, as a positive electrode active material, TiS ₂ , TiS ₃ , amorphous MoS ₃ , Cu ₂ V ₂ O ₃ , amorphous V ₂ O-P ₂ O ₅ , MoO ₃ , V ₂ O 5, V ₆ O ₁₃ And transition metal oxides such as LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , and lithium-containing composite metal oxides such as LiMn ₂ O ₄ are used. In addition, a positive electrode active material, a conductive auxiliary agent similar to that of the above negative electrode, a thickener, and a binder such as SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylidene fluoride, etc. The slurry composition for a positive electrode prepared by mixing in a solvent or the like at 100 ° C. or more and 300 ° C. or less may be applied to a positive electrode current collector such as aluminum, for example, and the solvent may be dried to form a positive electrode.

The method for applying each of the electrode slurry compositions to the current collector is not particularly limited. For example, methods such as a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, an immersion method, and a brush coating method can be mentioned. The application amount is also not particularly limited, but the thickness of the mixed layer containing the active material, the conductive aid, the binder and the thickener, which is formed after the solvent or dispersion medium is removed by a method such as drying, is preferably 0.005 to An amount of 5 mm, more preferably 0.01 to 2 mm is generally used.

The drying method of the solvent such as water contained in the slurry composition for electrodes is not particularly limited. For example, through-air drying with warm air, hot air, low humidity air; vacuum drying; irradiation drying of infrared rays, far infrared rays, electron beam, etc. It can be mentioned. The drying conditions may be adjusted so that the solvent can be removed as quickly as possible within the range of a drying rate at which the active material layer is not cracked due to stress concentration or the active material layer does not peel from the current collector. Furthermore, in order to increase the density of the active material of the electrode, it is effective to press the dried current collector. Examples of the pressing method include methods such as a die press and a roll press.

Moreover, the electrolyte which dissolved the electrolyte in the solvent can be used for the non-aqueous electrolyte battery of the said embodiment. The electrolytic solution may be liquid or gel as long as it is used in a normal non-aqueous electrolyte battery, and an electrolyte that exhibits the function as a battery may be appropriately selected according to the types of the negative electrode active material and the positive electrode active material. Good. Specific electrolytes, for example, conventionally known lithium salt are both available _{_{_{LiClO 4, LiBF 6, LiPF 6}}} , LiCF 3 SO 3, LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiB 10 Cl 10, LiAlC _{_{_{l4, LiCl, LiBr, LiB (}}} C 2 H 5) 4, CF 3 SO 3 Li, CH 3 SO 3 Li, LiCF 3 SO 3, LiC 4 F 9 SO 3, Li (CF 3 SO 2) 2 N, lower Examples thereof include lithium aliphatic carboxylic acid.

The solvent (electrolyte solution solvent) for dissolving such an electrolyte is not particularly limited. Specific examples thereof include carbonates such as propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate and diethyl carbonate; lactones such as γ-butyl lactone; trimethoxymethane, 1,2-dimethoxyethane, diethyl ether, 2-ethoxy Ethers such as ethane, tetrahydrofuran, 2-methyltetrahydrofuran; sulfoxides such as dimethyl sulfoxide; oxolanes such as 1,3-dioxolane and 4-methyl-1,3-dioxolane; nitrogen-containing compounds such as acetonitrile and nitromethane; Organic acid esters such as methyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, and ethyl propionate; inorganic acids such as triethyl phosphate, dimethyl carbonate and diethyl carbonate Stils; diglymes; triglymes; sulfolanes; oxazolidinones such as 3-methyl-2-oxazolidinone; sultones such as 1,3-propane sultone, 1,4-butane sultone, naphtha sultone, etc. Or in combination of two or more. When a gel electrolyte solution is used, a nitrile polymer, an acrylic polymer, a fluorine polymer, an alkylene oxide polymer or the like can be added as a gelling agent.

Although there is no limitation in particular as a method of manufacturing the nonaqueous electrolyte battery of the above-mentioned embodiment, the following manufacturing method is illustrated, for example. That is, the negative electrode and the positive electrode are stacked through the separator of this embodiment described above, wound or folded according to the battery shape, and placed in a battery container, and an electrolytic solution is injected and sealed. The shape of the battery may be any of known coin type, button type, sheet type, cylindrical type, square type, flat type and the like.

The non-aqueous electrolyte battery of the embodiment is a battery in which internal short circuiting and resistance increase are unlikely to occur, and is useful for various applications. For example, it is also useful as a battery used for portable terminals that are required to be smaller in size, thinner, lighter, and higher in performance, and also used in large devices such as electric vehicles that require high safety. Very useful.

Examples of the present invention will be described below, but the present invention is not limited thereto.

Example 1
<Preparation of Coating Liquid for Separator>
Water-soluble lithium-modified isobutene-maleic anhydride copolymer (average molecular weight 325,000, degree of neutralization 0) as a neutralized salt of α-olefin-maleic acid copolymer obtained by copolymerizing α-olefins and maleic acid .5, ring opening ratio 96%, molar ratio (A) / (B) = 1/1 of unit (A) based on α-olefins and unit (B) based on maleic acid (25) (0.16 mol) A 10% by weight aqueous solution was prepared and used in the following test. The degree of neutralization was adjusted by adding 1.0 equivalent (0.160 mol) of lithium hydroxide to the maleic acid unit in the maleic acid copolymer. This lithium-modified isobutene-maleic anhydride copolymer (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%) 10% by mass aqueous solution and polyethyleneimine (PEI, manufactured by Wako Pure Chemical Industries, Ltd., average It mixed so that it might become a mass ratio of 99.9: 0.1 with 10 mass% aqueous solution of molecular weight 10000. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating.
An aqueous solution containing a neutralized salt of the α-olefin-maleic acid copolymer thus obtained and a polyamine is diluted with water as a solvent to obtain a coating liquid having a solid content concentration of 5% by mass.

<Preparation of coated separator>
A polyvinyl alcohol-based fiber (27 cm × 25 cm, VPB 033, manufactured by Kuraray) was immersed in the coating liquid. Using an experimental manual mangle (manufactured by Kumagaya Riki Kogyo Co., Ltd.), the separator coated with the diluted solution of the separator base material surface coating solution was subjected to an expression treatment and dried at room temperature for 12 hours. The sheet after drying was pressed by a heat press apparatus (manufactured by Furukawa Seisakusho), and the thickness was adjusted to 20 μm (roll temperature, room temperature, speed 1 m / min, linear pressure 100 hg / cm). The adhesion amount was 2.1 g / m ² .

<Preparation of Slurry for Negative Electrode>
The slurry for the electrode was a solid of 48.3 mass% aqueous dispersion of styrene-butadiene rubber (SBR, TRD 2001, JSR) as a binder relative to 94 parts by mass of natural graphite (DMGS, BYD made) as an active material. 1 part by weight of an aqueous solution of sodium carboxymethylcellulose (CMC, Cellogen BSH-6, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) at 1% by mass as a solid, and as a conductive aid (conductive agent) A solid content of 2 parts by mass of Super-P (manufactured by Timcal) was charged into a dedicated container, and the mixture was kneaded by using a planetary stirrer (ARE-250, manufactured by Shinky). The composition ratio of the active material to the conductive aid and the binder (SBR-CMC) in the slurry is, as a solid content, natural graphite: conductive aid: SBR: CMC = 94: 2: 3: 1.

<Fabrication of negative electrode for battery>
The resulting slurry was applied using a bar coater (T101, manufactured by Matsuo Sangyo Co., Ltd.) so that the coating amount was 8.1 mg / cm ² on the copper foil (CST 8G manufactured by Fukuda Metal Foil Co., Ltd.) of the current collector. After coating and primary drying with a hot air drier (manufactured by Yamato Scientific Co., Ltd.) at 80 ° C. for 30 minutes, rolling treatment was performed using a roll press (manufactured by Takasen). Thereafter, after punching out as a battery electrode (φ 14 mm), a coin battery electrode was manufactured by secondary drying at 120 ° C. for 3 hours under reduced pressure conditions.

<Preparation of Slurry for Positive Electrode>
The slurry for the electrode contains 5 parts by mass of polyvinylidene fluoride (PVDF) as a binder as a solid content, and 92 parts by mass of nickel cobalt manganese (NCM) as an active material, and a conductive aid (conductivity imparting agent) As a solid content, 3 parts by mass of Denka black (powdery, manufactured by Denki Kagaku Kogyo Co., Ltd.) was charged into a dedicated container, and was kneaded by using a planetary stirrer (ARE-250, manufactured by Shinky). In order to adjust the slurry viscosity, water was added at the time of kneading and kneading was performed again to prepare a slurry for electrode coating. The composition ratio of the active material to the binder in the slurry is, as a solid content, graphite powder: conductive auxiliary agent: binder composition = 92: 3: 5.

<Evaluation method: Coating property>
The thickness of arbitrary ten places was measured using the micrometer about the above-mentioned coated separator. The case where the thickness unevenness is in the range of 1 μm in absolute value (the difference between the thickest portion and the thinnest portion is 1 μm or less) is ○, and the thickness unevenness exceeds 1 μm in absolute value is ×.

<Production of positive electrode for battery>
The obtained slurry is coated on a current collector aluminum foil (IN30-H, made by Fuji processed paper) using a film applicator (manufactured by Tester Sangyo Co., Ltd.), and a hot air dryer (manufactured by Yamato Scientific Co., Ltd.) for 30 minutes at 80 ° C. After primary drying in 2.), rolling treatment was carried out using a roll press (manufactured by Takasen). Thereafter, after punching out as a battery electrode (φ 14 mm), a coin battery electrode was manufactured by secondary drying at 120 ° C. for 3 hours under reduced pressure conditions.

<Fabrication of battery>
The coated separator and the battery negative electrode obtained above were transferred to a glove box (manufactured by Miwa Seisakusho) under an argon gas atmosphere. The positive electrode, the negative electrode, and the electrolyte prepared above are ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate solution (1 mol / L LiPF ₆ , EC / DMC / EMC = 1/1/1) of lithium hexafluorophosphate (LiPF ₆ ). A coin battery (2032 type) was produced using 1).

<Evaluation method: charge and discharge characteristic test>
The charge and discharge test was implemented using the commercially available charge and discharge tester (TOSCAT3100, Toyo System make) with respect to the produced coin battery. The coin battery was placed in a 25 ° C. constant temperature bath, and constant current charging at 0.2 C (about 0.5 mA / cm ² ) was performed until the battery voltage became 4.2V. The capacity at this time was taken as the charge capacity (mAh). Next, a constant current discharge of 0.2 C (about 0.5 mA / cm ² ) was performed until the battery voltage was 3 V. The capacity at this time was taken as the discharge capacity (mAh). The difference between the initial discharge capacity and the charge capacity was taken as the irreversible capacity, and the percentage of the discharge capacity / charge capacity was taken as the charge / discharge efficiency. The direct current resistance of the coin battery adopted the resistance value after one charge (full charge state). The above results are shown in Tables 1 and 2 below.
After the above initial charge and discharge, the coin battery was placed in a thermostat bath at 80 ° C., and 50 cycles of constant current charge and discharge at 10 C were performed in a voltage range of 3.0 to 4.2 V. After the test, the percentage of batteries shorted was calculated. The results are shown in Table 1 below.

<Evaluation method: Heat resistance test>
In order to evaluate the heat resistance of the separator coating liquid obtained above, the thermogravimetric measurement is performed using a thermal analyzer (manufactured by Yamato Scientific Co., Ltd.) on the solid content obtained by drying a part of the separator coating liquid. The temperature at which the solid content decreased by 50% or more was defined as the thermal decomposition temperature. The thermal decomposition temperature was 302 ° C. as a result of measurement at a measurement range temperature of 25 ° C. to 600 ° C. and a temperature rising rate of 10 ° C./min. The results are shown in Tables 1 and 2 below.

(Example 2)
Lithium-modified isobutene-maleic anhydride copolymer (average molecular weight 325,000, neutralization degree 0.5, ring opening rate 96%, unit based on α-olefins (A) and unit based on maleic acid (B) Molar ratio (A) / (B) = 1/1 of 99.67: 0.33 of 10% by weight aqueous solution and polyethyleneimine (PEI, Wako Pure Chemical Industries, Ltd., average molecular weight 10000) 10% by weight aqueous solution It mixed so that it might become mass ratio. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating. The obtained aqueous solution was diluted to obtain a coating liquid having a concentration of 5% by mass of the neutralized salt in the aqueous solution.
A coated separator was produced in the same manner as in Example 1 above. Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. The above results are shown in Tables 1 and 2 below. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Example 3)
Lithium-modified isobutene-maleic anhydride copolymer (average molecular weight 325,000, neutralization degree 0.5, ring opening rate 96%, unit based on α-olefins (A) and unit based on maleic acid (B) Molar ratio (A) / (B) = 1/1) The mass ratio of a 10% by mass aqueous solution to a 10% by mass aqueous solution of polyethyleneimine (PEI, manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 10000) is 99: 1 Mixed as. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating. The obtained aqueous solution was diluted to obtain a coating liquid having a solid content concentration of 5% by mass.
A coated separator was produced in the same manner as in Example 1 above. Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. The above results are shown in Tables 1 and 2 below. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Example 4)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 1 (average molecular weight 325,000, degree of neutralization 0.7, ring opening ratio 95%, unit based on α-olefins (A) Molar ratio (A) / (B) = 1/1 of a unit (B) based on a maleic acid compound and a 10% by weight aqueous solution and a 10% by weight aqueous solution of polyethyleneimine (PEI, Wako Pure Chemical Industries, Ltd., average molecular weight 10000) Were mixed so as to give a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating. The obtained aqueous solution was diluted to obtain a coating liquid having a solid content concentration of 5% by mass. A coated separator was produced in the same manner as in Example 1 above. Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. The above results are shown in Tables 1 and 2 below. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Example 5)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 1 (average molecular weight 325,000, neutralization degree 0.4, ring opening ratio 95%, unit based on α-olefins (A) Molar ratio (A) / (B) = 1/1 of a unit (B) based on a maleic acid compound and a 10% by weight aqueous solution and a 10% by weight aqueous solution of polyethyleneimine (PEI, Wako Pure Chemical Industries, Ltd., average molecular weight 10000) Were mixed so as to give a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating. The obtained aqueous solution was diluted to obtain a coating liquid having a solid content concentration of 5% by mass.
A coated separator was produced in the same manner as in Example 1 above. Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. The above results are shown in Tables 1 and 2 below. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Example 6)
Lithium-modified methyl vinyl ether-maleic anhydride copolymer (average molecular weight 630,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A), prepared by the same method as Example 1 And a unit (B) molar ratio based on maleic acid (A) / (B) = 1/1) 10% by mass aqueous solution and polyethyleneimine (PEI, manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 10000) 10% by mass The aqueous solution was mixed at a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating. The obtained aqueous solution was diluted to obtain a coating liquid having a solid content concentration of 5% by mass.
A coated separator was produced in the same manner as in Example 1 above. Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. The above results are shown in Tables 1 and 2 below. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Example 7)
Lithium-modified ethylene-maleic anhydride copolymer prepared by the same method as in Example 1 (average molecular weight 350,000, degree of neutralization 0.5, ring opening ratio 96%, unit based on α-olefins (A) Molar ratio (A) / (B) = 1/1 of a unit (B) based on a maleic acid compound and a 10% by weight aqueous solution and a 10% by weight aqueous solution of polyethyleneimine (PEI, Wako Pure Chemical Industries, Ltd., average molecular weight 10000) Were mixed so as to give a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating. The obtained aqueous solution was diluted to obtain a coating liquid having a solid content concentration of 5% by mass.
A coated separator was produced in the same manner as in Example 1 above. Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. The above results are shown in Tables 1 and 2 below. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Example 8)
Lithium-modified styrene-maleic anhydride copolymer prepared by the same method as in Example 1 (average molecular weight 11,000, neutralization degree 0.5, ring opening ratio 94%, unit based on α-olefins (A) Molar ratio (A) / (B) = 1/1 of a unit (B) based on a maleic acid compound and a 10% by weight aqueous solution and a 10% by weight aqueous solution of polyethyleneimine (PEI, Wako Pure Chemical Industries, Ltd., average molecular weight 10000) Were mixed so as to give a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating. The obtained aqueous solution was diluted to obtain a coating liquid having a solid content concentration of 5% by mass.
A coated separator was produced in the same manner as in Example 1 above. Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. The above results are shown in Tables 1 and 2 below. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Example 9)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 1 (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A) And a unit (B) molar ratio based on maleic acid (A) / (B) = 1/1 99% aqueous solution of 10% by mass aqueous solution of polyallylamine (PAA, Nittobo Medical, average molecular weight 3000) It mixed so that it might become mass ratio of .67: 0.33. The resulting mixture was heated to 90 ° C. and stirred for 1 hour while heating. The obtained aqueous solution was diluted to obtain a coating liquid having a solid content concentration of 5% by mass.
A coated separator was produced in the same manner as in Example 1 above. Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. The above results are shown in Tables 1 and 2 below. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Example 10)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 1 (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A) And a unit (B) molar ratio based on maleic acid (A) / (B) = 1/1 99% aqueous solution of 10% by weight aqueous solution of polydiallylamine (PAS, manufactured by Nittobo Medical, average molecular weight 5000) It mixed so that it might become mass ratio of .67: 0.33. The resulting mixture was heated to 90 ° C. and stirred for 1 hour while heating. The obtained aqueous solution was diluted to obtain a coating liquid having a solid content concentration of 5% by mass.
A coated separator was produced in the same manner as in Example 1 above. Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. The above results are shown in Tables 1 and 2 below. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Comparative example 1)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 1 (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A) And a unit (B) molar ratio based on maleic acid (A) / (B) = 1/1) A coated separator was prepared in the same manner as in Example 1 using a 10% by mass aqueous solution as a coating solution. Further, the solid content of the separator coating liquid was measured by the same method as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Comparative example 2)
Lithium-modified methyl vinyl ether-maleic anhydride copolymer (average molecular weight 630,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A), prepared by the same method as Example 1 Molar ratio (A) / (B) = 1/1 of a unit (B) based on maleic acid group) and a 10% by mass aqueous solution were used as a coating solution, and a coated separator was prepared by the same method as in Example 1 above . Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Comparative example 3)
Lithium-modified styrene-maleic anhydride copolymer prepared by the same method as in Example 1 (average molecular weight 11,000, neutralization degree 0.5, ring opening ratio 94%, unit based on α-olefins (A) And a unit (B) molar ratio based on maleic acid (A) / (B) = 4/1) Using a 10% by mass aqueous solution as a coating solution, a coated separator was produced by the same method as in Example 1 above. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Comparative example 4)
A coated separator was prepared in the same manner as in Example 1 using a 1.0% by mass aqueous solution of CMC-Na as a coating solution as a resin composition for a separator. The adhesion amount was 2.0 g / m ² . Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. Further, the thermal decomposition temperature of the solid content of the separator coating liquid was measured in the same manner as in Example 1 above. The results are shown in Tables 1 and 2 below.

(Example 11)
<Preparation of Separator Coating Liquid>
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 1 (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A) Molar ratio (A) / (B) = 1/1 of a unit (B) based on maleic acid compounds and a 10% by weight aqueous solution and a 10% by weight aqueous solution of polyethyleneimine (PEI, manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 1800) Were mixed so as to give a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating. About the solid content obtained by drying a part of this heating solution, the thermal decomposition temperature was measured similarly to Example 1.
The heating solution obtained above is diluted with water so that the solid content concentration becomes 5% by mass, and then the total amount of lithium-modified isobutene-maleic anhydride copolymer and polyethylene imine is TRD 2001 (SBR, as an aqueous emulsion). The average particle size of polymer particles manufactured by JSR: 200 nm) was mixed so that the solid content was 90:10 mass ratio, to obtain a separator coating liquid (solid content concentration: 5.5 mass%).

<Method for measuring particle size of polymer particles>
The aqueous emulsion is measured using a particle size distribution analyzer (FPAR-1000 _ made by Otsuka Electronics Co., Ltd.) whose measurement principle is based on the dynamic light scattering method, and the value at which the cumulative frequency of the number of particles obtained is 50% is the average of the polymer particles. It was the particle size.

<Preparation of coated separator>
This separator coating liquid was applied onto a polypropylene-based separator substrate (Celgard # 2400, manufactured by Polypore), and dried at room temperature for 12 hours. The sheet after drying was pressed by a heat press apparatus (manufactured by Furukawa Seisakusho), and the thickness was adjusted to 20 μm (roll temperature, room temperature, speed 1 m / min, linear pressure 100 hg / cm). The adhesion amount was 1.9 g / m ² .

<Preparation of Slurry for Negative Electrode>
The slurry for the electrode was a solid component of 48.3 mass% aqueous dispersion of styrene-butadiene rubber (SBR, TRD2001, JSR) as a binder relative to 94 parts by mass of natural graphite (DMGS, BYD) as an active material. 3 parts by mass, and 1 part by mass of a 1% by mass aqueous solution of sodium carboxymethylcellulose (CMC, Cellogen BSH-6, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) as a solid, and Super as a conduction aid (conductivity imparting agent) A solid content of 2 parts by mass of -P (manufactured by Timcal) was charged into a dedicated container, and the mixture was kneaded by using a planetary stirrer (ARE-250, manufactured by Shinky). The composition ratio of the active material to the conductive aid and the binder (SBR-CMC) in the slurry is, as a solid content, natural graphite: conductive aid: SBR: CMC = 94: 2: 3: 1.

<Preparation of Slurry for Positive Electrode>
The slurry for the electrode contains 5 parts by mass of polyvinylidene fluoride (PVDF) as a binder and a solid content with respect to 92 parts by mass of nickel-cobalt-manganese (NCM) as an active material, and as a conductive aid (conductive agent) A solid content of 3 parts by mass of Denka black (powdery, manufactured by Denki Kagaku Kogyo Co., Ltd.) was charged into a dedicated container, and was kneaded by using a planetary stirrer (ARE-250, manufactured by Shinky). In order to adjust the slurry viscosity, water was added at the time of kneading and kneading was performed again to prepare a slurry for electrode coating. The composition ratio of the active material to the binder in the slurry is, as solid content, graphite powder: conductive auxiliary agent: binder composition = 92: 3: 5.

<Evaluation method: Coating property>
The thickness of arbitrary ten places was measured using the micrometer about the above-mentioned coated separator. The case where the thickness unevenness is in the range of 1 μm in absolute value (the difference between the thickest portion and the thinnest portion is 1 μm or less) is ○, and the thickness unevenness exceeds 1 μm in absolute value is ×. The results are shown in Table 4.

<Evaluation method: charge and discharge characteristic test>
The charge and discharge test was implemented using the commercially available charge and discharge tester (TOSCAT3100, Toyo System make) with respect to the produced coin battery. The coin battery was placed in a 25 ° C. constant temperature bath, and constant current charging at 0.2 C (about 0.5 mA / cm ² ) was performed until the battery voltage became 4.2V. The capacity at this time was taken as the charge capacity (mAh). Next, a constant current discharge of 0.2 C (about 0.5 mA / cm ² ) was performed until the battery voltage was 3 V. The capacity at this time was taken as the discharge capacity (mAh). The difference between the initial discharge capacity and the charge capacity was taken as the irreversible capacity, and the percentage of the discharge capacity / charge capacity was taken as the charge / discharge efficiency. The direct current resistance of the coin battery adopted the resistance value after one charge (full charge state). The results are shown in Tables 3 and 4 below. After the above initial charge and discharge, the coin battery was placed in a thermostat bath at 80 ° C., and 50 cycles of constant current charge and discharge at 10 C were performed in a voltage range of 3.0 to 4.2 V. After the test, the percentage of batteries shorted was calculated. The results are shown in Table 4 below.

<Evaluation method: contractility test>
The coated separator obtained above was cut into 5 cm squares and vacuum dried at 140 ° C. for 3 hours. After completion of drying, the area of the taken out separator was divided by the area before contraction, and the contraction rate was calculated by finding the difference from 100. The results are shown in Table 4 below.

<Evaluation method: Adhesion test>
The interface strength between the separator and the coat layer was measured for the coated separator obtained above. Specifically, each coated separator is bonded to a stainless steel plate using a double-sided tape (Nichiban double-sided tape), and a 50 N load cell (manufactured by IMADA CO., LTD.), 180 ° peel strength (peel width 10 mm, peel rate 100 mm / min) was measured. The results are shown in Table 4 below.

(Example 12)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 11 (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A) Molar ratio (A) / (B) = 1/1 of a unit (B) based on a maleic acid compound and a 10% by weight aqueous solution and a 10% by weight aqueous solution of polyethyleneimine (PEI, Wako Pure Chemical Industries, Ltd., average molecular weight 10000) Were mixed so as to give a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating.
After diluting this heating solution to 5 mass%, solid content of TRD 2001 (SBR, manufactured by JSR, average particle diameter: 200 nm) as an aqueous emulsion relative to the total amount of lithium-modified isobutene-maleic anhydride copolymer and polyethylene imine The mixture was mixed to give a mass ratio of 90:10 to obtain a separator coating liquid (solid content concentration 5.5 mass%). This separator coating liquid was applied onto a polypropylene-based separator substrate (Celgard # 2400, manufactured by Polypore), and dried at room temperature for 12 hours. The sheet after drying was pressed by a heat press apparatus (manufactured by Furukawa Seisakusho), and the thickness was adjusted to 20 μm (roll temperature, room temperature, speed 1 m / min, linear pressure 100 hg / cm). The adhesion amount was 1.9 g / m ² . Furthermore, a negative electrode for battery was produced by the same method as in Example 11 to obtain a coin battery, and a charge / discharge characteristic test was conducted. Moreover, each measurement was performed by the method similar to the said Example 11. FIG. The results are shown in Tables 3 and 4 below.

(Example 13)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 11 (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A) Molar ratio (A) / (B) = 1/1 of a unit (B) based on maleic acid compounds and a 10% by weight aqueous solution and a 10% by weight aqueous solution of polyethyleneimine (PEI, manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 1800) Were mixed so as to give a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating.
After diluting this heating solution to 5% by mass, styrene-hydrogenated isoprene-styrene triblock copolymer emulsion (manufactured by Chukyo Yushi Co., Ltd., average) relative to the total amount of lithium-modified isobutene-maleic anhydride copolymer and polyethyleneimine The particle diameter: 300 nm) was mixed so that the solid content was a mass ratio of 90:10, to obtain a separator coating liquid (solid content concentration: 5.5% by mass). This separator coating liquid was applied onto a polypropylene-based separator substrate (Celgard # 2400, manufactured by Polypore), and dried at room temperature for 12 hours. The sheet after drying was pressed by a heat press apparatus (manufactured by Furukawa Seisakusho), and the thickness was adjusted to 20 μm (roll temperature, room temperature, speed 1 m / min, linear pressure 100 hg / cm). The adhesion amount was 1.9 g / m ² . Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. Moreover, each measurement was performed by the method similar to the said Example 11. FIG. The results are shown in Tables 3 and 4 below.

(Example 14)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 11 (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A) Molar ratio (A) / (B) = 1/1 of a unit (B) based on maleic acid compounds and a 10% by weight aqueous solution and a 10% by weight aqueous solution of polyethyleneimine (PEI, manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 1800) And were mixed so as to give a mass ratio of 99: 1. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating.
After diluting this heating solution to 5% by mass, styrene-hydrogenated isoprene-styrene triblock copolymer emulsion (manufactured by Chukyo Yushi Co., Ltd., average) relative to the total amount of lithium-modified isobutene-maleic anhydride copolymer and polyethyleneimine The particle diameter: 300 nm) was mixed so that the solid content was a mass ratio of 90:10, to obtain a separator coating liquid (solid content concentration: 5.5% by mass). This separator coating liquid was applied onto a polypropylene-based separator substrate (Celgard # 2400, manufactured by Polypore), and dried at room temperature for 12 hours. The sheet after drying was pressed by a heat press apparatus (manufactured by Furukawa Seisakusho), and the thickness was adjusted to 20 μm (roll temperature, room temperature, speed 1 m / min, linear pressure 100 hg / cm). The adhesion amount was 1.9 g / m ² . Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. Moreover, each measurement was performed by the method similar to the said Example 11. FIG. The results are shown in Tables 3 and 4 below.

(Example 15)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 11 (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A) Molar ratio (A) / (B) = 1/1 of a unit (B) based on maleic acid compounds and a 10% by weight aqueous solution and a 10% by weight aqueous solution of polyethyleneimine (PEI, manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 1800) Were mixed so as to give a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating.
This heating solution is diluted to 5% by mass, and the styrene-vinyl isoprene-styrene triblock copolymer emulsion (manufactured by Chukyo Yushi Co., Ltd., average particles) relative to the total amount of the lithium-modified isobutene-maleic anhydride copolymer and the polyethyleneimine. The diameter: 200 nm) was mixed so as to have a mass ratio of 90:10 in terms of solid content, to obtain a separator coating liquid (solid content concentration: 5.5 mass%). This separator coating liquid was applied onto a polypropylene-based separator substrate (Celgard # 2400, manufactured by Polypore), and dried at room temperature for 12 hours. The sheet after drying was pressed by a heat press apparatus (manufactured by Furukawa Seisakusho), and the thickness was adjusted to 20 μm (roll temperature, room temperature, speed 1 m / min, linear pressure 100 hg / cm). The adhesion amount was 1.9 g / m ² . Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. Moreover, each measurement was performed by the method similar to the said Example 11. FIG. The results are shown in Tables 3 and 4 below.

(Example 16)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 11 (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A) Molar ratio (A) / (B) = 1/1 of a unit (B) based on maleic acid compounds and a 10% by weight aqueous solution and a 10% by weight aqueous solution of polyethyleneimine (PEI, manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 1800) Were mixed so as to give a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating.
This heating solution is diluted to 5% by mass, and then a polypropylene emulsion (Chemipearl X800-H, Mitsui Chemicals, average particle size: 200 nm) is added to the total amount of lithium-modified isobutene-maleic anhydride copolymer and polyethyleneimine. It mixed so that it might become 90:10 mass ratio in solid content, and the separator coating liquid (solid content density | concentration 5.5 mass%) was obtained. This separator coating liquid was applied onto a polypropylene-based separator substrate (Celgard # 2400, manufactured by Polypore), and dried at room temperature for 12 hours. The sheet after drying was pressed by a heat press apparatus (manufactured by Furukawa Seisakusho), and the thickness was adjusted to 20 μm (roll temperature, room temperature, speed 1 m / min, linear pressure 100 hg / cm). The adhesion amount was 1.9 g / m ² . Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. Moreover, each measurement was performed by the method similar to the said Example 11. FIG. The results are shown in Tables 3 and 4 below.

(Example 17)
Lithium-modified methyl vinyl ether-maleic anhydride copolymer prepared by the same method as in Example 11 (average molecular weight 630,000, degree of neutralization 0.5, ring opening ratio 96%, unit based on α-olefins (A And a unit (B) molar ratio based on maleic acid (A) / (B) = 1/1) 10% by mass aqueous solution and polyethyleneimine (PEI, manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 10000) 10% by mass The aqueous solution was mixed at a mass ratio of 99.67: 0.33. The resulting mixture was warmed to 90 ° C. and stirred for 6 hours with heating.
After diluting this heating solution to 5 mass%, solid content of TRD 2001 (SBR, manufactured by JSR, average particle diameter: 200 nm) as an aqueous emulsion relative to the total amount of lithium-modified isobutene-maleic anhydride copolymer and polyethylene imine The mixture was mixed to give a mass ratio of 90:10 to obtain a separator coating liquid (solid content concentration 5.5 mass%). This separator coating liquid was applied on a polypropylene resin (Celgard # 2400, manufactured by Polypore) and dried at room temperature for 12 hours. The sheet after drying was pressed by a heat press apparatus (manufactured by Furukawa Seisakusho), and the thickness was adjusted to 20 μm (roll temperature, room temperature, speed 1 m / min, linear pressure 100 hg / cm). The adhesion amount was 1.9 g / m ² . Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. Moreover, each measurement was performed by the method similar to the said Example 11. FIG. The results are shown in Tables 3 and 4 below.

(Comparative example 5)
Lithium-modified isobutene-maleic anhydride copolymer prepared by the same method as in Example 11 (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%, unit based on α-olefins (A) A molar ratio (A) / (B) = 1/1 of a unit (B) based on a maleic acid compound to a 10% by weight aqueous solution is diluted to 5 wt% and then TRD 2001 (SBR, manufactured by JSR, average particle size: 200 nm) was mixed so as to give a mass ratio of 90:10 in terms of solid content (solid content concentration 5.5 mass%). Then, a coated separator was produced by the same method as in Example 11 above. Moreover, each measurement was performed by the method similar to the said Example 11. FIG. The results are shown in Tables 3 and 4 below.

(Comparative example 6)
As a separator coating liquid, CMC-Na 1.0 mass% aqueous solution to CMC-Na, TRD 2001 (SBR, manufactured by JSR, average particle diameter: 200 nm) as an aqueous emulsion has a mass ratio of 90:10 in solid content The mixed solution was used. A coated separator was produced in the same manner as in Example 11 above. The adhesion amount was 2.0 g / m ² . Furthermore, the negative electrode for battery was produced by the method similar to the said Example 1, the coin battery was obtained, and the charge / discharge characteristic test was done. Moreover, each measurement was performed by the method similar to the said Example 11. FIG. The results are shown in Tables 3 and 4 below.

(Discussion 1)
In each of the examples using the separator coated with the separator base material surface coating liquid using the separator coating liquid of the present invention, the α-olefin-maleic acid copolymer with no crosslinking agent added and heat resistance compared to CMC-Na High, the short circuit prevention function at the time of thermal runaway was improved. Also, the current efficiency was improved. This is presumed to be due to the formation of a cross-linked structure at the carboxylic acid moiety in the copolymer by containing the polyamine, and the decrease in the carboxylic acid groups that trap Li ions. Further, in Examples 11 to 17 containing an aqueous emulsion, the thermal shrinkage during drying was suppressed, and the adhesion to the separator substrate was excellent.

(Example 18)
<Α-olefin-maleic anhydride copolymer aqueous solution>
Lithium-modified isobutene-maleic anhydride copolymer resin (average molecular weight 325,000, neutralization degree 0.5, ring opening ratio 96%) 10% by mass aqueous solution and polyethyleneimine (PEI, Wako Pure Chemical Industries, Ltd., average molecular weight 10000) It mixed with 10 mass% aqueous solution so that it might become a mass ratio of 99: 1 (resin: PEI = 6.387: 0.065 as solid content). The resulting mixture was warmed to 90 ° C. and stirred for 2 hours with heating. After that, water is added so that the resulting mixed solution has a solid content concentration of 5.5% by mass, and the mixture is uniformly stirred at a rotation number of 3600 rpm for 2 hours using a mixer mill, α-olefin-maleic anhydride copolymer An aqueous solution was obtained.

<Particulate binder>
Hydrogenated block copolymer dissolved in 15 g of polyvinyl alcohol (trade name, manufactured by Kuraray Co., Ltd., POVAL 405 (polymerization degree 500, degree of saponification 81.5%)) and 300 g of toluene in a stirring tank with a homo mixer of 1 L capacity (Septone 2002 (trade name, manufactured by Kuraray Co., Ltd., a hydrogenated product of styrene-isoprene-styrene triblock copolymer, styrene content: 30%)) 150 g of water and 500 g of water were sequentially added, and 15000 r. p. m. The mixture was stirred for 10 minutes and then transferred to a pressure homogenizer to carry out emulsification. The obtained dispersed solution was distilled of toluene and water under reduced pressure and heating (60 ° C.) using a rotary evaporator to obtain an aqueous emulsion having an average particle diameter of 0.3 μm.

<Binder composition>
The binder composition was prepared by mixing the aqueous solution of α-olefin-maleic anhydride copolymer and the particulate binder at a solid content concentration ratio of 9: 1.

<Preparation of Slurry (Coating Liquid) for Separator>
The slurry for the separator was prepared by using 0.8 parts by mass of the above binder composition (α-olefin-) with respect to 40 parts by mass of VK-BG-613 (boehmite, manufactured by Xuancheng New Materials Co., Ltd.) as a metal oxide. 0.72 parts by mass of maleic anhydride copolymer as aqueous solution solid, 0.08 parts by mass of particulate binder as solid content, and 40 parts by mass of water are charged into a dedicated container, and a planetary stirrer (ARE- It knead | mixed using 250, Shinky made).

<Preparation of Separator>
The slurry for a separator was coated with a thickness of 20 μm on a polypropylene-based porous substrate (Celgard # 2400, manufactured by Polypore) using a bar coater (T101, manufactured by Matsuo Sangyo). After coating, the coating was dried at 80 ° C. for 30 minutes with a hot air drier to obtain a coating thickness of 10 μm and a coating amount of 1.6 / cm ^2, and then allowed to cool in a desiccator to visually evaluate the state of the coating .

-Coating liquid dispersibility A: No sedimentation or phase separation visually observed B: Observation of sedimentation or phase separation visually at the gas-liquid interface

・ Applicability A: No repelling B: No repelling

・ Coated state A: Uniformly coated B: Observe spots

<Adhesiveness of Separator>
The strength when the coating film was peeled off from the polypropylene-based porous substrate was measured. The said peeling strength measured 180 degree peeling strength using the load cell (made by Imada Co., Ltd.) of 50N. The slurry-coated surface of the coated electrode for a battery obtained above is bonded to a stainless steel plate using a double-sided tape (Nichiban double-sided tape) to measure 180 ° peel strength (peel width: 10 mm, peel rate: 100 mm / min) did. The results are shown in Table 5 below. In Comparative Example 7, the slurry did not form a film, and the adhesion could not be measured.

<Preparation of Slurry for Negative Electrode>
The slurry for the electrode was prepared by using 100 parts by mass of DMGS (natural graphite, manufactured by BYD) as an active material for the negative electrode, 2.08 parts by mass of TRD 2001 (manufactured by SBR, JSR) as a solid content as a particulate binder, 1.04 parts by mass of a thickening stabilizer as solid, 1.04 parts by mass of Super-P (manufactured by Timcal) as a conductive aid (conductivity imparting agent) as solid, and charged into a dedicated container The mixture was kneaded using a stirrer (ARE-250, manufactured by Shinky). In order to adjust the slurry viscosity, water was added at the time of kneading and kneading was performed again to prepare a slurry for electrode coating. The composition ratio of the active material to the binder in the slurry is, as a solid content, graphite powder: conductive auxiliary agent: binder composition = 100: 1.04: 3.12.

<Fabrication of negative electrode for battery>
The obtained slurry is coated on copper foil (CST8G, Fukuda metal foil powder industry) of a current collector using a bar coater (T101, manufactured by Matsuo Sangyo), and heated at 80 ° C. for 30 minutes with a hot air dryer (Yamato) After primary drying in Science, a rolling process was performed using a roll press (manufactured by Takasen). Thereafter, after punching out as a battery electrode (φ 14 mm), a coin battery electrode was manufactured by secondary drying at 120 ° C. for 3 hours under reduced pressure conditions.

<Fabrication of battery>
The coated electrode for a battery obtained above was transferred to a glove box (manufactured by Miwa Seisakusho) under an argon gas atmosphere. A metal lithium foil (thickness 0.2 mm, φ16 mm) was used as the positive electrode. In addition, using the coated separator obtained above as the separator, the electrolytic solution is prepared by adding vinylene carbonate (VC) to ethylene carbonate (EC) and ethyl methyl carbonate (EMC) of lithium hexafluorophosphate (LiPF6) It injected using the mixed solvent system (1M-LiPF6, EC / EMC = 3/7 vol%, VC 2 mass%), and the coin battery (2032 type) was produced.

<Evaluation method: charge and discharge characteristic test>
The produced coin battery carried out the charge / discharge test using a commercially available charge / discharge tester (TOSCAT 3100, manufactured by Toyo System Co., Ltd.). Place the coin battery in a 25 ° C constant temperature bath, perform constant current charge of 0.1 C (about 0.5 mA / cm ² ) to the active material mass until charging becomes 0 V with respect to lithium potential, and further lithium potential Constant voltage charging at 0 V to a current of 0.02 mA. The capacity at this time was taken as the charge capacity (mAh / g). Next, a constant current discharge of 0.1 C (about 0.5 mA / cm ² ) was performed to 1.5 V with respect to the lithium potential, and the capacity at this time was defined as a discharge capacity (mAh / g). The difference between the initial discharge capacity and the charge capacity was taken as the irreversible capacity, and the percentage of the discharge capacity / charge capacity was taken as the charge / discharge efficiency. The direct current resistance of the coin battery adopted the resistance value after one charge (full charge state). The results are shown in Table 5 below.

(Example 19)
Example 18 was carried out in the same manner as Example 18, except that VL-L100D (alumina, manufactured by Xiancheng Xinyu Material Co., Ltd.) was used as the metal oxide.

Example 20
A separator, a negative electrode, and a battery were produced in the same manner as in Example 18 except that TRD2001 (SBR, manufactured by JSR) was used as a particulate binder for separators, and the same evaluation test was performed.

(Example 21)
Lithium-modified methyl vinyl ether-maleic anhydride copolymer resin (average molecular weight 630,000, neutralization degree 0.5, ring opening rate 98%) 10 mass% aqueous solution and polyethyleneimine (PEI, Wako pure) as a binder composition for a separator Example 18 except using a mixture having a mass ratio of 99: 1 (solid content: resin: PEI = 6.387: 0.065) with a 10% by weight aqueous solution manufactured by Yakuhin Kogyo Co., Ltd., average molecular weight 10000. The separator, the negative electrode, and the battery were prepared in the same manner as in the above, and the same evaluation test was performed.

(Comparative example 7)
In the binder composition for a separator, a separator, a negative electrode, and a battery were produced in the same manner as in Example 18 except that polyethyleneimine was not added, and the same evaluation test was performed.

(Discussion 2)
In Examples 18 to 21, compared with Comparative Example 7 in which the polyamine for the separator was not added to the binder composition for a separator, the adhesion of the porous film to the porous substrate in the separator was strong, and a stable film formation could be performed. . That is, a non-aqueous electrolyte battery separator excellent in surface smoothness was obtained. This is because, in the binder composition for a separator, the stability of the slurry containing the metal component is improved by the addition of the polyamine, and the adhesion to the porous substrate is improved by the particulate binder. It is guessed.
On the other hand, in Comparative Example 7, since the polyamine was not added, the slurry was not stable and a film could not be produced.

Claims

A coating liquid for a non-aqueous electrolyte battery separator, which comprises a neutralized salt of an α-olefin-maleic acid copolymer obtained by copolymerizing an α-olefin and a maleic acid, a polyamine and a solvent.
The coating liquid for a separator according to claim 1, further comprising an aqueous emulsion.
The aqueous emulsion according to claim 2, wherein the aqueous emulsion contains at least one polymer particle selected from the group consisting of an olefin polymer, a diene polymer, an acrylic polymer, and a vinyl aromatic polymer. Coating fluid for separators.
The coating liquid for a separator according to claim 2 or 3, wherein the aqueous emulsion has an average particle size of 0.01 to 0.5 μm.
The solid content of the aqueous emulsion in the coating liquid is 0.01 to 50 parts by mass with respect to 100 parts by mass of the neutralized salt of the α-olefin-maleic acid copolymer. Or the coating liquid for separators as described in 4.
The coating liquid for nonaqueous electrolyte battery separator according to any one of claims 1 to 5, further comprising at least one of a metal oxide and a metal salt.
The coating solution for nonaqueous electrolyte battery separator according to any one of claims 1 to 6, wherein the solvent is water.
The coating solution for a non-aqueous electrolyte battery separator according to any one of claims 2 to 6, wherein the aqueous emulsion is obtained by dispersing and emulsifying a particulate binder in an aqueous solvent.
A non-aqueous electrolyte battery separator comprising a separator substrate and a separator coating layer formed on the substrate from the coating liquid for a separator according to any one of claims 1 to 8.
A non-aqueous electrolyte battery comprising the separator according to claim 9.