JP2016100149A - Composition for nonaqueous secondary battery adhesion layer, adhesion layer for nonaqueous secondary battery, nonaqueous secondary battery member, nonaqueous secondary battery, and method for manufacturing adhesion layer for nonaqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for a nonaqueous secondary battery adhesion layer, in which the composition is superior in adhesiveness in an electrolyte and enables the formation of an adhesion layer for a nonaqueous secondary battery, which allows a nonaqueous secondary battery to show an excellent electric property.SOLUTION: A composition for a nonaqueous secondary battery adhesion layer comprises: a particulate binding material A; and water. The particulate binding material A includes a polymer A including 0.1-20 mass% of monomer units each including an alkoxy silyl group.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a non-aqueous secondary battery adhesive layer composition, a non-aqueous secondary battery adhesive layer, a non-aqueous secondary battery member, a non-aqueous secondary battery, and a method for producing a non-aqueous secondary battery adhesive layer. Is.

  Non-aqueous secondary batteries such as lithium ion secondary batteries are small and light, have high energy density, and can be repeatedly charged and discharged, and are used in a wide range of applications. Therefore, in recent years, various studies have been made for the purpose of further improving the performance of non-aqueous secondary batteries.

  Specifically, for example, in Patent Document 1 and the like, the electrode and the separator are bonded and integrated by an adhesive layer, and by suppressing the swelling of the cells and the increase in the distance between the electrode plates due to repeated charging and discharging, Techniques for improving the electrical characteristics of secondary batteries have been proposed.

Here, in a non-aqueous secondary battery such as a lithium ion secondary battery, as an electrode bonded to a separator via an adhesive layer, for example, an electrode base material formed by forming an electrode mixture layer on a current collector An electrode obtained by providing an adhesive layer on an electrode substrate obtained by forming a porous film layer for the purpose of further improving heat resistance and strength on the electrode mixture layer is used. Moreover, as a separator bonded to an electrode through an adhesive layer, for example, a separator obtained by providing an adhesive layer on a separator substrate formed by forming a porous film layer on an organic separator made of polyolefin or the like is provided. It is used.
And the electrode mixture layer of the electrode substrate is applied on the current collector, for example, an electrode slurry composition including an electrode active material and a binder for the electrode mixture layer having binding properties. It is formed by drying the applied electrode slurry composition. In addition, the porous membrane layer disposed on the surface of the electrode or separator is formed by, for example, forming a slurry composition for a porous membrane layer containing non-conductive particles and a binder for a porous membrane layer having binding properties, It is formed by applying on a composite material layer or an organic separator and drying the applied slurry composition for a porous membrane layer.

JP 2001-84985 A

  Here, in recent years, from the viewpoint of reducing the environmental load, an adhesive layer formed by dissolving or dispersing an adhesive in a hydrophilic solvent such as water is used to form an adhesive layer that bonds battery members (electrodes, separators) to each other. It has been proposed to use a composition for use. Specifically, the adhesive layer composition containing a hydrophilic solvent is supplied to at least one surface of the electrode substrate and the separator substrate, and the supplied adhesive layer composition is dried, whereby the adhesive layer is formed on the surface. It has been proposed to form a battery member.

  However, the adhesive layer manufactured by the conventional method is not particularly adhesive in an electrolyte solution, and exhibits excellent electrical characteristics for a secondary battery in which battery members are bonded to each other by the adhesive layer. I couldn't let you. Therefore, there has been a demand for a new technique for improving the adhesive property of the adhesive layer in the electrolytic solution and improving the electrical characteristics of the secondary battery using the adhesive layer.

Accordingly, the present invention provides a non-aqueous secondary battery adhesive capable of forming an adhesive layer for a non-aqueous secondary battery that has excellent adhesion in an electrolyte solution and can exhibit excellent electrical characteristics in a non-aqueous secondary battery. It aims at providing the composition for layers.
The present invention also provides an adhesive layer for a non-aqueous secondary battery that is excellent in adhesion in an electrolytic solution and that can exhibit excellent electrical characteristics in a non-aqueous secondary battery, and the non-aqueous secondary battery. It aims at providing a non-aqueous secondary battery member provided with the contact bonding layer for batteries.
Furthermore, an object of this invention is to provide the non-aqueous secondary battery which is excellent in an electrical property.
And this invention aims at providing the manufacturing method of the contact bonding layer for non-aqueous secondary batteries which is excellent in the adhesiveness in electrolyte solution, and can exhibit the electrical property excellent in the non-aqueous secondary battery. To do.

  Hereinafter, in the present specification, the electrode mixture layer and / or the porous membrane layer may be referred to as a “functional layer”.

  The present inventor has intensively studied for the purpose of solving the above problems. And, the present inventor uses a particulate binder containing a copolymer containing an alkoxysilyl group-containing monomer unit at a ratio within a specific range as an adhesive component of the adhesive layer composition. The present inventors have found that an adhesive layer that is excellent in adhesion in an electrolytic solution and can exhibit excellent electrical characteristics in a secondary battery can be formed, and the present invention has been completed.

  That is, the present invention aims to advantageously solve the above-described problems, and the composition for a non-aqueous secondary battery adhesive layer of the present invention is a non-aqueous two-component composition containing a particulate binder A and water. In the composition for a secondary battery adhesive layer, the particulate binder A contains 0.1 to 20% by mass of an alkoxysilyl group-containing monomer unit. If the particulate binder A containing the polymer A containing 0.1% by mass or more and 20% by mass or less of a monomer unit derived from an alkoxysilyl group-containing monomer is used, the adhesiveness in the electrolytic solution is excellent. In addition, an adhesive layer for a non-aqueous secondary battery can be manufactured, and a non-aqueous secondary battery using the adhesive layer is excellent in electrical characteristics such as high-temperature cycle characteristics and low-temperature output characteristics.

  Here, the composition for a non-aqueous secondary battery adhesive layer of the present invention has a core-shell structure in which the particulate binder A includes a core portion and a shell portion that partially covers the outer surface of the core portion. The core portion is made of a polymer having an electrolyte solution swelling degree of 5 to 30 times, the shell portion is made of the polymer A, and the electrolyte solution swelling degree of the polymer A is It is preferably more than 1 time and 4 times or less. Thus, the particulate binder A has a specific core-shell structure, the degree of electrolyte swelling of the polymer constituting the core portion is 5 times or more and 30 times or less, and the shell portion is the polymer described above. This is because the electrical characteristics of the non-aqueous secondary battery such as low-temperature output characteristics can be further improved if it is made of A and the degree of swelling of the electrolyte solution of the polymer A is more than 1 time and 4 times or less.

  And it is preferable that pH of the composition for non-aqueous secondary battery contact bonding layers of this invention is 3-6. If the pH of the composition for a non-aqueous secondary battery adhesive layer is 3 or more and 6 or less, in the composition for an adhesive layer, the reactivity of the alkoxysilyl group in the particulate binder A is lowered and the stability is increased. Therefore, as a result, the adhesiveness of the obtained adhesive layer in the electrolytic solution can be further improved.

  Moreover, this invention aims at solving the said subject advantageously, The adhesive layer for non-aqueous secondary batteries of this invention is the composition for any of the non-aqueous secondary battery adhesive layers mentioned above. It is formed using. As described above, the adhesive layer formed using any one of the adhesive layer compositions described above is excellent in adhesiveness in an electrolytic solution and exhibits excellent electrical characteristics in a non-aqueous secondary battery. Can do.

  In addition, the present invention aims to advantageously solve the above-mentioned problems, and the non-aqueous secondary battery member of the present invention is adjacent to a functional layer containing inorganic oxide particles and the functional layer. And the above-described adhesive layer for non-aqueous secondary batteries. Thus, in the electrode or separator in which the above-mentioned adhesive layer is directly provided on the functional layer containing inorganic oxide particles, the adhesive layer and the functional layer (porous membrane layer, electrode mixture layer) are good in the electrolyte. In addition, the non-aqueous secondary battery can exhibit excellent electrical characteristics.

  Moreover, this invention aims at solving the said subject advantageously, The non-aqueous secondary battery of this invention is the above-mentioned contact bonding layer for non-aqueous secondary batteries, and the above-mentioned non-aqueous secondary battery. At least one of the members is provided. Thus, the non-aqueous secondary battery including the above-described adhesive layer is excellent in electrical characteristics such as high temperature cycle characteristics and low temperature output characteristics.

  Moreover, this invention aims at solving the said subject advantageously, and the manufacturing method of the contact bonding layer for non-aqueous secondary batteries of this invention is one of the non-aqueous secondary battery contact bonding layers mentioned above. Including a step of supplying a composition for use on a functional layer containing inorganic oxide particles, and a step of drying the composition for a non-aqueous secondary battery adhesive layer supplied on the functional layer. To do. As described above, the adhesive layer manufactured on the functional layer containing the inorganic oxide particles can adhere well to the functional layer in the electrolytic solution, and can exhibit excellent electrical characteristics in the non-aqueous secondary battery. it can.

ADVANTAGE OF THE INVENTION According to this invention, the nonaqueous secondary battery adhesion | attachment which can form the contact bonding layer for nonaqueous secondary batteries which is excellent in the adhesiveness in electrolyte solution, and can exhibit the electrical property excellent in the nonaqueous secondary battery A layer composition can be provided.
In addition, according to the present invention, the adhesive layer for a non-aqueous secondary battery that is excellent in adhesion in an electrolytic solution and can exhibit excellent electrical characteristics in the non-aqueous secondary battery, and the non-aqueous system A non-aqueous secondary battery member provided with a secondary battery adhesive layer can be provided.
Furthermore, according to the present invention, a nonaqueous secondary battery having excellent electrical characteristics can be provided.
And according to this invention, providing the manufacturing method of the contact bonding layer for non-aqueous secondary batteries which is excellent in the adhesiveness in electrolyte solution, and can exhibit the electrical property excellent in the non-aqueous secondary battery. it can.

It is sectional drawing which shows typically the structure of an example of the particulate binder A contained in the composition for non-aqueous secondary battery contact bonding layers of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
Here, the composition for non-aqueous secondary battery adhesive layers of the present invention is used as a material for preparing the non-aqueous secondary battery adhesive layer of the present invention. The non-aqueous secondary battery adhesive layer of the present invention is prepared using the non-aqueous secondary battery adhesive layer composition of the present invention and constitutes a part of a non-aqueous secondary battery member such as a separator or an electrode. To do. And the non-aqueous secondary battery member of this invention is equipped with the contact bonding layer of this invention. Furthermore, the non-aqueous secondary battery of the present invention is formed by bonding non-aqueous secondary battery members through the non-aqueous secondary battery adhesive layer of the present invention. Moreover, the adhesive layer for non-aqueous secondary batteries of this invention can be manufactured, for example according to the manufacturing method of the adhesive layer for non-aqueous secondary batteries of this invention.

(Composition for non-aqueous secondary battery adhesive layer)
The composition for a non-aqueous secondary battery adhesive layer of the present invention contains at least a particulate binder A having binding properties, and optionally contains a binder other than the particulate binder A and other components. A slurry composition using water as a dispersion medium.
And the adhesive layer formed using the composition for non-aqueous secondary battery adhesive layers of the present invention is excellent in adhesiveness in an electrolyte solution and exhibits excellent electrical characteristics in secondary batteries. Can do.
The proportion of the particulate binder A contained in the composition for non-aqueous secondary battery adhesive layer is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more. Usually, it is 90 mass% or less.

<Particulate binder A>
The particulate binder A is a component that functions as a binder that ensures the adhesion of the resulting adhesive layer. Here, the particulate binder A is usually composed of a water-insoluble polymer, and is present in the form of particles in the aqueous medium, and is included in the adhesive layer while maintaining the particle shape.
In the present invention, the “water-insoluble polymer” refers to a polymer having an insoluble content of 80% by mass or more when 0.5 g of the polymer is dissolved in 100 g of water at a temperature of 25 ° C. .

  And the particulate binder A contains the polymer A containing 0.1 to 20% by mass of an alkoxysilyl group-containing monomer unit. In the present specification, “including a monomer unit” means “a monomer-derived structural unit is included in a polymer obtained using the monomer”.

  Here, the adhesive layer using the particulate binder A having the polymer A containing the alkoxysilyl group-containing monomer unit at the above-described content ratio exhibits excellent adhesiveness in the electrolytic solution, The electrical characteristics of the non-aqueous secondary battery including the adhesive layer can be improved satisfactorily.

The reason why the above-described excellent effect can be obtained by using the particulate binder A is not clear, but is presumed to be as follows.
That is, the alkoxysilyl group of the particulate binder A contained in the adhesive layer can be converted into a silanol group through hydrolysis. When this silanol group is formed on the substrate by drying the adhesive layer composition to form an adhesive layer, for example, a functional group such as a hydroxyl group of a compounding component in the substrate, for example, a function disposed on the outermost surface of the substrate Since the inorganic oxide particles in the layer (non-conductive particles in the porous membrane layer and the electrode active material in the electrode mixture layer) interact with the hydroxyl groups generated by contact with water, such as by dehydration condensation, It is presumed that the adhesiveness between the functional layers arranged adjacent to the adhesive layer (that is, the adhesiveness between the adhesive layer and the substrate) is improved, and this excellent adhesiveness is exhibited even in the electrolytic solution.
In addition, as described above, for example, when the adhesive layer and the functional layer undergo dehydration condensation, the moisture inherent in the inorganic oxide particles in the functional layer can be discharged out of the system together with the secondary layer. It is presumed that the amount of moisture brought into the battery can be reduced, and gas generation caused by decomposition of the electrolytic solution is suppressed, and swelling of the battery cell can be suppressed.
And it is guessed that electrical characteristics, such as a high temperature cycling characteristic and a low temperature output characteristic, can be improved by contributions, such as an adhesive improvement mentioned above and reduction of the amount of brought-in water.

[Structure of particulate binder A]
The structure of the particulate binder A is not particularly limited, and may be a non-composite polymer composed substantially of a single polymer component (polymer A), or at least 1 with the polymer A. It may be a composite polymer composed of a polymer other than the seed polymer A.
Further, in the particulate binder A, the polymer A is preferably present on the outer surface portion of the particulate binder A (that is, the portion constituting the peripheral surface of the particulate binder A). This is because when the polymer A constitutes part or all of the outer surface portion of the particulate binder A, the resulting adhesive layer can exhibit good adhesion in the electrolyte.

The composite polymer is prepared by polymerizing at least one monomer component according to a conventional method, and then polymerizing at least one other monomer component according to a conventional method (two-stage polymerization method). It can be manufactured easily. And the particle | grains which consist of a composite polymer become a heterophasic structure in which a different polymer part exists in the inside of particle | grains.
Here, the heterophasic structure is a single particle formed by physically or chemically combining two or more different polymers, and is formed from a single polymer such as a block polymer. It is not a particle having a single phase structure. A specific example of the heterophasic structure is a core-shell structure in which spherical particles are formed of a polymer having a central part and an outer shell part different from each other; a side-by-side structure in which two or more polymers are juxtaposed. Structure: Snow Dharma structure in which a part of the polymer at the center of the core-shell structure is exposed to the outer shell; a structure in which different polymer particles are embedded and integrated on the surface of spherical polymer particles And the like.

  Among such structures, the particulate binder A is preferably a non-composite polymer substantially composed only of the polymer A, or a composite polymer having a core-shell structure. Hereinafter, the particulate binder A as a non-composite polymer and the particulate binder A as a composite polymer having a core-shell structure will be described in detail.

[[Particulate Binder A as Non-Composite Polymer]]
When the particulate binder A is a non-composite polymer, the particulate binder A substantially consists of the polymer A. Here, the polymer A is prepared using an aromatic vinyl monomer, an acid group-containing monomer, a crosslinkable monomer, etc. in addition to the alkoxysilyl group-containing monomer.

-Alkoxysilyl group-containing monomer-
Examples of the alkoxysilyl group-containing monomer include an alkoxysilyl group, a structure copolymerizable with other monomers (for example, a polymerizable unsaturated bond such as a carbon-carbon double bond, and an alkoxysilyl group). If it is a monomer containing, it will not specifically limit. Here, the alkoxysilyl group may be a monoalkoxysilyl group, a dialkoxysilyl group, or a trialkoxysilyl group, but is preferably a trialkoxysilyl group.

As the alkoxysilyl group-containing monomer, from the viewpoint of reducing the amount of moisture brought into the secondary battery while further improving the adhesiveness of the adhesive layer, a vinylsilane monomer or a (meth) acrylsilane monomer Are preferable.
Examples of the vinylsilane monomer include vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (2-methoxyethoxy) silane, and vinylmethyldimethoxysilane.
Examples of the (meth) acrylic silane monomer include 3-methacryloxypropyltriethoxysilane and 3-methacryloxypropyltrimethoxysilane.
Among these, 3-methacryloxypropyltriethoxysilane and vinyltriethoxysilane are more preferable.
In the present specification, “(meth) acryl” means acryl and / or methacryl. Moreover, an alkoxysilyl group containing monomer may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content ratio of the alkoxysilyl group-containing monomer unit in the polymer A needs to be 0.1% by mass or more and 20% by mass or less, preferably 0.5% by mass or more, more preferably 1.5% by mass. It is at least mass%, more preferably at least 1.8 mass%, preferably at most 15 mass%, more preferably at most 10 mass%, still more preferably at most 8 mass%. When the proportion of the alkoxysilyl group-containing monomer unit is less than the lower limit of the above range, the adhesiveness of the adhesive layer in the electrolytic solution cannot be ensured, and the amount of moisture brought into the secondary battery increases. In addition, the electrical characteristics of the secondary battery are degraded. Further, if the proportion of the alkoxysilyl group-containing monomer unit is more than the upper limit of the above range, silanol groups produced by conversion of the alkoxysilyl group in the polymer A will undergo dehydration condensation, so the substrate side As a result, the reactivity with the hydroxyl group decreases, and the adhesive layer cannot be satisfactorily adhered to the substrate in the electrolyte. In addition, the polymer A has excessive hydrophilicity, the amount of moisture brought into the secondary battery is increased, and the low-temperature output characteristics of the secondary battery are deteriorated.

  In the composition for an adhesive layer, which is an aqueous slurry, the alkoxysilyl group in the polymer A may be converted to a silanol group by hydrolysis, and the alkoxysilyl group is converted to a silanol group. The body unit is also included in the alkoxysilyl group-containing monomer unit (a monomer unit derived from an alkoxysilyl group-containing monomer).

-Aromatic vinyl monomer-
Polymer A preferably includes aromatic vinyl monomer units. Among the aromatic vinyl monomers, styrene derivatives such as styrene and styrene sulfonic acid are more preferable, and styrene is preferable. If an aromatic vinyl monomer is used for the preparation of the polymer A, the degree of electrolyte solution swelling of the polymer A can be easily controlled within a suitable range described later. Moreover, the adhesiveness in the electrolyte solution of the adhesive layer obtained can be improved further.
In addition, an aromatic vinyl monomer may be used individually by 1 type, and may be used in combination of 2 or more types.

  The ratio of the aromatic vinyl monomer unit in the polymer A is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 85% by mass or more, preferably 95% by mass or less, more preferably. It is 93 mass% or less, More preferably, it is 92 mass% or less. By keeping the ratio of the aromatic vinyl monomer unit within the above range, the adhesiveness of the adhesive layer in the electrolytic solution can be further improved. Moreover, it is easy to control the electrolyte solution swelling degree and glass transition temperature of the polymer A to the suitable range mentioned later.

-Acid group-containing monomer-
The polymer A may contain an acid group-containing monomer unit. Here, as the acid group-containing monomer, a monomer having an acid group, for example, a monomer having a carboxylic acid group, a monomer having a sulfonic acid group, a monomer having a phosphoric acid group, and And monomers having a hydroxyl group.

Examples of the monomer having a carboxylic acid group include monocarboxylic acid and dicarboxylic acid. Examples of the monocarboxylic acid include acrylic acid, methacrylic acid, and crotonic acid. Examples of the dicarboxylic acid include maleic acid, fumaric acid, itaconic acid and the like.
Examples of the monomer having a sulfonic acid group include vinyl sulfonic acid, methyl vinyl sulfonic acid, (meth) allyl sulfonic acid, (meth) acrylic acid-2-ethyl sulfonate, 2-acrylamido-2-methyl. Examples thereof include propanesulfonic acid and 3-allyloxy-2-hydroxypropanesulfonic acid. In the present specification, “(meth) allyl” means allyl and / or methallyl.
Furthermore, examples of the monomer having a phosphoric acid group include phosphoric acid-2- (meth) acryloyloxyethyl phosphate, methyl-2- (meth) acryloyloxyethyl phosphate, and ethyl phosphate- (meth) acryloyloxyethyl phosphate. Etc. In the present specification, “(meth) acryloyl” means acryloyl and / or methacryloyl.
Examples of the monomer having a hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. The monomer having a hydroxyl group does not include a monomer having a silanol group.

Among these, as the acid group-containing monomer, a monomer having a carboxylic acid group is preferable, among which monocarboxylic acid is preferable, and (meth) acrylic acid is more preferable.
Moreover, an acid group containing monomer may be used individually by 1 type, and may be used in combination of 2 or more types.

  The ratio of the acid group-containing monomer unit in the polymer A is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 3% by mass or more, and preferably 20% by mass or less. More preferably, it is 10 mass% or less, More preferably, it is 7 mass% or less. By keeping the ratio of the acid group-containing monomer units within the above range, the dispersibility of the polymer A (that is, the particulate binder A) in the adhesive layer is improved, and good adhesion is achieved over the entire surface of the adhesive layer. Sex can be expressed.

-Crosslinkable monomer-
The polymer A can contain a crosslinkable monomer unit. A crosslinkable monomer is a monomer that can form a crosslinked structure during or after polymerization by heating or irradiation with energy rays. By including a crosslinkable monomer unit, the degree of swelling of the polymer can be easily within the above range.

  And as a crosslinkable monomer, the polyfunctional monomer which has a 2 or more polymerization reactive group in the said monomer is mentioned, for example. Examples of such polyfunctional monomers include divinyl compounds such as divinylbenzene; di (meth) acrylic acid esters such as diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, and 1,3-butylene glycol diacrylate. Compounds; tri (meth) acrylic acid ester compounds such as trimethylolpropane trimethacrylate and trimethylolpropane triacrylate; ethylenically unsaturated monomers containing epoxy groups such as allyl glycidyl ether and glycidyl methacrylate; and the like. Among these, ethylene glycol dimethacrylate, allyl glycidyl ether, and glycidyl methacrylate are preferable, and ethylene glycol dimethacrylate is more preferable, from the viewpoint of easily controlling the degree of electrolyte solution swelling. Moreover, a crosslinking | crosslinked monomer may be used individually by 1 type, and may be used in combination of 2 or more types.

  And when the polymer A contains a crosslinkable monomer unit, the ratio of the crosslinkable monomer unit in the polymer A is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and Preferably it is 0.5 mass% or more, Preferably it is 5 mass% or less, More preferably, it is 4 mass% or less, More preferably, it is 3 mass% or less.

-Properties of particulate binder A (non-composite polymer)-
The glass transition temperature of the particulate binder A (polymer A) as a non-composite polymer is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, further preferably 70 ° C. or higher, particularly preferably 80 ° C. or higher. Yes, preferably 200 ° C. or lower, more preferably 150 ° C. or lower, still more preferably 120 ° C. or lower, particularly preferably 100 ° C. or lower. By setting the glass transition temperature of the particulate binder A to be equal to or higher than the lower limit of the above range, the high-temperature cycle characteristics of the secondary battery can be improved. Moreover, the adhesiveness in the electrolyte solution of a contact bonding layer can further be improved by making the glass transition temperature of the particulate binder A below the upper limit of the said range.
The “glass transition temperature” of the particulate binder A (polymer A) can be measured using the method described in the examples of the present specification.

The electrolyte solution swelling degree of the particulate binder A (polymer A) as the non-composite polymer is preferably more than 1 time, more preferably 1.1 times or more, and 1.2 times or more. More preferably, it is 4 times or less, more preferably 3.5 times or less, and further preferably 3 times or less. By setting the degree of swelling of the electrolytic solution of the particulate binder A to be equal to or higher than the lower limit of the above range, the adhesiveness of the adhesive layer in the electrolytic solution can be improved and the high-temperature cycle characteristics of the secondary battery can be further improved. . Further, by making the degree of swelling of the electrolyte solution of the particulate binder A below the upper limit of the above range, the adhesion of the adhesive layer in the electrolyte solution can be improved and the high-temperature cycle characteristics of the secondary battery can be further improved. be able to.
The “electrolyte swelling degree” of the particulate binder A (polymer A) is a measurement of the electrolyte swelling degree described later in the section “Particulate binder A as a composite polymer having a core-shell structure”. It can be measured according to the method.

The volume average particle diameter D50 of the particulate binder A as the non-composite polymer is preferably 0.05 μm or more, more preferably 0.1 μm or more, preferably 5 μm or less, more preferably 1 μm or less. is there. By setting the volume average particle diameter D50 of the particulate binder A to be equal to or greater than the lower limit of the above range, it is possible to suppress an increase in the internal resistance of the adhesive layer and further improve the low temperature output characteristics of the secondary battery. Further, by making the volume average particle diameter D50 of the particulate binder A not more than the upper limit of the above range, the adhesiveness of the particulate binder A in the electrolytic solution is improved, and the high temperature cycle characteristics are further improved. be able to.
In addition, the volume average particle diameter D50 of the particulate binder A is a particle diameter distribution of a water dispersion adjusted to a solid content concentration of 15% by mass using a laser diffraction particle diameter distribution measuring apparatus. It can be determined as the particle diameter at which the cumulative volume calculated from the small diameter side is 50%.

-Method for preparing particulate binder A (non-composite polymer)-
Examples of the method for preparing the particulate binder A as the non-composite polymer include a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. Among them, the polymerization can be carried out in water, and an aqueous dispersion containing the particulate binder A made of the polymer A can be suitably used as a material for the adhesive layer composition as it is. Legal is preferred. The particulate binder A as a non-composite polymer is usually formed by the polymer A substantially constituting it, but may be accompanied by any component such as an additive used in the polymerization. .

[[Particulate binder A as a composite polymer having a core-shell structure]]
When the particulate binder A is a composite polymer having a core-shell structure, the shell portion is preferably made of the polymer A described above. If the shell portion is composed of the polymer A, the particulate binder can be obtained by applying a polymer component other than the polymer A to the core portion while ensuring the adhesion of the adhesive layer in the electrolyte solution. This is because the performance of A can be improved. In addition, you may include the polymer A in a core part.

  More specifically, the particulate binder A has a core-shell structure including a core portion and a shell portion that partially covers the outer surface of the core portion, and the core portion has a degree of electrolyte swelling. Is more preferably 5 times or more and 30 times or less, and the shell part is made of the above-described polymer A, and the electrolyte solution swelling degree of the polymer A is more preferably more than 1 time and 4 times or less. .

  In this way, the adhesion of the adhesive layer in the electrolyte is further enhanced by having the electrolyte swelling degree of the polymer that has a specific core-shell structure and the core part and the shell part within a specific range. On the other hand, the electrical characteristics such as the low temperature output characteristics of the non-aqueous secondary battery including the adhesive layer can be further improved.

The excellent effect as described above by using the particulate binder A having a specific core-shell structure and having the electrolyte portion swelling degree of the core portion and the polymer constituting the shell portion within a specific range. The reason why is obtained is not clear, but is assumed to be as follows.
First, due to the contribution of the alkoxysilyl group of the polymer A constituting the shell portion described above, the adhesive layer is particularly well bonded to the base material (electrode base material, separator base material) before being immersed in the electrolytic solution. However, the polymer A in the shell portion swells in the electrolytic solution, so that the adhesion becomes stronger, and the adhesive layer adheres on the surface opposite to the base material and the adhesive layer. The adhesiveness between them can also be improved. Specifically, when the polymer A constituting the shell portion swells with respect to the electrolytic solution, for example, the functional group (excluding the alkoxysilyl group and silanol group) of the polymer A in the swollen shell portion is activated. Due to factors such as causing chemical or electrical interaction with the surface of the base material or the battery member, the battery members (for example, the separator and the electrode) are connected to each other through the adhesive layer containing the particulate binder A as an electrolytic solution. It is presumed that it can be strongly bonded inside.
In addition, since the separator and the electrode can be strongly bonded in the electrolytic solution as described above, in the secondary battery including the adhesive layer, between the battery members bonded via the adhesive layer (for example, the separator and It is difficult to generate a gap between the electrode). Therefore, in the secondary battery using the adhesive layer containing the particulate binder A, the distance between the positive electrode and the negative electrode is not easily increased in the secondary battery, the internal resistance of the secondary battery can be reduced, and the electric power in the electrode can be reduced. The reaction field for chemical reactions is unlikely to be uneven. Furthermore, in the secondary battery, even if charging and discharging are repeated, it is difficult to form a gap between the separator and the electrode, and the battery capacity is unlikely to decrease. As a result, it is presumed that excellent swelling resistance and high-temperature cycle characteristics can be realized.
Furthermore, the polymer constituting the core portion of the particulate binder A swells greatly with respect to the electrolytic solution. When the polymer is greatly swollen in the electrolytic solution, the gap between the molecules of the polymer becomes large, and ions easily pass between the molecules. Further, the polymer in the core portion of the particulate binder A is not completely covered by the shell portion. Therefore, since ions easily pass through the core portion in the electrolytic solution, the particulate binder A can exhibit high ion diffusibility. Therefore, if the particulate binder A is used, it is presumed that an increase in resistance due to the adhesive layer can be suppressed and a decrease in electrical characteristics such as low-temperature output characteristics can be suppressed.

  The particulate binder A having the specific core-shell structure described above has a core-shell structure including a core part and a shell part that covers the outer surface of the core part, and the shell part is a core part. Partially covering the outer surface of the. That is, the shell part of the particulate binder A covers the outer surface of the core part, but does not cover the entire outer surface of the core part. Even if it appears that the outer surface of the core part is completely covered by the shell part, the shell part is outside the core part as long as a hole that communicates the inside and outside of the shell part is formed. A shell part that partially covers the surface. Therefore, for example, when a shell portion having pores communicating from the outer surface of the shell portion (that is, the peripheral surface of the particulate binder A) to the outer surface of the core portion is provided, the shell of the particulate binder A The part partially covers the core part.

  FIG. 1 shows a cross-sectional structure of an example of the particulate binder A having the specific core-shell structure described above. The particulate binder A100 has a core-shell structure including a core part 110 and a shell part 120. Here, the core part 110 is a part which exists inside the shell part 120 in the particulate binder A100. Moreover, the shell part 120 is a part which covers the outer surface 110S of the core part 110, and is usually a part which is the outermost part in the particulate binder A100. The shell portion 120 does not cover the entire outer surface 110S of the core portion 110, but partially covers the outer surface 110S of the core portion 110.

  Here, in the particulate binder A, the average ratio (coverage) at which the outer surface of the core part is covered by the shell part is preferably 10% or more, more preferably 30% or more, and further preferably 50% or more. Yes, preferably 95% or less, more preferably 90% or less, and still more preferably 80% or less. The adhesiveness in the electrolyte solution of a contact bonding layer can further be improved by making a coverage more than the lower limit of the said range. Moreover, by setting the coverage to be equal to or less than the upper limit of the above range, the ion diffusibility of the adhesive layer is increased, and the low temperature output characteristics of the secondary battery can be further improved.

The average ratio at which the outer surface of the core part is covered with the shell part can be measured from the observation result of the cross-sectional structure of the particulate binder A. Specifically, it can be measured by the method described below.
First, the particulate binder A is sufficiently dispersed in a room temperature curable epoxy resin and then embedded to produce a block piece containing the particulate binder A. Next, the block piece is cut into a thin piece having a thickness of 80 nm to 200 nm with a microtome equipped with a diamond blade to prepare a measurement sample. Thereafter, if necessary, the measurement sample is stained using, for example, ruthenium tetroxide or osmium tetroxide.
Next, this measurement sample is set in a transmission electron microscope (TEM), and the cross-sectional structure of the particulate binder A is photographed. The magnification of the electron microscope is preferably a magnification in which the cross section of one particulate binder A enters the field of view, specifically about 10,000 times.
In the photographed cross-sectional structure of the particulate binder A, the circumferential length D1 corresponding to the outer surface of the core part and the length D2 of the part where the outer surface of the core part and the shell part abut are measured. . And the ratio Rc by which the outer surface of the core part of the particulate binder A is covered with the shell part is calculated by the following formula (1) using the measured length D1 and length D2.
Covering ratio Rc (%) = (D2 / D1) × 100 (1)
The covering ratio Rc is measured for 20 or more particulate binders A, and an average value thereof is calculated to obtain an average ratio (covering ratio) at which the outer surface of the core portion is covered by the shell portion.
Here, the covering ratio Rc can be calculated manually from the cross-sectional structure, but can also be calculated using commercially available image analysis software. As commercially available image analysis software, for example, “AnalySIS Pro” (manufactured by Olympus Corporation) can be used.

  In addition, the particulate binder A may be provided with arbitrary components other than the core part and shell part which were mentioned above, unless the expected effect is impaired remarkably. Specifically, for example, the particulate binder A may have a part formed of a polymer different from the core part inside the core part. As a specific example, the seed particles used when the particulate binder A is produced by the seed polymerization method may remain inside the core portion. However, it is preferable that the particulate binder A includes only the core part and the shell part from the viewpoint of remarkably exhibiting the expected effect.

  Further, the volume average particle diameter D50 of the particulate binder A as the composite polymer having the core-shell structure is measured in the same manner as the volume average particle diameter D50 of the particulate binder A as the non-composite polymer. The preferred range and the reason why it is preferred to be within the range are the same as those of the particulate binder A as the non-composite polymer.

-Core part-
The core part of the particulate binder A is preferably made of a polymer having a predetermined degree of swelling with respect to the electrolytic solution. Specifically, the electrolyte swelling degree of the polymer of the core part is preferably 5 times or more, more preferably 6 times or more, further preferably 7 times or more, and 30 times. Is preferably 25 times or less, more preferably 20 times or less. By setting the electrolyte swelling degree of the polymer of the core part to be equal to or higher than the lower limit of the above range, the ion diffusibility of the adhesive layer can be increased and the low-temperature output characteristics of the secondary battery can be further improved. Moreover, the adhesiveness in the electrolyte solution of a contact bonding layer can be improved and the high temperature cycling characteristic can further be improved by making electrolyte solution swelling degree of the polymer of a core part below the upper limit of the said range.

Here, as an electrolytic solution used for measuring the degree of swelling of the electrolytic solution of the polymer in the core part, a mixed solvent of ethylene carbonate (EC), diethyl carbonate (DEC), and vinylene carbonate (VC) (volume mixing ratio EC / DEC / VC = 68.5 / 30 / 1.5; SP value 12.7 (cal / cm ³ ) ^1/2 ) As a supporting electrolyte, a solution obtained by dissolving LiPF ₆ at a concentration of 1 mol / L is used.

And the electrolyte solution swelling degree of the polymer of a core part can be specifically measured as follows.
First, the polymer of the core part of the particulate binder A is prepared. For example, a polymer obtained by performing the same process as that for forming the core part in the preparation of the particulate binder A is prepared. Then, a film is produced with the prepared polymer. For example, if the polymer is solid, the polymer is dried at a temperature of 25 ° C. for 48 hours, and then the polymer is formed into a film to produce a film having a thickness of 0.5 mm. In addition, for example, when the polymer is a solution or dispersion such as latex, the solution or dispersion is put in a petri dish made of polytetrafluoroethylene, dried at a temperature of 60 ° C. for 72 hours, and then necessary. In response to the above, a film having a thickness of 0.5 mm is produced.
Next, the film produced as described above is cut into a 1 cm square to obtain a test piece. The weight of this test piece is measured and set to W0. Moreover, this test piece is immersed in the said electrolyte solution at the temperature of 60 degreeC for 72 hours, and the test piece is taken out from electrolyte solution. The electrolyte solution on the surface of the removed test piece is wiped off, and the weight W1 of the test piece after immersion is measured.
Then, using these weights W0 and W1, the degree of swelling S (times) is calculated as S = W1 / W0.

  In addition, as a method for adjusting the electrolyte solution swelling degree of the polymer of the core part, for example, considering the SP value of the electrolyte solution, the type and amount of the monomer for producing the polymer of the core part are determined. Appropriate selection can be mentioned. Generally, when the SP value of a polymer is close to the SP value of an electrolytic solution, the polymer tends to swell in the electrolytic solution. On the other hand, when the SP value of the polymer is far from the SP value of the electrolytic solution, the polymer tends to hardly swell in the electrolytic solution.

Here, the SP value means a solubility parameter.
The SP value can be calculated using the method introduced in Hansen Solubility Parameters A User's Handbook, 2nd Ed (CRCPless).
Further, the SP value of an organic compound can be estimated from the molecular structure of the organic compound. Specifically, it can be calculated using simulation software (for example, “HSPiP” (http://www.hansen-solubility.com)) that can calculate the SP value from the SMILE equation. In this simulation software, Hansen SOLUBILITY PARAMETERS A User's Handbook Second Edition, Charles M. et al. The SP value is obtained based on the theory described in Hansen.

Although it does not specifically limit as a monomer used in order to prepare the polymer of a core part, For example, what the electrolyte solution swelling degree of the polymer becomes the said range can be selected suitably, and can be used. Examples of such monomers include vinyl chloride monomers such as vinyl chloride and vinylidene chloride; vinyl acetate monomers such as vinyl acetate; styrene, α-methylstyrene, styrenesulfonic acid, butoxystyrene, Aromatic vinyl monomers such as vinylnaphthalene; vinylamine monomers such as vinylamine; vinylamide monomers such as N-vinylformamide and N-vinylacetamide; monomers having a carboxylic acid group, sulfonic acid groups Monomers having acid groups, monomers having phosphoric acid groups, monomers having hydroxyl groups, etc .; (meth) acrylic acid derivatives such as 2-hydroxyethyl methacrylate; methyl acrylate, acrylic acid (Meth) acrylic acid ester monomers such as ethyl, methyl methacrylate, ethyl methacrylate, 2-ethylhexyl acrylate; (Meth) acrylamide monomers such as acrylamide and methacrylamide; (meth) acrylonitrile monomers such as acrylonitrile and methacrylonitrile; 2- (perfluorohexyl) ethyl methacrylate, 2- (perfluorobutyl) ethyl acrylate and the like Fluorine-containing (meth) acrylate monomers; maleimides; maleimide derivatives such as phenylmaleimide; diene monomers such as 1,3-butadiene and isoprene; Moreover, these may be used individually by 1 type and may be used in combination of 2 or more types.
In the present specification, “(meth) acrylo” means acrylo and / or methacrylo.

  Among the above monomers, it is preferable to use a (meth) acrylic acid ester monomer or a (meth) acrylonitrile monomer as a monomer used for preparing the core polymer. It is more preferable to use an acrylate monomer. That is, the polymer of the core part preferably contains a (meth) acrylic acid ester monomer unit or a (meth) acrylonitrile monomer unit, and more preferably contains a (meth) acrylic acid ester monomer unit. It is particularly preferred that it contains a monomer unit derived from methyl methacrylate. Thereby, the swelling degree of the polymer can be easily controlled, and the ion diffusibility of the adhesive layer using the particulate binder A can be further enhanced.

  Further, the ratio of the (meth) acrylic acid ester monomer unit in the polymer of the core part is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and preferably 98%. It is not more than mass%, more preferably not more than 97 mass%, still more preferably not more than 95 mass%. By setting the ratio of the (meth) acrylic acid ester monomer unit to be equal to or higher than the lower limit of the above range, the ion diffusibility of the adhesive layer can be increased and the low-temperature output characteristics of the secondary battery can be further improved. Moreover, by making the ratio of the (meth) acrylic acid ester monomer unit below the upper limit of the above range, the adhesiveness of the adhesive layer in the electrolyte solution is improved, and the high-temperature cycle characteristics of the secondary battery are further improved. be able to.

  Further, the polymer of the core part may include an acid group-containing monomer unit. Here, as the acid group-containing monomer, a monomer having an acid group, for example, a monomer having a carboxylic acid group, a monomer having a sulfonic acid group, a monomer having a phosphoric acid group, and And monomers having a hydroxyl group. Specifically, examples of the acid group-containing monomer include monomers similar to those described above in the section “Particulate Binder A as Non-Composite Polymer”.

Among these, as the acid group-containing monomer, a monomer having a carboxylic acid group is preferable, among which monocarboxylic acid is preferable, and (meth) acrylic acid is more preferable.
Moreover, an acid group containing monomer may be used individually by 1 type, and may be used in combination of 2 or more types.

  Further, the ratio of the acid group content body unit in the polymer of the core part is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 3% by mass or more, and preferably 20% by mass. Hereinafter, it is more preferably 10% by mass or less, and further preferably 7% by mass or less. By keeping the ratio of the acid group-containing body unit in the above range, when preparing the particulate binder A, the dispersibility of the polymer in the core part is improved, and the core part is compared with the outer surface of the polymer in the core part. It is possible to easily form a shell portion that partially covers the outer surface of the.

  Moreover, it is preferable that the polymer of a core part contains the crosslinkable monomer unit in addition to the said monomer unit. Specifically, as the crosslinkable monomer capable of forming a crosslinkable monomer unit, the same amount as the monomer described above in the section “Particulate Binder A as Non-Composite Polymer” is used. The body is mentioned.

  Among these, ethylene glycol dimethacrylate, allyl glycidyl ether, and glycidyl methacrylate are preferable, and ethylene glycol dimethacrylate is more preferable from the viewpoint of easily controlling the degree of electrolyte solution swelling of the polymer in the core portion. Moreover, these may be used individually by 1 type and may be used in combination of 2 or more types.

  Here, generally, when the proportion of the crosslinkable monomer unit in the polymer increases, the degree of swelling of the electrolyte solution of the polymer tends to decrease. Therefore, the ratio of the crosslinkable monomer unit is preferably determined in consideration of the type and amount of the monomer used. The specific ratio of the crosslinkable monomer unit in the polymer of the core part is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and further preferably 0.5% by mass or more. Preferably it is 7 mass% or less, More preferably, it is 6 mass% or less, More preferably, it is 4.5 mass% or less. By setting the ratio of the crosslinkable monomer unit to be equal to or higher than the lower limit of the above range, the adhesiveness of the adhesive layer in the electrolytic solution can be improved and the high-temperature cycle characteristics can be further improved. In addition, by setting the ratio of the crosslinkable monomer unit to be equal to or less than the upper limit of the above range, the polymerization stability during the preparation of the particulate binder A is ensured, and the obtained particulate binder A is preferably used. It can be in the form of particles.

Further, the glass transition temperature of the polymer of the core part is preferably 0 ° C. or higher, more preferably 50 ° C. or higher, further preferably 80 ° C. or higher, preferably 150 ° C. or lower, more preferably 140 ° C. or lower, still more preferably. Is 130 ° C. or lower. By setting the glass transition temperature of the polymer in the core part to be equal to or higher than the lower limit of the above range, the low temperature output characteristics of the secondary battery can be further improved. Moreover, the adhesiveness of the particulate binder A can further be improved by setting the glass transition temperature of the polymer in the core part to be equal to or lower than the upper limit of the above range.
The “glass transition temperature” of the polymer in the core portion can be measured using the method described in the examples of the present specification.

  Furthermore, the diameter of the core part is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more, particularly preferably 80% with respect to 100% of the volume average particle diameter of the particulate binder A. Or more, preferably 99% or less, more preferably 98.5% or less, and still more preferably 98% or less. By making the diameter of the core part equal to or greater than the lower limit of the above range, the ion diffusibility of the adhesive layer can be enhanced. On the other hand, the adhesiveness of the adhesive layer can be improved by setting the diameter of the core portion to be equal to or less than the upper limit of the above range.

  Here, the diameter of the core part can be measured as the volume average particle diameter D50 of the particulate polymer before forming the shell part obtained in the production process of the particulate binder A. The particulate polymer before forming such a shell portion corresponds to the particulate polymer constituting the core portion. In addition, the volume average particle diameter D50 of the particulate polymer before forming the shell portion can be measured in the same manner as the volume average particle diameter D50 of the particulate binder A as the non-composite polymer.

-Shell part-
The shell part of the particulate binder A is preferably made of a polymer having a predetermined electrolyte solution swelling degree smaller than the electrolyte solution swelling degree of the core part. Further, the shell portion of the particulate binder A is preferably made of the polymer A described above.
Here, the degree of swelling of the electrolyte of the polymer of the shell part is preferably more than 1 time, more preferably 1.1 times or more, further preferably 1.2 times or more, and 4 times. Or less, more preferably 3.5 times or less, and even more preferably 3 times or less. By making the electrolyte solution swelling degree of the polymer of the shell part equal to or higher than the lower limit of the above range, the high temperature cycle characteristics of the secondary battery can be further improved. Further, by making the electrolyte solution swelling degree of the polymer of the shell part below the upper limit of the above range, the adhesion property of the adhesive layer in the electrolyte solution can be improved, and the high temperature cycle characteristics of the secondary battery can be further improved. it can.

  Here, as the electrolytic solution used for measuring the degree of electrolytic solution swelling of the polymer in the shell portion, the same electrolytic solution used for measuring the degree of electrolytic solution swelling of the polymer in the core portion is used.

And the electrolyte solution swelling degree of the polymer of a shell part can be specifically measured as follows.
First, the polymer of the shell part of the particulate binder A is prepared. For example, in the preparation of the particulate binder A, using the monomer composition used for forming the shell portion instead of the monomer composition used for forming the core portion, A polymer is produced.
Thereafter, a film is produced from the polymer in the shell portion by the same method as the method for measuring the degree of swelling of the polymer in the core portion, a test piece is obtained from the film, and the degree of swelling S is measured.

  Here, as a method of adjusting the electrolyte solution swelling degree of the polymer of the shell part, for example, considering the SP value of the electrolyte solution, the kind and amount of the monomer for producing the polymer of the shell part Is appropriately selected.

  And as a monomer used in order to prepare the polymer of a shell part, the thing from which the electrolyte solution swelling degree of the polymer becomes the said range can be selected suitably, and can be used.

  Among these monomers, the monomer described above as the monomer that can be used for producing the polymer A is preferable as the monomer used for preparing the polymer of the shell portion. And the suitable range of the content ratio in the polymer of the shell part of the monomer unit derived from those monomers, and the reason that it is preferable to be within the range are as follows. This is the same as described above in the section “Particulate Binder A”.

Further, the preferable range of the glass transition temperature of the polymer of the shell part and the reason why it is preferable to be within the range are those described above in the section “Particulate Binder A as Non-Composite Polymer”. It should be noted that the “glass transition temperature” of the polymer in the shell part can be measured using the method described in the examples of the present specification.

  Furthermore, it is preferable that the shell portion has an average thickness that falls within a predetermined range with respect to the volume average particle diameter D50 of the particulate binder A. Specifically, the average thickness (core-shell ratio) of the shell part with respect to the volume average particle diameter D50 of the particulate binder A is preferably 1.5% or more, more preferably 3% or more, and further preferably 5% or more. Preferably, it is 40% or less, more preferably 30% or less, and still more preferably 20% or less. By making the average thickness of the shell part equal to or higher than the lower limit value of the above range, the adhesiveness of the adhesive layer in the electrolytic solution can be improved and the high temperature cycle characteristics can be further improved, and the upper limit value of the above range should be maintained. Thus, the low temperature output characteristics of the secondary battery can be further improved.

  Here, the average thickness of the shell portion is determined by observing the cross-sectional structure of the particulate binder A using a transmission electron microscope (TEM). Specifically, the maximum thickness of the shell part in the cross-sectional structure of the particulate binder A is measured using TEM, and the average of the maximum thicknesses of the shell parts of 20 or more arbitrarily selected particulate binders A is measured. The value is the average thickness of the shell part. However, the shell part is composed of polymer particles, and the particles constituting the shell part do not overlap in the radial direction of the particulate binder A, and the polymer particles are a single layer. When the shell part is constituted, the number average particle diameter of the particles constituting the shell part is defined as the average thickness of the shell part.

  Further, the form of the shell part is not particularly limited, but the shell part is preferably composed of particles of a polymer (specifically, polymer A). When the shell portion is composed of polymer particles, a plurality of particles constituting the shell portion may overlap in the radial direction of the particulate binder A. However, in the radial direction of the particulate binder A, it is preferable that the particles constituting the shell portion do not overlap each other, and the particles of the polymer constitute the shell portion as a single layer.

  Further, when the shell part is composed of polymer particles, the number average particle diameter of the particles constituting the shell part is preferably 10 nm or more, more preferably 20 nm or more, still more preferably 30 nm, preferably 200 nm. Hereinafter, it is more preferably 150 nm or less, and further preferably 100 nm or less. By keeping the number average particle diameter within the above range, the balance between ion diffusibility and adhesiveness can be improved.

  In addition, the number average particle diameter of the particles constituting the shell part is determined by observing the cross-sectional structure of the particulate binder A using a transmission electron microscope (TEM). Specifically, the longest diameter of the particles constituting the shell portion in the cross-sectional structure of the particulate binder A is measured, and the particles constituting the shell portions of 20 or more arbitrarily selected particulate binders A are measured. The average value of the longest diameters can be the number average particle diameter of the particles constituting the shell part.

-Preparation method of particulate binder A (core-shell structure)-
And the particulate binder A as a composite polymer having the above-described core-shell structure uses, for example, a polymer monomer in the core part and a polymer monomer in the shell part over time. It can prepare by changing the ratio of those monomers and polymerizing in steps. Specifically, the particulate binder A is prepared by a continuous multi-stage emulsion polymerization method and a multi-stage suspension polymerization method in which the polymer of the previous stage is sequentially coated with the polymer of the subsequent stage. be able to.

  Then, an example in the case of obtaining the particulate binder A which has the said core-shell structure by a multistage emulsion polymerization method below is shown.

  In the polymerization, according to a conventional method, as an emulsifier, for example, an anionic surfactant such as sodium dodecylbenzenesulfonate and sodium dodecylsulfate, a nonionic surfactant such as polyoxyethylene nonylphenyl ether and sorbitan monolaurate, or Cationic surfactants such as octadecylamine acetate can be used. Examples of the polymerization initiator include peroxides such as t-butylperoxy-2-ethylhexanoate, potassium persulfate, cumene peroxide, 2,2′-azobis (2-methyl-N- (2 An azo compound such as (hydroxyethyl) -propionamide) or 2,2′-azobis (2-amidinopropane) hydrochloride can be used.

  And as a polymerization procedure, the monomer and emulsifier which form a core part are mixed first, and the particulate polymer which comprises a core part is obtained by carrying out emulsion polymerization collectively. Furthermore, the particulate binder A having the core-shell structure described above can be obtained by polymerizing the monomer that forms the shell portion in the presence of the particulate polymer constituting the core portion.

  At this time, from the viewpoint of partially covering the outer surface of the core portion with the shell portion, the monomer that forms the polymer of the shell portion is divided into a plurality of times or continuously supplied to the polymerization system. Is preferred. The monomer that forms the polymer of the shell part is divided into a polymerization system or continuously supplied, whereby the polymer constituting the shell part is formed into particles, and these particles are bonded to the core part. Thereby, the shell part which covers a core part partially can be formed.

  Here, when the monomer for forming the polymer of the shell part is divided and supplied in multiple times, the particle diameter of the particles constituting the shell part and the It is possible to control the average thickness. In addition, when continuously supplying the monomer that forms the polymer of the shell part, by adjusting the supply amount of the monomer per unit time, the particle diameter of the particles constituting the shell part and the shell part It is possible to control the average thickness.

  Further, when a monomer having a low affinity for the polymerization solvent is used as a monomer for forming the polymer of the shell part, it tends to be easy to form a shell part that partially covers the core part. Therefore, when the polymerization solvent is water, the monomer that forms the polymer of the shell part preferably includes a hydrophobic monomer, and particularly preferably includes an aromatic vinyl monomer.

  Furthermore, when the amount of the emulsifier used for polymerization of the shell portion is reduced, it tends to be easy to form a shell portion that partially covers the core portion. Therefore, a shell part that partially covers the core part can also be formed by appropriately adjusting the amount of the emulsifier.

  In addition, the volume average particle diameter D50 of the particulate polymer constituting the core part, the volume average particle diameter D50 of the particulate binder A after forming the shell part, and the number average of the particles constituting the shell part The particle diameter can be adjusted to a desired range by adjusting, for example, the amount of emulsifier and the amount of monomer.

  Further, the average ratio of the outer surface of the core part covered by the shell part corresponds to the volume average particle diameter D50 of the particulate polymer constituting the core part, for example, the amount of emulsifier and the weight of the shell part. The desired range can be obtained by adjusting the amount of the monomer forming the coalescence.

<Binders other than the particulate binder A>
Here, from the viewpoint of improving the flexibility of the adhesive layer and the adhesion in the electrolytic solution in a well-balanced manner, the composition for the non-aqueous secondary battery adhesive layer of the present invention is a binder other than the particulate binder A. It is preferable to contain a material, for example, a particulate binder other than the particulate binder A (hereinafter referred to as “particulate binder B”).

Examples of the particulate binder B that can be used in combination with the particulate binder A include known particulate binders that are water-insoluble and dispersible in water, for example, thermoplastic elastomers. And as a thermoplastic elastomer, a conjugated diene polymer and an acrylic polymer are preferable, and an acrylic polymer is more preferable.
Here, the conjugated diene polymer refers to a polymer containing a conjugated diene monomer unit, and specific examples of the conjugated diene polymer include aromatic vinyl monomers such as styrene-butadiene copolymer (SBR). Examples thereof include a polymer containing a monomer unit and an aliphatic conjugated diene monomer unit. Moreover, an acrylic polymer refers to the polymer containing a (meth) acrylic acid ester monomer unit.
In addition, these particulate binder B may be used individually by 1 type, and may be used in combination of 2 or more types.

  In the acrylic polymer as the particulate binder B, the content ratio of the (meth) acrylic acid ester monomer unit is preferably 20% by mass or more, more preferably 30% by mass or more, more preferably 40% by mass. Or more, preferably 90% by mass or less, more preferably 85% by mass or less, and still more preferably 80% by mass or less. The monomer unit other than the (meth) acrylate monomer unit contained in the acrylic polymer as the particulate binder B is not particularly limited, but the hydroxyl group-containing unit in the particulate binder B is not particularly limited. The content ratio of the monomer unit is preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 1% by mass or less. By setting the content ratio of the hydroxyl group-containing monomer unit to 5% by mass or less, dehydration condensation between the particulate binder A and the particulate binder B is suppressed, and the particulate binder A is used as a base material. Can be adhered well.

Further, the glass transition temperature of the polymer constituting the particulate binder B is preferably −100 ° C. or higher, more preferably −50 ° C. or higher, preferably 25 ° C. or lower, more preferably 10 ° C. or lower. Preferably it is 0 degrees C or less. By setting the glass transition temperature of the particulate binder B to be equal to or higher than the lower limit of the above range, the flexibility of the adhesive layer can be increased. Moreover, the adhesiveness in the electrolyte solution of a contact bonding layer can further be improved by making a glass transition temperature below into the upper limit of the said range.
The “glass transition temperature” of the particulate binder B can be measured using the method described in the examples of the present specification.

  Furthermore, the volume average particle diameter D50 of the particulate binder B is preferably 0.1 μm or more and 0.5 μm or less. By making the volume average particle diameter D50 of the particulate binder B equal to or greater than the lower limit of the above range, the dispersibility of the particulate binder B can be enhanced. Moreover, the adhesiveness in the electrolyte solution of a contact bonding layer can further be improved by making volume average particle diameter D50 below into the upper limit of the said range. The volume average particle diameter D50 of the particulate binder B can be measured in the same manner as the volume average particle diameter D50 of the particulate binder A.

  And the compounding quantity of the particulate binder B in the composition for contact bonding layers is preferably 1 part by mass or more, more preferably 2 parts by mass or more per 100 parts by mass of the particulate binder A. Moreover, it is preferable that it is 15 mass parts or less, and it is more preferable that it is 10 mass parts or less. By setting the content of the particulate binder B to be equal to or higher than the lower limit of the above range, it is possible to ensure a good balance between the adhesiveness of the adhesive layer in the electrolyte and the flexibility of the adhesive layer. Further, by making the content of the particulate binder B not more than the upper limit of the above range, it is possible to suppress the ion diffusibility of the adhesive layer from being lowered and to secure the low temperature output characteristics of the secondary battery. . In addition, the adhesiveness of the adhesive layer in the electrolytic solution can be ensured without impairing the adhesion improving function of the particulate binder A.

  The particulate binder B can be produced in the same manner as the particulate binder A as the non-composite polymer.

<Other ingredients>
The composition for non-aqueous secondary battery adhesive layers may contain any other component in addition to the components described above. Examples of these other components include known additives such as a wetting agent, a thickener, and an electrolytic solution additive. Moreover, these other components may be used individually by 1 type, and may be used in combination of 2 or more types.

<Preparation method of composition for non-aqueous secondary battery adhesive layer>
The method for preparing the composition for the adhesive layer is not particularly limited, but usually the particulate binder A, water as a dispersion medium, and the particulate binder B and other components used as necessary. Are mixed to prepare an adhesive layer composition. Although the mixing method is not particularly limited, in order to disperse each component efficiently, mixing is usually performed using a disperser as a mixing device.
The disperser is preferably an apparatus capable of uniformly dispersing and mixing the above components. Examples include a ball mill, a sand mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, and a planetary mixer. In addition, from the viewpoint of adding a high dispersion share, a high dispersion apparatus such as a bead mill, a roll mill, or a fill mix is also included.

The pH of the resulting adhesive layer composition is not particularly limited, but is preferably 3 or more, more preferably 3.5 or more, still more preferably 4 or more, preferably 6 or less, more preferably 5.5. Hereinafter, it is more preferably 5 or less. When the pH of the composition for the adhesive layer is within the above range, the reactivity of the alkoxysilyl group (or silanol group) of the particulate binder A is reduced, and the stability (storability) of the composition for the adhesive layer is reduced. Can be improved. As a result, when the composition for an adhesive layer is dried on a substrate, the resulting adhesive layer can be suitably adhered to the substrate.
In addition, pH of the composition for contact bonding layers can be adjusted with a known method.

(Adhesive layer for non-aqueous secondary batteries)
The adhesive layer for non-aqueous secondary batteries of the present invention can be formed on an appropriate substrate using the above-described composition for non-aqueous secondary battery adhesive layers. This adhesive layer exhibits excellent adhesiveness in the electrolytic solution, and can exhibit excellent electrical characteristics in the secondary battery. Note that the adhesive layer may be provided on one side of the substrate, or may be provided on both sides of the substrate.
The ratio of the particulate binder A contained in the adhesive layer for non-aqueous secondary batteries is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and particularly preferably 90%. It is at least mass%, and is usually at most 100 mass%.

<Base material>
The base material for forming the adhesive layer is not particularly limited. For example, when the adhesive layer is used as a member constituting a part of the separator, a separator base material can be used as the base material. When an adhesive layer is used as a member constituting a part of the electrode, an electrode substrate can be used as the substrate.

The separator base material for forming the adhesive layer is not particularly limited, and for example, those described in JP 2012-204303 A can be used.
The electrode base material (positive electrode base material and negative electrode base material) for forming the adhesive layer is not particularly limited, and examples thereof include an electrode base material in which an electrode mixture layer is formed on a current collector. Here, the current collector, the components in the electrode mixture layer (for example, the electrode active material (positive electrode active material, negative electrode active material) and the electrode mixture layer binder (positive electrode mixture layer binder, negative electrode composite) The material layer binder) and the like, and the method for forming the electrode mixture layer on the current collector may be known ones, for example, those described in JP2013-145663A be able to.

Moreover, it is preferable that these separator base material and electrode base material are further provided with a porous film layer for the purpose of improving heat resistance and strength. The porous membrane layer is not particularly limited, and a slurry composition for porous membrane layers obtained by dissolving or dispersing non-conductive particles, a binder for porous membrane layers, and a thickener in a solvent such as water is dried. Are formed.
Here, the non-conductive particles and the binder for the porous membrane layer are not particularly limited, and examples of the non-conductive particles include those described in JP2013-145663A. As the binder, from the viewpoint of flexibility and adhesiveness of the porous membrane layer, for example, the above-mentioned particulate binder B is preferably exemplified. Moreover, as a thickener, a known thickener can be used.
In addition, the method of drying the slurry composition for porous membrane layers and providing a porous membrane layer on the surface of a separator base material or an electrode base material is not specifically limited, It is possible to employ | adopt a known method.

Here, the content of the binder for the porous membrane layer in the porous membrane layer is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, preferably 100 parts by mass of the nonconductive particles. It is 10 mass parts or less, More preferably, it is 5 mass parts or less. If the content of the binder for the porous membrane layer is not less than the lower limit of the above range, the adhesion between the adhesive layer in the electrolyte and the porous membrane layer (that is, the substrate having the porous membrane layer) is improved. It can be further improved, and the low temperature output characteristics of the secondary battery can be further improved as long as it is not more than the upper limit of the above range. Further, the content of the thickener in the porous membrane layer is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, preferably 3 parts by mass per 100 parts by mass of the non-conductive particles. Hereinafter, it is more preferably 2 parts by mass or less. If the content of the thickener is not less than the lower limit of the above range, the adhesion between the adhesive layer and the porous membrane layer (that is, the base material provided with the porous membrane layer) in the electrolytic solution is further improved. If the amount is not more than the upper limit of the above range, the amount of moisture brought into the secondary battery can be reduced.
Here, the non-conductive particles in the porous membrane layer, the binder for the porous membrane layer, and the thickener were contained in the slurry composition for the porous membrane layer, and their presence in the porous membrane layer. The ratio is usually the same as the abundance ratio in the slurry composition for the porous membrane layer.
In addition, the ratio of the nonelectroconductive particle in a porous membrane layer becomes like this. Preferably it is 50 mass% or more, More preferably, it is 70 mass% or more, More preferably, it is 90 mass% or more.

  Here, as a base material (electrode base material, separator base material) for forming the adhesive layer, a base material provided with a functional layer containing inorganic oxide particles on the surface is preferable. Examples of the functional layer containing inorganic oxide particles include a porous film layer containing inorganic oxide particles as non-conductive particles and an electrode mixture layer containing inorganic oxide particles as an electrode active material.

Examples of the inorganic oxide particles used as the non-conductive particles of the porous membrane layer include aluminum oxide (alumina), hydrated aluminum oxide (boehmite), silicon oxide, magnesium oxide (magnesia), calcium oxide, titanium oxide ( Titania), BaTiO ₃ , ZrO, alumina-silica composite oxide and the like.
Examples of the inorganic oxide particles used as the electrode active material of the electrode mixture layer include lithium cobaltate and lithium manganate.
By supplying a composition for an adhesive layer on the functional layer of the base material provided with a functional layer containing such inorganic oxide particles on the surface and drying it to form an adhesive layer, it is bonded by heating at the time of drying. The particulate binder A of the layer composition and the inorganic oxide particles in the functional layer are well dehydrated and condensed, and adhesion between the adhesive layer and the functional layer (that is, adhesion between the adhesive layer and the substrate) ) Can be secured.

The isoelectric point (pH) of the inorganic oxide particles in the functional layer is preferably 5 or more, more preferably 6 or more, still more preferably 7 or more, preferably 10 or less, more preferably 9.5 or less. More preferably, it is 9 or less. When the pH of the isoelectric point of the inorganic oxide particles is not less than the lower limit of the above range, dehydration condensation between the particulate binder A and the inorganic oxide particles is facilitated, and the adhesive layer and the functional layer are more Good adhesion can be achieved. Moreover, when the pH of the isoelectric point of the inorganic oxide particles is not more than the upper limit of the above range, the amount of moisture brought into the secondary battery can be reduced.
Here, the isoelectric point (pH) of the inorganic oxide particles can be measured by a method defined in JIS R1638.

  Further, the isoelectric point (pH) of the inorganic oxide particles is preferably larger than the pH of the adhesive layer composition. When the isoelectric point of the inorganic oxide particles exceeds the pH of the adhesive layer composition, when the adhesive layer composition is applied onto the functional layer containing the inorganic oxide particles, the vicinity of the interface with the functional layer This is because the pH of the composition for the adhesive layer in the layer increases and the dehydration condensation between the particulate binder A and the inorganic oxide particles is promoted. From the viewpoint of enhancing the adhesion of the adhesive layer to the functional layer, the value obtained by subtracting the pH of the composition for the adhesive layer from the isoelectric point (pH) of the inorganic oxide particles is preferably 1 or more. More preferably, it is more preferably 3.

  The adhesive layer for non-aqueous secondary battery is not particularly limited, but a base material (electrode base material) provided with a functional layer using the method for producing an adhesive layer for non-aqueous secondary battery of the present invention described in detail below. Or a separator base material) is preferably provided adjacent to the functional layer.

(Method for producing adhesive layer for non-aqueous secondary battery)
The method for producing a non-aqueous secondary battery adhesive layer according to the present invention includes a step of supplying a non-aqueous secondary battery adhesive layer composition onto a functional layer containing inorganic oxide particles (supply step), And a step (drying step) of drying the composition for a non-aqueous secondary battery adhesive layer supplied to the.

In the supplying step, the method for supplying the adhesive layer composition onto the functional layer on the surface of the substrate is not particularly limited, and the adhesive layer composition may be applied on the functional layer, or the group having the functional layer. The material may be immersed in the adhesive layer composition. Among these, the former application method is preferable because the film thickness of the adhesive layer can be easily controlled.
The method for applying the adhesive layer composition onto the functional layer is not particularly limited. For example, spray coating method, doctor blade method, reverse roll method, direct roll method, gravure method, extrusion method, brush coating method. And the like. Of these, the gravure method and the spray coating method are preferable from the viewpoint of forming a thin adhesive layer.

  In the drying step, the method for drying the composition for the adhesive layer on the functional layer is not particularly limited, and a known method can be used. For example, drying with warm air, hot air, low-humidity air, vacuum drying, infrared rays, A drying method by irradiation with an electron beam or the like is mentioned. The drying conditions are not particularly limited, but the drying temperature is preferably 30 to 80 ° C., and the drying time is preferably 30 seconds to 10 minutes.

  The thickness of the formed adhesive layer is preferably 0.01 μm or more, more preferably 0.1 μm or more, further preferably 0.5 μm or more, preferably 20 μm or less, more preferably 10 μm or less, and still more preferably 5 μm or less. When the thickness of the adhesive layer is not less than the lower limit value of the above range, the strength of the adhesive layer can be sufficiently secured, and when it is not more than the upper limit value of the above range, the ion diffusibility of the adhesive layer can be ensured. The low temperature output characteristics of the secondary battery can be further improved.

(Non-aqueous secondary battery material)
The non-aqueous secondary battery member of the present invention includes a functional layer containing inorganic oxide particles and an adhesive layer for a non-aqueous secondary battery disposed adjacent to the functional layer. Can be mentioned.
(1) A separator in which an adhesive layer is disposed adjacent to a porous membrane layer containing inorganic oxide particles (non-conductive particles);
(2) An electrode in which an adhesive layer is disposed adjacent to a porous membrane layer containing inorganic oxide particles (non-conductive particles);
(3) An electrode in which an adhesive layer is disposed adjacent to an electrode mixture layer containing inorganic oxide particles (electrode active material);
Since such a non-aqueous secondary battery member includes the adhesive layer for a non-aqueous secondary battery of the present invention, it is particularly excellent in adhesion between the adhesive layer and the functional layer, and also excellent in secondary battery. Characteristic can be exhibited. And the non-aqueous secondary battery member of this invention can be manufactured by providing an contact bonding layer on the base material which has a functional layer, for example using the manufacturing method of the contact bonding layer for non-aqueous secondary batteries mentioned above. it can.

(Non-aqueous secondary battery)
The non-aqueous secondary battery of the present invention includes the above-described adhesive layer for a non-aqueous secondary battery of the present invention and / or the non-aqueous secondary battery member of the present invention. More specifically, the non-aqueous secondary battery of the present invention includes a positive electrode, a negative electrode, a separator, and an electrolyte, and the above-described adhesive layer for a non-aqueous secondary battery of the present invention is a battery member. And at least one of the separators.
Since the nonaqueous secondary battery of the present invention includes the adhesive layer for a nonaqueous secondary battery of the present invention, it is excellent in electrical characteristics such as high temperature cycle characteristics and low temperature output characteristics.

<Positive electrode, negative electrode and separator>
At least one of the positive electrode, the negative electrode, and the separator used in the secondary battery of the present invention has an adhesive layer. Specifically, as a positive electrode and a negative electrode having an adhesive layer, an electrode in which an adhesive layer is provided on an electrode substrate can be used. Also, as a separator having an adhesive layer, A separator provided with an adhesive layer can be used. In addition, as an electrode base material and a separator base material, the thing similar to what was mentioned by the term of the "base material" can be used.
Moreover, as a positive electrode, a negative electrode, and a separator which do not have an adhesive layer, it does not specifically limit, The electrode which consists of an electrode base material mentioned above, and the separator which consists of a separator base material mentioned above can be used.

<Electrolyte>
As the electrolytic solution, an organic electrolytic solution in which a supporting electrolyte is dissolved in an organic solvent is usually used. As the supporting electrolyte, for example, a lithium salt is used in a lithium ion secondary battery. Examples of the lithium salt include LiPF ₆ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , LiAlCl ₄ , LiClO ₄ , CF ₃ SO ₃ Li, C ₄ F ₉ SO ₃ Li, CF ₃ COOLi, (CF ₃ CO) ₂ NLi , (CF ₃ SO ₂ ) ₂ NLi, (C ₂ F ₅ SO ₂ ) NLi, and the like. Among these, LiPF ₆ , LiClO ₄ , and CF ₃ SO ₃ Li are preferable because they are easily dissolved in a solvent and exhibit a high degree of dissociation. In addition, electrolyte may be used individually by 1 type and may be used in combination of 2 or more types. Usually, the lithium ion conductivity tends to increase as the supporting electrolyte having a higher degree of dissociation is used, so that the lithium ion conductivity can be adjusted depending on the type of the supporting electrolyte.

The organic solvent used in the electrolytic solution is not particularly limited as long as it can dissolve the supporting electrolyte. For example, in a lithium ion secondary battery, dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC). Carbonates such as propylene carbonate (PC), butylene carbonate (BC), and methyl ethyl carbonate (MEC); esters such as γ-butyrolactone and methyl formate; ethers such as 1,2-dimethoxyethane and tetrahydrofuran; sulfolane, Sulfur-containing compounds such as dimethyl sulfoxide; are preferably used. Moreover, you may use the liquid mixture of these solvents. Among these, carbonates are preferable because they have a high dielectric constant and a wide stable potential region. Usually, the lower the viscosity of the solvent used, the higher the lithium ion conductivity tends to be, so the lithium ion conductivity can be adjusted depending on the type of solvent.
The concentration of the electrolyte in the electrolytic solution can be adjusted as appropriate. Moreover, you may add a known additive to electrolyte solution.

<Method for producing non-aqueous secondary battery>
A non-aqueous secondary battery, for example, stacks a positive electrode and a negative electrode through a separator, and rolls or folds this as necessary into a battery container, and injects an electrolyte into the battery container to seal it. Can be manufactured. Of the positive electrode, the negative electrode, and the separator, at least one member is a member with an adhesive layer. Here, an expanded metal, an overcurrent prevention element such as a fuse or a PTC element, a lead plate, or the like may be placed in the battery container as necessary to prevent an increase in pressure inside the battery or overcharge / discharge. The shape of the battery may be any of a coin shape, a button shape, a sheet shape, a cylindrical shape, a square shape, a flat shape, and the like.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the following description, “%” and “part” representing amounts are based on mass unless otherwise specified.
In addition, in a polymer produced by copolymerizing a plurality of types of monomers, the proportion of the structural unit formed by polymerizing a certain monomer in the polymer is usually that unless otherwise specified. This coincides with the ratio (preparation ratio) of the certain monomer in the total monomers used for polymerization of the polymer.
In Examples and Comparative Examples, the degree of swelling of the electrolyte solution of the polymer constituting the particulate binder A, the average ratio (coverage) at which the outer surface of the core part of the particulate binder A is covered by the shell, Average thickness (core shell ratio) of the shell portion of the binder A, the volume average particle diameter D50 of each particle, the glass transition temperature of each polymer, the total water content of the adhesive layer and the porous membrane layer, and electrolysis of the adhesive layer Adhesion in liquid (after immersion and after cycling), swelling resistance, high temperature cycle characteristics and low temperature output characteristics of the secondary battery were measured and evaluated by the following methods.

<Swelling degree of electrolytic solution of polymer constituting particulate binder A>
Polymer used as a measurement sample under polymerization conditions similar to the polymerization conditions of the core part and the shell part using the monomer composition used for the preparation of the core part and the shell part of the particulate binder A (core-shell structure) Aqueous dispersions of the polymer in the core part and the polymer in the shell part were prepared. Further, an aqueous dispersion of the particulate binder A (non-composite polymer) was prepared.
Next, the above-mentioned aqueous dispersion is put in a petri dish made of polytetrafluoroethylene, dried at a temperature of 60 ° C. for 72 hours, then taken out of the petri dish and hot-pressed for 5 minutes under the conditions of 100 ° C. and 20 kg / cm ² , A film with a thickness of 0.5 mm was produced. And the obtained film was cut | judged to 1 square cm, and the test piece was obtained. The weight of this test piece was measured and designated as W0. The test piece was immersed in the electrolytic solution at a temperature of 60 ° C. for 72 hours. Then, the test piece was taken out from the electrolytic solution, the electrolytic solution on the surface of the test piece was wiped off, and the weight W1 of the test piece after immersion was measured. Then, using these weights W0 and W1, the degree of swelling S (times) was calculated as S = W1 / W0.
As the electrolytic solution, a mixed solvent of ethylene carbonate, diethyl carbonate and vinylene carbonate (volume mixing ratio EC / DEC / VC = 68.5 / 30 / 1.5; SP value 12.7 (cal / cm ³ ) ^{1 / 2} ), a supporting electrolyte in which LiPF ₆ was dissolved at a concentration of 1 mol / L was used.
<Average ratio (coverage) of outer surface of core part of particulate binder A covered with shell part>
The particulate binder A (core-shell structure) is sufficiently dispersed in a visible light curable resin (“D-800” manufactured by JEOL Ltd.) and then embedded to contain the particulate binder A. Block pieces were prepared. Next, the block piece was cut into a thin piece having a thickness of 100 nm with a microtome equipped with a diamond blade to prepare a measurement sample. Thereafter, the measurement sample was dyed using ruthenium tetroxide.
Next, the dyed measurement sample was set in a transmission electron microscope (“JEM-3100F” manufactured by JEOL Ltd.), and the cross-sectional structure of the particulate binder A was photographed at an acceleration voltage of 80 kV. The magnification of the electron microscope was set so that the cross section of one particulate binder A could enter the visual field. Then, in the cross-sectional structure of the photographed particulate binder A, the circumference D1 of the core part and the length D2 of the part where the outer surface of the core part abuts on the shell part are measured. From (1), the ratio Rc of the outer surface of the core part of the particulate binder A covered by the shell part was calculated.
Covering ratio Rc (%) = (D2 / D1) × 100 (1)
Then, the covering ratio Rc is measured for 20 arbitrarily selected particulate binders A, the average value is calculated, and the average ratio (covering ratio) at which the outer surface of the core part is covered by the shell part did.
<Average thickness of shell part of particulate binder A (core shell ratio)>
The average thickness of the shell part of the particulate binder A (core-shell structure) was measured by the following procedure.
In the case where the shell portion is composed of polymer particles, the cross-sectional structure of the particulate binder A was observed with a transmission electron microscope in the same manner as in the method for measuring the coverage. Then, from the observed cross-sectional structure of the particulate binder A, the longest diameter of the polymer particles constituting the shell portion was measured. The longest diameter of the polymer particles constituting the shell portion was measured for 20 arbitrarily selected particulate binders A, and the average value of the longest diameters was taken as the average thickness of the shell portion.
Further, when the shell portion had a shape other than the particles, the cross-sectional structure of the particulate binder A was observed with a transmission electron microscope in the same manner as in the method for measuring the coverage. And the maximum thickness of the shell part was measured from the cross-sectional structure of the particulate binder A observed. For 20 arbitrarily selected particulate binders A, the maximum thickness of the shell portion was measured, and the average value of the maximum thickness was taken as the average thickness of the shell portion.
Then, the ratio of the average thickness of the shell part to the volume average particle diameter D50 of the particulate binder A is obtained by dividing the measured average thickness of the shell part by the volume average particle diameter D50 of the particulate binder A. The core-shell ratio (unit:%) was calculated, and the average thickness of the shell portion was evaluated.
<Volume average particle diameter D50>
The volume average particle diameter D50 of each particle is a particle diameter measured by a laser diffraction particle size distribution measuring apparatus (“SALD-3100” manufactured by Shimadzu Corporation) of an aqueous dispersion adjusted to a solid content concentration of 15% by mass. In the distribution, the particle diameter was such that the cumulative volume calculated from the small diameter side was 50%.
<Glass transition temperature (Tg)>
In the measurement of the glass transition temperature of the polymer of the core part and the polymer of the shell part of the particulate binder A (core-shell structure), the monomer composition used for the preparation of each polymer is used, Under the same polymerization conditions as the polymerization conditions for the coalescence, each of the aqueous dispersions containing the polymer to be the measurement sample was prepared, and the measurement sample obtained by drying the aqueous dispersion was used.
For measurement of the glass transition temperature of the particulate binder A (non-composite polymer) and the particulate binder B, a measurement sample obtained by drying the aqueous dispersion containing the obtained particulate binder. It was used.
Next, using a differential thermal analysis measuring device (product name “EXSTAR DSC6220” manufactured by SII Nano Technology, Inc.), 10 mg of the above-mentioned measurement sample is weighed on an aluminum pan, and an empty aluminum pan is used as a reference. The DSC curve was measured in the range of −100 ° C. to 500 ° C. at a rate of temperature increase of 10 ° C./min and at normal temperature and humidity. During this temperature rising process, the baseline immediately before the endothermic peak of the DSC curve where the differential signal (DDSC) becomes 0.05 mW / min / mg or more and the tangent line of the DSC curve at the first inflection point after the endothermic peak The glass transition temperature was determined from the intersection with.
<Total water content of adhesive layer and porous membrane layer>
In the same manner as in each example and comparative example, a laminate composed of a porous membrane layer and an organic separator was prepared, and then the organic separator was removed from the porous membrane layer to obtain a porous membrane layer that was an independent membrane. And it carried out similarly to each Example and the comparative example, and formed the contact bonding layer on the said porous membrane layer, and produced the laminated body which consists of an adhesion layer and a porous membrane layer. A laminate composed of the adhesive layer and the porous membrane layer was cut out in a size of 10 cm width × 10 cm length to obtain a test piece. The test piece was allowed to stand for 24 hours at a temperature of 25 ° C. and a humidity of 50%, and then the test piece was subjected to Karl Fischer method (JIS K-0068 (2001) water vaporization method, vaporization temperature 150 ° C.) using a coulometric titration moisture meter. The water content W was measured. The smaller this value, the smaller the amount of moisture brought into the secondary battery.
A: Moisture amount W is 500 ppm or less B: Moisture amount W is more than 500 ppm and less than 600 ppm C: Moisture amount W is more than 600 ppm and less than 700 ppm D: Moisture amount W is more than 700 ppm <Adhesiveness of the adhesive layer in the electrolyte (after immersion) )>
In the same manner as in each example and comparative example, a laminate composed of a porous membrane layer and an organic separator was prepared, and then the organic separator was removed from the porous membrane layer to obtain a porous membrane layer that was an independent membrane. And it carried out similarly to each Example and the comparative example, and formed the contact bonding layer on the said porous membrane layer, and produced the laminated body which consists of an adhesion layer and a porous membrane layer. A laminate composed of the adhesive layer and the porous membrane layer was cut out in a size of 10 cm wide × 10 cm long to obtain a test piece. This was heated at 60 ° C. for 72 hours with an electrolytic solution (a mixed solvent of ethylene carbonate, diethyl carbonate and vinylene carbonate (volume mixing ratio EC / DEC / VC = 68.5 / 30 / 1.5; SP value 12.7 (cal / cm ³ ) ^1/2 ) was soaked in LiPF ₆ as a supporting electrolyte at a concentration of 1 mol / L), and after wiping off the electrolyte, cellophane tape was applied to the surface of the adhesive layer. At this time, a cellophane tape defined in JIS Z1522 was used. The cellophane tape was fixed on a horizontal test bench. Then, the stress when one end of the porous membrane layer was pulled vertically upward at a pulling speed of 50 mm / min and peeled was measured. This measurement was performed 3 times, the average value of stress was calculated | required, and the said average value was made into peel strength P1. It shows that the adhesive layer has the outstanding adhesiveness in electrolyte solution, so that the measured peel strength P1 is large.
A: Peel strength P1 is 20 N / m or more B: Peel strength P1 is 15 N / m or more and less than 20 N / m C: Peel strength P1 is less than 15 N / m <Swelling resistance of secondary battery>
The manufactured wound lithium ion secondary battery having a discharge capacity of 1000 mAh was allowed to stand for 24 hours in an environment at 25 ° C., and then charged at 4.4 V, 0.1 C, 3 V, 0 in an environment at 25 ° C. The charge / discharge operation was performed with a discharge of 1 C. Thereafter, the wound lithium ion secondary battery was immersed in liquid paraffin, and its volume V0 was measured. After measuring the volume V0, it is taken out from the liquid paraffin, and the charging / discharging operation is repeated in an environment of 60 ° C., and the wound lithium ion secondary battery after 1000 cycles is immersed in the liquid paraffin, and the volume V1 is determined. It was measured. And cell volume change rate (DELTA) V (%) = {(V1-V0) / V0} * 100 before and behind a cycle was computed, and the following reference | standard evaluated. It shows that the smaller the value of the volume change rate ΔV, the better the bulging resistance of the cell.
A: Volume change rate ΔV is less than 10% B: Volume change rate ΔV is 10% or more and less than 15% C: Volume change rate ΔV is less than 20% <High-temperature cycle characteristics of secondary battery>
The manufactured wound lithium ion secondary battery with a discharge capacity of 1000 mAh was allowed to stand in an environment of 25 ° C. for 24 hours. Next, in an environment of 25 ° C., charging and discharging operations were performed by charging at 4.4 V, 0.1 C, and discharging at 2.75 V, 0.1 C, and the initial capacity C0 was measured. Thereafter, the same charge / discharge operation was repeated under an environment of 60 ° C., and the capacity C1 after 1000 cycles was measured. Then, the capacity retention ratio ΔC (%) before and after the cycle = C1 / C0 × 100 was calculated and evaluated according to the following criteria. It shows that it is excellent in high temperature cycling characteristics, so that the value of capacity | capacitance maintenance factor (DELTA) C is large.
A: Capacity maintenance ratio ΔC is 85% or more B: Capacity maintenance ratio ΔC is 80% or more and less than 85% C: Capacity maintenance ratio ΔC is less than 80% <Adhesiveness of adhesive layer in electrolyte (after cycle)>
After the evaluation of the high-temperature cycle characteristics, the cell was disassembled, a laminate comprising the organic separator / porous membrane layer / adhesive layer / negative electrode in this order was taken out, and a cellophane tape was attached to the surface of the organic separator. At this time, a cellophane tape defined in JIS Z1522 was used. The cellophane tape was fixed on a horizontal test bench. Thereafter, the stress was measured when one end of the negative electrode was pulled vertically upward and pulled at a speed of 50 mm / min. This measurement was performed 3 times, the average value of stress was calculated | required, and the said average value was made into peel strength P2. It shows that the adhesive layer after a cycle has the outstanding adhesiveness in electrolyte solution, so that the measured peel strength P2 is large.
A: Peel strength P2 is 5 N / m or more B: Peel strength P2 is 3 N / m or more and less than 5 N / m C: Peel strength P2 is less than 3 N / m <Low-temperature output characteristics of secondary battery>
The manufactured wound lithium ion secondary battery with a discharge capacity of 1000 mAh was allowed to stand in an environment of 25 ° C. for 24 hours. Thereafter, 4.4 V, 0.1 C, and 5 hours of charging were performed in an environment of 25 ° C., and the voltage V0 at that time was measured. Thereafter, a discharge operation was performed at a discharge rate of 1 C in an environment of −10 ° C., and the voltage V1 15 seconds after the start of discharge was measured. And the voltage change shown by (DELTA) V = V0-V1 was calculated | required, and the following reference | standard evaluated. The smaller this voltage change, the better the low-temperature output characteristics.
A: Voltage change ΔV is 500 mV or less B: Voltage change ΔV is more than 500 mV and 700 mV or less C: Voltage change ΔV is more than 700 mV and 900 mV or less D: Voltage change ΔV is more than 900 mV

Example 1
<Preparation of particulate binder A (core shell structure)>
In a 5 MPa pressure vessel with a stirrer, 75 parts of methyl methacrylate as a (meth) acrylic acid ester monomer, 4 parts of methacrylic acid as an acid group-containing monomer, for forming the core part of the particulate binder A Add 1 part of ethylene glycol dimethacrylate as a crosslinkable monomer, 1 part of sodium dodecylbenzenesulfonate as an emulsifier, 150 parts of ion-exchanged water, and 0.5 part of potassium persulfate as a polymerization initiator. Then, the mixture was heated to 60 ° C. to initiate polymerization. When the polymerization conversion rate reaches 96%, 18 parts of styrene as an aromatic vinyl monomer and acid groups are subsequently used for forming a shell part (corresponding to polymer A) of the particulate binder A. 1 part of methacrylic acid as the containing monomer and 1 part of 3-methacryloxypropyltrimethoxysilane (product name “A-174” manufactured by Momentive Performance Materials) as the alkoxysilyl group-containing monomer The mixture was continuously added, and the polymerization was continued by heating to 70 ° C. When the polymerization conversion rate of all the added monomers reached 96%, the reaction was stopped by cooling to obtain an aqueous dispersion containing the particulate binder A.
And the coverage and core-shell ratio of the obtained particulate binder A, and the volume average particle diameter D50 were measured. Further, the degree of swelling of the electrolyte and the glass transition temperature of the polymer constituting the particulate binder A were also measured. The results are shown in Table 1 described later.
<Preparation of particulate binder B>
70 parts of ion-exchanged water, 0.15 part of sodium lauryl sulfate (product name “Emal 2F” manufactured by Kao Chemical Co., Ltd.) as an emulsifier and 0.5 part of ammonium persulfate are supplied to a reactor equipped with a stirrer. The gas phase portion was replaced with nitrogen gas, and the temperature was raised to 60 ° C.
On the other hand, in a separate container, 50 parts of ion-exchanged water, 0.5 part of sodium dodecylbenzenesulfonate as a dispersant, 45 parts of 2-ethylhexyl acrylate, 50 parts of styrene, 3 parts of itaconic acid, N-methylolacrylamide 1 And 1 part of allyl glycidyl ether were mixed to obtain a monomer mixture. This monomer mixture was continuously added to the reactor over 4 hours for polymerization. During the addition, the reaction was carried out at 60 ° C. After completion of the addition, the reaction was further terminated by stirring at 70 ° C. for 3 hours to prepare an aqueous dispersion containing the particulate binder B (acrylic polymer).
The obtained particulate binder B had a volume average particle diameter D50 of 0.15 μm and a glass transition temperature of −15 ° C.
<Manufacture of composition for adhesive layer>
8 parts water dispersion containing particulate binder B in solids equivalent to an aqueous dispersion containing particulate binder A (100 parts in solids equivalent), polyethylene glycol type surfactant (San Nopco) Product, product name “SN366”) 1 part was added and further diluted with ion-exchanged water to obtain a slurry-like composition for an adhesive layer having a solid content concentration of 30%. The pH of the adhesive layer composition was measured. The results are shown in Table 1 described later.
The supernatant liquid obtained by centrifuging the composition for the adhesive layer was analyzed by gas chromatography. As a result, alcohol (silanol group) derived from hydrolysis of 3-methacryloxypropyltrimethoxysilane was detected. It was confirmed that at least a part of the alkoxysilyl group contained in the binder B was hydrolyzed.

<Manufacture of slurry composition for porous membrane layer>
100 parts of alumina having an isoelectric point of 8.9 as non-conductive particles (“LS-256” manufactured by Nippon Light Metal Co., Ltd.), an acrylamide polymer having a carboxylic acid group introduced as a thickener (manufactured by Arakawa Chemical Co., Ltd., “ POLYSTORON (registered trademark) 117 ") in an aqueous dispersion containing 1.0 part in solids, and 3 parts in an aqueous dispersion of the particulate binder B as a binder for a porous membrane layer. Then, 0.2 part of a polyethylene glycol type surfactant (manufactured by San Nopco, “San Nopco SN wet 366”) was mixed to obtain a slurry composition for a porous membrane layer.
<Formation of porous membrane layer and adhesive layer, and separator comprising them>
The slurry composition for porous membrane layers was applied onto an organic separator made of polypropylene (product name “Celgard 2500” manufactured by Celgard) and dried at 50 ° C. for 1 minute. This operation was performed on both surfaces of the organic separator to obtain a separator base material having a porous film layer with a thickness of 2 μm on one side.
Furthermore, the composition for adhesive layers was apply | coated on the porous film layer of this separator base material, and it was made to dry at 50 degreeC for 1 minute. This operation was performed on both sides of the separator substrate to obtain a separator having an adhesive layer of 0.5 μm on each side.

<Preparation of negative electrode>
In a 5 MPa pressure vessel with a stirrer, 33 parts of 1,3-butadiene, 3.5 parts of itaconic acid, 63.5 parts of styrene, 0.4 part of sodium dodecylbenzenesulfonate as an emulsifier, 150 parts of ion-exchanged water and a polymerization initiator After adding 0.5 parts of potassium persulfate as a mixture and sufficiently stirring, the mixture was heated to 50 ° C. to initiate polymerization. When the polymerization conversion rate reached 96%, the reaction was stopped by cooling to obtain a mixture containing a particulate binder (SBR) for the negative electrode mixture layer. A 5% aqueous sodium hydroxide solution was added to the mixture containing the particulate binder and the pH was adjusted to 8, and then the unreacted monomer was removed by heating under reduced pressure. Then, it cooled to 30 degrees C or less, and obtained the water dispersion liquid containing a desired particulate-form binder.
Next, 100 parts of artificial graphite (volume average particle diameter D50: 15.6 μm) as a negative electrode active material and a 2% aqueous solution of carboxymethylcellulose sodium salt (manufactured by Nippon Paper Industries Co., Ltd., “MAC350HC”) as a thickener After substantially adjusting 1 part and ion-exchanged water to adjust the solid content concentration to 68%, the mixture was mixed at 25 ° C. for 60 minutes. Subsequently, it adjusted with ion-exchange water so that solid content concentration might be 62%, and also mixed for 15 minutes at 25 degreeC. Thereafter, 1.5 parts of an aqueous dispersion containing the above-mentioned particulate binder is added to the obtained mixed liquid, and ion-exchanged water corresponding to the solid content, and the final solid content concentration is adjusted to 52%. And mixed for another 10 minutes. This was defoamed under reduced pressure to obtain a negative electrode slurry composition having good fluidity.
Then, the negative electrode slurry composition obtained as described above was applied on a copper foil having a thickness of 20 μm, which is a current collector, with a comma coater so that the film thickness after drying was about 150 μm. , Dried. This drying was performed by conveying the copper foil in an oven at 60 ° C. at a speed of 0.5 m / min for 2 minutes. Thereafter, heat treatment was performed at 120 ° C. for 2 minutes to obtain a negative electrode raw material before pressing. The negative electrode raw material before pressing was rolled with a roll press to obtain a negative electrode after pressing with a negative electrode mixture layer thickness of 80 μm.

<Preparation of positive electrode>
100 parts of LiCoO ₂ (volume average particle diameter D50: 12 μm) as a positive electrode active material, ₂ parts of acetylene black (“HS-100” manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive material, particles for a positive electrode mixture layer Polyvinylidene fluoride (Kureha Co., Ltd., # 7208) as a binder was mixed with 2 parts corresponding to the solid content and N-methylpyrrolidone to make the total solid content concentration 70%. These were mixed by a planetary mixer to prepare a positive electrode slurry composition.
The positive electrode slurry composition obtained as described above was applied onto a 20 μm-thick aluminum foil as a current collector with a comma coater so that the film thickness after drying was about 150 μm and dried. I let you. This drying was performed by transporting the aluminum foil in an oven at 60 ° C. at a speed of 0.5 m / min for 2 minutes. Thereafter, heat treatment was performed at 120 ° C. for 2 minutes to obtain a positive electrode raw material. The positive electrode raw material before pressing was rolled with a roll press to obtain a positive electrode after pressing with a positive electrode mixture layer thickness of 80 μm.

<Manufacture of lithium ion secondary batteries>
Cut the positive electrode obtained above into 49 cm × 5 cm and place it so that the surface of the positive electrode mixture layer side is on the upper side, and then provide a separator having an adhesive layer on both sides cut out to 55 cm × 5.5 cm. Arranged. Further, the pressed negative electrode obtained above was cut into 50 cm × 5.2 cm, and this was placed on the separator so that the surface on the negative electrode mixture layer side faces the separator. This was wound with a winding machine to obtain a wound body. The wound body is pressed at 60 ° C. and 0.5 MPa to form a flat body, which is wrapped with an aluminum packaging exterior as a battery exterior, and an electrolytic solution (solvent: EC / DEC / VC (volume mixing ratio) = 68.5). /30/1.5, electrolyte: LiPF ₆ ) with a concentration of 1M was injected so that no air remained. Furthermore, in order to seal the opening of the aluminum packaging material exterior, heat sealing at 150 ° C. is performed to close the aluminum packaging material exterior, and a wound lithium ion secondary battery with a discharge capacity of 1000 mAh is manufactured as a non-aqueous secondary battery. did.
Using the obtained lithium ion secondary battery, the low-temperature output characteristics, the high-temperature cycle characteristics, the swell resistance, and the adhesion of the adhesive layer in the electrolytic solution (after cycle) were evaluated. The results are shown in Table 1 described later.

(Examples 2 to 4)
Except that the ratio of the monomer added for forming the shell part of the particulate binder A was changed as shown in Table 1 to be described later when preparing the aqueous dispersion containing the particulate binder A. In the same manner as in Example 1, a particulate binder A, a particulate binder B, an adhesive layer composition, a porous membrane layer slurry composition, an adhesive layer, a porous membrane layer, an adhesive layer, and a porous membrane layer are provided. A separator, a negative electrode, a positive electrode, and a lithium ion secondary battery were manufactured. Various evaluations were performed in the same manner as in Example 1. The results are shown in Table 1 described later.

(Example 5)
In preparation of the aqueous dispersion containing the particulate binder A, 0.4 part of sodium dodecylbenzenesulfonate is further added as an emulsifier in accordance with the addition of the monomer added for forming the shell part of the particulate binder A. Except for continuous addition, in the same manner as in Example 1, the particulate binder A, the particulate binder B, the adhesive layer composition, the porous membrane layer slurry composition, the adhesive layer, the porous membrane layer, and the adhesive A separator, a negative electrode, a positive electrode, and a lithium ion secondary battery provided with a layer and a porous membrane layer were produced. Various evaluations were performed in the same manner as in Example 1. The results are shown in Table 1 described later.

(Example 6)
When preparing an aqueous dispersion containing the particulate binder A, instead of 3-methacryloxypropyltrimethoxysilane as an alkoxysilyl group-containing monomer added for forming the shell part of the particulate binder A, Except for using vinyltrimethoxysilane (product name “A-171”, manufactured by Momentive Performance Materials, Inc.), the same as in Example 1, the particulate binder A, the particulate binder B, A composition for an adhesive layer, a slurry composition for a porous film layer, an adhesive layer, a porous film layer, a separator including the adhesive layer and the porous film layer, a negative electrode, a positive electrode, and a lithium ion secondary battery were produced. Various evaluations were performed in the same manner as in Example 1. The results are shown in Table 1 described later.

(Examples 7 and 8)
In the same manner as in Example 1, except that the pH of the adhesive layer composition was changed as shown in Table 1 described later using acetic acid and an aqueous sodium hydroxide solution, respectively, during the production of the adhesive layer composition. Adhesive A, particulate binder B, adhesive layer composition, porous membrane layer slurry composition, adhesive layer, porous membrane layer, separator provided with adhesive layer and porous membrane layer, negative electrode, positive electrode, and lithium ion secondary A battery was manufactured. Various evaluations were performed in the same manner as in Example 1. The results are shown in Table 1 described later.

(Examples 9 and 10)
Example except that boehmite (isoelectric point 7.8) and titanium oxide (isoelectric point 5.1) were used in place of alumina as the non-conductive particles at the time of producing the slurry composition for the porous membrane layer. 1, a particulate binder A, a particulate binder B, a composition for an adhesive layer, a slurry composition for a porous membrane layer, a separator comprising an adhesive layer, a porous membrane layer, an adhesive layer and a porous membrane layer, A negative electrode, a positive electrode, and a lithium ion secondary battery were manufactured. Various evaluations were performed in the same manner as in Example 1. The results are shown in Table 1 described later.

(Example 11)
Except for using the particulate binder A (non-composite polymer) prepared as follows, the particulate binder B, the adhesive layer composition, and the slurry for the porous membrane layer were the same as in Example 1. A separator, a negative electrode, a positive electrode, and a lithium ion secondary battery including a composition, an adhesive layer, a porous film layer, an adhesive layer, and a porous film layer were produced. Various evaluations were performed in the same manner as in Example 1. The results are shown in Table 1 described later.
<Preparation of particulate binder A (non-composite polymer)>
In a 5 MPa pressure vessel with a stirrer, 90 parts of styrene as an aromatic vinyl monomer, 5 parts of methacrylic acid as an acid group-containing monomer, and 3-methacryloxypropyltrimethoxy as an alkoxysilyl group-containing monomer Add 5 parts of silane, 1 part of sodium dodecylbenzenesulfonate as an emulsifier, 150 parts of ion-exchanged water, and 0.5 part of potassium persulfate as a polymerization initiator, and after sufficient stirring, warm to 70 ° C. Then, polymerization was started. When the polymerization conversion rate of all the added monomers reached 96%, the reaction was stopped by cooling to obtain an aqueous dispersion containing particulate binder A (corresponding to polymer A).

(Comparative Examples 1 and 2)
Except that the ratio of the monomer added for forming the shell part of the particulate binder A was changed as shown in Table 1 to be described later when preparing the aqueous dispersion containing the particulate binder A. In the same manner as in Example 1, a particulate binder A, a particulate binder B, an adhesive layer composition, a porous membrane layer slurry composition, an adhesive layer, a porous membrane layer, an adhesive layer, and a porous membrane layer are provided. A separator, a negative electrode, a positive electrode, and a lithium ion secondary battery were manufactured. Various evaluations were performed in the same manner as in Example 1. The results are shown in Table 1 described later.

In Table 1 shown below,
“MMA” indicates methyl methacrylate;
“MAA” indicates methacrylic acid,
“EDMA” refers to ethylene glycol dimethacrylate,
“ST” indicates styrene,
“MPTS” refers to 3-methacryloxypropyltrimethoxysilane,
“VTMS” indicates vinyltrimethoxysilane;
“ACL” indicates an acrylic polymer.

From Examples 1 to 11 and Comparative Examples 1 and 2 in Table 1 above, Examples using a particulate binder A containing a polymer A containing an alkoxysilyl group-containing monomer unit at a predetermined content ratio 1 to 11, it can be seen that the adhesive layer exhibits good adhesiveness (after immersion and after cycling) in the electrolyte, and the secondary battery can exhibit excellent high-temperature cycle characteristics and low-temperature output characteristics. . Furthermore, Examples 1 to 11 show that the amount of moisture brought into the secondary battery is small, and in addition, the secondary battery is excellent in swell resistance.
Further, from Examples 1 to 4 in the above table, by changing the content ratio of the alkoxysilyl group-containing monomer unit in the polymer A contained in the particulate binder A, in the electrolyte solution of the adhesive layer It can be seen that the adhesive property (after immersion, after cycle), and the secondary battery's swelling resistance, high temperature cycle characteristics and low temperature output characteristics can be improved, and the amount of moisture brought into the secondary battery can be reduced.
From Examples 1 and 5 in the above table, it can be seen that the low-temperature output characteristics of the secondary battery can be improved by changing the coverage of the particulate binder A (core-shell structure).
In addition, by adjusting the pH of the composition for the adhesive layer from Examples 1, 7, and 8 in the above table, the adhesiveness of the adhesive layer in the electrolytic solution (after immersion and after cycling) and the secondary battery It can be seen that the high-temperature cycle characteristics of can be improved.
Furthermore, the adhesiveness (immersion) of the adhesive layer in the electrolyte solution can be changed by changing the type (isoelectric point) of the inorganic oxide particles as non-conductive particles from Examples 1, 9, and 10 in the above table. It can be seen that the swell resistance, high temperature cycle characteristics and low temperature output characteristics of the secondary battery can be improved.
Further, from Examples 1 and 11 in the above table, it can be seen that the low-temperature output characteristics of the secondary battery can be improved by forming the particulate binder A as a core-shell structure and forming the shell portion with the polymer A. .

ADVANTAGE OF THE INVENTION According to this invention, the nonaqueous secondary battery adhesion | attachment which can form the contact bonding layer for nonaqueous secondary batteries which is excellent in the adhesiveness in electrolyte solution, and can exhibit the electrical property excellent in the nonaqueous secondary battery A layer composition can be provided.
In addition, according to the present invention, the adhesive layer for a non-aqueous secondary battery that is excellent in adhesion in an electrolytic solution and can exhibit excellent electrical characteristics in the non-aqueous secondary battery, and the non-aqueous system A non-aqueous secondary battery member provided with a secondary battery adhesive layer can be provided.
Furthermore, according to the present invention, a nonaqueous secondary battery having excellent electrical characteristics can be provided.
And according to this invention, providing the manufacturing method of the contact bonding layer for non-aqueous secondary batteries which is excellent in the adhesiveness in electrolyte solution, and can exhibit the electrical property excellent in the non-aqueous secondary battery. it can.

100 Particulate binder A (core shell structure)
110 Core part 110S Outer surface of core part 120 Shell part

Claims (7)

A composition for a non-aqueous secondary battery adhesive layer containing a particulate binder A and water,
The particulate binder A contains a polymer A containing an alkoxysilyl group-containing monomer unit in an amount of 0.1% by mass or more and 20% by mass or less. The composition for a non-aqueous secondary battery adhesive layer object. The particulate binder A has a core-shell structure including a core portion and a shell portion that partially covers the outer surface of the core portion,
The core portion is made of a polymer having an electrolyte solution swelling degree of 5 times or more and 30 times or less,
The composition for a non-aqueous secondary battery adhesive layer according to claim 1, wherein the shell part is made of the polymer A, and the electrolyte solution swelling degree of the polymer A is more than 1 time and 4 times or less.   The composition for non-aqueous secondary battery adhesive layers according to claim 1 or 2, wherein the pH is 3 or more and 6 or less.   The adhesive layer for non-aqueous secondary batteries formed using the composition for non-aqueous secondary battery adhesive layers in any one of Claims 1-3.   The non-aqueous secondary battery member containing the functional layer containing inorganic oxide particle and the contact bonding layer for non-aqueous secondary batteries of Claim 4 arrange | positioned adjacent to the said functional layer.   A nonaqueous secondary battery comprising at least one of the nonaqueous secondary battery adhesive layer according to claim 4 and the nonaqueous secondary battery member according to claim 5. Supplying the composition for a non-aqueous secondary battery adhesive layer according to any one of claims 1 to 3 onto a functional layer containing inorganic oxide particles;
Drying the composition for non-aqueous secondary battery adhesive layer supplied on the functional layer. A method for producing an adhesive layer for non-aqueous secondary battery.

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