JP6536017B2 - Composition for non-aqueous secondary battery adhesive layer, adhesive layer for non-aqueous secondary battery, non-aqueous secondary battery member, non-aqueous secondary battery, and method for producing adhesive layer for non-aqueous secondary battery - Google Patents

Description

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

  Non-aqueous secondary batteries such as lithium ion secondary batteries are characterized by their small size, light weight, high energy density, and capable of repeated charge and discharge, 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 non-aqueous system is achieved by suppressing cell swelling and expansion of the distance between the plates accompanying repetition of charge and discharge. 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 substrate having an electrode mixture layer formed on a current collector An electrode obtained by providing an adhesive layer on an electrode base material having a porous film layer formed thereon for the purpose of improving heat resistance and strength on the electrode mixture layer or on the electrode mixture layer is used. Further, as a separator to be adhered to the electrode through the adhesive layer, for example, a separator obtained by providing the adhesive layer on the separator base material formed by forming the porous film layer on an organic separator made of polyolefin etc. It is used.
Then, the electrode mixture layer of the electrode base material is formed by, for example, applying a slurry composition for an electrode including an electrode active material and a binder for an electrode mixture layer having binding properties on a current collector, It is formed by drying the applied slurry composition for electrodes. The porous film layer disposed on the surface of the electrode or separator may be, for example, a slurry composition for a porous film layer including non-conductive particles, a binder for a porous film layer having binding properties, etc. It forms by making the slurry composition for porous film layers apply | coated and apply | coated on a compound material layer or an organic separator, and drying.

Unexamined-Japanese-Patent No. 2001-84985

  Here, in recent years, an adhesive layer formed by dissolving or dispersing an adhesive in a hydrophilic solvent such as water for the formation of an adhesive layer for bonding battery members (electrodes, separators) from the viewpoint of environmental load reduction, etc. It has been proposed to use a composition. Specifically, the adhesive layer composition is provided on the surface by supplying the composition for the adhesive layer containing a hydrophilic solvent to at least one surface of the electrode substrate and the separator substrate, and drying the supplied composition for the adhesive layer. It has been proposed to form a battery member having the same.

  However, the adhesive layer produced by the conventional method is not particularly adhesive in an electrolytic solution, and exhibits excellent electrical characteristics for a secondary battery in which the battery members are adhered to each other by the adhesive layer. I couldn't let it go. Therefore, there is a need for a new technology for improving the adhesion of the adhesive layer in the electrolyte and for enhancing the electrical characteristics of a secondary battery using the adhesive layer.

Therefore, the present invention provides non-aqueous secondary battery adhesion capable of forming an adhesive layer for non-aqueous secondary batteries which is excellent in adhesiveness in an electrolytic solution and can exhibit excellent electric characteristics in non-aqueous secondary batteries. It is intended to provide a composition for layers.
Further, the present invention is an adhesive layer for a non-aqueous secondary battery, which is excellent in adhesiveness in an electrolytic solution and can exhibit excellent electric characteristics in the non-aqueous secondary battery, and the non-aqueous secondary secondary An object of the present invention is to provide a non-aqueous secondary battery member provided with a battery adhesive layer.
Furthermore, an object of the present invention is to provide a non-aqueous secondary battery having excellent electrical characteristics.
And this invention aims at providing the manufacturing method of the adhesion layer for non-aqueous secondary batteries which can exhibit the electrical property which was excellent in the adhesiveness in electrolyte solution, and was excellent in non-aqueous secondary batteries. 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 inventors diligently studied for the purpose of solving the above-mentioned problems. And if this inventor uses the copolymer containing the alkoxy silyl group containing monomer unit in the ratio within the specific range as an adhesive agent component of the composition for adhesive layers, The inventors have found that an adhesive layer can be formed which is excellent in adhesion in an electrolytic solution and can exhibit excellent electric characteristics in a secondary battery, and the present invention has been completed.

  That is, the present invention aims to advantageously solve the above-mentioned problems, and the composition for a non-aqueous secondary battery adhesive layer of the present invention comprises a particulate binder A and water. It is a composition for next battery contact bonding layers, Comprising: The said particulate-form binder A is characterized by including the alkoxy silyl group containing monomer unit 0.1 to 20 mass%. Using a particulate binder A containing a 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 excellent in adhesion in an electrolytic solution An adhesive layer for a non-aqueous secondary battery can be produced, 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 according to the present invention has a core-shell structure in which the particulate binder A has a core portion and a shell portion partially covering the outer surface of the core portion. The core portion is made of a polymer having an electrolyte swelling degree of 5 to 30 times, the shell portion is made of the polymer A, and the electrolyte swelling degree of the polymer A is It is preferable to be more than 1 time and 4 times or less. Thus, the particulate binder A has a specific core-shell structure, the electrolyte swelling degree of the polymer constituting the core portion is 5 times to 30 times, and the polymer of which the shell portion is mentioned above When the electrolyte swelling degree of the polymer A is more than 1 time and 4 times or less, the electrical characteristics of the non-aqueous secondary battery such as low temperature output characteristics can be further improved.

  And as for the composition for non-aqueous secondary battery adhesive layers of this invention, it is preferable that pH is three or more and six or less. If the pH of the composition for a non-aqueous secondary battery adhesive layer is 3 or more and 6 or less, the reactivity of the alkoxysilyl group in the particulate binder A decreases and the stability increases in the composition for an adhesive layer. Therefore, as a result, the adhesiveness in the electrolyte solution of the obtained adhesive layer 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 a composition for any non-aqueous secondary battery adhesive layers mentioned above It is characterized in that it is formed using As described above, the adhesive layer formed using any one of the above-described adhesive layer compositions exhibits excellent adhesion in an electrolytic solution and exhibits excellent electrical characteristics in non-aqueous secondary batteries. Can.

  Another object of the present invention is 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 adhesive layer for the non-aqueous secondary battery described above. Thus, in the electrode or separator in which the above-mentioned adhesive layer is directly provided on the functional layer containing the inorganic oxide particles, the adhesive layer and the functional layer (porous film layer, electrode mixture layer) are good in the electrolytic solution 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 an adhesive layer for the above-mentioned 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 provided with the adhesive layer described above 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, The manufacturing method of the adhesive layer for non-aqueous secondary batteries of this invention is either of the non-aqueous secondary battery adhesive layers mentioned above And supplying the composition for use on the functional layer containing inorganic oxide particles, and drying the composition for the non-aqueous secondary battery adhesive layer supplied on the functional layer. Do. Thus, the adhesive layer produced on the functional layer containing the inorganic oxide particles adheres well to the functional layer in the electrolytic solution, and can exhibit excellent electrical characteristics in the non-aqueous secondary battery. it can.

According to the present invention, non-aqueous secondary battery adhesion capable of forming an adhesive layer for non-aqueous secondary battery which is excellent in adhesiveness in an electrolytic solution and can exhibit excellent electric characteristics to the non-aqueous secondary battery. A composition for layers can be provided.
Further, according to the present invention, an adhesive layer for a non-aqueous secondary battery capable of exhibiting excellent adhesion in an electrolytic solution and exhibiting excellent electric characteristics for the non-aqueous secondary battery, and the non-aqueous system The non-aqueous secondary battery member provided with the adhesive layer for secondary batteries can be provided.
Furthermore, according to the present invention, a non-aqueous secondary battery excellent in electrical characteristics can be provided.
And, according to the present invention, it is possible to provide a method for producing an adhesive layer for a non-aqueous secondary battery which is excellent in adhesiveness in an electrolytic solution and can exhibit excellent electric characteristics in the non-aqueous secondary battery. it can.

It is sectional drawing which shows typically the structure of an example of the particulate-form 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 this invention is used as a material at the time of preparing the adhesive layer for non-aqueous secondary batteries of this invention. Moreover, the adhesive layer for non-aqueous secondary batteries of this invention is prepared using the composition for non-aqueous secondary batteries adhesive layers of this invention, and comprises some non-aqueous secondary battery members, such as a separator and an electrode. Do. And the non-aqueous secondary battery member of this invention is equipped with the contact bonding layer of this invention. Further, in the non-aqueous secondary battery of the present invention, non-aqueous secondary battery members are bonded to each other through the adhesive layer for non-aqueous secondary battery 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 adhesion 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. It is a slurry composition which made water a dispersion medium.
And the adhesive layer formed using the composition for non-aqueous secondary battery adhesive layers of this invention is excellent in the adhesiveness in electrolyte solution, and exhibits the electrical property excellent in a secondary battery. Can.
The proportion of the particulate binder A contained in the composition for a non-aqueous secondary battery adhesive layer is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 20% by mass or more. It is usually 90% by mass or less.

<Particle-like binder A>
The particulate binder A is a component that functions as a binder that secures the adhesiveness of the resulting adhesive layer. Here, the particulate binder A is usually composed of a non-water-soluble polymer, is present in the form of particles in an aqueous medium, and is contained in the adhesive layer while maintaining its particle shape.
In the present invention, "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. .

  The particulate binder A is characterized by containing a polymer A containing 0.1% by mass or more and 20% by mass or less of an alkoxysilyl group-containing monomer unit. In the present specification, “containing a monomer unit” means that “a monomer derived structural unit is contained 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-mentioned content ratio exhibits excellent adhesiveness in the electrolytic solution, and The electrical characteristics of the non-aqueous secondary battery provided with the adhesive layer can be favorably improved.

The reason why the above-mentioned excellent effects can be obtained by using the above-mentioned 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 to a silanol group through hydrolysis. For example, when drying an adhesive layer composition on a substrate to form an adhesive layer, the silanol group is a functional component 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 hydroxyl groups formed by contact with water by dehydration condensation, etc. It is surmised that the adhesiveness between the functional layers disposed adjacent to the adhesive layer (that is, the adhesiveness between the adhesive layer and the base material) is improved, and the excellent adhesiveness is exhibited also in the electrolytic solution.
Further, as described above, for example, when the adhesive layer and the functional layer are dehydrated and condensed, the water present in particular in the inorganic oxide particles in the functional layer can be discharged together out of the system. It is presumed that the amount of water brought into the battery can be reduced, and the generation of gas caused by the decomposition of the electrolyte can be suppressed, and the swelling of the battery cell can be suppressed.
Then, it is presumed that it is possible to improve the electrical characteristics such as the high temperature cycle characteristics and the low temperature output characteristics by the contribution of the above-mentioned improvement of the adhesiveness and the reduction of the carried-in water amount.

[Structure of Particulate Binding Material A]
The structure of the particulate binder A is not particularly limited, and may be a non-composite polymer substantially composed of a single polymer component (polymer A), and at least one of the polymer A and the polymer A. It may be a composite polymer composed of a polymer other than the kind of 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, a portion constituting the circumferential surface of the particulate binder A). When the polymer A constitutes a part or all of the outer surface portion of the particulate binder A, the resulting adhesive layer can exhibit excellent adhesiveness in the electrolytic solution.

The composite polymer is obtained by polymerizing at least one monomer component according to a conventional method, and subsequently polymerizing at least one other monomer component according to the conventional method (two-stage polymerization method) or the like. It can be easily manufactured. And the particle | grains which consist of composite polymers turn into a heterophase structure in which a different polymer part exists in the inside of particle | grains.
Here, the heterophasic structure is a single particle formed by physical or chemical bonding of two or more different polymers, and formed from a single polymer such as a block polymer. It is not a particle consisting of a single phase structure. And as a specific example of the hetero-phase structure, a core-shell structure in which spherical particles are formed of polymers having different center and outer shell parts; side-by-side having a structure in which two or more polymers are juxtaposed Structure: Snow-Daluma structure in which a part of the polymer in the central part is exposed to the outer shell part in the core-shell structure; Another kind of polymer particle embedded and integrated on the surface of spherical polymer particle Idako structure; 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-complex 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, in addition to the alkoxysilyl group-containing monomer, an aromatic vinyl monomer, an acid group-containing monomer, a crosslinkable monomer, and the like.

-Alkoxysilyl group-containing monomer-
As the alkoxysilyl group-containing monomer, an alkoxysilyl group and a structure copolymerizable with other monomers (for example, excluding a polymerizable unsaturated bond such as a carbon-carbon double bond, and an alkoxysilyl group) It is not particularly limited as long as it is a monomer containing Here, the alkoxysilyl group may be any of a monoalkoxysilyl group, a dialkoxysilyl group, and a trialkoxysilyl group, but a trialkoxysilyl group is preferable.

As the alkoxysilyl group-containing monomer, from the viewpoint of reducing the amount of water carried into the secondary battery while further enhancing the adhesiveness of the adhesive layer, vinylsilane-based monomers and (meth) acrylsilane-based monomers Is preferably mentioned.
Examples of the vinylsilane-based monomer include vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (2-methoxyethoxy) silane and vinylmethyldimethoxysilane.
As a (meth) acryl silane type monomer, 3-methacryloxypropyl triethoxysilane, 3-methacryloxypropyl trimethoxysilane, etc. are mentioned.
Among these, 3-methacryloxypropyl triethoxysilane and vinyltriethoxysilane are more preferable.
In the present specification, “(meth) acrylic” means acrylic and / or methacrylic. Moreover, an alkoxy silyl group containing monomer may be used individually by 1 type, and may be used combining 2 or more types.

  The content ratio of the alkoxysilyl group-containing monomer unit in the polymer A is required to be 0.1% by mass or more and 20% by mass or less, preferably 0.5% by mass or more, and more preferably 1.5 The content is preferably at least 1.8 mass%, more preferably at most 15 mass%, more preferably at most 10 mass%, and still more preferably at most 8 mass%. If the proportion of the alkoxysilyl group-containing monomer unit is less than the lower limit value of the above range, the adhesiveness of the adhesive layer in the electrolytic solution can not be ensured, and the water content carried into the secondary battery also increases. In addition, the electrical characteristics of the secondary battery are degraded. In addition, if the ratio of the alkoxysilyl group-containing monomer unit exceeds the upper limit value of the above range, the silanol groups formed by the conversion of the alkoxysilyl group in the polymer A are dehydrated and condensed, so the substrate side The reactivity with the hydroxyl group of the compound decreases, and the adhesive layer can not be well adhered to the substrate in the electrolytic solution. In addition, the polymer A has excessive hydrophilicity, the amount of water carried into the secondary battery increases, and the low-temperature output characteristics of the secondary battery deteriorate.

  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 a single amount in which the alkoxysilyl group is converted to a silanol group Body units are also included in alkoxysilyl group-containing monomer units (monomer units derived from alkoxysilyl group-containing monomers).

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

  The proportion of the aromatic vinyl monomer unit in the polymer A is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 85% by mass or more, preferably 95% by mass or less, more preferably It is 93 mass% or less, more preferably 92 mass% or less. By setting the proportion of the aromatic vinyl monomer unit in the above range, the adhesion 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 in the suitable range which mentions 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.

And as a monomer which has a carboxylic acid group, monocarboxylic acid, dicarboxylic acid, etc. are mentioned, for example. As a monocarboxylic acid, acrylic acid, methacrylic acid, crotonic acid etc. are mentioned, for example. Examples of dicarboxylic acids include maleic acid, fumaric acid, itaconic acid and the like.
Further, as a monomer having a sulfonic acid group, for example, vinyl sulfonic acid, methyl vinyl sulfonic acid, (meth) allyl sulfonic acid, ethyl (meth) acrylic acid-2-sulfonic acid, 2-acrylamido-2-methyl Propanesulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid and the like can be mentioned. In the present specification, "(meth) allyl" means allyl and / or methallyl.
Furthermore, as a monomer having a phosphoric acid group, for example, phosphoric acid-2- (meth) acryloyloxyethyl, methyl-2- (meth) acryloyloxyethyl phosphate, ethyl phosphate- (meth) acryloyloxyethyl phosphate Etc. In the present specification, “(meth) acryloyl” means acryloyl and / or methacryloyl.
Moreover, as a monomer which has a hydroxyl group, acrylic acid 2-hydroxyethyl, acrylic acid 2-hydroxypropyl, methacrylic acid 2-hydroxyethyl, methacrylic acid 2-hydroxypropyl etc. are mentioned, for example. The monomer having a hydroxyl group does not include a monomer containing a silanol group.

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

  And, the proportion 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, 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 proportion of the acid group-containing monomer unit in 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 may contain a crosslinkable monomer unit. The crosslinkable monomer is a monomer which can form a crosslinked structure during or after polymerization by heating or irradiation of energy rays. By including the crosslinkable monomer unit, the degree of swelling of the polymer can be easily made 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. As such polyfunctional monomers, for example, divinyl compounds such as divinyl benzene; di (meth) acrylic acid esters such as diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, 1,3-butylene glycol diacrylate and the like Compounds; tri (meth) acrylic acid ester compounds such as trimethylolpropane trimethacrylate and trimethylolpropane triacrylate; and ethylenically unsaturated monomers containing an epoxy group such as allyl glycidyl ether and glycidyl methacrylate. 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 swelling of the electrolytic solution. Moreover, a crosslinking | crosslinked monomer may be used individually by 1 type, and may be used combining 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 further The content is preferably 0.5% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, and still more preferably 3% by 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 more, more preferably 60 ° C. or more, still more preferably 70 ° C. or more, particularly preferably 80 ° C. or more Preferably it is 200 degrees C or less, More preferably, it is 150 degrees C or less, More preferably, it is 120 degrees C or less, Especially preferably, it is 100 degrees C or less. By making the glass transition temperature of the particulate binder A at least the lower limit value of the above range, the high temperature cycle characteristics of the secondary battery can be improved. Further, by setting the glass transition temperature of the particulate binder A to the upper limit value of the above range or less, the adhesiveness of the adhesive layer in the electrolytic solution can be further enhanced.
In addition, the "glass transition temperature" of the particulate-form binder A (polymer A) can be measured using the method as described in the Example of this specification.

The electrolyte solution swelling degree of the particulate binder A (polymer A) as a non-composite polymer is preferably more than 1 time, more preferably 1.1 times or more, 1.2 times or more Is more preferably 4 times or less, more preferably 3.5 times or less, and still more preferably 3 times or less. By making the electrolyte solution swelling degree of the particulate binder A equal to or more than the lower limit value of the above range, the adhesiveness of the adhesive layer in the electrolyte solution can be enhanced, and the high temperature cycle characteristics of the secondary battery can be further improved. . Also, by setting the degree of electrolyte swelling of the particulate binder A below the upper limit of the above range, the adhesion of the adhesive layer in the electrolyte is enhanced, and the high temperature cycle characteristics of the secondary battery are further improved. be able to.
The “electrolyte solution swelling degree” of the particulate binder A (polymer A) is a measurement of the electrolyte swelling degree described later in the section of “particulate binder A as a composite polymer having a core-shell structure”. It can measure according to a 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 making the volume average particle diameter D50 of the particulate binder A equal to or more than the lower limit value of the above range, it is possible to suppress an increase in internal resistance of the adhesive layer and to 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 value of the above range, the adhesiveness of the particulate binder A in the electrolytic solution is enhanced and the high temperature cycle characteristics are further improved. be able to.
The volume average particle diameter D50 of the particulate binder A is the particle diameter distribution of the water dispersion liquid adjusted to a solid content concentration of 15 mass%, which is wet measured 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%.

-Preparation method of particulate binder A (non-composite polymer)-
Examples of the method of 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, polymerization can be carried out in water, and the aqueous dispersion containing the particulate binder A comprising the polymer A can be suitably used as it is as a material for the composition for the adhesive layer, so the emulsion polymerization method and suspension weight can be used. Legal is preferred. Although the particulate binder A as a non-complex polymer is generally formed by the polymer A which substantially constitutes it, it may be accompanied by an optional component such as an additive used in 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 above-described polymer A. If the shell part is composed of polymer A, a particulate binder is obtained by applying a polymer component other than polymer A to the core part while securing the adhesiveness of the adhesive layer in the electrolytic solution. This is because the performance of A can be enhanced. 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 partially covering the outer surface of the core portion, and the core portion has an electrolyte swelling degree Is 5 times or more and 30 times or less, and the shell portion is more preferably 1 or more and 4 times or less the electrolyte solution swelling degree of the polymer A. .

  Thus, the adhesiveness of the adhesive layer in the electrolyte is further enhanced by keeping the electrolyte swelling degree of the polymer having a specific core-shell structure and constituting the core portion and the shell portion within a specific range. At the same time, the electrical characteristics such as the low temperature output characteristics of the non-aqueous secondary battery provided with the adhesive layer can be further improved.

In addition, the above-mentioned excellent effects are obtained by using the particulate binder A having a specific core-shell structure and having the electrolyte solution swelling degree of the polymer constituting the core portion and the shell portion within a specific range. The reason for obtaining is not clear but is presumed to be as follows.
First, due to the contribution of the alkoxysilyl group of the polymer A constituting the above-mentioned shell part, the adhesive layer adheres particularly well to the substrate (electrode substrate, separator substrate) before being immersed in the electrolytic solution. However, swelling of the polymer A in the shell portion in the electrolyte solution makes the adhesion stronger, while the adhesive layer adheres on the surface opposite to the substrate, and the adhesive layer The adhesion between them can also be improved. Specifically, when the polymer A constituting the shell swells in the electrolyte, for example, the functional group (except for the alkoxysilyl group and the silanol group) possessed by the polymer A in the swollen shell is activated. Battery members (for example, a separator and an electrode) through the adhesive layer containing the particulate binder A due to factors such as chemical or electrical interaction with the surface of the base material or the battery member. It is presumed that it is possible to bond strongly in the inside.
Further, as described above, since the separator and the electrode can be strongly bonded in the electrolytic solution, in the secondary battery provided with the adhesive layer, the battery members bonded via the adhesive layer (for example, It is hard to produce an air gap between electrodes). Therefore, in the secondary battery using the adhesive layer containing the particulate binder A, the distance between the positive electrode and the negative electrode in the secondary battery is unlikely to be large, and the internal resistance of the secondary battery can be reduced, and The reaction site of the chemical reaction is unlikely to be nonuniform. Furthermore, in the secondary battery, even if charge and discharge are repeated, a gap is hardly formed between the separator and the electrode, and the battery capacity is unlikely to be reduced. It is surmised that this can realize excellent swelling resistance and high-temperature cycle characteristics.
Further, the polymer constituting the core portion of the particulate binder A swells to a large extent with respect to the electrolytic solution. Then, in the state where the polymer is greatly swollen in the electrolytic solution, the gaps between the molecules of the polymer become large, and the ions easily pass between the molecules. In addition, the polymer of the core portion of the particulate binder A is not completely covered by the shell portion. Therefore, since the ions can easily pass through the core in the electrolytic solution, the particulate binder A can exhibit high ion diffusion. Therefore, it is presumed that if the above-mentioned particulate binder A is used, it is possible to suppress an increase in resistance due to the adhesive layer and to suppress a decrease in electrical characteristics such as low temperature output characteristics.

  The particulate binder A having the specific core-shell structure described above has a core-shell structure including a core portion and a shell portion covering the outer surface of the core portion, and the shell portion is a core portion. Partially cover the outer surface of the That is, although the shell portion of the particulate binder A covers the outer surface of the core portion, it does not cover the entire outer surface of the core portion. Even if it looks like the outer surface of the core portion is completely covered by the shell portion in appearance, if the hole communicating the inside and outside of the shell portion is formed, the shell portion is outside the core portion It is a shell part which partially covers the surface. Therefore, for example, in the case of including 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, the shell of the particulate binder A The part will partially cover the core part.

  The cross-sectional structure of an example of the particulate binder A having the specific core-shell structure described above is shown in FIG. Particulate binder A 100 has a core-shell structure including core portion 110 and shell portion 120. Here, the core portion 110 is a portion located inside the shell portion 120 in the particulate binder A100. In addition, the shell portion 120 is a portion covering the outer surface 110S of the core portion 110, and is generally the outermost portion 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 portion is covered by the shell portion is preferably 10% or more, more preferably 30% or more, and still more preferably 50% or more. Preferably it is 95% or less, More preferably, it is 90% or less, More preferably, it is 80% or less. By setting the coverage to the lower limit value of the above range or more, the adhesion of the adhesive layer in the electrolyte can be further improved. Further, by setting the coverage to the upper limit value or less of the above range, the ion diffusion of the adhesive layer can be enhanced, and the low temperature output characteristics of the secondary battery can be further improved.

The average rate at which the outer surface of the core portion is covered by the shell portion 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, after the particulate binder A is sufficiently dispersed in a room temperature curable epoxy resin, it is embedded to prepare a block piece containing the particulate binder A. Next, the block piece is cut into a thin plate of 80 nm to 200 nm thick with a microtome equipped with a diamond blade to prepare a measurement sample. Thereafter, the sample for measurement is subjected to a staining process using, for example, ruthenium tetraoxide or osmium tetraoxide, as necessary.
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 such that the cross section of one particulate binder A is within the field of view, and specifically about 10,000 times.
In the cross-sectional structure of the particulate binder A taken, measure the circumferential length D1 corresponding to the outer surface of the core portion and the length D2 of the portion where the outer surface of the core portion abuts the shell portion . Then, using the measured length D1 and length D2, the ratio Rc of the outer surface of the core portion of the particulate binder A to be covered by the shell portion is calculated by the following equation (1).
Cover ratio Rc (%) = (D2 / D1) × 100 (1)
The covering ratio Rc is measured for 20 or more particulate binders A, and the average value thereof is calculated to be the average ratio (covering ratio) in 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 a commercially available image analysis software, for example, “AnalySIS Pro” (manufactured by Olympus Corporation) can be used.

  The particulate binder A may have any component other than the above-mentioned core portion and shell portion as long as the intended effect is not significantly impaired. Specifically, for example, the particulate binder A may have a portion formed of a polymer different from the core portion inside the core portion. As a specific example, seed particles used when producing the particulate binder A by a seed polymerization method may remain inside the core portion. However, from the viewpoint of exerting the intended effect remarkably, the particulate binder A preferably has only the core portion and the shell portion.

  The volume average particle diameter D50 of the particulate binder A as a composite polymer having a core-shell structure is measured similarly to the volume average particle diameter D50 of the particulate binder A as the non-composite polymer. The preferred range thereof and the reason why it is preferred to fall within the range are also the same as those of the particulate binder A as the non-composite polymer.

-Core section-
The core portion 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 solution swelling degree of the polymer of the core portion is preferably 5 times or more, more preferably 6 times or more, still more preferably 7 times or more, and 30 times It is preferably not more than 25 times, more preferably 20 times or less. By setting the electrolyte solution swelling degree of the polymer of the core portion to the lower limit value or more of the above range, the ion diffusion of the adhesive layer can be enhanced, and the low temperature output characteristics of the secondary battery can be further improved. Moreover, the adhesiveness in the electrolyte solution of an contact bonding layer can be improved by making the electrolyte solution swelling degree of the polymer of a core part below the upper limit of the said range, and high temperature cycle characteristics can further be improved.

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

And the electrolyte solution swelling degree of the polymer of a core part can be measured as follows specifically ,.
First, the polymer of the core portion of the particulate binder A is prepared. For example, a polymer obtained by performing the same steps as those for forming the core portion in the preparation of the particulate binder A is prepared. Then, a film is produced by the prepared polymer. For example, if the polymer is solid, the polymer is dried under the conditions of a temperature of 25 ° C. for 48 hours, and then the polymer is formed into a film to prepare a film having a thickness of 0.5 mm. Also, for example, when the polymer is a solution or dispersion such as latex, the solution or dispersion is put into a petri dish made of polytetrafluoroethylene and dried under conditions of a temperature of 60 ° C. for 72 hours, and then it is necessary. Heat press according to to make a 0.5 mm thick film.
Next, the film produced as described above is cut into 1 cm square to obtain a test piece. The weight of this test piece is measured and taken as W0. Further, this test piece is immersed in the above-mentioned electrolytic solution at a temperature of 60 ° C. for 72 hours, and the test piece is taken out of the electrolytic solution. The electrolytic solution on the surface of the test piece taken out is wiped off, and the weight W1 of the test piece after immersion is measured.
Then, using these weights W0 and W1, the swelling degree S (fold) is calculated by S = W1 / W0.

  In addition, as a method of adjusting the electrolyte solution swelling degree of the polymer of the core part, for example, in consideration of the SP value of the electrolyte, the kind and amount of the monomer for producing the polymer of the core part Proper selection may be mentioned. In general, when the SP value of a polymer is close to that of the electrolyte, the polymer tends to swell in the electrolyte. On the other hand, when the SP value of the polymer is separated from the SP value of the electrolyte, the polymer tends to be difficult to swell in the electrolyte.

Here, the SP value means the solubility parameter.
And SP value can be calculated using the method introduced by Hansen Solubility Parameters A User's Handbook, 2nd Ed (CRCPress).
Further, the SP value of an organic compound can also 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)) capable of calculating the SP value from the SMILE equation. In this simulation software, Hansen SOLUBILITY PARAMETERS A User's Handbook Second Edition, Charles M. Based on the theory described in Hansen, SP values are determined.

The monomer used to prepare the polymer of the core portion is not particularly limited, and for example, one having the electrolyte swelling degree of the polymer in the above range may be appropriately selected and used. As such monomers, for example, vinyl chloride monomers such as vinyl chloride and vinylidene chloride; vinyl acetate monomers such as vinyl acetate; styrene, α-methylstyrene, styrene sulfonic acid, butoxystyrene, Aromatic vinyl monomers such as vinylnaphthalene; vinylamine monomers such as vinylamine; vinylamide monomers such as N-vinylformamide, N-vinylacetamide; monomers having a carboxylic acid group, sulfonic acid groups Acid group-containing monomers such as monomers having a phosphate group, monomers having a phosphate group, monomers having a hydroxyl group; (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 and 2-ethylhexyl acrylate; (Meth) acrylamide monomers such as luamide and methacrylamide; (meth) acrylonitrile monomers such as acrylonitrile and methacrylonitrile; such as 2- (perfluorohexyl) ethyl methacrylate and 2- (perfluorobutyl) ethyl acrylate Fluorine-containing (meth) acrylate monomers; maleimide; maleimide derivatives such as phenyl maleimide; diene-based monomers such as 1,3-butadiene and isoprene; and the like. Moreover, these may be used individually by 1 type and may be used combining 2 or more types.
In the present specification, “(meth) acrylo” means acrylo and / or methacrylo.

  Among the above monomers, (meth) acrylic acid ester monomers and (meth) acrylonitrile monomers are preferably used as monomers to be used for preparation of the polymer of the core part, (meth) It is more preferable to use an acrylic ester 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 preferable to include a monomer unit derived from methyl methacrylate. Thereby, control of the degree of swelling of the polymer is facilitated, and the ion diffusion of the adhesive layer using the particulate binder A can be further enhanced.

  The proportion of (meth) acrylic acid ester monomer units in the polymer of the core portion 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 the lower limit value or more of the above range, the ion diffusion of the adhesive layer can be enhanced, and the low temperature output characteristics of the secondary battery can be further improved. In addition, by setting the ratio of (meth) acrylic acid ester monomer units to the upper limit value or less of the above range, the adhesiveness of the adhesive layer in the electrolytic solution is enhanced, and the high temperature cycle characteristics of the secondary battery are further improved. be able to.

  Also, the polymer of the core part 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. Specifically, examples of the acid group-containing monomer include the same monomers as those described above in the section "Particulate binder A as a non-complex polymer".

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

  Further, the proportion of the acid group-containing monomer unit in the polymer of the core portion is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 3% by mass or more, preferably 20% by mass The following content is more preferably 10% by mass or less, further preferably 7% by mass or less. By setting the ratio of the acid group-containing monomer unit in the above range, the dispersibility of the polymer of the core portion is enhanced at the time of preparation of the particulate binder A, and the core portion is made to the outer surface of the core portion polymer The shell portion that partially covers the outer surface of the shell can be easily formed.

  Moreover, it is preferable that the polymer of a core part contains a crosslinkable monomer unit in addition to the said monomer unit. Specifically, as the crosslinkable monomer capable of forming the crosslinkable monomer unit, the same amount as the monomer described above in the section "Particulate binder A as a non-composite polymer" 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 swelling of the polymer of the core part. Moreover, these may be used individually by 1 type and may be used combining 2 or more types.

  Here, in general, when the proportion of the crosslinkable monomer unit in the polymer increases, the degree of swelling of the polymer in the electrolyte tends to decrease. Therefore, the proportion of the crosslinkable monomer units is preferably determined in consideration of the type and amount of monomers used. The specific proportion of the crosslinkable monomer unit in the polymer of the core portion is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and still more 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 making the ratio of the crosslinkable monomer unit equal to or more than the lower limit value of the above range, the adhesiveness of the adhesive layer in the electrolyte solution can be enhanced, and the high temperature cycle characteristics can be further improved. Further, by making the proportion of the crosslinkable monomer unit not more than the upper limit value of the above range, the polymerization stability at the time of preparation of the particulate binder A is secured, and the particulate binder A obtained is suitable. It can be in the form of particles.

Further, the glass transition temperature of the polymer of the core portion is preferably 0 ° C. or more, more preferably 50 ° C. or more, still more preferably 80 ° C. or more, preferably 150 ° C. or less, more preferably 140 ° C. or less, more preferably Is 130 ° C. or less. The low temperature output characteristics of the secondary battery can be further improved by setting the glass transition temperature of the polymer of the core portion to the lower limit value of the above range or more. Moreover, the adhesiveness of the particulate-form binder A can be further improved by making the glass transition temperature of the polymer of a core part below the upper limit of the said range.
In addition, the "glass transition temperature" of the polymer of a core part can be measured using the method as described in the Example of this specification.

  Furthermore, the diameter of the core portion is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more, particularly preferably 80% or more relative to 100% of the volume average particle diameter of the particulate binder A It is the above, Preferably it is 99% or less, More preferably, it is 98.5% or less, More preferably, it is 98% or less. By setting the diameter of the core portion to the lower limit value or more of the above range, the ion diffusion of the adhesive layer can be enhanced. On the other hand, by making the diameter of the core portion not more than the upper limit value of the above range, the adhesiveness of the adhesive layer can be enhanced.

  Here, the diameter of the core portion can be measured as the volume average particle diameter D50 of the particulate polymer obtained before forming the shell portion, which is obtained in the production process of the particulate binder A. The particulate polymer before forming such a shell part corresponds to the particulate polymer constituting the core part. 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 portion of the particulate binder A is preferably made of a polymer having a predetermined electrolyte swelling degree smaller than the electrolyte swelling degree of the core portion. Moreover, it is preferable that the shell part of the particulate-form binder A consists of the polymer A mentioned above.
Here, the electrolyte solution swelling degree of the polymer of the shell portion is preferably more than 1 time, more preferably 1.1 times or more, still more preferably 1.2 times or more, and 4 times It is preferable that it is the following, It is more preferable that it is 3.5 times or less, It is more preferable that it is 3 times or less. The high temperature cycle characteristics of the secondary battery can be further improved by setting the electrolyte solution swelling degree of the polymer of the shell portion to the lower limit value of the above range or more. In addition, by making the electrolyte solution swelling degree of the polymer of the shell part not more than the upper limit value of the above range, the adhesiveness in the electrolyte solution of the adhesive layer can be enhanced and the high temperature cycle characteristics of the secondary battery can be further improved. it can.

  Here, as the electrolyte used to measure the electrolyte swelling degree of the polymer of the shell part, the same one as the electrolyte used to measure the electrolyte swelling degree of the polymer of the core part is used.

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

  Here, as a method of adjusting the degree of electrolyte swelling of the polymer of the shell portion, for example, the type and amount of monomers for producing the polymer of the shell portion in consideration of the SP value of the electrolytic solution It is possible to select an appropriate one.

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

  Among these monomers, as a monomer used for preparation of the polymer of a shell part, the monomer mentioned above as a monomer which can be used in order to manufacture the polymer A is preferable. And, as a suitable range of the content ratio of the shell part of the monomer unit derived from those monomers in the polymer, and the reason that it is preferable to fall within the range, Is the same as that described above in the section of "Particulate binder A".

In addition, the preferable range of the glass transition temperature of the polymer of the shell portion and the reason for being preferable to fall within the range are those described above in the "Particulate binder A as non-composite polymer" The “glass transition temperature” of the polymer of the shell portion can be measured using the method described in the examples of the present specification.

  Furthermore, the shell portion preferably has an average thickness falling 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 portion to the volume average particle diameter D50 of the particulate binder A is preferably 1.5% or more, more preferably 3% or more, still more preferably 5% or more Preferably it is 40% or less, More preferably, it is 30% or less, More preferably, it is 20% or less. By making the average thickness of the shell part equal to or more than the lower limit value of the above range, the adhesion of the adhesive layer in the electrolyte solution can be enhanced, and the high temperature cycle characteristics can be further improved. 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 portion in the cross-sectional structure of the particulate binder A is measured using a TEM, and the average maximum thickness of the shell portions of 20 or more particulate binders A selected arbitrarily The value is taken as the average thickness of the shell portion. However, the shell portion is constituted by particles of the polymer, and the particles constituting the shell portion do not overlap each other in the radial direction of the particulate binder A, and the particles of the polymer are a single layer When the shell portion is formed, the number average particle diameter of particles constituting the shell portion is taken as the average thickness of the shell portion.

  Further, the form of the shell portion is not particularly limited, but the shell portion is preferably constituted by particles of a polymer (specifically, polymer A). When the shell portion is constituted by particles of a polymer, a plurality of particles constituting the shell portion may be overlapped 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 do not overlap with each other, and the particles of the polymer constitute the shell in a single layer.

  Furthermore, when the shell part is constituted by particles of a polymer, 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 The thickness is preferably 150 nm or less, more preferably 100 nm or less. By keeping the number average particle diameter in the above range, the balance between the ion diffusivity and the adhesiveness can be improved.

  The number average particle diameter of the particles constituting the shell portion can be 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 in the cross-sectional structure of the particulate binder A is measured, and the particles of the arbitrarily selected 20 or more particles of the particulate binder A are The average value of the longest diameter can be taken as the number average particle diameter of the particles constituting the shell portion.

-Method of preparing particulate binder A (core-shell structure)-
The particulate binder A as a composite polymer having the above-described core-shell structure is, for example, used temporally with the monomer of the polymer of the core portion and the monomer of the polymer of the shell portion. It can be prepared by stepwise polymerization with changing the ratio of those monomers. Specifically, the particulate binder A is prepared by a continuous multistage emulsion polymerization method and a multistage suspension polymerization method in which the polymer of the first stage is sequentially coated with the polymer of the first stage. be able to.

  Therefore, an example in the case of obtaining the particulate binder A having the above-mentioned core-shell structure by the multistage emulsion polymerization method will be shown below.

  In polymerization, as an emulsifier, for example, an anionic surfactant such as sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, a nonionic surfactant such as polyoxyethylene nonyl phenyl ether, sorbitan monolaurate, or the like according to a conventional method Cationic surfactants such as octadecylamine acetate can be used. Also, as a polymerization initiator, for example, peroxides such as t-butylperoxy-2-ethylhexanoate, potassium persulfate, cumene peroxide, etc., 2,2′-azobis (2-methyl-N- (2) Azo compounds such as -hydroxyethyl) -propionamide), 2,2'-azobis (2-amidinopropane) hydrochloride and the like can be used.

  Then, as a polymerization procedure, first, a monomer forming the core portion and an emulsifying agent are mixed, and emulsion polymerization is performed at one time to obtain a particulate polymer constituting the core portion. Furthermore, the particulate binder A having a core-shell structure described above can be obtained by polymerizing the monomer that forms the shell in the presence of the particulate polymer constituting the core.

  At this time, from the viewpoint of partially covering the outer surface of the core portion with the shell portion, the monomer forming the polymer of the shell portion is supplied to the polymerization system in a plurality of times or continuously. Is preferred. The polymer forming the shell is formed in the form of particles by dividing the monomer forming the polymer of the shell into a polymerization system or continuously, and the particles are bonded to the core Thus, a shell portion that partially covers the core portion can be formed.

  Here, in the case where the monomer that forms the polymer of the shell part is divided and supplied in a plurality of times, the particle diameter of the particles and the shell part of the particles that constitute the shell part according to the ratio of dividing the monomer. It is possible to control the average thickness. In addition, when continuously supplying the monomer that forms the polymer of the shell portion, the particle diameter of the particles constituting the shell portion and the shell portion are adjusted by adjusting the supply amount of the monomer per unit time. It is possible to control the average thickness of

  In addition, when a monomer having a low affinity to the polymerization solvent is used as a monomer for forming the polymer of the shell portion, the shell portion which partially covers the core portion tends to be easily formed. Accordingly, when the polymerization solvent is water, the monomer forming the polymer of the shell part preferably contains a hydrophobic monomer, and particularly preferably contains an aromatic vinyl monomer.

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

  The volume average particle diameter D50 of the particulate polymer constituting the core portion, the volume average particle diameter D50 of the particulate binder A after forming the shell portion, and the number average of the particles constituting the shell portion The particle size can be in the desired range by, for example, adjusting the amount of emulsifier, the amount of monomer, and the like.

  Furthermore, the average ratio in which the outer surface of the core is covered by the shell corresponds to the volume average particle diameter D50 of the particulate polymer constituting the core, for example, the amount of emulsifier and the weight of the shell A desired range can be obtained by adjusting the amount of monomers that form a unit.

<Binding material other than particulate binding material A>
Here, from the viewpoint of improving the flexibility of the adhesive layer and the adhesiveness in the electrolyte solution in a well-balanced manner, the composition for a 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").

And as particulate-form binder B which can be used together with the above-mentioned particulate-form binder A, it is non-water-soluble, and the well-known particulate-form binder dispersible in water, for example, thermoplastic elastomer, is mentioned. 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 conjugated diene monomer units, and specific examples of the conjugated diene polymer include aromatic vinyl monomers such as styrene-butadiene copolymer (SBR). Included are polymers comprising monomeric units and aliphatic conjugated diene monomeric units. Moreover, an acryl-type polymer points out the polymer containing a (meth) acrylic acid ester monomer unit.
These particulate binders B may be used alone or in combination of two or more.

  In the acrylic polymer as the particulate binder B, the content ratio of (meth) acrylic acid ester monomer units is preferably 20% by mass or more, more preferably 30% by mass or more, and more preferably 40% by mass It is the above, Preferably it is 90 mass% or less, More preferably, it is 85 mass% or less, More preferably, it is 80 mass% or less. The monomer unit other than the (meth) acrylic acid ester monomer unit contained in the acrylic polymer as the particulate binder B is not particularly limited, but a hydroxyl group-containing monomer in the particulate binder B may be used. The content ratio of the monomer unit is preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 1% by mass or less. By setting the content 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. It adheres well to

The glass transition temperature of the polymer constituting the particulate binder B is preferably -100 ° C or more, more preferably -50 ° C or more, preferably 25 ° C or less, more preferably 10 ° C or less, and further Preferably it is 0 degrees C or less. By setting the glass transition temperature of the particulate binder B to the lower limit value of the above range or more, the flexibility of the adhesive layer can be enhanced. Moreover, the adhesiveness in the electrolyte solution of a contact bonding layer can be further improved by below a glass transition temperature being the upper limit of the said range.
In addition, the "glass transition temperature" of the particulate-form binder B can be measured using the method as described in the Example of this 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 setting the volume average particle diameter D50 of the particulate binder B to the lower limit value of the above range or more, the dispersibility of the particulate binder B can be enhanced. Moreover, the adhesiveness in the electrolyte solution of the contact bonding layer can be further improved by making volume average particle diameter D50 below 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 blending amount of the particulate binder B in the composition for adhesive layer is preferably 1 part by mass or more, and 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 making content of the particulate-form binder B more than the lower limit of the said range, the adhesiveness in the electrolyte solution of an adhesive layer and the softness | flexibility of an adhesive layer can be ensured with sufficient balance. In addition, by setting the content of the particulate binder B to the upper limit value or less of the above range, it is possible to suppress the decrease in ion diffusion of the adhesive layer 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 secured without inhibiting the adhesive property improving function of the particulate binder A.

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

<Other ingredients>
The composition for non-aqueous secondary battery adhesive layer may contain any other component in addition to the components described above. These other components include, for example, known additives such as wetting agents, thickeners, electrolyte additives and the like. Also, these other components may be used alone or in combination of two or more.

<Method of preparing composition for non-aqueous secondary battery adhesive layer>
The method for preparing the composition for adhesive layer is not particularly limited, but usually, the particulate binder A, water as a dispersion medium, and the particulate binder B used as needed and other components To prepare a composition for an adhesive layer. The mixing method is not particularly limited, but 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 ball mills, sand mills, pigment dispersers, grinders, ultrasonic dispersers, homogenizers, planetary mixers and the like. Further, from the viewpoint of being able to add a high dispersion share, a high dispersion apparatus such as a bead mill, a roll mill, a film mix and the like can also be mentioned.

The pH of the composition for an adhesive layer to be obtained 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. Or less, more preferably 5 or less. If the pH of the composition for 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 (preservability) of the composition for adhesive layer is increased. It 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.
The pH of the adhesive layer composition can be adjusted by 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 a suitable substrate using the composition for non-aqueous secondary battery adhesive layers described above. The adhesive layer exhibits excellent adhesion in an electrolytic solution and can exhibit excellent electrical characteristics in a secondary battery. The adhesive layer may be provided on one side of the substrate or may be provided on both sides of the substrate.
The proportion of the particulate binder A contained in the adhesive layer for a non-aqueous secondary battery is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, particularly preferably 90%. It is mass% or more, and usually 100 mass% or less.

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

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.
It does not specifically limit as an electrode base material (a positive electrode base material and a negative electrode base material) which forms an adhesion layer, The electrode base material in which the electrode compound material layer was formed on the collector is mentioned. Here, components of the current collector, electrode mixture layer (for example, electrode active material (positive electrode active material, negative electrode active material) and binder for electrode mixture layer (positive electrode mixture layer binder, negative electrode combination) A binder for a material layer) and the like, and a method for forming an electrode mixture layer on a current collector may be known ones, and for example, one described in JP-A-2013-145763 is used. be able to.

Further, it is preferable that the separator base and the electrode base further include a porous film layer for the purpose of improving heat resistance and strength. The porous membrane layer is not particularly limited, and the non-conductive particles, the binder for the porous membrane layer, and the slurry composition for porous membrane layer obtained by dissolving or dispersing the thickener in a solvent such as water are dried. And those 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 JP-A-2013-145763 and for the porous membrane layer. As the binder, from the viewpoint of the flexibility and adhesiveness of the porous membrane layer, for example, the above-mentioned particulate binder B is preferably mentioned. Moreover, as a thickener, a known thickener can be used.
In addition, the method of drying the slurry composition for porous film layers, and providing a porous film layer in the surface of a separator base material or an electrode base material is not specifically limited, either, It is possible to employ | adopt a known method.

Here, the content of the binder for a 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 parts by mass or less, more preferably 5 parts by mass or less. If the content of the binder for the porous membrane layer is at least the lower limit value of the above range, the adhesiveness between the adhesive layer and the porous membrane layer (that is, the base material including the porous membrane layer) in the electrolytic solution is This can be further improved, and if it is below the upper limit value of the above range, the low temperature output characteristics of the secondary battery can be further improved. 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, and preferably 3 parts by mass, per 100 parts by mass of the nonconductive particles. The amount is preferably 2 parts by mass or less. If the content of the thickener is at least the lower limit of the above range, the adhesion between the adhesive layer and the porous membrane layer (that is, the base material including the porous membrane layer) in the electrolytic solution is further improved. If it is below the upper limit value of the said range, the carried-over water amount to a secondary battery can be reduced.
Here, the nonconductive particles in the porous membrane layer, the binder for the porous membrane layer, and the thickener are contained in the slurry composition for the porous membrane layer, and the presence thereof in the porous membrane layer The ratio is usually the same as the abundance ratio in the porous membrane layer slurry composition.
The proportion of the nonconductive particles in the porous membrane layer is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more.

  Here, as a base material (electrode base material, separator base material) which forms an adhesion layer, a base material which equips the surface with a functional layer containing inorganic oxide particles is preferred. 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 inorganic oxide particles used as the nonconductive particles of the porous film 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, etc. may be mentioned.
As an inorganic oxide particle used as an electrode active material of an electrode mixture layer, lithium cobaltate, lithium manganate, etc. are mentioned, for example.
The composition for an adhesive layer is supplied on the functional layer of a substrate having a functional layer containing such inorganic oxide particles on the surface, and the composition is dried to form an adhesive layer, thereby bonding by heating during drying. The particulate binder A of the layer composition and the inorganic oxide particles in the functional layer dehydrate and condense well, and the adhesion between the adhesive layer and the functional layer (that is, the 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 at least the lower limit value of the above range, dehydration condensation between the particulate binder A and the inorganic oxide particles becomes easy, and the adhesive layer and the functional layer It can be adhered well. In addition, when the pH of the isoelectric point of the inorganic oxide particles is not more than the upper limit value of the above range, the amount of water brought into the secondary battery can be reduced.
Here, the isoelectric point (pH) of the inorganic oxide particles can be measured by the method defined in JIS R1638.

  Furthermore, it is preferable that the isoelectric point (pH) of inorganic oxide particle is larger than pH of the composition for contact bonding layers. When the composition for adhesive layer is applied on the functional layer containing the inorganic oxide particles such that the isoelectric point of the inorganic oxide particles is higher than the pH of the composition for adhesive layer, the vicinity of the interface with the functional layer The pH of the composition for adhesive layer in the above increases, and the dehydration condensation between the particulate binder A and the inorganic oxide particles is promoted. And, from the viewpoint of enhancing the adhesiveness with the functional layer of the adhesive layer, the value obtained by subtracting the pH of the composition for adhesive layer from the isoelectric point (pH) of the inorganic oxide particles is preferably 1 or more, 2 It is more preferable that it is the above, and it is more preferable that it is three or more.

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

(Method of producing adhesive layer for non-aqueous secondary battery)
The method for producing an adhesive layer for a non-aqueous secondary battery of the present invention comprises the steps of: supplying a composition for a non-aqueous secondary battery adhesive layer onto a functional layer containing inorganic oxide particles (supplying step); And d) drying the composition for a non-aqueous secondary battery adhesive layer supplied thereto.

In the supply step, the method for supplying the adhesive layer composition onto the functional layer on the substrate surface is not particularly limited, and the adhesive layer composition may be applied onto the functional layer, or a group having a functional layer The material may be immersed in the adhesive layer composition. Among these, the former application method is preferable because it is easy to control the thickness of the adhesive layer.
And the method of apply | coating the composition for adhesive layers on a functional layer does not have a restriction | limiting in particular, For example, the spray coating method, the doctor blade method, the reverse roll method, the direct roll method, the gravure method, the extrusion method, the brushing method And the like. Among them, the gravure method and the spray coating method are preferable from the viewpoint of forming a thin adhesive layer.

  The method for drying the composition for the adhesive layer on the functional layer in the drying step is not particularly limited, and any known method can be used, for example, drying with warm air, hot air, low humidity air, vacuum drying, infrared rays, The drying method by irradiation of an electron beam etc. is mentioned. Although the drying conditions are not particularly limited, the drying temperature is preferably 30 to 80 ° C., and the drying time is preferably 30 seconds to 10 minutes.

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

(Non-aqueous secondary battery member)
The non-aqueous secondary battery member of the present invention comprises a functional layer containing inorganic oxide particles, and an adhesive layer for non-aqueous secondary battery disposed adjacent to the above-mentioned functional layer, specifically, The ones of
(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 the adhesive layer is disposed adjacent to the porous membrane layer containing inorganic oxide particles (non-conductive particles);
(3) An electrode in which the adhesive layer is disposed adjacent to an electrode mixture layer containing inorganic oxide particles (electrode active material);
Such a non-aqueous secondary battery member is provided with the non-aqueous secondary battery adhesive layer of the present invention, so that it is particularly excellent in the adhesiveness between the adhesive layer and the functional layer, and excellent in the secondary battery. Characteristics can be exhibited. And the non-aqueous secondary battery member of the present invention can be manufactured by providing an adhesive layer on a base material which has a functional layer, for example using the manufacturing method of the adhesive layer for non-aqueous secondary batteries mentioned above. it can.

(Non-aqueous secondary battery)
The non-aqueous secondary battery of the present invention comprises the adhesive layer for non-aqueous secondary batteries of the present invention described above 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 electrolytic solution, and the above-described non-aqueous secondary battery adhesive layer of the present invention is a battery member, positive electrode, negative electrode And at least one of the separators.
Since the non-aqueous secondary battery of the present invention includes the adhesive layer for non-aqueous 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, an electrode having an adhesive layer provided on an electrode substrate can be used as a positive electrode and a negative electrode having an adhesive layer, and a separator having an adhesive layer can be formed on a separator substrate. 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.
The positive electrode, the negative electrode, and the separator that do not have an adhesive layer are not particularly limited, and a separator made of the electrode made of the electrode base described above and the separator base made of the above can be used.

<Electrolyte solution>
As the electrolytic solution, an organic electrolytic solution in which a supporting electrolyte is dissolved in an organic solvent is usually used. As a supporting electrolyte, for example, a lithium salt is used in a lithium ion secondary battery. Examples of lithium salts include LiPF ₆ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , 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 them, 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. The electrolyte may be used alone or in combination of two or more. Usually, the lithium ion conductivity tends to be higher as the supporting electrolyte having a higher degree of dissociation is used, so the lithium ion conductivity can be adjusted by the type of the supporting electrolyte.

The organic solvent used for 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), 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; and the like are suitably used. Also, a mixture of these solvents may be used. Among them, carbonates are preferable because they have a high dielectric constant and a wide stable potential region. In general, the lower the viscosity of the solvent used, the higher the lithium ion conductivity tends to be. Therefore, the lithium ion conductivity can be controlled by the type of the solvent.
The concentration of the electrolyte in the electrolyte can be adjusted as appropriate. In addition, known additives may be added to the electrolytic solution.

<Method of manufacturing non-aqueous secondary battery>
In a non-aqueous secondary battery, for example, a positive electrode and a negative electrode are stacked via a separator, and this is wound or folded as needed into a battery container, and an electrolytic solution is injected into the battery container and sealed. Can be manufactured. Note that at least one member of the positive electrode, the negative electrode, and the separator is a member with an adhesive layer. Here, an expanded metal, a fuse, an overcurrent preventing element such as a PTC element, a lead plate, or the like may be inserted into the battery container as necessary to prevent a pressure increase inside the battery and overcharge and discharge. The shape of the battery may be, for example, a coin, a button, a sheet, a cylinder, a square, or a flat.

EXAMPLES Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. In the following description, “%” and “parts” representing amounts are based on mass unless otherwise specified.
Further, in a polymer produced by copolymerizing a plurality of types of monomers, the proportion of a structural unit formed by polymerizing a certain monomer in the polymer is usually, unless otherwise specified, It corresponds to the ratio (feed ratio) of a given monomer to the total monomers used for polymer polymerization.
In Examples and Comparative Examples, the electrolyte solution swelling degree of the polymer constituting the particulate binder A, the average ratio (coverage) in which the outer surface of the core part of the particulate binder A is covered by the shell part, the particles Thickness (core-shell ratio) of the shell portion of the binder A, volume average particle diameter D50 of each particle, glass transition temperature of each polymer, total water content of the adhesive layer and the porous film layer, electrolysis of the adhesive layer Adhesion in liquid (after immersion, after cycling), swelling resistance of secondary battery, high temperature cycle characteristics and low temperature output characteristics were measured and evaluated by the following methods.

<Electrolyte Swelling Degree of Polymer Constituting Particulate Binding Material A>
A polymer serving as a measurement sample under the same polymerization conditions as 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 (polymer in core portion and polymer in shell portion) were prepared. In addition, an aqueous dispersion of particulate binder A (non-composite polymer) was prepared.
Next, the aqueous dispersion described above is placed in a polytetrafluoroethylene petri dish, dried at a temperature of 60 ° C. for 72 hours, taken out of the petri dish, and heat pressed at 100 ° C. and 20 kg / cm ² for 5 minutes, A film of 0.5 mm in thickness was produced. Then, the obtained film was cut into 1 cm square to obtain a test piece. The weight of this test piece was measured, and it was set to W0. Moreover, the said test piece was immersed in electrolyte solution at the temperature of 60 degreeC for 72 hours. Thereafter, the test piece was taken out of 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. And swelling degree S (double) was calculated by S = W1 / W0 using these weight W0 and W1.
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 As} a supporting electrolyte, a solution obtained by dissolving LiPF ₆ at a concentration of 1 mol / L was used.
<Average ratio (coverage) in which the outer surface of the core portion of the particulate binder A is covered by the shell portion>
The particulate binder A (core-shell structure) is sufficiently dispersed in a visible light curable resin ("D-800" manufactured by Nippon Denshi Co., Ltd.) and then embedded to contain the particulate binder A. A block piece was made. Next, the block pieces were cut into thin pieces of 100 nm thick with a microtome equipped with a diamond blade to prepare a measurement sample. Thereafter, ruthenium tetraoxide was used to stain the measurement sample.
Next, the stained measurement sample was set on 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 was included in the field of view. Then, in the sectional structure of the particulate binder A taken, the circumferential length D1 of the core portion and the length D2 of the portion where the outer surface of the core portion abuts the shell portion are measured, and the following formula According to (1), the ratio Rc in which the outer surface of the core portion of the particulate binder A is covered by the shell portion was calculated.
Cover 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) that the outer surface of the core part is covered by the shell part did.
<Average Thickness of Shell Portion of Particulate Binding Material A (Core-Shell Ratio)>
The average thickness of the shell portion of the particulate binder A (core-shell structure) was measured by the following procedure.
When the shell portion was constituted by particles of a polymer, the cross-sectional structure of the particulate binder A was observed by a transmission electron microscope in the same manner as in the method of measuring the coverage. And the longest diameter of the particle | grains of the polymer which comprises a shell part was measured from the cross-section of the observed particulate-form binder A. FIG. The longest diameter of the particles of the polymer constituting the shell portion was measured for 20 particulate binders A optionally selected, and the average value of the longest diameter was taken as the average thickness of the shell portion.
When the shell portion had a shape other than particles, the cross-sectional structure of the particulate binder A was observed by a transmission electron microscope in the same manner as in the method of measuring the coverage. Then, the maximum thickness of the shell portion was measured from the cross-sectional structure of the observed particulate binder A. The maximum thickness of the shell portion was measured for 20 particulate binders A which were arbitrarily selected, and the average value of the maximum thickness was taken as the average thickness of the shell portion.
And it is a ratio of the average thickness of the shell part to the volume average particle diameter D50 of the particulate binder A 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 the particle diameter of the aqueous dispersion adjusted to a solid content concentration of 15% by mass, which is measured by a laser diffraction particle diameter distribution measuring apparatus ("SALD-3100" manufactured by Shimadzu Corporation) In the distribution, the particle diameter is such that the cumulative volume calculated from the small diameter side is 50%.
<Glass transition temperature (Tg)>
In the measurement of the glass transition temperature of the polymer of the core part of the particulate binder A (core-shell structure) and the polymer of the shell part, the monomer composition used for the preparation of each polymer is used, Under the same polymerization conditions as the polymerization conditions for combination, an aqueous dispersion containing a polymer to be a 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, 10 mg of the above-mentioned measurement sample is weighed on an aluminum pan using a differential thermal analysis measurement apparatus (product name “EXSTAR DSC 6220” manufactured by SII Nano Technology Inc.), and using an empty aluminum pan as a reference, measurement temperature The DSC curve was measured in the range of -100 ° C to 500 ° C at a temperature rising rate of 10 ° C / min under normal temperature and normal humidity. In this heating process, the baseline just before the endothermic peak of the DSC curve where the differential signal (DDSC) becomes 0.05 mW / min / mg or more, and the tangent of the DSC curve at the inflection point first appearing after the endothermic peak The glass transition temperature was determined from the point of intersection with.
<Total moisture content of adhesive layer and porous membrane layer>
In the same manner as in each of the examples and the comparative examples, a laminate of the porous membrane layer and the organic separator was produced, and then the organic separator was removed from the porous membrane layer to obtain a porous membrane layer which was an independent membrane. Then, an adhesive layer was formed on the porous membrane layer in the same manner as in each of the examples and the comparative examples, and a laminate composed of the adhesive layer and the porous membrane layer was produced. A laminate of the adhesive layer and the porous membrane layer was cut out into a size of 10 cm wide × 10 cm long, and used as a test piece. The test piece is left to stand at a temperature of 25 ° C. and a humidity of 50% for 24 hours, and then, using a coulometric titration type moisture meter, the Karl Fischer method (JIS K-0068 (2001) moisture vaporization method, vaporization temperature of 150 ° C.) The water content W was measured. The smaller this value is, the smaller the amount of water carried into the secondary battery is.
A: Water content W is 500 ppm or less B: Water content W is more than 500 ppm and 600 ppm or less C: Water content W is more than 600 ppm and 700 ppm or less D: Water content W is more than 700 ppm <Adhesiveness of adhesive layer in electrolyte (after immersion )>
In the same manner as in each of the examples and the comparative examples, a laminate of the porous membrane layer and the organic separator was produced, and then the organic separator was removed from the porous membrane layer to obtain a porous membrane layer which was an independent membrane. Then, an adhesive layer was formed on the porous membrane layer in the same manner as in each of the examples and the comparative examples, and a laminate composed of the adhesive layer and the porous membrane layer was produced. A laminate of the adhesive layer and the porous membrane layer was cut out into a size of 10 cm wide × 10 cm long, and used as a test piece. C. for 72 hours at 60.degree. C. for 72 hours in 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 / The substrate was immersed in cm ³ ) ^1/2 ) as a supporting electrolyte in LiPF ₆ dissolved at a concentration of 1 mol / L), the electrolyte was wiped off, and then a cellophane tape was attached to the surface of the adhesive layer. Under the present circumstances, as a cellophane tape, what was prescribed | regulated to JISZ1522 was used. Also, cellophane tape was fixed on a horizontal test bench. Thereafter, the stress was measured when one end of the porous membrane layer was pulled vertically at a tension rate of 50 mm / min and peeled off. This measurement was performed three times, the average value of stress was determined, and the average value was defined as the peel strength P1. The larger the measured peel strength P1, the better the adhesion layer retains excellent adhesion in the electrolyte.
A: Peel strength P1 is at least 20 N / m B: Peel strength P1 is at least 15 N / m and less than 20 N / m C: Peel strength P1 is less than 15 N / m <Bulge resistance of secondary battery>
After allowing the produced lithium ion secondary battery with a discharge capacity of 1000 mAh to stand in an environment of 25 ° C. for 24 hours, charging at 4.4 V, 0.1 C, 3 V, 0 in an environment of 25 ° C. The charge / discharge operation was performed by the 1 C discharge. Thereafter, the wound lithium ion secondary battery was immersed in liquid paraffin, and its volume V0 was measured. After measurement of volume V0, remove from liquid paraffin, repeat charge / discharge operation under environment of 60 ° C., immerse the wound lithium ion secondary battery after 1000 cycles in liquid paraffin, and set its volume V1 It was measured. Then, the volume change rate of cells ΔV (%) = {(V1−V0) / V0} × 100 before and after the cycle was calculated and evaluated based on the following criteria. It shows that the smaller the value of the volume change rate ΔV, the better the swelling 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 produced wound-type lithium ion secondary battery having a discharge capacity of 1000 mAh was allowed to stand in an environment of 25 ° C. for 24 hours. Next, under the environment of 25 ° C., charge / discharge operation was performed at a charge of 4.4 V, 0.1 C, a discharge of 2.75 V, 0.1 C, and an initial capacity C0 was measured. Thereafter, the same charge and discharge operation was further repeated under the environment of 60 ° C., and the capacity C1 after 1000 cycles was measured. Then, the capacity retention ratio ΔC (%) = C1 / C0 × 100 before and after the cycle was calculated and evaluated based on the following criteria. The larger the value of the capacity retention rate ΔC, the better the high-temperature cycle characteristics.
A: Capacity retention rate ΔC is 85% or more B: Capacity retention rate ΔC is 80% or more and less than 85% C: Capacity retention rate ΔC is less than 80% <Adhesivity of adhesive layer in electrolyte (after cycle)>
After the evaluation of the high temperature cycle characteristics, the cell was disassembled, and the laminate including 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. Under the present circumstances, as a cellophane tape, what was prescribed | regulated to JISZ1522 was used. Also, cellophane tape was fixed on a horizontal test bench. Thereafter, the stress was measured when one end of the negative electrode was pulled vertically at a tension rate of 50 mm / min and peeled off. This measurement was performed three times, the average value of stress was determined, and the average value was defined as the peel strength P2. The larger the measured peel strength P2, the more the adhesive layer after the cycle maintains excellent adhesion in the electrolyte.
A: Peel strength P2 is 5 N / m or more B: Peel strength P2 is 3 N / m or more and 5 N / m or less C: Peel strength P2 is less than 3 N / m <Low-temperature output characteristics of secondary battery>
The produced wound-type lithium ion secondary battery having a discharge capacity of 1000 mAh was allowed to stand in an environment of 25 ° C. for 24 hours. Thereafter, charge operation at 4.4 V, 0.1 C for 5 hours was performed under an environment of 25 ° C., and the voltage V0 at that time was measured. Thereafter, discharge operation was performed at a discharge rate of 1 C under an environment of −10 ° C., and voltage V1 was measured 15 seconds after the start of discharge. 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 less than 500mV B: Voltage change ΔV is more than 500mV and less than 700mV C: Voltage change ΔV is more than 700mV and less than 900mV D: Voltage change ΔV is more than 900mV

Example 1
Preparation of Particulate Binding Material A (Core-Shell Structure)
In a 5 MPa pressure resistant container with a stirrer, 75 parts of methyl methacrylate as a (meth) acrylic acid ester monomer and 4 parts of methacrylic acid as an acid group-containing monomer for forming the core portion of the particulate binder A Add 1 part of ethylene glycol dimethacrylate as a crosslinkable monomer, 1 part of sodium dodecylbenzene sulfonate as an emulsifier, 150 parts of ion exchanged water, and 0.5 parts of potassium persulfate as a polymerization initiator. The mixture was heated to 60 ° C. to initiate polymerization. Subsequently, when the polymerization conversion ratio reaches 96%, 18 parts of styrene as an aromatic vinyl monomer and an acid group are formed for forming the shell part (corresponding to the polymer A) of the particulate binder A. 1 part of methacrylic acid as a contained monomer and 1 part of 3-methacryloxypropyltrimethoxysilane (manufactured by Momentive Performance Materials, product name “A-174”) as an alkoxysilyl group-containing monomer The mixture was added continuously and warmed to 70 ° C. to continue the polymerization. When the polymerization conversion ratio of all the added monomers became 96%, the reaction was cooled to stop the reaction, and an aqueous dispersion containing the particulate binder A was obtained.
Then, the coverage, the core-shell ratio, and the volume average particle diameter D50 of the obtained particulate binder A 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 below.
<Preparation of Particulate Binding Material B>
In a reactor equipped with a stirrer, 70 parts of ion-exchanged water, 0.15 parts of sodium lauryl sulfate (manufactured by Kao Chemical Co., Ltd., product name "Emar 2F") as an emulsifier, and 0.5 parts of ammonium persulfate are respectively supplied The gas phase was replaced with nitrogen gas and the temperature was raised to 60.degree.
On the other hand, in another container, 50 parts of ion exchanged water, 0.5 parts of sodium dodecylbenzene sulfonate as a dispersant, 45 parts of 2-ethylhexyl acrylate, 50 parts of styrene, 3 parts of itaconic acid, N-methylol acrylamide 1 Parts and 1 part of allyl glycidyl ether were mixed to obtain a monomer mixture. The monomer mixture was continuously added to the reactor over 4 hours to carry out polymerization. The reaction was carried out at 60 ° C. during the addition. After completion of the addition, the reaction was further completed by stirring at 70 ° C. for 3 hours to complete the reaction, and an aqueous dispersion containing a particulate binder B (acrylic polymer) was prepared.
The volume average particle diameter D50 of the obtained particulate binder B was 0.15 μm, and the glass transition temperature was -15 ° C.
<Production of composition for adhesive layer>
Aqueous dispersion containing particulate binder A (100 parts in terms of solid content), aqueous dispersion containing particulate binder B equivalent to 8 parts in solid content, polyethylene glycol surfactant (Sannopco, Inc. 1 part of product name "SN 366" (product name) was further added and 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 this adhesive layer composition was measured. The results are shown in Table 1 below.
In addition, when the supernatant liquid obtained by centrifuging the composition for adhesive layer was analyzed by gas chromatography, the alcohol (silanol group) derived from the hydrolysis of 3-methacryloxypropyltrimethoxysilane was detected. It was confirmed that at least a part of the alkoxysilyl group contained in the binder A was hydrolyzed.

<Production of Slurry Composition for Porous Membrane Layer>
100 parts of alumina (Nippon Light Metals Co., Ltd. “LS-256”) having an isoelectric point of 8.9 as non-conductive particles, an acrylamide polymer (Arakawa Chemical Co., Ltd.) having a carboxylic acid group introduced as a thickener An aqueous dispersion containing Polystron (registered trademark) 117 ′ ′, which corresponds to a solid content: 1.0 part, and an aqueous dispersion liquid of the above-mentioned particulate binder B as a solid component equivalent as a binder for a porous membrane layer Then, 0.2 parts of polyethylene glycol type surfactant ("San Nopco SN Wet 366" manufactured by San Nopco Co., Ltd.) was mixed to obtain a slurry composition for a porous membrane layer.
<Formation of Porous Membrane Layer and Adhesive Layer, and Separator Comprising the Same>
The slurry composition for a porous membrane layer 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 applied to both sides of the organic separator to obtain a separator substrate having a porous membrane layer with a thickness of 2 μm on one side.
Furthermore, on the porous membrane layer of this separator base material, the composition for adhesive layers was apply | coated, 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 provided with an adhesive layer of 0.5 μm on one side.

<Preparation of Negative Electrode>
In a 5 MPa pressure resistant container with stirrer, 33 parts of 1,3-butadiene, 3.5 parts of itaconic acid, 63.5 parts of styrene, 0.4 parts of sodium dodecylbenzene sulfonate as an emulsifier, 150 parts of ion exchanged water and a polymerization initiator After 0.5 parts of potassium persulfate was added and sufficiently stirred, the mixture was heated to 50 ° C. to initiate polymerization. When the polymerization conversion 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 solution of sodium hydroxide was added to the mixture containing the above particulate binder to adjust to pH 8, and unreacted monomers were removed by heating under reduced pressure and distillation. Thereafter, it was cooled to 30 ° C. or less to obtain an aqueous dispersion containing the desired particulate 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 carboxymethyl cellulose sodium salt (Nippon Paper Industries Co., Ltd., “MAC 350 HC”) as a thickener The mixture was adjusted so that the solid content concentration would be 68% by mixing 1 part and ion exchange water correspondingly, and then mixed at 25 ° C. for 60 minutes. Subsequently, it adjusted with ion-exchange water so that solid content concentration might be 62%, and also it mixed at 25 degreeC for 15 minutes. After that, 1.5 parts of the aqueous dispersion containing the above-mentioned particulate binder in solid content equivalent and ion-exchanged water are added to the obtained mixed liquid so that the final solid concentration becomes 52%. And mixed for an additional 10 minutes. The resultant was defoamed under reduced pressure to obtain a slurry composition for the negative electrode having good fluidity.
Then, the negative electrode slurry composition obtained as described above is applied by a comma coater on a 20 μm thick copper foil as a current collector so that the film thickness after drying becomes about 150 μm. , Dried. This drying was performed by conveying the copper foil at a speed of 0.5 m / min for 2 minutes in an oven at 60 ° C. Then, it heat-processed at 120 degreeC for 2 minutes, and obtained the negative electrode original fabric before a press. The negative electrode material sheet before this pressing was rolled by a roll press to obtain a pressed negative electrode having a thickness of the negative electrode mixture layer 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, particulate for positive electrode mixture layer Polyvinylidene fluoride (Kureha Co., Ltd. # 7208) as a binder was mixed with 2 parts by solid equivalent, and N-methylpyrrolidone to make the total solid concentration 70%. These were mixed by a planetary mixer to prepare a slurry composition for a positive electrode.
The slurry composition for a positive electrode obtained as described above is coated with a comma coater on a 20 μm thick aluminum foil as a current collector so that the film thickness after drying becomes about 150 μm, and dried. I did. This drying was performed by conveying the aluminum foil at a speed of 0.5 m / min for 2 minutes in an oven at 60 ° C. Then, it heat-processed at 120 degreeC for 2 minutes, and obtained the positive electrode original fabric. The positive electrode material sheet before this pressing was rolled by a roll press to obtain a pressed positive electrode having a thickness of the positive electrode mixture layer of 80 μm.

<Manufacturing of lithium ion secondary battery>
The positive electrode after pressing obtained above is cut out to 49 cm × 5 cm, placed so that the surface on the positive electrode mixture layer side is on the upper side, and a separator provided with an adhesive layer on both sides cut out to 55 cm × 5.5 cm thereon Placed. Furthermore, the negative electrode after pressing obtained above was cut out to 50 cm × 5.2 cm, and this was placed on the separator so that the surface on the negative electrode mixture layer side faced the separator. This was wound by a winding machine to obtain a wound body. This wound body is pressed at 60 ° C. and 0.5 MPa, made flat, and wrapped with an aluminum packaging material as an exterior of a battery, and an electrolytic solution (solvent: EC / DEC / VC (volume mixing ratio) = 68.5 /30/1.5, electrolyte: 1 M concentration of LiPF ₆ ) was injected without leaving air. Furthermore, in order to seal the opening of the aluminum packaging material, heat sealing at 150 ° C. is performed and the aluminum packaging material is closed, and a wound lithium ion secondary battery having 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 swelling resistance, and the adhesion (after cycling) of the adhesive layer in the electrolytic solution were evaluated. The results are shown in Table 1 below.

(Examples 2 to 4)
When preparing the aqueous dispersion containing the particulate binder A, the ratio of the monomers added for forming the shell portion of the particulate binder A was changed as shown in Table 1 to be described later. In the same manner as in Example 1, a particulate binder A, a particulate binder B, a composition for an adhesive layer, a slurry composition for a porous membrane layer, an adhesive layer, a porous membrane, 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. Then, in the same manner as in Example 1, various evaluations were performed. The results are shown in Table 1 below.

(Example 5)
At the time of preparation of the aqueous dispersion containing the particulate binder A, 0.4 part of sodium dodecylbenzene sulfonate is further added as an emulsifier according to the addition of the monomer added for forming the shell part of the particulate binder A A particulate binder A, a particulate binder B, a composition for an adhesive layer, a slurry composition for a porous membrane layer, an adhesive layer, a porous membrane layer, and an adhesive, in the same manner as in Example 1, except that continuous addition is performed. A separator, a negative electrode, a positive electrode and a lithium ion secondary battery provided with a layer and a porous membrane layer were manufactured. Then, in the same manner as in Example 1, various evaluations were performed. The results are shown in Table 1 below.

(Example 6)
Instead of 3-methacryloxypropyltrimethoxysilane as the alkoxysilyl group-containing monomer added for forming the shell portion of the particulate binder A when preparing the aqueous dispersion containing the particulate binder A, A particulate binder A, a particulate binder B, and the like in the same manner as in Example 1 except that vinyltrimethoxysilane (manufactured by Momentive Performance Materials, product name “A-171”) was used. An adhesive layer composition, a porous membrane layer slurry composition, an adhesive layer, a porous membrane layer, a separator comprising the adhesive layer and the porous membrane layer, a negative electrode, a positive electrode and a lithium ion secondary battery were produced. Then, in the same manner as in Example 1, various evaluations were performed. The results are shown in Table 1 below.

(Examples 7 and 8)
A particulate binder was prepared in the same manner as in Example 1, except that acetic acid and an aqueous solution of sodium hydroxide were used respectively to change the pH of the composition for an adhesive layer as shown in Table 1 described later when producing the composition for an adhesive layer. Adhesive material A, particulate binder material B, composition for adhesive layer, slurry composition for porous film layer, adhesive layer, porous film layer, separator provided with adhesive layer and porous film layer, negative electrode, positive electrode and secondary lithium ion The battery was manufactured. Then, in the same manner as in Example 1, various evaluations were performed. The results are shown in Table 1 below.

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

(Example 11)
A particulate binder B, a composition for an adhesive layer, and a slurry for a porous membrane layer in the same manner as in Example 1 except that a particulate binder A (non-composite polymer) prepared as follows is used. A separator, a negative electrode, a positive electrode and a lithium ion secondary battery provided with a composition, an adhesive layer, a porous membrane layer, an adhesive layer and a porous membrane layer were manufactured. Then, in the same manner as in Example 1, various evaluations were performed. The results are shown in Table 1 below.
Preparation of Particulate Binding Material A (Non-Complexed Polymer)
In a 5 MPa pressure resistant container 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 5 parts of silane, 1 part of sodium dodecylbenzene sulfonate as an emulsifier, 150 parts of ion exchange water, and 0.5 parts of potassium persulfate as a polymerization initiator are added, and after sufficiently stirring, heated to 70 ° C. The polymerization was initiated. When the polymerization conversion ratio of all the added monomers reached 96%, the reaction was cooled to stop the reaction, and an aqueous dispersion containing particulate binder A (corresponding to polymer A) was obtained.

(Comparative Examples 1 and 2)
When preparing the aqueous dispersion containing the particulate binder A, the ratio of the monomers added for forming the shell portion of the particulate binder A was changed as shown in Table 1 to be described later. In the same manner as in Example 1, a particulate binder A, a particulate binder B, a composition for an adhesive layer, a slurry composition for a porous membrane layer, an adhesive layer, a porous membrane, 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. Then, in the same manner as in Example 1, various evaluations were performed. The results are shown in Table 1 below.

In Table 1 below,
"MMA" indicates methyl methacrylate,
"MAA" indicates methacrylic acid,
"EDMA" refers to ethylene glycol dimethacrylate,
"ST" indicates styrene,
"MPTS" represents 3-methacryloxypropyl trimethoxysilane,
"VTMS" indicates vinyltrimethoxysilane,
"ACL" shows an acrylic polymer.

From Examples 1 to 11 and Comparative Examples 1 and 2 in Table 1 above, an example using a particulate binder A containing a polymer A containing an alkoxysilyl group-containing monomer unit at a predetermined content ratio In 1 to 11, it can be seen that the adhesive layer exhibits good adhesiveness (after immersion, after cycling) in the electrolyte solution, and the secondary battery can exhibit excellent high temperature cycle characteristics and low temperature output characteristics. . Furthermore, it is understood that Examples 1 to 11 have a small amount of carried-in water to the secondary battery and, in addition, are excellent in the swelling resistance of the secondary battery.
In addition, according to Examples 1 to 4 of the above-mentioned table, the content of the alkoxysilyl group-containing monomer unit in the polymer A contained in the particulate binder A is changed in the electrolytic solution of the adhesive layer. It can be seen that the adhesion (after immersion, after cycling), and the swelling resistance of the secondary battery, the high temperature cycle characteristics and the low temperature output characteristics can be improved, and the water content carried into the secondary battery can be reduced.
And it turns out that the low temperature output characteristic of a secondary battery can be improved by changing the coverage of the particulate-form binder A (core-shell structure) from Example 1 and 5 of the above-mentioned table | surface.
In addition, according to Examples 1, 7 and 8 of the above-mentioned table, the adhesiveness of the adhesive layer in the electrolytic solution (after immersion, after cycle) and the secondary battery by adjusting the pH of the composition for the adhesive layer It can be seen that the high temperature cycle characteristics of can be improved.
Furthermore, by changing the type (isoelectric point) of the inorganic oxide particles as the nonconductive particles according to Examples 1, 9 and 10 in the above table, the adhesion (immersion in the electrolyte solution of the adhesive layer) It can be seen that the after-cycle, post-cycle), and expansion resistance, high temperature cycle characteristics and low temperature output characteristics of the secondary battery can be improved.
Further, it is understood from Examples 1 and 11 in the above-mentioned table that the low temperature output characteristics of the secondary battery can be improved by forming the particulate binder A into a core-shell structure and forming the shell part by the polymer A. .

According to the present invention, non-aqueous secondary battery adhesion capable of forming an adhesive layer for non-aqueous secondary battery which is excellent in adhesiveness in an electrolytic solution and can exhibit excellent electric characteristics to the non-aqueous secondary battery. A composition for layers can be provided.
Further, according to the present invention, an adhesive layer for a non-aqueous secondary battery capable of exhibiting excellent adhesion in an electrolytic solution and exhibiting excellent electric characteristics for the non-aqueous secondary battery, and the non-aqueous system The non-aqueous secondary battery member provided with the adhesive layer for secondary batteries can be provided.
Furthermore, according to the present invention, a non-aqueous secondary battery excellent in electrical characteristics can be provided.
And, according to the present invention, it is possible to provide a method for producing an adhesive layer for a non-aqueous secondary battery which is excellent in adhesiveness in an electrolytic solution and can exhibit excellent electric characteristics in the non-aqueous secondary battery. it can.

100 Particulate binder A (core-shell structure)
110 core part 110S core part outer surface 120 shell part

Claims (7)

A composition for a non-aqueous secondary battery adhesive layer comprising a particulate binder A and water,
The particulate binder A contains a polymer A containing 0.1% by mass or more and 20% by mass or less of an alkoxysilyl group-containing monomer unit ,
The polymer A further contains 1.0% by mass or more of a monomer unit having a carboxylic acid group, and contains an aromatic vinyl monomer unit, and
The composition for a non-aqueous secondary battery adhesive layer, wherein the glass transition temperature of the polymer A is 50 ° C. or more and 200 ° C. or less . The particulate binding material A has a core-shell structure including a core portion and a shell portion partially covering the outer surface of the core portion,
The core portion is made of a polymer having an electrolyte swelling degree of 5 to 30 times,
The composition for a non-aqueous secondary battery adhesive layer according to claim 1, wherein the shell portion 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 of Claim 1 or 2 whose pH is three or more and six or less.   The adhesive layer for non-aqueous secondary batteries formed using the composition for non-aqueous secondary batteries adhesive layers in any one of Claims 1-3.   A non-aqueous secondary battery member comprising a functional layer containing inorganic oxide particles, and the adhesive layer for a non-aqueous secondary battery according to claim 4 disposed adjacent to the functional layer.   A non-aqueous secondary battery comprising at least one of the non-aqueous secondary battery adhesive layer according to claim 4 and the non-aqueous 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;
And drying the composition for a non-aqueous secondary battery adhesive layer supplied onto the functional layer.

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