JP6365011B2 - Resin fine particles for electricity storage device underlayer, ink for forming underlayer, current collector with underlayer, electrode for electricity storage device, electricity storage device. - Google Patents

Description

The present invention relates to a resin particle for an electricity storage device underlayer, an ink for forming an underlayer, a current collector with an underlayer having an underlayer obtained by using the ink, and an electricity storage device having the current collector with the underlayer The present invention relates to an electrode and an electricity storage device.

In recent years, small portable electronic devices such as digital cameras and mobile phones have been widely used. These electronic devices have always been required to minimize the volume and reduce the weight, and the batteries to be mounted are also required to be small, light, and have a large capacity. Also, in large-sized secondary batteries for automobiles and the like, it is desired to realize a large-sized secondary battery instead of the conventional lead-acid battery, and there is a need for a longer life in various environments where the battery is used. It has been. In addition, capacitors such as electric double layer capacitors and lithium ion capacitors are also attracting attention as power storage devices with high output and high energy density.

In order to meet such demands, development of secondary batteries such as lithium ion secondary batteries and alkaline secondary batteries, and development of electricity storage devices such as capacitors, for example, ink for underlayer used for forming underlayer of electrode plate layer Interest in the development of

The base layer of the electricity storage device is composed of a conductive additive and a binder. Patent Document 1 discloses an undercoat layer in which a conductive composition containing conductive carbon powder and a water-soluble binder such as an acrylic acid polymer is coated on a current collector of an electrode. Patent Document 2 discloses an undercoat forming composition prepared by mixing carbon black powder and butyl rubber in toluene. However, these compositions require further improvement in adhesion to the current collector when used as a base layer, and further improve the water resistance necessary for coating the mixture ink on the upper layer. Therefore, further improvement has been desired for extending the life of the battery.

For these improvements, in Patent Document 3, the adhesion of the underlayer to the current collector is improved by adding a low molecular crosslinking agent having two or more crosslinking groups to the resin dispersion. It is disclosed that a highly conductive electrode is obtained. However, since the resin dispersion and the crosslinking component exist independently, there is a potential problem that either uneven distribution occurs depending on the drying conditions and sufficient adhesion and water resistance cannot be obtained. . In addition, the environment in which the battery is used varies, and in a battery that can withstand an environment such as a high temperature, it is necessary to further improve the adhesion of electrodes and charge / discharge cycle characteristics.

Japanese Patent Laid-Open No. 62-160656 Japanese Unexamined Patent Publication No. Sho 63-121265 Japanese Patent Laid-Open No. 7-201362

The present invention provides an underlayer having excellent adhesion to a current collector or an electrode plate layer and having excellent water resistance, and an electricity storage device underlayer capable of providing an electricity storage device having excellent charge / discharge cycle characteristics The purpose is to provide fine resin particles. Furthermore, a current collector with an underlayer for an electricity storage device having both excellent adhesion to the current collector and excellent water resistance, an electrode for an electricity storage device using the underlayer, and an electricity storage device using these electrodes The purpose is to provide.

That is, the present invention provides a monomer (c) having 0.1 to 20% by weight of one ethylenically unsaturated group and a monofunctional or polyfunctional blocked isocyanate group in one molecule. The monomer having an ethylenically unsaturated group (e) The monomer having an ethylenically unsaturated group containing 80 to 99.9% by weight is emulsified in water in the presence of a surfactant with a radical polymerization initiator. Resin fine particles for polymerized electricity storage device underlayer (A) (However, monomer (e) is a monomer having one ethylenically unsaturated group and a monofunctional or polyfunctional alkoxysilyl group in one molecule. Monomer (a), a monomer (b) having one ethylenically unsaturated group in one molecule and a monofunctional or polyfunctional isocyanate group, and one ethylenically unsaturated group in one molecule; With mono- or polyfunctional alkylolamide groups (D) is not included .
Further, the present invention relates to a monomer (a) having one ethylenically unsaturated group per molecule, a monofunctional or polyfunctional alkoxysilyl group, one ethylenically unsaturated group per molecule, 0.1 to 20% by weight of the monomer (c) having a monofunctional or polyfunctional blocked isocyanate group, and the monomer (e) having an ethylenically unsaturated group other than the monomer 80 to 99 Resin fine particles for an electricity storage device underlayer (A) obtained by emulsion polymerization of a monomer having an ethylenically unsaturated group containing .9 wt% in water in the presence of a surfactant with a radical polymerization initiator (however, , Monomer (e) is monomer (b) having one ethylenically unsaturated group and monofunctional or polyfunctional isocyanate group in one molecule, and one ethylenically unsaturated group in one molecule Groups and mono- or polyfunctional alkylolamides And the monomer (d) having a group is not included .

In the present invention, the monomer (e) having an ethylenically unsaturated group has a monomer (f) having one ethylenically unsaturated group and an alkyl group having 8 to 18 carbon atoms in one molecule. And / or a monomer (g) having one ethylenically unsaturated group and a cyclic structure in one molecule, and the monomer (f) and / or (g) is a total monomer. The resin fine particles (A) for an electricity storage device underlayer are characterized by being contained in 30 to 95% by weight in a total of 100%.

The present invention also provides an ink for forming an electricity storage device underlayer comprising the resin fine particles for an electricity storage device underlayer (A), a water-soluble resin (B), and a conductive carbon material (C). About.

The present invention also relates to the ink for forming an electricity storage device underlayer, wherein the water-soluble resin (B) has a hydroxyl value of 10 to 1275 mgKOH / g.

The present invention also relates to a current collector with a base layer for a power storage device, comprising a current collector and a base layer formed from the ink for forming a power storage device base layer.

The present invention also relates to an electrode for an electricity storage device comprising the current collector with an underlayer for the electricity storage device and an electrode plate layer.

The present invention also relates to an electricity storage device including a positive electrode, a negative electrode, and an electrolyte solution, wherein at least one of the positive electrode and the negative electrode is the electrode for the electricity storage device.

The resin fine particles for the electricity storage device underlayer of the present invention are excellent in adhesion to the current collector and water resistance. By using the resin fine particles, the underlayer excellent in water resistance and adhesion to the current collector. Thus, an electric storage device having excellent charge / discharge cycle characteristics can be provided.

The resin fine particles for an electricity storage device underlayer of the present invention are functional group-containing resin fine particles obtained by copolymerizing a monomer containing an ethylenically unsaturated monomer having a specific functional group. . When the functional group in the resin fine particles (A) has a cross-linked structure with a current collector having a hydroxyl group on the surface, water resistance can be improved. Furthermore, by adjusting the amount of the cross-linked structure and the functional group, it is possible to obtain resin fine particles for an electricity storage device underlayer excellent in flexibility and stability.

<Resin fine particles (A)>
The resin fine particles (A) used for the binder for the electricity storage device underlayer of the present invention are resin fine particles obtained by emulsion polymerization of an ethylenically unsaturated monomer in water in the presence of a surfactant with a radical polymerization initiator. is there. The resin fine particles (A) used in the present invention are a monomer (a) having one ethylenically unsaturated group and a monofunctional or polyfunctional alkoxysilyl group in one molecule, and one ethylenic in one molecule. Monomer (b) having an unsaturated group and a monofunctional or polyfunctional isocyanate group (b) Monomer having one ethylenically unsaturated group and a monofunctional or polyfunctional blocked isocyanate group in one molecule ( c) and at least one monomer selected from the group consisting of a monomer (d) having one ethylenically unsaturated group and a monofunctional or polyfunctional alkylolamide group in one molecule 0.1 A monomer having an ethylenically unsaturated group containing 80 to 99.9% by weight of the monomer (e) having an ethylenically unsaturated group other than the monomers (a) to (d) Radical weight in the presence of surfactants in water It is a resin fine particle formed by emulsion polymerization with a combined initiator. The monofunctional or polyfunctional as used herein indicates that it has at least one functional group.

<Regarding Monomers (a) to (d)>
By using the monomers contained in the monomers (a) to (d), functional groups capable of crosslinking with hydroxyl groups can be left in or on the surface of the resin fine particles (A). Physical properties such as water resistance of the underlayer can be improved. The monomers contained in the monomers (a) to (d) are likely to remain in the interior or surface of the particles even after particle synthesis, and even with a small amount of the current collector and the hydroxyl group-containing water-soluble resin (B). The cross-linking effect is large.

Examples of the monomer (a) having one ethylenically unsaturated group and a monofunctional or polyfunctional alkoxysilyl group in one molecule include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethyl. Ethoxysilane, γ-methacryloxypropyltributoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ -Acryloxypropylmethyldimethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ-acryloxymethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinylmethyldimethoxy Such as silane, and the like. Preferred are γ- (meth) acryloxypropyltrimethoxysilane and γ- (meth) acryloxypropyltriethoxysilane.

Examples of the monomer (b) having one ethylenically unsaturated group and a monofunctional or polyfunctional isocyanate group in one molecule include 2-isocyanato nattoethyl (meth) acrylate and 2-isocyanato ethoxyethyl. (Meth) acrylate and the like.

Examples of the monomer (c) having one ethylenically unsaturated group and a monofunctional or polyfunctional blocked isocyanate group in one molecule include (meth) acrylic acid 2- (0- [1′-methyl). Propylideneamino] carboxyamino) ethyl, 2-[(3,5-dimethylpyrazolyl) carbonylamino] ethyl (meth) acrylate, diethyl 2- (2- (meth) acryloyloxyethylcarbamoyl) malonate, and the like.

In the present invention, the blocked isocyanate group means that, under normal conditions, the isocyanate group is protected with other functional groups to suppress the reactivity of the isocyanate group, while deprotecting by heating to regenerate the active isocyanate group. It shows the isocyanate block body which can be.

  Moreover, as a monomer (c), a commercial item can be used, and it can also prepare and use by a well-known method. For example, an isocyanate compound having an ethylenically unsaturated bond and a blocking agent are stirred in a solvent at a temperature of about 0 to 200 ° C., and known separation and purification means such as concentration, filtration, extraction, crystallization and distillation are performed. It can obtain by separating using.

Examples of the monomer (d) having one ethylenically unsaturated group and a monofunctional or polyfunctional alkylolamide group in one molecule include N-methylolacrylamide and N, N-di (methylol) acrylamide. And alkylol (meth) acrylamides such as N-methylol-N-methoxymethyl (meth) acrylamide, hydroxyethyl (meth) acrylamide, and dihydroxyethyl (meth) acrylamide.

In the present invention, the monomers contained in the monomers (a) to (d) are preferably 0.1 to the total amount of ethylenically unsaturated monomers (100% by weight in total) used for emulsion polymerization. It is 20% by weight, particularly preferably 0.5 to 5.0% by weight. If it is less than 0.1% by weight, the amount of the functional group capable of crosslinking with the hydroxyl group on the surface of the current collector decreases, and it cannot sufficiently contribute to the improvement of water resistance. On the other hand, if it exceeds 20% by weight, there is a concern that the battery performance will be adversely affected due to overcrowding, and there will be a problem in the polymerization stability during emulsion polymerization, or even if it can be polymerized, the storage stability will be a problem May occur. As the monomers (a) to (d), it is preferable to use the monomer (c) from the viewpoint of stability during polymerization and cycle characteristics of the electricity storage device. It is more preferable to use (c) in combination.

<Monomer (e) having an ethylenically unsaturated group other than the monomers (a) to (d)>
In addition to the monomers (a) to (d), the resin fine particles (A) of the present invention include a monomer (e) having an ethylenically unsaturated group other than the monomers (a) to (d). It can be obtained by emulsion polymerization at the same time.

The monomer (e) is not particularly limited as long as it is a monomer other than the monomers (a) to (d) and has an ethylenically unsaturated group, but one ethylene per molecule. Monomer (f) having a polymerizable unsaturated group and an alkyl group having 8 to 18 carbon atoms and / or a monomer (g) having one ethylenically unsaturated group in one molecule and a cyclic structure It is preferable to contain. The content of the monomer (f) and / or (g) is not particularly limited. However, when 30 to 95% by weight is contained in the total 100% of the monomers (a) to (e), the particles are synthesized. It is preferable because of excellent particle stability and adhesion. If it is less than 30% by weight, the electrolyte solution resistance may be adversely affected. If it exceeds 95% by weight, the stability during particle synthesis will be adversely affected, or even if synthesis is possible, the temporal stability of the particles will be impaired. There is a case.

Examples of the monomer (f) having one ethylenically unsaturated group and an alkyl group having 8 to 18 carbon atoms in one molecule include 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and myristyl. (Meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate and the like can be mentioned.

Examples of the monomer (g) having one ethylenically unsaturated group and a cyclic structure in one molecule include alicyclic ethylenically unsaturated monomers and aromatic ethylenically unsaturated monomers. It is done. Examples of the alicyclic ethylenically unsaturated monomer include cyclohexyl (meth) acrylate and isobornyl (meth) acrylate, and examples of the aromatic ethylenically unsaturated monomer include benzyl (meth) acrylate. Phenoxyethyl (meth) acrylate, styrene, α-methylstyrene, 2-methylstyrene, chlorostyrene, allylbenzene, ethynylbenzene and the like.

Other monomers (e) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, pentyl (meth) acrylate, heptyl (meth) acrylate Alkyl group-containing ethylenically unsaturated monomers such as; nitrile group-containing ethylenically unsaturated monomers such as (meth) acrylonitrile; perfluoromethylmethyl (meth) acrylate, perfluoroethylmethyl (meth) acrylate, 2- Perfluorobutylethyl (meth) acrylate, 2-perfluorohexylethyl (meth) acrylate, 2-perfluorooctylethyl (meth) acrylate, 2-perfluoroisononylethyl (meth) acrylate, 2-perfluorononylethyl ( Meta) Acu 2-perfluorodecylethyl (meth) acrylate, perfluoropropylpropyl (meth) acrylate, perfluorooctylpropyl (meth) acrylate, perfluorooctyl amyl (meth) acrylate, perfluorooctyl undecyl (meth) acrylate, etc. Perfluoroalkyl group-containing ethylenically unsaturated monomer having a perfluoroalkyl group having 1 to 20 carbon atoms; perfluoroalkyl such as perfluorobutylethylene, perfluorohexylethylene, perfluorooctylethylene, and perfluorodecylethylene , Perfluoroalkyl group-containing ethylenically unsaturated compounds such as alkylenes; polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, Toxipolyethylene glycol (meth) acrylate, propoxypolyethylene glycol (meth) acrylate, n-butoxypolyethylene glycol (meth) acrylate, n-pentoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, polypropylene glycol (meth) Acrylate, methoxypolypropylene glycol (meth) acrylate, ethoxypolypropyleneglycol (meth) acrylate, propoxypolypropyleneglycol (meth) acrylate, n-butoxypolypropyleneglycol (meth) acrylate, n-pentoxypolypropyleneglycol (meth) acrylate, phenoxypolypropyleneglycol (Meth) acrylate, polytetra Ethylene having a polyether chain such as methylene glycol (meth) acrylate, methoxypolytetramethylene glycol (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate, hexaethylene glycol (meth) acrylate, methoxyhexaethylene glycol (meth) acrylate Ethylenically unsaturated compounds having a polyester chain such as lactone-modified (meth) acrylate; (meth) acrylic acid dimethylaminoethyl methyl chloride salt, trimethyl-3- (1- (meth) acrylamide-1,1 -Dimethylpropyl) ammonium chloride, trimethyl-3- (1- (meth) acrylamidopropyl) ammonium chloride, and trimethyl-3- (1- (meth) acrylic Quaternary ammonium base-containing ethylenically unsaturated compounds such as do-1,1-dimethylethyl) ammonium chloride; vinyl acetate, vinyl butyrate, vinyl propionate, vinyl hexanoate, vinyl caprylate, vinyl laurate, vinyl palmitate, Fatty acid vinyl compounds such as vinyl stearate; Vinyl ether ethylenically unsaturated monomers such as butyl vinyl ether and ethyl vinyl ether; 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene Α-olefinic ethylenically unsaturated monomers such as allyl monomers such as allyl acetate and allyl cyanide; vinyl monomers such as vinyl cyanide, vinylcyclohexane and vinylmethylketone; acetylene and ethynyltoluene Such as ethynyl monomer can give.

Examples of the other monomer (e) include allyl (meth) acrylate, 1-methylallyl (meth) acrylate, 2-methylallyl (meth) acrylate, 1-butenyl (meth) acrylate, ( 2-butenyl (meth) acrylate, 3-butenyl (meth) acrylate, 1,3-methyl-3-butenyl (meth) acrylate, 2-chloroallyl (meth) acrylate, 3-chloroallyl (meth) acrylate, O-allylphenyl (meth) acrylate, 2- (allyloxy) ethyl (meth) acrylate, allyl lactyl (meth) acrylate, citronellyl (meth) acrylate, geranyl (meth) acrylate, rosinyl (meth) acrylate, Cinnamyl (meth) acrylate, diallyl maleate, diallyl itaconic acid, vinyl (meth) acrylate, croto Ethylenically unsaturated group-containing (meth) acrylate esters such as vinyl acid vinyl, vinyl oleate, vinyl linolenate, 2- (2′-vinyloxyethoxy) ethyl (meth) acrylate; ethylene di (meth) acrylate Glycol, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,1,1-tris diacrylate Polyfunctional (meth) acrylates such as hydroxymethylethane, 1,1,1-trishydroxymethylethane triacrylate, 1,1,1-trishydroxymethylpropanetriacrylic acid; divinylbenzene, divinyl adipate, etc. Divinyls; diallyl isophthalate, Tal diallyl monomer having two or more ethylenically unsaturated group in the molecule, such as diallyl such as diallyl maleate.

Examples of other monomers (e) include maleic acid, fumaric acid, itaconic acid, citraconic acid, or alkyl or alkenyl monoesters thereof, phthalic acid β- (meth) acryloxyethyl monoester, Isophthalic acid β- (meth) acryloxyethyl monoester, terephthalic acid β- (meth) acryloxyethyl monoester, succinic acid β- (meth) acryloxyethyl monoester, acrylic acid, methacrylic acid, crotonic acid, cinnamic Carboxyl group-containing ethylenically unsaturated monomers such as acids; tertiary butyl group-containing ethylenically unsaturated monomers such as tertiary butyl (meth) acrylate; sulfonic acid group-containing ethylenes such as vinyl sulfonic acid and styrene sulfonic acid Unsaturated monomer; (2-hydroxyethyl) methacrylate Phosphoric acid group-containing ethylenically unsaturated monomers such as acid phosphate; diacetone (meth) acrylamide, acrolein, N-vinylformamide, vinyl methyl ketone, vinyl ethyl ketone, acetoacetoxyethyl (meth) acrylate, acetoacetoxypropyl Keto group-containing ethylenically unsaturated monomers (monomers having one ethylenically unsaturated group and a keto group in one molecule) such as (meth) acrylate and acetoacetoxybutyl (meth) acrylate It is done.

Examples of the other monomer (e) include primary amide group-containing ethylenically unsaturated monomers such as (meth) acrylamide; N-methoxymethyl- (meth) acrylamide, N-ethoxymethyl- ( Monoalkoxy (meth) acrylamides such as (meth) acrylamide, N-propoxymethyl- (meth) acrylamide, N-butoxymethyl- (meth) acrylamide, N-pentoxymethyl- (meth) acrylamide; N, N-di ( Methoxymethyl) acrylamide, N-ethoxymethyl-N-methoxymethylmethacrylamide, N, N-di (ethoxymethyl) acrylamide, N-ethoxymethyl-N-propoxymethylmethacrylamide, N, N-di (propoxymethyl) acrylamide N-butoxymethyl-N- (propoxy Methyl) methacrylamide, N, N-di (butoxymethyl) acrylamide, N-butoxymethyl-N- (methoxymethyl) methacrylamide, N, N-di (pentoxymethyl) acrylamide, N-methoxymethyl-N- ( Dialkoxy (meth) acrylamides such as pentoxymethyl) methacrylamide; dialkylamino (meth) acrylamides such as N, N-dimethylaminopropylacrylamide and N, N-diethylaminopropylacrylamide; N, N-dimethylacrylamide, N And dialkyl (meth) acrylamides such as N-diethylacrylamide; keto group-containing (meth) acrylamides such as diacetone (meth) acrylamide.

Examples of the other monomer (e) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2- (meth) acryloyloxy. Examples thereof include ethyl-2-hydroxyethylphthalic acid, glycerol mono (meth) acrylate, 4-hydroxyvinylbenzene, 1-ethynyl-1-cyclohexanol, and allyl alcohol.

Among other monomers (e), ethylene having an amide group, a carboxyl group, a tertiary butyl group (tertiary butanol is eliminated by heat to form a carboxyl group), a sulfonic acid group, and a phosphoric acid group The resin fine particles obtained by copolymerizing the polymerizable unsaturated monomer have the effect of improving the physical properties such as adhesion of the current collector, with the functional groups remaining in the particles and on the surface after polymerization. It can be preferably used because it may prevent aggregation during synthesis or may maintain the stability of particles after synthesis.

When using monomers containing an amide group, carboxyl group, tertiary butyl group, sulfonic acid group, and phosphoric acid group, in the whole ethylenically unsaturated monomer (100% by weight in total) used for emulsion polymerization Is preferably contained in an amount of 0.1 to 10% by weight, more preferably 1 to 5% by weight. When the monomer containing an amide group, a carboxyl group, a tertiary butyl group, a sulfonic acid group, and a phosphoric acid group is less than 0.1% by weight, the stability of the particles may be deteriorated. On the other hand, if it exceeds 10% by weight, the resin fine particles and the binder composition may become too hydrophilic, resulting in poor electrolytic solution resistance.

These monomers can be used in combination of two or more kinds of monomers in order to adjust the polymerization stability of the particles, the glass transition temperature, and also the film formability and film properties. Further, for example, by using (meth) acrylonitrile in combination, there is an effect that rubber elasticity is exhibited.

<Method for producing resin fine particles (A)>
The resin fine particles (A) of the present invention can be synthesized by a conventionally known emulsion polymerization method.

<Emulsifier used in emulsion polymerization>
As the emulsifier used in the emulsion polymerization in the present invention, a conventionally known one such as a reactive emulsifier having an ethylenically unsaturated group or a non-reactive emulsifier having no ethylenically unsaturated group may be arbitrarily used. it can.

Reactive emulsifiers having an ethylenically unsaturated group can be further roughly classified into anionic and nonionic nonionic ones. Especially when an anionic reactive emulsifier or nonionic reactive emulsifier having an ethylenically unsaturated group is used, the dispersion particle size of the copolymer becomes fine and the particle size distribution becomes narrow. In particular, the resistance to electrolytic solution can be improved. These anionic reactive emulsifiers or nonionic reactive emulsifiers having an ethylenically unsaturated group may be used singly or in combination.

Although it does not specifically limit as an anionic reactive emulsifier which has an ethylenically unsaturated group, Specifically, alkyl ether type (For example, Dairon Kogyo Seiyaku Co., Ltd. product Aqualon KH-05, KH-10 is used. , KH-20, Adeka Soap SR-10N, SR-20N manufactured by ADEKA Corporation, Latemu PD-104 manufactured by Kao Corporation, etc .; Sulfosuccinic acid ester-based (commercially available products include Latemul S-made by Kao Corporation, for example) 120, S-120A, S-180P, S-180A, Sanyo Kasei Co., Ltd. Eleminol JS-2, etc.); alkyl phenyl ether type or alkyl phenyl ester type (commercially available products include, for example, Daiichi Kogyo Seiyaku Co., Ltd. Aqualon H-2855A, H-3855B, H-3855C, H-3856, HS- 5, HS-10, HS-20, HS-30, Adeka Soap SDX-222, SDX-223, SDX-232, SDX-233, SDX-259, SE-10N, SE-20N, etc. manufactured by ADEKA Corporation ); (Meth) acrylate sulfate (based on commercial products such as Antox MS-60, MS-2N, Sanyo Kasei Kogyo Co., Ltd., Eleminol RS-30, etc.); Phosphate ester ( Examples of commercially available products include H-3330PL manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Adeka Soap PP-70 manufactured by ADEKA Corporation, and the like.

Although it does not specifically limit as a nonionic reactive emulsifier which has an ethylenically unsaturated group, Specifically, for example, an alkyl ether type (As a commercial item, for example, Adeka Soap ER-10, ER-20 by ADEKA Corporation) , ER-30, ER-40, LATEMUL PD-420, PD-430, PD-450, etc. manufactured by Kao Corporation); (Aqualon RN-10, RN-20, RN-30, RN-50 manufactured by company, Adeka Soap NE-10, NE-20, NE-30, NE-40 manufactured by ADEKA Co., Ltd.); (meth) acrylate sulfate (As commercial products, for example, RMA-564, RMA-568, RMA manufactured by Nippon Emulsifier Co., Ltd. 1114, etc.) and the like.

When the resin fine particles (A) of the present invention are obtained by emulsion polymerization, a non-reactive emulsifier having no ethylenically unsaturated group may be used in combination with the reactive emulsifier having an ethylenically unsaturated group as described above. it can. Non-reactive emulsifiers can be broadly classified into non-reactive anionic emulsifiers and non-reactive nonionic emulsifiers.

Examples of non-reactive nonionic emulsifiers include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether; polyoxyethylene alkyl such as polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether Sorbitan monolaurate, sorbitan monostearate, sorbitan higher fatty acid esters such as sorbitan trioleate; polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate; polyoxyethylene monolaurate, Polyoxyethylene higher fatty acid esters such as polyoxyethylene monostearate; oleic acid monoglyceride, stearic acid monoglyceride Glycerine higher fatty acid esters such as chloride, polyoxyethylene-polyoxypropylene block copolymers, and the like can be exemplified polyoxyethylene distyrenated phenyl ether.

Examples of non-reactive anionic emulsifiers include higher fatty acid salts such as sodium oleate; alkyl aryl sulfonates such as sodium dodecylbenzene sulfonate; alkyl sulfate esters such as sodium lauryl sulfate; polyoxyethylene lauryl ether Polyoxyethylene alkyl ether sulfates such as sodium sulfate; polyoxyethylene alkylaryl ether sulfates such as polyoxyethylene nonylphenyl ether sodium sulfate; sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, polyoxyethylene lauryl sulfosuccinic acid Alkylsulfosuccinic acid ester salts such as sodium and derivatives thereof; polyoxyethylene distyrenated phenyl ether And the like can be exemplified sulfuric ester salts.

The amount of the emulsifier used in the present invention is not necessarily limited, and can be appropriately selected according to physical properties required when the resin fine particles (A) are finally used as a binder composition for an electricity storage device underlayer. . For example, with respect to the total of 100 parts by weight of the ethylenically unsaturated monomers, the emulsifier is usually preferably 0.1 to 30 parts by weight, and 0.3 to 20 parts by weight for reasons of stability during polymerization. It is more preferable that it is in the range of 0.5 to 10 parts by weight.

In emulsion polymerization of the resin fine particles (A) of the present invention, a water-soluble protective colloid can be used in combination. Examples of the water-soluble protective colloid include, for example, acrylic polymers, styrene acrylic polymers, styrene maleic acid copolymers, partially saponified polyvinyl alcohols, fully saponified polyvinyl alcohols, polyvinyl alcohols such as modified polyvinyl alcohols; hydroxyethyl cellulose, hydroxypropyl cellulose , Cellulose derivatives such as carboxymethyl cellulose salt; natural polysaccharides such as guar gum and the like, and these can be used alone or in a combination of plural kinds. The amount of the water-soluble protective colloid used is 0.1 to 10 parts by weight, more preferably 0.5 to 100 parts by weight with respect to a total of 100 parts by weight of the ethylenically unsaturated monomer for reasons of stability during polymerization. 5 parts by weight.

<Aqueous medium used in emulsion polymerization>
Examples of the aqueous medium used for emulsion polymerization of the resin fine particles (A) of the present invention include water, and hydrophilic organic solvents can also be used as long as the object of the present invention is not impaired.

<Polymerization initiator used in emulsion polymerization>
The polymerization initiator used for obtaining the resin fine particles (A) of the present invention is not particularly limited as long as it has the ability to initiate radical polymerization, and a known oil-soluble polymerization initiator or water-soluble polymerization initiator may be used. Can be used.

The oil-soluble polymerization initiator is not particularly limited, and examples thereof include benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl hydroperoxide, tert-butyl peroxy (2-ethylhexanoate), and tert-butyl peroxide. Organic peroxides such as oxy-3,5,5-trimethylhexanoate, di-tert-butyl peroxide; 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4- Examples thereof include azobis compounds such as dimethylvaleronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1′-azobiscyclohexane-1-carbonitrile. These can be used alone or in combination of two or more. These polymerization initiators are preferably used in an amount of 0.1 to 10.0 parts by weight with respect to 100 parts by weight of the ethylenically unsaturated monomer.

In the present invention, it is preferable to use a water-soluble polymerization initiator. For example, ammonium persulfate, potassium persulfate, hydrogen peroxide, 2,2′-azobis (2-methylpropionamidine) dihydrochloride and the like are conventionally known. A thing can be used conveniently. Moreover, when performing emulsion polymerization, a reducing agent can be used together with a polymerization initiator if desired. Thereby, it becomes easy to accelerate the emulsion polymerization rate or to perform the emulsion polymerization at a low temperature. Examples of such a reducing agent include reducing organic compounds such as metal salts such as ascorbic acid, ersorbic acid, tartaric acid, citric acid, glucose, and formaldehyde sulfoxylate, sodium thiosulfate, sodium sulfite, sodium bisulfite, Examples include reducing inorganic compounds such as sodium bisulfite, ferrous chloride, Rongalite, thiourea dioxide, and the like. These reducing agents are preferably used in an amount of 0.05 to 5.0 parts by weight with respect to 100 parts by weight of the total ethylenically unsaturated monomer.

<Conditions for emulsion polymerization>
In addition, it can superpose | polymerize by a photochemical reaction, radiation irradiation, etc. irrespective of an above described polymerization initiator. The polymerization temperature is not less than the polymerization start temperature of each polymerization initiator. For example, in the case of a peroxide-based polymerization initiator, it may be usually about 70 ° C. The polymerization time is not particularly limited, but is usually 2 to 24 hours.

<Other materials used for reaction>
Further, if necessary, sodium acetate, sodium citrate, sodium bicarbonate, etc. as a buffering agent, and octyl mercaptan, 2-ethylhexyl thioglycolate, octyl thioglycolate, stearyl mercaptan, lauryl mercaptan as a chain transfer agent A suitable amount of mercaptans such as t-dodecyl mercaptan can be used.

When a monomer having an acidic functional group such as a carboxyl group-containing ethylenically unsaturated monomer is used for the polymerization of the resin fine particles (A), it can be neutralized with a basic compound before or after the polymerization. Examples of the basic compound include ammonia or alkylamines such as trimethylamine, triethylamine and butylamine; alcohol amines such as 2-dimethylaminoethanol, diethanolamine, triethanolamine and aminomethylpropanol; morpholine. Highly volatile bases such as aminomethyl propanol and ammonia are preferred because they have a high effect of increasing the drying property.

<Characteristics of resin fine particles (A)>
<Glass transition temperature>
The glass transition temperature (hereinafter also referred to as Tg) of the resin fine particles (A) is preferably -30 to 70 ° C, more preferably -20 to 40 ° C, and further preferably -10 ° C to 30 ° C. When Tg is less than −30 ° C., the binder covers the conductive carbon material excessively, and the impedance tends to increase. Moreover, when Tg exceeds 70 degreeC, the softness | flexibility of a binder and adhesiveness will become scarce, and the adhesiveness to a current collection material and the moldability of a base layer may be inferior. The glass transition temperature is a value obtained using a DSC (differential scanning calorimeter).

The measurement of the glass transition temperature by DSC (differential scanning calorimeter) can be performed as follows. About 2 mg of resin obtained by drying resin fine particles (A) is weighed on an aluminum pan, the test container is set on a DSC measurement holder, and the endothermic peak of the chart obtained under the temperature rising condition of 10 ° C./min is read. The peak temperature at this time is defined as the glass transition temperature of the present invention.

<Particle structure>
In the present invention, the particle structure of the resin fine particles (A) may be a multilayer structure, so-called core-shell particles. For example, it is possible to localize a resin in which a monomer having a functional group is mainly polymerized in the core part or the shell part, or to provide a difference in Tg or composition between the core and the shell, thereby improving the curability and drying. Property, film formability, and mechanical strength of the binder can be improved.

<Particle size>
The average particle diameter of the resin fine particles (A) is preferably 10 to 500 nm, and more preferably 30 to 250 nm, from the viewpoint of the binding property of the conductive carbon material and the stability of the particles. Further, when a large amount of coarse particles exceeding 1 μm are contained, the stability of the particles is impaired, so that the coarse particles exceeding 1 μm are preferably at most 5% by weight. In addition, the average particle diameter in the present invention represents a volume average particle diameter and can be measured by a dynamic light scattering method.

The average particle diameter can be measured by the dynamic light scattering method as follows. The resin fine particle (A) dispersion is diluted with water 200 to 1000 times depending on the solid content. About 5 ml of the diluted solution is injected into a cell of a measuring device [Microtrack manufactured by Nikkiso Co., Ltd.], and after measuring the refractive index conditions of the solvent (water in the present invention) and the resin according to the sample, measurement is performed. The peak of the volume particle size distribution data (histogram) obtained at this time is defined as the average particle size of the present invention.

<Strength of coating film, elongation>
Furthermore, the strength and elongation of the coating film obtained by forming the resin fine particles (A) are 1.0 to 7.0 N / mm 2 in strength and 300 to 2000% in elongation from the point of toughness of the resin. It is more preferable that the strength is 2.0 to 5.5 N / mm 2 and the elongation is 400 to 1200%. If the strength is less than 1.0 N / mm 2, the holding power of the conductive carbon material and the binding force of the underlayer to the current collector may deteriorate, and if the strength exceeds 7.0 N / mm 2, The film becomes too rigid and the binding force is poor. When the elongation is less than 300%, the coating film is fragile and sufficient binding strength may not be obtained. Moreover, when elongation rate exceeds 2000%, the retention strength of an electroconductive carbon material and the binding force to the electrical power collector of a base layer may worsen. In addition, the intensity | strength and elongation rate of the coating film in this invention are the breaking strength and breaking elongation measured with Tensilon.

Measurement of the strength of the coating film with Tensilon and the elongation percentage can be performed by the following methods. The resin fine particles (A) are dried to prepare a sheet having a thickness of about 0.5 mm. The measurement specimen is cut out to 5 mm × 60 mm, and the film thickness is measured accurately. The measurement is performed under a constant temperature and humidity condition of a temperature of 23 ° C. and a humidity of 50% using a tensile tester [Tensilon manufactured by Orientec Co., Ltd.] with a chuck distance of 20 mm and a tensile speed of 50 mm / min. The breaking strength and breaking elongation calculated from the breaking strength and breaking elongation obtained by measurement in consideration of the film thickness are taken as the strength and elongation of the present invention.

<Elution rate>
Furthermore, the elution rate of the coating film obtained by forming the resin fine particles (A) of the present invention is preferably 50% or less, more preferably 30% or less. The elution rate is a coating obtained by forming resin fine particles into an organic solvent (herein, the organic solvent is a commonly used solvent such as methanol, ethanol, ethyl acetate, methyl ethyl ketone, toluene, cyclohexane, or It means a solvent used as a secondary battery electrolyte such as propylene carbonate and ethyl carbonate) and is a resin component dissolved in an organic solvent after being immersed in a certain time. In the case of a resin having a high elution rate, the inherent binding property of the binder cannot be maintained when used in an electrolytic solution, and the base layer may be peeled off, which may cause a problem of deterioration in the performance of the electricity storage device.

Usually, the resin elution rate can be measured by the following method. The resin fine particles (A) are dried to prepare a test piece of about 0.2 g. The measurement specimen is cut out to 2 cm × 2 cm and the weight is measured accurately. In this study, the organic solvent for elution rate measurement is propylene carbonate, and the test is immersed in the organic solvent and then allowed to stand at 70 ° C. for 24 hours to sufficiently immerse the organic solvent. After immersion, the organic solvent remaining in the test piece is completely removed by oven drying, and the weight change is measured. By calculating the resin content dissolved in the organic solvent based on the weight change before and after the immersion, the elution rate of the present invention is obtained.

<Usage mode of resin fine particles (A)>
The resin fine particles (A) can be used for a base layer used for a positive electrode and a negative electrode of a secondary battery. In addition, it can be used for an energy device, that is, an underlayer for an electrode plate such as a capacitor, a lithium ion capacitor, or a solar cell.
The resin fine particles (A) can be used as a binder composition by further adding a water-soluble resin (B).

<Water-soluble resin (B)>
The water-soluble resin (B) of the present invention is 1 g of resin in 99 g of water at 25 ° C., stirred and allowed to stand at 25 ° C. for 24 hours, and then the resin can be completely dissolved in water without separation and precipitation. It is a thing.

The water-soluble resin (B) is not particularly limited as long as it is water-soluble and has a hydroxyl group as described above. For example, acrylic resin, polyurethane resin, polyester resin, polyamide resin, polyimide resin, Examples thereof include polymer compounds including polysaccharide resins such as allylamine resin, phenol resin, epoxy resin, phenoxy resin, urea resin, melamine resin, alkyd resin, formaldehyde resin, silicon resin, fluororesin, and carboxymethylcellulose. Moreover, if it is water-soluble, the modified substance, mixture, or copolymer of these resin may be sufficient. These binders can be used alone or in combination.

Although the molecular weight of water-soluble resin (B) is not specifically limited, It is preferable that a weight average molecular weight is 1,000-1,000,000, Furthermore, 5,000-500,000 are more preferable. If the weight average molecular weight is less than 1,000, the adhesion effect to the current collector may not be sufficient, and if the weight average molecular weight exceeds 1,000,000, the viscosity of the compound may increase. There may be a case where handling properties at the time of electrode preparation are deteriorated. In addition, the said weight average molecular weight is the value of polystyrene conversion measured by the gel permeation chromatography (GPC) method.

It is preferable that the water-soluble resin (B) contains a hydroxyl group because the water-soluble resin (B) is cross-linked with the resin fine particles (A) to further improve adhesion and water resistance. Preferable specific examples include polysaccharides such as carboxymethyl cellulose, polyvinyl alcohol and the like.

The hydroxyl value (mgKOH / g) of the water-soluble resin (B) is not particularly limited, but is preferably 10 or more and 1275 or less, more preferably 50 or more and 1275 or less, and still more preferably 200 or more and 1000 or less. When the hydroxyl value is less than 10, the crosslinking with the resin fine particles (A) becomes insufficient, and the adhesion effect to the current collector may not be sufficient, and cannot sufficiently contribute to the improvement of water resistance.

The water-soluble resin (B) is preferably added in an amount of 0.1 to 200 parts by weight, more preferably 1 to 120 parts by weight, and 3 to 67 parts by weight with respect to 100 parts by weight of the solid content of the resin fine particles (A). Further preferred. Most preferably, it is 3 to 25 parts by weight. If the proportion of the water-soluble resin (B) is too small, the amount of functional groups that contribute to the adhesion of the current collector will be small, and it may not be possible to sufficiently contribute to improving the adhesion of the current collector. On the other hand, if the ratio of the water-soluble resin binder (B) is too large, it may cause adverse effects on the binder performance such as leakage of the water-soluble resin (B) into the electrolyte solution. Moreover, water resistance may be insufficient, and a good underlayer may not be formed.
Furthermore, two or more types of water-soluble resins (B) can be used in combination.

<Ink for underlying layer>
By mixing the resin fine particles (A), the water-soluble resin (B), and the conductive carbon material (C), the ink for the underlayer can be prepared. Moreover, the ink for base layers can be created by mix | blending a conductive carbon material (C) with the said binder composition. The undercoat layer for an electricity storage device can be produced by applying the undercoat layer ink to a current collector and drying it. The base layer ink may further use an additive that is not an active material, if necessary.

In the present invention, the ratio of the binder composition to the total solid content of the base layer ink is preferably 25% by weight or more and 80% by weight or less, more preferably 30% by weight or more and 65% by weight or less. When there are too few binder compositions, durability, such as adhesiveness of a coating film, may not be maintained, and on the other hand, when there are too few conductive carbon materials, the electroconductivity of a base layer may fall.

The conductive auxiliary agent (C) in the underlayer ink is not particularly limited as long as it is a conductive carbon material. Carbon black, graphite, conductive carbon fibers (carbon nanotubes, carbon nanofibers, carbon fibers) ), Fullerene or the like can be used alone or in combination of two or more. Carbon black and graphite are preferred from the viewpoints of conductivity, availability, and cost. Examples of carbon black include acetylene black and ketjen black.

<Current collector with electrode, electrode>
The underlayer ink can be applied to the current collector and dried to form the underlayer, thereby obtaining the current collector with the underlayer for the electricity storage device. Alternatively, the conductive composition of the present invention can be applied and dried on a current collector to form a base layer, and an electrode plate layer can be provided on the base layer to obtain an electrode for an electricity storage device. The electrode plate layer provided on the base layer can be formed using, for example, a mixture ink.

(Current collector)
The material and shape of the current collector are not particularly limited, and an optimal material for various power storage devices can be appropriately selected.

  For example, examples of the material for the current collector include metals and alloys such as aluminum, copper, nickel, titanium, and stainless steel. In the case of a lithium ion battery, aluminum is particularly preferable as the positive electrode material, and copper is preferable as the negative electrode material. In general, a flat foil is used as the shape, but a roughened surface, a perforated foil, or a mesh current collector can also be used.

  The method for coating the current collector with the ink for forming the underlayer or the composite ink is not particularly limited, and a known method can be used.

  Specific examples include die coating method, dip coating method, roll coating method, doctor coating method, knife coating method, spray coating method, gravure coating method, screen printing method or electrostatic coating method, and the like. Examples of methods that can be used include standing drying, blower dryers, hot air dryers, infrared heaters, and far-infrared heaters, but are not particularly limited thereto.

<Composite ink>
As the composite ink, a general composite ink for an electricity storage device can be used. The composite ink contains an active material and a solvent as essential components, and may contain a conductive additive and a binder as necessary.

<Power storage device>
By using the above electrode for at least one of the positive electrode and the negative electrode, an electricity storage device such as a secondary battery or a capacitor can be obtained.

Secondary batteries include lithium ion secondary batteries, sodium ion secondary batteries, magnesium ion secondary batteries, alkaline secondary batteries, lead storage batteries, sodium sulfur secondary batteries, lithium air secondary batteries, etc. An electrolyte solution, a separator, and the like that are conventionally known for each secondary battery can be appropriately used.
Examples of the capacitor include an electric double layer capacitor, a lithium ion capacitor, and the like, and an electrolyte, a separator, and the like that are conventionally known for each capacitor can be appropriately used.

(Electrolyte)
A case of a lithium ion secondary battery will be described as an example. As the electrolytic solution, an electrolyte containing lithium dissolved in a non-aqueous solvent is used.

As the electrolyte, LiBF ₄ , LiClO ₄ , LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, LiC ₄ F ₉ SO ₃ , Li (CF ₃ SO ₂ ) ₃ C , LiI, LiBr, LiCl, LiAlCl , LiHF 2, LiSCN, or LiBPh ₄ etc. but are not limited to.

Although it does not specifically limit as a non-aqueous solvent, For example, carbonates, such as ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, ethylmethyl carbonate, and diethyl carbonate; γ-butyrolactone, γ-valerolactone, and γ- Lactones such as octanoic lactone; tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,2-methoxyethane, 1,2-ethoxyethane, and 1,2 -Glymes such as dibutoxyethane; esters such as methyl formate, methyl acetate, and methyl propionate; sulfoxides such as dimethyl sulfoxide and sulfolane; and nitriles such as acetonitrile. It is below. These solvents may be used alone or in combination of two or more.

Furthermore, the electrolyte solution may be a polymer electrolyte that is held in a polymer matrix and made into a gel. Examples of the polymer matrix include, but are not limited to, an acrylate resin having a polyalkylene oxide segment, a polyphosphazene resin having a polyalkylene oxide segment, and a polysiloxane having a polyalkylene oxide segment.

(separator)
Examples of the separator include, but are not limited to, a polyethylene nonwoven fabric, a polypropylene nonwoven fabric, a polyamide nonwoven fabric and those obtained by subjecting them to a hydrophilic treatment.

(Battery structure / configuration)
The structure of the lithium ion secondary battery, the electric double layer capacitor, and the lithium ion capacitor using the composition of the present invention is not particularly limited, and is usually composed of a positive electrode and a negative electrode, and a separator provided as necessary. Various shapes can be formed according to the purpose of use, such as a paper type, a cylindrical type, a button type, and a laminated type.

EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the examples and comparative examples, “part” represents “part by weight”.

(Measurement of glass transition temperature of resin fine particles (A))
It was measured by the method described in this specification.
(Measurement of resin fine particle (A) particle size)
It was measured by the dynamic light scattering method described herein.
(Hydroxyl value of water-soluble resin (B))
The theoretical value was calculated by calculation based on the molecular formula.

<Preparation of resin fine particle (A) aqueous dispersion>
[Example 1]
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser was charged with 40 parts of ion-exchanged water and 0.2 part of Adeka Soap SR-10 (manufactured by ADEKA) as a surfactant. 56.0 parts lauryl acrylate, 37.8 parts cyclohexyl methacrylate, 5.0 parts ethyl acrylate, 1.0 part methacrylic acid, 0.2 part γ-methacryloxypropyltrimethoxysilane, 53 parts ion-exchanged water, and surfactant 1% of the pre-emulsion in which 1.8 parts of ADEKA rear soap SR-10 (manufactured by ADEKA Co., Ltd.) was mixed in advance was further added. After raising the internal temperature to 70 ° C. and sufficiently substituting with nitrogen, 10% of 10 parts of a 5% aqueous solution of potassium persulfate was added to initiate polymerization. After maintaining the inside of the reaction system at 70 ° C. for 5 minutes, the remaining pre-emulsion and the remaining 5% aqueous solution of potassium persulfate were dropped over 3 hours while maintaining the internal temperature at 70 ° C., and stirring was further continued for 2 hours. . After confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30 ° C. 25% aqueous ammonia was added to adjust the pH to 5.0, and the solid content was adjusted to 40% with ion-exchanged water to obtain the functional group-containing resin fine particle aqueous dispersion of Example 1. In addition, solid content was calculated | required by 150 degreeC 20 minute baking residue.

[Examples 2 to 13, Comparative Examples 1 to 3]
The compounding compositions shown in Table 1 were synthesized in the same manner as in Example 1 to obtain resin fine particle aqueous dispersions of Examples 2 to 13 and Comparative Examples 1 and 2. Comparative Example 3 could not be stably synthesized. In the present specification, Examples 1, 2, 4 to 6, 11, 13, and examples using these resins are reference examples.

[Explanation of monomer]
LA: lauryl acrylate 2EHA: 2-ethylhexyl acrylate CHMA: cyclohexyl methacrylate MMA: methyl methacrylate EA: ethyl acrylate MAA: methacrylic acid AAm: acrylamide DAAm: diacetone acrylamide HEMA: 2-hydroxyethyl acrylate SSMA: sodium styrenesulfonate DBS: Divinylbenzene

<Preparation of ink for forming the underlayer and current collector with the underlayer>
[Example 14]
With respect to 100 parts of the solid content of the resin fine particle aqueous dispersion obtained in Example 1, 67 parts of acetylene black and 33 parts of carboxymethylcellulose as a water-soluble resin are added, respectively, and ion exchange is performed so that the solid content is 8%. After adding water, the mixture was kneaded to prepare a base layer ink. Furthermore, this underlayer ink was applied on a 20 μm thick aluminum foil serving as a current collector using a bar coater, and then dried by heating to obtain a current collector with an underlayer of Example 14 having a thickness of 1.2 μm. The body was made.
[Examples 15 to 39, Comparative Examples 4 to 7]
In the compounding composition shown in Table 2, it mix | blends by the method similar to Example 14, and it apply | coats on the electrical power collector shown in Table 2 by the same method, Under Examples 15-39 and Comparative Examples 4-7 A current collector with a stratum was created.

（表２中の水溶性樹脂（Ｂ））
・ CMC：カルボキシメチルセルロース（水酸基価３７０ＫＯＨｍｇ／ｇ、分子量Ｍｗ１０００００）
・ PVA：ポリビニルアルコール（水酸基価８５０ＫＯＨｍｇ／ｇ、分子量Ｍｗ７００００）
・ PEO：ポリエチレンオキサイド（水酸基価５ＫＯＨｍｇ／ｇ、分子量Ｍｗ２００００）
・ スチレンアクリル共重合体：スチレン７５％アクリル酸２５％の共重合体（水酸基無し、分子量Ｍｗ１００００）

(Water-soluble resin (B) in Table 2)
CMC: Carboxymethyl cellulose (hydroxyl value 370 KOHmg / g, molecular weight Mw 100,000)
PVA: polyvinyl alcohol (hydroxyl value 850 KOHmg / g, molecular weight Mw 70000)
PEO: Polyethylene oxide (hydroxyl value 5KOHmg / g, molecular weight Mw 20000)
-Styrene acrylic copolymer: Copolymer of styrene 75% acrylic acid 25% (no hydroxyl group, molecular weight Mw 10,000)

<Evaluation of adhesion of underlayer>
Using a knife on the surface of each current collector with an underlayer, six incisions were made from the underlayer to the depth reaching the current collector, both vertically and horizontally at intervals of 2 mm, to make grid cuts. Adhesive tape was applied to the cut and immediately peeled off, and the degree of dropping of the underlayer was determined by visual judgment. The evaluation criteria are shown below. The evaluation results are shown in Table 2.
○: “No peeling”
○ △: “Slightly peeled off (a level where there is no practical problem)”
×: “Peeling at most parts”
XX: “Completely peeled”
<Evaluation of water resistance of underlayer>

The surface of the base layer produced above was rubbed with a cotton cloth containing water to evaluate the water resistance. When applying the water-based composite ink onto the underlayer, water resistance is important so that the underlayer does not collapse. The evaluation criteria are shown below, and the evaluation results are shown in Table 2.

○: “No shaving is seen (a level where there is no practical problem)”
○ △: “The foundation layer is slightly scraped and attached to the cotton cloth, but the surface of the current collector is not exposed (although there is a problem, it can be used)”
×: “Underlayer is shaved and current collector surface is partially exposed”
XX: “Underly layer is completely scraped off”

<Creation of composite ink for positive electrode of lithium ion secondary battery for evaluation>
The solid content of 100 parts of polytetrafluoroethylene 30-J (Mitsui / DuPont Fluorochemicals Co., Ltd., 60% aqueous dispersion) is 3,000 parts of acetylene and lithium iron phosphate (LiFePO4) as the positive electrode active material. 167 parts of black and 200 parts of carboxymethyl cellulose as a thickener were added, ion-exchanged water was added so that the solid content was 52%, and kneaded to prepare a lithium ion battery positive electrode mixture ink.
<Creation of ink for negative electrode for lithium ion secondary battery for evaluation>
3,000 parts of artificial graphite as negative electrode active material and 33 parts of carboxymethylcellulose as a thickener are added to 100 parts of solid content of 40% aqueous dispersion of styrene butadiene latex so that the solid content is 50%. After ion-exchanged water was added to the mixture, the mixture was kneaded to prepare a negative electrode mixture ink for lithium ion batteries.

<Creation of a lithium ion secondary battery positive electrode with an underlayer>
[Example 40]
After applying the positive electrode mixture ink for evaluation lithium ion battery to the current collector with the underlayer of Example 14 using a doctor blade, it was dried by heating under reduced pressure, and rolled by a roll press, resulting in a thickness of 85 μm. A positive electrode for a lithium ion secondary battery with an underlayer of Example 40 was produced.
[Examples 41 to 52, Comparative Examples 8 and 9]
Except having used the collector with a base layer shown in Table 3, it was carried out similarly to the lithium ion secondary battery positive electrode with a base layer of Example 40, and lithium ion with a base layer of Examples 41-52 and Comparative Examples 8 and 9 A secondary battery positive electrode was prepared.
<Creation of counter electrode 1 for evaluation (positive electrode for lithium ion secondary battery without base layer)>
A counter electrode for evaluation 1 was prepared in the same manner as in Example 40 except that an aluminum foil without a base layer applied was used as a current collector.

<Creation of negative electrode for lithium ion secondary battery with underlying layer>
[Example 53]
After applying the negative electrode mixture ink for a lithium ion battery for evaluation to the current collector with the underlayer of Example 27 using a doctor blade, it was dried by heating under reduced pressure and subjected to a rolling process by a roll press, resulting in a thickness of 70 μm. A positive electrode for a lithium ion secondary battery with an underlayer of Example 53 was produced.
[Examples 54 to 65, Comparative Examples 10 and 11]
Except having used the base layer shown in Table 4, it carried out similarly to the lithium ion secondary battery negative electrode 1 with a base layer, and produced the lithium ion secondary battery negative electrode with the base layer of Examples 54-65 and Comparative Examples 10 and 11. .
<Creation of counter electrode 2 for evaluation (negative electrode for lithium ion secondary battery without base layer)>
A counter electrode 2 for evaluation was prepared in the same manner as in Example 53 except that a copper foil without a base layer applied was used as a current collector.

<Coin-type lithium ion secondary battery>
The positive electrode and negative electrode shown in Tables 3 and 4 are each punched out to a diameter of 16 mm, and a separator (porous polypropylene film) inserted between them and an electrolytic solution (ethylene carbonate and diethyl carbonate are mixed at a ratio of 1: 1 (volume ratio)) A coin-type battery comprising a non-aqueous electrolyte solution in which LiPF ₆ was dissolved at a concentration of 1 M in the mixed solvent was prepared. The coin-type battery was used in a glove box substituted with argon gas, and a predetermined battery characteristic evaluation was performed after the coin-type battery was produced.
(Charge / discharge cycle characteristics)
About the obtained coin-type battery, charging / discharging measurement was performed using the charging / discharging apparatus (SM-8 by Hokuto Denko).

After performing a constant current and constant voltage charge (cutoff current 0.1 mA) at a charge end voltage of 4.0 V at a charge current of 1.0 mA (0.2 C), the discharge end voltage is 2.0 V at a discharge current of 1.0 mA. The constant current discharge was performed until it reached. These charge / discharge cycles are defined as one cycle, and 5 cycles of charge / discharge are repeated, and the discharge capacity at the fifth cycle is defined as the initial discharge capacity. (The initial discharge capacity is assumed to be 100% maintenance rate).

Next, after performing constant current and constant voltage charging (cutoff current 0.5 mA) at a charging current 5.0 mA at a charging current 5.0 mA in a 50 ° C. constant temperature bath, a discharge final voltage is discharged at a discharge current 5.0 mA. Constant current discharge was performed until 2.0V was reached. This charge / discharge cycle was repeated 200 times, and the rate of change of the discharge capacity retention rate was calculated (the closer to 100%, the better).

A: “Change rate is 90% or more. Particularly excellent.”
○: “Change rate is 85% or more and less than 90%. No problem”
○ △: “Change rate is 80% or more and less than 85%. Usable level.”
Δ: “Change rate is 75% or more and less than 80%. There is a problem but it is usable level.”
X: “Change rate is less than 75%.

<Preparation of composite ink for electric double layer capacitor electrode for evaluation>
For 100 parts of solid content of polytetrafluoroethylene 30-J (Mitsui / DuPont Fluorochemical Co., Ltd., 60% aqueous dispersion), 4300 parts of activated carbon as an active material, 250 parts of acetylene black, thickener, respectively. As a mixture, 400 parts of carboxymethylcellulose was added, ion-exchanged water was added so as to have a solid content of 50%, and kneaded to prepare a mixture ink for an electric double layer capacitor electrode.

<Creation of an electric double layer capacitor electrode with an underlayer>
[Example 66]
After applying the mixture ink for electric double layer capacitor electrodes for evaluation to the current collector with the underlayer of Example 14 using a doctor blade, it was dried under reduced pressure and subjected to a rolling process by a roll press, and the thickness was 50 μm. An electrode for an electric double layer capacitor without underlying layer of Example 66 was produced.
[Examples 67 to 91, Comparative Examples 12 to 15]
Except for using the collector with an underlayer shown in Tables 5 and 6, in the same manner as the electric double layer capacitor electrode with an underlayer of Example 66, with the underlayer of Examples 67 to 78 and Comparative Examples 12 and 13 An electric double layer capacitor electrode was prepared.
<Preparation of electrode 3 for evaluation (electric double layer capacitor electrode without base layer)>
A counter electrode for evaluation 3 was prepared in the same manner as in Example 66 except that an aluminum foil without a base layer applied was used as a current collector.

<Electric double layer capacitor>
The electrodes shown in Tables 5 and 6 were each punched out to a diameter of 16 mm, and a separator (porous polypropylene film) inserted between them and an electrolyte (propylene carbonate solvent (TEMABF ₄ (triethylmethylammonium tetrafluoride) 1M) The electric double layer capacitor was made in a glove box substituted with argon gas, and after the electric double layer capacitor was prepared, predetermined electric characteristics were evaluated. Went.
(Charge / discharge cycle characteristics)
About the obtained coin-type battery, charging / discharging measurement was performed using the charging / discharging apparatus (SM-8 by Hokuto Denko).
(Charge / discharge cycle characteristics)
About the obtained electric double layer capacitor, charging / discharging measurement was performed using the charging / discharging apparatus.

After charging to a charge end voltage of 2.0 V at a charge current of 10 C, constant current discharge was performed until the discharge end voltage of 0 V was reached at a discharge current of 10 C. These charge / discharge cycles are defined as one cycle, and 5 cycles of charge / discharge are repeated, and the discharge capacity at the fifth cycle is defined as the initial discharge capacity. (The initial discharge capacity is assumed to be 100% maintenance rate). In addition, the charge / discharge current rate was 1 C, which is the magnitude of current that can discharge the cell capacity in one hour.

Next, charging was performed at a charging current 10C rate in a 50 ° C. constant temperature bath at a charging end voltage of 2.0 V, and then constant current discharging was performed at a discharging current of 10 C rate until reaching a discharging end voltage of 0 V. This charge / discharge cycle was repeated 500 times to calculate the rate of change of the discharge capacity maintenance rate (the closer to 100%, the better).

A: “Change rate is 90% or more. Particularly excellent.”
○: “Change rate is 85% or more and less than 90%. No problem”
○ △: “Change rate is 80% or more and less than 85%. Usable level.”
Δ: “Change rate is 75% or more and less than 80%. There is a problem but it is usable level.”
X: “Change rate is less than 75%.

<Preparation of composite ink for positive electrode of lithium ion capacitor for evaluation>
4100 parts of activated carbon, 250 parts of acetylene black, and carboxymethyl cellulose 400 as a thickener for 100 parts of solid content of polytetrafluoroethylene 30-J (manufactured by Mitsui DuPont Fluorochemical Co., Ltd., 60% aqueous dispersion), respectively. Then, ion exchange water was added so that the solid content was 33%, and then kneaded to prepare a mixture ink for a positive electrode of a lithium ion capacitor.
<Preparation of composite ink for negative electrode of lithium ion capacitor for evaluation>
6000 parts of graphite, which is a negative electrode active material, 333 parts of acetylene black, and 233 parts of hydroxyethyl cellulose as a thickener are added to 100 parts of a solid content of a 40% aqueous dispersion of styrene-butadiene latex, respectively, and a solid content of 33 After adding ion-exchanged water so that it might become%, it knead | mixed and prepared the mixture ink for lithium ion capacitor negative electrodes.

<Creation of a lithium ion capacitor positive electrode with an underlayer>
[Example 92]
The lithium ion capacitor positive electrode mixture ink for evaluation was applied to the current collector with the underlayer of Example 14 using a doctor blade, then dried under reduced pressure, and subjected to a rolling process using a roll press, resulting in a thickness of 60 μm. A lithium ion capacitor positive electrode with an underlayer of Example 92 was produced.
[Examples 93 to 104, Comparative Examples 16 and 17]
Except having used the collector with a base layer shown in Table 7, the lithium ion capacitor with a base layer of Examples 93-104 and Comparative Examples 16 and 17 was carried out similarly to the positive electrode of the lithium ion capacitor with a base layer of Example 92. A positive electrode was prepared.
<Creation of counter electrode 4 for evaluation (lithium ion capacitor positive electrode without base layer)>
A counter electrode 4 for evaluation was prepared in the same manner as in Example 92 except that an aluminum foil without a base layer applied was used as a current collector.

<Creation of a lithium ion capacitor negative electrode with an underlayer>
[Example 105]
The lithium ion capacitor negative electrode mixture ink for evaluation was applied to the current collector with an underlayer of Example 27 using a doctor blade, then dried under reduced pressure, and subjected to a rolling process using a roll press, resulting in a thickness of 45 μm. A lithium ion capacitor negative electrode with an underlayer of Example 105 was produced.

[Examples 106 to 117, Comparative Examples 18 and 19]
Except using the collector with a base layer shown in Table 8, the negative electrode with a lithium ion capacitor of Examples 106-117 and Comparative Examples 18 and 19 was carried out similarly to the lithium ion capacitor negative electrode with a base layer of Example 106. It was created.
<Preparation of counter electrode 5 for evaluation (lithium ion capacitor negative electrode without base layer)>
A counter electrode for evaluation 5 was prepared in the same manner as in Example 105 except that a copper foil without a base layer applied was used as a current collector.

<Lithium ion capacitor>
A positive electrode shown in Tables 7 and 8 and a negative electrode previously half-doped with lithium ions were prepared with a diameter of 16 mm, a separator (porous polypropylene film) inserted between them, and an electrolyte (ethylene) A lithium ion capacitor comprising a non-aqueous electrolyte solution in which LiPF ₆ was dissolved at a concentration of 1 M in a mixed solvent in which carbonate, dimethyl carbonate, and diethyl carbonate were mixed at a ratio of 1: 1: 1 (volume ratio) was produced. Lithium ion half dope was performed by sandwiching a separator between the negative electrode and lithium metal in a beaker cell, and doping the negative electrode with lithium ions so that the amount was about half of the negative electrode capacity. Moreover, the lithium ion capacitor was performed in a glove box substituted with argon gas, and a predetermined electrical property evaluation was performed after the lithium ion capacitor was fabricated. (Charge / discharge cycle characteristics)
About the obtained coin-type battery, charging / discharging measurement was performed using the charging / discharging apparatus (SM-8 by Hokuto Denko).

After performing a constant current and constant voltage charge (cutoff current 0.1 mA) at a charge end voltage of 4.0 V at a charge current of 1.0 mA (0.2 C), the discharge end voltage is 2.0 V at a discharge current of 1.0 mA. The constant current discharge was performed until it reached. These charge / discharge cycles are defined as one cycle, and 5 cycles of charge / discharge are repeated, and the discharge capacity at the fifth cycle is defined as the initial discharge capacity. (The initial discharge capacity is assumed to be 100% maintenance rate).

Next, after performing constant current and constant voltage charging (cutoff current 0.5 mA) at a charging current 5.0 mA at a charging current 5.0 mA in a 50 ° C. constant temperature bath, a discharge final voltage is discharged at a discharge current 5.0 mA. Constant current discharge was performed until 2.0V was reached. This charge / discharge cycle was repeated 200 times, and the rate of change of the discharge capacity retention rate was calculated (the closer to 100%, the better).

A: “Change rate is 90% or more. Particularly excellent.”
○: “Change rate is 85% or more and less than 90%. No problem”
○ △: “Change rate is 80% or more and less than 85%. Usable level.”
Δ: “Change rate is 75% or more and less than 80%. There is a problem but it is usable level.”
X: “Change rate is less than 75%.

As shown in Table 2, adhesion to the current collector and water resistance were excellent by using the binder composition for an electricity storage device underlayer containing the resin fine particles (A) of the present invention (Examples 1 to 13). An underlayer for the electricity storage device (Examples 14 to 39) could be obtained. It is considered that the adhesion and water resistance of the underlayer can be improved by the resin fine particles having a cross-linked structure with a current collector having a hydroxyl group on the surface or a water-soluble resin.

As shown to Tables 3-8, by using the base layer (Examples 14-39) using the binder composition for electrical storage device base layers containing the resin fine particles (A) (Examples 1-13) of this invention. It turned out that the electrode plate which has the outstanding battery characteristic and the electrical storage device using the same are obtained. This is considered to be because the degradation of the electricity storage device could be suppressed because the peeling state of the underlying layer during device use was suppressed by controlling the cross-linking state in the electrode plate or the underlying layer.

As shown in Tables 3 to 8, the monomer (e) having an ethylenically unsaturated group has a single amount having one ethylenically unsaturated group and an alkyl group having 8 to 18 carbon atoms in one molecule. A monomer (g) having one ethylenically unsaturated group and a cyclic structure in the molecule (f) and / or one molecule, the monomer (f) and / or (g) Underlayers (Examples 14 to 16, 18, 20 to 22, 24 to 29, 31, 33 to 35) using a binder contained in 30 to 95% by weight in a total of 100% of the monomers (a) to (e) 37-39), a binder containing 0 to 30% by weight of the monomer (f) and / or (g) in a total of 100% of the monomers (a) to (e). Electrode plate having excellent battery characteristics as compared with the underlayer used (Examples 17, 19, 30, 32), and using the same It was found that the electric storage device is obtained. This is thought to be because the deterioration of the electricity storage device could be suppressed because the peeling of the underlayer when using the device was further suppressed and the anti-electrolytic solution property of the underlayer when using the electricity storage device was improved.

As shown in Table 2, the foundation layer (Examples 14-17, 19-21, 23, 25, 27-30, 32-34, 36) using the water-soluble resin (B) having a hydroxyl value of 10-1275. 38), the base layer using the water-soluble resin (B) having a hydroxyl value of 0 to 10 (Examples 18, 22, 24, 31, 35, 37) has excellent water resistance and adhesion. It turns out that it is obtained. This is presumably because the resin fine particles (A) and the hydroxyl group-containing water-soluble resin (B) have a crosslinked structure, thereby improving the water resistance as the binder composition and the adhesion to the current collector.

As shown in Tables 1-8, the foundation layer (Examples 14-16, 18, 20-22, 24-29, 31, 33-35, 37- using the resin fine particles whose Tg is -10-30 degreeC. 39) can provide an electrode plate having excellent battery characteristics as compared with the underlayer (Examples 23 and 36) using resin fine particles having a Tg of −40 ° C., and an electricity storage device using the electrode plate. I understood. This is presumably because the resin fine particles are difficult to cover the conductive carbon material and have excellent conductivity.

As shown in Tables 1-2, the ground layer (Examples 14-17, 19-21, 23, 25, 27-30, 32-34, 36, using the resin fine particle whose Tg is -10-30 degreeC. It was found that No. 38) exhibited excellent adhesion as compared with the underlayer (Examples 26 and 39) using resin fine particles having a Tg of 80 ° C. This is considered because the resin fine particles are excellent in flexibility and adhesiveness.

As shown in Tables 1-8, the underlayers (Examples 16, 20-22, 29, 33-35) using resin fine particles obtained by copolymerizing the monomer (c) are monomer ( c) an electrode plate having excellent battery characteristics as compared with the underlayer (Examples 14, 15, 18, 24 to 28, 31, 37 to 39) using resin fine particles not copolymerized with c), and It was found that the power storage device used was obtained. In addition, the base layer (Examples 16 and 29) using resin fine particles in which the monomer (c) and the monomer (a) are used in combination uses resin fine particles in which the monomer (a) is not used in combination. It turned out that the electrode plate which has the further superior battery characteristic compared with a base layer (Examples 20-22, 33-35), and an electrical storage device using the same are obtained.

Claims (8)

Monomer (c) having one ethylenically unsaturated group and monofunctional or polyfunctional blocked isocyanate group in one molecule, 0.1 to 20% by weight, ethylenically unsaturated group other than the monomer Monomer (e) containing 80 to 99.9% by weight of a monomer having an ethylenically unsaturated group in water in the presence of a surfactant and emulsion polymerization with a radical polymerization initiator Resin fine particles for underlayer (A) (provided that monomer (e) is a monomer (a) having one ethylenically unsaturated group and a monofunctional or polyfunctional alkoxysilyl group in one molecule, Monomer (b) having one ethylenically unsaturated group and monofunctional or polyfunctional isocyanate group in one molecule, and one ethylenically unsaturated group in one molecule and monofunctional or polyfunctional alkyl Monomer (d) having a roll amide group Is not included) . Monomer (a) having one ethylenically unsaturated group in one molecule and a monofunctional or polyfunctional alkoxysilyl group, one ethylenically unsaturated group in one molecule, and a monofunctional or polyfunctional block 0.1 to 20% by weight of the monomer (c) having an isocyanate group and 80 to 99.9% by weight of the monomer (e) having an ethylenically unsaturated group other than the monomer Resin fine particles for an electricity storage device underlayer (A) obtained by emulsion polymerization of a monomer having an ethylenically unsaturated group in water with a radical polymerization initiator in the presence of a surfactant (provided that the monomer (e) Are monomers (b) having one ethylenically unsaturated group and monofunctional or polyfunctional isocyanate group in one molecule, and one ethylenically unsaturated group in one molecule and monofunctional or polyfunctional Monomers having a functional alkylolamide group ( d) is not included) . The monomer (e) having an ethylenically unsaturated group is a monomer (f) having one ethylenically unsaturated group and an alkyl group having 8 to 18 carbon atoms in one molecule and / or one molecule. A monomer (g) having one ethylenically unsaturated group and a cyclic structure, and the monomer (f) and / or (g) is contained in a total of 100% of all monomers. The resin fine particles (A) for an electricity storage device underlayer according to claim 1 or 2, wherein the resin fine particles (A) are contained in an amount of 30 to 95 wt%. 4. An electricity storage device underlayer formation comprising the electricity storage device underlayer resin fine particles (A) according to any one of claims 1 to 3, a water-soluble resin (B), and a conductive carbon material (C). Ink. The water-soluble resin (B) has a hydroxyl value of 10 to 1275 mgKOH / g, and the ink for forming an electricity storage device base layer according to claim 4. A current collector with a base layer for a power storage device, comprising: a current collector; and a base layer formed from the power storage device base layer forming ink according to claim 5. The electrode for electrical storage devices which consists of a collector with a base layer for electrical storage devices of Claim 6, and an electrode plate layer. The electrical storage device which comprises a positive electrode, a negative electrode, and electrolyte solution, Comprising: At least one of the said positive electrode or the said negative electrode is an electrode for electrical storage devices of Claim 7.