TW202343876A - Binder dispersion for non-aqueous secondary battery separators, slurry composition, non-aqueous secondary battery separator, and non-aqueous secondary battery - Google Patents

Abstract

To provide a binder dispersion improved in electrolyte resistance, a slurry composition improved in solution stability and coating property, a separator improved in heat resistance and adhesiveness to a separator substrate, and a non-aqueous secondary battery which reduces internal resistance and is improved in cycle characteristics. The present invention relates to a binder dispersion for non-aqueous secondary battery separator containing a polymer (A1) and an aqueous medium. The polymer (A1) is a polymer of an ethylenic unsaturated monomer mixture of which the acid value is equal to or less than 15 mgKOH/g and, with a total mass of the ethylenic unsaturated monomer mixture defined as a reference, which contains (meth)acrylamide in 50-85 mass% and non-ionic ethylenic unsaturated monomers (a-1) in 15-50 mass% of which a logarithm of an octanol/water distribution coefficient (Log Kow) at 25 DEG C is 1.9-4.2. Light transmittance in a wavelength of 400 nm under a condition that a solid content density is 5 mass% is less than 70%.

Description

Binder dispersion liquid, slurry composition for non-aqueous secondary battery separators, non-aqueous secondary battery separators, and non-aqueous secondary batteries

The present invention relates to an adhesive for non-aqueous secondary battery separators that can be used to form a protective layer for separators of non-aqueous secondary batteries such as lithium ion secondary batteries. In addition, the present invention relates to a coating agent containing the adhesive for non-aqueous secondary battery separators, and a non-aqueous secondary battery having a protective layer formed from the coating agent containing the adhesive for non-aqueous secondary battery separators. A battery separator, and a non-aqueous secondary battery provided with the non-aqueous secondary battery separator.

Non-aqueous secondary batteries are used in a wide range of applications because they are small and lightweight, have high energy density, and can be repeatedly charged and discharged. Among them, lithium-ion secondary batteries are used in a wide range of applications such as smartphones, tablets, notebook computers, and electric vehicles because they can obtain high output, and the demand for these lithium-ion secondary batteries is rapidly expanding.

For lithium-ion secondary batteries, in order to ensure safety during abnormal conditions, an electrically insulating separator layer is provided between electrodes. The separator has a porous structure that allows lithium ions to circulate normally. However, an abnormal reaction occurs and the pores close at high temperatures, blocking the flow of lithium ions, thereby preventing short circuits in the battery. As such a separator, a polyolefin sheet such as polyethylene or polypropylene having a porous structure or a coating-type sheet using these base materials as a base and provided with a protective layer to impart heat resistance is used. For this purpose, a slurry composition containing non-conductive particles and a binder is applied and formed. In recent years, as the capacity of batteries has been further increased, separators are expected to be thinner. In the above-mentioned coating type separators, thinning of the base material is also being promoted.

On the other hand, if the base material is made thinner, the heat resistance or durability of the separator is likely to further decrease. Therefore, in recent years, studies have been conducted on imparting excellent heat resistance or durability to such partitions. Patent Document 1 discloses a protective layer using a water-soluble polymer obtained by polymerizing a (meth)acrylamide group-containing compound and a hydroxyl-containing (meth)acrylate as a separator adhesive. Patent Document 2 discloses a protective layer using a water-soluble polymer and a particulate polymer containing 40% by mass or more of (meth)acrylamide as a separator adhesive. Patent Document 3 discloses a protective layer using a polymer of a amide group-containing ethylenically unsaturated monomer, a carboxyl group-containing ethylenically unsaturated monomer, and a carboxylic acid ester-containing ethylenically unsaturated monomer. Adhesive for dividers. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2020-24896. [Patent Document 2] International Publication No. 2017/026095. [Patent Document 3] International Publication No. 2019/065909.

[Problem to be solved by the invention]

In the case of adhesives for separators such as those using water-soluble resins, they have excellent heat resistance and electrolyte resistance, but there is a risk of poor coating properties due to high viscosity, or when mixed with inorganic particles. When the slurry composition for non-aqueous secondary battery separators is produced, there is a risk that the internal resistance will be increased because the gaps between the inorganic particles are filled. In addition, the separator has a high moisture content, which may lead to reduced cycle characteristics due to reaction between battery components and moisture.

Therefore, an object of the present invention is to provide a non-aqueous secondary battery separator adhesive dispersion excellent in electrolyte resistance, and a non-aqueous secondary battery separator-containing adhesive dispersion excellent in solution stability and coating properties. A slurry composition for aqueous secondary battery separators and a protective layer provided with a slurry composition for non-aqueous secondary battery separators, which has a low moisture content and is excellent in heat resistance and adhesion to a separator base material. A non-aqueous secondary battery separator, and a non-aqueous secondary battery having the non-aqueous secondary battery separator with small internal resistance and good cycle characteristics. [Means used to solve problems]

That is, the present invention relates to a binder dispersion for non-aqueous secondary battery separators, which contains polymer (A1), a surfactant, and an aqueous medium, and the polymer (A1) has an acid value of 15 mgKOH/g or less and The total mass of the ethylenically unsaturated monomer mixture contains 50 mass % to 85 mass % of (meth)acrylamide, and the logarithm (Log Kow) of the octanol/water partition coefficient at 25° C. is 1.9 to 4.2. A polymer of an ethylenically unsaturated monomer mixture of 15% to 50% by mass of the nonionic ethylenically unsaturated monomer (a-1), which reacts to light with a wavelength of 400 nm at a solid content concentration of 5% by mass. The penetration rate is less than 70%.

In addition, the present invention relates to the aforementioned adhesive dispersion for separators of non-aqueous secondary batteries, wherein the storage elastic modulus of the polymer (A1) at 150°C is 1.0×10 ⁶ Pa or more.

In addition, the present invention relates to the aforementioned adhesive dispersion for separators of non-aqueous secondary batteries, in which the polymer (A1) is dissolved in a mixed solvent of ethylene carbonate and diethyl carbonate at a volume ratio of 2:3 at 60°C. The swelling degree of the electrolyte at the time of immersion for 72 hours did not reach 2 times.

In addition, the present invention relates to the aforementioned adhesive dispersion for non-aqueous secondary battery separators, wherein the viscosity at a solid content concentration of 15% by mass is 100 mPa·s or more and less than 15,000 mPa·s.

In addition, the present invention relates to a slurry composition for non-aqueous secondary battery separators, which contains inorganic fine particles and the aforementioned adhesive dispersion for non-aqueous secondary battery separators.

In addition, the present invention relates to the aforementioned slurry composition for non-aqueous secondary battery separators, which further contains polymer (A2) (excluding polymer (A1)), and the polymer (A2) has a glass transition temperature of - Particulate polymer at 40℃ to 40℃.

In addition, the present invention relates to a non-aqueous secondary battery separator, which is formed by providing a protective layer on at least one side of the separator base material, and the protective layer is made of the aforementioned slurry composition for non-aqueous secondary battery separators. formed.

In addition, the present invention relates to a non-aqueous secondary battery including the non-aqueous secondary battery separator.

Hereinafter, the adhesive dispersion liquid for non-aqueous secondary battery separators, the slurry composition for non-aqueous secondary battery separators, the non-aqueous secondary battery separator, and the non-aqueous secondary battery separator of the present invention will be described based on appropriate embodiments. Secondary battery. However, the present invention is not limited to this. Each component may be replaced by any component capable of performing the same function, or any component may be added. In addition, in this specification, the numerical range specified using "to" includes the range of the numerical values written before and after "to" as the lower limit and upper limit. In addition, in this specification, "film" or "sheet" is not distinguished based on thickness. In addition, in this specification, when it is expressed as "(meth)acrylamide" or "(meth)acrylate", unless otherwise specified, it means "acrylamide or methacrylamide" respectively. ”, “acrylate or methacrylate”. In addition, the so-called ethylenically unsaturated monomer means a monomer having an ethylenically unsaturated double bond. The ethylenically unsaturated monomer is classified into (meth)acrylamide and has an octanol/water partition coefficient at 25°C. Nonionic ethylenically unsaturated monomer (a-1) with a log Kow of 1.9 to 4.2, and other ethylenically unsaturated monomers polymerizable with the nonionic ethylenically unsaturated monomer (a-1) Body(a-2). In addition, in this specification, the logarithm of the octanol/water partition coefficient (Log Kow) at 25°C is sometimes referred to as the nonionic ethylenically unsaturated monomer (a-1) and the non-aqueous secondary The adhesive dispersion for battery separators and the slurry composition for non-aqueous secondary battery separators are abbreviated as nonionic ethylenically unsaturated monomer (a-1), adhesive dispersion, and slurry composition respectively. In addition, unless otherwise noted, various components appearing in this specification may be independently one type or two or more types may be used in combination.

Furthermore, the so-called non-aqueous secondary battery refers to a secondary battery that does not use water in the electrolyte. Examples include: lithium ion secondary battery (LIB; Lithium Ion Battery), sodium ion secondary battery, magnesium secondary battery Batteries etc. In this specification, LIB is explained as an example of a non-aqueous secondary battery, but it goes without saying that the adhesive dispersion for non-aqueous secondary battery separators and non-aqueous secondary batteries of the present invention can be applied to non-aqueous secondary batteries other than LIB. Slurry composition for secondary battery separators, non-aqueous secondary battery separators.

[Binder dispersion for non-aqueous secondary battery separators] The adhesive dispersion for non-aqueous secondary battery separators contains polymer (A1), surfactant, and aqueous medium, and has a light transmittance of less than 70% at a wavelength of 400 nm at a solid content concentration of 5% by mass. . Furthermore, the polymer (A1) has an acid value of 15 mgKOH/g or less, and contains 50 to 85 mass% of (meth)acrylamide based on the total mass of ethylenically unsaturated monomers, and octane at 25°C. A polymer of an ethylenically unsaturated monomer mixture of 15 to 50 mass % of nonionic ethylenically unsaturated monomer (a-1) having a logarithm of alcohol/water partition coefficient (Log Kow) of 1.9 to 4.2. In this way, a binder dispersion for non-aqueous secondary battery separators with excellent electrolyte resistance can be produced. The solution stability and coating properties of the slurry composition using the aforementioned binder dispersion for non-aqueous secondary battery separators are excellent. Excellent application properties.

[Aqueous medium] Here, the so-called aqueous medium refers to an aqueous dispersion medium or an aqueous solvent. As the aqueous medium, water is preferably used, and a water-soluble solvent may also be used if necessary. Examples of water-soluble solvents include: alcohols, glycols, cellosols, aminoalcohols, amines, ketones, carboxylic acid amides, phosphoric acid amides, and triacetes esters, carboxylates, phosphates, ethers, nitriles, etc.

[Surfactant] Examples of the surfactant include anionic surfactants, cationic surfactants, and nonionic surfactants, and an anionic surfactant or a nonionic surfactant is preferred. By including the surfactant, the polymer (A1) can be stably dispersed in the aqueous medium, and the slurry composition using the surfactant can have excellent solution stability. The surfactant content is preferably 0.05 to 2.0 parts by mass, more preferably 0.05 to 0.5 parts by mass based on 100 parts by mass of the polymer (A1), so that the polymerization of the polymer (A1) in the aqueous medium is stabilized. sex further improved.

Examples of the anionic surfactant include higher fatty acid salts such as sodium oleate, alkyl aryl sulfonates such as dodecyl benzene sulfonic acid, alkyl sulfate ester salts such as sodium lauryl sulfate, and polyoxyethylene. Polyoxyethylene alkyl ether sulfate ester salts such as sodium lauryl ether sulfate, sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, polyoxyethylene sodium lauryl sulfosuccinate and other alkyl sulfosuccinic acids Ester salts and their derivatives, polyoxyethylene distyrenated phenyl ether sulfate ester salts, etc. are less likely to have adverse effects on the food resistance (seasoning resistance, microwave resistance) of food packaging sheets. Among the above, the surfactant is preferably an alkyl sulfate ester salt or an alkyl sulfosuccinate salt, more preferably the alkyl sulfate ester salt is lauryl sulfate, and the alkyl sulfosuccinate salt is more preferably a dimethyl sulfate. Octyl sulfosuccinate.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether; polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether; Oxyethylene alkyl phenyl ether; sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate and other sorbitan higher fatty acid esters; polyoxyethylene sorbitan monolaurate , polyoxyethylene sorbitan monostearate and other polyoxyethylene sorbitan higher fatty acid esters; polyoxyethylene monolaurate, polyoxyethylene monostearate and other polyoxyethylene higher fatty acid esters; oil Glycerin higher fatty acid esters such as acid monoglyceride and stearic acid monoglyceride; polyoxyethylene-polyoxypropylene-block copolymer, polyvinyl alcohol, polyvinylpyrrolidone, polyoxyethylene distyrenated phenyl ether, etc. .

In addition, a polymerizable surfactant having one or more radically polymerizable unsaturated double bonds (vinyl group, (meth)acrylyl group) in the molecule can also be used as the surfactant.

Examples of polymerizable anionic surfactants include those whose main skeleton is sulfosuccinate, alkyl ether, alkyl phenyl ether, alkyl phenyl ester, (meth)acrylate sulfate, and phosphate ester. . Examples of polymerizable nonionic surfactants include those whose main skeleton is alkyl ether, alkyl phenyl ether, alkyl phenyl ester, etc.

[Polymer(A1)] The polymer (A1) has an acid value of 15 mgKOH/g or less, contains at least (meth)acrylamide, and has a nonionic octanol/water partition coefficient (Log Kow) of 1.9 to 4.2 at 25°C. A polymer of an ethylenically unsaturated monomer mixture of ethylenically unsaturated monomer (a-1), and the ethylenically unsaturated monomer mixture may also contain other ethylenically unsaturated monomers (a-2) if necessary. In addition, the ethylenically unsaturated monomer mixture contains 50 to 85 mass% of (meth)acrylamide and 15 mass% of the ethylenically unsaturated monomer (a-1) based on the total mass (100 mass%). to 50% by mass.

Furthermore, in this specification, even if the glass transition temperature (Tg) is -40°C to 40°C, a polymer that satisfies the above requirements is defined as polymer (A1).

The acid value of the polymer (A1) is 15 mgKOH/g or less, more preferably 10 mgKOH/g or less. By being in the above range, when blending with inorganic fine particles to prepare a slurry composition for non-aqueous secondary battery separators, the solution stability of the slurry composition becomes better.

[(Meth)acrylamide] (Meth)acrylamide contains 50 mass % to 85 mass % based on the total mass of ethylenically unsaturated monomers (100 mass %), and more preferably 60 mass % to 80 mass %. By containing (meth)acrylamide in the above range, electrolyte resistance and heat resistance can be significantly improved. In addition, when mixed with inorganic fine particles to prepare a slurry composition for non-aqueous secondary battery separators, the affinity with the inorganic fine particles is improved, thereby improving the solution stability of the slurry composition.

[Nonionic ethylenically unsaturated monomer (a-1)] The nonionic ethylenically unsaturated monomer (a-1) is an ethylenically unsaturated monomer with a log Kow of octanol/water partition coefficient of 1.9 to 4.2, preferably 2.0 to 4.2, more preferably 2.2 to 3.5. Single body. When the Log Kow is 1.9 or more, the polymer (A1) becomes a dispersion system in the aqueous medium, and when the slurry composition is prepared, the gaps between the inorganic particles will not be filled and the ion penetrability of the separator will be reduced. good. This improves battery performance such as internal resistance and cycle characteristics. In addition, when the adhesive is polymerized in order to achieve good heat resistance and adhesion of the separator, high viscosity is suppressed, and the coating properties of the slurry composition are also excellent. In addition, the moisture content of the separator is reduced and the cycle characteristics are excellent. Furthermore, when Log Kow is 4.2 or less, the nonionic ethylenically unsaturated monomer (a-1) is incorporated more uniformly, resulting in excellent adhesion and heat resistance.

Furthermore, the so-called nonionic ethylenically unsaturated monomer refers to an ethylenically unsaturated monomer that does not have a charged functional group when it is in an aqueous medium, such as one that does not have an amine group, a carboxyl group, a sulfo group, etc. Ethylenically unsaturated monomer.

Moreover, it is preferable that the nonionic ethylenically unsaturated monomer (a-1) does not have a crosslinkable functional group, that is, it is preferably a monomer that does not have a crosslinkable functional group. The crosslinkable functional group refers to a functional group that imparts a crosslinked structure to the side chain of the polymer, and examples thereof include a glycidyl group, an alkoxysilyl group, an ethylenically unsaturated group, and the like. Examples of the monomer having a crosslinkable functional group include a monomer having a glycidyl group, a monomer having an alkoxysilyl group, and a monomer having two or more ethylenically unsaturated bond groups.

The content rate of the nonionic ethylenically unsaturated monomer (a-1) is 15 mass % to 50 mass % based on the total mass of the ethylenically unsaturated monomer (100 mass %), and more preferably 20 mass % to 40 mass %. Mass %. When the ethylenically unsaturated monomer content is 15% by mass or more, the amount of moisture in the separator can be reduced, resulting in excellent cycle characteristics. In addition, the increase in viscosity is suppressed, and the slurry composition has excellent coating properties. Furthermore, when the ethylenically unsaturated monomer content is 50% by mass or less, it is possible to achieve both the adhesion and heat resistance of the separator.

Examples of the nonionic ethylenically unsaturated monomer (a-1) having a logarithm of the octanol/water partition coefficient (Log Kow) of 1.9 to 4.2 include: tert-butyl acrylate (Log Kow = 2.06), Isobutyl acrylate (Log Kow=2.09), butyl acrylate (Log Kow=2.23), propyl methacrylate (Log Kow=2.28), tert-butyl methacrylate (Log Kow=2.67), amyl acrylate (Log Kow=2.70), butyl methacrylate (Log Kow=2.84), amyl methacrylate (Log Kow=3.03), hexyl acrylate (Log Kow=3.11), hexyl methacrylate (Log Kow= 3.50), heptyl acrylate (Log Kow=3.62), 2-ethylhexyl acrylate (Log Kow=4.01), heptyl methacrylate (Log Kow=4.01), octyl acrylate (Log Kow=4.20), etc. Ethylenically unsaturated monomers containing linear or branched alkyl groups; phenyl acrylate (Log Kow=1.97), benzyl acrylate (Log Kow=2.32), phenoxyethyl acrylate (Log Kow=2.44), benzene Oxydiethylene glycol acrylate (Log Kow=2.44), phenyl methacrylate (Log Kow=2.57), styrene (Log Kow=2.71), benzyl methacrylate (Log Kow=2.91), methyl Phenoxyethyl acrylate (Log Kow=3.02), Phenoxydiethylene glycol methacrylate (Log Kow=3.02), Phenoxytetraethylene glycol acrylate (Log Kow=3.38), o-Methyl Styrene (Log Kow=3.40), α-methylstyrene (Log Kow=3.46), m-methylstyrene (Log Kow=3.46), p-methylstyrene (Log Kow=3.61), phenoxytetrakis Aromatic ethylenically unsaturated monomers such as ethylene glycol methacrylate (Log Kow=3.96), phenoxyhexaethylene glycol acrylate (Log Kow=4.15); dicyclopentenoxyethyl acrylate ( Log Kow=2.57), cyclohexyl acrylate (Log Kow=2.62), dicyclopentenyl acrylate (Log Kow=2.98), cyclohexyl methacrylate (Log Kow=3.06), dicyclopentyl acrylate (Log Kow=3.29), dicyclopentenyl methacrylate (Log Kow=3.41), dicyclopentyl methacrylate (Log Kow=3.73), isobornyl acrylate (Log Kow=3.78), isobornyl methacrylate Ethylene unsaturated monomers containing cycloalkyl groups such as esters (Log Kow=4.20); ethylenically unsaturated monomers containing hydroxyl groups such as 4-hydroxyvinylbenzene (Log Kow=2.28); N-pentoxymethyl -Acrylamide (Log Kow=1.90), N,N-bis(propoxymethyl)acrylamide (Log Kow=1.90), N-pentyloxymethyl-methacrylamide (Log Kow= 2.29), N,N-bis(propoxymethyl)methacrylamide (Log Kow=2.29), N,N-bis(butoxymethyl)acrylamide) (Log Kow=3.12), N,N-di(butoxymethyl)methacrylamide (Log Kow=3.51) and other ethylenically unsaturated monomers containing amide groups; 2-butenyl acrylate (Log Kow=1.91), 1-Butenyl acrylate (Log Kow=1.94), Ethylene glycol dimethacrylate (Log Kow=2.07), Allyl methacrylate (Log Kow=2.10), 2-Methyl acrylate Ester (Log Kow=2.10), divinyl adipate (Log Kow=2.12), 1,4-butanediol diacrylate (Log Kow=2.12), diallyl itaconate (Log Kow=2.19 ), 1-methallyl methacrylate (Log Kow=2.50), diallyl isophthalate (Log Kow=2.51), 3-butenyl methacrylate (Log Kow=2.53) , 2-butenyl methacrylate (Log Kow=2.60), 1,3-methyl-3-butenyl acrylate (Log Kow=2.62), 1-butenyl methacrylate (Log Kow =2.63), 2-methylallyl methacrylate (Log Kow = 2.71), 1,4-butanediol dimethacrylate (Log Kow = 2.98), diallyl phthalate (Log Kow = 2.98) Ethylene with more than 2 ethylenically unsaturated groups, such as Log Kow=3.00), 1,3-methyl-3-butenyl methacrylate (Log Kow=3.01), divinylbenzene (Log Kow=3.93), etc. Sexually unsaturated monomer; γ-methacryloxymethyltrimethoxysilane (Log Kow=1.90), γ-methacryloxypropyltrimethoxysilane (Log Kow=2.42), γ- Acryloxypropylmethyldimethoxysilane (Log Kow=2.47), γ-methacryloxypropylmethyldimethoxysilane (Log Kow=2.82), vinyltriethoxy Silane (Log Kow=3.12), γ-acryloxypropyltrimethoxysilane (Log Kow=3.50), γ-acryloxypropyltriethoxysilane (Log Kow=3.50), γ-methyl γ-methacryloxypropylmethyldiethoxysilane (Log Kow=3.76), γ-methacryloxypropyltriethoxysilane (Log Kow=3.86) and other alkoxysilyl-containing Ethylenically unsaturated monomer. Among them, in terms of good polymerization stability with (meth)acrylamide in an aqueous medium and good dispersibility of the polymer (A), an ethylenically unsaturated one containing a linear or branched alkyl group is preferred. The monomer or aromatic ethylenically unsaturated monomer is preferably butyl (meth)acrylate or styrene.

The octanol/water partition coefficient (Log Kow) is represented by the following (Formula 1) and is used as an index to indicate whether a certain compound X is easily distributed into the water phase or the oil phase (octanol). The Log Kow of each ethylenically unsaturated monomer can be calculated through experiments such as the flask shaking method or HPLC (High Performance Liquid Chromatography) method, or the YMB method (physical property estimation) of the Hansen melting parameter software HSPiP Function), etc. are calculated based on the simulation of the chemical structure. (Formula 1) Log Kow=Log (concentration of compound X in the octanol phase/concentration of compound X in the aqueous phase)

[Other ethylenically unsaturated monomer (a-2)] Other ethylenically unsaturated monomers (a-2) are ethylenically unsaturated monomers other than (meth)acrylamide and nonionic ethylenically unsaturated monomer (a-1), and can be combined with (meth)acrylamide Ethylenically unsaturated monomer polymerized with acrylamide and nonionic ethylenically unsaturated monomer (a-1). Examples of the ethylenically unsaturated monomer (a-2) include aromatic ethylenically unsaturated monomers such as vinyl naphthalene and phenoxyhexaethylene glycol methacrylate; ethyl (meth)acrylate; Ester, propyl acrylate, 2-ethylhexyl methacrylate, octyl methacrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, Lauryl (meth)acrylate, tridecyl (meth)acrylate, myristyl (meth)acrylate, pentadecyl (meth)acrylate, cetyl (meth)acrylate Ester, (meth)acrylic acid heptadecyl ester, (meth)acrylic acid stearate, (meth)acrylic acid isostearate, (meth)acrylic acid resin, etc. contain linear or branched alkanes Ethylenically unsaturated monomers containing fluorinated alkyl groups; trifluoroethyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate and other ethylenically unsaturated monomers containing fluorinated alkyl groups; maleic acid (anhydride) ), fumaric acid, itaconic acid, citraconic acid, or alkyl or alkenyl monoesters of these acids, β-(meth)acryloyloxyethyl succinate, (meth)acrylic acid , crotonic acid, cinnamic acid and other carboxyl-containing ethylenically unsaturated monomers; 2-acrylamide-2-methylpropanesulfonic acid, methylallylsulfonic acid, allylsulfonic acid, vinylsulfonic acid and other sulfo-containing ethylenically unsaturated monomers and their salts; N-methoxymethyl-(meth)acrylamide, N-ethoxymethyl-(meth)acrylamide, N-propyl Oxymethyl-(meth)acrylamide, N-butoxymethyl-(meth)acrylamide, N,N-di(methoxymethyl)(meth)acrylamide, N -Ethoxymethyl-N-methoxymethyl(meth)acrylamide, N,N-bis(ethoxymethyl)(meth)acrylamide, N,N-dimethyl( Meth)acrylamide, N,N-diethyl(meth)acrylamide, diacetone(meth)acrylamide and other ethylenically unsaturated monomers containing amide groups; (meth)acrylic acid- 2-hydroxyethyl ester, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycerol mono(meth)acrylate, allyl alcohol and other hydroxyl-containing ethylenically unsaturated Monomer; ethoxypolyethylene glycol (meth)acrylate, polyethylene glycol (meth)acrylate and other ethylenically unsaturated monomers containing polyoxyethylidene; (meth)acrylic acid dimethyl Aminoethyl ester, diethylaminoethyl (meth)acrylate, methylethylaminoethyl (meth)acrylate, dimethylaminostyrene, diethylaminostyrene, etc.; and Examples include: (meth)acrylic acid dimethylaminoethyl, (meth)acrylic acid diethylaminoethyl, (meth)acrylic acid methylethylaminoethyl, (meth)acrylic acid tetrakis Methylpiperidinyl ester, pentamethylpiperidinyl methacrylate, N,N-dimethylaminopropyl(meth)acrylamide, N,N-diethylaminopropyl(methyl) Amino group-containing ethylenically unsaturated monomers such as acrylamide; (meth)acrylic acid glycidyl ester, (meth)acrylic acid-3,4-epoxycyclohexylmethyl ester and other epoxy group-containing ethylenically unsaturated monomers Monomers; ethylenically unsaturated monomers containing ketone groups such as acetyl acetyloxy (meth)acrylate; allyl acrylate, 1-methylallyl acrylate, diallyl phthalate , 3-butenyl acrylate, ethylene glycol diacrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate Acrylates, pentaerythritol tri(meth)acrylate, diallyl maleate and other ethylenically unsaturated monomers with more than 2 ethylenically unsaturated groups; γ-methacryloxypropyl triacrylate Butoxysilane, γ-acryloxymethyltrimethoxysilane, vinyltrimethoxysilane, vinyltributoxysilane, vinylmethyldimethoxysilane and other alkoxysilane-containing Ethylenically unsaturated monomer; N-hydroxymethyl(meth)acrylamide, N,N-dimethylol(meth)acrylamide, alkyl etherified N-hydroxymethyl(meth)propylene Ethylenically unsaturated monomers containing hydroxymethyl groups such as amide.

As other ethylenically unsaturated monomer (a-2), the polymerization stability of (meth)acrylamide and the nonionic ethylenically unsaturated monomer (a-1) in an aqueous medium, and the slurry In the case of a material composition, methyl (meth)acrylate, hydroxyethyl (meth)acrylate, or (meth)acrylic acid is preferred in terms of good affinity with inorganic fine particles. When other ethylenically unsaturated monomer (a-2) is used in combination, the content rate of other ethylenically unsaturated monomer (a-2) is determined by It is preferable that it is 5 mass % or less based on the total body mass (100 mass %).

[Production method of polymer (A1)] As a polymerization method of the ethylenically unsaturated monomer used to produce the polymer (A1), any method such as solution polymerization, suspension polymerization, block polymerization, and emulsion polymerization can be used. The surfactant is preferably used together with the ethylenically unsaturated monomer mixture when polymerizing the polymer (A1). By using it during polymerization, the polymerization stability of (meth)acrylamide and the nonionic ethylenically unsaturated monomer (a-1) in an aqueous medium is excellent. The solid content concentration of the polymer (A1) in the adhesive dispersion is not particularly limited, but is preferably 7% by mass to 50% by mass.

As the radical polymerization initiator used in the polymerization reaction, a known oil-soluble polymerization initiator or a water-soluble polymerization initiator can be used. The radical polymerization initiator is preferably 0.1 to 1.0 parts by mass, and more preferably 0.1 to 0.5 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer mixture. By being in the above range, the viscosity of the adhesive dispersion can be adjusted to be within an appropriate range, resulting in excellent heat resistance, adhesion and coating properties.

The oil-soluble polymerization initiator is not particularly limited, and examples thereof include: benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl hydroperoxide, (2-ethylhexanoic acid) tert-butyl peroxide), tert-butyl peroxy-3,5,5-trimethylhexanoate, di-tert-butyl peroxide and other organic peroxides; 2,2'-azobisisobutyronitrile, 2,2'-Azobis-2,4-dimethylvaleronitrile, 2,2'-Azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1'- Azobis compounds such as azobis-cyclohexane-1-carbonitrile, etc.

In polymerization, it is preferred to use a water-soluble polymerization initiator. As a water-soluble polymerization initiator, for example, ammonium persulfate (APS), potassium persulfate (KPS), hydrogen peroxide, 2,2' - Previously known compounds such as azobis(2-methylpropionamidine) dihydrochloride.

During polymerization, a reducing agent may be used together with the polymerization initiator. By using a reducing agent in combination, the emulsion polymerization speed is accelerated and polymerization at low temperatures becomes easier. Examples of the reducing agent include reducing organic compounds such as ascorbic acid, erythorbic acid, tartaric acid, citric acid, glucose, formaldehyde sulfoxylate and other metal salts; sodium thiosulfate, sodium sulfite, sodium bisulfite, and metabisulfite. Sodium and other reducing inorganic compounds; ferrous chloride, carnitol powder, thiourea dioxide. These reducing agents are preferably used in an amount of 0.05 to 4 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer.

When polymerizing ethylenically unsaturated monomers, buffers, chain transfer agents, basic compounds, etc. may be used as necessary. Examples of the buffer include sodium acetate, sodium citrate, and sodium bicarbonate. Examples of the chain transfer agent include n-octyl mercaptan, tertiary octyl mercaptan, n-nonyl mercaptan, tertiary nonyl mercaptan, n-decyl mercaptan, tertiary decyl mercaptan, and n-octyl mercaptan. Undecyl mercaptan, tertiary undecyl mercaptan, n-dodecyl mercaptan, tertiary dodecyl mercaptan, n-tridecyl mercaptan, tertiary tridecyl mercaptan Thiols, n-tetradecyl mercaptan, tertiary tetradecyl mercaptan, n-heptadecyl mercaptan, tertiary heptadecyl mercaptan, tertiary hexadecyl mercaptan, n- Cetylmercaptan, etc. Basic compounds are compounds used for neutralization. Examples of the basic compound include alkylamines such as trimethylamine, triethylamine, and butylamine; 2-dimethylaminoethanol, 2-diethylaminoethanol, diethanolamine, triethanolamine, and amines; Methyl propanol and other alcohol amines; morpholine, ammonia, etc.

[optional ingredients] The adhesive dispersion of the present invention may also contain various additives such as defoaming agents, leveling agents, preservatives, solvents, cross-linking agents, dispersants, adhesives, etc. within the scope that does not hinder the effects of the present invention. Any other ingredients.

The storage elastic modulus of the polymer (A1) at 150°C is preferably 1.0×10 ⁶ Pa or more and less than 1.0×10 ¹⁰ Pa, more preferably 1.0×10 ⁷ Pa or more. By having the storage elastic modulus at 150° C. within the above range, the separator using the polymer (A1) has excellent heat resistance, and the shrinkage of the separator in the high-temperature region is suppressed, thereby preventing short circuit of the non-aqueous secondary battery. , so it is better.

When the polymer (A1) is immersed in a mixed solvent with a volume ratio of ethylene carbonate and diethyl carbonate of 2:3 at 60°C for 72 hours, the swelling degree of the electrolyte is preferably less than 2 times, and more preferably Less than 1.5 times. When the swelling degree of the electrolyte solution is less than 2 times, the conductivity of lithium ions will not be hindered by swelling of the binder, and an increase in internal resistance can be prevented, which is preferable.

The adhesive dispersion for non-aqueous secondary battery separators of the present invention has a light transmittance of less than 70% at a wavelength of 400 nm under the condition that the solid content concentration is 5% by mass, and more preferably less than 50%. By maintaining the above range, the dispersibility of the binder in the aqueous medium is fully ensured, and when the slurry composition is prepared, the gaps between the inorganic particles are not filled and the ion permeability of the separator is not reduced. good. This improves battery performance such as internal resistance and cycle characteristics. In addition, when the binder is polymerized, high viscosity is suppressed, and the coating properties of the slurry composition are also excellent.

Furthermore, the light transmittance allows the light source to be split into measured wavelengths by a diffraction grating, and is calculated by the ratio of the light incident on the sample (l ₀ ) to the light penetrating the sample (l), as follows: (Formula 2) represents. (Formula 2) Penetration rate (%) = (l/l ₀ ) × 100

In addition, in the adhesive dispersion for non-aqueous secondary battery separators of the present invention, the polymer (A1) is in the form of particles, and the average particle diameter is preferably 10 nm to 4,000 nm at a solid content concentration of 1 mass %. More preferably, it is 100nm to 3,000nm. By being in the above range, the coatability is good, and when it is mixed with inorganic fine particles and used as a slurry composition for non-aqueous secondary battery separators, the gaps between the inorganic fine particles will not be filled and non-aqueous particles can be prevented. The internal resistance of the secondary battery increases. In addition, even if the molecular weight is large, high viscosity is suppressed, and heat resistance and coating properties can be achieved, so it is preferable.

The average particle diameter can be measured by diluting the adhesive dispersion with water to a solid content concentration of 1% by mass, for example, using a dynamic light scattering measurement method (the measuring device is NANOTRAC UPA, manufactured by Microtrac BEL Co., Ltd., etc.) and measuring approximately 5 ml of the diluted solution. Find out from this. The peak value of the volume particle size distribution data (histogram) obtained at this time was defined as the average particle size.

The viscosity of the adhesive dispersion for non-aqueous secondary battery separators is preferably 100 mPa·s or more and less than 15,000 mPa·s, and more preferably 500 mPa·s or more but less than 15,000 mPa·s at a solid content concentration of 15% by mass. 7000mPa・s. By being in the above range and having a molecular weight sufficient to express heat resistance and adhesion, the slurry composition also has excellent solution stability and coating properties. That is, the adhesive dispersion of the present invention is a particulate polymer, thereby suppressing the interaction between resins and achieving excellent workability such as coating properties despite having a high molecular weight. The viscosity can be measured using a B-type viscometer at 25° C., 20 rpm, and 60 seconds for rotation time.

[Slurry composition for separators of non-aqueous secondary batteries] The slurry composition for non-aqueous secondary battery separators is used to form a protective layer used in non-aqueous secondary battery separators, and at least contains the adhesive dispersion for non-aqueous secondary battery separators of the present invention and inorganic particles. Since the slurry composition for non-aqueous secondary battery separators of the present invention has good affinity between the binder dispersion and the inorganic particles, it has excellent solution stability and exhibits heat resistance and adhesion, thereby achieving good heat resistance of the separator. When the binder is polymerized to increase its adhesion and adhesion, the increase in viscosity is suppressed, and the coating properties of the slurry composition are also excellent. The slurry composition preferably contains the polymer (A2) if necessary. The polymer (A2) functions as an adhesive component and improves the adhesion to the separator base material, so it is preferred.

[Inorganic particles] The inorganic particles are preferably composed of inorganic compounds that do not deteriorate in the electrolyte of the non-aqueous secondary battery. Specific examples of the inorganic compound include alumina, hydrated alumina, silica, magnesia, calcium oxide, zirconium oxide, titanium oxide, silica, ion conductive glass, and the like. One type of inorganic compound may be used, or two or more types may be used in combination.

The average particle diameter of the inorganic fine particles is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.1 μm to 5 μm. By using inorganic particles with the aforementioned average particle diameter, the protective layer can achieve both film strength and lithium ion conductivity at a higher level. The average particle diameter of inorganic fine particles represents the particle diameter when the cumulative value from the small particle diameter side reaches 50% in the volume-based particle size distribution (volume distribution) using the laser diffraction/scattering method or the dynamic light scattering method.

It is preferable to use 0.1 to 10 parts by mass of the polymer (A1) based on 100 parts by mass of the inorganic fine particles, and more preferably to use 0.2 to 5 parts by mass. By being in the above range, it is possible to maintain the adhesion between the inorganic particles and the excellent adhesion of the protective layer to the separator, further improve the lithium ion conductivity of the protective layer, and suppress the internal resistance.

[Polymer(A2)] The slurry composition for nonaqueous secondary battery separators of the present invention preferably further contains polymer (A2), and polymer (A2) is a particulate polymer with a glass transition temperature (Tg) of -40°C to 40°C. . Furthermore, the polymer (A2) must exclude the situation corresponding to the polymer (A1). When a slurry composition is prepared, the polymer (A2) functions as a bonding component to the base material. The polymer (A2) is not limited as long as the glass transition temperature is -40°C to 40°C and it is in the form of particles. Acrylic resin, styrene acrylic resin, butadiene resin, olefin resin, and amine can be used. From the viewpoint of good mixing stability with the polymer (A1) and good adhesion to non-conductive fine particles or olefin substrates, arbitrary components such as methyl formate resin, polyester resin, polysaccharides and other natural polymers, Preferably, acrylic resin or styrene acrylic resin is used.

When polymer (A2) is used, the content of polymer (A2) in the slurry composition is preferably 200 parts by mass or less, more preferably 10 parts by mass to 100 parts by mass of polymer (A1). 100 parts by mass. By containing the polymer (A2) in the above range, the adhesion to the separator base material is improved, and the cycle characteristics are also excellent.

When the polymer (A2) is a polymer of an ethylenically unsaturated monomer, the same method as described for the polymer (A1) can be used to produce the polymer (A2). The polymer (A2) is a particulate polymer dispersed in an aqueous medium, thereby easily exhibiting adhesion to the base material. In addition, the average particle diameter of the polymer (A2) under the condition of a solid content concentration of 1% by mass is preferably 50 nm to 500 nm, more preferably 60 nm to 400 nm. By being in the above range, when the slurry composition is formed, the gaps between the inorganic fine particles are not filled, and the ion permeability of the separator becomes good.

The average particle diameter can be determined, for example, by measurement using a dynamic light scattering measurement method (the measuring device is NANOTRAC UPA, manufactured by Microtrac BEL Co., Ltd., etc.). The peak value of the volume particle size distribution data (histogram) obtained at this time was defined as the average particle size.

In the slurry composition for non-aqueous secondary batteries of the present invention, it is preferable to blend polymers other than polymer (A1) and polymer (A2), leveling agents, dispersants, thickeners, and defoaming agents. etc. as other optional ingredients. Examples of types of leveling agents include silicone-based, fluorine-based, metal-based, and succinic acid-based ones. Examples of the dispersant include anionic compounds, nonionic compounds, polymer compounds, and the like.

[Production method of slurry composition] The slurry composition for non-aqueous secondary batteries of the present invention is obtained by mixing the binder dispersion for non-aqueous secondary battery separators of the present invention, inorganic fine particles, and optional additives such as polymer (A2). The slurry composition can be obtained by, for example, dispersing inorganic fine particles using a dispersant and then mixing a binder dispersion liquid with any additives.

The slurry composition for non-aqueous secondary batteries of the present invention can be produced using a known disperser or mixer. Specific mixing devices include, for example, mixers such as dispersers, homogenizers, and planetary mixers; homogenizers; paint conditioners, ball mills, sand mills, grinders, bead mills, double mills, etc. Media-type dispersers such as ball mills (Coball Mill); media-less dispersers such as jet mills; and roller mills, etc. In addition, as the dispersing machine, it is preferable to use a dispersing machine that has been treated to prevent metal from being mixed from the dispersing machine. As the medium, ceramic beads such as glass beads, zirconia beads, and alumina beads are preferably used. Only one type of dispersion device may be used, or a plurality of devices may be used in combination.

[Non-aqueous secondary battery separator] The non-aqueous secondary battery separator of the present invention is provided with a protective layer composed of a slurry composition on at least one side of the separator base material. Through this protective layer, the heat resistance of the separator is improved, which can reduce the risk of explosion of the non-aqueous secondary battery due to a short circuit between the two electrodes when the non-aqueous secondary battery overheats.

The base material of the separator is a sheet or non-woven fabric having a porous layer with fine pores that allows ions to penetrate. Specifically, it can be formed using known raw materials such as polyolefins such as polyethylene and polypropylene, cellulose, and aromatic polyamides.

The method of forming the protective layer is preferably a method of applying a slurry composition. Specific examples of the coating method include: die coating method, dip coating method, roll coating method, knife coating method, knife coating method, spray coating method, gravure coating method, mesh coating method Printing method, electrostatic coating method, etc. In addition, it is preferable to dry the solvent during application. Specifically, known drying methods such as standing drying, air blow drying, hot air drying, infrared drying, and far infrared drying can be used. It is also possible to perform calendering using a lithographic press or calendering roller after coating.

The thickness of the protective layer is preferably 0.5 μm to 10 μm, more preferably 1 μm to 5 μm. By being in the above range, sufficient strength of the protective layer as a film can be ensured, and excellent battery performance can be exerted.

[Non-aqueous secondary battery] The non-aqueous secondary battery of the present invention will be described taking LIB as an example. LIB has at least: a battery body including a positive electrode, a negative electrode, and a separator provided between the positive electrode and the negative electrode; and an electrolyte impregnated in the battery body.

The positive electrode and the negative electrode (hereinafter, these positive and negative electrodes may also be referred to as "electrodes") include a current collector and a composite material layer formed of a composite material ink containing an electrode active material as an essential component.

General composite inks for storage devices use active substances and solvents as essential components, and may also contain conductive additives and adhesives as necessary. The active material is preferably contained as much as possible. For example, the proportion of the active material in the solid content of the composite ink is preferably 80 mass% to 99 mass%. When a conductive additive is included, the proportion of the conductive additive in the solid content of the composite ink is preferably 0.1 mass% to 15 mass%. When a binder is included, the proportion of the binder in the solid content of the composite ink is preferably 0.1% by mass to 15% by mass.

As the current collector, one applicable to various secondary batteries can be suitably selected. Examples of the material of the current collector include metals such as aluminum, copper, nickel, titanium, and stainless steel, and alloys of these metals. In the case of LIB, it is preferable to use a current collector made of aluminum for the positive electrode and a current collector made of copper for the negative electrode. In addition, as the shape, a flat foil is generally used, but a current collector with a roughened surface, a perforated foil-shaped current collector, and a mesh-shaped current collector can also be used. Furthermore, the thickness of the current collector is preferably 5 μm to 50 μm.

The positive electrode active material is not particularly limited, and metal compounds such as metal oxides and metal sulfides, conductive polymers, and the like that can be doped or intercalated with lithium ions can be used. Examples of the metal oxide or metal compound include oxides of transition metals such as Fe, Co, Ni, and Mn, composite oxides with lithium, and inorganic compounds such as transition metal sulfides. Specific examples of metal oxides or metal compounds include: transition metal oxide powders such as MnO, V ₂ O ₅ , V ₆ O ₁₃ , and TiO ₂ ; layered structures of lithium nickel oxide, lithium cobalt oxide, and manganate. Composite oxide powders of lithium and transition metals such as lithium and spinel structure lithium manganate; lithium iron phosphate-based materials that are olivine structure lithium oxygen compounds; transition metal sulfide powders such as TiS ₂ and FeS, etc.

The negative electrode active material is not particularly limited as long as it can be doped or intercalated with lithium ions. Examples of the negative electrode active material include metal Li, alloy systems such as tin alloys, silicon alloys, and lead alloys that are alloys of metal Li; metal oxide systems such as lithium titanate, lithium vanadate, and lithium silicate; and polyacetylene. , polyparaphenylene and other conductive polymer systems; amorphous carbonaceous materials such as soft carbon and hard carbon; artificial graphite such as highly graphitized carbon materials; carbonaceous powders such as natural graphite; carbon black, mesophase carbon black, resin burnt Burnt carbon materials, vapor deposition carbon fiber, carbon fiber and other carbon materials.

The conductive additive in the composite ink is not particularly limited as long as it is a conductive carbon material. Examples of conductive carbon materials include graphite, carbon black, conductive carbon fibers (carbon nanotubes, carbon nanofibers, carbon fibers), fullerene, and the like.

The binder in composite ink is used to bond particles such as active materials or conductive carbon materials to each other, or to bond conductive carbon materials to current collectors.

Examples of binders used in composite inks include: acrylic resin, polyurethane resin, polyester resin, phenol resin, epoxy resin, phenoxy resin, urea resin, melamine resin, alcohol Acid resin, formaldehyde resin, silicone resin, fluororesin, cellulose resin such as carboxymethylcellulose, synthetic rubber such as styrene-butadiene rubber or fluororubber, conductive resin such as polyaniline or polyacetylene, polydifluoride Ethylene, polyethylene fluoride, tetrafluoroethylene and other polymer compounds containing fluorine atoms. In addition, modified products, mixtures, or polymers of these resins may also be used.

Furthermore, in the composite ink, film-forming aids, defoaming agents, leveling agents, preservatives, pH adjusters, viscosity adjusters, etc. may be formulated as needed.

The electrolyte solution is a liquid obtained by melting an electrolyte containing lithium in a non-aqueous solvent. Specific examples of the electrolyte include 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, LiBPh ₄ , etc.

Examples of non-aqueous solvents include carbonates such as ethyl carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate; γ-butyrolactone , γ-valerolactone, γ-octanoic acid lactone and other lactones; tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,2 - Methoxyethane, 1,2-ethoxyethane, 1,2-dibutoxyethane and other glycol dimethyl ethers; esters such as methyl formate, methyl acetate and methyl propionate; Dimethyl sulfoxide, cyclobutane and other sulfoxides; acetonitrile and other nitriles, etc.

In addition, the electrolyte is preferably a polymer electrolyte formed into a gel by being held in a polymer matrix. Examples of the polymer matrix include an acrylic resin having a polyalkylene oxide segment, a polyphosphazene resin having a polyalkylene oxide segment, a polysiloxane resin having a polyalkylene oxide segment, and the like.

The non-aqueous secondary battery using the above-mentioned components has excellent safety and battery characteristics. The non-aqueous secondary battery of the present invention can be used for industrial applications, vehicle applications, and mobile applications. [Example]

Hereinafter, the present invention will be described in more detail through examples. However, the following examples do not limit the scope of rights of the present invention at all. In addition, "part" in the examples means "mass parts", "%" means "mass %", the numerical values in the table are the solid component mass, and the empty column means not used. In addition, the methods for measuring the average particle diameter of the inorganic fine particles and the glass transition temperature (Tg) of the polymer are as follows.

[Average particle size of inorganic particles] The average particle diameter of the inorganic fine particles is determined based on the particle diameter when the cumulative value from the small particle diameter side reaches 50% in the volume-based particle size distribution (volume distribution) using the laser diffraction/scattering method.

[glass transition temperature] The glass transition temperature of the polymer was measured using DSC (Differential Scanning Thermal Analyzer, manufactured by TA Instruments). Specifically, an accurately weighed aluminum pot in which approximately 3 mg of dried resin was added and an empty aluminum pot used as a reference were placed on a DSC measurement stand, and the temperature was measured at a temperature rise of 10°C/min. The temperature at the intersection of the reference line on the low-temperature side of the endothermic phenomenon in the obtained DSC curve and the tangent line at the inflection point was set as the glass transition temperature (Tg).

[Preparation of polymer (A2-1) dispersion] To a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a refluxer, 40 parts of ion-exchange water and 0.2 part of Aqualon KH-10 (manufactured by Daiichi Industrial Pharmaceutical Co., Ltd.) as a surfactant were added, and further Add 61 parts of 2-ethylhexyl acrylate, 30 parts of methyl methacrylate, 7 parts of styrene, 0.5 parts of methacrylamide, 1.5 parts of acrylic acid, 53 parts of ion exchange water and surfactant 1% of Aqualon KH-10 (manufactured by Daiichi Industrial Pharmaceutical Co., Ltd.) 1.8 parts of pre-mixed pre-made emulsion. After the internal temperature was raised to 60°C and nitrogen substitution was sufficiently carried out, 10 parts of a 5% aqueous solution of potassium persulfate and 10% of 20 parts of a 1% aqueous solution of anhydrous sodium bisulfite were added to start polymerization. After maintaining the reaction system at 60°C for 5 minutes, while maintaining the internal temperature at 60°C, the remaining part of the pre-made emulsion, a 5% aqueous solution of potassium persulfate, and 1% of anhydrous sodium bisulfite were added dropwise over 1.5 hours. % of the remaining aqueous solution, and continue stirring for 2 hours. After confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30°C. 25% ammonia water was added to adjust the pH to 8.5, and the solid content was further adjusted to 40% using ion-exchange water to obtain a polymer (A2-1) dispersion with a Tg of -12°C. In addition, the solid content was determined from the remaining content after baking at 150° C. for 20 minutes.

[Example 1] [Manufacture of adhesive dispersion for non-aqueous secondary battery separators] Mix 66 parts of acrylamide, 32 parts of tert-butyl methacrylate, 2 parts of 1,9-nonanediol diacrylate, 1.0 parts of 20% Emal 2FG aqueous solution, and 90 parts of ion-exchange water to obtain a mixed solution . To a reaction vessel equipped with a mixer, a thermometer, a dropping funnel, and a refluxer, 450 parts of water and 30 parts of the above mixed solution were added. Next, the internal temperature of the reaction vessel was raised to 80° C. and nitrogen substitution was sufficiently carried out. Then, 2.0 parts of a 10% ammonium persulfate aqueous solution (0.2 parts of solid content) as a initiator was added to start the reaction. While maintaining the internal temperature at 80°C, the mixed liquid was added dropwise over 60 minutes. After completion of the dropwise addition, the reaction was further carried out at 80°C for 3 hours. After confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30°C. The solid content was adjusted to 15% using ion-exchange water to obtain a binder dispersion for non-aqueous secondary battery separators containing the polymer (A1-1). In addition, the solid content was determined from the remaining content after baking at 150° C. for 20 minutes.

[Example 2 to Example 24, Comparative Example 1 to Comparative Example 7] Except for setting the blending composition and blending amount (mass parts) as shown in the table, by the same method as Example 1, a polymer containing polymers (A1-2 to A1-24) or polymers (A3-1 to A3-7) Adhesive dispersion for non-aqueous secondary battery separators. In addition, regarding Example 4, Example 6, Example 12 and Comparative Example 5, after the reaction was completed, 25% ammonia water was added to neutralize it so that it became equimolar with respect to the carboxyl groups in the resin. In Example 21 and Example 24, aggregates were confirmed during polymerization. In addition, Comparative Example 7 could not be synthesized due to poor polymerization stability.

The physical property values and evaluation results of the obtained polymer and binder dispersion for non-aqueous secondary battery separators were determined by the following method. The results are shown in the table.

[acid value] The acid value of the polymer is the number of mg of potassium hydroxide required to neutralize the acidic components contained in 1 g of the dried resin. It was calculated based on the method described in JIS K2501 by performing potentiometric titration with a potassium hydroxide/ethanol solution using an automatic titration device ("COM-A19" manufactured by HIRANUMA Corporation).

[Light transmittance] The obtained adhesive dispersion was adjusted to a solid content concentration of 5% using ion-exchange water, and was added to a quartz cell with an optical path length of 1 cm. A spectrophotometer ("V-770" manufactured by JASCO Corporation) was used to measure the concentration of the adhesive dispersion. Penetration spectrum at wavelength 400nm. The comparison object is ion exchange water. A: The light penetration rate does not reach 50%. B: The light transmittance is more than 50% and less than 70%. C: Light penetration rate is above 70%.

[Storage elastic modulus] The obtained adhesive dispersion was dried at 40°C for 72 hours to prepare a film with a thickness of approximately 0.5 mm. The obtained film was cut into strips with a width of 5 mm and a length of 20 mm to prepare a sample, and the storage elasticity modulus at 150°C was measured using a dynamic viscoelasticity measuring device ("DVA-200" manufactured by IT Measurement Control Co., Ltd.). Count. The measurement conditions are as follows. Measurement mode: Tensile frequency: 10Hz Strain: 0.01% Heating condition: 10°C/min A: Storage elastic modulus is 1.0×10 ⁷ Pa or above. B: The storage elastic modulus is from 1.0×10 ⁶ to less than 1.0×10 ⁷ Pa. C: The storage elastic modulus does not reach 1.0×10 ⁶ Pa.

[viscosity] The viscosity of the obtained adhesive dispersion with a solid content concentration of 15% was measured using a B-type viscometer ("TVB-10" manufactured by Toki Industrial Co., Ltd.) (temperature: 25°C, spindle rotation time: 60 seconds, spindle rotation speed :20rpm). A: The viscosity is from 500 to less than 7000mPa·s. B: The viscosity is more than 100 and less than 500mPa·s. B': Viscosity is from 7000 to less than 15,000mPa·s. C: The viscosity does not reach 100mPa・s. C': Viscosity is 15,000mPa·s or more.

[average particle size] The average particle size was measured by diluting a polymer solution to a solid content concentration of 1% by mass and measuring about 5 ml of the diluted solution by a dynamic light scattering measurement method (the measuring device is NANOTRAC UPA, manufactured by Microtrac BEL Co., Ltd.). The peak value of the volume particle size distribution data (histogram) obtained at this time was defined as the average particle size. A: The average particle diameter is from 100 nm to less than 3,000 nm. B: The average particle diameter is from 3,000 nm to less than 4,000 nm or from 10 nm to less than 100 nm. C: The average particle diameter is less than 10 nm or 4,000 nm or more.

[Evaluation of adhesive dispersion] [Electrolyte resistance] Electrolyte resistance refers to the ease with which the polymer melts and swells in the electrolyte, and is evaluated by the swelling degree of the electrolyte. It can be said that the smaller the electrolyte swelling degree, the better the electrolyte resistance is. The obtained adhesive dispersion was dried at 40° C. for 72 hours to prepare a film with a thickness of about 1 mm. Next, the film was cut into a length of 10 mm × a width of 10 mm to prepare a sample, and the sample was immersed in a mixed solvent of ethylene carbonate and diethyl carbonate at a volume ratio of 2:3 at 60° C. for 72 hours. The swelling degree of the film before and after immersion was calculated as follows. Swelling degree (times): = (mass after immersion)/(mass before immersion) A: The swelling degree does not reach 1.5 times. B: The swelling degree is from 1.5 times to less than 2 times. C: The swelling degree is 2 times or more.

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Polymer(A) Name logKow Polymer A1-1 Polymer A1-2 Polymer A1-3 Polymer A1-4 Polymer A1-5 Polymer A1-6 Polymer A1-7 Polymer A1-8 Polymer A1-9 Polymer A1-10 Polymer A1-11 acrylamide -0.87 66 60 69 71 61 65 74 66 66 77 51 Methacrylamide 0 2 5 6.8 4 Nonionic monomer (a-1) tBA 2.06 2 2 32 BA 2.23 36 5 25 20 20 tBMA 2.67 32 16 12 25 16 20 St 3.06 27 2 9 2EHA 4.01 2 32 1,4-BDDMA 2.98 Other monomers (a-2) AA 0.2 1 1.2 2HEA 0.01 2HEMA 0.7 2 1 3 MMA 1.13 1 1 iNA 4.44 2 3 1,9-NDDA 5.44 2 2 2 Acid value (mgKOH/g) 0.0 0.0 0.0 7.8 0.0 9.3 0.0 0.0 0.0 0.0 0.0 surfactant 20%Emal 2FG 1.0 1.0 1.0 1.0 1.0 1.0 2.0 1.0 1.0 1.0 1.0 10% ammonium persulfate aqueous solution 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Physical value light transmittance A A A A A A A A A B A Store elastic modulus A A A A A A A A A A B viscosity A A A A A A A B' B B B average particle size A A A A A A A A A A A Evaluation Electrolyte resistance A A A A A A A A A A B

[Table 2] Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 Example 22 Polymer(A) Name logKow Polymer A1-12 Polymer A1-13 Polymer A1-14 Polymer A1-15 Polymer A1-16 Polymer A1-17 Polymer A1-18 Polymer A1-19 Polymer A1-20 Polymer A1-21 Polymer A1-22 acrylamide -0.87 60 75 63 63 15 66 66 60 60 68 68 Methacrylamide 0 2.1 44 2 2 2 2 Nonionic monomer (a-1) tBA 2.06 20 BA 2.23 36 1 30 30 36 36 28 28 tBMA 2.67 4 32 32 St 3.06 35 2EHA 4.01 5 5 1,4-BDDMA 2.98 Other monomers (a-2) AA 0.2 1.9 2HEA 0.01 2HEMA 0.7 3 2 2 2 2 MMA 1.13 1 iNA 4.44 2 2 2 1,9-NDDA 5.44 2 2 Acid value (mgKOH/g) 14.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 surfactant 20%Emal 2FG 1.0 2.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.3 10.0 10% ammonium persulfate aqueous solution 2.0 2.0 2.0 3.5 2.0 3.5 1.0 4.0 0.5 2.0 2.0 Physical value light transmittance A B A B A A A A A A A Store elastic modulus A A B C B B A B A A A viscosity A B' A B A B B' C C' A A average particle size A B A B A A A A A A A Evaluation Electrolyte resistance A A B B C B A B A A A

[table 3] Example 23 Example 24 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 Polymer(A) Name logKow Polymer A1-23 Polymer A1-24 Polymer A3-1 Polymer A3-2 Polymer A3-3 Polymer A3-4 Polymer A3-5 Polymer A3-6 Polymer A3-7 acrylamide -0.87 68 70 62 29 85 48 58 77 68 Methacrylamide 0 2 30 2 4 2 Nonionic monomer (a-1) tBA 2.06 11 16 BA 2.23 28 36 28 tBMA 2.67 12 St 3.06 7 40 2EHA 4.01 2 1,4-BDDMA 2.98 twenty one Other monomers (a-2) AA 0.2 4 2HEA 0.01 38 2 4 2HEMA 0.7 2 2 2 MMA 1.13 2 1 iNA 4.44 38 1,9-NDDA 5.44 Acid value (mgKOH/g) 0.0 0.0 0.0 0.0 0.0 0.0 31.1 0.0 0.0 surfactant 20%Emal 2FG 30.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.0 10% ammonium persulfate aqueous solution 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Physical value light transmittance A A C A C A A C - Store elastic modulus A A B B A C A A - viscosity B' C' C C C' C A C' - average particle size A A C A C A A C - Evaluation Electrolyte resistance A A A B A C A A -

In addition, the abbreviations in the table are as follows. The Log Kow value of the ethylenically unsaturated monomer is expressed by converting the structural formula of the ethylenically unsaturated monomer into Smiles using the YMB method (physical property estimation function) of the Hansen melting parameter software HSPiP (ver.5.2.05) It is calculated by inputting the method. [Nonionic ethylenically unsaturated monomer (a-1)] t-BA: tert-butyl acrylate (Log Kow 2.06) BA: Butyl acrylate (Log Kow 2.23) t-BMA: tert-butyl methacrylate (log Kow 4.01) St: Styrene (Log Kow 3.06) 2EHA: 2-ethylhexyl acrylate (Log Kow 0.82) 1,4-BDDMA: 1,4-butanediol dimethacrylate (Log Kow 2.98) [Other ethylenically unsaturated monomer (a-2)] AA: Acrylic (Log Kow 0.2) 2HEA: Hydroxyethyl acrylate (Log Kow 0.01) 2HEMA: Hydroxyethyl methacrylate (Log Kow 0.7) MMA: Methyl Methacrylate (Log Kow 1.13) iNA: Isononyl acrylate (Log Kow 4.44) 1,9-NDDA: 1,9-nonanediol diacrylate (Log Kow 5.44)

[Example 25] [Preparation of slurry composition for non-aqueous secondary battery separators] 42.4 parts of inorganic fine particles (alumina, average particle diameter 0.5 μm), 0.5 parts of ammonium polycarboxylate (BYK-154) as a dispersant, and 42.7 parts of water were put into a bead mill to prepare an alumina dispersion. To the obtained alumina dispersion, carboxymethyl cellulose (CMC, Daicel 1220) equivalent to 1.1 parts in solid content of the binder dispersion containing the polymer (A1-1) was added as a thickener. 0.6 parts of 4% aqueous solution, 0.3 parts of silicone active agent (BYK-349) as a wetting agent, and 0.2 parts of silicone defoaming agent (BYK-018) are added to water so that the solid content concentration becomes 43%. These components are mixed to prepare a slurry composition for non-aqueous secondary battery separators.

[Production of separators for non-aqueous secondary batteries] The above-mentioned slurry composition was applied to one side of the separator base material (9 μm porous polyethylene film) so that the thickness became 3 μm using a doctor blade. Then, it is dried in an oven at 80° C. to obtain a separator with a protective layer.

[Preparation of positive electrode] Add 93 parts of LiNi _0.5 Mn _0.3 Co _0.2 O ₂ as the positive electrode active material, 4 parts of acetylene black as the conductive agent, 3 parts of polyvinylidene fluoride as the binder, and 45 parts of N-methylpyrrolidone. Mix to produce composite ink for positive electrodes. The obtained positive electrode composite ink was applied to a 20 μm-thick aluminum foil serving as a current collector using a doctor blade, and then heated and dried at 80° C. to adjust the basis weight per unit area of the electrode to 20 mg/cm ² . Furthermore, a rolling process using a roller press was performed to produce a positive electrode with a density of the composite material layer of 3.1 g/cm ³ .

Add 98 parts of artificial graphite as the negative electrode active material and 66.7 parts of 1.5% carboxymethyl cellulose aqueous solution (1 part in terms of solid content) to the planetary mixer for kneading. Add 33 parts of water, styrene butadiene Mix 2.08 parts of the 48% aqueous dispersion of the vinyl emulsion (1 part in terms of solid content) to prepare a composite ink for negative electrodes. The obtained negative electrode composite ink was applied to a 20-μm-thick copper foil serving as a current collector using a doctor blade, and then heated and dried at 80° C. to adjust the basis weight per unit area of the electrode to 12 mg/cm ² . Furthermore, a rolling process using a roller press was performed to produce a negative electrode with a density of the composite material layer of 1.5 g/cm ³ .

[Preparation of non-aqueous secondary batteries] Punch the positive electrode and negative electrode into 45mm×40mm and 50mm×45mm respectively. Make the positive electrode and negative electrode face each other through a separator with a protective layer and insert it into an aluminum laminated bag. After vacuum drying, inject the electrolyte (ethyl carbonate and diethyl carbonate at a volume ratio of 2:3). A non-aqueous electrolyte solution (a non-aqueous electrolyte solution in which LiPF ₆ is melted at a concentration of 1M in a mixed solvent) is laminated and sealed to produce a laminated non-aqueous secondary battery.

[Example 26 to Example 48, Example 52 to Example 53, Comparative Example 8 to Comparative Example 14] Except for changing the composition and compounding amount (mass parts) shown in the table, a slurry composition for non-aqueous secondary battery separators and a non-aqueous secondary battery separator were produced in the same manner as in Example 24. parts, non-aqueous secondary batteries.

[Example 49] Put 42.4 parts of inorganic fine particles (alumina, average particle size 0.5 μm), 0.5 parts of ammonium polycarboxylate (BYK-154) as a dispersant, and 42.7 parts of water into a bead mill to prepare an alumina dispersion. . To the obtained alumina dispersion, a binder dispersion containing polymer (A1-11) equivalent to 1.0 part in terms of solid content and a polymer (A2-1) dispersion equivalent to 1.0 part in terms of solid content were added. 0.1 part, 0.6 part of 4% aqueous solution of carboxymethyl cellulose (CMC, Daicel 1220) as a tackifier, 0.3 part of a silicone active agent (BYK-349) as a wetting agent, and a silicone defoaming agent (BYK- 0.2 part of 018), after adding water so that the solid content concentration becomes 43%, these components are mixed to prepare a slurry composition for non-aqueous secondary battery separators.

[Example 50 to Example 51] A slurry composition for non-aqueous secondary battery separators, a non-aqueous secondary battery separator, and Non-aqueous secondary batteries.

The obtained slurry composition for non-aqueous secondary battery separators was used to evaluate the solution stability and coating properties using the following method, and the non-aqueous secondary battery separators were used to evaluate the close contact between the protective layer and the separator base material. properties, moisture content, and heat resistance, and use non-aqueous secondary batteries to evaluate initial resistance and cycle characteristics. The results are shown in the table.

[Evaluation of slurry composition] [Solution stability] The slurry composition was stored at 50° C. and visually observed for aggregation, precipitation, and separation. [Evaluation criteria] A: No abnormality was observed for more than 4 weeks from the start of storage. Extremely good. B: Some abnormalities were observed between more than 1 week and less than 4 weeks from the start of storage. good. C: Some abnormalities were observed between more than 4 days and less than 1 week from the start of storage. be usable. D: Some abnormalities were observed within 3 days from the start of preservation. There are practical problems.

[Coatability] Using the obtained separator, the applicability of the slurry composition was visually observed. [Evaluation criteria] A: The film thickness is uniform and there are no coverage gaps. Extremely good. B: There is unevenness or coverage gaps in less than 5% of the coated area. good. C: There is unevenness or coverage gaps in more than 5% to less than 10% of the coated area. be usable. D: There is unevenness or coverage gaps in more than 10% of the coated area. There are practical problems.

[Evaluation of Separators] [Heat Resistance of Separators] The separators were cut into MD (traveling direction) 100 mm × TD (vertical direction) 100 mm to prepare samples. Sandwich the sample between three pieces of paper and let it stand in an oven at 150°C for 2 hours. After the sample was taken out of the oven and cooled, the shrinkage rate was calculated as follows. Sample area (mm ² ) = (MD length of the sample) × (TD length of the sample) Shrinkage (%): = [1-(Sample area after heating)/(Sample area before heating) ]×100 [Evaluation criteria] A: The shrinkage rate is less than 7%. Extremely good. B: The shrinkage rate is more than 7% and less than 15%. good. C: The shrinkage rate is more than 15% and less than 30%. It can be used practically. D: Shrinkage rate is more than 30%. There are practical problems.

[Moisture content of separator] Let the separator stand for 3 days at a temperature of 23°C and a humidity of 50%. Use a vaporization device (VA-100 manufactured by Mitsubishi Chemical Corporation) to extract moisture at a vaporization temperature of 120°C. Use Karl Fischer moisture. A measuring device (CA-100 manufactured by Mitsubishi Chemical Corporation) measured the amount of extracted water. [Evaluation criteria] A: The moisture content does not reach 1,500ppm. Extremely good. B: The moisture content is from 1,500 ppm to less than 2,000 ppm. good. C: The moisture content is from 2,000 ppm to less than 3,000 ppm. It can be used practically. D: The moisture content is 3,000ppm or more. There are practical problems.

[Adhesion between the protective layer and the separator base material] Cut the obtained separator with a protective layer into a width of 25 mm and a length of 100 mm, and use double-sided tape to bond the base material side of the separator to the stainless steel plate. Attach a transparent tape with a width of 18mm to the side of the protective layer and roll it with a load of 1kg. After letting it stand for 24 hours at a temperature of 25°C and a humidity of 50%, stretch one end of the transparent tape in the 180° direction, and measure the peel strength (peel strength) using a tensile testing machine ("AGS-X" manufactured by Shimadzu Corporation). Speed: 10mm/min, unit: N/18mm width). [Evaluation criteria] A: Peel strength is 3N/18mm or more. Extremely good. B: Peeling strength is from 2N/18mm to less than 3N/18mm. good. C: Peeling strength is from 1.5N/18mm to less than 2N/18mm. It can be used practically. D: Peeling strength does not reach 1.5N/18mm. There are practical problems.

[Evaluation of non-aqueous secondary batteries] [Internal resistance] Internal resistance is the time it takes for 100ml of air to pass through the sample, and is evaluated by air permeability. There is a tendency that the shorter the time required, the smaller the internal resistance, which can be said to be a better internal resistance. According to the method described in JIS P8117, the air permeability was measured using a Gehrig air permeability testing machine ("G-B3C" manufactured by Toyo Seiki Seisakusho). [Evaluation criteria] A: Less than 250 seconds/100ml. Extremely good. B: 250 seconds/100ml or more but less than 270 seconds/100ml. good. C: 270 seconds/100ml or more but less than 280 seconds/100ml. It can be used practically. D: 280 seconds/100ml or more. There are practical problems.

[Cycle characteristics] In a 50°C constant temperature bath, the charging current is 60mA and the charge end voltage is 4.2V. After constant current and constant voltage charging (cutoff current 0.6mA), constant current discharge is performed with a discharge current of 60mA until the charge end voltage is 3.0V. , find the initial discharge capacity. This charge and discharge cycle was performed 200 times, and the discharge capacity maintenance rate (the percentage of the 10th discharge capacity relative to the first discharge capacity) was calculated. It can be said that the higher the discharge capacity maintenance rate, the better the cycle characteristics. [Evaluation criteria] A: The discharge capacity maintenance rate is over 90%. Extremely good. B: The discharge capacity maintenance rate is more than 85% and less than 90%. good. C: The discharge capacity maintenance rate is more than 80% and less than 85%. It can be used practically. D: The discharge capacity maintenance rate does not reach 80%. There are practical problems.

[Table 4] Inorganic filler Polymer(1) Polymer(2) coating agent divider Non-aqueous secondary battery Dispensing amount (portions) Kind Dispensing amount (portion) Kind Dispensing amount (portions) solution stability Spreadability heat resistance Moisture content Tightness Internal resistance Cycle characteristics Example 25 42.4 Polymer(A1-1) 1.1 ― ― A A A A A A A Example 26 42.4 Polymer(A1-2) 1.1 ― ― A A A A A A A Example 27 42.4 Polymer(A1-3) 1.1 ― ― A A A A A A A Example 28 42.4 Polymer(A1-4) 1.1 ― ― A A A A A A A Example 29 42.4 Polymer(A1-5) 1.1 ― ― A A A A A A A Example 30 42.4 Polymer(A1-6) 1.1 ― ― A A A A A A A Example 31 42.4 Polymer(A1-7) 1.1 ― ― A A A A A A A Example 32 42.4 Polymer(A1-8) 1.1 ― ― A B A B A A B Example 33 42.4 Polymer(A1-9) 1.1 ― ― A B B A B A B Example 34 42.4 Polymer(A1-10) 1.1 ― ― A B A B A B B Example 35 42.4 Polymer(A1-11) 1.1 ― ― A B C A C B B Example 36 42.4 Polymer(A1-12) 1.1 ― ― C A A A A A B Example 37 42.4 Polymer(A1-13) 1.1 ― ― A B A B A C B Example 38 42.4 Polymer(A1-14) 1.1 ― ― A A B A B B B Example 39 42.4 Polymer(A1-15) 1.1 ― ― B B C A C B C Example 40 42.4 Polymer(A1-16) 1.1 ― ― A A B A B C B Example 41 42.4 Polymer(A1-17) 1.1 ― ― A B B A B A B Example 42 42.4 Polymer(A1-18) 1.1 ― ― A B A A A A B Example 43 42.4 Polymer(A1-19) 1.1 ― ― A C C A C A C Example 44 42.4 Polymer(A1-20) 1.1 ― ― A C A A A A B Example 45 42.4 Polymer(A1-21) 1.1 ― ― C A A A A A B Example 46 42.4 Polymer(A1-22) 1.1 ― ― A A A C A C B Example 47 42.4 Polymer(A1-23) 1.1 ― ― A A A C A C C Example 48 42.4 Polymer(A1-24) 1.1 ― ― C C A A C B C Example 49 42.4 Polymer(A1-11) 1 Polymer(A2-1) 0.1 A B C A B B B Example 50 42.4 Polymer(A1-11) 0.6 Polymer(A2-1) 0.5 A B C A B B B Example 51 42.4 Polymer(A1-11) 0.35 Polymer(A2-1) 0.75 A B C A A B C Example 52 42.4 Polymer(A1-1) 0.8 ― ― A A A A A A A Example 53 42.4 Polymer(A1-1) 1.5 ― ― A A A A A A A Comparative example 8 42.4 Polymer(A3-1) 1.1 ― ― A C A C A C D Comparative example 9 42.4 Polymer(A3-2) 1.1 ― ― A C C A C A D Comparative example 10 42.4 Polymer(A3-3) 1.1 ― ― A C A D A D C Comparative example 11 42.4 Polymer(A3-4) 1.1 ― ― A C D A D B D Comparative example 12 42.4 Polymer(A3-5) 1.1 ― ― D D C B C B D Comparative example 13 42.4 Polymer(A3-6) 1.1 ― ― A C A C A D C Comparative example 14 42.4 Polymer(A2-1) 1.1 ― ― D B D A B B D

As shown in Table 4, it was confirmed that the solution stability and coating properties of the slurry composition prepared using the binder dispersion for non-aqueous secondary battery separators of the Examples were good, and the heat resistance of the separator was good. And the adhesiveness is good, and when it is made into a secondary battery, the internal resistance is small and the cycle characteristics are excellent. The adhesive dispersion for non-aqueous secondary battery separators in the aforementioned embodiment includes polymer (A), surfactant, and aqueous medium. And under the condition that the solid content concentration is 5% by mass, the light transmittance at 400nm does not reach 70%. The aforementioned polymer (A) is based on the total mass of the ethylenically unsaturated monomer (a), so that (methyl ) 50% by mass to 85% by mass of acrylamide, and 15% by mass of a nonionic ethylenically unsaturated monomer (a-1) with a logarithm of the octanol/water partition coefficient (LogKow) at 25°C of 1.9 to 4.2 It is polymerized to 50% by mass, and the acid value is 15 mgKOH/g or less. On the other hand, in Comparative Example 7 containing no surfactant, the polymerization stability was significantly poor. In any of the results using Comparative Examples 1 to 6 or the slurry composition for non-aqueous secondary battery separators, non-aqueous secondary battery separators, and non-aqueous secondary batteries not containing the polymer (A1) The physical properties are extremely poor and cannot be said to meet the practical level.

This application claims priority based on Japanese Application No. 2022-1818 filed on January 7, 2022, and all the contents disclosed in the application are incorporated into this article.

Claims (9)

An adhesive dispersion for non-aqueous secondary battery separators, including polymer (A1), surfactant, and aqueous medium; The polymer (A1) has an acid value of 15 mgKOH/g or less, and contains 50 to 85 mass% of (meth)acrylamide based on the total mass of the ethylenically unsaturated monomer mixture, and octane at 25°C. A polymer of an ethylenically unsaturated monomer mixture of 15 mass % to 50 mass % of nonionic ethylenically unsaturated monomer (a-1) with a log Kow of alcohol/water partition coefficient of 1.9 to 4.2; Under the condition of solid content concentration of 5% by mass, the transmittance of light with a wavelength of 400nm is less than 70%. The adhesive dispersion for non-aqueous secondary battery separators as described in claim 1, wherein the storage elastic modulus of the polymer (A1) at 150°C is 1.0×10 ⁶ Pa or more. The adhesive dispersion for non-aqueous secondary battery separators as described in claim 1 or 2, wherein the polymer (A1) is in a mixed solvent with a volume ratio of ethylene carbonate and diethyl carbonate of 2:3. When immersed at 60°C for 72 hours, the swelling degree of the electrolyte did not reach 2 times. The adhesive dispersion for non-aqueous secondary battery separators as described in claim 1 or 2 has a viscosity of 100 mPa·s or more and less than 15,000 mPa·s when the solid content concentration is 15 mass%. The adhesive dispersion for non-aqueous secondary battery separators as described in claim 3 has a viscosity of 100 mPa·s or more and less than 15,000 mPa·s when the solid content concentration is 15% by mass. A slurry composition for separators of non-aqueous secondary batteries, including inorganic particles and the adhesive dispersion for separators of non-aqueous secondary batteries as described in any one of claims 1 to 5. The slurry composition for non-aqueous secondary battery separators according to claim 6, which further contains a polymer (A2) other than the polymer (A1); Polymer (A2) is a particulate polymer with a glass transition temperature of -40°C to 40°C. A non-aqueous secondary battery separator, which is formed by providing a protective layer on at least one side of the separator base material, and the protective layer is made of the slurry for non-aqueous secondary battery separators as described in claim 6 or 7. formed by the composition. A non-aqueous secondary battery provided with the non-aqueous secondary battery separator as described in claim 8.