Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
  • C08F220/1806—C6-(meth)acrylate, e.g. (cyclo)hexyl (meth)acrylate or phenyl (meth)acrylate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
  • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
  • C08F20/10—Esters
  • C08F20/12—Esters of monohydric alcohols or phenols
  • C08F20/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F20/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/20—Esters of polyhydric alcohols or phenols, e.g. 2-hydroxyethyl (meth)acrylate or glycerol mono-(meth)acrylate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/22—Esters containing halogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F222/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical and containing at least one other carboxyl radical in the molecule; Salts, anhydrides, esters, amides, imides, or nitriles thereof
  • C08F222/10—Esters
  • C08F222/1006—Esters of polyhydric alcohols or polyhydric phenols
  • C08F222/106—Esters of polycondensation macromers
  • C08F222/1063—Esters of polycondensation macromers of alcohol terminated polyethers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/409—Separators, membranes or diaphragms characterised by the material
  • H01M50/411—Organic material
  • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
  • H01M50/42—Acrylic resins
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/409—Separators, membranes or diaphragms characterised by the material
  • H01M50/443—Particulate material
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present invention relates to polymer particles capable of forming a coating film with excellent swelling-suppressing properties against electrolytic solutions.
• Polymer particles are used for binder resin applications aimed at improving the battery characteristics of lithium-ion secondary batteries, and for the purpose of imparting adhesiveness by coating various substrates. Polymer particles are required to have various properties depending on the applications in which they are used, and various proposals have been made to meet these requirements (see, for example, Patent Documents 1 to 3).
• the present invention provides polymer particles that are capable of forming a coating film with excellent swelling-suppressing properties against electrolytic solutions.
• the polymer particles of the present invention are polymer particles comprising a polymer containing a structural unit derived from a (meth)acrylate monomer, and the HSP polar component (X) of the polymer is 7.0 MPa 1/ Polymer particles having a weight average molecular weight of less than 2 and of 10,000 to 1,000,000. is.
• the polymer particles of the present invention provide polymer particles that are capable of forming a coating film with excellent swelling-suppressing properties against electrolytic solutions. By adding the polymer particles of the present invention to the coating film, it is possible to express the swelling-suppressing property against the electrolytic solution.
• the HSP polar component (X) of the polymer constituting the polymer particles is less than 7.0 MPa 1/2 .
• the upper limit of the HSP polar component (X) of the polymer is preferably 6.8 MPa 1/2 or less, more preferably 6.6 MPa 1/2 or less, even more preferably 6.4 MPa 1/2 or less, still more preferably 6 .2 MPa 1/2 or less, particularly preferably 6.0 MPa 1/2 or less.
• the lower limit of the HSP polar component (X) of the polymer is preferably 3.0 MPa 1/2 or more.
• the HSP polar component (X) of the polymer can be adjusted by changing the type and composition ratio of the monomers constituting the polymer.
• the "HSP polar component (X) of the polymer” is measured by the following method. First, polymer particles are formed into a sheet having a thickness of about 1 to 2 mm by a hot press. A sheet-like material obtained from the polymer particles is hereinafter referred to as a particle film.
• the HSP polar component (X) of the polymer is determined by conducting the following swelling test using a particle film obtained from polymer particles. About 70 to 90 mg of a test piece obtained by cutting a particle film into a square of several mm is immersed in about 2 mL of a test solvent and allowed to stand at room temperature for about 2 weeks.
• Test solvents include n-hexane, N,N-dimethylformamide, cyclohexane, ⁇ -butyrolactone, methyl isobutyl ketone, ethanol, n-butyl acetate, dimethyl sulfoxide, toluene, methanol, tetrahydrofuran, 2-aminoethanol, methyl ethyl ketone, and cyclohexanone. , chloroform, methyl acetate, acetone, 1,4-dioxane, pyridine, N-methylpyrrolidone, hexafluoroisopropanol, 1-butanol, acetonitrile and diethylene glycol. to confirm.
• the resulting swelling test was calculated using HSPiP (Hansen Solubility Parameter in Practice) ver. 5.2.05 to obtain Hansen's lysates.
• the Hansen solubility sphere is obtained by plotting the Hansen solubility parameters (dispersion component, polar component, hydrogen bond component) of a solvent judged to be a good solvent in the swelling test described above in a three-dimensional space.
• the center of the obtained dissolving sphere is the measured Hansen solubility parameter of the polymer, and the polar component of the solubility parameter is defined as the HSP polar component (X) of the polymer.
• a swelling test for solvents other than the above 24 solvents may be added.
• additional test solvents include, for example, 2-phenoxyethanol, cyclohexanol, dibasic esters, diacetone alcohol, dipropylene glycol, ethyl acetate, dichloromethane, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene carbonate.
• tetrachloroethylene acetic acid, benzene, cyclohexyl acetate, formamide, 2-ethoxyethanol, isobutanol, isobutyric acid, xylene, diethyl ether, ethylene glycol, glycerin, chlorobenzene, diiodomethane, cyclopentanone, nitrobenzene, 1,2-dichlorobenzene, isophorone, furfural, diisopropyl ketone, mesityl oxide, aniline, carbon disulfide, carbon tetrachloride, 1,2-bromoethane, N,N-dimethylacetamide, tetralin, m-cresol, 2-nitropropane, quinoline, 1-bromo
• One or more can be selected from naphthalene and 1,1,2,2-tetrabromoethane. The selection of these solvent types is not univocally determined, and varies depending on the types and amounts
• the weight-average molecular weight of the polymer constituting the polymer particles of the present invention is 10,000 or more and 1,000,000 or less. By setting the weight-average molecular weight of the polymer within the above range, it is possible to obtain polymer particles that are excellent in suppressing swelling in an electrolytic solution.
• the lower limit of the weight average molecular weight of the polymer is preferably 100,000 or more, more preferably over 100,000, still more preferably 110,000 or more, still more preferably 140,000 or more, still more preferably 190,000 or more, and particularly preferably 230,000. It should be above.
• the upper limit of the weight average molecular weight of the polymer is preferably 900,000 or less, more preferably 800,000 or less, still more preferably 700,000 or less, still more preferably 600,000 or less, and particularly preferably 500,000 or less.
• weight average molecular weight of a polymer refers to the weight average molecular weight in terms of polymethyl methacrylate, measured according to JIS K7252-1:2016.
• composition of the polymer constituting the polymer particles contains a structural unit derived from a (meth)acrylic acid ester monomer, the HSP polar component (X) of the polymer is less than 7.0 MPa 1/2 , and the polymer is There is no particular limitation as long as the weight average molecular weight of the coalesce satisfies 10,000 or more and 1,000,000 or less.
• the polymer constituting the polymer particles is, for example, a monomer mixture composed of a plurality of types of (meth)acrylic acid ester monomers and radically polymerizable compounds other than (meth)acrylic acid ester monomers in an aqueous medium. It can be obtained by emulsion polymerization.
• the total (Y + Z) of the HSP polar component (Y) of the monomer and the HSP hydrogen bonding component (Z) of the monomer is 10 MPa 1/2 or less (meth)acrylic acid It preferably contains 80% by mass or more of structural units derived from the ester monomer (A).
• Structural unit derived from monomer (A) in which sum (Y+Z) of HSP polar component (Y) and HSP hydrogen bond component (Z) of (meth)acrylate monomer (A) is 10 MPa 1/2 or less is within the above range, it is possible to obtain polymer particles that are excellent in suppressing swelling in the electrolytic solution.
• the upper limit of the total (Y + Z) of the HSP polar component (Y) of the monomer (A) and the HSP hydrogen bonding component (Z) of the monomer (A) is preferably less than 10.0 MPa 1/2 , more preferably is 9.6 MPa 1/2 or less, more preferably 9.2 MPa 1/2 or less.
• the lower limit of the sum (Y+Z) of the HSP polar component (Y) of the monomer (A) and the HSP hydrogen bonding component (Z) of the monomer (A) is preferably 5 MPa 1/2 or more.
• HSP polar component (Y) and HSP hydrogen bond component (Z) of the (meth)acrylic acid ester monomer (A) were calculated using HSPiP (Hansen Solubility Parameter in Practice) ver. Use the numerical value described in the database of 5.2.05. For compounds with no numerical values in the database, the chemical structural formulas of the monomers are HSPiPver. Use the estimated value calculated according to 5.2.05.
• the upper limit of the content of the structural unit derived from the (meth)acrylate monomer (A) is preferably 100% by mass in 100% by mass of the structural units constituting the polymer. Below, it is more preferably less than 100% by mass, still more preferably 99% by mass or less, and particularly preferably less than 99% by mass.
• the lower limit of the content of structural units derived from the (meth)acrylate monomer (A) is preferably 80% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more, and still more preferably It is preferably 92% by mass or more, more preferably 95% by mass or more, and particularly preferably more than 98% by mass.
• (Meth) acrylate monomer (A) if the total (Y + Z) of the HSP polar component (Y) of the monomer and the HSP hydrogen bond component (Z) of the monomer is 10 MPa 1/2 or less , is not particularly limited.
• Preferred (meth)acrylic acid ester monomers (A) include, for example, fluorine-containing (meth)acrylic acid ester monomers, benzyl group or C 5-10 cyclic hydrocarbon group-containing (meth)acrylic acid ester monomers and polyfunctional monomers having two or more olefinic double bonds per molecule.
• the fluorine-containing (meth)acrylic acid ester monomer is preferably a hydrocarbon group having 1 to 10 carbon atoms in which the ester portion contains fluorine.
• fluorine-containing (meth)acrylic acid ester monomers include 2,2,2-trifluoroethyl acrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,3,3-pentafluoro Propyl acrylate, 2,2,3,3,3-pentafluoropropyl methacrylate and the like.
• the lower limit of the content of the structural unit derived from the fluorine-containing (meth)acrylic acid ester monomer is preferably 15% by weight in 100% by weight of the structural units constituting the polymer. Above, more preferably 20% by mass or more, still more preferably 25% by mass or more, and still more preferably 30% by mass or more.
• the upper limit of the content of the structural unit derived from the fluorine-containing (meth) acrylic acid ester monomer is preferably 60% by mass or less, more preferably 50% by mass or less in 100% by mass of the structural units constituting the polymer, It is more preferably 40% by mass or less, still more preferably 35% by mass or less.
• the (meth)acrylic acid ester monomer containing a benzyl group or a cyclic hydrocarbon group having 5 to 10 carbon atoms is preferably a benzyl group or a cyclic hydrocarbon group having 5 to 10 carbon atoms in its ester portion.
• Examples of the (meth)acrylic acid ester monomer containing a benzyl group or a cyclic hydrocarbon group having 5 to 10 carbon atoms include benzyl (meth)acrylate, cyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, and the like. mentioned.
• the lower limit of the content of structural units derived from a benzyl group or a cyclic hydrocarbon group-containing (meth) acrylic acid ester monomer having 5 to 10 carbon atoms is the structure constituting the polymerization Unit 100% by mass, preferably 50% by mass or more, more preferably 55% by mass or more, still more preferably 60% by mass or more, still more preferably 65% by mass or more, still more preferably 70% by mass or more, particularly preferably 75% by mass % or more.
• the upper limit of the content of structural units derived from a benzyl group or a cyclic hydrocarbon group-containing (meth) acrylic acid ester monomer having 5 to 10 carbon atoms is preferably 90 in 100% by mass of the structural units constituting the polymer. % by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, and even more preferably less than 80% by mass.
• polyfunctional monomers having two or more olefinic double bonds per molecule examples include allyl (meth)acrylate, ethylene di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate.
• acrylate tetraethylene glycol di(meth)acrylate, trimethylolpropane-tri(meth)acrylate, polyalkylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetra Methylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,12-dodecyldiol di(meth)acrylate, urethane acrylate, and the like.
• the lower limit of the content of structural units derived from polyfunctional monomers having two or more olefinic double bonds per molecule is 100 structural units constituting the polymer. In % by mass, preferably 0.5% by mass or more, more preferably 1% by mass or more, still more preferably 2% by mass or more, still more preferably 4% by mass or more, still more preferably 6% by mass or more, particularly preferably 10% by mass % or more.
• the upper limit of the content of structural units derived from a polyfunctional monomer having two or more olefinic double bonds per molecule is preferably 50% by mass or less in 100% by mass of the structural units constituting the polymer.
• polyfunctional monomer having two or more olefinic double bonds per molecule within the above range, it is possible to obtain polymer particles that are excellent in suppressing swelling in an electrolytic solution.
• the upper limit of the total (Y + Z) of the HSP polar component (Y) of the polyfunctional monomer having two or more olefinic double bonds per molecule and the HSP hydrogen bond component (Z) of the monomer is It is preferably 10 MPa 1/2 or less, more preferably 9 MPa 1/2 or less, still more preferably 8 MPa 1/2 or less.
• the lower limit of the sum (Y+Z) of the HSP polar component (Y) of the monomer and the HSP hydrogen bonding component (Z) of the monomer is preferably 5 MPa 1/2 or more.
• the total (Y + Z) of the HSP polar component (Y) of the polyfunctional monomer having two or more olefinic double bonds per molecule and the HSP hydrogen bond component (Z) of the monomer is within the above range. Thereby, it is possible to obtain polymer particles that are more excellent in suppressing swelling in the electrolytic solution.
• the content of the structural unit derived from the (meth)acrylic acid ester monomer (A) in the structural units constituting the polymer can be measured using a known method. For example, when measuring from a coated film, first, an organic solvent such as water or alcohol is used to remove the coating layer from the support, and the water and the organic solvent such as alcohol are sufficiently dried to obtain the coating layer. An organic solvent that dissolves the organic resin component is added to the obtained coat layer to dissolve only the organic resin component. Subsequently, the organic solvent is dried from the solution in which the organic resin component is dissolved, and only the organic resin component is extracted.
• an organic solvent such as water or alcohol
• An organic solvent that dissolves the organic resin component is added to the obtained coat layer to dissolve only the organic resin component.
• the organic solvent is dried from the solution in which the organic resin component is dissolved, and only the organic resin component is extracted.
• the volume average particle diameter of the polymer particles is preferably 100 nm or more and 500 nm or less.
• the volume average particle diameter of the polymer particles is preferably greater than 100 nm, more preferably 120 nm or more, and even more preferably 150 nm or more.
• the volume average particle diameter of the polymer particles is preferably less than 500 nm, more preferably 450 nm or less, and even more preferably 400 nm or less.
• volume-average particle size By setting the volume-average particle size to the above upper limit or less, the storage stability of the polymer particle dispersion can be improved, and the uniformity of the formed coating film can be improved.
• the volume average particle diameter of the polymer particles can be adjusted by changing the type of emulsifier and the monomer composition ratio during polymerization of the polymer particles.
• the particle size distribution (volume average particle size/number average particle size) of the polymer particles is preferably 1.5 or less, more preferably 1.4 or less, still more preferably 1.3 or less, still more preferably 1.2 or less, In addition, it is preferable that it is 1.1 or less. When the particle size distribution exceeds 1.5, it causes deterioration in the uniformity of the coating film containing the polymer particles.
• the particle size distribution of the polymer particles can be adjusted by changing the type of emulsifier, the monomer composition ratio and the polymerization conditions during polymerization of the polymer particles.
• the average particle size and particle size distribution of the polymer particles can be measured using a particle size distribution measuring device based on the principle of dynamic light scattering.
• a particle size distribution analyzer examples include HORIBA LB-550, SZ-100 series (manufactured by HORIBA, Ltd.), FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.), and the like.
• a dispersion can be prepared by mixing the polymer particles of the present invention with water.
• this dispersion can also contain inorganic particles such as alumina and titania.
• the pH of the dispersion is preferably 5.0-10.0, more preferably 6.0-9.5. Dispersion stability can be improved by adjusting the pH of the dispersion liquid within such a range.
• the dispersion containing the polymer particles of the present invention can modify the surface properties of the film by using it on the film, that is, by coating it on the film to form a coating film.
• the film is not particularly limited, and examples thereof include plastic films, metal films, paper, porous films, porous substrates, conductive films, and the like.
• the conditions for emulsion polymerization of the monomer mixture are not particularly limited.
• an emulsifier and a polymerization initiator preferably at a temperature of about 50 to 100° C. for about 1 to 30 hours. reaction should be performed.
• a chain transfer agent, a chelating agent, a pH adjuster, a solvent, etc. may be added as necessary.
• an anionic surfactant As the emulsifier, an anionic surfactant, a nonionic surfactant, a combination of an anionic surfactant and a nonionic surfactant, etc. are used.
• amphoteric or cationic surfactants can also be used.
• anionic surfactants include sodium alkyl sulfate, sodium alkylbenzene sulfonate, sodium dialkyl succinate sulfonate, sodium alkyldiphenyl ether disulfonate, sodium polyoxyethylene alkyl ether sulfate, and polyoxyethylene.
• Alkylphenyl ether sulfate sodium salt and the like can be mentioned.
• sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium lauryl sulfate and the like are preferable.
• nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and the like.
• Polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether and the like are generally used.
• amphoteric surfactants examples include lauryl betaine, hydroxyethylimidazoline sulfate sodium salt, imidazoline sulfonate sodium salt, and the like.
• cationic surfactants include alkylpyridinium chloride, alkyltrimethylammonium chloride, dialkyldimethylammonium chloride, and alkyldimethylbenzylammonium chloride.
• emulsifiers such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, perfluoroalkyl phosphates, perfluoroalkylpolyoxyethylenes, perfluoroalkylbetaines, and ammonium perfluoroalkoxyfluorocarboxylates can also be used as emulsifiers.
• Activators can also be used.
• reactive emulsifiers copolymerizable with the above monomers such as sodium styrenesulfonate, sodium allylalkylsulfonate, polyoxyethylene alkylallyl phenyl ether ammonium sulfate, polyoxyethylene alkyl allyl phenyl ether, etc.
• a combination of 2-(1-allyl)-4-nonylphenoxypolyethylene glycol sulfate ammonium salt and 2-(1-allyl)-4-nonylphenoxypolyethylene glycol is particularly preferred.
• the amount of emulsifier used is preferably 0.05 to 10 parts by mass per 100 parts by mass of the total amount of the monomer mixture.
• a water-soluble polymerization initiator such as sodium persulfate, potassium persulfate, ammonium persulfate, hydrogen peroxide, or a redox polymerization initiator that combines these water-soluble polymerization initiators with a reducing agent.
• potassium persulfate and ammonium persulfate are preferred.
• reducing agents include sodium pyrobisulfite, sodium hydrogensulfite, sodium sulfite, sodium thiosulfate, L-ascorbic acid or salts thereof, sodium formaldehyde sulfoxylate, ferrous sulfate, glucose and the like.
• L-ascorbic acid or salts thereof are preferred.
• an oil-soluble polymerization initiator can also be used by dissolving it in a monomer or solvent.
• the oil-soluble polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis-(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis -2,4-dimethylvaleronitrile, 1,1'-azobiscyclohexane-1-carbonitrile, 2,2'-azobisisovaleronitrile, 2,2'-azobisisocapronitrile, 2,2' -azobis(phenylisobutyronitrile), benzoyl peroxide, di-t-butyl peroxide, dilauroyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, t-butyl hydroperoxide , 3,5,5-trimethylhexanol peroxide, t-but
• the amount of polymerization initiator used is preferably 0.1 to 3 parts by mass per 100 parts by mass of the monomer mixture.
• chain transfer agents examples include halogenated hydrocarbons (eg, carbon tetrachloride, chloroform, bromoform, etc.), mercaptans (eg, n-dodecylmercaptan, t-dodecylmercaptan, n-octylmercaptan, n-hexadecylmercaptan, etc.), xanthogen.
• halogenated hydrocarbons eg, carbon tetrachloride, chloroform, bromoform, etc.
• mercaptans eg, n-dodecylmercaptan, t-dodecylmercaptan, n-octylmercaptan, n-hexadecylmercaptan, etc.
• xanthogen examples include xanthogenated hydrocarbons (eg, carbon tetrachloride, chloroform, bromoform, etc
• terpenes e.g., dipentene, terpinolene, etc.
• thiuram sulfides e.g., tetramethylthiuram monosulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethyl thiuram disulfide, etc.
• the amount of chain transfer agent used is preferably 0 to 10 parts by mass per 100 parts by mass of the monomer mixture.
• pH adjusters examples include sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and ammonia. Also, the amount of the pH adjuster used is preferably 0 to 3 parts by mass per 100 parts by mass of the monomer mixture.
• the monomer mixture can be added by various methods.
• a method of adding the entire amount of the monomer mixture at once a method of charging a part of the monomer mixture and reacting it, and then charging the remaining monomer mixture continuously or dividedly, a method of reacting
• a continuous or divided charging method is preferred.
• the polymer particles of the present invention can be preferably used as a binder for battery materials.
• a coating film on a separator film (battery separator film) of a lithium ion secondary battery it is possible to prepare a battery separator film having excellent wet adhesion to electrodes.
• the wet adhesion is the adhesion between the electrode and the battery separator film after the electrolyte is injected into the battery.
• a conventional battery material even if the adhesion between the electrode and the battery separator film before electrolyte injection is high, there is a problem that the adhesion after electrolyte injection decreases.
• the polymer particles of the present invention it is possible to produce a battery separator film with excellent wet adhesion to electrodes with high productivity.
• the battery separator film of the present invention is a battery separator film having a coating film containing polymer particles on a porous substrate, and the polymer particles are the polymer particles described above.
• the porous substrate has micropores inside and has a structure in which these micropores are connected from one surface to the other surface.
• the material constituting the porous substrate is preferably composed of a resin that is electrically insulating, electrically stable, and stable in the electrolytic solution. From the viewpoint of imparting a shutdown function, a thermoplastic resin having a melting point of 200° C. or less is preferable.
• the shutdown function is a function that, when the lithium ion secondary battery generates abnormal heat, closes the porous structure by melting with heat, stops the movement of ions, and stops discharge.
• thermoplastic resins examples include polyolefin resins.
• polyolefin-based resins include polyethylene, polypropylene, ethylene-propylene copolymers, and mixtures thereof.
• examples include single-layer porous substrates containing 90 mass% or more of polyethylene, polyethylene and a multi-layer porous substrate made of polypropylene.
• the thickness of the battery separator film is preferably 3 ⁇ m or more and 50 ⁇ m or less, more preferably 5 ⁇ m or more and 30 ⁇ m or less.
• the thickness of the battery separator film is preferably 3 ⁇ m or more and 50 ⁇ m or less, more preferably 5 ⁇ m or more and 30 ⁇ m or less.
• the air permeability of the battery separator film is preferably 50 sec/100 cc or more and 1,000 sec/100 cc or less. More preferably, it is 50 seconds/100 cc or more and 500 seconds/100 cc or less. Sufficient mechanical properties can be obtained by setting the air permeability to 50 sec/100 cc or more. In addition, by making it 1,000 seconds/100 cc or less, sufficient ion mobility is obtained, and battery characteristics are improved.
• a lithium-ion secondary battery has a structure in which a battery separator film and an electrolytic solution are interposed between the positive electrode and the negative electrode.
• the positive electrode is obtained by laminating a positive electrode material composed of an active material, a binder resin, and a conductive aid on a current collector.
• Active materials include layered lithium-containing transition metal oxides such as LiCoO 2 , LiNiO 2 and Li(NiCoMn)O 2 , spinel-type manganese oxides such as LiMn 2 O 4 , and iron-based compounds such as LiFePO 4 . etc.
• a resin having high oxidation resistance may be used as the binder resin. Specific examples include fluorine resins, acrylic resins, styrene-butadiene resins, and the like. Carbon materials such as carbon black and graphite are used as conductive aids.
• a metal foil is suitable, and an aluminum foil is often used in particular.
• the negative electrode is obtained by laminating a negative electrode material composed of an active material and a binder resin on a current collector.
• active materials include carbon materials such as artificial graphite, natural graphite, hard carbon and soft carbon, lithium alloy materials such as tin and silicon, metal materials such as Li, and lithium titanate (Li 4 Ti 5 O 12 ). is mentioned.
• a fluorine resin, an acrylic resin, a styrene-butadiene resin, or the like is used as the binder resin.
• metal foil is suitable, and copper foil is often used in particular.
• the electrolytic solution serves as a field for transferring ions between the positive electrode and the negative electrode in the secondary battery, and is made by dissolving the electrolyte in an organic solvent.
• the electrolyte include LiPF 6 , LiBF 4 , LiClO 4 and LiTFSI, and LiPF 6 is preferably used from the viewpoint of solubility in organic solvents and ionic conductivity.
• the organic solvent include ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate, etc. Two or more of these organic solvents may be used in combination.
• the polymer particles of the present invention can also be preferably used for battery materials other than battery separator films. Specifically, it can be suitably used as a binder resin for electrodes.
• the electrode is the positive electrode or the negative electrode of the lithium ion secondary battery. That is, the electrode of the present invention is an electrode in which a material containing a binder resin is laminated on a current collector, and the binder resin contains the polymer particles of the present invention.
• volume-average particle diameter, number-average particle diameter, and particle size distribution of polymer particles manufactured by the same company
• analyzed by the Marquardt Method to calculate the volume average particle size and the number average particle size.
• the particle size distribution was obtained from the obtained values.
• HSP polar component (X) of particle film made of polymer particles The particle film made of polymer particles is obtained by molding polymer particles into a sheet having a thickness of about 1 to 2 mm by hot pressing. A solvent swelling test was performed. About 70 to 90 mg of a test piece obtained by cutting a particle film made of polymer particles into several mm squares was added to about 2 mL of each of the following 24 types of test solvents (n-hexane, N,N-dimethylformamide, cyclohexane, ⁇ -butyrolactone, Methyl isobutyl ketone, ethanol, n-butyl acetate, dimethyl sulfoxide, toluene, methanol, tetrahydrofuran, 2-aminoethanol, methyl ethyl ketone, cyclohexanone, chloroform, methyl acetate, acetone, 1,4-dioxane, pyridine, N-methylpyrrolidone
• a particle film consisting of polymer particles is formed by heating and pressing polymer particles into a sheet having a thickness of about 1 to 2 mm.
• a sample was immersed in an electrolytic solution using a particle film made of polymer particles, and the degree of swelling was determined from the weight increase due to the swelling of the sample.
• the weight WW of the sample piece was weighed.
• the degree of swelling S was obtained from the following formula.
• VD and VW are the volumes of the test piece before and after solvent immersion, respectively, and were obtained from the following equations.
• ⁇ S is the density of the polymer composing the test piece
• ⁇ L is the density of the electrolyte used in the test.
• HSP polar component (Y) and HSP hydrogen bond component (Z) of (meth)acrylate monomer Calculation software HSPiP (Hansen Solubility Parameter in Practice) ver. 5.2.05 The numerical value described in the database was used. For compounds with no numerical values in the database, the chemical structural formulas of the monomers are HSPiPver. The estimated value calculated according to 5.2.05 was used.
• an electrode having a width of 20 mm and a length of 70 mm was obtained.
• This electrode is used as the negative electrode of a lithium ion secondary battery.
• the porous film and the electrode are arranged so that the ends of the electrode and the porous film in the length direction are aligned and overlapped, and the active material of the electrode and the porous layer of the porous film are in contact. Then, hot pressing was performed under the conditions of 80° C., 5 MPa, and 7 seconds to adhere the electrode and the porous film to prepare a test piece.
• the test piece is placed in a bag-shaped aluminum laminate film with three pieces closed, and 1 g of the electrolytic solution is impregnated from the porous film side of the test piece, and then the remaining one side of the aluminum laminate film is used with a vacuum sealer. was closed to encapsulate the specimen.
• the aluminum laminate film after enclosing this test piece was stored in a 60° C. environment for 17 hours under static conditions.
• the test piece was taken out from the aluminum laminate film, the electrolytic solution on the surface of the test piece was wiped off, and the electrode side of the test piece was attached to an acrylic plate having a thickness of 2 mm. Thereafter, the porous film was peeled off in the direction of 180°, and the adhesion was evaluated as "excellent”, “good”, “slightly inferior”, and “poor” based on the degree of peeling. "Excellent”: Exhibited extremely good adhesiveness. "Good”: Sufficient adhesiveness was exhibited. “Slightly inferior”: Adhesion was insufficient. "Inferior”: There was no adhesiveness.
• Example 1 120 parts of ion-exchanged water and 1 part of Adekaria Sorb SR-1025 (an emulsifier manufactured by Adeka Corporation) were charged into a reactor, and stirring was started. 0.4 part of 2,2′-azobis(2-(2-imidazolin-2-yl)propane) (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the reactor under a nitrogen atmosphere.
• Example 2 120 parts of ion-exchanged water and 1 part of Adekaria Sorb SR-1025 (an emulsifier manufactured by Adeka Corporation) were charged into a reactor, and stirring was started. 0.4 part of 2,2′-azobis(2-(2-imidazolin-2-yl)propane) (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the reactor under a nitrogen atmosphere.
• Example 3 Polymer particles were obtained in the same manner as in Example 2, except that the composition ratio of the monomer mixture was changed to the composition shown in Table 1. The obtained polymer particles were as shown in Table 1.
• Example 4 120 parts of ion-exchanged water and 1 part of Adekaria Sorb SR-1025 (an emulsifier manufactured by Adeka Corporation) were charged into a reactor, and stirring was started. 0.4 part of 2,2′-azobis(2-(2-imidazolin-2-yl)propane) (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the reactor under a nitrogen atmosphere.
• Examples 5-14, Comparative Examples 1-4 Polymer particles were obtained in the same manner as in Example 4, except that the composition ratio of the monomer mixture was changed to the composition shown in Table 1 or 2. The obtained polymer particles were as shown in Table 1 or 2.
• composition ratio of the monomers shown in Tables 1 and 2 is the ratio of each component when the total amount of the monomer components is 100 parts by mass.
• abbreviations of each component in Table 1 have the following meanings.
• 3FMA 2,2,2-trifluoroethyl methacrylate (in formula (1), R 1 : —CH 3 , R 2 : —CH 2 CF 3 , a is the degree of polymerization)
• CHA cyclohexyl acrylate (in formula (1), R 1 : —H, R 2 : cyclohexyl group, a is degree of polymerization)
• MMA methyl methacrylate
• BA n-butyl acrylate 4HBA: 4-hydroxybutyl acrylate (wherein R 1 : -H, R 2 : 4-hydroxybutyl group, a is the degree of polymerization)
• the polymer particles of the present invention are preferably used as a binder for battery materials.
• a battery separator film battery separator film

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• 2022
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