JP4957871B2 - Crosslinked polymer particles and method for producing the same - Google Patents

Description

  The present invention relates to crosslinked polymer particles and a method for producing the same.

  Crosslinked polymer particles with a high degree of crosslinking and excellent heat resistance and chemical resistance include various spacers, electrical and electronic materials such as conductive fine particles, resin film sliding property modifiers, chromatography carriers, It is applied and put into practical use in various fields such as biomedical devices. Generally, these crosslinked polymer particles are produced by a method such as a suspension polymerization method, an emulsion polymerization method, a seed polymerization method and a dispersion polymerization method.

  In suspension polymerization, cross-linked polymer particles can be produced by polymerizing a cross-linkable monomer as oil droplets in an aqueous medium by mechanical force.

  In the case of emulsion polymerization, generally, the upper limit of the ratio of the crosslinkable monomer is about 2.0% by mass. Moreover, the range of the particle diameter of the obtained crosslinked polymer particles is 0.1 to 1.0 μm, and it is said that particles having a particle diameter exceeding 1 μm cannot be obtained. Patent Document 1 discloses a method in which emulsion polymerization can be stably performed by using a special seed, even when 20.0% by mass or more of a crosslinkable monomer is used. However, the range of the particle diameter obtained by this method is 0.1 to 1.0 μm, which is the same as that of ordinary emulsion polymerization. Thus, it is difficult to obtain crosslinked polymer particles having a particle diameter exceeding 1 μm by emulsion polymerization.

  Patent Document 2 discloses a first step in which an organic compound having low solubility in water is absorbed into a seed polymer as a swelling aid, and then a monomer soluble in water to some extent is absorbed into the seed polymer to form monomer swelling particles. Through the second stage, a swelling polymerization method is disclosed in which a monomer is polymerized while maintaining the particle shape. According to this method, it becomes possible to use many crosslinkable monomers, and as a result, crosslinked polymer particles having a size of 1 μm or more and a uniform particle size distribution can be produced. However, since the solubility of the swelling aid used in this method in water is extremely low, there is a drawback that it takes a long time in the first stage of absorbing the swelling aid into the seed polymer. In addition, oil droplets that remain without being absorbed by the seed polymer may form coarse particles after polymerization.

  Patent Document 3 discloses a method for producing crosslinked particles by a dispersion polymerization method using 20% by mass or more of a crosslinkable vinyl monomer. According to this method, it is possible to produce monodisperse particles of about several microns to some extent. However, when the particle diameter exceeds 2.5 μm, the aggregation and fusion of the particles increases, and it is very difficult to obtain monodisperse particles. Moreover, when a hydrophilic or water-soluble polymerizable monomer is copolymerized, it is more difficult to obtain monodisperse particles because aggregation and fusion are likely to occur.

  In Patent Document 4, a crosslinked polymer particle is produced by copolymerizing an unsaturated monomer having a hydrophilic functional group or an active hydrogen group with a crosslinkable monomer when performing a precipitation polymerization method similar to the dispersion polymerization method. A method has been reported. According to this method, monodisperse particles of several μm can be obtained efficiently.

  Patent Document 5 reports a method of crosslinking a mother particle by reacting an uncrosslinked mother particle having a functional group with an epoxy compound, an oxazoline compound, or an amino compound. According to this method, although it is possible to crosslink uncrosslinked particles, since the reactivity of the compound to be reacted is high, the crosslinking reaction tends to proceed mainly on the particle surface and a core-shell structure tends to be formed.

JP-A-1-315454 JP 54-126288 A JP-A-6-122703 JP 2006-282774 A Japanese Patent No. 4215521

Journal of Polymer Science. Part A: Polymer Chemistry, (USA), 31, 3257 (1993)

  According to the conventional method, for example, when the mother particle contains a functional group derived from a hydrophilic monomer on the surface and inside of the particle, a sufficient level is achieved in terms of compression characteristics such as compression deformation recovery rate and compression fracture strength. It was difficult to obtain polymer particles. For example, when polymer particles are covered with a metal layer to form conductive particles that are used in an anisotropic conductive adhesive, it is extremely important that the polymer particles have good compression properties. Furthermore, simultaneously with compression characteristics, when forming a metal plating layer on the surface of polymer particles by plating, it is required to form a plating layer having high uniformity and good adhesion. However, when there is no functional group derived from a hydrophilic monomer on the particle surface, it has been difficult in the past to obtain polymer particles having excellent compression characteristics and sufficiently excellent plating formability.

  Accordingly, a main object of the present invention is to provide polymer particles that have good compression characteristics and can form a plating layer in a good state on the surface thereof.

  The present invention includes a step of bringing a mother particle formed from a crosslinked polymer having a functional group into contact with an amino compound having two or more amino groups, and further crosslinking the crosslinked polymer by a reaction between the functional group and the amino group. The present invention relates to a crosslinked polymer particle obtainable by a production method comprising (a). The amino compound includes a low molecular weight amino compound having a molecular weight of less than 500.

  The crosslinked polymer particles according to the present invention have good compression characteristics and can form a plating layer on the surface in a good state. By using a low molecular weight amino compound having a molecular weight of less than 500, the inside of the mother particle can be efficiently cross-linked, and the compression characteristics can be improved. As exemplified by particles synthesized by precipitation polymerization, mother particles obtained by copolymerizing a hydrophilic monomer generally tend to have low compression characteristics due to a small amount of the crosslinkable monomer. Cross-linked polymer with good compression characteristics and good plating formability by post-crosslinking mother particles having functional groups such as carboxyl groups derived from hydrophilic monomers with compounds having two or more amino groups Particles can be obtained.

  The amino compound preferably further contains a high molecular weight amino compound having a molecular weight of 500 to 10,000. By using together a high molecular weight amino compound having a molecular weight of 500 to 10,000, it is possible to introduce a large number of amino groups on the surface of the mother particle, and to further improve the formability of plating.

  The average particle size of the crosslinked polymer particles is preferably 0.1 to 10 μm. The Cv value of the particle diameter of the crosslinked polymer particles is preferably 10% or less. When the Cv value of the particle diameter of the crosslinked polymer particles is low, the connection reliability when the conductive particles obtained from the crosslinked polymer particles are used for the anisotropic conductive adhesive is further improved.

  The crosslinked polymer forming the mother particle preferably has at least one functional group selected from the group consisting of a carboxyl group, an epoxy group, and a glycidyl group. These functional groups efficiently react with the amino group of the amino compound, and a crosslinked structure is formed in the mother particle.

  The mother particles are preferably particles that can be obtained by suspension polymerization, emulsion polymerization, dispersion polymerization, precipitation polymerization or seed polymerization.

  The crosslinked polymer forming the mother particle is preferably a copolymer formed by copolymerizing a monomer mixture containing 10% by mass or more of a monomer having two or more unsaturated double bonds. . Thereby, the compression characteristic of a crosslinked polymer particle can be improved especially effectively. The monomer having two or more unsaturated double bonds preferably contains at least one selected from divinylbenzene and di (meth) acrylate.

  The mother particles after the step (a) preferably have a compression deformation recovery rate of 40% or more and a compression fracture strength of 10 mN or more at 180 ° C.

  The present invention also relates to conductive particles that can be obtained by a production method including the step (c) of plating the crosslinked polymer particles according to the present invention. The conductive particles according to the present invention are useful, for example, as conductive particles for anisotropic conductive adhesives.

  In the step (c), the crosslinked polymer particles are preferably plated using a Pd ion complex as a plating catalyst.

  In another aspect, the present invention relates to a method for producing crosslinked polymer particles. In the production method according to the present invention, a mother particle formed from a cross-linked polymer having a functional group is brought into contact with an amino compound having two or more amino groups, and the cross-linked polymer is formed by a reaction between the functional group and the amino group. Furthermore, a cross-linking step (a) is provided. The amino compound includes a low molecular weight amino compound having a molecular weight of less than 500.

  According to the method of the present invention, it is possible to obtain crosslinked polymer particles having good compression characteristics and capable of forming a plating layer in a good state on the surface thereof.

  In the step (a), the amino group ratio of the amino compound is preferably 0.1 to 5 equivalents relative to 1 equivalent of the functional group in the mother particle. By treating the mother particles with the amino compound in these ratios, crosslinked polymer particles having particularly excellent compression characteristics and plating formability can be obtained.

  The present invention also relates to an anisotropic conductive adhesive comprising a binder resin and the conductive particles dispersed in the binder resin.

  ADVANTAGE OF THE INVENTION According to this invention, while having a favorable compression characteristic, the polymer particle which can form a plating layer in the favorable state on the surface is provided.

It is a schematic diagram which shows one Embodiment of a crosslinked polymer particle. It is sectional drawing which shows one Embodiment of an anisotropic conductive adhesive.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  The crosslinked polymer particle according to the present embodiment comprises a step of preparing a mother particle formed from a crosslinked polymer having a functional group, and bringing the mother particle into contact with an amino compound having two or more amino groups. And a step (a) of further crosslinking the crosslinked polymer by a reaction between the amino group and the amino group.

  FIG. 1 is a schematic view showing an embodiment of a crosslinked polymer particle. A crosslinked polymer particle 1 shown in FIG. 1 includes a mother particle 10, a mother particle 10 that is a particulate crosslinked polymer, a crosslinked portion X derived from an amino compound that crosslinks the crosslinked polymer, and an amino group derived from the amino compound. The modification part R has. The cross-linked portion X is distributed over the entire surface and inside of the base particle 10. The modified portion R is mainly disposed on the surface of the base particle 10.

  The cross-linked polymer constituting the mother particle 10 is, for example, a styrene resin, an acrylic resin, a methacrylic resin, a polyethylene resin, a polypropylene resin, a silicone resin, a polyester resin, a polyurethane resin, a polyamide resin, or an epoxy resin. A resin, a polyvinyl butyral resin, a rosin resin, a terpene resin, a phenol resin, a melamine resin, a guanamine resin, an oxazoline resin, a carbodiimide resin, and a cured resin obtained by crosslinking these. These can be used alone or in combination of two or more. Functional groups that react with amino compounds (carboxyl group, epoxy group, glycidyl group, etc.) are introduced into these polymers.

  The mother particle 10 is preferably a crosslinked polymer particle formed by copolymerization of a monomer mixture composed of a plurality of types of monomers having an unsaturated double bond. The monomer mixture is, for example, at least one hydrophilic functional group selected from the group consisting of a multifunctional monomer having two or more unsaturated double bonds, a carboxyl group, an epoxy group, and a glycidyl group. And a monomer having

  The monomer mixture preferably contains 10% by mass or more of a polyfunctional monomer having two or more unsaturated double bonds with respect to the whole monomer mixture. As a result, crosslinked polymer particles having a high compression deformation recovery rate are particularly easily formed. When the compression deformation recovery rate of the crosslinked polymer particles is high, when the crosslinked polymer particles are used as the polymer particles constituting the conductive particles of the anisotropic conductive adhesive, an increase in connection resistance with time is suppressed, Higher connection reliability is achieved. From such a viewpoint, the monomer mixture is preferably a polyfunctional monomer having two or more unsaturated double bonds, more preferably 10 to 80% by mass, still more preferably 10 to 60% by mass, and much more. Preferably it contains 10-50 mass%.

  The mother particle 10 is preferably obtained by a method of performing solution polymerization in a medium in which the monomer mixture is dissolved and the resulting crosslinked polymer is not substantially dissolved. It is also possible to form a crosslinked polymer in the absence of a solvent as in bulk polymerization.

  Solution polymerization includes (1) emulsion or suspension polymerization performed in an aqueous solution, (2) dispersion polymerization performed in the presence of a dispersant in a non-aqueous organic solvent or a mixed solvent of water and a non-aqueous organic solvent, ( 3) A method of combining the above (1) or (2) with a seed polymerization method may be mentioned.

  A copolymer having a hydrophilic functional group as well as a desired micron-size particle can be obtained without using a seed particle. Precipitation polymerization is preferably employed because, for example, it is possible to easily produce particles with excellent deformation recovery rate at high compression displacement.

  The monomer having two or more unsaturated double bonds is not particularly limited, and is appropriately selected from, for example, commonly used polyfunctional vinyl monomers and polyfunctional (meth) acrylic acid esters. The

  Specific examples of the polyfunctional monomer include divinylbenzene; divinylbiphenyl; divinylnaphthalene; (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and (poly) tetramethylene glycol di (Poly) alkylene glycol-based di (meth) acrylates such as (meth) acrylate; 1,6-hexanediol di (meth) acrylate, 1,8-octanediol di (meth) acrylate, 1,9-nonanediol di ( (Meth) acrylate, 1,10-decanediol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 2,4-diethyl- 1,5-pentanediol di (meth) acrylate Alkanediol type di (meth), such as butylethylpropanediol di (meth) acrylate, 3-methyl-1,7-octanediol di (meth) acrylate, 2-methyl-1,8-octanediol di (meth) acrylate ) Acrylate; neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, ethoxylated cyclohexane Dimethanol di (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, propoxylated ethoxylated bisphenol A di (me ) Acrylate, 1,1,1-trishydroxymethylethane di (meth) acrylate, 1,1,1-trishydroxymethylethane tri (meth) acrylate, 1,1,1-trishydroxymethylpropane triacrylate, diallyl phthalate And isomers thereof, triallyl isocyanurate and derivatives thereof. Commercially available polyfunctional monomers include NK esters (A-TMPT-6P0, A-TMPT-3E0, A-TMM-3LMN, A-GLY series, manufactured by Shin-Nakamura Chemical Co., Ltd., A-9300, AD-TMP, AD-TMP-4CL, ATM-4E, A-DPH) and the like. These monomers may be used alone or in combination of two or more.

  Among these, it is preferable that a polyfunctional monomer contains at least 1 sort (s) chosen from divinylbenzene and polyfunctional (meth) acrylic acid ester. By using these monomers, the compression deformation recovery rate of the obtained crosslinked polymer particles can be more easily increased. From the same viewpoint, the polyfunctional monomer preferably contains di (meth) acrylic acid ester, and more preferably alkanediol di (meth) acrylate. The carbon number of the alkanediol is preferably 6 to 18 carbon atoms, more preferably 8 to 12 carbon atoms.

  Examples of the radical polymerizable monomer having a carboxyl group include various unsaturated mono- or dicarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, monobutyl itaconate and monobutyl maleate. An acid or an unsaturated dibasic acid is mentioned. These may be used alone or in combination of two or more.

  Examples of the radical polymerizable monomer having an epoxy group include glycidyl (meth) acrylate, (β-methyl) glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, allyl glycidyl ether, 3,4- It is selected from epoxy vinylcyclohexane, di (β-methyl) glycidyl malate and di (β-methyl) glycidyl fumarate.

  You may introduce | transduce an epoxy group in a crosslinked polymer using the compound which has another epoxy group. Examples of the compound having an epoxy group include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, hexamethylene glycol diglycidyl ether, cyclohexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether. Glycidyl ethers of aliphatic polyhydric alcohols such as, glycidyl ethers of polyalkylene glycols such as polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether and polytetramethylene glycol diglycidyl ether, polyglycidylated polyester resins, polyamides Resin-based polyglycidyl compounds, bisphenol A series of epoxy resins, phenol novolak-based epoxy resins, as well as epoxy urethane resin. These may be used alone or in combination of two or more.

  The monomer mixture may contain a monofunctional monomer having one unsaturated double bond. The proportion of this monofunctional monomer is preferably 0 to 70% by mass of the entire monomer mixture. The ratio of the monofunctional monomer is more preferably 5 to 70% by mass, further preferably 10 to 70% by mass, and still more preferably 15 to 70% by mass.

  Examples of the monofunctional monomer include (i) styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene. 2,4-dimethylstyrene, pn-butylstyrene, pt-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, styrene or derivatives thereof such as pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, (ii) methyl acrylate, ethyl acrylate, propyl acrylate, N-butyl acrylate, isobutyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, acrylic N-octyl acrylate, dodecyl acrylate, lauryl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n methacrylate -(Meth) acrylic acid esters such as butyl, isobutyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, stearyl methacrylate, (iii) vinyl acetate, propion Vinyl esters such as vinyl acid vinyl, vinyl benzoate and vinyl butyrate, (iv) N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, (v) vinyl fluoride Examples include fluorinated alkyl group-containing (meth) acrylates such as vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, trifluoroethyl acrylate, and tetrafluoropropyl acrylate, and (vi) conjugated dienes such as butadiene and isoprene. . These are used individually by 1 type or in combination of 2 or more types.

  Among these, styrene or a derivative thereof, (meth) acrylic acid ester, and vinyl ester are preferable. By using these, mother particles having the above-described physical properties can be obtained efficiently.

  A known radical polymerization initiator can be used as the polymerization initiator used in radical polymerization for producing the mother particles. Specific examples of the radical polymerization initiator include benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, peroxides such as sodium persulfate and ammonium persulfate, azobisisobutyronitrile, azobismethylbutyro Examples thereof include azo compounds such as nitrile and azobisisovaleronitrile. These may be used alone or in combination of two or more.

  Specific examples of the polymerization solvent used when producing the mother particles by solution polymerization include water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1 -Pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl-2- Alcohols such as pentanol, 2-ethylbutanol, 1-heptanol, 2-heptanol, 3-heptanol, 2-octanol, 2-ethyl-1-hexanol, benzyl alcohol, cyclohexanol; methyl cellosolve, ethyl cellosolve, isopropyl cellosolve Ether alcohols such as butyl cellosolve and diethylene glycol monobutyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethyl acetate, butyl acetate, ethyl propionate, (alkyl) cellosolve acetate, ethyl carbitol acetate, butyl carbitol acetate Esters such as pentane, 2-methylbutane, n-hexane, cyclohexane, 2-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane, n-octane, isooctane, 2,2,3- Trimethylpentane, decane, nonane, cyclopentane, methylcyclopentane, methylcyclohexane, ethylcyclohexane, p-menthane, dicyclohexyl, benzene, toluene, Aliphatic or aromatic hydrocarbons such as silene and ethylbenzene; Halogenated hydrocarbons such as carbon tetrachloride, trichloroethylene, chlorobenzene and tetrabromoethane; Ethers such as ethyl ether, dimethyl ether, trioxane and tetrahydrofuran; Methylal and diethyl acetal Acetals such as: fatty acids such as formic acid, acetic acid, propionic acid; sulfur, nitrogen such as nitropropene, nitrobenzene, dimethylamine, monoethanolamine, pyridine, dimethylformamide, dimethylsulfoxide, acetonitrile, N-methyl-2-pyrrolidone Examples thereof include organic compounds. These can be used alone or in combination of two or more. Among these, acetonitrile is preferable from the viewpoint of preventing particle aggregation.

  In producing the mother particles, a dispersant, a stabilizer, an emulsifier, a surfactant and the like may be appropriately selected and used.

  Examples of the dispersant and stabilizer include polyhydroxystyrene, polystyrene sulfonic acid, vinylphenol- (meth) acrylic acid ester copolymer, styrene- (meth) acrylic acid ester copolymer, styrene-vinylphenol- (meth) acrylic. Polystyrene derivatives such as acid ester copolymers; poly (meth) acrylic acid derivatives such as poly (meth) acrylic acid, poly (meth) acrylamide, polyacrylonitrile, pothiethyl (meth) acrylate, polybutyl (meth) acrylate; polymethyl vinyl ether , Polyvinyl alkyl ether derivatives such as polyethyl vinyl ether, polybutyl vinyl ether, polyisobutyl vinyl ether; cellulose, methyl cellulose, cellulose acetate, cellulose nitrate, hydroxymethyl cellulose, Cellulose derivatives such as roxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose; polyvinyl acetate derivatives such as polyvinyl alcohol, polyvinyl butyral, polyvinyl formal, polyvinyl acetate; polyvinyl pyridine, polyvinyl pyrrolidone, polyethyleneimine, poly-2-methyl-2- Various hydrophobic or hydrophilic dispersants and stabilizers such as nitrogen-containing polymer derivatives such as oxazoline; polyhalogenated vinyl derivatives such as polyvinyl chloride and polyvinylidene chloride; and polysiloxane derivatives such as polydimethylsiloxane. These may be used alone or in combination of two or more.

  Examples of emulsifiers (surfactants) include alkyl sulfate salts such as sodium lauryl sulfate, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, alkylnaphthalene sulfonates, fatty acid salts, alkyl phosphates, and alkylsulfosuccinates. Anionic emulsifiers; Cationic emulsifiers such as alkylamine salts, quaternary ammonium salts, alkylbetaines, amine oxides; polyoxyethylene alkyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene alkylphenyls Nonionic emulsifiers such as ether, sorbitan fatty acid ester, glycerin fatty acid ester, and polyoxyethylene fatty acid ester are listed. These may be used alone or in combination of two or more.

  In the step (a), for example, the mother particle is brought into contact with a solution containing an amino compound and a solvent in which the amino compound is dissolved, and the crosslinked polymer is further crosslinked by the reaction between the functional group and the amino group in the mother particle. The solution of the amino compound is impregnated only in the surface layer portion or the inner region of the mother particle.

  As the amino compound, one or more compounds having two or more amino groups are used. From the viewpoint of improving the formability of plating, compounds having a large amount of primary or secondary amines such as polyethyleneimine and pentaethylenehexamine are preferable.

  The amino compound preferably contains a low molecular weight amino compound having a molecular weight of less than 500 from the viewpoint of improving compression characteristics. Further, the amino compound preferably contains a high molecular weight amino compound having a molecular weight of 500 to 10,000 in order to improve the formability of plating. It is particularly preferable to use a low molecular weight amino compound and a high molecular weight amino compound in combination. The molecular weight of the low molecular weight amino compound is preferably 50 or more and less than 500, more preferably 50 to 400, and still more preferably 50 to 300. The molecular weight of the high molecular weight amino compound is preferably 500 to 10,000, more preferably 500 to 5,000.

  The amino compound is preferably an aliphatic diamine having a linear or alkyl side chain. Specific examples of the aliphatic diamine include ethylenediamine, propylenediamine, 1,4-butanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,9-nonanediamine, 2-methyl-1,8-octane. Diamine, 1,10-decanediamine, 1,12-dodecanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl- There are 1,6-hexanediamine and 5-methyl-1,9-nonanediamine.

  The amino compound may contain an alicyclic diamine and / or an aromatic diamine. Alicyclic diamines include cyclohexane diamine, methyl cyclohexane diamine, and isophorone diamine. Aromatic diamines include p-phenylene diamine, m-phenylene diamine, xylene diamine, 4,4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl sulfone and 4,4'-diaminodiphenyl ether.

  Among the above amino compounds, those having a molecular weight of less than 500 can be used as the low molecular weight amino compound.

  The amino compound may contain polyamines such as triamine and tetraamine in addition to the diamine. High molecular weight polyethyleneimine is suitable as a high molecular weight amino compound.

  These amino compounds are used alone or in combination of two or more. The reaction between the mother particle and two or more kinds of amino compounds can be carried out all at once, or each amino compound can be added stepwise to advance the reaction.

  The amino compound may be dissolved in an organic solvent. Typical examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate, butyl acetate, ethyl propionate, and cellosolve acetate; pentane, 2-methylbutane, n-hexane, Cyclohexane, 2-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane, n-octane, isooctane, 2,2,3-trimethylpentane, decane, nonane, cyclopentane, methylcyclopentane, methyl Aliphatic or aromatic hydrocarbons such as cyclohexane, ethylcyclohexane, p-menthane, benzene, toluene, xylene and ethylbenzene; halogenated hydrocarbons such as carbon tetrachloride, trichloroethylene, chlorobenzene and tetrabromoethane Ethers such as ethyl ether, dimethyl ether, trioxane and tetrahydrofuran; acetals such as methylal and diethyl acetal; sulfur and nitrogen-containing organic compounds such as nitropropene, nitrobenzene, pyridine, dimethylformamide, dimethyl sulfoxide and acetonitrile; . These may be used alone or in combination of two or more.

  If the amino compound is a water-soluble or hydrophilic organic compound, in addition to the above organic solvent, water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl- Alcohols such as 2-pentanol, 2-ethylbutanol, 1-heptanol, 2-heptanol, 3-heptanol, 2-octanol, 2-ethyl-1-hexanol, benzyl alcohol, cyclohexanol; methyl cellosolve, ethyl cellosolve, Isopropyl cellosol , Butyl cellosolve, ether alcohols such as diethylene glycol monobutyl ether can also be used. These may be used alone or in combination of two or more.

  The reaction solvent for reacting the functional group in the mother particle with the amino group is preferably a solvent in which the mother particle is not substantially dissolved and the amino compound is dissolved. When the amino compound is liquid, the reaction between the functional group in the mother particle and the amino compound may be performed in the absence of a solvent.

  Examples of the reaction solvent include alcohols such as γ-butyrolactone, glycerin, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and n-butanol. , Hydrocarbons such as toluene, xylene, n-octane, n-dodecane, fatty acids such as linoleic acid, polyethylene glycol, dimethyl silicone, water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2 -Butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 1-hexanol, 2-methyl -1-pentanol, -Alcohols such as methyl-2-pentanol, 2-ethylbutanol, 1-heptanol, 2-heptanol, 3-heptanol, 2-octanol, 2-ethyl-1-hexanol, benzyl alcohol, cyclohexanol; methyl cellosolve, Ether alcohols such as ethyl cellosolve, isopropyl cellosolve, butyl cellosolve, diethylene bricol monobutyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; esters such as ethyl acetate, butyl acetate, ethyl propionate, cellosolve acetate; Pentane, 2-methylbutane, n-hexane, cyclohexane, 2-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane, n-octane, i Aliphatic or aromatic hydrocarbons such as sooctane, 2,2,3-trimethylpentane, decane, nonane, cyclopentane, methylcyclopentane, methylcyclohexane, ethylcyclohexane, p-menthane, dicyclohexyl, benzene, toluene, xylene, ethylbenzene Halogenated hydrocarbons such as carbon tetrachloride, trichloroethylene, chlorobenzene and tetrabromoethane; Ethers such as ethyl ether, dimethyl ether, trioxane and tetrahydrofuran; Acetals such as methylal and diethyl acetal; Formic acid, acetic acid and propionic acid Fatty acids such as: nitropropene, nitrobenzene, dimethylamine, monoethanolamine, pyridine, dimethylformamide, dimethylsulfoxide, and other sulfur and nitrogen-containing organic compounds It is below. Preferably, water, a lower alcohol such as methanol or ethanol, an ether alcohol such as methyl cellosolve or ethyl cellosolve, a mixture of water and lower alcohol, a water-soluble and hydrophilic medium such as a mixture of water and ether alcohol, toluene, dimethyl Examples include formamide (DMF), tetrahydrofuran (THF), methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), acetone, N-methyl-2-pyrrolidone (NMP), dichloromethane, tetrachloroethylene, and more preferably water, methanol. Or a lower alcohol such as ethanol, a mixture of water and a lower alcohol such as methanol or ethanol, a mixture of water and a lower alcohol such as methanol or ethanol, or a mixture of water and ether alcohol. A water-soluble and hydrophilic media. These may be used alone or in combination of two or more.

  The temperature at which the amino compound is reacted in step (a) depends on the type of solvent, but is preferably 10 ° C to 250 ° C, more preferably 100 to 250 ° C, and even more preferably 180 ° C to 250 ° C. The reaction time may be the time required for the crosslinking reaction to be almost completed, and greatly depends on the amino compound used and the amount added, the type of functional group in the mother particle, the viscosity and concentration of the solution, etc. It is about 5 to 24 hours at 180 ° C., preferably about 6 to 10 hours. Even if the reaction time is lengthened, crosslinked polymer particles can be obtained, but it is not a good practice to take a long time in practice. Moreover, when reaction time is extremely short, bridge | crosslinking may not fully advance.

  The amount of the amino compound in the step (a) is preferably 0.1 to 5, more preferably 0.5 to 3 in terms of an equivalent ratio of amino groups to functional groups of the mother particles. If this equivalent ratio is too small or excessively large, the effect of improving the compression characteristics and improving the formability of plating tends to be reduced.

  The average particle diameter of the crosslinked polymer particles is preferably 0.1 to 50 μm, more preferably 0.2 to 30 μm, still more preferably 0.3 to 20 μm, and most preferably 0.5 to 5 μm. If the average particle size is small, the crosslinked polymer particles may easily aggregate.

  The Cv value (coefficient of variation) of the particle diameter (diameter) of the crosslinked polymer is preferably 15% or less. When the Cv value exceeds 15%, the performance of the crosslinked polymer particles in various uses tends to be lowered. For example, the connection reliability when the crosslinked polymer particles are used for conductive particles constituting an anisotropic conductive adhesive is reduced, and the quantitativeness when the crosslinked polymer particles are used for a biopsy element is reduced. There is a tendency to. From the same viewpoint, the Cv value of the particle diameter is preferably 10% or less, more preferably 5% or less, and still more preferably 4% or less.

The average particle diameter and the Cv value of the particle diameter of the crosslinked polymer particles are determined by the following measurement method. 1) Disperse particles in water using an ultrasonic dispersion facility to prepare a dispersion containing 1% by mass of particles.
2) About 20,000 dispersions are observed with a particle size distribution meter (Sysmex Flow, manufactured by Sysmex) under a microscope, and the average particle size and the coefficient of variation Cv of the particle size are calculated.

  The compression deformation recovery rate measured at 180 ° C. of the mother particles after the step (a) is usually 30% or more, preferably 40% or more, more preferably 50% or more, and further preferably 50 to 65%. It is. If this compression deformation recovery rate is low, the elastic force is insufficient, and there is a tendency that poor contact is likely to occur in applications such as anisotropic conductive adhesives that require high elasticity.

  The compression deformation recovery rate is the relationship between the load value and the compression displacement in the process of compressing particles from the center to 5 mN at a speed of 0.33 mN / sec and then reducing the load at a speed of 0.33 mN / sec. It is obtained by measuring. Compressive deformation recovery is the ratio (L1 / L2) of the displacement (L1) from the point where the load is reversed to the final unloading value and the displacement (L2) from the point where the load is reversed to the initial load value (%). Rate.

  The compressive fracture strength measured at 180 ° C. of the mother particles after the step (a) is preferably 10 mN or more.

  Since the crosslinked polymer fine particles according to the present embodiment have a high compression deformation recovery rate as described above, there is a high possibility of excellent elasticity. For this reason, when the crosslinked polymer fine particles are used as a conductive material, there is a low possibility of damaging or penetrating a substrate used for connection between electrodes. Even if the conductive material is highly compressed and deformed, there is a high possibility of exhibiting high-precision gap retention and stable connection reliability. Since the crosslinked polymer particles according to the present embodiment have the characteristics as described above, not only in the field of electric materials, but also paints, coating agents, light diffusing agents, cosmetics, medicines or biopsy elements, agricultural chemicals, building materials, etc. Useful in a wide range of fields.

  FIG. 2 is a cross-sectional view showing an embodiment of the anisotropic conductive adhesive. A film-like anisotropic conductive adhesive 20 shown in FIG. 2 is composed of a binder resin 3 and conductive particles 5 dispersed in the binder resin 3. The electroconductive particle 5 has the crosslinked polymer particle which concerns on this embodiment, and the metal layer (metal plating layer) which covers this crosslinked polymer particle.

  The binder resin 3 is not particularly limited, but is preferably an insulating adhesive composition. This insulating adhesive composition (binder resin 3) includes, for example, at least one component selected from a thermoplastic resin, a thermosetting resin, and an elastomer. Examples of the thermoplastic resin include vinyl resins such as vinyl acetate resins, vinyl chloride resins, acrylic resins and styrene resins; polyolefins; ethylene-vinyl acetate copolymers; polyamide resins; styrene-butadiene-styrene block copolymers. Polymers, thermoplastic block copolymers such as styrene-isoprene-styrene block copolymers and their hydrogenated products are selected. The thermosetting resin is selected from, for example, an epoxy resin, a urethane resin, a polyimide resin, and an unsaturated polyester resin. The thermosetting resin is usually contained in the binder resin 3 together with the curing agent. The thermosetting resin may be any one of a room temperature curable type, a thermosetting type, a photo curable type, and a moisture curable type. The elastomer is selected from, for example, styrene-butadiene copolymer rubber, chloroprene rubber, and acrylonitrile-styrene block copolymer rubber. These resins may be used alone or in combination of two or more.

  The insulating adhesive composition as the binder resin 3 may be, for example, an extender, a softener (plasticizer), an adhesive improver, an antioxidant (anti-aging agent), a heat stabilizer, if necessary. Various additives such as a light stabilizer, an ultraviolet absorber, a colorant, a flame retardant, and an organic solvent may be included.

  The anisotropic conductive adhesive according to the present embodiment can be obtained, for example, by a method in which conductive particles are added to a binder resin, mixed uniformly, and the conductive particles are dispersed. An anisotropic conductive adhesive containing a binder resin and conductive particles is applied to the release treatment surface of a release material such as release paper and release film in a state where it is dissolved by heating as it is or dissolved or dispersed in a solvent. And a film-like anisotropic conductive adhesive can be obtained by the method of drying or cooling as needed.

  The dispersion state of the conductive particles in the anisotropic conductive adhesive is not particularly limited. The conductive particles may be uniformly dispersed in the binder resin, or may be distributed unevenly in the vicinity of the surface layer of the film. The form of the anisotropic conductive adhesive is not limited to a film, and may be, for example, a paste or ink.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

1. Synthesis synthesis example 1 of mother particles
The following compounds were charged all at once into a 100 mL three-necked flask and stirred for about 6 hours using a stirrer while heating in a water bath at 80 ° C. to form mother particles formed from a crosslinked polymer.
DVB-960 (Nippon Steel Chemical, 96% by mass of divinylbenzene (DVB), 3% by mass of ethylvinylbenzene (EVB)): 4.9 g
・ Methacrylic acid (Wako Pure Chemical Industries): 2.1g
・ Azobisisobutyronitrile (AIBN, Wako Pure Chemical Industries): 0.6g
・ Acetonitrile (Wako Pure Chemical Industries): 70g

  Next, the mother particles are filtered using a suction filtration facility, and washing and filtration with isopropyl alcohol (IPA, Wako Pure Chemical Industries) are repeated about 3 to 5 times, followed by vacuum drying to obtain powdery mother particles. It was. When the particle diameter of the obtained mother particle was measured by SEM observation, it was a spherical monodisperse particle having an average particle diameter of 4.1 μm. The Cv value of the particle diameter was 2.3%.

Synthesis example 2
The following compounds were charged all at once into a 100 mL three-necked flask and stirred for about 6 hours using a stirrer while heating in a water bath at 80 ° C. to form mother particles formed from a crosslinked polymer.
DVB-960: 2.8g
・ Methacrylic acid: 4.2 g
・ AIBN: 0.6g
-Acetonitrile: 70 g

  Next, the mother particles are filtered using a suction filtration facility, and washing and filtration with isopropyl alcohol (IPA, Wako Pure Chemical Industries) are repeated about 3 to 5 times, followed by vacuum drying to obtain powdery mother particles. It was. When the particle diameter of the obtained mother particle was measured by SEM observation, it was a spherical monodisperse particle having an average particle diameter of 3.1 μm. The Cv value of the particle diameter was 3.0%.

Synthesis example 3
The following compounds were charged all at once into a 100 mL three-necked flask and stirred for about 6 hours using a stirrer while heating in a water bath at 80 ° C. to form mother particles formed from a crosslinked polymer.
DVB-960: 0.9g
・ 1,10-decanediol diacrylate (A-DOD, Shin-Nakamura Chemical Co., Ltd.): 2.7 g
・ Methacrylic acid: 2g
・ 11-Undecenoic acid: 1.4g
・ AIBN: 0.07g
-Acetonitrile: 70 g

  Next, the mother particles are filtered using a suction filtration facility, and washing and filtration with isopropyl alcohol (IPA, Wako Pure Chemical Industries) are repeated about 3 to 5 times, followed by vacuum drying to obtain powdery mother particles. It was. When the particle diameter of the obtained mother particle was measured by SEM observation, it was a spherical monodisperse particle having an average particle diameter of 2.8 μm. The Cv value of the particle diameter was 2.7%.

  The compression deformation recovery rate and compressive fracture strength of each mother particle obtained in Synthesis Examples 1 to 3 were measured. The measurement results are summarized in Table 1.

2. Preparation of crosslinked polymer particles and conductive particles and evaluation example 1
(Process a)
A 100 mL eggplant flask was charged with the following proportion of the mixture at one time and stirred at room temperature for 1 hour using a stirrer to obtain a dispersion. The dispersion was heated in a 180 ° C. oil bath for about 6 hours under a nitrogen stream.
-Mother particles of Synthesis Example 1: 5 parts by weight-Hexamethylenediamine (molecular weight 116.2): 1 part by weight (ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
Polyethyleneimine (molecular weight 300): 0.8 part by weight (the ratio of amino group to carboxyl group in the mother particle is 1 equivalent)
・ Γ-butyrolactone: 93.2 parts by weight

  Next, the particles are filtered using a suction filtration facility, and washing and filtration with IPA are repeated about 3 to 5 times, followed by vacuum drying and powdery mother particles crosslinked with hexamethylenediamine and polyethyleneimine ( Particles 1a) were obtained. The compression deformation recovery rate at 180 ° C. of the obtained mother particles was 56%, and the compression fracture strength was 16 mN.

(Process c)
The particles 1a were subjected to Ni plating by the following operation to produce conductive particles composed of crosslinked polymer particles and a Ni plating layer covering the particles.

(Catalyst added)
A stock solution of Activator Neogant 834 manufactured by Atotech Japan Co., Ltd. (trade name, palladium ion-amino complexing agent aqueous solution) is diluted to 40 mL / L with water, adjusted to pH 10.5, and then a one-component alkaline catalyst A liquid was prepared. The particles 1a were immersed in this alkaline catalyst solution at 35 ° C. for 10 minutes to adsorb the palladium complex on the surfaces of the particles 1a. The particles 1a were collected by suction filtration and washed with water. Thereafter, the particles 1a were again suspended in water. Thereto was added dimethylamine borane at 0.1 g / L to reduce the palladium complex on the surface of the particles 1a, and a suspension of particles 1a with palladium supported on the surface was obtained.

(Electroless plating)
The above suspension is heated to 80 ° C., and an electroless Ni—P plating solution (manufactured by Hitachi Chemical Co., Ltd., trade name: NIPS-100) is gradually added dropwise through a metering pump to particles 1a. Plating treatment was performed. The plating time was 60 minutes. Thereby, the plating layer was formed on the surface of the particle 1a. Thereafter, suction filtration, washing with water, suction filtration, and drying were sequentially performed to obtain conductive particles having a plating layer by electroless Ni—P plating. In the obtained conductive particles, the plating layer was formed with good uniformity, and no irregularities were observed on the surface of the plating layer.

(Crushing treatment and particle evaluation)
The obtained conductive particles were pulverized by a jet mill under a pulverization pressure of 0.1 MPa. The conductive particles after the pulverization treatment were observed with an electron microscope and photographed. The magnification was adjusted so that 1000 particles were photographed for each photograph, and 10 photographs were taken while changing the photographing location for each photograph. In these 10 photographs (total number of particles = 10000), the number of particles not completely covered with the plating layer and the number of plated pieces were examined. When there is much aggregation before the crushing treatment, the coating layer is not completely covered, and the number of particles in which the resin is partially exposed increases. Further, when the adhesion between the resin particles and the plating layer is not good, the plating is peeled off by the crushing treatment, and a large amount of plated pieces are generated after the crushing treatment. For this reason, in the conductive particles after the pulverization treatment, the number of particles not completely covered with the plating layer is small (the number of particles completely covered with the plating layer is large), and the number of plated pieces is small, It can be determined that the dispersibility of the particles in the plating solution is good and that the adhesion between the resin particles and the plating layer is excellent. In the observation after crushing, the presence of the plated piece was hardly confirmed.

Example 2
A 100 mL eggplant flask was charged with the following proportion of the mixture at one time and stirred at room temperature for 1 hour using a stirrer to obtain a dispersion. The dispersion was heated in a 180 ° C. oil bath for about 6 hours under a nitrogen stream.
-Mother particles of Synthesis Example 1: 5 parts by weight-Hexamethylenediamine (molecular weight 116.2): 1 part by weight (ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
Polyethyleneimine (molecular weight 600): 0.9 parts by weight (the ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
・ Γ-butyrolactone: 93.1 parts by weight

  Next, the particles are filtered using a suction filtration facility, and washing and filtration with IPA are repeated about 3 to 5 times, followed by vacuum drying and powdery mother particles (particles) crosslinked with hexamethylenediamine and polyethyleneimine. 2a) was obtained. The compression deformation recovery rate at 180 ° C. of the obtained mother particles was 54%, and the compression fracture strength was 15 mN.

(Process c)
In the same manner as in Example 1, Ni particles were applied to the particles 2a to produce conductive particles composed of crosslinked polymer particles and a Ni plating layer covering the particles. In the obtained conductive particles, the plating layer was formed with good uniformity, and no irregularities were observed on the surface of the plating layer. Moreover, in the observation after crushing, the presence of the plated piece was hardly confirmed.

Example 3
A 100 mL eggplant flask was charged with the following proportion of the mixture at one time and stirred at room temperature for 1 hour using a stirrer to obtain a dispersion. The dispersion was heated in a 180 ° C. oil bath for about 6 hours under a nitrogen stream.
-Mother particles of Synthesis Example 1: 5 parts by weight-Hexamethylenediamine (molecular weight 116.2): 1 part by weight (ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
Polyethyleneimine (molecular weight 1200): 0.9 part by weight (ratio of amino group to carboxyl group in mother particle is 1 equivalent)
・ Γ-butyrolactone: 93.1 parts by weight

  Next, the particles are filtered using a suction filtration facility, and washing and filtration with IPA are repeated about 3 to 5 times, followed by vacuum drying and powdery mother particles (particles) crosslinked with hexamethylenediamine and polyethyleneimine. 3a) was obtained. The compression deformation recovery rate at 180 ° C. of the obtained mother particles was 53%, and the compression fracture strength was 16 mN.

(Process c)
By the same operation as in Example 1, Ni particles were applied to the particles 3a to produce conductive particles composed of crosslinked polymer particles and a Ni plating layer covering the particles. In the obtained conductive particles, the plating layer was formed with good uniformity, and no irregularities were observed on the surface of the plating layer. Moreover, in the observation after crushing, the presence of the plated piece was hardly confirmed.

Example 4
A 100 mL eggplant flask was charged with the following proportion of the mixture at one time and stirred at room temperature for 1 hour using a stirrer to obtain a dispersion. The dispersion was heated in a 180 ° C. oil bath for about 6 hours under a nitrogen stream.
-Mother particles of Synthesis Example 1: 5 parts by weight-Hexamethylenediamine (molecular weight 116.2): 1 part by weight (ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
Polyethyleneimine (molecular weight 1800): 0.9 part by weight (ratio of amino group to carboxyl group in the mother particle is 1 equivalent)
・ Γ-butyrolactone: 93.1 parts by weight

  Next, the particles are filtered using a suction filtration facility, and washing and filtration with IPA are repeated about 3 to 5 times, followed by vacuum drying and powdery mother particles (particles) crosslinked with hexamethylenediamine and polyethyleneimine. 4a) was obtained. The compression deformation recovery rate at 180 ° C. of the obtained mother particles was 55%, and the compression fracture strength was 16 mN.

(Process c)
By the same operation as in Example 1, Ni particles were applied to the particles 4a to produce conductive particles composed of crosslinked polymer particles and a Ni plating layer covering the particles. In the obtained conductive particles, the plating layer was formed with good uniformity, and no irregularities were observed on the surface of the plating layer. Moreover, in the observation after crushing, the presence of the plated piece was hardly confirmed.

Example 5
A 100 mL eggplant flask was charged with the following proportion of the mixture at one time and stirred at room temperature for 1 hour using a stirrer to obtain a dispersion. The dispersion was heated in a 180 ° C. oil bath for about 6 hours under a nitrogen stream.
-Mother particles of Synthesis Example 1: 5 parts by weight-Hexamethylenediamine (molecular weight 116.2): 1 part by weight (ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
Polyethyleneimine (molecular weight 10,000): 0.9 part by weight (the ratio of amino group to carboxyl group in the mother particle is 1 equivalent)
・ Γ-butyrolactone: 93.1 parts by weight

  Next, the particles are filtered using a suction filtration facility, and washing and filtration with IPA are repeated about 3 to 5 times, followed by vacuum drying and powdery mother particles (particles) crosslinked with hexamethylenediamine and polyethyleneimine. 5a) was obtained. The compression deformation recovery rate at 180 ° C. of the obtained mother particles was 57%, and the compression fracture strength was 16 mN.

(Process c)
By the same operation as in Example 1, Ni particles were applied to the particles 5a to produce conductive particles composed of crosslinked polymer particles and a Ni plating layer covering the particles. In the obtained conductive particles, the plating layer was formed with good uniformity, and no irregularities were observed on the surface of the plating layer. Moreover, in the observation after crushing, the presence of the plated piece was hardly confirmed.

Example 6
(Process a)
A 100 mL eggplant flask was charged with the following proportion of the mixture at one time and stirred at room temperature for 1 hour using a stirrer to obtain a dispersion. The dispersion was heated in a 180 ° C. oil bath for about 6 hours under a nitrogen stream.
-Mother particles of Synthesis Example 2: 5 parts by weight-Ethylenediamine (molecular weight 60.2): 1 part by weight (ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
Polyethyleneimine (molecular weight 1200): 1.8 parts by weight (the ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
・ Γ-Butyrolactone (Wako Pure Chemical) 91.7 parts by weight

  Next, the particles are filtered off using a suction filtration facility, and after washing with IPA and filtration are repeated about 3 to 5 times, the particles are vacuum-dried, and are powdery mother particles crosslinked with ethylenediamine and polyethyleneimine (particles 6a) Got. The compression deformation recovery rate at 180 ° C. of the obtained mother particles was 51%, and the compression fracture strength was 11 mN.

(Process c)
By the same operation as in Example 1, Ni particles were applied to the particles 6a to produce conductive particles composed of crosslinked polymer particles and a Ni plating layer covering the particles. In the obtained conductive particles, the plating layer was formed with good uniformity, and no irregularities were observed on the surface of the plating layer. Moreover, in the observation after crushing, the presence of the plated piece was hardly confirmed.

Example 7
(Process a)
A 100 mL eggplant flask was charged with the following proportion of the mixture at one time and stirred at room temperature for 1 hour using a stirrer to obtain a dispersion. The dispersion was heated in a 180 ° C. oil bath for about 12 hours under a nitrogen stream.
-Mother particles of Synthesis Example 3: 5 parts by weight-Pentaethylenehexamine (molecular weight 232.4): 0.27 parts by weight (the ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
Polyethyleneimine (molecular weight 300): 1 part by weight (ratio of amino group to carboxyl group in the mother particle is 1 equivalent)
・ Γ-Butyrolactone (Wako Pure Chemical) 93.7 parts by weight

  Next, the particles are filtered using a suction filtration facility, and washing and filtration with IPA are repeated about 3 to 5 times, followed by vacuum drying, and powdery mother particles crosslinked with pentamethylenehexamine and polyethyleneimine ( Particles 7a) were obtained. The compression deformation recovery rate at 180 ° C. of the obtained mother particles was 45%, and the compression fracture strength was 12 mN.

  By the same operation as in Example 1, Ni particles were applied to the particles 7a to produce conductive particles composed of crosslinked polymer particles and a Ni plating layer covering the particles. In the obtained conductive particles, the plating layer was formed with good uniformity, and no irregularities were observed on the surface of the plating layer. Moreover, in the observation after crushing, the presence of the plated piece was hardly confirmed.

Comparative Example 1
The mother particles synthesized in Synthesis Example 2 were used as they were, and the compression characteristics and the formation state of the plating layer were evaluated.

Comparative Example 2
Except having used the mixture of the following ratio as a raw material in the process a, the process of the mother particle of the synthesis example 1 and preparation and evaluation of the electroconductive particle were performed by the same operation as Example 1.
-Mother particles of Synthesis Example 1: 5 parts by weight-Hexylamine (molecular weight 100): 1.7 parts by weight (ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
・ Γ-butyrolactone: 92.3 parts by weight

Comparative Example 3
Except having used the mixture of the following ratio as a raw material in the process a, the process of the mother particle of the synthesis example 1 and preparation and evaluation of the electroconductive particle were performed by the same operation as Example 1.
-Mother particles of Synthesis Example 1: 5 parts by weight-Polyethyleneimine (molecular weight 600): 0.9 parts by weight (ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
・ Γ-butyrolactone: 91.4 parts by weight

Comparative Example 4
Except having used the mixture of the following ratio as a raw material in the process a, the process of the mother particle of the synthesis example 1 and preparation and evaluation of the electroconductive particle were performed by the same operation as Example 1.
-Mother particles of Synthesis Example 1: 5 parts by weight-Polyethyleneimine (molecular weight 1200): 0.9 parts by weight (the ratio of amino groups to carboxyl groups in the mother particles is 1 equivalent)
・ Γ-butyrolactone: 91.4 parts by weight

  The evaluation results are shown in Table 2. The crosslinked polymer particles obtained in each example had good compression properties. Moreover, it was possible to form a plating layer on the surface of the crosslinked polymer particles of each Example with good uniformity. Furthermore, since there was almost no plating piece after crushing electroconductive particle, it was also confirmed that the adhesiveness of a resin particle and a plating layer is excellent. On the other hand, each particle of the comparative example was not sufficient in either compression characteristics or plating properties. From the above experimental results, according to the present invention, it was confirmed that crosslinked polymer particles having good compression characteristics and capable of forming a plating layer on the surface in a good state are provided.

  It turned out that the crosslinked polymer particle which concerns on this invention satisfy | fills a useful characteristic as particle | grains used for electrically conductive materials including an anisotropically conductive film and an electrically conductive paste. Furthermore, since the crosslinked polymer particles obtained by the production method of the present invention are excellent in heat resistance, chemical resistance, reactivity, and solution dispersibility, spacers for liquid crystals, conductive fine particles and conductive materials using the same, Electrostatic developer, silver salt film surface modifier, magnetic tape film modifier, thermal paper running stabilizer, toner and other electrical and electronic industries, ink, adhesive, adhesive, light diffusing agent, paint , Addition to chemical field such as paper coating agent such as paper coating and information recording paper, general industrial field such as fragrance, low shrinkage agent, paper, dental material, resin modifier, liquid or powder cosmetics It can be suitably used in a wide range of fields such as cosmetics such as slipping agents and extender pigments, biological and medical fields such as living body and antigen-antibody reaction test particles, pharmaceuticals and agrochemicals, building fields, and automobile fields.

  DESCRIPTION OF SYMBOLS 1 ... Crosslinked polymer particle, 3 ... Binder resin, 5 ... Conductive particle, 10 ... Mother particle.

Claims (8)

A step of contacting a mother particle formed from a cross-linked polymer having a functional group with an amino compound having two or more amino groups, and further cross-linking the cross-linked polymer by a reaction between the functional group and the amino group (a )
The amino compound comprises a low molecular weight amino compound having a molecular weight of less than 500;
The crosslinked polymer is a copolymer formed by copolymerizing a monomer mixture containing 10% by mass or more of a monomer having two or more unsaturated double bonds, and the two or more unsaturated polymers The monomer having a double bond includes at least one selected from divinylbenzene and di (meth) acrylate,
The mother particles after the step (a) have a compression deformation recovery rate of 40% or more and a compression fracture strength of 10 mN or more at 180 ° C.
Crosslinked polymer particles obtainable by a production method.   The crosslinked polymer particle according to claim 1, wherein the amino compound further comprises a high molecular weight amino compound having a molecular weight of 500 to 10,000.   The crosslinked polymer particle according to claim 1 or 2, wherein the average particle size is 0.1 to 10 µm, and the Cv value of the particle size is 10% or less.   The crosslinked polymer particle according to any one of claims 1 to 3, wherein the functional group is at least one selected from the group consisting of a carboxyl group, an epoxy group, and a glycidyl group.   The crosslinked polymer particle according to any one of claims 1 to 4, wherein the mother particle is a particle that can be obtained by suspension polymerization, emulsion polymerization, dispersion polymerization, precipitation polymerization, or seed polymerization. A step of contacting a mother particle formed from a cross-linked polymer having a functional group with an amino compound having two or more amino groups, and further cross-linking the cross-linked polymer by a reaction between the functional group and the amino group (a )When,
A step (c) of plating the crosslinked polymer particles,
The amino compound is seen containing a low molecular weight amino compound having a molecular weight of less than 500,
The crosslinked polymer is a copolymer formed by copolymerizing a monomer mixture containing 10% by mass or more of a monomer having two or more unsaturated double bonds, and the two or more unsaturated polymers The monomer having a double bond includes at least one selected from divinylbenzene and di (meth) acrylate,
The mother particles after the step (a) have a compression deformation recovery rate of 40% or more and a compression fracture strength of 10 mN or more at 180 ° C.
Conductive particles that can be obtained by a production method. The conductive particles according to claim 6 , wherein in the step (c), the crosslinked polymer particles are plated using a Pd ion complex as a plating catalyst. An anisotropic conductive adhesive provided with binder resin and the electroconductive particle of Claim 6 or 7 disperse | distributed in this binder resin.

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