JP2007179785A - Method of manufacturing conductive fine particles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing conductive fine particles which can reduce cost without using an expensive catalyst, obtains an even metal coating layer, and obtains greatly high temporal stability. <P>SOLUTION: In the method of manufacturing the conductive fine particles (E), microwave is irradiated to a mixture containing polymer fine particles (A), a compound with a functional group (b) of high metal affinity, metal fine particles (C) and solvent D with relative permittivity ε of 20-90 at 25°C, and a reducing agent (G) if needed. In other case, in the method of manufacturing the conductive fine particles (E), microwave is irradiated to a mixture containing polymer fine particles (F) each having the functional group (b) of high metal affinity on its surface, the metal fine particles (C) and the solvent (D) with relative permittivity ε of 20-90 at 25°C, and the reducing agent (G) if needed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing conductive fine particles used for conductive pastes and anisotropic conductive materials.

  Examples of the method for metal-coating the surface of non-conductive particles such as resin fine particles include electroless plating as a wet method, metal vapor deposition as a dry method, and the electroless plating method is often used. . However, the electroless plating method has a complicated manufacturing process and generally requires a high manufacturing cost due to the necessity of using an expensive catalyst or the like. Usually, conductive fine particles are used in which a base nickel layer is applied and further subjected to displacement gold plating. However, since the underlying nickel layer has high contact resistance and easily forms an oxide film, it is difficult to make the gold coating uniform. In addition, it contains halogen ions and alkali metal ions derived from various reagents used in the plating process, and these ionic components are liberated under severe conditions such as high temperature and high humidity or long-term continuous use. However, there has been a problem of corroding the metal coating layer and the opposing electrode terminals. (Patent Document 1)

On the other hand, a method is disclosed in which gold is directly attached to the surface of resin fine particles by a metal vapor deposition method, and gold is further coated by electroless gold plating (Patent Document 2). However, since it is difficult to deposit gold evenly on the surface of the resin fine particles by the metal vapor deposition method, which is a dry method, it is still insufficient for the demand for further stability over time due to recent rapid progress in electronic equipment. I was not satisfied.
JP 2004-14409 A JP-A-9-171714

  The present invention has been made in view of the above situation, and provides a method for producing conductive fine particles that does not use an expensive catalyst, reduces cost, and has a uniform metal coating layer and extremely high temporal stability. It was made for the purpose of doing.

The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems.
That is, the present invention relates to a polymer fine particle (A), a compound (B) having a functional group (b) having a high metal affinity, a metal salt (C), a solvent having a relative dielectric constant ε at 25 ° C. of 20 to 90 (D ), And if necessary, a method for producing conductive fine particles (E), wherein the mixture containing the reducing agent (G) is irradiated with microwaves,
In addition, fine polymer particles (F) having a functional group (b) having a high metal affinity on the surface, a metal salt (C), a solvent (D) having a relative dielectric constant ε of 20 to 90 at 25 ° C., and reduction if necessary It is also a method for producing conductive fine particles (E), wherein the mixture containing the agent (G) is irradiated with microwaves.

  According to the method for producing conductive fine particles of the present invention, reduction in production cost can be achieved, and the conductive fine particles obtained by this production method have the characteristics that the metal coating layer is uniform and the stability over time is excellent.

The first aspect of the present invention is a polymer fine particle (A), a compound (B) having a functional group (b) having a high metal affinity, a metal salt (C), and a solvent having a relative dielectric constant ε at 20 ° C. of 20 to 90. A method for producing conductive fine particles (E), wherein the mixture containing (D) and, if necessary, the reducing agent (G) is irradiated with microwaves.
In the present invention, polymer fine particles (A) are dispersed in a solvent (D) in which a compound (B), a metal salt (C), and, if necessary, a reducing agent (G) are dissolved or dispersed, and microwave irradiation is performed. The method is preferred.

As the functional group (b) having a high metal affinity, for example, a thiol group, sulfide group, disulfide group, thiocarboxyl group, thioisocyanate group, thiocyanate group, thioacetamide group, thiourea group, amino group, cyano group, sulfo group, A phosphono group, a carboxyl group, a hydroxyl group, an aldehyde group, etc. are mentioned, Among these, a thiol group and a disulfide group are preferable, and a thiol group is particularly preferable.
In the production method of the present invention, when (b) is a reducing functional group, that is, a thiol group, an amino group, a hydroxyl group, an aldehyde group, etc., it is not always necessary to use a reducing agent (G). (B) is a non-reducing functional group, that is, sulfide group, disulfide group, thiocarboxyl group, thioisocyanate group, thiocyanate group, thioacetamide group, thiourea group, cyano group, sulfo group, phosphono group, carboxyl group. In such a case, it is necessary to use a reducing agent (G).

The blending weight ratio of the polymer fine particles (A), the compound (B), the metal fine particles (C), the reducing agent (G) and the solvent (D) is preferably (0.01-30): (0.001-10): (0.005-60) :( 0-10) :( 50-200), more preferably (0.1-20) :( 0.01-5) :( 0.06-50) :( 0-5): (50-200).
Compound (B), metal salt (C), and reducing agent (G) are preferably dissolved in solvent (D).
The order of adding (A), (B), (C), (G) in the solvent (D) is not particularly limited, but after dissolving (B) and (G) in (D), (A) It is preferable to irradiate microwaves after dispersing (C) and further adding (C).

The microwave is electromagnetic energy having a wavelength of 1 meter to 0.1 millimeter and a frequency of 0.3 to 300 gigahertz, and the mixture of (A), (B), (C), and (D) is irradiated with microwaves. As a condition for this, a frequency of 2.45 GHz and a wavelength of 12.2 cm are preferable.
The microwave irradiation apparatus may be either a multimode or a single mode, but an apparatus capable of controlling temperature and pressure and capable of stirring and refluxing is preferable.

  The polymer fine particles (A) are not particularly limited, but usable resins include, for example, polyolefins such as polystyrene, polydivinylbenzene, polyvinyl chloride, polypropylene, polyethylene, polyisobutylene, styrene-acrylonitrile copolymers, acrylonitrile. -Acrylic acid derivatives (co) polymers such as butadiene-styrene terpolymers, polyacrylates, polymethylmethacrylates, polyacrylamides, polyvinyl compounds such as polyvinyl acetate and polyvinyl alcohol, and the above vinyl resins; polyacetals, polyethylene glycols, polypropylene glycols , Ether polymers such as epoxy resins; amino acids such as benzoguanamine, urea, thiourea, melamine, acetoguanamine, dicyanamide, and aniline Polyurethane, polyester, polyamide resin, silicone resin, fluororesin, or the like nitrile resin; compound with formaldehyde, paraformaldehyde, acetaldehyde, amino resins consisting of aldehydes, such as glyoxal.

  In particular, when used for conductive pastes and anisotropic conductive materials, heat resistance is required, and particularly when used for anisotropic conductive materials, a certain degree of hardness and elasticity are required in addition to heat resistance. Therefore, an epoxy resin, a polyamide resin, a polyester resin, a polyurethane resin, a silicone resin, a vinyl resin, and the like are preferable, and those having a crosslinking density controlled by these resins are more preferable.

Among the compounds (B) having a functional group (b) having a high metal affinity, examples of the compound having a thiol group include mercaptans, thiophenols, mercapto alcohols and the like.
More specifically, monomercaptans; methyl mercaptan, ethyl mercaptan, n-propyl mercaptan, n-butyl mercaptan, allyl mercaptan, n-hexyl mercaptan, n-octyl mercaptan, n-decyl mercaptan, n-dodecyl mercaptan, n -Tetradecyl mercaptan, n-hexadecyl mercaptan, n-octadecyl mercaptan, cyclohexyl mercaptan, isopropyl mercaptan, tert-butyl mercaptan, tert-nonyl mercaptan, tert-dodecyl mercaptan, benzyl mercaptan, 4-chlorobenzyl mercaptan, methylthioglycolate, Ethyl thioglycolate, n-butyl thioglycolate, n-octyl thioglycolate, methyl (3-methyl Captopropionate), ethyl (3-mercaptopropionate), 3-methoxybutyl (3-mercaptopropionate), n-butyl (3-mercaptopropionate), 2-ethylhexyl (3-elcaptopro) Pionate), n-octyl (3-mercaptopropionate), etc.
Polymercaptans: methanedithiol, 1,2-dimercaptoethane, 1,2-dimercaptopropane, 2,2-dimercaptopropane, 1,3-dimercaptopropane, 1,2,3-trimercaptopropane, 1 , 4-dimercaptobutane, 1,6-dimercaptohexane, bis (2-mercaptoethyl) sulfide, 1,2-bis (2-mercaptoethylthio) ethane, 1,5-dimercapto-3-oxapentane, 1 , 8-dimercapto-3,6-dioxaoctane, 2,2-dimethylpropane-1,3-dithiol, 3,4-dimethoxybutane-1,2-dithiol, 2-mercaptomethyl-1,3-dimercapto Propane, 2-mercaptomethyl-1,4-dimercaptobutane, 2- (2-mercaptoethylthio) -1,3-di Mercaptopropane, 1,2-bis (2-mercaptoethylthio) -3-mercaptopropane, 1,1,1-tris (mercaptomethyl) propane, tetrakis (mercaptomethyl) methane, ethylene glycol bis (2-mercaptoacetate) , Ethylene glycol bis (3-mercaptopropionate), 1,4-butanediol bis (2-mercaptoacetate), 1,4-butanediol bis (3-mercaptopropionate), trimethylolpropane tris (2- Mercaptoacetate), trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (2-mercaptocetate), pentaerythritol tetrakis (3-mercaptopropionate), 1,1-dimercaptocyclohe Xanthine, 1,4-dimercaptocyclohexane, 1,3-dimercaptocyclohexane, 1,2-dimercaptocyclohexane, 1,4-bis (mercaptomethyl) cyclohexane, 1,3-bis (mercaptomethyl) cyclohexane, 2, 5-bis (mercaptomethyl) -1,4-dithiane, 2,5-bis (2-mercaptoethyl) -1,4-dithiane, 2,5-bis (mercaptomethyl) -1-thiane, 2,5- Bis (2-mercaptoethyl) -1-thian, 1,4-bis (mercaptomethyl) benzene, 1,3-bis (mercaptomethyl) benzene, bis (4-mercaptophenyl) sulfide, bis (4-mercaptophenyl) Ether, 2,2-bis (4-mercaptophenyl) propane, bis [4- (mercaptomethyl) pheny Ru] sulfide, bis [4- (mercaptomethyl) phenyl] ether, 2,2-bis [4- (mercaptomethyl) phenyl] propane, 2,5-dimercapto-1,3,4-thiadiazole, 3,4- Thiofedithiol, aliphatic polythioether [for example, cup cure 3-800 (manufactured by Japan Epoxy Resin Co., Ltd., the structure is represented by formula (1) below), etc.], etc.
Cup cure 3-800;
Thiophenols; thiophenol, 1,2-dimercaptobenzene, 1,3-dimercaptobenzene, 1,4-dimercaptobenzene, 4,4′-thiodi (mercaptobenzene), mercapto alcohols; 2-mercaptoethanol , 3-mercapto-1,2-propanediol, 2-mercapto-1,3-propanediol, and the like. Furthermore, these compounds may contain bonds such as disulfide, sulfide, ether, sulfo, ketone, ester, etc. in the molecule. Among these, an aliphatic polythiol (Cup Cure 3-800, manufactured by Japan Epoxy Resin Co., Ltd.) is preferable.

The compound (B) in which (b) is a thiol group has a hydrophobic part and a hydrophilic part, and has a thiol group at the end of the hydrophilic part, preferably having a molecular weight of 200 to 10,000. Is mentioned.
The hydrophilic part preferably has an oxyethylene unit, specifically, a polyoxyethylene group, a polyoxyalkylene group comprising an ethylene oxide and propylene oxide (random or block) copolymer (30 mol of oxyethylene unit). % Or more).
As the hydrophobic part, a hydrocarbon group which may have an aromatic ring, [for example, phenol group, styrenated phenol group, alkylphenol group, styrenated alkylphenol group, bisphenol group (bisphenol A, bisphenol S, bisphenol F, etc.) And a residue obtained by removing a hydroxyl group, a linear and branched aliphatic hydrocarbon group], a hydrophobic polyoxyalkylene group (polyoxypropylene group, polyoxytetramethylene group) and the like.

Specific examples of the above (B) include those in which an oxyethylene unit is added to the hydrophobic part having a hydroxyl group, and a terminal group is thiolated. Among them, preferred are those in which the terminal group of the polyoxyethylene adduct of styrenated phenol group or styrenated alkylphenol group is thiolated.
The end group is thiolated by the following method.
1.5 Phosphorus sulfide (P ₂ S ₅ ) converts the hydroxyethyl group to a thiol group.
2. The hydroxyl group is converted to glycidyl ether with epichlorohydrin and further reacted with hydrogen sulfide to introduce a thiol group.

Compound (E) in which (b) is a sulfide group includes aliphatic sulfides; thiobis (diethylene glycol), thiobis (hexaethylene glycol), thiobis (pentadecaglycerol), thiobis (icosaethylene glycol), thiobis (pentaconta Ethylene glycol), 4,10-dioxa-7-thiatridecane-2,12-diol, thiodiglycerin, thiobis (triglycerin, 2,2'-thiodibutanol bis (octaethylene glycol pentaglycerol) ether, etc.
Heteroaromatic sulfide; thioanisole, 2-methylthiotoluene, 4-methylthiotoluene, 2-methylthiobiphenyl, 4-methylthiobiphenyl, 1,2-di (methylthio) benzene, 1,4-di (methylthio) benzene, 2- Methylthiodiphenyl sulfide, 4-methylthiodiphenyl sulfide, 4,4'-di (methylthio) diphenyl sulfide, 2- (benzyl) thioanisole, 4- (benzyl) thioanisole, 2- (methylthio) anisole, 4- (methylthio) Anisole, 2- (methylthio) phenol, 4- (methylthio) phenol, 2-methylthioaniline, 4-methylthioaniline, diphenyl sulfide, 2-methyldiphenyl sulfide, 4-methyldiphenyl sulfide, 2-phenyldiphenyl Sulfide, 4-phenyldiphenyl sulfide, 1,4-di (phenylthio) benzene, 2-methoxydiphenyl sulfide, 4-methoxydiphenyl sulfide, 2-hydroxydiphenyl sulfide, 4-hydroxydiphenyl sulfide, 2-aminodiphenyl sulfide, 4- Aminodiphenyl sulfide, 2-methylthiofuran, 2-methylthiothiophene, 2-methylthiopyrrole, 1-methylthionaphthalene, 2-phenylthiofuran, 2-phenylthiothiophene, 2-phenylthiopyrrole, 1-phenylthionaphthalene, etc. It is done.

  The compound (B) in which (b) is a disulfide group can be obtained by oxidation of a compound having a previous thiol group, and may be the same compound or a combination of two or more compounds, and is not particularly limited. .

  Examples of the compound (B) in which (b) is a thiocarboxyl group include thioacetic acid, thioacetic acid phenyl ester, tris (dithiocarboxy) diethylenetriamine, N1, N2-bis (dithiocarboxy) diethylenetriamine, and the like.

  As the compound (B) in which (b) is a thioisocyanate group, monothioisocyanate; phenylisothiocyanate, benzylisothiocyanate, etc., polythioisocyanate; 1,6-hexamethylenediiso (thio) cyanate, 2,2, 4- or 2,4,4-trimethylhexamethylene diiso (thio) cyanate, m-phenylenediiso (thio) cyanate, 2,4- or 2,6-toluylene di (thio) cyanate, m-xylylene diene Iso (thio) cyanate, α, α′-dimethylxylylene diiso (thio) cyanate, α, α, α ′, α′-tetramethylxylylene di (thio) cyanate, 4,4′-diphenylmethane diiso (thio) ) Cyanate, 4,4′-diiso (thio) cyanato-3,3′-dimethylbiphenyl, 4, '-Diiso (thio) cyanato-3,3'-dimethyldiphenylmethane, naphthylene-1,5-diiso (thio) cyanate, 1,3,5-benzenetriiso (thio) cyanate, 4,4', 4 "- Triiso (thio) cyanatotriphenylmethane, isophorone diiso (thio) cyanate, 1,3-bis (iso (thio) cyanatomethyl) cyclohexane, 1,3,5-tri (iso (thio) cyanatomethyl) cyclohexane, 4,4 '-Dicyclohexylmethane diiso (thio) cyanate, 2,5-bis (iso (thio) cyanatomethyl) bicyclo [2.2.1] heptane, 3,8-bis (iso (thio) cyanatomethyl) tricyclo [5.2 1.02,6] decane and the like.

  Examples of the compound (B) in which (b) is a thioacetamide group include thioacetamide, dimethylaminothioacetamide and the like.

  Examples of the compound (B) in which (b) is a thiourea group include thiocarbohydrazide, guanylthiourea, dicyclohexylthiourea, diphenylthiourea and the like.

  The compound (B) in which (b) is an amino group includes an aromatic amine compound; aniline, o-, m- or p-toluidine, o-, m- or p-phenylenediamine, 2, 4- or 2, 6-tolylenediamine, diaminodiphenylmethane, N-alkyl (alkyl having 1 to 8 carbon atoms) aniline, p-aminopyridine, and their formalin condensates, aliphatic amine compounds; methylamine, ethylamine, isopropylamine, n- Alkylamines (C1-8) such as butylamine, isobutylamine, cyclohexylamine, dialkylamines (C2-16) such as dimethylamine, diethylamine, diisopropylamine, di-n-butylamine, diisobutylamine, dicyclohexylamine, ethylenediamine , Diethylenetriamine, (Poly) alkylene polyamines (1 to 8 carbon atoms) such as reethylenetetramine, propylenediamine and iminobispropylamine, mono or dialkanolamines (1 to 1 carbon atoms) such as monoethanolamine, monopropanolamine, diethanolamine and dipropanolamine 4) and the like.

  Examples of the compound (B) in which (b) is a cyano group include benzonitrile, acetonitrile, adiponitrile and the like.

  As the compound (B) in which (b) is a sulfo group, dodecylbenzenesulfonic acid, sodium 1,3,5-benzenesulfonate, sodium 1,3,6-naphthalenesulfonate, allylsulfonic acid, vinylsulfonic acid, Propinsulfonic acid, 4,4'-bis [4,6-di (benzothiazolyl-2-thio) pyrimidin-2-ylamino] stilbene-2,2'-disulfonic acid disodium salt (A-2) 4,4 '-Bis [4,6-di (benzothiazolyl-2-amino) pyrimidin-2-ylamino] stilbene-2,2'-disulfonic acid disodium salt (A-3) 4,4'-bis [4,6- Di (naphthyl-2-oxy) pyrimidin-2-ylamino] stilbene-2,2'-disulfonic acid disodium salt (A-4) 4,4'-bis [4,6-di (na (Tyl-2-oxy) pyrimidin-2-ylamino] bibenzyl-2,2'-disulfonic acid disodium salt (A-5) 4,4'-bis (4,6-dianilinopyrimidin-2-ylamino) stilbene- 2,2'-disulfonic acid disodium salt and the like.

  Examples of the compound (B) in which (b) is a phosphono group include polyether phosphate esters and polyoxyethylene alkylphenyl phosphate esters.

  Examples of the compound (B) in which (b) is a carboxyl group include trisodium citrate, tripotassium citrate, trilithium citrate, disodium malate, disodium tartrate, and sodium glycolate.

  Examples of the compound (B) in which (b) is a hydroxyl group include a high molecular polyol (B1) and a low molecular weight polyol (B2).

Examples of the polymer polyol (B-1) used in the present invention include polyalkylene ether polyol (B1-1), polyester polyol (B1-2), polymer polyol (B1-3), polybutadiene polyol (B1- 4), castor oil-based polyol (B1-5), acrylic polyol (B1-6) and a mixture of two or more thereof.
The number average molecular weight of the polymer polyol (B-1) is usually 500 to 20,000, preferably 500 to 10,000, and more preferably 1,000 to 3,000.

  Examples of the polyalkylene ether polyol (B1-1) include compounds having a structure in which an alkylene oxide (hereinafter abbreviated as AO) is added to the active hydrogen atom-containing polyfunctional compound (a) and a mixture of two or more thereof. It is done.

  Examples of the active hydrogen atom-containing polyfunctional compound (a) include polyhydric alcohol (a1), polyhydric phenols (a2), amines (a3), polycarboxylic acid (a4), and phosphoric acids (a5). , Polythiol (a6) and the like.

  Examples of the polyhydric alcohol (a1) include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, Divalent alcohols such as neopentyl glycol, bis (hydroxymethyl) cyclohexane, bis (hydroxyethyl) benzene; glycerin, trimethylolpropane, pentaerythritol, diglycerin, α-methylglucoside, sorbitol , Xylit, mannitol, dipentaerythritol, glucose, fructose, sucrose, and the like.

  Examples of the polyhydric phenols (a2) include bisphenols such as bisphenol A, bisphenol F, and bisphenol S in addition to polyhydric phenols such as pyrogallol, catechol, and hydroquinone.

  Examples of amines (a3) include ammonia, monoamines such as alkylamines having 1 to 20 carbon atoms (such as butylamine) and aniline; aliphatic polyamines such as ethylenediamine, trimethylenediamine, hexamethylenediamine and diethylenetriamine; piperazine, N -Aminoethylpiperazine and other heterocyclic polyamines described in JP-B No. 55-21044; alicyclic polyamines such as dicyclohexylmethanediamine and isophoronediamine; phenylenediamine, tolylenediamine, diethyltolylenediamine, xylylenediamine, Aromatic polyamines such as diphenylmethanediamine, diphenyletherdiamine, polyphenylmethanepolyamine; and monoethanolamine, diethanolamine, triethanolamine Tri isopropanolate - alkanol such as triethanolamine - triethanolamine such, and the like.

  Examples of the polycarboxylic acid (a4) include aliphatic polycarboxylic acids such as succinic acid and adipic acid, and aromatic polycarboxylic acids such as phthalic acid, terephthalic acid and trimellitic acid.

Examples of phosphoric acids (a5) include phosphoric acid, phosphorous acid, and phosphonic acid. Examples of the polythiol (a6) include polyvalent polythiol compounds obtained by a reaction between a glycidyl group-containing compound and hydrogen sulfide.

  Two or more active hydrogen atom-containing compounds (a) described above can be used.

  Examples of AO added to the active hydrogen atom-containing compound (a) include ethylene oxide (EO), propylene oxide (PO), 1,2-, 2,3- or 1,3-butylene oxide, tetrahydrofuran (THF), and styrene. Examples thereof include oxide, α-olefin oxide, epichlorohydrin and the like.

AO may be used alone or in combination of two or more. In the latter case, both block addition (chip type, balance type, active secondary type, etc.) and random addition are mixed systems [chips after random addition: 0 to 50% by weight (preferably 5 to 40% by weight) of ethylene oxide chains distributed arbitrarily, and 0 to 30% by weight (preferably 5 to 25% by weight) of EO chains are chipped at the molecular ends. Things].
Among these AOs, preferred are EO alone, PO alone, THF alone, combined use of PO and EO, and combined use of PO and / or EO and THF (in the case of combined use, random, block and mixed system of both).

  The addition of AO to the active hydrogen atom-containing compound (a) can be carried out in the usual manner, without catalyst or in the presence of a catalyst (alkali catalyst, amine catalyst, acidic catalyst) (especially in the latter half of AO addition). In one step or in multiple steps at normal pressure or under pressure.

  In addition, the polyalkylene ether polyol (1) may be further polymerized by reacting with a small amount of polyisocyanate (described later) (polyalkylene ether polyol / polyisocyanate). Equivalent ratio: for example, generally 1.2 to 10/1, preferably 1.5 to 2/1).

  The equivalent amount (molecular weight per hydroxyl group) of the polyalkylene ether polyol (B1-1) is usually 100 to 10,000, preferably 250 to 5,000, more preferably 500 to 1,500. The functionality of the polyalkylene ether polyol (B1-1) is usually 2 to 8, preferably 2 to 3, particularly preferably 2.

  The degree of unsaturation of the polyalkylene ether polyol (B1-1) is preferably less, usually 0.1 meq / g or less, preferably 0.05 meq / g or less, more preferably 0.02 meq / g or less. .

  The primary hydroxyl group content of the polyalkylene ether polyol (B1-1) is usually 0 to 100%, preferably 30 to 100%, more preferably 50 to 100%, most preferably 70 to 100. %.

  The polyester polyol (B1-2) includes a ring-opening polymerization of a condensed polyester diol and a lactone obtained by reacting a low molecular diol and / or a polyalkylene ether diol having a molecular weight of 1000 or less and a dicarboxylic acid. And a polylactone diol obtained by the above, a polycarbonate diol obtained by reacting a low molecular diol with a carbonic acid diester of a lower alcohol (such as methanol), and the like.

Examples of the low molecular weight polyol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-, 1,3-butanediol, neopentyl glycol, 1, 6-hexanediol; low-molecular-weight polyols having a cyclic group [for example, those described in JP-B No. 45-1474: bis (hydroxymethyl) cyclohexane, bis (hydroxyethyl) benzene, ethylene oxide of bisphenol A Adducts, etc.], and mixtures of two or more thereof.
Examples of the polyalkylene ether glycol having a molecular weight of 1,000 or less include polytetramethylene ether glycol, polypropylene glycol, polyethylene glycol, and a mixture of two or more thereof.

  Dicarboxylic acids include aliphatic dicarboxylic acids (succinic acid, adipic acid, azelaic acid, sebacic acid, etc.), aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, phthalic acid, etc.), and ester-forming derivatives of these dicarboxylic acids. [Acid anhydride, lower alkyl (1 to 4 carbon atoms) ester and the like] and a mixture of two or more thereof; lactone includes ε-caprolactone, γ-butyrolactone, γ-valerolactone, and two of these The above mixture is mentioned.

Polyesterification can be carried out by a conventional method, for example, a low molecular weight polyol and / or a polyether diol with a molecular weight of 1000 or less is converted to a dicarboxylic acid or an ester-forming derivative thereof [for example, anhydrides (maleic anhydride, phthalic anhydride, etc.) , Lower esters (dimethyl adipate, dimethyl terephthalate, etc.), halides, etc., or anhydrides thereof and alkylene oxides (eg, ethylene oxide and / or propylene oxide) are reacted (condensed) or initiators (low molecular weight) Diol and / or polyether terdiol having a molecular weight of 1,000 or less) can be produced by adding a lactone.

  Specific examples of these polyester polyols (B1-2) include polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentyl adipate diol, polyethylene propylene adipate diol. Polyethylene butylene adipate diol, polybutylene hexamethylene adipate diol, polydiethylene adipate diol, poly (polytetramethylene ether) adipate diol, polyethylene azelate diol, polyethylene sebacate diol, poly Examples include butylene azelate diol, polybutylene sebacate diol, polycaprolactone diol or triol, and polyhexamethylene carbonate diol.

  As the polymer polyol (B1-3), a radical polymerizable monomer [for example, styrene, (meth) acrylonitrile, (meth) acrylic acid ester, chloride] in a polyol (the above-mentioned polyalkene ether polyol and / or polyester polyol). Vinyl, a mixture of two or more thereof] and the like, and the polymer is finely dispersed.

  A polymerization initiator is usually used to polymerize these monomers. As the polymerization initiator, those which generate free radicals to initiate polymerization, such as 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis- (2,4-dimethylvaleronitrile) ) (AVN) and other azo compounds; dibenzoyl peroxide, dicumyl peroxide, peroxides other than those described in JP-A-61-76517, persulfates, perborates, persuccinic acid, etc. Practically, azo compounds, particularly AIBN and AVN are preferable. The amount of the polymerization initiator used is 0.1 to 20% by mass, preferably 0.2 to 10% by mass, based on the total amount of monomers.

The polymerization reaction in polyol can be carried out without a solvent, but it is preferably carried out in the presence of an organic solvent when the polymer concentration is high. Examples of the organic solvent include benzene, toluene, xylene, acetonitrile, ethyl acetate, hexane, heptane, dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, isopropyl alcohol, n-butanol and the like. It is done.
If necessary, the polymerization is carried out in the presence of a known chain transfer agent (carbon tetrachloride, carbon tetrabromide, chloroform, enol ethers described in JP-A No. 55-31880) excluding alkyl mercaptans. Can be done.

  The polymerization can be carried out either batchwise or continuously. The polymerization reaction can be carried out at a temperature higher than the decomposition temperature of the polymerization initiator, usually 60 to 180 ° C., preferably 90 to 160 ° C., particularly preferably 100 to 150 ° C., even under atmospheric pressure or under pressure, and even under reduced pressure. Can be done.

  After the completion of the polymerization reaction, the obtained polymer polyol can be used as it is in the production of polyurethane without any post-treatment, but after the reaction is completed, the decomposition product of the organic solvent, polymerization initiator and unreacted monomer can be used. It is desirable to remove such impurities by conventional means.

  The polymer polyol (B1-3) thus obtained is usually 30 to 70%, preferably 40 to 60%, more preferably 45 to 55%, most preferably 50 to 55% of the polymerized total monomer, That is, it is a translucent or opaque white or tan dispersion in which the polymer is dispersed in polyol.

  The hydroxyl value of the polymer polyol (B1-3) is generally 10 to 300, preferably 20 to 250, and more preferably 30 to 200.

Examples of the polybutadiene polyol (B1-4) include those having a 1,2-vinyl structure, those having a 1,2-vinyl structure and a 1,4-trans structure, and those having a 1,4-trans structure. It is done. The ratio of the 1,2-vinyl structure and the 1,4-trans structure can be changed variously, for example, 100: 0 to 0: 100 in molar ratio. The polybutadiene glycol (4) includes homopolymers and copolymers (styrene butadiene copolymer, acrylonitrile butadiene copolymer, etc.), and hydrogenated products thereof (hydrogenation rate: for example, 20 to 100%).
The number average molecular weight of the polybutadiene glycol (B1-4) is usually 500 to 10,000.

  The castor oil-based polyol (B1-5) includes castor oil and modified castor oil (such as castor oil modified with a polyhydric alcohol such as trimethylolpropane and pentaerythritol).

  Examples of the low molecular polyol (B2) used in the present invention include 2 to 8 polyhydric alcohols, alkylene oxides of the polyhydric alcohols (ethylene oxide, propylene oxide, 1,2-, 1,3-, 2,3 -Or 1,4-butylene oxide, α-olefin oxide, styrene oxide, epichlorohydrin, etc.) adducts (molecular weight less than 500), alkylene oxide adducts of polyhydric phenols (molecular weight less than 500), phosphorus polyols, etc. .

  Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, neopentyl glycol, 1,4- Dihydric alcohols such as bis (hydroxymethyl) cyclohexane, 1,4-bis (hydroxyethyl) benzene, 2,2-bis (4,4′-hydroxycyclohexyl) propane; trihydric alcohols such as glycerin and trimethylolpropane; 4- to 8-valent alcohols such as pentaerythritol, diglycerin, α-methylglucoside, sorbitol, xylit, mannitol, dipentaerythritol, glucose, fructose, sucrose Etc.

Examples of the polyhydric phenols include polyhydric phenols such as pyrogallol, catechol, and hydroquinone; bisphenols such as bisphenol A, bisphenol F, and bisphenol S.
In addition, examples of the phosphorus-based polyol include alkylene oxide adducts (molecular weight less than 500) such as phosphoric acid, phosphorous acid, and phosphonic acid.

  Examples of the compound (B) in which (b) is an aldehyde group include acetaldehyde, acrylic aldehyde, malonaldehyde, succinaldehyde, malealdehyde, fumaraldehyde, benzaldehyde, 2-naphthaldehyde, phthalaldehyde, isophthalaldehyde, terephthalaldehyde, nicotine Aldehyde, isonicotinaldehyde, 2-furaldehyde, propionaldehyde, propioaldehyde, butyraldehyde, isobutyraldehyde, methacrylaldehyde, palmitoaldehyde, stearaldehyde, olealdehyde, glyoxal, glutaraldehyde, adipaldehyde, cinnamaldehyde, Glycolaldehyde, lactaldehyde, glyceraldehyde, tartaraldehyde, citrulaldehyde , Pyruvaldehyde, aceto acetaldehyde, benzaldehyde, anthranyl aldehyde include ethylenediaminetetraacetic acetaldehyde.

  The volume average particle diameter of the polymer fine particles (A) is preferably 0.1 μm or more, more preferably 0.5 μm or more, and preferably 60 μm or less from the viewpoint of conductivity, particularly when used in a conductive paste. More preferably, it is 20 μm or less. In particular, when used for an anisotropic conductive material, it is preferably 1 μm or more, more preferably 2 μm or more, particularly preferably 3 μm or more, preferably 60 μm or less, more preferably 20 μm or less, particularly preferably 10 μm or less. It is.

Examples of the metal salt (C) include basic salts of inorganic and organic acids, hydroxides, and acetylacetonate salts.
Examples of basic salts of organic acids include halides, acetates, nitrates, and sulfates.
Examples of basic salts of inorganic acids include carbonates.

Examples of the metal constituting the metal salt (C) include noble metals, rare metals, light metals, and base metals.
Gold, silver, copper, zinc, lead, manganese, chromium, nickel, mercury, etc. as noble metals, aluminum, magnesium, sodium, titanium, etc. as light metals, copper, lead, zinc, nickel, aluminum, etc. as base metals Etc.
Specific examples of the metal salt (C) include silver nitrate, tetrachloroauric (III) acid, nickel chloride, silver chloride and the like.

  As the solvent (D) having a relative dielectric constant ε of 20 to 90 at 25 ° C., water (dielectric constant 80), glycerin (dielectric constant 43), ethylene glycol (dielectric constant 38), acetonitrile (dielectric constant 38), dimethyl Examples include formamide (dielectric constant 37), ethanol (dielectric constant 32), and the like.

  Examples of the reducing agent (G) include amine compounds; alkali metal borohydride salts such as sodium borohydride; hydrazine compounds; citric acid; tartaric acid; ascorbic acid; formic acid; alcohols; aldehydes; A sulfoxylate derivative, and a mixture of two or more of these. Of these, alcohols and amine compounds are preferred.

  It does not specifically limit as said alcohol, For example, the polyol illustrated above is mentioned.

  Examples of amines include polyamines and amino alcohols.

As polyamines,
(1) Aliphatic polyamines (C ₂ -C ₁₈ ): aliphatic polyamines such as C ₂ -C ₆ alkylene diamines [ethylene diamine, propylene diamine, trimethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.], polyalkylenes ( C ₂ -C ₆₎ polyamines [diethylenetriamine, iminobispropylamine, bis (hexamethylene) triamine, triethylenetetramine, tetraethylene pentamine, pentaethylene hexamine, etc.], these alkyl (C ₁ -C ₄₎ or hydroxyalkyl (C ₂ ~C ₄₎ substituents [dialkyl (C ₁ ~C ₃₎ aminopropyl amine, trimethyl hexamethylene diamine, aminoethylethanolamine, methyl iminobispropylamine]; alicyclic or heterocycle-containing aliphatic Po Amines such 3,9-bis (3-aminopropyl) -2,4,8,10-spiro [5,5] undecane, and the like; aromatic ring-containing aliphatic amines (C ₈ -C _15), e.g. Xylylenediamine, tetrachloro-p-xylylenediamine, etc .;
(2) Alicyclic polyamines (C _{4 to} C ₁₅ ), such as 1,3-diaminocyclohexane, isophorone diamine, menthane diamine, 4,4′-methylene dicyclohexane diamine (hydrogenated methylene dianiline);
(3) heterocyclic polyamine (C ₄ -C ₁₅ ) such as piperazine, N-aminoethylpiperazine, 1,4-diaminoethylpiperazine, etc .;

(4) aromatic polyamines (C ₆ -C _20): unsubstituted aromatic polyamines, such as 1,2, 1,3- and 1,4-phenylenediamine, 2,4'- and 4,4'- Diphenylmethanediamine, crude diphenylmethanediamine [polyphenylpolymethylenepolyamine], diaminodiphenylsulfone, benzidine, thiodianiline, bis (3,4-diaminophenyl) sulfone, 2,6-diaminopyridine, m-aminobenzylamine, triphenylmethane- 4,4 ′, 4 ″ -triamine, naphthylenediamine; aromatic polyamines having a nuclear substituted alkyl group (eg, C ₁ -C ₄ alkyl groups such as methyl, ethyl, n- and i-propyl, butyl), eg, 2 , 4- and 2,6-tolylenediamine, crude tolylenediamine, di Tiltlylenediamine, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-bis (o-toluidine), dianisidine, diaminoditolylsulfone, 1,3-dimethyl-2,4-diamino Benzene, 1,3-diethyl-2,4-diaminobenzene, 1,3-dimethyl-2,6-diaminobenzene, 1,4-diethyl-2,5-diaminobenzene, 1,4-diisopropyl-2,5 -Diaminobenzene, 1,4-dibutyl-2,5-diaminobenzene, 2,4-diaminomesitylene, 1,3,5-triethyl-2,4-diaminobenzene, 1,3,5-triisopropyl-2, 4-diaminobenzene, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene 2,3-dimethyl-1,4-diaminonaphthalene, 2,6-dimethyl-1,5-diaminonaphthalene, 2,6-diisopropyl-1,5-diaminonaphthalene, 2,6-dibutyl-1,5-diamino Naphthalene, 3,3 ′, 5,5′-tetramethylbenzidine, 3,3 ′, 5,5′-tetraisopropylbenzidine, 3,3 ′, 5,5′-tetramethyl-4,4′-diaminodiphenylmethane , 3,3 ′, 5,5′-tetraethyl-4,4′-diaminodiphenylmethane, 3,3 ′, 5,5′-tetraisopropyl-4,4′-diaminodiphenylmethane, 3,3 ′, 5,5 '-Tetrabutyl-4,4'-diaminodiphenylmethane, 3,5-diethyl-3'-methyl-2', 4-diaminodiphenylmethane, 3,5-diisopropyl-3'-methyl-2 , 4-diaminodiphenylmethane, 3,3′-diethyl-2,2′-diaminodiphenylmethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 3,3 ′, 5,5′-tetraethyl-4, 4'-diaminobenzophenone, 3,3 ', 5,5'-tetraisopropyl-4,4'-diaminobenzophenone, 3,3', 5,5'-tetraethyl-4,4'-diaminodiphenyl ether, 3,3 ', 5,5'-tetraisopropyl-4,4'-diaminodiphenylsulfone, mixtures of these isomers in various proportions; nucleus-substituted electron withdrawing groups (eg halogens such as Cl, Br, I, F; methoxy, Aromatic polyamines having alkoxy groups such as ethoxy; nitro groups, etc.) such as methylenebis-o-chloroaniline, 4-chloro-o-phenyle Diamine, 2-chloro-1,4-phenylenediamine, 3-amino-4-chloroaniline, 4-bromo-1,3-phenylenediamine, 2,5-dichloro-1,4-phenylenediamine, 5-nitro- 1,3-phenylenediamine, 3-dimethoxy-4-aminoaniline; 4,4'-diamino-3,3'-dimethyl-5,5'-dibromo-diphenylmethane, 3,3'-dichlorobenzidine, 3,3 '-Dimethoxybenzidine, bis (4-amino-3-chlorophenyl) oxide, bis (4-amino-2-chlorophenyl) propane, bis (4-amino-2-chlorophenyl) sulfone, bis (4-amino-3-methoxy) Phenyl) decane, bis (4-aminophenyl) sulfide, bis (4-aminophenyl) telluride, bis (4-aminophenyl) Nyl) selenide, bis (4-amino-3-methoxyphenyl) disulfide, 4,4'-methylenebis (2-iodoaniline), 4,4'-methylenebis (2-bromoaniline), 4,4'-methylenebis ( 2-fluoroaniline), 4-aminophenyl-2-chloroaniline; aromatic polyamine having a secondary amino group [a part or all of —NH ₂ of the aromatic polyamine is —NH—R ′ (R ′ is alkyl A group such as a lower alkyl group such as methyl or ethyl)], for example, 4,4′-di (methylamino) diphenylmethane, 1-methyl-2-methylamino-4-aminobenzene;

(5) Polyamide polyamine [for example, low molecular weight polyamide polyamine obtained by condensation of dicarboxylic acid (dimer acid etc.) and excess (more than 2 mol per mol of acid) polyamine (alkylenediamine, polyalkylenepolyamine etc.)] ;
(6) Polyether polyamine [hydride of cyanoethylated polyether polyol (polyalkylene glycol, etc.)];
(7) Cyanoethylated polyamines [for example, cyanoethylated polyamines obtained by addition reaction of acrylonitrile and polyamines (the above-mentioned alkylenediamine, polyalkylenepolyamine, etc.), such as biscyanoethyldiethylenetriamine, etc.
(8) Hydrazines (such as hydrazine and monoalkylhydrazines), dihydrazides (such as succinic acid dihydrazide, adipic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide), guanidines (such as butylguanidine and 1-cyanoguanidine); and dicyandiamide Etc .; and mixtures of two or more of these.
Of these polyamines, polyether polyamines are preferred.

Amino alcohols include alkanolamines such as mono-, di- and tri-alkanolamines (monoethanolamine, monoisopropanolamine, monobutanolamine, triethanolamine, tripropanolamine, etc.); _{1 to} C ₄ ) Substituents [N, N-dialkylmonoalkanolamine (N, N-dimethylethanolamine, N, N-diethylethanolamine etc.), N-alkyldialkanolamine (N-methyldiethanolamine, N-butyl) Diethanolamine, etc.)]; and the quaternized nitrogen atom by a quaternizing agent such as dimethyl sulfate or benzyl chloride.
Of these, alkanolamines are preferred.

The second aspect of the present invention is a polymer fine particle (F) having a functional group (b) having a high metal affinity on the surface, a metal salt (C), and a solvent (D) having a relative dielectric constant ε of 20 to 90 at 25 ° C. , And if necessary, the mixture containing the reducing agent (G) is irradiated with microwaves.
The polymer fine particles (F) having a functional group (b) having a high metal affinity on the surface are preferably polymer fine particles formed by covalently bonding a functional group (b) having a high metal affinity to the surface.

  Examples of the polymer fine particles (F) include polymer fine particles (F1) formed by adsorbing a compound (B) having a functional group (b) having a high metal affinity on the surface of the polymer fine particles (A), and polymer fine particles (A0). There are polymer fine particles (F2) and the like in which a functional group (d) having a high metal affinity is covalently bonded to the surface. Preferred is (F2).

In the second invention, the functional group (b) having a high metal affinity, the fine polymer particles (A), the compound (B) having a functional group (b) having a high metal affinity, the metal salt (C), the ratio at 25 ° C. The solvent (D) and the reducing agent (G) having a dielectric constant ε of 20 to 90 are the same as those in the first invention.
Also in the production method of the second invention, when (b) is a reducing functional group, that is, a thiol group, amino group, hydroxyl group, aldehyde group, etc., it is not always necessary to use a reducing agent (G). . (B) is a non-reducing functional group, that is, sulfide group, disulfide group, thiocarboxyl group, thioisocyanate group, thiocyanate group, thioacetamide group, thiourea group, cyano group, sulfo group, phosphono group, carboxyl group. In such a case, it is necessary to use a reducing agent (G).

As a method for producing the polymer fine particles (F1), the polymer fine particles (A) are added to water or an organic solvent in which the compound (B) is dissolved and sufficiently stirred and dispersed, followed by filtration, washing with water and drying. A uniform adsorption layer can be formed by adjusting the amount of (E) in the range of 0.3 to 100 mg per 1 m ² / g of specific surface area of the polymer fine particles (A).

There are various polymer fine particles (F2) formed by covalently bonding the functional group (b) having a high metal affinity to the surface of the polymer fine particles (A). Particularly, (b) is a thiol group, disulfide group, Examples of the carboxyl group include the following.
(1) Epoxy resin particles having a thiol group on the thiol group surface, vinyl resin fine particles, polyurethane, polyester, polyamide resin, silicone resin, fluorine-containing resin, nitrile resin, and the like.
(2) Epoxy resin particles having a disulfide group on the disulfide group surface, vinyl resin fine particles, polyurethane, polyester, polyamide resin, silicone resin, fluorine-containing resin, nitrile resin, and the like.
(3) Epoxy resin particles having a carboxyl group on the surface of the carboxyl group, vinyl resin fine particles, polyurethane, polyester, polyamide resin, silicone resin, fluorine-containing resin, nitrile resin, and the like.
Among these, epoxy resin particles having a thiol group, polyurethane resin particles, and polyester resin particles are preferable.

The above (F2) can be produced, for example, by the following two methods.
(1) The compound having (b) is copolymerized during the production of polymer fine particles.
(2) The polymer fine particles having a reactive group on the surface are reacted with (b) and a compound having a functional group capable of reacting with the reactive group.
(3) The compound (g) which produces | generates this (b) is made to react at the time of manufacture of polymer microparticles.

As a compound (g) used by the manufacturing method (3) of the said polymer fine particle, the heterocyclic containing compound (g1) represented by following General formula (2) in a molecule | numerator is mentioned, for example.

R ¹ is a residue of the ether group-containing compound.
In the formula, n is an integer of 2 to 10, preferably 2 to 4, and X ¹ , Y ¹ and Z ¹ are each an oxygen or sulfur atom. Preferably, X ¹ is a sulfur atom (S), ^one of Y ¹ and Z ¹ is a sulfur atom (S), and the other is an oxygen atom (O).
R ² is a hydrocarbon group having 2 to 10 carbon atoms, and a trivalent hydrocarbon group represented by the general formula (3):

(M is an integer of 1 to 9). However, Y ¹ , Z ¹ and R ¹ represent binding partners with R ² and are not included in the general formula (3).

Or it is a tetravalent hydrocarbon group shown by General formula (4).

(M ′ is an integer of 0 to 8) However, Y ¹ , Z ¹ , and R ¹ represent binding partners with R ² and are not included in the general formula (3).

Examples of the trivalent hydrocarbon group include> CHCH ₂ —,> CHCH ₂ CH ₂ —,> CHCH ₂ CH ₂ CH ₂ —,> CHCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ — and the like. Examples of the tetravalent hydrocarbon group include> CHCH <,> CHCH ₂ CH <,> CHCH ₂ CH ₂ CH <,> CHCH ₂ CH ₂ CH ₂ CH ₂ CH <, and the like. A trivalent hydrocarbon group is preferable, and> CHCH ₂ — and> CHCH ₂ CH ₂ — are particularly preferable.

Preferable examples of the polymer fine particles (F2) include reaction products and polymers of the above (g1) and a compound (g2) having two or more nucleophilic groups in the molecule.
Examples of the compound (g2) include at least one selected from the group consisting of a polyol (g2-1), a polyamino compound (g2-2) and its precursor (g2-3), and a polythiol (g2-4). . It should be noted that ions generated by proton dissociation from the nucleophilic group in these compounds are also within the scope of the present invention. Among these, a polyamino compound (g2-2) or a precursor thereof (g2-3) is preferable.
As the nucleophilic group of the compound (g2), the _Sway -Scott nucleophilic parameter n _CH31 (J. _Am . _Chem . _Soc ., _90.17 . _319. 1968) is in the range of 0-12. For example, a hydroxyl group, 1,2, tertiary amino group, thiol group, sulfide group, phosphine group, arsine group, organic selenium group, hydroxide group, phenoxide group, halogen anion (For example, chloride anion), carboxylate ion (for example, acetate anion), and the like.

  The volume average particle diameter of the polymer fine particles (A) and the polymer fine particles (F) is preferably 0.1 μm or more, more preferably 0.5 μm or more, and more preferably 60 μm or less, particularly when used in a conductive paste. Preferably, it is 20 μm or less. In particular, when used for an anisotropic conductive material, it is preferably 1 μm or more, more preferably 2 μm or more, particularly preferably 3 μm or more, preferably 60 μm or less, more preferably 20 μm or less, particularly preferably 10 μm or less. It is. However, it can be considered that the polymer fine particles (A) and (F) have substantially the same volume average particle diameter.

  As a method for producing conductive fine particles (E), polymer fine particles having a functional group (b) having high metal affinity on the surface in a solvent (D) in which a metal salt (C) and a reducing agent (G) are dissolved A method of dispersing (F) and irradiating with microwaves is preferable.

The blending ratio (% by weight) of the polymer fine particles (F), metal salt (C), reducing agent (G) and solvent (D) is preferably (0.01-30) :( 0.005-60) :( 0 10) :( 50-200), more preferably (0.1-20) :( 0.06-50) :( 0-5) :( 50-200).
The order of adding (F), (C), and (G) in the solvent (D) is not particularly limited, but if necessary, after dissolving (G) in (D), (F) is dispersed, It is preferable to irradiate microwaves after adding (C).

  Conditions for irradiating the mixture of (F), (C), (D), and (G) with microwaves are the same as in the method of the first invention.

  The average coating thickness of the coating metal layer in the conductive fine particles (E) is preferably 0.01 μm to 0.5 μm, and more preferably 0.01 μm to 0.2 μm from the viewpoint of specific gravity.

  The conductive fine particles (E) obtained by the production method of the present invention can be dispersed in the binder (H) to produce a conductive paste and an anisotropic conductive material. The conductive paste is used for connection of various electronic components and a circuit forming material. The anisotropic conductive material is used as an electrode connection material in a liquid crystal display or the like.

As the binder (H), known thermosetting resins or thermoplastic resins can be used, and a thermosetting resin and a thermoplastic resin can be used in combination.
As a thermosetting resin, an epoxy resin, a phenol resin, a melamine resin, etc. are mentioned, for example.
Examples of the thermoplastic resin include polyolefin resins, acrylate resins, and polystyrene resins.
Examples of the polyolefin resin include polyethylene, ethylene-vinyl acetate copolymer, and ethylene- (meth) acrylic acid ester copolymer.
Examples of the acrylate resin include polymethyl (meth) acrylate, polyethyl (meth) acrylate, and polybutyl (meth) acrylate.
Examples of polystyrene resins include polystyrene, styrene-acrylic acid ester copolymers, SB type styrene-butadiene block copolymers, styrene-isoprene block copolymers, and block polymers such as these water additives. .
Among these, from the viewpoint of adhesion with the conductive metal (J), a thermosetting resin is preferable, and an epoxy resin is particularly preferable.
Mw (weight average molecular weight) by (H) gel permeation chromatography (GPC) [measurement conditions: temperature 40 ° C., tetrahydrofuran solvent, polystyrene equivalent] is usually 1,000 to 2,000,000, preferably 3,000 to One million.

  The amount of the conductive fine particles (E) used is 50 to 150% by weight based on the weight of the binder (H) in the conductive paste, and preferably 80 to 120% by weight from the viewpoint of conductivity. In the conductive material, it is 5 to 100% by weight, preferably 20 to 60% by weight, based on the weight of the binder (H).

  If the conductive fine particles (E) obtained by the production method of the present invention are used in a conductive paste or an anisotropic conductive material, the production cost can be reduced, and the metal coating layer is uniform and excellent in stability over time. Have.

Examples Examples Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited thereto. In the following, parts and% indicate parts by weight and% by weight, respectively.

The volume average particle diameter, specific gravity and metal layer average coating thickness were measured by the following methods.
<Volume average particle diameter>
When the volume average particle diameter was less than 1 μm, the measurement was performed using a dynamic light scattering particle diameter measuring apparatus (DLS-7000 manufactured by Otsuka Electronics Co., Ltd.). On the other hand, in the case of 1 micrometer or more, it measured using the laser diffraction type particle size distribution measuring device (LA-920 by Horiba, Ltd.).
<Specific gravity>
The specific gravity is measured according to 2. of JIS Z8807-1976 “Method for Measuring Solid Specific Gravity”. It measured based on the measuring method (liquid; distilled water or methanol) by a specific gravity bottle.
<Metal layer average coating thickness>
After weighing 0.5 g of conductive fine particles and dissolving in 10 ml of 30% nitric acid aqueous solution, the solution is accurately diluted to 200 ml while filtering with filter paper, and 0.01 MEDTA standard with Cu-PAN as an indicator under weak acidity. The metal content W was measured with the liquid, and the metal layer thickness was calculated according to the following formula.
Metal layer thickness (μm) = (ρ _P × W _M × D) / {6 × ρ _M × (100−W _M )}
ρ _P : Specific gravity of resin fine particles ρ _M : Specific gravity of metal W _M : Metal content (%) D: Number average particle diameter of resin fine particles (μm)

Example 1; <Production of conductive fine particles (E-1)>
Polyamide fine particles (nylon 612) obtained by ring-opening copolymerization of ε-caprolactam and ω-laurolactam were used as the polymer fine particles (A-1). Specifically, MW-330 (manufactured by Shinto Fine Co., Ltd., volume average particle size 7.7 μm) was used as it was without being subjected to treatment such as classification.
1.0 part of the fine particles were added to 100 parts of ethylene glycol to which 0.1 part of Cupcure 3-800 (manufactured by Japan Epoxy Resin Co., Ltd.) and 0.03 part of silver nitrate were added, and stirring was continued at room temperature for 20 minutes. Then, conductive fine particles (E-1) were obtained by stirring for 30 minutes at an oscillation output of 2.45 GHz and 60 ° C. in a microwave reactor (manufactured by Shikoku Keiki Kogyo) (gold layer thickness: 0.06 μm). , Specific gravity: 1.4, volume average particle diameter 7.8 μm). When the conductive fine particles (E-1) were observed using an electron microscope (SEM), it was confirmed that a uniform and dense silver coating layer free from defects or the like was formed.

Example 2 <Production of conductive fine particles (E-2)>
100 parts of a 3% by weight silver nitrate aqueous solution in which 1.0 part of polymer fine particles (A-1) dispersed at a liquid temperature of 60 ° C. was dispersed was irradiated with microwaves at an oscillation output of 2.45 GHz, and dimethylethanol was stirred. Conductive fine particles (E-2) were obtained by dropping 0.5 part of amine for 40 minutes (silver layer thickness: 0.09 μm, specific gravity: 1.4, volume average particle diameter 7.8 μm). When the conductive fine particles (E-2) were observed using an electron microscope (SEM), it was confirmed that a uniform and dense silver coating layer free from defects or the like was formed.

Example 3 <Production of conductive fine particles (E-3)>
(1) Production of heterocycle-containing compound (b0-1) 180 parts of carbon disulfide, 5 parts of lithium bromide and 240 parts of tetrahydrofuran (THF) were charged into a reaction vessel and stirred and dissolved, followed by 174 parts of ethylene glycol diglycidyl. The ether was added dropwise while keeping it at 20 ° C. or lower, and then aged at 40 ° C. for 5 hours. After distilling off THF and excess carbon disulfide under reduced pressure, the mixture was filtered to obtain a pale yellow liquid heterocyclic compound (b0-1) having a viscosity of 25 mPa · s and a heterocyclic group equivalent of 163.
(2) Production of polymer fine particles (F-1) A mixed liquid of 326 parts of a heterocyclic compound (b0-1) and 136 parts of metaxylylenediamine was used as an oil phase, and this oil phase was made into polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.). , GH-20) was added to 800 parts of a 3% aqueous solution, and emulsified by stirring at 10,000 rpm using a homomixer. This was put into a reaction vessel equipped with a stirring bar and a thermometer, and reacted at 40 ° C. for 10 hours under a nitrogen stream while stirring. The resulting suspension was filtered and washed with water, followed by classification to obtain polymer fine particles (F-1) obtained by covalently bonding a functional group thiol group having a high metal affinity to the surface (volume average particle size 8. 6 μm).
(3) Production of conductive fine particles (E-3) 1.8 parts of polymer fine particles (F-1) were added to 100 parts of ethylene glycol to which 0.03 part of silver nitrate was added, and stirring was continued for 20 minutes at room temperature. After that, the resultant was irradiated with microwaves at an oscillation output of 2.45 GHz and stirred at 60 ° C. for 30 minutes to obtain conductive fine particles (E-3) (silver layer thickness: 0.06 μm, specific gravity: 2. 6, volume average particle diameter 9.2 μm). When the conductive fine particles (E-3) were observed using an electron microscope (SEM), it was confirmed that a uniform and dense silver coating layer free of defects was formed.

Example 4 <Production of conductive fine particles (E-4)>
(1) Production of polymer fine particles (F-2) A mixed liquid of 80 parts of divinylbenzene, 20 parts of hydroxyethyl (meth) acrylate, 20 parts of trimethylolpropane tri (meth) acrylate and 2 parts of benzoyl peroxide was used as an oil phase. The oil phase was put into 800 parts of a 3% aqueous solution of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., GH-20), and granulated by stirring at 10,000 rpm using a homomixer. This was put into a reaction vessel equipped with a stirrer and a thermometer, heated to 80 ° C. under a nitrogen stream while stirring, and reacted for 15 hours. The resulting suspension was filtered, washed and classified to obtain polymer fine particles (F-2) obtained by covalently bonding a functional group hydroxyl group having a high metal affinity to the surface (volume average particle diameter 5.2 μm). ).
(2) Production of conductive fine particles (E-4) Microwave was added to 100 parts of a 5.5 wt% aqueous silver nitrate solution in which 2.5 parts of polymer fine particles (F-2) were kept at a liquid temperature of 60 ° C and dispersed. Was radiated at an oscillation output of 2.45 GHz, and 0.7 parts of dimethylethanolamine was added dropwise for 40 minutes while stirring to obtain conductive fine particles (E-4) (silver layer thickness: 0.07 μm, specific gravity). : 2.0, volume average particle diameter 5.2 μm). When the conductive fine particles (E-4) were observed using an electron microscope (SEM), it was confirmed that a uniform and dense silver coating layer free from defects or the like was formed.

Example 5 <Production of conductive fine particles (E-5)>
A microwave was oscillated at 2.45 GHz while maintaining the liquid temperature at 60 ° C. in 100 parts of ethylene glycol in which 2.5 parts of polymer fine particles (F-2) and 3.3 parts of tetrachloroauric (III) acid were dispersed. Irradiation was performed, and 3.5 parts of a 20% by weight aqueous solution of dimethylethanolamine was dropped for 40 minutes to obtain conductive fine particles (E-5) (gold layer thickness: 0.09 μm, specific gravity: 2.7, Volume average particle size 5.2 μm). When the conductive fine particles (E-5) were observed using an electron microscope (SEM), it was confirmed that a uniform and dense gold coating layer free from defects was formed.

Comparative Example 1 <Production of conductive fine particles (E′-1)>
Etching was performed by dispersing 10 g of polymer fine particles (A-1) in a pre-dip solution for powder plating (Okuno Pharmaceutical Co., Ltd.) and stirring at 30 ° C. for 30 minutes. After washing with water, it was added to 100 ml of a Pd catalyzed solution containing 1% by weight of palladium sulfate and stirred at 30 ° C. for 30 minutes to adsorb palladium ions to the particles. The particles were filtered and washed with water, and then added to a 0.5 wt% dimethylamine borane solution (adjusted to pH 6.0) to obtain polymer fine particles in which Pd was activated.
Distilled water (500 ml) was added to the obtained Pd-activated resin fine particles, and sufficiently dispersed using an ultrasonic processor to obtain a fine particle suspension. While stirring this suspension at 50 ° C., an electroless plating solution (pH adjusted to 7.5) consisting of 50 g / L of silver sulfate, 40 g / L of sodium hypophosphite, and 50 g / L of citric acid is gradually added. It was added and electroless silver plating was performed. When the metal coating layer became approximately 0.05 μm, the addition of the electroless plating solution was stopped, the alcohol was replaced, and then vacuum drying was performed to obtain silver-coated conductive epoxy resin fine particles (E′-1) (Ag Plating layer thickness: 0.10 μm, specific gravity: 1.55, volume average particle diameter 7.90 μm). When the silver-coated conductive epoxy resin fine particles (E′-1) were observed using an electron microscope (SEM), it was confirmed that a uniform metal coating layer having no plating defects was formed.

Comparative Example 2; <Production of conductive fine particles (E′-2)>
While stirring a suspension dispersed in 1 part of polymer fine particles (A-1) and 100 parts of ion-exchanged water by ultrasonic treatment, 100 parts of a 0.66% aqueous solution of gold fine particles (C-1) is added at room temperature. By continuing stirring for 3 minutes, conductive fine particles (E′-2) were obtained (specific gravity: 1.08, volume average particle size 5.21 μm). When the conductive fine particles (E′-2) were observed using an electron microscope (SEM), the gold fine particles (E′-2) did not adhere to the surface of the polymer fine particles (A-1), and the gold coating layer Was not formed.

  About the conductive fine particles (E-1 to E-4, E′-1 to E′-2) obtained above, the conductivity (contact resistance) and the adhesiveness of the conductive coating layer ( Conductivity breakdown ratio), conductivity after high-temperature and high-humidity load, etc. (contact resistance after load), and the amount of eluted ions were evaluated. The results are shown in Table 1.

<Contact resistance>
The sample was compressed using a micro-compressed electric resistance measuring instrument (PCT-200 modified, manufactured by Shimadzu Corporation), and the contact resistance value was measured when the particle size was compressed by 20%. This is the contact resistance initial value. This measurement was performed on 20 particles, and the average value was obtained.

<Conductive breakdown ratio>
Further, when the particles were gradually compressed to 50% of the average particle size, particles whose resistance value suddenly increased to 10Ω or more were observed in the process. When these particles were observed with an electron microscope (SEM), peeling and destruction of the conductive coating layer occurred, and the generation ratio of these particles was determined as the conductive breakdown ratio. It shows that the adhesiveness of a conductive coating layer is so high that this electroconductive fracture ratio is low.
<Contact resistance after loading>
The conductive fine particles were allowed to stand for 20 days in an atmosphere of 85 ° C. and 95% relative humidity, and then contact resistance values were determined in the same manner as in the above measurement. This is the contact resistance value after loading. The smaller the difference between the contact resistance value after loading and the initial contact resistance value, the more conductive fine particles have superior temporal stability.
<Elution ion amount>
1 g of conductive fine particles were precisely weighed, weighed into a well-washed quartz tube, 10 ml of distilled water (specific resistance 18 MΩ) was added, and the quartz tube was melt-sealed with a gas burner. After heating in an electric oven at 120 ° C. for 24 hours, the quartz tube is opened and the resulting extract is filtered through a 0.1 μm membrane filter. The halogen ions (chlorine ions) in this solution are subjected to ion chromatography. Then, metal ions (sodium ions) were measured by flameless atomic absorption spectrophotometry. Chlorine ions are derived from chloroauric acid at the time of production of gold fine particles (B-1) and a catalyst solution in the electroless plating process, and sodium ions are derived from sodium hypophosphite in the electroless plating process. It can be said that the smaller the amount of these eluted ions, the better the conductive fine particles are.

The conductive fine particles obtained by the production method of the present invention can be produced at a reduced cost, and have a feature that the metal coating layer is uniform and excellent in stability over time. From these characteristics, it is useful as conductive fine particles used for conductive pastes and anisotropic conductive materials used for electrode connection materials in connection of various electronic components, circuit forming materials, liquid crystal displays and the like.

Claims (5)

Polymer fine particles (A), compound (B) having a functional group (b) with high metal affinity, metal salt (C), solvent (D) having a relative dielectric constant ε of 20 to 90 at 25 ° C., and if necessary A method for producing conductive fine particles (E), comprising irradiating a mixture containing a reducing agent (G) with microwaves. The conductive particles according to claim 1, wherein the polymer fine particles (A) are dispersed in the solvent (D) in which the compound (B), the metal salt (C), and, if necessary, the reducing agent (G) are dissolved, and are irradiated with microwaves. Method for producing fine particles (E). Polymer fine particles (F) having a functional group (b) having a high metal affinity on the surface, a metal salt (C), a solvent (D) having a relative dielectric constant ε of 20 to 90 at 25 ° C., and a reducing agent if necessary A process for producing conductive fine particles (E), wherein the mixture containing G) is irradiated with microwaves. The method for producing conductive fine particles (E) according to claim 3, wherein the fine polymer particles (F) are polymer fine particles obtained by covalently bonding a functional group (b) having a high metal affinity to the surface. In a solvent (D) in which a metal salt (C) and, if necessary, a reducing agent (G) are dissolved, fine polymer particles (F) having a functional group (b) having a high metal affinity on the surface are dispersed, and microwaves are dispersed. The manufacturing method of the electroconductive fine particles (E) of Claim 3 or 4 irradiated.