JP2010083954A - Polymer microparticle, method for manufacturing the same, and electroconductive microparticle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a polymer microparticle which has a thin layer on the surface of a core particle, a small average-particle diameter and a uniform particle-size distribution, and the layer of which is flat and of a uniform thickness and high coverage; a method for manufacturing the same; and an electroconductive microparticle using the same. <P>SOLUTION: This polymer microparticle is a polymer microparticle which has a polymetalloxane layer containing a metal atom M on the surface of a Si atom-containing core particle P, wherein the core particle P has the surface bonded with the polymetalloxane layer by means of a structure containing -Si-O-M-. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to polymer fine particles, a method for producing polymer fine particles, and conductive fine particles.

  Methods for modifying the particle surface include (1) a coating method for coating the surface, (2) a mechanochemical method utilizing a mechanical action, and (3) a chemical surface modification method utilizing a chemical reaction, etc. It has been known.

  However, a method for efficiently forming a thin film on the surface of fine particles having a small average particle diameter is not known.

  The coating method is a surface modification method for relatively large particles. For this reason, there is a problem that it is difficult to efficiently form a thin film on the particle surface of the fine particles by the coating method.

  The mechanochemical method can target fine particles having a small average particle size. However, since the mechanical action is used, there are a problem that the formed film is not smooth, a problem that it is difficult to form a thin film, and a problem that it is difficult to form a film having a high coverage (for example, Patent Document 1). 2).

The chemical surface modification method can target fine particles having a small average particle diameter, and may form a thin film. However, there is a problem that it is difficult to form a film having a high coverage, a problem that it is difficult to form a film having a uniform thickness, and a problem that it is difficult to form fine particles having a uniform particle size distribution (see, for example, Patent Document 3). .
JP 62-83029 A Japanese Patent Laid-Open No. 5-170924 JP 2004-307837 A

  An object of the present invention is a polymer fine particle having a thin coating on the surface of the core particle, the average particle diameter is small, the coating is smooth, the coating thickness is uniform, the coating coverage is high, and the particle size The object is to provide polymer fine particles having a uniform distribution. Another object of the present invention is to provide a method for producing such polymer fine particles. Furthermore, it is providing the electroconductive fine particle using such a polymer microparticle.

The polymer fine particles of the present invention are polymer fine particles having a polymetalloxane coating containing a metal atom M on the surface of a core particle P containing Si atoms, and the polymetalloxane coating is on the surface of the core particle P— They are bonded by a structure containing Si-OM-.
In a preferred embodiment, the polymetalloxane film is a polysiloxane film containing a metal atom Si.
In a preferred embodiment, the polymer fine particles have an average particle size of 0.5 to 100 μm.
In a preferred embodiment, the polymetalloxane coating has a coverage of 100%.
In a preferred embodiment, the polymetalloxane coating has a thickness of 1 to 500 nm, and the thickness is substantially uniform on the surface of the core particle P.
According to another aspect of the present invention, a method for producing polymer fine particles is provided. The production method of the present invention is a method for producing polymer fine particles having a polymetalloxane coating containing a metal atom M on the surface of a core particle P containing Si atoms, the core particle precursor having a -Si-OH group on the surface A hydrolyzable organometallic compound or a condensate obtained by hydrolyzing at least a part of the hydrolyzable organometallic compound is added to the solvent in which the body P ′ is dispersed to perform a hydrolysis reaction and / or a condensation reaction.
In a preferred embodiment, the polymetalloxane film is a polysiloxane film containing a metal atom Si.
In a preferred embodiment, the hydrolyzable organometallic compound is a metal alkoxide represented by the general formula MXn (where M is a metal atom having a valence of n and X is an alkoxy group).
In a preferred embodiment, the hydrolyzable organometallic compound is an organosilicon compound represented by the general formula R ¹ pSiY ¹ q (where R ¹ is a hydrocarbon group which may have a substituent). Y ¹ is an —OH group, —OR ² group, a halogen atom, or a hydrogen atom, R ² is an alkyl group, an acyl group, an aryl group, or an aralkyl group, and p and q satisfy p + q = 4 Is an integer).
According to another aspect of the present invention, conductive fine particles are provided. The conductive fine particles of the present invention include the polymer fine particles of the present invention and a metal layer.
In a preferred embodiment, the metal layer is a layer formed by an electroless plating method.

  According to the present invention, polymer fine particles having a thin coating on the surface of the core particles, the average particle diameter is small, the coating is smooth, the coating thickness is uniform, the coating coverage is high, and the particle size Polymer fine particles having a uniform distribution can be provided. In addition, a method for producing such polymer fine particles can be provided. Furthermore, conductive fine particles using such polymer fine particles can be provided.

[Production method of polymer fine particles]
The method for producing polymer fine particles of the present invention is a method for producing polymer fine particles having a polymetalloxane coating containing a metal atom M on the surface of a core particle P containing Si atoms, wherein a -Si-OH group is formed on the surface. A hydrolyzable organometallic compound or a condensate obtained by hydrolyzing at least a part thereof is added to an organic solvent in which the core particle precursor P ′ is dispersed, and a hydrolysis reaction and / or a condensation reaction is performed.

The core particle precursor P ′ having a —Si—OH group on the surface can be produced by any appropriate method. The core particle precursor P ′ preferably has a Si—OH group or a group capable of forming a Si—OH group by hydrolysis, and polymerizes a silicon compound and / or a polysiloxane compound having a polymerizable unsaturated bond. Can be obtained.
Here, as the group capable of forming a Si—OH group by the hydrolysis described above, an OR group (R: alkyl group, acyl group, aryl group, aralkyl group), a halogen atom, and a hydrogen atom are preferable. An alkoxy group in which is an alkyl group is more preferred. That is, the polymerization is preferably performed in the presence of a compound represented by R ³ rSiZs, which will be described later, or a polysiloxane compound comprising a hydrolysis condensate of the compound.
In the above-mentioned production method, since the silicon compound or polysiloxane has a polymerizable unsaturated bond, it can be polymerized alone or in the presence of a monomer having a polymerizable unsaturated bond. The core particle precursor P ′ can be obtained.
In the above-described production method, examples of polymerization forms include suspension polymerization, emulsion polymerization, seed polymerization, sol-gel polymerization, sol-gel seed polymerization, dispersion polymerization, and precipitation polymerization. For example, when it is performed by sol-gel seed polymerization, it is possible to reduce the coefficient of variation (CV value) of the particle diameter of the finally obtained polymer fine particles, and it can be used as a gap holding material that makes the gaps between various substrates uniform. When used in the above, an advantageous effect of keeping the gap distance uniform can be exhibited.
Specific examples of the method for producing the core particle precursor P ′ having a —Si—OH group on the surface include the following (Method 1) to (Method 4). In addition, when producing the core particle precursor P ′ having —Si—OH group on the surface, when the core particle precursor P ″ having alkoxysilyl group on the surface is first obtained, polymetalloxane coating is performed. Prior to the reaction for this, it is preferred to convert the alkoxysilyl group to -Si-OH group by any suitable method.

(Method 1) Compound represented by R ³ rSiZs (wherein R ³ is a hydrocarbon group having a group containing a polymerizable unsaturated bond) and / or a condensate and a polymerizable monomer at least partly hydrolyzed To polymerize a mixture with.
Preferable specific polymerization forms of Method 1 include suspension polymerization method, dispersion polymerization method, and precipitation polymerization method.

(Method 2) After hydrolyzing and condensing a compound represented by R ³ rSiZs (where R ³ is a hydrocarbon group having a group containing a polymerizable unsaturated bond) in a water-containing organic solvent to form polysiloxane particles, A method of polymerizing after absorbing a polymerizable monomer.
A preferred specific form of polymerization in Method 2 is a sol-gel seed polymerization method.

(Method 3) A compound represented by R ³ rSiZs (where R ³ is a hydrocarbon group having a group containing a polymerizable unsaturated bond) is hydrolytically condensed in a water-containing organic solvent to obtain polymerizable polysiloxane particles. A method of polymerizing later.
A preferred specific form of polymerization in Method 3 is a sol-gel polymerization method.

(Method 4) Hydrolysis condensate (that is, polymerizable polysiloxane) of a compound represented by R ³ rSiZs (where R ³ is a hydrocarbon group having a group containing a polymerizable unsaturated bond) in an aqueous medium How to polymerize.
Preferable specific polymerization forms of Method 4 include suspension polymerization, emulsion polymerization, dispersion polymerization, and precipitation polymerization.

In the above (Method 1) and (Method 2), R ³ is a hydrocarbon group having a group containing a polymerizable unsaturated bond. Examples of the group containing a polymerizable unsaturated bond include a vinyl group and a (meth) acryloxy group. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an aryl group, and an aralkyl group.

In the above (Method 3) and (Method 4), R ³ is a hydrocarbon group having a group containing a polymerizable unsaturated bond. Examples of the group containing a polymerizable unsaturated bond include a vinyl group and a (meth) acryloxy group. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an aryl group, and an aralkyl group.

In the above (Method 1) to (Method 4), Z is any one of —OH group, —OR ⁴ group, halogen atom, and hydrogen atom, and R ⁴ is an alkyl group, acyl group, aryl group, aralkyl group. It is. The Z is preferably an —OH group, an —OR ⁴ group and a group in which R ⁴ is an alkyl group having 1 to ⁴ carbon atoms, and a —OR ⁴ group and a group in which R ⁴ is an acetyl group.

  In the above (Method 1) to (Method 4), r and s are integers satisfying r + s = 4, preferably, r is an integer of 1 to 3, and more preferably, r is 1 or 2. .

  In the above (Method 1) and (Method 2), any appropriate monomer can be adopted as the polymerizable monomer as long as it is a monomer having a polymerizable unsaturated bond. Examples thereof include styrene and divinylbenzene.

  In the above (Method 1) to (Method 4), any appropriate polymerization form can be adopted as the form of the polymerization. Examples thereof include suspension polymerization, seed polymerization, dispersion polymerization, and sol-gel seed polymerization. Suspension polymerization and sol-gel seed polymerization are preferable, and sol-gel seed polymerization is more preferable. When the sol-gel seed polymerization is performed, it is possible to reduce the coefficient of variation (CV value) of the particle diameter of the finally obtained polymer fine particles, and the conductivity is uniform when used as a raw material for the conductive fine particles. When fine particles are obtained and electrical connection between the electrodes using the conductive fine particles is performed, an advantageous effect that connection reliability is increased can be exhibited.

  In the method for producing polymer fine particles of the present invention, only one type of core particle precursor P ′ having a —Si—OH group on the surface may be used, or two or more types may be used in combination.

  More specifically, the core particle precursor P ′ having —Si—OH groups on the surface may be organic-inorganic composite particles. The organic-inorganic composite particle referred to in the present invention is a composite particle essentially comprising an inorganic skeleton that is an inorganic component and a vinyl polymer that is an organic component, and the inorganic skeleton is silicon having a (meth) acryloxy group. A skeleton composed of a polysiloxane skeleton structure obtained by hydrolyzing and condensing an inorganic compound raw material essential for a compound, that is, a polysiloxane skeleton structure having a (meth) acryloxy group, and constituting this inorganic skeleton Particles containing a vinyl polymer therein, that is, particles in which a vinyl polymer is present between the polysiloxane skeletons.

  The organic-inorganic composite particles referred to in the present invention include particles in which most of the organic components are coated on the surfaces of the inorganic particles, particles in which the organic components are grafted on the surfaces of the inorganic particles, and organic portions and inorganic portions. It differs in form from particles obtained by polymerizing a polymerizable monomer. The organic-inorganic composite particles referred to in the present invention are particles having excellent mechanical properties such as hardness and breaking strength, and can be controlled to have a desired particle size and particle size distribution because of the above-described configuration. In obtaining organic / inorganic composite particles, it is preferable to produce particulate matter (inorganic particles) composed of the inorganic skeleton.

  As the shape of the inorganic particles, any appropriate particle shape such as a spherical shape, a needle shape, a plate shape, a scale shape, a pulverized shape, a bowl shape, an eyebrows shape, a confetti shape and the like can be adopted.

  The average particle diameter of the inorganic particles is preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm, and most preferably 1 to 30 μm. When the average particle diameter of the inorganic particles is within the above range, it is possible to exert an advantageous effect that absorption of a polymerizable monomer described later proceeds efficiently.

  The sharpness of the particle size distribution of the inorganic particles can be indicated by a coefficient of variation (CV value). The coefficient of variation (CV value) is preferably 20% or less, more preferably 10% or less, and most preferably 5% or less. When the coefficient of variation (CV value) is within the above range, an advantageous effect that the polymerizable monomer described later can be efficiently absorbed can be exhibited.

The sol-gel seed polymerization method (preferred form of Method 2), which is a preferable method for producing the organic-inorganic composite particles described above, will be described below.
It is preferable that the polysiloxane particle | grains which have the (meth) acryloxy group which are the said inorganic particles are obtained by the method including the condensation process shown below, for example. The condensation step is a step of hydrolysis and condensation using a hydrolyzable silicon compound group essentially comprising a hydrolyzable silicon compound having a (meth) acryloxy group. In this condensation step, ammonia or the like is used as a catalyst. A basic catalyst may be used.

In the hydrolyzable silicon compound group, a hydrolyzable silicon compound having a (meth) acryloxy group represented by the following general formula (1) (hereinafter sometimes referred to as silicon compound (1)) is an essential component. If necessary, a silicon compound represented by the following general formula (2) (hereinafter sometimes referred to as silicon compound (2)) may be used in combination. Moreover, you may use together the derivative | guide_body of the said silicon compounds (1) and (2) with the said silicon compound (1).
(Here, R ^a represents a hydrogen atom or a methyl group, R ^b represents an optionally substituted divalent organic group having 1 to 20 carbon atoms, and R ^c represents a hydrogen atom or carbon number. And at least one monovalent group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms and an acyl group having 2 to 5 carbon atoms, wherein R ^d is selected from the group consisting of an alkyl group having 1 to 5 carbon atoms and a phenyl group. Represents at least one monovalent group selected, h is 1 or 2, and i is 0 or 1.)
(Wherein, ^{R e} is composed of an alkyl group, an alkenyl group having 2 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms having 1 to 20 carbon atoms having an alkyl group, an epoxy group having 1 to 20 carbon atoms At least one monovalent group selected from the group, wherein R ^f is at least one monovalent group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and an acyl group having 2 to 5 carbon atoms. (J is an integer of 1 to 3)

  Specific examples of the silicon compound (1) include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, and γ-acryloxypropyltriethoxysilane. , Γ-methacryloxypropyltriacetoxysilane, γ-methacryloxyethoxypropyltrimethoxysilane (also referred to as γ-trimethoxysilylpropyl-β-methacryloxyethyl ether), γ-methacryloxypropylmethyldimethoxysilane, γ- Examples thereof include methacryloxypropylmethyldiethoxysilane and γ-acryloxypropylmethyldimethoxysilane. These may be used alone or in combination of two or more.

  Specific examples of the silicon compound (2) include tetrafunctional silanes such as tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraacetoxysilane, etc., where n = 0. Silane: methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, methyltriacetoxysilane, vinyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltri A trifunctional silane in which n = 1 in the above general formula (2) such as methoxysilane, 3,4-epoxybutyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane; Dimethyldimethoxysilane, dimethyl And the like can be given; diethoxysilane, diacetoxy dimethyl silane, difunctional silane of n = 2 in the above general formula such as diphenyl disilane diol (2). These may be used alone or in combination of two or more.

Derivatives of silicon compound (1) and (2), specifically, for example, a silicon compound (1) and (2) at least one of which with respect to OR ^c group or OR ^f group containing the β- dicarbonyl group And / or a low-condensate obtained by partially hydrolyzing and condensing a compound substituted with a group capable of forming another chelate compound and the silicon compounds (1) and (2) and / or the chelate compound And at least one selected from the group consisting of:

  The inorganic particles (polysiloxane particles) are obtained by hydrolyzing and condensing the silicon compound group in a solvent containing water. About hydrolysis and condensation, arbitrary appropriate methods, such as lump, division | segmentation, and a continuation, can be employ | adopted. In the hydrolysis and condensation, a catalyst such as ammonia, urea, ethanolamine, tetramethylammonium hydroxide, alkali metal hydroxide, or alkaline earth metal hydroxide may be used. Further, in the solvent, an organic solvent may be present in addition to water and the catalyst.

  Specific examples of the organic solvent include methanol, ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, pentanol, ethylene glycol, propylene glycol, 1,4-butanediol, and the like. Alcohols such as acetone and methyl ethyl ketone; esters such as ethyl acetate; (cyclo) paraffins such as isooctane and cyclohexane; ethers such as dioxane and diethyl ether; aromatic hydrocarbons such as benzene and toluene; Etc. are preferred. These may be used alone or in combination of two or more.

  In the hydrolysis and condensation, for example, the silicon compound group and an organic solvent are added to a solvent containing water, preferably in the temperature range of 0 to 100 ° C., more preferably in the temperature range of 0 to 70 ° C., preferably 30 minutes. It is carried out by stirring for ~ 100 hours. In addition, inorganic particles can be obtained by previously preparing particles obtained as described above as seed particles in a synthesis system and adding the silicon compound group thereto to grow the seed particles. . In this way, the silicon compound group is hydrolyzed and condensed under any appropriate conditions in a solvent containing water, whereby particles are precipitated and a slurry is generated. Since the precipitated particles are obtained by using the silicon compound (1) having the (meth) acryloxy group described above as an essential component, polysiloxane particles having a (meth) acryloxy group can be obtained.

  Arbitrary appropriate conditions for performing the hydrolysis and condensation are, for example, in the obtained slurry, the concentration of the silicon compound (1) and the silicon compound (2) is 20% by weight or less, the water concentration is 50% or more, Conditions such that the catalyst concentration is 10% by weight or less are preferred.

  Any appropriate conditions for carrying out the hydrolysis and condensation are more preferably 50 to 99.99% by weight of water, 0.01 to 10% by weight of catalyst, and 0 to 90% by weight of organic solvent. %, The concentration of the silicon compound group is 0.1 to 30% by weight, the addition time of the silicon compound group is 0.001 to 500 hours, and the reaction temperature is 0 to 100 ° C. The concentration of the seed particles is preferably set to 0 to 10% by weight.

  Since the inorganic particles are obtained by using the silicon compound group as a raw material inorganic compound as described above, the inorganic particles include an inorganic portion (polysiloxane skeleton) derived from silicon atoms in the inorganic compound, and (meta) It has an organic group such as an acryloxy group.

  The inorganic particles are particles that can easily absorb and retain a polymerizable monomer described later in the particles, that is, between the polysiloxane skeletons constituting the particles. This is because the (meth) acryloxy group possessed by the inorganic particles is very compatible with organic compounds such as polymerizable monomers, and the inorganic particles absorb the polymerizable monomers. It can be said that this is because of a suitable degree of crosslinking. This polymerizable monomer finally becomes a vinyl polymer which is an organic component.

  The polymerizable monomer may be a compound containing at least one ethylenically unsaturated group in the molecule. Specifically, for example, monomers having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate; methoxypolyethylene glycol (meth) acrylate Monomers having a polyethylene glycol component such as, butyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, isoamyl acrylate, lauryl (meth) acrylate, benzyl methacrylate, methacryl Alkyl (meth) acrylates such as tetrahydrofurfuryl acid; trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, pentanefluoropropyl (meth) acrylate, octafluoroamyl (meth) acrylate, etc. Elemental atom-containing (meth) acrylates; aromatic vinyl compounds such as styrene, α-methylstyrene, vinyl tolman, α-chlorostyrene, 0-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-ethylstyrene; glycidyl (Meth) acrylate; (meth) acrylic acid; (meth) acrylamide; (meth) acrylonitrile;

  The said polymerizable monomer may be used independently and may use 2 or more types together.

When the polymerizable monomer is absorbed by the inorganic particles, for example, when the polymerizable monomer is preliminarily emulsified and dispersed to form an emulsion, a hydrophobic polymerizable monomer is preferably used in order to obtain a stable emulsion. Can be used.
When the polymerizable monomer is absorbed, it is preferable to contain a radical polymerization initiator in the emulsion obtained by emulsification and dispersion. The amount of the polymerization initiator is usually preferably 0.01 to 10% by weight with respect to the total amount of polymerizable monomers. As the polymerization initiator, a conventionally known radical polymerization initiator can be used.

In order to easily adjust the effect on the mechanical properties of the obtained core particle precursor P ′, a crosslinkable monomer may be used. Examples of the crosslinkable monomer include divinylbenzene, (poly) ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meta) ) Acrylate, tetramethylol methane tri (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, dipentaerythritol hexaacrylate, diallyl phthalate and isomers thereof, triallyl isocyanurate and derivatives thereof, and the like. These may be used alone or in combination of two or more.
The above-mentioned polymerizable monomer, preferably an emulsion emulsified and dispersed, is mixed with a slurry in which inorganic particles (polysiloxane particles) are dispersed, and preferably polymerized to inorganic particles by stirring for 0.1 to 5 hours. A composite particle precursor formed by absorbing the functional monomer is formed. The temperature at the time of absorption is preferably 50 ° C. or less, more preferably 40 ° C. or less, and further preferably 10 to 40 ° C. from the point that polymerization of the polymerizable monomer is difficult to start in the absorption process.
A slurry in which the organic / inorganic composite particles preferable as the core particle precursor P ′ in the present invention are dispersed by heating and holding the slurry in which the composite particle precursor is dispersed at a polymerizable temperature, preferably 50 ° C. or higher. Is obtained. Although the said polymerization temperature is based also on the polymerization initiator to be used, it is preferable to carry out normally at 60-100 degreeC. The heating and holding time is usually preferably 0.1 to 10 hours.

  In the above-described organic-inorganic composite particle production method, polysiloxane particles obtained by hydrolysis / condensation using a silicon compound having a polymerizable unsaturated bond as an essential component are similarly obtained, and then the polymerizable monomer is absorbed. Alternatively, organic-inorganic composite particles can also be obtained by radical polymerization (a preferred form of Method 3). Specifically, it is achieved by heating a slurry composed of the polymerizable polysiloxane particles, preferably in the presence of a radical polymerization initiator. Alternatively, it can also be achieved by isolating polymerizable polysiloxane particles from the slurry and heating in the gas phase.

The organic-inorganic composite particles preferable as the core particle precursor P ′ in the present invention also have a silicon compound having a polymerizable unsaturated bond having a Si—OH group or a group capable of forming a Si—OH group by hydrolysis, and It can also be obtained by a method (suspension polymerization method) in which a polymerizable monomer composition obtained by mixing a polysiloxane compound with a polymerizable monomer is suspended in an aqueous medium and heated (preferred form of Method 1). . As a silicon compound having a Si—OH group or a group capable of forming a Si—OH group by hydrolysis and having a polymerizable unsaturated bond, a compound represented by the above R ³ rSiZs (provided that R ³ is polymerizable) It is preferable to use a hydrocarbon group having a group containing an unsaturated bond. As the polysiloxane compound having a polymerizable unsaturated bond, it is preferable to use a condensate obtained by hydrolysis and condensation of the above compound. Among them, in order to obtain a suspension composed of stable droplets of the polymerizable monomer composition described above and to obtain organic-inorganic composite particles having no aggregation, it is represented by R ³ rSiZs where Z is an alkoxy group. It is preferable to use a compound (wherein R ³ is a hydrocarbon group having a group containing a polymerizable unsaturated bond). Further, the polymerizable monomer composition preferably contains a polymerization initiator in an amount of 0.01 to 10% by weight with respect to 100% by weight of the composition. A conventionally known method can be adopted as the suspension polymerization method. Although the heating temperature for superposition | polymerization is based also on the polymerization initiator to be used, 60-100 degreeC is preferable normally. The heating and holding time is usually preferably from 0.1 to 10 hours.
In the case of the organic-inorganic composite particles obtained by the suspension polymerization method described above, in particular, a compound represented by R ³ rSiZs in which Z is an alkoxy group as a silicon compound (provided that R ³ is a group containing a polymerizable unsaturated bond). In the case of using a hydrocarbon group having a hydroxyl group, it is preferable to perform a treatment for converting an alkoxysilyl group into a Si—OH group because the state of the alkoxy group remains in the obtained particles. This treatment is preferable because a polymetalloxane formation reaction occurs selectively on the particle surface in the formation reaction of the polymetalloxane film, and a film formation with excellent uniformity is performed.
Since particles obtained by the suspension polymerization method generally have a broad particle size distribution, it is preferable to classify the particles to obtain particles having a uniform particle size distribution.
The treatment for converting alkoxysilyl groups into Si—OH groups can be achieved, for example, by immersing the particles in a basic or acidic aqueous medium. Preferably, a heat treatment is further performed. For example, a method in which alkali metal, alkaline earth metal hydroxide or carbonate, ammonia, amine, etc. are added to the slurry of organic-inorganic composite particles after suspension polymerization, adjusted to basic, and then heated, etc. Can be adopted. Although depending on the heating temperature and heating time, in order to perform the treatment at an economical temperature and time, it is preferable that the pH of the aqueous medium is 9 or more when adjusting to basic, 10 or more. More preferably, it is more preferably 10 to 11.8. When adjusting to acidity, the pH of the aqueous medium is preferably 5 or less, more preferably 4.5 or less, and preferably 2 to 4.5. Further preferred. In order to perform only the conversion reaction from the alkoxy group to the Si-OH group without impairing the mechanical strength characteristics of the polymer particles, it is preferably performed under basic conditions, and the compound used for pH adjustment can be easily removed. From this point, it is preferable to adjust the basicity using ammonia. The heating temperature is preferably 10 to 100 ° C. in order to be industrially inexpensive. The heating and holding time is preferably 0.1 to 10 hours in order to be industrially inexpensive. Moreover, it is preferable to carry out under stirring. In addition, the process which converts an alkoxy silyl group into a Si-OH group is not necessarily performed only on particles obtained by a suspension polymerization method, and may be employed on particles obtained by other methods described above.

The organic-inorganic composite particles are particles in which a vinyl polymer is contained in an inorganic skeleton structure. The average particle diameter of the organic-inorganic composite particles is an average particle diameter in a state where the vinyl polymer is included in the skeleton structure of the inorganic particles and combined as described above, and specifically, preferably Is 0.1 to 200 μm, more preferably 0.5 to 100 μm, and even more preferably 1 to 50 μm. When the average particle size is within the above range, the ratio of the inorganic component derived from the inorganic particles and the organic component derived from the vinyl polymer can be widely changed, for example, the same average particle size However, advantageous effects such as various changes in mechanical properties such as particle hardness and breaking strength can be exhibited.
The organic-inorganic composite particles can have a desired particle diameter by adjusting the amount of the vinyl polymer contained in the structure of the inorganic particles. The sharpness of the particle size distribution of the organic-inorganic composite particles is indicated by a coefficient of variation (CV value) of the particle diameter, and specifically, preferably 20% or less, more preferably 10% or less, and even more preferably 5%. It is as follows. When the coefficient of variation (CV value) is within the above range, for example, when used as a raw material for conductive fine particles, conductive fine particles having a uniform particle diameter are obtained, and between the electrodes using the conductive fine particles. When electrical connection is performed, an advantageous effect that connection reliability is increased can be exhibited.
In the organic-inorganic composite particles, the (meth) acryloxy group of the inorganic skeleton may be present in a single form, or at least one of them may be bonded to another reactive group and / or polymer. Also good. Examples of the bonded form include a form bonded to a vinyl polymer, a form bonded or polymerized by reacting with at least one other reactive group in the inorganic skeleton, and a vinyl type in this form. The form etc. which are couple | bonded with the polymer are mentioned. Among these, in the case of a form bonded to a vinyl polymer, the vinyl polymer is more firmly fixed in the structure of the inorganic skeleton, and the composition ratio of the vinyl polymer and the inorganic component, which are organic components, In addition, it is possible to maintain the desired particle diameter and sharpness of the particle size distribution more reliably and to have stable mechanical characteristics for a long period of time. Similarly, the above bonding can make the shape of the polymer particles more nearly spherical.

As for the hardness of the organic-inorganic composite particles, for example, a 10% compression elastic modulus is preferably 1000 N / mm ² or more, more preferably 2000 N / mm ² or more, and further preferably 3000 N / mm ² or more.

  The breaking strength of the organic-inorganic composite particles is, for example, preferably 1 mN or more, more preferably 3 mN or more, and further preferably 5 mN or more.

In the organic-inorganic composite particles, the amount of SiO ₂ which constitutes the polysiloxane backbone derived from inorganic backbone, for example, preferably 0.1 to 80 wt%, more preferably 0.5 to 70 wt%, more preferably 1.0 to 60% by weight.

  In order to confirm that the organic-inorganic composite particles are particles in which a vinyl polymer is contained in a three-dimensional network structure composed of an inorganic skeleton composed of a polysiloxane skeleton having a (meth) acryloxy group. Although the method can be applied, for example, the obtained particles are subjected to heat extraction with an organic solvent such as toluene, and the particle size and weight of the particles are not changed before and after the heat extraction, whereby the vinyl polymer is formed with an inorganic skeleton. A method for confirming that it is incorporated inside (in the structure) of a three-dimensional network structure, or a three-dimensional network formed with an inorganic skeleton by cutting the obtained particles and observing the cross section Examples thereof include a method for confirming that a vinyl polymer is contained in the structure (in the structure).

The shape of the organic-inorganic composite particles is not particularly limited, and specifically, for example, spherical, needle-like, plate-like, flaky, crushed, uneven, eyebrows, candy sugar, etc. Can be mentioned.
The organic-inorganic composite particles are preferably characterized in that at least one of silicon atoms constituting the polysiloxane skeleton has a Si—OH group.

Hereinafter, a method for forming a polymetalloxane coating will be described.
Any appropriate hydrolyzable organometallic compound may be employed as the hydrolyzable organometallic compound. Specifically, for example, a metal alkoxide represented by the general formula MXn (where M is a metal atom having a valence of n and X is an alkoxy group), and represented by a general formula R ¹ pSiY ¹ q Organosilicon compound (wherein R ¹ is a hydrocarbon group which may have a substituent, Y ¹ is any ^one of —OH group, —OR ² group, halogen atom and hydrogen atom, and R ² is An alkyl group, an acyl group, an acetyl group, an aryl group, and an aralkyl group, and p and q are integers satisfying p + q = 4).

  In the metal alkoxide MXn, M is a metal atom having a valence number n, preferably Si, Ti, Ar, or Al.

  In the metal alkoxide MXn, X is an alkoxy group, preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 5 carbon atoms, and still more preferably an alkoxy group having 1 to 3 carbon atoms. .

In the organosilicon compound R ¹ pSiY ¹ q, R ¹ is a hydrocarbon group which may have a substituent, preferably an alkyl group which may have a substituent, or a substituent. An alkenyl group which may have a substituent, an aryl group which may have a substituent, and an aralkyl group which may have a substituent.

In the organosilicon compound R ¹ pSiY ¹ q, Y ¹ is any ^one of —OH group, —OR ² group, halogen atom and hydrogen atom, and R ² is alkyl group, acyl group, acetyl group, aryl group, aralkyl. It is a group. Y ¹ is preferably an —OH group, —OR ² group and R ² is an alkyl group having 1 to 4 carbon atoms, —OR ² group and R ² is an acetyl group, and more preferably, An —OH group, —OR ² group and R ² is a methyl group (methoxy group), and —OR ² group and R ² is an ethyl group (ethoxy group).

In the organosilicon compound R ¹ pSiY ¹ q, p and q are integers satisfying p + q = 4, preferably, p is an integer of 0 to 3, more preferably p is an integer of 0 to 2. More preferably, p is 0.

In the organosilicon compound R ¹ pSiY ¹ q, it is also preferable to use a mixture of a compound with p = 0 and a compound with p = 1 or 2. In this case, the ratio of the compound of p = 0 and the compound of p = 1 or 2 is a molar ratio, preferably 10: 0 to 1: 9, more preferably 10: 0 to 5: 5, still more preferably 10 : 0 to 8: 2.

In the method for producing polymer fine particles of the present invention, only one kind of the hydrolyzable organometallic compound may be used, or two or more kinds may be used in combination. For example, only one kind of the metal alkoxide MXn may be used, two or more kinds of the metal alkoxide MXn may be used in combination, or only one kind of the organosilicon compound R ¹ pSiY ¹ q may be used, Two or more of the organosilicon compounds R ¹ pSiY ¹ q may be used in combination, or one or more of the metal alkoxides MXn and one or more of the organosilicon compounds R ¹ pSiY ¹ q may be used in combination. In particular, one or more of the above metal alkoxides MXn and the above organosilicon compound are used for adjusting the refractive index of the polymer fine particles of the present invention or adjusting the adhesion of the polymer fine particles of the present invention to a metal. It is a preferred form to use one or more of R ¹ pSiY ¹ q in combination.

  In the method for producing polymer fine particles of the present invention, a hydrolyzable organometallic compound or at least a part thereof is hydrolyzed in a solvent in which a core particle precursor P ′ having a —Si—OH group is dispersed on the surface. The condensation product is added to conduct a hydrolysis reaction and / or a condensation reaction.

  About the said hydrolysis reaction and condensation reaction, arbitrary appropriate methods, such as lump, a division | segmentation, and a continuation, can be employ | adopted. In performing the hydrolysis reaction and the condensation reaction, a catalyst such as ammonia, urea, ethanolamine, tetramethylammonium hydroxide, alkali metal hydroxide, or alkaline earth metal hydroxide may be used.

  Specific examples of the solvent include water; methanol, methanol, ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, pentanol, ethylene glycol, propylene glycol, 1,4- Alcohols such as butanediol; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; (cyclo) paraffins such as isooctane and cyclohexane; ethers such as dioxane and diethyl ether; aromatic carbonization such as benzene and toluene Preferred examples include hydrogens. These may be used alone or in combination of two or more.

  The hydrolysis reaction and the condensation reaction are preferably performed by stirring in a temperature range of 0 to 100 ° C., more preferably 10 to 70 ° C., and preferably 30 minutes to 100 hours.

  Any appropriate conditions for performing the hydrolysis and condensation are more preferably 0.01 to 10% by weight of catalyst concentration, 0.5 to 50% by weight of water concentration, and 1 to 1 concentration of solvent other than water. 90% by weight, concentration of core particle precursor P ′ is 0.1-30% by weight, addition time of hydrolyzable organometallic compound or condensate hydrolyzed at least partly is 0.001-500 hours The reaction temperature is 0 to 100 ° C.

(Polymer fine particles)
Preferably, the polymer fine particles of the present invention are obtained by the above production method. The polymer fine particles of the present invention are polymer fine particles having a polymetalloxane coating containing a metal atom M on the surface of a core particle P containing Si atoms, and the polymetalloxane coating is on the surface of the core particle P— They are bonded by a structure containing Si-OM-.

  In the polymer fine particles of the present invention, the polymetalloxane coating is composed of a skeleton formed by repeating any suitable metalloxane bond. A polysiloxane film containing a metal atom Si is preferable.

The polysiloxane film is a film represented by the general formula R ⁵ tY ² uSiOv.

In the polysiloxane coating R ⁵ tY ² uSiOv, R ⁵ is a hydrocarbon group which may have a substituent, preferably an alkyl group which may have a substituent, or a substituent. An alkenyl group which may have a substituent, an aryl group which may have a substituent, and an aralkyl group which may have a substituent.

In the polysiloxane coating R ⁵ tY ² uSiOv, Y ² is any one of —OH group, —OR ⁶ group, halogen atom and hydrogen atom, and R ⁶ is alkyl group, acyl group, acetyl group, aryl group, aralkyl. It is a group. Y ² is preferably an —OH group, —OR ⁶ group and R ⁶ is an alkyl group having 1 to 4 carbon atoms, —OR ⁶ group and R ⁶ is an acetyl group, and more preferably, An —OH group, —OR ⁶ group, R ⁶ is a methyl group (methoxy group), and —OR ⁶ group, R ⁶ is an ethyl group (ethoxy group).

In the polysiloxane coating R ⁵ tY ² uSiOv, t, u, and v are numbers satisfying v = (4-t−u) / 2.

In the polysiloxane coating ^R 5 ^tY 2 ^uSiOv, t is preferably 0 ≦ t <3, more preferably 0 ≦ t ≦ 2, more preferably 0 ≦ t ≦ 1, particularly preferably 0 ≦ t ≦ 0 .5.

In the polysiloxane film R ⁵ tY ² uSiOv, u is preferably 0 ≦ u <3, more preferably 0 <u ≦ 2.5, still more preferably 0 ≦ u ≦ 2, and particularly preferably 0 ≦ u. ≦ 1.5.

  The average particle diameter of the polymer fine particles of the present invention is preferably 0.5 to 100 μm, more preferably 1 to 30 μm, and still more preferably 2 to 20 μm. If the average particle size of the polymer fine particles of the present invention is out of the above range, the effects of the present invention may not be sufficiently exhibited.

  In the polymer fine particles of the present invention, the coefficient of variation (CV value) of the particle diameter is preferably 35% or less, more preferably 30% or less, still more preferably 25% or less, still more preferably 20% or less, particularly preferably. 10% or less, most preferably 5% or less. When the coefficient of variation (CV value) is within the above range, for example, when used as a raw material for conductive fine particles, conductive fine particles having a uniform particle diameter are obtained, and between the electrodes using the conductive fine particles. When electrical connection is performed, an advantageous effect that connection reliability is increased can be exhibited.

  In the polymer fine particles of the present invention, the coverage of the polymetalloxane coating (ratio of the portion where the outer surface of the core particle P is not exposed in the entire surface of the polymer fine particles of the present invention) is preferably 50%. Above, more preferably 80% or more, still more preferably 95% or more, particularly preferably 100%. If the coverage of the polymetalloxane coating is out of the above range, the effects of the present invention may not be sufficiently exhibited.

  In the polymer fine particles of the present invention, the thickness of the polymetalloxane coating is preferably 1 to 500 nm, more preferably 5 to 400 nm, and still more preferably 10 to 300 nm. When the thickness of the polymetalloxane coating is out of the above range, the effects of the present invention may not be sufficiently exhibited. Moreover, when the thickness of the polymetalloxane coating is too small, the chemical stability of the polymetalloxane coating may be lowered, and the surface hardness may not be sufficiently secured. On the other hand, if the thickness of the polymetalloxane coating is too large, cracks, cracks and peeling based on the difference in thermal expansion coefficient from the core particles P during heating and cooling may occur.

  In the polymer fine particle of the present invention, it is preferable that the thickness of the polymetalloxane coating is substantially uniform on the surface of the core particle P. When the thickness of the polymetalloxane coating is substantially uniform on the surface of the core particle P, the effects of the present invention can be sufficiently exhibited. Here, “substantially uniform” means that the fluctuation of the thickness of the polymetalloxane coating in an arbitrary portion on the surface of the core particle P is preferably within ± 20%, more preferably ± 10. %, More preferably within ± 5%, most preferably within ± 3%.

[Conductive fine particles]
The conductive fine particles of the present invention include the polymer fine particles of the present invention and a metal layer. Preferably, the conductive fine particles of the present invention include the polymer fine particles of the present invention and a metal plating layer.

  Conventional metal-plated conductive fine particles have poor adhesion between the substrate particles and the metal plating layer, so that the substrate particles are made porous, or the surface of the substrate particles is uneven by etching. It is necessary to give an anchor effect. However, if the substrate particles are made porous or if irregularities are generated on the surface of the substrate particles by etching, the strength of the substrate particles is significantly reduced, and the substrate particles are destroyed when they are crimped to the electrode terminals. And there is a problem that it does not recover while being compressed and deformed, and conduction may become unstable. Moreover, when crimping | bonding to an electrode terminal, a metal plating layer is cracked or peeled, and there exists a problem that a connection defect generate | occur | produces and connection reliability falls.

  Since the conductive fine particles of the present invention have a polymetalloxane layer in which the base particles are uniformly formed, the hardness / softness suitable for the anisotropic conductive material is controlled, and the adhesion of the metal layer is excellent. For this reason, it can become electroconductive fine particles which are hard to be destroyed at the time of use.

  Arbitrary appropriate metals can be employ | adopted as a metal used for the said metal layer. For example, metals such as gold, silver, copper, platinum, iron, lead, aluminum, chromium, palladium, nickel, rhodium, ruthenium, antimony, bismuth, germanium, tin, cobalt, indium, nickel-phosphorus, nickel-boron, etc. These alloys are mentioned.

  The metal layer can be preferably formed by any appropriate plating method (see, for example, JP 2003-208813 A, JP 2005-325382 A, and JP 2007-184278 A). Specifically, for example, an electroless plating method; a displacement plating method; a method of coating a base particle (polymer fine particles of the present invention) with a metal powder alone or mixed with a binder; vacuum deposition, ion plating And physical vapor deposition methods such as coating and ion sputtering.

  In the present invention, among the above plating methods, the electroless plating method is preferable. This is because a conductive metal film in which the thickness of the conductive film is controlled can be formed without requiring a large-scale apparatus.

  In general, the electroless plating method includes three steps: (1) a hydrophilization step (etching), (2) a catalyst step, and (3) an electroless plating step. Since the polymer fine particles of the present invention have a polymetalloxane coating on the surface, it becomes possible to perform electroless plating without performing a hydrophilic step (etching).

  The hydrophilization step (etching) is performed in order to improve the adhesion of the metal plating layer by forming minute irregularities on the surface of the substrate particles. The hydrophilization step (etching) includes, for example, an oxidizing agent such as chromic acid, sulfuric acid-chromic acid mixed solution, permanganic acid solution; strong acid such as hydrochloric acid and sulfuric acid; strong alkaline solution such as sodium hydroxide and potassium hydroxide; Is used to form minute irregularities on the surface of the substrate particles.

  The catalyzing step is performed in order to form a catalyst layer that can serve as a starting point for the electroless plating step on the surface of the substrate particles. Any appropriate method can be adopted as a method of forming the catalyst layer. For example, it can be carried out using a catalytic reagent etc. commercially available for electroless plating. Examples of such commercially available catalyzing reagents include pink summers (manufactured by Nippon Kanisen Co., Ltd.) and red summers (manufactured by Nippon Kanisen Co., Ltd.). As a method for forming the catalyst layer, specifically, for example, after immersing the substrate particles in a solution composed of palladium chloride and tin chloride, a strong acid such as sulfuric acid or hydrochloric acid or a strong alkali solution such as sodium hydroxide is used. Method of activating and precipitating palladium on the surface of the base particle; Method of activating palladium with a solution containing a reducing agent such as dimethylamine borane after immersing the base particle in a palladium sulfate solution and precipitating palladium on the surface of the base particle And so on.

  In the electroless plating step, preferably, the base particles are sufficiently dispersed in an aqueous medium to prepare an aqueous slurry. Here, the base particles are preferably sufficiently dispersed in an aqueous medium. If the metal plating layer is formed in a state where the base particles are aggregated, the untreated surface may be exposed. Arbitrary appropriate dispersion methods can be employ | adopted for dispersion | distribution of a base particle. For example, normal stirring, high speed stirring, dispersion using a shearing dispersion device such as a colloid mill or a homogenizer, and the like can be mentioned. When dispersing, ultrasonic irradiation may be used in combination. Moreover, you may use dispersing agents, such as surfactant, in the case of dispersion | distribution. Next, the dispersion-treated substrate particle slurry is added to an electroless plating bath containing a metal salt, a reducing agent, a complexing agent, etc., and electroless plating is performed.

  As said metal salt, when using nickel salt, nickel chloride, nickel sulfate, nickel acetate, etc. are mentioned, for example.

  Examples of the reducing agent include sodium hypophosphite, dimethylamine borane, sodium borohydride, potassium borohydride, hydrazine and the like.

  Examples of the complexing agent include citric acid, hydroxyacetic acid, tartaric acid, malic acid, lactic acid, gluconic acid, carboxylates such as alkali metal salts and ammonium salts thereof, amino acids such as glycine, ethylenediamine, alkylamine, and the like. Aminic acid, ammonium compound, EDTA, pyrophosphoric acid (salt) and the like. Only 1 type may be used for the said complexing agent and it may use 2 or more types together.

  The pH of the plating bath in the electroless plating method is preferably 4-14.

  In the electroless plating method, when a slurry of base material particles is added, the reaction starts quickly and is accompanied by generation of hydrogen gas. The end of the electroless plating process in the electroless plating method ends when the generation of hydrogen gas is no longer recognized.

  Since the conductive fine particles of the present invention have a polymetalloxane layer in which the base particles (polymer fine particles of the present invention) are uniformly formed, the base particles and the metal layer are formed without performing surface chemical treatment such as etching. It has strong adhesion between the two. For this reason, it is excellent in various physical properties such as compressive strength and deformation recovery performance after compression, and electrical conductivity can be maintained without causing breakage or permanent deformation of the conductive fine particles even when a pressure-bonding process is performed.

  In the conductive fine particles of the present invention, the reason why strong adhesion is developed between the base particles (polymer fine particles of the present invention) and the metal layer is that the base particles (polymer fine particles of the present invention) Since the polymetalloxane layer is uniformly formed on the surface, it has a metalloxane bond on the surface. Therefore, various coordinating powers, ionic forces, etc. are caused at the interface between the base particle (polymer fine particles of the present invention) and the metal layer. It is presumed that a strong binding force occurs.

  The conductive fine particles of the present invention are suitable as a constituent material of an anisotropic conductive material. The anisotropic conductive material is used to electrically connect opposing substrates and electrode terminals in various forms.

  Any appropriate method can be adopted as a method of electrically connecting the electrodes using the anisotropic conductive material. For example, a method in which the conductive fine particles of the present invention are dispersed in an insulating binder resin to produce an anisotropic conductive adhesive, and then the anisotropic conductive adhesive is connected; the insulating binder resin and the book And a method of connecting the conductive fine particles of the invention separately.

  Any appropriate binder resin can be adopted as the binder resin. For example, thermoplastic resins such as acrylate resins, ethylene-vinyl acetate resins, styrene-butadiene block copolymers; curable resin compositions obtained by reaction with curing agents such as monomers and oligomers having glycidyl groups and isocyanate Examples thereof include a curable resin composition by light and heat.

  Any appropriate anisotropic conductive adhesive can be adopted as the anisotropic conductive adhesive. For example, an anisotropic conductive film, an anisotropic conductive paste, an anisotropic conductive ink, etc. are mentioned. For example, the anisotropic conductive film is made into a solution by adding a solvent to the anisotropic conductive adhesive, and after pouring the solution onto the release film, the solvent is evaporated to coat the anisotropic conductive adhesive. It is obtained by making it into a shape. The obtained anisotropic conductive film is disposed on, for example, electrodes to be bonded, and is used for connection between the electrodes by superposing a counter electrode on the disposed anisotropic conductive film and compressing by heating. .

  The anisotropic conductive paste is obtained, for example, by making an anisotropic conductive adhesive into a paste. The obtained anisotropic conductive paste is put in, for example, a suitable dispenser, applied to a desired thickness on the electrode to be connected, and the counter electrode is superimposed on the coated anisotropic conductive paste. It is used for connection between electrodes by heating and pressurizing to cure the resin.

  The anisotropic conductive ink can be obtained, for example, by adding a solvent to the anisotropic conductive adhesive to obtain a viscosity suitable for printing. The obtained anisotropic conductive ink is, for example, screen-printed on the electrode to be bonded, the solvent is evaporated, the counter electrode is superimposed on the printed anisotropic conductive ink, and the resultant is heated and compressed. Therefore, it is used for the connection between the electrodes.

  The film thickness, coating film thickness and printed film thickness in the anisotropic conductive material are calculated from the average particle diameter of the conductive fine particles contained and the specifications of the electrodes to be connected. It is preferable to set so that the gap between the bonding substrates on which the fine particles are sandwiched and the electrodes to be connected are formed is sufficiently filled with the binder resin layer.

  The anisotropic conductive material using the conductive fine particles of the present invention not only exhibits high conductivity, but the metal layer does not peel or break even when subjected to weight compression, and the electrical conductivity between the opposing electrode substrates Connection can be secured. In addition, since it is excellent in stability over time, it is possible to maintain electrical connection between electrode substrates and improve reliability without causing deterioration in conductivity due to plating cracking or the like even during long-term use. .

  Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to these examples. In the following, “parts by weight” may be simply referred to as “parts” for convenience. In addition, “wt%” may be described as “wt%”. Various evaluations were performed as follows.

<Evaluation of plating cracks in conductive fine particles>
For the conductive fine particles, the surface of the conductive fine particles was observed with a scanning electron microscope (SEM, manufactured by HITACHI, S-3500N) at a measurement magnification of 1000 times, and cracks in the metal plating layer exceeded 0.1% of the number of observations. In this case, the evaluation was “X (good)”, and when the crack of the metal plating layer was 0.1% or less of the number of observations, the evaluation was “◯ (good)”. The number of observations was 10,000.

<Evaluation of plating defects of conductive fine particles>
For the conductive fine particles, the surface of the conductive fine particles is observed with a scanning electron microscope (SEM, manufactured by HITACHI, S-3500N) at a measurement magnification of 1000 times, and there is a portion that is not covered with a metal plating layer. In the case of “x (defect)”, the evaluation was made as “◯ (good)” when there was no portion not covered with the metal plating layer. The number of observations was 10,000.

<Evaluation of anisotropic conductive material>
1 g of conductive fine particles was mixed and dispersed in 100 g of an epoxy resin (manufactured by Mitsui Chemicals, Structbond (registered trademark), XN-5A) to prepare a conductive adhesive paste. Thereafter, 0.1 mg of this paste was sandwiched between two glass substrates with an ITO transparent electrode film formed on the inner surface, and was subjected to thermocompression bonding at 150 ° C. for 30 minutes while applying a pressure of 13.7 MPa by a press. A test piece was prepared. A PCT test was performed on the prepared test piece, and the resistance value between the electrodes before and after the PCT test and the change (resistance value increase rate) were measured.

[Example 1]: Polymer fine particles having a polymetalloxane coating on the surface of core particles (1)
(Preparation of core particle precursor)
Dissolve 2 parts of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Hightenol NF-08) as a surfactant in a four-necked flask equipped with a condenser, thermometer, and dripping port. 150 parts of an ion exchange water solution was charged. Thereto, a monomer composition composed of 80 parts of styrene, 10 parts of divinylbenzene, 10 parts of 3-methacryloxypropyltrimethoxysilane prepared in advance, and 2,2′-azobis (2 , 4-dimethylvaleronitrile) (V-65, manufactured by Wako Pure Chemical Industries, Ltd.), and the mixture was emulsified and dispersed at 5000 rpm for 5 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a suspension. . To this suspension, 250 parts of ion-exchanged water was added, the temperature was raised to 65 ° C. under a nitrogen atmosphere, and the mixture was held at 65 ° C. for 2 hours to perform radical polymerization of the monomer. After radical polymerization, the resulting emulsion is separated into solid and liquid, and the resulting cake is washed with ion-exchanged water and then with methanol, followed by precision classification, followed by vacuum drying at 40 ° C. for 2 hours in a nitrogen atmosphere. A particle precursor (1) was obtained. When the particle size of the core particle precursor (1) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle size was 4.83 μm and the coefficient of variation (CV) was 4.5%.
Subsequently, in order to hydrolyze the alkoxysilyl group remaining on the surface of the core particle precursor (1) to form —Si—OH group, 25 parts of aqueous ammonia 5% was added to 50 parts of the obtained core particle precursor (1). And 200 parts of ethanol were added and subjected to ultrasonic dispersion for 10 minutes, followed by stirring at room temperature for 12 hours. Next, the obtained suspension was subjected to solid-liquid separation, and the obtained cake was washed with ion-exchanged water and then with ethanol, and then vacuum-dried at 40 ° C. for 2 hours in a nitrogen atmosphere to obtain a core particle precursor (1 ′ )
(Preparation of polymer fine particles)
To a four-necked flask equipped with a condenser, a thermometer, and a dripping port, add 30 parts of the dried core particle precursor (1 ′), 300 parts of ethanol, 6 parts of 25% ammonia water, and 30 parts of ion-exchanged water, and 35 While stirring at ° C, a separately prepared mixed liquid of 30 parts of tetraethoxysilane and 30 parts of ethanol was added using a dropping funnel. After completion of the addition, stirring was further performed for 10 hours to complete the reaction. The resulting suspension was subjected to solid-liquid separation, and the resulting cake was washed with ion-exchanged water and then with methanol, and then vacuum-dried at 120 ° C. for 2 hours in a nitrogen atmosphere to form a polymetalloxane coating on the surface of the core particles. Polymer fine particles (1) were obtained. When the particle diameter of the polymer fine particles (1) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle diameter was 4.89 μm and the coefficient of variation (CV) was 4.5%. The thickness of the polymetalloxane coating was 0.03 μm.
The results are summarized in Tables 1 and 2.

[Example 2]: Polymer fine particles (2) having a polymetalloxane coating on the surface of core particles
(Preparation of core particle precursor)
Dissolve 2 parts of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Hightenol NF-08) as a surfactant in a four-necked flask equipped with a condenser, thermometer, and dripping port. 150 parts of an ion exchange water solution was charged. Thereto, a monomer composition composed of 60 parts of styrene, 10 parts of divinylbenzene, 30 parts of 3-methacryloxypropyltrimethoxysilane prepared in advance, and 2,2′-azobis (2 , 4-dimethylvaleronitrile) (V-65, manufactured by Wako Pure Chemical Industries, Ltd.), and the mixture was emulsified and dispersed at 5000 rpm for 5 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a suspension. . To this suspension, 250 parts of ion-exchanged water was added, the temperature was raised to 65 ° C. under a nitrogen atmosphere, and the mixture was held at 65 ° C. for 2 hours to perform radical polymerization of the monomer. After radical polymerization, the resulting emulsion is separated into solid and liquid, and the resulting cake is washed with ion-exchanged water and then with methanol, followed by precision classification, followed by vacuum drying at 40 ° C. for 2 hours in a nitrogen atmosphere. A particle precursor (2) was obtained. When the particle size of the core particle precursor (2) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle size was 3.63 μm and the coefficient of variation (CV) was 4.2%.
Subsequently, the alkoxysilyl group remaining on the surface of the core particle precursor (2) is hydrolyzed to -Si-OH groups, so that 50 parts of the obtained core particle precursor (2) is mixed with 25% aqueous ammonia 5 And 200 parts of ethanol were added and subjected to ultrasonic dispersion for 10 minutes, followed by stirring at room temperature for 12 hours. Next, the obtained suspension was subjected to solid-liquid separation, and the obtained cake was washed with ion-exchanged water and then with ethanol, and then vacuum-dried at 40 ° C. for 2 hours in a nitrogen atmosphere to obtain a core particle precursor (2 ′ )
(Preparation of polymer fine particles)
To a four-necked flask equipped with a cooling tube, a thermometer, and a dropping port, 30 parts of a dried core particle precursor (2 ′), 300 parts of ethanol, 6 parts of 25% aqueous ammonia, and 30 parts of ion-exchanged water are added, and 35 While stirring at ° C, a separately prepared mixed liquid of 30 parts of tetraethoxysilane and 30 parts of ethanol was added using a dropping funnel. After completion of the addition, stirring was further performed for 10 hours to complete the reaction. The resulting suspension was subjected to solid-liquid separation, and the resulting cake was washed with ion-exchanged water and then with methanol, and then vacuum-dried at 120 ° C. for 2 hours in a nitrogen atmosphere to form a polymetalloxane coating on the surface of the core particles. Polymer fine particles (2) were obtained. When the particle diameter of the polymer fine particles (2) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle diameter was 3.73 μm and the coefficient of variation (CV) was 4.2%. The thickness of the polymetalloxane coating was 0.05 μm.
The results are summarized in Tables 1 and 2.

[Example 3]: Polymer fine particles having a polymetalloxane coating on the surface of core particles (3)
(Preparation of core particle precursor)
In a four-necked flask equipped with a condenser, a thermometer, and a dripping port, 400 parts of ion-exchanged water, 6 parts of 25% aqueous ammonia, and 180 parts of methanol are placed, and 3-methacryloxypropyltrimethoxysilane is added to this solution while stirring. 50 parts was added from the dropping port, and hydrolysis / condensation of 3-methacryloxypropyltrimethoxysilane was performed to prepare organopolysiloxane particles. Next, 110 parts of styrene, 1 part of styrene in a solution of 0.75 part of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Hytenol NF-08) as an emulsifier with 175 parts of ion-exchanged water, , 6-hexanediol dimethacrylate 40 parts, 2,2′-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd., V-65) 4 parts dissolved solution was added, TK homomixer ( A monomer emulsion was prepared by emulsifying and dispersing at 6000 rpm for 5 minutes using a special machine manufacturer. Two hours after the start of the reaction, the monomer emulsion was added to the emulsion of organopolysiloxane particles and further stirred. Two hours after the addition of the monomer emulsion, the reaction solution was sampled and observed with a microscope. As a result, it was confirmed that the organopolysiloxane particles were enlarged by absorbing the monomer. Next, the reaction solution was heated to 65 ° C. under a nitrogen atmosphere and held at 65 ° C. for 2 hours to perform radical polymerization of the monomer. After radical polymerization, the obtained emulsion was subjected to solid-liquid separation, and the obtained cake was washed with ion-exchanged water and then methanol, and further dried under vacuum at 80 ° C. for 12 hours under a nitrogen atmosphere to obtain a core particle precursor ( 3) was obtained. When the particle size of the core particle precursor (3) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle size was 3.52 μm and the coefficient of variation (CV) was 3.8%.
(Preparation of polymer fine particles)
To a four-necked flask equipped with a condenser, a thermometer, and a dropping port, 30 parts of dried core particle precursor (3), 300 parts of ethanol, 6 parts of 25% ammonia water, and 30 parts of ion-exchanged water were added, and the temperature was 35 ° C. While stirring at, a separately prepared mixed liquid of 30 parts of tetraethoxysilane and 30 parts of ethanol was added using a dropping funnel. After completion of the addition, stirring was further performed for 10 hours to complete the reaction. The resulting suspension was subjected to solid-liquid separation, and the resulting cake was washed with ion-exchanged water and then with methanol, and then vacuum-dried at 120 ° C. for 2 hours in a nitrogen atmosphere to form a polymetalloxane coating on the surface of the core particles. Polymer fine particles (3) were obtained. When the particle size of the polymer fine particles (3) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle size was 3.60 μm and the coefficient of variation (CV) was 3.8%. The thickness of the polymetalloxane coating was 0.04 μm.
The results are summarized in Tables 1 and 2.
Moreover, the cross-sectional electron image by the field emission electron microscope (Hitachi, FE-SEM, S-4800) of the obtained polymer microparticles | fine-particles (3) is shown in FIG.1, FIG.2, FIG.3, FIG. 1 is a transmission electron image, FIG. 3 is an enlarged cross-sectional electron image of the polymetalloxane film portion of FIG. 1, FIG. 2 is a reflected electron image, and FIG. 4 is an enlarged cross-sectional electron image of the polymetalloxane film portion of FIG. is there.

[Example 4]: Polymer fine particles having a polymetalloxane coating on the surface of core particles (4)
(Preparation of core particle precursor)
In a four-necked flask equipped with a condenser, a thermometer, and a dripping port, 400 parts of ion-exchanged water, 6 parts of 25% aqueous ammonia, and 180 parts of methanol are placed, and 3-methacryloxypropyltrimethoxysilane is added to this solution while stirring. 50 parts was added from the dropping port, and hydrolysis / condensation of 3-methacryloxypropyltrimethoxysilane was performed to prepare organopolysiloxane particles. Next, 110 parts of styrene, 1 part of styrene in a solution of 0.75 part of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Hytenol NF-08) as an emulsifier with 175 parts of ion-exchanged water, , 6-hexanediol dimethacrylate 30 parts, hydroxyethyl methacrylate 10 parts, 2,2'-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd., V-65) 4 parts dissolved in a solution In addition, a monomer emulsion was prepared by emulsifying and dispersing at 6000 rpm for 5 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). Two hours after the start of the reaction, the monomer emulsion was added to the emulsion of organopolysiloxane particles and further stirred. Two hours after the addition of the monomer emulsion, the reaction solution was sampled and observed with a microscope. As a result, it was confirmed that the organopolysiloxane particles were enlarged by absorbing the monomer. Next, the reaction solution was heated to 65 ° C. under a nitrogen atmosphere and held at 65 ° C. for 2 hours to perform radical polymerization of the monomer. After radical polymerization, the obtained emulsion was subjected to solid-liquid separation, and the obtained cake was washed with ion-exchanged water and then methanol, and further dried under vacuum at 80 ° C. for 12 hours under a nitrogen atmosphere to obtain a core particle precursor ( 4) was obtained. When the particle size of the core particle precursor (4) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle size was 3.81 μm and the coefficient of variation (CV) was 3.5%.
(Preparation of polymer fine particles)
To a four-necked flask equipped with a condenser, a thermometer, and a dropping port, 30 parts of dried core particle precursor (4), 300 parts of ethanol, 6 parts of 25% ammonia water, and 30 parts of ion-exchanged water were added, and the temperature was 35 ° C. While stirring at, a separately prepared mixed liquid of 30 parts of tetraethoxysilane and 30 parts of ethanol was added using a dropping funnel. After completion of the addition, stirring was further performed for 10 hours to complete the reaction. The resulting suspension was subjected to solid-liquid separation, and the resulting cake was washed with ion-exchanged water and then with methanol, and then vacuum-dried at 120 ° C. for 2 hours in a nitrogen atmosphere to form a polymetalloxane coating on the surface of the core particles. Polymer fine particles (4) were obtained. When the particle diameter of the polymer fine particles (4) was measured by a Coulter Multinizer type III (manufactured by Beckman Coulter, Inc.), the average particle diameter was 3.93 μm, and the coefficient of variation (CV) was 3.5%. The thickness of the polymetalloxane coating was 0.06 μm.
The results are summarized in Tables 1 and 2.

[Example 5]: Polymer fine particles (5) having a polymetalloxane coating on the surface of core particles
(Preparation of core particle precursor)
In a four-necked flask equipped with a condenser, a thermometer, and a dripping port, 400 parts of ion-exchanged water, 20 parts of 25% aqueous ammonia and 180 parts of methanol are placed, and 3-methacryloxypropyltrimethoxysilane is added to this solution while stirring. 50 parts was added from the dropping port, and hydrolysis / condensation of 3-methacryloxypropyltrimethoxysilane was performed to prepare organopolysiloxane particles. Subsequently, 35 parts of divinylbenzene was dissolved in 0.75 part of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (Daiichi Kogyo Seiyaku Co., Ltd., Hytenol NF-08) as an emulsifier in 175 parts of ion-exchanged water, A solution in which 4 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd., V-65) is dissolved is added, and 6000 rpm by a TK homomixer (Special Machine Industries Co., Ltd.). A monomer emulsion was prepared by emulsifying and dispersing for 5 minutes. Two hours after the start of the reaction, the monomer emulsion was added to the emulsion of organopolysiloxane particles and further stirred. Two hours after the addition of the monomer emulsion, the reaction solution was sampled and observed with a microscope. As a result, it was confirmed that the organopolysiloxane particles were enlarged by absorbing the monomer. Next, the reaction solution was heated to 65 ° C. under a nitrogen atmosphere and held at 65 ° C. for 2 hours to perform radical polymerization of the monomer. After radical polymerization, the obtained emulsion was subjected to solid-liquid separation, and the obtained cake was washed with ion-exchanged water and then methanol, and further dried under vacuum at 80 ° C. for 12 hours under a nitrogen atmosphere to obtain a core particle precursor ( 5) was obtained. When the particle size of the core particle precursor (5) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle size was 3.15 μm and the coefficient of variation (CV) was 3.9%.
(Preparation of polymer fine particles)
To a four-necked flask equipped with a condenser, a thermometer, and a dropping port, 30 parts of dried core particle precursor (5), 300 parts of ethanol, 6 parts of 25% ammonia water, and 30 parts of ion-exchanged water were added, and the temperature was 35 ° C. While stirring at, a separately prepared mixed liquid of 30 parts of tetraethoxysilane and 30 parts of ethanol was added using a dropping funnel. After completion of the addition, stirring was further performed for 10 hours to complete the reaction. The resulting suspension was subjected to solid-liquid separation, and the resulting cake was washed with ion-exchanged water and then with methanol, and then vacuum-dried at 120 ° C. for 2 hours in a nitrogen atmosphere to form a polymetalloxane coating on the surface of the core particles. Polymer fine particles (5) were obtained. When the particle diameter of the polymer fine particles (5) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle diameter was 3.31 μm and the coefficient of variation (CV) was 3.9%. The thickness of the polymetalloxane coating was 0.08 μm.
The results are summarized in Tables 1 and 2.

[Example 6]: Polymer fine particles having a polymetalloxane coating on the surface of core particles (6)
(Preparation of core particle precursor)
In a four-necked flask equipped with a condenser, a thermometer, and a dripping port, 400 parts of ion-exchanged water, 6 parts of 25% aqueous ammonia, and 180 parts of methanol are placed, and 3-methacryloxypropyltrimethoxysilane is added to this solution while stirring. 50 parts was added from the dropping port, and hydrolysis / condensation of 3-methacryloxypropyltrimethoxysilane was performed to prepare organopolysiloxane particles. Next, 110 parts of styrene, 1 part of styrene in a solution of 0.75 part of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Hytenol NF-08) as an emulsifier with 175 parts of ion-exchanged water, , 6-hexanediol dimethacrylate 30 parts, hydroxyethyl methacrylate 10 parts, 2,2'-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd., V-65) 4 parts dissolved in a solution In addition, a monomer emulsion was prepared by emulsifying and dispersing at 6000 rpm for 5 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). Two hours after the start of the reaction, the monomer emulsion was added to the emulsion of organopolysiloxane particles and further stirred. Two hours after the addition of the monomer emulsion, the reaction solution was sampled and observed with a microscope. As a result, it was confirmed that the organopolysiloxane particles were enlarged by absorbing the monomer. Next, the reaction solution was heated to 65 ° C. under a nitrogen atmosphere and held at 65 ° C. for 2 hours to perform radical polymerization of the monomer. After radical polymerization, the obtained emulsion was subjected to solid-liquid separation, and the obtained cake was washed with ion-exchanged water and then methanol, and further dried under vacuum at 80 ° C. for 12 hours under a nitrogen atmosphere to obtain a core particle precursor ( 6) was obtained. When the particle size of the core particle precursor (6) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle size was 3.81 μm and the coefficient of variation (CV) was 3.5%.
(Preparation of polymer fine particles)
To a four-necked flask equipped with a condenser, a thermometer, and a dropping port, 10 parts of the dried core particle precursor (6), 300 parts of ethanol, 20 parts of 25% ammonia water, and 30 parts of ion-exchanged water are added, and the temperature is 35 ° C. While stirring at, a separately prepared mixed liquid of 30 parts of tetraethoxysilane and 30 parts of ethanol was added using a dropping funnel. After completion of the addition, stirring was further performed for 10 hours to complete the reaction. The resulting suspension was subjected to solid-liquid separation, and the resulting cake was washed with ion-exchanged water and then with methanol, and then vacuum-dried at 120 ° C. for 2 hours in a nitrogen atmosphere to form a polymetalloxane coating on the surface of the core particles. Polymer fine particles (6) were obtained. When the particle size of the polymer fine particles (6) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle size was 4.21 μm and the coefficient of variation (CV) was 3.6%. The thickness of the polymetalloxane coating was 0.20 μm.
The results are summarized in Tables 1 and 2.

[Comparative Example 1]: Polymer fine particles (C1) having a polymetalloxane coating on the surface of the core particles
(Preparation of core particle precursor)
Dissolve 2 parts of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Hightenol NF-08) as a surfactant in a four-necked flask equipped with a condenser, thermometer, and dripping port. 150 parts of an ion exchange water solution was charged. Thereto, a monomer composition consisting of 90 parts of styrene and 10 parts of divinylbenzene prepared in advance, and 2,2′-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical) as a polymerization initiator 2 parts of V-65) manufactured by Kogyo Co., Ltd. were charged and emulsified and dispersed at 5000 rpm for 5 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a suspension. To this suspension, 250 parts of ion-exchanged water was added, the temperature was raised to 65 ° C. under a nitrogen atmosphere, and the mixture was held at 65 ° C. for 2 hours to perform radical polymerization of the monomer. After radical polymerization, the obtained emulsion was subjected to solid-liquid separation, and the obtained cake was washed with ion-exchanged water and then with methanol, and then vacuum-dried at 40 ° C. for 2 hours in a nitrogen atmosphere to obtain a core particle precursor (C1 ) When the particle diameter of the core particle precursor (C1) was measured by Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle diameter was 3.63 μm and the coefficient of variation (CV) was 29.5%.
(Preparation of polymer fine particles)
To a four-necked flask equipped with a condenser, a thermometer, and a dropping port, 30 parts of a dried core particle precursor (C1), 300 parts of ethanol, 6 parts of 25% ammonia water, and 30 parts of ion-exchanged water are added, and the temperature is 35 ° C. While stirring at, a separately prepared mixed liquid of 30 parts of tetraethoxysilane and 30 parts of ethanol was added using a dropping funnel. After completion of the addition, stirring was further performed for 10 hours to complete the reaction. The resulting suspension was subjected to solid-liquid separation, and the resulting cake was washed with ion-exchanged water and then with methanol, and then vacuum-dried at 120 ° C. for 2 hours in a nitrogen atmosphere to form a polymetalloxane coating on the surface of the core particles. Polymer fine particles (C1) were obtained. When the particle diameter of the polymer fine particles (C1) was measured by a Coulter Multinizer III type (manufactured by Beckman Coulter, Inc.), the average particle diameter was 3.64 μm and the coefficient of variation (CV) was 29.5%. The thickness of the polymetalloxane coating was 0.005 μm.
The results are summarized in Tables 1 and 2.

[Example 7]: Conductive fine particles (1)
In a beaker, 50 parts of “Pink Summer” (manufactured by Nippon Kanisen Co., Ltd.) and 400 parts of ion-exchanged water were mixed to obtain a mixed solution. Separately, 10 parts of the polymer fine particles (1) obtained in Example 1 were added with 50 parts of ion-exchanged water and subjected to ultrasonic dispersion, and the mixture was put into the above mixture and stirred at 30 ° C. for 10 minutes. After that, the suspension was subjected to solid-liquid separation, and the obtained cake was washed with ion-exchanged water and then with methanol, and then vacuum-dried at 100 ° C. for 2 hours in a nitrogen atmosphere.
Next, 100 parts of “Red Schumer” (manufactured by Nippon Kanisen Co., Ltd.) and 350 parts of ion-exchanged water were added and mixed to obtain a mixed solution. Separately, 10 parts of the dry particles obtained above were added with 50 parts of ion-exchanged water and subjected to ultrasonic dispersion, and the mixture was put into the liquid mixture and stirred at 30 ° C. for 10 minutes, and then the suspension. The cake was washed with ion-exchanged water and then with methanol, and then vacuum-dried at 100 ° C. for 2 hours under a nitrogen atmosphere.
Through the above operation, palladium was adsorbed on the surface of the polymer fine particles (1).
The palladium active polymer fine particles obtained above were added to 500 parts of ion-exchanged water and subjected to ultrasonic dispersion for 30 minutes to sufficiently disperse the particles, thereby obtaining a suspension. While stirring this suspension at 50 ° C., from nickel sulfate hexahydrate 50 g / L, sodium hypophosphite monohydrate 20 g / L, dimethylamine borane 2.5 g / L, citric acid 50 g / L An electroless plating solution (pH = 7.5) was gradually added to the suspension for electroless nickel plating.
While sampling the particles during the plating process over time and observing them with a scanning electron microscope (SEM, manufactured by HITACHI, “S-3500N”), arbitrary 10 particle diameters are measured, and the weight before the plating process is measured. The plating thickness was calculated from the difference from the particle diameter measurement result of the coalesced fine particles (1), and the addition of the electroless plating solution was stopped when the plating thickness reached 0.1 μm. The obtained conductive fine particles were separated by filtration, washed with ion exchange water, further washed with methanol, and then vacuum dried at 60 ° C. for 12 hours to obtain conductive fine particles (1).
The obtained conductive fine particles (1) were evaluated for plating cracking and plating defects. The results are summarized in Table 3.
Moreover, anisotropic conductive material was evaluated about the obtained electroconductive fine particles (1). The results are summarized in Table 4.

[Example 8]: Conductive fine particles (2)
Conductive fine particles (2) were obtained in the same manner as in Example 6 except that the polymer fine particles (2) obtained in Example 2 were used instead of the polymer fine particles (1) obtained in Example 1. Got.
The obtained conductive fine particles (2) were evaluated for plating cracks and plating defects. The results are summarized in Table 3.
Moreover, anisotropic conductive material was evaluated about the obtained electroconductive fine particles (2). The results are summarized in Table 4.

[Example 9]: Conductive fine particles (3)
Conductive fine particles (3) were prepared in the same manner as in Example 6 except that the polymer fine particles (3) obtained in Example 3 were used instead of the polymer fine particles (1) obtained in Example 1. Got.
The obtained conductive fine particles (3) were evaluated for plating cracking and plating defects. The results are summarized in Table 3.
Moreover, anisotropic conductive material was evaluated about the obtained electroconductive fine particles (3). The results are summarized in Table 4.

[Example 10]: Conductive fine particles (4)
Conductive fine particles (4) were obtained in the same manner as in Example 6 except that the polymer fine particles (4) obtained in Example 4 were used instead of the polymer fine particles (1) obtained in Example 1. Got.
The obtained conductive fine particles (4) were evaluated for plating cracking and plating defects. The results are summarized in Table 3.
Moreover, anisotropic conductive material was evaluated about the obtained electroconductive fine particles (4). The results are summarized in Table 4.

[Example 11]: Conductive fine particles (5)
Conductive fine particles (5) were prepared in the same manner as in Example 6 except that the polymer fine particles (5) obtained in Example 5 were used instead of the polymer fine particles (1) obtained in Example 1. Got.
The obtained conductive fine particles (5) were evaluated for plating cracking and plating defects. The results are summarized in Table 3.
Moreover, anisotropic conductive material was evaluated about the obtained electroconductive fine particles (5). The results are summarized in Table 4.

[Comparative Example 2]: Conductive fine particles (C1)
Conductive fine particles (C1) were obtained in the same manner as in Example 6 except that the polymer fine particles (C1) obtained in Comparative Example 1 were used instead of the polymer fine particles (1) obtained in Example 1. Got.
The obtained conductive fine particles (C1) were evaluated for plating cracking and plating defects. The results are summarized in Table 3.
Moreover, anisotropic conductive material was evaluated about the obtained electroconductive fine particles (C1). The results are summarized in Table 4.

[Comparative Example 3]: Conductive fine particles (C2)
Conductive fine particles (C2) were prepared in the same manner as in Example 6 except that the core particle precursor (1) obtained in Example 1 was used instead of the polymer fine particles (1) obtained in Example 1. )
The obtained conductive fine particles (C2) were evaluated for plating cracking and plating defects. The results are summarized in Table 3.
Moreover, anisotropic conductive material was evaluated about the obtained electroconductive fine particles (C2). The results are summarized in Table 4.

[Comparative Example 4]: Conductive fine particles (C3)
Conductive fine particles (C3) were prepared in the same manner as in Example 6 except that the core particle precursor (3) obtained in Example 3 was used instead of the polymer fine particles (1) obtained in Example 1. )
The obtained conductive fine particles (C3) were evaluated for plating cracks and plating defects. The results are summarized in Table 3.
Moreover, anisotropic conductive material was evaluated about the obtained electroconductive fine particles (C3). The results are summarized in Table 4.

  The conductive fine particles of the present invention including the polymer fine particles of the present invention are suitable as a constituent material of an anisotropic conductive material.

It is a transmission electron image of the cross section by a field emission electron microscope of a polymer fine particle (3). It is a reflected electron image of the cross section of a polymer microparticle (3) by the field emission electron microscope. It is the electronic image which expanded the polymetalloxane film | membrane part in the electronic image of FIG. It is the electronic image which expanded the polymetalloxane film | membrane part in the electronic image of FIG.

Claims (11)

Polymer fine particles having a polymetalloxane coating containing metal atoms M on the surface of core particles P containing Si atoms,
The polymetalloxane coating is bonded to the surface of the core particle P by a structure containing -Si-OM-
Polymer fine particles.   The polymer fine particle according to claim 1, wherein the polymetalloxane coating is a polysiloxane coating containing a metal atom Si.   The polymer fine particles according to claim 1 or 2, wherein an average particle size of the polymer fine particles is 0.5 to 100 µm.   The polymer fine particle according to any one of claims 1 to 3, wherein a coverage of the polymetalloxane coating is 100%.   5. The polymer fine particle according to claim 1, wherein the polymetalloxane coating has a thickness of 1 to 500 nm, and the thickness is substantially uniform on the surface of the core particle P. 6. A method for producing polymer fine particles having a polymetalloxane coating containing a metal atom M on the surface of a core particle P containing Si atoms,
A hydrolyzable organometallic compound or a condensate obtained by hydrolyzing at least a part thereof is added to a solvent in which a core particle precursor P ′ having a —Si—OH group on the surface is dispersed, / Or conduct a condensation reaction,
A method for producing polymer fine particles.   The manufacturing method according to claim 6, wherein the polymetalloxane coating is a polysiloxane coating containing a metal atom Si.   The hydrolyzable organometallic compound is a metal alkoxide represented by the general formula MXn (wherein M is a metal atom having a valence of n and X is an alkoxy group). The manufacturing method as described. The hydrolyzable organometallic compound is an organosilicon compound represented by the general formula R ¹ pSiY ¹ q (where R ¹ is an optionally substituted hydrocarbon group, and Y ¹ is —OH group, -OR ² group is either a halogen atom, a hydrogen atom, R ² is an alkyl group, an acyl group, an aryl group, an aralkyl group, p and q are the integers) satisfying p + q = 4 The manufacturing method according to claim 6 or 7.   Conductive fine particles comprising the polymer fine particles according to any one of claims 1 to 5 and a metal layer. The conductive fine particles according to claim 10, wherein the metal layer is a layer formed by an electroless plating method.