JP2006117850A - Polymer fine particles and production process thereof, conductive fine particles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide polymer fine particles which exhibit a monodispersion with a narrow distribution of particle diameters and further possess softness and excellent elasticity. <P>SOLUTION: The polymer particles are produced by polymerizing a polysiloxane having vinyl groups and a polymerizable component having at most 10 mass% solubility to water of 25°C and having, as a necessary element, a bifunctional oligomer of a weight average molecular weight (Mw) of at least 300 with two (meth)acryloyl groups in a molecule. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to polymer fine particles in which a vinyl polymer is contained in polysiloxane particles, a method for producing the polymer fine particles, and conductive fine particles using the polymer fine particles.

  Conventionally, for spacers for cell gaps (or panel gaps) such as display displays such as liquid crystal display devices and touch panels, conductive gap agents such as conductive adhesives and anisotropic conductive adhesives for mounting micro devices, etc. In general, polymer particles having a substantially uniform particle shape are widely used. In these applications, the gap between two opposing substrates (or panels) is uniform, and the polymer particles do not physically damage the contact surface with these substrates. From this point of view, the polymer fine particles used in this technical field are monodispersed and have a narrow particle size distribution, and are flexible, resistant to crushing under compression load, and further released from compression. In some cases, it is required to have a restoring force that returns to the original shape (flexible and excellent in elasticity).

For example, as polymer fine particles having elasticity, Patent Document 1 proposes crosslinked polymer fine particles obtained from a butadiene oligomer having a (meth) acryl group at both ends and a polyfunctional acrylate ester. It is described that the coalesced fine particles have a particle diameter of 1 to 1000 μm and a compressive elastic modulus at 10% compressive deformation is 350 kgf / mm ² (3430 N / mm ² ) or less. Further, Patent Document 2 discloses that elastic fine particles obtained by copolymerizing a (poly) alkyl glycol group-containing di (meth) acrylate and a crosslinkable monomer have a compression modulus of 10 at 10% compression deformation. It is disclosed to have ˜250 kgf / mm ² (98 to 2450 N / mm ² ).

  In addition to the polymer fine particles composed only of the organic component as described above, organic-inorganic composite fine particles containing an inorganic component have also been studied. For example, polysiloxane composite particles obtained by graft polymerization of a water-insoluble vinyl monomer. (Patent Document 3), organic-inorganic composite particles including an organic polymer skeleton and a polysiloxane skeleton (Patent Document 4, Patent Document 5), conductive fine particles composed of crosslinked vinyl polymer fine particles three-dimensionally crosslinked by siloxane crosslinking ( Patent Document 6) has been proposed.

However, the above-mentioned polymer fine particles have elasticity, but have a wide particle size distribution, the particle size distribution is monodisperse, but it is difficult to obtain the desired elasticity, and it has the desired elasticity but a compressive load. There is a problem that the degree of deformation below is large. With these conventional techniques, it is difficult to obtain polymer fine particles satisfying all of the above required characteristics, and there is room for further study.
JP-A-8-225625 JP 2000-319309 A Japanese Patent Laid-Open No. 4-15209 JP-A-8-81561 JP 2003-183337 A Japanese Patent Laid-Open No. 11-199671

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide polymer fine particles which are monodispersed, have a narrow particle size distribution, are flexible and have excellent elasticity, and a method for producing the same.

  The polymer fine particles of the present invention capable of solving the above-mentioned problems are a polysiloxane having a vinyl group, a solubility in water at 25 ° C. of 10% by mass or less, and two (meth) in one molecule. It has a gist in that it is obtained by polymerizing a polymerizable component having a bifunctional oligomer having an acryloyl group and having a weight average molecular weight (Mw) of 300 or more as an essential component.

  The reason why the polymer fine particles of the present invention having the above-described structure have excellent compression deformation recovery properties (elasticity) as well as flexibility and elasticity is considered as follows. In other words, radical polymerization of the polysiloxane and the polymerizable component causes them to be polymerized, and a polymerization reaction proceeds between the polymerizable component and the vinyl group contained in the polysiloxane skeleton. The polymer derived from the polymerizable component is firmly bonded. Thereby, the polymer fine particles of the present invention have an appropriate hardness. At the same time, the molecular chain between the bonds generated by the above reaction contributes to the flexibility and compression deformation recovery of the polymer fine particles of the present invention. That is, the polymerizable component used in the present invention has a weight average molecular weight (Mw) having a solubility in water of 25 ° C. of 10% by mass or less and having two (meth) acryloyl groups in one molecule. 300 or more oligomers (hereinafter sometimes referred to as bifunctional oligomers) are essential. Since the molecular chain of the bifunctional oligomer having such characteristics has a certain length, by using such a bifunctional oligomer as an essential component, the polymer derived from the polymerizable component produced by the above reaction can be used. The crosslink point distance can be increased. In addition, the molecular chain that connects the two vinyl groups bonded to the polysiloxane skeleton becomes longer, and an appropriate distance between cross-linking points can be secured. As a result, flexibility and compressive deformation recovery are imparted to the polymer fine particles of the present invention.

The polymer fine particles preferably have an average particle diameter of 1 to 1000 μm and a Cv value of 20% or less. Further, the compression elastic modulus (10% K value) when the diameter of the polymer fine particles is displaced by 10% is 2450 N / mm ² or more, the compression deformation recovery rate is 15% or more, and further, the weight It is preferable that the displacement amount of the coalesced fine particles at 1 g load is 30% or more with respect to the diameter of the polymer fine particles, and the compression deformation recovery rate is 15% or more.

With the method for producing polymer fine particles of the present invention,
(1) Weight average molecular weight (Mw) of 300 or more having a solubility in water at 25 ° C. of 10% by mass or less in polysiloxane particles having a vinyl group and having two (meth) acryloyl groups in one molecule. An absorption step in which a polymerizable component essentially comprising the bifunctional oligomer is absorbed and added to the polysiloxane particles in an emulsified and dispersed state in water, or
(2) Weight average molecular weight (Mw) having solubility in water at 25 ° C. of 10% by mass or less in polysiloxane particles having no vinyl group and having two (meth) acryloyl groups in one molecule An absorption step of absorbing in addition to the polysiloxane particles in a state in which a polymerizable component essentially comprising a bifunctional oligomer of 300 or more and a polymerizable monomer having a vinyl group and a hydrolyzable silyl group is emulsified and dispersed in water; ,
The main point is that it includes a polymerization step of polymerizing the polymerizable component absorbed in the polysiloxane particles in the absorption step.

  By adopting such a production method, bonds are formed not only between the polymerizable components but also between the polysiloxane particles and the polymerizable components contained in the polysiloxane particles (especially bifunctional oligomers). Therefore, in addition to the polymer fine particles having an appropriate hardness and flexibility and an excellent compression deformation rate, the polymer fine particles can be monodispersed and have a narrow particle size distribution.

  The present invention also includes conductive fine particles characterized in that a conductor layer is formed on the surface of the polymer fine particles.

  The polymer fine particles of the present invention are monodispersed, have a narrow particle size distribution, and have excellent compressive deformation recovery (elasticity) as well as flexibility and elasticity. It can be preferably used as a spacer (gap retaining material) between the substrates such as, and as base particles of conductive fine particles used for anisotropic conductive materials. Conductive fine particles based on polymer fine particles having the above characteristics are also useful as electrical connection materials for electronics. Moreover, according to the production method of the present invention, polymer fine particles having a desired particle diameter and a narrow particle size distribution can be easily prepared.

  The polymer fine particles of the present invention have a weight average molecular weight (polysiloxane having a vinyl group and a solubility in water at 25 ° C. of 10% by mass or less and having two (meth) acryloyl groups in one molecule ( Mw) It is obtained by polymerizing a polymerizable component having a bifunctional oligomer of 300 or more as an essential component. That is, the polymer fine particles of the present invention are polymer fine particles comprising a polysiloxane skeleton as an inorganic part and an organic polymer skeleton as an organic part, and at least one carbon atom in the organic polymer skeleton is present. In the molecule, it has an organosilicon atom directly chemically bonded to a silicon atom in the polysiloxane skeleton (chemical bond type). In other words, the polymer fine particles of the present invention have a form in which a polysiloxane skeleton and an organic polymer skeleton form a three-dimensional network structure.

  The polysiloxane skeleton is defined as a compound in which a siloxane unit represented by the following formula (1) is continuously chemically bonded to form a network having a network structure.

The amount of Si—O bonds constituting the polysiloxane skeleton is determined by measuring the mass of SiO ₂ because SiO ₂ is produced by firing the polymer fine particles in an oxidizing atmosphere such as air at a temperature of 1000 ° C. or higher. Is required.

The amount of Si—O bonds constituting the polysiloxane skeleton (in terms of the amount of SiO ₂ ) is preferably 0.1 to 40% by mass, more preferably 0.5 to 30% by mass, based on the mass of the polymer fine particles. More preferably, it is 1.0 to 25% by mass. When the amount of Si—O bonds in the polysiloxane skeleton is less than the above range, the flexibility and elasticity of the particles are reduced, and the polymer fine particles are destroyed when an external stress is applied to the polymer fine particles. If the above range is exceeded, the polymer fine particles may be too hard to obtain sufficient flexibility. The amount of SiO ₂ in the polysiloxane skeleton can be controlled within the above range by adjusting the combination of raw materials forming the polysiloxane skeleton and the composition ratio of the polysiloxane and the polymerizable component to be polymerized.

  First, the polysiloxane having the vinyl group will be described. This polysiloxane having a vinyl group has a polysiloxane skeleton structure obtained by hydrolyzing and condensing a compound raw material containing a silicon compound having a vinyl group as an essential component. And obtained by hydrolysis and condensation in a solvent containing water. The timing of introduction of the vinyl group is not particularly limited. For example, an embodiment using a vinyl group as the hydrolyzable silicon compound, a hydrolyzable silicon compound having no vinyl group is hydrolyzed and condensed. After preparing seed particles (polysiloxane having no vinyl group), the seed particles (polysiloxane having no vinyl group) and a hydrolyzable silicon compound having a vinyl group are hydrolyzed and condensed. Any of the embodiments in which a vinyl group is introduced into the polysiloxane can be employed. In the latter case, the polymer fine particles of the present invention are synthesized by simultaneously performing radical polymerization reaction with the polymerizable component during the hydrolysis and condensation of the seed particles and the hydrolyzable silicon compound having a vinyl group. (A method for producing [B] and [C] described later).

Although the said hydrolysable silicon compound is not specifically limited, For example, the silane compound represented by following General formula (2) and its derivative (s) can be used.
R ^a _m SiX _4-m (2)
(Wherein R ^a may have ^a substituent and represents at least one group selected from the group consisting of an alkyl group, an aryl group, an aralkyl group and an unsaturated aliphatic group; X represents a hydroxyl group, an alkoxy group; And at least one group selected from the group consisting of a group and an acyloxy group, and m represents an integer of 0 to 3.)

  Examples of the silane compound represented by the general formula (2) include the following. For m = 0, tetrafunctional silanes such as tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, and tetrabutoxysilane; for m = 1, methyltrimethoxysilane, methyltriethoxysilane, ethyl Trimethoxysilane, ethyltriethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, phenyltrimethoxysilane, benzyltrimethoxysilane, naphthyltrimethoxysilane, methyltriacetoxysilane, β- (3,4-epoxycyclohexyl) ethyl Trimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane Trifunctional silanes; m = 2, bifunctional silanes such as dimethylsilane, dimethyldiethoxysilane, diacetoxydimethylsilane, dimethoxydiphenylsilanediol, etc .; m = 3, trimethyl, trimethylethoxy And monofunctional silanes such as silane and trimethylsilanol.

  The hydrolyzable silicon compound may be used alone or in combination of two or more. In addition, in the said General formula (2), when only the silane compound and its derivative which are m = 3 are used as a raw material, composite particle | grains are not obtained.

As described above, in the present invention, a hydrolyzable silicon compound having a vinyl group is used as an essential component. Examples of the hydrolyzable silicon compound having a vinyl group include those having a polymerizable reactive group represented by the following general formulas (3), (4) and (5).
^{_{CH 2 = C (-R b)}} -COOR c - (3)
(Here, R ^b represents a hydrogen atom or a methyl group, and R ^c represents a divalent organic group having 1 to 20 carbon atoms which may have a substituent.)
^{_{CH 2 = C (-R d)}} - (4)
(Here, R ^d represents a hydrogen atom or a methyl group.)
^{_{CH 2 = C (-R e)}} -R f - (5)
(Here, R ^e represents a hydrogen atom or a methyl group, and R ^f represents a C 1-20 divalent organic group which may have a substituent.)

  Examples of the polymerizable reactive group represented by the general formula (3) include an acryloxy group and a methacryloxy group. Examples of the silicon compound of the general formula (2) having the organic group include γ- Methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxypropyltriacetoxysilane, γ-methacryloxyethoxypropyltri Methoxysilane (or γ-trimethoxysilylpropyl-β-methacryloxyethyl ether), 11-methacryloxyundecamethylenetrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyl Chill diethoxy silane, etc. γ- acryloxypropylmethyldimethoxysilane can be exemplified.

  Examples of the polymerizable reactive group represented by the general formula (4) include a vinyl group and an isopropenyl group. Examples of the silicon compound of the general formula (2) having the organic group include a vinyl trimethyl group. Methoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, 4-vinyltetramethylenetrimethoxysilane, 8-vinyloctamethylenetrimethoxysilane, 3-trimethoxysilylpropylvinylether, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, Examples thereof include vinylmethyldiacetoxysilane. These may be used alone or in combination of two or more.

  Examples of the polymerizable reactive group represented by the general formula (5) include a 1-alkenyl group, a vinylphenyl group, an isoalkenyl group, and an isopropenylphenyl group, and the general formula having the organic group. Examples of the silicon compound (2) include 1-hexenyltrimethoxysilane, 1-hexenyltriethoxysilane, 1-octenyltrimethoxysilane, 1-decenyltrimethoxysilane, γ-trimethoxysilylpropyl vinyl ether, ω -Trimethoxysilylundecanoic acid vinyl ester, p-trimethoxysilylstyrene, p-triethoxysilylstyrene, p-trimethoxysilyl-α-methylstyrene, p-triethoxysilyl-α-methylstyrene, N-β- ( N-vinylbenzylaminoethyl-γ-aminopropi ) Trimethoxysilane hydrochloride, 1-hexenyl methyldimethoxysilane, and the like 1-hexenyl diethoxy silane. These may be used alone or in combination of two or more.

  The polysiloxane according to the present invention is obtained by hydrolyzing and condensing the hydrolyzable silicon compound group in a solvent containing water. About hydrolysis and condensation, arbitrary methods, such as a lump, a division | segmentation, and a continuation, can be taken. In addition, 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.

  The organic solvent is not particularly limited. For example, methanol, ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, pentanol, ethylene glycol, propylene glycol, 1,4-butanediol Alcohols such as acetone, ketones such as methyl ethyl ketone, esters such as ethyl acetate, (cyclo) paraffins such as isooctane and cyclohexane, ethers such as dioxane and diethyl ether, and aromatic hydrocarbons such as benzene and toluene Etc. are preferred. These may be used alone or in combination of two or more.

  The hydrolysis and condensation reaction is carried out by adding the above-mentioned silicon compound group and organic solvent to a solvent containing water and stirring in a temperature range of 0 to 100 ° C., preferably 0 to 70 ° C., for 30 minutes to 100 hours. Just do it. In this case, the water concentration is 10 to 99.99% by mass, the catalyst concentration is 0.01 to 10% by mass, the organic solvent concentration is 0 to 90% by mass, and the concentration of the silicon compound group is 0.1 to 30% by mass. % Is preferable. Further, the addition time of the silicon compound group is preferably 0.001 to 500 hours, and the reaction temperature is preferably 0 to 100 ° C. In addition, when using the particle | grains obtained by carrying out a hydrolysis / condensation reaction beforehand as a seed particle (in the case of the manufacturing method of [B] and [C] mentioned later), the density | concentration of a seed particle is 0.1-30 mass%. It is preferable to set to.

  In addition, particles obtained by hydrolysis and condensation reaction are charged in advance into a synthesis system as seed particles, and the above-described silicon compound group is added thereto to grow the seed particles, thereby obtaining polysiloxane particles. You can also. In this manner, the silicon compound group is hydrolyzed and condensed under a suitable condition in a solvent containing water, whereby particles are precipitated and a slurry is generated. The precipitated particles are obtained by using the above-described silicon compound having a vinyl group as an essential component, and thus become polysiloxane particles having a vinyl group. Here, the appropriate conditions are not particularly limited. For example, the slurry containing seed particles (preferably having a concentration of 0.1 to 20% by mass) obtained in advance by hydrolysis and condensation reaction may be used for the above-mentioned hydrolysis. Conditions under which the concentration of the decomposable silicon compound is 20% by mass or less, the water concentration is 50% by mass or more, and the catalyst concentration is 10% by mass or less are preferable.

  The shape of the polysiloxane particles may be any 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, and a confetti shape, and is not particularly limited.

  The average particle diameter of the polysiloxane particles is not particularly limited, but is preferably 0.1 to 700 μm, more preferably 0.5 to 70 μm, and most preferably 1 to 35 μm. When the average particle diameter of the polysiloxane particles is within the above range, it is possible to exert an advantageous effect that absorption of a polymerizable component described later proceeds efficiently. On the other hand, if the average particle size of the polysiloxane particles is too small, the polymerization components described later may not be sufficiently absorbed. If it is too large, the mass of the particles will increase and the polymer in the reactor will become large. Precipitation of fine particles occurs and the particles tend to aggregate.

  The sharpness of the particle size distribution of the polysiloxane particles is not particularly limited, but 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, it is possible to exhibit an advantageous effect that the particles obtained by polymerization are monodispersed after absorption of the polymerizable component described later. When the coefficient of variation exceeds the above range, the variation in the particle diameter of the polymer fine particles obtained becomes large, and when used as a gap holding material for uniform gaps between various substrates, the gap distance uniformity is It becomes insufficient. The coefficient of variation (Cv value) is determined by the measurement method described in the examples described later.

  The polysiloxane particles obtained as described above are particles that can easily absorb and retain a polymerizable component described later in the polysiloxane skeleton constituting the particles. This can be said to be because the polysiloxane particles have a degree of condensation suitable for absorbing a polymerizable component described later.

  Next, the polymerizable component to be polymerized with the polysiloxane particles will be described. The polymerizable component is essentially a bifunctional oligomer having a solubility in water of 25 ° C. of 10% by mass or less and having two (meth) acryloyl groups in one molecule and having a weight average molecular weight of 300 or more. Is included.

  As described above, the polymerizable component imparts flexibility and compressive deformation recovery to the polymer fine particles of the present invention. In addition, when the solubility with respect to the 25 degreeC water of the said bifunctional oligomer is too low, when making it absorb in the said polysiloxane particle, there exists a tendency for the said bifunctional oligomer to become difficult to be absorbed. On the other hand, when the solubility in water at 25 ° C. is too high, the absorbed bifunctional oligomer is redissolved in the medium and polymerized in the medium, and by-product fine particles are generated in addition to the intended polymer fine particles. The reaction system may become colloidally unstable and agglomerates may be generated. Accordingly, the solubility of the bifunctional oligomer in water at 25 ° C. is preferably 0.001% by mass or more, more preferably 0.003% by mass or more, and preferably 10% by mass or less. Is 5% by mass or less. In addition, also as the whole polymeric component, it is preferable that the solubility with respect to 25 degreeC water is 0.001 mass% or more and 5 mass% or less.

Similarly, when the weight average molecular weight of the bifunctional oligomer is too large, it is difficult to be absorbed in the polysiloxane particles, so the upper limit of the weight average molecular weight is preferably 5000 or less, more preferably 3000 or less, and further Preferably it is 2000 or less. On the other hand, if the weight average molecular weight is too small, the resulting polymer fine particles may have poor mechanical properties. Therefore, in the present invention, the lower limit of the weight average molecular weight of the bifunctional oligomer is set to 300.

  The bifunctional oligomer preferably has a viscosity measured at 25 ° C. of 0 to 3000 mPa · s. More preferably, it is 1-2000 mPa * s, More preferably, it is 1-1500 mPa * s. If the viscosity is too large, emulsification becomes difficult when the monomer is absorbed, so that the particle size of the monomer emulsion becomes large, and the monomer cannot be sufficiently absorbed by the seed particles. The viscosity of the bifunctional oligomer may be measured according to JIS K-6901.

  The bifunctional oligomer is not particularly limited as long as it satisfies the above characteristics. For example, polyethylene glycol di (meth) acrylate; polypropylene glycol di (meth) acrylate such as propylene glycol di (meth) acrylate; tripropylene glycol Di (meth) acrylate; polytetramethylene glycol di (meth) acrylate; neopentyl glycol di (meth) acrylate; 1,3-butylene glycol di (meth) acrylate; 2,2-bis [4- (methacryloxyethoxy) 2,2-bis [4- (methacryloxypolyethoxy) phenyl] propanedi (meth) acrylate such as phenyl] propanedi (meth) acrylate; 2,2-hydrogenated bis [4- (acryloxypolyethoxy) phenyl] propanedi EO modified di (meth) acrylate of bisphenol A, such as meth) acrylate, isocyanuric acid EO-modified di (meth) acrylate. Among these, compounds represented by the following structural formula are preferred.

  Examples of the bifunctional oligomer having the above structure include NK ester series “9PG”, “APG-200”, “APG-400”, “APG-700”, “BPE-100” manufactured by Shin-Nakamura Chemical Co., Ltd. , “BPE-200”, “BPE-500”, etc. “KAYARAD HX-220”, “KAYARAD HX-620” manufactured by Nippon Kayaku Co., Ltd., “Light Acrylate PTMGA-250” manufactured by Kyoeisha Chemical Co., Ltd. Or the like. In addition to these, “KAYARAD MANDA” and “KAYARAD R-167” manufactured by Nippon Kayaku Co., Ltd. are also preferably used.

  The component that can be used in combination with the bifunctional oligomer as the polymerizable component is not particularly limited, but it is preferable to use a radical polymerizable vinyl monomer in consideration of compatibility with the polysiloxane particles. The radical polymerizable vinyl monomer is preferably a compound containing at least one ethylenically unsaturated group in the molecule, and may be appropriately selected so that the polymer fine particles of the present invention can exhibit desired physical properties. . Specifically, monomers having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate; methoxypolyethylene glycol (meth) acrylate, etc. Monomers having a polyethylene glycol component: butyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, isoamyl acrylate, lauryl (meth) acrylate, benzyl methacrylate, tetrahydromethacrylate Alkyl (meth) acrylates such as furfuryl; fluorine atoms such as trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, pentanefluoropropyl (meth) acrylate, and octafluoroamyl (meth) acrylate Organic (meth) acrylates; aromatic vinyl compounds such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-ethylstyrene; glycidyl ( Examples include meth) acrylate, (meth) acrylic acid, (meth) acrylamide, (meth) acrylonitrile and the like.

  The above radical polymerizable vinyl monomers may be used alone or in combination of two or more. When the polymerizable component is absorbed by the polysiloxane particles, a hydrophobic radical-polymerizable vinyl monomer is used in order to form a stable emulsion in advance by emulsifying and dispersing the polymerizable component to form an emulsion. It is preferable.

  Moreover, a crosslinkable monomer may be used, and the adjustment of the mechanical properties of the resulting polymer fine particles becomes easy. The crosslinkable monomer is not particularly limited. For example, divinylbenzene, 1,6-hexanediol di (meth) acrylate, neopentylglycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol Examples include methane tri (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, dipentaerythritol hexaacrylate, diallyl phthalate and its isomer, triallyl isocyanurate and its derivative, and the like. These may be used alone or in combination of two or more.

  The polymerizable component may contain the hydrolyzable silicon compound described above. As the hydrolyzable silicon compound, those having a vinyl group and those not having a vinyl group can be used, but when polysiloxane particles having no vinyl group are used as seed particles (described later in (2 In the production method)), it is necessary to add a hydrolyzable silicon compound having a vinyl group to the polymerizable component.

  The bifunctional oligomer is preferably 20% by mass or more, more preferably 30% by mass in 100% by mass of the polymerizable component (that is, the total amount of the bifunctional oligomer and the radical polymerizable vinyl monomer). % Or more, more preferably 40% by mass or more. If the amount of the bifunctional oligomer is too small, the compression deformation recovery rate of the obtained polymer fine particles may be inferior. All the polymerizable components may be the above bifunctional oligomers.

  Further, the component derived from the bifunctional oligomer in the obtained polymer fine particles is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, and 99% by mass or less. Preferably, it is 95 mass% or less, more preferably 90 mass% or less.

  The method for producing the polysiloxane particles includes: [A] a method for producing seed particles (polysiloxane having a vinyl group) by hydrolyzing and condensing the hydrolyzable silicon compound having a vinyl group, and [B] a vinyl group. Hydrolyzable silicon compound that does not contain hydrolysable silicon compounds to produce seed particles (1) (polysiloxane that does not have vinyl groups), and then hydrolyzable that has seed particles (1) and vinyl groups A method of producing seed particles (2) (polysiloxane having a vinyl group) by hydrolyzing and condensing with a silicon compound, and [C] hydrolyzing and condensing a hydrolyzable silicon compound having no vinyl group. A seed particle (1) (polysiloxane having no vinyl group) is prepared, and the seed particle (1) absorbs a hydrolyzable silicon compound having a vinyl group and a polymerizable component described later ( In this case, the polysiloxane in the seed particle (1) and the hydrolyzable silicon compound having a vinyl group are hydrolyzed and condensed to give the seed particle (2) (polysiloxane having a vinyl group). Any of the methods for producing can be employed.

  In addition, when employ | adopting the manufacturing method of said [C], since superposition | polymerization with the hydrolyzable silicon compound which has a vinyl group, and a polymeric component also advances simultaneously with the production | generation of a seed particle (2), it is obtained as a result. This is the polymer fine particle of the present invention.

  The polymer fine particles of the present invention are excellent in balance of mechanical properties (compression elastic modulus, compression deformation recovery rate, displacement amount at 1 g load, etc.). For the details of the mechanical characteristics, the definitions and measurement / evaluation methods described in Examples described later are adopted. The effects on the mechanical properties of the polymer fine particles of the present invention include the constitution ratio of the inorganic component derived from the polysiloxane particles and the polymer derived from the polymerizable component, and the bifunctional oligomer constituting the polymer derived from the polymerizable component. It can be controlled by adjusting the ratio with other radical polymerizable vinyl monomers. In the polymer fine particles referred to in the present invention, it is preferable that at least one vinyl group of the polysiloxane particle is bonded to another reactive group and / or polymer. Examples of the bonded form include a form bonded to a polymer derived from a polymerizable component, a form bonded to or polymerized by reacting with at least one other reactive group in the polysiloxane particle, and the form However, the present invention is not particularly limited to these, and the like. In particular, in the case where the vinyl group of the polysiloxane particle is bonded to the polymer derived from the polymerizable component, the polymer derived from the polymerizable component is more firmly fixed in the structure of the polysiloxane particle. It is possible to have stable mechanical properties for a long time. Similarly, the shape of the polymer fine particles can be made closer to a true sphere by the above bonding.

The polymer fine particles of the present invention having the above structure have a compression elastic modulus (10% K value) of 2450 N / mm ² or more when the diameter of the polymer fine particles is displaced by 10%, and a compression deformation recovery rate of 15%. The above is preferable. Here, the compression modulus (10% K value) indicates the flexibility of the polymer particles, and the compression deformation recovery rate indicates the elasticity of the polymer fine particles. The upper limit is not particularly limited, but is preferably 20000N / mm ² or less, more preferably 15000 N / mm ^2, more preferably not more than 10000 N / mm ^2. If the compression modulus is too small, the polymer fine particles are too flexible, and when used as a gap holding material between various substrates, it may be difficult to keep the gap distance uniform, while it is too large. In such a case, the polymer fine particles are too hard and there is a risk of damaging the substrate surface when used as the gap retaining material.

  The compression deformation recovery rate is an index of the elasticity of the polymer fine particles. When a constant load is applied to the polymer fine particles and the load is removed, the particle size of the polymer fine particles before and after the load is applied. It is obtained from the amount of displacement. The compression deformation recovery rate of the polymer fine particles of the present invention is preferably 15% or more, more preferably 20% or more, and further preferably 25% or more. Needless to say, the upper limit of the compression deformation recovery rate is not particularly limited, and of course 100%, that is, it is preferable that the particle diameter of the polymer fine particles before and after loading is not changed.

  The polymer fine particles of the present invention preferably have a displacement amount of 30% or more with respect to the diameter of the polymer fine particles when loaded with 1 g. The displacement amount at the time of 1 g load indicates the ease of deformation of the polymer fine particles of the present invention, particularly the ease of deformation at the time of low load load. The displacement at the time of 1 g load is preferably 30% or more, more preferably 35% or more, still more preferably 40% or more, and preferably 85% or less, more preferably 80% or less. More preferably, it is 75% or less. Similar to the compression deformation recovery rate, when the displacement amount at the time of 1 g load is not included in the above range, it tends to be difficult to keep the gap distance uniform when used as a gap holding material between various substrates. is there.

  The average particle diameter of the polymer fine particles of the present invention means the average particle diameter in a state where the polymer derived from the polymerizable component is contained inside the polysiloxane particles and complexed as described above. Although the said average particle diameter is not specifically limited, It is preferable that it is 1-1000 micrometers, More preferably, it is 1-100 micrometers, More preferably, it is 1-50 micrometers. When the average particle diameter is within the above range, the ratio of the inorganic component derived from the polysiloxane particles and the organic component derived from the polymerizable component can be widely changed. For example, even if the average particle diameter is the same, Further, it is possible to exert an advantageous effect that various mechanical properties such as particle hardness and breaking strength can be changed. When the average particle size is too small, the content of the polymer derived from the polymerizable component is reduced, and when it is too large, the amount of the polymerizable component absorbed by the polysiloxane particles is extremely increased. Polymerization stability may deteriorate and aggregation may occur between polymer fine particles.

  The polymer fine particles of the present invention can have a desired particle diameter by adjusting the content of the polymer derived from the polymerizable component contained in the structure of the polysiloxane particles. The sharpness of the particle size distribution of the polymer fine particles of the present invention is not particularly limited. For example, the particle diameter variation coefficient (Cv value) is preferably 20% or less, more preferably 10% or less, and still more preferably 5 % Or less. When the coefficient of variation (Cv value) is within the above range, when used as a gap holding material for making gaps between various substrates uniform, an advantageous effect of keeping the gap distance uniform can be exhibited. it can. On the other hand, when the variation coefficient (Cv value) exceeds the above range, the uniformity of the gap distance may not be sufficiently maintained when used as a gap holding material.

  As a method for confirming that the polymer fine particles of the present invention are particles in which a polymer derived from the polymerizable component is contained inside polysiloxane particles composed of polysiloxane particles having a vinyl group, for example, The obtained polymer fine particles are heated and extracted with an organic solvent such as toluene, and the particle size and weight of the polymer fine particles do not change before and after the heat extraction, so that the polymer derived from the polymerizable component is inside the polysiloxane particles (in the structure). A method of confirming the presence by incorporation, or by cutting the obtained polymer fine particles and observing the cross section, the polymer derived from the polymerizable component is contained inside the polysiloxane particles (in the structure) The method of confirming that it becomes is mentioned.

  The shape of the polymer fine particle of the present invention is not particularly limited, and examples thereof include a spherical shape, a needle shape, a plate shape, a scale shape, a pulverized shape, an uneven shape, an eyebrows shape, and a confetti shape.

  The polymer fine particles of the present invention may be colored with dyes and pigments. As the color, it is preferable that light does not easily transmit or does not transmit light. For example, black, dark blue, amber, purple, blue, dark green, green, brown, red, and the like are preferable. This is because, if polymer fine particles colored in these colors are used as, for example, a spacer for a liquid crystal display device, the particles themselves can be prevented from passing through and the image quality contrast can be improved. Particularly preferred are black, dark blue, and amber.

  The dye and / or pigment may be simply contained in the polymer fine particle, or may have a structure in which the dye and / or pigment and the matrix constituting the polymer fine particle are combined by chemical bonding. However, it is not particularly limited to these.

  The dye is appropriately selected and used according to the color to be colored, and examples thereof include disperse dyes, acid dyes, basic dyes, reactive dyes, sulfur dyes and the like classified according to the dyeing method. Specific examples of these dyes are “Chemical Handbook Applied Chemistry, Japan Chemical Society” (published by Maruzen Co., Ltd., 1986), pages 1399-1427, “Nippon Kayaku Dye Handbook” (1973, published by Nippon Kayaku Co., Ltd. )It is described in. As a method for dyeing polymer fine particles, a conventionally known method can be employed. For example, it can be carried out by the methods described in the above-mentioned “Chemical Handbook Applied Chemistry, Japanese Chemical Society” or “Nippon Kayaku Dye Handbook”.

  Examples of the pigment include, but are not limited to, inorganic pigments such as carbon black, iron black, chromium vermillion, molybdenum red, red pepper, chrome yellow, chrome green, cobalt green, ultramarine blue, and bitumen; phthalocyanine series, azo series, Examples include organic pigments such as quinacridone. When the average particle diameter of the pigment exceeds 0.1 μm, it may be difficult to introduce into the polymer fine particles. In such a case, it is preferable to use a dye instead of the pigment. When the polymer fine particles are colored, when used as a spacer for a liquid crystal display device, light leakage of a backlight can be prevented and image quality improvement of the liquid crystal display device can be achieved.

  The use of the polymer fine particles of the present invention is not particularly limited. For example, in-plane spacers for liquid crystal display elements, seal spacers for liquid crystal display elements, spacers for EL display elements, spacers for touch panels, and between various substrates such as ceramics and plastics And a gap distance holding spacer such as a gap holding material that can hold the gaps uniformly.

  When the polymer fine particle of the present invention is used as the gap maintaining material, the polymer fine particle of the present invention may be used as it is, or the whole polymer fine particle, its surface is subjected to some treatment, What gave the specific physical property may be sufficient. As the above treatment, the polymer fine particle of the present invention is used as a particle main body, and a resin or the like is attached to the surface or grafted, and the polymer fine particle is coated to form an adhesive layer. Examples include those in which the resin particles themselves are colored by adding a dye or the like to the reaction system during the synthesis of the polymer fine particles, or those in which these adhesive and coloring functions are combined.

The method for producing polymer fine particles according to the present invention (hereinafter sometimes referred to as the production method of the present invention) is as follows: (1) The solubility in water at 25 ° C. is 10% by mass in polysiloxane particles having a vinyl group. In the state in which a polymerizable component essentially comprising a bifunctional oligomer having a weight average molecular weight (Mw) of 300 or more having two (meth) acryloyl groups in one molecule is emulsified and dispersed in water. An absorption step of absorbing in addition to the siloxane particles; or (2) the solubility in water at 25 ° C. of the polysiloxane particles having no vinyl group is 10% by mass or less, and two per molecule. Polymerizable composition comprising a bifunctional oligomer having a (meth) acryloyl group and a weight average molecular weight (Mw) of 300 or more, and a polymerizable monomer having a vinyl group and a hydrolyzable silyl group. An absorption step of absorbing in addition to the polysiloxane particles in a state in which the emulsified dispersion in water,
A polymerization step of radical polymerization of the polymerizable component absorbed in the polysiloxane particles in the absorption step.

  The absorption step is not particularly limited as long as it proceeds in a state where the polymerizable component is present in the presence of the polysiloxane particles. In the absorption step, the polymerizable component is absorbed in the structure of the polysiloxane particles. The concentration of the polysiloxane particles and the polymerizable component is increased so that the absorption step proceeds promptly. It is preferable to set the mixing ratio of the polysiloxane particles and the polymerizable component, the processing method / means for mixing, the temperature and time at the time of mixing, the processing method / means after mixing, etc., and carry out under the conditions.

  The addition amount of the polymerizable component in the absorption step is preferably 0.01 to 100 times by mass with respect to the mass of the silicon compound used as the raw material for the polysiloxane particles. More preferably, it is 0.5-30 times, More preferably, it is 1-15 times. If the amount added is less than the above range, the amount of the polymerizable component of the polysiloxane particles is reduced, and it may be difficult to obtain polymer fine particles having the above-mentioned mechanical properties. , When the added polymerizable component tends to be difficult to completely absorb in the polysiloxane particles, and unabsorbed polymerizable components remain, so that aggregation between particles tends to occur in the subsequent polymerization stage. There is.

  For mixing the polymerizable component and the polysiloxane particles, the polymerizable component may be added to a solvent in which the polysiloxane particles are dispersed, or the polysiloxane particles may be added to a solvent containing the polymerizable component. Among them, it is preferable to add a polymerizable component in a solvent in which polysiloxane particles are dispersed in advance as in the former, and further, polysiloxane particles are obtained from a polysiloxane particle dispersion obtained by synthesizing polysiloxane particles. It is preferable to add a polymerizable component to the dispersion without taking out the solution because the process is not complicated and the productivity is excellent.

  In the above absorption step, the timing of adding the polymerizable component is not particularly limited, and the polymerizable component may be added all at once, may be added in several times, or fed at an arbitrary rate. May be. In addition, when adding the polymerizable component, the polymerizable component may be added alone or a solution of the polymerizable component may be added, but the polymerizable component is preliminarily emulsified and dispersed with an emulsifier in the polysiloxane particles. It is preferable to add it because the absorption to the polysiloxane particles is performed more efficiently.

  The emulsifier is not particularly limited. For example, an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant, a polymer surfactant, and one or more polymerizable molecules in the molecule. Examples include polymerizable surfactants having a carbon-carbon unsaturated bond. Among these, anionic surfactants and nonionic surfactants are preferable because they can stabilize the dispersion state of polysiloxane particles, polysiloxane particles that have absorbed a polymerizable component, and polymer fine particles. These emulsifiers may be used alone or in combination of two or more.

  Although it does not specifically limit as said anionic surfactant, Specifically, Alkali metal alkyl sulfates, such as sodium dodecyl sulfate and potassium dodecyl sulfate; Ammonium alkyl sulfates, such as ammonium dodecyl sulfate; Sodium dodecyl Polyglycol ether sulfate, sodium sulfosinoate, alkali metal salts of sulfonated paraffin; alkyl sulfonates such as ammonium salt of sulfonated paraffin; fatty acid salts such as sodium laurate, triethanolamine oleate, triethanolamine abiate, Alkyl aryl sulfones such as sodium dodecylbenzene sulfonate and alkali metal sulfate of alkali phenol hydroxyethylene Over preparative like; higher alkyl naphthalene sulfonate, naphthalenesulfonic acid formalin condensates, dialkyl sulfosuccinate, polyoxyethylene alkyl sulfate salts, and polyoxyethylene alkylaryl sulfate salts.

  Although it does not specifically limit as said cationic surfactant, For example, alkyl aryl sulfonates, such as sodium dodecyl benzene sulfonate and alkali metal sulfate of alkali phenol hydroxyethylene; Higher alkyl naphthalene sulfonate, naphthalene sulfonic acid Formalin condensates, dialkyl sulfosuccinates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl aryl sulfate salts and the like can be mentioned.

  The nonionic surfactant is not particularly limited, and specific examples include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and monoglycerol glycerol. Examples thereof include fatty acid monoglycerides such as laurate; polyoxyethyleneoxypropylene copolymers, condensation products of ethylene oxide and fatty acid amines, amides or acids.

  Examples of the amphoteric surfactants include amino acid type amphoteric surfactants and betaine type amphoteric surfactants. Examples thereof include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, and 2-alkyl-N-carboxyethyl. -N-hydroxyethylimidazolinium betaine, N-tetradecyl-N, N-betaine type amphoteric surfactants (for example, “Amogen K” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

  Specific examples of the polymeric surfactant include polyvinyl alcohol, sodium poly (meth) acrylate, potassium poly (meth) acrylate, ammonium poly (meth) acrylate, polyhydroxyethyl (meth) acrylate, poly Two or more kinds of copolymers of hydroxypropyl (meth) acrylate, polyvinyl pyrrolidone and polymerizable monomers which are constituent units of these polymers, copolymers with other monomers, correlation transfer of crown ethers A catalyst etc. are mentioned.

  The polymerizable surfactant is not particularly limited, but examples thereof include sodium propenyl-2-ethylhexylbenzenesulfosuccinate, sulfate of polyoxyethylene (meth) acrylate, polyoxyethylene alkylpropenyl ether ammonium sulfate. Anionic polymerizable surfactants such as salts, phosphoric acid esters of (meth) acrylic acid polyoxyethylene esters; polyoxyethylene alkylbenzene ether (meth) acrylic acid esters, polyoxyethylene alkyl ether (meth) acrylic acid esters, etc. Nonionic polymerizable surfactants and the like can be mentioned.

  The usage-amount of the said emulsifier is not specifically limited, Specifically, it is preferable that it is 0.01-10 mass% with respect to the total weight of the said polymeric component, More preferably, it is 0.05-8. It is 1 mass%, More preferably, it is 1-5 mass%. When the amount of the emulsifier used is less than 0.01% by mass, an emulsion dispersion of a stable polymerizable component may not be obtained. When the amount exceeds 10% by mass, emulsion polymerization or the like occurs as a side reaction. There is a risk of it. About the said emulsification dispersion | distribution, it is preferable to usually make the said polymeric component into an emulsion state in water using a homomixer, an ultrasonic homogenizer, etc. with an emulsifier.

  Moreover, when emulsifying and dispersing the polymerizable component with an emulsifier, it is preferable to use water or a water-soluble organic solvent 0.3 to 10 times the mass of the polymerizable component. Examples of the water-soluble organic solvent include alcohols such as methanol, ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, pentanol, ethylene glycol, propylene glycol, 1,4-butanediol; acetone And ketones such as methyl ethyl ketone; esters such as ethyl acetate;

  The absorption step is preferably performed in the temperature range of 0 to 60 ° C. with stirring for 5 minutes to 720 minutes.

  These conditions may be set as appropriate depending on the type of polysiloxane particles and polymerizable components used, and these conditions may be used alone or in combination of two or more.

  In the above absorption process, whether or not the polymerizable component has been absorbed is determined by observing the particles with a microscope before adding the polymerizable component and after completion of the absorption step, and the particle size is increased by absorption of the polymerizable component. This can be easily determined.

  After completion of the absorption step, it is preferable to dilute by adding water so that the particle concentration in the dispersion of polysiloxane particles having absorbed the polymerizable component is 40% by mass or less. More preferably, it is 30 mass% or less, More preferably, it is 20 mass% or less. This is because if the particle concentration of the dispersion is too high, it may be difficult to control the temperature due to heat generated by the polymerization reaction in the subsequent polymerization step. At this time, in order to improve the dispersion stability of the particles, the above-described surfactant may be additionally added.

  In the polymerization step, the method for radical polymerization is not particularly limited, and examples thereof include a method using a radical polymerization initiator, a method of irradiating ultraviolet rays and radiation, and a method of applying heat. The radical polymerization initiator is not particularly limited, but examples thereof include persulfates such as potassium persulfate, hydrogen peroxide, peracetic acid, benzoyl peroxide, lauroyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-ethylhexanoate, di-t-butyl peroxide, benzoyl peroxide, 1,1-bis (t-butylperoxy)- Peroxide initiators such as 3,3,5-trimethylcyclohexane and t-butyl hydroperoxide; azobisisobutyronitrile, azobiscyclohexacarbonitrile, azobis (2,4-dimethylvaleronitrile), 2'-azobisisobutyronitrile, 2,2'-azobis (2-amidinop Pan) dihydrochloride, 4,4'-azobis (4-cyanopentanoic acid), 2,2'-azobis- (2-methylbutyronitrile), 2,2'-azobisisobutyronitrile, 2 Preferred examples include azo compounds such as 2,2′-azobis (2,4-dimethylvaleronitrile). These radical polymerization initiators may be used alone or in combination of two or more.

  The use amount of the radical polymerization initiator is preferably 0.001% by mass to 20% by mass, more preferably 0.01% by mass to 10% by mass, further based on the total weight of the polymerizable component. More preferably, it is 0.1 mass%-5 mass%. When the usage-amount of the said radical polymerization initiator is less than 0.001 mass%, the polymerization degree of a polymerizable component may not rise. The method of charging the radical polymerization initiator into the solvent is not particularly limited, and a method in which the entire amount is initially charged (before the reaction is started) (a mode in which the radical polymerization initiator is emulsified and dispersed together with the polymerizable component, the polymerizable component is A mode in which a radical polymerization initiator is charged after absorption); a method in which a part is initially charged and the rest is continuously fed, a pulse is intermittently added, or a combination of these is conventionally used Any known method can be employed.

  The reaction temperature for the radical polymerization is preferably 40 to 100 ° C, more preferably 50 to 80 ° C. If the reaction temperature is too low, the degree of polymerization does not increase sufficiently and the mechanical properties of the polymer fine particles tend to be difficult to obtain. On the other hand, if the reaction temperature is too high, aggregation between particles occurs during the polymerization. Tends to occur. The reaction time for the radical polymerization may be appropriately changed according to the type of polymerization initiator used, but is usually preferably 5 to 600 minutes, more preferably 10 to 300 minutes. When the reaction time is too short, the degree of polymerization may not be sufficiently increased, and when the reaction time is too long, aggregation tends to occur between particles.

  Next, the electroconductive particle concerning this invention is demonstrated.

  The conductive particles according to the present invention (hereinafter sometimes referred to as the conductive particles of the present invention) are those in which a conductor layer is formed on the surface of the polymer fine particles described in the present invention. The said conductor layer should just be formed in at least one part of the polymer fine particle surface.

  Since the conductive particles of the present invention have the polymer fine particles of the present invention described above, the hardness and compression deformation recovery rate required to keep the gap distance between a pair of electrically connected electrode substrates constant. In addition, it is difficult to cause physical damage to the electrode. For this reason, it is easy to keep the gap distance between a pair of electrode substrates constant, the conductor layer is peeled off by pressurization, a short between electrodes that should not be electrically connected, and between electrodes that should be electrically connected Can prevent poor contact. Although the metal which can be used for a conductor layer is not specifically limited, For example, nickel, gold | metal | money, silver, copper, indium, these alloys etc. are mentioned. Among these, nickel, gold, and indium are preferable because of high conductivity. Although there will be no limitation in particular if the thickness of the said conductor layer has sufficient conduction | electrical_connection, it is preferable that it is 0.01-5.0 micrometers, More preferably, it is 0.02-2.0 micrometers. If the thickness of the conductor layer is less than 0.01 μm, the conductivity may be insufficient, and if it exceeds 5.0 μm, the conductor layer may be easily peeled off due to the difference in thermal expansion coefficient of the conductor layer. is there. The conductor layer may be one layer or two or more layers, and in the case of two or more layers, different types of metals may be laminated.

  The method for forming the conductor layer on the surface of the polymer fine particles of the present invention is not particularly limited, and a conventionally known method may be used. For example, a chemical plating (electroless plating) method, a coating method, a PVD (vacuum deposition, sputtering, ion plating, etc.) method and the like can be mentioned. Among them, the chemical plating method can easily form a conductor layer. preferable.

  The conductive particles of the present invention thus obtained have the same mechanical properties (hardness and breaking strength) as the polymer fine particles of the present invention. Therefore, it is particularly useful as an electrical connection material for electronics such as liquid crystal display boards, LSIs, and printed wiring boards.

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples are not intended to limit the present invention, and all modifications made without departing from the spirit of the preceding and following descriptions are included in the technical scope of the present invention. The measuring method is as follows.

[Average particle diameter and coefficient of variation of particle diameter (Cv value)]
The average particle size of the polysiloxane particles and polymer fine particles was determined by measuring the particle size of 30000 particles using a Coulter Multisizer (manufactured by Beckman Coulter, Inc.).

The variation coefficient (Cv value) of the particle diameter was obtained according to the following formula.

[10% compression modulus (10% K value: hardness)]
Using a Shimadzu microcompression tester (manufactured by Shimadzu Corporation, MCTW-500), a circular plate indenter (material: 50 μm in diameter) for one sample particle dispersed on a sample table (material: SKS flat plate) at room temperature (25 ° C.) The load and the amount of displacement when the particle is deformed until the compressive displacement becomes 10% of the particle diameter by applying a load at a constant load speed (2.275 mN / sec) to the center of the particle using diamond) (Mm) is measured. The measured compression load, particle compression displacement, and particle radius are expressed as follows:

(Where E: compression elastic modulus (N / mm ² ), F: compression load (N), S: compression displacement (mm), R: radius of particle (mm)). calculate. This operation is performed for three different particles, and the average value is taken as the 10% compression modulus of the polymer fine particles.

[Compression deformation recovery rate (recovery rate)]
Using a micro-compression tester (“MCTW-500” manufactured by Shimadzu Corporation), measure the relationship between the load value and compression displacement when the load is reduced after compressing the sample particles to a reverse load of 9.8 mN. This is the obtained value. When the end point when removing the load is the origin load value of 0.098 mN and the compression speed at the load and the unload is 1.486 mN / sec, the displacement (L1) to the reversal point is The ratio (L1 / L2) to the displacement (L2) from the reversal point to the point where the origin load value is taken is a value expressed as%.

[Displacement at 1 g load (compressibility)]
A circular indenter with a diameter of 50 μm (material: material: one sample particle dispersed on a sample table (material: SKS flat plate) at room temperature (25 ° C.) by a micro compression tester (“MCTW-500” manufactured by Shimadzu Corporation) Using a diamond), a load is applied in the center direction of the particle at a constant load speed, and the amount of particle displacement (L3) at the time of 0.098 mN (1 g load) load is expressed as a ratio (L3 / D) is a value expressed as%.

Experimental example 1
(Preparation of polysiloxane particle dispersion-1)
In a four-necked flask equipped with a condenser, a thermometer, and a dripping port, a solution obtained by mixing 250 parts of water and 20 parts of 25% ammonia water is added and stirred, and 30 parts of γ-methacryloxypropyltrimethoxysilane is added thereto. A mixed solution of 125 parts of methanol and methanol was added from the dropping port, and γ-methacryloxypropyltrimethoxysilane was hydrolyzed and condensed to prepare polysiloxane particles. One hour after the start of the reaction, 250 parts of water was added from the dropping port to dilute the polysiloxane particle slurry. Furthermore, stirring was continued until 2 hours after the start of the reaction to obtain polysiloxane particle dispersion-1. This polysiloxane particle dispersion-1 was sampled and the particle size was measured with a Coulter Multisizer (manufactured by Beckman Coulter). The average particle size was 1.58 μm and the coefficient of variation was 3.37%.

(Preparation of polymerizable component emulsion-1)
0.7 part of anionic emulsifier (Daiichi Kogyo Seiyaku, LA-10), 70 parts of water, bifunctional oligomer as a polymerizable component (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester APG-400, weight average molecular weight: 508 , 100 parts by weight in water (25 ° C.): 0.02 mass%), 20 parts 1,6-hexanediol dimethacrylate, and 2,2′-azobis (2,4-dimethylvaleronitrile as radical polymerization initiator) ) (Wako Pure Chemical Industries, Ltd., V-65) 0.5 part was mixed and emulsified and dispersed using a homogenizer for 5 minutes to prepare a polymerizable component emulsion-1.

(Preparation of polymer fine particle-1)
The polysiloxane particle dispersion-1 was further stirred for 30 minutes, and then polymerizable component emulsion-1 was added in 15 seconds from the dropping port provided in the flask. After stirring for 30 minutes after the addition of the polymerizable component, the polysiloxane particles were observed with a microscope, and as a result, the particle size was increased as compared to before the addition of the polymerizable component. It was confirmed that it was absorbed.

  One hour after the addition of the polymerizable component emulsion, 1000 parts of water was added to the polysiloxane particle dispersion that absorbed the polymerizable component, the temperature was raised to 75 ° C. under a nitrogen atmosphere, and the mixture was held for 30 minutes to perform radical polymerization. .

  After radical polymerization, the obtained emulsion was solid-liquid separated by natural sedimentation (decantation), and the resulting cake was washed with methanol and then vacuum dried at 120 ° C. for 2 hours to obtain polymer fine particles-1. Obtained. Table 1 also shows the average particle size, coefficient of variation, and other characteristics of the obtained polymer fine particles-1.

(Manufacture of conductive fine particles)
After electroless Ni plating was performed on the polymer fine particles-1, electroless gold plating was further performed to obtain conductive fine particles-1. When the obtained conductive fine particle-1 was observed with SEM (scanning electron microscope) and XMA (X-ray microanalyzer), the surface of the conductive fine particle was coated with Ni and plated with gold thereon. .

Experimental example 2
(Preparation of polysiloxane particle dispersion-2)
A polysiloxane particle dispersion-2 was prepared in the same manner as in Experimental Example 1 except that the amount of 25% aqueous ammonia was 15 parts (average particle size: 2.53 μm, coefficient of variation: 2.84%).

(Preparation of polymerizable component emulsion-2)
As polymerizable components, 75 parts of bifunctional oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester APG-700, weight average molecular weight: 808, solubility in water (25 ° C.): 0.008% by mass), 1,6 -Polymerizable component emulsion-2 was prepared in the same manner as in Experimental Example 1, except that 45 parts of hexanediol dimethacrylate was used.

(Preparation of polymer fine particle-2)
After stirring the polysiloxane particle dispersion-2 for 30 minutes, the polymerizable component emulsion-2 was added in 15 seconds from the dropping port provided in the four-necked flask. After stirring for another 30 minutes after addition of the polymerizable component emulsion, the polysiloxane particles were observed with a microscope, and it was confirmed that the polysiloxane particles absorbed the polymerizable components by increasing the particle diameter. One hour after the addition of the polymerizable component emulsion, 1000 parts of water was added to the polysiloxane particle dispersion that absorbed the polymerizable component, and the reaction solution was heated to 75 ° C. in a nitrogen atmosphere and held at 75 ° C. for 30 minutes. Then, radical polymerization was performed.

  Thereafter, polymer fine particles-2 were separated and washed in the same manner as in Experimental Example 1. The average particle size, coefficient of variation, and other characteristics of the obtained polymer fine particle-2 are also shown in Table 1.

Experimental example 3
(Preparation of polymerizable component emulsion-3)
As a polymerizable component of the polymerizable component emulsion, 100 parts of a bifunctional oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester 9PG, weight average molecular weight: 536, solubility in water (25 ° C.): 0.012% by mass), A polymerizable component emulsion-3 was prepared in the same manner as in Experimental Example 2, except that 20 parts of n-butyl methacrylate was used.

(Polymer fine particle-3)
Polymer fine particles-3 were obtained in the same manner as in Experimental Example 2, except that the polymerizable component emulsion-3 was used. The average particle diameter, coefficient of variation, and other characteristics of the obtained polymer fine particles-3 are also shown in Table 1.

Experimental Example 4
(Preparation of polymerizable component emulsion-4)
As a polymerizable component of the polymerizable component emulsion, 60 parts of bifunctional oligomer (manufactured by Kyoeisha Chemical Co., Ltd., light acrylate PTMGA250, weight average molecular weight: 342, solubility in water (25 ° C.): 0.028% by mass), and styrene A polymerizable component emulsion-4 was prepared in the same manner as in Experimental Example 1 except that 60 parts were used.

(Preparation of polymer fine particle-4)
Polymer fine particles-4 were obtained in the same manner as in Experimental Example 2 except that the polymerizable component emulsion-4 was used. Table 1 also shows the average particle size, coefficient of variation, and other characteristics of the obtained polymer fine particles-4.

Experimental Example 5
(Preparation of polysiloxane particle dispersion-3)
A polysiloxane particle dispersion-3 was obtained in the same manner as in Experimental Example 2, except that 30 parts of phenyltrimethoxysilane was used instead of γ-methacryloxypropyltrimethoxysilane for the preparation of the polysiloxane particle dispersion ( (Average particle diameter: 2.33 μm, coefficient of variation: 3.34%).

(Preparation of polymerizable component emulsion-5)
As in Example 2, except that 120 parts of a bifunctional oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester 9PG) and 30 parts of γ-methacryloxypropylmethyldimethoxysilane (MPDS) were used as the polymerizable component. A polymerizable component emulsion-5 was obtained.

(Preparation of polymer fine particle-5)
Using the polysiloxane particle dispersion-3 and the polymerizable component emulsion-5 obtained as described above, polymer fine particles-5 were prepared in the same manner as in Experimental Example 1. The average particle size, coefficient of variation, and other characteristics of the obtained polymer fine particles-5 are also shown in Table 1.

Experimental Example 6
(Preparation of polysiloxane particle dispersion-4)
A polysiloxane dispersion-4 was prepared in the same manner as in Experimental Example 1 except that the amount of 25% aqueous ammonia was 4 parts (average particle size: 5.08 μm, coefficient of variation: 2.48%).

(Preparation of polymerizable component emulsion-6)
Anionic emulsifier (Daiichi Kogyo Seiyaku Co., Ltd., LA-10) 1.5 parts, water 150 parts, bifunctional oligomer as a polymerizable component (manufactured by Nippon Kayaku Co., Ltd., KAYARAD HX-220, weight average molecular weight: 540, 100 parts of water (solubility in water (25 ° C.): 0.01% by mass), 20 parts of 1,9-nonanediol dimethacrylate, and 2,2′-azobis (2,4-dimethylvaleronitrile) 1 as a radical polymerization initiator The components were mixed and emulsified and dispersed for 5 minutes using a homogenizer to prepare a polymerizable component emulsion-6.

(Preparation of polymer fine particle-6)
Using the polysiloxane particle dispersion-4 and the polymerizable component emulsion-6 obtained as described above, polymer fine particles-6 were prepared in the same manner as in Experimental Example 1. The average particle size, coefficient of variation, and other characteristics of the obtained polymer fine particles-6 are also shown in Table 1.

Experimental Example 7
(Preparation of polysiloxane particle dispersion-5)
A polysiloxane particle dispersion-5 was prepared in the same manner as in Experimental Example 1 except that the amount of γ-methacryloxypropyltrimethoxysilane was changed to 40 parts (average particle size: 2.12 μm, coefficient of variation) : 3.27%).

(Preparation of polymerizable component emulsion-7)
Polymerizable component emulsion as described in Experimental Example 1 except that 70 parts of styrene was used as the polymerizable component and 0.55 part of 2,2′-azobis (2,4-dimethylvaleronitrile) was used as the radical polymerization initiator. 7 was prepared.

(Preparation of polymer fine particle-7)
Polymer fine particles-7 were prepared in the same manner as in Experimental Example 1 using the polysiloxane particle dispersion-5 and the polymerizable component emulsion-7 obtained as described above. The average particle size, coefficient of variation, and other characteristics of the obtained polymer fine particles-7 are also shown in Table 1.

Experimental Example 8
(Preparation of polymerizable component emulsion-8)
90 parts of a bifunctional oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A-400, weight average molecular weight: 508, solubility in water (25 ° C.): 11.2% by mass), n- A polymerizable component emulsion-8 was prepared in the same manner as in Experimental Example 2 except that the amount was changed to 30 parts of butyl methacrylate.

(Preparation of polymer fine particle-8)
Using the polysiloxane dispersion-2 and the polymerizable component emulsion-8, absorption of the polymerizable component and radical polymerization were performed in the same manner as in Experimental Example 1. However, agglomeration occurred during the polymerization reaction, resulting in the formation of a precipitate, which could not be isolated as particles.

Experimental Example 9
In a four-necked flask equipped with a condenser, thermometer, and dripping port, under a nitrogen stream, 150 parts of isopropanol were charged with 2 parts of polyvinylpyrrolidone (PVP, weight average molecular weight Mw: 30,000) and 1 part of azobismethylvaleronitrile. The dissolved solution was stirred and 15 parts of styrene was added thereto. Thereafter, the mixture was heated to 600 ° C. and polymerized for 24 hours to obtain polystyrene particles (average particle size: 5.1 μm, coefficient of variation: 7.3%).

Experimental Example 10
(Preparation of polymerizable component emulsion-10)
A polymerizable component emulsion-10 was prepared in the same manner as in Experimental Example 2 except that divinylbenzene (96% purity, manufactured by Nippon Steel Chemical Co., Ltd.) was used as the polymerizable component.

(Preparation of polymer fine particles)
Polymer fine particles were prepared in the same manner as in Experimental Example 2 except that the polymerizable component emulsion-10 was used. Table 1 also shows the average particle size, coefficient of variation, and other characteristics of the polymer fine particles obtained.

  In Table 1, 16HX is 1,6-hexanediol dimethacrylate (molecular weight: 254), St is styrene (molecular weight: 104), BMA is n-butyl methacrylate (molecular weight: 142), 19ND is 1,9-nonanediol Dimethacrylate (molecular weight: 196) and DVB mean divinylbenzene (molecular weight: 130), respectively.

  The polymer fine particles of Experimental Examples 1 to 6 are examples in which a bifunctional oligomer having a solubility in water at 25 ° C. of 10% by mass or less and a weight average molecular weight of 300 or more is used as a polymerizable component. From this, it can be seen that all the polymer fine particles are flexible and have high elasticity.

  On the other hand, Experimental Examples 7 to 10 are examples in which a specific bifunctional oligomer was not used as the polymerizable component. Experimental Example 7 was an example in which only styrene was used as the polymerizable component. Although the amount of mutation (compression rate) at 1 g load was large, it was hard and the compression deformation recovery rate was low. In Experimental Example 8, since the bifunctional oligomer used as the polymerizable component has high solubility in water, the polymerizable component is not sufficiently absorbed in the polysiloxane particles and remains in the reaction solution. As a result, radical polymerization is performed. It is considered that the polymer produced by the reaction and the polysiloxane particles were aggregated and could not be isolated as polymer fine particles. Experimental Example 9 is an example of polymer fine particles composed only of an organic component having no polysiloxane skeleton, and has a flexibility that can be sufficiently deformed even at a low pressure, but has a low compression deformation recovery rate. Experimental Example 10 is an example in which only divinylbenzene was used as the polymerizable component, and the polymer fine particles obtained at this time had excellent compression deformation recovery rate, but had a mutation amount (compression rate) at 1 g load. It was a small one.

From these experimental examples, according to the production method of the present invention, it is possible to easily adjust the particle size of the polymer fine particles, and it is possible to produce polymer fine particles having a narrow particle size distribution even when the particle size is small. I understand.

Claims (7)

  Polysiloxane having a vinyl group and a bifunctional oligomer having a solubility in water at 25 ° C. of 10% by mass or less and having two (meth) acryloyl groups in one molecule and having a weight average molecular weight (Mw) of 300 or more. Polymer fine particles obtained by polymerizing a polymerizable component having an essential component.   2. The polymer fine particles according to claim 1, having an average particle diameter of 1 to 1000 μm and a Cv value of 20% or less. 3. The weight according to claim 1, wherein a compression elastic modulus (10% K value) when the diameter of the polymer fine particles is displaced by 10% is 2450 N / mm ² or more, and a compression deformation recovery rate is 15% or more. Combined fine particles.   The polymer according to any one of claims 1 to 3, wherein a displacement amount of the polymer fine particles at a load of 1 g is 30% or more with respect to a diameter of the polymer fine particles, and a compression deformation recovery rate is 15% or more. Fine particles. Bifunctional polysiloxane particles having a vinyl group having a solubility in water of 25 ° C. of 10% by mass or less and having two (meth) acryloyl groups in one molecule and having a weight average molecular weight (Mw) of 300 or more. An absorption step of absorbing in addition to the polysiloxane particles in a state in which a polymerizable component having an oligomer as an essential component is emulsified and dispersed in water;
A polymerization step for polymerizing the polymerizable component absorbed in the polysiloxane particles in the absorption step;
A method for producing polymer fine particles, comprising: A polysiloxane particle having no vinyl group has a solubility in water at 25 ° C. of 10% by mass or less and a weight average molecular weight (Mw) of 300 or more having two (meth) acryloyl groups in one molecule. An absorption step in which a polymerizable component having a bifunctional oligomer and a polymerizable monomer having a vinyl group and a hydrolyzable silyl group as essential components is added to the polysiloxane particles in an emulsified and dispersed state in water, and absorbed.
A polymerization step for polymerizing the polymerizable component absorbed in the polysiloxane particles in the absorption step;
A method for producing polymer fine particles, comprising: Conductive fine particles, wherein a conductor layer is formed on the surface of the polymer fine particles according to claim 1.