KR20110053459A - Electroconductive particles and anisotropic electroconductive material using the same - Google Patents

Abstract

The conventional conductive metal layer applying process can be greatly simplified, the conductive layer can be uniformly coated on the surface of the substrate particles, the adhesion between the substrate particles and the conductive metal layer is excellent, and there are very few defects such as cracks in the conductive metal layer. Electroconductive fine particles and the anisotropic conductive material using these electroconductive fine particles are provided. M / C (atomic number ratio, M represents the sum of the atomic number of the alkali metal element and the atomic number of the nitrogen element) after the sodium adsorption treatment measured by X-ray photoelectron spectroscopy (ESCA) is 0.5 × 10. It is a conductive fine particle which has a substrate particle which consists of a vinyl polymer of more than ^-2 , hydrophobicity less than 2%, and a mass mean particle diameter of 1000 micrometers or less, and the conductive metal layer which coat | covers the surface of a substrate particle, The said electroconductive fine particle is the said It is obtained by forming a conductive metal layer on the surface of a substrate particle by an electroless plating method.

Description

ELECTROCONDUCTIVE PARTICLES AND ANISOTROPIC ELECTROCONDUCTIVE MATERIAL USING THE SAME

The present invention relates to conductive fine particles and an anisotropic conductive material using the conductive fine particles.

Every year, electronic devices are being miniaturized and thinned and highly functionalized. For example, a conventional solder (solder) may be used for electrical connection between micro-sites of electronic equipment, such as the connection between the ITO electrode of the liquid crystal display panel and the driving LSI, the connection between the LSI chip and the circuit board, and the connection between the fine pattern electrode terminal. And the connection by the connector, the application of the electrical connection using the anisotropic conductive material containing electroconductive fine particles is expanded.

Electroconductive fine particles are widely used as a main constituent material of an anisotropic conductive material, and are generally mixed with binder resin etc., and processed into the form of an anisotropic conductive film, an anisotropic conductive paste, a conductive adhesive, and a conductive adhesive.

Conventionally, although metal particles, such as gold, silver, and nickel, have been used as electroconductive fine particles, since these metal particles have a large specific gravity and are not uniform in shape, it may be difficult to disperse | distribute uniformly in binder resin, and electroconductivity of a conductive material It was the cause of causing nonuniformity.

Moreover, as electroconductive fine particles, the electroconductive microparticles | fine-particles which made inorganic fine particles and organic resin microparticles | fine-particles of uniform particle diameters as a base particle, and coat | covered the surface of this base particle with metals, such as nickel, by the electroless plating method exist (patent document 1- 4).

Since these conductive fine particles have a uniform particle diameter, it is unlikely that problems of conductivity such as those of metal particles are used, but plating layers are peeled off from substrate particles or plating cracks are likely to occur, and conductive fine particles have been pressed onto substrates or electrode terminals. At the time, there existed a problem that electroconductivity fell.

In general, in the electroless plating method, in order to improve the adhesion between the substrate particles and the plating layer, prior to the electroless plating, degreasing treatment of the substrate particles, etching treatment to form minute irregularities on the surface of the substrate particles, and a catalyst on the surface of the substrate particles are performed. Pretreatment processes, such as catalyzed treatment, are carried out.

However, since the substrate particles are exposed to an oxidizing agent such as chromic acid or sulfuric acid in the degreasing treatment as the pretreatment of the substrate particles, and the etching treatment, the strength of the substrate particles is thereby lowered, and the required pressure resistance performance is achieved. This deteriorates. In addition, there is a problem of drainage of heavy metals containing chromium and a problem that chromium components remain on the surface of the substrate particles, and considering the load on the environment, improvement of the process has been desired.

For the purpose of improving the adhesion between the conductive metal layer and the substrate particles, a resin coating layer containing a functional group having a binding ability with a metal ion is formed on the surface of the substrate particles, or for the same purpose, at the time of polymerization of the substrate particles, a carboxyl group and a sulfone group. The technique which uses the dispersion stabilizer which has at least 1 sort (s) of functional group chosen from, or uses the polymerizable monomer which has the said functional group as a raw material of a substrate particle is also proposed (patent document 5, 6).

Although the substrate particles obtained by the above technique can be formed without the etching treatment, the coating film can be formed, but it is not sufficient in terms of adhesion between the substrate particles and the metal layer, and the cracks of the plating film are completely eliminated. It wasn't possible.

Moreover, when forming a conductive metal layer on the surface of a polymer microparticle, Patent Document 7 discloses a coating layer of a conductive metal after introduction of a peroxide group and / or a hydroxyl group on the surface of the polymer microparticle by selective low temperature plasma treatment and selectively hydrophilized. A method of forming is disclosed.

Japanese Patent Publication No. H06-96771 Japanese Laid-Open Patent Publication No. 2000-243132 Japanese Laid-Open Patent Publication No. 2003-64500 Japanese Laid-Open Patent Publication No. 2003-68143 Japanese Laid-Open Patent Publication No. 2003-208813 Japanese Laid-Open Patent Publication No. 2005-325382 Japanese Laid-Open Patent Publication No. 2007-184278

According to the method disclosed in Patent Document 7, the aggregation of the substrate particles in the plating treatment can be prevented to some extent, and the occurrence of defects in the plating film resulting from the aggregation of the substrate particles can be suppressed. However, in terms of improving the adhesion between the polymer fine particles and the conductive metal layer, the effect of only the peroxide group and / or the hydroxyl group introduced to the particle surface is insufficient, and further, the etching treatment is performed by degreasing treatment, chromic acid or the like. It was necessary to form an anchor on the substrate particle surface.

In addition, with recent rapid advances in electronic devices, further improvement in reliability is required in conductive materials such as anisotropic conductive materials, and poor conductivity or conduction caused by peeling or plating cracks between the substrate particles and the conductive metal layer. There is a desire for a highly reliable material having further reduced stability failures. As described above, various techniques for improving the adhesion between the substrate particles and the conductive metal layer have been proposed, but there has been room for further improvement in order to satisfy the recent demand level.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described situation, and it is possible to greatly simplify the conventional conductive metal layer applying process, and to uniformly coat the conductive layer on the surface of the substrate particles, and to adhere the adhesion between the substrate particles and the conductive metal layer. An object of the present invention is to provide conductive fine particles having very high defects and very few defects such as cracks in the conductive metal layer, and anisotropic conductive materials using the conductive fine particles.

The electroconductive fine particles of this invention are electroconductive fine particles which have a base particle and the electroconductive metal layer which coat | covers the surface of a base particle, The said base particle is a base particle which consists of a vinyl-type polymer with a mass mean particle diameter of 1000 micrometers or less, and is described by the following method After the particles were subjected to sodium adsorption, the ratio M / C (atomic ratio) of the total amount of the number of atoms of the alkali metal and the nitrogen to the number of atoms of carbon measured by X-ray photoelectron spectroscopy (ESCA) was 0.5 × 10 ^−2. The hydrophobicity is less than 2%.

Sodium adsorption treatment

20 mass parts of aqueous solution which melt | dissolved sodium hydroxide so that the density | concentration might be 0.1 mass%, and 1 mass part of particle | grains were mixed with the mixed solution of water: methanol in mass ratio 1: 1, and this suspension was stirred at 25 degreeC for 1 hour, , Solid-liquid separation, solvent washing and vacuum drying at 120 캜 for 2 hours.

The electroconductive fine particles of this invention have the base particle which shows the alkali metal content and hydrophobicity degree of the said range, In order to have the high hydrophilicity, the said base particle is excellent in adhesiveness of a base particle and the metal which coat | covers the surface, Since agglomeration between substrate particles is unlikely to occur, defects are less likely to occur in the conductive metal layer.

It is preferable that the said base particle is 0.5x10 <^-2> or more M / C before a sodium adsorption process. It is also preferable that the acid value of the substrate particles before the sodium adsorption treatment is 0.05 mgKOH / g or more. In addition, the alkali metal is preferably sodium.

The coefficient of variation of the particle diameter of the substrate particles is preferably 15% or less, and the substrate particles preferably have a carboxyl group and / or carboxylate group (COOM, M represents an alkali metal ion or an amine cation) on the surface. .

The electroconductive fine particles of this invention also include what has an insulating resin layer in at least one part of the surface.

An anisotropic conductive material using the conductive fine particles is a preferred embodiment of the present invention.

According to the present invention, since conductive fine particles having excellent adhesion between the substrate particles and the conductive metal layer are obtained even without performing a pretreatment step of degreasing treatment and etching treatment, the conventional conductive metal applying step can be greatly simplified, and at the same time, the substrate particles. The electroconductive metal layer excellent in adhesiveness with can be formed uniformly on the surface of a substrate particle. In addition, since the conductive fine particles of the present invention have excellent adhesion between the substrate particles and the conductive metal layer, cracks or peeling of the conductive metal layer are less likely to occur, and the anisotropic conductive material using the same can maintain electrical connection between the electrode substrates over a long period of time. It is highly reliable.

1 is an SEM image of the conductive fine particles obtained in Example 6. FIG.
2 is an SEM image of the conductive fine particles obtained in Example 9. FIG.
3 is an FE-SEM image of the conductive fine particles obtained in Example 9. FIG.
4 is a graph showing the results of elemental analysis of the conductive fine particles obtained in Example 9. FIG.
5 is a cross-sectional FE-SEM image of the conductive fine particles obtained in Example 9. FIG.

<Conductive Fine Particles>

The electroconductive fine particles of this invention are electroconductive fine particles which have a base particle and the electroconductive metal layer which coat | covers the surface of a base particle, The said base particle is a base particle which consists of a vinyl-type polymer with a mass mean particle diameter of 1000 micrometers or less, and adsorb | sucks a base particle with sodium After treatment, the ratio M / C of the number of atoms of the alkali metal and the nitrogen to the number of atoms of the carbon measured by X-ray photoelectron spectroscopy (ESCA) (atomic ratio, M is the number of atoms of the alkali metal and the number of nitrogen atoms) in total, C denotes the number of carbon atom) is 0.5 × 10 ^- not less than ^2, and also, it has a feature that the hydrophobic degree is less than 2%.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined in order to provide the electroconductive fine particle which is excellent in the adhesiveness of a base material particle and a conductive metal layer, without damaging the mechanical property of a base particle itself, As a result, the surface of a base particle is based on a specific acidic functional group. When it showed, the adhesiveness of a base material particle and a conductive metal layer became favorable, and it discovered that the mechanical property of a particle | grain is not impaired also before and after coating | covering a conductive metal layer, and completed this invention.

The base particles according to the present invention are subjected to sodium adsorption treatment by the following method, and then the ratio of the abundance of alkali metal elements and nitrogen elements to the abundance of carbon elements measured by X-ray photoelectron spectroscopy (ESCA) M / C is 0.5 × 10 ⁻² or more. As will be described later, the substrate particles according to the present invention have a carboxyl group as one of the acidic functional groups on the surface thereof, whereby the surface of the substrate particles is hydrophilized, and the adhesion between the substrate particles and the conductive metal layer is good. . However, according to the present inventors, the detailed reason is not clear, but when the alkali metal element is adsorbed to the substrate particles, or when the carboxyl group and alkali metal ions or amine cations present on the surface of the substrate particles form a salt. It has been found that the adhesion between the substrate particles and the conductive metal layer is further improved. It is preferable that M / C is 1.0 * 10 <^-2> or more, More preferably, it is 1.5 * 10 <^-2> or more. On the other hand, although the upper limit of M / C is not specifically limited, Preferably it is 30 * 10 <^-2> or less, More preferably, it is 20 * 10 <^-2> or less, More preferably, it is 13 * 10 <^-2> or less, More preferably Preferably it is 10 * 10 <^-2> or less, Most preferably, it is 8 * 10 <^-2> or less.

Sodium adsorption treatment

20 mass parts of aqueous solution which melt | dissolved sodium hydroxide so that the density | concentration might be 0.1 mass%, and 1 mass part of particle | grains were mixed with the mixed solution of the water: methanol ratio of 1: 1 by mass ratio, and this suspension was mixed at 25 degreeC for 1 hour. Stir. However, when the substrate particles are hard to get wet with water, the substrate particles are added to methanol in advance, and then, an aqueous sodium hydroxide solution and / or water are added thereto to prepare the same composition as the suspension.

Subsequently, the suspension is subjected to solid-liquid separation, the substrate particles are washed with 100 parts by mass of ion-exchanged water, and then the substrate particles are washed with 33 parts by mass of methanol. After washing, the obtained substrate particles are vacuum dried at 120 캜 for 2 hours.

Moreover, it is preferable that the substrate particle before the said sodium adsorption treatment also has M / C (atomic ratio) measured by X-ray photoelectron spectroscopy (ESCA) of 0.5x10 <^-2> or more. It is preferable that it is the form in which the alkali metal adsorb | sucks to a substrate particle, or the form in which the alkali metal salt and amine salt of carboxylic acid exist in the surface of a substrate particle. That is, regardless of the presence or absence of sodium adsorption treatment, when M / C is in the above range, the adhesion (plating property) of the conductive metal layer is good. Therefore, the preferable range of M / C of the substrate particle before sodium adsorption treatment is also the same range as the substrate particle M / C after sodium adsorption treatment. In addition, M is the abundance of alkali metal atoms and nitrogen atoms on the measured substrate particle surface, and C represents the abundance of carbon atoms. The nitrogen atom is a component derived from an amine salt. The alkali metal to be measured includes lithium, potassium, rubidium, cesium and the like, in addition to sodium which can be used for the sodium adsorption treatment, but is preferably sodium.

In addition, the degree of hydrophilicity of a substrate particle can be represented by the degree of hydrophobicity and the acid value mentioned later. The degree of hydrophobicity of the substrate particles according to the present invention is preferably less than 2%, more preferably 1% or less, still more preferably 0.5% or less, and most preferably 0%. The degree of hydrophobicity can be calculated as follows.

[Hydrophobicity]

50 cc of ion-exchanged water was put into a 200 cc glass beaker with a stirrer at the bottom, and 0.2 g of particles were placed on the water surface, and then the stirrer was slowly rotated. Thereafter, the tip of the burette is settled in the water in the beaker and methanol is slowly introduced from the burette 5 minutes after the addition of the particles while gently rotating the stirrer. The introduction of methanol was continued until the total amount of the particles in the water completely submerged in water, the amount of methanol introduced (cc) when the particles were completely submerged in water was measured, and the degree of hydrophobicity was required based on the following equation. do.

Degree of Hydrophobicity (%) = Methanol Introduction (cc) × 100 / {Amount of Water (cc) + Methanol Introduction (cc)}

Here, before adding methanol from a burette, when the particle which floated on the surface completely submerged in water, it was determined as 0% of hydrophobicity.

The electroconductive fine particles of this invention have a conductive metal layer which coat | covers the surface of a substrate particle. Although it does not specifically limit as a metal which comprises the said conductive metal layer, For example, gold, silver, copper, platinum, iron, lead, aluminum, chromium, palladium, nickel, rhodium, ruthenium, antimony, bismuth, germanium, tin, And metals such as cobalt, indium and nickel-phosphorus, and nickel-boron, metal compounds, and alloys thereof. Among these, nickel, gold, silver, and copper are preferable because they are excellent in conductivity and inexpensive industrially.

It is preferable that the thickness of the said conductive metal layer is 10 nm-500 nm. More preferably, they are 20 nm-400 nm, More preferably, they are 50 nm-300 nm. When the thickness of the conductive metal layer is too thin, it is difficult to maintain stable electrical connection when the conductive fine particles are used as the anisotropic conductive material. On the other hand, when the conductive metal layer is too thick, the hardness of the surface of the conductive fine particles is too high, and there is a possibility that the mechanical properties of the substrate particles such as the recovery rate cannot be sufficiently utilized.

Moreover, it is preferable that a conductive crack does not exist in the surface, and the surface in which a conductive metal layer is not formed does not exist. Here, "a real crack and the surface in which a conductive metal layer is not formed" means the crack of a conductive metal layer, and a base material, when the surface of arbitrary 10000 electroconductive fine particles is observed using the electron microscope (1000 times magnification). It means that the exposure of the particle surface is substantially not observed visually. The detailed evaluation method is mentioned later.

The electroconductive fine particles of this invention may have an insulating resin layer further on the surface of a conductive metal layer. The insulating resin layer is not particularly limited as long as it can ensure insulation between particles of the conductive fine particles and easily disintegrate or peel off the insulating resin layer by a constant pressure and / or heating. For example, polyolefins, such as polyethylene, an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer, in addition to resin same as the vinyl polymer microparticles | fine-particles mentioned later; (Meth) acrylate polymers and copolymers such as polymethyl (meth) acrylate, polyethyl (meth) acrylate and polybutyl (meth) acrylate; Block polymers such as polystyrene, styrene-acrylic acid ester copolymers, SB type styrene-butadiene block copolymers, SBS type styrene-butadiene block copolymers, and hydrogenated compounds thereof; Thermoplastic resins such as vinyl polymers and copolymers, and particularly crosslinked products thereof; Thermosetting resins such as epoxy resins, phenol resins and melamine resins; Water-soluble resins such as polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, methyl cellulose, and mixtures thereof.

However, when an insulating resin layer is too hard compared with vinyl polymer microparticles | fine-particles, there exists a possibility that the substrate particle itself may be destroyed before destruction of an insulating resin layer. Therefore, it is preferable to use uncrosslinked or relatively low crosslinking resin for the insulating resin layer.

The insulating resin layer may be a single layer or may be composed of a plurality of layers. For example, a single or a plurality of encapsulated layers may be formed, or particles having insulating, granular, spherical, blocky, flaky or other shapes attached to the surface of the conductive fine particles, and further, It may be formed by chemically changing the surface, or may be a combination thereof.

It is preferable that the thickness of the said insulating resin layer is 0.01 micrometer-1 micrometer. More preferably, they are 0.1 micrometer-0.5 micrometer. If the thickness of the insulating resin layer is too thin, electrical insulation will be insufficient. On the other hand, if the thickness of the insulating resin layer is too thick, the conduction characteristics may be lowered.

[Subscriber]

Next, the substrate particle which concerns on this invention is demonstrated.

The substrate particle according to the present invention is subjected to a treatment of contacting the vinyl polymer fine particles with a mixed gas comprising essentially a fluorine gas and a gas of a compound containing an oxygen atom, thereby making the surface of the vinyl polymer fine particles hydrophilic. It is preferable that it is. By the said process, the surface of a substrate particle becomes hydrophilic and it becomes what has a specific acid value. The processing will be described later in detail.

In the present invention, the amount of acidic functional groups on the surface of the substrate particle is determined based on the acid value, and this can be used as an index of the degree of hydrophilicity. The acid value of the substrate particles is preferably 0.05 mgKOH / g or more, more preferably 0.1 mgKOH / g or more, and more preferably 1.0 mgKOH / g or more. If the acid value is too low, the hydrophilicity of the particles becomes insufficient, and when the conductive metal layer is coated by electroless plating or the like, the dispersibility of the particles in the aqueous medium decreases, and the adhesion between the coated conductive metal layer and the substrate particles is reduced. There is a possibility of deterioration. In addition, when alkali washing mentioned later is performed, the hydrogen atom of the carboxy group produced | generated on the substrate particle is substituted by the alkali metal atom. Therefore, in hydrophilic microparticles | fine-particles after alkali washing, the degree of hydrophilicity cannot be evaluated by acid value.

The acid value is a value calculated from the measurement result of KOH neutralization amount. The measuring method of KOH neutralization amount is mentioned later.

It is preferable that the substrate particle which concerns on this invention has a carboxy group on the surface. By the presence of a carboxyl group, the surface of a substrate particle becomes hydrophilic and the adhesiveness of a substrate particle and an electroconductive metal layer improves. The presence or absence of a carboxyl group on the surface of a substrate particle can be confirmed by an X-ray photoelectron analyzer (ESCA) etc.

Further, the substrate particles according to the present invention may have -C (F) = O on the surface thereof in addition to the carboxyl group, and covalently bonded to the carbon of the hydrocarbon as a fluorine component in addition to these groups on the surface or inside of the particle. It may have a fluorine component (also called covalent fluorine). Covalently bonded fluorine is coexisted with —C (F) ═O and / or a carboxyl group, and in order to have an effect of suppressing secondary aggregation between the particles, it is preferable that even a small amount is present.

Moreover, hydrogen fluoride (HF) may be affixed to the base particle of this invention as a fluorine component. Since this HF may be harmful in handling the substrate fine particles of the present invention, the smaller the adhesion amount, the more preferable. More preferably, no HF is attached.

These fluorine components can be distinguished by the content of elutable fluorine and non-elutable fluorine. That is, in the elution test mentioned later, the fluorine which ionizes and elutes in a solvent is called elutable fluorine, and its content is called elutable fluorine content. The elutable fluorine includes fluorine derived from the adherent (free) hydrogen fluoride and fluorine derived from -C (F) = O.

On the other hand, in the dissolution test, fluorine which does not elute is non-elutable fluorine, and its content is non-elutable fluorine content. The non-elutable fluorine generally corresponds to the above-mentioned covalent fluorine, but in some cases, a free fluorine component may be contained in the particles and cannot be eluted.

Elutable fluorine content and non-elutable fluorine content are represented by content (mg / g) of fluorine atom conversion contained in 1 g of particles.

As a result of examining the safety and characteristics of the substrate particles, it is preferable that some of the non-releasing fluorine is present. Specifically, the range of 0.1 mg / g to 50 mg / g is preferable because the above-described effect of suppressing secondary aggregation is expressed. However, when too much, hydrophilicity may become inadequate or the mechanical properties of a particle may fall. More preferable non-releasing fluorine content is 1 mg / g-40 mg / g, More preferably, it is 2 mg / g-20 mg / g.

On the other hand, in the case of handling the substrate particles, the content of the elutable fluorine is preferably small or does not exist, and more preferably, less than 1 mg / g. It is more preferable that it is 0.5 mg / g or less, It is further more preferable that it is 0.2 mg / g or less, It is still more preferable that it is 0.1 mg / g or less, It is especially preferable that it is 0.01 mg / g or less.

Moreover, it is preferable that the amount F / C (atomic ratio) of the fluorine atom with respect to the carbon atom which exists in the surface of the substrate particle measured by ESCA is 0.5 * 10 <^-2> -30 * 10 <^-2> . More preferably, they are 1 * 10 <^-2> -20 * 10 <^-2> .

In addition, it is preferable that the substrate particle which concerns on this invention is excellent in the dispersibility in alkaline solution. In particular, it is preferable that the dispersion state of the substrate particles in the alkaline solution and the dispersion state of the substrate particles in ion-exchanged water containing a dispersant are equal. Thus, when a substrate particle is excellent in the dispersibility in alkaline solution, it is because agglomeration of a substrate particle is hard to generate | occur | produce in a plating process mentioned later, and plating property becomes favorable.

For example, it is preferable that the value of (alpha) (dispersibility in alkali solution) computed by the following formula for dispersibility in the alkali solution of a substrate particle is 3% or less. More preferably 2% or less.

α (%) = (| Da-Db | / Db) × 100

Here, Da represents the average dispersed particle diameter of the substrate particle in alkaline solution, and oil represents the average dispersed particle diameter of the substrate particle in ion-exchange water containing a dispersing agent. Da was added 1 part of substrate particles to 20 parts of 0.1 mass% sodium hydroxide aqueous solution (a mixed solution of water: methanol in a mass ratio of 1: 1), and stirred at 25 ° C. for 20 minutes, followed by Coulter Multisizer III (Beckman Coal). Average particle diameter based on the volume measurement measured using a micrometer, a measurement range of 1 µm to 10 µm, and simultaneous passage correction.

On the other hand, Db was added 1 part of the substrate particles to 4000 parts of 1 mass% Hythenol® N-08 (Daiichi Kogyo Pharmaceutical Co., Ltd.) aqueous solution, sonicated for 10 minutes to disperse the substrate particles in the aqueous solution, and then After confirming that there were no coagulated particles by 500 times magnification with a Hiscope (KH-2700, HiROX Co., Ltd.), the volume standard measured using Coulter Multisizer Type III (measurement range 1 μm to 10 μm, with simultaneous passage correction) was used. The average diameter was called Db (average primary particle diameter). That is, the oil approximates the state in which the substrate particles are dispersed in the primary particles.

The shape of the substrate particle which can be used for this invention is not specifically limited. For example, it may be a spherical shape, a spheroidal shape, a confeti shape, a thin plate shape, a needle shape, or a cocoon shape, and the shape of the particle surface may be any of a smooth shape, a pleat shape, and a porous shape. Especially, when used as electroconductive fine particles, spherical shape is preferable at the point which forms favorable surface contact state, when particle | grains deform | transform between electrodes.

The size of the substrate particle is 1 mm (1000 µm) or less in terms of the mass average particle diameter. It is because the use of the substrate particle | grains larger than 1 mm when processed with electroconductive particle is limited, and there are few industrial fields of use. As for a mass average particle diameter, 0.1 micrometer-1000 micrometers are preferable, More preferably, they are 0.5 micrometer-500 micrometers, More preferably, they are 1 micrometer-100 micrometers. When the mass average particle diameter of a substrate particle is too small, when coating a conductive metal layer, such as electroless plating, particle | grains tend to aggregate and it may be difficult to form a uniform conductive metal layer. In addition, a mass mean particle diameter means the value computed by volume average particle diameter in the conventionally well-known particle size distribution measuring method, and the precision particle size distribution measuring apparatus using the Coulter principle specifically (for example, a brand name "Coulter Multisizer III type"). , Beckman Coulter, Inc.).

The coefficient of variation (CV value) in the particle size of the substrate particles which can be used in the present invention is preferably 15% or less, more preferably 10% or less, and even more preferably 8% or less. This is because the smaller the CV value, the smaller the particle size distribution. In addition, CV value is a value computed by applying the average particle diameter of the substrate particle and the standard deviation of the particle diameter of a substrate particle measured by the precision particle size distribution measuring apparatus using a Coulter principle to a following formula.

Coefficient of variation of particle size of substrate particles (%) = 100 × standard deviation / average particle size of particle size

The preferable range of the mass mean particle diameter and the coefficient of variation of the vinyl polymer microparticles before hydrophilization treatment mentioned later is also the same range as the substrate particle.

As described later, the substrate particles are preferably obtained by hydrophilizing the vinyl polymer fine particles. It is preferable that the dispersibility, mechanical properties, color, and particle size distribution characteristics (CV value) of the substrate particles and the vinyl polymer microparticles are about the same, and do not change before and after the hydrophilization treatment. In addition, dispersibility is a property which particle | grains do not adhere or fuse.

Mechanical properties can be evaluated by, for example, compressive modulus, compressive fracture load, recovery rate, and the like. The compressive modulus of the present invention is the modulus of elasticity (N / mm 2: MPa) when deformed by 10% by applying a load to the particles, the compressive fracture load is the load (mN) when the compressive strength is reached and the fracture is reached, and the recovery rate is compression. % Recovery after. In any of the substrate particles, the vinyl polymer fine particles and the conductive fine particles, the compressive modulus is preferably 1000 N / mm 2 or more, more preferably 2000 N / mm 2 or more, and even more preferably 3000 N / mm 2 or more. Similarly, the compressive breaking load is preferably 1 mN or more, more preferably 3 mN or more, and even more preferably 5 mN or more. In addition, the recovery rate is preferably 0.5% or more, more preferably 1% or more, and even more preferably 5% or more.

As a measuring method of the said mechanical characteristic, the following method is mentioned, for example.

[10% compressive modulus (10% K value: hardness)]

Circular flat plate having a diameter of 50 µm for one sample particle sprayed on a sample stage (material: SKS flat plate) at room temperature (25 ° C) by a micro compression tester (Shimazu Corporation, "MCTW-500"). Load and displacement (mm) when indenter (material: diamond) is used, load is applied at a constant load speed (2.275mN / sec) in the direction of the particle's center, and the particles are deformed until the compression displacement becomes 10% of the particle diameter. Measure The value is calculated by substituting the measured compressive load, the compressive displacement of the particles, and the radius of the particles into the following equation. This operation is performed with respect to three other particles, and makes the average value 10% compressive elastic modulus of a substrate particle.

Wherein E is the compressive modulus (N / mm 2), F is the compressive load (N), S is the compression displacement (mm), and R is the radius of the particles (mm). This operation is performed on the other three particles, and the average value is 10% compressive modulus of the substrate particles.

[Compression failure load]

The load is applied to the particles in the same manner as the compressive elastic modulus, and the load (mN) when the particles are destroyed by deformation is referred to as the compression failure load.

Compression strain recovery rate (recovery rate)

A value obtained by measuring the relationship between the load value and the compression displacement when the load is reduced after compressing the sample particles to a reverse load of 9.8 mN using a micro compression tester (Shimazu Corporation: "MCTW-500"). When the end point at the time of removing the load was set to the origin load value of 0.098 mN, and the compression (recovery) speed at the load and the load removal was measured at 1.486 mN / sec, the displacement L1 to the point of inversion and It is a value shown as ratio (L1 / L2) (%) of the displacement L2 from the point of inversion to the point which takes the origin load value.

The vinyl polymer fine particles as the raw material of the substrate particles according to the present invention are not particularly limited as long as the particles contain a vinyl polymer, and are organic inorganic composite particles composed of particles composed of vinyl polymers only or organic and inorganic materials. Any of can be used. Moreover, (meth) acryloyl is also contained in the word "vinyl" used by this invention. Specifically as vinyl polymer microparticles | fine-particles, the particle | grains which consist only of vinyl polymers, such as a (meth) acrylic-type (co) polymer and a (meth) acrylic- styrene type copolymer, and polymerizable (vinyl-group-containing meaning; the same below) alkoxy Organic inorganic composite particles, such as a silane radical polymer and / or a condensation copolymer, and a copolymer of a polymerizable alkoxysilane and a vinyl monomer, are mentioned. When referring to "vinyl polymer" in the following description, it means the polymer only of the organic material to which the vinylic monomer superposed | polymerized. In addition, the "vinyl-type polymer microparticles | fine-particles" said by this invention means the particle | grains containing the component and frame which consist of a "vinyl polymer." Although details of the production method of these vinyl polymer fine particles will be described later, emulsion polymerization, suspension polymerization, seed polymerization, sol-gel method and the like can be employed, and among them, seed polymerization and sol-gel method can reduce the particle size distribution. desirable. Moreover, the composition of microparticles | fine-particles can be confirmed by GC-MS etc.

[Vinyl Polymer Particles]

Vinyl polymer particle is obtained by superposing | polymerizing the monomer composition containing the monomer mixture containing a vinylic monomer. As the vinyl monomer to be contained in the monomer mixture, any of the non-crosslinkable monomer having one vinyl group in one molecule and the crosslinkable monomer having two or more vinyl groups in one molecule can be used.

As said non-crosslinkable monomer, it is (meth) acrylic acid, for example; Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylic Latex, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, glycidyl (meth) acrylate, cyclohexyl ( (Meth) acrylates, such as meta) acrylate, stearyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate; (Meth) acrylic-type monomers, such as hydroxyalkyl (meth) acrylates, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate : Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ethylvinylbenzene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, Styrene-based monomers, such as m-chloro styrene, p-chloro styrene, and parahydroxy styrene: Hydroxyl-containing vinyl ethers, such as 2-hydroxyethyl vinyl ether and 4-hydroxybutyl vinyl ether: 2-hydroxyethyl allyl ether And hydroxyl-containing allyl ethers such as 4-hydroxybutyl allyl ether. Moreover, when using (meth) acrylic acid as said non-crosslinkable monomer, it can partially neutralize with an alkali metal. Said non-crosslinkable monomer may be used independently and may use 2 or more types together. Among these non-crosslinkable monomers, monomers which do not have an ester bond in the molecule are preferably used as essential components, and among these, styrene-based monomers are preferable, and styrene, α-methylstyrene, ethylvinylbenzene and the like are particularly preferable. .

As a crosslinkable monomer, for example, trimethylol propane triacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, decaethylene glycol dimethacrylate, pentadecaethylene glycol Multifunctional (meth) such as dimethacrylate, pentaconta hexethylene glycol dimethacrylate, 1,3-butylene dimethacrylate, allyl methacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, etc. Acrylates; 1,4-butanedioldi (meth) acrylate, 1,6-hexanedioldi (meth) acrylate, 1,9-nonanedioldi (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol Polyalkylene glycol di (meth) acrylates, such as di (meth) acrylate and polytetramethylene glycol di (meth) acrylate; Aromatic divinyl compounds such as divinylbenzene, divinyl naphthalene, and derivatives thereof; Crosslinking agents such as N, N-divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfonic acid; Polybutadiene, polyisoprene unsaturated polyester, etc. are mentioned. These crosslinkable monomers may be used independently and may use 2 or more types together. Among these, it is preferable to use the monomer which does not have an ester bond in a molecule as an essential component, Especially, an aromatic divinyl compound is preferable and divinylbenzene is especially preferable.

It is preferable that the usage-amount of a styrene-type monomer and / or an aromatic divinyl compound is 1 mass% or more with respect to 100 mass% of all vinyl monomer mixtures, More preferably, it is 10 mass% or more, More preferably, it is 30 mass% or more. . When an aromatic divinyl compound is used as a styrene type monomer and a crosslinkable monomer as a non-crosslinkable monomer, since the plating property to a base particle becomes favorable, it is preferable.

Moreover, it is preferable to make content rate of the crosslinkable monomer in the said monomer mixture into 1 mass% or more, More preferably, it is 5 mass% or more, More preferably, it is 10 mass% or more. By setting the content rate of the crosslinkable monomer in the said monomer mixture to 1 mass% or more, the solvent resistance and heat resistance of vinyl polymer particle become high, and a mechanical characteristic can be controlled suitably. Moreover, in the organic-inorganic composite particle | grains mentioned later, for example, when using the silicone compound (alkoxysilane) which has a (meth) acryloyl group as a raw material, since this compound also acts as a crosslinking agent in particle | grains, about these compounds, Considered as a crosslinkable monomer.

Moreover, when superposing | polymerizing a monomer composition, a polymerization initiator and a dispersion stabilizer can be used as needed. As the polymerization initiator, any of those that can be used for polymerization can usually be used. For example, a peroxide initiator, an azo initiator, etc. can be used. Examples of the peroxide initiator include hydrogen peroxide, peracetic acid, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, benzoyl peroxide ortho benzoyl peroxide, orthomethoxy benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, and t-butylperoxide. Oxy-2-ethylhexanoate, di-t-butylperoxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, methylethylketone peroxide, diisopropylperox A dicarbonate, cumene hydroperoxide, cyclohexanone peroxide, t-butyl hydroperoxide, diisopropyl benzene hydroperoxide, etc. are mentioned.

Examples of azo initiators include dimethyl 2,2-azobisisobutyronitrile, azobiscyclohexacarbonitrile, 2,2'-azobisisobutyronitrile and 2,2'-azobis (2,4-dimethylvalero Nitrile), 2,2'-azobis (2,3-dimethyl butyronitrile), 2,2'-azobis (2-methyl butyronitrile), 2,2'-azobis (2,3,3 -Trimethylbutyronitrile), 2,2'-azobis (2-isopropylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (4 -Methoxy-2,4-dimethylvaleronitrile), 2- (carbamoyl azo) isobutyronitrile, 2,2'-azobis (2-amidinopropane) -dihydrochloride, 4,4 ' -Azobis (4-cyanopentanoic acid), 4,4'- azobis (4-cyano valeric acid), dimethyl-2,2'- azobisisobutyrate, etc. are mentioned.

These polymerization initiators may be individual or may use 2 or more types together. Moreover, it is preferable that the addition amount of these polymerization initiators shall be 0.1 mass part or more with respect to 100 mass parts of monomer mixtures, More preferably, it is 1 mass part or more, It is preferable to set it as 5 mass parts or less, More preferably, It is 3 mass parts or less.

A dispersion stabilizer is used in order to stabilize the droplet diameter of a monomer composition at the time of a polymerization reaction, when polymerizing a monomer composition using suspension polymerization method or the like. In addition, the dispersion stabilizer can be dissolved or dispersed in a solvent (for example, an aqueous solvent) that is a dispersion medium without being contained in the monomer composition. As the dispersion stabilizer, any of anionic surfactants, nonionic surfactants, cationic surfactants and amphoteric surfactants can be used. A dispersion stabilizer may be used independently and may use 2 or more types together. Among these, fatty acid oils such as sodium oleate and castor oil potassium; Alkyl sulfate ester salts such as sodium lauryl sulfate and lauryl ammonium sulfate; Polyoxyethylene distyryl phenyl ether sulfate ester salts such as polyoxyethylene distyryl phenyl ether sulfate ammonium salt and polyoxyethylene distyryl phenyl ether sulfate ester sodium salt; Alkyl benzene sulfonates such as sodium dodecyl benzene sulfonate; Anionic surfactants such as alkyl naphthalene sulfonates, alkanesulfonates, dialkyl sulfosuccinates, alkyl phosphate ester salts, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkylphenyl ether sulfate ester salts and polyoxyethylene alkyl sulfate ester salts Is preferred.

A dispersion stabilizer can adjust the addition amount suitably according to the size of desired vinyl polymer particle. For example, when vinyl polymer microparticles | fine-particles of 3 micrometers-30 micrometers of average particle diameters are desired, it is preferable to make the addition amount of a dispersion stabilizer into 0.1 mass part or more with respect to 100 mass parts of monomer mixtures, More preferably, it is 0.5 It is more than a mass part, More preferably, it is 1 mass part or more, It is preferable to set it as 10 mass parts or less, More preferably, it is 5 mass parts or less, More preferably, it is 3 mass parts or less.

Moreover, a pigment, a plasticizer, a polymerization stabilizer, a fluorescent brightener, a magnetic component, a ultraviolet absorber, an antistatic agent, a flame retardant, etc. can be added to a monomer composition. It is preferable that the usage-amount of these additives shall be 0.01 mass part or more with respect to 100 mass parts of monomer mixtures, More preferably, it is 0.1 mass part or more, More preferably, it is 0.5 mass part or more, It is preferable that it is 10 mass parts or less, More preferably, it is 5 mass parts or less, More preferably, it is 3 mass parts or less.

[Production Method of Vinyl Polymer Particles]

The method for producing vinyl polymer particles is to polymerize a monomer composition comprising a monomer mixture as described above. Moreover, as a polymerization method, well-known polymerization methods, such as suspension polymerization, seed polymerization, and emulsion polymerization, can be employ | adopted, Among these, suspension polymerization and seed polymerization are preferable.

In the case of employing the suspension polymerization method, any solvent that can be used is not particularly limited as long as the monomer composition is not completely dissolved. Preferably, an aqueous medium can be used. These solvents can be used suitably within the range of 20 mass parts or more and 10000 mass parts or less with respect to 100 mass parts of monomer compositions normally. As a manufacturing method of a vinyl polymer particle, the method of superposing | polymerizing by suspending the monomer composition containing a monomer mixture and a polymerization initiator in the aqueous solvent which melt | dissolved or disperse | distributed the dispersion stabilizer was polymerized.

It is preferable that the polymerization temperature of suspension polymerization shall be 50 degreeC or more, More preferably, it is 55 degreeC or more, More preferably, it is 60 degreeC or more, It is preferable to set it as 95 degrees C or less, More preferably, it is 90 degrees C or less, More Preferably it is 85 degrees C or less. The polymerization reaction time is preferably 1 hour or more, more preferably 2 hours or more, more preferably 3 hours or more, preferably 10 hours or less, more preferably 8 hours or less, and even more preferably. It is less than five hours. Moreover, in order to control the particle diameter of the vinyl polymer to produce | generate, it is preferable to perform reaction in the polymerization reaction after regulating the droplet diameter of a monomer composition or regulating the droplet diameter. The droplet diameter of this monomer composition is regulated by, for example, a suspension prepared by dispersing the monomer composition in an aqueous medium. It can carry out by stirring with a high speed stirrer, such as a homomixer and a line mixer, and the vinyl polymer microparticles | fine-particles produced | generated by the polymerization reaction can be applied to a process, such as drying and classification as needed. Moreover, it is preferable to perform drying at 150 degrees C or less, More preferably, it is 120 degrees C or less, More preferably, it is 100 degrees C or less.

In the case of employing the seed polymerization method, it is preferable to use a styrene-based or (meth) acrylate-based polymer as the seed particles, and more preferably non-crosslinked or small particles having a low degree of crosslinking. In addition, the average particle diameter of the seed particles is preferably 0.1 µm to 10 µm, and the value (CV value) expressed by 100 × particle diameter standard deviation / average particle diameter is preferably 10 or less. As a method for producing such seed particles, a method that can be used conventionally may be employed, and examples thereof include an unsaturated emulsion polymerization and a dispersion polymerization.

It is preferable that the input and the quantity of the monomer composition in seed polymerization are 0.5 mass part-50 mass parts with respect to 1 mass part of seed particle | grains. If the amount of the monomer composition is too small, the increase in the particle size due to polymerization is small. If the amount of the monomer composition is too large, the monomer composition may not be completely absorbed by the seed particles, and may be polymerized independently in the medium to produce abnormal particles. In addition, the conditions similar to the suspension polymerization can be applied to the polymerization temperature and the drying conditions of the obtained particles.

[Organic Inorganic Composite Particles]

An organic inorganic composite particle is particle | grains which consist of the organic part derived from a vinyl polymer, and an inorganic part. Examples of the organic-inorganic composite particles include forms in which inorganic fine particles such as metal oxides such as silica, alumina and titania, metal nitrides, metal sulfides and metal carbides are dispersed and contained in the vinyl polymer; A form in which metal siloxane chains (molecular chains containing “metal-oxygen-metal” bonds) and organic molecules such as (organo) polysiloxane and polytitaoxane are combined at the molecular level; The organoalkoxysilane having a vinyl group capable of forming a vinyl polymer such as vinyltrimethoxysilane causes a hydrolysis condensation reaction or a polymerization reaction of a vinyl group to obtain a silane compound having particles or hydrolyzable silyl groups obtained. The form which consists of organic inorganic composite particle containing a vinyl polymer backbone and a polysiloxane backbone like the particle | grains obtained by making it react with the polysiloxane made into polymerizable monomer etc. which have a vinyl group, etc. are mentioned. Among these, the form which consists of organic inorganic composite grain | particles especially containing a vinyl polymer skeleton and a polysiloxane skeleton is preferable.

Hereinafter, the organic-inorganic composite particles (hereinafter, simply referred to as "composite particles") containing the vinyl polymer skeleton and the polysiloxane skeleton will be described in detail.

The said vinyl polymer backbone is a vinyl polymer which has a principal chain comprised by the repeating unit of following formula (1), may have a side chain, has a branched structure, and may have a crosslinked structure. The hardness of the composite particles can be appropriately controlled.

Moreover, the polysiloxane skeleton is defined as the part which the siloxane unit of following formula (2) chemically couple | bonded continuously, and comprised the network of network structure.

The amount of SiO ₂ constituting the polysiloxane skeleton is preferably 0.1% by mass or more, more preferably 1% by mass or more, preferably 25% by mass or less, and more preferably 10% by mass or less with respect to the mass of the composite particles. . If the amount of SiO _{2 in} the polysiloxane skeleton is in the above range, the hardness of the composite particles can be easily controlled. The amount of SiO ₂ constituting the polysiloxane skeleton is the mass percentage required by measuring the mass before and after the particles are calcined at a temperature of 800 ° C. or higher in an oxidizing atmosphere such as air.

The composite particles can be arbitrarily adjusted by appropriately changing the ratio of the polysiloxane skeleton portion and the vinyl polymer skeleton portion with respect to each of mechanical properties such as hardness and fracture strength. It is preferable that the polysiloxane frame | skeleton in a composite particle is obtained by making hydrolysis condensation reaction of the silane compound which has a hydrolysable group.

Although it does not specifically limit as a silane compound which has hydrolyzability, For example, the silane compound of following General formula (3), its derivative (s), etc. are mentioned.

Wherein R 'may have a substituent and represents at least one group selected from the group consisting of alkyl, aryl, aralkyl and unsaturated aliphatic groups, X is selected from the group consisting of hydroxyl, alkoxy and acyloxy groups At least one group is represented, and m is an integer of 0 to 3.

Although it does not specifically limit as a silane compound of General formula (3), For example, tetrafunctional silane, such as tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, as m = 0. ; As m = 1, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, phenyltrimethoxysilane and benzyl tree Methoxysilane, naphthyltrimethoxysilane, methyltriacetoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, Trifunctional silanes such as 3- (meth) acrylooxypropyltrimethoxysilane and 3,3,3-trifluoropropyltrimethoxysilane; Examples of m = 2 include bifunctional silanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, diacetoxydimethylsilane and diphenylsilanediol; Examples of m = 3 include monofunctional silanes such as trimethylmethoxysilane, trimethylethoxysilane, and trimethylsilanol.

The derivative of the silane compound of the formula (3) is not particularly limited, but for example, a part of X is a compound substituted with a group capable of forming a chelating compound such as a carboxyl group, β-dicarbonyl group, or the silane compound. And low condensates obtained by partial hydrolysis.

Even if only 1 type is used, the silane compound which has hydrolyzability can be used combining 2 or more types suitably. In the general formula (3), when only the silane compound having m = 3 and its derivatives are used as raw materials, the composite particles are not obtained.

In the case where the polysiloxane skeleton of the composite particle has an organic silicon atom in which a silicon atom is directly bonded to at least one carbon atom in the vinyl polymer skeleton in a molecule, the silane compound having a hydrolyzable compound having an organic group containing a vinyl bond Need to use

As an organic group containing a vinyl bond, the organic group of following formula (4), (5), and (6) etc. are mentioned, for example.

In the above formula, R ^a represents a hydrogen atom or a methyl group, and R ^b represents a divalent organic group having 1 to 20 carbon atoms which may have a substituent.

In the formula, R ^c represents a hydrogen atom or a methyl group.

In the above formula, R ^d represents a hydrogen atom or a methyl group, and R ^e represents a divalent organic group having 1 to 20 carbon atoms which may have a substituent.

As an organic group of General formula (4), a (meth) acryloxy group etc. are mentioned, for example, As a silane compound of General formula (3) which has a (meth) acryloxy group, it is a gamma-methacryloxypropyl tree, for example. Methoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acrylooxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxypropyltriacetoxysilane, γ- Methacryloxyethoxypropyltrimethoxysilane (or it is also called (gamma) -trimethoxysilylpropyl- (beta)-methacryloxyethyl ether), (gamma)-methacryloxypropyl methyldimethoxysilane, and (gamma)-methacryloxypropyl) Methyl diethoxysilane, (gamma) -acrylooxypropyl methyldimethoxysilane, etc. are mentioned. These may use only 1 type or may use 2 or more types together.

As an organic group of the said General formula (5), a vinyl group, an isopropenyl group, etc. are mentioned, for example. As a silane compound of the said General formula (3) which has these organic groups, it is vinyl trimethoxysilane, vinyl, for example. Triethoxysilane, vinyltriacetoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinylmethyldiacetoxysilane and the like. These may use only 1 type or may use 2 or more types together.

As an organic group of the said General formula (6), a 1-alkenyl group or a vinylphenyl group, an iso alkenyl group, or isopropenyl phenyl group etc. are mentioned, for example, As a silane compound of the said General formula (3) which has these organic groups, it is an example. For example, 1-hexenyltrimethoxysilane, 1-hexenyltriethoxysilane, 1-octenyltrimethoxysilane, 1-decenyltrimethoxysilane, γ-trimethoxysilylpropyl vinyl ether, ω -Trimethoxy silyl undecanoic acid vinyl ester, p-trimethoxy silyl styrene, 1-hexenylmethyldimethoxysilane, 1-hexenylmethyl diethoxysilane, etc. are mentioned. These may use only 1 type or may use 2 or more types together.

The vinyl polymer backbone contained in the composite particles can be obtained by absorbing a vinyl monomer component into particles having a polysiloxane backbone obtained by the hydrolysis condensation reaction of the (I) silane compound, followed by polymerization. Moreover, especially when the said silane compound has an organic group containing a vinyl bond with a hydrolysable group, it can also be obtained by superposing | polymerizing this after the hydrolysis condensation reaction of (II) silane compound.

The multiparticulates may be in a form (chemical bond type) in which (i) the polysiloxane skeleton has an organosilicon atom in which a silicon atom is directly chemically bonded to at least one carbon atom in the vinyl-based polymer skeleton, and (ii) such organic It may be a form (IPN type) having no silicon atom in the molecule, and is not particularly limited, but the form of (i) is preferable. In the case of obtaining a vinyl polymer skeleton together with the polysiloxane skeleton in the method of (I), a multiparticulate having the form of (ii) is obtained, and in particular, the silane compound contains a vinyl bond together with a hydrolyzable group. If it has a group, the multiparticulate which combines the form of said (i) and (ii) is obtained. In addition, when the vinyl polymer skeleton is obtained together with the polysiloxane skeleton as in the above (II), a multiparticulate having the form of (i) is obtained.

In the method of said (I) or (II), the above-mentioned vinyl-type monomer is mentioned as a monomer which can be absorbed by the particle | grains which have a polysiloxane skeleton, It can select suitably according to the physical property of desired composite particle | grains. These may use only 1 type or may use 2 or more types together.

For example, hydrophobic vinyl-based monomers are preferable because they can produce a stable emulsion in which the monomer component is emulsified and dispersed when the monomer component is absorbed into the particles having a polysiloxane skeleton. In addition, by using the above-mentioned crosslinkable monomer, it is possible to easily control the mechanical properties of the obtained composite particles and to improve the solvent resistance of the composite particles. As a crosslinkable monomer, what was illustrated as what can be used for the said vinyl polymer particle can be used. As in the case of the vinyl polymer particles, an aromatic divinyl compound is preferable, and divinylbenzene is particularly preferable. Moreover, you may use the non-crosslinkable monomer illustrated about the said vinyl polymer particle as a monomer absorbed into the particle which has a polysiloxane skeleton. Especially, a styrene monomer is preferable, and styrene, (alpha) -methylstyrene, ethylvinylbenzene, etc. are especially preferable.

It is preferable that the manufacturing method of a composite particle includes a hydrolysis condensation process and a superposition | polymerization process, and it is more preferable to include the absorption process which absorbs a polymerizable monomer after a hydrolysis and condensation process and before a polymerization process. By including an absorption step, the content of the vinyl polymer skeleton component in the composite particles and the refractive index of the contained vinyl polymer skeleton can be adjusted. Moreover, when the silane compound used for a hydrolysis-condensation process does not have the element which comprises a vinyl polymer skeleton together with the element which can comprise a polysiloxane skeleton structure, the said absorption process is essential, and this absorption process is essential for this absorption process. In the subsequent polymerization step, a vinyl polymer backbone is formed.

The said hydrolysis condensation process is a process of carrying out the reaction which hydrolyzes and condenses a silane compound in the solvent containing water. By the hydrolysis condensation step, particles (polysiloxane particles) having a polysiloxane skeleton can be obtained. Hydrolysis and axial synthesis can employ | adopt arbitrary methods, such as batch, division | segmentation, and continuous. When hydrolysis and condensation are carried out, basic catalysts such as ammonia, urea, ethanolamine, tetramethylammonium hydroxide, alkali metal hydroxides and alkaline earth metal hydroxides can be preferably used as catalysts.

The solvent containing water may contain an organic solvent in addition to water or a catalyst. As an organic solvent, For example, Alcohol, such as methanol, ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, pentanol, ethylene glycol, propylene glycol, 1, 4- butanediol; Ketones such as acetone and methyl ethyl ketone; Esters such as ethyl acetate; (Cyclo) paraffins such as isooctane and cyclohexane; Aromatic hydrocarbons, such as benzene and toluene, are mentioned. These may be used independently or may use 2 or more types together.

In the hydrolysis-condensation step, anionic, cationic or nonionic surfactants and polymer dispersants such as polyvinyl alcohol and polyvinylpyrrolidone may also be used in combination. These may be used independently or may use 2 or more types together.

Hydrolysis condensation is a mixture of the silane compound as a raw material and a solvent containing a catalyst, water, and an organic solvent, and then at a temperature of 0 ° C. to 100 ° C., preferably at 0 ° C. to 70 ° C., for 30 minutes or more. It can carry out by stirring for time or less. This yields polysiloxane particles. Further, after the hydrolysis condensation reaction is carried out to a desired degree to produce particles, the seed particles can be grown by further adding a silane compound to the reaction system as a seed particle.

The absorption step is not particularly limited as long as it proceeds in the presence of the monomer component in the presence of the polysiloxane particles. Therefore, a monomer component can be added in the solvent which disperse | distributed polysiloxane particle | grains, and polysiloxane particle | grains may be added to the solvent containing a monomer component. Especially, it is preferable to add a monomer component in the solvent which disperse | distributed polysiloxane particle previously like the former. In particular, the method of adding a monomer component to the reaction solution without removing the polysiloxane particles obtained in the hydrolysis and condensation step from the reaction solution (polysiloxane particle dispersion) is preferable because the process is not complicated and the productivity is excellent.

In the absorption step, the monomer component is absorbed in the structure of the polysiloxane particles, but the concentration of each of the polysiloxane particles and the monomer component, the mixing ratio of the polysiloxane and the monomer component, the processing method, the method of mixing, and the like so that the absorption of the monomer component proceeds as soon as possible. It is preferable to set the temperature and time at the time of mixing, the processing method, means, etc. after mixing suitably, and to carry out on the conditions.

These conditions can consider the necessity suitably according to the kind of polysiloxane particle | grains and monomer components used, etc. Moreover, these conditions may apply only 1 type, or may apply and it may apply in combination of 2 or more type.

It is preferable to make the addition amount of the monomer component in the said absorption process into 0.01 times or more and 100 times or less with respect to the mass of the silane compound used as a raw material of a polysiloxane particle. More preferably, they are 0.1 times or more and 50 times or less, More preferably, they are 0.3 times or more and 30 times or less. When the addition amount does not reach the above range, the absorption amount of the monomer component of the polysiloxane particles decreases, and the mechanical properties of the resultant composite particles may be insufficient. When the addition amount exceeds the above range, the added monomer component is added to the polysiloxane particles. It tends to be difficult to completely absorb it, and there is a fear that aggregation between particles is likely to occur in a later polymerization step because unabsorbed monomer components remain.

In the said absorption process, the timing of addition of a monomer component is not specifically limited, It can add in batch, can add in several times, and can supply at arbitrary speed. In addition, when adding a monomer component, only a monomer component may be added and the solution of a monomer component may be added, However, it is polysiloxane particle which mixes the emulsion liquid which emulsified and disperse | distributed the monomer component to water or an aqueous medium with emulsifier previously, to polysiloxane particle. It is preferable because the absorption of the furnace is made more efficient.

Although the said emulsifier is not specifically limited, For example, the anionic surfactant illustrated as the said dispersion stabilizer, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxy Nonionic surfactants such as sorbitan fatty acid esters, polyoxyethylene alkylamines, glycerin fatty acid esters, and oxyethylene-oxypropylene block polymers may stabilize the dispersion state of the polysiloxane particles and the composite particles after absorbing the polysiloxane particles and the monomer component. Since it may be sufficient, these emulsifiers may use only 1 type or may use 2 or more types together.

The usage-amount of an emulsifier is not specifically limited, Specifically, it is preferable to set it as 0.01 mass part or more with respect to 100 mass parts of total mass of the monomer component to emulsify, More preferably, it is 0.05 mass part or more, More preferably, It is 1 mass part or more, It is preferable to set it as 10 mass parts or less, More preferably, it is 8 mass parts or less, More preferably, it is 5 mass parts or less. When it is less than 0.01 mass part, a stable emulsion may not be obtained, and when it exceeds 10 mass parts, there exists a possibility that emulsion polymerization etc. may coexist as a side reaction. In order to obtain an emulsion, a monomer component can be made into the emulsion state in water using a homomixer, an ultrasonic homogenizer, etc. with an emulsifier.

Moreover, when emulsion-dispersing a monomer component with an emulsifier, it is preferable to use 0.3 times or more and 10 times or less water or a water-soluble organic solvent with respect to the mass of a monomer component. As said water-soluble organic solvent, Alcohol, such as methanol, ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, pentanol, ethylene glycol, propylene glycol, 1, 4- butanediol; Ketones such as acetone and methyl ethyl ketone; Ester, such as ethyl acetate, etc. are mentioned.

It is preferable to perform an absorption process, stirring, for 5 minutes or more and 720 minutes or less in the temperature range of 0 degreeC or more and 60 degrees C or less. These conditions can be set suitably according to the kind of polysiloxane particle | grains, monomer used, etc., These conditions can employ | adopt only 1 type or in combination of 2 or more types.

In the absorption step, the determination of whether the monomer component is absorbed into the polysiloxane particles is carried out by observing the particles under a microscope, for example, before adding the monomer component and after completion of the absorption step. It can be judged easily by confirming that this is increasing.

The polymerization step is a step of polymerizing the monomer component to obtain particles having a vinyl polymer skeleton. Specifically, in the case of using a silane compound having an organic group having a vinyl bond, it is a step of polymerizing the vinyl bond of the organic group to form a vinyl polymer skeleton. Although it is a process of polymerizing the vinyl bond which a monomer component absorbed and a polysiloxane skeleton has, and forming a vinyl (system) polymer skeleton, in either case, it becomes a process of forming a vinyl (system) polymer skeleton by either reaction. Can be.

The polymerization reaction can be carried out during the hydrolysis condensation step or the absorption step, and may be carried out after either or both steps, and is not particularly limited, but usually after the hydrolysis condensation step (when the absorption step is performed, of course, absorption). After the process).

Although the polymerization method is not specifically limited, For example, the method of using a radical polymerization initiator, the method of irradiating an ultraviolet-ray or a radiation, the method of adding heat, etc. are employable. Although it does not specifically limit as said radical polymerization initiator, For example, what is used for superposition | polymerization of the said vinyl polymer particle is mentioned. These radical polymerization initiators may be used independently or may use 2 or more types together.

It is preferable that the usage-amount of radical polymerization initiator shall be 0.001 mass part or more with respect to 100 mass parts of total mass of a monomer component, More preferably, it is 0.01 mass part or more, More preferably, it is 0.1 mass part or more, and is 20 mass parts or less It is preferable, More preferably, it is 10 mass parts or less, More preferably, it is 5 mass parts or less. When the usage-amount of a radical polymerization initiator is less than 0.001 mass part, the polymerization degree of a monomer component may not rise. There is no restriction | limiting in particular about the addition method to the solvent of a radical polymerization initiator, The method of carrying out whole quantity in the beginning (before reaction start) (a form which emulsifies-disperses a radical polymerization initiator with a monomer component, and after a monomer component is absorbed) Any method known in the art, such as a method in which a polymerization initiator is added), a part is initially added and the remaining feed is continuously added, or an intermittent pulse addition method, or a combination method thereof is employed. can do.

The reaction temperature at the time of performing radical polymerization is preferably 40 ° C or higher, more preferably 50 ° C or higher, preferably 100 ° C or lower, and more preferably 80 ° C or lower. If the reaction temperature is too low, the degree of polymerization does not increase sufficiently, and the mechanical properties of the composite particles tend to be insufficient. On the other hand, if the reaction temperature is too high, aggregation between particles tends to occur during polymerization. Moreover, although reaction time at the time of radical polymerization can be suitably changed with the kind of polymerization initiator to be used, 15 minutes-600 minutes are preferable normally, More preferably, they are 60 minutes-300 minutes. If the reaction time is too short, the degree of polymerization may not sufficiently increase. If the reaction time is too long, aggregation tends to occur between particles.

According to the above production method, vinyl polymer microparticles having the above-described desirable characteristics (mechanical characteristics, particle size distribution characteristics, etc.) are obtained.

The substrate particles according to the present invention are obtained by hydrophilizing the vinyl polymer fine particles obtained as described above. Below, the hydrophilization treatment of vinyl polymer microparticles | fine-particles is demonstrated.

[Hydrophilization Treatment of Vinyl Polymer Fine Particles]

Although the hydrophilization treatment method is not particularly limited, the surface of the vinyl polymer microparticles is made hydrophilic by contacting the vinyl polymer microparticles with a mixed gas comprising essentially a gas of a compound containing a fluorine gas and an oxygen atom. The treatment method is preferred. Hereinafter, this hydrophilization treatment method will be described. The hydrophilization treatment may be such that the vinyl polymer fine particles and the mixed gas are in contact with each other, and the method is not particularly limited, but the mixed gas is introduced into a container capable of holding the vinyl polymer fine particles and treated for a predetermined time in a sealed state ( Sealed contact method) or a method of continuously supplying the mixed gas in a container capable of holding the vinyl polymer fine particles (continuous supply method) is preferable.

At the time of treatment, it is preferable to increase the contact efficiency between the mixed gas and the substrate particles and to make the hydrophilic uniform in a short time. In order to increase the contact efficiency, it is preferable to diffuse the mixed gas into the processing vessel, and the mixed gas may be air-flow-stirred using a stirring device such as a fan, or a method of thinning vinyl polymer fine particles on a pallet or the like. Moreover, vinyl polymer microparticles | fine-particles can also be stirred, a method of rotating a process container using a drum rotary apparatus, etc., or the method of flowing vinyl polymer microparticles | fine-particles with a stirring apparatus, etc. are mentioned. These contact efficiency improvement means can be used in combination of plurality.

When the vinyl polymer particles are thinly deposited on a pallet or the like, it is preferable to load them so that the thickness of the vinyl polymer fine particles layer is 2 mm or less in the processing container in order to uniformly and hydrophilize the particles without variation between the particles. Do. The thickness of the more preferable particle layer is 0.5 mm or less.

The concentration of fluorine gas in the mixed gas is 0.01% by volume to 1.0% by volume. If the fluorine gas concentration is less than 0.01% by volume, there is a fear that particles having insufficient hydrophilization treatment may exist. It is preferable to make fluorine gas concentration 0.08 volume% or more from the point which is excellent in the uniformity of a hydrophilization treatment. When the fluorine gas concentration is too high, coloration may occur in the substrate particles, but when the fluorine gas concentration is 1.0 vol% or less, it is slightly white or colored. It is more preferable to set it as 0.3 volume% or less.

In mixed gas, the gas of the compound containing an oxygen atom is also an essential component with fluorine gas. As a gas of a compound containing an oxygen atom, oxygen, sulfur dioxide, carbon dioxide, carbon monoxide, nitrogen dioxide, etc. are mentioned as a preferable thing. Among these, an oxygen gas is preferable at the point that the hydrophilization effect is high also in mild process conditions. In addition to the gas of the compound containing fluorine gas and oxygen atom, inert gas, such as nitrogen, helium, argon, can also be used for mixed gas. Moreover, it is preferable to use nitrogen gas as an inert gas from a viewpoint of preventing dust explosion in the process in a gaseous phase, and industrially and safely performing a hydrophilization process. Therefore, the mixed gas preferably has a composition consisting of fluorine gas, a gas of a compound containing oxygen atoms, and an inert gas, and more preferably a mixed gas containing fluorine gas, oxygen gas, and nitrogen gas.

If the concentration of the gas of the compound containing the oxygen atom in the mixed gas is 0.1% by volume to 99.99% by volume, the substrate particles can be hydrophilized. If the gas concentration of the compound containing the oxygen atom is less than 0.1% by volume, there is a fear that particles having insufficient hydrophilization treatment may be present. In order to obtain particles (powder) having a uniform degree of hydrophilization, and to obtain highly hydrophilized particles in a short time, the gas concentration of the compound containing oxygen atoms is preferably 0.1 vol% or more, more preferably. 0.5 volume% or more. On the other hand, the high concentration of the gas of the compound containing oxygen atoms does not adversely affect the hydrophilization of the particles, but suppresses the occurrence of dust explosion in the hydrophilization treatment, and can safely perform the hydrophilization treatment 10 vol% or less is preferable from the reason for being present, More preferably, it is 5 vol% or less.

In the case of using an inert gas as a component of the mixed gas, the concentration of the inert gas is not particularly limited, and the concentration of the inert gas is suitably within a range that does not impair the effect of the hydrophilization treatment by the gas of the compound containing fluorine gas and oxygen atoms. You can choose. Usually, 99 volume% or less is preferable. When it exceeds 99 volume%, there exists a possibility that the particle with insufficient hydrophilization may exist. Moreover, it is preferable that the concentration of an inert gas is 90 volume% or more, and 94 mass% or more is more preferable for suppressing generation | occurrence | production of the dust explosion in a hydrophilization treatment, and performing hydrophilization treatment safely.

If the partial pressure of the fluorine gas in the mixed gas is 8 Pa (0.06 Torr) or more, the uniformity of the hydrophilization treatment is excellent and preferable. More preferably, it is 24 Pa (0.18 Torr) or more, More preferably, it is 64 Pa (0.48 Torr) or more. From the viewpoint of suppressing decomposition and coloring of the vinyl polymer skeleton by the hydrophilization treatment, the partial pressure of the fluorine gas is preferably 1000 Pa (7.5 Torr) or less, and more preferably 700 Pa (5.25 Torr) or less.

When the oxygen gas is used as a component of the mixed gas, the partial pressure of the oxygen gas is preferably 70 Pa (0.53 Torr) to 85000 Pa (637.6 Torr) from the viewpoint of uniformly performing the hydrophilization treatment. Further, from the viewpoint of industrially and safely performing a hydrophilization treatment, it is preferable to be 70 Pa to 7798 Pa (60 Torr), more preferably 70 Pa to 3999 Pa (30 Torr). The preferred range for the partial pressure of the gas of the compound containing the oxygen atom is also the same.

When using nitrogen gas as a component of the mixed gas, the partial pressure of nitrogen gas is preferably 3199 Pa (24 Torr) to 79180 Pa (594 Torr) from the viewpoint of industrially and safely performing hydrophilization treatment, more preferably 71918 Pa ( 540 Torr) to 79180 Pa (594 Torr). Also when using another inert gas, the preferable range of the partial pressure of another inert gas is the same.

The total pressure of the mixed gas is preferably 101.3 kPa (760 Torr) or less in order to safely perform the hydrophilization treatment. If it exceeds 101.3 kPa, the mixed gas may leak out of the container.

In the case of the sealed contact type, the ratio of the mixed gas to the vinyl polymer fine particles is preferably 30 L to 4000 L in terms of normal temperature and normal pressure for 1 kg of the vinyl polymer fine particles, and the feed ratio is preferably 1000 L to 3000 L. More preferred. In the case of the continuous feed type, it is preferable to supply so that the total flow rate may be 30 L to 15000 L in terms of normal temperature and normal pressure with respect to 1 kg of substrate particles, and it is preferable to supply so that it becomes 1000 L to 10000 L.

Specifically, in the case of the sealed contact type, the vinyl polymer fine particles put in the container are put in a sealable chamber, and the pressure is reduced, a mixed gas is introduced, and a predetermined time treatment is performed. If moisture remains, HF is generated and dangerous. Therefore, it is preferable to evacuate sufficiently under reduced pressure. In the case of continuous feeding, a mixed gas can be introduced for a predetermined time.

In the case of hermetic contact, the chamber can be preheated in advance before introducing the mixed gas. About -20 degreeC-about 200 degreeC are preferable, about 0 degreeC-about 100 degreeC are more preferable, and 10 degreeC-40 degreeC are still more preferable. If the reaction temperature exceeds 200 ° C, the vinyl polymer particles may be decomposed. If the temperature is lower than -20 ° C, the hydrophilization may be insufficient. In addition, reaction temperature means the temperature of the gas in a chamber.

At the time of introducing the mixed gas, a gas other than the gas of the compound containing oxygen atoms or other fluorine gas may be introduced into the chamber first, followed by the introduction of the fluorine gas, or a gas mixed in advance.

The contact time (treatment time) of the vinyl polymer fine particles and the mixed gas is not particularly limited and can be processed until the desired degree of hydrophilization is achieved, but the treatment is generally completed in about 10 to 60 minutes. After the treatment, the pressure is reduced to about 0.13 Pa (0.001 Torr) again, and thereafter, a step of introducing nitrogen gas is preferably performed. At the end of this process, open to atmospheric pressure.

In the hydrophilization treatment step of the vinyl polymer fine particles, it is preferable to carry out a treatment of contacting the particles after the mixed gas contact with water after the contact treatment with the gas. By contact with the mixed gas, -C (F) = O formed on the surface of the particles comes into contact with moisture, thereby more efficiently converting to a carboxyl group. At this time, HF generated or HF or F ₂ adsorbed on the particle surface can be effectively removed. It is preferable that the said moisture is alkaline aqueous solution, and / or water and / or water vapor.

As a form which makes particle and water contact after mixed gas contact, the form which uses alkaline aqueous solution as water; Forms using water and / or steam; It may be in any form using an alkaline aqueous solution and water and / or water vapor. Especially, the form using alkaline aqueous solution and water and / or water vapor is preferable. The order of contact is not particularly limited, but from the viewpoint of efficiently removing HF or F2 and the like adsorbed on the particle surface, it is preferable to contact the particles with an alkaline aqueous solution and then contact with water and / or water vapor. When contacted with an alkaline aqueous solution, an alkali metal salt or amine salt of carboxylic acid (hereinafter sometimes referred to as "carboxylate") is formed on the particle surface. This carboxylate is preferable because it further enhances the hydrophilicity of the particles. After that, the alkaline aqueous solution can be washed by contacting the particles with water and / or water vapor. In the present specification, the case where the particles and the alkaline aqueous solution are brought into contact with each other is referred to as alkali treatment, and the case where the particles and water are brought into contact with each other may be referred to as warm water washing.

Carboxyl or advances the conversion of carboxylic acid salts efficiently, and is not limited to effectively remove HF or F ₂ that is adsorbed to the particle surface, and special As the contact treatment with the water to reduce the eluting fluorine, For example, after the chamber used for contact with the gas is opened to atmospheric pressure, water vapor is sent into the chamber and the particles are brought into contact with water; A method of opening the chamber used for contact with the gas to atmospheric pressure, sending water vapor into the chamber, contacting the particles with water, and further removing the particles, dispersing them in water, and washing with water or a solvent containing water; A method of immersing the particles taken out of the chamber after contact with the gas in a separate steam atmosphere or washing with water or a solvent containing water; A method in which the particles taken out of the chamber are dispersed in an alkaline aqueous solution and then subjected to alkali treatment after contact with the gas; The particle | grains taken out from the chamber after contact with gas are disperse | distributed in alkaline aqueous solution, and the alkali treatment is carried out, and also the method of taking out a particle | grain, disperse | distributing in water, and wash | cleaning with water or a solvent containing water, etc. are mentioned. The contact time with moisture is preferably about 1 minute to 600 minutes.

In order to efficiently advance the conversion of -C (F) = O to a carboxyl group or carboxylate, and to effectively remove HF or F2 adsorbed on the surface of HF and particles produced at this time, water (alkaline aqueous solution, and And / or the temperature of water and / or water vapor) is preferably 20 ° C or higher, more preferably 40 ° C or higher, still more preferably 60 ° C or higher, and most preferably 80 ° C or higher.

Moreover, when treating particle | grains with the alkaline aqueous solution and / or the solvent containing water or water, it is preferable to make particle concentration into 0.5 mass%-50 mass% in 100 mass% of a total of a solvent and particle | grains. If the particle concentration is less than 0.5% by mass, the amount of fluorinated waste water generated when washing a predetermined amount of particles increases, which may increase the industrial cost. If the particle concentration exceeds 50% by mass, there is a fear that the washing will be insufficient. In order to perform the washing | cleaning of particle | grains efficiently, it is also preferable to perform ultrasonic dispersion in the state which put the particle | grains in the solvent.

As described above, the elutable fluorine such as the fluorine component adhering to the surface of the particle may cause problems such as corrosion due to the safety of the particle or contact with other materials, and therefore, it is reduced and removed as much as possible. It is preferable to carry out an alkali treatment using an alkaline aqueous solution as the water, and the eluted fluorine adsorbed on the particle surface can be more efficiently removed. In addition, since the carboxyl groups on the surface of the substrate particles are converted to carboxylates by alkali treatment, the hydrophilicity of the particles is increased, and the plating properties of the substrate particles are also improved.

As alkaline aqueous solution, aqueous solution of water-soluble amines, such as ammonia, monoethanolamine, and diethanolamine, alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, potassium hydroxide, a rhodium hydroxide, cesium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, potassium carbonate An aqueous solution containing alkali metal element ions in which alkali metal compounds such as alkali metal carbonates such as rubidium and cesium carbonate are dissolved in water is preferably used. Among the alkaline aqueous solutions, aqueous solutions containing alkali metal element ions are preferable, and further preferably have sodium ions, and particularly preferably aqueous sodium hydroxide solution.

It is preferable that the density | concentration of alkaline aqueous solution is 0.01N-5N. More preferably, they are 0.05N-2N, More preferably, they are 0.1N-1N. Although the specific method of alkali treatment is not specifically limited, For example, after contacting with a gas, the particle | grains taken out from the chamber are disperse | distributed to the alkaline aqueous solution of the said density | concentration, and a particle | grain is carried out for 1 minute-600 minutes at the temperature of 80 degreeC or more. The method of contacting with alkaline aqueous solution is mentioned.

The amount of fluorine atoms (total amount of fluorine) contained in the obtained substrate particles, the amount of fluorine atoms that are ionized and liberated (elutable fluorine content), and the non-elutable fluorine content can be measured by the following method.

[Total Fluorine Amount: Oxygen Combustion Flask Method]

2 mg of particles are weighed on a 3 cm × 2 cm filter paper and wrapped so that the particles do not scatter. The platinum basket attached to the oxygen flask is heated with a Bunsen burner and the glowing state is continued for about 5 seconds. When the basket cools, filter paper wrapped in particles is placed in the basket. 15 ml of distilled water is put into a 500 ml oxygen flask, and the inner wall of the flask is wetted to replace the flask with an oxygen atmosphere. Subsequently, the filter paper in the basket is ignited, and this is quickly inserted into the flask. After the combustion, the flask was shaken two or three times and left for 30 minutes, after which the contents of the flask were transferred to a 100-mL polypropylene beaker, and distilled water was further added to adjust the total amount to 50 ml. 5 ml of buffer was added, pH was adjusted uniformly, the fluorine ion concentration was measured by the ion meter, stirring with the magnetic stirrer, and the total amount of fluorine (mg / g) was computed. Here, the ion meter used "Orion 11150004-Star" (ThermoFisher Scientific) and the electrode "Orion 9609BNWP" (verb).

[Elutable Fluorine Content: Fluorine Ion Electrode Method]

50 mL of distilled water was injected into a 100 mL polypropylene beaker, and 5 mL of buffer solution was further added. While stirring this with a magnetic stirrer, the fluorine ion electrode was immersed in the liquid. 0.2 g of particles were added, and the concentration of fluorine ions for 360 minutes was measured after the addition, and the elution fluorine content (mg / g) was used. The ion meter and the electrode used the same thing as the case of the measurement of the total fluorine amount.

[Non-elutable fluorine content]

The non-elutable fluorine content (mg / g) was calculated by the following formula.

Non-elutable fluorine content = (total amount of fluorine)-(elutable fluorine content)

In addition, the value measured by the following method was used as an acid value of the substrate particle obtained by the said hydrophilization treatment.

[Measurement of Acid Value]

Ultrapure water (Organo Co., Ltd., formulated with "PURELITE" PRA-0015-000 type, 18.2 MΩ · cm or less) was added to a small amount of 0.5 g of substrate particles, and the total amount was adjusted to 50 g. Was carried out. Subsequently, a neutralizing titration was carried out by dropping a KOH aqueous solution (titration solution) having a concentration of 0.005M by using an automatic titrator (COM-1600, Hiranuma Industrial Co., Ltd.) to the dispersion of the substrate particles, and performing a neutralization titration. The addition amount of the titrant was calculated, and the acid value was calculated by the following formula.

[Confirmation of Carboxylic Acid and Carboxylate Generation]

The presence or absence of the formation of carboxyl groups and carboxylates on the surface of the particles after hydrophilization treatment is carried out by using an X-ray photoelectron analyzer (ESCA: Albacpie Co., Ltd., `` PHI QuanteraSXM (Scanning X-ray Microprobe) ''. It determined by the presence or absence of the peak of 288 eV.

<Method for producing conductive fine particles>

The method for producing conductive fine particles of the present invention has a feature of forming a conductive metal layer on the surface of the substrate particle. Preferably, the formation of the conductive metal layer is preferably performed by an electroless plating method. As described above, the adhesion between the substrate particles and the conductive metal layer is greatly influenced by the degree of hydrophilization based on the hydrophilic basis such as acidic functional groups on the surface of the substrate particles. Therefore, it is preferable that the substrate particles have a high degree of hydrophilicity on the surface, and the above-described treatment of bringing the vinyl polymer fine particles into contact with a mixed gas comprising essentially a gas of a compound containing fluorine gas and an oxygen atom (“hydrophilization” It is preferable that it is obtained by performing a process ").

Although the detailed reason why the adhesiveness of a substrate particle and a conductive metal layer improves by the said hydrophilization process is not clear, it is estimated as follows.

By contacting the vinyl polymer microparticles with a mixed gas comprising essentially a gas of a compound containing fluorine gas and an oxygen atom, hydrogen bonded to the carbon atoms constituting the vinyl polymer microparticles is replaced with oxygen and fluorine. , -C (F) = O, after which a part or all is converted into a carboxyl group. Accordingly, a large number of —C (F) ═O and / or carboxyl groups are present in the vicinity of the surface of the vinyl polymer microparticles, so that the hydrophilicity of the vinyl polymer microparticles is significantly increased. At this time, the reaction of converting CH bonds in some particle skeletons into CF bonds also occurs with the formation of -C (F) = O or a carboxyl group. As a result, since an ionic bond, a hydrogen bond, a coordination bond, etc. are formed between these functional groups and a metal ion, it is thought that the adhesiveness of a base particle and an electroconductive metal layer improves.

In particular, in the case of forming the conductive metal layer by the electroless plating method described later, the chelate effect of palladium ions, which is a raw material of the plating catalyst by the functional group, becomes very high, so that the plating catalyst is immobilized on the surface of the substrate particle with high density and solidity. In addition, aggregation of the substrate particles during the electroless plating treatment is prevented by the influence of the hydrophilic groups remaining on the particle surface after the catalyzing treatment. For this reason, it is considered that the conductive metal layer is uniformly formed without causing defects (parts not plated) such as the bonding force between the obtained conductive metal layer and the surface of the substrate to increase and the substrate particles are exposed.

And also in the method of manufacturing the base particle which has a carboxyl group using the dispersing agent, such as a vinyl monomer which has a carboxy group, and polycarboxylic acid, although the carboxyl group exists in the surface of a base particle, adhesiveness between the base particle / conductive metal layer equivalent to this invention is carried out. You can't get it. That is, in the said method, since a carboxy group is introduce | transduced at the time of a polymerization reaction, a carboxy group cannot be introduce | transduced selectively on the surface of a polymer particle. Moreover, even in the polymerization system excellent in dispersion stability, generation | occurrence | production of aggregated particles is inevitable, and a difference arises in the amount of carboxyl groups introduced between individual polymer particles by this.

On the other hand, since the above preferred hydrophilization treatment is a gas phase reaction, since the gas spreads evenly over the entire surface of the fine particles by diffusion, a uniform and selective hydrophilization treatment is possible, resulting in high It is thought that adhesiveness is obtained. Therefore, cracks and peeling of the conductive metal layer are less likely to occur, and good conductivity can be maintained even when the crimping treatment is performed.

In general, in the case of producing electroconductive fine particles by employing a plating treatment, first, after performing degreasing treatment of the core material particles, an etching treatment for forming minute unevenness on the surface of the resin fine particles in order to improve adhesion of the plating layer is performed. Is done. However, in this invention, since the base particle with a high acid value is used, the adhesiveness of a base particle and a conductive metal layer can be improved. Therefore, the degreasing and etching processes which have been necessary in the past can be simplified, and a low cost process is realized. In addition, since no acidic substance containing heavy metals such as chromic acid which can be used in the etching treatment is used, a process can be provided that can greatly reduce the load on the environment.

The method of coating a conductive metal layer on the surface of a substrate particle is not specifically limited, For example, the method by plating, such as electroless plating and substitution plating; A method for coating a base particle with a paste obtained by mixing metal fine powder alone or in a binder; Physical vapor deposition methods, such as vacuum deposition, ion plating, and ion sputtering, are mentioned. Among these, the electroless plating method is preferable because it does not require a large-scale apparatus and can easily form a conductive metal layer. Hereinafter, the method of manufacturing the electroconductive fine particles of this invention by the electroless plating method is demonstrated.

That is, the recommended manufacturing method of the conductive fine particles of the present invention includes (i) a catalyzing step and (ii) an electroless plating step. Hereinafter, each process is explained in full detail.

[(i) Catalysis Process]

In the catalysis step, a catalyst layer serving as a starting point for the electroless plating performed in the next step is formed on the surface of the substrate particles hydrophilized in the hydrophilization treatment step. The method of forming a catalyst layer is not specifically limited, It can carry out using the catalyzing reagent marketed for electroless plating. For example, the substrate particles are immersed in a solution containing palladium chloride and tin chloride as a catalyzing reagent to adsorb palladium ions on the surface of the substrate particles, and then the above-mentioned solution is dissolved in an acidic solution such as sulfuric acid, hydrochloric acid or sodium hydroxide. Reducing palladium ions and depositing palladium on the surface of the substrate particle; And a method of depositing palladium on the surface of the substrate particles by dipping the substrate particles in a palladium sulfate solution, adsorbing palladium ions on the surface of the substrate particles, and then reducing the palladium ions with a solution containing a reducing agent such as dimethylamine borane. have.

Examples of the catalyzing reagent include palladium chloride, palladium nitrate, tin chloride, mixtures thereof, and the like. The catalyzing reagent is used after being dissolved in hydrochloric acid or the like. Dimethylamine borane, hypophosphorous acid, etc. are mentioned as said reducing agent.

[(ii) Electroless Plating Process]

Next, an electroless plating process is performed in which a conductive metal layer is formed on the surface of the substrate particle on which the catalyst layer is formed. In this step, the substrate particles in which the catalyst layer is formed are immersed in the plating solution in which the reducing agent and the desired metal salt are dissolved. The catalyst is used as a starting point, the metal ions in the plating solution are reduced with the reducing agent, and the desired metal is deposited on the surface of the substrate particles to form a conductive metal layer. To form.

First, the substrate particles subjected to catalysis are sufficiently dispersed in water to prepare an aqueous slurry of the substrate particles. Here, the substrate particles need to be sufficiently dispersed in the aqueous medium to be plated. This is because when the electroless plating is performed in a state in which the substrate particles are agglomerated, an untreated surface (surface where no conductive metal layer is present) occurs on the contact surfaces between the substrate particles, and in this case, stable conductive characteristics are not obtained.

In addition, since the substrate particles according to the present invention have a high density of hydrophilic functional groups introduced into the surface of the particles, the substrate particles themselves have a very high dispersibility in the plating solution, and are hard to cause aggregation of the substrate particles during the electroless plating treatment. . However, it is preferable to be careful enough so that aggregation of the substrate particles does not occur, and the substrate particles can be water-dispersed using a known dispersing means. As a conventionally known dispersing means, a shear dispersing device such as stirring, high speed stirring, or a colloid mill or homogenizer can be used. Ultrasonic waves may also be used in the dispersing operation, and dispersants such as surfactants may be added as necessary.

Subsequently, an aqueous slurry of base particles is added to an electroless plating solution containing a salt, a reducing agent, a complexing agent, and a main additive which can be used as necessary, for the desired conductive metal, and then subjected to electroless plating.

Examples of the conductive metal salts include chlorides, sulfates, acetates, and the like of the metals exemplified above as the conductive metal layer. For example, when it is desired to form a nickel layer as the conductive metal layer, nickel salts such as nickel chloride, nickel sulfate, and nickel acetate may be mentioned. The concentration of the conductive metal salt in the electroless plating solution can be appropriately determined according to the size (surface area) of the substrate particles so that a conductive metal layer having a desired film thickness is formed.

As the reducing agent, sodium hypophosphite, dimethylamine borane, sodium borohydride, potassium borohydride, hydrazine and the like can be used.

As a complexing agent, the compound which has a complexing effect with respect to the ion of the conductive metal to be used can be used. For example, compounds which have a complexing effect on nickel include citric acid, hydroxyacetic acid, tartaric acid, malic acid, lactic acid, gluconic acid or carboxylic acids such as alkali metal salts and ammonium salts, amino acids such as glycine, ethylenediamine and alkylamines. Amine acids, other ammonium, EDTA, a pyrroline wire (salt), etc. are mentioned. These may be used individually by 1 type and may be used in combination of 2 or more type.

The pH of the preferable electroless plating liquid in an electroless plating process is 4-14.

The electroless plating reaction is started quickly by adding the substrate particle slurry. This reaction is accompanied by the generation of hydrogen gas. Therefore, the electroless plating process is said to be completed with the time when hydrogen gas generation was not fully recognized. After completion | finish of reaction, the electroconductive fine particle in which the electroconductive metal layer was formed in the reaction system is taken out, and it wash | cleans and dries as needed.

Although the electroconductive fine particle of this invention is obtained as mentioned above, by repeating the said electroless-plating process process, you may coat | cover a heterogeneous metal with several layers on the surface of electroconductive fine particle. For example, electroconductive fine particles having a coating layer of gold in the outermost layer by subjecting the substrate particles to nickel plating (nickel coated particles) and then adding nickel coated particles to the electroless gold plating solution and performing gold substitution plating. Is obtained.

[(iii) other processes]

When the electroconductive fine particles of this invention have an insulating resin layer, after the said electroless plating process, the surface of an electroconductive metal layer is insulated by resin etc. by the surface.

It does not specifically limit as a method of forming an insulating resin layer, For example, in the presence of electroconductive fine particles after an electroless-plating process, interfacial polymerization, suspension polymerization, and emulsion polymerization of the raw material of an insulating resin layer are performed, A method of microencapsulating conductive fine particles; A dipping method of dispersing the conductive fine particles in the insulating resin solution in which the insulating resin is dissolved in an organic solvent, followed by drying; Any conventionally known method such as a spray dry method or a hybridization method can be used.

<Anisotropic Conductive Material>

The electroconductive fine particles of this invention are also preferable as a constituent material of an anisotropic conductive material, and the anisotropic conductive material which uses the electroconductive fine particles of this invention is also one of the preferable embodiment of this invention. If the anisotropic conductive material is formed using the conductive fine particles of the present invention, the form is not particularly limited, and examples thereof include various forms such as an anisotropic conductive film, an anisotropic conductive paste, an anisotropic conductive adhesive, and an anisotropic conductive ink. . That is, these anisotropic conductive materials can be electrically connected to each other by providing the substrates opposed to each other or between the electrode terminals.

After the said anisotropic conductive film adds a solvent to the film forming composition containing electroconductive fine particles of this invention, binder resin, etc., and makes it a solution form, after apply | coating this solution on the film made of polyethylene terephthalate, It can be obtained by evaporating the solvent. The obtained anisotropic conductive film is disposed on an electrode, for example, and is used for connection between electrodes by superposing an opposing electrode on the anisotropic conductive film and heating and compressing it.

The anisotropic conductive paste is obtained by, for example, making a resin composition containing the conductive fine particles of the present invention, a binder resin, and the like into a paste. The obtained anisotropic conductive paste is coated with a desired thickness on the electrode to be connected to, for example, a suitable dispenser, and the counter electrode is superimposed on the coated anisotropic conductive paste, heated and pressurized to cure the resin. This is used for the connection between the electrodes.

The said anisotropic electrically conductive adhesive agent is obtained by adjusting the resin composition containing the electroconductive fine particles of this invention, binder resin, etc. to desired viscosity, for example. The obtained anisotropic conductive adhesive is used for connection between electrodes by coating the electrode with a desired thickness in the same manner as the anisotropic conductive paste, and then superposing the opposite electrodes and bonding them together.

The anisotropic conductive ink is obtained by, for example, adding a solvent to a resin composition containing the conductive fine particles of the present invention, a binder resin and the like to adjust the viscosity to a viscosity suitable for printing. The obtained anisotropic conductive ink is used for connection between electrodes, for example, by screen printing onto an electrode to be bonded, evaporating the solvent, superposing the counter electrode on the printing surface by the anisotropic conductive ink, and heating and compressing the counter electrode. do.

The anisotropic conductive material is produced by dispersing the conductive fine particles of the present invention in an insulating binder resin to a desired form, but of course, the insulating binder resin and the conductive fine particles are respectively used to connect between substrates or between electrode terminals. It does not matter.

It does not specifically limit as said binder resin, For example, Thermoplastic resin, such as an acrylic resin, ethylene-vinyl acetate resin, a styrene- butadiene block copolymer; Curable resin composition hardened | cured by reaction with hardening | curing agents, such as a monomer, an oligomer, and isocyanate which have glycidyl group, curable resin composition hardened | cured by light or heat, etc. are mentioned.

Although the content rate of the said electroconductive fine particle in the anisotropic conductive material of this invention can be suitably determined according to a use, For example, the ratio of the electroconductive fine particle which occupies in an anisotropic conductive material is 2 volume%-70 volume%, and 5 is preferable. More preferably, the volume% to 50 volume% is more preferably 10 volume% to 40 volume%. When the content of the conductive fine particles is too small, sufficient electrical conduction may be difficult to be obtained. On the other hand, when the content of the conductive fine particles is too large, the conductive particles may come into contact with each other and the function as an anisotropic conductive material may be difficult to be exhibited. .

The film thickness of the anisotropic conductive material, the coating film thickness of the paste and the adhesive, and the printed film thickness are calculated from the average particle diameter of the conductive fine particles to be used and the specifications of the electrode to be connected, and the conductive fine particles are sandwiched between the electrodes to be connected. It is preferable to set such that the gaps between the bonded substrates on which the electrodes to be connected are formed are sufficiently satisfied by the binder resin layer.

The anisotropic conductive material of the present invention not only exhibits high conductivity but also does not cause peeling or breakage of the conductive metal layer even under weight compression, and can secure electrical connection between the electrode substrates facing each other. In addition, it is excellent in stability over time, so that even in long-term use, the electrical conductivity between the electrode substrates can be reduced, and the reliability can be improved while maintaining the electrical connection between the electrode substrates.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. In addition, this invention is not limited by the following Example, and is included in the scope of the present invention, as long as it changes in the range which does not deviate from the meaning of this invention. In addition, unless otherwise indicated, "part" means a "mass part" and "%" means the "mass%."

Example  One

Into a four-necked flask equipped with a cooling tube, a thermometer and a dropping port, 526 parts of ion-exchanged water, 1.6 parts of 25% ammonia water, and 118 parts of methanol were added, and 3-methacryloxypropyltrimethoxysilane 30 was added from the dropping port under stirring. Part was added, hydrolysis and condensation reaction of 3-methacryloxypropyltrimethoxysilane was carried out, and an emulsion of polysiloxane particles was prepared. After 2 hours from the start of the reaction, an emulsion of the obtained polysiloxane particles was sampled, and the particle diameter was measured by Coulter Multisizer III (Beckman Coulter). The mass average particle diameter was 1.95 µm.

Subsequently, 90 parts of styrene and divinylbenzene in the solution which melt | dissolved 2.5 parts of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (Daiichi Kogyo Co., Ltd .: "Hytenol (trademark) NF-08") as 175 parts of ion-exchange water as an emulsifier. A solution obtained by dissolving 10 parts, 2 parts of 2,2'-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd .: "V-65") is added, and a TK homomixer (special vaporization company) is used. Emulsion dispersion was carried out at 6000 rpm for 5 minutes, and the emulsion liquid of the monomer component was prepared.

The obtained emulsion was added to the emulsion of polysiloxane particles, and further stirred. After 2 hours from the addition of the emulsion, the mixed solution was sampled and observed under a microscope. As a result, it was confirmed that the polysiloxane particles absorbed and enlarged the monomers.

Subsequently, the reaction solution was heated to 65 ° C. under a nitrogen atmosphere, held at 65 ° C. for 2 hours, and radical polymerization of the monomer components was carried out. The emulsion after radical polymerization was solid-liquid separated, the cake obtained was washed with ion-exchanged water and methanol, and then vacuum dried at 80 캜 for 12 hours to obtain organic inorganic composite particles. The particle size of the organic inorganic composite particles was measured by Coulter Multisizer Type III (Beckman Coulter, Inc.). The mass average particle diameter was 3.7 µm and the coefficient of variation (CV value) was 2.9%. In addition, the measurement and calculation method of the mass mean particle diameter of a particle | grain and CV value (variation coefficient) of a particle diameter are the values computed according to the method mentioned later.

<Hydrophilization treatment>

120 parts of obtained organic-inorganic composite particle | grains were put into the chamber type processing container of the capacity of 500L. The thickness of the particle layer was 0.5 mm. After depressurizing the inside of the chamber to 1 Pa, fluorine (F ₂ ) gas and oxygen (O ₂ ) gas were introduced such that F ₂ : 0.67 Pa (5 Torr) and O ₂ : 80 kPa (600 Torr). F ₂ was 0.83% by volume, and the balance was O ₂ . Thereafter, the treatment was carried out at 30 ° C. for 60 minutes, and then the inside of the chamber was replaced with nitrogen to return to atmospheric pressure.

Next, 100 parts of the obtained gas-treated particles were placed in a 5 ml separable flask, ion-exchanged water was added to make the total amount 5000 parts (particle concentration 2% by mass), and ultrasonic dispersion was performed at room temperature (25 ° C) for 10 minutes. Was carried out. Subsequently, it heated to 85 degreeC, heat-processed for 3 hours, and wash | cleaned the particle | grains (contact with moisture). After cooling to room temperature after that, the particle | grains were filtered and the cake obtained was wash | cleaned in order of ion-exchange water and methanol, and then vacuum-dried at 80 degreeC for 12 hours, and obtained the substrate particle (1). By XPS (ESCA) analysis of the obtained substrate particle 1, a peak of carbon corresponding to a carboxy group was observed at 288 eV. Moreover, the characteristic evaluation was performed by the following method, and the evaluation result was shown in Table 1. Moreover, alkali dispersibility of the substrate particle 1 was 1.3%.

<Catalyzed, electroless plating>

In a beaker, 50 parts of "pink shimmer" (Kanizen Co., Ltd.) and 400 parts of ion-exchange water were put, and it mixed. Separately, 10 parts of substrate particles (1) were ultrasonically dispersed in 50 parts of ion-exchanged water, and this was added to the mixed solution, stirred at 30 ° C for 10 minutes to prepare a suspension, and the cake obtained by solid-liquid separation was obtained. And methanol were washed in this order, and vacuum-drying was performed at 100 degreeC under nitrogen atmosphere for 2 hours.

Next, 10 parts of the dried particles were ultrasonically dispersed in 50 parts of ion-exchanged water, and this was added to a solution in which 100 parts of `` Red Schumer (Kanizen Co., Ltd.) '' and 350 parts of ion-exchanged water were mixed. It stirred to make a suspension. The suspension was solid-liquid separated, the cake obtained was washed in the order of ion exchanged water and methanol, vacuum dried at 100 DEG C for 2 hours under nitrogen atmosphere, and palladium was adsorbed onto the surface of the substrate particle (1).

Substrate particles activated by palladium were added to 500 parts of ion-exchanged water, and sonication was performed for 30 minutes to sufficiently disperse the particles to obtain a fine particle suspension. While stirring this fine suspension at 50 degreeC, the electroless plating liquid (pH7.5) consisting of 50 g / L nickel sulfate hexahydrate, 20 g / L sodium hypophosphite monohydrate, 2.5 g / L dimethylamine borane, and 50 g / L citric acid It was gradually added to the fine particle suspension, and electroless nickel plating of the base particle was performed. Particles in the plating treatment were sampled over time and observed by a scanning electron microscope (SEM, HITACHI Co., Ltd .: "S-3500N"), measuring ten arbitrary particle diameters, and measuring results of the substrate particles before the plating treatment. The plating thickness was calculated from the difference of and the addition of the electroless plating solution was stopped when the plating thickness became 0.1 µm. The obtained conductive fine particles were separated by filtration, washed with ion-exchanged water, further washed with methanol, and vacuum dried at 60 ° C. for 12 hours to obtain conductive fine particles (1).

Example  2

150 parts of ion-exchange water which melt | dissolved 2 parts of said "Hytenol NF-08" as a dispersing agent was thrown into the four neck flask provided with the cooling tube, the thermometer, and the dropping-out port. Next, what melt | dissolved the said "V-65" as a polymerization initiator was added to 100 parts of divinylbenzene, and it emulsified-dispersed at 5000 rpm for 5 minutes by TK homomixer (special vaporization company), and adjusted suspension.

250 parts of ion-exchange water was added to this suspension, it heated up to 65 degreeC under nitrogen atmosphere, it carried out at 65 degreeC for 2 hours, and performed radical polymerization. The emulsion after radical polymerization was solid-liquid separated, the cake obtained was washed with ion-exchanged water and methanol, and the classification operation was further performed. Vinyl polymer fine particles were obtained by drying the particle | grains after classification at 80 degreeC for 12 hours. The mass average particle diameter of this vinyl polymer microparticle was 2.1 micrometers, and the coefficient of variation (CV value) was 25.0%.

120 parts of obtained vinyl polymer microparticles | fine-particles were hydrophilized by the method similar to Example 1, and precision classification was performed, and the base material particle 2 was obtained. The mass average particle diameter of the substrate particles was 3.0 µm, and the variation coefficient (CV value) was 4.0%. Moreover, the peak of the carbon corresponding to a carboxy group was observed by 288 eV by XPS (ESCA) analysis of the obtained base particle (2). The alkali dispersibility of the substrate particle 2 was 0.6%.

10 parts of the obtained substrate particles (2) were subjected to catalysis treatment and electroless plating treatment in the same manner as in Example 1 to obtain conductive fine particles (2) having a conductive metal layer of nickel.

Example  3

30 parts of the conductive fine particles (1) obtained in Example 1 and 3 parts of methyl methacrylate / styrene / divinylbenzene crosslinked resin fine particles having a mass average particle size of about 0.3 μm obtained by elongation emulsion polymerization were mixed and hybridized. System (Nara Machinery Co., Ltd.): "Hybridization System NHS-0 Type" is used, and the insulating coating of the conductive fine particles (1) is performed by the impact method (high-speed airflow) (processing condition: 13000 rpm, 10 minutes). , Electroconductive fine particles (3) were obtained.

Comparative example  One

The monomer mixture consisting of 80 parts of divinylbenzene and 20 parts of 2-hydroxyethyl methacrylates was suspension-polymerized. By classifying the obtained polymer, 10 parts of vinyl polymer particles (3.5 micrometers of mass average particle diameters, 4.9% of particle diameters of particle diameters) which have a hydroxyl group on the particle surface were obtained. Next, 10 parts of obtained vinyl polymer microparticles | fine-particles were added in 100 parts of tetrahydrofuran (THF), and it disperse | distributed uniformly using the ultrasonic disperser.

10 parts of triethylamines were added to the dispersion liquid of a polymer particle, it heated up to 60 degreeC, 10 parts of methacrylic acid chlorides were dripped here, and it was made to react for 3 hours. After completion | finish of reaction, the polymer particle was isolate | separated by filtration, and it wash | cleaned enough with THF and methanol, and obtained microparticles | fine-particles which introduced the ethylenically unsaturated group on the surface.

10 parts of obtained microparticles | fine-particles are disperse | distributed in 100 parts of isopropanol (IPA), Furthermore, 20 parts of methacrylic acid, 20 parts of ethyl methacrylates, and a polymerization initiator (Japan oil company: "Perocta (trademark) O") 0.8 Part was added, and polymerization reaction was carried out at 70 ° C. for 3 hours under nitrogen atmosphere to obtain the substrate particles (3) having a resin coating layer having a thickness of 0.04 μm. The mass average particle diameter of the obtained substrate particle 3 was 3.0 micrometers, and the variation coefficient (CV value) of the particle diameter was 4.0%. Moreover, when the obtained base particle 3 was analyzed by XPS (ESCA), the peak of carbon corresponding to a carboxy group was observed at 288 eV. The alkali dispersibility of the substrate particle 3 was 1.4%.

Catalytic treatment and electroless plating were carried out in the same manner as in Example 1 using 10 parts of the obtained substrate particles (3) to obtain comparative conductive fine particles (1) having a nickel coating layer.

Comparative example  2

5 parts of polystyrene particles having a mass mean particle diameter of 0.8 mu m are used as seed particles, which are mixed with 500 parts of ion-exchanged water and 100 parts of 5 mass% polyvinyl alcohol aqueous solution, placed in a detachable flask, stirred, Disperse evenly.

Next, 128 parts of polytetramethylene glycol diacrylate and 32 parts of divinylbenzene were added to the solution which melt | dissolved 9 parts of lauryl sulfate triethanolamine, 118 parts of ethanol, and 12 parts of benzoyl peroxide with 1035 parts of ion-exchange water, and added the emulsion component of the monomer component The emulsion was divided into several portions, added to a detachable flask, stirred for 12 hours, and the monomer particles were absorbed into the seed particles.

Thereafter, as a dispersion stabilizer, 250 parts of 5 mass% polyvinyl alcohol aqueous solution and 250 parts of 30 mass% polyacrylic acid aqueous solution were added, nitrogen gas was introduced and reacted at 90 ° C. for 9 hours. The liquid was separated, the cake obtained was washed with ion-exchanged water and methanol, and a classification operation was further performed. The substrate particle (4) was obtained by drying the particle | grains after classification at 80 degreeC for 12 hours. The mass average particle diameter of the obtained substrate particle 4 was 3.0 µm, and the variation coefficient (CV value) of the particle diameter was 4.3%.

Using 10 parts of the obtained substrate particles (4), catalysis treatment and electroless plating treatment were carried out in the same manner as in Example 1 to obtain comparative conductive fine particles (2) having a nickel coating layer.

Comparative example  3

In a four-necked flask equipped with a cooling tube, a thermometer and a dropping port, 200 parts of methanol, 15 parts of ultrapure water, 25 parts of styrene, 5 parts of 2,2'-azobis (2,4-dimethylvaleronitrile), polyvinyl blood 18.7 parts (as a dispersion stabilizer) of ralidone (molecular weight 40,000) was added. Thereafter, the mixed solution was heated up to 60 ° C, and polymerization reaction was carried out for 24 hours under nitrogen atmosphere.

Thereafter, the obtained polymer was solid-liquid separated, thoroughly washed with ultrapure water and methanol, and then vacuum dried at 50 ° C. for 12 hours to obtain polymer seed particles in powder form. The mass average particle diameter of the obtained polymer seed particles was 1.13 µm, and the coefficient of variation (CV value) of the particle diameter was 2.5%.

Next, 2 parts of polymer seed particles were uniformly dispersed in 450 parts of 0.2 parts of an aqueous solution of sodium lauryl sulfate, to prepare a dispersion liquid of polymer seed particles.

Next, a monomer mixture of 60 parts of styrene and 40 parts of divinylbenzene was added to a solution obtained by dissolving 1.5 parts of benzoyl peroxide (initiator) in 300 parts of a 0.2% by mass aqueous solution of sodium lauryl sulfate, and then added to a TK homomixer (special vaporization company). The emulsion was dispersed for 5 minutes at 6000 rpm to prepare an emulsion of monomer components. The emulsion of the obtained monomer component was added to the dispersion of the polymer seed particles, and the monomer seed was absorbed into the polymer seed particles at room temperature.

After visually confirming that the absorption of the monomer component was completed, polyvinyl alcohol (500 parts of 5 mass% aqueous solution was added, the temperature of the reactor was raised to 80 ° C., and the polymerization reaction was carried out for 5 hours. The microparticles were washed several times with ultrapure water and ethanol and then vacuum dried at room temperature The mass average particle diameter of the obtained crosslinked polymer microparticles was 3.5 µm, and the coefficient of variation (CV value) of the particle diameter was 2.6%.

Surface hydrophilization treatment

In a fluidized bed reactor (Fluidized bed type), 150 parts of crosslinked polymer fine particles were charged and the inside of the reactor was kept in a vacuum state. Subsequently, after argon gas was introduced into the reactor, the pressure in the reactor was fixed at 0.5 Torr. The fluidization rate of the crosslinked polymer microparticles at this time was 18.7 cm / s. After the plasma treatment was performed for 10 minutes at an output of 100 W, the fine particles were exposed to air for 10 minutes to hydrophilize the surface of the crosslinked polymer fine particles, thereby obtaining the substrate particles (5). The mass mean particle diameter of this base particle (5) was 3.5 µm, and the variation coefficient (CV value) of the particle diameter was 2.6%.

Catalytic treatment and electroless plating treatment were performed on 10 parts of the substrate particles 5 in the same manner as in Example 1 to obtain comparative conductive fine particles 3 having a plating layer of nickel.

Comparative example  4

Using 10 parts of the comparative conductive fine particles (3) obtained in Comparative Example 3, an insulating coating treatment was carried out in the same manner as in Example 3 to obtain comparative conductive fine particles (4).

Comparative example  5

0.5 part of the substrate particles (1) obtained in Example 1 were added to 100 ml of an oxidation treatment liquid adjusted to be 200 ml / l and 400 g / l of chromic acid in advance, and heat-treated at 70 ° C. for 5 minutes. After cooling to room temperature, it was filtered and the obtained fine particles were washed with water. Vacuum drying was carried out at 80 ° C. for 12 hours to obtain substrate particles (6). XPS (ESCA) analysis of the obtained base particle (3) revealed a peak of carbon corresponding to the carboxy group at 288 eV. The alkali dispersibility of the substrate particle 6 was 0.8%.

Using the obtained base particle 6, the catalytic treatment and the electroless plating process were performed by the method similar to Example 1, and the comparative electroconductive fine particles 5 which have a nickel plating layer were obtained.

[Average particle diameter, coefficient of variation of particle diameter (CV value)]

The average particle diameter of the particles was determined by Coulter Multisizer Type III (Beckman Coulter, Inc.), the particle diameter of 30000 particles was determined, the volume average particle diameter was calculated, and the value was defined as the mass average particle diameter. CV value (variation coefficient) of particle diameter was computed according to the following formula.

는 평균입자경을 나타낸다.σ standard deviation of particle size,

Represents the average particle diameter.

[Total Fluorine Content, Elution and Non-Elution Fluorine Content]

By the method described above, the total amount of fluorine and the content of elutable fluorine were calculated, and the difference was regarded as the non-elutable fluorine content.

[Measurement of Acid Value (KOH Neutralization)]

0.5 g of the substrate particles obtained in the above Examples and Comparative Examples were weighed, and this was added to ultrapure water (prepared as an "Organo company" PURELITE "PRA-0015-000 type, 18.2 MΩcm or less), and the total amount was adjusted to 50 g. , Sonication was performed for 10 minutes. Subsequently, neutralization titration was performed using an automatic titrator (COM-1600, Hiranuma Co., Ltd.), and the addition amount of the titrant when the amount of potential change was maximum was calculated, and the acid value was calculated by the following equation. In addition, a KOH aqueous solution having a concentration of 0.005M was used as the titration solution.

[Identification of carboxyl group and carboxylate]

Carboxy groups on the surface of the substrate particle after hydrophilization treatment using an X-ray photoelectron spectroscopy apparatus (ESCA: Albakh Pi Co., Ltd., Scanning X-ray photoelectron spectrometer "PHI quantera SXM (Scanning X-ray Microprobe)"). The presence or absence of the formation of carboxylate was confirmed.

[Surface abundance of C, O, F, N, Na and Si atoms]

Using X-ray photoelectron spectroscopy (ESCA; manufactured by JEOL; JPS-9000MC), the abundance (mol%) of C, N, O, F, Na, and Si atoms on the surface of the substrate particles and the hydrophilized fine particles was determined. The relative surface abundance (%) of each atom, M (sodium atom, etc.) and abundance (atom ratio) of the fluorine atoms were calculated by the following formula.

Relative surface abundance (%) of C atom = 100 × [abundance of C atom (mol%) / (abundance of C atom (mol%)) + abundance of N atom (mol%) + abundance of O atom (Mol%) + F atom abundance (mol%) + Na atom (mol%) + Si atom (mol%))]

Relative surface existence rate (%) of O atom = 100 x [abundance of O atom (mol%) / (abundance of C atom (mol%)) + abundance of N atom (mol%) + abundance of O atom (Mol%) + F atom abundance (mol%) + Na atom (mol%) + Si atom (mol%))]

Relative surface abundance (%) of F atoms = 100 x [abundance of F atoms (mol%) / (abundance of C atoms (mol%)) + abundance of N atoms (mol%) + abundance of O atoms (Mol%) + F atom abundance (mol%) + Na atom (mol%) + Si atom (mol%))]

Relative surface abundance (%) of Na atom = 100 x [abundance of Na atom (mol%) / (abundance of C atom (mol%)) + abundance of N atom (mol%) + abundance of O atom (Mol%) + F atom abundance (mol%) + Na atom (mol%) + Si atom (mol%))]

Relative Surface Presence (%) of Si Atom = 100 × [Abundance of Si Atoms (mol%) / (Abundance of C Atoms (mol%)) + N Abundance (mol%) + O Atoms (Mol%) + F atom abundance (mol%) + Na atom (mol%) + Si atom (mol%))]

Relative surface abundance (%) of N atoms = 100 x [abundance of N atoms (mol%) / (abundance of C atoms (mol%)) + abundance of N atoms (mol%) + abundance of O atoms (Mol%) + F atom abundance (mol%) + Na atom (mol%) + Si atom (mol%))]

M / C = [Abundance of Na atom (mol%) / C atom of abundance (mol%)]

F / C = [Abundance of F atoms (mol%) / C atom of abundance (mol%)]

[Hydrophobicity]

By the method described above, the degree of hydrophobicity of the substrate particles was calculated.

[Compression failure load]

By the above method, the compressive fracture load (mN) of the substrate particles and the conductive fine particles was calculated. The results are shown in Tables 1 and 2, respectively.

[Alkali dispersibility]

One part of the substrate particles was added to 20 parts of a 0.1 mass% sodium hydroxide aqueous solution (a mixed solution of water: methanol in a mass ratio of 1: 1) and stirred at 25 ° C. for 20 minutes, followed by Coulter Multisizer III type (Beckman Coulter, The average particle diameter Da of the volume basis is measured using a measurement range of 1 µm to 10 µm, with simultaneous passage correction.

Subsequently, one part of the substrate particles was added to 4000 parts of 1 mass% Hythenol® N-08 (Daiichi Kogyo Pharmaceutical Co., Ltd.) aqueous solution, sonicated for 10 minutes, and the substrate particles were dispersed in an aqueous solution. Enlarged by 500 times with HiROX, KH-2700), and confirmed that there were no aggregated particles, using the Coulter Multisizer Type III (measurement range of 1 µm to 10 µm, with simultaneous passage correction), and the average diameter (Db) based on volume. (Average primary particle diameter) is measured.

The values of Da and Db obtained are introduced into the following formulas to calculate the dispersibility α (%) in the alkaline solution.

α (%) = (| Da-Db | / Db) × 100

[Observation of Plating Cracks of Conductive Particulates]

About the obtained electroconductive fine particle, the surface of electroconductive fine particle is observed by the scanning electron microscope (SEM, HITACH company: "S-3500N") by 1000 times the measurement magnification, and if the crack of an electroconductive metal layer is 0.1% or less, it will be "0. (Good) "and when the number of cracks of an electroconductive metal layer exceeded 0.1%, it evaluated as" (defect). " In addition, the number of observations was made into 10000 pieces.

[Evaluation of Plating Defects of Conductive Fine Particles]

About the obtained electroconductive fine particle, the surface of electroconductive fine particle was observed by the scanning electron microscope (SEM) at 1000 times the measurement magnification, and even if it is a part, the electroconductive fine particle in which the part in which the metal layer is not coat | cover exists does not exist. The thing was made into "0". The results are shown in Table 2. In addition, the number of observations was made into 10000 pieces.

In Table 2, neither the plating crack nor the plating defect was observed in the electroconductive fine particles of Examples 1 and 2 whose acid value of a substrate particle is 0.05 mgKOH / g or more. As a result, in Examples 1 and 2, agglomeration and the like between the substrate particles did not occur during the electroless plating treatment, or because the affinity between the substrate particles and the conductive metal layer was high, the conductivity continued on the substrate surface. It is thought that a metal layer was formed. Moreover, it is thought that reliable electrical connection can be ensured by using these electroconductive fine particles.

On the other hand, plating cracks and plating defects were generated in the conductive fine particles of Comparative Examples 1 and 2 that were not subjected to the hydrophilization treatment. Therefore, in these examples, it is considered that the aggregation of the substrate particles occurred during the electroless plating treatment, or the affinity between the substrate particles and the conductive metal layer was low, or for both reasons. In Comparative Examples 3 and 4, in the plasma treatment and Comparative Example 5, the surface hydrophilization treatment of the crosslinked polymer fine particles was carried out using chromic acid, but plating cracks and plating defects were generated in either of the fine particles. It was found that the adhesion between the particles and the conductive metal layer was insufficient. In addition, the substrate particles subjected to the chromic acid treatment of Comparative Example 5 are particularly markedly lowered in the compressive fracture load after plating, and it is considered that the substrate particles are subjected to damage by the acid treatment.

[Evaluation of Anisotropic Conductive Material]

The anisotropic conductive material was produced using the electroconductive fine particles obtained in Examples 1-3 and Comparative Examples 1-5, and the resistance value between electrodes was evaluated.

1 g of conductive fine particles was mixed and dispersed in 100 g of an epoxy resin (Mitsui Chemical Co., Ltd .: "Stract Bond (registered trademark) XN-5A"), to prepare a conductive adhesive paste. Thereafter, 0.1 mg of the paste was sandwiched between two glass substrates on which an ITO transparent electrode film was formed on the inner surface, and thermally press-bonded at 150 ° C. for 30 minutes while applying a pressure of 13.7 MPa by a press to prepare a test piece.

PC test (Pressure cooker test: 120 degreeC, 2 atmospheres, 24 hours) was performed about the produced test piece, and the resistance value between electrodes before and behind a PC test, and its change were measured. The results are shown in Table 3.

In Table 3, when the anisotropic conductive material produced from the conductive fine particles of Examples 1 to 3 having an acid value of 0.05 mgKOH / g or more was used, the rate of increase of the resistance value before and after the PC test was low, resulting in high reliability. Electrical conduction is obtained. Therefore, in the electroconductive fine particles of Examples 1-3, it turned out that adhesiveness between a substrate particle and a conductive metal layer is favorable.

On the other hand, in the case of the anisotropic conductive material produced by the electroconductive fine particles of Comparative Examples 1-5 which the acid value of a substrate particle does not satisfy 0.05 mgKOH / g, the increase rate of the resistance value before and behind a PCT test is high, and these electroconductivity It was found that the adhesion between the substrate particles in the fine particles and the conductive metal layer was inferior.

As a result, the anisotropic conductive material using the conductive fine particles of the present invention having excellent adhesion between the substrate particles and the conductive metal layer does not cause peeling or breakage of the conductive metal layer even when weighted compression, and electrically connects the electrode substrates facing each other. Can be secured. In addition, since the time-lapse stability is excellent, it has been found that even in long-term use, there is no deterioration in conductivity due to plating cracks, and the reliability that can maintain electrical connection between electrode substrates is high.

Example  4

In a four-necked flask equipped with a cooling tube, a thermometer, and a dropping port, 135 parts of ion-exchanged water, 0.2 part of 25% ammonia water, and 67 parts of methanol were added, and 3-methacryloxypropyltrimethoxysilane 12 was added from the dropping port under stirring. Part was added, hydrolysis and condensation reaction of 3-methacryloxypropyltrimethoxysilane was carried out, and an emulsion of polysiloxane particles was prepared. After 2 hours from the start of the reaction, the emulsion of the obtained polysiloxane particles was sampled, and the particle diameter was measured by Coulter Multisizer III (Beckman Coulter, Inc.). The mass average particle diameter was 2.38 µm.

Subsequently, divinylbenzene 960 (New Japan) was dissolved in a solution obtained by dissolving 1.25 parts of polyoxyethylene styrenated phenylether sulfate ammonium salt (Daiichi Kogyo Co., Ltd .: `` Hytenol® NF-08 '') as 10 parts of ion-exchanged water as an emulsifier. Steel chemical company) 8.4 parts, 2,2'-azobis (2,4-dimethylvaleronitrile) (wako Pure Chemical Industries, Ltd .: "V-65") was added, the solution which melt | dissolved, TK homomixer (special vaporization company) Was emulsified and dispersed at 6000 rpm for 5 minutes to prepare an emulsion of monomer components.

The obtained emulsion was added to an emulsion of polysiloxane particles, and further stirred. After 2 hours from the addition of the emulsion, the mixed solution was sampled and observed under a microscope. As a result, it was confirmed that the polysiloxane particles absorbed and enlarged the monomers.

Subsequently, the reaction solution was heated to 65 ° C. under a nitrogen atmosphere, held at 65 ° C. for 2 hours, and radical polymerization of the monomer components was carried out. The emulsion after radical polymerization was solid-liquid separated, the cake obtained was washed with ion-exchanged water and methanol, and then vacuum dried at 80 ° C for 12 hours to obtain organic inorganic composite particles. The particle size of the organic inorganic composite particles was measured by Coulter Multisizer Type III (Beckman Coulter, Inc.). The mass average particle size was 3.0 µm and the coefficient of variation (CV value) was 3.3%.

Except having made the composition gas and the gas temperature in a chamber into the conditions shown in Table 4, the hydrophilization process was performed by the method similar to Example 1, and the base material particle 7 was obtained. By XPS (ESCA) analysis of the obtained substrate particle 7, a peak of carbon corresponding to a carboxy group was observed at 288 eV. Moreover, the characteristic evaluation was performed by the said method, and the evaluation result was shown in Table 4.

Example  5

The hydrophilization treatment was performed under the conditions shown in Table 4 of the composition of the mixed gas and the gas temperature in the chamber. Subsequently, 7 g of the particles after the hydrophilization treatment was immersed in a 0.25 N sodium hydroxide aqueous solution (particle concentration 2% by mass) and subjected to alkali treatment at 85 ° C. for 3 hours under stirring. The particles were filtered and then immersed in 85 ° C. ion-exchanged water (particle concentration 6.3% by mass), and washed at the same temperature for 3 hours. After cooling to room temperature, the particles were filtered, washed in the order of ion exchanged water and methanol, and further vacuum dried at 80 ° C. for 12 hours to obtain the substrate particles (8). XPS (ESCA) analysis of the obtained substrate particles (8) also confirmed the presence of Na in which carbon peaks corresponding to carboxylates were observed at 288 eV.

Example  6

Except having made the composition gas and the gas temperature in a chamber into the conditions shown in Table 4, hydrophilization treatment and alkali treatment were performed by the method similar to Example 5, and the base material particle 9 was obtained. By XPS (ESCA) analysis of the obtained substrate particle 9, a peak of carbon corresponding to carboxylate was observed at 288 eV, and the presence of Na was also confirmed.

Example  7

Into a four-necked flask equipped with a cooling tube, a thermometer, and a dropping port, 135 parts of ion-exchanged water, 0.2 part of 25% ammonia water, and 67 parts of methanol were added, and 3-methacryloxypropyltrimethoxysilane 10 was added from the dropping port under stirring. Part was added, hydrolysis and condensation reaction of 3-methacryloxypropyltrimethoxysilane was carried out, and an emulsion of polysiloxane particles was prepared. After 2 hours from the start of the reaction, an emulsion of the obtained polysiloxane particles was sampled, and the particle diameter was measured by Coulter Multisizer III (Beckman Coulter). The mass average particle diameter was 2.15 mu m.

Subsequently, 1,6-hexanediol di 10 parts of methacrylate, the solution which melt | dissolved 0.2 parts of 2,2'- azobis (2, 4- dimethylvaleronitrile) (wako Pure Chemical Industries: "V-65") were added, and TK homomixer (special vaporization company) Was emulsified and dispersed at 6000 rpm for 5 minutes to prepare an emulsion of monomer components.

The obtained emulsion was added to an emulsion of polysiloxane particles, and further stirred. After 2 hours from the addition of the emulsion, the mixed solution was sampled and observed under a microscope. As a result, it was confirmed that the polysiloxane particles absorbed and enlarged the monomers.

Subsequently, the reaction solution was heated to 65 ° C. under a nitrogen atmosphere, held at 65 ° C. for 2 hours, and radical polymerization of the monomer components was carried out. The emulsion after radical polymerization was solid-liquid separated, the cake obtained was washed with ion-exchanged water and methanol, and then vacuum dried at 80 ° C for 12 hours to obtain organic inorganic composite particles. The particle diameter of this organic-inorganic composite particle was measured by Coulter Multisizer Type III (Beckman Coulter, Inc.). The mass average particle diameter was 2.9 µm and the coefficient of variation (CV value) was 3.6%.

Except having made the composition gas and the gas temperature in a chamber into the conditions shown in Table 4, hydrophilization treatment and alkali treatment were performed by the method similar to Example 5, and the base material particle 10 was obtained. By XPS (ESCA) analysis of the obtained substrate particle 10, a peak of carbon corresponding to carboxylate was observed at 288 eV, and the presence of Na was also confirmed. Moreover, the characteristic evaluation was performed by the said method, and the evaluation result was shown in Table 4.

Example  8

Except having made the composition gas and the gas temperature in a chamber into the conditions shown in Table 4, hydrophilization treatment and warm water washing were performed by the method similar to Example 5, and the base material particle 11 was obtained. By XPS (ESCA) analysis of the obtained substrate particle 11, the peak of carbon corresponding to a carboxy group was observed at 288 eV.

Example  9

Except having made the composition gas and the gas temperature in a chamber into the conditions shown in Table 4, hydrophilization treatment and alkali treatment were performed by the method similar to Example 5, and the base material particle 12 was obtained. By XPS (ESCA) analysis of the obtained substrate particle 12, a peak of carbon corresponding to carboxylate was observed at 288 eV.

Example  10

The emulsion of the monomer component of Example 7 was the same as in Example 7, except that 10 parts of 1,6-hexanediol dimethacrylate were changed to 3 parts of styrene and 7 parts of divinylbenzene 960 (New Nippon Steel Chemical Co., Ltd.). Organic inorganic composite particles were obtained by the method. The organic inorganic composite particles had an average particle diameter of 3.1 mu m and a coefficient of variation (CV value) of 3.5%.

Subsequently, hydrophilization treatment and alkali treatment were performed under the same conditions as in Example 9 to obtain the substrate particles 13. By XPS (ESCA) analysis of the obtained substrate particle 13, a peak of carbon corresponding to carboxylate was observed at 288 eV.

Example  11

In the emulsion of the monomer component of Example 7, the same method as in Example 7, except that 10 parts of 1,6-hexanediol dimethacrylate was changed to 7 parts of methyl methacrylate and 3 parts of ethylene glycol dimethacrylate. As a result, organic-inorganic composite particles were obtained. The organic inorganic composite particles had an average particle diameter of 3.1 mu m and a coefficient of variation (CV value) of 3.5%.

Subsequently, hydrophilization treatment and warm water washing were performed under the same conditions as in Example 4 to obtain the substrate particles 14. By XPS (ESCA) analysis of the obtained substrate particles 14, a peak of carbon corresponding to carboxylate was observed at 288 eV.

Comparative example  6

In a four-necked flask equipped with a cooling tube, a thermometer, and a dropping port, 900 parts of ion-exchanged water, 1.2 parts of 25% ammonia water, and 225 parts of methanol were added, and 3-methacryloxypropyltrime, previously adjusted from the dropping port, was stirred. A mixed solution of 50 parts of methoxysilane and 75 parts of methanol was added, and hydrolysis and condensation reaction of 3-methacryloxypropyltrimethoxysilane was carried out to prepare an emulsion of polysiloxane particles.

After 2 hours from the start of the reaction, the emulsion of the obtained polysiloxane particles was sampled, and the particle diameter was measured by Coulter Multisizer III (Beckman Coulter, Inc.). The mass average particle diameter was 1.41 µm.

Subsequently, 67.5 parts of styrene and divinyl in the solution which melt | dissolved 6.25 parts of polyoxyethylene styrenated phenyl ether sulfate ammonium salt (Daiichi Kogyo Co., Ltd .: "Hytenol (trademark) NF-08") as 250 parts of ion-exchange water as an emulsifier. A solution in which 87.5 parts of benzene 960 (New Nippon Steel Chemical Co., Ltd.), 75 parts of methacrylic acid, and 3 parts of 2,2'-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd .: `` V-65 '') are dissolved. Was added, and the emulsion of the monomer component was prepared by emulsifying and dispersing at 6000 rpm for 5 minutes by a TK homomixer (special vaporization company).

The obtained emulsion was added to the emulsion of polysiloxane particles, and further stirred. After 2 hours from the addition of the emulsion, the mixed solution was sampled and observed under a microscope. As a result, it was confirmed that the polysiloxane particles absorbed and enlarged the monomers.

Subsequently, 7.5 parts of polytops 7010 (Hakuto Co., Ltd.) were added to the emulsion of polysiloxane particles, the reaction solution was heated up to 65 ° C under a nitrogen atmosphere, held at 65 ° C for 2 hours, and the radical polymerization of the monomer components was carried out. The emulsion after radical polymerization was solid-liquid separated, the cake obtained was washed with ion-exchanged water and methanol, and then vacuum-dried at 120 캜 under a nitrogen atmosphere for 2 hours to obtain substrate particles (15). XPS (ESCA) analysis of the obtained substrate particle 15 showed a peak of carbon corresponding to a carboxy group at 288 eV, but the presence of Na was not confirmed.

Comparative example  7

The base material particle 16 was obtained by the method similar to the comparative example 6 except having changed the composition of the emulsion component of the monomer component into 112.5 parts of styrene, 112.5 parts of divinylbenzene 960 (New Nippon Steel Chemical Co., Ltd.), and 25 parts of methacrylic acid. XPS (ESCA) analysis of the obtained substrate particle 16 showed a peak of carbon corresponding to a carboxy group at 288 eV, but the presence of Na was not confirmed.

Comparative example  8

The substrate particle 17 was obtained in the same manner as in Example 1 except that the hydrophilization treatment was not performed. Although XPS (ESCA) analysis of the obtained substrate particle 17 was carried out, the peak of carbon corresponding to a carboxy group was not confirmed.

In Table 4, the substrate particles obtained in Examples 1 to 11 had a degree of hydrophobicity of 0 by hydrophilization treatment. In addition, the results of Examples 5 to 10 show that hydrophilization treatment proceeds in the same manner when the mixed gas contains an inert gas, thereby obtaining hydrophilized fine particles.

Subsequently, after performing the sodium adsorption treatment on the substrate particles obtained in Examples 1 to 11 and Comparative Examples 1 to 8, the particles were prepared using an X-ray photoelectron spectroscopy apparatus (JEOL; JPS-9000MC) according to the above method. The abundance of C, O, F, Na, and Si atoms in the surface was measured. The results are shown in Table 5.

Sodium adsorption treatment

20 mass parts of aqueous solution which melt | dissolved sodium hydroxide so that the density | concentration might be 0.1 mass%, and 1 mass part of particle | grains were mixed with the mixed solution of the water: methanol ratio of 1: 1 by mass ratio, and this suspension was stirred at 25 degreeC for 1 hour. It was.

Subsequently, the suspension was solid-liquid separated, the substrate particles were washed with 100 parts by mass of ion-exchanged water, then washed with 33 parts by mass of methanol, and the substrate particles were washed, followed by vacuum drying at 120 ° C. for 2 hours.

In Table 5, as a result of the relative surface existence rate (%) of each atom in the substrate particles of Examples 1 to 9, the amount of sodium atoms in the substrate particles after the hydrophilization treatment was relatively increased as compared with before the hydrophilization treatment. It was confirmed that carboxyl group (carboxylate) was produced by this.

Using the substrate particles (7) to (17) obtained in Examples 4 to 11 and Comparative Examples 6 to 8, the following palladium adsorption treatment, catalysis treatment, and electroless plating treatment were performed to conduct conductive fine particles (4) to ( 11) and Comparative Electroconductive Fine Particles 6 to 8 were manufactured. Moreover, the plating property of electroconductive fine particles was evaluated in accordance with the said method.

<Palladium adsorption treatment>

In a beaker, 10 parts of "pink shimmer" (Kanizen Co., Ltd.) and 70 parts of ion-exchanged water were put and mixed. Separately, an ultrasonic dispersion of 2 parts of substrate particles was prepared in 10 parts of ion exchanged water, and this was added to the mixed solution, and 10 parts of ion exchanged water washed in the beaker was also added to the mixed solution. The mixed solution was stirred at 30 ° C for 10 minutes to give a suspension, and the cake obtained by solid-liquid separation was washed with 30 parts of ion-exchanged water.

The obtained cake was transferred to a beaker, ultrasonically dispersed in 80 parts of ion-exchanged water, and 20 parts of "Red Shimmer" (Japan Kanizen Co., Ltd.) was added thereto, and stirred at 30 ° C for 10 minutes to obtain a suspension. This suspension was solid-liquid separated, the cake obtained was washed with 20 parts of ion-exchanged water, vacuum-dried at 100 degreeC under nitrogen atmosphere for 2 hours, and the base particle which palladium adsorb | sucked to the surface was obtained.

<Catalyzed treatment>

In a beaker, 10 parts of "pink shimmer" (Kanizen Co., Ltd.) and 70 parts of ion-exchanged water were put and mixed. Separately, a beaker was prepared by ultrasonically dispersing 2 parts of the substrate particles in 10 parts of ion-exchanged water, and this was added to the mixed solution, followed by 10 parts of ion-exchanged water washed in the beaker. The mixed solution was stirred at 30 ° C for 10 minutes to give a suspension, and the cake obtained by solid-liquid separation was washed with 30 parts of ion-exchanged water.

The obtained cake was transferred to a beaker, 80 parts of ion-exchanged water was added, ultrasonic dispersion was carried out, and 20 parts of "Red Schumer (Kanizen Co., Ltd.)" were added here, it stirred at 30 degreeC for 10 minutes, and it was set as suspension. This suspension was solid-liquid separated, the cake obtained was washed with 20 parts of ion-exchanged water, vacuum-dried at 100 degreeC under nitrogen atmosphere for 2 hours, and the base particle which palladium adsorb | sucked to the surface was obtained.

<Electroless Plating>

0.2 parts of substrate particles activated by palladium were added to 8 parts of ion-exchanged water, and after sonication, the particulate suspension was warmed in a 70 ° C water bath. While stirring this suspension, 12 parts of "Summer S680 (Kanizen Co., Ltd.)) heated at 70 degreeC was added separately, and electroless nickel plating was performed. After confirming that the generation of hydrogen gas had been completed, solid-liquid separation was performed, ion-exchanged water and methanol were washed sequentially, and vacuum drying was performed at 100 ° C for 2 hours to obtain conductive fine particles.

[Observation of conductive fine particles]

About the obtained electroconductive fine particles 6 and 9, particle | grains were observed with the scanning electron microscope (SEM, HITACHI company "S-3500N"). Further, for the conductive fine particles 9, an ultra-high resolution field emission scanning electron microscope (FE-SEM, HITACHI Corporation; "S-", equipped with an energy dispersive X-ray spectrometer (EDS, manufactured by EDAX; "Genesis2000"). 4800 '), and the surface of electroconductive fine particles was observed and elemental analysis was performed.

Table 6 shows the results of observation and evaluation of the hydrophobicity and alkali dispersibility of the substrate particles and the plating cracks and plating defects of the conductive fine particles after the plating treatment. The SEM images of the conductive fine particles (6) and (9) obtained from the substrate particles of Examples 6 and 9 are shown in FIGS. 1 and 2, and the FE-SEM images of the conductive fine particles (9) are shown in FIG. 4, the cross-sectional FE-SEM image of the electroconductive fine particle 9 is shown in FIG.

In addition, in Table 6, "M / C (x10 <^-2>)" shows the value after giving a sodium adsorption process to a substrate particle.

In Table 6, it was found that the electroconductive fine particles of the present invention using base particles having a M / C of 0.5 × 10 ⁻² or more and a hydrophobicity of less than 2% do not generate plating cracks or plating defects, and thus exhibit excellent plating properties. Could.

1 and 2, the conductive fine particles (Example 6) having a substrate particle using a styrene-based monomer and an aromatic divinyl compound as the monomer component are more conductive particles (Example 9) in which the substrate particles are made of an acrylic monomer. It turned out that it is excellent in plating property. FIG. 3 is an FE-SEM image of the conductive fine particles 9 obtained in Example 9, and FIG. 4 is a graph showing the results of elemental analysis by EDS on the portion surrounded by white borders on the particle surface of FIG. 5 is an FE-SEM image showing a cross section of the conductive fine particles 9 obtained in Example 9, but in these drawings, it can be confirmed that the conductive fine particles 9 are coated with nickel on the surface of the substrate particles 12. there was. 4, P is a component derived from the reducing agent in a plating liquid.

In addition, SEM observation of the conductive fine particles (7) and (8) obtained in Examples 7 and 8 showed that the conductive fine particles (7) subjected to alkali treatment to the substrate particles showed good surface properties, but the substrate particles were washed with warm water. In the conductive fine particles 8 not subjected to alkali treatment, abnormal deposition of nickel was confirmed.

(Industrial availability)

The conductive fine particles of the present invention are excellent in adhesion between the substrate particles and the conductive metal layer, and do not cause deterioration of conductivity due to plating cracks even in long-term use, and can maintain electrical connection between electrode substrates. Since this is a high thing, it can be used suitably as an electroconductive material which connects between electrodes, such as an anisotropic conductive film, an anisotropic conductive paste, a conductive adhesive, and a conductive adhesive.

Claims (8)

As electroconductive fine particles which have a substrate particle and the conductive metal layer which coat | covers the surface of a substrate particle,
The said substrate particle is a substrate particle which consists of a vinyl polymer with a mass mean particle diameter of 1000 micrometers or less,
After the substrate particles were subjected to sodium adsorption by the following method, the ratio M / C (atomic ratio) of the total amount of the number of atoms of the alkali metal and nitrogen to the number of atoms of carbon to the number of atoms of carbon measured by X-ray photoelectron spectroscopy (ESCA) was 0.5 × 10 ⁻² or more, and
Conductive fine particles, characterized in that the degree of hydrophobicity is less than 2%:
Sodium adsorption treatment
20 mass parts of aqueous solution which melt | dissolved sodium hydroxide so that the concentration might be 0.1 mass%, and 1 mass part of particle | grains were mixed with the mixed solution of water: methanol in mass ratio 1: 1, and this suspension was stirred at 25 degreeC for 1 hour, , Solid-liquid separation, solvent washing, vacuum drying at 120 ° C. for 2 hours. Electroconductive fine particle of Claim 1 whose M / C (atomic ratio) of the substrate particle before a sodium adsorption process is 0.5x10 <^-2> or more. Electroconductive fine particle of Claim 1 or 2 whose acid value of the substrate particle before sodium adsorption treatment is 0.05 mgKOH / g or more. Electroconductive fine particle of any one of Claims 1-3 whose said alkali metal is sodium. Electroconductive fine particle of any one of Claims 1-4 whose variation coefficient of the particle diameter of the said substrate particle is 15% or less. The conductive fine particles according to any one of claims 1 to 5, wherein the substrate particle has a carboxyl group and / or carboxylate group COOM (M represents an alkali metal ion or an amine cation) on its surface. Electroconductive fine particle of any one of Claims 1-6 which has an insulating resin layer in at least one part of the surface of electroconductive fine particle. It uses the electroconductive fine particle in any one of Claims 1-7, The anisotropic conductive material characterized by the above-mentioned.

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