JPS63251470A - Anisotropically conductive film and production thereof - Google Patents

Abstract

PURPOSE:To obtain an anisotropically conductive film which is inexpensive and slightly different in specific gravity from its base resin and in which a filler is well dispersed, by dispersing a specific electrically conductive filler in a base resin and forming a film having a thickness approximately equal to the particle size of the filler from the resulting compsn. on a substrate. CONSTITUTION:An alkali is added to a water/alcohol dispersion contg. a metal oxide or hydroxide as a seed to prevent the seed from being agglomerated. While maintaining the alkaline condition, a metal alkoxide is added thereto to be hydrolyzed, thus depositing a hydrolyzate of the metal alkoxide on the seed. The resulting particles or black particles obtd. by heat-treating said particles at 250 deg.C or higher are plated with a metal. The resulting electrically conductive filler (A) is dispersed in a base resin (B) to prepare an electrically conductive resin compsn. A film having a thickness approximately equal to the particle size of the filler is formed from the compsn. on a substrate to obtain the desired electrically conductive film.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an anisotropically conductive film and a method for producing the same, and more particularly to an anisotropically conductive film containing a conductive filler and having different conductivity depending on the direction. It relates to its manufacturing method.

Technical background of the invention and its problems In anisotropic conductive films that have different conductivity in the vertical and horizontal directions, conventionally, gold, silver, platinum, etc. were used to impart conductivity to the film. Noble metals or metal powders such as copper, aluminum, and nickel, carbon powders, carbon fibers, etc. have been added to the base resin. However, although carbons are cheap, they have low conductivity.
In general, copper, aluminum, and nickel have problems in that they are easily oxidized and have poor reliability in terms of conductivity. Moreover, since precious metals such as gold are expensive, there is a problem in that production costs are high.

To solve these problems, conductive fillers have been developed in which the surfaces of particles of copper powder, glass beads, synthetic resin, etc. are plated with metal. However, when these fillers are used in paints or adhesives, if the object to be plated is copper powder, the filler will separate from the paint in a short period of time due to the large specific gravity difference with the base resin as a vehicle.
The filler settles, and therefore the filler must be redispersed immediately before each use, which poses a problem of poor workability. Furthermore, when the object to be plated is glass beads, although the difference in specific gravity with the base resin as a vehicle is somewhat improved compared to copper powder, glass beads currently have a particle size of several tens of microns. Therefore, it was not possible to obtain a material that was fully satisfactory in terms of performance.

Furthermore, when the object to be plated is a synthetic resin, the above problem is solved, but the anisotropically conductive film in which the conductive filler is dispersed causes the resin to deform when external pressure is applied. There have been problems in that the conductive layer may peel off or the conductive layer may peel off.

Purpose of the Invention The present invention aims to solve the above-mentioned problems associated with the prior art. It is an object of the present invention to provide an anisotropically conductive film containing the above-mentioned characteristics and an inexpensive method for manufacturing the same.

Summary of the Invention The anisotropically conductive film according to the present invention is produced by adding a metal alkoxide to a water-alcohol dispersion in which metal oxides or metal hydroxides are dispersed as seeds while keeping the dispersion alkaline. Metal plating is applied to the surface of particles obtained by hydrolyzing and adhering metal alkoxide decomposition products onto the seeds, or black particles obtained by heat-treating the particles at 250 ° C. or higher ( a) A conductive filler is dispersed in (b) a base resin, and the thickness of this conductive thin film is approximately equal to the particle size of the conductive filler (a). It is characterized by

The method for producing an anisotropically conductive film according to the present invention includes adding a metal alkoxide to a water-alcohol dispersion in which a metal oxide or metal hydroxide is dispersed as a seed while keeping the dispersion alkaline. Metal plating is applied to the surface of particles obtained by hydrolyzing and adhering metal alkoxide decomposition products onto the seeds, or black particles obtained by heat-treating the particles at 250 ° C. or higher ( a
) A conductive resin composition in which a conductive filler is dispersed in (b) a base resin and optionally (c) a diluent is applied onto a base material, and the conductive filler contained in the composition is disposed on a base material. It is characterized by being applied at a film thickness that is approximately equal to the particle size of the material.

Detailed Description of the Invention The anisotropic conductive film according to the present invention is formed by applying metal plating to the surface of particles to be plated obtained by a specific method (a)
Using a conductive resin composition in which a conductive filler is dispersed in (b) a base resin and optionally (c) a diluent, the conductive material contained in the composition is applied onto a substrate. It is characterized by being formed with a film thickness that is approximately equal to the particle size of the filler. A method of manufacturing the (a) conductive filler to which this plating is applied will be explained.

The particles to be plated used in the present invention are spherical and have a sharp particle size distribution. To explain the manufacturing method, first, the particles are dispersed in water using metal oxides or metal hydroxides as seeds. Prepare an alcoholic dispersion. The seeds dispersed in the water-alcohol dispersion are metal oxides or metal hydroxides, but depending on the case, other particles with uniform particle sizes can also be used. The particles used as seeds as described above are 0.
It is preferable that the particle size is as uniform as possible, on the order of 0.05 to 9.0 μm.

To obtain such a water-alcohol dispersion in which seeds are dispersed, the seeds may be added to a water-alcohol mixed solution, or the seeds may be generated in the water-alcohol dispersion. Among these, a water-alcohol dispersion in which seeds obtained by hydrolyzing a metal alkoxide in a water-alcohol dispersion are dispersed is preferably used.

Seed generation methods include, for example, powder and powder metallurgy.

(4), 19-24 (1976) or Journal
alcolloid ＆Interface Sci
, 26.62-69 (1968).

In this way, a water-alcohol dispersion in which metal oxide particles or metal hydroxide particles are dispersed as seeds is obtained. is added to form a stabilized dispersion (hereinafter sometimes referred to as heel sol). If the dispersion is not stabilized by adding an alkali, the seed particles may aggregate and precipitate. If the seeds aggregate with each other, the metal Alfuki 91 decomposition products will also adhere to the joints (necks) of the aggregated particles, making it impossible to obtain particles with a uniform particle size.

The alkali added to stabilize the dispersion is as follows:
Ammonia gas, aqueous ammonia, alkali metal hydroxides such as sodium hydroxide, quaternary ammonium salts, amines, etc. may be used alone or in combination.

The alcohol concentration in the water-alcohol dispersion in which the seeds are dispersed is preferably 35 to 97% by weight.

The alcohols used here include methanol, ethanol, n-propanol, isopropanol, n-propanol,
Lower alcohols such as butyl alcohol and isobutyl alcohol are used. It is also possible to use a mixed solvent of these lower alcohols.

In addition to water and alcohol, other organic solvents can also be used as the water-alcohol dispersion. As such an organic solvent, one is used that has good compatibility with water and alcohol, and also has good compatibility with metal alkoxide.

Specifically, such organic solvents include polyhydric alcohols such as ethylene glycol, propylene glycol, and hexylene glycol, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether,
Ethers such as ethylene glycol monomethyl ether, esters such as ethyl acetate, ketones such as acetone, penzoles such as toluene and xylene, dimethylformamide, N-methyl-2-pyrrolidone and its derivatives, etc. are used alone or in combination. It will be done.

The concentration of the seeds in the water-alcohol dispersion is preferably 0.05 to 20.0% by weight in terms of oxide concentration. If the oxide concentration of the seeds is less than 0.05% by weight, new seeds may be generated in the subsequent step of attaching metal alkoxide decomposition products to the seeds, and the particle size of the resulting particles This is not preferable because the distribution becomes broad.

On the other hand, if the oxide concentration of the seeds exceeds 20.0% by weight, it is not preferable because the particles will coagulate during the process of attaching the metal Alfuki 91 decomposition product to the seeds.

Next, while keeping the heel sol alkaline, a metal alkoxide is added to the heel sol, which is a water-alcohol dispersion in which the alkali-stabilized seeds obtained as described above are dispersed, for hydrolysis. Seed particles are grown by depositing metal alkoxide decomposition products on the seeds.

As the metal alkoxide, any metal alkoxide can be used as long as it can form an alkoxide. The number of carbon atoms in the ester group forming the alkoxide is preferably about 1 to 7, preferably about 1 to 4. Such metal alkoxides may be used after being diluted with alcohol or the like, or may be used as a undiluted solution.

When adding the metal alkoxide to the dispersion, it is preferable to add a water-alcohol mixed solution together with the metal alkoxide. It is preferable that these metal alkoxides and water-alcohol mixed solution are gradually added to the heel sol.

When a metal alkoxide is added to Healsol, the metal alkoxide begins to hydrolyze, and at this time, the volume of the solution rapidly decreases.
) H changes. If the heel sol liquid is no longer alkaline as described above, seeds may aggregate or new seeds may be generated, which is not preferable because the particle size distribution of the final particles becomes broad. Therefore, when adding the metal alkoxide, the heel sol is kept alkaline. pH of Healsol
is preferably 10 to 13. In order to keep the heel sol alkaline, it is sufficient to add alkali to the heel sol. Specifically, as the alkali added,
Ammonia gas, aqueous ammonia, amines, alkali metal hydroxides, and quaternary ammonium salts may be used alone or in combination.

The temperature at which the metal alkoxide is hydrolyzed is not particularly limited, but when a temperature higher than the boiling point of water or alcohol is used, it is preferable to pressurize the solution so that it can maintain a liquid phase. However, carrying out the decomposition reaction of the metal alkoxide above the critical temperature of alcohol or the like present in the reaction system may change the composition ratio in the liquid phase, so it is preferable to carry out the decomposition reaction below the critical temperature.

Seed particles are grown by depositing the metal alkoxide decomposition product on the seeds as described above, but the concentration of the grown particles in the reaction system is 0.05 to 2.0 in terms of oxide concentration.
It is preferably 0.0% by weight, more preferably 0.05 to 15.0% by weight. Particle concentration is 0.05% by weight
If the concentration is less than 20% by weight, productivity will be poor and a large amount of alcohol will be required, resulting in poor economic efficiency. On the other hand, if the concentration of particles exceeds 20% by weight, aggregation will occur between particles during seed particle growth, resulting in poor productivity of the resulting particles. This is not preferable because the particle size distribution becomes broad.

When depositing the metal alkoxide decomposition product on the seeds, the alcohol concentration in the reaction system is preferably 35 to 97% by weight.

If the alcohol concentration is less than 35% by weight, it will have poor compatibility with the metal alkoxide to be added and will form an emulsion.
This is undesirable because the seeds may aggregate or an amorphous product that is not spherical may be obtained.
If it exceeds % by weight, the rate of hydrolysis of the metal alkoxide becomes too slow, which is not preferable. The alcohol concentration in the reaction system can be adjusted by adding water and alcohol together with the metal alkoxide into the reaction system,
The ratio of alcohol to the alkoxide is 0.4 to 1.1 moles, and the ratio of water to the alkoxide is 2.0 to 24 moles.
．． It is preferable that it is added in a proportion of 0 mol.

The particles thus obtained and dispersed in the water-alcohol dispersion medium are spherical and have a particle diameter of 0.1 to 10 μm.
It has a sharp particle size distribution (σ≦0.5), and is monodispersed without agglomeration in the dispersion medium. Further, according to the method for producing particles as described above, the particle diameter of the obtained particles can be controlled to any value within the range of 0.1 to 10 μm. Furthermore, the concentration of particles based on oxides is 0.0
It is 5 to 20.0% by weight, which can be significantly higher than in conventional methods of producing particles using metal alkoxides. Therefore, it is possible to increase the production efficiency of the particles and also to reduce the production cost.

In order to greatly increase the stability of the particles monodispersed in the dispersion obtained in this way, if a stabilizer such as an alkali is added to the dispersion obtained and aging is performed, it is possible to maintain the stability for a long period of time. Particles in the dispersion do not aggregate. Moreover, the alcohol in the dispersion can also be replaced with another organic solvent.

By drying such a dispersion, particles with good dispersibility can be obtained, which are used as particles to be plated in the present invention.

In some cases, when the particles obtained as described above are heat-treated at a temperature of 250°C or higher, preferably 250 to 1000°C, in an air atmosphere or an inert gas atmosphere, white particles become blackish. Although it varies, the black-colored particles with good dispersibility obtained in this way can also be used as particles to be plated.

It is thought that the reason why white particles change to black particles by heat treatment at a temperature of 250° C. or higher is as follows. In other words, organic substances such as unreacted metal alkoxides are present inside the particles before heat treatment, and when these unreacted organic substances such as metal alkoxides are heated to a temperature of 250°C or higher and decomposed or carbonized, , the particles probably turn black.

As mentioned above, the heat treatment temperature for the white particles is 250°C or higher, preferably 250 to 1000°C. However, if the heat treatment temperature is lower than 250°C, the white particles will be blackened; On the other hand, if the heat treatment temperature exceeds 1000° C., sintering between particles may occur, which is not preferable.

Generally, when the particle size of white particles is small, 2
Blackening occurs by heat treatment at a relatively low temperature in the temperature range of 50 to 1000°C, but as the particle size increases, heat treatment at a relatively high temperature is required.

Furthermore, in the present invention, when adding the metal alkoxide to the water-alcohol dispersion in which the seeds are dispersed, an organic substance that is dissolved or dispersed in the water-alcohol dispersion is added, and this organic substance is By depositing the metal alkoxide decomposition product on the seed and then heat-treating the resulting particles to a temperature of 250° C. or higher, the color tone of the resulting black particles can be roughly blackened. Alternatively, before heat-treating the white particles obtained by drying the dispersion, the white particles are impregnated with a solution of an organic substance, and the organic substance is introduced into the pores of the particles (after heating for 4 hours). By doing so, the color tone of the obtained black particles can be further blackened.

The black particles obtained as described above are JIS Z
Color tristimulus value X measured in accordance with 8701-82
, Y, and Z, which corresponds to the brightness of the color displayed, usually has a value of 10% or less, and has excellent blackness.

The particles to be plated obtained by the above production method have a particle size of 0.1 to 10μ and a sharp particle size distribution (σ≦0.5), so the particles can be obtained by applying metal plating to the surface of the particles. The conductive filler has good dispersibility when added to conductive polymers, conductive rubber, conductive plus deck, conductive paints, conductive adhesives, etc., and has excellent performance as a conductive filler. Are better.

In order to apply metal plating to the surfaces of the particles to be plated obtained as described above, conventionally known methods such as chemical plating can be employed. The thickness of the metal plating layer is 100 Å
It is preferable to stay above.

If the thickness of the metal plating layer is less than 100, the conductivity of the resulting conductive filler becomes low, which is not preferable.

Specifically, platinum, gold, silver, copper, nickel, palladium, etc. are used as the metal for metal plating. It is also possible to sequentially plate different types of metals to form a multilayer metal plating layer.

An example of a specific method for applying metal plating to the surface of particles to be plated by chemical plating is to sufficiently disperse the particles in an aqueous ammoniacal nitrate metal salt solution, and then coat the particles with a reducing organic compound such as formalin. Metal plating can be formed on the surfaces of the particles by reducing and depositing the metal uniformly on the surfaces of the particles. At this time, by appropriately adjusting the ratio between the amount of metal to be precipitated and the amount of particles without metal plating, materials having various volume resistivities can be obtained.

When it is desired to improve the adhesion of metal plating, it is possible to simultaneously add a small amount of an acidic metal salt of the plating metal that can be dispersed or dissolved in the water-alcohol mixture when adding the metal alkoxide in the above method for producing particles to be plated. good. Alternatively, the obtained particles for plating may be impregnated with an acidic metal salt.

By dispersing (a) a conductive filler having a metal plating layer on the surface of the particles to be plated thus obtained, in (b) a base resin and optionally (c) a diluent. , the conductive resin composition used in the present invention is obtained.

Specific examples of the base resin (b) used in the present invention include acrylic resins such as methacrylic resins, polyurethane resins, urea resins, amine resins such as melamine resins, polyamide resins, polyimide resins, and polyamide resins. Polyester resins such as imide resins, polyurethane resins, alkyd resins, chlorinated resins such as epoxy resins and chlorinated polyether resins, polyolefin resins such as polyethylene resins and polypropylene resins, polycarbonate resins, silicone resins, polystyrene resin,
Polyurethane resins such as ABS resin, polyamine sulfone resin, polyether sulfone resin, polyphenylene sulfone resin, vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, polyvinyl alcohol resin, polyvinyl carbazole resin, butyral resin, etc. resin, fluorine resin, polyphenylene oxide resin, polypyrrole resin, polyphalaphenylene resin,
Ultraviolet curing resin, cellulose derivatives, etc. are used. Also, mixtures of the above resins or polymers or copolymers of the above resins, such as styrene-butadiene rubber, butadiene rubber, isoprene rubber, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, acrylonitrile-butadiene copolymer, chloroprene Rubber, butyl rubber, urethane rubber, silicone rubber, polysulfide rubber, fluororubber, tetrafluoroethylene-propylene rubber, acrylic rubber, chlorosulfonated polyethylene, shrimp chlorohydrin rubber, propylene oxyside rubber, ethylene-vinyl acetate rubber, ethylene-acrylic Rubber, liquid rubber, syndiotactic-1,2-polybutadiene rubber, norbornene rubber, thermoplastic elastomer, etc.
It can be used as a species or in combination of two or more species.

The mixing ratio of (a) conductive filler and (b) base resin is such that (a) conductive filler is 0% relative to the total weight of both.
．． 0'1% by weight - 20. 0% by weight, preferably from 0.1% to 15. Preferably, the amount is 0% by weight. (a
) If the content of the conductive filler is less than 0.01% by weight, the conductivity of the resulting conductive resin composition will deteriorate, which is not preferable.
On the other hand, if it exceeds 20.0% by weight, the adhesion between the conductive resin composition and the base material will deteriorate, which is not preferable. In addition, in applications that require high transparency, (a) the amount of conductive filler can be reduced to 0.
．． The content is preferably 1% to 5.0% by weight. (a
) If the amount of the conductive filler exceeds 5.0% by weight, the resulting conductive resin composition will have poor transparency.

In the conductive resin composition used in the present invention, each of the above-mentioned components is dissolved or dispersed in (c) a diluent, if necessary. Any diluent (c) can be used as long as it can dissolve or dilute the base resin (b). Specifically, methanol, ethanol, n-propertool, i-propertool, n-butanol, i-butanol, diacetone alcohol, cyclohexanol,
Alcohols such as ethylene glycol, propylene glycol, hexylene glycol, ketones such as acetone, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, holon, isophorone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, calpitol, methyl calpitol, butyl Ethers such as carpitol and dioxane, esters such as ethyl acetate, petroleum naphthas such as hexane and cyclohexane, pensoles such as toluene, xylene and solvent naphtha, N-methyl-2-pyrrolidone and its derivatives, etc. alone or Used in combination. Such (c) diluent is used in an amount to provide a viscosity that is easy to process for various applications. Furthermore, when (b) a water-soluble resin is used as the base resin, water can also be used as the diluent (c).

In order to produce the conductive resin composition according to the present invention, (a) the conductive filler and (b) the base resin as described above,
If necessary, it may be added to (c) diluent and mixed uniformly. If necessary, in order to improve the dispersibility of the conductive filler H and prevent agglomeration, anionic, nonionic, cationic surfactants, silane-based, titanium-based, aluminum-based, zirconium-based, etc. A magnesium-based coupling agent can be added.

The conductive resin composition obtained in this manner is coated onto a substrate to a thickness that is approximately equal to the particle size of the conductive filler (a) contained in the composition to form a film. When formed into
An anisotropically conductive film according to the present invention is obtained.

At this time, the conductive resin composition is impregnated with the diluent (c) as described above to have a viscosity that makes it easy to coat, and the composition is applied to the substrate by a conventionally known coating method such as a wire bar method or a screen printing method. It is preferable to form the anisotropically conductive film according to the present invention by coating on top.

A schematic diagram of the anisotropically conductive film according to the present invention is shown in FIG.
For example, an anisotropic conductive film 2 is provided on a base material 1,
This anisotropically conductive film 2 consists of (a) a conductive filler and (b) a base resin. The thickness d of this anisotropic conductive film
is formed to have approximately the same particle size as the conductive filler (a).

Such an anisotropic conductive film 2 has high conductivity in the thickness direction (vertical direction) because current flows through (a) the conductive filler, while it has high conductivity in the length direction (horizontal direction). is small, and the conductivity differs depending on the direction.

If a conductive film such as indium-tin oxide is interposed between the substrate 1 and the anisotropically conductive film 2, an anisotropically conductive electrode can be obtained by this conductive film and the anisotropically conductive film. It will be done.

Effects of the Invention In the anisotropic conductive film according to the present invention, the conductive filler contained in the conductive resin composition in order to impart conductivity to the film has a small difference in specific gravity from the base resin and has low dispersibility. in good condition,
Moreover, it is inexpensive.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A mixture of 4,879 g of ethyl alcohol and 389 g of water was kept at 35°C without stirring, and 71 g of ammonia gas was added to the mixture. i was dissolved. 17.4 g of 28% ethyl silicate was added to this mixed solution, and stirring was continued for 2 hours to obtain a cloudy white liquid in which seed particles equivalent to 0.5% by weight in terms of SiO2 were dispersed.

Immediately, 3.3 g of an aqueous solution in which NaOH0,039 was dissolved was added to this cloudy liquid, and 1 q of heel sol (A>) in which seed particles were dispersed in a water-alcohol dispersion was prepared.

9'l of the obtained heel sol (A>) was heated at 35° while stirring.
455 g of ethyl alcohol and 886 g of water while controlling the pH to 11.5 with ammonia gas.
and 28% ethyl silicate 5709 were simultaneously added gradually over 19 hours. After adding the entire amount, an aqueous solution 1039 in which 1 g of NaOH was dissolved was added to the liquid, and this was heated to 70°C and held for 2 hours to obtain a dispersion (I>. This dispersion (I>) was dried at 200°C. Powder particles (■) were obtained.The powder particles (■) had a particle size of 2.0 μm and σ-0,
It was 1 μm.

On the other hand, add 28 d of 24 wt% ammonia aqueous solution to 800 g of water.
In the diluted solution, 29.29 g of silver nitrate was dissolved. Powder particles (1) 209 were added to water 6009 under stirring, and the ammoniacal silver nitrate aqueous solution was added to thoroughly disperse the mixture. While stirring this mixture, add 30% formalin 32.
A solution prepared by diluting 8d with 180 g of water was dropped onto the surface of the powder particles, and the surfaces of the powder particles were plated with silver. Then, after filtering and washing, it was dried at 90°C to obtain a conductive filler. The obtained conductive filler is
The specific gravity was 3.12, the thickness of the plating film was 400 mm, and the specific resistance was 3×10 −3 Ω·cm.

1.0 g of the obtained conductive filler, 75 y of methyl ethyl ketone/toluene (weighted 1/1), and epoxy resin (
Trade name: Epicoat, manufactured by Yuka Shell Co., Ltd.>49g was sufficiently dispersed using a homogenizer to obtain a conductive resin composition. This paint was applied to an ITO glass plate using a wire bar so that the film thickness after curing would be 1.9 μm, and was cured at 160° C. for 5 minutes to form an anisotropically conductive film. ITO on which this film was formed
The resistance of the glass plate was measured using an electrode cell (Y)-(manufactured by P).

The longitudinal resistance of the obtained anisotropic conductive film was 2 × 10 Ω.
, the lateral resistance was 5×10 14 Ω.

Example 2 14 g of the dispersion obtained in Example 1 (I>1") was stirred for 3
While keeping the temperature at 5°C, add 63 g of ethyl alcohol and 51 g of water, and while controlling the F Added. After adding the entire amount, add NaOH to the solution.
Add an aqueous solution 657 in which 0.7 g of
Heel sol (B) was obtained by heating and holding for 2 hours.

This heal sol (B) 94. ．． 6y was maintained at 65°C with stirring, 116q of ethyl alcohol and 95g of water were added, and while controlling l)H to 11.5 with ammonia gas,
A mixture of 307 g of ethyl alcohol and 438 g of water and 207 g of 28% ethyl silicate were simultaneously added gradually over 19 hours. After adding the entire amount, NaOHO,
An aqueous solution 659 in which i was dissolved was added, and the mixture was heated to 70°C and held for 2 hours to obtain a dispersion (II).

1,126 g of the obtained dispersion (II) was kept at 65°C with stirring, and 1,558 g of ethyl alcohol was added to the dispersion (II).
Add 127 g of water and reduce t)H to 11.5 with ammonia gas.
A mixture of 1643 ethyl alcohol and 275 q of water and 28% ethyl silicate 1
56 g were simultaneously added slowly over 19 hours. After adding the entire amount, 65 g of an aqueous solution with 0.7 g of NaOH dissolved in the liquid.
was added and heated to 70°C and held for 2 hours to obtain heelsol (c).

This Healsol (c) 1321 was kept at 65 ° C while stirring, 185 g of ethyl alcohol and 1519 of water were added, and while controlling I)H to 11.5 with ammonia gas,
A mixed solution of 939 g of ethyl alcohol and 150 g of water and 82 g of 28% ethyl silicate were simultaneously added gradually over 19 hours.

After adding the entire amount, 58 g of an aqueous solution in which NaO80,6SF was dissolved was added, and the mixture was heated to 70°C and held for 2 hours to obtain a dispersion (I). This dispersion (III) was added to
It was dried at ℃ to obtain powder particles (■). The powder particles (1) had a particle size of 7.9 μm and a σ-0.2 μm tile.

On the other hand, add 28 Inl of 24% by weight ammonia aqueous solution to water ao
Copper nitrate (38.09 g) was dissolved in the solution diluted with O.G. 15 g of powder particles (1) were added to Water 6009 under stirring, and the ammoniacal copper nitrate aqueous solution was added to thoroughly disperse the mixture. While stirring this mixture, add 30% formalin 3
2.8rId! A solution prepared by diluting the powder with 180 g of water was dropped onto the powder particles, and the surfaces of the powder particles were plated with copper. Then, after filtration and washing 9
A conductive filler was obtained by drying at 0°C. The obtained conductive filler has a specific gravity of 2.40, and the thickness of the plating film is 40.
There were 0 people, and the specific resistance was 5×10'Ω·ctn.

4.0 g of the obtained conductive filler, 1259 methyl isobutyl ketone/ethyl acetate/ethylene glycol monobutyl ether (weight ratio 4/3/3), and acrylic resin (
A conductive resin composition was obtained by thoroughly dispersing 96 g of Niacrydec A307 (trade name, manufactured by Dainippon Ink and Chemicals Co., Ltd.) using a triple roll. This coating material was screen printed on a NESA film so that the film thickness after curing would be 7.7 μm, and was cured at 110° C. for 10 minutes to obtain an anisotropically conductive film.

The resistance of the NESA film on which this film was formed was measured using an electrode cell (manufactured by YHP). The longitudinal resistance of the obtained anisotropic conductive film was 4X103Ω, and the horizontal resistance was 7X1.
It was 0.015Ω.

Example 3 The powder particles obtained in Example 1 were heated to 35% in an air atmosphere.
Heat treatment was performed at 0° C. for 3 hours to obtain black particles.

The obtained black particles had a Y value of 7.0% as defined by JIS Z 8701.

On the other hand, add 28ml of 24% by weight ammonia aqueous solution to 800ml of water.
19.4 g of copper nitrate was dissolved in the diluted solution. Black particles 209 were added to water 6007 under stirring, and the ammoniacal copper nitrate aqueous solution was roughly added to sufficiently disperse the particles. While stirring this mixture, 30% formalin 32
．． 8mf! A solution obtained by diluting the powder with water 1809 was added dropwise, and the surfaces of the powder particles were plated with copper. Then, after filtration and washing, 90°C
was dried to obtain copper-plated particles. The thickness of the plating film of the copper plating particles was 200 mm.

Next, 18.0 g of silver nitrate was dissolved in a solution prepared by diluting 28 d of a 24% ammonia aqueous solution with 800 g of water.

The copper plating particles were added to water 6009 under stirring, and the ammoniacal silver nitrate aqueous solution was further added to sufficiently disperse the particles. While stirring this mixed solution, a solution prepared by diluting 32.8 d of 30% formalin with 180 9 d of water was dropped, and the surface of the copper plating particles was plated with silver. Then, after filtration and washing 9
A conductive filler was obtained by drying at 0°C. This conductive filler has a specific gravity of 3.03, and the thickness of the silver plating film is 200.
It was a human being, and its specific resistance was 1×10 −3 Ω·cm.

0.2 g of the obtained conductive filler and cyclohexanone/
Ethyl acetate/ethylene glycol monoethyl ether (
A conductive resin composition was obtained by sufficiently dispersing 909 (weight ratio 1/1/1) and epoxy resin (trade name: Araldite, manufactured by Ciba Geigy) 49.857 using a high-speed disperser. This paint was applied to an aluminum plate with a film thickness of 1.9 μm after curing.
The film was coated with a wire bar so as to have a thickness of m, and was cured at 180° C. for 5 minutes to obtain an anisotropic conductive film. The resistance of the aluminum plate on which this film was formed was measured using an electrode cell (manufactured by YHP). The longitudinal resistance of the anisotropic conductive film was 1×10 −3 Ω, and the lateral resistance was 1×10 16 Ω.

Example 4 A mixture of 487 g of ethyl alcohol, 389 g of water, and 0.02!7 nickel nitrate hexahydrate was heated at 35°C while stirring.
71.7 g of ammonia gas was dissolved in this mixed solution. Add 17.4% of 28% ethyl silicate to this mixture.
! ? was added, followed by continued stirring for 2 hours (to obtain a white cloudy liquid in which seed particles equivalent to 0.5% by weight in terms of SiO2 were dispersed. Na1l-(0,03
Add 3.33 g of an aqueous solution in which the seed particles are dissolved in water.
A heelsol (D) dispersed in an alcohol dispersion was obtained. Of the obtained heel sol (D), 973 was stirred for 35 minutes.
While keeping the temperature at °C and controlling l)H to 11.5 with ammonia gas, add 455 g of ethyl alcohol and 28%
Mixed liquid with ethyl silicate 5707 and 886 g of water
and 0.63 g of nickel nitrate anhydrous salt at the same time.
It was added gradually over 9 hours. After adding the entire amount, Na
Add aqueous solution 1039 in which 0HIJ is dissolved, and add this to 7
It was heated to 0°C and held for 2 hours to obtain a dispersion (IV). 114q of the obtained dispersion (IV) was heated at 35°C with stirring.
63g of ethyl alcohol and 51g of water were added while controlling the pH to 11.5 with ammonia gas.
Ethyl alcohol 6383 and 28% ethyl silicate 3
A mixed solution of 25 g of water and a mixed solution of 8149 water and 0.3 CI of nickel nitrate hexahydrate were simultaneously added gradually over 19 hours. After adding the entire amount, an aqueous solution 653 in which NaOH0.73 was dissolved was added, and this was heated to 70° C. and held for 2 hours to obtain a heel sol (E). Of the obtained heel sol (E), 94.69 was kept at 65°C with stirring, 116 J of ethyl alcohol and 959 of water were added, and while controlling the height of heel 1 to 11.5 with ammonia gas, 3073 of ethyl alcohol and 28% ethyl were added. A mixture of 207 g of silicate, 4387 water and 0.23 nickel nitrate anhydrous salt
At the same time, the mixture with g was gradually added over 19 hours.

After adding the entire amount, 65 g of an aqueous solution in which 0.7s of NaOH was dissolved in the solution was added, and this was heated to 70° C. and held for 2 hours to obtain a dispersion (V).

11269 of the obtained dispersion (V) was stirred at 65°
C, add ethyl alcohol 1553 and water 127 g, and while controlling I)H to 11.5 with ammonia gas, a mixed solution of ethyl alcohol 164 g and 28% ethyl silicate 156 g, water 2758 and nickel nitrate hexahydrate. At the same time, a mixture of 0.17 g and 0.17 g was gradually added over 19 hours. After adding the entire amount, NaOH0,
An aqueous solution 653 in which 73 was dissolved was added, and this was heated to 70° C. and held for 2 hours to obtain Heal Sol (F). Of the obtained Healsol (F), 13249 was kept at 65 °C with stirring, 185 g of ethyl alcohol and 1517 of water were added, and while controlling l-1 to 11.5 with ammonia gas, 93 g of ethyl alcohol and 28% A mixture of 82 g of ethyl silicate and a mixture of 1,509 g of water and 0.099 g of nickel nitrate anhydrous salt were simultaneously added gradually over 19 hours. After adding the entire amount, an aqueous solution 583 in which NaOH0,69 was dissolved was added, and this was heated to 70°C and held for 2 hours to obtain a dispersion <vr>. This dispersion (
vI) was dried at 200°C to obtain powder particles (■). This powder particle ■ has a particle diameter of 8.011 m, and 0'' = 0.2 μ7
It was 77.

On the other hand, add 28 d of 24 wt% ammonia aqueous solution to 800 g of water.
Nickel nitrate anhydrous salt 41,i was dissolved in the diluted solution. 20g of powder particles (1) were added to 60CH7 of water under stirring, and the ammoniacal nickel nitrate aqueous solution was added to thoroughly disperse the mixture. While stirring this mixture,
A solution obtained by diluting 32.8 ml of % formalin with 180 y of water was dropped, and the surfaces of the powder particles were plated with nickel. Next, the particles were filtered, washed, and dried at 90°C to obtain nickel-plated particles. The thickness of the plating film of these nickel-plated particles was 200 mm.

Next, add 28 d of 24 wt% ammonia aqueous solution to 800 g of water.
48.09 g of potassium gold cyanide was dissolved in the diluted solution. The nickel plating particles were added to water 6009 under stirring, and the ammoniacal gold potassium cyanide aqueous solution was added to the colander to thoroughly disperse the particles. While stirring this liquid mixture, a solution prepared by diluting 32.8 parts of 30% formalin with 180 J of water was dropped to plate the surfaces of the nickel-plated particles with gold. Then, after filtering and washing, it was dried at 90°C to obtain a conductive filler. This conductive filler had a specific gravity of 4.43, a thickness of the gold plating film of 2000 μm, and a specific resistance of 2×10′Ω·cm.

The obtained conductive filler 7.09, 100 y of water, and water-soluble vinyl resin (trade name: Vinizol, manufactured by Daido Kasei Kogyo Co., Ltd.) 403 were sufficiently dispersed with a homogenizer to form a conductive resin composition. Obtained. This paint was applied to an iron plate with a wire bar so that the film thickness after curing was 7.9 μm.
It was cured at 0°C for 30 minutes to obtain an anisotropically conductive film. The resistance of the iron plate on which this film was formed was measured using an electrode cell (manufactured by YHP). The longitudinal resistance of the anisotropic conductive film is 3×10 Ω,
The lateral resistance was 2×10 14 Ω.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an anisotropically conductive film obtained by the present invention. 1...Substrate 2...Anisotropic conductive film a...
・Conductive filler b...Base resin agent Patent attorney Shunichi Suzumoto Figure 1

Claims (1)

[Scope of Claims] 1) A metal alkoxide is added to a water-alcohol dispersion in which metal oxides or metal hydroxides are dispersed as seeds and hydrolyzed while keeping the dispersion alkaline. (a) A conductive filler obtained by applying metal plating to the surface of particles obtained by adhering a metal alkoxide decomposition product thereon, or black particles obtained by heat-treating the particles at 250° C. or higher. (b) An anisotropic conductive film dispersed in a base resin, wherein the thickness of the conductive thin film is approximately equal to the particle size of the conductive filler (a). conductive film. 2) A metal alkoxide is added to a water-alcohol dispersion in which a metal oxide or metal hydroxide is dispersed as a seed, while keeping the dispersion alkaline, and hydrolyzed to produce metal alkoxide decomposition on the seed. Particles obtained by attaching things,
Alternatively, a conductive resin composition in which (a) a conductive filler is dispersed in (b) a base resin, which is obtained by applying metal plating to the surface of black particles obtained by heat-treating the particles at 250° C. or higher. (a) contained in the composition on a substrate.
A method for producing an anisotropically conductive film, characterized in that the film is formed to have a thickness approximately equal to the particle size of a conductive filler. 3) The method according to claim 2, wherein the conductive resin composition further contains (c) a diluent.