JP2002080773A - Electroconductive coating and electroconductive laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electroconductive coating good in electrical conductivity, hard to cause loss of the electroconductive material on a substrate and change in electrical resistance even if the substrate undergoes a flexural deformation or the like, and capable of forming an electroconductive layer highly adhesive to a substrate. SOLUTION: This electroconductive coating comprises a base polymer, an electroconductive material and water or an organic solvent; wherein the base polymer is characterized by being obtained by polymerizing, in an aqueous medium, (B) 100 pts.wt. of a monomer mixture comprising a diene-based monomer and an ethylenically unsaturated monomer in the presence of (A) 5-100 pts.wt. of a resin obtained by at least partially neutralizing a polymer having ethylenically unsaturated carboxylic acid-derived monomer unit and an acid value of 50-300.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive paint and a conductive laminate obtained by applying the same to a substrate, and more particularly to a conductive paint having a specific base polymer and excellent adhesion to a substrate. It relates to a good conductive paint and a conductive laminate.

[0002]

2. Description of the Related Art Conductive paints are usually obtained by dissolving or dispersing a base polymer in a liquid medium and adding a conductive material to the solution. A conductive layer is formed on the surface of the substrate by applying a conductive paint to the surface of the substrate and volatilizing the liquid medium to form an electromagnetic wave shield, a heating element, an antistatic coating, and electrical connection of various electric and electronic parts. (JP-A-5-171072, JP-A-6-271793, JP-A-8-41388, JP-A-11-24)
No. 6758). There are two types of conductive paints: organic solvent-based paints and water-based paints. For organic solvent-based paints, base polymers such as polyolefin, polyester, polyamide, polyacrylate, epoxy resin,
Known are those dissolved or dispersed in organic solvents such as toluene, xylene, ethyl acetate and butyl acetate. Organic solvent-based paints are frequently used because of their high drying speed after coating and good coating productivity. However, in addition to the problem of insufficient adhesiveness to the substrate, they also evaporate the organic solvent, thus protecting the environment. In addition, there is a restriction that a facility for collecting and removing organic solvents is required.

As a solution to these problems, an aqueous conductive paint using water as a liquid medium has been proposed (Japanese Patent Laid-Open No. 5-1).
No. 25301, JP-A-6-179839, etc.). These include a mixture of a conductive material and an aqueous base polymer solution, or a mixture of a conductive material and a polymer latex produced by an emulsion polymerization method, to which a carboxymethyl cellulose as a thickener is added. The method using the aqueous base polymer solution has a problem that the resistance value of the conductive layer varies depending on the atmosphere used because the base polymer easily absorbs moisture.On the other hand, the method using the polymer latex is obtained. There has been a problem that the adhesion of the conductive layer to the substrate is insufficient.

[0004] Conductive paints are used by applying them to various forms and types of substrates. When the substrates are sheets or films, the substrates are repeatedly bent after the conductive layer is formed. Sometimes used while receiving. At this time, there is a problem that the conductive layer is separated from the base due to the deformation of the base, or the conductive material is dropped from the conductive layer to lower the conductivity. In addition, there is a problem that a crack is generated inside the conductive layer due to the deformation of the base and the resistance value changes. In particular,
Water-soluble polymer has high Tg due to its high polarity,
The conductive layer obtained by drying has insufficient flexibility, and the conductive material tends to fall off due to deformation of the base. For this reason, a base polymer having good adhesion to a substrate is required.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a conductive material having a good conductivity, even if the substrate is deformed by bending or the like, so that the conductive material does not easily fall off or change in the resistance value. It is an object of the present invention to provide a conductive paint for forming a conductive layer having a large thickness and a laminate using the same.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that the adhesion strength between the conductive layer and the substrate is insufficient, that the conductive layer falls off after bending of the conductive film, and that the resistance of the conductive layer is reduced. Focusing on the cause of the increase in value relates to the emulsifier used during the polymerization of the base polymer, found that these can be solved by using a base polymer by a specific production method, and based on this finding, completes the present invention. Reached. Thus, according to the present invention, (1) a conductive paint having a base polymer, a conductive material, and water or an organic solvent, wherein the base polymer contains a monomer unit derived from an ethylenically unsaturated carboxylic acid. Has an acid value of 50
A diene monomer and an ethylenically unsaturated monomer in an aqueous medium in the presence of 5 to 100 parts by weight of a resin (A) obtained by at least partially neutralizing a polymer of Conductive paint characterized by being obtained by polymerizing 100 parts by weight of a monomer mixture (B) containing the same, (2) a conductive laminate having a coating comprising a base polymer and a conductive material, and a substrate Wherein the base polymer has monomer units derived from an ethylenically unsaturated carboxylic acid, and is obtained by at least partially neutralizing a polymer having an acid value of 50 to 300 (A ) A polymer obtained by polymerizing 100 parts by weight of a monomer mixture (B) containing a diene monomer and an ethylenically unsaturated monomer in an aqueous medium in the presence of 5 to 100 parts by weight. A conductive laminate characterized by the fact that ( ) Has a monomer unit derived from an ethylenically unsaturated carboxylic acid, a resin acid value is obtained by at least partially neutralizing the polymer is 50 to 300 (A) 5
Base for conductive paint obtained by polymerizing 100 parts by weight of a monomer mixture (B) containing a diene monomer and an ethylenically unsaturated monomer in an aqueous medium in the presence of from 100 to 100 parts by weight Polymers are provided.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The base polymer used for the conductive coating composition of the present invention contains at least partially a polymer having a monomer unit derived from an ethylenically unsaturated carboxylic acid and having an acid value of 50 to 300. It is a polymer obtained by polymerizing a diene-based monomer and an ethylenically unsaturated monomer using the resin (A) obtained by summing the resin (A) as a dispersion stabilizer. The resin (A) is obtained by polymerizing an ethylenically unsaturated carboxylic acid and a monomer (co-monomer) copolymerizable therewith, and then preparing a carboxyl group having an acid value of 50 to 300 in the obtained polymer. Obtained by equivalent or partial neutralization of the group. Examples of the ethylenically unsaturated carboxylic acid include carboxyl group-containing ethylenically unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, and itaconic acid; monooctyl maleate, monobutyl maleate, Examples include ethylenically unsaturated dicarboxylic acid monoesters such as monooctyl itaconate.

Examples of the ethylenically unsaturated carboxylic acid comonomer include vinyl aromatic monomers such as styrene, α-methylstyrene, vinyltoluene, pt-butylstyrene, and chlorostyrene; ) Methyl acrylate (meaning methyl acrylate and / or methyl methacrylate; the same applies hereinafter), ethyl (meth) acrylate,
Propyl (meth) acrylate, 2- (meth) acrylic acid
(Meth) acrylic ester monomers such as ethylhexyl and hydroxypropyl (meth) acrylate; (meth) acrylamide monomers such as (meth) acrylamide, N-methylol (meth) acrylamide and N-butoxymethyl (meth) acrylamide Monomers; glycidyl group-containing monomers such as glycidyl (meth) acrylate and allyl glycidyl ether; nitrile group-containing monomers such as (meth) acrylonitrile, fumaronitrile, α-chloroacrylonitrile, and α-cyanoethylacrylonitrile;
Allylsulfonic acid dichloride and the like can be mentioned.

The polymer before neutralization of the resin (A) can be obtained by conventionally known solution polymerization or emulsion polymerization. As the emulsifier used in the case of the emulsion polymerization, an anionic emulsifier, a nonionic emulsifier and a cationic emulsifier which are usually used for the emulsion polymerization can be used. In particular, one or more polymerizable carbon-carbon in their molecule can be used. It is preferable to use a polymerizable emulsifier having an unsaturated bond. Specific examples of the polymerizable emulsifier include ammonium polyoxyethylene nonylpropenylphenyl ether sulfate, sodium propenyl-2-ethylhexylbenzenesulfosuccinate, sodium sulfate ester of polyoxyethylene (meth) acrylate, and polyoxyethylene (meth) acrylate. Anionic polymerizable emulsifiers such as sodium phosphate ester; and nonionic polymerizable emulsifiers such as polyoxyethylene alkyl benzene ether (meth) acrylate and polyoxyethylene alkyl ether (meth) acrylate.

As the organic solvent for the solution polymerization, methyl alcohol, ethyl alcohol, propyl alcohol,
Alcohols such as isopropyl alcohol and butyl alcohol; ethers such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; esters such as methyl acetate and ethyl acetate; and aromatic hydrocarbons such as toluene and xylene. The polymerization conditions are usually
The polymerization temperature is 50 to 150 in the presence of a radical polymerization initiator.
C., polymerization time is about 1 to 10 hours. As the radical polymerization initiator, in the case of solution polymerization, organic peroxides such as benzoyl peroxide, lauroyl peroxide, t-butyl peroxypivalate, diisopropyl peroxy percarbonate, cumene hydroperoxide, and t-butyl hydroperoxide Compounds: 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-
An oil-soluble initiator such as an azo compound such as dimethylvaleronitrile) is used. For the emulsion polymerization, a water-soluble initiator such as potassium persulfate, ammonium persulfate or hydrogen peroxide; a redox initiator obtained by combining an organic peroxide with a reducing agent such as sodium bisulfite or triethanolamine is used. You.

The resin (A) used in the present invention comprises:
The acid value before neutralization is 50 to 300, preferably 80 to 200
belongs to. If the acid value is too small, the solubility in water is poor, and the dispersion stability during the polymerization of the unsaturated monomer mixture (B) containing the diene monomer may be poor. When the acid value is too large, when a polymer obtained by emulsion polymerization of the unsaturated monomer mixture (B) is used as a base polymer of a conductive paint, the drying speed after application is reduced or the polymer is dried. The water resistance of the formed conductive layer may be reduced. Also,
The weight average molecular weight of the resin (A) before neutralization is 500 to 5
000, preferably 1,000 to 20,000. If the weight average molecular weight is too small, the monomer mixture (B)
The dispersion stability may be reduced due to the low viscosity during the polymerization. If the weight average molecular weight is too large, aggregation may occur during emulsion polymerization. Before neutralization, the resin (A) contains an ethylenically unsaturated carboxylic acid, and the type and composition of each monomer are not particularly limited as long as the acid value is within the above range. However, the amount of the hydrophobic monomer whose solubility in 100 g of water at 20 ° C. is smaller than 0.2 g is usually 50% by weight or less. When this amount is more than 50% by weight, the resin (A) becomes poor in water solubility.

To neutralize carboxyl groups, ammonia,
Organic amines or alkali metal or alkaline earth metal hydroxides are used as neutralizing agents. Examples of the organic amine include methylamine, ethylamine, isopropylamine, dimethylamine, N, N-dimethylethanolamine, diisopropylamine, trimethylamine,
Triethanolamine, sodium hydroxide, potassium hydroxide, or the like, or a mixture thereof is used. The degree of neutralization is based on the theoretical amount of polymerization of the ethylenically unsaturated carboxylic acid. When partially neutralizing, the degree of neutralization is preferably at least 70%, more preferably at least 90%. If the degree of neutralization is too low, the dispersion stability when polymerizing the unsaturated monomer mixture (B) may be low.

The resin (A) obtained by neutralization is dissolved or dispersed in water and used as a dispersion stabilizer for the polymerization of the unsaturated monomer mixture (B). When the resin (A) is obtained by solution polymerization in an organic solvent, water is added at the same time as or before or after the neutralization treatment and the organic solvent is removed by distilling off to remove the resin. It is operationally preferable to replace the medium with an aqueous dispersion.

The unsaturated monomer mixture (B) to be polymerized in the presence of the resin (A) preferably contains 3 to 90% by weight, more preferably 7 to 90% by weight of a monomer unit derived from a diene monomer. 80
% By weight, particularly preferably 20 to 40% by weight, and a monomer unit derived from an ethylenically unsaturated monomer is preferably 97 to 1%.
It contains 0% by weight, more preferably 93 to 20% by weight, particularly preferably 80 to 60% by weight. If the diene-based monomer is too small, the flexibility of the base polymer may be insufficient, and the conductive layer may be easily peeled from the substrate,
Conversely, if the amount of the diene-based monomer is too large, the base polymer becomes too soft, and the conductive material may easily fall off the conductive layer.

As the diene monomer, for example, 1,3
-Butadiene, isoprene, 2,3-dimethyl-1,3
-Butadiene, 1,3-pentadiene and the like;
3-Butadiene and / or isoprene are preferred.
The ethylenically unsaturated monomer is not particularly limited as long as it can be copolymerized with the diene monomer. For example, the ethylenically unsaturated monomers exemplified as the raw material monomer for the resin (A) can be used. In addition to carboxylic acids and their comonomers, sulfonic acid group-containing monomers such as sodium ethylene sulfonate and acrylamidomethylpropane sulfonic acid; amino group-containing monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate Is mentioned. Among them, (meth) acrylonitrile is preferable.

As a method of polymerizing the unsaturated monomer mixture (B) in the presence of the resin (A) as a dispersion stabilizer, a radical polymerization initiator is used and added in a lump in an aqueous medium. Polymerization may be performed, or a mixed emulsion of the resin (A) and the unsaturated monomer mixture (B) may be prepared in advance, and this may be continuously fed to a polymerization reactor in which water and a radical polymerization initiator are charged. The polymerization may be carried out while being added periodically. In order for the base polymer to exhibit sufficient adhesion strength, it is preferable to carry out polymerization by adding the base polymer at a time. The polymerization temperature is usually 0 to 100 ° C, preferably 30 to 80 ° C, and the polymerization time is usually 1 to 20 hours. Examples of the radical polymerization initiator include water-soluble initiators such as potassium persulfate, ammonium persulfate, and hydrogen peroxide; organic peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, benzoyl peroxide, and t-butyl peroxide. Redox initiators obtained by combining a substance with a reducing agent such as sodium bisulfite or triethanolamine.

The amount of the radical polymerization initiator used varies depending on the type of the initiator used, and an appropriate amount is used for each. Usually, the amount of the unsaturated monomer mixture (B) is 100%.
It is in the range of 0.05 part by weight or more and 5 parts by weight or less with respect to parts by weight. As long as the effects of the present invention are not substantially impaired, ordinary emulsifiers other than the resin (A), for example, sodium dodecylbenzenesulfonate, sodium lauryl sulfate,
An anionic emulsifier such as sodium dioctylsulfosuccinate and a nonionic emulsifier such as polyoxyethylene nonylphenyl ether, polyoxyethylene stearate and sorbitan laurate may be used in combination.

The base polymer preferably contains a moderate amount of gel, and the proportion of the insoluble component dissolved in tetrahydrofuran (THF) is generally 20 to 95% by weight, preferably 30 to 85% by weight. To be. If the gel content is too low or too high, the conductive material tends to fall off when used as a base polymer. The gel content is adjusted at the concentration by using a molecular weight modifier such as mercaptans, xanthogen disulfides, and halogenated hydrocarbons during the polymerization reaction. In order to prevent the gel content from increasing after the polymerization, it is preferable to add a terminator such as sodium nitrite, hydroxylamine sulfate or N, N-diethylhydroxylamine at the end of the polymerization reaction. Also, the glass transition temperature (Tg) of the base polymer
Can be measured by a differential scanning calorimeter (DSC). Preferred Tg is -60 to 50C, more preferably -50 to 30C. If the Tg is too low, the mechanical strength of the coating may decrease, and if it is too high, the flexibility of the coating may deteriorate.

The mixing ratio of the resin (A) and the monomer mixture (B) is 5 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the monomer mixture (B). Parts, more preferably 15 to 40 parts by weight. If the amount of the resin (A) is too small, the particle size of the obtained base polymer becomes large, the dispersion stability during polymerization is lowered, and even if a conductive layer is formed using the obtained base polymer, Is not sufficiently smooth. Conversely, if the amount is too large, the drying speed of the conductive paint is reduced. The preferred average particle size of the base polymer is 0.01-1 μm, more preferably 0.01 μm.
5 to 0.5 μm. If the average particle size is too small, the viscosity may be increased in the case of a water-based paint, which may make it difficult to apply. On the other hand, if the average particle size is too large, the mechanical strength of the coating film may be reduced in the case of a water-based paint.

The conductive coating composition of the present invention is obtained by mixing the above-mentioned base polymer, conductive material and water or an organic solvent. 90 to 45% by weight of the conductive material, more preferably 15 to 50% by weight of the base polymer and 85 to 50% by weight of the conductive material. In addition, the total solid content in the conductive paint is used at an appropriate concentration so as to have a viscosity suitable for a coating method. Methods for obtaining conductivity include a method based on electron conduction and a method based on ionic conduction. When the ratio of the conductive material in the coating decreases and the ratio of the base polymer increases, the method using electron conduction becomes effective. However, when the proportion of the base polymer exceeds 55% by weight of the coating, the conductivity of electrons is also deteriorated, which is not preferable. On the other hand, in order for the conductive paint of the present invention to have sufficient film strength, it is preferable that the base polymer contains 10% by weight or more. When the base polymer occupies 10% by weight or more of the coating, the conduction of ions deteriorates, but the electronic conduction, which is the purpose of the conductive coating of the present invention, is kept effective.

The conductive material to be incorporated in the conductive paint of the present invention includes carbon; metals such as gold, silver and copper; metal oxides such as tin oxide and indium oxide; and conductive organic substances such as polypyrrole and polyacetylene. Can be used. Preferably, carbon, copper, silver and the like are used.
The shape of the conductive material is not particularly limited, and a spherical or amorphous powder or a short fiber such as a chip or a whisker can be used. The conductive paint of the present invention, in addition to the conductive material, depending on the purpose, pigment, dye, filler, plasticizer, ultraviolet absorber,
A fiber reinforcement or the like can be added.

The water-based conductive paint is usually prepared by adding a conductive material to an aqueous base polymer dispersion, but in order to adjust the viscosity of the paint, a water-soluble polymer such as carboxymethylcellulose or methylcellulose is used as a thickener. It may be added. At this time, the water-soluble polymer is preferably 5 to 20 parts by weight based on 100 parts by weight of the base polymer.
0 parts by weight, more preferably 10 to 150 parts by weight. If the amount of the water-soluble polymer is too small, there is no thickening effect, and if it is too large, the conductive layer is liable to crack or chip.

In the water-based conductive paint, an acrylic resin emulsion, a vinyl acetate resin emulsion,
In addition, various additives and the like can be blended. Also,
A hydrophilic organic solvent such as alcohols, cellosolves, glycols, and glycerin may be appropriately added according to the purpose of improving drying properties and film forming properties.

In a method for preparing an organic solvent-based conductive coating, a base polymer latex obtained by emulsion polymerization is replaced with a dispersion medium and dissolved or dispersed in an organic solvent to mix a conductive material. A known method can be used for the method of replacing the dispersion medium. For example, a method of dispersing or dissolving a base polymer powder obtained by drying a latex base polymer in an organic solvent, adding an organic solvent having a boiling point higher than water to the latex base polymer, and then distilling water. There is a method of removing. Examples of the organic solvent include toluene, xylene, acetone, THF, dimethyl sulfoxide (DMSO), dimethylformamide (DM
F), N-methylpyrrolidone (NMP), butyl acetate,
Ethyl acetate and the like can be used. Preferably, it has a boiling point of 300 ° C. so as to be easily dried after being applied as a paint.
The following solvents are preferred.

The conductive laminate of the present invention has a film formed of a conductive paint and a base. The coating is obtained by applying the conductive paint of the present invention to a substrate and then removing the solvent or the dispersion medium by a method such as drying. The method of applying to the conductive paint substrate is not limited, and roll coating, doctor
Any method such as blading, brush coating, spray coating, and dipping may be adopted. After applying the conductive paint, the solvent or the dispersion medium is removed by natural drying or heat drying to form a film. The thickness of the coating is usually 0.5 to 1,000 μm, preferably 1 to 500 μm.
m, more preferably 5 to 300 μm. If the thickness of the coating is excessively thin, the change in electric resistance may be extremely large when the coating is scratched. Conversely, if the thickness of the coating is excessively large, the coating is easily broken when subjected to bending deformation. There is a risk. The material used for the substrate is not limited, and various materials can be used. For example, polymers such as polyethylene terephthalate, polypropylene, polyethylene and polyimide; copper, aluminum, iron, nickel, SU
A metal such as S is used. The shape of the substrate is not limited, and a substrate having a shape such as a film, a plate, a sphere, and a lump can be used.

The thus obtained conductive laminate of the present invention comprises an antistatic plastic film, an antistatic coating for plastic molded articles, an electromagnetic wave shield, a heating element,
It is effectively used for flexible circuit boards.

[0027]

EXAMPLES The present invention will be specifically described below with reference to Reference Examples, Examples and Comparative Examples, but the present invention is not limited thereto. Parts and% in the following description are based on weight unless otherwise specified. Reference Example 1 100 parts of isopropyl alcohol was charged into a reactor, and 8
Keeping at 0 ° C., 10 parts of styrene, 70 parts of methyl methacrylate, 20 parts of methacrylic acid, 2,2′-azobis-
2.5 parts of (2,4-dimethylvaleronitrile) and 12.5 parts of toluene were added dropwise at a constant rate over 4 hours, and the reaction was further performed at 80 ° C. for 2 hours. The reactor was cooled to 25 ° C, a small amount of a sample for measuring the acid value was sampled, neutralized by dropwise addition of aqueous ammonia (28% ammonia concentration), and 400 parts of ion-exchanged water were added. Then, isopropyl alcohol and excess water were distilled off to obtain a 25% aqueous solution of the resin (A1). The acid value of the resin (A1) before neutralization was 130, and the weight average molecular weight was 13,000.

Reference Example 2 300 parts of ion-exchanged water were charged into a reactor, and 28.5 parts of ethyl acrylate, 44 parts of methyl methacrylate, 27.5 parts of methacrylic acid, and polyoxyethylene nonylpropenyl phenyl ether sulfate ammonium salt 1 And 8 parts of octyl thioglycolate were added, and the temperature was raised to 70 ° C. while stirring. Subsequently, an aqueous solution of an initiator in which 0.5 part of potassium persulfate was dissolved in 10 parts of ion-exchanged water was added, a polymerization reaction was carried out for 1 hour, and the mixture was cooled to room temperature. Next, the reaction mixture was neutralized by dropwise addition of aqueous ammonia, and ion-exchanged water was further added to obtain a 25% aqueous solution of resin (A2). The acid value of the resin (A2) before neutralization is 179, and the weight average molecular weight is 1
It was 0000.

Test Evaluation Method (1) Measurement of Adhesive Strength The adhesive strength of the conductive layer was measured by a grid tape method described in JIS K5400. Using a cutter guide with a gap of 1 mm, make a cut in a grid pattern, attach a cellophane tape, hold one end of the tape in one minute after 1 minute, peel off the tape perpendicular to the application surface and evaluate the state of the grid pattern did. Numerical values are evaluation values according to the rules of the test method, and 10 indicates that no peeling was observed on the grid, and hereinafter, the smaller the value, the greater the peeling. (2) Measurement of the resistance value of the conductive layer On the conductive layer, a thickness of 2 mm, a width of 10 mm, and a length of 50 mm
Were placed in parallel at an interval of 10 mm, and a 100 g weight was placed on each of them to measure the resistance value between the copper plates brought into contact with the conductive layer. (3) Measurement of change in appearance and resistance value of the conductive film after expansion and contraction The conductive film was cut into a rectangle having a length of 30 cm and a width of 10 cm, and the short end was fixed with a jig, and the jig interval was changed from 25 cm to 20 cm. The conductive film was stretched and deformed by setting it again to 25 cm. After the expansion and contraction was performed 10, 50, and 100 times, the appearance of the conductive layer was observed, and the presence or absence of cracks, chips, and cracks was visually examined. When no crack, chipping or crack was observed, it was evaluated as ○, when cracked, Δ, and when cracked or broken, ×. Furthermore, the resistance value was measured, and the relative value to the value 100 before expansion and contraction was shown.

Example 1 120 parts of water, 80 parts of the aqueous solution of the resin (A1) obtained in Reference Example 1 (containing 20 parts of an aqueous neutralized resin), 0.05 parts of tetrasodium ethylenediaminetetraacetate, 0.1 part of potassium persulfate.
02 parts, butadiene 55 parts, acrylonitrile 35 parts,
10 parts of methyl methacrylate and 0.7 part of tertiary dodecyl mercaptan were charged, and emulsion polymerization was carried out while stirring at a temperature of 60 ° C. until the polymerization conversion reached 98%. Evaporate under reduced pressure for 30 minutes, add water to adjust the solid concentration, and solid concentration 40%
(A1) was obtained. A part of the polymer was coagulated with methanol and vacuum-dried at a temperature of 60 ° C. for 24 hours. The obtained polymer had a Tg of −22 ° C. and a gel content of 82%. Base polymer aqueous dispersion (a1) 5
0 parts (solid content: 20 parts), 5 parts of carboxymethyl cellulose were added, and conductive carbon (Ketjen Black E) was added.
C, made by Ketjen Black International) 45
Parts, water is further added and mixed to give a total solid content of 50 parts.
% Slurry was obtained to obtain a conductive paint (a2).
The conductive paint (a2) was applied on a commercially available polyethylene terephthalate (PET) film having a thickness of 0.1 mm using a doctor blade having a gap of 300 μm, and dried at a temperature of 80 ° C. for 3 hours. The thickness of the obtained conductive film (a3) was 80 μm. The result of the measurement of the adhesive strength and the stretching test of the conductive layer is shown in FIG.

Example 2 The same procedure as in Example 1 was carried out except that the amount of acrylonitrile was changed from 35 parts to 40 parts and glycidyl methacrylate was replaced by 5 parts instead of 10 parts of methyl methacrylate. A dispersion (b1) was prepared, and a conductive paint (b2) and a conductive film (b3) were similarly produced. The Tg of the base polymer is −23 ° C., and the gel content is 78.
%, And the film thickness was 75 μm. Table 1 shows the results of the measurement of the adhesive strength and the stretching test.

Example 3 In Example 1, the amount of butadiene was changed from 55 parts to 25 parts, and instead of 10 parts of methyl methacrylate, 20 parts of methyl methacrylate and 20 parts of 2-ethylhexyl acrylate were used.
A base polymer aqueous dispersion (c1), a conductive paint (c2), and a conductive film (c3) were produced in the same manner as in Example 1 except that the components were changed to parts. The Tg of the base polymer is -7C,
The gel content was 76% and the film thickness was 76 μm.
Table 1 shows the results of the measurement of the adhesive strength and the stretching test.

Example 4 To 100 parts of the aqueous base polymer dispersion (a1) of Example 1, 400 parts of N-methylpyrrolidone was added and mixed.
Water was removed by heating and reducing the pressure to 80 ° C. using a rotary evaporator. When the residual water content became 2000 ppm, the treatment was terminated, and an organic solvent-based base polymer composition (d1) having a solid content of 10.5% was obtained. To 100 parts of the composition (d1), 30 parts of conductive carbon and 2 parts of methylcellulose were added and uniformly mixed to prepare an organic solvent-based conductive paint (d2). The paint (d2) was added to gap 3
Using a doctor blade of 00 μm, thickness 0.1 mm
And then kept at 80 ° C. for 3 hours, dried at 5 mmHg at 80 ° C. for 2 hours with a vacuum drier to prepare a conductive film (d3), and measured for an adhesion test and a stretch test. The results obtained are shown in Table 1.

Comparative Example 1 100 parts of water, 1.0 part of sodium dodecylbenzenesulfonate emulsifier, 0.5 part of sodium bicarbonate, 0.05 part of tetrasodium ethylenediaminetetraacetate as a chelating agent were placed in a pressure vessel.
Parts, potassium persulfate 1.0 part, 1.3-butadiene 55
Part, acrylonitrile 40 parts, methyl methacrylate 5
Parts, and 0.7 part of a molecular weight modifier tertiary dodecyl mercaptan, and after a polymerization reaction at 60 ° C., unreacted monomers were distilled off under reduced pressure.
The latex composition (e1) was obtained. After this,
Conductive film (e3) in the same manner as in Example 1 except that latex composition (e1) was used as the latex composition.
Was prepared. The Tg of the base polymer was −21 ° C., the gel content was 83%, and the film thickness was 82 μm. Table 1 shows the results of the measurement of the adhesive strength and the stretching test.

COMPARATIVE EXAMPLE 2 Using the aqueous base polymer dispersion (e1) of Comparative Example 1, an organic solvent-based conductive paint (f2) was prepared in the same manner as in Example 4, and a conductive film (f3) was similarly prepared. Produced. The film thickness was 84 μm. Table 1 shows the measurement results of the adhesion test and the stretching test.

EXAMPLE 5 The aqueous base polymer dispersion (a1) of Example 1 and the aqueous base polymer dispersion (e1) of Comparative Example 1 were mixed at a solid content ratio of 98/2, respectively. In the same manner as in the above, a conductive film (g3) was produced. The film thickness was 76 μm. Table 1 shows the measurement results of the adhesion test and the stretching test.

Example 6 In Example 1, an aqueous solution of the resin (A2) was used in place of the aqueous solution of the resin (A1).
In the same manner as in Example 1, except that 10 parts of methyl methacrylate was changed to 20 parts. T of the obtained base polymer
g was -5 ° C and the gel content was 80%. The film thickness was 77 μm. Table 1 shows the measurement results of the adhesion test and the stretching test.

[0038]

[Table 1]

As can be seen from Comparative Example 1, a conductive paint obtained by adding a conductive material to a polymer latex obtained by a usual emulsion polymerization using an emulsifier (sodium dodecylbenzenesulfonate) as a base polymer has the following properties. In the conductive film, the adhesive strength of the conductive layer was low, cracks were generated by bending, and the resistance value was significantly increased. Further, as shown in Comparative Example 2, even when the polymer latex was replaced with an organic solvent as a dispersion medium to prepare an organic conductive paint, the adhesive strength of the conductive film was not improved, and cracking due to bending occurred. And an increase in the resistance value was considerably large. On the other hand, having a monomer unit derived from an ethylenically unsaturated carboxylic acid,
When using the conductive paint of the present invention using a base polymer obtained by polymerizing the resin (A1) obtained by neutralizing a polymer obtained by solution polymerization having an acid value of 50 to 300 as a dispersion stabilizer, Regardless of whether the medium was an aqueous medium (Examples 1 to 3) or an organic medium (Example 4), the obtained conductive film had high adhesive strength, and no change was observed in appearance and resistance value even in a bending test. In addition, as long as the base polymer according to the present invention is mainly used, latex by ordinary emulsion polymerization is several%.
Even when mixed, the obtained conductive film gave good results in the adhesive strength and bending test (Example 5). Further, having a monomer unit derived from ethylenically unsaturated carboxylic acid,
A conductive paint using a base polymer obtained by polymerizing a resin (A2) obtained by neutralizing a polymer obtained by emulsion polymerization having an acid value of 50 to 300 as a dispersion stabilizer, as in Example 1, A conductive film having high adhesive strength and having no change in appearance and resistance even in a bending test was provided (Example 6).

[0040]

Industrial Applicability According to the present invention, a conductive layer is formed which has good conductivity, does not easily fall off the conductive material even if the substrate is deformed due to bending or the like, and has a large adhesiveness to the substrate. And a laminate using the same.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 5/24 C09D 5/24 5G307 109/02 109/02 133/00 133/00 157/00 157/00 H01B 1/20 H01B 1/20 A 1/22 1/22 A 1/24 1/24 A 5/14 5/14 Z F term (reference) 4F100 AA37H AK11A AK21 AK24A AK25 AK28A AK42 AL05A AT00B BA02 CA21 CC00 GB41 JA20A JG01 JL11 4J011 PA69 PB14 PB15 PC02 PC08 4J026 AA43 AC36 BA31 BA46 BA47 BB01 BB03 CA01 CA04 DA02 DA04 DA07 DA08 DA15 DB04 DB08 DB15 DB19 DB24 DB34 FA04 GA08 GA09 4J038 CA021 CA022 CC021 CG1 CG01 CG031 CG031 CG031 CG031 CG031 CG172 CJ131 CJ132 CN002 CP001 CP061 CP071 CR071 CR072 DC002 GA06 HA026 HA066 HA156 HA216 KA06 KA09 KA12 MA08 MA10 NA12 NA20 5G301 DA03 DA06 DA18 DA42 DD02 5G307 GA02 GC02

Claims (5)

[Claims] 1. A conductive paint comprising a base polymer, a conductive material, and water or an organic solvent, wherein the base polymer has a monomer unit derived from an ethylenically unsaturated carboxylic acid, and has an acid value. Resin (A) 5 obtained by at least partially neutralizing a polymer of 50 to 300
To 100 parts by weight of a monomer mixture (B) containing a diene monomer and an ethylenically unsaturated monomer in an aqueous medium in the presence of 100 parts by weight. Characteristic conductive paint. 2. The conductive paint according to claim 1, wherein the diene monomer is 1,3-butadiene and / or isoprene, and the ethylenically unsaturated monomer is (meth) acrylonitrile. 3. The conductive paint according to claim 1, comprising 5 to 55% by weight of the base polymer and 95 to 45% by weight of the conductive material as a coating component. 4. A conductive laminate having a coating containing a base polymer and a conductive material, and a substrate, wherein the base polymer has a monomer unit derived from an ethylenically unsaturated carboxylic acid, Resin (A) 5 obtained by at least partially neutralizing a polymer having an acid value of 50 to 300
To 100 parts by weight of a monomer mixture (B) containing a diene monomer and an ethylenically unsaturated monomer in an aqueous medium in the presence of 100 parts by weight. Characteristic conductive laminate. 5. A resin (A) 5 to 100 obtained by at least partially neutralizing a polymer having a monomer unit derived from an ethylenically unsaturated carboxylic acid and having an acid value of 50 to 300.
A monomer mixture (B) 1 containing a diene monomer and an ethylenically unsaturated monomer in an aqueous medium in the presence of parts by weight;
Base polymer for conductive paint obtained by polymerizing 00 parts by weight.