JPH05320542A - Electrically conductive coating film - Google Patents

Abstract

PURPOSE:To obtain an electrically conductive coating film useful for microfilms, etc., having excellent surface intrinsic resistance, environmental stability, solvent resistance and mechanical strength by curing a composition comprising a film- forming ionic electrically conductive polymer and an ethylenically unsaturated bond-containing compound. CONSTITUTION:A composition comprising a film-forming ionic electrically conductive polymer such as a polyamide resin and an ethylenically unsaturated bond-containing compound such as acrylic acid is cured to give the objective electrically conductive coating film. The coating films preferably contains electrically conductive powder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive coating, and more particularly to a conductive coating excellent in environmental stability of electric resistance.

[0002]

2. Description of the Related Art To obtain a conventional conductive film, the following 3
Many types of materials are used. That is, (1) a metal powder of zinc, silver, copper, gold or the like or a conductive powder such as carbon black dispersed in a non-conductive resin to form a film, (2) polyvinylbenzyl quaternary ammonium salt Forming a film with a resin material containing a low molecular weight polyelectrolyte as a main component, such as polystyrene sulfonic acid or a metal salt of polyvinyl pyridine, and (3)
Some photopolymerizable materials contain a polymerizable ethylenically unsaturated compound having an ionic free radical to form a film. However, since the first method uses a large amount of the filler, it has a drawback that a film having high strength and good optical and solvent resistance cannot be obtained. In order to improve solvent resistance, it has been reported that conductive powder is added to thermosetting resins such as epoxy resin, phenol resin, melamine resin, and melamine-guanamine resin. Is not satisfied. In the second method using a polymer electrolyte such as polystyrene, sulfonic acid, polyvinylbenzyl quaternary ammonium salt, or polyvinylpyridine, the optical properties of the film are satisfied, but the above polymer compound is stabilized. It is difficult to obtain, and the film forming properties, mechanical properties and solvent resistance of the film are poor, and furthermore, these resins have the drawbacks of being extremely expensive.

In addition, conductive coatings such as polyethers and polyurethanes can be obtained by thermal crosslinking of polymer electrolytes, but these are not always satisfactory in terms of mechanical properties and solvent resistance. .. Further, in the third method of forming a film from a photopolymerizable material containing a polymerizable ethylenically unsaturated compound having an ionic free radical, the solvent resistance, mechanical properties and optical properties as described above are used. A conductive coating with almost satisfactory performance in terms of physical properties can be obtained, but when the coating has sufficient hardness and is cured enough to give good solvent resistance, a coating is obtained. In particular, the conductivity of the cured film is lowered, and satisfactory conductivity cannot be obtained.

[0004]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide excellent mechanical strength, good stability of conductivity with respect to temperature and humidity, and excellent conductivity with excellent optical characteristics and solvent resistance. To provide a film.

[0005]

The above-mentioned problems are caused by curing the conductive film of the present invention, that is, a composition containing a film-forming ion conductive polymer and a compound having at least an ethylenically unsaturated bond. This can be solved by a conductive film formed by.

This conductive film is used as a microfilm, a magnetic tape, a conductive tape for a thermal transfer ribbon, a printed wiring board, a conductive resist, a magnetic shield and a magnetic shield coating, an antistatic coating, electrochromism, an electrode for electroluminescence. Also, it can be used over a wide range of electrode materials such as CRT electrodes.

Examples of the film-forming ion-conductive polymer used in the present invention include polyamide resin, polyether derivative, polyester derivative, polysulfide derivative, polyethyleneimine, acrylamide derivative and cellulose derivative. Among these, polyamide resins are particularly preferable from the viewpoint of solvent resistance and mechanical properties, and specifically, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 61.
2, and then an aromatic nylon of the general formula,

[0008]

[Outer 1] (Wherein R ₁ and R ₂ represent an alkyl group) and N-alkoxymethylated nylon, and a copolymerized nylon having each composition, specifically, a copolymer of nylons 66 and 6, nylon 6 and nylon 12 Examples include copolymers,
In particular, it does not have to be a copolymer of two types of nylon, and more nylon components may be copolymerized.

According to the present invention, by directly radically polymerizing and / or cross-linking an ion conductive polymer, it has a good film-forming property which has not been obtained in the past, and is excellent in optical properties, solvent resistance and electrical properties. Another object of the present invention is to provide a conductive film, which has a structure in which ion conductive polymers are cross-linked with each other.

In the composition of the present invention, a compound having an ethylenically unsaturated bond is added to the ion conductive polymer. Basically, in the case of a polyamide resin as an ion-conductive polymer, when a compound that generates a radical by heat or active actinic radiation described below is added alone without adding a compound having an ethylenically unsaturated bond The generated radicals also cause crosslinking in principle, but the degree of crosslinking is low and not efficient.

As the above-mentioned compound having an ethylenically unsaturated bond, a known acryl or methacryl monomer used for thermal or photopolymerization can be used. Specific examples of such acrylic monomers and methacrylic monomers include acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, Benzyl methacrylate, carbitol methacrylate, 2
-Ethylhexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, 2
-Hydroxypropyl methacrylate, glycidyl methacrylate, acrylamide, methacrylamide, N-methylol methacrylamide, N-diacetone methacrylamide, N, N'-methylenebismethacrylamide, styrene, acrylonitrile, vinyl acetate, N-vinylpyrrolidone, Ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,4-butanediol diacrylate,
1,6-hexanediol dimethacrylate, pentaerythritol acrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, general formula (I
I) a phenol-modified acrylate,

[0012]

[Outside 2] (R ₃ is an alkyl group having 2 to 6 carbon atoms, R ₄ is an alkyl group having 1 to 10 carbon atoms) and ε-caprolactone modified hydroxyethyl methacrylate, a glycidyl methacrylate derivative of bisphenol A, isocyanuric acid monoacrylate. , Isocyanuric acid diacrylate, isocyanuric acid triacrylate, and derivatives thereof, methacrylate of aromatic carboxylic acid such as monohydroxyethyl methacrylate phthalate, methacrylate of aliphatic carboxylic acid such as monohydroxyethyl methacrylate succinate, Further, there may be mentioned methacrylates of aromatic and aliphatic sulfonic acids and phosphoric acid methacrylates.

These compounds having an ethylenic double bond are not only used as a cross-linking agent for assisting the cross-linking, but especially by having a group having a releasable hydrogen atom at the same time as the ethylenic double bond. It is preferable for conductivity because hydrogen ions can be replenished between the formed polymer chains. Such an aryl monomer or a methacrylic monomer can be added to the composition of the present invention in any proportion.

The composition of the present invention contains, in addition to the above-mentioned compounds,
An initiator capable of generating active radicals by heat or active actinic radiation is added. Specific examples of the thermal radical initiator include cumene hydroperoxide and t
Other organic peroxides such as butyl hydroperoxide, di-tert-butyl peroxide, benzoyl peroxide, azobisisobutyronitrile and acetyl peroxide,
Inorganic peroxides such as hydrogen peroxide-Fe ²⁺ salts, persulfates-NaHSO ₃ and mixtures such as benzoyl peroxide-dimethylaniline can also be used, among which
The initiators of hydrogen peroxide-Fe ²⁺ salt, persulfate-NaHSO ₃ and benzoyl peroxide-dimethylaniline have a very short pot life of the composition. Specific examples of the above-mentioned photoradical initiator include benzoin ethers, benzophenones, xanthones, and various derivatives other than acetophenone derivatives. Typical photoinitiators include benzoin ether and benzophenone. ,
Michler's ketone, 0-benzoylmethyl, xanthone, thioxanthone, 2-chlorothioxanthone, 2-
Alkylated thioxanthone, 2,4-dialkylated thioxanthone, acetophenone, trichloroacetophenone, 2,2-diethoxyacetophenone, benzyldimethylketal, benzyl, 2-ethylanthraquinone,
Methyl benzoyl formate, 2-hydroxy-2-methyl propiophenone, 2-hydroxy-4-isopropyl-2-methyl propiophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4-
(Methylthio) phenyl] 2-morpholine-1-propanone, 2,4,6-trimethylbenzoylphosphine oxide, alpha hydroxyisobutyrophenone polymer, and S-triazine derivative.

The composition of the present invention may further contain a long wavelength sensitizer. Such an initiator is preferably added to the composition in a range of 0.1% by weight to 10% by weight. Considering the curing rate and efficiency, the physical properties of the coating, etc. It is more preferable to add within the range.

Heat and / or actinic radiation can be used to cure the compositions of the present invention. In heat curing, a known heat source, as well as a heat source such as an infrared lamp or a tungsten lamp can be used. Examples of the actinic rays include X-rays, ultraviolet rays and visible rays, and electron beam lasers and the like may be used.

The composition of the present invention further comprises a heat- and photo-curable polymerizable methacrylate polymer having an ethylenically unsaturated bond, unsaturated polyester, melamine resin, guanamine resin, epoxy resin, melamine. -A prepolymer such as a guanamine resin or a urea resin may be added. By adding such a prepolymer, desired properties such as coating property and adhesion to a substrate can be controlled without deteriorating desired properties such as hardness and solvent resistance, and optical properties. Inventive compositions can be provided. When the composition of the present invention contains a polymerizable prepolymer having an ethylenically unsaturated bond at the same time as the polyamide resin, the composition can be simultaneously cured by photocuring after the film is formed. Further, when the composition of the present invention is used in a mixture with thermosetting resins, both heating and light irradiation are applied, and in this case, any curing step may be applied first.

The composition of the present invention can be basically used by mixing the above-mentioned compositions and using it as a compound, or by adding a solvent to form a solution and then applying it, followed by curing to form a conductive film. Can be Specific examples of such a solvent include aliphatic carboxylic acids such as formic acid, acetic acid and propionic acid, phenols and phenols such as cresol, N, N-dimethylformamide, dimethyl sulfoxide, methyl alcohol, ethyl alcohol and n-propyl alcohol. , I-propyl alcohol, n-butyl alcohol, i-butyl alcohol, n-amyl alcohol, i-amyl alcohol, cyclohexanol and other aliphatic alcohols, benzyl alcohol, p-phenethyl alcohol and other aromatic alcohols, tetrahydrofuran, full Examples include chlorine compounds such as fleele alcohol, chloroform and methylene chloride, and fluorine-containing compounds such as freon and hexafluoroisopropanol, but are not limited to these and polyamide resins can be dissolved. May be any solvent if Re.

When the conductive coating film of the present invention is used as a molding compound, it is used in the form of a coating film by a known molding method such as extrusion molding, molding or injection molding. Further, a film may be formed by coating using a solvent, and after dissolving the composition of the present invention in a suitable solvent, bar coating, spin coating, dip coating, roll coating, applicator coating, soverse roll coating Method, gravure roll coating method,
The film may be formed by a known coating method such as a spray coating method, an electrostatic coating method, or a curtain coating method.

The thickness of the conductive film may be basically any thickness as long as it covers the substrate, but the resistance of the film itself increases. To increase. The film thickness of such a conductive film gives good conductivity in the range of 0.05 μm to 100 μm, but the film thickness can be further increased by using various conductive additives. Such conductive additives include sulfuric acid, hydrochloric acid, perchloric acid, nitric acid, salts of inorganic acids such as phosphoric acid such as lithium, sodium and potassium, organic acids such as acetic acid, propionic acid, maleic acid, phthalic acid and the like. Compounds having alcoholic hydroxyl groups such as salts, alcohols and thioalcohols, halogen compounds, metal complexes,
Pyrylium and thiopyrylium dyes, phthalocyanine and azo pigments, electron transfer pigments, squarylium dyes and pigments, crown ethers, etc., and metal powders such as titanium oxide, alumina, aluminum, copper, nickel and silver, scale-like metal powders and Short metal fibers, antimony oxide,
Conductive oxides such as indium oxide and tin oxide, carbon fiber, carbon black, graphite and the like may be added.

The composition of the present invention may optionally contain a surfactant, a silicone leveling agent, a silane coupling agent,
A titanium coupling agent or the like can be added. As described above, the conductive film of the present invention provides a film which can be formed on the surface of any support, has good solvent resistance, is optically excellent, and has good conductivity and environmental stability. However, the present invention will be described in more detail with reference to specific examples below.

[0022]

Examples (Example 1) N-methoxymethylated polyamide resin resin resin EF-3
0T (Teikoku Chemical Co., Ltd.) 10 parts Benzophenone-based radical generator (trade name: Irgacure-500, manufactured by Ciba Geigy) 0.1 part Pentaerythritol triacrylate (trade name: Biscoat # 300, Osaka Organic Chemical Co., Ltd.) 0 0.5 part was dissolved in 90 parts of methanol to obtain a paint. This is # 5
It was applied onto an aluminum sheet with a wire bar of No. 5 and dried at 80 ° C. for 5 minutes to obtain a transparent film having a film thickness of 10 μm. This coating was irradiated with a high pressure mercury lamp of 80 w / cm from a distance of about 15 cm for 5 minutes to cure the above coating to obtain a cured coating. The obtained film was conditioned at 23 ° C. and 50% RH for 24 hours, and then the resistance of the film was measured from a low temperature and low humidity to a high temperature and high humidity by a Picoammeter manufactured by Hewlett Packard. The obtained surface resistivity was 3 × 10 ¹¹ Ω / cm ² at room temperature and normal humidity, and did not substantially change under high temperature and high humidity or low temperature and low humidity. Further, when the solvent resistance of the obtained cured film was measured after the same conditioning, it was observed that the solubility in methanol was clearly decreased. Further, the surface tackiness of the obtained cured coating was observed by performing similar conditioning, superposing the coatings, applying a load of 10 g / cm ² and leaving under the same conditions, and then peeling the mutual adhesion of the coatings. However, the film was not adhered at all, and good surface hardness was obtained.

(Comparative Example 1) 10 parts of N-methoxymethylated polyamide resin (trade name: Toresin EF-30T) was dissolved in 85 parts of methanol to obtain a coating, which was formed into a film in the same manner as in Example 1 The surface resistivity, the dissolution rate in methanol, and the surface tackiness in the environment were observed, and the surface resistivity was 8 × 10 ¹⁰ Ω / cm ² at room temperature and normal humidity.
The surface resistivity showed a change of 10 ⁴ Ω / cm ² from high temperature and high humidity to low temperature and low humidity. As for the solubility in methanol, it swelled immediately after immersion in methanol and no solvent resistance to methanol was observed. Further, the surface tackiness was observed. As a result, under the same conditions as in Example 1, the films adhered to each other even after being left for about 10 seconds, and the films were broken upon peeling.

(Examples 2 to 4) In the same manner as in Example 1,
Alcohol-soluble polyamide resin Product name: CM-800 (manufactured by Toray Industries, Inc.) Product name: Elvamide 8061 (manufactured by DuPont) Product name: Ultramid 1C (manufactured by BASF Co., Ltd.) Then, a conductive film was obtained. These conductive films show substantially no change in surface resistivity with respect to each environment, have good solvent resistance to organic solvents such as methanol, ethanol, cyclohexanone, and THF, and have surface tackiness. There was no.

(Example 5) Aromatic polyamide resin (trade name: MXD6, manufactured by Mitsubishi Gas Chemical Co., Ltd.) 10 parts Benzophenone radical generator (trade name: Irgacure 500) 0.1 part Trade name: Biscoat # 2100 (Osaka Organic Chemistry Co., Ltd.
Made)

[0026]

[Outside 3] Was dissolved in 90 parts of formic acid, dried at 120 ° C. for 10 minutes, and coated and irradiated with light in the same manner as in Example 1 to obtain a cured film. The environmental dependence of the surface resistivity, solvent resistance to formic acid, and surface tack of each of the cured films were measured.
The surface resistivity did not depend on the environment at all, the solvent resistance to formic acid was good, and the surface tackiness was not found at all.

Example 6 N-methoxymethylated polyamide resin Toresin EF-3
0T (manufactured by Teikoku Kagaku Co., Ltd.) 10 parts Epoxy acrylate (Osaka Organic Chemical Co., Ltd. viscoat # 810) 5 parts Irgacure 500 0.1 part biscoat # 2100 0.5 part 60 parts methanol, 30 parts ethyl acetate Dissolve in, and apply it on an aluminum sheet with a # 55 wire bar.
After drying for a minute, a transparent film having a film thickness of 10 μm was obtained. This was photocured in the same manner as in Example 1 to obtain a cured film. The surface resistivity of the obtained cured film was measured in the same manner as in Example 1 even though the film hardness was significantly increased.
It was × 10 ¹¹ Ω / cm ² (normal temperature and normal humidity), and the resistance value did not substantially change in each environment. In addition, good solvent resistance was obtained against solvents such as methanol and ethanol, and there was no surface tackiness at all.

(Examples 7 to 9) The epoxy acrylates described in Example 6 were respectively converted into polyester acrylates (trade name: Aronix M-
8030; manufactured by Toagosei Co., Ltd.) Polyurethane acrylate (trade name: Aronix M-
1200; manufactured by Toagosei Co., Ltd. Polyether acrylate (trade name: Aronix M-
245; manufactured by Toagosei Co., Ltd.), a cured film was obtained in the same manner as in Example 6, and the environmental dependence of the surface resistivity of each film did not substantially change, and solvent resistance was obtained. A transparent film having a good surface property and improved surface tackiness was obtained.

(Comparative Examples 2 to 10) Coating compositions having the compositions described in Examples 1 to 9 were formed in the same manner as in Example 1, and surface specific resistance, solvent resistance and surface tackiness were respectively obtained without photocuring. The surface resistivity fluctuates in a unit of about 10 ⁵ to 10 ⁶ Ω / cm ² in each environment, has no solvent resistance to each solvent, and has a surface tackiness. Only a film having poor mechanical strength was obtained.

COMPARATIVE EXAMPLE 11 Epoxy acrylate (Biscoat # 810) 10 parts Irgacure 500 0.1 parts Pentaerythritol triacrylate (Biscoat # 810)
300? (Manufactured by Osaka Organic Chemical Co., Ltd.) 0.5 part was dissolved in 60 parts of methanol and 30 parts of ethyl acetate, and film formation and photocuring were carried out in the same manner as in Example 1. The surface resistivity of this film was measured and found to be 8 × 10 ¹⁶ Ω / cm ² at room temperature and normal humidity.
No surface conductivity was obtained at all.

[0031]

INDUSTRIAL APPLICABILITY The present invention is to obtain a conductive film by curing a composition containing a film-forming ion conductive polymer and a compound having an ethylenically unsaturated bond. Thus, a conductive coating having good surface resistivity, environmental stability, excellent solvent resistance, and good surface mechanical strength can be obtained.

Claims (5)

[Claims] 1. A conductive coating film obtained by curing a composition containing a film-forming ion conductive polymer and a compound having an ethylenically unsaturated bond. 2. The conductive film according to claim 1, wherein the ion conductive polymer is a polyamide resin. 3. The conductive coating film according to claim 1, wherein the composition according to claim 1 or 2 contains a compound capable of generating an active radical by heat or active actinic radiation. 4. The conductive coating according to claim 1, wherein the conductive coating contains a conductive powder. 5. The conductive coating according to claim 3, wherein the conductive coating contains a conductive powder.