JPH0665529A - Conductive coating composition - Google Patents

Abstract

PURPOSE:To provide a coating composition which cures readily upon irradiation with ultraviolet, visible, or other light to give a conductive coating film excellent in marring resistance, transparency, and hardness. CONSTITUTION:This conductive coating composition comprises 100 pts.wt. (meth) acrylate compound having at least 2 (meth)acryloyl groups per molecule, 10-100 pts.wt. epoxy resin having at least 2 epoxy groups per molecule, 200-700 pts.wt. tin oxide containing antimony oxide and having particle diameters of 0.01-0.4mum, 1-40 pts.wt. photopolymerization initiator, and 10-200 pts.wt. copolymer of methyl methacrylate and a monomer represented by the formula (wherein R<1> and R<2> each is H or methyl and (n) is an integer of 1-10).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive coating composition which can be easily cured by ultraviolet rays or actinic rays to form a coating film having excellent scratch resistance, hardness and transparency.

[0002]

2. Description of the Related Art Semiconductor wafer storage containers, electronic and electrical components, floor materials and wall materials for semiconductor manufacturing factories are required to have antistatic properties depending on their applications. Therefore, conventionally, a method of coating these containers and members with a coating material containing carbon powder or metal powder, or kneading carbon powder, carbon fibers, metal fibers, or the like into a resin and molding the resin have been performed. . However, these methods have a problem in that the coating film and the molded product themselves are colored and thus become opaque, so that they cannot be used in the window portion where the contents need to be seen through.

Further, for example, Japanese Patent Application Laid-Open No. 57-85866 discloses a paint containing a conductive fine powder containing tin oxide as a main component in a paint binder. However, this coating material is transparent and can form a coating film having an antistatic function, but since the coating binder is a thermoplastic resin, generally only a coating film having insufficient scratch resistance and solvent resistance can be obtained. There is a problem that it does not exist.

Further, Japanese Patent Application Laid-Open No. 60-60166 proposes a coating material which is cured with ultraviolet rays or visible rays in order to improve scratch resistance and solvent resistance.
However, although this paint has excellent conductivity and transparency, there is a problem in that a coating film having sufficient hardness and scratch resistance cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its purpose is to easily cure by ultraviolet rays or visible light, and the formed coating film has abrasion resistance. It is intended to provide a coating composition having excellent properties, transparency and hardness.

[0005]

The conductive coating composition of the present invention has (a) at least two acryloyl groups or (meth) acryloyl groups in the molecule (meth).
With respect to 100 parts by weight of the acrylate compound, (b) 10 to 100 parts by weight of an epoxy resin having at least two epoxy groups in the molecule, (c) a particle size of 0.01 to 0.4.
50 to 500 parts by weight of tin oxide containing antimony oxide of μm,
(D) 1 to 20 parts by weight of a photopolymerization initiator and (e) 10 to 200 parts by weight of a copolymer of methyl methacrylate and a monomer represented by the general formula (I).
Thereby, the above object is achieved.

The present invention will be described in detail below. The (meth) acrylate compound (a) used in the present invention has at least two or more acryloyl groups or methacryloyl groups in the molecule, and examples thereof include ethylene glycol di (meth) acrylate and diethylene glycol di ( (Meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, nonaethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene Glycol di (meth) acrylate, nonapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate , Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerol tri (meth) acrylate, tris- (2-hydroxylethyl) -isocyanuric acid ester ( (Meth) acrylate, 2,2-bis [4
-(Acryloxydiethoxy) phenyl] propane,
2,2-bis [4- (methacryloxydiethoxy) phenyl] propane, 3-phenoxy-2-propanoyl acrylate, 1,6-bis (3-acryloxy-2-
Hydroxypropyl) -hexyl ether and the like can be mentioned.

Examples of the (meth) acrylate compound (a) other than the above include acrylic urethane oligomers having a urethane bond in the molecule of an acrylic monomer, and when the oligomer is used, the scratch resistance of the coating film is further improved. .

The urethane oligomer is prepared by polymerizing a polyol and a compound having two or more isocyanate groups in one molecule, and reacting an acrylate or methacrylate having active hydrogen with the isocyanate group at the terminal of the molecule. .

Examples of the above-mentioned polyol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol and 1,4-butane. Examples thereof include diol, 2,3-butanediol, 1,5-heptanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol and polyethylene glycol.

Examples of polyols other than those mentioned above include polyester glycols and ε-caprolactone ring-opening polymers which are condensation products of adipic acid and propanediol, adipic acid and neopentyl glycol, adipic acid and butanediol and the like.

Examples of the compound having two or more isocyanates in one molecule include m-phenylene diisocyanate, p-phenylene diisocyanate, toluene-2,4-diisocyanate and toluene-2,6-.
Diisocyanate, toluene-2,5-diisocyanate, toluene-3,5-diisocyanate, m-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4, 4'-diphenylmethane diisocyanate, 4,4'-diisocyanate-3,3'-dimethylbiphenyl, 4,4'-
Diisocyanate-3,3′-dimethylbiphenylmethane and the like can be mentioned.

Examples of the acrylate or methacrylate having active hydrogen include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, acrylic acid and the like.

The (meth) acrylate compound (a) used in the present invention may be used alone or in combination.

The conductive coating composition of the present invention contains at least 2 in its molecule in order to improve the hardness of the obtained coating film.
An epoxy resin (b) having one or more epoxy groups is contained. By polymerizing the epoxy resin (b) in the composition, the obtained coating film has sufficient hardness.

Examples of the epoxy resin (b) include bisphenol A type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin, brominated bisphenol A type epoxy resin, polyphenol type epoxy resin, polyglycidyl amine type epoxy resin. Examples thereof include resins and polyfunctional epoxy resins.

In the conductive coating composition of the present invention, if the content of the epoxy resin (b) is small, there is no effect of improving the hardness of the coating film, and if it is large, the resulting coating film becomes brittle. ) It is limited to 10 to 100 parts by weight with respect to 100 parts by weight of the acrylate compound (a).

In the conductive coating composition of the present invention, tin oxide (c) containing antimony oxide is used in order to impart conductivity to the obtained coating film. As the tin oxide (c), tin oxide is a main component, and antimony oxide is 0.1 to 0.1%.
Those containing 20% by weight are preferable. Further, if the particle size is small, there is no effect on improving the conductivity, and if it is large, the visible light is scattered and the transparency of the obtained coating film is reduced, so the particle size is limited to 0.01 to 0.4 μm.

When the content of tin oxide (c) in the conductive coating composition of the present invention is low, the conductivity of the coating film obtained is low, and when it is high, the transparency of the coating film obtained is low. Therefore, it is limited to 50 to 500 parts by weight with respect to 100 parts by weight of the (meth) acrylate compound (a).

The photopolymerization initiator (d) used in the present invention is one which decomposes by ultraviolet rays or visible light to generate both an acid component and a radical component to polymerize both an epoxy group and an acrylate group. Yes, for example, the general formula A
r ₃ S ⁺ MX ⁻ _n (in the formula, Ar is an aryl group, M is a metal atom such as boron, phosphorus, arsenic, and antimony, X is a halogen atom, and n is an integer of 1 to 6). Included are the triarylsulfonium salts represented. M
X ^- _n is, for example, BF ^- ₄ , PF ^- ₆ , AsF
^{_{- 6, SbF - 6, SbCl}} - 6 , and the like.

Specific examples of the above-mentioned triarylsulfonium salt include triphenylsulfonium salt, tris (4-methoxyphenyl) sulfonium salt, 2- (diphenylsulfonio) phenylphenyl sulfide salt, and 3
-(Diphenylsulfonio) phenylphenyl sulfide salt, 4- (diphenylsulfonio) phenylphenyl sulfide salt, 4- (diphenylsulfonio) phenylphenyl sulfoxide salt, 4- (diphenylsulfonio) phenylphenyl sulfonic acid, bis- [ 4- (diphenylsulfonio) phenyl] sulfide salt and the like can be mentioned.

In the conductive coating composition of the present invention, the content of the photopolymerization initiator (d) is (meth) acrylate compound (a).
And, depending on the ratio of the epoxy resin (b), to 100 parts by weight of the (meth) acrylate compound (a),
It is limited to 1 to 20 parts by weight.

In the present invention, in order to improve the dispersibility of tin oxide (c), a copolymer (e) of methyl methacrylate and a monomer represented by the general formula (I) is contained as a dispersant. . In the formula, R ¹ and R ² represent H or a methyl group, and n represents an integer of 1-10.

[0023]

[Chemical 2]

By containing the above-mentioned copolymer (e), the obtained coating film has excellent conductivity and transparency. In the conductive coating composition of the present invention, when the content of the copolymer (e) is small, the dispersion effect is low and the coating film tends to be opaque, and when the content is high, the hardness and the scratch resistance are low. With respect to 100 parts by weight of the acrylate compound (a),
Limited to 10 to 200 parts by weight.

If necessary, an ultraviolet absorber, an antioxidant, a polymerization inhibitor, etc. may be added to the conductive coating composition of the present invention.

The conductive coating composition of the present invention is prepared by adding an organic solvent to the copolymer (e) and tin oxide (c) and mixing them with each other.
It is prepared by adding the (meth) acrylate compound (a), the epoxy resin (b), the photopolymerization initiator (d) and the like and further mixing. In order to sufficiently disperse the tin oxide (c) powder in the above composition, for example, a sand mill, a ball mill, an attritor, a high-speed rotary stirring device, a triple roll or the like is used.

The conductive coating composition prepared by the above method is applied by a general method such as a spray method, a bar coating method, a doctor blade method, a dipping method or the like. Examples of the object to be applied are polyvinyl chloride, polycarbonate, polymethacrylate, AB
Examples thereof include plastic plates or sheets of S resin and the like, glass plates and the like.

[0028]

EXAMPLES Examples of the present invention will be described below. (Example 1) [Preparation of acrylate compound (a)] ε-caprolactone ring-opening polymer (manufactured by Daicel Chemical Co., Ltd., trade name "Placcel 205", number average molecular weight 530) 530 parts by weight, Separa equipped with a dropping funnel A bull flask was charged, the temperature was raised to 80 ° C. while flowing nitrogen gas, and 1 part by weight of dibutyltin laurate was added as a urethane production catalyst.
1 part of 524 parts by weight of diphenylmethane diisocyanate
The mixture was added dropwise over a period of time, and stirring was continued at 80 ° C. for 1 hour. Next, 1 part by weight of hydroquinone was added to the reaction system as a polymerization inhibitor, 232 parts by weight of 2-hydroxyethyl acrylate was added, and the mixture was further stirred for 1 hour to prepare an acrylic urethane oligomer. The weight average molecular weight of the obtained urethane oligomer was 1500.

[Preparation of Copolymer (e)] A separable flask equipped with a dropping funnel was charged with 250 parts by weight of toluene and heated to 110 ° C. while flowing a nitrogen gas. On the other hand, after preparing a mixed solution of 112.5 parts by weight of methyl methacrylate, 12.5 parts by weight of β-hydroxyethyl methacrylate, and 0.5 parts by weight of azoisobutyronitrile (polymerization initiator), after charging a dropping funnel. Then, the mixture was dropped into the separable flask at 110 ° C. for 2 hours to carry out polymerization.
Next, after lowering the separable flask to 90 ° C., a solution prepared by dissolving 2 parts by weight of azoisobutyronitrile in 20 parts by weight of toluene was placed in a dropping funnel and dropped over 2 hours,
After the completion of dropping, the polymerization was further continued at 90 ° C. for 2 hours. The weight average molecular weight of the obtained copolymer was 4,500.

[Preparation of Conductive Coating Composition] 60 parts by weight of the above-prepared copolymer, tin oxide containing antimony oxide (manufactured by Mitsubishi Metals Co., Ltd., trade name “T-1”, primary particle size 0.02 μm)
m) 230 parts by weight and 400 parts by weight of methyl ethyl ketone were charged into a ball mill and dispersed for 24 hours. Next, the acrylic urethane oligomer 20 prepared above
Parts by weight, tetraethylene glycol dimethacrylate 1
0 parts by weight, pentaerythritol tetraacrylate 2
0 parts by weight, 20 parts by weight of phenol novolac type epoxy resin (trade name "YDCN638" manufactured by Tohto Kasei Co., Ltd.), 10 parts by weight of bis- [4- (diphenylsulfonio) phenyl] sulfide bishexafluoroantimonate and 300 parts by weight of cellosolve. Part to the ball mill and add 2 more
A conductive coating composition was prepared by stirring for 4 hours.

[Preparation of Conductive Paint Coating Film] The above conductive paint composition was applied onto a transparent acrylic plate and dried to obtain a conductive paint coating film having a thickness of 3 μm after drying. The surface of this coating film was buffed by rotating a wool buff having a diameter of 30 cm at 300 rpm.

[Performance Test of Conductive Paint Coating Film] With respect to the above-mentioned conductive paint coating film, the following performance tests were conducted. (1) Surface specific resistance value Measured according to ASTM D257, and the results are shown in Table 1.
It was shown to. (2) Total Light Transmittance and Haze Value Measured according to ASTM D1003, and the results are shown in Table 1. (3) Increase in haze value after Taber test Measurement was carried out according to ASTM D1004, and the results are shown in Table 1. (4) Pencil hardness Measured according to JIS K5400, and the results are shown in Table 1.
It was shown to.

(Example 2) Tin oxide 3 containing antimony oxide
Conductivity was the same as in Example 1 except that 100 parts by weight was used and 15 parts by weight of a bisphenol type epoxy resin (trade name “Epicoat 828” manufactured by Shell Co.) was used instead of the phenol novolac type epoxy resin. A coating composition was prepared, and the coating film was subjected to a performance test for the same items as in Example 1, and the results are shown in Table 1.

(Example 3) 25 parts by weight of tetraethylene glycol dimethacrylate, 25 parts by weight of pentaerythritol tetraacrylate and a phenol novolac type epoxy resin (trade name "YDCN63" manufactured by Toto Kasei Co., Ltd.)
8 ") A conductive coating composition was prepared in the same manner as in Example 1 except that 35 parts by weight was used, and the coating film was subjected to a performance test for the same items as in Example 1 and the results were shown. The results are shown in Table 1.

(Comparative Example 1) Phenol novolac type epoxy resin (trade name "YDCN638" manufactured by Tohto Kasei Co., Ltd.)
A conductive coating composition was prepared in the same manner as in Example 1 except that the above was not added, and the coating film was subjected to a performance test for the same items as in Example 1 and the results are shown in Table 1. .

(Comparative Example 2) A conductive coating composition was prepared in the same manner as in Example 2 except that the bisphenol type epoxy resin (trade name "Epicoat 828" manufactured by Shell Co.) was not added. The coating film was subjected to a performance test for the same items as in Example 1, and the results are shown in Table 1.

[0037]

[Table 1]

[0038]

EFFECT OF THE INVENTION The conductive coating composition of the present invention is easily cured by ultraviolet rays or visible light, and the formed coating film has conductivity and is excellent in transparency and hardness. Is remarkably excellent in. Therefore, the conductive coating composition of the present invention can be applied to a wider field as compared with the conventional conductive coating.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C09D 163/00 PKE 8830-4J PKS 8830-4J 163/10 PDY 8830-4J

Claims (1)

[Claims] 1. (b) with respect to (a) 100 parts by weight of a (meth) acrylate compound having at least two or more acryloyl groups or methacryloyl groups in the molecule.
Epoxy resin having at least two epoxy groups in the molecule 10 to 100 parts by weight, (c) particle size 0.01 to
Copolymer 10 of 0.4 μm antimony oxide-containing tin oxide 50 to 500 parts by weight, (d) 1 to 20 parts by weight of a photopolymerization initiator, and (e) methyl methacrylate and a monomer represented by the general formula (I) 10 ~ 200 parts by weight of a conductive coating composition. [Chemical 1] (In the formula, R ¹ and R ² are H or a methyl group, and n is 1 to 1
Indicates an integer of 10. )