JP2003160746A - Photo-curable moisture-proof insulation coating and method of manufacturing moisture-proof insulated electronic part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photo-curable moisture-proof insulation coating excellent in flexibility, moisture resistance and reinforcing property, and capable of being treated in a short time, also provide and a method of manufacturing a moisture- proof insulated electronic part coated and cured therewith. <P>SOLUTION: The coating contains (A) a photocurable terminal acryloxypolybutadiene or terminal methacryloxypolybutadiene having a number average molecular weight of from 300 to 10,000 and a hydrogenation rate of ≥90%, (B) a trimethylolpropane trimethacrylate, (C) a photopolymerization initiator and (D) γ-methacryloxypropyltriethoxysilane. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a photocurable moisture-proof insulating coating suitable for insulation and the like, and a method for producing a moisture-proof insulated electronic component using the same.

[0002]

2. Description of the Related Art Conventionally, a mounting circuit board and a hybrid I
Electronic components such as C (integrated circuit) are printed with a wiring diagram on a substrate such as glass epoxy, paper phenol, and alumina ceramic, and various components such as a microcomputer, a resistor, and a capacitor are mounted on them. Insulation is applied to protect from dust. As the insulation treatment method, a protective coating treatment using a paint such as an acrylic resin, a silicone resin, a phenol resin or an epoxy resin is widely adopted. Such a mounting circuit board and a hybrid IC are used under a harsh environment, particularly under high humidity, and are mounted and used in equipment such as an automobile and a washing machine.

[0003]

However, since the coating material is heat-curable, a high temperature and long-time treatment is required to completely cure the coating material and obtain an insulating effect. On the other hand, an ultraviolet curable resin coating composition that can be cured in a short time, for example, in a few seconds to a few minutes has been developed, but a coating material having sufficient flexibility and moisture resistance has not yet been obtained. In addition, a portion such as a lower portion of the mounted component which is not irradiated with ultraviolet rays is in a liquid state and is in an uncured state, and there is a possibility that reliability of the electronic component is deteriorated. Furthermore, the strength of the resin coating is weak, and there is a possibility that the reinforcing property with respect to the base material is not sufficient. The present invention solves the above-mentioned problems of the prior art, can be treated for a short time, and has flexibility, moisture resistance, and a photocurable moisture-proof insulating coating material for producing a coating material having excellent reinforcing properties, and applying the same.
It is an object of the present invention to provide a method for manufacturing a moisture-proof insulated electronic component that cures.

[0004]

The present invention provides (A) a photocurable terminal acryloxypolybutadiene or terminal methacryloxypolybutadiene having a number average molecular weight of 300 to 10,000 and a hydrogenation rate of 90% or more, (B). ) A photocurable moisture-proof insulating coating containing trimethylolpropane trimethacrylate, (C) a photopolymerization initiator and (D) γ-methacryloxypropyltriethoxysilane, and a moisture-proof insulating coating and curing the coating on an electronic component. To a method of manufacturing the electronic components described above.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The photocurable terminal acryloxypolybutadiene or terminal methacryloxypolybutadiene (A) used in the present invention is obtained by reacting terminal hydroxypolybutadiene having a hydrogenation rate of 90% or more with polyisocyanate, It is an acryl-modified hydrogenated polybutadiene resin having a number average molecular weight of 300 to 10,000 obtained by reacting with hydroxyethyl acrylate or hydroxyethyl methacrylate. The number average molecular weight of this resin is 300 to 10,000, preferably 500 to 10,000.
5,000, hydrogenation rate is 90% or more, preferably 95
% Or more. When the number average molecular weight is less than 300, the film-forming property is poor, and when it exceeds 10,000, the viscosity is high and the workability is poor. On the other hand, when the hydrogenation rate is less than 90%, the flexibility of the resulting coating film after heat deterioration deteriorates and the heat resistance deteriorates.
As this commercially available product, trade name TEAI-made by Nippon Soda
2000, TEAI-3000 and the like can be mentioned, and these can be used alone or in combination of two or more kinds.

From the viewpoint of resin hardness and compatibility, the amount of trimethylolpropane trimethacrylate (B) used in the present invention is preferably in the range of 1 to 20 parts by weight with respect to 100 parts by weight of the component (A). The range of 5 to 10 parts by weight is more preferable.

The photopolymerization initiator used in the present invention includes benzyl dimethyl ketal, benzoin, benzoin ethyl ether, benzoin propyl ether, benzoin phenyl ether and other benzoin ethers, benzoin thioethers, benzophenone, acetophenone, 2
-Ethylanthraquinone furoine, benzoin ether Michler's ketone, decylnothioxanthone chloride and the like can be mentioned, and these can be used alone or in combination of two or more. The mixing ratio of these photopolymerization initiators is preferably 0.01 to 10 parts by weight, and 0.1 to 5 parts by weight, based on 100 parts by weight of the component (A), from the viewpoint of curing rate and film-forming property.
A range of parts by weight is more preferred.

The compounding ratio of γ-methacryloxypropyltriethoxysilane used in the present invention is 1 based on 100 parts by weight of the component (A) because of its adhesiveness to a glass substrate.
-20 parts by weight is preferable, and 5-10 parts by weight is more preferable.

The photocurable moisture-proof insulating coating material of the present invention can be obtained by blending the above-mentioned components (A), (B), (C) and (D) and heating and dissolving them. Further, the photocurable moisture-proof insulating coating material according to the present invention, if necessary, a crosslinkable monomer,
A polymerization inhibitor or the like can be added.

Examples of the crosslinkable monomer include styrene, vinyltoluene, α-methylstyrene, ρ-tert-butylstyrene, chlorostyrene, divinylbenzene, diallylphthalate, 2-hydroxyoxymethacrylate and 2-hydroxyoxymethacrylate. , Methylmethacrylate, ethylmethacrylate, laurylmethacrylate, monofunctional methacrylic acid ester such as a reaction product of methacrylic acid and Cardura E-10 (trade name of glycidyl ester of higher fatty acid, manufactured by Shell Chemical Co., Ltd.), ethylene glycol dimethacrylate, Bifunctional methacrylic acid esters such as diethylene glycol dimethacrylate and 1,6-hexanediol dimethacrylate, methyl acrylate, ethyl acrylate, lauryl acrylate, 2-hydro Oxyethyl acrylate, 2-
Monofunctional acrylic acid ester such as hydroxypropyl acrylate, a reaction product of acrylic acid and cardura E-10, and bifunctional acrylic acid such as ethylene glycol diacrylate, diethylene glycol diacrylate and 1,6-hexanediol diacrylate. Esters and the like are used, and these can be used alone or in combination of two or more kinds.

As the polymerization inhibitor, quinones such as hydroquinone, paratertiary butyl catechol and pyrogallol, and other commonly used ones can be used.

Electronic components such as mounted circuit boards and hybrid ICs, which are moisture-proof insulated using the photocurable moisture-proof insulating coating material according to the present invention, are manufactured by a generally known brush coating method. This coating material may be applied and cured on the electronic component by a dipping method (dip method), a spray method, or the like. Curing of the coating film after coating is performed by ultraviolet irradiation.

[0013]

EXAMPLES The present invention will now be described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Those expressed as "parts" indicate parts by weight. Example 1 TE-2000 (Nippon Soda Co., Ltd., acrylic modified polybutadiene resin, number average molecular weight: about 1,000) 90
Part, 10 parts of trimethylolpropane trimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.), 2.5 parts of benzyl dimethyl ketal and 5 parts of γ-methacryloxypropyltriethoxysilane were mixed and stirred to obtain a coating material A.

Comparative Example 1 TE-2000 (manufactured by Nippon Soda Co., Ltd., acrylic modified polybutadiene resin, number average molecular weight: about 1,000) 90
Part, 20 parts of trimethylolpropane trimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.), 2.5 parts of benzyl dimethyl ketal and 5 parts of γ-methacryloxypropyltriethoxysilane were mixed and stirred to obtain a coating material B. Comparative Example 2 TE-2000 (Nippon Soda Co., Ltd., acrylic modified polybutadiene resin, number average molecular weight: about 1,000) 10
A coating material C was obtained by mixing and stirring 0 parts, 2.5 parts of benzyl dimethyl ketal and 5 parts of γ-methacryloxypropyltriethoxysilane.

The coating materials A to C obtained above were placed in a glass test tube, allowed to stand at room temperature for 24 hours, and the resin state was observed to evaluate transparency (whether there is cloudiness). Further, these paints were applied to a glass plate so as to have a thickness of 100 μm, and irradiated with a UV irradiation device manufactured by Nippon Battery Co., Ltd. so that the total irradiation amount was 2400 mJ / cm ² at an irradiation output of 120 W / cm and the test piece It was created and evaluated for the presence or absence of surface tack by finger touch, and an adhesiveness (cross-cut) test was performed. In addition, paint on the glass plate 5
It was applied so as to have a thickness of m and irradiated with a total irradiation dose of 5000 mJ / cm ² at an irradiation output of 120 W / cm to prepare a test piece, and the resin hardness was measured with a hardness meter (Shore A).

As is clear from Table 1, TE-2000
A composition in which 10 parts of trimethylolpropane trimethacrylate is substituted

Example 1 is a composition in which 20 parts of trimethylolpropane trimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) was substituted.

[Comparative Example 1] and a composition not substituted with trimethylolpropane trimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.)

Compared to Comparative Example 2, the adhesiveness to the glass substrate is excellent and the resin hardness is also improved.

[0017]

[Table 1]

[0018]

The photocurable moisture-proof insulating coating material according to the present invention is
Trimethylolpropane trimethacrylate which is a trifunctional methacrylic acid ester having a part of the photocurable terminal acryloxypolybutadiene or terminal methacryloxypolybutadiene having a number average molecular weight of 300 to 10,000 and a hydrogenation rate of 90% or more. By replacing with, it is a paint that has high adhesiveness with glass, thereby exhibiting excellent properties in moisture resistance evaluation, and the resin hardness is improved. It is a paint showing excellent characteristics, and it is possible to manufacture an electronic component with improved reliability by this paint.

Claims (2)

[Claims] 1. (A) Number average molecular weight of 300 to 10,0
00, a photocurable terminal acryloxypolybutadiene or terminal methacryloxypolybutadiene having a hydrogenation rate of 90% or more, (B) trimethylolpropane trimethacrylate, (C) photopolymerization initiator and (D) γ-methacryloxypropyl A photo-curable moisture-proof insulating coating material containing triethoxysilane. 2. A method for producing a moisture-proof insulated electronic component, which comprises applying the photocurable moisture-proof insulating material according to claim 1 to an electronic component and curing the same.