JPH11279458A - Moisture preventing electrically insulating coating material and electric/electronic part using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a moisture preventing electrically insulating coating material excellent in flexibility and moisture resistance and capable of being finished in a short time, and to provide electric/electronic parts subjected to a moisture preventing electrically insulating treatment by using the coating material. SOLUTION: This coating material comprises; (a) 100 pts.wt. of resin obtained by reacting a hydroxy group-containing polyisoprene having a hydrogeneration ratio of >=90% with a polyisocyanate and then reacting it with a hydroxy group- containing polymerizable unsaturated monomer, (b) 0.5 to 20 pts.wt. of silane- based coupling agent, (c) 0.01 to 10 pts.wt. of photopolymerization initiator and (d) 10 to 300 pts.wt. of solvent. The other objective electric/electronic parts are subjected to a moisture preventing electrically insulating treatment by busing the coating material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture-proof insulating paint and an electric and electronic component subjected to a moisture-proof insulating treatment using the moisture-proof insulating paint.

[0002]

2. Description of the Related Art Conventionally, mounted circuit boards and hybrid ICs
The circuit is printed on glass epoxy, alumina ceramic, etc., and various electronic parts such as microcomputer, resistor, capacitor, etc. are mounted, to insulate those parts and to protect from moisture, dust, etc. Protective coating treatment with a paint such as an acrylic resin, a silicone resin, or an epoxy resin is widely performed. Such a mounted circuit board and a hybrid IC are used in a severe environment, particularly in an automobile,
It is often used in equipment that is installed in washing machines and used under high humidity.

However, since the paint is heat-curable, a high temperature treatment or a long-time treatment is required to completely cure the paint and obtain an insulating effect. On the other hand, an ultraviolet-curable resin paint capable of being cured in a short time, for example, in a few seconds to a few minutes, has been developed, but one having sufficient flexibility and moisture resistance has not yet been obtained.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and can be processed in a short time, and is excellent in flexibility and moisture resistance. It is an object of the present invention to provide an electric and electronic component that has been subjected to moisture-proof insulation treatment.

[0005]

According to the present invention, (a) a hydroxyl group-containing polyisoprene having a hydrogenation rate of 90% or more is reacted with a polyisocyanate, and then a polymerizable unsaturated monomer having a hydroxyl group is reacted. 100 parts by weight of a resin obtained by the reaction, (b) 0.5 to 20 parts by weight of a silane coupling agent, (c) 0.01 to 10 parts by weight of a photopolymerization initiator,
(D) The present invention relates to a moisture-proof insulating paint containing 10 to 300 parts by weight of a solvent, and an electric and electronic component subjected to moisture-proof insulation treatment using the moisture-proof insulating paint. The present invention also relates to electrical and electronic components that have been subjected to moisture-proof insulation treatment using the moisture-proof insulation paint.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the moisture-proof insulating paint of the present invention,
The number average molecular weight of the resin (a) is from 500 to 10,000.
0 is preferable, and 1,000 to 5,000 is more preferable. When the number average molecular weight is less than 500, the film-forming property is deteriorated, and when it exceeds 10,000, the viscosity of the coating material becomes high and the workability is poor.

The hydroxyl group-containing polyisoprene having a hydrogenation rate of 90% or more, which is a raw material of the resin as the component (a), has a hydroxyl group in a molecule or at a molecular terminal and has a hydroxyl group content of 0.1%.
6 to 1.5 meq / g, number average molecular weight of about 500 to about 10,
000 is preferable, and about 1,000 to about 5,000
Are particularly preferred. The hydroxyl group-containing polyisoprene has a hydrogenation rate of 90% or more, and commercially available products include Epole manufactured by Idemitsu Petrochemical Co., Ltd.
The hydrogenation rate is preferably 90% or more.
% Or more is more preferable. If the hydrogenation ratio is less than 90%, the flexibility of the obtained coating film after thermal deterioration is reduced, and the heat resistance is poor. In the present invention, the number average molecular weight is measured by a vapor pressure osmometry. The degree of the hydrogenation rate can be measured by an iodine value as another degree. The iodine value of the hydroxyl group-containing polyisoprene is 40%.
The following is preferable, and especially 20 or less is preferable.

Further, the polyisocyanate which is a raw material of the resin of the component (a) is used for forming a polymer by reacting with the hydroxyl group of the hydroxyl group-containing polyisoprene and the polymerizable unsaturated monomer having a hydroxyl group. For example, tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate,
Xylylene diisocyanate, diisocyanate compound such as hexamethylene diisocyanate, polyisocyanate compound such as triisocyanate compound such as triphenylmethane triisocyanate, or the isocyanate group of these polyisocyanate compounds with phenols, imides, oximes, alcohols, etc. Examples include blocked compounds, prepolymers having terminal isocyanate groups derived from the above-mentioned polyisocyanates such as carbodiimide-modified diphenylmethane diisocyanate, and these can be used alone or in combination of two or more.

Examples of the polymerizable unsaturated monomer having a hydroxyl group include an acrylate or methacrylate having a hydroxyalkyl group having 1 to 10 carbon atoms and a poly (alkyleneoxy) alkyl group having 1 to 10 carbon atoms. Specifically, acrylates having a hydroxyl group such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyhexyl acrylate, hydroxyoctyl acrylate, diethylene glycol monoacrylate, dipropylene glycol monoacrylate, hydroxyethyl methacrylate, hydroxypropyl Methacrylate, hydroxybutyl methacrylate, hydroxyhexyl methacrylate, hydroxyoctyl methacrylate, diethylene glycol Bruno methacrylate, methacrylic acid ester having a hydroxyl group such as dipropylene glycol monomethacrylate.

The method of synthesizing the resin as the component (a) may be a method of reacting an ordinary hydroxyl group with an isocyanate group, and is not particularly limited. As an example of the synthesis method, first, a hydroxyl group-containing polyisoprene and a polyisocyanate are blended and reacted to obtain a prepolymer having an isocyanate group at a molecular terminal, and then a polymerizable unsaturated monomer having a hydroxyl group is added. Let react.

The ratio of the hydroxyl groups of the hydroxyl group-containing polyisoprene to the isocyanate groups of the polyisocyanate is 1 hydroxyl group
It is preferable that the isocyanate group is 1.4 to 2.4 equivalents with respect to the equivalent weight.
It is preferable that the isocyanate group is 1.6 to 2.2 equivalents.

The ratio of the total number of hydroxyl groups of the hydroxyl group-containing polyisoprene and the hydroxyl group-containing polymerizable unsaturated monomer to the isocyanate group of the polyisocyanate is 0.7 to 0.7% per equivalent of hydroxyl group. 1.2
It is preferable that the isocyanate group is equivalent to 0.8 to 1.1 equivalent to 1 equivalent of the hydroxyl group.

The silane coupling agent of the component (b) in the present invention is represented by the general formula (I)

Embedded image (Wherein, Z is a group having a reactive double bond such as a vinyl group, a C3-10 acryloyloxyalkyl group, a C4-11 methacryloyloxyalkyl group,
R represents an alkyl group having 1 to 6 carbon atoms or an aromatic group having 6 to 22 carbon atoms). Specifically, γ-methacryloxypropyltrimethoxysilane,
γ-methacryloxypropyltriethoxysilane, γ-
Acryloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane and the like can be mentioned, and these can be used alone or in combination of two or more.

The mixing ratio of the component (b) is preferably 0.5 to 20 parts by weight, more preferably 0.7 to 15 parts by weight, based on 100 parts by weight of the component (a). It is particularly preferred that the amount be 1 to 10 parts by weight. 0.5
If the amount is less than 10 parts by weight, the resulting coating film has poor moisture resistance,
Exceeding the parts by weight reduces the flexibility.

As the photopolymerization initiator of the component (c) in the present invention, benzoin ethers such as benzoin, benzyldimethyl ketal and benzoin ethyl ether; Photopolymerization initiator, benzoin thioethers, benzophenone,
Intramolecular hydrogen abstraction type photopolymerization initiator having a thioxanthone structure such as acetophenone, 21-ethylanthraquinone, Michler's ketone, decylnothioxanthone chloride, isobutylthioxanthone, etc., and these may be used alone or in combination of two or more. Can be. The compounding ratio of the component (c) is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 8 parts by weight, based on 100 parts by weight of the component (a).
It is particularly preferred that the amount be 0.1 to 5 parts by weight. 0.01
If the groove is not grooved, the curing distance by light irradiation becomes slow, and
Exceeding parts by weight makes film formation difficult.

As the solvent of the component (d) in the present invention, aromatic solvents such as toluene and xylene are preferable from the viewpoint of solubility of the resin. The mixing ratio of the component (d) is preferably 10 to 300 parts by weight, more preferably 50 to 250 parts by weight, and more preferably 75 to 200 parts by weight based on 100 parts by weight of the component (a). Is particularly preferred. If the groove is not 10 weight parts, the viscosity is high and the workability is deteriorated. If it exceeds 300 weight parts, the coating film becomes thin and the moisture resistance may be reduced.

The moisture-proof insulating paint of the present invention is characterized in that
It is obtained by mixing predetermined amounts of the components (b), (c) and (d) and dissolving with stirring. As a method of applying this paint, generally known dipping method, spray method,
A brush coating method or the like is applied, and the coating film after application is cured by ultraviolet curing.

The moisture-proof insulating coating material of the present invention may contain, if necessary, a crosslinkable monomer such as styrene and vinyl toluene, a radical polymerization initiator such as benzoin peroxide and methyl ethyl ketone peroxide, and a naphthenic acid such as iron, cobalt and manganese. Hardening accelerators such as salts and octenoates, and polymerization inhibitors such as hydroquinone and p-tert-butylcatechol can be added.

[0019]

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. [Synthesis of Resin A] Epol (hydroxyl-containing polyisoprene hydride: number average molecular weight: 2,500, hydroxyl group content: 0.91 meq / g, hydrogenation rate: 9)
330 parts by weight (7%, iodine value: 12, Idemitsu Petrochemical Co., Ltd.) and 90 parts by weight of diphenylmethane diisocyanate were added, and the mixture was stirred under a nitrogen atmosphere and reacted at 80 ° C. for 2 hours. Next, 36 parts by weight of hydroxyethyl acrylate was added dropwise over 1 hour, and the mixture was reacted for another 2 hours to obtain resin A.
(Number average molecular weight: 3,500, hydrogenation rate: 95%).

Example 1 100 parts by weight of resin A, 4 parts by weight of γ-methacryloxypropyltrimethoxysilane, benzyl dimethyl ketal 2
Parts by weight and 150 parts by weight of xylene were mixed and stirred.
I got

Example 2 A coating material B was obtained in the same manner as in Example 1 except that 4 parts by weight of vinyltriethoxysilane was used instead of γ-methacryloxypropyltrimethoxysilane.

Comparative Example 1 TE-2000 (Nippon Soda) instead of Resin A of Example 1
Co., Ltd., a resin obtained by reacting a reaction product of 1,2-polybutadiene having a terminal hydroxyl group with tolylene diisocyanate with hydroxyethyl acrylate, number average molecular weight 1
Coating C was obtained in the same manner as in Example 1 except that 100 parts by weight of (2,000) was used.

The coatings A to C obtained in the above Examples and Comparative Examples were applied to a comb-shaped electrode (electrode spacing 0.3) on an alumina ceramic substrate.
m, electrodes made of Ag-Pb) by an immersion method, and irradiated with UV rays from a mercury lamp with an irradiation capacity of 50 W / cm manufactured by Ushio Inc. from an irradiation distance of 10 cm for 120 seconds to prepare a test piece for a moisture resistance test. And tested for moisture resistance. Also, JlSC
A test piece for a flexibility test was prepared according to 2103, cured under the above curing conditions, left at 125 ° C. for 240 hours, and tested for flexibility. Table 1 shows the results. still,
The moisture resistance was measured by applying a DC voltage of 15 V to the test piece for humidity resistance test, leaving the test piece in a thermo-hygrostat at 60 ° C. and 95% RH. It was measured.

[0024]

[Table 1]

[0025]

The moisture-proof insulating paint according to the present invention has excellent flexibility and moisture resistance, and can be processed in a short time because it uses an ultraviolet curable resin. Electric and electronic components insulated by this paint have excellent reliability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C08F 299/06 C08F 299/06

Claims (2)

[Claims] (1) 100 parts by weight of a resin obtained by reacting (a) a hydroxyl group-containing polyisoprene having a hydrogenation rate of 90% or more with a polyisocyanate, and then reacting a polymerizable unsaturated monomer having a hydroxyl group. , (B) 0.5 to 20 parts by weight of a silane coupling agent, (c) 0.01 to 10 parts by weight of a photopolymerization initiator, and (d) 10 to 300 parts by weight of a solvent. Insulating paint. 2. An electric and electronic component which has been subjected to moisture-proof insulation treatment using the moisture-proof insulation paint according to claim 1.