JP2003138209A - Heat-resistant moistureproof insulation coating material and method for manufacturing insulation-treated electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-resistant moistureproof insulation coating material which excels in heat resistance without reducing the flexibility of a coating film even when deteriorated by heating at high temperatures, can be subjected to insulation treatment having high reliability, and furthermore can obtain an electronic part whose part number or the like is completely concealed. SOLUTION: The heat-resistant moistureproof insulation coating material comprises a polymer to be obtained by reacting a hydride of a hydroxyl group- containing polyisoprene with a polyisocyanate, a solvent, and a chromium complex salt of an azo compound, and the method for manufacturing electronic parts comprises using the above heat-resistant moistureproof insulating coation 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 coating material suitable for insulating electronic parts and having excellent heat resistance, an insulating-processed electronic part, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Electric equipment tends to be smaller and lighter and has more and more functions year by year, and mounted circuit boards mounted on various electric equipments for controlling the electric equipment have insulation treatment for the purpose of protection from moisture, dust, gas and the like. Has been done. As the insulation treatment method, a protective coating treatment using a paint such as an acrylic resin or a silicone resin is widely adopted. Such a mounting circuit board is used in a harsh environment, especially under high humidity, and is mounted and used in equipment such as a washing machine and an automobile. However, the acrylic resin coating material has a heat resistance of 80 to 100 ° C., loses its flexibility after heat deterioration, and is limited in use in applications requiring heat resistance. On the other hand, silicone resin paints have excellent heat resistance,
The flexibility after heat deterioration was good, but the material cost was high, and there was a problem in workability because the paint crusted and gelled.

Further, a part number or the like is printed on the electronic parts mounted on the mounting circuit board, and it is preferable that the moisture-proof insulating paint has a hiding property in order to hide the parts.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above problems of the prior art, is suitable for moisture-proof insulation, etc., has excellent heat resistance, and has a concealing property. It also provides an electronic component and a manufacturing method thereof.

[0005]

According to the present invention, (a) 100 parts by weight of a hydride of a hydroxyl group-containing polyisoprene, (b) polyisocyanate is added to the hydroxyl group of (a) in an amount of 0.7 to 10 parts by weight of an isocyanate group. Polymer obtained by reacting at a ratio of 1.0 mol and (c) solvent 10
The present invention relates to a heat-resistant and moisture-proof insulating coating material containing 1000 parts by weight, an electronic component insulated with this coating material, and a method for producing an insulating-treated electronic component in which the coating material is applied to the electronic component and dried.

The hydrogenated product of (a) hydroxyl group-containing polyisoprene used in the present invention has a hydroxyl group in the molecule or at the terminal of the molecule, and the number average molecular weight is usually 500 to 10,000,
It is preferably in the range of 1,000 to 5,000. As this commercially available product, for example, trade name Epol (made by Idemitsu Petrochemical Co., Ltd.) can be mentioned.

The polyisocyanate (b) used in the present invention is an isocyanate compound having two or more isocyanate groups in one molecule, and includes tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, diphenyl sulfone diisocyanate, Triphenylmethane diisocyanate, hexamethylene diisocyanate,
3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 3-isocyanate ethyl-3,5,5-trimethylcyclohexyl isocyanate, 3-isocyanate ethyl-3,5,5-triethylcyclohexyl isocyanate, diphenylpropane diisocyanate, phenylene Polyisocyanates such as diisocyanate, cyclohexylylene diisocyanate, 3,3'-diisocyanate propyl ether, triphenylmethane triisocyanate, diphenyl ether-4,4'-diisocyanate, etc. Phenomers, oximes, imides, and mercaptas obtained by trimerization or trimerization or isocyanates thereof Compounds, alcohols, ε-caprolactam, ethyleneimine, α-pyrrolidone, diethyl malonate, sodium bisulfite, compounds blocked with boric acid and the like, a terminal isocyanate group derived from the polyisocyanate such as carbodiimide-modified diphenylmethane diisocyanate And the like.

The polyisocyanate of the component (b) of the present invention is reacted with the component (a) at a ratio such that the isocyanate group is in the range of 0.7 to 1.0 mol with respect to 1 mol of the hydroxyl group of the component (a). When the isocyanate group exceeds 1.0 mol, the isocyanate group remains, which is not preferable from the viewpoint of stability of the paint, and when it is less than 0.7 mol, the molecular weight does not increase.

The solvent (c) used in the present invention is a ketone solvent such as acetone or methyl ethyl ketone, toluene,
Aromatic solvents such as xylene, ester solvents such as ethyl acetate and butyl acetate, alcohol solvents such as ethanol and butanol, paraffin solvents such as paraffin oil and naphthene oil, petroleum solvents such as mineral terpenes and naphtha. is there.

The compounding amount of the solvent as the component (c) is determined according to the viscosity of the coating composition which is related to workability, but is 10 to 1000 parts by weight based on 100 parts by weight of the hydride of the (a) hydroxyl group-containing polyisoprene. Parts, preferably 20 to 500 parts by weight.

In the present invention, a filler, a modifier, a defoaming agent, a coloring agent, an adhesiveness-imparting agent and the like can be optionally added to the coating composition.

Examples of the filler include finely powdered silicon oxide, magnesium oxide, aluminum hydroxide, calcium carbonate and the like, and usually (a) 0.01 to 100 parts by weight per 100 parts by weight of a hydride of a hydroxyl group-containing polyisoprene. Parts can be added.

As the modifier, for example, organic acid metal salts such as manganese naphthenate and manganese octenoate can be used for improving the drying property, and usually 0.01 to 10 parts by weight is added to 100 parts by weight of the coating material. can do.

Examples of the defoaming agent include known defoaming agents such as silicone oils, fluorine oils, and polycarboxylic acid polymers.
001 to 5 parts by weight can be added.

Examples of the colorant include known inorganic pigments, organic pigments, organic dyes, and the like, which are mixed depending on the desired color tone. You may use these in combination of 2 or more types. Usually, the amount of these pigments and dyes added can be 0.01 to 50 parts by weight with respect to 100 parts by weight of the coating material.

As the colorant for imparting the hiding property to the moisture-proof insulating coating, bis [1-[(2-hydroxy-4-nitrophenyl) azo] -2-naphthanolate], chromium complex salt, [1-[( 2-hydroxy-4-nitrophenyl) azo] -2-naphthanolate], [1-[(2-hydroxy-
Chromium complex salts of azo compounds such as 5-nitrophenyl) azo] -2-naphthanolate] and chromium complex salts are preferably used. As a commercial product, VALIFAST BLACK
3804, VALIFAST BLACK 3820
(Trade name, manufactured by Orient Chemical Industry Co., Ltd.) and the like.

The tackifier is easily dissolved in a solvent and has a solid softening point of 50 to 180 ° C. at room temperature.
More preferably, a hydrogenated rosin-based resin at 60 to 170 ° C., an alicyclic saturated hydrocarbon resin, and the like are included, and usually 10 to 100 parts by weight is added to 100 parts by weight of the hydride of (a) hydroxyl group-containing polyisoprene. be able to.

The electronic parts insulated by using the heat-resistant and moisture-proof insulating paint according to the present invention include microcomputers, transistors,
Examples thereof include capacitors, resistors, relays, transformers, etc., and mounting circuit boards on which these are mounted, and lead wires, harnesses, film substrates, etc. joined to these electronic components can also be included.

As a method for producing an electronic component which is insulated using the heat-resistant and moisture-proof insulating coating material according to the present invention, there are commonly known methods such as a dipping method, a brush coating method, a spray method and a wire drawing coating method. May be applied to the electronic component and dried.

[0020]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto. In the present invention,
Unless otherwise specified, those expressed as "parts" are parts by weight.

Example 1 Epole (trade name of Idemitsu Petrochemical Co., hydride of hydroxyl group-containing polyisoprene) was placed in a 1-liter four-necked flask.
80 parts, xylene 280 parts and tolylene diisocyanate 40 parts were mixed and stirred and reacted at 70 ° C. for 3 hours. Then, the synthesis temperature was lowered to 50 ° C., 100 parts of ethyl alcohol was added, and the mixture was reacted at 50 ° C. for 1 hour to obtain a varnish A.

Example 2 Varnish C obtained in Example 1 in a 1 liter four-necked flask
250 parts of hydrogenated rosin resin (softening point 80 ° C., trade name of Arakawa Chemical Industry Co., Ltd., ester gum HP) were added, and stirred at room temperature to obtain a uniform solution varnish B.

Example 3 Varnish C obtained in Example 2 in a 1 liter four-necked flask
500 parts, chromium complex salt of azo compound (trade name of Orient Chemical Industry Co., Ltd., ester gum HPVALIFAST B
LACK 3804) (5 parts) was added, and the mixture was stirred and dissolved at room temperature to obtain a uniform solution varnish C.

Comparative Example 1 214 parts of butyl methacrylate, 25 parts of butyl acrylate
And 150 parts of toluene were added to a 1-liter four-necked flask, and the temperature was raised to 90 ° C. while maintaining the temperature while passing nitrogen gas. Polymerization was carried out while dropwise adding a solution in which 200 parts of butyl methacrylate, 21 parts of butyl acrylate, and 3 parts of azobisisobutyronitrile were dissolved for 2 hours. Then, the temperature was raised to 110 ° C., the temperature was kept for 2 hours to complete the polymerization, and then cooled. When the temperature reached 50 ° C., 200 parts of toluene was added to 1
After stirring for 0 minute, a uniform solution varnish D was obtained.

Comparative Example 2 281 parts of G-2000 (trade name of Nippon Soda Co., Ltd., hydroxyl group-containing polybutadiene), 280 parts of xylene, and 40 parts of tolylene diisocyanate were mixed and stirred in a 1-liter four-necked flask, and the mixture was stirred at 70 ° C. for 3 hours. It was made to react. Then, lower the synthesis temperature to 50 ° C and add 100 parts of ethyl alcohol to 50 ° C.
And reacted for 1 hour to obtain Varnish E.

Comparative Example 3 Varnish C obtained in Example 2 in a 1-liter four-necked flask
500 parts and 5 parts of triphenylmethane dye (trade name, manufactured by Orient Chemical Industry Co., Ltd., OIL BLUE 613) were added and stirred and dissolved at room temperature to obtain a uniform solution varnish F.

The varnishes A to F obtained above were used as a tin plate (50 × 180 × 0.25) for the pencil hardness and flexibility tests.
mm) and a copper plate (50 × 100 × 1.
6 mm) and dried at 80 ° C for 2 hours to 20 μm
A coating film of Then, this coating film was left in a constant temperature bath at 125 ° C., and the pencil hardness, the flexibility and the adhesion to copper were measured every time. The results are shown in Table 1.

The varnishes A to F were applied to a glass plate (200 × 100 × 2 mm) for the hiding test, and the varnishes were applied at 80 ° C. for 2 hours.
It was dried for an hour to form a coating film of 20 μm. Then, this coating film was measured in accordance with "7.3.2 Hiding power sample comparison method" in JIS K5400 "General paint test method". The results are shown in Table 1.

[0029]

[Table 1]

[0030]

The coating film of the heat-resistant and moisture-proof insulating paint of the present invention is
Even if it is deteriorated by heating at a high temperature, its flexibility does not decrease, and it has excellent heat resistance. As a result, it is possible to obtain a highly reliable insulating-processed electronic component. In addition, the coating film of the heat-resistant and moisture-proof insulating coating material of the present invention is excellent in hiding property and can completely hide the product number of electronic parts.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J038 DG191 DG271 DG281 DG291                       DG301 JB16 JC38 KA06                       KA08 NA04 NA07 NA12 NA14                       NA21 PA18 PB09                 5G305 AA11 AB24 AB26 BA09 CA08                       CA18 CB27 CD01 CD04 CD20

Claims (5)

[Claims] (1) 100 parts by weight of a hydride of a hydroxyl group-containing polyisoprene, and (b) a polyisocyanate containing 0.7-1.
A heat-resistant moisture-proof insulating coating material comprising a polymer obtained by reacting in a proportion of 0 mol and (c) a solvent of 10 to 1000 parts by weight. 2. The heat-resistant moisture-proof insulating coating composition according to claim 1, further comprising at least one selected from the group consisting of a filler, a modifier, a defoaming agent, a colorant and an adhesiveness-imparting agent. 3. The heat-resistant moisture-proof insulating coating material according to claim 2, wherein the coloring agent is a chromium complex salt of an azo compound. 4. An electronic component that has been insulation-treated with the heat-resistant and moisture-proof insulating coating composition according to claim 1. 5. A method for producing an insulation-treated electronic component according to claim 4, wherein the heat-resistant moisture-proof insulating coating composition according to any one of claims 1 to 3 is applied to an electronic component and dried.