JP2006016437A - Moisture-proof insulation coating material, insulated electronic part and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-resistant moisture-proof insulation coating material giving an electronic part subjected to an insulation treatment, having excellent heat-resistance to resist the lowering of the flexibility of the coating film even by a thermal deterioration test at a high temperature and high reliability and having a completely masked item code, etc., without using an azo dye. <P>SOLUTION: The moisture-proof insulation coating material contains (A) a copolymer having a glass transition temperature of 0-50°C and obtained by polymerizing (a) 50-100 pts. wt. of butyl methacrylate and (b) 0-50 pts. wt. (the sum of (a) and (b) is 100 pts. wt.) of an alkyl acrylate/methacrylate having an 8-15C alkyl group and optionally (c) ≤5 pts. wt. (based on 100 pts. wt. of the above monomers) of other monomers, (B) 10-1,000 pts. wt. of a solvent and (C) 0.01-70 pts. wt. of an azine dye. The invention further provides an electronic part produced by using the moisture-proof insulation coating material and its production method. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a moisture-proof insulating paint suitable for insulation of electronic components and excellent in concealment using an azine dye, an insulated electronic component, and a method for producing the same.

  Electrical devices tend to be smaller and lighter and more multifunctional year by year, and the mounting circuit boards mounted on various electrical devices that control them are subjected to insulation treatment for the purpose of protecting them from moisture, dust, gas, and the like. In this insulation treatment method, a protective coating treatment with a paint such as an acrylic resin, a urethane resin, or a silicone resin is widely employed. Such a mounting circuit board is used in a harsh environment, particularly under high humidity, and is used by being mounted on a device such as a washing machine, an automobile, or a flat panel display. When the moisture-proof insulating paint is applied to the mounting circuit board, there is a problem that the part number of the electronic component mounted on the mounting circuit board is not concealed by printing. Was made. However, in recent years, the use of azo compounds has become a problem due to environmental problems.

JP 2004-99761 A

  The present invention solves such problems of the prior art, is suitable for moisture-proof insulation, etc., has excellent heat resistance, and also has a concealing property without using azo dyes due to environmental problems, insulation treatment An electronic component and a method for manufacturing the same are provided.

The present invention relates to the following inventions.
<1> Polymerization with (A) (a) 50 to 100 parts by weight of butyl methacrylate, (b) 0 to 50 parts by weight of acrylic acid / methacrylic acid alkyl ester having 8 to 15 carbon atoms in the alkyl group as a total amount of 100 parts by weight Or (c) a copolymer having a glass transition temperature of 0 to 50 ° C. obtained by polymerizing 5 parts by weight or less of other monomers with respect to 100 parts by weight of these monomers together with these monomers,
(B) It relates to a moisture-proof insulating paint comprising 10 to 1000 parts by weight of a solvent and (C) 0.01 to 70 parts by weight of an azine dye.
<2> The moisture proof according to <1>, further comprising at least one selected from an additive consisting of a filler, a modifier, an antifoaming agent, and a tackifier, and used for a mounted circuit board. It relates to insulating paint.
<3> The present invention relates to an electronic component that is insulated using the moisture-proof insulating paint described in <1> to <2> above.
<4> The present invention relates to a method for producing an insulated electronic component according to <3>, wherein the moisture-proof insulating paint according to <1> to <2> is applied to an electronic component and dried.

  The coating film of the heat-resistant and moisture-proof insulating coating of the present invention is excellent in heat resistance without decreasing its flexibility even when heated and deteriorated at high temperatures, whereby a highly reliable insulated electronic component can be obtained. In addition, the coating film of the heat-resistant and moisture-proof insulating paint of the present invention has excellent concealability without using an azo dye due to environmental problems, and can completely conceal the part number of the electronic component.

  The component (A) used in the present invention is a copolymer obtained from the above monomer having a glass transition temperature of 0 to 50 ° C. If the glass transition temperature is less than 0 ° C., the coating film has low hardness. After drying, the coating film remains sticky, and when it exceeds 50 ° C., the coating film becomes hard and is easily broken by a flexibility test.

As the (b) acrylic acid / methacrylic acid alkyl ester used in the present invention, a compound having an alkyl group having 8 to 15 carbon atoms is used, such as 2-ethylhexyl acrylate, lauryl acrylate, 2-ethylhexyl methacrylate, methacrylic acid. Examples thereof include lauryl acid, and these may be used alone or in combination of two or more.
(B) The amount of acrylic acid / methacrylic acid alkyl ester is 0 to 50 parts by weight, preferably 0 to 45 parts by weight, and more preferably 0 to 40 parts by weight. When the blending amount of acrylic acid / methacrylic acid alkyl ester exceeds 50 parts by weight, the coating film remains sticky after drying.

  The monomer of the component (c) used in the present invention is (A) (a) 50 to 100 parts by weight of butyl methacrylate, (b) acrylic acid / methacrylic acid alkyl ester 0 to 8 having 15 to 15 carbon atoms in the alkyl group. It is sufficient if it can be copolymerized with 50 parts by weight, and without limitation, acrylic acid, methacrylic acid and the like may be mentioned. These may be used alone or in combination of two or more.

The solvent (B) used in the present invention includes ketone solvents such as acetone and methyl ethyl ketone, aromatic solvents such as toluene and xylene, ester solvents such as ethyl acetate and butyl acetate, alcohol solvents such as ethanol and butanol, Paraffinic solvents such as paraffin oil and naphthenic oil, and petroleum solvents such as mineral terpenes and naphtha.
(B) Although the compounding quantity of the solvent which is a component is determined according to the viscosity of the coating material relevant to workability | operativity, it is 10-1000 weight part with respect to 100 weight part of (A) component, 15-800 weight part Is preferable, and 20-500 weight part is more preferable.

  The (C) azine dye used in the present invention is C.I. I. Solvent Black 5, C.I. I. Solvent Black 7 or the like is preferably used. You may use these in combination of 2 or more types. As a commercial item, OIL BLACK No. 5, OIL OPLAS BLACK BS (trade name, manufactured by Orient Chemical Industry Co., Ltd.) and the like. Usually, the addition amount of these pigments and dyes is 0.01 to 70 parts by weight, preferably 0.1 to 60 parts by weight, and more preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the paint.

  In the present invention, a filler, a modifier, an antifoaming agent, a tackifier, and the like can be optionally added to the paint as necessary. Examples of the filler include fine powder silicon oxide, magnesium oxide, aluminum hydroxide, calcium carbonate and the like. As the modifier, for example, organic acid metal salts such as manganese naphthenate and manganese octenoate can be used to improve the drying property. Examples of the antifoaming agent include known antifoaming agents such as silicone oil, fluorine oil, and polycarboxylic acid polymer. As the tackifier, a hydrogenated rosin resin, an alicyclic saturated hydrocarbon resin, etc., which is easily dissolved in a solvent and has a softening point of solid at room temperature, preferably 50 to 180 ° C., more preferably 60 to 170 ° C. Is mentioned.

  Examples of electronic components insulated using the heat-resistant and moisture-proof insulating paint according to the present invention include a microcomputer, a transistor, a capacitor, a resistor, a relay, a transformer, and a mounting circuit board on which these are mounted. Bonded lead wires, harnesses, film substrates, and the like can also be included.

  As a method for producing an electronic component insulated using the heat-resistant and moisture-proof insulating coating according to the present invention, the coating is applied to the above-mentioned electronic component by a generally known method such as dipping, brushing, spraying or drawing. Apply to parts and dry.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the present invention, what is expressed as “parts” indicates parts by weight unless otherwise specified.

Comparative Example 1
140 parts of butyl methacrylate, 90 parts of lauryl methacrylate, 5 parts of methacrylic acid and 150 parts of toluene were added to a 1 liter four-necked flask, and the temperature was raised to 90 ° C. while passing nitrogen gas. Polymerization proceeded while adding dropwise a solution of 140 parts of butyl methacrylate, 90 parts of lauryl methacrylate, 5 parts of methacrylic acid and 3 parts of azobisisobutyronitrile in 2 hours. Thereafter, the temperature was raised to 110 ° C., and the temperature was kept for 2 hours to complete the polymerization, followed by cooling. When the temperature reached 50 ° C., 200 parts of toluene was added and stirred for 10 minutes to obtain a uniform solution varnish A.

Comparative Example 2
To a 1 liter four-necked flask, 500 parts of varnish A obtained in Comparative Example 1 and 5 parts of triphenylmethane dye (trade name OIL BLUE 613, manufactured by Orient Chemical Industry Co., Ltd.) are added and stirred at room temperature to obtain a uniform solution varnish B. It was.

Comparative Example 3
500 parts of varnish A obtained in Comparative Example 1, bis [1-[(2-hydroxy-4-nitrophenyl) azo] -2-naphthanolate] chromium complex (trade name, manufactured by Orient Chemical Co., Ltd.) 5 parts of VALIFAST BLACK 3804) was added and stirred at room temperature to obtain a uniform solution varnish C.

Example 1
To a 1 liter four-necked flask, 500 parts of varnish A obtained in Comparative Example 1 and 5 parts of azine dye (trade name OIL BLACK No. 5 manufactured by Orient Chemical Industries) were added and stirred at room temperature to obtain a uniform solution varnish D. It was.

Varnishes A to D obtained above are applied to a tin plate (50 × 180 × 0.25 mm) for coating film appearance, pencil hardness and flexibility test, and to a copper plate (50 × 100 × 1.6 mm) for adhesion test. Each was coated and dried at 80 ° C. for 2 hours to form a 20 μm coating film, and pencil hardness, flexibility and adhesion to copper were measured. The results are shown in Table 1.
Varnishes A to D were applied to a glass plate (200 × 100 × 2 mm) for a concealment test and dried at 80 ° C. for 2 hours to form a 20 μm coating film. Subsequently, this coating film was measured according to “7.3.2 Hiding power sample comparison method” in JIS K5400 “Paint General Test Method”. The results are shown in Table 1.

Claims (4)

(A) (a) 50 to 100 parts by weight of butyl methacrylate, (b) obtained by polymerizing 0 to 50 parts by weight of an acrylic acid / methacrylic acid alkyl ester having 8 to 15 carbon atoms in the alkyl group as a total amount of 100 parts by weight Or (c) a copolymer having a glass transition temperature of 0 to 50 ° C. obtained by polymerizing 5 parts by weight or less of other monomers with respect to 100 parts by weight of these monomers together with these monomers,
(B) A moisture-proof insulating coating comprising 10 to 1000 parts by weight of a solvent and (C) 0.01 to 70 parts by weight of an azine dye. The moisture-proof insulating paint according to claim 1, further comprising at least one selected from an additive comprising a filler, a modifier, an antifoaming agent, and a tackifier, and used for a mounting circuit board. An electronic component that is insulated using the moisture-proof insulating paint according to claim 1. The method for producing an insulated electronic component according to claim 3, wherein the moisture-proof insulating paint according to claim 1 is applied to the electronic component and dried.