JP2000178477A - Moisture-proof insulation treatment composition, and electric and electronic parts using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a moisture-proof, insulation treatment composition that gives cured products suitable for moisture-proofing and insulation and shows excellent workability, heat resistance, flame retardancy and heat dissipation by blending the composition with the hydride of a hydroxyl group-bearing liquid polyisoprene, polyisocyanate, hydrated alumina, silicon nitride and phosphoric ester. SOLUTION: The objective composition is constituted by containing (A) a hydrogenated product of hydroxyl group-bearing liquid polyisoprene, (B) polyisocyanate, (C) hydrated alumina (suitably with particle sizes of 0.1-100 μm), (D) silicon nitride (suitably with particle size of 0.1-50 μm) and (E) a phosphoric ester (for example, tricresyl phosphate). The component A preferably has a hydroxyl group content of 0.8-1.3 meq/g, the number-average molecular weight of 1,000-5,000. The proportion of the component B is preferably adjusted so that the isocyanate in the component B may become 0.9-1.1 equivalent per the hydroxyl group in the component A. In the composition, the content of the component C is preferably 25-75 wt.%, the component D is 5-10 wt.% and the component E is 5-13 wt.%.

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 composition and an electric / electronic component subjected to moisture-proof insulating treatment using the composition.

[0002]

2. Description of the Related Art Electrical equipment tends to become smaller, lighter and more multifunctional year by year, and mounted circuit boards mounted on various electric equipment for controlling multifunction are insulated to protect them from moisture, dust, and the like. ing. As this insulating treatment, a protective coating treatment with a paint such as an acrylic resin or a silicone resin, or a casting treatment with a urethane resin, an epoxy resin, a silicone gel, or the like is widely used. Such a mounted circuit board is used under a severe environment, particularly under a high humidity, and is used by being mounted on, for example, a machine such as a washing machine and an automobile.

[0003] However, the paint cannot completely protect the pin feet of the electronic components mounted on the mounted circuit board, and has a problem of poor water resistance.
On the other hand, urethane resin and epoxy resin used for casting have excellent insulation and water resistance, but when left for a long time under high temperature conditions, the cured product becomes hard due to oxidative deterioration, and parts and mounting circuits Stress was applied to the plate and the like, cracks and peeling occurred, and there was a possibility that the reliability was reduced. Also,
Silicone gel has a cured product with low hardness and excellent heat resistance, but is expensive and has a problem in economy.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, provides a cured product suitable for moisture-proof insulation, and has excellent workability, heat resistance, flame retardancy and heat dissipation. An object of the present invention is to provide a moisture-proof insulation-treated composition and an electric / electronic component subjected to moisture-proof insulation treatment using the composition.

[0005]

SUMMARY OF THE INVENTION The present invention relates to (a) a hydride of a hydroxyl group-containing liquid polyisoprene, (b) a polyisocyanate, (c) a hydrated alumina, (d) silicon nitride and (e) a phosphate ester. The present invention relates to a moisture-proof insulation treatment composition comprising: and an electric and electronic component subjected to moisture-proof insulation treatment using the moisture-proof insulation treatment composition.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the moisture-proof insulating composition of the present invention comprises (a) a hydride of a hydroxyl group-containing liquid polyisoprene, (b) a polyisocyanate, (c) hydrated alumina, and (d) nitrided. It contains silicon and (d) a phosphoric acid ester. The hydride of the hydroxyl group-containing liquid polyisoprene as the component (a) has a hydroxyl group in a molecule or at a molecular terminal, and the content of the hydroxyl group is set to 0.6 in consideration of the properties of the cured product.
１．５1.5 meq / g, preferably 0.8-1.3 m
More preferably, it is eq / g.

The number average molecular weight of the hydroxyl group-containing liquid polyisoprene is preferably in the range of 500 to 10,000, more preferably in the range of 1,000 to 5,000. If the number average molecular weight is less than 500, the flexibility of the cured product tends to be inferior, and if it exceeds 10,000, the viscosity of the resin composition tends to be high, and the casting workability tends to be inferior. In the present invention, the number average molecular weight is measured by a vapor pressure osmometry. Commercially available products of this polymer include, for example, Ebol (trade name, manufactured by Idemitsu Petrochemical Industry Co., Ltd.).

The component (b) polyisocyanate used in the present invention is used as a curing agent for the hydride of the hydroxyl group-containing liquid polyisoprene of the component (a). Examples thereof include tolylene diisocyanate and diphenylmethane diisocyanate. , Naphthalene diisocyanate,
Xylylene diisocyanate, diphenylsulfone diisocyanate, triphenylmethane diisocyanate,
Hexamethylene isocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 3-isocyanatoethyl-3,5,5-trimethylcyclohexyl isocyanate, 3-isocyanatoethyl-3,5,5-triethylcyclohexyl isocyanate, diphenyl Propane diisocyanate,
Polyisocyanates such as phenylene diisocyanate, cyclohexylylene diisocyanate, 3,3'-diisocyanate propyl ether, triphenylmethane triisocyanate, diphenyl ether-4,4'-diisocyanate or the above isocyanates as phenols, oximes, imides, mercaptans, Alcohols, ε-caprolactam, ethyleneimine, α-pyrrolidone, diethyl malonate, sodium bisulfite, compounds blocked with boric acid, etc., carbodiimide-modified diphenylmethane diisocyanate and other polyisocyanate-derived terminal isocyanate-derived polyisocyanate groups. And the like. These can be used alone or in combination of two or more.

The mixing ratio of the polyisocyanate of the component (b) is such that the isocyanate group in the polyisocyanate is 0% with respect to the hydroxyl group of the hydride of the (a) hydroxyl group-containing liquid polyisoprene in view of the curability and properties of the composition. .7-
The equivalent is preferably 1.5 equivalents, more preferably 0.8 to 1.3 equivalents, and particularly preferably 0.9 to 1.1 equivalents. If the amount is less than 0.7 equivalent, the curability and moisture resistance tend to be inferior. If the amount exceeds 1.5 equivalents, the cured product becomes hard and the thermal shock resistance tends to decrease.

The hydrated alumina of the component (c) used in the present invention is used as a flame retardant.
It is preferable to use one having a particle diameter of 100 μm.
The mixing ratio of the hydrated alumina is preferably 15 to 85% by weight, more preferably 20 to 80% by weight, and more preferably 25 to 80% by weight, based on the viscosity and flame retardancy of the moisture-proof insulating composition. It is particularly preferred to be 75% by weight. If the compounding ratio is less than 15% by weight, the flame retardancy tends to be inferior. If the compounding ratio exceeds 85% by weight, the viscosity of the composition becomes high, and the casting workability may be deteriorated.

The silicon nitride used as the component (d) in the composition of the present invention is used for improving the thermal conductivity of the cured product. preferable. The compounding ratio of silicon nitride is preferably 1 to 20% by weight, more preferably 3 to 15% by weight in the composition from the viscosity of the insulating treatment composition,
It is particularly preferred that the content be 5 to 10% by weight. If the blending ratio is less than 1% by weight, it is not possible to obtain improved curing of the thermal conductivity of the cured product, and if it exceeds 20% by weight, the viscosity of the composition becomes high and the casting workability becomes poor.

The phosphate ester used as the component (e) in the present invention is used as a liquid flame retardant and a flexibilizing agent. Examples thereof include tricresyl phosphate, cresyl diphenyl phosphate, Examples thereof include silenyl phosphate, and one or more of these can be used. The mixing ratio of the phosphoric acid ester is preferably 1 to 20% by weight in the composition from the viewpoint of flame retardancy and moisture resistance of the insulating composition, and is preferably 3 to 1
The content is more preferably 5% by weight, particularly preferably 5 to 13% by weight. If this blending amount is less than 1% by weight, the flexibility of the cured product tends to be inferior, and 20% by weight.
If it exceeds, the moisture resistance tends to decrease.

Various additives such as a plasticizer, a tackifier, a curing accelerator, and a coloring agent may be added to the moisture-proof insulating composition of the present invention, if necessary, in usual amounts. The moisture-proof insulation treatment composition of the present invention is suitable for insulation treatment of electric and electronic equipment such as capacitors, transformers and other components, and mounted circuit boards. As the insulation treatment, the composition may be cast into an electric / electronic component by a generally known casting method and cured. Curing after casting is performed at room temperature or by heating. When performing heat curing, usually 60 to 120 ° C
It is preferred to heat at a temperature of

[0014]

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Examples 1 and 2 and Comparative Example 1 An insulating composition was prepared with the composition and the amount (parts by weight) shown in Table 1, and the properties of the cured product were measured by the following methods. It is shown in FIG. The substances used are as follows. Hydroxy group-containing liquid polyisoprene hydride: Number average molecular weight 2500, hydroxyl group content 0.90 meq / g (trade name: Epole, manufactured by Idemitsu Petrochemical Co., Ltd.) Hydroxyl group-containing 1,4-polybutadiene: number average molecular weight 28
00 (made by Idemitsu Petrochemical Industry Co., Ltd., trade name Po
lybdR45HT) Hydrated Alumina A: Most particles have a particle size of 1.0 to 1
Particles having a particle size of 00 μm Silicon nitride: SN-7 (trade name, manufactured by Denki Kagaku Kogyo Co., Ltd., average particle size: 4 μm) Phosphate ester: tricresyl phosphate Polyisocyanate: carbodiimide-modified diphenylmethane diisocyanate represented by the following formula

Embedded image (In the formula, Ph represents a paraphenylene group.)

(1) Hardness 30 g of the insulating composition was placed in a metal petri dish having a diameter of 60 mm.
After pouring and curing at 80 ° C. for 4 hours, a cured product was taken out from the metal dish to prepare a sample. Immediately after curing (initial stage) and after heat deterioration at 125 ° C. for 168 hours, each was left to a measurement temperature of 25 ° C. and measured with a Shore A hardness meter. (2) Flame retardancy A 127 × 12.7 × 2 mm test piece cured at 80 ° C. for 4 hours was prepared, and measured in accordance with the UL94 flame retardancy test method at the initial stage and after heat deterioration at 125 ° C. for 168 hours. . (3) Thermal conductivity A test piece having a diameter of 50 mm × 10 mm was prepared by curing at 80 ° C. for 4 hours, and tested with a rapid thermal conductivity meter.

[0017]

[Table 1]

[0018]

Industrial Applicability The moisture-proof insulating composition of the present invention can produce a cured product excellent in workability, heat resistance, flame retardancy and heat dissipation, thereby providing a highly reliable moisture-proof insulating treatment. Electrical and electronic components can be provided.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 AC061 DE147 DF018 ER006 EW049 FD146 GQ01 4J038 CA021 CA101 DG262 GA03 HA216 HA436 JC24 NA04 NA21 PB09

Claims (2)

[Claims] 1. A moisture-proof insulating treatment comprising (a) a hydride of a hydroxyl group-containing liquid polyisoprene, (b) a polyisocyanate, (c) hydrated alumina, (d) silicon nitride, and (e) a phosphate ester. Composition. 2. An electric and electronic component which has been subjected to moisture-proof insulation treatment using the moisture-proof insulation treatment composition according to claim 1.