RU2598861C1 - Electric insulating filling compound - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to electrically insulating kompaunds, which can be used for filling or impregnation parts of electrical machines, devices, current-conducting circuits and parts in radio engineering, electrical and electronic industries. Compound consists of diglycidyl ether of resorcinol, methyl endyc anhydride, 2-ethyl-4-methylimidazole, pulverized quartz and hydrophobic modified pyrogenic silicon dioxide with the following ratio of components, wt%: diglycidyl ether of resorcinol 20, methyl endyc anhydride 27.7, pulverized quartz 51.2, 2-ethyl-4-methylimidazole 0.1, hydrophobic pyrogenic silicon dioxide, modified by hexamethyldisilazane, 1.0.

EFFECT: higher of heat resistance, electrical and mechanical strength of compound is the technical result of the invention; besides, electric insulating compound allows to reduce thickness of insulation with preservation of reliability of product at previous level.

1 cl, 2 tbl

Description

The invention relates to electrical insulating compounds, which can be used for pouring or impregnating parts of electrical machines, devices, conductive circuits and parts in the radio engineering, electrical and electronic industries.

Known and widely used on an industrial scale, insulating casting compounds based on epoxidic resins, for example, EPK-T compound based on EPS-1 resin (TU OYASH 504.015-76).

The EPK-T compound consists of EPS-1 epoxy resin, isomethyl tetrahydrophthalic anhydride, boron nitride, ground quartz, and an accelerator, triethanolamine.

Also known is a compound based on EPS-1 epoxy resin, isomethyl tetrahydrophthalic anhydride, boron nitride and an amine accelerator. (USSR author's certificate 686087, Н01В 3/02, publ. 15.09.1979).

However, these compounds, like all similar ones, have low heat resistance (Martens ≤100 ° С) (Papilov L.Ya. New materials for shipbuilding, L .: Shipbuilding, 1972; Handbook of electrical materials, ed. Koritsky, Yu.V. et al., Moscow, 1986, 3rd ed., Vol. 1.).

The closest in technical essence and the achieved result is an epoxy casting compound EPK-101, TU AOI 504-194-74, based on EPX-1 epoxy resin, isomethyl tetrahydrophthalic anhydride, ground quartz KP-2 and a triethanolamine accelerator, selected as a prototype. This compound has acceptable mechanical, electrical properties and heat resistance, but, nevertheless, especially in terms of heat resistance, electrical and mechanical strengths, it is less and less meeting modern requirements for electrical insulation of electrical components and parts of devices in the electronic and electrical industries.

The objective of the invention is to increase the heat resistance, electrical and mechanical strength of the casting compound.

The problem is solved in that a mixture comprising an epoxy resin, an anhydride hardener, an amine accelerator and pulverized silica is used as a casting insulating compound, characterized in that it contains resorcinol diglycidyl ether, methyldic anhydride as an anhydride hardener, as an amine accelerator, 2-ethyl-4-methylimidazole and hydrophobic pyrogenic silicon dioxide modified with hexamethyldisilazane, with the following ratios ponents, wt.%:

- diglycidyl ether of resorcinol - 20;

- methylenedic anhydride - 27.7;

- dusty quartz - 51.2;

- 2-ethyl-4-methylimidazole - 0.1;

- hydrophobic pyrogenic silicon dioxide modified with hexamethyldisilazane - 1.0.

Since polyfunctional epoxy resin based on resorcinol - UP-637, TU 6-05-241-194-79, mol. whose mass is about a third less than a mole. mass of the lowest molecular weight epoxidian resins, this provides a higher crosslinking density of the compound, which (potentially) should lead to an increase in its electrical and mechanical characteristics, as well as to an increase in heat resistance.

Since the poly-functional Diels-Alder adduct of methylcyclopentadiene and maleic anhydride is methyleneendic anhydride, the reverse reaction occurs during its hot curing, and the double bonds of the resulting methylcyclopentadiene enter into the post-curing reaction and additionally increase the density with lead (potentially) to an increase in heat resistance and mechanical and electrical strength.

The use of 2-ethyl-4-methylimidazole as an accelerator ensures, due to its high boiling point (295 ° С), a stable composition of the reaction mixture of the compound components.

The use of pyrogenic hydrophobic silicon oxide modified with hexamethyldisilazane as a functional dispersed additive provides a thixotropic effect in the reaction mixture of the compound components.

The composition for the proposed compound was prepared as follows. The components of the compound were sequentially mixed with thorough mixing. At the same time, UP-637 brand resorcinol diglycidyl ether (TU 6-05-241-194-79) was used as an epoxy resin, MEA-610 brand methyldic anhydride (TU 6-09-3886-75) was used as a hardener, particulate filler of inert disperse was used KP-2 brand dust quartz (GOST 9077-92), hydrophobic fumed silica modified with Evonik Ind brand R-8200 hexamethyldisilazane was used as a functional heterogeneous additive, and brand 2-ethyl-4-methylimidazole brand was used as an accelerator EMP CAS: 931-36-2.

Table 1 shows the chemical compositions of the claimed compound and prototype, as well as their mass parts.

Table 2 shows the properties of the claimed compound and compound of the prototype.

As you can see, the Martens heat resistance of the claimed compound is almost three times higher than the prototype compound, almost 2 times in electrical strength and mechanical strength.

Higher heat resistance, electrical and mechanical strength of the proposed compound allow to obtain more reliable electrical insulation or significantly reduce the thickness of the insulation while maintaining the reliability of the product at the same level.

Claims (1)

An insulating casting compound consisting of an epoxy resin, an anhydride hardener, an amine accelerator, pulverized quartz, characterized in that it contains resorcinol diglycidyl ether, methyldic anhydride as an hardener, and 2-ethyl-4-methylme amine accelerator as well as dispersed fillers — pulverized silica and hydrophobic pyrogenic silicon dioxide modified with hexamethyldisilazane, in the following ratio of components, wt.%:
resorcinol diglycidyl ether twenty methylenedic anhydride 27.7 dusty quartz 51,2 2-ethyl-4-methylimidazole 0.1 hydrophobic pyrogenic silica modified with hexamethyldisilazane 1,0