Method for preparing high-purity electro-melting corundum aluminum oxide epoxy casting filler

Abstract

The invention belongs to insulating encapsulation materials of the electric and electronic field, and relates to a method for preparing high-purity electro-melting corundum aluminum oxide epoxy casting filler. The method adopts a method introducing boric acid as the additive in the process of electric smelting of industrial aluminum oxide raw materials, and generates volatiles through the reaction of boric acid with NaO2 in the process of smelting, so that the content of NaO2 in electro-melting corundum is substantially reduced, the added amount of the boric acid is 0.5-5%wt of the weight of the industrial aluminum oxide raw materials, and the content of the detrimental impurity NaO2 in the electro-melting corundum aluminum oxide can be lowered along with the increase of addition amount of the boric acid; and when the addition amount of the boric acid is 1.5%wt, the NaO2 content in the electro-melting corundum aluminum oxide can be lowered to 0.05% below, and the high-purity and low-cost electro-melting corundum aluminum oxide filler is industrially obtained. The prepared electro-melting corundum aluminum oxide filler has large addition amount, long casting time and stable performance due to the low starting viscosity of epoxy casting.

Description

Technical field: [0001] The invention belongs to the field of electrical and electronic insulation packaging materials, and relates to a preparation method of high-purity fused corundum alumina epoxy pouring filler. Background technique: [0002] Epoxy resin has excellent electrical insulation performance, high mechanical strength, heat resistance, chemical corrosion resistance and good process performance. It has become a high-quality and economical electrical insulation material in the electronics and electrical industries, and is widely used in the insulation of electronics and electrical components. Packaging and preparation of insulating parts in high-voltage electrical appliances such as high-voltage switches, dry-type transformers, and high-voltage current transformers. In recent years, with the SF 6 Electrical products, especially fully enclosed SF 6 With the development of combined electrical appliances (GIS), the requirements for epoxy castings are more stringent...

AI Technical Summary

Problems solved by technology

Medium Al in fused white corundum 2 o 3 The content is more than 99%, but the main Na in the abrasive industry fused corundum 2 The O impurity amount is too high, reaching more than 0.5%, which is much higher than that of epoxy cast alumina filler Na 2 O content standard, resulting in a small amount of alumina filler, high initial viscosity of epoxy castables, short service life, difficult to be used in insulating castables

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