ELECTRIC INSULATING COMPOSITION Russian patent published in 2000 - IPC

FIELD: electrical engineering, specifically, compositions meant for coating of electrical sheet steel used for manufacture of magnetic circuits of electric machines and apparatuses. SUBSTANCE: composition applied to electrical sheet steel contains butadiene-styrene latex with ratio of butadiene to styrene in copolymer amounting to 35:65 per cent by mass, orthophosphoric acid, magnesium oxide, aluminum hydroxide, boric acid and surface- active substance with following proportion of components, per cent by mass: butadiene-styrene latex 23.0-26.2; orthophosphoric acid 30.5-36.1; polyoxiethylated ester or oxiethylated monoalkylphenols based of propylene trimmers 1.35-1.55; magnesium oxide 2.7-3.5; aluminum hydroxide 1.44-2.22, boric acid 0.21-0.31, water being the balance. Use of proposed composition makes it possible to improve quality of insulation coats, to increase their resistance to double fretting when coats are saturated with water which is important if articles of electrical sheet steel are used under conditions of enhanced humidity. EFFECT: increased resistance to double fretting if articles of electrical sheet steel are saturated with water with keeping of high physical and mechanical properties. 1 tbl