COMPOSITION FOR PREPARING ELECTROINSULATING COATING Russian patent published in 1998 - IPC

FIELD: electrical industry, in particular, treatment of steel to form electroinsulating coatings on its surface. SUBSTANCE: composition is applied onto anisotropic sheet electrical steel. Said composition further comprises ethyl silicate, the ratio of components being as follows, wt.%: orthophosphoric acid, 50-70; magnesium oxide, 3.0-5.3; aluminium hydroxide, 1.5-3.2; boric acid, 0.4-1.0; ethyl silicate, 0.5-2.0; and water, the balance. Use of the claimed composition makes it possible to improve physico-mechanical and magnetic properties of coatings and to use anisotropic sheet steel for twisted core transformers. EFFECT: improved properties of the composition. 1 tbl