METHOD AND COMPOUND FOR RECEIVING OF ELECTRICAL INSULATING COATING Russian patent published in 2009 - IPC C23C22/33 

FIELD: metallurgy.

SUBSTANCE: invention relates to field of steel treatment for receiving of electric insulating coatings on its surface and can be used in electrical industry. Compound for receiving of coating contains components at following correlation, wt %: phosphate ions (in terms of P₂O₅) 6.6 - 14.6, aluminium ions (Al³⁺) 0.3 - 0.71, magnesium ions (Mg²⁺) 0.41 - 0.92, chrome ions (Cr⁶⁺) 1.45 - 3.2, colloidal silicon dioxide with micelles diametre 8.4 ± 0.5 nm (in terms of SiO₂) 9.0 - 20.0, water - the rest, herewith correlation P₂O₅/(Mg ⁺ + Al³⁺) = 8.5 - 11.5, SiO₂/P₂O₅ = 1.0 - 1.5. Preparation method of compound includes separate preparation of water solutions of aluminium and magnesium phosphates by means of repulping of powders of aluminium hydroxide and caustic magnesite in water at room temperature and correlation H : L = 0.24 in reactor with mixer revolutions 200 rpm during 1 hour, then into repulped powders it is fed phosphoric acid at a rate 59 litres per minute at temperature up to 100 °C up to full solution, solutions are isolated at temperature 95 - 100 °C during 3 hours, cooled up to 40 °C and is mixed, then it is introduced chromic anhydride and at blending at a rate 200 rpm it is introduced colloidal silicon dioxide at its feeding 0.03 m³ per minute for 0.02 m³ of phosphate part.

EFFECT: invention provides increasing of compound stability and receiving of electrical insulating coating with good finished appearance, allowing increased physical-mechanical and magnetic properties, high magnetic activity, and removing of sticking problem.

2 cl, 1 tbl, 7 ex