METHOD FOR PRODUCING POLYORGANOSILOXANE VARNISH Russian patent published in 2023 - IPC C08G77/06 C09D183/08 

FIELD: paints and varnishes.

SUBSTANCE: methods for producing polymethylphenylsiloxane varnish and modified derivatives based on it, which can be used as film formers, water repellents of various materials, binders for blend compositions and paints and varnishes. A method for producing polyorganosiloxane varnish, including esterification of methyltrichlorosilane in a mixture with 20 wt.% phenyltrichlorosilane in a water-butanol-xylene solution, removal of the resulting hydrogen chloride, hydrolysis of the esterification products, separation of the organic layer and distillation of excess solvent, characterized in that the product of hydrolysis - silanol, before distilling off the solvent, diisocyanate is introduced into the organic layer in the amount of 0.05-0.15 mol of diisocyanate per 1 mol of the starting methyltrichlorosilane, while esterification is carried out at a molar ratio of methyltrichlorosilane:butanol:water 1:2.5:0.6, hydrolysis is carried out with a solution containing 15-17 wt.% hydrogen chloride, 1-4 wt.% butanol, up to 100 wt.% water.

EFFECT: increasing the physical and mechanical properties of the lacquer film.

1 cl, 2 tbl, 10 ex