Hydrophilic coatings and process for preparing the same

摘要

Hydrophilic coatings are obtained by applying to a substrate a composition containing an aqueous soluble organopolysiloxane which is capable of being crosslinked by the addition of Si-bonded hydrogen atoms to SiC-bonded aliphatic multiple bonds, and having at least one oxyalkylene unit bonded to a silicon atom and an aqueous soluble catalyst which promotes the addition of Si-bonded hydrogen atoms to the SiC-bonded aliphatic multiple bonds and thereafter crosslinking the organopolysiloxane by the addition of the Si-bonded hydrogen atoms to the SiC-bonded aliphatic multiple bonds to form a hydrophilic coating on the substrate. The aqueous soluble organopolysiloxane may be obtained from a mixture consisting of equal parts of a mixed hydrolysate, prepared from 1.7 moles of dimethyldichlorosilane, 1 mole of [acetoxy-(hexaethyleneoxy)propyl]-methyldichlorosilane and 0.3 mole of vinylmethyldichlorosilane, and a mixed hydrolysate prepared from 1 mole of dimethyldichlorosilane, 1 mole of [acetoxy(hexaethyleneoxy)-propyl]-methyl-dichlorosilane and 1 mole of methyldichlorosilane.