Patent ID: 6054522
Filing Date: 2000-04-25
Classification: C03C,C09D

Abstract:
A protective coating for an inorganic article provides improved resistance to abrasion, resists adhesion to foods and is hydrophobic, the coating being the condensation product between hydroxyl groups on the surface of the inorganic article and a composition comprising the following components:(a) a silane having the formula R.sub.n SiX.sub.4-n, whereineach R is chosen independently from the group consisting of methyl radical, ethyl radical, or propyl radical, unsubstituted or partially or totally substituted by fluorine atoms;X is a hydrolyzable group chosen from the group consisting of methoxy, ethoxy and chloro groups; and,n=1 or 2;(b) a metal alkoxide having at least three hydrolyzable branches and a formula R MX.sub.3 or MX.sub.4, whereinR is selected from the group consisting of methyl group, ethyl group, propyl group, and butyl group,M is a metal selected from the group consisting of silicon, titanium, zirconium and aluminum, and,X is a hydrolyzable group selected from the group consisting of methoxy, ethoxy and chloro groups; and,(c) a mixture of lower alkanol and acidified water, the water being acidified at least in cases where X is a methoxy or ethoxy group; wherein(i) the silane content is at least 50 mole % of the total sum of the silane plus the metal alkoxide;(ii) the metal alkoxide is at least 10 mole % of the total sum of the silane plus the metal alkoxide.