Finished ophthalmic lens comprising an optical smooth coating over a rough-surfaced base

Claim 1

An ophthalmic lens including substrate having a machined and unpolished rough surface and a finish thereover of optical smoothness, clarity and high scratch resistance comprising a coating selected from the group consisting of: (a) a pigment-free aqueous coating composition comprising a dispersion of colloidal silica in lower aliphatic alcohol-water solution of the partial condensate of a silanol of the formula RSi(OH) 3 in which R is selected from the group consisting of alkyl radicals of 1 to 3 inclusive carbon atoms, the vinyl radical, the 3,3,3 trifluoropropyl radical, the gamma-glycidoxypropyl radical and the gamma-methzcryloxypropyl radical, at least 70 weight percent of the silanol being CH 3 Si(OH) 3 , said composition containing 10 to 50 weight percent solids consisting essentially of 10 to 70 weight percent colloidal silica and 30 to 90 weight percent of the partial condensate; (b) a hydrolysis product of about 35 to 70 weight percent tetraethyl orthosilicate and 55 to 20 weight percent of a silane selected from the group consisting of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane and mixtures thereof and up to 20 weight percent of a siloxane having a reactive polar site; and (c) a mixture of one or more compounds selected from a group of compounds including one or both of epoxy group, and silanol and/or siloxane group (provided, in any case so selected that epoxy group, and silanol and/or siloxane group are included in the same molecule or different molecule); silica particles having a size of 1 to 100 microns; and an aluminum chelate compound of a general formula: Al.XnY.sub.3-n wherein X is OL (L: lower alkyl), Y is at least a ligand derived from compounds of general formula M 1 COCH 2 COM 2 (M 1 , M 2 both lower alkyl) and a ligand derived from compounds of general formula M 3 COCH 2 COOM 4 (M 3 , M 4 both lower alkyl) and n is 0, 1 or 2.

Claim 9

The method of finishing an opththalmic lens having a machined and unpolished rough surface comprising the steps of: coating said rough surface with a liquid pigment-free aqueous composition which is curable to external optical smoothness, clarity and high scratch resistance; and curing said coating.

Claim 10

The method of finishing an opththalmic lens having a machined and unpolished rough surface comprising the steps of: coating said rough surface with a liquid pigment-free aqueous composition which is curable to external optical smoothness, clarity and high scratch resistance; and curing said coating.