614,957, or from the compositions based on (meth)acrylic derivatives.An abrasion-resistant coating composition which is particularly recommended in the process according to the invention is a composition comprising a .gamma.-glycidoxypropyltrimethoxysilane hydrolysate, optionally a dimethyldiethoxysilanehydrolysate, colloidal silica and aluminium acetylacetonate.Another coating which can be envisa