Patent ID: 8318887

Claim:
A process for preparing a molded article, wherein the process comprises: (1) hydrolyzing, based on a total weight of (a) plus (b) plus (c), (a) from 70 to 50 wt.-% of at least one silane of formula RSiX 3 (I), wherein R is a non-hydrolyzable organic group, and the groups X, which may be the same or different, represent hydrolyzable groups, and (b) from 20 to 40 wt.-% of at least one compound selected from at least one of (b1) silanes of formula R 2 SiX 2 (II), wherein the groups R, which may be the same or different, represent non-hydrolyzable organic groups, or the groups X, which may be the same or different, represent hydrolyzable groups, and (b2) hydrolyzable polysiloxanes comprising non-hydrolyzable organic groups, (c) from 0 to 20 wt.-% of at least one silane of formula SiX 4 (III), wherein the groups X, which may be the same or different, represent hydrolyzable groups, to prepare a composite composition comprising at least one of a hydrolyzate and a condensate of the hydrolyzable components, (2) placing the composite composition in a mold, (3) curing the composite composition to increase the degree of condensation to prepare a molded article, (4) removing the molded article from the mold, and (5) heat treating the molded article at a temperature of at least 100° C.