SILICON OR SILICA SUBSTRATE WITH A MODIFIED SURFACE, PROCESS FOR PRODUCING THE SAME, NEW ORTHOESTERS AND PROCESS FOR PRODUCING THE SAME

摘要

The silicon or silicon dioxide substrate of the present invention have a novel modified surface which is occupied by the alcohol moiety of an orthoester. Said alcohol moiety can be saturated or unsaturated. The modification is effected by treating the surface of the substrate with an orthoester. Thereby, the water is eliminated by hydrolysis form the surface, and the formed alcohol or silylether therafter takes the place of the water. Particularly suitable are new orthoesters of the general formula R1C¢OCH2-CH2-O-CO-CH2CH2!3, wherein R1 is hydrogen or a cleavable organic residue, and R is (CH2)n, n being an integer form 1 to 18, and new orthoesters of the general formula (see formula I) wherein R1 is hydrogen or an organic residue, R3 is hydrogen or an alkyl group of 1 to 6 carbon atoms; and R4 is hydrogen, an alkyl group or a phenyl group. The modified surfaces have an increased boundary or contact angle and thus a reduced wett-ability. Moreover, they can react via reactive substituents with other monomers or polymers. This kind of surface modification advantageously replaces the silanization used so far for glass and other silicates.