Gagnon, U.S. Pat. No. 3,650,808 describes a process for providing an abrasion resistant coating on a polycarbonate surface which comprises priming the polycarbonate surface with a compound of the formula H2 NR1 Si(OR)3 where R1 is an alkylene group, and OR is an alkoxy group of 1-4 carbon atoms, and thereafter applying to the suface a coating liquid which is produced by heating methyltrialkoxysila