Patent ID: 6221303
Filing Date: 2001-04-24
Classification: B33Y,C08F,C08G,G02B

Abstract:
An ophthalmic moulding, obtained by crosslinking a prepolymer that corresponds essentially to formula ##STR6##whereinR and R.sub.3 are each independently of the other hydrogen or methyl, one of the radicals Y.sub.1 and Y.sub.2 is hydrogen and the other is hydrogen or methyl,R.sub.1 is the radical of a linear or branched aliphatic diisocyanate having from 3 to 24 carbon atoms, the radical of a cycloaliphatic or aliphatic-cycloaliphatic diisocyanate having from 3 to 24 carbon atoms, or the radical of an aromatic or araliphatic diisocyanate having from 6 to 24 carbon atoms,R.sub.2 is a radical of formula--[CHY.sub.3 --CHY.sub.4 --O].sub.m --CHY.sub.3 --CHY.sub.4 -- (2),wherein one of the radicals Y.sub.3 and Y.sub.4 is hydrogen and the other is hydrogen or methyl,m is an integer from 4 to 99 andn is an integer from 5 to 100,in the absence or presence of an additional vinyl comonomer.