Polysiloxane hydrogels

A water-insoluble hydrophilic gel comprising the crosslinked copolymerization product of

• (A) about 20 to about 90% by weight of said gel of (a) a water-soluble monoolefinic monomer, or mixture of said monomers, or (b) a water-soluble monomer, or mixture of said monomers, with 1 to 80% by weight of total monomers of a water-insoluble monoolefinic monomer, or mixture of said water-insoluble monomers, with
• (B) about 10 to about 80% by weight of said gel of a terminal polyolefinic hydrophobic siloxane macromer having a molecular weight from about 400 to about 8500, said macromer having the formula ##STR13## wherein R.sub.1 is a polysiloxane chain having a molecular weight from about 200 to about 8000, and is of the formula ##STR14## R.sub.2 is hydrogen or methyl, R.sub.3 is hydrogen or --COOR.sub.4,
• R.sub.4 is hydrogen or alkyl of 1 to 10 carbon atoms, and with the proviso that at least one of R.sub.2 and R.sub.3 is hydrogen,
• X is oxa, --COO-- or --CONR.sub.5 --,
• R.sub.5 is hydrogen or alkyl of 1 to 5 carbon atoms,
• R.sub.6 is a branched or linear alkylene of 1 to 7 carbon atoms or --CH.sub.2 CH.sub.2 O--.sub.n where n is 1 to 20,
• x is an integer of 3 to 120,
• y is an integer of 2 to 3,
• z is an integer of 1 to 2,
• Y is the direct bond, the diradical
• --R.sub.7 Z.sub.1 --CONH--R.sub.8 --NHCO--Z.sub.2 --, or --R.sub.7 OCOCH.sub.2 CH.sub.2 S--,
• R.sub.7 is a linear or branched alkylene of 2 to 5 carbon atoms connected to X,
• R.sub.8 is a diradical obtained by removing the NCO groups from an aliphatic, cycloaliphatic or aromatic diisocyanate,
• Z.sub.1 is oxa or --NR.sub.5 --,
• Z.sub.2 is Z.sub.1 or thia and is connected to R.sub.6, with the proviso that if X is oxa, Y is different from a direct bond and R.sub.2 and R.sub.3 are hydrogen.