Patent ID: 7368589

Claim:
A process for purifying at least one silicone containing monomer comprising the steps of contacting said at least one silicone containing monomer of Formula I or II wherein: n is an integer between 3 and 35, R 1 is hydrogen, C 1-6 alkyl; R 2 , R 3 , and R 4 , are independently, C 1-6 alkyl, triC 1-6 alkylsiloxy, phenyl, naphthyl, substituted C 1-6 alkyl, substituted phenyl, or substituted naphthyl where the alkyl substitutents are selected from one or more members of the group consisting of C 1-6 alkoxycarbonyl, C 1-6 alkyl, C 1-6 alkoxy, amide, halogen, hydroxyl, carboxyl, C 1-6 alkylcarbonyl and formyl, and where the aromatic substitutents are selected from one or more members of the group consisting of C 1-6 alkoxycarbonyl, C 1-6 alkyl, C 1-6 alkoxy, amide, halogen, hydroxyl, carboxyl, C 1-6 alkylcarbonyl and formyl; R 5 is hydroxyl, an alkyl group containing one or more hydroxyl groups; or (CH 2 (CR 9 R 10 ) y O) x )-R 11 wherein y is 1 to 5, x is an integer of 1 to 100; R 9 -R 11 are independently selected from H, alkyl having up to 10 carbon atoms and alkyls having up to 10 carbon atoms substituted with at least one polar functional group, R 6 is a divalent group comprising up to 20 carbon atoms; R 7 is a monovalent group that can undergo free radical and/or ionic polymerization and comprising up to 20 carbon atoms; R 8 is a divalent group comprising up to 20 carbon atoms with a supercritical fluid having a density of between about 0.2 and about 1 g/ml, decreasing said density so that two phases are formed a first phase comprising said at least one silicone containing monomer and a second phase comprising at least one impurity and separating said second phase from said first phase.