Patent ID: 7268189

Claim:
A process for the manufacture of a moulding, comprising the steps of: A) providing a mold for making the moulding; B) introduce a solution into the mold, wherein the solution comprises (i) one or more crosslinkable prepolymers which are obtained by ultrafiltration, (ii) one or more solvents selected from the group consisting of a C 1 -C 6 -alkanol, a glycol, a carboxylic acid amide, dimethyl sulfoxide and water, wherein each of said one or more crosslinkable prepolymer is obtained by (a) copolymerizing at least one hydrophilic monomer having one first ethylenically unsaturated group and at least one crosslinker comprising two or more second ethylenically unsaturated groups in the presence of a chain transfer agent comprising a chain transfer group and a first reactive group to obtain a copolymerization product with first reactive groups, wherein said at least one crosslinker is a polysiloxane, a perfluoroalkyl polyether, or a polysiloxane/perfluoroalkyl polyether block copolymer, wherein the hydrophilic monomer is a monomer which, when polymerized, gives a homopolymer which is water-soluble or can absorb at least 10% by weight of water, and (b) reacting an organic compound with the copolymerization product to form the crosslinkable or polymerizable prepolymer having third ethylenically unsaturated groups, wherein the organic compound comprises a third ethylenically unsaturated group and a second reactive group, wherein the second reactive group of the organic compound reacts with one of the first reactive groups of the copolymerization product, wherein each of said one or more crosslinkable prepolymer is substantially free of monomeric, oligomeric or polymeric starting compounds used for the preparation of the prepolymer, and/or free of secondary products formed during the preparation of the prepolymer, wherein said solution is substantially free of comonomers; and C) crosslinking said one or more crosslinkable prepolymers to form the moulding.