Patent ID: 8003710

Claim:
A method for producing hydrogel contact lenses, comprising the steps of: (1) obtaining a fluid composition, wherein the composition comprises at least one first prepolymer having multiple first propagating groups and a step-growth-propagating agent having two or more second propagating groups, wherein the first propagating groups are ene-containing groups which are mono-valent or divalent radicals each containing a carbon-carbon double bond which is not directly linked to a carbonyl group (—CO—), a benzene ring, a nitrogen atom, or an oxygen atom, wherein the second propagating groups are thiol groups each co-reactive with one of the first propagating group in a photo-induced step-growth polymerization to form a hydrogel material; (2) introducing the fluid composition into a cavity formed by a mold, wherein the mold has a first mold half with a first molding surface defining the anterior surface of a contact lens and a second mold half with a second molding surface defining the posterior surface of the contact lens, wherein said first and second mold halves are configured to receive each other such that a cavity is formed between said first and second molding surfaces; and (3) photo-inducing step-growth polymerization of the composition in the mold to crosslink said at least one first prepolymer in the presence of the step-growth propagating agent to form the hydrogel contact lens, wherein the first propagating groups are ene-containing groups of formula (II) or (III) in which R 4 -R 9 , independent of each other, are hydrogen, C 1 -C 10 alkene divalent radical, C 1 -C 10 alkyl, or —(R 18 ) a —(X 1 ) b —R 19 in which R 18 is C 1 -C 10 alkene divalent radical, X 1 is an ether linkage (—O—), a urethane linkage (—N), a urea linkage, an ester linkage, an amid linkage, or carbonyl, R 19 is hydrogen, a single bond, amino group, carboxylic group, hydroxyl group, carbonyl group, C 1 -C 12 aminoalkyl group, C 1 -C 18 alkylaminoalkyl group, C 1 -C 18 carboxyalkyl group, C 1 -C 18 hydroxyalkyl group, C 1 -C 18 alkylalkoxy group, C 1 -C 12 aminoalkoxy group, C 1 -C 18 alkylaminoalkoxy group, C 1 -C 18 carboxyalkoxy group, or C 1 -C 18 hydroxyalkoxy group, a and b independent of each other is zero or 1, optionally R 4 -R 9 are linked through an alkene divalent radical to form a cyclic ring, provided that at least one of R 4 -R 9 are divalent radicals; n and m independent of each other are integer number from 0 to 9, provided that the sum of n and m is an integer number from 2 to 9; R 10 -R 17 , independent of each other, are hydrogen, C 1 -C 10 alkene divalent radical, C 1 -C 10 alkyl, or —(R 18 ) a —(X 1 ) b —R 19 , p is an integer number from 1 to 3, provided that only one or two of R 10 -R 17 are divalent radicals.