Dimethylacrylamide-copolymer hydrogels with high oxygen permeability
First Claim
1. A copolymer, having the characteristics of high clarity, high hydrophilicity, and high oxygen permeability and which is, in the water swollen hydrated state, soft and flexible, which copolymer comprises the polymerization product of, with weight percent based on the total weight of monomers (a), (b), (c) and (d), of(a) 24.9 to 70 percent by weight of N,N-dimethylacrylamide,(b) 65 to 19.9 percent by weight of a vinyl monomer selected from the group consisting of the acrylate or methacrylate esters of formula B1 ##STR5## wherein R1 is hydrogen or methyl,n is an integer from 1-4,m is an integer from 0-11,X is hydrogen or fluorine, with the proviso that, when m is 0, X is fluorine;
- and hexafluoroisopropyl methacrylate,(c) 10 to 40 percent by weight of a C2 -C4 -hydroxyalkyl acrylate or methacrylate, a C2 -C4 -alkoxy-alkyl acrylate or methacrylate or an oligosiloxanyl-silylalkyl acrylate or methacrylate containing 2 to 10 silicon atoms, or mixture thereof, and(d) 0.1 to 3 percent by weight of a crosslinking agent having at least two copolymerizable vinyl groups.
1 Assignment
0 Petitions
Accused Products
Abstract
This invention describes polymers which are obtained by copolymerization of 15-85 wt % N,N-dimethylacrylamide with about 15-85% of a fluorinated monomer such as perfluoroalkyl-alkylene acrylate or methacrylate with from 3 to 25 fluorine atoms and optionally, 0-50 wt % other acrylates or methacrylates and 0-20 wt %, but not more than 5 mol % of a polyvinyl functional crosslinking agent. These polymers are machinable in the dry state and form clear hydrogels with about 25-75 wt % water content and which possess oxygen-permeabilities 3-7 times higher than conventional hydrogels of similar water content. In the absence of crosslinking, the novel polymers are plasticized by water, forming clear hydroplastics with 30-70 wt % water content. The crosslinked polymers are especially useful for fabricating contact lenses for extended wear by either cutting and polishing a xerogel button, or by spin casting or direct molding in bulk or in solution.
374 Citations
12 Claims
-
1. A copolymer, having the characteristics of high clarity, high hydrophilicity, and high oxygen permeability and which is, in the water swollen hydrated state, soft and flexible, which copolymer comprises the polymerization product of, with weight percent based on the total weight of monomers (a), (b), (c) and (d), of
(a) 24.9 to 70 percent by weight of N,N-dimethylacrylamide, (b) 65 to 19.9 percent by weight of a vinyl monomer selected from the group consisting of the acrylate or methacrylate esters of formula B1 ##STR5## wherein R1 is hydrogen or methyl, n is an integer from 1-4, m is an integer from 0-11, X is hydrogen or fluorine, with the proviso that, when m is 0, X is fluorine; - and hexafluoroisopropyl methacrylate,
(c) 10 to 40 percent by weight of a C2 -C4 -hydroxyalkyl acrylate or methacrylate, a C2 -C4 -alkoxy-alkyl acrylate or methacrylate or an oligosiloxanyl-silylalkyl acrylate or methacrylate containing 2 to 10 silicon atoms, or mixture thereof, and (d) 0.1 to 3 percent by weight of a crosslinking agent having at least two copolymerizable vinyl groups. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- and hexafluoroisopropyl methacrylate,
Specification