Polymer compositions for contact lenses

Claim 2

A biomedical device made from the polymerization product of a mixture comprising hydrophilic monomers and crosslinking agents, wherein the mixture also contains strengthening agents comprising a compound of the general formula: wherein: R 1 is O or NH; R 2 is a divalent alkylene radical chosen from the group consisting of --CH 2 --, --CHOH-- and --CHR 4 -- where R 4 is a branched alkyl group with 3 to 8 carbon atoms; and R 3 is H or CH 3 ; and wherein at least one R 2 radical is --CHOH-- and at least one R 2 radical is --CHR 4 -- and are separated by at least one --CH 2 -- radical, and n is 4, 5, 6, or 7.

Claim 3

In a biomedical device made from the polymerization product of a mixture of hydrophilic monomers and crosslinking agents, the improvement comprising wherein the mixture also contains strengthening agents comprising one or more compounds of the general formula: ##STR9## wherein: R 1 is O or NH; R 2 is a divalent alkylene radical chosen from the group consisting of --CH 2 --, --CHOH-- and --CHR 4 -- where R 4 is a branched alkyl group with 3 to 8 carbon atoms; and R 3 is H or CH 3 ; and wherein at least one R 2 radical is --CHOH-- and at least one R 2 radical is --CHR 4 -- and are separated by at least one --CH 2 -- radical, and n is 4, 5, 6, or 7.

Claim 4

In a biomedical device made from the polymerization product of a mixture of hydrophilic monomers and crosslinking agents, the improvement comprising wherein the mixture also contains strengthening agents comprising one or more compounds of the general formula: ##STR9## wherein: R 1 is O or NH; R 2 is a divalent alkylene radical chosen from the group consisting of --CH 2 --, --CHOH-- and --CHR 4 -- where R 4 is a branched alkyl group with 3 to 8 carbon atoms; and R 3 is H or CH 3 ; and wherein at least one R 2 radical is --CHOH-- and at least one R 2 radical is --CHR 4 -- and are separated by at least one --CH 2 -- radical, and n is 4, 5, 6, or 7.

Claim 5

A shaped biomedical device of claim 1 wherein R 1 is O.

Claim 6

A shaped biomedical device of claim 1 wherein R 1 is NH.

Claim 7

A shaped biomedical device of claim 1 wherein R 2 is a branched C 4 to C 6 alkyl group.

Claim 8

A shaped biomedical device of claim 5 wherein R 2 is an isobutyl group.

Claim 9

A shaped biomedical device of claim 1 wherein n is 5.

Claim 10

A shaped biomedical device of claim 1 wherein n is 6.

Claim 11

A shaped biomedical device of claim 1 wherein R 3 is H.

Claim 12

A shaped biomedical device of claim 1 wherein R 3 is CH 3 .

Claim 13

A shaped biomedical device of claim 1 wherein said strengthening agent comprises 4-t-butyl, 2-hydroxycyclohexyl methacrylate.

Claim 14

A shaped biomedical device of claim 1 wherein said strengthening agent comprises 4-t-butyl, 2-hydroxy-cyclohexyl methacrylamide.

Claim 15

A shaped biomedical device of claim 1 wherein said hydrophilic monomer is selected from one or more of the group comprising hydroxyethyl methacrylate, n-methacryloyl amino hydroxyethane, N-vinylpyrrolidone, glyceryl methacrylate and n-methacryloyl glycene.

Claim 16

A shaped biomedical device of claim 1 wherein said hydrophilic monomer includes N-vinylpyrrolidone.

Claim 17

A shaped biomedical device of claim 14 wherein said strengthening agent is 4-t-butyl, 2-hydroxycyclohexyl methacrylate.

Claim 18

A shaped biomedical device of claim 14 wherein said strengthening agent is 4-t-butylhydroxycyclohexyl methacrylamide.

Claim 19

A soft contact lens made from the biomedical device of claim 3 in the hydrated state.

Claim 20

A soft contact lens made from the biomedical device of claim 4 in the hydrated state.

Claim 21

A soft contact lens made from the biomedical device of claim 11 in the hydrated state.

Claim 22

A soft contact lens made from the biomedical device of claim 12 in the hydrated state.

Claim 23

A soft contact lens made from the biomedical device of claim 13 in the hydrated state.

Claim 24

A soft contact lens made from the biomedical device of claim 14 in the hydrated state.

Claim 25

A polymeric hydrogel soft contact lens prepared from the biomedical device of claim 1 containing at least 80 weight percent water of hydration.

Claim 26

A polymeric hydrogel soft contact lens prepared from the biomedical device of claim 1 containing at least 60 weight percent water of hydration.

Claim 27

The biomedical device of claim 1 wherein the device is a polymeric soft contact lens hydrogel having at least 80 weight percent water of hydration, a modulus of elasticity of at least 50 g/mm 2 and an initial tear resistance of at 2.0 g/mm.

Claim 28

A biomedical device of claim 1 wherein said mixture comprise: 35 to 90 parts by weight of hydrophilic monomers; 0.1 to 5 parts by weight of crosslinking agents; and 6 to 65 parts by weight of strengthening agents.

Claim 29

A soft contact lens made from the biomedical device of claim 13 wherein the hydrophilic monomer is a mixture of hydroxyethyl methacrylate and N-vinylpyrrolidone and the strengthening agent is 4-t-butyl, 2-hydroxycyclohexyl methacrylate.

Claim 30

A soft contact lens made from the biomedical device of claim 2.

Claim 31

The polymeric soft contact lens hydrogel of claim 25 wherein said weight percent water is at least 82, said modulus of elasticity is at least 75 g/mm 2 , and said initial tear resistance is at least 7.0 g/mm.