Contact lens material
AssigneeBiocompatibles Limited
InventorsRoderick William Jonathon Bowers, Peter William Stratford, Stephen Alister Jones
Life of this patent
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Abstract
Cross-linked copolymers which are obtained by polymerising a neutral diluent monomer or monomers, a monomer or monomers bearing a center of permanent positive charge, and a bifunctional and/or trifunctional cross-linking agent, are suitable for use in contact lenses. Process for producing them by copolymerisation, contact lens material comprising them, contact lenses made of them and processes for producing contact lenses from them.
Claims16
A crosslinked copolymer which is obtainable by polymerising a neutral diluent monomer or monomers, a zwitterionic monomer or monomers and a bifunctional or trifunctional crosslinking agent.
A copolymer according to any one of the preceding claims in which the zwitterionic comonomer or comonomers bears a centre of positive charge provided by a quaternary nitrogen atom.
A copolymer according to any one of the preceding claims which is obtainable by copolymerising a zwitterionic monomer of formula (I)
- Y—B—X (I)
- wherein B is a straight or branched alkylene, oxaalkylene or oligo-oxaalkylene chain or if X contains a carbon-carbon chain between B and the zwitterionic group or if Y contains a terminal carbon atom, a valence bond,
- X is a zwitterionic group and
- Y is an ethylenically unsaturated polymerisable group selected from
- 17
- wherein:
- R is hydrogen or a C1-C4 alkyl group;
- A is —O— or —NR1— where R1 is hydrogen or a C1-C4 alkyl group or R1 is —B—X where B and X are as defined above;
- and
- K is a group —(CH2)pOC(O)—, —(CH2)pC (O)O—, —(CH2)pOC(O)O—, —(CH2)pNR2—, —(CH2)pNR2C(O)—, —(CH2)pC(O)NR2—, (CH2)pNR2C(O)O—, —(CH2)pOC(O)NR2—, —(CH2)pNR2C(O)NR2— (in which the groups R2 are the same or different), —(CH2)pO—, —(CH2)pSO3—, or, optionally in a combination with B, a valence bond, and p is from 1 to 12 and R2 is hydrogen or a C1-C4 alkyl group.
Dependencies are inferred from the claim text.