Abstract:
The invention provides a TRIS-containing vinylic monomer which comprises one sole (meth)acryloyloxy group and a tris(trimethylsiloxy)silyl group covalently linked to the ethylenically-unsaturated group through a polyoxyethylene linker. The present invention is also related to a polymer, an actinically-crosslinkable silicone-containing prepolymer, a silicone hydrogel polymeric material, or a silicone hydrogel contact lens, which comprises monomeric units derived from a TRIS-containing vinylic monomer of the invention. In addition, the invention provides a method for making a TRIS-containing vinylic monomer of the invention.
Abstract:
The invention provide a class of water-processable polymerizable prepolymers which comprises (1) siloxane-containing monomeric units derived at least one siloxane containing monomer having one hydrophilic group or chain and/or polysiloxane-containing crosslinking units derived from at least one hydrophilized polysiloxane or chain-extended polysiloxane crosslinker; (2) hydrophilic monomeric units derived from one or more hydrophilic vinylic monomers; and (3) from about 0.05% to about 5% by weight of polymerizable units each having a pendant or terminal, ethylenically-unsaturated group and free of any polysiloxane segment. The prepolymer comprises from about 20% to about 50% by weight of silicone relative to the total weight of the prepolymer and has a high water solubility or dispersibility of at least about 5% by weight in water and suitable for making silicone hydrogel contact lenses.
Abstract:
The invention provide a class of chain-extended polysiloxane crosslinkers which comprises (1) at least two polylsiloxane segments, wherein each pair of adjacent polysiloxane segments is linked by one divalent organic radical which includes at least one pendant hydrophilic group (hydroxyl and/or carboxyl groups) or at least one dangling hydrophilic polymer chain and a di-thioether linkage —S-DR-S— in which DR is a divalent organic radical; and (2) two terminal ethylenically unsaturated groups. The present invention is also related to a polymer comprising crosslinking units derived from chain-extended polysiloxane crosslinker of the invention and to ophthalmic lenses comprising such a polymer.
Abstract:
The present invention provides an amphiphilic polysiloxane prepolymer which comprises hydrophilic monomeric units derived from at least one hydrophilic vinylic monomer, polysiloxane crosslinking units derived from at least one polysiloxane crosslinker having at least two terminal ethylenically-unsaturated groups, dangling polysiloxane chains each of which is terminated with one ethylenically unsaturated group, and chain-transfer units derived from a chain transfer agent other than a RAFT agent. A prepolymer of the invention is suitable for making hydrogel contact lenses. The present invention is also related to hydrogel contact lenses made from an amphiphilic polysiloxane prepolymer of the invention and to processes for preparing an amphiphilic polysiloxane prepolymer of the invention and for making silicone hydrogel contact lenses.
Abstract:
The invention is related to a method for qualifying and quantifying carboxyl groups on the surfaces of a silicone hydrogel contact lens. The method of the invention comprises the steps of: (a) obtaining silicone hydrogel contact lenses each of which comprises a silicone hydrogel lens body (i.e., bulk material) and a coating thereon, wherein the silicone hydrogel lens body is obtained from a lens formulation free of any polymerizable component including one or more carboxyl groups, wherein the coating comprises a polymer having carboxyl groups; (b) immersing a given number of the silicone hydrogel contact lenses in a fixed volume of a C1-C4 alcohol solution of a positively-charged dye having acetate as counter anion at a given initial concentration for a time period sufficient to stain the silicone hydrogel contact lens; and (c) determining the concentration of carboxyl groups per each silicone hydrogel contact lens and/or the thickness of the coating on the silicone hydrogel contact lens.
Abstract:
The invention provide a class of linear chain-extended polysiloxane crosslinkers which comprises two terminal ethylenically unsaturated groups, at least two polysiloxane segments, and dangling hydrophilic polymer chains each covalently attached to a divalent organic radical separating each pair of adjacent polysiloxane segments. The present invention is also related to a polymer comprising crosslinking units derived from chain-extended polysiloxane crosslinker of the invention and to ophthalmic lenses comprising such a polymer.
Abstract:
The invention relates to novel crosslinkable copolymers which are obtainable by (a) copolymerizing at least two different hydrophilic monomers selected from the group consisting of N,N-dimethyl acrylamide (DMA), 2-hydroxyethyl acrylate (HEA), glycidyl methacrylate (GMA), N-vinylpyrrolidone (NVP), acrylic acid (AA) and a C1-C4-alkoxy polyethylene glycol(meth)acrylate having a weight average molecular weight of from 200 to 1500, and at least one crosslinker comprising two or more ethylenically unsaturated double bonds in the presence of a chain transfer agent having a functional group; and (b) reacting one or more functional groups of the resulting copolymer with an organic compound having an ethylenically unsaturated group.
Abstract:
The invention provide a class of actinically-crosslinkable silicone-containing prepolymers obtained by functionalizing an intermediary copolymer to have two or more thiol or ethylenically-unsaturated groups covalently attached thereto, wherein the intermediary copolymer is an atom-transfer radical polymerization (ATRP) product of a reactive mixture comprising a polysiloxane ATRP macroinitiator and at least one hydrophilic vinylic monomer. The present invention is also related to silicone hydrogel contact lenses made from a prepolymer of the invention and methods for making the contact lenses in a cost-effective way and with high consistency and high fidelity to the original lens design.
Abstract:
Described herein is a cast-molding process for producing contact lenses in a relatively-short curing time from a lens-forming composition, which comprises (a) at least one thiol-containing compound or component, (b) at least one metal scavenger, and (c) at least one free radical scavenger and which has a pH of from about 2.5 to about 5. The addition of a chain-transfer agent into a lens-forming composition can reduce not only the curing time of the lens-forming composition but also reduce the elastic modulus of resultant crosslinked materials (e.g., contact lenses) from the lens-forming composition. The lower pH and the addition of metal scavenger and the free radical scavenger into the lens-forming composition can ensure that the lens-forming composition to have a shelf life of at least three days.
Abstract:
The invention is related to a class of hydrophilic poly(meth)acrylamide-based copolymer comprising dangling (i.e., pendant) phosphorylcholine groups and dangling (i.e., pendant) reactive groups or chains each of which comprises one carboxyl group, one thiol group, or one primary or secondary amino group. The hydrophilic copolymers have a relatively high affinity to a base coating of a polyanionic polymer on a medical device or contact lens and are reactive towards azetidinium groups of an azetidinium-containing polymer upon heating. They can find particular use in producing water-soluble highly-branched hydrophilic polymeric material and in producing water gradient contact lenses.