Bausch-lomb Incorporated

Martin F Van Buren

William G Deichert

Kai C Su

A process is disclosed which involves the preparation of monomeric organosilicon esters in a much shorter time and at a much higher purification than previously known in the art. More specifically, the process comprises reacting a cyclosilalkoxane having the general formula: ##STR1## wherein R is a monovalent hydrocarbon radical free of aliphatic unsaturation, R' is selected from the group consisting of H and CH.sub.3 and n is an integral of from 1 to 2 inclusive with a free radical polymerizable monocarboxylic acid. The cyclosilalkoxane is contacted with the free radical polymerizable monocarboxylic acid in the presence of a solvent. The solvent forms an azeotropic mixture with the water formed by the reaction. During the reaction, the azeotropic mixture is continuously removed from the reaction. Also present in the reaction solution is a protonating acid catalyst and a free radical polymerization preventing inhibitor. The process further comprises heating the solution to a temperature which forces the reaction to completion at an accelerated rate. During the reaction sufficient oxygen is supplied to the reaction mixture in order to convert the inhibitor present in the reaction mixture from an inactive to an active form. This process forms a substantially pure free radical polymerizable monomeric unsaturated organosilicone ester in about 3 to about 6 hours.

Preparation of monomeric organosilicon esters

Monomeric polysiloxanes end-capped with activated unsaturated groups and polymers and copolymers thereof are disclosed herein for use as contact lenses and biomedical devices with improved properties, such as, oxygen transportability, hydrolytic stability, biological inertness, transparency and improved strength without the use of fillers. The polymer composition comprises a poly(organosiloxane) monomer .alpha.,.omega. terminally bonded through divalent hydrocarbon groups to polymerized free radical polymerizably activated unsaturated groups. Contact lenses and biomedical devices i.e. shaped article for use in biomedical applications made therefrom can be 'hard' or 'soft'. This hardness or softness is a function of the comonomer or the molecular weight of the monomers. Preferably the contact lenses and biomedical devices are 'soft'. The copolymer compositions of the instant invention comprise the polymerization product of the polysiloxane monomers and monomer or monomers containing an activated vinyl group. These polymers are employed to make biomedical devices and optical products, e.g. contact lenses, intraocular implants, etc.

Polysiloxane shaped article for use in biomedical applications

Monomeric polysiloxanes end-capped with activated unsaturated groups and polymers and copolymers thereof are disclosed herein for use as contact lenses with improved properties, such as, oxygen transportability, hydrolytic stability, biological inertness, transparency and improved strength without the use of fillers. The polymer composition comprises a poly(organosiloxane) .alpha., .omega. terminally bonded through a divalent hydrocarbon group to a polymerized activated unsaturated group. Contact lenses made therefrom can be, as commonly referred to, 'hard' or 'soft'. This hardness or softness is a function of the comonomer or the molecular weight of the monomers. Preferable the contact lenses are 'soft'. The copolymer compositions of the instant invention comprise the polymerization product of the polysiloxane monomers and monomer or monomers containing an activated vinyl group. These polymers are employed to make optical products, e.g. contact lenses, intraocular implants, etc.

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Webster, NY, United States of America

Martin F Van Buren