Kingston Technologies, L.p.

Kingston Technologies Limited Partnership

Jan Lovy

Vladimir A Stoy

George P Stoy

Novel amphoteric acrylic and methacrylic copolymers are described comprising cationic units of pendant N-substituted amidine and anionic units of acrylic or methacrylic acid and/or acidic groups carried by substituents of N-acrylamide, N-methacrylamide, N-acrylamidine or N-methacrylamidine. One preferred embodiment is a copolymer in which at least some types of functional groups are organized in blocks. Particularly preferred are blocks of pendant nitrile groups. Preferred compositions have the said N-substituents of the amides and/or amidines containing polar groups other than primary amines. Particularly preferred polar groups are tertiary amines, quaternary ammonium salts, hydroxyls and sulfonic acid. These copolymers may optionally be convalently or physically crosslinked and swellable rather than soluble in water. A method of preparing said amphoteric acrylic and methacrylic copolymers is described comprising the reaction of selected polymers with a multitude of pendant CN groups in mutual 1,3 positions with a primary amine in presence of water. One preferred method is the reaction of CN groups with the primary amine and water in the presence of a solvent of the said polymer and/or in the presence of a basic catalyst. The particularly preferred embodiment is a reaction of CN groups containing polymer dissolved in a mixture of the polymer solvent, a primary amine, water and an optional basic catalyst.

Hydrophilic acrylic copolymers and method of preparation

Stable emulsions and dispersions of both the water-in-oil and oil-in-water types are prepared by subjecting mixtures of the two phases to shear stress in the presence of nitrile group-containing copolymers capable of forming hydrogels containing at least 90% by weight of water at room temperature.

Pan emulsion

The present invention contact lens is a soft, disposable lens which, under eye wearer conditions, changes one or more characteristics essential for comfortable use, at a predetermined time to initiate disposal thereof by the user. This lens, under wear conditions, changes, for example, at least its base curve redius and its deformability as a consequence of a change in hydrophilicity of at least a portion of the contact lens material. This hydrophilicity change may be achieved by various means, e.g. degradation of crosslinking bridges or conversion of less hydrophilic groups to groups having greater hydrophilicity. In one preferred embodiment, the conversion is achieved by hydrolysis of selected functional (hydrophobic) groups into hydrophilic groups.

Contact lens with pre-determined useful life

A method is disclosed for preparing polyacrylonitrile copolymers by Heterogeneous reaction of polyacrylonitrile aquagel. Generally, the method includes the steps of preparing a solution of polyacrylonitrile by dissolving the polyacrylonitrile in a water-miscible solvent which is capable of dissolving the polyacrylonitrile but incapable of hydrolyzing the nitrile groups of the polyacrylonitrile under the dissolution conditions. Coagulating the polyacrylonitrile solution by replacing the solvent with a coagulating fluid such as water or a water-miscible fluid incapable of dissolving polyacrylonitrile at temperatures below 80.degree. C. and incapable of reacting with the nitrile groups of the polyacrylonitrile, thus obtaining the polymer in the aquagel state. Replacing the coagulating fluid with a fluid reagent capable of reacting with the nitrile groups of the polyacrylonitrile aquagel but incapable of dissolving the polyacrylonitrile aquagel at the selected reaction temperature. Allowing the fluid reagent to chemically react with the nitrile groups of the aquagel while the polyacrylonitrile aquagel is undissolved to form a copolymer product. The copolymer product is then either used in further chemical reactions involving newly formed and/or original side substituents, or isolated and utilized for molding or shaping into various articles. Various plasticizers, which when undiluted are capable of dissolving polyacrylonitrile, may be added to the copolymer product to assist in molding or shaping the material into an article.

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Princeton, NJ, United States of America

Jan Lovy