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AssigneeMitsubishi Rayon Co., Ltd.
InventorsSeiji Tone, Hiroshi Mori, Naoki Yamamoto, Haruko Takeda, Masahiro Sugimori
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The present invention provides shaped articles having good transparency and high oxygen permeability in a specific direction thereof, which have been made from a block copolymer (a) composed of a polyalkyl methacrylate segment and a silicone-based polymethacrylate segment, or a block copolymer (b) or graft copolymer (c) containing a polyorganosiloxane as one component, according to a process permitting the creation of a specific higher-order structure. These shaped articles have high oxygen permeability at relatively low silicone contents and, therefore, can provide oxygen-permeable products having high tear strength and surface hardness.
An oxygen-permeable contact lens consisting of a block copolymer (a) of the general formula A--B, A--B--A or B--A--B where 80% by weight or more of the monomer units constituting segment A comprise an alkyl methacrylate having an alkyl group of 1 to 4 carbon atoms, 80% by weight or more of the monomer units constituting segment B comprise monomer units of the general formula
An oxygen-permeable contact lens obtained by forming fibers consisting chiefly of a block copolymer (b) or graft copolymer (c) containing an organopolysiloxane as one component, fusing or bonding a bundle of said fibers to unite them together, and cutting the resulting body in a direction perpendicular to the fiber axis.
A process for the production of transparent contact lenses having high oxygen permeability which comprises the steps of providing a block copolymer of the general formula A--B, A--B--A or B--A--B where segment A comprises an alkyl methacrylate having an alkyl group of 1 to 4 carbon atoms and segment B comprises monomer units of the general formula:
Dependencies are inferred from the claim text.