The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 13, 1989
Filed:
Jul. 16, 1986
Isao Kaetsu, Gunma, JP;
Minoru Kumakura, Gunma, JP;
Hidenari Suyama, Kanagawa, JP;
Nobuo Kameda, Tokyo, JP;
Hideo Koyama, Saitama, JP;
Japan Atomic Energy Research Institute, Tokyo, JP;
Tokyo Contact Lens Research Institute, Tokyo, JP;
Abstract
A mixture of a specified siloxanylalkyl ester monomer and a specified vinyl monomer is polymerized by exposure to an ionizing radiation at low temperatures and the resulting polymer is worked with a lathe cut to form a contact lens. The contact lens obtained is free from any optical distortion, has good dimensional stability and exhibits high oxygen permeability. In a preferred embodiment, a monomer mixture comprising a siloxanylalkyl ester, a methacrylate or acrylate, N-vinylpyrrolidone, and a small amount of a dimethacrylate or diacrylate is exposed to a total dose of 1.times.10.sup.5 -5.times.10.sup.6 roentgens at a low temperature (-80.degree. C. to -20.degree. C. and at a dose rate of 8.times.10.sup.4 -2.times.10.sup.6 roentgens per hour, and the resulting polymer is worked into a contact lens by a suitable forming process involving cutting, grinding and polishing operations.