Title:
PVA CONTACT LENS
Document Type and Number:
Japanese Patent JP3163473
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain a contact lens having a high water content, flexibility and excellent long-term stability by grinding and polishing a copolymer comprising vinyl acetate and triallyl isocyanurate to form a lens and hydrolyzing the lens.
SOLUTION: A crosslinked polyvinyl alcohol contact lens having a water content of 20-80 is produced by grinding and polishing a copolymer comprising 90-99.9wt.% vinyl acetate and 0.1-10wt.% triallyl isocyanurate under cooling and hydrolyzing the lens. In this production, the above copolymer is shaped under cooling because it is soft and it is usually difficult to shape the copolymer into a lens by grinding and polishing at room temperature. For instance, it is cooled to -20°C and shaped into a lens under sprinkling with chilled water. Although the hydrolysis method is not particularly limited, the hydrolysis is performed by immersing the copolymer in an aqueous alkali solution. An article having flexibility and excellent long-term stability can be obtained.
Inventors:
Satoshi Honda
Isao Kaetsu
Isao Kaetsu
Application Number:
JP20851195A
Publication Date:
May 08, 2001
Filing Date:
July 25, 1995
Export Citation:
Assignee:
Seed corporation
International Classes:
G02C7/04; C08F8/12; C08F16/02; C08F26/02; C08F216/06; C08F218/02; C08F218/08; C08F226/00; (IPC1-7): C08F216/06; C08F8/12; C08F218/08; C08F226/00; G02C7/04
Domestic Patent References:
| JP6102471A | ||||
| JP713109A | ||||
| JP7181435A |
Attorney, Agent or Firm:
Taketane Kikuchi