公开(公告)号：JPH0197626A

公开(公告)日：1989-04-17

申请号：JP16999588

申请日：1988-07-07

Applicant: ESSILOR INT

Inventor： KUROODO BUURUSU ,  JIYORUJIYU WAJI

IPC: B29C35/12 ,  B29D11/00 ,  B29K96/00 ,  B29L11/00 ,  G02C7/04

Abstract: PURPOSE: To prevent the deterioration under the molding temperature of hydrogel by sealing a specific amount of hydrogel into a cavity of a mold having a surface state of a lens to liquefy the same, then cooling the hydrogel in the mold to gelify the same, bringing the hydrogel into contact with a cross- linking agent to crosslink the same. CONSTITUTION: The hydrogel is prepared by hydrating the protein polymer. Then a lens preform is made from the hydrogel at a temperature between ambient temperature and liquefying temperature of the polymer (50-80 deg.C), and the preform is placed in the mold made of a low-loss dielectric material. The mold comprises at least two parts which define a three-dimensional shape and a finished lens surface state. Then the hydrogel is liquefied by irradiating the mold with the electromagnetic field at a frequency between 10 -10 Hz for 5-45 seconds, then gelified by cooling the mold, and crosslinked by contact with a cross-linking agent. The hydrogel is exposed to the liquefying temperature only for a very short time during the molding process of the contact lens, so that the composition and the properties thereof are hardly deteriorated during the manufacturing of one lot of contact lenses.