Method for preparing silicone hydrogels

US11433629B2 · kind B2 · utility

Assignee

• ALCON INC. · CH

Inventors

• Weihong Lang · Suwanee, US
• Wei Liang · Johns Creek, US
• Ying Zheng · Suwanee, US
• Karen Belinda Sentell · Alpharetta, US
• Richard Charles Breitkopf · Dunwoody, US
• Daqing Wu · Suwanee, US
• Steve Yun Zhang · Sugar Hill, US

Key dates

• Filing date: Jun 3, 2019
• Grant date: Sep 6, 2022
• Expiry date: Jun 22, 2041

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29K2105/0061
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention provides a contact lens manufacturing method for cast-molding of silicone hydrogel contact lenses having enhanced oxygen permeability without adversely affecting desirable lens mechanical properties (e.g., modulus). A method of the invention comprises adding a small amount of a radical scavenger (e.g., H-TEMPO) in a polymerizable composition for cast-molding of SiHy contact lenses) to provide the resultant polymerizable composition with a bi-phase curing profile at a curing temperature of from about 45° C. to about 100° C. With such a bi-phase curing profile, the resultant polymerizable composition can be thermally cured at the curing temperature to form a SiHy contact lens having an oxygen permeability higher than that for a polymerizable composition having the substantially identical composition excepting being free of any radical scavenger.