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US 4,273,809 AGranted
Method of preparing cast resin lenses
AssigneeAmerican Optical Corporation
InventorsNorman U. LaLiberte, Don H. Rotenberg
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Abstract
Cast resin lenses which are removed from casting molds early in a cure cycle are coated for protection against exposure to oxygen to provide increased post cure surface polymerization and abrasion resistance.
Claims9
The method of making a post-cured cast resin lens comprising the steps of:
- casting an allyl diglycol carbonate resin in a mold to the shape desired of said lens;
- partially curing said resin in said mold to produce a lens body;
- removing the partially cured lens body from said mold;
- coating the partially cured lens body with a readily removable material which is impervious to oxygen;
- exposing the coated lens body to a post-curing temperature above room temperature until substantially complete polymerization of all portions and surfaces of said lens body beneath said coating takes place;
- and
- removing the aforesaid coating for exposure and use of the post-cured lens which features high surface cure and abrasion resistance.
4 more elements
Dependencies are inferred from the claim text.