Evaluation method for the coverage of a coating on a contact lens surface
US11448796B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 11, 2019 |
| Grant date | Sep 20, 2022 |
| Priority date | — |
| Expiry date | Jun 24, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2329/04
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The invention provides a method for determining whether a coated contact lens is completely covered by a covalently bonded coating, comprising the steps of (1) providing a coated polyvinylalcohol-based hydrogel contact lens wherein the polyvinylalcohol-based hydrogel lens body is composed of a polymer comprising at least 50% by mole of repeating units of vinyl alcohol, comprising a lubricious coating covalently attached to the lens body, (2) contacting the coated polyvinylalcohol-based hydrogel contact lens with an aqueous solution of a hydrophilic marker polymer for obtaining a treated contact lens, the hydrophilic marker polymer having reactive groups of in which R1 is methyl or ethyl and R2 is hydrogen or a C1-C4 alkyl and a dye tag moiety, at a pH of 4.0 or less for a contacting time to covalently attach the marker polymer onto the coated polyvinylalcohol-based hydrogel contact lens through 6-membered acetal rings, (3) determining whether marker polymer is (covalently) attached to the surface of the treated contact lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.