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US 5,352,245 AGranted
Process for tinting contact lens
AssigneeCiba-Geigy Corporation
InventorsKai C. Su, William M. Hung
Life of this patent
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Abstract
A contact lens colorant formulation containing a surfactant is applied to a dry hydrophilic contact lens by means of a silicon rubber printing pad to provide a cosmetically acceptable, solid, unblemished covering. This process allows for a solid covering to be placed onto the lens in a single printing step using standard transfer printing devices.
Claims18
A method of providing a solid, substantially unblemished cover of colorant on the surface of a dry hydrophilic contact lens comprising the steps of:
- (a) placing a colorant solution comprising a coloring agent, a surfactant selected from the group consisting of polyalkylene oxide-modified methylpolysiloxanes;
- 2,4,7,9-tetramethyl-5-decyn-4,7-diol;
- ethylene oxide adducts of 2,4,7,9-tetramethyl-5-decyn-4,7-diol and mixtures thereof, and water onto a silicon rubber printing pad;
- (b) contacting the printing pad with a surface of the contact lens to transfer the colorant solution to the lens;
- and
- (c) affixing the colorant to the lens;
- wherein said surfactant is present in an amount sufficient to produce a substantially solid, unblemished cover of colorant on said contact lens.
4 more elements
Dependencies are inferred from the claim text.