The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 27, 2009
Filed:
Jul. 06, 2001
Nathaly Vassal, Paris, FR;
Jean-pierre Vairon, Bourg la Reine, FR;
Bernadette Charleux, Vincennes, FR;
Pascale Tardieu, Paris, FR;
Sylvette Maisonnier, Moisselles, FR;
Jean-paul Cano, Chennevieres sur Marne, FR;
Nathaly Vassal, Paris, FR;
Jean-Pierre Vairon, Bourg la Reine, FR;
Bernadette Charleux, Vincennes, FR;
Pascale Tardieu, Paris, FR;
Sylvette Maisonnier, Moisselles, FR;
Jean-Paul Cano, Chennevieres sur Marne, FR;
Essilor International Compagnie Generale d'Optique, Charenton-le-Pont, FR;
Abstract
The method of the invention comprises: a) forming a hydrophilic polyurethane prepolymer with isocyanate end groups, by the polyaddition reaction of at least one polyol and at least one diisocyanate in the presence of at least one internal emulsifying agent; b) mixing the polyurethane prepolymer with a photochromic agent; c) adding water or a mixture of water and solvent, under agitation, to the mixture of the polyurethane prepolymer and the photochromic agent, to form an emulsion; and d) adding at least one chain extension agent to the emulsion and performing a chain extension reaction to give the final photochromic polyurethane latex. Application to the production of ophthalmic articles having photochromic properties.