Abrasion and/or Scratch Resistant Article Comprising an Impact Resistant Photochromic Polyurethane Coating, and Process of Preparation Thereof

Abstract

Processes for obtaining an impact resistant, abrasion and/or scratch resistant photochromic article comprising a substrate having two main faces, comprising: preparing a curable coating composition comprising at least one unblocked polyisocyanate terminated polyurethane pre-polymer, at least one polyol, and at least one photochromic agent; depositing the curable coating composition onto at least part of a main face of the substrate; curing the coating composition for 10 minutes or less, at a temperature lower than or equal to 100° C. to form an impact resistant photochromic coating; forming an abrasion and/or scratch resistant coating on the impact resistant photochromic coating or forming a protective coating on the impact resistant photochromic coating and then forming an abrasion and/or scratch resistant coating on said protective coating. Articles obtainable by such processes, including but not limited to ophthalmic lenses. Curable coating compositions involved in such processes.

1 - 35 . (canceled) 
   
   
       36 . A curable coating composition comprising at least one unblocked polyisocyanate terminated polyurethane pre-polymer, at least one polyol, and at least one photochromic agent. 
   
   
       37 . The composition of  claim 36 , further comprising at least one solvent. 
   
   
       38 . The composition of  claim 37 , wherein the solvent is N-methylpyrrolidone, tetrahydrofuran, acetonitrile, dioxane, or a mixture thereof. 
   
   
       39 . The composition of  claim 36 , wherein the polyol is a polyol with a number average molecular weight less than 400, a polyester polyol, a polyether polyol, a polyol containing an amide group, a polyacrylic polyol, an epoxypolyol, a polyvinyl polyol, or a urethane polyol. 
   
   
       40 . The composition of  claim 39 , wherein the polyol is a polyester polyol. 
   
   
       41 . The composition of  claim 36 , wherein the polyol has a number average molecular weight ranging from 400 to 10,000 g/mol. 
   
   
       42 . The composition of  claim 41 , wherein the polyol has a number average molecular weight ranging from 500 to 6,000 g/mol. 
   
   
       43 . The composition of  claim 40 , wherein the polyester polyol is prepared by the reaction of a polyol and a lactone. 
   
   
       44 . The composition of  claim 43 , wherein the lactone is s-caprolactone, propiolactone or butyrolactone. 
   
   
       45 . The composition of  claim 43 , wherein the polyol is neopentyl glycol, trimethylol propane, diethylene glycol, or glycerol. 
   
   
       46 . The composition of  claim 36 , wherein the polyol has at least three hydroxyl groups. 
   
   
       47 . The composition of  claim 46 , wherein the polyol is a polycaprolactone triol. 
   
   
       48 . The composition of  claim 36 , wherein the polyurethane pre-polymer is obtained by the reaction of an excess of at least one polyisocyanate with at least one polyol. 
   
   
       49 . The composition of  claim 48 , wherein the polyisocyanate and polyol for obtaining the polyurethane pre-polymer are used in an amount such that the molar ratio of NCO to OH groups is from 2:1 to 8:1. 
   
   
       50 . The composition of  claim 48 , wherein the polyisocyanate is a diisocyanate. 
   
   
       51 . The composition of  claim 48 , wherein the polyisocyanate is an aliphatic diisocyanate further defined as hexamethylene-1,6-diisocyanate, isophorone diisocyanate, ethylene diisocyanate, dodecane-1,12-diisocyanate, cyclohexane-1,3-diisocyanate, or bis-(4-isocyanato-cyclohexyl)-methane. 
   
   
       52 . The composition of  claim 36 , wherein the polyurethane pre-polymer has a number average molecular weight of from 1,000 to 6,000 g/mol. 
   
   
       53 . The composition of  claim 36 , wherein the polyol and the unblocked polyisocyanate terminated polyurethane pre-polymer are used in an amount such that the molar ratio of NCO to OH groups is from 0.8 to 1.2. 
   
   
       54 . The composition of  claim 36 , wherein the photochromic compound is an organic compound further defined as an oxazine derivative, a chromene, photochromic derivative of chromene, fulgide, fulgimide, or organometallic derivative of dithizonate. 
   
   
       55 . The composition of  claim 36 , wherein the photochromic compound is a spirooxazine, further defined as a spiro[indolino]benzoxazine, a spiro[indolino]naphtoxazine, or a spiro[indolino]pyridobenzoxazine. 
   
   
       56 . The composition of  claim 36 , further defined as comprising at least one catalyst further defined as a tin catalyst or amine catalyst. 
   
   
       57 . An impact resistant photochromic polyurethane film obtainable by curing a curable coating composition of  claim 36 . 
   
   
       58 . The film of  claim 57 , further defined as having a thickness of from 0.05 to 150 μm. 
   
   
       59 . An abrasion and/or scratch resistant article comprising a substrate having two main faces, at least one of which being coated with an impact resistant photochromic polyurethane coating in which at least one photochromic compound is dispersed, said photochromic polyurethane coating being coated with an abrasion and/or scratch resistant coating or a protective coating itself coated with an abrasion and/or scratch resistant coating, wherein said article is obtainable by a process comprising:
 preparing a curable coating composition according to  claim 36 ;   depositing the prepared curable coating composition onto at least part of a main face of the substrate;   curing said curable coating composition for 10 minutes or less, at a temperature lower than or equal to 100° C. so as to form an impact resistant photochromic coating; and   forming an abrasion and/or scratch resistant coating on the impact resistant photochromic coating or forming a protective coating on the impact resistant photochromic coating and then forming an abrasion and/or scratch resistant coating on said protective coating.   
   
   
       60 . The article of  claim 59 , further defined as an ophthalmic lens.