Patent ID: 6432544
Filing Date: 2002-08-13
Classification: C09K,G02B,G03C,Y10T

Abstract:
An article comprising, in combination, a substrate and a cured aminoplast resin coating containing photochromic compound(s) on at least one surface of said substrate, said photochromic aminoplast resin coating being prepared from a coating composition comprising:(a) a reaction product of (i) functional component(s) having groups reactive with aminoplast crosslinking agents selected from: (A) hydroxyl; (B) carbamate represented by the following structures: â€ƒwherein A is â€”Câ€” or â€”Oâ€”; R is hydrogen or C1-C18 alkyl, or R is bonded to A and forms part of a 5 or 6 membered ring; Râ€² is a C1-C18 alkyl; (C) urea represented by the following structure: â€ƒwherein B is â€”NHâ€”, Râ€³ is hydrogen or C1-C18 alkyl, or Râ€³ is bonded to B and forms part of a 5 or 6 membered ring; or (D) a mixture therof; provided that said functional component (a)(i) provides at least two different reactive groups selected from (A), (B), or (C); and (ii) aminoplast crosslinking agent having at least two reactive groups; and (b) a photochromic amount of photochromic compounds(s); said components (a)(i), (a)(ii) and (b) being used in such proprotions to produce a cured coating exhibiting a Fischer microhardness of from at least 45 to not more than 180 Newtons per mm2, and photochromic properties characterized by a &Dgr;OD of at least 0.15 after 30 seconds and at least 0.47 after 8 minutes, and a bleach rate of not more than 180 secondsâ€”all as measured in the 85Â° F. Photochromic Performance Test.