Patent ID: 6506488
Filing Date: 2003-01-14
Classification: C09K,G02B,Y10S,Y10T

Abstract:
An article comprising, in combination, a substrate and a cured photochromic aminoplast resin coating on at least one surface of said substrate, said coating being prepared by combining components comprising:(a) component comprising molecules having at least 2 hydroxyl groups per molecule; (b) aminoplast component comprising molecules having at least two reactive groups per molecule; and (c) a photochromic amount of photochromic component(s); provided that said components are combined without reacting said components before combining, said cured coating being substantially free of cosmetic defects, said components being used in such proportions to produce a photochromic aminoplast resin coating having a Fischer microhardness of from at least 45 to not more than 180 Newtons per mm2, as measured with a FischerscopeÂ® H-100 using a 100 milliNewton load, 30 load steps and 0.5 second pauses and exhibiting 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.