Aminoplast resin photochromic coating composition and photochromic articles
AssigneePPG Industries Ohio, Inc.
InventorsKevin J. Stewart, Jeanine A. Conklin, Cletus N. Welch, James B. O'Dwyer, Shanti Swarup
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Abstract
Described are articles having an aminoplast resin photochromic coating prepared from an aminoplast resin, components(s) having hydroxyl functional groups and photochromic substances. The coatings exhibit a Fischer microhardness of from 45 to 180 Newtons per mm2 and desirable photochromic properties, i.e., the formation of darker activated colors and faster rates of photochromic activation and fade when irradiated with ultraviolet light. Also described are photochromic aminoplast resin articles.
Claims25
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 Fischerscope® H-100 using a 100 milliNewton load, 30 load steps and 0.5 second pauses and exhibiting a ΔOD 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 seconds—all as measured in the 85° F. Photochromic Performance Test.
A photochromic article comprising the polymerizate of a polymerizable composition 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 polymerizate being substantially free of cosmetic defects, said components being used in such proportions to produce a photochromic aminoplast resin polymerizate having a Fischer microhardness of from at least 45 to not more than 180 Newtons per mm2, as measured with a Fischerscope® H-100 using a 100 milliNewton load, 30 load steps and 0.5 second pauses and exhibiting an 85° F. ΔOD 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 seconds—all as measured in the 85° F. Photochromic Performance Test.
Dependencies are inferred from the claim text.