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, component(s) having at least two different 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.
Claims27
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:
- wherein A is —C— or —O—;
- R is hydrogen or C1-C18 alkyl, or R is bonded to A and forms part of a 5 or 6 membered ring;
- R′ is a C1-C18 alkyl;
- (C) urea represented by the following structure:
- wherein B is —NH—, R″ is hydrogen or C1-C18 alkyl, or R″ 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 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.
The article of claim 19 wherein the polymeric organic material is a solid transparent polymer selected from the group consisting of poly(methyl methacrylate), poly(ethylene glycol bismethacrylate), poly(ethoxylated bisphenol A dimethacrylate), thermoplastic polycarbonate, poly(vinyl acetate), polyvinylbutyral, polyurethane, polythiourethanes, and polymers of members of the group consisting of diethylene glycol bis(allyl carbonate) monomers, diethylene glycol dimethacrylate monomers, ethoxylated phenol methacrylate monomers, diisopropenyl benzene monomers, ethoxylated trimethylol propane triacrylate monomers and mixtures thereof.
A photochromic article comprising a polymerizate of a polymerizable 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:
- wherein A is —C— or —O—;
- R is hydrogen or C1-C18 alkyl, or R is bonded to A and forms part of a 5 or 6 membered ring;
- R′ is a C1-C18 alkyl;
- (C) urea represented by the following structure:
- wherein B is —NH—, R″ is hydrogen or C1-C18 alkyl, or R″ is bonded to B and forms part of a 5 or 6 membered ring;
- or
- (D) a mixture thereof;
- 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 compound(s), said components (a)(i), (a)(ii) and (b) being used in such proportions to produce a polymerizate exhibiting a Fischer microhardness of from at least 45 to not more than 180 Newtons per mm2, and photochromic properties characterized by 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.
Dependencies are inferred from the claim text.