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US 11,168,223 B2Granted
Photochromic article
AssigneeSDC Technologies, Inc.
InventorsQuang Phan, Erdem Cetin, Ren-Zhi Jin, Sapna Blackburn
Life of this patent
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Abstract
Disclosed are articles having a thermoplastic photochromic coating. The articles exhibit a Bayer Abrasion ratio of at least 2 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.
Claims16
A photochromic article comprising:
- a) a substrate;
- b) a thermoplastic photochromic coating composition solidified on at least one surface of the substrate to form a photochromic coating, the photochromic coating composition comprising
- i) a thermoplastic acrylic copolymer wherein the copolymer or at least one segment of the copolymer has a Tg below 55° C., wherein the copolymer is an ABA triblock copolymer and A is poly(methyl methacrylate-co-dialkylacrylamide) and B is poly(butyl acrylate);
- ii) one or more photochromic compounds;
- and
- iii) a non-reactive organic solvent;
- wherein the total amount of photochromic compound(s) is at least 40 parts by weight per 100 parts by weight of the total amount of thermoplastic acrylic copolymer in the coating composition, wherein the photochromic coating has a thickness of from 3 to 20 micrometers;
- c) an optional first organic adhesion promoter layer interposed between the substrate and the photochromic coating;
- d) a protective polymeric hard coating superposed over the photochromic coating;
- and
- e) an optional second organic adhesion promoter layer interposed between the photochromic coating and the protective hard coating.
8 more elements
A method for preparing a photochromic article comprising:
- a) applying and solidifying a thermoplastic photochromic coating composition on at least one surface of a substrate to form a thermoplastic photochromic coating, the photochromic coating composition comprising
- i) a thermoplastic acrylic copolymer wherein the copolymer or at least one copolymer segment has a Tg below 55° C., wherein the copolymer is an ABA triblock copolymer and A is a poly(methyl methacrylate-co-dialkylacrylamide) and B is a poly(butyl acrylate);
- ii) one or more photochromic compounds;
- and
- iii) a non-reactive organic solvent;
- wherein the total amount of photochromic compound(s) is at least 40 parts by weight per 100 parts by weight of the total amount of thermoplastic acrylic copolymer in the coating composition, wherein the thermoplastic photochromic coating has a thickness of from 3 to 20 micrometers;
- b) optionally applying and solidifying a first organic adhesion promoter layer on the at least one surface of the substrate prior to applying the photochromic coating such that the first organic adhesion promoter layer is interposed between the substrate and the photochromic coating;
- c) applying and solidifying a protective polymeric hard coating superposed over the photochromic coating;
- and
- d) optionally applying and solidifying a second organic adhesion promoter layer on the photochromic coating prior to applying the protective polymeric hard coating such that the second organic adhesion promoter layer is interposed between the photochromic coating and the protective hard coating.
7 more elements
Dependencies are inferred from the claim text.