Photochromic compositions of improved fatigue resistance
AssigneeTransitions Optical, Inc.
InventorsJohn S. Ligas, Michael S. Misura, Jr., Cletus N. Welch
Life of this patent
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Abstract
Photochromic optical articles of improved resistance to light fatigue are provided by the use of a combination of hindered amine light stabilizer and asymmetric diaryloxalamide light stabilizer with a mixture of (1) photochromic material having a minima luminous transmission in the range of 560 to 630 nanometers and (2) photochromic material having a minima luminous transmission in the range of 430 to 520 nanometers.
Claims22
A photochromic optical article of improved resistance to light fatigue comprising an organic polymeric host material and a photochromic composition comprising, in combination,
- (a) a photochromic amount of organic photochromic material having a minima luminous transmission in the range of 560 to 630 nanometers,
- (b) a photochromic amount of organic photochromic material having a minima luminous transmission in the range of 430 to 520 nanometers, and
- (c) from 0.3 to 1.5 parts, per part of organic photochromic material, of light stabilizers comprising, in combination,
- (1) hindered amine light stabilizer, and
- (2) asymmetric diaryloxalamide light stabilizer, the weight ratio of diaryloxalamide to hindered amine light stabilizer being from about 1:1 to about 3:1.
A photochromic optical article of improved resistance to light fatigue comprising a solid transparent organic polymeric host material and a photochromic composition comprising, in combination,
- (a) a photochromic amount of an organic photochromic material having a minima luminous transmission in the range of 580 to 620 nanometers,
- (b) a photochromic amount of an organic photochromic material having a minima luminous transmission in the range of 450 to 500 nanometers,
- (c) from 0.3 to 1.0 part, per part of organic photochromic material, of light stabilizers comprising, in combination,
- (1) hindered sine light stabilizer, and
- (2) asymmetric diaryloxalamide light stabilizer, the weight ratio of diaryloxalamide to hindered amine light stabilizer being from about 1:1 to about 3:1.
A photochromic optical article of improved resistance to light fatigue comprising an organic polymeric host material and a photochromic composition comprising, in combination,
- (a) a photochromic amount of photochromic material having a minima luminous transmission in the range of 560 to 630 nanometers,
- (b) a photochromic amount of photochromic material having a minima luminous transmission in the range of 430 to 520 nanometers, and
- (c) a stabilizing amount of stabilizer material comprising, in combination,
- (1) hindered amine light stabilizer, and
- (2) asymmetric diaryloxalamide light stabilizer, the weight ratio of diaryloxalamide to hindered amine light stabilizer being from about 1:1 to about 3:1.
Dependencies are inferred from the claim text.