Multi-stage optical article
The present invention relates to optical articles that exhibit a uniform first transmittance when directly exposed to actinic radiation, such as sunlight; a gradient second percent transmittance when exposed to actinic radiation that has passed through an actinic radiation blocking or attenuating transparency (such as a vehicle windshield) interposed between the source of actinic radiation and the optical article; and a uniform third percent transmittance when free of exposure to actinic radiation. With the inventive optical articles, the uniform first percent transmittance is less than the uniform third percent transmittance. The present invention also relates to photochromic optical articles.
1. An optical article that exhibits:
a uniform first percent transmittance when said optical article is tested in the Outdoor Test,
a gradient second percent transmittance when said optical article is tested in the Behind the Windshield Test, and
a uniform third percent transmittance when said optical article is free of exposure to actinic radiation,
wherein said uniform first percent transmittance is less than said uniform third percent transmittance,
the optical article comprising:
(a) a substrate;
(b) a first layer positioned over at least a portion of said substrate, said first layer comprising a first photochromic material having a first unactivated state terminal minimum absorbance wavelength; and
(c) a second layer positioned over at least a portion of said first layer, said second layer comprising a second photochromic material having a second unactivated state terminal minimum absorbance wavelength,
wherein said second unactivated state terminal minimum absorbance wavelength is less than said first unactivated state terminal minimum absorbance wavelength, and
wherein said first layer provides said gradient second percent transmittance when said photochromic article is tested in the Behind the Windshield Test, and said second layer provides said uniform first percent transmittance when said photochromic article is tested in the Outdoor Test.
2. The optical article of claim 1 , wherein said optical article is a photochromic optical article.
3. The optical article of claim 1 , wherein
said first photochromic material has a first unactivated state absorbance of greater than 0 over at least a portion of wavelengths from 375 nm to 450 nm, and said first unactivated state terminal minimum absorbance wavelength is greater than 400 nm, and
said second photochromic material has a second unactivated state absorbance of greater than zero over at least a portion of wavelengths from 340 nm to less than 420 nm, and said second unactivated state terminal minimum absorbance wavelength is less or equal to than 415 nm.
4. The optical article of claim 3 , wherein
said first unactivated state terminal minimum absorbance is greater than 415 nm and less than or equal to 450 nm, and
said second unactivated state terminal minimum absorbance is greater than 375 nm and less than or equal to 415 nm.
5. The optical article of claim 1 , wherein said first layer has a gradient pattern of said first photochromic material.
6. The optical article of claim 1 , wherein
said first photochromic material is selected from the group consisting of a first photochromic compound, a first photochromic-dichroic compound, and combinations thereof, and
said second photochromic material is selected from the group consisting of a second photochromic compound, a second photochromic-dichroic compound, and combinations thereof.
7. The optical article of claim 6 , wherein at least one of:
said first photochromic-dichroic compound is at least partially aligned, or
said second photochromic-dichroic compound is at least partially aligned, or
said first photochromic-dichroic compound and said second photochromic-dichroic compound are each independently at least partially aligned.
8. The optical article of claim 1 , wherein said first layer and said second layer each independently further comprise at least one additive selected from dyes, alignment promoters, kinetic enhancing additives, photoinitiators, thermal initiators, polymerization inhibitors, solvents, light stabilizers, heat stabilizers, mold release agents, rheology control agents, leveling agents, free radical scavengers, adhesion promoters, blue light blockers, or combinations of two or more thereof.
9. The optical article of claim 1 , wherein said first photochromic material and said second photochromic material are each independently selected from indeno-fused naphthopyrans, naphtho [1,2-b]pyrans, naphtho [2,1-b]pyrans, spirofluoroeno [1,2-b]pyrans, phenanthropyrans, quinolinopyrans, fluoroanthenopyrans, spiropyrans, benzoxazines, naphthoxazines, spiro (indoline) naphthoxazines, spiro (indoline) pyridobenzoxazines, spiro (indoline) fluoranthenoxazines, spiro (indoline) quinoxazines, fulgides, fulgimides, diarylethenes, diarylalkylethenes, diarylalkenylethenes, or combinations of two or more thereof.
10. The optical article of claim 1 , further comprising at least one of: a primer layer; a topcoat layer; a hard coat layer; one or more antireflective layers; one or more alignment layers; or combinations thereof.
11. The optical article of claim 1 , wherein
said substrate comprises a first surface and a second surface, wherein said first surface and said second surface are opposed to each other,
said first layer is positioned over at least a portion of said first surface of said substrate, and
said optical article further comprises a back-layer comprising an ultraviolet light absorber, wherein said back-layer is positioned over at least a portion of said second surface of said substrate.
12. The optical article of claim 1 , wherein said optical article is selected from ophthalmic articles, display articles, windows, mirrors, active liquid crystal cell articles, or passive liquid crystal cell articles.
13. The optical article of claim 12 , wherein said optical article is selected from ophthalmic articles, and said ophthalmic articles are selected from corrective lenses, non-corrective lenses, contact lenses, intra-ocular lenses, magnifying lenses, protective lenses, or visors.
14. A method of making the optical article of claim 1 , comprising:
(a) applying the first layer comprising a gradient pattern of the first photochromic material over at least a portion of the substrate; and
(b) applying the second layer comprising the second photochromic material over at least a portion of the first layer to form the second layer, wherein the second layer has a substantially uniform concentration of the second photochromic material.