Photochromic compositions
A photochromic composition having at least one photochromic naphthopyran-based component with R′ and R″ groups selected from hydrogen, alkyl, fluorinated alkyl, alkenyl, alkynyl, alkylaryl, cycloalkyl, alkoxy, halogen, amine, carbonate ester, carboxylate, aryl, substituted aryl, heteroaryl, substituted heteroaryl or a heterocyclic group and Ar′ and Ar″ groups selected from unsubstituted or substituted cyclic five-membered or six-membered structures including benzene, pyridine, thiophene, furan, carbazole, triphenylamine, dibenzothiophene, dibenzofuran, fluorine, naphthalene, anthracene and pyrene. The photochromic composition is excitable under a visible light range to produce a color change. A second photochromic naphthopyran-based component with a different thermal decay rate constant (k) may further be included in the photochromic composition. The photochromic composition is incorporated into color-changing inks and polymers.
1 . A photochromic composition including a first naphthopyran compound having one of the following formulae:
wherein the first naphthopyran compound has a thermal decay rate constant smaller than 1×10 −2 s −1 at room temperature and the photochromic composition is excitable under a visible light range to produce a color change.
2 . The photochromic composition of claim 1 , wherein the visible light has an intensity of approximately 200 W/m 2 or greater at a wavelength of approximately 300-450 nm.
3 . The photochromic composition of claim 1 , further comprising a second naphthopyran compound having a different excitation wavelength and thermal decay rate constant (k) than the first naphthopyran compound, the second naphthopyran compound having the following formula:
wherein the second naphthopyran compound has a thermal decay rate constant greater than 1×10 −2 s −1 at room temperature; and
wherein a ratio by weight percent between the first naphthopyran compound and the second naphthopyran compound ranges from 1:9 to 9:1.
4 . A photochromic printing ink selected from an offset ink, screen printing ink or inkjet printing ink, the photochromic printing ink comprising:
the photochromic composition of claim 1 in an amount of approximately 0.1 to 15 weight percent;
one or more polymers/resins in an amount of approximately 3 to 50 weight percent;
one or more additives in an amount from approximately 0 to 8 weight percent; and
a solvent in an amount of approximately 50 to 96.5 weight percent.
5 . The photochromic printing ink of claim 4 , wherein the one or more polymers/resins is/are selected from cellulose, starch, rubber, shellac, rosin modified phenolic resin.
6 . The photochromic printing ink of claim 4 , wherein the one or more additives is/are selected from waxes, dispersing powder, calcium carbonate, glycerol, ethoxylated or propoxylated fatty alcohols.
7 . The photochromic printing ink of claim 4 , wherein the solvent is selected from one or more of dichloromethane, esters, ketones, soybean oil, mineral oil, tung oil or linseed oil.
8 . A photochromic printing ink selected from an offset ink, screen printing ink or inkjet printing ink, the photochromic printing ink comprising:
the photochromic composition of claim 3 in an amount of approximately 0.5 to 20 weight percent;
one or more polymers/resins in an amount of approximately 3 to 50 weight percent;
one or more additives in an amount from approximately 0 to 8 weight percent; and
a solvent in an amount of approximately 50 to 96.5 weight percent.
9 . The photochromic printing ink of claim 8 , wherein the one or more polymers/resins is/are selected from cellulose, starch, rubber, shellac, rosin modified phenolic resin.
10 . The photochromic printing ink of claim 8 , wherein the one or more additives is/are selected from waxes, dispersing powder, calcium carbonate, glycerol, ethoxylated or propoxylated fatty alcohols.
11 . The photochromic printing ink of claim 8 , wherein the solvent is selected from one or more of dichloromethane, esters, ketones, soybean oil, mineral oil, tung oil or linseed oil.
12 . A photochromic polymeric material including the photochromic composition of claim 1 .
13 . The photochromic polymeric material of claim 12 , wherein the polymeric material includes one or more polymers selected from polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyamides, polyethylene terephthalate, polytetrafluoroethylene, poly (methyl methacrylate), polyphenylene sulfide, and polyether ether ketone, or rosin-modified phenolic resin.
14 . A photochromic polymeric material including the photochromic composition of claim 3 .
15 . The photochromic polymeric material of claim 14 , wherein the polymeric material includes one or more polymers selected from polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyamides, polyethylene terephthalate, polytetrafluoroethylene, poly (methyl methacrylate), polyphenylene sulfide, and polyether ether ketone, or rosin-modified phenolic resin.