US4012232A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized photochromic materials
Assignee: Individual
•
Filing: 1974-12-23
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Granted: 1977-03-15
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Expires: 1994-12-23
Abstract
Abstract Organic photochromic materials comprise a photochromic pigment stabilized with a protective inorganic coating which serves to protect the pigments from deactivation by exposure to moisture, oxygen, various plastic host materials, reactive chemicals or even normal atmospheric conditions. Useful organic photochromic pigments include the anils, hydrazones, semicarbozones, osazones, sydnones, fulgides and others. Inorganic coatings comprising such materials as zinc oxide, titanium dioxide, aluminum oxide, antimony oxide and silicon dioxide are useful in the preparation of photochromic plastic films, sheets, ophthalmic lenses such as lenses for sunglasses and in camera lenses and filters.
Inventors
- 👤 Donald R. Uhlmann
- 👤 Elias Snitzer
- 👤 Richard J. Hovey
- 👤 Nori Y.C. Chu
- 👤 Joseph T. Fournier, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:41
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0001; C09B67/0004; C09B67/0007; G; G02; G02B; G02B5/00; G02B5/20; G02B5/22; G02B5/23
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
80 words
A stabilized photochromic particle for incorporation into a plastic host to impart photochromic properties thereto, said particle comprising an organic photochromic pigment crystal having a diameter in the range of 30 A to 1 micron, said photochromic crystal having a protective coating on substantially the entire surface thereof effective to render the photochromic, crystal impervious to the effects of oxygen, moisture, monomers, catalysts, and other chemicals used in the formation of the plastic host which are deleterious to said crystal.
Claim 2
Dependent Claim
80 words
A stabilized photochromic particle for incorporation into a plastic host to impart photochromic properties thereto, said particle comprising an organic photochromic pigment crystal having a diameter in the range of 30 A to 1 micron, said photochromic crystal having a protective coating on substantially the entire surface thereof effective to render the photochromic, crystal impervious to the effects of oxygen, moisture, monomers, catalysts, and other chemicals used in the formation of the plastic host which are deleterious to said crystal.
Claim 3
Dependent Claim
38 words
A photochromic particle according to claim 1 wherein said particle is coated with an inorganic oxide material selected from the group consisting of silicon dioxide, titanium dioxide, aluminum oxide, antimony oxide, zinc oxide, inorganic glasses and mixtures thereof.
Claim 4
Dependent Claim
24 words
A photochromic particle according to claim 2 wherein said pigment is selected from the group consisting of anils, hydrazones, semicarbazones, osazones, sydnones and fulgides.
Claim 5
Dependent Claim
105 words
A material which exhibits photochromic properties comprising a plastic host having a plurality of photochromic particles incorporated therein, each of said photochromic particles comprising: an organic photochromic pigment crystal having a diameter in the range of 30 Angstroms to 1 micron; and a protective coating on substantially the entire surface of said photochromic crystal effective to render the photochromic crystal impervious to the effects of oxygen, moisture, monomers, catalysts, and other chemicals used in the formation of the plastic host which are deleterious to said crystal; the coatings on said crystals enabling the crystals to impart photochromic properties to said plastic hosts when incorporated therein.
Claim 6
Dependent Claim
105 words
A material which exhibits photochromic properties comprising a plastic host having a plurality of photochromic particles incorporated therein, each of said photochromic particles comprising: an organic photochromic pigment crystal having a diameter in the range of 30 Angstroms to 1 micron; and a protective coating on substantially the entire surface of said photochromic crystal effective to render the photochromic crystal impervious to the effects of oxygen, moisture, monomers, catalysts, and other chemicals used in the formation of the plastic host which are deleterious to said crystal; the coatings on said crystals enabling the crystals to impart photochromic properties to said plastic hosts when incorporated therein.
Claim 7
Dependent Claim
48 words
The material as set forth in claim 4 wherein the proportion of said material is 0.01 to 80 weight percent coated photochromic particles and wherein said plastic host comprises a substance selected from the group consisting of poly(allyl diglycol carbonate), polycarbonate, polymethylmethacrylate, cellulose acetate butyrate, and cellulose triacetate.
Claim 8
Dependent Claim
39 words
The photochromic material of claim 4 wherein each said photochromic particle is coated with an inorganic oxide material selected from the group consisting of silicon dioxide, titanium dioxide, aluminum oxide, antimony oxide, zinc oxide, inorganic glasses, and mixtures thereof.
Claim 9
Dependent Claim
23 words
A photochromic material of claim 5 wherein said pigment is selected from the group consisting of anils, hydrazones, semicarbazones, osazones, sydnones, and fulgides.
Claim 10
Dependent Claim
93 words
A process for producing a stabilized photochromic particle suitable for incorporation into a plastic host for imparting photochromic properties thereto, said process comprising: 1. forming an organic photochromic pigment crystal having a diameter in the range of about 30 A to about 1 micron; and, 2. depositing a thickness of an inorganic protective coating on substantially the entire surface of said crystal to render said photochromic particle impervious to the effects of oxygen, moisture, monomers, catalysts, and other chemicals used in the formation of synthetic plastic hosts which are deleterious to said crystal.
Claim 11
Dependent Claim
93 words
A process for producing a stabilized photochromic particle suitable for incorporation into a plastic host for imparting photochromic properties thereto, said process comprising: 1. forming an organic photochromic pigment crystal having a diameter in the range of about 30 A to about 1 micron; and, 2. depositing a thickness of an inorganic protective coating on substantially the entire surface of said crystal to render said photochromic particle impervious to the effects of oxygen, moisture, monomers, catalysts, and other chemicals used in the formation of synthetic plastic hosts which are deleterious to said crystal.
Claim 12
Dependent Claim
50 words
The process of claim 8 wherein said forming step (1) is effected by: a. forming a solution of an organic photochromic pigment; b. forming crystals of said pigment by evaporating the solvent from said solution; and c. reducing the size of said crystals to between 30 A and 1 micron.
Claim 13
Dependent Claim
23 words
The process as set forth in claim 9 wherein said crystal is reduced in size by comminuting said crystals by using a mill.
Claim 14
Dependent Claim
25 words
The process as set forth in claim 9 wherein said crystal is reduced in size by comminuting said crystals by using a fluid energy mill.
Claim 15
Dependent Claim
18 words
The process as set forth in claim 10 wherein said crystal is comminuted by using a colloid mill.
Claim 16
Dependent Claim
22 words
The process as set forth in claim 10 wherein said crystal is reduced in size by being comminuted in an attrition mill.
Claim 17
Dependent Claim
26 words
The process as set forth in claim 8 wherein said inorganic protective coating is deposited on said photochromic pigment particle by cathodic sputtering with a metal.
Claim 18
Dependent Claim
21 words
The process as set forth in claim 8 wherein said protective coating is deposited on said photochromic pigment by vacuum deposition.
Claim 19
Dependent Claim
23 words
The process as set forth in claim 8 wherein said inorganic coating is deposited on said photochromic pigment particle by chemical vapor deposition.
Claim 20
Dependent Claim
40 words
The process as set forth in claim 8 wherein said inorganic protective coating is deposited on said photochromic pigment particle by precipitation of a soluble form of an inorganic coating onto said particle and subsequent treatment to form the oxide.
Claim 21
Dependent Claim
29 words
The process as set forth in claim 8 wherein the organic photochromic pigment that is formed is N-(3-pyridyl)-sydnone and a coating of silicon dioxide is deposited on said crystal.
References Cited (Backward Citations)
US3810763A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-14 | 1980-09-13 | 1981-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-14 | 1984-09-13 | 1985-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-14 | 1988-09-13 | 1989-03-15 | $7700.00 | Window Closed / Lapsed |