US3918972A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Imaging process utilizing a polyester polycondensate containing spiropyran photochromic groups
Assignee: Agfa Gevaert NV
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Filing: 1973-08-13
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Granted: 1975-11-11
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Expires: 1993-08-13
Abstract
Abstract Linear photochrome polycondensates of the polyester type are described which contain spiropyran photochromic groups as an integral part of the main polymer chain, have a glass transition temperature lower than 120*C and possess photochromic properties at or above their glass transition temperature. Manufacture of stabilized photochromic images by exposing a layer of the photochromic polycondensate at a temperature at least equal to the glass transition temperature of the photochromic polycondensate and immediately cooling the thus exposed layer below the glass transition temperature.
Inventors
- 👤 Georges Gerard Evens
- 👤 Georges Joseph Smets
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:25
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/72; G03C1/73; G03C1/733; C; C08; C08G; C08G63/00; C08G63/68; C08G63/685; C08G63/6854; C08G63/6856; Y; Y10; Y10S; Y10S430/00; Y10S430/163
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
12 words
A PROCESS FOR FORMING STABILIZED PHOTOCHROMIC IMAGES WHICH COMPRISES THE STEPS OF:
Claim 2
Dependent Claim
12 words
A PROCESS FOR FORMING STABILIZED PHOTOCHROMIC IMAGES WHICH COMPRISES THE STEPS OF:
Claim 3
Dependent Claim
69 words
PROVIDING A PHOTOGRAPHIC ELEMENT HAVING A LAYER OR STRATUM COMPRISING A PHOTOCHROMIC POLYESTER POLYCONDENSATE CONTAINING SPIROPYRAN PHOTOCHROMIC GROUPS AS AN INTEGRAL PART OF THE MAIN POLYCONDENSATE CHAIN SAID PHOTOCHROMIC POLYCONDENSATE HAVING A GLASS TRANSITION TEMPERATURE LOWER THAN 120*C POSSESSING PHOTOCHROMIC PROPERTIES AT OR ABOVE ITS GLASS TRANSITION TEMPRATURE, AND BEING DERIVED FROM THE POLYCONDENSATION OF A PHOTOCHROMIC COMPOUND CARRYING A HYDROXYALKYL GROUP ON EITHER SIDE OF SAID PHOTOCHROMIC GROUPS,
Claim 4
Dependent Claim
69 words
PROVIDING A PHOTOGRAPHIC ELEMENT HAVING A LAYER OR STRATUM COMPRISING A PHOTOCHROMIC POLYESTER POLYCONDENSATE CONTAINING SPIROPYRAN PHOTOCHROMIC GROUPS AS AN INTEGRAL PART OF THE MAIN POLYCONDENSATE CHAIN SAID PHOTOCHROMIC POLYCONDENSATE HAVING A GLASS TRANSITION TEMPERATURE LOWER THAN 120*C POSSESSING PHOTOCHROMIC PROPERTIES AT OR ABOVE ITS GLASS TRANSITION TEMPRATURE, AND BEING DERIVED FROM THE POLYCONDENSATION OF A PHOTOCHROMIC COMPOUND CARRYING A HYDROXYALKYL GROUP ON EITHER SIDE OF SAID PHOTOCHROMIC GROUPS,
Claim 5
Dependent Claim
34 words
IMAGE-WISE EXPOSING SAID PHOTOGRAHIC ELEMENT AT A TEMPERATURE AT LEAST EUQAL TO THE GLASS TRANSITION TEMPRATURE OF SAID PHOTOCHROMIC POLYCONDENSATE SO AS TO EFFECT COLOURATION OF SAID PHOTOCHROMIC POLYCONDENSATE IN THE EXPOSED AREAS AND
Claim 6
Dependent Claim
34 words
IMAGE-WISE EXPOSING SAID PHOTOGRAHIC ELEMENT AT A TEMPERATURE AT LEAST EUQAL TO THE GLASS TRANSITION TEMPRATURE OF SAID PHOTOCHROMIC POLYCONDENSATE SO AS TO EFFECT COLOURATION OF SAID PHOTOCHROMIC POLYCONDENSATE IN THE EXPOSED AREAS AND
Claim 7
Dependent Claim
45 words
A process according to claim 1, wherein the photochromic polycondensate is obtained by copolycondensation of 2,2-bis(4-hydroxyphenyl)-propane and a photochromic compound carrying two hydroxyalkyl groups on either side of the photochromic moiety with a di-acid chloride derived from a di-acid of the saturated dicarboxylic acid group.
Claim 8
Dependent Claim
34 words
image-wise exposing said photographic element at a temperature at least equal to the glass transition temperature of said photochromic polycondensate so as to effect colouration of said photochromic polycondensate in the exposed areas, and
Claim 9
Dependent Claim
34 words
image-wise exposing said photographic element at a temperature at least equal to the glass transition temperature of said photochromic polycondensate so as to effect colouration of said photochromic polycondensate in the exposed areas, and
Claim 10
Dependent Claim
30 words
immediately cooling the thus exposed photographic element to a temperature below the glass transition temperature of said photochromic polycondensate so as to stabilize the colouration formed in the exposed areas.
Claim 11
Dependent Claim
30 words
immediately cooling the thus exposed photographic element to a temperature below the glass transition temperature of said photochromic polycondensate so as to stabilize the colouration formed in the exposed areas.
Claim 12
Dependent Claim
18 words
A process according to claim 2, wherein the di-acid chloride is derived from pimelic acid or adipic acid.
Claim 13
Dependent Claim
30 words
IMMEDIATELY COOLING THE THUS EXPOSED PHOTOGRAPHIC ELEMENT TO A TEMPERATURE BELOW THE GLASS TRANSITION TEMPERATURE OF SAID PHOTOCHROMIC POLYCONDENSATE SO AS TO STABILIZE THE COLOURATION FORMED IN THE EXPOSED AREAS.
Claim 14
Dependent Claim
30 words
IMMEDIATELY COOLING THE THUS EXPOSED PHOTOGRAPHIC ELEMENT TO A TEMPERATURE BELOW THE GLASS TRANSITION TEMPERATURE OF SAID PHOTOCHROMIC POLYCONDENSATE SO AS TO STABILIZE THE COLOURATION FORMED IN THE EXPOSED AREAS.
Claim 15
Dependent Claim
14 words
A process according to claim 2, wherein the photochromic compound corresponds to the formula:
Claim 16
Dependent Claim
51 words
A process according to claim 1 wherein the photochromic polycondensate is the polycondensation reaction product of 2,2-bis(4-hydroxyphenyl)-propane and a photochromic compound having a hydroxyalkyl group on each side of the photochromic moiety with a dicarboxylic acid selected from the group consisting of succinic acid, adipic acid, glutaric acid, and pimelic acid.
Claim 17
Dependent Claim
13 words
A process according to claim 5 wherein the photochromic compound has the formula:
Claim 18
Dependent Claim
13 words
A process according to claim 5 wherein the photochromic compound has the formula:
Claim 19
Dependent Claim
13 words
A process according to claim 5 wherein the photochromic compound has the formula:
References Cited (Backward Citations)
US3652285A
Cited
US3696098A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |