US3873314A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of clean polyester materials from photographic film
Assignee: Horizons Inc
•
Filing: 1972-11-07
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Granted: 1975-03-25
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Expires: 1992-11-07
Abstract
Abstract Polymers containing polyvinylidene halides are generally used as a subbing or anchoring layer between a polyester film base and a gelatin layer containing halides or other silver compounds. It has been found that the silver and silver compound containing gelatin layer can be separated cleanly from the polyester base with attendant removal of the polyvinylidene halide containing polymer from both the gelatin fractions and the polyester fraction by suitable treatment of the photographic film (whether exposed or unexposed) in polar aprotic solvents; somewhat less polar solvents comprising cyclic compounds taken from the class of aliphatic and aromatic hydrocarbons, ethers, sulfides, and ketones; and mixtures of polar aprotic solvents such as sulfoxides or amides in combination with the cyclic solvents as cosolvents. These solvents dissolve the polyvinylidene containing polymer while not affecting materially either the polyester base or the silver compound or silver metal containing gelatin layer. Of this group of solvents the polar aprotic solvents are the preferred species; mixtures of polar aprotic solvents and polar cyclic compounds being preferred next; and cyclic organic compounds which are less polar being the least preferred in view of the relatively high temperature required for suitable action. The preferred solvents are effective at room temperature, at elevated temperature below the boiling point of the solvent and in the vapor phase above the boiling point of the solvent.
Inventors
- 👤 James T K Woo
- 👤 Donald E Glowe
- 👤 J Scott Thornton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:14
CPC Classifications
G; G03; G03C; G03C11/00; G03C11/24; C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; C08J11/08; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/582; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
159 words
A PROCESS FOR THE RECOVERY OF VALUABLE CONSTITUTENTS OF PHOTOGRAPHIC FILM CONSISTING OF A POLYESTER FILM BASE COATED ON AT LEAST ONE SURFACE WITH A SUBBING LAYER OF VINYLIDENE TERPOLYMER MATERIAL TO WHICH A GELATING SILVER HALIDE COATING HAS BEEN APPLIED AS AN OVERCOATING, WHICH PROCESS CONSISTS OF: PREHEATING SMALL PIECES OF SAID FILM TO A TEMPERATURE SUFFICIENT TO RREMOVE WATER FROM HE GELATIN LAYER; CONTACTING SMALL PIECES OF SAID PREVIOUSLY HEATED FILM WITH A POLAR APROTIC SOLVENT FOR DISSOLVING THE TERPOLYMER SUBBING LAYER; MAINTAINING SAID PIECES OF FILM IN CONTACT WITH SAID POLAR APROTIC SOLVENT AT ABOUT ROOM TEMPERATURE UNTIL DISSOLUTION OF SAID TERPOLYMER SUBBING LAYER IS COMPLETED AND THE GELATIN SILVER HALIDE OVERCOATING HAS BEEN DETACHED FROM THE FILM BASE; THEREAFTER STIRRING THE RESULTING MIXTURE VIOLENTLY TO BREAK UP THE DETACHED GELATIN SILVER HALIDE COATING; AND SEPARATELY RECOVERING SAID (1) POLYESTER FILM BASE, (2) DETACHED GELATIN COATING AND THE SILVER THEREIN, AND (3) SAID TERPOLYMER SUBBING MATERIAL.
Claim 2
Dependent Claim
159 words
A PROCESS FOR THE RECOVERY OF VALUABLE CONSTITUTENTS OF PHOTOGRAPHIC FILM CONSISTING OF A POLYESTER FILM BASE COATED ON AT LEAST ONE SURFACE WITH A SUBBING LAYER OF VINYLIDENE TERPOLYMER MATERIAL TO WHICH A GELATING SILVER HALIDE COATING HAS BEEN APPLIED AS AN OVERCOATING, WHICH PROCESS CONSISTS OF: PREHEATING SMALL PIECES OF SAID FILM TO A TEMPERATURE SUFFICIENT TO RREMOVE WATER FROM HE GELATIN LAYER; CONTACTING SMALL PIECES OF SAID PREVIOUSLY HEATED FILM WITH A POLAR APROTIC SOLVENT FOR DISSOLVING THE TERPOLYMER SUBBING LAYER; MAINTAINING SAID PIECES OF FILM IN CONTACT WITH SAID POLAR APROTIC SOLVENT AT ABOUT ROOM TEMPERATURE UNTIL DISSOLUTION OF SAID TERPOLYMER SUBBING LAYER IS COMPLETED AND THE GELATIN SILVER HALIDE OVERCOATING HAS BEEN DETACHED FROM THE FILM BASE; THEREAFTER STIRRING THE RESULTING MIXTURE VIOLENTLY TO BREAK UP THE DETACHED GELATIN SILVER HALIDE COATING; AND SEPARATELY RECOVERING SAID (1) POLYESTER FILM BASE, (2) DETACHED GELATIN COATING AND THE SILVER THEREIN, AND (3) SAID TERPOLYMER SUBBING MATERIAL.
Claim 3
Dependent Claim
17 words
The process of claim 1 in which a mixture of polar aprotic and cyclic solvents is used.
Claim 4
Dependent Claim
25 words
The process of claim 1 in which the pieces of film are preheated to up to 120*C before being introduced into contact with the solvent.
Claim 5
Dependent Claim
24 words
The process of claim 1 in which the polyester base of the pieces of film is separated from the other materials present by screening.
Claim 6
Dependent Claim
40 words
The process of claim 1 in which the silver is recovered from the gelatin containing material which has separated and become detached from the pieces of film by effecting flameless combustion of said gelatin containing material admixed with ammonium nitrate.
Claim 7
Dependent Claim
23 words
The process of claim 1 in which the stirred mixture is maintained at a temperature between about 80* and 120*C during said stirring.
Claim 8
Dependent Claim
136 words
A PROCESS FOR TE RECOVERY OF VALUABLE CONSTITUENTS OF PHOTOGRAPHIC FILM CONSISTING OF A POLYESTER FILM BASE COATED ON AT LEAST ONE SURFACE WITH A SUBBING LAYER OF TERPOLYMER MATERIAL TO WHICH A GELATING SILVER HALIDE COATING HAS BEEN APPLIED AS AN OVERCOATING, WHICH PROCESS CONSISTS OF: CONTACTING SMALL PIECES OF SAID FILM WITH A HEATED POLAR APROTIC SOLVENT FFOR DISSOLVING THE TERPOLYMER SUBBING LAYER; MAINTAINING SAID PIECES OF FILM IN CONTACT WITH SAID HEATED SOLVENT AT A TEMPERATURE SUFFICIENT FOR A SUBSTANTIAL EVOLUTION OF WATER FROM SAID GELATIN LAYER AND UNTIL DISSOLUTION OF THE TERPOLYMER SUBBING LAYER IS COMPLETED AND THE GELATIN SILVER HALIDE OVERCOATING HAS BEEN DETACHED FROM THE FILM BASE; AND SEPARATELY RECOVERING (1) SAID POLYESTER FILM BASE, (2) SAID DETACHED GELATING COATING AND THE SILVER THEREIN, AND (3) SAID TERPOLYMER SUBBING MATERIAL.
Claim 9
Dependent Claim
136 words
A PROCESS FOR TE RECOVERY OF VALUABLE CONSTITUENTS OF PHOTOGRAPHIC FILM CONSISTING OF A POLYESTER FILM BASE COATED ON AT LEAST ONE SURFACE WITH A SUBBING LAYER OF TERPOLYMER MATERIAL TO WHICH A GELATING SILVER HALIDE COATING HAS BEEN APPLIED AS AN OVERCOATING, WHICH PROCESS CONSISTS OF: CONTACTING SMALL PIECES OF SAID FILM WITH A HEATED POLAR APROTIC SOLVENT FFOR DISSOLVING THE TERPOLYMER SUBBING LAYER; MAINTAINING SAID PIECES OF FILM IN CONTACT WITH SAID HEATED SOLVENT AT A TEMPERATURE SUFFICIENT FOR A SUBSTANTIAL EVOLUTION OF WATER FROM SAID GELATIN LAYER AND UNTIL DISSOLUTION OF THE TERPOLYMER SUBBING LAYER IS COMPLETED AND THE GELATIN SILVER HALIDE OVERCOATING HAS BEEN DETACHED FROM THE FILM BASE; AND SEPARATELY RECOVERING (1) SAID POLYESTER FILM BASE, (2) SAID DETACHED GELATING COATING AND THE SILVER THEREIN, AND (3) SAID TERPOLYMER SUBBING MATERIAL.
Claim 10
Dependent Claim
143 words
A PROCESS FOR THE RECOVERY OF VALUABLE CONSTITUENTS OF PHOTOGRAPHIC FILM CONSISTING OF A POLYESTER FILM BASE COATED ON AT LEAST ONE SURFACE WITH SUBBING LAYER OF A VINYLIDENE TERPOLYMER MATERIAL TO WHICH A GELATIN SILVER HALIDE COATING HAS BEEN APPLIED AS AN OVERCOATING, WHICH PROCESS CONSISTS OF: CONTACTING SMALL PIECES OF SAID FILM WITH A VAPORIZED POLAR APROTIC SOLVENT FOR DISSOLVING THE TERPOLYMER SUBBING LAYER; MAINTAINING SAID PIECES OF FILM IN CONTACT WITH SAID VAPORIZED SOLVENT AT A TEMPERATURE ABOVE THE BOILING POINT OF THE SOLVENT UNTIL DISSOLUTION OF THE TERPOLMER SUBBING LAYER IS COMPLETED AND SUBSTANTIALLY AMOUNTS OF WATER HAVING BEEN ELIMINATED FROM THE GELATING AND THE GELATIN SILVER HALIDE OVERCOATING HAS BEEN DETACHED FROM THE FILM BASE; AND SEPARATELY RECOVERING (1) SAID POLYESTER FILM BASE, (2) SAID DETACHED GELATIN COATING AND THE SILVER THEREIN, AND (3) SAID TERPOLYMER SUBBING MATERIAL.
Claim 11
Dependent Claim
143 words
A PROCESS FOR THE RECOVERY OF VALUABLE CONSTITUENTS OF PHOTOGRAPHIC FILM CONSISTING OF A POLYESTER FILM BASE COATED ON AT LEAST ONE SURFACE WITH SUBBING LAYER OF A VINYLIDENE TERPOLYMER MATERIAL TO WHICH A GELATIN SILVER HALIDE COATING HAS BEEN APPLIED AS AN OVERCOATING, WHICH PROCESS CONSISTS OF: CONTACTING SMALL PIECES OF SAID FILM WITH A VAPORIZED POLAR APROTIC SOLVENT FOR DISSOLVING THE TERPOLYMER SUBBING LAYER; MAINTAINING SAID PIECES OF FILM IN CONTACT WITH SAID VAPORIZED SOLVENT AT A TEMPERATURE ABOVE THE BOILING POINT OF THE SOLVENT UNTIL DISSOLUTION OF THE TERPOLMER SUBBING LAYER IS COMPLETED AND SUBSTANTIALLY AMOUNTS OF WATER HAVING BEEN ELIMINATED FROM THE GELATING AND THE GELATIN SILVER HALIDE OVERCOATING HAS BEEN DETACHED FROM THE FILM BASE; AND SEPARATELY RECOVERING (1) SAID POLYESTER FILM BASE, (2) SAID DETACHED GELATIN COATING AND THE SILVER THEREIN, AND (3) SAID TERPOLYMER SUBBING MATERIAL.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |