US3715214A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rapid development process
Assignee: AB Dick Co
•
Filing: 1970-05-18
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Granted: 1973-02-06
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Expires: 1990-05-18
Abstract
Abstract A process and compositions for rapidly developing and fixing a high contrast, low speed photographic film such as microfilm. The first step in the process comprises contact of an exposed photographic film with an alkaline developer composition comprising (a) a mixture of hydroquinone and 1-phenyl-3-pyrazolidone in a weight ratio of from 15:1 to 6:1 as the developing agent, the mixture contained in the developer composition in an amount of from 15 to 40 grams per liter; and (b) potassium sulfite as preservative in an amount from 60 to 120 grams per liter. Preferably, the developer composition has a pH from about 10 to 11 and contains a restrainer such as potassium bromide in an amount of from 2 to 10 grams per liter. Following contact with the developer composition, the developed film is preferably contacted with a fixer such as one comprising from 200 to 400 grams per liter sodium thiosulfate crystals, 50 to 100 grams per liter of potassium sulfite and 100 to 200 grams per liter of ammonium thiocyanate. The process of the invention provides rapid development of high contrast, low speed films and has, for example, a capability of developing microfilm in about 10 seconds or less. The high speed is believed to be attributable, at least in part, to the use of the above-noted combination of developing agents. Moreover, the process results in a developed negative free of a uniform red coloration or stain characteristic of films of this nature. Finally, the developer composition is highly resistant to the detrimental effects of aeration, has excellent keeping qualities and can be stored for long periods of time without noticeable deterioration.
Inventors
- 👤 J Kane
- 👤 H Morse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:28
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/30
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
85 words
A process for developing a silver halide photographic film comprising exposing the film, contacting with an alkaline developer composition comprising (a) a mixture of hydroquinone and 1-phenyl-3-pyrazolidone in a weight ratio of from about 15:1 to 6:1 as developing agents, the mixture of agents contained in the developer composition present in an amount of from 15 to 40 grams per liter of developer solution; and (b) potassium sulfite as a preservative in an amount of from 60 to 120 grams per liter of developer solution.
Claim 2
Dependent Claim
85 words
A process for developing a silver halide photographic film comprising exposing the film, contacting with an alkaline developer composition comprising (a) a mixture of hydroquinone and 1-phenyl-3-pyrazolidone in a weight ratio of from about 15:1 to 6:1 as developing agents, the mixture of agents contained in the developer composition present in an amount of from 15 to 40 grams per liter of developer solution; and (b) potassium sulfite as a preservative in an amount of from 60 to 120 grams per liter of developer solution.
Claim 3
Dependent Claim
29 words
The process of claim 1 wherein the developer composition comprises an alkali present in quanities to produce a developer composition having a pH of from about 10 to 11.
Claim 4
Dependent Claim
25 words
The process of claim 2 wherein the potassium sulfite is present in an amount of at least about 80 grams per liter of developer composition.
Claim 5
Dependent Claim
22 words
The process of claim 2 wherein the photographic film has a layer of dye disposed between a base and a photosensitive emulsion.
Claim 6
Dependent Claim
28 words
The process of claim 2 where the developer composition is maintained at between 85* and 95* F. and contact time with the photographic film is about 10 seconds.
Claim 7
Dependent Claim
15 words
The process of claim 2 where the developed film is contacted with a photographic fixer.
Claim 8
Dependent Claim
40 words
The process of claim 2 where the developer composition has approximately the following formulation: 1-phenyl-3-pyrazolidone 2.0 gr hydroquinone 27.0 gr potassium sulfite 90.0 gr alkali metal hydroxide 6.0 gr potassium bromide 4.0 gr benzatriazole 0.1 gr water to 1 litEr.
Claim 9
Dependent Claim
116 words
A process for developing an exposed low speed, high contrast photographic film including the steps of contacting the exposed film with a developer composition having the following formulation: Minimum Maximum 1-phenyl-3-pyrazolidone, gr 1.0 2.5 hydroquinone, gr 15.0 40.0 potassium sulfite, gr 60.0 120.0 potassium bromide, gr 2.0 10.0 sodium hydroxide, gr 4.0 15.0 benzotriazole, gr 0 0.5 water to 1 liter to 1 liter said hydroquinone and 1-phenyl-3-pyrazolidone being present in a weight ratio of from about 15:1 to 6:1, and contacting the developed film with a fixer having the following formulation: Minimum Maximum sodium thiosulfate crystals, gr 200 400 ammonium thiocyanate, gr 100 200 potassium sulfite, gr 50 100 water to 1 liter 1 liter.
Claim 10
Dependent Claim
116 words
A process for developing an exposed low speed, high contrast photographic film including the steps of contacting the exposed film with a developer composition having the following formulation: Minimum Maximum 1-phenyl-3-pyrazolidone, gr 1.0 2.5 hydroquinone, gr 15.0 40.0 potassium sulfite, gr 60.0 120.0 potassium bromide, gr 2.0 10.0 sodium hydroxide, gr 4.0 15.0 benzotriazole, gr 0 0.5 water to 1 liter to 1 liter said hydroquinone and 1-phenyl-3-pyrazolidone being present in a weight ratio of from about 15:1 to 6:1, and contacting the developed film with a fixer having the following formulation: Minimum Maximum sodium thiosulfate crystals, gr 200 400 ammonium thiocyanate, gr 100 200 potassium sulfite, gr 50 100 water to 1 liter 1 liter.
Claim 11
Dependent Claim
17 words
The process of claim 8 where the ratio of hydroquinone to 1-phenyl-3-pyrazolidone ranges from 15:1 to 6:1.
Claim 12
Dependent Claim
17 words
The process of claim 8 where the developer composition has a pH of from 10 to 11.
Claim 13
Dependent Claim
84 words
An alkaline developer composition for developing a low speed, high contrast silver halide photographic film comprising: (a) a mixture of hydroquinone and 1-phenyl-3-pyrazolidone in a weight ratio of from about 15:1 to 6:1 as developing agents, the mixture of agents contained in the developer composition being present in an amount of from about 15 to 40 grams per liter of developer composition and (b) potassium sulfite as a preservative in an amount of from about 60 to 120 grams per liter of developer composition.
Claim 14
Dependent Claim
84 words
An alkaline developer composition for developing a low speed, high contrast silver halide photographic film comprising: (a) a mixture of hydroquinone and 1-phenyl-3-pyrazolidone in a weight ratio of from about 15:1 to 6:1 as developing agents, the mixture of agents contained in the developer composition being present in an amount of from about 15 to 40 grams per liter of developer composition and (b) potassium sulfite as a preservative in an amount of from about 60 to 120 grams per liter of developer composition.
Claim 15
Dependent Claim
16 words
The composition of claim 11 wherein the composition has a pH from about 10 to 11.
Claim 16
Dependent Claim
27 words
The composition of claim 11 wherein the potassium sulfite is present in an amount of from about 80 to about 120 grams per liter of developer composition.
Claim 17
Dependent Claim
65 words
A composition for developing a low speed, high contrast photographic film as follows: Minimum Maximum 1-phenyl-3-pyrazolidone gr 1.0 2.5 hydroquinone gr 15.0 40.0 potassium sulfite gr 60.0 120.0 potassium bromide gr 2.0 10.0 sodium hydroxide gr 4.0 15.0 benzotriazole gr 0 0.5 water to 1 liter to 1 liter said hydroquinone and 1-phenyl-3-pyrazolidone being present in a weight ratio of from about 15:1 to 6:1.
Claim 18
Dependent Claim
65 words
A composition for developing a low speed, high contrast photographic film as follows: Minimum Maximum 1-phenyl-3-pyrazolidone gr 1.0 2.5 hydroquinone gr 15.0 40.0 potassium sulfite gr 60.0 120.0 potassium bromide gr 2.0 10.0 sodium hydroxide gr 4.0 15.0 benzotriazole gr 0 0.5 water to 1 liter to 1 liter said hydroquinone and 1-phenyl-3-pyrazolidone being present in a weight ratio of from about 15:1 to 6:1.
Claim 19
Dependent Claim
36 words
The composition of claim 14 having approximately a formulation as follows: 1-phenyl-3-pyrazolidone 2.3 gr hydroquinone 32.4 gr potassium sulfite 104 gr sodium hydroxide 6.95 gr potassium bromide 3.65 gr benzotriazole 0.16 gr water to 1 liter.
Claim 20
Dependent Claim
17 words
The composition of claim 14 where the ratio of hydroquinone to 1-phenyl-3-pyrazolidone ranges from 15:1 to 6:1.
Claim 21
Dependent Claim
13 words
The composition of claim 14 where the pH ranges from 10 to 11.
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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) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |