US4332888A
Expired / Lapsed
US
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Method for stabilizing and spectrally sensitizing photosensitive silver halide emulsion
Assignee: Polaroid Corp
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Filing: 1980-02-15
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Granted: 1982-06-01
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Expires: 2000-02-15
Abstract
Abstract Photosensitive silver halide emulsions are provided with enhanced stability by the following sequence of steps: (a) providing sufficient stabilizer to the emulsion to stop chemical ripening but insufficient to interfere with spectral sensitization; (b) spectrally sensitizing said emulsion; and (c) adding to said emulsion a water soluble bromide salt, 1-phenyl-5-mercaptotetrazole; and a stabilizer selected from the group consisting of an hydroxy triazaindene, an amino triazaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene.
Inventors
- 👤 Leo D. Corben
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:59
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/34
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
85 words
A method for stabilizing a photosensitive silver halide emulsion which comprises the following steps, in sequence: (a) adding to said emulsion a stabilizer in an amount sufficient to substantially arrest chemical ripening but insufficient to interfere with spectral sensitization; (b) spectrally sensitizing said emulsion; and (c) adding to said spectrally sensitized emulsion a water-soluble bromide salt, 1-phenyl-5-mercaptotetrazole and a stabilizer selected from the group consisting of an hydroxy triazaindene, an amino triazaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene.
Claim 2
Independent Claim
85 words
A method for stabilizing a photosensitive silver halide emulsion which comprises the following steps, in sequence: (a) adding to said emulsion a stabilizer in an amount sufficient to substantially arrest chemical ripening but insufficient to interfere with spectral sensitization; (b) spectrally sensitizing said emulsion; and (c) adding to said spectrally sensitized emulsion a water-soluble bromide salt, 1-phenyl-5-mercaptotetrazole and a stabilizer selected from the group consisting of an hydroxy triazaindene, an amino triazaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene.
Claim 3
Independent Claim
123 words
A method for stabilizing a photosensitive silver halide emulsion which comprises the following steps, in sequence: (a) adding to said emulsion a water-soluble bromide salt and a stabilizer selected from the group consisting of an hydroxy triazaindene, an amino trizaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene; said bromide salt and said stabilizer being added in an amount sufficient to substantially arrest chemical ripening but insufficient to interfere with spectral sensitization; (b) spectrally sensitizing said emulsion; and (c) adding to said spectrally sensitized emulsion a water-soluble bromide salt, 1-phenyl-5-mercaptotetrazole and a stabilizer selected from the group consisting of an hydroxy triazaindene, an amino triazaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene.
Claim 4
Independent Claim
123 words
A method for stabilizing a photosensitive silver halide emulsion which comprises the following steps, in sequence: (a) adding to said emulsion a water-soluble bromide salt and a stabilizer selected from the group consisting of an hydroxy triazaindene, an amino trizaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene; said bromide salt and said stabilizer being added in an amount sufficient to substantially arrest chemical ripening but insufficient to interfere with spectral sensitization; (b) spectrally sensitizing said emulsion; and (c) adding to said spectrally sensitized emulsion a water-soluble bromide salt, 1-phenyl-5-mercaptotetrazole and a stabilizer selected from the group consisting of an hydroxy triazaindene, an amino triazaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene.
Claim 5
Dependent Claim
13 words
The method of claim 2 wherein said water-soluble bromide salt is ammonium bromide.
Claim 6
Dependent Claim
13 words
The method of claim 2 wherein said water-soluble bromide salt is potassium bromide.
Claim 7
Dependent Claim
13 words
The method of claim 2 wherein said stabilizer in step (a) comprises triazaindolizine.
Claim 8
Dependent Claim
15 words
The method of claim 5 wherein said triazaindolizine is a combination of 5,7-dimethyl-1,3,4-triazaindolizine and 5-methyl-7-hydroxy-1,3,4-triazaindolizine.
Claim 9
Dependent Claim
13 words
The method of claim 2 wherein said stabilizer in step (c) is 5-methyl-7-hydroxy-1,3,4-triazaindolizine.
Claim 10
Dependent Claim
19 words
The method of claim 2 wherein the emulsion prior to step (a) has been chemically ripened to optimum speed.
Claim 11
Dependent Claim
22 words
The method of claim 8 wherein steps a, b and c are carried out at a pH of about 5.0 to 5.8.
Claim 12
Dependent Claim
11 words
The method of claim 9 wherein said pH is about 5.5.
Claim 13
Dependent Claim
35 words
The method of claim 2 wherein in step (a) said water-soluble bromide is present at a level of about 1-5 mg/g silver and said stabilizer is present at a level of about 1-7 mg/g silver.
Claim 14
Dependent Claim
30 words
The method of claim 11 wherein said water-soluble bromide is present at about a level of 3 mg/g silver and said stabilizer at a level of about 6 mg/g silver.
Claim 15
Dependent Claim
44 words
The method of claim 2 wherein in step (c) water-soluble bromide is at a level of about 5-15 mg/g of silver; said 1-phenyl-5-mercaptotetrazole is at a level of about 0.1-0.5 mg/g silver and said stabilizer is at a level of about 20-40 mg/g silver.
Claim 16
Dependent Claim
34 words
The method of claim 2 wherein subsequent to step (b) and prior to step (c) said emulsion is held for a time sufficient to associate the spectral sensitizing dyes with the silver halide grains.
Claim 17
Dependent Claim
12 words
The method of claim 2 wherein said spectral sensitization is pan sensitization.
Claim 18
Independent Claim
135 words
A method for stabilizing a photosensitive silver bromoiodide emulsion which comprises the following steps, in sequence: (a) adding to said emulsion a water-soluble bromide salt and a stabilizer selected from the group consisting of an hydroxy triazaindene, an amino triazaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene; said bromide salt and said stabilizer being added in an amount sufficient to substantially arrest chemical ripening but insufficient to interfere with spectral sensitization; (b) spectrally sensitizing said emulsion; and (c) adding to said spectrally sensitized emulsion a water-soluble bromide salt, 1-phenyl-5-mercaptotetrazole and a stabilizer selected from the group consisting of an hydroxy trizazindene, an amino triazaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene; said steps being carried out at a pH of 5.0 to 5.8.
Claim 19
Independent Claim
135 words
A method for stabilizing a photosensitive silver bromoiodide emulsion which comprises the following steps, in sequence: (a) adding to said emulsion a water-soluble bromide salt and a stabilizer selected from the group consisting of an hydroxy triazaindene, an amino triazaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene; said bromide salt and said stabilizer being added in an amount sufficient to substantially arrest chemical ripening but insufficient to interfere with spectral sensitization; (b) spectrally sensitizing said emulsion; and (c) adding to said spectrally sensitized emulsion a water-soluble bromide salt, 1-phenyl-5-mercaptotetrazole and a stabilizer selected from the group consisting of an hydroxy trizazindene, an amino triazaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene; said steps being carried out at a pH of 5.0 to 5.8.
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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) | 1985-05-31 | 1985-11-30 | 1986-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-31 | 1989-11-30 | 1990-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-31 | 1993-11-30 | 1994-06-01 | $7700.00 | Window Closed / Lapsed |