US4474872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing photographic emulsion
Assignee: Fujifilm Holdings Corp
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Filing: 1982-12-17
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Granted: 1984-10-02
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Expires: 2002-12-17
Abstract
Abstract A method for producing a photographic emulsion is disclosed. The method includes the process of adding a dispersion of a substantially water-insoluble photographic additive to a photographic emulsion. The dispersion being prepared merely by mechanically grinding and dispersing the photographic additive in a form of fine grain having a size of 1μ or less in an aqueous system adjusted to a pH value of 6 to 8 and controlled to a temperature of 60° to 80° C. The additive is included in the photographic emulsion without the need of an organic solvent. The emulsion of the invention can be easily and quickly coated to form a uniform layer.
Inventors
- 👤 Hiroshi Onishi
- 👤 Kazutoshi Inada
- 👤 Nobuaki Miyasaka
- 👤 Naoyasu Deguchi
- 👤 Masayuki Kuroishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:17
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
81 words
A method for producing a photographic emulsion, comprising the steps of: preparing a dispersion by mechanically grinding and dispersing a substantially water-insoluble photographic additive in a form of fine grain having mean particle size of 1μ or less in an aqueous system substantially free of organic solvents and surfactants, the aqueous system being adjusted to a pH value of 6 to 8 and controlled to a temperature of 60° C. to 80° C.; and adding the dispersion to a photographic emulsion.
Claim 2
Independent Claim
81 words
A method for producing a photographic emulsion, comprising the steps of: preparing a dispersion by mechanically grinding and dispersing a substantially water-insoluble photographic additive in a form of fine grain having mean particle size of 1μ or less in an aqueous system substantially free of organic solvents and surfactants, the aqueous system being adjusted to a pH value of 6 to 8 and controlled to a temperature of 60° C. to 80° C.; and adding the dispersion to a photographic emulsion.
Claim 3
Dependent Claim
21 words
A method for producing a photographic emulsion as claimed in claim 1, wherein the photographic emulsion is a hydrophilic colloid emulsion.
Claim 4
Dependent Claim
21 words
A method for producing a photographic emulsion as claimed in claim 1, wherein the photographic emulsion is a silver halide emulsion.
Claim 5
Dependent Claim
60 words
A method for producing a photographic emulsion as claimed in claim 1, wherein the substantially water-insoluble photographic additive is selected from the group consisting of a spectral sensitizing dye, an antifoggant, a color coupler, a dye, a sensitizer, a hardener, an ultraviolet absorbing agent, an antistatic agent, a brightening agent, a desensitizer, a developer, a discoloration inhibitor and a mordant.
Claim 6
Dependent Claim
21 words
A method for producing a photographic emulsion as claimed in claim 4, wherein the photographic additive is a spectral sensitizing dye.
Claim 7
Dependent Claim
28 words
A method for producing a photographic emulsion as claimed in claim 1, wherein the mechanical grinding and dispersing is carried out by means of a high speed agitator.
Claim 8
Dependent Claim
32 words
A method for producing a photographic emulsion as claimed in claim 1, wherein after preparing the dispersion the dispersion is mixed with a protective colloid and then added to the photographic emulsion.
Claim 9
Dependent Claim
19 words
A method for producing a photographic emulsion as claimed in claim 7, wherein the protective colloid is a gelatin.
Claim 10
Dependent Claim
40 words
A method for producing a photographic emulsion as claimed in claim 7, wherein after mixing the dispersion with the protective colloid the mixture is stored at a temperature of 30° C. or less and thereafter added to the photographic emulsion.
Claim 11
Dependent Claim
30 words
A method for producing a photographic emulsion as claimed in claim 1, wherein the dispersion is prepared by controlling the temperature within the range of 65° C. to 75° C.
Claim 12
Dependent Claim
28 words
A method for producing a photographic emulsion as claimed in claim 1, wherein the dispersion is prepared by maintaining the pH within the range of 6.5 to 7.5.
Claim 13
Dependent Claim
31 words
A method for producing a photographic emulsion as claimed in claim 1, wherein the photographic additive is in a form of fine grain having mean particle size of 0.1μ to 1μ.
References Cited (Backward Citations)
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Cited
GB1570362A
Cited
US4140530A
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US4146399A
Cited
US4291113A
Cited
US4284709A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-02 | 1988-04-02 | 1988-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-02 | 1992-04-02 | 1992-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-02 | 1996-04-02 | 1996-10-02 | $7700.00 | Window Closed / Lapsed |