US4338394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for hardening photographic gelatin
Assignee: Agfa Gevaert AG
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Filing: 1980-12-29
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Granted: 1982-07-06
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Expires: 2000-12-29
Abstract
Abstract Gelatin-containing layers of photographic materials are hardened by adding a compound containing from 2 to 6 sulfonyl ethyl sulfate groups in the form of its salts and activating the compound by adjusting a pH-value in the range from 6.5 to 11.
Inventors
- 👤 Wolfgang Himmelmann
- 👤 Peter Bergthaller
- 👤 Johannes Sobel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:40
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/30
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
123 words
A process for hardening a photographic silver halide material comprising of a support layer and at least one gelatin-containing layer applied thereto with a compound reacting with the amino groups of the gelatin as crosslinking agent, characterised in that a compound containing from 2 to 6 sulfonyl ethyl sulfate groups in the form of its salts is incorporated as crosslinking agent in the coating composition of the gelatin-containing layer(s) or the gelatin-containing layer(s) applied to the support layer, and in that the activity of the compound as a crosslinking agent is initiated by adjusting a pH-value in the range from 6.5 to 9 in the coating composition or in the range from 6.5 to 11 during the production process in the gelatin-containing layer.
Claim 2
Dependent Claim
123 words
A process for hardening a photographic silver halide material comprising of a support layer and at least one gelatin-containing layer applied thereto with a compound reacting with the amino groups of the gelatin as crosslinking agent, characterised in that a compound containing from 2 to 6 sulfonyl ethyl sulfate groups in the form of its salts is incorporated as crosslinking agent in the coating composition of the gelatin-containing layer(s) or the gelatin-containing layer(s) applied to the support layer, and in that the activity of the compound as a crosslinking agent is initiated by adjusting a pH-value in the range from 6.5 to 9 in the coating composition or in the range from 6.5 to 11 during the production process in the gelatin-containing layer.
Claim 3
Dependent Claim
113 words
A process as claimed in claim 1, characterised in that the crosslinking agent used is a compound corresponding to the following general formula Z(--Y--SO.sub.2 --CH.sub.2 --CH.sub.2 --OSO.sub.3.sup.⊖ Me.sup.⊕).sub.n in which Z represents a 2-valent to n-valent aliphatic, saturated or olefinically unsaturated straight- or branched chain C 1 -C 9 -hydrocarbon radical which may be substituted and which may contain oxy groups, a 2-valent to n-valent, 6-membered cycloaliphatic, aromatic or heterocyclic radical which may be substituted, or the group ##STR10## Y represents a single bond or, a branched or unbranched, C 1 -C 4 -alkylene group which may contain oxy, carbonyl and imino groups, and n is an integer of from 1 to 6.
Claim 4
Dependent Claim
34 words
A process as claimed in claim 1 or 2, characterised in that a pH-value of from 6.5 to 9 is adjusted by the addition of sodium tricarbonate or sodium acetate to the coating composition.
Claim 5
Dependent Claim
36 words
A process as claimed in claim 1 or claim 2, characterised in that the layer containing the crosslinking agent is overcoated with an aqueous buffer solution for a pH-value in the range from 6.5 to 11.
Claim 6
Dependent Claim
33 words
A process as claimed in claim 2, characterized in that said 6-membered cycloaliphatic, aromatic or heterocyclic radical which may be substituted is selected from the group consisting of cyclohexane, benzene, piperazine or hexahydrotriazine.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-05 | 1986-01-04 | 1986-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-05 | 1990-01-04 | 1990-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-05 | 1994-01-04 | 1994-07-06 | $7700.00 | Window Closed / Lapsed |