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US4944966A
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Process for the hardening of photographic gelatin coatings and a composite hardener for gelatin-containing coatings
Assignee: Felex Schoeller Jr and GmbH and Co KG
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Filing: 1988-08-16
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Granted: 1990-07-31
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Expires: 2008-08-16
Abstract
Abstract A novel hardening agent for photographic gelatin coatings comprising a composite solution of a substituted 1,3,5 triazine and formaldehyde, in which the ratio of triazine to formaldehyde ranges from 1:0.1 to 1:0.7. The hardening agent may be added to the gelatin coating in the amount of 0.5 to 4 weight % based upon the gelatin content.
Inventors
- 👤 Hans Jerenz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:00
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/30
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
75 words
A process for hardening gelatin-containing photographic coatings and auxiliary coatings using an organic hardener comprising: preparing a premix hardening agent comprising a solution of an effective amount of a substituted 1,3,5 triazine and formaldehyde; aging said premix hardening agent at least one hour; adding said premix hardening agent to a photographic gelatin-containing solution after said aging of said premix hardening agent; and coating a paper base with said gelatin-containing solution containing the premix hardening agent.
Claim 2
Dependent Claim
75 words
A process for hardening gelatin-containing photographic coatings and auxiliary coatings using an organic hardener comprising: preparing a premix hardening agent comprising a solution of an effective amount of a substituted 1,3,5 triazine and formaldehyde; aging said premix hardening agent at least one hour; adding said premix hardening agent to a photographic gelatin-containing solution after said aging of said premix hardening agent; and coating a paper base with said gelatin-containing solution containing the premix hardening agent.
Claim 3
Dependent Claim
24 words
The process of claim 1 in which the ratio of substituted triazine to formaldehyde in said premix hardening agent ranges from 1:0.1 to 1:0.7.
Claim 4
Dependent Claim
30 words
The process of claims 1 or 2 wherein said premix hardening agent is added to said gelatin-containing solution in a quantity of 0.5 to 4% based upon the gelatin content.
Claim 5
Dependent Claim
31 words
The process of claims 1 or 2 wherein said gelatin-containing solution contains an additional hardener taken from the group consisting of chromium salts, dialdehyde compounds, aziridine compounds and vinyl sulfone derivatives.
Claim 6
Dependent Claim
17 words
The process of claims 1 or 2 wherein said gelatin-containing solution contains carbamide as a hardening accelerator.
References Cited (Backward Citations)
US4232111A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |