US3791831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic materials with antistatic layers
Assignee: Agfa Gevaert AG
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Filing: 1971-03-03
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Granted: 1974-02-12
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Expires: 1991-03-03
Abstract
Abstract The antistatic properties of photographic materials can be improved by applying an antistatic layer containing as antistatic agents a mixture of polymers, or a graft polymer, containing sulfo as well as carboxyl groups.
Inventors
- 👤 Bonin W Von
- 👤 J Geiger
- 👤 W Himmelmann
- 👤 G Meinhardt
- 👤 W Wagenknecht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:34
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/76; G03C1/85; G03C1/89
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
27 words
The photographic material of claim 1, wherein the polymer containing sulfo groups is a polystyrene sulfonic acid containing between 15 and 75 percent by weight sulfo groups.
Claim 2
Dependent Claim
27 words
The photographic material of claim 1 wherein the polymer containing sulfo groups is a copolymer containing at least 40 percent by weight of units of sulfosubstituted N-phenylmaleicimides.
Claim 3
Dependent Claim
13 words
The photographic material of claim 1, wherein the antistatic layer also contains gelatine.
Claim 4
Dependent Claim
28 words
The photographic material of claim 1 wherein the polymer containing sulfo groups is a copolymer selected from the group consisting of ethylene and isobutylene and sulfosubstituted N-phenylmaleicimide units.
Claim 5
Dependent Claim
18 words
The photographic material of claim 1, wherein the polymer containing carboxyl groups is polymethacrylic acid or polyacrylic acid.
Claim 6
Dependent Claim
23 words
The photographic material of claim 1, wherein the polymer containing sulfo groups is a copolymer consisting essentially of styrene and N-4-sulfophenylmaleic imide units.
Claim 7
Dependent Claim
12 words
The photographic material of claim 1, wherein the polymers are grafted together.
Claim 8
Dependent Claim
24 words
The photographic material of claim 8, wherein the graft is the result of polymerizing the carboxylsubstituTed monomers in the presence of the sulfosubstituted polymer.
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |