US4029849A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cover sheets with timing layer comprising cellulose acetate and copolymer of maleic anhydride
Assignee: Eastman Kodak Co
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Filing: 1976-09-07
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Granted: 1977-06-14
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Expires: 1996-09-07
Abstract
Abstract Timing layer for color diffusion transfer assemblages comprises a mixture of cellulose acetate and a maleic anhydride copolymer with 2 to 20% by weight of the mixture being said copolymer.
Inventors
- 👤 Edward P. Abel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:50
CPC Classifications
G; G03; G03C; G03C8/00; G03C8/42; G03C8/52; G03C8/54; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/3188; Y10T428/31884; Y10T428/31891; Y10T428/31909; Y10T428/31928; Y10T428/31971; Y10T428/31975; Y10T428/31978
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
56 words
In a cover sheet comprising a transparent support having thereon in order a neutralizing layer and a timing layer, the improvement comprising employing as said timing layer a compatible mixture of cellulose acetate and a maleic anhydride copolymer to provide a clear layer, said mixture comprising about 2 to about 20% by weight of said copolymer.
Claim 2
Dependent Claim
56 words
In a cover sheet comprising a transparent support having thereon in order a neutralizing layer and a timing layer, the improvement comprising employing as said timing layer a compatible mixture of cellulose acetate and a maleic anhydride copolymer to provide a clear layer, said mixture comprising about 2 to about 20% by weight of said copolymer.
Claim 3
Dependent Claim
12 words
The cover sheet of claim 1 wherein said copolymer comprises poly(styrene-co-maleic anhydride).
Claim 4
Dependent Claim
20 words
The cover sheet of claim 2 wherein said mixture comprises about 5 to about 10% by weight of said copolymer.
Claim 5
Dependent Claim
12 words
The cover sheet of claim 1 wherein said copolymer comprises poly(ethylene-co-maleic anhydride).
Claim 6
Dependent Claim
20 words
The cover sheet of claim 4 wherein said mixture comprises about 5 to about 10% by weight of said copolymer.
Claim 7
Dependent Claim
14 words
The cover sheet of claim 1 wherein said copolymer comprises poly(methyl vinyl ether-co-maleic anhydride).
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) | 1980-06-13 | 1980-12-13 | 1981-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-13 | 1984-12-13 | 1985-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-13 | 1988-12-13 | 1989-06-14 | $7700.00 | Window Closed / Lapsed |