US3976490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removable antiblocking top coat
Assignee: Polaroid Corp
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Filing: 1974-08-16
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Granted: 1976-08-24
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Expires: 1994-08-16
Abstract
Abstract The present invention is directed to diffusion transfer photographic products especially useful as film units in film packs or the like. Essentially the photographic products presented comprise a photosensitive element which after processing can provide a useable negative which is preferably produced concurrently with the formation of a positive image pattern.
Inventors
- 👤 William T. Macleish
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:44
CPC Classifications
G; G03; G03C; G03C8/00; G03C8/42; G03C8/52; Y; Y10; Y10S; Y10S430/00; Y10S430/151
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
81 words
A photosensitive element which comprises a photosensitive silver halide layer coated on a first surface of a pellucid plastomeric layer and, coated on a second surface of said plastomeric layer, an opaque plastomeric sheet material; said sheet material comprising a substantially water-insoluble, fluid swellable polymeric material adapted to lose adhesive capability upon swelling, thereby separating from said pellucid layer and a top coat comprising particulate material in a binder material, said binder material comprising a hydrophilic polymer and a hydrophobic polymer.
Claim 2
Dependent Claim
81 words
A photosensitive element which comprises a photosensitive silver halide layer coated on a first surface of a pellucid plastomeric layer and, coated on a second surface of said plastomeric layer, an opaque plastomeric sheet material; said sheet material comprising a substantially water-insoluble, fluid swellable polymeric material adapted to lose adhesive capability upon swelling, thereby separating from said pellucid layer and a top coat comprising particulate material in a binder material, said binder material comprising a hydrophilic polymer and a hydrophobic polymer.
Claim 3
Dependent Claim
21 words
A photosensitive element of claim 1 wherein said opaque plastomeric sheet material has an optical density of at least about 6.0.
Claim 4
Dependent Claim
25 words
The photosensitive element of claim 1 wherein the ratio of said hydrophilic polymer to said hydrophobic polymer is from 70:30 to 30:70 parts by weight.
Claim 5
Dependent Claim
11 words
The photosensitive element of claim 3 wherein said ratio is 1:1.
Claim 6
Dependent Claim
21 words
The photosensitive element of claim 1 wherein said particulate material is selected from the group consisting of synthetic and natural materials.
Claim 7
Dependent Claim
17 words
The photosensitive element of claim 5 wherein said particulate material has a particle size of 5-20 microns.
Claim 8
Dependent Claim
17 words
The photosensitive element of claim 6 wherein said particulate material has a particle size of 7-10 microns.
Claim 9
Dependent Claim
12 words
The photosensitive element of claim 5 wherein said particulate material is silica.
Claim 10
Dependent Claim
21 words
The photosensitive element of claim 1 wherein said hydrophilic polymer is polyvinyl pyrrolidone and said hydrophobic polymer is cellulose acetate butyrate.
Claim 11
Dependent Claim
36 words
The photosensitive element of claim 1 wherein said opaque plastomeric sheet material comprises a polymeric material chosen from the group consisting of polyvinyl alcohol, polyacrylamides, carboxyalkycelluloses and mixtures thereof and carbon black as the opacifying material.
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) | 1979-08-24 | 1980-02-23 | 1980-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-24 | 1984-02-23 | 1984-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-24 | 1988-02-23 | 1988-08-24 | $7700.00 | Window Closed / Lapsed |