US4359518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stripping sheet for use with diffusion transfer film unit
Assignee: Polaroid Corp
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Filing: 1981-06-26
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Granted: 1982-11-16
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Expires: 2001-06-26
Abstract
Abstract A stripping sheet adapted for use with a diffusion transfer film unit to remove at least the photosensitive layer from said film unit subsequent to processing is disclosed, as well as methods for using said stripping sheet, wherein said stripping sheet comprises a support, carrying in order, a water-absorbing layer, and a layer capable of conversion from substantial liquid processing composition impermeability to a condition of substantial liquid processing composition permeability.
Inventors
- 👤 Raymond B. Hanselman
- 👤 Karl J. Schreiber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:36
CPC Classifications
G; G03; G03C; G03C8/00; G03C8/42; G03C8/52
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
162 words
A method which comprises the steps (a) exposing a diffusion transfer film unit comprising a support carrying, in order, an image-receiving layer, and a photosensitive silver halide emulsion layer; (b) disposing a liquid processing composition intermediate a stripping sheet and the outermost layer of said film unit distal to the support; (c) contacting said outermost layer of said film unit distal to the support with said stripping sheet wherein said stripping sheet comprises a support carrying, in order, a water-absorbing layer and a timing layer capable of conversion from substantial liquid processing composition impermeability to a condition of substantial liquid processing composition permeability; whereby said timing layer converts from said substantial liquid processing composition impermeability to said substantial liquid processing composition permeability thereby forming a bond between said outermost layer and said stripping sheet; and (d) detaching said stripping sheet and at least the photosensitive layer of the film unit adhered to said stripping sheet from the rest of the film unit.
Claim 2
Independent Claim
162 words
A method which comprises the steps (a) exposing a diffusion transfer film unit comprising a support carrying, in order, an image-receiving layer, and a photosensitive silver halide emulsion layer; (b) disposing a liquid processing composition intermediate a stripping sheet and the outermost layer of said film unit distal to the support; (c) contacting said outermost layer of said film unit distal to the support with said stripping sheet wherein said stripping sheet comprises a support carrying, in order, a water-absorbing layer and a timing layer capable of conversion from substantial liquid processing composition impermeability to a condition of substantial liquid processing composition permeability; whereby said timing layer converts from said substantial liquid processing composition impermeability to said substantial liquid processing composition permeability thereby forming a bond between said outermost layer and said stripping sheet; and (d) detaching said stripping sheet and at least the photosensitive layer of the film unit adhered to said stripping sheet from the rest of the film unit.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein said image-receiving layer is a dye image-receiving layer.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein said image-receiving layer contains silver precipitating nuclei.
Claim 5
Dependent Claim
23 words
The method of claim 1 wherein said film unit includes a protective layer intermediate said image-receiving layer and said photosensitive silver halide layer.
Claim 6
Dependent Claim
17 words
The process of claim 1 wherein said film unit includes a top coat containing an antihalation material.
Claim 7
Dependent Claim
11 words
The process of claim 5 wherein said top coat contains gelatin.
Claim 8
Dependent Claim
23 words
The process of claim 1 wherein said film unit includes a release layer intermediate said protective layer and said silver halide emulsion layer.
Claim 9
Dependent Claim
16 words
The process of claim 1 wherein said liquid processing composition includes a viscosity increasing polymeric material.
Claim 10
Dependent Claim
11 words
The process of claim 1 wherein said water-absorbing layer comprises gelatin.
Claim 11
Dependent Claim
15 words
The process of claim 1 wherein said timing layer comprises gelatin and a carboxylated polyacrylate.
Claim 12
Dependent Claim
19 words
The process of claim 1 wherein said water-absorbing layer ranges from about 250 to 3000 mg/ft 2 of gelatin.
Claim 13
Dependent Claim
19 words
The process of claim 11 wherein said gelatin is present at a level of about 1000 mg/ft 2 .
Claim 14
Dependent Claim
23 words
The process of claim 11 wherein said water-absorbing layer includes about 3 to 15% of zinc acetate based on the weight of gelatin.
Claim 15
Dependent Claim
25 words
The process of claim 13 wherein said zinc acetate is present at a level of about 10% based on the weight of said gelatin layer.
Claim 16
Dependent Claim
12 words
The process of claim 10 wherein said timing layer includes zinc acetate.
Claim 17
Dependent Claim
25 words
The process of claim 15 wherein said zinc acetate is present at a level of about 10-50% based on the weight of the carboxylated polyacrylate.
Claim 18
Dependent Claim
14 words
The process of claim 1 wherein said timing layer consists essentially of carboxylated polyacrylate.
Claim 19
Dependent Claim
12 words
The process of claim 1 wherein said timing layer comprises cross-linked gelatin.
Claim 20
Dependent Claim
20 words
The process of claim 1 wherein said timing layer includes particulate matter at least about 2μ in average diameter therein.
Claim 21
Dependent Claim
12 words
The process of claim 19 wherein said particulate matter comprises silica particles.
Claim 22
Dependent Claim
24 words
The process of claim 1 wherein said stripping sheet and at least said photosensitive layer are detached subsequent to substantial positive silver image formation.
Claim 23
Dependent Claim
17 words
The process of claim 1 wherein said film unit is an additive color diffusion transfer film unit.
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) | 1985-11-15 | 1986-05-17 | 1986-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-15 | 1990-05-17 | 1990-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-15 | 1994-05-17 | 1994-11-16 | $7700.00 | Window Closed / Lapsed |