Patent US4357418A successfully refreshed from Google Patents.
US4357418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic elements with improved surface characteristics
Assignee: 3M Co
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Filing: 1981-05-26
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Granted: 1982-11-02
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Expires: 2001-05-26
Abstract
Abstract It is generally undesirable to have surfaces on photographic elements which are highly reflective and therefore reduce the attractiveness of the image. One of the traditional means of correcting this reflectance is to coat the developed film or print with an anti-reflective coating or to place a glass cover over the imaged photographic element where the glass itself has an anti-reflective surface. According to the present invention, an anti-reflective surface may be provided within the photographic element itself by including within a top coat gelatin layer a water-soluble dextran incompatible with gelatin.
Inventors
- 👤 Luigi Cellone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:56
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/76; G03C1/7614; G03C1/95; G03C1/005; G03C1/06; G03C1/32; G03C2200/00; G03C2200/42; G03C2200/50; Y; Y10; Y10S; Y10S430/00; Y10S430/151; Y10S430/162
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
53 words
A photographic element comprising a support and a plurality of gelatine layers which comprise a silver halide emulsion layer and a non-photosensitive external gelatin protective layer, wherein said external gelatin protective layer comprises a reflectance reducing quantity of water-soluble dextran having a molecular weight of at least 100,000 which is incompatible with gelatin.
Claim 2
Dependent Claim
53 words
A photographic element comprising a support and a plurality of gelatine layers which comprise a silver halide emulsion layer and a non-photosensitive external gelatin protective layer, wherein said external gelatin protective layer comprises a reflectance reducing quantity of water-soluble dextran having a molecular weight of at least 100,000 which is incompatible with gelatin.
Claim 3
Dependent Claim
33 words
A photographic element as claimed in claim 1, wherein said protective layer has a thickness between about 0.5 and about 2.0 microns and said dextran has a molecular weight between 100,000 and 900,000.
Claim 4
Dependent Claim
23 words
A photographic element as claimed in claim 2, wherein said dextran incompatible with gelatin is mixed with a water-soluble dextran compatible with gelatin.
Claim 5
Dependent Claim
24 words
A photographic element as claimed in claim 2, wherein said dextran incompatible with gelatin has an average molecular weight of between 300,000 and 900,000.
Claim 6
Dependent Claim
24 words
A photographic element as claimed in claim 3, wherein said dextran incompatible with gelatin has an average molecular weight of between 300,000 and 900,000.
Claim 7
Dependent Claim
49 words
A photographic element as claimed in claim 4 or 5, wherein said dextran incompatible with gelatin is present in the proportion of between about 10% and about 90% with respect to the gelatin of the protective layer and the average molecular weight of the dextran is at least 200,000.
Claim 8
Dependent Claim
61 words
A photographic element as claimed in claim 4 or 5, wherein said dextran incompatible with gelatin is present in the proportion of between about 10% and about 90% with respect to the gelatin of the protective layer and is included in the protective layer in the presence of agents with increase the covering power of the silver in said emulsion layer.
Claim 9
Independent Claim
93 words
A method for making the surface of a photographic element non-bright, wherein the element comprises a support and a plurality of gelatin layers which comprise at least one silver halide emulsion layer and a non-photosensitive external protective layer, consisting of mixing a gelatin coating composition for the external protective layer with an aqueous solution of a dextran having a molecular weight of at least 100,000 which is incompatible with dry gelatin before being spread over said at least one emulsion layer, then spreading the resulting composition over said at least one emulsion layer.
Claim 10
Independent Claim
93 words
A method for making the surface of a photographic element non-bright, wherein the element comprises a support and a plurality of gelatin layers which comprise at least one silver halide emulsion layer and a non-photosensitive external protective layer, consisting of mixing a gelatin coating composition for the external protective layer with an aqueous solution of a dextran having a molecular weight of at least 100,000 which is incompatible with dry gelatin before being spread over said at least one emulsion layer, then spreading the resulting composition over said at least one emulsion layer.
References Cited (Backward Citations)
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-01 | 1986-05-03 | 1986-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-01 | 1990-05-03 | 1990-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-01 | 1994-05-03 | 1994-11-02 | $7700.00 | Window Closed / Lapsed |