US3632374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making photographic elements
Assignee: Eastman Kodak Co
•
Filing: 1968-06-03
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Granted: 1972-01-04
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Expires: 1988-06-03
Abstract
Abstract In the manufacture of photographic elements, such as photographic film or paper, the support is coated by forming a free-falling vertical curtain of liquid photographic coating composition in such manner that the curtain is stable and has a uniform flow rate across its width and directing the support so that the free-falling curtain impinges thereon, while maintaining a controlled relation between the flow rate and the speed at which the support is moved, to form a thin layer of the coating composition on the face of the support. Apparatus which is particularly advantageous for carrying out this method includes means for advancing the support at the desired speed and a hopper for the coating composition which is provided with a downwardly inclined slide surface down which the coating composition flows by gravity, the slide surface terminating in a lip spaced vertically above the moving support from which the coating composition flows as a free-falling curtain.
Inventors
- 👤 Jack Francis Greiller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:18
CPC Classifications
B; B05; B05C; B05C5/00; B05C5/007; B05C5/008; B05C5/005; G; G03; G03C; G03C1/00; G03C1/74; B05C9/00; B05C9/06; G03C2001/7433; G03C2001/7462; G03C2001/7466; G03C2001/747; G03C2001/7477; G03C2001/7481; G03C2001/7492; Y; Y10; Y10S; Y10S430/00; Y10S430/136
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
18 words
The method as described in claim 1 wherein the moving support is in the form of discrete sheets.
Claim 2
Dependent Claim
33 words
directing a liquid photographic coating composition through a narrow elongated metering slot which opens onto a downwardly inclined supporting surface to form a thin layer of said coating composition of substantially uniform thickness;
Claim 3
Dependent Claim
42 words
flowing the layer down said supporting surface so that the liquid in said layer is gravitationally accelerated at less than acceleration in free fall and is distributed by the action of gravity to provide exact thickness uniformity across the flowing layer; and
Claim 4
Dependent Claim
15 words
The method as described in claim 1 wherein the moving support is a continuous web.
Claim 5
Dependent Claim
30 words
The method as described in claim 1 wherein a surfactant is incorporated in the coating composition to reduce its surface tension and increase the stability of the free-falling vertical curtain.
Claim 6
Dependent Claim
105 words
forming from the flowing layer within said coating zone a free-falling vertical curtain of said coating composition which extends transversely of said path and impinges on the face of said moving support forming thereon a layer of said coating composition; said curtain having a uniform flow rate over substantially all of such portion of its width as is coextensive with said support, the flow rate of the coating composition being at least about 0.5 cubic centimeter per second per centimeter of curtain width, and the ratio of said flow rate to the velocity of said support in centimeters per second being less than about 0.015.
Claim 7
Dependent Claim
24 words
The method as described in claim 1 wherein the height of the free-falling vertical curtain is from about 5 centimeters to about 20 centimeters.
Claim 8
Dependent Claim
29 words
The method as described in claim 1 wherein the downward velocity of coating composition along the line where free fall commences is less than about 20 centimeters per second.
Claim 9
Dependent Claim
29 words
The method as described in claim 1 wherein the downward velocity of coating composition along the line where free fall commences is less than about 10 centimeters per second.
Claim 10
Dependent Claim
36 words
The method as described in claim 1 further comprising the step of reducing the thickness of the boundary layer of air on the face of the moving support immediately before the free-falling vertical curtain impinges thereon.
Claim 11
Dependent Claim
33 words
The method as described in claim 1 further comprising the step of guiding the vertical free-falling curtain along its longitudinal edges to define its width at impingement onto the face of the support.
Claim 12
Dependent Claim
25 words
The method as described in claim 1 further comprising the step of wetting the face of the support before the free-falling vertical curtain impinges thereon.
Claim 13
Dependent Claim
21 words
The method as described in claim 1 wherein the moving support is rigidly supported as it passes through the coating zone.
Claim 14
Dependent Claim
16 words
The method as described in claim 1 wherein the coating composition is a silver halide/gelatin emulsion.
Claim 15
Dependent Claim
14 words
The method as described in claim 1 wherein the support is photographic film base.
Claim 16
Dependent Claim
13 words
The method as described in claim 1 wherein the support is photographic paper.
References Cited (Backward Citations)
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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) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |