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US 5,593,810 AGranted
Diffusion transfer film unit
AssigneePolaroid Corporation
InventorsEdward P. Lindholm, James J. Manning
Life of this patent
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Abstract
There is described a novel diffusion transfer film unit for use in a diffusion transfer photographic system which includes a layer comprising a polyester urethane polymer(s) which is inert to alkali, and specifically, a layer which exhibits permeability to alkali inversely dependent upon temperature. Diffusion transfer photographic systems utilizing the diffusion transfer film unit of the present invention exhibit superior hot temperature processing.
Claims22
A diffusion transfer photographic film unit which comprises:
- a support;
- a polymeric acid-reacting layer;
- at least one silver halide emulsion layer;
- an image-receiving layer;
- and
- a layer exhibiting temperature inverting properties and comprising from about 15% to about 50% by weight of a polyester urethane polymer which is inert to alkali and from about 50% to about 85% by weight of a second polymeric material.
3 more elements
A diffusion transfer photographic film unit comprising:
- a photosensitive element comprising a support carrying at least one silver halide emulsion layer in association with an image dye-providing material;
- an image-receiving element comprising a support carrying a polymeric acid-reacting layer, a timing layer residing on said polymeric acid-reacting layer, said timing layer exhibiting temperature inverting properties and comprising from about 15% to about 50% by weight of a polyester urethane polymer which is inert to alkali and from about 50% to about 85% by weight of a second polymeric material, said image-receiving element superposed or superposable on said photosensitive element;
- an image-receiving layer;
- and
- means providing an aqueous alkaline processing composition for initiating development of said silver halide emulsion after photoexposure to form an image on said image-receiving layer.
2 more elements
Dependencies are inferred from the claim text.