Diffusion control layers for diffusion transfer photographic film
AssigneePolaroid Corporation
InventorsWilliam C. Schwarzel, Lloyd D. Taylor
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Abstract
A diffusion control layer for a diffusion transfer photographic film unit comprising a urethane polymer including recurring backbone units capable of undergoing .beta.-elimination degradation in an alkaline environment.
Claims31
A diffusion transfer photographic film unit comprising:
- a photosensitive element including at least one photosensitized silver halide emulsion layer having an image-dye forming material associated therewith;
- an image-receiving layer;
- a means for introducing an alkaline processing composition within said film unit;
- a neutralizing layer;
- and,
- at least one diffusion control layer positioned between interacting components of said film unit;
- said diffusion control layer comprising a urethane polymer containing a recurrent backbone unit capable of undergoing .beta.-elimination depolymerization in an alkaline environment.
A photosensitive element for use in a diffusion transfer photographic process which comprises:
- at least two selectively sensitized silver halide layers having image-dye forming materials associated therewith:
- and
- an interlayer separating said silver halide layers;
- said interlayer comprising a urethane polymer containing a recurrent backbone unit capable of undergoing .beta.-elimination depolymerization in an alkaline environment.
A photographic element, for use in a diffusion transfer photographic process, including a neutralizing system for lowering the pH of an aqueous alkaline processing fluid, said neutralizing system containing a neutralizing layer and a time modulating layer so disposed with respect to the neutralizing layer that said alkaline processing fluid must first diffuse through the time modulating layer before contacting said neutralizing layer, said time modulating layer comprising a urethane polymer containing a recurrent backbone unit capable of undergoing .beta.-elimination depolymerization in an alkaline environment.
Dependencies are inferred from the claim text.