.beta.-Eliminating polymers for diffusion control in photographic products

A photosensitive element for use in diffusion transfer photographic processes comprising:

• a support layer;
• a negative component comprising at least one photosensitive silver halide emulsion layer having associated therewith a diffusion transfer process image-providing material;
• and
• at least one diffusion control layer comprising a polymer of the formula ##STR36## wherein R is hydrogen, halogen or lower alkyl;
• R.sup.1 is alkylene;
• and Z is an organic moiety capable under alkaline conditions of undergoing a .beta.-elimination reaction, said moiety containing at least two interbonded carbon atoms, one of the carbon atoms containing an acid-labile proton capable of abstraction under said alkaline conditions and an activating group effective to activate said .beta.-elimination reaction.

An image-receiving element comprising:

• a support layer;
• a neutralizing layer;
• a diffusion control layer comprising a polymer comprising recurring units of the formula ##STR43## wherein R is hydrogen, halogen or lower alkyl;
• R.sup.1 is alkylene;
• and Z is an organic moiety capable under alkaline conditions of undergoing a .beta.-elimination reaction, said moiety containing at least two interbonded carbon atoms, one of the carbon atoms containing an acid-labile proton capable of abstraction under said alkaline conditions and an activating group effective to activate said .beta.-elimination reaction, and an image-receiving layer.

An integral negative-positive diffusion transfer film unit comprising:

• a photosensitive laminate comprising a composite structure containing, in sequence, an opaque support layer, a negative component comprising at least one photosensitive silver halide emulsion layer having associated therewith an image dye-providing material, a positive component comprising an image-receiving layer dyeable by the image dye-providing material, and a transparent support layer, the photosensitive laminate also comprising a diffusion control layer containing a polymer comprising recurring units of the formula ##STR50## wherein R is hydrogen, halogen or lower alkyl;
• R.sup.1 is alkylene;
• and Z is an organic moiety capable under alkaline conditions of undergoing a .beta.-elimination reaction, said moiety containing at least two interbonded carbon atoms, one of the carbon atoms containing an acid-labile proton capable of abstraction under said alkaline conditions and an activating group effective to activate said .beta.-elimination reaction;
• means retaining an aqueous alkaline processing composition integrated with the film unit so that the processing composition can be distributed between the negative and positive components.

An integral negative-positive film unit comprising:

• a photosensitive laminate comprising, in sequence, a transparent support layer, a positive component comprising an image-receiving layer, a processing composition permeable, light-reflecting layer against which a dye image formed in said image-receiving layer can be viewed, and a negative component comprising at least one photosensitive silver halide emulsion layer having associated therewith an image dye-providing material;
• a transparent sheet superposed substantially coextensive the photosensitive laminate opposite the transparent layer;
• means retaining an aqueous alkaline processing composition, which includes an opacifying agent, integrated with the film unit such that the processing composition can be distributed between the photosensitive laminate and the transparent sheet;
• and
• a diffusion control layer comprising a polymer comprising recurring units of the formula ##STR51## wherein R is hydrogen, halogen or lower alkyl;
• R.sup.1 is alkylene;
• and Z is an organic moiety capable under alkaline conditions of undergoing a .beta.-elimination reaction, said moiety containing at least two interbonded carbon atoms, one of the carbon atoms containing an acid-labile proton capable of abstraction under said alkaline conditions and an activating group effective to activate said .beta.-elimination reaction;
• said diffusion control layer being contained within said film unit as either a component of said photosensitive laminate or a coating on that side of said transparent sheet contiguous the photosensitive laminate.