Color diffusion transfer photographic products and processes utilizing an image receiving element containing a polymeric acid layer

Claim 1

IN A PROCESS WHICH COMPRISES DEVELOPING AN EXPOSED PHOTOSENSITIVE ELEMENT CONTAINING A LAYER OF BLUESENSITIVE SILVER HALIDE EMULSION, A LAYER OF A GREEN-SENSITIVE SILVER HALIDE EMULSION, AND A LAYER OF RED-SENSITIVE SILVER HALIDE EMULSION, AND SILVER HALIDE EMULSIONS BEING SUPERPOSED ON THE SAME SUPPORT AND HAVING ASSOCIATED THEREWITH, RESPECTIVELY, A YELLOW DYE DEVELOPER, A MAGENTA DYE DEVELOPER, AND A CYAN DYE DEVELOPER, EACH OF SAID DYE DEVELOPERS CONTAINING A HYDRO QUINONYL RADICAL, SAID DEVELOPMENT BEING EFFECTED IN THE PRESENCE OF A SUBSTANTIALLY COLORLESS HYDROQUINONE, A QUATERNARY AMMONIUM COMPOUND AND AN ALKALI METAL HYDROXIDE, AND FORMING A TRANSFER IMAGE BY DIFFUSION TRANSFER OF UNOXIDIZED DYE DEVELOPERS TO A SUPERPOSED IMAGE-RECEIVING LAYER, THE IMPROVEMENT COMPRISING MAINTAINING THE PH AT ABOUT 13 TO 14 UNTIL SAID DEVELOPMENT AND SAID TRANSFER HAVE BEEN SUBSTANTIALLY COMPLETED, AND THEREAFTER, RAPIDLY REDUCING THE PH OF SAID TRANSFER IMAGE TO A LOWER LEVEL SUBSTANTIALLY PRECLUDING AERIAL OXIDATION OF THE HYDROQUINONYL DEVELOPING MOIETY OF SAID DYE DEVELOPERS UPON SEPARATING AND EXPOSING SAID TRANSFER IMAGE TO AIR, SAID PH REDUCTION BEING EFFECTED BY DIFFUSING ALKALI AND OTHER SALT-FORMING REAGENTS FROM THE LAYER CONTAINING SAID TRANSFER IMAGE TO AN ADJACENT LAYER CONTAINING A POLYMERIC ACID CAPABLE OF FORMING SALTS WITH ALKALI METALS, SAID ADJACENT LAYER BEING POSITIONED ON THE SIDE OF SAID IMAGE-RECEIVING MOST DISTANT FROM THE SILVER HALIDE EMULSIONS OF SAID PHOTOSENSITIVE ELEMENT.