GB1052446A - - Google Patents

Abstract

1,052,446. Silver salt diffusion transfer processes and developers. EASTMAN KODAK CO. Sept.13, 1963 [Sept.13, 1962], No.36246/63. Heading G2C. In the silver salt diffusion transfer process, the final image is formed in the presence of a compound of formula wherein R 1 and R 2 are hydrogen or alkyl, hydroxy- or amino-alkyl with 1 to 6 carton atoms or together complete a saturated 5-or-6 membered ring,. m is 1-3, n to 1-6, and 2 is hydrogen, hydrogen hydrochloride, or completes an isothio-uronium salt, a metal complex or a formaldehyde mercaptal. This compound may be added to the receiving sheet or to the developer and specified compounds are wherein R 1 and R 2 are hydrogen; methyl; ethyl, 2-hydroxyethyl; 1, 1 -dimethyl-2-hydroxyethyl; 1, 1-(dihydroxymethyl) ethyl; tris-(hydroxymethyl) methyl; 2-hydroxypropyl; 2-aminoethyl and 2, 3, 4, 5, 6-hectahydroxy hexyl or complete a piperidine or morpholine ring, m is 2 or 3 and z is hydrogen, zinc chloride or completes iso-thioronium chloride hydrochloride salt. The silver halide emulsion layer may be coated over the receptor layer containing precipitating nuclei, image-wise exposed and developed in the presence of the above compound and then the emulsion removed to leave a neutral black image in the receptor sheet. Alternatively, the receptor sheet may be contacted with the exposed emulsion and then processed to give a neutral image. One or more of the above compounds may be used or mixed with 3-mercapto-1, 2, 4 triazole, 1-methyl- 1, 2, 3, 6-tetrahydro-1, 3, 5-triazine-4-thiol or 3, 8-dithiadecane-1, 10-bis(N-methylpiperidinium-p-toluenesulphnate).