GB1143674A - - Google Patents

Abstract

1,143,674. Developing photographic silver halide materials. EASTMAN KODAK CO. May 6, 1966 [May 10, 1965], No. 20015/66. Heading G2C. An exposed photographic silver halide material is developed by a developing agent which is a bridged 5:8-dihydro- or 5:6:7: 8-tetrahydro-1:4- dihydroxynaphthalene, or a bridged 1:4:5:8-tetrahydro-, 1:4: 5: 6:7:8-hexahydro- or 1:2:3:4:5:6: 7: 8-octahydro- 9:10-dihydroxyanthracene, which preferably is of one of the formulae: - wherein R and R<SP>1</SP> are each hydrogen, alkyl, aryl, hydroxy, sulpho, halo, amino, alkylamino, substituted this or a heterocyclic group; R<SP>2</SP>, R<SP>3</SP>, R<SP>4</SP>, R<SP>5</SP>, R<SP>6</SP>, R<SP>7</SP>, R<SP>8</SP> and R<SP>9</SP> are each hydrogen, alkyl of 1-5 carbons or aryl and x and y are each oxygen or methylene or ethylene which may be substituted. The developing agent may be present in an alkaline developer solution, or may be present in the silver halide material in the emulsion or in a layer contiguous thereto when an auxiliary developing agent such as a p-amino-phenol or a 3-pyrazolidone may also be present. The developing agents also act as anti-foggants. The bridged 5: 8-dihydro- and 5: 6: 7:8-tetrahydro-1:4-dihydroxynaphthalenes having no substituent adjacent to a hydroxy group are tanning developers and may be used alone or together with non-tanning developers to form photoresists, for example by incorporation into an unhardened silver halide emulsion coated on a stripping film (see Example 1) or into such an emulsion coated on cellulose acetate film support (see Examples 2 and 4) and processed by development and washing-off. The developing agents may also be used in the silver salt diffusion transfer process and in colour transfer processes involving imagewise diffusion of a developer, colour coupler or dye.