| 摘要 |
1,161,346. Photographic silver halide developer. PAKO CORP. Oct.18, 1966 [Oct. 20, 1965], No.46606/66. Heading G2C. High contrast photographic silver halide developers contain a p-dihydroxybenzene silver halide developing agent and ascorbic acid or an alkali-metal salt or derivative thereof, but not more than 5 g. per litre of a dissociated sulphite, such as sodium sulphite or bisulphite or potassium metabisulphite, and less than 0À05 g. per litre of an aromatic amino silver halide developing agent. The developer may contain formaldehyde bisulphite compounds and may be prepared in dry powder or concentrate form for the preparation of working developer by the addition of solvent. |
