Konishiroku Photo Industry Co., Ltd.

Noboru Itoh

Toshiaki Takahashi

Keiji Ogi

Atsushi Kamitakahara

Disclosed is a method for preparing a light-sensitive cuprous halide emulsion which comprises reducing cupric ions by an ascorbic acid derivative represented by the general formula: ##STR1## wherein R is a hydrogen atom or a hydroxyl group, and n is an integer of 1 to 4, provided that R is a hydroxyl group when n is 1, or its alkali metal salt, in the presence of halogen ions.

Method for preparing a light-sensitive cuprous halide emulsion

An image-forming method wherein a photosensitive material comprising a support having a photosensitive copper (I) halide emulsion that contains silver halide and which has grains of copper (I) halide crystal dispersed in a binder is subjected to imagewise exposure and development with an alkaline solution is disclosed. The imagewise exposure is effected either in a dry or wet state. The alkaline solution contains compounds selected from at least two of the following three groups: (A) a group consisting of .alpha.-amino acids, .alpha.-amino acid derivatives, aliphatic carboxylic acids, oxycarboxylic acids, ketocarboxylic acids, aromatic carboxylic acids, amines, amine derivatives, aminocarboxylic acids, quinoline derivatives and pyridine derivatives, which compounds have a stability constant for Cu(II) complex between 5 and 15; (B) a group consisting of 4-aminophenols and 3-pyrazolidones; and (C) a group consisting of ascorbic acid derivatives of the following formula (I) and alkali metal salts thereof: ##STR1## wherein R is a hydrogen atom or a hydroxyl group; n is a positive integer of from 1 to 4, and when n=1, R represents only a hydroxyl group. The result is an image of improved quality that has a high maximum color density, low fog density, high contrast and a neutral tone.

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Hino, Japan

Noboru Itoh