PURPOSE: To reduce fog and to elevate sensitivity by incorporating substantial silver chlorobromide grains sulfur-sensitized in th presence of a silver halide solvent in one of silver halide emulsion layers, and hardening silver halide emulsion layers with a hardening agent represented by formula I or II.
CONSTITUTION: A silver halide emulsion layer is sulfur sensitized in the presence of a silver halide solvent, and a sulfur sensitizer used here is a compd. reacting with silver halide and finally forming AgS, such as sodium thiosulfate or other thiosulfates, and it is used in an amt. of 10-4W10-8mol per mol of silver halide, changed depending on the kinds of the sensitizers. The hardening agent is represented by formula I or II, and it is added to the emulsion layers as well as one or more other other nonphotosensitive layer. These hardening agents are used alone or in a mixture of 2 or more, in an amt. of 1W100mg per 1g of gelatin, preferably, 5W50mg per 1g of gelatin. In formula I, R1 is Cl, hydroxy, alkyl, alkoxy, alkylthio, -OM, -NR'R" or -NHCOR'''; M is a univalent metal atom; R', R" are each H, alkyl, or aryl; R''' is same as R'; and R2 is same as R1 except Cl. In formulaII, each of R3 and R4 is Cl, hydroxy, alkyl, alkoxy, or -OM'; M' is same as M; each of Q, Q' is a bonding group of -O-, -S-, or -NH-; L is alkylene or arylene; and each of p, q is 0 or 1.
ONODERA KAORU
MIYOSHI MASANOBU
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