US 5,447,821 AGranted

Reducer and reduction method for silver images

AssigneeFuji Photo Film Co., Ltd.

InventorsHisashi Okada, Morio Yagihara, Katsumi Hayashi

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Abstract

A reducer containing a ferric chelate compound of an amino compound and further containing an reduction accelerator and/or a complex-forming agent and a dye. ##STR1## wherein A.sub.41, A.sub.42 and A.sub.43 each individually represents a carboxyl group, a phosphono group, a sulfo group or a hydroxyl group; L.sub.41 and L.sub.42 each individually represents a divalent coupling group containing an aliphatic group, an aromatic group, a heterocyclic group or combinations thereof; R.sub.41 represents a substituent; and a represents 0, 1, 2, 3 or 4. The reducer is superior in the rate of reduction, reducibility and reduction working properties and so stable that no precipitate will separate out with time. Also disclosed is a silver image reducing method wherein a silver image formed by exposing and developing a silver halide photosensitive material is reduced in the presence of the above-described reducer. The reducer and the reducing method are suitable for application to high-contrast photosensitive materials.

Claims7

Dependent claims

A reducer, comprising:

a ferric chelate compound of at least one amino compound represented by the formula:
##STR33## wherein A.sub.41, A.sub.42 and A.sub.43 each individually represents a carboxyl group, a phosphono group, a sulfo group or a hydroxyl group;
L.sub.41 and L.sub.42 each individually represent a divalent coupling group containing an aliphatic group, an aromatic group, a heterocyclic group or combinations thereof;
R.sub.41 represents a substituent;
and a represents 0, 1, 2, 3 or 4;
and
a reduction accelerator represented by the formula:
A.sup.1 -(B.sup.1).sub.h -A.sup.2 (Z.sup.1).sub.i
wherein A.sup.1 and A.sup.2 each represents ##STR34## or a saturated or unsaturated heterocyclic residue containing at least one nitrogen. atom;
A.sup.1 and A.sup.2 may be the same or different;
R.sup.1, R.sup.2 and R.sup.3 each represents a hydrogen atom or an alkyl group;
R.sup.1, R.sup.2 and R.sup.3 may be the same or different;
q is 0 or 1;
a nitrogen atom in the heterocyclic residue may be in the form of a quaternary ammonium salt, and the heterocyclic residue may contain an oxygen atom or a sulfur atom;
B.sup.1 represents a divalent organic group comprising alkylene, alkenylene, arylene, --SO.sub.2 --, --SO--, --S--, --O--, ##STR35## (R.sup.4 represents hydrogen atom, an alkyl group, or an aryl group) alone or in combination;
h is 0 or 1;
Z.sup.1 represents an anion;
and i is 0, 1 or 2.

15 more elements

Dependencies are inferred from the claim text.