The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 1990
Filed:
Jun. 30, 1988
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
This invention is a process of quickly forming high contrast negative images, which are useful for photomechanical process, by development-processing a silver halide photographic material containing a hydrazine derivative in at least one of silver halide emulsion layer(s) and other hydrophilic colloid layer(s) after imagewise exposure in the existence of a compound represented by general formula (A); ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 each represents an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, a cycloalkenyl group, or a heterocyclic ring residue, these groups may have a substituent; m represents an integer; L represents an m-valent organic group bonded to the P atom through a carbon atom; n represents an integer of 1 to 3; and X represents an n-valent anion; said X may be bonded to L; using a stable processing solution. Furthermore, the invention is a high contrast negative type silver halide photographic material containing the compound of the above-described general formula (A) in at least one of the silver halide emulsion layer(s) and other hydrophilic colloid layer(s) thereof.