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. 30, 1995
Filed:
Aug. 10, 1993
Munehisa Fujita, Kanagawa, JP;
Toru Sano, Kanagawa, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
An internal latent image type positive silver halide emulsion has improved sensitivity reduction in low illuminance exposures. A color diffusion transfer light-sensitive material incorporates the emulsion and has reduced sensitivity reduction. The internal latent image type positive silver halide emulsion is prepared using a polymer having a repetitive unit derived from an ethylenically unsaturated monomer having at least one thioether structure on a side chain as a deflocculating agent to form silver halide grains and subjecting the grain surfaces to a chemical sensitization in the presence of a polymer having a repetitive unit represented by the following Formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom or a substituted or unsubstituted alkyl group and Q represents a group selected from the group consisting of groups represented by the following Formula (1) to Formula (4): ##STR2## wherein q represents an integer of 2 to 4; ##STR3## wherein R.sup.2 and R.sup.3 each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group; ##STR4## wherein Z.sup.1 represents a group of atoms necessary to form a substituted or unsubstituted lactam ring, a substituted or unsubstituted oxazolidone ring, or a substituted or unsubstituted pyridone ring; and A represents a single bond, a --C(.dbd.O)-- group, or a group represented by the following Formula (3a): ##STR5## wherein B represents an --O-- group or an --N(R.sup.4)-- group, in which R.sup.4 represents a hydrogen atom or a substituted or unsubstituted alkyl group; and k represents an integer of 1 to 6; ##STR6## wherein A has the same meaning as A in the above Formula (3); D represents a single bond, an --O-- group or an --N(R.sup.5)-- group; m and n each represents an integer of 1 to 6, which satisfy the relationship of m+n.dbd.4 to 7, in which R.sup.5 represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a group represented by the following Formula (4a): ##STR7## wherein R.sup.6 represents a substituted or unsubstituted alkyl group.