Reference

Negative silver halide emulsions protected against desensitization by pressure

Negative silver halide emulsions protected against desensitization by pressure. (Kodak-Pathe, Fr.). Fr. Demande FR 2296204 23 Jul 1976, 10 pp. (French). (France). CODEN: FRXXBL. CLASS: IC: G03C001-08. APPLICATION: FR 74-42941 27 Dec 1974. DOCUMENT TYPE: Patent CA Section: 74 (Radiation Chemistry, Photochemistry, and Photographic Processes) Section cross-reference(s): 71 Desensitization of a Ag halide emulsion, sensitized by S and/or Se and by Au, due to pressure is minimized if during the pptn. of the Ag halides 10-6-10-10 mol of an Ir or Rh salt, preferably <10-8 mol of an NH4 or alkali metal chloroiridite or chloroiridate, and 1-500 mg of water-sol. adenine sulfate per mol Ag are present. Thus, prior to pptg. the AgBr of a radiographic emulsion contg. 1.75% AgI, 0.00215 mg of K chloroiridite and 17.4 g adenine sulfate per mol Ag were added to the KBr soln. 321-30-2 and 16920-56-2 which are cas registry numbers of substances are two of reagents here. Besides lowering desensitization by abrasion or bending, the reciprocity failure of the emulsion for a 50-s exposure was reduced from logE 0.23 to 0.07, practically without effect on speed and fog. .

Silver halide photographic material

Silver halide photographic material. Noda, Toru; Ueda, Bunzo (Mitsubishi Paper Mills, Ltd., Japan). Japan. Kokai JP 51107129 22 Sep 1976 Showa, 17 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: IC: G03C001-34. APPLICATION: JP 75-32680 18 Mar 1975. DOCUMENT TYPE: Patent CA Section: 74 (Radiation Chemistry, Photochemistry, and Photographic Processes) Ag halide photog. materials are obtained by adding during the formation, dispersion, or phys. ripening of the Ag halide, .gtoreq.1 mercaptosubstituted heterocyclic compd. 10-6-10-3 and .gtoreq.1 water-sol. Ir compd. 10-7-10-5 mol/mol Ag halide. These materials have good tone reproduction (esp. high contrast), good spectral sensitivity, show small tendency for stress fogging, and possess good shelf life. Thus, a Ag(Br,Cl) emulsion prepd. using K2IrCl6, a 0.1% MeOH soln. of 4-benzamido-5-phenyl-1,2,4-triazole-3-thiol, a 1% MeOH soln. of 2-benzimidazolethiol, 5-hydroxy-7-propyl-s-triazol[1,5-a]pyrimidine, a red-sensitizing dye, and a cyan coupler, upon coating and heating for 2 days at 35.degree. 16920-56-2 and 32476-07-6 are also in the experiment. and then processing showed a relative sensitivity of 34.5, a relative exposure tolerance of 0.35, a relative exposure tolerance after storage for 9 months of 0.37 (all towards red light), a relative sensitivity of 27.8 towards blue light, background d. of 0.03, and was free of stress fogging. A control emulsion prepd. without the Ir compd. had comparable photog. properties but showed extensive stress fogging. .