GB1247654A - Light sensitive supersensitised silver halide photographic emulsion - Google Patents

Abstract

1,247,654. Light-sensitive supersensitized silver halide photographic emulsion. KONISHIROKU PHOTO INDUSTRY CO Ltd. March 13, 1970 [March 14, 1969j, No. 12345/70. Heading G2C. A light-sensitive silver halide photographic emulsion comprises at least one spectral sensitizing dye of the formula: wherein R 1 is an alkyl group having 1 to 4 carbons, R 2 is a sulphoalkyl or a carboxyalkyl group having 1 to 4 carbons in the alkyl portion, or an alkoxyalkyl group, the alkyl and alkoxy portions of which have 1 to 4 carbons each, and the alkoxy portion of which is substituted by a sulpho group or by a sulpho group and a hydroxy group, each of W 1 and W 2 independently is H or alkyl having 1 to 4 carbons, Z is S or Se, X<SP>-</SP> is an anion and n is 1 or 2, in supersensitizing combination with a spectral sensitizing dye of the formula wherein each of R 3 and R 4 independently is alkyl having 1 to 4 carbons which may be substituted or unsubstituted, each of R 5 and R 6 independently is alkyl having 1 to 4 carbons, a hydroxyalkyl or sulphoalkyl group having 1 to 4 carbons or an alkoxyalkyl group, the alkyl and alkoxy portions of which have 1 to 4 carbons each, and the alkoxy portion of which is substituted by a sulpho group or by a sulpho group and a hydroxy group, each of Y 1 and Y 2 independently represents an n-propyl, iso-propyl, n-butyl, iso-butyl or phenyl group, X<SP>-</SP> is an anion, and n is 1 or 2. The emulsion may be a colour emulsion and may contain a magenta colour coupler. This supersensitizing combination has stable greensensitivity even at high temperature and high humidity and does not cause any dye contamination in the resulting film after treatment. The emulsion generates little or no fog even when handled under a safe light having a wavelength of more than 600m Á.