Silver halide photographic light-sensitive material

#The present invention relates to a silver halide emulsion, more specifically, the present invention relates to a silver halide emulsion ensuring high sensitivity, high contrast and low fog, reduced in the fluctuation of sensitivity due to difference in the humidity condition in aging after exposure or at the exposure, and exhibiting excellent reciprocity law characteristics at high illuminance. The present invention also relates to a production method of the emulsion and a silver halide photographic light-sensitive material using the emulsion.

#The silver halide emulsion for use in silver halide photographic light-sensitive materials is usually subjected to a chemical sensitization using various chemical substances so as to obtain desired sensitivity and gradation. Representative examples of known chemical sensitization methods include sulfur sensitization, selenium sensitization, tellurium sensitization, noble metal sensitization using gold or the like, reduction sensitization and various sensitization methods using a combination thereof. Recently, silver halide photographic light-sensitive materials are strongly demanded to have high sensitivity, excellent graininess, high sharpness and rapid processability with expedited progress of development and to cope with these requirements, various improvements have been made on the above-described sensitization methods.

#Also, color printing papers are demanded to have enhanced sensitivity, image quality and performance at the processing, such as toughness, and to satisfy these requirements, an emulsion ensuring high sensitivity and high contrast and an emulsion reduced in the fluctuation of photographic properties due to difference in the temperature and humidity conditions at exposure are demanded. On the other hand, apparatuses for laser scanning exposure are recently widespread and therefore, suitability for short-time and high-illuminance exposure becomes one of importance performances. The laser scanning exposure is greatly characterized in that the exposure can be performed at a high speed and the resolution can be improved. However, the color printing paper to which the laser scanning exposure is applied must have suitability for unprecedentedly short-time (specifically 10−6 sec.) and high-illuminance exposure.

#In 300 ml of distilled water, 2.93 g of chloroauric acid tetrahydrate was dissolved and thereto, 1.77 g of potassium carbonate was added. To a solution obtained by dissolving 4.25 g of Compound 1-28 of the present invention in 400 ml of distilled water, the chloroauric acid solution prepared above was gradually added and thereafter, the resulting solution was stirred for 30 minutes to obtain an aqueous solution of Compound 2-11.

#In 250 ml of distilled water, 2.61 g of chloroauric acid tetrahydrate was dissolved and thereto, 1.75 g of potassium carbonate was added. To a solution obtained by dissolving 4.62 g of Compound 1-2 of the present invention in 400 ml of distilled water, the chloroauric acid solution prepared above was gradually added and thereafter, the resulting solution was stirred for 30 minutes to obtain an aqueous solution of Compound 2-2.

#The amount of the compound represented by formula (1) or (2) for use in the present invention varies over a wide range according to the case, however, is generally from 1×10−6 to 5×10−3 mol, preferably from 5×10−6 to 5×10−4 mol, per mol of silver halide. The compound represented by formula (1) or (2) for use in the present invention can be added in any stage from immediately after the grain formation until immediately before the completion of chemical sensitization, but is preferably added in the period between after desalting and during chemical sensitization.