Phosphoric Acid → Silver behenate

Beteiligte Stoffe

Reaktionsschritte

10.6 g of behenic acid and 300 ml of distilled water were mixed at 90° C. for 15 minutes, 31.1 ml of a 1N aqueous solution of NaOH was added thereto over 15 minutes while vigorously stirring, the mixture was allowed to stand for 1 hour, and the temperature was then decreased to 30° C. 7 ml of a 1N aqueous solution of phosphoric acid was added, 0.13 g of N-bromosuccinimide (C-2) was added thereto while stirring more vigorously, and the previously prepared silver halide grains A were then added thereto so that the amount of silver halide became 2.5 moles. 25 ml of a 1N aqueous solution of silver nitrate was further added thereto continuously over 2 minutes, and the mixture was stirred as it was for 90 minutes. 37 g of a 1.2 wt % butyl acetate solution of polyvinyl acetate was added to the aqueous mixture above so as to form a floc dispersion, the water was then removed, the residue was washed with water twice and the water was removed, 20 g of a 2.5 wt % solution of polyvinyl butyral (Denki Kagaku Kogyo K.K., Denka Butyral #3000-K) in a mixture of butyl acetate and isopropyl alcohol at 1:2 was added while stirring, subsequently 7.8 g of polyvinyl butyral (Denki Kagaku Kogyo, Denka Butyral #4000-2) and 57 g of 2-butanone were added to the gel mixture of organic acid and silver halide so obtained and dispersed by a homogenizer to give a silver behenate emulsion (acicular particles having an average short diameter of 0.04 lam, an average long diameter of 1 μm and a variance coefficient of 30%).

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