To prevent occurrence of problems in the photographic performances of a silver halide photographic roll film, such as change of sensitivity and occurrence of fog by restricting the total amount of free sulfur contained in light- shielding paper to a specified value or less.
A furnace black obtained by introducing a raw material oil into flames produced by burning a heavy oil as fuel is used as a carbon black. The carbon black is formed by feeding a fuel oil 12 and air 13b into the furnace 11 and introducing the raw material oil 15 into the flames 14 and incomplelely combusting the oil 15. The C heavy oil classified into 3 kinds is generally used for manufacture of the carbon black to be used for the light-shielding paper, and an amount of the free sulfur in the carbon black can be reduced to ≤15 ppm by reducing a sulfur content of 0.7 weight % in the C heavy oil. The total amount of free sulfur contained in the light-shielding paper obtained by mixing the carbon black together with paper pulp is reduced to ≤0.3 mg per 1 m2 of the silver halide photographic film.
UMEZAWA YOSHIYUKI
SUGIYAMA HIROAKI
YAMAMOTO TAKESHI
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