Process for the preparation of silver halide grains
AssigneeFuji Photo Film Co., Ltd.
InventorsShigeharu Urabe, Haruyasu Nakatsugawa, Mario Ishiyama
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Abstract
Disclosed is a novel process for the preparation of tabular silver halide grains having parallel twinning planes which comprises the steps of: 1) supplying an aqueous solution of a water-soluble silver salt, an aqueous solution of a water-soluble halide and an aqueous solution of a protective colloid into a mixing machine provided external to a reaction vessel where they are mixed to form nuclear grains; and 2) introducing the nuclear grains into a ripening vessel comprising a pipe where they are ripened at an elevated temperature.
Claims12
A process for the preparation of tabular silver halide grains having parallel twinning planes via at least a nucleation procedure and a subsequent ripening procedure, which comprises effecting nucleation and ripening in a mixing machine and a ripening vessel provided external to a reaction vessel, and then introducing said grains into said reaction vessel where they are allowed to grow, in accordance with the following procedures:
- 1) supplying an aqueous solution of a water-soluble silver salt, an aqueous solution of a water-soluble halide and an aqueous solution of a protective colloid into a mixing machine provided external to said reaction vessel where they are mixed at a temperature of 5.degree. C. to 40.degree. C. to form nuclear grains;
- 2) introducing said nuclear grains into a ripening vessel comprising a pipe where they are ripened at an elevated temperature of 50.degree. C. to 95.degree. C. with the ripening being completed in the ripening vessel;
- and
- 3) introducing said ripened grains into said reaction vessel equipped with an agitator where they are allowed to grow;
- wherein grains formed at different times in the mixing machine are not mixed with each other in the ripening vessel.
A process for the preparation of tabular silver halide grains having parallel twinning planes said process consisting essentially of a nucleation procedure and a ripening procedure, which comprises effecting nucleation and ripening in a mixing machine and a ripening vessel, respectively, in accordance with the following steps:
- 1) supplying an aqueous solution of a water-soluble silver salt, an aqueous solution of a water-soluble halide and an aqueous solution of a protective colloid into a mixing machine where they are mixed at a temperature of 5.degree. C. to 40.degree. C. to form nuclear grains;
- and
- 2) introducing said nuclear grains into a ripening vessel comprising a pipe where they are ripened at an elevated temperature of 50.degree. C. to 95.degree. C. with the ripening being completed in the ripening vessel;
- wherein the grains formed at different times in the mixing machine are not mixed with each other in the ripening vessel.
A process for the preparation of tabular silver halide grains having parallel twinning planes via at least a nucleation procedure and a subsequent ripening procedure, which comprises effecting nucleation and ripening in a mixing machine and a ripening vessel provided external to a reaction vessel, and then adding the emulsion thus obtained to the system in said reaction vessel as an emulsion of tabular silver halide seed grains, in accordance with the following steps:
- 1) supplying an aqueous solution of a water-soluble silver salt, an aqueous solution of a water-soluble halide and an aqueous solution of a protective colloid into mixing machine provided external to said reaction vessel where they are mixed at a temperature of 5.degree. C. to 40.degree. C. to form nuclear grains;
- 2) introducing said nuclear grains into a ripening vessel comprising a pipe where they are ripened at an elevated temperature of 50.degree. C. to 95.degree. C. with the ripening being completed in the ripening vessel;
- 3) cooling and storing the ripened groups;
- and
- 4) adding said ripened grains as an emulsion of seed grains to said reaction vessel;
- wherein the grains formed at different times in the mixing machine are not mixed with each other in the ripening vessel.
Dependencies are inferred from the claim text.