Silver halide emulsion, production process thereof and novel pyridinium compound
AssigneeFuji Photo Film Co., Ltd.
InventorsShigeharu Urabe, Shinichi Ichikawa, Kazutaka Takahashi, Tadashi Inaba
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Abstract
A silver halide emulsion comprising tabular grains having a very small thickness with the main surfaces thereof having a very large surface area and being (111) face, is disclosed. More specifically, a silver halide emulsion is disclosed, comprising light-sensitive silver halide grains having a silver bromide content of 70 mol % or more, with 60 % or more of the entire projected area of said silver halide grains being occupied by tabular grains having an average grain thickness of less than 0.04 μm, an average equivalent-circle diameter of 4 μm or more, and (111) face as main surfaces.
Claims6
A method for producing a silver halide emulsion comprising light-sensitive silver halide grains having a silver bromide content of 70 mol % or more, with 60% or more of the entire projected area of said silver halide grains being occupied by tabular grains having an average grain thickness of less than 0.04 μm an average equivalent-circle diameter of 4 μm or more, and (111) face as main surfaces, comprising nucleation, ripening and growth steps and performing these steps while letting at least one compound represented by the following formula (I), (II) or (III) be absent at the time of nucleation and be present at the time of ripening and growth to obtain an emulsion comprising tabular grains, wherein a mixing vessel is separately provided from a reactor for performing the nucleation and/or growth of silver halide grains, an aqueous solution of a water-soluble silver salt and an aqueous solution of a water-soluble halide are fed to said mixing vessel and mixed to form silver halide fine grains, and said fine grains are immediately fed to the reactor to perform the nucleation and/or growth of silver halide grains in said reactor:
- wherein R1 represents an alkyl group, an alkenyl group or an aralkyl group, R2, R3, R4, R5 and R6 each represents a hydrogen atom or a substituent, each of the pairs R2 and R3, R3 and R4, R4 and R5, and R5 and R6 may form a condensed ring, provided that at least one of R2, R3, R4, R5 and R6 represents an aryl group, and X− represents a counter anion;
- wherein A1, A2, A3 and A4, which may be the same or different, each represents a nonmetallic atom group for completing the nitrogen-containing heterocyclic ring, B represents a divalent linking group, m represents 0 or 1, R1 and R2 each represents an alkyl group, X− represents an anion, and n represents 0, 1 or 2, provided that when an inner salt is formed, n is 0 or 1.
A method for producing a silver halide emulsion comprising light-sensitive silver halide grains having a silver bromide content of 70 mol % or more, with 60% or more of the entire projected area of said silver halide grains being occupied by tabular grains having an average grain thickness of less than 0.04 μm, an average equivalent-circle diameter of 4 μm or more, and (111) face as main surfaces, comprising nucleation, ripening and growth steps and performing these steps while letting at least one compound represented by the following formula (V) be absent at the time of nucleation and be present at the time of ripening and growth to obtain an emulsion comprising tabular grains, wherein a mixing vessel is separately provided from a reactor for performing the nucleation and/or growth of silver halide grains, an aqueous solution of a water-soluble silver salt and an aqueous solution of a water-soluble halide are fed to said mixing vessel and mixed to form silver halide fine grains, and said fine grains are immediately fed to the reactor to perform the nucleation and/or growth of silver halide grains in said reactor:
- wherein A represents an organic residue for completing the nitrogen-containing aromatic heterocyclic ring and A's may be the same or different, L1 and L2 each represents a divalent linking group, Y represents —C(═O)—, —SO2—, —NHC(═O)— or —NHC(═S)—, X− represents a counter anion, and na represents a number necessary for neutralizing the electric charge of the compound.
A method for producing a silver halide emulsion comprising light-sensitive silver halide grains having a silver bromide content of 70 mol % or more, with 60% or more of the entire projected area of said silver halide grains being occupied by tabular grains having an average grain thickness of less than 0.04 μm, an average equivalent-circle diameter of 4 μm or more, and (111) face as main surfaces, comprising nucleation, ripening and growth steps and performing these steps while letting at least one compound represented by the following formula (V-A) be absent at the time of nucleation and be present at the time of ripening and growth to obtain an emulsion comprising tabular grains, wherein a mixing vessel is separately provided from a reactor for performing the nucleation and/or growth of silver halide grains, an aqueous solution of a water-soluble silver salt and an aqueous solution of a water-soluble halide are fed to said mixing vessel and mixed to form silver halide fine grains, and said fine grains are immediately fed to the reactor to perform the nucleation and/or growth of silver halide grains in said reactor:
- wherein La represents a divalent linking group constituted by any one or a combination of two or more of an alkylene group, an arylene group and an alkenylene group, Lb represents a divalent group constituted by any one or a combination of two or more of an alkylene group, an arylene group, an alkenylene group, —SO2—, —SO—, —O—, —S—, —CO—, —NH— and —N(R16)—, R16 represents an alkyl group, an alkenyl group, an aralkyl group or an aryl group, Y represents —C(═O)—, —SO2—, —NHC(═O)— or —NHC(═S)—, X− represents a counter anion, na represents a number necessary for neutralizing the electric charge of the compound.
Dependencies are inferred from the claim text.