Patent ID: 6159667
Filing Date: 2000-12-12
Classification: C07C,G03C

Abstract:
A process for producing particles of a substantially light-insensitive organic silver salt, said particles containing silver behenate, said process comprising:(i) preparing a solution or dispersion, A, containing an alkali metal or ammonium salt of an organic compound with at least one acidic hydrogen atom, said organic compound including behenic acid, said salt of the organic compound containing alkali or ammonium ions, in a mixture of water and an organic solvent, at a temperature at which particles of said substantially light-insensitive organic silver salt containing silver behenate do not undergo reduction; and(ii) adding a quantity of an aqueous solution, B, of a silver salt containing an equal number of silver ions to the alkali or ammonium ions in said solution or dispersion A;wherein an initial mixing number during said addition of said aqueous solution B to said solution or dispersion A is greater than or equal to 2.times.10.sup.-4 during said production of said particles of substantially light-insensitive organic silver salt containing silver behenate, said mixing number being defined as the ratio of the molar rate at which said silver salt is supplied to said solution or dispersion A in a reactor to the molar rate at which said alkali or ammonium salt of the organic compound is circulated in said reactor; and wherein said particles of the substantially light-insensitive organic silver salt, said particles containing silver behenate, are not associated with mercury and/or lead ions.