초록 ▼

A method for forming a dispersion of an oil-soluble photographically useful compound in water or a hydrophilic colloid composition is disclosed, comprising dispersing the compound in the presence of a water-soluble anionic group containing polymeric surfactant, wherein the polymeric surfactant compr

A method for forming a dispersion of an oil-soluble photographically useful compound in water or a hydrophilic colloid composition is disclosed, comprising dispersing the compound in the presence of a water-soluble anionic group containing polymeric surfactant, wherein the polymeric surfactant comprises a copolymer obtained from the copolymerization of a maleic anhydride monomer and a copolymerizable ethylenically unsaturated hydrophobic monomer and the anionic groups of the polymeric surfactant comprise primarily carboxy groups obtained upon base hydrolysis of the anhydride groups of the copolymer. The use of hydrolyzed maleic anhydride derived copolymers in place of conventional small-molecule surfactants as a dispersing agent to stabilize photographically active water-insoluble dye couplers or other organic oil-soluble photographically useful compounds enables a dramatic reduction of crystallization of such organic molecules on long-term keeping. In comparison to primarily sulfonic acid group containing polymeric surfactants, the stabilizing effect of the primarily carboxy group containing hydrolyzed maleic anhydride based polymeric surfactants generally exhibit less molecular weight dependence.

대표청구항 ▼

1. A method for forming a dispersion of an oil-soluble photographically useful compound in water or a hydrophilic colloid composition, comprising dispersing the compound in the presence of a base hydrolyzed maleic anhydride derived water soluble anionic group containing polymeric surfactant, wherein

1. A method for forming a dispersion of an oil-soluble photographically useful compound in water or a hydrophilic colloid composition, comprising dispersing the compound in the presence of a base hydrolyzed maleic anhydride derived water soluble anionic group containing polymeric surfactant, wherein the polymeric surfactant comprises a copolymer obtained from the copolymerization of a maleic anhydride monomer and a copolymerizable ethylenically unsaturated hydrophobic monomer and the anionic groups of the polymeric surfactant comprise primarily carboxy groups that have been obtained upon base hydrolysis of the anhydride groups of the copolymer.