Process for phthalocyanine green pigment
AssigneeAmerican Cyanamid Company
InventorSalvatore F. Torre
Life of this patent
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Abstract
A green copper phthalocyanine pigment composition suitable for rotogravure inks is obtained by adding to the green pigment about 5 to 10% of a water soluble blue copper phthalocyanine dye which is complexed with N-alkyltrimethylammonium chloride.
Claims8
A green shade copper phthalocyanine pigment composition comprising a green copper phthalocyanine pigment having at least 15 halogen atoms per molecule, about 5 to 10% by weight, based on the weight of the pigment, of a non-pigmentary water soluble blue sulfonated copper phthalocyanine dye wherein the sulfonated dye contains at least about 1.8 sulfonic acid groups per molecule, and at least a complexing amount of an N-alkyltrimethylammonium chloride, wherein the alkyl group contains about 8 to 18 carbon atoms, to complex the sulfonic acid groups of the dye.
A process for the preparation of a green shade copper phthalocyanine pigment composition which comprises:
- (1) forming a dispersion of a green copper phthalocyanine pigment containing at least 15 halogen atoms per molecule in water;
- (2) adding thereto about 5 to 10 percent by weight, based on the dry weight of said green pigment, of a water soluble blue sulfonated copper phthalocyanine dye wherein the sulfonated dye contains at least about 1.8 sulfonic acid groups per molecule and at least a complexing amount of an N-alkyltrimethylammonium chloride compound, wherein the alkyl group contains about 8 to 18 carbon atoms, and sufficient sulfuric acid to render the pH below about 4;
- (3) heating said mixture at a temperature of about 90-95.degree. C for a time sufficient for compelxation of said sulfonated copper phthalocyanine dye with said N-alkyltrimethylammonium chloride;
- and (4) isolating said green pigment composition from said mixture.
Dependencies are inferred from the claim text.