Pigment dispersion

A method of preparing modified pigment particles, comprising;

• (a) preparing an aqueous slurry of pigment particles of the formula X.sub.a Y.sub.b (Z(L1).sub.n (L2).sub.m).sub.c, where X is an alkaline earth metal, Y is a transition metal or a heavy metal, Z is a transition metal or a heavy metal, L1 and L2 are ligands selected from the group consisting of mono-dentate ligands and bi-dentate ligands, a is 1 or 0, b and c are integers from 1-6, and n and m are integers from 0-6, such that the pigment particles are present in an amount from about 1% to about 20% by weight of the slurry;
• (b) adjusting the pH of the slurry;
• (c) adding a surface derivatizing agent having a 1,3 diketo moiety and a phenolic moiety or a surface derivatizing agent which is a phenol substituted with one or more substituents selected from the group consisting of cycloalkyl, alkenyl, alkynyl, alkoxy, keto, diketo, pyrido, benzo, alkylcarbonyl, halo, cycloalkylcarbonyl, hydroxyalkyl, haloalkyl, alkoxyalkyl, unsubstituted alkyl, and combinations thereof, to the slurry in an amount less than about 10% by weight of the pigment particles;
• (d) mixing the surface derivatizing agent into the slurry to obtain modified pigment particles;
• and
• (e) recovering and drying the modified pigment particles.

A pigment dispersion, comprising

• (a) a pigment of the formula X.sub.a Y.sub.b (Z(L1).sub.n (L2).sub.m).sub.c, where X is an alkaline earth metal, Y is a transition metal or heavy metal, Z is a transition metal or heavy metal, L1 and L2 are ligands selected from the group consisting of mono-dentate ligands and bi-dentate ligands, a equals 1 or 0, b is an integer from 1-6, c is an integer from 1-6 and n and m equal an integer from 0 to 6;
• (b) a surface derivatizing agent having a 1,3 diketo moiety and a phenolic moiety, or a surface derivatizing agent which is a phenol substituted with one or more substituents selected from the group consisting of cycloalkyl, alkenyl, alkynyl, alkoxy, keto, diketo, pyrido, benzo, alkylcarbonyl, halo, cycloalkylcarbonyl, hydroxyalkyl, haloalkyl, alkoxyalkyl, unsubstituted alkyl, and combinations thereof;
• (c) an organic vehicle;
• and
• (d) one or more solvents, selected from the group consisting of water, alcohol, aromatic solvents, aliphatic solvents, halogenated hydrocarbons, aromatic oils, aliphatic oils, glycol ethers, esters, and ketones.

A method of preparing modified pigment particles, comprising:

• (a) preparing an aqueous slurry of milori blue pigment particles, such that the pigment particles are present in an amount from about 1% to about 20% by weight of the slurry;
• (b) adjusting the pH of the slurry to a pH of about 6.0 to about 6.6;
• (c) adding a surface derivatizing agent having a 1,3 diketo moiety and a phenolic moiety or a surface derivatizing agent which is a phenol substituted with one or more substituents selected from the group consisting of cycloalkyl, alkenyl, alkynyl, alkoxy, keto, diketo, pyrido, benzo, alkylcarbonyl, halo, cycloalkylcarbonyl, hydroxyalkyl, haloalkyl, alkoxyalkyl, unsubstituted alkyl, and combinations thereof, to the slurry in an amount from about 1% to about 10% by weight of the pigment particles;
• (d) mixing the surface derivatizing agent into the slurry to obtain modified pigment particles;
• and
• (e) separating and drying the modified pigment particles.