Modified colored pigments and ink jet inks, inks, and coatings containing modified colored pigments

A method to improve waterfastness of an image generated by an aqueous ink composition comprising the steps of:

• incorporating into said composition a modified colored pigment having attached at least one organic group, the organic group comprising a) at least one aromatic group or a C.sub.1 -C.sub.12 alkyl group, and b) at least one ionic group, at least one ionizable group, or a mixture of an ionic group and an ionizable group, wherein the at least one aromatic group or C.sub.1 -C.sub.12 alkyl group of the organic group is directly attached to the colored pigment and the organic group is present at a treatment level of from about 0.10 to about 4.0 micromoles/m.sup.2 of the colored pigment used based on nitrogen surface area of the colored pigment.

An ink jet ink composition comprising an aqueous or non-aqueous vehicle and a colored pigment having attached an organic group having the formula:

• Ar--R.sup.1 or Ar'R.sup.2 R.sup.3, wherein Ar and Ar' represent an aromatic group, R.sup.1 represents an aromatic or aliphatic group containing a hydrophobic group and a hydrophilic group, R.sup.2 represents a hydrophilic group, and R.sup.3 represents an aromatic or aliphatic group containing a hydrophobic group, wherein said organic group is present at a treatment level of from about 0.10 micromoles/m.sup.2 to about 5.0 micromoles/m.sup.2 pigment, and wherein an image generated from said ink jet ink composition is waterfast.

A method to improve waterfastness of an image generated by an ink jet ink composition comprising introducing a colored pigment having attached an organic group having the formula:

• Ar--R.sup.1 or Ar'R.sup.2 R.sup.3, wherein Ar and Ar' represent an aromatic group, R.sup.1 represents an aromatic or aliphatic group containing a hydrophobic group and a hydrophilic group, R.sup.2 represents a hydrophilic group, and R.sup.3 represents an aromatic or aliphatic group containing a hydrophobic group, and wherein said organic group is present at a treatment level of from about 0.10 micromoles/m.sup.2 to about 5.0 micromoles/m.sup.2 pigment.

A modified pigment comprising a colored pigment having attached at least one organic group, the organic group having the formula:

• Ar--R.sup.1 or Ar'R.sup.2 R.sup.3, wherein Ar and Ar' represent an aromatic group, R.sup.1 represents an aromatic or aliphatic group containing a hydrophobic group and a hydrophilic group, R.sup.2 represents a hydrophilic group, and R.sup.3 represents an aromatic or aliphatic group containing a hydrophobic group, wherein said organic group is present at a treatment level of from about 0.10 micromoles/m.sup.2 to about 5.0 micromoles/m.sup.2 colored pigment.