Patent ID: 7717990

Claim:
A multi-color inkjet ink set, comprising: a first ink composition comprising a first colorant and a heterocyclic amine compound; and a second ink composition comprising a second colorant having at least one acid moiety to react with the heterocyclic amine compound to form a precipitate, wherein a mole ratio of the heterocyclic amine compound to the at least one acid moiety is in a range of greater than 0.5 to about 10, wherein the heterocyclic amine compound is at least one member selected from the group consisting of a pyrrole derivative, a pyridine derivative, a quinoline derivative, an isoquinoline derivative, a pyrrolidine derivative, and a piperidine derivative, and wherein the derivative is a compound in which a hydrogen atom therein is substituted with one member selected from the group consisting of, a hydroxy group, a substituted or unsubstituted alkylene group having 1 to 15 carbons, a substituted or unsubstituted heteroalkylane group, a substituted or unsubstituted arylene group, a substituded or unsubstituded heteroarylene group, a halogen atom, an amino group, and a nitro group.