Patent ID: 6454844
Filing Date: 2002-09-24
Classification: C09D

Abstract:
An ink set comprising: a yellow ink composition; first and second magenta ink compositions different from each other in color density, wherein the first magenta ink composition has a higher color density and the second magenta ink composition has a lower color density; and first and second cyan ink compositions different from each other in color density, wherein the first cyan ink composition has a higher color density and the second cyan ink composition has a lower color density,said yellow ink composition containing as a colorant a compound represented by formula (I) or (II): â€ƒwherein R1, R1â€², R2, and R2â€² each independently represent CH3 or OCH3; and A and Aâ€² each independently represent a group having a structure selected from the group consisting of â€ƒwherein M represents a hydrogen atom, lithium, sodium, potassium, ammonium, or an organic amine; and n is an integer of 1 or 2, said first magenta ink composition with higher color density containing as a colorant a compound represented by formula (III): â€ƒwherein B and Bâ€² each independently represent a hydrogen atom or a group represented by formula â€ƒwherein R2 represents OH, COOM, or NHR5 wherein R5 represents an SO3Mâ€” or COOH-substituted C1-C4 alkyl group; R3 represents a hydrogen atom or an OHâ€” or COOH-substituted C1-C4 alkyl group; and R4 represents an OHâ€”, OCH3â€”, OC2H5â€”, SO3Mâ€”, or COOM-substituted C1-C4 alkyl or phenyl group, provided that B and Bâ€² do not simultaneously represent a hydrogen atom; R1 represents a C1-C4 alkyl or alkoxy group, OH, SO3M, or COOH; and M represents a hydrogen atom, lithium, sodium, potassium, ammonium, or an organic amine, said second magenta ink composition with lower color density containing as a colorant the compound represented by formula (III) or a compound represented by formula (V): â€ƒwherein X represents an anilino group substituted by at least one SO3M; Y represents OH, Cl, or a morpholino group; and M represents a hydrogen atom, lithium, sodium, potassium, ammonium, or an organic amine, said first cyan ink composition with higher color density and said second cyan ink composition with lower color density each containing as a colorant a compound represented by formula (IV): â€ƒwherein R6 represents OH or COOM; and p, m, and n are each 0 to 4 with (p+m+n)=4.