Patent ID: 7479178

Claim:
An ink set for use as an inkjet ink, comprising: a cyan ink including a phthalocyanine compound represented by Formula I; a magenta ink including an azo dye represented by Formula III; and a yellow ink including a yellow dye containing 1,3-naphthalenedisulphonic acid, 7-[[4-[[4,6-bis-[(3-sulfoprop-1-yl)thio]-1,3,5-triazin-2-yl]amino]-3-methoxyphenyl]azo]tetrasodium salt represented by Formula V; the cyan ink, the magenta ink, and the yellow ink together exhibiting uniform fade when printed together to form an image; wherein Formula I is shown below: wherein M represents a hydrogen atom, a metal atom; or an oxide, hydroxide, or halide thereof; and Pc represents a phthalocyanine nucleus; wherein R 1 and R 2 each independently represents a substituent selected from the group consisting of —SOX 1 , —SO 2 X 1 , SO 2 NX 2 X 3 , —SO 3 X 4 ; X 1 , X 2 , X 3 , and X 4 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group; at least one of R 1 or R 2 has an ionic hydrophilic group as a substituent; and k and l each independently represents an integer ranging from 1 to 3, provided that k and l each independently is selected such that k+l equals 4; and wherein Formula III is shown below: wherein R 21 , R 23 , R 25 , R 27 , R 29 , and R 31 , are independently selected to be hydrogen atom or sulfonate group; R 22 is selected to be hydrogen atom or nitro group; R 26 and R 28 are independently selected to be hydrogen atom or methyl group; R 24 and R 30 are independently selected to be a methyl or sulfonate group; and R 32 is selected to be a methyl or methoxy group; and wherein Formula V is shown below: