Patent ID: 7615113

Claim:
An ink comprising at least a coloring material, wherein: the coloring material comprises a compound represented by a following general formula (I) or a salt thereof; and the maximum absorption wavelengths obtained by measuring an absorbance of a liquid prepared by diluting 2,000 times the ink by mass with 90 mass % of N,N-dimethylformamide aqueous solution are respectively in a range of 580 nm or more and 640 nm or less and in a range of 650 nm or more and 700 nm or less; and a ratio B/A of 0.75 or more and 0.90 or less, wherein A is an absorbance at a maximum absorption wavelength in the range of 580 nm or more and 640 nm or less, and B is an absorbance at the maximum absorption wavelength in a range of 650 nm or more and 700 nm or less: wherein M represents an alkali metal or ammonium; R 1 and R 2 each independently represents a hydrogen atom, a sulfonic group, or a carboxyl group, provided that R 1 and R 2 are not simultaneously a hydrogen atom; Y represents a chlorine atom, a hydroxyl group, an amino group, or a monoalkylamino or dialkylamino group; 1 represents 0 to 2, m represents 1 to 3, and n represents 1 to 3, provided that 1+m+n=2 to 4, where the copper phthalocyanine possesses a substituent in at least one of 3-position and 3′-position in at least one benzene ring.