Nippon Kayaku Kabushiki Kaisha

Shinichi Namba

Takafumi Fujii

Yasuo Shirasaki

Junji Otani

Junko Yoshioka

Hirokazu Kitayama

Kitayama Hirokazu

The present invention relates to a phthalocyanine colorant characterized in that it has, as substituents, at least one unsubstituted sulfamoyl group and at least one substituted sulfamoyl group, the total number of these groups being 2 to 4, the substituent on the substituted sulfamoyl group has a substituted triazinyl group bonded thereto through a crosslinking group, and the unsubstituted sulfamoyl group and the substituted sulfamoyl group are bonded to the phthalocyanine ring at the &#x3b2;-position. Said phthalocyanine colorant is suitable for use in an ink, especially a cyan ink, for an ink-jet printer. A printed matter obtained by printing with said ink is excellent in light fastness, ozone fastness and moisture fastness.

Phthalocyanine colorant and use thereof for ink-jet printing

The present invention relates to a cyan dye mixture, an ink composition containing the mixture and a method of ink-jet recording with the ink composition. The print obtained by the method is characterized by discoloring or fading little even when allowed to stand in a well ventilated shade or in an ozone gas. The cyan dye mixture comprises compounds which are obtained by chlorosulfonating, as a starting material, copper phthalocyanine or a sulfonated copper phthalocyanine and then aminating the chlorosulfonation product with an aminating agent used in an amount of at least 2.5 mol per mol of the starting material, and which are represented by the following formula (1):wherein M represents a proton, alkali metal ion, alkaline earth metal ion, onium ion of an organic amine, or ammonium ion; m is an integer of 1 to 4; and n is an integer of 0 to 3; provided that m+n is an integer of 1 to 4.

Cyan dye mixture, water-based cyan ink composition, and method of ink-jet recording

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Shinichi Namba