Nippon Kayaku Kabushiki Kaisha

Akio Kuwahara

Akira Kawaguchi

Shinjirou Takahashi

An inkjet aqueous pigment dispersion which achieves high pigment concentration, exhibits favorable redispersion properties after drying, and does not exhibit changes in ink properties even when stored for a long time; and an ink composition using the aqueous pigment dispersion. The inkjet aqueous pigment dispersion contains a pigment, a liquid medium, and a polymer dispersion agent which is an A-B block polymer obtained by copolymerization using a mixture of an organic tellurium compound represented by formula (1) and an organic ditellurium compound represented by formula (2) as a polymerization initiator. The monomer for configuring the A block is at least one type of monomer represented by formula (3), and the monomer for configuring the B block is benzyl methacrylate and/or benzyl acrylate. 

Aqueous coloring agent dispersion for inkjet, ink composition, inkjet recording method, and colored body

Disclosed is a monoazo metal complex represented by the formula (1) wherein Rrepresents a hydrogen atom, a C-Calkyl group, a C-Calkoxy group, a chlorine atom, a bromine atom or a nitro group; M represents a hydrogen atom, a sodium, a potassium, a magnesium, a calcium, a barium or an aluminum; Mrepresents a n-valent cation; Metal represents Ni, Fe, Cu, Co or Al; m represents an integer of 1 or 2; and n represents an integer of 1, 2 or 3.

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Tokyo, Japan

Akio Kuwahara