Dic Corporation (tokyo)

Dic Corporation

Takaaki Nabe

Yoshinosuke Shimamura

Yukihiko Kawaharada

Yoshihiro Sato

Mariko Toshimitsu

The present invention provides an aqueous pigment dispersion including a pigment, an anionic group-containing organic polymer compound, and bio-nanofibers having an average diameter of 1 nm or more and 100 nm or less and an aspect ratio of 100 or more, and also provides an aqueous ink using the aqueous pigment dispersion. The bio-nanofibers are preferably cellulose nanofibers or chitosan nanofibers. The anionic group-containing organic polymer compound is preferably at least one selected from the group consisting of acrylic resins having anionic groups, polyurethane resins having anionic groups, and polysaccharide derivatives having anionic groups.

Aqueous pigment dispersion and aqueous ink

A method for manufacturing an aqueous black pigment dispersion, including the steps of subjecting a mixture containing carbon black and an aqueous medium to media-less dispersion and adding a resin having anionic groups and a basic compound after the dispersion, wherein the carbon black has a carboxylic acid group on the surface such that the value produced by dividing the amount of carboxylic acid group present on the surface by BET value is 0.8 to 5.5 (&#x3bc;mol/m) and the resin having anionic groups is an urethane resin that satisfies (weight average molecular weight/acid value)&#x3c;1,400 or a styrene acrylic resin that satisfies (weight average molecular weight/acid value)&#x3c;120.

Method for manufacturing aqueous black pigment dispersion

The present invention provides an aqueous pigment dispersion including at least a pigment, colloidal silica, bio-nanofibers having an average diameter of 1 nm to 100 nm and an aspect ratio of 100 or more, an anionic group-containing organic polymer compound, and also provides an aqueous ink. The bio-nanofibers are preferably cellulose nanofibers or chitosan nanofibers, and the ratio between the pigment, the colloidal silica, and the bio-nanofibers preferably satisfies (1) colloidal silica/pigment=1/100 to 20/100 or (2) colloidal silica/bio-nanofibers=1/2 to 10/1 and (3) bio-nanofibers/pigment=1/100 to 15/100.

Growing community of inventors

Saitama, Japan

Takaaki Nabe