Dainichiseika Color & Chemicals Mfg. Co., Ltd.

Jun Kamabayashi

Hiroyuki Shimanaka

Yoshikazu Murakami

Sachio Yoshikawa

Seiji Doi

Toshie Okubo

Lu Tian

Akifumi Tanaka

Yuzuru Sato

Kazutaka Arai

Toshiyasu Fujita

The present invention provides a carbon material dispersion in which a carbon material is contained at a high concentration in a liquid medium containing an organic solvent but is unlikely to reaggregate and is stably dispersed, and from which various products, such as an ink capable of forming a coating film having excellent electric conductivity, can be formed. This carbon material dispersion contains a carbon material, an organic solvent, and a polymeric dispersant, wherein the polymeric dispersant is a polymer having 3 to 55% by mass of a constituent unit (1) represented by the following formula (1), wherein R represents a hydrogen atom or the like, A represents O or NH, B represents an ethylene group or the like, Rand Reach independently represent a methyl group or the like, Ar represents a phenyl group or the like, X represents a chlorine atom or the like, and p represents an arbitrary number of repeating units, and the polymeric dispersant has an amine value of 100 mgKOH/g or less and a number average molecular weight of 5,000 to 20,000.

Carbon material dispersion

The present invention provides an A-B block copolymer that enables preparation of a polymer emulsion useful as a binder component for an aqueous inkjet ink that is excellent in inkjet printability and is capable of forming a printed film excellent in durability, such as adhesiveness and rub resistance, on a substrate to be printed, such as a polyolefin-based plastic film. The block copolymer is an A-B block copolymer satisfying the following requirements (1-1) to (1-3). (1-1) Containing 90% by mass or more of a constituent unit derived from a methacrylate-based monomer or the like. (1-2) The chain A has a constituent unit (A-i) derived from methyl methacrylate or the like and a constituent unit (A-ii) derived from 2-ethylhexyl methacrylate or the like. (1-3) The chain B has a constituent unit (B) derived from methacrylic acid, a constituent unit (B-i) derived from methyl methacrylate or the like, and a constituent unit (B-ii) derived from 2-ethylhexyl methacrylate or the like.

A-B block copolymer, polymer emulsion and water-based inkjet ink

There is provided a carbon material dispersion which has excellent dispersibility and in which the dispersibility is retained stably over a long period of time even when the carbon material dispersion contains a carbon material at a high concentration. The carbon material dispersion is a carbon material dispersion containing a carbon material, water, and a polymeric dispersant, wherein the polymeric dispersant is a polymer including 5 to 40% by mass of a constituent unit (1) derived from a monomer 1, such as 2-vinylpyridine, 50 to 80% by mass of a constituent unit (2) derived from a monomer 2 represented by formula (1) (wherein Rrepresents a hydrogen atom or the like, A represents O or NH, X represents an ethylene group or a propylene group, Y represents O, NHCOO, or NHCONH, each of Rrepresents a hydrogen atom or the like, n represents 20 to 100, and Rrepresents a hydrogen atom or the like), and 0.5 to 40% by mass of a constituent unit (3) derived from a monomer 3 copolymerizable with above-described monomers.

An aqueous pigment dispersion for preparing an environmentally conscious aqueous inkjet ink in which a pigment is finely and stably dispersed and which records images having excellent durability, glossiness, color developability, and adhesiveness to various printing substrates. The aqueous pigment dispersion contains a pigment, water, a water-soluble organic solvent, and a polymeric dispersant that disperses the pigment. The polymeric dispersant is a polymer including a constitutional unit (i) derived from (meth)acrylic acid and/or itaconic acid, and a constituent unit (ii) derived from (meth)acrylate derived from biological material, such as ethyl (meth)acrylate, having an acid value of 30 to 250 mgKOH/g, number average molecular weight of 1,000 to 30,000, and a polydispersity index (weight average molecular weight/number average molecular weight) of 2.5 or less. The content of the constituent unit (ii) is 50% by mass or more, and at least part of carboxy groups is neutralized with an alkali.

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Tokyo, Japan

Jun Kamabayashi