Ihara Chemical Industry Co., Ltd.

Eiichi Eto

Satoru Shimoyama

Susumu Shimoyama

Yasuko Noda

Kunio Kataoka

Keiko Maeda

Ujo Maeda

Tasuku Shimoyama

Yoshio Hara

Kazumi Konya

Toyofumi Yamada

Tatsumi Nishimura

Mieko Goto

Process for production of black coloring material and cosmetics

A novel black coloring material is obtained by treating a chitosan with a dyestuff of the lithospermum root. If a water-insoluble chitosan is used as the chitosan, a finely divided black coloring material is obtained, and if a gelatinous chitosan salt is used as the chitosan, a gelatinous black coloring material is obtained. If a water-soluble chitosan, chitosan oligosaccharide or D-glucosamine, or a salt thereof is used as the chitosan, a liquid black coloring material is obtained. If a powdery polymeric substance is treated with such a black coloring material, a polymer-based black coloring material is obtained, and if a fiber is dyed with such a black coloring material, the fiber is dyed to a black color having a low lightness.

Process for preparation of black coloring materials and application

Tetra-N-acetyl-chitotetraose, penta-N-acetylchitopentaose and hexa-N-acetyl-chitohexaose, ones of the water-soluble chitin-oligomers, may be obtained in improved yields, when finely ground chitin is quickly and intimately mixed with a concentrated hydrohalogenic acid containing a particular proportion of the hydrogen halide per a unit quantity of the chitin under the irradiation with ultrasonic waves and also under the agitation by mechanical stirrer, followed by hydrolyzing the chitin in the resulting homogeneous mixture comprising the chitin and the concentrated hydrohalogenic acid while said homogeneous mixture is further continuously irradiated with the ultrasonic waves and also agitated by the mechanical stirrer. From the aqueous phase of the hydrolyzed reaction mixture are recovered the desired water-soluble chitin-oligomers which are each useful as an immunopotentiating, antitumor agent or antifungal, antibacterial agent.

Production of water-soluble chitin-oligomers by partial hydrolysis of

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Numazu, Japan

Eiichi Eto