Asahi Kasei Kogyo Kabushiki Kaisha

Asahi Kasei Kabushiki Kaisha

Toshihiko Matsui

Kunihiko Okajima

Kenji Kamide

Hirofumi Ono

Chihiro Yamane

Ikuya Miyamoto

A cellulose dispersion which is a dispersion comprising a dispersing medium and a cellulose having a fraction of cellulose I type crystal component of not more than 0.1 and a fraction of cellulose II type crystal component of not more than 0.4 and in which the average particle diameter of the constitutive cellulose is not more than 5 &mgr;m. A cellulose particulate and a cellulose composite particulate which have an average particle diameter of 0.2 to 20 &mgr;m, a ratio of long diameter (L) to short diameter (D) observed through a scanning electron microscope (L/D) of not more than 1.2 and a coefficient of aggregation of 1.0 to 3.0. The present invention provides a cellulose dispersion which has an excellent effect such as dispersion stability or the like and is high in transparency. Moreover, it provides a cellulose particulate and a cellulose composite particulate which have such performances as no rough feel, excellent rolling properties, high dispersibility and the like.

Cellulose dispersion

Process for producing celluose moldings

A mesophase dope useful for producing shaped articles, for example, filaments and films, comprises at least 10% by weight of at least one cellulose derivative and the balance consisting of an aqueous solution of at least 5% by weight of at least one inorganic acid, the dope exhibiting the mesophase property even in the case where no fluid dynamic stress is applied thereto.

Mesophase dope containing cellulose derivative and inorganic acid

A cellulose sulfate salt having a heparinic action is provided, which satisfies requirements of 0.8.ltoreq.&lt;&lt;F&gt;&gt;.ltoreq.2.6, &lt;&lt;f.sub.2 &gt;&gt;.gtoreq.&lt;&lt;f.sub.3 &gt;&gt; and &lt;&lt;f.sub.2 &gt;&gt;.gtoreq.&lt;&lt;f.sub.6 &gt;&gt; wherein &lt;&lt;f.sub.2 &gt;&gt;, &lt;&lt;f.sub.3 &gt;&gt; and &lt;&lt;f.sub.6 &gt;&gt; stand for probability of substitution of atoms H in the OH groups bonded to the C.sub.2, C.sub.3 and C.sub.6 positions of the glucopyranose ring unit by sulfuric acid radicals, respectively, and &lt;&lt;F&gt;&gt; stands for the total substitution degree which is the sum of &lt;&lt;f.sub.2 &gt;&gt;, &lt;&lt;f.sub.3 &gt;&gt; and &lt;&lt;f.sub.6 &gt;&gt;. The cellulose sulfate salt is prepared by reacting a cellulose having a crystal form I with an SO.sub.3 /amine or SO.sub.3 /amide complex in an amount of 2 to 4 mole equivalents per glucose unit of the cellulose at -10.degree. C. to 40.degree. C. to form a gelatinous product; adding water to the gelatinous product in an amount 0.1 to 5 times the amount of the starting cellulose used for the reaction; treating the mixture at a high temperature to relatively reduce the values of &lt;&lt;f.sub.6 &gt;&gt; and &lt;&lt;f.sub.3 &gt;&gt; among the values of &lt;&lt;f.sub.2 &gt;&gt;, &lt;&lt;F.sub.3 &gt;&gt; and &lt;&lt;f.sub.6 &gt;&gt;; neutralizing, precipitating and drying the so obtained crude cellulose sulfate; dissolving the crude cellulose sulfate in water again; treating the solution with an adsorbent; and subjecting the treated cellulose sulfate to precipitation, drying, re-dissolution, dialysis, precipitation and then drying.

Cellulose sulfate salt having anti-coagulating action and process for

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Takatsuki, Japan

Toshihiko Matsui