Abstract: A tobacco smoke filter material comprises a fibrillated cellulose ester fiber with an average fiber diameter of 15 to 250 .mu.m and a BET specific surface area of 0.5 to 4.5 m.sup.2 /g. The fibrous cellulose ester content of the material may for example be not less than 20 weight %. The cellulose ester fiber is provided by, for example, extruding a cellulose ester solution from a nozzle into a precipitating agent for the particular cellulose ester and subjecting the extrudate to a shear force. This filter material can be used in the form of, for example, a filament, web or sheet to provide a tobacco smoke filter which assures good smoking qualities and excellent wet disintegratability.

Abstract: A tobacco filter material containing fibers which have a core and a surface layer which surrounds the core, wherein the core comprises a non-esterified cellulose and the surface layer comprises a cellulose ester. The fiber may be (A) a cellulose fiber coated with a cellulose ester or (B) a fibrous cellulose derivative with its surface layer esterified by an organic acid and having an average degree of substitution of not more than 1.5. Wood pulp can be used as the cellulose fiber and the amount of the cellulose ester in the coated cellulose (A) is 0.1% by weight or more. The cellulose derivative (B) has its surface layer esterified with an organic acid and retains a non-esterified core portion. This cellulose derivative may be obtained, for example, by the non-catalytic liquid phase treatment of a cellulose fiber with an organic acid and an organic acid anhydride or halide.

Abstract: A process for the preparation of a cellulose acetate film comprises the steps of: cooling a mixture of cellulose acetate and an organic solvent to -100.degree. to -10.degree. C.; warming the cooled mixture to 0.degree. to 50.degree. C. to dissolve the cellulose acetate in the organic solvent; casting the obtained solution on a support; and evaporating the organic solvent to form the cellulose acetate film. The cellulose acetate has an average acetic acid content in the range of 58.0 to 62.5%. The organic solvent is acetone.

Abstract: A tobacco smoke filter material has a fibrillated cellulose ester fiber with an average fiber diameter of 15 to 250 .mu.m and a BET specific surface area of 0.5 to 4.5 m.sup.2 /g. The fibrous cellulose ester content of the material may for example be not less than 20 weight %. The cellulose ester fiber is provided by, for example, extruding a cellulose ester solution from a nozzle into a precipitating agent for the particular cellulose ester and subjecting the extrudate to a shear force. This filter material can be used in the form of, for example, a filament, web or sheet to provide a tobacco smoke filter which assures good smoking qualities and excellent wet disintegratability.

Abstract: A tobacco filter is obtained by shaping a sheet material having a web structure and comprising (1) cellulose acetate or other cellulose ester short staple, and (2) a binder fiber selected from polysaccharides or their derivatives and biodegradable polymers, and having a binding property with respect to the short staple into a rod-form. The fiber (2) includes (2a) an esterified cellulose fiber, (2b) a cellulose fiber coated with a cellulose ester, (2c) a fibrillated cellulose ester fiber having a BET specific surface area of 0.5 to 4.5 m.sup.2 /g, and (2d) a cellulose fiber at least a part of its surface has been water-solubilized. The sheet material may further comprise a wood pulp or other beaten pulps.

Abstract: A tobacco filter is produced by wrapping up a sheet-like filter material having a web structure and comprising a cellulose ester short staple into a rod-form. As the cellulose ester short staple, a short staple that is non-crimped and/or has a modified cross section where a ratio D1/D2 of a diameter D1 of the circumscribed circle to a diameter D2 of the inscribed circle, each circle being of the cross section, of not less than 2 is used. The short staple includes e.g. a cellulose acetate fiber with an average fiber length of 1 to 10 mm and fineness of 1 to 10 deniers. The short staple may be incorporated with a beaten pulp with a Schopper-Riegler freeness of 20 to 90.degree. SR and/or a binder. The ratio of the short staple to the beaten pulp may for example be about 90/10 to 20/80 (by weight).

Abstract: A cellulose acetate solution has cellulose acetate in a solvent. The cellulose acetate has an average acetic acid content in the range of 58.0 to 62.5%. In the first embodiment of the invention, the solvent is a mixture of acetone and another organic solvent. The organic solvent is an ether having 3 to 12 carbon atoms, a ketone having 4 to 12 carbon atom, an ester having 3 to 12 carbon atoms, or an alcohol having 1 to 6 carbon atoms. In the second embodiment, the solvent is the ether, the ketone or the ester. Processes for the preparation of the solution and a cellulose acetate film are also disclosed.

Abstract: Separation of a chemical substance is effected by treating a mixture thereof with a polysaccharide having a substituent for hydroxyl group an acyl group of the formula (1) or a carbamoyl group of the formula (2): ##STR1## wherein R represents an atomic group having a nucleus comprising a conjugated .pi.-bond system in which the number of bonds interposed between an atom contained therein and bonded with the carbonyl or amino group and an atom contained in the .pi.-bond system and most distant from said atom is at least 5 even in the shortest route.

Abstract: A separation agent essentially comprises an aliphatic or aromatic ester of a polysaccharide, except for cellulose acetate and an aromatic ester of cellulose. It is useful for separation of various chemical substances, especially optical resolution of optical isomers.

Abstract: A separation agent essentially comprises an aliphatic or aromatic ester of a polysaccharide, except for cellulose acetate and an aromatic ester of cellulose. It is useful for separation of various chemical substances, especially optical resolution of optical isomers.

Abstract: Separation of a chemical substance is effected by treating a mixture thereof with a polysaccharide having a substituent for hydroxyl group an acyl group of the formula (1) or a carbamoyl group of the formula (2): ##STR1## wherein R represents an atomic group having a nucleus comprising a conjugated .pi.-bond system in which the number of bonds interposed between an atom contained therein and bonded with the carbonyl or amino group and an atom contained in the .pi.-bond system and most distant from said atom is at least 5 even in the shortest route.

Abstract: Separation of a chemical substance is effected by treating a mixture thereof with a polysaccharide having a substituent for hydroxyl group an acyl group of the formula (1) or a carbamoyl group of the formula (2): ##STR1## wherein R represents an atomic group having a nucleus comprising a conjugated .pi.-bond system in which the number of bonds interposed between an atom contained therein and bonded with the carbonyl or amino group and an atom contained in the .pi.-bond system and most distant from said atom is at least 5 even in the shortest route.

Abstract: A separation agent essentially comprises an aliphatic or aromatic ester of a polysaccharide, except for cellulose acetate and an aromatic ester of cellulose. It is useful for separation of various chemical substances, especially optical resolution of optical isomers.

Abstract: A separation agent essentially comprises an aliphatic or aromatic ester of a polysaccharide, except for cellulose acetate and an aromatic ester of cellulose. It is useful for separation of various chemical substances, especially optical resolution of opticl isomers.

Abstract: Separation of a chemical substance is effected by treating a mixture thereof with a polysaccharide having a substituent for hydroxyl group an acyl group of the formula (1) or a carbamoyl group of the formula (2): ##STR1## wherein R represents an atomic group having a nucleus comprising a conjugated .pi.-bond system in which the number of bonds interposed between an atom contained therein and bonded with the carbonyl or amino group and an atom contained in the .pi.-bond system and most distant from said atom is at least 5 even in the shortest route.

Abstract: A separation agent essentially comprises an aliphatic or aromatic ester of a polysaccharide, except for cellulose acetate and an aromatic ester of cellulose. It is useful for separation of various chemical substances, especially optical resolution of optical isomers.

Abstract: Separation of a chemical substance is effected by treating a mixture thereof with a polysaccharide having a substituent for hydroxyl group an acyl group of the formula (1) or a carbamoyl group of the formula (2): ##STR1## wherein R represents an atomic group having a nucleus comprising a conjugated .pi.-bond system in which the number of bonds interposed between in atom contained therein and bonded with the carbonyl or amino group and an atom contained in the .pi.-bond system and most distant from said atom is at least 5 even in the shortest route.

Abstract: A separation agent essentially comprises an aliphatic or aromatic ester of a polysaccharide, except for cellulose acetate and an aromatic ester of cellulose. It is useful for separation of various chemical substances, especially optical resolution of optical isomers.

Abstract: A separation agent essentially comprises an aliphatic or aromatic ester of a polysaccharide, except for cellulose acetate and an aromatic ester of cellulose. It is useful for separation of various chemical substances, especially optical resolution of optical isomers.

Abstract: A mixture of chemical substances such as optical isomers, geometrical isomers and polymers having different molecular weight ranges is separated to each ingredient by use of a cellulose derivative having an aromatic ring in the chromatographic method.