Daicel Chemical Industries, Ltd.

Daicel Corporation

Fuji Photo Film Company, Limited

Tanabe Seiyaku Company, Limited

Tohru Shibata

Ichiro Okamoto

Hajime Namikoshi

Hiroyuki Matsumura

Syu Shimamoto

Yoshio Okamoto

Koichi Hatada

Tanemi Asai

Mitsuru Ohno

Tomohiro Hashizume

Hiroyuki Nakamura

Hidekazu Yamazaki

Shu Shimamoto

Hiroshi Koyama

Masaaki Ito

Masahiko Murayama

Yoichi Yuki

Kazuhiro Shimoda

Yuichiro Shuto

Hiroyuki Takemoto

Naoto Habu

Tomoichi Watabe

Shoichi Tokutake

Shinji Nagamatsu

Norikazu Fujii

Fumio Yamaguchi

Yoshikazu Tanaka

Hiroshi Inagaki

Takeaki Miyamoto

Hiraku Ito

Kunio Ishii

Hajime Nakikoshi

Masato Shigematsu

A cellulose ester, wherein, in a structural formula of the following general formula (I), a degree of substitution where X is an acyl group is from 2.91 to 3.0; the acyl group includes benzoyl group (A) optionally having a substituent, and benzoyl group (B) optionally having a substituent different from that of benzoyl group (A); and when the degree of substitution is 3.0, a degree of substitution of benzoyl group (A) is from 1.5 to 2.9, and a degree of substitution of benzoyl group (B) is from 0.1 to 1.5, wherein all or some of X represents an acyl group; when some of X represents an acyl group, the remainder represents a group selected from a hydrogen atom and an alkyl group; and n represents an integer of from 20 to 20,000.

Cellulose ester and molded article thereof

Provided is a semipermeable membrane having a high chlorine resistance. The semipermeable membrane is formed of a cellulose ester, the cellulose ester having an optionally substituted benzoyl group.

Semipermeable membrane

A process for adjusting an intermolecular or intramolecular degree of acetyl substitution of cellulose acetate is disclosed. The process comprises ripening cellulose acetate in the presence of a catalyst, an acetyl donor, and water or an alcohol. The amount of water and the alcohol is in the range of 0.1 to 10 mol % based on the amount of the acetyl donor.

Process for adjusting degree of acetyl substitution of cellulose acetate

A process for adjusting an intermolecular or intermolecular degree of acetyl substitution of cellulose acetate is disclosed. The process comprises ripening cellulose acetate in the presence of a catalyst, an acetyl donor, and water or an alcohol. The amount of water and the alcohol is in the range of 0.1 to 10 mol % based on the amount of the acetyl donor.

Method for adjusting the degree of substitution with acetyl group of cellulose acetate

To a constitutive element of a tobacco (a leaf-tobacco component or a filter) is added a proanthocyanidin or a proanthocyanidin-carrying porous material (such as an active carbon) to obtain an element for tobacco smoke. The proanthocyanidin may be at least one extract selected from a grape seed or pip, a grape rind or pericarp and squeezed dregs of a grape fruit.

Cigarette filter comprising grape proanthocyanidin

A method for producing a tobacco filter material which is either (A) a coating process for coating the surface of a fibrous or particulate cellulose with a cellulose ester having an average substitution degree of about 2.0 to about 2.6 to give a coated cellulose, and wet webbing the coated cellulose into a sheet, or (B) a treating process for treating a naturally-occurring or regenerated cellulose fiber or particle with an organic acid and an organic acid anhydride or organic acid halide in a liquid phase to give a cellulose derivative.

Method for producing a tobacco filter material

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 rodform. 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).

Tobacco filter material and a tobacco filter as produced using the same

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.

Tobacco smoke filter materials, fibrous cellulose esters, and production

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.

Tobacco filter material and a method for producing the same

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.

Process for the preparation of cellulose acetate film

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.

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. The proportion of the fiber (1) relative to fiber (2) is such that the former/the latter equals about 30/70 to 98/2 (weight %)

Tobacco filter materials and tobacco filter as produced by using the same

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).

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.

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Himeji, Japan

Tohru Shibata