Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Provided is a semipermeable membrane with high chlorine resistance and high alkali resistance. A cellulose mixed ester represented by a structural formula of General Formula (I), wherein when X is an aromatic acyl group, a degree of substitution is from 2.91 to 3.0; the aromatic acyl group includes a benzoyl group (A) that may include a substituent, and an aromatic acyl group (B) containing a carboxyl group or a salt of a carboxyl group; when the degree of substitution is 3.0, a degree of substitution of the benzoyl group (A) that may include a substituent is from 2.4 to 2.95, and a degree of substitution of the aromatic acyl group (B) containing a carboxyl group or a salt of a carboxyl group is from 0.05 to 0.6; and in General Formula (I), all or part of Xs are aromatic acyl groups; when part of Xs are aromatic acyl groups, the remainder represents a hydrogen atom or an alkyl group; and n represents an integer from 20 to 20000.

Abstract: 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.

Abstract: 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.

Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. The starter switch (36) detects cranking initiation, and the crank angle sensor (33, 34) detects the number of revolutions of the engine. The controller (31) drives the throttle (23) in a closed position along with the cranking initiation. The controller (31) can obtain both the intake negative pressure for promoting vaporization of fuel and the intake air amount necessary to maintain the idle rotation speed by counting the number of strokes or the number of revolutions of the internal combustion engine (1) from the cranking initiation and opening the throttle (23) from the closed position as the count number reaches a predetermined number.

Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. As the cranking is initiated, an atmospheric pressure is detected and an initial opening is set accordingly. The controller (31) controls the throttle (23) to the initial opening when the cranking is initiated, and controls the throttle to start to increase the throttle opening from the initial opening at a predetermined timing after the cranking initiation. By setting the initial opening based on one or both of the atmospheric pressure and the temperature at the time of cranking initiation, the intake negative pressure and the intake air amount are optimized.

Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. As the cranking is initiated, an atmospheric pressure is detected and an initial opening is set accordingly. The controller (31) controls the throttle (23) to the initial opening when the cranking is initiated, and controls the throttle to start to increase the throttle opening from the initial opening at a predetermined timing after the cranking initiation. By setting the initial opening based on one or both of the atmospheric pressure and the temperature at the time of cranking initiation, the intake negative pressure and the intake air amount are optimized.

Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. The starter switch (36) detects cranking initiation, and the crank angle sensor (33, 34) detects the number of revolutions of the engine. The controller (31) drives the throttle (23) in a closed position along with the cranking initiation. The controller (31) can obtain both the intake negative pressure for promoting vaporization of fuel and the intake air amount necessary to maintain the idle rotation speed by counting the number of strokes or the number of revolutions of the internal combustion engine (1) from the cranking initiation and opening the throttle (23) from the closed position as the count number reaches a predetermined number.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

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 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).

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.