Method for producing alkyl cellulose

Patent metadata

Field	Value
Publication number	US-2016168271-A1
Application number	US-201514965149-A
Country	US
Kind code	A1
Filing date	Dec 10, 2015
Priority date	Dec 11, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

Provided is a method for producing an alkyl cellulose having a high viscosity and not having an excessively high gel strength. More specifically, there is provided a method for producing an alkyl cellulose comprising the steps of: mixing a cellulose pulp with a first alkali metal hydroxide solution with stirring to obtain alkali cellulose; reacting the alkali cellulose with an alkylating agent to obtain a first reaction mixture; blending a second alkali metal hydroxide solution with the first reaction mixture with stirring, without further blending of the alkylating agent, to obtain a second reaction mixture; and purifying the second reaction mixture to obtain an alkyl cellulose. There is also provided an alkyl cellulose being produced by the above method and having a degree of substitution of alkyl group of 27 to 33% by weight.

First claim

1 . A method for producing an alkyl cellulose, comprising the steps of:
mixing a cellulose pulp with a first alkali metal hydroxide solution with stirring to obtain alkali cellulose; reacting the alkali cellulose with an alkylating agent to obtain a first reaction mixture; blending a second alkali metal hydroxide solution with the first reaction mixture with stirring, without further blending of the alkylating agent, to obtain a second reaction mixture; and purifying the second reaction mixture to obtain the alkyl cellulose, wherein a ratio of a weight of a first alkali metal hydroxide in the first alkali metal hydroxide solution to a total weight of the first alkali metal hydroxide and a second alkali metal hydroxide in the second alkali metal hydroxide solution is 50 to 86%.

2 . The method for producing an alkyl cellulose according to claim 1 , wherein a molar ratio (second alkali metal hydroxide/cellulose) of the second alkali metal hydroxide in the second alkali metal hydroxide solution to cellulose in the cellulose pulp is 0.65 to 2.0.

3 . The method for producing an alkyl cellulose according to claim 1 , wherein a blending rate of the second alkali metal hydroxide is 0.5 to 9.6 [mol/mol·hr] where the blending rate is a molar amount of the second alkali metal hydroxide blended with the first reaction mixture per unit time and per mol of cellulose in the cellulose pulp.

4 . The method for producing an alkyl cellulose according to claim 1 , wherein, in the step of blending a second alkali metal hydroxide solution with the first reaction mixture, a temperature in a reactor is 65 to 90° C. at start of the blending.

5 . The method for producing an alkyl cellulose according to claim 1 , wherein, in the step of blending a second alkali metal hydroxide solution with the first reaction mixture, the second alkali metal hydroxide solution is blended while a temperature in the reactor is increased at a constant rate from start of the blending to completion thereof.

6 . The method for producing an alkyl cellulose according to claim 5 , wherein the temperature increase rate is 3.0 to 50° C./hr.

7 . The method for producing an alkyl cellulose according to claim 1 , wherein a molar ratio (first alkali metal hydroxide/cellulose) of the first alkali metal hydroxide in the first alkali metal hydroxide solution to cellulose in the cellulose pulp is 2.0 to 4.0.

8 . An alkyl cellulose having a viscosity at 20° C. of a 1% by weight aqueous solution of the alkyl cellulose of 1,500 to 11,000 mPa·s as measured by a Brookfield viscometer, and having a storage elastic modulus G′(65° C.) at 65° C. of a 1.5% by weight aqueous solution thereof of 2,000 to 4,500 Pa.

9 . The alkyl cellulose according to claim 8 , wherein a 1.5% by weight aqueous solution of the alkyl cellulose has a gelation temperature of 40 to 55° C.

10 . The alkyl cellulose according to claim 8 , having a degree of substitution (DS) of alkyl group of 1.61 to 2.03.

11 . The method for producing an alkyl cellulose according to claim 2 , wherein a blending rate of the second alkali metal hydroxide is 0.5 to 9.6 [mol/mol·hr] where the blending rate is a molar amount of the second alkali metal hydroxide blended with the first reaction mixture per unit time and per mol of cellulose in the cellulose pulp.

12 . The alkyl cellulose according to claim 9 , having a degree of substitution (DS) of alkyl group of 1.61 to 2.03.

Assignees

• Shinetsu Chemical Co
• Se Tylose Gmbh & Co Kg

Inventors

• Kitamura Akira
• Yamamoto Atsushi
• Narita Mitsuo
• Nebel Heiko
• Schultz Andreas

Classifications

• C08L1/28 Primary

  Alkyl ethers · CPC title

• A23V2002/00

  Food compositions, function of food ingredients or processes for food or foodstuffs · CPC title

• C08B11/02 Primary

  Alkyl or cycloalkyl ethers · CPC title

• C08B1/08

  Alkali cellulose · CPC title

• A23D7/003

  Compositions other than spreads (characterised by ingredients other than fatty acid triglycerides A23D7/0053) · CPC title