Method for producing alkali cellulose

Patent metadata

Field	Value
Publication number	US-9416199-B2
Application number	US-201214115212-A
Country	US
Kind code	B2
Filing date	Apr 27, 2012
Priority date	May 2, 2011
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

The present invention relates to a method for producing an alkali cellulose with suppressed decrease in the degree of polymerization as well as with small use amount of a basic compound, and to a method for producing a cellulose ether by using the alkali cellulose thus obtained. Provided by the present invention are: (A) a method for producing an alkali cellulose, comprising Step 1 wherein a cellulose-containing raw material is pulverized in the presence of 0.6 to 1.5 mol of a basic compound relative to 1 mol of an anhydroglucose unit that constitutes a cellulose in the said cellulose-containing raw material and under the condition in which the water content therein relative to the cellulose in the cellulose-containing raw material is 10% or less by mass thereby obtaining a cellulose powder mixture having the median diameter of the cellulose-containing raw material made 150 μm or less and Step 2 wherein water content therein is adjusted in the range of 30 to 100% by mass relative to the cellulose by adding water to the cellulose powder mixture thereby obtaining the alkali cellulose in the powder form; and (B) a method for producing a cellulose ether by reacting the alkali cellulose produced by the foregoing production method with an etherification agent.

First claim

The invention claimed is:

1. A method for producing an alkali cellulose comprising:
Step 1 wherein a cellulose-containing raw material of pulp, paper plant stem, and/or plant shells is pulverized in the presence of 0.6 to 1.5 mol of a basic compound relative to 1 mol of an anhydroglucose unit that constitutes a cellulose in the said cellulose-containing raw material and under the condition in which the water content therein relative to the cellulose in the cellulose-containing raw material is 0.01 -10% by mass thereby obtaining a cellulose powder mixture having the median diameter of the cellulose-containing raw material made 10μm-150 μm wherein bulk density of the cellulose powder mixture at the conclusion of step 1 is in the range of 100 to 750 kg/m 3 , and
Step 2 wherein water content in the cellulose powder mixture obtained in Step 1 is adjusted in the range of 30 to 100% by mass relative to the cellulose in the cellulose-containing raw material used in Step 1 by adding water to the cellulose powder mixture obtained in Step 1thereby obtaining an alkali cellulose in the powder form.

2. The method for producing the alkali cellulose according to claim 1 , further comprising a Step 3 wherein, after addition of water in Step 2, aging is carried out by increasing the temperature to 35 to 90° C. for the time period of 0.1 to 24 hours.

3. The method for producing the alkali cellulose according to claim 1 , wherein the water content in the cellulose-containing raw material in Step 1 is in the range of 0.01-7% by mass relative to the cellulose.

4. The method for producing the alkali cellulose according to claim 1 , wherein the basic compound is an alkaline metal hydroxide.

5. The method for producing the alkali cellulose according to claim 1 , wherein a pulverizing machine used in Step 1 is a vessel-driven medium mill or a medium-stirring mill.

6. A method for producing a cellulose ether, further comprising the step wherein the alkali cellulose produced by the production method according to claim 1 is reacted with an etherification agent.

7. The method for producing the cellulose ether according to claim 6 , wherein the alkali cellulose and the etherification agent are reacted in the presence of a non-aqueous solvent with the amount thereof being in the range of 1 to 100% by mass relative to the cellulose in the cellulose-containing raw material.

8. The method for producing the cellulose ether according to claim 6 , wherein the etherification agent is one or more kinds selected from the group consisting of ethylene oxide, propylene oxide, glycidol, chloroacetic acid, sodium chloroacetate salt, glycidyl trimethyl ammonium chloride salt, and 1-chloro-2-hydroxypropane-3-trimethyl ammonium chloride salt.

9. A method for producing a cellulose ether, futher comprising:
reacting the alkali cellulose produced by the production method according to claim 1 with an etherification agent,
wherein the amount of the etherification agent is in the range of 0.001 to 50 mol relative to total 1 mol of the anhydroglucose unit of the cellulose and of the anhydroglucose unit of the alkali cellulose in the alkali cellulose-containing mixture produced by the production method according to claim 1 .

10. The method for producing the cellulose ether according to claim 7 , wherein the non-aqueous solvent is selected from the group consisting of a secondary or a tertiary lower alcohol having 3 to 4 carbon atoms, a ketone having 3 to 6 carbon atoms, an ether, a non-protonic polar solvent and mixtures thereof.

11. The method for producing the alkali cellulose according to claim 1 , wherein the average degree of polymerization of the cellulose in the cellulose-containing raw material in Step 1 is 100 to 10000.

12. The method for producing the alkali cellulose according to claim 1 , wherein the crystallinity of the cellulose in the cellulose-containing raw material in Step 1 is 10% to 95%.

13. The method for producing the alkali cellulose according to claim 1 , wherein the median diameter of the cellulose-containing raw material after pulverization in Step 1 is 20 μm-150 μm.

14. The method for producing the alkali cellulose according to claim 1 , wherein amount of water during pulverization in Step 1 is 0.1-7% by mass.

Assignees

• Miyoshi Eisuke
• Yoshida Yutaka
• Miyasato Ryo
• Shiba Kenichi
• Takahashi Rui
• Imori Yoichiro
• Kao Corp

Inventors

• Miyoshi Eisuke
• Yoshida Yutaka
• Miyasato Ryo
• Shiba Kenichi
• Takahashi Rui
• Imori Yoichiro

Classifications

• C08B11/08

  with hydroxylated hydrocarbon radicals; Esters, ethers, or acetals thereof · CPC title

• C08B1/08 Primary

  Alkali cellulose · CPC title

• C08B1/06

  Rendering cellulose suitable for etherification {(etherification per se C08B11/00)} · CPC title

• C08B15/00 Primary

  Preparation of other cellulose derivatives or modified cellulose {, e.g. complexes} · CPC title

• C08L1/26

  Cellulose ethers · CPC title