Process for producing a crosslinked cellulose ether

Patent metadata

Field	Value
Publication number	US-12312420-B2
Application number	US-202017428774-A
Country	US
Kind code	B2
Filing date	Apr 17, 2020
Priority date	May 1, 2019
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

A process for producing a crosslinked cellulose ether including contacting an activated cellulose material with (i) an aqueous crosslinking agent emulsion, wherein the aqueous crosslinking agent emulsion is a mixture of (ia) at least one crosslinking agent; (ib) water; and (ic) any other optional components desired; and (ii) at least one etherification reagent; wherein the aqueous crosslinking agent emulsion (i) and the at least one etherification reagent (ii) react with the activated cellulose material to form the crosslinked cellulose ether; and a crosslinked cellulose ether produced by the above process.

First claim

What is claimed is:

1. A process for producing a crosslinked cellulose ether comprising contacting an activated cellulose material with (i) an aqueous crosslinking agent emulsion comprising (ia) at least one crosslinking agent and (ib) water; and (ii) at least one etherification reagent; wherein the aqueous crosslinking agent emulsion and the at least one etherification reagent form a reaction mixture which reacts with the activated cellulose material to form the crosslinked cellulose ether;
wherein the at least one crosslinking agent is a diglycidyl ether type crosslinking agent having the following chemical Structure (I):

wherein n is selected from 3 to 25; and wherein the crosslinked cellulose ether is a water soluble crosslinked cellulose ether.

2. The process of claim 1 , wherein the process includes the steps of:
(A) mixing (ia) at least one crosslinking agent with (ib) water to form an the aqueous crosslinking agent emulsion; and
(B) contacting the activated cellulose material with (Bi) the aqueous crosslinking agent emulsion of step (A) and Bii) at least one etherification reagent; wherein the aqueous crosslinking agent emulsion and the at least one etherification reagent form the reaction mixture which reacts with the activated cellulose material to form the crosslinked cellulose ether.

3. The process of claim 1 , further including one or more steps of purifying, washing, drying, granulating, and milling the crosslinked cellulose ether.

4. The process of claim 1 , wherein the crosslinked cellulose ether forms at a pressure of greater than or equal to 1,000 kilopascals and at a temperature of greater than 70° C.

5. The process of claim 1 , wherein the activated cellulose material is formed by contacting at least one cellulose material with at least one alkalization reagent.

6. The process of claim 5 , wherein the at least one cellulose material is selected from the group consisting of wood pulp, cotton linters, and mixtures thereof; and wherein the at least one alkalization reagent is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, and mixtures thereof in a solution.

7. The process of claim 5 , wherein the concentration of the at least one alkalization reagent is from 1 mole of sodium hydroxide per mole of anhydroglucose units of the cellulose material to 3.5 moles of sodium hydroxide per moles of anhydroglucose units of the cellulose material to form the activated cellulose material.

8. The process of claim 5 , further including a step of grinding the at least one cellulose material to form a ground cellulose flock material; and
wherein the grinding step is carried out prior to mixing the cellulose material with the alkalization reagent.

9. The process of claim 1 , wherein the at least one etherification reagent is selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide, methyl chloride, ethyl chloride, and mixtures thereof.

10. The process of claim 1 , wherein the contacting is carried out in an inert atmosphere.

11. The process of claim 1 , wherein the amount of crosslinking agent in the aqueous crosslinking agent emulsion is from 10 weight percent to 90 weight percent based on the total weight of the crosslinking agent and water.

12. The process of claim 1 , wherein the aqueous crosslinking agent emulsion is present at a concentration of from 0.0001 mole of the crosslinking agent per mole of anhydroglucose units of the cellulose ether to 0.05 mole of the crosslinking agent per mole of anhydroglucose units of the cellulose ether; and wherein the etherification reagent is present at a concentration of from 4 moles of the etherification reagent per moles of anhydroglucose units of the cellulose ether to 6 moles of the etherification reagent per moles of anhydroglucose units of the cellulose ether.

13. The process of claim 2 , further including further one or more steps of purifying, washing, drying, granulating, and milling the crosslinked cellulose ether.

Assignees

• Dow Global Technologies Llc

Inventors

• Hild Alexandra
• Neubauer Jöerg
• Schmidt Steffen
• Baumann Robert

Classifications

• C08J2301/28

  Alkyl ethers · CPC title

• C08J3/24

  Crosslinking, e.g. vulcanising, of macromolecules (mechanical aspects B29C35/00; crosslinking agents C08K) · CPC title

• C08B15/00

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

• C08B11/08

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

• C08B11/02 Primary

  Alkyl or cycloalkyl ethers · CPC title