Dissolution of oxidized cellulose

Patent metadata

Field	Value
Publication number	US-10982012-B2
Application number	US-201615353997-A
Country	US
Kind code	B2
Filing date	Nov 17, 2016
Priority date	Jun 29, 2011
Publication date	Apr 20, 2021
Grant date	Apr 20, 2021

Abstract

A process for dissolving modified cellulose is disclosed. The process includes contacting modified cellulose with a solvent in a mixture to form swelled modified cellulose and then contacting the mixture with a salt to dissolve the swelled modified cellulose.

First claim

What is claimed is:

1. A process comprising:
forming a mixture by contacting an oxidized cellulose with a solvent under an inert atmosphere to form a swelled oxidized cellulose;
adjusting the mixture to a first temperature;
contacting the swelled oxidized cellulose with a salt under the inert atmosphere to form an oxidized cellulose solution; and
adjusting the oxidized cellulose solution to a second temperature lower than the first temperature.

2. The process according to claim 1 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.

3. The process according to claim 1 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.

4. The process according to claim 1 , wherein the oxidized cellulose solution includes dissolved oxidized cellulose having a degree of oxidation from about 80% to about 120% of a degree of oxidation of the oxidized cellulose prior to dissolution.

5. The process according to claim 1 , wherein oxidized cellulose solution includes dissolved oxidized cellulose having a molecular weight from about 80% to about 120% of a molecular weight of the oxidized cellulose prior to dissolution.

6. A process comprising:
forming a mixture by contacting an oxidized cellulose with a solvent under an inert atmosphere to form a swelled oxidized cellulose, the oxidized cellulose having a degree of oxidation of from about 0.2 to about 1.0;
heating the mixture; and
contacting the swelled oxidized cellulose with a salt under the inert atmosphere to form an oxidized cellulose solution, wherein the dissolved oxidized cellulose has a degree of oxidation from about 80% to about 120% of the degree of oxidation of the oxidized cellulose prior to dissolution.

7. The process according to claim 6 , wherein heating the mixture includes adjusting the mixture to a first temperature and the process further comprises subsequently adjusting the mixture to a second temperature lower than the first temperature.

8. The process according to claim 6 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.

9. The process according to claim 6 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.

10. The process according to claim 6 , wherein the salt is present in an amount of from about 0.1% by weight to about 3% by weight of the oxidized cellulose.

11. A process comprising:
forming a mixture by contacting an oxidized cellulose with a solvent under an inert atmosphere to form a swelled oxidized cellulose;
heating the mixture; and
contacting the swelled oxidized cellulose with a salt under the inert atmosphere to form an oxidized cellulose solution under the inert atmosphere, wherein the dissolved oxidized cellulose has a molecular weight from about 80% to about 100% of the molecular weight of the oxidized cellulose prior to dissolution.

12. The process according to claim 11 , wherein heating the mixture includes adjusting the mixture to a first temperature and the process further comprises subsequently adjusting the mixture to a second temperature lower than the first temperature.

13. The process according to claim 11 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.

14. The process according to claim 11 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.

15. The process according to claim 11 , wherein the salt is present in an amount of from about 0.1% by weight to about 3% by weight of the oxidized cellulose.

Assignees

• Covidien Lp

Inventors

• Tramontano Valentino J
• Kennedy Joshua
• Farooqi Sajida
• Blaskovich Phillip D
• Ohri Rachit
• Costa Daniel S

Classifications

• C08J3/091 Primary

  characterised by the chemical constitution of the organic liquid · CPC title

• C08K3/16

  Halogen-containing compounds · CPC title

• A61K9/1652

  Polysaccharides, e.g. alginate, cellulose derivatives; Cyclodextrin (homeopathic globules A61K9/1623) · CPC title

• C08L1/04

  Oxycellulose; Hydrocellulose {, e.g. microcrystalline cellulose} · CPC title

• C08J2301/04

  Oxycellulose; Hydrocellulose · CPC title