Dissolution of oxidized cellulose

Patent metadata

Field	Value
Publication number	US-9522963-B2
Application number	US-201214129187-A
Country	US
Kind code	B2
Filing date	Jun 28, 2012
Priority date	Jun 29, 2011
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

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 from about 115° C. to 145° C.;
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 below the first temperature, the second temperature being from about 90° C. to about 120° C.

2. The process according to claim 1 , wherein the first temperature is from about 120° C. to about 140° C.

3. The process according to claim 1 , wherein the first temperature is from about 130° C. to about 135° C.

4. The process according to claim 1 , wherein the second temperature is from about 100° C. to about 110° C.

5. 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.

6. 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.

7. 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 predissolved oxidized cellulose.

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

9. 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;
adjusting the mixture to a first temperature from about 115° C. to 145° C.;
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 below the first temperature, the second temperature being from about 90° C. to about 120° C., wherein the dissolved oxidized cellulose has a degree of oxidation from about 80% to about 120% of the degree of oxidation of the predissolved oxidized cellulose.

10. The process according to claim 9 , wherein the first temperature is from about 120° C. to about 140° C.

11. The process according to claim 9 , wherein the second temperature is from about 100° C. to about 110° C.

12. The process according to claim 9 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.

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

14. The process according to claim 9 , wherein the salt is present in an amount of from about 0.1% by weight to 3% by weight of the oxidized cellulose.

15. 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 from about 115° C. to 145° C.;
contacting the swelled oxidized cellulose with a salt under the inert atmosphere to form an oxidized cellulose solution under the inert atmosphere; and
adjusting the oxidized cellulose solution to a second temperature below the first temperature, the second temperature being from about 90° C. to about 120° C., wherein the dissolved oxidized cellulose has a molecular weight from about 80% to about 100% of the molecular weight of the predissolved oxidized cellulose.

16. The process according to claim 15 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.

17. The process according to claim 15 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.

18. The process according to claim 15 , wherein the first temperature is from about 120° C. to about 140° C.

19. The process according to claim 15 , wherein the second temperature from about 100° C. to about 110° C.

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

Assignees

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

Inventors

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

Classifications

• C08J3/091 Primary

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

• C08K5/20

  Carboxylic acid amides · CPC title

• C08L1/04

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

• C08K3/16

  Halogen-containing compounds · CPC title

• C08B15/02 Primary

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