Dissolution of oxidized cellulose

Patent metadata

Field	Value
Publication number	US-2017066846-A1
Application number	US-201615353997-A
Country	US
Kind code	A1
Filing date	Nov 17, 2016
Priority date	Jun 29, 2011
Publication date	Mar 9, 2017
Grant date	—

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

1 - 20 . (canceled)

21 . 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.

22 . The process according to claim 21 , wherein the first temperature is adjusted to a temperature of from about 115° C. to about 145° C.

23 . The process according to claim 21 , wherein the first temperature is adjusted to a temperature of from about 120° C. to about 140° C.

24 . The process according to claim 21 , wherein the first temperature is adjusted to a temperature of from about 130° C. to about 135° C.

25 . The process according to claim 21 , wherein the second temperature is adjusted to a temperature of from about 90° C. to about 120° C.

26 . The process according to claim 21 , wherein the second temperature is adjusted to a temperature of from about 100° C. to about 110° C.

27 . The process according to claim 21 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.

28 . The process according to claim 21 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.

29 . The process according to claim 21 , 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.

30 . The process according to claim 21 , 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.

31 . 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.

32 . The process according to claim 31 , 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.

33 . The process according to claim 31 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.

34 . The process according to claim 31 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.

35 . The process according to claim 31 , wherein the salt is present in an amount of from about 0.1% by weight to about 3% by weight of the oxidized cellulose.

36 . 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.

37 . The process according to claim 36 , 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.

38 . The process according to claim 36 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.

39 . The process according to claim 36 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.

40 . The process according to claim 36 , 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

• C08B16/00 Primary

  Regeneration of cellulose · CPC title

• C08J3/096

  Nitrogen containing compounds · CPC title

• C08J2301/02

  Cellulose; Modified cellulose · CPC title

• C08K5/20

  Carboxylic acid amides · CPC title