Cellulose suspension, method for the production and use thereof

Patent metadata

Field	Value
Publication number	US-2016237171-A1
Application number	US-201415027937-A
Country	US
Kind code	A1
Filing date	Nov 14, 2014
Priority date	Oct 15, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

The present invention relates to a phase-stable suspension of cellulose II in water, having a high water retention capacity and a cellulose concentration between 0.1 and 5.0% by weight, a method of its preparation, and its use.

First claim

1 . A phase-stable suspension of cellulose II in water, having a high water retention capacity, wherein said suspension has a cellulose concentration between 0.1 and 5.0% by weight and wherein the viscosity (in [Pa*s] at a shear rate of 50 s −1 ) and the water retention capacity (in %) as a function of the cellulose concentration x (in % by weight, related to the total quantity of the suspension) of said suspension have the following relationship:
(viscosity at 50 s−1/WRC)*10000<0.4038* x 2.8132

2 . The suspension as claimed in claim 1 , wherein the property range of the suspension is also limited by the relationship:
(viscosity at 50 s−1/WRC)*10000>0.0201* x 2.366

3 . The suspension as claimed in claim 1 , wherein the viscosity and the water retention capacity as a function of the cellulose concentration x have the following relationship:
(viscosity at 50 s−1/WRC)*10000<0.3057* x 2.5698

4 . The suspension as claimed in claim 1 , wherein the WRC is between 500 and 5000%.

5 . A method for preparing a phase-stable suspension of cellulose II in water, having a high water retention capacity, comprising the following steps:
a. preparing a spinning dope with 10 to 15% by weight of cellulose according to the lyocell process, b. precipitating the cellulose, whereby a material containing NMMO and cellulose is obtained, c. washing the material until it is substantially NMMO-free, d. enzymatic treatment of the moist material which has been washed substantially free of NMMO, e. comminution in a comminution unit, whereby a coarse cellulose suspension is obtained, and f. microcomminution in a high pressure homogenizer into a stable microsuspension.

6 . The method as claimed in claim 5 , wherein an endoglucanase or a mixture of endoglucanases and exoglucanases is used as the enzyme in step d.

7 . The method as claimed in claim 5 , wherein the enzyme concentration in step d. is 0.1 to 10.0% by weight, related to the cellulose quantity.

8 . The method as claimed in claim 5 , wherein the pressure in the high pressure homogenizer in step f. is between 100 and 2000 bar.

9 . The method as claimed in claim 5 , wherein in step f. the suspension is passed between 1 and 10 times, through the high pressure homogenizer.

10 . The method as claimed in claim 5 , wherein in step a. the cellulose concentration is 12 to 14% by weight.

11 . Use of the suspension as claimed in claim 1 for the preparation of cellulose particles having a cellulose II structure, a spherical shape, and an average diameter x 50 from 1 to 4 μm by spray drying.

12 . The suspension as claimed in claim 4 , wherein the WRC is between 1000 and 4000%.

13 . The method as claimed in claim 9 , wherein in step f. the suspension is passed between 1 and 4 times through the high pressure homogenizer.

Assignees

• Chemiefaser Lenzing Ag

Inventors

• Männer Johann
• Opietnik Martina
• Innerlohinger Josef
• Reiter Gerhard
• Hager Markus

Classifications

• C08L1/02 Primary

  Cellulose; Modified cellulose · CPC title

• C08J2301/02

  Cellulose; Modified cellulose · CPC title

• C08J3/075 Primary

  Macromolecular gels · CPC title

• C08B1/003 Primary

  Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids (solutions used in the manufacture of monocomponent artificial filaments or cellulose or derivatives thereof D01F2/02) · CPC title

• D21C5/005

  Treatment of cellulose-containing material with microorganisms or enzymes · CPC title