	US 11,939,405 B2
	Method of pulping cotton-based raw material
Stephan Silbermann, Gampern (AT); and Christian Weilach, Vöcklabruck (AT)
Assigned to Lenzing AG, Lenzing (AT)
Appl. No. 16/472,482
Filed by LENZING AKTIENGESELLSCHAFT, Lenzing (AT)
PCT Filed Dec. 22, 2017, PCT No. PCT/EP2017/084357 § 371(c)(1), (2) Date Jun. 21, 2019, PCT Pub. No. WO2018/115428, PCT Pub. Date Jun. 28, 2018.
Claims priority of application No. 16206392 (EP), filed on Dec. 22, 2016.
Prior Publication US 2021/0130501 A1, May 6, 2021
Int. Cl. C08B 16/00 (2006.01); C08B 9/00 (2006.01); C08K 3/30 (2006.01); C08K 5/17 (2006.01); D01F 2/00 (2006.01); D01F 2/06 (2006.01)

CPC C08B 16/00 (2013.01) [C08B 9/00 (2013.01); C08K 3/30 (2013.01); C08K 5/175 (2013.01); D01F 2/00 (2013.01); D01F 2/06 (2013.01); C08K 2003/3063 (2013.01)]

14 Claims

1. A method of pulping a cotton-based raw material for producing dissolving pulp, said method comprising:

a. an incubation step for generating the dissolving pulp by incubating the cotton-based raw material with an alkaline solution in combination with a gaseous oxidizing agent in a pressurized vessel

i. at a temperature of about 90-about 185° C.,

ii. for an incubation time of about 45-about 270 min,

iii. in the presence of a cellulose-stabilizing additive,

iv. at a concentration of alkali of about 1-about 35% (w/w) of the cotton-based raw material, and

v. at an initial gas pressure of about 1-about 21 bar (about 0.1 MPa-about 2.1 MPa), thereby generating the dissolving pulp; and

b. a step of washing the dissolving pulp,

wherein the cotton-based raw material is a pre- or post-consumer material,

wherein step a. is the only step for generating the dissolving pulp.