Carboxymethylated cellulose

Patent metadata

Field	Value
Publication number	US-11760811-B2
Application number	US-201816768945-A
Country	US
Kind code	B2
Filing date	Dec 5, 2018
Priority date	Dec 7, 2017
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

A carboxymethylated cellulose having a carboxymethyl substitution of no more than 0.50 and a cellulose I type crystallization of at least 50%. Ideally, the anionization is 0.00-1.00 meq/g. The Schopper-Riegler freeness is ideally at least 60.0° SR. Ideally the ratio of filtration residue is 0%-30% by mass. The viscosity (30 rpm, 25° C.) for an aqueous dispersion having a 1% solid content (w/v) is ideally no more than 10.0 mPa·s.

First claim

The invention claimed is:

1. A carboxymethylated cellulose having a degree of carboxymethyl substitution of 0.50 or less, a degree of crystallization of cellulose I type of 50% or more, and a portion of a filter cake being 0 to 30%, wherein the portion of the filter cake is determined by a method comprising the steps of:
adding 5 g of the carboxymethylated cellulose to 500 g of water to obtain a mixture,
stirring the mixture at 400 rpm for 5 seconds,
subjecting the stirred mixture to natural filtration through a 20-mesh filter to obtain the filter cake on the filter,
drying the filter cake on the filter at 100° C. for 2 hours,
determining an absolute dry mass (g) of the filter cake,
determining an amount of moisture (%) in the carboxymethylated cellulose, and
calculating the proportion of the filter cake by using the following expression:
proportion (%) of filter cake=[the absolute dry mass (g) of filter cake/{5 (g)×(100−the amount of moisture (%) in the carboxymethylated cellulose)/100}]×100.

2. The carboxymethylated cellulose according to claim 1 , having a degree of anionization of 0.00 meq/g or more and 1.00 meq/g or less.

3. The carboxymethylated cellulose according to claim 2 , having a structure wherein some of hydroxyl groups in glucose residues constituting cellulose are linked to carboxymethyl groups via ether linkages.

4. The carboxymethylated cellulose according to claim 1 , having a Schopper-Riegler freeness of 60.0° SR or more.

5. The carboxymethylated cellulose according to claim 4 , having a Canadian standard freeness of 150 ml or less.

6. The carboxymethylated cellulose according to claim 5 , having a structure wherein some of hydroxyl groups in glucose residues constituting cellulose are linked to carboxymethyl groups via ether linkages.

7. The carboxymethylated cellulose according to claim 4 , having a structure wherein some of hydroxyl groups in glucose residues constituting cellulose are linked to carboxymethyl groups via ether linkages.

8. The carboxymethylated cellulose according to claim 1 , wherein when the carboxymethylated cellulose is dispersed in water to form a water dispersion having a solid content of 1% (w/v), the water dispersion has a viscosity (30 rpm, 25° C.) of 10.0 mPa·s or less.

9. The carboxymethylated cellulose according to claim 8 , having a structure wherein some of hydroxyl groups in glucose residues constituting cellulose are linked to carboxymethyl groups via ether linkages.

10. The carboxymethylated cellulose according to claim 1 , having a structure wherein some of hydroxyl groups in glucose residues constituting cellulose are linked to carboxymethyl groups via ether linkages.

11. The carboxymethylated cellulose according to claim 1 , wherein the portion of a filter cake is 0 to 20%.

Assignees

• Jujo Paper Co Ltd

Inventors

• Inoue Kazuhiko
• Nakatani Takeshi
• Tada Yusuke
• Nishigaya Kasumi
• Suzuki Hiroyoshi

Classifications

• C08L1/286 Primary

  substituted with acid radicals, e.g. carboxymethyl cellulose [CMC] (C08L1/282 takes precedence) · CPC title

• C08B11/12 Primary

  substituted with carboxylic radicals {, e.g. carboxymethylcellulose [CMC]} · CPC title

• C08B1/08

  Alkali cellulose · CPC title

• C08H8/00

  Macromolecular compounds derived from lignocellulosic materials {(pretreatment thereof B27N)} · CPC title

• D21C9/005

  organic compounds · CPC title