US 12,146,008 B2
Modified chitosan, preparation method thereof, and additive for tile adhesive and use thereof
Kun Teng, Tai'an (CN); Ming Zhao, Tai'an (CN); Bo Teng, Tai'an (CN); and Qinghua Li, Tai'an (CN)
Assigned to SHANDONG ETON NEW MATERIAL CO., LTD., Tai'an (CN)
Filed by SHANDONG ETON NEW MATERIAL CO., LTD., Tai'an (CN)
Filed on Oct. 8, 2021, as Appl. No. 17/450,376.
Claims priority of application No. 202011076111.2 (CN), filed on Oct. 10, 2020.
Prior Publication US 2022/0112312 A1, Apr. 14, 2022
Int. Cl. C08B 37/00 (2006.01); C08B 37/08 (2006.01); C09J 101/26 (2006.01)
CPC C08B 37/003 (2013.01) [C09J 101/26 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for preparing a modified chitosan, comprising
mixing a chitosan, an inorganic base, and a dispersant having a hydroxyl group, adding an etherifying agent thereto, and subjecting the resulting mixture to an etherification reaction to obtain the modified chitosan,
wherein the etherification reaction comprises a first etherification reaction, a second etherification reaction, and a third etherification reaction;
wherein the first etherification reaction is performed at a temperature of 20-35° C. and a pressure of 0.05-0.1 MPa for 2.5-3.5 h;
wherein the second etherification reaction is performed at a temperature of 40-50° C. and a pressure of 0.11-0.18 MPa for 2.0-3.0 h; and
wherein the third etherification reaction is performed at a temperature of 55-65° C. and a pressure of 0.21-0.28 MPa for 2.0-3.0 h.