US 12,404,230 B2
Method for preparing a recycled material using waste copolyester and recycled material composition
Ji-Hun Kim, Seongnam-si (KR); Kwang-Woo Park, Seongnam-si (KR); and Joong Ki Lee, Seongnam-si (KR)
Assigned to SK CHEMICALS CO., LTD., Seongnam-si (KR)
Appl. No. 18/696,668
Filed by SK CHEMICALS CO., LTD., Seongnam-si (KR)
PCT Filed Dec. 7, 2023, PCT No. PCT/KR2023/020045
§ 371(c)(1), (2) Date Mar. 28, 2024,
PCT Pub. No. WO2024/154943, PCT Pub. Date Jul. 25, 2024.
Claims priority of application No. 10-2023-0009078 (KR), filed on Jan. 20, 2023.
Prior Publication US 2025/0034075 A1, Jan. 30, 2025
Int. Cl. C07C 67/54 (2006.01); C07C 67/02 (2006.01); C07C 69/82 (2006.01); C08J 11/24 (2006.01)
CPC C07C 67/54 (2013.01) [C07C 67/02 (2013.01); C07C 69/82 (2013.01); C08J 11/24 (2013.01); C08J 2367/02 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for preparing a recycled raw material, which comprises:
(1) depolymerizing a waste copolyester to obtain a first reactant;
(2) removing impurities present in the first reactant to obtain a second reactant;
(3) distilling the second reactant to obtain a third reactant comprising crude recycled bis-2-hydroxyethyl terephthalate and a fourth reactant comprising a recycled diol-ester; and
(4) mixing the third reactant with an aqueous solvent and recrystallizing it to obtain a fifth reactant comprising recycled bis-2-hydroxyethyl terephthalate and a filtrate.