	US 11,987,667 B1
	High-viscosity biodegradable aliphatic-aromatic polyester copolymer having excellent hydrolysis resistance and method of preparing the same
Do Young Kim, Daejeon (KR); Hyun Sik Yang, Seoul (KR); Yu Hyun Kim, Seoul (KR); Ki Yup Kim, Daejeon (KR); Joo Hyun Nam, Daejeon (KR); Chul Soon Moon, Daejeon (KR); Ji Hae Park, Daejeon (KR); Sung Won Lee, Daejeon (KR); Jun Haeng Lee, Daejeon (KR); and Ho Seung Lee, Daejeon (KR)
Assigned to SK Innovation Co., Ltd., Seoul (KR); and SK Geo Centric Co., Ltd., Seoul (KR)
Filed by SK Innovation Co., Ltd., Seoul (KR); SK Geo Centric Co., Ltd., Seoul (KR); and Kolon Industries, Inc., Seoul (KR)
Filed on Aug. 11, 2023, as Appl. No. 18/448,370.
Claims priority of application No. 10-2022-0164742 (KR), filed on Nov. 30, 2022.
Int. Cl. C08G 63/52 (2006.01); C08G 63/183 (2006.01); C08G 63/78 (2006.01)

CPC C08G 63/183 (2013.01) [C08G 63/52 (2013.01); C08G 63/785 (2013.01); C08G 2230/00 (2013.01)]

19 Claims

1. A method of preparing a biodegradable aliphatic-aromatic polyester copolymer, the method comprising:

(S1) adding an aliphatic-aromatic polyester pre-copolymer to a reactor;

(S2) adding a chain extender to the reactor comprising the aliphatic-aromatic polyester pre-copolymer to prepare a chain extended aliphatic-aromatic polyester pre-copolymer by a first polyaddition reaction of the aliphatic-aromatic polyester pre-copolymer and the chain extender; and

(S3) adding an anti-hydrolysis agent to the reactor comprising the chain extended aliphatic-aromatic polyester pre-copolymer to prepare the biodegradable aliphatic-aromatic polyester copolymer by a second reaction of the chain extended aliphatic-aromatic polyester pre-copolymer and the anti-hydrolysis agent.