	US 12,252,562 B2
	Method for producing ethylene-acrylic acid copolymer
Sang Ha Son, Daejeon (KR); Wan Ju Jeong, Daejeon (KR); and Doh Yeon Park, 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); and SK Geo Centric Co., Ltd., Seoul (KR)
Filed on Mar. 15, 2022, as Appl. No. 17/695,102.
Claims priority of application No. 10-2021-0037948 (KR), filed on Mar. 24, 2021.
Prior Publication US 2022/0306778 A1, Sep. 29, 2022
Int. Cl. C08F 220/06 (2006.01); B29C 48/00 (2019.01); B29C 48/05 (2019.01); C08F 210/02 (2006.01); B29K 23/00 (2006.01); B29L 31/00 (2006.01)

CPC C08F 210/02 (2013.01) [B29C 48/022 (2019.02); B29C 48/05 (2019.02); B29K 2023/08 (2013.01); B29L 2031/731 (2013.01); C08F 2800/20 (2013.01)]

10 Claims

1. A method for producing an ethylene-acrylic acid copolymer comprising an anhydride structural unit, the method comprising:

a polymerization step of preparing an ethylene-acrylic acid copolymer by copolymerizing an ethylene monomer and an acrylic acid comonomer; and

a discharging step of discharging the ethylene-acrylic acid copolymer to obtain a strand;

wherein in the discharging step, a discharging temperature of the strand is controlled to be 275 to 280° C.;

the residence time of the strand is 5 to 60 seconds; and

wherein in the discharge step, carboxyl groups in the strand are dehydrated to form the anhydride structural unit.