US 12,404,360 B2
Method of preparing graft copolymer
Tae Young Jeon, Daejeon (KR); Joo Byung Chai, Daejeon (KR); Yu Sung Jung, Daejeon (KR); Jong Beom Kim, Daejeon (KR); and Eun Seon Park, Daejeon (KR)
Assigned to LG CHEM, LTD.
Appl. No. 17/435,637
Filed by LG CHEM, LTD., Seoul (KR)
PCT Filed Jul. 21, 2020, PCT No. PCT/KR2020/009573
§ 371(c)(1), (2) Date Sep. 1, 2021,
PCT Pub. No. WO2021/015526, PCT Pub. Date Jan. 28, 2021.
Claims priority of application No. 10-2019-0089775 (KR), filed on Jul. 24, 2019; and application No. 10-2020-0089664 (KR), filed on Jul. 20, 2020.
Prior Publication US 2022/0153899 A1, May 19, 2022
Int. Cl. C08F 279/04 (2006.01); C08F 279/02 (2006.01); C08L 55/02 (2006.01)
CPC C08F 279/04 (2013.01) [C08F 279/02 (2013.01); C08L 55/02 (2013.01)] 8 Claims
 
1. A method of preparing a graft copolymer, comprising:
initiating graft emulsion polymerization by primarily adding a diene-based rubber polymer, an aromatic vinyl-based monomer, a vinyl cyanide-based monomer and an azo initiator to a reactor; and
performing graft emulsion polymerization by continuously secondarily adding the aromatic vinyl-based monomer, the vinyl cyanide-based monomer, and the azo initiator to the reactor;
wherein the azo initiator has a solubility in water at 20° C. of 10 g/100 g or more and a 10-hour half-life decomposition temperature in water of 80° C. or less,
wherein the graft emulsion polymerization is initiated at 45 to 55° C.,
wherein the diene-based rubber polymer is formed of a conjugated diene-based monomer, and the conjugated diene-based monomer is one or more selected from the group consisting of 1,3-butadiene, isoprene, chloroprene, and piperylene,
wherein the aromatic vinyl-based monomer is one or more selected from the group consisting of styrene, α-methylstyrene, α-ethylstyrene, and p-methylstyrene,
wherein the vinyl cyanide-based monomer is one or more selected from the group consisting of acrylonitrile, methacrylonitrile, phenylacrylonitrile, and α-chloroacrylonitrile.