US 11,787,892 B2
Process for making an oxymethylene polymer
Thomas Heitz, Ludwigshafen am Rhein (DE); Minlu Zhang, Ludwigshafen am Rhein (DE); Achim Stammer, Ludwigshafen am Rhein (DE); JongMoon Kim, Gimcheon (KR); In-Gi Cho, Gimcheon (KR); and Jin-Sang Choi, Gimcheon (KR)
Assigned to BASF SE; and Kolon Plastics Inc.
Appl. No. 16/478,703
Filed by BASF SE, Ludwigshafen am Rhein (DE); and Kolon Plastics Inc., Gwacheon-Si (KR)
PCT Filed Jan. 9, 2018, PCT No. PCT/EP2018/050395
§ 371(c)(1), (2) Date Jul. 17, 2019,
PCT Pub. No. WO2018/134075, PCT Pub. Date Jul. 26, 2018.
Claims priority of application No. 17152101 (EP), filed on Jan. 19, 2017.
Prior Publication US 2020/0048395 A1, Feb. 13, 2020
Int. Cl. C08G 2/10 (2006.01); B01J 27/12 (2006.01); C08G 2/06 (2006.01)
CPC C08G 2/10 (2013.01) [B01J 27/12 (2013.01); C08G 2/06 (2013.01)] 9 Claims
 
1. A process for making an oxymethylene polymer comprising polymerizing at least one compound capable of forming —CH2O— repeat units (monomer) and at least one comonomer which is a cyclic ether or cyclic formal in the presence of at least one ester of the formula I (ester)
R1—CO—O—R2   (I)
wherein
R1 can be hydrogen, with the proviso that R2 is C2 alkyl or linear C3 to C4 alkyl,
wherein R1 and R2 are independently of each other
linear or branched C1 to C4 alkyl
and in the presence of at least one Lewis acid, wherein the Lewis acid is an halogenide of boron, tin, titanium, phosphorus, antimony or arsenic, wherein the at least one Lewis acid is premixed with the at least one ester (premixture) and the weight ratio of the at least one ester to the at least one Lewis acid being of from 10:1 to 300:1.