US 11,702,487 B2
Process for preparing propylene polymers
Noureddine Ajellal, Porvoo (FI); and Ville Virkkunen, Porvoo (FI)
Assigned to BOREALIS AG, Vienna (AT)
Appl. No. 17/49,989
Filed by BOREALIS AG, Vienna (AT)
PCT Filed May 7, 2019, PCT No. PCT/EP2019/061633
§ 371(c)(1), (2) Date Oct. 23, 2020,
PCT Pub. No. WO2019/215120, PCT Pub. Date Nov. 14, 2019.
Claims priority of application No. 18171547 (EP), filed on May 9, 2018.
Prior Publication US 2021/0230319 A1, Jul. 29, 2021
Int. Cl. C08F 210/16 (2006.01); C08F 4/64 (2006.01); C08F 10/06 (2006.01); C08F 4/642 (2006.01)
CPC C08F 10/06 (2013.01) [C08F 4/64003 (2013.01); C08F 4/6428 (2013.01); C08F 210/16 (2013.01); C08F 2420/07 (2021.01); C08F 2500/03 (2013.01); C08F 2500/12 (2013.01); C08F 2500/17 (2013.01); C08F 2500/18 (2013.01); C08L 2207/02 (2013.01)] 13 Claims
 
1. A process for polymerizing propylene monomers together with ethylene comonomers, the process comprising:
polymerizing propylene monomers together with ethylene comonomers in the presence of a single-site catalyst comprising:
(i) a complex of formula (I):

OG Complex Work Unit Chemistry
wherein,
M is zirconium or hafnium;
each X independently is a sigma-donor ligand,
L is a divalent bridge selected from —R′2C—, —R′2C—CR′2—, —R′2Si—, —R′2Si—SiR′2—, —R′2Ge—, wherein each R′ is independently a hydrogen atom or a C1-C20-hydrocarbyl group optionally containing fluorine atoms, or optionally two R′ groups taken together can form a ring;
R1 and R1′ are each independently hydrogen, C5-C10-aryl or a group —CH(Rx)2 wherein each Rx is independently H or a C1-C10 hydrocarbyl group, and optionally the two Rx taken together can form a ring,
R2 and R2′ are each independently hydrogen, C5-C10-aryl or a group —C(Ry)3 wherein each Ry is independently H or a C1-10 hydrocarbyl group, or optionally two or three Ry groups taken together can form a ring,
whereby at least one of R1 or R2 and one of R1′ or R2′ is different from hydrogen, and
whereby R2 together with one of R1, as well as R2′ together with one of R1′ can be part of a further mono- or multicyclic ring condensed to the phenyl ring,
R3 and R3′ are each independently a linear C1 to C6 hydrocarbyl group or a branched or cyclic C4 to C10 hydrocarbyl group, whereby the groups are not branched in α-position,
R4 and R4′ are each independently a tertiary C4 to C10 hydrocarbyl group,
R5 and R5′ are each independently a linear or branched C1 to C10 alkyl group or an C5-C10-aryl group, and
(ii) a cocatalyst system comprising a boron containing cocatalyst and an aluminoxane cocatalyst,
wherein the process is a multistage process comprising at least two reactors connected in series including at least one gas phase polymerization step.