US 12,234,351 B2
Random propylene polymer composition and use in extrusion blow moulding
Jingbo Wang, Linz (AT); Markus Gahleitner, Linz (AT); Friedrich Berger, Linz (AT); and Karlheinz Friedrich, Schwechat (AT)
Assigned to BOREALIS AG, Vienna (AT)
Appl. No. 17/423,407
Filed by BOREALIS AG, Vienna (AT)
PCT Filed Jan. 15, 2020, PCT No. PCT/EP2020/050883
§ 371(c)(1), (2) Date Jul. 15, 2021,
PCT Pub. No. WO2020/148319, PCT Pub. Date Jul. 23, 2020.
Claims priority of application No. 19151936 (EP), filed on Jan. 15, 2019.
Prior Publication US 2022/0073718 A1, Mar. 10, 2022
Int. Cl. C08L 23/14 (2006.01); B29C 49/04 (2006.01); C08F 2/00 (2006.01); C08F 4/646 (2006.01); C08F 4/649 (2006.01); C08F 4/654 (2006.01); C08F 210/02 (2006.01); C08F 210/14 (2006.01); B29K 23/00 (2006.01); B29L 31/00 (2006.01)
CPC C08L 23/142 (2013.01) [B29C 49/04 (2013.01); C08F 2/001 (2013.01); C08F 4/6465 (2013.01); C08F 4/6492 (2013.01); C08F 4/6545 (2013.01); C08F 4/6548 (2013.01); C08F 210/02 (2013.01); C08F 210/14 (2013.01); B29K 2023/14 (2013.01); B29L 2031/7158 (2013.01); C08L 2205/025 (2013.01); C08L 2205/06 (2013.01); C08L 2205/24 (2013.01); C08L 2308/00 (2013.01); C08L 2314/02 (2013.01)] 14 Claims
 
1. A propylene polymer composition comprising at least one propylene copolymer (C-PP), and an α-nucleating agent (N), wherein the propylene copolymer (C-PP) comprises two propylene copolymer fractions (PP1) and (PP2), wherein
propylene copolymer fraction (PP1) is contained in the propylene copolymer (C-PP) in an amount of 30 to 70 wt. % and the propylene copolymer fraction (PP2) is contained in the propylene copolymer (C-PP) in an amount of 70 to 30 wt. %,
the comonomer content of propylene copolymer fraction (PP1) is in the range of 0.5 to 2.6 wt.-% and the comonomer content of the propylene copolymer fraction (PP1) is lower compared to the comonomer content of the propylene copolymer fraction (PP2), and the propylene polymer composition has
(a) a melt flow rate MFR2 (230° C.) measured according to according to ISO 1133 of 1 to 5 g/10 min.,
(b) a comonomer content of 4.0 to 8.0 wt. %, the comonomer(s) being ethylene and/or at least one C4 to C12 α-olefin, and
(c) a soluble fraction (SF), determined by CRYSTEC fractionation with CRYSTEX QC, Polymer Char (Valencia, Spain), of from 8 to 20 wt. %,
wherein propylene copolymer (C-PP) is obtained in a multi-stage polymerization process in the presence of
(a) a Ziegler-Natta catalyst (ZN-C) that comprises a titanium compound (TC), a magnesium compound (MC) and an internal donor (ID), wherein said internal donor (ID) is a non-phthalic acid ester,
(b) optionally a co-catalyst (Co), and
(c) optionally an external donor (ED),
wherein the ratio C2(SF)/C2(CF) between the ethylene content C2(SF) of soluble fraction of the propylene copolymer (C-PP) and the ethylene content C2(CF) of crystalline fraction of the propylene copolymer (C-PP) is 4.0 to 6.0.