IP Library Granted Patent US 11,084,919
Granted Patent B2
US 11,084,919 · App. 16/310,036 · Granted Aug 10, 2021

Soft and transparent polypropylene composition

Inventors: Jingbo Wang (Engerwitzdorf, AT); Friedrich Berger (Linz, AT); Petar Doshev (Linz, AT); Manfred Gruenberger (Linz, AT); Martina Sandholzer (Linz, AT); Markus Gahleitner (Neuhofen/Krems, AT)
Assignee: BOREALIS AG
C08L23/12C08F210/16C08L23/16C08L2201/10C08L2203/16C08L2205/03C08L2207/02
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Quick Facts
Patent No.
US 11,084,919
App. No.
16/310,036
Granted
Aug 10, 2021
Kind
B2
Abstract

The present invention is directed to a polypropylene composition (C) comprising a heterophasic propylene copolymer (RAHECO) and a propylene homopolymer (H-PP) as well as a process for the preparation of said polypropylene composition and a film obtained from said polypropylene composition (C).

Claims (49)

1. A polypropylene composition (C), comprising:

a) a matrix (M) comprising a random propylene copolymer (R-PP) and a propylene homopolymer (H-PP) and

b) an elastomeric propylene copolymer (E) dispersed in said matrix (M),

wherein said polypropylene composition (C) has:

i) a xylene soluble content (XCS) with

a) an intrinsic viscosity (IV) determined according to DIN ISO 1628/1 (in Decalin at 135° C.) of the xylene soluble content (XCS) of at least 1.8 dl/g, and

b) an ethylene content of the xylene soluble content (C2 (XCS)) of at least 30.0 mol %, and

iii) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 of at least 2.0 g/10 min; and

wherein the random propylene copolymer (R-PP) and the elastomeric propylene copolymer (E) form a heterophasic propylene copolymer (RAHECO), said heterophasic propylene copolymer (RAHECO) having a xylene soluble content (XCS) in the range of 37.0 to 50.0 wt. % and a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 0.1 to 10.0 g/10 min.

2. The polypropylene composition (C) according to claim 1 , having a melting temperature Tm above 153° C.

3. The polypropylene composition (C) according to claim 1 , wherein the polypropylene composition (C) has:

i) a xylene soluble content (XCS) in the range of 10.0 to 45.0 wt. %, and/or

ii) an ethylene content in the range of 5.0 to 25.0 mol %, and/or

iii) a hexane soluble content in the range of 2.0 to below 16.0 wt. %.

4. The polypropylene composition (C) according to- claim 1 , wherein the ratio between the hexane soluble content C6 and the xylene soluble content XCS (C6/XCS) is below 0.45.

5. The polypropylene composition (C) according to claim 1 , wherein the polypropylene composition (C) has:

i) a haze before sterilization measured according to ASTM D 1300-00 on a 100 μm thick film below 20.0% and/or

ii) a haze after sterilization measured according to ASTM D 1300-00 on a 100 μm thick film below 12.0%.

6. The polypropylene composition (C) according to claim 1 , wherein the difference between the haze after sterilization and the haze before sterilization measured according to ASTM D 1300-00 on a 100 μm thick film is below 4.0%.

7. The polypropylene composition (C) according to claim 1 , comprising:

i) 75 to 95 wt. % of the matrix (M) and

ii) 5 to 25 wt. % of the elastomeric propylene copolymer (E),

based on the overall weight of the polypropylene composition (C), and/or

i) 30 to 75 wt. % of the random propylene copolymer (R-PP),

ii) 15 to 70 wt. % of the propylene homopolymer (H-PP) and

iii) 5 to 25 wt. % of the elastomeric propylene copolymer (E),

based on the overall weight of the polypropylene composition (C).

8. The polypropylene composition (C) according to claim 1 , wherein the comonomers of the random propylene copolymer (R-PP) and/or the comonomers of the elastomeric propylene copolymer (E) are ethylene and/or C 4 to C 8 α-olefins.

9. The polypropylene composition (C) according to claim 1 , wherein said heterophasic propylene copolymer (RAHECO) having

a) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 0.1 to 10.0 g/10 min, and/or

b) a comonomer content in the range of 5.0 to 35.0 mol % based on the amount of the heterophasic propylene copolymer (RAHECO).

10. The polypropylene composition (C) according to claim 1 , wherein the heterophasic propylene copolymer (RAHECO) comprises:

i) 60 to 90 wt. % of the random propylene copolymer (R-PP) and

ii) 10 to 40 wt. % of the elastomeric propylene copolymer (E),

based on the overall weight of the heterophasic propylene copolymer (RAHECO).

11. The polypropylene composition (C) according to claim 1 , wherein the propylene homopolymer (H-PP) has a melt flow rate MFR (230° C.) measured according to ISO 1133 in the range of 0.1 to 15.0 g/10 min.

12. Film, comprising the polypropylene composition (C) according to claim 1 .

13. A polymerization process for producing the polypropylene composition (C) according to claim 1 , comprising the steps of:

a) providing a propylene homopolymer (H-PP),

b) polymerizing in a first reactor (R1) propylene and ethylene and/or a C 4 to C 8 α-olefin, obtaining a first random propylene copolymer fraction (R-PP1),

c) transferring the first random propylene copolymer fraction (R-PP1) into a second reactor (R2),

d) polymerizing in said second reactor (R2) in the presence of the first random propylene copolymer fraction (R-PP1) propylene and ethylene and/or a C 4 to C 8 α-olefin, obtaining a second random copolymer fraction (R-PP2), said first random propylene copolymer fraction (R-PP1) and said second random copolymer fraction (R-PP2) forming the random propylene copolymer (R-PP),

e) transferring said random propylene copolymer (R-PP) into a third reactor (R3),

f) polymerizing in said third reactor (R3) in the presence of the random propylene copolymer (R-PP) propylene and/or a C 4 to C 8 α-olefin, obtaining a third polymer fraction, said polymer fraction is the elastomeric copolymer (E), said propylene copolymer (R-PP) and said elastomeric propylene copolymer (E) form the heterophasic propylene copolymer (RAHECO),

g) melt blending the heterophasic propylene copolymer (RAHECO) obtained in step f) with the propylene homopolymer (H-PP) of step a).

14. The process according to claim 13 , wherein the first random propylene copolymer fraction (R-PP1), the random propylene copolymer (R-PP) and the elastomeric copolymer (E) have been polymerized in the presence of:

a) a Ziegler-Natta catalyst (ZN-C) comprising compounds (TC) of a transition metal of Group 4 to 6 of IUPAC, a Group 2 metal compound (MC) and an internal donor (ID), wherein said internal donor (ID) is a non-phthalic compound;

b) optionally a co-catalyst (Co), and

c) optionally an external donor (ED).

Assignments (2)
CHANGE OF ADDRESS Recorded Feb 23, 2022
From: BOREALIS AG
To: BOREALIS AG
Reel/Frame 059219/0949 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 14, 2018
From: WANG, JINGBO; BERGER, FRIEDRICH; DOSHEV, PETAR; GRUENBERGER, MANFRED; SANDHOLZER, MARTINA; GAHLEITNER, MARKUS
To: BOREALIS AG
Reel/Frame 047775/0835 →
Priority Claims (1)
EP 16176618 · Jun 28, 2016 · regional
Continuity (1)
Related Publication 20190330459A1 · Oct 31, 2019