Heterophasic polypropylene polymer

Patent metadata

Field	Value
Publication number	US-9932469-B2
Application number	US-201515109855-A
Country	US
Kind code	B2
Filing date	Jan 6, 2015
Priority date	Jan 7, 2014
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

A heterophasic propylene ethylene copolymer having an MFR 2 of 0.5 to 100 g/10 m in and obtained using single site catalysis comprising: (i) a propylene homopolymer or propylene ethylene copolymer matrix having up to 4 wt % ethylene; and (ii) an ethylene propylene rubber (EPR) dispersed in the matrix; said heterophasic propylene ethylene copolymer having a xylene cold soluble content (XS) of 20 to 40%; wherein the ethylene content of the xylene cold soluble fraction of said heterophasic propylene ethylene copolymer is between 70 and 90 wt. %; wherein the xylene cold soluble fraction of said heterophasic propylene ethylene copolymer has an intrinsic viscosity (IV) of 3.0 dl/g or more; and wherein the melting enthalpy (ΔHM) of the heterophasic propylene ethylene copolymer is between 10 and 30 J/g at a temperature of 0 to 130° C.

First claim

The invention claimed is:

1. A heterophasic propylene ethylene copolymer having an MFR 2 of 0.5 to 100 g/10 min and obtained using single site catalysis comprising:
(i) a propylene homopolymer or propylene ethylene copolymer matrix having up to 4 wt % ethylene; and
(ii) an ethylene propylene rubber (EPR) dispersed in the matrix;
said heterophasic propylene ethylene copolymer having a xylene cold soluble content (XS) of 20 to 40%;
wherein the ethylene content of the xylene cold soluble fraction of said heterophasic propylene ethylene copolymer is between 70 and 90 wt. %;
wherein the xylene cold soluble fraction of said heterophasic propylene ethylene copolymer has an intrinsic viscosity (IV) of 3.0 dl/g or more; and
wherein the melting enthalpy (ΔHm) of the heterophasic propylene ethylene copolymer is between 10 and 30 J/g at a temperature of 0 to 130° C.

2. A heterophasic copolymer as claimed in claim 1 which is formed in three steps.

3. A heterophasic copolymer as claimed in claim 1 wherein the matrix component is a homopolymer.

4. A heterophasic copolymer as claimed in claim 1 wherein there is 20 to 35 wt % XS component.

5. A heterophasic copolymer as claimed in claim 1 having an MFR 2 of 0.7 to 60 g/10 min.

6. A heterophasic copolymer as claimed in claim 1 wherein the C2(XS) content is 71 to 90 wt %.

7. A heterophasic copolymer as claimed in claim 1 wherein the IV(XS) is in the range of 3.0 to 4.0 dl/g.

8. A heterophasic copolymer as claimed in claim 1 wherein the charpy impact strength is at least 50 kJ/m 2 at 23° C.

9. A heterophasic copolymer as claimed in claim 1 wherein the brittle to ductile transition temperature occurs at 0° C. or less.

10. A heterophasic copolymer as claimed in claim 1 having at least two melting points.

11. A heterophasic copolymer as claimed in claim 1 wherein the glass transition temperature of the xylene soluble fraction is −30 to −45° C.

12. A process for the preparation of a heterophasic propylene ethylene copolymer as claimed in claim 1 comprising polymerising:
(I) propylene and optionally ethylene so as to form a propylene homopolymer or propylene ethylene copolymer matrix having up to 4 wt % ethylene as said matrix component; and subsequently polymerising
(II) propylene and ethylene so as to form an ethylene propylene rubber dispersed in the matrix;
wherein both steps (I) and (II) take place in the presence of the same single site solid particulate catalyst free from an external carrier comprising (i) a complex of formula (I):

wherein
M is zirconium or hafnium;
each X is a sigma ligand;
L is a divalent bridge selected from —R′ 2 C—, —R′ 2 C—CR′ 2 —, —R′ 2 Si—, —R′ 2 Si—SiR′ 2 —, —R′ 2 Ge—, wherein each R′ is independently a hydrogen atom, C 1 -C 20 -hydrocarbyl, tri(C 1 -C 20 -alkyl)silyl, C 6 -C 20 -aryl, C 7 -C 20 -arylalkyl or C 7 -C 20 -alkylaryl;
R 2 and R 2 ′ are each independently a C 1 -C 20 hydrocarbyl radical optionally containing one or more heteroatoms from groups 14-16;
R 5′ is a C 1-20 hydrocarbyl group containing one or more heteroatoms from groups 14-16 optionally substituted by one or more halo atoms;
R 6 and R 6′ are each independently hydrogen or a C 1-20 hydrocarbyl group optionally containing one or more heteroatoms from groups 14-16;
R 7 and R 7′ are each independently hydrogen or C 1-20 hydrocarbyl group optionally containing one or more heteroatoms from groups 14-16;
Ar is independently an aryl or heteroaryl group having up to 20 carbon atoms optionally substituted by one or more groups R 1 ;
Ar′ is independently an aryl or heteroaryl group having up to 20 carbon atoms optionally substituted by one or more groups R 1 ;
each R 1 is a C 1-20 hydrocarbyl group or two R 1 groups on adjacent carbon atoms taken together can form a fused 5 or 6 membered non aromatic ring with the Ar group, said ring being itself optionally substituted with one or more groups R 4 ;
each R 4 is a C 1-20 hydrocarbyl group;
and (ii) a cocatalyst comprising a compound of a group 13 metal.

13. A process for the preparation of a propylene ethylene copolymer as claimed in claim 12 in which the catalyst is prepared by obtaining a complex of formula (I) and a cocatalyst (ii);
forming a liquid/liquid emulsion system, which comprises a solution of catalyst components (i) and (ii) dispersed in a solvent, and solidifying said dispersed droplets to form solid particles.

14. An article comprising the heterophasic propylene ethylene copolymer as claimed in claim 1 .

15. The process of claim 12 , wherein in step (II) propylene and ethylene are polymerised in the gas phase.

16. The process of claim 12 , wherein the group 13 metal is an aluminium compound or a boron compound.

17. The article of claim 14 , wherein the article comprises a film.

Assignees

• Borealis Ag
• Borealis Ag

Inventors

• Wang Jingbo
• Doshev Petar
• Resconi Luigi
• Toltsch Wilfried

Classifications

• C08F2/001

  Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer (C08F295/00, C08F297/00 take precedence) · CPC title

• C08F210/16

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08J2323/16

  Ethene-propene or ethene-propene-diene copolymers · CPC title

• C08F210/06 Primary

  Propene · CPC title

• C08F110/06

  Propene · CPC title