High flow thermoplastic polyolefin with balanced mechanical performance and low shrinkage and CLTE

1. A thermoplastic polyolefin (TPO) composition having a melt flow rate MFR 2 (230° C.) between 20 and 100 g/10 min measured according to ISO 1133, comprising

a) a matrix phase (M) comprising a propylene homopolymer (H-PP) and/or a propylene copolymer (R-PP), and

b) a dispersed phase (D) comprising an ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP),

wherein

(i) the composition comprises 20 wt.-% to 45 wt.-%, based on the total weight of the composition, of a xylene cold soluble (XCS) fraction having

(i-a) an ethylene content in the range of 40 wt.-% to 65 wt.-%, and

(i-b) an intrinsic viscosity (IV) of below 1.5 dL/g measured according to ISO 1628, and

(ii) the ratio of the intrinsic viscosity (IV) of xylene cold insoluble (XCI) fraction to the intrinsic viscosity (IV) of the xylene cold soluble (XCS) fraction ([XCS]/[XCI]) of the thermoplastic polyolefin (TPO) composition is in the range of 0.75 to 1.35,

and wherein the composition comprises

(a) 30 wt.-% to 45 wt.-%, based on the total weight of the composition, of the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP).

2. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the composition comprises

(a) 55 wt.-% to 70 wt.-%, based on the total weight of the composition, of the matrix phase (M),

and/or

(b) 55 to 80 wt.-%, based on the total weight of the composition, of the xylene cold insoluble (XCI) fraction.

3. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the matrix phase (M) is a propylene homopolymer.

4. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the matrix phase (M) and/or the xylene cold insoluble (XCI) fraction has/have a melt flow rate MFR 2 (230° C.) of at least 50 g/10 min measured according to ISO 1133.

5. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the matrix phase (M) and/or the xylene cold insoluble (XCI) fraction has/have an intrinsic viscosity (IV) measured according to ISO 1628 of below 1.5 dL/g.

6. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) and/or the xylene cold soluble (XCS) fraction has/have an ethylene content in the range of 40 wt.-% to 55 wt.-% based on the total weight of the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) and the xylene cold soluble (XCS) fraction, respectively.

7. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) is an ethylene-propylene or ethylene-1-octene copolymer rubber.

8. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) and/or the xylene cold soluble (XCS) fraction has/have an intrinsic viscosity (IV) measured according to ISO 1628 between 0.7 and 1.5 dL/g.

9. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the composition

(a) is free of inorganic filler,

and/or

(b) is α-nucleated, i.e. comprises a α-nucleating agent in a total amount of below 1 wt.-%.

10. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the composition has a melt flow rate MFR 2 (230° C.) between 30 and 100 g/10 min measured according to ISO 1133.

11. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the ratio of intrinsic viscosity (IV) of the propylene homo- or copolymer matrix phase (M) to the intrinsic viscosity (IV) of the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) ([M]/[EOP]) is in the range of 0.75 to 1.35.

12. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the thermoplastic polyolefin (TPO) composition is a reactor grade thermoplastic polyolefin (rTPO) composition.

13. The thermoplastic polyolefin (TPO) composition according to claim 1 , further comprising an injection moulded article.

14. The thermoplastic polyolefin (TPO) composition according to claim 13 , wherein said injection molded article is an automotive part.

15. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the matrix phase (M) and/or the xylene cold insoluble (XCI) fraction has/have a melt flow rate MFR 2 (230° C.) of between 50 and 200 g/10 min measured according to ISO 1133.

16. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the matrix phase (M) and/or the xylene cold insoluble (XCI) fraction has/have a melt flow rate MFR 2 (230° C.) of between 80 and 200 g/10 min measured according to ISO 1133.

17. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the matrix phase (M) and/or the xylene cold insoluble (XCI) fraction has/have a melt flow rate MFR 2 (230° C.) of between 80 and 150 g/10 min measured according to ISO 1133.

18. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the matrix phase (M) and/or the xylene cold insoluble (XCI) fraction has/have an intrinsic viscosity (IV) measured according to ISO 1628 of between 0.7 and 1.5 dL/g.

19. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the matrix phase (M) and/or the xylene cold insoluble (XCI) fraction has/have an intrinsic viscosity (IV) measured according to ISO 1628 of between 0.8 and 1.4 dL/g.

20. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the matrix phase (M) and/or the xylene cold insoluble (XCI) fraction has/have an intrinsic viscosity (IV) measured according to ISO 1628 of between 1 and 1.2 dL/g.

21. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) and/or the xylene cold soluble (XCS) fraction has/have an ethylene content in the range of 45 wt.-% to 55 wt.-% based on the total weight of the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) and the xylene cold soluble (XCS) fraction, respectively.

22. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) and/or the xylene cold soluble (XCS) fraction has/have an ethylene content in the range of 45 wt.-% to 50 wt.-% based on the total weight of the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) and the xylene cold soluble (XCS) fraction, respectively.

23. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) and/or the xylene cold soluble (XCS) fraction has/have an intrinsic viscosity (IV) measured according to ISO 1628 between 0.8 and 1.5 dL/g.

24. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) and/or the xylene cold soluble (XCS) fraction has/have an intrinsic viscosity (IV) measured according to ISO 1628 between 0.9 and 1.4 dL/g.

25. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the composition has a melt flow rate MFR 2 (230° C.) between 30 and 90 g/10 min measured according to ISO 1133.

26. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the composition has a melt flow rate MFR 2 (230° C.) between 40 and 80 g/10 min measured according to ISO 1133.

27. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the ratio of intrinsic viscosity (IV) of the propylene homo- or copolymer matrix phase (M) to the intrinsic viscosity (IV) of the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) ([M]/[EOP]) is in the range of 0.80 to 1.20.

28. The thermoplastic polyolefin (TPO) composition according to claim 1 , wherein the ratio of intrinsic viscosity (IV) of the propylene homo- or copolymer matrix phase (M) to the intrinsic viscosity (IV) of the ethylene-C 3 -C 8 -α-olefin rubber copolymer (EOP) ([M]/[EOP]) is in the range of 0.90 and 1.20.