POLYPROPYLENE COMPOSITION

Abstract

The invention is directed to a polypropylene composition, to a three-dimensional article comprising said polypropylene composition, and to the use of said polypropylene composition. The polypropylene composition of the invention comprises a) a multimodal polypropylene homopolymer comprising at least the following fractions i) 10-30% by total weight of the polypropylene composition of a fraction with a melt flow index of 5-45 g/10 min; ii) 10-30% by total weight of the polypropylene composition of a fraction with a melt flow index of 50-200 g/10 min; and iii) 3-10% by total weight of the polypropylene composition of a fraction with a melt flow index of 250-900 g/10 min; wherein the melt flow index is as measured according to ISO 1133 using a 2.16 kg weight and at a temperature of 230° C.; b) 1-8% by total weight of the polypropylene composition of a first C.sub.2/C.sub.3 phase having an intrinsic viscosity at 135° C. of 1.5-2.5 dl/g, of which the ethylene content in the xylene cold soluble fraction is 45-65% by total weight of the xylene cold soluble fraction; c) 1-8% by total weight of the polypropylene composition of a second C.sub.2/C.sub.3 phase having an intrinsic viscosity at 135° C. of 2.6-4.0 dl/g, of which the ethylene content in the xylene cold soluble fraction is 45-65% by total weight of the xylene cold soluble fraction; d) 10-25% by total weight of the polypropylene composition of a C.sub.2/C.sub.8 phase having an intrinsic viscosity at 135° C. of 1.2-2.1 dl/g and a density of 0.85-0.89 g/cm3; and e) 10-30% by total weight of the polypropylene composition of a mineral filler.

Claims

1. Polypropylene composition comprising: a) a multimodal polypropylene homopolymer comprising at least the following fractions i) 10-30% by total weight of the polypropylene composition of a fraction with a melt flow index of 5-45 g/10 min; ii) 10-30% by total weight of the polypropylene composition of a fraction with a melt flow index of 50-200 g/10 min; and iii) 3-10% by total weight of the polypropylene composition of a fraction with a melt flow index of 250-900 g/10 min; wherein the melt flow index is as measured according to ISO 1133 using a 2.16 kg weight and at a temperature of 230° C.; b) 1-8% by total weight of the polypropylene composition of a first C.sub.2/C.sub.3 phase having an intrinsic viscosity at 135° C. of 1.5-2.5 dl/g, of which the ethylene content in the xylene cold soluble fraction is 45-65% by total weight of the xylene cold soluble fraction; c) 1-8% by total weight of the polypropylene composition of a second C.sub.2/C.sub.3 phase having an intrinsic viscosity at 135° C. of 2.6-4.0 dl/g, of which the ethylene content in the xylene cold soluble fraction is 45-65% by total weight of the xylene cold soluble fraction; d) 10-25% by total weight of the polypropylene composition of a C.sub.2/C.sub.8 phase having an intrinsic viscosity at 135° C. of 1.2-2.1 dl/g and a density of 0.85-0.89 g/cm.sup.3; and e) 10-30% by total weight of the polypropylene composition of a mineral filler.

2. Polypropylene composition according to claim 1, wherein the multimodal polypropylene homopolymer a) is a trimodal polypropylene homopolymer.

3. Polypropylene composition according to claim lclaim 1 or 2, wherein fraction i) of the multimodal polypropylene homopolymer has a melt flow index of 7-30 g/10 min.

4. Polypropylene composition according to claim 1, wherein fraction ii) of the multimodal polypropylene homopolymer has a melt flow index of 70-150 g/10 min.

5. (canceled)

6. Polypropylene composition according to claim 1, wherein the composition comprises 15-25% by total weight of the polypropylene composition of the multimodal polypropylene homopolymer fraction with a melt flow index of 5-45 g/10 min.

7. (canceled)

8. Polypropylene composition according to claim 1, wherein the composition comprises 15-25% by total weight of the polypropylene composition of the multimodal polypropylene homopolymer fraction with a melt flow index of 50-200 g/10 min.

9. (canceled)

10. Polypropylene composition according to claim 1, wherein the composition comprises 4-9% by total weight of the polypropylene composition of the multimodal polypropylene homopolymer fraction with a melt flow index of 250-900 g/10 min.

11. Polypropylene composition according to claim 1, wherein the composition comprises 5-8% by total weight of the polypropylene composition of the multimodal polypropylene homopolymer fraction with a melt flow index of 250-900 g/10 min.

12. Polypropylene composition according to claim 1, wherein the mineral filler is selected from the group consisting of mica, wollastonite, kaolinite, smectite, montmorillonite and talc.

13. (canceled)

14. Polypropylene composition according to claim 1, wherein the mineral filler has a median particle size d.sub.50 of 0.8-12.0 μm when measured on uncompacted material according to ISO 13317-3 using a Sedigraph.

15. Polypropylene composition according to claim 1, wherein the mineral filler has a median particle size d.sub.50 of 1.0-5.0 μm when measured on uncompacted material according to ISO 13317-3 using a Sedigraph.

16. Polypropylene composition according to claim 1, wherein the mineral filler has a BET nitrogen surface area as measured according to DIN 66131-2 of 8-25 m.sup.2/g.

17. Polypropylene composition according to claim 1, wherein the mineral filler has a BET nitrogen surface area as measured according to DIN 66131-2 of 10-20 m.sup.2/g.

18. Polypropylene composition according to claim 1, wherein said composition exhibits a Charpy notched impact strength at 23° C. as measured according to ISO 179-1eA of 25 kJ/m.sup.2 or more, preferably 30 kJ/m.sup.2 or more.

19. Polypropylene composition according to claim 1, wherein said composition exhibits a Charpy notched impact strength at 23° C. as measured according to ISO 179-1eA of 30-50 kJ/m.sup.2.

20-21. (canceled)

22. Polypropylene composition according to claim 1, wherein said composition exhibits a flexural modulus as measured according to ISO 178 of 1500 MPa or more, preferably 1600 MPa or more.

23. Polypropylene composition according to claim 1, wherein said composition exhibits a flexural modulus as measured according to ISO 178 of 1700-1900 MPa.

24-25. (canceled)

26. Polypropylene composition according to claim 1, wherein said composition exhibits an elongation at break as measured according to ISO 527-3 of 50% or more, preferably 55% or more.

27-29. (canceled)

30. Three-dimensional article comprising a polypropylene composition according to claim 1.

31. Three-dimensional article according to claim 30, in the form of an automotive article.

32. (canceled)

Description

EXAMPLES

[0071] Table 1 below shows the formulation of a comparative and inventive polypropylene composition.

TABLE-US-00001 TABLE 1 Compar- Inven- ative tive Component example example Component Supplier description (wt. %) (wt. %) PP Sabic polypropylene block 25 30 513MNK10 .sup.1 copolymer PP Sabic polypropylene block 20 20 48M10 .sup.2 copolymer H-PP Polypropylene homo- — 5 MFR440 polymer, experimental sample obtained by shifting (i.e. visbreaking) a conventional homopolymer with a MFI of 50 to 440 g/10 min ENGAGE ™ The Dow ethylene-octene 20 20 8200 Chemical copolymer Company ImiFabi ImiFabi talc 20 20 Ultra 5C Talc Exxelor ™ Exxon maleic anhydride 0.2 0.2 PO1020 Mobil functionalised homopolypropylene .sup.1 PP513MNK10 is a polypropylene block copolymer with a matrix MFI of 70 g/10 min, a total MFI of 65 g/10 min (after visbreaking from an MFI of 35 g/10 min), a rubber content expressed as XCS of 16.5 wt. %, an intrinsic viscosity of the XCS fraction of 2.2 dl/g and a C2-content of the XCS fraction of 49 wt. %. .sup.2 PP 48M10 is a polypropylene block copolymer with a matrix MFI of 30 g/10 min, a total MFI of 14 g/10 min, a rubber content expressed as XCS of 15 wt. %, an intrinsic visocisty of the XCS fraction of rubber of 2.9 dl/g and a C2-content of the XCS fraction of 52 wt. %

[0072] Table 2 shows various properties determined for the comparative and inventive example.

TABLE-US-00002 TABLE 2 Comparative Inventive example example Melt flow index (g 10 min) 17.6 36.5 Ash content (wt. %) 20.8 20.1 Charpy notched impact strength 37 33.5 at 23° C. (kJ/m.sup.2) Charpy notched impact strength 5.4 5.2 at −20° C. (kJ/m.sup.2) Flexural modulus (MPa) 1715 1750 Tensile modulus (MPa) 1650 1750 Elongation at break (%) 70 60 Average Shrinkage after 24 h at 0.63 0.66 23° C. (%) Shrinkage parallel to flow after 0.59 0.63 24 h at 23° C. (%) Shrinkage perpendicular to flow after 0.67 0.69 24 h at 23° C. (%)