Low emission propylene homopolymer with high melt flow

1. A propylene homopolymer having

(a) a melt flow rate MFR 2 (230° C./2.16 kg) measured according to ISO 1133 in the range of 75.0 to 500 g/10 min; and

(b) a pentad isotacticity (mmmm) of more than 90.0% determined by 13 C-NMR spectroscopy

wherein further

(c) the propylene homopolymer fulfills inequation (I)

VOC≦(MFR×0.08)+201.0

wherein

VOC is the amount of volatile organic compounds (VOC) [in ppm] measured according to VDA 278:2002 of the propylene homopolymer;

MFR is the melt flow rate MFR 2 (230° C./2.16 kg) measured according to ISO 1133 of the propylene homopolymer, and

(d) the propylene homopolymer has a melting temperature Tm of equal to or more than 160° C.

2. The propylene homopolymer according to claim 1 having an amount of volatile organic compounds (VOC) measured according to VDA 278:2002 of equal or below 210 ppm.

3. The propylene homopolymer according to claim 1 having a crystallization temperature of equal to or more than 114° C.

4. The propylene homopolymer according to claim 1 , having a xylene cold soluble content (XCS) determined according ISO 16152 (25° C.) of at least 1.8 wt.-%.

5. The propylene homopolymer according to claim 1 , having 2,1 erythro regio-defects of equal to or below 0.4 mol.-% determined by 13 C-NMR spectroscopy.

6. The propylene homopolymer according to claim 1 , having a pentad isotacticity (mmmm) of more than 93.0%.

7. The propylene homopolymer according to claim 1 , fulfilling inequation (II)

FOG≦(MFR×1.26)+350.0

wherein

FOG is the amount of fogging compounds (FOG) [in ppm] measured according to VDA 278:2002 of the propylene homopolymer; and

MFR is the melt flow rate MFR 2 (230° C./2.16 kg) measured according to ISO 1133 of the propylene homopolymer.

8. The propylene homopolymer according to claim 1 , having an amount of fogging compounds (FOG) measured according to VDA 278:2002 of not more than 580 ppm.

9. The propylene homopolymer according to claim 1 , having a tensile modulus measured at 23° C. according to ISO 527-1 (cross head speed 1 mm/min) of at least 1,500 MPa.

10. An article comprising the propylene homopolymer according claim 1 .

11. A process for producing a propylene homopolymer according to claim 1 , wherein propylene has 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 selected from optionally substituted glutarates and citraconate;

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

(c) optionally an external donor (ED), and

(d) the molar-ratio of co-catalyst (Co) to external donor (ED) [Co/ED] is 5 to 45.

12. The process according to claim 11 , wherein the propylene homopolymer is produced in a sequential polymerization process comprising at least two reactors (R1) and (R2), in the first reactor (R1) a first propylene homopolymer fraction (H-PP1) is produced and subsequently transferred into the second reactor (R2), in the second reactor (R2) a second propylene homopolymer fraction (H-PP2) is produced in the presence of the first propylene homopolymer fraction (H-PP1).

13. The propylene homopolymer according to claim 2 , having a crystallization temperature of equal to or more than 114° C.

14. The propylene homopolymer according to claim 2 , having a xylene cold soluble content (XCS) determined according ISO 16152 (25° C.) of at least 1.8 wt.-%.

15. The propylene homopolymer according to claim 2 , having 2,1 erythro regio-defects of equal to or below 0.4 mol.-% determined by 13 C-NMR spectroscopy.

16. The propylene homopolymer according to claim 2 , having a pentad isotacticity (mmmm) of more than 93.0%.

17. The propylene homopolymer according to claim 2 , fulfilling inequation (II)

FOG≦(MFR×1.26)+350.0

wherein

FOG is the amount of fogging compounds (FOG) [in ppm] measured according to VDA 278:2002 of the propylene homopolymer; and

MFR is the melt flow rate MFR 2 (230° C./2.16 kg) measured according to ISO 1133 of the propylene homopolymer.