High flow and stiff polymer material with good transparency and impact properties

1. Polypropylene composition having a melt flow rate MFR 2 measured at 230° C. according to ISO 1133 of equal or above 15 g/10 min comprising

(a) a crystalline polypropylene matrix (M-PP)

(b) an elastomeric propylene copolymer phase (E) having

(i) a propylene content in the range of 40 to 80 wt.-%, and

(ii) an intrinsic viscosity (IV) measured according to ISO 1628-1 at 135° C. in decalin in the range of more than 0.7 to less or equal 2.5 dl/g,

(c) a first polyethylene (PE1) having

(i) a density measured according to ISO 1183-187 in the range 905 to 925 kg/m 3 , and

(ii) a melt flow rate MFR 2 measured at 190° C. according to ISO 1133 of below 30 g/10 min, and

(iii) a molecular weight distribution (MWD) determined by gel permeation chromatography (GPC) of at least 10,

(d) a second polyethylene (PE2) having

(i) a density measured according to ISO 1183-187 of above 915 kg/m 3 , and

(ii) a melt flow rate MFR 2 measured at 190° C. according to ISO 1133 of equal or above 30 g/10 min, and

(iii) a molecular weight distribution (MWD) determined by gel permeation chromatography (GPC) of below 10.

2. Polypropylene composition according to claim 1 , wherein the crystalline polypropylene matrix (M-PP) has

(a) a melt flow rate MFR 2 measured at 230° C. according to ISO 1133 in the range of 30 to 100 g/10 min,

and/or

(b) has a xylene cold soluble content (XCS) of equal or below 4.0 wt.-%,

and/or

(c) a melting temperature Tm determined by differential scanning calorimetry (DSC) of at least 145° C.

3. Polypropylene composition according to claim 1 , wherein the crystalline polypropylene matrix (M-PP)

(a) has a comonomer content of equal or below 4.0 wt.-%,

and/or

(b) comprises at least two different crystalline polypropylene fractions, said fractions differ in the comonomer content.

4. Polypropylene composition according to claim 3 , wherein the crystalline polypropylene matrix (M-PP) comprises

(a) at least one propylene homopolymer fraction and/or at least one random propylene copolymer fraction,

and/or

(b) one propylene homopolymer (H-PP) and one random propylene copolymer (R-PP), wherein further the weight ratio (H-PP/R-PP) between the propylene homopolymer (H-PP) and the random propylene copolymer n (R-PP) is 70/30 to 30/70.

5. Polypropylene composition according to claim 1 , wherein the elastomeric propylene copolymer phase (E) comprises a first elastomeric propylene copolymer (E1) and a second elastomeric propylene copolymer (E2), the first elastomeric propylene copolymer (E1) and the second elastomeric propylene copolymer (E2) differ in their intrinsic viscosity measured according to ISO 1628-1 at 135° C. in decalin.

6. Polypropylene composition according to claim 5 , wherein the weight ratio (E1/E2) between the first elastomeric propylene copolymer (E1) and the second elastomeric propylene copolymer (E2) is 80/20 to 20/80.

7. Polypropylene composition according to claim 5 , wherein the first elastomeric propylene copolymer (E1) has

(i) a propylene content in the range of 25 to 60 wt.-%, and

(ii) an intrinsic viscosity (IV) measured according to ISO 1628-1 at 135° C. in decalin in the range 0.5 to 2.5 dl/g.

8. Polypropylene composition according to claim 5 , wherein the second elastomeric propylene copolymer (E2) has

(i) a propylene content in the range of 50 to 85 wt.-%, and

(ii) an intrinsic viscosity (IV) measured according to ISO 1628-1 at 135° C. in decalin in the range 1.0 to below 3.0 dl/g.

9. Polypropylene composition according to claim 5 , wherein the elastomeric propylene copolymer phase (E) is dispersed within the crystalline polypropylene matrix (M-PP).

10. Polypropylene composition according to claim 1 , wherein the first polyethylene (PE1) has

(a) an ethylene content of at least 80 wt.-%,

and/or

(b) a molecular weight distribution determined by gel permeation chromatography (GPC) of at least 10.

11. Polypropylene composition according to claim 1 , wherein the second polyethylene (PE2) has

(a) an ethylene content of at least 80 wt.-%.

12. Polypropylene composition according claim 1 , wherein the polypropylene composition comprises additionally an α-nucleating agent (NA).

13. Polypropylene composition according to claim 1 , wherein the composition comprises

(a1) 55 to 80 wt.-% of the crystalline polypropylene matrix (M-PP)

(b1) 7.5 to 30 wt.-% of the elastomeric propylene copolymer phase (E),

(c1) 2.5 to 15 wt.-% of the first polyethylene (PE1),

(d1) 2.5 to 15 wt.-% of the second polyethylene (PE2), and

(e1) 0.0005 to 1.0 wt.-% of a α-nucleating agent (NA),

or

(a2) 55 to 80 wt.-% of the crystalline polypropylene matrix (M-PP)

(b2) 2.5 to 20 wt.-% of a first elastomeric propylene copolymer (E1),

(c2) 2.5 to 20 wt.-% of a second elastomeric propylene copolymer (E2),

(d2) 2.5 to 15 wt.-% of the first polyethylene (PE1),

(e2) 2.5 to 15 wt.-% of the second polyethylene (PE2), and

(f2) 0.0005 to 1.0 wt.-% of a α-nucleating agent (NA),

or

(a3) 15 to 55 wt.-% of a first crystalline polypropylene fraction being part of the crystalline polypropylene matrix (M-PP),

(b3) 15 to 55 wt.-% of a second crystalline polypropylene fraction being part of the crystalline polypropylene matrix (M-PP)

(c3) 2.5 to 20 wt.-% of a first elastomeric propylene copolymer (E1),

(d3) 2.5 to 20 wt.-% of a second elastomeric propylene copolymer (E2),

(e3) 2.5 to 15 wt.-% of the first polyethylene (PE1),

(f3) 2.5 to 15 wt.-% of the second polyethylene (PE2), and

(g3) 0.0005 to 1.0 wt.-% of a α-nucleating agent (NA).

14. Injection molded article comprising a polypropylene composition having a melt flow rate MFR 2 measured at 230° C. according to ISO 1133 of equal or above 15 g/10 min comprising

(a) a crystalline polypropylene matrix (M-PP)

(b) an elastomeric propylene copolymer phase (E) having

(i) a propylene content in the range of 40 to 80 wt.-%, and

(ii) an intrinsic viscosity (IV) measured according to ISO 1628-1 at 135° C. in decalin in the range of more than 0.7 to less or equal 2.5 dl/g,

(c) a first polyethylene (PE1) having

(i) a density measured according to ISO 1183-187 in the range 905 to 925 kg/m 3 , and

(ii) a melt flow rate MFR 2 measured at 190° C. according to ISO 1133 of below 30 g/10 min, and

(iii) a molecular weight distribution (MWD) determined by gel permeation chromatography (GPC) of at least 10,

(d) a second polyethylene (PE2) having

(i) a density measured according to ISO 1183-187 of above 915 kg/m 3 , and

(ii) a melt flow rate MFR 2 measured at 190° C. according to ISO 1133 of equal or above 30 g/10 min, and

(iii) a molecular weight distribution (MWD) determined by gel permeation chromatography (GPC) of below 10.

15. Process for the preparation of polypropylene composition having a melt flow rate MFR 2 measured at 230° C. according to ISO 1133 of equal or above 15 g/10 min comprising

(a) a crystalline polypropylene matrix (M-PP)

(b) an elastomeric propylene copolymer phase (E) having

(i) a propylene content in the range of 40 to 80 wt.-%, and

(ii) an intrinsic viscosity (IV) measured according to ISO 1628-1 at 135° C. in decalin in the range of more than 0.7 to less or equal 2.5 dl/g,

(c) a first polyethylene (PE1) having

(i) a density measured according to ISO 1183-187 in the range 905 to 925 kg/m 3 , and

(ii) a melt flow rate MFR 2 measured at 190° C. according to ISO 1133 of below 30 g/10 min, and

(iii) a molecular weight distribution (MWD) determined by gel permeation chromatography (GPC) of at least 10,

(d) a second polyethylene (PE2) having

(i) a density measured according to ISO 1183-187 of above 915 kg/m 3 , and

(ii) a melt flow rate MFR 2 measured at 190° C. according to ISO 1133 of equal or above 30 g/10 min, and

(iii) a molecular weight distribution (MWD) determined by gel permeation chromatography (GPC) of below 10;

comprising the steps of mixing up a composition comprising the polypropylene matrix (M-PP) and the elastomeric propylene copolymer phase (E), the first polyethylene (PE1), the second polyethylene (PE2), and optionally a α-nucleating agent (NA) in an extruder.