Propylene composition for foaming with improved mechanical properties

1 . A polypropylene composition (C) comprising:

i) from 55.0 to 67.0 wt. %, based on the total weight of the polypropylene composition, of a heterophasic propylene copolymer (HECO) having a melt flow rate MFR 2 measured according to ISO 1133 at 230° C. and 2.16 kg in the range from 10.0 to 40.0 g/10 min, and

a xylene cold soluble fraction (XCS) determined at 23° C. according to ISO 16152 in the range from 25.0 to 40.0 wt. %,

ii) from 25.0 to 45.0 wt. %, based on the total weight of the polypropylene composition, of a copolymer (CP) of propylene and at least one comonomer selected from the group of C 4 -C 10 alpha-olefins that has been synthesized in the presence of a single-site catalyst and has a melt flow rate MFR 2 measured according to ISO 1133 at 230° C. and 2.16 kg in the range from 0.2 to 7.0 g/10 min,

wherein the polypropylene composition (C) has a melt flow rate MFR 2 measured according to ISO 1133 at 230° C. and 2.16 kg of from 1.0 to 30.0 g/10 min, and wherein the polypropylene composition (C) has a Charpy Notched Impact Strength NIS measured according to ISO 179-1eA at 23° C. of greater than or equal to 16.0 KJ/m 2 .

2 . The polypropylene composition (C) according to claim 1 , wherein the polypropylene composition comprises:

from 0 to 15 wt. %, based on the total weight of the polypropylene composition, of a mineral filler (F).

3 . The polypropylene composition (C) according to claim 1 , wherein the copolymer (CP) has a comonomer content of from 0.1 to 5.0 mol. %.

4 . The polypropylene composition (C) according to claim 1 , wherein the copolymer (CP) has a xylene cold soluble fraction (XCS) determined at 23° C. according to ISO 16152 in the range from 0.1 to 7.5 wt. %.

5 . The polypropylene composition (C) according to claim 1 , wherein the copolymer (CP) has a melting temperature (T m ) measured by differential scanning calorimetry (DSC) in the range from 120 to 155° C.

6 . The polypropylene composition (C) according to claim 1 wherein the copolymer (CP) is a copolymer of propylene and 1-butene, or a copolymer of propylene and 1-hexene.

7 . The polypropylene composition (C) according to claim 1 , wherein the heterophasic propylene copolymer (HECO) has:

i) a content of ethylene as determined from 13C-NMR spectroscopy in the range of 5.0 to 20.0 wt. %, and/or

ii) an intrinsic viscosity (iV) of the xylene cold soluble fraction measured according to DIN ISO 1628/1, October 1999 (in Decalin at 135° C.) in the range from 2.0 to 4.0 dl/g, and/or

iii) a Charpy Notched Impact Strength NIS measured according to ISO 179-1 eA at 23° C. in the range of 10.0 to 30.0 KJ/m 2 , and/or

iv) a flexural modulus measured according to ISO 178 in the range of 800 to 1500 MPa.

8 . The polypropylene composition (C) according to claim 2 , wherein the mineral filler (F) is selected from the group of mica, wollastonite, kaolinite, smectite, montmorillonite, talc and mixtures thereof.

9 . The polypropylene composition (C) according to claim 1 , wherein the polypropylene composition (C) has:

i) a tensile modulus measured according to ISO 527-1, −2 in the range of 900 to 2500 MPa, and/or

ii) a flexural modulus measured according to ISO 178 in the range of 850 to 2500 MPa, and/or

iii) a melting temperature (T m ) measured by differential scanning calorimetry (DSC) in the range from 155 to 172° C., and/or

iv) a crystallization temperature (T c ) measured by differential scanning calorimetry (DSC) in the range from 116 to 136° C., and/or

v) a puncture energy measured according to ISO 6603-2 at 23° C. in the range from 10.0 to 50.0 J, and/or

vi) a puncture energy measured according to ISO 6603-2 at −30° C. in the range from 25.0 to 60.0 J, and/or

vii) an elongation at break measured according to ISO 527 in the range from 30 to 750%, and/or

viii) a shrinkage in flow measured according to EN DIN ISO 294-4 of less than 2.0%, and/or

ix) a shrinkage cross flow measured according to EN DIN ISO 294-4 of less than 2.2%.

10 . An injection-molded article comprising the polypropylene composition (C) according to claim 1 .

11 . The injection-molded article according to claim 10 , wherein the article has:

i) a flexural modulus measured according to ISO 178 in the range of 1000 to 1500 MPa, and/or

ii) an energy to max Force measured according to ISO 6603-2 at 23° C. greater than or equal to 10.0 J, and/or

iii) a puncture energy measured according to ISO 6603-2 at 23° C. greater than or equal to 17.0 J.

12 . A foamed article comprising the polypropylene composition according to claim 1 .

13 . The foamed article according to claim 12 , wherein the article has:

i) a flexural modulus measured according to ISO 178 in the range of 600 to 1200 MPa, and/or

ii) an energy to max Force measured according to ISO 6603-2 at 23° C. greater than or equal to 6.0 J, and/or

iii) a puncture energy measured according to ISO 6603-2 at 23° C. greater than or equal to 7.0 J.

14 . The foamed article according to claim 12 , wherein the flexural modulus measured according to ISO 178 is in the range of 200 to 650 MPa lower than the flexural modulus of an unfoamed injection-molded article measured according to ISO 178.