Heterophasic propylene copolymer with low CLTE

1. A polyolefin composition (PO) comprising:

(a) at least 65 wt. %, based on the total weight of the polyolefin composition (PO), of a heterophasic propylene copolymer (HECO) comprising:

(a) a (semi)crystalline polypropylene (PP) having a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 42 to 75 g/10 min; and

(b) an elastomeric propylene copolymer (ESC) dispersed in said (semi)crystalline polypropylene (PP);

(b1) 2 to 15 wt. %, based on the total weight of the polyolefin composition (PO), of a high density polyethylene (HDPE) having a density in the range of 950 to 970 kg/m 3 ; and/or

(b2) 5 to 20 wt. %, based on the total weight of the polyolefin composition (PO), of an inorganic filler (F);

wherein said heterophasic propylene copolymer (HECO) has:

(i) a xylene cold soluble (XCS) fraction in the range of 25 to 38 wt. %;

wherein further the xylene cold soluble (XCS) fraction of said heterophasic propylene copolymer (HECO) has:

(ii) a comonomer content in the range of 30.0 to 65.0 mol %; and

(iii) an intrinsic viscosity (IV) in the range of 1.70 to 2.30 dl/g.

2. A polyolefin composition (PO) according to claim 1 , wherein the intrinsic viscosity (IV) of the xylene cold insoluble (XCI) fraction of the heterophasic propylene copolymer (HECO) is in the range of 1.15 to 1.35 dl/g.

3. A polyolefin composition (PO) comprising:

(a) at least 65 wt. %, based on the total weight of the polyolefin composition (PO), of a heterophasic propylene copolymer (HECO) comprising:

(a) a (semi)crystalline polypropylene (PP); and

(b) an elastomeric propylene copolymer (ESC) dispersed in said (semi)crystalline polypropylene (PP);

(b1) 2 to 15 wt. %, based on the total weight of the polyolefin composition (PO), of a high density polyethylene (HDPE) having a density in the range of 950 to 970 kg/m 3 ; and/or

(b2) 5 to 20 wt. %, based on the total weight of the polyolefin composition (PO), of an inorganic filler (F);

wherein said heterophasic propylene copolymer (HECO) has:

(i) a xylene cold soluble (XCS) fraction in the range of 25 to 38 wt. %;

wherein further the xylene cold soluble (XCS) fraction of said heterophasic propylene copolymer (HECO) has:

(ii) a comonomer content in the range of 30.0 to 65.0 mol %; and

(iii) an intrinsic viscosity (IV) in the range of 1.70 to 2.30 dl/g;

and wherein still further;

(iv) the xylene cold insoluble (XCI) fraction of the heterophasic propylene copolymer (HECO) has an intrinsic viscosity (IV) in the range of 1.15 to 1.35 dl/g.

4. A polyolefin composition (PO) according to claim 1 , the heterophasic propylene copolymer (HECO) having:

(a) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 18 to 40 g/10 min; and/or

(b) a comonomer content in the range of 8.5 to 25 mol %.

5. The polyolefin composition (PO) according to claim 1 , the heterophasic propylene copolymer (HECO) complying with:

(a) the in-equation (3):

MFR

⁡

(

M

)

MFR

⁡

(

T

)

≤

4.0

(

3

)

wherein;

MFR (M) is the melt flow rate MFR 2 (230° C.) measured according to ISO 1133 (g/10 min) of the (semi)crystalline polypropylene (PP);

MFR (T) is the melt flow rate MFR 2 (230° C.) measured according to ISO 1133 (g/10 min) of the heterophasic propylene copolymer (HECO); and/or

(b) the in-equation (2):

1.00

≤

IV

⁡

(

XCS

)

IV

⁡

(

XCI

)

≤

2.00

(

2

)

wherein;

IV (XCS) is the intrinsic viscosity (IV) [dl/g] of the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (HECO), and

IV (XCI) is the intrinsic viscosity (IV) [dl/g] of the xylene cold insoluble (XCI) fraction of the heterophasic propylene copolymer (HECO).

6. The polyolefin composition (PO) of according to claim 1 , wherein said heterophasic propylene copolymer (HECO):

(i) has a xylene cold soluble (XCS) fraction in the range of 27 to 35 wt. %, having a comonomer content in the range of 30.0 to 65.0 mol-% and an intrinsic viscosity (IV) in the range of 1.90 to 2.18 dl/g;

(ii) has a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 18 to 35 g/10 min;

(iii) complies with the in-equation (2):

1.40

≤

IV

⁡

(

XCS

)

IV

⁡

(

XCI

)

≤

1.80

(

2

)

wherein;

IV (XCS) is the intrinsic viscosity (IV) [dl/g] of the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (HECO), and

IV (XCI) is the intrinsic viscosity (IV) [dl/g] of the xylene cold insoluble (XCI) fraction of the heterophasic propylene copolymer (HECO).

7. A polyolefin composition (PO) according to claim 6 , wherein the heterophasic copolymer (HECO):

(a) complies with the in-equation (3):

MFR

⁡

(

M

)

MFR

⁡

(

T

)

≤

4.0

(

3

)

wherein;

MFR (M) is the melt flow rate MFR 2 (230° C.) measured according to ISO 1133 (g/10 min) of the (semi)crystalline polypropylene (PP);

MFR (T) is the melt flow rate MFR 2 (230° C.) measured according to ISO 1133 (g/10 min) of the heterophasic propylene copolymer (HECO); and/or

(b) has a comonomer content in the range of 8.5 to 25 mol %; and/or

(c) wherein the intrinsic viscosity (IV) of the xylene cold insoluble (XCI) fraction of the heterophasic propylene copolymer (HECO) is in the range of 1.15 to 1.35 dl/g.

8. A polyolefin composition (PO) according to claim 1 , wherein:

(a) the (semi)crystalline polypropylene (PP) is a (semi)crystalline propylene homopolymer (H-PP) having a xylene cold soluble (XCS) fraction of less than 4.5 wt. %; and/or

(b) the elastomeric propylene copolymer (ESC) is an ethylene propylene rubber (EPR).

9. The polyolefin composition (PO) of claim 1 , comprising:

(a1) 70 to 90 wt. %, based on the total weight of the polyolefin composition (PO), of the heterophasic propylene copolymer (HECO); and

wherein said heterophasic propylene copolymer (HECO):

(i) has a xylene cold soluble (XCS) fraction in the range of 27 to 35 wt. %, having a comonomer content in the range of 30.0 to 65.0 mol % and an intrinsic viscosity (IV) in the range of 1.90 to 2.18 dl/g;

(ii) has a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 18 to 35 g/10 min;

(iii) complies with the in-equation (2):

1.40

≤

IV

⁡

(

XCS

)

IV

⁡

(

XCI

)

≤

1.80

(

2

)

wherein;

IV (XCS) is the intrinsic viscosity (IV) [dl/g] of the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (HECO), and IV (XCI) is the intrinsic viscosity (IV) [dl/g] of the xylene cold insoluble (XCI) fraction of the heterophasic propylene copolymer (HECO).

10. The polyolefin composition (PO) according to claim 1 , wherein the polyolefin composition (PO) consists of:

(a1) at least 75 wt. % based on the total weight of the polyolefin composition (PO), of the heterophasic propylene copolymer (HECO);

(b1) 2 to 15 wt. % based on the total weight of the polyolefin composition (PO), of the high density polyethylene (HDPE) as defined herein;

(c1) optionally up to 5.0 wt. %, based on the total weight of the polyolefin composition (PO), of alpha nucleating agents (NU); and

(d1) optionally up to 8.0 wt. % based on the total weight of the polyolefin composition (PO), of additives (AD); or

(a2) at least 75 wt. % on the total weight of the polyolefin composition (PO), of the heterophasic propylene copolymer (HECO);

(b2) 2 to 15 wt. based on the total weight of the polyolefin composition (PO), of the inorganic filler (F);

(c2) optionally up to 5.0 wt. % based on the total weight of the polyolefin composition (PO), of alpha nucleating agents (NU); and

(d2) optionally up to 8.0 wt. based on the total weight of the polyolefin composition (PO), of additives (AD).

11. The polyolefin composition (PO) according to claim 1 , consisting of:

(a) 70 to 90 wt. based on the total weight of the polyolefin composition (PO), of the heterophasic propylene copolymer (HECO);

(b) 2 to 15 wt. % based on the total weight of the polyolefin composition (PO), of the high density polyethylene (HDPE); and

(c) 5 to 20 wt. %, based on the total weight of the polyolefin composition (PO), of the inorganic filler (F);

(d) 10 −5 to 2.0 wt. %, based on the total weight of the polyolefin composition (PO), of alpha nucleating agents (NU); and

(e) optionally up to 8.0 wt. % based on the total weight of the polyolefin composition (PO), of additives (AD).

12. The polyolefin composition (PO) according to claim 1 , wherein:

(a) the polyolefin composition (PO) has a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 15 to 40 g/10 min; and/or

(b) the high density polyethylene (HDPE) has a melt flow rate MFR 2 (190° C.) measured according to ISO 1133 in the range of 20 to 80 g/10 min.

13. The polyolefin composition (PO) according to claim 1 , wherein:

(a) the weight ratio between the inorganic filler (F) and the high density polyethylene (HDPE) [(F)/(HDPE)] is at least 0.6; and/or

(b) the weight ratio between the xylene cold soluble (XCS) fraction of the heterophasic propylene copolymer (HECO) and the high density polyethylene (HDPE) [(XCS)/(HDPE)] is above 2.0; and/or

(c) the weight ratio between the heterophasic propylene copolymer (HECO) and the high density polyethylene (HDPE) [(HECO)/(HDPE)] is in the range of 5/1 to 25/1.

14. The polyolefin composition (PO) according to claim 1 , wherein the inorganic filler (F) has a cutoff particle size d95 [mass percent] of equal or below 3.3 μm.

15. The polyolefin composition (PO) according to claim 1 , wherein the polyolefin composition (PO) has:

(a) tensile modulus of at least 1100 MPa; and/or

(b) impact strength at +23° C. of at least 20 kJ/m 2 ; and/or

(c) a coefficient of linear thermal expansion (CLTE) performed in a temperature range from −30 to +80° C. of not more than 80 μm/mK.