Superior stress whitening performance for battery cases

1. An injection molded article (IMA) comprising at least 90 wt.-%, based on the total weight of the injection molded article (IMA), of a polypropylene composition (PC), wherein said polypropylene composition (PC) comprises

(a) at least 88.25 wt.-%, based on the total weight of the polypropylene composition (PC), of a heterophasic propylene copolymer (RAHECO);

(b) 0.005 to 0.350 wt.-%, based on the total weight of the polypropylene composition (PC), of an organic metal deactivator (MD);

(c) 0.005 to 0.400 wt.-%, based on the total weight of the polypropylene composition (PC), of a sulphur containing antioxidant (SAO);

(d) 0 to 3.0 wt.-%, based on the total weight of the polypropylene composition (PC), of an inorganic filler (F); and

(e) 0 to 8.0 wt.-%, based on the total weight of the polypropylene composition (PC), of a high density polyethylene (HDPE);

wherein further

the heterophasic propylene copolymer (RAHECO)

(i) has a comonomer content in the range of 5.0 to 15.0 mol.-%,

(ii) has a xylene cold soluble (XCS) fraction in the range of 9.0 to 18 wt.-%,

(iii) comprises a propylene copolymer (M) having a comonomer content in the range of 0.4 to 2.0 mol.-%, and

(iv) comprises an elastomeric propylene copolymer (R).

2. The injection molded article (IMA) according to claim 1 , wherein the injection molded article (IMA) and/or the polypropylene composition (PC)

(a) do(es) not contain a high density polyethylene (HDPE);

or

(b) comprise(s) a high density polyethylene (HDPE), wherein the polypropylene composition (PC) comprises more than 0 to 8 wt.-%, based on the total weight of the polypropylene composition (PC), of the high density polyethylene (HDPE).

3. The injection molded article (IMA) according to claim 1 , wherein the injection molded article (IMA) and/or the polypropylene composition (PC)

(a) do(es) not contain an inorganic filler (F);

or

(b) contain(s) an inorganic filler (F), wherein the polypropylene composition (PC) comprises more than 0 to 2 wt.-%, based on the total weight of the polypropylene composition (PC), of the inorganic filler (F).

4. The injection molded article (IMA) according to claim 1 , wherein the comonomer of the propylene copolymer (M) is selected from ethylene, C4 to C12 α-olefin, and mixtures thereof.

5. The injection molded article (IMA) according to claim 1 , wherein

(a) the elastomeric propylene copolymer (R) has a comonomer content in the range of 45 to 65 mol.-%;

and/or

(b) the comonomer of the elastomeric propylene copolymer (R) is selected from ethylene, C 4 to C 12 α-olefin, and mixtures thereof.

6. The injection molded article (IMA) according to claim 1 , wherein the heterophasic propylene copolymer (RAHECO) has

(a) an amorphous fraction in the range of 8.0 to 15 wt.-%;

and/or

(b) melt flow rate MFR 2 (230° C.) in the range of 3.0 to 12 g/10min.

7. The injection molded article (IMA) according to claim 1 , wherein the amorphous fraction (AM) of the heterophasic propylene copolymer (RAHECO) has

(a) a comonomer content in the range of 35 to 55 mol.-%;

and/or

(b) an intrinsic viscosity (IV) in the range of 2.0 to 2.8 dl/g.

8. The injection molded article (IMA) according to claim 1 , wherein the high density polyethylene (HDPE) has density in the range of 0.940 to 0.970 g/cm 3 .

9. The injection molded article (IMA) according to claim 1 , wherein the inorganic filler (F) is talc.

10. The injection molded article (IMA) according to claim 1 , wherein the organic metal deactivator (MD) is a phenol derivative.

11. The injection molded article (IMA) according to claim 1 , wherein the sulphur containing antioxidant (SAO) is di-stearyl-thio-di-propionate (H 37 C 18 OC(O)CH 2 CH 2 SCH 2 CH 2 C(O)OC 18 H 37 ).

12. The injection molded article (IMA) according to claim 1 , wherein said injection molded article (IMA) and/or the polypropylene composition (PC) has/have a melt flow rate MFR2 (230° C.) in the range of 4.0 to 10 g/10min.

13. The injection molded article (IMA) according to claim 1 , wherein said injection molded article (IMA) is a battery case.