Propylene-ethylene random copolymer

1. Propylene random copolymer composition comprising

(A) 60-85 wt % of a copolymer of propylene and from 0.1 to 2 wt % of units derived from ethylene and having a melt flow rate value according to ISO 1133 (230° C., 2.16 kg) of from 60 to 200 g/10 min; and

(B) 15-40 wt % of a copolymer of propylene and from 7 to 17 wt % of units derived from ethylene,

said composition having a total ethylene content of from 3 to 4.5 wt %, and a melt flow rate value according to ISO 1133 (230° C., 2.16 kg) of greater than 60 to 150 g/10 min, the composition having not been subject to any form of post-reactor treatment which increases its melt flow rate by more than 5 g/10 min.

2. Composition according to claim 1 , which has a melt flow rate value of 70 to 130 g/10 min.

3. Composition according to claim 1 , which is in the form of a powder.

4. Composition according to claim 1 , wherein fraction (A) is present in an amount of 65-83 wt %.

5. Composition according to claim 1 , wherein fraction (B) is present in an amount of 17-35 wt %.

6. Composition according to claim 1 , wherein the content of units derived from ethylene in fraction (A) is 0.3-1.7 wt %.

7. Composition according to claim 1 , wherein the content of units derived from ethylene in fraction (B) is 9-16 wt %.

8. Composition according to claim 1 , wherein fraction (A) has an intrinsic viscosity η(A) of 0.6-1.0 dg/l.

9. Composition according to claim 1 , wherein the intrinsic viscosity η of the composition is 0.7-1.0 dg/l.

10. Composition according to claim 1 , wherein the intrinsic viscosity ratio of fractions (A) and (B), η(A)/η(B), is 0.6-1.25.

11. Composition according to claim 1 , wherein the moiety of hexane extractables, determined according to FDA method 177, section 1520, Annex B) on polymer formed into 100 μm thick films, is lower than 5.5 wt %.

12. Injection moulded article made from a composition as defined in claim 1 .

13. Process for producing a propylene random copolymer according to claim 1 , comprising the steps of:

(i) performing a copolymerisation of propylene and ethylene in a first stage to produce a first propylene random copolymer, and

(ii) transferring the first random copolymer to a second stage, optionally in a different reactor from the first stage, where copolymerisation is continued to prepare a second propylene random copolymer,

wherein the final polymer exiting the second stage has an MFR of 60-150 g/10 min prior to any subsequent processing.

14. Process according to claim 13 , wherein the copolymerisation is performed in the presence of a catalyst system comprising a Ziegler-Natta catalyst, an alkyl aluminium compound as cocatalyst, and a silane as external modifier.

15. Process according to claim 14 , wherein the silane has the formula Si(OR) 3 R′ or Si(OR) 4 , where R and R′ are selected independently from C 1 -C 10 alkyl and cycloalkyl groups.

16. Composition according to claim 4 , wherein fraction (A) is present in an amount of 68-82 wt %.

17. Composition according to claim 5 , wherein fraction (B) is present in an amount of 18-32 wt %.

18. Composition according to claim 6 , wherein the content of units derived from ethylene in fraction (A) is 1.0-1.7 wt %.

19. Composition according to claim 7 , wherein the content of units derived from ethylene in fraction (B) is 9-13 wt %.

20. Composition according to claim 8 , wherein fraction (A) has an intrinsic viscosity η(A) of 0.7-0.95 dg/l.

21. Composition according to claim 8 , wherein fraction (A) has an intrinsic viscosity η(A) of 0.75-0.9 dg/l.

22. Composition according to claim 9 , wherein the intrinsic viscosity η of the composition is 0.75-0.95 dg/l.

23. Composition according to claim 9 , wherein the intrinsic viscosity η of the composition is 0.8-0.9 dg/l.

24. Composition according to claim 10 , wherein the intrinsic viscosity ratio of fractions (A) and (B), η(A)/η(B), is 0.65-1.1.

25. Composition according to claim 10 , wherein the intrinsic viscosity ratio of fractions (A) and (B), η(A)/η(B), is 0.7-0.9.