Polymer composition

1. A composition formed from a first mixture of components comprising;

(i) a first amount of an aromatic polycarbonate having a weight average molecular weight (Mw) of greater than or equal to 20,000 Da;

(ii) a second amount of a graft copolymer comprising polyacrylonitrile;

(iii) 3 to 25 wt % of a non-crosslinked acrylic polymer obtained by polymerizing monomers consisting of 60 to 100% by weight methyl methacrylate monomer and 0 to 40% by weight of one or more alkyl (alk)acrylate comonomers, and having a weight average molecular weight (Mw) of between greater than or equal to 25,000 Daltons (Da) and less than 50,000 Daltons (Da); and

(iv) an acrylic based impact modifier or a methacrylate-butadiene-styrene (MBS) based impact modifier.

2. The composition of claim 1 , wherein the non-crosslinked acrylic polymer has a weight average molecular weight (Mw) of greater than or equal to 30,000 Da.

3. The composition of claim 2 , wherein the non-crosslinked acrylic polymer has a weight average molecular weight (Mw) of greater than or equal to 35,000 Da.

4. The composition of claim 1 , wherein the non-crosslinked acrylic polymer comprises an acrylic copolymer obtained by polymerising 60 to 99.9% by weight of methyl methacrylate monomer and 0.1 to 40% by weight of one or more alkyl (alk)acrylate comonomers.

5. The composition of claim 4 , wherein the acrylic copolymer is obtained by polymerising 80 to 99% by weight of methyl methacrylate monomer and 20 to 1% by weight of one or more alkyl (alk)acrylate comonomers.

6. The composition of claim 4 , wherein the acrylic copolymer is obtained by polymerising 90 to 99% by weight of methyl methacrylate monomer and 10 to 1% by weight, of one or more alkyl (alk)acrylate comonomers.

7. The composition of claim 4 , wherein the alkyl (alk)acrylate comonomer of the acrylic copolymer comprises one or more alkyl acrylate comonomer.

8. The composition of claim 7 , wherein the one or more alkyl acrylate comonomers of the acrylic copolymer comprises one or more C 1 to C 8 alkyl acrylate comonomers.

9. The composition of claim 8 , wherein the one or more C 1 to C 8 alkyl acrylate comonomers are selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate and mixtures thereof.

10. The composition of claim 5 , wherein the acrylic copolymer consists essentially of methyl methacrylate monomer and one or more alkyl acrylate comonomers.

11. The composition of claim 7 , wherein the acrylic copolymer comprises only one alkyl acrylate comonomer.

12. The composition of claim 1 , wherein the non-crosslinked acrylic polymer is present in an amount of greater than or equal to 5% by weight, based on the total weight of the composition.

13. The composition of claim 1 , wherein the non-crosslinked acrylic polymer is present in an amount of less than or equal to 20% by weight, based on the total weight of the composition.

14. The composition of claim 1 , wherein the graft copolymer comprising polyacrylonitrile comprises an acrylic-styrene-acrylonitrile (ASA) polymer, acrylonitrile-EPDM-styrene (AES) polymer, olefin-styrene-acrylonitrile (OSA) polymer or acrylonitrile-butadiene-styrene (ABS) polymer.

15. The composition of claim 14 , wherein the graft polymer comprising polyacrylonitrile comprises an ASA polymer, an AES polymer or an ABS polymer.

16. The composition of claim 14 , wherein the graft polymer comprising polyacrylonitrile comprises an ABS polymer.

17. The composition of claim 1 , wherein the graft copolymer comprising polyacrylonitrile is present in an amount of greater than or equal to 0.5% by weight, based on the total weight of the composition.

18. The composition of claim 1 , wherein the graft copolymer comprising polyacrylonitrile is present in an amount of greater than or equal to 2% by weight, based on the total weight of the composition.

19. The composition of claim 1 , wherein the graft copolymer comprising polyacrylonitrile is present in an amount of less than or equal to 60% by weight, based on the total weight of the composition.

20. The composition of claim 1 , wherein the graft copolymer comprising polyacrylonitrile is present in an amount of less than or equal to 40% by weight, based on the total weight of the composition.

21. The composition of claim 1 , wherein the aromatic polycarbonate is derived from a bis-phenol.

22. The composition of claim 21 , wherein the aromatic polycarbonate is derived from 2,2-bis-(4-hydroxyphenyl)-propane (bisphenol A).

23. The composition of claim 1 , wherein the aromatic polycarbonate is present in an amount of greater than or equal to 30% by weight, based on the total weight of the composition.

24. The composition of claim 23 , wherein the aromatic polycarbonate is present in an amount of greater than or equal to 35% by weight, based on the total weight of the composition.

25. The composition of claim 1 , wherein the aromatic polycarbonate is present in an amount of less than or equal to 90% by weight, based on the total weight of the composition.

26. The composition of claim 25 , wherein the aromatic polycarbonate is present in an amount of less than or equal to 85% by weight, based on the total weight of the composition.

27. The composition of claim 1 , wherein the ratio by weight of the aromatic polycarbonate to the weight of the graft copolymer comprising polyacrylonitrile is 90:1 to 0.5:1.

28. The composition of claim 27 , wherein the ratio by weight of the aromatic polycarbonate to the weight of the graft copolymer comprising polyacrylonitrile is 40:1 to 0.75:1.

29. The composition of claim 28 , wherein the ratio by weight of the aromatic polycarbonate to the weight of the graft copolymer comprising polyacrylonitrile is 10:1 to 1:1.

30. The composition of claim 1 , wherein the impact modifier comprises a MBS based impact modifier.

31. The composition of claim 1 , wherein the impact modifier is in the form of core-shell polymeric particles.

32. The composition of claim 1 , wherein the impact modifier is present in an amount of greater than or equal to 1% by weight, based on the total weight of the composition.

33. The composition of claim 32 , wherein the impact modifier is present in an amount of greater than or equal to 3% by weight, based on the total weight of the composition.

34. The composition of claim 1 , wherein the impact modifier is present in an amount of less than or equal to 20% by weight, based on the total weight of the composition.

35. The composition of claim 34 , wherein the impact modifier is present in an amount of less than or equal to 15% by weight, based on the total weight of the composition.

36. The composition of claim 1 , wherein the Melt Flow Index of the composition at 260° C. applying a 5 kg/cm 3 load as determined in accordance with ISO 1133:1997 is at least 5% greater than a comparable composition containing an equivalent level of aromatic polycarbonate and not including the non-crosslinked acrylic polymer.

37. The composition of claim 1 for use in melt-processing applications.

38. The composition of claim 1 , further comprising a reinforcement fibre.

39. A process for manufacturing the composition of claim 1 comprising:

mixing the aromatic polycarbonate, the graft copolymer comprising polyacrylonitrile, the non-crosslinked acrylic polymer, and the acrylic based impact modifier or a methacrylate-butadiene-styrene (MBS) based impact modifier.

40. The process of claim 39 , wherein the mixing comprises melt blending the aromatic polycarbonate, the graft copolymer comprising polyacrylonitrile, the non-crosslinked acrylic polymer and the acrylic based impact modifier or methacrylate-butadiene-styrene (MBS) based impact modifier.

41. An article comprising the composition of claim 1 .

42. A method of manufacturing an article comprising

adding the composition of claim 1 in molten form to a mould,

allowing the molten composition to solidify in the mould to form the article and removing the article from the mould.

43. A method of forming an article comprising injection moulding the composition of claim 1 .

44. A method for increasing the melt flow rate of a mixture comprising

adding 3 to 25 wt % of a non-crosslinked acrylic polymer obtained by polymerizing monomers consisting of 60 to 100% by weight methyl methacrylate monomer and 0 to 40% by weight of one or more alkyl (alk)acrylate comonomers, and having a weight average molecular weight (Mw) of between greater than or equal to 25,000 Daltons (Da) and less than 50,000 Daltons (Da) to an aromatic polycarbonate having a weight average molecular weight (Mw) of greater than or equal to 20,000 Da, a graft copolymer comprising polyacrylonitrile, and an acrylic based impact modifier or a methacrylate-butadiene-styrene (MBS) based impact modifier.

45. The method of claim 44 , further comprising a reinforcement fibre.

46. A method for decreasing the process cycle time in moulding applications of a mixture of components comprising:

adding 3 to 25 wt % of a non-crosslinked acrylic polymer obtained by polymerizing monomers consisting of 60 to 100% by weight methyl methacrylate monomer and 0 to 40% by weight of one or more alkyl (alk)acrylate comonomers, and having a weight average molecular weight (Mw) of between greater than or equal to 25,000 Daltons (Da) and less than 50,000 Daltons (Da) to an aromatic polycarbonate having a weight average molecular weight (Mw) of greater than or equal to 20,000 Da, a graft copolymer comprising polyacrylonitrile, and an acrylic based impact modifier or a methacrylate-butadiene-styrene (MBS) based impact modifier.

47. The method of claim 46 , wherein the mixture further comprises a reinforcement fibre.

48. A method of increasing the melt flow rate of a mixture of components comprising melt bending 3 to 25 wt % of a non-crosslinked acrylic polymer obtained by polymerizing monomers consisting of 60 to 100% by weight methyl methacrylate monomer and 0 to 40% by weight of one or more alkyl (alk)acrylate comonomers, and having a weight average molecular weight (Mw) of between greater than or equal to 25,000 Daltons (Da) and less than 50,000 Daltons (Da) with an aromatic polycarbonate having a weight average molecular weight (Mw) of greater than or equal to 20,000 Da, a graft copolymer comprising poly polyacrylonitrile, and an acrylic based impact modifier or a methacrylate-butadiene-styrene (MBS) based impact modifier.

49. The method of claim 48 , further comprises mixing in a reinforcement fibre.

50. A method of decreasing the process cycle time for forming an article in injection moulding applications from a mixture of components comprising:

adding 3 to 25 wt % of a non-crosslinked acrylic polymer obtained by polymerizing monomers consisting of 60 to 100% by weight methyl methacrylate monomer and 0 to 40% by weight of one or more alkyl (alk)acrylate comonomers, and having a weight average molecular weight (Mw) of between greater than or equal to 25,000 Daltons (Da) and less than 50,000 Daltons (Da) to an aromatic polycarbonate having a weight average molecular weight (Mw) of greater than or equal to 20,000 Da, a graft copolymer comprising poly polyacrylonitrile, and an acrylic based impact modifier or a methacrylate-butadiene-styrene (MBS) based impact modifier to form the mixture; and

forming the article from the mixture by an injection moulding procedure.

51. The method of claim 50 , wherein the mixture further comprising a reinforcement fibre.