Polymer composition comprising inorganic compound and polymeric impact modifier and a process for preparing the same

1. A polymer composition P1 comprising:

a) from 29 wt % to 60 wt % of an inorganic mineral compound (F), wherein the inorganic compound (F) consists of a mineral filler (F 1 ) and a flow aid (F 2 ), wherein the weight ratio (F 1 )/(F 2 ) is at least 5/1;

b) from 40 wt % 71 wt % of a polymeric impact modifier (IM1) which is a polymer particle having a multilayer structure comprising at least one layer (IM 1 L 1 ) having a glass transition temperature below 0° C. and at least another layer (IM1L 2 ) having a glass transition temperature over 45° C., wherein the weight ratio of layer (IM1L1)/layer (IM 1 L 2 ) in the multistage polymer is in a range by weight between 85/15 and 97/3;

wherein the two components of a) and b) add up to 100 wt %, the ratio of the two components a) and b) being calculated only from the sum of these two components,

and wherein polymer composition P1 is a powder having volume median particle size D50 between 1 μm and 500 μm.

2. The composition according to claim 1 comprising

a) between 31 wt % and 59 wt % of an inorganic compound (F),

b) between 41 wt % and 69 wt % a polymeric impact modifier (IM1).

3. The composition according to claim 1 comprising

a) between 33 wt % and 58 wt % of an inorganic compound (F),

b) between 42 wt % and 67 wt % a polymeric impact modifier (IM1).

4. The composition according to claim 1 comprising

a) between 40 wt % and 55 wt % of an inorganic compound (F),

b) between 45 wt % and 60 wt % a polymeric impact modifier (IM1).

5. The composition according to claim 1 comprising

a) between 42 wt % and 47 wt % of an inorganic compound (F),

b) between 53 wt % and 58 wt % a polymeric impact modifier (IM1).

6. The composition according to claim 1 , wherein each powder particle comprises the compounds of a) and b).

7. The composition according to claim 1 , wherein a sample of 1 g or less taken from a quantity of 1 kg of the polymeric composition P1 has a variation of less than 30% relative to the global composition of P1 concerning the weight ratio of the two respective components of a) and b).

8. The composition according to claim 1 , wherein the weight ratio of layer (IM1L1)/layer (IM1L2) in the multistage polymer is at least 86/14.

9. The composition according to claim 1 , wherein the weight ratio of layer (IM1L1)/layer (IM1L2) in the multistage polymer is in a range by weight between 86/14 and 97/3.

10. The composition according to claim 1 , wherein layer IM1L1 comprises polymer L1 and the polymer L1 presents more than 85 wt % of the polymeric impact modifier (IM1).

11. The composition according to claim 1 , wherein layer IM1L1 comprises polymer L1 and the polymer L1 presents more than 86 wt % of the polymeric impact modifier (IM1).

12. The composition according to claim 1 , wherein layer IM1L1 comprises polymer L1 and the polymer (L1) has a glass transition temperature below 0° C. and is a (meth) acrylic polymer comprising at least 50 wt % of monomers from alkyl acrylates.

13. The composition according to claim 1 wherein at least a part of the mineral filler (F 1 ) is a mineral filler chosen from the group consisting of calcium carbonate, calcinated clay, silica (fumed or precipitated), clay, Montmorillonite (nano-clay), zeolite, perlite, and titanium dioxide.

14. The composition according to claim 1 wherein the mineral filler (F 1 ) is calcium carbonate.

15. A process for preparing the polymeric composition P1 of claim 1 , said process comprising the step of:

blending the components of a) and b), while the component of b) and at least 83.33 wt % of compound a) are in form of a dispersion in aqueous phase during the blending step.

16. The process according to claim 15 , wherein the polymeric composition P1 comprises,

a) between 31 wt % and 59 wt % of an inorganic compound (F), and

b) between 41 wt % and 69 wt % a polymeric impact modifier (IM1).

17. The process according to claim 15 , wherein said process comprises the steps of:

i) blending the two components of a) and b), while the two components are in form of a dispersion in aqueous phase during the blending step, and

ii) drying the blend obtained in step i).

18. The process for preparing a polymeric composition P2 comprising polymer composition P1 according to claim 1 ,

said polymeric composition P2 comprises also

d) a thermoplastic polymer TP1,

said process comprises the step of:

blending the compositions P1 and the thermoplastic polymer TP1.

19. An article comprising processed polymer composition P2 according to claim 18 , wherein the article is a profile, a pipe, a siding, a foam, a film, a sheet, a flooring film or sheet.