Heterophasic polymer composition of high stiffness
View Patent ↗The present invention relates to a heterophasic polymer composition which comprises (i) a matrix comprising a propylene homopolymer and/or a propylene copolymer having an amount of comonomer units of less than 1.0 wt %, and (ii) an elastomeric polypropylene which is dispersed within the matrix and comprises comonomer units derived from ethylene and/or a C4 to C12 alpha-olefin; and wherein the heterophasic polymer composition has an amorphous fraction AM in an amount of 2.0 to 7.5 wt %, and the amorphous fraction AM has an amount of ethylene- and/or C4 to C12 alpha-olefin-derived comonomer units of 20 to 45 wt %.
1. A heterophasic polymer composition, comprising
a matrix comprising a propylene homopolymer and/or a propylene copolymer having an amount of comonomer units of less than 1.0 wt %,
an elastomeric polypropylene which is dispersed within the matrix and comprises comonomer units derived from ethylene and/or a C4 to C12 alpha-olefin,
the heterophasic polymer composition having an amorphous fraction AM in an amount of 2.0 to 7.5 wt %, and the amorphous fraction AM having an amount of ethylene- and/or C4 to C12 alpha-olefin-derived comonomer units of 20 to 45 wt %, the heterophasic polymer composition having an amount of ethylene- and/or C4 to C12 alpha-olefin-derived comonomer units of from 0.8 wt % to less than 1.8 wt %.
2. The heterophasic polymer composition according to claim 1 , having a xylene cold soluble fraction XCS total in an amount of 3.0 to 8.5 wt %.
3. A heterophasic polymer composition, comprising
a matrix comprising a propylene homopolymer and/or a propylene copolymer having an amount of comonomer units of less than 1.0 wt %,
an elastomeric polypropylene which is dispersed within the matrix and comprises comonomer units derived from ethylene and/or a C4 to C12 alpha-olefin,
the heterophasic polymer composition having a xylene cold soluble fraction XCS total in an amount of 3.0 to 8.5 wt %, and an amount of ethylene- and/or C4 to C12 alpha-olefin-derived comonomer units of from 0.8 wt % to less than 1.8 wt %.
4. The heterophasic polymer composition according to claim 3 , having an amorphous fraction AM in an amount of 2.0 to 7.5 wt %, and the amorphous fraction AM having an amount of ethylene- and/or C4 to C12 alpha-olefin-derived comonomer units of 20 to 45 wt %.
5. The heterophasic polymer composition according to claim 3 , wherein at least 80 wt % of the matrix are made of the propylene homopolymer.
6. The heterophasic polymer composition according to claim 3 , wherein the matrix has an MFR (230° C., 2.16 kg) within the range of 0.1 g/10 min to 1.5 g/10 min.
7. The heterophasic polymer composition according to claim 1 , wherein the matrix has a xylene cold soluble fraction XCS matrix in an amount of less than 3.0 wt %.
8. The heterophasic polymer composition according to claim 1 , wherein the amount of the amorphous fraction AM in the heterophasic polymer composition is from 3.0 wt % to 7.5 wt %.
9. The heterophasic polymer composition according to claim 1 , wherein the amount of ethylene-derived comonomer units in the amorphous fraction AM of the heterophasic polymer composition is from 22 wt % to 35 wt %.
10. The heterophasic polymer composition according to claim 1 , wherein the elastomeric polypropylene represents at least 60 wt % of the amorphous fraction AM of the heterophasic polymer composition.
11. The heterophasic polymer composition according to claim 3 , wherein the amount of the xylene cold soluble fraction XCS total in the heterophasic polymer composition is from 3.0 wt % to 7.0 wt %.
12. The heterophasic polymer composition according to claim 3 , wherein the elastomeric polypropylene represents at least 60 wt % of the xylene cold soluble fraction XCS total of the heterophasic polymer composition.
13. The heterophasic polymer composition according to claim 1 , wherein the amorphous fraction AM of the heterophasic polymer composition has an intrinsic viscosity within the range of 2.0 dl/g to 5.0 dl/g.
14. A pipe, comprising a heterophasic polymer composition comprising
a matrix comprising a propylene homopolymer and/or a propylene copolymer having an amount of comonomer units of less than 1.0 wt %,
an elastomeric polypropylene which is dispersed within the matrix and comprises comonomer units derived from ethylene and/or a C4 to C12 alpha-olefin,
the heterophasic polymer composition having an amorphous fraction AM in an amount of 2.0 to 7.5 wt %, and the amorphous fraction AM having an amount of ethylene- and/or C4 to C12 alpha-olefin-derived comonomer units of 20 to 45 wt %, the heterophasic polymer composition having an amount of ethylene- and/or C4 to C12 alpha-olefin-derived comonomer units of from 0.8 wt % to less than 1.8 wt %.
15. The pipe according to claim 14 , having a tensile modulus of more than 1900 MPa, the tensile modulus being determined by the following formula:
tensile modulus=RS×12×[( D−t )/t] 3
wherein
RS is ring stiffness, determined according to EN ISO 9969,
D is the outer diameter of the pipe in mm, and
t is the wall thickness of the pipe in mm.
16. The pipe according to claim 14 , having a H50 value, determined according to EN 1411 at −10° C., of at least 1100 mm.
17. A process for the preparation of a heterophasic polymer composition, comprising the following steps:
(i) preparing a propylene homo- or copolymer in at least one loop reactor and optionally in at least one gas phase reactor,
(ii) transferring the propylene homo- or copolymer to at least one gas phase reactor and preparing an elastomeric polypropylene in the presence of the propylene homo- or copolymer,
the propylene homo- or copolymer having an amount of comonomer units of less than 1.0 wt %,
the elastomeric polypropylene having comonomer units derived from ethylene and/or a C4 to C12 alpha-olefin, and
the heterophasic polymer composition having an amorphous fraction AM in an amount of 2.0 to 7.5 wt %, and the amorphous fraction AM having an amount of ethylene- and/or C4 to C12 alpha-olefin-derived comonomer units of 20 to 45 wt %, the heterophasic polymer composition having an amount of ethylene- and/or C4 to C12 alpha-olefin-derived comonomer units of from 0.8 wt % to less than 1.8 wt %.
18. The process according to claim 17 , wherein steps (i) and (ii) are carried out in the presence of a Ziegler-Natta catalyst.
19. The process according to claim 17 , wherein step (ii) is carried out in the presence of a compound selected from the group consisting of a glycerol ester, an ethoxylated amine, an ethoxylated amide, carbon monoxide, and any combination thereof.
20. The heterophasic polymer composition according to claim 3 , wherein at least 90 wt % of the matrix are made of the propylene homopolymer.
21. The heterophasic polymer composition according to claim 1 , wherein the matrix has a xylene cold soluble fraction XCS matrix in an amount of less than 2.0 wt %.
22. The heterophasic polymer composition according to claim 1 , wherein the matrix has a xylene cold soluble fraction XCS matrix in an amount of less than 1.5 wt %.
23. The heterophasic polymer composition according to claim 1 , wherein the amount of the amorphous fraction AM in the heterophasic polymer composition is from 3.0 wt % to 6.0 wt %.
24. The heterophasic polymer composition according to claim 1 , wherein the amount of ethylene-derived comonomer units in the amorphous fraction AM of the heterophasic polymer composition is from 23 wt % to 32 wt %.
25. The heterophasic polymer composition according to claim 1 , wherein the elastomeric polypropylene represents at least 65 wt % of the amorphous fraction AM of the heterophasic polymer composition.
26. The heterophasic polymer composition according to claim 3 , wherein the amount of the xylene cold soluble fraction XCS total in the heterophasic polymer composition is from 4.0 wt % to 7.0 wt %.
27. The heterophasic polymer composition according to claim 3 , wherein the elastomeric polypropylene represents at least 65 wt % of the xylene cold soluble fraction XCS total of the heterophasic polymer composition.
28. The heterophasic polymer composition according to claim 1 , wherein the amorphous fraction AM of the heterophasic polymer composition has an intrinsic viscosity within the range of 2.5 dl/g to 5.0 dl/g.
29. The heterophasic polymer composition according to claim 1 , wherein the amorphous fraction AM of the heterophasic polymer composition has an intrinsic viscosity within the range of 3.0 dl/g to 4.5 dl/g.
30. The pipe according to claim 14 , having a tensile modulus of more than 2000 MPa, the tensile modulus being determined by the following formula:
tensile modulus=RS×12×[( D−t/t] 3
wherein
RS is ring stiffness, determined according to EN ISO 9969,
D is the outer diameter of the pipe in mm, and
t is the wall thickness of the pipe in mm.
31. The pipe according to claim 14 , having a H50 value, determined according to EN 1411 at −10° C., of at least 1500 mm.
32. The pipe according to claim 14 , having a H50 value, determined according to EN 1411 at −10° C., of at least 2000 mm.