Polypropylene homopolymers with high heat deflection temperature, high stiffness and flowability

1. A polypropylene composition comprising a polypropylene base resin, the polypropylene base resin having

lamellas of a thickness from 24.2 nm to 84.6 nm in an amount of at least 40% when measured by stepwise isothermal segregation technique (SIST); and

a molecular weight distribution broadness Mw/Mn as calculated from gel permeation chromatography according to ISO 16014-4 2003, of at least 5, and

a weight average molecular weight Mw of 130,000 g/mol or lower determined by GPC according to ISO 16014-4 2003; and

the polypropylene composition having an MFR 2 measured according to ISO 1133 (230° C., 2.16 kg load) of at least 50 g/10 min; and

a tensile modulus of 2000 MPa or higher when measured according to ISO 527-2 using injection moulded test specimens T as described in EN ISO 1873-2 (dog bone shape, 4 mm thickness).

2. The polypropylene composition according to claim 1 , wherein the polypropylene base resin has a melting temperature of at least 162° C. according to DSC analysis.

3. The polypropylene composition according to claim 1 , wherein the polypropylene base resin has a xylene soluble content XS (23° C., ISO 6427) is 2.5 wt.-% or lower.

4. The polypropylene composition according to claim 1 , wherein the pentad isotacticity when measured by NMR is higher than 97%.

5. The polypropylene composition according to claim 1 , wherein the crystallization temperature T CR as measured by DSC is 125° C. or higher.

6. The polypropylene composition according to claim 1 , wherein the polypropylene base resin has a molecular weight distribution broadness Mw/Mn of 5 to 8 determined by GPC according to ISO 16014-4 2003.

7. The polypropylene composition according to claim 1 , wherein the polypropylene base resin is a homopolymer.

8. Polypropylene composition obtained by a process comprising

polymerizing propylene in the presence of a catalyst system including (i) a Ziegler Natta catalyst and (ii) diethylaminomethyl triethoxysilane

or dicyclopentane dimethoxysilane (CD P PDMS) as an external donor;

wherein the mole ratio of aluminum in the catalyst system to the external donor is in the range of 5 to 30,

whereby,

(i) a first intermediate polypropylene with an MFR 2 of 200 g/10 min to 2000 g/10 min (ISO 1133; 230° C., 2.16 kg load) is formed in a first reaction zone;

(ii) the first intermediate polypropylene is further polymerized in a second reaction zone to form a second intermediate polypropylene having an MFR 2 of 80 to 800 g/10 min or higher (ISO 1133; 230° C., 2.16 kg load);

(iii) the second intermediate polypropylene is further polymerized in a third reaction zone to form the third intermediate polypropylene having an MFR 2 of 50 to 300 g/10 min or higher (ISO 1133; 230° C., 2.16 kg load);

and optionally compounding the third intermediate polypropylene to form the polypropylene composition having an MFR 2 of 50 to 300 g/10 min or higher (ISO 1133; 230° C., 2.16 kg load) and a tensile modulus of 2000 MPa or higher when measured according to ISO 527-2 using injection moulded test specimens T as described in EN ISO 1873-2 (dog bone shape, 4 mm thickness),

the polypropylene composition comprising a polypropylene base resin having a molecular weight distribution broadness M W /M n as calculated from gel permeation chromatography according to ISO 16014-4 2003, of at least 5.

9. The polypropylene composition according to claim 8 , wherein 30 to 70 wt.-% of the third intermediate polypropylene is produced in the first reaction zone; and

optionally wherein 20 to 25 wt.-% of the third intermediate polypropylene is produced in the second reaction zone; and

optionally wherein 10 to 25 wt.-% of the third intermediate polypropylene is produced in the third reaction zone.

10. Process for the production of a polypropylene composition and a tensile modulus of 2000 MPa or higher when measured according to ISO 527-2 using injection moulded test specimens T as described in EN ISO 1873-2 (dog bone shape, 4 mm thickness) in the presence of a catalyst system including a Ziegler Natta catalyst and diethylaminomethyl triethoxysilane

as an external donor, whereby the mole ratio of aluminum in the catalyst system to the external donor is in the range of 5 to 30,

whereby,

(i) a first intermediate polypropylene with an MFR 2 of 200 g/10 min to 2000 g/10 min (ISO 1133; 230° C., 2.16 kg load) is formed in a first reaction zone;

(ii) the first intermediate polypropylene is further polymerized in a second reaction zone to form a second intermediate polypropylene having an MFR 2 of 80 to 800 g/10 min or higher (ISO 1133; 230° C., 2.16 kg load);

(iii) the second intermediate polypropylene is further polymerized in a third reaction zone to form the third intermediate polypropylene having an MFR 2 of 50 to 300 g/10 min or higher (ISO 1133; 230° C., 2.16 kg load);

and optionally compounding the third intermediate polypropylene to form the polypropylene composition having an MFR 2 of 50 to 300 g/10 min or higher (ISO 1133; 230° C., 2.16 kg load);

the polypropylene composition comprising a polypropylene base resin having a molecular weight distribution broadness M W /M n as calculated from gel permeation chromatography according to ISO 16014-4 2003, of at least 5.

11. Process according to claim 10 , whereby external donor is fed to the second reaction zone and/or the third reaction zone.

12. A composition of matter comprising a polypropylene composition and a filler,

the polypropylene composition comprising a polypropylene base resin, the polypropylene base resin having

a weight average molecular weight Mw of 130,000 g/ml or lower as determined by GPC according to ISO 16014-4 2003;

lamellas of a thickness from 24.2 nm to 84.6 nm in an amount of at least 40% when measured by stepwise isothermal segregation technique (SIST); and

a molecular weight distribution broadness Mw/Mn as calculated from gel permeation chromatography according to ISO 16014-4 2003, of at least 5, and

the polypropylene composition having an MFR 2 measured according to ISO 1133 (230° C., 2.16 kg load) of at least 50 g/10 min; and

a tensile modulus of 2000 MPa or higher when measured according to ISO 527-2 using injection moulded test specimens T as described in EN ISO 1873-2 (dog bone shape, 4 mm thickness).

13. A composition of matter according to claim 12 , wherein the filler is a fiber optionally selected from glass fibers and carbon fibers.

14. A composition of matter according to claim 12 , wherein the filler is talc.

15. A composition according to claim 1 characterized by having increased temperature resistance.