Polypropylene with extreme broad molecular weight distribution

Patent metadata

Field	Value
Publication number	US-2016115258-A1
Application number	US-201414895141-A
Country	US
Kind code	A1
Filing date	Jun 10, 2014
Priority date	Jun 19, 2013
Publication date	Apr 28, 2016
Grant date	—

Abstract

Polypropylene having a melt flow rate MFR 2 (230° C.) of at least 20 g/10 min; and a Mw/Mn ratio of at least 15.0.

First claim

1 . Polypropylene having
(a) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 of at least 20 g/10 min; and (b) a ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) [Mw/Mn] of at least 15.0.

2 . Polypropylene according to claim 1 , wherein said polypropylene has
(a) a polydispersity index (PI) of at least 10.0; and/or (b) a complex viscosity ratio eta*(0.05 rad/sec)/eta*(300 rad/sec) of at least 20.0.

3 . Polypropylene having
(a) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 of at least 20 g/10 min; and (b) a complex viscosity ratio eta*(0.05 rad/sec)/eta*(300 rad/sec) of at least 20.0.

4 . Polypropylene according to claim 3 , wherein said polypropylene has
(a) a ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) [Mw/Mn] of at least 15.0; and/or (b) a polydispersity index (PI) of at least 10.0.

5 . Polypropylene according to any one of the preceding claims, wherein said polypropylene has
(a) a xylene cold soluble content (XCS) determined according ISO 16152 (25° C.) of at least 2.8 wt.-%; and/or (b) a melting temperature Tm of more than 161° C.

6 . Polypropylene according to any one of the preceding claims, wherein said polypropylene has
(a) 2.1 erythro regio-defects of equal or below 0.4 mol.-% determined by 13 C-NMR spectroscopy; and/or (b) a pentad isotacticity (mmmm) of more than 95.0 mol.-%. preferably in the range of more than 95.0 to 97.0 mol-%.

7 . Polypropylene according to any one of the preceding claims, wherein said polypropylene has
(a) a ratio of z-average molecular weight (Mz) to weight average molecular weight (Mw) [Mz/Mw] of at least 9.0; and/or (b) a ratio of z-average molecular weight (Mz) to number average molecular weight (Mn) [Mz/Mn] of at least 150.

8 . Polypropylene according to any one of the preceding claims, wherein said polypropylene is
(a) α-nucleated; and/or (b) a propylene homopolymer or a propylene copolymer, said propylene copolymer has been obtained by polymerizing propylene and at least one α-olefin., preferably one α-olefin. selected from ethylene and a C 4 to C 10 α-olefin.

9 . Polypropylene according to any one of the preceding claims, wherein said polypropylene has
(a) a weight ratio of the crystalline fractions melting in the temperature range of above 160 to 180° C. to the crystalline fractions melting in the temperature range of 90 to 160 [(>160-180)/(90-160)] of at least 3.20, wherein said fractions are determined by the stepwise isothermal segregation technique (SIST), and/or (b) a crystallization temperature of at least 125° C.; and/or (c) a tensile modulus measured according to ISO 527-2 of at least 2250 MPa.

10 . Polypropylene according to any one of the preceding claims, wherein said polypropylene has a first polypropylene fraction (PP1), a second polypropylene fraction (PP2) and a third polypropylene fraction (PP3), said first polypropylene fraction (PP1), second polypropylene fraction (PP2) and third polypropylene fraction (PP3) differ in the melt flow rate MFR 2 (230° C.) by at least 30 g/10 min.

11 . Polypropylene according to claim 10 , wherein
(a) the melt flow rate MFR 2 (230° C.) of the first polypropylene fraction (PP1) is at least 5 times higher than the melt flow rate MFR 2 (230° C.) of second polypropylene fraction (PP2); and/or (b) the melt flow rate MFR 2 (230° C.) of the second polypropylene fraction (PP2) is at least 5.000 times higher than the melt flow rate MFR 2 (230° C.) of third polypropylene fraction (PP3).

12 . Polypropylene according to claim 10 or 11 , wherein
(a) the melt flow rate MFR 2 (230° C.) of the first polypropylene fraction (PP1) is at least 200 g/10 min;
and/or
(b) the melt flow rate MFR 2 (230° C.) of the second polypropylene fraction (PP2) is in the range of 10 to below 200 g/10 min;
and/or
(c) the melt flow rate MFR 2 (230° C.) of the third polypropylene fraction (PP3) is below 0.1 g/10 min.

13 . Polypropylene according to any one of the preceding claims 10 to 12 , wherein the amount
(a) of the first polypropylene fraction (PP1) is in the range of 40 to 60 wt.-%.
(b) of the second polypropylene fraction (PP2) is in the range of 20 to 59.0 wt.-%. and
(c) of the third polypropylene fraction (PP3) is in the range of 1.0 to 15.0 wt.-%. based on the total amount of the polypropylene, preferably based on the total amount of the first polypropylene fraction (PP1), the second polypropylene fraction (PP2) and third polypropylene fraction (PP3) together.

14 . Polypropylene according to any one of the preceding claims, wherein said polypropylene has been produced according to any one of the claims 15 to 19 .

15 . Process for the manufacture of the polypropylene according to any one of the claims 1 to 14 in a sequential polymerization system comprising a pre-polymerization reactor (PR) and at least three polymerization reactors (R1), (R2) and (R3) connected in series, wherein the polymerization in the at least three polymerization reactors (R1), (R2) and (R3) takes place in the presence of a Ziegler-Natta catalyst (ZN-C), said Ziegler-Natta catalyst (ZN-C) comprises
(a) a pro-catalyst (PC) comprising a titanium compound (TC) having at least one titanium-halogen bond and an internal donor (ID), both supported on a magnesium halide;
(b) a co-catalyst (Co); and
(c) an external donor (ED);
wherein
(iv) the internal donor (ID) comprises at least 80 wt.-% of a compound selected from the group consisting of succinate, citraconate, di-ketone, enamino-imine, and mixtures thereof preferably comprises at least 80 wt.-% of a succinate;
(v) the mol-ratio of co-catalyst (Co) to external donor (ED) [Co/ED] of said Ziegler-Natta catalyst (ZN-C) is below 20.0; and
(vi) said Ziegler-Natta catalyst (ZN-C) is present in the pre-polymerization reactor (PR) and
propylene (C 3 ) and optionally hydrogen (H 2 ) is fed to said pre-polymerization reactor (PR) in a H 2 /C 3 feed ratio of 0.00 to 0.10 mol/kmol.

16 . Process according to claim 15 , wherein
(a) the mol-ratio of co-catalyst (Co) to titanium compound (TC) (TC) [Co/TC] is at most 130, and/or (b) the mol-ratio of external donor (ED) to titanium compound (TC)) [Co/TC] is below 50.

17 . Process according to claim 15 or 16 , wherein
(a) the operating temperature in the pre-polymerization reactor (PR) is in the range of more than 20° C. to 80° C.;
and/or
(b) the average residance time of the Ziegler-Natta catalyst (ZN-C) in the pre-polymerization reactor (PR) is in the range of more than 3 to 20 min.

18 . Process according to any one of the preceding claims 12 to 17 , wherein
(a) the average residence time in the first polymerization reactor (R1) is at least 20 min;
and/or
(b) the average residence time in the second polymerization reactor (R2) is at least 30 min;
and/or
(c) the average residence time in the third polymerization reactor (R3) is at least 80 min.
and/or
(d) the total residence time in the three polymerization reactors (R1), (R2) and (R3) together is at most 700 min, preferably 150 to 700 min.

19 . Process according to any one of the preceding claims 12 to 18 , wherein
(a) the feed ratio of hydrogen (H 2 ) to propylene (C 3 ) [H 2 /C 3 ] in the first polymerization reactor (R1) is in the range of 10 to 60 mol/kmol;
and/or
(b) the feed ratio of hydrogen (H 2 ) to propylene (C 3 ) [H 2 /C 3 ] in the second polymerization reactor (R2) is in the range of 10 to 260 mol/kmo

Assignees

• Borealis Ag

Inventors

• Hafner Norbert
• Bernreitner Klaus
• Gahleitner Marcus

Classifications

• C08L23/12 Primary

  Polypropene · CPC title

• C08F10/06 Primary

  Propene · CPC title

• C08L23/10

  Homopolymers or copolymers of propene · CPC title

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title