Low emission propylene homopolymer

Patent metadata

Field	Value
Publication number	US-9896524-B2
Application number	US-201415034762-A
Country	US
Kind code	B2
Filing date	Nov 19, 2014
Priority date	Nov 22, 2013
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

Propylene homopolymer with reduced emission value.

First claim

The invention claimed is:

1. Process for producing a propylene homopolymer in a sequential polymerization process comprising at least two reactors (R1) and (R2), the propylene homopolymer having:
(a) a melt flow rate MFR 2 (230° C./2.16 kg) measured according to ISO 1133 in the range of 0.1 to 90 g/10 min; and
(b) a pentad isotacticity (mmmm) of more than 90.0% determined by 13 C-NMR, wherein further;
(c) the propylene homopolymer fulfills in equation (I):
VOC≦(MFR×2.27)+32.0

wherein,
VOC is the amount of volatile organic compounds (VOC) [in ppm] measured according to VDA 278:2002 of the propylene homopolymer;
MFR is the melt flow rate MFR 2 (230° C./2.16 kg) measured according to ISO 1133 of the propylene homopolymer; the process comprising:
producing in the first reactor (R1) and subsequently transferring into the second reactor (R2) a first propylene homopolymer fraction (H-PP1); and producing in the second reactor (R2) a second propylene homopolymer fraction (H-PP2) in the presence of the first propylene homopolymer fraction (H-PP1), and
wherein the propylene homopolymer has been polymerized in the presence of:
(a) a Ziegler-Natter catalyst (ZN-C) comprising compounds (TC) of a transition metal of group 4 to 6 of IUPAC, a Group 2 metal compound (MC), and an internal donor (ID), wherein said internal donor (ID) is a non-phthalic compound;
(b) optionally a co-catalyst (Co); and
(c) optionally an external donor (ED).

2. Process according to claim 1 , wherein the propylene homopolymer has an amount of volatile organic compounds (VOC) measured according to VDA 278:2002 of equal or below 215 ppm.

3. Process according to claim 1 , wherein the propylene homopolymer has a melting temperature Tm of equal or more than 160° C.

4. Process according to claim 1 , wherein the propylene homopolymer has a crystallization temperature of equal or more than 114° C.

5. Process according to claim 1 , wherein the propylene homopolymer has a xylene cold soluble content (XCS) determined according ISO 16152 (25° C.) of at least 1.8 wt. %.

6. Process according to claim 1 , wherein the propylene homopolymer has 2,1 erythro regio-defects of equal or below 0.4 mol. % determined by 13 C-NMR spectroscopy.

7. Process according to claim 1 , wherein the propylene homopolymer has a pentad isotacticity (mmmm) of more than 93.0% determined by 13 C-NMR.

8. Process according to claim 1 , wherein the propylene homopolymer fulfils in equation (II):
FOG≦(MFR×4.80)+100.0

wherein,
FOG is the amount of fogging compounds (FOG) [in ppm] measured according to VDA 278:2002 of the propylene homopolymer; and
MFR is the melt flow rate MFR 2 (230° C./2.16 kg) measured according to ISO 1133 of the propylene homopolymer.

9. Process according to claim 1 , wherein the propylene homopolymer has an amount of fogging compounds (FOG) measured according to VDA 278:2002 of not more than 490 ppm.

10. Process according to claim 1 , wherein the propylene homopolymer has a tensile modulus measured at 23° C. according to ISO 527-1 (cross head speed 1 mm/min) of at least 1,500 MPa.

11. Article comprising the propylene homopolymer obtained by the process according to claim 1 .

12. Process according to claim 1 , wherein:
(a) the internal donor (ID) is selected from optionally substituted malonates, maleates, succinates, glutarates, cyclohexene-1,2-dicarboxylates, benzoates and derivatives and/or mixtures thereof; and
(b) the molar-ratio of co-catalyst (Co) to external donor (ED) [Co/ED] is 5 to 45.

Assignees

• Borealis Ag

Inventors

• Wang Jingbo
• Lilja Johanna
• Horill Thomas
• Gahleitner Markus
• Denifl Peter
• Leinonen Timo

Classifications

• C08F2500/19

  Shear ratio or shear ratio index · CPC title

• C08F2500/15

  Isotactic · CPC title

• C08F2/001

  Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer (C08F295/00, C08F297/00 take precedence) · CPC title

• C08F4/16

  of silicon, germanium, tin, lead, titanium, zirconium or hafnium · CPC title

• C08F2500/12

  Melt flow index or melt flow ratio · CPC title