Process for producing polypropylene

Patent metadata

Field	Value
Publication number	US-10626199-B2
Application number	US-201515539112-A
Country	US
Kind code	B2
Filing date	Dec 21, 2015
Priority date	Dec 22, 2014
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

Propylene is polymerised in the presence of a polymerisation catalyst comprising a solid catalyst component, an organoaluminium compound and an external electron donor, the process comprising the steps of (i) contacting propylene and hydrogen with the polymerisation catalyst in polymerisation conditions in a polymerisation reactor to produce a polymer of propylene; (ii) recovering the polymer of propylene from the polymerisation reactor; wherein the polymer of propylene has MFR of from more than 100 to 10000 g/10 min. The solid catalyst component comprises titanium, magnesium, halogen and an internal electron donor, characterised in that the internal electron donor is a compound according to formula (I):

First claim

The invention claimed is:

1. A process for polymerising propylene in the presence of a polymerisation catalyst comprising a solid catalyst component, an organoaluminium compound and an external electron donor, the process comprising the steps of (i) contacting propylene and hydrogen with the polymerisation catalyst in polymerisation conditions in a polymerisation reactor to produce a polymer of propylene; (ii) recovering the polymer of propylene from the polymerisation reactor; wherein the polymer of propylene has MFR 2 of from more than 100 to 10000 g/10 min; and the solid catalyst component comprises titanium, magnesium, halogen and an internal electron donor, characterised in that the internal electron donor is a compound according to formula (I):

with R 1 and R 2 being the same or different and being a linear or branched C 1 -C 12 -alkyl group, and with R being H or a linear, branched or cyclic C 1 to C 12 -alkyl; and the external electron donor is a silane compound having the formula Si(OR 11 ) n R 10 4-n , wherein n is 2 or 3, each R 11 is independently a linear or branched C 1 -C 4 alkyl; each R 10 is independently a linear or branched alkyl group having from 1 to 24 carbon atoms and optionally containing an atom of group 15 of periodic table of elements or comprises a cyclic group having from 6 to 12 carbon atoms, and the finally obtained catalyst particles have surface areas below 20 m 2 /g.

2. The process according to claim 1 wherein R 1 and R 2 are a linear or branched C 1 -C 8 -alkyl group.

3. The process according to claim 1 wherein R 1 and R 2 are the same.

4. The process according to claim 1 wherein R is a linear or branched C 1 to C 3 -alkyl.

5. The process according to claim 4 wherein R is methyl.

6. The process according to claim 1 wherein each R 10 is independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, tert-butyl, cyclohexyl and phenyl.

7. The process according to claim 1 wherein each R 10 is independently selected from the group consisting of methyl, ethyl, iso-butyl or cyclohexyl.

8. The process according to claim 6 wherein n is 2.

9. The process according to claim 1 wherein the polymerisation is conducted as a slurry polymerisation in a loop reactor wherein solid polymer particles are suspended in a fluid phase in said loop reactor.

10. The process according to claim 9 wherein the ratio of hydrogen concentration to propylene concentration in the fluid phase in the loop reactor is from 3 to 40 mol/kmol and the polymer of propylene has MFR 2 of from 100 to 2000 g/10 min.

11. The process according to claim 9 comprising the additional steps of passing the polymer of propylene recovered from the polymerisation reactor into a subsequent polymerisation reactor together with additional propylene and at least one comonomer selected from the group consisting of ethylene, linear 1-alkenes having 4 to 10 carbon atoms and mixtures thereof, to produce a copolymer of propylene comprising a semicrystalline matrix and a predominantly non-crystalline copolymer of propylene with the at least one comonomer.

12. A process for polymerising propylene in the presence of a polymerisation catalyst comprising a solid catalyst component, an organoaluminium compound and an external electron donor, the process comprising the steps of (i) contacting propylene and hydrogen with the polymerisation catalyst in polymerisation conditions in a polymerisation reactor to produce a polymer of propylene; (ii) recovering the polymer of propylene from the polymerisation reactor; wherein the polymer of propylene has MFR 2 of from more than 100 to 10000 g/10 min; and the solid catalyst component comprises titanium, magnesium, halogen and an internal electron donor, characterised in that the internal electron donor is a compound according to formula (I):

with R 1 and R 2 being the same or different and being a linear or branched C1-C12-alkyl group, and with R being H or a linear, branched or cyclic C1 to C12-alkyl; and the external electron donor is a silane compound having the formula Si(OR 11 ) n R 10 4-n , wherein n is 2 or 3, each R 11 is independently a linear or branched C1-C4 alkyl; and each R 10 is independently NR 12 R 13 and R 12 and R 13 are independently selected from the group consisting of methyl, ethyl, n-propyl, n-butyl, octyl, decanyl, iso-propyl, iso-butyl, iso-pentyl, tert-butyl, tert-amyl, cyclohexyl, methylcyclopentyl and cycloheptyl, and
the finally obtained catalyst particles have surface areas below 20 m 2 /g.

13. The process according to claim 12 wherein R 12 and R 13 are ethyl.

14. The process according to claim 12 wherein n is 3.

15. The process according to claim 12 wherein R 11 is the same and is selected from the group consisting of methyl and ethyl.

Assignees

• Borealis Ag

Inventors

• Leskinen Pauli
• Lilja Johanna
• Wang Jingbo
• Gahleitner Markus
• Horill Thomas
• Denifl Peter
• Tranninger Cornelia

Classifications

• C08F110/06 Primary

  Propene · CPC title

• C08F4/6546

  organo-magnesium compounds · CPC title

• C08F2500/12

  Melt flow index or melt flow ratio · CPC title

• C08F2500/04

  Broad molecular weight distribution, i.e. Mw/Mn > 6 · CPC title

• C08F4/6465

  containing silicium · CPC title