PROCESS FOR THE PREPARATION OF HIGH PURITY PROPYLENE POLYMERS

• US 20140235802A1
• Filed: 09/17/2012
• Published: 08/21/2014
• Est. Priority Date: 09/23/2011
• Status: Active Grant

• Current Assignee: Basell Poliolefine Italia Srl (Lyondellbasell Industries NV)
• Original Assignee: Basell Poliolefine Italia Srl (Lyondellbasell Industries NV)
• Inventors: Galvan, Monica, Pantaleoni, Roberto, Fusco, Ofelia, Gaddi, Benedetta, Neumann, Andreas, Mazzucco, Antonio, Collina, Gianni, Sartori, Gabriella
• Granted Patent: US 10,221,261 B2
• Time in Patent Office: Days
• US Class Current: 526/64
• CPC Class Codes: B01J 31/0204 Ethers
• CPC Class Codes: B01J 31/0209 Esters of carboxylic or carbonic acids
• CPC Class Codes: C08F 10/06 Propene
• CPC Class Codes: C08F 110/06 Propene
• CPC Class Codes: C08F 2500/04 Broad molecular weight distribution, i.e. Mw/Mn > 6
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 2500/15 Isotactic
• CPC Class Codes: C08F 4/651 Pretreating with non-metals or metal-free compounds
• CPC Class Codes: C08F 4/6543 halides of magnesium
• CPC Class Codes: C08J 2323/14 Copolymers of propene C08J2323/16 takes precedence
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets

Abstract

A process for the preparation of high purity propylene polymers carried out in the presence of a catalyst comprising the product obtained by contacting:

• • (a) a solid catalyst component comprising Mg, Ti and at least a first internal electron donor compound (HD) selected among the succinates and a second internal electron donor compound (2ID) selected among the 1,3-diethers, wherein the molar ratio of first internal donor over second internal donor 1ID:2ID is comprised between 4:6 and 9:1, with
  • (b) an organo-aluminium compound, and optionally with
  • (c) an external electron donor compound,
    said process being carried out at a temperature equal or higher than 78° C. and by employing a molar ratio of organo-aluminum compound over solid catalyst component (b):(a) of lower than 5.

Claims

1. A process for the preparation of high purity propylene (co)polymers comprising (co)polymerizing propylene in the presence of a catalyst system comprising the product obtained by contacting

(a) a solid catalyst component comprising Mg, Ti and at least a first internal electron donor compound (lID) selected among the succinates and a second internal electron donor compound (2ID) selected among the 1,3-diethers, wherein the molar ratio of first internal donor over second internal donor 1ID:

2ID is comprised between 4;

6 and 9;

1, with

(b) an organo-aluminium compound, and optionally with

(c) an external electron donor compound, said process being carried out at a temperature equal or higher than 78°

C., preferably comprised between 78°

C. and 90°

C., and by employing a weight ratio of organo-aluminum compound over propylene lower than 0.020, preferably comprised between 0.020 and 0.005 Kg/tonn.

2. The process according to claim 1, wherein the succinates for use as internal electron donor compound lID are selected from those belonging to the following formula (I):

3. The process according to any claim 1, wherein the 1,3-diethers for use as internal electron donor compound 2ID are selected from those belonging to the following formula (II):

4. The process according to claim 1, wherein the organo-aluminum compound (b) is selected among the trialkyl aluminum compounds.

5. The process according to claim 1, wherein the external electron donor compound (c) is selected among the silicon compounds of formula R_a⁵R_b⁶Si(OR⁷)_c, wherein a and b are integer from 0 to 2, c is an integer from 1 to 3 and the sum (a+b+c) is 4;

R⁵,R⁶,and R⁷,are alkyl, cycloalkyl or aryl radicals with 1-18 carbon atoms optionally containing heteroatoms.

6. The process according to claim 1, wherein the weight ratio of organo-aluminum compound over solid catalyst component (b):

(a) is lower than 5.0,

7. A propylene polymer obtainable by the process according to claim 1.

8. The propylene polymer according to claim 7, having magnesium content lower than 2 ppm.

9. The propylene polymer according to claim 6, having chlorine content lower than ⁵ ppm.

10. The propylene polymer according to claim 7, having titanium content lower than 1 ppm.

11. The propylene polymer according to claim 7, having aluminum content lower than 3 ppm.

12. The propylene polymer according to claim 7, having total ash content generally lower than 40 ppm, preferably lower than 30 ppm and more preferably lower than 20 ppm.

13. A film comprising a propylene polymer according to claim 7.

14. Use of the film according to claim 13 for dielectric capacitors.

15. Use of the film according to claim 13 for print lamination, cigarette packing.