CATALYST SYSTEM FOR POLYMERIZATION OF AN OLEFIN

• US 20160333121A1
• Filed: 12/19/2014
• Published: 11/17/2016
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: SABIC Global Technologies BV (Government of Saudi Arabia), Saudi Basic Industries Corporation (Government of Saudi Arabia)
• Original Assignee: SABIC Global Technologies BV (Government of Saudi Arabia), Saudi Basic Industries Corporation (Government of Saudi Arabia)
• Inventors: Batinas-Geurts, Aurora Alexandra, Zuideveld, Martin Alexander
• Granted Patent: US 10,640,586 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C08F 10/06 Propene
• CPC Class Codes: C08F 110/06 Propene
• CPC Class Codes: C08F 210/06 Propene
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2410/01 Additive used together with the catalyst, excluding compounds containing Al or B
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 4/6465 containing silicium
• CPC Class Codes: C08F 4/6565 and magnesium or compounds thereof

Abstract

The present invention relates to a process for the preparation of a catalyst system suitable for olefin polymerization wherein the external electron donor is n-propyltriethoxysilane, and a catalyst system obtained or obtainable by said process. The invention also relates to a process for preparing a polyolefin using said catalyst system. The invention further relates to a polyolefin, in particular polyprolyene, obtainable by such a process, and shaped articles manufactured from such a polymer. The polymers produced using the catalyst system exhibit low volatiles and therefore have a reduced environmental and health impact.

Claims

1. A process for the preparation of a catalyst system suitable for olefin polymerization, said process comprising:

providing a magnesium-based support;

optionally activating said magnesium-based support;

contacting said magnesium-based support with a Ziegler-Natta type catalytic species, and optionally one or more internal electron donors to yield a procatalyst, and

contacting said procatalyst with a co-catalyst and at least one external donor;

wherein the at least one external electron donor is n-propyltriethoxysilane.

2. The process according to claim 1, wherein the process comprises:

i) preparing a magnesium-based support by heating a carbonated magnesium compound of the formula MgR′

R″

xCO₂ wherein R′

is an alkoxide or aryloxide group, R″

is an alkoxide group, aryloxide group or halogen, and x has a value between about 0.1 and 2.0 to a temperature above 100°

C. for a period of time sufficient to cause complete loss of CO₂;

ii) contacting the resulting product with a halide of tetravalent titanium as the Ziegler-Natta type catalytic species in the presence of a halohydrocarbon and an internal electron donor; and

iii) contacting the resulting halogenated product with a tetravalent titanium halide; and

contacting said product obtained with a co-catalyst and at least one external donor;

wherein the at least one external electron donor is n-propyltriethoxysilane.

3. The process according to claim 1, wherein the process comprises preparing a magnesium-based support by

halogenating a magnesium compound of the formula MgR′

R″

, wherein R′ and

R″

are alkoxide groups containing from 1 to 8 carbon atoms, with titanium tetrachloride, in the presence of;

     1) an aromatic halohydrocarbon containing from 6 to 12 carbon atoms and from 1 to 2 halogen atoms and;

     2) a polycarboxylic acid ester derived from a branched or 4 of 12 unbranched monohydric alcohol containing from 1 to 12 carbon atoms, and

     3) a monocyclic or polycyclic aromatic compound containing from 8 to 20 carbon atoms and two carboxyl groups which are attached to ortho carbon atoms of the ring structure and

contacting the product obtained with a co-catalyst and at least one external donor;

wherein the at least one external electron donor is n-propyltriethoxysilane.

4. The process according to claim 1, wherein the process comprises:

preparing the magnesium-based support by forming a solution of a magnesium-containing species from a magnesium carbonate or a magnesium carboxylate,

precipitating solid particles from such magnesium-containing solution by treatment with a transition metal halide and an organosilane having a formula;

RnSiR′

₄″

n, wherein n=0 to 4 and wherein R is hydrogen or an alkyl, a haloalkyl or aryl radical containing one to about ten carbon atoms or a halosilyl radical or haloalkylsilyl radical containing one to about eight carbon atoms, and R′

is OR or a halogen,

reprecipitating such solid particles from a mixture containing a cyclic ether, and

contacting the product obtained with a co-catalyst and at least one external donor;

wherein the at least one external electron donor is n-propyltriethoxysilane.

5. The process according to claim 1, wherein the process comprises:

A) providing said procatalyst obtainable via a process comprising;

i) contacting a compound R⁴_zMgX⁴_2-z with an alkoxy- or aryloxy-containing silane compound to give a first intermediate reaction product, being a solid Mg(OR′

)_xX¹_2-x, wherein;

R⁴ is the same as R¹ being a linear, branched or cyclic hydrocarbyl group independently selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one or more combinations thereof;

wherein said hydrocarbyl group is substituted or unsubstituted, optionally comprises one or more heteroatoms and has between 1 and 20 carbon atoms;

X⁴ and X¹ are each independently selected from fluoride (F⁻

), chloride (Cl⁻

), bromide (Br⁻

) or iodide (I⁻

);

z is in a range of larger than 0 and smaller than 2, being 0<

z<

2;

ii) optionally contacting the solid Mg(OR¹)_xX_2-x obtained in step i) with at least one activating compound selected from activating electron donor compounds and metal alkoxide compounds of formula M¹(OR²)_v-w(OR³)_w or M²(OR²)_v-w(R³)_w, to obtain a second intermediate product;

wherein M¹ is a metal selected from Ti, Zr, Hf, Al or Si;

M² is a metal being Si;

v is the valency of M¹ or M²;

R² and R³ are each a linear, branched or cyclic hydrocarbyl group independently selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one or more combinations thereof;

wherein said hydrocarbyl group substituted or unsubstituted, optionally comprises one or more heteroatoms, and has between 1 and 20 carbon atoms;

iii) contacting the first or second intermediate reaction product, obtained respectively in step i) or ii), with a halogen-containing Ti-compound and optionally an internal electron donor to obtain said procatalyst;

B) contacting said procatalyst with a co-catalyst and at least one external electron donor being n-propyltriethoxysilane.

6. The process according to claim 1, wherein the process is essentially phthalate free.

7. The process according to claim 1, wherein an internal donor is selected from aminobenzoates represented by Formula XI:

8. Process according to claim 1, wherein the internal electron donor is selected from 4-[benzoyl(methyl)amino]pentan-2-yl benzoate;

2,2,6,6-tetramethyl-5-(methylamino)heptan-3-ol dibenzoate;

4-[benzoyl (ethyl)amino]pentan-2-yl benzoate, 4-(methylamino)pentan-2-yl bis (4-methoxy)benzoate);

3-[benzoyl(cyclohexyl)amino]-1-phenylbutyl benzoate;

3-[benzoyl(propan-2-yl)amino]-1-phenylbutyl;

4-[benzoyl(methyl)amino]-1,1,1-trifluoropentan-2-yl;

3-(methylamino)-1,3-diphenylpropan-1-ol dibenzoate;

3-(methyl)amino-propan-1-ol dibenzoate;

3-(methyl)amino-2,2-dimethylpropan-1-ol dibenzoate, and 4-(methylamino)pentan-2-yl bis-(4-methoxy)benzoate).

9. Process according to claim 1, wherein the internal electron donor is activated by an activator.

10. A catalyst system obtained by the process of claim 1.

11. A process for preparing a polyolefin, comprising contacting at least one olefin with the catalyst system of claim 10.

12. A polyolefin obtained by the process of claim 11.

14. A shaped article comprising the polyolefin according to claim 12.

15. The process according to claim 9, wherein the internal electron donor is activated by an activator, wherein the activator is a benzamide according to formula X,

16. The process according to claim 15, wherein the benzamide according to formula X is present in the procatalyst in an amount from 0.1 to 4 wt. % as determined using HPLC.

17. The process according to claim 8, wherein the internal electron donor is activated by an activator, wherein the activator is N,N-dimethylbenzamide.

18. A catalyst system obtained by the process of claim 17.

19. A process for preparing a polyolefin, comprising contacting at least one olefin with the catalyst system of claim 17.

13. A propylene homopolymer, a propylene-olefin copolymer, or a heterophasic propylene copolymer characterized by:

having a melt flow index in the range from 30 to 1000 as determined according to ISO 1133;

2005 at 230°

C. with 2.16 kg load;

a ratio of an oligomer content in ppm to the log(MFR) of less than 1650;

wherein the oligomer content is the amount of C6-C33 hydrocarbon oligomers in ppm in the polymer and is determined by thermal desorption of these oligomers from the polymer samples using an automated thermal desorption unit wherein a weighed sample of 50-100 mg of the polymer is loaded into an inert metal tube;

which tube is briefly purged at room temperature using helium and subsequently heated to 200°

C., and then a carrier gas is passed over the molten polymer sample for 30 minutes; and

upon exiting the tube, the carrier gas is passed through a cold trap, condensing the volatile components liberated from the polymer and subsequently, the cold trap is rapidly heated to 250°

C. and the volatiles are injected into a gas chromatography fitted with a dimethylpolysiloxane stationary phase column of 25 meter length for separation of the individual components, which were identified using a mass spectrometer detector and quantified using a flame ionization detector;

the oligomer content being less than 1850 ppm at log(MFR)=2.1, as determined by making a calibration line of the oligomer content of the polymer versus the log(MFR), wherein the polymer of the calibration line is produced using a Ziegler Natta catalyst and the same external donor.

20. The propylene homopolymer, the propylene-olefin copolymer, or the heterophasic propylene copolymer, wherein the melt flow index is in the range from 40 to 500, and the ratio of the oligomer content in ppm to the log(MFR) is less than 1550.