Supported donor modified ziegler-natta catalysts

Abstract

Procatalyst comprising an inorganic support, a chlorine compound carried on said support, a magnesium compound carried on said support, a titanium compound carried on said support, and a compound comprising two oxygen containing rings, wherein said two rings are linked via a bridge selected from the group consisting of carbon bridge, silicon bridge, ethane-1.2-diyl bridge, ethene-1,2-diyl bridge, alkylaminomethyl bridge and imine bridge.

Claims

1. A process for producing a procatalyst, wherein the process comprises the steps in the order of: (a) contacting an inorganic support (IS) with an an alkyl metal chloride (AMC) to obtain a first reaction product (1.sup.st RP), (b) contacting said first reaction product (1.sup.st RP) with an electron donor compound (ED) to obtain a second reaction product (2.sup.nd RP), (c1) contacting said second reaction product (2.sup.nd RP) with a compound (M) or mixture (MI) to obtain a third reaction product (3.sup.rd RPa) and subsequently contacting said third reaction product (3.sup.rd RPa) with a titanium compound (TC) to obtain the procatalyst, or (c2) contacting said second reaction product (2.sup.nd RP) with a titanium compound (TC) to obtain a third reaction product (3.sup.rd RPb) and subsequently contacting said third reaction product (3.sup.rd RPb) with a compound (M) or mixture (MI) to obtain the procatalyst, or (c3) contacting said second reaction product (2.sup.nd RP) simultaneously with a compound (M) and a titanium compound (TC) or with a mixture (MI) and a titanium compound (TC) to obtain the procatalyst, or (c4) contacting said second reaction product (2.sup.nd RP) with a mixture of compound (M) and a titanium compound (TC) or with a mixture of a mixture (MI) and a titanium compound (TC) to obtain the procatalyst, wherein: (i) the alkyl metal chloride (AMC) is of formula (I):
R.sub.nMeCl.sub.3-n(I) wherein: R is a C.sub.1-C.sub.20 alkyl group, Me is a metal of group 13 of the Periodic Table, and n is 1 or 2, (ii) the compound (M) and the mixture (MI) comprise a hydrocarbyl and/or hydrocarbyl oxide linked to magnesium, (iii) the titanium compound (TC) is of formula (III):
(OR).sub.4-xTiCl.sub.x(III) wherein: R is a C.sub.2-C.sub.20 hydrocarbyl group and x is an integer of 3 or 4, and (iv) the electron donor compound (ED) is a compound (C) comprising two oxygen-containing rings, wherein said two rings are linked via a bridge selected from the group conisting of carbon bridge, silicon bridge, ethane-1,2-diyl bridge, ethene-1,2-diyl bridge, alkylaminomethyl bridge and imine bridge.

2. The process according to claim 1, wherein the compound (C) is of formula (IV): ##STR00009## wherein: Y is selected from the group consisting of C(R.sub.1).sub.2, Si(R.sub.1).sub.2, CHR,.sub.1CHR.sub.1, CR.sub.1CR.sub.1, CHR.sub.1NR.sub.1, and CR.sub.1N, wherein each R.sub.1 can be the same or different and can be hydrogen, a linear or branched C.sub.1 to C.sub.8-alkyl group, or a C.sub.2-C.sub.8-alkylene group, or two of R.sub.1 can form together an optionally substituted aliphatic 3 to 6 membered ring with the C or Si-atoms they are attached to and R.sub.2, R.sub.3, R.sub.3, R.sub.4, R.sub.4, R.sub.5 and R.sub.5 are the same or different and can be hydrogen, a linear or branched C.sub.1to C.sub.8-alkyl, or a C.sub.3-C.sub.8-alkylene group, wherein two or more of R.sub.2, R.sub.3, R.sub.3, R.sub.4, R.sub.4, R.sub.5 and R.sub.5 can form a ring, or any two neighbored R.sub.2, R.sub.3, R.sub.4 and R.sub.5 can represent a double bond, and optionally at least one of the C-atoms in the oxygen-containing rings can be replaced by a heteroatom selected from O, N and P.

3. The process according to claim 2, wherein: Y is C(R.sub.1).sub.2 or Si(R.sub.1).sub.2, R.sub.1 are the same and are a linear or branched C.sub.1 to C.sub.5-alkyl group, R.sub.2, R.sub.3, R.sub.3, R.sub.4, R.sub.4, R.sub.5 and R.sub.5 are the same or different and can be hydrogen, linear or branched C.sub.1 to C.sub.5-alkyl group.

4. The process according to claim 1, wherein the compound (C) is 2,2-di(2-tetrahydrofuryl)propane (DTHFP).

5. The process according to claim 1, wherein the inorganic support (IS) is an inorganic oxide having surface hydroxyl groups.

6. The process according to claim 1, wherein the metal Me of the alkyl metal chloride (AMC) of formula (I) is Al.

7. The process according to claim 1, wherein the compound (M) is of formula (II) and the mixture (MI) comprises a mixture of compounds of formula (II), wherein formula (II) is:
Mg(R).sub.n(OR).sub.2-n, where n is 0, 1 or 2, each R can be the same or different hydrocarbyl group of 1 to 20 C atoms.

8. The process according to claim 1, wherein the molar ratio of ED/Mg is 0.01 to below 0.40.

9. A procatalyst comprising: (a) an inorganic support (IS), (b) a chlorine compound carried on said support, (c) a magnesium compound carried on said support, (d) a titanium compound carried on said support, and (e) an electron donor compound (ED) being a compound (C) comprising two oxygen containing rings, wherein said two rings are linked via a bridge selected from the group consisting of carbon bridge, silicon bridge, ethane-1,2-diyl bridge, ethene-1,2-diyl bridge, alkylaminomethyl bridge and imine bridge, wherein the procatalyst is produced according to claim 1.

10. The procatalyst according to claim 9, wherein the compound (C) is of formula (IV): ##STR00010## wherein: Y is selected from the group consisting of C(R.sub.1).sub.2, Si(R.sub.1).sub.2, CHR.sub.1CHR.sub.1, CR.sub.1CR.sub.1, CHR.sub.1NR.sub.1, and CR.sub.1N, wherein each R.sub.1 can be the same or different and can be hydrogen, a linear or branched C.sub.1 to C.sub.8-alkyl group, or a C.sub.2-C.sub.8-alkylene group, or the two of R.sub.1 can form together an optionally substituted aliphatic 3 to 6 membered ring with the C or Si-atoms they are attached to and R.sub.2, R.sub.3, R.sub.3, R.sub.4, R.sub.4, R.sub.5 and R.sub.5 are the same or different and can be hydrogen, a linear or branched C.sub.1 to C.sub.8-alkyl, or a C.sub.3-C.sub.8-alkylene group, wherein two or more of R.sub.2, R.sub.3, R.sub.3, R.sub.4, R.sub.4, R.sub.5 and R.sub.5 can form a ring, or any two neighbored R.sub.2, R.sub.3, R.sub.4 and R.sub.5 can represent a double bond, and optionally at least one of the C-atoms in the oxygen-containing rings can be replaced by a heteroatom selected from O, N and P.

11. The procatalyst according to claim 10, wherein in formula (IV): Y is C(R.sub.1).sub.2 or Si(R.sub.1).sub.2, R.sub.1 are the same and are a linear or branched C.sub.1 to C.sub.5-alkyl group, R.sub.2, R.sub.3, R.sub.3, R.sub.4, R.sub.4, R.sub.5 and R.sub.5 are the same or different and can be hydrogen, linear or branched C.sub.1 to C.sub.5-alkyl group.

12. The procatalyst according to claim 9, wherein the compound (C) is 2,2-di(2-tetrahydrofuryl)propane (DTHFP).

13. The procatalyst according to claim 9, wherein the molar ratio of ED/Mg is 0.01 to below 0.40.

14. A catalyst system comprising a procatalyst according to claim 9, and an activating cocatalyst of formula (V):
R.sub.3-nAIX.sub.n(V) wherein R is a C.sub.1 to C.sub.20 alkyl, X is halogen, and n is 0, 1 or 2.

15. A process for producing an ethylene copolymer, comprising: (a) introducing a procatalyst according to claim 9 into a polymerisation reactor; (b) introducing a cocatalyst, which activates the procatalyst, into the polymerization reactor, wherein the cocatalyst is an organometallic compound of formula (V) as defined in claim 14; (c) introducing ethylene, C.sub.3-C.sub.12 -olefins and optionally hydrogen into the polymerisation reactor, and (d) copolymerizing said ethylene and C.sub.3-C.sub.12 -olefins in said polymerisation reactor to produce an ethylene copolymer.

Description

EXAMPLES

(1) The following non-limiting examples are provided in order to illustrate the invention and to compare it to the prior art.

(2) 1. Definitions/Measuring Methods

(3) The following definitions of terms and determination methods apply for the above general description of the invention as well as to the below examples unless otherwise defined. MFR.sub.2 (190 C.) is measured according to ISO 1133 (190 C., 2.16 kg load). MFR.sub.21 (190 C.) is measured according to ISO 1133 (190 C., 21.6 kg load). Density is measured according to ISO 1183-1method A (2004). Sample preparation is done by compression moulding in accordance with ISO 1872-2:2007. Porosity: BET with N.sub.2 gas, ASTM 4641, apparatus Micromeritics Tristar 3000; sample preparation: at a temperature of 50 C., 6 hours in vacuum. Surface area: BET with N.sub.2 gas ASTM D 3663, apparatus Micromeritics Tristar 3000: sample preparation: at a temperature of 50 C., 6 hours in vacuum. Bulk density is measured by using the method ASTM D 1895V.
Comonomer Content from PE (FTIR)

(4) Comonomer content was determined in a known manner based on Fourier transform infrared spectroscopy (FTIR) determination using Nicolet Magna 550 IR spectrometer together with Nicolet Omnic FTIR software.

(5) Films having a thickness of about 220 to 250 m were compression molded from the samples. Similar films were made from calibration samples having a known content of the comonomer. The thicknesses were measured from at least five points of the film. The films were then rubbed with sandpaper to eliminate reflections. The films were not touched by plain hand to avoid contamination. For each sample and calibration sample at least two films were prepared. The films were pressed from pellets by using a Graceby Specac film press at 150 C. using 3+2 minutes preheating time, 1 minute compression time and 4 to 5 minutes cooling time. For very high molecular weight samples the preheating time may be prolonged or the temperature increased.

(6) The comonomer content was determined from the absorbance at the wave number of approximately 1378 cm.sup.1. The comonomer used in the calibration samples was the same as the comonomer present in the samples. The analysis was performed by using the resolution of 2 cm.sup.1, wave number span of from 4000 to 400 cm.sup.1 and the number of sweeps of 128. At least two spectra were run from each film.

(7) The comonomer content was determined from the spectrum from the wave number range of from 1430 to 1100 cm.sup.1. The absorbance is measured as the height of the peak by selecting the so-called short or long base line or both. The short base line is drawn in about 1410-1320 cm.sup.1 through the minimum points and the long base line about between 1410 and 1220 cm.sup.1. Calibrations need to be done specifically for each base line type. Also, the comonomer content of the unknown sample needs to be within the range of the comonomer contents of the calibration samples.

(8) From the calibration samples a straight line is obtained as follows:

(9) $C_i=k.Math.\frac{A_{1378,i}}{s_i}+b$
where C.sub.1 is the comonomer content of the calibration sample i A.sub.1378,i is the absorbance at appr. 1378 cm.sup.1 of sample i s.sub.i is the thickness of the film made of calibration sample i k is the slope of the calibration line (obtained by regression analysis), and b is the intercept of the calibration line (obtained by regression analysis).

(10) By using the thus obtained parameters k and b the comonomer content of the samples were obtained from

(11) $C_x=k.Math.\frac{A_{1378,x}}{s_x}+b$
where C.sub.x is the comonomer content of the unknown sample A.sub.1378,x is the absorbance at appr. 1378 cm.sup.1 of the unknown sample s.sub.x is the thickness of the film made of the unknown sample k is the slope of the calibration line obtained from the calibration samples as above b is the intercept of the calibration line obtained from the calibration samples.

(12) The method gives the comonomer content in weight-% or in mol-%, depending on which was used in the calibration. If properly calibrated, the same approach may also be used to determine the number of methyl groups, i.e., CH.sub.3 per 1000 carbon atoms.

(13) 2. Examples

(14) Chemicals Used in the Examples

(15) SilicaGrace Davison ES 757, THF (tetrahydrofuran)CAS no 109-99-9, supplier Scharlau 2,2-di(2-tetrahydrofuryl)propane (DTHFP), TCI Europe EADC (ethyl-aluminium-di-chloride)supplier Sigma-Aldrich BOMAG (octyl-butyl-Mg) (Mg(Bu)1,5(Oct).sub.0.5)supplier Chemtura
A. Catalyst Examples

(16) In the examples below the molar ratios (Donor/Mg) are ratios of components added during the catalyst preparation procedure.

Comparison Example 1 (CE1)

No Donor

(17) Silica calcinated at 600 C. for 6 h is used as carrier material. 5 g of silica is used for the synthesis. 1.1 mmol of 25% heptane solution of ethyl-aluminium-di-chloride (EADC) is added per gram of silica. The EADC is allowed to react with the silica at a temperature between 30 C. and 40 C. for 1 h. Subsequently, 1.0 mmol of a Mg-alcoholate solution is added per gram of silica. The Mg-solution is prepared by adding 2-ethyl-hexanol to an octyl-butyl-Mg (BOMAG) solution in a molar ratio of 1.83 to 1. The Mg-reagent is allowed to react with the EADC for 1h at a temperature between 30 C. and 40 C. Heptane is added to create a slurry. The reaction temperature during the preparation is kept between 30 C. and 40 C. Subsequently, 0.5 mmol of TiCl.sub.4 is slowly added per gram of silica during an addition time of h. The components are allowed to react with each other for 1 h. The reaction temperature is kept between 40 C. and 50 C. Finally, the catalyst is dried under a stream of nitrogen at a temperature between 60 C. and 90 C.

Comparative Example 2 (CE2)

THF as Donor

(18) The same catalyst is prepared according to the description of Comparative Example 1 except that 0.52 mmol of THF is added per gram of silica at a temperature between 30 C. and 40 C. over a period of 20 min after titanation (THF/Mg molar ratio 0.52)

Comparative Example 3 (CE3)

DTHFP as DonorAddition of DTHFP with Mg-Solution

(19) The same recipe was used as in the Comparative example 1 with the exception that DTHFP was mixed with the Mg-alcoholate solution and thus DTHFP was added together with the Mg-alcoholate solution to the EADC treated silica. The DTHFP/Mg molar ratio was 0.25. Addition was done between 30 C. and 40 C. over a period of 20 min.

Comparative Example 4 (CE4)

DTHFP as DonorAddition of DTHFP with Mg-Solution

(20) The same recipe was used as in the Comparison example 3, but the DTHFP/Mg molar ratio was 0.1.

Comparative Example 5 (CE5)

DTHFP as DonorAddition of DTHFP after Addition of TiCl4

(21) The same procedure was followed as in Comparative example 2, with the exception that the instead of THF, DTHFP was added after the TiCl.sub.4 addition (DTHFP/Mg molar ration 0.25) at a temperature between 30-40 C., addition time was 20 min.

Comparative Example 6 (CE6)

THF as DonorAddition of THF after Addition of EADC

(22) The same procedure was followed as in Inventive Example 1 with the exception that the THF was used instead of DTHFP (THF/Mg molar ratio 0.25). Addition time was 20 min and addition temperature 30 C.

Inventive Example 1 (IE1)

DTHFP as DonorAddition of DTHFP after Addition of EADC

(23) The same procedure was followed as in Comparative Example 6 with the exception that instead of THF as donor DTHFP was used, which was added on the silica support after the addition of EADC but before the addition of the Mg-solution. DTHF/Mg molar ratio was 0.25, Addition time was 20 min and addition temperature 30 C.

Comparative Example 7 (CE7)

DTHFP as DonorAddition of DTHFP after Addition of EADC, Higher Donor/Mg Ratio

(24) The same procedure was followed as in Inventive Example 1, but the molar ratio of DTHFP/Mg was 0.50.

(25) B. Polymerisation Examples (ethylene-1-butene co-polymerization)

(26) All the catalysts were tested in 1-butene copolymerization. 40 to 50 mg of catalyst was used in all the polymerizations and tri-ethylaluminium (TEA) was used as co-catalyst with an Al/Ti ratio of 30. The polymerizations were carried out in a 3 L bench scale reactor, whose procedure is as follows: To an empty 3 L reactor was added 55 ml of 1-butene using 0.2 bar of nitrogen pressure and stirring at 200 rpm was started. 1250 ml of propane was fed to the polymerization reactor as a polymerization medium. After addition of the reaction medium, hydrogen was introduced (0.75 bar) after which temperature was increased to 85 C. A batch of ethylene (3.7 bar) was added, then reactor pressure was allowed to be stable at 0.2 bar of overpressure and stirring speed was increased to 450 rpm. Then the catalyst and the co-catalyst were added through automatic feeding using N.sub.2 and 100 ml of propane. The total reactor pressure was 38 bar, which was maintained by continuos ethylene feed.

(27) Polymerization time was 60 min after which the polymerization was stopped by venting off the monomer together with the reaction medium. Activity of the catalyst was measured on the basis of the amount of polymer produced. Some information about the molecular weight and molecular weight broadness was received through MFR values. The butene-co-monomer amount was measured by IR. The results are listed in Table 1.

(28) TABLE-US-00001 TABLE 1 The polymerization results Example CE1 CE2 CE3 CE4 CE5 CE6 IE1 CE6 Donor no I II II II I II II Donor amount (mol/mol).sup.1) 0 0.52 0.25 0.1 0.25 0.25 0.25 0.50 Activity [kg PO/g].sup.2) 4.4 2.7 0.1 0.8 0.4 0.53 4.0 0.02 C4.sup.3) [wt.-%] 4.2 4.6 2.9 6.2 3.5 BD.sup.4) [kg/m.sup.3] 410 390 410 425 MFR.sub.2 [g/10 min] 2.7 2.1 n.d..sup.6) 7.8 1.5 MFR.sub.21 [g/10 min] 71.6 52.5 13.3 37.7 FRR.sup.5) [] 26.5 25 n.d. 25.1 .sup.1)Donor/Mg .sup.2)PO means produced ethylene-1-butene copolymer, .sup.3)C4 means 1-butene .sup.4)BD means Bulk density, .sup.5)FRR means MFR.sub.21/MFR.sub.2 .sup.6)not determined I THF II DTHFP

(29) Polymer of comparative examples CE3, CE5 and CE6 was not analyzed due to the very poor activity.

(30) The results show that the DTHFP donor has to be added on the silica after the EADC addition to achieve a reasonable activity in co-polymerization. Further, the results show that too high donor amounts result in loss of activity.

(31) A narrower molecular weight distribution is achieved (FRR=25.1) for IE1 compared to CE1.

(32) It can be seen that molecular weight of IE1 is higher than of CE1 and CE2 (lower MFR's). In CE4 molecular weight is still higher than in IE1, but the activity is very low and C4 incorporation smaller.

(33) Bulk density is also higher in the present invention.