WO2003006961A1

WO2003006961A1 - Determination of the polymerisation activity of metallocene catalysts using uv/vis spectroscopy

Info

Publication number: WO2003006961A1
Application number: PCT/EP2002/007342
Authority: WO
Inventors: Nicola Paczkowski; Heike Gregorius; Marc Oliver Kristen; Carsten SÜLING; Jürgen Suhm; Hans-Herbert Brintzinger; Ulrich Wieser
Original assignee: Basf Aktiengesellschaft
Priority date: 2001-07-09
Filing date: 2002-07-03
Publication date: 2003-01-23
Also published as: DE10132519A1

Abstract

The invention relates to a method for determining the activity of metallocene catalysts in the polymerisation of alk-1-enes or vinylaromatic compounds using UV/VIS spectroscopy, comprising the following steps: a) determination of the characteristic UV/VIS extinction values of specific metallocene catalyst samples, b) determination of the polymerisation activity of said metallocene catalyst samples, c) creation of a calibration curve from the respective pairs of values in steps a) and b), d) determination of the polymerisation activity of any metallocene catalyst, by measuring its UV/VIS extinction value and reading the corresponding polymerisation activity from the calibration curve in step c). The method is characterised in that the metallocene catalysts in steps a) to d) are carrier-bound. The invention also relates to a device for measuring the UV/VIS spectra of carrier-bound metallocene catalysts and to the use of UV/VIS spectroscopy for determining the activity of carrier-bound metallocene catalysts.

Description

DETERMINATION OF THE POLYMERIZATION ACTIVITY OF METALLOCENE CATALYSTS BY UV / VIS SPECTROSCOPY

5 Description

The present invention relates to a method for determining the activity of metallocene catalysts in the polymerization of alk-1-enes or vinylaromatic compounds.

10 device for measuring the UV / VIS spectra of support-fixed metallocene catalysts, the use of UV / VIS spectroscopy to determine the activity of support-fixed metallocene catalysts in the polymerization of alk-1-enes or vinylaromatic compounds and the use of a device

15 according to claim 6 for the determination of the activity of carrier-fixed metallocene catalysts in the polymerization of alk-1-enes or vinylaromatic compounds.

Metallocene catalysts for the polymerization of alk-1-enes or 20 vinylaromatic compounds are known, but are of great industrial interest. The catalysts are formed when metallocene complexes are allowed to react with, for example, aluminoxanes.

25 UV / VIS spectroscopy was also used to clarify the formation of certain polymerization-active metallocene catalysts (Makromol. Chem. Phys. 199, pages 1451 to 1457 and 1459 to 1464 (1998). These investigations on dissolved, unsupported, metallocene catalysts were recognized that

30 the polymerization activity of the metallocene catalysts correlated with the position (wavelength) of the metallocene absorption band.

The dissertation by S. J. Obert "Covalent support fixation of ansa-metallocenes" (University of Konstanz 1999) mentions on page 35 that UV / VIS spectra can also be used for support-fixed metallocene catalysts in order to find out whether they are active in principle.

No UV / VIS method is disclosed in the prior art with which the polymerization activity of metallocene catalysts can be determined quantitatively.

The object of the present invention was therefore to develop a fast, easy-to-carry out spectroscopic method 45 with which the polymerization activity of many metallocene catalyst samples can be determined quantitatively, without having to individually examine each catalyst sample for its activity in complex polymerization tests.

Accordingly, a method for determining the activity of metallocene catalysts in the polymerization of alk-1-enes or vinylaromatic compounds by UV / VIS spectroscopy was carried out

a) Determination of the characteristic UV / VIS extinction values of certain metallocene catalyst samples, b) Determination of the polymerization activities of these metallocene catalyst samples, c) Creation of a calibration curve from the respective value pairs from a) and b), d) Determination of the polymerization activity of a any metallocene catalyst, by measuring its UV / VIS absorbance and reading the associated polymerization activity from the calibration curve c),

characterized in that a) to d) are supported metallocene catalysts, a device for measuring the UV / VIS spectra of supported metallocene catalysts

A) a storage vessel for the supported metallocene catalyst,

B) a UV / VIS immersion probe, which is immersed in the receptacle A),

C) a magnetically driven spiral stirrer which is vertically mounted on a cone tip in the receptacle, A),

the use of UV / VIS spectroscopy to determine the activity of supported metallocene catalysts in the polymerization of alk-1-enes or vinylaromatic compounds and the use of an apparatus according to claim 6 for determining the activity of supported metallocene catalysts in the polymerization of alk-1 or vinyl aromatic compounds

found.

The alk-1-ene polymers according to the invention are homo- or copolymers of a) C ₂ - to Cιo ~ alk-l-enes, preferably propylene, 1-butene, 1-hexene, 1-octene, or of b) vinyl aromatic compounds C, preferably ₈ -C ₂ o ^_ vinylaromatics, for example styrene, p-methylstyrene, p-methoxystyrene. Metallocene catalysts are understood to mean all catalyst systems which contain at least one metallocene compound. Metallocenes are all complex compounds of metals from subgroups of the periodic table with organic ligands, which together with compounds forming metallocenium ions result in effective catalyst systems.

Metallocene catalysts suitable according to the invention generally contain as active constituents

A) at least one metallocene complex of the general formula (I)

in which the substituents and indices have the following meaning:

M titanium, zirconium, hafnium, vanadium, niobium or

Tantalum, as well as elements of the III. Subgroup of the periodic table and the lanthanoids,

X fluorine, chlorine, bromine, iodine, hydrogen, -CC-alkyl, C ₆ -C ₁₅ aryl, alkylaryl with 1 to

10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, -OR ⁶ or -NR ⁶ R ⁷ ,

n 1, 2 or 3, where n corresponds to the valency of M minus the number 2, where

R ⁶ and R ⁷ -CC-alkyl, C ₆ -C ₁₅ aryl, alkylaryl, arylalkyl,

Fluoroalkyl or fluoroaryl each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical and

the radicals X are the same or different,

R ¹ to R ^{5 are} hydrogen, -CC ₁₀ alkyl, 5- to 7-membered

Cycloalkyl, which in turn can be substituted by Cι-~ alkyl, Cg-Cis-aryl or aryl alkyl, where two adjacent radicals together can represent saturated or unsaturated cyclic groups having 4 to 15 carbon atoms, or Si (R ⁸ ) ₃ with

R ⁸ can be C ₁ -C ⁸ alkyl, C ₃ -C ₁₀ cycloalkyl or C ₆ -C ₅ aryl and

being the leftovers

R ⁹ to R ^{13 are} hydrogen, Ci-Cio-Alk l, 5- to 7-membered

Cycloalkyl, which in turn can be substituted by -CC-alkyl, mean C _δ -cis-aryl or arylalkyl and where two adjacent radicals together can also represent saturated or unsaturated cyclic groups having 4 to 15 C atoms, or Si (R ^α ) ₃ with

R ¹⁴ Cι-Cιo-alkyl, C ₃ -Cι ₀ cycloalkyl or C _δ -C ₁₅ aryl,

or wherein the radicals R ⁴ and Z together form a group -R ¹⁵ -A- in which

= BR ^iδ , = AIR ", -Ge-, -Sn-, -O-, -S-, = SO, = S0 ₂ ,

R16 R16 R16 R16

15 ml, ml ml, ml CR218 _^ IIII ^'

R17 R17 R17 R17

R16 R16 R16 R16 I I I I

C> 0 ml, C C '

R17 R17 R17 R17 = NR ⁱ δ, = co, = PR ^α6 or = P (0) R ¹⁶ , where R ¹⁶ , R ¹⁷ and R ^{18 are the} same or different and are each one

Hydrogen atom, a halogen atom, a Cχ-Cιo-alkyl group, a Cχ-Cιo-fluoroalkyl group, a C ₆ -Cιo-pluoraryl group, a C ₆ -Cι ₀ aryl group, a Cι-Cιo alkoxy group, a

C ₂ ^_ Cιo-alkenyl group, a C7-C ₄₀ arylalkyl group, a C ₈ ~ C ₄ o-arylalkenyl group or a C ₇ -C ₄ o-alkylaryl group or where two adjacent radicals each have a 4th with the atoms connecting them form up to 15 carbon atoms having saturated or unsaturated ring, and

M ^{1 is} silicon, germanium or tin,

\ \ ^^ N 19 ^ PR19

A 0 S or mean with

R ^{19 is} Cχ-Cαo-alkyl, C ₆ -Ci ₅ aryl, C ₃ -Cιo-cycloalkyl,

C ₇ -C ₈ alkylaryl or Si (R ²⁰ ) ₃ ,

R ^{20 is} hydrogen, Ci-Cio-alkyl, C _ß- Cis-aryl, which in turn can be substituted with -C-C ₄ ~ alkyl groups or C ₃ -Cιo-cyclo ^~ a1kyl

or wherein the radicals R ⁴ and R ¹² together form a group -R ¹⁵ -.

The radicals X in the general formula (I) are preferably the same.

Of the metal of general formula (I) are

prefers.

Of the compounds of the formula (Ia), those are particularly preferred in which

M titanium, zirconium or hafnium,

X is chlorine, C 1 -C 4 -alkyl or phenyl, n is the number 2 and

R ¹ to R ^{5 are} hydrogen or Cχ-C ₄ alkyl.

Preferred compounds of the formula (Ib) are those in which

M stands for titanium, zirconium or hafnium,

X chlorine, -CC alkyl or phenyl,

n is the number 2,

R ¹ to R ^{5 are} hydrogen, Cχ-C ₄ ~ alkyl or Si (R ⁸ ) ₃ and

R ⁹ to R ^{13 are} hydrogen, C ¹ -C ₄ -alkyl or Si (R ¹ ) ₃ .

The compounds of the formula (Ib) in which the cyclopentadienyl radicals are identical are particularly suitable.

Examples of particularly suitable compounds include : Bis (cyclopentadienyl) zirconium dichloride, bis (pentamethylcyclopentadienyl) zirconium dichloride, bis (methylcyclopentadienyl) zirconium dichloride, • bis (ethylcyclopentadienyl) zirconium dichloride,

Bis (n-butylcyclopentadienyl) zirconium dichloride and bis (tri ethylsilylcyclopentadienyl) zirconium dichloride as well as the corresponding dimethyl zirconium compounds.

Of the compounds of the formula (Ic), those in which

R ¹ and R ⁹ are the same groups and hydrogen or Ci-CIQ alkyl ^■ stand,

R ⁵ and R ^{13 are the} same and for hydrogen, a methyl,

Ethyl, iso-propyl or tert. -Butyl group,

R ³ and R ¹¹ -C-alkyl and

R ² and R ^{10 are} hydrogen

or two adjacent radicals R ² and R ³ and R ¹⁰ and R ¹¹ together represent saturated or unsaturated cyclic groups having 4 to 12 carbon atoms,

^R1 6 R16 R16

R15 for Ml or _cc ste _h t,

17 Ri7 R17

M for titanium, zirconium or hafnium and

X represents chlorine, Cχ-C ₄ alkyl or phenyl.

Examples of particularly suitable complex compounds (Ic) include Dimethylsilanediylbis (cyclopentadienyl) zirconium dichloride,

Dimethylsilanediylbis (indenyl) zirconium dichloride,

Dimethylsilanediylbis (tetrahydroindenyl) zirconium dichloride,

Ethylene bis (cyclopentadienyl) zirconium dichloride, ethylene bis (indenyl) zirconium dichloride, ethylene bis (tetrahydroindenyl) zirconium dichloride,

Tetramethylethylene-9-fluorenylcyclopentadienylzirkoniu diChlorid,

Dimethylsilanediylbis (3-tert-butyl-5-methylcyclopentadienyl) zirconium dichloride,

Dimethylsilanediylbis (3-tert.butyl-5-ethylcyclopen adienyl) zirconium dichloride,

Dimethylsilanediylbis (2-methylindenyl) zirconium dichloride,

Dimethylsilanediylbis (2-isopropylindenyl) zirconium dichloride,

Dimethylsilanediylbis (2-tert. Butylindenyl) zirconium dichloride,

Diethylsilanediylbis (2-methylindenyl) zirconium dibromide, dimethylsilanediylbis (3-methyl-5-methylcyclopentadienyl) zirconium dichloride,

Dimethylsilanediylbis (3-ethyl-5-isopropylcyclopentadienyl) zirconium dichloride,

Dimethylsilanediylbis (2-ethylindenyl) zirconium dichloride, dimethylsilanediylbis (2-methyl-4,5-benzindenyl) zirconium dichloride

Dimethylsilanediylbis (2-ethyl-4,5-benzindenyl) zirconium dichloride

Methylphenylsilanediylbis (2-methyl-4,5-benzindenyl) zirconium dichloride,

Methylphenylsilanediylbis (2-ethyl-4,5-benzindenyl) zirconium dichloride,

Diphenylsilanediylbis (2-methyl-4,5-benzindenyl) zirconium dichloride,

Diphenylsilanediylbis (2-ethyl-4,5-benzindenyl) zirconium dichloride and diphenylsilanediylbis (2-methylindenyl) hafnium dichloride and the corresponding dimethylzirconium compounds.

Other examples of suitable complex compounds include Dimethylsilanediylbis (2-methyl-4-phenylindenyl) zirconium dichloride, dimethylsilanediylbis (2-methyl-4-naphthylindenyl) zirconium dichloride,

Dimethylsilanediylbis (2-methyl-4-isopropylindenyl) zirconium dichloride, dimethylsilanediylbis (2-methyl-4, 6-diisopropylindenyl) zirconium dichloride,

Dimethylsilanediylbis (2-methyl-4 [4'-tert.butylphenyl] indenyl) zirconium dichloride, dimethylsilanediylbis (2-ethyl-4 [4'-tert.butylphenyl] indenyl) zirconium dichloride,

Dimethylsilanediylbis (2-propyl-4 [4'-tert.butylphenyl] indenyl) zirconium dichloride and

Dimethylsilanediyl (2-isopropyl-4 [4 't-butylphenyl] indenyl) - (2-methyl-4 [4' t-butylphenyl] indenyl) zirconium dichloride and the corresponding dimethyl zirconium compounds.

In the case of the compounds of the general formula (id), those in which

M for titanium or zirconium,

X represents chlorine, Cχ-C ₄ alkyl or phenyl.

R16 R16 R16

R15 stands for Ml or _cc ,

¹⁷ R17 R17

and

for NR19

R ¹ to R ³ and R ^{5 are} hydrogen, Cχ-Cιo-alkyl, C ₃ -Cι ₀ -cycloalkyl,

C ₆ -Ci ₅ aryl or Si (R ⁸ ) ₃ , or where two adjacent radicals stand for 4 to 12 C atoms-containing cyclic groups. Such complex compounds can be synthesized by methods known per se, the reaction of the appropriately substituted cyclic hydrocarbon anions with halides of titanium, zirconium, hafnium, vanadium, niobium or tantalum being preferred.

Examples of corresponding manufacturing processes include in the Journal of Organometallic Chemistry, 369 (1989), 359-370.

Mixtures of different metal ocene complexes can also be used as component A).

Furthermore, the metallocene catalysts contain as component B) at least one compound which forms metallocenium ions.

Suitable metallocenium ion-forming compounds B) are, for example, strong, neutral Lewis acids, ionic compounds with Lewis acid cations or ionic compounds with Bronsted acids as cations.

Compounds of the general formula (II) are strong, neutral Lewis acids

M ² X ¹ X ² X ³ (II

preferred in the

M ^{2 is} an element of III. Main group of the periodic system means, in particular B, Al or Ga, preferably B,

X ¹ , X ² and X ³ for hydrogen, Cχ-Cιo-alkyl, C _ß- Cis-aryl, alkylaryl, arylalkyl, haloalkyl or haloaryl, each with 1 to 10 carbon atoms in the alkyl radical and

6 to 20 carbon atoms in the aryl radical or fluorine, chlorine, bromine or iodine are, in particular halogen aryls, preferably pentafluorophenyl.

Compounds of the general formula are particularly preferred

(II) in which X ¹ , X ² and X ^{3 are the} same, preferably tris (pentafluorophenyl) borane.

As ionic compounds with Lewis acid cations, compounds of the general formula (III) [Ya +) QιQ ₂ . , , Q ₂ ] d + (III)

suitable in which

Y is an element of I. to VI. Main group or the

I. to VIII. Subgroup of the periodic table means,

Qi to 0. ₂ for simply negatively charged residues such as

C ₁ -C ₂₈ alkyl, C ₆ -C ₁₅ aryl, alkylaryl, arylalkyl, haloalkyl, haloaryl each having 6 to 20 C atoms in the aryl and 1 to 28 C atoms in the alkyl radical, C ₃ -Cιo-cycloalkyl , which can optionally be substituted with Cι-~ alkyl groups, halogen, -C-C ₂₈ alkoxy, Cε-Cis-aryloxy, silyl or mercaptyl groups

a for integers from 1 to 6 and

z represents integers from 0 to 5,

d corresponds to the difference a-z, but d is greater than or equal to 1.

Carbonium cations, oxonium cations and sulfonium cations as well as cationic transition metal complexes are particularly suitable. The triphenylmethyl cation, the silver cation and the 1, 1 '-dimethylferrocenyl cation should be mentioned in particular. They preferably have non-coordinating counterions, in particular boron compounds, as they are also mentioned in WO 91/09882, preferably tetrakis (pentafluorophenyl) borate.

Ionic compounds with Bronsted acids as cations and preferably also non-coordinating counterions are mentioned in WO 91/09882; the preferred cation is N, N-dimethylanilinium.

The amount of strong, neutral Lewis acids, ionic compounds with Lewis acid cations or ionic compounds with Bronsted acids as cations is preferably 0.1 to 10 equivalents, based on the metallocene complex A). Open-chain or cyclic alumoxane compounds of the general formulas (IV) or (V) are particularly suitable as compound B) forming metallocenium ions.

R21 \

, A1 ^~ T ^" 0 AI-! M ^' R21 (IV)

R21

R21

where R ^{21 is} a C 1 -C ₄ alkyl group, preferably a methyl or ethyl group and m is an integer from 5 to 30, preferably 10 to 25.

These oligomeric alumoxane compounds are usually prepared by reacting a solution of trialkylaluminum with water and include in EP-A 284 708 and US-A 4 794 096.

As a rule, the oligomeric alumoxane compounds obtained in this way are present as mixtures of both linear and cyclic chain molecules of different lengths, so that m is to be regarded as the mean. The alumoxane compounds can also be present in a mixture with other metal alkyls, preferably with aluminum alkyls.

It has proven advantageous to use the metallocene complexes A) and the oligomeric alumoxane compounds of the general formula (IV) or (V) in amounts such that the atomic ratio between aluminum from the oligomeric alumoxane compounds and the transition metal from the metallocene complexes in Range from 10: 1 to 10 ⁶ : 1, in particular in the range from 10: 1 to 10: 1.

Furthermore, as component B), instead of the alumoxane compounds of the general formulas (IV) or (V) aryloxyalumoxanes, as described in US Pat. No. 5,391,793, aminoaluminoxanes, as described in US Pat. No. 5,371,260, aminoaluminoxane hydrochlorides , as described in EP-A 633 264, siloxyaluminoxanes, such as described in EP-A 621 279, or mixtures thereof are used.

Suitable compounds B) forming metallocenium ions are also the boron-aluminum compounds disclosed in WO 99/06414, such as, for example, di- [bis (pentafluorophenylboroxy)] methylalane. The boron-aluminum compounds can also be used deposited on an organic or inorganic carrier.

Both the metallocene complexes A) and the metallocenium ion-forming compounds B) are preferably used in solution, aromatic hydrocarbons having 6 to 20 C atoms, in particular xylenes and toluene, being particularly preferred.

Suitable metallocene catalysts can additionally contain a metal compound of the general formula (VI) as further component C)

_M 3 ( _R 22) _r ( _R 23) _s ( _R 24) _t (VI)

in the

M ^{3 is} an alkali, an alkaline earth metal or a metal de-rl-Il-. Main group of the periodic table, ie boron, aluminum, gallium, indium or thallium,

R ^{22 is} hydrogen, -CC- ₀ alkyl, Cg-cis-aryl, alkylaryl or arylalkyl, each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical,

R ²³ and R ²⁴ is hydrogen, halogen, Cι-Cι ₀ alkyl, C ₅ _e -Cι aryl,

Alkylaryl, arylalkyl or alkoxy each having 1 to 10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical,

r is an integer from 1 to 3

and

s and t are integers from 0 to 2, the

Sum r + s + t corresponds to the valence of M ³ ,

contain. Of the metal compounds of the general formula (VI), those are preferred in which

M ^{3 means} lithium, magnesium or aluminum and

R ²³ and R ²⁴ for Cι-Cι are ₀ alkyl.

Particularly preferred metal compounds of the formula (VI) are n-butyl-lithium, n-butyl-n-octyl-magnesium, n-butyl-n-heptyl-magnesium, tri-n-hexyl aluminum, tri-iso-butyl -aluminium, triethylaluminium and trimethylaluminium.

If a metal compound C) is used, it is preferably present in the catalyst system in an amount such that the molar ratio of M ³ from formula (VI) to transition metal M from formula (I) is from 800: 1 to 1: 1, in particular 500 : 1 to 50: 1.

In addition to metallocene complexes A), other polymerization catalysts such as e.g. the nickel and palladium complexes described in WO 96/23010, the iron and cobalt complexes described in WO 98/27124, WO 98/30612, WO 99/12981 and WO 00/50470, the complexes described in WO 00 / 58370 and WO 01/12641 described chromium complexes but also other transition metal complexes such as that in Angewandte Chemie 1999, 111, p.448, Chem Rev. 2000, 100, 1169, Coord. Chem. Rew. 2000, 203, 325 can be used.

The metallocene complexes are generally used on a carrier material.

The carrier materials used are preferably fine-particle, porous carriers which generally have a particle diameter in the range from 1 to 300 μm, in particular from 20 to 90 μm. Suitable carrier materials are, for example, inorganic oxides of silicon, aluminum, titanium or one of the metals of main group I or II of the periodic table or mixtures of these oxides, of which, in addition to aluminum oxide or magnesium oxide or a layered silicate, silica gel is particularly preferred.

UV / viS tests on air and / or moisture-insensitive metallocene catalysts can be carried out in any commercially available UV / VIS apparatus.

UV / VIS spectroscopic measurements on air and / or moisture sensitive metallocene catalysts are preferably carried out in a special apparatus. This is composed from a commercially available UV / VIS immersion probe with light guide technology, a Schlenk vessel and a stirrer. This apparatus enables working under vacuum and / or protective gas.

The UV / VIS spectra are particularly preferably recorded with stirring on a Carry 50 UV / VIS spectrometer from Varian, for example the spectrum of a silica gel pretreated with aluminum alkyl is selected as the backround. Strong noise can be reduced by spectrum accumulation and a mathematical smoothing function.

The development of a special stirrer with a minimal contact area of the stirring unit on the bottom of the vessel has proven to be very advantageous, since a conventional magnetic stirring bar leads to a mechanical comminution of the supported catalyst after only a few minutes of stirring and to an associated strong increase in the intensity of the charge transfer band can lead. This generally leads to a falsification of the measurement results. The stirrer according to the invention is outlined in FIG. 1.

For the UV / VIS spectroscopic determination of the polymerization activity of supported metallocene catalysts, various catalyst samples are examined both with UV / VIS spectroscopy and with regard to their polymerisation activity. - By applying the characteristic UV / VIS extinction value of the charge transfer band (e.g. at 485 n for the metallocene catalyst Me ₂ Si (2-Me-4, 5-benzoindenyl) ₂ ZrCl ₂ / methylaluminoxane / Siθ ₂ ) which reflects the content of the catalytically active species, against the productivity of the individual catalyst batches determined in the polymerization test (conditions, for example: propylene monomer, polymerization temperature = 65 ° C., polymerization pressure = 28 bar), the calibration curve is established.

The above-mentioned "characteristic UV / viS extinction values" are the intensities of the absorption bands, as described, at the respective maxima of the UV / VIS spectra

Examples

1. UV / VIS spectroscopic measurements

Sample preparation:

The Schlenk vessel and the stirrer were heated in the drying cabinet at 100 ° C for one hour and then introduced into a glove box. There, 210 mg of the supported metallocene catalyst (Me ₂ Si (2-Me-benzoindenyl) ₂ ZrCl ₂ / methylaluminoxane / SiO 2) were weighed into the Schlenk vessel and the stirrer according to FIG. 1 was used. The immersion probe, from which the last traces of moisture were blown with the help of a hot air, was introduced in the counter-argon flow. The apparatus was evacuated for 5 minutes. 30 ml of toluene were then added.

Spectra recording:

The light guides of the exchange probe were connected to the UV / VIS spectrometer (Cary 50 UV / VIS spectrometer from Varian). The stored background spectrum (MAO-pretreated silica gel with 17% by weight AI) was loaded. The magnetic stirrer was set to about 3/4 of the stirring strength. There was a wait of 30 seconds until the catalyst suspension had mixed thoroughly. The absorption at 800 nm was checked and, if it was not at zero, set to zero using a screw on the optical fiber coupling / decoupling unit. Ten spectra were recorded in succession in the cycle mode with the fastest recording speed (0 seconds waiting time).

Evaluation of the spectra:

The ten spectra were read in ASCII format in a specially written program and the average spectrum was formed from them. This was smoothed in ASCII format into the Origin program package-t-e-in-read-and -das -das- the noise floor with a smoothing function (moving average, filter 9). The absorbance value was then determined at 485 nm.

2. Determination of the polymerization activity in a 10-1 autoclave

100 g of polymer powder, 18 mmol of triisobutylaluminum (9 ml of a 2M solution in heptane) and 2 mmol of diisobutylaluminum hydride (1 ml of a 2M solution in.) Were placed in a dry nitrogen-purged IOL autoclave with stirring (100 rpm) Heptane). The autoclave was flushed three times with 5 bar nitrogen each and then filled with 150 mg - 500 mg catalyst and 7 L propylene in counter nitrogen flow. The contents of the autoclave were stirred at room temperature for 10 minutes. The autoclave was then gradually heated to a jacket temperature of 70-75 ° C. After reaching an internal temperature of 55 ° C, the stirrer speed was increased to 250 rpm and, after reaching the target temperature of 65 ° C, the catalyst for 90 minutes at the best possible

Temperature constant polymerized. The polymerization was terminated by venting the monomer and the product discharged through the bottom drain valve in a stream of nitrogen. 3. Catalyst preparation

a.) MAO-pretreated silica gel

55 g of spray-dried silica gel (average particle diameter: 70 ocm; pore volume 1.5 ml / g; heated for 8 hours at 180 ° C. in a vacuum (1 mbar)) were suspended in 220 ml of toluene and at room temperature within 60 minutes with 142 ml of one 4.75 molar methylaluminoxane solution (in toluene, from Albemarle) was added. The suspension was stirred overnight and then filtered. The filter cake was washed twice with 50 ml of toluene each time, and the carrier precursor was dried in a stream of nitrogen until it was free-flowing. Al content of the precursor dried to constant weight: 17.2% by weight.

b.) Supported metallocene catalyst

18 kg of spray-dried silica gel (average particle diameter: 70 ocm; pore volume 1.5 ml / g; baked for 8 hours at 180 ° C. in a vacuum (lmbar)) were at room temperature in a process filter (usable volume: 280 l) in 90 l Suspended toluene and mixed with 18.9 1 = 17.5 kg of a 30% by weight solution of methylalu inoxane in toluene (Albemarle company) (maximum _t = 35 ° C.). The reaction mixture was stirred for one hour at room temperature and then filtered. The filter cake was squeezed well with nitrogen. In parallel, 519.1 g = 0.9 mol of rac-dimethylsilanediylbis (2-methyl-4,5-benzoindenyl) zirconium dichloride with 3 _. 4.9 1 = 32.2 kg of a 30% by weight solution of methylaluminoxane in toluene (from Albemarle) and mixed with 74 l of toluene and stirred for one hour at room temperature. The MAO / metallocene solution would be slowly run to the carrier precursor with the drain tap closed. It was rinsed with 10 l of toluene. The process filter was then opened periodically so that the filtrate could run out within one hour. When no more filtrates came, the drain was closed, the filter cake was stirred for 15 minutes and left to stand for one hour at room temperature. The residual solution was then pressed off with nitrogen, the catalyst was washed once with 65 1 isododecane and once with 65 1 heptane and dried in vacuo. Results

Table 1: Absorbance values depending on the weight of the catalyst

Weighing out catalyst E (485 nm)

60 mg 0.045 126 mg 0.092 195 mg 0.171 300 mg 0.242

Table 2: Examined catalyst batches: The catalyst tests No. 1 to No. 5 were used to create a calibration line. Experiments No. 6 to No. 10 are the experiments according to the invention

Catalyst productivity [g g] E (485 nm) E (433 nm)

No.1 4325 0.220 0.213 No.2 6570-0: 361 "0.427 No.3 8320 0.447 0.426 No.4 4545 0.211 0.214 No.5 1720 0.124 0.118 No.6 1900 0.160 0.227 No.7 5120 0.237 0.239 No.8 4135 0.209 0.201 No. 9 2350 0.199 0.202 No. 10 2980 0.163 0.188

Table 3: Zr, Al and Si contents of the catalyst batches examined

Catalyst Zr content ^• Al content Si content

No. 1 0.32% by weight 17.4% by weight 28.2% by weight

No. 2 0.31% by weight 16.7% by weight 28.4% by weight

No. 3 0.64% by weight 18.5% by weight 25.1% by weight

No. 4 0.27% by weight 18.8% by weight 26.0% by weight No. 5 0.17% by weight ._ _. 17.4% by weight 27.5% by weight

No. 6 0.24% by weight 18.5% by weight 26.7% by weight

No. 7 0.25% by weight 18.5% by weight 26.6% by weight

No. 8 0.24% by weight 17.9% by weight 26.2% by weight

No. 9 0.26% by weight 18.5% by weight 26.2% by weight

No. 10 0.08% by weight 16.4% by weight -

Claims

claims

1. Method for determining the activity of metallocene catalysts in the polymerization of alk-1-enes or vinylaromatic compounds using UV / VIS spectroscopy

a) Determination of the characteristic UV / VIS extinction values of certain metallocene catalyst samples, b) Determination of the polymerization activities of these metallocene catalyst samples, c) Creation of a calibration curve from the respective value pairs from a) and b), d) Determination of the polymerization activity of a any metallocene catalyst, by measuring its TJV / VIS absorbance and reading the associated polymerization activity from the calibration curve c),

characterized in that a) to d) are supported metallocene catalysts.

2. The method according to claim 1, characterized in that the metallocene catalyst samples are agitated without friction when recording the UV / VIS spectra with a, on a magnetically driven, rotating about a vertical axis spiral stirrer.

3. Process according to claims 1 to 2, characterized in that a zirconium metallocene is used.

4. Process according to claims 1 to 3, characterized in that the carrier component is a porous, inorganic oxide.

5. Process according to claims 1 to 4, characterized in that the porous, inorganic oxide is silicon dioxide.

6. Device for measuring the UV / VIS spectra of supported metallocene catalysts

A) a receptacle for the supported metallocene catalyst,

B) a UV / VIS immersion probe, which is immersed in the receptacle A), C) a magnetically driven spiral stirrer located vertically on a cone tip in the receptacle A).

7. The device according to claim 6, which can be evacuated and / or filled with inert gases.

8. Use of UV / VIS spectroscopy to determine the activity of supported metallocene catalysts in the polymerization of alk-1-enes or vinylaromatic compounds.

9. Use of a device according to claim 6 for determining the activity of supported metallocene catalysts in the polymerization of alk-1-enes or vinylaromatic compounds.