DE19850898A1 - Process for the preparation of EP (D) M - Google Patents

Abstract

The invention relates to a method for producing rubber-type ethylene-propylene copolymers and ethylene-propylene non-conjugated diene terpolymers and to the use of the polymers obtained by said method for producing shaped bodies of any kind.

Description

The present invention relates to a method for producing rubber like ethylene-propylene copolymers and ethylene-propylene-non-conjugated Diene terpolymers, as well as the use of the polymers obtainable in this way Provision of all kinds of moldings.

Due to their saturated main chain, ethylene-propylene copolymers (EPM) and ethylene-propylene-non-conjugated diene terpolymers (EPDM) important ones substitutes for industry. To get their final properties, you need the polymers are cross-linked with peroxides, radiation or sulfur / sulfur agents become. The sulfur content is particularly important when it comes to sulfur crosslinking saturated bonds in the EPDM, which is due to the content of non-conjugated diene is set. Many catalysts have been developed to match the composition and tailor the microstructure of EPM and EPDM.

It is state of the art, EPM and EPDM with catalysts based on Ziegler Manufacture Natta systems. Vanadium-containing catalysts are mostly used for this gates used. The processes are in solution, suspension or the gas phase carried out.

It is state of the art to use ethylene-propylene copolymers with bis-cyclopentadienyl Produce zirconium compounds (EP-B-129 368), but the rate of incorporation is mostly non-conjugated.

From US-A-4,892,851 a compound is known in which a cyclopentadienyl Ligand (cp) with a fluorenyl ligand (flu) over a dimethylmethane bridge is linked.  

EP-A2-512 554 also teaches bridged cp-flu compounds and their use as Catalysts for the polymerization of olefins.

US-A-5,158,920 teaches bridged cp-flu compounds and their use in making them provision of stereo-specific polymers. Bridged cp-flu connections are also out other documents known, but all documents have in common that the Bridge link is a linear chain. However, the catalysts of this type show Weaknesses in the chain length of the EP (D) M obtained, so that oils or Waxes are obtained that are not technically usable.

The task was therefore to develop a process for the production of EPM and EPDM to provide that does not have the disadvantages of the prior art.

This object is achieved according to the invention by a process for the polymerization of ethylene, propylene and optionally a non-conjugated diene using a metallocene as catalyst, characterized in that a compound of the general formula (I)

in which
R ¹ to R ¹² independently of one another represent H, C ₁ -C ₁₂ alkyl, C ₆ -C ₁₂ aryl or C ₇ -C ₁₂ aralkyl radicals,
X represents H, halogen, C ₁ -C ₁₂ alkyl radicals
W represents a carbon atom or an optionally substituted atom from groups 13, 15 or 16,
Y represents C ₁ -C ₁₂ alkyl radicals or an optionally substituted atom from groups 14, 15 or 16,
M represents a Group 4 metal,
optionally used in the presence of one or more co-catalysts.

C ₁ -C ₁₂ alkyl is understood to mean all linear or branched alkyl radicals having 1 to 12 C atoms known to the person skilled in the art, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t- Butyl, n-pentyl, i-pentyl, neo-pentyl and hexyl, which in turn can in turn be substituted. Halogen or C ₁ -C ₁₂ alkyl or alkoxy, and C ₆ -C ₁₂ cycloalkyl or aryl, such as benzoyl, trimethylphenyl, ethylphenyl, chloromethyl and chloroethyl, are suitable as substituents.

C ₁ -C ₁₂ alkoxy is understood to mean all linear or branched alkoxyl radicals having 1 to 12 C atoms known to the person skilled in the art, such as methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, t-butoxy , n-pentoxy, i-pentoxy, neo-pentoxy and hexoxy, which in turn can be substituted. Halogen or C ₁ -C ₁₂ alkyl or alkoxy as well as C ₆ -C ₁₂ cycloalkyl or aryl are suitable as substituents.

C ₆ -C ₁₂ aryl is understood to mean all mono- or more nuclear aryl radicals having 6 to 12 carbon atoms known to the person skilled in the art, such as phenyl and naphthyl, which in turn can in turn be substituted. Halogen, nitro, hydroxyl, or also C ₁ -C ₁₂ alkyl or alkoxy, and also C ₆ -C ₁₂ cycloalkyl or aryl, such as bromophenyl, chlorophenyl, toloyl and nitro phenyl, are suitable as substituents here.

C ₇ -C ₁₂ aralkyl means a combination of the above alkyls with the above aryls.

The radicals R ¹ to R ¹² are preferably hydrogen, methyl, ethyl, propyl, t-butyl, methoxy, ethoxy, cyclohexyl, benzoyl, methoxy, ethoxy, phenyl, naphthyl, chlorophenyl and toloyl.

If the radicals X are halogen, the person skilled in the art understands this to be fluorine, Chlorine, bromine or iodine, chlorine is preferred.

If Y represents an atom from groups 14, 15 or 16, preference is given to this Si, Ge, Pb, N, P, O and S understood. Si, N and P are particularly preferred.

M stands for Ti, Zr and Hf, Zr is preferred.  

Catalysts of the general formula (II) are preferred

wherein
R ¹ to R ¹² independently of one another represent H, C ₁ -C ₁₂ alkyl or C ₆ -C ₁₂ aryl radicals,
X stands for Cl, methyl and
M represents Ti or Zr,
used.

The catalyst of the formula (III) is very particularly preferred

used.

The compounds of formula (I), (II), (III) are a further subject of the Er finding.

The compounds of formula (I), (II), (III) are the poly of the invention merization is often used in combination with cocatalysts. As cocatalyst the cocatalysts known in the field of metallocenes come into play Question how polymeric or oligomeric alumoxanes, Lewis acids and aluminates and Borates. In this context, reference is made in particular to Macromol. Symp. Vol. 97, July 1995, pp. 1-246 (for alumoxanes), and on EP 277 003, EP 277 004, Organometallics 1997, 16, 842-857 (for borates) and EP 573 403 (for Aluminates). Particularly suitable as cocatalysts are methylalumoxane Triisobutylaluminum (TIBA) modified methylalumoxane, as well as diisobutyl alumoxane, trialkylaluminium compounds such as trimethylaluminium, triethylalu minium, triisobutylaluminium, triisooctylaluminium, in addition dialkylalu minium compounds such as diisobutyl aluminum hydride, diethyl aluminum chloride, substituted triarylboron compounds such as tris (pentafluorophenyl) borane, and ionic compounds which contain tetrakis (pentafluorophenyl) borate as the anion, such as Triphenylmethyltetrakis (pentafluorophenyl) borate, trimethylammonium tetrakis (penta fluorophenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, substi  tuated triarylaluminum compounds, such as tris (pentafluorophenyl) aluminum, and ionic compounds which contain tetrakis (pentafluorophenyl) aluminate as the anion, such as triphenylmethyltetrakis (pentafluorophenyl) aluminate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) aluminate.

Of course, it is possible to mix the cocatalysts with one another to use. The most favorable mixing ratios are suitable To determine preliminary tests.

The polymerization according to the invention is carried out in the gas, liquid or slurry (Suspension) phase executed. The temperature range for this ranges from -20 ° C to + 200 ° C, preferably 0 ° C to 160 ° C, particularly preferably + 20 ° C to + 80 ° C; the Pressure range is from 1 to 50 bar, preferably 3 to 30 bar. Poly used For example, inert solvents are: saturated aliphatics or (Halogen) aromatics, such as perltan, hexane, heptane, cyclohexane, petroleum ether, petro leum, hydrogenated petrol, benzene, toluene, xylene, ethylbenzene, chlorobenzene and analog. These reaction conditions for the polymerization are known to the person skilled in the art basically known.

The polymerization according to the invention is preferably carried out in the presence of inert organic solvents. As an inert, organic solvent For example, aromatic, aliphatic and / or cycloalipha are suitable table hydrocarbons, such as preferably benzene, toluene, hexane, pentane, heptane and / or cyclohexane. The polymerization is preferred as solution polymerization or operated in suspension.

In a further preferred embodiment, the method according to the invention ren carried out in the gas phase. Polymerization of olefins in the gas phase was technologically first realized in 1962 (US 3.023.203). Ent Talking fluid bed reactors have long been state of the art.  

The organometallic compound of formula (I), (II), (III) and optionally the When used in suspension or gas phase, cocatalyst is also applied to one inorganic carriers applied and used heterogenized. As inert anorga African solids are particularly suitable for silica gels, clays, aluminosilicates, talc, Zeolites, carbon black, inorganic oxides such as silicon dioxide, aluminum oxide, magnesium oxide, titanium dioxide, silicon carbide, preferably silica gels, zeolites and carbon black. The ge called inert, inorganic solids can be used individually or in a mixture each other. In another preferred embodiment organic carriers individually or in a mixture with one another or with inorganic Carriers are used. Examples of organic carriers are porous polystyrene, porous polypropylene or porous polyethylene.

All dienes known to the person skilled in the art come in as non-conjugated diene Question whose double bonds have different reactivities to the one catalyst system such as 5-ethylidene-2-norbornene (ENB), 5-vinyl norbornene, 1,4-hexadiene and dicyclopentadiene. 5-Ethylidene-2- is preferred norbornene and 1,4-hexadiene.

It can be advantageous to remove contaminants such as oxygen, Clean water or polar substances. Generally the polymerization operated under inert conditions.

The rubber-like EPM and EPDM that can be produced according to the invention are distinguished by a low crystalline fraction. In general, the crystalline fraction is below 30%, preferably below 20%, particularly preferably below 10%, very particularly preferably in the range from 0 to 10%. The crystalline fraction can be determined by measuring the enthalpy of fusion and using the DSC method. The following factor has proven itself:

The uncrosslinked EPM and EPDM are readily soluble in common solvents such as Hexane, heptane or toluene.

The ethylene content is in the range from 5 to 95% by weight, preferably 40 to 90% by weight.

The propylene content is in the range from 5 to 95% by weight, preferably 9.5 to 59.5% by weight.

The content of non-conjugated diene is in the range from 0 to 20% by weight, preferably 0.5 to 12% by weight.

It is trivial that the individual proportions of the monomers add up to 100% must and a specialist accordingly from the individual wt .-% - Be rich will be sensibly selected.

It is a particular advantage of the process according to the invention that the catalyst can remain in the end product and not during further processing or Use disturbs.

The further processing of the EPM and EPDM that can be produced according to the invention usually includes a crosslinking step with peroxides, sulfur / sulfur donors or high-energy radiation. This step is known to the person skilled in the art this point, however, expressly on "Handbook for the rubber industry, ed. Bayer AG, Leverkusen, 2nd edition, 1991, pp. 231 ff ". The EPM and EPDM can also be stretched with oils if desired.

The use of the rubber-like EPM and EPDM for the production of moldings of all kinds is another subject of Invention.  

The following may be mentioned as shaped bodies: seals, O-rings, profiles, plates, coatings for other materials and damping elements.

For applications in the low temperature range it can be advantageous to use products a crystallinity in the range of 0 to 5%.

Of course, it is possible to use the rubber-like EPM and Use EPDM in a mixture with other polymers or rubbers, such as SBT, BR, CR, NBR, ABS, HNBR, polyethylene, polypropylene, polyethylene copolymers, LD-PE, LLDPE, HMWPE, polysiloxanes, silicone rubbers and fluorine rubbers. Corresponding mixtures are known to the person skilled in the art and can can be optimized by a few trials.

It can also be advantageous to add fillers, such as carbon black, silica, talc, Silicas and metal oxides. These fillers and their use are the Known expert, but it is expressly on Encyclopedia of Polymer Science and Engineering, Vol. 4, p. 66 ff.  

Examples

All work up to polymer processing was carried out in an inert gas atmosphere Performed using Schienk, syringe and glovebox techniques. As Inert gas was made from Linde's argon with a purity of ≧ 99.996% turns, which by means of an Oxisorb cartridge from Messer-Griesheim, DE was cleaned. For polymerizations and for the preparation of catalyst and cocatalyst stock solutions toluene was used by Riedel de-Haen, DE related to a purity ≧ 99.5%. It was several days pre-dried over potassium hydroxide, degassed, at least for a week Sodium / potassium alloy heated under reflux and finally ready for use distilled.

example 1 Preparation of 1,3,3-trimethyl-2,3-dihydropental

600 ml of methanol, 50 ml (0.61 mol) of freshly distilled cyclopentadiene and 75 ml (0.61 mol) of diacetone alcohol are placed under argon in a 1-IN ₂ flask. After the mixture has been heated to 0 ° C., 80 ml of freshly distilled pyrrolidine are added. After warming to room temperature, the mixture is stirred for 18 hours. The intensely yellow colored solution is concentrated to 200 ml and distilled through a 30 cm Vigreux column. At an oil bath temperature of 130 to 160 ° C 16.9 g of a yellow-orange, viscous oil (distillation temperature 64 to 70 ° C) are isolated in an oil pump vacuum. This fraction is distilled over a mirrored 25 cm canned column. At an oil bath temperature of 150 ° C at 11 mbar and a distillation temperature of 66 to 69 ° C, 2.1 g (14 mmol) of the desired product are obtained. The ¹ H-NMR spectrum shows a product to 6,6-dimethylfulvene ratio of 5 to 1.
¹ H-NMR (100 MHz, CDCl ₃ , J [Hz], TMS):
δ [ppm]: 6.72 (1 H, d, ³ J = 5.0, olefin. Cp proton)
6.06 (2 H, dd, ³ J = 5.0, ⁴ J = 0.8, olefinic Cp protons)
2.82 (2 H, s, methylene protons)
2.14 (3 H, s, methyl protons)
1.26 (6 H, s, methyl protons)

Example 2 Preparation of 1-fluorenyl-1,3,3-trimethyl-1,2,3,6-tetrahydropentalene

In a 250 ml N2 flask with dropping funnel and reflux condenser, 9.56 ml (15.3 mmol) is added to a mixture of 2.54 g (15.3 mmol) of fluorene in 50 ml of THF at -50 ° C. within 30 minutes. a 1.6 N solution of n-butyllithium in hexane. After warming to room temperature, the solution is stirred for a further eight hours and then briefly heated to boiling. After cooling to -50 ° C., 1.68 g (11.5 mmol) of 1,3,3-trimethyl-2,3-dihydropentalene in 20 ml of THF are added dropwise in two hours and the mixture is stirred at room temperature overnight. After boiling briefly, 20 ml of semi-concentrated hydrochloric acid are added. The lower, aqueous phase is saturated with NaCl and extracted with diethyl ether. The combined organic phases are washed twice with 20 ml of saturated NaCl solution. It is then dried over Na ₂ SO ₄ . After complete condensation of the solvent on a rotary evaporator, 5.0 g of crude product are obtained as an orange-yellow, viscous oil. The ligand is purified by column chromatography (silica gel 60; particle size 0.015-0.040 mm; petroleum ether 60/70).
Yield: 1.10 g (3.5 mmol; 30% based on the pentalen)
¹ H-NMR (100 MHz, CDCl ₃ , TMS):
δ [ppm] 7.83-6.97 (8 H, m, aromatic protons)
6.65-6.32 (2 H, m, olefin. Cp proton)
4.05 (1 H, s, aliphatic fluorene proton)
3.40, 3.02, 2.72 (2 H, m, aliphatic Cp protons)
1.73, 1.69 (3 H, s, methyl protons, 2 isomers)
1.34-1.18 (2 H, m, methylene protons)
0.98 (3 H, s, methyl protons)
0.30 (3 H, s, methyl protons)
Mass spectrum: m / z 312 (Molpeak)

Example3 Preparation of [1- (η ⁵ -fluorenyl) -1,3,3-trimethyl-η ⁵ -tetrahydropentalenyl] zirconium dichloride

To a mixture of 1.1 g (3.2 mmol) of 1-fluorenyl-1,3,3-trimetyl-1,2,3,6-tetra hydropentalene in 25 ml of THF, 4.4 ml (8.0 mmol ) a 1.8 molar solution of n-butyllithium in hexane. The mixture is briefly heated to boiling after four days. After the solvent has completely condensed, the precipitate formed is washed twice with 10 ml each of pentane. After decanting the pentane, 0.75 g (3.2 mmol) of zirconium tetrachloride and 35 ml of pentane at -60 ° C are added. The mixture is stirred for three and a half days at room temperature. After decanting the pentane, the residue is extracted with a total of 60 ml of dichloromethane. After concentrating the solution, 1.94 g of crude product are obtained. After recrystallization from dichloromethane, 150 mg (0.3 mmol, 10% based on zirconium tetrachloride) of the product are obtained as a crystalline, red, light-sensitive solid. (X-ray structure analysis: Fig. 3)
Mass spectrum: m / z 472 (Molpeak)

Polymerization

Methylaluminoxane from Witco was used as the cocatalyst. This was used as a toluene solution with a concentration of 100 mg / ml.

The gaseous monomers ethene (Linde) and propene (Gerling, Holz & Co.) used have purities ≧ 99.8%. Before being introduced into the reactor, they were passed through two cleaning columns in order to remove oxygen and traces of sulfur. The two columns had a dimension of 3,300 cm ³ , an operating pressure of 8.5 bar, an operating temperature of 25 ° C and ensured a volume flow of approx. 10 l / min. The first column was filled with Cu catalyst (BASF R3-11) and the second with molecular sieve (10 Å).

The 5-ethylidene-2-norbornene (ENB) was a mixture of the endo and exo forms with a purity of ≧ 99% from Aldrich, degassed, one week with n-Tributylaluminum (Witco, 20 ml to 1 l ENB) stirred and condensed.

execution

First, the equipment was checked for leaks, both a applied vacuum as well as a given argon pressure of 4 bar several Minutes had to remain constant. Only then was an hour at 95 ° C under oil pump vacuum heated. Then the reactor was on the reaction temperature brought to 30 and 60 ° C and loaded. The temperature was during of the reaction with an accuracy of ± 1 ° C.

For the terpolymerizations, 500 ml of toluene and 10 ml MAO solution submitted, then the required amount of the liquid Monomers (ENB) added. The solution was first made with propene, then with Ethene saturated. When saturation was reached, the polymerization was initiated by injection the metallocene solution started. Ethene was replenished during the reaction, so that the total pressure remained constant during the reaction, the monomers composition of the approach but constantly changing. Hence the reactions low sales canceled. The reaction was stopped by the Kataly sator destroyed by injecting 5 ml of ethanol and the gaseous mono were carefully released into the fume cupboard.

A 1.0.10 ^-3 molar toluene stock solution of the respective catalyst compound was used for the polymerization.

Trials 4 to 9

The product from Example 3 became the catalyst compound in homogeneous form used.

The monomer composition of the experiment, the partial pressures of the individual Monomers and the reaction temperatures are shown in Table 1.

Experiment 10 (comparative experiment)

It was used as a catalyst compound (CH ₃ ) ₂ C cp flu ZrCl ₂ in homogeneous form.

The monomer composition of the experiment, the partial pressures of the individual Monomers and the reaction temperatures are shown in Table 1.

Table 1

Batch compositions

The toluene polymer solutions from Run 4-10 were removed from the reactor removed and stirred overnight with 200 ml of aqueous 5% hydrochloric acid. The toluene phase was separated off with 50 ml of saturated sodium bicarbonate neutralized solution and three times with 100 ml dist. Washed water. After extensive removal of the toluene and the liquid monomer on the rotation evaporator at 30 ° C and 40 mbar was attempted to add the polymer Precipitate 100 ml of ethanol. If this succeeded, the polymer was removed from the solution  removed and dried; if the polymer remained a highly viscous liquid, so did that remaining toluene and monomer and the ethanol on the rotary evaporator pulled and then dried the polymer. Drying took place overnight 60 ° C in an oil pump vacuum.

Polymer analysis

An Ubbelohde viscometer (capillary 0a, K = 0.005) tempered to 135 ° C was used to measure the viscosity weight average M _η . The solvent used was decahydronaphthalene (decalin), which was provided with 1 g / l of 2,6-di-tert-butyl-4-methylphenol as a stabilizer. The throughput times were measured with a Viskoboy 2.

To prepare the polymer solution, 50 mg of the polymer were mixed with 50 ml of Deca hydronaphthalene added, in a closed flask without stirring at 135 ° C Dissolved overnight and filtered hot before measurement. For cleaning the capillary it was rinsed twice with polymer solution. The measurements were taking so long repeats until constant values are obtained or until one for an average value education sufficient number of measured values was available.

The molecular weights M _η for the EP and the EPDM were calculated using the Mark-Houwink constants for PE: k = 4.75.10 ^-4 , a = 0.725.

Table 2

Activities and molecular weights M _η

In order to be able to compare the molecular weights of the EP with comparative values for dimethyl methane bridged cp flu ZrCl ₂ (M. Arndt, W. Kaminsky, A.-M. Schauwienold, U. Weingarten; Macromol. Chem. Phys. 199 1135 (1998)), the correction proposed by Scholte (TG Scholte, NLJ Meijerink, HM Schoffeleers, AMG Brands; J. Appl. Polym. Sci. 29 (1984) 3763) was made. The comparisons are shown in Fig. 1 and Fig. Graphically represented. 2

There are significantly higher molecular weights when using the invention Procedure (4-9) compared with the literature values.  

The different installation rates are shown in Table 3:

Table 3

Product composition

It is a much better propene incorporation in trial 4 than in trial 10 to deliver.

The DSC measurements for determining the melting range T _m , melting enthalpy ΔH _m and glass transition temperature T _g were carried out with a DSC 821e from Mettler-Toledo. The calibration was carried out with indium (T _m = 156.6 ° C). For the measurement, 5-20 mg of substance were weighed into aluminum pans and measured at a heating rate of 20 ° C / min in the temperature range from -100 ° C to 200 ° C. From the data obtained by heating twice with intervening cooling (-20 ° C / min), that of the second heating was used.

The values are summarized in Table 4:

Table 4

DSC values of the products

Claims (12)

1. A process for the polymerization of ethylene, propylene and, if appropriate, a non-conjugated diene using a metallocene as catalyst, characterized in that a compound of the general formula (I) is used as the metallocene
in which
R ¹ to R ¹² independently of one another represent H, C ₁ -C ₁₂ alkyl, C ₆ -C ₁₂ aryl or C ₇ -C ₁₂ aralkyl radicals,
W represents a carbon atom or an optionally substituted atom from groups 13, 15 or 16,
X represents H, halogen, C ₁ -C ₁₂ alkyl radicals
Y represents C ₁ -C ₁₂ alkyl radicals or an optionally substituted atom from groups 14, 15 or 16,
M represents a Group 4 metal,
optionally in the presence of one or more cocatalysts. 2. The method according to claim 1, characterized in that Y for a coal substance atom stands. 3. The method according to claim 2, characterized in that W for a coal substance atom and X represents a halogen atom. 4. The method according to one or more of claims 1 to 3, characterized records that as non-conjugated diene 5-ethylidene-2-norbornene or 1,4- Hexadiene is used. 5. The method according to one or more of claims 1 to 4, characterized records that the polymerization is carried out in solution. 6. The method according to one or more of claims 1 to 4, characterized records that the polymerization is carried out in suspension. 7. The method according to one or more of claims 1 to 4, characterized records that the polymerization is carried out in the gas phase. 8. The method according to one or more of claims 1 to 7, characterized records that the compound of general formula (I) in supported form is used. 9. The method according to one or more of claims 1 to 8, characterized records that an alumoxane is used as cocatalyst.   10. The method according to one or more of claims 1 to 9, characterized is characterized in that one or more borates is used as cocatalyst. 11. Compound of the general formula (I)

in which
R ¹ to R ¹² independently of one another represent H, C ₁ -C ₁₂ alkyl, C ₆ -C ₁₂ aryl or C ₇ -C ₁₂ aralkyl radicals,
W represents a carbon atom or an optionally substituted atom from groups 13, 15 or 16,
X represents H, halogen, C ₁ -C ₁₂ alkyl radicals
Y represents C ₁ -C ₁₂ alkyl radicals or an optionally substituted atom from groups 14, 15 or 16,
M represents a Group 4 metal. 12. Use of the in a method according to one or more of the Claims 1 to 10 producible ethylene-propylene copolymers or ethyl len-propylene-non-conjugated diene terpolymers for the production of All kinds of molded articles.