DD247686A1 - PROCESS FOR THE PRODUCTION OF OLEFIN POLYMERS - Google Patents

Abstract

The invention relates to a process for the preparation of olefin polymers, in particular high density polyethylene and of ethylene copolymers, which are suitable for the production of injection molded and selected extruded products. For the inventive method, a modified Ziegler catalyst is used on organic Traegermaterialien that allows for very high activity an improved variation of the density and molecular parameters of the polymers. According to the invention, the transition metal component of the catalyst is the reaction product of an organic polymer carrier containing alkali metal-carbon bonds, first with an aluminum compound of the general formula RnAlX3n, then with an organomagnesium compound of the general formula RnMgX2n and finally with a transition metal compound of the general formula MXnYmn, in which M is a transition metal of the IV., V. or VI. Subgroup of the PSE represents.

Description

in the

R is an alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl, alkoxy, silylalkyl, alkylsilyl, amide, silylamide radical, a halo, nitrogen, phosphorus or oxygen functionalized aryl or ω-functionalized Alkyl or alkenyl radical,

X is a halogen and η is a numerical value of Obis 3, then with an organomagnesium compound of the general formula II,

RnMgX ₂ - _n Il

in the

R is an alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl, alkoxy, silylalkyl, alkylsilyl, amide, silylamide radical, a halo, nitrogen, phosphorus or oxygen functionalized aryl or terminally functionalized alkyl - or alkenyl radical means

X represents a halogen, alkoxy or carboxyl ligand and η is a numerical value of 1 to 2 and last with a transition metal compound of general formula III,

MX _n Y _m _ _n III

in the

M is a transition metal of the IV., V. or Vl. Subgroup of the PSE means

X and Y are identical or different ligands selected from halogen, cyclopentadienyl, π-allyl, carbonyl, alkyl, aryl, alkaryl, aralkyl, cycloalkyl, cycloalkenyl, cycloalkadienyl.cycloalkatrienyl, alkenyl, alkadienyl, alkoxy, aroxy, -NR'R ", - CH ₂ SiR ₃ or -N (SiR ₃ ) _{2 represent} existing ligand group, wherein R, R 'and R "were identical or different alkyl, cycloalkyl, or aryl radicals,

m is the valency of the transition metal and

η is a number between zero and m.

2. The method according to item 1, characterized in that as starting polymers for the preparation of the organic polymer carrier containing alkali metal-carbon bonds, polystyrene, polyalkylstyrene or their copolymers with monoolefins and diolefins, preferably with ethylene, divinylbenzene, ethyldivinylbenzene, preferably in the form the halogenation "of said homo- and copolymers are used.

3. The method according to item 1, characterized in that the starting polymers are used for the preparation of the organic polymer carrier in insoluble or in proton-free solvents soluble form.

4. The method according to item 1, characterized in that the polymerization is carried out in the presence of the catalyst component A contained catalyst in suspension, in solution and in the gas phase, preferably olefin polymers of ethylene, propylene and higher homologues and copolymers of ethylene preferably with Propylene, butene, hexene or norbornene.

Field of application of the invention

The invention relates to a process for the polymerization and copolymerization of olefins with modified Ziegler catalysts which are fixed on organic support materials. The invention makes it possible to produce preferably polyethylene and ethylene copolymers having improved properties in highly effective processes.

Characteristic of the known technical solutions

Ziegler catalysts for olefin polymerization have been significantly improved by attachment to supports. Thus, with catalysts on inorganic supports so high conversions are achieved that a subsequent removal of the catalyst is no longer necessary. This solved the problems associated with the residues of transition metal compound, such as discoloration of the polyolefin or aging phenomena.

Due to the partially high content of inorganic carrier substance, for. For example, magnesium chloride, but often occur corrosion phenomena on processing machines, unsatisfactory electrical properties and sometimes influencing the physico-mechanical properties. To overcome these disadvantages, it is known to replace inorganic support materials by organic. In addition to the possibility of expanding the property spectrum of the polymer products, the use of organically supported catalysts may also result in more favorable conditions for the technological design of the polymerization process. This applies in particular to gas phase polymerization, in which the physical properties of the solid catalyst in the fluidized bed are of crucial importance.

- Ζ- Λ. · * / ΟΟΟ

The described organically supported catalysts generally have only a low catalytic activity (BE-PS 552550, GB-PS 834217, DE-OS 2848907 and 2922068, FR-PS 1405371, SU-PS 473395, US-PS 4147664 and 4268418). Another shortcoming of these catalysts is the insufficient ability to vary the molecular weight, molecular weight distribution and density of the polymers.

A higher, but still hochjich behind the remaining of inorganic supported catalysts productivity is achieved by modification of polyethylene carriers with magnesium chloride in the form of an alkanol solution {US Patent 4021599) or with a Grignard compound in ether solution (RO-PS 66659). Insufficient gross copolymerization rates for industrial applications are also registered in the so-called gel-immobilized catalysts in which specially crosslinked graft polymers having complex-forming groups are treated with excess Grignard reagent and titanium tetrachloride (SU-PS 833305).

Significant progress has recently been made by reacting organic, alkali metal carbon bonds containing polymer supports with organomagnesium compounds and subsequent reaction with transition metal compounds (DDR patent application WP C 08 F / 234111/8). With these catalysts, gross turnover rates of more than 80 kgPE / gTi.hbarC ₂ H _{4 are} achieved, and thus they are suitable for the industrial production of polyolefins. At the same time essential polymer characteristics are adjustable. However, the dependent on the residual catalyst content polymer characteristics even with special polymer properties, eg. B. at high melt index, to comply, too long residence times and / or too high pressures in the polymerization are required. The adjustment of these reaction conditions causes a substantial part of the costs in the construction and operation of such facilities.

Object of the invention

The aim of the invention is to develop a process for the preparation of olefin homopolymers and copolymers with special properties and low-cost reaction conditions by means of Ziegler catalysts on organic support materials.

Explanation of the essence of the invention

The invention has for its object to use for the production of olefin polymers modified Ziegler catalysts on organic substrates, which have a very high catalyst activity and allow targeted polymers with different, preferably low molecular weights, broad density ranges, preferably high densities and very narrow molecular weight distributions to create.

The object is achieved in that the catalyst used consists of an organometallic component B and a solid catalyst component A, wherein according to the invention used for the polymerization catalyst component A of the catalyst, the reaction product of an organic polymer support containing alkali metal-carbon bonds, first with an aluminum compound the general formula I,

R _n AIX ₃ -H. I

in the

R is an alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl, alkoxy, silylalkyl, alkylsilyl, amide, silylamide radical, aryl or ω-functionalized with halogen, nitrogen, phosphorus or oxygen Alkyl or alkenyl radical,

X represents a halogen and η is a numerical value of 0 to 3, then with an organomagnesium compound of the general formula II,

RnMgX ₂ - _n Il

in the

R is an alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl, alkoxy, silylalkyl, alkylsilyl, amide, silylamide radical, a halo, nitrogen, phosphorus or oxygen functionalized aryl or terminally functionalized alkyl - or alkenyl radical means

X represents a halogen, alkoxy or carboxyl ligand and η is a numerical value of 1 to 2, for example with a Grignard compound, and finally with a transition metal compound of the general formula III,

MX _n Ym-H Ml

in the

M is a transition metal of the IV., V. or Vl. Subgroup of the PSE means

X and Y are identical or different ligands of halogen, cyclopentadienyl, π-allyl, carbonyl, alkyl, aryl, alkaryl, aralkyl, cycloalkyl, cycloalkenyl, cycloalkadienyl, cycloalkatrienyl, alkenyl, alkadienyl, alkoxy, aroxy, -NR'R ", - CH ₂ SiR ₃ or -N (SiR ₃ I _{2 represent} existing ligand groups, where R, R 'and R "are identical or different alkyl, cycloalkyl or aryl radicals,

m is the valency of the transition metal and

η is a number between zero and m.

The organometallic component B, consisting of a metal of the I. to IV. Main group or II. Subgroup of the PSE, is used to activate the catalyst component Aim excess in the gram atom ratio 10 to 600: 1, based on the transition metal, after a special pre-reaction or introduced directly into the polymerization reactor in the presence or absence of the olefin.

The amount of the transition metal attached to the catalyst component can be varied widely; it is in the range of 0.1 to 10% by weight of the catalyst component A.

Polystyrenes, polyalkylstyrenes or their copolymers with monoolefins and diolefins, preferably with ethylene, divinylbenzene or ethyldivinylbenzene, in most cases in the form of the halogenation products of the said homo- are used as starting polymers for the preparation of the organic polymer support which contains alkali metal-carbon bonds. and copolymers used. The starting polymers are according to their purpose in uncrosslinked insoluble or in proton-free solvates soluble form of low crosslinked to highly crosslinked before. The organic polymer support itself can be obtained as a function of its preparation or as a result of a grinding process in grain fractions under 50μηη to coarse powder of grain size over 500μηη. According to the invention, the olefin homopolymers and copolymers can be prepared in suspension, solution or in the gas phase.

According to the objective, the reaction temperature is in the range from 323 to 433 K, preferably 343 to 413 K, the reaction pressure in the range of 1 to 50 bar, preferably at 2 to 10 bar, and the polymerization time in the range 0.5 to 10 hours, preferably 0.5 to 3 hours, selected.

Olefin polymers of ethylene, propylene and higher homogens and also copolymers of ethylene, preferably with propylene, butene, hexene or norbornene, can be prepared by means of the process according to the invention.

embodiments example 1

a) Preparation of the titanium-containing catalyst component

2 g in tetrahydrofuran (THF) dissolved poly-p-bromostyrene (38.5 wt .-% Br) are treated at room temperature with sodium diphenyl, and then the reaction product with 1.6 g of AICI ₃ in THF is added. After several hours of stirring - still at room temperature - add 20ml of a 1.42 molar n-butyl magnesium bromide solution in THF and stirred for several hours. Then the solid phase product is filtered off and washed thoroughly successively with THF and hexane. Resuspended in hexane, the solid is reacted with 0.2 ml of TiCl ₄ . The resulting catalyst component is filtered off, washed with hexane and dried. The light-dust, light gray colored product (11.0 g) contains: 0.81 wt.% Ti, 5.82 wt.% Mg, 0.66 wt.% Al, 9.7 wt.% Cl, 31.4 wt. -% Br.

b) polymerization by means of the titanium-containing catalyst component

1) An agitated autoclave of 21 volume is charged with 11 a gasoline fraction containing 3 mmol of diethylaluminum chloride and 25.0 mg of the catalyst component of the present invention. Then, 3.0 bar of hydrogen and 3.0 bar of ethylene are injected, and the mixture is heated to 358 K with vigorous stirring. After reaching the intended temperature, the total pressure is regulated by means of ethylene to 7.0 bar, corresponding to an ethylene partial pressure of 2.1 bar and a hydrogen partial pressure of 3.7 bar and kept constant by continuous desserts for the duration of the experiment. After 1 hour, the polymerization reaction is stopped by blocking ethylene feed and rapid cooling. After the autoclave has been decompressed, the polymer is filtered off and dried. The yield of 43.4 g corresponds to a gross conversion rate of 102.1 kg PE / gTi.h barC ₂ H ₄ .

The melt index at 5kg load (MFI ₅ ) is 21.5g / 10min. The quotient of the melt indices at 5 and 2.16 kg load is 3.0; which is synonymous with a narrow distribution of molecular weight. The bulk density of the polyethylene is 301 g / l.

2) In a second polymerization experiment, 22.2 mg of the above catalyst component was used and the partial pressures of ethylene and hydrogen were adjusted to 2.5 and 3.6 bar, respectively. Under otherwise identical conditions, 51.5 g of polyethylene, corresponding to 114.6 kg of PE / g of Ti · h · barC ₂ H ₄ , were formed after 1 hour. MFI ₅ = 13.5g / 10min. Bulk density = 311 g / l.

3) A third experiment was carried out with 24.4 mg of the above-prepared catalyst component and 3 mmol of triisobutylaluminum as cocatalyst. At a reaction temperature of 358 K and at partial pressures of 3.3 bar for ethylene and 3.9 bar for hydrogen formed within 1 hour 81.4 g of polyethylene, corresponding to a catalyst productivity of 119.2 kg PE / g Ti h · barC ₂ H. ₄ . MFI ₅ = 28.1 g / 10 min. Bulk density = 315 g / l.

Example 2

, a) Preparation of the titanium-containing catalyst component

The preparation of the catalyst component corresponds to the procedure given in Example 1, but with the difference that one can act on the reaction product of poly-p-bromostyren and sodium diphenyl instead of AICI ₃ 5 ml of ethylaluminum sesquichloride. After carrying out the further preparative measures described above, 12.0 g of an ocher-colored powder having the following analytical values result:

0.65 wt% Ti, 5.39 wt% Mg, 2.94 wt% Al, 12.6 wt% CI, 27.0 wt% Br.

b) polymerization

1) The polymerization of the ethylene is carried out according to Example 1, wherein 67.1 mg of the catalyst component prepared under a) and 3 mmol of diethylaluminum chloride are used. The polymerization was carried out at 358 K under an ethylene partial pressure of 2.9 bar and a hydrogen partial pressure of 3.7 bar. After 1 hour, 83.2 g of polyethylene were formed, which corresponds to a productivity of 65.8 kg PE / gTi · h · barC ₂ H ₄ . MFI ₅ = 20.9g / 10min. Bulk density = 279g / l.

2) In a second experiment, an ethylene-hydrogen pressure ratio of 3.5 bar to 3.6 bar was applied. When 51.3 mg of the above catalyst component and 3 mmol of diethylaluminum chloride were used, 102.3 g of polyethylene were produced within 1 hour, corresponding to 87.6 kg of PE / gTi h.barC ₂ H ₄ . MFI ₅ = 10.5g / 10min. Bulk density = 293g / l.

3) A third test was carried out using 67.5 mg of the catalyst component prepared under a) and 3 mmol of triisobutylaluminum as cocatalyst under otherwise identical conditions as in the preceding experiment. In this case, 68.6 g of polyethylene were obtained in 1 hour, ie the productivity amounts to 44.7 kg PE / g of Ti h · barC ₂ H ₄ . MFI ₅ = 20.8g / 10min.

Example 3

a) Preparation of the titanium-containing catalyst component

The preparation of the catalyst component is carried out according to the procedure given in Example 1, but with the modification that is used as the aluminum compound ethylaluminum dichloride on 2 g of sodium diphenyl-treated poly-p-bromostyrene (38.5Gew .-% Br) 2ml ethylaluminum. For the further reactions, the same amounts and concentrations of Grignard solution (20 ml of 1.42 molar n-butylmagnesium bromide solution) and titanium tetrachloride (0.2 ml) are used under unchanged reaction conditions. After thorough washing with hexane and after drying, 7.5 g of a pale gray powder having the following analytical values are obtained: 1.25% by weight of Ti, 4.82% by weight of Mg, 0.97% by weight of Al, 7, 4% by weight of Cl, 32.7% by weight of Br.

b) polymerization

1) In the polymerization of ethylene carried out according to Example 1, 49.5 mg of the catalyst component prepared under a) and 3 mmol of diethylaluminum chloride were used. The partial pressures were adjusted to 3.5 bar for ethylene and 3.6 bar for hydrogen. The yield after one-hour polymerization was 81.7 g, corresponding to 37.7 kg PE / g Ti · h barC ₂ H ₄ .

MFI ₅ = 13.6g / 10min. Bulk density = 280 g / l, density = 0.961 g / cm ³ .

2) In a second experiment, 37.1 mg of catalyst component and butene-1 are added so that the comonomer content is 0.3% by volume in the liquid phase and remains constant during the polymerization. All other conditions are the same as in the previous experiment. After a polymerization time of 1 hour, 102.1 g of polyethylene, corresponding to a gross conversion rate of 62.9 kg PE / gTi.h of barC ₂ H _4, are obtained. MFI ₅ = 20.4g / 10min.

Density = 0.954 g / cm ³ .

3) Another experiment with 3 mmol triisobutylaluminum instead of diethylaluminum chloride, but under the same conditions as above, yielded 48.7 g of polyethylene using 64.7 mg of catalyst component in 1 hour, giving 17.2 kg PE / gTi.h -barC ₂ H ₄ corresponds. MFI ₅ = 12.5g / 10min.

Example 4

a) Preparation of the titanium-containing catalyst component

The procedure for the preparation of the catalyst component corresponds to that of Example 1, except that 2 g of a soluble poly-p-bromostyrene 43.5 wt .-% Br used and that acts on the reaction product with sodium diphenyl 2ml diethylaluminum chloride leaves. The introduction of organomagnesium is carried out by treating the suspended heterogeneous organoaluminum compound in THF with 10 ml of a 1.68 molar n-butylmagnesium bromide solution, and to complete the on construction of the catalyst component of the suspension of the metal complex-substituted polystyrene finally 0.6ml titanium tetrachloride is added. The gray-colored product carefully washed out with hexane and dried (3.2 g) contains: 5.00% by weight of Ti, 2.53% by weight of Mg, 1.32% by weight of Al, 16.2% by weight of Cl, 17.3% by weight Br.

b) polymerization

1) The polymerization of the ethylene was carried out according to the procedure described in Example 1 using 32.5 mg of the catalyst component prepared under a) and 3 mmol of diethylaluminum chloride. At a total pressure of 7.3 bar at 358 K, the partial pressure of the ethylene was 2.5 bar and the hydrogen partial pressure 3.6 bar. In the course of 1 hour, 70.9 g of polyethylene had been produced, which corresponds to a productivity of 17.5 kg PE / g Ti · h · barC ₂ H ₄ . MR ₅ = 27.2 g / 10 min. Bulk density = 269g / l.

2) A second experiment was carried out with 14.7 mg of catalyst component and 3 mmol of triisobutylaluminum as cocatalyst; In addition, the partial pressures of ethylene and hydrogen were adjusted to 3.1 and 3.6 bar, respectively. After a polymerization time of 1 hour, 47.3 g of polyethylene were isolated, corresponding to 20.8 kg of PE / g of Ti · h · barC ₂ H ₄ . MFI ₅ = 12.1 g / 10 min.

Example 5

a) Preparation of the titanium-containing catalyst component

The catalyst component is prepared as described in Example 1, but with the difference that bis-n-butoxytitanium dichloride is used instead of titanium tetrachloride. 2 nig with sodium diptienyl-treated poly-p-bromostyrene are reacted as usual in succession with 1.6 g of aluminum trichloride and 20 ml of a 1.42 molar THF solution of butyl-magnesium bromide, and the resulting solid-phase product is washed well with THF and hexane , Thereafter, 0.5 ml of (n-BuO) ₂ TiCl ₂ in the form of a 10% strength hexane solution is allowed to act on the solid product and the catalyst component is thoroughly washed after filtration with hexane. After drying, 9.5 g of a dust-yellow powder of the following composition remain: 0.41% by weight of Ti, 5.30% by weight of Mg, 0.9% by weight of Al, 13.3% by weight of Cl, 24.3% by weight .-% Br.

b) polymerization

1) For the test according to Example 1, 46.8 mg of the catalyst component prepared above and 3 mmol of triisobutylaluminum are used. At an ethylene-hydrogen pressure ratio of 3.5: 3.6 bar, 33.4 g of polyethylene are formed in 1 hour, which means a gross conversion rate of 49.7 kg PE / gTi.h.barC ₂ H ₄ . MFI ₅ = 10.1g / 10min.

2) In a second polymerization experiment, 86.4 mg of the above catalyst component was used, while the partial pressures of ethylene and hydrogen were adjusted to 3.1 and 3.6 bar, respectively, and instead of triisobutylaluminum, 3 mmol of diethylaluminum chloride was used. After 1 hour, 28.8 g of polyethylene were produced, corresponding to a gross conversion rate of 26.2 kg PE / g Ti · h · barC ₂ H ₄ . MFI ₅ = 2.6 g / 1 min.

Example 6

a) Preparation of the titanium-containing catalyst component

In contrast to Example 1 is used to prepare the catalyst component mono-butoxy-titanium trichloride instead of titanium tetrachloride. The amounts of AICI3 and n-BuMgBr used, as well as titanium compound, are identical to those given in Example 5. The procedure for the preparation of the catalyst component corresponds to the procedure given in Example 1. The final dry product consists of 9.3 g of a dark yellow fine powder whose analysis has the following result: 1.18 wt% Ti, 4.84 wt% Mg, 0.74 wt% Al, 10.6 wt% Cl , 31.6% by weight Br.

b) polymerization

1) The polymerization is carried out according to Example 1, wherein 43.1 mg of the catalyst component prepared under a) and 3 mmol of triisobutylaluminum are used as cocatalyst. The partial pressures were adjusted to 3.3 bar for ethylene and 3.9 bar for hydrogen. The yield of polyethylene after 1 hour of polymerization was 65.9 mg, corresponding to 39.2 kg PE / g Ti · h · barC ₂ H ₄ . MFI ₅ = 12.2g / 10min.

2) In a further experiment with 3 mmol diethylaluminum chloride instead of triisobutylaluminum and partial pressures of 3.1 bar for ethylene and 3.6 bar for hydrogen, 79.8 mg of catalyst component gave 43.5 g of polymer in 1 hour, yielding 14.9 kg PE / g Ti · h · barC ₂ H ₄ corresponds. MFI ₅ = 2.6g / 10min.

Example 7

In a 2I stirred autoclave according to Example 1 b 11 octane and 2.5 mmol of triisobutylaluminum are added. After heating to 413 K, a hydrogen pressure of 2 bar and an ethylene pressure of 4 bar is set. The addition of 16.3 mg of the catalyst prepared according to Example 1 then takes place. In the course of 1 hour 69.2 g of polymer, corresponding to a gross conversion rate of 131.1 kg PE / g Ti · h · barC ₂ H ₄ . MFI ₅ = 18.9g / 1min. Density = 0.963g / cm ³ .

Example 8

a) Preparation of the titanium-containing catalyst component

The catalyst component is prepared as described in Example 1, but poly-p-chloromethylstyrene is used in place of poly-p-bromostyrene. After the treatment of 2 g dissolved in THF poly-p-chloromethylstyrene (9.7 wt .-% Cl) with sodium diphenyl is carried out successively at a distance of several hours, the reaction with 1.6 g of aluminum trichloride and 4.6 g of n-butyl-magnesium bromide (11, 4 ml of a 2.49 molar THF solution). Subsequently, the solid-phase reaction product is washed out with THF and hexane and treated in hexane suspension with 0.2 ml of TiCl ₄ . After several hours of stirring at room temperature, it is filtered off, washed thoroughly with hexane and dried. The dust-fine, light yellow colored catalyst component (10.2 g) contains: 0.71 wt.% Ti, 4.06 wt.% Mg, 3.48 wt.% Al, 20.5 wt.% Cl, 13.3 wt. -% Br.

b) polymerization

In the polymerization carried out as in Example 1, 30.1 mg of the catalyst component prepared under a) were used. With 3 mmol of triisobutylaluminum as cocatalyst and at partial pressures of 2.9 bar for ethylene and 3.7 bar for hydrogen, 71.5 g of polyethylene were produced after 1 hour, which corresponds to a gross conversion rate of 115.2 kg PE / g Ti · h · barC ₂ H ₄ corresponds

MFI ₅ = 16.0g / 10min. Bulk density = 280g / l.

Claims (1)

Invention claim: 1. A process for the preparation of olefin polymers in the presence of a modified Ziegler catalyst of a solid catalyst component A and an organometallic component B, characterized in that the catalyst used for the polymerization catalyst component A of the catalyst, the reaction product of an organic polymer support, the alkali metal-carbon bonds contains, first with an aluminum compound of general formula I, RnAIXa-n I