DD247352A3 - PROCESS FOR THE PRODUCTION OF OLEFIN POLYMERS - Google Patents

Abstract

The invention relates to a process for the preparation of olefin polymers, in particular of polyethylene and ethylene copolymers, the u. a. can be used for the production of household items, transport containers, films and pipes. For the inventive method, a modified Ziegler catalyst is prepared and used on organic carrier materials, which is characterized in particular by a high activity. The transition metal component of the catalyst is the reaction product of an organic polymer support containing alkali metal-carbon bonds with an organomagnesium compound, e.g. B. a Grignard compound, and the compound of a transition metal of the IV., V. or VI. Subgroup of the PSE.

Description

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 with high catalyst activities.

Characteristic of the known technical solutions

The activity of the Ziegler catalysts for olefin polymerization has been significantly improved by the attachment to carriers.

With catalysts on inorganic supports so high activities are achieved (20-50 kg polymer / g Ti · h · bar C _n H _2n ) that a subsequent removal of the transition metal compound is no longer required. The problems associated with the residues of transition metal compound, such as discoloration of the polyolefin or aging phenomena, have been solved. Due to the sometimes high content of inorganic carrier substance (eg magnesium chloride), however, often corrosion phenomena occur on processing machines, unsatisfactory electrical properties and sometimes an influence on the physico-mechanical properties.

It is known to replace inorganic support materials with organic. In addition to overcoming the disadvantages mentioned for the inorganic supported catalysts, it is also possible to extend the property spectrum of the polymer products. Moreover, the use of organically supported catalysts may result in more favorable conditions for the technological design of the polymerization processes. 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.

In a group of known organically supported catalysts, all or initially the transition metal compound is absorbed on the surface of inert supports. According to BeIg. Patent 552,550, the dissolved transition metal compound is deposited by reduction with the organoaluminum compound as a solid on polyethylene.

The fixation of the transition metal compound by chemical reaction with functional groups of the organic carrier has also been described. The transition metal compound is linked to the support via an oxygen, nitrogen or phosphorus-containing functional group or via an olefin bond. According to GB-PS 834217 titanium tetrachloride or titanium ester chlorides with polyglycols or polyalcohols, for. As cellulose, reacted and used after activation with diethylaluminum chloride for ethylene polymerization. Homopolymers such. As polycarboxylic acids, polyamides (DE-OS 1,745,420) or polyacrylonitrile (DE-OS 1770581) are known as support materials. In order to better control the coverage of the carrier with the transition metal, copolymers of olefins and vinyl derivatives containing nitrogen, oxygen or phosphorus functions were used (FR-PS 1 405 371, DE-OS 2848907). There is a more or less intense interaction between the functional groups of said vinyl derivatives and the transition metal compound, and the heteroatom content is representative when the respective vinyl derivatives are grafted onto polyolefin powder (DD-PS 126655, US-PS 4147664; 25, [1980] 349). With these catalysts Grossopolymerisationsgeschwindigkeiten of only 2 kg PE / g metal · h · bar C ₂ H ₄ could be achieved. Furthermore, the modification of polyethylene carriers by loading with magnesium chloride in the form of an alkanol solution is known (US-PS 4021 599, DE-OS 2716256). With these catalysts, a productivity of 10kg-PE / gTi · h should be achievable.

-I- £ ΆΙ

Recently, so-called gel-immobilized catalysts have been described for the high-temperature polymerization of ethylene (Vysokomol Soedin A22 [1980] 345). Thereafter, the hydroxyl and carboxyl groups of the vinyl compounds grafted on specially crosslinked supports are treated with an excess of Grignard reagent. Titanium tetrachloride. chemisorbed and the obtained heterogenized complex with organoaluminum activated. Although advantages are registered with regard to special applications, the gross copolymerization rates achieved of a maximum of 3 kg PE / g Ti · h at 20 bar are absolutely insufficient for industrial application.

The known catalysts on organic carrier material do not meet the modern technical development of polyolefins. A major disadvantage is their low activity.

Object of the invention

The aim of the invention is to provide a suitable for the polymerization and copolymerization of olefins Ziegler catalyst on organic support materials available, which has such high catalyst activities that removal of the residual catalyst can be omitted from the polymer.

Explanation of the essence of the invention

The technical problem solved by the invention

The invention has for its object to develop a process for the preparation of olefin polymers, are used in the modified Ziegler catalysts of a solid catalyst component A and an organometallic component B, which have such a high catalytic activity that the catalyst residue removal can be omitted and a industrial applicability is ensured.

Features of the invention

According to the invention the object is achieved in that the catalyst component A of the catalyst used, the reaction product of an organic polymer support containing alkali metal-carbon bonds, with an organomagnesium compound of the general formula R _n Mg X ₂ . _n , in which R is an alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl, silylalkyl, alkylsilyl, amide, silylamide radical, one with halogen,

X represents a halogen, alkoxy or carboxyl ligand, and η is a numerical value of 1-2, for example a Grignard compound, and a transition metal compound of the general formula MX _n Ym-n is in the

M is a transition metal of the IV., V. or Vl. Subgroup of the PSE, X and Y means the same or different ligands consisting of halogen, -OR, NR'R ", - CH ₂ SiR ₃ or-NSi ₂ R ₆ existing

Represent ligand group, where R, R ', R "are the same or different alkyl, cycloalkyl or aryl radicals, m is the valence of the transition metal and η is a number between zero and m.

Polystyrene, polyalkylstyrene or their copolymers with monoolefins or diolefins, preferably with ethylene, divinylbenzene, diisopropenylbenzene or ethyldivinylbenzene, which are present in uncrosslinked to highly crosslinked form, in fine distribution or as coarse powder, can be used as organic polymer supports. 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 in excess, preferably in the gram atom ratio 10-200: 1, based on the transition metal, after a specific pre-reaction or added directly to the polymerization reactor in the presence or absence of the olefin.

The amount of the transition metal fixed on the catalyst component A can be varied widely. However, it is preferably in the range of 0.1-10 wt .-% of the catalyst component A.

The preparation of the olefin polymers from ethylene, propylene and higher homologs and the copolymers of ethylene with propylene and higher olefins can be carried out in suspension, solution or in the gas phase. According to the desired procedure, the reaction temperature in the range 323-433 K, preferably at 323-393 K, the reaction pressure in the range of 1-50bar, preferably at 2-30 bar, and the polymerization time in the range 0.5-1Oh, preferably 1 -3h, elected.

embodiments example 1

a) Preparation of the titanium-containing catalyst component

10 g of finely powdered (<63 / xm) poly-sodium methylstyrene-divinylbenzene (5.5% DVB) 2.5 mg equiv. Na / g substance), prepared according to DD-WP 128874, are suspended in tetrahydrofuran (THF) and mixed at room temperature with vigorous stirring with 30 ml of a 1 molar solution of isobutylmagnesium bromide. After stirring for six hours, the solid-phase reaction product is washed thoroughly first with THF and then with hexane. The hexane-suspended heterogeneous organomagnesium compound is then reacted with 4.5 g of TiCl ₄ . Then the reaction product is filtered off and washed with hexane. The dusty product (19.5 g) resulting after drying contains 4.09 wt% Ti, 1.92 wt% Mg, 10.3 wt% Cl, and 17.9 wt% Br.

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

A stirred autoclave of 21 volumes is charged with 11 hexanes containing 3.0 mmol of triisobutylaluminum (TIBA) and 6.7 mg of the catalyst component of this invention. Then 2 bar of hydrogen and 4 bar of ethylene are pressed on, and the mixture is heated to 358 K with vigorous stirring. After reaching the intended temperature is

the total pressure was controlled by ethylene to 9 bar, corresponding to an ethylene partial pressure of 4.4 bar, and kept constant by continuous dessication 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 104.1 g corresponds to a productivity of 86.3 kg PE / gTi-h-barC ₂ H ₄

The melt index at 5kg load (MFi ₅ ) is 4.5g / 10min.

Example 2

a) Preparation of the titanium-containing catalyst component

10 g of a poly-lithium methylstyrene-divinylbenzene (5.5% DVB) with particle sizes between 63 and 80 / um and a content of 2.7mg equiv. Li / g substance, which were prepared according to the instructions given in DD-WP 128874, are at room temperature in THF with 32.5 ml of a secolar sec. Butyimagnesiumchloridlösung implemented. The at least 6 hours well mixed suspension is then washed thoroughly with THF and after complete displacement of the ether by hexane in this solvent with 5 g of TiCl _{4 is} added. After several hours of stirring at room temperature, the solid product is filtered off and dried. Analysis of the powder (18.7 g) yielded 6.40 wt% Ti, 2.08 wt% Mg, and 15.4 wt% Cl.

b) polymerization

The polymerization of the ethylene is carried out according to Example 1 using 14.2 mg of the catalyst component prepared under a) and 3.0 mmol of TIBA. In addition, the polymerization is carried out at 5.2 bar in the absence of hydrogen, which corresponds to an ethylene partial pressure of 3.0 bar. After 1 hour, 117.7 g of polyethylene were formed, corresponding to 43.1 kg PE / g Ti · h · bar C ₂ H ₄ .

Example 3

a) Preparation of the titanium-containing catalyst component

The preparation of the catalyst component corresponds to the procedure given in Example 2, but with the difference that a poly-Iithiummethylstyrendivinylb'enzen (5.5% DVB) is used as the carrier material whose particle sizes are between 90 and 125μ, ιη. The final catalyst component (17.3 g) contains 6.46 wt% Ti, 2.26 wt% Mg, and 20.55 wt% Cl.

b) polymerization

The polymerization is carried out in the same manner as in Example 2, using 12.3 mg of the titanium-containing solid product prepared under a) and 3.0 mmol of TI BA. Within one hour, 60.5 g of polyethylene formed, corresponding to 25.4 kg PE / g Ti · h · bar C ₂ H ₄ .

Example 4

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 phenylmagnesium bromide is used as the organomagnesium compound. After thorough washing with hexane and after drying 17.5 g of a product with 4.42 wt.% Ti. 1.89 wt.% Mg, 12.2 wt.% CI and 15.25 wt.% Br received.

b) polymerization

1. The polymerization is carried out according to the procedure in Example 1, wherein 21.3 mg of the catalyst component prepared under a) and 3.0 mmol of TIBA are used. The polymerization was carried out at 358 K under an ethylene partial pressure of 2.4 bar and a hydrogen partial pressure of 2.2 bar. After 2 hours, 117.8 g of polyethylene were produced, which corresponds to a productivity of 26.1 kg PE / g Ti -h-bar C ₂ H ₄ . MFI ₅ = 20,6g / 10 min.

2. In a second experiment, an ethylene-hydrogen pressure ratio of 5.5 bar to 1.3 bar was applied and polymerized at 370K. Using 12.4 mg of the above catalyst component and 3.0 mmol of TIBA produced within 1 hour 125.2 g of polyethylene, corresponding to 41.4 kg PE / g Ti · h · bar C ₂ H ₄ · MFI ₅ = 5.3 g / 10 min ,

3. A third experiment was carried out with 14.4 mg of the above-prepared catalyst component and 3.0 mmol of diethylaluminum chloride. At a reaction temperature of 358 K and at partial pressures of 3.7 bar for ethylene and 3.7 bar for hydrogen formed within 1 hour 76.7 g of polyethylene, corresponding to a catalyst productivity of 32.4 kg PE / g Ti · h barC ₂ H. ₄ . MFI ₅ = 30.7g / 10min.

Example 5

a) Preparation of the titanium-containing catalyst component

The procedure for the preparation of the catalyst component corresponds to that of Example 1, but with the modification that Dodecylmagnesiumbromid is used in place of Isobutylmagnesiumbromid. The as-usual purified and dried synthesis product contains 4.56 wt% Ti, 1.76 wt% Mg, 12.25 wt% CI, and 13.7 wt% Br.

b) polymerization

In the polymerization carried out according to Example 1, 11.8 mg of the catalyst component prepared under a) and 3.0 mmol of TIBA were used. The partial pressures of ethylene and hydrogen were adjusted to 3.6 bar. Yield after two-hour polymerization 66.9 g, corresponding to 17.2 kg PE / g Ti · h · bar C ₂ H ₄ . MFI ₅ = 16,8g / 10min.

Example 6

a) Preparation of the titanium-containing catalyst component

5.6 g of a finely powdered Η63μΓη) sodium methylstyrene-divinylbenzene copolymer (10% DVB) with 2.0 mg equiv. Na / g substance are mixed in THF at room temperature with 12 ml of a 1 molar n-butylmagnesium bromide solution and well mixed for 6 hours.Then the reaction product is filtered off, washed with THF and treated with hexane until the THF is completely displaced Hexane suspension of the heterogeneous, organomagnesium compound 1.22 g of TiCl _4. After the mixture had been stirred vigorously for 2 hours, it was filtered off and the filter residue was washed with hexane and dried. Analysis of the dusty powder (8.6 g) yielded 3.49% by weight. Ti, 2.51% by weight Mg, 10.4% by weight

b) polymerization

1. Polymerization is carried out according to Example 1; 11.7 mg of the catalyst component prepared under a) and 3 mmol of TIBA are used, and polymerization is carried out at an ethylene partial pressure of 3.7 bar at a total pressure of 9.5 bar. After a reaction time of 1 hour 43.7 g of polyethylene are isolated, corresponding to 28.8 kg PE / gTi hbar C2H4.

2. A second polymerization experiment with 3mmol diethylaluminum chloride instead of TIBA but under the same conditions as above, yielded 127.1 g of polyethylene using 31.4 kg PE / g Ti · h bar C ₂ when using 15.4 mg catalyst component in 2 hours H ₄ corresponds. MFI ₅ = 13.2 g / 10 min.

3. A third experiment using 9.5 mg of the above catalyst component and 3 mmol of TIBA was carried out at a reaction temperature of 328 K and partial pressures of 2.4 bar for ethylene and 3.6 bar for hydrogen. In this case, 31.8 g of polyethylene were obtained in 60 minutes, ie the productivity amounts to 40.2 kg PE / g Ti · h · bar C ₂ H ₄ -MFl ₅ = 1.0 g / 10 min.

Example 7

a) Preparation of the titanium-containing catalyst component

10 g of poly-lithium methylstyrene crosslinked with 2% divinylbenzene (3.24 mg of equiv. Li / g of substance) whose particle sizes are below 50 / xm by the production process are reacted in THF suspension with 35 ml of a 1 molar n-hexylmagnesium chloride solution. After stirring at room temperature for at least six hours, the mixture is filtered and the residue is washed first with THF and later with hexane until complete removal of excess Grignard reagent and the ether. Subsequently, the hexane slurry of the heterogeneous organomagnesium compound is added with stirring 4.3 g of TiCl ₄ and thoroughly mixed for three hours. Then the solid product is separated by filtration, washed several times with hexane and dried. Yield 16.3g; Analysis of the dust-free catalyst component gave 6.64 wt% Ti, 2.48 wt% Mg, and 19.05 wt% Cl.

b) polymerization

The polymerization of ethylene is carried out according to Example 1, using 6.6 mg of the catalyst component prepared under a) and 3 mmol of TIBA. The yield of polymer after two hours reaction was 98.0g; corresponding to 25.3 kg PE / g Ti · h · bar C ₂ H ₄ . MFI ₅ = 11.9g / 10min.

Example 8

a) Preparation of the titanium-containing catalyst component

6 g micronized (<t 63 / μm particle size) poly-sodium methylstyrene divinylbenzene with a crosslinker content of 25% DVB, containing 2.05 mg equiv. Na / g substance, in THF suspension with 13mmol in 10ml THF dissolved sec. Butylmagnesium chloride reacted at room temperature. After stirring for one day, the solid product is filtered off and initially washed thoroughly with THF and later with hexane. Then, 1.31 g of TiCl ₄ dissolved in hexane is allowed to act on the polystyrene-magnesium compound by stirring the mixture for 1.2 hours at room temperature. It is then filtered off, the residue is washed with hexane and dried. The dust-free product (7.7 g) contains 4.27% by weight of Ti, 1.76% by weight of Mg and 15.05% by weight of Cl.

b) polymerization

The polymerization is carried out in the same manner as in Example 1, using 11.8 mg of the above-prepared catalyst component and 4 mmol of TIBA. After a reaction time of 1 hour, 37.8 g of polyethylene were produced, which corresponds to a productivity of 17.2 kg PE / gTi h bar C ₂ H ₄ .

Claims (4)

Invention claim: A process for producing olefin polymers by using a modified Ziegler catalyst of a solid catalyst component A and an organometallic component B, characterized in that the catalyst component A, the reaction product of an organic polymer support containing alkali metal-carbon bonds, with an organomagnesium compound the general formula R _n Mg X ₂ - _n , in the R is an alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl, silylalkyl, alkylsilyl, amide, silylamide radical, a halo, nitrogen, phosphorus or oxygen functionalized aryl or ω-functionalized alkyl or Alkylene radical means X represents a halogen, alkoxy or carboxyl ligand and η is a numerical value of 1-2, and a transition metal compound of the general formula MX _n Y _m - _n , in which M is a transition metal of IV, V or VI. Subgroup of the PSE means X and Y represent identical or different ligands of the ligand group consisting of halogen, -OR, -NR'R ", -CHaSiRa or -NSi ₂ Re, where R, R ', R" are identical or different alkyl, cycloalkyl or aryl radicals stand, 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 the organic polymer carrier of polystyrene, polyalkylstyrene or their copolymers with mono- or diolefins, preferably ethylene, divinylbenzene, Diisopropenylbenzen or Ethyldivinylbenzen exists. 3. The method according to item 1 and 2, characterized in that the organic polymer carrier is used with selectively adjusted degree of crosslinking. 4. The method according to item 1 to 3, characterized in that the polymerization is carried out in suspension, solution and in the gas phase.