DE2946562C2 - Solid titanium and / or vanadium-containing catalyst components and their use in combination with an organometallic compound as a catalyst system for the polymerization of ethylene - Google Patents

Description

in which R ³ and R ^{4 can be the} same or different and each represent an alkyl radical having 1 to 20 carbon atoms and η is a number from 0 to 3, ρ and q each represent a number from more than 0 to 1, pure number is in the range from 0 to 0.6 and the sum of ρ +? + r = 2, with (2) a titanium and / or vanadium compound from the group of alkoxy chlorides of tetravalent titanium with at least 3 chlorine atoms, titanium tetrachloride and vanadium tetrachloride, at a temperature of -30 to 100 ^° C., in an aliphatic, alicyclic one or aromatic hydrocarbon as the inert reaction medium, using 0.2 to 10 moles of the organomagnesium compound (1) per mole of the titanium and / or vanadium compound (2), isolating the solid catalyst component formed, which is insoluble in the hydrocarbon medium, and washing it with inert hydrocarbons, thereby marked that they are under use

25 of an organomagnesium compound (1) of the formula in which 5 is a number from more than 0 to less than 0.1.

2. Use of the solid titanium and / or vanadium-containing catalyst components (A) according to Claim 1 in combination with an organometallic compound (B) from the group of organoaluminum compounds the formula

in which R ^{5 is} an alkyl radical having 1 to 20 carbon atoms, Y is a hydrogen or chlorine atom, an alkoxy radical having 1 to 20 carbon atoms, a phenoxy radical or a siloxy radical and m is a number from 2 to 3, or the organomagnesium complexes of the formula

40} i

in which M is a metal atom from the group consisting of Al, B, Be and Zn, R ⁶ and R ⁷ , which can be identical or different, each represent an alkyl radical with 1 to 10 carbon atoms, a cyclohexyl or a phenyl radical, d, e, f and Λ each stand for a number above 0, which = 1 to 8 and 2d + ae = f + h, where α is the valence of M, and optionally (C) a chlorinated, brominated or iodinated hydrocarbon with 1 up to 15 carbon atoms, as a catalyst system for the polymerization of ethylene,

From JP-PS 2 33 148 (K. Ziegler) it is known that polyethylene is used under low pressure a catalyst containing an organomagnesium compound and a transition metal compound can be. The organomagnesium compound, however, has the disadvantage that it is used as such in the as Medium for the catalyst production and the polymerization of ethylene used inert hydrocarbons

55 is insoluble in hydrogen, so that catalysts with high activity could not be prepared.

From JP-OS 7 20 40 959 is also known that when using the organomagnesium compound in a certain form catalysts with increased activity can be obtained. To these organomagnesium compounds include, for example, complexes of organomagnesium halides; H. so-called Grignard compounds with an ether and organomagnesium alkoxides. The catalysts that make these organomagnesium

contain bonds, have a relatively high activity per transition metal atom, but for catalysts which make the measure of catalyst removal in a process for the production of polyethylene completely superfluous, the amount of halogen atoms remaining in the polymers produced is still high.
Solid titanium and / or vanadium-containing catalyst components (A), prepared by reacting (1)

65 of an organomagnesium compound of the formula ## STR3 ## which is soluble in the hydrocarbon medium

MgRiRjXZ ₅

in which R ^{1 is} an alkyl group with 2 to 3 carbon atoms, R ^{2 is} an alkyl group with 4 to 20 carbon atoms and the difference in the number of carbon atoms between R ¹ and R ^{2 is} at least 2, X is an alkoxy group with 1 to 20 carbon atoms, a Is a siloxy group or a C ₂ H ₅ S group, Z is an organometallic compound from the group of lithium alkyls, zinc and beryllium dialkyls, boron trialkyls, aer silane tetraalkyls, trialkylsilanes and organoaluminum compounds of the formula

AIRj (ORV _n

in which R ³ and R ^{4 can be the} same or different and each represent an alkyl radical having 1 to 20 carbon atoms and η is a number from 0 to 3, ρ and? each stand for a number from more than 0 to 1, is a pure number in the range from 0 to 0.6 and the sum of ρ + ? + r = 2, with (2) a titanium and / or vanadium compound from the group of alkoxy chlorides of tetravalent titanium with at least 3 chlorine atoms, titanium tetrachloride and vanadium tetrachloride, at a temperature of -30 to 100 ^° C., in an aliphatic, acyclic one or aromatic hydrocarbon as the inert reaction medium, using 0.2 to 10 moles of the organomagnesium compound (1) per mole of the titanium and / or vanadium compound (2) and isolation of the solid catalyst component formed, which is insoluble in the hydrocarbon medium, are already known ( See DE-OS 25 23 167, 25 19 071 and 25 23 165 as well as the corresponding US-PS 39 89 878, 40 04071 and 40 27 087 and the report of JP-OS 5 21 27 490 in CPI-Profile Booklet 1978). It is also already known from these publications to use these catalyst components (A) in combination with an organometallic compound (B) as a catalyst system for the polymerization of ethylene. Although these catalyst systems have a very high activity, they leave something to be desired with regard to the bulk density of the polyethylene obtained.

The object of the invention was therefore to add solid titanium and / or vanadium-containing catalyst components (A) elaborate which when used in combination with an organometallic compound (B) for ethylene polymerization Polymers with increased bulk density result.

The invention thus relates to the solid titanium and / or vanadium-containing catalyst components (A) and their use in combination with an organometallic compound (B) as a catalyst system for the polymerization of ethylene as described in the claims.

One of the characteristic features of the invention is a very high catalytic efficiency. on The reason for this feature is the amount of catalyst residue, e.g. B. the transition metals and halogen atoms, the remain in the polymers produced, low. Steps to remove catalyst residues are therefore necessary not mandatory.

Another characteristic feature of the invention is that the polymers produced are excellent Have particle properties, d. H. have a uniform particle size and not a coarse one Contain particles which cause disturbances in the continuous polymerization, as well as a high one Have bulk weight.

Another characteristic feature of the invention is that the molecular weight distribution the polymers can easily be adjusted within wide limits.

The polymers have high molecular weights, high rigidity and rigidity, and a narrow molecular weight distribution and high impact strength.

Preferred embodiments of the invention are described below.

The organic magnesium compound (1) used for the preparation of the solid catalyst component of the present invention (A) used has the general formula

Mg RjR ² , X, · Z ₁

f in which R ¹ , R ² , X, Z, p, q, r and s have the meanings already mentioned.

% In this formula, R ^{1 is} an alkyl radical with 2 to 3 carbon atoms. Examples of such alkyl radicals are the ethyl radical,

f. to mention the propyl radical and the isopropyl radical. Of these, the ethyl radical is preferred. R ² in the above

Formula is an ethyl radical with 4 to 20 carbon atoms, for example a butyl radical, pentyl radical, hexyl radical, heptyl radical,

;;. Octyl radical, nonyl radical, decyl radical, dodecyl radical or hexadecyl radical. Of these radicals, the butyl radical is the

! ί Pentyl radical and the hexyl radical are preferred. The difference of few? 2 is between R and R in the C number

iS an important factor to break down the organomagnesium compound (I) in inert hydrocarbons in high concentrations

to dissolve fe concentrations.

£ · The electronegative groups X are an alkoxy group with 1 to 20 carbon atoms, a siloxy group or a

[f C ₂ H _S S group.

f The organometallic compounds Z are aluminum trialkyls, alkylaluminum alkoxides, trialkoxyalu-

• minium, beryllium dialkyls, boron trialkyls, zinc dialkyls, silane tetralkyls, trialkylsilanes and lithium alkyls. Before-

k Among these organometallic compounds, organoaluminum compounds are the general ones

^s formula

AIR ³ (ORV "

in which R ³ and R ^{4 can be} identical or different and each stand for an alkyl radical having 1 to 20 carbon atoms and η is a number from 0 to 3. Aluminum trialkyls and alkylaluminum alkoxides are particularly preferred

and trialkoxy aluminum.
η and α are numbers from more than zero to!, and λ is a number in the range from 0 to 0.6, the sum of

ρ + q + r = 2. If it is in the range from 0 to 0.6, the catalytic activity is increased; r is an important factor in order to achieve a narrow molecular weight distribution of the polymer. When it is in the range from 0.2 to 0.6, the effect of imparting a narrow molecular weight distribution to the formed polymer with high catalytic activity can be achieved. The value of s is above 0 and below 0.1, with a range of 0.09 to 0.02 being preferred in order to lower the solution viscosity of the organomagnesium compound (1), thereby making it easy to handle, and to make it high in activity achieve.

These organomagnesium compounds can be prepared by forming a reaction product between an organohalide of the formula R ¹ W, ^{wherein R 1 is} as defined above and W is a halogen atom, and magnesium metal; h a so-called. Grignard compound, with an organolithium compound of

Fornvsl R ² Li, in which R ^{2 has} the meaning given above, reacted or an equimolar mixture of an organohalide of the formula R ¹ W and an organohalide of the formula R ² W, in which R ¹ and R ^{2 have} the meanings given above and W is a halogen atom, is reacted with magnesium metal by the method described in US Pat. No. 4,127,507.
An electronegative group X is introduced by implementing an organomagnesium compound

15 using the formula

MgRjR ² ,

in which R ¹ , R ² , ρ and q have the meanings given above, with a reagent selected from the alcohol,

Silanols, siloxanes and ethyl mercaptan. Examples of suitable reagents are ethanol, Propanol, butanol, hexanol, octanol, trimethylsilanol, triphenylsilanol, dimethyldihydrodisiloxane, cyclic Methylhydrotetrasiloxane, methylhydropolysiloxane and ethyl mercaptan.

A suitable method for introducing the electronegative group X is described by G. E. Coats and K. Wade in "Organometal Compounds", Vol. 1, published by Methuen & Co., Ltd. described.

Suitable titanium and / or vanadium compounds (2) for the preparation of the solid catalyst component (A) according to the invention are ethoxy titanium trichloride, propoxy titanium trichloride, butoxy titanium trichloride, titanium tetrachloride and vanadium tetrachloride. Of these compounds, titanium tetrachloride and vanadium tetrachloride are preferred.
The reaction of the organomagnesium compound (1) with the titanium and / or vanadium compound (2) is carried out in an inert reaction medium such as an aliphatic hydrocarbon such as hexane or heptane or an aromatic hydrocarbon such as benzene, toluene or xylene, or an alicyclic hydrocarbon such as Cyclohexane or methylcyclohexane, at a temperature of -30 to 100 ^° C., preferably -20 to 50 ^° C., carried out. To achieve high activity, the ratio of the two components in the reaction is in the range of 0.2 to 10 moles of organomagnesium compound (1) per mole of titanium and / or vanadium compounds

35 binding (2).

The composition and structure of the solid catalyst component (A) according to the invention, which are used in the reaction described above may be obtained depending on factors such as the selected Starting materials and the reaction conditions used can be varied within wide limits. In general, the molar ratio of Mg / (Ti and / or V) in the solid catalyst component (A) is in the range from 0.2 to 10. A molar ratio of Mg / (Ti and / or V) in the range from 0.5 to 5 is preferred.

The catalyst component (A) according to the invention obtained in this way has a very high specificity Surface on. Measurement by the BET method gives a specific surface area in the range from 50 to

400 m ² / g.

The solid catalyst component (A) according to the invention, in combination with an OrganometaHver-

45 bond (B) represents a superior catalyst system for the polymerization of ethylene. As the organometallic compound (B), there are organoaluminum compounds of the formula

₃ - ",

so suitable in which R ^{5 is} an alkyl radical with 1 to 20 carbon atoms, Y is a hydrogen atom, a halogen atom, an alkoxy radical with 1 to 20 carbon atoms, a phenoxy radical, a substituted phenoxy radical or a siloxy radical and m is a number from 2 to 3 is.
Examples of suitable organoaluminum compounds are

55 aluminum triethyl,

Tri-n-propylaluminum, Aluminum triisopropyl, Tri-n-butyte aluminum,

Aluminum isobutyl, 60 aluminum trihexyl,

Aluminum trioctyl, Aluminum tridecyl, Aluminum tridodecyl,

Aluminum trihexadecyl, 65 diethyl aluminum hydride,

Diisobutyl aluminum hydride, Diethyl aluminum ethoxide, Diisobutylaluminium ethoxide, Dioctyl aluminum butoxide, Diisobutyl aluminum octyloxide, Diethyl aluminum chloride, Diisobutyl aluminum chloride, Dirnethylhydrosiloxyaluminiurndimethy !, Ethylmethylhydrosiloxyaluminum diethyl and Ethyldimethyisiloxyaluminum diethyl. Organomagnesium complexes suitable as organometallic compound (B) are those of the formula

in which M is a metal atom from the group consisting of aluminum, boron, beryllium and zinc, R ⁶ and R ⁷ , which can be identical or different, each represent an alkyl radical with 1 to 10 carbon atoms and a cyclohexyl or phenyl radical, d, e, f and ft each stand for a number above 0, which = 1 to 8 and is 2d + ae = / + h, where α is the valence of M.

Examples of the alkyl radicals R 'and R ⁷ are methyl radicals, ethyl radicals, propyl radicals, butyl radicals, amyl radicals, hexyl radicals and decyl radicals. Of the metal atoms, aluminum and zinc are preferred.

The organomagnesium complexes can be readily prepared by methods described in U.S. Patents 40 04 071 (corresponds to DE-OS 25 19 071), 40 27 089 (corresponds to DE-OS 25 23 165), 39 89 878 (corresponds to DE-OS 25 23 167) and 41 20 883, and in the references "Ann." 605 (1957) 93-97, "J. Chem. Soc. «1964, 2483-2485, "Chemical Communication" 1966, 559, "J. Org. Chem. «34 (1969) 1116 and in the report of the JP 5 21 27 490 are described in CPI-Profile Booklet 1978.

A combination of the organometallic compounds (B) with the solid catalyst component (A) according to the invention results in an extremely active catalyst system. In particular, aluminum trialkyls and dialkyl aluminum hydrides are preferred as the organometallic compound (B) because they give the highest activity. The activity If an electronegative group, for which Y stands, is introduced into the aluminum trialkyl or the Dialkylaluminum hydride to fall off, but the organoaluminum compounds which contain the group Y an exceptional behavior during the polymerization, in which they produce high-quality polymers with high Form activity. For example, the introduction of an alkoxy group makes the adjustment of the molecular weight the polymers made easy. Because the presence of halogen atoms in the polymerization system and is undesirable in the formed polymers, an alkoxy group and a siloxy group are used as Group Y preferred.

The solid catalyst component (A) and the organometallic component (B) can under the polymerization conditions added to the polymerization system or combined before the polymerization. The ratio of these two components is preferably in the range from 1 to 3000 mmol of the organometallic Compound (B) per gram of the solid catalyst component (A).

The chlorinated, brominated or iodinated hydrocarbons (C) that are used in combination with the solid catalyst component (A) can be used together with the organometallic compound (B) to form polymers with a wide molecular weight distribution with high catalytic activity are saturated or unsaturated chlorinated, brominated or iodinated hydrocarbons with 1 to 15 carbon atoms. Preferably the number of Cl, Br or I atoms of the halogenated hydrocarbons is at most twice as high as the number of carbon atoms of the halogenated hydrocarbons. Examples of suitable halogenated hydrocarbons are dichloromelhan, 1,2-dichloroethane, 1,1,2-trichloroethane, 1,1,2,2-tetrachloroethane, 1,2-dichloropropane, 1,3-dichloropropane, 1,2,3-trichloropropane, n-butyl chloride, isobutyl chloride, 1,4-dichlorobutane, 2,3-dichlorobutane, 1,2,3,4-tetrachlorobutane, n-hexyl chloride, 1,6-dichlorohexane, 1,2-dichloroctane, dibromomethane, 1,2-dibromoethane, n-butyl bromide, chlorobenzene, phenethyl chloride, allyl chloride, bromobenzene and ethyl iodide.

The combination of these halogenated hydrocarbons (C) with the solid catalyst component according to the invention (A) and the organometallic compound (B) can under the reaction conditions during the The course of the polymerization or before the polymerization can be carried out. The polymerization can also using the reaction product obtained by reacting the solid catalyst (A) with the halogenated hydrocarbon (C) and isolation of the solid formed has been obtained, and the Halogenate organometallic compound (B) with or without further addition of the same or a different one Hydrocarbon (C) are carried out. The ratio of these catalyst components is preferable in the range of 1 mmole to 3,000 mmole of the organometallic compound (B) per gram of the solid catalyst component (A) and Ibis 3000 mmoles of the halogenated hydrocarbon (C) per gram of the solid catalyst component (A), and the molar ratio of the halogenated hydrocarbon (C) to the organoaluminum compound (A) is in the range from 0.01 to 100, in particular in the range from 0.1 to 20.

The polymerization can be carried out as a customary suspension, solution and gas phase polymerization. In suspension and solution polymerization, the catalyst components are used together with a polymerization medium, e.g. B. an aliphatic hydrocarbon such as hexane or heptane, an aromatic hydrocarbon such as benzene, toluene or xylene, or an alicyclic hydrocarbon such as cyclohexane or methylcyclohexane, introduced into the reactor, whereupon the ethylene under a pressure of 1 to 196 bar in a added inert atmosphere and at a temperature of 10 to 300 ⁰ C is polymerized.

In the gas phase polymerization may be an ethylene pressure of 1 to 49 bar at a temperature of 10 to 120 ⁰ C in the fluidized bed, the moving bed or while mixing with a stirrer, in order to achieve better contact between the ethylene and the catalyst, are worked.

The polymerization can be carried out in one stage in one polymerization zone or in several stages in several polymerization zones be performed.

When carrying out the multistage polymerization in at least two polymerization zones in which Various polymerization conditions can be seen using the catalyst component (A) according to the invention in combination with an organometallic compound (B) polymers with much wider Molecular weight distribution can be produced.

Hydrogen and halogenated hydrocarbons can also be used to adjust the molecular weight of the polymers or organometallic compounds which can bring about chain transfer can be added.

The following examples, which describe preferred embodiments, further illustrate the principle and practice of the invention. In these examples and in the comparative experiments, mean

Mw is the weight average molecular weight, determined according to the following equation:

[η] = 6.8 X 10 " ⁴ Wh- ⁰ "

(see "Journal of Polymer Science" 36 [1957] 91);

MwIMn is the index of the molecular weight distribution, measured by gel permeation chromatography,

and the term "catalytic efficiency" indicates the amount of polymer per gram of catalyst per Hour reaction time per 0.980665 bar ethylene pressure has been formed.

Comparative experiment A 25 I. Synthesis of the organomagnesium compound (1)

Into a 1-1 flask purged with nitrogen was placed 6.1 g (250 mmol) of magnesium powder, followed by adding 1/10 of 300 ml of an n-heptane solution containing 250 mmol of CjHsBr. During the stirring at an internal temperature of the flask of 90 ⁰ C, the reaction started after about 10 minutes. The reaction mixture solution was added to the rest of the n-heptane solution for a period of 2 hours with stirring while the inner temperature of the flask was kept at 9O ⁰ C, which was followed by the reaction for an additional hour at 9O ⁰ C. Then, 200 ml of a heptane solution containing 1 mol / l of n-butyllithium was added to the reaction solution. The mixture was refluxed for 6 hours. After the completion of the reaction, the reaction solution was allowed to stand and the supernatant liquid was taken out. The analysis for Mg and Br showed that this liquid contained 0.37 mol of Mg and less than 0.01 mol of Br per liter. The liquid was then reacted with iodine in an amount of 2 equivalents of iodine per magnesium atom. The alkyl iodide formed had a C ₂ HjJZn-C ₄ H ₉ J-MoIVe ^ aHnJs of 1.05 as determined by gas chromatography. The organomagnesium compound obtained had the formula C ₂ H ₃ Mg nC ₄ H ₉ .

40 II. Synthesis of the solid catalyst component (A)

The oxygen and moisture that were present in a 500 ml kebab fitted with two dropping funnels were stripped off with dry nitrogen. 160 ml of n-heptane were then added to the flask and the mixture was cooled to -5 ° C. Then, 80 ml of a heptane solution containing 40 mmol of the C ₂ H ₅ Mg · nC ₄ H ₉ obtained as described above and 80 ml of a heptane solution containing 60 mmol of titanium tetrachloride were precisely measured and separately placed in the dropping funnels. The two components were simultaneously added to the flask at -5 ° C over a period of 2 hours with stirring, after which the aging reaction was continued at 5 ° C. The catalyst component (A) formed in this way, which was insoluble in the hydrocarbon medium, was isolated, washed with n-heptane and dried.

ΪΙΙ. Polymerization

5 mg of the solid catalyst component were placed in an evacuated 1.5 l autoclave flushed with nitrogen (A) and 0.4 mmol of aluminum triisobutyl with 0.81 of dehydrated and deaerated n-heptane.

While the internal temperature of the autoclave was kept at 85 ^° C., hydrogen was injected up to a manometer pressure of 1.57 bar. Ethylene was then pressed in up to a total manometer pressure of 3.92 bar. While the total pressure of 3.9.2 bar was maintained by forcing in ethylene, the polymerization was carried out for 1 hour, 134 g of polymer being formed. The polymer had a weight average molecular weight of 125,000, an Mw / Mn value of 10.3 and a shake weight

60 of 0.39 g / cm ³ and had been formed with a catalytic efficiency of 11200.

Examples 1 to 9

Solid catalyst components (A) were obtained by reacting the organomagnesium compounds mentioned in Table I. with the titanium and / or vanadium compounds mentioned in Table I, which contained at least 1 halogen atom, under the reaction conditions mentioned in Table I to the in Comparative Experiment A described way. Using these solid catalyst components (A) and aluminum triisobutyl ethylene was poly-

merized. The results are shown in Table I.

Examples 10 to 18

Using the catalyst component (A) according to Example 1, ethylene was polymerized under the polymerization conditions mentioned in Comparative Experiment A, but with those mentioned in Table II
Organometallic compounds (B) and halogenated hydrocarbons (C) instead of aluminum triisobutyl
were used. The results are given in Table II.

3-a

N trt

«Y S N to

Il

OB Z

"I.

0.4

oo.

0.94

0.37

W-)

, 72

O \ (N

O

(N IT)

r »

0.43

5.3

, 92

O - - - * - «

(N -

O <N

(N

O (N

¹ ^ I

WHERE

O 1 ^)

_7 U H

H> H

Table II Organoaluminum compound (B) Halogenated hydrocarbon (C) More catalytic
Efficiency Mw MwIMn example (mmol) (mmol) (10 ^ä ) Al (C ₂ Hj) ₃ 0.2 ClCH ₂ CH ₂ Cl 0.4 8900 1.83 19.6 10 Al (C ₂ Hs) ₃ 0.2 BrCH ₂ CH ₂ Br 0.1 9200 2.07 18.9 11th AKi-C ₄ H ₉ J ₃ 0.4 CH ₂ Cl ₂ 0.4 9000 2.15 20.3 12th AKi-C ₄ Hj) ₂ H 0.4 - 13000 1.35 9.6 13th Al (n-CgH 17) 3 0.8 Ch ₃ CH ₂ CHCICH ₂ CI 0.2 9300 1.64 17.6 14th AKC ₂ Hs) ₂₁₆ (OC ₂ H ₅ ) O _-4 1.0 - 6900 1.73 13.2 15th Al (C ₂ Hs) ₂ ^ OSi-H-CH ₃ -C ₂ H ₅ ) O.! 1.0 - 6700 1.91 12.8 16 AlMgiCjH ^ in-C.H, ^ 0.8 CH ₂ CKCS 0.8 8900 1.94 18.2 17th AlMg ₆ (C ₂ Hs) ₃ - (UC ₄ H,) !, 1.5 - 11000 1.10 12.3 18th

VTi; .-- ,. ■;. *.-R. · ■ '■■■■: «

Claims (1)

Patent claims: 1. Solid titanium and / or vanadium-containing catalyst component (A), prepared by reacting (1) an organomagnesium compound of the formula which is soluble in the hydrocarbon medium in which R ^{1 is} an alkyl group with 2 to 3 carbon atoms, R ^{2 is} an alkyl group with 4 to 20 carbon atoms and the difference in the number of carbon atoms between R ¹ and R ^{2 is} at least 2, X is an alkoxy group with 1 to 20 carbon atoms, a Is a siloxy group or a C ₂ H _S S group, Z is an organometallic compound from the group of lithium alkyls, zinc and beryllium dialkyls, boron trialkyls, silane tetraalkyls, trialkylsilanes and organoaluminum compounds of the formula AlRj (OR ⁴ )., -,