DE3538577A1 - Process for the preparation of homopolymers and copolymers of ethylene by means of a Ziegler catalyst system - Google Patents

Abstract

The invention relates to the homopolymerization and in particular copolymerization of ethylene with higher alpha-monoolefins by means of a Ziegler catalyst system comprising (1) a titanium catalyst component and (2) an aluminium catalyst component, where (1) is the product (VI) obtained by (1.1) first combining (1.1.1) an inorganic oxidic support material (I) and (1.1.2) a solution (II) of (IIa) a lower alcohol, (IIb) a titanium trichloride and (IIc) magnesium chloride to form a dispersion (III), and evaporating this to form an intermediate (IV), and (1.2) then combining (1.2.1) the intermediate (IV) from (1.1) and (1.2.2) an aluminium component (V), the resultant product (VI) being the catalyst component (1), characterized in that (1) is the product (VI) obtained from (1.2) on use of an aluminium component (V) comprising (1.2.2.1) a complex compound of a certain ester and a certain aluminium compound and (1.2.2.2) - optionally - a certain free aluminium compound.

Description

The present invention is within the scope of a process for producing homopolymers of ethylene and, in particular, copolymers of ethylene with minor amounts of C ₃ - to C ₈ -, in particular C ₄ - to C ₆ -alpha-monoolefins by polymerization of the monomer or monomers Temperatures of 30 to 200, in particular 50 to 100 ° C, and pressures of 1 to 200, in particular 5 to 60 bar, by means of a Ziegler catalyst system

(1) a titanium-containing catalyst component and

(2) an aluminum-containing catalyst component of the formula

AlR ₃ ,

where it says
R is a C ₁ to C ₁₂ hydrocarbon radical, preferably a C ₁ to C ₁₂ and in particular a C ₂ to C ₈ alkyl group,
with the provisos that (i) the atomic ratio titanium from the catalyst component (1): aluminum from the catalyst component (2) is in the range from 1: 5 to 1: 700, in particular 1:10 to 1: 500, and (ii) as the titanium-containing catalyst component (1), the solid phase product (VI), which has been obtained by

(1.1.) First

(1.1.1) a finely divided, porous, inorganic-oxidic substance (I) which has a particle diameter of 1 to 1,000, in particular 10 to 400 μm, a pore volume of 0.3 to 3, in particular 1 to 2.5 cm ³ / g and a surface area of 100 to 1,000, especially 200 to 400 m ² / g and the formula SiO ₂ · a Al ₂ O ₃ - where a is a number ranging from 0 to 2, particularly 0 to 0.5 - has, and

(1.1.2) a solution (II) as it results when bringing together
(IIa) 100 parts by weight of an alcohol of the formula

R ¹ - OH,

where it says
R ^{1 is} a saturated C ₁ to C ₈ hydrocarbon radical, preferably a saturated C ₁ to C ₆ hydrocarbon radical, and in particular a C ₁ to C ₄ alkyl group,
(IIb) from 0.01 to 6, in particular from 0.04 to 3.5 parts by weight (calculated as titanium) of a titanium trichloride of the formula TiCl ₃ · n AlCl ₃ - wherein n is a number ranging from 0 to 0, 5, preferably 0.2 to 0.4, and in particular 0.31 to 0.35 -, and
(IIc) 0.01 to 4, in particular 0.04 to 2.5 parts by weight (calculated as magnesium) magnesium chloride (MgCl ₂ ),
in contact with one another to form a dispersion (III), with the proviso that the weight ratio of inorganic oxide (I): titanium in the titanium trichloride (IIb) is in the range from 1: 0.01 to 1: 0.2 and the weight ratio inorganic-oxidic substance (I): magnesium in which magnesium chloride (IIc) is in the range from 1: 0.01 to 1: 0.25, the dispersion (III) at a temperature which is below 200, in particular below 160 ° C, and above the melting point of the alcohol used (IIa), evaporates to a dry consistency - formation of a solid-phase intermediate (IV) and

(1.2) then

(1.2.1) the solid-phase intermediate (IV) obtained from stage (1.1.) and

(1.2.2) an aluminum component (V) dissolved in an inert hydrocarbon which, in addition to aluminum, also contains a C ₁ - to C ₁₂ -hydrocarbon residue, preferably a C ₁ - to C ₁₂ -, and in particular a C ₂ - to C ₈ - Contains alkyl group,
brings into contact with one another to form a dispersion, the solid-phase product (VI) resulting as a dispersion being the titanium-containing catalyst component (1).

Polymerization processes of this type are known, in the given context as representative of that described in GB-PS 16 01 418 can.

The type of process mentioned, like other types of process to be placed in parallel, has at its core a catalyst component ( 1 ) which is designed in a special way and contains titanium.

The special configurations of this catalyst component (1) are known made to achieve specific goals, such as the following:

(a) Catalyst systems that increase the yield of polymer deliver assets, namely catalyst systems with an increased Productivity, d. H. Systems where the amount of formed Polymer per unit weight of transition metal of the catalyst component (1) is increased.

(b) catalyst systems through which less or no halogen in the Polymer is introduced; - what can be achieved by

(b ₁ ) the yield according to (a) is increased and / or

(b ₂ ) catalyst components (1) are used which do not contain halogen.

(c) Catalyst systems used in the copolymerization of ethylene with higher alpha monolefins to copolymers with significantly lowered polymer densities.

(d) Catalyst systems that make it possible in the polymerization under the influence of a molecular weight regulator, such as in particular Hydrogen to get by with relatively small amounts of regulator; - what z. B. for the thermodynamics of the process can be of importance.

(e) catalyst systems that are easy and safe to manufacture and good are to be handled; - e.g. B. those that are in (inert) hydrocarbon Have auxiliary media prepared.

(f) Catalyst systems which lead to polymers, in particular copolymers, of ethylene with higher alpha-monoolefins, which have low fractions soluble in n- heptane; - whereby z. B. the tendency of films to stick to these polymers can be suppressed.

(g) catalyst systems that have comparatively small amounts of aluminum containing component (2) need; - whereby z. B. Reduce deposits and corrosion damage on reactor parts to let.

(h) catalyst systems by which the morphological properties the polymers are influenced in a certain way, for example in the sense of a uniform grain size and / or a reduction the fine grain fraction and / or a high bulk density; - what technical control of the polymerization systems, the preparation of the polymers and / or the Processability of the polymers can be important.

(i) Catalyst systems which, when copolymerizing ethylene with higher alpha-monoolefins, are able to incorporate the latter into the copolymer in particularly high relative quantities; - what z. B. for the technical mastery of the polymerization process, in particular when producing copolymers with densities (according to DIN 53 479) of 0.930 g / cm ³ , and / or in the copolymerization using straight-chain C ₄ -, C ₆ - or C ₈ Alpha monoolefins can be of importance as comomers.

According to previous experience, there are many goals several goals that can be achieved by special design of the catalyst system, can only be achieved if you reset other goals.

Under these circumstances, efforts are generally made for such configurations to find, with which one not only achieves the set goals, but also reset other desired goals as little as possible got to.

The task relating to the present invention also lay within this framework has led: A new type of titanium-containing catalyst component (1) to show with the one containing known titanium Catalyst components (1) - with comparable objectives - better Can achieve results, especially what the aforementioned goal (i) concerns that should be achieved as well as possible, at the same time good Also achieve goals (a), (f) and (h).

It has been found that the task can be solved if one in the polymerization process defined at the outset, a Ziegler Catalyst system uses, the titanium-containing catalyst component (1)  is one in which an aluminum component is produced in stage (1.2) (V), which consists of (1.2.2.1) a certain one Complex compound of a specific ester and a specific organic aluminum compound and (1.2.2.2) - if necessary - additionally other specific organic aluminum compound as such.

The present invention accordingly relates to a process for producing homopolymers of ethylene and, in particular, copolymers of ethylene with minor amounts of C ₃ - to C ₈ -, in particular C ₄ - to C ₆ -alpha-monoolefins by polymerization of the monomer (s) Temperatures of 30 to 200, in particular 50 to 100 ° C., and pressures of 1 to 200, in particular 5 to 60 bar, by means of a Ziegler catalyst system

(1) a titanium-containing catalyst component and

(2) an aluminum-containing catalyst component of the formula

AlR ₃ ,

where it says
R represents a C ₁ to C ₁₂ hydrocarbon radical, preferably a C ₁ to C ₁₂ and in particular a C ₂ to C ₈ alkyl group,
with the provisos that (i) the atomic ratio titanium from the catalyst component (1): aluminum from the catalyst component (2) is in the range from 1: 5 to 1: 700, in particular 1:10 to 1: 500, and (ii) as the titanium-containing catalyst component (1), the solid phase product (VI), which has been obtained by

(1.1) first

(1.1.1) a finely divided, porous, inorganic-oxidic substance (I) which has a particle diameter of 1 to 1,000, in particular 10 to 400 μm, a pore volume of 0.3 to 3, in particular 1 to 2.5 cm ³ / g and a surface area of 100 to 1,000, especially 200 to 400 m ² / g and the formula SiO ₂ · a Al ₂ O ₃ - where a is a number ranging from 0 to 2, particularly 0 to 0.5 - has, and

(1.1.2) a solution (II) as it results when bringing together  (IIa) 100 parts by weight of an alcohol of the formula

R ¹ -OH,

where it says
R ^{1 is} a saturated C ₁ to C ₈ hydrocarbon radical, preferably a saturated C ₁ to C ₆ hydrocarbon radical, and in particular a C ₁ to C ₄ alkyl group,
(IIb) from 0.01 to 6, in particular from 0.04 to 3.2 parts by weight (calculated as titanium) of a titanium trichloride of the formula TiCl ₃ · n AlCl ₃ - wherein n is a number ranging from 0 to 0, 5, preferably 0.2 to 0.4 and in particular 0.31 to 0.35 -, and
(IIc) 0.01 to 4, in particular 0.04 to 2.5 parts by weight (calculated as magnesium) magnesium chloride (MgCl ₂ ),
in contact with one another to form a dispersion (III), with the proviso that the weight ratio of inorganic oxide (I): titanium in the titanium trichloride (IIb) is in the range from 1: 0.01 to 1: 0.2 and the weight ratio inorganic-oxidic substance (I): magnesium in which magnesium chloride (IIc) is in the range from 1: 0.01 to 1: 0.25, the dispersion (III) at a temperature which is below 200, in particular below 160 ° C, and above the melting point of the alcohol used (IIa), evaporates to a dry consistency - formation of a solid-phase intermediate (IV) and

(1.2) then

(1.2.1) the solid-phase intermediate (IV) obtained from stage (1.1) and

(1.2.2) an aluminum component (V) dissolved in an inert hydrocarbon which, in addition to aluminum, also contains a C ₁ - to C ₁₂ -hydrocarbon residue, preferably a C ₁ - to C ₁₂ -, and in particular a C ₂ - to C ₈ - Contains alkyl group, brings into contact with each other to form a dispersion, wherein the resulting solid-phase product (VI) as a dispersion is the titanium-containing catalyst component (1).

The inventive method is characterized in that as titanium containing catalyst component (1) is used the solid phase product (VI) obtained from step (1.2) by there as Aluminum component (V) has one that exists

(1.2.2.1) 25 to 100, preferably 35 to 100, and in particular 50 to 100 mol.% Of a complex compound of the empirical formula which is soluble in the inert hydrocarbon where are:
R ² for a C ₁ to C ₁₂ hydrocarbon radical, preferably a C ₁ to C ₈ alkyl group, and in particular a phenyl, tolyl or xylyl group, R ³ for a C ₁ to C ₁₂ , in particular a C ₁ - to C ₄ -alkyl group, R ⁴ and R ⁵ for a C ₁ - to C ₁₂ -hydrocarbon radical, preferably a C ₁ - to C ₁₂ -, in particular a C ₂ - to C ₈ -alkyl group and R ⁶ for a C ₁ to C ₁₂ hydrocarbon radical or chlorine, preferably a C ₁ to C ₁₂ alkyl group or chlorine, and in particular a C ₂ to C ₈ alkyl group or chlorine, and

(1.2.2.2) to 0 to 75, preferably 0 to 65, and in particular 0 to 50 mol% of an aluminum compound of the formula which is soluble in the inert hydrocarbon where are:
R ⁴ and R ⁵ for a C ₁ to C ₁₂ hydrocarbon radical, preferably a C ₁ to C ₁₂ , and in particular a C ₂ to C ₈ alkyl group, and R ⁶ for a C ₁ to C ₁₂ hydrocarbon radical or chlorine, preferably a C ₁ to C ₁₂ alkyl group or chlorine, and in particular a C ₂ to C ₈ alkyl group or chlorine, with the provisos that (i) the sum of the mol% under (1.2.2.1) and (1.2.2.2) is 100 and (ii) the atomic ratio of titanium in the solid-phase intermediate (IV) to aluminum in the aluminum component (V) is in the range from 1: 1 to 1:30, in particular 1: 2 to 1:20, lies.

When using the titanium-containing catalyst component obtained according to the invention (1) The polymerization process as such can be practical all relevant conventional technological designs performed be discontinuous, intermittent or continuous Procedure, be it z. B. as a suspension polymerization process or dry phase polymerization process in stirred or swirled Bed. The technological configurations mentioned - in other words: the technological variants of the polymerization of olefins Ziegler - are well known from literature and practice, so that There is no need to elaborate on them. It should also be noted that the new titanium-containing catalyst component (1) - as corresponding known catalyst components - e.g. B. outside or inside of the polymerization vessel with the catalyst component (2) brought together can be; in the latter case, for example, by spatially separated Entry of the components, which are otherwise in the form of a suspension (catalyst component (1)) or solution (catalyst component (2)) handled can be.

That is for the new titanium-containing catalyst component (1) itself To say the following:

They are manufactured in two stages, the above and below with (1.1) and (1.2) are designated.

In stage (1.1), a fine-particle inorganic-oxidic is brought Substance (I) of the type defined above and a certain one defined above Solution (II) in contact with each other, whereby a dispersion (III) forms that to dry consistency - formation of a solid phase intermediate (IV) - is evaporated. In stage (1.2) the latter is included a solution to a specific one defined above - and for the present one Characteristic invention - brought aluminum component (V) in contact with renewed formation of a dispersion; where as dispersed resulting solid phase product (VI) the new catalyst component (1) is.

You can proceed as follows:  

Level (1.1)

The inorganic-oxidic substance (I) is used as a substance or in an alcohol dispersed (expediently an alcohol as defined under (IIa) and with a solids content of the dispersion of not less than 5% by weight) combined with the solution (II). It is convenient after the union the whole for a period of 5 to 120, in particular 20 to 90 minutes at a temperature of 10 to 160, especially 20 to keep up to 120 ° C and only then evaporate the dispersion (III) formed.

Solution (II) itself can be prepared in the usual manner Manufactures solutions and is therefore not associated with special features. It has proven to be expedient in terms of work technology that solution (II) to be produced by combining a solution from the alcohol (IIa) and the Titanium trihalide (IIb) with a solution of the alcohol (IIa) and the Magnesium chloride (IIc).

As a final measure at stage (1.1), the dispersion (III) to evaporated to a dry consistency, the solid phase intermediate (IV) is obtained. Here you can - in compliance with the above given temperature conditions - proceed as usual Evaporates dispersions gently. This means that in general It is expedient to evaporate under more or less reduced Pressure. As a rule of thumb, consider the temperature / pressure pair should be chosen so that the evaporation process ends after about 1 to 10 hours is. It is also expedient to evaporate under constant protection to ensure the homogeneity of the treated goods; - for what z. B. rotary evaporator have proven. A remaining amount of alcohol an amount bound by complex formation is for the solid phase Intermediate (IV) generally without damage.

Level (1.2)

First, a 1- to 20-, preferably, is prepared in separate batches about 10% by weight suspension of the solid-phase intermediate (IV) and a 5 to 80%, preferably about 10% by weight solution of the aluminum component (V), where as the suspension or solvent inert hydrocarbons, especially relatively low-boiling alkane hydrocarbons, such as hexanes, heptanes or gasolines. Then you unite the suspension and the solution in proportions such that the desired Weight ratio is reached. You will be united in generally add the solution to the suspension while stirring, because  this procedure is more practical than the reverse, which is also possible. At - preferably not to be exceeded - working temperatures from 15 to 60, especially 25 to 40 ° C, is within a period of time from 60 to 300, especially 90 to 180 minutes, the formation of the - Is present as a dispersed - solid phase product (VI). This can be done directly in the form of the dispersion obtained - expediently after washing by digestion - as a titanium-containing catalyst component (1) can be used. It is generally cheaper but to isolate the solid phase product (VI) and only then as a catalyst component (1) insert; - With z. B. the following Weg offers: You separate the product (VI) from the liquid phase by filtration and washes it with pure liquid (such as which had also been used as a suspension or solvent), whereupon you dry it, for example in a vacuum.

If the aluminum component (V) to be used in step (1.2) is not only made from (1.2.2.1) the soluble complex compound defined above but also additionally (1.2.2.2) of the soluble aluminum compound defined above as such, the intermediate (IV) obtained from stage (1.1) can be treated with a common solution of the complex and the aluminum compound or - which is generally more advantageous - successively first with a solution of the complex compound and then with a solution of the aluminum compound .

The new titanium-containing catalyst components (1), i. H. the solid phase Products (VI) can be described in the context of the introduction Polymerization process for producing the polymers mentioned there to be used as is usually the case with the titanium-containing compounds used in the polymerization of olefins according to Ziegler. So far So there are no peculiarities, and it can refer to the literature and Practice well-known uses are referred. - It's just to say that the new catalyst components (1) mainly suitable for producing copolymers of ethylene and that as a copolymerization partner in addition to propene and octene-1, butene-1, 4-methylpentene-1 in particular  and Hexen-1 come into consideration. The regulation of molecular weights the polymers can be carried out in a conventional manner, especially using hydrogen as a regulator.

As for the material side of the new titanium-containing catalyst components (1), the following still has to be said in detail:

The inorganic-oxidic substance (I) to be used in stage (1.1) is in generally an aluminosilicate or - in particular - a silicon dioxide be; it is important that the substance has the required properties and is as dry as possible. Particularly suitable inorganic-oxidic Substances are those that according to the first stage (1) of the GB-PS 15 50 951 method described can be obtained, in particular then, if it is based on hydrogels, which after the in the GB-PS 13 68 711 method described can be obtained.

The alcohols (IIa) to be used can, for. B. be: methanol, ethanol, isopropanol, n- propanol, one of the three isomeric butanols or a hexanol, such as n- hexanol. The alcohols (IIa) can be used in the form of individual individuals and mixtures of two or more individual individuals.

The titanium trichloride (IIb) to be used can be a common one in Ziegler catalyst systems, e.g. B. a reaction product obtained in the reduction of titanium tetrachloride by means of hydrogen, aluminum or organoaluminum compounds. Have to be particularly suitable proved trichlorides of the formula TiCl _3, as obtained in the reduction of titanium tetrachloride with hydrogen and trichlorides of the formula TiCl ₃ · 1/3 AlCl ₃ as obtained in the reduction of titanium tetrachloride with metallic aluminum. The titanium trichlorides can be used in the form of individual individuals and mixtures of two or more individual individuals.

The magnesium compound (IIc) also to be used in stage (1.1) is magnesium chloride (MgCl ₂ ).

The aluminum component (V) to be used in stage (1.2) is in accordance with the invention

(1.2.2.1) 25 to 100, preferably 35 to 100, and in particular 50 to 100 mol% of a complex compound of the empirical formula which is soluble in the inert hydrocarbon where are:
R ² for a C ₁ to C ₁₂ hydrocarbon radical, preferably a C ₁ to C ₈ alkyl group, and in particular a phenyl, tolyl or xylyl group R ³ for a C ₁ to C ₁₂ , in particular a C ₁ to C ₄ alkyl group, R ⁴ and R ⁵ for a C ₁ to C ₁₂ hydrocarbon radical, preferably a C ₁ to C ₁₂ , and in particular a C ₂ to C ₈ alkyl group and R ⁶ for a C ₁ to C ₁₂ hydrocarbon radical or chlorine, preferably a C ₁ to C ₁₂ alkyl group or chlorine, and in particular a C ₂ to C ₈ alkyl group or chlorine, and

(1.2.2.2) to 0 to 75, preferably 0 to 65, and in particular 0 to 50 mol.% Of an aluminum compound of the formula which is soluble in the inert hydrocarbon where are:
R ⁴ and R ⁵ for a C ₁ to C ₁₂ hydrocarbon radical, preferably a C ₁ to C ₁₂ , and in particular a C ₂ to C ₈ alkyl group, and R ⁶ for a C ₁ to C ₁₂ -Hydrocarbon residue or chlorine, preferably a C ₁ - to C ₁₂ -alkyl group or chlorine, and in particular a C ₂ - to C ₈ -alkyl group or chlorine, with the proviso that the sum of the mol% under (1.2.2.1) and (1.2.2.2) is 100.

In the case of the complex compounds are suitable - in each case while observing the above under (1.2.2.1) given order - z. B. the following bodywork partners:

(i) On the part of the esters of an exclusively aliphatic nature Methyl, ethyl, i-propyl and t-butyl acetate; on the part of aromatic esters methyl, ethyl, i-propyl and t-butyl benzoate.  

The esters can be in the form of individual individuals as well Mixtures of two or more individual individuals.

(ii) On the part of the organoaluminum part, especially diethylaluminium chloride as well as triethyl aluminum and triisobutyl aluminum.

These development partners can also be in the form of individual individuals as well as mixtures of two or more individual individuals.

The complex compounds as such are known in nature; a well suitable method for their preparation is e.g. B. given by E.B. Baker and H.H. Sisler in Am.Soc. 75, 4828 (1953).

Suitable aluminum-containing component (2) of the Ziegler catalyst system to be used according to the invention are the relevant customary ones which obey the formula given above; they are so well known from literature and practice that they need not be discussed in more detail. As outstanding representatives which may be mentioned triethylaluminum, triisobutylaluminum and tri-n -butylaluminium.

Finally, it should be noted that the titanium-containing invention Catalyst components (1), i.e. H. the products (VI) sensitive against hydrolytic and oxidative influences. To that extent one should Take the usual precautionary measures (e.g. exclusion of moisture, Inert gas atmosphere).

example

Production of the titanium-containing catalyst component (1)

(1.1) First of all, in a first stage one proceeds by:

(1.1.1) a finely divided, porous, inorganic-oxidic substance (I) which has a participant diameter of 100 to 300 µm, a pore volume of 1.9 cm ³ / g and a surface area of 280 m ² / g and the formula SiO ₂ has, and

(1.1.2) a solution (II) as it results when bringing together
(IIa) 100 parts by weight of methanol,
(IIb) (calculated as titanium), 0.8 parts by weight of a titanium trichloride of the formula TiCl ₃ · n AlCl ₃ - wherein n is the number 0,33 - and
(IIc) 1.5 parts by weight (calculated as magnesium) magnesium chloride (MgCl ₂ ),
brings into contact with one another with stirring for one hour at a temperature of 40 ° C. to form a dispersion (III), with the proviso that the weight ratio of inorganic oxide material (I): titanium in the titanium trichloride (IIb) is 1: 0, 04 and the weight ratio of inorganic-oxidic substance (I): magnesium in the magnesium chloride (IIc) is 1: 0.075, and the dispersion (III) by means of a rotary evaporator, which was brought to an operating pressure of 30 Torr and an operating temperature of 70 ° C is evaporated until dry consistency - formation of a solid-phase intermediate (VI).

This intermediate (IV) contains 2.1% by weight of titanium.

(1.2) Then proceed in a second stage in such a way that

(1.2.1) 100 parts by weight of the solid phase obtained from stage (1.1) Intermediate (IV) and

(1.2.2) an aluminum component (V) dissolved in 280 parts by weight of n- heptane, which consists

(1.2.2.1) in mol.% From a complex compound of the empirical formula (soluble in the n- heptane) where are:
R ² for a phenyl group, R ³ for a methyl group, R ⁴ and R ⁵ for an ethyl group and R ⁶ for chlorine, and

(1.2.2.2) at 50 mol% from an aluminum compound of the formula which is soluble (in the n-heptane) where are:
R ⁴ and R ⁵ for an ethyl group and R ⁶ for chlorine, with stirring for two hours at a temperature of 35 ° C. - with the proviso that the atomic ratio of titanium in the solid-phase intermediate (IV) to aluminum in the aluminum component (V) 1:14 - brings into contact with one another to form a dispersion, the resulting solid-phase product (VI) being the dispersed product being the titanium-containing catalyst component ( 1 ).

The latter is isolated by suction, washed several times with n- heptane and dried; it contains 1.3% by weight of titanium.

Polymerization using the catalyst component ( 1 ) described above

A 1 liter autoclave is filled with 250 ml isobutane, 150 ml butene, 25 mg of the catalyst component (1) and 83 mg of triethyl aluminum as a catalyst component (2) charged (corresponding to an atomic ratio of titanium from the catalyst component (1): aluminum from the catalyst component (2) of 1: 100). Then with stirring and in the - each by regulation kept constant - parameters: ethylene particle pressure 15 bar, hydrogen particle pressure 2 bar, temperature 75 ° C, over a period of 1.5 hours polymerized; then the polymerization is carried out by relaxing the Autoclave broken off.  

Further information on the process product can be found in the table below.

Claims (11)

Process for producing homopolymers of ethylene and copolymers of ethylene with minor amounts of C ₃ - to C ₈ -alpha-monoolefins by polymerization of the monomer (s) at temperatures from 30 to 200 ° C and pressures from 1 to 200 bar a Ziegler catalyst system (1) a titanium component and (2) an aluminum-containing catalyst component of the formula AlR ₃ , in which
R for a C ₁ to C ₁₂ hydrocarbon residue,
with the provisos that (i) the atomic ratio titanium from the catalyst component (1): aluminum from the catalyst component (2) is in the range from 1: 5 to 1: 700 and (ii) the titanium-containing catalyst component ( 1 ) is used solid phase product (VI) which has been obtained by (1.1) first (1.1.1) a finely divided, porous, inorganic-oxidic substance (I), which has a particle diameter of 1 to 1,000 µm, a pore volume of 0.3 to 3 cm ³ / g and a surface area of 100 to 1,000 m ² / g and has the formula SiO ₂ · a Al ₂ O ₃ - where a is a number ranging from 0 to 2 - has, and (1.1.2) a solution (II) as it results when bringing together
(IIa) 100 parts by weight of an alcohol of the formula R ¹ - OH, which is
R ¹ for a saturated C ₁ to C ₈ hydrocarbon radical,
(IIb) (calculated as titanium) 0.01 to 6 parts by weight of a titanium trichloride of the formula TiCl ₃ · n AlCl ₃ - wherein n is a number ranging from 0 to 0.5, and
(IIc) 0.01 to 4 parts by weight (calculated as magnesium) magnesium chloride (MgCl ₂ ),
in contact with one another to form a dispersion (III), with the proviso that the weight ratio of inorganic oxide (I): titanium in the titanium trichloride (IIb) is in the range from 1: 0.01 to 1: 0.2 and the weight ratio inorganic-oxidic substance (I): magnesium in which magnesium chloride (IIc) is in the range from 1: 0.01 to 1: 0.25, the dispersion (III) at a temperature which is below 200 ° C. and above that Melting point of the alcohol used (IIa) is, until dry consistency - formation of a solid-phase intermediate (IV) - evaporated and (1.2) then (1.2.1.) The solid-phase intermediate (IV) obtained from stage (1.1.) and (1.2.2.) An aluminum component (V) dissolved in an inert hydrocarbon, which contains not only aluminum but also a C ₁ to C ₁₂ hydrocarbon residue,
brings into contact with one another to form a dispersion, the resulting solid-phase product (VI) which is thereby dispersed being the titanium-containing catalyst component (1),
characterized in that the titanium-containing catalyst component (1) is the solid-phase product (VI) which has been obtained from stage (1.2.) by using there as aluminum component (V) one which exists (1.2.2.1) to 25 to 100 mol.% Of a complex compound of the empirical formula which is soluble in the inert hydrocarbon where are:
R ² for a C ₁ to C ₁₂ hydrocarbon residue
R ^{3 represents} a C ₁ to C ₁₂ alkyl group,
R ⁴ as well
R ⁵ for a C ₁ to C ₁₂ hydrocarbon residue and
R ⁶ for a C ₁ to C ₁₂ hydrocarbon residue or chlorine
such as (1.2.2.2.) 0 to 75 mol.% Of an aluminum compound of the formula which is soluble in the inert hydrocarbon where are:
R ⁴ as well
R ⁵ for a C ₁ to C ₁₂ hydrocarbon radical and
R ⁶ for a C ₁ to C ₁₂ hydrocarbon residue or chlorine,
with the provisos that (i) the sum of the mol% under (1.2.2.1) and (1.2.2.2.) is 100 and (ii) the atomic ratio of titanium in the solid-phase intermediate (IV) to aluminum in the aluminum component (V ) is in the range of 1: 1 to 1:30.