NO168649B - PROCEDURE FOR PREPARING A CATALYST FOR USE BY POLYMERIZATION OF ALFA OLEFINES - Google Patents

Abstract

Catalyst for polymerization. of α-olefins. It comprises the reaction product of (1) the reaction product of a polymeric transition metal oxide-alkoxide and a reducing metal having a higher oxidation potential than the transition metal with (2) a halide activator. The preparation of the catalyst is described. It is optionally used in conjunction with an organometallic cocatalyst.

Description

This invention relates to a method for the production of a catalyst for use in the polymerization of α-olefins.

Polyethylene produced by dissolution or slurry processes at low pressures or in autoclave reactors or tube reactors at high pressures has been the subject of commercial production for many years.

In recent times, interest has centered on polyethylene resins characterized by linearity and short branched chains, which are obtained from alkene comonomers, and which exhibit narrow molecular weight distribution, improved strength properties, higher melt viscosity, higher softening point, improved resistance to environmentally induced stress cracking ESCR (Environmental Stress Crack Resistance)

and improved low-temperature brittleness. These and related properties bring advantages for the user in terms of such applications as blown film, coverings for wires and cables, cast films, coextrusion, injection molding and rotational molding.

The linear olefin polymers have generally been prepared using catalysts of the general type described by Ziegler and thus comprise a compound of a transition metal, usually a titanium halide mixed with an organometallic compound such as alkylaluminium. The transition metal component may be activated by reaction with a halide activator, such as an alkyl aluminum halide. Among the improved catalysts of this type are those which include a magnesium component, usually with interaction between magnesium or a magnesium compound and the transition metal component or the organometallic component, e.g. in that they are painted together, have entered into a chemical reaction with each other or are associated with each other.

There is also interest in producing resins from

from medium to high density and with modified properties using coordination catalysts of this type. In particular, resins with a wider molecular weight distribution and a higher melt index are sought after.

The invention now provides a method for producing a catalyst for use

share - optionally together with a co-catalyst - by polymerization of α-olefins, which method is characterized by that

(a) a transition metal alkoxide is partially hydrolyzed to a polymeric transition metal alkoxide, (b) the polymeric transition metal alkoxide is reacted with a reducing metal of higher oxidation potential than the transition metal, and (c) the product of step (b) is activated with a halide activator.

The polymeric transition metal oxide-alkoxide can be prepared separately by controlled hydrolysis of the alkoxide, or the polymeric oxoalkoxide can be formed through a reaction in situ, e.g. by hydrolysis in a reaction medium containing the reducing metal. For example, titanium or zirconium tetrabutoxide can be reacted with metallic magnesium in a hydrocarbon solvent and in the presence of a controlled water donor, preferably a hydrated metal salt, such as magnesium halide hexahydrate.

Transition metal alkoxides, especially titanium alkoxides, are known for their binding properties in organic solvents, and for their sensitivity to hydrolysis. It is stated in the literature that the hydrolysis reaction which proceeds from the oligomeric, usually trimeric titanium alkoxides, results in polymeric titanium oxide alkoxides. The reaction is usually expressed as:

Condensation reactions can likewise, especially at elevated temperatures, give structures containing bridges between primary metal and oxygen, such as:

which in turn participate in or form precursors for the hydrolysis reaction.

These polymeric titanium alkoxides or oxoalkoxides (which are sometimes also referred to as u-oxoalkoxides) can be represented by the series tTi3 (x+u °4X (°R4 (x+3) ^ ' where X = 0, 1, 2, 3..., as the structure reflects the tendency of the metal to extend its coordination beyond its primary valence, and likewise the ability of the alkoxide to form a bridge between two or more metal atoms. Whatever form the alkoxide is given for visualization, in practice it is sufficient to recognize that the alkoxide oligomers on controlled hydrolysis forms a series of polymeric oxide-alkoxides that extend from the dimer through cyclic forms to straight-chain polymers of chain length that can increase almost to infinity. More complete hydrolysis, on the other hand, leads to the precipitation of insoluble products, which on complete hydrolysis leads to orthotitanic acid.

To make the description more clear, these materials will be termed polymeric oxide-alkoxides of the respective transition metals, and they thus represent the partial hydrolysis products. The hydrolysis reaction can be carried out separately and the products isolated and stored for later use, but this is inappropriate, especially in view of the possibility of further hydrolysis. Accordingly, it is preferred in practice to form these materials in the reaction medium. Experience shows that the same hydrolysis reaction takes place in situ.

The hydrolysis reaction itself can be regulated directly through the amount of water added to the transition metal alkoxide and the rate of addition. Water must be added gradually. Adding the water in larger portions does not lead to the desired reaction, rather it leads to excessive hydrolysis, with precipitation of insoluble substances. Dropwise addition is expedient and likewise the use of reaction water, but it has proven more appropriate to provide the water as crystallization water, sometimes referred to as cationic water, anionic water, net structure water or zeolitic water. Thus, ordinary hydrated metal salts are usually used when the presence of the salts in itself does not have an adverse effect on the system. It seems that the binding in the coordinated ring of water in a hydrated salt is suitable for the regulated release and/or availability of water or water-related components to the system, tailored to the need for the origin of, participation in or regulation of the reaction .

As mentioned above, the total amount used has a direct impact on the form of polymeric oxide-alkoxide that is formed and is thus selected in relation to the catalytic performance. (It is believed, with caveats, that the stereoconfiguration of the partially hydrolyzed transition metal alkoxide determines or partially contributes to the nature or outcome of the activated catalyst component's catalytic action

nothing. )

It has been found that it is usually sufficient

to use as little as 0.5 mol of water per moles of transition metal. Amounts of up to 1.5 mol are suitable, as larger amounts, up to 2.0 mol, can also be used provided that precipitation of hydrolysis products from the hydrocarbon dissolution medium can be avoided. This can in principle be achieved by reducing the addition rate and stopping the addition at the first sign of precipitation. Although it is assumed that the reaction is essentially equimolar, it may be appropriate to use a certain excess of water in some cases, as is usually done.

It will be understood that the stereoisomeric form, chain length, etc. of the hydrolysis product may change somewhat with the elevated temperature required for the subsequent reaction with the reducing metal, and processes carried out in situ will likewise affect the equilibria through mass- the impact effect. Likewise, the simultaneous formation of alkanol can affect the equilibria, reaction rates, etc.

The hydrolysis reaction takes place at ambient pressure and temperature and does not require any special conditions. A hydrocarbon solvent can be used, but this is not necessary. Bare and bare contact between the materials is sufficient for a period of time that is usually from 10 - 30 minutes to 2 hours. The material obtained is stable

under normal storage conditions, and it can be worked up to a suitable concentration level as desired, simply by dilution with a hydrocarbon solvent.

The polymeric transition metal oxide-alkoxides are reacted

with a reducing metal with an oxidation potential higher than that of the transition metal. Preferably, a polymeric titanium oxide-alkoxide is used together with magnesium, calcium, potassium, aluminum or zinc as the reducing metal. Combinations of transition metal alkoxide, reducing metal

and hydrated metal salt is appropriately chosen in consideration of the electropotentials in order to keep the occurrence of side reactions to a minimum, as is known in the art. Generally, moreover, in order to ensure preferred activity levels for olefin polymerization, magnesium will be added to the system by appropriate choice of reducing metal/hydrated metal salt.

In the preferred embodiment (which will be referred to in the following text for the sake of overview) titanium tetra-n-butoxide (TBT) is reacted with magnesium turnings and hydrated metal salt, preferably magnesium chloride hexahydrate,

at a temperature in the range from 50 to 150 oC, in a reaction vessel under autogenous pressure. TBT can form the reaction medium, or a hydrocarbon solvent can be used. The Ti/Mg molar ratio can vary from 1:0.1 to 1:1, though

in order to achieve the most homogeneous reaction system, a stoichiometric ratio between Ti and Mg° is preferred

1:1, as well as a quantity of hydrated metal salt which, during the reaction, ensures the supply of approx. 1 mole of water per moles of Mg°.

The hydrocarbon-soluble catalyst precursor comprises predominantly Ti constituents in association with Mg constituents, in one or more stereoconfigurational complexes which are believed to consist mainly of oxidized material types. Certain evidence for mixed oxidation states of the titanium constituents suggests a system of interrelated types of Ti V-, Ti 1 - and Ti<II-> constituents, perhaps in a quasi-equilibrium relationship, at least under dynamic reaction conditions. The preferred precursor is assumed - with reservations - to contain Ti-O-Mg bridge structures.

The catalysts obtained by the method according to the invention may or may not be deposited on supports, and are of particular interest for the isomerisation, dimerisation, oligomerisation or polymerization of alkenes, alkynes or substituted alkenes in the presence or absence of reducing agents or activators, e.g. .ex. organometallic compounds of metals from groups IA, IIA, HIA or IIB.

In the preferred use of the catalysts, these are combined with an organometallic compound to form a catalyst system which is adapted in particular for the polymerization of ethylene and comonomers into polyethylene resins.

The transition metal component is an alkoxide, usually

a titanium or zirconium alkoxide comprising mainly

-OR substituents, where R can have up to 10 carbon atoms, preferably 2-5 carbon atoms and is preferably n-alkyl, such as

n-butyl. The selected component is usually liquid under normal ambient conditions and at the reaction temperatures, to facilitate handling. To facilitate application, the component is also hydrocarbon soluble.

In order to be able to carry out the hydrolysis reaction more easily, it is usually preferred to use transition metal compounds that only contain alkoxide substituents, although other substituents can also come into play when these do not interfere with the reaction in the sense that they significantly modify the performance in the later use. Generally, the halogen-free n-alkoxides are used.

The transition metal component is provided in the transition metal's highest oxidation state, in order, among other things, to provide the desired stereo configuration. As mentioned above, it is particularly preferred that the alkoxide is a titanium

or zirconium alkoxide. Suitable titanium compounds include titanium tetraethoxide and the related compounds containing one or more alkoxy radicals, including n-propoxy, iso-propoxy, n-butoxy, isobutoxy, secbutoxy, tertbutoxy, n-pentoxy, tertpentoxy, tert-amyloxy, n-hexyloxy, n-heptyloxy , nonyloxy, etc.

Certain things indicate that the rate at which the normal derivatives are hydrolysed decreases with increasing chain length, and that the rate decreases with the molecular complexity, namely with whether the molecule is tertiary, secondary or normal, and such considerations must therefore be taken into account when choosing a preferred derivative. In general, titanium tetrabutoxide has proven to be very suitable for use according to the invention, and related tetraalkoxides are also preferred. It will be understood that mixed alkoxides can very well be used, and that such can be used when they are readily available. Complex titanium alkoxides which occasionally contain other metal components can also be used.

The reducing metal is supplied at least in part in oxidation state 0, as a necessary element of the reaction system. A suitable source is the commonly used turning chips or bands or powders. As sold, these materials may be in a passivated surface oxidized state, and it may be desirable to paint the materials to provide at least some fresh surface, at least to control the rate of reaction. The reducing metal can be supplied in whatever form is found to be appropriate, such as in the form of an entrainment in the transition metal component and/or the hydrocarbon diluent, or it can be added directly to the reactor.

Both for in situ production and for independent production of the polymeric transition metal alkoxide, the water-releasing source or the water-related material is provided, whereby certain amounts of water are released or diffused or become available in a regulated, delayed manner during the reaction. As mentioned above, the coordination sphere provided by a hydrated metal salt has

proved to be suitable for the purpose, but other sources for providing water in the same quantity ratios are also applicable. Thus, calcined silicic acid can be used

gel which is free of other active ingredients, but which contains certain amounts of bound water, is used. Generally, the preferred water source is a water complex, where water is co-ordinated with the base material in a known manner.

Suitable materials include the hydrated metal salts, especially the inorganic salts, such as the halides, nitrates, sulfates, carbonates and carboxylates of sodium, potassium, calcium, aluminum, nickel, cobalt, chromium,

iron, magnesium and the like.

The mutual reaction between these components

is suitably conducted in a closed reactor, which is preferably provided with a reflux cooler for volatile components at the elevated temperatures that occur in the reaction vessel. Autogenous pressure is used, as the reaction

runs smoothly under normal ambient conditions, as heating is carried out to start and maintain the reaction.

As in any such reaction, stirring is preferred, simply to avoid caking or coating the vessel walls, to achieve intimate mixing of the components and to achieve a homogeneous reaction system.

Generally, a hydrocarbon solvent, such as hexane, heptane, octane, decalin, white spirit and the like, is also used to facilitate the mixing of the components, the heat transfer and the maintenance of a homogeneous reaction system.

Saturated hydrocarbons with a boiling

point in the range from 60 o to 190 r,C. The liquid transition metal component can also serve at least partially as a reaction medium, especially when no added solvent is used. The reaction involves a step where additional volatile components form azeotropes with the solvent, or, if the components are used without solvent,

constitutes the material returned during the reflux cooling, but in both cases it is preferred, at least in order to carry out the reaction through the intermediate steps with a suitable reaction time, to return volatile components to the reaction zone. Thus butanol is formed when the titanium component is titanium tetra-n-butoxide, forming an azeotrope with the hydrocarbon solvent. Choice of solvent and/or alkoxide with a view to a possible suppression of ■ the reaction temperature must therefore be taken into account, as will be well known to the person skilled in the art.

To a certain extent, the reaction temperature can be selected within a wide range, depending on the reaction rate that is considered appropriate. It has been shown that the reaction system (consisting of the liquid transition metal component, the dissolved hydrated metal salt, reducing metal particles and solvent, when such is desired) gives visible gas formation at approx. 60 o - 70 °C, which suggests a starting temperature or an activation energy level of approx. 50°C, which therefore constitutes the minimum temperature required for reaction of the polymeric oxide

alkoxide with the reducing metal. The reaction is somewhat exothermic during the consumption of the reducing metal, and can therefore be easily carried forward to the subsequent step, which is the step of return by reflux cooling. Since the alkanol that is formed is largely consumed during the continuous reaction (as an independent substance), the temperature of the system will change, and the completion of the reaction will be indicated by consumption of visible metal and/or reaching the reflux temperature of the pure solvent in as little time as from 30 minutes to 4 hours or more. Such temperatures can reach up to 140° - 190°C. Of course, higher temperatures can also be used, but without thereby achieving any demonstrable advantage. It is most appropriate to operate in the range from 50° to 150°C, preferably in the range from 70° to 140°C. In the absence of solvent, the upper limit will simply be determined by the reflux temperature of the alkanol formed during the reaction.

The reaction between the components is clearly evident by the marked color change, with exothermic temperature development, which accompanies the beginning of gas evolution. When the solution is not so cloudy as to prevent observation, a clear development of gas, which can vary from bubbling to strong effervescence, is seen on the surface of the metal, and the generally faintly colored solutions immediately assume a gray tone, after which they quickly darken and pass in blue color, sometimes violet, usually blue-black, sometimes with a greenish tone. Analysis of the gas gives no evidence of HC1, and the gas consists mainly of . After the rapid color change, a certain darkening of the color takes place during a gradual increase in temperature, during continued gas evolution. During this step, the alcohol corresponding to the alkoxide used is formed in an amount sufficient to suppress the boiling point of the solvent, and the alkanol appears to be gradually consumed at the same rate as the remaining reducing metal.

The reaction product is at least partially hydrocarbon-soluble, and it is conveniently kept in slurry form for the subsequent activation with a halide activator. The viscous to semi-solid product is isolated and is shown by X-ray diffraction analysis to be mainly amorphous in nature.

The molar ratio between the components can vary within

for certain limits, without this significantly affecting

the use of the catalyst precursor works in the last step of the process according to the invention, consisting in an activation with a halide activator. In order to

thus, to avoid competing reactions that make the reaction product inappropriately gelatinous or unwieldy, the transition metal component is usually added in at least the same molar amount as the reducing metal, but the transition metal/reducing metal molar ratio can vary from 0.5:1.0 to 3.0:1.0 or more, and is preferably from 1:0.1 to 1:1. An insufficient amount of reducing metal will result in a lowering of the reaction temperature, so that the reflux temperature for the pure solvent is not reached, while an excess of reducing metal will immediately make itself felt in that part of it is not consumed.

It will thus be easy for a person skilled in the art to determine the desired amount of this component.

Within these ranges, a varying proportion of the reaction product may constitute a hydrocarbon insoluble component which, however, can and usually is slurried with the soluble component prior to the final reaction with a halide activator to form the olefin polymerization catalyst. The amount of such insoluble component can be partially regulated by using a solvent with a suitable distribution coefficient, but in cases where the use of a common hydrocarbon solvent, such as octane, is preferred for practical reasons, equimolar quantity ratios of e.g. Ti/Mg/H20 components proved to be best suited for the formation of a homogeneous reaction product.

The water-releasing substances are also supplied

preferably in the same molar amount as the transition metal component, also in this case for reasons of homogeneity and a smooth progress of the reaction. When using MgClj • 6^0, a quantity of 0.17 mol will thus add approx. 1 mol of water, and an amount from this amount up to approx. 2 moles of water give the simplest reactions, together with one or more moles of the transition metal component. More generally, the amount of 1^0 can vary from approx. 0.66 to 3 mol per moles of transition metal. The amount of water present at any stage of the reaction will of course tend to be considerably smaller and may extend down to catalytic amounts in relation to the other components, depending on the manner in which and the speed with which the water participates in the reaction sequence, which is currently unknown. However, it is assumed, with all caveats, as a working hypothesis that the water, or the reaction rate regulating the water-related material, is activated, released, made available or diffused in a manner that provides such material in a steady, stepwise, constant or variable manner quantity-related way. However, when the same molar amount of free water is added at the beginning of the reaction, it is totally ineffective in initiating the reaction at this or higher temperature, and such an addition results in undesirable, complete hydrolysis reactions.

The measured amount of water is mainly in molar balance or in a molar excess in relation to the reducing metal component and seems to be related to the consumption of this in the reaction, as a molarly insufficient amount of water will always result in an excess of reducing metal. Generally, a moderate excess of water of 10 - 40% is appropriate to ensure complete reaction. Larger amounts can also be used, but they should be kept in relative stoichiometric balance with the transition metal component.

The choice of aquocomplexes or hydrated metal salts, when such are used, is mainly a question of the regulated amount of water these add to the system. Thus, sodium acetate trihydrate is applicable and likewise magnesium acetate tetrahydrate, magnesium sulfate heptahydrate and magnesium silicon fluoride hexahydrate. A salt of maximum degree of hydration consistent with the controlled release provided, through the coordinated binding relationship, is preferred. It is most appropriate to use a hydrated magnesium halide, such as magnesium chloride hexahydrate or magnesium bromide hexahydrate. These salts, like other hygroscopic materials, contain a certain amount of sorbed water, even when added in commercial, anhydrous form,

e.g. 17 mg/kg (see British Patent No. 1 401 708), although this amount is far below the molar amounts that come into consideration according to the invention. Anhydrous qualities of the salts are thus not applicable, unless they are specially modified for the purpose.

The reaction system, as defined in the above description, does not require (although it will "be able to tolerate)

an electron donor or Lewis base or a solvent that partially exerts certain functions. As shown in the examples, the reaction is carried out in the preferred embodiment with water of crystallization and an alcohol component in the system. It is therefore not known with certainty whether proton transfer or electron donor mechanisms participate or compete in the reaction system.

No separations are necessary, then at least one

part of the reaction product is soluble in the saturated hydrocarbon, when such is used as a solvent, or

provides a solubilizing medium, so that a usable, reactive suspension is obtained, even when a precipitate also forms, and even after storage.

The obtained reaction product (catalyst precursor) is then reacted with a halide activator, such as an alkyl aluminum halide, a silicon halide, an alkyl silicon halide, a titanium halide or an alkyl boron halide. It has been shown that the catalyst precursor is easily activated by simply bringing the product together with the halide activator. The reaction is strongly exothermic,

and therefore the halide activator is usually added gradually to the reaction system. After the addition is complete, the reaction will also normally be complete, and it can then be terminated. The solid reaction product obtained or the suspension obtained can then be used immediately or stored for later use. In order to achieve the best possible control of the molecular weight properties, and especially for the production of low density resins, usually only the hydrocarbon washed solid reaction product is used as catalyst.

The halide activator is usually added in molar ratios of from 3:1 to 6:1 (aluminum, silicon or boron to the transition metal), although molar ratios of 2:1

and higher have been shown to give good results.

The obtained catalyst product can be used directly

in the polymerization reaction, although it is usually diluted, mixed out or reduced as needed to provide in an appropriate feed material an amount of catalyst equivalent to 80 - 10 mg/transition metal, based on a nominal productivity higher than 200,000 g polymer per g transition metal in continuous operations polymerizations, which performance the present catalyst usually exceeds. Adjustments can be made, by the expert, according to reactivity and degree of effectiveness, usually by dilution and regulation of supply rates.

For use in polymerization, the transition metal-containing catalyst is preferably combined with an organometallic cocatalyst, such as triethylaluminum or triisobutylaluminum or a non-metallic compound, such as triethylborane. A typical feed material to a polymerization reactor thus comprises 42 parts isobutane solvent, 25 parts ethylene, 0.0002 part catalyst (calculated as Ti) and 0.0009 part cocatalyst (TEA calculated as Al), the reactor being kept at 4 5, 7 kg/cm 2 and 71.1 oC. If a cocatalyst is used, the amount of this is usually calculated to be between 30 and 50 ppm, calculated as Al or B, calculated on the amount of isobutane.

Examples of metallic cocatalysts are trialkyl-aluminium compounds, such as triethylaluminium, triisobutylaluminium, trioctylaluminium, alkylaluminium halides, alkylaluminium alkoxides, dialkylzinc, dialkylmagnesium and metal borohydrides, including those of the alkali metals, especially sodium, lithium and potassium as well as of magnesium, beryllium and aluminium. The non-metal-containing cocatalysts include boron alkyl compounds, such as triethylborane, triisobutylborane and trimethylborane, and hydrides of boron, such as diborane, pentaborane, hexaborane and decaborane.

The polymerization reactor is preferably a ring reactor adapted for operation with a slurry, using a solvent, such as isobutane, from which the polymer is separated as a granular, solid substance. The polymerization is carried out at low pressure, e.g. at pressure from 14.1

to 70.3 kg/cm and at a temperature in the range from 37.8° to 93.3°C under pressure of hydrogen as desired to regulate the molecular weight distribution. Other n-alkenes can be added to the reactor in smaller quantities in relation to the amount of ethylene, for copolymerization with the ethylene. In typical cases, butene-1 or a mixture of butene-1 and hexene-1 is used,

in an amount of from 3 to 10 mol%, although other α-olefin comonomers and quantity ratios can also be used. By using such n-alkene comonomers, resin densities in the range from 0.91 to 0.96 can be achieved.

Also other α-olefin comonomers can be used, such as 4-methyl-pentene-1, 3-methyl-butene-1, isobutylene, 1-heptene, 1-decene or 1-dodecene, in amounts of from as little as 0, 2% by weight, especially when monomer mixtures are used.

The polymerization can nevertheless also be carried out

at higher pressures, e.g. at pressures in the range from 1400 to 2800 kg/cm 2 , in autoclave reactors or tube reactors, if desired.

When reference is made here to an intermetallic "compound" or "complex" is meant any reaction product, whether this has arisen by coordination or association or in the form of one or more inclusion or occlusion compounds, symbionts or other form of bonding under the applicable conditions, the integration reaction usually manifests itself by color change and gas evolution, which probably reflects reduction-oxidation, rearrangement

and association between the consumed elements in the reaction system.

The following examples illustrate the invention, although not all examples illustrate all steps of the method according to the invention. All parts are calculated on a weight basis, unless otherwise stated. The melt index was measured according to ASTM D-12 38-57T, under conditions E and F respectively what

NI and HLMI values are relevant, as it is indicated whether the measurement was made with a powder sample or a resin sample. HLMI/MI or MIR is the melt index ratio, which is a measure

on the shear sensitivity and reflects the molecular weight distribution. Other examinations are as indicated or as conventionally carried out in the subject.

Example 1

A. 6.0 Parts Ti(OBu) [TBT] and 4.2 parts CrCl36H20

were brought together in a reaction vessel. The chromium salt was partially dissolved, and some heat generation took place during stirring. Complete dissolution was achieved by gentle heating to 60 - 70°C. A further 3.3 parts of chromium salt were dissolved with stirring over 20 minutes. To the green solution, a total amount of 0.3 part magnesium turning shavings was added in portions, which caused strong gas evolution.

The cooled reaction product, which was free of excess

of magnesium (the magnesium had completely disappeared), was a viscous, green liquid, which was soluble in hexane.

B. In a similar experiment, anhydrous chromium chloride was used together with the titanium alkoxide. No reaction took place, not even when heated to a temperature above 100°C for half an hour. The addition of zinc dust and further heating at a temperature above 150°C did not lead to any reaction either. Nor did any reaction take place when magnesium turning chips were used. It was concluded that the hydrated salt is a necessary component of the reaction system.

Example 2

A. 0.21 mol TBT, 0.015 mol CrCl 3 .6H 2 O and 0.0075 mol Mg° were brought together in a stirred reaction vessel equipped with an electric heating jacket. The chromium salt dissolved completely at 66°C, and the reaction with the magnesium turnings manifested itself in gas evolution at 85°C, which gas evolution was strong at 100°C and subsided at 116°C, with some Mg remaining. After dissolving the remaining amount of Mg, the heating was continued until a total reaction time of 1 hour and 45 minutes. The reaction product at room temperature was a dark green liquid which dissolved easily in hexane.

B. Similarly, a reaction product was prepared using 0.116 moles of TBT, 0.029 moles of CrCl3.6H20 and 0.029 moles of Mg. A muddy green reaction product at 118°C assumed a marked bluish color at 120°C with continued gas evolution. The reaction was terminated after the magnesium had disappeared after 1 hour and 15 minutes. The reaction product was soluble in hexane. C. The experiments described above were repeated using the following reactant amounts: 0.116 mol TBT, 0.058 mol CrCl 3 .6H 2 O, and 0.0145 mol Mg. The reaction was complete within 115 minutes. A hexane-soluble product was obtained. D. The quantity ratio between the reactants was again changed in a further experiment to 0.115 mol TBT, 0.0287 mol CrCl3.6H20 and 0.0144 mol Mg. A sludgy, green material appearing at 114°C turned blue on the Mg surface. The recovered reaction product was soluble in hexane.

E. In a similar experiment, 0.176 mol of TBT, 0.30 mol of CrCl3.6H20 and 0.176 mol of Mg° were converted into octane. The clear green color of the reaction mixture at 70°C turned into a mud color with increasing gas evolution and darkened to almost black at 90°C. The color returned to green at 119°C, and the reaction was terminated at 121°C with complete disappearance of the magnesium. The reaction product (6.9 wt% Ti, 3.5 wt% Mg, 1.3 wt% Cr) consisted of a dark olive green liquid and a darker colored solid (in a volume percentage of about 50:50), which sedi -mented.

F. In a further experiment, which was carried out in octane, the reactants were added in the proportion of 0.150 mol TBT, 0.051 mol CrCl3.6H2<D and 0.150 mol Mg. Also in this case, the muddy green color changed to an almost black color under vigorous effervescence, forming a dark blue to black reaction product at 109°C (5.7 wt% Ti, 2.9 wt% Mg, 2.1 wt% Cr).

Example 3

A. The reaction product from example 2, point E, was brought into contact with isobutylaluminum chloride in a reaction vessel, which was added drop by drop in such an amount that a molar ratio Al/Ti of 3:1 was obtained. The green color of the mixture initially changed to a brown-violet color at 38°C, but after completion of reactant addition at 39°C the color had become red-brown. After 30 minutes of further stirring, the reaction was complete. The product consisted of a dark reddish brown liquid and a dark brown precipitate.

B. The reaction product from example 2, point F, was

similarly reacted with isobutyl aluminum chloride (in a molar ratio Al/Ti of 3:1). The peak temperature after complete addition was 48°C, but no color change to brown could be observed. The reaction product was a clear liquid and a dark gray precipitate.

Example 4

The catalysts prepared in Example 3 above

was used for the polymerization of ethylene (87.8°C, 10 mol% ethylene, 0.0002 part catalyst calculated as Ti, 45 ppm triethylaluminum, calculated as Al, and the amount of H2 as indicated) with the results listed in table I below:

In the following example, the catalyst prepared according to the invention was prepared from the reactant mixture in the absence of added solvent.

Example 5

A. 0.1212 mol Ti(OBu)4 [TBT], 0.121 mol magnesium turnings and 0.0012 mol MgCl26H20 (molar ratio TBT/Mg/MgCl2.6H20 1:2:0.01) were brought into contact with each other in a stirred reaction vessel equipped with an electric heating mantle. The magnesium salt was completely dissolved at room temperature, forming a homogeneous reaction mixture. The mixture was heated gradually, and at 95°C gas evolution took place on the surface of the magnesium turning chip. At 140°C with reflux cooling, the bubbling had become strong. The color of the solution darkened and the bubbling stopped at 170°C, whereupon the reaction was complete. The reaction product contained an excess of magnesium (only approx. 8.5% of the added magnesium had reacted) and was soluble in hexane.

B. In another experiment, the amount of MgCl2.6H20 was increased (molar ratio TBT/Mg/MgCl2.6H20 = 1:1:0.1). The pale yellow liquid assumed a grayish color during gas evolution at 104°C and darkened on further heating to 168°C. After 125 minutes of reaction time, the reaction product contained a certain excess of magnesium. About 63% of the magnesium had reacted. C. In a further experiment a molar ratio of 1:1:0.17 was used. The dark blue reaction product was very viscous and did not easily dilute with hexane. All magnesium was consumed.

The following example shows the manufacture carried out

in a hydrocarbon solvent.

Example 6

A. To a stirred reaction vessel equipped with an electric heating jacket was added 50.2 parts (0.148 mol) TBT and 58.6 parts octane. 0.074 mol of magnesium turnings was added, after which stirring was started and 0.0125 mol of MgC₂-Br₂O was added with heating over 1 minute. At 75°C (after 20 minutes) the magnesium salt had completely dissolved, and at 95°C (after 25 minutes) gas evolution began on the surface of the magnesium turnings. The evolution of gas increased as dissolution assumed

a grayish color and then a deep blue color, with reflux at 117°C (after 35 minutes). The magnesium metal had reacted completely within 1 hour (128 - 129°C),

and the reaction was complete. The dark blue reaction product, solubilized in octane (a small amount of a greenish precipitate remained), was calculated to contain 6.8% by weight

Ti and 2.0 wt% Mg (weight ratio Ti/Mg = 3.4:1; molar ratio Ti/Mg = 1.7:1).

B. The preceding experiment was repeated essentially as described, except that the molar ratio between the reactants was changed as indicated in the following table, where the results are also indicated. C. The experiment where the molar ratio 1/1/0.34 was used was repeated, except that 63.7 parts of TBT were used, together with 67.5 parts of hexane as the dissolution and reaction medium. A dark blue to black liquid was obtained, which on calcination gave 8.2 wt% Ti and 1.6 wt% Mg.

The following example shows the step-by-step preparation of the catalyst.

Example 7

2.61 parts MgCl 2 -6H 2 O and 34.2 parts TBT were brought together with stirring. Within 30 minutes, the yellow liquid-crystalline salt mixture had been replaced by a milky yellow, cloudy, viscous liquid. Continued stirring resulted in a gradual disappearance of the turbidity, so that within 2 hours a clear, yellow liquid was obtained (in a second experiment,

which was carried out in octane, within 30 minutes the salt was completely dissolved, so that a yellow liquid was obtained without the appearance of any precipitation or turbidity).

A TM-Mg reaction product was prepared in the same manner as in the preceding examples, using the clear yellow liquid prepared above and 1.83 parts of Mg°, using a mole ratio between the components of 1/0.75/ 0.128

in octane. The reaction proceeded evenly and smoothly to a dark-blue to black liquid with a green precipitate, in the same way as for other of the reactions discussed.

The reaction product was activated with ethyl aluminum dichloride using an Al/Ti ratio of 3/1 to form a catalyst for olefin polymerization.

The following example shows the importance of the amount of bound water.

Example 8

A number of identical experiments were carried out during application

of the molar ratio 1/0.75/0.128 (TBT/Mg/MgCl2.6H20), the degree of hydration of the magnesium salt being however changed.

When MgCl2.4H20 was used (H20/Mg = 0.68/1, compared to 1:1 for MgCl2.6H20), only 89.1% of the magnesium metal reacted. Use of MgCl2.2H20 in the same molar ratio (H20/Mg 0.34/1) gave only 62.1% conversion of Mg°.

In repeated experiments, the amount of hydrated salt added was increased to give a H 2 O/Mg molar ratio of 1/1. All the magnesium metal reacted. It was also observed that the amount of insoluble reaction product increased with increasing amount of salt.

The following example shows the use of other titanium compounds.

Example 9

A. To a stirred reaction flask equipped with an electric heating jacket was added 45.30 parts (0.1595 mol) Ti(OPr<1>)4, 0.1595 mol Mg and 50.85 parts octane, after which

0.027 mol MgCl2.6H20 was added. The milky yellow mixture turned gray at reflux temperature, at ca. 88°C,

and changed to a blue color at 90°C, with strong gas evolution. On the basis of the magnesium residue, it was concluded that the reaction was partially suppressed by the octane/isopropanol azeotrope present.

B. The reaction described above under point A was repeated with a reactant mole ratio of 1/0.75/0.128, using decalin (boiling point 185 - 189°C) as diluent. After 6 hours, the reflux temperature had reached 140°C, and the reaction was terminated. A dark blue to black liquid was obtained, with a small amount of dark precipitate. Only 8.8% of the magnesium had reacted. C. Similarly, a reaction was carried out with tetraisobutyl titanate, using a molar ratio of 1/0.75/0.128, whereby a blue-black liquid and a dark precipitate were obtained. About. 50% of the magnesium reacted. D. Titanium tetranoylate was used similarly, along with magnesium and MgCl 2 .6H 2 O, using a molar ratio of 1/0.75/0.128. A blue liquid was formed.

45% of the magnesium was consumed.

E. The reaction product of titanium tetrachloride and butanol (believed to be dibutoxytitanium dichloride) was reacted with magnesium and magnesium chloride hexahydrate in a molar ratio of 1/0.75/0.128 under similar conditions as in the above examples. Approximately half of the magnesium was consumed during approx. 3 hours, after which a dark blue-black liquid and an olive-green precipitate (in the volume ratio 50/50) were recovered.

The following example describes the use of a zirconium alkoxide.

Example 10

A. 12.83 parts (0.028 mol) Zr(OBu)4.BuOH , 0.34 parts (0.14 mol) Mg° in the form of commercially available turning chips and 8.8 parts octane were placed in a reaction vessel and heated to reflux temperature at 125°C with stirring during 15 minutes, with no sign of any reaction. 0.97 parts (0.005 mole) of MgCl 2 .6H 2 O was added, after which vigorous effervescence was observed and the reaction mixture assumed a darkish appearance.

B. In a second experiment, 31.7 parts (0.069 mol) of the zirconium compound were contacted with 0.069 mol of magnesium metal turnings and 57.6 parts of white spirit (boiling point 170 - 195°C), and 4.79 parts (0. 0235 mol) MgCl2.6H20

was added while stirring. Heat was supplied to the reaction vessel through an electric heating jacket. During the 5

minutes, the reaction mixture had become opaque, and gas evolution from the surface of the magnesium metal was observed when the temperature had reached 85°C, after 8 minutes of reaction time. The gas evolution continued under strong effervescence,

and the temperature rose to 108°C, when a whitish solid appeared. After continued heating to 133°C (1 hour reaction time), all magnesium metal had disappeared, and the reactor contained a milky white liquid and a white solid. The reaction mixture was cooled, and 92 parts of a mixture containing 6.8 wt% Zr and 2.4 wt% Mg (weight ratio Zr/Mg = 2.8:1; mole ratio Zr/Mg = 0.75) were recovered. and which was soluble in hydrocarbons.

The reaction product is activated in a manner known per se with e.g. an alkyl aluminum halide, the reaction can conveniently be carried out using a molar ratio Al/Zr of from 3/1 to 6/1, whereby, in combination with an organic or metal-organic reducing agent, an olefin polymerization catalyst system adapted for the production of polyethylene resin is obtained.

The following example shows the use of calcium instead of magnesium as the reducing metal.

Example 11

A. 0.074 mol Ti(OBu) , 0.074 mol Ca° (thick turning chips which are a commercial product and which were cut into smaller pieces)

and 0.0125 mol MgCl2.6H20 were brought together in octane in a re-

stirred reaction vessel equipped with an electric heating jacket. After reaching the temperature of 105°C the color of the solution darkened, and at 108°C the solution assumed a dark gray appearance with gas evolution. At 110.5°C, gas evolution was rapid, and the liquid turned dark blue. After 90 minutes, the reaction was terminated and a reaction product consisting of a dark blue-black liquid with a greenish tone was isolated.

The experiment was repeated using the same molar ratio. 50% of the calcium reacted and a dark blue liquid and a gray solid containing 6.2 wt% Ti, 2.6 wt% Ca and 1.1 wt% Mg were formed (molar ratio l/0.5/0.34 )

(UA^ .

In another experiment, the same reactants were used in the molar ratio 0.75/0.128. 63% of the calcium reacted, and a blue-black liquid and a green solid were formed. The reaction product (molar ratio 1/0.47/0.128) contained 6.6 wt% Ti, 2.6 wt% Ca and 0.4 wt% Mg (11A2).

B. The reaction product 11A^ was reacted further with ethyl aluminum chloride in molar ratios AlTi of 3/1 and 6/1. The reaction products were diluted with hexane, and the halide activator was added slowly to control the highly exothermic reaction. In the experiment where a molar ratio of 3/1 was used, the initially formed warm white suspension dissolved to form a lighter liquid and a white precipitate when the reaction was complete. In the experiment where an Al/Ti molar ratio of 6/1 was used, the suspension changed to a gray color and then to a yellow-green color.

The reaction product 11A2 was likewise treated with EtAlCl2 using Al/Ti molar ratios of 3/1 and 6/1. The reactions proceeded evenly and smoothly and formed at molar ratios

3/1 a dark brown slurry and at molar ratio 6/1 a reddish brown

liquid with a brown precipitate.

C. The reaction products prepared under part B were used for the polymerization of ethylene, with the results listed in the following table.

The experiments showed that a somewhat wider molecular weight distribution was achieved in the polymer than when magnesium was used as the reducing metal.

The following example illustrates the application of

zinc as reducing metal.

Example 12

A. 0.204 mol TBT, 0.153 mol Zn° granules and 0.026

moles of MgClj^H^O were brought together in octane in a stirred, closed system equipped with a reflux condenser and external heating jacket.

In the course of 13 minutes (85°C), a rapid color change to a blue-black color took place, with an increase in gas evolution to strong effervescence and foaming. The reaction product, which consisted of a blue-black liquid (no precipitation), and which contained 7.7 wt% Ti, 0.9 wt% Zn and 0.5 wt% Mg, faded to a yellow color when exposed to air.

B. The reaction product TiZnMg (molar ratio 1/0.86/0.128) was reacted with isobutylaluminum chloride in the molar ratio Al/Ti = 3/1, in hexane at 10 - 13°C (126^ . C. The preparation of the TiZnMg reaction product (12A) was repeated using Zn dust, with similar results. In a further experiment with mossy zinc, only 7% of the zinc was consumed, and a green layer was formed on the surface of the zinc. D. The activated reaction product 12B^ prepared as described above was washed thoroughly in hexane and used for the production of low density polyethylene resin The reactor was precharged with a sufficient amount of butene-1 to ensure the desired density and the reaction was carried out (with stepwise addition of butene-1 and ethylene) at 76, 7°C

and 2.4 6 kg/cm 2 , in the presence of triethylaluminum as cocatalyst. The recovered resin had the following properties: density = 0.9165, MI = 1.68, HLMI = 52.1 and MIR = 31.

Examples 13 - 14 show the use of aluminum as a reducing metal.

Example 13

A. 112.31 parts (0.33 mol) Ti(OBu)4, 8.91 parts

Al° (Alfa Inorganicspherical aluminum powder, - 45 mesh and 11.4 parts (0.056 mol) MgCl2.6H20 (molar ratio 1:1:0.17) were mixed in a reaction vessel with stirring, heat being supplied via an electric heating jacket.

When 100°C had been reached during approx. 10 minutes, the yellow color deepened, and at 118°C a vigorous effervescence with gas evolution began. At 122°C, the liquid boiling under reflux assumed a gray color, and the temperature stabilized as the reaction mixture changed color from a deep gray color with a bluish tone to a dark blue color and then a blue-black color after 27 minutes of reaction - and heating time. The temperature was maintained and it rose to 175° in 1 hour 20 minutes, at which time gas evolution was essentially complete and the reaction was terminated.

At room temperature, the reaction product was a viscous liquid containing unreacted aluminum particles. The unreacted aluminum was separated, washed and weighed. It turned out that 6.7 parts of Al° had been converted. The reaction product contained 7.9 wt% Ti, 3.4 wt% Al and 0.7 wt% Mg (molar ratio 1:0.75:0.17).

B. 9.10 parts of the reaction product prepared as described above (0.719 parts Ti or 0.015 mol Ti) was added in 13.0 parts hexane to a reaction vessel in a cooling bath. 0.045 mol of ethylaluminum chloride was added gradually, keeping the temperature at 15-20°C. After stirring the mixture for 30 minutes, a dark red-brown slurry and an intractable solid (B^) were obtained.

A second experiment (0.175 mol Ti/0.0525 mol Al) was performed without cooling to a peak temperature of 38°C. Again, a red-brown slurry was formed with an unwieldy solids deposit (B2).

Example 14

The reaction products from example 13 were used as catalysts in the polymerization of ethylene under standard conditions (87.8°C, 4.2 kg/cm<2> H2) using triethylaluminum as cocatalyst. The following results were obtained:

Example 15

A. In a similar manner to the above, 0.133 mol of TBT, 0.100 mol of Al° and 0.017 mol of A1C13.6H20 were added in octane and reacted during 7 hours and 15 minutes, whereby a dark blue-black liquid and a small amount of of a gray solid. About. 40% of the aluminum reacted, forming a reaction product containing 6.6% by weight Ti and 1.6% by weight Al (15A1).

In the same way, the same reactants were reacted with each other in the molar ratio 1/1/0.17. About. 58% of the aluminum reacted, forming a reaction product containing 6.5% by weight Ti and 2.7% by weight Al dSA^).

B. The reaction products (15A1) and (15A2) were activated with ethyl aluminum chloride using an Al/Ti ratio of 3/1. The solid portion of the activated reaction product (15A2) was isolated from the supernatant liquid and used with TEA as a cocatalyst in the polymerization of ethylene at 76.7 o C and 1.05 kg/cm 2 , whereby a resin characterized by MI was produced in an experiment = 0.02, HLMI = 1.01 and MIR = 50.5 and in a second attempt a resin characterized by MI = 0.02, HLMI = 0.45 and MIR = 22.5 was produced.

The following examples show the preparation of catalysts using other aquo complexes.

Example 16

A. 0.0335 mol TBT and 0.0335 mol Mg° were stirred in octane in a heated reaction vessel, to which was added 0.0057 mol MgBr2.6H20 (molar ratio 1/1/0.17). The salt was dissolved within 6 minutes by heating to 65°C. A gray color developed during strong gas evolution, and the solution changed to a blue color, after which it became blue-black with a greenish tone. The reaction was terminated at 123°C (approx. 10% unreacted Mg) after a reaction time of 4 hours and 10 minutes (16A).

In a similar manner, a reaction product was prepared using a molar ratio Ti/Mg/MgBr2.6H20 = 1/0.65/0.11. The reaction product was a blue-black liquid with a dark green precipitate (6.5 wt% Ti; 2.5 wt% Mg (after calcination)).

B. The decanted reaction product (16A) was brought

in contact with isobutylaluminum dichloride using Al/Ti ratios of 3/1 and 6/1 by gradual addition of the alkyl aluminum halide. In the first experiment (Al/Ti = 3/1) a peak temperature of 42°C was reached at an addition rate of one drop per 2 - 3 seconds, after which the green liquid changed to a brown color. The reaction product was a red-brown liquid with a brown precipitate (4B - 1). The product produced with an Al/Ti ratio of 6/1 (4B - 2) was produced in a similar manner and with the same result.

In a separate experiment, the reaction product (16A) was brought into contact with SiCl^ in the same way. The reaction product obtained after 30 minutes of reaction using a Si/Ti ratio of 3/1 was a pale yellow liquid with a brown precipitate. A similar experiment gave a reaction ion product with Si/Ti = 6/1.

C. The activated reaction products 16B-1 and 16B-2 (1 wt% Ti) were used for the polymerization of ethylene (10 mol% in isobutane) at 87.8°C, using a hydrogen modifier and a triethylaluminum cocatalyst (45 ppm Al), and the experiment was compared with a similar experiment where magnesium chloride hydrate was used. The results are listed in Table III below.

Example 17

A. 42 , 23 parts (0.124 mol) of TBT were contacted

with 3.02 parts (0.124 mol) Hg in 42.8 parts octane in the presence of 5.7 parts (0.02 mol) FeCl3.6H20 (molar ratio TMgFe =

1/1 0.17) in a closed, stirred reaction vessel equipped with a reflux condenser and an electric heating jacket. Heating was started and within 6 minutes, at 65°C, gas evolution began. The sludge yellow color changed to dark brown at 80°C (7 minutes), and gas evolution increased. In the course of 30 minutes, gas evolution had slowed down, and then ceased when all the Mg° was consumed, whereupon the reaction was terminated. The very dark liquid showed no sign of any residue (17 A-^).

In a second experiment, the same reactants were reacted with each other in the molar ratio TMgFe = l/l/o.34 and similar results were obtained. Dilution with hexane caused no precipitation or deposition of residue (17A2).

B. The reaction product 17A^ was activated by reaction with a 50% by weight solution of ethyl aluminum chloride in hexane, using an Al/Ti ratio of 3/1. A brown liquid and a brown solid were recovered, containing 16.5

Mg Ti/g (176.^ .

In a similar way, the reaction product (17A2) was activated. The dark brown liquid changed to a violet slurry and then to a dark gray slurry. The obtained clear liquid and the gray precipitate contained 16 Mg Ti/g.

C. The activated reaction product 17B^ was used

by polymerization of ethylene at 87.8°C and 4.22 kg/cm<2> H2. 114,320 g of polyethylene was extracted per g Ten per hour. The polyethylene exhibited the following properties:

MI = 5.1. HLMI = 155.3, MIR =30.3.

Example 18

A. 0.160 mol Ti(0Bu)4, 0.160 mol magnesium turnings

and 0.02 7 moles of CoCl 2 .6H 2 O were added to a stirred reaction vessel along with 61.2 parts of octane. The violet cobalt salt crystals gave a dark blue solution on dissolution. The mixture was heated, using an electric heating mantle,

and gas evolution on the magnesium surface began at 58°C and increased to vigorous effervescence at 107°C within 12 minutes.

The clear blue color changed to a greyish color on further heating and became almost black at 123 - 25°C, when all the magnesium had disappeared and the reaction was complete, after 90 minutes. The milky blue reaction product was hydrocarbon soluble and separated into a dark blue liquid and a dark precipitate on standing.

The experiment was repeated, with practically identical results.

B. The reaction product from the above experiment was shaken, and 0.0111 mol Ti together with 0.0333 mol Al was added dropwise to a reaction container. A temperature peak of 40°C was reached, with the formation of a greyish precipitate, which on further addition of BuAlCl2 changed to a brown colour. After stirring for a further 30 minutes, the reaction was terminated. A dark red-brown liquid and a brown precipitate had been formed. C. The catalyst component prepared in example 18 above was used for the polymerization of ethylene (87.8°C, 10 mol% ethylene, 0.0002 part catalyst calculated as Ti, about. 45 ppm triethylaluminum calculated as Al and H2 as indicated) with the results listed in Table IV below.

Example 19

A. 0.169 mol Ti(OBu)4 [TBT], 0.169 mol magnesium turnings and 0.029 mol AlCl3-6H2O in octane as diluent were added to a stirred reaction vessel equipped with an electric heating jacket. The hydrated aluminum salt was partially dissolved, and at 111°C the solution quickly darkened to a black liquid, which erupted violently as gas evolved from the magnesium's surface. The solution assumed a blue color and, on gentle refluxing at 122°C, formed a dark blue-black liquid containing some traces of magnesium. At 125°C all the magnesium metal had disappeared and the solution had assumed a faint green tint. The reaction was terminated, and a dark blue-black liquid and a green precipitate were recovered in a volume ratio of approx. 95/5.

B. The reaction product obtained as described above was brought into contact with isobutylaluminum chloride in molar ratios Al/Ti of 3:1 and 6:1 by dropwise addition of the chloride to

a reaction vessel containing the titanium material. During the first reaction (3:1) the alkyl chloride was added at a rate of 1 drop per 2 - 3 seconds until a peak temperature of 42°C had been reached, causing a color change from blue-green to brown. After stirring for an additional 30 minutes, the reaction product, which consisted of a red-brown liquid and a brown precipitate, was isolated (19B).

C. In a similar way, a product with Al/Ti =

6:1 prepared, with the same results (19C).

D. Reaction products 19B and 19C were used together with a triethylaluminum cocatalyst (45 ppm Al) for the polymerization of ethylene (10 mol%) with isobutane diluent at 87.8°C and an amount of hydrogen as indicated. The experiments were terminated after 60 minutes, with the results listed in Table V below.

Example 20

A. 0.153 mol of Ti(0Bu)4 [TBT], 0.153 mol of Mg° turnings, and 0.026 mol of NiCl^eHjO were added along with 61.75 parts of octane to a stirred reaction vessel equipped with an electric heating jacket. On heating to 4 4°C, the yellow-colored solution assumed a deeper color, and it could be observed

gas evolution on the magnesium metal surface at approx. 57°C.

With continued heating, gas evolution increased until the reaction system at 102°C (after 15 minutes of reaction) assumed a light, muddy brown colour. Vigorous effervescence was continued with accompanying darkening of the brown color until all the magnesium had disappeared at 126°C (75 minutes) and the reaction was terminated. The reaction product (20 A-I) consisted of a hydrocarbon soluble dark brown liquid and a small amount of a fine precipitate.

In a second experiment, 0.149 mol TBT, 0.149 mol Mg and 0.051 mol NiCl 2 .6H 2 O were added in octane in the same way. The magnesium metal disappeared at 115°C (after 120 minutes), and the reaction gave a dark brown to black hydrocarbon-soluble liquid, which on standing separated into a very fine, dark precipitate and a yellow liquid, which was present in a 50/50 volume ratio ( 20A-2).

B. Reaction product 1A-1 was shaken, and a portion (0.0137 mol Ti) was placed in a reaction vessel with hexane diluent, to which iBuAlCl 2 (0.0411 mol Al was added dropwise, at a rate of one drop per 2 - 3

o

seconds, up to a temperature of 28 C, and at a rate of 1 drop per second to a peak temperature of 39°C. After the addition was complete, the contents of the container were stirred for 30 minutes, after which the reaction product, consisting of a dark red-brown liquid and a dark gray precipitate, was isolated (20B-1).

The same reaction product (20A-1) was contacted with ethyl aluminum chloride in the same manner, using an Al/Ti molar ratio of 3/1. The reaction product consisted of a dark reddish-brown liquid and a dark gray solid (20B-2).

In substantially the same manner, the reaction product 20A-2 (having a Ti/Mg/Ni molar ratio of 1/1/0.34) was contacted with iBuAlCl 2 using an Al/Ti molar ratio of 3:1. The same results were obtained, except that the supernatant had a pale red-brown color (20B-3).

In a further experiment, the reaction product 20A-2 was reacted in the same way with iBuAlCl2 using an Al/Ti molar ratio of 6:1. In a similar way, a dark liquid and a dark precipitate were formed (20B-4).

The same reaction product 20A-2 was reacted with ethylaluminum chloride in the same manner, during which a dark red-brown liquid and a dark gray solid (20B-5) were formed.

Example 21

A. Example 20 A was repeated, the reactants being added in a molar ratio Ti:Mg:Ni of 1:0.65:0.11. The color change was from a deep brown-yellow color to a deep brown color, with accompanying gas evolution, and then the color change went through a gray-brown color to a dark blue-black color, during which the magnesium was used up. The reaction lasted over 6 hours. (21a) .

B. The reaction product 21A was reacted with ethylaluminum chloride in the same manner as in Example 20B, using an Al/Ti molar ratio of 3:1. A red-brown liquid and a red-brown precipitate (21B) were recovered.

Example 22

Example 21A was repeated, with the reactants added in the molar ratio 1/0.75/1.28. The dark brown reaction product contained 5.9% Ti, 2.2% Mg and 0.97% Ni.

The reaction product was then treated with isobutylaluminum chloride using an Al/Ti molar ratio of 3/1.

Example 2 3

A series of TMgNi catalysts, which were prepared as indicated in Examples 20B and 21B, were used as catalyst components in the polymerization of ethylene (87.8°C, 10 mol% ethylene, 45 ppm triethylaluminum calculated as Al and H2 as indicated), with the results listed in Table VI below.

Example 24

A. TBT, Mg° and MgSiF6.6H20 were reacted with each other

in octane in a heated reaction vessel equipped with a reflux condenser in the same manner as in the preceding examples, for the preparation of reaction products using molar ratios of 1/1/0.34 and 1/0.75/0.128 respectively.

B. The latter reaction product was activated by reaction with ethyl aluminum chloride using an Al/Ti molar ratio of 3/1.

C. The resulting brown precipitate was separated

the above reddish-brown liquid and used together with TEA

for the provision of approx. 4 5 ppm Al under standard conditions for polymerization of polyethylene (87.8°C , 4.22 kg/cm<2 >H ). The polyethylene was produced in a quantity of 107,500 g PE/gTi/h and was characterized by MI = 2.85, HLMI = 84.5

and MIR = 29.6.

D. The reaction product (molar ratio 1/1/0.34) prepared as above was likewise activated with isobutylaluminum chloride using an Al/Ti molar ratio of 3/1. The solid reaction product was washed several times with hexane and used with TEA in a polyethylene polymerization reactor which had previously been fed with butene-1 to obtain a polymer with the desired density, at 76.7°C and 2/11 kg/cm 2 Yi^ i from e thy len/butene-1 as starting material. The resulting polymer had a density of 0.919 3 , MI = 1.91, HLMI = 60.8 and MIR = 31.8.

In the following example, catalyst components were activated by reaction with a halide component.

Example 25

A. In the following experiments, TMMg reaction products were reacted with the halide component, which was added gradually, usually dropwise, to control the exothermic reaction. The reaction was carried out under ambient conditions,

for a sufficient time to complete the addition while stirring the reactant, namely for 10 - 30 minutes after reaching the peak temperature (where this was possible the solid and liquid TMMg components were mixed together into a slurry and used in this form). The reactants and the quantity ratio between the reactants were as follows:

Example 26

A. Catalyst samples activated with Bi^AlC^ (molar ratio Al/Ti = 3:1) were used in a series of polymerization experiments, with the results listed in Table VII below.

As will be seen when comparing the molar ratios indicated under Ti/MgC^•6H20, the highest melting index was obtained with a molar ratio of 9:1 (molar ratio Ti/H20 = 1.5:1).

B. In the following, additional experiments, the effect of the Al/Ti ratio in the activated TMMg catalysts (molar ratio 1/0.65/0.11) was investigated in the polymerization of ethylene. The results are set forth in the following Table VIII.

C. In a further series of experiments, where a TMMg catalyst with a molar ratio of 1/0.75/0.128 was used, the effect of the activator was examined, with the results set out in Table IX below. D. Large scale polymerization experiments were carried out at 71.1°C using the TMMg catalyst (molar ratio 1/0.75/0.12 8) (slurry, separation of the supernatant and washing with hexane) and a TEA cocatalyst. Ethylene and butene-1 were used as a comonomer, varying the amount of butene-1 in the supply and likewise the activator and the amount of activator. The results are listed in Table X below. The polymer batches prepared as indicated above were stabilized with 100 ppm calcium stearate and 1000 ppm Irganox 1076. They were tested using the conventional tests and were transferred to a blown film in a 1 1/2" (38.1 mm) Hardig extruder (screw at 60 rpm; 3" (76.2 mm) nozzle with nozzle opening 0.082" (2.08 mm); cooling air of 2.8 - 4.4°C) and then retested, all as indicated below in Tables XI and XII. E. In further polymerization experiments carried out on a large scale, carried out in a similar manner and using TMMg catalyst (slurry, separated from the supernatant and washed with hexane() in the molar ratio 1/0.75/0.128 (3/1 Al/Ti, EADC), heaene-l was fed to the reactor as a comonomer together with ethylene, after which butene-1 was added instead, which gave ethylene/butene-1/hexene-1 copolymers and terpolymers, as identified by exhaust gas analysis. The results are listed in Table XIII.

Example 27

A TMMg catalyst which was prepared according to the examples and which had been activated with isobutylaluminum chloride (Al/Ti = 3/1), was likewise used for the production of other copolymers, using varying amounts of comonomers and using isobutane as diluent, a reactor temperature of 76.7°C, a hydrogen pressure of 2.1 - 2.8 kg/cm 2 and an amount of TEA to provide 60 ppm Al, with the following results:

Polymerization or copolymerization of other α-olefin monomers, such as propylene, 4-methylpentene-1, the alkyl acrylates and methacrylates and alkyl esters can be carried out in a similar manner.

The following comparison tests were also carried out:

COMPARISON EXAMPLES

A. In the reaction vessel used in the other preparations, TBT, Mg° and anhydrous MgCl2 were brought together in octane in a molar ratio of 2/1/0.34 and heated at reflux temperature for 15 minutes, with no sign of reaction . The anhydrous MgCl2 remained undissolved. See also example IB above.

B. To the same system an amount of free water corresponding to a ratio Mg°/MgCl2•6H20 of 1/0.34 was added all at once, but no change could be detected. C. TBT and Mg° were brought together in a molar ratio of 2/1 in octane and the mixture was heated to reflux temperature. Although the yellow color became somewhat stronger, no signs of reaction were seen. D. To system C above, an amount of free water corresponding to a ratio Mg/MgCl2•6H20 of 1/0.34 was added. A small amount of a pale yellow precipitate was formed, indicating hydrolysis of the titanium compound, but the magnesium remained unreacted.

E. TBT and MgCl 2 -6H 2 O were brought together in octane in a molar ratio of 1/0.34 and the mixture was heated to reflux temperature. After the salt was completely dissolved, the solution became cloudy and somewhat viscous upon continued refluxing for 3 hours, but it cleared and sedimented to a cloudy yellow liquid and a whitish precipitate on standing overnight. A further experiment using a molar ratio of 1/0.128 gave a clear, golden yellow liquid when heated at reflux for only 16 minutes. When using a molar ratio of 1/1.17, foaming and formation of a thick, cream-coloured gel led to termination of the reaction after 45 minutes, cf. example 7 above.

Claims (7)

1. Method for producing a catalyst for use - possibly together with a co-catalyst - in the polymerization of α-olefins, characterized in that: (a) a transition metal alkoxide is partially hydrolyzed to a polymeric transition metal alkoxide, (b) the polymeric transition metal alkoxide is reacted with a reducing metal with a higher oxidation potential than the transition metal, and (c) the product from step (b) is activated with a halide activator. 2. Method according to claim 1, characterized in that the partial hydrolysis is carried out with a water complex as water donor. 3. Method according to claim 1, characterized in that the partial hydrolysis is carried out with water provided by means of a hydrated salt of aluminium, cobalt, iron, magnesium or nickel. 4. Method according to claim 1, characterized in that the partial hydrolysis is carried out with water provided by means of a hydrated oxide, preferably a silicic acid regel. 5. Method according to claims 1-4, characterized in that the reducing metal used is magnesium, calcium, zinc, aluminum or a mixture of two or more of these. 6. Method according to claims 1-5, characterized in that a molar ratio between transition metal and water of from 1:0.5 to 1:1.5 is used. 7. Method according to claims 1-6, characterized in that an alkyl aluminum halide is used as halide activator.