SE411550B - CATALYST FOR POLYMERIZATION OF OLEFINES CONTAINING THE REACTIVE PRODUCT OF A METAL ORGANIC COMPOUND OF ALUMINUM WITH A PRODUCT CONSISTING OF ANhydrous MAGNESIUM HALOGENIDE AND HALOGENATED TITANIC SUBSTANCE ... - Google Patents

Description

731-2267-3 but of particles which reproduce or "repeat" the shape of the particles in the starting catalyst.

Examples of supported catalysts leading to polymers which repeat the spherical or spheroidal shape of the catalyst are found in U.S. Pat. No. 3,594,330 and in German Offenlegungsschrift No. 1,957,705.

The polymer granules obtained with the hitherto known supported catalysts and which give rise to the phenomenon of "repetition" are brittle or easily baked together when subjected to pressure. It is known that the granulation phase used in the conventional processes for producing the crystalline polymers of olefins is a cumbersome operation, which considerably impairs the economics of the processes. A large number of attempts have already been made to eliminate this phase.

The only processes known hitherto, in which it has been possible to obtain directly useful polymers without granulation in conversion processes into manufactured products, are characterized by the use of unsupported Ziegler-Natta catalysts, in which the titanium trichloride, which was used as catalyst component, is prepared according to a special technique from TiCl4 by reduction with organic aluminum compounds.

The polymers obtained with these catalysts are obtained in the form of a powder with narrow granulometry, in which the particles do not reproduce a regular geometric shape and decompose when subjected to abrasion tests.

Furthermore, these non-granulated powders find use only in fiber production processes.

It has now surprisingly been found that supported catalysts can be prepared for the polymerization of olefins which have a very high activity and which at the same time can give rise to crystalline polymers in the form of spherical or spheroidal particles which show considerable resistance. against crumbling and compaction.

The catalysts of this invention are prepared by reacting: a) an organometallic compound of aluminum with b) a product consisting of a support comprising an anhydrous magnesium dihalide and a halogenated titanium compound chemically bonded to the support or dispersed thereon, which product has the form of spherical or spheroidal particles of a size between 1 and 350 μm, which are characterized by values of the mechanical resistance to supersonic vibration expressed in Wh / liter, by values of the mean radius of the pores and the specific surface, which satisfy the following relationship: the mechanical resistance is between 5 and 40 Wh / liter, the average radius is 3 x 10-3 pm to 7 x 10-3 pm while the specific surface area is greater than 3 m2 / g and less than 70 m2 / g.

By the mean radius of the pores is meant the ratio 2V / S.104; where "V" denotes the total porosity of the particles expressed in cm 3 / g and where "S" is the specific surface area expressed in m2 / g.

Mechanical resistance to supersonic vibrations refers to the minimum specific energy (Wh / liter) that must be supplied to the particles of the catalyst component suspended in an inert liquid in order to achieve their almost complete decomposition. The term "almost complete decomposition" means that more than 80% of the particles have an average size below the initial size.

For the catalyst component according to the invention, the measurement has been carried out by subjecting to the action of the supersonic vibrations a suspension of the particles in anhydrous heptane, in a concentration of 2-3% by weight, placed in a glass test tube immersed in a water bath.

As a source of supersonic vibrations, an apparatus was developed which developed a specific power between 10 and 80 W / liter and which had a frequency between 22.4 and 45 kHz.

The specific power of the apparatus is expressed by the ratio between the power of the transducer and the volume of liquid (through which the supersonic energy is dissipated) placed in a metal container to which the transducer itself is mounted. 731-226? Each specimen is subjected to successive treatments of increasing strength (duration and force) until almost complete decomposition of the particles is achieved. After the treatment and the previous separation of most of the heptane, the samples are photographed under an optical microscope.

It has been possible to perform a calculation of the lowest energy which produces almost complete decomposition on the basis of only a simple comparison between the different photographs, thanks to the fact that the specimens or samples after treatment showed uniformity in the granulometric distribution. Particularly interesting results with regard to the mechanical resistance of the spherical or spheroidal particles of the polymers have been obtained with catalysts, in which component b) is characterized by supersonic resistance values between 10 and 30 Wh / liter and by an average pore radius between 3.5 x 10 and 6 x 10-3 pm.

The ability of the catalysts of the invention to give crystalline polymers of the olefins in the form of spherical or spheroidal particles which neither decompose nor compress is so much more unexpected when one considers that the catalysts which differ from the catalysts of the invention only by the fact that their supported Catalyst components exhibit other values of the mechanical resistance to supersonic vibrations, on the specific surface and on the average radius of the pores, do not give rise to the phenomenon of "repetition" or, if they do, the spherical or spheroidal particles they form are brittle or lightly compressed.

Component b) of the catalysts according to the invention can be prepared in different ways. The preferred method of making the component exhibiting the properties indicated in (b) consists in spraying with prior art and apparatus leading to the formation of a product with spherically shaped particles, from a hydrated magnesium dihalide which is molten or, if so, , dissolved in water, in particular molten MgCl 2 .6H 2 O, so that particles with sizes generally between 1 and 300 [mu] m are obtained, preferably 30-180 .mu.m, and these particles are then subjected to controlled treatments of partial dehydration up to a content of 3 '5 of crystalline water are brought to values below 4 mol / mol magnesium dihalide, while avoiding causing any hydrolysis reactions of the magnesium dihalide, after which the partially dehydrated particles are reacted in a liquid medium comprising a halogenated titanium compound, in particular TiCl , heated to temperatures generally higher than 10 ° C, and finally removes the unreacted titanium compound.

When using MgCl 2 .6H 2 O, the molten chloride is sprayed into a stream of either hot air or hot nitrogen gas by means of nozzles having an orifice diameter selected in such a way that the spherically shaped particles formed have a granulometry between 10 and 300 .mu.m.

The particles thus obtained, from which the finer and the coarser particles are separated by sieving, are dehydrated under conditions under which no hydrolysis of the hydrated magnesium dichloride occurs, until the amount of hydrate water is reduced to values between 0.5 and 3.5 mol / mol MgCl and preferably between 1 and 3 moles.

The partially dehydrated particles are then introduced into TiCl4 heated to boiling point, then freed from the excess TiCl4, washed in heat in fresh TiCl4 and then washed with heptane to remove any traces of TiCl4 not bound to the support.

Another way of preparing the component with the properties indicated in b) consists in spraying solutions of an anhydrous magnesium dihalide into an organic solvent with known techniques and apparatus, which is suitable for obtaining a product in the form of spherically shaped particles. , for example an alcohol, an ether, a ketone or an ester, with a boiling point between 60 and 150 ° C, under temperature and pressure conditions in which the spherically shaped particles formed generally have a granulometry between 1 and 300 Fm, is substantially free of solvents that are not chemically bound to the magnesium dihalide, and that the solvent which is bound to the carrier is then removed by heating under reduced pressure and at a temperature higher than 150 ° C and which at the end of the treatment is between 200 and sso ° c. 0, 1 and 20% by weight of the supported catalyst component. The spherically shaped particles thus obtained are then brought into contact with a halogenated titanium compound to fix the desired amount of titanium on the support. This can be achieved, for example, by suspending the particles of the carrier in an inert solvent, in which the titanium compound is dissolved in an amount corresponding to that which it is desired to deposit on the carrier, and then the solvent is evaporated.

When the catalysts of this invention are used in the polymerization of nrolefins, in particular propylene, it is convenient to treat component b) with electron donors before or after the support of the titanium compound. In these cases, the organometallic compound used to prepare the catalyst is also treated with an electron donor preferably used in amounts less than 1 mol / mol of organometallic compound, and in particular in an amount of from 0.1 to 0.4 moles. The electron donor compounds are preferably selected from the esters of organic and inorganic oxygen-containing acids and from mono- and polyamine compounds which are free from primary amino groups.

Examples of such compounds are the esters of benzoic acid and of its alkyl derivatives, N, N, N, N-tetraalkylethylenediamines, piperazine etc.

The magnesium halide can be used in admixture with 20-80% by weight of other carriers which are inert to the magnesium halide, selected from the compounds of the elements of groups I to IV of the Periodic Table of the Elements.

Examples of such compounds are Na 2 CO 3, Na 2 SO 4 and B 2 O 3.

The halogenated titanium compounds which can be used in the catalysts according to the invention include, for example, the halides, the haloalcoholates, the halamides, the ammonium halo titanates and the halo titanates, the titanium salts of organic halogenated acids. Preferably liquid titanium compounds are used, for example TiCl4, TiCl2 (OC4H9) 2, TiBr4, etc. The solid compounds, such as TiCl3, are used in the form of solutions in inert solvents of their complex with electron donors. The amount of useful titanium compound, expressed as 7312267-3 The organometallic compounds of aluminum include the aluminum trialkyl compounds and the aluminum dialkyl halides.

Examples of these compounds are Al (C2H5) 3, Al (iC4H9) 3, A1. (C3x¶7) 3, A1 (c21¶5) 2c1 ', When interested in obtaining catalysts with higher stereospecificity in the polymerization of a -olefins, were used as already stated some of the organometallic compounds in the form of corplexes with electron donor compounds.

The polymerization of ethylene and the ε-olefins, in particular propylene, butene-1,4-methylpentene-1 and mixtures of ethylene and α-olefins, with the catalysts according to the invention are carried out according to conventional methods.

The polymerization is carried out in liquid phase in the presence or absence of an inert diluent or in gas phase.

The polymerization temperature is generally between 40 and 200 ° C, preferably between 50 and 100 ° C.

The molecular weight of the polymers is controlled by the use in the polymerization phase of molecular weight regulators of known type, for example hydrogen or zinc dialkyls.

The resistance to crumbling and caking of the spherically shaped polymers obtained with the catalysts according to the invention is determined by working with the mass of granules, and not with the individual particles, according to the following methods.

To determine the resistance to crumbling, 20 g of polymer, together with two small porcelain balls (25 mm diameter), are inserted into a metal cylinder (38 mm inner diameter and 160 mm length), which also has a stopper of metal, mounted horizontally on a slide which has a barrel of 50 mm and is subjected to 240 oscillations per minute for 20 minutes.

The granulometry (with sieves from ASTM series Nos. 4, 7, 10, 18, 35 and 70) is then compared with that of the polymer as such. The polymers obtained with the catalysts according to the invention have essentially the same granulometry before and after the test. On the other hand, a considerable reduction in the size of the particles is found in the polymers obtained with catalysts which do not fall within the scope of the invention. For normal baking resistance, 4 tablets of about 10 g, which were prepared by pressing under a pressure of 394 kp / cm 2 in a cylindrical fam (1 mm-diameter), were subjected to the same treatment used. for the determination of the crumbling resistance.

If the tablets remain substantially compressed, the fine particles that have separated are weighed, but if complete disintegration occurs, the granulometry of the disintegrated material is determined using the same sieves used for the particles of the polymer as such.

The tablets of the polymers obtained with the catalysts according to the invention decompose almost completely under the influence of the treatment and thus give rise to deformed particles, which, however, have almost the same dimensions as the original small spheres.

On the other hand, the polymers obtained with catalysts which do not correspond to the properties of the catalysts according to the invention are not decomposed or decomposed somewhat under the influence of the shaking sample. As already stated, the particles of the polymers obtained with the catalysts according to the invention resist both the crumbling test and the compression test.

Another feature which can be considered as indicative of the catalyst used in the polymerization is that the particles (generally these have a diameter of 1-2 mm) have an even distribution within the mass of particles of Mg compound used as support. The remaining titanium compound present in the particle is generally present therein in an amount of less than 30 ppm titanium. The invention is illustrated by the following examples without these being in any way limiting the scope of the invention. Unless otherwise stated, percentages shall be construed as expressed in percentages by weight.

EXAMPLE 1 E§ëfߧ§ëllaia¶_ay-ë99l išë29_i_§šë: is1s_š9§s Melted MgCl2.2H2O was sprayed countercurrently with hot air into a spray cooling device from Niro Atomizer. The diameter of the spray nozzle was 0.34 mm. The overpressure was obtained with nitrogen gas. The spherically shaped particles were collected on the bottom of the dryer and then sieved to obtain a fraction between 53 and 105 Pm. The fraction thus separated was then dried in an oven at 130 ° C in a stream of nitrogen.

After drying, the product was found to consist of MgCl2.2H2O.

Ereueëëlleiæ9-ëzuêse-11222252sßeëëlxäëëerlsemeeeeeëss The equipment used consisted of a Pyrex glass reactor of about 3 liters capacity which had a sintered glass filter plate at the bottom. The heating was obtained by means of an electrical resistor wound around the lower tubular part of the reactor. Furthermore, the reactor was equipped with a reflux condenser, stirrer, thermometer and a reserve lung system for N2 pressure.

The measurement of carrier in the form of powder was carried out through an opening by means of a test tube which could be brought under N 2 pressure.

A glass flask connected to the bottom of the reactor collected the reaction and washing liquids from the filtrate, while another flask, placed at the side and connected to the top of the reactor, served to heat and feed the washing liquids.

The support reaction occurred when 2500 ml of TiCl 4 was introduced into the reactor and the temperature of this TiCl 4 was brought to its boiling point of 136.5 ° C. After boiling for a few minutes, 120 g of carrier were introduced into the reactor with vigorous stirring. The temperature then dropped, mainly due to the action of the HCl evolved in the reaction, which dissolved in TiCl 4 and caused a lowering of its boiling point.

The temperature rose gradually to 138 ° C, ie the boiling point of TiCl4 containing a certain amount of TiOCl2 as reaction by-product.

This temperature was maintained for 1 hour to complete the reaction.

Then the reacted TiCl 4, containing the by-products, was filtered under heat. Then two washes were performed with TiCl 4 in heat, then 5 times with heptane dehydrated by distillation on sodium metal.

The chemical analysis of the supported catalyst component, which was dried under vacuum, gave the following results: 2.95% Ti, 69% Cl, 20.5% Mg, 2.85% H 2 O.

The X-ray analysis showed the presence of MgCl2 and MgCl2.H2O. 7312267-3 The specific surface area of the supported component amounted to 33.7 m2 / g.

The minimum specific supersonic energy required to achieve complete rupture (crumbling) of the particles was 10.3 Wh / liter.

The average radius of the pores was 5.9 x 103 μm.

In a 4.5 liter capacity autoclave equipped with a paddle stirrer, a heating oil circuit and a cooling water circuit, 2000 ml of purified heptane containing 4 g of Al-tri-isobutyl were introduced.

The temperature was raised to about 75 ° C. Under H2 pressure produced by a lung system, the catalyst component dispersed in heptane was then introduced by means of a lung system. The amount of catalyst component introduced amounted to 0.00452 g of the supported catalyst component prepared on the previous page corresponding to 0.00018 g of titanium. Then 7.5 kp / cm 2 H 2 and 5.5 kp / cm 2 ethylene were introduced, while the temperature was raised to 8500.

The pressure was kept constant by continuous feeding of ethylene.

The polymerization was carried out for a period of 4 "h. After degassing and cooling, 740 g of polyethylene were discharged. The polymer was in the form of spherical particles with a diameter of 1-2 mm, which corresponded to the standard tests for crumbling and compaction previously described.

EXAMPLE 2 The support used was the same as in Example 1. The same applies to the method of preparing the catalyst component and the amounts reacted were the same.

With this cocatalyst, polymerization experiments were carried out with propylene in liquid propylene with and without complexing agents.

Bslxsešiëëëigaßstëßlsewelszsëiaslënds-riedel In the already described 4 liter autoclave, 3.1 g of aluminum triisobutyl in about 10 ml of heptane were introduced under an H2 atmosphere.

Using a small 2 liter bottle was fed into the autoclave 115 g of propylene. The temperature was 30 ° C. Then, by injection with H2 overpressure, using a 50 ml vial, 0.014l g of cocatalyst corresponding to 0.00045 g of titanium and 0.9 g of aluminum triisobutyl in 20 ml of hepLan were introduced.

The temperature was then raised to 60 ° C and at this temperature the pressure was found to be 27 atm (the overpressure was due to the blown H2). During 4 hours of polymerization, the pressure dropped to 21 atm. 7312267-3 ll After cooling and releasing the propylene, 750 g of polypropylene were discharged. The yield was found to be 1,670,000 g polypropylene / g titanium. The remainder of the heptane extraction was 18.8%.

After extraction of the amorphous substance, the polymer was found to be in the form of spherical particles with a diameter of about 1 mm and it withstood both the compression test and the crumbling test.

Eelzæêšiëëëiiemmeéi-riíênzlšeëfin-ëefitlsemelsëlaiaêëfzêe-Ißsëel In this example, the same autoclave and method were used as described in the experiments without complexing agents. In a stream of H2, 4 g of aluminum triisobutyl were fed into about 15 ml of heptane.

Then 1150 g of propylene were introduced. 0.009 g of catalyst was weighed (corresponding to 0.00029 g of titanium) and then fed into the small 50 ml flask containing 0.02 g of triphenylphosphine in 20 ml of heptane.

They were left in contact with each other for about 15 minutes. Then the catalyst and phosphine were blown into the autoclave with H2 pressure.

Thereafter, the temperature was raised from 50 to 60 ° C and the pressure rose to 26 atm. After 4 hours, the reaction mixture was cooled, the propylene was released and 143 g of polymer were drained. The yield was 500,000 g of polymer g / titanium. The residue from the heptane extraction was 29.5%. After extraction of the amorphous substance, the polymer was found to be in the form of spherical particles which withstood the standard predation of decomposition and comminution.

IIU __... ...___...._...._._...._......__...._ ._ ~ _..._.... .._._..._........_ .. _........_. 4 _.-...._.._........ In the autoclave already described, 3 g of aluminum triethyl in 11 ml of heptane and 1.5 g of ethyl benzoate were introduced under H2 pressure.

950 g of propylene were fed into the autoclave and the cocatalyst, 0.017 g in 20 ml of heptane (corresponding to 0.00055 g of Titanium) was blown in using the bottle under H2 pressure. The temperature was then raised to 65 ° C and the pressure set at 28 atm.

After 4 hours, the polymer mass was cooled, the gases were released and 43 g of polymer were discharged, which took the form of small liquid spheres which withstood the tests of decomposition and compression, while the yield was 78,000 g / g of titanium and the residue from the extra heptane was 63. , 6%. semestra-J.

Examples 3 and 4 are comparative examples. The preparation of the hydrated Mg chloride of spherical shape was carried out in a 6 liter jacketed autoclave equipped with a siphon for suction. 7312267-3 g '12 of the liquid phase, further with a thermocouple for measuring the temperature and a pressure gauge.

Attached to the siphon was an external sleeve-fitted tube, on the end of which the spray nozzle (0.64 mm diameter) was screwed. The heating was effected with water vapor at 45 atm which was circulated in a heating jacket.

4 kg of MgCl 2 .6H 2 O were introduced into the autoclave. The temperature was raised to 228 ° C by circulating water vapor in the jacket. Through the introduction into the autoclave of nitrogen gas, the pressure was brought to 22 atm.

After the outer part of the siphon leading to the spray nozzle was heated with water vapor, the valve was opened and the molten chloride was sprayed.

The sprayed chloride was collected in a sealed vial containing anhydrous heptane. After spraying, the spherical powder was separated from the solvent and dried in an oven at over 80 ° C in a stream of nitrogen to remove the solvent. The carrier was found to consist of spheres with a diameter below 350 μm. About 30% had a diameter below 150 Pm.

After sieving the support and then selecting the fraction between 105 and 149 μm, the latter was dried in an oven at several different temperatures.

The values for the dehydration of the spherical chloride to obtain the different degrees of hydration are given in Table 1. The preparation of the capped catalyst components was carried out using the dehydrated supports and by working according to the method described in Example 1. The reaction conditions , the amounts of reactants and the assay values for the supported components are all entered in Table 2.

The polymerizations with ethylene were carried out with the same apparatus and by the same method as described in the previous examples.

The values of the polymerization conditions, the results obtained and the properties of the polymers have been entered in Table 3. f ,, 1512262-5 2 TABLE 1 Example 3 Example 4 Example 5 Example 6 Example 7 nehyafacitation ao ° c 9s ° c 11s ° c _ 1a5 ° c I 1s5 ° c conditions: 4 h 4 '11 4 11 4 hs 11 c1 35.45 z 40.55 z 45.55 z 55.15 z 50.55 z H 2 O 51.4O Z 43.05 Z 37, 20 Z 26.80 Z ° 16, Û0 Z RX: crystal form HgCl2.6H2O MgCl2.4H2O MgCl2.4H2O MgCl2.2H2O MgCl2.H2p MgCl2.2H2 O Theoretical percentage of Cl 34.85 42.9 48.5 '54.1 62 Theoretical percentage - of 1120 53.2 42.4 54.9 21.4 15.9 TABLE 2 Example 3 Example 4 Example 5 Example 6 Example 7 Amount of carrier 7 80 g 7 80 g 60 g 80 g 39 g rxänga 'ric1 a zooo m 'zooo m1 zooo m1 zooo m1 zooom Temperature 137 ° c' .1s7 ° c 1s1 ° c 1as ° c 1s7 ° c rie _ '1 h 1 h 1 11 1 11 1 h Washing with TíC1¿ 2 2 2 2 _ 1 Washing with C7 5 S 5 _ S.'s Analysis: Z ri. 5.50 z 4.15 z 3.00 z 3.20 z 1.555: c1 s9, oo z ° 70.25 z 52.95 z 59.15 z 68.15 z ng 2o, 9s z 2o, 95 z 21 , 55 z - 22,25 z Specifiz surface in mzlg 98.2 109.9 64.9 21.3 11.4 Resistance more over ~ .sound vibrations in 11mm 3 - 3.17 2 - 3.2 '10.3 25 , 6 25,6 Poçurnas middel- _ radïn, Pm 0,0U / | l 0,0 () 'l (z 0,0Û ~' 1'i 0,003S 0,0Ü6 '¥ 7312267-3 014 Exemuel 3 Exçrevefl gl Example 5 Example 7 Example 7 Amount of Catalyfamaphene: 0.015 g 0.015 g 0.029 g 0.034 g Amount 0.00056 in ILOOOG / and 0.0_0073 g 0.00093 g 00058 g l-.íängd A1. (IC¿B9) 3 4 gg _ 4 g 4 g I »gu 4 g remperazu: _ 'i ss ° c -as ° 0 es ° c ss ° c 0590 .mm -su _ sh 'sn _ sn- sn Eten-tiyck _ 8,5 at:' 8,5 at: 8,5 at: g l8,5 atía: '8, S: ta iii-druk 0 5,5_ata g 5,5 at: 5.5 at: 5.5 at: 5.5 gata.

Amount of polynomials. 508 g 840 g 310 g '195 g' 230 g Yield, g pallet: '0 *' i Q I I g; ri '900000: 1300000 425000 210000 400000' g poIf / S kataly- -. _. anar. - 31000. issooof 12600 ~ 6100 'ssso l _ Apparent density 0,268 3/0103' -É0,300 gloss 0,000 3/0103 0,435 g / cms 0,400 3/0013 u Polymer Resistance to: söndersmn1ning_ no - .ïnj j; . j; yes. compression no no ji _ yes. and 7312267-3. 15 'smMPsL 3-10 Examples 8 and 9 are comparative examples. The catalyst components used in Examples 8-10 have been obtained by using the fraction with a granulometry of 62-105 μm, which was obtained from the hexahydrate, tetrahydrate and dihydrate of magnesium chloride in Examples 3, 4 and 6, respectively.

The catalyst components have been prepared by the same method as used in Examples 3, 4 and 6. The polymerization experiments have also been carried out under the same conditions as in the above examples.

Table 4 shows the values of the properties of the supported catalyst components, the results of the polymerization experiments and the properties of the polymers obtained. 7312267-3 Support component analysis: Ti% Cl% Mg% specific surface area 1 m2 / g Resistance to crumbling, W h / 1 Average radius, pm Polymerization: Yield 1 g pole / 9 Ti Polymer resistance to crumbling 'compression 16 TABLE 4' Ex'8 3.69 66.1 1a .9 156.1 3.8 4 6.4 0.0038 760 000 nej nej 'EX 9 3.25 68.35 19.55 32.9 6¿4 0.0034 1,066,000 no no so 10 2.55 67.35 21.40 12 25.6 0.004O 435,000 yes yes 7312267-3 17 EXAMPLE-L l 1 7 melted MgCl 2 .6H 2 O was sprayed by the method described in Example 1. The product thus obtained was sieved to separate the fraction with a granulometry between 105 and 149 Pm. This fraction was then dried in an oven at 80 ° C for 4 hours in a stream of nitrogen gas. On X-ray examination, the product was found to consist of MgCl2.6H2O. 80 g of this product were then reacted with 2000 ml of TiCl4 in the apparatus described in Example 1.

After 1 h of reaction, the excess TiCl 4 was removed while an additional 2000 mL of fresh TiCl 4, heated to 120 ° C, was added and the temperature was maintained at 137 ° C for an additional 1 h. Then TiCl 4 was drained and the product was washed 3 times with hot TiCl 4 and 6 times with heptane.

The analysis of the dry product gave the following results: 8.55% Ti, 61.45% Cl, 17.25% Mg.

The specific surface area of the product was 27, m2 / g and the resistance to crumbling of the particles was 12.8 Wh / liter. The average radius of the pores was 4 x 10-3 μm. 0.05l g of this product was used in the polymerization of ethylene under the conditions set forth in Example 1.

Thereby, 150 g of polymer were obtained, consisting essentially of spherically shaped granules, but among which there were also granules with an irregular geometric shape. The polyurea, subjected to standard tests for crumbling and compression, showed neither crumbling nor compaction.

§§MPMPEL 12 MgCl2.0.45 H2O in the form of spheroidal particles is prepared by dehydration in a stream of gaseous HCl at 110 ° C of MgCl2.6H2O with a particle size of 53-105 Pm obtained by the spray method described in Example 1 . 45 g of the product were then reacted with TiCl 4 under the same conditions as in Example 1.

The supported catalyst component thus obtained, after drying, showed the following analytical results: 0.3 2; Ti, 69.80% cl, 25.60 æ Mg.

Claims (4)

7312267-zu 18 The specific surface area was found to be 3.7 m2 / g and the resistance to crumbling was 6.4 Wh / liter. The average radius of the pores was 3.8x10_3 μm. 0.1902 g of this product were used in the polymerization of ethylene under the same conditions as used in Example 1. Thereby 70 g of polymer were obtained in the form of spheroidal particles with a diameter of 1-2 mm and which, when subjected to standard tests for determination of resistance to crumbling and compaction, neither crumbled nor compressed. A catalyst for the polymerization of olefins into spherically shaped polymer particles which exhibit considerable resistance to decomposition, comprising the reaction product of: a) an organometallic compound of aluminum with b) a product consisting of a support comprising an anhydrous magnesium dihalide and of a halogenated titanium compound which is chemically bonded to or dispersed on the support is characterized in that the support in component (b) is a hydrated magnesium dihalide which has been sputtered to form spherically shaped particles having a diameter between 1 and 300 μm. and then substantially dehydrated after reaction with a halogenated titanium compound, the titanium compound, expressed as titanium metal, being present in an amount between 0.1 and 20% by weight with respect to the supported catalyst component, and component (b) being characterized by values of resistance to crumbling under the influence of supersonic vibrations expressed in Wh / liter, on the pores s average radius and on specific surface area as follows: resistance to supersonic vibration between 5 and 40 Wh / liter, average radius between 3x10_3 and 7x10_3 Pm and specific surface area between 3 and 70 m2 / g. 2. A catalyst according to claim 1, characterized in that the organometallic compound is aluminum trialkyl partially complexed with an electron donor compound. A process for preparing a catalyst according to claim 1, wherein magnesium halide is reacted with a halogenated titanium compound and then with an organometallic aluminum compound, it may be known that a hydrated magnesium dihalide in molten form or dissolved in water is subjected to spraying to obtain spherically shaped particles, to separate particles with a diameter between 1 and 300 μm, to dehydrate dihalide particles to crystal water contents between 0.5 and 3.5 mol / mol magnesium dihalide so that the partially dehydrated particles are caused to react in a liquid medium containing a halogenated titanium compound at a temperature above 100 ° C and finally the titanium compound which is not bound to the support is removed, after which the product obtained is reacted with the organometallic aluminum compound. 4. A process according to claim 3, characterized in that the hydratescrado magnusium dihydrogen and the particulate particles containing 0.5-3.5 moles of crystal water per mole of magnesium dihalide are reacted in a liquid medium consisting of titanium tetrachloride heated to boiling point. PROMISED PUBLICATIONS: France 2,028,106 Germany 1,957,705 (C08f 1/28) US 3,642,746 (260-88.2) Austria 292,300 (CO8f 1/28)