CS196270B2 - Catalyst for olefin polymerization - Google Patents

Abstract

The invention relates to a catalyst for the polymerization of monomers, comprising an alkylaluminum compound and a brown solid mixture containing β-titanium chloride. The subject of the invention are mixtures of an organoaluminum compound and a novel brown solid which is porous, has a large surface area and contains β-titanium chloride and a small amount of an organic electron donor; they are highly active and can be used for the polymerization of α-olefins, especially propylene, to crystalline polymer products which are solid under normal conditions, with high yields. By-products of low molecular weight and especially amorphous polymer (soluble) products are formed in small amounts.

Description

The invention relates to a catalyst for the polymerization of monomers, comprising an alkylaluminum compound and a brown solid mixture containing β-titanium chloride. The subject of the invention are mixtures of an organoaluminum compound and a novel brown solid which is porous, has a large surface area and contains β-titanium chloride and a small amount of an organic electron donor; they are highly active and can be used for the polymerization of α-olefins, especially propylene, to crystalline polymer products which are solid under normal conditions, with high yields. By-products of low molecular weight and especially amorphous polymer (soluble) products are formed in small amounts.

In accordance with the invention, it has been found that a novel porous brown material with a large surface area, comprising the β-crystalline form of sulfur trichloride and a minor amount of an organic electron donor, for example an ether, is highly effective in the polymerization of α-olefins, such as propylene, when used in conjunction with an organoaluminum compound. This brown solid is particularly effective in the polymerization of propylene when used in admixture with an organoaluminum compound, particularly dihydrocarbyl aluminum chloride, since these mixtures exhibit exceptionally high polymerization rates and high yields per catalyst and, compared to commercial activated aluminum titanium chloride, produce the same or lower amounts of solubles (low molecular weight and especially amorphous polymer components). The catalyst mixtures of the invention may be further modified with additives capable of reducing the solubles to a substantially lower level without significantly affecting the yield based on the catalyst. In addition, these catalyst mixtures, modified or unmodified, are sensitive to hydrogen, used as a chain transfer agent to control the molecular weight of the polymer product, and can be used in suspension, bulk, or vapor phase polymerization.

Catalytic mixtures used for the polymerization of α-olefins, especially propylene, are evaluated from at least two points of view: their activity and yield relative to the catalyst and their ability to form a highly crystalline polymer product with a minimum of by-products of low molecular weight and especially amorphous polymer products. Increasing the activity and yield and reducing the soluble fractions are influenced by many different factors. One of them is the crystalline form of titanium chloride in catalytic mixtures based on organoaluminum compounds and titanium trichloride.

Four crystalline modifications are known

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S of titanium chloride: a, β, γ and δ and in the literature. are detailed diffraction patterns measured by the powder method for at least the first three modifications. In the commercial polymerization of propylene, the purple crystalline modifications, especially the χ-form, were preferred, while the brown 0-form was persistently rejected due to its activity and especially to the high production of soluble fractions. However, its use for cyclotrimerization of conjugated diolefinic substances is claimed in US Patent No. 3,424,774.

Recently, a porous titanium trichloride with a high surface area based on violet α-titanium trichloride was described in South African patent number 721245. In admixture with organoaluminum compounds, the catalyst is extremely active and produces high yields of polypropylene, which are not accompanied by a significant increase in the soluble fraction,

US Patent No. 3,769,233 describes a method for preparing "a catalyst consisting of purple TiCl3... from brown TiCl3, formed by the reduction of TiCl3 at a temperature below about 100 °C, by reacting brown TiCl3 with TiCl3". The purpose is to convert the known brown form of TiCl3 with a small active surface area into one of the more efficient purple forms, which are generally known for their higher polymerization rates and yields and higher stereospecificity,

US Patent No. 3,058,963 discloses polymerization using a "hydrocarbon-insoluble catalytic component" produced by reacting, for example, TiCl 3 with an aluminum alkyl compound in solution.

In U.S. Patent No. 3,116,274, ethers are used to increase the stereospecificity of olefin polymerization. The preparation procedure involves mixing an ether, titanium tetrachloride or vanadium tetrachloride, and an alkylaluminum, such as triethylaluminum or sesquichloride, and reacting the resulting product with a promoter for use in the polymerization of α-olefins.

US Patent No. 3,058,970 describes the improvement of the stereospecificity of the polymerization of olefins by using a catalytic component formed by the reaction of, for example, titanium tetrachloride and diethylaluminum chloride in the temperature range of -20 to 40°C and subsequent aging of the product at 40 to 150°C. . . ?' ·..

It has now been found, despite all the literature references, that it is possible to prepare a brown form of titanium trichloride which is highly active, gives high yields and a low soluble fraction and can be used as a catalyst component in the polymerization of α-olefins.

The invention relates to a catalyst for the polymerization of olefins, which comprises an alkylaluminum compound and a brown solid mixture comprising titanium trichloride and up to 10 mol % of at least one organic electron donor selected from the group consisting of ethers, thioethers, thiols, ketones, esters, amides, amines, phosphines and hydrocarbon stibines. ^The brown solid mixture has a surface area greater than 50 m ² /g and a pore volume greater than 0.10 cm ³ /g. . . .. ......

The said brown solid mixture is the subject of Czechoslovak patent No. 196,269 and can be prepared by a method which is the subject of Czechoslovak patent No. 196,271 and which includes the steps

a) reaction of titanium tetrachloride and trihydrocarbyl aluminum, dihydrocarbyl aluminum chloride or bromide, in a molar ratio of titanium tetrachloride to aluminum compound of about 1:3 to about 1:0.5 at a temperature below about 0 °C in the presence of inert liquids dissolving titanium tetrachloride,

b) increasing the temperature of the product of step aj to less than about 100 °C, cj reacting the solid product of step bj with at least one organic electron donor selected from the group consisting of ethers, thioethers, thiols, ketones, esters, amides, amines, phosphines and stibines of hydrocarbons, in a ratio of about 0.5 moles of donor per mole of solid to about 5 moles per mole in the presence of an inert liquid dissolving the donor and heating the product to a temperature above room temperature and below about 80 °C, dj reacting the product of step c J with an electron acceptor selected from the group consisting of titanium tetrahalide, titanium tetraalkoxyhalide, aluminum bromide, germanium tetrachloride and silicon tetrachloride, wherein the acceptor is dissolved in the inert liquid, and

e) isolating a porous brown solid with a high surface area, comprising /3-titanium trichloride and up to 10 molar %/o of said organic electron donor, from the product of step

d). The resulting solid can be used with an organoaluminum compound, especially dialkylaluminum chloride, in the polymerization of α-olefins, especially propylene.

The described brown solid preferably has a BET surface area of greater than 50 m ² /g, more preferably greater than .80 m ² /g and most preferably greater than 100 m ² /g. By color, X-ray powder diffraction patterns and chloride to titanium ratio, the inorganic portion of the brown solid is defined as essentially titanium trichloride in the β crystalline modification. Porosity measurements of the brown solid show that it preferably has a pore volume of greater than 0.10 cm ³ /g, more preferably above 0.15 cm ³ /g and most preferably above 0.20 cm ³ /g.

Determining the morphology of the brown solid by electron microscopy revealed that it was composed of irregularly shaped, somewhat round particles that appeared to be clusters of even smaller particles.

Catalytic mixtures of an organoaluminum compound and a brown solid can be used in the polymerization of α-olefins in suspension, in bulk, or in the vapor phase with excellent results.

Although the catalyst component and the organoaluminum compound are preferably used for the polymerization of propylene in order to achieve high crystallinity of polypropylene, they can also be used for other olefins with a terminal double bond of 2 to 10 carbon atoms, for example, ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, vinylcyclohexane, etc. In addition.

They can be used to prepare end-block or pure block copolymers of propylene and another α-olefin or of propylene and ethylene.

The polymerization conditions, i.e. temperature, pressure and concentration, used for the catalyst mixtures described herein are generally known for the polymerization of α-olefins, or can be easily determined by a person skilled in the art.

In the suspension polymerization of propylene with a brown catalyst component, carried out in a glass bottle, it can be observed that the polymer has a distinct brown color during the formation and until the polymerization stops, different from the purple to pink color that occurs when a purple modification of TiCl is used for the same type of polymerization, such as AATitilis. Also, the polypropylene formed with the use of the brown catalyst component in block polymerization is composed exclusively of opaque particles. The same applies to polypropylene produced with the brown catalyst component in suspension. In block polymerizations of propylene. using the brown catalyst component and R2AlCl, it was found that approximately three quarters of the portion that was designated here as hexane extractable can be removed simply by suspending the powdered product in hexane for 1/2 hour at 70 °C.

The soluble or extractable fraction can be further limited by modifying the catalyst mixture with at least one modifier, such as, for example, an amine, preferably a spherically hindered cyclic ^amine , an amine oxide, an ether, an organic phosphite, a polyether, for example diglyme, and the like. To further limit the soluble fraction, it is also possible to use mixtures of alkyl tin sulfides, such as bis-(tributyl) tin sulfide, with an amine, an amine oxide, or an organic phosphite, or mixtures of hydrogen sulfide with an amine, an amine oxide, or an organic phosphite. It is found that the latter mixtures are particularly suitable for limiting the soluble fraction, since they have only a slight effect on the polymer yield.

The invention is described in connection with the examples given below, which are, however, of an illustrative nature only. Alternatives, modifications and variations which will be apparent to one skilled in the art from the examples fall within the scope of the invention. /b·-.·;

Water and other polar substances were removed from all solvents and polymerization media before use.

X-ray powder diffraction measurements were performed on materials in sealed glass tubes in the conventional manner using a diffractometer. Porosity measurements were performed on a high-pressure mercury porosimeter (420 MPa) from American Instrument Company, Silver Springe, Md.

The surface area measurements were performed by the single-point BET method using a mixture of 10% nitrogen and 90% helium. The sample was previously exposed to a slow flow of the gas mixture at room temperature for about 1 hour, then cooled to liquid nitrogen temperature for about 45 minutes to adsorb nitrogen, and finally warmed to room temperature, and the composition of the desorbed gas was measured with a thermal conductivity detector.

Chemical analyses were carried out by dissolving weighed samples of the catalyst in methanol or water acidified with sulfuric acid. Aliquots of this solution were used to determine titanium and aluminum by atomic absorption and chlorine by Volhard titration. Ether was determined by neutralizing methanolic solutions or extracting aqueous solutions with hexane and injecting the obtained samples into a gas chromatograph column, calibrated with standard solutions containing the relevant ether.

The brown catalyst component described herein forms a purple solution when decomposed by dissolution in dilute sulfuric acid and a blue solution when decomposed by dissolution in MeOH-H2SO4.

Slurry rates are grams of crystalline polymer (total polymer minus soluble fraction) per gram of brown solids (calculated as TiCls) per hour of polymerization. Block rates are grams of total polymer per gram of brown solids (calculated as TiCls) per hour of polymerization.

The weights given are the weights of the brown solid used. The small organic content was generally neglected in calculating the moles of the brown solid.

Example

24.6 ml of dry hexane and 12.5 ml of titanium tetrachloride are placed in a 3'00 ml round-bottomed flask. The flask and its contents are protected by a layer of dry nitrogen throughout the preparation. The solution is stirred with a magnetic stirrer and cooled in an ice bath maintained at 1°C. 74.8 ml of diethylaluminium chloride in hexane (24.4 wt. % diethylaluminium chloride, solution density 0.739 g/ /cm ³ ) are added dropwise to the titanium tetrachloride solution over a period of three hours. After the addition of the alkyl is complete, the suspension is stirred at -1 °C for 15 minutes, a condenser is provided and then heated to 65 °C over 1 hour. The suspension is then stirred at 65 °C for 1 hour. After cooling to room temperature, the solid is washed with five 42 ml portions of dry hexane: decantation of the last wash is carried out at 65°C.

The solid was decanted, 144 ml of dry hexane and 21.3 ml of isopentyl ether were added and the suspension was stirred for 1 hour at 35° C. The solid was then washed with five 42 ml portions of dry hexane by decantation.

To the decanted solid was added 70.8 mL of a 20.3% (v/v) stock solution of titanium tetrachloride in hexane (46.3 mL titanium tetrachloride plus 181.8 mL hexane). The suspension was stirred at 62-65°C for 2 hours and cooled to room temperature. The solid was washed with five 42 mL portions of dry hexane and decanted with the last wash at 65°C. The solid was decanted and 50 mL of dry hexane was added. 1.0 mL of the final suspension contained 0.295 g of brown solid.

The powder X-ray diffraction pattern, measured for a dry brown-colored solid, shows peaks corresponding to

5.8 w, 5.4 s, 2.89 w, 2.77 s b, 2.15 m, 1.96 w, 1.78 m-s b, 1.48 w, vb, 1.14 vvw.

Measuring the surface area of the dry brown solid gave a value of around 106 m ² /g.

Analysis of the brown colored solid revealed that it contained 22.5% titanium, 0.6% aluminum, 59.8% chlorine, and 10.0% isopentyl ether.

Example 2

Place in a 50 ml round-bottomed flask

49.2 ml of dry hexane and 25 ml of titanium tetrachloride. The flask and its contents are protected by a layer of dry nitrogen during the preparation. The solution is stirred slowly with a magnetic stirrer and cooled in an ice bath at a temperature of -1 °C. Add dropwise over 3 hours

149.6 ml of diethylaluminum chloride in hexane (24.4 wt. % diethylaluminum chloride, solution density 0.739 g/cm ³ }. After the addition of the alkyl is complete, the suspension is stirred slowly for 15 minutes at -1 °C, equipped with a condenser and then heated to 65 °C over 1 hour. The suspension is then stirred slowly for 1 hour at 65 ^° C. After cooling to room temperature, the solid is washed with five 84 ml portions of dry hexane; decantation during the last wash is carried out at 65 °C.

The solid was decanted, 288 ml of hexane and 42.6 ml of isopentyl ether were added and the suspension was stirred slowly for 1 hour at 35° C. The solid was then washed with five 84 ml portions of dry hexane and the resulting suspension was divided into four equal portions.

One portion is decanted and 54.5 mL of a 13% (v/v) solution of titanium tetrachloride in hexane is added to the solid. The suspension is stirred slowly at 65 °C for 2 hours and cooled to room temperature. The solid is washed with five 25 mL portions of dry hexane; the final wash is decanted at 65 °C. The solid is decanted and an additional 50 mL of hexane is added. 1.0 mL of the final suspension contains 0.141 g of brown solid.

The powder X-ray diffraction pattern, measured for a dry brown solid, shows peaks corresponding to 5.8 w, 5.4 s,

2.75 b s, 2.14 m, 2.00 m-s, 1.96 w, 1.77 bs,

1.52 w, 1.49 vw, 1.13 vw,

Analysis of the brown solid gave values of 26.6% titanium, 0.6% aluminum, 58.2% chlorine, and 9.5% isopentyl ether. Example 3

The procedure is the same as in Example 2 except that after dividing the suspension into 4 equal portions, one portion is decanted and 35.4 ml of a 20.3% (v/v) solution of titanium tetrachloride in hexane is added to the solid. The suspension is stirred slowly at 65 °C for 105 minutes and cooled to room temperature. The solid is washed with five 25 ml portions of dry hexane; the decantation of the last wash is carried out at 65 °C. The solid is decanted and 50 ml of hexanes is added. 1.0 ml of the final suspension contains 0.158 g of brown solid.

The powder X-ray diffraction pattern, measured for a dry brown solid, shows peaks corresponding to 5.9 vw, 5.4 s,

2.9 w, 2.75 b m, 2.12 /m, 1.99 m-s, 1.95 w,

1.77 watts and 1.48 watts.

Analysis of the brown solid gave values of 26.2% titanium, 0.7% aluminum, 59.4% chlorine, and 6.3% isoperityl ether.

Example 4 j/

The procedure is the same as in Example 1 except that after washing the solid with five 42 ml portions of dry hexane by decantation, 35.4 ml of a 20.3% (vol.) solution of titanium tetrachloride in hexane is added to the solid. The suspension is stirred slowly for 105 minutes at 65 °C and cooled to room temperature. The solid is washed with five 25 ml portions of dry hexane, decantation of the last wash is carried out at 65 °C. The solid is decanted and 50 ml of hexane is added. 1.0 ml of the final suspension contains 0.158 g of brown-colored solid. Example 5

The procedure is the same as in Example 4 except that the titanite chloride-isopentyl ether complex is treated with a 40% (vol.) solution of germanium chloride in hexane. Example 6

Polymerizations of propylene are carried out in a pressure cylinder at 0.28^ MPa and 70 °C in two-hour cycles with the following amounts - brown catalyst component, 1.0 ml of 24.4% (wt.) diethylaluminum chloride and 200 ml of hexane as polymerization medium.

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TABLE I

Example Weight (g) Speed g/g/h Soluble fraction %

1 0.0875 253 10.9 1 0.0875 219 2.5* 4 0.0754 213 5.4 2 0.0843 165 6.0 5 0.099 106 19.6 3 0.0948 195 5.7 **0.2 65 6.0 **0.2 35 2.2*

* In these polymerizations, 0.008 ml of bis-(tributyl)tin sulfide (BTS) and 0.004 ml of 2,4,6-collidine (Coll) were added.

** In these cases, commercially available AATiCls (Stauffer Chemical Company) was used instead of brown titanium trichloride.

Example 7

Polymerizations are carried out at 71 °C for about 1 hour in a 3.8 liter reactor at a propylene pressure of more than 1.75 MPa and at a low partial pressure of hydrogen using

1200 ml of hexane as polymerization medium. As catalyst, diethylaluminum chloride, brown titanium trichloride, BTS and Coll in molar ratio 2.8/1.0/0.014/ /0.027 are used.

TABLE II

Example Weight (g) Speed (g/g/l) Soluble fraction i( %) 3 0.1 2002 2.1** 4 0.1 2170 4.2 4 0.1 2226 2.5 4 0.1 2320 1.5** 3 0.1 1215 β β* * *** 4 0.1 1422 4.4*** 4 0.1 1583 17## * *# * 0.4 628 2.6 * 0.4 401 4.6***

* AATiCls, Stauffer Chemical Company.

** Molar ratio of diethylaluminum chloride, titanium trichloride, BTS and Coll 2.8/1/0.028/0.054.

*** Four-hour cycles.

Example 2 hours at 71 °C under propylene pressure

3.22 MPa and with a small amount of hydrogen. In

Liquid phase polymerizations of propylene (bio-metal) are carried out in a 1000-liter reactor using a 24.4% (wt.) solution of diethylaluminum chloride in hexane.

TABLE III

Example Rate (g/g/h) Soluble fraction (%) Extractable fraction and amount (g) (%)

4 0.03 3084 4.8 11.0 4 0.03 3187 1.6 4.6** 2 0.021 2390 1.3 4.2** 4 0.028 2322 0.9 2.7**, # 0.05 1186 4.3 6.8 0.05 797 3.3 3.8

* AAT1Cl3, Stauffer Chemical Company ** 0.0025 mL BTS and 0.00125 Coll *** 0.32 mL of a 24.4% (wt) solution of diethylaluminum chloride in hexane.

1θ B27Ο

Example9

A stock solution of the brown catalyst component is prepared by adding 80 ml of hexane and 40 ml of titanium tetrachloride to a 500 ml flask and cooling to 0 °C. To this solution is added 247 ml of 24.4% (w/w) diethylaluminium chloride (0.739 g/ml) over 3 hours. The resulting suspension is warmed to room temperature, heated at 65 °C for 1 hour and washed. The concentration of the suspension is determined.

ml of the latter suspension (about 6 g of solid) is placed in a 200 ml flask, decanted and 40 ml of hexane are added. 8.8 ml of octyl ether are then added and the suspension is heated at 35°C for one hour. The product is washed with hexane.

The solid was decanted from the latter suspension, to which 12 ml of hexane and 4 ml of titanium tetrachloride were added. The mixture was then heated at 65°C for 1 hour, the resulting brown solid was washed with hexane, and aliquots of the suspension were used in the polymerization.

Example 10

A stock solution of the brown catalyst component is prepared as in Example 9 with the following exceptions:

1. 24.6 ml of hexane and 12.5 ml of titanium tetrachloride are cooled to 0°C and 74.8 ml of diethylaluminum chloride are added.

2. To the washed solid from 1., add 144 ml of hexane and 20.1 ml of benzyl isopentyl ether.

3. To the solid from 2. add 60.4 ml of an 11.9% (w/w) solution of titanium tetrachloride in hexane.

Example 11

Example 10 is repeated except that in step 3, 79.5 ml of a 9.04% (w/w) solution of titanium tetrachloride in hexane is used.

Example 12

A stock solution of the brown catalyst component is prepared as in Example 9 with the following exceptions;

1. 196.8 ml of hexane and 100 ml of titanium tetrachloride are cooled to 0°C and 594.8 ml of 25% Et2AlCl solution are added. 400 ml of hexane are added to the washed and decanted solid.

2. To 50 ml of the suspension from 1., add 181 ml of hexane, 14.2 ml of isopentyl ether and 5.9 ml of n-butyl ether.

3. To the washed solid from 2. add 56 ml of hexane and 14.2 ml of titanium tetrachloride. Example 13

A stock solution of the brown catalyst component was prepared as in Example 12 except that 15.4 ml of isobutyl vinyl ether was used instead of isopentyl and n-butyl ether.

Example 14

A stock solution of the brown catalyst component was prepared as in Example 12 except that 11.8 ml of anisole was used instead of isopentyl and n-butyl ether.

Example 15

The following suspension polymerizations are carried out at 70°C and a propylene pressure of 0.28 MPa for 2 hours in pressure bottles using 80 mg of the brown solid from Example 9, 182 mg of Et2AlCl, 9.5 mg of BTS and 3.7 mg of Coll.

TABLE IV • Example Rate (g/g/h) Soluble fraction (%) _ , — , _ — ‘ Comparison is made with a brown catalyst component containing isopentyl ether, prepared similarly to Examples 1 to 4, which has a rate of 178 and a soluble fraction

1.3%.

Example 16 uses about 0.08 g of brown catalyst component and 1 ml of 25% Et2AlCl solution and does not use

The following suspension polymerizations are carried out as in Example 15 except that

Example

TABLE V Speed (g/g/h)

Soluble fraction (%)

10* 68.5 11* 51.7 12*** 161 13** 58 14** 65

20.3

21.5 4.2

17.2

15.5

10* *27®

The comparison is always made with a brown catalytic component containing Isopentyl ether, produced similarly to Examples 1 to 4.

* speed 165, soluble fraction 6.1, ** speed 157, soluble fraction 5.8, *** speed 170, soluble fraction 5.4.

Example 17

The following suspension polymerizations were carried out as in Example 16 except that 0.008 ml BTS and 0.004 ml Coll were used.

Example

TABLE VI Speed (g/g/h)

Soluble fraction (%)

159 1.2

55 11.6

-56 7.2 * Comparison for 12, 13 and 14 is made with a brown catalyst component containing isopentyl ether, prepared similarly to Examples 1 to 4, which has a rate and a soluble fraction of 178 and 1%, 164 and 1.2%, and 164 and 1.2%, respectively.

Example 18

The brown catalytic component was prepared according to the procedure of Example 1 with the following amounts of reagents:

1. 196.8 ml of hexane

100 ml of titanium chloride

598.4 ml Et2AlCl

336 ml of hexane for each wash,

2. 1152 ml of hexane

170 ml Isopentyl ether

336 ml of hexane for each wash,

3. 448 ml of hexane added separately from

113.6 ml of titanium dioxide

338 ml of hexane for each wash.

The resulting brown solid has a surface area of 147 m ² /g and a pore volume of 0.197 cm ³ /g. Analysis showed 26.8% Ti, 58.5% Cl, 0.36% Al and 6.41% isopentyl ether. The powder X-ray diffraction pattern shows peaks corresponding to 5.9 m, 5.4 s,

2.75 vs br, 2.13 w, 1.98 m, 1.94 w, 1.77 m br,

1.72w, 1.47w br, 1.23w, 1.13w br,

Example 19

The brown catalyst component is prepared as in Example 18. The resulting brown solid has a surface area of 101 m ² /g and a pore volume of 0.193 cm ³ /g. Analysis yielded the following values:

26.8% Ti, 60.0% Cl, 0.38% Al and 8.26% isopentyl ether.

Example 20

The brown catalyst component was prepared as in Example 19 except that the isopentyl ether was distilled over sodium before use. The resulting brown solid had a surface area of 89 m ² /g and a pore volume of 0.188 cm ³ /g.

Example 21

The polymerization of propylene is carried out as in Example 6.

TABLE VII

Example Weight (gj Speed (g/g/h) Soluble fraction (%)

18 0.08 0.08 259 263 5.0 3.9 19 0.08 264 5.7 0.08 240 5.2 20 0.08 173 8.4 0.08* . 168 1.4

* 0.008 ml BTS and 0.004 ml Coll are used.

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1S 16

Example 2

Propylene polymerizations are carried out as in Example 8.

TABLE VIII

Example Weight (g)*

0.05*

............ 0.05** ' 0.05*

0.05** * 2-hour cycle ** 4-hour cycle

Speed (g/g/hj Extractable fraction (%)

3065 3.6 2276 3.8 1766 2.9 1393 2.8

*** brown solid/Etz ratio is used

Claims (19)

SUBJECT An olefin polymerization catalyst comprising an alkyl-aluminum compound and a brown solid mixture containing β-titanium tetrachloride and up to 10 mol% of at least one organic electron donor selected from the group consisting of ethers, thioethers, thiols, ketones, esters, amides, amines , phosphines and stibins of hydrocarbons, said brown solid mixture having a surface area greater than 50 m ² / g and a pore volume greater than 0.10 cm ³ / g. 2. The catalyst of claim 1 wherein the organic electron donor is selected from the group consisting of ethers. 3. The catalyst of claim 1 wherein the organic electron donor is a single compound, namely an ether. 4. The catalyst of claim 2 wherein the ethers are lower alkyl ethers. 5. The catalyst of claim 3 wherein the ether is a lower alkyl ether. 6. The catalyst of claim 4 wherein the lower ethers are isopentyl ether and n-butyl ether. 7. The catalyst of claim 5 wherein the lower alkyl ether is isopentyl ether. 8. The catalyst of claim 2 comprising dialkylaluminum chloride and said solid mixture, wherein the ethers are lower alkyl ethers. 9. The catalyst of claim 3 comprising dialkylaluminum chloride and said brown solid mixture, wherein the ether is a lower alkyl ether. 10. The catalyst of claim 4 comprising dialkylaluminum chloride and said brown solid mixture, wherein the lower alkyl ethers are isopentyl ether and n-butyl ether. 11. Catalyst according to claim 5, characterized by YNALEZ by containing dialkylaluminum chloride and said brown solid mixture, wherein the lower alkyl ether is isopentyl ether. 12. Catalyst according to claim 4, characterized in that: The composition according to claim 1, wherein the brown solid mixture has a surface area greater than 80 m ² / g and a pore volume greater than 0.15 cm ³ / g. 13. The catalyst of claim 5, wherein the brown solid mixture has a surface area greater than 80 m ² / g and a pore volume greater than 0.15 cm ³ / g. 14. The catalyst of claim 6 wherein the brown solid mixture has a surface area greater than 80 m &^lt; ^{2 >} / g and a pore volume greater than 0.15 cm < ³ > / g. 15. The catalyst of claim 7 wherein the brown solid mixture has a surface area greater than 80 m &^lt; ^{2 >} / g and a pore volume greater than 0.15 cm < ³ > / g. 16. The catalyst of claim 4 comprising a dialkylaluminum chloride and wherein the brown solid mixture has a surface area greater than 80 m ² / g and a pore volume greater than 0.15 cm ³ / g. 17. Catalyst according to claim 5, characterized in that it contains dialkylaluminum chloride and that the brown solid mixture has a surface area greater than 80 m ² / g and a pore volume greater than 0.15 cm ³ / g. 18th catalyst according to Claim 6, characterized in that it comprises a dialkylaluminum halide, and the brown mixture peivná has a surface area greater than 80 m ² / g and a pore volume greater than 0.15 CIN ³ / g. 19. The catalyst of claim 7 comprising a dialkylaluminum chloride and wherein the brown solid mixture has a surface area greater than 80 m ² / g and a pore volume greater than 0.15 cm ³ / g.