HRP930611A2 - Catalyser system and a catalyser for the polymerization or copolymerization of ethylene with alpha olefine - Google Patents

Description

The present invention relates to the process for its preparation and its use in the process of ethylene polymerization or copolymerization of ethylene with alpha-olefin. It is known that alpha-olefins can generally be polymerized with the Ziegler low-pressure process.

For this purpose, they use catalysts, which generally contain a compound of IV elements. until VI. groups of the periodic system (compounds of transition metals), in a mixture with an organometallic compound and a hydride of elements I. to III. groups of the periodic system, they work in suspension, in solution or in the gas phase.

Catalysts are also known, in which the transition metal component is attached to an organic or inorganic solid carrier, which in the given example has been processed physically and/or chemically. Examples of hard supports are oxygenated compounds of divalent metals (such as oxides, oxidized or carboxylated inorganic salts) or hydroxychlorides or chlorides of divalent metals.

A particular carrier for a transition metal compound is a solid, free-flowing product of spray drying a solution of magnesium chloride in ethanol, such as, for example, described in USP 4,421,674 and 4,482,342. The carriers thus obtained, which have a certain alcohol hydroxyl content, are easily they react with titanium tetrachloride in such a way as to create solid components of the catalyst, which are very active in the polymerization of ethylene and the copolymerization of ethylene with alpha-olefin.

One characteristic of the catalyst components described above is the relatively low titanium content, typically of the order of 5 wt. %, expressed as metal. However, it would be desirable to provide catalyst ingredients with a higher titanium content in active form, in order to achieve improved productivity in the polymerization of ethylene with alpha-olefin.

In addition, there is a need in technology to have catalysts at their disposal, which would be able to produce ethylene polymers and copolymers of ethylene with alpha-olefins with a limited distribution of molecular masses and which would have a desirable group of properties with regard to the "melt index" ) and "shear sensitivity" and the extremely low content of fine parts. Such ethylene polymers are particularly suitable for injection molding.

We have determined that we can fulfill these requirements with the catalyst component and the catalyst in terms of the present invention.

In more detail, the catalyst ingredient in terms of the present invention is a spherical, granular, solid substance, which has at least 80% of grains with a size of 30 to 40 μm, a specific surface area of 15 to 30 m2/c, and a porosity of 40 to 80 vol.%, which can otherwise be defined with the formula (in atomic relation):

Ti1 Mg0.3-3.1Al0.4-0.65Cl3.2-8.2

(Et + OEt + OR')1,9-3

where Et means an ethyl group, OEt means an ethoxy group and OR' means an alkoxy group, which contains from 1 to 8 carbon atoms in an unbranched or branched alkyl part, and in which the ratio is between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent states in the range from 0.8 to 1/1.

In the preferred embodiment, the solid component of the catalyst has a specific surface area of the order of 20 to 30 m2/g and a porosity of the order of 60 to 70 vol.%, which can be defined with the formula (in atomic ratio):

Ti1 Mg0.95-1.5 Al0.42-0.46 Cl3.9-4.9

(Et + OEt + OR') 1.9-2.3

where Et OEt has the above meaning and OR' is an n-butoxy group, the ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent state varies between 0.9/1 to 1/1.

In addition, in the organic part of the solid component of the catalyst (Et+OEt+OR'), the alkoxy constituents are present in the following priority amounts. OEt = 5 to 10 wt. % and OR' = 20 to 30 wt. % with respect to the solid component of the catalyst.

The solid component of the catalyst in the sense of the present invention is obtained by

a) the ethanol solution of magnesium chloride is spray-dried to create a solid, granular and spherical carrier, which contains 18 to 25 wt. % of alcoholic hydroxyls expressed as ethanol,

b) we suspend that carrier in an inert liquid and put the suspension in contact and exchange substances first

- with titanium tetra-alkoxide Ti(OR')4, where R' means an unbranched or branched alkyl group, containing from 1 to 8 carbon atoms, we do this at a temperature between room temperature (20 to 25°C) and up to 90° C and with the atomic ratio between magnesium, which is found as magnesium chloride, and titanium, which is in the form of titanium tetra-alkoxide from 0.5/1 to 3/1, and then

- with diethyl aluminum chloride or ethyl aluminum sesquichloride, in this case we work between room temperature (20 to 25°C) and 80°C, in this case the relationship between chlorine atoms in diethyl aluminum or ethyl aluminum sesquichloride and alkoxy groups, which originate from titanium of tetra-alkoxide and ethanol, in the range from 0.5/1 to 1.5/1, to obtain a solid component of the catalyst, and in this component the ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent state is in the range of 0, 8/1 to 1/1,

c) and from the appropriate suspension we obtain a solid component of the catalyst.

degree (a)

When preparing the carrier in terms of the present invention, we dissolve magnesium chloride (anhydrous or containing small amounts of water, less than approx. 7 wt. %) in ethanol and spray-dry the resulting solution in a spray-drying device. We thoroughly spray the solution through a nozzle or with another equivalent device in the evaporation column of the spray drying device and bring the thus obtained liquid particles into contact with a flow of very pure nitrogen, which we bring into the evaporation chamber in the opposite or the same direction. We typically work with an inlet gas flow of the order of 250 to 400°C and an outlet temperature of 140 to 250°C, with a difference between inlet and outlet temperature of at least 40°C.

In one embodiment, we add to the ethanol solution of magnesium chloride an additional liquid compound, whose boiling point at atmospheric pressure is higher than the boiling point of ethanol, we choose this compound normally from aliphatic, cycloaliphatic or aromatic hydrocarbons or from hydroxylated polar organic compounds or esters.

In each example, if we work under the conditions described above, we can get a granular, solid substance from the spray drying device, which has the following typical properties:

- particle shape: spherical with about 80% of particles with a size of 30 to 40 μm,

- apparent particle density: from 0.2 to 0.3 g/ml,

- specific area: from 30 to 100 m2/year.

For the expediency of the present invention, it is critical that we keep the content of alcoholic hydroxyls in the catalyst carrier at a value of 18 to 25 wt. %, expressed as ethanol, with priority values from 23 to 25 wt. %.

Degree (b)

In accordance with the present invention, we suspend the solid carrier, obtained as described above, in an inert liquid, and put the resulting suspension in contact and change its substance first with measured amounts of titanium tetraalkoxide and then with measured amounts of diethyl aluminum chloride or ethyl aluminum sesquichloride.

For this purpose, we suspend a solid carrier in an inert liquid, especially in a hydrocarbon, such as n-decane, and add titanium tetraalkoxide to the suspension, diluted in the same inert liquid in the given example. A preferred titanium tetra alkoxide is titanium tetra n-butoxide. We can perform the conversion in the temperature range from room temperature (20 to 25°C) to 90°C, with priority temperatures from 30 to 60°C. Suitable reaction times are generally in the range of 30 to 120 minutes.

For the purposes of the present invention, it is critical to maintain the atomic ratio between magnesium, which is in magnesium chloride, and titanium from titanium tetraalkoxide at a value of 0.5/1 to 3/1, with priority values in the range of 0.8/ 1 to 1.5/1.

In accordance with the present invention, we add to the suspension, obtained after treatment with titanium tetraalkoxide, diethyl aluminum chloride or ethyl aluminum sesquichloride, which in the given example were diluted in the same inert liquid as we used for the suspension. We can change the material in the temperature range from room temperature (20 to 25°C) to 80°C, with priority values from 50 to 60°C. We can carry out the exchange of substances for such a long time that we achieve in the solid component of the catalyst the ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent state in the range from 0.8/1 to 1/1 and preferably from 0.9/1 to 1/ 1.

The times required for this purpose depend primarily on the temperature at which we work, and generally vary from 30 to 120 minutes.

For the purposes of the present invention, it is critical to maintain the atomic ratio between magnesium, which is in magnesium chloride, and titanium from titanium tetraalkoxide at a value of 0.5/1 to 3/1, with priority values in the range of 0.8/ 1 to 1.5/1.

In accordance with the present invention, we add diethyl aluminum chloride or ethyl aluminum sesquichloride, which in the given example were diluted in the same inert liquid, which we used for the suspension, to the suspension obtained during treatment with titanium tetraalkoxide. We can perform the conversion in the temperature range of room temperature (20 to 25°C) to 80°C, with priority values from 30 to 60°C. We carry out the conversion for so long that we achieve in the solid component of the catalyst a ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent state in the range from 0.8/1 to 1/1, preferably from 0.9/1 to 1/1.

The times required for this purpose depend primarily on the temperature at which we work and generally vary from 30 to 120 minutes.

At this stage of preparation of the solid component of the catalyst, it is critical that we work with the ratio between chlorine atoms, which are found in diethyl aluminum chloride or ethyl aluminum sesquichloride, and alkoxy groups, which originate from titanium tetraalkoxide or ethanol, in the range of 0.5/1 to 1.5/1, with priority values in the range from 0.65/1 to 0.8/1.

In addition, we found that the use of reagents diethyl aluminum chloride and ethyl aluminum sesquichloride is critical, because other alkyl aluminum chlorides (eg ethyl aluminum dichloride) do not give satisfactory results.

If we operate as described above, we obtain a solid catalyst component in terms of the present invention, which has the above-mentioned composition and properties.

The catalyst according to the present invention contains a solid component of the catalyst and trialkyl aluminum, in which the alkyl group contains 2 to 6 carbon atoms.

A preferred trialkyl aluminum is triethyl aluminum.

We normally maintain in the catalyst a molar ratio between aluminum in the trialkyl aluminum and titanium in the solid component of the catalyst from 50/1 to 200/1, with priority values of the order of magnitude of 100/1.

Such a catalyst is very active in the polymerization of ethylene or for the copolymerization of ethylene with an alpha-olefin, which contains 3 to 8 carbon atoms, such as propylene and 1-butene.

Polymerization is generally done by working with the suspension technique at a temperature of 75 to 95°C with the presence of hydrogen as a moderator.

We found that the catalyst of the present invention is particularly useful in the polymerization of ethylene into polymers of ethylene with a limited molecular weight distribution, which are suitable for processing by pressure casting.

We have established in detail that it is possible, at least if we work with priority catalysts, to obtain polyethylene, which has the desired group of properties with regard to the melting index, ASTM-D 1238 (from 6 to 10 g/103, shear sensitivity, ASTM-D 1238 (from 26 to 27.5) and the relationship between the weighted and numerical average molecular weight (Mw/Mn from 3.5 to 4.8), we obtain a polymer in granular, pourable form with an apparent density of 0.32 to 0.41 g /ml and with a very low content of fine particles (less than approx. 1%). The polymerization conditions for the production of such ethylene polymer are work in suspension, temperature of the order of 90°C, overall pressure of the order of 8.8 to 9.8 bar and approximately 40 mol % of hydrogen in the gaseous phase.

The following experimental examples illustrate and do not limit the scope of the present invention.

In more detail, examples 1, 2, 3, 6 and 7 were made in accordance with the invention. We cite other examples for comparison, especially to show the criticality of the parameters we mentioned before.

Example 1

Preparation of the bearer

33 kg of commercial MgCl2, with a water content of approx. 0.07 wt. % in the form of scales with a diameter between 0.1 and 2 mm is dispersed in 100 l of heptane and 55 kg of ethanol is added to the resulting suspension, while mixing the mass in a steel autoclave. During mixing, heat to 130°C under hydrogen pressure and obtain a uniform emulsion, which at the specified temperature is introduced into the CLOSE CYCLE, DRYER, industrial spray drying device from NIRO.

In this device, we change the emulsion into finely divided liquid particles, we work with a hydraulic nozzle with a hole of 0.7 mm and a spray cone angle of 60°. The supply pressure is 7 kg/cm2 and the flow rate is 15 l of emulsion per hour. In addition, we work with a nitrogen inlet temperature of 250°C and a gas flow outlet temperature of 160°C, with a nitrogen flow rate of approx. 200 m3/h, measured under normal conditions.

If we work under these conditions, we get a solid, granular substance on the reactor floor, which has the following properties:

- shape of particles: spherical with 80% of particles in the size of 30 to 40 µm,

- apparent particle density: 0.28 g/ml,

- content of alcoholic hydro hydroxyls: 25 wt. %, expressed as ethanol

- specific surface: 32 m2/g,

- porosity: 55% by volume.

Preparation of the catalyst component

2.45 g of the carrier, obtained as described above, was suspended in 50 ml of n-decane in a 250 ml mixing reactor. Add 7 g of titanium tetra n-butylate (atomic ratio Mg/Ti=1/1) and heat the suspension for 60 minutes at 80°C. After that time, cool to 30°C and gradually add diethyl aluminum chloride drop by drop (ratio between chlorine atoms in diethyl aluminum chloride and alkoxy groups (OEt + OBu) = 0.75/1), diluted in 35 g of n-decane. After finishing the addition, heat the suspension for 30 minutes at 60°C and filter the solid substance on a plate made of sintered glass. Thus we get 8 g of solid catalyst ingredient, we wash that solid ingredient with three portions of 100 ml of n-decane.

The solid component of the catalyst has the following properties:

- shape and size of the particle: similar to the carrier,

- titanium content: 12.5 wt. %, expressed as metal,

- the relationship between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent state:

0.98/1,

- apparent density: similar to that of the carrier,

- specific surface: 30 m2/g,

- porosity: 65% by volume,

Such a catalyst ingredient contains in mass. % :

titanium: 12.5, magnesium: 5.8, aluminum: 3.1, chlorine: 35, organic part: 43,

If we express the above ingredients with their atomic relationship, we can present the catalyst ingredient with the following formula:

Ti1 Mg0.96 Al0.46 Cl3.96 (Et + OEt + OBu)2.35,

where OEt and OBu are present in amounts of 5.8 wt. % and 29 wt. % catalyst ingredient,

Polymerization of ethylene

1820 ml of anhydrous n-heptane, 0.68 g of triethyl aluminum and 32 g of the solid catalyst ingredient, prepared as mentioned above, are successively introduced into the mixing reactor with a capacity of 5 l.

We raise the temperature in the reactor to 90°C and add hydrogen at 3.7 bar. Then we introduce ethylene up to 8.8 bar and maintain that pressure for the next 4 hours with continuous ethylene addition. At the end of that time period, we stop the polymerization by introducing into the reactor 20 ml of 10 wt. %-no alcoholic solution of IONOL.

The obtained polyethylene has the following values:

productivity: 22, expressed as kg of polyethylene per g of solid catalyst component,

gain: expressed as kg of polyethylene per g of titanium in the solid component of the catalyst.

Polyethylene thus obtained has the following properties:

melting index ASTM-D 1238 7.8 g/10'

shear sensitivity ASTM-D 1238 26

the relationship between the average molecular weight (weighted) and the average molecular weight (numerical). Mw/Mn = 3.8

density: ASTM-D 2839 0.962 g/ml

physical form of the polymer: loose grains with an average diameter of 300 to 350 μm

apparent density: 0.38 g/ml

content of fine particles (<74 μm) 0.3 wt. %

fraction, which can be extracted with hot n-'heptane 2 wt. %.

Example 2

7.4 kg of the carrier, prepared as described in example 1, is suspended in 150 l of n-decane in a 300 l capacity mixing reactor. Add 21 kg of titanium tetra n-butylate and heat the suspension for 30 minutes at 50°C. After cooling to room temperature, slowly add for approx. 26.5 kg of diethyl aluminum chloride for 60 minutes, then heat for 60 minutes at 50°C and finally cool the suspension and remove by filtering 22 kg of the solid catalyst ingredient, wash the ingredient with approx. 50 l of n-decane.

This catalyst ingredient contains in mass. %:

titanium: 12.4, magnesium: 6.8, aluminum: 2.8, chlorine: 40.3, organic part: 37.6.

The catalyst composition can be presented with the following formula:

Ti1 Mg1.08 Al0.42 Cl4.4 (Et + OEt + OBu)1.9,

where OEt and OBu are present in the amount of 6.0 wt. % and 25 wt. % catalyst ingredient.

Other properties are similar to the properties of the solid component of the catalyst from example 1. For the polymerization of ethylene, we use two consecutive reactors with a capacity of 40 m3,

The operating conditions are as follows:

- supplying ethylene 2400 kg/h per reactor

- reactor temperature: 90±1°C

- total pressure in the reactors: 9.8±0.49 bar

- turbidity concentration in reactors: 400 g/l

- hydrogen, which circulates in the reactors: 40 to 41% by volume

- ethylene/hydrogen ratio: 1/1 to 1.1/1

- inflow of fresh supplementary peptane: 1000 kg/h per reactor

- introducing the solid catalyst component

(undiluted): 90 g/h per reactor

- supply of triethyl aluminum (undiluted): 0.6 kg/h to the reactor

- inflow of recycled heptane: 3500 kg/h per reactor

- retention time: about 5 hours.

If we work in the conditions described above, we achieve values of productivity = 27 and profit = 220, expressed similarly to example 1.

Polyethylene thus obtained has the following properties:

melting index 6 to 7 g/103

shear sensitivity 26.5 to 27.5

density 0.9616 to 0.9618 g/ml

physical form of the polymer: loose granules, average diameter 360 μm

apparent density: 0.38 to 0.40 g/ml

content of fine particles (<74, μm) 1 wt. %

IZOD (repulsive elasticity) 10 to 11.5 kg cm/cm2

(ASTM D 256) (about 90 Joule/m) (in addition, the GPC provisions provide the following information:

Mw. 10-3 = 63 - 78

Mn. 10-3 = 18 - 16

Mz. 10-3 = 156 - 283

Mw/Mn = 3.5 - 4.8

Example 3

245 g of the carrier, obtained in example 1, is suspended in 50 ml of n-decane in a mixing reactor with a capacity of 250 ml. Add 7 g of titanium tetra n-butylate and heat the suspension for 120 minutes at 80°C. Then cool to 50°C and dropwise add 5.7 g of ethyl aluminum sesquichloride, diluted in 30 g of n-decane. In this example, we are working with the atomic ratio Mg/Ti=1/1 and with the ratio between chlorine atoms in ethyl aluminum sesquichloride and alkoxy groups = 0.75/1. The suspension is kept for 120 minutes at 50°C and the solid substance is separated by filtration on a sintered glass filter. The solid is washed with three portions of 100 ml of n-decane each.

We obtain 8 g of solid catalyst component, which has the following properties:

- shape and size of the particle: similar to that of the carrier,

- titanium content: 12.0 wt. % expressed as metal,

- the relationship between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent states:

0.85/1,

- specific area 24 m2/g,

porosity: 68 vol.%.

Such a catalyst ingredient contains in mass. %:

titanium: 12, magnesium: 8.7, aluminum: 3.1, chlorine: 45, organic part: 42.

That's why we can define the catalyst ingredient with the following formula:

Ti1Mg1.4Al0.44Cl4.9(Et + OEt + OBu)2.2,

where OEt and OBu are present in the amount of 8.0 wt. % and 22 wt. % catalyst ingredient.

1820 ml of anhydrous n-heptane, 0.68 g of triethyl aluminum and 33 mg of the solid catalyst component, prepared as described above, are successively introduced into a 5-liter mixing reactor.

Heat the reactor to 90°C and add hydrogen at 3.82 bar. Then we introduce ethylene up to a total pressure of 8.8 bar and maintain these conditions for the next 4 hours with the addition of ethylene.

Then we stop the polymerization by injecting 20 ml of IONOL alcoholic solution into the reactor.

The productivity of polyethylene is 15.7 and the gain is 130. The resulting polyethylene has the following properties:

melting index 6.4 g/10'

shear sensitivity 26.8

Mw/Mn 4.0

density 0.9620 g/ml

physical form of the polymer: loose granules, average diameter 360 μm

apparent density: 0.32 g/ml

content of fine particles (<74 μm) 0.3 wt. %.

Example 4

(comparing)

Let's use a carrier, prepared as described in example 1.

2.45 g of this carrier is suspended in 50 ml of n-decane in a 250 ml mixing reactor. Add 7 g of titanium tetra n-butylate to the resulting suspension and heat for 60 minutes at 80°C. Then cool to 30°C and dropwise add 4.2 g of ethyl aluminum dichloride, diluted in 25 g of n-decane. In this example, we are working with the atomic ratio Mg/Ti = 1/1 and with the ratio between chlorine atoms in diethyl aluminum chloride and alkoxide groups = 0.75/1.

The obtained suspension is heated for 120 minutes at 80°C and the solid substance is then filtered on a plate made of sintered glass and washed with three portions of 100 ml of n-decane each.

Thus, we obtain a solid catalyst component (about 3 g), which has the following properties:

- shape and size of particles: heterogeneous dust,

- titanium content: 6.1 wt. %, expressed as metal,

- the relationship between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent states:

0.48/1,

Such a catalyst ingredient contains in mass. %:

titanium 6.1, magnesium: 15.9, aluminum: 2.4, chlorine: 48.4, organic part: 27.

The catalyst composition can be defined with the following formula:

Ti1Mg5.2Al0.7Cl10.7(Et + OEt + OBu)4.7

1820 ml of anhydrous n-heptane, 0.68 g of triethyl aluminum and 6.5 mg of the solid catalyst component described above are successively introduced into the mixing reactor with a capacity of 5 l.

We raise the temperature in the reactor to 90°C, add hydrogen up to 3.72 bar and then ethylene up to 8.8 bar. Ethylene is introduced for another 4 hours, keeping the pressure at the indicated value, then stopping the reaction by injecting 20 ml of IONOL alcoholic solution into the reactor.

The productivity of polyethylene is 9.6 and the profit is 115.

Polyethylene thus obtained has the following properties:

melting index

shear sensitivity 33

density 0.9605 g/ml

physical form of the polymer: heterogeneous dust, average diameter 150 μm

apparent density 0.39 g/ml

content of fine particles (<74 μm) 12 wt. %

Example 5

(comparing)

Let's use a carrier, prepared as described in example 1.

24.5 g of this carrier is suspended in 50 ml of n-decane in a 250 ml mixing reactor. Add 18 g of titanium tetra n-butylate and heat for 60 minutes at 80°C. After cooling to 40°C, add dropwise 13.2 g of ethyl aluminum sesquichloride, diluted in 50 g of n-decane. In this example, we are working with an atomic ratio of Mg/Ti = 0.4/1 and with a ratio between chlorine atoms in ethyl aluminum sesquichloride and alkoxy groups of 0.75/1. The suspension is heated for 120 minutes at 60°C, the solid substance is filtered on a plate made of sintered glass and the solid substance thus obtained is washed with three portions of 100 ml of n-decane.

Thus, we obtain a solid component of the catalyst (16.7 g), which has the following properties:

- shape and size of particles: fine dust, which is difficult to decant,

- titanium content: 15 wt. %, expressed as metal,

- the ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent states: 0.95/1.

Such a catalyst ingredient contains in mass. %:

titanium: 15, magnesium: 3.3, aluminum: 2.4, chlorine: 27.3, organic part: 51.9.

The catalyst composition can be defined with the following formula:

Ti1Mg0.44Al0.3Cl2.5(Et + OEt + OBu)2.3

We introduce 1820 ml of anhydrous n-heptane, 0.68 g of triethyl aluminum and 40 mg of the solid catalyst component described above into a 5 l mixing reactor.

We raise the temperature in the reactor to 90°C, add hydrogen up to 3.7 bar and then ethylene up to 8.8 bar. Ethylene is introduced for another 4 hours, keeping the pressure at the specified value, then the reaction is stopped by injecting 20 ml of IONOL alcoholic solution into the reactor.

Productivity is 15 and profit is 100.

Polyethylene thus obtained has the following properties:

melting index 6.2 g/10'

shear sensitivity 26

density 0.9623 g/ml

physical form of the polymer: heterogeneous dust with an average diameter of 160 μm

apparent density 0.38 g/ml

content of fine particles (<74 μm) 6 wt. %

Example 6

Let's use a carrier, prepared as described in example 1.

2.45 g of this carrier is suspended in 50 ml of n-decane in a 250 ml mixing reactor. Add 14 g of titanium tetra n-butylate and heat for 60 minutes at 80°C. Then cool to 30°C and drop by drop add 15.6 g of diethyl aluminum chloride, diluted in 50 g of n-decane. In this example, we are working with an atomic ratio of Mg/Ti = 0.5/1 and with a ratio between chlorine atoms in diethyl aluminum chloride and alkoxy groups of 0.75/1. Heat for 120 minutes at 60°C, remove the solid by filtering on a sintered glass plate and wash the solid with three portions of 100 ml of n-decane. Thus, we obtain a solid component of the catalyst (13.5 g), which has the following properties:

- shape and size of the particle: similar to the carrier,

- titanium content: 14 wt. %, expressed as metal,

- the ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent states: 0.97/1,

- specific area: 18 m2/year

- porosity: 40% by volume.

Such a catalyst ingredient: contains in mass. %:

titanium: 14.2, magnesium: 3.7, aluminum: 3.3, chlorine: 34, organic part: 45.

The catalyst composition can be defined with the following formula:

Ti1Mg0.5Al0.4Cl3.2(Et + OEt + OBu)2.1

1820 ml of anhydrous n-heptane, 0.68 g of triethyl aluminum and 31 mg of the above-described solid catalyst ingredient are successively placed in a 5 l mixing reactor.

Raise the temperature in the reactor to 90°C, add nitrogen up to 3.5 bar and then ethylene up to 8.8 bar. Ethylene is added for another 4 hours, while keeping the pressure at the indicated value, then the reaction is stopped by injecting 20 ml of IONOL alcoholic solution into the reactor.

Productivity is 18 and profit is 130.

Polyethylene thus obtained has the following properties:

melting index 4.9 g/10'

shear sensitivity 29.6

density 0.9618 g/ml

physical form of the polymer: loose dust with a mean diameter of 180 μm

apparent density 0.39 g/ml

content of fine particles (<74 μm) 6 wt. %.

Example 7

Let's use a carrier, prepared as described in example 1.

10 g of this carrier is suspended in 150 ml of n-decane in a 150 ml mixing reactor. Add 9.7 g of titanium tetra n-butylate and heat for 60 minutes at 50°C. Then cool to 30°C and dropwise add 14.4 g of diethyl aluminum chloride to 50 g of n-decane.

In this example, we are working with the atomic ratio of Mg/Ti=3 and with the ratio between the chlorine atoms in diethyl aluminum chloride and the alkoxy groups of 0.75/1.

Heat for 120 minutes at 50°C, filter the solid substance on a plate made of sintered glass and wash the solid substance with three portions of 100 ml of n-decane.

Thus, we obtain a solid component of the catalyst (16.8 g), which has the following properties:

- shape and size of the particle: similar to the carrier,

- titanium content: 8.1 wt. %, expressed as metal,

- the ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent state: 0.95/1,

- specific surface: 23 m2/g,

- porosity: 38 vol, %,

Such a catalyst ingredient contains in mass %:

titanium: 8.1, magnesium: 12.7, aluminum: 2.9, chlorine: 48.9, organic part: 29.

The catalyst composition can be defined with the following formula:

Ti1Mg3.1Al0.63Cl8.1 (Et + OEt + OBu)3

1820 ml of anhydrous n-heptane, 0.68 g of triethyl aluminum and 37 mg of the aforementioned catalyst ingredient are successively introduced into a 5 l mixing reactor:

We raise the temperature in the reactor to 90°C, add hydrogen up to 3.7 bar and then ethylene up to 8.8 bar. We introduce ethylene for another 4 hours, keeping the pressure at the indicated value, then stopping the reaction by injecting 20 ml of IONOL alcohol solution into the reactor.

Productivity is 14 and profit is 176.

The polyethylene thus obtained shows the following properties:

melting index 4.2 g/10'

shear sensitivity 27

density 0.9611 g/ml

physical form of the polymer: loose dust with an average diameter of 220 μm

apparent density 0.4 g/ml

content of fine particles (<74 μm) 6 wt. %.

Example 8

(comparing)

Let's use a carrier, prepared as described in example 1.

10 g of this carrier is suspended in 150 ml of n-decane in a 500 ml mixing reactor. Add 1.92 g of titanium tetra n-butylate and heat for 60 minutes at 50°C. After cooling to 30°C, add dropwise 6.6 g of diethyl aluminum chloride, diluted in 30 g of n-decane. That is why in this example we are working with the atomic ratio Mg/Ti = 15 and with the ratio between chlorine atoms in diethyl aluminum chloride and alkoxy groups: 0.75/1. Heat for 120 minutes at 50°C, remove the solid substance by filtering on a sintered glass plate and wash the solid substance with three portions of 100 ml of n-decane.

Thus, we obtain a solid component of the catalyst (11.9 g), which has the following properties:

- shape and size of the particle: similar to the carrier,

- titanium content: 2.3 wt. %, expressed as metal,

- the ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent states: 0.93/1.

Such a catalyst ingredient contains in mass. %:

titanium: 2.3, magnesium: 18.9, aluminum: 2, chlorine: 57.2, organic part: 19.6.

The catalyst composition can be defined with the following formula:

Ti1Mg16.6Al1.54Cl34(Et + OEt + OBu)7.8

1820 ml of anhydrous n-heptane, 0.68 g of triethyl aluminum and 133 mg of the above-mentioned solid catalyst ingredient are successively introduced into a 5 l mixing reactor.

We raise the temperature in the reactor to 90°C, add hydrogen up to 3.7 bar and then ethylene up to 8.8 bar. We introduce ethylene for another 4 hours, while maintaining the pressure at the indicated value, then stop the reaction by injecting 20 ml of the alcoholic IONOL solution.

Productivity is 7 and profit is 310.

Polyethylene prepared in this way has the following properties:

melting index 4.3 g/10'

shear sensitivity 29.6

density 0.9623 g/ml

physical form of the polymer: loose dust with an average diameter of 280 μm

apparent density 0.38 g/ml

content of fine particles (<74 μm) 10.6 wt. %.

Example 9

(comparing)

Let's prepare the carrier, we work similarly as in example 1, only to regulate the spray drying conditions so that the alcohol hydroxyl content is 10 wt. %, expressed as ethanol.

5 g of this carrier is suspended in 100 g of n-decane, which contains 5 ml of titanium tetrachloride. Heat for 2 hours at 115°C, cool, remove the solid by filtration and wash the solid with n-decane.

Thus, we obtain a solid component of the catalyst, which has the following properties:

- shape and size of the particle: similar to the carrier,

- titanium content: 2.4 wt.%, expressed as metal.

Such a catalyst ingredient contains in mass. %:

titanium: 2.4, magnesium: 23.6, chlorine: 70, organic part: 4.0.

The catalyst composition can be defined with the following formula:

Ti1Mg19.6Cl39.5(EtO)1.8

1820 ml of anhydrous n-heptane, 0.68 g of triethyl aluminum and 37 mg of the above catalyst ingredient are introduced into a 5 l mixing reactor.

We raise the temperature in the reactor to 90°C, add hydrogen up to 4.5 bar and then ethylene up to 8.8 bar. Ethylene is introduced for another 4 hours, maintaining the pressure at the indicated value, then stopping the reaction by injecting 20 ml of IONOL alcohol solution.

Productivity: 12.8 and gain: 400.

Polyethylene thus obtained has the following properties:

melting index 7.6 g/10,

shear sensitivity 30

density 0.9650 g/ml

physical form of the polymer: loose grains with an average diameter of approx. 400 μm

apparent density 0.32 g/ml

content of fine particles (<74 μm) 3 wt. %

fraction that can be extracted with hot n-heptane 3.2 wt, %.

In addition, the provisions of the GPC provide the following information:

Mw. 10-3 = 88

Mn. 10-3 = 13

Mz. 10-3 = 460

Mw/Mn = 6.8

Example 10

(comparing)

1.9 g of commercial magnesium chloride with a water content of 0.7 wt. % in the form of flakes with a diameter of 0.1 to 2 mm (used in example 1), suspended in 50 ml of n-decane in a 250 ml mixing reactor.

At room temperature (20 to 25°C) add 0.6 g of ethyl alcohol (25 wt. %) and 7 g of titanium tetra n-butylate.

The mixture is heated to 80°C for 60 minutes. Cool to 30°C and slowly add 8.3 g of diethyl aluminum chloride, diluted in 35 g of n-decane.

In this example, we are working with the atomic ratio Mg/Ti = 1/1 and with the ratio between the chlorine atoms in diethyl aluminum chloride and the alkoxy groups: 0.75/1.

The mixture is heated for 30 minutes at 60°C and then filtered through a sintered glass filter, the solid substance is washed with three portions of 100 ml of n-decane. Thus, we obtain 6.5 g of solid catalyst component, which has the following properties:

- shape and size of particles: heterogeneous dust,

- titanium content: 15.5 wt. %, expressed as metal,

- the ratio between titanium in the trivalent state and in the tetravalent state: about 1/1.

Such a catalyst ingredient contains in mass. %:

titanium: 15.5, magnesium: 5.7, aluminum: 1.2, chlorine: 36.4, organic part: 41.

The catalyst composition can be defined with the formula:

Ti1Mg0.74Al0.14Cl3.16 (Et + OEt + OBu)1.74

1820 ml of anhydrous n-heptane, 0.68 g of triethyl aluminum and 22 mg of the solid catalyst component, prepared as described above, are successively introduced into a 5 L mixing reactor.

We raise the temperature in the reactor to 90°C and add hydrogen at 3.7 bar and raise the pressure with ethylene to a total value of 8.8 bar.

We carry out the polymerization for 4 hours, during which we introduce ethylene, then stop the reaction by injecting 20 ml of the alcoholic IONOL solution.

Productivity is 10 and the yield of polyethylene produced is 65.

Such polyethylene has the following properties:

melting index 5.0 g/10'

shear sensitivity 27.3

density 0.9630

physical form of the polymer: heterogeneous dust with an average particle size of about 140 μm

apparent density 0.38 g/ml

content of fine particles (<74 μm) 20 wt. %.

Claims (11)

1. Catalyst component for the polymerization of ethylene or for the copolymerization of ethylene with alpha-olefin, characterized by the fact that it is in the form of solid spherical grains with at least 80% of the grains in the size of 30 to 40 μm, with a specific surface area of 15 to 30 m2/g and with with a porosity of 40 to 80 vol.%, and that we can define it with the formula (in atomic ratios): Ti1Mg0.3-3.1Al0.4-0.65Cl3.2-8.2 (Et + OEt + OR')1,9-3 where Et means an ethyl group, OEt means an ethoxy group and OR' means an alkoxy group with 1 to 8 carbon atoms in an unbranched or branched alkyl part, and in which the ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent state is in the range of 0.8/1 to 1/1. 2. Catalyst composition according to claim 1, indicated by the fact that it has a specific surface area of the order of 20 to 30 m2/g, porosity of the order of 60 to 70 vol.%, and that it can be defined with the formula (in atomic ratios): Ti1Mg0.95-1.5Al0.42-0.46Cl3.9-4.9 (Et + OEt + OR') 1.9-2.3 where Et and OEt have the meaning specified in claim 1, and OR' means an n-butoxy group, the ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent state varies from 0.9/1 to 1/1. 3. Catalyst composition according to claims 1 and 2, characterized in that in the organic part (Et + OEt + OR') OEt and OR' are present in an amount of 5 to 10 wt. % or 20 to 30 wt. % with respect to the solid component of the catalyst. 4. Process for the preparation of the catalyst ingredient according to claims 1 to 3, characterized in that a) spray dry the ethanol solution of magnesium chloride so that a solid, granular, round and loose carrier is formed, which contains from 18 to 25 wt. % of alcoholic hydroxyls, expressed as ethanol, b) we suspend that carrier in an inert liquid and put it in contact and first exchange substances with - titanium tetra alkoxide Ti(OR')4, where R' means an unbranched or branched alkyl group, containing from 1 to 8 carbon atoms, in this case we work at a temperature between room temperature (20 to 25°C) and 90°C, and with the atomic ratio between magnesium in magnesium chloride and titanium in titanium tetraalkoxide from 0.5/1 to 3/1 and then - with diethyl aluminum chloride or ethyl aluminum sesquichloride, in this case we work at a temperature between room temperature (20 to 25°C) and 80°C with the relationship between chlorine atoms in diethyl aluminum chloride or ethyl aluminum sesquichloride and alkoxy groups, which originate from titanium tetraalkoxide and from ethanol, in the range from 0.5/1 to 1.5/1, to obtain a solid component of the catalyst, in which the ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent state is in the range of 0.8/ 1 to 1/1 i c) separate the solid component of the catalyst from the appropriate suspension. 5. The method according to claim 4, indicated by the fact that the carrier is in the form of round particles with approx. 80% of particles with a size of 30 to 40 μm and with a content of alcoholic hydroxyls of 23 to 25 wt. %, expressed as ethanol. 6. The method according to claim 4, characterized in that we add titanium tetraalkoxide to the carrier suspension, in this case we work at a temperature of 30 to 60°C, with an atomic ratio between magnesium in magnesium chloride and titanium in titanium tetraalkoxide from 0.8/1 to 1.5/1 and then we add diethyl aluminum chloride or ethyl aluminum sesquichloride and work at a temperature of 30 to 60°C with the atomic relationship between chlorine atoms in diethyl aluminum chloride or ethyl aluminum sesquichloride and alkoxy groups, which originate from titanium tetra alkoxide and from ethanol, in the range of 0.65/1 to 0.8/1, to obtain a ratio between titanium in the trivalent state and the sum of titanium in the trivalent and tetravalent state in the catalyst composition of 0.9/1 to 1/1. 7. The method according to claim 4, characterized in that the titanium tetraalkoxide is titanium tetra n-butoxide. 8. Catalyst for the polymerization of ethylene, and for the copolymerization of ethylene with alpha-olefin, which contains the catalyst ingredient according to claims 1 to 3, characterized in that the trialkyl aluminum contains from 2 to 6 carbon atoms in the alkyl radical. 9. Catalyst according to claim 8, characterized in that it is trialkyl aluminum, triethyl aluminum. 10. Catalyst according to claim 8, characterized in that we maintain the atomic ratio between aluminum in trialkyl aluminum and titanium in the solid component of the catalyst in the range from 50/1 to 200/1. 11. Catalyst according to claim 10, characterized in that the aluminum/titanium ratio is of the order of 100/1.