RU2320673C2 - Polymerization catalyst prepared by spraying drying and method for polymerization using this catalyst - Google Patents

Abstract

FIELD: catalysts, chemical technology.

SUBSTANCE: invention elates to catalytic compositions, methods for preparing such compositions, and to methods for preparing polymers based on thereof. Invention describes a composition of a spraying drying catalyst precursor and a method for preparing a spraying drying catalyst precursor wherein this composition comprises inert filling agent, magnesium, transient metal, solvent and one electron-donor compound. The composition of catalyst precursor doesn't contain practically other electron-donor compounds and the molar ratio of electron-donor compound to magnesium = 1.9 or less, and the composition comprises particles with particles size from about 10 mcm to about 200 mcm. Also, invention describes catalysts prepared from spraying drying catalyst precursors, and methods for polymerization using such catalysts. Invention provides the improved output and catalytic activity of catalyst.

EFFECT: improved properties of catalyst, improved method of polymerization.

29 cl, 4 tbl, 4 dwg, 5 ex

Description

FIELD OF THE INVENTION

The present invention relates to catalytic compositions, methods for producing such compositions and methods for producing polymers based on them.

BACKGROUND OF THE INVENTION

The properties of the polymers depend on the properties of the catalyst used in their preparation. It is important for the catalyst to adjust the shape, size and size distribution of the catalyst particles in order to be sure of good and suitable for industrial applications performance. This is especially important in gas phase and slurry polymerisation processes. For example, in order to obtain copolymer granules with a size of 1000 μm, the size of the generally preferred catalyst particles for use in polymerization is from about 10 to about 50 microns. The catalyst must have good mechanical properties to withstand wear during the polymerization, as well as to ensure good bulk density of the resulting polymer. One of the important aspects in the development of the polymerization catalyst is, therefore, to provide a catalyst and a method for producing a catalyst that allows you to adjust and adjust the structure and size of the catalyst particles and the particle size distribution. The preparation of such catalysts must necessarily remain a simple process.

Spray drying is one of the methods for producing catalyst particles, which allows you to control the size and shape of the resulting catalysts. When spray drying, liquid droplets containing dissolved and / or suspended materials are ejected from the grinder or nozzle. The solvent evaporates and a solid residue remains. The size and shape of the resulting particles depend on the characteristics of the droplets formed during the spraying process. The structural organization of particles can be affected by changing the volume and size of droplets. Depending on the conditions of the spray drying process, large, small, or aggregated particles can be obtained. Depending on the conditions, it is also possible to obtain particles that are uniform in composition, or mixtures of solution components. The use of inert fillers in spray drying can help control the shape and composition of the particles.

Numerous spray drying catalysts for the polymerization of olefins containing magnesium and titanium, and production methods using such catalysts are described in the literature. However, the magnesium content in such methods is limited by the solubility of magnesium in the solvent. In general, solubility is expected to increase with temperature. However, the solubility of magnesium halides in some preferred organic solvents, such as tetrahydrofuran (THF), in which magnesium-containing components are dissolved, actually decreases from about room temperature to the boiling point of such solvents. It is believed that a decrease in solubility occurs due to the formation of polymer complexes of magnesium halide with a solvent having a lower solubility, such as MgCl ₂ (THF) _1.5-2 . For example, the maximum concentration of ultrapure magnesium chloride that can be achieved in THF is less than about 0.75 mol MgCl ₂ / L. At a temperature of about 60 ° C, near the boiling point of THF, the solubility of magnesium chloride decreases markedly, to less than 0.5 mol / L. However, if commercial grade magnesium chloride is used, its maximum solubility in THF is reduced to about 0.6 mol MgCl ₂ / L. The solubility of magnesium chloride in solutions obtained from commercial grade magnesium chloride at 60 ° C. is only about 0.35 mol / L.

The low solubility of magnesium in the solvent limits the amount and distribution of magnesium halide that can be introduced into the particles of the spray drying catalyst. However, high concentrations of magnesium in the spray-dried particles provide catalysts that make it possible to obtain polymers with more desirable properties and have increased catalytic activity; therefore, increase the relevance and economic efficiency of the catalysts. Thus, it is desirable to provide a spray drying catalyst that has an increased magnesium content.

Summary of the invention

Turning to the needs described above, in one advantageous embodiment of the present invention, there is provided a catalyst precursor composition comprising (1) a mixture of a reaction product of a magnesium halide, a solvent, and an electron-donor compound; and (2) an inert filler. The transition metal in the transition metal compound is selected from transition metals of groups 3-10 and lanthanides. The catalyst precursor composition is substantially free of other electron-donor compounds, and the molar ratio of the electron-donor compound to magnesium is less than or equal to 1.9. Catalyst precursor compositions also include spherical or substantially spherical particles having an average particle size of greater than about 10 microns.

In addition, methods for preparing catalyst precursor compositions are included in the present invention. Such methods include (1) providing a mixture of a reaction product of a magnesium halide, a solvent, an electron-donor compound and a transition metal compound; (2) contacting the mixture or reaction product with an inert filler to form a suspension; (3) spray drying the suspension. The transition metal compound can be selected from transition metal compounds containing a transition metal of groups 3-10 and lanthanides. In these methods, the catalyst precursor compositions are substantially free of other electron-donor compounds, and the molar ratio of the electron-donor composition to magnesium is less than or equal to 1.9. Catalyst precursor compositions also include spherical or substantially spherical particles having an average particle size of greater than about 10 microns.

In another aspect, the invention includes catalyst compositions which comprise a product (1) a mixture of a reaction product of a magnesium halide, a solvent, an electron-donor compound; a transition metal compound, and an inert filler; and (2) a co-catalyst composition. The catalyst composition is substantially free of other electron-donor compounds, and the molar ratio of the electron-donor compound to magnesium is less than or equal to 1.9, the catalyst composition comprising spherical or substantially spherical particles having an average particle size of greater than about 10 microns.

In yet another aspect, methods for producing polymers comprising the reaction of at least one polyolefin monomer in the presence of such catalyst compositions are also included in the present invention.

In some preferred embodiments, the catalyst precursor composition or catalyst composition comprises particles in which the ratio of magnesium to titanium is greater than about 5: 1. In other preferred embodiments, the ratio of magnesium to titanium is from about 6: 1 to about 10: 1.

In some preferred embodiments, the particles of the catalyst precursor composition or catalyst compositions have a particle size distribution such that 10% by weight of the particles are particles smaller than about 15 microns. In other preferred embodiments, 90% by weight of the particles are particles of sizes from less than about 40 to about 70 microns. In some preferred embodiments, the particles are substantially spherical and have a distribution span of from about 1 to about 2.5. In some particularly preferred embodiments, the particles are not agglomerated and have a particle size distribution in which 50% by weight of the particles have sizes from less than about 20 to about 35 microns. Some preferred catalyst compositions described herein have an average particle size of from about 10 to about 60 microns and a span of distribution from about 1.5 to about 2.0.

In some preferred embodiments, the electron donor is an electron donor that includes a linear or branched aliphatic or aromatic alcohol containing from one to about 25 carbon atoms. Preferred alcohols include methanol, ethanol, propanol, iso-propanol, butanol, 2-ethylhexanol, 1-dodecanol, cyclohexanol and tert-butylphenol. In some preferred embodiments, the molar ratio of alcohol to magnesium is less than about 1.75. In other preferred embodiments, the molar ratio of alcohol to magnesium is from about 0.1 to about 1.1. In still some preferred embodiments, the molar ratio of alcohol to magnesium is from about 0.1 to about 0.5.

Preferred transition metal compounds suitable for the preferred embodiments of the compositions and methods described herein include titanium, zirconium, hafnium, vanadium, niobium, tantalum compounds, or combinations thereof. Some titanium compounds are described by the formula:

Ti (R) _a X _b ,

where R represents R 'or COR', where R 'represents a C ₁ -C ₁₄ aliphatic or aromatic hydrocarbon radical, X is selected from Cl, Br, I, or mixtures thereof, and is 0 or 1, b is from 2 to 4 inclusive, a + b = 3 or 4. Examples of titanium compounds include TiCl ₃ , TiCl ₄ , Ti (OC ₆ H ₅ ) Cl ₃ , Ti (OCOCH ₃ ) Cl ₃ , Ti (OCOC ₆ H ₅ ) Cl ₃ , or mixtures thereof.

The solvent is selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids, ethers, and aliphatic ketones. Preferred alkyl ester solvents include, but are not limited to, methyl acetate, ethyl acetate, ethyl propionate, methyl propionate, ethyl benzoate, and combinations thereof.

Preferred ethers include diethyl ether, diisopropyl ether and di-n-butyl ether, ethyl isopropyl ether, methyl butyl ether, metalallyl ether, ethyl vinyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and combinations thereof. In some preferred embodiments, tetrahydrofuran is preferred. Typical ketone solvents include acetone, methyl ethyl ketone, cyclohexanone, cyclopentyl methyl ketone, 3-bromo-4-heptanone, 2-chlorocyclopentanone, allyl methyl ketone, and combinations thereof. Some preferred options include two or more such solvents.

Magnesium halides for use in the compositions included herein include, but are not limited to, MgCl ₂ , MgBr ₂ , MgI ₂ , MgClBr, MgBrI, or mixtures thereof. In some preferred embodiments, such halides can be used to prepare catalyst precursor compositions and catalytic compositions that include compositions of the formula:

[Mg (ROH) _r ] _m Ti (OR) _n X _p [S] _q ,

where ROH includes a linear or branched alcohol containing from one to about 25 carbon atoms, R represents R 'or COR', where each R 'individually represents an aliphatic hydrocarbon radical containing from one to about 14 carbon atoms, or an aromatic hydrocarbon a radical containing from one to about 14 carbon atoms; X is individually Cl, Br or I; S is selected from the group consisting of alkyl esters, aliphatic ethers, cyclic ethers, and aliphatic ketones; m is from 0.5 to 56; n is 0, 1 or 2; p is from 4 to 116; q is from 2 to 85; g is from 0.1 to 1.9. In some preferred embodiments, g is from 0.1 to less than about 0.5.

In some preferred embodiments, the compositions herein further comprise a mixture or reaction product of a Lewis acid with a catalyst precursor composition or a catalytic composition. Some suitable Lewis acids correspond to the formula R _g MX _3-g , where R is R 'or OR' or NR ' ₂ , where R' is a substituted or unsubstituted aliphatic or aromatic hydrocarbyl group containing from 1 to 14 carbon atoms, X selected from the group consisting of Cl, Br, I and mixtures thereof; g is 0-3, and M is aluminum or boron. Typical Lewis acids include tri-n-hexyl aluminum, triethyl aluminum, diethyl aluminum chloride, trimethylaluminum, dimethylaluminum chloride, methylaluminum dichloride, tri-iso-butylaluminum, tri-n-butylaluminum chloride, di-isobutyl aluminum, isobutyl aluminum dichloride, (C ₂ H ₅ ) AlCl ₂ , (C ₂ H ₅ O) AlCl ₂ , (C ₆ H ₅ ) AlCl ₂ , (C ₆ H ₅ ) AlCl ₂ , (C ₆ H ₁₃ O) AlCl ₂ , and combinations thereof. Typical Lewis boron acids include BCl ₃ , BBr ₃ , B (C ₂ H ₅ ) Cl ₂ , B (OC ₂ H ₅ ) Cl ₂ , B (C ₂ H ₅ ) ₂ Cl, B (C ₆ H ₅ ) Cl ₂ , B (OC ₆ H ₅ ) Cl ₂ , B (C ₆ H ₁₃ ) Cl ₂ , B (OC ₆ H ₁₃ ) Cl ₂ and B (OC ₆ H ₅ ) ₂ Cl, and combinations thereof.

Although any co-catalyst may be used, some suitable co-catalysts correspond to the formula AlX ’ _d (R ″) _c H _e , where X ″ is Cl or OR ″, R ″ and R ″ ″ are individually C ₁ -C ₁₄ substituted hydrocarbon radicals, d is 0-1.5, e is 0 or 1; c + d + e = 3. Typical co-catalysts include Al (CH ₃ ) ₃ , Al (C ₂ H ₅ ) ₃ , Al (C ₂ H ₅ ) ₂ Cl, Al (iC ₄ H ₉ ) ₃ , Al (C ₂ H ₅ ) _1.5 C _1.5 , Al (iC ₄ H ₉ ) ₂ H, Al (C ₆ H ₁₃ ) ₃ , Al (C ₈ H ₁₇ ) ₃ , Al (C ₂ H ₅ ) ₂ N, Al (C ₂ H ₅ ) ₂ (OS ₂ H ₅ ), and combinations thereof.

Preferred inert fillers in the present description include silica, titanium dioxide, zinc oxide, magnesium carbonate, magnesium oxide, carbon and calcium carbonate. Usually use one type of filler; however, some preferred options further include a second inert filler. In some preferred embodiments, filler particles or fillers comprise from about 10 to about 95 wt.% Particles of the catalyst composition.

In some particularly preferred embodiments, the transition metal compound comprises Ti, wherein the ratio of co-catalyst to Ti is from about 1 to about 400 mol of co-catalyst per 1 mol of Ti. In other preferred embodiments, a co-catalyst to Ti ratio of from about 15 to about 60 moles of co-catalyst per mole of Ti may be preferred. In still some preferred embodiments, the ratio of co-catalyst to Ti is from about 4 to about 10 moles of activator compound per mole of Ti.

Some of the polymerization methods described herein provide a polymer containing ethylene in an amount that is greater than or equal to about 90% mole., And containing one or more co-monomers in an amount of less than or equal to about 10% mole. Some preferred embodiments of the polymerization processes provide a polymer having a density in the range of 0.88 to about 0.98 g / cm ³ .

Brief Description of the Drawings

Figure 1 shows the solubility features of MgCl ₂ in solutions in THF for the three preferred embodiments of the present invention, that is, the dependence of solubility on alcohol content and solution temperature.

Figure 2 presents the solubility profiles of several preferred variants of the present invention depending on temperature, MgCl ₂ concentration and the alcohol: Mg ratio in THF.

3 shows a fluidized bed reaction system used in preferred embodiments of the catalysts of the present invention.

4A shows a photograph taken by a scanning electron microscope (SEM) of a comparative conventional spray drying catalyst.

FIG. 4B shows a photograph taken by a scanning electron microscope (SEM) of one of the typical preferred embodiments of the catalyst of the present invention.

Description of preferred embodiments of the present invention

Preferred embodiments of the present invention provide a spray dried catalyst precursor composition and a method for preparing a spray dried catalyst precursor composition with an inert filler, magnesium, a transition metal, a solvent and one electron donor compound. The catalyst precursor composition is substantially free of other electron-donor compounds, the molar ratio of electron-donor compound to magnesium is less than or equal to 1.9, and it includes spherical or almost spherical particles having a particle size of from about 10 to about 200 microns.

In one preferred embodiment, a method for producing such catalyst precursor compositions comprises forming a solid precursor composition from an inert filler, magnesium, transition metal; solvent; and one electron-donor compound by forming a suspension of a solution of a magnesium compound, an electron-donor compound, and a transition metal compound in a solvent containing an inert filler. The mixture is spray dried by breaking into fine particles to obtain particles having a usable particle size distribution. Catalysts can be prepared by contacting the catalyst precursor composition with a co-catalyst. The catalyst precursor composition or catalytic composition is optionally modified with a Lewis acid and / or alkylating agent.

In the following description, all numbers given in the description are approximate values, regardless of whether or not the words “about” or “approximately” are used in connection with them. They can vary by values up to 1.2, 5%, or sometimes 10-20%. When a numerical range having a lower limit, R _L , and an upper limit of R _{U is used} , any number R falling within this range is specifically included in the description. Specifically, the following R numbers within the interval are specifically included in it: R = R _L + k · (R _U -R _L ), where k is a variable varying from 1 to 100%, with an increment of 1%, i.e. k 1%, 2%, 3%, 4%, 5%, ..., 50%, 51%, 52%, ..., 95%, 96%, 97%, 98%, 99%, or 100 % Moreover, any numerical range defined by two numbers, R, as defined above, is specifically included in the present description.

The expression "practically spherical" in the present description means that the particles have an average characteristic ratio of from about 1.0 to about 2.0. The characteristic ratio is defined in the present description as the ratio of the maximum linear particle size to the minimum linear particle size. The characteristic ratio can be determined from scanning electron microscopy (SEM). Of course, this definition, in accordance with the authors' intention, includes spherical particles, which by definition have a characteristic ratio of 1.0. In some preferred embodiments, the catalyst composition has an average characteristic ratio of about 1.8, 1.6, 1.4, or 1.2.

Any reference in the present description to "electron-donor compounds" means compounds that modify the solubility of magnesium halide in an electron-donor solvent so that the solubility does not decrease within any temperature range, up to the boiling point of the electron-donor solvent. In the present description, the term "electron-donor compounds" does not include "solvents", as defined below, even if such solvents are electron-donor in nature. Typical electron donor compounds include alcohols, thiols, weakly donor amines and phosphines. In the present description, the term "practically does not contain other electron-donor compounds" means that other "electron-donor compounds", as defined in the present description, are not present in concentrations higher than those concentrations that are usually found as impurities in commercial reagents containing such compounds sold for use as solvents. Thus, compositions containing a solvent having electron-donor characteristics and an "electron-donor substance" are considered as "practically free of other electron-donor compounds." In some preferred embodiments, “substantially free” means less than 1, 0.1, 0.01, or 0.001 wt.%.

Suitable solvents include any compound based on an ether, ketone or ester. If such solvents have electron-donor characteristics, any reference herein to “solvent” or “solvents” does not include these compounds, defined above as “electron-donor compounds”. Thus, compositions that "practically do not contain other electron-donor compounds" may include one or more "solvents".

As used herein, the term “ether” is defined as any compound of the formula R — O — R ′, wherein R and R ′ are substituted or unsubstituted hydrocarbyl groups. In some cases, R and R 'are the same. Typical but not limiting the scope of the present invention, symmetric ethers are diethyl ether, di-isopropyl ether and di-n-butyl ether. Typical asymmetric ethers include ethyl isopropyl ether and methyl butyl ether. Examples of suitable substituted ethers include, for example, methylallyl ether and ethyl vinyl ether. In still some preferred embodiments, R and R ′ may form a fused ring, which may be saturated or unsaturated. One example of such a compound is tetrahydrofuran. Another suitable substance from such cyclic ethers is 2-methyltetrahydrofuran. Here again, the specifically listed compounds are given only as examples of kinds of compounds that are suitable, however, any compound having an ester functional group R-O-R 'is suitable for use.

As used herein, the term “ketone” is defined to indicate any compound having the formula R (C = O) R ′. R and R 'may be individually substituted or unsubstituted hydrocarbyl groups, as otherwise described above in relation to ethers. Typical ketones are acetone, methyl ethyl ketone, cyclohexanone, cyclopentyl methyl ketone. You can also use halogenated ketones, such as 3-bromo-4-heptanone, or 2-chlorocyclopentanone. Other suitable ketones may include other functional groups, such as unsaturated groups, as in allyl methyl ketone. Each of these compounds corresponds to the formula R (C = O) R ', where the carbon atom of the carbonyl group in the molecule forms bonds with two other carbon atoms.

Suitable esters include any compound of the general formula R (C = O) OR ′. In such compounds, the carbon atom of the carbonyl group forms one bond with a carbon atom, and another bond with an oxygen atom. R and R 'are individually selected from substituted or unsubstituted hydrocarbyl groups, and they may be the same or different. In some preferred embodiments, the ester includes alkyl esters of aliphatic and aromatic carboxylic acids. Cyclic esters, saturated esters and halogenated esters are also included in this group. Typical but non-limiting esters of the present invention include methyl acetate, ethyl acetate, ethyl propionate, methyl propionate and ethyl benzoate. Here again, the specifically listed compounds are given only as examples of types of compounds suitable for use. Any compound corresponding to the general formula R (C = O) OR ′ is suitable for use in the present invention.

Any suitable solvent can be brought into contact with the magnesium source by directly mixing the magnesium halide with the solvent. In some preferred embodiments, the magnesium halide is magnesium chloride; however, magnesium bromide and magnesium iodide can also be used. Magnesium halides such as MgCl ₂ , MgBr ₂ , MgI ₂ , or mixed magnesium halides, for example MgClI, MgClBr and MgBrI, can be used as sources of halides. In some preferred embodiments, the magnesium halide is added to the solvent in anhydrous form. In other preferred embodiments, the magnesium halide is added in hydrated form.

Typically, the solvent is provided in large excess with respect to the first coordination environment of magnesium. In some preferred embodiments, the ratio of solvent to magnesium is about 100: 1; in other preferred embodiments, the ratio may be even greater. In still some preferred embodiments, the solvent is present in such quantities that per mole of magnesium the following number of moles of solvent is present: from at least about 1.0; at least about 2.0; at least about 5.0, at least about 10, or at least about 20. In some preferred embodiments, two or more solvents may be used.

The electron-donor compound is added to the mixture of solvent and magnesium halide by any suitable method. Preferably, the electron donor compound is directly added to the mixture. The alcohol may be any single chemical compound having the general formula ROH. R may be any single substituted or unsubstituted hydrocarbyl group. In some preferred embodiments, the alcohol is an aliphatic alcohol containing from about 1 to about 25 carbon atoms. In some preferred embodiments, the alcohol is a monodentate alcohol. As used herein, the term “monodentate alcohol” means an alcohol in which R is such a substituent that substitution does not lead to a molecule containing more than one hydroxyl group (OH) that coordinates with the magnesium atom in solution. Typical alcohols may include methanol, ethanol, propanol, iso-propanol and butanol. Alcohols containing a longer chain aliphatic group, for example, 2-ethylhexanol, or 1-dodecanol, also form solutions in which the solubility of magnesium halide increases with temperature. Alcohols containing more carbon atoms can also be used. The alcohol may also be a cyclic alcohol, such as cyclohexanol, or an aromatic alcohol, such as phenol or tert-butylphenol.

In certain preferred embodiments, the ratio of electron donor compound to magnesium halide used is less than or equal to 1.9. In some preferred embodiments, the molar ratio of electron-donor compound to magnesium is less than about 1.75, less than 1.5, less than 1.0, less than 0.75, less than 0.5, less than about 0.4, or less than about 0, 25. In still other preferred embodiments, the molar ratio of electron-donor compound to magnesium is about 0.1. In other preferred embodiments, the molar ratio may be above 1.9, for example, about 2.0, about 2.1, about 2.2, about 2.5, and about 3.0. In general, a certain amount of electron-donor compounds used can bind to other components during the preparation process.

Adding small amounts of one electron-donor compound, the other with respect to the solvent, to mixtures containing a solvent and magnesium halide, gives a magnesium-containing composition whose solubility increases with temperature, and the solubility of which at the boiling point of the solvent is relatively higher than the solubility of the magnesium halide adducts / electron donor in which the electron-donor compound is not present. The solubility is also higher than the solubility of the comparative magnesium halide / electron donor adducts containing additional types of electron-donor compounds. It is believed that the addition of small amounts of one electron donor to a solvent in the presence of magnesium halide inhibits the conversion of soluble particles to polymer adducts. In some preferred embodiments, soluble particles correspond to the formula

MgX _x (ED) _y S _z ,

where x is usually 2, satisfies the oxidative state of magnesium, and y is less than 4, x + y + z is less than or equal to 6. In some preferred embodiments, y is about 0.5, 0.75, 1, 1.5, 1.75 , or 1.9 or less. In some other preferred embodiments, y is about 0.1, 0.25, 0.3, or 0.4. Such particles typically have solubility in a solvent, which increases with increasing temperature to the boiling point of the solvent. If the solvent is THF, the concentration of magnesium halide in the solution can be up to five times higher than in comparative solutions in which the electron-donor compound is absent, especially if the electron-donor compound is an alcohol.

Figure 1 shows the solubility profile of solutions of magnesium chloride in tetrahydrofuran as a function of temperature. As can be seen from figure 1, the composition does not contain alcohol, usually have a solubility of magnesium halide, which increases from about 0.5 mol of magnesium per liter to a maximum value of less than about 0.65 mol of magnesium per liter at about 30 ° C. Above 30 ° C, the solubility gradually decreases until the boiling point of the solvent is reached. Conversely, mixtures in which alcohol, for example ethanol is added, have a solubility of magnesium halide, which does not decrease with increasing temperature up to the boiling point of the solvent. For example, mixtures in which the ratio of ethanol to magnesium is approximately 0.5 exhibit a solubility of magnesium at 15 ° C. of approximately 0.75 mol / L. The solubility of magnesium chloride increases with increasing temperature to about 30 ° C, at which the concentration of magnesium in the solution is about 1.75 mol / L. When the temperature is raised above 30 ° C, the solubility remains almost constant until the boiling point is reached.

Figure 1 also shows the change in solubility of mixtures in which the ratio of alcohol to magnesium is about 1. At 25 ° C, the concentration of magnesium present in the solution is about 0.5 mol / L. However, the concentration rises to about 2 mol / L by the time the temperature reaches about 55 ° C and remains almost constant up to the boiling point of the solvent. Samples containing two moles of alcohol per mole of magnesium also demonstrate that the solubility of magnesium increases with increasing temperature up to the boiling point, at which the value is about 1.75 mol of magnesium per liter.

Figure 2 shows the solubility profile of several mixtures containing various amounts of added alcohol. Each data point in FIG. 2 was obtained by adding the amount of magnesium chloride needed to achieve the desired concentration at which all magnesium chloride was dissolved in THF as an electron donor. A portion of alcohol was then added to obtain the desired alcohol: magnesium ratio, and the mixture was then heated until the composition was dissolved in THF. Then, the solution was slowly cooled until a precipitate began to form. The temperature at which a precipitate began to form was recorded as a value on the y axis in FIG. 2. Thus, figure 2 shows the temperature that is necessary to obtain solutions of magnesium chloride of various concentrations in the presence of alcohol. For example, data series 210 shows the temperatures necessary to reach a solution in which the concentration of magnesium chloride is 0.75 M, where the solvent is THF in the presence of various concentrations of ethanol. In mixtures prepared with an alcohol to magnesium ratio of 0.25, the concentration of magnesium in the solution is approximately 0.75 M only at 5 ° C. Mixtures prepared with an alcohol to magnesium chloride ratio of 0.5 reach a magnesium concentration of 0.75 M at about 15 ° C, while a mixture with a ratio of 1.0 reaches a concentration of 0.75 M at about 33 ° C . If the mixture is prepared so that the ratio of alcohol to magnesium chloride is 1.5 or 2.0 mol., The solutions reach a magnesium concentration of about 0.75 at about 47 and 53 ° C, respectively. Thus, data series 210 indicates that mixtures with higher alcohol: magnesium ratios tend to be less soluble in the solvent.

Thus, figure 2 shows that with lower ratios of alcohol to magnesium chloride, solutions with a higher concentration of dissolved magnesium are obtained. A decrease in solubility with an increase in the ROH / MgCl ₂ ratio implies that small amounts of added ROH prevent the formation of the polymer adduct MgCl ₂ (THF) ₂ , and the addition of more significant quantities of ROH, or additional alcohols, shifts the solution to less soluble adducts containing more ROH. The ROH / Mg ratio used determines the maximum solubility that can be achieved at the desired temperature. The data series 220-260 in FIG. 2 show that for a given alcohol: magnesium ratio an increase in temperature leads to an increase in the amount of soluble magnesium. For example, solutions having a molar alcohol: magnesium molar ratio of 0.5 have a magnesium concentration in the solution of about 0.75 M at about 15 ° C, while at about 20 ° C a magnesium concentration in the solution is achievable, component of 1.0 M. Line 230 shows that at about 23 ° C the same solution can dissolve about 1.25 mol / L of magnesium chloride. Figure 2 also demonstrates that the solubility of magnesium chloride in such solutions also increases for temperatures above 30 ° C. For example, solutions having a molar ratio of alcohol to magnesium of 1 have a solubility of magnesium chloride of about 0.75 M at a temperature of about 35 ° C, while at about 41 ° C the solubility increases to about 1 M. Data, represented by lines 230-260 show that solubility continues to increase until it approaches the boiling point of THF. Solutions with a higher alcohol: magnesium ratio exhibit similar behavior.

The nature of the particles in the solution was determined using a variety of research methods. An NMR study showed that electron donors coordinated with MgCl ₂ in a THF solution are in equilibrium, individual long-lived particles do not exist. The gas phase above a THF solution containing MgCl ₂ and two equivalents of ethanol (EtOH) based on Mg contains significantly less alcohol than the gas phase above the same EtOH / THF solution not containing MgCl ₂ . This suggests that ethanol is captured by MgCl ₂ molecules in solution. Obviously, the alcohol group is coordinated with the center of MgCl ₂ in the solution phase. The maximum solubility at the average alcohol: MgCl ₂ ratios suggests that some particles are present in the solution, the concentration of which depends on the nature of the alcohol, the specific alcohol: Mg ratio and the temperature of the solution.

When forming the catalyst precursor, the magnesium halide solution is contacted with a titanium source. Suitable magnesium precursors are described in related applications of Burkhard E. Wagner, et al., Under the heading "Enhanced Solubility of Magnesium Halides and Catalysts and Polymerization Processes Employing Same", filed July 15, 2002, incorporated herein by reference; "Spray-Dried Polymerization Catalyst and Polymerization Processes Employing Same", filed July 15, 2002, incorporated herein by reference; and "Spray-Dried Polymerization Catalyst and Polymerization Processes Employing Same", filed July 15, 2002, incorporated herein by reference.

Transition metal compounds that are soluble in the solvent can be used as a transition metal source for the catalyst. The amount of transition metal compound or mixture of transition metal compounds used in the preparation of the catalyst precursors can vary widely, depending on the type of catalyst required. In some preferred embodiments, the molar ratio of magnesium to transition metal compound may be high, up to about 56, preferably from about 20 to about 30. In other preferred embodiments, the molar ratio of magnesium to transition metal compound is low, about 0.5. In general, molar ratios of magnesium to transition metal compound of about 3 to about 6 are preferred, with the transition metal being titanium.

However, in some preferred embodiments, the titanium source may not be highly soluble, and in other cases, may be insoluble in the solvent. In still some preferred embodiments, titanium can be supplied as a compound having the general formula Ti (OR) _a X _b , where R is a C ₁ -C ₁₄ aliphatic or aromatic hydrocarbon radical, or COR ', where R' is C ₁ - C ₁₄ aliphatic or aromatic hydrocarbon radical, X is selected from the group consisting of Cl, Br, I, or mixtures thereof, and is 0 or 1, b is from 2 to 4 inclusive, a + b = 3 or 4. Examples of some suitable compounds titanium include, but are not limited to, TiCl ₃ , TiCl ₄ , Ti (OS ₆ H ₅ ) Cl ₃ , Ti (OCOCH ₃ ) Cl ₃ and Ti (OCO ₆ N ₅ ) Cl ₃ . In some preferred embodiments, one titanium compound may be used, while in others, the titanium source may be one or more different titanium containing compounds. Regardless of the source of titanium, it can be added to the magnesium precursor solution mixture in such an amount as to achieve a molar ratio of magnesium to titanium of from about 0.5 to about 1.0, from about 1.0 to about 5.0, from about 5.0 to about 10.0, or from about 10.0 to about 56.

A source of titanium can be added to the reaction mixture at any convenient time. In some preferred embodiments, titanium is added after the magnesium halide and electron-donor compound have been added to the solvent. In some preferred embodiments, the catalyst precursor composition has the formula in accordance with the following general equation:

[Mg (ROH) _r ] _m Ti (OR) _n X _p [S] _q ,

where ROH is a linear or branched alcohol containing from one to about 25 carbon atoms, R is R 'or COR', where each R 'is individually an aliphatic hydrocarbon radical containing from one to about 14 carbon atoms, or aromatic a hydrocarbon radical containing from one to about 14 carbon atoms; X is individually Cl, Br or I. B, the formula S is a solvent selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids, aliphatic ethers, cyclic ethers and aliphatic ketones, m is from 0.5 to 56, n is 0, 1 or 2, p is from 4 to 116, q is from 2 to 85, r is from 0.1 to 1.9. In some preferred embodiments, r in the formula is 0.25, 0.3, 0.4, 0.5, 0.75, 1.0, 1.25, 1.5, or 1.75.

Typically, a solution containing a mixture of the reaction product of a magnesium halide composition and a titanium source is contacted with an inert filler. Suitable fillers are solid, free-flowing compounds or compositions that are inert to other components of the catalyst composition and to other active components of the reaction system. Any solid granular composition that is inert to other components of the catalyst system and does not cause harmful effects on polymerization can be used as a filler in preferred embodiments of the present invention. Such compounds may be organic or inorganic and include, but are not limited to, silicon dioxide, titanium dioxide, zinc oxide, magnesium carbonate, magnesium oxide, carbon and calcium carbonate. In some preferred embodiments, the filler is vaporized hydrophobic silica, which imparts a relatively high viscosity of the suspension and good hardness to the particles obtained by spray drying. In other preferred embodiments, two or more excipients may be used. In some preferred embodiments, the filler has a particle size of from about 0.05 μm to about 1 μm. In other preferred embodiments, the average particle size is about 0.1 microns, about 0.2 microns, about 0.3 microns, or about 0.4 microns. One useful filler is Cabosil ^® , which is supplied by Cabot Corporation. According to the manufacturer, one of Cabosil ^® is an amorphous silica having a maximum residue content of 325 mesh of 0.02% and a bulk density of about 3.0 lb / cubic foot. Crystalline fillers may also be used. In some preferred embodiments, the filler may have a specific surface area of from about 100 to about 300 m ² / g, for example, about 200 m ² / g, about 225 m ² / g, or about 250 m ² / g, as measured by the BET method, as described in article S. Brunauer, P. Emmet, E. Teller in Journal of the American Chemical Society, 60, pp. 209-319 (1939). In other preferred embodiments, the filler may have a specific surface area that is not within the specified range.

The filler must be dry, i.e. not contain absorbed water. Drying of the filler is carried out by heating it at a temperature below the temperature of agglomeration or melting of the carrier material. Typically use temperatures of at least 100 ° C. Lower temperatures may be used if an increase in drying time is acceptable, or if the carrier has a low melting or agglomeration temperature. Inorganic carrier materials are usually dried at a temperature of about 200-800 ° C. In addition, the filler material may optionally be treated with one or more Lewis acid in an amount of 1-8 wt.%, For example, but not limiting the scope of the present invention, an example, alkyl aluminum compounds or Grignard reagents, in order to accelerate the removal of absorbed water. This modification of the filler with acylaluminium compounds also provides a catalytic composition with increased activity and improves the morphology of the polymer particles of the final ethylene polymers.

After preparing the dried filler, it is combined with a catalyst precursor composition or a suspension of a catalyst precursor composition to form a suspension suitable for spray drying. Suitable suspensions include, but are not limited to, those suspensions that include a filler that contains from about 1 to about 95 wt.% The catalyst composition. In some preferred embodiments, the filler comprises about 30, about 40, about 50, or about 60 wt.% Of the catalyst composition. In the spray drying process, such suspensions produce individual catalyst particles in which the filler is present in an amount of from 10 to about 95 wt.% By weight of the catalyst particle. In some preferred embodiments, the filler is about 10-20 wt.% From the mass of the particles of the catalyst obtained by spray drying. In other preferred embodiments, the filler may comprise about 30, about 40, about 50, or about 60 wt.% By weight of the spray dried catalyst particle.

Spray drying can be carried out using any suitable technique. However, the catalysts described herein are not limited to those obtained by spray drying. Typical spray drying techniques are described in US Pat. Nos. 4,293,673 and 4,728,705, both of which are incorporated herein by reference. In preferred embodiments of the invention, spray drying is usually carried out by mixing a solution or suspension of a magnesium complex and a titanium compound with a suitable filler. After mixing the solution or suspension with the filler, the resulting mixture can be heated and further sprayed using a suitable spray device, with the formation of individual particles of approximately spherical shape. Spraying is usually caused by passing the suspension through a nebulizer together with an inert drying gas. To cause spraying, you can use a spray nozzle, or a high speed centrifugal disc. The volumetric flow rate of the drying gas is much higher than the volumetric velocity of the suspension, in order to cause the spraying of the suspension and remove excess electron-donor compounds and other solvents. The drying gas must be non-reactive under spray conditions. Suitable gases include nitrogen and argon. However, you can use another gas, provided that it is not reactive and carries out the required drying of the catalyst. In general, the drying gas is heated to a temperature below the boiling point of the electron donor, or solvent. In some preferred embodiments, the drying gas is heated to a temperature above the boiling point of the electron-donor compound or solvent. In some preferred embodiments, the drying gas is heated to about 200 ° C to accelerate the removal of excess electron donor. If the volumetric flow rate of the drying gas is kept at a very high level, temperatures below the boiling point of the electron-donor compound can be used. In some preferred embodiments, the pressure of the spray nozzle is about 1, about 2, about 5, about 10, about 25, or about 50 psi. inch (rel.). In other preferred embodiments, the spray pressure is about 100, 150, or about 200 psi. inch (rel.). In centrifugal spraying, the diameter of the cam wheel is typically from about 90 to about 180 mm. Wheel speed is selected so as to adjust the particle size. Typical camshaft speeds are from about 8000 to about 24000 rpm, although higher or lower speeds can be used to obtain the desired particle sizes.

Of course, a person skilled in the art will appreciate that the concentration of magnesium in the droplets formed during the spray drying process will be directly related to the amount of magnesium in the particle formed as a result of spray drying.

In some preferred embodiments, the catalyst precursor is obtained as a result of a spray drying process in the form of a fine, free-flowing powder. In some preferred embodiments, the catalyst precursor may have the characteristics of a mixture of crystalline phases, amorphous phases, or have the characteristics of a mixture containing crystalline and amorphous components. The average particle size of the catalyst precursor composition is typically determined by the amount of filler and other curing components, which indicates that, in at least some preferred embodiments, the solubility of magnesium halide is not exceeded. Thus, the higher solubility of magnesium-containing components described in the present description, allows to obtain catalysts and catalyst precursors containing larger amounts of magnesium. In turn, higher amounts of magnesium produce larger particles with higher ratios of magnesium to titanium. In certain preferred embodiments, the ratio of magnesium to titanium is from about 1.5: 1 to about 15: 1. In some preferred embodiments, the ratio is about 2: 1, about 3: 1, about 4: 1, about 5: 1, about 6: 1, or about 10: 1. Other preferred options may have a magnesium to titanium ratio that goes beyond these limits.

In some preferred embodiments, the spray dried catalyst particles have an average particle size of from about 10 to about 200 microns. In some preferred embodiments, the average particle size is about 20 microns, or about 30 microns. In other preferred embodiments, the average particle diameter of the particles obtained by spray drying is about 40 microns, 50 microns, 60 microns, 75 microns, or 90 microns. The average particle size of the catalyst precursor can be determined using commercially available laser diffraction devices, such as the Malvern 2600 ^® particle size analyzer.

Particles obtained by spray drying are also characterized by their particle distribution. In the present description, the expressions "D ₁₀ ", "D ₅₀ " and "D ₉₀ " show the corresponding percentiles of the logarithm of the normal particle size distribution determined using a Malvern 2600 ^® particle size analyzer using hexane as a solvent. So, particles for which D ₅₀ is 12 have an average particle size of 12 microns. D _{90 of} 18 indicates that 90% of the particles have a particle size of less than 18 microns, and D ₁₀ of 8 indicates that 10% of the particles have a particle size of less than 8 microns. In some preferred embodiments, the spray dried particles have a D _{10 of} from about 3 to about 20. In other preferred embodiments, the D ₁₀ may be outside this range. In some preferred embodiments, D ₁₀ is about 4.0, about 5.0, or about 6.0. In other preferred embodiments, D ₁₀ may be about 6.5, about 7.0, about 7.5, about 8.0, or about 8.5. In still some embodiments, the D ₁₀ value is about 9.0, about 10.0, about 11.0, about 12.0, or about 13. Other spray drying particles may have a D ₁₀ value of about 15.

Typically, spray dried particles have a D ₅₀ value of from about 10 to about 60, although in some preferred embodiments, the D ₅₀ value may be outside the specified range. In some preferred embodiments, the D ₅₀ is about 15.0, about 17.0, about 20.0, or about 22.0. In other preferred embodiments, the D ₅₀ value is about 23, about 24.0, about 25.0, or about 26.0. In still some preferred embodiments, the D ₅₀ value is about 28.0, about 30.0, about 40.0, or about 50.0.

The particles have a D ₉₀ value, which is usually from about 20 to about 70. In some preferred embodiments, D ₉₀ is about 35, about 40, or about 45. In other preferred embodiments, D ₉₀ is about 46.0, about 47.0, about 48.0, or about 49.0. In still some preferred embodiments, the filler has a D ₉₀ value of about 50, about 52, about 54, about 56, about 58, or about 60.

The width or narrowness of the particle size distribution can be described using the size of the distribution. The distribution span is defined as (D ₉₀ -D ₁₀ ) / (D ₅₀ ). Suitable spray drying particles typically also have a distribution span of about 1.0 to about 3.0. In some preferred embodiments, the distribution range is about 1.2, about 1.3, about 1.4, or about 1.5. In other preferred embodiments, the range of distribution of the filler particles is about 1.6, or about 1.8, about 2.0, about 2.2, or about 2.5. In some preferred embodiments, the spray dried catalyst particles have a distribution span of less than about 2.0, less than about 1.8, or less than about 1.6. In other preferred embodiments, the particles have a distribution span that is less than about 1.5, about 1.3, or about 1.1. The required range of distribution varies with the application.

In some preferred embodiments, the spray drying catalyst precursor composition is modified with a Lewis acid. The treatment can be carried out by dissolving the Lewis acid compound (s) in an inert liquid solvent, and treating the spray drying catalyst precursor composition with the resulting solution from any convenient processing method used, for example, by simply dipping the supported catalyst precursor composition in a Lewis acid solution. The solvent for the Lewis acid must be non-polar and capable of dissolving the compound (s) of the Lewis acid, but not the catalyst precursor composition. Among the solvents that can be used to dissolve the Lewis acid compound (s) are hydrocarbon solvents, including substituted hydrocarbon solvents, for example, isopentane, hexane, heptane, toluene, xylene, naphtha and aliphatic mineral oils, such as but not limited to Kaydol ™, Hydrobrite ™ 1000, Hydrobrite ™ 550, and the like. It is preferable to use such solvents together with the Lewis acid compound (s) in such quantities that the resulting solution contains from about 1 to about 25 percent by weight of the Lewis acid compound (s). If desired, the catalyst precursor composition may be added to an inert liquid solvent to form a suspension before the Lewis acid compound (s) are dissolved in the solvent. Alternatively, the Lewis acid compound (s) can be dissolved in an inert liquid solvent before being added to the suspension. This technique is particularly suitable when a gaseous compound, for example, BCl _{3, is used} . Alternatively, if desired, the Lewis acid can be directly added to the dry catalyst precursor composition.

Suitable Lewis acids are reagents that are capable of at least partially removing an electron donor without destroying the inorganic components of the catalyst precursor composition. In general, suitable Lewis acid compounds have the structures R _g AlX _3-g and R _g BX _3-g , where R is R 'or OR', or NR ' ₂ , where R' is a substituted or unsubstituted aliphatic hydrocarbyl group, containing from 1 to 14 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbyl radical containing from 6 to 14 carbon atoms; X is selected from the group consisting of Cl, Br, I and mixtures thereof; g in each case is 0-3.

Typical compounds of Lewis acids include tri-n-hexyl aluminum, triethyl aluminum, diethyl aluminum chloride, trimethylaluminum, dimethylaluminum chloride dichloride, methylaluminum, triisobutyl aluminum, tri-n-butylaluminum, diisobutylaluminum chloride, isobutylaluminium dichloride, (C ₂ H ₅₎ AlCl _2, (C ₂ H ₅ O) AlCl ₂ , (C ₆ H ₅ ) AlCl ₂ , (C ₆ H ₅ O) AlCl ₂ , (C ₆ H ₁₃ O) AlCl ₂ , and the corresponding bromine and iodine compounds.

Suitable boron halide compounds include BCl ₃ , BBr ₃ , B (C ₂ H ₅ ) Cl ₂ , B (OC ₂ H ₅ ) Cl ₂ , B (OS ₂ H ₅ ) ₂ Cl, B (C ₆ H ₅ ) Cl ₂ , B (OC ₆ H ₅ ) Cl ₂ , B (C ₆ H ₁₃ ) Cl ₂ , B (OC ₆ H ₁₃ ) Cl _2, and B (OC ₆ H ₅ ) ₂ Cl. You can also use containing bromine and iodine congeners of the above compounds. Lewis acids can be used individually or in combination.

Further details regarding Lewis acids that are suitable for this purpose can be found in US Pat. Nos. 4,354,009 and 4,379,758.

The catalyst precursor is treated with an activating co-catalyst. The catalyst precursor can be treated with a co-catalyst at any time after spray drying. In some preferred embodiments, the catalyst precursor is treated with a co-catalyst after optional treatment with a Lewis acid or alkylating agent. Typically, the co-catalyst corresponds to the formula AlX ’ _d (R ″) _c H _e , where X ″ is Cl or OR ″ ″; R ″ and R ″ ″ individually are C ₁ -C ₁₄ saturated hydrocarbon radicals; d is 0-1.5; e is 0 or 1; c + d + e = 3. Typical co-catalysts include Al (CH ₃ ) ₃ , Al (C ₂ H ₅ ) ₃ , Al (C ₂ H ₅ ) ₂ Cl, Al (i-C ₄ H ₉ ) ₃ , Al (C ₂ H ₅ ) _{1 , 5} Cl _1.5 , Al (iC ₄ H ₉ ) ₂ H, Al (C ₆ H ₁₃ ) ₃ , Al (C ₈ H ₁₇ ) ₃ , Al (C ₂ H ₅ ) ₂ N, Al (C ₂ H ₅ ) ₂ (OS ₂ H ₅ ), or mixtures thereof.

In some preferred embodiments, the catalyst precursor is partially activated outside the polymerization reactor, together with a co-catalyst in a hydrocarbon slurry. Such partial activation is optional. After contacting the catalyst precursor composition with the co-catalyst, the hydrocarbon solvent is removed by drying, and the catalyst composition can be fed to the polymerization reactor, where activation is completed using additional quantities of any suitable co-catalyst. In a first step, the supported catalyst precursor reacts with a co-catalyst to provide an Al: Ti molar ratio of about 0.1, 0.5, 1, 2, 5, or 6. In some preferred embodiments, the activation is carried out in a hydrocarbon solvent , it is followed by drying the resulting mixture, in order to remove the solvent, at a temperature of at least 20, 30, 40 or 50 ° C. In some preferred embodiments, the temperature is less than 50, 60, 70, or 80 ° C. Another alternative partial activation technique is described in US Pat. No. 6,187,866, in which the partial activation procedure proceeds continuously.

In some preferred embodiments, especially those in which the catalyst precursor is not fully activated, an additional co-catalyst may be added to the polymerization reactor to further activate the catalyst precursor. In some preferred embodiments, the partially activated catalyst or catalyst precursor composition, as well as additional co-catalyst, are fed to the reactor through separate feed lines. In other preferred embodiments, a suspension of the partially activated catalyst and co-catalyst in mineral oil is fed to the reactor through a single feed line. Alternatively, a suspension of the catalyst precursor composition in mineral oil may be treated with a co-catalyst, and the resulting suspension may be fed to the reactor. Additional co-catalyst can be sprayed into the reactor in the form of its solution in a hydrocarbon solvent, for example, isopentane, hexane or mineral oil. This solution usually contains about 2-30 wt.% The composition of the co-catalyst. The co-catalyst can also be added in solid form to the reactor when it is absorbed on a support. In some preferred embodiments, the carrier contains about 10-50 wt.% Activator for this purpose. Additional co-catalyst is added to the reactor in such quantities as to obtain in the reactor a total Al / Ti molar ratio of about 10, about 15, about 25, about 45, about 60, about 100, or about 200 to 1. In other preferred embodiments, the ratio may be about 250, or about 400 to 1. Additional amounts of activator compound added to the reactor further activate the supported catalyst. In other preferred embodiments, the catalyst can be activated as described in International Patent Application WO 01/05845, incorporated herein by reference in its entirety.

The preferred catalysts described above can be used in solution, suspension, or gas phase polymerizations. The catalysts described above can be prepared for use in suspension polymerization by any suitable technique. In some preferred embodiments, such catalysts are prepared in the same manner as catalysts used in gas phase polymerization. Suspension polymerization conditions include the polymerization of C ₂ -C ₂₀ olefins, diolefins, cycloolefins, or mixtures thereof in an aliphatic solvent at a temperature below that at which the polymer is readily soluble in the presence of a supported catalyst. Suspension phase processes suitable for homopolymerizing ethylene and copolymerizing ethylene with C ₃ -C ₈ alpha olefins, such as, for example, butene-1, hexene-1, 4-methylpentene-1 and octene-1, can also be carried out using preferred embodiments of the catalysts of the present invention. You can get in this way high density polyethylene (HDPE), medium density polyethylene (MESP) and linear low density polyethylene (LLDPE).

In a continuous gas phase process, partially or fully activated catalyst precursor compositions are continuously fed into the reactor, with separate portions of any additional activator compound necessary to complete the activation of the partially activated catalyst precursor composition in the continuous polymerization process, in order to replace the active catalytic centers that have been consumed in the process of the reaction.

Polymerization reactions are usually carried out by contacting an ethylene stream, in a gas phase process, for example, in a fluidized bed process described below, and in the absence of catalytic poisons such as moisture, oxygen, CO, CO ₂ and acetylene, using a catalytically effective amount of activated catalyst precursor composition (s) at a temperature and pressure sufficient to initiate a polymerization reaction. Preferred catalyst variants are suitable for the polymerization of C ₂ -C ₆ olefins, including homopolymers and copolymers of ethylene with alpha olefins, such as butene-1, hexene-1, 4-methylpentene-1. In general, the reaction can be carried out under any conditions suitable for Ziegler-Natta type polymerization carried out under suspension or gas phase polymerization. Such methods are used in industry to obtain high density polyethylene (HDPE) medium density polyethylene (MESP), and linear low density polyethylene (LLDPE).

In gas phase polymerization, a fluidized bed reaction system can be used. Fluidized bed reaction systems are discussed in detail in US Pat. Nos. 4,302,565 and 4,379,759, which are incorporated herein by reference in their entireties. However, for certainty, FIG. 3 shows a typical fluidized bed reactor system. The reactor 10 consists of a reaction zone 12 and a speed reduction zone 14. The reaction zone 12 includes a layer of growing polymer particles, the resulting polymer particles and a small amount of catalyst particles liquefied by blowing through the reaction zone a continuous stream of polymerizable and modifying gaseous components in the form of prepared in advance flow and recycle gas. The mass flow of gas through the catalyst bed is sufficient to fluidize the bed. To denote the minimum gas flow required to achieve liquefaction, it is acceptable to use the abbreviation G _mf , C. Y. Wen and YHYu, "Mechanics of Fluidization", Chemical Engineering Progress Symposium Series, Vol. 62, pp. 100-111 (1966). In some preferred embodiments, the gas mass flow rate is 1.5, 3, 5, 7, or ten times greater than G _mf . The catalyst layer is prepared so as to avoid the formation of localized "hot spots" and that individual particles of the catalyst were inside and were well distributed over the reaction zone. At the time of starting the reaction, the reaction zone usually contains a base in the form of loose polymer particles, before a gas stream is introduced. Such particles may be the same in nature with the polymer that will be formed, or differ from it. If the starting particles are different, they are removed together with the target formed polymer particles as the first product. Over time, the initial layer is replaced by a fluidized bed consisting of particles of the target polymer.

The partially or fully activated catalyst used in the fluidized bed is preferably stored until use in a container 32 under a layer of gas that is inert with respect to the stored material, for example, under nitrogen or argon.

Liquefaction is achieved by the high speed of the recycle gas in and through the bed, usually about 50 times the speed of the fresh gas stream. The fluidized bed usually looks like a dense mass of stable particles in an as-possible vortex-free flow that forms when gas leaks through the bed. The pressure drop in the layer is equal to or slightly higher than the mass of the layer divided by the cross-sectional area. Therefore, it depends on the geometry of the reactor.

Fresh gas is fed into the bed at a rate equal to that at which the bulk polymer product is removed. The composition of the fresh gas is determined by a gas analyzer 16 located above the layer. The gas analyzer determines the composition of the gas that is recirculated, and the composition of the fresh gas is regulated in accordance with these data, in order to maintain a practically stationary state in terms of the composition of the gas inside the reaction zone.

To ensure sufficient liquefaction, the recycle gas and, if desired, part of the fresh gas is returned to the reactor at a point 18 below the bed. There is a gas distribution plastic 20 above the return point, which helps in fluidizing the layer.

The portion of the gas stream that has not reacted in the bed is recycle gas, which is removed from the polymerization zone, preferably by passing into the zone of reduced flow rate 14 above the bed, where the particles entrained by the stream are allowed to return to the fluidized bed. Particle recovery is facilitated by the use of cyclone 22, which may be part of a recycling line. If desired, the recycle gas can then be passed through a pre-heat exchanger 24 installed to cool small entrained particles, to prevent sticking in the compressor, or through the downstream heat exchanger 26.

The recycle gas is compressed in a compressor 25 and then passed through a heat exchanger 26, where reaction heat is taken from it before it is returned to the bed. As a result of the constant heat removal of the reaction, apparently, there is no significant temperature gradient inside the upper part of the layer. A temperature gradient exists in the lower part of the layer, in a layer about 6-12 inches thick, a gradient arises between the temperature of the incoming gas and the temperature of the rest of the layer. Thus, it was noticed that the layer regulates the temperature of the recycle gas above the lower layer of the reaction zone, which makes it correspond to the temperature of the rest of the reaction layer, thus it is maintained at a practically constant temperature under stationary conditions. Then, the recycle gas is returned to the reactor at its base 18 and to the fluidized bed through the distribution plate 20. The compressor 25 can also be placed above the heat exchanger 26.

The fluidized bed contains growing and forming bulk polymer particles, as well as catalyst particles. Since the polymer particles are hot and active, they should be protected from precipitation to prevent the two particles from sticking together. Therefore, it is important that the recycle gas passes through the bed at a speed sufficient to maintain the bed in a fluidized state at the bottom of the bed. The distribution plate 20 serves this purpose and can be a screen, a plate with slots, a perforated plate, a bubble nozzle variant and the like. The elements of the plate may all be stationary, or the plate may be of the movable type described in US Pat. No. 2,298,792. No matter how it is arranged, it must pass recycle gas through the particles at the base of the fluidized bed to maintain these particles in a fluidized state, and also serve support for settled polymer particles when the reactor is down. The movable elements of the plate can be used to unload any polymer particles trapped inside or on the plate.

Hydrogen can be used as a chain transfer agent in the polymerization reaction. The hydrogen / ethylene ratio used can vary from about 0 to about 2.0 moles of hydrogen per mole of ethylene in the gas stream.

Compounds of the structure ZnR _a R _b , where R _a and R _b are the same or different C ₁ -C ₁₄ aliphatic or aromatic hydrocarbon radicals, can be used in combination with hydrogen, to control molecular weight, or as chain transfer agents, to increase the values of the melting index of the polymers that are produced in this process. You can use about 0-50, preferably about 20-30 moles of zinc compounds (calculated on zinc) in the gas stream in the reactor per mole of titanium compounds (calculated on titanium) in the reactor. The zinc compound can be introduced into the reactor, preferably in the form of a dilute solution (2-30 wt.%) In a hydrocarbon solvent, or absorbed on a solid diluent, for example, silicon dioxide, in the above forms, in amounts of about 10-50 wt.%. These compounds tend to be pyrophoric. Zinc compounds can be added separately or together with any additional portions of the activator compound, which are fed to the reactor from a feed device, which in FIG. not shown, which will supply the connection to the hottest part of the gas recycling system, for example, adjacent to the feed device 27 described in the present description.

Any gas inert to the catalyst and reactants may also be present in the gas stream. The activator compound is preferably added to the reaction system in the hottest part of the recycle gas stream. The addition to the recycling line downstream of the heat exchanger is therefore preferred, as, for example, from the distributor 27 via line 27A.

To ensure that particles do not stick together, it is advisable to use operating temperatures below the stick temperature. To obtain ethylene homopolymers, a working temperature of from 30 to 115 ° C is preferred, and a temperature of from about 80 to 105 ° C is preferably used to obtain products having a density of less than 0.94 g / cm ³ .

The fluidized bed reactor operates at pressures up to about 1000 psi. inch and preferably operates at a pressure of from about 150 to 350 psi. inch, and work at higher pressures in these ranges favors heat transfer, since increasing pressure increases the volumetric heat capacity of the gas.

A partially or completely catalytic composition is injected into the fluidized bed at a rate equal to its consumption, at point 30, which is located above the distribution plate 20. The injection can be continuous or intermittent. Preferably, the catalyst is injected at a point above the distribution plate. Since the described catalysts are highly active, the injection of a fully activated catalyst into the region below the distribution plate can cause polymerization to begin at this point, and ultimately lead to clogging of the distribution plate. The introduction of a fluidized bed, on the contrary, helps in the distribution of the catalyst in the layer and helps to prevent the formation of local spots with a high concentration of catalyst, which can lead to the formation of "hot spots".

A gas that is inert to the catalyst, such as nitrogen or argon, is used to feed a partially or fully reduced catalyst precursor composition, and any necessary additional activator compound, to the reaction layer. Alternatively, a mixture of solvents, for example, isopentane, pentane, hexane, or the like, can be used as a carrier for catalysts in suspension. Nitrogen may be used in combination with a carrier.

The rate of polymer formation in the reaction layer is controlled by the feed rate of the catalyst. The polymer formation rate can be increased by simply increasing the catalyst feed rate and reduce by reducing the catalyst feed rate.

Since changes in the catalyst feed rate change the rate of heat generation of the reaction, the temperature of the recycle gas is adjusted to decrease or increase in order to adapt to the changes in the rate of heat generation. This makes it possible to confidently maintain a practically constant temperature in the reaction layer. Naturally, it is necessary to fully equip both the fluidized bed and the recycle gas cooling system with the necessary equipment to determine any temperature changes in the reaction layer in order to enable the operator to appropriately control the temperature of the recycle gas.

Under this set of operating conditions, the fluidized bed is maintained at an almost constant height by removing part of the layer as a product at a rate equal to the rate of formation of the bulk polymer product. Since the rate of heat generation is directly related to the formation of the product, measuring the increase in gas temperature over the height of the reactor (the difference between the temperature of the gas at the inlet and the temperature of the gas at the outlet) is decisive for the rate of formation of bulk polymer at a constant gas velocity.

The bulk polymer product is preferably continuously removed at a point 34 located on or close to the distribution plate 20, and in suspension with a portion of the gas stream that is purged before the particles settle, in order to prevent further polymerization and adhesion when the particles reach their final zone collection. Suspending gas can also be used, as mentioned above, to transfer the product from one reactor to another reactor.

The free flowing polymer product is preferably, although not necessarily, removed by sequential operation of a pair of batch valves 36 and 38 separating the separation zone 40. If the valve 38 is closed, the valve 36 is open to release a locked portion of the gas and the product into the zone 40 located between it and a valve 36, which is then closed. Valve 38 is then opened to transfer the product to the external separation zone. Valve 38 is then closed, awaiting the next product isolation step. You can also use the method of unloading the fluidized bed in accordance with patent US 4621952, in its entirety is incorporated into this description by reference.

Finally, the fluidized bed reactor is equipped with an appropriate purge system that allows the reaction bed to be purged during start-up and shutdown. The reactor does not require the use of mixing means and / or means for cleaning the walls.

The catalyst system described herein appears to produce a fluidized bed product having an average particle size of from about 0.005 to about 0.06 inches, sometimes from about 0.02 to about 0.04 inches, and having a residual catalyst content which is unusually small.

A feed stream of gaseous monomer, with or without inert gaseous diluents, is fed to the reactor at a feed rate of about 2-10 pounds / hour / cubic foot of reaction volume.

In some preferred embodiments, the catalysts obtained in accordance with the present description, have improved performance. Productivity is measured by ashing the sample of the obtained resin and determining the mass percentage of ash. Ash essentially consists of a catalyst. Productivity is calculated as pounds of polymer obtained per pound of total catalyst used. The amount of Ti, Mg and Cl in the ash is determined by elemental analysis. In some preferred embodiments, the productivity of the catalyst is from about 6,000 to about 15,000 for suspension polymerization. In other preferred embodiments, the catalysts have performance values above or below this range. For gas phase polymerization reactions, some of the catalysts of this invention have a productivity of from about 2 to about 5 ppm. Ti. Here again, other catalysts may have a performance outside the specified range.

The molecular weight of the polymer is conveniently measured using melt flow measurements. One of these indicators is the melting index (PI), which is determined in accordance with ASTM D-1238, condition E, measured at 190 ° C and a load of 2.16 kg is applied, and is given as grams in 10 minutes. The polymers obtained using some of the catalysts described herein have IP values that are from about 0.01 to about 10,000. Other polymers can have IP values that go beyond these limits. Another way to characterize polymers is to measure the melt flow rate, it is measured in accordance with ASTM D-1238, condition F, using ten times more polymer by weight, compared to the determination of the melting index described above. The melt flow rate is inversely proportional to the molecular weight of the polymer. Thus, the higher the molecular weight, the lower the melt flow rate, although the ratio is not linear. The melt flow ratio (OPR) is the ratio of the melt flow rate to the melting index. It correlates with the distribution of the obtained polymer by molecular weight. Lower ODPs mean narrower molecular weight distributions. Polymers prepared using some of the catalysts described herein have ODA values of from about 20 to about 40.

The average particle sizes of the polymers are calculated based on sieve analysis in accordance with ASTM D-1921 Method A using 500 g of sample. The calculations are based on the mass fractions of the polymer remaining on each sieve. Bulk density is determined in accordance with ASTM D-1895, Method B, by pouring the resin into a graduated cylinder of 100 ml to 100 ml without shaking the cylinder, and determining the mass of the difference.

Polymers can also be characterized by their density. The polymers in the present description can have a density of from about 0.85 to about 0.98 g / cm ³ if it is measured in accordance with ASTM D-792, in which a disk is made and conditioned for one hour at 100 ° C, for achieving equilibrium crystallinity. The density measurement is then carried out in a density gradient column. Others may have a bulk density determined in accordance with ASTM D-1895, Method B, which is from about 0.2 to about 0.4 g / cm ³ .

Examples

The following examples are provided to illustrate various preferred embodiments of the invention described herein. They should not be construed as intended to limit the scope of the invention in a manner other than that described in the description and claims. All figures are approximate.

Spray drying device

Typical catalysts were prepared using a Niro ^® spray dryer. The spray chamber was 4 feet in diameter, the length to diameter ratio was approximately 1.2, and the angle at the base of the cone was approximately 45 °. Spraying was carried out using a Niro FU-11 rotary grinder equipped with a bezelless wheel 120 mm in diameter. The spray drying device worked in a direct-flow closed-cycle mode. Although any gas inert to the constituent components of the catalyst can be used in the spray drying apparatus, nitrogen is usually used because of its low cost and the easy availability of high purity nitrogen. The evaporated solvent is removed from the recycle return gas and cooled by passing through a packed column in which a cold solvent is circulated in countercurrent. The waste return gas is then saturated with solvent at the outlet temperature. The return gas is then heated in a heat exchanger and returned to the system. Dry solids are isolated using a cyclone and stored under an inert gas.

Raw material preparation

Typical catalysts were prepared in a 40 liter stainless steel mixing vessel equipped with suitable feed openings, a turbine mixer with flat blades, and a gas purge device. The components of the catalyst can be loaded into the mixer, without observing a specific loading order. Typically, however, at least a portion of the solvent is first loaded into the mixer. In one example, tetrahydrofuran was loaded into the mixer, and then optionally the filler was loaded if used. The temperature of the contents of the mixer was brought to the desired value, usually about 35-50 ° C. Then, while maintaining the contents of the vessel under a layer of inert gas, without observing a certain order of addition, the required amounts of magnesium chloride and reduced aluminum titanium chloride (TiCl ₃ AA) were loaded into the mixer. Then alcohol was added. The contents of the vessel were constantly mixed. The internal temperature was adjusted to the desired value, and the contents were stirred for 2-4 hours. However, mixing times of up to 48 hours are not harmful to the product. There is no defined minimum mixing time; the time should simply be sufficient to achieve dissolution.

In another example, the feed was prepared by adding solvent to the mixer, then filler was added thereto. A small amount of alkylaluminum, for example, triethylaluminum, was added as a solution in an electron-donor solvent so that it reacts with moisture, which is inevitably present in the filler compound. Then, while maintaining the contents of the vessel under an inert gas, without adhering to a specific order of addition, magnesium chloride and aluminum-reduced titanium chloride (TiCl ₃ AA) were charged into the mixer in the required quantities. A small additional amount of a solution of alkylaluminum can be added so that it reacts with the moisture present in MgCl ₂ . The reaction was maintained under these conditions for about 30 minutes to 1 hour. After this period, alcohol was added. The resulting mixture was constantly stirred, the internal temperature was brought to the desired level, and the contents were stirred for 2-4 hours.

In a third example, the feed was prepared by first loading the solvent into the reaction vessel, then filler was added. A small amount of alkylaluminum, for example triethylaluminum, was added as a solution in an electron-donor solvent. Then, maintaining the contents of the vessel under an inert gas, without adhering to a specific order of addition, metallic Mg and TiCl _{4 were} charged as described in US Pat. No. 5,290,745, incorporated herein by reference. After a mixing period of 1-4 hours, additional MgCl ₂ was charged to increase the total Mg / Ti molar ratio to the desired value. Although not required, at this point a small amount of an aluminum alkyl solution was charged into the reactor. The reaction was continued as described above.

Spray drying

After preparing the spray drying raw materials, the suspension was filtered through a 20 mesh (US) sieve to homogenize the suspension, and then pumped into a rotary grinder. The inlet temperature was adjusted to control the temperature at the outlet of the drying device, which, in turn, controls the amount of residual solvent remaining in the dried solids. The feed rate was adjusted so as to achieve the desired rate of solid formation. The cyclic gas flow rate was set to ensure that solids that form in the drying chamber are transferred to the cyclone to collect the solid product. The grinder speed (rpm) was chosen so as to control the particle size of the solid products. The temperature at the outlet of the condenser used to remove the solvent from the drying gas was maintained at a level of from about −20 ° C. to about + 20 ° C. to control the amount of residual solvent remaining in the drying gas.

The use of precursors of spray drying catalysts

Precursor suspension / solution

The amounts used for preparation are listed in table 1. All operations were performed under nitrogen using anhydrous reagents. The required loading of tetrahydrofuran (THF) was added to a 40 L stainless steel mixing vessel, followed by the indicated loading of filler (Cabosil TS-610, manufactured by Cabot Corporation). The suspension was stirred at room temperature for 30 minutes. A small amount of triethyl aluminum (10% solution in THF) was then added to remove residual moisture from the filler and solvent. The suspension was stirred for 15 minutes, the required amounts of solid MgCl ₂ and TiCl ₃ -AA were added. Then, the required amount of absolute ethanol was added, either before or after the addition of metal salts. The internal temperature was raised to 60 ° C, and the suspension was stirred for 5 hours at an internal temperature of 60-70 ° C.

Table 1 Obtaining suspensions of spray drying Solution preparation Example THF kg Cabosil, kg 10% Et ₃ Al, g Et ₃ Al, mol MgCl ₂ , g MgCl ₂ , mol TiCl ₃ -AA, g TiCl ₃ -AA, mol EtOH, g EtOH, mol Nominal EtOH / Mg Nominal [MgCl ₂ ], molar. BUT* eighteen 1.14 363 0.3 918 9.63 327 1,64 0 0 0 0.5 AT 36,2 2,51 450 0.39 1805 18.9 667 3.36 750 16.3 one 0.5 FROM 27.1 2,51 450 0.39 2776 29.1 667 3.36 1201 26.1 one one D 28 1.7 770 0.67 3124 32.8 1053 5.30 1542 33.5 one one * comparative example

The data in table 1 show that solutions with high concentrations of MgCl ₂ can be easily prepared and dried by spray drying at a relatively higher content of active components than was previously possible. On the contrary, attempts were made to spray drying 1 molar suspension of MgCl ₂ with a MgCl ₂ / TiCl ₃ ratio of 6: 1 in the absence of an alcohol modifier. Not all MgCl ₂ was in solution at room temperature, and heating the suspension to 65 ° C and attempted spray drying caused the pipe system to become clogged with undissolved and solid precipitated during the drying process.

Spray Drying

The resulting AD suspensions containing dissolved MgCl ₂ and TiCl ₃ were then dried using spray drying, the drying conditions were changed using an 8-foot diameter closed-cycle spray dryer equipped with a rotary grinder. The speed of the rotary grinder was regulated in the range of 50-95% of the installation speed to obtain particles in a wide range of particle sizes. 100% chopper speed corresponds to 24,000 rpm. The scrubbing section of the spray drying apparatus was maintained at a temperature of about −4 ° C.

Nitrogen gas was introduced into the spray drying apparatus at an inlet temperature in the range of 130-160 ° C, and it circulated at a rate of about 200-300 kg / h. A Cabosil / THF slurry containing dissolved MgCl ₂ and TiCl ₃ was fed to a spray dryer at a temperature of about 65 ° C. at a rate sufficient to reach a gas outlet temperature of about 90-115 ° C. The pressure in the chamber of the spray drying device was slightly higher than atmospheric.

Particles obtained by spray drying had D ₁₀ , D ₅₀ and D ₉₀ determined on a Malvern 2600 particle size analyzer. The analytical and morphological results are shown in Table 2.

table 2 Determination of the parameters of the precursors of spray drying catalysts. Example Grinder installations,% Ti, mmol / g Mg, mmol / g Mg / Ti % THF % EtOH D ₉₀ D ₅₀ D ₁₀ Distribution range BUT* 80 0.44 2.74 6.25 26.6 49.34 26.52 10.56 1,5 AT 80 0.56 2.66 4.75 19.3 four 46.58 22.16 6.96 1.8 FROM 85 0.41 3.63 9 32 5.1 58.70 29.98 12.82 1,5 D 95 0.6 3.62 6 36 6.2 47.65 23.83 8.28 1.7 D ' 95 0.6 3.62 6 36 6.2 48.59 23.06 8.24 1.7 * comparative; the inlet temperature was 150 ° C, except for D ', where the inlet temperature was 160 ° C.

The data in table 2 show that the dried particles with good morphological properties at increased concentrations can be obtained under normal conditions of spray drying. If the concentration of MgCl ₂ in the feed solution is increased, it is possible to obtain particles with significantly higher Mg / Ti ratios when loaded with 0.4-0.5 mmol Ti / g of precursor. Such catalysts can be used where a high degree of modification of MgCl ₂ and a uniform Ti environment are required. If the concentration of both MgCl ₂ and TiCl ₃ in the feed solution is increased, it is possible to obtain particles with a constant Mg / Ti ratio, but a significantly higher Ti content than in the control catalyst. Such catalysts can be used in cases where it is necessary to carry out the polymerization under conditions of low partial pressure of ethylene, when a low activity based on titanium will otherwise lead to an unexpectedly low particle size of the resin.

Table 2 also shows that particle morphology, particle size, and particle size distribution of certain catalyst precursors can be achieved, approximately equivalent to the same characteristics of traditional precursors, except that the control sample may contain a slightly lower amount of fines. However, from FIG. 4, which shows scanning electron microscopy (SEM) photographs of particles, it can be seen that the fine particles in the comparative traditional precursor of FIG. 4A are present in a much more agglomerated form than the particles of a typical catalyst of this invention shown in figv. So, figa shows that the lower fines in the comparative catalyst precursors obtained due to the undesirable formation of agglomerated particles. Conversely, the catalyst precursors of this invention exhibit less agglomeration and greater adhesion, as can be seen from the presence of predominantly uniformly spherical particles in FIG. 4 B. Typically, at least most particles are not agglomerated.

Polymerization of ethylene in a slurry reactor

The catalyst precursors from Table 2 were used in ethylene polymerization tests, the results of which are shown in Table 3. Each laboratory scale polymerization test was carried out as described below, except as otherwise specified. 40-60 micromoles of triethylaluminium (C ₂ H ₅ ) ₃ Al per micromole of titanium in the catalyst were added to 500 ml of hexane, then 5-7 micromoles of titanium were added to the reactor as a suspension of the catalyst precursor in mineral oil. A 1 L suspension polymerization reactor was pressurized to fifty (40) psi. inch (rel.) with hydrogen, then brought to a total pressure of two hundred (200) psi. inch (rel.) using ethylene. The polymerization was carried out at a temperature of 85 ° C for thirty minutes.

Table 3 Suspension polymerization experiments. Example Mg / Ti ROH / Mg Ti loading, mmol / g Activity ^a Performance ^b IP, dg / min SPR Bulk density, g / cm ³ BUT* 6 0 0.44 14,400 5,800 1,6 32 0.38 AT 5 one 0.56 14,400 7,000 1.7 32 0.37 FROM 9 one 0.41 23,000 9,500 0.9 35 0.33 D 6 one 0.6 11,800 7,200 0.9 42 0.29 D ' 6 one 0.6 19,200 11,600 1.4 thirty 0.26 *: comparative example; a: in g PE / (mol of titanium-h-100 psi C ₂ ); b: in g PE / (g catalyst-h-100 psi C ₂ )

From table 3 it is seen that the performance of the catalyst based on activated precursors in suspension polymerization, calculated in g PE / g of catalyst, is higher than the performance of the control precursor (A). An increase in the Mg / Ti ratio leads to an increase in titanium productivity. With an equal Mg / Ti ratio and a higher content of both MgCl ₂ and TiCl ₃ , higher particle productivity for the catalysts in Examples BD 'in Table ₃ is achieved than in the presence of the control catalyst from Experiment 1.

The method of polymerization of ethylene in a fluidized bed reactor

The catalyst precursors from Table 2 were used in ethylene polymerization tests, the results of which are shown in Table 4.

As can be seen from table 4, the properties of the resin, such as the melting index, density, molecular weight distribution of the resin and the bulk density of the resin obtained using the catalyst In the present invention, are similar to the polymerization properties of the control catalyst obtained on an industrial scale on a commercial spray drying device . Although the catalyst of the present invention is slightly less productive than the control, so that a smaller particle size and an increased fines content would be expected, they instead exhibit a slightly increased particle size and a half reduced fines content compared to those obtained using the control catalyst. SEM analysis of the resin shows that the resins of the present invention consist of sticky spheres, while the resin obtained using a catalyst previously known in the art contains individual particles and significant amounts of de-agglomerated fines.

Table 4 Fluidized HDPE polymerization Example Mg / Ti ROH / Mg Ti content, mmol / g Productivity, ppm Ti The density of the resin, g / cm ³ IP, dg / min SPR Bulk Density Pound / ft ³ The average particle size, inches Fines,% BUT* 6 0 0.47 2 0.9645 8.6 26.7 27.1 0,027 2.28 FROM 9 one 0.41 2,4 0.9646 8.1 25,4 27.1 0,037 1,1 D ' 6 one 0.6 3,7 0.9640 7.8 26 27,2 0.34 1.33

Polymerization conditions: polymerization temperature of 102 ° C, ethylene pressure of 170 psi. inch, 0.4 N ₂ / C ₂ . Co-catalyst triethylaluminium to an Al / Ti ratio of about 50-60.

As shown above, preferred embodiments of the invention provide a catalyst, a method for producing a catalyst, and a method for producing a polymer. A catalyst prepared in accordance with preferred embodiments of the invention may have one or more of the following advantages. Some of the catalysts described in the present description do not decompose during the polymerization process, which makes it possible to obtain a more complete polymer particle. Thus, the catalysts provide polymers that have a lower content of undesirable small particles. The catalyst also has improved particle performance compared to catalysts that use conventional spray drying particles. Improved performance means that the catalysts provide a more cost-effective alternative to existing magnesium-titanium spray drying catalysts. These advantages are provided by a partially wider range of attainable compositions and a more uniform distribution of magnesium in the particle. Other advantages and features are apparent to those skilled in the art.

Although the invention is described using a limited number of preferred options, these specific preferred options are not intended to limit the scope of the invention in a different way than described and formulated in the present description. There are modifications and variations of the described preferred options. It is clear that the parameters of the polymerization methods can vary, for example, in temperature, pressure, monomer concentration, polymer concentration, partial pressure of hydrogen, and so on. Therefore, catalysts that do not meet the selection criteria for one set of reaction conditions can, however, be used in preferred embodiments of the invention with a different set of reaction conditions. Although some preferred embodiments are described with reference to a separate catalyst, this does not in any way preclude the use of two, three, four, five or more catalysts simultaneously in a single reactor, with a similar or different ability for molecular weight and / or introduction of a co-monomer. In some preferred embodiments, the catalyst may also include additives or other modifiers. In other preferred embodiments, the catalyst does not include, or substantially does not contain, any compounds not listed in the present description. Moreover, there are derivative variations and modifications. It should be recognized that the method described in the present description, can be used to obtain polymers, which also include one or more additional co-monomers. The introduction of additional co-monomers can lead to improved properties that are not achievable for homopolymers or copolymers. If the method is described as including one or more stages, it should be understood that these stages can be used in any order or sequence, unless otherwise indicated. These stages can be combined or separated. Finally, any number included in the present description should be taken as meaning an approximate value, regardless of whether or not the words “approximately” and “approximately” were used in the description of this number. Last but not least, the stated catalysts are not limited to the methods described herein. They can be prepared in any suitable way. The appended claims are intended to describe all such variations and modifications as fall within the scope of the present invention.

Claims (29)

1. The composition of the catalyst precursor, including a) a mixture of the reaction product of the following substances: 1) magnesium halide; 2) a solvent; 3) an electron-donor compound, wherein the electron-donor compound is alcohol; and 4) transition metal compounds, wherein the transition metal is selected from groups 3-10 and lanthanides; and b) inert filler; where a) and b) form a catalyst precursor, and where the specified catalyst precursor is obtained by spray drying, where the catalytic composition contains practically no other electron-donor compounds, the molar ratio of the electron-donor compound to magnesium is less than or equal to 1.9, and the catalyst precursor composition includes particles having an average particle size greater than about 10 microns, and where the specified magnesium halide has a solubility in the specified solvent in the range from 0.75 to 2.0 mol / L. 2. A method of obtaining a catalyst precursor composition, comprising a) obtaining a mixture or reaction product from: 1) magnesium halide; 2) a solvent; 3) an electron-donor compound, wherein the electron-donor compound is alcohol; 4) transition metal compounds, wherein the transition metal is selected from groups 3-10 and lanthanides; b) contacting the mixture or reaction product with an inert filler to obtain a suspension; and c) spray drying the suspension; where the catalyst precursor composition is substantially free of other electron-donor compounds, the molar ratio of the electron-donor compound to magnesium is less than or equal to 1.9, and the catalyst precursor composition includes particles having an average particle size of greater than about 10 μm, and where said halide magnesium has a solubility in the specified solvent in the range from 0.75 to 2.0 mol / L. 3. Catalytic composition comprising a reaction product from a) a mixture or reaction product from: 1) magnesium halide; 2) a solvent; 3) an electron-donor compound, wherein the electron-donor compound is alcohol; 4) transition metal compounds, wherein the transition metal is selected from groups 3-10 and lanthanides; and 5) an inert filler, and 6) composition of socialization, where the catalytic composition contains virtually no other electron-donor compounds, the molar ratio of the electron-donor compound to magnesium is less than or equal to 1.9, and the catalyst precursor composition includes particles having an average particle size of greater than about 10 μm, and where said magnesium halide has a solubility in the specified solvent in the range from 0.75 to 2.0 mol / L. 4. A method of producing a polymer, comprising the reaction of at least one polyolefin monomer in the presence of a catalyst composition comprising a mixture or reaction product a) magnesium halide; b) a solvent; c) electron-donor compound; d) transition metal compounds, wherein the transition metal is selected from groups 3-10 and lanthanides; e) an inert filler, and e) the composition of the cocatalyst, where the catalyst composition contains virtually no other electron-donor compounds, the molar ratio of the electron-donor compound to magnesium is less than or equal to 1.9, and the catalyst precursor composition includes spherical or substantially spherical particles having a particle size of from about 10 to about 200 microns and where the specified magnesium halide has a solubility in the specified solvent in the range from 0.75 to 2.0 mol / L. 5. The catalyst precursor composition according to claim 1, where the transition metal is titanium, where the catalyst precursor composition comprises particles having a molar ratio of magnesium to titanium of from about 1.0 to about 5.0. 6. The catalyst precursor composition according to claim 1, where the transition metal is titanium, where the catalyst precursor composition comprises particles having a molar ratio of magnesium to titanium of from about 5.0 to about 10. 7. The catalyst precursor composition according to claim 1, where the catalyst precursor composition includes particles having a distribution range from about 1 to about 2.5. 8. The catalyst precursor composition according to claim 1, where the inert filler comprises from about 10 to about 95 wt.% The composition of the catalyst precursor. 9. The catalyst precursor composition according to claim 1, where the molar ratio of alcohol to magnesium is less than about 1.75. 10. The catalyst precursor composition according to claim 1, where the molar ratio of alcohol to magnesium is from about 0.1 to about 1.1. 11. The catalyst precursor composition according to claim 1, where the molar ratio of alcohol to magnesium is from about 0.1 to about 0.5. 12. The catalyst precursor composition according to claim 1, where the transition metal compound includes titanium, zirconium, hafnium, vanadium, niobium, tantalum, or combinations thereof. 13. The catalyst precursor composition according to claim 1, where the transition metal compound corresponds to the formula Ti (R) _a X _b , where R is R 'or COR', where R 'is a C ₁ -C ₁₄ aliphatic or aromatic hydrocarbon radical, X is selected from Cl, Br, I, or mixtures thereof, and 0 or 1, b is from 2 to 4 inclusive, a + b = 3 or 4. 14. The catalyst precursor composition of claim 1, wherein the transition metal compound is TiCl ₃ , TiCl ₄ , Ti (OC ₆ H ₅ ) Cl ₃ , Ti (OCOCH ₃ ) Cl ₃ , Ti (OCOC ₆ H ₅ ) Cl ₃ or mixtures thereof. 15. The catalyst precursor composition according to claim 1, where the electron donor comprises a linear or branched aliphatic or aromatic alcohol containing from one to about 25 carbon atoms. 16. The catalyst precursor composition of claim 15, wherein the alcohol is selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, 2-ethylhexanol, 1-dodecanol, cyclohexanol and tert-butylphenol. 17. The catalyst precursor composition of claim 1, wherein the solvent is selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids, ethers and aliphatic ketones. 18. The catalyst precursor composition of claim 1, wherein the magnesium halide comprises MgCl ₂ , MgBr ₂ , MgI ₂ , MgClBr, MgBrI, or a mixture thereof. 19. The catalyst precursor composition according to claim 1, where the catalytic composition comprises a composition of the formula [Mg (ROH) _r ] _m Ti (OR) _n X _p [S] _q , where ROH includes a linear or branched alcohol containing from one to about 25 carbon atoms, R represents R 'or COR', where each R 'individually represents an aliphatic hydrocarbon radical containing from one to about 14 carbon atoms, or an aromatic hydrocarbon radical containing from one to about 14 carbon atoms; X is individually Cl, Br, or I; S is selected from the group consisting of alkyl esters, aliphatic ethers, cyclic ethers, and aliphatic ketones; the range of m is from 0.5 to 56; n is 0, 1 or 2; p is from 4 to 116; q is from 2 to 85; r is from 0.1 to 1.9. 20. The catalyst precursor composition according to claim 19, where r is from 0.1 to less than about 0.5. 21. The catalyst precursor composition according to claim 1, further comprising a mixture or reaction product of a Lewis acid with a catalyst precursor composition. 22. The catalyst precursor composition according to item 21, where the Lewis acid has the formula R _g MX _3-g , where R represents R ', or OR', or NR ' ₂ , where R' is a substituted or unsubstituted aliphatic or aromatic hydrocarbyl a group containing 1-14 carbon atoms, X is selected from the group consisting of Cl, Br, I, and mixtures thereof; g is 0-3, M is aluminum or boron. 23. The catalyst precursor composition of claim 21, wherein the Lewis acid is selected from the group consisting of tri-n-hexylaluminium, triethylaluminum, diethylaluminium chloride, trimethylaluminum, dimethylaluminum chloride, methylaluminum dichloride, triisobutylaluminum aluminum, tri-n-butylaluminyl aluminum, aluminum, aluminum , (C ₂ H ₅ ) AlCl ₂ , (C ₂ H ₅ ) AlCl ₂ , (C ₆ H ₅ ) AlCl ₂ , (C ₆ H ₅ O) AlCl ₂ , (C ₆ H ₁₃ O) AlCl _2, and combinations thereof . 24. The catalyst precursor composition of claim 21, wherein the Lewis acid is selected from the group consisting of BCl ₃ , BBr ₃ , B (C ₂ H ₅ ) Cl ₂ , B (OC ₂ H ₅ ) ₂ Cl ₂ , B (OC ₂ H ₅ ) ₂ Cl ₂ , B (C ₆ H ₅ ) Cl ₂ , B (OS ₆ H ₅ ) Cl ₂ , B (OS ₆ H ₁₃ ) Cl ₂ , B (OS ₆ H ₁₃ ) Cl ₂ and B (OS ₆ H ₅ ) ₂ Cl and combinations thereof. 25. The catalyst precursor composition according to claim 1, wherein the inert filler is selected from the group consisting of silicon dioxide, titanium dioxide, zinc oxide, magnesium carbonate, magnesium oxide, carbon and calcium carbonate. 26. The catalyst precursor composition of claim 25, wherein the composition has an average particle size of from about 10 to about 60 microns and a distribution range from about 1.5 to about 2.0. 27. The catalyst precursor composition according to claim 1, further comprising a second inert filler selected from the group consisting of silicon dioxide, titanium dioxide, zinc oxide, magnesium carbonate, magnesium oxide, carbon, and calcium carbonate. 28. Catalytic composition comprising a reaction product from a) magnesium halide; b) a solvent including tetrahydrofuran (THF); c) an electron-donor compound, wherein the electron-donor compound includes alcohol; d) transition metal compounds, wherein the transition metal is selected from groups 3-10 and lanthanides; and d) inert filler, where the concentration of said magnesium halide in the obtained solution of said magnesium halide, said alcohol, said THF, and said transition metal is 5 times higher compared to a solution not containing alcohol. 29. A method of producing a polymer comprising homopolymerization or copolymerization of ethylene with C ₃ -C ₈ α-olefins, wherein said homopolymerization or copolymerization is carried out in the presence of one of the catalyst precursors according to claim 2, or the catalytic composition according to claim 3, where said catalyst precursor optionally includes cocatalyst.

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