CS209829B2 - Catalytic method of making the ethylene copolymeres - Google Patents

Description

The invention relates to catalytic copolymerization of ethylene using highly active complex catalysts containing magnesium and titanium in a gas phase process to produce ethylene copolymers having a density of from 910 kg / m ³ inclusive to 940 kg / m ³ inclusive and a melt flow rate ratio (defined below). ranging from 26 inclusive to 40 inclusive.

In order to be useful in an industrial gas phase process, such as in the fluidized bed process of U.S. Patent Nos. 3,709,853, 4,003,712 and 4,011,382, Canadian Patent 991,798 and Belgian Patent 839,380, catalysts must have a high activity, i.e. It must have a productivity of at least 50,000 and preferably at least 100,000 kg of polymer per kg of catalyst metal or greater. This is because, in such gas-phase processes, no processes are generally used to remove catalyst residues. The catalyst residues in the polymer must therefore be so small that they can be left in the polymer without causing undesirable difficulties in the production of resins, resin processing and / or in the application of finished products to the end customer. Where highly active catalysts are successfully used in such fluidized bed processes, the heavy metal content of the resin is of the order of 20 ppm or less at a productivity of at least 50,000 or greater. The low content of catalyst residues is also important when the catalyst contains chlorine-containing substances, such as titanium, magnesium and / or aluminum chlorides, used in so-called Ziegler or Ziegler-Natta catalysts. The high chlorine content of the forming resin can cause pitting and other corrosion of the metal surfaces of the forming apparatus. A chlorine content of 200 ppm or higher is unacceptable for industrial production.

British Patent No. 1 310 547, published in March 1973, describes the preparation of high density (> 960 kg / m ³ ) ethylene homopolymers or copolymers using a supported catalyst, which is the reaction product of a co-milling product (preferably ball mill) either 1. a magnesium halide and addition of a titanium compound, or 2. a polyvalent titanium compound, an electron donor compound and an organometallic compound, or a metal hydride of Group I to III, such as aluminum, Examples of this patent describe the preparation of homopolymers and copolymers by slurrying.

U.S. Patent No. 3,888,835 issued June

1975, describes the homopolymerization or copolymerization of ethylene in suspension at high temperature in the presence of a catalyst consisting of A, a co-ground (milled ball mill) mixture of titanium halide, aluminum halide-ether-magnesium halide complex and B. of an organoaluminum compound. Another advantage of using the catalyst disclosed in the cited patent is that the aluminum halide / ether complex used is soluble in the hydrocarbon solvent and is removed from the polymer product by filtration.

U.S. Patent No. 3,991,260, issued November 1976, discloses the homopolymerization or copolymerization of ethylene in the presence of a catalyst prepared by co-milling (ball mill milling) magnesium halide, certain aluminum compounds, and vanadium or titanium compounds such as titanium tetrachloride or titanium tetrachloride, wherein the molar Mg / Al ratio in the catalyst is from 1: 0.01 to 1: 1. The polymerization reaction is carried out in suspension at high temperature. The catalyst is said to have high activity.

Thus, these patents, describing the use of certain magnesium and titanium containing catalysts milled in a ball mill, disclose their use mainly in slurry processes and not in the gas phase process at pressures below 6.87 MPa.

It is also known from the patents of Union Carbide Corporation that ethylene copolymers having a density of 910-960 kg / m ³ , a melt flow rate ratio (defined below) of from 22 to 32, including limit values, and a relatively low content of catalyst residues can be produced in granulated to a relatively high productivity such that the ethylene is copolymerized with one or more C3 to Ca aolefins by a gas phase process using a specific highly active complex catalyst comprising magnesium and titanium, which is mixed with an inert carrier.

Furthermore, it is known from the patents of Union Carbide Corporation that ethylene copolymers having a density of 910 to 940 kg / m ³ , a relatively low catalyst residue content and a relatively high bulk density can be produced at relatively high productivity by ethylene capolymerizing with one of which is a plurality of C3 to Cs α-olefins in the gas phase in the presence of a highly active complex catalyst comprising magnesium and titanium, which is impregnated in a porous inert carrier.

However, the processes for the preparation of the catalysts mentioned in the earlier patents are relatively complex, and precursors containing magnesium, titanium and an electron donor compound are prepared by crystallization or precipitation in these processes. In addition, the activation method is of decisive importance for obtaining effective catalysts according to these patents. Activation is performed in one of two ways. According to the first method, the precursor is completely activated outside the reactor. According to a second method, the precursor is only partially activated outside the reactor and the resulting partially activated precursor is fed to the polymerization reactor, where activation is completed with an additional amount of activating compound. Furthermore, the polymers produced using the catalysts of the earlier patents have a relatively narrow molecular weight distribution, corresponding to an Mw / Mn value of about 2.7 to 3.8.

In addition, the catalysts of the earlier US patents require the use of relatively high comonomer concentrations in the reactor to produce the copolymers described in these applications. This results in higher production costs of these ethylene copolymers.

It has now unexpectedly been found that ethylene copolymers having a density of from about 910 to about 940 kg / m ³ melt flow rate ratios of from about 26 to 40, including limit values, and which contain relatively mint catalyst residues, can be produced at relatively high productivity. suitable for industrial purposes by a gas-phase process which is not burdened with some of the disadvantages of the earlier US patents. The essence of the process of the invention is that ethylene is copolymerized with one or more C 3 -C 8 α-olefins in the presence of a highly active complex catalyst comprising magnesium and titanium, which is prepared as described below.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a process for producing ethylene copolymers having a density of from about 910 to about 940 kg / m ³ , a melt flow rate ratio of about 26 to 40 including limit values with relatively low catalyst residue. with relatively high productivity.

Giant. II graphically illustrates the effect of π ποοomeromeric ratio of butene / ethylene in the recycle gas stream under reaction equilibrium conditions on the density of the ethylene and butene polymer for the various catalyst types.

Giant. II illustrates a reaction system with a fluid bed for ² it gas-phase process in which the catalyst system can be used according to the invention.

It has now been found that the desired ethylene copolymers having a flow rate ratio of from 26 to 40, including limit values and a value of about 910 to 940 kg / m ^3, can be easily produced with relatively high productivity by a low pressure gas phase fluidized bed process. the monomer charge is polymerized under a specific set of operating conditions · listed -da ⁴ · le in the presence of a specific manner produced a highly active catalyst which is also described in more detail below. · in the catalysts of the invention are required to be in The concentration of comonomer present in the reactor was substantially lower to obtain a polymer of a certain density compared to processes using catalysts produced by the methods described in the earlier US patents. The co-comminuted catalyst systems produced according to the present invention can be directly fed into a polymerization reactor without having to be activated beforehand by the activation procedures disclosed in earlier US patents. This eliminates the catalyst reduction step. The catalyst systems of the present invention have a very high productivity in a low pressure gas phase polymerization in a fluidized bed reactor. In addition, the preparation of the co-comminuted catalyst systems of the present invention is simpler compared to the preparation of precursors described in earlier US patents.

The ethylene copolymers produced by the process f according to the invention have in many cases a broader molecular weight distribution

Mw / Mn and a higher melt flow rate ratio than copolymers prepared according to earlier US patents. This allows the resulting polymers to be used in a wider range of end applications. The copolymers produced according to the invention also have improved melt strength over ethylene copolymers prepared using the catalysts described in earlier US patents.

The process according to the invention makes it possible to produce copolymers containing, as the main molar part, ethylene (9090%) and, as the minor molar part (O10%), one or more C3 to C6 alpha olefins. The preferred α-olefins are propylene, 1-butene, 1-pentene, 1-hexane, 4-methyl-1-pentene and 1-octene.

The copolymers have a melt flow rate ratio of from about 26 to 40, preferably from about 28 to 35, including limit values. The melt flow rate ratio is another way of characterizing the molecular weight distribution of a polymer. The melt flow rate (MFR) of 26-40 (including cut-offs) corresponds to a Mw / Mn of between about 3.0 and 6.0, and an MFR of 28 to 35 (cut-offs) of * refers to a Mw ratio / Mn about 3.2 to 5.5.

The copolymers have a density of about 910 to 940, preferably 917 to 935 kg / m ³ , including limit values. In particular, the amount of the C3 to Cs comonomer to be copolymerized with ethylene can be controlled at a given melt flow index. In the absence of comonomer, ethylene would homopolymerize with the catalyst of the present invention to form homopolymers having a density of about 2: 0.96. Adding increasing amounts of comonomers to the polymers results in a gradual decrease in copolymer density. Under the same reaction conditions, the amount of each of the various C 3 to C 8 comonomers needed to achieve the same result varies from monomer to monomer.

Increasing the molar amount of comonomers in the series C3 > C4 > C5 < 6 >

The melt index of the polymers is a reflection of its molecular weight. Polymers with a relatively high molecular weight have. relatively low melt index. The ultra-high molecular weight ethylene polymers have a HLMI of about 0.0% ^. and very high molecular weight polymers have a melt flow index at a higher load of about 0.0 to about 1.0 g / 10 min. Such high molecular weight polymers are difficult to mold in conventional injection molding machines and sometimes even impossible. Copolymers' produced by the present invention, ^one the other hand in such a device can be readily molded. They have a melt flow index at normal load (MI) in the range! from about 1.0 to about 100, preferably from about 0.5 to 80, and a high load melt index (HLMI) of from about 11 to about 2000. The melt index of the polymers produced by the process of the invention is dependent on the combination temperature reaction at polymerization, copolymer density, and hydrogen / monomer ratio in the reaction system. The melt flow index increases with increasing polymerization temperature and / or decreasing polymer density and / or increasing hydrogen / monomer ratio. In addition to hydrogen, other chain transfer agents such as dialkyl zinc compounds can also be used to further increase the melt index of the copolymers.

The copolymers of the present invention contain from about 0.1 to about 0.3 C = C double bonds per 1000 carbon atoms.

The copolymers produced by the process of the present invention have a content of n-hexane extractables (at 50 ° C) of less than about 5% and preferably less than about 2% by weight.

The copolymers of the invention contain, as catalyst residues, of the order of 0 to 2 ppm Ti inclusive at a productivity of 500,000 or more and from 0 to 0.5 ppm Ti inclusive at a productivity of 2,000,000 or more. With respect to residues Cl, Br or I, the content of these elements in the copolymers depends on their content in the precursor. From the ratio of the amount of titanium to chlorine, bromine or iodine in the original precursor, the chlorine, bromine or iodine residue content can be calculated based on the known productivity value relative to the titanium residue itself. Many of the copolymers of the present invention, manufactured using only chlorine-containing catalyst system components, have a Cl / Tl ratio ranging from 80 to 350. At a Cl / Ti 80 ratio, the calculated chlorine residue is from> 0 to sl60 ppm at a productivity of 2500,000; from> 0 to 4040 ppm at a productivity of 22,000,000. In the method of the invention, copolymers are readily produced at a productivity of up to about 2,500,000.

The copolymers of the invention are granules of a substance having an average particle size of the order of about 0.127 to about 2.03 mm, and preferably about 0.5 to about 1 mm. The particle size is important for the easy fluidization of the polymer particles in the fluidized bed reactor as described below. The copolymers of the invention have a bulk density of from about 243.1 to about 421.5 kg / m ³ .

Compared to the homogeneous copolymers of USP No. 3,645,992, the copolymers of the invention are heterogeneous. Their melting point is about 121 ° C or higher.

Compared to copolymers produced using the catalyst systems disclosed in the earlier US applications, copolymers prepared using the catalysts of the present invention have a higher melt strength. Therefore, the copolymers produced according to the invention can be extruded into films at a substantially higher rate than the polymers of the earlier US patent applications. The copolymers of the present invention also provide greater bag stability in the production of films by blowing the extruded hose and cooling the resulting bag with high speed air as compared to the copolymers of the earlier applications.

The high performance catalyst used in the present invention is prepared by co-processing into a powder of at least one magnesium halide and a complex obtained by contacting at least one titanium compound with an ester, an ether, a ketone or an amine.

The magnesium compound has a structure corresponding to the general formula

MgXz where

X represents chlorine, bromine, iodine or a mixture thereof.

These magnesium compounds can be used singly or in combination and include compounds of the formulas MgCl 2, MgBr 2 and Mgl 2. Of the magnesium compounds, anhydrous magnesium chloride is particularly preferred.

The titanium compound has a structure corresponding to the general formula

Ti (OR) _and X _b where

R represents a C 1 -C 14 aliphatic or aromatic hydrocarbon radical or a radical of formula COR ‘, wherein R‘ represents a C 1 -C 14 aliphatic or aromatic hydrocarbon radical,

X is chlorine, bromine, iodine, or a mixture thereof, and is 0, 1 or 2, b is from 2 to 4 inclusive, wherein the sum of a + b is 3 or 4.

The titanium compounds can be used singly or in mixtures and include compounds of the formulas

TiCl3,

T1C14,

Ti (OCH 3) Cl 3,

Ti (OC6H5) Cl3,

Ti (OCOCH 3) Cl 3 and Ti (OCOC 6 H 5) Cl 3.

Esters, ethers, ketones and amines are understood to be compounds such as alkyl esters of aliphatic and aromatic carboxylic acids, aliphatic ethers, cyclic ethers and aliphatic ketones, di- and polyamino compounds such as 1,2,4-trimethylpiperazine, N, N, N ' , N'-tetramethylethylenediazine, N, N, N ', N'-tetraethylethylenediamine, 2-dimethylaminopyridine, N, N'-dimethylpiperazine, o-phenylenediamine, N, N'-dihenzylethylenediamine, N, N', N '' -dibenzylethylenediamine and 2,3, N, N'-dimethylnaphthylenediamine. Preferred esters and ethers are alkyl esters of C 1 to C 10 saturated aliphatic carboxylic acids, alkyl esters of C 7 to C 18 aromatic carboxylic acids, C 2 to C 6 and preferably C 3 to C 4 aliphatic ethers, C 3 to C 5 cyclic ethers and preferably C 4 cyclic mono- or diethers. The preferred amine is Ν, Ν, Ν ', Ν ¹ -tetraethylethylenediamine. Most preferred compounds are ethylanisate and tetrahydrofuran.

The magnesium compound is used in an amount of about 5 to 200 and preferably 10 to 80 moles per mole of the complex obtained by contacting the titanium compound with an ester, an ether, a ketone or an amine. Esters, ethers, ketones and amines are hereinafter referred to as electron donor compounds (ED compounds).

The activating compound has a structure corresponding to the general formula

Al (R ') _c X' _d H _e where

X ‘represents chlorine or a group of the formula OR‘ 'and each of the symbols

R 'and R' ', which are the same or different, represent a C 1 to C 14 saturated hydrocarbon radical, d is a number from 0 to 1.5, e is a number of 1 or 0, the sum of c + d + e being 3 .

The activating compounds may be used singly or in combination and exemplified by compounds of the formula

A1 (C2H5) 3

A1 (C ₂ H 5) 2c1,

Al (i-C4H9) 3,

Al2 (C2H5) 3Cl3,

Al (i-C 4 H 9) 2H,

Al (C6H13) 3,

Al (C8H17) 3,

A1 (C2 's) 2H and' A1 (C2H5) 2 '(OC2H5).

In the application of the catalysts used according to the invention, about 10 to 400 and preferably about 50 to 150 moles of activating compound are used per mole of titanium compound.

Solid inert diluents may be present in the mixture during co-processing of the catalyst to a powder. These diluents may be inorganic substances such as calcium carbonate, silicon and aluminum oxides which are substantially free of hydroxy groups and organic substances such as aromatic hydrocarbons. Diluents should be dry, ie they should not contain absorbed water. Drying is normally carried out by heating the diluent in a dry inert gas stream prior to use. When silica is used as a diluent, about 1 to 8% _by weight of one or more of the above-mentioned alkyl-aluminum compounds can be treated to remove the hydroxy groups. The diluents are added to the catalyst in amounts such that the weight ratio of diluent to magnesium halide in the catalyst is about 1: 1 to 5: 1.

The catalyst used in the process of the invention is prepared by first preparing a mixture of magnesium halides, a titanium compound and an ED compound as described above, and then treating the mixture with the above activator.

The mixture is prepared by co-treating the magnesium halide and the complex prepared by contacting the titanium compound with the ED compound to form a powder.

The powder co-processing may be carried out using conventional ball mills or other comminution equipment, for example vibratory mills. Powder treatment may be carried out either batchwise or continuously. It is usually carried out at room temperature, but it can also be carried out at lower or higher temperatures, for example 0 to 100 [ ^deg .] C. It can be carried out under a nitrogen or other inert gas such as argon or helium.

In the case where a rotary ball mill is used after processing into a powder, the following procedure is preferably used to obtain the desired product. 20 to 600 g of the components of the catalyst composition are introduced into a 4 liter porcelain ball mill which can accommodate 60-400 porcelain balls with a diameter of 19.05 mm. The components are then milled for about 1 to 500 hours or more, preferably at least 10 to 70 hours. Normally working at room temperature and no heating or cooling is required.

The magnesium halide is usually dried at 100 to 400 ° C under atmospheric or reduced pressure before use. It is preferred that the magnesium halide is best dehydrated. However, the presence of moisture can be tolerated to the extent that it does not impair the usefulness of the catalyst.

The complex of the titanium compound and the ED compound is prepared by dissolving the titanium compound in a saturated aliphatic hydrocarbon such as n-hexane. The ED compound is then dissolved in a saturated aliphatic hydrocarbon and the resulting solution is added to the dissolved titanium compound at 0 to 50 ° C. Typically, 0.5 to 1.0 mole of the titanium compound is used per mole of the ester ED compound.

The precipitate formed by the complex is then filtered off, washed and dried. Then, the magnesium halide and the titanium compound compound and the ED compound are co-formulated as above.

When the above procedure is followed, the catalyst composition has a composition corresponding to the following empirical formula

Mg _m Ti ₁ (OR) _n X _p [ED] _q where m represents a number greater than or equal to. 5 and less than or equal to 200, n is 0 or 1, p is greater than or equal to 10 and less than or equal to 400, q is greater than 0 and less than or equal to 3,

R represents a C 1 to C 14 aliphatic or aromatic hydrocarbon radical, or a radical of formula

COR ‘where

R 1 represents a C 1 to C 14 aliphatic or aromatic hydrocarbon radical,

X is chlorine, bromine, iodine or a mixture thereof;

ED is a liquid electron donor compound selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids, aliphatic ethers, cyclic ethers, aliphatic ketones, and di- and polyamino compounds.

The co-comminuted magnesium and titanium composition may be partially activated outside the polymerization reactor by the activating compound in the hydrocarbon slurry. Then, the hydrocarbon solvent is removed by drying and the partially activated powdered composition is fed into a polymerization reactor where activation is completed with an additional amount of activating compound. Partial activation of a composition comprising

- magnesium and titanium can also be carried out during powdering by adding the required amount of activator to the comminuted mixture. Preferably, however, the co-comminuted mixture is only fully activated in the polymerization reactor.

When the comminuted composition is partially activated outside the polymerization reactor, it is allowed to be partially reduced by reacting with an amount of activator so as to obtain a partially activated comminuted mixture in which the molar ratio of activator to titanium is about 1 to 35: 1. This partial reduction is preferably carried out in a ball mill or in a hydrocarbon solvent suspension, after which the resulting mixture is dried to remove the solvent, at a temperature of 20 to 80, preferably 50 to 70 ° C.

The resulting product is in the form of a particulate solid and can be readily fed into a polymerization reactor.

In order to convert the partially activated comminuted composition or unactivated comminuted composition to a form that is active in ethylene polymerization, an activator must be introduced into the polymerization reactor. This completely activates the comminuted composition in the polymerization reactor. The activator compound and the co-comminuted composition are preferably fed to the reactor via separate lines. The additional activating compound can be injected into the reactor as a solution in a hydrocarbon solvent such as isopentane, hexane or mineral oil. This solution typically contains about 2 to 30% by weight of the activating compound. The activator compound is added to the reactor in an amount such that a total activated Al / Ti molar ratio of about 10 to 400, and preferably about 50, comonomer is achieved in the reactor together with the amount of activator compound and titanium compound present as the partially activated precursor.

The molar% required in copolymers up to 150. The additional amount of activator compound introduced into the reactor reacts with the titanium compound and completes the activation of the titanium compound directly in the reactor.

In a continuous gas phase process such as the fluidized bed process described below, separate batches of partially activated or non-activated comminuted composition are continuously fed into the reactor during polymerization, while providing separate batches of the additional activating compound needed to complete the activating partially activated together. the comminuted composition or to activate the non-activated co-comminuted composition. This replaces the active sites of the catalyst that have been consumed during the reaction during the polymerization.

The polymerization is carried out by contacting the monomer stream in the gas phase, for example in the fluidized bed process described below, substantially in the absence of catalytic poisons such as moisture, oxygen, carbon monoxide, carbon dioxide and acetylene, with a catalytically effective amount of fully activated co-comminuted mixtures at pressure and temperature sufficient to initiate polymerization.

In order to achieve the desired density range of the copolymers, it is necessary to copolymerize with ethylene a sufficient amount of carbon chain comonomers of 3 or more carbon atoms so that the C3 to Cs content of the comonomers in the copolymers is 1.0 to 10 moles. %. The amount of comonomers required to achieve this result depends on the particular comonomers or comonomers used.

The following table lists several different comonomers that can be used for copolymerization with ethylene to produce polymers having a density within the desired range at any given melt index. The table shows both the amount of comonomers needed in the copolymers to achieve these properties and the relative molar concentration of comonomers relative to ethylene in the recycled monomer gas stream under reaction equilibrium conditions in the reactor.

Gas-phase C _x / C 2 molar ratio under equilibrium conditions

propylene 3.0 to 10 0.12 to 0.6 1-butene 2.5 to 7.0 0.12 to 0.46 1-pentene 2.0 to 6.0 0.09 to 0.3 1-hexene 1.0 to 5.0 0.05 to 0.13 1-okten 0.8 to 4.5 0.02 to 0.08

The fluidized bed reaction system that can be used in the process of the invention is illustrated in FIG. 2. The reactor 10 consists of a reaction zone 12 and a speed reducing zone 14.

Reaction zone 12 comprises a bed of growing polymer particles, formed polymer particles, and minor amounts of catalyst fluidized by the continuous flow of polymerizable and modifying gaseous components formed by the make-up gas and the gas recycled to the reaction zone. To maintain the fluidized bed in a fluidized state, the gas mass flow rate through the bed must be greater than the minimum flow rate required for fluidization. Preferably, a suitable gas mass flow rate through the bed is about 1.5 to about 10 times higher, preferably about 3 to 6 times higher than the minimum gas flow rate necessary for fluidization (Gmf). The Gmf designation for the minimum gas mass flow rate required to achieve fluidization was suggested by C. Y. Wen and Y.H. Yu, "Mechanics of Fluidization," Chemical Engineering Progress Symposium Series, Vol. 62, pp. 100-111 (1966).

It is important that the bed always contain particles that prevent "hot spots" and that trap and distribute the pulverulent catalyst in the reaction zone. Upon commencement of operation, a polymeric particle is usually introduced as a base into the reaction zone before the gas stream is introduced. The particles may be identical to the polymer formed or may be different. When different, they are drawn off with the resulting polymer particles as a leading product. Finally, the fluidized bed of the desired polymer particles displaces the starter bed. _

The partially activated or unactivated co-comminuted catalyst composition used in the fluidized bed is preferably stored in a standby container 32 under an atmosphere of an inert gas such as nitrogen or argon.

Fluidization is achieved by a high rate of gaseous recycle introduced into and through the bed, which is typically of the order of about 50 times higher than that of the make-up gas. The fluidized bed usually looks like a dense mass of moving particles flowing in the free vortex created by the passage of gas through the bed. The pressure drop across the bed is equal to or somewhat higher than the weight of the bed divided by the cross-section of the bed, so it is dependent on the reactor geometry.

The make-up gas is introduced into the bed at the same rate as the withdrawal rate of the polymer product particles. The make-up gas composition is determined by an analyzer 16 located above the bed. The gas analyzer determines the gas to be recycled and the composition of the make-up gas is adjusted accordingly to maintain the composition of the gaseous mixture substantially steady state in the reaction zone.

To ensure complete fluidization, the recycle gas and possibly part of the make-up gas is fed through the recycle line 22 through the feed 18 under the bed. Above the inlet 18 there is a gas distribution plate 20 which assists fluidization of the bed.

The portion of the gaseous stream that does not react in the bed forms recycled gas, which is discharged from the polymerization zone preferably by passing through a zone 14 located above the bed in which the velocity is reduced and the entrained particles fall back into the lot.

The recycle gas is then compressed in the pressurized chamber 25 and passed through a heat exchanger 26 where it is freed from the heat of reaction before returning to the bed. The bed temperature is kept constant at steady state conditions by dissipating the heat of reaction. There is no apparent temperature gradient at the top of the bed. A temperature gradient exists in the lower 152 to 304 mm bed, between the inlet gas temperature and the bed rest temperature. The recycle gas is fed to the bottom of the reactor via an inlet 18 and into the fluidized bed through a distributor plate 20. The compressor 25 may also be located downstream of the heat exchanger 28.

The distributor plate 20 plays an important role in the operation of the reactor. The fluidized bed contains both growing and formed polymer particles and catalyst particles. Since the polymer particles are hot and possibly active, they must be prevented from settling, since if any quiet mass were formed, the active catalyst contained in these particles could cause the reaction to continue, causing the particles to melt due to the heat generated. It is therefore important that diffuse recycle gas is passed through the bed at a rate sufficient to fluidize the bed particles. For this purpose, a separating plate 20 can be used and may be a sieve, a plate with slits, a perforated plate, a plate with caps (analogous to distillation column trays) and the like. All plate parts may be stationary or of a movable type such as plate as described in U.S. Patent No. 3,298,792. Whatever the design of the plate, the plate must disperse recycled gas between the particles at the bottom of the bed and keep the particles of the bed fluidized. The board also aims to support a quiet bed of resin particles when the reactor is not in operation. The movable portions of the plate may be used to extrude polymer particles retained on or within the plate.

Hydrogen can be used as the chain transfer agent in the polymerization according to the invention. The hydrogen / ethylene molar ratio that can be used is in the range of about 0 to about 2.0 moles of hydrogen per mole of monomer in the gas stream.

Any gas inert to the catalysts and reactants may also be present in the gas stream. The activator compound is preferably added to the reaction system downstream of the heat exchanger 26 (in terms of flow). Preferably, therefore, the activator is introduced into the recycle line from, for example, the container 27 through line 27A.

In addition to hydrogen, the compounds of the formula I can be used in addition to hydrogen as molecular weight control agents, i.e. as chain transfer agents.

Zn (R _a ) (R _b ) where

20S829

II

_And R; and R _b are the same or different C 1 -C 12 aliphatic or aromatic hydrocarbon radicals.

This further increases the melt index values of the copolymers produced. Lasio 0 to 10 can be added to the gas stream introduced into the reactor. And preferably about 20 to about 30 moles of zinc compound (calculated as Zi). titanium compound (calculated as: Ti). The zinc compound may be fed to the reactor preferably in the form of a dilute solution (concentration: 2 to 30% by weight) in a hydrocarbon solvent or in absorbed form in a solid diluent, such as silica of the type described above, amount from: about; 10 to 50 4 /: liinotnost. These substances tend to be; The zinc compound may be introduced alone or together with an additional activating compound which is also fed to the reactor from a metering device (not shown) which may be placed adjacent to the metering device 27.

Fluidized bed reactor; operating at a temperature below the sintering temperature of the polymer particles to prevent sintering of the particles. In the production of ethylene copolymers; The process according to the invention is preferably operated at a temperature of about 30 ° C to about 10 ° C (most preferably at a temperature of 75 ° C to 50 ° C), and temperatures of from 75 ° C to 95 ° C are used to produce products having a density of 9Mi. up to: 92 ° C / kg and temperatures of about 80 ° C to 100 ° C are used for the manufacture of products having a density of about ¹ ° C; .

The reactor with a phthalic charge is applied under pressure. to about 6.87 MPa and preferably a pressure of about 1.03 to about 2.40 inMPa while maintaining the pressure. works at higher * pressures in this; Range · easy to carry: · heat transfer; since the increase; pressure also results in an increase in the unit thermal gas flux volume.

Partially activated; a precursor or non-activated comminuted composition is injected into the bed at a rate; which; it is the same as the speed it consumes through the inlet 30 located above the manifold plate 24B. se. preferably. An important feature of the invention is that the catalyst is injected at a point above the manifold plate. Since the catalysts used according to the invention are highly active; · ^f may be given; iníjektovánř Í doc area below the distribution plate for ·· polymerization to begin 'this' místěpcož: could .nakonec: .vést to ucpáni.rozdělovači plate. Injection of the catalyst in the fluidized bed, in turn, aids in the distribution of the catalyst in the bed; and prevents the formation of sites with: a high catalyst concentration that could lead to hot spots. Catalyst dosing of the reactor above. bedding may result in excessive catalyst entrainment into the recycle line, where polymerization may also be initiated, which could eventually result in clogging of the line and heat exchanger.

For: introduction partially reduced or not reduced together. the comminuted catalyst composition into a bed. using a gas inert to the catalyst, such as nitrogen or argon;

Productivity: the bed is regulated by the catalyst injection rate. The bed productivity can be: simply increased by increasing the catalyst injection rate and reduced by reducing the catalyst injection rate. ;

Since any change in catalyst injection rate is due to; as a result of a change in the reaction heat evolution rate, the temperature of the recycle gas entering the reactor is adjusted up or down; to make-up & grain fast-spreading heat. This ensures maintenance. in fact; constant bed temperatures .; Jakufluidizavané; bed, so; cooling system recycled); of course, the gas must be equipped with: appropriate instruments for temperature detection? v; bed and cooling system so that the operator can appropriately adjust the temperature of the recycle gas r,

For ^- kombinaaeuprovozních certain conditions, the fluidized bed is maintained at substantially the same ívýšee: by žese .-. a part of the bed is drawn as a proidect at the same rate; is the rate of formation of polymer particles. product. Because: the rate of heat evolution is direct; proportionate to the product · ,; for the rate of formation of polymer particles at a constant rate; gas; determining the measurement of the gas temperature rise along the reactor (i.e., the temperature differences between the temperature of the incoming gas and the temperature of the outgoing gas).

The particles of the polystyrene product are preferably continuously collected. lead:; 34; near the manifold plate, 20: The particles are collected in the form of a suspension with a portion of the gaseous stream that seph. it ventilates before; depositing the particles to prevent further polymerization and baking before the particles reach the zone where they collect. The suspending gas can be either. As mentioned above, also used to transfer the product from one reactor to another.

The polymer product particles are expediently and preferably removed by means of two successive time-adjusted valves; 36; , 38 / among: whom; When the valve 3 is closed, the valve 3 is provided. 38, so that the gas / product mixture is allowed to pass into the vessel. Then, the valve 38 opens. to transfer the product to the outer insulation zone. The valve 38T then closes and is closed until the next product withdrawal. The vent gas containing unreacted monomers can be removed from zone 40 via line 41. Then it can be compressed in compressor 421 directly or through a purifier 43 and via line; 44’This 2Z gas recycle line: at the upstream (downstream) compressor of the 25 cycle.

Finally, the fluidized bed reactor is equipped with a suitable venting system that allows venting of the bed during start-up and shutdown. The reactor does not require the use of any mixing devices and / or wall scraping devices. The recycle gas pipes 22 and the devices located therein (compressor 25, heat exchanger 28) should have a smooth surface and should not contain unnecessary elements that could impede the smooth flow of gas.

The highly active catalyst system of the invention provides a fluidized bed product with an average particle size of about 0.127 to 2.03 mm, preferably between about 0.51 to 1.02 mm.

The feed monomer gas stream, optionally with inert gaseous diluents, is fed into the reactor at a rate to provide a space and time yield of about 32.4 to about 162.2 kg / hr / m ³ bed volume.

The term "crude resin or polymer" as used herein refers to a polymer in granular form as obtained from a polymerization reactor.

The following examples serve to illustrate the invention in more detail, but do not limit the scope of the invention in any way.

The properties of the polymers produced in the examples are determined by the following test methods:

Density

A test plate is made and tempered at 100 ^° C for 1 hour to approach equilibrium crystallinity. The density measurement is then performed in a density gradient column.

Melt Flow Index (MIJ)

ASTM D-1238-Condition E Measured at 190 ³ C data g for 10 minutes.

Flow rate (melt index at higher load J (HLMI)

ASTM-1238-Condition F. Measurements are performed using 10 times the load when measuring the melt index.

₌ Speed ratio _{via flash st} melt flow index

Productivity

The resin product sample is ashed and is determined by weight of ash as the ash is essentially a catalyst. The productivity is therefore expressed in kg of polymer produced per kg of total catalyst consumed. The amount of titanium, magnesium and chlorine in the ash is determined by elemental analysis.

Mean particle size

This property is calculated from sieve analysis data performed according to ASTM-D-1921, Method A using a sample> 500 g. The calculations are based on the weight fractions collected on the screens.

Density

The resin is poured into a 100 ml graduated cylinder through a funnel with a 9.5 mm stem diameter up to the 100 ml mark. Do not shake the cylinder during filling. The weight difference is determined by weighing.

Molecular weight distribution (Mw / Mn)

This property is measured by High Speed Tide Exclusion Chromatography using 10 µm silica packed columns. 1,2,4-Trichlorobenzene is used as solvent, the measurement is performed at 140 ° C, the flow rate is 1 ml / min and the detection is carried out by infrared radiation in the 2.42 μία region (C-H bond stretching).

Substances n-hexane extractables (FDA test used for polyethylene film intended to come into contact with food.) The sample film of thickness 0.038 mm and an area 1290 cm ² is cut into strips 2.54 cm by 15.24 cm and weighed to the nearest 0,1 mg. Place the strips in a flask and extract with 300 ml of n-hexane at 50 ± 1 ° C for 2 hours. The extract is then decanted into a balanced culture dish. After drying the extract in a vacuum desiccator, the culture dish is weighed to the nearest 0,1 mg. The amount of extract calculated on the original sample weight is then reported as the mass fraction of the substances extracted with n-hexane.

Unsaturation

Measurements are performed using an infrared spectrophotometer (Perkin Elmer Model 21). Resins of 0.635 mm thickness are made from the resin and serve as test specimens. Absorbance is measured at 10.35 / un in the case of transvinylidene unsaturation, at 11.0 / im in the case of terminal vinyl unsaturation and at 11.25 μτα. in the case of vinylidene unsaturation in the side chains. Absorbance per 1 mm of thickness of the compact is directly proportional to the multiple of the concentration of unsaturation and absorbency. Absorbency values are taken from R. J. de Kock et al., J. Polymer Science. Part B, 2, 339 (1964).

Examples

Preparation of a co-comminuted composition

Synthesize the titanium tetrachloride / ethylanisate complex by adding a 5% v / v hexane solution of ethylanisate to a 15% v / v solution of titanium tetrachloride in a 1: 1 molar ratio at 25 ° C. The bright orange solid complex that precipitated was washed several times with hexane and dried in a stream of nitrogen at 25 ° C.

In a similar way, TiCl 4 complexes were prepared. THF and TiCl 4. 2 THF using titanium tetrachloride and tetrahydrofuran (THF) in a 1: 1a molar ratio

I: 2. These complexes are yellow.

The anhydrous magnesium chloride is dried at 100-150 ° C in a vacuum oven for 12-72 hours.

500 g of magnesium chloride and 4 to 72 g of the titanium tetrachloride-electron donor compound are placed in a 4-liter ball mill which holds 400 porcelain spheres with a diameter of 19.05 mm. The ingredients are powdered under nitrogen for 10 to 72 hours at 25 ° C. The resulting comminuted composition contains 0.02 to 0.34 mmol Ti / g and has a Mg / Ti molar ratio of 27/1 to 523/1.

II Activation procedure

Advance

In this process, the desired weight of the co-comminuted composition is directly fed into the polymerization reactor. An activator (in these examples triethyl aluminum) in an inert hydrocarbon solvent (hexane) is injected into the reaction zone.

The co-comminuted composition may also be mixed with an inert carrier such as silica or polyethylene powder before being introduced into the polymerization reaction. The activator is then injected into the reaction zone.

Procedure B

According to this process, the co-comminuted composition is activated in several stages. The co-comminuted composition is only partially reduced prior to introduction into the polymerization reactor and the remainder of the reduction process is completed within the reactor.

The required weight of dry inert carrier is placed in a mixing vessel or drum. In the examples described herein, about 500 g of silica or about 1000 g of polyethylene carrier is used as the carrier. The inert carrier is then mixed with a sufficient amount of an anhydrous aliphatic hydrocarbon diluent, such as isopentane, to form a suspension. Usually about 4 to 7 ml of diluent per g of inert carrier is required. The desired weight of the co-comminuted composition is then placed in a mixing vessel and thoroughly mixed with the suspension. In the cases mentioned herein, about 50 to 300 g of co-comminuted composition containing 0.1 to 0.4 mmol of titanium per gram of co-comminuted composition are used to produce the catalysts.

The required amount of activator required to partially activate the co-comminuted composition is added to the contents of the mixing vessel. The amount of activator used is such that the Al / Ti ratio in the partially reduced co-comminuted composition is up to 10: 1. The activator is added to the mixing drum as a solution containing about 20% by weight of activator (in these examples triethyl aluminum as inert aliphatic hydrocarbon solvent). All of the operations described above are carried out at room temperature and at atmospheric pressure under an inert atmosphere. The activation is effected by thoroughly mixing and bringing the activator into contact with the co-comminuted composition.

The resulting suspension is dried under a stream of dry inert gas such as nitrogen or argon at atmospheric pressure and at 60 ^° C to remove the hydrocarbon diluent. This usually takes about 3 to 5 hours. The substance is in the form of a freely movable material consisting of a uniform mixture of the activated co-comminuted composition with an inert carrier. The dried, non-pyrophoric product is stored under an inert gas.

When the activator is injected into the polymerization system in the form of a dilute solution, a concentration of about 2 to 10% by weight is preferably used.

Regardless of how the activator is introduced into the polymerization reactor to complete activation of the co-comminuted composition, the activator is used in an amount such that the Al / Ti ratio in the polymerization reactor is maintained at about 8 to 400, and preferably about 10 to 100.

The silica is dried at least 600 ° C for at least 4 hours before use.

Procedure C

In this process, the partial activation of the catalyst is carried out by directly adding the activator to a ball mill or other mixing device before or during comminution. The resulting partially activated co-comminuted product can then be further used as in activation procedures A and B.

Example 1

Ethylene is copolymerized with 1-butene using a catalyst prepared from a 1: 1 titanium tetrachloride / ethylanisate complex containing a co-ground composition prepared as described above, activated in a polymerization reactor with triethyl aluminum as a 5% by weight solution in hexane. The catalyst obtained in the reactor has an Al / Ti molar ratio of about 160.

i / ^ 209 8 28

The polymerization reaction is carried out continuously in a fluidized bed reaction system for at least 1 hour after reaching equilibrium at a pressure of 2.06 MPa at a temperature of 85 ° C at a gas velocity of about five to six times Gmf and space / time yield 42.15 up to 76.19 kg / m ² / h. The reaction system described above is shown in FIG. 2. Its lower part is 3.05 m high and its internal diameter is 0.343 m. The upper part is 4 _; 88 m and its inner diameter is 0.597 m. Bed height is 1.52 to 2.44 m. Production speed is 8.63 to 12.26 kg / h.

Example 1 a d 2

Ethylene is copolymerized with 1-butene in the presence of a catalyst prepared from a complex of titanium tetrachloride and ethylanisate (1: 1) containing a co-milled composition prepared as above and mixed with 85.5% by weight of the silica described above. The activation is carried out in a polymerization reactor with triethyl aluminum as a 5% by weight hexane solution. The catalyst obtained has an Al / Ti molar ratio of 240.

The polymerization reaction was carried out as described in Example 1.

Examples 3 to 7

In this series of examples, ethylene is copolymerized with 1-butene in the presence of a catalyst prepared from a complex of titanium tetrachloride and ethylanisate (1: 1) containing a co-ground composition prepared as described above. Activation is performed by activating procedure B. The completion of the activation, together milled compositions is carried out in a polymerization reactor with triethyl aluminum in the form of a solution in hexane at concentration of 5 / _o by weight.

The polymerization reaction was carried out as described in Example 1.

The following table, relating to Examples 1 to 7, shows the different operating conditions used in these Examples, ie the type and amount of carrier (% by weight) used in the carrier mixture and co-milled composition, the Al / Ti ratio in the partially activated co-milled composition. the Al / Ti ratio maintained in the reactor, the polymerization temperature, the hydrogen / ethylene molar ratio, the 1-butene / ethylene molar ratio in the reactor, and the catalyst productivity. Table II lists the properties of the granular raw resins produced in Examples 1 to 7, i.e. density, melt flow rate, melt flow rate ratio, ash content (% by weight), titanium content (ppm), bulk (bulk density and mean particle size).

o ca 6ο ^η + ť 44 M> - 44 ø-i 2 O Φ s

P-1 Cti ca 'cd

N o

f = J

- φ 4 4D f-i '' cd

Xh oi ftž,, Έ fl 'fl O? £> £ t η> ω ω § B

I> ^ UO CD CO ΙΌ 1? ^ Rd CM * rd rd rd CM * rd

CM rd O what WHAT t> x CD WHAT O rd 00 O CD O what CM rd what rd CM o o WHAT* O* O O* O

in H cn Q M Η 1Ω cm ’φ τη cd o

C Η Η C \ \ C C C C CD CD CD

The reaction conditions in Examples 1 to 7 ca

4->

O cU a) ‘A • r ~,

A 3 ZXr <2 Ch 44 §2 a ^> ' ^ω <§ H £> dj +3 g 44 § a a> cD v-ι ΰ ΰ 2

P = 0 * X; > o 'Φ a

> ω ň

> φ from N

N o s 'CJ' CD

O

Ct

EN3>> Q * “” '4- <y w g t> n a 4-j O 4d ω a.

OF

Λ>.

AND

TJ cd o

I — I i — I

W lr-1 '

0-,

ID ID ID ID O ID CD 00 CO 00 CO CD CO CO o o o o o m

CD TJ1 00 Three CD 00 tv rd CM CM CM rH rd

R ^ CM ^ ^ ^ ^ ID ID ID ID ID ID ID ID ID ID))))))))))))))

> what 's> s' ^ »'cd'> ·.

4-> -t — i _ <4- »4-» 4— ^{1 -} '· - Λ r--II — I · (- * ^>o>o> y

XL)> CJ

S B '> 6 N S

OD Q) o CD Oj> P-M> &> t-1> | | > t-1

Article 44

4d £ £!

g 'g 43 £' g q> O> O ™ XD> O> O • r — I * r- | ~ «1—1> .- H ´ l“ H i — M r — I L> \ r — 1 i — l <-— (

Wc / j CD C / 5 CD

O

44 Λ 44 44 44 rd CM 00 (lf) CO o

»> - <ω>> £ X

Ό (/) Φ 'Cd £> O CO * dw, ^ω o ΖΓ β O

CD IS co m 00 CO. rd. WHAT. 05. rd. 05 /

τ-T o rd rd o rd θ

ΙΌ CO CO ΙΌ Ο CO Ο rd what. CM WHAT. cq. • Φ CM what cm Ή cm cm O ^ Φ rH r-1 what 00 CM CM CM WHAT CM CM CM WHAT

Properties of the polymers produced in Examples 1 to 7

3 = J S CO 'Φ. CD. WHAT. ^ Φ. WHAT. β Ρ- »θ 'O θ' rd θ 'θ' θ 'o

> β

O 4 ~ <

r — í ω cd o ft β

0 -M £ and rQ

About -

XJ y β

K * · 2sd o

Ph> 05 p

O

CL,> .3 s s β o 44 r ° M>> ΰ S β ‘β βϊ β

Μ 5, —I> Ο

Ό cd — — I λ:

> r — 4> in in o in I>>>> 05 05 05 05 05 05 05 05 05 05 05 05 05 05 05 CM 05 O. O. CD. O. O. O. ο θ 'o cd o Cd θ'

what. CD. what rd rd CD 05 / what cm σΓ O CD what φ what what CM WHAT CM what WHAT

H N LC O M cn_ co ~ co ~ ιτγ co mi co ^ r-f θ 'θ' θ 'ï θ' θ '

tx 05 ΙΌ 1 Ό CO CO 05 rd rd O O CD rd 05 / rd WHAT WHAT WHAT CM WHAT rd CD 05 / CD 05 / CD 05 / CD

CM C0 ΐ ΐ CO Ι>

Example 8

Ethylene is copolymerized with 1-butene using a catalyst prepared from a TiCl 3 / TiCl 2 complex. 2 THF, which contains a co-ground composition prepared as described above, activated in a polymerization reactor with triethyl aluminum as a 5% by weight solution in hexane. The catalyst obtained in the reactor has an Al / Ti molar ratio of about 150.

The polymerization reaction is carried out continuously in a fluidized bed reaction system for at least 1 hour after reaching equilibrium at 85 ° C and 1.37 MPa at a gas velocity of about five to six times the Gmf and space / time yield 50, 25 to 92.4 kg / m ³ / h. It is used in the reaction system described in Example 1. The bed height is 1525 mm. The production rate is 6.36 to 11.80 kg / h. Examples9 to 10

Ethylene is copolymerized with 1-butene using a catalyst prepared from a complex of titanium tetrachloride and tetrahydrofuran of the composition TlCl4.2 THF containing a co-comminuted composition prepared as described above and mixed with 66.7% by weight of the silica described above. The activation is carried out in a polymerization reactor with triethyl aluminum as a 5% by weight hexane solution. The catalyst obtained in the reactor has an Al / Ti molar ratio of 150.

The polymerization was carried out as described in Example 8.

Example 11

Ethylene is copolymerized with 1-byte using a catalyst prepared from a TiCl2 complex of titanium tetrachloride and tetrahydrofuran. THF comprising a co-milled composition prepared as described above and mixed with 75.0% by weight of the above; silicon dioxide. Activation is performed in a polymerization reactor with triethyl aluminum as a hexane solution at a concentration of _5/0 by weight. The catalyst obtained in the reactor has an Al / Ti molar ratio of 150.

The polymerization was carried out as described in Example 8.

Example 12

Ethylene is copolymerized with 1-butene using a catalyst prepared from a TiCl4 complex of titanium tetrachloride and tetrahydrofuran. THF containing the co-comminuted composition prepared as above, except that triisobutyl aluminum (TIBA) is added to the ball mill prior to grinding in an amount corresponding to an Al / Ti 3: 1 molar ratio. The resulting material is then mixed with polyethylene powder to form a composition containing 66.0% polyethylene powder. This mixture is then further activated in the polymerization reactor with triethyl aluminum as a 5% by weight hexane solution. The resulting fully activated catalyst obtained in the reactor has an Al / Ti molar ratio of 150.

The polymerization reaction is carried out continuously in a fluidized bed reaction system for at least 1 hour after reaching equilibrium at 85 ° C and 1.37 MPa at a gas velocity of about five to six times the Gmf value and space / time yield 50, 25 to 92.4 kg / m ³ / h. It is used in the reaction system described in Example 1. The bed height is 1525 mm. The production rate is 6.36 to 11.80 kg / h.

Example 13

Ethylene is copolymerized with 1-butene using a catalyst prepared from a co-comminuted composition prepared as described in Example 12 except that calcium carbonate is added to the ball mill in an amount corresponding to a weight ratio of CaCO3 / MgCl2 of 2: 1. it is then further activated in the polymerization reactor with triethyl aluminum as a 5% by weight hexane solution. The resulting activated catalyst obtained in the reactor has an Al / Ti molar ratio of 150.

The polymerization was carried out as described in Example 12.

Table III below, relating to Examples 8 to 13, lists the various operating conditions used in these examples, ie the type of titanium complex used in the comminuted composition, the Mg / Ti ratio, the Ti content, the amount of carrier used (% by weight), polymerization temperature. , a hydrogen / ethylene molar ratio, 1-butene / ethylene molar ratio, and catalyst productivity.

Table IV lists the properties of the granular crude resins produced in Examples 8-13, i.e. density, melt flow rate, melt flow rate ratio, ash content (% by weight), titanium content (ppm), bulk density and mean particle size.

cd>

£ d

O

Pd fe hh d bo £ o fe ·

4_, d 'cd f-i ω ω

2? With cd> »

W r-d

Cd O 55 co cd fe cd fe fe τ Í O r r-Γ CM ~ θ 'θ' d

P-l 'cd o

with

P-l> ω s

o fe d

ω

4- »d

n

K * “» rd co σ: lo h c in O) LO T-Η LO 7-1 CO CM CM fefeCO C j θ 'θ' θ 'θ' θ 'θ' ω j5i S 6 S

^Ft ο ο s ^ft >

t> CD CM KO CO in xfl CO LO * w tH cm CM CM fefeCM CM θ 'θ' θ 'θ' θ 'θ'

The reaction conditions in Examples 8 to 13 rG Ο and g cn g Λ rG 0

H 60

E ° cd f-d 0 B d

A 'cd

P-d-d> 03 E-10

dl ´ & 0 fe * fe R. what co ltT ccT what CD t> what '>> ·>' £> -> '£ * d' »d— * 4—>> O> o> o

CD CD CD>? -,> tn _n fe g Λ mgg> ca M ri4 tr, 'ca>N' á ' ₃ 'g>N>o>o> o — 1 · γ — 1 · (—dr —H r — dr ~ I ω ω ω b *! Ί> - | ^ * ·>

\ ι ο Η ο ο ο Ο _Λ θ 'θ' θ 'θ' θ 'θ' ιη ίο σ> ï ¹ ο CO ΙΌ ΙΌ ΙΌ τ-Ι CM CM CM ω

O ω £ o co n s o

W)

0 Ο Ο Ο 0 C0 o 'd \ Ctí' ta d 'q> ω d 2 a <

om ⁿ GR

00 Ο Ο 00 00> CD a

3 §g | fe 2 22 g fe fe fe fe CM CM CM CM CM CM ’’ Η Tt <Ttf I

O O o Η Η H fe fe fe fe fe Η EH H xfi Tfi xt <

qGo

HHH s

Ξ >>

d-j d

rO

O cn honors ό r-d r-d ω

\ r-d 'f * ’> t4> About

4i3

CD> <Λ 'Honored

Pd fe '£ >>

>

Ó d

CD i-I

Λ

-M

CD i> - »r — d

O fe

CO 03 O RH CM CO rH Η H rl fa fe LB H fe

Properties of the polymers produced in Examples 8 to 13

Example Density Flow Index Rate- Ash Content- Volume Ti Volume Mean _ _ Temperature (kg / m ³ ) melt flow rate (° / o (ppm) mass particle size Mw / Mn * melting (° C) bO

4tí a

-4— ¹ w

o a

• M o

and

Λ o

>

ea a

O rH i-I CO CM CM CM CM co ^ ioco | ιό l oo oo cd in cd

T-H rH CD and £ rH r-1 t — 1 r-1 rH O ιό σχ σγ co oo * θ 'co in co cm -Φ-Φ H co rH CO CO CO CO CM co

CO ΙΩ co in CD o r-o o o CM cm o

what about

CD o

CD CD's. o o o o r CD 'OO' in r-T r-cm rd cm CO o CO CO CO CO CO CM CM

CD 00 CO CM b> 00 CO '' Φ 'CO ^ CO ^ CD O Η Η Η Η H θ' CO θ '' Φ '-'Φ' r-Γ ι cm cm οο * φ CM CM CM CM rH CM O) O) O) 05) O)

CD O rH CM CO

Comparative Examples A to C

According to the processes disclosed in earlier U.S. Patent Nos. 892,322 and 012,720, a catalyst is prepared and copolymerized with ethylene with 1-butene.

I. Preparation of the impregnated precursor

A 121 L flask equipped with a mechanical stirrer was charged with 41.8 g (0.439 mol) of anhydrous magnesium chloride and 2.5 L of tetrahydrofuran (THF). 27.7 g (0.184 mol of titanium tetrachloride) are added dropwise to this mixture over a period of 0.5 hours.

To the above solution is added 500 g of porous silica and the mixture is stirred for 0.25 hours. The mixture was purged with nitrogen at 60 ^° C for about 3-5 hours. A dry, free-flowing powder is obtained having a particle size equal to the silica particles used.

II. Activation procedure

The desired weight of impregnated precursor and activating compound is placed in a mixing drum together with a sufficient amount of anhydrous aliphatic hydrocarbon diluent such as isopentane to form a suspension.

The activator compound and the precursor are used in amounts to obtain a partially activated precursor having an Al / Ti ratio greater than 0 but less than or equal to 10. A preferred ratio is 4 to 8: 1.

The suspension is stirred vigorously at room temperature and at atmospheric pressure for 0.25 to 0.5 hours. The resulting suspension is dried by selling dry inert gas such as nitrogen or argon at atmospheric pressure and at a temperature of 65 ± 10 ° C to remove the hydrocarbon diluent. This usually takes about 3 to 5 hours. The resulting catalyst is in the form of a partially activated precursor impregnated in the pores of silica. The substance is in the form of a freely movable powdered material. The particles correspond to the size and shape of the silica particles. The product is not pyrophoric when its aluminum alkyl content is not more than 10% by weight. It is kept under a dry inert gas such as nitrogen or argon until use. It is ready for introduction into the polymerization reactor where complete activation is then performed.

When an additional activating compound is introduced into the polymerization reactor to complete activation of the precursor, it is metered into the reactor as a dilute solution in a hydrocarbon solvent such as isopentane. These dilute solutions contain about 5 to about 30% by volume of the activating compound.

The activator compound is introduced into the polymerization reactor in an amount such that the Al / Ti ratio in the reactor is maintained at from 10 to 400: 1, preferably from 15 to 60: 1.

III. Polymerization

In each of the following Comparative Examples A to C, ethylene is copolymerized with 1-butene. The silica impregnated catalyst system used in Examples A and B contains 14.5 wt% precursor, and the silica impregnated catalyst system used in Example C contains 20.0 wt% precursor. The silica used as support for the catalyst of Example B is treated with triethyl aluminum before being used to prepare the support catalyst. In each of the examples, the precursor is partially activated with triethyl aluminum to obtain an alumina-precursor system with an Al / Ti molar ratio of 5 ± 1. The completion of the activation of the precursor composition in the polymerization reactor was accomplished with a 5 o / _o (j wt% solution of triethylaluminum in isopentane so as to obtain in the reactor completely activated catalyst with a molar ratio Al / Ti 25 to 30

Each of the reactions was carried out in the fluidized bed reaction system described above for at least 1 hour to reach equilibrium at 85 ° C and 2.06 MPa at a gas velocity of about three to six times the Gmf and the space-based yield. and a time of about 71.3 to 102.2 kg / m ³ / h.

Table V shows the 1-butene / ethylene molar ratio used in the examples, the melt flow index, the melt flow rate ratio, and the density of the polymers obtained. Comparative Examples D and G

According to the processes disclosed in the earlier U.S. Patent Nos. 892,325 and 014,414, a catalyst is prepared and copolymerized with ethylene with 1-butene.

I. Preparation of precursor

In a 50 liter flask equipped with a mechanical stirrer, 16.0 g (0.168 mol) of anhydrous magnesium chloride under nitrogen was mixed with 850 ml of pure tetrahydrofuran. The mixture was stirred at room temperature (about 25 ° C) and 13.05 g (0.069 mol) of titanium tetrachloride was added dropwise. At the end of the addition, the contents of the flask were refluxed for 1/2 hour to 1 hour to dissolve the solids. The system was cooled to room temperature and then 3 liters of n-hexane was slowly added over 1/4 hour. A yellow beer substance precipitates. The supernatant was decanted and the solid was washed three times with one liter of n-hexane three times. The solids are then filtered off and dried in a rotary evaporator at 40 to 60 ° C. 55 g of a solid precursor are obtained.

II. Activation procedure

Activation is carried out in such a way that the precursor is only partially activated before being introduced into the polymerization reactor and the reaction is completed in the reactor.

The required weight of dry inert carrier is placed in a mixing vessel or drum. In the examples described herein, about 500 g of silica is used as carrier. The inert carrier is then mixed with a sufficient amount of an anhydrous aliphatic hydrocarbon diluent, such as isopentane, to form a suspension. Usually about 4 to 7 ml of diluent per g of inert carrier is required. The desired weight of the precursor is then placed in a mixing vessel and thoroughly mixed with the suspension. In the examples given herein, about 80 to 135 g of precursor are used to produce catalysts, which contain 1 ± 0.1 mmol of titanium per gram of precursor.

The required amount of activator required to partially activate the precursor is added to the contents of the mixing vessel. An amount of activator is used such that the Al / Ti ratio in the partially reduced precursor is up to 10: 1, and preferably 4 to 8: 1. The activator is added to the mixing drum in the form of a solution containing about 20% by weight of the activator (in these examples triethyl aluminum) in an inert aliphatic hydrocarbon solvent (in these examples hexane). Activation is accomplished by thoroughly mixing and contacting the activator with the precursor. All operations described above are carried out at room temperature and at atmospheric pressure under an inert atmosphere.

The resulting suspension is dried under a stream of dry inert gas such as nitrogen or argon at atmospheric pressure and at a temperature of not more than 60 ° C to remove the hydrocarbon diluent. This usually takes about 3 to 5 hours. The substance is in the form of a free-flowing powdered material consisting of a uniform mixture of activated precursor with an inert carrier. The dried, non-pyrophoric product is stored under an inert gas.

When an additional activator is introduced into the polymerization reactor to complete activation of the precursor, it is first absorbed in an inert carrier, which is silica gel.

When the activator is absorbed in a silica gel carrier, the two materials are mixed together at a time containing about 4 ml of isopentane per gram of carrier. The resulting suspension is then dried for about 3-5 hours with a stream of nitrogen at atmospheric pressure at 65 ± 10 ° C to remove the hydrocarbon diluent.

When the activator is injected into the polymerization system in the form of a dilute solution, a concentration of about 5 to 10% by weight is preferably used.

The silica is dried at least 600 ° C for at least 4 hours before use.

III. Polymerization j. ,. _r - /

In each of these examples, ethylene is copolymerized with 1-butene using the catalyst prepared as described above. In all examples, the partially activated precursor has an Al / Ti molar ratio of 4.4 to 5.8. The activation of the precursor in the polymerization reactor is accomplished with triethylaluminum which is used either in the form of a 5% by weight isopentane solution (Examples D, E and Fj) or in adsorbed form on 50/50 silica (Example G) in such an amount, to obtain a fully activated catalyst with an Al / Ti molar ratio of about 29 to 140 in the reactor.

The catalyst in Example E contains 20.1% by weight of precursor and the Al / Ti molar ratio in the reactor is 88.3.

The catalyst in Example G contains 19.8% by weight of precursor and the Al / Ti molar ratio in the reactor is 26.7.

The catalyst in Example D contains 6.9% by weight of the precursor and the Al / Ti molar ratio in the reactor was 42.0.

The catalyst in Example F contains 8.3% by weight of precursor and the Al / Ti molar ratio in the reactor is 80.8.

Each of the reactions is carried out continuously in a fluidized bed reaction system for at least 1 hour after reaching equilibrium at a pressure of 2.06 MPa at a gas velocity of about five to six times the Gmf and a space and time yield of 48.7 to 97, 3 kg / m ⁱ² / h. The reaction system described above is used. The polymerization temperature is 85 ^° C (Examples D and F) or 90 ° C (Examples E and G).

Table V shows the 1-butene / ethylene molar ratio used in the examples and the melt flow index, the melt flow rate ratio, and the density of the polymers produced in these examples. By way of comparison, Table 8 also includes Examples 8, 11, 9 and 3 carried out by the method of the invention and described previously.

Example Molar ratio 1-butene / ethylene Density [kg / m ³ ] AND 0.472 920.8 (B) 0.448 923.8 C 0.402 927.8 D 0.480 919.0 E 0.450 925.0 F 0.396 929.0 G 0.350 931.0 8 0.298 921.0 11 0.251 923.0 9 0.259 926.8 3 0.210 930.5

Melt Flow Index The ratio of the flow rates [g / 10 min] of the melt

2.2 25.1 1,8 25.3 17.8 23.7 3.41 25.9 0.61 27.1 15.3 24.0 12.0 26.7 0.39 31.3 1.66 32.5 1.33 30.5 0.64 29.8

The data from Table V shows that when ethylene is copolymerized with the catalysts prepared by the procedures described in earlier U.S. patents (Examples A and G), high comonomer concentrations (high 1-butene / ethylene ratio) are required to produce copolymers with a certain density. When ethylene copolymerization using the catalysts prepared according to the invention (Examples 8, 11, 9 and 3), considerably lower comonomer concentrations are required to produce copolymers having a density comparable to that of the copolymers of the earlier US patents.

Figure 1 is a graphical representation of the effect of the 1-butene / ethylene molar ratio on polymer density for polymers produced using the catalysts of Examples A to G (line A) and polymers made using the catalysts of the present invention from Examples 12, 8, 11, 9 and 3 (line B).

The polymers listed in Table V have been processed into foils using extruded hose technology under comparable processing conditions. Polymers made using the catalysts of the present invention could be extruded at a higher rate than polymers made using the catalysts described in earlier U.S. patents. This phenomenon is explained by the fact that the polymers of the invention have a higher melt strength.

Claims (13)

A catalytic process for the production of ethylene copolymers using a titanium-containing catalyst at a productivity of at least 500,000 kilograms of polymer per kg of titanium in a reactor under a gas pressure of less than 6.87 MPa, the polymer being formed in granular form and having a density of about 910 to 940 kg / m ³ , including limit values, and a melt flow rate ratio of 26 to 40, including limit values, characterized in that the ethylene is copolymerized with at least one C 3 to C 8 olefin at a temperature of about 30 to 105 ° C, such that the batch contacts in the gas-phase reaction zone with particles of a catalytic system consisting of an activated co-comminuted composition, the composition of the composition corresponding to the empirical general formula Mg _m Ti ₁ (OR) _n X _p [ED] _q wherein m is greater than or equal to 5 and less than or equal to 200 n represents a number 0 or 1, p represents a number greater than or equal to 10 and less than or equal to 400 q represents a number greater than 0 and less. or equal to 3, R represents a C1 to Git aliphatic or aromatic hydrocarbon radical or a radical of formula VYNALEZU COR ‘where R ‘represents a C 1 -C 14 aliphatic or aromatic hydrocarbon radical, X is chlorine, bromine, iodine or a mixture thereof; ED is a liquid electron donor compound selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids aliphatic ethers, cyclic ethers, aliphatic ketones and di- and polyamino compounds, which composition is prepared by co-processing into a magnesium halide powder and a complex obtained by contacting a titanium compound of formula Ti (OR) _and X _b where R and X are as defined above, a is 0 or 1, b is 2 to 4 inclusive, and the sum of a + b is either 3 or 4, in contact with the above-mentioned electron donor compound ED, the co-comminuted composition being either partially activates> 0 to 35 moles of activating compound per mole of titanium compound in the co-milled composition, before dosing the activated co-milled composition into the reaction zone and then activating 210-400 moles of activating compound per mole of titanium compound in the co-milled composition or is completely activated in said reaction zone of 210 to 400 moles of activating compound per mole of titanium compound in a co-comminuted composition, wherein the activating compound is a compound of the general formula Al (.R ') _c X' _d H _e where X ‘represents chlorine or a group of the formula OR" ‘and each symbol R 'and R' ', which are the same or different, represent a C 1 -C 14 saturated hydrocarbon radical, d is a number from 0 to 1.5, e is a number of 1 or 0, the sum of c + d + e being 3 . 2. A process according to claim 1 wherein the magnesium halide is magnesium chloride. 3. The method of claim 2, wherein the electron donor compound comprises at least one ether. 4. The process of claim 3 wherein the ether is tetrahydrofuran. 5. The method of claim 2, wherein the electron donor compound comprises at least one ester. 6. The process of claim 5 wherein the ester is ethylanisate. 7. The method of claim 1, wherein the complex is a TiCU complex. ethylanisate. 8. The method of claim 1, wherein the complex is a TiCU complex. THF. 9. The method of claim 1, wherein the complex is a TiCU complex. 2THF. 10. The process of claim 1 wherein the co-grinding is carried out in the presence of an inert diluent. 11. The process of claim 10 wherein the inert diluent is calcium carbonate. 12. The process of claim 1 wherein a catalyst is added to the catalyst. 13. The method of claim 12 wherein the carrier is polyethylene. 2 sheets of drawings