JPH08134124A - Method of polymerizing olefin by using ziegler/natta catalyst - Google Patents

Abstract

PURPOSE: To provide a polymerization process wherein the activity of a catalyst for olefin polymerization can be markedly enhanced, and the catalyst, even when used in combination with a relatively large amount of a promoter, does not cause the formation of polymer agglomerates.

CONSTITUTION: There is provided a process for (co)polymerizing an olefin which comprises introducing as olefin, a titanium-based Ziegler-Natta catalyst, an organometallic promoter, and a halohydrocarbon compound in an amount effective to enhance the catalyst activity in (co)polymerization into a polymerization medium, wherein the above mentioned amount is such that the molar ratio of the halohydrocarbon to the titanium atoms is 0.01-0.1, or in a continuous (co)polymerization, it is 0.001-0.15. This process is especially useful for the continuous gas phase (co)polymerization of an olefin.

COPYRIGHT: (C)1996,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for polymerizing olefins in the presence of a Ziegler-Natta type catalyst, particularly as a catalyst activator in olefin polymerization in the presence of a Ziegler-Natta type titanium-based catalyst. It relates to the use of halogenated hydrocarbon compounds.

[0002]

BACKGROUND OF THE INVENTION It is known to polymerize olefins (eg ethylene) by gas phase polymerization, especially using Ziegler-Natta type catalysts and organometallic cocatalysts. When the catalyst is very active, especially when used in the presence of large amounts of cocatalyst, the formation of potentially significant polymer aggregates is observed.

Patent application EP-A-0 529 977 discloses the gas phase polymerization of ethylene carried out in the presence of halogenated hydrocarbon compounds using a Ziegler-Natta type catalyst containing titanium, which is ethane. Can be significantly reduced. Under the conditions used in the process disclosed by this European patent application, no significant change in the average activity of the catalyst is observed.

A process has now been found which can markedly increase the activity of the catalyst for the polymerization of olefins. When carrying out this method, the catalyst is very active and substantially no polymer aggregate formation is seen even when used in the presence of relatively large amounts of cocatalyst.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides one or more olefins comprising the introduction of an olefin, a Ziegler-Natta type titanium-based catalyst, an organometallic cocatalyst and a halogenated hydrocarbon compound into the polymerization medium. This is a (co) polymerization method, in which the (co) polymerization is continuously carried out and the halogenated hydrocarbon compound is introduced in an amount effective to increase the catalytic activity in the (co) polymerization. Such that the molar ratio of the amount of halogenated hydrocarbon compound to the amount of titanium introduced into the polymerization medium is in the range of 0.001 to 0.15, for example, greater than 0.001 and less than 0.15. It is characterized by doing.

According to another aspect, the present invention comprises one or more of the following: introducing into a polymerization medium an olefin, a Ziegler-Natta type titanium-based catalyst, an organometallic cocatalyst and a halogenated hydrocarbon compound. Regarding a (co) polymerization method of an olefin, this method introduces a halogenated hydrocarbon compound in an amount effective to increase the catalytic activity in the (co) polymerization, and this amount is compared with the amount of the halogenated hydrocarbon compound. The molar ratio to the amount of titanium introduced into the polymerization medium is 0.01 to 0.1, for example greater than 0.01 and 0.1.
It is characterized by making it smaller. Preferably the (co) polymerization is carried out continuously.

According to another embodiment, the invention further comprises catalytic activation during the (co) polymerization of one or more olefins in the presence of a Ziegler-Natta type titanium-based catalyst and an organometallic catalyst. It relates to the use of a halogenated hydrocarbon compound as an agent, wherein the halogenated hydrocarbon compound has a molar ratio between the amount of the halogenated hydrocarbon compound and the amount of titanium of 0.001 to 0.15, for example 0.0.
Used in an amount greater than 01 and less than 0.15. Preferably (co) polymerization is carried out continuously.

According to the method of the present invention, a halogenated hydrocarbon compound is used to increase the activity of a Ziegler-Natta type titanium-based catalyst. This activity indicates the amount of polymer produced under the given reaction conditions. For example, catalytic activity can be measured as the amount of polymer made at an olefin pressure of 0.1 MPa per hour of reaction per millimole of titanium.

The halogenated hydrocarbon compound can be a chlorinated or brominated hydrocarbon. This is, for example, in the general formula R—X [wherein R is 1 to 10, preferably 1
Represents an alkyl group having 4 to 4 carbon atoms, an aralkyl or aryl group having 6 to 14, preferably 6 to 10 carbon atoms, and X represents a halogen atom such as chlorine or bromine]. Can be a monohalogenated hydrocarbon. Further, the halogenated hydrocarbon compound is preferably 2 to 6, for example 2 to 4 halogen atoms such as chlorine or bromine and 1 to 14 halogen atoms.
It is also possible for the polyhalogenated hydrocarbons to have, for example 1 to 4 carbon atoms per molecule. Preferably, it is a mono- or poly-halogenated saturated hydrocarbon, such as the halogenated hydrocarbon compounds mentioned above, such as methylene chloride, chloroform, carbon tetrachloride, trichloro-1,1,1-ethane or dichloro1,2-. It can also be ethane. Chloroform is particularly often used.

The halogenated hydrocarbon compound is introduced into the polymerization medium neat or preferably diluted in a liquid hydrocarbon such as an alkane (eg isopentane, n-pentane, n-hexane or n-heptane). be able to.

The halogenated hydrocarbon compound very advantageously has a molar ratio of the amount of halogenated hydrocarbon to the amount of titanium introduced into the polymerization medium of 0.001 to 0.15, preferably 0.01 to. 0.1 or a range of 0.03 to 0.1,
More preferably 0.03 to 0.095, for example 0.0.
It is used in the (co) polymerization reaction in an amount such that it falls within the range of 31 to 0.091. Surprisingly, a significant increase in catalytic activity is seen when using these amounts of halogenated hydrocarbon compounds. Generally, this is at least 10%. In most cases this can be greater than 20%, or even greater than 100%. The increase in catalytic activity is seen especially when the (co) polymerization reaction is carried out continuously, especially in a phase polymerization process.

Continuous (co) polymerization of one or more olefins having 2 to 8 carbon atoms (eg ethylene or ethylene with at least one C ₃ -C ₈ olefin) is generally preferred for these olefins. A temperature lower than the melting point of the (co) polymer (for example, 30 to
120 ° C, preferably 50-110 ° C or 60-10
0 ° C.) and 0.1-5 MPa (preferably 0.5-4 M)
It is composed of continuous introduction into a polymerization medium under a pressure of Pa, for example 1 to 3 MPa. Furthermore, introducing the catalyst and the organometallic co-catalyst into the polymerization medium continuously or semi-continuously, for example intermittently, and discharging the produced polymer from the polymerization medium continuously or semi-continuously, for example intermittently. It consists of If necessary, a molecular weight regulator, for example hydrogen, can be continuously introduced into the polymerization medium. Preferably, the catalyst and the halogenated hydrocarbon compound are used to maintain the molar ratio of the amount of the halogenated hydrocarbon compound and the amount of titanium introduced to a substantially constant value selected within the above range, or the polymerization medium. Can be introduced inside.

The polymerization medium can be a liquid hydrocarbon diluent which forms a suspension with the catalyst and the (co) polymer. It is an alkane or a cycloalkane or a mixture of alkanes and cycloalkanes, for example 3 to 1
It can have 0, preferably 4 to 8 carbon atoms, for example n-hexane. In addition, it can be in the gas phase containing one or more olefins optionally mixed with hydrogen and an inert gas.

Preferably the polymerisation process is a continuous gas phase (co) of one or more olefins, eg having 2 to 8 carbon atoms (eg ethylene or ethylene and at least one C ₃ -C ₈ olefin). Polymerization.
In that case, the polymerization medium consists of an olefin stream flowing upwards through a stirred bed of fine (co) polymer, the heat of the (co) polymerization being removed by cooling of the olefin stream, which is then fed to the stirred bed. Circulate. The stirred bed can be a stirred bed, preferably a fluidized bed, in which the olefin stream is a fluidizing gas which keeps the fine (co) polymer in a fluidized state. The olefin stream comprises one or more olefins (eg ethylene or a mixture of ethylene and at least one C ₃ -C ₈ olefin), a molecular weight regulator (eg hydrogen) and an inert gas (eg nitrogen or at least one). C ₁ -C ₈ alkane, preferably used in an out with at least one C ₂ -C ₆ alkane).

In the present invention, particularly when carrying out continuous (co) polymerization of olefins, halogenated hydrocarbon compounds are preferably added to the polymerization medium, for example, 3 to 10 such as alkane, cycloalkane or a mixture thereof.
Are introduced continuously as a solution in a liquid hydrocarbon having 1 and preferably 4 to 8 carbon atoms. The halogenated hydrocarbon compound is 0.1 to 100% by weight, preferably 1 to 50% by weight in the liquid alkane or cycloalkane.
Can be used as a solution.

If the molar ratio between the amount of halogenated hydrocarbon compound and the amount of titanium introduced into the polymerization medium is too high, the activity of the catalyst is not significantly modified or especially in the case of continuous polymerization processes. It turned out to be substantially reduced. If this ratio is too low, no appreciable modification of the catalytic activity will be seen compared to the process carried out in the absence of halogenated hydrocarbon compounds.

Further, the halogenated hydrocarbon compound has a molar ratio of the amount of the halogenated hydrocarbon compound to the total amount of the cocatalyst introduced into the polymerization medium of 0.001 to 0.5, preferably 0.005. 0.25, especially 0.005-0.1
It can be used in an amount of 5, for example 0.01 to 0.15. Preferably the cocatalyst and the halogenated hydrocarbon compound are used so as to maintain the molar ratio between the amount of halogenated hydrocarbon compound and the amount of cocatalyst introduced at a substantially constant value selected within the above range, or It can be introduced into the polymerization medium.

The polymerization catalyst is a titanium-based catalyst, which means that it is substantially free of other transition metals, in particular essentially vanadium-free.

The catalyst may be a catalyst containing substantially titanium, halogen and magnesium atoms and optionally refractory oxides such as silica or alumina. It can be made by a method consisting of a reaction between magnesium metal, at least one halogenated hydrocarbon and at least one tetravalent titanium compound. A method of this kind is described, for example, in French Patent 2,093.
No. 9,311 and No. 2,116,698.

The catalyst may in particular comprise a particulate support based on refractory oxides such as silica and / or alumina. This type of catalyst comprises contacting a particulate support with (a) a dialkylmagnesium and optionally a trialkylaluminum, (b) a halogenated hydrocarbon, such as a monohalogenated hydrocarbon, and (c) a tetravalent titanium compound. It can be created by the method consisting of. A method of this kind is described in European patent application EP-
A-453,088.

The catalyst can also be a magnesium chloride support, in particular European patent application EP-A-336,54.
It may also contain a pre-activated support as described in No. 5. This type of catalyst has a magnesium chloride support (a) an organometallic compound that is a reducing agent for titanium,
It can be prepared by a method comprising contacting with (b) a tetravalent titanium compound, and (c) optionally one or more electron donor compounds. A method of this kind is described in French patent application FR-A-2,669,640.
No.

The catalyst can be used as a solid as it is or as a prepolymer, especially when used in gas phase polymerization. The prepolymer contacts the catalyst with one or more olefins having, for example, 2 to 8 carbon atoms (eg ethylene or a mixture of ethylene and C ₃ -C ₈ olefins) in the presence of an organometallic cocatalyst. It is obtained by In general, the resulting prepolymer contains 0.1 to 200 g, preferably 10 to 100 g of polymer per mmol of titanium.

The catalyst is used with an organometallic cocatalyst, which may be selected from organoaluminum, organomagnesium and organozinc compounds. In most cases, the organometallic cocatalyst is, for example, trimethylaluminium, triethylaluminum, alkylaluminium such as tri-n-octylaluminum or mixtures of these compounds.

According to the invention, the organometallic cocatalyst can be used in relatively large amounts, in particular the molar ratio of the total amount of organometallic cocatalyst to the amount of titanium introduced into the polymerization medium is 0.5.
-100, preferably 0.7-40, more preferably 1.2-20, for example 1.5-10.

The organometallic cocatalyst can be introduced into the polymerization medium, for example as a mixture with the catalyst in the prepolymer or separately from the catalyst, either continuously or semicontinuously, ie intermittently. According to the specified method, one part of the organometallic cocatalyst is introduced into the polymerization medium as a mixture with the catalyst and the other part is introduced separately from the catalyst. For example, the molar ratio of the amount of the organometallic promoter to the amount of titanium is 0.5 to 5,
A prepolymer containing an amount of the organometallic co-catalyst of preferably 1 to 4 is used, and the molar ratio of the amount of the co-catalyst added to the polymerization medium and the amount of titanium is 1 to 10 separately. Amounts of organometallic cocatalyst can be added.

The (co) polymerization reaction can be carried out as a suspension in liquid hydrocarbons. However, very advantageously according to the known method, in reactors incorporating a mechanically stirred bed and / or fluidized bed, in particular French patent 2,2
It is carried out in the vapor phase in the devices described in 07,145 and 2,335,526.

In the case of gas phase (co) polymerization, the olefin stream is such that the molar ratio of hydrogen to the amount of hydrogen and the total amount of olefin used is from 0.05 to 1, preferably from 0.15 to 0.5. It can be contained in an amount. However, this ratio is particularly high for (co) polymers with a high melt index, eg a melt index M higher than 50 g / 10 min.
It can be higher than 1 when producing (co) polymers of I _2.16 (measured at 190 ° C. under a load of _2.16 kg).

According to the process of the invention, optionally one or more α-olefins, eg having 3 to 8 carbon atoms, such as 1-butene, 1-hexene, 4-methyl-1-. Ethene (co) polymers containing pentene or 1-octene can be made. These (co) polymers can have densities in the range 0.965 to 0.910. The present invention is directed to ethylene and at least one α-olefin (eg, C ₃ -C).
₈ α-olefin), 0.948-0.
It is particularly advantageous for producing copolymers having a density in the range of 960 and a melt index MI _{2.16 in} the range of 2 to 25 g / 10 min. Furthermore, under good conditions, density in the range of 0.914-0.930 and 0.5-25g
It is also possible to produce ethylene copolymers with a Mettle Index MI _{2.16 in} the range of / 10 min.

The (co) polymer obtained by this method is lower than 15 ppm or lower than 10 ppm, usually lower than 5 ppm, eg 1-5 ppm.
Has a particularly low titanium content. Furthermore, these (co) polymers surprisingly have a high melt index compared to the (co) polymer obtained under the same conditions but in the absence of halogenated hydrocarbon compounds. In particular, the melt index measured at 190 ° C. under a load of 2.16 kg can be doubled. This melt index can change in parallel with the activity of the catalyst.

Furthermore, the (co) polymer obtained by the process of the present invention can have a lower content of soluble polymer than the (co) polymer obtained in the absence of halogenated hydrocarbon compounds. This result is particularly achieved with catalysts which contain substantially titanium, halogen and magnesium atoms, such as those produced by the reaction of magnesium metal with halogenated hydrocarbons and compounds of at least one tetravalent titanium (co ) Observed when obtaining the polymer. 20% reduction in soluble polymer content
Can be larger. According to the invention, the soluble polymer content of the (co) polymer is such that
-Measured after holding in hexane at 50 ° C for 2 hours. This content is expressed in% by weight.

Advantageously, the (co) polymer obtained by the process of the invention has a considerably reduced content of oligomers compared to the (co) polymer obtained in the absence of halogenated hydrocarbon compounds. You can also It has also been found that in most cases the molecular weight distribution of the (co) polymer is narrow compared to the (co) polymer obtained in the absence of halogenated hydrocarbon compounds.

[0032]

EXAMPLES The present invention will be further described below with reference to examples.

Example 1 (a) Preparation of catalyst 4.6 m ³ of n-hexane, 5.5 kg of iodine and 316
0 mol of magnesium, 29 mol of isobutanol and 6
0 mol of titanium tetra-n-propoxide and 60 mol of n-butyl chloride were introduced into a 10 m ³ reactor equipped with a mechanical stirrer rotating at 150 rpm. The reactor is then heated to a temperature of 85 ° C. until the reaction starts,
It was then heated to 80 ° C. At this temperature 400 mol of titanium tetrachloride and 340 mol of titanium tetra-n-propoxide were introduced into the reactor, then 4700 mol of n-butyl chloride were introduced over 240 minutes. The mixture thus obtained was then kept stirring at 80 ° C. for 2 hours.
The catalyst was thus obtained as a suspension in n-hexane.

(B) Preparation of prepolymer 500 liters of n-hexane, 4 mol of tri-n-octylaluminum and 2.4 mol of titanium in an amount containing the above-prepared catalyst were placed under a nitrogen atmosphere. 1.5m with stirring device maintained and rotating at 150 rpm
^It was introduced into a stainless steel reactor No. ³ and heated to 70 ° C. Then, hydrogen was introduced so as to obtain a partial pressure of 0.1 MPa, and further ethylene was introduced at a constant flow rate of 15 kg / h for 6 hours and 40 minutes. After this time, the reactor was degassed and its contents were transferred to a mechanical stirrer evaporator where n-hexane was removed by circulation of nitrogen heated to 70 ° C. 100 kg of prepolymer containing 40 g of polyethylene per mmol of titanium were thus obtained.

(C) Preparation of Copolymer of Ethylene and 1-Hexene The operation was carried out in the gas phase polymerization reactor (1) as shown in FIG. 1, which was substantially 75 cm in diameter and high in height. 6m
Of the vertical cylinder (2) and the desorption chamber (3) above it, the chamber being provided with a fluidization grid (4) at its lower part and the top of the desorption chamber being located below the fluidization grid. A circulation conduit (5) connected to the lower part of the reactor is provided, and a heat exchanger (6), a compressor (7), ethylene (8), 1-
Supply conduits for hexane (9) and hydrogen (10) were provided. Furthermore, the reactor was equipped with a feed conduit (11) for the prepolymer and a conduit (12) for withdrawing the copolymer.

The reactor contains a fluidized bed of the particles of polymer produced, which has a height of 2.5 m and is passed through a stream of the reaction gas mixture, which stream is 45 c.
It had an upward velocity of m / s, an absolute pressure of 1.7 MPa and a temperature of 80 ° C. measured at the outlet of the desorption chamber.

The reaction gas mixture comprises by volume 15% ethylene, 2.6% 1-hexene, 3.5% hydrogen and 78.9.
% Nitrogen.

The prepolymer prepared above was fed to the reactor at a rate of 650 g / h. Further, triethylaluminum was separately fed at a rate of 40 mmol / hour. Further, chloroform was continuously fed at a rate of 0.7 mmol / hour. The molar ratio between the amount of chloroform and the amount of titanium introduced into the reactor was therefore 0.043.

Under these conditions, the agglomerate-free ethylene polymer was withdrawn at a rate of 62 kg / h, this polymer having a density of 0.918, a titanium content of 12 ppm and a melt index MI _2.16 of 1.3 g / 10 min. And additionally contained about 10% by weight of 1-hexene. The catalytic activity is 0.1 MPa of ethylene pressure (g / mM / h / 0.1M) per 1 mmol of titanium per 1 hour of reaction.
It was 310 g of polymer in Pa).

Example 2 (Comparative) Preparation of Copolymer of Ethylene and 1-Hexene The procedure was exactly the same as in Example 1 (c),
However, chloroform was not used in the copolymerization reaction. Under these conditions, the catalytic activity is 240 g / mM / h /
It was 0.1 MPa.

Example 3 (a) Preparation of catalyst The procedure was exactly the same as in Example 1, except that 48 mol of dimethylformamide were introduced into the mixture obtained at the end of the preparation and stirred at 80 ° C. did. The mixture thus obtained was then kept stirring at 80 ° C. for 2 hours. After this time, the mixture was cooled to 20 ° C., thus the catalyst was obtained as a suspension in n-hexane.

(B) Preparation of prepolymer The procedure was exactly the same as in Example 1, except that 3 moles of tri-n-octylaluminum and 2.5 moles of titanium were included in the above procedure. A catalyst was used.

(C) Preparation of a copolymer of ethylene and 1-butene The procedure was exactly the same as in Example 1, except that a gas phase polymerization reactor with a diameter of 90 cm and 380 kg was used.
Fluidized bed of polymer, and an upward velocity of 37 cm / s,
4 at absolute pressure of 1.9 MPa, temperature and volume of 94 ° C
7.4% ethylene, 2.3% 1-butene, 29.4
% Of hydrogen and a flow of reaction gas mixture having a composition of 20.9% nitrogen.

The prepolymer prepared above was fed to the reactor at a rate of 1200 g / h. Further, chloroform was continuously fed in such a ratio that the molar ratio between the amount of chloroform and the amount of titanium introduced into the reactor changed as shown in Table 1 below.

[0045]

[Table 1] Note (I) ppm: ppm by weight.

The analysis of the tests shown in Table 1 shows that the catalytic activity in tests B, C and D was substantially increased (about + 30%) compared to test A without chloroform (comparative). The catalytic activity was dramatically reduced in tests E (comparative) and F (comparative). Figure 2 shows the catalytic activity (g / mM / h / 0.1M) against the molar ratio of chloroform and titanium.
(Represented by Pa), showing tests AF.

Example 4 (a) Preparation of catalyst The procedure was exactly the same as in Example 3.

(B) Preparation of prepolymer The procedure was exactly the same as in Example 3, except that 4 mol of tri-n-octylaluminum was used.

(C) Production of polyethylene The procedure was exactly the same as in Example 3, except that 38.9% by volume of ethylene and 42.8% of hydrogen were added.
A reaction gas mixture having a composition of 8.3% nitrogen was used.

The reactor was charged with the prepolymer prepared above at a rate of 960 g / h. Furthermore, the molar ratio between the amount of chloroform and the amount of titanium introduced into the reactor is shown in Table 2.
Chloroform was continuously fed at a changing ratio as shown in.

[0051]

[Table 2] Note (I) ppm: ppm by weight.

The analysis of the tests shown in Table 2 shows that the catalytic activity in tests H, I and J is substantially increased (61% to 97%) compared to test G (comparative) without chloroform.
%)).

Example 5 (a) Preparation of catalyst The procedure was exactly the same as in Example 1 (a).

(B) Preparation of prepolymer 500 l of n-hexane and 2.5 mol of tri-n
Octylaluminum and an amount of the catalyst prepared above containing 2.5 mol of titanium were maintained under a nitrogen atmosphere, provided with a stirrer rotating at 150 rpm and heated to 70 ° C. It was introduced into a 0.5 m ³ stainless steel reactor. Then, hydrogen was introduced to obtain a partial pressure of 0.1 MPa, and ethylene was introduced at a constant flow rate of 15 kg / h for 5 hours and 50 minutes. After this time, the reactor was degassed, its contents were transferred to a mechanical stir evaporator and the n-hexane was removed by circulation of nitrogen heated to 70 ° C. 87.5 kg of prepolymer containing 35 g of polyethylene per mmol of titanium were thus obtained.

(C) Preparation of copolymer of ethylene and 1-hexene The operation was carried out in the same reactor as in Example 1 (c). The reactor contains a fluidized bed of particles of polymer produced, which has a height of 2.5 m and is passed through a stream of the reaction gas mixture, which stream has an upward velocity of 45 cm / s and 1. It had an absolute pressure of 6 MPa and a temperature of 80 ° C. measured at the outlet of the desorption chamber.

The reaction gas mixture contained by volume 37% ethylene, 7.0% 1-hexene, 6.3% hydrogen and 49.7.
% Nitrogen.

The prepolymer prepared above was fed to the reactor at a rate of 350 g / h. In addition, triethylaluminum was separately fed at a rate of 20 mmol / h. Further, chloroform was continuously fed at a rate of 0.5 mmol / hour. The molar ratio between the amount of chloroform and the amount of titanium introduced into the reactor was therefore 0.05.

Under these conditions, an agglomerate-free ethylene polymer was withdrawn at a rate of 80 kg / h, this polymer having a density of 0.9175, a titanium content of 6 ppm and a melt index MI _2.16 of 0.8 g / 10 min. It had a solubles content of 1.6% and contained about 10% by weight of 1-hexene. Catalyst activity is 450g / m
It was M / h / 0.1 MPa.

Example 6 (Comparative) The procedure for preparing a copolymer of ethylene and 1-hexene was carried out exactly as in Example 5 (c), except that
However, chloroform was not used. Under these conditions, the catalytic activity was 240 g / mM / h / 0.1 MPa. The polymer obtained has a melt index MI _2.16 of 0.55 g / 10 min and a content of soluble substances of 2.9%.

Example 7 (a) Preparation of catalyst In a fluidized bed reactor, microsphere silica powder sold by Joseph Crossfield & Sons (UK) as "ES70" R®, It was subjected to a heat treatment at 870 ° C. under a stream of nitrogen for 12 hours. After this time, the silica powder obtained was cooled to room temperature (20 ° C.) and kept under a nitrogen atmosphere.

Into a 240 liter stainless steel reactor equipped with a stirrer rotating at 166 rpm, 20 kg of the silica powder prepared above and n-hexane were introduced at room temperature to prepare 110 liter of suspension. Was generated, and then 16 mol of hexamethyldisilazane was introduced at 50 ° C. The suspension thus obtained was kept stirring at 80 ° C. for 4 hours. It contains solids, 1 each
It was washed 5 times with 30 liters of n-hexane at 50 ° C.

Then, 30 mol of dibutylmagnesium was introduced into the reactor at 50 ° C. for 2 hours. The suspension thus obtained was kept stirring at 50 ° C. for 1 hour. It contained a solid product with 1.5 mmol magnesium per gram silica.

To a reactor containing the solid product in suspension in n-hexane heated to 50 ° C. was introduced 60 mol of t-butyl chloride over a period of 2 hours. After this time, the resulting suspension was stirred at 50 ° C. for 1 hour. It contained a solid product, which was washed three times with 130 l of n-hexane each at 50 ° C.

Into the reactor maintained at 50 ° C. was introduced 6 mol of triethyl orthoacetate. 50 of the resulting suspension
Stirring was continued at 0 ° C. for another hour.

Then 12 mol of trimethylaluminium were introduced into the reactor at 50 ° C. 8 of the resulting suspension
Stirring was continued at 0 ° C. for 2 hours.

Into the reactor cooled to 50 ° C., 3 mol of titanium tetra-n-butoxide and 3 mol of titanium tetrachloride were introduced. The resulting suspension was kept stirring at 80 ° C. for 2 hours and then cooled to 20 ° C. It contained a solid catalyst, which was washed 5 times with 130 l of n-hexane each at 20 ° C. This catalyst is 1g silica
Each contained 1.5 mmol magnesium, 3 mmol chlorine and 0.3 mmol titanium.

(B) Preparation of prepolymer Shell company (Netherlands) containing 450 liters of n-hexane and 0.55% by weight of chromium and calcium.
15g antistatic composition sold by
3 "R and 1 m ³ of stainless steel fitted with a stirrer rotating at 140 revolutions per minute of the catalyst prepared above in an amount containing 2 moles of titanium and 8 moles of tri-n-octylaluminum. It was introduced into the reactor. Hydrogen was introduced into the catalyst suspension heated to 70 ° C. so as to obtain a partial pressure of 0.1 MPa, and ethylene was introduced at a constant flow rate of 15 kg / h for 5 hours and 20 minutes. After this time, the resulting prelimer suspension was transferred to a mechanical stir evaporator where n-hexane was removed by circulation of nitrogen heated to 70 ° C. 80 kg of prepolymer are thus obtained, which has an average diameter of 90 μm and 0.45 g / c.
with a bulk density of m ³ .

(C) Preparation of Copolymer of Ethylene and 1-Hexene The procedure was exactly the same as in Example 1, except that the prepolymer prepared above and the volume of 30% ethylene, 4.2% 1-hexene, 6% hydrogen and 59.
A reaction gas mixture of 8% and nitrogen was used.

The prepolymer prepared above was fed to the reactor at a rate of 160 g / h. Trimethylaluminum was separately fed at a rate of 22.6 mmol / h. Further, chloroform was continuously fed at such a rate that the molar ratio between the amount of chloroform and the amount of titanium introduced into the reactor was 0.08.

Under these conditions, the agglomerate-free copolymer was withdrawn at a rate of 85 kg / h, the copolymer having a density of 0.917, a melt index MI _2.16 of 1.0 g / 10 min and an average diameter of 920 μm. did.
The catalyst activity was 1160 g of polymer (g / g / mol of titanium / hour of reaction) at ethylene pressure of 0.1 MPa.
(mM / h / 0.1 MPa).

Example 8 (Comparison) The production of a copolymer of ethylene and 1-hexene was carried out exactly as in Example 7, but without the use of chloroform. Under these conditions, the catalytic activity was 820 g / mM / h / 0.1 MPa. This copolymer has a density of 0.919 and 1.1 g / 10 min
It has a melt index MI of _2.16 and an average diameter of 790 μm.

Example 9 (a) Preparation of magnesium chloride support 8.1 liters (40 mmol) of diisoamyl ether (DIAE) at room temperature (20 ° C.) under a nitrogen atmosphere were added.
With a stirring device that rotates at 150 rpm
A 300 liter stainless steel reactor containing mol dibutyl magnesium as a solution in 133 liter n-hexane was introduced. The reactor was maintained at 30 ° C. and 19.3 liters (176 mol) of t-butyl chloride was introduced over 12 hours. The mixture was then kept stirring at 30 ° C. for 2 hours. The solid products obtained were each washed with 130 l of n-hexane 7 times at 30 ° C. 80 mol of magnesium chloride are thus obtained as spherical particles, which have an average diameter of 26 μm, a particle size distribution Dm / Dn of 1.5 and a DI of 0.103.
It had an AE / Mg molar ratio and a Cl / Mg molar ratio of 2.17.

(B) Preparation of catalyst 110 liters of n-hexane containing 70 mol of the magnesium chloride prepared above was placed in a nitrogen atmosphere under a nitrogen atmosphere at a speed of 160 rpm and equipped with a stirrer 3.
It was introduced into a 00 liter stainless steel reactor. The reactor was heated to 70 ° C. for 1 hour. The obtained solid was washed twice with 130 liters of n-hexane each at 70 ° C, and then twice with each 130 liters of n-hexane at 25 ° C. At a reaction temperature of 25 ° C,
18.9 liters of n-hexane containing 35 mol of ethanol and 7 mol of triethyl orthoacetate were introduced into it. The reactor was then kept stirring at a temperature of 25 ° C. for 1 hour. After this time, the solid products obtained were each treated with 130 l of n-hexane at 25 ° C.
After washing 4 times with, the volume of the suspension was returned to 110 liters by removing 1 part of n-hexane. The reactor was then heated to 50 ° C. and 80 liters of n-hexane containing 70 mol of triethylaluminum was introduced over 1 hour. Maintain agitation for 1 hour and 50
After continuing to maintain the temperature of ° C, the solid products obtained were each mixed with 130 liters of n-hexane at 50 ° C.
Washed once with 130 liters of n-hexane for 6 times at 25 ° C. and the volume of the suspension was returned to 110 liters by removal of 1 part of n-hexane. 32 liters of n-hexane containing a mixture of 7 moles of titanium tetrachloride and 7 moles of titanium tetra-n-propoxide were then introduced into the reactor over 1 hour. The reactor was then kept stirring at 80 ° C. for 1 hour. After this time, the solid product obtained was treated twice with 130 l of n-hexane at 80 ° C. twice and then with 130 l of n-hexane each at 50 ° C.
25 ° C. once with 130 liters of n-hexane
It was washed 5 times. A catalyst having the following properties was thus obtained: titanium / magnesium molar ratio 0.109 aluminum / magnesium molar ratio 0.007 trivalent titanium / total titanium molar ratio 0.45 chlorine / magnesium molar ratio 2. 25 DIAE / magnesium molar ratio 0

(C) Preparation of prepolymer 450 liters of n-hexane and 0.55% by weight of chromium and calcium were placed in a 1 m ³ stainless steel reactor equipped with a jacket and a stirrer rotating at 140 rpm. Sold by Shell GmbH (Netherlands) containing 1
3. An amount of the above-prepared catalyst corresponding to 5 g of antistatic composition "ASA-3" R and 3 mol of titanium and finally 4.
8 mol of tri-n-octylaluminum were introduced successively. The catalyst suspension thus obtained is heated to 70 ° C., then hydrogen is introduced over a period of 6 hours so as to obtain a partial pressure of 0.1 MPa, and a further 70% by volume of ethylene and 3
A mixture containing 0% hydrogen was introduced at a constant rate of 20 kg / h. After the prepolymerization reaction, the obtained prepolymer suspension was cooled to 60 ° C. 120 kg of prepolymer with excellent dry flow properties, weight average diameter of 80 μm and bulk density of 0.49 g / ml were recovered.

(D) Copolymerization of ethylene and 1-hexene 100 kg of anhydrous polyethylene powder was placed under a nitrogen atmosphere.
It was introduced into a 75 cm diameter reactor containing a 75 cm diameter fluidized bed as the polymer charge obtained from the previous reaction. A gas mixture heated to 80 ° C. was then introduced, the mixture consisting of hydrogen, ethylene, 1-hexene and nitrogen and injected at an upward velocity of 44 cm / s. The partial pressure of each component in this mixture is as follows: hydrogen 0.072 MPa ethylene 0.425 MPa 1-hexene 0.064 MPa nitrogen 1.140 MPa.

The prepolymer obtained above was then introduced into this reactor at a rate of 120 g / h and triethylaluminum at a rate of 22 mmol / h. Chloroform was continuously introduced at a rate of 0.24 mmol / hr. As a result, the molar ratio between the amount of chloroform and the amount of titanium introduced into the reactor was 0.08.
The catalytic activity was 1070 g / mM / h / 0.1 MPa, and after stabilizing the polymerization conditions, a copolymer powder having the following properties was obtained at a rate of 70 kg / h: Bulk density: 0.37 g / cm ³ melt Index MI _2.16 : 0.9 g / 10 min Flow parameter n: 1.5 Density: 0.918 Weight average diameter: 700 μm Content of fines having a diameter of less than 125 μm: 0.1
Weight% Titanium content: 2 ppm Width of molecular weight distribution: 3.9

Example 10 (Comparative) The copolymerization operation of ethylene and 1-hexene was carried out exactly as in Example 9 (d), except that
However, chloroform was not used in the copolymerization reaction.
Under these conditions, the catalytic activity was 720 g / mM / h / 0.
It was 1 MPa.

[0078]

According to the method of the present invention, one or more α-olefins having, for example, 3 to 8 carbon atoms, such as 1-butene, 1-hexene and 4-methyl-, are optionally used. Ethylene (co) polymers containing 1-pentene or 1-octene can be made. These (co) polymers can have densities in the range 0.965 to 0.910. The present invention is directed to ethylene and at least one α-olefin (eg, C ₃ -C).
₈ α-olefin), 0.948-0.
It is particularly advantageous for producing copolymers having a density in the range of 960 and a melt index MI _{2.16 in} the range of 2 to 25 g / 10 min. Furthermore, under good conditions, density in the range of 0.914-0.930 and 0.5-25g
It is also possible to produce ethylene copolymers with a Mettle Index MI _{2.16 in} the range of / 10 min.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a fluidized bed reactor for performing gas phase (co) polymerization of ethylene according to Example 1 of the present invention.

FIG. 2 is a graph showing the catalyst activity in the molar ratio of chloroform and titanium introduced into the polymerization medium (Tests A to F in Example 3 of the present invention). FIG. 4 is a characteristic curve diagram of (produced as g number of (co) polymer).

[Explanation of symbols]

 1 Gas Phase Polymerization Reactor 3 Desorption Chamber 4 Fluidization Grid 5 Circulation Pipeline 6 Heat Exchanger 7 Compressor

Claims (13)

[Claims] 1. An olefin and a Ziegler.
In a method of (co) polymerizing one or more olefins, which comprises introducing a Natta type titanium-based catalyst, an organometallic co-catalyst and a halogenated hydrocarbon compound, the (co) polymerization is carried out continuously and The halogenated hydrocarbon compound is introduced in an amount effective to increase the catalytic activity in the (co) polymerization, and this amount is adjusted between the amount of the halogenated hydrocarbon compound and the amount of titanium introduced into the polymerization medium. A method of (co) polymerizing one or more olefins, characterized in that the molar ratio is greater than 0.001 and less than 0.15. 2. An olefin and a Ziegler.
A (co) polymerization of a halogenated hydrocarbon compound in a (co) polymerization method of one or more olefins which comprises introducing a Natta type titanium based catalyst, an organometallic co-catalyst and a halogenated hydrocarbon compound. Is introduced in an amount effective for increasing the catalytic activity, and the molar ratio of the amount of the halogenated hydrocarbon compound to the amount of titanium introduced into the polymerization medium is more than 0.01 and 0. 1. A method for (co) polymerizing one or more olefins, characterized in that it is less than 1. 3. The method according to claim 2, wherein the (co) polymerization is carried out continuously. 4. The method according to claim 1, wherein the halogenated hydrocarbon compound is continuously introduced into the polymerization medium. 5. The method according to claim 1, wherein the (co) polymerization is carried out in the gas phase. 6. The halogenated hydrocarbon compound is adjusted so that the molar ratio of the amount of the halogenated hydrocarbon compound to the amount of titanium introduced into the polymerization medium is in the range of 0.031 to 0.091. The method according to any one of claims 1 to 5, wherein the method is introduced as a method. 7. An organometallic cocatalyst such that the molar ratio between the amount of halogenated hydrocarbon compound and the amount of organometallic cocatalyst introduced into the polymerization medium is in the range of 0.001 to 0.5. The method according to claim 1, wherein the method is introduced in an amount. 8. The method according to claim 1, wherein the halogenated hydrocarbon compound is a mono- or poly-halogenated saturated hydrocarbon. 9. The halogenated hydrocarbon is selected from the group consisting of methylene chloride, chloroform, carbon tetrachloride, trichloro-1,1,1-ethane and dichloro-1,2-ethane. The method described in. 10. A process according to claim 1, wherein the catalyst contains substantially titanium, halogen and magnesium atoms and optionally refractory oxides. 11. A catalyst comprising: (1) reacting a magnesium metal, a halogenated hydrocarbon and at least one tetravalent titanium compound, or (2) a granular support (a) dialkylmagnesium and, if necessary, triamine. An organoaluminum compound suitable for contacting with an alkylaluminum, (b) a halogenated hydrocarbon, and (c) a tetravalent titanium compound, or (3) a magnesium chloride support to reduce (a) a titanium compound, and (b) ) A method according to any one of claims 1 to 10, which is prepared by a method comprising contacting with a tetravalent titanium compound. 12. A halogenated hydrocarbon compound as a catalyst activator in (co) polymerization of one or more olefins in the presence of a Ziegler-Natta type titanium-based catalyst and an organometallic cocatalyst. When used, the halogenated hydrocarbon compound has a molar ratio of the amount of the halogenated hydrocarbon compound and the amount of titanium of more than 0.001 and 0.1.
Use of a halogenated hydrocarbon compound, characterized in that it is used in an amount such that it is less than 5. 13. Use according to claim 12, characterized in that the (co) polymerization is carried out continuously.