JPH0745531B2 - Method for producing polyethylene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a polyethylene having an ethyl branched chain by feeding only ethylene in the presence of a novel catalyst system.

[Conventional technology]

It is already known to use a catalyst system composed of a transition metal compound and an organometallic compound for low-pressure polymerization of ethylene, but recently, as a highly active catalyst, a reaction product of an inorganic or organomagnesium compound and a transition metal compound has been used. The catalyst system contained as a component is often used.

For example, JP-B-52-15110 and JP-A-56-155205 disclose a polymerization method capable of producing a polyolefin having extremely high impact resistance, in which a magnesium metal and a hydroxylated organic compound or magnesium are used. An extremely highly active catalyst system is used, which comprises a halide, a transition metal oxygen-containing organic compound, and a catalyst component obtained by reacting an aluminum halide with a catalyst component of an organometallic compound.

In addition, polyethylene can be used in combination with ethylene and other α- for applications requiring higher impact resistance and environmental stress resistance.
It is known that those having a branched chain such as a copolymer with an olefin are suitable. However, the method of copolymerizing ethylene with other α-olefin is also known to have a disadvantage in that the polymerization apparatus becomes complicated and the production cost increases because the α-olefin is relatively expensive. . Therefore, Japanese Patent Publication Nos. 36-441 and 44-20988 propose methods for producing branched-chain polyethylene by supplying only ethylene.

However, as a result of investigations by the present inventors, a conventional method for producing a polyethylene having a branched chain by supplying only ethylene was that in addition to useful butene-1, hexene-
It was found that low-reactivity olefins such as 1- and 2-ethylbutene-1,3-methylpentene-1 are also produced as by-products, which increases the production cost.

Further, when a relatively low density polyethylene is produced by a slurry method in which polymerization is carried out in the presence of a solvent, polyethylene particles swell in the solvent, the bulk density is lowered, or the solvent becomes viscous and becomes a polymer wall. This causes problems such as polymer adhesion and mutual adhesion of polymer particles. That is, said Japanese Patent Publication No. 44-20988
The polyethylene having a relatively low density obtained in the presence of the catalyst component disclosed in JP-A No. 1994-2000 has a problem that productivity is low because the bulk density is low and the slurry concentration cannot be increased.

[Problems to be solved by the invention]

Therefore, the present inventors did not impair the characteristic of being able to produce a polymer with high activity in JP-B-52-15110, and did not use a relatively expensive α-olefin other than ethylene, and the impact resistance As a result of intensive studies aimed at producing polyethylene with excellent properties such as resistance to environmental stress and resistance to environmental stress, polymerization was carried out by supplying only ethylene in the presence of a catalyst consisting of a specific combination. By carrying out, it was found that polyethylene having a branched chain can be produced with extremely high productivity, and the present invention was completed.

[Means for solving problems]

That is, the present invention provides a method for producing polyethylene in which ethylene is polymerized in the presence of a Ziegler type catalyst having high activity and hydrogen, wherein the catalyst comprises (A) (i) metal magnesium and alcohol, and oxygen-containing organic magnesium. At least one member selected from compounds, (ii) at least one tetravalent titanium oxygen-containing organic compound, (iii) at least one organoaluminum compound and / or (iv) at least one polysiloxane or alkoxysilane And a solid catalyst component (A) obtained by reacting (v) at least one aluminum halide compound, and (B) at least one organoaluminum compound catalyst component (B). ) and, (C) the general formula Ti _{(oR) 4} (R: alkyl group having 2 to 10 carbon atoms or a, Group) and at least one catalyst component (C) selected from titanium compounds represented by the formula (1), and (D) at least one catalyst component (D) selected from halogenated hydrocarbon compounds. Is a method for producing polyethylene.

[Action]

The catalyst used in the present invention is highly active, and has the characteristics that polymer particles are less likely to swell or adhere to the walls of the polymerization vessel due to the decrease in the density of the polymer, and the production of by-products is suppressed. Although the reason why the catalyst of the present invention has excellent properties is not clear, the solid catalyst component (A) having a good particle shape can be obtained by the reaction of the components of the reactants (i) to (v), and the solid catalyst component A high activation is achieved by the interaction of (A), the catalyst component (B) and the catalyst component (D), and
Catalyst component (B), catalyst component (C) and catalyst component (D)
Since it is possible to produce butene-1 in a high yield while suppressing the production of by-products due to the interaction of the above, it is considered that polyethylene having a branched chain can be produced with extremely high productivity by supplying only ethylene. .

In the present invention, the following are examples of the group consisting of the above-mentioned metal magnesium (i) which is a reactant used for preparing the solid catalyst component (A) and alcohol.

Various forms of metallic magnesium, namely powder,
Any shape such as particles, foils or ribbons can be used.

As alcohols, straight-chain or branched-chain aliphatic alcohols, alicyclic alcohols or aromatic alcohols having 1 to 18 carbon atoms can be used. Examples include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, n-amyl alcohol, i-amyl alcohol, n-hexanol, 2-methylpentanol, 2-ethylhexanol, n. -Octanol, i
Examples include -octanol, 1-decanol, 1-dodecanol, n-stearyl alcohol, cyclopentanol, cyclohexanol, and ethylene glycol.

Of course it is good to use alcohol alone,
Especially preferred is the use of mixtures of straight-chain aliphatic alcohols having 2 to 18 carbon atoms and branched chain aliphatic alcohols having 3 to 18 carbon atoms. In that case, the molar ratio of the linear aliphatic alcohol and the branched aliphatic alcohol is preferably in the range of 10: 1 to 1:10, particularly preferably 3: 1.
The range is from ~ 1: 3.

In addition, when using magnesium metal to obtain the solid catalyst component (A) described in the present invention, for the purpose of accelerating the reaction, a substance that reacts with magnesium metal or forms an addition compound, for example, Iodine, mercuric chloride,
It is preferable to add a polar substance such as an alkyl halide, an organic acid ester and an organic acid alone or in combination of two or more.

Next, as compounds belonging to the oxygen-containing organic compound of magnesium, magnesium alkoxides such as methylate, ethylate, isopropylate, decanolate, methoxyethylate and cyclohexanolate,
Magnesium alkyl alkoxides such as ethyl ethylate, magnesium hydroalkoxides such as hydroxymethylate, magnesium phenoxides,
For example, phenates, naphthenates, phenanthrenates and cresolates, magnesium carboxylates, such as acetates, stearates, benzoates,
Phenylacetate, adipate, sebacate, phthalate, acrylates and oleates, oximates such as butyloxymate, dimethylglyoxymate and cyclohexyloxymate, hydroxamates, hydroxylamine salts such as N-Etroso-N-phenyl-hydroxylamine derivatives , Enolates such as acetylacetonate, magnesium silanolates such as triphenylsilanolate, complex alkoxides of magnesium with other metals such as Mg [Al
(OC ₂ H ₅ ) ₄ ] ₂ . These oxygen-containing organomagnesium compounds are used alone or as a mixture of two or more kinds.

As the oxygen-containing organic compound of tetravalent titanium that is the reaction agent of (ii), a compound represented by the general formula [TiO _a (OR ² ) _b ] _m is used. However, in the general formula, R ² represents a hydrocarbon group such as a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, a cycloalkyl group, an arylalkyl group, an aryl group and an alkylaryl group. , A and b represent numbers such that a ≧ 0 and b> 0 and are compatible with the valence of titanium, and m represents an integer. Above all, it is desirable to use an oxygen-containing organic compound in which a is 0 ≦ a ≦ 1 and m is 1 ≦ m ≦ 6.

Specific examples include titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetra-i-propoxide, titanium tetra-n-butoxide, and hexa-i-.
Examples include propoxy dititanate. The use of oxygen containing organic compounds having several different hydrocarbon groups is also within the scope of the invention. These oxygen-containing organic compounds of titanium are used alone or as a mixture of two or more kinds.

As the organoaluminum compound which is the above-mentioned (iii), a compound represented by the general formula ▲ R ¹ ₃ ▼ Al or ▲ R ¹ _n ▼ AlY _3-n is used. However, in the general formula,
R ¹ represents an alkyl group having the same or different 1 to 20, preferably 1 to 8 carbon atoms, Y represents 1 to 20,
Preferably an alkoxy group having 1 to 8 carbon atoms,
It represents an aryloxy group, a cycloalkoxy group or a halogen atom, and n represents a number of 1 ≦ n <3.

The organoaluminum compound can be used alone or as a mixture of two or more kinds.

Specific examples of the organic aluminum compound include triethyl aluminum, tri-i-butyl aluminum, diethyl aluminum chloride, ethyl aluminum sesquichloride, i-butyl aluminum dichloride, diethyl aluminum ethoxide and the like.

Polysiloxane or alkoxysilane is used as the above-mentioned reaction agent (iv).

The polysiloxane has the general formula (In the formula, R ³ and R ⁴ are hydrocarbon groups such as alkyl groups and aryl groups having 1 to 12 carbon atoms, hydrogen, halogen, and 1 to 12 carbon atoms.
Represents a silicon-bonding atom or residue such as 12 alkoxy groups, allyloxy groups, and fatty acid residues, R ³ and R ⁴
May be the same or different, and p usually represents an integer of 2 to 10,000), and 1 or 2 of the repeating units represented by
A siloxane polymer having a linear, cyclic, or three-dimensional structure having at least one species in various proportions and distributions in the molecule (except when all R ³ and R ⁴ are hydrogen or halogen) ) Is given.

Specifically, as the chain polysiloxane, for example, hexamethyldisiloxane, octamethyltrisiloxane,
Dimethylpolysiloxane, diethylpolysiloxane, methylethylpolysiloxane, methylhydropolysiloxane, ethylhydropolysiloxane, butylhydropolysiloxane, hexaphenyldisiloxane, octaphenyltrisiloxane, diphenylpolysiloxane, phenylhydropolysiloxane, methylphenylpolysiloxane Examples include siloxane, 1,5-dichlorohexamethyltrisiloxane, 1,7-dichlorooctamethyltetrasiloxane, dimethoxypolysiloxane, diethoxypolysiloxane, diphenoxypolysiloxane.

Examples of the cyclic polysiloxane include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, 2,4,6-trimethylcyclotrisiloxane, 2,4,6,8-tetramethylcyclotetrasiloxane, Triphenyltrimethylcyclotrisiloxane, tetraphenyltetramethylcyclotetrasiloxane, hexaphenylcyclotrisiloxane,
Examples include octaphenylcyclotetrasiloxane.

As the polysiloxane having a three-dimensional structure, for example, the above chain or cyclic polysiloxane having a crosslinked structure by heating or the like can be mentioned.

It is desirable that these polysiloxanes be liquid for handling, and that the viscosity at 25 ° C. is in the range of 1 to 10,000 centistokes, preferably 1 to 1,000 centistokes. However, it is not necessary to limit it to a liquid state, and a solid substance generally called a silicone grease may be used.

Specific examples of the alkoxysilane include trimethylmethoxysilane, dimethyldiethoxysilane, tetramethoxysilane, diphenyldiethoxysilane, tetramethyldiethoxydisilane, and dimethyltetraethoxydisilane.

The above organic polysiloxane or alkoxysilane may be used alone, or two or more kinds may be mixed or reacted and used.

As the aluminum halide compound which is the reaction agent of the above (v), those represented by the general formula ∑R ⁵ _z ∑AlX _3-z are used. However, in the general formula, R ⁵ represents a hydrocarbon group having 1 to 20, preferably 1 to 8 carbon atoms, X represents a halogen atom, and z represents a number of 0 ≦ z <3, It is preferably 0 ≦ z ≦ 2. R ⁵ is preferably selected from linear or branched alkyl groups, cycloalkyl groups, arylalkyl groups, aryl groups and alkylaryl groups.

The above aluminum halide compounds can be used alone or as a mixture of two or more kinds.

Specific examples of the aluminum halide compound include aluminum trichloride, diethyl aluminum chloride, ethyl aluminum dichloride, i-butyl aluminum dichloride, and a mixture of triethyl aluminum and aluminum trichloride.

Reactants (i), (ii), (iii) and / or (iv)
The reaction order of can be any order as long as it causes a chemical reaction. That is, for example, a method of adding polysiloxane or alkoxysilane to a mixture of a magnesium compound and a titanium compound, a method of adding an organoaluminum compound to a mixture of a magnesium compound and a titanium compound and then adding a polysiloxane or an alkoxysilane, a magnesium compound, a titanium compound and a poly A method of simultaneously mixing siloxane or alkoxysilane, a method of adding a titanium compound to a magnesium compound and polysiloxane or alkoxysilane, and the like can be considered. Among them, the method of adding an organoaluminum compound to a mixture of a magnesium compound and a titanium compound, and then adding a polysiloxane or an alkoxysilane is preferable because of excellent powder characteristics. The product thus obtained is reacted with aluminum halide to obtain a solid catalyst component (A).

These reactions are preferably carried out in a liquid medium. Therefore, it should be carried out in the presence of an inert organic solvent, especially if these reactants themselves are not liquid under the operating conditions or if the amount of liquid reactant is insufficient. As the inert organic solvent, all those commonly used in the art can be used, and examples thereof include aliphatic, alicyclic or aromatic hydrocarbons, halogen derivatives thereof, or a mixture thereof, such as isobutane and hexane. , Heptane, cyclohexane, benzene, toluene, xylene,
Monochlorobenzene and the like are preferably used.

The amount of the reaction agent used in the present invention is not particularly limited,
The atomic ratio of the gram atom of Mg in the magnesium compound of (i) to the gram atom of Ti in the titanium compound of (ii) is 1/20 ≦ Mg / Ti ≦ 200, preferably 1/2 ≦ Mg / Ti ≦ 50. If the Mg / Ti is out of this range and the Mg / Ti is too large, it becomes difficult to obtain a uniform Mg-Ti solution at the time of catalyst preparation, or the activity of the catalyst becomes low at the time of polymerization. On the other hand, if it is too small, the activity of the catalyst becomes low, which causes problems such as coloring of the product.

When the organoaluminum compound ▲ R ¹ ₃ ▼ Al or ▲ R ¹ _n ▼ AlY _3-n (wherein n is 1 ≦ n <3) of the above (iii) is used, Gram atom of Al (hereinafter, Al
The atomic ratio of gram atoms of Ti in the titanium compound of (ii) above to the product of (iii) multiplied by n (▲ R ¹ ₃ ▼ Al is gram atoms of Al × 3). Preferably, It is preferable to select the amount used so as to be in the range. Outside this range If it is too large, the catalytic activity will be low, and if it is too small, improvement of the powder properties will not be desired.

The atomic ratio of the gram atom of Si in the polysiloxane or alkoxysilane of (iv) to the gram atom of Mg in the magnesium compound of (i) is 1/20 ≦ Mg / Si ≦ 100, preferably 1/5. It is preferable to select the amount used so that ≦ Mg / Si ≦ 10. If the content of Mg / Si is out of this range and the content is too large, the improvement of the powder properties will be insufficient. Conversely, if it is too small, the activity of the catalyst is low.

When the organoaluminum compound (iii) is used, the amount of the aluminum halide compound (v) used is such that the gram atom (Al (iii)) of Al in the organoaluminum compound (iii) and the aluminum halide compound ( The atomic ratio of gram atoms of Al in v) (hereinafter referred to as Al (v)) is 1/20 ≦ Al (iii) / Al (v) ≦ 10 and 1/2 ≦ p.
(However, Where Ti and X represent gram atoms of titanium and halogen, respectively, Mg represents gram atom of Mg in metallic magnesium or magnesium compound, and s represents gram equivalent of alkoxy group in polysiloxane or alkoxysilane. Represents), preferably And it is preferable to select it so as to be in the range of 4/5 ≦ p.

If the atomic ratio of is out of this range, improvement in powder properties is not desired, and if p is too small, the activity of the catalyst becomes low.

When the organoaluminum compound (iii) is not used, the amount of the aluminum halide compound (v) used is
It is preferable to select it in the range of 1 ≦ al (v) / Mg ≦ 100.

The reaction conditions in each step are not particularly limited, but may be -50 to 300.
C., preferably in the range of 0 to 200.degree. C., for 0.5 to 50 hours, preferably 1 to 6 hours in an inert gas atmosphere at atmospheric pressure or under pressure.

The solid catalyst component (A) thus obtained may be used as it is, but generally, the unreacted substances and by-products which remain are removed by an excess or gradient method, and then washed with an inert organic solvent several times. , Suspended in an inert organic solvent for use.
It is also possible to use a product which is isolated after washing and heated under normal pressure or reduced pressure to remove the inert organic solvent.

In the present invention, the organoaluminum compound which is the catalyst component (B) is represented by the general formula Al ▲ R ⁶ _n ▼ ▲ R ⁷ _3-n ▼ (R ⁶ , R ⁷ :
Hydrogen or an alkyl group).
This alkyl group has a straight or branched chain carbon number of 1
~ 20 alkyl groups are used. Examples of such an organoaluminum compound include trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, diethylaluminummonohydride, dibutylaluminummonohydride and the like. Is mentioned.

The general formula Ti (OR ⁸ ) ₄ (R ⁸ : C2-C2 used in the present invention
Examples of the catalyst component (C) represented by 10 alkyl groups or aryl groups) include titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetra-
i-propoxide, titanium tetra-n-butoxide, titanium tetra-i-butoxide, titanium tetra-n-pentoxide, titanium tetra-i-pentoxide, titanium tetraphenoxide, titanium tetra-o-crezoxide,
Titanium tetra-m-cresoxide, titanium tetra-p-
Examples include crezoxide and the like.

In the present invention, the halogenated hydrocarbon compound which is the catalyst component (D) is generally a halogen derivative of a hydrocarbon having 1 to 12 carbon atoms, and usually a liquid one is preferable. Among them, a halogen-containing compound having 2 or less carbon atoms is particularly preferable because of its remarkable effect. Specific examples of such compounds include methylene chloride, chloroform, carbon tetrachloride, methylene bromide, methyl iodide, methylene iodide, monochloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1 , 1,2,2-Tetrachloroethane, 1,1,1,2-tetrachloroethane, pentachloroethane, hexachloroethane, vinylidene chloride,
Examples include trichlorethylene and tetrachlorethylene.

In the practice of the present invention, the catalyst component (A) is used in an amount of 0.1 titanium atom per solvent or 1 reactor.
It is preferably used in an amount corresponding to 001 to 2.5 mmol (mmol), and higher concentration can be used depending on the conditions.

The organoaluminum compound of component (B) is used in a concentration of 0.02 to 50 mmol, preferably 0.2 to 5 mmol, per solvent or reactor 1.

The amount of the catalyst component (C) used is closely related to the density of the polymer produced or the number of ethyl branches, and is adjusted according to the desired density.

The halogenated hydrocarbon of the catalyst component (D) is used at a concentration of 0.00001 to 500 mmol, preferably 0.0001 to 100 mmol, per solvent or reactor.

The ratio of the amount of each catalyst component used is Al for component (B) and component (C).
It is used in the range of the Ti / Ti molar ratio of 1 to 200. If it is out of this range, the production rate of butene-1 will decrease. The component (D) and the component (C) have a molar ratio of (D) / (C) in the range of 0.001 to 4, preferably 0.02 to 1, and if the ratio is less than this, there is no effect of suppressing the production of by-products, If it is more than this range, the reaction of butene-1 formation does not occur.

The mode of feeding the four components into the polymerization vessel in the present invention is not particularly limited, but for example, a method of feeding the four components separately into the polymerization vessel, the component (A) and the component (D) can be used. Method of mixing and feeding, method of mixing and feeding component (C) and component (D), contacting component (A) and component (D) and then contacting component (B), and further component A method of bringing (C) into contact can be adopted.

The ethylene polymerization of the present invention can be carried out in a liquid phase or a gas phase. When the polymerization is carried out in the liquid phase, it is preferable to use an inert solvent. The inert solvent can be any of those commonly used in the art, especially alkanes, cycloalkanes having 4 to 20 carbon atoms, such as isobutane, pentane,
Hexane, cyclohexane, etc. are suitable.

The reaction conditions for the polymerization can be the general reaction conditions of the so-called Ziegler method. That is, the temperature is in the range of 20 to 200 ° C. in the continuous or batch system, and particularly in the temperature range of 50 to 90 ° C. when the polymerization method is the slurry method. The polymerization pressure is not particularly limited, but pressurization, particularly in the range of 1.5 to 50 atm, is suitable.

In the present invention, the molecular weight of the polymer can be adjusted by a method such as allowing a suitable amount of hydrogen to exist in the polymerization system. Further, in order to control the molecular weight distribution, it is also possible to employ a so-called multi-stage polymerization method comprising a plurality of polymerization steps.

〔The invention's effect〕

The effects of the present invention are as follows. First, by supplying only ethylene in the presence of a specific catalyst to carry out polymerization, polyethylene having a branched chain exhibiting excellent properties is supplied as an expensive α-olefin other than ethylene. In other words, the production of by-products can be suppressed and the production can be efficiently performed. Therefore, when carrying out the polymerization according to the present invention, the step of supplying another α-olefin can be omitted, and when the polymerization is carried out under an inert solvent, the step of removing unnecessary olefins from the solvent after the polymerization can be simplified or energy saving can be achieved. And industrial productivity can be improved.

The second effect of the present invention is that the particle properties of the polymer are remarkably excellent. In particular, when a polymer having a relatively low density is obtained by a slurry method, particles can be obtained while maintaining good bulk density and particle properties. Further, since the polymer can be stably polymerized without swelling of the polymer or adhesion to the wall of the polymerization vessel, it is possible to contribute to the improvement of productivity.

The third effect of the present invention is that the catalyst activity is high and the amount of the polymer obtained per solid catalyst component (A) is extremely large. Therefore, problems such as deterioration and coloring at the time of molding the polymer can be avoided.

〔Example〕

Hereinafter, the present invention will be shown by examples, but the present invention is not limited to these examples. In addition,
In Examples and Comparative Examples, HLMI / MI is high load melt index (HLMI, according to ASTM D-1238 condition F) Melt index (MI, according to ASTM D-1238 condition E)
And the density was measured and determined from ASTM D-1505.

The activity represents the amount of polyethylene produced (g) per gram of the solid catalyst component (A). The number of ethyl branches in polyethylene was calculated from the peak at 1378 cm ^{-1 in} the infrared absorption spectrum.

The selectivity of butene-1 was determined by analyzing the liquid phase and the gas phase after polymerization by gas chromatography. ▲ C ⁼ ₄ ▼, ▲ C
⁼ ₆ ▼, ▲ C ⁼ ₈ ▼ and the amount of butene-1 produced (%) relative to the total amount of butene-1 copolymerized from the number of ethyl branches in polyethylene.

Example 1 (a) [Preparation of solid catalyst component (A)] 70 g (0.94 mol) of n-butanol was put into an autoclave of 1.6 equipped with a stirrer, and 0.55 g of iodine and 11 g of metal magnesium powder (0.45 mol). ) And 61 g (0.18 mol) of titanium tetrabutoxide, and then hexane 4
After adding 50 ml, the temperature was raised to 80 ° C. and the mixture was stirred under a nitrogen blanket for 1 hour while eliminating generated hydrogen gas. Continue to 12
The temperature was raised to 0 ° C and the reaction was carried out for 1 hour to obtain a Mg-Ti solution.

To a flask having an internal volume of 500 ml, 0.048 mol of Mg-Ti solution in terms of Mg was added, the temperature was raised to 45 ° C, and a hexane solution of tri-i-butylaluminum (0.048 mol) was added over 1 hour.
After adding all, the mixture was stirred at 60 ° C. for 1 hour. Next, 28 ml of methylhydropolysiloxane (viscosity of about 30 centistokes at 25 ° C.) (0.048 gram atom of silicon) was added, and the mixture was reacted under reflux for 1 hour. After cooling to 45 ° C., 90 ml of a 50% hexane solution of i-butylaluminum dichloride was added over 2 hours. After adding all, stirring was carried out at 70 ° C. for 1 hour. Hexane was added to the product, and the product was washed 15 times by the gradient method. Thus, a slurry (containing 9.5 g of the solid catalyst component (A)) of the solid catalyst component (A) suspended in hexane was obtained. A part of the sample was collected, the supernatant was removed, the sample was dried under a nitrogen atmosphere, and elemental analysis revealed that Ti was 8.9 wt%.

(B) [Polymerization] The inside of the electromagnetic stirring reactor made of stainless steel with an internal volume of 2 was sufficiently replaced with nitrogen, and hexane 1.2 was charged and the internal temperature was adjusted to 6
Adjusted to 5 ° C. Then, as a catalyst component (B), tri-
0.23 g (1.2 mmol) of i-butylaluminum, component (C)
As the component (D), 80 mg (0.24 mmol) of titanium tetrabutoxide, 6 mg (0.06 mmol) of 1,2-dichloroethane, and 10 mg of the component (A) were sequentially added. After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen gas, hydrogen 2.7 kg / cm ²
Polymerization was carried out for 1.5 hours while ethylene was added so that the total pressure became 8.7 kg / cm ² G. The polyethylene was taken out from the reactor, taken out from the solvent by filtration, and dried. As a result, MI was 1.2 g / 10 minutes, HLMI / MI was 31, and density was 0.92.
172 g of polyethylene having 6 g / cm ³ and a bulk density of 0.34 g / cm ³ was obtained. The catalytic activity was 17,200 g / g, and the number of ethyl branches in polyethylene was 14.1 / 1000 carbon atoms. The selectivity of butene-1 was 93.2%.

Examples 2 and 3, Comparative Examples 1 and 2 In the method of Example 1, only the amounts of the component (C) titanium tetrabutoxide and the component (D) 1,2-dichloroethane used were as shown in Table 1. Experiments were conducted by changing each. That is, the solid catalyst component (A) and tri-i-butylaluminum prepared in Example 1 were used in the same manner as in Example 1, and the amounts of the component (C) used in Examples 2 and 3 were changed. Comparative Example 2 without using the component (C)
Then, polymerization was carried out without using the component (D). However, in Comparative Example 1 only, hydrogen was added at 5.0 kg / cm ² so that the total pressure was 11.0 kg / cm ² G in order to make MI equal to that of others.
As is clear from the results in Table 1, the component (C) produces polyethylene having a branched chain, and the component (D) improves the butene-1 selectivity and suppresses the production of by-products. I understand.

Comparative Example 3 (a) [Preparation of solid catalyst component] A glass flask having an internal volume of 500 ml was charged with 60 g of magnesium hydroxychloride, 12 g of titanium tetrachloride and 200 ml of xylene and reacted at 130 ° C. for 2 hours. Then, hexane was added to the product, and the product was washed by a gradient method. Elemental analysis of the obtained solid catalyst component revealed that Ti was 0.62 wt%.

(B) [Polymerization] In the same manner as in Example 1, a polymerization experiment was conducted using 400 mg of the above solid catalyst component. As a result, 113 g of polyethylene having an MI of 0.52 g / 10 minutes and a density of 0.925 g / cm ³ was obtained, but the bulk density was 0.21 g / cm ³ , which was significantly lower than that of the examples. The activity of the catalyst was 280 g / g, the number of ethyl branches in polyethylene was 13.9 / 1000 carbon atoms, and the butene-1 selectivity was 91.4%.

Comparative Example 4 (a) [Preparation of solid catalyst component] 100 stainless steel balls having a diameter of 11 mm, the internal volume 8
20 g of magnesium chloride and 0.73 ml of titanium tetrachloride were charged into a 00cc ball mill pot under a nitrogen atmosphere and mechanically pulverized for 80 hours. The Ti content in the solid catalyst component was 1.52 wt%.

(B) [Polymerization] In the same manner as in Example 1, a polymerization experiment was conducted using 10 mg of the above solid catalyst component, 74 mg (0.22 mmol) of titanium tetrabutoxide and 5.5 mg (0.055 mmol) of 1,2-dichloroethane.

As a result, 191 g of polyethylene having an MI of 0.91 g / 10 minutes and a density of 0.925 g / cm ³ was obtained, but the bulk density was 0.25, which was much lower than in the examples. The activity of the catalyst was 19200 g / g, the number of ethyl branches in polyethylene was 13.7 / 1000 carbon atoms, and the butene-1 selectivity was 92.1%.

Example 4 (a) [Preparation of solid catalyst component (A)] Into an autoclave of 1.6 equipped with a stirrer, 32.2 g (0.42 mol) of n-butanol was placed, and 0.45 g of iodine,
4.9g (0.20mol) of magnesium metal powder and 27g (0.08mol) of titanium tetrabutoxide were added, and then 200ml of hexane was added and the temperature was raised to 80 ° C. Stirred under a nitrogen seal for 1 hour while eliminating hydrogen gas generated. did. Subsequently, the temperature was raised to 120 ° C. and the reaction was carried out for 1 hour. Then 120 ° C
Then, 14.8 g (0.2 gram atom of silicon) of dimethylpolysiloxane (viscosity of about 50 centistokes at 25 ° C.) was pressure-fed by nitrogen and reacted at 120 ° C. for 1 hour. After the reaction, 300 ml of hexane was added and after cooling to 45 ° C., 450 ml of a 50% hexane solution of i-butylaluminum dichloride was added over 2 hours. After adding all, stirring was carried out at 70 ° C. for 1 hour. Hexane was added to the product, and the product was washed 15 times by the gradient method. Thus, the solid catalyst component (A) suspended in hexane
A slurry of was obtained. A part of the sample was collected, the supernatant was removed, the sample was dried under a nitrogen atmosphere, and elemental analysis revealed that Ti was 9.
It was 3 wt%.

(B) [Polymerization] In the same manner as in Example 1, 12 mg of the above solid catalyst component (A)
Polymerization experiment was carried out using. As a result, MI is 1.4g / 10
Min, HLMI / MI 31, density 0.925g / cm ³ , bulk density 0.34g / cm ³
191 g of polyethylene was obtained, and the catalytic activity was 15900 g / g. The number of ethyl branches in polyethylene was 15.1 / 1000 carbon atoms, and the butene-1 selectivity was 91.9%.

Examples 5 to 7 The solid catalyst component (A) was prepared and ethylene was polymerized in the same manner as in Example 4. However, the reactive agent (iv) used
Various compounds were used in place of dimethylpolysiloxane as the silicon compound. That is, 27 g (0.2 g atom of silicon) of methylphenyl polysiloxane (viscosity of about 500 centistokes at 25 ° C.) in Example 5, 21 g (0.1 mol) of ethyl orthosilicate in Example 6, and 12 g of methyl orthosilicate in Example 7 ( 0.08 mol) was used to prepare the solid catalyst component (A). Example 1 using each catalyst
Table 2 shows the results of polymerization of ethylene carried out in the same manner as in.

Examples 8 to 10 and Comparative Example 5 An experiment was conducted by changing the compounds used as the component (C) and the component (D) in the method of Example 1 as shown in Table 2. That is, the solid catalyst component (A) prepared in Example 1 and tri-i-butylaluminum were used in Example 1
As in Example 8, 1 mg (0.01 mmol) of dichloromethane was used as the component (D) in Example 8, and 4 mg (0.03 mmol) of 1,1,1-trichloroethane was used as the component (D) in Example 9.
Then, as the component (C), titanium tetra-i-propoxide is used.
Polymerization was performed by changing 70 mg (0.25 mmol).
Further, in Comparative Example 5, titanium tetra- was used as the component (C).
Polymerization was carried out using i-propoxide and without using component (D). The results are shown in Table 3.

Example 11 Polyethylene was produced by the two-step polymerization method using the solid catalyst component (A) prepared in Example 1. That is, the internal volume
10 stainless steel, the inside of the magnetic stirring type reactor was sufficiently replaced with nitrogen, hexane 6.0 was charged, and the internal temperature was 65 ° C.
Adjusted to. Then, as a catalyst component (B), tri-i-
1.19 g (6.0 mmol) of butylaluminum, 300 mg (0.88 mmol) of titanium tetrabutoxide as component (C), 20 mg (0.2 mmol) of 1,2-dichloroethane as component (D) and 55 mg of solid catalyst component (A) of Example 1 Were sequentially added.
After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen, hydrogen
Polymerization was performed for 50 minutes while adding 9.0 kg / cm ² and continuously adding ethylene so that the total pressure was 15.0 kg / cm ² G, to produce a low molecular weight polymer.

Next, the gas phase of this reactor was replaced with nitrogen, and 150 mg (0.44 mmol) of titanium tetrabutoxide of component (C) was added,
The internal temperature was 65 ° C, the internal pressure was 1.0 kg / cm ² G, hydrogen was added at 1.0 kg / cm ^2, and the polymerization was carried out for 45 minutes while continuously adding ethylene so that the total pressure was 7.0 kg / cm ² G. , A high molecular weight polymer was produced. The amount of polymer obtained was 1080 g, and as a result of grasping the amount of production in each stage by the flow rate of ethylene, 50 wt% for the low molecular weight polymer and 50 wt% for the high molecular weight polymer.
%Met.

The resulting polymer, MI is 0.42 g / 10 min, HLMI / MI of 44, a density of 0.922 g / cm ^3, a bulk density of 0.30 g / cm ^3, 18.0 cells / 1000 carbon atoms have a ethyl branches Was. Butene-
The selectivity of 1 was 91.3%.

Example 12 Using the solid catalyst component (A) prepared in Example 1, polyethylene was produced by a two-step polymerization method. That is, stainless steel with an internal volume of 10, the inside of the magnetic stirring type reactor was sufficiently replaced with nitrogen and hexane 6.0 was charged, and the internal temperature was 75 ° C.
Adjusted to. Then, as a catalyst component (B), tri-i-
1.19 g (6.0 mmol) of butyl aluminum, 200 mg (0.59 mmol) of titanium tetrabutoxide as component (C), 15 mg (0.15 mmol) of 1,2-dichloroethane as component (D) and 75 mg of solid catalyst component (A) of Example 1 Were sequentially added. After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen,
Polymerization was carried out for 60 minutes while adding 3.0 kg / cm ² of hydrogen and continuously adding ethylene so that the total pressure was 15.0 kg / cm ² G to produce a low molecular weight polymer.

Next, the gas phase of this reactor was replaced with nitrogen, and the internal temperature was 75 ° C.
Adjust the internal pressure to 1.0 kg / cm ² G and add hydrogen 1.5 kg / cm ² to obtain the total pressure.
Polymerization was carried out for 40 minutes while ethylene was continuously added so as to obtain 7.5 kg / cm ² G to produce a high molecular weight polymer. The amount of the polymer obtained was 1420 g, and the production amount in each stage was 50 wt% for the low molecular weight polymer and 50 wt% for the high molecular weight polymer.

The resulting polymer, MI is 0.15 g / 10 min, HLMI / MI of 105, a density of 0.939 g / cm ^3, a bulk density of 0.38 g / cm ^3, 9.8 pieces / 100
It had an ethyl branch of 0 carbon atoms. Butene-
The selectivity of 1 was 90.9%.

Example 13 Using the solid catalyst component (A) prepared in Example 1, polyethylene was produced by a gas phase polymerization method. That is, a glass electromagnetic stirring reactor with an internal volume of 1 has a diameter of 0.710 mm (24 m
100 g of glass beads (corresponding to esh) were charged and dried under reduced pressure at 90 ° C. for 2 hours, and then the inside of the reactor was sufficiently replaced with nitrogen.
Then, 0.46 g (2.4 mmol) of tri-i-butylaluminum as the catalyst component (B), 180 mg (0.52 mmol) of titanium tetrabutoxide as the component (C), and 1,2 as the component (D).
14 mg (0.14 mmol) of dichloroethane and 21 mg of the solid catalyst component (A) prepared in Example 1 were sequentially added. After reducing the pressure in the reactor, adjust to ² kg / cm ² G with hydrogen gas, perform polymerization for 1.5 hours while adding ethylene so that the total pressure becomes 6 kg / cm ² G, and press fit 3 ml of ethanol. The reaction was stopped. Hexane was introduced into the system to grasp the amount of by-products produced, and then polyethylene containing glass beads and hexane containing by-products were taken out of the reactor.

As a result, MI is 1.2 g / 10 minutes, HLMI / MI is 31, density 0.934 g / c
56 g of polyethylene having m ³ and a bulk density of 0.29 g / cm ³ was obtained.
The number of ethyl branches in polyethylene was 8/1000 carbon atoms, and the butene-1 selectivity was 91.4%.

Example 14 (a) [Preparation of solid catalyst component (A)] To a 1.6 l autoclave equipped with a stirrer, 21.3 g (0.2 mol) of diethoxymagnesium and 68 g (0.2 mol) of titanium tetrabutoxide were added, and the mixture was heated at 120 ° C. The temperature was raised to and stirred for 1 hour. Then add 450 ml of hexane and add Mg-Ti.
A solution was obtained.

0.06 mol of Mg-Ti solution in terms of Mg was added to a flask having an internal volume of 500 ml, the temperature was raised to 45 ° C., and diethylaluminum chloride (0.12 mol) was added over 1 hour. After adding all, the mixture was stirred at 60 ° C. for 1 hour. Next, 3.4 ml of methylhydropolysiloxane (viscosity of about 30 centistokes at 25 ℃)
(0.12 gram atom of silicon) was added, and the mixture was reacted under reflux for 1 hour. After cooling to 45 ° C, 118 ml (0.32 mol) of a 50% hexane solution of i-butylaluminum dichloride was added over 2 hours. After adding everything, it stirred at 70 degreeC for 1 hour. Hexane was added to the product, and the product was washed 15 times by the gradient method. Thus, a slurry of the solid catalyst component (A) suspended in hexane (containing 11.8 g of the solid catalyst component (A))
Got

A part of the sample was collected, the supernatant was removed, the sample was dried under a nitrogen atmosphere, and elemental analysis revealed that Ti was 12.1 wt%.

(B) Polymerization The inside of a stainless steel magnetic stirring type reactor having an internal volume of 2 l was sufficiently replaced with nitrogen, 1.2 l of hexane was charged, and the internal temperature was adjusted to 65 ° C. Then, 0.23 g (1.2 mmol) of tri-i-butylaluminum as a catalyst component (B), 80 mg (0.24 mmol) of titanium tetrabutoxide as a component (C), and a component (D).
As the solvent, 1,2-dichloroethane (6 mg, 0.06 mmol) and the above component (A) (10 mg) were sequentially added. After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen gas, add 2.7 kg / cm ² of hydrogen and 1.5 while adding ethylene so that the total pressure becomes 8.7 k / cm ² G.
Polymerization was carried out for a time. The polyethylene was taken out from the reactor, separated from the solvent by filtration and dried. As a result, MI is 1.4 g / 10 minutes, HLMI / MI is 30, density is 0.928 g / cm ³ ,
158 g of polyethylene having a bulk density of 0.33 g / cm ³ was obtained. The catalytic activity was 15800 g / g, and the number of ethyl branches in polyethylene was 13.7 / 1000 carbon atoms. Also, butene-1
The selection rate was 92.4%.

Example 15 (a) [Preparation of solid catalyst component (A)] To a 1.6 l autoclave equipped with a stirrer, 21.3 g (0.2 mol) of diethoxymagnesium and 68 g (0.2 mol) of titanium tetrabutoxide were added, and the mixture was heated at 120 ° C. The temperature was raised to and stirred for 1 hour. Next, 150 g of dimethylpolysiloxane (viscosity of about 50 centistokes at 25 ° C.) (0.2 gram atom of silicon) was added and the reaction was carried out at 120 ° C. for 1 hour. Then 4
50 ml of hexane was added to obtain a Mg-Ti solution.

Add 0.06 mol of Mg-Ti solution in terms of Mg to a flask with an internal volume of 500 ml, raise the temperature to 45 ° C, add i-butylaluminum dichloride (0.36 mol) over 1 hour, and continue to 60 ° C.
The mixture was stirred for 1 hour. Hexane was added to the product, and the product was washed 15 times by the gradient method. Thus, a slurry of the solid catalyst component (A) suspended in hexane [solid catalyst component (A) 1
(Including 2.4g).

A part of the sample was collected, the supernatant was removed, the sample was dried under a nitrogen atmosphere, and elemental analysis revealed that Ti was 11.9 wt%.

(B) Polymerization The inside of a stainless steel magnetic stirring type reactor having an internal volume of 2 l was sufficiently replaced with nitrogen, 1.2 l of hexane was charged, and the internal temperature was adjusted to 65 ° C. Then, 0.23 g (1.2 mmol) of tri-i-butylaluminum as a catalyst component (B), 80 mg (0.24 mmol) of titanium tetrabutoxide as a component (C), and a component (D).
As the solvent, 1,2-dichloroethane (6 mg, 0.06 mmol) and the above component (A) (10 mg) were sequentially added. After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen gas, add 2.7 kg / cm ² of hydrogen and 1.5 while adding ethylene so that the total pressure becomes 8.7 k / cm ² G.
Polymerization was carried out for a time. The polyethylene was taken out from the reactor, separated from the solvent by filtration and dried. As a result, MI is 1.5 g / 10 minutes, HLMI / MI is 30, density is 0.930 g / cm ³ ,
160 g of polyethylene having a bulk density of 0.35 g / cm ³ was obtained. The catalytic activity was 16000 g / g, and the number of ethyl branches in polyethylene was 13.1 / 1000 carbon atoms. Also, butene-1
The selectivity was 92.9%.

Example 16 (a) [Preparation of solid catalyst component (A)] Into a 1.6 l autoclave equipped with a stirrer was charged 70 g (0.94 mol) of n-butanol, and 0.55 g of iodine and 11 g of metal magnesium powder (0.45 Mol) and hexa-i-
42 g (0.09 mol) of propoxydititanate was added, 450 ml of hexane was further added, the temperature was raised to 80 ° C., and the mixture was stirred for 1 hour under a nitrogen blanket while eliminating generated hydrogen gas. After that, the temperature is raised to 120 ℃ and the reaction is performed for 1 hour.
i solution was obtained.

0.06 mol of Mg-Ti solution in terms of Mg was added to a flask having an internal volume of 500 ml, the temperature was raised to 45 ° C., and tri-i-butylaluminum (0.05 mol) was added over 1 hour. After adding everything
The mixture was stirred at 60 ° C for 1 hour. Next, 2.8 ml of methylhydropolysiloxane (viscosity of about 30 centistokes at 25 ℃)
(0.05 gram atom of silicon) was added, and the mixture was reacted under reflux for 1 hour. After cooling to 45 ° C., 90 ml (0.24 mol) of a 50% hexane solution of i-butylaluminum dichloride was added over 2 hours. After adding everything, it stirred at 70 degreeC for 1 hour. Hexane was added to the product, and the product was washed 15 times by the gradient method. Thus, a slurry (containing 9.3 g of the solid catalyst component (A)) of the solid catalyst component (A) suspended in hexane was obtained.

A part of the sample was collected, the supernatant was removed, the sample was dried under a nitrogen atmosphere, and elemental analysis revealed that Ti was 8.1 wt%.

(B) Polymerization The interior of the stainless steel magnetic stirring type reactor having an internal volume of 2 l was sufficiently replaced with nitrogen, hexane 1.21 was charged, and the internal temperature was adjusted to 65 ° C. Then, 0.23 g (1.2 mmol) of tri-i-butylaluminum as a catalyst component (B), 80 mg (0.24 mmol) of titanium tetrabutoxide as a component (C), and a component (D).
As the solvent, 1,2-dichloroethane (6 mg, 0.06 mmol) and the above component (A) (10 mg) were sequentially added. After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen gas, add 2.7 kg / cm ² of hydrogen and 1.5 while adding ethylene so that the total pressure becomes 8.7 k / cm ² G.
Polymerization was carried out for a time. The polyethylene was taken out from the reactor, separated from the solvent by filtration and dried. As a result, MI is 1.4 g / 10 minutes, HLMI / MI is 30, density is 0.925 g / cm ³ ,
148 g of polyethylene having a bulk density of 0.32 g / cm ³ was obtained. The catalytic activity was 14800 g / g, and the number of ethyl branches in polyethylene was 14.3 / 1000 carbon atoms. Also, butene-1
The selectivity was 93.0%.

Example 17 (ii) [Preparation of solid catalyst component (A)] In a 1.6 l autoclave equipped with a stirrer, 86.6 g (1.17 mol) of n-butanol was placed, and 0.5 g of iodine and 11 g of metallic magnesium powder ( 0.45 mol) and 70 g (0.23 mol) of titanium tributoxycyclolide were further added, and 450 ml of hexane was further added, the temperature was raised to 80 ° C., and the mixture was stirred for 1 hour under a nitrogen blanket while eliminating generated hydrogen gas. Subsequently, the temperature was raised to 120 ° C and the reaction was carried out for 1 hour to obtain a Mg-Ti solution.

0.05 mol of Mg-Ti solution was added to a flask having an internal volume of 500 ml, the temperature was raised to 45 ° C, and tri-i-butylaluminum (0.05 mol) was added over 1 hour. After adding everything
The mixture was stirred at 60 ° C for 1 hour. Next, 2.8 ml of methylhydropolysiloxane (viscosity of about 30 centistokes at 25 ℃)
(0.05 gram atom of silicon) was added, and the mixture was reacted under reflux for 1 hour. After cooling to 45 ° C, 80 ml (0.22 mol) of a 50% hexane solution of i-butylaluminum dichloride was added over 2 hours. After adding everything, it stirred at 70 degreeC for 1 hour. Hexane was added to the product, and the product was washed 15 times by the gradient method. Thus, a slurry (containing 9.6 g of the solid catalyst component (A)) of the solid catalyst component (A) suspended in hexane was obtained.

A part of the sample was collected, the supernatant was removed, the sample was dried under a nitrogen atmosphere, and elemental analysis revealed that Ti was 9.6 wt%.

(B) Polymerization The inside of a stainless steel magnetic stirring type reactor having an internal volume of 2 l was sufficiently replaced with nitrogen, 1.2 l of hexane was charged, and the internal temperature was adjusted to 65 ° C. Then, 0.23 g (1.2 mmol) of tri-i-butylaluminum as a catalyst component (B), 80 mg (0.24 mmol) of titanium tetrabutoxide as a component (C), and a component (D).
As the solvent, 1,2-dichloroethane (6 mg, 0.06 mmol) and the above component (A) (10 mg) were sequentially added. After adjusting the inside of the reactor to 1 kg / cm ² G with nitrogen gas, add 2.7 kg / cm ² of hydrogen and ethylene while adding total pressure to 8.7 kg / cm ² G 1.
Polymerization was performed for 5 hours. The polyethylene was taken out of the reactor, separated from the tooth by filtration, and dried. As a result, MI was 1.0 g / 10 minutes, HLMI / MI was 32, and density was 0.929 g / c.
157 g of polyethylene having m ³ and a bulk density of 0.33 g / cm ³ was obtained. The catalytic activity was 15700 g / g, and the number of ethyl branches in polyethylene was 13.3 / 1000 carbon atoms. The selectivity of butene-1 was 91.9%.

[Brief description of drawings]

FIG. 1 is a flow chart showing the catalyst preparation process.

Claims (4)

[Claims] 1. A method for producing polyethylene in which ethylene is polymerized in the presence of a Ziegler type catalyst having high activity and hydrogen, wherein the catalyst comprises (A) (i) metallic magnesium and alcohol, and oxygen-containing organic magnesium. At least one member selected from compounds, (ii) at least one tetravalent titanium oxygen-containing organic compound, (iii) at least one organoaluminum compound, and / or (iv) at least one polysiloxane or alkoxysilane And a solid catalyst component (A) obtained by reacting (v) at least one aluminum halide compound, and (B) at least one organoaluminum compound catalyst component (B). ) and, (C) 1 or the general formula Ti _{(oR) 4} (R: alkyl group having 2 to 10 carbon atoms or ants, And (D) at least one catalyst component (C) selected from titanium compounds represented by the formula (I), and (D) at least one catalyst component (D) selected from halogenated hydrocarbon compounds. Method for producing polyethylene. 2. A homogeneous solution in which the solid catalyst component (A) contains (i) metallic magnesium and at least one alcohol, and (ii) at least one tetravalent titanium oxygen-containing organic compound, iii) obtained by reacting at least one organoaluminum compound, then (iv) reacting at least one polysiloxane or alkoxysilane, and (v) further reacting at least one aluminum halide compound. The method according to claim 1), which is a solid reaction product. 3. The use ratio of the catalyst components (B) and (C) is
Claim 1 wherein the Al / Ti molar ratio is in the range of 1 to 200, and the molar ratio of (D) and (C) is 0.001 to 4 in the molar ratio of (D) / (C). ) The manufacturing method according to the item. 4. The method according to claim 1, wherein the catalyst component (D) has 2 or less carbon atoms.