JPH0665684B2 - Olefin polymerization catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has a high performance in that it exerts a high activity when subjected to the polymerization of olefins, and that a stereoregular polymer can be obtained in an extremely high yield. The catalyst component and the catalyst, more specifically, a solid composition obtained by contacting a fatty acid magnesium, a basic magnesium carbonate, a mono- or diester of an aromatic dicarboxylic acid, a halogenated hydrocarbon, and a titanium halide with an organoaluminum. The present invention relates to an olefin polymerization catalyst comprising an olefin polymerization catalyst component obtained by contacting with a compound, a silicon compound and an organoaluminum compound.

[Conventional technology]

Conventionally, as a catalyst for olefin polymerization having high activity, a combination of a solid titanium halide as a catalyst component and an organoaluminum compound is well known and widely used. Since the polymer yield per titanium (hereinafter referred to as the catalyst component and the polymerization activity per titanium in the catalyst component) was low, the so-called deashing step for removing the catalyst residue was unavoidable. Since this deashing process uses a large amount of alcohol or a chelating agent, a recovery device or a regenerating device for them is indispensable, and there are many resources, energy, and other incidental problems, and a person skilled in the art would like to immediately solve the problem. It was an important issue. In order to omit this complicated deashing process, many studies have been made and proposed to increase the polymerization activity per titanium in the contact component, especially the catalyst component.

In particular, as a recent tendency, a transition metal compound such as titanium halide, which is an active component, is supported on a carrier substance such as magnesium chloride, and when it is subjected to the polymerization of olefins, the polymerization activity per titanium in the catalyst component is dramatically increased. There are many proposals to raise the price.

However, the chlorine contained in magnesium chloride, which forms the mainstream as a carrier substance, has a drawback that it has an adverse effect on the produced polymer as well as the halogen element in titanium halides. Therefore, the effect of chlorine is virtually ignored. There was an unsolved part such as a high activity required, or the need to keep the concentration of magnesium chloride itself low.

The inventors of the present invention have disclosed that, in order to reduce the residual chlorine in the produced polymer while maintaining the polymerization activity per catalyst component and the yield of the stereoregular polymer at a high level, Japanese Patent Application No. 57-20
In 0454, a method for producing a catalyst component for polymerizing olefins was proposed, and the intended purpose was achieved. Further, when the polymerization of olefins, particularly stereoregular polymerization of propylene, 1-butene, etc. is industrially carried out, it is usually necessary to make an electron donating compound such as an aromatic carboxylic acid ester coexist in the polymerization system. It is indispensable in a catalyst that uses a catalyst component having a carrier of (1) as a carrier in combination with an organoaluminum compound. However, this aromatic carboxylic acid ester imparts an ester odor peculiar to the produced polymer, and its removal has become a major problem in the art.

Further, in a so-called highly active supported catalyst, such as a catalyst using a catalyst component having magnesium chloride as a carrier,
Although the activity at the initial stage of polymerization is high, deactivation is large, which causes a problem in the process operation, and when it is necessary to prolong the polymerization time such as block copolymerization, it is practically impossible to use. In order to improve this point, for example, in JP-A-54-94590, a catalyst component is prepared by using magnesium dihalide as a starting material, and an organoaluminum compound, an organic carboxylic acid ester, and M-O-R are prepared.
Although a method of using it for the polymerization of olefins in combination with a compound having a group has been shown, the problem of the odor of the produced polymer has not been solved because an organic carboxylic acid ester is used during the polymerization. As can be seen from the above, very complicated operations are required, and it cannot be said that a practically sufficient one is obtained in terms of performance and sustainability of activity.

Further, the so-called highly active supported catalyst component using magnesium chloride as a carrier has a drawback that its performance is deteriorated as the storage period becomes longer. This can be said to be an extremely serious problem in consideration of the fact that it usually takes several months for storage, transportation, etc. when the catalyst component is industrially used.

Further, although it is necessary to supply the catalyst to a high temperature polymerization tank in an industrial polymerization apparatus, it is known that the performance of the conventional supported catalyst is considerably lowered in such a case. . This is a big problem especially in the so-called continuous polymerization method, and improvement thereof has been a strong demand in the field.

[Problems to be solved by the invention]

The inventors of the present invention have reached the present invention as a result of earnest research in order to solve the problems remaining in such conventional techniques, and make a proactive proposal.

[Means for solving problems]

That is, the features of the present invention are: (A) (a) fatty acid magnesium, (b) basic magnesium carbonate, (c) mono- or diester of aromatic dicarboxylic acid, (d) halogenated hydrocarbon, and ( e) A solid composition obtained by contacting a titanium halide represented by the general formula TiX ₄ (where X is a halogen element) (hereinafter may be simply referred to as titanium halide) repeatedly with the titanium. A catalyst component obtained by contacting a halide and then (f) an organoaluminum compound; (B) a general formula SiRm (OR ') _4- m (wherein R is hydrogen, an alkyl group or an aryl group) , R ′ is an alkyl group or an aryl group, and m is 0 ≦ m ≦ 4) (hereinafter sometimes simply referred to as a silicon compound); and (C) Organoaluminum It is to provide a catalyst for polymerization of olefins consisting um compounds.

As the fatty acid magnesium used in the present invention, saturated fatty acid magnesium is preferable, and magnesium stearate, magnesium octanoate, magnesium decanoate and magnesium laurate are particularly preferable.

The dimono or diester of an aromatic dicarboxylic acid used in the present invention is preferably a mono or diester of phthalic acid or terephthalic acid, for example, dimethyl phthalate, dimethyl terephthalate, diethyl phthalate, diethyl terephthalate, dibropyr phthalate,
Examples thereof include dipropyl terephthalate, dibutyl phthalate, dibutyl terephthalate, diisobutyl phthalate, diamyl phthalate, diisoamyl phthalate, ethyl butyl phthalate, ethyl isobutyl phthalate and ethyl propyl phthalate.

The halogenated hydrocarbon used in the present invention is preferably a chloride of an aromatic or aliphatic hydrocarbon which is liquid at room temperature, for example, propyl chloride, butyl chloride, butyl bromide, propyl iodide, chlorobenzene, benzyl chloride, dichloroethane. , Trichloroethylene, dichloropropane, dichlorobenzene, trichloroethane, carbon tetrachloride, chloroform, methylene chloride and the like, among which propyl chloride, dichloroethane, chloroform, carbon tetrachloride and methylene chloride are preferred.

Examples of the titanium halide represented by the general formula TiX ₄ (wherein X is a halogen element) used in the present invention include TiCl ₄ , TiBr ₄ , TiI _{4 and the} like, among which TiCl ₄ is preferable.

As the silicon compound used in the present invention,
Examples thereof include phenylalkoxysilane and alkylalkoxysilane. Furthermore, examples of phenylalkoxysilane include phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltriisopropoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and the like. , Tetramethoxysilane, tetraethoxysilane, trimethoxyethylsilane, trimethoxymethylsilane, triethoxymethylsilane, ethyltriethoxysilane, ethyltriisopropoxysilane, and the like.

Examples of the organoaluminum compound used in the present invention include trialkylaluminums, dialkylaluminum halides, alkylaluminum dihalides, and mixtures thereof.

When obtaining the solid composition of the present invention, the use ratio of each raw material and the contact conditions are optional, and are not particularly limited, as long as they do not adversely affect the performance of the produced catalyst component. The total amount of fatty acid magnesium and basic magnesium carbonate is 1 g, and the mono- and diesters of aromatic dicarboxylic acid are in the range of 0.01 to 2 g, and the amount of titanium halide is 0.1 g or more, preferably 1 g or more. Further, the halogenated hydrocarbon is used in an arbitrary ratio, but is preferably an amount capable of forming a suspension.

Further, the contact of each raw material is usually carried out at a temperature from 0 ° C. to the boiling point of the titanium halide used for 100 hours or less, preferably 10 hours or less.

A titanium halide is brought into contact with the solid composition obtained after the contact, and at this time, it is also possible to wash with an organic solvent such as n-heptane.

The contact between the solid composition obtained as described above and the organoaluminum compound is usually 100 ° C. or less, preferably 10 ° C, using 0.01 to 100 moles of the organoaluminum compound to 1 mole of titanium in the solid composition. It is carried out at a temperature of ℃ to 80 ℃ for 100 hours or less, preferably 5 seconds to 10 hours.

It is preferable that these series of operations in the present invention are performed in the absence of oxygen and water.

The catalyst component produced as described above is combined with the silicon compound and the organoaluminum compound to form an olefin polymerization catalyst. The organoaluminum compound used is 1 in mole ratio per mole of titanium atom in the catalyst component.
Used in the range of up to 1000, and the silicon compound has a molar ratio of 1 or less per mol of the organoaluminum compound, preferably 1 or less.
Used in the range of 0.005-0.5.

The polymerization can be carried out in the presence or absence of an organic solvent, and the olefin monomer can be used in either a gas or liquid state. Polymerization temperature is 200
℃ or less, preferably 100 ℃ or less, the polymerization pressure is 100kg /
cm ² · G or less, preferably 50 kg / cm ² · G or less.

The olefins homopolymerized or copolymerized using the catalyst produced by the method of the present invention are ethylene, propylene,
1-butene, etc.

〔Example〕

 Specific examples will be described below.

Example 1 << Preparation of Catalyst Components >> Capacity of 500 m fully replaced with nitrogen gas and equipped with stirrer
A round-bottomed 1-liter flask was charged with 10 g of magnesium stearate, 2 g of basic magnesium carbonate, 1.6 g of dibutyl phthalate and 25 ml of methylene chloride to make a suspension, and 1
Stir for hours. Then add 100 ml of TiCl _{4 to} this suspension and
The temperature was raised to 110 ° C., and the mixture was reacted for 2 hours under stirring. After completion of the reaction, it was washed 10 times with 100 ml of n-heptane at 40 ° C, and fresh TiCl _{4 was} added.
100 ml was added and reacted at 110 ° C. for 2 hours with stirring.

After the reaction was completed, it was cooled to 40 ° C, and then 100 ml of n-heptane
The washing with was repeated, and when no chlorine was detected in the washing liquid, the washing was terminated to obtain a solid composition.
Next, 3 g of the solid composition was placed in a round-bottomed flask having an internal volume of 500 ml, 100 ml of n-heptane and triethylaluminum in an amount corresponding to 2 mol per 1 mol of Ti atom in the solid composition were added, and the mixture was stirred at room temperature for 1 hour. After treating under stirring for time, 200 ml of n-heptane at room temperature was washed 5 times to obtain a catalyst component. At this time, the titanium content in the catalyst component was measured and found to be 3.12% by weight.

<< Polymerization >> 700 ml of n-heptane was charged into an autoclave with an internal volume of 2.0, which was completely replaced with nitrogen gas, and 301 mg of triethylaluminum was added while maintaining a nitrogen gas atmosphere.
32 mg of phenyltriethoxysilane and then 0.3 mg of the above catalyst component as titanium atoms were charged. Then hydrogen gas 300
6 ml while charging ml and raising the temperature to 70 ° C and introducing propylene gas
Polymerization was carried out for 4 hours while maintaining the pressure of g / cm ² · G.
After completion of the polymerization, the solid polymer obtained was separated, heated to 80 ° C. and dried under reduced pressure. On the other hand, the amount of the polymer dissolved in the polymerization solvent by condensing the liquid is (A), and the amount of the solid polymer is (B). Also, the obtained solid polymer was heated to 6 with boiling n-heptane.
It is extracted with time to obtain a polymer insoluble in n-heptane, and this amount is designated as (C).

The polymerization activity (D) per catalyst component is calculated by the formula Express with.

Further, the yield (E) of the crystalline polymer is calculated by the formula The yield (F) of all crystalline polymer is expressed by I asked more. Residual chlorine in the produced polymer is represented by (G) and MI of the produced polymer is represented by (H). The results obtained are as shown in Table 1.

Example 2 An experiment was conducted in the same manner as in Example 1 except that the polymerization time was 6 hours. The results obtained are as shown in Table 1.

Example 3 A catalyst component was prepared in the same manner as in Example 1 except that the treatment with triethylaluminum was carried out at 0 ° C. The titanium content in the solid content at this time was 2.98% by weight. An experiment was conducted in the same manner as in Example 1 during the polymerization. The results obtained are as shown in Table 1.

Example 4 An experiment was conducted in the same manner as in Example 1 except that the treatment with triethylaluminum was performed at 50 ° C. The titanium content in the solid content at this time was 3.06% by weight. An experiment was conducted in the same manner as in Example 1 during the polymerization. The results obtained are as shown in Table 1.

Example 5 An experiment was conducted in the same manner as in Example 1 except that triethylaluminum was used in an amount corresponding to 4 mol per mol of Ti atom. The titanium content in the solid content at this time is
It was 3.01% by weight. An experiment was conducted in the same manner as in Example 1 during the polymerization. The results obtained are as shown in Table 1.

Example 6 A catalyst component was prepared in the same manner as in Example 1 except that diethylaluminum chloride was used instead of triethylaluminum. The titanium content in the solid content at this time was 3.16% by weight. Example 1 for polymerization
An experiment was conducted in the same manner as in. The results obtained are as shown in Table 1.

[Effect of the invention] When olefins are polymerized using the catalyst component obtained by the present invention, a polymer having higher stereoregularity is obtained as compared with the case of using a catalyst component which is not brought into contact with an organoaluminum compound. The catalyst residue in the produced polymer can be kept to a very low level due to the high activity of the obtained catalyst, and the dechlorination step is not required at all due to the small amount of residual chlorine. The effect of chlorine on the polymer can be reduced.

Chlorine contained in the produced polymer causes corrosion of equipment used in processes such as granulation and molding, and also causes deterioration of the produced polymer itself, yellowing, etc. Has a very important meaning to those skilled in the art.

Further, the feature of the present invention is that not only the big problem of the odor of the produced polymer is solved by not using the aromatic carboxylic acid ester at the time of polymerization, but also the activity of the catalyst per unit time is increased with the progress of the polymerization. It is an object of the present invention to provide a catalyst that can be practically applied not only to homopolymerization but also to copolymerization, by solving the essential drawback of so-called highly active supported catalysts, which greatly decreases.

Conventionally, in industrial olefin polymer production, coexistence of hydrogen at the time of polymerization has been generally considered from the viewpoint of MI control and the like, but a catalyst using a catalyst component having the above magnesium chloride as a carrier coexists with hydrogen. Below, it had the disadvantage that activity and stereoregularity were significantly reduced. However, when the olefins are polymerized in the coexistence of hydrogen using the catalyst obtained by the present invention, the MI of the produced polymer is
The activity and stereoregularity are hardly deteriorated even when the value is extremely high, and such an effect brings an extremely great benefit to those skilled in the art.

Further, the catalyst component or catalyst produced according to the present invention does not show any deterioration in performance due to so-called aging such as storage or transportation, and even if supplied to a high temperature polymerization tank, the performance is hardly deteriorated. It also possesses extremely important characteristics.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining the present invention.

Claims (1)

[Claims] 1. (A) (a) magnesium fatty acid, (b) basic magnesium carbonate, (c) mono- or diester of aromatic dicarboxylic acid, (d) halogenated hydrocarbon, and (e) general formula TiX ₄ ( In the formula, X is a halogen element.) A solid composition obtained by contacting a titanium halide represented by the formula) is repeatedly contacted with the titanium halide, and then with (f) an organoaluminum compound. Catalyst component, (B) General formula SiRm (OR ') _4- m (wherein R is hydrogen, an alkyl group or an aryl group, R'is an alkyl group or an aryl group, and m is 0≤m≤4. A catalyst for olefin polymerization, comprising a silicon compound represented by the formula (1) and an organoaluminum compound (C).