JPH078889B2 - Catalyst for olefin polymerization - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a stereoregular polymer having a highly active activity and an ordered particle size distribution in an extremely high yield when subjected to the polymerization of olefins. The present invention relates to a high-performance catalyst that can be obtained, more specifically, olefins obtained by heating a solid composition obtained by bringing dialkoxymagnesium, an aromatic dicarboxylic acid diester, a halogenated hydrocarbon and a titanium halide into contact with each other. The present invention relates to a olefin polymerization catalyst comprising a polymerization catalyst component, 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) is low, a 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 recovering device or a regenerating device for them is indispensable, and there are many resources, energy and other incidental problems,
It was an important problem for those skilled in the art to solve it immediately. In order to eliminate this complicated deashing step, many studies have been made and proposed to increase the polymerization activity per catalyst component, especially titanium per catalyst component.

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

[Problems to be solved by the invention]

However, the chlorine contained in magnesium chloride, which forms the mainstream as a carrier substance, has the drawback that it adversely affects the polymer produced as well as the halogen element in titanium halides, and therefore the effect of chlorine is virtually ignored. There was an unsolved part such as a high activity required, or the necessity of keeping the concentration of magnesium chloride itself low.

The inventors of the present invention have disclosed the Japanese Patent Application No. 57-20045 for the purpose of reducing 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.
In 4, we proposed a method for producing catalyst components for the polymerization of olefins and achieved the intended purpose. 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 as a combination with an organoaluminum compound. However, this aromatic carboxylic acid ester imparts an ester odor peculiar to the produced polymer, and its removal is 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 the polymerization is high, the 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 combined with an organic aluminum compound, an organic carboxylic acid ester, a compound having a MOR group, and the like. A method used for the polymerization of olefins is also shown, but since the organic carboxylic acid ester is used during the polymerization, the problem of the odor of the produced polymer has not been solved, and as seen from the examples, it is very In addition to requiring complicated operations, it cannot be said that practically sufficient ones have been obtained in terms of performance and sustainability of activity.

Further, in an industrial polymerization apparatus, it may be necessary to supply the catalyst to a high temperature polymerization tank, but in the case of the conventional supported catalyst, the performance is particularly large, especially the activity, stereoregularity, and bulk specific gravity. Is known to decrease. This is a big problem especially in the so-called continuous slurry polymerization method using an organic solvent, and there has been a strong demand in the art for its improvement.

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) dialkoxymagnesium, (b) diester of aromatic dicarboxylic acid, (c) halogenated hydrocarbon and (d) general formula TIX ₄ (wherein X Is a halogen element.) A catalyst component obtained by heating a solid composition obtained by contacting a titanium halide represented by the formula (hereinafter simply referred to as “titanium halide”); (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) , And sometimes referred to simply as a silicon compound.); And (C) an olefin polymerization catalyst comprising an organoaluminum compound.

Examples of dialkoxy magnesium used in the present invention include diethoxy magnesium, dibutoxy magnesium, diphenoxy magnesium, dipropoxy magnesium, di-sec-butoxy magnesium, di-tert-butoxy magnesium, diisopropoxy magnesium and the like. Among them, diethoxy magnesium and dipropoxy magnesium are preferable.

The aromatic dicarboxylic acid diester used in the present invention is preferably a phthalic acid diester, for example, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diisopropyl phthalate, dibutyl phthalate, diisobutyl phthalate, diamyl phthalate, diisoamyl phthalate, ethyl. Examples thereof include 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 that 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.

The titanium halide used in the present invention is
TiCl ₄ , TiBr ₄ , TiI _{4 and the} like can be mentioned, but TiCl ₄ is particularly preferable.

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

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. With respect to 1 g of dialkoxy magnesium, the diester of aromatic dicarboxylic acid is in the range of 0.01 to 2 g, preferably 0.1 to 1 g, and the titanium halide is
The range 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.

At this time, the order and method of contacting each raw material are not particularly limited, and any appropriate one can be selected.

The solid composition obtained after the contact may be repeatedly contacted with a titanium halide, or the solid composition may be washed with an organic solvent such as n-heptane.

The heat treatment of the solid composition thus obtained is usually 50
It is carried out at a temperature of 0 ° C or higher for 10 hours or less, preferably 5 hours or less.

At this time, the heat treatment can be performed under pressure or reduced pressure.

The catalyst component produced as described above is combined with the silicon compound and the organoaluminum compound to form a catalyst for olefin polymerization. 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 gas or liquid state. Polymerization temperature is 200
℃ or less preferably 100 ℃ or less, the polymerization pressure is 100kg / c
m ² · G or less, preferably 50 kg / cm ² · G or less.

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

〔The invention's effect〕

When olefins are polymerized using the catalyst component obtained according to the present invention, the catalyst residue of the polymer produced can be kept extremely low because the catalyst has a very high activity, and the residual chlorine salt Since the amount is very small, the effect of chlorine on the produced polymer can be reduced to the extent that no deashing step is required.

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. Is extremely important to a person skilled in the art. Furthermore, the feature of the present invention is to solve the big problem of the odor of the produced polymer by not using the aromatic carboxylic acid ester during the polymerization. Not only does it solve the essential drawback of so-called highly active supported catalysts, in which the activity of the catalyst per unit time decreases significantly with the progress of polymerization, and it is practically applicable not only to homopolymerization but also to copolymerization. The present invention is to provide a catalyst that can be applied.

Conventionally, in industrial olefin polymer production, it has been generally said that hydrogen is allowed to coexist at the time of polymerization from the viewpoint of MI control and the like. Below, it had the disadvantage that activity and stereoregularity were significantly reduced. However, when olefins are polymerized in the presence of hydrogen using the catalyst obtained according to 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, in an industrial polymerization apparatus, it may be necessary to supply the catalyst to a high temperature polymerization tank, but in the case of a conventional supported catalyst, the performance, particularly activity, stereoregularity, bulk It is known that specific gravity decreases. This is a big problem especially in the so-called continuous slurry polymerization method using an organic solvent, and there has been a strong demand in the art for its improvement, but the catalyst according to the present invention sufficiently solves this problem.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

Example 1 << Preparation of catalyst components >> Capacity of 200 m fully replaced with nitrogen gas and equipped with a stirrer
A 1-liter round-bottomed flask was charged with 5 g of diethoxymagnesium, 1.6 g of dibutyl phthalate and 25 ml of O-dichlorobenzene to give a suspension, and the mixture was stirred under reflux for 1 hour. Then, this suspension was pumped into 200 ml of TiCl ₄ at room temperature in a 500 ml round-bottomed flask equipped with a stirrer, heated to 120 ° C., reacted for 2 hours with stirring, and the supernatant was removed. New Ti
200 ml of Cl ₄ was added and reacted at 120 ° C. for 2 hours with stirring.
After completion of the reaction, after washing 10 times with 200 ml of n-heptane at 40 ° C,
It was dried under reduced pressure to obtain a solid composition. At this time, the titanium content of the solid composition was 2.67%. Next, 3 g of the solid composition was placed in a round-bottomed flask having an inner volume of 100 ml, which was sufficiently replaced with nitrogen gas, and the mixture was treated at 100 ° C. for 30 minutes to obtain a melting medium component.

<< [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 and 32 mg of phenyltriethoxysilane were charged while maintaining a nitrogen gas atmosphere. I entered. 80 ℃ thereafter
The temperature is raised to 10.0 mg of the catalyst component and 150 ml of hydrogen gas.
Was charged, and the polymerization was carried out for 4 hours while maintaining the pressure of 6 kg / cm ² · G while introducing propylene gas. 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 catalyst by condensing the liquid is (A), and the amount of the solid polymer is (B). The obtained solid polymer was extracted with boiling n-heptane for 6 hours 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. The residual chlorine in the produced polymer is represented by (G), the MI of the produced polymer is represented by (H), and the bulk specific gravity is represented by (I). 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.

Comparative Example 1 The solid composition obtained in Example 1 was used as a catalyst component without heat treatment. An experiment was conducted in the same manner as in Example 1 during the polymerization. The results obtained are as shown in Table 1.

[Brief description of drawings]

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

Claims (1)

[Claims] 1. (A) (a) dialkoxy magnesium,
A solid composition obtained by contacting (b) a diester of an aromatic dicarboxylic acid, (c) a halogenated hydrocarbon and (d) a titanium halide represented by the general formula TiX ₄ (where X is a halogen element). A catalyst component obtained by heat-treating the product; (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, m is 0 ≦ m ≦ 4) and a (C) organoaluminum compound, and a catalyst for olefin polymerization.