JPH0723403B2 - Olefin polymerization catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention has a high activity when it is subjected to the polymerization of olefins and has a high activity, and a stereoregular polymer can be obtained in an extremely high yield. The catalyst, more specifically, a catalyst component for polymerization of olefins obtained by contacting aluminum hydroxide, dialkoxy magnesium, diester of aromatic dicarboxylic acid, halogenated hydrocarbon, and titanium halide, silicon compound and organoaluminum compound The present invention relates to a catalyst for olefin polymerization, which comprises

[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. The so-called deashing process for removing the catalyst residue was unavoidable because the polymer yield per titanium (hereinafter referred to as the catalyst component and the polymerization activity per titanium in the catalyst component) was low. 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, and those skilled in the art can quickly solve the problem. This is an important issue that is desired. 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 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 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.

[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 need to keep the concentration of magnesium chloride itself low.

The inventors of the present invention have disclosed in Japanese Patent Laid-Open No. 59-91, for the purpose of reducing the residual chlorine in the produced polymer while maintaining the polymerization activity per catalyst component and the main ratio of the stereoregular polymer in the yield.
In 107, a method for producing a catalyst component for polymerization of olefins was proposed, and the initial purpose was achieved.

However, in the case of using the above-mentioned catalyst component having magnesium chloride as a carrier, or the catalyst component obtained in the above-mentioned JP-A-59-91107, the polymerization activity per unit time is high at the beginning of the polymerization, but decreases with the passage of the polymerization time. It is large and becomes a problem in process operation, and when it is necessary to prolong the polymerization time such as block copolymerization, it is practically impossible to use.

The present inventors have achieved the present invention as a result of earnest research in order to solve the problems left over in the prior art and to further improve the quality of the polymer produced.

[Means for solving problems]

That is, the features of the present invention are: (A) (a) aluminum hydroxide, (b) dialkoxymagnesium, (c) diester of aromatic dicarboxylic acid, (d) halogenated hydrocarbon, and (e) General formula Ti
A composition obtained by contacting with a titanium halide represented by X ₄ (where X is a halogen element) (hereinafter, may be simply referred to as titanium halide) is repeatedly repeated twice with the titanium halogen. (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, m Is a silicon compound represented by 0 ≦ m ≦ 4 (hereinafter may be simply referred to as a silicon compound); and (C) an olefin polymerization catalyst comprising an organoaluminum compound.

As dialkoxy magnesium used in the present invention, diethoxy magnesium, dibutoxy magnesium, diphenoxy magnesium, dipropoxy magnesium, di-sec-butoxy magnesium, di-tert-
Examples thereof include butoxy magnesium, diisopropoxy magnesium and the like, among which diethoxy magnesium and dipropoxy magnesium are preferable.

The diester of aromatic dicarboxylic acid used in the present invention is preferably a diester of phthalic acid or terephthalic acid, for example, dimethyl phthalate, dimethyl terephthalate, diethyl phthalate, diethyl terephthalate, dipropyl phthalate, dipropyl terephthalate, dibutyl phthalate, dibutyl. Examples thereof include terephthalate, diisobutylphthalate, diamylphthalate, diisoamylphthalate, ethylbutylphthalate, ethylisobutylphthalate and ethylpropylphthalate.

The halogenated hydrocarbon used in the present invention is preferably a chloride of an aromatic or aliphatic hydrocarbon which is liquid at room temperature, and examples thereof include propyl chloride, butyl chloride, butyl bromide, propyl iodide, o-dichlorobenzene and benzyl. Examples thereof include chloride, dichloroethane, trichloroethylene, dichloropropane, dichlorobenzene, trichloroethane, carbon tetrachloride, chloroform and methylene chloride, and among them, o-dichlorobenzene, 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. Further examples of phenylalkoxysilanes include phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltriisopropoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane and the like. Examples of the alkylalkoxysilane include tetramethoxysilane, tetraethoxysilane, trimethoxyethylsilane, trimethoxymethylsilane, triethoxymethylsilane, ethyltriethoxysilane, and ethyltriisopropoxysilane.

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

When obtaining the catalyst component in the present invention, the use ratio of each raw material, contact conditions, etc., are optional and are not particularly limited, as long as they do not adversely affect the performance of the catalyst component to be produced. The diester of the aromatic dicarboxylic acid is in the range of 0.01 to 2 g, preferably 0.1 to 1 g, and the titanium halide is in the range of 0.1 g or more, preferably 1 g or more based on 1 g of the total amount of aluminum oxide and dialkoxymagnesium. Further, the halogenated hydrocarbon is used in an arbitrary ratio, but is preferably an amount capable of forming a suspension.

In this case, the contact order and contact method of the respective raw materials forming the catalyst component are not particularly limited, but as the first embodiment, the composition obtained after crushing aluminum hydroxide and dialkoxymagnesium, Obtained after contacting with a diester of an aromatic dicarboxylic acid and a titanium halide in the presence of a halogenated hydrocarbon, or, in a second embodiment, grinding an aluminum hydroxide, dialkoxymagnesium and a diester of an aromatic dicarboxylic acid. It is preferred to contact the composition with a titanium halide in the presence of a halogenated hydrocarbon.

The pulverization of aluminum hydroxide and dialkoxymagnesium in the first embodiment is usually carried out for 5 minutes or more by using a ball mill, a vibration mill or the like, and the obtained composition and diester of aromatic dicarboxylic acid and titanium halide are mixed. The contacting is carried out in the presence of a halogenated hydrocarbon, usually in the temperature range from 0 ° C. to the boiling point of the titanium halide used, for 5 minutes to 100 hours.

The pulverization of aluminum hydroxide, dialkoxymagnesium and diester of aromatic dicarboxylic acid in the second embodiment is usually carried out by using a ball mill, a vibration mill or the like.
The resulting composition is contacted with the titanium halide for at least 0 minutes, usually at 0 ° C. in the presence of a halogenated hydrocarbon.
To the boiling point of the titanium halide used for 5 minutes to 100 hours.

It is necessary to contact the composition obtained after contacting each component constituting the catalyst component with the titanium halide twice more, and it is possible to wash the composition using an organic solvent such as n-heptane. Is.

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 has broad peaks near 2θ = 32 ° and around 50 ° in its X-ray spectrum, and is used in combination with the above-mentioned silicon compound and organoaluminum compound to form a catalyst for olefin polymerization. Form. The organoaluminum compound used is used in a range of 1 to 1000 in molar ratio per mole of titanium atom in the catalyst component, and the silicon compound is 1 or less in molar ratio per mole of organoaluminum compound, preferably 0.005 to 0.5. Used in the range of.

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 100 Kg / c
m ² · G or less, preferably 50 kg / cm ² · G or less.

Olefins homopolymerized or copolymerized using the catalyst of the present invention are ethylene, propylene, 1-butene and the like.

〔The invention's effect〕

When the olefins are polymerized using the catalyst obtained according to the present invention, the resulting polymer has extremely high stereoregularity and, of course, has a very high activity, so that the catalyst in the resulting polymer is The residue can be kept extremely low,
Moreover, since the amount of residual chlorine is so negligible that no deashing step is required at all, the effect of chlorine on the produced polymer can be substantially eliminated.

Chlorine contained in the generated polymer causes corrosion of equipment used in processes such as granulation and molding, and also causes deterioration of the generated polymer itself, yellowing, etc., which can be substantially eliminated. This is extremely important to those skilled in the art.

Further, a feature of the present invention is that the activity of the catalyst component per unit time is significantly reduced with the progress of polymerization,
It is an object of the present invention to solve the essential drawbacks of so-called highly active supported catalysts and to provide a catalyst that can be practically applied not only to homopolymerization but also to copolymerization.

Further, in industrial production of olefin polymers, coexistence of hydrogen at the time of polymerization is generally considered from the viewpoint of MI control and the like, but the catalyst component using magnesium chloride as a carrier is active in the presence of hydrogen. And the stereoregularity is significantly reduced. However, when the olefins are polymerized in the coexistence of hydrogen using the catalyst obtained according to the present invention, the activity and stereoregularity are almost decreased even when the MI of the produced polymer is extremely high. However, such an effect brings an extremely great benefit to those skilled in the art.

〔Example〕

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

Example 1 [Preparation of catalyst components] Aluminum hydroxide 5 g and diethoxy magnesium 45
In a nitrogen gas atmosphere, g is charged into a vibrating millpot with a capacity of 1.0 filled with 4/5 of the total volume of 25 mmφ stainless steel balls and crushed at room temperature for 1 hour at a frequency of 1430 v.pm and a swing of 3.5 mm. Done. 5.5 g of the composition obtained by the above grinding process and 15 ml of o-dichlorobenzene were placed in a 500 ml round-bottomed flask fully replaced with nitrogen gas and equipped with a stirrer, and dibutyl phthalate 1.8 was added under stirring. ml
And 200 ml of TiCl ₄ were added, the temperature was raised to 110 ° C., and the reaction was carried out with stirring for 2 hours. After completion of the reaction, n-heptane 20 at 40 ℃
Wash 10 times with 0 ml and freshly use 200 ml of TiCl ₄ at 40 ℃ for 1
After washing twice, 200 ml of TiCl ₄ was further added and reacted at 110 ° C. for 2 hours while stirring.

After the reaction was completed, it was cooled to 40 ° C, and then 200 ml of n-heptane
The cleaning was repeated, and when chlorine was not detected in the cleaning liquid, the cleaning was completed and the catalyst component was used. At this time, the solid content of the catalyst component was separated, and the titanium content in the solid content was measured and found to be 2.68% by weight.

[Overlap]

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.
64 mg of phenyltriethoxysilane and then 0.3 mg of the above catalyst component as titanium atoms were charged. Then hydrogen gas 120
While charging ml and raising the temperature to 70 ° C and introducing propylene gas
Polymerization was carried out for 4 hours while maintaining a pressure of 6 kg / 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). Further, the obtained solid polymer is 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. Residual chlorine in the produced polymer is represented by (G) and MI of the produced polymer is represented by (H). The results obtained are the first
As shown in the table.

Example 2 The polymerization time was set to 6 hours, and the catalyst component was set to a titanium atom of 0.
An experiment was conducted in the same manner as in Example 1 except that 2 mg was charged. The results obtained are as shown in Table 1.

Example 3 An experiment was conducted in the same manner as in Example 1 except that 1.5 g of dipropyl phthalate was used. The titanium content in the solid content at this time was 3.01% by weight. An experiment was carried out in the same manner as in Example 1 except that 70 mg of phenyltriethoxysilane was used in the polymerization. The results obtained are as shown in Table 1.

Example 4 5 g of aluminum hydroxide, 45 g of diethoxy magnesium and 15 g of dipropyl phthalate were pulverized in the same manner as in Example 1. 6 g of the obtained composition was sufficiently replaced with nitrogen gas, placed in a 500 ml round bottom flask equipped with a stirrer, charged with 15 ml of o-dichlorobenzene and 200 ml of TiCl ₄ and heated to 110 ° C. The reaction was allowed to proceed for 2 hours with stirring. After completion of the reaction, it was washed 10 times with 200 ml of n-heptane at 40 ° C, and once again with 200 ml of TiCl ₄ at 40 ° C.
200 ml of Cl ₄ was added, and the mixture was reacted at 90 ° C. for 2 hours with stirring. After completion of the reaction, the reaction mixture was cooled to 40 ° C., and further washed with 200 ml of n-heptane was repeated. The titanium content in the solid content at this time was 2.71% 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.

[Brief description of drawings]

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

Claims (2)

[Claims] 1. A) (a) aluminum hydroxide, (b)
In contact with dialkoxy magnesium (c) diester of aromatic dicarboxylic acid, (d) halogenated hydrocarbon and (e) titanium halide represented by the general formula TiX ₄ (where X is a halogen element). A catalyst component obtained by contacting the resulting composition with the titanium halide twice more, (B) General formula SiRm (OR ') 4-m (wherein R is hydrogen, an alkyl group or an aryl group). And R ′ is an alkyl group or an aryl group, and m is 0 ≦ m ≦ 4.), And (C) an organoaluminum compound, which is a catalyst for olefin polymerization. . 2. The catalyst component (A) is obtained by contacting a co-ground composition of components (a) and (b) with components (c) and (e) in the presence of component (d). The composition (e) is repeatedly contacted twice with the above composition, or the co-ground composition of the components (a), (b) and (c) is added in the presence of the component (d) to the component (e). The catalyst for polymerization of olefins according to claim (1), which is obtained by repeatedly contacting the composition obtained by contacting with the component (e) twice.