JPH0730129B2 - 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 solid composition obtained by contacting dialkoxymagnesium, phthalic acid diester, aromatic hydrocarbon, and titanium tetrachloride with an organoaluminum compound for polymerization of olefins. The present invention relates to a catalyst for olefin polymerization, which comprises a 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 yield of the polymer per titanium (hereinafter referred to as the catalyst component and the polymerization activity per titanium in the catalyst component) was 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, 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 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 to raise the price.

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 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. 57-200
In 454, a method for producing a catalyst component for polymerization of olefins was proposed, and the intended purpose was achieved. Further, when the polymerization of olefins, particularly the stereoregular polymerization of propylene, 1-butene and the like 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 organic aluminum 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, the so-called highly active supported catalyst component using magnesium chloride as a carrier has a drawback that its performance deteriorates 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 particularly 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) dialkoxymagnesium, (b) phthalic acid diester, (c) aromatic hydrocarbon, and (d) general formula TiX ₄ (wherein X is a halogen). A solid composition obtained by contacting with a titanium halide represented by the element (hereinafter simply referred to as “titanium halide”),
(E) A catalyst component obtained by contacting with an organoaluminum compound; (B) General formula SiR _m (OR ′) _4-m (wherein R is hydrogen, an alkyl group or an aryl group, and R ′ is an alkyl group). Or a silicon compound represented by an aryl group and m is 0 ≦ m ≦ 4 (hereinafter, may be simply referred to as a silicon compound); and (C) an olefin polymerization catalyst comprising an organoaluminum compound. It is in the place of providing.

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 and diisopropoxy magnesium, and among them, diethoxy magnesium and dipropoxy magnesium are preferable.

Examples of the phthalic acid diester used in the present invention include dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diisopropyl phthalate, dibutyl phthalate, diisobutyl phthalate, diamyl phthalate, diisoamyl phthalate, ethyl butyl phthalate, ethyl isobutyl phthalate, ethyl propyl phthalate and the like. Can be given.

The aromatic hydrocarbon used in the present invention is preferably a chloride of an aromatic or aliphatic hydrocarbon that is liquid at room temperature,
Examples thereof include toluene, xylene, ethylbenzene, propylbenzene, butylbenzene and the like.

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 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. Phthalic acid diester is 0.01 to 2 g, preferably 0.1 to 1 g of dialkoxymagnesium.
To 1 g, and titanium tetrachloride in the range of 0.1 g or more, preferably 1 g or more. Further, the aromatic hydrocarbon is used in an arbitrary ratio, but it 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 titanium tetrachloride 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 titanium tetrachloride, or it may be washed with an organic solvent such as n-heptane.

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

After the contact, the obtained composition can be contacted with titanium tetrachloride, or can be washed with an organic solvent such as n-heptane.

The series of operations in the present invention are preferably carried out 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 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 and the like.

〔The invention's effect〕

When the olefins are polymerized using the catalyst component obtained according to the present invention, a polymer having higher stereoregularity than the conventional catalyst is obtained, and the catalyst has a very high activity. Therefore, the catalyst residue in the produced polymer can be suppressed to a very low level, and the effect of chlorine on the produced polymer can be reduced to such an extent that a deashing step is not required at all due to the small amount of residual chlorine. You can

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

In the conventional industrial production of olefin polymers, 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, but conventional catalysts using a magnesium chloride-supported catalyst component are hydrogen. In the coexistence, it had a drawback 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,
Even when the MI is extremely high, the activity and stereoregularity are hardly deteriorated, and such an effect brings a great advantage to those skilled in the art.

Further, the catalyst produced according to the present invention not only shows no deterioration in performance due to so-called aging such as storage and transportation, but also exhibits almost no deterioration in performance even when supplied to a high temperature polymerization tank. It also possesses important characteristics.

Further, in the industrial production of olefin polymers, the bulk specific gravity of the produced polymer becomes a problem, and the catalyst of the present invention also has extremely excellent properties in this respect.

〔Example〕

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

Example 1 <Preparation of catalyst component> 200 m fully replaced with nitrogen gas and equipped with a stirrer
A 10-liter round-bottomed flask was charged with 10 g of diethoxymagnesium and 80 ml of toluene to make a suspension. Next, 20 ml of TiCl ₄ was added to this suspension, the temperature was raised to 70 ° C., and 2.7 ml of dibutyl phthalate was added. Then, the temperature was raised to 115 ° C. and the reaction was carried out for 2 hours with stirring. After completion of the reaction, it was washed 3 times with 100 ml of toluene at 40 ° C, and newly added 80 ml of toluene and 20 ml of TiCl ₄ to 1
The reaction was carried out while stirring at 15 ° C for 2 hours.

After the reaction was completed, it was cooled to 40 ° C, and then 200 ml of n-heptane
Washing with 10 times was performed 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 200 hours, 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 2.66% by weight.

<< Polymerization >> 700 ml of n-heptane was charged into an autoclave with an internal volume of 2.0 l, which was completely replaced with nitrogen gas, and 301 mg of triethylaluminum, 60 mg of phenyltriethoxysilane were added while maintaining a nitrogen gas atmosphere, and then the above-mentioned. The catalyst component was charged as titanium atom in an amount of 0.2 mg. Then 150 ml of hydrogen gas
6k while charging propylene gas 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. 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.

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 2.41% 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 performed 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 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.

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 1 mol of Ti atom. The titanium content in the solid content at this time is
It was 2.38% 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 (1)

[Claims] 1. (A) (a) dialkoxy magnesium,
(B) phthalic acid diester, (c) aromatic hydrocarbon, and (d) general formula TiX ₄ (where X is a halogen element).
(E) a solid catalyst component obtained by bringing an organoaluminum compound into contact with a solid composition obtained by contacting a titanium halide represented by: (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) and (C) an organoaluminum compound. A characteristic catalyst for olefin polymerization.