JP2514028B2 - Solid catalyst component for olefin polymerization - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has a high activity when subjected to the polymerization of olephins, and is capable of obtaining a stereoregular polymer in a high yield. It relates to a performance solid catalyst component.

[Prior art]

Recently, as a catalyst for the polymerization of olefins such as propylene, in place of the conventionally known catalyst component of titanium trichloride, many new types of catalysts in which titanium, which is an active component, is supported on magnesium chloride together with an electron donor have been developed. Proposed.

The earliest of these was developed by co-milling a complex of an organic monocarboxylic acid ester as an electron donor and titanium tetrachloride with magnesium chloride, or an organic monocarboxylic acid as an electron donor. There is a product obtained by treating a co-ground product of an acid ester and magnesium chloride with titanium tetrachloride.

However, they cannot be said to have satisfactory properties for use on an industrial scale, and those which improve various properties, for example, diethoxymagnesium instead of magnesium chloride, and special electron donors are used. Various proposals have been made for those using a compound, or those obtained by modifying the combination method of the above-mentioned substances, the contact means and the like.

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
A method of combining a compound having a —O—R group and the like for use in the polymerization of olefins is disclosed, and JP-A-57-
In 63310, various catalysts as electron donors, magnesium chloride in active form, and a titanium compound are combined to prepare a catalyst component, and further Si—O bond or Si—
A method for polymerizing propylene using a compound having an N bond and an organoaluminum compound is disclosed.

[Problems to be solved by the invention]

In the prior art, chlorine contained in magnesium chloride, which occupies the main stream as a carrier material, has a drawback that it adversely affects the produced polymer, like the halogen element in titanium halides. On the other hand, it is required that the activity of chlorine be substantially negligible, or that the concentration of magnesium chloride itself be kept low.

Further, when a catalyst component having the above magnesium chloride as a carrier is used in combination with an organoaluminum compound to polymerize olefins, particularly when stereoregular polymerization of propylene, 1-butene, etc. is carried out industrially, when carrying out the polymerization reaction. It is essential to use an organic monocarboxylic acid ester as an electron donor. However, in this case, it is necessary to use an extremely large amount of organic monocarboxylic acid ester, and as a result, there has been a problem that a peculiar ester odor is imparted to the produced polymer.

Furthermore, in so-called highly active supported catalysts such as catalysts using a catalyst component having magnesium chloride as a carrier, the activity at the initial stage of polymerization is high, but deactivation with time is large and it becomes a problem in process operation, and block copolymerization It was virtually impossible to use it if the polymerization time was longer.

JP-A-54-94590 has been proposed to improve this point, but as is clear from the description of the publication, in this case, an organic carboxylic acid ester is used both during catalyst preparation and during polymerization. Is needed.
Generally, the organic carboxylic acid ester contained in the catalyst is
By treatment with titanium halide or washing with an organic solvent, the amount of odor of the produced polymer is negligible. However, the organic carboxylic acid ester used during the polymerization is extremely large amount as compared with the amount contained in the catalyst as described above, and when the polymerization is carried out in a liquid or gaseous monomer, almost all of it is At present, it is contained in the produced polymer, and accordingly,
It can be said that the problem of the odor of the produced polymer cannot be solved as long as the organic carboxylic acid ester is used during the polymerization. Further, as can be seen from the examples, the method disclosed in the above publication requires extremely complicated operations and the obtained catalyst is practically sufficient in terms of performance and sustainability of activity. That is not the case.

The present inventors have conducted intensive studies to solve the problems remaining in the conventional techniques, and as a result, have succeeded in providing a novel solid catalyst component for polymerization of olefins according to the present invention.

[Means for solving problems]

According to the present invention, a substance (a) obtained by reacting a magnesium metal powder with a 2-fold or more molar amount of an alkyl monohalide in the presence of dialkoxymagnesium and a diester of phthalic acid (b) are co-ground. A solid catalyst component for polymerizing olefins, which comprises connecting the obtained product with titanium tetrachloride (c).

In order to obtain a substance obtained by the reaction of the above-mentioned (a) metallic magnesium powder with an alkyl monohalide in the present invention (hereinafter simply referred to as (a) substance), a commercially available metallic magnesium powder and an alkyl monohalide are used. And are reacted in the presence of dialkoxymagnesium. At this time, the alkyl monohalide must be used in an amount of 2 mol or more per 1 mol of the magnesium metal powder,
Dialkoxy magnesium is used in the range of 0.01 to 1 g per 1 g of metal magnesium powder. Further, the reaction temperature and the reaction time are arbitrary as long as the above reaction proceeds sufficiently,
Although not particularly limited, it is usually carried out at 20 ° C. or higher for 10 minutes or longer, preferably 40 ° C. or higher for 30 minutes or longer. When the IR spectrum of the substance (a) obtained by this reaction is measured, absorption of an alkyl group is observed.

The alkyl monohalide used in the production of the substance (a) is preferably an aliphatic hydrocarbon chloride that is liquid at room temperature, and examples thereof include n-propyl chloride, isopropyl chloride, n-butyl chloride, and the like. Examples thereof include isobutyl chloride, pentyl chloride, hexyl chloride and octyl chloride.

The dialkoxymagnesium used in the production of the substance (a) is preferably one having an alkyl group having 1 to 5 carbon atoms, and examples thereof include diethoxymagnesium, dipropoxymagnesium, and dibutoxymagnesium.

Examples of the (b) phthalic acid diester in the present invention include dimethyl phthalate, diethyl phthalate, diisopropyl phthalate, dipropyl phthalate, dibutyl phthalate, diisobutyl phthalate, diamyl phthalate, diisoamyl phthalate, ethyl butyl phthalate, ethyl isobutyl phthalate and ethyl. Propyl phthalate etc. can be mentioned as an example.

When obtaining the solid catalyst component in the present invention, the use ratio of each raw material constituting the solid catalyst component is arbitrary and is not particularly limited as long as it does not adversely affect the performance of the produced solid catalyst component. However, the amount of the diester of phthalic acid (b) described above (hereinafter may be simply referred to as (b) substance) is in the range of 0.01 to 1 g, relative to 1 g of the substance (a), and it is usually 4 g of the above (c). Titanium chloride is in the range of 0.1 g or more, preferably 1 g or more.

The co-milling of the substance (a) and the substance (b) is usually performed by using a ball mill or a vibration mill and a similar mill.
It is carried out for not less than 1 minute and preferably not less than 30 minutes.

The contact between the composition obtained by the above-mentioned pulverization and titanium tetrachloride is usually carried out in the temperature range from -10 ° C to the boiling point of titanium tetrachloride for 10 minutes to 100 hours.

The composition obtained after the above contact can be repeatedly contacted with titanium tetrachloride, and the obtained composition can be n
It is also possible to wash with an organic solvent such as heptane. These are all included in one aspect in the practice of the present invention.

It is preferable that the series of operations relating to the preparation of the above solid catalyst component in the present invention is carried out in the absence of oxygen and water.

The solid catalyst component prepared as described above is combined with an organoaluminum compound to form a catalyst for polymerizing olefins. At this time, a piperidine derivative or Si-
It is preferable to coexist with an electron donating compound other than the aromatic carboxylic acid ester such as a silicon compound having an O bond.

As the organoaluminum compound used in the present invention, trialkylaluminum is preferably used in an amount of 1 to 1000 mol per g of titanium in the solid catalyst component, and the electron donating compound is 1 or less in molar ratio to the organoaluminum compound. , Preferably in the range of 0.005 to 1.0.

The polymerization reaction using the solid catalyst component for olefin polymerization according to the present invention can be carried out in the presence or absence of an organic solvent, and the olefin monomer used is in a gas or liquid state. However, it can be used. The polymerization temperature is 200 ° C or lower, preferably 100 ° C or lower, and the polymerization pressure is 100 kg / cm ² · G or lower, preferably 50 kg / cm ²
・ G or less.

The olefins homopolymerized or copolymerized using the solid catalyst component for olefin polymerization according to the present invention are ethylene, propylene, 1-butene and the like.

〔The invention's effect〕

When olefins are polymerized using the solid catalyst component for olefin polymerization according to the present invention, the polymer produced has extremely high stereoregularity. Furthermore, since the catalyst activity shows an unexpectedly high value, the amount of catalyst residue present in the produced polymer can be suppressed to an extremely low level. The effect of chlorine can be reduced to the extent that no ash step is required.

Since chlorine remaining in the produced polymer causes corrosion of equipment used in steps such as granulation and molding, it also causes deterioration of the produced polymer itself, yellowing, etc. Obtaining is of great benefit to the art.

Further, according to the present invention, by not adding the organic carboxylic acid ester at the time of the polymerization, it is possible to solve the big problem that the ester odor adheres to the produced polymer.

Furthermore, conventionally, the activity per unit time of the catalyst was significantly reduced with the progress of polymerization, which was a common defect in so-called highly active supported catalysts, but in the solid catalyst component according to the present invention, Since the decrease in activity with the lapse of polymerization time is extremely small compared to the conventionally known catalysts, it is useful even when the polymerization time such as copolymerization is made longer, and a higher polymerization pressure is adopted. Because of the large increase in activity in such cases, it can be widely used in bulk polymerization and gas phase polymerization, which have recently received attention.

In addition, in the 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 conventional magnesium chloride is used as a carrier and organic carboxylic acid ester is used. The catalyst had a drawback that its activity and stereoregularity were significantly reduced in the presence of hydrogen. However, when the polymerization of olefin is carried out in the presence of hydrogen using the solid catalyst component according to the present invention, even when the MI of the produced polymer is extremely high,
The activity and stereoregularity are not reduced. Such an effect has been strongly desired by those skilled in the art. Further, in the industrial production of polyolefin, the bulk specific gravity of the produced polymer becomes a very big problem in terms of the ability of the polymerization apparatus, the ability of the post-treatment step, etc., but the solid catalyst component according to the present invention has this point. Also has extremely excellent characteristics.

[Examples and comparative examples]

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

Example 1. (1) (a) Preparation of substance Using a round bottom flask with a capacity of 2.0 equipped with a stirrer,
After sufficiently substituting this with nitrogen gas, 30 g of metallic magnesium powder, 9.0 g of diethoxymagnesium and 1.2 of n-butyl chloride were charged and reacted at the boiling point of n-butyl chloride for 5 hours. After completion of the reaction, the supernatant was removed, the product was washed with 500 ml of n-butyl chloride three times, and then dried under reduced pressure to obtain a powdery substance.

(2) Preparation of solid catalyst component 20 g of the substance obtained in (1) above and 5.0 ml of dibutyl phthalate were placed under a nitrogen gas atmosphere in a vibrating mill pot with a volume of 1.0 filled with stainless steel balls of 25 mmφ 4/5 of the total volume. Then, it was crushed for 17 hours at a frequency of 1430 v.pm and an amplitude of 3.5 mm.

Using a round bottom flask with a capacity of 500 ml equipped with a stirrer,
After thoroughly substituting with nitrogen gas, 5 g of the solid composition obtained by the above-mentioned pulverization treatment was taken, and TiCl ₄ 200 ml
Was added, and the temperature was raised to 120 ° C. to react for 2 hours. After completion of the reaction, the supernatant was removed, 200 ml of TiCl ₄ was newly added to the product, and the reaction was carried out at 120 ° C for 2 hours. After completion of the reaction, the mixture was cooled to 40 ° C., and the product was washed 10 times with 200 ml of n-heptane to obtain a solid catalyst component.

At this time, the titanium content in the solid catalyst component was measured and found to be 1.69% by weight.

(3) Polymerization Using an autoclave equipped with a stirrer and having an inner volume of 2.0, this was completely replaced with nitrogen gas, and then 193 mg of triethylaluminum, 24 mg of 2,2,6,6-tetramethylpiperidine and 6.0 mg of the solid catalyst component were added. Charged. Then, hydrogen gas 1.8 and liquefied propylene 1.4 were charged and the polymerization reaction was carried out at 70 ° C. for 1 hour. After the completion of the polymerization reaction, the produced polymer is dried under reduced pressure at 80 ° C., and the amount of the obtained product is designated as (A). Further, this product was extracted with boiling n-heptane for 6 hours to obtain a polymer insoluble in n-heptane, and the amount of this product is designated as (B).

The polymerization activity (C) per the solid catalyst component used is represented by the following formula.

The yield (D) of all crystalline polymer is represented by the following formula.

Further, the residual chlorine content in the produced polymer is represented by (E), the MI of the produced polymer is represented by (F), and the bulk specific gravity is represented by (G). The obtained results are shown in Table 1.

Example 2. An experiment was conducted in the same manner as in Example 1 except that the polymerization time was 30 minutes. The obtained results are as shown in Table 1.

Example 3 An experiment was conducted in the same manner as in Example 1 except that the polymerization reaction was performed by the following method.

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 m of triethylaluminum was added while maintaining a nitrogen gas atmosphere.
g, 2,2,6,6-tetramethylpiperidine 37 mg, and then 14.0 mg of the solid catalyst component prepared by the method of Example 1 were charged.
After that, 150 ml of hydrogen gas was charged, the temperature was raised to 70 ° C, and propylene gas was introduced, while maintaining a pressure of 6 kg / cm ² · G.
The polymerization reaction was performed for a time. After the completion of the polymerization reaction, the obtained solid polymer 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 defined as (H), and the amount of the solid polymer is defined as (I). Further, the obtained solid polymer was extracted with boiling n-heptane for 6 hours,
A polymer insoluble in n-heptane was obtained, and this amount is designated as (J).

The polymerization activity (K) per solid catalyst component is represented by the following formula.

Further, the yield (L) of the crystalline polymer is represented by the following formula, The yield (M) of the whole crystalline polymer is determined by the following equation.

Further, residual chlorine in the produced polymer is represented by (N), MI of the produced polymer is represented by (O), and bulk specific gravity is represented by (P). The results obtained are shown in Table 2.

Example 4. An experiment was conducted in the same manner as in Example 3 except that the polymerization time was 2 hours. The results obtained are shown in Table 2.

Example 5. An experiment was conducted in the same manner as in Example 1 except that the same amount of dipropyl phthalate was used instead of dibutyl phthalate. The titanium content in the solid catalyst component at this time was 1.
It was 81% 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. Dibutyl phthalate 7 instead of 5 ml dibutyl phthalate
A solid catalyst component was prepared in the same manner as in Example 1 except that ml was used. The titanium content in the solid catalyst component at this time was 2.16% by weight. Example 1 for polymerization
The experiment was performed in the same manner as described above. The results obtained are as shown in Table 1.

Example 7. An experiment was conducted in the same manner as in Example 1 except that diisobutyl phthalate was used instead of dibutyl phthalate.
The titanium content in the solid catalyst component was 1.70% 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.

Comparative Example 1. 20 g of commercially available MgCl ₂ and 5.0 ml of dibutyl phthalate are pulverized under the same conditions as in Example 1. Then, 5 g of the pulverized composition was charged into a glass container having an internal volume of 500 ml under a nitrogen gas atmosphere, 200 ml of TiCl ₄ was added, and a stirring reaction was carried out at 120 ° C. for 2 hours. After completion of the reaction, the supernatant was removed, 200 ml of TiCl ₄ was newly added, and the reaction was carried out at 120 ° C for 2 hours.

After completion of the reaction, it was cooled to 40 ° C. and washed 10 times with 200 ml of n-heptane to obtain a solid catalyst component. At this time, the titanium content in the solid catalyst component was measured and found to be 1.64% by weight.

An experiment was conducted in the same manner as in Example 1 except that 6.0 mg of the above solid catalyst component was used for the polymerization. The results obtained are as shown in Table 1.

Comparative Example 2. An experiment was conducted in the same manner as Comparative Example 1 except that the polymerization time was 30 minutes. The results obtained are as shown in Table 1.

Comparative Example 3. An experiment was performed in the same manner as in Comparative Example 1 except that the polymerization reaction was performed in the same manner as in Example 3. The results obtained are shown in Table 2.

As is clear from comparison between Examples 1 and 2 and Comparative Examples 1 and 2, the catalyst according to the present invention has an extremely small decrease in activity with the passage of polymerization time.

As is clear from comparison between Examples 1 and 3 and Comparative Examples 1 and 3, the catalyst according to the present invention shows a large increase in activity when a higher polymerization pressure is adopted.

[Brief description of drawings]

FIG. 1 is a schematic drawing for helping understanding of the present invention.

Claims (1)

(57) [Claims] 1. A substance (a) obtained by reacting a magnesium metal powder with a 2-fold or more molar amount of an alkyl monohalide in the presence of dialkoxymagnesium and a phthalic acid diester (b) are co-ground. A solid catalyst component for polymerization of olefins, characterized in that the product thus obtained is contacted with titanium tetrachloride (c).