JPH0694487B2 - Catalyst for olefin polymerization - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a high-performance catalyst capable of exerting a high activity when subjected to the polymerization of olephins and obtaining a stereoregular polymer in a high yield. It is related to. More specifically, the present invention provides a product obtained by contacting a substance obtained by reacting a magnesium metal powder with an alkyl monohalide in the presence of iodine in the absence of a solvent, and a diester of phthalic acid. The present invention relates to a catalyst for olefin polymerization, which comprises a solid catalyst component obtained by contacting a product with TiCl ₄ and a di- or tetra-substituted piperidine derivative and an organoaluminum compound.

2. Description of the Related Art Recently, there are many catalysts in which titanium, which is an active component, is supported on magnesium chloride together with an electron donor as a new type of catalyst in place of the conventionally known catalyst component of titanium trichloride as a catalyst for polymerization of olefins such as propylene. Developed and 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 using magnesium dihalide as a starting material, and an organoaluminum compound, an organic carboxylic acid ester and a MOR are prepared.
A method of combining compounds having a group and the like for use in the polymerization of olefins is disclosed, and in JP-A-57-63310, various esters as electron donors and active forms of magnesium chloride and titanium compounds are disclosed. A method of preparing a catalyst component by combining the above and further polymerizing propylene using a compound having a Si—O bond or a Si—N bond and an organoaluminum compound is disclosed.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the prior art, chlorine contained in magnesium chloride, which occupies the mainstream as a carrier material, has a bad influence on the produced polymer, like the halogen element in titanium halide. Since it has the drawback of exerting such a problem, it is required that the activity be substantially high enough to ignore the effect of chlorine, or measures such as keeping the concentration of magnesium chloride itself low are taken.

In addition, when a catalyst component having the above magnesium chloride as a carrier is used in combination with an organoaluminum compound, polymerization of olefins, particularly propylene, when stereoregular polymerization of 1-butene or the like is industrially carried out, 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 treated in an amount such that the odor problem of the polymer produced can be ignored by treatment with a titanium halide or washing with an organic solvent. 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, so that 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, the method disclosed in the publication, as can be seen from the examples,
The fact is that the catalyst obtained requires extremely complicated operations and is not practically sufficient in terms of performance and sustainability of activity.

The inventors of the present invention have conducted extensive studies to solve the problems remaining in the prior art, and as a result, have succeeded in providing a novel catalyst for olefin polymerization, according to the present invention.

Means for Solving the Problems According to the present invention, (A) (a) a substance obtained by reacting a metal magnesium powder with 2 times or more moles of an alkyl monohalide in the presence of iodine in the absence of a solvent And a product obtained by contacting (b) a diester of phthalic acid with (c)
Solid catalyst component obtained by contact with TiCl ₄ ; (B) General formula (Wherein R ¹ , R ² , R ³ and R ⁴ are hydrogen or an alkyl group which may have a substituent, and at least one of R ¹ and R ² is an alkyl group, and , At least one of R ³ and R ⁴ is an alkyl group) and a (C) organoaluminum compound, and a catalyst for olefin polymerization. .

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 absence of an organic solvent and in the presence of iodine. At this time, the alkyl monohalide needs to be used in an amount of 2 mol or more per 1 mol of the metal magnesium powder.
Further, the reaction temperature and the reaction time are arbitrary as long as the above reaction proceeds sufficiently and are not particularly limited, but usually 20 ° C. or higher for 10 minutes or longer, preferably 40 ° C. or higher for 30 minutes or longer. . This reaction is a Grineer type reaction, and the absorption of an alkyl group is observed when the IR spectrum of the substance (a) obtained by the reaction is measured.

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

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.

The above-mentioned (B) piperidine derivative in the present invention is preferably a di- or tetra-substituted derivative, specifically, a general formula (In the formula, R ¹ , R ² , R ³ , and R ⁴ are hydrogen or an alkyl group which may have a substituent, and at least one of R ¹ and R ² is an alkyl group, At least one of R ³ and R ⁴ is an alkyl group.). As a more specific example, Among them, 2,2,6,6-tetramethylpiperidine is preferable.

Examples of the organoaluminum compound (C) in the present invention include trialkylaluminums, dialkylaluminum halides, alkylaluminum dihalides, and mixtures thereof. Among them, trialkylaluminums are preferable, and triethylaluminums are more preferable. And triisobutylaluminum are particularly preferred.

When the solid catalyst component (A) in the present invention is obtained, 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 solid catalyst component to be produced. Usually, the amount of the diester of phthalic acid of (b) above (hereinafter sometimes simply referred to as (b) substance) is 0.01 to 1 g of (a) substance.
TiCl ₄ of the above (c) (hereinafter simply referred to as (c)
Sometimes called a substance. ) Is in the range of 0.1 g or more, preferably 1 g or more.

At this time, the order and method of contacting the respective raw material substances constituting the solid catalyst component are not particularly limited. A preferred embodiment is a method in which the substance (a) and the substance (b) are pulverized by a ball mill or a vibration mill and a similar pulverizer, and the resulting composition is brought into contact with the substance (c).

The pulverization of the substance (a) and the substance (b) is usually carried out for 10 minutes or longer, preferably 30 minutes or longer, and the composition obtained by the pulverization is contacted with the substance (c). Is usually carried out in the temperature range of -10 ° C to the boiling point of substance (c) for 10 minutes to 100 hours.

The composition obtained after the above contact can be repeatedly contacted with the substance (c), and the composition obtained can be washed with an organic solvent such as n-heptane. These are all included in one aspect in the practice of the present invention.

The series of operations for preparing the solid contact component (A) in the present invention is preferably carried out in the absence of oxygen and water.

The solid catalyst component (A) prepared as described above is combined with the piperidine derivative (B) and the organoaluminum compound (C) to form the catalyst for olefin polymerization according to the present invention. .

The organoaluminum compound (C) used is used in an amount of 1 to 1000 mol per g atom of titanium in the solid catalyst component, and the piperidine derivative has a molar ratio to the organoaluminum compound of 1 or less, preferably 0.005 to 1.0. Used in a range.

The polymerization reaction using the polymerization catalyst according to the present invention can be carried out in the presence or absence of an organic solvent,
The olefin monomer used can be used in either gas or liquid state. Polymerization temperature is 200 ℃
The following is preferably 100 ℃ or less, the polymerization pressure is 100 Kg / cm ²
· G or less, preferably 50 kg / cm ² · G or less.

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

Effect of the Invention When olefins are polymerized using the catalyst for olefin polymerization according to the present invention, the resulting polymer has extremely high stereoregularity. Furthermore, since the catalyst shows an unexpectedly high value, the amount of catalyst residue present in the produced polymer can be suppressed to a very low level, and since the residual chlorine is extremely small, the product is deashed. The effect of chlorine can be reduced to the extent that no steps are 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, there was a common drawback in so-called highly active supported catalysts, in which the activity per unit time of the catalyst was significantly reduced with the progress of polymerization, but in the catalyst according to the present invention, Since the decrease in activity with the passage of time is extremely small compared to conventionally known catalysts, it is also useful when prolonging the polymerization time such as copolymerization, and when a higher polymerization pressure is adopted. Because of the large increase in the activity in, 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 olefin is polymerized in the presence of hydrogen using the catalyst according to the present invention, the activity and stereoregularity do not decrease even when the MI of the produced polymer is extremely high. 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 catalyst according to the present invention also , Has extremely excellent characteristics.

Examples and Comparative Examples The present invention will be described in more detail below with reference to Examples and Comparative Examples.

Example 1. (1) Preparation of substance (a) A round-bottomed flask having a capacity of 2.0 and equipped with a stirrer was used, which was sufficiently replaced with nitrogen gas, and then 30 g of magnesium metal powder, 1.0 g of iodine and n-butyl were used. Chloride 1.2 was charged and reacted at the boiling point of n-butyl chloride for 5 hours. After the reaction was completed, the supernatant was removed and the product was added to 500 ml of n-
After washing with butyl chloride three times, it was dried under reduced pressure to obtain a powdery substance (a).

(2) Preparation of solid catalyst component 20 g of the substance (a) obtained in (1) above and 5.0 ml of dibutyl phthalate were filled in a nitrogen gas atmosphere with a 25 mmφ stainless ball 4/5 of the total volume and vibrated with a volume of 1.0. Charged into a millpot, frequency 1430V · pm · 17 at amplitude 3.5mm
Time crushing process was performed.

Using a round-bottomed flask having a capacity of 500 ml equipped with a stirrer, after sufficiently replacing with nitrogen gas, 5 g of the solid composition obtained by the pulverization treatment was taken, to which 200 ml of TiCl ₄ was added, and 120 ° C. The temperature was raised to 2, and the reaction was performed for 2 hours. After the reaction was completed, the supernatant was removed and 200 ml of TiCl ₄ was newly added to the product.
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 1.61% by weight.

(3) Polymerization Using an autoclave equipped with a stirrer and having an internal 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 completion of the polymerization reaction, the generated polymer
It is dried under reduced pressure at 80 ° C., and the amount obtained 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 amount of residual chlorine 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.

To an autoclave with an agitator having an inner volume of 2.0 completely replaced with nitrogen gas, 700 ml of n-heptane was charged, and 301 mg of triethylaluminum while maintaining a nitrogen gas atmosphere, 2,
37 mg of 2,6,6-tetramethylpiperidine 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., propylene gas was introduced, and the pressure of 6 kg / cm ² · G was maintained for 1 hour.
A polymerization reaction was performed. 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 that is 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 is extracted with boiling n-heptane for 6 hours to obtain a polymer insoluble in n-heptane, 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 all crystalline polymer is calculated by the following formula.

Furthermore, residual chlorine in the produced polymer (N)
MI is represented by (O) and bulk specific gravity is represented by (P). The obtained results are as 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 obtained results are as 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 78% 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. 7 ml of dibutyl phthalate instead of 5 ml of dibutyl phthalate
A solid catalyst component was prepared in the same manner as in Example 1 except that it was used. The titanium content in the solid catalyst component was 2.08% 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 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 1.64% 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. Commercially available MgCl ₂ 20 g and dibutyl phthalate 5.0 ml were used in Example 1.
Grind under the same conditions as. 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, the mixture 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 result obtained is the second
As shown in the table.

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 (2)

[Claims] 1. (A) (a) magnesium metal powder and 2
With a substance obtained by reacting a double molar amount or more of an alkyl monohalide in the presence of iodine in the absence of a solvent,
(B) A solid catalyst component obtained by contacting a product obtained by contacting with a diester of phthalic acid and (c) TiCl ₄ ; (B) General formula (In the formula, R ¹ , R ² , R ³ , and R ⁴ are hydrogen or an alkyl group which may have a substituent, and at least one of R ¹ and R ² is an alkyl group, and , At least one of R ³ and R ⁴ is an alkyl group), and a (C) organoaluminum compound and a disubstituted or tetrasubstituted piperidine derivative. 2. A substance obtained by reacting the (a) metallic magnesium powder with a 2-fold or more molar amount of an alkyl monohalide in the presence of iodine in the absence of a solvent,
(B) The catalyst for olefin polymerization according to claim 1, wherein the contact with the diester of phthalic acid is carried out by pulverization.