JPH0710888B2 - Catalyst 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 catalyst. More specifically, the present invention relates to a substance obtained by reacting a metal magnesium powder with an alkyl monohalide in the presence of iodine in the absence of a solvent, and a diester of phthalic acid at 0 ° C.
For the polymerization of olefins consisting of a solid catalyst component obtained by repeatedly contacting the product obtained by co-pulverization in a temperature range of less than 2 times with titanium tetrachloride and a disubstituted or tetrasubstituted piperidine derivative and an organoaluminum compound It relates to a catalyst.

[Prior art]

Recently, in place of the conventionally well-known titanium trichloride catalyst component as a catalyst for the polymerization of olefins such as propylene, as a new type of catalyst, many titanium compounds, which are active components, have been carried on magnesium chloride together with an electron donor. Has been 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 a compound having a group and the like to polymerize 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.

[Problems to be solved by the invention]

In the prior art, the chlorine contained in magnesium chloride, which occupies the main stream as a carrier material, is the same as the halogen element in titanium halide, with respect to the produced polymer,
Since it has the drawback of having an adverse effect, on the other hand, it is required that the activity of chlorine be substantially negligible, or measures such as keeping the concentration of magnesium chloride itself low are taken. There is.

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, 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 present inventors have conducted intensive studies to solve various problems in the conventional art, and succeeded in providing a novel olefin polymerization catalyst.

[Disclosure of Invention]

The present invention provides: (A) a substance obtained by reacting (a) 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 (b) a diester of phthalic acid. And (c) a solid catalyst component obtained by repeatedly contacting twice the product obtained by co-milling in a temperature range of less than 0 ° C. with (c) titanium tetrachloride; (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 ⁴ is an alkyl group.) And a (C) organoaluminum compound, which is a di- or tetra-substituted piperidine derivative. is there.

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 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.

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 the alkyl group. , R ³ and R ⁴ are at least one of the alkyl groups.). 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 trialkylaluminum, dialkylaluminum halides, alkylaluminum dihalides, and mixtures thereof. Among them, trialkylaluminums are preferable, and triethylaluminum and Triisobutylaluminum is 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.
The amount of titanium tetrachloride (c) is 0.1 g or more, preferably 1 g or more.

The co-grinding of the substance (a) and the substance (b) is performed at a temperature of less than 0 ° C.
It is preferably carried out at a low temperature of -10 ° C or lower for usually 10 minutes or longer, preferably 30 minutes or longer.

The contact between the composition obtained by the co-milling 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 solid catalyst component according to the present invention is prepared by contacting titanium tetrachloride again with the composition obtained after the above contact, and the contact condition at this time is the same as the above contact condition. Well, it can be washed with an organic solvent such as n-heptane before and after the contact.

The series of operations for preparing the solid catalyst component (A) in the present invention is preferably performed 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) is used in an amount of 1 to 1000 mol per g atom of titanium in the solid catalyst component, and the piperidine derivative is used in a molar ratio to the organoaluminum compound of 1 or less, preferably 0.005 to 1.0. To be

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, and the olefin monomer used should be used in either gas or liquid state. You can The polymerization temperature is
200 ℃ or less, preferably 100 ℃ or less, the polymerization pressure is 100k
g / 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.

The catalyst for olefin polymerization according to the present invention, when used for the polymerization of olefins, exhibits an unexpectedly high activity, so that the amount of catalyst residue present in the produced polymer is extremely high. The effect of chlorine can be reduced to such an extent that the product can be kept at a low level and that the residual chlorine is extremely small, so that no deashing step is required for the product.

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 an organic carboxylic acid ester at the time of polymerization, it is possible to solve a big problem that an ester odor adheres to a 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.

Moreover, according to the catalyst of the present invention, a polymer having a high degree of stereoregularity can be obtained.

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.However, 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 polymerization is carried out in the coexistence of hydrogen using the catalyst of the present invention,
The activity and stereoregularity are not reduced 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]

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

Example 1 (1) Preparation of substance (a) A 2.0-round-bottomed flask equipped with a stirrer was used, and this was sufficiently replaced with nitrogen gas.
30 g, 1.0 g of iodine and 1.2 of n-butyl chloride were charged, and the mixture was 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 (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. The mixture was charged into a millpot and subjected to co-milling treatment at a frequency of 1430 V.pm and an amplitude of 3.5 mm for 17 hours in a temperature atmosphere of -15 ° C.

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 co-milling 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 1.82% by weight.

(3) Using an autoclave with an internal volume of 2.0 and a stirrer, which was completely replaced with nitrogen gas, 190 mg of triethylaluminum, 23 mg of 2,2,6,6-tetramethylpiperidine and 5.0 mg of the solid catalyst component 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 carried out in the same manner as in Example 1 except that the polymerization reaction was carried out 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 mg of triethylaluminum was added while maintaining a nitrogen gas atmosphere.
37 mg of 2,2,6,6-tetramethylpiperidine, then Example 1
15.0 mg of the solid catalyst component prepared by the above method was charged. Thereafter, 120 ml of hydrogen gas was charged, the temperature was raised to 70 ° C., and propylene gas was introduced, while maintaining the pressure of 6 kg / cm ² · G and carrying out the polymerization reaction for 1 hour. 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 (H), and the amount of the solid polymer is (I). The obtained solid polymer was extracted with boiling n-heptane for 6 hours to give n-
A polymer insoluble in heptane is 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 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 91% 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 A solid catalyst component was prepared in the same manner as in Example 1 except that the reaction (200 ml) after adding 200 ml of TiCl ₄ in Example 1 (2) was performed at 130 ° C. The titanium content in the solid catalyst component was 2.20% 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 frontier for explaining the present invention.

Claims (1)

[Claims] 1. A substance obtained by reacting (A) (a) a magnesium metal 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) A solid catalyst component obtained by repeatedly contacting twice the product obtained by co-milling phthalic acid diester in the temperature range of less than 0 ° C. with (c) titanium tetrachloride; (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.) A catalyst for olefin polymerization, comprising a di- or tetra-substituted piperidine derivative represented by the formula) and (C) an organoaluminum compound.