JPS6042243B2 - Polymerization method of α-olefins - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for polymerizing highly stereoregular poly-α-olefins using a highly active catalyst system consisting of a special activated titanium component and an organoaluminum compound. .

It is known to polymerize α-olefins such as propylene and butene to stereoregular polyα-olefins using a so-called Ziegler-Natsuta catalyst consisting of Ξ titanium chloride and an organoaluminum compound, and it is not currently being carried out industrially. There is.

In recent years, a method has been developed to increase the activity of the catalyst by supporting the titanium component of the Ziegler-Natsuta catalyst on a carrier, and it is becoming common for ethylene polymerization catalysts, but for α-olefins such as propylene and budene, methyl group,
Useful crystalline polymers cannot be obtained unless alkyl groups such as ethyl groups are sterically controlled to form an isotactic structure. Therefore, merely improving activity as in the case of ethylene polymerization is not enough to make a useful polymerization catalyst. However, controlling the stereoregularity of the resulting polymer is a major problem.

In connection with this, a method of improving the stereoregularity of the produced polymer by adding an electron donor compound as a third component to a carrier-type titanium component in which a titanium compound is supported on magnesium halide and an organoaluminum compound. but,
JP-A-47-9342, JP-A-48-16, JP-A-4
It was proposed in 9-8648 Hisashi.

When propylene is polymerized using a two-component catalyst consisting of a supported titanium component and an organoaluminum compound, the polymerization activity is high, but the crystallinity of the resulting polymer is extremely low.Addition of an electron donor compound improves the crystallinity of the resulting polymer, but The activity decreased significantly, and the crystallinity improvement effect was not sufficient.
It has been difficult to obtain crystalline polypropylene of the same quality as that obtained with the titanium trichloride/diethylaluminum monochloride catalyst system currently used industrially. The present inventor investigated a method for obtaining a highly crystalline poly-α-olefin with high activity, and as a result produced the following results: Composition in which a titanium compound is supported on a magnesium compound (B) Organoaluminum compound (C) Aluminum halide, organic acid ester We have discovered that catalysts consisting of similar complexes are extremely effective.

In conventional methods, the crystallinity of the resulting polymer is improved by complexing an electron donor compound with a titanium compound and/or an organoaluminium compound, but the activity is greatly increased by the action of the electron donor compound. In contrast, in the present invention, a highly crystalline polymer can be efficiently produced by adding an aluminum halide/organic acid ester complex, which is completely different from the electron donor compound. .

The titanium component (4) component used in the method of the present invention is a composition in which a titanium compound is supported on a magnesium compound.

Magnesium compounds used include magnesium halides, magnesium hydroxyhalides, magnesium oxide, and magnesium hydroxide. As the titanium compound, titanium tetrachloride, titanium trichloride, or a complex of these with an electron donor compound is used. Various methods can be used to support the titanium compound on the magnesium compound, and typical examples include the following. The mode of support may be physical or chemical. (1) Co-pulverizing a magnesium compound with a titanium compound.

In this case, in addition to the above-mentioned magnesium compounds and titanium compounds, various metal compounds, electron donor compounds, silicon tetrachloride, polysiloxane, and aluminum halide/organic acid ester complexes may be present in the pulverization. (2)
Heat treatment of magnesium compounds and titanium tetrachloride! let

In this case, the above-mentioned magnesium compound and titanium tetrachloride are reacted, or a composition consisting of a magnesium compound and an electron donor or a complex of an electron donor compound and various metal compounds is prepared, and then heat treatment is performed with titanium tetrachloride. 3 is good even if I let you. Preparation of the prisoner ingredient shown in (1), or (2)
Grinding means are used to prepare compositions consisting of magnesium and various compounds shown in .

The pulverizer used for pulverization may be any conventional pulverizer used for pulverizing powder, such as a ball mill or a vibration mill.

The grinding operation is carried out in a vacuum or in an inert gas atmosphere.
It must be carried out in a state where moisture, oxygen, etc. are almost completely removed.

There are no particular restrictions on the pulverization conditions, but the temperature is generally in the range of 0°C to 50°C, and the pulverization time varies depending on the type of pulverizer, but is usually about 2 to 10 minutes.

When preparing the component (4) directly by co-pulverization as in the case of (1), the proportion of the raw material is adjusted so that the titanium compound is present in the range of 0.1 to 10 wt% in the component (4) as metallic titanium. Adjust and co-grind.

Regarding the heat treatment of the magnesium compound and titanium tetrachloride (2), in the case of magnesium hydroxychloride, magnesium oxide, magnesium hydroxide, etc., a method of direct contact with titanium tetrachloride is used, and in the case of magnesium halide, a method of direct contact with titanium tetrachloride is used. Component (4) is prepared by co-pulverizing magnesium and an electron donor compound, or a complex of this and various metal compounds, and then contacting it with titanium tetrachloride. In this case, the above-mentioned magnesium compound or a composition containing the magnesium compound is suspended in a solution of titanium tetrachloride or its inert solvent, and
After contacting at a temperature of 5°C, an activated titanium component can be obtained by washing free titanium tetrachloride with an inert solvent or drying (if necessary under reduced pressure).

The organic aluminum compound used as component (B) in the method of the present invention has the general formula AlRmX3-m (where R is a hydrocarbon residue, X is an alkoxy group, and hydrogen is
．． 5≦m≦3), such as trimethylaluminum, triethylaluminum,
Tri-n-butylaluminum, tri-JsO-butylaluminum, tri-n-hexylaluminum, diethylaluminum hydride, diethylaluminum ethroxide, etc. can be used.

In the method of the present invention, the ratio of the activated titanium component to the organoaluminum compound used can vary over a wide range, but generally the molar ratio of the organoaluminum compound to titanium metal in the activated titanium component is 1 to 5(1). In particular, the range of 20 to 100 is preferable in order to increase the polymerization activity.

In the method of the present invention, an aluminum halide/organic acid ester complex is used as component (C). As the aluminum halide used for preparing this complex, aluminum trichloride and aluminum tribromide are particularly preferred.
As the organic acid ester, aromatic carboxylic acid ester, aliphatic carboxylic acid ester, and alicyclic carboxylic acid ester are used, such as methyl benzoate, ethyl benzoate, propyl benzoate, phenyl benzoate, ethyl anisate, and naphthoate. Ethyl acid, ethyl acetate, ethyl acrylate,
Examples include ethyl methacrylate and ethyl hexahydrobenzoate. The complex of aluminum halide and organic acid ester can be prepared by a conventional method, for example, by mixing the two at room temperature or by heating the mixture. The method of the present invention uses the general formula R-CH=CFI2, where R
represents an alkyl group having 1 to 10 carbon atoms)
Homopolymerization of olefins, and the above α-olefins,
Or used for copolymerization with ethylene.

The above α-olefins include propylene, butene-1
, hexene-1,4-methylpentene-1, and the like.

For the polymerization reaction according to the method of the present invention, conventional methods and conditions commonly used in the art can be employed.

The polymerization temperature at that time is 20 to 300℃, preferably 50 to 2
The polymerization pressure is in the range of normal pressure to 2 atm, preferably in the range of normal pressure to 1(4) atm. In general, aliphatic, cycloaliphatic, aromatic hydrocarbons, or mixtures thereof, can be used as solvents in polymerization reactions, such as propane, butane, pentane, hexane, heptane,
Cyclohexane, benzene, toluene, etc., and mixtures thereof are preferably used. It is also possible to perform bulk polymerization using the liquid monomer itself as a solvent. Furthermore, it can also be carried out under conditions in which a solvent is substantially absent, that is, by a so-called gas phase polymerization method in which a gaseous monomer and a catalyst are brought into contact. The molecular weight of the polymer produced in the method of the present invention varies depending on the reaction mode, catalyst system, and polymerization conditions, but can be controlled, if necessary, by adding hydrogen, alkyl halides, dialkyl zinc, etc. can.

Examples of the present invention will be shown below.

Examples 1 to 3 Diameter 1271 m (7) Internal volume 600 m containing a steel balls
Prepare a vibrating mill equipped with a grinding pot.

In this pot, in a nitrogen atmosphere, add 2 magnesium chloride.
0.0y1 aluminum chloride/ethyl benzoate complex 10
．． 0y was added and crushed for 2 seconds. After adding 10y1 of the above pulverized product and 200mt of titanium tetrachloride into a 300mt round bottom flask and stirring at 80°C for 2 hours, the supernatant liquid was removed by decantation, and then 200m1 of n-heptane was added.
After stirring at room temperature for 30 minutes, the operation of removing the supernatant liquid by decantation was repeated seven times, and 200 ml of n-heptane was further added to obtain an activated titanium component slurry.

When a part of this activated titanium component slurry was sampled, n-heptane was evaporated, and analyzed, it was found that the activated titanium component contained 1.20 wt% Ti. In a SUS-3S autoclave with an internal volume of 2e, n-heptane 1e1 and the above activated titanium component 0.10y (
0.025 n1M (calculated as a titanium atom), 0.2 ml (1.45 n1M) of triethylaluminum, and a predetermined aluminum chloride/ethyl benzoate complex were charged. After the nitrogen in the autoclave was evacuated using a vacuum pump, hydrogen was charged at a gas phase partial pressure of 0.3 k9/Cl, and then propylene was charged to set the pressure in the gas phase to 2 k9/Clt gauge. The contents of the autoclave were heated, and after 5 minutes the internal temperature was raised to 70°C, and the polymerization pressure was increased to 5k9/cm at 70°C.
Polymerization was continued for 2 hours while charging propylene to maintain the Clt gauge. After cooling the autoclave, purge unreacted propylene, take out the contents, and pass through the mouth for 60 minutes.
It was dried under reduced pressure at °C to obtain a white polypropylene powder. On the other hand, the oral fluid was concentrated to recover an n-heptane soluble amorphous polymer.

For polypropylene powder, the proportion of polymer remaining after boiling n-5 heptane extraction (hereinafter abbreviated as powder ■)
, intrinsic viscosity (135°C, tetralin), bulk specific gravity were measured, and polypropylene powder, amorphous polypropylene yield, and n- to total polymer from powder ■ were measured.
The proportion of O polymer remaining after heptane extraction (total ■, the same applies hereinafter) was determined.

Table 1 shows the results of polymerizations conducted with different amounts of the ethyl benzoate/aluminum chloride complex used. Example 4 Table 1 shows the results of repeating the experiment in the method of Example 2 using 0.35 ml of triisobutylaluminum instead of triethylaluminum.

Comparative Examples 1 to 3 Table 2 shows the results of a comparison using ethyl benzoate in place of the ethyl benzoate/aluminum chloride complex added as the catalyst (C) component during polymerization in the methods of Examples 1 to 4.

Example 5 Magnesium chloride 26.8y, titanium tetrachloride.
Ethyl benzoate complex 3.2y was co-pulverized in the same manner as in Example 1 to prepare an activated titanium component having a titanium content of 1.5 wt%.

Polymerization was carried out in the same manner as in Example 1 using the obtained activated titanium component 0.10y1 triethylaluminum 0.20TrLt1 ethyl benzoate/aluminum chloride complex 0.10y as catalyst components.

Polypropylene powder 224y was obtained with a polymerization time of 2 hours.

This polypropylene powder ■96.3%,
The intrinsic viscosity was 1.89 and the bulk specific gravity was 0.32. On the other hand, amorphous polypropylene 11y was obtained from the oral liquid, and the total amount of the polymer produced in this polymerization reaction was 92.0%, and the polymerization activity of the catalyst was 98k9/y-Tr・Hrl obtained amount was 1
It was 95 kg/y-Tl.

Comparative Examples 4 to 6 The results are shown when the addition of the ethyl benzoate/aluminum chloride complex used as the (C) component of the catalyst in the method of Example 4 is omitted, and when ethyl benzoate is used instead. Shown in 3.

Example 6 The activated titanium component prepared in Example 1 was used to carry out bulk polymerization of propylene.

Inner volume 6f (7) SUS-3S n- in autoclave
0.1 activated titanium component suspended in 30 ml heptane
0y1 0.2 mL of triethylaluminum and 0.10 g of ethyl benzoate/aluminum chloride complex were charged.

Next, after evacuating the nitrogen in the autoclave using a vacuum pump, 2.5 kg of propylene and 0.5 N1 of hydrogen were charged into the autoclave.

The contents of the autoclave were heated and the temperature was raised to 75°C after 5 minutes, and polymerization was carried out at 75°C for 3 hours. After cooling the autoclave, propylene was purged and the contents were taken out and dried under reduced pressure to obtain 985q of polypropylene powder. The total ■ of the obtained polypropylene powder is 93.3
%, intrinsic viscosity number 1.77, and bulk specific gravity 0.36 y/ml.

The polymerization activity of the catalyst in this polymerization reaction is 273k9/y-Ti
-Hr, and the amount obtained was 820k9/f-Ti.

Examples 7 to 10 Among the experiments in Example 6, propylene was bulk polymerized using various compounds in place of the ethyl benzoate/aluminum chloride complex added during polymerization. The results are shown in Table 4.

Example 11 Using the crusher used in Example 1, magnesium chloride 2
0y1 Ethyl benzoate/aluminum chloride complex 8.4y
1 Titanium tetrachloride 1.6f! was ground for 2 hours to obtain an activated titanium component with a titanium content of 1.5 wt%.

Polymerization was carried out in the same manner as in Example 6 except for using this activated titanium component.
A polypropylene 760y having an intrinsic viscosity of 2.01 was obtained.

The activity of the catalyst in this polymerization reaction is 169y/y-Ti-H
The amount of r obtained was 506k9/y-Ti.

Comparative Example 7 Polymerization was repeated using the same mole of benzoic acid 0.05y instead of the ethyl benzoate aluminum halide complex added during polymerization in the method of Example 11, resulting in a total volume of 88.0%. Polypropylene 403y having a specific gravity of 0.33y/ml and an intrinsic viscosity of 1.9 was obtained.

The activity of the catalyst in this polymerization reaction is 90y/y-Ti-Hr
The amount obtained was 286k9/y-Ti.

[Brief explanation of the drawing]

From the polymerization results of Examples 1 to 3 and Comparative Examples 1 to 3, the relationship between the amount obtained in the polymerization reaction and the total ■ is plotted on a chart with a horizontal logarithmic scale and a vertical regular scale, as shown in FIG.

Claims (1)

[Claims] 1. (A) A composition in which a titanium compound is supported on a magnesium compound (B) An organoaluminum compound (C) Polymerization of α-olefin in the presence of a catalyst consisting of an aluminum halide/organic acid ester complex A method for polymerizing α-olefins, characterized in that: