JPS5943482B2 - Polymerization method of α-olefin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the improvement of catalysts for the polymerization of olefins, and more specifically, the present invention relates to improvements in catalysts for the polymerization of olefins, and more specifically, they exhibit sufficiently high activity and high stereoregularity in the stereoregular polymerization of α-olefins such as propylene and 1-butene. This invention relates to a method for preparing a catalyst for producing regular polymers.

Propylene, 1-butene, 4-methyl-1-pentene,
Ziegler catalysts are well known as catalysts for the stereoregular polymerization of a-olefins such as styrene, and typical catalysts include titanium halides and organoaluminum compounds such as triethylaluminum or diethylaluminum halide. It is.

Currently, the most widely used titanium halide is Ξ titanium chloride composition, and its production method is as follows:
(a) After reducing titanium tetrachloride with metal aluminum,
A method of dry grinding into a fine powder. (b) A method in which titanium tetrachloride is reduced with hydrogen or metallic titanium and then pulverized; and (c) a method in which titanium tetrachloride is reduced with an organoaluminum compound to obtain a Ξ titanium chloride composition. However, even when α-olefins are polymerized using a combination catalyst of the Ξ titanium chloride composition and an organoaluminum compound produced in this way, the activity toward α-olefins is insufficient, and moreover, a large amount of amorphous Since a non-crystalline polymer is produced as a by-product, the process of producing a stereoregular polymer from an α-olefin such as propylene usually includes an amorphous polymer separation step.

Conventionally, in the production of polyolefins, increasing the amount of polymer produced per catalyst unit and minimizing the production of amorphous polymer by-products has been one of the extremely important industrial issues.

That is, as the amount of polymer produced per catalyst unit increases, the amount of catalyst required for polymerization decreases, so the amount of catalyst remaining in the polymer also decreases, reducing the need for deashing. Moreover, the amorphous polymer produced as a by-product has low added value and has few uses, and only unnecessarily complicates the production and separation process. An invention described in Japanese Patent Publication No. 40-20169 is a proposal for solving the above-mentioned problems in an improved pulverization method for a titanium trichloride component, which is a component of a catalyst.

According to this improved method, the activity of the catalyst is improved by the pulverization treatment, but it is still insufficient, and the stereoregularity of the resulting polymer tends to decrease. Since such simple pulverization alone does not produce a sufficient improvement effect, the applicant has proposed that the raw material Ξtitanium chloride composition be treated in the presence of various electron donors, etc. A number of inventions have already been proposed which consist of a combination of extraction and washing of a ground trisalt titanium composition with an inert solvent or an inert solvent containing an electron donor. The present invention provides a catalyst capable of producing polymers with stereoregularity equivalent to or higher than those of the polymers according to the previously proposed inventions at higher yields.

That is, the present invention (a) pulverizes a raw material titanium trichloride composition in the presence of an organoaluminum compound to a level that makes it impossible to identify an X-ray diffraction pattern based on α-type or γ-type crystals of the inherent titanium trichloride component. Then, after contacting with titanium tetrahalide, extraction and washing is performed with an inert solvent containing an electron donor to obtain a modified titanium trichloride composition and (5) a catalyst obtained from an organoaluminum compound. The present invention relates to a process for homopolymerizing or copolymerizing α-olefins containing 3 or more carbon atoms with ethylene or other α-olefins. The feature of the method of the present invention is that when the raw material titanium trichloride composition is pulverized, an organoaluminum compound is added and treated, and then, after contacting with titanium tetrahalide,
The catalytic activity of the titanium trichloride composition and the stereoregularity of the resulting polymer can be greatly improved by a simple operation of extraction and washing with an inert solvent containing an electron donor.

The modified titanium trichloride composition used in the present invention is prepared by combining the following steps.

(1) A raw titanium trichloride composition is pulverized in the presence of an organoaluminum compound, and then the pulverized product is brought into contact with titanium tetrahalide. (2) Titanium trichloride composition brought into contact with titanium tetrahalide. These steps of extracting and washing the product with an inert solvent containing an electron donor cannot alone provide the high performance catalyst required by the present invention.

However, the present invention, which consists of a combination of the above (1) and (2), exhibits excellent effects that could never be expected from both. Further, in order to achieve the object of the present invention, it is necessary to perform the process of step (2) after the above-mentioned step (1). Known methods for treatment with titanium tetrahalides include the following.

(a) Pulverizing the raw material titanium trichloride composition in the presence of a small amount of titanium tetrachloride (described in Japanese Patent Publication No. 39-24270) (b) Inert carbonization of a material that partially overlaps with the above treated material Extraction and washing with a hydrogen solvent (see Japanese Patent Publication No. 4844674) Among these methods, in (a) both the polymerization activity and the stereoregularity of the resulting polymer are insufficient, and in (b) the polymerization activity is insufficient. be.

According to the method of the present invention, effects in both the activity of the catalyst and the stereoregularity of the produced polymer can be achieved that exceed those of the prior inventions.

In general, in Ziegler-Natsuta catalysts, when the activity towards α-olefins is increased, the stereoregularity of the resulting polymer tends to decrease significantly, but the present invention improves this tendency of conventional methods, It achieves both high polymerization activity and high stereoregularity.

Each component of the present invention will be explained in detail below.

In the present invention, what is referred to as a raw material titanium trichloride composition is a compound whose main component is titanium trichloride obtained by reducing titanium tetrachloride with, for example, hydrogen, metallic titanium, metallic aluminum, silicon, or antimony. Alternatively, it may be a eutectic with a metal halide used for reduction such as silicon chloride. Note that small amounts of titanium tetrachloride and titanium dichloride may also be included. In the present invention, the organoaluminum compound to be present during the pulverization of the titanium trichloride composition has the general formula RnAlCl3-.

(where R is an alkyl group, n is a number of O≦n≦3, preferably 1≦n≦2), and differs from each other in R and/or n. A combination of two or more types of organoaluminum compounds may also be used. These are commonly known as alkylaluminum dichlorides, alkylaluminum sesquichlorides, and combinations thereof, such as ethylaluminum dichloride, propylaluminum dichloride, 1-butylaluminum dichloride, ethylaluminum sesquichloride, n
-Butylaluminum sesquichloride, combinations of ethylaluminum dichloride and ethylaluminum sesquichloride in various proportions, etc., but preferred are alkyl groups containing 1 to 4 carbon atoms such as ethylaluminum dichloride and butylaluminum dichloride. It is an alkyl aluminum dichloride having one. The amount of organoaluminum compound used per 1 m01 of the raw material titanium trichloride composition (based on trivalent titanium atoms contained) is usually 0.005 to 0.5 m011, preferably 0.05 to 0.5 m0, based on aluminum atoms.
1, particularly preferably 0.1 to 0.3 m01.

In the pulverization process, the raw titanium trichloride composition and the organoaluminum compound are charged into a pulverizer such as a rotating pole mill, a vibrating pole mill, or an impact mill, or a mixer equipped with powder and sand capacity, and the α of the inherent titanium trichloride component is The process is continued until the X-ray diffraction pattern based on the type or γ-type crystal disappears and can no longer be identified.

The temperature during the pulverization process is preferably about room temperature and 50°C or less,
If severe heat generation occurs, it is better to cool it down. When the obtained pulverized titanium trichloride composition is further contacted with titanium tetrahalide, the amount of titanium tetrahalide used is usually 0.05 to 1 atom of aluminum in the organoaluminum compound used during pulverization. 2.0m
01, preferably in the range of 0.8 to 1.5m01. The contact with titanium tetrahalide can be carried out by any known contacting means, for example, the contact may be carried out under pulverizing conditions using the above-mentioned pulverizing means,
The ground titanium trichloride composition may be immersed in liquid titanium tetrahalide or its solution in an inert solvent. The contact temperature for both is preferably from around room temperature to about 80°C, for example. The contact time is usually 0.5 to 5 in the case of grinding contact.
In the case of immersion contact, 0.5 to 10 hours are usually sufficient. In an inert solvent or an electron donor-containing inert solvent for extracting and cleaning a tetrahalogenated titanium-treated product of a pulverized titanium trichloride composition, an inert solvent is an organic solvent that is inert to a normal Ziegler catalyst. A solvent selected from, for example, hydrocarbons and halogenated derivatives thereof. These include, for example, saturated aliphatic hydrocarbons such as pentane, hexane, heptane, isooctane, kerosene, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, haloaromatic hydrocarbons such as chlorobenzene, brombenzene, trichloroethylene, etc. However, aromatic hydrocarbons such as toluene are preferred. The amount of inert solvent used is 1 m0 of the titanium trichloride component in the titanium tetrahalide product of the pulverized product to be extracted.
It is usual to choose a ratio of 1 to 100 m01, but this is not critical. The extraction and washing can be carried out at a temperature ranging from room temperature or below to the boiling point of the extraction solvent, but it is preferably carried out at a temperature ranging from room temperature to 7'C. Various methods such as decanting, continuous countercurrent contact, and contact using a soxle type extractor can be used for extraction and washing. However, whichever extraction and cleaning method is adopted, it is important to separate the extract after extraction and cleaning from the titanium trichloride composition to be extracted as much as possible. The time required for extraction and cleaning is approximately several minutes to several days. Even if extraction and washing is performed using an inert solvent alone, no effect superior to the prior art can be obtained. Examples of electron donors used for extraction and cleaning include the following.

(1) Dialkyl ether, diaryl ether, alkylaryl ether such as dimethyl ether, diethyl ether, ethyl-1-butyl ether, di-n-
Butyl ether, diphenyl ether, phenyl p-
Tolyl ether, anisole, phenatele, i-butyl phenyl ether, p-methylanisole, p-chloroanisole; (2) dialkyl ketone, diaryl ketone, alkylaryl ketone, cycloalkanone,
β-diketones such as acetone, methyl ethyl ketone, methyl-1-butyl ketone, di-1-butyl ketone,
Benzophenone, p-methylbenzophenone, P, p'
- ditrilophenone, acetophenone, propiophenone, butylophenone, methyl p-tolyl ketone, cyclohexanone, acetylacetone; (3) aliphatic carboxylic acid alkyl esters, their halogen-substituted products such as methyl formate, n-butyl formate, ethyl acetate, acetic acid 1 -propyl, ethyl propionate, 1-amyl butyrate, ethyl laurate, ethyl monochloroacetate, 2-chloroethyl acetate; (4) Tertiary amines, nitrogen-containing heterocyclic compounds, halogen-substituted products thereof such as triethylamine, tri-n
-Butylamine, 1J-n-hexylamine, triphenylamine, diphenylethylamine, N,N-dimethylaniline, pyridine, α-picoline, 2-chloropyridine, quinoline, isoquinoline; (5) Other nitrogen-containing organic compounds (6) Organic sulfur compounds such as diethylthioether, thioanisole, carbon disulfide; (7) Organic triphosphites and triphosphines such as triphenyl phosphide; (8) Organosilicon compounds such as methylpolysiloxane, Organic polysiloxanes such as methylphenylpolysiloxane, dimethylpolysiloxane, and diphenylpolysiloxane, trimethylacetoxysilane, triethylacetoxysilane, triethylethoxysilane, p-methoxyphenyltrimethylsilane, N-methylhexamethylsilazane, and the like. Among these electron donors, preferred are dialkyl ethers such as di-n-ethyl ether shown in (1), diaryl ethers such as diphenyl ether, alkylaryl ethers such as anisole, and tertiary ethers such as triethylamine. These are amines and organic polysiloxanes.

The amount of electron donor added to prepare the electron donor-containing inert solvent used for extraction and cleaning is 1 m01 of the titanium trichloride component inherent in the titanium trichloride composition to be extracted treated with titanium tetrahalide. 0.005 to 2m01
The preferred addition amount is 0.1 to 1m011 amine for the above-mentioned ethers, ketones, and esters, and 0.01 to 0.1m011 for nitrogen-containing heterocyclic compounds and other nitrogen compounds. 3 m01, 0.01 to 0.3 m01 for organic sulfur compounds, 0.01 to 0.3 m01 for organic triphosphites and triphosphine.
0.01 to 0.6 m01, and 0.1 to 0.5 m01 for organosilicon compounds.

It is important to separate and collect the extracted and washed titanium trichloride composition from the extract.

Separation is particularly important when storing the composition. When storing the separated composition, it may be suspended in a fresh inert solvent, or it may be dried under normal pressure or reduced pressure and left in a solid state in an inert gas such as nitrogen. good. The inert solvent used for preservation may be the same type as that used for extraction and washing. The modified titanium trichloride composition obtained by the preparation method of the present invention, when combined with an organometallic compound, particularly an organoaluminum compound, exhibits usefulness as a highly active, highly stereoregular polymerization catalyst for α-olefins.

The organoaluminum compound used here is known as a catalyst component for α-olefin polymerization, and preferred examples include trialkylaluminum such as triethylaluminum and tri-i-butylaluminum, and dialkylaluminum such as diethylaluminum chloride. halogenides, dialkyl aluminum alkoxides such as diethylaluminum ethoxide, alkyl aluminum alkoxy halogenides such as ethyl aluminum ethoxy chloride, alkyl aluminum dihalides such as ethyl aluminum dichloride, and general formula M2M' such as potassium titanium fluoride. F6 (where M is an alkali metal such as Na or K, Mt, Ti, .Sn, .Zr
、． Reaction products with complex metal fluorides represented by (representing a tetravalent metal such as Si) can be mentioned. Organozinc compounds can also be used as other organometallic compounds.
The catalyst of the present invention can be used in the homopolymerization of α-olefins containing three or more carbon atoms, such as propylene, 1-butene, 4-methyl-1-benzene, and styrene, or in the copolymerization of these with ethylene or other α-olefins. Demonstrates excellent effects.

These α-olefin polymerizations or copolymerizations can be carried out in an inert solvent, in an α-olefin monomer solvent kept in a liquid state, or in a gas phase. Moreover, it can be carried out either batchwise or continuously. In order to control the molecular weight of the produced polymer, it is practical to include hydrogen in the polymerization system. The temperature when polymerizing in an inert solvent such as hexane, heptane, isooctane, or kerosene varies depending on the solvent, but is usually 5.
0 to 80'C, pressure is normal pressure to 40Ky/(V7
Just choose l2.

In addition, the catalyst concentration in the polymerization system is usually 0.1 to 10 mm01/t1 based on titanium atoms, and usually 0 based on aluminum atoms.
．． Select from 4 to 50mm01/t. Example 1 Preparation of modified titanium trichloride composition> (1) Titanium tetrachloride 17009 and aluminum powder 279 were heated at 200°C in the presence of aluminum chloride 13.39 in an autoclave made of stainless steel (SUS-32).
The reaction was carried out for 20 hours.

Unreacted titanium tetrachloride was distilled off from the product at atmospheric pressure, and the remaining solid was distilled off at 200°C under a reduced pressure of 0.2 muHg.
The mixture was heated for a period of time to remove trace amounts of residual titanium tetrachloride and free aluminum chloride to obtain a reddish-purple raw material titanium trichloride composition 5759. (2) In nitrogen, raw material titanium trichloride composition 609, ethylaluminum dichloride 8.09 and 850 stainless steel (SUS-32) balls with a diameter of 10 mm were mixed into stainless steel (SUS-32) with an internal volume of 800a.
-32), the cylinder was attached to a vibrating device, and vibration milling was carried out at room temperature and with a vibration force of 400 Kf for 5 hours.

Next, 179 titanium tetrachloride was added to the pulverized material in the container under nitrogen, and the pulverization treatment was performed again under the same conditions for 5 hours. (3
) 159 ml of the pulverized product, 100 ml of toluene, and 4.1 ml of anisole were charged into a four-necked glass reactor with an internal volume of 300 W11 equipped with a magnetic stirrer, and extraction was carried out under stirring at 70° C. for 2 hours.

After the stirring was stopped, the mixture was allowed to stand for 30 minutes, and the supernatant liquid was taken out and the same amount of fresh toluene was added. After repeating this operation twice, the slurry is filtered through a glass filter under nitrogen. The solid was dried under reduced pressure at room temperature for 6 hours to obtain modified titanium trichloride composition 119. Polymerization of propylene> 1 ton of refined kerosene is charged into an autoclave with an internal volume of 2 t equipped with a stirrer, a thermometer, and a propylene inlet pipe, and nitrogen gas is passed through the refined kerosene for 1 hour while stirring to replace the refined kerosene with nitrogen, resulting in modified trichloride. 0.2g (1n1n101) of titanium composition and 5mm01 of diethylaluminium chloride were added in this order under a nitrogen atmosphere, and after raising the temperature to 70°C, 200ml of hydrogen was added.
1 was added.

Partial pressure of propylene is 7K'/C! ! Polymerization was carried out for 2 hours with introduction in the LG. After the polymerization was completed, the propylene gas was depressurized, and methanol 200111 was added to the reactor at a lower temperature to decompose the catalyst. After finishing the polymer slurry and washing the powder solid on the plate several times with methanol, 70-50 mm1
Drying was carried out for 2 days in g, solid polypropylene 2
I got 429. Its stereoregularity index (abbreviated as p-11,
Weight % of residue extracted from powdered polymer with boiling n-heptane
) was 97.2%. Polymer 39 dissolved in the liquid
The total stereoregularity index (abbreviated as t-11, the weight percent of the total polymer extracted with boiling n-heptane) is 95.8%, and the specific activity of the catalyst is 17.59/Ti- M
It was mOl-Hr-Atm. Comparative Example 1 In the pulverization operation of Example 1, the raw titanium trichloride composition was pulverized in the absence of ethylaluminum dichloride and titanium tetrachloride, and 0.29% of the obtained pulverized material was extracted and washed without extraction and washing. Polymerization of propylene was carried out in the same manner as in Example 1.

The total yield of polymer was 74.29, t-11 was 91.0%,
The specific activity of the catalyst is 5.3f! /Ti-MmOl・Hr・A
It was tm. Comparative Example 2 The raw titanium trichloride composition of Example 1 was milled without the presence of ethylaluminum dichloride and titanium tetrachloride, and extraction and cleaning was carried out in the same manner as the extraction and cleaning of Example 1. Polymerization of propylene was carried out in the same manner as in Example 1 using titanium chloride composition 0.29.

The total yield of polymer was 1199, t-11 was 95.0 (fl
), the specific activity of the catalyst is 8.59/Ti-MmOl-Hr-
It was hot at ATM. Comparative Example 3 A pulverized titanium trichloride composition obtained by pulverizing a raw titanium trichloride composition in the presence of ethylaluminum dichloride but without adding titanium tetrachloride in the same manner as in Example 1 was extracted and washed. Polymerization of propylene was carried out in the same manner as in Example 1 using 0.29% of the amount without adding.

The total yield of polymer was 42.69, t-11 was 87.2%,
The specific activity of the catalyst is 3.0g/Ti-MmOl-Hr-At
It was m. From the above comparative examples, the following can be seen. (1) If an organoaluminum compound is present during pulverization of the raw material titanium trichloride composition, both the activity of the resulting catalyst and the stereoregularity of the resulting polymer are rather reduced. (2)
Even if an organoaluminum compound or titanium tetrachloride is not present when the raw material titanium trichloride composition is pulverized, the activity of the catalyst can be greatly improved if extraction and cleaning are performed.

Preparation of modified titanium trichloride compositions in Examples 2 to 4 and Comparative Examples 4 to 6> (1) In Example 1, except that the amount of ethylaluminum dichloride used during pulverization was changed to the proportions shown in Table 1. It was pulverized in the same manner as in Example 1.

(2) The obtained pulverized titanium trichloride composition 159 was mixed with hot torunin 10 containing 4.1 ml of anisole in the same manner as in Example 1.
After extraction and washing with 0ml, the solid portion was collected and dried to obtain a modified titanium trichloride composition. <Polymerization> Modified titanium trichloride composition obtained by the above preparation procedure 0
．． Table 1 shows the results of propylene polymerization using No. 29 in the same manner as in Example 1.

In addition, as a comparative example, the results are also shown when a pulverized product was used in which titanium tetrachloride was not added during pulverization and extraction and washing was not performed.

Examples 5 to 7 <Preparation of modified titanium trichloride composition> (1) In Example 1, various organoaluminum compounds listed in Table 2 were used instead of the ethylaluminum dichloride used during pulverization to form a raw material titanium trichloride composition. The pulverization treatment was carried out in the same manner as in the example except that the titanium trichloride component was used at a ratio of 0.15 m0I to 1 m01 of the endogenous titanium trichloride component.

(2) The pulverized titanium trichloride composition 159 was mixed with hot toluene 10011 containing 4.1 ml of anisole in the same manner as in Example 1.
A modified titanium trichloride composition was obtained by extraction and washing using No. 1.

Polymerization> Table 2 shows the results of polymerization of propylene in the same manner as in Example 1 using the modified titanium trichloride composition 0.29%.

Examples 8 to 14 and Comparative Example 7 Preparation of modified titanium trichloride composition> (1) Same as Example 1 except that 8.09% of diethylaluminum chloride was used instead of ethylaluminum dichloride in Example 1. A pulverized product was obtained.

(2) Inherent titanium trichloride component 1 in the pulverized product 159
To m01, 100 ml of toluene containing various electron donors in the amounts listed in Table 3 was added, and the mixture was heated at 70°C in the same manner as in Example 1.
Time extraction and cleaning was performed to obtain a modified titanium trichloride composition.

In addition, the titanium trichloride composition used in Comparative Example 7i did not use titanium tetrachloride during pulverization, and the pulverized product was extracted only with toluene. <Polymerization> Table 3 shows the results of polymerization of propylene in the same manner as in Example 1 using the modified titanium trichloride composition or the toluene-extracted titanium trichloride composition 0.29%.

Examples 15 to 18 Preparation of modified titanium trichloride composition> When performing extraction and cleaning (operation (3)) of the pulverized titanium trichloride composition obtained in operation 2) of Example 1, an inert solvent was used. Various organic solvents listed in Table 4 were used.

Polymerization> Using the obtained modified titanium trichloride composition, propylene was polymerized in the same manner as in Example 1. Table 4 shows the results.

Claims (1)

[Claims] 1 (a) The raw material titanium trichloride composition is treated in the presence of organoaluminum to form the α-type or γ-type of the inherent titanium trichloride component.
After pulverizing to a level that makes it impossible to identify the X-ray diffraction pattern based on the type crystal, and then contacting titanium tetrahalide,
An α-olefin containing 3 or more carbon atoms in the presence of a catalyst obtained from a modified titanium trichloride composition derived by further extracting and washing with an electron donor-containing inert solvent and (b) an organoaluminum compound. A method of homopolymerizing or copolymerizing with ethylene or other α-olefins.