JPH0127087B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing olefin polymers using a catalyst that exhibits excellent catalytic activity and provides polymers with high stereoregularity. Conventionally, the so-called Ziegler-Natsuta catalyst, which is a combination of a transition metal compound from Group ~ of the Periodic Table of the Elements and an organometallic compound from Group ~, has been widely used for the polymerization of olefins. An example of this is a combination of titanium trichloride and an organoaluminum compound. In this polymerization method, amorphous polymers other than highly crystalline olefin polymers, which have high industrial utility value, are produced as by-products. This amorphous polymer not only has poor industrial utility value, but also has various undesirable adverse effects on physical properties when the olefin polymer is used as a film or other processed product. In order to suppress the amount of by-products of amorphous polymers, a method is known in which various electron-donating compounds are further supplied to the polymerization system in addition to the titanium trichloride and organoaluminum compound to polymerize olefins. However, although this method reduces the by-product rate of amorphous polymers, it has always also resulted in a reduction in catalytic activity. In addition, when used in combination with an electron-donating compound,
There was also the problem that transparency deteriorated when processed into a film. Also known is a method in which titanium trichloride is co-pulverized with various electron-donating compounds, and the thus obtained solid catalyst and organoaluminum compound are supplied to a polymerization system to polymerize olefins. However, this method also has the same problems as the method of supplying an electron-donating compound to the polymerization system, and also has the problem of producing fine powder or coarse particles because it involves a pulverization process. Since the particle size distribution of the produced olefin polymer is almost similar to the particle size distribution of the titanium trichloride solid catalyst, fine powder and coarse particles are not desirable in handling the polymer powder. In view of the drawbacks of the prior art, the present inventors
As a result of various studies, the above drawbacks were surprisingly overcome by using a solid catalyst produced by reacting titanium trichloride with a mixture of organometallic compounds and electron-donating compounds from Groups 1 to 3 of the periodic table. The present invention was based on this discovery. That is, the present invention combines A titanium trichloride composition with AlRnX _3-o (R is an alkyl group having 1 to 8 carbon atoms, X is a halogen, and n is a number satisfying 1≦n≦3) and an ester compound, or A solid catalyst produced by reacting with a mixture with at least one electron-donating compound selected from phosphite compounds, and B AlR′mX _3-n (R′ is an alkyl group having 1 to 8 carbon atoms, is a halogen, and m is a number satisfying 1≦m≦3.
This is a method for producing an olefin polymer, characterized by copolymerizing an olefin and another olefin having 2 to 8 carbon atoms. The method of the present invention provides the following superior effects compared to the prior art. (1) The by-product rate of amorphous polymers can be suppressed without reducing catalyst activity. (2) A film with good transparency can be obtained. (3) The amount of electron donating compound used can be small. (4) Fine particles and coarse particles do not increase. Component A) used in the present invention is a solid catalyst produced by reacting a titanium trichloride composition with a mixture of an organoaluminum compound and an electron donating compound. The titanium trichloride used here is obtained by reducing titanium tetrachloride with hydrogen, metals such as aluminum, magnesium, and titanium, and organometallic compounds such as organoaluminum compounds and organomagnesium compounds, and is obtained by heat treatment, pulverization, and complexation. Compositions containing titanium trichloride as a main component, such as those obtained by activation using methods such as oxidizing agent treatment and halogen compound treatment, and those obtained by simultaneously reducing and activating titanium tetrachloride. . A) General formula AlRnX _3-o used in the production of component
(R is an alkyl group having 1 to 8 carbon atoms, X is a halogen, and n is a number satisfying 1≦n≦3) Specifically, the organoaluminum compound represented by Examples include alkyl aluminum halides such as alkyl aluminum, diethylaluminium chloride, and diethylaluminium iodide. It may be the same as or different from the organoaluminum compound used as component B) in the present invention. Specifically, the ester compound selected as the electron donating compound is methyl acrylate, methyl methacrylate, methyl maleate, methyl itaconate, ethyl acrylate, methyl benzoate, ethyl benzoate, ethyl p-anisate, n-methyl butyrate, iso-methyl butyrate, γ-butyrolactone, γ
-Caprolactone, ε-caprolactone, etc. are exemplified. Specific examples of the phosphite compound include tri-n-butyl phosphite, triphenyl phosphite, and triethyl phosphite. One kind of these electron-donating compounds may be used, or two or more kinds thereof may be used. If the titanium trichloride composition is reacted only with the electron-donating compound, the catalyst activity will be significantly reduced, the rate of amorphous polymer by-products will not be suppressed, and the haze of the film will worsen, making it impossible to achieve the effects of the present invention. I can't. Although the mixing ratio of the organoaluminum compound and the electron-donating compound is arbitrary, it is better not to use the electron-donating compound in large excess with respect to the organoaluminum compound. A mixture in which the organoaluminum compound is present in about 0.2 to 50 equivalents relative to the electron donating atom or atomic group in the electron donating compound is preferable, and more preferably 0.5 to 10 times. A diluent may not be present in the mixture of the organoaluminum compound and the electron donating compound, but
Since heat generation is intense during mixing, it is desirable to carry out the mixing in the presence of an inert diluent such as a hydrocarbon. In this case, the concentration of the organoaluminum compound is preferably 0.01 mol/or more, more preferably 0.1 mol/or more. The amount of the mixture to be used for the titanium trichloride composition depends on the manufacturing method and properties of the titanium trichloride composition, the type and properties of the organometallic compound, the type and properties of the electron-donating compound, and the production of component A). Although it varies depending on the reaction conditions etc., titanium trichloride composition 1 is usually used.
Electron donating compound in the mixture per mole is 0.01~
0.5 mol, preferably 0.05-0.2 mol. The reaction temperature and reaction time of the titanium trichloride composition and the mixture can be arbitrarily selected depending on the properties of the reactants, but the reaction temperature is usually 0 to 100°C, preferably 20 to 80°C, The reaction time is usually more than 1 minute,
Preferably it is 10 minutes or more. The component A) thus obtained can be separated from the unreacted solution of the mixture, washed with an inert solvent, and used in a slurry or dry state, but it is not separated from the unreacted solution of the mixture. It can also be used as is. In the industrial production of polyolefin, it is common to mix a titanium trichloride composition into a slurry of an inert solvent and feed this slurry to a polymerization system, but in the present invention, a predetermined amount of the organic An embodiment may be adopted in which a metal compound and an electron-donating compound are added. Specifically, component B) used in the present invention includes trialkylaluminum such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, dialkylaluminum monohalide such as diethylaluminum chloride, diethylaluminium bromide, and diethylaluminium iodide, and ethyl Examples include alkyl aluminum sesquihalides such as aluminum sesquichloride, and alkyl aluminum dihalides such as ethyl aluminum dichloride. Among these, diethylaluminum chloride is most preferred. The ratio of component A) and component B) may be any ratio generally used for polymerization of olefins, but usually the titanium trichloride composition in component A and B)
The molar ratio of the components is about 1:0.1-100. In the present invention, the electron-donating compound is used during the production of component A);
This does not preclude supplying the electron-donating compound to the polymerization system together with the other components. Polymerization can be carried out over a temperature range of -30 to 200°C, but temperatures below 0°C result in a decrease in the polymerization rate, and temperatures above 100°C make it impossible to obtain highly stereoregular polymers. For these reasons, it is usually preferable to carry out the reaction at a temperature in the range of 0 to 100°C. Although there are no particular restrictions on the polymerization pressure, a pressure of about 1 to 100 atm is desirable from the viewpoint of industrial and economical considerations. The polymerization method can be continuous or batchwise. Next, the olefin to which the present invention can be applied has 2 carbon atoms.
~10 things, specific examples are ethylene,
Examples include propylene, butene-1, pentene-1,4-methylpentene-1, etc., but the present invention is not limited to the above compounds. The polymerization according to the present invention can be either homopolymerization or copolymerization. During copolymerization, a copolymer can be obtained by bringing two or more types of olefins into contact in a mixed state. Further, heteroblock copolymerization in which polymerization is carried out in two or more stages can also be easily carried out. Polymerization can be carried out by slurry polymerization or solution polymerization in an inert hydrocarbon solvent such as butane, pentene, hexane, heptane, or octane or by using the liquid phase monomer itself as a medium, or by gas phase polymerization carried out in the absence of a liquid phase medium. Both are possible. The method of the present invention will be explained below using Examples, but the present invention is not limited to these Examples in any way. In addition, the by-product rate of the amorphous polymer in the following examples was evaluated by the content of cold xylene soluble portion (abbreviated as CXS%) measured by the method shown below. CXS%: After dissolving the polymer in boiling xylene, cooling it to 20℃, separating the precipitated polymer, and then evaporating the xylene from the liquid and drying it, the remaining amorphous polymer is compared to the sample polymer. The weight percentage is expressed as CXS%. The higher the CXS%, the higher the by-product rate of amorphous polymer. Example 1 (1) Preparation of catalyst 1 Preparation method (preparation of reduction product) After purging a 200-liter reaction vessel with argon, 40 percent of dry hexane and 10 percent of titanium tetrachloride were added.
This solution was kept at -5°C, and a solution consisting of 30% of dry hexane and 23.2% of ethylaluminum sesquichloride was added dropwise under such conditions that the temperature of the reaction system was kept below -30°C. Stirring was then continued at the same temperature for 2 hours. After the reaction, the resulting reduced product was allowed to stand still and was subjected to solid-liquid separation at 0°C, and washed twice with 40 kg of hexane to obtain 16 kg of reduced product. 2 Preparation method The reduction product obtained by the preparation method is slurried in n-decalin, and the slurry concentration is 0.2 g/cc.
It was heat treated at 140°C for 2 hours. After the reaction, the supernatant liquid was extracted and washed twice with 40% hexane to obtain titanium trichloride composition A. 3 Preparation method 11 kg of titanium trichloride composition A prepared according to the preparation method was slurried in ₅₅ toluene, and iodine and Titanium trichloride composition B was obtained by adding isoamyl ether and reacting at 80° C. for 1 hour. 4 Preparation method In a 100 ml flask purged with argon, 50 ml of purified n-heptane, 163 mg of diethylaluminium chloride, 136 mg of methyl methacrylate.
After stirring well for 30 minutes, 2.1g of titanium trichloride composition B prepared according to the preparation method.
and stirred for 30 minutes while keeping the flask at 70°C. The molar ratio of titanium trichloride:diethylaluminum chloride:methyl methacrylate is 1:0.1:0.1. After the reaction, the supernatant liquid was extracted and washed three times with 50 ml of n-heptane to obtain solid catalyst C. (2) Polymerization of propylene A stirred stainless steel autoclave with an internal volume of 5 was purged with nitrogen, and 3.0 g of diethyl aluminum chloride and 50 mg of the above solid catalyst C were charged.
Hydrogen corresponding to a partial pressure of Kg/cm ² was added. Then, 1.4 kg of liquid propylene was pressurized into the autoclave, and the autoclave was kept at 65°C to continue polymerization for 2 hours. After the polymerization was completed, unreacted monomers were purged, and 100 c.c. of methanol was added to decompose the catalyst. The produced polypropylene was separated using a Buchner tube and dried under reduced pressure at 60°C to obtain 256 g of powdered polypropylene. Rp expressed as the amount of polymer produced per 1 hour of polymerization time per 1 g of the titanium trichloride solid catalyst was 2560. Also, CXS%
was 1.8. 0.2% by weight of 2,6-ditertiarybutyl-p-cresol was added to this powdered polypropylene and granulated, and then formed into a 30μ film using a T-die extruder. The film had an excellent haze of 1.8%. Comparative Example 1 The same procedure as in Example 1 was carried out except that titanium trichloride composition B before being reacted with the mixture of dimethylaluminum chloride and methyl methacrylate was used instead of solid catalyst C used in Example 1. The results are shown in Table 1. It can be seen that in comparison with Comparative Example 1, in Example 1, the by-product rate CXS% of the amorphous polymer was significantly suppressed without decreasing the polymerization activity Rp.
Also, the haze of the film has not changed. Comparative Examples 2 and 3 Diethylaluminium, titanium trichloride composition B
In addition to 3.2 mg of methyl methacrylate
(0.1 mole per mole of solid catalyst B) or 97mg
(3 moles per mole of solid catalyst B) The same procedure as in Comparative Example 1 was carried out except that the autoclave was charged. The results are shown in Table 1. Comparing these comparative examples with Example 1, it was found that feeding the same methyl methacrylate as in Example 1 to the polymerization system had little effect, and that in order to obtain the same CXS% as in Example 1, it was necessary to supply 30 times as much CXS%. amount of methyl methacrylate must be used and
It can be seen that Rp decreases and film haze worsens. Comparative Example 4 Example 1 (1) except that titanium trichloride composition B was reacted with a heptane solution of 136 mg of methyl methacrylate instead of reacting with the mixture of diethylaluminium chloride and methyl methacrylate in (1) of Example 1. Component A) was prepared in the same manner as in Example 1, and propylene polymerization was carried out in the same manner as in Example 1. The results are shown in Table 1. Comparing this result with Example 1, only a significant decrease in Rp was observed, but CXS% was not suppressed but rather increased.
It can also be seen that the haze of the film has deteriorated significantly.

[Table] Examples 2 to 6 and Comparative Examples 5 to 6 (1) Preparation of catalyst 1 Preparation method (preparation of β-type titanium trichloride) After purging the reactor of 200 with argon, 40 of dry hexane, 10 of titanium tetrachloride was added and the solution was kept at -5°C. Then, a solution consisting of 30% of dry hexane and 11.6% of diethylaluminum chloride was added dropwise under such conditions that the temperature of the reaction system was maintained at -3°C or lower. After the dropwise addition was completed, stirring was continued for another 30 minutes, then the temperature was raised to 70°C, and stirring was continued for an additional hour. The mixture was then allowed to stand to separate the β-type titanium trichloride into solid and liquid, and was further washed three times with 40 kg of hexane to obtain 15 kg of a reduced product. The titanium trichloride contains 4.60% by weight Al. 2 Preparation method (Preparation of Lewis base treated solid) The β-type titanium trichloride obtained by the above preparation method was
40 in dry hexane, then diisoamyl ether was added in a molar ratio of 1.2 to β-type titanium trichloride, and the mixture was stirred at 40°C for 1 hour. After the reaction was completed, the supernatant liquid was extracted and
It was washed three times with hexane and dried. 3. Preparation method 10 kg of the Lewis base-treated solid prepared according to the above-mentioned preparation method was added to a solution consisting of 30% dry heptane and 20% titanium tetrachloride, and treated at 70°C for 2 hours. After the reaction, the supernatant liquid was extracted, washed three times with 30 ml of hexane, and dried to obtain titanium trichloride composition D. 4. Preparation method Into a 100 ml flask purged with argon, 50 ml of purified n-heptane and the organoaluminum compounds and electron-donating compounds listed in Table 2 were charged.
After stirring well for a minute, 2.0 g of titanium trichloride composition D listed in Table 2 was charged, and the flask was heated to 70°C.
and stirred for 30 minutes. After the reaction, the supernatant liquid was extracted and washed three times with 50 ml of heptane to obtain a solid catalyst. (2) Polymerization of propylene Example 1 except for using the solid catalyst shown in Table 2
I did the same thing. The results are shown in Table 2. Reference Example 1 and Reference Comparative Example 1 Example 2 except that titanium trichloride TAC-131 manufactured by Toyo Stouffer Co., Ltd. was used instead of solid catalyst C.
-6 and Comparative Examples 5-6. The results are shown in Table 2.

[Brief explanation of drawings]

FIG. 1 is a flowchart to aid in understanding the present invention. This flowchart shows a representative example of an embodiment of the present invention.

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Claims (1)

[Scope of Claims] 1 A titanium trichloride composition is AlRnX _3-o (R is an alkyl group having 1 to 8 carbon atoms, X is a halogen,
A solid catalyst produced by reacting a mixture of (n is a number of 1≦n≦3) with at least one electron-donating compound selected from ester compounds or phosphite compounds;
and B AlR′mX _3-n (R′ is an alkyl group having 1 to 8 carbon atoms, Homopolymerization of α-olefin having 3 to 8 carbon atoms or α-olefin having 3 to 8 carbon atoms
A method for producing an olefin polymer, comprising copolymerizing an olefin and another olefin having 2 to 8 carbon atoms.