JPS612706A - Polymerization of propylene - Google Patents

Abstract

PURPOSE:To produce polypropylene in high yield, by polymerizing propylene containing dissolved organo-Al compound, in the presence of a catalyst composed of the organo-Al compound and a Ti halide supported on a carrier containing a Mg halide. CONSTITUTION:A magnesium halide such as magnesium chloride and a titanium halide such as titanium trichloride are co-crushed to obtain a carrier, and is used in combination with an organo-aluminum compound such as triethylaluminum as a catalyst. An organo-aluminum compound such as triethylaluminum is dissolved in propylene having a purity of 95% at a concentration of preferably 1-2,500ppm, and the propylene is polymerized by vapor-phase polymerization or bulk polymerization to obtain the objective polypropylene.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a propylene polymerization method, and more specifically, a bulk polymerization method using propylene itself as a medium using a supported transition metal catalyst with a high yield per solid catalyst; This invention relates to an improved method for polymerizing propylene using a gas phase polymerization method.

Prior Art A method of polymerizing propylene using a supported transition metal catalyst in which titanium halide is supported on a carrier containing magnesium halide and a catalyst consisting of organoaluminum is disclosed in Japanese Patent Publication No. 3-9-1983. Since it was proposed in No. 12105, many improved methods have been proposed, and the yield per supported transition metal catalyst has reached an extremely high level. On the other hand, bulk polymerization methods or gas phase polymerization methods using propylene itself as a medium have been known for a long time (l!
! (F Publication No. 32-10596, Japanese Patent Publication No. 37-3291, Japanese Patent Publication No. 44-16017) It is known that since propylene itself is used as a medium, the monomer concentration during polymerization is high and polypropylene can be obtained at a high yield per catalyst. ing.

Problems to be Solved by the Invention By combining the above-mentioned high-yield catalyst with a polymerization method using propylene itself as a medium, it is expected that polypropylene can be produced at a high yield per catalyst. As the amount of catalyst used is reduced, the catalytic activity decreases due to the presence of extremely small amounts of catalyst activity inhibitors in propylene, which did not pose a problem in the past. There was a problem in that even if the produced propylene was used, the catalyst activity fluctuated, making it difficult to control the polypropylene production process.

Means for Solving the Problems The present inventors have made extensive studies on methods for solving the above problems, and have developed a supported transition metal catalyst obtained by supporting titanium halide on a support containing at least magnesium halide, and an organic In a method of polymerizing propylene using a catalyst made of aluminum by bulk polymerization or gas phase polymerization using propylene itself as a medium, polymerization using propylene in which at least a part of organoaluminum is dissolved. The present invention was completed based on the discovery that propylene can be polymerized in high yield per catalyst by doing this.

In the present invention, the supported transition metal catalyst obtained by supporting titanium halide on a carrier containing at least magnesium halide is magnesium halide, preferably magnesium chloride, titanium halide, preferably titanium trichloride. , a method of co-pulverizing with titanium tetrachloride, or a method of contacting magnesium halide with liquid titanium halide, in which case a method of using magnesium halide treated with various organic compounds (preferably oxygen-containing compounds). Alternatively, magnesium halide is dissolved in a solvent containing organomagnesium, alcohol, etc. and treated with a metal halide to produce a carrier containing magnesium halide, and then titanium halide is added to the carrier. A number of methods are already known, including supported methods and methods treated with various oxygen-containing organic compounds, but the most effective method of the present invention is
This is a catalyst that provides 10 kg or more of polypropylene per 1f of supported transition metal catalyst.

In the present invention, the organoaluminum includes trialkylaluminum such as triethylaluminum, tripropylaluminum, lJ phthylaluminum, tripentylaluminum, and trihexylaluminum, diethylaluminum chloride, diglopylaluminum chloride, dibutylaluminum chloride, dialkylaluminum chloride, Dialkyl aluminum chlorides such as dialkyl aluminum chloride and those in which chlorine is replaced with bromine or iodine are preferably used. What is most effective in the present invention is the use of a catalyst system in combination with the above-mentioned transition metal catalyst that yields 1 kg or more of polypropylene per 1 g of organic aluminum.

As the propylene used in the present invention, 1 ordinary AA
For example, when polymerizing a type catalyst or a modified type catalyst thereof, the temperature is 70°C.
It is a normal polymerization grade propylene that gives propylene of 1 kg or more per 1 g of AA type catalyst and 100 F or more per organoaluminum when polymerized for 3 hours using a bulk polymerization method using propylene itself as a medium. 95% or more, H2C, CO2, Co, CO3, As
Polymerization inhibiting components such as H3 are expressed as total oxygen content, total sulfur content, total arsenic content, etc., and are removed to a few ppm or less of K.

In the present invention, the conditions for the bulk polymerization method or gas phase polymerization method are that the polymerization pressure is 10 kQ/cJ-gauge to 5 Q kg.
/d-gauge, the polymerization temperature is room temperature to 90°C,
It also includes performing a copolymerization reaction with other olefins such as ethylene, butene-1+hexene-1, etc.

What is important in the present invention is to dissolve a portion of the organoaluminum originally to be used in propylene before introducing it into the polymerization zone. That is, the total amount of organoaluminum introduced into the polymerization zone together with propylene and organoaluminum introduced as a catalyst is the amount of organoaluminum that should be used. This indicates that the present invention does not intend to increase the polymerization activity by increasing the amount of organic aluminum used.

The amount of organic aluminum dissolved in propylene is approximately 1 to 2,500 ppm; less than 1 ppm is ineffective, and 2,500 ppm or more is because the amount of organic aluminum used exceeds the intended amount. . This is because in the gas phase polymerization method and bulk polymerization method, only 40% of the propylene used is usually polymerized.
With the combination of 0% and 2500ppm, the yield of polypropylene per 1f of organic aluminum is 1 kg.
This is because it becomes . Preferably 5-11000
It is pp.

In the present invention, it is not preferable to dissolve the entire amount of organoaluminum used in propylene, because impurities in the solvent used as a dispersion medium when introducing the supported transition metal catalyst into the polymerization zone reduce the catalytic activity. This is because it is preferable to introduce a portion of the polymer into the polymerization zone together with the supported transition metal catalyst.

Effect The reason for the effect of the present invention is not clear, but the organoaluminum required to form polymerization active sites on the supported transition metal catalyst is small (a considerable portion of the organoaluminium is
Since the polymerization-inhibiting components are consumed to render them harmless, it is presumed that the method of the present invention is more effective for protecting the active sites on the supported transition metal catalyst.

Examples Experimental Example 1 Production of transition metal catalyst with support A pulverizer equipped with two pulverizing pots each having an internal volume of 900 mm and containing 80 stainless steel balls each having a diameter of 121 Il is prepared. 20g of magnesium chloride in each pot,
Tetraethoxysilane 4-5α.

A carrier was prepared by charging 3-1/3 of α1α-trichlorotoluene and co-pulverizing for 40 hours. Then 200. In a flask containing 10 μg of carrier and 100 μg of titanium tetrachloride, heat and stir at 80° C. for 2 hours, then leave to stand and remove the supernatant.
．． The operation of charging z-n-heptane, stirring, standing still, and removing the supernatant was repeated seven times, and 100-heptane was further added to prepare a carrier-attached transition metal catalyst slurry.

Experimental Example 2 (Polymerization Numbers 1 to 4) Eighty-two samples of purified globylene (HL grade) manufactured by Osaka Petrochemical Co., Ltd. (A) were obtained at different times.

The purity of each is 99.95%, propane 600 mol ppm, ethane, ethylene 20 mol ppm, acetylene, diene not detected, total sulfur 0.1 mol ppm
CO2, CO is 0.1 mol ppm or less, water is 1.0 in A,
B was 1.1.

Polymerization was carried out using the catalyst prepared in Experimental Example 1 in a 5/5 autoclave. The polymerization reaction begins with 100. ,/N-Heflin under a nitrogen stream under the conditions shown in the table, and then the above Experimental Example 1.
The supported transition metal catalyst 30w9 prepared in 1. was added and mixed, then placed in an auto-freaker, and then propylene was combined with alkyl aluminum under the conditions shown in the table, and then charged and hydrogen was added to 1.4
After charging Nz, polymerization was carried out at 75°C for 2 hours, and unreacted propylene was poured into a polymer, dried at 80°C, 501wHp for 6 hours, and then weighed. The obtained powder was further heated at 135°C.
The intrinsic viscosity of the tetralin solution was further calculated by boiling n-hebutane for 6 hours.

Experimental Example 3 (Polymerization No. 5) Titanium trichloride catalyst (manufactured by Marubeni Solve-A Co., Ltd., T
MU-27, 10011P) at a polymerization temperature of 70°C.
, the amount of hydrogen charged is 2. 4 N! ! Binding, diethylaluminum chloride 1.0- as organic aluminum
The results of polymerization using the above are shown in the table.

Effects of the Invention As shown in the experimental examples, in a catalyst system that has relatively high activity but uses a large amount of organoaluminium (low yield per organoaluminium), even high-purity propylene with the same activity cannot be attached to a carrier. Transition metal catalysts have higher yields (although they vary, it is possible to achieve almost the same activity by implementing the method of the present invention, which is extremely effective in controlling the polymerization of polypropylene on an industrial scale.

Claims (1)

[Claims] A bulk polymerization method using propylene itself as a medium or a gas phase polymerization method using a supported transition metal catalyst obtained by supporting titanium halide on a support containing at least magnesium halide and a catalyst consisting of organoaluminium. A method for polymerizing propylene, characterized in that the propylene used is one in which at least a part of the above organic aluminum is dissolved.