JPH0776253B2 - Polymerization method of propylene - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for polymerizing propylene. Specifically, it relates to a method for producing highly crystalline polypropylene by using a specific catalyst.

[Prior Art] Polypropylene is a polymer having excellent rigidity and is used in various ways. However, there is a problem in that the crystallinity of the molded product is relatively low, and the physical properties of ordinary molded products are inferior to those originally expected. On the other hand, it has been attempted to add various nucleating agents for improvement, and a molded product excellent in rigidity and transparency has been obtained.

[Problems to be solved by the invention]

The method of adding the nucleating agent is simple and effective, but it is necessary to add a relatively large amount of the nucleating agent. Therefore, the dispersion of the nucleating agent may cause variations in the physical properties of the molded product or the added nucleating agent may bleed. There is a problem to do, it has been attempted to improve by adding a specific polymer compound, but not enough,
A more effective method is desired.

[Means for solving problems]

The present inventors earnestly searched for a more effective method and arrived at the present invention.

That is, the present invention is a transition metal catalyst component and R _n AlX _3-n (R:
In a method for polymerizing propylene using a catalyst consisting of an alkylaluminum group, X: C1, Br or I, an organoaluminum compound represented by n = 1 to 3), a transition metal catalyst component is ultrasonicated in the presence of talc. A method for producing a highly crystalline polypropylene, which is a solid catalyst component obtained by supporting titanium trichloride or titanium tetrachloride on a carrier obtained by reacting a halogenated hydrocarbon compound with a Grignard reagent while irradiating Is.

In the present invention, the transition metal catalyst component to be used is characterized, and more specifically, the catalyst having titanium trichloride or titanium tetrachloride supported on a specific carrier is used.

The carrier for supporting titanium trichloride or titanium tetrachloride is manufactured by reacting a halogenated hydrocarbon compound with a Grignard reagent in the presence of talc under ultrasonic irradiation.

As the halogenated hydrocarbon compound, chloride having 1 to 20 carbon atoms is preferable. As the Grignard reagent, a halogenated hydrocarbon compound, preferably one produced by reacting bromide or iodide having 1 to 20 carbon atoms with metallic magnesium in a solvent containing ether is usually used.

Irradiation with ultrasonic waves need not be always performed during the reaction between the halogenated hydrocarbon and the Grignard reagent, and may be performed intermittently or only at the beginning of the reaction.

Talc, a hydrous silicate of magnesium (a rock commonly referred to as cobblestone that is refined and pulverized as needed)
Is added to the carrier produced by the above reaction so that the amount ratio occupies 1/1000 to 1/2, preferably 1/100 to 1/3.

In the present invention, prior to supporting the carrier obtained in the above reaction with titanium trichloride or titanium tetrachloride, or during supporting, an electron-donating compound, specifically, an ester,
When treated with oxygen-containing compounds such as ethers, orthoesters and alkoxy silicons, nitrogen-containing compounds such as amines and amides, phosphorus-containing compounds such as phosphoric acid esters and phosphorous acid esters, propylene is obtained using the resulting catalyst. It is also possible to improve the stereoregularity of the obtained polypropylene or the activity per transition metal catalyst component when polymerizing the above.

As titanium trichloride or titanium tetrachloride used for supporting,
Liquid titanium trichloride is preferably used, such as titanium tetrachloride or titanium trichloride solubilized in a hydrocarbon solvent with an electron-donating compound or the like.

The carrier can be supported by simply contacting the above-mentioned carrier with titanium trichloride or titanium tetrachloride, but it is preferable to disperse the carrier in liquid titanium trichloride or titanium tetrachloride under heating and carry out contact treatment.

In the present invention, propylene is prepared by using the above transition metal catalyst and a catalyst composed of an organoaluminum compound represented by R _n A1X _3-n (R: alkyl group, X: C1, Br or I, n = 1 to 3). Polymerized.

Where R _n A1X _3-n (R: alkyl group, X: C1, Br or I, n =
As the organoaluminum compound represented by 1 to 3),
Examples include trialkylaluminum, dialkylaluminum halides, alkylaluminum sesquihalides, and alkylaluminum dihalides, examples of alkyl groups include methyl, ethyl, propyl, butyl, and hexyl groups, and examples of halides include chlorine and bromine. ,
It is iodine.

At this time, a stereoregularity improver, for example, the compounds listed as the above-mentioned electron-donating compounds can also be used in combination during the polymerization, which is effective for improving the stereoregularity of polypropylene. , Oxygen-containing compounds such as esters, orthoesters and alkoxy silicon compounds are preferable.

In the present invention, the polymerization of propylene may be carried out in a hydrocarbon solvent, for example, in an inert medium such as pentane, hexane, heptane, decane, benzene, toluene, xylene, etc., or a bulk polymerization method using propylene itself as a liquid medium, or It can also be carried out by a gas phase polymerization method in which substantially no liquid medium exists, and the polymerization temperature is room temperature to 100 ° C. and the polymerization pressure is normal pressure to 50 kg / cm ² gauge.

The present invention is not limited to homopolymerization of propylene, but also copolymerization with a small amount up to several% of other α-olefins such as ethylene, and in the latter stage, ethylene or other α-olefin, if necessary, is not added to the polymerized polymer. It can also be applied to the production of a so-called block copolymer, which is a copolymerization that accounts for 20 to 95 wt% of the coalescence.

〔Example〕

 Hereinafter, the present invention will be further described with reference to examples.

Example 1 A 300 ml flask was charged with 1 g of talc, 16 g of carbon tetrachloride and 50 ml of diethyl ether, and an ultrasonic generator (BRANSON model 1200J, 45 kHz, 30 W) while stirring a Grignard reagent obtained from 2 g of magnesium and 9.5 g of methyl bromide. Ultrasonic waves were irradiated for 10 minutes from the start of the reaction, and the mixture was added dropwise over 1 hour under boiling ethyl ether to obtain a solid component. Partial analysis revealed that it contained 5 wt% talc. After separating the solid part, put 5g into a 200ml flask and add 50m of titanium tetrachloride.
l, toluene 50 ml, diisobutyl phthalate 0.8 ml,
Stir at 110 ° C. for 1 hour, let stand and remove the supernatant,
Further, add 50 ml of titanium tetrachloride and 50 ml of toluene, and add 110 ° C.
The mixture was stirred with, and the supernatant was again allowed to stand and separate. Then, the solid content was washed with n-heptane to obtain a transition metal catalyst component. When a part of it was taken out and analyzed, it contained 3.2 wt% of titanium.

This transition metal catalyst component 20 mg, triethylaluminum 0.
15 ml, 0.03 ml of trimethoxyphenylsilane and 100 ml of n-heptane were mixed to prepare a catalyst slurry, which was placed in an autoclave having an internal volume of 5, 1.8 kg of propylene and 3.3 Nl of hydrogen were added, and a polymerization reaction was carried out at 75 ° C for 2 hours. After the polymerization reaction, the unreacted propylene was purged and the polymer was taken out to 80
After drying at 60 ° C. and 60 mmHg for 12 hours, 640 g of powder was obtained.

The intrinsic viscosity of the obtained polymer (measured with a tetralin solution at 135 ° C., hereinafter abbreviated as η) and the extraction residual ratio when extracted with a Soxhlet extractor for 6 hours with boiling n-heptane (hereinafter referred to as II and The powder weight after extraction / the powder weight before extraction is expressed as a percentage) was measured. Further, a phenol-based stabilizer (10,000 weight ratio) and calcium stearate (15/10000 weight ratio) were added to some powders, and the mixture was granulated, and then the melt flow index (hereinafter abbreviated as MI) was measured. In addition, a 1 mm thick injection sheet was prepared and the bending rigidity was measured.

MI ASTM D-1238 (230 ° C) Flexural rigidity ASTM D-747-63 (20 ° C) Furthermore, using a differential thermal analyzer, the temperature is raised or lowered at 10 ° C / min, and the melting point and crystallization temperature are the maximum peaks. Was measured as the temperature.

The results are shown in the table.

Comparative Example 1 Propylene was polymerized in the same manner as in Example 1 except that the transition metal catalyst component prepared in the same manner as in Example 1 was used without using talc and without irradiating ultrasonic waves to obtain 608 g of polypropylene. . The physical properties of the obtained polypropylene were measured.

The results are shown in the table.

Comparative Example 2 The polypropylene powder obtained in Comparative Example 1 was supplemented with 300 p of talc.
It was added so as to be pm, and after granulating in the same manner as in Example 1, the physical properties were measured.

The results are shown in the table.

Comparative Example 3 A carrier was synthesized without irradiating ultrasonic waves, and the following Example 1 was used.
In the same manner as above, 585 g of a polymer was obtained.

The other results are shown in the table.

Example 2 Instead of 16 g of carbon tetrachloride, 4 g of carbon tetrabromide and 20 g of propane chloride
The transition metal catalyst component prepared in the same manner as in Example 1 was used except that the mixture of
Propylene was polymerized in the same manner as in Example 1 except that it was used to obtain 570 g of polypropylene. The obtained powder was used and evaluated in the same manner as in Example 1.

The results are shown in the table.

Example 3 In the same manner as in Example 1 except that 16 g of ethane iodide was used instead of 16 g of carbon tetrachloride, 520 g of polypropylene was obtained. The physical properties of the obtained powder and molded product are those with an intrinsic viscosity of 1.59.
dl / g, bulk specific gravity 0.46g / ml, II 98.0wt%, melting point 162.3 ° C,
Crystallization temperature 120.5 ℃, MI 6.9g / 10min, flexural rigidity 12700kg /
It was cm ² .

[Effects of the Invention] By carrying out the method of the present invention, it is possible to produce polypropylene having excellent physical properties, which is extremely valuable industrially.

[Brief description of drawings]

 FIG. 1 is a flow chart for helping understanding of the present invention.

Claims (1)

[Claims] 1. Propylene using a catalyst comprising a transition metal catalyst component and an organoaluminum compound represented by R _n AlX _3-n (R: alkyl group, X: C1, Br or I, n = 1 to 3). In the method of polymerizing the above, the transition metal catalyst component is reacted with a halogenated hydrocarbon compound and a Grignard reagent while irradiating ultrasonic waves in the presence of talc, and titanium trichloride or titanium tetrachloride is supported on the carrier obtained. A method for producing a highly crystalline polypropylene, which is the obtained solid catalyst component.