JPH0311284B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for stereoregular polymerization of α-olefins. Specifically, the present invention relates to a method of polymerizing α-olefin using a solid catalyst supported on special magnesium chloride. Regarding the method of polymerizing α-olefin using a catalyst in which titanium halide is supported on magnesium halide, many improved methods have been proposed since it was proposed in Japanese Patent Publication No. 39-12105, and considerably superior catalysts have been provided. It is being done. However, unlike the polymerization of ethylene, in the polymerization of α-olefins such as propylene, it is necessary to control the stereoregularity, and the catalysts currently on the market do not require the removal of catalyst residues. In order to reduce the amount of residue, further improvement in catalyst activity is desired. As a result of various studies, the present inventors found that a specific method using a solid catalyst obtained by contacting a known liquid organic compound and magnesium chloride co-pulverized product with titanium tetrachloride under heating was developed. The present invention was completed based on the discovery that the activity was significantly increased by using magnesium chloride. The present invention is a method for polymerizing α-olefin using a solid catalyst obtained by co-pulverizing magnesium chloride and a liquid organic compound and then contacting it with titanium tetrachloride under heating, and a catalyst consisting of an organoaluminum compound. 0.1% by weight or more and 2% by weight of moisture measured by Karl Fischer method as magnesium chloride.
α- characterized by using one containing the following:
This invention relates to an olefin polymerization method. An object of the present invention is to provide a method for polymerizing α-olefins by significantly improving the performance of known supported magnesium chloride catalysts. In the present invention, known methods can be applied to produce the solid catalyst. Magnesium chloride, oxygenated compounds such as carboxylic acid esters, orthocarboxylic acid esters, ethers, acetals, benzene,
Co-pulverization with liquid compounds such as aromatic compounds such as toluene, xylene, and cumene, and halogenated hydrocarbons such as methylene chloride, dichloroethane, trichloroethane, chloropropane, and trichlorotoluene, followed by heating with liquid titanium halides such as titanium tetrachloride. It is a method of contact. Oxides such as Al ₂ O ₃ , SiO ₂ , AlCl ₃ ,
Of course, it is also possible to coexist with chlorides such as NaCl _{and CaCl2} . In addition, there is a method in which the contact with titanium tetrachloride is repeated, or a method in which titanium tetrachloride is diluted with a hydrocarbon compound, or a method in which titanium trichloride is complexed with ether and solubilized in a hydrocarbon compound. A method using liquid titanium halide can be applied. In the present invention, when producing a solid catalyst by the above method, magnesium chloride has a moisture content of 0.1% by weight or more and 16% by weight as measured by the Karl Fischer method.
The purpose is to use the following: The preferred moisture content is 0.2% to 2% by weight.
This hydrated magnesium chloride can be produced by adding water to commercially available anhydrous magnesium chloride, or by bringing it into contact with water-containing nitrogen, air, or the like. In the method of the present invention, the polymerization of α-olefins is carried out using, for example, propylene, butene-1, hexene-1
Homopolymerization and copolymerization, copolymerization with ethylene, or block copolymerization in a hydrocarbon medium or bulk polymerization using the monomer itself as a medium, or gas phase polymerization in which there is substantially no liquid medium. It is legal and usually carried out at normal pressure to 50Kg/cm ² -gauge pressure and room temperature to 100℃. By applying the method of the present invention, it is possible to significantly improve the activity of the catalyst, which is of great industrial value. EXAMPLES The present invention will be explained in more detail with reference to Examples below. Example 1 a) Production of solid catalyst: 40 g of commercially available magnesium chloride (moisture 0.05 wt%)
was placed in a grinding pot with an internal volume of 600 ml, filled with 80 stainless steel balls with a diameter of 12 mm, and ground for 2 hours.The resulting mixture was placed in a round bottom flask, and by introducing air into the flask, a concentration of 0.4 wt% was obtained. Contains moisture. Next, 20 g of magnesium chloride containing the above 0.4 wt% water, 3 ml of orthoethyl acetate, 1,2-
2 ml of dichloroethane was placed in the same grinding pot as above under a nitrogen stream, and the mixture was ground at 30°C for 40 hours.
Next, 10 g of the co-pulverized material was placed in a 200 ml round bottom flask under a nitrogen stream, and 50 ml of titanium tetrachloride was added thereto at 80°C for 2 hours.
A solid catalyst slurry was obtained by repeating the operation of contact treatment under stirring for a period of time, followed by static separation to remove excess titanium tetrachloride and washing the solid portion with 100 ml of n-heptane seven times. A sample of a portion of the solid catalyst was analyzed and found to contain 2.3% by weight of Ti. b) Polymerization reaction: Prepare an autoclave with an internal volume of 5 that is sufficiently dried and purged with nitrogen. Thoroughly dried and replaced with nitrogen
Pour 50 ml of dried n-heptane purged with nitrogen into a 200 ml flask, add 0.24 ml of diethylaluminum chloride, 0.14 ml of methyl toluate, 0.20 ml of triethyl aluminum, and 30 mg of the solid catalyst obtained in step (a) to make a mixed catalyst slurry. was charged into the above autoclave, then 1.5 kg of propylene,
0.6Nl of hydrogen was charged, and then the autoclave was heated to carry out polymerization at an internal temperature of 75°C for 2 hours. After the polymerization reaction, unreacted propylene was discharged, then the polypropylene powder was taken out, dried at 60°C for 10 hours, weighed, and the intrinsic viscosity number (hereinafter abbreviated as [η]) and bulk specific gravity were determined with a tetralin solution at 135°C. Ta. Also, boiling water using a Soxhlet extractor
- Extract the powder with heptane for 10 hours and boil n-
Heptane extraction residual rate (polymer weight before extraction / polymer weight before extraction x 100 (
%), the following is abbreviated). The results are shown in the table. Comparative Example 1 A solid catalyst was produced in the same manner as in Example 1, except that commercially available magnesium chloride (water content: 0.05 wt%) was used as it was, and then polymerized in the same manner as in Example 1. The results are shown in the table. Examples 2 to 4, Comparative Examples 2 and 3 The same experiment as in Example 1 was conducted except that co-pulverization was carried out under the conditions shown in the table. The results are shown in the table. 【table】

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the steps for preparing a catalyst used in the method of the present invention.

Claims (1)

[Claims] 1. In a method of polymerizing α-olefin using a catalyst consisting of a solid catalyst obtained by co-pulverizing magnesium chloride and a liquid organic compound and then contacting it with titanium tetrachloride under heating and an organoaluminium compound, A method for polymerizing α-olefin, characterized in that magnesium chloride contains a water content of 0.1% by weight or more and 2% by weight or less as measured by the Karl-Fishier method.