JPS646205B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a method for polymerizing α-olefins. When polymerizing α-olefins having 3 or more carbon atoms,
By using a catalyst obtained from a solid catalyst component in which tanium tetrahalide is supported on a magnesium compound and an organoaluminium compound, it is possible to reduce the amount per solid catalyst component to the extent that it is possible to omit the operation of removing catalyst residue from the produced polymer. Numerous proposals have been made for ways to increase the polymer yield. However, the proposed method has the following problems that need to be solved. (1) The polymer yield per solid catalyst component is not so large as to make removal of catalyst residue unnecessary. (2) The polymerization activity of the catalyst decreases in a short period of time. (3) Large amounts of hydrogen are required in reducing the molecular weight of the polymer, as the catalyst is not sensitive to hydrogen used as a molecular weight modifier for the polymer. The present invention provides a method for polymerizing α-olefins that solves the problems in the proposed method. That is, this invention provides boron halide and a compound having the formula R ¹ nSi(OR ² ) ₄ -n [] (wherein R ¹ represents an alkyl group or phenyl group having 1 to 8 carbon atoms, and R ² represents a carbon number represents an alkyl group of 1 to 8, n is 0, 1, 2 or 3)
A Grignard compound represented by the formula R ³ MgX [ ] (wherein R ³ represents an alkyl group having 1 to 8 carbon atoms, and X represents a halogen atom) is added to the reaction product with the organosilicon compound represented by a solid catalyst component obtained by contacting the resulting solid with titanium tetrahalide, treating the resulting titanium-containing solid with an organic acid ester, and then contacting the ester-treated solid with titanium tetrahalide; Using a catalyst obtained from an organoaluminum compound represented by AlR ⁴ ₃ [ ] (in the formula, R ⁴ represents an alkyl group having 2 to 6 carbon atoms), in the presence of an organic acid ester, This is an α-olefin polymerization method characterized by polymerizing the above α-olefin. According to this invention, since the polymer yield per solid catalyst component is extremely large, it is possible to omit the operation for removing catalyst residues from the produced polymer, and the polymerization activity of the catalyst does not drop suddenly. Furthermore, since the catalyst is sensitive to hydrogen used as a molecular weight regulator, the excellent effect of easily lowering the molecular weight of the polymer with a small amount of hydrogen is achieved. FIG. 1 shows the method for polymerizing α-olefin of the present invention and the process for preparing the solid catalyst component used in the polymerization. In this invention, the solid catalyst component is prepared using substantially anhydrous compounds under an inert gas atmosphere such as nitrogen, argon, etc. Specific examples of the boron halide in this invention include boron chloride, boron bromide, boron iodide, etc. Among them, boron chloride is preferably used. Specific examples of the organosilicon compound represented by the formula [] include tetramethoxysilane, tetraethoxysilane, tetra-n-butoxysilane, tetraisopentoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-
n-butoxysilane, methyltriisopentoxysilane, methyltri-n-hexoxysilane, methyltriisooctoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane,
Ethyltriisopentoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, isopentyltriethoxysilane, isopentyltri-n-butoxysilane, dimethyldiethoxysilane, dimethyldi-n-butoxysilane,
Dimethyldiisopentoxysilane, diethyldiethoxysilane, diethyldiisopentoxysilane, di-n-butyldiethoxysilane, diisobutyldiisopentoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisobutoxysilane, triethyliso Propoxysilane, tri-n-propylethoxysilane,
Tri-n-butylethoxysilane, triisopentylethoxysilane, phenyltriethoxysilane, phenyltriisobutoxysilane, phenyltriisopentoxysilane, diphenyldiethoxysilane, diphenyldiisopentoxysilane,
Examples include diphenyldioctoxysilane, triphenylmethoxysilane, triphenylethoxysilane, and triphenylisopentoxysilane. The proportion of boron halide used in the reaction is 0.25 to 10 mol, especially 1 mol of organosilicon compound.
The amount is preferably 0.5 to 2 moles. The reaction between a boron halide and an organosilicon compound is usually carried out by combining both compounds in an inert organic solvent at -50
This is done by stirring for 0.1 to 2 hours at a temperature in the range ~100°C. The reaction proceeds with exotherm, and the reaction product is obtained as a solution in an inert organic solvent. The reaction product can be subjected to the reaction with the Grignard compound as the above solution without being isolated. Among the Grignard compounds represented by the formula [], alkylmagnesium chlorides in which X is a chlorine atom are preferably used, and specific examples thereof include methylmagnesium chloride, ethylmagnesium chloride, n-butylmagnesium chloride, and n-hexylmagnesium chloride. Examples include. The amount of Grignard compound used per mole of organosilicon compound used for the preparation of the reaction product is:
It is preferably 0.05 to 4 mol, particularly 1.5 to 2 mol. There is no particular restriction on the method of reacting the reaction product with the Grignard compound, but an ether solution of the Grignard compound or a solution of a mixed solvent of ether and an aromatic hydrocarbon is gradually added to the solution of the reaction product in an inert organic solvent. Conveniently this is done by addition or addition in the reverse order. As the above-mentioned ether, a compound represented by the formula R ⁵ -O-R ⁶ (in the formula, R ⁵ and R ⁶ represent an alkyl group having 2 to 8 carbon atoms) is preferably used, and specific examples thereof include: Examples include diethyl ether, diisopropyl ether, di-n-butyl ether, and diisoamyl ether. The reaction temperature is usually -50 to 100℃, preferably -20℃
~25℃. There is no particular restriction on the reaction time, but it is usually 5 minutes or more. As the reaction progresses, a white solid precipitates out. The solid thus obtained can be contacted as a reaction product mixture with titanium tetrahalide. It is preferred to wash the formed solid with an inert organic solvent before contacting it with the titanium tetrahalide. Specific examples of titanium tetrahalide in the present invention include titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, and the like, with titanium tetrachloride being preferably used. The amount of titanium tetrahalide used is preferably 1 mol or more, particularly 2 to 100 mol, per 1 mol of the Grignard compound used in preparing the solid. The solid and titanium tetrahalide can be contacted in the presence or absence of an inert organic solvent. The temperature during contact should be between 20 and 200℃, especially
The temperature is preferably 60 to 140°C. There are no particular restrictions on the contact time, but it is usually 0.5 to 3 hours. The titanium-containing solid is separated from the thus obtained mixture containing the titanium-containing solid by filtration, decanting, etc., washed with an inert organic solvent, and then subjected to treatment with an organic acid ester. The titanium-containing solid contains 0.5 to 10% by weight of titanium. Examples of the organic acid ester in this invention include aliphatic carboxylic esters, aromatic carboxylic esters, and alicyclic carboxylic esters. Among these organic acid esters, the formula [In the formula, R ⁷ represents an alkyl group having 1 to 6 carbon atoms, and Y represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or -OR ⁸ (R ⁸ represents an alkyl group having 1 to 4 carbon atoms). ) is shown. Aromatic carboxylic acid esters represented by ] are preferably used, and specific examples thereof include:
Examples include methyl benzoate, ethyl benzoate, methyl toluate, ethyl toluate, methyl anisate, and ethyl anisate. The amount of organic acid ester used is 1 titanium-containing solid.
Preferably it is 0.1 to 10 mmol per g. There are no particular restrictions on the method of treating the titanium-containing solid with an organic acid ester, but a convenient method is to suspend the titanium-containing solid in an inert organic solvent, add the organic acid ester to this suspension, and stir it. Adopted. The treatment temperature is preferably 0 to 200°C, particularly 5 to 150°C. There is no particular restriction on the processing time, but it is usually 5 minutes or more. The ester-treated solid is separated from the mixture containing the ester-treated solid thus obtained by filtration, decanting, etc., washed with an inert organic solvent, and then brought into contact with titanium tetrahalide again. The contact between the ester-treated solid and the titanium tetrahalide can be carried out in the same manner as the contact between the titanium tetrahalide and the solid obtained by reacting the reaction product and the Grignard compound. The solid catalyst component is separated from the thus obtained mixture containing the solid catalyst component by filtration, decanting, etc., and washed with an inert organic solvent. The solid catalyst component contains 0.5 to 5% by weight of titanium. Inert organic solvents used in each step of preparing the solid catalyst component include aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene, benzene, and xylene, and halides of these hydrocarbons. . In this invention, the solid catalyst component and the formula []
An α-olefin having 3 or more carbon atoms is polymerized in the presence of an organic acid ester using a catalyst obtained from an organoaluminum compound represented by: Specific examples of the organoaluminum compound represented by the formula [] include triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, etc. Among them, triethylaluminum and triisobutylaluminum are preferably used. The amount of organoaluminum compound used is usually 1 to 1000 per gram atom of titanium in the solid catalyst component.
It is a mole. The organic acid ester to be present in the polymerization system is
The same organic acid ester used in treating the titanium-containing solid is appropriately selected and used.
The proportion of the organic acid ester present in the polymerization system is 1 to 1 of the organoaluminum compound used for preparing the catalyst.
Preferably, it is 0.05 to 0.6 mol per mol. α having 3 or more carbon atoms polymerized by the method of this invention
- Specific examples of olefins include propylene, 1
-butene, 4-methyl-1-pentene, 1-hexene, etc. Furthermore, in the present invention, a mixture of α-olefins having 3 or more carbon atoms or the above α-olefin and ethylene can be copolymerized. In this invention, the polymerization reaction can be carried out in the same manner as the polymerization reaction of α-olefin using a conventional Ziegler-Natsuta type catalyst. The polymerization reaction can be carried out in liquid phase or gas phase. When the polymerization reaction is carried out in a liquid phase, aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as hexane and heptane, and halides of these hydrocarbons may be used as polymerization solvents. α-olefin itself may be used as a polymerization solvent. There is no particular restriction on the catalyst concentration in the polymerization solvent, but in general, per polymerization solvent,
For solid catalyst components, titanium metal equivalent is 0.001
~1 milligram atom and 0.01 to 100 mmol for organoaluminum compounds. The polymerization reaction is carried out in the substantial absence of moisture and oxygen. The polymerization temperature is usually 30 to 100°C, and the polymerization pressure is usually 1 to 80 kg/cm ² . The molecular weight of the α-olefin polymer obtained by the method of this invention can be easily adjusted by adding hydrogen to the polymerization system. Next, examples will be shown. In the following description,
"Polymerization activity" is the polymer yield (g) per 1 hour of polymerization time per 1 g of solid catalyst component used in the polymerization reaction.
- It is the weight percentage of the extraction residue based on the total polymer when extracted with heptane for 20 hours. Also, “M.
I.'' is the melt flow index measured at 230° C. under a load of 2.16 kg/cm ² according to ASTM D1238. "Al/Ti" indicates the number of moles of organoaluminum compound per gram atom of titanium in the solid catalyst component, and "Al/ester" indicates the number of moles of organoaluminum compound per mole of organic acid ester used in the polymerization reaction. Shows the number of moles. In an example,
All solid catalyst components were prepared in a dry nitrogen gas atmosphere. Example 1 (1) Preparation of solid catalyst component 12.3 mmol of boron chloride was mixed with 15 mmol of toluene at -10°C.
ml, and then 10 ml of toluene in which 12.3 mol of tetraisopentoxysilane was dissolved was added dropwise over 15 minutes with stirring. Although heat generation was observed during the dropwise addition, the temperature of the reaction system was maintained at the above temperature. After the dropwise addition was completed, the temperature of the reaction system was raised to room temperature, and the reaction was continued at the same temperature for 1 hour with stirring. After the reaction mixture was cooled to -10° C., 15 ml of diisoamyl ether containing 22.1 mmol of n-butylmagnesium chloride was added dropwise to the reaction mixture over 40 minutes while stirring. The temperature of the reaction system is -10℃
I kept it. After the dropwise addition was completed, the temperature of the reaction system was raised to room temperature, and the reaction was continued at the same temperature for 1 hour. The precipitated solid was separated and washed with toluene. The solid was suspended in 25 ml of toluene, 93.5 mmol of titanium tetrachloride was added to this suspension, and 93.5 mmol of titanium tetrachloride was added under stirring.
The solid was contacted with titanium tetrachloride for 1 hour at 0C. At the same temperature, the titanium-containing solid was separated and washed with n-heptane and then toluene. 3.05 g of a titanium-containing solid was suspended in 25 ml of toluene, and 5.0 mmol of ethyl benzoate was added to this suspension, followed by stirring at 90° C. for 1 hour. The ester-treated solid was separated at the same temperature and washed with n-heptane and then toluene. Suspend the ester-treated solid in 25 ml of toluene,
93.5 mmol of titanium tetrachloride was added to this suspension, and the ester-treated solid and titanium tetrachloride were brought into contact at 90° C. for 1 hour. The obtained solid catalyst component was separated at the same temperature and washed with n-heptane. 2.93 g of the solid catalyst component thus obtained was suspended in 75 ml of n-heptane. The titanium content of the solid catalyst component was 2.66% by weight. (2) Polymerization A suspension of solid catalyst component (12.4 mm as solid catalyst component) was placed in an autoclave with an internal volume of 1 and equipped with a stirrer.
After attaching the glass ampoule containing mg),
The air in the autoclave was replaced with nitrogen. Triethylaluminum 0.69 mmol (Al/
2 ml of n-heptane containing Ti=100) and 0.17 mmol of metal p-tolylate (Al/ester=4.0)
2.5 ml of n-heptane containing After this, 600 ml of liquid propylene was introduced into the autoclave and the autoclave was shaken. After raising the temperature of the contents of the autoclave to 65℃, stirring was started to crush the glass ampoule, and the temperature was increased to 65℃.
Propylene was polymerized for 1 hour. After the polymerization reaction was completed, unreacted propylene was released, glass fragments were removed, and the resulting polypropylene was dried under reduced pressure at 50°C for 20 hours. 183 g of pure white powdered polypropylene was obtained.
Catalytic activity was 14700 and HI was 92.3%. Examples 2 and 3 Example 1 was repeated except that the amount of triethylaluminum used was varied so that the Al/Ti was as listed in Table 1. In addition, Al/ester is
I changed it to 4.0.

Table Example 4 Example 1 was repeated except that Al/ester was changed to 3.0. The polymerization activity was 7600, and the HI was 96.8%. Example 5 Example 1 was repeated except that the polymerization temperature was changed to 75°C. The polymerization activity was 19500, and the HI was 94.1%. Examples 6 and 7 Example 1 was repeated except that hydrogen was introduced into the autoclave to the pressures listed in Table 2 (gauge pressure) prior to introducing liquid propylene. The results are shown in Table 2.

[Table] Examples 8 to 11 Solid catalyst components were prepared in the same manner as in Example 1, except that the types and amounts of organosilicon compounds listed in Table 3 were used in place of tetraisopentoxysilane. . Table 3 shows the titanium content of the solid catalyst components. Al/Ti:
100, Al/ester: 4.0, propylene was polymerized. The results are shown in Table 3.

【table】 [Brief explanation of drawings]

FIG. 1 is a flowchart showing the method for polymerizing α-olefin of the present invention.

Claims (1)

[Scope of Claims] 1 Boron halide, and the formula R ¹ nSi(OR ² )4-n (wherein, R ¹ represents an alkyl group having 1 to 8 carbon atoms or a phenyl group, and R ² represents a carbon number 1 -8 alkyl group, n is 0, 1, 2 or 3)
A Grignard compound represented by the formula R ³ MgX (wherein R ³ represents an alkyl group having 1 to 8 carbon atoms and X represents a halogen atom) is reacted with the reaction product with the organosilicon compound represented by , a solid catalyst component obtained by contacting the obtained solid with titanium tetrahalide, treating the obtained titanium-containing solid with an organic acid ester, and then contacting the ester-treated solid with titanium tetrahalide, and the formula AlR ⁴ ₃ (wherein, R ₄ represents an alkyl group having 2 to 6 carbon atoms). A method for polymerizing α-olefin, which is characterized by polymerizing olefin.