JPS646208B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing poly-1-butene with a high bulk density by slurry polymerization. Using a Ziegler type catalyst in a hydrocarbon solvent,
When performing slurry polymerization of 1-butene, poly-1
- Butene easily swells in hydrocarbon solvents, resulting in a die-like shape, which often makes polymerization difficult.
For this reason, a two-stage polymerization method in which 1-butene is prepolymerized at a low temperature and then main polymerization is carried out at a temperature higher than the degree of prepolymerization is disclosed in British Patent No. 940145,
-Proposed in No. 8758, etc. However, according to the studies of the present inventors, it is necessary to adjust the prepolymerization temperature to less than 30°C in order to obtain a polymer with a sufficiently large bulk density suitable for slurry polymerization in such a two-stage polymerization method. It turns out that there is. Industrially 30℃
Since operation at temperatures as low as below 100 nm is disadvantageous in terms of reaction temperature control, it was desired to develop other methods. According to the present invention, when α-olefin is prepolymerized to give a highly crystalline polymer other than 1-butene,
It has been found that poly-1-butene having a similar high bulk density can be produced, and that the prepolymerization temperature is preferably as high as 30°C or higher. Therefore, according to the present invention, in a method for producing poly-1-butene by slurry polymerization using titanium trichloride and an organoaluminum compound, a highly crystalline polymer other than poly-1-butene is provided in advance. There is provided a method for producing poly-1-butene, characterized in that α-olefin is polymerized in a range of 0.01 to 10% by weight of the total polymerization amount. A flowchart of the method for producing poly-1-butene according to the present invention is shown in FIG. As the titanium trichloride used in the present invention, 1
-Any polymer that can be used for the stereoregular polymerization of butenes may be used, such as those with the general formula
TiX ₃・nAlX ₃ (X is halogen, 0≦n≦0.5) trihalogenated titanium, especially titanium tetrachloride, is reduced with a reducing agent such as hydrogen, aluminum, titanium, or an organoaluminum compound. Titanium chloride can be cited as a representative example.
Among these, titanium trichloride obtained by reducing with an organoaluminum compound and optionally heat-treating is particularly preferred. The organoaluminum compound used for polymerization is
A compound having a hydrocarbon group directly connected to an aluminum atom, such as trialkylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide, alkylaluminum dihalide, dialkylaluminum alkoxide, dialkylaluminum allyloxide,
These include dialkylaluminum hydrides and alkylaluminum compounds with a structure in which multiple aluminum atoms are linked via oxygen atoms or nitrogen atoms. The alkyl group of the compound preferably has about 1 to 10 carbon atoms, and in the case of a compound containing a halogen, the halogen may be chlorine, bromine, iodine, etc., but particularly preferred. is chlorine. More specifically, triethylaluminum, triisobutylaluminum,
Trialkylaluminum, such as trihexylaluminum, diethylaluminum chloride,
Representative examples include dialkylaluminum halides such as diisobutylaluminum chloride, alkylaluminum sesquihalides such as ethylaluminum sesquichloride and isobutylaluminum sesquichloride, and alkylaluminum dihalides such as ethylaluminum dichloride and isobutylaluminum dichloride. can. Of course, two or more of these can be used in combination. Among these, dialkyl aluminum halides are particularly preferred. In the polymerization, in addition to titanium trichloride and the organoaluminum compound, additives such as electron donors may be present in order to improve polymerization activity, stereoregularity, and the like. Examples of such electron donors include organic acid esters, ethers, ketones, alcohols, amines, and amide compounds. Prepolymerization and main polymerization of the present invention may be performed in the same reactor or in separate reactors. Moreover, it can be carried out by a batch polymerization method or a continuous polymerization method. The concentration of titanium trichloride in the prepolymerization and main polymerization of the present invention is preferably 0.1 to 500mM/l, and the amount of the organoaluminum compound is Al/Ti (atomic ratio).
It is best to select a value between 0.1 and 100, especially between 1 and 10. When an electron donor is used, it is preferably used in an amount equal to or less than the molar amount of the organoaluminum compound. In the main polymerization, a solvent, an organoaluminum compound, and an electron donor may be newly added to the prepolymerization slurry. In the prepolymerization of the present invention, a highly crystalline α-olefin polymer other than poly-1-butene is produced, including ethylene; propylene; 3-methyl-1-butene, 3,3-dimethyl-1 - Methylbutenes such as butene; methylpentenes such as 3-methyl-1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene; 3
-Methyl-1-hexene or the like may be polymerized. Preferable ones are ethylene, propylene or 3
The α-olefin having a branch at the position or the 4-position is particularly preferred, and ethylene, propylene or methylpentene is particularly preferred. Although these are preferably homopolymerized, they may be copolymerized as long as a highly crystalline polymer is obtained. In this case, a small proportion of 1-butene may be copolymerized. The prepolymerization amount is 0.01% by weight or more and 10% by weight or less of the total polymerization amount. Since a large amount of prepolymerization will affect the properties of poly-1-butene, it is preferably 0.01 to 5% by weight of the total amount of polymerization. Prepolymerization may be carried out under conditions such that a highly crystalline polymer of the α-olefin is produced. The temperature for prepolymerization is generally about 20 to 120°C, but the particularly suitable temperature varies depending on the type of α-olefin; for example, in the case of ethylene, it is about 30 to 100°C.
°C, 30 to 80 °C for propylene, and 30 to 80 °C for methylpentene. Prepolymerization is carried out in the presence or absence of an inert hydrocarbon solvent. Inert hydrocarbon media include aliphatic hydrocarbons such as propane, butane, pentane, hexane, octane, decane, dodecane, kerosene,
Examples include alicyclic hydrocarbons such as methylcyclopentane and cyclohexane, aromatic hydrocarbons such as benzene, toluene, and xylene, and halogenated hydrocarbons such as ethylene chloride and ethyl chloride, but especially aliphatic hydrocarbons. It is preferable to use The main polymerization of 1-butene is preferably carried out at 25 to 48
C., more preferably in the range of 30 to 47.degree. When the polymerization temperature exceeds 48°C, a rapid decrease in the bulk density of the polymer is observed. Furthermore, a polymerization temperature lower than 25°C is industrially disadvantageous because the polymerization rate is slow and the heat of reaction cannot be easily removed. The polymerization of 1-butene is carried out in the form of slurry polymerization in the presence or absence of an inert aliphatic hydrocarbon solvent. As the inert aliphatic hydrocarbon solvent, those mentioned above can be used. When no inert aliphatic hydrocarbon is used, 1-butene itself becomes the polymerization solvent. In this polymerization, hydrogen may be present in order to adjust the molecular weight of the polymer. Of course, if desired, hydrogen may also be present in the prepolymerization. After the polymerization is completed, the catalyst can be removed from the polymer using water, alcohol, ketone, carboxylic acid, or other commonly known reagents. The 1-butene polymerization of the present invention can also be applied to cases where a small amount of other α-olefins are copolymerized. Next, it will be explained in detail using examples. Example 1 2 750ml of n-decane in an autoclave,
20mmol diethylaluminium chloride
Add 10 mmol of titanium trichloride. Add 6 g of ethylene at 60°C and react for 1 hour. Thereafter, the temperature in the system was lowered to 35°C, and 225 g of 1-butene was added over 2 hours, and polymerization was continued for another 2 hours. After removing unreacted 1-butene, the solid component was collected by filtration, the catalyst was decomposed and washed with methanol, and then dried to obtain 192 g of unreacted poly-1-butene as a white powder. Bulk density is 0.37
g/ml. Examples 2 to 6 Prepolymerization and main polymerization were carried out in the same manner as in Example 1, using ethylene, propylene, and 4-methyl-1-pentene as prepolymerization monomers. The polymerization conditions and results are shown in Table 1.

[Table] Comparative Example 1 750ml of n-decane in the autoclave of 2,
20mmol diethylaluminum chloride
Add 10 mmol of titanium trichloride. 225g of 1-
When butene was added over 2 hours at 35°C, an additional 2
Polymerized for hours. After removing unreacted 1-butene, the autoclave was opened and poly-1-butene was found to be in the form of a diary.

[Brief explanation of drawings]

FIG. 1 is a flow chart of the method for producing poly-1-butene according to the present invention.

Claims (1)

[Claims] 1. In a method for producing poly-1-butene by slurry polymerization using titanium trichloride and an organoaluminum compound, α- A method for producing poly-1-butene, which comprises polymerizing olefin in an amount of 0.01 to 10% by weight of the total polymerization amount. 2. The method of claim 1, wherein the alpha-olefin is selected from ethylene, propylene and methylpentene. 3. The method according to claim 1 or 2, wherein the prepolymerization of the α-olefin is carried out in an inert hydrocarbon solvent.