JPH0460130B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for medium-low pressure polymerization of ethylene. JP-A-55-78004 discloses that a titanium-containing solution obtained by bringing a complex formed from magnesium chloride and 2-ethylhexyl alcohol and a titanium compound into contact with each other in the presence of a hydrocarbon solvent is used to dissolve titanium during ethylene polymerization. A method of using it as a component has been proposed. According to the proposed method, since the titanium component is a uniform solution, the titanium component can be quantitatively supplied to the polymerization reaction, and a homogeneous ethylene polymer can be obtained. However, in the above method, several times the molar amount of 2-
Since ethylhexanol is used, odor is observed in the produced polymer, and furthermore, there are problems in that the amount of ethylene polymer produced per catalyst used in the polymerization reaction is not necessarily high. The present invention provides an ethylene polymerization method that solves the above problems. That is, the present invention provides ethylene or a mixture of ethylene and an α-olefin having 3 or more carbon atoms, [A] magnesium 2-ethylhexanoate, and the formula X ¹ _n Ti(OR ¹ ) _4-n (wherein, X ₁ represents a chlorine atom, a bromine atom, or an iodine atom, R ₁ represents a hydrocarbon group having 1 to 20 carbon atoms, and m is a number of 0 to 4. A titanium-containing solution obtained by contacting in the presence of a hydrogen solvent, and [B] Formula R ² _o AlX ² _3-o (wherein, X ² represents the same atom as X ¹ above, and R ²
represents an alkyl group having 1 to 12 carbon atoms or a phenyl group, and n is a number greater than 1 and less than 3. )
In the presence of a catalyst obtained from an organoaluminum compound represented by
This is a method for polymerizing ethylene, which is characterized by polymerizing under a pressure of less than 200 kg/cm ² . According to the present invention, the following excellent effects are achieved. (1) Since both components [A] and [B] are liquid, both components can be quantitatively supplied to the polymerization reactor. (2) Component [A] and component [B] in the polymerization reactor
Because of its good dispersibility, ethylene polymers of uniform quality can be obtained. (3) Ethylene polymers are obtained in significantly higher yields per catalyst used. (4) Odorless ethylene polymer can be obtained. In the present invention, component [A] is prepared by nitrogen,
It is carried out under an inert gas atmosphere such as argon. Magnesium 2-ethylhexanoate used in the present invention can be prepared, for example, by a reaction known per se as described below. (1) Reaction of dialkylmagnesium or dialkoxymagnesium with 2-ethylhexanoic acid. (2) Reaction between metallic magnesium and 2-ethylhexanoic acid. (3) Reaction of magnesium hydroxide or magnesium oxide with 2-ethylhexanoic acid. Although the magnesium 2-ethylhexanoate obtained by the reaction (3) above may contain water, in the present invention, magnesium 2-ethylhexanoate containing equal moles or less of water is preferably used. Specific examples of titanium compounds include titanium tetrachloride, titanium tetrabromide, methoxytitanium trichloride, ethoxytitanium trichloride, butoxytitanium trichloride, octoxytitanium trichloride, dodecacoxytitanium trichloride, and phenoxytitanium trichloride. , benzoxytitanium trichloride, ethoxytitanium tribromide, ethoxytitanium triiodide, diethoxytitanium dichloride, dibutoxytitanium dichloride, dihexoxytitanium dichloride, triethoxytitanium chloride, tributoxytitanium chloride, trihexoxytitanium chloride, Trioctoxytitanium chloride, tetramethoxytitanium, tetraethoxytitanium, tetrabutoxytitanium, and tetraoctoxytitanium are mentioned. The amount of the titanium compound used is preferably 0.005 to 1 mol, particularly 0.01 to 0.5 mol, per 1 mol of magnesium 2-ethylhexanoate. Specific examples of hydrocarbon solvents include aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; These halides are mentioned. The amount of hydrocarbon solvent used is usually 2
-1 to 1 mole of magnesium ethylhexanoate
It is 100. There is no particular restriction on the method of bringing magresium 2-ethylhexanoate and the titanium compound into contact in the presence of a hydrocarbon solvent, and for example, the following method can be employed. (1) A method of adding a titanium compound to a hydrocarbon solvent solution of magnesium 2-ethylhexanoate. (2) A method of adding the above solution to a titanium compound. (3) A method of adding a hydrocarbon solvent solution of a titanium compound to the above solution. (4) A method of adding a solution of magnesium 2-ethylhexanoate to a solution of a titanium compound. The contact temperature is usually 0 to 300°C, preferably 10 to 300°C.
It is 200℃. There are no particular restrictions on the contact time, which is usually 5 minutes or more. The titanium-containing solution thus obtained is subjected to a polymerization reaction as it is, or diluted with a hydrocarbon solution medium if necessary. Specific examples of organoaluminum compounds (component [B]) include diethylaluminum chloride,
Examples thereof include dibutylaluminum chloride, dihexylaluminum chloride, diethylaluminum bromide, diethylaluminum iodide, diphenylaluminum chloride, and dibenzylaluminum chloride. The amount of organoaluminum compound used is usually 1 to 1 per gram atom of titanium in the titanium-containing solution.
It is 1000 moles. In the present invention, component [A] and component [B]
An ethylene homopolymer or an ethylene copolymer is obtained by polymerizing ethylene or a mixture of ethylene and an α-olefin having 3 or more carbon atoms in the presence of a catalyst obtained from . Specific examples of α-olefins having 3 or more carbon atoms include propylene, butene-1,4-methylpentene-1, and octene-1. Polymerization pressure is normal pressure to less than 200Kg/ ^cm2 , preferably
It is 10-100Kg/ ^cm2 . The polymerization temperature is 30-300°C, preferably 50-200°C. As the polymerization method, known polymerization methods such as gas phase polymerization, slurry polymerization, and solution polymerization can be employed. The molecular weight of the produced ethylene polymer can be easily controlled by adding a molecular weight regulator, such as hydrogen, to the polymerization system. Next, Examples and Comparative Examples will be shown. In the following, "polymerization activity" means the production amount (Kg) of polyethylene per 1 g of titanium in the component [A] used, and "MI" is 2.16 in accordance with ASTMD1238.
Melting index of ethylene polymer measured at 190°C under a load of Kg. Example 1 (1) Preparation of titanium-containing solution (component [A]) Commercially available 2-ethylhexanoic acid was vacuum distilled at 1 mmHg, and the fraction at 76 to 78°C was collected. n- containing 2.58 mmol of n-butylethylmagnesium in a 10 ml solution of Ciel Sol 71 (manufactured by Ciel Chemical) containing 5.71 mmol of 2-ethylhexanoic acid.
2.0 ml of heptane solution was added dropwise. After finishing dropping,
The temperature was raised to 90°C and stirred for 1 hour to obtain a colorless and transparent solution. Add tetra-n-butoxytitanium to the above solution.
0.64 ml of n-heptane containing 0.185 mmol was added to obtain 13.4 ml of a homogeneous solution. 120.6ml of this solution
The mixture was diluted with n-heptane to obtain component [A]. (2) Polymerization The above component [A] (1.38
10 ^-3 milligram atoms) sealed in a glass ampoule. After thoroughly purging the system with nitrogen gas, purify n-heptane by dehydration and distillation.
ml was introduced into the autoclave and then n containing 0.69 mmol of diethylaluminum chloride.
- 5 ml of heptane solution were introduced. n-heptane
Added another 500ml and sealed. The autoclave contents were heated to 80°C. Ethylene was then introduced at a partial pressure of 10 Kg/cm ² . Stirring was started, and the catalyst-filled ampoule was crushed to initiate polymerization. During polymerization, polymerization temperature 80℃, ethylene partial pressure 10
Kg/ ^cm2 was maintained. After 1 hour, 10 ml of isopropanol was forced into the autoclave to stop the polymerization and release unreacted monomers. 140.1g of white polyethylene
was gotten. The polymerization activity was 2120, and the density of the produced polyethylene was 0.943 g/cm ³ . No odor was observed from the polyethylene produced. Examples 2 and 3 The amount of tetra-n-butoxytitanium used was 0.278
Example 1 was repeated except that mmol (Example 2) or 0.148 mmol (Example 3) was changed. The results are shown in Table 1. Table 1 Examples Polymerization activity density (g/cm ³ ) 2 1800 0.942 3 2400 0.941 Examples 4 and 5 Amount of diethylaluminium chloride used
Example 1 was repeated except that 0.345 mmol (Example 4) or 0.966 mmol (Example 5) was changed. The results are shown in Table 2. Table 2 Examples Polymerization activity density (g/cm ³ ) 4 2230 0.940 5 2100 0.944 Examples 6 and 7 Except that 0.185 mmol of the titanium compound listed in Table 3 was used instead of tetra-n-butoxytitanium. Example 1 was repeated. The results are shown in Table 3.

TABLE Examples 8 and 9 Example 1 was repeated, except that hydrogen was introduced into the autoclave to the partial pressures listed in Table 4 prior to the introduction of diethylaluminum chloride. The results are shown in Table 4.

[Table] Example 10 Component [A] (0.69 as Ti) prepared in Example 1 was placed in an autoclave with an internal volume of 1 equipped with a stirrer.
After attaching a glass ampoule containing 10 ^-3 milligram atoms), the air in the autoclave was replaced with nitrogen. 2 ml of n-heptane containing 0.345 mmol of diethylaluminum chloride and then hydrogen were introduced into the autoclave until the pressure reached 5 kg/cm ² , after which 100 ml of liquid butene-1 and 500 ml of n-butane were introduced into the autoclave.
ml was press-fitted into an autoclave. The autoclave contents were heated to 66°C. The internal pressure of the autoclave at this time was 17.7 Kg/cm ² . After introducing ethylene into the autoclave until the total pressure reaches 28Kg/ ^cm2 , stirring is started to crush the glass ampoule, and ethylene and butene are heated at 66°C for 60 minutes.
1 was copolymerized. Ethylene was continuously fed during the polymerization to maintain the total pressure at 28 Kg/cm ² . After the polymerization reaction, unreacted monomers and n-
Releases butane and produces white ethylene-butene-1
77.7 g of copolymer was obtained. The density of the copolymer is 0.932
g/cm ³ , MI was 3.1 g/10 min, specific gravity was 0.31, and polymerization activity was 2350. Example 11 (1) Preparation of titanium-containing solution (component [A]) Using Cielsol 71 30 as a solvent, 78 mol of magnesium oxide and 77.1 mol of 2-ethylhexanoic acid purified by distillation were stirred at 170°C under a nitrogen atmosphere. The reaction was allowed to proceed for 10 hours. After the reaction, the reaction mixture was passed through a wire mesh filter with diatomaceous earth to obtain a transparent liquid. The mixture was slowly cooled to 120°C and stirred at 100 mmHg for 2 hours. Cielsol 71 of magnesium 2-ethylhexanoate thus obtained
The magnesium content inside is 3.12wt% as metal.
It was hot. Moreover, the water content in the obtained magnesium 2-ethylhexanoate solution was 4952 ppm. 5.0 g of Cielsol 71 solution of magnesium 2-ethylhexanoate obtained above was taken and 0.5 ml of n-heptane containing 0.46 mmol of tetra-n-butoxytitanium was added to obtain 5.5 ml of a homogeneous solution. Next, 327 ml of n-heptane was added to dilute the mixture to obtain component [A]. (2) Polymerization The above component [A] is 1×10 ^-3 in terms of titanium atoms.
Polymerization of ethylene was carried out in the same manner as in Example 1 except that gram atoms were used. The polymerization activity is 2600, and the density of the polyethylene produced is
It was 0.943g/ ^cm3 .

[Brief explanation of the drawing]

FIG. 1 shows a flowchart of the manufacturing process of the catalyst of the present invention.

Claims (1)

[Claims] 1. Ethylene or ethylene and α- having 3 or more carbon atoms
A mixture with olefin, [A] magnesium 2-ethylhexanoate, and ^the formula X ¹ _n Ti ⁽ OR ¹ ) _4-n (wherein, represents a hydrocarbon group having 1 to 20 carbon atoms, and m is a number of 0 to 4.) A titanium-containing solution obtained by contacting a titanium compound represented by: B] Formula R ² _o AlX ² _3-o (wherein, X ² represents the same atom as X ¹ above, and R ²
represents an alkyl group having 1 to 12 carbon atoms or a phenyl group, and n is a number greater than 1 and less than 3. )
In the presence of a catalyst obtained from an organoaluminum compound represented by
A method for polymerizing ethylene, characterized in that the polymerization is carried out under a pressure of less than 200 kg/ ^cm2 .