JPS5846205B2 - Olefin polymerization method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for polymerizing olefins.

More specifically, the present invention relates to a method for polymerizing olefins using a novel catalyst containing a magnesium compound and a titanium compound.

It is known that catalyst systems containing magnesium and titanium compounds can be used for the polymerization of olefins.

For example, JP-A-51-54889 discloses a catalyst system in which magnesium diethylate, titanium tetrabutylade, and ethylaluminum dichloride are reacted.
No. 4-82395 proposes a catalyst system in which a hydrocarbon-insoluble solid obtained from the reaction of magnesium diethylate and a halogen-containing titanium compound is treated with an acid halide.

High polymerization activity is obtained when olefins are polymerized using these catalyst systems.

As a result of intensive studies, the present inventors used a specific compound as a titanium compound, prepared a homogeneous hydrocarbon solution containing a magnesium compound and a titanium compound, and treated it with an organic aluminum halide compound. The inventors have discovered that the activity of the catalyst can be further significantly increased, and the present invention has been achieved.

That is, the gist of the present invention is that the general formula Mg(OR2)mX
Compounds represented by M-m (wherein R2 represents an alkyl, aryl or cycloalkyl group, X2 represents a halogen atom, and m is 1 or 2) and the general formula Ti (OR
3) A homogeneous hydrocarbon solution containing a compound represented by n , the general formula AlR)

) A method for polymerizing olefins, characterized in that the olefins are polymerized using a catalyst system comprising a combination of a hydrocarbon-insoluble solid obtained by treatment with an organic aluminum halide compound represented by the following formula and an organic aluminum compound.

To further explain the present invention in detail, the magnesium compound has the general formula Mg(OR)mXr-m (wherein R2 represents an alkyl, aryl or cycloalkyl group, X2 represents a halogen atom, and m is 1 or 2 It is.

) is used. Specifically, R2 is an alkyl having up to about 15 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, phenyl, tolyl, xylyl, cyclohexyl, aryl,
Examples thereof include compounds in which the compound is a cycloalkyl group and X2 is chlorine, bromine or iodine, such as dimethoxymagnesium, jetoxymagnesium, ethoxymagnesium chlorite, diphenoxymagnesium, and the like.

Among these, compounds in which m in the general formula is 2 are preferred.

Among them, jetoxymagnesium is most suitable. On the other hand, as a titanium compound, the general formula Ti (OR3) nXj-n
(In the formula, R3 represents an alkyl, aryl or cycloalkyl group, X3 represents a halogen atom, and n is 1, 2 or 3.

) is used.

Examples of R3 and x3 include those exemplified above for R2 and x2. Specifically, compounds where n is 2 include jetoxydichlortitanium, di-n-propoxydichlortitanium, di-n-butoxydichlor Titanium, etc.; Compounds where n is 3 include triethoxymonochlortitanium, tri-n-propoxymonochlortitanium, tri-n-butoxymonochlortitanium, etc.; compounds where n is 1 include ethoxytrichlortitanium, n-propoxytrichlor Examples include titanium and n-butoxytrichlortitanium.

Among these, those where n is 3 or 2, particularly those where n is 3 are preferred.

Among them, tri-n-butoxymonochlorotitanium is most suitable.

In the method of the present invention, first, a homogeneous hydrocarbon solution containing the above-mentioned Magnesium-Tum compound and titanium compound is prepared.

As the hydrocarbon used as a solvent, aliphatic hydrocarbons such as hexane and heptane, and alicyclic hydrocarbons such as cyclohexane may be used, but aromatic hydrocarbons such as benzene, toluene, and xylene are particularly preferred. .

To prepare a hydrocarbon solution, it is preferable to mix a magnesium compound and a titanium compound in advance to prepare a homogeneous liquid.

Depending on the type of compound used, a homogeneous liquid can be obtained by simply mixing the two components and heating, but if it is difficult to produce a homogeneous liquid, it is preferable to include alcohol.

Examples of the alcohol include ethyl alcohol, n--7' alcohol, 0-butyl alcohol, n-pentyl alcohol, and n-octyl alcohol.

The mixing order of the two components is not particularly limited and may be arbitrary.

After mixing, if the mixture is preferably heated to 100°C to 170°C, a uniform liquid or a uniform alcohol solution can be obtained.

Next, a hydrocarbon solvent is added to form a hydrocarbon solution, but if alcohol is used, it is preferable to remove the alcohol by distillation or the like.

In the method of the present invention, the hydrocarbon solution obtained as described above is used with the general formula AlR11 Indicates the number l≦2.

) to prepare a hydrocarbon-insoluble solid.

In the general formula of the organic aluminum halide compound, R1, x
Examples of i include those exemplified above for R2 and X2.

Specific examples include methylaluminum dichloride, methylaluminum sesquichloride, dimethylaluminum monochloride, ethylaluminum dichloride,
Examples include ethylaluminum sesquichloride, diethylaluminium monochloride, isobutylaluminum dichloride, isobutylaluminum sesquichloride, diisobutylaluminum monochloride, and the like.

Particularly preferred are ethylaluminum dichloride, ethylaluminum sesquichloride, and diethylaluminum monochloride, and among them, ethylaluminum sesquichloride gives the most preferable results.

Organic aluminum halide compound treatment involves adding an organic aluminum halide compound to a homogeneous hydrocarbon solution.
Preferably, the reaction may be carried out at a temperature of 20 to 100°C, and since a hydrocarbon insoluble solid is obtained, the solid is separated,
It may be washed with a hydrocarbon solvent.

Therefore, the amount of each component used is determined by the amount of Xl in the general formula of each component.
,X2. The gram equivalent ratios of OR'', OR3, Mg and Ti are selected to satisfy the following formula, and a highly active catalyst can be obtained within this range.

Next, examples of organoaluminum compounds used as cocatalysts include -Naka formula A, 1R4pxi-p (in the formula, R4
represents an alkyl, aryl or cycloalkyl group;
4 represents a halogen atom, and p represents a number from 1 to 3.

) can be mentioned. Examples of R4°X4 include those exemplified as R2 and X2.

Specifically, trialkylaluminum such as triethylaluminum, tri-n-propylaluminum, and triisobutylaluminum is preferred.

The proportion of the hydrocarbon-insoluble solid and the organoaluminum compound used is usually within the range of 0.1 to 100, preferably 1 to 20, in terms of Al/Ti atomic ratio.

The catalyst system thus prepared is used to polymerize olefins, and the olefins used in the process of the invention include alpha-olefins such as ethylene, propylene, butene-1, pentene-1, octene-1, and the like.

Moreover, these olefins can also be mixed and copolymerized.

In particular, the process of the invention is advantageous for the production of ethylene homopolymers or copolymers of ethylene containing up to 10% by weight, preferably up to 5% by weight of other α-olefins.

The polymerization reaction can be carried out by solution polymerization or slurry polymerization carried out in an inert solvent, or by gas phase polymerization carried out in the absence of a solvent.

This is usually carried out by supplying the olefin or olefin mixture and maintaining it at a predetermined temperature and pressure in the presence of an inert solvent.

Inert solvents include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, isooctane, benzene,
Aromatic hydrocarbons such as toluene are used.

The polymerization reaction is usually carried out at a temperature of from room temperature to 200°C and from normal pressure to
It is selected from within the pressure range of 100 atmospheres.

Further, in the method of the present invention, when hydrogen is present in the polymerization reaction zone, the effect of controlling the molecular weight by hydrogen is large, and a polymer having a desired molecular weight can be easily obtained.

The amount of hydrogen that should be present varies depending on the polymerization conditions, the desired molecular weight of the olefin polymer, etc., and therefore it is necessary to adjust the amount of hydrogen introduced accordingly.

According to the method of the present invention as described above, the catalyst system has a very high activity, and not only high productivity can be obtained, but also a polymer having a very narrow molecular weight distribution can be obtained.

Furthermore, the polymer obtained by the method of the present invention, which is obtained by using only the hydrocarbon-soluble fraction of the reaction product of a magnesium compound and a titanium compound, is characterized in that it is extremely difficult to form fish eye.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

In the examples, the polymerization activity of the catalyst is K=(g polymer)/
It was expressed as (g catalyst) (hr) (kg/i olefin pressure), and the polymerization activity KTi per titanium was expressed as KTi=(g polymer)/(g Ti) (hrXkg/ell olefin pressure).

In addition, the melt index is ASTM-D-1238.
Measured at 190℃ and 2.16kg load based on 57T.
Represented by I.

Furthermore, the flow rate ratio (hereinafter abbreviated as PR) as a measure of molecular weight distribution is a value indicating the dependence of melt viscosity on shear stress, and AST
According to M-D・1238・57T, shear stress 10' d
It is expressed as the ratio of the melt index measured at 105 dyne/ci and 105 dyne, and it is said that if the FR is dog, the molecular weight distribution is wide, and if the FR is small, the molecular weight distribution is narrow.

Examples 1 to 4 Magnesium diethylate, tri-n-butoxymonochlorotitanium, and n-butanol were mixed in the proportions shown in Table 1 and stirred at 140°C for 4 hours to obtain a uniform alcohol solution.

Next, butanol was removed under a 140' CN2 stream, the temperature was lowered to 60°C, and a predetermined amount of benzene was added to form a homogeneous solution.

Next, ethylaluminum sesquichloride in the amount shown in Table 1 was added dropwise at 60°C, and the mixture was stirred at 65°C for 1 hour.

The generated precipitate was washed with normal hexane and dried to obtain a solid powder.

Next, add 1000 normal hexane to the 21 autoclave.
cc was taken, and 5 cm of the above solid powder was charged.

After raising the temperature to 90°C, hydrogen was introduced to 1.5 kg/ffl, and together with 0.08 mmo triethylaluminum + ethylene, the total pressure was raised to 5 kg/cr? I set it to L.

Ethylene absorption was observed as ethylene was introduced, but ethylene was additionally introduced to maintain the total pressure at 5 kg/cri't, and 1 hour later, the polymerization was stopped by pressurizing ethanol.

The results obtained are shown in Table 1.

Examples 5 to 6 A hydrocarbon solution was prepared using the same method as in Examples 1 to 4, except that normal butanol was not used, with the component ratios shown in Table 1, and the solution was treated with ethylaluminum sesquichloride to obtain a solid powder. Ethylene polymerization was carried out in the same manner as in Examples 1 to 4 using 5 cm of this solid powder.

The results obtained are shown in Table 1.

Examples 7 to 8 A solid powder was obtained in exactly the same manner as in Example 1 except that ethyl aluminum dichloride or diethylaluminum monochloride was used in place of ethyl aluminum sesquichloride in the proportions shown in Table 1. Ethylene polymerization was carried out in the same manner as in Example 1 using 5 rng of powder.

The results obtained are shown in Table 1.

Examples 9-10 In Example 5, the dropping temperature of ethylaluminum sesquichloride was 20°C in Example 9, and 100°C in Example 10.
A solid powder was obtained in exactly the same manner except that the temperature was changed to .degree. C., and ethylene polymerization was carried out in the same manner as in Example 5 using 5 square meters of this solid powder.

The results are shown in Table 1.

Example 11 In the ethylene polymerization of Example 1, when changing the reaction temperature from 90°C to 70'C and introducing and adding ethylene, butene-1 was mixed and the butene-1/ethylene in the gas phase of the polymerization reaction zone was mixed. Copolymerization of ethylene and butene-1 was carried out in exactly the same manner except that the molar ratio of ethylene and butene-1 was adjusted to 0.06.

The obtained results are shown in Table 1, and the obtained polymer was ethylene-butene-1 containing 1 mol% of butene-1 units.
It was a copolymer.

The results are shown in Table 1. Example 12 21 Put 1000 cc of normal hexane into an autoclave, charge 5 cm of the solid powder obtained in Example 1, and heat at 90°C.
After raising the temperature, hydrogen was introduced to 21 kg/-, then 0.08 mmol of triethylaluminum was introduced together with ethylene, and the total pressure was 26 kg/crI! I set it to L.

Ethylene absorption was observed as ethylene was introduced, but ethylene was additionally introduced to maintain the total pressure at 26 kg/ffl, and polymerization was carried out for 34 minutes.

During this time, 193 g of ethylene was polymerized.

Then, the temperature was lowered to 70℃, and the total pressure was 0.4kg/crt.
Ethylene and hydrogen mixed gas was purged until t.

Next, 12 g of butene-1 was introduced together with ethylene, and the total pressure was 2.0 kg/Cr? Ethylene was additionally introduced to maintain the amount of L, and 68 minutes later, the polymerization was stopped by pressurizing ethanol, resulting in a total of 386 g of ethylene-butene-1 copolymer.

The obtained polymer was pelletized using an extruder.

This pellet had an MI of 0.03 and a PR of 95.

Also, from infrared absorption spectrum analysis, butene-1 unit Q,
It contained 7mo1%.

Furthermore, when a film was made from this pellet, no fish eyes were observed.

Comparative Example 1 A solid powder was obtained in the same manner as in Example 6 except that magnesium diethylate and tri-normal butoxy monochlorchikune were not heat-treated at 140°C and a predetermined amount of benzene was added to form a benzene slurry. When ethylene was polymerized in exactly the same manner as in Example 1 using 5 m9, 89.1 g of polyethylene was produced, and K-6
6oo1KTi-59400, MI-0,70,PR=
23, and there were uneven areas called fish eyes on the skin of the molded product.

Comparative Example 2 Using the same amounts of ingredients as in Example 6, benzene was first added to magnesium diethylate to form a slurry.

Next, ethylaluminum sesquichloride was added at 60°C, and then tri-n-butoxymonochlorchikune was added dropwise, and the mixture was stirred at 65°C for 1 hour to obtain a solid powder in the same manner as in Example 1.

Ethylene polymerization was carried out in exactly the same manner as in Example 1 using 5 cm of this solid powder, and 26 g of polyethylene was produced, K=1940. K = 19800, M
I-0.85, FR=22, and fish eyes were present on the skin of the molded product.

Claims (1)

[Claims] 1 Represented by the general formula Mg(OR")mX2-m (wherein R2 represents an alkyl, aryl or cycloalkyl group, X2 represents a halogen atom, and m is 1 or 2) and the general formula Ti(OR3). X4-n (wherein R3 represents an alkyl, aryl or cycloalkyl group,
．． A homogeneous hydrocarbon solution containing a compound represented by the general formula AlRlX', -1 (where R
1 represents an alkyl, aryl or cycloalkyl group,
Xl represents a halogen atom, and l represents a number of 1≦l≦2. ) A method for polymerizing olefins, which comprises polymerizing olefins using a catalyst system comprising a combination of a hydrocarbon-insoluble solid obtained by treatment with an organic aluminum halide compound represented by the formula (2) and an organic aluminum compound. 2 General formula Mg (OR2) as a magnesium compound
2. The method for polymerizing olefins according to claim 1, wherein a compound represented by formula 2 is used, and a compound represented by the general formula T I(OR" ) 3X" is used as the titanium compound. 3. The method for polymerizing olefins according to claim 1 or 2, wherein magnesium diethylate is used as the magnesium compound and tri-n-butoxymonochlorotitanium is used as the titanium compound. 4 Claims 1 to 3 in which a compound selected from ethylaluminum dichloride, ethylaluminum sesquichloride, and diethylaluminium chloride is used as the organic aluminum halide compound
A method for polymerizing an olefin according to any one of paragraphs. 5. The amount of the magnesium compound, titanium compound, and organic aluminum halide compound used is such that the gram equivalent ratio satisfies the following: 1≦Mg/Ti≦4 X1+X2+X3 1≦≦4 0R2,000OR3 Items 1 to 4
A method for polymerizing an olefin according to any one of paragraphs. 6. Any one of claims 1 to 5, in which a magnesium compound and a titanium compound are mixed in the presence of alcohol to form a homogeneous solution, and then, after removing the alcohol, a hydrocarbon solvent is added to form a hydrocarbon solution. The method for polymerizing olefins described in . 7. The method for polymerizing olefins according to claim 6, wherein the alcohol is normal butanol. 8 The hydrocarbon solvent used to form a hydrocarbon solution is benzene,
A method for polymerizing an olefin according to any one of claims 1 to 7, which is toluene or xylene. 9 The organoaluminum compound has the general formula AlR%x:
Claims 1 to 8 which are compounds represented by P (wherein R4 represents an alkyl, aryl or cycloalkyl group, X4 represents a halogen atom, and p represents a number from 1 to 3) Any method for polymerizing an olefin. 10. The method for polymerizing olefins according to claim 9, wherein the organoaluminum compound is triethylaluminum. 11. The method for polymerizing olefins according to any one of claims 1 to 10, wherein the olefin to be polymerized is ethylene or a mixture of ethylene and other α-olefins.