JPH02269104A - Production of polyolefin - Google Patents

Abstract

PURPOSE:To obtain the subject polymer having large bulk density and good particle diameter distribution by using a catalyst comprising a solid product obtained by reacting Mg dialkoxide with Ti tetraalkoxide and with tetrahalogenated Ti stepwise and mixing with organic Al compound. CONSTITUTION:(A) Magnesium dialkoxide expressed by formula I (R<1> is 1-5C alkyl) is reacted with tetraalkoxytitanium expressed by formula II and reacted with tetrahalogenated titanium expressed by formula III (X<1> is halogen) and further, resultant solid substance is reacted with tetrahalogenated titanium expressed by formula IV (X<2> is halogen) to prepare a solid product. Then, a catalyst composed of two components as said product A and (B) an organic metal compound expressed by formula V (R<3> is 1-5C alkyl) is used to polymerize 2-8C alpha-olefin to afford the aimed polyolefin.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing polyolefin, and more specifically, it uses a catalyst comprising a specific activated titanium catalyst component and an organometallic compound to produce a polyolefin having a large bulk density and particle size. The present invention relates to a method for efficiently producing polyolefin with good distribution.

[Prior art and problems to be solved by the invention] Methods for producing polyolefins using catalysts consisting of solid catalyst components containing magnesium and titanium and organometallic compounds have been known. 46
-34098 publication.

JP-A-52-98076 or JP-A-5325
There is a method disclosed in Japanese Patent Application No. 80.

However, all of these have advantages and disadvantages, and in particular, there are various disadvantages such as a complicated catalyst preparation method, a low bulk density of the resulting polymer, a poor particle size distribution, and poor slurry properties.

The present invention is a patent characterized in that it provides a method for producing polyolefins that eliminates these problems.

[Means to solve the problem]

That is, the present invention provides (A) general formula Mg(OR')a [wherein R1 represents an alkyl group having 1 to 5 carbon atoms].

Magnesium dialkoxide represented by - general formula T
i (OR'')4 (wherein R2 represents an alkyl group having 1 to 5 carbon atoms) is reacted, and then, in the general formula TiX'aC, XI represents a halogen atom. ], and the resulting solid material is further reacted with tetrahalogenated titanium represented by the general formula T i solid product and (B) general formula /M!R33(
In the formula, Rff represents an alkyl group having 1 to 5 carbon atoms. The present invention provides a method for producing a polyolefin, which comprises polymerizing an α-olefin having 2 to 8 carbon atoms using a catalyst containing an organometallic compound represented by the following formula.

The magnesilano dialkoxide used in the present invention is represented by the general formula Mg(OR')z, where:
As mentioned above, R1 represents an alkyl group having 1 to 5 carbon atoms.

Examples of the magnesium dialkoxide include magnesium dimethoxide, magnesium jetoxide, and magnesium dialkoxide.

Examples include magnesium diptoxide. Moreover, although commercially available magnesium dialkoxides can be used, those produced by the reaction of metallic magnesium and alcohol may also be used.

In the present invention, the above-mentioned magnesium dialkoxide is reacted with tetraalkoxytitanium, and the tetraalkoxytitanium used here is a compound represented by the general formula T i (OR")4, where R2 has 1 carbon number. ~5 alkyl group.Specifically, (CH2O)4Ti, (
CzHsO)4Ti, (n-C1HtO)nTi, (n
C<HqO)aT! etc. can be given.

The conditions for reacting the above-mentioned magnesium dialkoxide with tetraalkoxytitanium are not particularly limited, and may be appropriately determined depending on various circumstances.

Usually, for 1 mole of magnesium dialkoxide,
Add 0.5 to 50 moles of tetraalkoxy titanium, preferably 1 to 20 moles, and heat at 20 to 200°C, preferably 5
The reaction may be carried out at 0 to 180°C for 5 minutes to 10 hours, preferably 20 minutes to 5 hours. Note that pentane and hexane are used in this reaction system.

Inert hydrocarbons such as heptane, octane, etc. can also be added as solvents.

Next, in the present invention, the homogeneous solution that is the above-mentioned reaction product is reacted with titanium tetrahalide.

This titanium tetrahalide has the general formula T as described above.
iX'a, where XI represents a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom; specifically, T i Cjl! 4. T i Bra.

An example is TiI4. These may be used alone or as a mixture. Among these, it is particularly preferable to use titanium tetrachloride (T i Cl 4 ).

The conditions for reacting the above-mentioned reaction product with the above-mentioned titanium tetrahalide are not particularly limited, but usually 0.1 to 20 mol of titanium tetrahalide is used per 1 mol of the above-mentioned magnesium dialkoxide. , preferably 1-1
Add in a range of 0 mol, 10 to 200°C, preferably 3
5 minutes to lO hours at 0 to 150"C, preferably 30
Allow to react for minutes to 5 hours. This reaction uses pentane and hexane as necessary.

It is also possible to use inert solvents such as heptane.

After the above-mentioned reaction is completed, a solid product is separated from the reaction solution, and the obtained product is washed with an inert solvent such as heptane as necessary to obtain a solid substance.

In the present invention, the solid material thus obtained is further reacted with titanium tetrahalide, and the obtained solid product is used as component (A) of the catalyst.

Here, titanium tetrahalide has the general formula TiX".

[In the formula, X2 represents a halogen atom. ], and may be the same as or different from the titanium tetrahalide represented by the general formula TiX' described above. Note that x2 is a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom, and examples of these titanium tetrahalides include T i Cff14.
Examples include T i Br, T i Ia, and the like. These may be used alone or as a mixture thereof. Among these, it is particularly preferable to use titanium tetrachloride (T iCl 4 ).

There are no particular restrictions on the conditions for reacting the above-mentioned solid substance with the titanium tetrahalide represented by the general formula TiX24, but usually 0.0% of the titanium tetrahalide is reacted with 1 mole of the above-mentioned magnesium dialkoxide. 1-2
0 mol, preferably in the range of 1 to 10 mol, lO to
200"C1 Preferably 5 minutes at 30-150°C
The reaction is allowed to proceed for 10 hours, preferably from 30 minutes to 5 hours. This reaction can also be carried out using an inert solvent such as pentane, hexane, heptane, etc., if necessary.

After the above reaction is completed, the solid product is separated from the reaction solution, thoroughly washed, and used as component (A) of the catalyst.

According to the present invention, (A), (
B) Polymerizing an olefin having 2 to 8 carbon atoms using a catalyst consisting of both components to produce a polyolefin.

In producing a polyolefin, a dispersion of the solid product as component (A) and an organometallic compound as component (B) are added to a reaction system, and then a raw material olefin is introduced into the system.

There are no particular restrictions on the polymerization method and conditions, and solution polymerization,
Both suspension polymerization and gas phase polymerization are possible, and both continuous polymerization and discontinuous polymerization are possible. Taking the case of solution polymerization or suspension polymerization as an example, the amount of the catalyst component to be added is from o,oot to 1.
0 mmol/l, preferably 0.005 to 0.5 mmol/l, and the ratio of component (B) to the titanium atoms in component (A) is 1 to 1000 (molar ratio), preferably 10 to 5.
00 (molar ratio). The pressure of the raw olefin in the reaction system is preferably normal pressure to 50 kg/cffl, and the reaction temperature is 30 kg/cffl.
-200°C, preferably 50-150°C.

Molecular weight adjustment during polymerization can be carried out by known means, such as hydrogen. The reaction time is 10 minutes to 1
The time may be appropriately selected from 0 hours, preferably from 30 minutes to 5 hours.

In the method of the present invention, an organometallic compound represented by the general formula Al2R'3 is used as the component (B) of the catalyst. In the formula, R3 is an alkyl group having 1 to 5 carbon atoms as described above. Specific examples include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisopropylaluminum, and triisobutylaluminum, and mixtures thereof are also suitable.

Furthermore, in the method of the present invention, when an electron-donating compound such as an ester is added during the polymerization reaction, a polymer with better stereoregularity can be obtained, especially in the case of propylene polymerization.

In the method of the present invention, a catalyst having 2 to 8 carbon atoms is used.
of α-olefin is polymerized. This α-olefin has the general formula R' CH═CHz [wherein R4 represents hydrogen or an alkyl group having 1 to 6 carbon atoms]. ],
For example, ethylene and propylene.

Examples include linear monoolefins such as butene-1, hexene-1, and octene-1, branched monoolefins such as 4-methyl-pentene-1, dienes such as butadiene, and various others. are these homopolymerizations,
Alternatively, it can be effectively used for copolymerization of various α-olefins.

〔Effect of the invention〕

According to the method of the present invention, since the activity of the catalyst used is extremely high, it is possible to omit the catalyst removal step (so-called deashing step). In addition, since the obtained polyolefin has a high bulk density, production efficiency is high.1. Moreover, since the particle size distribution is sharp, the drying operation is easy, energy consumption can be saved, and handling is very easy.

Next, examples of the present invention will be shown together with comparative examples. All operations in the following Examples and Comparative Examples were performed under an argon stream.

Example (1) Preparation of solid catalyst component In a 300 d three-necked flask, 3 g (26 mmol) of magnesium jetoxide and 1 mol of tetra-n-butoxytitanium were added.
After adding 7 g (52 mmol), the temperature was raised to 140°C for 2 hours. After the reaction was completed, it was cooled to 60°C.
100mj of n-hexane! added. Then, 19 g (100 mmol) of titanium tetrachloride was added dropwise to the system over 30 minutes. At the same time as this dropwise addition was started, white solid was observed to precipitate. After the dropwise addition was completed, the reaction was carried out under reflux for 3 hours.

After the reaction was completed, the temperature was returned to room temperature, the mixture was allowed to stand, the supernatant liquid was extracted, and 100 ml of n-hexane was added, stirred, and allowed to stand still.

I drained the liquid. Repeat the operations of standing still, removing the supernatant liquid, adding n-hexane, stirring, standing still, and removing the liquid 5 times.
As a result, a solid material was obtained. When this solid substance was measured using a colorimetric method, the amount of titanium supported was 158■-T.
i/g-carrier.

Titanium tetrachloride was added to the solid material obtained as above.
An amount equivalent to 5 moles of titanium was added to 1 mole of magnesium in 3 g of the above-mentioned magnesium jetoxide at 60°C.
and the reaction was carried out under reflux for 3 hours.

After the reaction is complete, return to room temperature, leave to stand, and remove the supernatant.
100 ml of n-hexane was newly added, and the mixture was stirred, allowed to stand, and the liquid was drained. Repeat the operations of standing still, removing the supernatant liquid, adding n-hexane, stirring, standing still, and removing the liquid 5 times.
A solid product was obtained. When this solid product was measured using a colorimetric method, the amount of titanium supported was 53 mg-Ti7g-
It was a carrier.

(2) Polymerization of ethylene 40 ml of n-hexane in a stainless steel autoclave
0m1. 2 mmol of triisobutylaluminum (TIBA) and 0.01 mmol of the solid product obtained in (1) above as titanium were added, and the temperature was raised to 80"C. Next, 3 kg/cnf of hydrogen was added, and 5 kg/ct of ethylene was added. and total pressure of 9.3 kg/c+f
1-G, and polymerization was carried out for 1 hour while introducing ethylene to maintain this total pressure. As a result, 167 g of white polyethylene was obtained. The bulk density of this polyethylene is 0.26 g/cyd, and the M I is 3.0.
g/10 minutes. Furthermore, the activity of the catalyst used here was 349 kg per hour per 1 g of titanium.

Comparative Example 1 (1) Production of solid catalyst component A solid product was obtained by performing the same treatment as in Example 1 (1) except that tetra-n-butoxytitanium was not added in Example 1 (1). . The amount of titanium supported in this product was 85 mg/7 g of Ti/carrier.

(2) Polymerization of ethylene In Example 1 (2), the solid product obtained in Comparative Example 1 (1) above was used instead of the solid product obtained in Example 1 (1). Polymerization was carried out in the same manner as in Example 1 (2). As a result, 78 g of white polyethylene was obtained. The bulk density of this polyethylene is 0.2
6g/c1a, Ml was 1.9g/10min.

Example 2 (1) Production of solid catalyst component The same operation as in Example 1 (1) was performed except that tetraisopropoxy titanium was used instead of tetra-n-butoxy titanium in Example 1 (1). , a solid material (titanium supported it 143 mg-Ti/g-support) was obtained, and a solid product was also obtained. The amount of titanium supported on this product was 58 mg-Ti/g Ju.

(2) Polymerization of ethylene! 400 d of n-hexane and 0.01 mmol of l-lynebutylaluminum were added to a stainless steel autoclave, and the temperature was raised to 80°C. Then hydrogen 3 kg/cal, ethylene 5 k
Add g/c+fl, total pressure @9. 3 kg/c
+ll-G, and polymerization was carried out at 80°C for 1 hour while introducing ethylene to maintain this total pressure. As a result, 178 g of white polyethylene was obtained. The bulk density of this polyethylene is 0. 2 9 g/c
J, Mr was 2.7 g/10 minutes. In addition, the activity of the catalyst used here was titanium Ig, 371 per hour.
It was kg.

Example 3 (1) Production of solid catalyst component The same procedure was carried out as in Example 1 (1) except that 34 g (104 mmol) of tetra-n-butoxytitanium and 35 g (185 mmol) of titanium tetrachloride used initially were added. The same operation as in Example 1 (1) was carried out to obtain a solid material (amount of titanium supported: 137 cm - 7 g of Ti - carrier), and further a solid product was obtained. The amount of titanium supported in this product is 50■-T i /
g-carrier.

(2) Polymerization of ethylene In Example 1 (2), the solid product obtained in Example 3 (1) above was used instead of the solid product obtained in Example 1 (1). Polymerization was carried out in the same manner as in Example 1 (2). As a result, 147 g of white polyethylene was obtained. The bulk density of this polyethylene is 0
．． 27g/cj MI was 3.2g/10min.

Example 4 (Polymerization of propylene) 400 d of n-hebutane, dried in a stainless steel autoclave of 11,) 2.0 mmol of ethylaluminum, 0.6 mmol of p-)methyl ruylate and Example 1
0.02 mmol of titanium was added to the solid product obtained in (1), and 0.2 kg of zero-order hydrogen was heated to 70°C.
/cffl and further increase the total pressure to 7 kg/cf with propylene.
After completion of the polymerization reaction, which was carried out for 2 hours while maintaining the temperature at c+fl-G, the product was filtered at 70°C to remove the solvent and dried to obtain 172 g of polypropylene. The residual amount of this polypropylene extracted with boiling n-hebutane is 83.
5%, while the polymerization solvent is more soluble than the polymer 13.
5g was recovered. In addition, the activity of the catalyst used here is
1 g of titanium was 179 kg per 2 hours.

Comparative Example 2 (1) Production of solid catalyst component In a 300 m three-necked flask, 3 g (26 mmol) of magnesium jetoxide, 17 g (52 mmol) of tetra-n-butoxytitanium, and 17.9 g (52 mmol) of dichlorodibutoxytitanium were added. and 100 d of a petroleum fraction with a boiling point range of 130 to 160"C were added at the same time, and the reaction was carried out under reflux for 7 hours. After the reaction was completed, the resulting precipitate was decanted and washed with 100 d of n-hexane for 5 hours. A solid product was obtained by repeating the process several times.The amount of titanium supported on this solid product was 140 μ-T i /g-support.

(2) Polymerization of ethylene In Example 1 (2), the solid product obtained in Comparative Example 2 (1) above was used instead of the solid product obtained in Example 1 (1). Polymerization was carried out in the same manner as in Example 1 (2). As a result, 20 g of white polyethylene was obtained. The bulk density of this polyethylene is 0.1
It was 5g/d. The activity of the catalyst used here was 10.4 cg per hour per 1 g of titanium.

[Brief explanation of drawings]

FIG. 1 is a drawing showing the steps for preparing a catalyst used in the method of the present invention. Engraving of the drawings (no changes to the contents) Drawing procedure amendment (side May 1990)

Claims (1)

[Claims] (1) (A) General formula Mg(OR^1)_2 [wherein, R^
1 represents an alkyl group having 1 to 5 carbon atoms. ] to the magnesium dialkoxide represented by the general formula Ti (OR^2
)_4 [In the formula, R^2 represents an alkyl group having 1 to 5 carbon atoms. ] is reacted with tetraalkoxytitanium represented by the general formula TiX^1_4 [wherein X^1 represents a halogen atom]. ] is reacted with titanium tetrahalide represented by the general formula TiX.
^2_4 [In the formula, X^2 represents a halogen atom. ] and (B) a solid product obtained by reacting titanium tetrahalide represented by the general formula AlR^3_3 [wherein,
R^3 represents an alkyl group having 1 to 5 carbon atoms. ] using a catalyst containing an organometallic compound represented by
A method for producing a polyolefin, which comprises polymerizing α-olefins of ~8.