JPH03271295A - Production of aluminoxane - Google Patents

Abstract

PURPOSE:To obtain the uniform title compound having high activity and excellent storage stability and useful as a catalytic component for producing an olefin based polymer, etc., by carrying out the reaction of organoaluminum compound with water in the presence of a monovalent alcohol when or after an organoaluminum compound is reacted with water. CONSTITUTION:When (A) an organoaluminum compound (preferably trimethylaluminum) is reacted with (B) water (e.g. solvent saturated water), preferably in a solvent such as hexane, the reaction is carried out in the presence of (C) a monovalent alcohol (preferably triphenylmethanol) or the component A is reacted with the component B, preferably in a solvent and then the resultant compound is subjected to catalytic reaction with the component C to provide the aimed compound. Furthermore, when the above-mentioned reaction is carried out in the presence of the component C, the component C is preferably added thereto at an amount of 0.01-0.5 times by mol based on the component A and when the above mentioned reaction product is subjected to catalytic reaction with the component C, the component C is preferably added thereto at an amount of 0.01-0.3 times by mol based on the compound A.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing aluminoxane, which is suitably used as a catalyst component for producing olefin polymers and styrene polymers. This invention relates to a method for producing uniform aluminoxane with excellent storage stability.

[Prior art and problems to be solved by the invention] Conventionally, olefins and styrene are polymerized in the presence of a catalyst.
In producing olefin polymers or styrene polymers, a method is known in which a reaction product of a transition metal compound and aluminoxane is used as a catalyst (JP-A-62
-36390 publication.

Publication No. 59-95292, etc.).

By the way, al[tuxane compounds are generally used after being dissolved in an aromatic hydrocarbon solvent such as toluene, but if this solution is stored for a long period of time, viscous gel-like aluminoxane (aluminoxane solid particles) will precipitate.
There were problems such as gel-like particles adhering to the walls of the storage container and the aluminoxane concentration in the solution changing.

Therefore, as a method to solve this problem, a method of adding alkyl aluminum to this solution (Japanese Patent Application Laid-Open No. 1-25868
Publication No. 6) has been proposed.

According to this method, a uniform aluminoxane solution without gel components can be obtained, but there are problems in that the addition of alkyl aluminum changes the polymerization activity of the catalyst and also limits the physical properties of the resulting polymer. Ta.

[Means to solve the problem]

As a result of intensive research to solve these problems, the present inventors found that by making a monohydric alcohol present in the reaction system during or after producing aluminoxane from an organoaluminum compound and water, discovered that it is possible to produce aluminoxane free from such problems, and based on this knowledge, the present invention was completed.

That is, the present invention provides a method for producing aluminoxane, which is characterized in that a monohydric alcohol is present in the reaction system during or after producing aluminoxane from an organoaluminum compound and water.

In other words, the present invention involves (1) making a monohydric alcohol exist (coexist) in the reaction system when producing aluminoxane from an organoaluminum compound and water, or (2) after producing aluminoxane from an organoaluminum compound and water. , which is characterized by adding a -hydric alcohol thereto and causing a catalytic reaction.

The organoaluminum compound used in the present invention is not particularly limited; -10 alkyl group, p+, Rz,
R3 may be the same or different. ] Alkylaluminum compounds represented by the following are preferred.

Specifically, such aluminum alkyl compounds include, in addition to trialkylaluminum such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, diethylaluminum hydride,
Examples include diisobutylaluminum hydride.

Among the organoaluminum compounds mentioned above, trialkylaluminum is preferred, and trimethylaluminum is particularly preferred.

On the other hand, as the water to be reacted with the organoaluminum compound, in addition to ordinary water, ice, and steam, various water-containing compounds,
For example, it contains solvent-saturated water, water adsorbed by inorganic substances, crystal water containing metal salts such as copper sulfate pentahydrate (CuSOn.5H20), and the like.

The present invention is characterized in that a monohydric alcohol is present in the reaction system when producing aluminoxane from the above organoaluminum compound and water, or after producing aluminoxane from the above organoaluminum compound and water. be.

Specific examples of the monohydric alcohol used in the present invention include alcohols having a linear alkyl group such as methanol, ethanol, propatool, and butanol; branched alkyls such as isopropyl alcohol, isobutanol, and tertiary-butanol; Alcohols having a phenyl group such as phenol, benzhydrol and triphenylmethanol; alcohols having a cyclic alkyl group such as cyclohexanol and cycloheptatool; and the like.

In the present invention, as the monohydric alcohol, alcohols having a branched alkyl group and alcohols having a bulky group such as triphenylmethanol are preferable because they have a high aluminoxane yield.

In the present invention, the above-mentioned organoaluminum compound is used.

Water and a monohydric alcohol are brought into contact with each other, and examples of contact methods include the following three methods i) to 1ii).

i) A method in which water and alcohol are dissolved in an organic solvent and an organic aluminum compound is added thereto.

ii) A method in which an organoaluminum compound and an alcohol are reacted in an organic solvent, and water is added to the reaction.

ii) A method in which an organoaluminum compound and water are reacted in an organic solvent, and alcohol is added to the reaction product (ie, aluminoxane).

Methods i) and ii) described above are used when producing aluminoxane from an organoaluminum compound and water.
This is included in the method of making a monohydric alcohol exist (coexist) in the reaction system, and the method 1ii) is as follows: After producing aluminoxane from the organoaluminum compound and water, This is a method of adding and causing a catalytic reaction.

Among these methods, method 1) is preferred because it also improves the aluminoxane yield.

Although the above reaction proceeds without a solvent, it is preferably carried out in a solvent.

Examples of the organic solvent used here include aliphatic hydrocarbons and aromatic hydrocarbons, specifically aliphatic hydrocarbons such as hexane, heptane, and decane, and hexane, toluene, p-xylene, m-xylene, - Aromatic hydrocarbons such as xylene, ethylbenzene, propylbenzene, and cumene.

In addition, when the alcohol is added during the reaction between the organoaluminum compound and water (in the case of methods i) and ii) above), the amount of alcohol to be added is 0.0% relative to the organoaluminum compound.
It is good to add 0.001 to 0.7 times the mole, preferably 0.01 to 085 times the mole.

If the amount of alcohol added here is less than 0.001 times the mole, it is difficult to notice the effect, whereas if it is used in excess of 0.7 times the mole, the alkyl group, which is important as a catalyst component, will react with the alcohol. , since the residual amount of alkyl groups decreases, the effectiveness as a catalyst component tends to decrease.

On the other hand, when the organoaluminum compound is added after the reaction with water (in the case of the method in the above corner), the R/i ratio (amount) is lower than in the above case, so the aluminum atoms in the aluminoxane produced are On the other hand, 0.0001 to 0.5
It is good to add twice the mole, preferably o, ooi to 0.3 times the mole.

If the amount of alcohol added here is less than 0.0001 times the mole, it is difficult to notice the effect, whereas if it is used in excess of 0.5 times the mole, the alkyl group, which is important as a catalyst component, will react with the alcohol. , since the residual amount of alkyl groups decreases, the effectiveness as a catalyst component tends to decrease.

In the case of the above-mentioned methods i) and i;), the reaction conditions are as follows:
It may be carried out under the same conditions as those described in Japanese Patent Application Laid-open No. 2-36390, Japanese Patent Application Laid-open No. 59-95292, and Japanese Patent Application Laid-open No. 64-16803.

On the other hand, in the case of method tii), after preparing aluminoxane under normal conditions, the -hydric alcohol is heated at a temperature of 70°C or less, more specifically, usually from O''C to 70°C, preferably from 20°C to 50°C. Preferably, the alcohol is added in liquid form, either directly or as a dilute solution, at a temperature of .degree.

The aluminoxane thus obtained may be used as it is, or after being concentrated or dried.

The concentration or drying may be carried out at a temperature of 0 to 200'' C1, preferably 10°C to 150°C, and under atmospheric pressure or reduced pressure.

Concentrating or drying at a temperature exceeding 200°C is not preferable because thermal decomposition of the aluminoxane itself occurs.

This S condensation treatment yields highly pure aluminoxane.

The aluminoxane thus obtained is used in the reaction in a form dissolved in an aromatic hydrocarbon solvent such as toluene.

The aluminoxane obtained in the above manner is combined with a transition metal compound to form an olefin polymer such as polyethylene, atactic polypropylene, isotactic polypropylene, polybutene-1, poly4-methylpentene-1, etc. It can be used as a propylene copolymer or the like, or a styrene polymer, specifically a styrenic polymer having a syndiotactic structure, or as a catalyst component for low polymerization of propylene.

In addition, here, as a transition metal compound, the periodic table No.
The metal may be selected from group (2) transition metals depending on the type of the desired polymer. Further, reaction conditions such as the ratio of the transition metal in the transition metal compound to aluminum in the aluminoxane and the polymerization temperature may be carried out under normal conditions.

〔Example〕

Next, the present invention will be explained by examples.

Example 1 (1) Preparation of aluminoxane 100 d of toluene, copper sulfate pentahydrate (CuSO4.5820
) Add 17.7 g (71 mmol) and 3.3 d (36 ma+ol) of isobutanol, and heat at 5°C.
Trimethylaluminum (TMA) 9.6
g (133 mn+ol) was added dropwise. At this time, approximately 36 m5+o1 of methane gas was generated, indicating that trimethylaluminum and isobutanol were reacting at a ratio of 1:1.

Thereafter, the reaction was carried out at 40''C for 8 hours to remove solid components, and the resulting solution was stirred at 50''C while toluene was distilled off. Once the solution has been removed,
The temperature was raised to 110°C and drying was performed until no distillate remained.

As a result, the contact product aluminoxane was 4.64
I got g.

20jli of this! The solution was dissolved in toluene and allowed to stand for one month under a dry nitrogen atmosphere, but no gel-like precipitate was formed.

(2) Polymerization of ethylene In a nitrogen-substituted autoclave with an internal volume of 11, add 400 d of toluene, 1 mol of the aluminoxane obtained in (1) above as an aluminum atom, and 5 μm O1 of biscyclopentagenylzirconium dichloride as a transition metal compound. After each addition, the temperature was raised to 80°C.

Next, ethylene was continuously introduced into the autoclave,
The polymerization reaction was carried out at 8 kg/cd for 1 hour. After the reaction, methanol was added to decompose the catalyst and then dried to obtain 142 g of polyethylene.

The polymerization activity of the catalyst was 312) cg/g-Zr.

(3) Polymerization of styrene Into a nitrogen-substituted autoclave with an internal volume of 1, add 4 mmo of styrene 4001d and lyoisobutylaluminum.
1, 4 mmol of the aluminoxane obtained in the above (1) as an aluminum atom and 20 μmol of pentamethylcyclopentadienyl titanium trimethoxide as a transition metal compound were added, and a polymerization reaction was carried out at 70°C for 1 hour. After the reaction was completed, the product was washed with a hydrochloric acid/methanol mixture to separate and remove the catalyst component, and dried to obtain 102.1 g of a polymer.

The polymerization activity of the catalyst was 107 kg/g-Ti. The racemic pentad syndiotacticity of this polymer was 97% by 13C-NMR measurement.

These results are shown in Table 1.

Comparative Example 1 (1) Preparation of aluminoxane Algotuxane was synthesized in the same manner as in Example 1 (1) except that isobutanol was not used in Example 1 (1). A solid component was obtained.

When this was dissolved in 20111 toluene and left for one month under a dry nitrogen atmosphere, a gel-like precipitate formed.

(2) Polymerization of ethylene In Example 1 (2), the above (
Ethylene polymerization was carried out in the same manner as in Example 1 (2) except that the aluminoxane obtained in 1) was used.
130 g of polyethylene was obtained. The polymerization activity of the catalyst is 286
kg/g-Zr.

(3) Polymerization of styrene Example 1 (in Example 3), the above (
Ethylene polymerization was carried out in the same manner as in Example 1 (3) except that the aluminoxane obtained in 1) was used to obtain 91.4 g of syndiotactic polystyrene. The polymerization activity of the catalyst was 95) cg/g-Ti.

These results are shown in Table 1.

Example 2 (1) Preparation of methylaluminoxane In Example 1 (1), instead of isobutanol,
Example 1 except that tertiary butanol was used.
Produce aluminoxane in the same manner as in (1), and
．． 3 g of solid component (methylaluminoxane) was obtained.

This was dissolved in 20 d of toluene and left in a dry nitrogen atmosphere for one month, but no gel precipitate was formed.

(2) Polymerization of ethylene In Example 1 (2), the above (
Ethylene polymerization was carried out in the same manner as in Example 1 (2) except that the aluminoxane obtained in 1) was used. The polymerization activity of the catalyst was 321 kg/g-Zr.

(3) Polymerization of styrene In Example 1 (3), the above (
Styrene polymerization was carried out in the same manner as in Example 1 (3) except that the aluminoxane obtained in 1) was used. The polymerization activity of the catalyst was 108 kg/g-Ti.

These results are shown in Table 1.

Examples 3 to 8 Various aluminoxanes were obtained in the same manner as in Example 1 (1), except that the type and amount of alcohol used were changed to the conditions shown in Table 1. .

These were dissolved in 20111 toluene and left in a dry nitrogen atmosphere for one month, but no gel precipitates were formed in either case.

Hereinafter, Example 1 except that this aluminoxane was used
Ethylene and styrene were polymerized in the same manner as (2) and Example 1 (3), respectively.

These results are shown in Table 1.

Example 9 (1) Preparation of aluminoxane The methylaluminoxane obtained in Comparative Example 1 (1) was used as an aluminum atom and 30IIIlo1 was added with isobutanol 0.6I111 (6.5 mmof) at room temperature.
) was added to obtain a homogeneous solution.

This was left for one month under a dry nitrogen atmosphere, but no gel precipitate was formed.

(2) In ethylene polymerization example work (2), the above (
Ethylene polymerization was carried out in the same manner as in Example 1 (2) except that the aluminoxane obtained in 1) was used.

The polymerization activity of the catalyst was 311 kg/g-Zr.

(3) Polymerization of styrene In Example 1 (3), the above (
Styrene polymerization was carried out in the same manner as in Example 1(3) except that the aluminoxane obtained in 1) was used.

The polymerization activity of the catalyst was 106 kg/g Ti.

〔Effect of the invention〕

According to the method of the present invention, it is possible to obtain a gel-free homogeneous altoxane solution.

Therefore, the storage stability is extremely poor even without adding alkyl aluminum or the like as in the past, and there is no adverse effect due to the addition of alkyl aluminium.

Further, according to the method of the present invention, not only the yield of aluminoxane is excellent, but also the obtained aluminoxane has high catalytic activity.

Therefore, the present invention can be effectively utilized for producing a catalyst acid component for producing olefin polymers and styrene polymers.

Claims (1)

[Claims] (1) A method for producing aluminoxane, which comprises causing a monohydric alcohol to be present in the reaction system during or after producing aluminoxane from an organoaluminum compound and water.