JP2764106B2 - Polymerization method - Google Patents

Description

The present invention relates to a method for polymerizing an olefin. More specifically, the present invention relates to a method for polymerizing an olefin using a catalyst comprising a transition metal catalyst and an organic aluminum.

(Prior art)

Conventionally, catalysts combining many kinds of transition metal compounds and organometallic compounds are known, but recently, as catalysts having unprecedented characteristics, dicyclopentadienyl titanium dichloride, dicyclopentadienyl titanium dimethyl, Dicyclopentadienyl zirconium dichloride, dicyclopentadienyl zirconium dimethyl, dicyclopentadienyl hafnium dichloride,
It has been proposed that an olefin can be polymerized by using a homogeneous catalyst comprising a transition metal compound such as dicyclopentadienylhafnium dimethyl and aluminoxane (Japanese Patent Application Laid-Open No. 58-19303).

[Problems to be solved by the invention]

In the above-mentioned method, an extremely high polymerization activity per transition metal compound can be obtained for olefin polymerization. However, the aluminoxane used here has a very high reactivity and is inactivated by the incorporation of a small amount of water, and therefore has a problem in handling such as difficulty in long-term storage.

The catalyst may be prepared by mixing the transition metal compound and the aluminoxane. However, after preparing the catalyst, it is necessary to promptly subject the mixed solution to polymerization. It is known that if for some reason, after the preparation of the catalyst, the mixed solution cannot be promptly subjected to polymerization, the activity of the catalyst is rapidly reduced and deactivated. Therefore, there is a need for a catalyst that is stable and easy to handle.

[Means for solving the problem]

The present inventors have conducted intensive studies to solve the above problems, and found that a catalyst system comprising a combination of a transition metal compound, an alkylaluminum, and water shows polymerizability to an olefin, and has a storage stability. The present invention was found to be easy to handle and completed the present invention.

That is, the present invention provides an alkyl group, an aryl group, a π-enyl and a hydrocarbon group selected from π-cyclopentadienyl group as a ligand of the group IVA transition metal compound of Periodic Table IV and trialkylaluminum. An olefin polymerization method characterized by using, as a catalyst, a reaction mixture obtained by reacting a mixture with water.

The transition metal compound belonging to Group IVA of the periodic table IV used in the present invention is a titanium, zirconium or hafnium compound having at least one hydrocarbon group as a ligand. Here, the hydrocarbon group is selected from an alkyl group, an aryl group, π-enyl and π-cyclopentadienyl group.

Specifically, tetrabenzyl titanium (IV), bis (η-
Cyclopentadienyl) titanium (II), dichloro (η-
Cyclopentadienyl) titanium (III), chlorobis (η-cyclopentadienyl) titanium (III), trichloro ((η-cyclopentadienyl) titanium (IV), dichlorobis (η-cyclopentadienyl) titanium ( I
V), dimethylbis (η-cyclopentadienyl) titanium (IV), bis (phenylethyl) bis (η-cyclopentadienyl) titanium (IV), bis (η-cyclopentadienyl) titanium (IV) , Tetrabenzylzirconium, tetrakisarylzirconium (IV), trichloro (η-cyclopentadienyl) zirconium (IV), dichlorobis (η-cyclopentadienyl) zirconium (IV), dimethylbis (η-cyclopentadienyl) Zirconium (IV), chlorobis (η-cyclopentadienyl) zirconium (IV) oxide, dihydridobis (η-cyclopentadienyl) zirconium (IV), tetrakisallylhafnium (IV), dichlorobis (η-
Cyclopentadienyl) hafnium (IV), dimethylbis (η-cyclopentadienyl) hafnium (IV) and the like.

General formula trialkylaluminum to be used in the present invention, a trialkylaluminum represented by AlR _3, specifically, trimethylaluminum, triethylaluminum, tri-propyl aluminum, tri-n- butylaluminum, triiso - butyl Aluminum, trihexyl aluminum, a mixture thereof, and the like can be given.

In the present invention, a catalyst is obtained by reacting a mixture of a transition metal compound and a trialkylaluminum with water in the presence or absence of a solvent inert to these compounds. There is no particular limitation on the method for producing the catalyst component,
For example, a method in which a transition metal compound and a trialkylaluminum represented by the general formula, AlR ₃ in an organic solvent are directly reacted by dissolving water in a liquid, solid, steam or a solvent, or a compound containing adsorbed water or water of crystallization , For example, copper sulfate hydrate,
A method in which aluminum sulfate hydrate or iron sulfate hydrate is produced by reacting a transition metal compound with a trialkylaluminum in an organic solvent.

Such solvents include hydrocarbon solvents.
Specific examples of the hydrocarbon solvent include hydrocarbons such as butane, pentane, hexane, heptane, octane, decane, dodecane, cyclohexane, cyclooctane, benzene, toluene, xylene and petroleum fractions such as gasoline, kerosene, and light oil. Used. The reaction ratio of the transition metal compound, the organoaluminum compound and water used in this reaction is preferably such that the ratio of aluminum to the transition metal atom is in the range of 1:10 to 1:10 ^-8 . Further, the proportion of water used is suitably such that the ratio of the total number of moles of aluminum and transition metal atoms to the number of moles of water is in the range of 1: 1 to 2: 1.

In the polymerization reaction, the obtained product may be used as it is. However, the product may be further purified and used with little solvent or unreacted trialkylaluminum, and in some cases, it is preferable.

In the present invention, specific examples of the olefin used for the polymerization include ethylene, propylene, 1-butene, and 4-olefin.
Methyl-1-pentene, 1-hexene, 1-octene,
Α-olefins such as 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, styrene, methylstyrene, α-vinylnaphthalene, β
-Vinyl naphthalene and the like. When a copolymer is produced, two or more of these components can be used as a mixture.

In the polymerization method of the present invention, a suspension polymerization method, a bulk polymerization method, and a gas phase polymerization method are employed for olefin polymerization. In the suspension polymerization method, a hydrocarbon medium is used.Specific examples of the hydrocarbon medium include butane, pentane, hexane, heptane, octane, decane, dodecane, cyclohexane, cyclooctane, benzene, toluene, and xylene. Hydrocarbons, petroleum fractions such as gasoline, kerosene, and light oil are used. When polymerizing in a liquid phase, including a bulk polymerization method using a liquid monomer as a medium, usually 10 ^-4 to 10 ^-1 mo
It is preferred to use an aluminum compound concentration of l /.

As the polymerization temperature and the polymerization pressure, general conditions used in a known method are used, and the temperature is in a temperature range of -50 to 300 ° C, preferably -20 to 200 ° C. The polymerization pressure is from normal pressure to 50 kg / cm ² · gauge. The average molecular weight of the resulting polymer can be adjusted in a known manner by adding hydrogen and / or adjusting the polymerization temperature.

〔Example〕

 Hereinafter, the present invention will be further described with reference to examples.

Example 1 (a) Preparation of Catalyst Component A sufficiently dry, nitrogen-replaced, Pyrex glass vessel having an internal volume of 50 ml was charged with 21 mmol of trimethylaluminum (1.38 mol / concentration) diluted with toluene, and further charged.
At 25 ° C., ferrous heptahydrate _{(Fe 2 (SO 4) 3} 7H 2 O) sulphate 0.91g
(2.7 mmol) was added. Further, 50 mg of dichlorobis (η-cyclopentadienyl) zirconium (IV) (0.14 mm
ol), the temperature of the solution was raised to 50 ° C., and the reaction was carried out for 4 hours. After the temperature was returned to room temperature, insolubles were removed to obtain a catalyst component.

(B) Polymerization of Styrene 25 ml of styrene was inserted into a 300 ml-volume Pyrex glass autoclave which had been sufficiently dried and purged with nitrogen, and the above-mentioned catalyst component (a) (0.5% in terms of zirconium atoms) was added.
017 mmol) and stirred at room temperature. The polymerization was continued at 25 ° C. for 2 hours. The polymerization was stopped by adding a small amount of methanol to the autoclave, and the content was poured into 500 ml of acidic hydrochloric acid methanol, and the insoluble matter was filtered to obtain white powdery polystyrene.

The yield of this powdered polystyrene is 0.42 g, and thus the activity is 12.4 kg / mol · Zr · hr.

Example 2 In Example 1, except that ethylene was used instead of styrene, ethylene was polymerized by the same operation as in (b) of Example 1. That is, the catalyst (a) (0.045 mmol in terms of zirconium atom) was charged into 660 ml of toluene in a SUS-32 autoclave having an internal volume of 2 which had been sufficiently dried and replaced with nitrogen. The contents of the autoclave were heated and polymerization was continued for 1 hour while charging ethylene at 50 ° C. to maintain a polymerization pressure of 5 kg / cm ² gauge. The autoclave was cooled, unreacted ethylene was purged, and the contents were poured into 1 of methanol, and insolubles were filtered to obtain a white powdery polyethylene.

The yield of this powdered polyethylene is 14.8 g and therefore the activity is 329 kg / mol · Zr · hr.

Example 3 (a) Adjustment of catalyst component In Example 1, dichlorobis (η-cyclopentadienyl) titanium (IV) 6.6 m was used as a transition metal catalyst.
A catalyst component was synthesized in the same manner as in Example-1 (a), except that g (0.027 mmol) was used in place of dichlorobis (η-cyclopentadienyl) zirconium (IV).

(B) Polymerization of styrene 25 ml of styrene was inserted into a 300 ml-volume Pyrex glass autoclave which had been sufficiently dried and purged with nitrogen, and the above-mentioned catalyst component (a) (0.000 in terms of titanium atom) was added.
(66 mmol) and stirred at room temperature. 2 polymerization at 25 ° C
Continued for hours. The polymerization was stopped by adding a small amount of methanol to the autoclave, and the content was poured into 500 ml of acidic hydrochloric acid methanol, and the insoluble matter was filtered to obtain white powdery polystyrene.

The yield of this powdered polystyrene is 0.28 g, therefore the activity is 21.2 kg / mol · Ti · hr.

Example-4 In Example 3, except that ethylene was used instead of styrene, ethylene was polymerized by the same operation as in (b) of Example-3. That is, the catalyst component (a) (0.009 mmol in terms of titanium atom) was charged into 660 ml of toluene in a SUS-32 autoclave having an internal volume of 2 which was sufficiently dried and replaced with nitrogen. The contents of the autoclave were heated and polymerization was continued for 1 hour while charging ethylene at 35 ° C. to maintain the polymerization pressure at 5 kg / cm ² gauge. The autoclave was cooled, unreacted ethylene was purged, and the contents were poured into 1 of methanol, and insolubles were filtered to obtain a white powdery polyethylene.

The yield of this powdered polyethylene is 7.1 g, therefore the activity is 788 kg / molTi · hr.

Example-5 The catalyst component obtained in (a) of Example-1 was stored at 25 ° C for 1 day, and then used in the same manner as in Example-2 except that it was used for polymerization. As a result, the yield of polyethylene was 15.1 g. And the activity is 335 kg
/ mol · Zr · hr.

Comparative Example-1 (a) Adjustment of catalyst component A catalyst component was synthesized in the same manner as in Example-1 (a) except that no transition metal catalyst component was used in Example-1.

(B) Polymerization of Ethylene Polymerization of ethylene was performed in the same manner as in (b) of Example-1. That is, the catalyst component (a) (7.7 mmo in terms of aluminum atom) was sufficiently dried and replaced with 660 ml of toluene in an autoclave made of SUS-32 having an internal volume of 2 and purged with nitrogen.
l) was charged. Heat the contents of the autoclave to 5
The polymerization was continued for 1 hour while charging ethylene at 0 ° C. to maintain the polymerization pressure at 5 kg / cm ² gauge. Cool the autoclave and purge unreacted ethylene to
Of methanol. No polyethylene was obtained.

Comparative Example 2 (a) Adjustment of Catalyst Component A catalyst component was synthesized in the same manner as in Example 1 (a) except that trimethylaluminum was not used.

(B) Polymerization of Ethylene Polymerization of ethylene was performed in the same manner as in (b) of Example-1. That is, the catalyst component (a) (0.045 m 2 in terms of zirconium atoms) was thoroughly dissolved in 660 ml of toluene in a SUS-32 autoclave having an internal volume of 2 and purged with nitrogen.
mol). The contents of the autoclave were heated and polymerization was continued for 1 hour while charging ethylene at 50 ° C. to maintain a polymerization pressure of 5 kg / cm ² gauge. The autoclave was cooled, the unreacted ethylene was purged, and the contents were poured into 1 part of methanol. No polyethylene was obtained.

Reference Example 1 As a transition metal compound, 0.032 mmol of dichlorobis (η-cyclopentadienyl) zirconium (IV) (hereinafter abbreviated as CpZrCl ₂ ) and 4.8 mmol of methylaluminoxane synthesized by the method of Comparative Example 1 were used. Others were polymerized in the same manner as in Example 2 to obtain 13.6 g of polyethylene.
The activity was 425 kg / mol · Zr · hr.

Comparative Example-3 CpZrCl ₂ and methylaluminoxane were mixed in 10 ml of toluene for 2 minutes.
After mixing at 5 ° C. for 1 hour, polymerization was carried out in the same manner as in Reference Example 1 except that ethylene was polymerized to obtain 5.6 g of polyethylene.
The activity was 175 kg / mol · Zr · hr.

Polyethylene except for using CpTiCl ₂ changed to Comparative Example -4 CpZrCl ₂ is was in the same manner as in Comparative Example 3 was not obtained at all.

〔The invention's effect〕

The catalyst component used in the method of the present invention can be easily synthesized, is stable and easy to handle, can obtain a polymer with high activity, and has high industrial value.

[Brief description of the drawings]

FIG. 1 is a flow diagram to help explain the method of the present invention.

Claims (1)

(57) [Claims] A mixture of a transition metal compound of Group IVA of the Periodic Table IV having a hydrocarbon group selected from an alkyl group, an aryl group, a π-enyl group and a π-cyclopentadienyl group as a ligand, and a trialkylaluminum. A method for polymerizing olefins, comprising using, as a catalyst, a reaction mixture obtained by reacting water with water.