JPH08268927A - Purification of cyclic olefin and polymerization - Google Patents

Abstract

PURPOSE: To purify a cyclic olefin containing impurities into a purified product having industrially sufficient polymerization activity by bringing a cyclic olefin containing impurities into contact with a basic aqueous solution and to successively polymerize the purified product in high yield by using a specific catalyst. CONSTITUTION: (A) A cyclic olefin containing impurities is brought into contact with (B) a basic aqueous solution such as an aqueous solution of an alkaline (earth) metal hydroxide or (hydrogen)carbonate to purify the component A and optionally successively, the cyclic olefin phase obtained by the purification is polymerized in the presence of (C) a metallocene compound of the formula (M is Ti, Zr or Hf; A is a mononuclear or polynuclear hydrocarbon group; R<1> is a disubstituted silylene by a 1-4C alkylene, a 1-6C alkyl or a 6-13C aryl; R<2> and R<3> are each a halogen, a 1-6C alkyl or a 6-13C aryl).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a purification method for removing impurities contained in a cyclic olefin and a polymerization method for the cyclic olefin.

[0002]

2. Description of the Related Art As a method for polymerizing a cyclic olefin, a method using a metallocene catalyst is disclosed (Japanese Patent Laid-Open No. 64-66216).
Japanese Patent Laid-Open No. 2-180910) and the like have been proposed. However, the polymerization activity of the catalyst is considerably low because the cyclic olefin monomer, which is a raw material in these cyclic olefin polymerization methods, is unpurified or insufficiently purified.

Cyclic olefins that are commercially available or obtained as industrial raw materials contain polymerization inhibitors and impurities such as ketones and epoxy compounds. Further, these impurities must be removed when the cyclic olefin is polymerized, because they hinder the polymerization.

Therefore, as a method for purifying cyclic olefins for removing such impurities, a method of contact treatment with an inorganic substance such as silica gel or alumina has been proposed (East German Patent No. 213667, JP-A-5-1325).
No. 23). However, the cyclic olefins purified by these methods still contain a small amount of impurities,
When polymerization was carried out using the obtained cyclic olefin, the polymerization activity was insufficient.

As a method for purifying other cyclic olefins, a method by distillation is generally used. However, when the polymerization is carried out using the cyclic olefin purified by this method, its polymerization activity is increased, but when it is industrially carried out, a large amount of equipment cost and fixed cost are required.
There is a demand for a more convenient method and a method capable of obtaining good polymerization activity.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a method for purifying a cyclic olefin and a method for polymerizing the cyclic olefin, which can easily remove the cyclic olefin containing impurities when the polymerization of the cyclic olefin is carried out to obtain industrially sufficient polymerization activity. The purpose is to provide.

[0007]

Means for Solving the Problems The present inventors have found that when a cyclic olefin containing impurities is brought into contact with a basic aqueous solution, the polymerization activity is increased when the cyclic olefin is continuously polymerized, The present invention has been completed.

That is, the present invention is a method for purifying a cyclic olefin, which comprises contacting the cyclic olefin containing impurities with a basic aqueous solution.

Examples of the cyclic olefin used in the present invention include cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, 3-methylcyclopentene, 3-methylcyclohexene, 1,4-dimethylcyclohexene, 1,3-cyclohexadiene,
Examples thereof include 1,4-cyclohexadiene, 1,3-cycloheptadiene, norbornene, 1,3,5-cycloheptatriene, 1,5-cyclooctadiene and cyclododecene. Further, the ring of these cyclic olefins may be further substituted with a linear or branched alkyl group.

These cyclic olefins which are commercially available or obtained as industrial raw materials contain polymerization inhibitors and impurities such as aldehydes, alcohols, ketones and epoxy compounds. For example, commercially available cyclopentene has a polymerization inhibitor such as hydroquinone and n- as an impurity.
Valeric aldehyde, 4-penten-1-ol, cyclopentene oxide, cyclopentanone, cyclopentanol, 2-cyclopenten-1-one and the like are included. These impurities, when polymerizing the cyclic olefin,
The polymerization activity of the catalyst is hindered, and among them, aldehydes and alcohols particularly hinder the polymerization. Commercial cyclic olefins,
In particular, cyclopentene contains a total of about 8000 to 10000 mol ppm of aldehydes and alcohols.

The basic aqueous solution used in the present invention includes hydroxides of alkali metals or alkaline earth metals,
An aqueous solution of an alkali metal or alkaline earth metal carbonate, or an alkali metal or alkaline earth metal hydrogen carbonate is used. Specific examples include potassium hydroxide, sodium hydroxide, lithium hydroxide, barium hydroxide, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate and the like. Among these, potassium hydroxide aqueous solution and sodium hydroxide aqueous solution are particularly preferable in terms of industrial availability and cost.

These aqueous solutions may be used alone or 2
You may mix and use 1 or more types. The concentration of the aqueous solution is not particularly limited, but a 1% to 50% aqueous solution is preferably used.

In the present invention, the contact condition between the cyclic olefin containing impurities and the basic aqueous solution is not particularly limited, and any condition can be adopted. Contact temperature is generally 0
It is preferably -100 ° C, more preferably 10-50 ° C.
It is preferred that The contact time is preferably 10 minutes to 24 hours, more preferably 30 minutes to 10 hours. The pressure at the time of contact is atmospheric pressure to 50a.
tm is preferable, and atmospheric pressure is 10 atm.
It is preferably in the range of. The amount of the basic aqueous solution used for this contact varies depending on the concentration of the aqueous solution and the amount of impurities in the cyclic olefin, but is preferably 10 to 1000% by volume with respect to the cyclic olefin containing impurities, Further, it is preferably 50 to 300%. Furthermore, the cyclic olefin containing impurities at the time of this contact may be dissolved in a solvent that does not react with the basic aqueous solution and treated. Examples of such a solvent include inert aliphatic or aromatic hydrocarbons, and specific examples thereof include pentane, hexane, heptane, octane, cyclopentane, cyclohexane, benzene, toluene and xylene.

The method of contacting the cyclic olefin containing impurities of the present invention with the basic aqueous solution is, for example, when the cyclic olefin is a liquid, it is basic in a container made of stainless steel or lined with glass, fluororesin or the like. Examples include a method of stirring an aqueous solution and a cyclic olefin and stirring, and when the cyclic olefin is a gas, a method of bubbling a gaseous cyclic olefin into a basic aqueous solution or a basic aqueous solution after being liquefied by pressurization. And the like.

In the present invention, the cyclic olefin after contacting with the basic aqueous solution has a total content of aldehydes and alcohols of not more than 3000 mol ppm, and can be used for polymerization only by separating the basic aqueous solution. it can.

Next, the above-purified cyclic olefin is subjected to polymerization. The polymerization catalyst has the following formula

[0017]

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(Here, M is Ti, Zr or Hf, A is a mononuclear or polynuclear hydrocarbon group having a cycloalkadienyl skeleton, and R ¹ is an alkylene group having 1 to 4 carbon atoms, or a carbon atom. A silylene group in which two hydrogen atoms are substituted with an alkyl group having 1 to 6 and / or an aryl group having 6 to 13 carbon atoms, and R ² and R ³ are the same or different, a halogen atom, and a carbon number 1 A metallocene compound represented by an alkyl group having 6 to 6 or an aryl group having 6 to 13 carbon atoms is used.

Specific examples of A include methylcyclopentadienyl group, dimethylcyclopentadienyl group, trimethylcyclopentadienyl group, tetramethylcyclopentadienyl group, ethylcyclopentadienyl group and i-propyl. Cyclopentadienyl group, t-butylcyclopentadienyl group, indenyl group, methylindenyl group, dimethylindenyl group, i-propylindenyl group, t-
Examples thereof include a butylindenyl group and a fluorenyl group.

Specific examples of R ¹ include methylene group, ethylene group, propylene group, butylene group, dimethylsilylene group, diethylsilylene group, diphenylsilylene group, phenylmethylsilylene group and the like.

The halogen atom for R ² and R ³ is chlorine,
Examples of the alkyl group include bromine and iodine, and examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an n group.
-Butyl group, i-butyl group, t-butyl group and the like, and the aryl group includes phenyl group, toluyl group and the like.

Specific examples of the metallocene compound that can be preferably used in the present invention include dimethylmethylenebis (indenyl) zirconium dichloride, dimethylsilylenebis (indenyl) zirconium dichloride,
Examples thereof include ethylene bis (indenyl) zirconium dichloride, dimethylsilylene bis (2-methylindenyl) zirconium dichloride, and dimethylsilylene bis (methylcyclopentadienyl) zirconium dichloride.

In the polymerization of the present invention, an aluminum compound is generally used in combination with the above metallocene compound. The aluminum compound may be used alone or 2
You may mix and use 1 or more types of aluminum compounds. As the aluminum compound, an organic aluminum oxy compound, an alkylaluminum, or an alkylaluminum halide can be preferably used. These compounds will be described below.

Organoaluminum oxy compound

[0025]

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Or the following general formula

[0027]

[Chemical 4]

A known organoaluminumoxy compound represented by the formula (wherein R ⁴ represents an alkyl group having 1 to 6 carbon atoms and n represents an integer of 2 to 40) is used. Particularly preferably, an organoaluminumoxy compound in which R ⁴ is a methyl group, that is, polymethylaluminoxane can be used.

Alkyl Aluminum Specific examples of the alkyl aluminum used in the present invention include trialkyl aluminum such as trimethyl aluminum, triethyl aluminum and tributyl aluminum. Particularly preferably, trimethylaluminum can be used.

Alkyl Aluminum Halide Specific examples of the alkyl aluminum halide used in the present invention include ethyl aluminum dichloride,
Examples thereof include ethyl aluminum sesquichloride, diethyl aluminum chloride, dimethyl aluminum fluoride, butyl aluminum sesquichloride. Particularly preferably, dimethyl aluminum fluoride can be used.

The amount of the aluminum compound used is preferably 10 to 10,000 times, and particularly preferably 100 times, the molar ratio of the aluminum atom to the metal atom of the metallocene compound.
~ 1000 times. When two or more kinds of aluminum compounds are used, it is preferable that the total sum of aluminum atoms is included in the above range.

The polymerization method is not particularly limited, but
Examples thereof include gas phase polymerization, solution polymerization, bulk polymerization and the like. Further, either continuous polymerization or discontinuous polymerization may be used. The polymerization temperature is in the range of 0 to 200 ° C, preferably 20 to 100 ° C. The polymerization time can be appropriately determined, but is usually 10
The range is from minutes to 48 hours.

[0033]

EFFECTS OF THE INVENTION According to the present invention, a cyclic olefin can be purified very easily by bringing the cyclic olefin containing impurities into contact with a basic aqueous solution, and by carrying out polymerization using the purified cyclic olefin. Polymerization activity is significantly improved.

[0034]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 (Purification of cyclic olefin) In a 100 ml glass container, 20 ml of 10% aqueous potassium hydroxide solution and 20 ml of commercially available cyclopentene (total content of aldehydes and alcohols: 8630 mol ppm) were placed under a nitrogen atmosphere. , 25 ℃
The mixture was stirred for 1 hour. Then, the cyclopentene phase was separated from the aqueous phase and used as it was in the polymerization step.

(Polymerization of cyclic olefin) In a 100 ml flask, 25 ml of toluene at 30 ° C. in a nitrogen atmosphere and polymethylaluminoxane in terms of aluminum atoms of 7.
5 mmol and ethylene bis (indenyl) zirconium dichloride 0.025 mmol were added and stirred for 10 minutes. Then, 10 m of cyclopentene purified above
1 was added and polymerization was carried out at 30 ° C. for 20 hours. After that,
Add the reaction solution to 300 ml of methanol and add 15m.
l 12N hydrochloric acid was added, and the mixture was stirred at 25 ° C for 30 minutes. Next, the solid component obtained here was filtered, and the solid component was treated again with 300 ml of methanol and 15 ml of concentrated hydrochloric acid in the same manner. Further, this slurry was filtered, and the obtained solid component was washed with 200 ml of methanol. The solid component thus obtained was dried in a vacuum dryer heated to 70 ° C. for 12 hours.
By drying for an hour, 5.8 g of polycyclopentene was obtained. The results are shown in Table 1.

Examples 2 to 4 The contact treatment time between cyclopentene and an aqueous solution of potassium hydroxide was 30 minutes (Example 2), 5 hours (Example 3) and 1
Example 1 was repeated except that the time was set to 0 hour (Example 4). The results are shown in Table 1.

Example 5 15% aqueous sodium hydroxide solution 10 as a basic aqueous solution
Cyclopentene was purified and polymerized in the same manner as in Example 1 except that ml was used. The results are shown in Table 1.

Example 6 Instead of the commercially available cyclopentene in Example 1, commercially available cycloheptene (total content of aldehydes and alcohols was 9120 mol ppm) was used, and the polymerization temperature was 20.
Cycloheptene was purified and polymerized in the same manner as in Example 1 except that the temperature was changed to ° C. The results are shown in Table 1.

Examples 7 to 11 The same operations as in Example 1 were carried out except for the type and amount of cyclic olefin shown in Table 1, the type and concentration of basic aqueous solution shown in Table 1, the amount and the treatment time. . The results are shown in Table 1.

[0041]

[Table 1]

Comparative Example 1 Commercially available cyclopentene was polymerized in the same manner as in Example 1 without purification treatment with a basic aqueous solution.
Table 2 shows the results.

Comparative Example 2 20 m of commercially available cyclopentene was placed in a 100 ml glass container.
1 and 2 g of activated alumina were added and stirred for 5 hours, and then the same procedure as in Example 1 was carried out except that cyclopentene from which the activated alumina had been removed by filtration was used for polymerization without contact treatment with a basic aqueous solution. It was Table 2 shows the results.

Comparative Examples 3 to 8 Instead of the activated alumina of Comparative Example 2, calcium sulfate (Comparative Example 3), calcium oxide (Comparative Example 4), calcium chloride (Comparative Example 5), barium oxide (Comparative Example 6), and molecular weight. Comparative Example 2 was repeated except that Sieves (Comparative Example 7) and silica gel (Comparative Example 8) were used.
Table 2 shows the results.

Comparative Example 9 20 ml of commercially available cycloheptene was added to a 100 ml flask.
After adding 2 g of activated alumina and stirring for 1 hour, cycloheptene from which activated alumina had been removed by filtration was used, and cycloheptene was polymerized in the same manner as in Example 6 without contact treatment with a basic aqueous solution. Table 2 shows the results.

[0046]

[Table 2]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C07C 13/42 C07C 13/42 C08F 4/642 MFG C08F 4/642 MFG 32/04 MNV 32/04 MNV

Claims (2)

[Claims] 1. A method for purifying a cyclic olefin, which comprises contacting a cyclic olefin containing impurities with a basic aqueous solution. 2. A cyclic olefin containing impurities is contacted with a basic aqueous solution, and then the cyclic olefin is represented by the following general formula: (Here, M is Ti, Zr, or Hf, A is a mononuclear or polynuclear hydrocarbon group having a cycloalkazinier skeleton, R ¹ is an alkylene group having 1 to 4 carbon atoms, and 1 to 4 carbon atoms. 6 alkyl group and / or 6 to 13 carbon atoms
Is a silylene group in which two hydrogen atoms have been substituted with, and R ² and R ³ are the same or different, a halogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 13 carbon atoms. is there. ) Polymerizing in the presence of a metallocene compound represented by the formula (4).