JPH11100440A - Production of polyphenylene ether - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject ether industrially advantageously by performing an oxidative polymerization of a phenolic compound using a catalyst consisting of a specific amount of copper compound and a compound containing nitrogen and a solvent having a specific inductive capacity, by getting an excellent polymerization activity with is catalyst of low copper concentration. SOLUTION: This method for producing a polyphenylene ether is provided by performing an oxidative polymerization reaction at 0-80 deg.C using (A) 100 mole phenolic compound (especially 2,6-dimethylphenol), (B) a catalyst consisting of (i) 0. 00002-0.05 mole copper compound and (ii) one kind of compound containing nitrogen selected from aliphatic or aryl, primary, secondary or tertiary monoamine, diamine and triamine compounds and cyclic compounds containing nitrogen atom as a hetero atom, especially a compound of the formula (R1 to R4 are each an aliphatic hydrocarbon group, etc.), and (C) 90-100 wt.% solvent having 1.1-1.3 specific inductive capacity at 25 deg.C to obtain the objective ether.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an improved activity,
The present invention relates to a novel method for producing polyphenylene ether using a copper catalyst. More specifically, a catalyst comprising 0.00002 to 0.05 mol of a copper compound and a nitrogen-containing compound per 100 mol of a phenolic compound and a nonpolar solvent having a relative dielectric constant of 1.1 to 3.0 are used. The present invention relates to a method for producing polyphenylene ether, characterized by using a solvent system containing from 100 to 100% by weight.

[0002]

2. Description of the Related Art As a polymerization catalyst used for producing polyphenylene ether by oxidative polymerization of a phenolic compound, a catalyst comprising a combination of a copper compound and various amines has been proposed since Japanese Patent Publication No. 36-18892. Many have been proposed. For example, the type of copper compound and the proposal of a halide cooperating therewith, or the choice of primary amine, secondary amine or tertiary amine for amine,
Various proposals have been made such as monoamine, diamine or polyamine.

[0003] As a specific example, US Pat.
No. 875, No. 3344116 and No. 3432466, and the copper compounds and N, N, N ', N'
A method using a tetraalkyl-type diamine catalyst system such as tetramethyl-1,4-butanediamine; and copper compounds and tetraalkyl compounds disclosed in JP-B-52-17075 and JP-B-52-17076. Combination catalysts with diamines and iodine compounds of the type. However, none of them was sufficient in terms of catalytic activity.

Japanese Patent Publication No. 59-53012 states that a combination of a copper compound and a tertiary amine such as N, N'-di-tert-butylethylenediamine and N-methylpyrrolidine has relatively high activity. However, the polymer produced using this catalyst system has poor color, and the impact resistance of a composition with a styrene resin such as rubber-modified polystyrene is low,
It became clear that it was not practical because of poor heat resistance stability.

For this reason, in Japanese Patent Publication No. 59-23332, a practical catalyst was first obtained by combining the above-mentioned catalyst system with a secondary monoamine such as N-di-n-butylamine. Further, with respect to this catalyst system, a production method in which the amount of bromide ion is 1:35 or more in a molar ratio to the starting phenolic compound (JP-A-59-7).
No. 4124), a method comprising using a mixture of a copper (I) salt and a copper (II) salt as a copper compound (JP-A-5959 / 1984).
JP-A-131627) and a catalyst system using dimethylamine as a secondary monoamine (JP-B-60-54327) are also known.

It has been found that the copper component remaining in the catalyst has an adverse effect on the physical properties, hue, and thermal stability of polyphenylene ether and its composition, and a step of removing the catalyst residue is required. If the amount of the copper compound used as a catalyst in a highly active polymerization system can be reduced, the amount of the solvent used in the step of removing the residual catalyst can be reduced, and the cost of recovering the solvent can be reduced. There is an advantage that the equipment can be downsized, and the catalyst removal process is greatly simplified.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a method for producing polyphenylene ether having excellent polymerization activity in a low copper concentration region. It is.

[0008]

Means for Solving the Problems The present applicant has previously described Japanese Patent Application Laid-Open No. Hei.
No. 33131, a copper compound and a secondary aliphatic amine or a secondary aliphatic amine and an aniline having a special structure and N, N, N ', N'-tetramethyl-1,3-diamino (substituted or unsubstituted) And b) a method using a catalyst comprising propane and a bromine or chlorine compound. According to this method, the polymerization can be carried out with a lower copper content, and the quality of the obtained polyphenylene ether is such that the color tone and the strength of Izod impact when a rubber-reinforced polystyrene or the like is blended to form a composition. Significantly better.

[0009] As a result of further study on a more active polymerization system, surprisingly, the phenolic compound 100
When a copper compound and a nitrogen-containing compound are used as a catalyst in an amount of 0.00002 to 0.05 mol per mol, a nonpolar solvent having a relative dielectric constant of 1.1 to 3.0 is used as a solvent.
The present inventors have found that polymerization can be carried out with a very high activity when polymerization is carried out using a solvent system containing -100% by weight.

That is, the present invention relates to a method for producing polyphenylene ether by oxidatively polymerizing a phenolic compound using a catalyst comprising a copper compound and a nitrogen-containing compound.
002 to 0.05 moles of a copper compound (b) aliphatic or aromatic primary, secondary or tertiary monoamine, diamine, triamine compounds and cyclic compounds containing a nitrogen atom as a hetero atom And (c) a solvent system containing 90 to 100% by weight of the total amount of a solvent having a relative dielectric constant at 25 ° C. of 1.1 to 3.0. It is intended to provide a method for producing polyphenylene ether, characterized by the above.

Hereinafter, the present invention will be described in detail. In the present invention, as the copper compound, a cuprous salt, a cupric salt and a mixture thereof can be used. Although any compound of cuprous or cupric can be used, a soluble copper salt is preferred in terms of economy and availability of the compound. Further, compounds of usually insoluble salts (copper, cupric) can also be used.

As the cupric compound which can be used as the catalyst component of the present invention, for example, cupric chloride, cupric bromide, cupric sulfate, cupric nitrate, cupric acetate, cupric azide , Cupric toluate and the like, but are not limited to these examples. Examples of the cuprous compound that can be used include, for example, cuprous chloride, cuprous bromide, cuprous sulfate, cuprous nitrate, cuprous acetate, cuprous azide, cuprous toluate, and the like. It can be illustrated, but is not limited to these examples. Among these, preferred cuprous and cupric compounds are cuprous chloride, cupric chloride, cuprous bromide and cupric bromide. Further, these copper salts may be synthesized at the time of use from oxides, carbonates, hydroxides and the like and corresponding halogens or acids.

The amount of the copper compound to be used is 0.00002 mol to 0.05 mol, preferably 0.00002 mol to 0.1 mol, as copper per 100 mol of the phenolic compound.
It can be appropriately used in the range of 01 mol. This indicates that the amount of copper used can be used at an extremely low concentration with respect to the monomer. In other words, in the present invention, the activity per unit copper is extremely high.

The nitrogen-containing compound used in the present invention is selected from aliphatic or aromatic primary, secondary and tertiary monoamine, diamine and triamine compounds and cyclic compounds containing a nitrogen atom as a hetero atom. At least one compound is used. The aliphatic or aromatic primary, secondary, or tertiary amines have a structure in which an aliphatic hydrocarbon or an aromatic hydrocarbon is substituted as a nitrogen substituent of the corresponding compound, and secondary or tertiary amines are used. The substituent of the nitrogen of the secondary amine may be a substituent of only an aliphatic hydrocarbon,
It may be a substituent of only aromatic hydrocarbon. It may be a coexisting substituent of an aliphatic hydrocarbon and an aromatic hydrocarbon.

Diamines and triamines have two or more nitrogen atoms, and each nitrogen substituent may be a substituent of only an aliphatic hydrocarbon, or a substituent of only an aromatic hydrocarbon or an aliphatic hydrocarbon or an aromatic hydrocarbon. It may be a coexisting substituent of an aromatic hydrocarbon. Furthermore, each nitrogen is independently primary, secondary,
Grade, tertiary may be.

The cyclic compound containing a nitrogen atom as a hetero atom may have any structure as long as the compound has a nitrogen atom in its cyclic skeleton. The amount of such a nitrogen-containing compound is not particularly limited, but is preferably used in an amount of 0.05 to 10 mol based on 100 mol of the phenolic compound.

Specific examples thereof include monoalkylamines, dialkylamines, trialkylamines, alkanolamines, anilines, N-hydrocarbon-substituted anilines, diphenylamines, and cyclic amines as one nitrogen-containing compound. Preferred examples of the two nitrogen-containing compounds such as pyridine, pyridines and the like are ethylenediamine and their hydrocarbon (aromatic hydrocarbon) substituted products, propanediamine and their hydrocarbon (aromatic hydrocarbon) substituted products, imidazoles and the like. As Examples of the trinitrogen-containing compound include diethylenetriamine and substituted hydrocarbons (aromatic hydrocarbons) thereof, dipropanetriamine and substituted hydrocarbons (aromatic hydrocarbons) thereof, and the like.

It is preferable to use a combination of at least one secondary amine and a tertiary aliphatic propanediamine. Preferred second
In the lower aliphatic amine, the groups bonded to nitrogen each independently have 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms.
It is an amine that has individuality. In particular, a secondary fat which is an alkyl group or an aralkyl group having 1 to 8, preferably 2 to 6, more preferably 3 to 5 carbon atoms in that it is readily commercially available. The use of group amines is preferred.

The preparation of the catalyst is not particularly limited, and the catalyst can be used by dissolving it in a solvent mainly containing a reaction solvent to be used. It can be performed using a mixed solvent. For example, benzene, toluene,
Aromatic hydrocarbons such as xylene and ethylbenzene may coexist, and further, a phenolic compound monomer or the like may be mixed. Dissolving the copper compound;
Alternatively, if it is noted that at least a part of the copper compound is dissolved during the preparation, the object can be achieved by a method generally known to those skilled in the art. It may be prepared in the atmosphere, and the preparation temperature is not particularly limited.

The phenolic compound used in the present invention is

[0021]

Embedded image Wherein R ₄ represents an alkyl group, a substituted alkyl group, an aralkyl group, a substituted aralkyl group, an aryl group, a substituted aryl group, an alkoxy group, or a substituted alkoxy group, and R ₅ represents R ₄ R ₆ may be further halogen in addition to those defined for R ₅ , in addition to those defined.

Specific examples thereof include 2,6-dimethylphenol, 2,3,6-trimethylphenol,
2-methyl-6-ethylphenol, 2,6-diethylphenol, 2-ethyl-6-n-propylphenol, 2-methyl-6-chlorophenol, 2-methyl-
6-bromophenol, 2-methyl-6-isopropylphenol, 2-methyl-6-n-propylphenol, 2-ethyl-6-bromophenol, 2-methyl-
6-n-butylphenol, 2,6-di-n-propylphenol, 2-ethyl-6-chlorophenol, 2-
Methyl-6-phenylphenol, 2,6-diphenylphenol, 2,6-bis- (4-fluorophenyl)
Phenol, 2-methyl-6-tolylphenol, 2,
6-ditolylphenol and the like.

These phenolic compounds may be used alone or in combination of two or more. A small amount of phenol, o-cresol, m-cresol, p
-It may contain cresol, 2,4-dimethylphenol, 2-ethylphenol and the like substantially. Of these phenolic compounds, 2,6-dimethylphenol is particularly important.

When the phenolic compound is oxidatively polymerized in the present invention, the ratio of the phenolic compound to the solvent can be selected from a wide range, but the phenolic compound concentration in the mixture is usually 70% by weight or less, preferably 5% by weight or less.
-40% by weight, more preferably 8-35% by weight.

In the method of the present invention, the relative dielectric constant is 1.1 to 1.1.
Solvent with a value of 3.0 is 90-100 by weight percent
Use by weight%. Examples of such a solvent include, for example, aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene, and aliphatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, and cycloheptane alone or as a mixture. be able to. Further, a solvent having a relative dielectric constant of more than 3.0 can be mixed and used in the range of 0 to 10%.

Examples thereof include chloroform, methylene chloride, 1,2-dichloroethane, trichloroethane, chlorobenzene, dichlorobenzene, halogenated hydrocarbons such as trichlorobenzene, nitro compounds such as nitrobenzene, methanol, ethanol and propanol. Alcohols such as butanol, benzyl alcohol and cyclohexanol, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and ethyl formate, ethers such as tetrahydrofuran and diethyl ether, amides such as dimethylformamide and dimethyl sulfoxide. Examples of such sulfoxides and water.

In the present invention, the relative permittivity of the solvent is a value measured by the following method. Assuming that the electric capacity when the solvent sample is filled between the electrodes is C, and the electric capacity in a vacuum where there is no substance is C ′, the relative permittivity is C / C ′. In the experiment, the capacitance in air was used as C '. HEWLE
TT PACKARD LF impedance analyzer Model 4192A and liquid measurement electrode HP1645
The measurement was performed at 20 ° C. using 2A.

With respect to the solvent system used for the polymerization, the precipitation of polyphenylene ether with the progress of polymerization can be controlled by the ratio of a good solvent that easily dissolves polyphenylene ether to a poor solvent that hardly dissolves polyphenylene ether. Good solvents include aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, chloroform, methylene chloride,
Examples thereof include halogenated hydrocarbons such as 1,2-dichloroethane, trichloroethane, chlorobenzene, dichlorobenzene, and trichlorobenzene, and nitro compounds such as nitrobenzene.

Examples of the poor solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, cyclohexane and cycloheptane; alcohols such as methanol, ethanol, propanol, butanol, benzyl alcohol and cyclohexanol; ketones such as acetone and methyl ethyl ketone. And esters such as ethyl acetate and ethyl formate; ethers such as tetrahydrofuran and diethyl ether; amides such as dimethylformamide; sulfoxides such as dimethylsulfoxide; and water.

The present invention can be applied to polymerization methods such as a batch polymerization method, a continuous polymerization method, a solution polymerization method, and a precipitation polymerization method. In the polymerization, a catalyst, a phenolic compound, a solvent, and oxygen are introduced into a reactor, and the reaction proceeds by increasing the contact efficiency between oxygen and the solution by a method such as stirring.

Surfactants, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal alkoxides, neutral salts such as magnesium sulfate and calcium chloride, zeolites and the like may be added to the polymerization reaction system. it can.

If the polymerization reaction temperature is too low, the reaction hardly proceeds, and if it is too high, the catalyst may be deactivated. Therefore, the polymerization reaction temperature is preferably in the range of 0 to 80 ° C, preferably 10 to 70 ° C. preferable. As the oxygen in the oxidative polymerization of the present invention, in addition to pure oxygen, those mixed with an inert gas such as nitrogen at an arbitrary ratio, air, and the like can be used. The pressure in the system during the reaction is usually at normal pressure, but it can be used under reduced pressure or under increased pressure as needed.

In the present invention, if necessary, dibutylamine,
A monoamine such as N-ethylaniline can be added for the purpose of modifying the resin. The post-treatment method after the completion of the polymerization reaction is not particularly limited. Usually, an acid such as hydrochloric acid or acetic acid, or ethylenediaminetetraacetic acid (EDTA) and a salt thereof, nitrilopolyacetic acid and a salt thereof are added to the reaction solution to deactivate the catalyst. The polyphenylene ether can be recovered by a simple operation of washing with a solvent which does not dissolve the polymer and drying.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to examples, but the present invention should not be limited by these examples. Regarding the polymerization activity, a method of measuring the polymerization rate by knowing the derivative of the amount of oxygen absorbed with respect to the polymerization time using a gas burette was used. The polymerization rate was represented by the number of moles of oxygen absorbed per minute (mol oxygen / min) at the beginning of polymerization. As a result of measuring the relative dielectric constant of the solvent, at 25 ° C, toluene was 2.4, methanol was 32.6, and 1-butanol was 1
7.5.

[0035]

【Example】

Example 1 Using a 200 ml flask-type reactor, the catalytic activity was examined based on the polymerization rate and the reached viscosity after polymerization for a certain period of time. That is, 4.00 g (3,2-dimethylphenol) was placed in a 200 ml four-necked flask containing a magnetic stir bar.
2.7 mmol), and 25.50 g of toluene,
1.34 g of methanol was added and completely dissolved. In addition, cupric chloride dihydrate 0.00167 g was added to the equal-pressure dropping funnel.
(0.00982 mmol), and 0.447 g of methanol was further added and dissolved. A liquid composed of 0.2131 g (1.64 mmol) of N, N, N ', N'-tetramethyl-1,3-diaminopropane and 8.499 g of toluene prepared in another container was added thereto and mixed well.

The dropping funnel containing the prepared catalyst solution was attached to the four-necked flask, and the remaining opening was equipped with a cooling tube, a thermometer, and an oxygen introducing tube with a valve. The upper port of the cooling pipe was connected to a gas burette, a manometer, and a valved oxygen exhaust pipe for measuring oxygen absorption.
The system was replaced with oxygen while oxygen was introduced from the introduction pipe and air in the system was removed from the discharge pipe, and the system was immersed in a water bath capable of controlling the temperature. The valve of the oxygen inlet tube and the valve of the oxygen outlet tube were closed and the system was allowed to stabilize. The catalyst solution was added at once from the dropping funnel into the flask, and the polymerization was started with vigorous stirring.

The composition of the mixed solution immediately after mixing is as follows. That is, 2,6-dimethylphenol in the mixture was 10% by weight, and the solvent weight ratio was toluene: methanol = 9.
The ratio is 5: 5, and copper is 0.03 mol% with respect to the number of moles of 2,6-dimethylphenol;
N, N ', N'-tetramethyl-1,3-diaminopropane is 5.0 mol% based on the number of moles of 2,6-dimethylphenol. The polymerization solution temperature was controlled at 40 ° C. The amount of oxygen absorbed with respect to the polymerization time was determined using a gas burette, and the polymerization rate in a steady state was determined. The polymerization rate is 0.
It was 686 mmol oxygen / min.

Example 2 The procedure of Example 1 was repeated except that the copper compound was added in an amount of 0.01 mol% based on the number of moles of 2,6-dimethylphenol. That is, 2 with a magnetic stir bar
4.00 g (32.7 mmol) of 2,6-dimethylphenol was added to a 00 ml four-necked flask, and 25.50 g of toluene and 1.34 g of methanol were further added and completely dissolved. In addition, 0.000558 g (0.00327 mmol) of cupric chloride dihydrate was put into a constant-pressure dropping funnel, and 0.447 g of methanol was further added and dissolved.

The N, N, N ',
N'-tetramethyl-1,3-diaminopropane 0.2
131 g (1.64 mmol) and 8.499 g of toluene
Was added and mixed well, and then the solution was poured into the solution under constant pressure. Thereafter, the catalytic activity was examined at the polymerization rate by the same operation as in Example 1. The polymerization solution temperature was controlled at 40 ° C.
The polymerization rate was 0.087 mmol oxygen / min.

Comparative Example 1 Toluene: butanol: methanol = 6 as polymerization solvent
The procedure was performed in the same manner as in Example 1 except that a solvent having a weight ratio of 0:20:20 was used. That is, using a 200 ml flask-type reactor, the catalytic activity was examined based on the polymerization rate and the reached viscosity after the polymerization for a certain period of time. That is, 4.00 g (32.7 mmol) of 2,6-dimethylphenol was added to a 200-ml four-necked flask containing a magnetic stir bar, and 16.10 g of toluene, 5.37 g of n-butanol, and 5.37 g of methanol were further added. In addition, it was completely dissolved. In addition, cupric chloride dihydrate 0.00167 g was added to the equal-pressure dropping funnel.
(0.00982 mmol), and 1.789 g of methanol was further added and dissolved.

In addition, N, N, N ′,
N'-tetramethyl-1,3-diaminopropane 0.2
131 g (1.64 mmol) and 5.368 g of toluene
And 1.789 g of n-butanol were added and mixed well, and then the solution was added dropwise at an equal pressure. Thereafter, the catalytic activity was examined at the polymerization rate by the same operation as in Example 1. The polymerization solution temperature was controlled at 40 ° C. Polymerization speed is 0.355 m
mol oxygen / min. In this solvent system, Example 1 in which the toluene (relative dielectric constant: 2.4) composition is 90% or more.
The polymerization rate was lower than that.

Comparative Example 2 As a polymerization solvent, toluene: butanol: methanol = 6
The procedure was performed in the same manner as in Example 2 except that a solvent having a weight ratio of 0:20:20 was used. That is, using a 200 ml flask-type reactor, the catalytic activity was examined based on the polymerization rate and the reached viscosity after the polymerization for a certain period of time. That is, 4.00 g (32.7 mmol) of 2,6-dimethylphenol was added to a 200-ml four-necked flask containing a magnetic stir bar, and 16.10 g of toluene, 5.37 g of n-butanol, and 5.37 g of methanol were further added. In addition, it was completely dissolved. In addition, cupric chloride dihydrate (0.000558 g) was added to the equal-pressure dropping funnel.
(0.00327 mmol), and 1.789 g of methanol was further added and dissolved.

In addition, N, N, N ′,
N'-tetramethyl-1,3-diaminopropane 0.2
131 g (1.64 mmol) and 5.368 g of toluene
And 1.789 g of n-butanol were added and mixed well, and then the solution was added dropwise at an equal pressure. Thereafter, the catalytic activity was examined at the polymerization rate by the same operation as in Example 1. The polymerization solution temperature was controlled at 40 ° C. Polymerization speed is 0.041m
mol oxygen / min. In this solvent system, the polymerization rate was lower than in Example 2 in which the composition of toluene (dielectric constant: 2.4) was 90% or more.

Comparative Example 3 The procedure of Example 1 was repeated except that the copper compound was added in an amount of 0.2 mol% based on the number of moles of 2,6-dimethylphenol. That is, 20 with magnetic stir bar
4.00 g (32.7 mmol) of 2,6-dimethylphenol was added to a 0 ml four-necked flask, and 25.49 g of toluene and 1.34 g of methanol were further added to completely dissolve. In addition, 0.0112 g (0.0655 mmol) of cupric chloride dihydrate was put into the dropping funnel under constant pressure, and 0.447 g of methanol was further added and dissolved.

The N, N, N ',
N'-tetramethyl-1,3-diaminopropane 0.2
131 g (1.64 mmol) and toluene 8.497 g
Was added and mixed well, and then the solution was poured into the solution under constant pressure. Thereafter, the catalytic activity was examined at the polymerization rate by the same operation as in Example 1. The polymerization solution temperature was controlled at 40 ° C.
The polymerization rate was 2.831 mmol oxygen / min.

Comparative Example 4 Toluene: butanol: methanol = 6 as a polymerization solvent
The same operation as in Comparative Example 3 was performed except that a solvent having a weight ratio of 0:20:20 was used. That is, using a 200 ml flask-type reactor, the catalytic activity was examined based on the polymerization rate and the reached viscosity after the polymerization for a certain period of time. That is, 4.00 g (32.7 mmol) of 2,6-dimethylphenol was added to a 200-ml four-necked flask containing a magnetic stir bar, and 16.10 g of toluene, 5.37 g of n-butanol, and 5.37 g of methanol were further added. In addition, it was completely dissolved. In addition, 0.0112 g of cupric chloride dihydrate was added to the equal-pressure dropping funnel.
(0.0655 mmol), and methanol 1.
789 g was added and dissolved.

In addition, N, N, N ′,
N'-tetramethyl-1,3-diaminopropane 0.2
131 g (1.64 mmol) and 5.366 g of toluene
And 1.789 g of n-butanol were added and mixed well, and then the solution was added dropwise at an equal pressure. Thereafter, the catalytic activity was examined at the polymerization rate by the same operation as in Example 1. The polymerization solution temperature was controlled at 40 ° C. The polymerization speed is 3.417 m
mol oxygen / min. In this solvent system, the polymerization rate was higher than in Comparative Example 3 in which the toluene (relative dielectric constant: 2.4) composition was 90% or more. At a copper concentration of 0.2 mol%, unlike the tendency in Example 1 and Comparative Example 1 and in Example 2 and Comparative Example 2, the polymerization rate of a solvent system having a toluene composition of less than 90% was higher.

[0048]

In the process of the present invention, the use of an extremely high-activity catalyst system having improved activity requires a small amount of catalyst, and therefore, in the step of removing catalyst residue in the polymer, The amount of solvent used is small.
As a result, the cost of recovering the solvent is reduced, and the equipment for removing the catalyst can be reduced in size, thereby greatly simplifying the catalyst removal process. Furthermore, in the process according to the invention, the activity of the catalyst is very high, so that a highly efficient productivity can be realized.

Claims (4)

[Claims] 1. A method for producing a polyphenylene ether by oxidatively polymerizing a phenolic compound using a catalyst comprising a copper compound and a nitrogen-containing compound, wherein (a) 0.00002 to 0.1 mol per 100 mol of the phenolic compound.
At least one compound selected from the group consisting of 05 mol of a copper compound, (b) an aliphatic or aromatic primary, secondary or tertiary monoamine, diamine, triamine compound and a cyclic compound containing a nitrogen atom as a hetero atom. (C) a solvent having a relative dielectric constant of 1.1 to 3.0 at 25 ° C. in the range of 90 to 1
A method for producing polyphenylene ether, comprising using a solvent system containing 00% by weight. 2. The method for producing polyphenylene ether according to claim 1, wherein the amount of the copper compound (a) is 0.00002 to 0.01 mol per 100 mol of the phenolic compound. 3. The method of claim 2, wherein the nitrogen-containing compound (b) is (Wherein, R ₁ , R ₂ , R ₃ , and R ₄ are substituents of only aliphatic hydrocarbons, or substituents of only aromatic hydrocarbons, or coexistence type substitution of aliphatic hydrocarbons and aromatic hydrocarbons. The method for producing polyphenylene ether according to claim 1, wherein the compound is represented by the following formula: 4. The phenol compound to be oxidatively polymerized is 2,
The method for producing polyphenylene ether according to claim 1, which is 6-dimethylphenol.