JPH10237172A - Production of polyphenylene ether - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a polyphenylene ether highly efficiently by using an activity-improved catalyst using specified aminopropanes. SOLUTION: This polyphenylene ether is obtained by polymerizing a phenolic compound (preferably 2,6-dimethylphenol) by using a catalyst composed of (A) a copper compound, (B) a diaminopropane of the formula (R<1> -R<3> are each a substituent group except H), preferably N,N-dimethyl N'-methyl-1,3- diaminopropane, and (C) acids or bases, preferably halogen compounds and sulfonic acids (their salts), preferably in the condition that the oxidation- reduction potential of the complex of component B and copper is in the range of -50 to 250mV.

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 highly active copper catalyst. More specifically, a polyphenylene ether using a highly active catalyst comprising a copper compound, a diaminopropane having a structure represented by the following general formula (1), and an acid or a salt, having an improved activity for oxidative polymerization of a phenolic compound. And a method for producing the same.

[0002]

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[0003]

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. That is, various proposals have been made regarding the types of copper compounds and halides that cooperate therewith, the choice of amines as primary amines, secondary amines or tertiary amines, and monoamines, diamines or polyamines. Is being done.

For example, as old as US Pat. No. 3,306,875,
Nos. 3,344,116 and 3,432,466 disclose copper compounds and N, N, N ', N'-tetramethyl-1,4.
A method using a catalyst system of a tetraalkyl-type diamine such as butanediamine, and JP-B-52-1707.
No. 5 and JP-B-52-17076 disclose a combination of a copper compound with a tetraalkyl-type diamine and an iodine compound. However, none of these catalysts was sufficient in terms of catalytic activity.

Further, 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 is not practical because the color is poor and the impact resistance of the composition with a styrene resin such as rubber-modified polystyrene is low and the heat stability is poor. There was a point.

For this reason, Japanese Patent Publication No. 59-23332 succeeded in making a practical catalyst for the first time by combining a secondary monoamine such as N-di-n-butylamine with the above-mentioned catalyst system. Further, in this catalyst system, a production method wherein the amount of bromide ion is at least 1:35 in 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 (Japanese Patent Publication No. 60-54327) have also been proposed.

[0007]

However, these conventional catalysts are still insufficient in terms of polymerization activity, and further improvement has been desired.

[0008]

Means for solving the problem We have previously described Japanese Patent Application Laid-Open
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) ) The use of a catalyst consisting of propane and a bromine or chlorine compound has high polymerization activity and the quality of the obtained polyphenylene ether, especially the color tone and the Izod impact strength when a rubber-reinforced polystyrene or the like is blended to form a composition. It discloses that it is significantly better.

[0009] As a result of investigations to improve the catalyst and to provide a more active catalyst, surprisingly, N,
A very high catalyst using 1,3-diaminopropane having a substituent at a site represented by the following general formula (1) instead of N, N ', N'-tetramethyl-1,3-diaminopropane is extremely high. The present inventors have found that they have polymerization activity, and have reached the present invention.

[0010]

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That is, the present invention relates to the production of polyphenylene ether by oxidative polymerization of phenols,
A highly active catalyst comprising a copper compound, 1,3-diaminopropane having a substituent at a site represented by the following general formula (1), and an acid or a salt, having improved activity for oxidative polymerization of a phenolic compound: It is a method for producing polyphenylene ether, which is used.

[0012]

Embedded image (In the formula, R ₁ , R ₂ , and R ₃ represent a substituent of an organic compound or an inorganic compound, except for hydrogen.)

Hereinafter, the present invention will be described in detail. Copper compounds used in the present invention are cuprous salts, cupric salts and mixtures thereof. 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.

The cupric compound which can be used as the catalyst component of the present invention includes, 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 used is not particularly limited.
0.0 as copper per 100 moles of phenolic compound
It can be appropriately used in a range of from 02 mol to 0.5 mol, preferably from 0.005 mol to 0.1 mol. This indicates that the amount of copper used can be extremely low with respect to the monomer. In other words, in the present invention, the activity per unit copper is extremely high.

The diaminopropane used in the present invention is
At least one compound selected from 1,3-diaminopropane represented by the following general formula (1) having a structure in which one nitrogen of a diamine is a tertiary amine and the other nitrogen is a secondary amine is Used.

[0017]

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The nitrogen substituent of 1,3-diaminopropane may be a substituent of only an aliphatic hydrocarbon or a substituent of only an aromatic hydrocarbon, and may be a substituent of an aliphatic hydrocarbon or an aromatic hydrocarbon. It may be a substituent. Examples of diaminopropanes that can be used in the present invention include, but are not limited to:

N, N, N'-trimethyl-1,3-diaminopropane, N, N, N'-triethyl-1,3-diaminopropane, N, N-dimethyl-N'-ethyl-
1,3-diaminopropane, N, N-dimethyl-N'-
Propyl-1,3-diaminopropane, N, N-dimethyl-N′-butyl-1,3-diaminopropane, N, N
-Dimethyl-N'-phenyl-1,3-diaminopropane, N, N-diethyl-N'-methyl-1,3-diaminopropane, N, N-diethyl-N'-ethyl-1,3
-Diaminopropane, N, N-diethyl-N'-propyl-1,3-diaminopropane, N, N-diethyl-
N, N, such as N'-butyl-1,3-diaminopropane,
And N'-trialkyldiaminopropanes.

Among these diamines, those having a redox potential of the copper complex of -50 mV or more are preferable, and -50 mV is more preferable.
Those having a range of mV to 250 mV are more preferable.
Although the amount of 1,3-diamine is not particularly limited, it is used in an amount of 0.1 to 10 mol, preferably 1 to 6 mol, per 100 mol of the phenolic compound.

The acid or salts which can be used in the present invention are not particularly limited, but include hydrogen halides such as hydrogen chloride and hydrogen bromide, nitric acid, sulfuric acid, perchloric acid, tetrafluorophosphoric acid, sulfonic acids and salts thereof. And the use of solutions such as aqueous solutions thereof. Among these acids, preferred are hydrogen halides or sulfonic acids or their aqueous solutions. The amount of these acids is preferably 0.5 to 20 mol, more preferably 1 to 1 mol per mol of copper.
0 is used.

The method for preparing the catalyst is not particularly limited, and the catalyst can be dissolved in a reaction solvent mainly used. That is, for example, the reaction can be performed using an alcohol such as water, methanol, ethanol, and butanol, a mixed solvent of alcohols, and a mixed solvent with others. In the mixed solvent, for example, aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene may coexist, and additionally, a phenolic compound monomer and the like may be mixed. If it is noted that the copper compound is dissolved or that the copper compound is partially dissolved during the preparation, it can be prepared by a method commonly known to those skilled in the art. It may be prepared in the atmosphere, and the preparation temperature is not particularly limited.

The phenolic compounds used in the present invention is a compound having a structure represented by the following general formula (2), 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 may be a halogen in addition to those defined for R ₄ , R ₆ may be hydrogen in addition to those defined for R ₅ .

[0024]

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Examples of such a material are, for example, 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-propyl Phenol, 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 in a wide range, but the phenolic compound concentration in the mixture is usually 70% by weight or less,
Preferably it is in the range of 5 to 40% by weight, more preferably 8 to 35% by weight.

The reaction solvent used in the method of the present invention is less oxidizable than the phenolic compound to be oxidized, and has little reactivity to various radicals which are considered to be formed in the course of the reaction. There is no particular limitation as long as it is possible, but one that dissolves a low molecular weight phenolic compound and dissolves part or all of the catalyst mixture is preferable.

Examples of such solvents include, for example, aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, chloroform, methylene chloride, 1,2-dichloroethane, trichloroethane, chlorobenzene, dichlorobenzene and trichlorobenzene. And nitro compounds such as nitrobenzene, which can be used as a good solvent for the polymer.

Examples of the poor solvent for the polymer include alcohols such as methanol, ethanol, propanol, butanol, benzyl alcohol and cyclohexanol, aliphatic hydrocarbons such as pentane, hexane, heptane, cyclohexane and cycloheptane, and acetone. And ketones such as methyl ethyl ketone, 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.

One or more of these good solvents and, if necessary, one or more of poor solvents can be mixed and used.
It is preferable to include alcohols such as methanol and ethanol in the reaction solvent from the viewpoint of activity.

A solution polymerization method can be obtained by selecting a ratio of a good solvent and a poor solvent to polyphenylene ether, which is a polymer obtained by oxidative polymerization of a phenolic compound, and the reaction can be performed by increasing a ratio of a poor solvent. As the process proceeds, a precipitation polymerization method in which the polymer is precipitated as particles in the reaction solvent is also provided.

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. Surfactants, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal alkoxides,
Neutral salts such as magnesium sulfate and calcium chloride, zeolites and the like can also be added.

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.

Regarding the post-treatment method after the completion of the polymerization reaction,
There is no particular limitation. 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.

[0035]

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. For the polymerization activity, a method of measuring the polymerization rate by knowing the derivative of the amount of oxygen absorbed with respect to the time of polymerization using a gas burette,
There are two methods for measuring the viscosity of the polymer. The polymerization rate is represented by the number of moles of oxygen absorbed per minute (mol oxygen / min) in the initial stage of polymerization, and the viscosity (ηsp / c) of polyphenylene ether is 0.5 g of the polymer.
/ 100 ml chloroform solution at 30 ° C. using a Ubbelohde viscometer.

The oxidation-reduction potential was measured by the following method. 0.102 mmol cupric chloride dihydrate, HCl
A methanol solution containing 0.734 mmol and 10.2 mmol of amine was prepared by adding methanol to make the total amount 10 g. To this was added 0.1 M tetrabutylammonium perchlorate to dissolve. Cyclic voltammetry of this solution was measured, and the midpoint between the potential of the oxidation wave and the potential of the reduction wave was taken as the oxidation-reduction potential. Measuring equipment is BAS
The potential was changed at a rate of 100 mV / sec using BAS100B / W, glassy carbon as the working electrode, platinum wire as the counter electrode, and silver / silver chloride electrode as the reference electrode. The measurement was performed at 25 ° C. in a nitrogen atmosphere.

[0037]

【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 16.10 g of toluene,
5.37 g of n-butanol and 5.37 g of methanol were added and completely dissolved. In addition, 0.00279 g (0.0164 mmol) of cupric chloride dihydrate was added to the equal-pressure dropping funnel.
And 0.01229 g of 35% concentrated hydrochloric acid (0.1% as HCl)
18 mmol), and 1.790 g of methanol was further added and dissolved. The N, N-dimethyl-N'-ethyl-1,3-diaminopropane prepared in a separate container was added to 0.1.
2131 g (1.64 mmol) and 5.366 of toluene
g and 1.790 g of n-butanol were added and mixed well.

The dropping funnel containing the prepared catalyst solution was attached to the above-mentioned four-necked flask, and a cooling pipe, a thermometer, and an oxygen introducing pipe with a valve were attached to the remaining ports. 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: n-butanol:
Methanol = 60: 20: 20 ratio, and copper is 0.05 to the number of moles of 2,6-dimethylphenol.
mol%, N, N-dimethyl-N′-ethyl-
1,3-Diaminopropane is 5.0 mol% based on the number of moles of 2,6-dimethylphenol, and HCl is 7.2 equivalents based on the number of moles of copper. 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 was 0.697 mmol oxygen / min. The reaction liquid became a slurry during the polymerization. Three hours after the start of the polymerization, 5 times the volume of the methanol was added to the mixture, and the mixture was filtered and washed three times with methanol. This was vacuum-dried at 140 ° C. for 1 hour to obtain a polyphenylene ether powder. Ηsp / c of this polyphenylene ether was 0.58. The redox potential of the copper complex of N, N-dimethyl-N′-ethyl-1,3-diaminopropane was 95 mV.

Example 2 The procedure of Example 1 was repeated, except that hexane was used instead of methanol, which was used as a part of the polymerization solvent, and 1 g of anhydrous magnesium sulfate was added. The reaction liquid became a slurry during the polymerization. The polymerization rate is 0.75
It was 3 mmol oxygen / min. Further, ηsp / c of the obtained polyphenylene ether was 0.60.

Example 3 The procedure of Example 1 was repeated, except that only toluene was used as the polymerization solvent and anhydrous magnesium sulfate was added. That is, 4.00 g (32.7 mmol) of 2,6-dimethylphenol was added to a four-necked flask, and 26.83 g of toluene was further added to completely dissolve it. In addition, cupric chloride dihydrate 0.00279 g (0.0164 mmol
l) and 0.01229 g of 35% concentrated hydrochloric acid (0.118 mmol as HCl) and 0.2131 g of N, N-dimethyl-N'-ethyl-1,3-diaminopropane (1.
64 mmol) and dissolved. To this, 8.943 g of toluene was further added and mixed well, and then the solution was poured into an equal pressure dropping funnel. Thereafter, the same procedure as in Example 1 was carried out to examine the catalytic activity based on the polymerization rate and the viscosity reached after the polymerization for a certain time. The polymerization solution temperature was controlled at 40 ° C. The polymerization rate was 1.276 mmol oxygen / min. Ηsp / c of this polyphenylene ether was 0.65.

Example 4 In place of 35% concentrated hydrochloric acid used in Example 1, 0.0224 g (0.118 mmol) of p-toluenesulfonic acid monohydrate was used.
The procedure was performed in the same manner as in Example 1 except that l) was used. The polymerization rate was 0.836 mmol oxygen / min. Ηsp / c of this polyphenylene ether was 0.69.

Comparative Example 1 N, N-dimethyl-N'-ethyl- used in Example 1
N, N, N ', instead of 1,3-diaminopropane
N′-tetramethyl-1,3-diaminopropane was added to 0.
The same operation as in Example 1 was performed except that 2131 g (1.64 mmol) was used. The polymerization rate was 0.296 (0.28
8, 0.559) mmol oxygen / min. Further, ηsp / c of the obtained polyphenylene ether = 0.5
It was one. N, N, N ', N'-tetramethyl-1,
The redox potential of the copper complex of 3-diaminopropane is 20
It was 0 mV.

Comparative Example 2 N, N-dimethyl-N'-ethyl- used in Example 1
Instead of 1,3-diaminopropane, 0.2131 g of N, N-diethyl-1,3-diaminopropane (1.6 g) was used.
The procedure was the same as in Example 1 except that 4 mmol) was used.
The polymerization rate was 0.177 mmol oxygen / min.
Further, ηsp / c of the obtained polyphenylene ether =
(0.51). The redox potential of the copper complex of N, N-diethyl-1,3-diaminopropane is -152 m
V.

[0046]

In the method according to the present invention, an extremely high activity catalyst having an improved activity is used, so that the amount of the catalyst used can be reduced. The amount of solvent to be 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. In addition, the process according to the invention has a very high activity and can achieve a highly efficient productivity.

Claims (8)

[Claims] 1. A method for producing a polyphenylene ether in which a phenolic compound is oxidatively polymerized using a catalyst, comprising: (a) a copper compound, (b) a diaminopropane represented by the following general formula (1), and (In the formula, R ₁ , R ₂ , and R ₃ represent substituents of an organic compound or an inorganic compound, except for hydrogen.) (C) A polyphenylene ether characterized by using a catalyst comprising an acid or a salt. Production method. 2. The amine represented by the general formula (1) of (b), wherein R ₁ , R ₂ , and R ₃ are a substituent of only an aliphatic hydrocarbon, a substituent of only an aromatic hydrocarbon, or an aliphatic. The method for producing a polyphenylene ether according to claim 1, wherein the substituent is a coexisting type of a hydrocarbon and an aromatic hydrocarbon. 3. The amine-copper complex represented by (b) represented by the general formula (1) has a redox potential of -50 mV to 250 mV.
The method for producing a polyphenylene ether according to claim 1 or 2, wherein the method is in the range of mV. 4. The method according to claim 1, wherein the amine represented by the general formula (1) in (b) is N, N-dimethyl N′-methyl 1,3-diaminopropane. The method for producing the polyphenylene ether according to the above. 5. The method according to claim 1, wherein the amine represented by the general formula (1) in (b) is N, N-dimethyl N′-ethyl 1,3-diaminopropane. The method for producing the polyphenylene ether according to the above. 6. The method for producing polyphenylene ether according to claim 1, wherein the acid or salt of (c) is a halogen compound. 7. The method according to claim 1, wherein the acid or salt of (c) is a sulfonic acid or a sulfonic acid salt.
5. The method for producing a polyphenylene ether according to any one of 5. 8. The phenolic compound to be polymerized is 2,6.
-Dimethylphenol.
8. The method for producing a polyphenylene ether according to any one of items 1 to 7.