JPH11286542A - Improved production of polyphenylene ether - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrially advantageous improved method for producing a polyphenylene ether by which the polymerization activities are improved by carrying out an oxidation polymerization of a specific dimethylphenol in the presence of a catalyst and oxygen in a solvent. SOLUTION: (A) 2,6-Dimethylphenol containing (i) <0.30 wt.% other alkyl phenols is subjected to an oxidation polymerization in the presence of (B) a catalyst and (C) oxygen in (D) a solvent to provide the objective polyphenylene ether in the method for producing the polyphenylene ether. Orthocresol, orthoethylphenol, metacresol, paracresol, 2,4,6-trimethylphenol or the like is cited as the component (i). The component B preferably contains (ii) a copper compound (e.g. cupric chloride) and (iii) an amine compound of the formula [R1 to R4 are each H or a 1-6C alkyl, with the proviso that the whole thereof is not simultaneously H; R5 is a (methyl-branched) 2-5C alkylene], (e.g. N,N,N',N '-tetramethyl-1,3-diaminopropane).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for producing an improved polyphenylene ether having a high polymerization activity.

[0002]

2. Description of the Related Art As a polymerization catalyst used for producing polyphenylene ether by oxidative polymerization of a phenolic compound, 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, the type of copper compound and the proposal of a halide cooperating therewith, and the
Various proposals have been made such as selection between a tertiary amine, secondary amine and tertiary amine, and monoamine, diamine or polyamine.

[0003] For example, as old as US Pat.
Nos. 3,344,116 and 3,432,466 disclose a copper compound and N, N, N ', N'-tetramethyl-
A method using a catalyst system of a tetraalkyl-type diamine such as 1,4-butanediamine, and Japanese Patent Publication No. 52-1707
No. 5, JP-B-52-17076 also proposes a combination of a copper compound with a tetraalkyl-type diamine and an iodine compound. In addition, Japanese Patent Publication No. 59-53
No. 012 and JP-B-59-23332 disclose a combination of a copper compound with a tertiary amine such as N, N'-di-tert-butylethylenediamine and N-methylpyrrolidine, or a combination of the tertiary amine with di-n-butylamine. And the like comprising a combination with a secondary monoamine. JP-A-64-33131 discloses 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-. A highly active process with improved water resistance by using diamino (substituted or unsubstituted) propane and bromine or chlorine compounds is disclosed.

In these methods, by-products in 2,6-dimethylphenol as a raw material have been used without particular attention.

[0005]

SUMMARY OF THE INVENTION
There was a problem that the polymerization activity was not sufficient depending on the production method of 6-dimethylphenol. An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a method for producing an industrially useful polyphenylene ether having improved polymerization activity.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, surprisingly, the by-product produced when 2,6-dimethylphenol is produced. Found that they significantly inhibited the polymerization activity, leading to the present invention. That is, the present invention provides a process for producing polyphenylene ether by oxidative polymerization of 2,6-dimethylphenol in a solvent using a catalyst and oxygen,
Good polymerization activity can be obtained by reducing the content of other alkylphenols contained in 2,6-dimethylphenol to less than 0.30% by weight.

Hereinafter, the present invention will be described in detail. The polymerization catalyst used in the present invention is not particularly limited, but preferred catalysts are as follows. (A) a copper compound and (b) the following formula (1)

[0008]

Embedded image

A catalyst comprising a diamine compound having the structure of Examples of the copper compound of the catalyst component (a) described here are listed. Suitable copper compounds include cuprous compounds,
Cupric compounds or mixtures thereof can be used. Examples of the cupric compound include cupric chloride, cupric bromide, cupric sulfate, cupric nitrate and the like. Further, as the cuprous compound, for example, cuprous chloride,
Examples include cuprous bromide, cuprous sulfate, cuprous nitrate and the like. Of these, particularly preferred metal compounds are cuprous, and cupric chloride, cupric 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 not particularly limited, but when combined with a diamine compound described below, the amount of copper is generally 0.00001 to 0.5 mol or less, preferably 0.0001 to 0.5 mol as copper per 100 mol of the phenolic compound. It is used in a range of 3 mol, more preferably in a range of 0.0001 to 0.150 mol. This indicates that the copper compound can be used at a very low concentration, and the present invention can be effectively used when such a highly active catalyst is used.

Next, examples of the diamine compound as the catalyst component (b) will be listed. For example, N, N, N ', N'-tetramethylethylenediamine, N, N, N'-trimethylethylenediamine, N, N'-dimethylethylenediamine,
N-dimethylethylenediamine, N-methylethylenediamine, N, N, N ′, N′-tetraethylethylenediamine, N, N, N′-triethylethylenediamine,
N, N′-diethylethylenediamine, N, N-diethylethylenediamine, N-ethylethylenediamine,
N, N-dimethyl-N′-ethylethylenediamine,
N, N'-dimethyl-N-ethylethylenediamine, N
-N-propylethylenediamine, N, N'-n-propylethylenediamine, Ni-propylethylenediamine, N, N'-i-propylethylenediamine, N-
n-butylethylenediamine, N, N′-n-butylethylenediamine, Ni-butylethylenediamine,
N, N'-i-butylethylenediamine, Nt-butylethylenediamine, N, N'-t-butylethylenediamine, N, N, N ', N'-tetramethyl-1,3-
Diaminopropane, N, N, N'-trimethyl-1,3
-Diaminopropane, N, N'-dimethyl-1,3-diaminopropane, N-methyl-1,3-diaminopropane, N, N, N ', N'-tetramethyl-1,3-diamino-1- Methylpropane, N, N, N ′, N′-tetramethyl-1,3-diamino-2-methylpropane,
N, N, N ', N'-tetramethyl-1,4-diaminobutane, N, N, N', N'-tetramethyl-1,5-
Diaminopentane and the like. Preferred diamine compounds for the present invention are those in which the alkylene group connecting the two nitrogen atoms has 2 or 3 carbon atoms. The use amount of these diamine compounds is not particularly limited, but is usually used in the range of 0.01 mol to 10 mol per 100 mol of the phenolic compound.

The following components can be added to the catalyst component as a more preferred embodiment for the present invention. That is, when (a) at least one monoamine selected from a secondary aliphatic amine, an N-hydrocarbon-substituted aniline, and an N- (substituted or unsubstituted phenyl) alkanolamine is further added to the catalyst, When a bromine compound or a chlorine compound is added, (c) when sulfonic acid or a salt thereof is added, and (d) when a tertiary monoamine is added. (A) (b) to a catalyst consisting of (a) and (b)
(C) and (d) may be added alone or in combination of two or more. That is, [(a), (b)] +
(A), [(a), (b)] + (b) [(a), (b)]
+ (C), [(a), (b)] + (d), [(a),
(B)] + (b) + (b), [(a), (b)] + (b)
+ (C), [(a), (b)] + (a) + (d),
[(A), (b)] + (b) + (c), [(a),
(B)] + (b) + (d), [(a), (b)] + (c)
+ (D), [(a), (b)] + (a) + (b) +
(C), [(a), (b)] + (b) + (b) +
(D), [(a), (b)] + (b) + (c) +
(D), [(a), (b)] + (a) + (b) + (c)
+ (D).

As examples of (a), examples of the secondary aliphatic amine include dimethylamine, diethylamine, di-n
-Propylamine, di-iso-propylamine, di-
n-butylamine, di-iso-butylamine, di-t
tert-butylamine, dipentylamines, dihexylamines, dioctylamines, didecylamines,
Examples include dibenzylamines, methylethylamine, methylpropylamine, methylbutylamine, cyclohexylamine and the like. N- (substituted or unsubstituted phenyl)
Examples of the alkanolamine include N-phenylmethanolamine, N-phenylethanolamine, N-phenylpropanolamine, N- (m-methylphenyl) ethanolamine, N- (p-methylphenyl) ethanolamine, and N- (2 ', 6'-dimethylphenyl) ethanolamine, N- (p-chlorophenyl) ethanolamine and the like. Examples of the N-hydrocarbon-substituted aniline include N-ethylaniline, N-butylaniline, N-methyl-2-methylaniline, N-methyl-2,6-dimethylaniline, diphenylamine and the like. Is not limited. These monoamine compounds may be used alone or as a combination of two or more of them. The amount used is not particularly limited, but is in the range of 0.05 to 15 mol, preferably 0.1 to 100 mol, per 100 mol of the phenolic compound.
The range is from 10 to 10 mol.

The bromine compound or chlorine compound of (b) is not particularly limited, and any conventionally known bromine compound or chlorine compound can be used. For example, hydrogen bromide, hydrogen chloride, sodium bromide, sodium chloride, potassium bromide, potassium chloride, tetramethylammonium chloride, tetramethylammonium chloride, tetraethylammonium bromide, tetraethylammonium chloride, trioctylmethylammonium chloride, chloride Cetyltrimethylammonium and the like. These can be used as an aqueous solution or a solution using an appropriate solvent. These bromine compounds or chlorine compounds may be used alone or as a combination of two or more. The amount of use is not particularly limited, but is in the range of 0.5 to 20 mol, preferably about 1 to 10 mol, per mol of copper used.

The sulfonic acid or salt thereof of (c) includes, for example, benzenesulfonic acid, 2-methylsulfonic acid,
3-methylsulfonic acid, p-toluenesulfonic acid, 2,
6-dimethylbenzenesulfonic acid, 2,4-dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid (2-mesitylenesulfonic acid), 2,4,5-
Acids such as trichlorobenzenesulfonic acid, 3-nitrobenzenesulfonic acid, 1-naphthalenesulfonic acid, and 2-naphthalenesulfonic acid and their corresponding salts (sodium salt,
Potassium salt, ammonium salt and the like), sodium bis (2-ethylhexyl) sulfosuccinate and the like. These sulfonic acids or salts thereof may be used alone or as a combination of two or more of them. The amount of use is not particularly limited, but is in the range of 0.5 to 20 mol, preferably 1 to 10 mol, per mol of copper used.
It is used on a molar basis.

The tertiary monoamine (d) is an alicyclic 3
It is an aliphatic tertiary amine including a tertiary amine. For example, trimethylamine, triethylamine, tripropylamine, tributylamine, triisobutylamine, dimethylethylamine, dimethylpropylamine, allyldiethylamine, dimethyl-n-butylamine, diethylisopropylamine, N-methylcyclohexylamine and the like can be mentioned. These tertiary monoamines may be used alone or as a combination of two or more of them. The amount of these is not particularly limited,
Usually 0.1 to 1 per 100 mol of phenolic compound
It is used in a range of 0 mol.

The solvent used in the present invention is not particularly limited as long as it has a polymerization activity. Typically, the solvent contains one or more of the following solvents. Methanol, ethanol, n-propanol, is
alcohols such as o-propanol, n-butanol, iso-butanol, sec-butanol, n-pentanol, n-hexanol, allyl alcohol, benzene, toluene, xylene (each isomer of o-, m- and p-) Aromatic hydrocarbons such as ethylbenzene and styrene, halogenated hydrocarbons such as chloroform, methylene chloride, 1,2-dichloroethane, chlorobenzene and dichlorobenzene, nitro compounds such as nitrobenzene, pentane, hexane, heptane and cyclohexane And aliphatic hydrocarbons such as cycloheptane, esters such as ethyl acetate and ethyl formate, ethers such as tetrahydrofuran and diethyl ether, and dimethyl sulfoxide. Among them, preferred are alcohols having 6 or less carbon atoms, xylene, and toluene.

The alkylphenol in the present invention is a by-product produced when 2,6-dimethylphenol is produced, and typical examples thereof include orthocresol, orthoethylphenol, metacresol, paracresol, 2,4,4 Examples thereof include those composed of any one or more of 6-trimethylphenol. There is no particular limitation on the type of polymerization. By selecting the ratio of a good solvent to a poor solvent with respect to polyphenylene ether, which is a polymer obtained by oxidative polymerization of 2,5-dimethylphenol, a solution polymerization method can be achieved, and as the reaction proceeds, the polymer is added to the reaction solvent. It is also a precipitation polymerization method that precipitates as particles.

The present invention can be applied to any of batch polymerization, continuous polymerization, solution polymerization, and precipitation polymerization. A surfactant can be added to the polymerization reaction system for the purpose of improving phase separation between solvents and improving activity. Alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal alkoxides, neutral salts such as magnesium sulfate, 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 selectivity of the reaction may be reduced.
It is in the range of ° C. 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 polymerization reaction is normal pressure, but it can be used under reduced pressure or under increased pressure as needed.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail by way of examples, but the present invention should not be limited by these examples. In the polymerization of 2,6-xylenol, oxygen is consumed as the polymerization proceeds. The change with time of the oxygen consumption was tracked using a gas burette, and the total value of the oxygen volume consumed 2 hours after the start of the polymerization was measured.
The polymerization activity was evaluated by a numerical value obtained by converting the measured value into a standard state volume.

[0021]

Example 1 30 g of 2,6-dimethylphenol and n-
Add 50 ml of hexane to a 200 ml flask and add 40 ml
Stirring was continued while warming to ° C. After all the 2,6-dimethylphenol was dissolved, the mixture was cooled to 0 ° C in a refrigerator. Two hours later, crystals of 2,6-dimethylphenol were precipitated in the flask, and were separated by filtration. The same operation was repeated using the thus obtained 2,6-dimethylphenol crystals. The 2,6-dimethylphenol obtained by the above operation was analyzed by gas chromatography. 10.0000 g of 2,6-dimethylphenol crystals obtained by the above-described purification operation were precisely weighed and placed in a sample bottle.
A sample which was completely dissolved by adding 1,4-dioxane to a concentration of 0% by weight was used as a measurement sample. A GC-14B manufactured by Shimadzu Corporation was used as an analyzer for gas chromatography, and a column with an inner diameter of 3.2 mm and a length of 5 m filled with Silicone0V-101 manufactured by Nippon Chromatography Co., Ltd. was used as a column. A mixed gas of nitrogen, argon, and helium was used as a carrier gas. The temperature of the sample inlet was 200 ° C., and the temperature of the column was 115 ° C. for 35 minutes from the time of injection of the measurement sample.
The temperature was increased to 130 ° C. at a rate of 1 ° C./min. Each component contained in the measurement sample was detected by the flame ionization detection method, and was prepared using a calibration curve showing the relationship between the peak area and the composition ratio caused by an alkylphenol other than 2,6-dimethylphenol prepared in advance. -The composition of other alkylphenols contained in dimethylphenol was determined. As a result, the total composition of other alkylphenols contained in the purified 2,6-dimethylphenol is 10%.
It was found to be less than ppm. The other alkylphenol referred to herein specifically refers to orthocresol, metacresol, paracresol, orthoethylphenol, and 2,4,6-trimethylphenol. In addition,
When 2,6-dimethylphenol was analyzed by gas chromatography before performing the above purification operation,
0.30% by weight of another alkylphenol was detected. Polymerization was performed using pure 2,6-dimethylphenol obtained by the above purification operation. That is, 4.00 g (32.7 mmol) of pure 2,6-dimethylphenol obtained by the above operation and 26.86 g of toluene were added to a 200 ml four-necked flask containing a magnetic stir bar and completely dissolved. Then, 3.0 g of powdered anhydrous calcium sulfate was further added. Further, 0.0012 g (0.0056 mmol) of cupric bromide and 0.1902 g (1.64 mmol) of N, N, N'-trimethyl-1,3-diaminopropane were added to the equal-pressure dropping funnel and completely added. After dissolution, 8.9521 g of toluene was added and mixed well. The dropping funnel containing the prepared catalyst solution was attached to the preceding 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 solution composition immediately after mixing is as follows. That is, 2,6-dimethylphenol in the mixture is 10% by weight, copper is 0.017% by mole based on the number of moles of 2,6-dimethylphenol, and N, N, N'-trimethyl-
1,3-Diaminopropane is 5.0 mol% based on the number of moles of 2,6-dimethylphenol. The temperature of the polymerization solution was controlled at 40 ° C. The oxygen absorption with respect to the polymerization time was measured with a gas burette, and the total oxygen absorption consumed in 2 hours after the initiation of the polymerization was measured. The total oxygen absorption thus obtained was 290 ml in a standard state.

[0022]

Example 2 Polymerization was carried out using the same 2,6-dimethylphenol used in the polymerization experiment of Example 1.
That is, 200ml with magnetic stir bar
4.00 g of pure 2,6-dimethylphenol obtained by the purification procedure described in Example 1
(32.7 mmol), 16.11 g of toluene, 5.37 g of n-butanol and 5.37 g of methanol were added and completely dissolved. In addition, 0.00095 g (0.0056 mmol) of cupric chloride dihydrate and 1.790 g of methanol were added to an equal-pressure dropping funnel and completely dissolved, and then N, N, N prepared in another container was used. ', N'-tetramethyl-1,3-diaminopropane 0.1902 g (1.
(64 mmol), 5.371 g of toluene and 1.790 g of n-butanol were added and mixed well. The dropping funnel containing the prepared catalyst solution was attached to the preceding four-necked flask, and the remaining opening was equipped with a cooling tube, a thermometer, and an oxygen introducing tube with a valve. A gas burette, a manometer, for measuring the oxygen absorption at the upper port of the cooling pipe,
Connected to a valved oxygen outlet. 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. Close the oxygen inlet valve and the oxygen outlet valve and wait until they are stable.
The catalyst solution was added into the flask at once from the dropping funnel, and polymerization was started with vigorous stirring. The composition of the mixed solution immediately after mixing is as follows. That is, 2,6 in the mixture
-Dimethylphenol is 10% by weight, and the solvent weight ratio is toluene: n-butanol: methanol = 60: 20: 20.
Wherein copper is 0.017 mol% based on the number of moles of 2,6-dimethylphenol, and N, N,
N ', N'-tetramethyl-1,3-diaminopropane is 5.0 based on the number of moles of 2,6-dimethylphenol.
Mol%. The polymerization solution temperature was controlled at 40 ° C. The amount of oxygen absorbed for the polymerization time was measured with a gas buret,
After the start of the polymerization, the total amount of absorbed oxygen consumed for 2 hours was measured. The total oxygen absorption thus determined was 283 ml in a standard state.

[0023]

Example 3 In Example 2, N, N, N ', N'-tetramethyl-1,3-diaminopropane was replaced by N, N,
N'-trimethyl-1,3-diaminopropane 0.19
Example 2 was repeated except that 02 g (1.64 mmol) was used. Total oxygen absorption is 112m in standard condition
l.

[0024]

Example 4 The procedure of Example 2 was repeated, except that 0.0012 g (0.0056 mmol) of cupric bromide was used instead of cupric chloride dihydrate. The total oxygen absorption was 195 ml under standard conditions.

[0025]

[Comparative Example 1] 0.1 to 2,6-dimethylphenol.
The procedure was as in Example 1, except that unpurified 2,6-dimethylphenol containing 30% by weight of another alkylphenol was used in place of the purified 2,6-dimethylphenol. Total oxygen absorption is 237m in standard condition
l.

[0026]

Comparative Example 2 A mixture of purified 2,6-dimethylphenol and 0.50% by weight of orthocresol based on 2,6-dimethylphenol was added to purified 2,6-dimethylphenol.
Example 1 except that dimethylphenol was used in place of
The same was done. Total oxygen absorption is 204ml in standard condition
Met.

[0027]

Comparative Example 3 Purified 2,6-dimethylphenol to which 0.30% by weight of orthocresol was added to 2,6-dimethylphenol was added to purified 2,6-dimethylphenol.
-As in Example 2, except that dimethylphenol was used instead. Total oxygen absorption is 21 at standard condition
It was 7 ml.

[0028]

[Comparative Example 4] 0.2% against 2,6-dimethylphenol.
The procedure was as in Example 3, except that unpurified 2,6-dimethylphenol containing 30% by weight of another alkylphenol was used in place of the purified 2,6-dimethylphenol. Total oxygen absorption is 91ml in standard condition
Met.

[0029]

[Comparative Example 5] 0.2% against 2,6-dimethylphenol.
The procedure was as in Example 3, except that unpurified 2,6-dimethylphenol containing 30% by weight of another alkylphenol was used in place of the purified 2,6-dimethylphenol. Total oxygen absorption is 179m in standard condition
l.

[0030]

According to the method of the present invention, since high-purity 2,6-dimethylphenol from which other alkylphenols contained in 2,6-dimethylphenol are removed is used, the amount of catalyst used is small. As a result, the amount of the solvent used in the step of removing the residual catalyst from the polymer can be reduced. 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. Further, the process according to the present invention has a very high polymerization activity and can realize a highly efficient productivity.

Claims (4)

[Claims] 1. A process for producing polyphenylene ether by oxidative polymerization of 2,6-dimethylphenol in a solvent using a catalyst and oxygen to reduce the content of other alkylphenol contained in 2,6-dimethylphenol to 0. 3
A method for producing polyphenylene ether, which is less than 0% by weight. 2. The method for producing polyphenylene ether according to claim 1, wherein the alkylphenol is any one or more of orthocresol, orthoethylphenol, metacresol, paracresol, and 2,4,6-trimethylphenol. 3. The catalyst to be used is (a) a copper compound and (b) a compound represented by the following formula (1). 2. The method for producing polyphenylene ether according to claim 1, wherein a catalyst comprising a diamine compound having the following structure is used. 4. The method for producing polyphenylene ether according to claim 3, wherein the amount of the copper compound is 0.3 mol% or less as copper relative to 2,6-dimethylphenol.