JPS62172024A - Production of polyphenylene ether - Google Patents

Abstract

PURPOSE:To obtain the titled ether having improved powder properties, by subjecting a phenol to oxidation polymerization in the presence of an aromatic hydrocarbon solvent and a complex catalyst, decomposing the catalyst in the prepared polymerization reaction solution, subjecting the solution solid-liquid separation and introducing an inert gas to water dispersion. CONSTITUTION:(C) A phenol is subjected to oxidation polymerization by the use of (A) an aromatic hydrocarbon solvent (or mixed solvent of it and an alcohol) in the presence of (B) a complex catalyst containing copper, manganese or cobalt. The prepared polymerization reaction solution is brought into contact with (D) a catalyst decomposing agent (and reducing agent) and, if necessary, (E) an alcohol is added to the solution to form precipitate, the solution is subjected to solid-liquid separation, the separated wet solid is incorporated with water to form water dispersions and an inert gas is introduced to the water dispersions in a treating tank wherein the top part is heated at higher temperature than the bottom part to give the aimed polyphenylene ether.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application) The present invention relates to a method for stably searching for and producing polyphenylene ether having good powder properties and little catalyst residue.

(Prior Art) Polyphenylene ether is generally prepared using an aromatic hydrocarbon solvent or a mixed solvent of an aromatic hydrocarbon and an alcohol.
It is obtained by oxidative polymerization of phenols in the presence of a complex catalyst containing steel, manganese, or cobalt. However, in the polymer liquid, there are quite a few impurities that inhibit the properties of polyphenylene ether, such as catalyst residue and by-product diphenoquinone, and in order to remove these impurities, it is generally brought into contact with a catalyst decomposer or a reducing agent. A method such as cleaning with a large amount of alcohol is used.

However, this method requires the use of a large amount of alcohol, which increases the cost of alcohol recovery.Furthermore, since the polyphenylene ether particles obtained in this way are extremely fine, problems such as scattering occur during the drying and transportation process, causing special problems. This can cause many troubles due to poor supply from the hopper and poor biting into the granulator during molding.

As a method for obtaining polyphenylene ether with less catalyst residue by reducing the amount of alcohol used, polyphenylene is dissolved in an organic solvent that is substantially incompatible with water and that dissolves or swells polyphenylene ether, such as a mixed solvent of benzene and butanol. There is a method in which impurities contained in the polymer are transferred to the aqueous phase and removed by adding ether to form a solution or dispersion and bringing this into contact with water.

However, the polyphenylene ether obtained by this method is 1
These are fine particles containing 40% or more of particles with a size of 00μ or less.

As a method for improving the powder properties of polyphenylene ether, there is a method of suppressing the formation of fine particles by allowing water to coexist when adding alcohol to the polymer liquid (Japanese Patent Application Laid-open No. 5-1111)
4-146896). However, the particles formed by this method are relatively brittle and have many disadvantages, such as the tendency to become fine particles during the slurry transportation process using a pump, the solid-liquid separation process using a centrifuge, etc., or the drying process.

Alternatively, a polyphenylene ether wet solid containing 5 to 500% organic solvent on a dry basis may be prepared in an aqueous dispersion.
There is a method of obtaining polyphenylene ether powder with a low content of fine particles by heat treatment at 0°C to 150°C (Japanese Patent Application Laid-Open No.
8-73451).

However, in order to stably obtain the desired polyphenylene ether, it is necessary to reduce the amount of organic solvent contained in the wet solid, and to obtain such a wet solid, it is necessary to increase the amount of alcohol used. .

Furthermore, if a wet solid is obtained by using less alcohol, lumps may form during the heat treatment step, making operation impossible, and polyphenylene ether with many coarse particles tends to form, making it difficult to produce stably. .

(Summary of the Invention) As a result of extensive studies, the present inventors have found a method that can completely solve the above problems, and have now provided the present invention.

That is, the present invention involves oxidative polymerization of 7 enols in the presence of a complex catalyst containing copper, manganese, or cobalt using an aromatic hydrocarbon solvent or a mixed solvent of aromatic hydrocarbon and alcohol, and the resulting polymerization. The reaction solution is brought into contact with a catalyst decomposition agent or a catalyst decomposition agent and a reducing agent, and alcohol is added as necessary to form a precipitate, followed by solid-liquid separation, and water is added to the separated wet solid for water dispersion. form a liquid,
By blowing an inert gas into the aqueous dispersion in a treatment tank in which the upper part is heated to a higher temperature than the lower part, the solvent and catalyst residue contained in the aqueous dispersion are efficiently removed, resulting in less catalyst residue and fine particles. The purpose of the present invention is to provide a method for stably producing polyphenylene ether with improved powder properties and a high bulk density.

(Specific Description) The phenol compound according to the present invention has the general formula (wherein, X is a hydrogen atom, a chlorine atom, a bromine atom, and an iodine atom. and a monovalent substituent selected from halogenated alkyl groups and halogenated alkoxy groups having at least 2 carbon atoms between R2 and the phenol nucleus; Each of the selected IIJ and Ra is 1 selected from the groups and hydrogen atoms listed for R2.
member. ) It is a phenolic monomer having the structure shown below.

Specifically, 2.6-dimethylphenol, 2.6-dinitylphenol, 2.6-dimethylphenol, 2.
, 6-dilaurylphenol, 2,6-dipropylphenol, 2,6-diphenylphenol, 2,6-simethoxyphenol, 2,3.6-)limethylphenol, 2,3.5.6-titra Methylphenol, 2.6
-ethoxyphenol, 2-ethyl-4-stearyloxyphenol, 2,6-di(chlorophenoxy)phenol, 2,6-dimethyl-3-chlorophenol,
2.6-shimef-4-chlorophenol, 2.6-j
) thyl-3-chloro-5-bromophenol, 2.6-
Cy(chloroethyl)phenol, 2-methyl-6-butylphenol, 2-methyl-6-phenylphenol, 2,6-dibenzylphenol, 2,6-ditolylphenol, 2,6-cy(chloroethyl)phenol ,
Examples include 3-methyl-6-tert-butylphenol. Each of these can be used alone, or can be used together with Ike no Fe and a nol-based monoclear substance to produce Kyodogogai.

Among these, 2,6-dimethylphenol is particularly preferred.

In the polymerization reaction solution of the present invention, phenols are mixed with oxygen or oxygen in an aromatic hydrocarbon solvent or a mixed solvent of an aromatic hydrocarbon solvent and an alcohol in the presence of a complex catalyst containing copper, manganese, or cobalt. Obtained by reacting with gas.

As a catalyst, a commercially available catalyst can be used. For example, as a complex catalyst containing copper, Japanese Patent Publication No. 36-18692, Japanese Patent Publication No. 40-13423, Japanese Patent Publication No. 49-490, etc. Examples of complex catalysts containing manganese include JP-B No. 40-30354, JP-B No. 47-5111, JP-A-56-32523, -
Examples include catalysts disclosed in Japanese Patent Publication No. 58-19329, and examples of complex catalysts containing cobalt include those disclosed in Japanese Patent Publication No. 45-2355.
Examples include catalysts such as No. 5.

As the solvent, for example, an aromatic hydrocarbon solvent alone such as benzene, toluene, xylene, etc., or a mixed solvent of these aromatic hydrocarbon solvents and an alcohol such as methanol, ethanol, inglobanol, etc. is used. The molecular weight of polyphenylene ether can be controlled arbitrarily by the reaction (11 degrees), reaction time, catalyst conditions, solvent type, and solvent composition. It helps to make it contain ether and make it pay for it.

In the present invention, the intrinsic viscosity is measured in chloroform at a temperature of 30°C.

Depending on the solvent used in the polymerization, the polymerization reaction solution may be in the form of a so-called slurry in which polyphenylene ether particles are dispersed.
Alternatively, it becomes a solution state in which polyphenylene ether is dissolved.

Generally, the volume ratio of aromatic hydrocarbon to alcohol is 65.
/35 or less, it can be obtained in a slurry state.

The nonapolymerization reaction solution obtained in a slurry cap is contacted with a catalyst decomposition agent, or a catalyst decomposition agent and a reducing agent, and then subjected to solid-liquid separation using, for example, a mouth filter or a centrifugal separator.

The polymer liquid obtained in solution form 1 is brought into contact with a catalyst decomposition agent, or a catalyst decomposition agent and a base material, and alcohol is added so that the volume ratio of aromatic hydrocarbon to alcohol is 65/35 or less to form polyphenylene. After precipitating the ether+
Separate S' at night.

Examples of catalyst decomposition agents include acids such as hydrochloric acid and acetic acid, and chelating agents such as ethylenediaminetetraacetic acid disodium dihydrate and ethylenediaminetetraacetic acid tetrasodium tetrahydrate.As reducing agents, sodium sulfite, Sodium dithionate and the like can be used.

Whether the catalyst decomposer is brought into contact alone or a combination of the catalyst decomposer and the reducing agent is brought into contact is determined depending on the amount of diphenoquinone, which is a by-product, contained in the polymer liquid. Specifically, if the amount of diphenoquinone is 0.1 f% or less based on polyphenylene ether, the catalyst decomposer is brought into contact with the catalyst, but if it exceeds 0.1%, the catalyst decomposer is brought into contact with the catalytic decomposer. It is whispering that the base agents may come into contact with each other.

When using a catalyst decomposition agent, it is desirable that the pH in the polymer liquid is 7 or less, and when using a chelating agent, it is desirable to keep the pH of the copper, manganese, or cobalt used. It is desirable that the molar ratio is in the range of 1 to 10.

The amount of reducing agent is determined depending on the size of the diphenoquinone and is generally in the range of 1 to 10 molar ratios.

The temperature and time of contact are arbitrary, but generally the blackness (
d20°C to 100°C, time is 0.5 to 5.0, about Terama.

The polyphenylene ether separated into solid and liquid in this manner is a so-called wet solid containing a solvent.

Water is added to the wet solid to form an aqueous dispersion, and an inert gas blowing treatment is performed in a treatment tank.

The processing tank has an external heating means such as a steam jacket, and is configured such that the upper part of the processing tank is heated more strongly than the lower part. That is, the water molecules l of the polyphenylene ether wet solid
! The upper part of the Li surface is heated strongly so that the temperature of the gas phase at the upper part of the aqueous dispersion becomes higher than the temperature of the aqueous dispersion.

The amount of water in the aqueous dispersion is preferably 1 to 10 times that of the wet solid.

After the aqueous dispersion is formed, an inert gas is blown into the liquid phase at a temperature of 30°C to 150°C, preferably 40°C to 100°C.

If the temperature of the liquid phase is below 30°C, the desolvation effect will be small, and 1
A temperature of 50° C. or higher is not preferable because it tends to cause lumps, making operation impossible, or resulting in a polyphenylene ether with many coarse particles.

It is necessary to heat the aqueous dispersion in the treatment tank so that the upper part of the surface of the aqueous dispersion is higher than the lower part of the liquid. If the temperature of the upper part is lower than that of the liquid phase, the solvent will not be effectively removed. Furthermore, reflux of the solvent occurs in the gas phase, which tends to cause polyphenylene ether to adhere to the walls of the stirring tank, which is undesirable as it causes the formation of coarse particles.

The inert gas blown into the water dispersion system may be nitrogen, argon, helium, or the like, and any of them can be used. The amount of inert gas blown was 0.01 cyr/in superficial velocity.
Speeds of see ~10 cm/see are common.

A superficial velocity of 0.01 on7 sec or less will have little desolvation effect, and a superficial velocity of 10 an7 sec or more will cause entrainment of polyphenylene ether, which is not preferable.

The inert gas is preferably blown in such a way as to disperse the gas as much as possible, for example from the bottom of the stirring tank.

The inert gas blowing is continued until the amount of solvent in the wet solid after solid-liquid separation of the desolvated aqueous dispersion is preferably 100% by weight or less, and 80% by weight or less on a dry weight basis. If it exceeds 100% by weight on a dry basis, the particles become sticky and may clog the centrifuge cloth.
This causes lumps to form during the drying process.

The blowing of inert gas not only effectively removes the solvent, but also has the effect of efficiently extracting catalysts such as paulownia, manganese, and cobalt contained in polyphenylene ether into water.

The polyphenylene ether particles in the aqueous dispersion thus obtained have a uniform particle size, both fine particles and coarse particles, and are hard.

The aqueous dispersion is subjected to solid-liquid separation using a filter, centrifuge, etc., and then dried using a vacuum dryer, fluidized fluid dryer, rotary dryer, etc.

The thus prepared polyphenylene ether powder can be used as a water dispersion system! 4 Keeping the recognized particle properties as they are, 100
It has a uniform particle size, containing almost no particles of less than μ or more than 2000μ, and has a bulk density of o, 4ot/-
This is the powder described above. It is also a polyphenylene ether powder with a copper, manganese, and cobalt content of 10 ppm or less, with little catalyst residue.

The present invention will be described below with reference to specific examples, but these are merely one embodiment of the present invention and are not intended to be limiting.

Example-1 A jacketed autoclave with a capacity of 1 i o at equipped with a stirrer, a thermometer, a condenser and an air inlet tube was equipped with 2
,6-xylenol 12.217 kg (100 mol)
, 41.61 tons of xylene and 11.4 tons of methanol to make a homogeneous solution, and then 240 tons of sodium hydroxide.
y (6,0 mol), piperidine 127.8t (1,
5 mol), Eriofrom Black T (Gyudon Chemicals■
55.4 P (0.12 moles) and 9.9 r (0.05 moles) of manganese chloride tetrahydrate were each added as a solution dissolved in methanol lt. The volume ratio of xylene and methanol at this time is 73.0/
It is 27.0.

Next, while stirring the inner crops vigorously, the air was pumped to 50-a/
Bubbling was carried out into the reaction mixture at a rate of min. The reaction temperature and pressure were maintained at 30°C and 9/-, respectively. After 6 hours had passed since the start of air blowing, the supply of air was stopped (7 hours). At this time, the polymer liquid was in a solution state. Part of the polymer liquid was extracted and the polymer was dissolved in a small amount of methanol. The intrinsic viscosity of the precipitate was 0.49 s dt/t when it was filtered and dried.
When the amount of diphenoquinone was measured at a wavelength of 420 nm in V measurement 4, it was found to be 0.01% or less.

This polymer; acetic acid soo at night? (x moles) and 30℃
After 1 hour of treatment, 37 ml of methanol was added to form a precipitate. Thereafter, the liquid was separated using a basket centrifuge to obtain wet solid No. 29. The amount of solvent in the wet solid was 130% on a dry basis.

Stirrer, thermometer, condenser, nitrogen introduced from the bottom of the tank - α, liquid phase jacket and gas phase jacket -
29 mL of wet solid and 50 AiJ of water were introduced into the obtained 200 mm of internal diameter 60 cm with stirring to form an aqueous dispersion. The temperature of the t'&[ phase was maintained at 70°C, the τ temperature of the gas phase was maintained at 80°C, and nitrogen was added at 707°C. /min, superficial velocity 0.4
1 cm7 sec) for 4 hours.

After 4 hours had passed, the nitrogen blowing was stopped. The aqueous dispersion was extracted, and the liquid was separated using a basket centrifuge to obtain wet solid No. 9 at 19.7.

The wet solid solvent 1 had been reduced to 70% on a dry basis.

This wet solid was dried at a temperature of 150°C using a vacuum dryer.
Dry for 2 hours, polyphenylene ether powder 11.6
# is good.

The particle size of the powder thus obtained was measured using a vibrating sieve. The 50% weight average diameter was 580μ, 0.5% for 100μ or less, and 0.3% for 2000μ or more, indicating that the powder had a uniform particle size.

Moreover, the bulk density was 48y/-. The manganese content of this powder was 2 ppm.

Comparative Example-1 Example-1 except that when treating the water-grazing liquor in Actual Leakage Example-1, the temperature of the gas phase was set 10°C lower than the temperature of the liquid phase, and the nitrogen blowing time was 8 hours. I did the same thing.

When the aqueous dispersion was extracted and the inside of the tank was observed, a large amount of deposits were present at the interface between the gas phase and the liquid phase.

Solid-liquid separation was performed in the same manner as in Example 1, and the wet solid was 17.7 cod. Although the amount of solvent in the wet solid was reduced to 70% on a dry basis, the nitrogen blowing time was about twice as long as in Example 1, indicating that the wet solid was not efficiently desolvated. Polyphenylene ether powder was obtained by drying in the same manner as in Example 1. The particle size of the powder thus obtained was 2000μ or more.
It was a very serious particle containing 2%. The manganese content of this polymer was 8 ppm.

Comparison Example 2 The pond in which 9 elements were not blown in Example 1 was treated in the same manner as in Example 1.

Approximately 1 hour after starting the water f+keiya ('& process), the agitator was started and the construction was stopped.After the tank was stopped, a large lump was found on the stirring blade. There were a lot of particles with a diameter of about 3 mm.

After a portion was extracted, solid-liquid separated, and dried, the manganese content (1) was measured and found to be 18 ppm.

Example-2 In the same autoclave as in Example-1, 2,6-xylenol xz, zx7 kg (1,00 mol), and benzene 24
1 and 15.6 t of methanol were added to form a homogeneous solution, and then the same catalyst as in Example-1 was added in the same manner as in Example-1. The ratio of the volumes of benzene and methanol at this time is 55. /'45.

Then, while stirring the contents vigorously, oxygen was added at 8t/m.
Begin bubbling into the reaction mixture at a rate of in. The reaction temperature and pressure were maintained at 50° C. and xky/*, respectively. 6 hours after the start of oxygen injection, l!
The supply of raw materials has been stopped. At this time, the electric combination liquid was in a slurry state. A portion of the polymer liquid was taken out and dried, and the intrinsic viscosity was measured and found to be 0.465. Further, the amount of diphenoquinone was determined in the same manner as in Example 1 and was found to be 0.01% or less. Add 600F acetic acid to this polymer liquid.
(1 mol) was added and treated at 50° C. for 1 hour, and then the liquid was separated using a basket centrifuge to obtain a wet solid of 28.2 mm. The amount of solvent in the wet solid is 138% on a dry basis.
Met.

Into the same 2001 stirring tank as in Example-1, 28.24 wet solids and 50 capes of water were introduced to form an aqueous dispersion. Thereafter, the temperature of the liquid phase was maintained at 60°C and the temperature of the gaseous phase was maintained at 70°C, and nitrogen was introduced at a rate of 70 L/min at a superficial velocity of 0.41 c.
m/see) and continued blowing for 4 hours.

After 4 hours had passed, nitrogen blowing was stopped. Thereafter, the aqueous dispersion was extracted, and the liquid was separated using a basket centrifuge to obtain a wet solid of 19.5A9. The amount of solvent in the wet solids had been reduced to 65% on a dry basis. This wet solid was dried at 130° C. for 12 hours using a vacuum dryer to obtain 11.8 cod polyphenylene ether powders.

The particle size of the powder thus obtained was measured using a vibrating sieve. The 50% weight average diameter was 530μ, 0.8% was 100μ or less, and 0.1% was 2000μ or more, so the powder had a uniform particle size. Moreover, the bulk density was o, sxr/-, and the manganese content was 7 ppm.

Claims (1)

[Claims] Oxidative polymerization of phenols in the presence of a complex catalyst containing copper, manganese or cobalt using an aromatic hydrocarbon solvent or a mixed solvent of aromatic hydrocarbon and alcohol,
The obtained polymerization reaction liquid is brought into contact with a catalyst decomposition agent or a catalyst decomposition agent and a reducing agent, and if necessary, alcohol is added to form a precipitate, followed by solid-liquid separation, and water is added to the separated wet solid. 1. A method for producing polyphenylene ether, which comprises: forming an aqueous dispersion, and blowing an inert gas into the aqueous dispersion in a treatment tank in which the upper part is heated to a higher temperature than the lower part.