CN100422237C - The preparation method of polyphenylene ether - Google Patents

Abstract

After passing oxygen-containing gas into the polymerization solution composed of a good solvent of polyphenylene ether, metal salt, amine compound and phenol compound to oxidize and polymerize the phenol compound, mix a chelating agent aqueous solution in the polymerization solution to stop the polymerization, and separate the metal salt , a chelating agent, and a polyphenylene ether solution obtained by adding a poor solvent of polyphenylene ether to precipitate polyphenylene ether particles, and filtering it to prepare polyphenylene ether, which is characterized in that the polyphenylene ether particles are filtered to obtain When the obtained mixed solution is distilled to recover the good solvent, one or more antifoaming agents selected from fluorosilicone compound-based antifoaming agents are used.

Description

The preparation method of polyphenylene ether

technical field

The invention relates to a method for preparing polyphenylene ether. In a polymerization solution composed of a good solvent, a metal salt, an amine compound and a phenol compound, an oxygen-containing gas is passed through to oxidize and polymerize the phenol compound to obtain polyphenylene ether. The polymerization is stopped by mixing the chelating agent aqueous solution, and the poor solvent of polyphenylene ether is added to the polyphenylene ether solution obtained by separating the metal salt, the chelating agent, and water to precipitate polyphenylene ether particles, and the good solvent can be recovered effectively.

Background technique

The polyphenylene ether resin composition using polyphenylene ether as a raw material can be used to produce products and parts of the desired shape by molding methods such as melt injection molding or melt extrusion molding. Plastic materials that are widely used as materials for products and components in various other industrial materials fields.

As the preparation method of polyphenylene ether, there is the following method: pass oxygen-containing gas into the polymerization solution composed of good solvent, metal salt, amine compound and phenol compound to oxidize and polymerize the phenol compound to obtain polyphenylene ether, then in the polymerization solution Mix the chelating agent aqueous solution to stop the polymerization, add the poor solvent of polyphenylene ether to the polyphenylene ether solution obtained by separating the metal salt, chelating agent, and water, precipitate polyphenylene ether particles, filter and dry the polyphenylene ether to prepare polyphenylene ether .

In the production method of polyphenylene ether, as a means of recovering a good solvent and a poor solvent from the mixed solution obtained by filtering polyphenylene ether particles, for example, there is a method in which toluene is used as a good solvent and methanol is used as a poor solvent. Mix an appropriate amount of water in the mixture, separate it into a good solvent phase composed of a good solvent and a water phase composed of a poor solvent and water, separate the two phases, distill the good solvent phase to recover the good solvent, and distill the water phase And recovery of poor solvent.

In this recovery method, when methanol is recovered by distilling the water phase, by adding alcohol-based, glycerin-based, or silicone-based antifoaming agents alone or in combination, the foaming in the distillation tower can be suppressed, and effective for recycling purposes.

However, even if a so-called effective antifoaming agent is used for distilling general aromatic organic solvents, for example, when a good solvent phase is distilled in the production process of polyphenylene ether, it cannot suppress foaming in the distillation column. Bubbles, good solvents can only be recovered under distillation conditions that take into account the bubbles.

In the industry related to the preparation of polyphenylene ether that needs to recover high-purity good solvents, there is no technology that fully meets the requirements of recovery efficiency and productivity.

Contents of the invention

The purpose of the present invention is to provide a method for preparing polyphenylene ether. Specifically, after passing an oxygen-containing gas into a polymerization solution composed of a good solvent, a metal salt, an amine compound and a phenol compound, the phenol compound is oxidatively polymerized to obtain polyphenylene ether , Mix the chelating agent aqueous solution in the polymerization solution to stop the polymerization, add the poor solvent of polyphenylene ether to the polyphenylene ether solution obtained by separating the metal salt, chelating agent, and water, precipitate polyphenylene ether particles, and filter it to prepare The method of polyphenylene ether, wherein, in the method of recovering the good solvent by distilling the mixed solution obtained by filtering the polyphenylene ether particles, the foaming during distillation can be suppressed, and the recovery efficiency, the purity of the recovered solvent, and the productivity are not affected, and sufficient Meet the requirements of the industry.

In the present invention, in order to achieve the above object, we have devoted ourselves to research and found that after the phenol compound is oxidatively polymerized by passing an oxygen-containing gas into a polymerization solution composed of a good solvent of polyphenylene ether, a metal salt, an amine compound, and a phenol compound, after the polymerization Mix the chelating agent aqueous solution in the solution to stop the polymerization, add the poor solvent of polyphenylene ether to the polyphenylene ether solution obtained by separating the metal salt, chelating agent, and water, precipitate polyphenylene ether particles, and filter it to prepare polyphenylene ether In the method, when the mixed liquid obtained by filtering the polyphenylene ether particles is distilled to recover the good solvent, the foaming during distillation can be effectively suppressed, and the high-purity polyphenylene ether good solvent can be effectively recovered, thereby completing a process that fully meets the needs of the industry. The recovery method of the good solvent in the process of preparing polyphenylene ether required by the industry.

That is to say, the present invention is to pass oxygen-containing gas into the polymerization solution composed of polyphenylene ether good solvent, metal salt, amine compound and phenol compound to oxidize and polymerize the phenol compound, then mix the chelating agent aqueous solution in the polymerization solution to form The method of stopping the polymerization, adding a poor solvent of polyphenylene ether to the polyphenylene ether solution obtained by separating the metal salt, the chelating agent, and water to precipitate polyphenylene ether particles, and filtering it to prepare polyphenylene ether is characterized in that, When recovering the good solvent by distilling the mixed solution obtained by filtering the polyphenylene ether particles, one or more antifoaming agents selected from fluorosilicone compound-based antifoaming agents are used.

Description of drawings

FIG. 1 is a schematic diagram of an Oldershaw type rectification apparatus used in Example 1. FIG.

FIG. 2 is a schematic diagram of a distillation evaluation apparatus used in Example 3. FIG.

Symbols in the figure: A: the extract of the uppermost stage; B: the supply of good solvent phase; C: the extract of the lowermost stage; D: the 20-stage rectification tower (concentration part); E: the 20-stage rectification tower (recovery part ); F: oil bath (set at 160°C); A': 2L cylindrical glass container; B': nitrogen conduit; C': spherical filter (ポルフィルタ one); D': distillation tube; E ′: Thermometer; F′: Cooling tube; G′: Rubber plug; G: Oil bath (set at 100°C); H: Bubble height; a: 300ml of good solvent phase; : bubbling area; d: recovered toluene; e: cold water.

Detailed ways

The polyphenylene ether of the present invention has a main chain structure represented by the following general formula (2).

Formula (2)

In the polyphenylene ether represented by the above general formula (2) of the present invention, R1 and R4 each independently represent hydrogen, primary lower alkyl or secondary lower alkyl, phenyl, aminoalkyl, or alkoxy. R2 and R3 each independently represent hydrogen, primary or secondary lower alkyl, or phenyl.

The good solvent for polyphenylene ether of the present invention is a solvent that dissolves polyphenylene ether well to form a uniform polyphenylene ether solution, preferably at least one solvent selected from benzene, toluene, and xylene.

The metal salt of the present invention is a main catalyst for oxidative polymerization of phenolic compounds.

As the metal salt in the present invention, at least one metal salt selected from copper compounds and manganese compounds is preferably used.

The amine compound of the present invention is a compound that forms a complex with a metal salt and serves as an oxidation polymerization catalyst for a phenol compound.

The amine compound of the present invention is preferably composed of at least one amine compound selected from diamine compounds represented by the following general formula (1), monotertiary amine compounds, and monovalent secondary amine compounds.

Formula (1)

(In the formula, R1, R2, R3, and R4 each independently represent hydrogen, a straight chain or branched chain alkyl group with a carbon number of 1 to 6, but not all of them are hydrogen at the same time. R5 represents a straight chain group with a carbon number of 2 to 5 or an alkylene group containing a methyl branch.)

The phenol compound of the present invention is preferably selected from 2,6-dimethylphenol, 2,3,6-trimethylphenol, 2-methyl-6-butylphenol, 2-methyl-6-ethylphenol , at least one of 2-methyl-6-phenylphenol and 2,6-dichlorophenol.

As the phenol compound of the present invention, 2,6-dimethylphenol is most preferable.

The oxygen-containing gas in the present invention is an oxygen-containing gas such as oxygen or air.

The oxygen-containing gas in the present invention is preferably a gas having an oxygen content of 5% by volume or more.

The polyphenylene ether of the present invention is preferably passed through an oxygen-containing The body is obtained by oxidative polymerization of phenolic compounds.

The reduced viscosity of the polyphenylene ether of the present invention is the reduced viscosity measured at 30° C. using a 0.5 g/dl chloroform solution, preferably in the range of 0.15 to 1.5 dl/g, more preferably in the range of 0.30 to 1.0 dl/g.

In the present invention, in the stage where the polyphenylene ether is oxidatively polymerized to obtain the desired reduced viscosity, the polymerization solution is mixed with an aqueous chelating agent solution to stop the polymerization.

The chelating agent of the present invention is a water-soluble chelating agent, which forms a chelate with the above-mentioned metal salt and effectively removes the metal salt from the polymerization solution.

As the aqueous chelating agent solution of the present invention, an aqueous solution of ethylenediaminetetraacetic acid salt can be preferably used.

As the chelating agent aqueous solution of the present invention, it is more preferable to use a solution selected from ethylenediaminetetraacetic acid tetrasodium salt solution, ethylenediaminetetraacetic acid trisodium salt solution, ethylenediaminetetraacetic acid tetrapotassium salt solution, ethylenediaminetetraacetic acid trisodium salt solution, and ethylenediaminetetraacetic acid trisodium salt solution. More than one kind of potassium salt solution.

The polyphenylene ether solution in the present invention is a polyphenylene ether solution from which the metal salt chelating agent and water have been substantially removed from the polymerization solution.

The polyphenylene ether in the polyphenylene ether solution of the present invention is preferably 10 to 30% by weight relative to the polyphenylene ether solution.

The method for preparing polyphenylene ether of the present invention is to add at least one poor solvent of polyphenylene ether selected from methanol, ethanol, isopropanol, n-butanol, acetone and methyl ethyl ketone to the polyphenylene ether solution to precipitate A method for producing polyphenylene ether by filtering polyphenylene ether particles, characterized in that, when recovering a good solvent by distilling a mixture of filtered polyphenylene ether particles, one or more kinds of antifoaming agents selected from fluorosilicone compounds are used. defoamer.

In the method for producing polyphenylene ether according to the present invention, when recovering the good solvent, it is preferable to add 0.01 to 10 ppm of one or more antifoaming agents selected from fluorosilicone compound-based antifoaming agents with respect to 1 part by weight of the good solvent, more preferably Preferably it is 0.03-7 ppm, particularly preferably 0.05-5 ppm.

As the fluorosilicone compound-based antifoaming agent of the present invention, a fluorosilicone compound in which part or all of the methyl groups of polydimethylsiloxane is substituted with a fluorosilicone group or a perfluoroalkyl group; or a fluorosilicone compound can be preferably used. A mixture of ketone compounds and silicone compounds. As a specific example of the fluorosilicone compound preferably used in the present invention, or a mixture of a fluorosilicone compound and a silicone compound, there is FA630 defoamer manufactured by Shin-Etsu Silicone (Shin-Etsu Silicone) Co., Ltd., Toshiba Silicone (Toshiba Silicone) Silicone) FQF501 defoamer manufactured by the company.

If the mixed liquid of the present invention is distilled directly, foaming will occur in the distillation tower, so it is extremely difficult to effectively recover the good solvent, and there are problems of purity and productivity.

The extremely preferred method of preparing polyphenylene ether in the present invention is to stop the polymerization by contacting with an aqueous solution of a chelating agent, then keep the mixed liquid at 40°C to 120°C until the diphenoquinone produced during polymerization disappears, and then separate the catalyst And the method for preparing polyphenylene ether.

A particularly preferred method for preparing polyphenylene ether in the present invention is to add and mix water in the mixed liquid, separate into a good solvent phase composed of a good solvent and a water phase composed of a poor solvent and water, and after separating them, distill the good solvent Phase to recover good solvent, distilled water phase to recover poor solvent, so as to prepare the method of polyphenylene ether.

Using the method for preparing polyphenylene ether of the present invention can greatly improve the recovery efficiency of the good solvent of polyphenylene ether in the past, and the purity of the recovered good solvent of polyphenylene ether is good, so the equipment required for recovering the solvent can be greatly improved and energy.

[Example]

Hereinafter, the embodiments of the present invention will be specifically described by way of examples. However, the present invention is not limited by the following examples without departing from the scope of the subject matter of the present invention.

Reference example

(A-1): According to the method described in Example 3 of Japanese Patent Laid-Open No. 59-23332, in the presence of each catalyst and di-n-butylamine, while feeding oxygen, add 22% by weight of The toluene solution of 2,6-dimethylphenol, the supply of oxygen was stopped after 100 minutes. An aqueous solution of ethylenediaminetetraacetic acid trisodium salt was added to the polymerization mixture, and the mixture was kept at 70°C for 2 hours. The mixture was sent to a centrifugal separator manufactured by Sharples Co., Ltd., and the catalysts and the aqueous solution phase containing trisodium ethylenediaminetetraacetic acid were separated to obtain a polyphenylene ether solution with a polyphenylene ether content of 22.5% and a specific gravity of 0.894. (A-1).

Afterwards, the height of 95mm from the bottom of the tank to the liquid surface is provided with a discharge port with a diameter of 25mm, and the inner diameter of the precipitation tank is 133mm. Single-stage 4 inclined blades (inclination of 45 degrees, blades, etc.) 33 mm in diameter) was set as a stirring blade precipitation tank, put 370 g of toluene, 420 g of methanol, and 10 g of water, and stirred at a stirring speed of 600 rpm. ) polyphenylene ether solution is added at the diagonal position of the discharge port at a rate of 190 g/min, and a mixture of methanol 97.5 wt% and water 2.5 wt% is added at the same position at a rate of 100 g/min Add to.

The mixed solution overflowing from the discharge port was collected.

The resulting mixed liquid was filtered with a glass filter to obtain a mixed liquid in which polyphenylene ether particles were separated.

The reduced viscosity of the polyphenylene ether in (A-1) measured using 0.5 g/dl of chloroform solution was 0.51 dl/g.

9.2 L of water was added to 100 L of the mixed liquid to separate a good solvent phase composed of a good solvent and an aqueous phase composed of a poor solvent and water to obtain a separated mixed liquid.

The aqueous phase was fractionally distilled from the separated liquid mixture using a centrifugal separator manufactured by Shaples Co., Ltd. to obtain a good solvent phase used in Examples.

[Example 1]

When distillation is performed using a 45 mmφ Oldershaw type fractionation device made of glass with 40 concentration stages as shown in FIG. The solvent phase was distilled.

5 kg of toluene was placed in the liquid storage tank of the lowest stage of the Oldershaw type fractionation apparatus, and the liquid storage tank was heated by an oil bath set at 160°C.

After toluene was distilled off from the uppermost part of the fractionating device, it was cooled and returned to the uppermost stage.

After confirming that the temperature of the gas phase in the uppermost stage is stable to 110°C, supply the good solvent phase with the aforementioned defoamer added at a rate of 2700 g/hour from the position of the upper 20 stages of the fractionating device, and cool the liquid obtained from the gas phase in the uppermost stage Withdraw 10% and return 90% to the uppermost stage.

The lowermost gas phase is cooled and extracted.

Five hours after the start of the supply, the gas phase temperature in the uppermost stage of the fractionation apparatus became 66° C., and the gas phase temperature in the lowermost stage became 111° C. and stabilized.

The distillation was continued for 20 hours and no substantial change was observed.

The amount of liquid extracted per hour was 146 g/hour from the uppermost stage and 2554 g/hour from the lowermost stage.

Regarding the composition of the liquid collected in the 18th hour, the liquid extracted from the uppermost section was methanol 37%, water 2%, toluene 60%, and other 1%, and the liquid extracted from the bottom section was toluene 98%, methanol 0%, water 0%, oligomers of polyphenylene ether 1%, other 1%.

The liquid extracted from the lowermost stage was single-distilled to separate polyphenylene ether oligomers to obtain recovered toluene with a toluene content of 99% and a content of other amines that can be used as polymerization catalysts about 1%.

[Comparative example 1]

Using the same Oldershaw type fractionation apparatus as in Example 1, the good solvent phase to which no antifoaming agent was added was distilled. Perform the same operation as in Example 1, and after confirming that the gas phase temperature in the uppermost stage is stable to 110° C., a good solvent phase without an antifoaming agent is supplied from the position of the upper 20 stages of the fractionation device at an addition rate of 2700 g/hour.

Bubbles were observed in the uppermost stage, and the bubbles did not disappear even after 10 hours from the start of the supply.

Regarding the composition of the liquid extracted at the 10th hour after the start of the supply, the liquid extracted from the uppermost stage is 95% of toluene, 2.9% of methanol, 0.1% of water, 1% of polyphenylene ether oligomers, and 1% of others, and the liquid extracted from the lowermost stage The liquid is 96% of toluene, 2.3% of methanol, 0.1% of water, 1% of oligomers of polyphenylene ether, and 0.6% of others.

The liquid extracted from the lowermost stage was single-distilled, and neither methanol nor toluene from which water was removed was obtained.

[Comparative example 2]

Using the same Oldershaw type fractionation apparatus as in Example 1, the good solvent phase to which no antifoaming agent was added was distilled. Perform the same operation as in Example 1, and after confirming that the gas phase temperature in the uppermost stage is stable to 110° C., a good solvent phase without an antifoaming agent is supplied from the position of the upper 20 stages of the fractionation device at an addition rate of 450 g/hour.

10% of the liquid obtained by cooling the uppermost stage gas phase was extracted, and 90% was returned to the uppermost stage.

The lowermost gas phase is cooled and drawn off.

The amount of liquid extracted per hour was 25 g/hour from the uppermost stage and 425 g/hour from the lowermost stage.

The composition of the liquid collected from the lowest stage at the 18th hour was 98% toluene, 0% methanol, 0% water, 1% polyphenylene ether oligomer, and 1% others.

The liquid extracted from the lowermost stage was single-distilled to separate polyphenylene ether oligomers to obtain recovered toluene with a toluene content of 99% and a content of other amines that can be used as polymerization catalysts about 1%. However, compared with Example 1, only an extremely small amount of the good solvent phase can be processed in Comparative Example 2.

[Example 2]

As in Example 1, foaming was evaluated using the distillation evaluation apparatus shown in FIG. .

The above-mentioned good solvent phase 300ml that has added defoamer is packed in the 2L cylindrical glass container that has the nitrogen conduit that has spherical filter at the top and distillation pipe, cooling pipe, thermometer as shown in Figure 2, and this container is set in an oil bath set at 100 °C.

Nitrogen gas was blown in at 20 L/min through the nitrogen gas conduit.

Thirty minutes after the start of nitrogen blowing, the foaming height of the liquid was observed.

During this period, the maximum blister height was 8 mm.

[Example 3]

By the same method as in Example 2, the good solvent phase in which 30 mg of FA603 fluorosilicone-based antifoaming agent manufactured by Shin-Etsu Silicone Co., Ltd. was added to 60 kg of the good solvent phase was tested using the distillation evaluation device shown in FIG. 2 Blistering review.

Thirty minutes after the start of nitrogen blowing, the foaming height of the liquid was observed.

During this period, the maximum foaming height was 15 mm.

[Comparative example 3]

In the same manner as in Example 2, foaming was evaluated for the good solvent phase to which no antifoaming agent was added, using the distillation evaluation apparatus shown in FIG. 2 .

Thirty minutes after the start of nitrogen blowing, the foaming height of the liquid was observed.

During this period, the maximum foaming height was 64mm.

[Example 4]

Using the same method and apparatus as in Example 2, foaming was evaluated for a good solvent phase in which 150 mg of FQF501 fluorosilicone-based antifoaming agent manufactured by Toshiba Silicone Co., Ltd. was added to 60 kg of the good solvent phase.

Thirty minutes after the start of nitrogen blowing, the foaming height of the liquid was observed.

During this period, the maximum blister height was 7 mm.

[Example 5]

Using the same method and apparatus as in Example 2, foaming was evaluated for a good solvent phase in which 6 mg of FQF501 fluorosilicone-based antifoaming agent manufactured by Toshiba Silicone Co., Ltd. was added to 60 kg of the good solvent phase.

Thirty minutes after the start of nitrogen blowing, the foaming height of the liquid was observed.

During this period, the maximum foam height was 23 mm.

[Comparative example 4]

Using the same method and apparatus as in Example 2, foaming was evaluated for a good solvent phase in which 150 mg of KS69 silicone-based antifoaming agent manufactured by Shin-Etsu Silicone Co., Ltd. was added to 60 kg of the good solvent phase.

Thirty minutes after the start of nitrogen blowing, the foaming height of the liquid was observed.

During this period, the maximum foaming height was 140mm.

[Comparative Example 5]

Using the same method and apparatus as in Example 2, foaming was evaluated for a good solvent phase in which 150 mg of KS603 silicone-based antifoaming agent manufactured by Shin-Etsu Silicone Co., Ltd. was added to 60 kg of the good solvent phase.

Thirty minutes after the start of nitrogen blowing, the foaming height of the liquid was observed.

During this period, the maximum foaming height was 50mm.

[Comparative Example 6]

Using the same method and apparatus as in Example 2, foaming was evaluated for a good solvent phase in which 150 mg of an antifoaming agent formulated with Bronal C-448 mineral oil manufactured by Toho Chemical Co., Ltd. was added to 60 kg of a good solvent phase. .

Thirty minutes after the start of nitrogen blowing, the foaming height of the liquid was observed.

During this period, the maximum foaming height was 70mm.

Invention effect

The method for preparing polyphenylene ether of the present invention has very little foaming when distilling the good solvent of polyphenylene ether. Compared with the previous method, the recovery efficiency is greatly improved, and the purity of the recovered good solvent is also good, so the recovery efficiency is greatly improved. The equipment and energy required for solvent recovery fully meet the requirements of the industry.

Claims (3)

1. A method for preparing polyphenylene ether, in which an oxygen-containing gas is introduced into a polymerization solution composed of a good solvent of polyphenylene ether, a metal salt, an amine compound and a phenol compound to oxidatively polymerize the phenol compound, and then mixed in the polymerization solution A chelating agent aqueous solution is used to stop the polymerization, and a poor solvent of polyphenylene ether is added to the polyphenylene ether solution obtained by separating the metal salt, chelating agent, and water to precipitate polyphenylene ether particles and filter it. The method is characterized in that When the mixed solution obtained by filtering the polyphenylene ether particles is distilled to recover the good solvent, a fluorosilicone compound selected from the group consisting of fluoroalkyl or perfluoroalkyl substituted for part or all of the methyl groups of polydimethylsiloxane is used. , or more than one type of defoamer in the fluorosilicone compound-based defoamer composed of a mixture of a fluorosilicone compound and a silicone compound; Wherein, the good solvent is at least one solvent selected from benzene, toluene and xylene, the poor solvent is at least one solvent selected from methanol, ethanol, isopropanol, n-butanol, acetone and butanone, and the metal salt is selected At least one metal salt of a copper compound and a manganese compound, and the amine compound is at least one amine compound selected from a diamine compound, a monotertiary amine compound, and a monobasic secondary amine compound represented by the following general formula (1): Formula (1) In the formula, R1, R2, R3, and R4 each independently represent hydrogen, a straight-chain or branched alkyl group with a carbon number of 1 to 6, but not all of them are hydrogen at the same time; R5 represents a straight-chain or branched alkyl group with a carbon number of 2 to 5. Alkylene groups with methyl branches. 2. The method for preparing polyphenylene ether according to claim 1, characterized in that, after the polymerization is stopped by contacting with the chelating agent aqueous solution, the mixed solution is kept at 40°C to 120°C until the diphenoquinone produced during polymerization disappears , followed by separation of the catalyst. 3. The method for preparing polyphenylene ether according to claim 1 or 2, wherein water is mixed in the mixed solution obtained by filtering the precipitated polyphenylene ether particles, and separated into a good solvent phase composed of a good solvent and a poor solvent phase. After the aqueous phase which consists of a solvent and water is separated, a good solvent phase is distilled and a good solvent is recovered.

Images