JP2014080553A - Methyl phenol composition and method of producing polyphenylene ether - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a methyl phenol composition that gives a polyphenylene ether with an excellent color and has excellent solubility, and a method of producing a polyphenylene ether with high production efficiency by using the methyl phenol composition as a raw material.SOLUTION: In the methyl phenol composition, the water content is 10-700 ppm on weight basis. The methyl phenol composition comprises 2,6-dimethylphenol and/or 2,3,6-trimethylphenol.

Description

  The present invention relates to a methylphenol composition and a method for producing polyphenylene ether using the methylphenol composition.

  Modified polyphenylene ether resin using polyphenylene ether as a raw material can produce products and parts of a desired shape by molding methods such as melt injection molding and melt extrusion molding, so it can be used in the electrical / electronic field, automotive field, and other various industries. Widely used as a material for products and parts in the material field.

  Typical monomers for producing polyphenylene ether include 2,6-dimethylphenol and 2,3,6-trimethylphenol. Various studies have been made on impurities of these phenols.

  Patent Document 1 describes that 2,4,6-trimethylanisole in 2,6-xylenol (synonymous with 2,6-dimethylphenol) is less than 300 ppm and 2,6-dimethylcyclohexanone is less than 200 ppm. ing. According to Patent Document 1, the odor can be improved by using 2,6-xylenol as a raw material.

  Patent Document 2 describes a method of polymerizing polyphenylene ether using 2,6-dimethylphenol having an m-cresol content of 15 to 700 ppm. Patent Document 2 describes that the polymerization activity and color tone of polyphenylene ether can be improved by selecting this raw material.

JP 2010-132676 A WO2003 / 014050

  Since the main use of 2,6-dimethylphenol and / or 2,3,6-trimethylphenol is a raw material of polyphenylene ether, when this production / purification equipment and polyphenylene ether production equipment are not adjacent, 2,6-dimethylphenol and / or 2,3,6-trimethylphenol are extracted to a moving tank outside the system and transported to a polyphenylene ether production facility. However, even if it is 2,6-dimethylphenol and / or 2,3,6-trimethylphenol synthesized under the same conditions, polyphenylene ether with good color tone can be obtained by using the raw material before transportation. If the product after transportation is used, the color of polyphenylene ether may be poor. That is, even if the content of m-cresol is adjusted as in Patent Document 2, the color tone of polyphenylene ether is not necessarily improved.

  In addition, there is a problem in terms of production efficiency when using the transported monomer. From the viewpoint of transport efficiency, it is common to use a container with a large capacity for transporting the monomer. The larger the capacity, the more 2,6-dimethylphenol and / or 2,3,6-trimethylphenol after transport. It takes time to dissolve. If the dissolution takes time, the heating time becomes longer, so there is a concern not only about the cost problem but also the influence on the color tone.

  The present invention has been made in view of the above problems, and gives a polyphenylene ether having a good color tone and excellent solubility, and high production efficiency using the methylphenol composition as a raw material. It aims at providing the manufacturing method of polyphenylene ether.

  Production of polyphenylene ether because 2,6 dimethylphenol, 2,3,6-trimethylphenol, or a mixture of 2,6 dimethylphenol and 2,3,6-trimethylphenol becomes solid when not heated during transportation When used in the above, solvent dissolution or heat dissolution is required. As a result of intensive studies by the present inventors, when water is mixed at the time of dissolution, such as when water is mixed, 2,6-dimethylphenol and / or 2,3,6-trimethylphenol are present. It has been found that the color tone of polyphenylene ether produced using as a raw material deteriorates. On the other hand, it has also been found that if water is completely eliminated, it takes a very long time to dissolve the solid monomer.

  Based on the above knowledge, the present inventors set the water content in 2,6-dimethylphenol and / or 2,3,6-trimethylphenol to a specific range, It has been found that it is possible to dissolve a solid in a relatively short time without deteriorating the color tone of polyphenylene ether obtained by polymerizing 6-dimethylphenol and / or 2,3,6-trimethylphenol. It came to be completed.

That is, the present invention is as follows.
[1]
The water content is 10 to 700 ppm by weight,
Including 2,6-dimethylphenol and / or 2,3,6-trimethylphenol,
Methylphenol composition.
[2]
The methylphenol composition according to [1] above, wherein the water content is 15 to 500 ppm by weight.
[3]
A dissolving step for dissolving the methylphenol composition according to the above [1] or [2];
The manufacturing method of polyphenylene ether which has an oxidation polymerization process which oxidatively polymerizes the said methylphenol composition using a catalyst and oxygen-containing gas.
[4]
The method for producing polyphenylene ether according to [3] above, wherein the catalyst contains a copper compound, a halogen compound, and a diamine compound represented by the formula (1).
(Wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from the group consisting of a hydrogen atom and a linear or branched alkyl group having 1 to 6 carbon atoms. And all are not hydrogen at the same time. R ₅ represents a linear or branched alkylene group having 2 to 5 carbon atoms.)
[5]
The method for producing a polyphenylene ether according to [3] or [4] above, wherein the catalyst further contains at least one selected from the group consisting of a tertiary monoamine compound and a secondary monoamine compound.

  According to the present invention, a polyphenol ether having a good color tone is provided, and a methylphenol composition having excellent solubility is realized. Moreover, the manufacturing method of polyphenylene ether with the high production efficiency using the methylphenol composition is implement | achieved.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

[Methylphenol composition]
The methylphenol composition of this embodiment has a water content of 10 to 700 ppm by weight, 2,6-dimethylphenol, 2,3,6-trimethylphenol, or 2,6-dimethylphenol and 2, Contains 3,6-trimethylphenol. The methylphenol composition of this embodiment is useful as a monomer used in the production of polyphenylene ether. With the methylphenol composition of the present embodiment, the solid 2,6-dimethylphenol and / or 2,3,6-trimethylphenol are heated and dissolved at high speed, and the production efficiency of polyphenylene ether is high. Becomes higher. It is also possible to suppress the coloring of the monomer when the solid 2,6-dimethylphenol and / or 2,3,6-trimethylphenol is heated and dissolved, and the coloring of the polyphenylene ether after polymerization.

[Water content]
The water content in the methylphenol composition is 700 ppm or less, preferably 500 ppm or less, more preferably 400 ppm or less on a weight basis. When the upper limit is within the above range, the resulting polyphenylene ether tends to be more prevented from being colored. Moreover, even if it heats in order to dissolve a solid methylphenol composition by making water content 700 ppm or less, it exists in the tendency for the color tone of the obtained polyphenylene ether not to deteriorate. When the methylphenol composition did not contain water, even when heated and dissolved for a long time, the color tone of the monomer deteriorated, but the color tone of the polyphenylene ether was not observed. Therefore, it was specified that only the upper limit value exists in the water content to be adjusted in order to improve the color tone of the polyphenylene ether.

  On the other hand, by setting the lower limit of the water content, it is possible to obtain the effect of increasing the dissolution rate when heating and dissolving the solvent and improving the production efficiency. From the viewpoint of increasing the dissolution rate and improving the production efficiency of polyphenylene ether, the water content is 10 ppm or more, preferably 15 ppm or more, more preferably 20 ppm or more. Furthermore, by setting the water content to 10 ppm or more, the effect that the color tone of the monomer itself does not deteriorate even when heated for dissolution can be obtained.

  Generally, since the water content after the production of 2,6-dimethylphenol and / or 2,3,6-trimethylphenol is almost zero, the water content is adjusted to 10 to 700 ppm by a predetermined method. The adjustment method is not particularly limited. Specifically, a predetermined amount of water is extracted when 2,6-dimethylphenol and / or 2,3,6-trimethylphenol is extracted to a moving tank or the like outside the production equipment system. And a method of naturally absorbing the extracted 2,3-dimethylphenol and / or 2,3,6-trimethylphenol in the air. After reaching a predetermined water content, it is preferable to manage the water content so that it does not become excessive, such as purging the gas phase of the tank with an inert gas such as nitrogen.

  In addition to water contained in the methylphenol composition, o-cresol, o-ethylphenol, m-cresol, p-cresol, 2,4-dimethylphenol, 2,4,6-trimethylphenol, 2,4,6- Examples include trimethylanisole and 2,6-dimethylcyclohexanone. The methylphenol composition of the present embodiment is a methylphenol composition that gives polyphenylene ether having excellent solubility and good color tone by setting the water content to 10 to 700 ppm even if these impurities are contained. .

[Polyphenylene ether]
The polyphenylene ether produced by the method for producing polyphenylene ether of this embodiment will be described below. The produced polyphenylene ether is a homopolymer and / or copolymer having a repeating unit structure represented by the following formula (2).

In the formula (2), in the case of a 2,6-dimethylphenol unit, R ₆ and R ₈ are methyl groups, and R ₇ and R ₉ are hydrogen atoms. Similarly, in the case of 2,3,6-trimethylphenol units, R ₆ , R ₇ and R ₈ are methyl groups, and R ₉ is a hydrogen atom.

(Reduced viscosity)
The reduced viscosity of a chloroform solution prepared by dissolving 0.5 g of polyphenylene ether in chloroform to 1 g / dL, measured at 30 ° C. using a thermostatic viscosity thermostat (product name: VB-M6P, manufactured by Yoshida Chemical Instruments) is 0.15 to 1.0 dL / g, preferably 0.20 to 0.85 dL / g, and more preferably 0.25 to 0.70 dL / g. is there. When the reduced viscosity is 0.15 dL / g or more, more excellent mechanical properties tend to be exhibited. In addition, when the reduced viscosity is 1.0 dL / g or less, the solution viscosity at the time of polymerization does not become too high, the ability of peripheral equipment of the polymerization tank can be appropriately controlled, post-processing is easy, and workability is also good. It tends to be good.

(Number average molecular weight and molecular weight distribution)
Information related to the molecular weight of polyphenylene ether is obtained by measurement using a gel permeation chromatography (hereinafter also referred to as “GPC”) measuring device. Specifically, GPC was measured by Showa Denko Co., Ltd. Gel Permeation Chromatography System 21 (column: Showa Denko K-805L in series, column temperature: 40 ° C., solvent: chloroform, solvent flow rate: 1.0 mL / min, sample concentration: 1 g / L chloroform solution of polyphenylene ether), standard polystyrene (the molecular weight of standard polystyrene is 3,650,000, 2,170,000, 1,090,000, 681) , 2,000, 204,000, 52,000, 30,200, 13,800, 3,360, 1,300, 550). The UV wavelength of the detector can be selected from 254 nm for standard polystyrene and 283 nm for polyphenylene ether. As an index indicating the molecular weight distribution, a degree of dispersion represented by weight average molecular weight (Mw) / number average molecular weight (Mn) is used. The degree of dispersion indicates that the smaller the value is, the narrower the molecular weight distribution is, and 1 is the minimum value.

  The number average molecular weight (Mn) of the polyphenylene ether is preferably 7,000 or more and 35,000 or less. A more preferable lower limit is 8,000 or more, and a further preferable lower limit is 9,000 or more. Moreover, a more preferable upper limit is 30,000 or less, and a still more preferable upper limit is 25,000 or less. When the lower limit of the number average molecular weight is 7,000 or more, the mechanical properties tend to be more excellent. Further, when the upper limit of the number average molecular weight is 35,000 or less, the liquid viscosity during the polymerization reaction tends to be more favorable.

  The degree of dispersion of the polyphenylene ether is preferably 4.5 or less, more preferably 4.0 or less, still more preferably 3.75 or less, and even more preferably 3.5 or less. The degree of dispersion of the polyphenylene ether is preferably 1.6 or more, more preferably 1.8 or more, still more preferably 1.9 or more, and even more preferably 2.0 or more. When the degree of dispersion is in the above range, the balance between the low molecular weight component and the high molecular weight component is good, and polyphenylene ether having such a degree of dispersion tends to be more excellent in balance between chemical resistance and fluidity.

(Residual metal catalyst amount)
The polyphenylene ether preferably has a residual metal catalyst amount of less than 1.0 ppm, more preferably less than 0.8 ppm, even more preferably less than 0.6 ppm, and even more preferably less than 0.4 ppm. More preferably, it is more preferably less than 0.2 ppm. Here, the residual metal catalyst amount is an indicator of the purity of the polyphenylene ether itself. When the amount of the residual metal catalyst is less than 1.0 ppm, it becomes a high-purity polyphenylene ether and further tends to further suppress the yellowness after the heat history. The residual metal catalyst amount of polyphenylene ether can be measured with an atomic absorption spectrophotometer (manufactured by Shimadzu Corporation, product name AA-6650).

(Color tone)
The polyphenylene ether using the methylphenol composition of the present embodiment as a raw material has a good color tone. The color tone can be confirmed by the color index measurement method described in the examples.

[Production method of polyphenylene ether]
The method for producing the polyphenylene ether of this embodiment is as follows:
A dissolution step of dissolving the methylphenol composition;
An oxidation polymerization step of oxidizing the methylphenol composition using a catalyst and an oxygen-containing gas.

(Monomer)
The polyphenylene ether represented by the above formula (2) can be produced by polymerizing the above methylphenol composition. In particular, a methylphenol composition containing 2,6-dimethylphenol is preferably used because it is inexpensive and easily available. In addition to the above methylphenol composition, a divalent phenol compound represented by the following formula (3) may be further used.

  The divalent phenol compound represented by the formula (3) is a reaction between a corresponding monovalent phenol compound and a ketone or a dihalogenated aliphatic hydrocarbon, or a reaction between corresponding monovalent phenol compounds. Etc., and can be advantageously produced industrially. Although it does not specifically limit as a bivalent phenol compound, Specifically, the compound obtained by reaction with general purpose ketone compounds, such as formaldehyde, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, a cyclohexane, and a monovalent phenol compound Group and compound groups obtained by reaction of monovalent phenolic compounds.

Although it does not specifically limit as a bivalent phenol compound represented by Formula (3), Specifically, it represents with following formula (3-a), (3-b), and (3-c). Compounds.
(Wherein R ₁₀ , R ₁₁ , R ₁₂ , and R ₁₃ each independently represent hydrogen or a methyl group, and all are not hydrogen at the same time. X is a group directly connecting both aryl groups. , Methylene group, sulfur atom, ethylene group, isopropylidene group, and cyclohexylidene group.)

Representative compounds represented by formula (3) include compounds in which R ₁₀ and R ₁₁ are methyl groups, R ₁₂ and R ₁₃ are hydrogen, and X is directly connected to both aryl groups, R ₁₀ and R ₁₁ Is a methyl group, R ₁₂ and R ₁₃ are hydrogen and X is methylene, R ₁₀ and R ₁₁ are methyl groups, R ₁₂ and R ₁₃ are hydrogen and X is thio, R ₁₀ , R ₁₁ and R _A compound wherein ₁₂ is a methyl group, R ₁₃ is hydrogen and X is ethylene, R ₁₀ and R ₁₁ are methyl groups, R ₁₂ and R ₁₃ are hydrogen and X is isopropylidene, R ₁₀ and R ₁₁ are methyl groups A compound in which R ₁₂ and R ₁₃ are hydrogen and X is cyclohexylidene, a compound in which R ₁₀ , R ₁₁ and R ₁₂ are methyl groups, R ₁₃ is hydrogen and X is a direct connection of both aryl groups, R ₁₀ , _{R 11} Fine _{R 12} is a methyl _group, compounds X _{R 13} is hydrogen is _methylene, compound R _{10, R 11} and _{R 12} is a methyl _{group, R 13} is an X by hydrogen is _ethylene, R _{10, R 11} and R _A compound in which ₁₂ is a methyl group, R ₁₃ is hydrogen and X is thio, R ₁₀ , R ₁₁ and R ₁₂ are methyl groups, a compound in which R ₁₃ is hydrogen and X is isopropylidene, R ₁₀ , R ₁₁ , R ₁₂ And R ₁₃ is a methyl group and X is methylene, R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are methyl groups and X is ethylene, R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are methyl groups In which X is isopropylidene, but is not limited to these examples.

  In the oxidative polymerization step of polyphenylene ether, a polyhydric phenol compound can coexist in addition to the above-described phenol compound. Although it does not specifically limit as a polyhydric phenol compound, It has 3 or more and 9 or less phenolic hydroxyl group in a molecule | numerator, The alkyl group or alkylene group is located in the 2, 6-position of at least 1 phenolic hydroxyl group in the inside. The compound which has is mentioned. When the number of phenolic hydroxyl groups is within the above range, control of polymerization tends to be easier. The alkyl group or alkylene group at the 2-6 position is preferably a methyl group.

  Although it does not specifically limit as said polyhydric phenol compound, Specifically, 4,4 '-[(3-hydroxyphenyl) methylene] bis (2,6-dimethylphenol), 4,4'-[(3 -Hydroxyphenyl) methylene] bis (2,3,6-trimethylphenol), 4,4 '-[(4-hydroxyphenyl) methylene] bis (2,6-dimethylphenol), 4,4'-[(4 -Hydroxyphenyl) methylene] bis (2,3,6-trimethylphenol), 4,4 '-[(2-hydroxy-3-methoxyphenyl) methylene] bis (2,6-dimethylphenol), 4,4' -[(4-Hydroxy-3-ethoxyphenyl) methylene] bis (2,3,6-trimethylethylphenol), 4,4 '-[(3,4-dihydroxyphenyl) Tylene] bis (2,6-dimethylphenol), 4,4 ′-[(3,4-dihydroxyphenyl) methylene] bis (2,3,6-trimethylphenol), 2,2 ′-[(4-hydroxy Phenyl) methylene] bis (3,5,6-trimethylphenol), 4,4 ′-[4- (4-hydroxyphenyl) cyclohexylidene] bis (2,6-dimethylphenol), 4,4 ′-[ (2-Hydroxyphenyl) methylene] -bis (2,3,6-trimethylphenol), 4,4 ′-[1- [4- [1- (4-hydroxy-3,5-dimethylphenyl) -1- Methylethyl] phenyl] ethylidene] bis (2,6-dimethylphenol), 4,4 ′-[1- [4- [1- (4-hydroxy-3-fluorophenyl) -1-methylethyl] pheny ] Ethylidene] bis (2,6-dimethylphenol), 2,6-bis [(4-hydroxy-3,5-dimethylphenyl) ethyl] -4-methylphenol, 2,6-bis [(4-hydroxy-) 2,3,6-trimethylphenyl) methyl] -4-methylphenol, 2,6-bis [(4-hydroxy-3,5,6-trimethylphenyl) methyl] -4-ethylphenol, 2,4-bis [(4-Hydroxy-3-methylphenyl) methyl] -6-methylphenol, 2,6-bis [(4-hydroxy-3-methylphenyl) methyl] -4-methylphenol, 2,4-bis [( 4-hydroxy-3-cyclohexylphenyl) methyl] -6-methylphenol, 2,4-bis [(4-hydroxy-3-methylphenyl) methyl] -6-cyclohexyl Xylphenol, 2,4-bis [(2-hydroxy-5-methylphenyl) methyl] -6-cyclohexylphenol, 2,4-bis [(4-hydroxy-2,3,6-trimethylphenyl) methyl]- 6-cyclohexylphenol, 3,6-bis [(4-hydroxy-3,5-dimethylphenyl) methyl] -1,2-benzenediol, 4,6-bis [(4-hydroxy-3,5-dimethylphenyl) ) Methyl] -1,3-benzenediol, 2,4,6-tris [(4-hydroxy-3,5-dimethylphenyl) methyl] -1,3-benzenediol, 2,4,6-tris [( 2-hydroxy-3,5-dimethylphenyl) methyl] -1,3-benzenediol, 2,2′-methylenebis [6-[(4 / 2-hydroxy-2,5 / 3, -Dimethylphenyl) methyl] -4-methylphenol], 2,2'-methylenebis [6-[(4-hydroxy-3,5-dimethylphenyl) methyl] -4-methylphenol], 2,2'-methylenebis [6-[(4 / 2-hydroxy-2,3,5 / 3,4,6-trimethylphenyl) methyl] -4-methylphenol], 2,2'-methylenebis [6-[(4-hydroxy- 2,3,5-trimethylphenyl) methyl] -4-methylphenol], 4,4′-methylenebis [2-[(2,4-dihydroxyphenyl) methyl] -6-methylphenol], 4,4′- Methylenebis [2-[(2,4-dihydroxyphenyl) methyl] -3,6-dimethylphenol], 4,4′-methylenebis [2-[(2,4-dihydroxy-3-me Ruphenyl) methyl] -3,6-dimethylphenol], 4,4′-methylenebis [2-[(2,3,4-trihydroxyphenyl) methyl] -3,6-dimethylphenol], 6,6′- Methylenebis [4-[(4-hydroxy-3,5-dimethylphenyl) methyl] -1,2,3-benzenetriol], 4,4′-cyclohexylidenebis [2-cyclohexyl-6-[(2- Hydroxy-5-methylphenyl) methyl] phenol], 4,4′-cyclohexylidenebis [2-cyclohexyl-6-[(4-hydroxy-3,5-dimethylphenyl) methyl] phenol], 4,4 ′ -Cyclohexylidenebis [2-cyclohexyl-6-[(4-hydroxy-2-methyl-5-cyclohexylphenyl) methyl] phenol], 4 , 4′-cyclohexylidenebis [2-cyclohexyl-6-[(2,3,4-trihydroxyphenyl) methyl] phenol], 4,4 ′, 4 ″, 4 ″ ′-(1,2-ethanediylidene ) Tetrakis (2,6-dimethylphenol), 4,4 ′, 4 ″, 4 ″ ′-(1,4-phenylenedimethylidene) tetrakis (2,6-dimethylphenol) and the like.

  Among these, preferred polyhydric phenol compounds are 4,4 ′-[(4-hydroxyphenyl) methylene] bis (2,6-dimethylphenol), 4,4 ′-[(3-hydroxyphenyl) methylene] bis ( 2,6-dimethylphenol), 4,4 ′-[(4-hydroxyphenyl) methylene] bis (2,3,6-trimethylphenol), 4,4 ′-[(3-hydroxyphenyl) methylene] bis ( 2,3,6-trimethylphenol), 4,4 ′, 4 ″, 4 ″ ′-(1,4-phenylenedimethylidene) tetrakis (2,6-dimethylphenol).

[Dissolution process]
In the dissolving step, the methylphenol composition is dissolved. The dissolution method is not particularly limited as long as it is generally performed before polymerization, and specifically, a method of dissolving in a good solvent of polyphenylene ether used in polymerization (dissolution method 1), a dimethylphenol composition A method of dissolving a solid by heating (dissolution method 2) may be mentioned. By using the methylphenol composition, the time for solvent dissolution and heat dissolution is shortened, and the production efficiency of polyphenylene ether is improved.

  In the dissolution method 1, a methylphenol composition and a solvent are mixed. The dissolution time can be further shortened by stirring with a predetermined stirrer. Stirring conditions are not particularly limited, and can be performed under arbitrary conditions. In dissolution method 2, the methylphenol composition is heated and melted with a heater or the like. The heating conditions are not particularly limited, and can be performed under arbitrary conditions. In addition, when using said dihydric phenol compound and / or a polyhydric phenol compound, it does not restrict | limit, Even if it melt | dissolves simultaneously with a methyl phenol composition, it melt | dissolves with the melt | dissolved bihydric phenol compound etc. And may be mixed.

[Oxidative polymerization step]
In the oxidative polymerization step, the dissolved methylphenol composition is oxidatively polymerized using a catalyst and an oxygen-containing gas. Hereinafter, precipitation polymerization and solution polymerization will be described.

(Precipitation polymerization)
In the polyphenylene ether production process, when precipitation polymerization is performed, the oxidative polymerization process is divided into the following stages of the initial polymerization, middle polymerization, and late polymerization. In each of the following stages, the time until precipitation and the time until the slurry stabilizes vary depending on the amount of good solvent, amount of poor solvent, monomer type, and monomer concentration.
Polymerization initial period: period from the start of introduction of the oxygen-containing gas to the start of observation of precipitation.
Middle period of polymerization: Period from the start of precipitation until the slurry is stabilized.
Late polymerization: Period until the slurry is stabilized and the polymerization is completed.

  The state of polymer precipitation in the initial stage of polymerization can be observed visually as appropriate. Specifically, a method of visually observing the polymer deposition state from a viewing window of a predetermined reactor, a method of extracting the polymerization solution from a sampling port into a transparent container such as glass, and visually observing the deposition state, and the like can be mentioned.

  As a guideline for starting visual observation of the state of the polymer, although it depends on the amount of the phenolic compound contained in the polymerization system and the amount of the good or poor solvent for the polyphenylene ether, the polymerization rate preferably reaches 80%. More preferably, after the polymerization rate reaches 70%, and more preferably after the polymerization rate reaches 50%, the observation of the polymer is started while paying attention to the precipitation of the polymer. Even after the precipitation in the polymerization solvent is observed, it is preferable that the polymerization be continued in the middle of the polymerization while maintaining the precipitation and completed in the late polymerization.

  After the polymerization is completed, a poor solvent or the like can be added and washed. A solid-liquid suspension containing polyphenylene ether, a polymerization solvent, and a washing solvent is subjected to solid-liquid separation, and the resulting wet polyphenylene ether can be obtained. It is also possible to perform solid-liquid separation by adding a poor solvent or the like to the obtained wet polyphenylene ether and further washing. The washing can be repeated. The polyphenylene ether can be isolated by drying the wet polyphenylene ether thus obtained.

(Solution polymerization)
When producing polyphenylene ether, a polymerization method obtained by dissolving polyphenylene ether in a good solvent used for polymerization during polymerization and at the end of polymerization is called solution polymerization. When polyphenylene ether is precipitated as the polymerization proceeds, the temperature in the reaction system is increased at the beginning of polymerization or during polymerization, the amount of good solvent relative to the total amount of monomers used is increased, and monomers are added during polymerization. By performing a treatment such as selecting a polymerization solvent that does not precipitate, polymerization in a solution state can be completed.

  After the polymerization is completed, the polyphenylene ether can be isolated by a method of adding a poor solvent to the polymerization solution, a method of directly drying the polymerization solution, or the like. When a poor solvent is added to the polymerization solution that has been completely polymerized, polyphenylene ether is precipitated by the addition of the poor solvent. It is also possible to wash by adding a poor solvent or the like to the precipitated polyphenylene ether. The wet polyphenylene ether can be obtained by solid-liquid separation of the solid-liquid suspension containing the precipitated polyphenylene ether, the polymerization solvent, and the washing solvent. It is also possible to perform solid-liquid separation by adding a poor solvent or the like to the obtained wet polyphenylene ether and further washing. The washing can be repeated. The polyphenylene ether can be isolated by drying the wet polyphenylene ether thus obtained.

  In the oxidative polymerization step of polyphenylene ether, both the precipitation polymerization and the solution polymerization described above are performed while supplying an oxygen-containing gas. As an oxygen-containing gas, pure oxygen, oxygen and an inert gas such as nitrogen mixed at an arbitrary ratio, air, and further an inert gas such as air and nitrogen or a rare gas at an arbitrary ratio A mixture or the like can be used.

  The internal pressure during the polymerization reaction may be normal pressure, but may be reduced or increased as necessary. The supply rate of the oxygen-containing gas can be arbitrarily selected in consideration of heat removal, polymerization rate, etc., but is preferably 5 NmL / min or more, and more preferably 10 NmL / min or more, as pure oxygen per mole of phenol compound used for polymerization. .

(Good solvent used in the oxidation polymerization process)
The good solvent for the polyphenylene ether used in the oxidation polymerization step is not particularly limited, but specifically, at least one selected from the group consisting of benzene, toluene, and xylene is preferable.

(Poor solvent)
The poor solvent that can be added to the polymerization solution of polyphenylene ether is a solvent that does not dissolve polyphenylene ether at all or slightly dissolves it. Although it does not specifically limit as a specific example of a poor solvent, Specifically, ketones, alcohol, and water can be mentioned. Preferably, it is a C1-C10 alcohol. Examples of such poor solvents include methanol, ethanol, propanol, isopropanol, n-butanol, 2-butanol,
Examples include pentanol, hexanol, ethylene glycol, acetone, methyl ethyl ketone, and water. Among these, more preferable poor solvents are methanol, ethanol, isopropanol, n-butanol, 2-butanol, acetone, methyl ethyl ketone, and water. These poor solvents may be used alone or in combination of two or more.

  As an example of the polymerization method of polyphenylene ether, there is a method of oxidative polymerization of 2,6-dimethylphenol using a complex of cuprous salt and amine described in US Pat. No. 3,306,874 as a catalyst. The methods described in U.S. Pat. Nos. 3,306,875, 3,257,357 and 3,257,358, JP-B-52-17880, JP-A-50-51197, and JP-A-63-152628 are also polyphenylene. This is preferred as a method for producing ether.

  From the viewpoint of efficiently producing polyphenylene ether and from the viewpoint of producing polyphenylene ether having a specific molecular weight distribution, the monomer concentration is preferably 10 to 30% by mass, more preferably 13 to 27% by mass based on the total amount of the polymerization solution. preferable. When the monomer concentration is 10% by mass or more, the production efficiency of polyphenylene ether increases.

  When the monomer concentration is 30% by mass or less, it tends to be easily adjusted to a specific molecular weight. The present inventors presume this cause as follows. If the monomer concentration is 30% by mass or less, the liquid viscosity at the end of polymerization is relatively low, and uniform stirring becomes easy. For this reason, heterogeneous reaction is suppressed, and it is likely that polyphenylene ether having an unexpected molecular weight is obtained. As a result, as described above, it becomes easy to efficiently produce polyphenylene ether having a number average molecular weight of 7,000 to 35,000.

  To the polyphenylene ether polymerization reaction system, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal alkoxides, neutral salts such as magnesium sulfate and calcium chloride, zeolite, and the like may be added.

  Further, a surfactant that has been conventionally known to have an effect of improving the polymerization activity may be added to the polymerization solvent. As such a surfactant, for example, trioctylmethylammonium chloride known as Aliquat 336 and CapRiquat (trade name, manufactured by Dojindo Laboratories Co., Ltd.) can be mentioned. The amount used is preferably within a range not exceeding 0.1 mass% with respect to the total amount of the polymerization reaction raw material.

(catalyst)
A known catalyst system generally used for the production of polyphenylene ether may be added to the polymerization reaction system of polyphenylene ether. Examples of the catalyst include those composed of a transition metal ion having redox ability and an amine compound capable of complexing with the metal ion. Specific examples include a catalyst system composed of a copper compound and an amine, a catalyst system composed of a manganese compound and an amine, a catalyst system composed of a cobalt compound and an amine, and the like. Since the polymerization reaction of polyphenylene ether proceeds efficiently under some alkaline conditions, some alkali or further amine may be added thereto.

Although it does not specifically limit as said catalyst in the oxidation polymerization process of polyphenylene ether, Specifically, the catalyst containing a copper compound, a halogen compound, and the diamine compound represented by following formula (1) is mentioned. By using such a catalyst, there is a tendency that the polymerization rate can be further increased and the polymerization time can be further shortened. In addition, the molecular weight after polymerization tends to be more easily adjusted by adjusting the catalyst amount, oxygen blowing amount, polymerization time and the like.
(Wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from the group consisting of a hydrogen atom and a linear or branched alkyl group having 1 to 6 carbon atoms. And all are not hydrogen at the same time. R ₅ represents a linear or branched alkylene group having 2 to ₅ carbon atoms.)

  Although it does not specifically limit as a diamine compound shown by Formula (1), Specifically, N, N, N ', N'-tetramethylethylenediamine, N, N, N'-trimethylethylenediamine, N, N' -Dimethylethylenediamine, N, 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, Nn-propylethylenediamine, N, N'-di-n-propyl Ethylenediamine, Ni-propylethylenediamine, , N′-di-i-propylethylenediamine, Nn-butylethylenediamine, N, N′-di-n-butylethylenediamine, Ni-butylethylenediamine, N, N′-di-i-butylethylenediamine, N -T-butylethylenediamine, N, N'-di-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'- tetramethyluronium-1,5-diaminopentane, and the like.

Among these, in formula (1), a diamine compound having 2 or 3 carbon atoms in the alkylene group (R ₅ ) connecting two nitrogen atoms is preferable. Although the usage-amount of these diamine compounds is not specifically limited, It should be used in the range of 0.01 mol to 10 mol with respect to 100 mol of 2,6-dimethylphenol and / or 2,3,6-trimethylphenol used. Can do.

  As said copper compound which comprises a catalyst component, a cuprous compound, a cupric compound, or a mixture thereof can be used. Examples of the cuprous compound include cuprous chloride, cuprous bromide, cuprous sulfate, cuprous nitrate, and the like. Examples of the cupric compound include cupric chloride, cupric bromide, cupric sulfate, cupric nitrate, and the like. Among these, particularly preferred copper compounds are cuprous chloride, cupric chloride, cuprous bromide, and cupric bromide.

  These copper compounds may be synthesized from a halogen or an acid corresponding to an oxide (for example, cuprous oxide), carbonate, hydroxide or the like. For example, it can be synthesized by mixing cuprous oxide and a halogen compound (for example, a solution of hydrogen halide). These copper compounds may be used alone or in combination of two or more.

  The halogen compound constituting the catalyst component is not particularly limited, and specifically, hydrogen chloride, hydrogen bromide, hydrogen iodide, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, Examples include potassium iodide, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, and the like. These can be used as an aqueous solution or a solution using an appropriate solvent. Among these, preferred halogen compounds are an aqueous solution of hydrogen chloride and an aqueous solution of hydrogen bromide. These halogen compounds may be used alone or in combination of two or more.

  Although the usage-amount of the copper compound and halogen compound of a catalyst component is not specifically limited, When using both a copper compound and a halogen compound as a catalyst component, a halogen atom is 2 times-20 times with respect to the number-of-moles of a copper atom. The amount of copper atom used is preferably in the range of 0.02 mol to 0.6 mol with respect to 100 mol of 2,6-dimethylphenol and / or 2,3,6-trimethylphenol used. Is preferred. By being in the above range, the polymerization operation is facilitated, and the polymer physical properties after polymerization tend to be improved.

  As a polymerization catalyst, you may further contain at least 1 type selected from the group which consists of a tertiary monoamine compound and a secondary monoamine compound, for example other than the compound mentioned above.

  Although it does not specifically limit as a tertiary monoamine compound, Specifically, the aliphatic tertiary amine containing an alicyclic tertiary amine, etc. are mentioned. Such a tertiary monoamine compound is not particularly limited, and specifically includes trimethylamine, triethylamine, tripropylamine, tributylamine, triisobutylamine, dimethylethylamine, dimethylpropylamine, allyldiethylamine, dimethyl-n-butylamine. , Diethylisopropylamine, N-methylcyclohexylamine and the like. These tertiary monoamine compounds may be used alone or in combination of two or more. The amount used is not particularly limited, but is preferably 15 mol or less with respect to 100 mol of 2,6-dimethylphenol and / or 2,3,6-trimethylphenol used.

  It is not necessary to add all of the tertiary monoamine compounds normally used in the reaction system from the beginning. That is, some of them may be added in the middle, or some of them may be added sequentially from the start of polymerization. Further, it may be added to the monomer (2,6-dimethylphenol and / or 2,3,6-trimethylphenol) or the monomer solution at the same time as the polymerization is started, and may be added together therewith.

  Although it does not specifically limit as a secondary monoamine compound, Specifically, a secondary aliphatic amine is mentioned. Although it does not specifically limit as a secondary aliphatic amine, Specifically, a dimethylamine, diethylamine, di-n-propylamine, di-i-propylamine, di-n-butylamine, di-i-butylamine, Examples thereof include di-t-butylamine, dipentylamines, dihexylamines, dioctylamines, didecylamines, dibenzylamines, methylethylamine, methylpropylamine, methylbutylamine, and cyclohexylamine.

  Further, as the secondary monoamine compound, a secondary monoamine compound containing an aromatic can also be applied. Although it does not specifically limit as a secondary monoamine compound containing an aromatic, Specifically, N-phenylmethanolamine, N-phenylethanolamine, N-phenylpropanolamine, N- (m-methylphenyl) ethanolamine, N- (p-methylphenyl) ethanolamine, N- (2 ′, 6′-dimethylphenyl) ethanolamine, N- (p-chlorophenyl) ethanolamine, N-ethylaniline, N-butylaniline, N-methyl- Examples include 2-methylaniline, N-methyl-2,6-dimethylaniline, diphenylamine and the like. The above-mentioned secondary monoamine compounds may be used alone or in combination of two or more. Although the usage-amount of a secondary monoamine compound is not specifically limited, 15 mol or less is suitable with respect to 2,6-dimethylphenol and / or 2,3,6-trimethylphenol used.

  The post-treatment method after completion of the polymerization reaction is not particularly limited. Usually, an acid such as hydrochloric acid or acetic acid, ethylenediaminetetraacetic acid (EDTA) and a salt thereof, nitrilotriacetic acid and a salt thereof are used as a reaction solution. In addition, there is a method of deactivating the catalyst. The catalyst deactivator has a low polyphenylene ether solubility and is preferably added after being dissolved in, for example, water that is phase-separated from the polyphenylene ether good solvent. In this case, the deactivated catalyst is contained in a phase such as water and can be separated. By adding a solvent such as water to the solvent phase containing the separated polyphenylene ether and stirring again, the solvent phase can be washed and further phase-separated to remove water and the like. Further, it is possible to repeat the washing operation by adding water or the like.

  In the case of solution polymerization, before precipitating polyphenylene ether, it is possible to heat to a boiling point of the good solvent or higher, distill the good solvent, and concentrate the good solvent solution of polyphenylene ether. In the case of solution polymerization, there is a method of depositing polyphenylene ether by adding a poor solvent or the like to a good solvent solution of polyphenylene ether after post-treatment after the polymerization reaction of polyphenylene ether, or further concentrating as necessary. Can be mentioned.

  You may perform the washing | cleaning process of adding a poor solvent to the slurry liquid obtained in the said precipitation process, stirring, and wash | cleaning a good solvent. Then, it isolate | separates into a solvent and wet polyphenylene ether by a solid-liquid separation process. In that case, you may repeat the process of washing | cleaning wet polyphenylene ether with a poor solvent, and carrying out solid-liquid separation.

  The apparatus for solid-liquid separation after the washing process is not particularly limited, but a centrifuge (vibration type, screw type, decanter type, basket type, etc.) or vacuum filter (drum type filter, belt filter, rotary) Vacuum filter, Young filter, Nutsche, etc.), filter press, and roll press can be used.

  The wet polyphenylene ether obtained after the solid-liquid separation can be pulverized by a pulverizer to adjust the fine powder rate. Although it does not necessarily restrict | limit as a grinder, It is possible to use a jaw crusher, a cone crusher, a hammer mill, a feather mill, a ball mill, a high-speed rotation mill, a jet mill and the like.

  You may perform a drying process, after performing a precipitation process, a washing | cleaning process, and a grinding | pulverization as needed. The drying treatment is preferably performed at a temperature of at least 60 ° C., more preferably 80 ° C. or more, further preferably 120 ° C. or more, still more preferably 140 ° C. or more, and even more preferably 150 ° C. or more. When the polyphenylene ether is dried at a temperature of 60 ° C. or higher, the content of aromatic hydrocarbons in the polyphenylene ether can be efficiently suppressed.

  The amount of residual solvent is 1.5 from the viewpoint of the working environment in post-processing and from the viewpoint that the residual volatile gas at the time of extrusion can be prevented from backflowing and the operation can be kept stable. The content is preferably less than mass%, more preferably 0.3 mass% or less.

  In order to obtain polyphenylene ether powder with high efficiency, a method of increasing the drying temperature, a method of increasing the degree of vacuum in the drying atmosphere, a method of stirring during drying, and the like are effective. The method of raising is preferable from the viewpoint of production efficiency.

  In the drying step, it is preferable to use a dryer having a mixing function. Examples of the mixing function include a stirring type and a rolling type dryer. As a result, the processing amount can be increased and the productivity can be maintained high.

Hereinafter, the present invention will be specifically described with reference to specific examples and comparative examples. However, the present invention is not limited to the following examples.
First, measurement methods such as physical properties and characteristics applied to Examples and Comparative Examples are shown below.

(1) Measurement of water content The water content of the methylphenol composition was measured with a Karl Fischer moisture meter based on JIS K 0113.

(2) Measurement of color index The polyphenylene ether obtained in Examples and Comparative Examples was dissolved in chloroform to prepare a chloroform solution having a polyphenylene ether concentration of 0.05 g / mL. A quartz cell having a cell length of 1 cm was charged with the same chloroform as that used for dissolving the polyphenylene ether, and the absorbance of pure chloroform was measured with ultraviolet rays (wavelength 480 nm) to obtain an absorbance of 0. The chloroform solution of the polyphenylene ether prepared above was put in the same cell, and the absorbance at 480 nm was measured. The value obtained by subtracting the absorbance of pure chloroform from the absorbance of polyphenylene ether in chloroform and dividing by the polyphenylene ether concentration in the chloroform solution of polyphenylene ether was used as the color index value of polyphenylene ether.

[Comparative Example 1]
2,6-dimethylphenol was extracted from a product tank of 2,6-dimethylphenol (manufactured by Asahi Kasei Plastics Singapore Co., Ltd., product name: 2,6-xylenol) into an 18 L can (JIS Z162-1995). Water was not added to the extracted 2,6-dimethylphenol, and it was cooled to room temperature in a state where dry nitrogen gas was allowed to flow in an 18 L can to obtain a solid of the methylphenol composition of Comparative Example 1. It was 8 ppm when the water content after extraction was measured.

[Comparative Example 2]
An 18L can of 2,3,6-trimethylphenol (product name 2,3,6-trimethylphenol, manufactured by Honshu Chemical Industry Co., Ltd.) is inserted into an 18L can heater, and dry nitrogen is purged into the gas phase portion. Was set to 100 ° C. The water content after dissolution was 7 ppm. The 2,3,6-trimethylphenol solution having a water content of 7 ppm was cooled to room temperature while purging dry nitrogen in the gas phase portion, and the methylphenol composition of Comparative Example 2 was obtained.

[Example 1]
2,6-dimethylphenol was extracted from a product tank of 2,6-dimethylphenol (manufactured by Asahi Kasei Plastics Singapore Co., Ltd., product name: 2,6-xylenol) into an 18-liter L can (JIS Z162-1995). Water was added to the extracted 2,6-dimethylphenol, and the water content was adjusted to 17 ppm. After moisture adjustment, in a state where dry nitrogen gas was allowed to flow in an 18 L can, the product was cooled to room temperature to obtain a methylphenol composition solid of Example 1.

[Example 2]
Except having adjusted so that water content might be set to 25 ppm, operation similar to Example 1 was performed and the solid of the methylphenol composition of Example 2 was obtained.
Example 3
Except having adjusted so that water content might be set to 195 ppm, operation similar to Example 1 was performed and the solid of the methylphenol composition of Example 3 was obtained.

Example 4
Except having adjusted so that water content might be 255 ppm, operation similar to Example 1 was performed and the solid of the methylphenol composition of Example 4 was obtained.

Example 5
Except having adjusted so that water content might be 348 ppm, operation similar to Example 1 was performed and the solid of the methylphenol composition of Example 5 was obtained.

Example 6
Except having adjusted so that water content might be 442 ppm, operation similar to Example 1 was performed and the solid of the methylphenol composition of Example 6 was obtained.

Example 7
Except having adjusted so that water content might be set to 620 ppm, operation similar to Example 1 was performed and the solid of the methylphenol composition of Example 7 was obtained.

[Comparative Example 3]
The extracted 2,6-dimethylphenol was subjected to the same operation as in Comparative Example 1 except that it was cooled to room temperature while being open to the atmosphere without being added to the atmosphere, and solidified. A solid was obtained. The obtained methylphenol composition was heated to 100 ° C. and redissolved, and the water content was measured and found to be 772 ppm.

Example 8
An 18L can of 2,3,6-trimethylphenol (product name 2,3,6-trimethylphenol, manufactured by Honshu Chemical Industry Co., Ltd.) is inserted into an 18L can heater, and dry nitrogen is purged into the gas phase portion. Was set to 100 ° C. Water was added to the dissolved 2,3,6-trimethylphenol to adjust the water content to 17 ppm. 2,3,6-trimethylphenol having a water content of 17 ppm and 2,6-dimethylphenol adjusted to have a water content of 17 ppm in Example 1 were mixed in a dissolved state. The mixing ratio at this time was 2,6-dimethylphenol / 2,3,6-trimethylphenol = 75/25 (wt / wt). While purging dry nitrogen in the gas phase of the mixture, the mixture was cooled to room temperature to obtain a solid of the methylphenol composition of Example 8.

Example 9
The water content of 2,3,6-trimethylphenol was adjusted to 25 ppm, and the same operation as in Example 8 was performed except that 2,6-dimethylphenol of Example 2 was mixed. A solid of methylphenol composition was obtained.

Example 10
The water content of 2,3,6-trimethylphenol was adjusted to 195 ppm, and the same operation as in Example 8 was performed except that 2,6-dimethylphenol of Example 3 was mixed. A solid of methylphenol composition was obtained.

Example 11
The water content of 2,3,6-trimethylphenol was adjusted to 255 ppm, and the same operation as in Example 8 was performed except that 2,6-dimethylphenol of Example 4 was mixed. A solid of methylphenol composition was obtained.

Example 12
The water content of 2,3,6-trimethylphenol was adjusted to 348 ppm, and the same operation as in Example 8 was performed except that 2,6-dimethylphenol of Example 5 was mixed. A solid of methylphenol composition was obtained.

Example 13
The water content of 2,3,6-trimethylphenol was adjusted to 442 ppm, and the same operation as in Example 8 was performed except that 2,6-dimethylphenol of Example 6 was mixed. A solid of methylphenol composition was obtained.

Example 14
The water content of 2,3,6-trimethylphenol was adjusted to 620 ppm, and the same operation as in Example 8 was performed except that 2,6-dimethylphenol of Example 7 was mixed. A solid of methylphenol composition was obtained.

[Comparative Example 4]
A 2,6-dimethylphenol-dissolved product having a water content of 8 ppm in Comparative Example 1 and a 2,3,6-trimethylphenol-dissolved product having a water content of 7 ppm in Comparative Example 2 were combined with 2,6-dimethyl. The mixture was mixed so that the weight ratio of phenol / 2,3,6-trimethylphenol was 75/25 (wt / wt). The mixture was allowed to cool to room temperature while being open to the atmosphere and solidified to obtain a solid of the methylphenol composition of Comparative Example 4. The obtained methylphenol composition was heated to 100 ° C. and redissolved, and the water content was measured and found to be 778 ppm.

[Dissolution of methylphenol composition]
When a solid methylphenol composition is used for polymerization, it must be dissolved again. As a dissolution method, as described in detail below, a method of dissolving a solid methylphenol composition in a good solvent of polyphenylene ether used in polymerization (dissolution method 1), a method of dissolving a solid methylphenol composition by heating (Dissolution method 2). In this example, the dissolution time until complete dissolution was measured by these two methods.

(Dissolution method 1)
A cube having a side of about 10 mm was cut out from the lump of the methylphenol composition and weighed about 1000 g. The same amount of toluene as the weighed methylphenol composition was added thereto, and the mixture was stirred at room temperature (25 ° C.). The stirring blades used were six turbine blades having a diameter of 60 mm and a blade height of 8 mm, and were melted at a rotational speed of 600 rpm. The dissolution time until the solid of the methylphenol composition disappeared visually was measured.

(Dissolution method 2)
The 18 L can containing the methylphenol composition was inserted into an 18 L can heater, and the temperature was set to 100 ° C. The dissolution time until the lump of the methylphenol composition in the 18 L can no longer be seen was measured. The measured dissolution time is the time after the heater switch is turned on, and includes the temperature raising time.

[Production example]
A flow rate of 0.5 L / min is provided in a 40 L jacketed polymerization tank equipped with a sparger for introducing an oxygen-containing gas, a stirring turbine blade and a baffle at the bottom of the polymerization tank, and equipped with a reflux condenser in the vent gas line at the top of the polymerization tank. 4.57 g of cupric oxide, 24.18 g of 47% by mass hydrogen bromide aqueous solution, 11.00 g of di-t-butylethylenediamine, 62.72 g of di-n-butylamine, 149 .92 g of butyldimethylamine, 20.65 kg of toluene, and 3.12 kg of dissolved methylphenol composition (2,6-dimethylphenol) are added to form a homogeneous solution, and the internal temperature of the polymerization tank reaches 25 ° C. Until stirred.

  Next, dry air was introduced into the polymerization tank at a rate of 32.8 NL / min from a sparger and polymerization was started. Dry air was bubbled through for 185 minutes to obtain a polymerization mixture. During the polymerization, the internal temperature was controlled to 40 ° C. The polymerization solution at the end of the polymerization was in a uniform solution state.

  The ventilation of dry air was stopped, and 10 kg of a 2.5 mass% aqueous solution of ethylenediaminetetraacetic acid tetrasodium salt (a reagent manufactured by Dojindo Laboratories) was added to the polymerization mixture. The polymerization mixture was stirred at 70 ° C. for 150 minutes, then allowed to stand for 20 minutes, and the organic and aqueous phases were separated by liquid-liquid separation. The separated organic phase was obtained as a toluene solution containing 13.1% by mass of polyphenylene ether (hereinafter referred to as “polymer solution”).

  The obtained polymer solution was put into a stirring tank equipped with a jacket, and heated by flowing a heating medium at 120 ° C. through the jacket. Steam generated from toluene as a main component was cooled by a condenser, and the toluene was extracted out of the system, and concentrated until the polymer concentration in the stirring tank reached 30.5% by mass.

  Next, the polymer was deposited using a jacketed deposition tank equipped with the draft tube shown in Example 1 of International Publication No. 2003/064499 and four inclined paddle blades. In addition, it was set as the precipitation tank which added and provided four baffles outside the draft tube. The amount of liquid in the precipitation tank during this precipitation tank operation was 1100 mL. The precipitation tank was charged with 500 g of toluene and 500 g of methanol, and stirred at 1500 rpm. The precipitation tank was provided with an overflow line, and when the amount of the internal liquid exceeded 1100 mL, the internal liquid overflowed and was discharged outside the tank. The position of the feed line was the same as the position described in Example 1 of International Publication No. 2003/064499. 230 g / min of methanol containing 3.0% by mass of water and 542 g / min of the above 30.5% by mass polymer solution were fed into the precipitation tank. The paddle blade continued to rotate at 1500 rpm. The slurry liquid obtained by precipitating polyphenylene ether was discharged from the precipitation tank at 772 g / min and fed to the washing tank by a slurry pump.

  To the washing tank, methanol was fed from another line at 350 g / min, and stirred with the slurry liquid to replace and wash toluene in the polyphenylene ether particles, thereby producing a washing slurry liquid having a slurry concentration of 15% by mass.

  The slurry was filtered through a basket centle (0-15 type, manufactured by Tanabe Wiltech). After each filtration, methanol equivalent to the polymer was sprayed onto the wet polyphenylene ether in the basket centre and then filtered again to obtain wet polyphenylene ether.

  Subsequently, the wet polyphenylene ether was held at 150 ° C. and 1 mmHg for 1.5 hours to obtain a dried polyphenylene ether powder. The obtained polyphenylene ether powder was measured for color index by the method described above.

[Comparative Example 5]
The dissolution time by dissolution method 1 and dissolution method 2 was measured using the methylphenol composition of Comparative Example 1 as a raw material. Moreover, the polyphenylene ether powder of the comparative example 5 was produced by the method shown in the said manufacture example using the methylphenol composition of the comparative example 1 melt | dissolved by the melt | dissolution method 2. The results of measuring the color index of this polyphenylene ether by the above method are shown in Table 1.

[Comparative Example 6]
The dissolution time by dissolution method 1 and dissolution method 2 was measured using the methylphenol composition of Comparative Example 2 as a raw material. Moreover, the polyphenylene ether powder of the comparative example 6 was produced by the method shown in the said manufacture example using the methylphenol composition of the comparative example 2 melt | dissolved by the melt | dissolution method 2. The color index of this polyphenylene ether was measured by the above method. The results are shown in Table 1.

[Examples 15 to 21]
Except having used the methylphenol composition used below, operation similar to the comparative example 5 was performed, and the polyphenylene ether of Examples 15-21 was obtained. The evaluation results are shown in Table 1.
Example 15: Use of the methylphenol composition of Example 1 Example 16: Use of the methylphenol composition of Example 2 Example 17: Use of the methylphenol composition of Example 3 Example 18: Methylphenol composition of Example 4 Example 19: Use of the methylphenol composition of Example 5 Example 20: Use of the methylphenol composition of Example 6 Example 21: Use of the methylphenol composition of Example 7

[Comparative Example 7]
A polyphenylene ether of Comparative Example 7 was obtained in the same manner as in Comparative Example 5 except that the methylphenol composition used was the methylphenol composition of Comparative Example 3. The evaluation results are shown in Table 1.

[Examples 22 to 28]
Except having used the methylphenol composition used below, operation similar to the comparative example 6 was performed, and the polyphenylene ether of Examples 22-28 was obtained. The evaluation results are shown in Table 1.
Example 22: Use of the methylphenol composition of Example 8 Example 23: Use of the methylphenol composition of Example 9 Example 24: Use of the methylphenol composition of Example 10 Example 25: Methylphenol composition of Example 11 Example 26: Use of the methylphenol composition of Example 12 Example 27: Use of the methylphenol composition of Example 13 Example 28: Use of the methylphenol composition of Example 14

[Comparative Example 8]
A polyphenylene ether of Comparative Example 8 was obtained in the same manner as in Comparative Example 6 except that the methylphenol composition used was the methylphenol composition of Comparative Example 4. The evaluation results are shown in Table 1.

* 2,6-DMP: 2,6-dimethylphenol 2,3,6-TMP: 2,3,6-trimethylphenol

* 2,6-DMP: 2,6-dimethylphenol 2,3,6-TMP: 2,3,6-trimethylphenol

  As shown in Table 1, when the water content in the methylphenol composition was lower than 10 wtppm (Comparative Example 1), the solvent solubility and the heat solubility were low. The time required for dissolution in the examples and comparative examples was evaluated with an 18 L can, but when transporting and dissolving industrially, a much larger amount of methylphenol composition should be handled. Therefore, it is natural that the time required for dissolution also increases with this, and the difference in dissolution time becomes more remarkable. Moreover, when there was much water content in a methylphenol composition (comparative example 2), there existed a tendency for the color tone (color index) of the polyphenylene ether after superposition | polymerization to deteriorate.

  By using a methylphenol composition having a specific water content, dissolution time can be reduced and production efficiency can be improved. Moreover, the color tone deterioration of the polyphenylene ether after superposition | polymerization can also be suppressed. The polyphenylene ether obtained from such a methylphenol composition has industrial applicability as a material for automobile parts, heat-resistant parts, electronic equipment parts, industrial parts and the like.

Claims (5)

The water content is 10 to 700 ppm by weight,
Including 2,6-dimethylphenol and / or 2,3,6-trimethylphenol,
Methylphenol composition.   The methylphenol composition according to claim 1, wherein the water content is 15 to 500 ppm by weight. A dissolution step of dissolving the methylphenol composition according to claim 1 or 2,
The manufacturing method of polyphenylene ether which has an oxidation polymerization process which oxidatively polymerizes the said methylphenol composition using a catalyst and oxygen-containing gas. The manufacturing method of the polyphenylene ether of Claim 3 in which the said catalyst contains the diamine compound represented by a copper compound, a halogen compound, and Formula (1).
(Wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from the group consisting of a hydrogen atom and a linear or branched alkyl group having 1 to 6 carbon atoms. And all are not hydrogen at the same time. R ₅ represents a linear or branched alkylene group having 2 to 5 carbon atoms.)   The method for producing a polyphenylene ether according to claim 3 or 4, wherein the catalyst further comprises at least one selected from the group consisting of a tertiary monoamine compound and a secondary monoamine compound.