JP5362410B2 - Polyphenylene ether - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyphenylene ether that exhibits good flowability and high mechanical properties, is suppressed in generation of foreign matter such as gel on melt processing, and is readily handleable. <P>SOLUTION: The polyphenylene ether includes less than 20 mass% of a polyphenylene ether ingredient having a molecular weight of at most 8,000 and less than 20 mass% of a polyphenylene ether ingredient having a molecular weight of at least 50,000 and has a weight-average molecular weight (Mw)/number-average molecular weight (Mn) value of at most 2.8, each molecular weight being measured by the gel permeation chromatography where standard polystyrenes are used for the calibration curve, and has a residual metal catalyst amount of at most 2.0 ppm. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to polyphenylene ether.

Polyphenylene ether is excellent in processability and productivity, and has an advantage that a product or part having a desired shape can be efficiently produced by a molding method such as melt injection molding or melt extrusion molding. Taking advantage of these advantages, it is widely used in the fields of electrical and electronic materials, automobiles, other various industrial materials, food packaging, and parts.
In recent years, as a new industrial application of polyphenylene ether, the use as a composite material for obtaining excellent characteristics in combination with other resins and the use as an electronic material have been studied. Polyphenylene ether having a low molecular weight is considered to be more effective than conventionally known polyphenylene ether.
For this reason, development of an efficient production method of low-molecular weight polyphenylene ether having good performance, for example, a method capable of simplifying the line, has been demanded.

Conventionally, various proposals have been made on polyphenylene ether, for example, low molecular weight polyphenylene ether for the purpose of solvent solubility and modification (see, for example, Patent Documents 1 and 2), and gas barrier properties. For example, high molecular weight polyphenylene ether (see, for example, Patent Document 3).
Moreover, what improved the fluidity | liquidity etc. by mixing low molecular weight polyphenylene ether and high molecular weight polyphenylene ether is proposed (for example, refer patent documents 4 thru | or 6).

  Patent Document 6 discloses a polyphenylene ether having a reduced viscosity of 0.4 to 3.0 dl / g polymerized in a main polymerization line, and a reduced viscosity of 0.05 to 0.6 dl / g bypassed from the main polymerization line. There has been proposed a method for continuously producing polyphenylene ether having a bimodal molecular weight distribution by mixing polyphenylene ethers having a molecular weight. This method enables continuous production of low-viscosity polyphenylene ether, which was difficult with slurry polymerization.

In general, in order to obtain good processing fluidity, a wider molecular weight distribution is preferred, but in order to obtain excellent properties in terms of physical properties, a narrower molecular weight distribution is preferred. A narrow distribution of polyphenylene ether has been demanded.
In particular, when a low molecular weight polyphenylene ether having a narrow molecular weight distribution is mixed with a high molecular weight, the polymer characteristics tend to appear clearly.
For example, since there is a tendency to cause speed spots and density spots when dissolved in a solvent, polyphenylene ether having a low molecular weight and a narrow molecular weight distribution has been required from the viewpoint of avoiding such inconvenience. .

  On the other hand, foreign substances such as gels may be generated during melt processing, and therefore, development of techniques and additives for suppressing gels has been required.

As a method for producing a relatively low molecular weight polyphenylene ether, a technique has been proposed in which 2,4,6-trimethylphenol is added in the polyphenylene ether polymerization step, and the amount of polyphenylene ether is changed by controlling the amount added. (For example, refer to Patent Document 7).
Patent Document 7 uses a mixed solvent of a good solvent of polyphenylene ether (eg, benzene, toluene, xylene) and a poor solvent of polyphenylene ether (eg, ketone, ether, alcohol) as a solvent. It is described that polyphenylene ethers of various molecular weights are obtained by changing the ratio.

  Also, aromatic hydrocarbons (eg, benzene, toluene, xylene, etc.) that are good solvents for polyphenylene ether and aliphatic hydrocarbons (eg, n-hexane, isohexane, n-heptane, etc.) that are poor solvents for polyphenylene ether. A method for carrying out polymerization of polyphenylene ether in a mixed solvent is disclosed (for example, see Patent Document 8).

US Patent Application Publication No. 2003/0130438 JP 2004-99824 A International Publication No. 2002/12370 US Patent Application Publication No. 2003/23006 British Patent No. 0401690 Japanese Patent Application Laid-Open No. 11-012354 U.S. Pat. No. 3,440,217 Japanese Patent Publication No. 50-6520

However, the polyphenylene ether obtained by the method disclosed in Patent Document 6 has a wide molecular weight distribution, a narrow molecular weight distribution required in recent years, and is always satisfactory as a technique for obtaining a polyphenylene ether excellent in physical properties. is not.
The method disclosed in Patent Document 7 has a problem that it lacks accuracy as a method for obtaining a polymer having a required molecular weight.
In the method disclosed in Patent Document 8, generated water and amines are present in the reaction system, and when the reaction proceeds in such a state, oligophenylene ether particles are generated non-uniformly and adhere to the reactor or the like. It has the disadvantage of being easy to do.

  In general, polyphenylene ether is often obtained in the form of powder, and when it is injected into a feeder such as when it is melt kneaded, dust is often scattered due to powder scattering and high dust generation. Therefore, polyphenylene ether with suppressed scattering and dust generation properties has been demanded.

  Therefore, in view of the above-mentioned problems of the prior art, the present invention has good fluidity and high mechanical properties, suppresses the generation of foreign substances such as gel during melt processing, and also has good handling properties. An object of the present invention is to provide a polyphenylene ether.

As a result of diligent research on the above-described problems of the prior art, the present inventors have determined that the generation of foreign substances such as gels generated during melt processing, processing fluidity, and mechanical strength are less than a predetermined molecular weight. It was found that the component amount, the component amount equal to or higher than the predetermined molecular weight, the amount of residual metal catalyst, and the ratio (Mw / Mn) of the weight average molecular weight to the number average molecular weight are influencing.
Therefore, in the present invention, these influencing factors are examined in detail, the processing fluidity is good, the mechanical strength is high, the generation of foreign matters such as gels during melt processing can be suppressed, and the handling property is further improved. Also provides an excellent polyphenylene ether.
That is, the present invention is as follows.

[1] In a molecular weight measured by gel permeation chromatography using standard polystyrene as a calibration curve, a polyphenylene ether component having a molecular weight of 8000 or less is less than 20% by mass, and a polyphenylene ether component having a molecular weight of 50,000 or less is less than 20% by mass. A polyphenylene ether having a weight average molecular weight (Mw) / number average molecular weight (Mn) value of 2.8 or less and a residual metal catalyst amount of 2.0 ppm or less is provided.

[2] The content of Kaoru aromatic hydrocarbons to provide a polyphenylene ether according to the less than 1.5 wt% 0.01 wt% [1].

[3] The polyphenylene ether according to [1] or [2], wherein the polyphenylene ether component having a molecular weight of 10,000 to 40,000 is 60% by mass or more.

[4] 310 ° C. for 20 minutes, Oite after heating at a pressure of 10 MPa, molecular weight 8000 or less of the polyphenylene ether component is less than 20 wt%, a molecular weight of 50,000 or more polyphenylene ether component is less than 20 mass%, weight average The polyphenylene ether according to any one of [1] to [3], wherein the value of molecular weight (Mw) / number average molecular weight (Mn) is 2.8 or less.

[5] instead of the .eta.a the original viscosity, 20 minutes at 310 ° C., when the ItaB the reduced viscosity after heating at a pressure of 10 MPa, the relational expression 0.10 ≦ (ηB-ηA) /ηA≦0.30 The polyphenylene ether according to any one of [1] to [4], wherein the polyphenylene ether is satisfied.

[6] The polyphenylene ether according to any one of [1] to [5], which has a number average molecular weight of 9000 or more and 25000 or less.

According to the present invention, it is possible to provide a polyphenylene ether that has good processing fluidity, has high mechanical strength, and further effectively suppresses the generation of gel and is excellent in handleability as a powder. .
Since the polyphenylene ether of the present invention is excellent in processing fluidity, it is possible to stably supply raw materials during melt kneading with other resins.

  Hereinafter, although the form for implementing this invention (henceforth "this embodiment") is demonstrated, this invention is not limited to the form shown below.

[Polyphenylene ether]
The polyphenylene ether in this embodiment is a polyphenylene ether having a molecular weight measured by gel permeation chromatography (GPC) using standard polystyrene as a calibration curve and having a molecular weight of 8000 or less and a polyphenylene ether component of less than 20% by mass and 50,000 or more. It is a polyphenylene ether having a component of less than 20% by mass, a weight average molecular weight (Mw) / number average molecular weight (Mn) value of 2.8 or less, and a residual metal catalyst amount of 2.0 ppm or less.

As specific measurement conditions of gel permeation chromatography, 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, 681,000, 204,000, 52,000, 30,200, 13,800, 3,360, 1,300, 550) can be prepared and measured.
The UV wavelength of the detector can be selected from 254 nm for standard polystyrene and 283 nm for polyphenylene ether.

Polyphenylene that has a sufficiently high fluidity during melt processing and suppresses the generation of foreign substances such as gels during melt processing by prescribing a component amount with a molecular weight of 8000 or less and a component amount of 50,000 or more while maintaining high mechanical properties. Become ether.
From the viewpoint of the mechanical strength of polyphenylene ether, the component having a molecular weight of 9000 or less is preferably less than 20% by mass, the molecular weight of 10,000 or less is more preferably less than 20% by mass, and the molecular weight is 11,000. More preferably, the following is less than 20% by mass.
In addition, from the viewpoint of obtaining good molding fluidity and preventing the occurrence of glazing at the time of melt processing, the component having a molecular weight of 45,000 or more is preferably less than 20% by mass, and the component having 40,000 or more is 20% by mass. More preferably, the content of 35,000 or more is less than 20% by mass.

  Furthermore, when the value (Mw / Mn) of weight average molecular weight (Mw) / number average molecular weight (Mn) is 2.8 or less, the balance between fluidity and mechanical properties becomes good. Mw / Mn is preferably 2.6 or less, more preferably 2.5 or less, and even more preferably 2.4 or less.

Polyphenylene ethers can generally increase or decrease in molecular weight when heated.
In the polyphenylene ether of the present embodiment, the amount of a component having a molecular weight of 8000 or less measured by gel permeation chromatography using a standard polystyrene of polyphenylene ether as a calibration curve is less than 20% by mass and 50,000 or more. It is preferable that the amount of the component is less than 20% by mass, and the value of weight average molecular weight (Mw) / number average molecular weight (Mn) is 2.8 or less.
In addition, “polyphenylene ether after heating” includes polyphenylene ether after melt-kneading, polyphenylene ether after molding, polyphenylene ether after compression, and the like. As an example of a typical method, 20 minutes at 310 ° C. There are a method for measuring the molecular weight of a compressed polyphenylene ether at a pressure of 10 MPa by the gel permeation chromatography, a method for measuring only a polyphenylene ether portion extracted from a mixed resin composition melt-kneaded with another resin, and the like.

In the polyphenylene ether of the present embodiment, as one of many factors of foreign matters such as gels generated during melt processing, a component amount having a molecular weight of 8000 or less, a component amount having a molecular weight of 50,000 or more, and a residual metal catalyst amount are simultaneously present. It is mentioned to satisfy. That is, when the component having a molecular weight of 8000 or less is contained in an amount of 20% by mass or more, 50,000 or more is contained in an amount of 20% by mass or more, and the residual metal catalyst is contained in an amount of 2.0 ppm or more, the above disadvantages occur.
Therefore, in this embodiment, the residual metal catalyst is less than 2.0 ppm, the molecular weight is 8000 or less is less than 20% by mass, and the 50,000 or more is less than 20% by mass, and foreign matters such as generated gel are suppressed during melt processing. Polyphenylene ether was used.
The residual metal catalyst is preferably less than 1.8 ppm, more preferably less than 1.6 ppm, and even more preferably less than 1.5 ppm.

Furthermore, in the polyphenylene ether of the present embodiment, the residual amount of aromatic hydrocarbon used for production is preferably in the range of 0.01% by mass or more and less than 1.5% by mass with respect to the polyphenylene ether.
When the residual amount of the aromatic hydrocarbon is 1.5% by mass or more, coupled with the fact that the component amount having a molecular weight of 50,000 or more is 20% by mass or more and the component amount having a molecular weight of 8,000 or less is 20% by mass or more. There is a possibility that eyes and eyes may be generated during melt processing.
On the other hand, if it is less than 0.01% by mass, it is necessary to take a long drying time in the drying process in the production process of polyphenylene ether, which is unsuitable for mass production, and industrial feasibility is low. Become.
From the above viewpoint, in the polyphenylene ether of this embodiment, the residual amount of aromatic hydrocarbon used in the production is in the range of 0.01% by mass or more and less than 1.5% by mass, and 0.01% by mass The range of 1.2% by mass or more is preferable, the range of 0.01% by mass or more and 1.0% by mass or less is more preferable, and the range of 0.1% by mass or more and 1.0% by mass or less is more preferable.

In the polyphenylene ether of this embodiment, as one of many factors of foreign matters such as gels generated during melt processing, there is a component amount other than a component having a molecular weight of 10,000 to 40,000.
When the molecular weight component outside the above range is increased, there is a tendency for eyes and eyes to be generated. Therefore, when the component having a molecular weight of 10,000 to 40,000 is 60% by mass or more, the generation of foreign matter and eyes is effectively suppressed, and the processing flow is reduced. And the balance with mechanical properties becomes good.
The amount of the component having a molecular weight of 10,000 to 40,000 is preferably 63% by mass or more, the component having a molecular weight of 10,000 to 60,000 is more preferably 65% by mass or more, and more preferably 70% by mass or more. preferable.

In the polyphenylene ether of the present embodiment, the reduced viscosity ηA before heating and the reduced viscosity ηB after heating preferably satisfy the relational expression 0.10 ≦ (ηB−ηA) /ηA≦0.30.
The reduced viscosity means the reduced viscosity of a 0.5 g / dl concentration chloroform solution of polyphenylene ether resin at 30 ° C.
Further, the “reduced viscosity ηB after heating” means the reduced viscosity after hot pressing the polyphenyl ether resin before heating at 310 ° C. and 10 MPa for 20 minutes.
When the relational expression (ηB−ηA) / ηA> 0.3 is satisfied, the increase in molecular weight due to heating becomes remarkable, fluidity is deteriorated, and inconveniences such as generation of foreign matters such as gel may occur.
Further, if (ηB−ηA) / ηA <0.1, sufficient mechanical strength may not be obtained.
From the viewpoint of obtaining good working fluidity, practically sufficient mechanical strength, excellent balance between the two, and further suppressing the generation of foreign matter, preferably 0.10 ≦ (ηB−ηA) / ηA ≦ 0.25, more preferably 0.12 ≦ (ηB−ηA) /ηA≦0.22, and most preferably 0.12 ≦ (ηB−ηA) /ηA≦0.19.

In the polyphenylene ether of this embodiment, the number average molecular weight Mn measured by gel permeation chromatography using standard polystyrene as a calibration curve is 9000 or more and 25000 or less from the viewpoint of the balance between processing fluidity and mechanical strength. preferable.
The number average molecular weight Mn is more preferably 9000 or more and 22000 or less, further preferably 9000 or more and 18000 or less, and further preferably 9000 or more and 15000 or less.

[Structure of polyphenylene ether]
The polyphenylene ether of this embodiment has a structural unit (a) represented by the following formula (1), and may have a plurality of types of structural units (a).

In formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, or a substituted group. An alkynyl group which may be substituted, an aryl group which may be substituted, an aralkyl group which may be substituted, or an alkoxy group which may be substituted; R ₅ is a halogen atom or optionally substituted An alkyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, or an optionally substituted alkoxy group is shown.

In the formula (1), examples of the halogen atom represented by R ₁ , R ₂ , R ₃ and R ₄ include a fluorine atom, a chlorine atom and a bromine atom, and a chlorine atom and a bromine atom are preferable.

In the formula (1), the “alkyl group” of the optionally substituted alkyl group represented by R ₁ , R ₂ , R ₃ and R ₄ preferably has 1 to 6 carbon atoms, more preferably 1 To 3 or a linear or branched alkyl group, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl and the like. Methyl and ethyl are preferable, and methyl is more preferable.

In the formula (1), examples of the “alkenyl group” of the optionally substituted alkenyl group represented by R ₁ , R ₂ , R ₃ and R ₄ include ethenyl, 1-propenyl, 2-propenyl, Examples include 3-butenyl, pentenyl, hexenyl and the like, and ethenyl and 1-propenyl are preferable.

In the formula (1), examples of the “alkynyl group” of the optionally substituted alkynyl group represented by R ₁ , R ₂ , R ₃ , and R ₄ include ethynyl, 1-propynyl, 2-propynyl ( Propargyl), 3-butynyl, pentynyl, hexynyl and the like, and ethynyl, 1-propynyl and 2-propynyl (propargyl) are preferred.

In the formula (1), examples of the “aryl group” of the optionally substituted aryl group represented by R ₁ , R ₂ , R ₃ and R ₄ include phenyl, naphthyl and the like. preferable.

In the formula (1), examples of the “aralkyl group” of the optionally substituted aralkyl group represented by R ₁ , R ₂ , R ₃ and R ₄ include benzyl, phenethyl, 2-methylbenzyl, 4 -Methylbenzyl, (alpha) -methylbenzyl, 2-vinyl phenethyl, 4-vinyl phenethyl etc. are mentioned, benzyl is preferable.

In the formula (1), the “alkoxy group” of the optionally substituted alkoxy group represented by R ₁ , R ₂ , R ₃ and R ₄ preferably has 1 to 6 carbon atoms, more preferably 1 To 3 or a linear or branched alkoxy group, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, tert-butoxy, pentyloxy, hexyloxy and the like, Methoxy and ethoxy are preferred.

In the above formula (1), the alkyl group, aryl group, alkenyl group, alkynyl group, aralkyl group, and alkoxy group represented by R ₁ , R ₂ , R ₃ , and R ₄ are 1 or 2 at substitutable positions. It may be substituted with the above substituents.
Examples of such a substituent include a halogen atom (for example, fluorine atom, chlorine atom, bromine atom), an alkyl group having 1 to 6 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl), aryl groups (eg, phenyl, naphthyl), alkenyl groups (eg, ethenyl, 1-propenyl, 2-propenyl), alkynyl groups (eg, ethynyl, 1-propynyl, 2-propynyl) , Aralkyl groups (for example, benzyl, phenethyl), alkoxy groups (for example, methoxy, ethoxy) and the like.

[Physical properties of polyphenylene ether]
(purity)
The color index (CI) can be used as an indicator of the purity of polyphenylene ether.
The color index of polyphenylene ether is determined as follows.
A polyphenylene ether resin is used as a chloroform solution having a polyphenylene ether concentration of 0.05 g / mL.
Into a quartz cell having a cell length of 1 cm, the same chloroform as that used for dissolving the polyphenylene ether is put, and the absorbance of pure chloroform is measured with ultraviolet rays (wavelength 480 nm) to obtain an absorbance of 0.
A chloroform solution of the above polyphenylene ether is placed in the same cell, and the absorbance at 480 nm is measured.
The absorbance of the pure chloroform is subtracted from the absorbance of the polyphenylene ether solution and divided by the polyphenylene ether concentration in the polyphenylene ether solution to obtain C.I. I is determined.
It can be seen that the larger the color index value, the more colored, and the smaller the color index value, the higher the purity of the polyphenylene ether.
In order to obtain polyphenylene ether having high purity and excellent toning properties, the color index value is preferably as small as possible, specifically 1.0 or less, more preferably 0.6 or less, and further preferably 0.4 or less. preferable.

(Loose apparent specific gravity)
The loose apparent specific gravity of the polyphenylene ether of this embodiment is preferably 0.4 or more.
Thereby, it becomes excellent in the conveyance efficiency at the time of packing and conveying in a container, the meterability at the time of handling polyphenylene ether, and the powder handling property at the time of melt kneading. The loose apparent specific gravity is more preferably 0.45 or more, further preferably 0.48 or more, and even more preferably 0.5 or more.

(Dispersity)
The degree of dispersion of the polyphenylene ether of the present embodiment is an index that represents the scattering property and dust generation property of the powder, and the degree of dispersion is preferably 60% or less from the viewpoint of the handleability of the powder.
When the dispersity is 60% or less, for example, at the time of injection into an equal feeder at the time of melt-kneading, it is possible to suppress dust retention due to scattering and dust generation.
The degree of dispersion is more preferably 55% or less, and even more preferably 50%. Thereby, scattering and dust generation properties can be suppressed, so that from the viewpoint of powder handling, 55% or less. Preferably it is 50% or less.

The degree of dispersion, which is an index representing the powder dispersibility and dust generation, can be measured using, for example, a powder tester (manufactured by Hosokawa Micron Corporation: Powder Tester TYPE PT-E).
10 g of a sample for measurement is put in a hopper part at the upper part of the dispersity measuring unit attached to the powder tester, and a watch glass is placed at the lower part of the measuring unit. After that, by pushing down the lever attached to the hopper, the shutter installed at the bottom of the hopper opens sideways, and the sample falls on the watch glass. The weight of the sample remaining on the watch glass is weighed, and the degree of dispersion is determined by the following equation.
Dispersity = (10−weight of sample remaining on watch glass (g)) × 10 (%)
The lower the degree of dispersion, the weaker the scattering and dusting tendency, and the better the powder handling.

[Production method of polyphenylene ether]
The polyphenylene ether represented by the above formula (1) can be produced by polymerizing a phenol compound described later.
(Phenol compound)
For example, o-cresol, 2,6-dimethylphenol, 2-ethylphenol, 2-methyl-6-ethylphenol, 2,6-diethylphenol, 2-n-propylphenol, 2-ethyl-6-n-propyl Phenol, 2-methyl-6-chlorophenol, 2-methyl-6-bromophenol, 2-methyl-6-isopropylphenol, 2-methyl-6-n-propylphenol, 2-ethyl-6-bromophenol, 2 -Methyl-6-n-butylphenol, 2,6-di-n-propylphenol, 2-ethyl-6-chlorophenol, 2-methyl-6-phenylphenol, 2-phenylphenol, 2,6-diphenylphenol, 2,6-bis- (4-fluorophenyl) phenol, 2-methyl-6-tolylphenol 2,6-ditolylphenol, 2,5-dimethylphenol, 2,3,6-trimethylphenol, 2,5-diethylphenol, 2-methyl-5-ethylphenol, 2-ethyl-5-methylphenol, 2 -Allyl-5-methylphenol, 2,5-diallylphenol, 2,3-diethyl-6-n-propylphenol, 2-methyl-5-chlorophenol, 2-methyl-5-bromophenol, 2-methyl- 5-isopropylphenol, 2-methyl-5-n-propylphenol, 2-ethyl-5-bromophenol, 2-methyl-5-n-butylphenol, 2,5-di-n-propylphenol, 2-ethyl- 5-chlorophenol, 2-methyl-5-phenylphenol, 2,5-diphenylphenol, 2,5-bis- 4-fluorophenyl) phenol, 2-methyl-5-tolylphenol, 2,5-ditolylphenol, 2,6-dimethyl-3-allylphenol, 2,3,6-triallylphenol, 2,3,6 -Tributylphenol, 2,6-di-n-butyl-3-methylphenol, 2,6-di-t-butyl-3-methylphenol, 2,6-dimethyl-3-n-butylphenol, 2,6-dimethyl -3-t-butylphenol and the like.
In particular, 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-diphenylphenol, 2,3,6-trimethylphenol, and 2,5-dimethylphenol are preferable because they are inexpensive and easily available. 2,6-dimethylphenol and 2,3,6-trimethylphenol are more preferable.
The said phenol compound may be used independently or may be used in combination of 2 or more type.
For example, a method using a combination of 2,6-dimethylphenol and 2,6-diethylphenol, a method using a combination of 2,6-dimethylphenol and 2,6-diphenylphenol, 2,3,6-trimethylphenol And a method using a combination of 2,5-dimethylphenol and a method using a combination of 2,6-dimethylphenol and 2,3,6-trimethylphenol. The mixing ratio can be arbitrarily selected. In addition, the phenolic compounds used contain a small amount of m-cresol, p-cresol, 2,4-dimethylphenol, 2,4,6-trimethylphenol, etc., which are contained as by-products during production. May be.

(Polymerization method)
The polyphenylene ether of this embodiment can be polymerized by (precipitation precipitation polymerization) or (solution polymerization) described later.
Generally, when polyphenylene ether having a narrow molecular weight distribution is obtained only by the polymerization step, it is preferable to select precipitation polymerization.
In the case of solution polymerization, as shown in the examples described later, it is necessary to perform a dissolution step, a concentration step, and a precipitation step, and to remove the low molecular component and high molecular weight component in a subsequent step.
The concentration of the raw material phenol compound in the polymerization step is not particularly limited, but in the case of precipitation precipitation polymerization, it is preferably 10 to 50% by mass and more preferably 15 to 30% by mass with respect to the entire polymerization solution. . In the case of solution polymerization, 10 to 30% by mass is preferable.
In particular, in precipitation polymerization, the phenol compound concentration within the above range is preferable because the characteristics of precipitation polymerization are easily exhibited. Further, the amount of polymer with respect to all solvents is large, and the target product can be produced efficiently.
In addition, the characteristic of the said precipitation polymerization means the superposition | polymerization form from which precipitation of polyphenylene ether is obtained in the said density | concentration range. Specifically, as the polymerization of polyphenylene ether proceeds, a sufficiently high molecular weight precipitates, and an insufficient one is in a dissolved state.
In the precipitated polyphenylene ether, the movement of the molecular chain is suppressed, and the catalyst is dissolved in the mixed solvent. Therefore, it is theoretically considered that the reaction rate becomes slow due to a solid-liquid reaction.
On the other hand, polyphenylene ether having a molecular weight that is not yet sufficient in a dissolved state maintains its reaction rate, and when the polymerization proceeds and reaches a high molecular weight sufficient for precipitation, it precipitates. That is, theoretically, the molecular weight distribution is considered to become narrower, which is preferable as a method for producing the polyphenylene ether of this embodiment.
Furthermore, since polyphenylene ether precipitates during polymerization, the viscosity in the system gradually decreases, the monomer concentration (phenol compound concentration) during polymerization can be increased, and further, the precipitated polyphenylene ether can be filtered off. It can be easily removed and has the advantage that it can be greatly simplified in the process.

(Precipitation polymerization)
In the production process of polyphenylene ether, when precipitation precipitation polymerization is performed, the polymerization process is divided into the following stages of the initial polymerization, the middle polymerization, and the late polymerization.
Polymerization initial period: The 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.
In each of the above stages, the time until the precipitation and the time until the slurry is stabilized differ depending on the amount of the good solvent, the monomer type, and the monomer concentration.

The precipitation state of the polymer can be visually observed as appropriate.
Specific examples include a method of visually observing the polymer deposition state from a viewing window of a predetermined reactor, and a method of visually observing the deposition state by extracting the polymer solution from a sampling port into a transparent container such as glass.
As a guideline for starting the visual observation of the state of the polymer, the polymerization rate preferably reaches 80%, although it depends on the amount of the phenol compound contained in the polymerization system and the amount of the good or poor solvent for the polyphenylene ether. Thereafter, more preferably, after the polymerization rate reaches 70%, and more preferably after the polymerization rate reaches 50%, the observation of the polymer is started with attention being paid to the precipitation of the polymer.

  In the step of polymerizing the polyphenylene ether of the present embodiment, after the precipitation in the polymerization solvent is observed, the polymerization is continued while maintaining the precipitation in the middle of the polymerization, and the polymerization is completed in the later stage of the polymerization. Is preferred.

Here, the time required from the time when the polymerization is started until the precipitation is observed by the above observation is defined as a residence time T1, and the time required to complete the polymerization from the time after the precipitation is observed is defined as a retention time T2.
These times “T1” and “T2” have different definitions depending on the actual method for producing polyphenylene ether.
These definitions are shown below.
<In case of batch reaction>
T1: Time from the start of introducing the oxygen-containing gas until the precipitation can be visually confirmed.
T2: Time from visual confirmation of precipitation until completion of polymerization.
<In the case of continuous operation, the raw material and oxygen-containing gas are always flowing, and when two or more polymerization tanks are used>
T1: Time obtained by dividing the raw material supply rate from the total capacity of the tank in which polymerization is continued in a solution state.
T2: Time obtained by dividing the raw material supply rate from the total capacity of the tank in which polymerization is continued in the precipitated state.

In the step of polymerizing the polyphenylene ether of the present embodiment, the ratio of the residence time (T2 / T1) is preferably in the range of 0.1 to 30, more preferably in the range of 0.3 to 20, Preferably it is the range of 0.5-15.
If the residence time ratio (T2 / T1) is less than 0.1, irregular shaped particles may be generated during precipitation, and if the residence time ratio (T2 / T1) ratio is 30 or more, Although depending on the polymerization time until the precipitation starts, the polymerization time for obtaining the polyphenylene ether becomes long, so that practically sufficient production efficiency cannot be obtained.

In the process of polymerizing the polyphenylene ether of this embodiment, the phenol compound used for the polymerization is completely present in the polymerization tank from the beginning of the polymerization, and the polymerization is completed, and the polymerization is completed while sequentially adding the phenol compound during the polymerization. Any of the method of polymerizing and polymerizing polyphenylene ether continuously while supplying raw materials can be applied.
In particular, in order to stably obtain a large amount of uniform polyphenylene ether, a method of continuously polymerizing polyphenylene ether is preferable. A polyphenylene ether component having a molecular weight of 8000 or less is less than 20% by mass, and a polyphenylene ether component having a molecular weight of 50,000 or more is preferably used. Polyphenylene ether having a content of less than 20% by mass can be produced efficiently.

(Polymerization temperature in precipitation polymerization)
The polymerization temperature in the step of polymerizing the polyphenylene ether of this embodiment is shown below.
The polymerization temperature before precipitation is preferably 0 ° C to 50 ° C, more preferably 10 ° C to 40 ° C, and further preferably 20 ° C to 40 ° C. If the temperature before precipitation is too low, the polymerization reaction may not proceed easily.
Moreover, 0 to 100 degreeC is preferable, as for the polymerization temperature after precipitation, 10 to 80 degreeC is more preferable, 15 to 70 degreeC is further more preferable, and 20 to 60 degreeC is still more preferable. If the temperature after precipitation is too high, volatilization of the solvent used for polymerization becomes violent and the load on the cooling and reflux equipment increases.

(Solution polymerization)
When producing polyphenylene ether, a polymerization method in which polyphenylene ether is dissolved in a good solvent used for polymerization during and at the end of polymerization is called solution polymerization.
When polyphenylene ether is precipitated as the polymerization progresses, select a polymerization solvent that raises the temperature at the beginning of polymerization or during polymerization, increases the amount of good solvent for the monomer, adds monomer during polymerization, or does not precipitate By performing a treatment such as the above, polymerization in a solution state can be completed.
After the polymerization is completed, the polyphenylene ether can be isolated by a method such as adding a poor solvent to the polymerization solution after the polymerization, or drying the polymerization solution.

(Method for adjusting the molecular weight of polyphenylene ether)
After the polyphenylene ether is produced, when the polyphenylene ether having a molecular weight of 8000 or less is contained in an amount of 20% by mass or more, or when the polyphenylene ether having a molecular weight of 50,000 or more is contained in an amount of 20% by mass or more, the molecular weight can be adjusted by the following method.
For example, a method of dissolving polyphenylene ether in a good solvent and reprecipitating it with a poor solvent and isolating it, or washing with a mixed solvent of a good solvent and a poor solvent can be applied.
Since these methods can adjust the molecular weight depending on the treatment temperature, they can be used as a method for adjusting the molecular weight of polyphenylene ether. However, there is a high possibility that the reduced unnecessary components cause polymer loss and the yield decreases. Therefore, the method of producing the polyphenylene ether of this embodiment in the polymerization stage without using the molecular weight adjusting method is preferable from the viewpoint of producing the polyphenylene ether efficiently.

(Oxygen-containing gas)
In the polymerization process of the polyphenylene ether of this embodiment, both precipitation precipitation polymerization and solution polymerization are performed while supplying an oxygen-containing gas.
As the 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 system pressure during the polymerization reaction may be ordinary pressure, but can be used under reduced pressure or increased pressure 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. .

(Additive)
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)
As the catalyst used for producing the polyphenylene ether of the present embodiment, a known catalyst system generally used for producing polyphenylene ether can be used.
For example, there are transition metal ions having oxidation-reduction ability and amine compounds capable of complexing with the metal ions. Specifically, a catalyst system comprising a copper compound and an amine, and a manganese compound and an amine. Examples include a catalyst system and a catalyst system composed of a cobalt compound and an amine.

Since the polymerization reaction proceeds efficiently under some alkaline conditions, some alkali or further amine may be added thereto.
As a suitable catalyst in the production process of the polyphenylene ether of this embodiment, a catalyst containing a copper compound, a halogen compound and a diamine compound represented by the following formula (2) as constituent components can be mentioned.

In the above formula _{(2), R 5, R} 6, R 7 and R ₈ are each independently hydrogen atom, selected from the group consisting of linear or branched alkyl group having 1 to 6 carbon atoms Indicates either. Note that all are not hydrogen at the same time. R ₉ represents a linear or branched alkylene group having 2 to 5 carbon atoms.

As a 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, and cuprous nitrate.
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.

Moreover, you may synthesize | combine these copper compounds from the halogen or acid corresponding to an oxide (for example, cuprous oxide), carbonate, a hydroxide, etc.
For example, it can be synthesized by mixing cuprous oxide and a halogen compound (for example, a solution of hydrogen halide).
Examples of the halogen compound include hydrogen chloride, hydrogen bromide, hydrogen iodide, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, potassium iodide, tetramethylammonium chloride, and 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.
These halogen compounds may be used alone or in combination of two or more.
Preferred halogen compounds are an aqueous solution of hydrogen chloride and an aqueous solution of hydrogen bromide.
Although the usage-amount of these compounds is not specifically limited, As a halogen atom with respect to the molar amount of a copper atom, 2 times or more and 20 times or less are preferable, As a preferable usage-amount of a copper atom with respect to 100 mol of the phenol compound used Is in the range of 0.02 to 0.6 mol.

Examples of the diamine compound represented by the above formula (2) include N, N, N ′, N′-tetramethylethylenediamine, N, N, N′-trimethylethylenediamine, N, N′-dimethylethylenediamine, and N, N. -Dimethylethylenediamine, N-methylethylenediamine, N, N, N ', N'-tetraethylethylenediamine, N, N, N'-triethylethylenediamine, N, N'-diethylethylenediamine, N, N-diethylethylenediamine, N-ethyl Ethylenediamine, N, N-dimethyl-N′-ethylethylenediamine, N, N′-dimethyl-N-ethylethylenediamine, Nn-propylethylenediamine, N, N′-di-n-propylethylenediamine, Ni-propylethylenediamine N, N′-Di i-propylethylene di Min, Nn-butylethylenediamine, N, N′-di-n-butylethylenediamine, Ni-butylethylenediamine, N, N′-di-butylethylenediamine, Nt-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'-tetramethyl-1, 5-diaminopentane And the like.
Preferred diamine compounds are those in which the alkylene group (R ₉ ) connecting two nitrogen atoms has 2 or 3 carbon atoms.
Although the usage-amount of these diamine compounds is not specifically limited, It is used in 0.01 mol-10 mol with respect to 100 mol of phenol compounds used normally.

The other components constituting the polymerization catalyst will be described.
In addition to the catalyst components described above, for example, a tertiary monoamine compound or a secondary monoamine compound may be contained alone or in combination in the polymerization catalyst used in the polymerization step.
The tertiary monoamine compound is an aliphatic tertiary amine containing an alicyclic tertiary amine.
Examples include trimethylamine, triethylamine, tripropylamine, tributylamine, triisobutylamine, dimethylethylamine, dimethylpropylamine, allyldiethylamine, dimethyl-n-butylamine, diethylisopropylamine, N-methylcyclohexylamine and the like.
These tertiary monoamines 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 the phenol compound to be polymerized.
A secondary aliphatic amine can be applied as the secondary monoamine compound.
For example, dimethylamine, diethylamine, di-n-propylamine, di-i-propylamine, di-n-butylamine, di-i-butylamine, 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. For example, 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-2-methylaniline, N-methyl-2,6-dimethylaniline, diphenylamine and the like Can be mentioned. 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 100 mol of phenol compounds to superpose | polymerize.

[Recovery of polyphenylene ether]
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, the catalyst is deactivated.
Thereafter, since the polymerization solution at the end of the polymerization is in a state where polyphenylene ether is precipitated, repeated washing treatment is performed using a solution mainly composed of a solvent having low polyphenylene ether solubility for the purpose of washing and removing the catalyst. Preferably it is done.
Thereafter, the polyphenylene ether can be recovered as a powder by performing a drying treatment using various dryers.

(Method of drying polyphenylene ether)
The drying treatment is performed at a temperature of at least 60 ° C., preferably 80 ° C. or higher, more preferably 120 ° C. or higher, further preferably 140 ° C. or higher, and even more preferably 150 ° C. or higher.
If the polyphenylene ether is dried at 60 ° C. or lower, the content of aromatic hydrocarbons in the polyphenylene ether may not be efficiently suppressed to less than 1.5% by mass.
In order to obtain polyphenylene ether 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 the drying, etc. are effective. In particular, the drying rate is increased. The method is preferable from the viewpoint of production efficiency.
The drying process preferably uses a mixer. Examples of the mixer 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.
Specific examples include a paddle dryer, a rotary dryer, an SC processor, a KID dryer, a ribbon mixing dryer, a rotary kiln, and a multi-fin processor. Particularly, a stirring dryer is preferable, and a paddle dryer and an SC processor are preferable. According to these, it is possible to produce a polyphenylene ether excellent in powder handling property, in which scattering and dust generation properties are further suppressed.

The polyphenylene ether of this embodiment can be melt-kneaded with conventionally known thermoplastic resins and thermosetting resins.
Examples of the thermoplastic resin and the thermosetting resin include polyethylene, polypropylene, thermoplastic elastomer, polystyrene, acrylonitrile / styrene resin, acrylonitrile / butadiene / styrene resin, methacrylic resin, vinyl chloride, polyamide, polyacetal, ultrahigh molecular weight polyethylene, Polybutylene terephthalate, polymethylpentene, polycarbonate, polyphenylene sulfide, polyether ketone, liquid crystal polymer, polytetrafluoroethylene, polyetherimide, polyarylate, polysulfone, polyethersulfone, polyamideimide, phenol, urea, melamine, unsaturated Examples thereof include resins such as polyester, alkyd, epoxy, diallyl phthalate, and bismaleimide.
At the time of melt kneading, it is more preferable to add conventionally known additives and thermoplastic elastomers for the purpose of imparting effects such as conductivity, flame retardancy and impact resistance.
Further, when producing a resin composition using the polyphenylene ether of the present embodiment, other additives such as plasticizers, stabilizers, modifiers, ultraviolet absorbers, flame retardants, colorants, mold release agents and Fibrous reinforcing agents such as glass fibers and carbon fibers, and fillers such as glass beads, calcium carbonate, talc, and clay may be added.
Stabilizers and modifiers include phosphites, hindered phenols, sulfur-containing antioxidants, alkanolamines, acid amides, dithiocarbamic acid metal salts, inorganic sulfides, metal oxides, carboxylic anhydrides , Dienophile compounds such as styrene and stearyl acrylate, and epoxy group-containing compounds. These additives may be used alone or in combination of two or more.
As a method for mixing the components constituting the resin composition, for example, a solution blending and degassing method, an extruder, a heating roll, a Banbury mixer, a kneader, a Henschel mixer and the like can be used.

Hereinafter, the present invention will be specifically described with reference to examples and comparative examples.
First, measurement methods such as physical properties and characteristics applied to Examples and Comparative Examples are shown below.

(1) Quantification of components having a molecular weight of 8000 or less and components having a molecular weight of 50,000 or more, measurement of weight average molecular weight (Mw) / number average molecular weight (Mn) As a measuring device, Gel Permeation Chromatography System 21 manufactured by Showa Denko K.K. A calibration curve was prepared using standard polystyrene, and measurement was performed using this calibration curve.
The molecular weight of standard polystyrene used was 3650000, 217000, 1090000, 681000, 204000, 52000, 30200, 13800, 3360, 1300, 550.
As the column, two K-805L manufactured by Showa Denko KK were connected in series.
As the solvent, chloroform was used, the solvent flow rate was 1.0 mL / min, and the column temperature was 40 ° C.
As a measurement sample, a 1 g / L chloroform solution of polyphenylene ether was prepared and used.
The UV wavelength of the detector was 254 nm for standard polystyrene and 283 nm for polyphenylene ether.

(2) Confirmation of eyes A polyphenylene ether resin composition was produced using the polyphenylene ethers of Examples 1 to 5 and Comparative Examples 1 to 7 described later as raw materials.
As the manufacturing equipment, “ZSK25 twin screw extruder” manufactured by Werner & Pfleiderer, Germany (10 barrels, screw diameter 25 mm, kneading disk L: 2, kneading disk R: 6, kneading disk N: 2 The raw material was supplied from the most upstream part (top feed) of the twin-screw extruder.
In this twin-screw extruder, a cylinder into which a screw is inserted is constituted by blocks (barrels) 1 to 10, and the most upstream raw material supply port is a barrel 1, which is an outlet of a melt-kneaded resin composition. The barrel 10 is immediately before.
The resin composition was obtained by melt-kneading under conditions of a cylinder temperature of 310 ° C. and a screw rotation speed of 250 rpm.
At this time, the eyes generated on the die were visually evaluated.
X: When a large amount of eyes and eyes are observed (bad)
Δ: When a small amount of eyes and eyes are observed (standard)
◯: When eyes and nibs are not observed (good)

(3) Confirmation of gel 1 g of a molten resin of polyphenylene ether obtained by using the “ZSK25 twin screw extruder” in (2) above was placed in a 50 mL glass bottle and dissolved in 10 mL of chloroform.
The dissolved chloroform solution was visually observed to confirm the presence or absence of gel.
Moreover, when the gel was not observed visually, a syringe permeation test was performed.
In this syringe permeation test, 2 mL of the chloroform solution was sucked up into a 3 mL syringe, and a Millex (registered trademark) -LG filter (pore size: 0.20 μm) manufactured by Millipore was attached to the tip of the syringe to filter the solution. It was confirmed.
It was found that it was difficult to pass through the filter when a gel that could not be visually confirmed was generated.
The presence or absence of gel was evaluated according to the following criteria.
×: When a large amount of gel is visually confirmed Δ: When a small amount of gel is visually confirmed ○: When the gel is not visually confirmed, but clogging of the filter occurs in the syringe permeation test ◎: The gel is visually observed If the filter does not clog in the syringe permeation test

(4) Evaluation of scattering / dust generation The scattering / dust generation of polyphenylene ethers of Examples 1 to 5 and Comparative Examples 1 to 7, which will be described later, was evaluated.
As an evaluation apparatus, a powder tester (manufactured by Hosokawa Micron Corporation: powder tester TYPE PT-E) was used.
10 g of a measurement sample was put in a hopper portion at the top of the dispersity measurement unit attached to the powder tester, and a watch glass was placed at the bottom of the measurement unit.
Thereafter, the lever attached to the hopper was pushed down, whereby the shutter installed at the bottom of the hopper was opened sideways, and the measurement sample dropped onto the watch glass.
The weight of the sample remaining on the watch glass was weighed, and the degree of dispersion was determined by the following formula.
Dispersity = (10−weight of sample remaining on watch glass (g)) × 10 (%)
It was determined that the lower the degree of dispersion, the weaker the scattering and dusting tendency.

(5) Quantification of residual metal Using an atomic absorption photometer (AA6650, manufactured by Shimadzu Corporation), the residual metal concentration in the polyphenylene ethers of Examples 1 to 5 and Comparative Examples 1 to 7 described later was measured.

(6) Measurement of color index (CI) The polyphenylene ether powders of Examples 1 to 5 and Comparative Examples 1 to 7 described later are dissolved in chloroform so that the polyphenylene ether concentration becomes 0.05 g / mL. Prepared.
The same chloroform as the polyphenylene ether-dissolving chloroform was added to a quartz cell having a cell length of 1 cm, irradiated with ultraviolet light having a wavelength of 480 nm, and the absorbance of pure chloroform was measured.
Next, the chloroform in the quartz cell was discarded, washed and dried. Subsequently, the chloroform solution of the above polyphenylene ether was added, irradiated with ultraviolet rays having a wavelength of 480 nm, and the absorbance of the chloroform solution was measured.
In addition, when gel was contained in the chloroform solution for measurement, consideration was given so that the gel would not enter the quartz cell as much as possible.
The absorbance of pure chloroform is subtracted from the absorbance of the obtained polyphenylene ether solution and divided by the polyphenylene ether concentration in the polyphenylene ether solution to obtain C.I. I.

(7) Molding fluidity (SSP)
Using the polyphenylene ether of Examples 1 to 5 and Comparative Examples 1 to 7 which will be described later, an injection molding machine “IS-80EPN (molding temperature 330 ° C., mold temperature 100 ° C.)” manufactured by Toshiba Machine Co., Ltd. has a thickness of 0.32 cm. The short shot pressure (SSP) of the dumbbell molded piece was measured with a gauge pressure.
If the molding fluidity (SSP) was 6 (MPa) or less, it was judged to be practically good.

(8) Measurement of glass transition temperature The glass transition temperatures of polyphenylene ethers of Examples 1 to 5 and Comparative Examples 1 to 7 described later were measured using a differential scanning calorimeter DSC (manufactured by PerkinElmer-Pyris 1).
In a nitrogen atmosphere, after heating from room temperature to 280 ° C. at a temperature rising rate of 20 ° C. per minute, the temperature was decreased to 50 ° C. at 40 ° C. per minute, and then the glass transition temperature was measured at a temperature rising rate of 20 ° C. per minute.

(9) Measurement of reduced viscosity (ηsp / c) and | (ηB−ηA) / ηA | The polyphenylene ethers of Examples 1 to 5 and Comparative Examples 1 to 7 described later are referred to as polyphenylene ether (A). On the other hand, what is subjected to hot press treatment (conditions of 310 ° C. × 20 minutes × 10 MPa) is referred to as polyphenylene ether (B) after heating.
The reduced viscosity (ηsp / c) at 30 ° C. was determined using a polyphenylene ether (A) or polyphenylene ether (B) as a 0.5 g / dL chloroform solution using an Ubbelohde viscosity tube.
The unit is dL / g.
The relational expression | (ηB−ηA) / ηA | was calculated with the reduced viscosity of the polyphenylene ether (A) as ηA and the reduced viscosity of the polyphenylene ether (B) as ηB.

(10) Quantification of aromatic hydrocarbons contained in polyphenylene ether The quantification of aromatic hydrocarbons contained in the polyphenylene ethers of Examples 1 to 5 and Comparative Examples 1 to 7 described later is performed by capillary column: Product name HR-1 (Shinwa) Gas chromatograph: Product name GC-2010 (manufactured by Shimadzu Corporation), detector: FID, and a standard calibration curve method using mesitylene as an internal standard substance were attached.

(11) Evaluation of strand folding resistance Using the polyphenylene ethers of Examples 1 to 5 and Comparative Examples 1 to 7 described later, strands of a polyphenylene ether resin composition were produced.
As the manufacturing equipment, “ZSK25 twin screw extruder” manufactured by Werner & Pfleiderer, Germany (10 barrels, screw diameter 25 mm, kneading disk L: 2, kneading disk R: 6, kneading disk N: 2 The raw material was supplied from the most upstream part (top feed) of the twin-screw extruder.
In this twin-screw extruder, a cylinder into which a screw is inserted is constituted by blocks (barrels) 1 to 10, and the most upstream raw material supply port is a barrel 1, which is an outlet of a melt-kneaded resin composition. The barrel 10 is immediately before.
The resin composition strand was obtained by melt-kneading under conditions of a cylinder temperature of 310 ° C. and a screw rotation speed of 250 rpm.
The strand was taken up with a strand cutter, the take-up speed was adjusted, and the strand diameter was adjusted to 3 mm.
The strand which became 3 mm was partly cut out with a pruning scissors and used as a folding resistance evaluation sample of about 15 cm.
This sample was folded in half by hand and evaluated for folding resistance.
When the number of folding times was 1 or more, the folding test was performed for the second and subsequent times by folding in the direction opposite to the direction once folded, and evaluated according to the following criteria. The higher the number of times, the higher the mechanical strength.
×: Fold resistance 0 times (bad)
Δ: Fold-resistant once (standard)
○: 2 or more folding times (good)

[Example 1]
A 40 liter 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 was added to a 0.5 L / min. 4.02 g of cupric oxide, 30.224 g of 47% aqueous hydrogen bromide, 9.684 g of di-t-butylethylenediamine, 46.88 g of di-n-butylamine while blowing nitrogen gas at a flow rate. 68 g of butyldimethylamine, 20.65 kg of toluene, 3.12 kg of 2,6-dimethylphenol were added, and the mixture was stirred until it became a homogeneous solution and the internal temperature of the reactor reached 25 ° C.

Next, dry air was started to be introduced from the sparger at a rate of 32.8 NL / min into the polymerization tank, and polymerization was started.
Aeration was performed for 85 minutes to control the internal temperature at the end of polymerization to 40 ° C.
The polymerization solution at the end of the polymerization was in a solution state.

The aeration of the dry air was stopped, 10 kg of 2.5% aqueous solution of ethylenediaminetetraacetic acid tetrasodium salt (a reagent manufactured by Dojindo Laboratories) was added to the polymerization mixture, and the polymerization mixture was stirred at 70 ° C. for 150 minutes and then allowed to stand. The organic phase and the aqueous phase were separated by liquid-liquid separation.
After the obtained organic phase was brought to 50 ° C., methanol was added in excess to precipitate polyphenylene ether, followed by filtration. The remaining polyphenylene ether was dispersed in excess methanol, stirred at 50 ° C. for 30 minutes, and then filtered again. .
This operation was repeated twice to obtain wet polyphenylene ether.

The white slurry-like polyphenylene ether was filtered, and the remaining wet polyphenylene ether was recovered.
Thereafter, vacuum drying treatment was performed at 140 ° C. and 1 mmHg for 1 hour to obtain polyphenylene ether powder.

20 parts by mass of this polyphenylene ether powder, 40 parts by mass of toluene, and 60 parts by mass of methanol were mixed to prepare a slurry liquid.
The slurry was heated to 60 ° C., stirred for 20 minutes, and then returned to room temperature.
This slurry liquid was filtered, and the wet polyphenylene ether remaining in the filter was recovered.
Then, it put into the cut disk dryer, and it was made to dry in 150 degreeC and nitrogen atmosphere for 5 hours, and obtained the target polyphenylene ether powder.
When the filtrate was completely volatilized, polyphenylene ether was slightly precipitated, thereby removing the low molecular weight polyphenylene ether component.
The evaluation results of (1) to (11) described above are shown in Table 1 below.

[Example 2]
1. A sparger for introducing an oxygen-containing gas, a stirring turbine blade and a baffle are provided at the bottom of the polymerization tank, a reflux condenser is provided at the vent gas line at the top of the polymerization tank, and an overflow line to the second polymerization tank is provided at the side of the polymerization tank. While blowing nitrogen gas at a flow rate of 500 mL / min into a 6 liter jacketed first polymerization tank, 0.239 g of cupric chloride dihydrate, 1.052 g of 35% hydrochloric acid, 3.441 g of di- n-Butylamine, 9.124 g N, N, N ′, N′-tetramethylpropanediamine, 444.4 g xylene, 169.8 g n-butanol, 509.5 g methanol were charged.

  Similarly, a sparger for introducing an oxygen-containing gas, a stirring turbine blade and a baffle are provided at the bottom of the polymerization tank, a reflux condenser is provided in the vent gas line at the top of the polymerization tank, and an overflow line to the washing tank is provided on the side of the polymerization tank. 1006.4 g of xylene, 377.4 g of n-butanol, and 509.5 g of methanol were put into a 0.0-liter jacketed second polymerization tank while nitrogen gas was blown at a flow rate of 1000 mL / min.

  Further, a 6.0 liter first raw material tank equipped with a reflux condenser in a line that can be fed to the first polymerization tank by a plunger pump, a stirring turbine blade and a vent gas line in the upper part of the tank, 0.642 g cupric chloride dihydrate, 2.827 g 35% hydrochloric acid, 9.247 di-n-butylamine, 24.519 g N, N, N while blowing nitrogen gas at a flow rate of minutes. ', N'-tetramethylpropanediamine, 1194.3 g of xylene, 456.4 g of n-butanol, 1369.2 g of methanol, 920.0 g of 2,6-dimethylphenol were added and stirred to mix the liquids. .

  In addition, a 2.0 liter second raw material tank equipped with a recirculation cooler in a line that can be fed to both the first polymerization tank and the second polymerization tank by a plunger pump, a stirring turbine blade, and a vent gas line in the upper part of the tank While injecting nitrogen gas at a flow rate of 100 mL / min from the nitrogen gas inlet, 1200 g of xylene was added.

  In addition, since the preparation liquid in a 1st raw material tank and a 2nd raw material tank is reduced when it supplies to a polymerization tank, the thing of the said liquid composition was added to the 1st raw material tank and the 2nd raw material tank suitably.

Next, the polymerization solution is supplied from the first raw material tank to the vigorously stirred first polymerization tank at a flow rate of 19.42 g / min, and at the same time, oxygen is supplied from the sparger to the first polymerization tank at a rate of 329.42 mL / min. The introduction of.
Furthermore, at the same time as the overflow from the first polymerization tank to the second polymerization tank is started, xylene is supplied from the second raw material tank to the second polymerization tank at a flow rate of 0.111 g / min, and further from the sparger. Oxygen was introduced into the polymerization tank at a rate of 32.4 mL / min.
The amount of xylene that is a good solvent at this time is 2.5 parts by mass with respect to 100 parts by mass of 2,6-dimethylphenol.

The polymerization temperature was adjusted by passing a heating medium through the jacket so as to maintain 40 ° C. in both the first polymerization tank and the second polymerization tank.
The overflow from the second polymerization tank was collected in a collection container.
Thereafter, the polymerization was continued for 40 hours, the polymerization in the first polymerization tank and the second polymerization tank became stable, and polyphenylene ether was continuously obtained.
In addition, precipitation of polyphenylene ether did not occur in the first polymerization tank, and precipitation of polyphenylene ether was observed in the second polymerization tank.
Thereafter, the polymerization was further continued for 40 hours to complete the polymerization.

A 10% aqueous solution of ethylenediaminetetraacetic acid tripotassium salt (a reagent manufactured by Dojindo Laboratories) was added to the polyphenylene ether slurry in the recovery container obtained as described above, and the mixture was warmed to 50 ° C.
Next, hydroquinone (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added little by little, and the temperature was kept at 50 ° C. until the slurry polyphenylene ether became white.
The slurry-like polyphenylene ether that has turned white is filtered, and the remaining polyphenylene ether is sprinkled with methanol, washed, then placed in a cut disk dryer and dried at 150 ° C. under a nitrogen atmosphere for 5 hours. A powder was obtained.
The obtained polyphenylene ether was evaluated for the above (1) to (11). The evaluation results are shown in Table 1 below.

Example 3
Using a polyphenylene ether powder obtained by the same operation as in Example 2, a slurry liquid was prepared by mixing and dispersing 20 parts by mass of this polyphenylene ether, 40 parts by mass of xylene, and 60 parts by mass of methanol.
The slurry was heated to 60 ° C., stirred for 20 minutes, and returned to room temperature.
Thereafter, the slurry liquid was filtered, and the remaining polyphenylene ether in a wet state was recovered.
The wet polyphenylene ether was put in a cut disk dryer and dried at 150 ° C. in a nitrogen atmosphere for 5 hours to obtain the desired polyphenylene ether powder.
When the filtrate was completely volatilized, polyphenylene ether was slightly precipitated. Thereby, the low molecular weight polyphenylene ether component was removed.

Example 4
Using polyphenylene ether powder obtained by the same operation as in Example 2, 20 parts by mass of this polyphenylene ether powder was completely dissolved in 100 parts by mass of toluene at 55 ° C., and then 40 parts by mass of toluene was volatilized. A concentrated solution was obtained.
An excessive amount of methanol (140 parts by mass or more) corresponding to 7 times or more of the polyphenylene ether powder (20 parts by mass) was added to the concentrated liquid to reprecipitate polyphenylene ether.

The mixture was cooled to room temperature, and then filtered, and the residual wet polyphenylene ether was recovered.
The polyphenylene ether was put into a cut disk dryer and dried at 150 ° C. in a nitrogen atmosphere for 5 hours to obtain the desired polyphenylene ether powder.
When the filtrate was completely volatilized, polyphenylene ether was slightly precipitated. Thereby, the low molecular weight polyphenylene ether component was removed.

Example 5
Using polyphenylene ether powder obtained by the same operation as in Example 3, 20 parts by mass of polyphenylene ether powder was completely dissolved in 100 parts by mass of toluene at 55 ° C., and then 40 parts by mass of toluene was volatilized and concentrated. A liquid was obtained.
Methanol was added excessively to this concentrated liquid so that it might become 140 mass parts or more, and polyphenylene ether was reprecipitated.
The mixture was cooled to room temperature, and then filtered, and the residual wet polyphenylene ether was recovered.
The polyphenylene ether was put into a cut disk dryer and dried at 150 ° C. in a nitrogen atmosphere for 5 hours to obtain the desired polyphenylene ether powder.
When the filtrate was completely volatilized, polyphenylene ether was slightly precipitated. Thereby, the low molecular weight polyphenylene ether component was removed.

[Comparative Example 1]
A 40 liter 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 was added to a 0.5 L / min. 4.02 g of cupric oxide, 30.224 g of 47% aqueous solution of hydrogen bromide, 9.684 g of di-t-butylethylenediamine, 46.88 g of di-n-butylamine, 142 while blowing nitrogen gas at a flow rate. .68 g of butyldimethylamine, 20.65 kg of toluene, 3.12 kg of 2,6-dimethylphenol were added, and the mixture was stirred until it became a homogeneous solution and the internal temperature of the polymerization tank reached 25 ° C.

Next, dry air was introduced into the polymerization tank at a rate of 32.8 NL / min from a sparger and polymerization was started.
Aeration was performed for 85 minutes to control the internal temperature at the end of polymerization to 40 ° C.
The polymerization solution at the end of the polymerization was in a solution state.
Aeration of dry air was stopped, 10 kg of 2.5% aqueous solution of ethylenediaminetetraacetic acid tetrasodium salt (a reagent manufactured by Dojindo Laboratories) was added to the polymerization mixture, and the polymerization mixture was stirred at 70 ° C. for 150 minutes, and then allowed to stand. The organic phase and the aqueous phase were separated by liquid-liquid separation.
After the obtained organic phase was brought to 50 ° C., methanol was added in excess to precipitate polyphenylene ether, followed by filtration. The remaining polyphenylene ether was dispersed in excess methanol, stirred at 50 ° C. for 30 minutes, and then filtered again.
This operation was repeated twice to obtain wet polyphenylene ether.
This wet polyphenylene ether was put into a cut disk dryer and dried at 150 ° C. in a nitrogen atmosphere for 5 hours to obtain the desired polyphenylene ether powder.

[Comparative Example 2]
1. A sparger for introducing an oxygen-containing gas, a stirring turbine blade and a baffle are provided at the bottom of the polymerization tank, a reflux condenser is provided at the vent gas line at the top of the polymerization tank, and an overflow line to the second polymerization tank is provided at the side of the polymerization tank. 0.268 g of cupric chloride dihydrate, 1.181 g of 35% hydrochloric acid, 3.862 g of di-ethylene gas were blown into a 6-liter jacketed first polymerization tank at a flow rate of 500 mL / min. n-Butylamine, 10.241 g N, N, N ′, N′-tetramethylpropanediamine, 598.6 g xylene, 448.6 g n-butanol, 33.0 g methanol, 384.2 g 2,6 -Dimethylphenol was added.

  Similarly, a sparger for introducing an oxygen-containing gas, a stirring turbine blade and a baffle are provided at the bottom of the polymerization tank, a reflux condenser is provided in the vent gas line at the top of the polymerization tank, and an overflow line to the washing tank is provided on the side of the polymerization tank. 1006.4 g of xylene, 377.4 g of n-butanol, and 509.5 g of methanol were put into a 0.0-liter jacketed second polymerization tank while nitrogen gas was blown at a flow rate of 1000 mL / min.

  Further, a 6.0 liter first raw material tank equipped with a reflux condenser in a line that can be fed to the first polymerization tank by a plunger pump, a stirring turbine blade and a vent gas line in the upper part of the tank, 0.642 g cupric chloride dihydrate, 2.827 g 35% hydrochloric acid, 9.247 di-n-butylamine, 24.519 g N, N, N while blowing nitrogen gas at a flow rate of minutes. ', N'-tetramethylpropanediamine, 1433.1 g of xylene, 1074.1 g of n-butanol, 79.1 g of methanol, 920.0 g of 2,6-dimethylphenol were added, and the liquid was mixed by stirring. .

  In addition, a 2.0 liter second raw material tank equipped with a recirculation cooler in a line that can be fed to both the first polymerization tank and the second polymerization tank by a plunger pump, a stirring turbine blade, and a vent gas line in the upper part of the tank While injecting nitrogen gas at a flow rate of 100 mL / min from the nitrogen gas inlet, 1200.0 g of methanol was added.

In addition, since the preparation liquid in a 1st raw material tank and a 2nd raw material tank is reduced when it supplies to a polymerization tank, the thing of the said liquid composition was added to the 1st raw material tank and the 2nd raw material tank suitably.
Next, the charged liquid is supplied from the first raw material tank to the vigorously stirred first polymerization tank at a flow rate of 13.31 g / min. At the same time, oxygen is supplied from the sparger to the first polymerization tank at a rate of 237.6 mL / min. The introduction of.
Furthermore, at the same time as the overflow from the first polymerization tank to the second polymerization tank is started, the charged liquid is supplied from the second raw material tank to the second polymerization tank at a flow rate of 1.715 g / min. Oxygen was introduced into the bipolymerization tank at a rate of 79.2 mL / min.
At this time, the amount of xylene, which is a good solvent, is 0% by mass with respect to 2,6-dimethylphenol.

The polymerization temperature was adjusted by passing a heating medium through the jacket so as to maintain 40 ° C. in both the first polymerization tank and the second polymerization tank.
The overflow from the second polymerization tank was collected in a collection container.
Thereafter, the polymerization was continued for 40 hours, the polymerization in the first polymerization tank and the second polymerization tank became stable, and polyphenylene ether was continuously obtained.
In addition, precipitation of polyphenylene ether did not occur in the first polymerization tank, and precipitation of polyphenylene ether was observed in the second polymerization tank.
Thereafter, the polymerization was further continued for 40 hours to complete the polymerization.

A 10% aqueous solution of ethylenediaminetetraacetic acid tripotassium salt (a reagent manufactured by Dojindo Laboratories) was added to the polyphenylene ether slurry in the recovery container obtained as described above, and the mixture was warmed to 50 ° C.
Next, hydroquinone (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added little by little, and the temperature was kept at 50 ° C. until the slurry polyphenylene ether became white.
The slurry-like polyphenylene ether that has turned white is filtered, and the remaining polyphenylene ether is sprinkled with methanol, washed, then placed in a cut disk dryer and dried at 150 ° C. under a nitrogen atmosphere for 5 hours. A powder was obtained.
The obtained polyphenylene ether was evaluated for the above (1) to (11). The evaluation results are shown in Table 1 below.
In addition, when the inside of a 2nd polymerization tank was confirmed after completion | finish of superposition | polymerization, it was confirmed that polyphenylene ether has adhered in the tank. The thickness of the adhering polyphenylene ether was about 0.7 cm.

[Comparative Example 3]
1. A sparger for introducing an oxygen-containing gas, a stirring turbine blade and a baffle are provided at the bottom of the polymerization tank, a reflux condenser is provided at the vent gas line at the top of the polymerization tank, and an overflow line to the second polymerization tank is provided at the side of the polymerization tank. 0.268 g of cupric chloride dihydrate, 1.181 g of 35% hydrochloric acid, 3.862 g of di-ethylene gas were blown into a 6-liter jacketed first polymerization tank at a flow rate of 500 mL / min. n-Butylamine, 10.241 g N, N, N ′, N′-tetramethylpropanediamine, 533.8 g xylene, 228.8 g n-butanol, 317.7 g methanol, 384.2 g 2,6 -Dimethylphenol was added.

  Similarly, a sparger for introducing an oxygen-containing gas, a stirring turbine blade and a baffle are provided at the bottom of the polymerization tank, a reflux condenser is provided in the vent gas line at the top of the polymerization tank, and an overflow line to the washing tank is provided on the side of the polymerization tank. 1006.4 g of xylene, 377.4 g of n-butanol, and 509.5 g of methanol were put into a 0.0-liter jacketed second polymerization tank while nitrogen gas was blown at a flow rate of 1000 mL / min.

Further, a 6.0 liter first raw material tank equipped with a reflux condenser in a line that can be fed to the first polymerization tank by a plunger pump, a stirring turbine blade and a vent gas line in the upper part of the tank, 0.642 g cupric chloride dihydrate, 2.827 g 35% hydrochloric acid, 9.247 di-n-butylamine, 24.519 g N, N, N while blowing nitrogen gas at a flow rate of minutes. ', N'-tetramethylpropanediamine,
1278.0 g of xylene, 547.7 g of n-butanol, 760.7 g of methanol, and 920.0 g of 2,6-dimethylphenol were added and stirred to mix the liquid.

  In addition, a 2.0 liter second raw material tank equipped with a recirculation cooler in a line that can be fed to both the first polymerization tank and the second polymerization tank by a plunger pump, a stirring turbine blade, and a vent gas line in the upper part of the tank While injecting nitrogen gas at a flow rate of 100 mL / min from the nitrogen gas inlet, 1200.0 g of methanol was added.

In addition, since the preparation liquid in a 1st raw material tank and a 2nd raw material tank is reduced when it supplies to a polymerization tank, the thing of the said liquid composition was added to the 1st raw material tank and the 2nd raw material tank suitably.
Next, the charged liquid was supplied from the first raw material tank to the vigorously stirred first polymerization tank at a flow rate of 13.31 g / min, and at the same time oxygen from the sparger was supplied to the first polymerization tank at a rate of 221.7 mL / min. The introduction of.
Furthermore, at the same time as the overflow from the first polymerization tank to the second polymerization tank is started, the charged liquid is supplied from the second raw material tank to the second polymerization tank at a flow rate of 1.715 g / min. Oxygen was introduced into the bipolymerization tank at a rate of 95.0 mL / min.
At this time, the amount of xylene, which is a good solvent, is 0% by mass with respect to 2,6-dimethylphenol.

The polymerization temperature was adjusted by passing a heating medium through the jacket so as to maintain 40 ° C. in both the first polymerization tank and the second polymerization tank.
The overflow from the second polymerization tank was collected in a collection container.
Thereafter, the polymerization was continued for 40 hours, the polymerization in the first polymerization tank and the second polymerization tank became stable, and polyphenylene ether was continuously obtained.
In addition, precipitation of polyphenylene ether did not occur in the first polymerization tank, and precipitation of polyphenylene ether was observed in the second polymerization tank.
Thereafter, the polymerization was further continued for 40 hours to complete the polymerization.

A 10% aqueous solution of ethylenediaminetetraacetic acid tripotassium salt (a reagent manufactured by Dojindo Laboratories) was added to the polyphenylene ether slurry in the recovery container obtained as described above, and the mixture was warmed to 50 ° C.
Next, hydroquinone (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added little by little, and the temperature was kept at 50 ° C. until the slurry polyphenylene ether became white.
The slurry-like polyphenylene ether that has become white is filtered, and the remaining polyphenylene ether is sprinkled with methanol, washed, and then placed in a cut disk dryer and dried at 150 ° C. in a nitrogen atmosphere for 3 hours. A powder was obtained.
The obtained polyphenylene ether was evaluated for the above (1) to (11). The evaluation results are shown in Table 1 below.
In addition, when the inside of a 2nd polymerization tank was confirmed after completion | finish of superposition | polymerization, it was confirmed that polyphenylene ether has adhered in the tank. The thickness of the adhering polyphenylene ether was about 0.7 cm.

[Comparative Example 4]
Polyphenylene ether was polymerized according to Example 1 described in JP-A No. 64-33131.
Although polyphenylene ether was precipitated during the polymerization, the polymerization was continued as it was.
A 10% aqueous solution of ethylenediaminetetraacetic acid tripotassium salt (a reagent manufactured by Dojindo Laboratories) was added to the resulting polyphenylene ether slurry, and the mixture was warmed to 50 ° C.
Next, hydroquinone (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added little by little, and the temperature was kept at 50 ° C. until the slurry polyphenylene ether became white.
The slurry-like polyphenylene ether which became white was filtered, methanol was sprinkled on the remaining polyphenylene ether to perform washing treatment, and then vacuum dried at 140 ° C. and 1 mmHg for 1 hour to obtain a polyphenylene ether powder.
The obtained polyphenylene ether was evaluated for the above (1) to (11). The evaluation results are shown in Table 1 below.

[Comparative Example 5]
Polyphenylene ether was polymerized according to Example 1 described in JP-A-53-92898.
No precipitation of polyphenylene ether was observed during the polymerization.
The obtained polyphenylene ether was evaluated for the above (1) to (11). The evaluation results are shown in Table 1 below.

[Comparative Example 6]
In the process of producing the polyphenylene ether in Comparative Example 5, ethylenediaminetetraacetic acid trisodium salt was not used. The other conditions were the same as in Comparative Example 5 to polymerize polyphenylene ether.
No precipitation of polyphenylene ether was observed during the polymerization.
The obtained polyphenylene ether was evaluated for the above (1) to (11). The evaluation results are shown in Table 1 below.

[Comparative Example 7]
Polyphenylene ether was polymerized according to Example 1 described in JP-A No. 2003-261647.
Although polyphenylene ether was precipitated during the polymerization, the polymerization was continued as it was.
A 10% aqueous solution of ethylenediaminetetraacetic acid tripotassium salt (a reagent manufactured by Dojindo Laboratories) was added to the resulting polyphenylene ether slurry, and the mixture was warmed to 50 ° C.
Next, hydroquinone (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added little by little, and the temperature was kept at 50 ° C. until the slurry polyphenylene ether became white.
The slurry-like polyphenylene ether that has turned white is filtered, and the remaining polyphenylene ether is sprinkled with methanol, washed, then placed in a cut disk dryer and dried at 150 ° C. under a nitrogen atmosphere for 5 hours. A powder was obtained.
The obtained polyphenylene ether was evaluated for the above (1) to (11). The evaluation results are shown in Table 1 below.
Since the fluidity was very high and the strand could not be drawn, the molding fluidity (SSP) test of (7) was not performed.

  As shown in Table 1 above, in Examples 1 to 5, the molecular weight of 8000 or less and the molecular weight of 50,000 or more are less than 20% by mass and the residual metal is less than 2.0 ppm. It can be seen that the material is excellent in balance between molding fluidity and mechanical strength, and is of high quality. Good results were also obtained in the scattering and dust generation evaluation.

  In Examples 1 to 5, the evaluation of the color index (6) was also 0.3 or less, and it was found that polyphenylene ether having high purity was obtained.

  Furthermore, in Examples 1-5, the value represented by weight average molecular weight (Mw) / number average molecular weight (Mn) was also 2.8 or less, and it became polyphenylene ether excellent in fluidity and mechanical strength.

  In Comparative Example 1, the component having a molecular weight of 8000 or less is contained in an amount of 20% by mass or more, and the content of the low molecular component is extremely high. Therefore, a favorable result cannot be obtained in the above (11) folding resistance evaluation. The strength was insufficient. In addition, the fluidity could not be evaluated sufficiently well for practical use.

  In Comparative Example 2, since the amount of residual metal was extremely high at 10.0 ppm, practically good results were not obtained in the generation of eyes and the generation of gels.

In Comparative Example 3, since the amount of residual aromatic hydrocarbon was as large as 2.5% by mass, the occurrence of eye cracks became significant.
In Comparative Examples 2 and 3, the molding fluidity was not sufficient practically.

  In Comparative Examples 4 and 5, since the content of the high molecular weight component having a molecular weight of 50,000 or more exceeds 20% by mass and is extremely high, the molding fluidity is deteriorated, and the balance between the molding fluidity and the mechanical strength is deteriorated. did. Furthermore, the occurrence of gel and gel was confirmed.

  In Comparative Example 6, the content of the high molecular weight component having a molecular weight of 50,000 or more exceeds 20% by mass, and further, the amount of residual metal exceeds 2.0 ppm. did. Moreover, the molding fluidity was also deteriorated, and the balance between the molding fluidity and the mechanical strength was deteriorated.

  In Comparative Example 7, since the content of the low molecular weight component having a molecular weight of 8000 or less was extremely high, the mechanical strength was insufficient and the polyphenylene ether in which the generation of gel was confirmed was obtained.

  The polyphenylene ether of the present invention has an excellent balance between molding fluidity and mechanical strength, excellent powder handling properties, solvent solubility, and further, the occurrence of foreign matter such as eyes and gels during processing is reduced, There is industrial applicability as mechanical parts, automobile parts, electric / electronic parts, particularly electric / electronic parts such as printed boards and insulating sealants, films, sheets, injection-molded bodies, blow-molded bodies, IC trays and the like.

Claims (6)

In the molecular weight measured by gel permeation chromatography using standard polystyrene as a calibration curve, the polyphenylene ether component having a molecular weight of 8000 or less is less than 20% by mass, and the polyphenylene ether component having 50,000 or more is less than 20% by mass,
The value of weight average molecular weight (Mw) / number average molecular weight (Mn) is 2.8 or less,
Polyphenylene ether having a residual metal catalyst amount of 2.0 ppm or less. Polyphenylene ether according to claim 1, wherein the content is less than 1.5 wt% 0.01 wt% of Kaoru aromatic hydrocarbons. The polyphenylene ether according to claim 1 or 2, wherein the polyphenylene ether component having a molecular weight of 10,000 to 40,000 is 60% by mass or more. 20 minutes at 310 ° C., Oite after heating at a pressure of 10 MPa,
A polyphenylene ether component having a molecular weight of 8000 or less is less than 20% by mass;
The polyphenylene ether component having a molecular weight of 50,000 or more is less than 20% by mass,
The value of weight average molecular weight (Mw) / number average molecular weight (Mn) is 2.8 or less,
The polyphenylene ether according to any one of claims 1 to 3. The original viscosity changing the .eta.a, 20 minutes at 310 ° C., when the ItaB the reduced viscosity after heating at a pressure of 10 MPa, satisfying the relation 0.10 ≦ (ηB-ηA) /ηA≦0.30 , The polyphenylene ether according to any one of claims 1 to 4. The polyphenylene ether according to any one of claims 1 to 5, having a number average molecular weight of 9000 or more and 25000 or less.