JP2013256645A - Method for producing polyphenylene ether powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing the polyphenylene ether powder having proper pulverization rate and favorable transportability, with less solvent to be used and without causing troubles such as scale adherence.SOLUTION: A method for producing polyphenylene ether powders includes a precipitation step of adding a polymer solution obtained by polymerizing a phenol compound and a poor solvent into a precipitation tank and precipitating polyphenylene ether to generate a slurry. In the polymer solution to be added to the precipitation tank, X and Y satisfy the following formulas (I): 30<X≤48; and (II): 14.891×(X/100)-0.9804×(X/100)-0.4602≤Y≤18.032×(X/100)-1.1873×(X/100)-0.3463 (wherein X is the concentration [mass%] of polyphenylene ether in a good solvent solution; and Y is the mass ratio (poor solvent/good solvent) of the poor solvent fed in the precipitation tank in the precipitation step to the good solvent in the polymer solution).

Description

  The present invention relates to a method for producing polyphenylene ether powder.

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

As a method for producing polyphenylene ether, a method is known in which phenols are oxidatively polymerized in a good solvent of polyphenylene ether in the presence of a copper compound and amines.
As a method of precipitating polyphenylene ether from the polyphenylene ether solution obtained by this method, a method of precipitating polyphenylene ether particles by adding a poor solvent of polyphenylene ether such as methanol to a good solvent solution of polyphenylene ether is known. .

In the conventional polyphenylene ether production method described above, the amount of fine powder of the precipitated polyphenylene ether particles is not appropriate. Therefore, when the amount of fine powder is too small when packed in a bag or in a flexible container, the fine powder amount cannot be filled. If it is too high, the bulk specific gravity becomes high, and there is a problem that transportability is poor.
Moreover, the fine powder amount of the polyphenylene ether particles is optimal for fine packing because the particle size of the polyphenylene ether particles periodically varies in the precipitation process and further finely powdered in the post-treatment process after the precipitation process. It is difficult to adjust the amount.

  In Patent Document 1 described below, a technique for obtaining polyphenylene ether with a reciprocating stirrer that causes less fine powder scattering in the subsequent step of the precipitation step and less biting into the extruder is described.

  Patent Document 2 below describes a technique for precipitating particles having a uniform particle diameter using a draft tube type precipitation apparatus.

  Furthermore, in the following Patent Document 3, in order to suppress fine powder loss, filter clogging and poor bite of the extruder, a technique for regulating the stirring speed, polymer concentration, precipitation temperature, amount of poor solvent, etc. during precipitation has been proposed. Yes.

JP 2000-281773 A International Publication No. 2003/064499 US Patent Application Publication No. 2011/0160421

  However, in Patent Document 1, the stability during the precipitation process operation is insufficient, and the particle diameter periodically varies and fine powder is generated. Therefore, there is a concern that the particle diameter of the product obtained through the subsequent process may also vary. have. Therefore, development of a more stable precipitation process is desired.

  Further, Patent Document 2 is a deposition technique in a region where the polymer concentration is low, and has a problem that the amount of solvent used increases and is inefficient. In addition, the particles obtained by this technique have a problem that the fine powder ratio is too low and the particles are uniform, so that they are difficult to pack closely and have a low bulk specific gravity.

  Further, Patent Document 3 also includes precipitation in a region where the polymer concentration is low, which has a problem that the precipitation is unstable and inefficient.

As described above, in the conventional polyphenylene ether precipitation method and the post-treatment step after the precipitation step, the fine powder rate (fine powder amount) of the polyphenylene ether powder is not controlled to an appropriate value (range), and fine packing or From the viewpoint of bulk specific gravity, there is a problem that it is not practically desirable.
Furthermore, in the prior art, since the polymer is deposited in a region where the polymer concentration is low, there is a problem that the amount of solvent used is large and the recovery cost is also great.
As described above, the conventional deposition methods cannot sufficiently meet the demands of the industry.

  Therefore, in the present invention, in view of the above-described problems of the prior art, the amount of solvent used is small, and it is appropriately pulverized in a post-treatment step after the precipitation step, and a polyphenylene ether powder that can obtain a practically suitable fine powder rate, It is an object of the present invention to provide a method of stably producing without trouble such as scale adhesion.

As a result of intensive studies in order to solve the above-described problems of the prior art, the inventors have made the concentration of the polymer solution fed to the precipitation tank higher than that of the prior art and set the ratio of the poor solvent and the good solvent to a predetermined value. By keeping in this range, it was found that a powder having an appropriate fine powder ratio and a fine powder ratio can be obtained in the post-treatment process, and the present invention has been completed.
That is, the present invention is as follows.

[1]
A polymerization step of polymerizing a phenol compound in a good solvent of polyphenylene ether to obtain a polymer solution;
A precipitation step of adding a polymer solution of the phenolic compound and a poor solvent for polyphenylene ether to a precipitation tank, and depositing polyphenylene ether to form a slurry;
Have
In the polymer solution added to the precipitation tank, the concentration of polyphenylene ether in a good solvent solution is X [mass%],
When the mass ratio (poor solvent / good solvent [wt / wt]) between the poor solvent fed into the precipitation tank and the good solvent in the polymer solution in the precipitation step is Y, the X and Y are A method for producing a polyphenylene ether powder satisfying the following formulas (I) and (II).
30 <X ≦ 48 (I)
14.891 · (X / 100) ² −0.9804 · (X / 100) −0.4602 ≦ Y ≦ 18.032 · (X / 100) ² −1.1873 · (X / 100) -0. 3463 (II)
[2]
After the polymerization step, the polymer solution obtained by the polymerization step is heated to a boiling point or higher of the good solvent of the polyphenylene ether, and a concentration step for obtaining a polymer solution with adjusted polymer concentration is performed. Of manufacturing polyphenylene ether powder.
[3]
The polyphenylene according to the above [1] or [2], further comprising a step of mechanically crushing the wet polyphenylene ether after washing the slurry produced by precipitating the polyphenylene ether with a poor solvent and solid-liquid separation. A method for producing ether powder.
[4]
The method for producing a polyphenylene ether powder according to any one of [1] to [3], wherein the good solvent for the polyphenylene ether is at least one selected from the group consisting of benzene, toluene, and xylene.
[5]
The poor solvent of the polyphenylene ether is at least one selected from the group consisting of methanol, ethanol, isopropanol, n-butanol, acetone, methyl ethyl ketone, and water, according to any one of the above [1] to [4]. Production method of polyphenylene ether powder.
[6]
The method for producing a polyphenylene ether powder according to any one of [1] to [5], wherein the poor solvent of the polyphenylene ether contains 0.05 to 30% by mass of water in the poor solvent.
[7]
As the precipitation tank, a tank equipped with at least one stirrer blade selected from the group consisting of inclined paddle blades, screw blades, and ribbon blades is used, and stirring is performed with the stirring blades in the precipitation step. [6] The method for producing a polyphenylene ether powder according to any one of [6].
[8]
The method for producing a polyphenylene ether powder according to any one of [1] to [7], wherein the precipitation tank is provided with at least one baffle.
[9]
The precipitation tank includes a draft tube, and the draft tube includes at least one stirrer blade selected from the group consisting of the inclined paddle blade, screw blade, and ribbon blade, and the stirring blade inside the draft tube The method for producing a polyphenylene ether powder according to [7] or [8], wherein a lower discharge blade is used and stirring is performed by the stirring blade in the precipitation step.
[10]
As the precipitation tank, a stirring blade that is a ribbon blade is provided on the outside of the draft tube, and the stirring blade on the outside of the draft tube is an upper discharge blade, and stirring is performed with the stirring blade in the precipitation step. The method for producing a polyphenylene ether powder according to [9].
[11]
The method for producing a polyphenylene ether powder according to any one of [1] to [10], wherein the liquid temperature in the precipitation step is 30 to 63 ° C.
[12]
The method for producing a polyphenylene ether powder according to any one of [1] to [11], wherein the residence time of the polyphenylene ether in the precipitation tank is 0.25 to 5 minutes.

  According to the method for producing a polyphenylene ether powder of the present invention, polyphenylene ether particles having an appropriate fine powder ratio and good transportability can be stably deposited without using a small amount of solvent and without trouble such as scale adhesion. Can do.

  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.

[Method for producing polyphenylene ether powder]
The method for producing the polyphenylene ether powder of the present embodiment is as follows:
A polymerization step of polymerizing a phenol compound in a good solvent of polyphenylene ether to obtain a polymer solution;
A precipitation step of adding a polymer solution of the phenolic compound and a poor solvent for polyphenylene ether to a precipitation tank, and depositing polyphenylene ether to form a slurry;
Have
In the polymer solution added to the precipitation tank, the concentration of polyphenylene ether in a good solvent solution is X [mass%],
When the mass ratio (poor solvent / good solvent [wt / wt]) between the poor solvent fed into the precipitation tank and the good solvent in the polymer solution in the precipitation step is Y, the X and Y are This is a method for producing a polyphenylene ether powder that satisfies the following formulas (I) and (II).
30 <X ≦ 48 (I)
14.891 · (X / 100) ² −0.9804 · (X / 100) −0.4602 ≦ Y ≦ 18.032 · (X / 100) ² −1.1873 · (X / 100) -0. 3463 (II)
The “concentration of polyphenylene ether in a good solvent solution” means the concentration of the polymer solution obtained in the above-described polymerization step or concentration step, and the so-called good solvent in the initial charge is not included in the conversion of the concentration. Shall.
The “poor solvent fed to the precipitation tank in the precipitation step” refers to the poor solvent to be fed to precipitate the polyphenylene ether after the initial preparation of the precipitation tank is completed. It means that the poor solvent of the initial charge liquid is not included.
Furthermore, the “good solvent in the polymer solution” means a good solvent in the polymer solution obtained in the polymerization step described above, and does not include the good solvent in the initial charge solution.

(Polyphenylene ether)
The polyphenylene ether (hereinafter sometimes simply referred to as “PPE”) produced in the polymerization step in the method for producing the polyphenylene ether powder of the present embodiment will be described below.
In the polyphenylene ether powder production method of the present embodiment, the polyphenylene ether produced by the polymerization step is a homopolymer and / or copolymer having a repeating unit structure represented by the following formula (1).

... (1)

In said formula (1), R < ₁ >, R < ₂ >, R < ₃ > and R < ₄ > are respectively independently a hydrogen atom, a halogen atom, a C1-C7 alkyl group, a phenyl group, a haloalkyl group, an aminoalkyl group. , A hydrocarbonoxy group, and a halohydrocarbonoxy group in which at least two carbon atoms separate a halogen atom and an oxygen atom.

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” represented by R ₁ , R ₂ , R ₃ , and R ₄ is preferably linear or branched having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. A chain alkyl group is assumed and is not particularly limited, and examples thereof include 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), the alkyl group represented by R ₁ , R ₂ , R ₃ , and R ₄ may be substituted with one or more substituents at substitutable positions.
Such a substituent is not particularly limited, and examples thereof 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 group (eg, phenyl, naphthyl), alkenyl group (eg, ethenyl, 1-propenyl, 2-propenyl), alkynyl group (eg, ethynyl, 1 -Propynyl, 2-propynyl), an aralkyl group (for example, benzyl, phenethyl), an alkoxy group (for example, methoxy, ethoxy) and the like.

The reduced viscosity measured at 30 ° C. using a chloroform solution prepared by dissolving 0.5 g of the polyphenylene ether in 1 dL of chloroform is preferably in the range of 0.15 to 1.0 dL / g, more preferably It is in the range of 20 to 0.85 dL / g, more preferably in the range of 0.25 to 0.70 dL / g.
Sufficient mechanical properties can be exhibited when the reduced viscosity is 0.15 dL / g or more.
Further, 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 the peripheral equipment of the polymerization tank can be appropriately controlled, post-processing is easy, and workability is improved. Will also be good.
The reduced viscosity can be measured by the method described in Examples described later.

Information on the molecular weight of the polyphenylene ether can be obtained by measurement using a GPC (gel permeation chromatography) measuring device.
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). The UV wavelength of the detector can be selected from 254 nm for standard polystyrene and 283 nm for polyphenylene ether.

  Further, 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.
From the viewpoint of exhibiting mechanical properties, the lower limit of the number average molecular weight is preferably 7,000 or more, and from the viewpoint of liquid viscosity during the polymerization reaction, the upper limit of the number average molecular weight is preferably 35,000 or less. .

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 low molecular weight component and the high molecular weight component are well balanced, and polyphenylene ether having such a degree of dispersion is excellent in the balance between chemical resistance and fluidity.

The polyphenylene ether preferably has a residual metal catalyst amount of less than 1.0 ppm.
The residual metal catalyst amount is an indicator of the purity of the polyphenylene ether itself.
It is preferable from the viewpoint of the high purity of polyphenylene ether that the residual metal catalyst amount is less than 1.0 ppm, and further, since the residual metal catalyst amount is less than 1.0 ppm, it is preferable because the yellowness after heat history can be suppressed, More preferably less than 0.8 ppm, even more preferably less than 0.6 ppm, even more preferably less than 0.4 ppm, and even more preferably less than 0.2 ppm.
The residual metal catalyst amount of polyphenylene ether can be measured with an atomic absorption photometer.

(Polyphenylene ether polymerization process)
<Monomer used in polymerization step>
The polyphenylene ether represented by the above formula (1) can be produced by polymerizing the following phenol compounds.
Although it does not specifically limit as a 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-propylphenol, 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-phenyl Phenol, 2,6-diphenylphenol, 2,6-bis- (4-fluorophenyl) Enol, 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, , 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-trimethyl Examples thereof include a method using a combination of phenol and 2,5-dimethylphenol, a method using a combination of 2,6-dimethylphenol and 2,3,6-trimethylphenol, and the like. The mixing ratio can be arbitrarily selected.
In addition, the phenol compounds used include a small amount of m-cresol, p-cresol, 2,4-dimethylphenol, 2,4,6-trimethylphenol, etc., which are contained as by-products during production. It may be.

In addition to the phenol compound, a divalent phenol compound represented by the following formula (2) may be contained.
The divalent phenolic compound represented by the following formula (2) is a reaction between a corresponding monovalent phenol compound and a ketone or a dihalogenated aliphatic hydrocarbon, or between corresponding monovalent phenol compounds. It can be advantageously produced industrially by the above reaction.
Although it is not particularly limited, for example, a compound group obtained by a reaction of a general-purpose ketone compound such as formaldehyde, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, cyclohexane and a monovalent phenol compound, or a reaction between monovalent phenol compounds. There are compound groups obtained.
Although it does not specifically limit as a bivalent phenolic compound represented by following formula (2), For example, the compound represented by the following general formula (2-a), (2-b), (2-c) Is mentioned.

... (2-a)

... (2-c)

A typical compound represented by the above formula (2) is not particularly limited. For example, R ₅ and R ₆ are methyl groups, R ₇ and R ₈ are hydrogen, and X is an aryl group of both. Compounds wherein R ₅ and R ₆ are methyl groups, R ₇ and R ₈ are hydrogen and X is methylene, R ₅ and R ₆ are methyl groups, R ₇ and R ₈ are hydrogen and X is thio R ₅ , R ₆ and R ₇ are methyl groups, R ₈ is hydrogen and X is ethylene, R ₅ and R ₆ are methyl groups, R ₇ and R ₈ are hydrogen and X is isopropylidene, A compound wherein R ₅ and R ₆ are methyl groups, R ₇ and R ₈ are hydrogen and X is cyclohexylidene, R ₅ , R ₆ and R ₇ are methyl groups, R ₈ is hydrogen and X is both aryl groups compounds _directly, R 5, _{R 6} and _{R 7} is a methyl group, _{R 8} is Compound X in iodine is _methylene, R 5, _{R 6} and _{R 7} is a methyl group, compounds X _{R 8} is hydrogen is _ethylene, R 5, _{R 6} and _{R 7} is a methyl group, _{R 8} is hydrogen A compound in which X is thio, R ₅ , R ₆ and R ₇ are methyl groups, R ₈ is hydrogen and X is isopropylidene, R ₅ , R ₆ , R ₇ and R ₈ are methyl groups and X is methylene A compound in which R ₅ , R ₆ , R ₇ and R ₈ are methyl groups and X is ethylene, a compound in which R ₅ , R ₆ , R ₇ and R ₈ are methyl groups and X is isopropylidene, etc. However, it is not limited to these examples.

In the polymerization process of polyphenylene ether, in addition to the above-described phenol compound, it is possible to coexist a polyhydric phenol compound.
Although it does not specifically limit as a polyhydric phenol compound, For example, it has 3 or more and less than 9 phenolic hydroxyl groups in a molecule | numerator, and an alkyl group or alkylene in the 2nd, 6th position of at least 1 phenolic hydroxyl group in it And compounds having a group.
Specific examples of the polyhydric phenol compound are listed below.
Although not particularly limited, for example, 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) methylene] bis (2,6-dimethylphenol), 4 , 4 ′-[(3,4-dihydroxyphenyl) methylene] bis (2,3,6-trimethylphenol), 2,2 ′-[(4-hydroxyphenyl) methylene] bis (3,5,6-trimethyl) Phenol), 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] phenyl] ethylidene] bis (2,6-dimethylphenol), 2, -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-cyclohexylphenol, 2,4-bis [(2-hydroxy-5- Tilphenyl) 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 / 3,6-dimethylphenyl) methyl] -4-methylphenol], , 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-methylphenyl) methyl] -3,6-dimethylphenol], 4,4′-me Renbis [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′-cyclohex Silidenebis [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- Rehydroxyphenyl) methyl] phenol], 4,4 ', 4 ", 4"'-(1,2-ethanediylidene) tetrakis (2,6-dimethylphenol), 4,4 ', 4 ", 4"'- Examples include (1,4-phenylenedimethylidene) tetrakis (2,6-dimethylphenol), but are not limited thereto.
The number of phenolic hydroxyl groups is not particularly limited as long as it is 3 or more. However, when the number increases, it becomes difficult to control polymerization. The alkyl group or alkylene group at the 2-6 position is preferably a methyl group. The most 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).

<Polymerization method>
In the method for producing a polyphenylene ether powder of the present embodiment, first, the above-described phenol compound is polymerized by solution polymerization to obtain a polymer solution containing polyphenylene ether (polymerization step).
In addition, you may heat the polymer solution obtained at the superposition | polymerization process above the boiling point of the said good solvent, adjust a polymer concentration, and may obtain the concentrated polymer solution (concentration process). The concentration step is performed as necessary.
Next, as will be described later, the polymer solution and a poor solvent for polyphenylene ether are mixed to precipitate polyphenylene ether to produce a slurry (precipitation step).
Solution polymerization is a polymerization method in which polymerization is carried out in a good solvent of polyphenylene ether and precipitation of polyphenylene ether does not occur during the polymerization. All polyphenylene ether molecules are in a dissolved state, and the molecular weight distribution tends to be wide. The polymer solution in which polyphenylene ether is dissolved is concentrated by a concentration step as necessary, and the polymer solution is mixed with a poor solvent of polyphenylene ether such as methanol to obtain powdery polyphenylene ether.

<Good solvent used for polymerization>
As a good solvent for polyphenylene ether used in the polymerization, at least one selected from the group consisting of benzene, toluene, and xylene is preferable.

  As an example of the polymerization method of polyphenylene ether, there is a method of oxidative polymerization of 2,6-xylenol 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 concentration is 10% by mass or more, the production efficiency of polyphenylene ether increases.
On the other hand, when the concentration exceeds 30% by mass, it tends to be impossible to adjust to a specific molecular weight. The present inventors presume this cause as follows. If the concentration exceeds 30% by mass, the liquid viscosity at the end of the polymerization becomes high, and uniform stirring becomes difficult. Therefore, a heterogeneous reaction occurs, and an unexpected molecular weight polyphenylene ether may be obtained. As a result, as described above, it may be difficult to efficiently produce polyphenylene ether having a number average molecular weight of 7000 to 35,000.

The solution polymerization process of polyphenylene ether is 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 Those mixed with can be used.

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

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.

A known catalyst system generally used for the production of polyphenylene ether may be added to the polymerization reaction system of polyphenylene ether.
For example, a transition metal ion having oxidation-reduction ability and an amine compound capable of complexing with this metal ion can be mentioned. Specifically, a catalyst system comprising a copper compound and an amine, and a manganese compound and an amine. And a catalyst system composed of a cobalt compound and an amine.

Since the polymerization reaction of polyphenylene ether proceeds efficiently under some alkaline conditions, some alkali or further amine may be added thereto.
As a suitable catalyst in the polymerization process of polyphenylene ether, a catalyst containing a copper compound, a halogen compound and a diamine compound represented by the following formula (3) as constituent components can be mentioned.

... (3)

In said formula (3), R < ₉ >, R < ₁₀ >, R < ₁₁ > and R <_12> are each independently selected from the group which consists of a hydrogen atom and a C1-C6 linear or branched alkyl group. Indicates either.
Note that all are not hydrogen at the same time.
R ₁₃ 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 the said Formula (3), For example, N, N, N ', N'-tetramethylethylenediamine, N, N, N'-trimethylethylenediamine, N, N'-dimethyl Ethylenediamine, N, N-dimethylethylenediamine, N-methylethylenediamine, N, N, N ′, N′-tetraethylethylenediamine, N, N, N′-triethylethylenediamine, N, N′-diethylethylenediamine, N, N-diethyl Ethylenediamine, N-ethylethylenediamine, N, N-dimethyl-N'-ethylethylenediamine, N, N'-dimethyl-N-ethylethylenediamine, Nn-propylethylenediamine, N, N'-di-propylethylenediamine, N -I-propylethylenediamine, , N′-di i-propylethylenediamine, Nn-butylethylenediamine, N, N′-di-n-butylethylenediamine, Ni-butylethylenediamine, N, N′-di-i-butylethylenediamine, Nt -Butylethylenediamine, N, N'-di-t-butylethylenediamine, N, N, N ', N'-tetramethyl-1,3-diaminopropane, N, N, N'-trimethyl-1,3-diamino Propane, 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.

Preferred diamine compounds are those in which the alkylene group (R ₁₃ ) connecting two nitrogen atoms has 2 or 3 carbon atoms in the formula (3).
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.

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.
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). These copper compounds may be used alone or in combination of two or more.

Examples of the halogen compound constituting the catalyst component include hydrogen chloride, hydrogen bromide, hydrogen iodide, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, 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.
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 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 at a copper atom. It is preferable that 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 the phenol compound used.

As the polymerization catalyst, in addition to the above-described compounds, for example, a tertiary monoamine compound or a secondary monoamine compound may be contained alone or in combination.
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 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 the phenol compound to be polymerized.
The tertiary monoamine compound does not need to be added to the reaction system from the beginning in the whole amount normally used. That is, some of them may be added in the middle, or some of them may be added sequentially from the start of polymerization. Moreover, you may add to the solution of a phenolic compound or a phenolic compound simultaneously with the start of superposition | polymerization, and may add with this.
Secondary monoamine compounds include secondary aliphatic amines.
Examples of secondary aliphatic amines include dimethylamine, diethylamine, di-n-propylamine, di-i-propylamine, di-n-butylamine, di-i-butylamine, di-t-butylamine, and 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.

(Post-treatment after polymerization reaction 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, there is a method of deactivating the catalyst.
Since the polymerization solution at the end of the polymerization is in a state where polyphenylene ether is dissolved in a good solvent, for the purpose of washing and removing the catalyst, the solubility of polyphenylene ether is low, and phase separation from the good solvent of polyphenylene ether, such as water, etc. It is preferable to repeatedly perform the washing treatment using a solution containing the above solvent as a main component.

(Concentration process)
The polymer solution containing the polyphenylene ether obtained in the above-described polymerization step is heated to the boiling point of the good solvent or higher if necessary, and the good solvent is extracted out of the system to concentrate, and the polymer concentration X described later is set. The polymer concentration may be increased by adjusting to a desired range.
That is, the polyphenylene ether concentration (X [mass%]) in the good solvent solution of polyphenylene ether is adjusted to a range of more than 30 mass% and 48 mass% or less.
X is more preferably 44% by mass or less, and still more preferably 40% by mass or less.

(Polyphenylene ether precipitation process)
In the polyphenylene ether precipitation step, first, the initial charge liquid in the precipitation tank is such that the mass ratio of the poor solvent to the good solvent (initial charge poor solvent / initial charge good solvent) is in the range of 0.4 to 1.2. It is preferable to charge in.
By adding the polymer solution obtained through the polymerization step or the concentration step and the poor solvent to the precipitation tank and stirring the composition, the composition in the precipitation tank is stabilized within the range satisfying the formula (II). To form a slurry.
In the present embodiment, in the precipitation step, the polyphenylene ether-containing polymer solution concentration (X) charged into the precipitation tank is less than 30% by weight and 48% by weight or less, and the poor solvent fed to the precipitation tank The mass ratio to the good solvent (poor solvent / good solvent) = Y in the polymer solution charged into the precipitation tank satisfies the condition shown in the formula (II).
14.891 · (X / 100) ² −0.9804 · (X / 100) −0.4602 ≦ Y ≦ 18.032 · (X / 100) ² −1.1873 · (X / 100) -0. 3463 (II)
The “polyphenylene ether-containing polymer solution concentration (X) to be introduced into the precipitation tank in the precipitation step” means the concentration of the polymer in the good solvent solution in the polymer solution obtained in the polymerization step or concentration step described above. And the good solvent of the initial charge liquid is not included.
The “poor solvent to be fed to the precipitation tank” means a poor solvent to be fed in order to deposit the polymer solution after the initial preparation of the precipitation tank and then deposit polyphenylene ether. The poor solvent of the initial charge liquid is not included.
Further, the “good solvent in the polymer solution charged into the precipitation tank” means a good solvent contained in the polymer solution charged into the precipitation tank after the initial charge of the precipitation tank is completed. The good solvent is not included.
That is, in this specification, Y = (poor solvent fed in the precipitation step / good solvent contained in the polymer solution).
When the mass ratio of the poor solvent fed to the precipitation tank and the good solvent in the polymer solution (poor solvent / good solvent) = Y satisfies the above formula (II), the slurry containing the precipitated particles is solid-liquid separated and dried. After a post-treatment step such as this, since it contains moderate fine powder, fine packing is possible, and polyphenylene ether powder with excellent transportability is produced.
When the mass ratio of the poor solvent to the good solvent (poor solvent / good solvent) = Y is in the range shown in the above formula (II), the scale of the deposited particles to the reactor is extremely small, and the polymer is stably produced. Generate.
The scale refers to a state in which the precipitated polymer adheres to the side surface of the reactor, the stirring blade, or the like, whereby the concentration of the raw material (polymer) in the system is not constant. Moreover, the problem that a loss polymer increases arises.
In the present embodiment, the ratio of the poor solvent and the good solvent is controlled within the range of the above formula (II) from the viewpoint of stably producing polyphenylene ether particles having a desired fine powder ratio in the precipitation step.
In this embodiment, in the precipitation step, a polymer solution having a polyphenylene ether concentration in the good solvent of more than 30% by mass and 48% by mass or less is used, but the polyphenylene ether concentration in the good solvent solution of polyphenylene ether is 30% by mass. If it is below, the amount of the poor solvent for precipitating the polyphenylene ether becomes large, which is not preferable in terms of production efficiency. Further, when the poor solvent is recovered and used, it is not preferable because the recovery cost becomes great.
On the other hand, when the polyphenylene ether concentration in the good solvent of polyphenylene ether exceeds 48% by mass, the liquid viscosity becomes high and the equipment cost of peripheral equipment such as a pump becomes large, which is not preferable. Furthermore, if the temperature is not kept high, the polymer is solidified and operation becomes difficult, which is not preferable.

<Poor solvent>
As the poor solvent used in the precipitation step in the method for producing the polyphenylene ether powder of the present embodiment, the following solvents can be used.
The poor solvent is a solvent that does not dissolve polyphenylene ether at all or slightly dissolves it.
Specifically, ketones and alcohols can be used. Preferably, it is a C1-C10 alcohol. For example, methanol, ethanol, propanol, isopropanol, n-butanol, pentanol, hexanol, ethylene glycol, acetone, methyl ethyl ketone and the like can be mentioned.
These poor solvents may be used alone or in combination of two or more.
More preferred poor solvents are methanol, ethanol, isopropanol, n-butanol, 2-butanol, acetone, methyl ethyl ketone, and water.
Among the poor solvents, a combination of water and other poor solvents is preferable, and the water content at this time is preferably 0.05 to 30% by mass, more preferably from the viewpoint of uniform precipitation particle size and scale prevention. Is 0.5 to 10% by mass.

In the method for producing the polyphenylene ether powder of the present embodiment, as described above, the mass ratio (poor solvent / good solvent) between the poor solvent fed when the polyphenylene ether is precipitated and the good solvent in the polymer solution is defined as Y. Then, Y is within the range represented by the following formula using polymer concentration: X [mass%] in a good solvent solution of polyphenylene ether.
30 <X ≦ 48 (I)
14.891 · (X / 100) ² −0.9804 · (X / 100) −0.4602 ≦ Y ≦ 18.032 · (X / 100) ² −1.1873 · (X / 100) -0. 3463 (II)
By adjusting the ratio of the polymer solution fed to the precipitation tank and the poor solvent, Y can be controlled to fall within the range of (II) above.
When Y is within the range of the above formula (II), the particle size is moderately changed in the precipitation tank, and the polyphenylene ether particles that are easily densely packed can be precipitated. Further, when the ratio of poor solvent / good solvent is in the range of the above formula (II), the scaling in the precipitation tank is extremely small and stable operation is possible.
The fine powder ratio (content ratio of particles of 105 μm or less) of the polyphenylene ether powder obtained by the method for producing the polyphenylene ether powder of the present embodiment is 9 to 40 masses from the viewpoint of being capable of fine packing and improving the transportability. % Is preferable, and more preferably 9 to 16% by mass.
The above formula (II) is the polymer concentration in the precipitation tank ([(polymer mass present in the precipitation tank) / (total mass of good solvent + poor solvent present in the precipitation tank after feeding)] × 100 ) Is 18 to 21% by mass. At this concentration, the polyphenylene ether particles can be made to uniformly flow in the slurry liquid without settling.
Further, if the mass ratio of the poor solvent to the good solvent (poor solvent / good solvent) when precipitating the polyphenylene ether is in the range of the formula (II), the agglomeration and / or adhesion of the particles in the precipitation tank Is an appropriate range. As a result, scale adhesion can be suppressed while controlling to a desired particle size distribution.
That is, by satisfying the above formula (II), the poor solvent becomes rich, and the good solvent becomes difficult to impregnate into the polyphenylene ether particles, and as a result, the fine particles increase to agglomerate appropriately and the residual solvent amount is small. And troubles such as scale adhesion can be effectively prevented. Further, when the amount of good solvent impregnated is small, the polyphenylene ether itself becomes strong, and high-quality polyphenylene ether particles are obtained in which the change in particle size is extremely small even in the post-treatment step after the precipitation step.
Furthermore, by being rich in a poor solvent and appropriately containing fine powder, it is possible to more reliably obtain the effects that the drying property is improved and the residual solvent is small.

  The liquid temperature in the precipitation step is preferably 30 to 63 ° C. from the viewpoint of precipitation particle size stability and scale prevention. More preferably, it is 40-60 degreeC.

  The residence time of the polyphenylene ether in the precipitation tank is preferably 0.25 to 5 minutes from the viewpoint of the stability of the precipitated particle size. More preferably, it is 0.5 to 3.0 minutes.

The shape of the precipitation tank is preferably one having at least one stirrer blade selected from inclined paddle blades, screw blades, and ribbon blades. In the precipitation step described above, it is preferable to perform stirring with these stirring blades. Moreover, it is preferable that a stirring blade is a downward discharge.
Further, from the viewpoint of stabilizing the fluidity, it is preferable to use one provided with at least one baffle.

  The precipitation tank is preferably provided with a draft tube from the viewpoint of stabilizing the fluidity. In this case, the inside of the draft tube has an inclined paddle blade, a screw blade, and a ribbon blade from the viewpoint of stabilizing the precipitated particle size and preventing scale. It is preferable that at least one stirrer blade selected from the group consisting of the above is provided, and the stirrer blade inside the draft tube is preferably a lower discharge blade. In the precipitation step described above, it is preferable to perform stirring using the stirring tank which is the lower discharge blade. Thereby, the inside of a draft tube can be circulated as a downward flow, and the outside of a draft tube can be circulated as an upward flow, and the stirring operation state is stabilized.

  In addition, as a precipitation tank used in the precipitation step, the outside of the draft tube is preferably used with a stirring blade that is a ribbon blade from the viewpoint of stabilizing fluidity. A certain stirring blade is preferably an upper discharge blade from the viewpoint of combination with the lower discharge blade in the draft tube, and in the precipitation step described above, stirring is preferably performed by the stirring blade that is the upper discharge blade.

(Washing process)
You may perform the washing | cleaning process which adds a poor solvent to the slurry obtained in the precipitation process mentioned above, stirs, and wash | cleans 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 crushed 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.
In the precipitation step described above, the mass ratio (Y) between the poor solvent and the good solvent when the polyphenylene ether is precipitated is within the range of the above formula (II), so that particle aggregation and pulverization occur appropriately. A powder containing moderately fine particles can be obtained. The solid-liquid separator uses a centrifugal force or reduced pressure to drain the liquid, but the polyphenylene ether particles may become a soft mass at that time, so by crushing this to the size of the precipitated particles, The uniformity of the particle size can be improved.

(Drying process)
After performing a precipitation process, a washing process, and pulverization as necessary as described above, a drying process is performed.
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 the good solvent in the polyphenylene ether powder can be efficiently suppressed.
In addition, it is preferable that a residual solvent amount is less than 1.5 mass% from a viewpoint of the working environment at the time of a process, More preferably, it is 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.

(Characteristics of polyphenylene ether powder)
<Fine powder ratio>
As described above, the desired polyphenylene ether powder is obtained through the drying step, and the fine powder ratio (content of particles of 105 μm or less) in the polyphenylene ether powder after the drying step is 9% by mass or more and 40% by mass. % Is preferably 9% by mass or more and 24% by mass or less, and more preferably 9% by mass or more and 16% by mass or less.
When the fine powder ratio is 9% by mass or more, since the powder can be finely packed, an effect of improving transportability can be obtained.
When the fine powder ratio is 40% by mass or less, fine packing is possible when bagging or flexible container packing is performed, and a polyphenylene ether powder having good transportability can be obtained. Furthermore, it is possible to prevent scattering of fine powder and the like, and an effect of improving the handleability can be obtained.
In addition, a fine powder rate can be measured by the method as described in the Example mentioned later.
<Average particle size>
The average particle size of the polyphenylene ether powder obtained by the production method of the present embodiment is preferably 500 to 2000 μm from the viewpoint of powder handling property and transportability.
In addition, an average particle diameter can be measured by the method as described in the Example mentioned later.
<Reduced viscosity>
The polyphenylene ether powder obtained by the production method of the present embodiment preferably has a reduced viscosity measured at 30 ° C. using a chloroform solution in the range of 0.15 to 1.0 dL / g, more preferably 0. The range is from 20 to 0.85 dL / g, more preferably from 0.25 to 0.70 dL / g.
Sufficient mechanical properties can be exhibited when the reduced viscosity is 0.15 dL / g or more.
Further, 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 the peripheral equipment of the polymerization tank can be appropriately controlled, post-processing is easy, and workability is improved. Will also be good.
The reduced viscosity can be measured by the method described in Examples described later.
<Loose apparent specific gravity, apparent apparent specific gravity>
The polyphenylene ether powder obtained by the production method of the present embodiment preferably has a loose apparent specific gravity of 0.4 or more, more preferably 0.45 or more, and further preferably 0.48 or more. preferable. The upper limit of the loose apparent specific gravity is not particularly limited.
The polyphenylene ether powder obtained by the production method of the present embodiment preferably has an apparent specific gravity of 0.49 or more, more preferably 0.55 or more, and preferably 0.6 or more. More preferably, it is still more preferably 0.65 or more. Therefore, the upper limit of the apparent specific gravity is not particularly limited, but is preferably 1.06 or less.
By setting the loose apparent specific gravity or the apparent specific gravity within the above range, the transport efficiency when the polyphenylene ether powder is packed and transported in the container and the meterability when the polyphenylene ether powder is handled are excellent.
According to the manufacturing method of the present embodiment, within the range satisfying the above formulas (I) and (II), polyphenylene ether powder containing moderately fine powder can be precipitated, and as a result, the powder can be closely packed. This makes it possible to obtain a polyphenylene ether powder having good transportability.
Note that the loose apparent specific gravity or the apparent specific gravity can be measured by the method described in the examples below.

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 average particle size, calculation of fine powder ratio)
The obtained polyphenylene ether particles were sieved and the weight of each fractionated portion was measured.
From the cumulative curve of the particle size distribution, the particle size (median diameter) corresponding to the median cumulative value was defined as the average particle size.
Similarly, the content rate (% by mass) of particles of 105 μm or less obtained from the cumulative curve of particle size distribution was measured as the fine powder rate.

((2) Measurement of reduced viscosity)
A 0.5 g / dL chloroform solution was prepared, and the reduced viscosity (ηsp / c) [dL / g] at 30 ° C. was determined using an Ubbelohde viscosity tube.

((3) Measurement of molecular weight, calculation of molecular weight distribution (dispersion degree))
Using a gel permeation chromatography system 21 manufactured by Showa Denko Co., Ltd. as a measuring device, a calibration curve is created with standard polystyrene, and the weight average molecular weight (Mw) and number average molecular weight (Mn) are measured using this calibration curve. Went. Moreover, molecular weight distribution Mw / Mn (dispersion degree) was computed from these.
The molecular weight of standard polystyrene used was 3650000, 217000, 1090000, 681000, 204000, 52000, 30200, 13800, 3360, 1300, 550.
As the column, a column in which two K-805L manufactured by Showa Denko KK were connected in series was used.
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.

((4) Measurement of loose specific gravity or apparent specific gravity)
Measurement was performed using a metal container having a volume of 100 cc with a powder tester (manufactured by Hosokawa Micron Corporation: Powder Tester TYPE PT-E).
When the difference between the loose specific gravity and the apparent specific gravity is large, it is judged that it is advantageous from the viewpoint of transportability when packaging with fine packing.

((5) Comparison of solvent usage)
The amount of the good solvent and the poor solvent (kg) used for precipitating 1 kg of polyphenylene ether and the total amount thereof (including the amount of solvent used for washing after filtration) are calculated from the feed amount. A comparison was made.

[Production of polyphenylene ether solution]
<Production 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. While blowing nitrogen gas at a flow rate, 4.57 g of cupric oxide, 24.18 g of 47 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 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. 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 a toluene solution containing 13.1% by mass of polyphenylene ether, and this was used as a polymer solution (1).

<Production Example 2>
The molecular weight was controlled by changing the polymerization time by setting the aeration time of dry air to 125 minutes. Other conditions were produced in the same manner as in Production Example 1 to obtain a polymer solution. The resulting polymer solution was designated as polymer solution (2).

<Production Example 3>
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. While blowing nitrogen gas at a flow rate, 4.02 g of cupric oxide, 29.876 g of 47 mass% hydrogen bromide aqueous solution, 9.684 g of di-t-butylethylenediamine, 46.88 g of di-nbutylamine, 122 .28 g of butyldimethylamine, 17.53 kg of toluene, and 1.5 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, while introducing dry air from the sparger at a rate of 32.8 NL / min into the polymerization tank, 1.62 kg of 2,6-dimethylphenol and 3.12 kg of toluene were added from the plunger pump. Added to the polymerization tank over 30 minutes.
The polymerization solution at the end of the polymerization was in the form of a solution. The molecular weight was controlled by venting dry air for 86 minutes and changing the polymerization time. During the polymerization, the internal temperature was controlled to 40 ° C.
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 a toluene solution containing 13.1% by mass of polyphenylene ether, and this was used as a polymer solution (3).

[Precipitation of polyphenylene ether]
<Example 1>
The polymer solution (1) obtained in Production Example 1 was placed in a jacketed stirring tank, and heated by flowing a 120 ° C. heating medium 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. This operation was repeated to prepare 90 kg of a polymer solution having a polymer concentration of 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 raft tube.
During the operation of the precipitation tank, the amount of liquid in the precipitation tank 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.
300 g / min of methanol containing 3.0% by mass of water and 472 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 operation was continued for about 190 minutes.
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 at a rate of 200 g / min from a separate line, and the toluene in the polyphenylene ether particles was washed by substitution by stirring with the slurry liquid.
A cleaning slurry solution 147 kg having a slurry concentration of 14.8% by mass was prepared.
The slurry was divided every 10 kg and filtered through a basket centle (Tanabe Wiltech model 0-15). 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.
Next, the wet polyphenylene ether was put into a feather mill (FM-1S manufactured by Hosokawa Micron Co., Ltd.) set with a 10 mm round hole mesh, pulverized, and held at 150 ° C. and 1 mmHg for 1.5 hours, and dried polyphenylene ether. A powder was obtained.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 1.

<Example 2>
The polymer solution (1) obtained in Production Example 1 was concentrated to 38.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was adjusted to 400 g / min, the above 38.0% by mass polymer solution was fed at 372 g / min, and The poor solvent fed to the washing tank was carried out in the same manner as in Example 1 except that methanol was changed to 150 g / min to obtain a polyphenylene ether powder.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 1.

<Example 3>
The polymer solution (2) obtained in Production Example 2 was concentrated to 30.5% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 90 kg of a polymer solution having a polymer concentration of 30.5% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was adjusted to 300 g / min, and 472 g / min of the above 30.5% by mass polymer solution was fed into the tank. Except for this, the same procedure as in Example 1 was carried out to obtain a polyphenylene ether powder.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 1.

<Example 4>
The polymer solution (2) obtained in Production Example 2 was concentrated to 38.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was adjusted to 400 g / min, the above 38.0% by mass polymer solution was fed at 372 g / min, and The poor solvent fed to the washing tank was carried out in the same manner as in Example 1 except that methanol was changed to 150 g / min to obtain a polyphenylene ether powder.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 1.

<Example 5>
The polymer solution (3) obtained in Production Example 3 was concentrated to 30.5% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 90 kg of a polymer solution having a polymer concentration of 30.5% by mass.
The poor solvent fed to the precipitation tank and the polymer solution were the same as in the above examples except that 300 g / min of methanol containing 3.0% by mass of water and 472 g / min of the above 30.5% by mass polymer solution were fed. 1 was carried out to obtain a polyphenylene ether powder.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 1.

<Example 6>
The polymer solution (3) obtained in Production Example 3 was concentrated to 38.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 400 g / min, and 372 g / min of the above 38.0% by mass polymer solution was fed into the tank. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was set to 150 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 1.

<Comparative Example 1>
The polymer solution (1) obtained in Production Example 1 was placed in a jacketed stirring tank, and heated by flowing a 120 ° C. heating medium through the jacket.
Steam generated from toluene as a main component was cooled by a condenser, and toluene was extracted out of the system, and concentrated until the polymer concentration in the stirring tank reached 22.0% by mass. This operation was repeated to produce 125 kg of a polymer solution having a polymer concentration of 22.0% 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.
During the operation of the precipitation tank, the amount of liquid in the precipitation tank 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.
240 g / min of methanol containing 3.0% by mass of water and 532 g / min of the above 22.0% by mass polymer solution were fed into the precipitation tank. The paddle blade continued to rotate at 1500 rpm. The operation was continued for about 230 minutes.
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.
In order to stabilize the operation, methanol was fed from a separate line at 350 g / min and stirred with the slurry liquid to replace and wash the toluene in the polyphenylene ether particles.
180 kg of a washing slurry liquid having a slurry concentration of 15% by mass was prepared.
The slurry was divided every 10 kg and filtered through a basket centle (Tanabe Wiltech model 0-15). After each filtration, in order to stabilize the operation, 1.5 kg of methanol was sprayed onto the wet polyphenylene ether in the basket centre and filtered again to obtain wet polyphenylene ether.
Next, the wet polyphenylene ether was put into a feather mill (FM-1S manufactured by Hosokawa Micron Co., Ltd.) set with a 10 mm round hole mesh, pulverized, held at 150 ° C. and 1 mmHg for 1.5 hours, and dried polyphenylene ether powder. Got.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 2.

<Comparative example 2>
The polymer solution (1) obtained in Production Example 1 was concentrated to 38.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was 420 g / min, the above 38.0% by mass polymer solution was fed at 352 g / min, and The poor solvent fed to the washing tank was carried out in the same manner as in Example 1 except that methanol was changed to 500 g / min to obtain a polyphenylene ether powder.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 2.

<Comparative Example 3>
The polymer solution (2) obtained in Production Example 2 was concentrated to 22.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to produce 125 kg of a polymer solution having a polymer concentration of 22.0% by mass.
As the poor solvent and polymer solution fed to the precipitation tank, methanol containing 3.0% by mass of water was fed at 240 g / min, and the above 22.0% by mass polymer solution was fed at 532 g / min. The paddle blade continued to rotate at 1500 rpm. The operation was continued for about 230 minutes.
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.
In order to stabilize the operation, methanol was fed from a separate line at 350 g / min and stirred with the slurry liquid to replace and wash the toluene in the polyphenylene ether particles. 180 kg of a washing slurry liquid having a slurry concentration of 15% by mass was prepared.
The slurry was divided every 10 kg and filtered through a basket centle (Tanabe Wiltech model 0-15). After each filtration, in order to stabilize the operation, 1.5 kg of methanol was sprayed onto the wet polyphenylene ether in the basket centre and filtered again to obtain wet polyphenylene ether.
Next, the wet polyphenylene ether was put into a feather mill (FM-1S manufactured by Hosokawa Micron Co., Ltd.) set with a 10 mm round hole mesh, pulverized, held at 150 ° C. and 1 mmHg for 1.5 hours, and dried polyphenylene ether powder. Got.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 2.

<Comparative example 4>
The polymer solution (2) obtained in Production Example 2 was concentrated to 38.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was 420 g / min, the above 38.0% by mass polymer solution was fed at 352 g / min, and The poor solvent fed to the washing tank was carried out in the same manner as in Example 1 except that methanol was changed to 500 g / min to obtain a polyphenylene ether powder.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 2.

<Comparative Example 5>
The polymer solution (3) obtained in Production Example 3 was concentrated to 22.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to produce 125 kg of a polymer solution having a polymer concentration of 22.0% by mass.
As a poor solvent fed to the precipitation tank and a polymer solution, 240 g / min of methanol containing 3.0% by mass of water and 532 g / min of the 22.0% by mass of the polymer solution were fed into the tank. The paddle blade continued to run at 1500 rpm and operated continuously for about 230 minutes.
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.
In order to stabilize the operation, methanol was fed from a separate line at 350 g / min and stirred with the slurry liquid to replace and wash the toluene in the polyphenylene ether particles. 180 kg of a washing slurry liquid having a slurry concentration of 15% by mass was prepared.
The slurry was divided every 10 kg and filtered through a basket centle (Tanabe Wiltech model 0-15). After each filtration, in order to stabilize the operation, 1.5 kg of methanol was sprayed onto the wet polyphenylene ether in the basket centre and filtered again to obtain wet polyphenylene ether.
Next, the wet polyphenylene ether was put into a feather mill (FM-1S manufactured by Hosokawa Micron Co., Ltd.) set with a 10 mm round hole mesh, pulverized, held at 150 ° C. and 1 mmHg for 1.5 hours, and dried polyphenylene ether powder. Got.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 2.

<Comparative Example 6>
The polymer solution (3) obtained in Production Example 3 was concentrated to 38.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was 420 g / min, the above 38.0% by mass polymer solution was fed at 352 g / min, and The poor solvent fed to the washing tank was carried out in the same manner as in Example 1 except that methanol was changed to 500 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
The measurement results are shown in Table 2.

<Comparative Example 7>
The polymer solution (1) obtained in Production Example 1 was placed in a jacketed stirring tank, and heated by flowing a 120 ° C. heating medium 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. This operation was repeated to prepare 90 kg of a polymer solution having a polymer concentration of 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 that of International Publication No. 2003/064499.
222 g / min of methanol containing 3.0% by mass of water and 550 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 operation was continued for about 160 minutes.
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 at a rate of 700 g / min from a separate line, and the toluene in the polyphenylene ether particles was substituted and washed by stirring with the slurry liquid.
180 kg of a washing slurry liquid having a slurry concentration of 15% by mass was prepared.
The slurry was divided every 10 kg and filtered through a basket centle (Tanabe Wiltech model 0-15). 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.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 3 shows the measurement results.

<Comparative Example 8>
The polymer solution (1) obtained in Production Example 1 was concentrated to 38.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 345 g / min, the above 38.0% by mass polymer solution was fed at 427 g / min, and The poor solvent fed to the washing tank was carried out in the same manner as in Example 1 except that methanol was 700 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 3 shows the measurement results.

<Comparative Example 9>
The polymer solution (2) obtained in Production Example 2 was concentrated to 30.5% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 90 kg of a polymer solution having a polymer concentration of 30.5% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 222 g / min, and the above 30.5% by mass polymer solution was fed to the tank at 550 g / min. This was carried out in the same manner as in Example 1 except that methanol was 700 g / min as the poor solvent fed to the washing tank.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 3 shows the measurement results.

<Comparative Example 10>
The polymer solution (2) obtained in Production Example 2 was concentrated to 38.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 345 g / min, the above 38.0% by mass polymer solution was fed at 427 g / min, and The poor solvent fed to the washing tank was carried out in the same manner as in Example 1 except that methanol was set to 700 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 3 shows the measurement results.

<Comparative Example 11>
The polymer solution (3) obtained in Production Example 3 was concentrated to 30.5% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 90 kg of a polymer solution having a polymer concentration of 30.5% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was fed at 222 g / min and the above 30.5% by mass polymer solution was fed at 550 g / min, and the washing tank As the poor solvent fed to, the same procedure as in Example 1 was performed except that methanol was set to 700 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 3 shows the measurement results.

<Comparative Example 12>
The polymer solution (3) obtained in Production Example 3 was concentrated to 38.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 345 g / min, the above 38.0% by mass polymer solution was fed at 427 g / min, and The poor solvent fed to the washing tank was carried out in the same manner as in Example 1 except that methanol was set to 700 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 3 shows the measurement results.

<Example 7>
The polymer solution (3) obtained in Production Example 3 was concentrated to 30.5% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 30.5% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was adjusted to 250 g / min, and 522 g / min of the above 30.5% by mass polymer solution was fed into the tank. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was 250 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 4 shows the measurement results.

<Example 8>
The polymer solution (3) obtained in Production Example 3 was concentrated to 38.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 350 g / min, and 422 g / min of the above 38.0% by mass polymer solution was fed into the tank. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was 250 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 4 shows the measurement results.

<Example 9>
The polymer solution (3) obtained in Production Example 3 was concentrated to 43.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 43.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 450 g / min, and the above 43.0% by mass polymer solution was fed into the tank at 322 g / min. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was set to 150 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 4 shows the measurement results.

<Example 10>
The polymer solution (3) obtained in Production Example 3 was concentrated to 43.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 43.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was adjusted to 410 g / min, and 362 g / min of the above 43.0% by mass polymer solution was fed into the tank As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was 250 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 4 shows the measurement results.

<Example 11>
The polymer solution (3) obtained in Production Example 3 was concentrated to 47.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 47.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was adjusted to 475 g / min, and the above 47.0% by mass polymer solution was fed into the tank at 297 g / min. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was set to 150 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 4 shows the measurement results.

<Example 12>
The polymer solution (3) obtained in Production Example 3 was concentrated to 47.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 47.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 440 g / min, and 332 g / min of the above 47.0% by mass polymer solution was fed into the tank. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was 250 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 4 shows the measurement results.

<Comparative Example 13>
The polymer solution (3) obtained in Production Example 3 was concentrated to 43.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 43.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was adjusted to 460 g / min, and the above 43.0% by mass polymer solution was fed into the tank at 312 g / min. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was changed to 400 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 5 shows the measurement results.

<Comparative example 14>
The polymer solution (3) obtained in Production Example 3 was concentrated to 43.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 43.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 392 g / min, and 380 g / min of the above 43.0% by mass polymer solution was fed into the tank. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was 650 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 5 shows the measurement results.

<Comparative Example 15>
The polymer solution (3) obtained in Production Example 3 was concentrated to 47.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 47.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 500 g / min, and 272 g / min of the above 47.0% by mass polymer solution was fed into the tank. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was changed to 500 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 5 shows the measurement results.

<Comparative Example 16>
The polymer solution (3) obtained in Production Example 3 was concentrated to 47.0% by mass in the same manner as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 47.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 422 g / min, and the above 47.0% by mass polymer solution was fed into the tank at 350 g / min. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was changed to 700 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 5 shows the measurement results.

<Comparative Example 17>
The polymer solution (3) obtained in Production Example 3 was concentrated to 50.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 90 kg of a polymer solution having a polymer concentration of 50.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 440 g / min, and the above 50.0% by mass polymer solution was fed at 332 g / min. During operation, a polymer solution of 50.0% by mass was fed in a state heated to 113 ° C, but troubles such as clogging due to high viscosity occurred in the line, and stable production of polyphenylene ether powder. I could not.
<Comparative Example 18>
The polymer solution (3) obtained in Production Example 3 was concentrated to 20.0 mass% by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 20.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 560 g / min, and 212 g / min of the 20.0% by mass polymer solution was fed into the tank. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was changed to 200 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 6 shows the measurement results.
<Comparative Example 19>
The polymer solution (3) obtained in Production Example 3 was concentrated to 40.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 40.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 510 g / min, and 262 g / min of the above 40.0% by mass polymer solution was fed into the tank. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was 350 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 6 shows the measurement results.
<Comparative Example 20>
The polymer solution (3) obtained in Production Example 3 was concentrated to 40.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to prepare 70 kg of a polymer solution having a polymer concentration of 40.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was set to 312 g / min, and the above 40.0% by mass polymer solution was fed into the tank at g / min. As a poor solvent fed to the washing tank, a polyphenylene ether powder was obtained in the same manner as in Example 1 except that methanol was changed to 500 g / min.
Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder.
Table 6 shows the measurement results.

* In Comparative Example 17, the 50% by mass polymer solution became highly viscous in the pipe and could not be stably operated.
The symbols in Tables 1-6 are as follows.
MA: methanol Tol: toluene Poor solvent / good solvent: The mass ratio of the good solvent in the polymer solution added to the precipitation tank in the precipitation step and the poor solvent fed to the precipitation tank.
PPE: Polyphenylene ether Y1 = 18.032 · (X / 100) ² -1.1873 · (X / 100) -0.3463
Y2 = 14.891 * (X / 100) < ² > -0.9804 * (X / 100) -0.4602
X [mass%] is the polyphenylene ether concentration in the good solvent solution of polyphenylene ether added to the precipitation tank in the precipitation step.

As shown in Table 1, in Examples 1 to 6, in which the mass ratio of the poor solvent / good solvent was Y2 or more and Y1 or less, an appropriate fine powder ratio was obtained. As a result, the loose apparent specific gravity and the apparent specific gravity were higher than those of Comparative Examples 1 to 6, and a polyphenylene ether powder having practically good transportability was obtained.
Moreover, in Examples 1-6, it turned out that the difference with a loose apparent specific gravity or the apparent specific gravity is large, and close packing is possible and it is advantageous at the time of conveyance.
Further, as shown in Table 4, in Examples 7 to 12, the polyphenylene ether concentration in the good solvent of polyphenylene ether fed to the precipitation tank is increased stepwise, and Y is in the vicinity of Y1 or Y2. , Adjusted to a range of Y2 or more and Y1 or less. In Examples 7 to 12, an appropriate fine powder ratio was obtained, and as a result, a loose apparent specific gravity and a large difference in apparent specific gravity were possible, and fine filling was possible, and polyphenylene ether resin powder advantageous for transportation was obtained. It was.

In addition, as shown in Table 2, Comparative Examples 1, 3, and 5 have a high fine powder ratio and inferior transportability, and the polymer concentration used in the precipitation step is low, and the methanol is suitably used for operation stability. Therefore, the amount of the solvent used was significantly increased compared to the examples.
Furthermore, since Comparative Examples 2, 4, and 6 have a small apparent specific gravity, the transportability and handleability were inferior to those of the Examples.

As shown in Table 3, in Comparative Examples 7 to 12, the fine powder rate is extremely low, it is difficult to appropriately perform fine packing, and thus the apparent specific gravity value is lowered, and the transportability from a practical viewpoint. It was inferior to that.
Further, as shown in Table 5, in Comparative Examples 13 and 15, the fine powder ratio was too high, and the difference in apparent specific gravity was small due to the loose apparent specific gravity, so that fine packing could not be performed. In addition, the apparent specific gravity was small compared to the examples, and the transportability was poor.
Furthermore, as shown in Table 5, in Comparative Examples 14 and 16, the fine powder rate is very low, it is difficult to appropriately perform fine packing, and thus the apparent specific gravity value is low and the transportability is poor. It became a thing.

  As shown in Table 6, in Comparative Example 17, the viscosity of the polymer solution was high and operation was difficult. In Comparative Examples 18 to 20, the fine powder ratio was too high, and the difference in apparent specific gravity was small due to the loose apparent specific gravity, resulting in poor transportability.

  The method for producing a polyphenylene ether powder of the present invention has industrial applicability as a production technology for materials such as automobile parts, heat-resistant parts, electronic equipment parts, industrial parts, coating agents, and insulating coatings. .

Claims (12)

A polymerization step of polymerizing a phenol compound in a good solvent of polyphenylene ether to obtain a polymer solution;
A precipitation step of adding a polymer solution of the phenolic compound and a poor solvent for polyphenylene ether to a precipitation tank, and depositing polyphenylene ether to form a slurry;
Have
In the polymer solution added to the precipitation tank, the concentration of polyphenylene ether in a good solvent solution is X [mass%],
When the mass ratio (poor solvent / good solvent [wt / wt]) between the poor solvent fed into the precipitation tank and the good solvent in the polymer solution in the precipitation step is Y, the X and Y are A method for producing a polyphenylene ether powder satisfying the following formulas (I) and (II).
30 <X ≦ 48 (I)
14.891 · (X / 100) ² −0.9804 · (X / 100) −0.4602 ≦ Y ≦ 18.032 · (X / 100) ² −1.1873 · (X / 100) -0. 3463 (II)   The polymer solution obtained by the said polymerization process after the said polymerization process is heated more than the boiling point of the good solvent of the said polyphenylene ether, and the concentration process of obtaining the polymer solution which adjusted the polymer concentration is performed. Production method of polyphenylene ether powder.   The slurry produced by precipitating polyphenylene ether is washed with a poor solvent, and after solid-liquid separation to obtain wet polyphenylene ether, the method further comprises a step of mechanically crushing the wet polyphenylene ether. The manufacturing method of the polyphenylene ether powder as described in 2. above.   The method for producing a polyphenylene ether powder according to any one of claims 1 to 3, wherein the good solvent for the polyphenylene ether is at least one selected from the group consisting of benzene, toluene, and xylene.   The polyphenylene ether according to any one of claims 1 to 4, wherein the poor solvent of the polyphenylene ether is at least one selected from the group consisting of methanol, ethanol, isopropanol, n-butanol, acetone, methyl ethyl ketone, and water. Powder manufacturing method.   The manufacturing method of the polyphenylene ether powder as described in any one of Claims 1 thru | or 5 with which the poor solvent of the said polyphenylene ether contains 0.05-30 mass% water in the said poor solvent.   The said precipitation tank is equipped with an at least one stage stirring blade selected from the group consisting of an inclined paddle blade, a screw blade, and a ribbon blade, and stirring is performed by the stirring blade in the precipitation step. The manufacturing method of the polyphenylene ether powder as described in any one of these.   The manufacturing method of the polyphenylene ether powder as described in any one of Claims 1 thru | or 7 which uses what is equipped with at least 1 baffle as said precipitation tank.   The precipitation tank includes a draft tube, and the draft tube includes at least one stirrer blade selected from the group consisting of the inclined paddle blade, screw blade, and ribbon blade, and the stirring blade inside the draft tube The method for producing a polyphenylene ether powder according to claim 7 or 8, wherein a lower discharge blade is used and stirring is performed by the stirring blade in the precipitation step.   The precipitation tank further includes a stirring blade that is a ribbon blade on the outside of the draft tube, and the stirring blade outside the draft tube is an upper discharge blade. In the precipitation step, a ribbon outside the draft tube is used. The method for producing a polyphenylene ether powder according to claim 9, wherein stirring is performed with a stirring blade which is a blade.   The manufacturing method of the polyphenylene ether powder as described in any one of Claims 1 thru | or 10 whose liquid temperature in the said precipitation process is 30-63 degreeC.   The method for producing polyphenylene ether powder according to any one of claims 1 to 11, wherein the residence time of the polyphenylene ether in the precipitation tank is 0.25 to 5 minutes.