JP2013256644A - Method for producing polyphenylene ether powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for stably producing PPE (polyphenylene ether) powders having a uniform small particle size and less residual solvent amount, excellent in solubility in a solvent and compatible with a liquid additive without causing troubles such as scale adherence.SOLUTION: A method for producing PPE (polyphenylene ether) powders includes a polymerization step of polymerizing a phenol compound in a good solvent for PPE to obtain a polymer solution, and a precipitation step of adding the polymer solution and a poor solvent for PPE into a precipitation tank and precipitating PPE 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): 18.032×(X/100)-1.1873×(X/100)-0.3463≤Y≤22.430×(X/100)-1.4769×(X/100)-0.1868 (wherein X is the concentration [mass%] of PPE in a good solvent solution; and Y is the mass ratio (poor solvent/good solvent) of the poor solvent added to 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 a polyphenylene ether powder.

  Conventionally, a modified PPE resin using polyphenylene ether (hereinafter sometimes simply referred to as “PPE”) as a raw material is produced by a molding method such as a melt injection molding method or a melt extrusion molding method. Since it can produce parts, it is widely used as a material for products and parts in the electric / electronic field, automobile field, and other various industrial material fields.

In recent years, as a new industrial application of PPE, an application as a composite material for obtaining excellent characteristics in combination with other resins, an application for coating a surface, and the like have been studied. In particular, in applications where PPE is dissolved in an aromatic organic solvent such as benzene and toluene, and coating is performed on an inorganic surface such as metal, glass, and metal oxide, and an organic surface such as wood and resin by coating and coating. It is important to have good dissolution characteristics, excellent adhesion to the coating surface, and high mechanical strength, and there is a need for PPE that satisfies these characteristics.
In addition, when melt-kneading PPE with a liquid additive such as a flame retardant, it is required as a characteristic that the PPE is easily compatible with the liquid additive, that is, excellent in solvent solubility.

As described above, when the PPE powder is combined with another resin, a melt-kneading process is performed. However, the particle size of the PPE powder greatly affects the operational stability of the melt-kneading process.
Specifically, when there are many fine powders in the PPE powder, the bulk specific gravity becomes low, which may cause a problem that the supply stability is lowered due to generation of a gas backflow or bridge.
Further, when there are many large particles in the PPE powder, an unmelted polymer is generated in a melt-kneading apparatus such as a twin-screw extruder. Therefore, it is necessary to process at a high temperature in order to completely dissolve the polymer. However, melt-kneading at a high temperature is not preferable because there is a risk of degrading the quality of PPE.
Furthermore, when the particle size distribution of the PPE powder is wide, large particles and fine powder are classified in the PPE powder supply tank, and a case where there are many fine powders and a case where there are many large particles are generated sequentially. Absent.
From the above, in order to stably process the PPE powder, there is a demand for a PPE powder having a uniform particle size and a high bulk specific gravity.

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

  In the conventional method for producing PPE described above, the precipitated PPE particles have a large particle size, which has a problem of poor drying and a large amount of residual solvent. In addition, the PPE powder produced by the conventional PPE production method described above has a problem that the solvent solubility is poor and it is difficult to become familiar with the liquid additive. Further, the PPE powder produced by the above-described conventional PPE production method has a residual solvent volatilized when the PPE powder is compounded and processed into a modified PPE resin, and the residual solvent is obtained by an extruder or the like in the melt-kneading process. When the gas backflows, there is a problem that a biting defect occurs or the working environment is deteriorated by the volatilized solvent gas.

As described above, the reason why the residual solvent amount of the PPE particles produced in the conventional method for producing PPE increases is that the phenomenon in which the particle size of the PPE particles fluctuates periodically during the precipitation process, and includes uneven particles. For example, the PPE particles are further crushed in the post-treatment step after the precipitation step, and the particle size distribution is expanded.
Further, in the conventional PPE manufacturing method described above, since the PPE precipitation step is performed in a region where the concentration of PPE is low, a large amount of solvent is required, which is inefficient. In the case of use, there is a problem that the collection cost becomes large.

  Patent Document 1 discloses a technique for obtaining PPE with a reciprocating stirrer that produces less powder in the subsequent process and less intrusion into the extruder, but lacks stability during the precipitation process operation. In addition, the particle size is periodically changed to generate large particles or fine powder.

Patent Document 2 discloses a technique for precipitating PPE particles having a uniform particle diameter using a draft tube type precipitation apparatus, but the technique is a precipitation technique in a region where the polymer concentration is low, There is a problem that the amount of solvent used is increased and inefficient.
In addition, the PPE particles obtained by the technique have insufficient strength, and are pulverized in a post-processing step (for example, a slurry pump, a solid-liquid separator, etc.) after the PPE particle precipitation step, and the particle size distribution becomes wide. It also has the problem.

Furthermore, Patent Document 3 discloses a technique that defines the stirring speed, the polymer concentration, the precipitation temperature, the amount of poor solvent, and the like during precipitation in order to suppress fine powder loss, filter clogging, and extruder biting failure.
However, the technique described in Patent Document 3 also includes precipitation in a region where the polymer concentration is low, and has a problem that the precipitation is unstable and inefficient.

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

In the conventional PPE manufacturing technique described above, the purpose is to reduce the fine powder in the precipitation step to increase the particle size. However, although the particles are surely enlarged at the time of the precipitation step, the strength of the particles is not sufficient and there is room for improvement. In particular, when manufacturing PPE on an industrial scale, the PPE particles are crushed through the slurry transfer pump, solid-liquid separator, dryer, powder transfer device, etc. even if the particles become large at the time of the precipitation step. , PPE powder having a wide particle size distribution from fine powder to large particles is produced.
Further, since many large particles are contained, the amount of residual solvent in the particles increases, and various problems occur during melt processing.
Furthermore, in the conventional PPE manufacturing technology described above, since the polymer concentration is precipitated in a low region, there is a problem that the amount of solvent used is large, and when the solvent is recovered and used, the recovery cost is also great. Yes.
Furthermore, since the PPE powder produced by the above-mentioned conventional PPE production technology has a wide particle size distribution from fine powder to large particles, when melt processing with a twin screw extruder, Among them, large particles and fine powder are classified, and by the classification, the PPE powder supplied initially becomes mainly fine powder, and the supply becomes unstable due to gas backflow, bridge in the hopper, etc. There is a problem that it is difficult to stably operate the processing apparatus. In addition, due to classification, the PPE powder supplied later is mainly composed of large particles, and there is a problem that unmelted portions are likely to occur.
As described above, the PPE particle precipitation method in the conventional PPE manufacturing technology does not sufficiently meet the demands of the industry and has room for improvement.

  Therefore, in the present invention, to produce a PPE powder that is fine and uniform in particle size, has a small amount of residual solvent, has excellent solvent solubility, and is easily compatible with liquid additives. Strong PPE powder that can reduce the change in particle size in the post-treatment process after the precipitation process is stable without causing problems such as scale adhesion, and the amount of solvent used is reduced compared to the prior art. It is an object to provide a method for producing PPE powder that can be produced.

As a result of intensive studies 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 in the ratio of poor solvent and good solvent, By satisfying the predetermined relationship, it has been found that strong and uniform small particles whose particle size does not change even in the post-treatment step can be obtained, 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) of the poor solvent added to the precipitation tank and the good solvent in the polymer solution in the precipitation step is Y, the X and Y are represented by the following formula (I), A method for producing a polyphenylene ether powder that satisfies (II).
30 <X ≦ 48 (I)
18.032 ・ (X / 100) ² −1.1873 ・ (X / 100) −0.3463 ≦ Y ≦ 22.430 ・ (X / 100) ² −1.4769 ・ (X / 100) −0.1868 (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 slurry produced by precipitating polyphenylene ether is washed with a poor solvent, solid-liquid separation is performed to obtain wet polyphenylene ether, and then the wet polyphenylene ether is mechanically crushed, [1] Or the manufacturing method of the polyphenylene ether powder as described in [2].
[4]
The method for producing a polyphenylene ether powder according to any one of [1] to [3], wherein the good solvent of 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 stirring blade selected from the group consisting of the inclined paddle blade, the screw blade, and the 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]
The precipitation tank further includes a stirring blade that is a ribbon blade on the outside of the draft tube, and the stirring blade on the outside of the draft tube is an upper discharge blade, and in the precipitation step, the outer surface of the draft tube is used. The method for producing a polyphenylene ether powder according to [9], wherein stirring is performed with a stirring blade that is a ribbon blade.
[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 a residence time of the polyphenylene ether in the precipitation tank is 0.25 to 5 minutes.

According to the method for producing PPE powder of the present invention, PPE powder having a small particle size, a small amount of residual solvent, excellent solvent solubility, and easily compatible with liquid additives causes troubles such as scale adhesion. And can be manufactured stably.
In addition, according to the method for producing PPE powder of the present invention, strong PPE particles with very little change in particle size can be obtained even in a post-treatment step after the precipitation step.
Furthermore, the method for producing PPE particles of the present invention can reduce the amount of solvent used compared to the prior art, and can greatly improve production efficiency.

  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 PPE to obtain a polymer solution;
Thereafter, optionally, a concentration step of heating the polymer solution obtained in the polymerization step to a temperature equal to or higher than the boiling point of the good solvent to obtain a polymer solution with adjusted polymer concentration;
A precipitation step of adding a polymer solution after the polymerization step or a polymer solution after the concentration step and a poor solvent for PPE to the precipitation tank to precipitate PPE to form a slurry;
Have
In the polymer solution to be added to the precipitation tank, the concentration of PPE in the good solvent solution is X [mass%],
When the mass ratio (poor solvent / good solvent [wt / wt]) of the poor solvent added to the precipitation tank and the good solvent in the polymer solution in the precipitation step is Y,
In the method for producing polyphenylene ether powder, X and Y satisfy the following formulas (I) and (II).
30 <X ≦ 48 (I)
18.032 ・ (X / 100) ² −1.1873 ・ (X / 100) −0.3463 ≦ Y ≦ 22.430 ・ (X / 100) ² −1.4769 ・ (X / 100) −0.1868 (II)
The “concentration (X mass%) of PPE in a good solvent solution” means the concentration of the polymer solution obtained in the polymerization step or concentration step described above, and the good solvent charged in advance in the precipitation tank, The good solvent of the so-called initial charge liquid is not included in the conversion of the concentration.
The “poor solvent to be added to the precipitation tank in the precipitation step” used for calculation of Y (poor solvent / good solvent) means that after the initial charging to the precipitation tank is completed, the polymer solution is added, and then It means a poor solvent added for precipitating PPE, and does not include a poor solvent charged in advance in the precipitation tank, that is, a poor solvent of a so-called initial charge liquid.
Furthermore, “good solvent in polymer solution” used for calculation of Y (poor solvent / good solvent) means a good solvent in the polymer solution obtained in the above-described polymerization step or concentration step. The liquid good solvent shall not be included.

(Polyphenylene ether (PPE))
In the polymerization step in the method for producing PPE powder of this embodiment, a phenol compound is polymerized in a good solvent of polyphenylene ether to obtain a polymer solution of PPE.
The PPE will be described below.
In the PPE powder production method of the present embodiment, the PPE produced by the polymerization step is a homopolymer and / or copolymer having a repeating unit structure represented by the following formula (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, a bromine atom, and the like, from the viewpoint that the polymerization reaction can be performed with high activity. , 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 linear or branched having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. The chain alkyl group is not limited to the following, and examples thereof include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl and the like. From the viewpoint that the polymerization reaction can be performed with high activity, 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.
Examples of such a substituent include, but are not limited to, for example, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom), an alkyl group having 1 to 6 carbon atoms (for example, methyl, ethyl, Propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl), aryl groups (eg, phenyl, naphthyl), alkenyl groups (eg, ethenyl, 1-propenyl, 2-propenyl), alkynyl groups ( For example, ethynyl, 1-propynyl, 2-propynyl), aralkyl group (for example, benzyl, phenethyl), alkoxy group (for example, methoxy, ethoxy) and the like can be mentioned.

The reduced viscosity when measured at 30 ° C. using a chloroform solution in which 0.5 g of PPE is dissolved in 1 dL of chloroform is preferably in the range of 0.15 to 1.0 dL / g, more preferably 0.8. 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.
When the reduced viscosity is 0.15 dL / g or more, the mechanical properties of the PPE powder can be improved.
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 related to the molecular weight of the PPE is 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) can be used to apply the measurement conditions. it can. The UV wavelength of the detection unit can be selected from 254 nm for standard polystyrene and 283 nm for PPE, respectively.

  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 PPE 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 sufficient mechanical properties in the PPE powder, 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 35,000. The following is preferable.

The PPE dispersity (Mw / Mn) 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. is there.
Further, the degree of dispersion of the PPE is preferably 1.6 or more, more preferably 1.8 or more, still more preferably 1.9 or more, and even more preferably 2.0 or more.
When the degree of dispersion is in the above range, the balance between the low molecular weight component and the high molecular weight component is good, and PPE having such a degree of dispersion is excellent in the balance between chemical resistance and fluidity.

The PPE 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 PPE itself.
It is preferable from the viewpoint of the high purity of PPE that the amount of residual metal catalyst is less than 1.0 ppm. Further, if the amount of residual metal catalyst is less than 1.0 ppm, it is preferable because yellowish color after heat history can be suppressed. Preferably it is less than 0.8 ppm, 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 amount of residual metal catalyst of PPE can be measured with an atomic absorption photometer.

(Polyphenylene ether polymerization process)
In the polymerization step in the method for producing the polyphenylene ether powder of the present embodiment, the phenol compound is polymerized in a good solvent of polyphenylene ether to obtain a polymer solution of PPE represented by the formula (1).
<Monomer used in polymerization step>
PPE represented by the above formula (1) can be produced by polymerizing the following phenol compounds.
Examples of the phenol compound include, but are not limited to, 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-phenylphenol, 2,6-diphenylphenol, 2,6-bis- (4-fur Rophenyl) phenol, 2-methyl-6-tolylphenol, 2,6-ditolylphenol, 2,5-dimethylphenol, 2,3,6-trimethylphenol, 2,5-diethylphenol, 2-methyl-5- Ethylphenol, 2-ethyl-5-methylphenol, 2-allyl-5-methylphenol, 2,5-diallylphenol, 2,3-diethyl-6-n-propylphenol, 2-methyl-5-chlorophenol, 2-methyl-5-bromophenol, 2-methyl-5-isopropylphenol, 2-methyl-5-n-propylphenol, 2-ethyl-5-bromophenol, 2-methyl-5-n-butylphenol, 2, 5-di-n-propylphenol, 2-ethyl-5-chlorophenol, 2-methyl-5-pheny Phenol, 2,5-diphenylphenol, 2,5-bis- (4-fluorophenyl) phenol, 2-methyl-5-tolylphenol, 2,5-ditolylphenol, 2,6-dimethyl-3-allylphenol 2,3,6-triallylphenol, 2,3,6-tributylphenol, 2,6-di-n-butyl-3-methylphenol, 2,6-di-t-butyl-3-methylphenol, 2, , 6-dimethyl-3-n-butylphenol, 2,6-dimethyl-3-t-butylphenol and the like.
In particular, from the viewpoint of being inexpensive and readily available, 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-diphenylphenol, 2,3,6-trimethylphenol, 2,5-dimethylphenol 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, Examples thereof include a method using a combination of trimethylphenol 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.

As a monomer used for the polymerization step, a divalent phenol compound represented by the following formula (2) may be contained in addition to the above phenol compound.
The divalent phenol 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 reaction or the like.
For example, a compound group obtained by reaction of a monovalent phenol compound with a general-purpose ketone compound such as formaldehyde, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, cyclohexane, or a compound group obtained by reaction of monovalent phenol compounds. Can be mentioned.
The divalent phenolic compound represented by the following formula (2) is not limited to the following, but for example, the following general formulas (2-a), (2-b), (2-c) The compound represented by these is mentioned.

Representative compounds represented by the above formula (2) are not limited to the following. For example, R ₅ and R ₆ are methyl groups, R ₇ and R ₈ are hydrogen, and X is both aryl. A compound in which 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 Wherein 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 isopropyl Ridene compound, 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 X A compound in which both aryl groups are directly connected, a compound in which R ₅ , R ₆ and R ₇ are methyl groups, R ₈ is hydrogen and X is methylene, R ₅ , R ₆ and R ₇ are methyl groups, R ₈ is hydrogen and X is ethylene, R ₅ , R ₆ and R ₇ are methyl groups, R ₈ is hydrogen and 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, R ₅ , R ₆ , R ₇ and R ₈ are methyl groups and X is ethylene, and R ₅ , R ₆ , R ₇ and R ₈ are methyl groups and X is isopropylidene.

In the polymerization process of PPE, in addition to the above-described phenol compound and divalent phenol compound, a polyhydric phenol compound may coexist. Examples of the polyhydric phenol compound include, but are not limited to, for example, a fragrance having 3 or more and less than 9 phenolic hydroxyl groups in the molecule and at least one phenolic hydroxyl group therein. Examples thereof include compounds having an alkyl group or an alkylene group at the 2,6-positions of the ring.
Specific examples of the polyhydric phenol compound are listed below.
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-to Limethylphenol), 2,2 ′-[(4-hydroxyphenyl) methylene] bis (3,5,6-trimethylphenol), 4,4 ′-[4- (4-hydroxyphenyl) cyclohexylidene] bis (2,6-dimethylphenol), 4,4 ′-[(2-hydroxyphenyl) methylene] -bis (2,3,6-trimethylphenol), 4,4 ′-[1- [4- [1- (4-Hydroxy-3,5-dimethylphenyl) -1-methylethyl] phenyl] ethylidene] bis (2,6-dimethylphenol), 4,4 ′-[1- [4- [1- (4-hydroxy) -3-fluorophenyl) -1-methylethyl] phenyl] ethylidene] bis (2,6-dimethylphenol), 2,6-bis [(4-hydroxy-3,5-dimethylphenyl) ethyl] -4-methyl Phenol, 2,6-bis [(4-hydroxy Cis-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-methylphenyl) methyl] -6-cyclohexylphenol, 2,4-bis [(4-hydroxy-2,3,6-trimethylphenyl) methyl] -6 -Cyclohexylphenol, 3,6-bis [(4-hydroxy-3,5-dimethylphenyl) methyl] -1,2-benzenediol, 4,6-bis [(4-hydroxy-3,5-dimethylphenyl) Methyl] -1,3-benzenediol, 2,4,6-tris [(4-hydroxy-3,5-dimethylphenyl) methyl] -1,3-benzenediol, 2,4,6-tris [(2 -Hydroxy-3,5-dimethylphenyl) methyl] -1,3-benzenediol, 2,2'-methylenebis [6-[(4 / 2-hydroxy-2,5 / 3,6-dimethylphenyl) methyl] -4-methylphenol], 2,2'-methylenebis [6-[(4-hydroxy-3,5-dimethylphenyl) methyl] -4-methylphenol], 2,2'-methylenebis [6-[(4 / 2-hydroxy-2,3,5 3,4,6-trimethylphenyl) methyl] -4-methylphenol], 2,2′-methylenebis [6-[(4-hydroxy-2,3,5-trimethylphenyl) methyl] -4-methylphenol] 4,4'-methylenebis [2-[(2,4-dihydroxyphenyl) methyl] -6-methylphenol], 4,4'-methylenebis [2-[(2,4-dihydroxyphenyl) methyl] -3 , 6-Dimethylphenol], 4,4′-methylenebis [2-[(2,4-dihydroxy-3-methylphenyl) methyl] -3,6-dimethylphenol], 4,4′-methylenebis [2- [ (2,3,4-trihydroxyphenyl) methyl] -3,6-dimethylphenol], 6,6′-methylenebis [4-[(4-hydroxy-3,5-dimethylphenyl) methyl] -1,2 , 3-Benzenetriol], , 4′-cyclohexylidenebis [2-cyclohexyl-6-[(2-hydroxy-5-methylphenyl) methyl] phenol], 4,4′-cyclohexylidenebis [2-cyclohexyl-6-[(4 -Hydroxy-3,5-dimethylphenyl) methyl] phenol], 4,4'-cyclohexylidenebis [2-cyclohexyl-6-[(4-hydroxy-2-methyl-5-cyclohexylphenyl) methyl] phenol] 4,4′-cyclohexylidenebis [2-cyclohexyl-6-[(2,3,4-trihydroxyphenyl) methyl] phenol], 4,4 ′, 4 ″, 4 ″ ′-(1,2 -Ethanediylidene) tetrakis (2,6-dimethylphenol), 4,4 ', 4 ", 4"'-(1,4-phenylenedimethylidene) tetrakis (2,6-dimethylphenol) However, it is not limited to these.
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 compound is 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 PPE powder of this embodiment, first, the above-described phenol compound is polymerized by solution polymerization to obtain a polymer solution containing PPE (polymerization step).
In addition, the polymer solution obtained in the polymerization step is a polymer solution that is concentrated by heating to the boiling point of the good solvent or higher and adjusting the polymer concentration, as described later, as a pre-stage for carrying out the precipitation step described later. May be obtained (concentration step). The concentration step is optional.
Next, as described later, PPE is precipitated by mixing with a poor solvent for PPE to produce a slurry (precipitation step).
Solution polymerization is a polymerization method in which polymerization is performed in a good solvent for PPE, and precipitation of PPE does not occur during the polymerization. All PPE molecules obtained by solution polymerization are in a dissolved state, and the molecular weight distribution tends to be wide. Particulate PPE is obtained by implementing the concentration process with respect to the polymer solution in which PPE melt | dissolved as needed, and performing the precipitation process mixed with the poor solvent of PPE, such as methanol after that, after that.

<Good PPE solvent used in polymerization process>
The good solvent for PPE used in the polymerization step is not limited to the following, but at least one selected from the group consisting of benzene, toluene, and xylene is preferable from the viewpoint of PPE solubility.

  The polymerization method of PPE is not limited to the following. For example, 2,6-xylenol is oxidatively polymerized using a complex of cuprous salt and amine described in US Pat. No. 3,306,874 as a catalyst. A method is mentioned. Further, the methods described in US 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, etc. Is also preferable as a method for producing PPE.

From the viewpoint of efficiently producing PPE and from the viewpoint of producing PPE having a molecular weight distribution (dispersion degree) in the preferred range described above, the monomer concentration in the polymerization step is 10 to 30% by mass based on the total amount of the polymerization solution. Preferably, 13 to 27 mass% is more preferable. When the concentration is 10% by mass or more, the production efficiency of PPE increases.
On the other hand, when the concentration exceeds 30% by mass, it tends to be difficult to adjust to the above-mentioned preferred number average molecular weight. The present inventors presume this cause as follows. That is, when the monomer concentration exceeds 30% by mass, the liquid viscosity at the end of polymerization becomes high, and uniform stirring becomes difficult. For this reason, a heterogeneous reaction occurs, and an unexpected molecular weight PPE may be obtained. As a result, as described above, it may be difficult to efficiently produce PPE having a number average molecular weight of 7,000 to 35,000.

The polymerization process of PPE is performed while supplying an oxygen-containing gas.
Examples of the oxygen-containing gas include pure oxygen, oxygen and an inert gas such as nitrogen mixed at an arbitrary ratio, and air, air and an inert gas such as nitrogen or a rare gas mixed at an arbitrary ratio. Can be used.

The pressure in the reaction system in the polymerization step may be normal pressure, or may be reduced or increased as necessary.
Although the supply rate of the oxygen-containing gas described above 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 10 NmL / Min or more is more preferable.

In the polymerization process of PPE, neutral salts such as alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal alkoxides, magnesium sulfate, calcium chloride, etc. Zeolite or 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. From the viewpoint of controlling the molecular weight, the amount of the surfactant used is preferably within a range not exceeding 0.1 mass% with respect to the total amount of the polymerization reaction raw material.

In the polymerization process of PPE, a known catalyst generally used for production of PPE may be added to the reaction system.
Examples of the catalyst include, but are not limited to, a catalyst composed of a transition metal ion having oxidation-reduction ability and an amine compound capable of complexing with the metal ion. Examples thereof include a catalyst system composed of a compound and an amine, a catalyst system composed of a manganese compound and an amine, and a catalyst system composed of a cobalt compound and an amine.

  In the polymerization process of PPE, since the polymerization reaction proceeds efficiently under some alkaline conditions, it is preferable to add some alkali or amine. As a suitable catalyst in the polymerization process of PPE, a catalyst containing a copper compound, a halogen compound, and a diamine compound represented by the following formula (3) can also be exemplified.

In the formula (3), R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently selected from the group consisting of a hydrogen atom and a linear or branched alkyl group having 1 to 6 carbon atoms. Indicates either.
Note that all of R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are not hydrogen at the same time.
R ₁₃ represents a linear or branched alkylene group having 2 to 5 carbon atoms.

  Examples of the diamine compound represented by the above formula (3) include, but are not limited to, N, N, N ′, N′-tetramethylethylenediamine, N, N, N′-trimethylethylenediamine, N , N′-dimethylethylenediamine, N, N-dimethylethylenediamine, N-methylethylenediamine, N, N, N ′, N′-tetraethylethylenediamine, N, N, N′-triethylethylenediamine, N, N′-diethylethylenediamine, N, N-diethylethylenediamine, N-ethylethylenediamine, N, N-dimethyl-N′-ethylethylenediamine, N, N′-dimethyl-N-ethylethylenediamine, Nn-propylethylenediamine, N, N′-di- n-Propylethylenediamine, Ni-Propylethylene Diamine, N, N'-di-i-propylethylenediamine, Nn-butylethylenediamine, N, N'-di-n-butylethylenediamine, Ni-butylethylenediamine, N, N'-di-i-butyl Ethylenediamine, Nt-butylethylenediamine, N, N′-di-t-butylethylenediamine, N, N, N ′, N′-tetramethyl-1,3-diaminopropane, N, N, N′-trimethyl- 1,3-diaminopropane, N, N′-dimethyl-1,3-diaminopropane, N-methyl-1,3-diaminopropane, N, N, N ′, N′-tetramethyl-1,3-diamino -1-methylpropane, N, N, N ′, N′-tetramethyl-1,3-diamino-2-methylpropane, N, N, N ′, N′-tetramethyl-1,4-diamy Butane, N, N, N ', N'- tetramethyl-1,5-diaminopentane, and the like.

Preferred diamine compounds are those having 2 or 3 carbon atoms in the alkylene group (R ₁₃ ) connecting two nitrogen atoms in the formula (3) from the viewpoint of the ability to form a complex with a metal catalyst.
Although the usage-amount of these diamine compounds is not specifically limited, Usually, it is used in the range of 0.01 mol-10 mol with respect to 100 mol of phenolic compounds used at a superposition | polymerization process.

As said copper compound which comprises a catalyst, a cuprous compound, a cupric compound, or a mixture thereof can be used. Examples of the cuprous compound include, but are not limited to, 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 from the viewpoint of polymerization reaction activity.
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, cuprous chloride 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 include, but are not limited to, 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 may 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 from the viewpoint of polymerization activity.

  Although the usage-amount of the copper compound and halogen compound which comprise a catalyst is not specifically limited, When using both a copper compound and a halogen compound, it is preferable that a halogen atom is 2 times-20 times with respect to the number of moles to a copper atom, The preferred amount of copper atom used per 100 moles of the phenol compound used is in the range of 0.02 moles to 0.6 moles.

As a catalyst used in the polymerization step, for example, a tertiary monoamine compound or a secondary monoamine compound may be contained alone or in combination in addition to the above-described compounds.
The tertiary monoamine compound is an aliphatic tertiary amine including an alicyclic tertiary amine. Examples of the tertiary monoamine compound include, but are not limited to, 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. Although the usage-amount is not specifically limited, 15 mol or less is preferable with respect to 100 mol of phenolic compounds used in a superposition | polymerization process.
Examples of the secondary monoamine compound include secondary aliphatic amines.
Examples of secondary aliphatic amines include, but are not limited to, dimethylamine, diethylamine, di-n-propylamine, di-i-propylamine, di-n-butylamine, di-i- Examples include butylamine, di-t-butylamine, dipentylamines, dihexylamines, dioctylamines, didecylamines, dibenzylamines, methylethylamine, methylpropylamine, methylbutylamine, and cyclohexylamine.
Further, as the secondary monoamine compound, a secondary monoamine compound containing an aromatic can also be applied. Although not limited to the following, for example, N-phenylmethanolamine, N-phenylethanolamine, N-phenylpropanolamine, N- (m-methylphenyl) ethanolamine, N- (p-methylphenyl) ethanol Amine, N- (2 ′, 6′-dimethylphenyl) ethanolamine, N- (p-chlorophenyl) ethanolamine, N-ethylaniline, N-butylaniline, N-methyl-2-methylaniline, N-methyl- Examples include 2,6-dimethylaniline and diphenylamine. 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 used in a superposition | polymerization process.
The tertiary and secondary monoamine compounds do not need to be added from the beginning to the reaction system in the polymerization step in the whole amount usually 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.

(Post-treatment after polymerization of polyphenylene ether)
A predetermined post-treatment step may be performed after the polymerization step described above.
The specific method of the post-treatment step is not particularly limited, but usually an acid such as hydrochloric acid or acetic acid, ethylenediaminetetraacetic acid (EDTA) and its salt, nitrilotriacetic acid and its salt, etc. are used as a reaction solution. In addition, there is a method of deactivating the catalyst.
The polymerization solution at the end of the polymerization is in a state where PPE is dissolved in a good solvent. Therefore, for the purpose of washing and removing the catalyst, a solvent such as water, which has low PPE solubility and phase-separates with the good solvent of PPE, is used. It is preferable to repeatedly perform cleaning treatment using a solution containing the main component.

(Concentration process)
In the method for producing PPE of the present embodiment, the polymer solution of PPE obtained in the polymerization step described above is heated to the boiling point of the good solvent or more as necessary, and the vaporized good solvent is extracted out of the system. It may be concentrated.

(PPE concentration in a good solvent solution)
In the method for producing the polyphenylene ether powder of the present embodiment, when the PPE polymer solution obtained in the polymerization step described above is added to the precipitation tank in the precipitation step described later, the concentration of PPE in the good solvent solution ( X (mass%) is 30 <X ≦ 48 (I).
The concentration (X (mass%)) of the PPE in the good solvent solution may be adjusted by increasing the concentration in the concentration step so as to be in the range of the formula (I).
X is preferably 44% by mass or less, and more preferably 40% by mass or less. X is preferably 39% by mass or more, and more preferably 38% by mass or more.

(Polyphenylene ether precipitation process)
In the PPE precipitation step, first, as the initial charge liquid of the precipitation tank, from the viewpoint of stable operation, the poor solvent and the good solvent have a mass ratio (initial charge poor solvent / initial charge good solvent) of 0. It is preferable to charge so that it may become the range of 4-1.5.
The polymer solution obtained through the polymerization step described above or the concentration step described above and a poor solvent are added to the precipitation tank and stirred. Thereby, PPE precipitates and a slurry is generated.
In the said precipitation process, the density | concentration X (mass%) of the PPE in the good solvent in the polymer solution added to a precipitation tank shall be 30 <X <= 48 ... (I).
As described above, by making the PPE concentration in the good solvent solution of PPE higher than 30% by mass, the use amount of the poor solvent for precipitating PPE in the precipitation step can be suppressed, which is preferable in terms of production efficiency. Also, when the poor solvent is recovered and used, it is preferable because the recovery cost can be reduced. Moreover, by setting the PPE concentration in the good solvent of PPE to 48% by mass or less, the liquid viscosity can be appropriately adjusted, and the equipment cost of peripheral equipment such as a pump can be suppressed. Further, since it is not necessary to prevent the polymer from being solidified by maintaining it at an excessively high temperature, a sufficiently smooth operation can be achieved practically.
Moreover, in the said precipitation process, when the mass ratio (poor solvent / good solvent) of the poor solvent added to a precipitation tank and the good solvent in the said polymer solution is set to Y, the fluid state in a precipitation tank is following Formula ( It is stable within a range satisfying II).
18.032 ・ (X / 100) ² −1.1873 ・ (X / 100) −0.3463 ≦ Y ≦ 22.430 ・ (X / 100) ² −1.4769 ・ (X / 100) −0.1868 (II)
As described above, the precipitation step of the polyphenylene ether powder production method of the present embodiment exceeds the PPE-containing polymer solution concentration (X) charged into the precipitation tank, as shown in the above formula (I), exceeding 30% by mass. The mass ratio of the poor solvent fed to the precipitation tank to the good solvent in the polymer solution (poor solvent / good solvent) = Y is adjusted to the range shown in the above formula (II) under the condition of 48% by mass or less. And do it.
In addition, in the said precipitation process, PPE containing polymer solution concentration (X) thrown into a precipitation tank means the density | concentration of the polymer in the good solvent in the polymer solution obtained by the superposition | polymerization process or concentration precipitation process mentioned above. In addition, the good solvent of the initial charge liquid is not included.
In the precipitation step, the poor solvent to be added to the precipitation tank means a poor solvent that is fed to precipitate PPE while the polymer solution is added after the initial preparation of the precipitation tank is completed, The poor solvent of the initial charge liquid is not included.
Furthermore, “mass of good solvent in polymer solution” used for calculation of Y means the mass of good solvent in the polymer solution obtained in the polymerization step or concentration step described above, and the mass of good solvent in the initial charge solution. Shall not be included.
That is, in this specification, Y = (poor solvent added 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 is within the range shown in the above formula (II), The flow state of the polymer can be stabilized, the scale of the deposited polymer to the deposition tank can be effectively suppressed, and the PPE particles can be stably deposited.
In addition, the said scale means the state which precipitated PPE adhered to the side of the precipitation tank, the stirring shaft, etc. Thereby, the raw material (polymer) density | concentration in a system becomes non-constant, and a loss polymer increases. This causes a problem.

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

As described above, in this embodiment, when the ratio of the mass of the poor solvent to be added to the good solvent in the polymer solution (poor solvent / good solvent) is Y in the PPE precipitation step, Y is the precipitation tank. The concentration of PPE in the good solvent solution of the polymer solution to be added to is within the range represented by the following formula (II) using X (mass%).
18.032 ・ (X / 100) ² −1.1873 ・ (X / 100) −0.3463 ≦ Y ≦ 22.430 ・ (X / 100) ² −1.4769 ・ (X / 100) −0.1868 (II)
When Y is within the range of the above formula (II), the flow state in the precipitation tank is extremely stable, and as a result, PPE particles having a small particle size and a very small variation in the particle size distribution can be obtained.
Further, since the flow state is stable, the scaling in the precipitation tank is extremely small, and stable operation is possible.

  By controlling the mass of the polymer solution and the poor solvent added to the precipitation tank, the relationship between the mass of the good solvent and the mass of the poor solvent in the polymer solution can be controlled within the range of the formula (II).

The 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 addition in the precipitation step)] × 100 (Mass%) is a conditional expression for maintaining 15 to 18 mass%, the adhesion of the deposited PPE particles to the precipitation tank is small, the aggregation and scale of the PPE particles are difficult to occur, and the amount of solvent used and the particle size It shows an area where the balance between control and particle strength is good.
The “total mass of good solvent + poor solvent present in the precipitation tank after the addition in the precipitation step” is a total amount in a state where the inside of the precipitation tank is replaced with the additive solution composition.
That is, by satisfying the above formula (II) and setting the poor solvent ratio to be high, the good solvent is less likely to be impregnated in the PPE particles, and as a result, the fine solvent is not evenly aggregated and the residual solvent amount is small. PPE particles with a small amount of good solvent impregnation in the PPE particles can be obtained, and troubles such as scale adhesion can be effectively prevented.
Further, when the amount of good solvent impregnated is small, the PPE particles themselves become strong, and the change in the particle size of the PPE particles can be effectively prevented even in the post-treatment step after the precipitation step, and high-quality PPE particles are obtained.
When the ratio of the poor solvent exceeds the formula (II), the contact frequency between the poor solvent and the polymer increases, so that an increase in ultrafine particles can be predicted as follows. In addition, when the poor solvent ratio is lower than that of the formula (II), the adhesion of the surface of the precipitated particles is increased by the good solvent, aggregation occurs, and uniform small particles cannot be obtained.
Furthermore, the above formula (II) is satisfied, Y is set to (18.032 · (X / 100) ² -1.1873 · (X / 100) -0.3463) or more, and the poor solvent ratio on the liquid side and the poor solvent on the PPE particle side By setting the ratio higher and obtaining uniform PPE particles with a fine particle size, the effect of improving the drying property and reducing the amount of residual solvent can be obtained more reliably.
On the other hand, when the ratio of the poor solvent to the good solvent in the precipitation tank in the precipitation step exceeds the range of the above formula (II), the precipitation rate increases, so that the pulverization of the PPE particles proceeds. PPE particles having a high fine powder ratio cause a problem that in a drying process performed as a subsequent process of the precipitation process, the fluidity in the dryer is reduced and the amount of good solvent remaining in the PPE powder is increased. For this reason, in the manufacturing method of the PPE powder of this embodiment, said Y was prescribed | regulated to the range of Formula (II).

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

  The PPE residence time in the precipitation tank is preferably 0.25 to 5 minutes from the viewpoints of stable precipitation, particle size stability and scale prevention. 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 preferably includes a draft tube from the viewpoint of stable precipitation and particle size control. In this case, the draft tube has an inclined paddle blade and a screw blade from the viewpoint of stabilizing the flow state in the precipitation tank. And at least one stirring blade selected from the group consisting of ribbon blades, and the stirring blade in the draft tube is preferably a lower discharge blade. In the precipitation step described above, it is preferable to perform stirring using a stirring tank having 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 effect that the stirring operation state is stabilized is acquired.

  Moreover, as a precipitation tank used in a precipitation process, the thing provided with the stirring blade which is a ribbon blade | wing from the viewpoint of stabilizing the fluidity | liquidity in a precipitation tank outside the said draft tube is used preferably. The stirring blade, which is the ribbon blade on the outside of the draft tube, is preferably the upper discharge blade from the viewpoint of creating a flow in the same direction as the lower discharge blade provided in the draft tube and further stabilizing the fluidity, as described above. In the precipitation step, it is preferable to perform stirring with the stirring blade that is the upper discharge blade.

Since the particles of the PPE powder obtained by the precipitation process described above are strong, in order to make the particle size fine and uniform, a predetermined pulverizer is used to mechanically aggregate the PPE powder aggregates after the precipitation process. The particle size can be adjusted by crushing.
Since the PPE powder particles obtained by the PPE powder manufacturing method of the present embodiment are strong as described above, the precipitated particles can also be used in a slurry pump or a solid-liquid separator in a post-processing step such as a cleaning step described later. By crushing the particle size finely as described above without crushing to less than the size, the residual solvent amount can be obtained by the conventional PPE manufacturing technology even when performing drying treatment using various dryers. It can be significantly reduced compared to PPE particles.
As a result, the PPE powder after drying, when processed by an extruder or the like, has much less residual solvent volatilization, and there is no bridge in the solvent gas backflow or hopper. It will be excellent.

(Washing process)
In the manufacturing method of the PPE powder of this embodiment, you may perform the washing | cleaning process which adds a poor solvent to the PPE slurry obtained in the precipitation process mentioned above and stirs as needed, and wash | cleans a good solvent. .
Then, it isolate | separates into a solvent and wet PPE by a solid-liquid separation process. At that time, the process of solid-liquid separation while washing the wet PPE with a poor solvent may be repeated.
The apparatus for performing solid-liquid separation is not particularly limited, but is a centrifuge (vibration type, screw type, decanter type, basket type, etc.), vacuum filter (drum type filter, belt filter, rotary vacuum filter). , Young filter, Nutsche, etc.), filter press, and roll press can be used.

The wet PPE obtained after the solid-liquid separation may be pulverized by using a pulverizer, whereby the pulverized particle size can be pulverized.
In the method for producing PPE powder of the present embodiment, the mass ratio (Y) of the poor solvent and the good solvent when precipitating PPE in the precipitation step described above is within the range of the above formula (II). Thus, particle aggregation and pulverization can be effectively suppressed, and fine uniform particles can be obtained. The solid-liquid separation device used in the above-described solid-liquid separation step uses a centrifugal force or reduced pressure to drain the liquid. At that time, the PPE particles may become a soft lump. By crushing to a certain extent, the uniformity of particle size can be improved.
The pulverizer is not particularly limited, and for example, a jaw crusher, a cone crusher, a hammer mill, a feather mill, a ball mill, a high-speed rotating mill, a jet mill and the like can be used.

(Drying process)
In the manufacturing method of the PPE powder of this embodiment, it is preferable to perform a drying process after performing a precipitation process as mentioned above.
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 PPE powder is dried at a temperature of 60 ° C. or higher, the content of the good solvent in the PPE powder can be efficiently reduced.
In order to obtain dry PPE 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, etc. 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>
In the method for producing PPE powder of the present embodiment, the fine powder ratio (content ratio of particles of 5.02 μm or less) in the PPE powder after the drying step is preferably 10% by mass or less, more preferably It is 5 mass% or less, More preferably, it is 3 mass% or less.
When the fine powder ratio is 10% by mass or less, problems such as filter clogging can be suppressed when the PPE powder is air-fed, and the handleability is improved.
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 PPE powder obtained by the production method of the present embodiment is preferably 80 to 1000 μm, more preferably 90 to 800 μm, and still more preferably 95 to 500 μm, from the viewpoints of powder handleability and solvent solubility.
In addition, an average particle diameter can be measured by the method as described in the Example mentioned later.
<Reduced viscosity>
The PPE powder obtained by the production method of the present embodiment has a reduced viscosity measured at 30 ° C. using a chloroform solution in which 0.5 g of PPE is dissolved in 1 dL of chloroform within a range of 0.15 to 1.0 dL / g. Preferably, it is in the range of 0.20 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.
<Residual amount of good solvent>
The amount of residual good solvent in the PPE powder obtained by the production method of the present embodiment is preferably 1.5% by mass or less, more preferably 0.3% by mass or less, and 0.2% by mass or less. More preferably.
When the content of the good solvent is 1.5% by mass or less, an effect of not deteriorating the working environment at the time of post-treatment such as granulation and molding can be obtained.
The residual good solvent amount can be measured by the method described in Examples described later.
<Solvent solubility>
The PPE powder obtained by the production method of this embodiment has good solvent solubility. The PPE powder obtained by the production method of the present embodiment is adjusted so as to satisfy the above formula (II) in the precipitation step, and the poor solvent ratio in the precipitation tank is increased so that the good solvent is impregnated in the PPE particles. As a result, it is fine, uniform and difficult to agglomerate. Therefore, the solvent solubility is improved.

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 and fine powder ratio)
The PPE powders obtained in Examples and Comparative Examples described later were sieved using a micro type electromagnetic vibration sieve (M-2 type, manufactured by Tsutsui Rika Instruments Co., Ltd.), and the mass of each fractionation part 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 (mass%) of particles of 5.02 μm or less obtained from the cumulative curve of particle size distribution was calculated as the fine powder rate.

((2) Measurement of reduced viscosity)
A 0.5 g / dL chloroform solution of the PPE powder obtained in the examples and comparative examples described later is prepared, and the reduced viscosity (ηsp / c) [dL / g] at 30 ° C. is obtained using an Ubbelohde viscosity tube. It was.

((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 prepared with standard polystyrene, and the weight of PPE obtained in Examples and Comparative Examples described later using this calibration curve. The average molecular weight (Mw) and the number average molecular weight (Mn) were measured. Moreover, molecular weight distribution Mw / Mn (dispersion degree) was computed from these.
As the standard polystyrene, those having a molecular weight of 3650000, 217000, 1090000, 681000, 204000, 52000, 30200, 13800, 3360, 1300, and 550 were used.
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 PPE was prepared and used.
The UV wavelength of the detector was 254 nm for standard polystyrene and 283 nm for PPE.

((4) Comparison of solvent usage)
Comparing the amount of good solvent and poor solvent used for precipitating 1 kg of PPE (kg), and their total amount (including the amount of solvent used for washing after filtration) from the feed amount Went.

((5) Residual amount of toluene)
The amount of toluene in the PPE powder after drying was measured by gas chromatography.
As a pretreatment, a predetermined amount of PPE powder was dissolved in 10 times the amount of chloroform, the solution was directly injected into gas chromatography, and the amount of toluene (% by mass) in PPE was calculated from the peak area value.

((6) Evaluation of solvent solubility)
Into a 5 L polypropylene wide-mouth bottle, 2 kg of toluene was charged, 1 kg of PPE was added, and further 2 kg of toluene was added, and the lid of the bottle was closed.
Thereafter, the bottle was shaken up and down 15 times and then stirred and placed in a double action lab shaker (manufactured by ASONE) for 1 hour. The temperature was 50 ° C.
After 1 hour, visually confirm the solubility in the solvent. If PPE is completely dissolved, ○, if small amount remains (not completely dissolved-less than 50 during preparation), Δ, large amount X (50 or more) remained in the case.

((7) Evaluation of extruder supply stability)
Using PPE powder, general-purpose polystyrene (hereinafter also referred to as GPPS) and impact-resistant polystyrene (hereinafter also referred to as HIPS) obtained in Examples and Comparative Examples described later as raw materials, modified under the following conditions PPE composition pellets were produced.
As a manufacturing apparatus, a twin screw extruder “ZSK25” manufactured by Werner & Pfleiderer, Germany was used.
40 parts by mass of PPE powder and 30 parts by mass of GPPS pellets were supplied from the upstream inlet of the twin screw extruder, and 30 parts by mass of HIPS pellets were supplied from the middle inlet of the twin screw extruder.
A modified PPE resin composition pellet was produced by melt-kneading under conditions of a cylinder temperature of 300 ° C., a screw rotation speed of 200 rpm, and vacuum degassing−700 mmHg.
The supply stability of the PPE powder at the upstream inlet of the twin screw extruder was evaluated as follows.
○: The supplied PPE powder is stably bited into the screw.
Δ: The supplied PPE powder accumulates on the screw, and the operation can be continued, but unstable or unmelted, and the physical properties are not stable.
X: The supplied PPE powder is deposited on the screw, and the amount of deposition increases.
PPE powder does not fall from the hopper (bridge).
Inability to drive.
Unmelting occurs and extrusion is not stable.
Either.

[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 a uniform solution state. Dry air was passed through for 86 minutes to obtain a polymerization mixture. 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 PPE, and this was used as a polymer solution (3).
In the polymer (3), the addition amount of cupric oxide as a catalyst component was reduced to control the molecular weight.

[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 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 produce 60 kg of a polymer solution having a polymer concentration of 30.5% by mass.
Next, the polymer was deposited using a precipitation tank with a jacket provided with a draft tube described in Example 1 of International Publication No. 2003/064499 and four inclined paddle blades.
In addition, it was set as the precipitation tank which added and provided four baffles outside the draft tube.
The amount of liquid in the precipitation tank during this precipitation tank operation was 1100 mL.
The precipitation tank was charged with 500 g of toluene and 500 g of methanol, and stirred at 1500 rpm.
The precipitation tank was provided with an overflow line, and when the amount of the internal liquid exceeded 1100 mL, the internal liquid overflowed and was discharged outside the tank.
The position of the feed line was the same as the position described in Example 1 of International Publication No. 2003/064499.
350 g / min of methanol containing 3.0% by mass of water and 422 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 165 minutes.
The slurry liquid obtained by precipitating PPE was discharged from the precipitation tank at 772 g / min and fed to the washing tank by a slurry pump.
To the washing tank, methanol was fed from another line at 350 g / min, and the slurry in the slurry was stirred to replace and wash the toluene in the PPE particles.
A washing slurry liquid of 160 kg having a slurry concentration of 11.5% by mass was produced.
The slurry was divided every 10 kg and filtered through a basket centle (Tanabe Wiltech model 0-15).
After each filtration, 1.15 kg of methanol was sprayed onto the wet PPE in the basket centre and filtered again to obtain wet PPE.
Next, the wet PPE was held at 150 ° C. and 1 mmHg for 1.5 hours to obtain a dry PPE powder.
Each measurement was performed by the method mentioned above about the obtained PPE 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 produce 55 kg of a polymer solution having a polymer concentration of 38.0% by mass.
As a poor solvent fed to the precipitation tank and a polymer solution, methanol containing 3.0% by mass of water was 450 g / min, and the above 38.0% by mass polymer solution was 322 g / min. As a poor solvent fed to the washing tank, methanol was 250 g / min, and 170 kg of a slurry liquid having a polymer concentration of 12% by mass was produced. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE 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 produce 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 350 g / min, and the above 30.5% by mass polymer solution was fed into the tank at 422 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE 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 produce 55 kg of a polymer solution having a polymer concentration of 38.0% 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 450 g / min, and the above 38.0% by mass polymer solution was fed at 322 g / min. As a poor solvent fed to the washing tank, methanol was 250 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE 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 produce 60 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 350 g / min, and the above 30.5% by mass polymer solution was fed at 422 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE 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 produce 55 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 fed at 450 g / min, and the above 38.0% by mass polymer solution was fed at 322 g / min. As a poor solvent fed to the washing tank, methanol was 250 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE powder.
Table 1 shows the measurement results.

<Example 7>
The polymer solution (2) obtained in Production Example 2 was concentrated to 47.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to produce 50 kg of a polymer solution having a polymer concentration of 47.0% 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 510 g / min, and the above 47.0% by mass polymer solution was fed at 262 g / min. As a poor solvent fed to the cleaning layer, methanol was set at 450 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE 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 65 kg of a polymer solution having a polymer concentration of 22.0% by mass.
Next, the polymer was deposited using a precipitation tank with a jacket provided with a draft tube described in Example 1 of International Publication No. 2003/064499 and four inclined paddle blades. In addition, it was set as the precipitation tank which added and provided four baffles outside the draft tube.
The amount of liquid in the precipitation tank during this precipitation tank operation was 1100 mL.
The precipitation tank was charged with 500 g of toluene and 500 g of methanol, and stirred at 1500 rpm.
The precipitation tank was provided with an overflow line, and when the amount of the internal liquid exceeded 1100 mL, the internal liquid overflowed and was discharged outside the tank.
The position of the feed line was the same as the position described in Example 1 of International Publication No. 2003/064499.
370 g / min of methanol containing 3.0% by mass of water and 402 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 160 minutes.
The slurry liquid obtained by precipitating PPE 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 in a separate tank was fed at 350 g / min and stirred with the slurry liquid to replace and wash toluene in the PPE particles.
180 kg of a cleaning slurry liquid having a slurry concentration of 8.3 mass% was produced.
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, 0.83 kg of methanol was sprayed onto the wet PPE in the basket centre and filtered again to obtain wet PPE.
Next, the wet PPE was held at 150 ° C. and 1 mmHg for 1.5 hours to obtain a dry PPE powder.
Each measurement was performed by the method mentioned above about the obtained PPE 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 produce 50 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 fed at 480 g / min, and the above 38.0% by mass polymer solution was fed at 292 g / min. As a poor solvent fed to the washing tank, methanol was 250 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE 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 65 kg of a polymer solution having a polymer concentration of 22.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was fed at 370 g / min, and the above 22.0% by mass polymer solution was fed at 402 g / min. The paddle blade continued to run at 1500 rpm and operated continuously for about 160 minutes.
The slurry liquid obtained by precipitating PPE 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 in a separate tank was fed at 350 g / min and stirred with the slurry liquid to replace and wash toluene in the PPE particles. 180 kg of a cleaning slurry liquid having a slurry concentration of 8.3 mass% was produced.
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, 0.83 kg of methanol was sprayed onto the wet PPE in the basket centre and filtered again to obtain wet PPE.
Next, the wet PPE was held at 150 ° C. and 1 mmHg for 1.5 hours to obtain a dry PPE powder. Each measurement was performed by the method mentioned above about the obtained PPE 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 produce 50 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 fed at 370 g / min, and the above 38.0% by mass polymer solution was fed at 402 g / min. As a poor solvent fed to the washing tank, methanol was 250 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE 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 65 kg of a polymer solution having a polymer concentration of 22.0% by mass.
As the poor solvent fed to the precipitation tank and the polymer solution, methanol containing 3.0% by mass of water was fed at 240 g / min, and the 22.0% by mass polymer solution was fed at 402 g / min. The paddle blade continued to run at 1500 rpm and operated continuously for about 160 minutes.
The slurry liquid obtained by precipitating PPE 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 in a separate tank was fed at 350 g / min and stirred with the slurry liquid to replace and wash toluene in the PPE particles. A cleaning slurry liquid 180 kg having a slurry concentration of 8.3 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, 0.83 kg of methanol was sprayed onto the wet PPE in the basket centre and filtered again to obtain wet PPE.
Next, the wet PPE was held at 150 ° C. and 1 mmHg for 1.5 hours to obtain a dry PPE powder. Each measurement was performed by the method mentioned above about the obtained PPE 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 produce 50 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 fed at 480 g / min, and the above 38.0% by mass polymer solution was fed at 292 g / min. As a poor solvent fed to the washing tank, methanol was 250 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE powder.
The measurement results are shown in Table 2.

<Comparative Example 7>
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 produce 50 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 422 g / min, and the 30.5% by mass polymer solution was fed at 350 g / min. As a poor solvent fed to the washing tank, methanol was 550 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE powder.
The measurement results are shown in Table 2.

<Comparative Example 8>
The polymer solution (2) obtained in Production Example 2 was concentrated to 47.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to produce 50 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 fed at 550 g / min, and the 47.0% by mass polymer solution was fed at 222 g / min. As a poor solvent fed to the washing tank, methanol was set to 400 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE powder.
The measurement results are shown in Table 2.

<Comparative Example 9>
The polymer solution (2) obtained in Production Example 2 was concentrated to 40.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to produce 50 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 fed at 510 g / min, and the 40.0% by mass polymer solution was fed at 262 g / min. As a poor solvent fed to the washing tank, methanol was 450 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE powder.
The measurement results are shown in Table 2.

<Comparative Example 10>
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 produce 50 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 280 g / min, and the 30.5% by mass polymer solution was fed at 492 g / min. As a poor solvent fed to the washing tank, methanol was set to 400 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE powder.
The measurement results are shown in Table 2.

<Comparative Example 11>
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 produce 50 kg of a polymer solution having a polymer concentration of 38.0% 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 380 g / min, and the 38.0% by mass polymer solution was fed at 392 g / min. As a poor solvent fed to the washing tank, methanol was 350 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE powder.
The measurement results are shown in Table 2.

<Comparative Example 12>
The polymer solution (2) obtained in Production Example 2 was concentrated to 47.0% by mass by the same method as the concentration method described in Example 1.
This operation was repeated to produce 50 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 fed at 462 g / min, and the 47.0% by mass polymer solution was fed at 310 g / min. As a poor solvent fed to the washing tank, methanol was 350 g / min. Other conditions were the same as in Example 1.
Each measurement was performed by the method mentioned above about the obtained PPE powder.
The measurement results are shown in Table 2.

The symbols in Tables 1 and 2 are as follows.
Poor solvent = methanol + water Good solvent = toluene MA: methanol Tol: toluene PPE: polyphenylene ether Y1 = 22.430 · (X / 100) ² −1.4769 · (X / 100) −0.1868
Y2 = 18.032 ・ (X / 100) ² −1.1873 ・ (X / 100) −0.3463
In addition, let X [mass%] be the PPE density | concentration in the good solvent solution (polymer solution) of PPE added in the precipitation tank in the precipitation process.
Poor solvent / good solvent: Mass ratio based on the amount of good solvent in the polymer solution added to the precipitation tank in the precipitation step and the amount of poor solvent added to the precipitation tank.

As shown in Table 1, in Examples 1 to 7, where the ratio of poor solvent / good solvent is Y2 or more and Y1 or less, there is no large variation in particle diameter during the precipitation operation, and the scale of the precipitation tank is suppressed. The precipitation movement was performed stably. As a result, a PPE powder having excellent particle size uniformity and a low fine powder ratio was obtained, and the fine powder ratio of 5.02 μm or less could be reduced. Moreover, the amount of residual toluene was low, and it was possible to effectively prevent a decrease in drying efficiency due to powder adhesion in the dryer.
Moreover, Examples 1-7 whose said poor solvent / good solvent ratio is Y2 or more and Y1 become the thing with which the balance of solvent usage-amount, average particle diameter, and particle | grain intensity | strength (low powder ratio is low) was all excellent. It was.
In Comparative Examples 1, 3, and 5, since the poor solvent / good solvent ratio was too high and the deposition rate was fast, the fine powder rate was high, and the fluidity in the dryer was reduced, so the amount of residual toluene also increased. In addition, the amount of solvent was adjusted to stabilize the operation, but the amount of solvent used was significantly increased compared to the examples.
In Comparative Examples 2, 4, and 6, since the poor solvent / good solvent ratio was too high and the precipitation rate was fast, the fine powder rate was high, and the fluidity in the dryer decreased, so the amount of residual toluene also increased.
In Comparative Examples 7 to 9, since the poor solvent / good solvent ratio was too high and the precipitation rate was fast, the fine powder rate was high, and the fluidity in the dryer was lowered, so the amount of residual toluene was also increased. Even if it was fed to the extruder, it could not be stably fed.
In Comparative Examples 10 to 12, the poor solvent / good solvent ratio was too low, the PPE particles became swollen with toluene, and the amount of residual toluene also increased. Unmelted material was generated when fed to the extruder.

  The method for producing PPE powder of the present invention has industrial applicability as a production technique 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) of the poor solvent added to the precipitation tank and the good solvent in the polymer solution in the precipitation step is Y, the X and Y are represented by the following formula (I), A method for producing a polyphenylene ether powder that satisfies (II).
30 <X ≦ 48 (I)
18.032 ・ (X / 100) ² −1.1873 ・ (X / 100) −0.3463 ≦ Y ≦ 22.430 ・ (X / 100) ² −1.4769 ・ (X / 100) −0.1868 (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. 2. A method for producing a polyphenylene ether powder according to 2.   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 stirring blade selected from the group consisting of the inclined paddle blade, the screw blade, and the ribbon blade, and the stirring blade inside the draft tube 9. The method for producing polyphenylene ether powder according to claim 7, 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 on the outside of the draft tube is an upper discharge blade, and in the precipitation step, the outer surface of 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 that is a ribbon blade.   The manufacturing method of the polyphenylene ether powder as described in any one of Claims 1 thru | or 10 which sets the liquid temperature in the said precipitation process to 30-63 degreeC.   The method for producing a polyphenylene ether powder according to any one of claims 1 to 11, wherein a residence time of the polyphenylene ether in the precipitation tank is 0.25 to 5 minutes.