JP2018203968A - Process for producing polyphenylene ether powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a PPE powder having an appropriately large average particle size, an appropriately small fine powder ratio, and a reduced residue such as a solvent. SOLUTION: A polyphenylene ether having a good solvent content of 0.005% by mass or more and 1.5% by mass or less is used at a temperature of 150 ° C. or more and 210 ° C. or less, and a clearance between a stirring blade and a dryer container is 4 mm or more. A method for producing a polyphenylene ether powder, which comprises vacuum drying using a certain vacuum dryer. [Selection diagram] Fig. 1

Description

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

  Modified PPE resin made from polyphenylene ether (hereinafter sometimes referred to simply as PPE) can produce products / parts of a desired shape by molding methods such as the melt injection molding method and the melt extrusion molding method. Widely used as materials for products and parts in the fields of automobiles, automobiles, and other various industrial materials.

In general, in the industrial production of PPE, it is known that PPE is obtained in the form of particles having an average particle size of about 1 μm to 300 μm, and fine particles having a particle size of about 106 μm or less are generated.
These fine particles contribute to problems such as scattering of particles during transportation and poor biting of particles supplied from a hopper during extrusion molding.
Therefore, various investigations have been made on methods for industrially producing PPE having a large average particle diameter and a small number of fine particles.

In Patent Document 1, a PPE wetted with a good solvent and a poor solvent in the PPE production process contains 0.5% by mass or more and 100% by mass or less of water, and heated to a predetermined temperature to have a particle size of 106 μm or less. A method for producing PPE with a small proportion of particles is described.
Patent Document 2 describes a method for producing PPE having an average particle diameter of 50 to 300 μm by specifying a mass ratio of a monosubstituted aromatic hydrocarbon good solvent and other hydrocarbon good solvents.
Patent Document 3 describes a method of increasing the average particle size by granulating by drying PPE mixed with PPE wetted with a good solvent and a poor solvent during the PPE production process, and drying.
Patent Document 4 describes a production method in which PPE wetted with a good solvent and a poor solvent during the PPE production process is granulated by stirring in warm water at 40 to 90 ° C.
Patent Document 5 describes a method for producing PPE having a uniform average particle diameter and less residual solvent by compressing and solidifying a PPE resin after drying and then crushing.

JP 2009-221403 A JP 2011-099033 A JP 2006-241258 A JP 2001-310946 A JP 2001-072763 A

However, in the manufacturing method described in Patent Document 1, the residual good solvent cannot be reduced, and it is necessary to add a heating process to the manufacturing process and add a heating process, which complicates the manufacturing process. Production efficiency is poor.
Moreover, in the manufacturing method of patent document 2, since the several good solvent is used, the collection process of a solvent becomes complicated. In addition, since monosubstituted aromatic hydrocarbons having high affinity with PPE are used, a great deal of energy is required to remove residual good solvent.
In the production method described in Patent Document 3, a new process for adding and heating dried PPE to wet PPE is required, and energy for further heating the dried PPE is required, resulting in poor production efficiency.
In Patent Document 4, it is not described that the residual good solvent is reduced. In the production method described in this document, a process of re-slurrying wet PPE with warm water, heating and stirring, and solid-liquid separation is required. Production efficiency is poor.
Furthermore, in the manufacturing method described in Patent Document 5, the compression granulation and pulverization equipment is expensive, and it is necessary to recycle the fine powder generated during pulverization, and there is a concern that the color tone of PPE deteriorates due to the heat history.

  Many developments of methods for improving the particle size of PPE have been studied. It has long been a challenge to obtain PPE that can adjust the particle size of PPE to an optimum range and at the same time improve the odor during heat processing with residual solvent.

  The present invention has been made in view of the above problems, and an object of the present invention is to produce a PPE powder having an average particle size that is moderately large and a fine powder ratio that is moderately small, and a residue such as a solvent is reduced.

  As a result of extensive studies by the present inventors, it has been found that the PPE powder containing a small amount of residual good solvent is vacuum-dried while heating and stirring, whereby the particle size and odor during heat processing can be greatly improved.

That is, the present invention is as follows.
[1]
A vacuum dryer in which the content of a good solvent is 0.005% by mass or more and 1.5% by mass or less, and the clearance between the stirring blade and the dryer container is 4 mm or more at a temperature of 150 ° C. or more and 210 ° C. or less. A method for producing a polyphenylene ether powder, characterized by vacuum drying using
[2]
The method for producing a polyphenylene ether powder according to [1], wherein the good solvent is at least one selected from the group consisting of benzene, toluene, and xylene.
[3]
The production of polyphenylene ether powder according to [1] or [2], wherein in the vacuum drying, vacuum drying is performed while purging an inert gas of 10 vol% / min or less of the effective capacity of the vacuum dryer into the vacuum dryer. Method.

  According to the present invention, it is possible to produce a PPE powder having an average particle size that is moderately large and a fine powder rate that is moderately small, and a residue such as a solvent is reduced.

(A) is a perspective view which shows notionally an example of the vacuum dryer used with the manufacturing method of this embodiment. (B) is a perspective view which shows notionally another example of the vacuum dryer used with the manufacturing method of this embodiment. (A)-(c) is a figure which shows the clearance C in the specific example of the stirring type dryer which can be used with the manufacturing method of this embodiment. (A) is a sectional view when the dryer is cut along a plane along its axis, and (c) is a sectional view when the dryer is cut along a plane perpendicular to the axis.

  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.

  First, the polyphenylene ether (PPE) in this embodiment will be described.

  The PPE produced by the method for producing polyphenylene ether powder of the present embodiment is a homopolymer and / or copolymer having a repeating unit structure represented by the following formula (1).

前記式（１）中、Ｒ₁、Ｒ₂、Ｒ₃、及びＲ₄は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１〜７のアルキル基、フェニル基、ハロアルキル基、アミノアルキル基、炭化水素オキシ基、及び少なくとも２個の炭素原子がハロゲン原子と酸素原子とを隔てているハロ炭化水素オキシ基からなる群より選ばれるいずれかである。

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

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

In the formula (1), the alkyl group represented by R ₁ , R ₂ , R ₃ , and R ₄ is a linear or branched chain having preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. And an alkyl group in the form of, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl and the like. Methyl and ethyl are preferable, and methyl is more preferable.
In the formula (1), 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 a halogen atom (for example, fluorine atom, chlorine atom, bromine atom, etc.), an alkyl group having 1 to 6 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl). , Tert-butyl, pentyl, hexyl, etc.), aryl groups (eg, phenyl, naphthyl, etc.), alkenyl groups (eg, ethenyl, 1-propenyl, 2-propenyl, etc.), alkynyl groups (eg, ethynyl, 1-propynyl, etc.) 2-propynyl etc.), aralkyl groups (eg benzyl, phenethyl etc.), alkoxy groups (eg methoxy, ethoxy etc.) and the like.

[Production method of polyphenylene ether powder]
The polyphenylene ether powder production method of the present embodiment is a method of vacuum drying polyphenylene ether using a vacuum dryer having a clearance of 4 mm or more between the stirring blade and the dryer container at a temperature of 150 ° C. or higher and 210 ° C. or lower. It is characterized by doing.
Here, in this embodiment, it is important that the polyphenylene ether subjected to vacuum drying has a good solvent content of 0.005% by mass or more and 1.5% by mass or less.

In the manufacturing method of the present embodiment, PPE containing a certain amount of good solvent is vacuum dried under a suitable distance between the stirring blade and the dryer container in a suitable temperature environment. It is possible to produce a PPE powder having an average particle size that is moderately large and a fine powder rate that is moderately small, while reducing the amount of material.
And since PPE manufactured by the manufacturing method of this embodiment has an average particle size that is moderately large and a fine powder rate that is moderately small, it is excellent in handleability and has excellent extruder biting properties. Can be manufactured. In addition, since PPE produced by the production method of the present embodiment is sufficiently reduced in residues such as a solvent, it is possible to produce PPE powder with improved odor particularly during thermal processing.

  At this time, the method for preparing polyphenylene ether having a suitable good solvent content (0.005 mass% to 1.5 mass%) is not particularly limited, and any method may be used. Here, as a polymerization method of PPE, precipitation precipitation polymerization and solution polymerization described later may be used.

As a method for preparing the suitable polyphenylene ether, for example, in the case of precipitation polymerization,
A polymerization / precipitation step in which a phenol compound is oxidatively polymerized in a polymerization solution containing a good solvent and a poor solvent of polyphenylene ether and a catalyst to precipitate polyphenylene ether to obtain a slurry liquid containing polyphenylene ether particles;
A solid-liquid separation step of separating the slurry liquid into wet polyphenylene ether particles and filtrate;
And a pre-drying step of drying the wet polyphenylene ether particles after the solid-liquid separation step.

In addition, as a method for preparing the suitable polyphenylene ether, for example, in the case of solution polymerization,
A polymerization step in which a phenolic compound is oxidized and polymerized in a polymerization solution containing a polyphenylene ether good solvent and a catalyst to obtain a polyphenylene ether mixed solution;
A precipitation step of mixing a polyphenylene ether mixed solution and a poor solvent of polyphenylene ether to obtain a slurry liquid containing polyphenylene ether particles by precipitating polyphenylene ether;
A solid-liquid separation step of separating the slurry liquid into wet polyphenylene ether particles and filtrate;
And a pre-drying step of drying the wet polyphenylene ether particles after the solid-liquid separation step.

  The production of the PPE of this embodiment may be a continuous type or a batch type.

  Hereinafter, an example of the manufacturing method used in the manufacturing method of the PPE powder of this embodiment will be described.

  The details of oxidative polymerization of a phenol compound in an example production method will be described.

Examples of the phenol compound include o-cresol, 2,6-dimethylphenol, 2-ethylphenol, 2-methyl-6-ethylphenol, 2,6-diethylphenol, 2-n-propylphenol, and 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-fluorophenyl) phenol, 2-methyl -6-tolylphenol, 2,6-ditolylphenol, 2,5-dimethylphenol, 2,3,6-trimethylphenol, 2,5-diethylphenol, 2-methyl-5-ethylphenol, 2-ethyl- 5-methylphenol, 2-allyl-5-methylphenol, 2,5-diallylphenol, 2,3-diethyl-6-n-propylphenol, 2-methyl-5-chlorophenol, 2-methyl-5-bromo Phenol, 2-methyl-5-isopropylphenol, 2-methyl-5-n-propylphenol, 2-ethyl-5-bromophenol, 2-methyl-5-n-butylphenol, 2,5-di-n-propyl Phenol, 2-ethyl-5-chlorophenol, 2-methyl-5-phenylphenol, 2,5-diphenylphenol Diol, 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- Examples include n-butylphenol and 2,6-dimethyl-3-t-butylphenol.
Among the above-mentioned phenol compounds, 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-diphenylphenol, 2,3,6-trimethylphenol, 5-dimethylphenol is preferable, and 2,6-dimethylphenol and 2,3,6-trimethylphenol are more preferable.

  The said phenol compound may be used individually by 1 type, or may be used in combination of 2 or more type.

In one example of the production method, 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 include a method using a combination of 2,3,6-trimethylphenol and 2,5-dimethylphenol, a method using a combination of 2,6-dimethylphenol and 2,3,6-trimethylphenol, and the like. At this time, 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.

To the PPE polymerization reaction system, an alkali metal hydroxide, an alkaline earth metal hydroxide, an alkali metal alkoxide, magnesium sulfate, a neutral salt such as calcium chloride, 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. Examples of such a surfactant include trioctylmethylammonium chloride known by Aliquat 336 and CapRiqat (manufactured by Dojindo Laboratories). The amount used is preferably within a range not exceeding 0.1 mass% with respect to the total amount of the polymerization reaction raw material.

As a catalyst used in an example manufacturing method, a known catalyst system generally used for manufacturing PPE can be used.
Specific examples include, for example, a transition metal ion having redox ability and an amine compound capable of complexing with the metal ion. Specifically, a catalyst system comprising a copper compound and an amine, manganese Examples thereof include a catalyst system composed of a compound and an amine, and a catalyst system composed of a cobalt compound and an amine.
Since the polymerization reaction proceeds efficiently under some alkaline conditions, some alkali or further amine may be added to these systems.

As a suitable catalyst in the production method of an example, a catalyst containing a diamine compound represented by the following formula (2), a copper compound, and a halogen compound as a constituent component can be given.
By using such a catalyst, there is a tendency that the polymerization rate can be further increased and the polymerization time can be further shortened. In addition, the molecular weight after polymerization tends to be more easily adjusted by adjusting the catalyst amount, oxygen blowing amount, polymerization time and the like.

上記式（２）中、Ｒ₅、Ｒ₆、Ｒ₇及びＲ₈は、それぞれ独立して、水素原子、炭素数１〜６の直鎖状又は分岐鎖状のアルキル基からなる群から選ばれるいずれかを示す。但し、Ｒ₅、Ｒ₆、Ｒ₇及びＲ₈の全てが同時に水素ではないものとする。
Ｒ₉は、炭素数２〜５の直鎖状又は分岐鎖状のアルキレン基を示す。 Examples of the diamine compound constituting the catalyst component include those represented by the following formula (2).

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

Examples of the diamine compound represented by the above formula (2) include N, N, N ′, N′-tetramethylethylenediamine, N, N, N′-trimethylethylenediamine, N, N′-dimethylethylenediamine, and N, N. -Dimethylethylenediamine, N-methylethylenediamine, N, N, N ', N'-tetraethylethylenediamine, N, N, N'-triethylethylenediamine, N, N'-diethylethylenediamine, N, N-diethylethylenediamine, N-ethyl Ethylenediamine, N, N-dimethyl-N′-ethylethylenediamine, N, N′-dimethyl-N-ethylethylenediamine, Nn-propylethylenediamine, N, N′-di-n-propylethylenediamine, Ni-propyl Ethylenediamine, N, N'-di-i-propylethylenedi Min, Nn-butylethylenediamine, N, N′-di-n-butylethylenediamine, Ni-butylethylenediamine, N, N′-di-butylethylenediamine, Nt-butylethylenediamine, N, N ′ -Di-t-butylethylenediamine, N, N, N ', N'-tetramethyl-1,3-diaminopropane, N, N, N'-trimethyl-1,3-diaminopropane, N, N'-dimethyl -1,3-diaminopropane, N-methyl-1,3-diaminopropane, N, N, N ′, N′-tetramethyl-1,3-diamino-1-methylpropane, N, N, N ′, N′-tetramethyl-1,3-diamino-2-methylpropane, N, N, N ′, N′-tetramethyl-1,4-diaminobutane, N, N, N ′, N′-tetramethyl- 1,5-diaminopentane And the like.
Preferred diamine compounds are those in which, in the formula (2), the alkylene group (R ₉ ) connecting two nitrogen atoms has 2 or 3 carbon atoms.

  Although the usage-amount of these diamine compounds is not specifically limited, Usually, it is used in the range of 0.01 mol-10 mol with respect to 100 mol of phenol compounds to be used.

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

In addition, these copper compounds may be synthesized from an oxide (for example, cuprous oxide), carbonate, hydroxide or the like and a corresponding halogen or acid.
The copper compound can be synthesized, for example, by mixing cuprous oxide and a halogen compound (for example, a solution of hydrogen halide).
Here, examples of the halogen compound include hydrogen chloride, hydrogen bromide, hydrogen iodide, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, potassium iodide, tetramethylammonium chloride, bromide. Examples include tetramethylammonium iodide, 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.
Of these, preferred halogen compounds are an aqueous solution of hydrogen chloride and an aqueous solution of hydrogen bromide.
These halogen compounds may be used alone or in combination of two or more.
Although the usage-amount of a copper compound and a halogen compound is not specifically limited, It is preferable to make the molar amount of a halogen atom 2 times or more and 20 times or less with respect to the molar amount of a copper atom.
Moreover, as the usage-amount of a copper atom, it is preferable to set it as the range of 0.02-0.6 mol with respect to 100 mol of phenol compounds to be used.

  The other components constituting the polymerization catalyst will be described.

  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 a tertiary aliphatic amine containing an alicyclic tertiary amine.
Examples of the tertiary aliphatic amine include, but are not limited to, trimethylamine, triethylamine, tripropylamine, tributylamine, triisobutylamine, dimethylethylamine, dimethylpropylamine, allyldiethylamine, dimethyl-n- Examples include butylamine, diethylisopropylamine, N-methylcyclohexylamine and the like.
These tertiary aliphatic amines may be used alone or in combination of two or more.
Although the usage-amount of a tertiary monoamine compound is not specifically limited, 15 mol or less is preferable with respect to 100 mol of phenol compounds to superpose | polymerize.

A secondary aliphatic amine can be applied as the secondary monoamine compound.
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.
Examples of secondary monoamine compounds containing aromatics are not limited to the following, but include, for example, N-phenylmethanolamine, N-phenylethanolamine, N-phenylpropanolamine, N- (m-methylphenyl) ethanol. Amine, N- (p-methylphenyl) ethanolamine, N- (2 ′, 6′-dimethylphenyl) ethanolamine, N- (p-chlorophenyl) ethanolamine, N-ethylaniline, N-butylaniline, N— Examples thereof include methyl-2-methylaniline, N-methyl-2,6-dimethylaniline, diphenylamine and the like.
The secondary monoamine compounds described above may be used alone or in combination of two or more.
Although the usage-amount of a secondary monoamine compound is not specifically limited, 15 mol or less is suitable with respect to 100 mol of phenol compounds to superpose | polymerize.

  Hereinafter, it describes about the superposition | polymerization and precipitation process in the case of precipitation precipitation polymerization.

(Polymerization / precipitation process)
In this step, a phenol compound is oxidatively polymerized in a polymerization solution containing a good and poor solvent for polyphenylene ether and a catalyst to precipitate polyphenylene ether, thereby obtaining a slurry liquid containing polyphenylene ether particles.

In the production process of PPE, when precipitation precipitation polymerization is performed, the polymerization / precipitation step is divided into the following stages of polymerization initial stage, intermediate polymerization stage, and late polymerization stage.
Polymerization initial period: period from the start of introduction of the oxygen-containing gas to the start of observation of precipitation.
Middle period of polymerization: Period from the start of precipitation until the slurry is stabilized.
Late polymerization: Period until the slurry is stabilized and the polymerization is completed.
In each of the above stages, the time until the precipitation and the time until the slurry is stabilized differ depending on the amount of the good solvent, the monomer type, and the monomer concentration.

The precipitation state of the polymer can be visually observed as appropriate.
As an observation method, specifically, the polymer precipitation state is visually observed from a viewing window of a predetermined reactor, the polymerization solution is extracted from a sampling port into a transparent container such as glass, and the precipitation state is visually observed. A method is mentioned.
As a guideline for starting the visual observation of the polymer precipitation state, the polymerization conversion rate is preferably 80% or more, although it depends on the amount of the phenolic compound contained in the polymerization system and the amount of the good or poor solvent for PPE. More preferably, the time when the polymerization conversion rate reaches 70% or more, more preferably the time when the polymerization conversion rate reaches 50% or more.

  In the step of polymerizing and precipitating the PPE of this embodiment, after the precipitation is observed in the polymerization solvent, the polymerization is continued while maintaining the precipitation in the middle of the polymerization, and the polymerization reaction is terminated in the late polymerization. The form is preferred.

Upon completion of the polymerization reaction, a predetermined post-treatment step may be performed on the obtained polyphenylene ether.
The specific method of the post-treatment step is not particularly limited, but usually, catalyst deactivation such as acids such as hydrochloric acid and acetic acid, ethylenediaminetetraacetic acid (EDTA) and its salt, nitrilotriacetic acid and its salt, etc. The method of deactivating a catalyst by adding an agent to a reaction liquid is mentioned.
A method in which the polymerization solution is repeatedly washed with a washing solution containing a poor solvent for the purpose of removing the catalyst or the catalyst deactivator complex is also suitable.

  Hereinafter, the polymerization step and the precipitation step in the case of solution polymerization will be described.

(Polymerization process)
In this step, a phenol compound is oxidized and polymerized in a polymerization solution containing a good solvent for polyphenylene ether and a catalyst to obtain a polyphenylene ether mixed solution.

  When PPE is produced, solution polymerization is a polymerization method in which PPE is dissolved in a good solvent used for polymerization during polymerization and at the end of polymerization. When PPE is precipitated as the polymerization proceeds, the temperature is increased at the beginning of polymerization or in the middle of the polymerization, the amount of good solvent for the monomer is increased, the monomer is added during the polymerization, a polymerization solvent that does not precipitate is selected, etc. By performing the treatment, polymerization in a solution state can be completed.

Upon completion of the polymerization reaction, a predetermined post-treatment step may be performed on the obtained polyphenylene ether.
The specific method of the post-treatment step is not particularly limited, but usually, catalyst deactivation such as acids such as hydrochloric acid and acetic acid, ethylenediaminetetraacetic acid (EDTA) and its salt, nitrilotriacetic acid and its salt, etc. The method of deactivating a catalyst by adding an agent to a reaction liquid is mentioned.
A method in which the polymerization solution is repeatedly washed with a washing solution containing a poor solvent for the purpose of removing the catalyst or the catalyst deactivator complex is also suitable.

In the polymerization process of PPE of this embodiment, both precipitation precipitation polymerization and solution polymerization may be performed while supplying an oxygen-containing gas.
As the oxygen-containing gas, pure oxygen, oxygen and an inert gas such as nitrogen mixed at an arbitrary ratio, air, and further an air and an inert gas such as nitrogen or a rare gas at an arbitrary ratio. A mixture or the like can be used.

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

The good solvent for PPE used in the method for producing PPE powder of this embodiment refers to a solvent having a solubility of PPE at 20 ° C. (mass (g) of solute (PPE) dissolved in 100 g of solvent) of 1 or more. .
Although it does not specifically limit as a good solvent of PPE, Specifically, at least 1 type chosen from the group which consists of benzene, toluene, and xylene is preferable.

In the present invention, the poor solvent for PPE refers to a solvent having a solubility of PPE at 20 ° C. (mass (g) of solute (PPE) dissolved in 100 g of solvent) of less than 1.
Although it does not specifically limit as a specific example of a poor solvent, Alcohol, a ketone, and water are mentioned, Preferably it is C1-C10 alcohol.
Examples of such a poor solvent include methanol, ethanol, propanol, isopropanol, n-butanol, 2-butanol, pentanol, hexanol, ethylene glycol, acetone, methyl ethyl ketone, and water. Among these, more preferable poor solvents are methanol, ethanol, isopropanol, n-butanol, 2-butanol, acetone, methyl ethyl ketone, and water.
These poor solvents may be used alone or in combination of two or more.

(Precipitation process)
Next, in the precipitation step in the case of solution polymerization in an example manufacturing method, after the polymerization step by solution polymerization, a polyphenylene ether mixture is mixed with a poor solvent of polyphenylene ether to precipitate polyphenylene ether, thereby polyphenylene ether. A slurry liquid containing ether granules is obtained.

(Solid-liquid separation process)
In one example of the manufacturing method, the slurry liquid obtained through the polymerization / precipitation process or the polymerization process and the precipitation process is separated into wet polyphenylene ether particles and a filtrate.

  Equipment for solid-liquid separation includes centrifuges (vibration type, screw type, decanter type, basket type, etc.), vacuum filters (drum type filters, belt filters, rotary vacuum filters, Young filters, Nutsche, etc.), filter presses It is possible to use a roll press.

  In the case of solution polymerization in the production method of the above-described example, after the polymerization step, PPE is precipitated by adding a poor solvent to the polymerization solution after polymerization, and PPE is isolated by solid-liquid separation. In another production method, PPE can be isolated by, for example, drying the polymerization solution.

(Pre-drying process)
In an example manufacturing method, the wet polyphenylene ether particles after the solid-liquid separation step are dried.
The pre-drying step may be provided after pulverization or may be provided without being pulverized.

The drying treatment is performed at a temperature of at least 60 ° C., preferably 80 ° C. or higher, more preferably 120 ° C. or higher, further preferably 140 ° C. or higher, and even more preferably 150 ° C. or higher.
If the PPE is dried at 60 ° C. or lower, the content of the good solvent in the PPE may not be efficiently suppressed to less than 1.5% by mass.
In order to obtain PPE with a low good solvent content, 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, a method of flowing an inert gas, etc. are effective. .
The drying process preferably uses a mixer. Examples of the mixer include a stirring type, a rolling type, and a self-rotating type dryer. As a result, the processing amount can be increased and the productivity can be maintained high.
Specific examples include paddle type dryers, rotary dryers, SC processors, KID dryers, ribbon mixing dryers, rotary kilns, multi-fin processors, steam tube dryers, and the like. An SC processor is also preferred. According to these, it is possible to increase the drying speed and produce PPE with a low good solvent content.

From the viewpoint of reducing the vacuum drying treatment time, the content of residual volatile components in the polyphenylene ether before the vacuum drying step is preferably 1.5% by mass or less, based on 100% by mass of the polyphenylene ether subjected to vacuum drying, More preferably, it is 1.0 mass% or less.
The residual volatile matter refers to the amount of change in the mass of PPE before and after the operation when the polyphenylene ether before the vacuum drying step is vacuum-dried for 120 minutes under the conditions of a temperature of 180 ° C. and a pressure of 10 torr. .

The content of the residual good solvent in the polyphenylene ether before the vacuum drying step is 1.5% by mass or less, based on 100% by mass of the polyphenylene ether used for vacuum drying in order to prevent the PPE particles from sticking during the vacuum drying. Preferably, it is 1.0 mass% or less more preferably.
The residual good solvent can be measured by gas chromatography. Specifically, the residual good solvent is a value measured by a measurement method in Examples described later.

The average particle size of the polyphenylene ether before the vacuum drying step is preferably 1.0 to 3000 μm, more preferably 10 to 2000 μm, and still more preferably 100 to 1500 μm, from the viewpoint of suppressing loss of fine powder. is there.
In addition, let an average particle diameter be the value measured by the measuring method in the below-mentioned Example.

The fine powder ratio of polyphenylene ether before the vacuum drying step (content ratio of particles having a particle size of 106 μm or less) is preferably 30% by weight or less, more preferably 25% by weight or less from the viewpoint of suppressing loss of fine powder. More preferably, it is 20 mass% or less.
In addition, let a fine powder rate be the value measured by the measuring method in the below-mentioned Example.

(Vacuum drying process)
As described above, in the method for producing the polyphenylene ether powder of the present embodiment, the clearance between the stirring blade and the dryer container is 4 mm or more at a temperature of 150 ° C. or higher and 210 ° C. or lower in the polyphenylene ether after the predrying step. Vacuum dry using a vacuum dryer.
Hereinafter, this process is referred to as a vacuum drying process.

In the present embodiment, it is important that the polyphenylene ether (for example, powdery PPE) after the pre-drying step used in the vacuum drying step has a good solvent content of 0.005 to 1.5% by mass. is there.
The content of the good solvent is preferably from 0.005 to 1.5% by mass, more preferably from 0.01 to 1.0% by mass, and still more preferably from the viewpoint of obtaining a suitable fine powder ratio. 015 to 0.5% by mass.

In the vacuum drying process, a vacuum dryer (stirring dryer) in which a stirring blade is attached inside the dryer container may be used. From the viewpoint of increasing the processing amount and maintaining high productivity, May be used.
Specific examples of the mixer include paddle type dryers, rotary dryers, KID dryers, ribbon mixing dryers, rotary kilns, multi-fin processors, and nauter mixers that can be evacuated. A paddle-type dryer, a ribbon mixing dryer, and a nauter mixer are preferable because the speed can be increased and PPE with a low content of good solvent, a large average particle size, and a small fine powder rate can be easily obtained.

  Examples of the vacuum dryer (stirring dryer) include Hosokawa Micron's Nauta mixer, Okawara's ribocorn, Nara Machinery's paddle dryer, and the like.

FIG. 1A conceptually shows a perspective view of an example of a vacuum dryer used in the manufacturing method of the present embodiment. FIG.1 (b) is a perspective view which shows notionally another example of the vacuum dryer used with the manufacturing method of this embodiment.
In this embodiment, as shown in FIG. 1A, the vacuum dryer may be arranged so that its depth direction is along the vertical direction, and as shown in FIG. 1B. The depth direction may be arranged along the horizontal direction.

Here, in this embodiment, it is important that the clearance C between the stirring blade and the dryer container is 4 mm or more.
The clearance C between the stirring blade and the dryer container refers to the closest distance between the stirring blade and the side wall of the dryer container. More specifically, the clearance C between the radial tip of the stirring blade and the side wall of the dryer container. The closest distance to the inner surface.
The clearance C in the specific example of the stirring-type dryer which can be used with the manufacturing method of this embodiment to Fig.2 (a)-(c) is shown. (A) is a sectional view when the dryer is cut along a plane along its axis, and (c) is a sectional view when the dryer is cut along a plane perpendicular to the axis.
When the clearance C is 4 mm or more in the stirring dryer, an increase in the fine powder rate can be suppressed.

  The clearance C is more preferably 6 mm or more, and further preferably 8 mm or more. Moreover, although there is no restriction | limiting in particular in an upper limit, it is preferable that it is 200 mm or less from a viewpoint of stirring efficiency and scale adhesiveness.

  In this embodiment, it can further dry with a vacuum dryer, further reduce the content of the good solvent, and granulate PPE powder to improve the particle size.

It is important that the drying temperature in the vacuum drying step is in a temperature range of 150 ° C. to 210 ° C.
The drying temperature is the average temperature throughout the vacuum drying process.
The drying temperature is preferably 160 ° C. or higher and 210 ° C. or lower, more preferably 170 ° C. or higher and 210 ° C. or lower, and further preferably 180 ° C. or higher and 210 ° C. or lower.
When stirring-type vacuum drying of PPE is performed at 150 ° C. or less, the content of the good solvent in PPE may not be efficiently suppressed to 0.10% by mass or less, and granulation does not proceed sufficiently and There is a risk that the strength may be lowered.

  As time of a vacuum drying process, 5-480 minutes are preferable, More preferably, it is 10-360 minutes.

  The degree of vacuum in the vacuum process is preferably 1 to 200 torr, more preferably 2 to 150 torr.

  In order to obtain PPE with a low good solvent content, methods such as raising the drying temperature, raising the vacuum in the drying atmosphere, stirring during drying, and flowing a small amount of inert gas are effective. It is.

In the vacuum drying step, from the viewpoint of drying efficiency, it is preferable to perform vacuum drying while purging an inert gas of 10 vol% / min or less of the effective capacity of the vacuum dryer into the vacuum dryer.
In addition, the effective capacity | capacitance of a vacuum dryer means the capacity | capacitance of the area | region in which PPE powder under stirring is accommodated among vacuum dryers.
The inert gas purge rate is more preferably 8 vol% / min or less, and further preferably 5 vol% / min or less.
Examples of the inert gas to be used include rare gases such as helium, neon, and argon, nitrogen, carbon dioxide, and the like. Nitrogen is preferable from the viewpoint of cost and availability.

The content of residual volatiles in the polyphenylene ether powder obtained by the vacuum drying step is preferably 0.10% by mass or less, more preferably 0.08% by mass or less, from the viewpoint of the working environment during PPE powder processing. More preferably, it is 0.05 mass% or less, Most preferably, it is 0.01 mass% or less.
The residual volatile content is the amount of change in the mass of PPE before and after the operation when the polyphenylene ether powder after the vacuum drying step is vacuum-dried for 120 minutes at a temperature of 180 ° C. and a pressure of 10 torr. Say.

The content of the residual good solvent in the polyphenylene ether powder obtained by the vacuum drying step is preferably 0.10% by mass or less, more preferably 0.08% by mass or less, from the viewpoint of the working environment during PPE powder processing. More preferably, it is 0.05 mass% or less, Most preferably, it is 0.01 mass% or less.
The residual good solvent can be measured by gas chromatography. Specifically, the residual good solvent is a value measured by a measurement method in Examples described later.

The average particle size of the polyphenylene ether powder obtained by the vacuum drying step is preferably 100 to 3000 μm, more preferably 150 to 2500 μm, and still more preferably 200 to 2000 μm, from the viewpoint of powder handling properties. is there.
In addition, let an average particle diameter be the value measured by the measuring method in the below-mentioned Example.

The fine powder ratio (content ratio of particles having a particle size of 106 μm or less) of the polyphenylene ether powder obtained by the vacuum drying process is preferably 10% by mass or less, more preferably 5% by mass from the viewpoint of powder handling properties. % Or less, and more preferably 3% by mass or less.
In addition, let a fine powder rate be the value measured by the measuring method in the below-mentioned Example.

  The polyphenylene ether powder (PPE powder) produced by the method for producing the polyphenylene ether powder of the present embodiment includes a thermoplastic resin and a thermosetting resin, and further, conductivity, flame retardancy, impact resistance, and the like. For the purpose of imparting the above effect, it can be melt kneaded with an additive.

  Examples of the thermoplastic resin and the thermosetting resin include polyethylene, polypropylene, thermoplastic elastomer, polystyrene, acrylonitrile / styrene resin, acrylonitrile / butadiene / styrene resin, methacrylic resin, vinyl chloride, polyamide, polyacetal, ultrahigh molecular weight polyethylene, Polybutylene terephthalate, polymethylpentene, polycarbonate, polyphenylene sulfide, polyether ketone, liquid crystal polymer, polytetrafluoroethylene, polyetherimide, polyarylate, polysulfone, polyethersulfone, polyamideimide, phenol, urea, melamine, unsaturated Examples thereof include resins such as polyester, alkyd, epoxy, diallyl phthalate, and bismaleimide.

Examples of additives include thermoplastic elastomers, plasticizers, stabilizers, modifiers, ultraviolet absorbers, flame retardants, colorants, mold release agents, and fiber reinforcing agents such as glass fibers and carbon fibers, and glass beads. In addition, fillers such as calcium carbonate, talc and clay may be added. This can be done by adding additives.
Stabilizers and modifiers include phosphites, hindered phenols, sulfur-containing antioxidants, alkanolamines, acid amides, dithiocarbamic acid metal salts, inorganic sulfides, metal oxides, carboxylic anhydrides , Dienophile compounds such as styrene and stearyl acrylate, and epoxy group-containing compounds.
These additives may be used alone or in combination of two or more.

  As a method for mixing the components constituting the resin composition, for example, a solution blending and degassing method, an extruder, a heating roll, a Banbury mixer, a kneader, a Henschel mixer and the like can be used.

  EXAMPLES Hereinafter, although an Example and a comparative example with this are given and demonstrated concretely about this invention, this invention is not limited to a following example.

  First, measurement methods such as physical properties and characteristics applied to Examples and Comparative Examples are shown below.

<Quantification of residual volatile matter>
The PPE sample before vacuum drying and the PPE sample after vacuum drying are weighed and collected in an aluminum dish, and the sample is dried under reduced pressure for 5 hours under the conditions of 185 ° C. and 0.1 mmHg together with the aluminum dish. By reducing the mass of the PPE powder from the mass of the PPE powder before drying, the amount (mass%) of residual volatile content in the sample was quantified.

<Quantification of residual good solvent>
About the PPE sample before vacuum drying and the PPE sample after vacuum drying, polyphenylene ether after vacuum drying using Shimadzu Gas Chromatography with a capillary column (product name: HR-1) manufactured by Shinwa Kako Co., Ltd. The quantity (mass%) of toluene which is a good solvent contained therein was measured. As a pretreatment, a predetermined amount of polyphenylene ether powder was dissolved in 10 times the amount of chloroform, the solution was directly injected into gas chromatography, and the toluene concentration in the polyphenylene ether was calculated from the peak area value. As a detector, FID was used, and an internal standard calibration curve method using t-butylbenzene as an internal standard substance was used.

<Measurement of average particle diameter and fine powder ratio (106 μm or less)>
The PPE sample before vacuum drying and the PPE sample after vacuum drying were screened using a micro type electromagnetic vibration sieve M-100 manufactured by Tsutsui Rika Instruments Co., Ltd., and the mass of polyphenylene ether fractionated on each sieve was determined. It 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 (μm). Similarly, the content ratio of particles of 106 μm or less obtained from the cumulative curve of particle size distribution in the PPE powder was calculated as the fine powder ratio (% by mass).

  Next, raw materials and apparatuses used in Examples and Comparative Examples are shown below.

<Raw material PPE powder>
In the following examples and comparative examples, the raw material 1: S201A manufactured by PXS (reduced viscosity (ηsp / c): 0.52 dL / g, glass transition temperature: 210 ° C.) as a polyphenylene ether before vacuum drying; 2: Toluene was sprayed on the raw material 1, mixed with stirring, and the amount of residual volatile matter and the amount of residual good solvent were adjusted. Details of the raw material 1 and the raw material 2 are shown in Table 1.

<Vacuum drying apparatus 1>
An autoclave with a stirrer having an inner diameter of 200 mm and a height of 350 mm was attached to a lid with a vacuum meter, a thermometer sheath tube, and a vacuuming nozzle (see FIG. 1A).
The thermometer sheath tube was inserted until the tube tip was 200 mm below the lower end of the lid.
A tilted anchor paddle blade with an anchor height of 300 mm was attached to the agitator. By making the anchor inclined, powder near the wall surface is discharged upward.
The autoclave was immersed in a large oil bath so that the temperature could be adjusted.

<Vacuum drying apparatus 2>
A single paddle dryer (SPD-3 (VS)) manufactured by Nara Machinery was used (see FIG. 1B).

[Example 1]
An inclined anchor paddle blade having a paddle outer diameter of 170 mm was attached to the agitator of the vacuum drying apparatus 1.
The vacuum drying apparatus 1 was charged with 3.5 kg of the PPE powder of the raw material 1, and after sealing, the pressure was reduced by a vacuum pump until the inside of the vacuum drying apparatus 1 reached 100 torr while stirring at 10 rpm. Then, when the setting of the oil bath was set to 175 ° C., the temperature in the vacuum drying apparatus 1 was stabilized in the range of 168 to 170 ° C. after 22 minutes, and averaged to 169 ° C. This state was continued for 360 minutes and the operation was terminated. The internal temperature of the vacuum drying apparatus 1 was cooled to 40 ° C. or less, a sample was taken, and the amount of residual volatile matter, the amount of residual good solvent, the average particle size, and the fine powder rate were measured.
The results are shown in Table 1.

[Example 2]
A nitrogen blowing nozzle was attached to the vacuum dryer 1, and 7.14 vol% / min of nitrogen was purged during the vacuum drying, and the same procedure as in Example 1 was performed except that the inside of the vacuum dryer 1 was 105 torr. The results are shown in Table 1.

[Comparative Example 1]
The operation was performed in the same manner as in Example 1 except that the paddle outer diameter of the inclined anchor paddle blade was 193 mm and the clearance was 3.5 mm. The results are shown in Table 1.

[Comparative Example 2]
The same operation as in Example 1 was performed except that the set temperature of the oil bath was 120 ° C. and the temperature in the vacuum drying apparatus 1 at the time of stability was 116 ° C. The results are shown in Table 1.

[Comparative Example 3]
The oil bath was set to 145 ° C., and after 14 minutes the temperature in the vacuum drying apparatus 1 was stabilized at 139 to 141 ° C. (average 140 ° C.), and this state was maintained for 20 minutes. Carried out. The results are shown in Table 1.

[Comparative Example 4]
The same operation as in Example 1 was performed except that the vacuum drying apparatus 1 was not evacuated. The results are shown in Table 1.

Example 3
The vacuum drying apparatus 2 was charged with 50 kg of PPE powder of the raw material 1. The clearance between the paddle of the vacuum drying apparatus 2 and the apparatus body was about 20 mm. While stirring the paddle at a rotational speed of 22 rpm, the vacuum dryer 2 was depressurized to 100 torr with a vacuum pump. Subsequently, 180 ° C. steam was passed through the jacket and heated. The temperature of the PPE powder was stabilized at 170 ° C. 45 minutes after the start of heating. The operation was continued until 360 minutes after the start of heating, and the steaming of the jacket was stopped. When the temperature of the PPE powder was lowered to 40 ° C. or lower, the vacuum drying apparatus 2 was opened, a sample was taken, and the amount of residual volatile matter, the amount of residual good solvent, the average particle size, and the fine particle ratio were measured.

Example 4
The same operation as in Example 1 was performed except that the set temperature of the oil bath was 210 ° C. At 37 minutes after the start of heating, the temperature of the PPE powder stabilized in the range of 203 to 207 ° C, and averaged 205 ° C.

Example 5
The same operation as in Example 4 was performed except that raw material 2 was used. Forty minutes after the start of heating, the temperature of the PPE powder stabilized in the range of 203 to 207 ° C, and averaged 205 ° C.
The results are shown in Table 1.

Example 6
The operation was performed in the same manner as in Example 1 except that the paddle outer diameter of the inclined anchor paddle blade was 191 mm and the clearance was 4.5 mm. The results are shown in Table 1.

  According to the present invention, it is possible to produce a PPE powder having an average particle size that is moderately large and a fine powder rate that is moderately small, and a residue such as a solvent is reduced.

Claims (3)

  A vacuum dryer in which the content of a good solvent is 0.005% by mass or more and 1.5% by mass or less, and the clearance between the stirring blade and the dryer container is 4 mm or more at a temperature of 150 ° C. or more and 210 ° C. or less. A method for producing a polyphenylene ether powder, characterized by vacuum drying using   The method for producing a polyphenylene ether powder according to claim 1, wherein the good solvent is at least one selected from the group consisting of benzene, toluene, and xylene.   The method for producing a polyphenylene ether powder according to claim 1 or 2, wherein in the vacuum drying, vacuum drying is performed while purging an inert gas of 10 vol% / min or less of the effective capacity of the vacuum dryer into the vacuum dryer.

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