JP4288435B2 - Method for producing polyphenylene ether resin - Google Patents

Description

（式中、Ｒ₁ 、Ｒ₂ 、Ｒ₃ 及びＲ₄ は、各々独立に水素、アルキル基、置換アルキル基、ハロゲン基、アリール基、置換アリール基、フェニル基又は置換フェニル基である。）
【００１０】
代表的なポリフェニレンエーテルは、ポリ（２，６−ジメチル−１，４−フェニレン）エーテル、ポリ（２−メチル−６−エチル−１，４−フェニレン）エーテル、ポリ（２，６−ジエチル−１，４−フェニレン）エーテル、ポリ（２−エチル−６−ｎ−プロピル−１，４−フェニレン）エーテル、ポリ（２，６−ジ−ｎ−プロピル−１，４−フェニレン）エーテル、ポリ（２−メチル−６−ｎ−ブチル−１，４−フェニレン）エーテル、ポリ（２−エチル−６−イソプロピル−１，４−フェニレン）エーテル、ポリ（２−メチル−６−クロロエチル−１，４−フェニレン）エーテル、ポリ（２−メチル−６−ヒドロキシエチル−１，４−フェニレン）エーテル等のホモポリマー、また２，６−ジメチルフェノールに共重合体成分として２，３，６−トリメチルフェノールおよびｏ−クレゾールの１種あるいは両方を組み合わせたポリフェニレンエーテル共重合体等が挙げられる。
【００１１】
また、本発明のポリフェニレンエーテルには、本発明の主旨に反さない限り、従来ポリフェニレンエーテルに存在させてもよいことが提案されている他の種々のフェニレンエーテルユニットを部分構造として含んでいてもよい。例えば、特開平１−２９７４２８号公報及び特開昭６３−３０１２２２号公報に記載の２−（ジアルキルアミノメチル）−６−メチルフェニレンエーテルユニットや、２−（Ｎ−アルキル−Ｎ−フェニルアミノメチル）−６−メチルフェニレンエーテルユニット等や、ポリフェニレンエーテル樹脂の主鎖中にジフェノキノン等が少量結合したものが挙げられる。さらに、炭素−炭素二重構造を持つ化合物により変性されたポリフェニレンエーテル（例えば特開平２−２７６８２３号公報、特開昭６３−１０８０５９号公報、特開昭５９−５９７２４号公報）も含むことができる。
【００１２】
本発明に用いるポリフェニレンエーテル樹脂の分子量は３０℃クロロホルム中の固有粘度が０．１〜０．７であるのが好ましく、０．２〜０．６の範囲にあるポリフェニレンエーテルが本発明の効果が顕著であり、特に好ましい。
【００１３】
本発明のポリフェニレンエーテルは、例えば、特公昭４２−３１９５号公報、特公昭４５−２３５５５号公報、特開昭６４−３３１３１号公報等に例示されるように、フェノール化合物を金属の塩と各種アミンとの組み合わせからなる触媒を用いて酸化重合される。重合溶媒は、例えばポリフェニレンエーテルの良溶媒であるベンゼン、トルエン、キシレン等の芳香族炭化水素、ジクロロメタン、クロロホルム、ジクロルベンゼン等のハロゲン化炭化水素、ニトロベンゼン等のニトロ化合物等が挙げられる。また、前記の良溶媒にポリフェニレンエーテルの非溶媒であるメタノール、エタノール等のアルコール類、ヘキサン、ヘプタン等の脂肪族炭化水素類、アセトン、メチルエチルケトン等のケトン類、酢酸エチル等のエステル類、ジメチルホルムアミド等のアミド類等を任意の割合および組成で混合し重合溶媒として用いることができる。重合溶媒中の非溶媒の割合が多くなると重合中にポリフェニレンエーテルが析出してくる沈澱重合となるが、本発明では重合後にポリフェニレンエーテルが析出しない溶液重合が溶液の移送や反応停止工程あるいは触媒分離工程等におけるハンドリングの点で好ましい。
【００１４】
本発明におけるポリフェニレンエーテル重合反応液中のポリフェニレンエーテルの濃度は、通常５〜７０重量％、好ましくは１０〜５０重量％の範囲である。また、溶液中にはポリフェニレンエーテルのほかに重合触媒や、触媒除去のための薬品、副生成物除去のための薬品等が含まれていてもかまわない。
【００１５】
このポリフェニレンエーテル重合反応液からポリフェニレンエーテルを析出させる方法としては、溶液にメタノール等のポリフェニレンエーテルに対する非溶媒を添加してポリフェニレンエーテルの粒子を析出させる方法が知られている。また、非溶媒として水とアルコール類の混合物を使用する方法（特公昭６０−２３６９６）等がある。本発明におけるポリフェニレンエーテル重合反応液からの、ポリフェニレンエーテルの析出・沈殿化は、ポリフェニレンエーテルに対して非溶媒であるアルコール類等にポリフェニレンエーテル反応液を連続的に添加し析出させる方法、または非溶媒と水との混合物中にポリフェニレンエーテル反応液を添加する方法のどちらでもかまわない。またその際、非溶媒重量／良溶媒重量比が０．５〜２．０とすることが好ましい。また，重合反応液を供給する際には往復動式攪拌機を備えた攪拌槽１段もしくは２段以上の槽中に、連続的にポリフェニレンエーテルを析出させるのが好ましい。
【００１６】
本発明において析出・沈殿化されたポリフェニレンエーテル粒子を固液分離する際，通常の遠心力を利用した方法、減圧による真空濾過法、またこれに限らずいずれの方法においてもかまわない。好ましくは分離した際のポリフェニレン湿潤固体の硬い塊のできにくい真空ろ過法が好ましい。
【００１７】
本発明において、ポリフェニレンエーテル湿潤固体は、１段もしくは２段以上の攪拌槽に連続または、バッチ式で供給され、水と混合され水分散液とされる。この際の攪拌機は、同方向あるいは往復回転いずれでもかまわない。この水分散液は攪拌機付き、かつ湿式粉砕機を通る循環経路付きの加温槽１段もしくは２段以上の槽中において、水と連続的にあるはバッチで混合される。
【００１８】
また、水とポリフェニレンエーテル水分散液の一部は湿式粉砕機を経由して槽内を循環する。湿式粉砕機は溶液内の固形成分を粉砕できる構造のものが良く、例えば、相川鉄工（株）製のゴラトール（商品名）や小松ゼノア（株）製のディスインテグレーター（商品名）等の構造を持つものが好ましい。
【００１９】
水／ポリフェニレンエーテル湿潤固体比は１〜１００の範囲でおこなわれるが、好ましくは２〜１０の範囲でおこなわれる。温度は４０〜１００℃でおこなわれ、加熱処理により系外に運ばれる水および有機溶媒は凝集操作によりそれぞれ系内循環および系外回収される。また系内は不活性ガス雰囲気で行うのが好ましいが、酸素存在下で処理することも可能である。不活性ガスは一般に、窒素、アルゴン、ヘリウム等が使用される。槽内の滞留時間は１〜１２０分必要で、造粒されたポリフェニレンエーテルは連続あるいはバッチで固液分離される。
【００２０】
本発明方法によれば、乾燥後の固形化ポリフェニレンエーテル樹脂の平均粒径が０．２〜２ｍｍ、嵩比重が０．３〜０．６ｇ／ｃｃのものが得られるため、押出機によって溶融混練してペレット化する際に、食い込み不良とか未溶融部分が残るなどのトラブルなく、成形材料として好適に使用することが可能である。
【００２１】
【実施例】
以下に、具体例により本発明を説明するがこれに限定される物ではなく、これらは本発明の範囲内で適当に改変することができる。
【００２２】
以下の操作にて得られたポリフェニレンエーテル粒子は窒素を５Ｎｍ³ ／ｈで流しながら１３５〜１４０℃で６時間以上乾燥して、ポリフェニレンエーテルの乾粉を得、乾粉粒子の粒度分布、平均粒径及び１００μｍ以下の粒子の割合を測定した。粒度分布及び１４０メッシュパスの１０６μｍ以下粒子の割合は、ＪＩＳ規格（ＪＩＳ Ｚ８８０１）に準じて行った。１０、１８．５、６０、１２０、１４０、２８０メッシュの篩を用い、ＴＮＫ篩振動機（タナカ化学機器社製）を用いて１０分間振動し篩をかけることで測定した。また、平均粒径は、５０％重量平均径により求めた。
【００２３】
押出機による押出試験は、池貝鉄工（株）製２軸押出機（ＰＣＭ−３０）を用い、乾燥後のポリフェニレンエーテル粉体４０重量部とスチレン系樹脂（電気化学工業（株）製、商品名HI-UM-301 ）６０重量部をミキサーでよく混合した後、溶融混練しストランドを切断してペレット状の樹脂組成物のペレットを得た。押出機のストランド中に発生するの不完全溶融のポリフェニレンエーテル樹脂を目視で観察し混練不良を判定した。
【００２４】
参考例１
臭化第二銅２ｋｇをジブチルアミン３５ｋｇ及びトルエン８００ｋｇに溶解させた。この触媒溶液に、２，６−ジメチルフェノール２００ｋｇをトルエン５００ｋｇに溶かした溶液を加えた。これらの混合液を反応機内にて、酸素を供給しながら４０℃で重合を３時間行った。反応停止後、水と接触させて反応液から触媒を除去し、ポリフェニレンエーテル重合反応液を得た。このポリフェニレンエーテル反応液をメタノールに添加し攪拌しながら析出・沈殿化させた。その後、固液分離機にて液を分離し、湿潤個体を得た。この湿潤固体中の含液率は６０wt％であった。またこの湿潤固体中には１０６μ以下の粒子が７７wt％含まれていた。
【００２５】
実施例１
参考例１記載の方法にて得られる湿潤固体１００ｋｇに水を添加して水分散液を得た。この水分散液を攪拌しながら８０℃の温水中に添加した。この時ポリフェニレンエーテル湿潤固体／水の重量比は０．０１であった。この水分散液を加温しつつ溶媒であるトルエン、メタノールを留去しながら、この液を湿式粉砕機（商品名：ゴラトール）に全水分散液の２０倍／時間の量で循環して湿式粉砕し、この溶媒の留去を１時間行った後、水分散液を抜き出した。この液を固液分離しポリフェニレンエーテル湿潤固体を得た。この湿潤固体を１４０℃，窒素気流下にて６時間乾燥した。こうして得られた粉体の粒度を振動篩を用いて測定した。平均粒径は０．２１ｍｍ、嵩比重は０．３４ｇ／ｃｃであった。押し出し機試験をおこなったところ混練不良は認められなかった。
【００２６】
実施例２
ポリフェニレンエーテル湿潤固体／水の重量比を０．５にし、湿式粉砕機に全水分散液の０．１倍／時間の量で循環すること以外は実施例１と同様にし、ポリフェニレンエーテル粉体を得た。得られた粉体の粒度を測定したところ、平均粒径は０．４１ｍｍ、嵩比重は０．３３ｇ／ｃｃであった。押し出し機試験をおこなったところ混練不良は認められなかった。
【００２７】
実施例３
ポリフェニレンエーテル湿潤固体／水の重量比を０．５にし、湿式粉砕機に全水分散液の４０倍／時間の量で循環すること以外は実施例１と同様にし、ポリフェニレンエーテル粉体を得た。得られた粉体の粒度を測定したところ、平均粒径は０．２４ｍｍ、嵩比重は０．３７ｇ／ｃｃであった。押し出し機試験をおこなったところ混練不良は認められなかった。
【００２８】
実施例４
ポリフェニレンエーテル湿潤固体／水の重量比を０．５にし、湿式粉砕機に全水分散液の２０倍／時間の量で循環すること以外は実施例１と同様にし、ポリフェニレンエーテル粉体を得た。得られた粉体の粒度を測定したところ、平均粒径は０．６６ｍｍ、嵩比重は０．３９ｇ／ｃｃであった。押し出し機試験をおこなったところ押し出し異常は認められなかった。
【００２９】
比較例１
ポリフェニレンエーテル湿潤固体／水の重量比を０．５にし、水分散液を湿式粉砕機に循環しない以外は実施例１と同様にし、ポリフェニレンエーテル粉体を得た。得られた粉体の粒度を測定したところ、ポリフェニレンエーテル粉体の粒径は９０重量％以上が１０メッシュ以上であり、嵩比重は０．２８ｇ／ｃｃであった。押し出し機試験をおこなったところ混練不良が認められた。
【００３０】
比較例２
ポリフェニレンエーテル湿潤固体／水の重量比を７．０にし、湿式粉砕機に全水分散液の０．１倍／時間の量で循環すること以外は実施例１と同様にした。この場合、循環することが可能な水分散液を得ることはできず、ポリフェニレンエーテル粉体は得られなかった。
【００３１】
比較例３
ポリフェニレンエーテル湿潤固体／水の重量比を０．０１にし、湿式粉砕機に全水分散液の０．１倍／時間の量で循環すること以外は実施例１と同様にした。得られた粉体の粒度を測定したところ、ポリフェニレンエーテル粉体の粒径は９０重量％以上が１０メッシュ以上であり、嵩比重は０．２９ｇ／ｃｃであった。押し出し機試験をおこなったところ混練不良が認められた。
【００３２】
【発明の効果】
本発明によれば、ポリフェニレンエーテルの重合反応液を、必要に応じてポリフェニレンエーテルに対して非溶媒、またはその水溶液を加えて沈殿体を形成させた後、固液分離し、分離された湿潤固体に水を加えて水分散液を形成し、加温することにより脱溶媒して造粒する工程において、水分散液の少なくとも一部を湿式粉砕機に循環し、必要以上に大きくなった粗大粒子を、粉砕することにより、平均粒径のそろったポリフェニレンエーテル粒子を造粒できる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the production of polyphenylene ether having a small amount of fine particles in which fine particles of polyphenylene ether or modified polyphenylene ether are sized within an average particle size of 0.2 to 2 mm.
[0002]
[Prior art]
In general, polyphenylene ether is obtained by using one or two or more phenol compounds in the presence of a complex catalyst containing copper, manganese, or cobalt using an aromatic hydrocarbon solvent or a mixed solvent of an aromatic hydrocarbon and an alcohol. Obtained by oxidative polymerization. Thereafter, a catalyst that is an impurity that impairs the characteristics of polyphenylene ether, and a method in which a polymerization terminator or a polymerization terminator and a reducing agent are brought into contact with each other and washed with a large amount of alcohol to remove byproducts. ing.
[0003]
However, since the conventional method uses a large amount of alcohol, it leads to an increase in the alcohol recovery cost. Further, the polyphenylene ether particles obtained in this way are remarkably fine or contain a large amount of fine particles. Problems such as particle scattering occurred, and problems such as poor supply from the hopper during molding or poor biting of the extruder occurred.
[0004]
Various studies have been conducted to solve these problems. As a method for improving the particle shape of polyphenylene ether, there is a method in which when a non-solvent such as alcohol is added to a polymer solution, water is allowed to coexist to suppress the formation of fine particles (Japanese Patent Laid-Open No. 54-146896). However, the particles formed by this method are not completely free of particles, and the particles formed by this method are relatively brittle and are fine in the transport process using a slurry pump and the solid-liquid separation process using a centrifuge. There were inconveniences such as a tendency to granulate.
[0005]
In addition, a method (USP-4263426) in which a polyphenylene ether solution is dispersed in water and granulated without using a non-solvent (USP-4263426) has been performed. It becomes very difficult to handle.
[0006]
Further, the examination of increasing the particle size at the time of granulation includes granulation method (Japanese Examined Patent Publication No. 45-587, Japanese Examined Patent Publication No. 60-23696), fine particle size increasing method (Japanese Examined Patent Publication No. Sho 55-17775, Japanese Patent Publication No. Sho 63-63). 243129), examination of particle size increasing aids (JP-A-62-172022) and the like. However, the method proposed above requires addition of the non-solvent of the polyphenylene ether resin as quickly as possible, is difficult and cumbersome to operate, and solves all the problems mentioned above. Was insufficient.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for producing a polyphenylene ether resin efficiently from a polyphenylene ether solution and having few fine particles by overcoming the drawbacks of the prior art.
[0008]
[Means for Solving the Problems]
In the present invention, a polyphenylene ether polymerization reaction liquid is added with a non-solvent or an aqueous solution thereof to polyphenylene ether as necessary to form a precipitate, followed by solid-liquid separation, and water is added to the separated wet solid. Is added to form a water dispersion, and when the solvent is removed by granulation by heating, at least a part of the water dispersion is circulated to a wet pulverizer to pulverize coarse particles that are larger than necessary. This is a method for producing a polyphenylene ether resin.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The polyphenylene ether in the present invention is derived from the compound represented by the general formula (1) by oxidative polymerization.
[Chemical 1]

(Wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen, an alkyl group, a substituted alkyl group, a halogen group, an aryl group, a substituted aryl group, a phenyl group or a substituted phenyl group.)
[0010]
Representative polyphenylene ethers include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2,6-diethyl-1). , 4-phenylene) ether, poly (2-ethyl-6-n-propyl-1,4-phenylene) ether, poly (2,6-di-n-propyl-1,4-phenylene) ether, poly (2 -Methyl-6-n-butyl-1,4-phenylene) ether, poly (2-ethyl-6-isopropyl-1,4-phenylene) ether, poly (2-methyl-6-chloroethyl-1,4-phenylene) ) Ether, poly (2-methyl-6-hydroxyethyl-1,4-phenylene) ether and other homopolymers, and 2,6-dimethylphenol as a copolymer component , 6-trimethylphenol and o- polyphenylene ether copolymers such as a combination of one or both of cresol.
[0011]
In addition, the polyphenylene ether of the present invention may include other various phenylene ether units that have been proposed to be present in the polyphenylene ether as a partial structure, unless they are contrary to the gist of the present invention. Good. For example, 2- (dialkylaminomethyl) -6-methylphenylene ether unit described in JP-A-1-297428 and JP-A-63-301222, and 2- (N-alkyl-N-phenylaminomethyl) Examples include -6-methyl phenylene ether unit or the like, or a small amount of diphenoquinone or the like bonded to the main chain of polyphenylene ether resin. Further, polyphenylene ethers modified with a compound having a carbon-carbon double structure (for example, JP-A-2-276823, JP-A-63-108059, JP-A-59-59724) can also be included. .
[0012]
The molecular weight of the polyphenylene ether resin used in the present invention is preferably such that the intrinsic viscosity in chloroform at 30 ° C. is 0.1 to 0.7, and polyphenylene ether in the range of 0.2 to 0.6 is effective for the present invention. It is remarkable and particularly preferred.
[0013]
The polyphenylene ether of the present invention includes phenol compounds such as metal salts and various amines as exemplified in JP-B-42-3195, JP-B-45-23555, and JP-A-64-33131. Oxidative polymerization is carried out using a catalyst comprising a combination of Examples of the polymerization solvent include aromatic hydrocarbons such as benzene, toluene and xylene, which are good solvents for polyphenylene ether, halogenated hydrocarbons such as dichloromethane, chloroform and dichlorobenzene, and nitro compounds such as nitrobenzene. In addition, the good solvent includes alcohols such as methanol and ethanol which are non-solvents of polyphenylene ether, aliphatic hydrocarbons such as hexane and heptane, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, dimethylformamide Etc. can be mixed in an arbitrary ratio and composition and used as a polymerization solvent. When the proportion of the non-solvent in the polymerization solvent increases, precipitation polymerization in which polyphenylene ether precipitates during the polymerization occurs. In the present invention, however, solution polymerization in which polyphenylene ether does not precipitate after polymerization is a solution transfer, reaction stop process or catalyst separation. It is preferable in terms of handling in the process.
[0014]
The concentration of polyphenylene ether in the polyphenylene ether polymerization reaction solution in the present invention is usually in the range of 5 to 70% by weight, preferably 10 to 50% by weight. In addition to polyphenylene ether, the solution may contain a polymerization catalyst, a chemical for removing the catalyst, a chemical for removing the by-product, and the like.
[0015]
As a method of precipitating polyphenylene ether from this polyphenylene ether polymerization reaction solution, a method of precipitating polyphenylene ether particles by adding a non-solvent for polyphenylene ether such as methanol to the solution is known. Further, there is a method of using a mixture of water and alcohols as a non-solvent (Japanese Patent Publication No. 60-23696). Precipitation / precipitation of polyphenylene ether from the polyphenylene ether polymerization reaction liquid in the present invention is a method in which polyphenylene ether reaction liquid is continuously added to alcohols that are non-solvents for polyphenylene ether, or non-solvent. Either a method of adding a polyphenylene ether reaction solution to a mixture of water and water may be used. At that time, the non-solvent weight / good solvent weight ratio is preferably 0.5 to 2.0. Further, when supplying the polymerization reaction liquid, it is preferable that polyphenylene ether is continuously deposited in one or two or more stirred tanks equipped with a reciprocating stirrer.
[0016]
In the present invention, when the precipitated and precipitated polyphenylene ether particles are subjected to solid-liquid separation, any method may be used which is not limited to a method using a normal centrifugal force, a vacuum filtration method using reduced pressure, and the like. Preferably, a vacuum filtration method in which a hard lump of polyphenylene wet solid is difficult to form when separated is preferable.
[0017]
In the present invention, the polyphenylene ether wet solid is supplied continuously or batchwise to one or more stirring tanks and mixed with water to form an aqueous dispersion. The stirrer at this time may be in the same direction or reciprocating. This aqueous dispersion is mixed with water continuously or in batches in one or two or more heating tanks equipped with a stirrer and a circulation path passing through a wet pulverizer.
[0018]
Moreover, a part of water and the polyphenylene ether aqueous dispersion circulate in the tank via a wet pulverizer. The wet crusher should have a structure that can crush solid components in the solution. For example, Gorator (trade name) manufactured by Aikawa Tekko Co., Ltd. and Disintegrator (trade name) manufactured by Komatsu Zenoa Co., Ltd. What it has is preferable.
[0019]
The water / polyphenylene ether wet solids ratio is in the range of 1-100, but is preferably in the range of 2-10. The temperature is 40 to 100 ° C., and the water and the organic solvent carried out of the system by the heat treatment are circulated in the system and recovered outside the system by the coagulation operation. The inside of the system is preferably carried out in an inert gas atmosphere, but the treatment can also be performed in the presence of oxygen. In general, nitrogen, argon, helium or the like is used as the inert gas. The residence time in the tank is 1 to 120 minutes, and the granulated polyphenylene ether is solid-liquid separated continuously or batchwise.
[0020]
According to the method of the present invention, the solidified polyphenylene ether resin after drying has an average particle diameter of 0.2 to 2 mm and a bulk specific gravity of 0.3 to 0.6 g / cc. Thus, when pelletized, it can be suitably used as a molding material without trouble such as poor biting or unmelted portions remaining.
[0021]
【Example】
Hereinafter, the present invention will be described by way of specific examples, but the present invention is not limited thereto, and these can be appropriately modified within the scope of the present invention.
[0022]
The polyphenylene ether particles obtained by the following operation were dried at 135 to 140 ° C. for 6 hours or more while flowing nitrogen at 5 Nm ³ / h to obtain dry powder of polyphenylene ether, and the particle size distribution of the dry powder particles, the average particle size and The proportion of particles of 100 μm or less was measured. The particle size distribution and the ratio of particles of 106 μm or less in the 140 mesh pass were performed according to JIS standard (JIS Z8801). The measurement was carried out using a sieve of 10, 18.5, 60, 120, 140, 280 mesh and vibrating for 10 minutes using a TNK sieve vibrator (manufactured by Tanaka Chemical Equipment Co., Ltd.). Moreover, the average particle diameter was calculated | required by 50% weight average diameter.
[0023]
The extrusion test using an extruder was performed by using a twin screw extruder (PCM-30) manufactured by Ikekai Tekko Co., Ltd., 40 parts by weight of polyphenylene ether powder after drying and a styrene resin (manufactured by Electrochemical Industry Co., Ltd., trade name) HI-UM-301) 60 parts by weight were thoroughly mixed with a mixer, and then melt-kneaded and the strand was cut to obtain pellets of a resin composition in the form of pellets. The incompletely melted polyphenylene ether resin generated in the strand of the extruder was visually observed to determine kneading failure.
[0024]
Reference example 1
2 kg of cupric bromide was dissolved in 35 kg of dibutylamine and 800 kg of toluene. A solution prepared by dissolving 200 kg of 2,6-dimethylphenol in 500 kg of toluene was added to the catalyst solution. These mixed liquids were polymerized in a reactor at 40 ° C. for 3 hours while supplying oxygen. After stopping the reaction, the catalyst was removed from the reaction solution by contacting with water to obtain a polyphenylene ether polymerization reaction solution. The polyphenylene ether reaction solution was added to methanol and precipitated and precipitated while stirring. Thereafter, the liquid was separated with a solid-liquid separator to obtain a wet solid. The liquid content in the wet solid was 60 wt%. The wet solid contained 77 wt% of particles of 106 μm or less.
[0025]
Example 1
Water was added to 100 kg of wet solid obtained by the method described in Reference Example 1 to obtain an aqueous dispersion. The aqueous dispersion was added to warm water at 80 ° C. with stirring. At this time, the weight ratio of polyphenylene ether wet solid / water was 0.01. While this aqueous dispersion is heated, toluene and methanol as solvents are distilled off, and this liquid is circulated through a wet pulverizer (trade name: Golator) at a rate 20 times the total aqueous dispersion and wet. After pulverizing and distilling off the solvent for 1 hour, the aqueous dispersion was extracted. This liquid was subjected to solid-liquid separation to obtain a polyphenylene ether wet solid. The wet solid was dried at 140 ° C. under a nitrogen stream for 6 hours. The particle size of the powder thus obtained was measured using a vibrating sieve. The average particle size was 0.21 mm, and the bulk specific gravity was 0.34 g / cc. When an extruder test was conducted, no kneading failure was observed.
[0026]
Example 2
The polyphenylene ether powder was prepared in the same manner as in Example 1 except that the weight ratio of the polyphenylene ether wet solid / water was 0.5 and the wet pulverizer was circulated at a rate of 0.1 times / hour of the total water dispersion. Obtained. When the particle size of the obtained powder was measured, the average particle size was 0.41 mm, and the bulk specific gravity was 0.33 g / cc. When an extruder test was conducted, no kneading failure was observed.
[0027]
Example 3
A polyphenylene ether powder was obtained in the same manner as in Example 1, except that the weight ratio of polyphenylene ether wet solid / water was 0.5 and the mixture was circulated in a wet pulverizer at a rate 40 times the total water dispersion. . When the particle size of the obtained powder was measured, the average particle size was 0.24 mm, and the bulk specific gravity was 0.37 g / cc. When an extruder test was conducted, no kneading failure was observed.
[0028]
Example 4
A polyphenylene ether powder was obtained in the same manner as in Example 1 except that the polyphenylene ether wet solid / water weight ratio was 0.5, and the mixture was circulated in a wet pulverizer at a rate 20 times the total water dispersion. . When the particle size of the obtained powder was measured, the average particle size was 0.66 mm, and the bulk specific gravity was 0.39 g / cc. When an extruder test was conducted, no abnormality in extrusion was observed.
[0029]
Comparative Example 1
A polyphenylene ether powder was obtained in the same manner as in Example 1 except that the polyphenylene ether wet solid / water weight ratio was 0.5 and the aqueous dispersion was not circulated to the wet pulverizer. When the particle size of the obtained powder was measured, 90% by weight or more of the particle size of the polyphenylene ether powder was 10 mesh or more, and the bulk specific gravity was 0.28 g / cc. When an extruder test was conducted, kneading defects were found.
[0030]
Comparative Example 2
The same procedure as in Example 1 was conducted except that the weight ratio of polyphenylene ether wet solid / water was 7.0 and the wet pulverizer was circulated in the wet pulverizer at a rate of 0.1 times the total water dispersion. In this case, an aqueous dispersion capable of being circulated could not be obtained, and no polyphenylene ether powder was obtained.
[0031]
Comparative Example 3
The same procedure as in Example 1 was performed except that the weight ratio of polyphenylene ether wet solid / water was 0.01 and the mixture was circulated in a wet pulverizer at a rate of 0.1 times the total water dispersion / hour. When the particle size of the obtained powder was measured, 90% by weight or more of the particle size of the polyphenylene ether powder was 10 mesh or more, and the bulk specific gravity was 0.29 g / cc. When an extruder test was conducted, kneading defects were found.
[0032]
【The invention's effect】
According to the present invention, a polyphenylene ether polymerization reaction solution is added with a non-solvent or an aqueous solution thereof to polyphenylene ether as necessary to form a precipitate, followed by solid-liquid separation and separated wet solids. In the process of adding water to water to form an aqueous dispersion and heating to remove the solvent and granulate, at least a part of the aqueous dispersion is circulated to the wet pulverizer, resulting in coarse particles that are larger than necessary. Can be granulated to obtain polyphenylene ether particles having a uniform average particle diameter.

Claims (3)

(A) In the presence of a complex catalyst comprising a metal salt and an amine, a polymerization reaction is carried out by oxidatively polymerizing one or more phenolic compounds using a good solvent of polyphenylene ether or a mixed solvent of a good solvent and a non-solvent. (B) a polymerization terminator or a polymerization terminator and a reducing agent in contact with the obtained polymerization reaction solution to remove the catalyst, and (C) a non-solvent, if necessary. Alternatively, an aqueous solution thereof is added to form a precipitate to produce a slurry solution. (D) The slurry solution containing the precipitate is subjected to solid-liquid separation, and water is added to the separated wet solid to obtain an aqueous dispersion. E) When granulating by removing the solvent by stirring or heating the aqueous dispersion while circulating the aqueous dispersion, (F) at least a part of the aqueous dispersion is circulated to a wet pulverizer and pulverized. and, 循of water dispersion of the wet grinding machine Method for producing a polyphenylene ether resin, wherein the amount is 1 to 30 times / hour of total aqueous dispersion.  The method for producing a polyphenylene ether resin according to claim 1, wherein the weight ratio of the wet solid / water of the polyphenylene ether is in the range of 0.1 to 1.0.  2. The method for producing a polyphenylene ether resin according to claim 1, wherein the solidified polyphenylene ether resin after drying has an average particle diameter of 0.2 to 2 mm and a bulk specific gravity of 0.3 to 0.6 g / cc.