JP2000072420A - Recovering method of phosphoric acid and production of polybenzazole using that phosphoric acid - Google Patents
Recovering method of phosphoric acid and production of polybenzazole using that phosphoric acidInfo
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- JP2000072420A JP2000072420A JP10248159A JP24815998A JP2000072420A JP 2000072420 A JP2000072420 A JP 2000072420A JP 10248159 A JP10248159 A JP 10248159A JP 24815998 A JP24815998 A JP 24815998A JP 2000072420 A JP2000072420 A JP 2000072420A
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- Japan
- Prior art keywords
- phosphoric acid
- waste liquid
- ozone
- weight
- polybenzazole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Treatment Of Water By Oxidation Or Reduction (AREA)
- Polymers With Sulfur, Phosphorus Or Metals In The Main Chain (AREA)
- Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ポリベンザゾール
の製造工程より排出されるリン酸廃液の回収方法とその
再利用に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering a phosphoric acid waste liquid discharged from a process for producing polybenzazole and to reuse the same.
【０００２】[0002]
【従来の技術】ポリパラフェニレンベンゾビスオキサゾ
ール、ポリパラフェニレンベンゾビスチアゾールに代表
されるポリベンザゾールは、非常に高い強度と弾性率を
有し、耐熱性も極めて高いため、次世代の高機能材料と
して注目されている。ポリベンザゾールは、一般的には
テレフタル酸やイソフタル酸などの芳香族ジカルボン酸
と、ジアミノレゾルシノールやジアミノベンゼンジチオ
ールなどのアミノフェノールやアミノチオフェノール化
合物との脱水重縮合により合成される。この際、脱水反
応を促進させるためにポリリン酸が重合溶媒として用い
られる。またポリリン酸の脱水能力を高めるために無水
リン酸を添加することも行われる。2. Description of the Related Art Polybenzazole represented by polyparaphenylene benzobisoxazole and polyparaphenylene benzobisthiazole has extremely high strength and elastic modulus and extremely high heat resistance. It is attracting attention as a material. Polybenzazole is generally synthesized by dehydration polycondensation of an aromatic dicarboxylic acid such as terephthalic acid or isophthalic acid with an aminophenol or aminothiophenol compound such as diaminoresorcinol or diaminobenzenedithiol. At this time, polyphosphoric acid is used as a polymerization solvent to accelerate the dehydration reaction. Further, phosphoric anhydride is added to increase the dehydration ability of polyphosphoric acid.
【０００３】ポリベンザゾールは重合反応後、ポリリン
酸に溶解した溶液、いわゆるポリマードープとして得ら
れ、これらをノズル、ダイから押し出すことで、繊維、
フィルム状に成形される。その後、成形体よりポリリン
酸は水などで抽出され、乾燥、熱処理などを行うと、高
強度、高弾性率、高耐熱性を有した製品となる。これら
一連の工程中に、重合溶媒のポリリン酸は、加水分解を
受けるとともに水で希釈され、大量のリン酸水溶液とし
て排出されるため、その処理方法が問題となっていた。[0003] After the polymerization reaction, polybenzazole is obtained as a solution dissolved in polyphosphoric acid, a so-called polymer dope.
It is formed into a film. Thereafter, the polyphosphoric acid is extracted from the molded body with water or the like, and dried, heat-treated, or the like, to obtain a product having high strength, high elastic modulus, and high heat resistance. During these series of steps, the polyphosphoric acid of the polymerization solvent undergoes hydrolysis and is diluted with water, and is discharged as a large amount of phosphoric acid aqueous solution.
【０００４】リン酸廃液の廃棄処理に関する従来の技術
としては、リン酸廃液を水酸化マグネシウム、水酸化カ
ルシウムなどのアルカリ土類金属水酸化物で中和処理し
て、リン酸のアルカリ土類金属塩として回収し、埋没処
理する方法、あるいはリン酸廃液を活性汚泥により生物
処理する方法などが挙げられる。しかしながら、これら
の方法では大量の廃液を処理することは困難であり、ま
たリン酸を使い捨てすることになるため、経済的にまた
環境的にも問題があった。[0004] As a conventional technique relating to the disposal treatment of phosphoric acid waste liquid, a phosphoric acid waste liquid is neutralized with an alkaline earth metal hydroxide such as magnesium hydroxide or calcium hydroxide to form an alkaline earth metal phosphate. A method of recovering as a salt and burying it, or a method of biologically treating a phosphoric acid waste liquid with activated sludge may be used. However, with these methods, it is difficult to treat a large amount of waste liquid, and since phosphoric acid is disposable, there are economic and environmental problems.
【０００５】ポリベンザゾール製造工程で発生する大量
のリン酸廃液を処理する手段として、リン酸廃液から水
を留去し濃縮する、特に、ポリベンザゾールの重合溶媒
として用いる場合にはポリリン酸となるまで（リン酸換
算濃度で１００重量％以上）濃縮する方法が考えられ
る。しかし、リン酸廃液は、モノマー分解物由来と考え
られる不純物を含有しているために着色しており、その
ままポリベンザゾールの重合溶媒として用いた場合、重
合反応が阻害され、所望の重合度のポリマーを得ること
ができないという問題があった。[0005] As a means for treating a large amount of phosphoric acid waste liquid generated in the polybenzazole production process, water is distilled off from the phosphoric acid waste liquid and concentrated. In particular, when used as a polymerization solvent for polybenzazole, polyphosphoric acid is used. A method of concentrating until the concentration is reached (100% by weight or more in terms of phosphoric acid concentration) is considered. However, the phosphoric acid waste liquid is colored because it contains impurities considered to be derived from monomer decomposition products, and when used directly as a polymerization solvent for polybenzazole, the polymerization reaction is inhibited, and the desired degree of polymerization is not achieved. There was a problem that a polymer could not be obtained.
【０００６】不純物を含有するリン酸を精製する方法と
しては、湿式リン酸製造における精製方法が提案されて
いる。これはおもに溶媒抽出、分解、沈殿工程を組み合
わせて精製する方法である。具体的には、ブタノール、
アミルアルコールなどの有機溶媒で抽出する方法（特公
昭５５−１６０９３号公報）、塩素酸塩と塩化水素と接
触させ不純物を分解する方法（特開昭５９−２４７２３
号公報）、硫化剤などを添加し不純物と沈殿を形成させ
除去する方法（特公昭５５−１１０９９７号公報）など
が挙げられる。[0006] As a method for purifying phosphoric acid containing impurities, a purification method in wet phosphoric acid production has been proposed. This is a method of purifying by mainly combining solvent extraction, decomposition, and precipitation steps. Specifically, butanol,
A method of extracting with an organic solvent such as amyl alcohol (Japanese Patent Publication No. 55-16093), a method of contacting chlorate with hydrogen chloride to decompose impurities (JP-A-59-24723)
And a method of adding a sulfide agent and the like to form and remove impurities and precipitates (Japanese Patent Publication No. 55-110997).
【０００７】しかしながら、これらの処理方法では、工
業用途のリン酸あるいはポリリン酸として再利用でき
ず、特にポリベンザゾールの重合溶媒としてポリリン酸
は再利用できないことが判明した。例えば、有機溶媒で
抽出する方法では不純物の除去が不十分であり、ポリベ
ンザゾールの重合溶媒として再利用した場合、所望の重
合度のポリマーを得ることはできなかった。また塩素酸
塩と塩酸を併用する方法では有機物の分解は可能である
が、一般的な反応装置では塩酸による腐食が問題とな
り、また処理後に残存する塩素酸塩によってモノマーの
分解劣化が起こるため、還元剤処理工程が必要となり、
処理コストの面で問題があった。またポリベンザゾール
製造工程より排出されるリン酸廃液中の含有不純物に対
しては、適当な沈殿形成剤を見出すことはできなかっ
た。However, it has been found that these treatment methods cannot be reused as phosphoric acid or polyphosphoric acid for industrial use, and in particular, polyphosphoric acid cannot be reused as a polymerization solvent for polybenzazole. For example, the method of extracting with an organic solvent does not sufficiently remove impurities, and when reused as a polymerization solvent for polybenzazole, a polymer having a desired polymerization degree could not be obtained. Organic substances can be decomposed by a method using chlorate and hydrochloric acid in combination.However, in a general reaction apparatus, corrosion by hydrochloric acid becomes a problem. A reducing agent treatment step is required,
There was a problem in terms of processing costs. Further, for the impurities contained in the phosphoric acid waste liquid discharged from the polybenzazole production step, no suitable precipitate forming agent could be found.
【０００８】[0008]
【発明が解決しようとする課題】本発明は、上記の問題
点を解決しようとするものであり、その目的は、重合溶
媒としてポリリン酸を用いるポリベンザゾールの製造工
程で排出されるリン酸廃液を低コストで回収し、工業用
途のリン酸あるいはポリリン酸に再生すること、特にポ
リベンザゾールの製造における重合溶媒に再利用可能な
ポリリン酸に再生することにある。SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a phosphoric acid waste liquid discharged in a process of producing polybenzazole using polyphosphoric acid as a polymerization solvent. Is to recover at low cost and regenerate it into phosphoric acid or polyphosphoric acid for industrial use, in particular, to regenerate polyphosphoric acid that can be reused as a polymerization solvent in the production of polybenzazole.
【０００９】[0009]
【課題を解決するための手段】上記問題を解決すべく、
鋭意検討を重ねた結果、本発明を完成するに至った。即
ち、本発明は、以下の通りである。 (1) ポリリン酸を重合溶媒とするポリベンザゾール製造
工程から排出されるリン酸廃液をオゾンと接触させる工
程、およびリン酸廃液をリン酸濃度が７０重量％以上と
なるまで濃縮する工程を含むリン酸の回収方法。 (2) ポリベンザゾール製造工程から排出されるリン酸廃
液をオゾンと接触させた後、リン酸濃度が７０重量％以
上となるまで濃縮することを含む上記(1) に記載のリン
酸の回収方法。 (3) 濃縮が、リン酸換算濃度で１０５重量％以上のポリ
リン酸となるまで行われる上記(1) または(2) に記載の
リン酸の回収方法。 (4) 上記(3) に記載の方法により回収されたポリリン酸
を重合溶媒として用いるポリベンザゾールの製造方法。In order to solve the above problems,
As a result of intensive studies, the present invention has been completed. That is, the present invention is as follows. (1) a step of contacting ozone with a phosphoric acid waste liquid discharged from a polybenzazole production step using polyphosphoric acid as a polymerization solvent, and a step of concentrating the phosphoric acid waste liquid until the phosphoric acid concentration becomes 70% by weight or more. Method for recovering phosphoric acid. (2) The recovery of phosphoric acid according to the above (1), which comprises contacting ozone with a phosphoric acid waste liquid discharged from the polybenzazole production process and concentrating the phosphoric acid until the phosphoric acid concentration becomes 70% by weight or more. Method. (3) The method for recovering phosphoric acid according to the above (1) or (2), wherein the concentration is performed until the concentration of polyphosphoric acid in terms of phosphoric acid is 105% by weight or more. (4) A method for producing polybenzazole using the polyphosphoric acid recovered by the method described in (3) above as a polymerization solvent.
【００１０】[0010]
【作用】本発明のリン酸回収方法は、ポリベンザゾール
の製造工程で排出される、モノマー分解物由来の不純物
を含有する着色リン酸廃液を、オゾンと接触させる工
程、およびリン酸廃液をリン酸濃度が７０重量％以上と
なるまで濃縮する工程を含む方法で処理することによ
り、当該不純物を酸化分解し、無色透明の回収リン酸が
得られる。従って、工業用途のリン酸として、あるいは
リン酸換算濃度で１００重量％以上まで濃縮することに
よりポリリン酸として再利用可能となり、特に、ポリリ
ン酸はポリベンザゾールの製造における重合溶媒として
好適に再利用できる。また本発明のリン酸回収方法にお
いては、処理剤として用いるオゾンが空気や水を原料と
するため、また触媒や紫外線照射などにより容易に酸素
に分解されるため、リン酸回収にかかる処理コストを大
幅に低減する効果を有する。According to the method for recovering phosphoric acid of the present invention, the colored phosphoric acid waste liquid containing impurities derived from monomer decomposition products discharged in the polybenzazole production step is brought into contact with ozone, and the phosphoric acid waste liquid is treated with phosphorus. By treating with a method including a step of concentrating until the acid concentration becomes 70% by weight or more, the impurities are oxidatively decomposed, and colorless and transparent recovered phosphoric acid is obtained. Therefore, it can be reused as phosphoric acid for industrial use or as polyphosphoric acid by concentrating it to 100% by weight or more in terms of phosphoric acid concentration. In particular, polyphosphoric acid is suitably reused as a polymerization solvent in the production of polybenzazole. it can. In addition, in the method for recovering phosphoric acid of the present invention, ozone used as a treating agent is made of air or water as a raw material, and is easily decomposed into oxygen by a catalyst or irradiation with ultraviolet rays. It has the effect of greatly reducing.
【００１１】[0011]
【発明の実施の形態】本発明において、オゾンとリン酸
廃液を接触させる方法としては、特に限定されないが、
リン酸廃液にオゾンガスをバブリングする方法、エゼク
ターを用いる方法、ポンプの吸引側からオゾンガスを導
入してポンプ内で接触させる気液混合ポンプを用いる方
法などが挙げられる。この中でも特に気液混合の効率が
高く、連続的に処理できる点からエゼクターや気液混合
ポンプを用いる方法が望ましい。DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the method of bringing ozone into contact with a phosphoric acid waste liquid is not particularly limited.
Examples include a method of bubbling ozone gas to the phosphoric acid waste liquid, a method of using an ejector, and a method of using a gas-liquid mixing pump in which ozone gas is introduced from the suction side of the pump and brought into contact in the pump. Among them, a method using an ejector or a gas-liquid mixing pump is preferable because the gas-liquid mixing efficiency is particularly high and continuous processing can be performed.
【００１２】オゾンは、一般的には、空気あるいは酸素
を原料とする放電式のオゾン発生器、または水を電気分
解する水電解方式のオゾン発生器により得ることができ
る。空気をオゾン原料とする場合は、オゾン／空気の混
合気体として、水あるいは酸素をオゾン原料とする場合
は、オゾン／酸素の混合気体としてオゾンが得られる。
本発明で用いるオゾンは、いずれの方式で発生させたも
のでも構わないが、水分解方式で発生させたオゾンは、
水分を含むためリン酸廃液中への溶解度が高いという点
で好ましい。Ozone can be generally obtained by a discharge type ozone generator using air or oxygen as a raw material, or a water electrolysis type ozone generator for electrolyzing water. When air is used as the ozone raw material, ozone is obtained as a mixed gas of ozone / air, and when water or oxygen is used as the ozone raw material, ozone is obtained as a mixed gas of ozone / oxygen.
Ozone used in the present invention may be generated by any method, but ozone generated by a water splitting method is
It is preferable in that it contains water and has high solubility in phosphoric acid waste liquid.
【００１３】本発明で用いるオゾンガス中のオゾン濃度
は、１重量％以上が好ましく、１０重量％以上がより好
ましい。１重量％未満のオゾンガスの使用は、リン酸廃
液中へのオゾン溶解度が低くなってオゾンが素抜けし、
リン酸廃液中の不純物に作用する実質的なオゾン量が減
少するため、処理時間が極めて長くかかり、経済的な方
法とは言えない。The ozone concentration in the ozone gas used in the present invention is preferably 1% by weight or more, more preferably 10% by weight or more. The use of less than 1% by weight of ozone gas reduces the solubility of ozone in the phosphoric acid waste liquid and causes ozone to escape.
Since the substantial amount of ozone acting on impurities in the phosphoric acid waste liquid is reduced, the treatment time is extremely long, and it cannot be said to be an economical method.
【００１４】オゾンと接触させる際のリン酸廃液のリン
酸濃度は、リン酸濃度が高くなるに伴い、処理時間が増
大するため、連続的に処理する場合には、リン酸濃度は
好ましくは５０重量％以下、より好ましくは４０重量％
以下、特に好ましくは３０重量％以下である。しかし、
リン酸濃度が５０重量％より高い場合には、バッチ処理
を行いオゾンとの接触時間を長くする方法、あるいはオ
ゾンとの接触処理回数を増やす方法も選択できる。The phosphoric acid concentration of the phosphoric acid waste liquid when it is brought into contact with ozone increases the treatment time as the phosphoric acid concentration increases. % By weight or less, more preferably 40% by weight
Or less, particularly preferably 30% by weight or less. But,
When the phosphoric acid concentration is higher than 50% by weight, a method of performing a batch treatment to increase the contact time with ozone or a method of increasing the number of times of the contact treatment with ozone can be selected.
【００１５】リン酸廃液とオゾンガスとを接触させる際
の混合割合は、リン酸廃液重量に対するオゾン添加量が
好ましくは５ｐｐｍ以上、より好ましくは１０ｐｐｍ以
上、最も好ましくは１５ｐｐｍ以上となるように設定す
る。ガス流量が多過ぎる場合には、エゼクターや気液混
合ポンプがキャビテーションを引き起こして混合不良に
陥り、不純物の分解効果が低下する恐れがあるため、使
用する気液混合装置の能力範囲内とする。また、リン酸
廃液重量に対するオゾン添加量が５ｐｐｍ未満の場合は
オゾンによるモノマー分解物由来の不純物への分解作用
が不十分であり、無色透明のリン酸を得ることが困難で
ある。The mixing ratio when the phosphoric acid waste liquid and the ozone gas are brought into contact is set so that the amount of ozone added to the weight of the phosphoric acid waste liquid is preferably 5 ppm or more, more preferably 10 ppm or more, and most preferably 15 ppm or more. If the gas flow rate is too large, the ejector or the gas-liquid mixing pump may cause cavitation, resulting in poor mixing, and the effect of decomposing impurities may be reduced. On the other hand, when the amount of ozone added is less than 5 ppm based on the weight of the phosphoric acid waste liquid, the action of ozone to decompose impurities derived from monomer decomposition products is insufficient, and it is difficult to obtain colorless and transparent phosphoric acid.
【００１６】リン酸廃液の濃縮工程では、濃縮は、減圧
下、加熱し、水を留去することで達成できる。但し、リ
ン酸は腐食性が高いため、濃縮装置の接液部には、パイ
レックスガラス、ハステロイＢ、ハステロイＣなどの耐
腐食性材料を用いることが望ましい。濃縮工程は、一段
濃縮、多段濃縮のいずれでも良いが、ポリリン酸まで濃
縮する（リン酸換算濃度で１００重量％以上）場合は、
まず７０重量％以上まで濃縮し、ついで１００重量％以
上のリン酸すなわちポリリン酸まで濃縮する二段階以上
の濃縮が好ましい。また、特にポリベンザゾールの重合
溶媒として用いる場合には、ポリマー製造工程で十分な
重合速度を得るために、ポリリン酸の濃度がリン酸換算
濃度で１０５重量％以上となるまで濃縮することが好ま
しい。In the step of concentrating the phosphoric acid waste liquid, the concentration can be achieved by heating under reduced pressure to distill off water. However, since phosphoric acid is highly corrosive, it is desirable to use a corrosion-resistant material such as Pyrex glass, Hastelloy B, or Hastelloy C for the liquid contact part of the concentrator. The concentration step may be either one-stage concentration or multi-stage concentration, but when concentrating up to polyphosphoric acid (100% by weight or more in terms of phosphoric acid concentration),
It is preferable to first concentrate to 70% by weight or more, and then to concentrate to 100% by weight or more of phosphoric acid, that is, polyphosphoric acid. In particular, when used as a polymerization solvent for polybenzazole, it is preferable to concentrate the polyphosphoric acid until the concentration of polyphosphoric acid becomes 105% by weight or more in terms of phosphoric acid in order to obtain a sufficient polymerization rate in the polymer production process. .
【００１７】オゾン処理工程と濃縮工程の順序は特に限
定されず、オゾン処理工程はリン酸濃縮前、中間濃縮段
階、濃縮後のいずれでも実施することができるが、上述
のようにリン酸廃液中のリン酸濃度が高いほど不純物の
分解処理に時間がかかるため、オゾン処理工程を行った
後、濃縮工程を行うことが望ましい。またオゾン処理工
程と濃縮工程は、他の処理工程と組み合わせて実施する
こともできる。例えば、ポリマーくずや不溶性不純物な
どの浮遊成分による、濃縮装置内のスケール形成抑制、
あるいは混合装置破損回避のために、ろ過工程を設ける
ことができる。また、特にオゾン処理工程の後には、紫
外線照射などの廃オゾンを処理する工程を設けることも
できる。The order of the ozone treatment step and the concentration step is not particularly limited, and the ozone treatment step can be performed before, during, or after the concentration of phosphoric acid. Since the higher the phosphoric acid concentration, the longer it takes to decompose impurities, it is desirable to perform the concentration step after the ozone treatment step. Also, the ozone treatment step and the concentration step can be performed in combination with other treatment steps. For example, suppression of scale formation in the concentrator due to suspended components such as polymer waste and insoluble impurities,
Alternatively, a filtration step can be provided to avoid breakage of the mixing device. Further, after the ozone treatment step, a step of treating waste ozone such as ultraviolet irradiation may be provided.
【００１８】オゾン処理工程と濃縮工程後に得られるポ
リリン酸を、ポリベンザゾールの重合溶媒として再利用
する場合、その重合条件は、市販の新しいポリリン酸を
用いた場合と同様である。すなわち、ポリリン酸に無水
リン酸とモノマーとを添加後、混合加熱し、脱水重縮合
させる。脱水重縮合時の反応温度は５０〜２３０℃の間
で設定される、より具体的には、５０〜１７０℃で攪拌
混合とオリゴマー化を、次いで１６０〜２３０℃でポリ
マー化を行う段階的な反応がより好ましい。When the polyphosphoric acid obtained after the ozone treatment step and the concentration step is reused as a polymerization solvent for polybenzazole, the polymerization conditions are the same as those when a commercially available new polyphosphoric acid is used. That is, after phosphoric anhydride and a monomer are added to polyphosphoric acid, they are mixed and heated to cause dehydration polycondensation. The reaction temperature at the time of dehydration polycondensation is set between 50 and 230 ° C., more specifically, stepwise mixing and oligomerization at 50 to 170 ° C. followed by polymerization at 160 to 230 ° C. Reactions are more preferred.
【００１９】このようなリン酸回収方法により得られた
ポリリン酸を重合溶媒として製造したポリベンザゾール
は、新しいポリリン酸（再生したポリリン酸ではない）
を重合溶媒として製造したポリベンザゾールと比較して
も、色調は同等であり、重合度も充分に高く、同水準の
品質を有するものである。Polybenzazole produced using polyphosphoric acid obtained by such a phosphoric acid recovery method as a polymerization solvent is a new polyphosphoric acid (not a regenerated polyphosphoric acid).
The color tone is the same, the degree of polymerization is sufficiently high, and the same level of quality is obtained even when compared with polybenzazole produced by using as a polymerization solvent.
【００２０】回収されたリン酸のポリベンザゾールの重
合溶媒以外の用途としては、例えば、肥料、金属表面処
理剤などが挙げられる。Examples of uses other than the polymerization solvent for the recovered polybenzazole of phosphoric acid include fertilizers and metal surface treatment agents.
【００２１】以下に本発明の一実施形態を、シス−ポリ
パラフェニレンベンゾビスオキサゾールを例に挙げ説明
する。シス−ポリパラフェニレンベンゾビスオキサゾー
ル製造工程より排出されたリン酸廃液（リン酸濃度１５
〜２５重量％）をろ過し、ポリマーくずなどの浮遊物を
除去する。ついで、ろ過したリン酸廃液を気液混合装置
中に流通し、オゾンガス（オゾン濃度１３〜１９重量
％）と接触させる。この際、リン酸廃液重量に対するオ
ゾン添加量が５ｐｐｍ以上になるように、オゾンガスと
リン酸廃液流量を調整する。Hereinafter, an embodiment of the present invention will be described with reference to cis-polyparaphenylenebenzobisoxazole. Phosphoric acid waste liquid (phosphoric acid concentration 15) discharged from the cis-polyparaphenylenebenzobisoxazole manufacturing process
２５25% by weight) to remove suspended matter such as polymer debris. Next, the filtered phosphoric acid waste liquid is passed through a gas-liquid mixing device, and is brought into contact with ozone gas (ozone concentration of 13 to 19% by weight). At this time, the flow rates of the ozone gas and the phosphoric acid waste liquid are adjusted so that the amount of ozone added to the weight of the phosphoric acid waste liquid is 5 ppm or more.
【００２２】オゾン処理後のリン酸廃液を、５０〜１５
０℃／５〜２００ｍｍＨｇの条件で５０〜９０重量％ま
で濃縮すると無色透明のリン酸が得られる。シス−ポリ
パラフェニレンベンゾビスオキサゾールの重合溶媒とし
て用いる場合は、５０〜９０重量％のリン酸を、さらに
１５０〜２５０℃／０．０１〜１０ｍｍＨｇの条件で濃
縮し、リン酸換算濃度１１０重量％以上の無色透明のポ
リリン酸を得る。After the ozone treatment, the phosphoric acid waste liquid is treated with 50 to 15
When it is concentrated to 50 to 90% by weight under the condition of 0 ° C./5 to 200 mmHg, colorless and transparent phosphoric acid is obtained. When used as a polymerization solvent for cis-polyparaphenylenebenzobisoxazole, 50 to 90% by weight of phosphoric acid is further concentrated under the conditions of 150 to 250 ° C./0.01 to 10 mmHg, and the concentration in terms of phosphoric acid is 110% by weight. The above colorless and transparent polyphosphoric acid is obtained.
【００２３】以上のようにして得られるポリリン酸に、
窒素などの不活性ガス雰囲気中で、無水リン酸を加えた
後、モノマーの４，６−ジアミノレゾルシノール二塩酸
塩とテレフタル酸を添加し、５０〜１００℃で攪拌混合
後、１００〜１８０℃で０．５〜２４時間、さらに１８
０〜２３０℃で０．１〜３時間加熱重合することでシス
−ポリパラフェニレンベンゾビスオキサゾールを得るこ
とができる。In the polyphosphoric acid obtained as described above,
In an atmosphere of an inert gas such as nitrogen, phosphoric anhydride is added, then the monomers 4,6-diaminoresorcinol dihydrochloride and terephthalic acid are added, and the mixture is stirred and mixed at 50 to 100 ° C. 0.5 to 24 hours, 18 more
By heating and polymerizing at 0 to 230 ° C for 0.1 to 3 hours, cis-polyparaphenylenebenzobisoxazole can be obtained.
【００２４】[0024]
【実施例】本発明をさらに詳細に説明するために以下に
実施例を示す。なお、実施例中のポリマーの固有粘度
は、０．１Ｍメタンスルホン酸ナトリウム／蒸留メタン
スルホン酸中、２５℃で測定した。The following examples are provided to explain the present invention in more detail. The intrinsic viscosities of the polymers in the examples were measured at 25 ° C. in 0.1 M sodium methanesulfonate / distilled methanesulfonic acid.
【００２５】実施例１ シス−ポリパラフェニレンベンゾビスオキサゾールの製
造工程より排出されたリン酸廃液（リン酸濃度２０重量
％）を、孔径１０μｍのテフロンフィルターでろ過し、
ポリマーくずや不溶性不純物などの浮遊物を除去した。
ろ過したリン酸廃液を、気液混合ポンプを用い送液しな
がら、水電解式オゾン発生装置から得られたオゾン濃度
１７重量％のオゾンガスと接触混合させた。この際、リ
ン酸廃液重量に対するオゾン添加量が１５ｐｐｍとなる
ようにオゾンガスとリン酸廃液の流速を調整した。オゾ
ン処理後のリン酸廃液を７０〜８０℃／３０ｍｍＨｇの
条件でロータリーエバポレータを用いて７５重量％まで
濃縮した。次いで７５重量％リン酸を薄膜蒸留装置を用
いて２００〜２２０℃／０．０１〜１０ｍｍＨｇの条件
で２回濃縮し、リン酸換算濃度１１０重量％の無色透明
のポリリン酸を得た。Example 1 Phosphoric acid waste liquid (phosphoric acid concentration: 20% by weight) discharged from the process of producing cis-polyparaphenylenebenzobisoxazole was filtered through a Teflon filter having a pore size of 10 μm.
Suspended matters such as polymer debris and insoluble impurities were removed.
The filtered phosphoric acid waste liquid was contacted and mixed with an ozone gas having an ozone concentration of 17% by weight obtained from a water electrolysis type ozone generator while sending the liquid using a gas-liquid mixing pump. At this time, the flow rates of the ozone gas and the phosphoric acid waste liquid were adjusted so that the ozone addition amount relative to the weight of the phosphoric acid waste liquid was 15 ppm. The phosphoric acid waste liquid after the ozone treatment was concentrated to 75% by weight using a rotary evaporator under the conditions of 70 to 80 ° C./30 mmHg. Then, 75% by weight of phosphoric acid was concentrated twice using a thin-film distillation apparatus under the conditions of 200 to 220 ° C./0.01 to 10 mmHg to obtain a colorless and transparent polyphosphoric acid having a concentration of 110% by weight in terms of phosphoric acid.
【００２６】以上のようにして得られた１１０重量％の
ポリリン酸３５．４ｇに、無水リン酸２３．０ｇと４，
６−ジアミノレゾルシノール二塩酸塩９．１０ｇとテレ
フタル酸７．１０ｇとを添加し、７０℃で攪拌混合後、
１３０℃で１２時間、２００℃で２時間重合させ、シス
−ポリパラフェニレンベンゾビスオキサゾールを得た。
得られたポリマーの固有粘度は４３ｄｌ／ｇ、ポリマー
ドープの色は黄色であり、新しいポリリン酸から重合し
たポリマーの色調、重合度と同水準の品質であった。To 35.4 g of the 110% by weight polyphosphoric acid obtained as described above, 23.0 g of phosphoric anhydride and 4,4
6.10 g of 6-diaminoresorcinol dihydrochloride and 7.10 g of terephthalic acid were added, and stirred and mixed at 70 ° C.,
Polymerization was performed at 130 ° C. for 12 hours and at 200 ° C. for 2 hours to obtain cis-polyparaphenylenebenzobisoxazole.
The intrinsic viscosity of the obtained polymer was 43 dl / g, the color of the polymer dope was yellow, and the quality was the same level as the color tone and the degree of polymerization of the polymer polymerized from the new polyphosphoric acid.
【００２７】実施例２ シス−ポリパラフェニレンベンゾビスオキサゾールの製
造工程より排出されたリン酸廃液（リン酸濃度２０重量
％）を、孔径１０μｍのテフロンフィルターでろ過し、
ポリマーくずや不溶性不純物などの浮遊物を除去した。
ろ過したリン酸廃液を、送液ポンプを用いエゼクターに
送液しながら、放電式オゾン発生装置から得られたオゾ
ン濃度２重量％のオゾンガスと接触混合させた。この
際、リン酸廃液重量に対するオゾン添加量が４０ｐｐｍ
となるようにオゾンガスとリン酸廃液の流速を調整し
た。オゾン処理後のリン酸廃液を７０〜８０℃／３０ｍ
ｍＨｇの条件でロータリーエバポレータを用いて７５重
量％まで濃縮した。次いで７５重量％リン酸を薄膜蒸留
装置を用いて２００〜２２０℃／０．０１〜１０ｍｍＨ
ｇの条件で２回濃縮し、リン酸換算濃度１１０重量％の
無色透明のポリリン酸を得た。Example 2 Phosphoric acid waste liquid (phosphoric acid concentration: 20% by weight) discharged from the process of producing cis-polyparaphenylene benzobisoxazole was filtered through a Teflon filter having a pore size of 10 μm.
Suspended matters such as polymer debris and insoluble impurities were removed.
The filtered phosphoric acid waste liquid was contact-mixed with an ozone gas having an ozone concentration of 2% by weight obtained from a discharge type ozone generator, while being sent to an ejector using a liquid sending pump. At this time, the amount of ozone added was 40 ppm based on the weight of the phosphoric acid waste liquid.
The flow rates of the ozone gas and the phosphoric acid waste liquid were adjusted so that Phosphoric acid waste liquid after ozone treatment is 70-80 ° C / 30m
It concentrated to 75% by weight using a rotary evaporator under the condition of mHg. Then, 75% by weight of phosphoric acid was added at 200 to 220 ° C / 0.01 to 10 mmH using a thin film distillation apparatus.
The solution was concentrated twice under the condition of g, to obtain a colorless and transparent polyphosphoric acid having a concentration of 110% by weight in terms of phosphoric acid.
【００２８】以上のようにして得られた１１０重量％の
ポリリン酸３５．４ｇに、無水リン酸２３．０ｇと４，
６−ジアミノレゾルシノール二塩酸塩９．１０ｇとテレ
フタル酸７．１０ｇとを添加し、７０℃で攪拌混合後、
１３０℃で１２時間、２００℃で２時間重合させ、シス
−ポリパラフェニレンベンゾビスオキサゾールを得た。
得られたポリマーの固有粘度は４０ｄｌ／ｇ、ポリマー
ドープの色は黄色であり、新しいポリリン酸から重合し
たポリマーの色調、重合度と同水準の品質であった。To 35.4 g of the 110% by weight polyphosphoric acid obtained as described above, 23.0 g of phosphoric anhydride and 4,4
6.10 g of 6-diaminoresorcinol dihydrochloride and 7.10 g of terephthalic acid were added, and stirred and mixed at 70 ° C.,
Polymerization was performed at 130 ° C. for 12 hours and at 200 ° C. for 2 hours to obtain cis-polyparaphenylenebenzobisoxazole.
The intrinsic viscosity of the obtained polymer was 40 dl / g, the color of the polymer dope was yellow, and the quality was the same as the color tone and the degree of polymerization of the polymer polymerized from the new polyphosphoric acid.
【００２９】比較例１ シス−ポリパラフェニレンベンゾビスオキサゾールの製
造工程より排出されたリン酸廃液（リン酸濃度２０重量
％）を、オゾン処理工程を行わずに実施例１と同様の条
件で濃縮し、黒褐色の１１０重量％のポリリン酸を得
た。このポリリン酸を重合溶媒として実施例１と同じ条
件で重合を行ったところ、得られたシス−ポリパラフェ
ニレンベンゾビスオキサゾールは緑色で、ポリマーの固
有粘度は２１ｄｌ／ｇであり、新しいポリリン酸から重
合したポリマーの色調、重合度よりも劣るものであっ
た。Comparative Example 1 The phosphoric acid waste liquid (phosphoric acid concentration: 20% by weight) discharged from the process of producing cis-polyparaphenylenebenzobisoxazole was concentrated under the same conditions as in Example 1 without performing the ozone treatment step. Then, a black-brown 110% by weight of polyphosphoric acid was obtained. When polymerization was carried out under the same conditions as in Example 1 using this polyphosphoric acid as a polymerization solvent, the obtained cis-polyparaphenylenebenzobisoxazole was green, and the intrinsic viscosity of the polymer was 21 dl / g. The color tone and the degree of polymerization of the polymerized polymer were inferior.
【００３０】実施例３ トランス−ポリパラフェニレンベンゾビスチアゾールの
製造工程より排出されたリン酸廃液（リン酸濃度２０重
量％）を、孔径１０μｍのテフロンフィルターでろ過
し、ポリマーくずや不溶性不純物などの浮遊物を除去し
た。ろ過したリン酸廃液を、気液混合ポンプを用い送液
しながら、水電解式オゾン発生装置から得られたオゾン
濃度１７重量％のオゾンガスと接触混合させた。この
際、リン酸廃液重量に対するオゾン添加量が１５ｐｐｍ
となるようにオゾンガスとリン酸廃液の流速を調整し
た。オゾン処理後のリン酸廃液を７０〜８０℃／３０ｍ
ｍＨｇの条件でロータリーエバポレータを用いて７５重
量％まで濃縮した。次いで７５重量％リン酸を薄膜蒸留
装置を用いて２００〜２２０℃／０．０１〜１０ｍｍＨ
ｇの条件で２回濃縮し、リン酸換算濃度１１０重量％の
無色透明のポリリン酸を得た。Example 3 Phosphoric acid waste liquid (phosphoric acid concentration: 20% by weight) discharged from the process for producing trans-polyparaphenylene benzobisthiazole was filtered through a Teflon filter having a pore size of 10 μm to remove polymer waste and insoluble impurities. Floats were removed. The filtered phosphoric acid waste liquid was contacted and mixed with an ozone gas having an ozone concentration of 17% by weight obtained from a water electrolysis type ozone generator while sending the liquid using a gas-liquid mixing pump. At this time, the amount of ozone added was 15 ppm based on the weight of the phosphoric acid waste liquid.
The flow rates of the ozone gas and the phosphoric acid waste liquid were adjusted so that Phosphoric acid waste liquid after ozone treatment is 70-80 ° C / 30m
It concentrated to 75% by weight using a rotary evaporator under the condition of mHg. Then, 75% by weight of phosphoric acid was added at 200 to 220 ° C./0.01 to 10 mmH using a thin film distillation apparatus.
The mixture was concentrated twice under the condition of g, to obtain colorless and transparent polyphosphoric acid having a concentration of 110% by weight in terms of phosphoric acid.
【００３１】以上のようにして得られた１１０重量％の
ポリリン酸３５．４ｇに、無水リン酸２３．０ｇと２，
５−ジアミノ−１，４−べンゼンジチオール二塩酸塩１
０．４８ｇとテレフタル酸７．１０ｇとを添加し、７０
℃で攪拌混合後、１３０℃で１２時間、２００℃で２時
間重合させ、トランス−ポリパラフェニレンベンゾビス
チアゾールを得た。得られたポリマーの固有粘度は４０
ｄｌ／ｇ、ポリマードープの色は濃黄緑色であり、新し
いポリリン酸から重合したポリマーの色調、重合度と同
水準の品質であった。To 35.4 g of the 110% by weight polyphosphoric acid obtained as described above, 23.0 g of phosphoric anhydride and 2,2
5-diamino-1,4-benzenedithiol dihydrochloride 1
0.48 g and 7.10 g of terephthalic acid were added, and 70
After stirring and mixing at a temperature of 130 ° C., polymerization was carried out at 130 ° C. for 12 hours and at 200 ° C. for 2 hours to obtain trans-polyparaphenylenebenzobisthiazole. The intrinsic viscosity of the obtained polymer is 40
dl / g, the color of the polymer dope was dark yellow-green, and the quality was the same level as the color tone and degree of polymerization of the polymer polymerized from the new polyphosphoric acid.
【００３２】実施例４ トランス−ポリパラフェニレンベンゾビスチアゾールの
製造工程より排出されたリン酸廃液（リン酸濃度２０重
量％）を、孔径１０μｍのテフロンフィルターでろ過
し、ポリマーくずや不溶性不純物などの浮遊物を除去し
た。ろ過したリン酸廃液を、送液ポンプを用いエゼクタ
ーに送液しながら、放電式オゾン発生装置から得られた
オゾン濃度２重量％のオゾンガスと接触混合させた。こ
の際、リン酸廃液重量に対するオゾン添加量が４０ｐｐ
ｍとなるようにオゾンガスとリン酸廃液の流速を調整し
た。オゾン処理後のリン酸廃液を７０〜８０℃／３０ｍ
ｍＨｇの条件でロータリーエバポレータを用いて７５重
量％まで濃縮した。次いで７５重量％リン酸を薄膜蒸留
装置を用いて２００〜２２０℃／０．０１〜１０ｍｍＨ
ｇの条件で２回濃縮し、リン酸換算濃度１１０重量％の
無色透明のポリリン酸を得た。Example 4 Phosphoric acid waste liquid (phosphoric acid concentration: 20% by weight) discharged from the process of producing trans-polyparaphenylene benzobisthiazole was filtered through a Teflon filter having a pore size of 10 μm to remove polymer waste and insoluble impurities. Floats were removed. The filtered phosphoric acid waste liquid was contact-mixed with an ozone gas having an ozone concentration of 2% by weight obtained from a discharge type ozone generator while sending the filtered phosphoric acid waste liquid to an ejector using a liquid sending pump. At this time, the amount of ozone added to the phosphoric acid waste liquid weight was 40 pp.
m and the flow rates of the ozone gas and the phosphoric acid waste liquid were adjusted. Phosphoric acid waste liquid after ozone treatment is 70-80 ° C / 30m
It concentrated to 75% by weight using a rotary evaporator under the condition of mHg. Then, 75% by weight of phosphoric acid was added at 200 to 220 ° C./0.01 to 10 mmH using a thin film distillation apparatus.
The mixture was concentrated twice under the condition of g, to obtain colorless and transparent polyphosphoric acid having a concentration of 110% by weight in terms of phosphoric acid.
【００３３】以上のようにして得られた１１０重量％の
ポリリン酸３５．４ｇに、無水リン酸２３．０ｇと２，
５−ジアミノ−１，４−べンゼンジチオール二塩酸塩１
０．４８ｇとテレフタル酸７．１０ｇとを添加し、７０
℃で攪拌混合後、１３０℃で１２時間、２００℃で２時
間重合させ、トランス−ポリパラフェニレンベンゾビス
チアゾールを得た。得られたポリマーの固有粘度は４１
ｄｌ／ｇ、ポリマードープの色は濃黄緑色であり、新し
いポリリン酸から重合したポリマーの色調、重合度と同
水準の品質であった。To 35.4 g of the 110% by weight polyphosphoric acid obtained as described above, 23.0 g of phosphoric anhydride and 2,2
5-diamino-1,4-benzenedithiol dihydrochloride 1
0.48 g and 7.10 g of terephthalic acid were added, and 70
After stirring and mixing at a temperature of 130 ° C., polymerization was carried out at 130 ° C. for 12 hours and at 200 ° C. for 2 hours to obtain trans-polyparaphenylenebenzobisthiazole. The intrinsic viscosity of the obtained polymer is 41.
dl / g, the color of the polymer dope was dark yellow-green, and the quality was the same level as the color tone and degree of polymerization of the polymer polymerized from the new polyphosphoric acid.
【００３４】比較例２ トランス−ポリパラフェニレンベンゾビスチアゾールの
製造工程より排出されたリン酸廃液（リン酸濃度２０重
量％）を、オゾン処理工程を行わずに実施例３と同様の
条件で濃縮し、黒褐色の１１０重量％のポリリン酸を得
た。このポリリン酸を重合溶媒として実施例３と同じ条
件で重合を行ったところ、得られたトランス−ポリパラ
フェニレンベンゾビスチアゾールは緑色で、ポリマーの
固有粘度は２１ｄｌ／ｇであり、新しいポリリン酸から
重合したポリマーの色調、重合度よりも劣るものであっ
た。Comparative Example 2 Phosphoric acid waste liquid (phosphoric acid concentration: 20% by weight) discharged from the process for producing trans-polyparaphenylenebenzobisthiazole was concentrated under the same conditions as in Example 3 without performing the ozone treatment step. Then, a black-brown 110% by weight of polyphosphoric acid was obtained. When the polymerization was carried out under the same conditions as in Example 3 using this polyphosphoric acid as a polymerization solvent, the obtained trans-polyparaphenylenebenzobisthiazole was green, the intrinsic viscosity of the polymer was 21 dl / g, and The color tone and the degree of polymerization of the polymerized polymer were inferior.
【００３５】[0035]
【発明の効果】以上の説明で明らかなように、本発明に
よれば、ポリベンザゾール製造工程から排出される大量
のリン酸廃液を工業用途のリン酸として、特にポリベン
ザゾールの重合溶媒として低コストで再利用することが
可能となり、産業廃棄物の低減、地球資源の節約に寄与
するところ大である。As is clear from the above description, according to the present invention, a large amount of phosphoric acid waste liquid discharged from the polybenzazole production process is used as phosphoric acid for industrial use, particularly as a polymerization solvent for polybenzazole. It can be reused at low cost, greatly reducing industrial waste and conserving global resources.
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 4D050 AA13 AB03 BB02 CA15 4J043 PA02 QB34 QB35 SA06 SA71 SA83 SB01 TA12 TB01 UA122 VA012 XA11 XB13 XB17 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D050 AA13 AB03 BB02 CA15 4J043 PA02 QB34 QB35 SA06 SA71 SA83 SB01 TA12 TB01 UA122 VA012 XA11 XB13 XB17
Claims (4)
ゾール製造工程から排出されるリン酸廃液をオゾンと接
触させる工程、およびリン酸廃液をリン酸濃度が７０重
量％以上となるまで濃縮する工程を含むリン酸の回収方
法。1. A step of contacting ozone with a phosphoric acid waste liquid discharged from a polybenzazole production step using polyphosphoric acid as a polymerization solvent, and a step of concentrating the phosphoric acid waste liquid until the phosphoric acid concentration becomes 70% by weight or more. And a method for recovering phosphoric acid.
るリン酸廃液をオゾンと接触させた後、リン酸濃度が７
０重量％以上となるまで濃縮することを含む請求項１に
記載のリン酸の回収方法。2. After the phosphoric acid waste liquid discharged from the polybenzazole production step is brought into contact with ozone, the phosphoric acid concentration becomes 7
The method for recovering phosphoric acid according to claim 1, comprising concentrating the phosphoric acid to 0% by weight or more.
以上のポリリン酸となるまで行われる請求項１または２
に記載のリン酸の回収方法。3. The concentration is 105% by weight in terms of phosphoric acid concentration.
3. The method according to claim 1, wherein the reaction is carried out until the above polyphosphoric acid is obtained.
3. The method for recovering phosphoric acid according to item 1.
ポリリン酸を重合溶媒として用いるポリベンザゾールの
製造方法。4. A method for producing polybenzazole using the polyphosphoric acid recovered by the method according to claim 3 as a polymerization solvent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24815998A JP4164908B2 (en) | 1998-09-02 | 1998-09-02 | Method for recovering phosphoric acid and method for producing polybenzazole using phosphoric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24815998A JP4164908B2 (en) | 1998-09-02 | 1998-09-02 | Method for recovering phosphoric acid and method for producing polybenzazole using phosphoric acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000072420A true JP2000072420A (en) | 2000-03-07 |
| JP4164908B2 JP4164908B2 (en) | 2008-10-15 |
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ID=17174108
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24815998A Expired - Lifetime JP4164908B2 (en) | 1998-09-02 | 1998-09-02 | Method for recovering phosphoric acid and method for producing polybenzazole using phosphoric acid |
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| Country | Link |
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| JP (1) | JP4164908B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009081986A1 (en) | 2007-12-26 | 2009-07-02 | Nano Carbon Technologies Co., Ltd. | Planar heating element obtained using dispersion of fine carbon fibers in water and process for producing the planar heating element |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11608306B2 (en) * | 2020-05-08 | 2023-03-21 | Hyconix, Inc. | Process for generating acid anhydrides |
-
1998
- 1998-09-02 JP JP24815998A patent/JP4164908B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009081986A1 (en) | 2007-12-26 | 2009-07-02 | Nano Carbon Technologies Co., Ltd. | Planar heating element obtained using dispersion of fine carbon fibers in water and process for producing the planar heating element |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4164908B2 (en) | 2008-10-15 |
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