JP3986713B2 - Method for purifying hydrogen chloride containing organic matter - Google Patents

Description

【００１２】
上記一般式中、Ｒ₁ 〜Ｒ₃ は、水素原子、Ｃｌ、Ｂｒ等のハロゲン原子、ハロゲン置換されていることもある、炭素数１〜３０のアルキル基、アリル基、アルケニル基、アルコキシル基、アルコキシアルキル基等の置換基であり、これら置換基中の炭素原子の一部が他の原子（Ｏ、Ｓ、Ｎ等）で置換されているものもある。そのほか、本発明の精製方法によって除去されるべき不純物として、炭素数１〜６の塩素化炭化水素があり、具体的には、四塩化炭素、クロロホルム、塩化メチレン、ジクロロエタン、トリクロロエタン、ヘキサクロロエタン等が挙げられる。これらは、ホスゲン製造の際の生成し、混入したものと考えられる。
【００１３】
最も一般的に検出される不純物は、アリールアルコールであり、またアリールアルコール誘導体として最も一般的に検出されるものに、オルト位及び／又はパラ位がＢｒ置換されたフェノールがある。具体的には、オルトブロモフェノール、パラブロモフェノール、２，４−ジブロモフェノール等のＢｒ置換体である。これらＢｒ置換体は、ホスゲンとアリールアルコールとの反応に際し、ホスゲン中の不純物であるブロモカルボニルが、アリールアルコールのオルト位及び／又はパラ位の水素をＢｒ置換することによって生成し、塩化水素に混入したものと考えられる。なお、ブロモカルボニルは、電解塩素中に不純物として存在する臭素に起因すると考えられる。
【００１４】
また、アリールアルコール誘導体の内で注目すべき不純物としては、上記Ｂｒ置換体のほかに、多置換体等、分子サイズの大きな置換体がある。これらの置換体としては、Ｃｌ置換体、アルキル置換体、アリル置換体が挙げられる。しかして、Ｃｌ置換体は、ホスゲン中の未反応塩素がアリールアルコールを塩素化した生成物が、また、アルキル置換体及びアリル置換体は、アリールアルコール中に元来不純物として存在していたものが、それぞれ、塩化水素に混入したものと考えられる。
【００１５】
しかして、本発明において精製の対象となる塩化水素の不純物レベルは、広い範囲に及び、３５％塩化水素水溶液中の有機物、特にアリールアルコール及びその誘導体の含有量として、通常、３０〜３０００００ｎｇ／ｍｌ程度であるが、本発明を適用することにより１ｎｇ／ｍｌ程度又はそれ以下のレベルまで精製することができる。
本発明により精製された塩化水素の不純物レベルは、３５％塩化水素水溶液中のアリールアルコール及びその誘導体の含有量として、１０ｎｇ／ｍｌ以下、好ましくは５ｎｇ／ｍｌ以下、更に好ましくは、１ｎｇ／ｍｌ以下である。特に、半導体用等、品質要求の厳しい用途においては、Ｂｒ置換体の含有量として、５ｎｇ／ｍｌ以下、好ましくは１ｎｇ／ｍｌ以下、更に好ましくは、０．１ｎｇ／ｍｌ以下が望ましい。
【００１６】
合成樹脂吸着剤
本発明の精製処理に用いる合成樹脂吸着剤は、吸着能を有する合成樹脂であれば特に制限はない。スチレン−ジビニルベンゼン系、フェノール系、メタクリル系の樹脂等が例示できるが、スチレン−ジビニルベンゼン系が好ましい。この合成樹脂吸着剤として、通常、３０〜１０００Å、特に、３０〜１００Å、更には、３０〜７０Åの細孔直径を有する細孔の容積が０．５ｍｌ／ｇ以上であることが好ましい。この細孔容積が不十分であると、吸着初期に合成樹脂吸着剤に一旦吸着された不純物が後から導入される塩化水素の流れによって脱着され、著量のアリールアルコール誘導体の定常的なリーク現象をひき起こし、精製処理後の塩化水素中のアリールアルコール誘導体のレベルを、このリーク量以下に低減することが不可能となる。すなわち、３５％塩化水素水溶液中のアリールアルコール及びその誘導体の含有量として、１０ｎｇ／ｍｌ以下にすることができず、前記した半導体用には適さない。
【００１７】
本発明においては、合成樹脂吸着剤として、３０〜１００Åの細孔直径を有する細孔の容積が０．５ｍｌ／ｇ以上の合成樹脂吸着剤を使用することが、より有効である。この範囲の細孔直径を有する細孔の容積が小さすぎると、上記アリールアルコール誘導体の内、Ｂｒ置換体や多置換体等の分子サイズの大きな化合物の定常的なリークが抑制できなくなる傾向にあり、精製処理を行っても、塩化水素としては、やはり半導体用に適さないものとなることが多い。
【００１８】
また、合成樹脂吸着剤の比表面積は、吸着剤として重要な特性であり、通常４００ｍ² ／ｇ以上、好ましくは６００ｍ² ／ｇ以上、さらに好ましくは８００ｍ² ／ｇ以上が有効である。
【００１９】
本発明において使用される合成樹脂吸着剤としては、好ましくは上記に所定の細孔容積や比表面積を有する限り、特に制限はなく、種々の市販品の中から適切なものを選択することができる。なお、合成樹脂吸着剤は、一般に吸着塔に充填して用いられるので、吸着塔への充填効率の良い成形品が選択される。例えば、上記のスチレン−ジビニルベンゼン系では、マクロポアーを有する不溶性の３次元ポリマーで、無置換基型の製品であるダイヤイオンＨＰシリーズ、その特殊処理により比表面積を高めた製品であるセパビーズＳＰ８００シリーズ（以上、すべて三菱化学（株）製）等から選択される。同じシリーズでは、細孔分布の違う各種の銘柄の中から適切なものが選択される。

【００２０】
細孔分布、比表面積の測定法
本発明において、合成樹脂吸着剤の３００Å以下の細孔分布は、窒素吸着法により測定される。しかして、本明細書で表記する、３０〜１００Åの細孔容積の値及び３０〜７０Åの細孔容積の値は、窒素吸着法で測定された細孔分布から算出される。比表面積の値も、また、窒素吸着法の測定結果から算出される。
窒素吸着の値は、カルロエルバ社製ソープトマチック１８００を用い、吸着温度約７７Ｋでの窒素吸着等温線を測定し求めた。すなわち、３０〜１００Å及び３０〜７０Åの２つの細孔容積の値は、測定した窒素吸着等温線データを、クランストン・インクリー法で解析することにより、また、比表面積の値は、同じデータをブルナウア・エメット・テラー法で解析することによって、求められる。
【００２１】
吸着操作
本発明精製方法においては、上記合成樹脂吸着剤、特に所定の細孔容積を有する合成樹脂吸着剤を使用し、有機物、特にアリールアルコール及びその誘導体を含有する塩化水素から、該有機物、特にアリールアルコール及びその誘導体を吸着除去するが、吸着操作の態様には特に制限はない。しかし、塩化水素と合成樹脂吸着剤とを、できるだけ小さな空間で、できるだけ迅速に接触させ、不純物である有機物、特にアリールアルコール及びその誘導体を十分に吸着させることができる操作態様として、吸着塔方式を採用するのが一般的である。
【００２２】
この方式においては、吸着塔に吸着剤である合成樹脂吸着剤を充填し、この塔に有機物、特にアリールアルコール及びその誘導体を含有する塩化水素を、ガス状又は水溶液状で導入し、塩化水素がこの塔を通過する間に合成樹脂吸着剤と接触させ、該有機物、特にアリールアルコール及びその誘導体を合成樹脂吸着剤に吸着させる操作を行う。この操作に際し、一旦吸着された該有機物、特にアリールアルコール及びその誘導体が、後から導入される塩化水素の流れによって合成樹脂吸着剤から著量に離脱する、定常リークを避けるためには、通過するガス又は液のＳＶ（対体積速度）は低い方が好ましい。液の場合は、通常ＳＶ２０／時以下、好ましくは１０／時以下、更に好ましくは５／時以下で行う。ガスの場合は、ＳＶ数十／時のレベルでは非効率で、一般的には数百のオーダーが普通であるが、それでも低い方が吸着効率は良く、通常３００／時以下、好ましくは２００／時以下、更に好ましくは１５０／時以下で行う。
【００２３】
合成樹脂吸着剤への吸着処理に際し、塩化水素を、ガス状で接触させるか、液状で接触させるかは、被吸着成分の状態によっても異なるが、通常、ガス体の場合は前者が、液体の場合は後者が選択される。また、両者を組み合わせて行うこともできる。例えば、ガス状で合成樹脂吸着剤と接触させた後、水に吸収させて液状とした塩化水素を、さらに合成樹脂吸着剤と接触させ、ガス状では吸着されなかった微量成分を吸着する手法も有効である。なお、吸着処理の温度は低い方が好ましく、通常８０℃以下、好ましくは１０〜３０℃で行う。
【００２４】
【実施例】
以下、実施例に従って、本発明を具体的に説明するが、本発明はその要旨を超えない限り、これらに限定されるものではない。
なお、実施例及び比較例における精製処理の評価は、下記の不純物定量法に従って行った。
【００２５】
（１） フェノール及びブロモフェノール濃度（ｎｇ／ｍｌ）：
３５％塩酸を硫酸アンモニウム水溶液で希釈し、クロロホルムで抽出を行った後に濃縮して、ＧＣ−ＭＳ法にて定量を行った。ブロモフェノールは、オルト体、パラ体、２，４−置換体の三種類が検出されたが、ここではこれらを合計した値で示した。
【００２６】
（２） 四塩化炭素濃度（ｎｇ／ｍｌ）：
３５％塩酸に硫酸アンモニウムを溶解させ、Ｓｏｌｉｄ Ｐｈａｓｅ Ｍｉｃｒｏ Ｅｘｔｒａｃｔｉｏｎ法（ＳＰＭＥファイバー：１００μポリジメチルシロキサン／ジメチルシリコン）でヘッドスペースによる抽出を行った後に、ＧＣ−ＭＳ法にて定量を行った。
【００２７】
（３） 金属濃度（μｇ／ｍｌ）：
３５％塩酸中の金属濃度をＩＣＰ−発光装置にて定量した。
【００２８】
製造例
ホスゲンの調製
コークス発生炉ガスを精製して得たＣＯガスと電解により得た塩素ガスとを、活性炭塔に通じ、ＣＯ／Ｃｌ₂ 比＝１．０５、温度４００℃で加圧下反応させ、ホスゲンガスを得た。
【００２９】
塩化水素の調製
得られたホスゲンガスを、フェノール２６．７ｋｇ／時及び触媒ピリジン０．６７ｋｇ／時とともに、１２．９ｋｇ／時の割合で通気し、１５０℃で反応させてジアリールカーボネートを製造する際に、連続的に副生してくる塩化水素ガスを捕集した。
【００３０】
実施例１、２
塩化水素の精製
上記製造例で捕集された塩化水素ガスの一部を、直径５０ｍｍ、高さ１０００ｍｍの円筒型容器内に第１表記載の合成樹脂吸着剤を充填した吸着塔に、ＳＶ１５０／時で通気して気相精製処理を行い、精製された塩化水素ガスを純水に吸収させ、３５％濃度の塩化水素水溶液を得た。
得られた３５％塩酸について、フェノール及びブロモフェノールの濃度、四塩化炭素濃度並びに金属濃度を測定した。結果を第１表に示す。
【００３１】
比較例１
実施例１において、合成樹脂吸着剤吸着塔による精製処理を行わない以外は、実施例１と同様の操作を実施し３５％塩酸を得た。結果を第１表に示す。
【００３２】
【表１】

【００３３】
実施例３、４
比較例１において得られた３５％塩酸を、直径１６ｍｍ、高さ１９５ｍｍの円筒型容器内に第１表記載の合成樹脂吸着剤を充填した吸着塔に、ＳＶ１０／時で通液し、合成樹脂吸着剤による液相精製処理を行い、残留するアリールアルコール誘導体をほぼ完全に除去した。結果を第１表に示す。
【００３４】
比較例２
実施例３において、合成樹脂吸着剤に代えて第１表に示す活性炭を使用した以外は、実施例３と全く同様に液相精製処理を行った。結果を第１表に示す。
【００３５】
実施例５
実施例１において、合成樹脂吸着剤に代えて第１表に示す活性炭を使用した以外は、実施例１と同様に気相精製処理を行い３５％塩酸を得た。この塩酸を、さらに実施例４と全く同様に液相精製処理を行った。結果を第１表に示す。
【００３６】
比較例３
実施例５において、液相精製処理も、合成樹脂吸着剤に代えて第１表に示す活性炭を使用した以外は、実施例５と同様の処理を行った。結果を第１表に示す。
【００３７】
合成樹脂吸着剤を用いた吸着処理により、塩化水素中に不純物として混入しているアリールアルコール及びその誘導体の濃度を著しく低減することができ、さらに活性炭の液相吸着でみられる金属の溶出もなく、得られる塩化水素は優れた品質を有するものであることがわかる。
【００３８】
【発明の効果】
本発明に従い、合成樹脂吸着剤、特に一定の細孔直径の細孔が一定容積以上保持されている合成樹脂吸着剤を使用することにより、塩化水素中に不純物として混入しているアリールアルコール及びその誘導体の濃度を著しく低減することができ、得られる塩化水素は半導体材料の洗浄に使用できるレベルまで向上された、優れた品質を有するものであることが判った。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for purifying an organic substance, particularly hydrogen chloride containing an aryl alcohol and derivatives thereof, using a synthetic resin adsorbent. In particular, the present invention relates to a method for purifying hydrogen chloride that makes it possible to economically purify and reuse a large amount of by-produced hydrogen chloride at the stage of production of diaryl carbonate, which is an intermediate raw material for polycarbonate resin.
[0002]
[Prior art]
Many methods for purifying hydrogen chloride are inherent to the mixed substances. For example, in JP-A-3-265503, activated carbon is used for the purpose of removing chlorinated hydrocarbons having 1 to 3 carbon atoms. Yes. On the other hand, JP-A-8-505833 describes the purification of hydrogen chloride as a by-product in the production of CFCs. Japanese Patent Laid-Open No. 5-262502 introduces a technique for purifying hydrogen chloride mixed with an organosilicon compound used in the manufacture of silicone industrial products with activated carbon having a specific pore diameter.
However, the adsorption removal method using these activated carbons has been investigated by the present inventors. When hydrogen chloride is passed through activated carbon, there is a mixture of metal components eluted from the activated carbon. It became clear that it was necessary to have a new component removal technique.
[0003]
Polycarbonate resin production methods are roughly classified into two, one is a method of interfacial polycondensation using a solvent, and the other is a method of melt polycondensation of diaryl carbonate and diphenol. The present invention relates to the latter and relates to a method for adsorbing and removing organic substances, particularly aryl alcohol and its derivatives, which are inevitably mixed as impurities in by-produced hydrogen chloride at the stage of diaryl carbonate production. is there.
[0004]
[Problems to be solved by the invention]
The production method of diaryl carbonate is also roughly divided into two, one is by transesterification reaction between dialkyl carbonate and aryl alcohol (JP-A-3-291257), and the other is the reaction between phosgene and aryl alcohol. Is known. Also in the latter case, in the method in which an alkali metal or alkaline earth metal compound and a basic nitrogen compound are present as a catalyst (US Pat. No. 3,234,263), the by-produced hydrochloric acid is preferably neutralized by the alkali metal. Therefore, the amount that can be obtained as hydrogen chloride is extremely small.
[0005]
However, when a heterocyclic basic nitrogen compound is used as a catalyst (Japanese Patent Laid-Open No. 58-50977), a phosphorus compound is used (US Pat. No. 5,424,473), an alumina catalyst is used. When used (Japanese Patent Laid-Open No. 9-40617), the amount of by-produced hydrogen chloride is large. Moreover, it is inevitable that aryl alcohol and its derivatives are mixed in by-produced hydrogen chloride, and development of a process for purification by an economically advantageous technique has been desired. Furthermore, derivatization of the aryl alcohol that occurs because the raw material aryl alcohol and phosgene are reacted under an acidic condition is unavoidable, and the removal of this contaminant is hardly noticeable because of its low content. Had been left out.
[0006]
In recent years, the proportion of hydrochloric acid used for cleaning precision components such as wafers and ICs, such as semiconductor materials, has increased, and there has been a strong demand for contaminants contained in hydrogen chloride. There was a strong demand for hydrogen chloride of the desired quality.
[0007]
[Means for Solving the Problems]
In view of the above circumstances, the present inventors have earnestly developed a purification method capable of economically and advantageously purifying and reusing hydrogen chloride containing organic substances, particularly aryl alcohol and derivatives thereof as contaminants. As a result of repeated studies, it has been found that when synthetic substances adsorbents are used when removing the contaminants from hydrogen chloride by adsorption treatment, organic substances, particularly aryl alcohols and derivatives thereof can be reduced to the ppb level. And it confirmed that there was no elution of the metal impurity seen in activated carbon, and came to make this invention.
[0008]
Furthermore, it was also found that if a synthetic resin adsorbent having a pore diameter of 30 to 100 mm and a pore volume of 0.5 ml / g or more is used, aryl alcohol and its derivatives can be adsorbed more efficiently. . In this case, by using a synthetic resin adsorbent in which pores with a certain pore diameter are maintained at a certain volume or more, it is adapted to the molecular size of the mixed aryl alcohol and its derivatives, and a certain proportion of physical adsorption Is to achieve.
In addition, by using a synthetic resin adsorbent in which pores with a certain pore diameter are maintained at a certain volume or more, the adsorbing efficiency of the mixed aryl alcohol and its derivatives is improved, resulting in a semiconductor material, etc. It is intended to provide hydrogen chloride that can withstand the quality used for cleaning of precision members.
[0009]
The gist of the present invention resides in a method for purifying hydrogen chloride containing an organic substance, characterized in that the organic substance is adsorbed and removed from the hydrogen chloride containing the organic substance using a synthetic resin adsorbent. Another gist is that, when adsorbing and removing aryl alcohol and its derivative from hydrogen chloride containing aryl alcohol and its derivative using a synthetic resin adsorbent, a pore diameter of 30 to 100 mm is used as the synthetic resin adsorbent. The present invention resides in a method for purifying hydrogen chloride containing an aryl alcohol and a derivative thereof, wherein a synthetic resin adsorbent having a pore volume of 0.5 ml / g or more is used.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
Impurities Hydrogen chloride to be treated by the purification method of the present invention is a by-product in the so-called Schotten-Baumann reaction in which phosgene and aryl alcohol are reacted at a temperature of room temperature to 200C as described above. Hydrogen chloride. Accordingly, impurities in hydrogen chloride to be removed by the purification method of the present invention are organic substances, particularly aryl alcohols and derivatives thereof, and include various compounds represented by the following general formula.
[0011]
[Chemical 1]

[0012]
In the formula, R ₁ to R ₃ is a hydrogen atom, Cl, halogen atom Br, etc., may have been halogenated, alkyl group having 1 to 30 carbon atoms, an allyl group, an alkenyl group, an alkoxyl group, Some are substituents such as alkoxyalkyl groups, and some of the carbon atoms in these substituents are substituted with other atoms (O, S, N, etc.). In addition, as impurities to be removed by the purification method of the present invention, there are chlorinated hydrocarbons having 1 to 6 carbon atoms, specifically, carbon tetrachloride, chloroform, methylene chloride, dichloroethane, trichloroethane, hexachloroethane, and the like. Can be mentioned. These are considered to be produced and mixed during the production of phosgene.
[0013]
The most commonly detected impurities are aryl alcohols, and the most commonly detected aryl alcohol derivatives are phenols that are Br-substituted at the ortho and / or para positions. Specifically, it is a Br-substituted product such as orthobromophenol, parabromophenol, 2,4-dibromophenol. In the reaction of phosgene and aryl alcohol, these Br substituted products are produced by bromocarbonyl, which is an impurity in phosgene, by substituting Br at the ortho-position and / or para-position hydrogen of the aryl alcohol, and mixed with hydrogen chloride. It is thought that. Note that bromocarbonyl is considered to be caused by bromine present as an impurity in electrolytic chlorine.
[0014]
Among the aryl alcohol derivatives, notable impurities include, in addition to the Br substituents described above, substituents having a large molecular size such as multi-substituted substances. Examples of these substitution products include Cl substitution products, alkyl substitution products, and allyl substitution products. Thus, the Cl-substituted product is a product of chlorinated aryl alcohol by unreacted chlorine in phosgene, and the alkyl-substituted product and allyl-substituted product are originally present as impurities in the aryl alcohol. These are considered to be mixed in hydrogen chloride.
[0015]
Therefore, the impurity level of hydrogen chloride to be purified in the present invention is in a wide range and is usually 30 to 300,000 ng / ml as the content of organic substances, particularly aryl alcohol and its derivatives, in a 35% aqueous solution of hydrogen chloride. However, it can be purified to a level of about 1 ng / ml or less by applying the present invention.
The impurity level of hydrogen chloride purified according to the present invention is 10 ng / ml or less, preferably 5 ng / ml or less, more preferably 1 ng / ml or less as the content of aryl alcohol and its derivatives in a 35% hydrogen chloride aqueous solution. It is. In particular, in applications where quality requirements are severe such as for semiconductors, the content of the Br substitution product is 5 ng / ml or less, preferably 1 ng / ml or less, and more preferably 0.1 ng / ml or less.
[0016]
Synthetic resin adsorbent The synthetic resin adsorbent used in the purification treatment of the present invention is not particularly limited as long as it is a synthetic resin having adsorption ability. Styrene-divinylbenzene, phenolic and methacrylic resins can be exemplified, but styrene-divinylbenzene is preferred. As this synthetic resin adsorbent, the volume of the pores having a pore diameter of usually 30 to 1000 mm, particularly 30 to 100 mm, and more preferably 30 to 70 mm is preferably 0.5 ml / g or more. If this pore volume is insufficient, impurities once adsorbed on the synthetic resin adsorbent at the beginning of adsorption are desorbed by the flow of hydrogen chloride introduced later, and a steady leak phenomenon of a significant amount of aryl alcohol derivative It becomes impossible to reduce the level of the aryl alcohol derivative in the hydrogen chloride after the purification treatment to be less than or equal to this leak amount. That is, the content of the aryl alcohol and its derivative in the 35% hydrogen chloride aqueous solution cannot be made 10 ng / ml or less, which is not suitable for the semiconductor described above.
[0017]
In the present invention, it is more effective to use a synthetic resin adsorbent having a pore volume of 30 to 100 mm and a pore volume of 0.5 ml / g or more as the synthetic resin adsorbent. If the pore volume having a pore diameter in this range is too small, among the above-mentioned aryl alcohol derivatives, there is a tendency that steady leakage of a compound having a large molecular size such as a Br-substituted product or a poly-substituted product cannot be suppressed. Even after purification, hydrogen chloride is often unsuitable for semiconductors.
[0018]
The specific surface area of the synthetic resin adsorbent is an important characteristic as an adsorbent, and is usually 400 m ² / g or more, preferably 600 m ² / g or more, more preferably 800 m ² / g or more.
[0019]
The synthetic resin adsorbent used in the present invention is not particularly limited as long as it has a predetermined pore volume and specific surface area as described above, and an appropriate one can be selected from various commercially available products. . In addition, since the synthetic resin adsorbent is generally used by being packed in an adsorption tower, a molded product having a good packing efficiency in the adsorption tower is selected. For example, in the styrene-divinylbenzene system, an insoluble three-dimensional polymer having macropores, the non-substituent type product, Diaion HP series, and a special surface treatment that increases the specific surface area, the Sepabeads SP800 series ( All of the above are selected from Mitsubishi Chemical Corporation. In the same series, an appropriate one is selected from various brands having different pore distributions.

[0020]
Method for measuring pore distribution and specific surface area In the present invention, the pore distribution of 300 cm or less of the synthetic resin adsorbent is measured by a nitrogen adsorption method. Therefore, the value of the pore volume of 30 to 100 及 び and the value of the pore volume of 30 to 70 す る described in this specification are calculated from the pore distribution measured by the nitrogen adsorption method. The value of the specific surface area is also calculated from the measurement result of the nitrogen adsorption method.
The value of nitrogen adsorption was determined by measuring a nitrogen adsorption isotherm at an adsorption temperature of about 77 K using a Soropmatic 1800 manufactured by Carlo Elba. That is, the values of the two pore volumes of 30 to 100 mm and 30 to 70 mm can be obtained by analyzing the measured nitrogen adsorption isotherm data by the Cranston-Incree method, and the value of the specific surface area can be the same data. It is obtained by analyzing with Brunauer-Emmett-Teller method.
[0021]
Adsorption operation In the purification method of the present invention, the above-mentioned synthetic resin adsorbent, particularly a synthetic resin adsorbent having a predetermined pore volume, is used, from hydrogen chloride containing organic substances, in particular aryl alcohol and derivatives thereof, The organic substance, particularly aryl alcohol and its derivatives are removed by adsorption, but the mode of the adsorption operation is not particularly limited. However, as an operation mode in which hydrogen chloride and a synthetic resin adsorbent are brought into contact with each other as quickly as possible in a space as small as possible and organic substances as impurities, particularly aryl alcohol and derivatives thereof, can be sufficiently adsorbed, an adsorption tower system is used. Generally adopted.
[0022]
In this method, a synthetic resin adsorbent as an adsorbent is packed in an adsorption tower, and hydrogen chloride containing an organic substance, particularly aryl alcohol and its derivative, is introduced into the tower in the form of a gas or an aqueous solution. While passing through this tower, it is brought into contact with a synthetic resin adsorbent, and an operation for adsorbing the organic substance, particularly aryl alcohol and its derivative, onto the synthetic resin adsorbent is performed. In this operation, the organic substances once adsorbed, in particular aryl alcohol and derivatives thereof, pass through in order to avoid a steady leak in which a large amount of hydrogen chloride is introduced from the synthetic resin adsorbent by a flow of hydrogen chloride introduced later. The SV (vs. volume velocity) of the gas or liquid is preferably low. In the case of a liquid, it is usually carried out at SV20 / hour or less, preferably 10 / hour or less, more preferably 5 / hour or less. In the case of gas, it is inefficient at the level of several tens of hours / hour of SV, and is generally in the order of several hundreds. However, the lower one, the better the adsorption efficiency, usually 300 / hour or less, preferably 200 / hour. Or less, more preferably 150 / hour or less.
[0023]
In the adsorption treatment to the synthetic resin adsorbent, whether hydrogen chloride is contacted in a gaseous state or in a liquid state depends on the state of the adsorbed component, but in the case of a gas body, the former is usually In the case, the latter is selected. Moreover, it can also carry out combining both. For example, after contacting gaseous synthetic resin adsorbent, hydrogen chloride absorbed in water and brought into liquid form is further contacted with synthetic resin adsorbent to adsorb trace components that were not adsorbed gaseously. It is valid. In addition, the one where the temperature of adsorption processing is lower is preferable, and it is 80 degrees C or less normally, Preferably it performs at 10-30 degreeC.
[0024]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated concretely according to an Example, this invention is not limited to these, unless the summary is exceeded.
In addition, evaluation of the refinement | purification process in an Example and a comparative example was performed in accordance with the following impurity determination method.
[0025]
(1) Phenol and bromophenol concentrations (ng / ml):
35% hydrochloric acid was diluted with an aqueous ammonium sulfate solution, extracted with chloroform, concentrated, and quantified by the GC-MS method. Three types of bromophenol, ortho, para, and 2,4-substituted, were detected, and are shown here as a total value.
[0026]
(2) Carbon tetrachloride concentration (ng / ml):
Ammonium sulfate was dissolved in 35% hydrochloric acid, and extraction with a head space was performed by a solid phase micro extraction method (SPME fiber: 100 μpolydimethylsiloxane / dimethylsilicone), followed by quantification by a GC-MS method.
[0027]
(3) Metal concentration (μg / ml):
The metal concentration in 35% hydrochloric acid was quantified with an ICP-light emitting device.
[0028]
Production example
The CO gas Preparation <br/> coke producer gas phosgene obtained is purified and the chlorine gas obtained by electrolysis, leading to the activated carbon column, CO / Cl ₂ ratio = 1.05, under pressure at a temperature 400 ° C. Reaction was performed to obtain phosgene gas.
[0029]
Preparation of hydrogen chloride The obtained phosgene gas was aerated at a rate of 12.9 kg / hr together with 26.7 kg / hr of phenol and 0.67 kg / hr of catalyst pyridine, and reacted at 150 ° C to give diaryl carbonate. During production, hydrogen chloride gas continuously produced as a by-product was collected.
[0030]
Examples 1 and 2
Purification of hydrogen chloride An adsorption tower in which a part of the hydrogen chloride gas collected in the above production example is filled with a synthetic resin adsorbent described in Table 1 in a cylindrical container having a diameter of 50 mm and a height of 1000 mm. Then, a gas phase purification treatment was performed by aeration at SV 150 / hour, and the purified hydrogen chloride gas was absorbed into pure water to obtain a 35% aqueous hydrogen chloride solution.
About the obtained 35% hydrochloric acid, the concentration of phenol and bromophenol, the concentration of carbon tetrachloride, and the concentration of metal were measured. The results are shown in Table 1.
[0031]
Comparative Example 1
In Example 1, 35% hydrochloric acid was obtained by performing the same operation as in Example 1 except that the purification treatment by the synthetic resin adsorbent adsorption tower was not performed. The results are shown in Table 1.
[0032]
[Table 1]

[0033]
Examples 3 and 4
The 35% hydrochloric acid obtained in Comparative Example 1 was passed through an adsorption tower filled with the synthetic resin adsorbent shown in Table 1 in a cylindrical container having a diameter of 16 mm and a height of 195 mm at a rate of SV10 / hour. Liquid phase purification treatment with an adsorbent was performed to remove the remaining aryl alcohol derivative almost completely. The results are shown in Table 1 .
[0034]
Comparative Example 2
In Example 3, except for using activated carbon shown in Table 1 in place of the synthetic resin adsorbent, was carried out in exactly the same way as in the liquid phase purification treatment as in Example 3. The results are shown in Table 1 .
[0035]
Example 5
In Example 1, gas phase purification treatment was performed in the same manner as in Example 1 except that the activated carbon shown in Table 1 was used instead of the synthetic resin adsorbent to obtain 35% hydrochloric acid. This hydrochloric acid was further subjected to liquid phase purification treatment in exactly the same manner as in Example 4. The results are shown in Table 1 .
[0036]
Comparative Example 3
In Example 5, the liquid phase purification treatment was also performed in the same manner as in Example 5 except that activated carbon shown in Table 1 was used instead of the synthetic resin adsorbent. The results are shown in Table 1 .
[0037]
Adsorption treatment using a synthetic resin adsorbent can significantly reduce the concentration of aryl alcohol and its derivatives mixed as impurities in hydrogen chloride, and there is no metal elution observed in liquid phase adsorption of activated carbon. It can be seen that the obtained hydrogen chloride has excellent quality.
[0038]
【The invention's effect】
According to the present invention, by using a synthetic resin adsorbent, particularly a synthetic resin adsorbent in which pores having a certain pore diameter are maintained at a certain volume or more, an aryl alcohol mixed as an impurity in hydrogen chloride and its It has been found that the concentration of the derivative can be significantly reduced and the resulting hydrogen chloride is of excellent quality, improved to a level that can be used for cleaning semiconductor materials.

Claims (4)

In the method for purifying hydrogen chloride, wherein the organic substance is adsorbed and removed from the hydrogen chloride containing the organic substance using a synthetic resin adsorbent, the organic substance is an aryl alcohol and a derivative thereof, and the synthetic resin adsorbent is 30 to 100%. A method for purifying hydrogen chloride containing an organic substance, wherein the volume of pores having a pore diameter is 0.5 ml / g or more.   2. The method for purifying hydrogen chloride containing an organic substance according to claim 1, wherein the synthetic resin adsorbent has a pore volume of 30 to 70 mm and a pore volume of 0.5 ml / g or more. In the adsorption removal, an adsorption tower is filled with a synthetic resin adsorbent, hydrogen chloride containing the organic substance is introduced into the tower in the form of a gas or an aqueous solution, and the synthetic resin is adsorbed while hydrogen chloride passes through the tower. method for purifying the hydrogen chloride containing an organic material according to claim 1 or 2, characterized in Rukoto done by contacting the agent. Hydrogen chloride introduced into the adsorption tower filled with the synthetic resin adsorbent was obtained by passing the adsorption tower filled with activated carbon and performing a gas phase purification treatment, and absorbing the purified hydrogen chloride gas into pure water. The method for purifying hydrogen chloride containing an organic substance according to claim 3, which is an aqueous solution.