JP3544154B2

JP3544154B2 - Method for producing hexaammineiridium nitrate solution

Info

Publication number: JP3544154B2
Application number: JP28901899A
Authority: JP
Inventors: 知史市石; 綾子佐藤
Original assignee: Tanaka Kikinzoku Kogyo KK
Current assignee: Tanaka Kikinzoku Kogyo KK
Priority date: 1999-10-12
Filing date: 1999-10-12
Publication date: 2004-07-21
Anticipated expiration: 2019-10-12
Also published as: JP2001106535A

Description

【０００１】
【発明の属する技術分野】
本発明は、ヘキサアンミンイリジウム硝酸塩（以下「ＨＡＩｒＴＮ」という。）溶液の製造方法に関するものである。
【０００２】
【従来の技術】
従来、ＨＡＩｒＴＮ溶液を製造するには煩雑な操作方法をとらざるを得なかった。例えば、まず塩化イリジウム酸カリウムの結晶を水で溶解し、これに塩化アンモニウムと炭酸アンモニウムを加えて湯浴上で加熱還流して反応させ、得られた黄褐色沈殿を濾過し、３ＮＨＣｌで抽出して不純物を除去した後、熱水で溶解し、濾過し、濾液を濃縮後濃塩酸を加えて［ＩｒＣｌ（ＮＨ_３）_５］Ｃｌ_２の沈殿を得る。該沈殿を、アンモニア水に入れ、封管中で１４０℃４８時間加熱後、濾過し、濾液を蒸発乾固する。さらに湯浴上で１時間加熱して、アクアペンタアンミン塩を分解する。これを充分量の希塩酸に溶解し、等容積の３０％硝酸を加えて［Ｉｒ（ＮＨ_３）_６］（ＮＯ_３）_３の白色結晶を得る。最後に１５％硝酸とエタノールエーテルで洗浄し、乾燥後水に溶かす、という煩雑な方法が行われている。しかも、上記の方法では、操作面での煩雑さの他に、ＮＨ_４ＣｌやＨＣｌといった不純物が混入するという問題点もあった。
【０００３】
【発明が解決しようとする課題】
本発明は、上記従来法の欠点を解決するためになされたものであり、簡略な操作で、不純物の少ないＨＡＩｒＴＮ溶液を製造する方法を提供することを目的とする。
【０００４】
【課題を解決するための手段】
本発明は、塩化イリジウム（ＩＩＩ）酸溶液に過剰のアンモニア水を加え、加圧下で加熱して反応させてヘキサアンミンイリジウム（ＩＩＩ）クロライド溶液を合成し、該合成した溶液を加熱して弱アルカリ性としてから陰イオン交換樹脂と接触させた後、硝酸を加えることを特徴とするＨＡＩｒＴＮ溶液の製造方法である。
前記陰イオン交換樹脂は前もってＯＨイオン型に処理したものを用い、接触させる陰イオン交換樹脂量は理論交換量の２倍以上とするのが望ましい。
【０００５】
【発明の実施の形態】
以下、発明を詳細に説明する。
【０００６】
中間体としての、ヘキサアンミンイリジウム（ＩＩＩ）クロライド溶液を合成するには、塩化イリジウム（ＩＩＩ）酸溶液に過剰のアンモニア水を加え、加圧反応させることのできる容器中、例えばオートクレーブ中で１．５〜５ｋｇ／ｃｍ^２の圧力下で１００〜１５０℃に加熱して１昼夜以上その状態を保持して反応させれば良い。
【０００７】
次いで、過剰に加えたアンモニアを除去するために９０〜９８℃の温度で加熱し、ヘキサアンミンイリジウム（ＩＩＩ）クロライド溶液のｐＨが７．５〜９．０になったところで加熱を止め、室温まで冷却することでヘキサアンミンイリジウム（ＩＩＩ）クロライド溶液を合成できる。ｐＨを７．５〜９．０の弱アルカリ性にしておくのは以下の操作として陰イオン交換樹脂との接触の際に安定した陰イオン交換を完結させるためである。
【０００８】
本発明において使用する陰イオン交換樹脂としては強塩基陰イオン交換樹脂が好ましく、例えば三菱化成工業製ダイヤイオンＳＡ１０Ａ、またはダイヤイオンＳＡ１２Ａを使用できる。
合成したヘキサアンミンイリジウム（ＩＩＩ）クロライド溶液と接触させる前に、陰イオン交換樹脂をＯＨイオン型にしておく方法は、例えば１ｌの陰イオン交換樹脂をカラムに充填しておき、５％前後の水酸化ナトリウム溶液３ｌを空間速度ＳＶ＝２で通液し、次いで純水を同じくＳＶ＝２で通液して流出液のｐＨが７になるまで純水を通液することが必要である。純水を通液してｐＨ＝７まで行うことにより、ナトリウムイオンの除去が可能となるからである。
【０００９】
ＯＨイオン型にした陰イオン交換樹脂にヘキサアンミンイリジウム（ＩＩＩ）クロライド溶液を接触させる方法は、例えばビーカ内で混合して攪拌して接触させてもよいが、前記ＯＨイオン型にする操作と同様、カラムに充填した陰イオン交換樹脂層にヘキサアンミンイリジウム（ＩＩＩ）クロライド溶液を通液させる方法が簡便であり分離等の手間も省けるもので、連続操作を行う上から、より好ましいものである。
また、通液する速度は空間速度ＳＶ＝０．１ｈｒ^−１〜０．５ｈｒ^−１とすればよく、より好ましくはＳＶ＝０．２ｈｒ^−１である。
【００１０】
なお、陰イオン交換樹脂の量を陰イオン交換理論量の２倍以上とするのは、陰イオン交換平衡との関係によるもので、該イリジウム化合物の塩素イオンとＯＨイオンとの交換を完全に行わせるために欠くことのできないポイントである。
よって、陰イオン交換樹脂に通液するヘキサアンミンイリジウム（ＩＩＩ）クロライド溶液の濃度は特に限定されるものではないが、薄い液では濃縮操作が必要になり、濃厚液では通液の際に結晶が発生する可能性があり、好ましくは４０ｇ／ｌ〜１００ｇ／ｌに調製したものがよい。
【００１１】
こうして得られた溶液に硝酸を加え、ｐＨを７以下に調整することにより、ＨＡＩｒＴＮ溶液が製造される。
【００１２】
以上の方法により、不純物の混入が極めて少ないＨＡＩｒＴＮ溶液を製造することができるものである。
【００１３】
【実施例】
以下、本発明に係わる実施例を記載するが、該実施例は本発明を限定するものではない。
【００１４】
【実施例１】
塩化イリジウム酸溶液（Ｉｒとして２０ｇ含有する）１２０ｍｌにアンモニア水（２８％）４００ｍｌを加え、オートクレーブ中で圧力を１．５〜５ｋｇ／ｃｍ^２、加熱温度１３０℃、攪拌を５００ｒｐｍとして２４時間反応させた。
次いで、反応後の溶液を冷却して濾過し、濾過液をビーカに入れ湯浴で９５℃に加熱して濾過液のｐＨが８．７となったところで加熱を止め、室温まで冷却した。
次いで、冷却した濾過液を前もってＯＨイオン型にした強塩基陰イオン交換樹脂（三菱化成工業製：ダイヤイオンＳＡ１０Ａ）４ｌを直径５０ｍｍのガラス製カラムに充填した層に、空間速度ＳＶ＝０．２ｈｒ^−１で通液した。
通液した後、陰イオン交換樹脂層に純水をＳＶ＝０．２ｈｒ^−１で通液し押出洗浄してヘキサアンミンＩｒ水酸化物溶液を２．５ｌ得た。この溶液を９５℃に加熱して、余分なアンモニアを蒸発させて濃縮した後、６０％硝酸１９ｍｌを加え、ｐＨ７に調整し、Ｉｒ濃度で２０ｇ／ｌであるＨＡＩｒＴＮ溶液を８００ｍｌを得た。該ＨＡＩｒＴＮ溶液の２ｍｌを分取し、１／１０Ｎ塩酸で電位差滴定したところ滴定に要した塩酸量からイリジウム１ｍｏｌに対してＯＨイオンがほぼ３ｍｏｌとなりＨＡＩｒＴＮであることが確認された。
なお、該溶液中の塩素イオン濃度は１００ｍｇ／ｌ以下であった。
【００１５】
【実施例２】
塩化イリジウム酸溶液（Ｉｒとして２０ｇ含有する）１２０ｍｌにアンモニア水（２８％）４００ｍｌを加え、オートクレーブ中で圧力を１．５〜５ｋｇ／ｃｍ^２、加熱温度１３０℃、攪拌を５００ｒｐｍとして４８時間反応させた。
次いで、反応後の溶液を冷却して濾過し、濾過液をビーカに入れ湯浴で９５℃に加熱して濾過液のｐＨが８．０となったところで加熱を止め、室温まで冷却した。
次いで、冷却した濾過液を前以ってＯＨイオン型にした強塩基陰イオン交換樹脂（三菱化成工業製：ダイヤイオンＳＡ１０Ａ）４ｌを直径５０ｍｍのガラス製カラムに充填した層に、空間速度ＳＶ＝０．２ｈｒ^−１で通液した。
通液した後、陰イオン交換樹脂層に純水をＳＶ＝０．２ｈｒ^−１で通液し押出洗浄してヘキサアンミンＩｒ水酸化物溶液を２．５ｌ得た。この溶液を９５℃に加熱して、余分なアンモニアを蒸発させて濃縮した後、６０％硝酸２５ｍｌを加え、ｐＨ７に調整し_、Ｉｒ濃度で２０ｇ／ｌのＨＡＩｒＴＮ溶液１０００ｍｌを得た。
該ＨＡＩｒＴＮ溶液の２ｍｌを分取し、１／１０Ｎ塩酸で電位差滴定したところ滴定に要した塩酸量からイリジウム１ｍｏｌに対してＯＨイオンがほぼ３ｍｏｌとなりＨＡＩｒＴＮであることが確認された。
なお、該溶液中の塩素イオン濃度は１００ｍｇ／ｌ以下であった。
【００１６】
【従来例】
塩化イリジウム酸カリウム（Ｉｒとして２０ｇ含有する）の結晶８８ｇを水１１８０ｍｌに溶解し、これに塩化アンモニウム５８７ｇと炭酸アンモニウム８８０ｇを加えて９０℃の湯浴上で加熱還流して反応させた。得られた黄褐色沈殿を濾過し、３ＮＨＣｌで抽出して不純物の［ＩｒＣｌ_２（ＮＨ_３）_４］Ｃｌを除去した後、熱水で溶解し、濾過し、濾液を濃縮後濃塩酸７３３ｍｌを加えて［ＩｒＣｌ（ＮＨ_３）_５］Ｃｌ_２の沈殿を得た。該沈殿を、アンモニア水に入れ、封管中で１４０℃４８時間加熱後、濾過し、濾液を蒸発乾固した。さらに湯浴上で１時間加熱して、アクアペンタアンミン塩を分解した。これを充分量の希塩酸に溶解し、等容積の３０％硝酸を加えて［Ｉｒ（ＮＨ_３）_６］（ＮＯ_３）_３の白色結晶を得た。最後に１５％硝酸とエタノールエーテルで洗浄し、乾燥後水に溶かすことにより、ＨＡＩｒＴＮ溶液を得た。
【００１７】
【発明の効果】
以上の説明で明らかなように、従来法では一旦［ＩｒＣｌ（ＮＨ_３）_５］Ｃｌ_２の沈殿を得てから濾過するという固液分離の工程が入っていたため、操作が煩雑であり、かつ不純物の混入も起こり易かった。これに対して、本発明の方法によれば、目的物が全工程を通して液体状態で扱えるため、操作の自動化が行い易く、しかも溶液中の塩素イオンを極めて少なくでき、溶液中の不純物の少ない安定したものが製造できるという優れた特徴を有するものである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a hexaammineiridium nitrate (hereinafter, referred to as “HAIrTN”) solution.
[0002]
[Prior art]
Conventionally, a complicated operation method had to be taken to produce a HAIrTN solution. For example, first, potassium chloride iridate crystals are dissolved in water, ammonium chloride and ammonium carbonate are added thereto, and the mixture is heated and refluxed on a hot water bath to react. The resulting tan precipitate is filtered and extracted with 3N HCl. After removing impurities, the residue is dissolved in hot water, filtered, and the filtrate is concentrated and concentrated hydrochloric acid is added to obtain a precipitate of [IrCl (NH ₃ ) ₅ ] Cl ₂ . The precipitate is placed in aqueous ammonia, heated in a sealed tube at 140 ° C. for 48 hours, filtered, and the filtrate is evaporated to dryness. Further, it is heated on a hot water bath for one hour to decompose the aquapentaammine salt. This is dissolved in a sufficient amount of diluted hydrochloric acid, and an equal volume of 30% nitric acid is added to obtain white crystals of [Ir (NH ₃ ) ₆ ] (NO ₃ ) ₃ . Finally, a complicated method of washing with 15% nitric acid and ethanol ether, drying and dissolving in water has been performed. Moreover, in the above method, there is a problem that impurities such as NH ₄ Cl and HCl are mixed, in addition to complicated operation.
[0003]
[Problems to be solved by the invention]
The present invention has been made to solve the above-mentioned drawbacks of the conventional method, and an object of the present invention is to provide a method for producing a HAIrTN solution containing few impurities by a simple operation.
[0004]
[Means for Solving the Problems]
According to the present invention, an aqueous solution of ammonia is added to an iridium chloride (III) chloride solution, and the mixture is heated and reacted under pressure to synthesize a hexaammine iridium (III) chloride solution. A method for producing a HAIrTN solution, wherein nitric acid is added after contacting with an anion exchange resin.
It is desirable that the anion exchange resin be treated in advance as an OH ion type, and the amount of the anion exchange resin to be contacted be at least twice the theoretical exchange amount.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
[0006]
In order to synthesize a hexaammine iridium (III) chloride solution as an intermediate, an excess of aqueous ammonia is added to a solution of iridium (III) chloride and an aqueous ammonia is added. The reaction may be carried out by heating to 100 to 150 ° C. under a pressure of 5 to 5 kg / cm ² and maintaining the state for one day or more.
[0007]
Then, the mixture was heated at a temperature of 90 to 98 ° C. in order to remove excessively added ammonia. When the pH of the hexaammineiridium (III) chloride solution reached 7.5 to 9.0, the heating was stopped, and the mixture was cooled to room temperature. By cooling, a hexaammine iridium (III) chloride solution can be synthesized. The reason for keeping the pH weakly alkaline at 7.5 to 9.0 is to complete stable anion exchange at the time of contact with an anion exchange resin as the following operation.
[0008]
As the anion exchange resin used in the present invention, a strong base anion exchange resin is preferable. For example, Diaion SA10A or Diaion SA12A manufactured by Mitsubishi Kasei Kogyo can be used.
Before contacting the synthesized hexaammine iridium (III) chloride solution with the OH ion type anion exchange resin, for example, a column is filled with 1 liter of anion exchange resin, and about 5% of water is added. It is necessary to pass 3 l of sodium oxide solution at a space velocity of SV = 2, and then pass pure water also at SV = 2 to pass pure water until the pH of the effluent becomes 7. This is because sodium ions can be removed by passing pure water through to pH = 7.
[0009]
The method of contacting the hexaammine iridium (III) chloride solution with the OH ion type anion exchange resin may be, for example, mixing in a beaker and contacting with stirring, but is the same as the above-mentioned operation of converting to the OH ion type. The method of passing a hexaammine iridium (III) chloride solution through an anion exchange resin layer packed in a column is simple and can save labor such as separation, and is more preferable in terms of performing a continuous operation.
Also, the rate of liquid passing space velocity ^SV = ^0.1hr ^-1 ^~0.5hr -1 Tosureba well, and more preferably from SV = 0.2 hr ^-1.
[0010]
The reason that the amount of the anion exchange resin is twice or more the theoretical amount of the anion exchange is due to the relationship with the anion exchange equilibrium, and the exchange of chloride ions and OH ions of the iridium compound is completely performed. It is an indispensable point to make it.
Therefore, the concentration of the hexaammine iridium (III) chloride solution passed through the anion exchange resin is not particularly limited, but a thin solution requires a concentration operation, and a concentrated solution requires crystals to pass through. It may be generated, and preferably prepared at 40 g / l to 100 g / l.
[0011]
By adding nitric acid to the solution thus obtained and adjusting the pH to 7 or less, a HAIrTN solution is produced.
[0012]
By the above method, it is possible to produce a HAIrTN solution with very little impurities.
[0013]
【Example】
Hereinafter, examples according to the present invention will be described, but the examples do not limit the present invention.
[0014]
Embodiment 1
400 ml of aqueous ammonia (28%) was added to 120 ml of a chlorinated iridium acid solution (containing 20 g as Ir), and the mixture was reacted in an autoclave at a pressure of 1.5 to 5 kg / cm ² , a heating temperature of 130 ° C, and stirring at 500 rpm for 24 hours. Was.
Next, the solution after the reaction was cooled and filtered, and the filtrate was placed in a beaker and heated to 95 ° C. in a hot water bath. When the pH of the filtrate reached 8.7, the heating was stopped and the mixture was cooled to room temperature.
Then, a layer filled with a glass column having a diameter of 50 mm filled with 4 l of a strong base anion exchange resin (Diaion SA10A, manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) in which the cooled filtrate was previously converted to an OH ion type was charged with a space velocity SV = 0.2 hr. ^The solution was passed at ^-1 .
After the liquid was passed, pure water was passed through the anion exchange resin layer at SV = 0.2 hr ⁻¹ and extruded and washed to obtain 2.5 l of a hexaammine Ir hydroxide solution. The solution was heated to 95 ° C., concentrated by evaporating excess ammonia, and then adjusted to pH 7 by adding 19 ml of 60% nitric acid to obtain 800 ml of a HAIrTN solution having an Ir concentration of 20 g / l. 2 ml of the HAIrTN solution was sampled and subjected to potentiometric titration with 1 / 10N hydrochloric acid. From the amount of hydrochloric acid required for the titration, OH ions were almost 3 mol per 1 mol of iridium, and it was confirmed that the HAIrTN was HAIrTN.
Note that the chloride ion concentration in the solution was 100 mg / l or less.
[0015]
Embodiment 2
400 ml of aqueous ammonia (28%) is added to 120 ml of a iridic chloride solution (containing 20 g as Ir), and the reaction is carried out in an autoclave at a pressure of 1.5 to 5 kg / cm ² , a heating temperature of 130 ° C. and stirring at 500 rpm for 48 hours. Was.
Next, the solution after the reaction was cooled and filtered, and the filtrate was placed in a beaker and heated to 95 ° C. in a hot water bath. When the pH of the filtrate reached 8.0, the heating was stopped and the solution was cooled to room temperature.
Next, a layer filled with a glass column having a diameter of 50 mm was filled with 4 l of a strong base anion exchange resin (manufactured by Mitsubishi Kasei Kogyo Co., Ltd .: Diaion SA10A) in which the cooled filtrate was previously converted to an OH ion form. The solution was passed at 0.2 hr ^-1 .
After the liquid was passed, pure water was passed through the anion exchange resin layer at SV = 0.2 hr ⁻¹ and extruded and washed to obtain 2.5 l of a hexaammine Ir hydroxide solution. The solution was heated to 95 ° C. and concentrated by evaporating excess ammonia. The solution was adjusted to pH 7 by adding 25 ml of 60% nitric acid to obtain 1000 ml of an HIRrTN solution having _an Ir concentration of 20 g / l.
2 ml of the HAIrTN solution was sampled and subjected to potentiometric titration with 1 / 10N hydrochloric acid. From the amount of hydrochloric acid required for the titration, OH ions were almost 3 mol per 1 mol of iridium, and it was confirmed that the HAIrTN was HAIrTN.
Note that the chloride ion concentration in the solution was 100 mg / l or less.
[0016]
[Conventional example]
88 g of potassium chloride iridate crystals (containing 20 g as Ir) were dissolved in 1180 ml of water, to which 587 g of ammonium chloride and 880 g of ammonium carbonate were added, and the mixture was heated and refluxed on a 90 ° C. water bath to cause a reaction. The resulting tan precipitate was filtered and extracted with 3N HCl to remove impurities [IrCl ₂ (NH ₃ ) ₄ ] Cl, dissolved in hot water, filtered, concentrated, and concentrated, and 733 ml of concentrated hydrochloric acid was added. Thus, a precipitate of [IrCl (NH ₃ ) ₅ ] Cl ₂ was obtained. The precipitate was placed in aqueous ammonia, heated in a sealed tube at 140 ° C. for 48 hours, filtered, and the filtrate was evaporated to dryness. Further, the mixture was heated on a hot water bath for 1 hour to decompose the aquapentaammine salt. This was dissolved in a sufficient amount of diluted hydrochloric acid, and an equal volume of 30% nitric acid was added to obtain white crystals of [Ir (NH ₃ ) ₆ ] (NO ₃ ) ₃ . Finally, it was washed with 15% nitric acid and ethanol ether, dried and dissolved in water to obtain a HAIrTN solution.
[0017]
【The invention's effect】
As is clear from the above description, the conventional method includes a solid-liquid separation step of once obtaining a precipitate of [IrCl (NH ₃ ) ₅ ] Cl ₂ and then filtering the precipitate, so that the operation is complicated and impurities Was easy to occur. On the other hand, according to the method of the present invention, the target substance can be handled in a liquid state throughout the entire process, so that the operation can be easily automated, and furthermore, the chlorine ions in the solution can be extremely reduced, and the solution has a small amount of impurities. It has an excellent feature that it can be manufactured.

Claims

An excess of aqueous ammonia is added to the iridium (III) chloride solution, and the mixture is heated and reacted under pressure to synthesize a hexaammine iridium (III) chloride solution. After heating the solution to make it weakly alkaline, an anion A method for producing a hexaammineiridium nitrate solution, which comprises adding nitric acid after contacting with an exchange resin.

The method for producing a hexaammineiridium nitrate solution according to claim 1, wherein the anion exchange resin has been previously treated to an OH ion type, and the amount of the anion exchange resin to be contacted is twice or more the theoretical exchange amount.