JP2002274847A - Method of preparing needle zinc oxide - Google Patents
Method of preparing needle zinc oxideInfo
- Publication number
- JP2002274847A JP2002274847A JP2001077096A JP2001077096A JP2002274847A JP 2002274847 A JP2002274847 A JP 2002274847A JP 2001077096 A JP2001077096 A JP 2001077096A JP 2001077096 A JP2001077096 A JP 2001077096A JP 2002274847 A JP2002274847 A JP 2002274847A
- Authority
- JP
- Japan
- Prior art keywords
- zinc oxide
- zinc
- reaction
- urea
- acicular
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は針状酸化亜鉛の製法
に関し、より詳細には、炭酸亜鉛等を熱分解して酸化亜
鉛を製造する方法の如く高温処理を必要とすることな
く、高純度の針状酸化亜鉛を簡単に製造することのでき
る方法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 producing acicular zinc oxide, and more particularly, to a method for producing zinc oxide by pyrolysis of zinc carbonate or the like, which does not require high-temperature treatment and is highly purified. And a method for easily producing the acicular zinc oxide.
【０００２】[0002]
【従来の技術】酸化亜鉛は、工業用基礎材料として、例
えばゴムの加硫促進助剤、塗料用の顔料、医薬品、合成
樹脂などへの添加剤など、あるいは更に電子写真用感光
剤や、フェライト、バリスタ、蛍光体の如き電子部品材
料などとして様々の分野に幅広く使用されている。これ
らの用途のうち特に電子部品材料として使用する場合
は、鉛やカドミウムなどの有害金属成分の含量が少ない
高純度のものが求められている。また最近、針状、殊に
針長が１μm程度以上の針状酸化亜鉛が上記用途に適し
た性能を示すことが確認されるに及び、針状酸化亜鉛の
製造法についても幾つかの方法が提示されている。2. Description of the Related Art Zinc oxide is used as an industrial basic material, for example, as a vulcanization accelerating aid for rubber, a pigment for paints, an additive to pharmaceuticals, synthetic resins, etc., or a photosensitive agent for electrophotography or ferrite. It is widely used in various fields as a material for electronic parts such as varistors and phosphors. Among these uses, particularly when used as electronic component materials, high-purity materials having a low content of harmful metal components such as lead and cadmium are required. Recently, it has been confirmed that acicular zinc oxide, in particular, acicular zinc oxide having a needle length of about 1 μm or more exhibits performance suitable for the above-mentioned applications, and several methods for producing acicular zinc oxide have been developed. Has been presented.
【０００３】一方酸化亜鉛の代表的な製法としては、フ
ランス法やアメリカ法の如き亜鉛蒸気を酸化して酸化亜
鉛を得る乾式法と、水溶性亜鉛塩を炭酸または炭酸塩と
反応させて塩基性炭酸亜鉛の如き亜鉛塩を中間体として
製造し、これを焼成して酸化亜鉛を得る湿式法がある。
このうち乾式法によって得られる酸化亜鉛は、団塊状の
粉末として得られることが多く、製造条件によっては針
状のものを得ることもできるが、原料となる金属亜鉛中
に混在する鉛やカドミウムが酸化物として１０００ppm
程度混入してくるため純度に問題があり、高純度が求め
られる電子部品材料としての適性を欠く。また湿式法に
よって得られる酸化亜鉛は比較的粒径の揃ったほぼ球形
の粉末が殆どであり、針状物として得る方法は殆ど実用
化されていない。On the other hand, typical methods for producing zinc oxide include a dry method of oxidizing zinc vapor to obtain zinc oxide, such as the French method and the American method, and a basic method of reacting a water-soluble zinc salt with carbonic acid or carbonate to form a basic method. There is a wet method in which a zinc salt such as zinc carbonate is produced as an intermediate, which is calcined to obtain zinc oxide.
Of these, zinc oxide obtained by the dry method is often obtained as a nodular powder, and depending on the production conditions, a needle-like one can be obtained, but lead and cadmium mixed in the metallic zinc as the raw material are 1000ppm as oxide
To this extent, there is a problem in purity due to the contamination, and it is not suitable as an electronic component material requiring high purity. In addition, most of zinc oxide obtained by a wet method is relatively spherical powder having a relatively uniform particle size, and a method of obtaining an acicular material has hardly been put to practical use.
【０００４】また特殊な方法として特開平１−２５２６
００号公報には、表面に酸化亜鉛皮膜を形成した亜鉛粉
末を加熱し、徐々に亜鉛蒸気を発生させてこれを酸化す
ることにより針状酸化亜鉛を製造する方法が開示されて
いる。しかし、この方法は生産性が非常に悪く、しかも
原料となる金属亜鉛中に含まれる鉛やカドミウムが不純
物源となって相当量の酸化鉛や酸化カドミウムが混入し
てくるため、酸化亜鉛としての純度を下げる大きな原因
になってくる。しかも亜鉛蒸気の発生やその酸化に高温
を要するので、耐熱設備のための設備負担が強いられ
る。As a special method, Japanese Patent Application Laid-Open No. 1-2526
No. 00 discloses a method for producing acicular zinc oxide by heating zinc powder having a zinc oxide film formed on its surface, gradually generating zinc vapor, and oxidizing the zinc vapor. However, this method is very poor in productivity, and lead and cadmium contained in the metal zinc, which is a raw material, becomes an impurity source and a considerable amount of lead oxide and cadmium oxide is mixed therein. This is a major cause of lowering the purity. In addition, since high temperature is required for generation of zinc vapor and its oxidation, equipment burden for heat-resistant equipment is imposed.
【０００５】[0005]
【発明が解決しようとする課題】本発明は上記の様な事
情に着目してなされたものであって、その目的は、高純
度の針状酸化亜鉛を、簡単な設備および方法で効率よく
製造することのできる方法を提供することにある。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to efficiently produce high-purity acicular zinc oxide with a simple facility and method. It is to provide a method that can do this.
【０００６】[0006]
【課題を解決するための手段】上記課題を解決すること
のできた本発明に係る針状酸化亜鉛の製法とは、水溶性
亜鉛塩と尿素を含む水溶液を加熱し、該水溶液から針状
の酸化亜鉛を析出させるところに要旨を有している。Means for Solving the Problems The method for producing acicular zinc oxide according to the present invention, which can solve the above-mentioned problems, comprises heating an aqueous solution containing a water-soluble zinc salt and urea, and converting the aqueous solution into acicular zinc oxide. It has a gist where zinc is deposited.
【０００７】この方法を実施するに当たっては、前記水
溶液中の水溶性亜鉛塩濃度は０．０１モル／リットル未
満の低濃度とし、これと併用する尿素の濃度は１モル／
リットル未満で行なうことが好ましい。また、反応液の
ｐＨは中性付近が適当であり、加熱温度は、水溶液中で
の尿素の分解温度以上で、当該水溶液の沸点以下、具体
的には７０〜１００℃、より好ましくは８５〜９５℃の
範囲で行なうことにより、針状の酸化亜鉛を効率よく生
成させることができるので好ましい。また、原料として
用いる水溶性亜鉛塩としては硝酸亜鉛（水和物を含む）
が最適である。[0007] In carrying out this method, the concentration of the water-soluble zinc salt in the aqueous solution is set to a low concentration of less than 0.01 mol / liter, and the concentration of urea used in combination with the concentration is 1 mol / liter.
It is preferred to work with less than 1 liter. The pH of the reaction solution is suitably around neutral, and the heating temperature is not lower than the decomposition temperature of urea in the aqueous solution and not higher than the boiling point of the aqueous solution, specifically 70 to 100 ° C, more preferably 85 to 100 ° C. It is preferable to perform the reaction at a temperature in the range of 95 ° C., since it is possible to efficiently generate acicular zinc oxide. The water-soluble zinc salt used as a raw material is zinc nitrate (including hydrate).
Is optimal.
【０００８】[0008]
【発明の実施の形態】本発明者らは前述した様な従来技
術の下で、針状の酸化亜鉛を簡単な方法で効率よく製造
し得る様な技術の開発を期して種々研究を重ねた結果、
水溶性亜鉛塩の水溶液を尿素の存在下で加熱処理すれ
ば、当該水溶液から酸化亜鉛が針状の結晶として析出
し、これを濾取して乾燥するだけで極めて高純度の針状
酸化亜鉛が簡単に得られることを知り、上記本発明に想
到した。BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have conducted various studies on the basis of the prior art as described above with the aim of developing a technique for efficiently producing acicular zinc oxide by a simple method. result,
When an aqueous solution of a water-soluble zinc salt is subjected to heat treatment in the presence of urea, zinc oxide precipitates as needle-like crystals from the aqueous solution, and this is filtered and dried to obtain extremely high-purity needle-like zinc oxide. Knowing that it can be easily obtained, the present invention has been conceived.
【０００９】上記の様に本発明は、本質的には湿式法に
属するものであるが、従来の湿式法と基本的に異なるの
は、水性系で炭酸亜鉛の如き不溶性亜鉛塩を生成させた
後にこれを焼成して酸化亜鉛に変えるのではなく、水性
系内で直接針状の酸化亜鉛を生成させる点にあり、特に
反応系に尿素を共存させてやれば、これを加熱処理する
だけで、高純度の酸化亜鉛、それも針状の酸化亜鉛が簡
単に得られるという新規知見に基づいている。As described above, the present invention essentially belongs to the wet method, but basically differs from the conventional wet method in that an insoluble zinc salt such as zinc carbonate is formed in an aqueous system. Rather than baking it later to change it to zinc oxide, it is in the point of producing needle-like zinc oxide directly in the aqueous system, especially if urea coexists in the reaction system, it only requires heat treatment. And high purity zinc oxide, which is also based on the novel finding that acicular zinc oxide can be easily obtained.
【００１０】即ち湿式法の基本構成は、たとえば図１の
フロー図に示す如く、硫酸亜鉛などの水溶性亜鉛塩の水
溶液に炭酸または炭酸ナトリウムなどを加えて反応さ
せ、水に不溶性の炭酸亜鉛を沈殿として生成させた後、
これを濾取し洗浄してから乾燥し、これを焼成し熱分解
させることによって酸化亜鉛を得るものである。ところ
がこの方法では、炭酸亜鉛の生成と洗浄・乾燥、焼成の
作業が煩雑で手数を要し、且つ焼成に耐熱設備と多大な
熱エネルギーを要する。That is, as shown in the flow chart of FIG. 1, for example, the basic structure of the wet method is that an aqueous solution of a water-soluble zinc salt such as zinc sulfate is added with carbonic acid or sodium carbonate to cause a reaction. After generating as a precipitate,
This is filtered, washed, dried, fired and thermally decomposed to obtain zinc oxide. However, in this method, the operations of generating, washing, drying, and baking zinc carbonate are complicated and troublesome, and baking requires heat-resistant equipment and a large amount of heat energy.
【００１１】これに対し本発明は、たとえば図２に示す
如く、水溶性亜鉛塩を尿素共存下での加熱反応させた
後、生成する針状酸化物を濾取してから乾燥するだけで
あり、作業が極めて簡単で焼成のための設備や熱エネル
ギーも極めて軽微で済む。On the other hand, according to the present invention, as shown in FIG. 2, for example, after a water-soluble zinc salt is heated and reacted in the presence of urea, the resulting needle-like oxide is filtered off and dried. The operation is extremely simple, and the sintering equipment and heat energy are extremely small.
【００１２】本発明で原料として使用する亜鉛塩として
は、水に可溶性の亜鉛塩であれば全て使用可能であり、
例えば硝酸亜鉛、硫酸亜鉛、塩化亜鉛、酢酸亜鉛などを
使用できる。本発明を実施する際の上記水可溶性亜鉛塩
の濃度は、高純度の酸化亜鉛を水溶液中から針状物とし
て析出させる上で極めて重要であり、０．０１モル／リ
ットル未満、より好ましくは０．００５モル／リットル
以下の低濃度で反応させることが重要となる。As the zinc salt used as a raw material in the present invention, any zinc salt soluble in water can be used.
For example, zinc nitrate, zinc sulfate, zinc chloride, zinc acetate and the like can be used. The concentration of the water-soluble zinc salt at the time of carrying out the present invention is extremely important for precipitating high-purity zinc oxide as an acicular substance from an aqueous solution, and is less than 0.01 mol / liter, more preferably 0 mol / liter. It is important to react at a low concentration of 0.005 mol / liter or less.
【００１３】ちなみに、水可溶性亜鉛塩の濃度が０．０
１モル／リットル以上になると、尿素共存下での加熱反
応工程で粒状の塩基性炭酸亜鉛が生成し、針状酸化亜鉛
の生成率が極端に低下してくる。しかも該塩基性炭酸亜
鉛は、その後の焼成によって酸化亜鉛に変えなければな
らず、針状物としての生成率が極端に減少することもあ
って、本発明の目的を果たすことができない。Incidentally, when the concentration of the water-soluble zinc salt is 0.0
If it is 1 mol / liter or more, granular basic zinc carbonate is produced in the heating reaction step in the presence of urea, and the production rate of acicular zinc oxide is extremely reduced. In addition, the basic zinc carbonate must be changed to zinc oxide by the subsequent calcination, and the production rate of needles may be extremely reduced, so that the object of the present invention cannot be achieved.
【００１４】また本発明では、上記水可溶性亜鉛塩を尿
素の共存下で加熱反応させることが必須であり、共存さ
せる尿素の濃度も針状酸化亜鉛の生成率を高める上で非
常に重要であり、好ましくは１モル／リットル未満、よ
り好ましくは０．５モル／リットル以下にすべきであ
る。尿素濃度が高くなり過ぎると、反応生成物が粒状の
塩基性炭酸亜鉛リッチとなり、やはり本発明の目的にそ
ぐわなくなる。In the present invention, it is essential that the water-soluble zinc salt is heated and reacted in the presence of urea, and the concentration of the urea to be coexisted is also very important for increasing the production rate of acicular zinc oxide. , Preferably less than 1 mol / l, more preferably not more than 0.5 mol / l. If the urea concentration is too high, the reaction product becomes granular basic zinc carbonate rich, which again is not suitable for the purpose of the present invention.
【００１５】ちなみに、本発明者らが水可溶性亜鉛塩お
よび尿素の好適濃度範囲と反応生成物の関係について検
討したところ、水可溶性亜鉛塩と尿素のいずれについて
も、高濃度側では塩基性炭酸亜鉛（ＢＺＣ）が生成する
のに対し、両者を低濃度側で加熱反応させると、高純度
の酸化亜鉛が水性反応液中から針状物として沈殿してく
ることが分かった。従って、これを濾取して乾燥するだ
けで、高純度の針状酸化亜鉛を容易に得ることができる
のである。By the way, the present inventors have studied the relationship between the preferred concentration range of water-soluble zinc salt and urea and the reaction product. While (BZC) was produced, it was found that when both were heated and reacted on the low concentration side, high-purity zinc oxide was precipitated as needles from the aqueous reaction solution. Therefore, high-purity needle-like zinc oxide can be easily obtained only by filtering and drying.
【００１６】反応温度も、針状酸化亜鉛の生成反応を促
進する上で重要な要素であり、好ましくは７０℃以上、
より好ましくは８５℃以上に加熱することが必須とな
る。ちなみに、たとえ適量の尿素を共存させたとして
も、加熱温度が７０℃未満の低温では酸化亜鉛の生成反
応自体が殆ど進まないことから、該反応温度は、水溶液
中での尿素の熱分解反応と密接な関係を有しており、且
つ、該分解反応生成物が針状酸化亜鉛の生成反応を促し
ているものと考えられる。The reaction temperature is also an important factor in accelerating the acicular zinc oxide formation reaction.
More preferably, heating to 85 ° C. or higher is essential. By the way, even if an appropriate amount of urea coexists, the reaction temperature itself is almost equal to the thermal decomposition reaction of urea in an aqueous solution, since the formation reaction itself of zinc oxide hardly proceeds at a low heating temperature of less than 70 ° C. It is considered that they have a close relationship and that the decomposition reaction product promotes a reaction for producing acicular zinc oxide.
【００１７】即ち、尿素を水溶液状態で加熱すると一部
がアンモニアと炭酸ガスに分解することが確認されてお
り、生成初期のアンモニアや炭酸ガスが水に溶解してア
ンモニア水と炭酸となり、これらが水可溶性亜鉛塩と何
らかの反応を起こし、水溶液中での針状酸化亜鉛の生成
を促しているものと予測される。That is, it has been confirmed that when urea is heated in an aqueous solution state, a part of the urea is decomposed into ammonia and carbon dioxide, and the ammonia and carbon dioxide in the initial stage of dissolution dissolve in water to form ammonia water and carbon dioxide. It is expected that some reaction with the water-soluble zinc salt occurs to promote the formation of acicular zinc oxide in the aqueous solution.
【００１８】ちなみに、本発明における尿素共存下での
前記針状酸化亜鉛の生成反応は７０℃程度以上の温度で
急速に進行し始めることが確認されており、この温度は
上記尿素の分解が起こり始める温度とほぼ一致している
からである。Incidentally, it has been confirmed that the above-mentioned acicular zinc oxide formation reaction in the present invention in the presence of urea rapidly starts to proceed at a temperature of about 70 ° C. or more. This is because the temperature almost coincides with the starting temperature.
【００１９】よって本発明を効率よく実施するには、反
応温度を７０℃以上、より好ましくは８５℃以上とする
のが良く、一方反応温度の上限は特に存在しないが、常
圧で行なう場合は、反応液が沸騰することのない１００
℃未満、より好ましくは９５℃程度までの温度に止める
ことが望ましい。反応液が沸騰すると、反応設備に還流
冷却装置などの付設が必要となり、設備が複雑になるば
かりでなく、尿素の分解によって生成するアンモニアや
炭酸ガスが速やかに系外へ放出され、針状酸化亜鉛の生
成反応を却って遅らせる原因になりかねないからであ
る。但し、必要によっては反応装置を耐圧構造とし、加
圧下に１００℃以上の温度で反応を進めることも勿論可
能である。Therefore, in order to carry out the present invention efficiently, the reaction temperature is preferably 70 ° C. or higher, more preferably 85 ° C. or higher. On the other hand, there is no particular upper limit of the reaction temperature. 100 without boiling the reaction solution
It is desirable to keep the temperature at less than 0 ° C, more preferably up to about 95 ° C. When the reaction liquid boils, it is necessary to add a reflux cooling device or the like to the reaction equipment, which not only complicates the equipment, but also releases ammonia and carbon dioxide gas generated by the decomposition of urea quickly to the outside of the system, resulting in acicular oxidation. This may cause a delay in the reaction of generating zinc. However, if necessary, the reaction apparatus may have a pressure-resistant structure, and the reaction may of course proceed at a temperature of 100 ° C. or more under pressure.
【００２０】反応液のｐＨも特に制限されないが、本発
明者らが確認しているところでは、反応系のｐＨがアル
カリ性や酸性側に偏ると塩基性炭酸亜鉛の生成反応が進
行し易くなり、針状酸化亜鉛の生成率や純度が低下傾向
を示す様になるので、必要によりアンモニア水などの弱
塩基や酢酸などの弱酸を用いて反応液を中性付近、即ち
ｐＨ７の前後に調整して前記加熱反応を行なうことが望
ましい。Although the pH of the reaction solution is not particularly limited, it has been confirmed by the present inventors that if the pH of the reaction system is biased toward an alkaline or acidic side, the reaction of forming basic zinc carbonate is likely to proceed, Since the production rate and purity of the acicular zinc oxide tend to decrease, the reaction solution is adjusted to near neutrality, that is, around pH 7, using a weak base such as ammonia water or a weak acid such as acetic acid as necessary. It is desirable to carry out the heating reaction.
【００２１】なお本発明を実施するに当たっては、反応
時間も重要な制御要件であり、反応温度や濃度に応じて
最適の反応時間を選定することが望ましい。即ち本発明
者らが実験により確認したところでは、加熱反応の初期
段階では塩基性炭酸亜鉛主体の粒状物が生成するが、攪
拌状態で更に反応を進めると該粒状の塩基性炭酸亜鉛が
針状の酸化亜鉛に変化し、その後更に反応時間が経過す
ると、該針状の酸化亜鉛が再び粒状の塩基性炭酸亜鉛に
変化していく。In practicing the present invention, the reaction time is also an important control requirement, and it is desirable to select an optimum reaction time according to the reaction temperature and concentration. That is, the present inventors have confirmed by experiments that, at the initial stage of the heating reaction, particulates mainly composed of basic zinc carbonate are formed, but when the reaction is further advanced in a stirring state, the particulate basic zinc carbonate becomes acicular. When the reaction time further elapses, the acicular zinc oxide changes again to granular basic zinc carbonate.
【００２２】例えば、０．００１モル／リットルの硝酸
亜鉛水溶液に０．０１モル／リットルの尿素を溶解し、
アンモニア水でｐＨ７．０に調整した水溶液を、攪拌下
に９５℃に加熱して反応を行なう際に、反応時間の経過
に伴う生成物の生成状況を観察したところ、次の様な事
実が確認された。即ち、上記反応の開始直後（５分後）
に生成する析出物は粒状の塩基性炭酸亜鉛が主体である
のに対し、同温度で２時間反応を進めた後の生成物は、
殆どが針状の酸化亜鉛（図３参照）となり、その後更に
加熱反応を続けると、該針状酸化亜鉛が徐々に粒状の塩
基性炭酸亜鉛に変化し、６時間経過後には殆どが粒状の
塩基性炭酸亜鉛に変化することが確認された。For example, 0.01 mol / l of urea is dissolved in 0.001 mol / l of zinc nitrate aqueous solution,
When an aqueous solution adjusted to pH 7.0 with ammonia water was heated to 95 ° C. with stirring to perform the reaction, the following facts were confirmed by observing the formation of products with the lapse of reaction time. Was done. That is, immediately after the start of the above reaction (after 5 minutes)
While the precipitate generated in the above is mainly composed of granular basic zinc carbonate, the product after the reaction is advanced for 2 hours at the same temperature is
Most of the zinc oxide becomes acicular zinc oxide (see FIG. 3). When the heating reaction is further continued, the acicular zinc oxide gradually changes to granular basic zinc carbonate. It was confirmed to change to zinc carbonate.
【００２３】この様に本発明を実施するに当たり、針状
酸化亜鉛の生成率、延いてはその収率を高めるには、反
応条件に応じて反応時間を適切に制御すべきであり、反
応時間が短すぎても又長すぎて塩基性炭酸亜鉛の生成量
が増大し、結果的に針状酸化亜鉛の生成量は減少してく
る。こうした現象が生じる理由は未だ明確にされていな
いが、反応系内に共存する尿素の熱分解とそれにより生
成する初期のアンモニアや炭酸ガスと水可溶性亜鉛塩と
の間で何らかの反応が起こり、反応時間の経過につれて
塩基性炭酸亜鉛又は針状酸化亜鉛の生成反応に何らかの
影響を及ぼしているためと考えている。As described above, in carrying out the present invention, the reaction time should be appropriately controlled in accordance with the reaction conditions in order to increase the production rate of the acicular zinc oxide, and furthermore, the yield thereof. Is too short or too long, the production of basic zinc carbonate increases, and consequently the production of acicular zinc oxide decreases. Although the reason for this phenomenon has not been clarified yet, some reaction occurs between the thermal decomposition of urea coexisting in the reaction system and the initial ammonia or carbon dioxide gas produced by the decomposition, and the water-soluble zinc salt. It is considered that the influence is exerted on the formation reaction of basic zinc carbonate or acicular zinc oxide over time.
【００２４】何れにしても尿素共存下の加熱反応工程で
は、上記の様に初期の塩基性炭酸亜鉛生成反応と末期の
塩基性炭酸亜鉛生成反応と、その途中段階で針状酸化亜
鉛量が最も増大する時期が存在し、この時期は反応温度
や反応系の濃度、ｐＨなどによっても変わってくるの
で、それら条件に応じて針状酸化亜鉛の生成率が最大と
なる反応時間を設定することで、実質的に針状酸化亜鉛
のみを生成させることができ、これを濾取してから洗浄
し乾燥することで、高純度の針状酸化亜鉛を得ることが
できる。In any case, in the heating reaction step in the presence of urea, the initial basic zinc carbonate generation reaction and the final basic zinc carbonate generation reaction as described above, There is a period of increase, and this period varies depending on the reaction temperature, the concentration of the reaction system, the pH, etc., so by setting the reaction time at which the production rate of acicular zinc oxide is maximized according to those conditions. Thus, only acicular zinc oxide can be substantially produced, and by filtering, washing and drying, high-purity acicular zinc oxide can be obtained.
【００２５】[0025]
【実施例】以下、実施例を挙げて本発明をより具体的に
説明するが、本発明はもとより下記実施例によって制限
を受けるものではなく、前・後記の趣旨に適合し得る範
囲で適当に変更を加えて実施することも可能であり、そ
れらはいずれも本発明の技術的範囲に包含される。EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, and the present invention is not limited thereto. Modifications can be made and all of them are included in the technical scope of the present invention.
【００２６】実施例１ ３リットルのビーカー中に硝酸亜鉛Zn(NO3)2・６H2Oを
０．６ｇ、尿素を１２ｇ、水２リットルを入れて溶解さ
せる。これにアンモニアを加えてｐＨ7に調整し、時計
皿で蓋をした後、マグネチックスターラーで攪拌しなが
らヒーターで９５℃まで昇温し、同温度で３時間反応さ
せると、針状の結晶が析出する。これを濾取して自然乾
燥すると、針状の酸化亜鉛０．２ｇが得られる。Example 1 In a 3 liter beaker, 0.6 g of zinc nitrate Zn (NO 3 ) 2 .6H 2 O, 12 g of urea and 2 liter of water are put and dissolved. After adjusting the pH to 7 by adding ammonia, covering with a watch glass, heating to 95 ° C with a heater while stirring with a magnetic stirrer, and reacting at the same temperature for 3 hours, needle-like crystals precipitate. I do. This is filtered and air-dried to obtain 0.2 g of acicular zinc oxide.
【００２７】実施例２ ３リットルのビーカー中に硝酸亜鉛Zn(NO3)2・６H2Oを
０．６ｇ、尿素を１．２ｇ、水２リットルを入れて溶解
させる。これにアンモニアを加えてｐＨ7に調整し、時
計皿で蓋をした後、マグネチックスターラーで攪拌しな
がらヒーターで９５℃まで昇温し、同温度で３時間反応
させると、針状の結晶が析出する。これを濾取して自然
乾燥すると、針状の酸化亜鉛０．２ｇが得られる。Example 2 In a 3 liter beaker, 0.6 g of zinc nitrate Zn (NO 3 ) 2 .6H 2 O, 1.2 g of urea, and 2 liter of water are put and dissolved. After adjusting the pH to 7 by adding ammonia, covering with a watch glass, heating to 95 ° C with a heater while stirring with a magnetic stirrer, and reacting at the same temperature for 3 hours, needle-like crystals precipitate. I do. This is collected by filtration and air-dried to obtain 0.2 g of acicular zinc oxide.
【００２８】実施例３ ５０リットルの反応槽に硝酸亜鉛Zn(NO3)2・６H2Oを１
２ｇ、尿素を２４０ｇ、水４０リットルを入れて溶解さ
せる。これにアンモニアを加えてｐＨ7に調整し、マグ
ネチックスターラーで攪拌しながらヒーターで９５℃ま
で昇温し、同温度で３時間反応させると、針状の結晶が
析出する。これを濾取し、乾燥機を用いて９０℃で乾燥
すると、針状の酸化亜鉛３ｇが得られる。得られた針状
結晶のＸ線回折チャートを図４に示す。[0028] Example 3 A reaction vessel a 50 liter zinc nitrate Zn (NO 3) 2 · 6H 2 O 1
2 g, 240 g of urea and 40 liters of water are added and dissolved. Ammonia is added to the mixture to adjust the pH to 7, and the temperature is raised to 95 ° C. with a heater while stirring with a magnetic stirrer, and the mixture is reacted at the same temperature for 3 hours to precipitate needle-like crystals. This is collected by filtration and dried at 90 ° C. using a dryer to obtain 3 g of acicular zinc oxide. FIG. 4 shows an X-ray diffraction chart of the obtained needle-like crystal.
【００２９】比較例１ ３リットルのビーカー中に硝酸亜鉛Zn(NO3)2・６H2Oを
０．６ｇ、尿素を１２０ｇ、水２リットルを入れて溶解
させる。これにアンモニアを加えてｐＨ7に調整し、時
計皿で蓋をした後、マグネチックスターラーで攪拌しな
がらヒーターで９５℃まで昇温し、同温度で３時間反応
させると、白色の不溶物が析出する。これを濾取して自
然乾燥すると、塩基性炭酸亜鉛の凝集体０．３ｇが得ら
れる。Comparative Example 1 In a 3 liter beaker, 0.6 g of zinc nitrate Zn (NO 3 ) 2 .6H 2 O, 120 g of urea and 2 liters of water were put and dissolved. After adjusting the pH to 7 by adding ammonia, covering with a watch glass, heating the mixture to 95 ° C with a heater while stirring with a magnetic stirrer, and reacting at the same temperature for 3 hours, a white insoluble substance precipitates. I do. This is collected by filtration and air-dried to obtain 0.3 g of an aggregate of basic zinc carbonate.
【００３０】比較例２ ３リットルのビーカー中に硝酸亜鉛Zn(NO3)2・６H2Oを
６ｇ、尿素を１２０ｇ、水２リットルを入れて溶解させ
る。これにアンモニアを加えてｐＨ7に調整し、時計皿
で蓋をした後、マグネチックスターラーで攪拌しながら
ヒーターで９５℃まで昇温し、同温度で３時間反応させ
ると、白色の不溶物が析出する。これを濾取して自然乾
燥すると、塩基性炭酸亜鉛の凝集体３ｇが得られる。Comparative Example 2 In a 3 liter beaker, 6 g of zinc nitrate Zn (NO 3 ) 2 .6H 2 O, 120 g of urea and 2 liter of water were put and dissolved. After adjusting the pH to 7 by adding ammonia, covering with a watch glass, heating the mixture to 95 ° C with a heater while stirring with a magnetic stirrer, and reacting at the same temperature for 3 hours, a white insoluble substance precipitates. I do. This is collected by filtration and dried naturally to obtain 3 g of an aggregate of basic zinc carbonate.
【００３１】比較例３ ３リットルのビーカー中に硝酸亜鉛Zn(NO3)2・６H2Oを
６ｇ、尿素を１２ｇ、水２リットルを入れて溶解させ
る。これにアンモニアを加えてｐＨ7に調整し、時計皿
で蓋をした後、マグネチックスターラーで攪拌しながら
ヒーターで９５℃まで昇温し、同温度で３時間反応させ
ると、白色の不溶物が析出する。これを濾取して自然乾
燥すると、塩基性炭酸亜鉛の凝集体３ｇが得られる。Comparative Example 3 In a 3 liter beaker, 6 g of zinc nitrate Zn (NO 3 ) 2 .6H 2 O, 12 g of urea, and 2 liter of water were put and dissolved. After adjusting the pH to 7 by adding ammonia, covering with a watch glass, heating the mixture to 95 ° C with a heater while stirring with a magnetic stirrer, and reacting at the same temperature for 3 hours, a white insoluble substance precipitates. I do. This is collected by filtration and dried naturally to obtain 3 g of an aggregate of basic zinc carbonate.
【００３２】比較例４ ３リットルのビーカー中に硝酸亜鉛Zn(NO3)2・６H2Oを
６ｇ、尿素を１．２ｇ、水２リットルを入れて溶解させ
る。これにアンモニアを加えてｐＨ7に調整し、時計皿
で蓋をした後、マグネチックスターラーで攪拌しながら
ヒーターで９５℃まで昇温し、同温度で３時間反応させ
ると、白色の不溶物が析出する。これを濾取して自然乾
燥すると、塩基性炭酸亜鉛の凝集体３ｇが得られる。Comparative Example 4 In a 3 liter beaker, 6 g of zinc nitrate Zn (NO 3 ) 2 .6H 2 O, 1.2 g of urea and 2 liter of water were put and dissolved. After adjusting the pH to 7 by adding ammonia, covering with a watch glass, heating the mixture to 95 ° C with a heater while stirring with a magnetic stirrer, and reacting at the same temperature for 3 hours, a white insoluble substance precipitates. I do. This is collected by filtration and dried naturally to obtain 3 g of an aggregate of basic zinc carbonate.
【００３３】比較例５ ３リットルのビーカー中に硝酸亜鉛Zn(NO3)2・６H2Oを
６０ｇ、尿素を１２ｇ、水２リットルを入れて溶解させ
る。これにアンモニアを加えてｐＨ7に調整し、時計皿
で蓋をした後、マグネチックスターラーで攪拌しながら
ヒーターで９５℃まで昇温し、同温度で３時間反応させ
ると、白色の不溶物が析出する。これを濾取して自然乾
燥すると、塩基性炭酸亜鉛の凝集体３０ｇが得られる。Comparative Example 5 In a 3 liter beaker, 60 g of zinc nitrate Zn (NO 3 ) 2 .6H 2 O, 12 g of urea, and 2 liters of water were put and dissolved. After adjusting the pH to 7 by adding ammonia, covering with a watch glass, heating the mixture to 95 ° C with a heater while stirring with a magnetic stirrer, and reacting at the same temperature for 3 hours, a white insoluble substance precipitates. I do. This is collected by filtration and dried naturally to obtain 30 g of an aggregate of basic zinc carbonate.
【００３４】比較例６（尿素不使用の例） ３リットルのビーカー中に硝酸亜鉛Zn(NO3)2・６H2Oを
６０ｇと水２リットルを入れて溶解させる。これにアン
モニアを加えてｐＨ7に調整し、時計皿で蓋をした後、
マグネチックスターラーで攪拌しながらヒーターで９５
℃まで昇温し、同温度で３時間反応させたが、不溶物の
析出はみられなかった。[0034] dissolving Comparative Example 6 zinc nitrate Zn (NO 3) in a beaker of (urea Example unused) 3 liters 2 · 6H 2 O Put 60g and 2 liters of water. Adjust the pH to 7 by adding ammonia to this, cover with a watch glass,
95 with heater while stirring with magnetic stirrer
The temperature was raised to 0 ° C., and the reaction was carried out at the same temperature for 3 hours, but no insoluble matter was precipitated.
【００３５】比較例７ ３リットルのビーカー中に硫酸亜鉛ZnSO4を１０ｇと水
２リットルを入れて溶解させる。これに炭酸ナトリウム
７ｇを加えると、白色の沈殿が生成する。これを濾取
し、マッフル炉を用いて６００℃で焼成すると、ほぼ球
形の酸化亜鉛粉末が得られる。該酸化亜鉛粉末のＸ線回
折チャートを、前記実施例３で得た針状酸化亜鉛と対比
して図４に示す。Comparative Example 7 In a 3 liter beaker, 10 g of zinc sulfate ZnSO 4 and 2 liters of water were put and dissolved. When 7 g of sodium carbonate is added to this, a white precipitate forms. This is filtered and baked at 600 ° C. using a muffle furnace to obtain a substantially spherical zinc oxide powder. An X-ray diffraction chart of the zinc oxide powder is shown in FIG. 4 in comparison with the acicular zinc oxide obtained in Example 3.
【００３６】[0036]
【発明の効果】本発明は以上の様に構成されており、水
溶性亜鉛塩の水溶液を尿素の共存下で加熱反応させるだ
けで、高純度の針状酸化亜鉛を生成させることができ、
これを濾取して乾燥するだけで、特異な針状結晶構造を
有する酸化亜鉛を高純度品として簡単に製造し得ること
になった。The present invention is constituted as described above, and a high-purity acicular zinc oxide can be produced only by heating and reacting an aqueous solution of a water-soluble zinc salt in the presence of urea.
By simply filtering and drying, zinc oxide having a unique needle-like crystal structure can be easily produced as a high-purity product.
【図１】湿式法を採用した従来の酸化亜鉛の製法を例示
するフロー図である。FIG. 1 is a flowchart illustrating a conventional method for producing zinc oxide employing a wet method.
【図２】本発明に係る針状酸化亜鉛の製法を例示するフ
ロー図である。FIG. 2 is a flowchart illustrating a method for producing acicular zinc oxide according to the present invention.
【図３】本発明法により生成した針状酸化亜鉛の顕微鏡
写真である。FIG. 3 is a photomicrograph of acicular zinc oxide produced by the method of the present invention.
【図４】本発明によって得た針状酸化亜鉛と、従来法に
よって得た粒状酸化亜鉛のＸ線回折チャートを対比して
示すものである。FIG. 4 is a comparison between X-ray diffraction charts of acicular zinc oxide obtained by the present invention and granular zinc oxide obtained by a conventional method.
フロントページの続き (72)発明者 斉藤 紀子 茨城県つくば市並木１丁目１番 文部科学 省無機材質研究所内 (72)発明者 菱田 俊一 茨城県つくば市並木１丁目１番 文部科学 省無機材質研究所内 (72)発明者 永井 貴 福岡県飯塚市横田669 ハクスイテック株 式会社九州研究開発センター内 (72)発明者 河野 絹代 大阪府堺市築港新町３丁目６番３号 ハク スイテック株式会社大阪研究開発センター 内 (72)発明者 山本 泰生 福岡県飯塚市横田669 ハクスイテック株 式会社九州研究開発センター内 Ｆターム(参考） 4G047 AA02 AB02 AC02 AD04 Continued on the front page. (72) Inventor Noriko Saito 1-1, Namiki, Tsukuba, Ibaraki Pref., Japan Inorganic Materials Research Laboratories, Ministry of Education, Culture, Sports, Science and Technology (72) Inventor Shunichi Hishida 1-1, Namiki 1, Tsunami, Tsukuba, Ibaraki, Japan (72) Inventor Takashi Nagai 669 Yokota, Iizuka-shi, Fukuoka Haksuitec Co., Ltd. Kyushu R & D Center (72) Inventor Kinuyo 3-6-3 Chikushinmachi, Sakai-shi, Osaka Haksuitec Osaka Research and Development Center (72) Inventor Yasuo Yamamoto 669 Yokota, Iizuka-shi, Fukuoka F-term in the Kyushu R & D Center of Hakusuitec Co., Ltd. 4G047 AA02 AB02 AC02 AD04
Claims (3)
し、該水溶液から針状の酸化亜鉛を析出させることを特
徴とする針状酸化亜鉛の製法。1. A method for producing acicular zinc oxide, comprising heating an aqueous solution containing a water-soluble zinc salt and urea to precipitate acicular zinc oxide from the aqueous solution.
０１モル／リットル未満、尿素濃度を１モル／リットル
未満とする請求項１に記載の製法。2. The concentration of a water-soluble zinc salt in the aqueous solution is set at 0.
2. The process according to claim 1, wherein the urea concentration is less than 1 mol / l and the urea concentration is less than 1 mol / l.
度以上で、当該水溶液の沸点以下とする請求項１または
２に記載の製法。3. The method according to claim 1, wherein the heating temperature is not lower than the decomposition temperature of urea in the aqueous solution and not higher than the boiling point of the aqueous solution.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007022851A (en) * | 2005-07-15 | 2007-02-01 | National Institute Of Advanced Industrial & Technology | Porous zinc oxide film, method for manufacturing the same, dye-sensitized solar cell, photocatalyst, chemical sensor or phosphor each provided with porous zinc oxide film, precursor for forming porous zinc oxide film and method for manufacturing the same |
| CN1323948C (en) * | 2005-02-02 | 2007-07-04 | 苏州大学 | Preparation method of nanometer zinc oxide |
| JP2008094696A (en) * | 2006-10-16 | 2008-04-24 | Sakai Chem Ind Co Ltd | Fine needle zinc oxide |
| JP2008094695A (en) * | 2006-10-16 | 2008-04-24 | Sakai Chem Ind Co Ltd | Method for manufacturing needle zinc oxide |
| KR100854771B1 (en) | 2006-12-28 | 2008-08-27 | 한국원자력연구원 | Nano rod-shaped zinc oxide powder and method of manufacturing the same |
| JP2010030819A (en) * | 2008-07-28 | 2010-02-12 | Sakai Chem Ind Co Ltd | Method for producing nitrogen-containing zinc oxide powder |
| JP2011084465A (en) * | 2010-11-30 | 2011-04-28 | Fujifilm Corp | Zinc oxide structure, zinc oxide particle and method for producing the same |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6029645B2 (en) * | 1981-06-12 | 1985-07-11 | 学校法人東海大学 | Method for producing acicular zinc oxide particles |
| JPH01252600A (en) * | 1987-12-29 | 1989-10-09 | Matsushita Electric Ind Co Ltd | Production of zinc oxide whisker |
| JPH04164816A (en) * | 1990-10-30 | 1992-06-10 | Mitsubishi Materials Corp | Production of acicular zinc oxide powder by submerged synthetic method |
-
2001
- 2001-03-16 JP JP2001077096A patent/JP4737577B2/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6029645B2 (en) * | 1981-06-12 | 1985-07-11 | 学校法人東海大学 | Method for producing acicular zinc oxide particles |
| JPH01252600A (en) * | 1987-12-29 | 1989-10-09 | Matsushita Electric Ind Co Ltd | Production of zinc oxide whisker |
| JPH04164816A (en) * | 1990-10-30 | 1992-06-10 | Mitsubishi Materials Corp | Production of acicular zinc oxide powder by submerged synthetic method |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1323948C (en) * | 2005-02-02 | 2007-07-04 | 苏州大学 | Preparation method of nanometer zinc oxide |
| JP2007022851A (en) * | 2005-07-15 | 2007-02-01 | National Institute Of Advanced Industrial & Technology | Porous zinc oxide film, method for manufacturing the same, dye-sensitized solar cell, photocatalyst, chemical sensor or phosphor each provided with porous zinc oxide film, precursor for forming porous zinc oxide film and method for manufacturing the same |
| JP4714844B2 (en) * | 2005-07-15 | 2011-06-29 | 独立行政法人産業技術総合研究所 | Method for producing precursor for forming porous zinc oxide film, method for producing porous zinc oxide film |
| JP2008094696A (en) * | 2006-10-16 | 2008-04-24 | Sakai Chem Ind Co Ltd | Fine needle zinc oxide |
| JP2008094695A (en) * | 2006-10-16 | 2008-04-24 | Sakai Chem Ind Co Ltd | Method for manufacturing needle zinc oxide |
| KR100854771B1 (en) | 2006-12-28 | 2008-08-27 | 한국원자력연구원 | Nano rod-shaped zinc oxide powder and method of manufacturing the same |
| US8038979B2 (en) | 2006-12-28 | 2011-10-18 | Korea Atomic Energy Research Institute | Metal oxide nano powder and manufacturing method of the same |
| JP2010030819A (en) * | 2008-07-28 | 2010-02-12 | Sakai Chem Ind Co Ltd | Method for producing nitrogen-containing zinc oxide powder |
| JP2011084465A (en) * | 2010-11-30 | 2011-04-28 | Fujifilm Corp | Zinc oxide structure, zinc oxide particle and method for producing the same |
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