JP2004043353A - Method for continuously producing organic titanium peroxo compound and device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for continuously producing an organic titanium peroxo compound, by which the organic titanium peroxo compound having a high quality can stably be produced, and to provide a device for producing the same. <P>SOLUTION: This method for continuously producing the organic titanium peroxo compound is characterized by comprising the first reaction process for continuously feeding metal titanium powder, hydrogen peroxide and ammonia water into a dissolution reaction tank maintained at a prescribed temperature to dissolve the metal titanium, thus producing the solution of the peroxotitanic acid, and the second reaction process for continuously feeding one or more organic complexing agents selected from the group consisting of carboxylic acids, acetylacetone and amines to the peroxotitanic acid solution discharged from the first reaction process, thus reacting with the peroxotatanic acid to produce the organic peroxo compound solution. <P>COPYRIGHT: (C)2004,JPO

Description

【００６０】
そして、実施例１の試料とビーカー・回分式で製造した試料についてＸ線回折法、ラマン分光法、固体^１３Ｃ−ＮＭＲ分光法による測定を行った結果、目的とする化合物であるチタンペルオキソクエン酸アンモニウム（（ＮＨ_４）_２［Ｔｉ（Ｃ_６Ｈ_４Ｏ_７）Ｏ_２］・２Ｈ_２Ｏ）であることが確認された。
【００６１】
図３は実施例１で得られた試料のＸ線回折パターンを示す。図３には実施例１の結果と共にビーカー・回分式の結果を示す。実施例１の試料はビーカー・回分式で製造した試料よりもピークがシャープであり、細かいピークが一つ一つ観察される。このため、実施例の試料は結晶性が非常に高く、純度が高い。
【００６２】
上記の各測定結果によれば、実施例１の試料とビーカー・回分式の試料の測定結果はほぼ一致しているが、結晶性については実施例の試料の方が優れている。このことから、実施例の試料は、実用に供し得る品質であるビーカー・回分式の試料と同程度以上の品質であることが確認された。
【００６３】
［比較例１］
大型ビーカー（２リットル）を回分式反応槽として使用し、回分式によるチタンペルオキソクエン酸アンモニウムの製造を行った。製造条件は、回分式によることを除き、原料の供給比及び反応温度を実施例１とほぼ同じにした。この際、得られる試料品質の再現性を調べるために、その製造を２回行った。
【００６４】
金属チタン粉末１０ｇ、３０％過酸化水素水８００ｍｌ、３０％アンモニア水２００ｍｌを２リットルのビーカーに入れて混合し、ウォーターバスで冷却しながら、金属チタンを溶解させ、黄色いチタンペルオキソ溶液を得た。次に、得られた溶液にチタンに対して１倍モル以上のクエン酸を加えた。加えたクエン酸が完全に溶けきった後、ビーカーをホットプレートにのせて８０℃で加熱乾燥し、黄色い結晶を得た（ロット１の製造）。又、上記と同じ操作を行って２回目の製造を行った（ロット２の製造）。
【００６５】
図４は比較例１で得られた固体^１３Ｃ−ＮＭＲによる測定結果を示す。図４の下段には、比較のために、実施例１の試料の測定結果も併せて示した。
【００６６】
図４によれば、比較例１で得られた２つの試料（ロット１、ロット２）の測定結果をみると、ｂ，ｂ´とマークされたピークの強度比が異なっており、又、ｃ，ｃ´，ｄ´とマークされたピークの全体形状が異なっている。このように、製造方法が回分式の場合、反応槽が５００ｍｌから２リットルになった程度の装置規模の違いがあっただけでも、同一品質の製品が再現性よく得られないことを示している。又、本来、ピークが１本であるべきところにｂとｂ´の２本のピークが観測されており、比較例１の試料が単一の化合物からなるものでないことを示している。又、ａ，ａ´やｃ，ｃ´は本来分離して観測されるべきピークであるが、ブロードなピークになっていることから、比較例１の試料には様々な組成の化合物が含まれていたり、あるいはチタンの加水分解生成物が含まれていることを示している。
【００６７】
これに対し、実施例１の試料の測定結果はピークが非常にシャープであり、単一の化合物が得られていることを示している。
【００６８】
上記の結果によれば、回分式製造法による場合、反応槽の規模を大きくすると、槽内の反応条件を一定に制御することが困難なるので、実用に供することが出来る製品を得ることが難しいものと判断される。このため、チタンペルオキソクエン酸アンモニウムを工業的規模で製造する場合、回分式製造法を採用することは困難である。
【００６９】
［実施例２］
実施例１と同じ装置を用い、チタン原料を、試薬チタン粉末に替えて工業原料用金属チタン（東邦チタニウム（株）製、Ｔｉ９９％）を供給したこと以外は実施例１と同一条件で、チタンペルオキソクエン酸アンモニウムを製造する試験を行った。
【００７０】
この試験において、最終反応槽から排出された溶液は実施例１で得られた溶液と外観上の違いもなく、特に異常反応は認められなかった。又、その溶液を真空濃縮して得た結晶の化合物組成、結晶構造と結晶性などを評価する測定においても、それらの結果は実施例１の結果と比べて誤差範囲内で一致していた。この結果、工業原料用金属チタンを原料として製造したチタンペルオキソクエン酸アンモニウムは、強誘電体不揮発性メモリ、光触媒などの原料として十分使用可能なものであるものと判断された。
【００７１】
【発明の効果】
本発明によれば、強誘電体不揮発性メモリ、光触媒などの原料として使用される有機チタンペルオキソ化合物を安価に量産することができると共に、高品質の製品を安定的に製造することができる。
【図面の簡単な説明】
【図１】本発明の製造装置の構成に係る実施の形態の一例を示すフローダイアグラムである。
【図２】金属チタンと過酸化水素を反応させる際の反応温度の影響を示す図である。
【図３】実施例で得られた試料のＸ線回折パターンを示す図である。
【図４】比較例１で得られた固体^１３Ｃ−ＮＭＲによる測定結果を示す図である。
【符号の説明】
１０　金属チタン粉末の供給ホッパー
１１　金属チタン粉末の定量計量供給器
１２　過酸化水素水の供給槽
１３　過酸化水素水定量供給ポンプ
１４　アンモニア水の供給槽
１５　アンモニア水定量供給ポンプ
２０　第１溶解反応槽
２１　第２溶解反応槽
２２，２３　攪拌機
２４，２５　水冷ジャケット
２６，２７　温度計
２８，２９　流量調節器
３０　制御装置
４０　第１有機錯体化反応槽
４１　第２有機錯体化反応槽
４２，４３　攪拌機
４６　クエン酸の供給槽
４７　クエン酸定量供給ポンプ
５２　晶析装置
６０　アンモニア吸収塔[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for producing an organic titanium peroxo compound used as a raw material of an oxide or a composite oxide used as a material such as a dielectric, a photocatalyst, and a phosphor.
[0002]
[Prior art]
In recent years, as an electronic material whose importance has increased, for example, there is a nonvolatile memory using a dielectric thin film of a composite oxide. This composite oxide thin film is produced by a solution coating method. In this method, a solution containing a metal component constituting a composite oxide is coated on a substrate, subjected to an appropriate chemical treatment to form a gel-like film, and heat-treated to form a thin film.
[0003]
When a thin film of a composite oxide of titanium is produced by the above solution coating method, a solution of a titanium compound must be used as a matter of course. However, a titanium compound capable of obtaining a stable aqueous solution is not known. That is, most titanium compounds are hardly soluble in water, and even if they are water-soluble, for example, titanium tetrachloride, they exist as stable solutions only under strong acidity. In a neutral aqueous solution, it is hydrolyzed to produce a poorly water-soluble compound. Titanium alkoxide, which is known as an organic titanium compound, is stable in a non-aqueous solvent, but is hydrolyzed by the presence of a small amount of water and is an extremely unstable compound.
[0004]
For this reason, in the production of a thin film by a solution coating method, titanium alkoxide is used after being dissolved in a non-aqueous solvent such as alcohol.
[0005]
However, when a titanium alkoxide is used as a titanium source, an organic solvent must be used, and the flash point of the titanium alkoxide is as low as 36 ° C., so that the operation of the production operation and the configuration of the apparatus are sufficiently safe. Measures must be taken. Another problem is that titanium alkoxide is an extremely expensive chemical.
[0006]
In such a situation, Japanese Patent Application Laid-Open No. 2000-159786 discloses that an organic titanium peroxo compound forms a stable aqueous solution, and a production method thereof is disclosed. In the above-mentioned publication, an organic titanium peroxo compound can be obtained by adding an organic complexing agent such as carboxylic acid to a solution of peroxotitanic acid dissolved by reacting aqueous hydrogen peroxide on titanium metal powder and dissolving the same. Is described. And the quality of the organotitanium peroxo compound manufactured by the batch type beaker experiment is shown.
[0007]
[Problems to be solved by the invention]
However, the product of the organotitanium peroxo compound described in JP-A-2000-159786 was obtained at a very small batch beaker test stage, and the method based on the batch beaker test was used as it is. Even when applied to equipment on an industrial scale, a good product having a certain composition cannot be stably obtained.
[0008]
In fact, according to the results of the present inventors using a large beaker as a batch reactor and repeatedly producing the organotitanium peroxo compound under the same conditions, the obtained organotitanium peroxo compound has a composition However, it is difficult to put it to practical use because it contains unreacted titanium.
[0009]
Thus, when the reaction is performed in a batch system, the reaction conditions in the tank are not always constant even if the scale of the reaction tank is slightly increased from a small beaker to a large beaker. . For this reason, in order to produce a good product having a certain composition on an industrial scale, it is necessary to establish a production method capable of always maintaining a constant reaction condition.
[0010]
An object of the present invention is to solve the above problems and to provide a method capable of stably producing a high-quality organic titanium peroxo compound and an apparatus for producing the same.
[0011]
[Means for Solving the Problems]
The present inventors conducted various studies while conducting experiments in order to elucidate the cause of the fact that the composition of the obtained organotitanium peroxo compound was different from production lot to production lot when using a batch type reaction vessel. Was done. As a result, it was found that many conditions need to be defined in order to stably produce a high-quality organic titanium peroxo compound. That is, according to the above study, in order to produce a high-quality organic titanium peroxo compound having very few impurities, the reaction temperature when reacting titanium metal with hydrogen peroxide and the reaction temperature between hydrogen peroxide and ammonia relative to titanium metal are considered. Mainly, the main condition is to maintain the ratio of the supply amounts of the components within an appropriate range.
[0012]
For this reason, a study was conducted on a production method capable of accurately controlling the above main reaction conditions within a predetermined range, and the raw materials (metal titanium, hydrogen peroxide, and ammonia) were continuously supplied at a predetermined ratio to cause a reaction. It was concluded that the system could control the above main reaction conditions. According to the continuous production method, the above-mentioned respective raw materials can be continuously supplied at a predetermined ratio so that the ratio of the raw materials present in the reaction tank is adjusted to a certain range. Further, since each raw material is continuously supplied at a predetermined ratio, the fluctuation of the reaction amount is small, and the fluctuation of the reaction temperature is also small. Therefore, the reaction proceeds stably, and a high-quality product can be manufactured.
[0013]
The present invention has been made based on the above findings, and has the following features.
[0014]
In the method for producing an organotitanium peroxo compound according to the first aspect of the present invention, the metal titanium powder, the hydrogen peroxide solution, and the ammonia water are continuously supplied into a dissolution reaction tank maintained at a predetermined temperature to supply the metal titanium. A first reaction step of dissolving and forming a solution of peroxotitanic acid; and adding a solution of one or more organic acids selected from the group consisting of carboxylic acids, acetylacetone, and amines to the solution of peroxotitanic acid discharged from the first reaction step. The method is characterized by comprising a second reaction step of continuously supplying a complexing agent to react with the peroxotitanic acid to form a solution of an organic titanium peroxo compound.
[0015]
The method for producing an organotitanium peroxo compound according to the second aspect of the present invention is characterized in that, in the first aspect of the present invention, the temperature in the dissolution reaction tank is maintained at 35 to 55 ° C.
[0016]
The method for producing an organotitanium peroxo compound according to the third aspect of the present invention is the method according to the first or second aspect, wherein the supply amount of hydrogen peroxide is 10 to 40 times the supply amount of the metal titanium powder in a molar ratio. It is characterized by a range.
[0017]
In the method for producing an organotitanium peroxo compound according to the invention of claim 4, the supply amount of ammonia is 5 to 20 times the supply amount of the metal titanium powder in any one of the inventions of claims 1 to 3. It is characterized by being within the range.
[0018]
The method for producing an organotitanium peroxo compound according to the invention of claim 5 is the method according to any one of claims 1 to 4, wherein the supply amount of the organic complexing agent is 1 in a molar ratio to the supply amount of the metal titanium powder. It is characterized by a range of up to three times.
[0019]
The method for producing an organotitanium peroxo compound according to claim 6 is the method according to any one of claims 1 to 5, wherein the residence time of the first reaction step for producing peroxotitanic acid is 10 minutes to 4 hours. It is characterized by having.
[0020]
The method for producing an organotitanium peroxo compound according to claim 7 is the method according to any one of claims 1 to 6, wherein the residence time of the second reaction step for producing the organotitanium peroxo compound is 10 minutes to 2 hours. It is characterized by being.
[0021]
The method for producing an organotitanium peroxo compound according to the invention of claim 8 is to concentrate the solution of the organotitanium peroxo compound obtained by the production method according to any one of claims 1 to 7 to form crystals of the organotitanium peroxo compound. It is characterized by obtaining.
[0022]
The apparatus for producing an organotitanium peroxo compound according to the ninth aspect of the present invention comprises at least two dissolution reaction tanks with a stirrer connected in series, and at least two dissolution reaction tanks connected in series connected to the last tank of the dissolution reaction tank. The tank has an organic complexing reaction tank with a stirrer, and the charge continuously supplied to the first tank of the dissolution reaction tank reacts while being stirred and is continuously discharged from the final tank of the organic complexing reaction tank. And each of the dissolution reaction tanks is configured to have a water-cooled structure.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
The method for producing an organic titanium peroxo compound according to the present invention includes a first reaction step of generating a solution of peroxotitanic acid, and a second reaction of generating a solution of the organic titanium peroxo compound from the peroxotitanic acid generated in the first reaction step. Process. In the first reaction step, the metal titanium powder, hydrogen peroxide solution, and ammonia water are continuously supplied into a dissolution reaction tank maintained at a predetermined temperature, so that the metal titanium is dissolved and the solution of peroxotitanic acid is dissolved. Is generated. In the second reaction step, one or more organic complexing agents selected from the group consisting of carboxylic acid, acetylacetone and amines are continuously supplied to the solution of peroxotitanic acid generated and discharged in the first reaction step. As a result, the peroxotitanic acid reacts with the organic complexing agent to form a solution of the organic titanium peroxo compound.
[0024]
Then, in the first reaction step, the metal titanium powder is mixed with the metal titanium powder so that the molar ratio of the hydrogen peroxide solution to the supply amount of the metal titanium powder and the molar ratio of the ammonia water to the supply amount of the metal titanium powder become predetermined values. Hydrogen oxide water and ammonia water are continuously supplied at predetermined flow rates into a dissolution reaction tank maintained at a predetermined temperature. Further, in the second reaction step, the carbon complex with respect to the supply amount of the metal titanium powder supplied to the first reaction step is added to the organic complexation reaction tank in which the solution of peroxotitanic acid discharged from the first reaction step is retained. The organic complexing agent is continuously supplied at a predetermined flow rate such that the molar ratio of one or more organic complexing agents selected from the group consisting of acids, acetylacetone, and amines is a predetermined value.
[0025]
Next, conditions for producing a high quality organic titanium peroxo compound will be described. The temperature in the dissolution reactor must be in the range of 35 to 55C, preferably 45 to 55C. The reason is as follows.
[0026]
In a dissolution reactor in which metal titanium and hydrogen peroxide are reacted to generate peroxotitanic acid, the reaction between the metal titanium and hydrogen peroxide causes severe heat generation, and the temperature rise due to the heat generation causes a reaction as described below. Has a significant effect on the progress of
[0027]
Hydrogen peroxide supplied for dissolving titanium metal is very unstable, so that a slight increase in temperature increases the partial pressure and decomposes. In addition, ammonia evaporates due to the temperature rise. However, when the metal titanium and the hydrogen peroxide react, the ammonia acts as a catalyst, so that the decrease in the amount of the ammonia prevents the progress of the reaction. Therefore, the reaction rate increases as the reaction temperature increases, but if the reaction temperature is too high, the decomposition of hydrogen peroxide and the evaporation of ammonia become intense, and hydrogen peroxide and ammonia decrease, and the raw materials involved in the reaction are reduced. Will be out of balance. Then, the generated peroxotitanic acid ((Ti (OH) ₃ O ₂ ) ⁻ ) Gels and precipitates. As a result, titanium becomes a precipitate and remains at the bottom of the reaction vessel, or metallic titanium remains unreacted.
[0028]
FIG. 2 shows the result when the temperature of the dissolution reaction tank was changed to react metal titanium with hydrogen peroxide. In the figure, the mark ○ indicates that the metal titanium powder or the precipitation product was not present at the bottom of the reaction tank after the reaction was completed, and the mark X was that the metal titanium powder or the precipitate was present at the bottom of the reaction tank. Show the case. According to the results of FIG. 2, precipitation occurs around the reaction temperature exceeding 55 ° C. Therefore, a range exceeding 55 ° C. indicates an inappropriate temperature range. However, if the temperature is too low, the reaction rate becomes slow. Therefore, the reaction temperature in the actual operation is preferably set in the range of 35 to 55 ° C, preferably 45 to 55 ° C.
[0029]
The boiling point of the reaction solution obtained by mixing 31% hydrogen peroxide and 28% ammonia water at a ratio of 4: 1, was 71 ° C. As described above, since the partial pressure of the reaction solution is very large, the preferable range of the reaction temperature is 45 to 55 ° C. as described above. In setting the temperature, the set temperature is determined in consideration of the composition of the reaction solution. There is a need to.
[0030]
In order to produce a high-quality organotitanium peroxo compound, the reaction temperature must be within the above range, but other conditions are as follows.
[0031]
Supply amount of hydrogen peroxide (molar ratio to supply amount of titanium metal powder)
If the molar ratio with respect to the metal titanium powder is less than 10 times, the oxidizing power of the hydrogen peroxide against the metal titanium becomes insufficient, so that the metal titanium cannot be completely dissolved. On the other hand, if it exceeds 40 times, the oxidation reaction of titanium by hydrogen peroxide proceeds explosively, so that it becomes difficult to control the operating conditions, for example, the reaction temperature within the standard, and a high quality organic titanium peroxo compound. Can not be obtained.
[0032]
About the supply amount of ammonia (molar ratio to the supply amount of titanium metal powder)
When the molar ratio with respect to the titanium metal powder is less than five times, the amount of ammonia that catalyzes the reaction between the titanium metal and the hydrogen peroxide becomes insufficient, whereby the oxidizing power of the metal titanium by the hydrogen peroxide becomes insufficient, and the metal titanium becomes insufficient. Cannot be completely dissolved. On the other hand, when the ratio exceeds 20 times, titanium ions produced by dissolving the metallic titanium once react with a large amount of hydroxide ions present in the strongly alkaline ammonia solution to generate titanium precipitates, thereby producing a high quality organic compound. No titanium peroxo compound can be obtained.
[0033]
Supply amount of organic complexing agent (molar ratio to supply amount of titanium metal powder)
If the molar ratio with respect to the metal titanium powder is less than 1, the presence of titanium ions that have not been combined with the organic complexing agent will cause some of the dissolved titanium to remain in an unstable state. Precipitates. On the other hand, if it exceeds three times, the viscosity of the reaction solution increases, and the reaction solution gels.
[0034]
About the residence time of the first reaction step
If the time is less than 10 minutes, the reaction between metallic titanium and hydrogen peroxide becomes insufficient, so that unreacted titanium remains. On the other hand, if it exceeds 4 hours, the produced aqueous peroxotitanic acid solution is unstable, so that it is hydrolyzed to form a precipitate, so that a high quality organic titanium peroxo compound cannot be obtained.
[0035]
About the residence time of the second reaction step
When the time is less than 10 minutes, the reaction between the peroxotitanic acid obtained in the first reaction step and the organic complexing agent becomes insufficient, so that unreacted peroxotitanic acid is decomposed to form a precipitate, and the quality is good. Organic titanium peroxo compounds cannot be obtained. If the reaction time between the peroxotitanic acid and the organic complexing agent is set in a range exceeding 10 minutes, there is no quality problem, but if the reaction time is too long, the reaction tank must be enlarged. Therefore, the upper limit of the reaction time is preferably not more than 2 hours.
[0036]
Next, the present invention will be specifically described based on the drawings.
[0037]
FIG. 1 is a flow diagram showing an example of an embodiment according to the configuration of the manufacturing apparatus of the present invention. FIG. 1 shows a case where titanium ammonium peroxocitrate is produced among the organic titanium peroxo compounds. This device is constituted by devices used in a first reaction step, a second reaction step, and a crystallization step.
[0038]
The apparatus in the first reaction step is configured as follows. 10 is a supply hopper for titanium metal powder, 11 is a metering and feeding device for titanium metal powder, 12 is a supply tank of hydrogen peroxide solution, 13 is a constant supply pump of hydrogen peroxide solution, 14 is a supply tank of ammonia water, and 15 is a supply tank of ammonia water. It is an ammonia water fixed supply pump. Reference numerals 20 and 21 denote dissolution reactors for reacting metal titanium powder with hydrogen peroxide to generate a solution of peroxotitanic acid, reference numeral 20 denotes a first dissolution reaction tank, and reference numeral 21 denotes a second dissolution reaction tank.
[0039]
The first dissolution reaction tank 20 and the second dissolution reaction tank 21 are connected in series by an overflow method, and include stirrs 22 and 23, respectively. Further, the first dissolution reaction tank 20 and the second dissolution reaction tank 21 are provided with water cooling jackets 24 and 25, respectively, and have a water cooling structure. The first dissolution reaction tank 20 and the second dissolution reaction tank 21 are provided with thermometers 26 and 27, respectively. The flow rate of the cooling water supplied to the water cooling jackets 24 and 25 is adjusted so that the temperature in the second dissolution reaction tank 21 becomes a set value. Reference numerals 28 and 29 denote flow controllers, and reference numeral 30 denotes a control device for transmitting a flow rate change instruction signal to the flow controllers 28 and 29 based on the temperature signals transmitted from the thermometers 26 and 27.
[0040]
The apparatus in the second reaction step is configured as follows. Reference numerals 40 and 41 denote organic complexing reaction tanks for reacting citric acid with peroxotitanic acid discharged from the second dissolution reaction tank 21 to produce ammonium peroxocitrate, 40 denotes a first organic complexing reaction tank, Reference numeral 41 denotes a second organic complexation reaction tank. The first organic complexation reaction tank 40 and the second organic complexation reaction tank 41 are connected in series by an overflow method, and include stirrs 42 and 43 and thermometers 44 and 45, respectively. 46 is a citric acid supply tank, and 47 is a citric acid constant supply pump.
[0041]
Since the reaction tanks are connected as described above, the charge continuously supplied to the first dissolution reaction tank 20 reacts while being stirred, flows into the second organic complexation reaction tank 41, and is continuously supplied. It is to be discharged to.
[0042]
The apparatus for the crystallization step is configured as follows. Reference numeral 50 denotes a receiving tank for the ammonium titanium peroxocitrate solution discharged from the second organic complexing reaction tank 41, and reference numeral 52 denotes a solution obtained by evaporating the solution sent from the receiving tank 50 by vacuum evaporation to concentrate the crystals of ammonium titanium peroxocitrate. This is a crystallization apparatus for precipitating the crystals.
[0043]
An ammonia absorption tower 60 for recovering ammonia from the gas generated in the dissolution reaction tanks 20 and 21 and the organic complexation reaction tanks 40 and 41 is provided. 61 is an absorption liquid circulation pump.
[0044]
In FIG. 1, excess hydrogen peroxide and ammonia water with respect to the metal titanium are supplied to the first dissolution reaction tank 20 together with the metal titanium. However, the hydrogen peroxide is easily decomposed, Since water tends to evaporate, if it is desired to reduce the amount of these solutions decomposed or evaporated and depleted while staying in the first dissolution reaction tank 20, hydrogen peroxide and ammonia water should be used. It is preferable to supply the first and second dissolution reaction tanks 20 and 21 separately.
[0045]
In FIG. 1, the ammonia supplied to the first dissolution reaction tank 20 is ammonia water, but ammonia gas may be supplied instead of ammonia water.
[0046]
An operation method of the apparatus configured as described above will be described. In the first reaction step, the metal titanium powder, the hydrogen peroxide solution, and the ammonia water are respectively supplied at predetermined flow rates by the metering and feeding device 11, the hydrogen peroxide solution metering pump 13, and the ammonia water metering pump 15 for the metal titanium powder. To the first dissolution reaction tank 20 continuously. In the first dissolution reaction tank 20, metal titanium and hydrogen peroxide react to generate peroxotitanic acid, and this reaction generates severe heat. However, by controlling the flow rate of cooling water to the water cooling jacket 24, temperature control is performed. The temperature in one dissolution reaction tank 20 is maintained at a predetermined value within a range of 35 to 55 ° C, preferably 45 to 55 ° C.
[0047]
The first dissolution reactor 20 alone is designed so that the reaction between metallic titanium and hydrogen peroxide is not completed. One of the reasons is that the reaction heat is rapidly generated by the reaction between titanium metal and hydrogen peroxide, and if the reaction is completed only in the first dissolution reaction tank 20, the reaction occurs rapidly. This is because the fluctuation of the distance becomes large. For this reason, unreacted metal titanium and hydrogen peroxide flow into the second dissolution reaction tank 21 and the reaction is performed over the two tanks.
[0048]
By performing the reaction in two tanks in this manner, the amount of reaction performed in the same tank is limited, and the generation of rapid reaction heat is suppressed. Further, in the continuous type apparatus, even if a part of the raw material charged into the first dissolution reaction tank is discharged through a short path, the reaction for the short path must be completed. Requires two or more tanks.
[0049]
In the second reaction step, the solution overflowing from the second dissolution reaction tank 21 flows into the first organic complexation reaction tank 40, where a predetermined flow rate of citric acid is continuously supplied by the citric acid quantitative supply pump 47. Supplied to In the first organic complexation reaction tank 40, the reaction between peroxotitanic acid and citric acid generated in the dissolution reaction tank is performed, and titanium ammonium peroxocitrate is generated. This reaction is completed in the next second organic complexing reaction tank 40, and the solution flows into the receiving tank 50 and is temporarily stored.
[0050]
In the crystallization step, the solution of ammonium titanium peroxocitrate stored in the receiving tank 50 is sent to the crystallizer 52 and concentrated in vacuo at a temperature of about 60 ° C. By this concentration, crystals of titanium ammonium peroxocitrate are obtained. By crystallizing and removing titanium ammonium peroxocitrate, a high-purity product can be obtained.
[0051]
The gas generated in the dissolution reaction tanks 20, 21 and the organic complexation reaction tanks 40, 41 is introduced into the ammonia absorption tower 60, and ammonia water is recovered. This ammonia water can be used as a part of the ammonia source supplied to the first dissolution reaction tank 20. The exhaust gas is sent to a gas cleaning device (not shown) to be purified.
[0052]
【Example】
[Example 1]
A bench-scale continuous manufacturing apparatus having a basic configuration similar to that of FIG. 1 was manufactured, and this apparatus was used to manufacture titanium ammonium peroxocitrate.
[0053]
The raw material supply was as follows. 0.6 g / min of titanium metal powder (Ti 99.9%, particle size 100 mesh pass), 30 g / min of 31% aqueous hydrogen peroxide and 7.5 g / min of 28% aqueous ammonia are continuously supplied to the first dissolution reaction tank. And the temperature of the first dissolution reaction tank and the second dissolution reaction tank was maintained at 50 ± 5 ° C. In addition, when the supply amount of each of the above-mentioned raw materials was shown by a molar ratio with respect to the supply amount of metallic titanium, hydrogen peroxide was 21.8 times and ammonia was 9.9 times.
[0054]
Then, a 10% aqueous citric acid solution was added to the first organic complexation reaction tank at a molar ratio of 1.2 times the amount of titanium metal to cause a reaction. As a result, a yellow aqueous solution was obtained from the second organic complexation reaction tank.
[0055]
This aqueous solution was placed in a crystallizer (rotary evaporator) and evaporated at 60 ° C. in vacuo to precipitate crystals. Next, the crystal was heated at 160 ° C. to make it free of water of crystallization. This sample was used as a sample for quality evaluation.
[0056]
Then, in order to evaluate the quality of the sample obtained as described above, using a 500 ml beaker as a reaction tank, a titanium ammonium peroxocitrate was manufactured by a batch method, and this sample was used as a reference material for quality evaluation. . The reason is that, as described above, it has been found that a product of a quality that can be practically used is obtained if the reaction tank is of a beaker scale, even if it is manufactured in a batch process. Because it is.
[0057]
Production of ammonium titanium peroxocitrate by a batch system using a beaker as a reaction tank was performed as follows. 0.25 g of titanium metal powder (mesh pass), 20 ml of 30% aqueous hydrogen peroxide, and 5 ml of 30% aqueous ammonia are mixed in a beaker, and while cooling in a water bath, the metallic titanium is dissolved to give a yellow titanium peroxo solution. Got. Next, 1 mol or more of citric acid with respect to titanium was added to the obtained solution. After the added citric acid was completely dissolved, the beaker was placed on a hot plate and dried by heating at 80 ° C. to obtain yellow crystals. This sample was used as a reference material for quality evaluation.
[0058]
Table 1 shows the results of elemental analysis of the sample of Example 1 manufactured as described above and the sample manufactured by the beaker / batch method.
[0059]
[Table 1]

[0060]
Then, X-ray diffraction, Raman spectroscopy, solid-state ¹³ As a result of measurement by C-NMR spectroscopy, the target compound, titanium ammonium peroxocitrate ((NH ₄ ) ₂ [Ti (C ₆ H ₄ O ₇ ) O ₂ ] ・ 2H ₂ O) was confirmed.
[0061]
FIG. 3 shows an X-ray diffraction pattern of the sample obtained in Example 1. FIG. 3 shows the results of the beaker / batch system together with the results of Example 1. The peak of the sample of Example 1 is sharper than that of the sample manufactured by the beaker / batch method, and fine peaks are observed one by one. Therefore, the samples of the examples have very high crystallinity and high purity.
[0062]
According to the above-described respective measurement results, the measurement results of the sample of Example 1 and the sample of the beaker / batch type are almost the same, but the sample of Example is superior in crystallinity. From this, it was confirmed that the quality of the sample of the example was equal to or higher than that of the beaker / batch type sample, which is a quality that can be practically used.
[0063]
[Comparative Example 1]
Using a large beaker (2 liters) as a batch type reaction tank, titanium ammonium peroxocitrate was produced batchwise. The production conditions were the same as those in Example 1, except that the feed ratio of the raw materials and the reaction temperature were the same as those in Example 1 except that the batch system was used. At this time, in order to examine the reproducibility of the obtained sample quality, the production was performed twice.
[0064]
10 g of titanium metal powder, 800 ml of 30% hydrogen peroxide solution and 200 ml of 30% ammonia water were mixed in a 2 liter beaker, and the titanium metal was dissolved while cooling in a water bath to obtain a yellow titanium peroxo solution. Next, 1 mol or more of citric acid with respect to titanium was added to the obtained solution. After the added citric acid was completely dissolved, the beaker was placed on a hot plate and dried by heating at 80 ° C. to obtain yellow crystals (production of lot 1). A second production was performed by performing the same operation as above (production of lot 2).
[0065]
FIG. 4 shows the solid obtained in Comparative Example 1. ¹³ The measurement result by C-NMR is shown. In the lower part of FIG. 4, the measurement results of the sample of Example 1 are also shown for comparison.
[0066]
According to FIG. 4, the measurement results of the two samples (lot 1 and lot 2) obtained in Comparative Example 1 show that the intensity ratios of the peaks marked b and b ′ are different, and that c , C ′, d ′ are different in overall shape. As described above, when the production method is a batch type, even if there is only a difference in the scale of the apparatus such that the reaction tank is reduced from 500 ml to 2 liters, it is shown that a product of the same quality cannot be obtained with good reproducibility. . Also, two peaks b and b 'were originally observed where one peak should have been, indicating that the sample of Comparative Example 1 did not consist of a single compound. Although a and a 'and c and c' are peaks which should be observed separately, the compounds of Comparative Example 1 contain compounds having various compositions because they are broad peaks. Or the presence of titanium hydrolysis products.
[0067]
In contrast, the measurement result of the sample of Example 1 had a very sharp peak, indicating that a single compound was obtained.
[0068]
According to the above results, in the case of the batch production method, if the scale of the reaction tank is increased, it is difficult to control the reaction conditions in the tank at a constant level, and thus it is difficult to obtain a product that can be put to practical use. Is determined. For this reason, when producing titanium ammonium peroxocitrate on an industrial scale, it is difficult to employ a batch production method.
[0069]
[Example 2]
The same equipment as in Example 1 was used under the same conditions as in Example 1 except that the titanium raw material was replaced by titanium powder as a reagent and industrial metal titanium (Toho Titanium Co., Ltd., Ti 99%) was supplied. Tests were made to produce ammonium peroxocitrate.
[0070]
In this test, the solution discharged from the final reaction tank had no difference in appearance from the solution obtained in Example 1, and no abnormal reaction was observed. Also, in the measurement for evaluating the compound composition, crystal structure, crystallinity and the like of the crystals obtained by concentrating the solution in vacuo, the results were in agreement with the results of Example 1 within an error range. As a result, it was determined that titanium ammonium peroxocitrate produced using titanium metal for industrial raw materials as a raw material can be sufficiently used as a raw material for a ferroelectric nonvolatile memory, a photocatalyst, and the like.
[0071]
【The invention's effect】
According to the present invention, organic titanium peroxo compounds used as raw materials for ferroelectric nonvolatile memories and photocatalysts can be mass-produced at low cost, and high-quality products can be stably manufactured.
[Brief description of the drawings]
FIG. 1 is a flow diagram showing an example of an embodiment according to a configuration of a manufacturing apparatus of the present invention.
FIG. 2 is a diagram showing the effect of reaction temperature when reacting metallic titanium with hydrogen peroxide.
FIG. 3 is a view showing an X-ray diffraction pattern of a sample obtained in an example.
FIG. 4 is a solid obtained in Comparative Example 1. ¹³ It is a figure which shows the measurement result by C-NMR.
[Explanation of symbols]
10. Supply hopper for titanium metal powder
11 Quantitative metering and feeding device for metallic titanium powder
12 Hydrogen peroxide water supply tank
13 Hydrogen peroxide solution fixed supply pump
14 Ammonia water supply tank
15 Aqueous ammonia water supply pump
20 First dissolution reactor
21 Second dissolution reactor
22,23 stirrer
24,25 water cooling jacket
26,27 thermometer
28, 29 Flow controller
30 Control device
40 First Organic Complexation Reaction Tank
41 Second organic complexation reactor
42, 43 stirrer
46 Citric acid supply tank
47 Citric acid metering pump
52 Crystallizer
60 Ammonia absorption tower

Claims (9)

A first reaction step of continuously supplying metal titanium powder, hydrogen peroxide solution and ammonia water into a dissolution reaction tank maintained at a predetermined temperature to dissolve metal titanium and generate a solution of peroxotitanic acid; The carboxylic acid, acetylacetone, and one or more organic complexing agents selected from the group consisting of amines are continuously supplied to the solution of peroxotitanic acid discharged from the first reaction step, A method for continuously producing an organic titanium peroxo compound, comprising a second reaction step of reacting to form a solution of an organic titanium peroxo compound. The method for continuously producing an organotitanium peroxo compound according to claim 1, wherein the temperature in the dissolution reactor is maintained at 35 to 55C. 3. The continuous production method of an organic titanium peroxo compound according to claim 1, wherein the supply amount of hydrogen peroxide is in a range of 10 to 40 times in molar ratio with respect to the supply amount of the titanium metal powder. . The organic titanium peroxo compound according to any one of claims 1 to 3, wherein the supply amount of ammonia is in a range of 5 to 20 times in molar ratio with respect to the supply amount of the titanium metal powder. Continuous manufacturing method. The organic titanium according to any one of claims 1 to 4, wherein the supply amount of the organic complexing agent is in a range of 1 to 3 times in molar ratio with respect to the supply amount of the metal titanium powder. A method for continuously producing peroxo compounds. The continuous production of the organic titanium peroxo compound according to any one of claims 1 to 5, wherein the residence time of the first reaction step for producing peroxotitanic acid is 10 minutes to 4 hours. Method. The continuous time of the organic titanium peroxo compound according to any one of claims 1 to 6, wherein the residence time of the second reaction step for producing the organic titanium peroxo compound is 10 minutes to 2 hours. Production method. A method for continuously producing an organic titanium peroxo compound, comprising concentrating a solution of an organic titanium peroxo compound obtained by the method according to any one of claims 1 to 7, thereby obtaining crystals of the organic titanium peroxo compound. A dissolution reaction tank having at least two dissolution reaction tanks with a stirrer connected in series, and at least two organic complexation reaction tanks with a stirrer connected to the last tank of the dissolution reaction tank and connected in series; The charge continuously supplied to the first tank of the organic complexing reaction tank is configured to react while being stirred, and to be continuously discharged from the last tank of the organic complexation reaction tank. An apparatus for producing an organic titanium peroxo compound, wherein the apparatus has a water-cooled structure.

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