JPH06145120A - Production of amino polycarboxylic acid ferric complex ammonium salt - Google Patents

Abstract

PURPOSE:To efficiently produce an amino polycarboxylic acid ferric complex ammonium salt useful for photographic chemicals and fine ingredient of fertilizers in high purity and in high yield. CONSTITUTION:An aqueous solution containing an amino polycarboxylic acid ferric complex and ammonia or an aqueous solution of an amino polycarboxylic acid ferrous complex ammonium salt is oxidized with a peroxo compound such as peroxo disulfuric acid, peroxo phosphoric acid, peroxo acetic acid, peroxo benzoic acid, peroxo carbonic acid, their ammonium salts or sodium salts at 40-90 deg.C, preferably 50-80 deg.C, to produce the amino polycarboxylic acid ferric complex ammonium salt. Ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, 1,3-propanediaminetetraacetic acid, 1,2- propanediaminetetraacetic acid, 1,4-butanediaminetetraacetic acid and 2,2- dimethylpropanediaminetetraacetic acid are especially useful as the amino polycarboxylic acid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an ammonium salt of ferric aminopolycarboxylic acid complex, and more specifically, an aqueous solution containing ferrous aminopolycarboxylic acid complex and ammonia or ferrous aminopolycarboxylic acid. The present invention relates to a method for industrially advantageously producing a corresponding ferric complex ammonium salt with high purity and high yield by oxidizing an aqueous solution of a complex ammonium salt with a peroxo compound. Aminopolycarboxylic acid ferric complex ammonium salt is a compound useful as a photographic chemical and a trace ingredient fertilizer.

[0002]

2. Description of the Related Art Conventionally, as a method for producing an aminopolycarboxylic acid ferric iron complex ammonium salt, for example, aminopolycarboxylic acid containing ammonia water and iron oxide (Fe ₃ O _3
4 ) and a method of reacting with (US Pat. No. 4,364,87)
No. 1), a method of reacting ferric chloride (FeCl ₃ ) with an ammonium salt of 1,3-propanediaminetetraacetic acid and further adding aqueous ammonia (JP-A-63-28415).
No. 4), an alkaline salt of aminopolycarboxylic acid and ferrous sulfate are reacted in an aqueous medium to form a ferrous aminopolycarboxylic acid complex salt, which is oxidized with molecular oxygen and then the reaction solution is treated with sulfuric acid. A method of neutralizing (JP-A-58-21690) or a method of oxidizing an aqueous solution of an aminopolycarboxylic acid ferrous iron complex or an aminopolycarboxylic acid ferrous iron complex ammonium salt with molecular oxygen on the acidic side (Japanese Patent Laid-Open Publication No. Sho-58-1999). 64-71842).

However, the method using iron oxide (Fe ₃ O ₄ ) is difficult to ionize Fe ₃ O ₄ into a water-soluble iron ion, and the composition of iron oxide is a mixture of divalent and trivalent iron oxides. Therefore, it is unavoidable that a divalent iron complex is mixed as an impurity in the trivalent iron complex, and the method using iron chloride (FeCl ₃ ) has a strong corrosive property of the raw material FeCl ₃ , and There are drawbacks in that it is significantly restricted in terms of material and maintenance, and that the crystals of the target product are inevitably contaminated with chloride ions. Further, the method of oxidizing a ferrous aminopolycarboxylic acid complex with molecular oxygen has a high yield of a target product and is free from chlorine ion contamination, but on the other hand, the rate of oxidation depends on the pH of the reaction solution before the oxidation reaction. Since it is different, it is necessary to adjust the optimum pH in a timely manner during the reaction, and it takes a very long time to oxidize. For example, in order to achieve an oxidation rate of 95% or more by performing air oxidation of the ethylenediaminetetraacetic acid ferrous iron complex or PH in the reaction solution on the alkaline side, it takes 4 to 5 hours at a temperature of 60 to 65 ° C. It takes a long time, and even on the acidic side at a temperature of 70 to 75 ° C, 1 to 3
It takes time.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is a method for industrially producing a ferric aminopolycarboxylic acid ammonium complex salt. Specifically, the aminopolycarboxylic acid ferric complex ammonium salt, which does not contain a divalent iron complex as an impurity and is not contaminated with chloride ions, has a high purity, a high yield, and an efficiency. It is to provide a method that can be well manufactured.

[0005]

DISCLOSURE OF THE INVENTION As a result of intensive studies to achieve the above object, the present inventors have found that peroxodisulfuric acid, peroxophosphoric acid, and peroxodisulfuric acid can be used to oxidize ferrous aminopolycarboxylic acid complexes or ammonium salts thereof. It has been found that when a peroxo compound such as benzoic acid or an ammonium salt thereof is used as an oxidizing agent, the aminopolycarboxylic acid ferric complex ammonium salt can be produced with a short oxidation time, high purity and high yield. The present invention has been achieved based on such knowledge.

The present invention is characterized in that an aqueous solution containing a ferrous aminopolycarboxylic acid complex and ammonium or an aqueous solution of an aminopolycarboxylic acid ferrous complex ammonium salt is oxidized with a peroxo compound. The present invention relates to a method for producing an iron complex ammonium salt.

The aminopolycarboxylic acid ferrous iron complex or aminopolycarboxylic acid ferrous iron complex ammonium salt used in the present invention, which specifically explains the present invention, can be produced by any method. It can be easily produced by reacting aminopolycarboxylic acid with ammonia and ferrous sulfate in an aqueous medium. For example,
It is obtained by adding aminopolycarboxylic acid, aqueous ammonia and ferrous sulfate to a water solvent and heating to completely dissolve. The amount of aminopolycarboxylic acid used is usually 1.0 to 1.1 mol, preferably 1.0, relative to ferrous sulfate.
The range of 3 to 1.07 mol is preferable, and the amount of ammonia used is within the range of 6 mol or less, preferably 1.
The range of 0 to 4.5 mol is preferable, and the amount of water used as an aqueous medium is 20 to 100 mol, preferably 45 to 100 mol, based on ferrous sulfate, in combination with the amount of water transferred from ammonia water.
A range of 75 mol is preferred. The reaction temperature is usually 40 to 90.
The temperature is in the range of ℃, preferably in the range of 50 to 80 ℃. This reaction produces an aminopolycarboxylic acid ferrous iron complex or an aminopolycarboxylic acid ferrous iron complex ammonium salt depending on the reaction molar ratio of ammonia.

The aminopolycarboxylic acids which can be used in the above production are ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, iminodiacetic acid), 1,3-propanediaminetetraacetic acid, 1,4-butanediaminetetraacetic acid and 1-methyl. Propanediaminetetraacetic acid, 2-methylpropanediaminetetraacetic acid, 2,2-dimethylpropanediaminetetraacetic acid,
1,2-dimethylethylenediaminetetraacetic acid, 1,2-dimethylpropanediaminetetraacetic acid, 1,3-dimethylpropanediaminetetraacetic acid, 1,2-propylenediaminetetraacetic acid (PPTA), nitrilotriacetic acid, hydroxyethyl-
Examples thereof include iminodiacetic acid and ethylenediamine-N-hydroxyethyl-N, N ', N'triacetic acid, and among them, particularly useful industrially, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, 1,3
-Propanediaminetetraacetic acid, 1,2-propanediaminetetraacetic acid, 1,4-butanediaminetetraacetic acid and 2,2-
Dimethyl propane diamine tetraacetic acid can be mentioned.

Examples of the peroxo compound used in the present invention include inorganic peroxo compounds such as peroxodisulfate, ammonium peroxodisulfate, peroxophosphoric acid, ammonium peroxophosphate and sodium peroxophosphate, as well as peroxoacetic acid and sodium peroxoacetate. Examples thereof include organic peroxo compounds such as peroxocarbonic acid, peroxobenzoic acid, and peroxobenzoic acid sodium salt. Preferably, peroxodisulfate, ammonium peroxodisulfate, peroxocarbonate, peroxobenzoic acid and the like are used.

In order to oxidize an aminopolycarboxylic acid ferrous iron complex or an aminopolycarboxylic acid ferrous iron complex ammonium salt into its corresponding ferric iron salt, an aqueous solution of a raw material is subjected to an oxidation reaction using a peroxo compound. The above complex formation reaction solution can be used as it is as the raw material aqueous solution, and the peroxo compound can be added thereto. This oxidation reaction can be carried out in any pH range from the acidic side to the alkaline side of the pH of the reaction solution.
The reaction in the neutral to weakly alkaline region is preferable because the amount of the peroxo compound used can be reduced. At that time, the pH adjuster to be used is not particularly limited, but it is necessary to select one that does not deteriorate the purity of the product. Usually, the starting material of the present invention uses ammonia and ferrous sulfate as the aminopolycarboxylic acid, so ammonia or ammonia water is suitable as the alkali, and sulfuric acid is suitable as the acid.

The amount of the peroxo compound used may be appropriately selected within the range of 1 to 2 equivalents with respect to the aminopolycarboxylic acid ferrous iron complex or aminopolycarboxylic acid ferrous iron ammonium salt, and the pH of the reaction solution may be adjusted. Is 7.5-8.5
The theoretical equivalent is sufficient in the range of.

The rate of oxidation of the aminopolycarboxylic acid ferrous iron complex or aminopolycarboxylic acid ferrous iron ammonium salt by the peroxo compound is sufficiently high even when the temperature of the reaction solution is room temperature. Without any reaction, the reaction proceeds even at room temperature.

In the present invention, after completion of the oxidation reaction, the reaction liquid is ammonia or sulfuric acid to adjust the pH to the desired product.
Adjust to. For example, in the ethylenediaminetetraacetic acid ferric complex ammonium salt, the PH value is preferably 4.0 to 5.0, and in the propylenediaminetetraacetic acid ferric complex ammonium salt, the PH value is 4.5 to 5.5. It is suitable.

By adjusting the PH value of the reaction solution, the concentration of ammonium sulfate as a by-product in the reaction solution is increased, and this is used to facilitate the crystallization of the desired product crystals from the reaction solution. For example, since the solubility of ethylenediaminetetraacetic acid ferric complex ammonium salt in water (PH = 4.5) is as large as about 35% by weight at 20 ° C., the crystallization rate is low when the reaction solution is simply cooled. Therefore, as a method of increasing the crystallization rate of the aminopolycarboxylic acid ferric complex ammonium salt, it is appropriate to effectively utilize the salting-out effect by increasing the concentration of ammonium sulfate as a by-product. The effective ammonium sulfate concentration for the salting-out effect in the reaction solution is in the range of 14 to 26% by weight, preferably 16 to 24% by weight.

After adjusting the PH value of the reaction solution, it is concentrated to an appropriate ammonium sulfate concentration and cooled. Crystals of the crystallized aminopolycarboxylic acid ferric complex ammonium salt are separated from the mother liquor by a centrifuge or the like, washed with water to wash the ammonium sulfate attached to the crystals, and dried to obtain a product. The mother liquor after separation of the aminopolycarboxylic acid ferric complex ammonium salt can be recycled and used as a reaction liquid for the next reaction.

[0016]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples. Example 1 A 1-liter cylindrical flask having a stirrer, a thermometer and a raw material charging port was placed in a 1,3-propanediaminetetraacetic acid (PD).
TA) (161.9 g), water (377.8 g) and 15% aqueous ammonia (249.8 g) were charged, and the mixture was stirred and mixed at room temperature to dissolve. Next, ferrous sulfate (purity 99.5%) 139.7
After adding g to dissolve by heating, cool to room temperature and pH with deionized water.
The value was adjusted to 8.0. The reaction solution was stirred at room temperature for about 30 minutes, and ammonium persulfate 57.05 g (0.0.
25 mol) was added to complete the oxidation reaction. P at this time
The decomposition of DTA was 2.7%. Thereafter, the pressure was reduced and the reaction solution was concentrated so that the concentration of ammonium sulfate was about 25.0 wt%. After adjusting the pH to 5.1 with sulfuric acid, the solution was cooled to 15 ° C. to precipitate a ferric complex ammonium salt. The precipitated crystals are separated by a centrifuge to obtain 25.0 wt of wet crystals.
% Water and dried at 70 ° C. for 1 hour 30 minutes. The obtained 1,3-propanediaminetetraacetic acid ferric complex ammonium salt is a yellow plate crystal and its yield is 16
The amount was 1.6 g and the yield was 84.8% (based on ferrous sulfate).

Example 2 Ethylenediaminetetraacetic acid (EDTA) 161.0 was placed in a 1 liter cylindrical flask equipped with the same equipment as in Example 1.
g, water 375.6 g and 15% aqueous ammonia 227.
7 g was charged, and they were dissolved by stirring and mixing at room temperature. Next, 139.7 g of ferrous sulfate (purity 99.5%) was added and dissolved by heating. To this reaction solution, under stirring, ammonium persulfate 5 was added.
The oxidation reaction was completed by adding 7.05 g (0.25 mol) over about 30 minutes. The decomposition of EDTA at this time is 3.
It was 0%. Thereafter, the pressure was reduced, and the reaction solution was concentrated so that the concentration of ammonium sulfate was about 25.0 wt%. PH with sulfuric acid
The solution was adjusted to 4.0 and cooled to a liquid temperature of 10 ° C to precipitate a ferric complex ammonium salt. The crystallized crystals were separated by a centrifuge, washed with 25.0 wt% of wet crystals, and then dried at a temperature of 55 ° C for 2 hours. The obtained ethylenediaminetetraacetic acid ferric complex ammonium salt was yellowish brown plate crystals, and the yield was 159.5 g, and the yield was 83.6% (based on ferrous sulfate).

Example 3 1,3-Propanediaminetetraacetic acid (PDTA) 16 in a 1 liter cylindrical flask equipped with the same equipment as in Example 1.
1.9 g, water 377.8 g and 15% ammonia water 2
49.8 g was charged, and they were dissolved by stirring and mixing at room temperature. Next, 139.7 g of ferrous sulfate (purity 99.5%) was added and dissolved by heating, followed by cooling to room temperature and pH value of 8.
Adjusted to 0. To this reaction solution, 100.74 g (0.73 mol) of perbenzoic acid was added at room temperature over about 30 minutes with stirring to complete the oxidation reaction. The decomposition of PDTA at this time was 3.0%. After that, benzoic acid which precipitates as PH3.5 with sulfuric acid is separated, adjusted to PH5.0 with aqueous ammonia and concentrated under reduced pressure, and the ammonium sulfate concentration in the reaction solution is about 25.0.
It was adjusted to be wt%. The solution was cooled to 15 ° C to precipitate 1,3-propanediaminetetraacetic acid ferric complex ammonium salt. The precipitated crystals are separated by a centrifuge and washed with 25.0 wt% of wet crystals, and then the temperature is set to 70.
It was dried at ° C for 1 hour and 30 minutes. The obtained 1,3-propanediaminetetraacetic acid ferric complex ammonium salt is a yellow plate crystal, and the amount thereof is 133.4 g, and the yield is 70.0%.
(Relative to ferrous sulfate).

Example 4 A 1 liter cylindrical flask equipped with the same equipment as in Example 1 was charged with diethylenetriaminepentaacetic acid (DTPA) 207.
5 g, water 375.6 g and 15% ammonia water 22
7.7 g was charged, and they were dissolved by stirring and mixing at room temperature. next,
139.7 g of ferrous sulfate (purity 99.5%) was added and dissolved by heating. With stirring, 57.05 g (0.25 mol) of ammonium persulfate was added to this reaction solution over a period of about 30 minutes to complete the oxidation reaction. The decomposition of DTPA at this time was 2.8%. Thereafter, the pressure was reduced, and the reaction solution was concentrated so that the concentration of ammonium sulfate was about 25.0 wt%. P with sulfuric acid
The solution was adjusted to H2.5 and cooled to a liquid temperature of 20 ° C. to precipitate a ferric complex ammonium salt. The crystallized crystals were separated by a centrifuge, washed with 25.0 wt% of wet crystals, and then dried at a temperature of 55 ° C for 2 hours. The obtained diethylenetriaminepentaacetic acid ferric complex ammonium salt was tan crystals, and the amount thereof was 225.2 g, and the yield was 93.6% (based on ferrous sulfate).

Comparative Example 1 1,3-in a 1-liter cylindrical flask equipped with a stirrer, an air-blowing ball filter, a thermometer and a raw material inlet.
160.8 g of propanediaminetetraacetic acid (PDTA), 380.7 g of water and 249.8 g of 15% aqueous ammonia were charged, and the mixture was stirred and mixed at room temperature to dissolve. Next, 139.7 g of ferrous sulfate (purity 99.5%) was added and dissolved by heating, followed by cooling to room temperature and adjusting the pH value to 3.5 with sulfuric acid.
This reaction solution is heated to 75 to 80 ° C and blown with a ball filter to maintain a pH of 3.5 at 9 liters /
Minute air was blown in for 20 hours to complete the oxidation reaction. The decomposition of PDTA at this time was 15.4%. Thereafter, 66.4 g of ammonium sulfate was added as a salting-out agent, the pressure was reduced, and the reaction solution was concentrated so that the concentration of ammonium sulfate was about 25.0 wt%. The liquid temperature was cooled to 15 ° C. to deposit a ferric complex ammonium salt. The precipitated crystals were separated by a centrifuge, washed with 25.0 wt% of wet crystals, and dried at 70 ° C. for 1 hour 30 minutes. The obtained 1,3-propanediaminetetraacetic acid ferric iron complex ammonium salt is a yellow plate crystal,
The yield was 135.0 g and the yield was 74.2% (based on ferrous sulfate).

Comparative Example 2 1,1, -propanediaminetetraacetic acid (PDTA) 1 was placed in a 1-liter cylindrical flask equipped with the same apparatus as in Example 1.
61.9 g, 377.8 g of water and 249.8 g of 15% ammonia water were charged, and they were dissolved by stirring and mixing at room temperature. Next, 139.7 g of ferrous sulfate (purity 99.5%) was added and dissolved by heating, then cooled to room temperature and the pH value was adjusted to 4 with sulfuric acid.
Adjusted to 5. . The reaction solution was stirred at room temperature for about 30 minutes with stirring.
85g of 20% hydrogen peroxide solution (0.50mo
1) was added to complete the oxidation reaction. The decomposition of PDTA at this time was 32%. After that, PH with ammonia water
It was adjusted to 5.0 and then concentrated under reduced pressure to prepare an ammonium sulfate concentration of about 25.0 wt% in the reaction solution. Liquid temperature 1
The mixture was cooled to 5 ° C to precipitate a ferric complex ammonium salt. The precipitated crystals are separated by a centrifuge and the wet crystals are
After washing with 5.0 wt% water, at a temperature of 70 ° C for 1 hour 3
Dry for 0 minutes. The obtained 1,3-propanediaminetetraacetic acid ferric complex ammonium salt was a yellow plate crystal, and the yield was 88.9 g, and the yield was 46.7% (based on ferrous sulfate). .

Comparative Example 3 Ethylenediaminetetraacetic acid (EDTA) 161.9 was placed in a 1 liter cylindrical flask equipped with the same apparatus as in Example 1.
g, water 377.8 g and 15% aqueous ammonia 249.
8 g was charged, and they were dissolved by stirring and mixing at room temperature. Next, 139.7 g of ferrous sulfate (purity 99.5%) was added and dissolved by heating, followed by cooling to room temperature and adjusting the pH value to 7.0 with ammonium hydroxide. . 104 g of sodium percarbonate was added to this reaction solution at room temperature with stirring while adding sulfuric acid to maintain the pH value at 7.0.
(0.33 mol) was added over about 30 minutes to complete the oxidation reaction. The decomposition of EDTA at this time was 3.1%, and iron hydroxide was a by-product. Then, the pH was adjusted to 5.0 with sulfuric acid, the iron hydroxide produced as a by-product was filtered off, and then concentrated under reduced pressure. The liquid temperature was cooled to 15 ° C. to deposit a ferric complex ammonium salt. Separate the precipitated crystals with a centrifuge,
After washing with 25.0 wt% of wet crystals, the temperature is 70 ° C.
And dried for 1 hour and 30 minutes. The obtained ethylenediaminetetraacetic acid ferric complex ammonium salt was yellow plate crystals, and the yield was 127.8 g, and the yield was 67.0% (based on ferrous sulfate).

[0023]

The aminopolycarboxylic acid ferric iron complex ammonium salt produced by the method of the present invention is a free iron oxide,
Aminopolycarboxylic acid ferrous iron complex, aminopolycarboxylic acid ferrous iron complex ammonium salt and the like are not contaminated, and ammonium sulfate produced as a by-product can be obtained in high purity and high yield, which is excellent as an industrial production method. It is a thing. In the conventional air oxidation method, EDTA / ferrous iron complex or EDTA is used.
-To oxidize the ferrous complex ammonium salt under heating at 70 ° C or higher for 1 to 5 hours, PDTA-ferrous complex or PDTA-
It took 20 hours or more to reach the ferrous complex ammonium salt, but if this is oxidized with a peroxo compound, it is not necessary to heat it, and the reaction rate is 99% in about 30 minutes.
The above is achieved, and the effect of producing a high-purity ferric complex ammonium salt is obtained. Further, although it is unavoidable that the decomposition of aminopolycarboxylic acid occurs in the oxidation reaction, the present invention can suppress this to about 1/5 or less.

Claims (3)

[Claims] 1. A ferric aminopolycarboxylic acid complex characterized in that an aqueous solution containing an aminopolycarboxylic acid ferrous complex and ammonia or an aqueous solution of an aminopolycarboxylic acid ferrous complex ammonium salt is oxidized by a peroxo compound. Method for producing ammonium salt 2. The peroxo compound is peroxodisulfate,
Ammonium peroxodisulfate, peroxophosphoric acid, ammonium peroxophosphate, peroxophosphoric acid sodium salt, peroxoacetic acid, peroxoacetic acid sodium salt,
The method according to claim 1, which is at least one compound selected from the group consisting of peroxocarbonic acid, peroxobenzoic acid and peroxobenzoic acid sodium salt. 3. A ferrous aminopolycarboxylic acid complex is ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, iminodiacetic acid, 1,3-propanediaminetetraacetic acid, 1,4.
-Butanediaminetetraacetic acid, 1-methylpropanediaminetetraacetic acid, 2-methylpropanediaminetetraacetic acid, 2,2-
Dimethylpropanediaminetetraacetic acid, 1,2-dimethylethylenediaminetetraacetic acid, 1,2-dimethylpropanediaminetetraacetic acid, 1,3-dimethylpropanediaminetetraacetic acid, 1,2-propylenediaminetetraacetic acid, nitrilotriacetic acid, hydroxyethyl The method according to claim 1, which is a ferrous complex of at least one aminopolycarboxylic acid selected from the group consisting of iminodiacetic acid and ethylenediamine-N-hydroxyethyl-N, N ', N'triacetic acid.