JPS62451A - Manufacture of disodium ethylenediaminetetraacetate and hydrate thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing ethylenediaminetetraacetic acid disodium salts and hydrates thereof.

Ethylenediaminetetraacetic acid (abbreviated as EDTA)
are most widely used as chelating and complexing agents. This is useful for the control of metal ions in various media and also for modifying, adjusting and directing reactions mediated by such controlled metal ions, such as EDTA and its soluble salts. is an important additive in laundry compositions and is used to inhibit unwanted calcium ions from forming soap agglomerates by chelation.

Preferred metal chelates of EDTA are also used in large quantities in the agricultural and pharmaceutical fields.

Disodium zinc EDTA chelate compounds are used in agriculture. Disodium calcium EDTA is used as a preservative in pharmaceutical compositions and to prevent calcium-depleting diuretics from entering the body.

Calcium chelating compounds of this type have also been administered directly as drugs for lead chelation in cases of acute and chronic lead poisoning and as drugs against heavy metal uptake.

Furthermore, chelates of iron, copper, and manganese have been used in agriculture, and also in the oxidation of nitrogen oxides.
The chelating action of EDTA, which has been used for reduction and even for the sweetening of sour natural gas, allows for the selective enrichment and isolation of valuable heavy metals such as uranium, plutonium, thorium, and rare earth elements. It is also used for.

The production of these EDTA salts was originally described in U.S. Patent No. 24078.
45, No. 2481519, and No. 2855428. The method described in the last patent document is the ED of the present application.
This is the basis of the TA production method, in which production proceeds via cyanomethylation in an acidic solution to retard the polymerization of HCN. This synthesis method via hydrolysis of nitrile primarily produces EDTA tetrasodium salt (EDTA.

Naa) is produced, which is then converted to EDTA free acid (E
DTA, AA). Until now, the desired salts have been produced by neutralizing this free acid. However, due to the limited solubility of EDTA and AA, the salt-forming reaction proceeds slowly and gives various products that require recrystallization and repurification.

Since the desired substance is required in large quantities, such purification steps are economically disadvantageous and reduce competitiveness.

Therefore, the purpose of the invention is to (In the formula, n is 1 or 2.

M is Na, K, Li, Rb, Zn, Ca,
means Fe, Mn or Cu, and one of M is Na, K.

A feature of the process of the present invention is to provide a process for the preparation of EDTA salts (when Li or Rh is meant, the other M can also mean H), and a feature of the process of the invention is to provide a process for preparing EDTA salts of the formula , under vacuum, in the presence of sufficient water to ensure ionization, a) formula % formula % (where Mel*Na" , Ke, Liet Taha Rbet
or b) with 1 mole or 2 moles of a compound of the formula % (meaning:

M is Li, Na, K, Rb, Ca, Mn,
Fe, Cu or Zn.

X is mixed with 1 mole of 0,0f (t?, means CO3, m and n are 1 or 2 independently of each other), dissipates the exothermic heat and the generated water vapor and finally the generated The goal is to collect the produced products.

X in the compound of formula (4) is 0 or 00 when m is 1
3, and when m is 2, X is OH.

The gist of the invention is to prepare a dry or wet cake of the commercially available disodium salt of ethylenediaminetetraacetic acid with the oxide, carbonate or hydroxide of component M in solid or wetting agent state, and hydrogen in the form of component M. and the resulting salt is collected.

Examples of commercially valuable salts produced by the method of the present invention and used in large quantities in the agricultural, pharmaceutical, laundry and mining fields are Na3-EDTA, Na4-EDTA, Na
2Mn-EDTA and Na2Cu-EDTA.

Examples of oxides, carbonates, and hydroxides of component M that can be used in the reaction include NaOH and Na2O.

ZnO, ZnCO3, Zn(OH)2. CuCO3,
Cub, Cab.

Ca(OH)2. CaCO3, MnO, MnCO3,
KOH, K2CO3°FeCO3, etc. Although sodium, zinc, calcium and manganese salts are currently produced commercially in large quantities, the process of the present invention allows for the production of lithium, potassium, rubidium, cadmium, rare earth metal (mixed metal) salts. Other salts can be made including heavy metal salts and uranium salts. iron, cobalt.

Salts of nickel can be produced practically in small quantities as catalysts or as intermediates for isolation steps in mining or laboratory work. The so-called "dry" mix reaction of the invention is also economical for such work. can be applied to

Since the reaction is essentially an ion-mediated reaction, the presence of water accelerates the reaction.

Since the Na2EDTA wetcake contains about 15% water, this is generally sufficient to initiate the reaction. However, some oxide and hydroxide reactants require water of hydration for ion formation, and in such cases it is useful to add more water to the reactor. Whether it is necessary to add water or not, use Na2 EDT
This can be determined by whether the combination of A and component M generates heat. However, from the point of view of manufacturing economy, it is not practically necessary to add water in excess of the theoretical amount. Water may be added in a stoichiometric amount or to such an extent that no exothermic reaction occurs.

Mixing of the Na2EDTA wet cake with component MOH or MX should be carried out in a vessel that ensures intimate mixing and contact of both solid reactants. A twin-drum mixer, conical mixer or similar device with rotation of the vessel or stirring with a built-in stirrer is sufficient.1 A heat source capable of raising the internal temperature of the vessel in order to initiate and proceed the reaction at an advantageous rate is sufficient. Preferably, the starting temperature should generally be above 15°C. However, it is not necessary to exceed this starting temperature since the exotherm and heat of hydration provide most of the heat required for the reaction.

Since the reaction involves an ionic reaction and requires some water, it is desirable to control the water content of the reaction mixture upon completion of the reaction and also during the reaction to provide a free-flowing final product. This can be easily accomplished by venting excess water vapor from the interior of the reactor via a vacuum line. The reaction starting temperature is 600 to 720°C since it rises to 100°C or more due to the exothermic reaction after the start.
Preferably, a vacuum of mm Hg is available.

Moisture control suppresses the formation of large crystals in the final product, and most of the final product is completely water-soluble. The formation of large crystals is undesirable because it detracts from the desired free-flowing properties of the final product.

As mentioned above, stirring in the reactor helps to accelerate the reaction as well as to control the particle size of the final product, producing a free-flowing powder by careful stirring and adjusting the stirring speed in the case of high moisture in the latter stages of the reaction. Product availability is guaranteed, proper stirring ensures heat transfer for water vapor removal, and crystallization at low temperatures and crystal growth beyond the desired size are prevented.

Adequate agitation also helps to keep the products and reactants below their melting points; as melting occurs within the mixture, the particle size becomes larger than desired.

Completion of the reaction and removal of water vapor is achieved in a temperature range of 40 to 100°C, preferably 46 to 95°C.

Examples of commercially available reactors useful for "dry" or solid state mixing and reactions according to the present invention include:

Day Mark II: This is a jacketed conical vessel containing one or more screw-type stirrers that rotate in parallel close to the conical inner wall of the vessel, and has a pressure of 720 mm Hg. evacuated to a vacuum source.

Patterson-Kelly
l y) Jacketed mixer: This has a hollow support shaft equipped with pressure intensifier baffles and connected to a vacuum source.

Stokes rotary vacuum dryer.

Using these or similar devices, the method of the invention can be carried out economically even in large-scale production.

The present invention will be further explained below with reference to Examples. Note that the percentages are weight percentages.

101 Conical mixer with jacket and built-in Niscrew stirrer (
Day Mark II) with a certified purity of 93% Na.
2EDTA wet cake 35. Loaded with IKg. The vessel was heated through the jacket oil to raise the contents temperature to 15°C and zinc oxide (99%) to 7.8K.
The reaction mixture was heated to about 40° C. in a zero exothermic reaction. The reaction mixture was sprayed with 1.35 Kg of water. After sealing this container, approximately 635 to 71
The pressure was reduced to 1 mmHG vacuum. It was further heated to 82-85°C with hot oil in the jacket.

Vacuum pressure was maintained during heating. After this, heating was discontinued.

The batch temperature was reduced to about 65°C. Vacuum evaporation was continued for an additional hour before the product was discharged. Na2・Zn・ED with purity of 85-86% as a free-flowing powder product
45 kg of TA was obtained.

The operation was carried out according to Shirankoe Example 1. However, this time, zinc carbonate (ZnCO3) 11.2K was used instead of zinc oxide.
g was used. However, Na2・Z with a purity of 85-86%
45 kg of n-EDTA was obtained.

Example 1: Naz EDTA (93%) 39-9Kg
was loaded into the same mixing device, followed by NaOH7 lake (
After the exothermic reaction was completed and heated to 65.5°C, vacuum drying and stirring were carried out until the free-flowing powder could be discharged (approximately 2 hours). Continued. However, N with a purity of 87%
45 K g of a3EDTA was obtained.

39.9 Kg of 1A Na2 EDTA wet cake was loaded into the same mixing device (DayMark II) as in Example 1. 8.7Kg of 50% NaOH solution for 30 minutes
The reaction was carried out by uniformly spraying under vacuum (711 mmHg). After the exothermic reaction was completed and heated to 65.5 °C, vacuum drying and stirring were carried out until a free-flowing powder could be discharged ( (approximately 2 hours) continued. Thus, 45 K g of Na 3EDTA with a purity of 87% was obtained.

1 shift 1 93% pure Na2EDTA wet cake 75.6
Kg in a twin vacuum mixer (Patterson above)
Kel 1 y) was loaded. Add Na0H to this
(50%) Solution 18, OKg was sprayed under 711 mmHg vacuum. A zero exothermic reaction brought the temperature of the reaction mixture to 37.
The temperature rose from 8 to 46°C. Heating and vacuum drying were continued for an additional hour. Therefore, Na5EDT as a product
92.7 kg of A was obtained.

Branch Team J The same operation as in Example 4 was carried out. However, this time NaO
50% solution of Na2CO3 instead of 50% solution of H23
．． 6 Kg was used and this was sprayed into the reactor under vacuum (711 mmHg). After completion of the zero exothermic reaction, the reaction mixture was heated to vacuum drying and discharged. 85%Na5ED
TA was obtained.

The same apparatus as in Example 1 was loaded with 43.5 kg of Na2 EDTA and 18 kg of a 50% solution of NaOH was sprayed onto it under vacuum (711 mmHg). After the exothermic reaction was completed, the reaction mixture was Heated for 1 hour. Thus, 45 K g of cDNA aa ED TA with a purity of 91% was obtained.

11 Rotary vacuum dryer with double spiral stirrer (Stok
es-Pennwalt) with steam at 172° 25 kPa in the jacket and stirrer shaft, then
1620Kg of Na2EDTA wetcake was charged and stirred to break up any lumps. Then NaOH ball 167.4
Kg (11% excess) was added.

9 kg of water was poured onto the stirrer to wash off the material. After stirring for 30 minutes with the lid open, add Na5E.
It was dried until the DTA content was 90.2%. The pH of a 10% solution of this product was 8.2.0 color was 15APHA
Met.

After discharging the previous batch, 1620 kg of the Na2EDTA processed cake was loaded into the rotary vacuum dryer of Example 8. After stirring and crushing the lumps, 72.3 kg of NaOH balls
Then, 54 kg of water was loaded and stirred with the lid open.

92% using 172.25kPa steam in the jacket
The product was discharged after drying to purity Na5EDTA. The pH of a 10% solution of this product was 8.2-8.3.

Color was 15-25 APHA.

1350 kg of Na2 EDTA wet cake was loaded into a rotary vacuum dryer which had been thoroughly cleaned. After stirring and crushing the lumps, 45 kg of sodium sulfate and 264.6 kg of NaOH balls were added.
and stirred with the lid open. The batch was vacuum dried to 92% pure Na5EDTA and discharged. The powder was sieved and the mass was ground to a uniform size.

1350 kg of Na2EDTA processed cake was loaded into a cleaned rotary vacuum dryer. Stir to break up the lumps, Cu0
Loaded with 238.5Kg. Next, 108 kg of water was loaded. The reaction mixture was heated to about 90-100° C. with 172.25 kPa steam in the jacket and stirrer. After stirring for 2 hours at a temperature of about 90° C., the presence of excess Na2 EDTA was tested. To reduce free Na2EDTA to low levels, 5Kg of Oa 5H2058 and NaHCO33 were added to the reaction mixture.
9. Add IKg and stir for 1 hour. It is then vacuum-dried with steam in a jacket and a stirrer until the moisture content is reduced to about 10%. After drying, 900Kg of Na2-Cu.

EDTA was obtained.

Load 1350 kg of Na2 EDTA wet cake and 217 kg of zinc oxide into a cleaned rotary vacuum dryer.
108 liters of water was added to give a moisture content of 30-35% in the reaction mixture, which was stirred for an hour and heated to about 90-95°C with steam in the jacket and shaft. 2
After reacting for an hour, the presence of free Na2EDTA was tested. After adjusting with 4.5 kg of NaHcO3, it was vacuum dried. However, Na2・Zn・E
90.75 kg of DTA was obtained. The product was sieved and ground to a uniformly sized powder.

After discharging the previous batch of support units, first load 900Kg of NazEDTA wet cake, then Zn0246K.
g was loaded. After mixing for 15 to 30 minutes, 108
Spray with a little water and heat the dryer to 80-95°C. After stirring for 2 hours, free Na2EDT
The presence or absence of A was tested. Zn5O4.7H to reduce excess Na2EDTA and adjust pH
204.6 Kg and 6.3 Kg of NaHCO were added. After conditioning, the batch was vacuum dried to 63% (EDTA basis) and discharged. However, Na2・Zn・ED
725.8 kg of TA was obtained.

Actual JL Example 14 1350 kg of Na2EDTA in a cleaned rotary vacuum dryer
is charged and stirred, and fine powder M n 0202 K is added to this.
Then, I added 108 kg of real fishing. The mixture was heated to 90-95° C. with stirring until the reaction mixture became a flowable thin slurry. After stirring at 90-95° C. for 2 hours, the presence of free NazEDTA was tested. (Balance adjustment was performed as follows: free Na2
When the EDTA concentration is too high, M n S Oa・H
Adjust using 2O and NaHCO3. The excess of MnO is adjusted using Na2EDTA. product pH
Adjustment using NaHCO3 or diluted H2SO4
It was done using. ) After making the necessary adjustments (N
a2EDTA wet cake 55.3Kg, Mn5O
a・H2O7,2Kg and NaHCO321, IKg
), dry this batch and obtain the product 7
29Kg was discharged and ground to a uniform size powder.

Claims (1)

[Claims] 1. Formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, n is 1 or 2, M is Na, K, Li, Rb , Zn, Ca, Fe, Mn or Cu, and if one of the M's stands for Na, K, Li or Rb, the other M may also stand for H). In the method of preparation, one mole of a wet cake of EDTA salt of the formula ▲ is prepared under vacuum in the presence of sufficient water to ensure ionization, a) with the formula M^■OH^■ (wherein M^■ means Na^■, K^■, Li^■ or Rb^■) or b) mixed with 1 mol or 2 mol of a compound of formula 3-nM^n^ ■mX^3^-^■ (In the formula, M means Li, Na, K, Rb, Ca, Mn, Fe, Cu or Zn, X means O, OH or CO_3, and m and n are independent of each other. 1 or 2), dissipating the exothermic heat and the water vapor generated and finally collecting the product formed. 2. Process according to claim 1, characterized in that Na_3.EDTA is prepared by mixing the wet cake of Na_2.EDTA with 1 mole of NaOH as compound MOH under vacuum. 3. Process according to claim 1, characterized in that Na_4.EDTA is prepared by mixing the wet cake of Na_2.EDTA with 2 moles of NaOH as compound MOH under vacuum. 4. Process according to claim 1, characterized in that Na_2.Zn.EDTA is prepared by mixing the wet cake of Na_2.EDTA with 1 mole of ZnO as compound MX under vacuum. 5. Process according to claim 1, characterized in that Na_4.EDTA is prepared by mixing the wet cake of Na_2.EDTA with 1 mole of Na_2CO_3 as compound MX under vacuum. 6. Process according to claim 1, characterized in that Na_2.Mn.EDTA is prepared by mixing the wet cake of Na_2.EDTA with 1 mole of MnO as compound Mx under vacuum. 7. The wet cake of Na_2·EDTA is mixed with 1 mole of Cu(OH)_2 as compound MX under vacuum to produce Na_2·Cu·EDTA according to claim 1. the method of. 8. The method according to claim 2 or 3, characterized in that NaOH is added as caustic flakes or pellets. 9. The method according to claim 2 or 3, characterized in that NaOH is added as a 50% aqueous solution of NaOH. 10. The method according to claim 2 or 3, characterized in that Na_2CO_3 is used instead of NaOH. 11.40 to ensure completion of the reaction and removal of water vapor
A method according to claim 1, characterized in that heating is carried out to a temperature between 100°C and 100°C.