JP4088076B2 - Method for producing alkali iodine salt - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an alkaline iodine salt.
[0002]
Iodine alkali salt is an important substance as a chemical raw material or a raw material for producing pharmaceuticals.
[0003]
[Prior art]
As a method for producing an alkali salt of iodine, for example, a structure described in, for example, Japanese Patent Publication No. 5-80410 is known. This Japanese Patent Publication No. 5-80410 discloses, for example, formic acid in the presence of an alkali. It is reduced using a reducing agent.
[0004]
In addition, as a method for producing raw material iodine, an oxidizing agent such as chlorine is introduced into an aqueous solution in which iodine ions are dissolved to convert iodine ions into free iodine, which is then expelled with air and absorbed in a reducing solution such as sodium bisulfite. Known are a blowing-out method, an activated carbon method in which free iodine is adsorbed and fixed on activated carbon, or an ion exchange resin method in which iodine ions and free iodine are adsorbed on an ion exchange resin.
[0005]
That is, the conventional method is a method in which an oxidizing agent is introduced into an aqueous solution in which iodine ions are dissolved, once isolated and purified as free iodine, and then reduced to obtain an alkali salt of iodine.
[0006]
Conventional methods for producing alkaline salts of iodine have many industrial problems, such as many steps, requiring secondary materials and processing of by-products.
[0007]
The object of the present invention is to provide a process for producing iodine alkali salts economically.
[0008]
[Means for Solving the Problems]
The present invention is represented by sodium iodide NaI, alkali B, which is either an ammonium salt or lithium, and X, which is either chlorine or bromine. Ammonium chloride, ammonium bromide and lithium chloride Is reacted with any one of water, alcohol and nitrile in which only one of the reaction products BI and NaX is dissolved according to the reaction formula: NaI + BX → BI + NaX. A method for producing an alkali iodine salt, wherein the sodium iodide NaI and the alkali salt BX are mixed with the sodium iodide NaI and the alkali salt BX in the solvent at a concentration of 5 wt% to 30 wt%. This is a method for producing an iodine alkali salt to be reacted.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a method for producing an iodine alkali salt of the present invention will be described.
[0010]
While stirring one of the raw materials, the other one is added as it is or as a solution dissolved in a solvent.
[0011]
Sodium iodide NaI as a raw material is an iodine alkaline salt aqueous solution separated by electrodialysis from an iodine absorbing solution obtained by hydrolyzing an iodine absorbing solution or organic iodine compound usually produced by a blowing-out method with an acid or alkali. Used as is or after purification .
[0012]
Alkaline salt BX having different halogen other than iodine which is the other raw material is represented by alkali B which is either ammonium salt or lithium and X which is chlorine or bromine. Either an ammonium salt bromide or lithium chloride . The halogen other than iodine is usually chlorine or bromine.
[0013]
The solvent may be a solvent in which one of the reaction products is dissolved and the other is not dissolved. Usually water, alcohols or nitriles such as methanol, ethanol, isopropanol , n-propanol, n-butanol, iso-butanol, tert-butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetonitrile, propionitrile or butyronitrile. Etc.
[0014]
Molar ratio of sodium iodide NaI and A alkali salt BX as a raw material is usually 1. In addition, the concentration in the reaction system is usually in the range of 5 to 30% by weight because the apparatus efficiency decreases when it is dilute.
[0015]
The reaction temperature of the sodium iodide NaI and A alkali salt BX is usually because it is under normal pressure, which is the boiling point of the solvent used at room temperature.
[0016]
The reaction time of sodium iodide NaI and A alkali salt BX is usually in the range of 0.5 to 24 hours.
[0017]
The reaction products are indicated as BI and NaX, and by filtering the reaction product solution , one of these BI and NaX can be easily separated as a crystal and the other of these BI and NaX as a solution.
[0018]
【Example】
Next, examples of the present invention will be described.
[0019]
Example 1
In a 300 ml three-necked flask equipped with a thermometer and a stirrer, 60 g of sodium iodide and 90 g of water were weighed and dissolved by stirring at room temperature, and then 43.8 g of tetramethylammonium chloride, which is a tetraalkylammonium chloride, was added.
[0020]
In this state, after aging reaction at room temperature for 2 hours, the reaction product was filtered, washed with 20 g of water, and then dried in vacuum to obtain 80.5 g of white crystals.
[0021]
The resulting crystal was analyzed by ion chromatography, was 98.2% pure iodide tetramethylammonium U beam, yield based on the charged chloride tetramethylammonium c arm was 98.3%.
[0022]
Example 2
In a 300 ml three-necked flask equipped with a thermometer and a stirrer, 17 g of lithium chloride and 200 g of isopropanol were weighed, heated to 80 ° C., dissolved by stirring, and then 60 g of sodium iodide was added.
[0023]
In this state, after aging reaction at 80 ° C. for 3 hours, the reaction product was filtered, washed with 50 g of isopropanol, the filtrate and the washing solution were combined and concentrated under reduced pressure, and then dried to obtain 53.1 g of white crystals. Got.
[0024]
When the obtained crystals were analyzed by ion chromatography, the purity of lithium iodide was 97.8%, and the yield based on the charged lithium chloride was 97.1%.
[0025]
Example 3
To thermometer and marked with stirrer 300ml three-necked flask, stirred dissolution and warmed to weighed tetra -n- propyl ammonium 53.5g and n- propanol 200g is tetraalkylammonium bromide to 95 ° C. 30 g of sodium iodide was added.
[0026]
In this state, after aging reaction at 95 ° C. for 8 hours, the reaction product was filtered, washed with 50 g of n-propanol, the filtrate and the washing solution were combined, concentrated under reduced pressure, and dried to obtain white crystals. 63.5 g was obtained.
[0027]
When the obtained crystals were analyzed by ion chromatography, the purity of tetra-n-propylammonium iodide was 96.4%, and the yield based on the charged tetra-n-propylammonium bromide was 97.7%. there were.
[0028]
Example 4
To a 300 ml three-necked flask equipped with a thermometer and a stirrer, 22.8 g of benzyltriethylammonium chloride and 140 g of acetone were weighed and dissolved by stirring at room temperature, and then 15 g of sodium iodide was added.
[0029]
In this state, the temperature was raised and the mixture was aged at 55 ° C. for 2 hours. The reaction product was filtered, washed with 50 g of acetone, the filtrate and washings were combined, concentrated under reduced pressure, and dried. 31.4 g of white crystals were obtained.
[0030]
When the obtained crystals were analyzed by ion chromatography, the purity of benzyltriethylammonium iodide was 97.4%, and the yield based on the charged benzyltriethylammonium chloride was 95.8%.
[0031]
Example 5
In a 500 ml three-necked flask equipped with a thermometer and a stirrer, 28.0 g of choline chloride and 300 g of ethanol were weighed and dissolved by stirring, and then 30 g of sodium iodide was added.
[0032]
In this state, the temperature was raised and the mixture was aged at 75 ° C. for 5 hours. The reaction product was filtered, washed with 50 g of ethanol, the filtrate and washings were combined, concentrated under reduced pressure, and dried. 46.4 g of white crystals were obtained.
[0033]
When the obtained crystals were analyzed by ion chromatography, the purity of choline iodide was 93.8% and the yield based on the charged choline chloride was 94.1%.
[0034]
【The invention's effect】
According to the present invention, obtained with sodium iodide NaI, and a alkali salt BX, it can produce iodine Motoa alkali salts in a simple manner, an efficient and A alkali salts of economically iodine without going through solid iodine be able to.

Claims (2)

Sodium iodide NaI,
An alkali salt B, which is either an ammonium salt or lithium, and an alkali salt BX, which is any one of an ammonium salt chloride, an ammonium salt bromide and a lithium chloride, and an alkali salt BX which is any one of chlorine and bromine. ,
Reaction formula: NaI + BX → BI + NaX
A method for producing an alkali alkali iodine which is reacted in any one of water, alcohol and nitrile in which only one of BI and NaX as reaction products is dissolved,
Iodine alkali salt characterized by reacting sodium iodide NaI and alkali salt BX in a state where the concentration of sodium iodide NaI and alkali salt BX in the solvent is 5 wt% to 30 wt%. Manufacturing method. The alkali salt BX is any one of tetraalkylammonium chloride, lithium chloride, tetraalkylammonium bromide, benzyltriethylammonium chloride, and choline chloride. The method for producing an alkali alkali iodine according to claim 1.