JP6267523B2 - Vinyl sulfonic acid aqueous solution and production method thereof, and purified vinyl sulfonic acid and production method thereof - Google Patents

Description

  The present invention relates to an aqueous vinyl sulfonic acid solution and a production method thereof, and a purified vinyl sulfonic acid product and a production method thereof.

  Vinyl sulfonic acid has attracted a great deal of attention as a monomer constituting functional polymers and conductive materials. However, the vinyl sulfonic acid concentration in the commercially available vinyl sulfonic acid product is 75% by mass or less. When such a vinyl sulfonic acid is used, there exists a problem that superposition | polymerization does not fully advance. Under such a background, Patent Document 1 describes a method of producing an electrolyte membrane using 98% pure vinylsulfonic acid.

International Publication No. 2006/059582 Pamphlet

  However, there are various problems in the process of producing a high concentration vinyl sulfonic acid. In order to obtain high-concentration vinyl sulfonic acid, the raw material containing vinyl sulfonic acid metal salt (vinyl sulfonic acid metal salt aqueous solution) is used to demetalize vinyl sulfonic acid metal salt contained in the raw material. Then, an ion exchange treatment step for removing inorganic impurities, a dehydration step for removing water contained in the raw material, and a thin film distillation step for removing other impurities such as organic impurities are performed.

  In the ion exchange treatment step, a crude raw material containing a vinyl sulfonic acid metal salt is diluted with water to a predetermined concentration, and the diluted crude raw material is passed through an ion exchange resin tower to demetalize the vinyl sulfonic acid metal salt. This is a step of removing inorganic impurities. Through this ion exchange treatment step, the water concentration in the raw material after the ion exchange treatment step becomes high, so that the subsequent dehydration step takes a long time and the used ion exchange resin is regenerated. There is a problem that a burden arises.

  The dehydration step is a step of removing water by reducing the pressure and / or heating the crude material after the ion exchange treatment step. However, since the crude raw material containing vinyl sulfonic acid after the conventional ion exchange treatment process has a high moisture concentration and contains a lot of organic impurities, the vinyl sulfonic acid is polymerized or deteriorated by heat during the dehydration process, particularly in the heating operation. Or the organic impurities are thermally decomposed, or the organic impurities are increased in viscosity and the subsequent thin film distillation process cannot be performed.

  The final thin film distillation step is a step of thin-film distillation of the crude material after the dehydration step to remove other impurities such as organic impurities. However, when crude raw materials containing vinyl sulfonic acid after the conventional ion exchange treatment process are used, removal of impurities such as sulfuric acid is insufficient in the thin film distillation process, and the resulting vinyl sulfonic acid purified product is stored. There is a problem that stability is inferior.

  The present invention has been made in view of the above-mentioned problems, a vinyl sulfonic acid aqueous solution that can shorten the heating operation time in the dehydration step, and can suppress the generation of a viscous material, a method for producing the same, and storage stability. An object of the present invention is to provide a purified vinyl-based sulfonic acid having excellent properties and a method for producing the same.

That is, the present invention is as follows.
[1]
7 to 35% by mass of a sulfonic acid having a vinyl group;
0.0030 to 2.0% by mass of an ether compound having a sulfonic acid group,
Vinyl-based sulfonic acid aqueous solution.
[2]
The vinyl-based sulfonic acid aqueous solution according to [1], further including 0.030 to 1.0% by mass of sulfuric acid.
[3]
The vinyl sulfonic acid aqueous solution according to [1] or [2] above, wherein the sulfonic acid having a vinyl group has a molecular weight of 100 to 150.
[4]
The vinyl sulfonic acid aqueous solution according to any one of [1] to [3], wherein the sulfonic acid having a vinyl group includes vinyl sulfonic acid or allyl sulfonic acid.
[5]
A purified vinyl sulfonic acid product comprising 95 to 99.5% by mass of a sulfonic acid having a vinyl group and 0.050 to 0.23% by mass of sulfuric acid.
[6]
The vinyl sulfonic acid purified product according to [5], wherein the sulfonic acid having a vinyl group has a molecular weight of 100 to 150.
[7]
The vinyl sulfonic acid purified product according to [5] or [6] above, wherein the sulfonic acid having a vinyl group includes vinyl sulfonic acid.
[8]
An electrodialysis step of supplying an aqueous solution containing a vinyl group-containing sulfonic acid metal salt to a raw material chamber of an electrodialyzer and performing electrodialysis to obtain a vinyl-based sulfonic acid aqueous solution;
In the electrodialysis apparatus, an anion exchange membrane and a cation exchange membrane are disposed between two anode membranes provided between an anode and a cathode so that the anion exchange membrane side faces the anode side. The acid chamber partitioned by the bipolar membrane and the anion exchange membrane, the raw material chamber partitioned by the anion exchange membrane and the cation exchange membrane, and partitioned by the cation exchange membrane and the bipolar membrane. Has an alkaline chamber,
The vinyl-based sulfonic acid aqueous solution includes 7 to 35% by mass of a sulfonic acid having a vinyl group and 0.0030 to 2.0% by mass of an ether compound having a sulfonic acid group.
A method for producing an aqueous vinyl sulfonic acid solution.
[9]
The method for producing an aqueous vinyl-based sulfonic acid solution according to [8] above, wherein the sulfonic acid metal salt having a vinyl group includes sodium vinyl sulfonate or sodium allyl sulfonate.
[10]
The bipolar membrane includes a cation exchanger containing a sulfonic acid of a styrene-divinylbenzene copolymer and an anion exchanger containing a quaternary ammonium compound of a polystyrene polymer, [8] or [9] The manufacturing method of the vinyl-type sulfonic acid aqueous solution of any one of these.
[11]
The said anion exchange membrane is a manufacturing method of the vinyl-type sulfonic acid aqueous solution of any one of the preceding clauses [8]-[10] containing the quaternary ammonium compound of a styrene divinylbenzene type polymer.
[12]
The method for producing an aqueous vinyl sulfonic acid solution according to any one of [8] to [11] above, wherein the cation exchange membrane contains a sulfonic acid of a styrene-divinylbenzene copolymer.
[13]
A dehydration step of removing water from the vinyl sulfonic acid aqueous solution obtained by the method for producing a vinyl sulfonic acid aqueous solution according to any one of [8] to [12] to obtain a vinyl sulfonic acid composition; A thin film distillation step of thin-film distillation of the vinyl-based sulfonic acid composition to obtain a purified vinyl-based sulfonic acid product, and a method for producing a purified vinyl-based sulfonic acid product.

  ADVANTAGE OF THE INVENTION According to this invention, the vinyl sulfonic acid aqueous solution which can shorten heating operation time in a spin-drying | dehydration process, can suppress generation | occurrence | production of a viscous material, its manufacturing method, and the vinyl sulfonic acid purified product excellent in storage stability And a manufacturing method thereof.

It is a chart which shows the manufacturing method of the vinyl sulfonic acid refinement | purification thing of this embodiment. It is a chart which shows the preparation method of the conventional high concentration vinylic sulfonic acid. It is the schematic of an electrodialysis apparatus. It is a schematic diagram which shows an example of a thin film distillation apparatus.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. However, the present invention is not limited to this, and various modifications can be made without departing from the gist thereof. Is possible.

[Vinyl sulfonic acid aqueous solution]
The vinyl sulfonic acid aqueous solution of this embodiment contains 7.0 to 35% by mass of a sulfonic acid having a vinyl group and 0.0030 to 2.0% by mass of an ether compound having a sulfonic acid group. The aqueous vinyl sulfonic acid solution of the present embodiment becomes a high-quality purified vinyl sulfonic acid product through a dehydration step and a thin film distillation step described later.

[Sulphonic acid having a vinyl group]
The content of the sulfonic acid having a vinyl group contained in the aqueous vinyl sulfonic acid solution is 7.0 to 35% by mass, preferably 10 to 35% by mass, based on the total amount of the aqueous vinyl sulfonic acid solution. More preferably, it is 10-25 mass%. In the conventional method using an ion exchange treatment step, since it is necessary to dilute an aqueous solution containing a sulfonic acid metal salt having a vinyl group, a vinyl sulfone containing 7.0% by mass or more of a sulfonic acid having a vinyl group. An acid aqueous solution cannot be obtained. If the content of the sulfonic acid having a vinyl group is less than 7.0% by mass, that is, if the content of water is high, the time required for the dehydration process will be prolonged and the production cost will be increased. Polymerizes or deteriorates thermally. In this respect, the vinyl-based sulfonic acid aqueous solution according to the present embodiment contains 7.0% by mass or more of the sulfonic acid having a vinyl group, so that the time required for the dehydration step can be shortened, and the sulfonic acid having a vinyl group is polymerized or Thermal deterioration can be suppressed. Moreover, according to the electrodialysis process described later, it is possible to efficiently obtain a vinyl sulfonic acid aqueous solution containing 7% by mass or more of a sulfonic acid having a vinyl group. In addition, content of the sulfonic acid which has a vinyl group can be measured by the method as described in an Example.

  The sulfonic acid having a vinyl group is not particularly limited, but vinyl sulfonic acid and allyl sulfonic acid are preferable. Vinyl sulfonic acid and allyl sulfonic acid tend to be particularly liable to cause polymerization or thermal deterioration by heating operation in the dehydration step. In this respect, since the content of the sulfonic acid having a vinyl group in the aqueous vinyl sulfonic acid solution is 7.0% by mass or more, the heating time in the dehydration step can be shortened, and thus the polymerization of the sulfonic acid having a vinyl group is achieved. Or thermal degradation can be suppressed. Therefore, the present invention is particularly useful when vinyl sulfonic acid and allyl sulfonic acid are used as the sulfonic acid having a vinyl group. In addition, the sulfonic acid which has a vinyl group may be used individually by 1 type, or may use 2 or more types together.

  The molecular weight of the sulfonic acid having a vinyl group is preferably 100 to 150, more preferably 100 to 130. When the molecular weight of the sulfonic acid having a vinyl group is within the above range, the vinyl sulfonic acid aqueous solution of the present embodiment tends to be obtained more efficiently.

[Ether compound having a sulfonic acid group]
The content of the ether compound having a sulfonic acid group contained in the aqueous vinyl sulfonic acid solution is 0.0030 to 2.0% by mass, preferably 0.0030 to 1%, based on the total amount of the aqueous vinyl sulfonic acid solution. 0.5% by mass, and more preferably 0.0030 to 1.0% by mass. In the method using the conventional ion exchange treatment step, only metal removal can be performed, and an ether compound having a sulfonic acid group cannot be removed. However, when the ether compound having a sulfonic acid group is more than 2.0% by mass, a viscous material is generated by the heating operation in the dehydration step, and the viscous material tends to increase as the heating operation time in the dehydration step increases. is there. When such a viscous material is generated, there arises a problem that the dehydration rate is limited in the dehydration process, and sufficient dehydration cannot be performed, and that the process cannot be performed in the thin film distillation process. On the other hand, in the vinyl sulfonic acid aqueous solution of the present embodiment, the content of the ether compound having a sulfonic acid group is 2.0% by mass or less, thereby suppressing the formation of a viscous material and appropriately performing a dehydration step and The thin film distillation process can be advanced. The content of the ether compound having a sulfonic acid group is appropriately selected from the anion exchange membrane used in the electrodialysis step, which will be described later, the amount of electricity, the energization time, etc. This can be reduced. In addition, content of the ether compound which has a sulfonic acid group can be measured by the method as described in an Example.

Although it does not specifically limit as an ether compound which has a sulfonic acid group, For example, the compound represented by following formula (1) is mentioned. In particular, in the electrodialysis step described later, it is preferable to remove an ether compound having two or more sulfonic acid groups.
X- (R ¹ O) _n R ¹ -X (1)
(In Formula (1), each R ¹ independently represents a methylene, ethylene, propylene, or butylene group, each X independently represents a sulfonic acid group, a sulfonate group, or a hydroxyl group, and n is 1 to 10 integers.)

[Sulfuric acid]
The vinyl sulfonic acid aqueous solution of the present embodiment may contain sulfuric acid. The content of sulfuric acid is preferably 0.030 to 1.0 mass%, more preferably 0.030 to 0.50 mass%, still more preferably 0, based on the total amount of the vinyl-based sulfonic acid aqueous solution. 0.030 to 0.40 mass%. When the content of sulfuric acid is 1.0% by mass or less, the storage stability of the purified vinyl sulfonic acid product obtained through the dehydration step and the thin film distillation step tends to be further improved. In addition, content of a sulfuric acid can be measured by the method as described in an Example. Further, the content of sulfuric acid tends to decrease as the sulfate group contained in the metal salt decreases.

[Saturated aliphatic hydrocarbon having hydroxyl group and sulfonic acid group]
The vinyl sulfonic acid aqueous solution of this embodiment may contain a saturated aliphatic hydrocarbon having a hydroxyl group and a sulfonic acid group. Although it does not specifically limit as a saturated aliphatic hydrocarbon which has a hydroxyl group and a sulfonic acid group, For example, isethionic acid etc. are mentioned. The content of the saturated aliphatic hydrocarbon having a hydroxyl group and a sulfonic acid group is preferably 0.10 to 5.0 mass%, more preferably 0.10 to the total amount of the vinyl sulfonic acid aqueous solution. It is 3.0 mass%, More preferably, it is 0.10-2.0 mass%. When the content of the saturated aliphatic hydrocarbon having a hydroxyl group and a sulfonic acid group is within the above range, the dehydration efficiency in the dehydration step and the purification efficiency in the thin film distillation step tend to be further improved. In addition, content of the saturated aliphatic hydrocarbon which has a hydroxyl group and a sulfonic acid group can be measured by the method as described in an Example.

  A saturated aliphatic hydrocarbon having a hydroxyl group and a sulfonic acid group is a kind of organic impurity, and can cause a dehydration reaction in the subsequent dehydration step and thin film distillation step. Since water to be removed in the dehydration step is generated by the following dehydration reaction, the upper limit of the content of the saturated aliphatic hydrocarbon having a hydroxyl group and a sulfonic acid group is preferably 5.0% by mass.

〔water〕
The water content in the aqueous vinyl sulfonic acid solution of the present embodiment is preferably 50 to 90 mass%, more preferably 60 to 80 mass%, based on the total amount of the aqueous vinyl sulfonic acid solution. When the water content is within the above range, the efficiency in the dehydration process tends to be further improved. In addition, water content can be measured by the method as described in an Example.

[Metal impurities]
The aqueous vinyl sulfonic acid solution of the present embodiment may contain a small amount of metal impurities. Specifically, the content of at least one metal selected from the group consisting of alkali metals such as sodium, alkaline earth metals such as calcium, and transition metals such as iron, chromium, or nickel is preferably 0 to 1000 ppm, more preferably 0 to 500 ppm. When the metal content is 1000 ppm or less, the metal salt tends to be prevented from precipitating in the dehydration step. In addition, content of a metal impurity can be measured by the method as described in an Example. Moreover, content of a metal impurity is controllable by adjusting the conditions of the electrodialysis process mentioned later.

[Purified vinyl sulfonic acid]
The purified vinyl sulfonic acid of this embodiment contains 95 to 99.5% by mass of sulfonic acid having a vinyl group and 0.050 to 0.23% by mass of sulfuric acid. The purified vinyl-based sulfonic acid of the present embodiment is excellent in storage stability and high quality.

[Sulphonic acid having a vinyl group]
The content of the sulfonic acid having a vinyl group contained in the purified vinyl sulfonic acid product is 95 to 99.5% by mass, preferably 97 to 99.5% by mass, based on the total amount of the purified vinyl sulfonic acid product. %, More preferably 98 to 99.5% by mass. Storage stability improves more because content of the sulfonic acid which has a vinyl group exists in the said range. In addition, content of the sulfonic acid which has a vinyl group can be measured by the method as described in an Example.

  The sulfonic acid having a vinyl group is not particularly limited, but vinyl sulfonic acid and allyl sulfonic acid are preferable. Vinyl sulfonic acid and allyl sulfonic acid are particularly prone to deterioration. In products containing 95 to 99.5% by mass of a sulfonic acid having a vinyl group produced through a conventional ion exchange treatment process, there is a limit to the amount of sulfuric acid that can be removed. The storage stability of a sulfonic acid having a vinyl group is impaired. On the other hand, since the content of sulfuric acid in the purified vinyl-based sulfonic acid according to the present embodiment is 0.23% by mass or less, the storage stability can be further improved. Therefore, the present invention is particularly useful when vinyl sulfonic acid and allyl sulfonic acid are used as the sulfonic acid having a vinyl group. In addition, the sulfonic acid which has a vinyl group may be used individually by 1 type, or may use 2 or more types together.

  The molecular weight of the sulfonic acid having a vinyl group is preferably 100 to 150, more preferably 100 to 130. When the molecular weight of the sulfonic acid having a vinyl group is within the above range, the purified vinyl sulfonic acid of the present embodiment can be obtained more efficiently.

[Sulfuric acid]
The content of sulfuric acid contained in the purified vinyl sulfonic acid product is 0.050 to 0.23% by mass, preferably 0.050 to 0.10% by mass, based on the total amount of the purified vinyl sulfonic acid product. It is. When the content of sulfuric acid is more than 0.23% by mass, the storage stability of the vinyl-based sulfonic acid purified product solution may be colored over time, or the sulfonic acid having a vinyl group may be decomposed. . Conventionally, it has been considered that the content of sulfuric acid in a purified vinyl sulfonic acid product is due to the metal sulfate in the aqueous vinyl sulfonate metal salt solution used as a raw material. However, when the present inventors diligently studied to obtain a vinyl sulfonic acid purified product having high storage stability, sulfuric acid decomposes the sulfonic acid group of the ether compound having a sulfonic acid group in the dehydration step and the thin film distillation step. It turns out that it produces | generates by doing. That is, even when the sulfuric acid concentration in the aqueous vinyl sulfonic acid solution is low, there is a problem that the sulfuric acid concentration in the purified vinyl sulfonic acid product increases when an ether compound having a sulfonic acid group is present. I understood that. In the vinyl sulfonic acid aqueous solution obtained by the conventional ion exchange treatment step, it is difficult to reduce the content of the ether compound having a sulfonic acid group as described above, so the sulfuric acid concentration in the dehydration step and the thin-film distillation step The rise problem cannot be solved. On the other hand, since the content of the ether compound having a sulfonic acid group can be reduced in the electrodialysis process described later, the problem of an increase in sulfuric acid concentration in the dehydration process and the thin film distillation process can be solved. In addition, the sulfuric acid concentration in the purified vinyl sulfonic acid product can be controlled to 0.23 mass% or less. In addition, content of a sulfuric acid can be measured by the method as described in an Example.

〔water〕
The purified vinyl-based sulfonic acid of this embodiment may contain water. The content of water is preferably 0.20 to 2.0% by mass, more preferably 0.20 to 1.0% by mass, and still more preferably based on the total amount of the purified vinyl sulfonic acid product. It is 0.20 to 0.50 mass%. When the water content is within the above range, the storage stability tends to be further improved. In addition, water content can be measured by the method as described in an Example.

[Metal impurities]
The purified vinyl-based sulfonic acid of this embodiment may contain a small amount of metal impurities. Specifically, the total content of metals selected from the group consisting of alkali metals such as sodium, alkaline earth metals such as calcium, and transition metals such as iron, chromium, or nickel is preferably 0 to 1 ppm. Yes, more preferably 0 to 500 ppb, and still more preferably 0 to 300 ppb. When the metal content is 1 ppm or less, it tends to satisfy customer demands in various applications. For example, when vinyl sulfonic acid is used as a monomer constituting a functional polymer or a conductive material, the metal content is preferably 1 ppm or less because the larger the amount of metal impurities, the less favorable the material performance.
In addition, content of a metal impurity can be measured by the method as described in an Example. Moreover, content of a metal impurity is controllable by adjusting the conditions of the thin film distillation process mentioned later.

  The vinyl-based sulfonic acid purified product of the present embodiment has high storage stability and high quality, and is suitably used for functional polymers such as resist materials and electrolyte membranes and monomers constituting conductive polymers. be able to.

[Method for producing vinyl sulfonic acid aqueous solution]
The method for producing a vinyl sulfonic acid aqueous solution of the present embodiment includes supplying an aqueous solution containing a sulfonic acid metal salt having a vinyl group to a raw material chamber of an electrodialyzer and performing electrodialysis to obtain a vinyl sulfonic acid aqueous solution. The electrodialysis apparatus comprises an anion exchange membrane between two anode membranes provided between the anode and the cathode so that the anion exchange membrane side faces the anode side, and a cation By arranging an exchange membrane, an acid chamber partitioned by the bipolar membrane and the anion exchange membrane, the raw material chamber partitioned by the anion exchange membrane and the cation exchange membrane, and the cation exchange membrane An alkaline chamber partitioned by the bipolar membrane, and the vinyl sulfonic acid aqueous solution is 7.0 to 35% by mass of a sulfonic acid group having a vinyl group and an ether having a sulfonic acid group. Comprising a compound from 0.0030 to 2.0 wt%, a.

  FIG. 2 shows a conventional method for producing a vinyl sulfonic acid. In the conventional method for producing vinyl sulfonic acid, before the concentration is increased, the raw material containing the vinyl sulfonic acid metal salt is once diluted with water to a predetermined concentration (10% by mass or less), and the diluted vinyl sulfone is obtained. A crude material containing an acid metal salt is passed through an ion exchange resin tower to demetalize the vinyl sulfonic acid metal salt, and an ion exchange treatment step is performed to remove inorganic impurities. However, in the ion exchange treatment step, the raw material is once diluted with water to a concentration that allows the raw material to pass through the ion exchange resin, and a considerable amount of eluate (boost washing water) is further flowed in addition to the raw material. Therefore, the vinyl sulfonic acid concentration of the solution obtained after the ion exchange treatment step is reduced to about 2% by mass. In addition, in the ion exchange treatment step, the ether compound having a sulfonic acid group is not removed because it hardly interacts with the ion exchange resin, like the vinyl sulfonic acid. In addition, there is a problem that a work load such as recycling of the used ion exchange resin occurs.

  If such a low-concentration vinyl sulfonic acid solution is to be dehydrated, the cost associated with the dehydration step increases or the time required for the dehydration step increases. In the dehydration process, the vinyl sulfonic acid solution is heated from the viewpoint of efficiently removing water, but this heating takes a long time, so that the vinyl sulfonic acid is polymerized or thermally deteriorated, and the organic impurities are thermally decomposed. Or the organic impurities such as the organic compounds such as ether compounds having a sulfonic acid group are thermally decomposed to increase the amount of sulfuric acid.

  Further, a thin film distillation process is performed to remove other impurities such as organic impurities. However, in the case of using a raw material containing vinyl sulfonic acid after the conventional ion exchange treatment step, removal of impurities such as sulfuric acid is insufficient in the thin film distillation step, and the obtained vinyl sulfonic acid purified product There is also a problem that storage stability is poor.

  In FIG. 1, the manufacturing method of the vinyl-type sulfonic acid aqueous solution of this embodiment is shown. In contrast to the conventional vinyl sulfonic acid production method, the vinyl sulfonic acid aqueous solution production method of the present embodiment is 7.0 to 35% by mass by adopting an electrodialysis step instead of the ion exchange treatment step. A vinyl sulfonic acid aqueous solution containing a sulfonic acid having a high concentration of vinyl groups can be obtained. Therefore, the above problem associated with an increase in the time required for the dehydration process can be avoided. Moreover, the amount of organic impurities such as an ether compound having a sulfonic acid group can also be reduced. In addition, work burdens such as regenerating the ion exchange resin become unnecessary. Hereinafter, the electrodialysis process will be described in detail.

[Electrodialysis process]
The electrodialysis step is a step in which an aqueous solution containing a sulfonic acid metal salt having a vinyl group is supplied to a raw material chamber of an electrodialysis apparatus and electrodialyzed to obtain a vinyl sulfonic acid aqueous solution.

  FIG. 3 shows a schematic diagram of the electrodialysis apparatus. The electrodialysis apparatus is arranged between an anode and a cathode by placing an anion exchange membrane and a cation exchange membrane between two bipolar membranes provided so that the anion exchange membrane side faces the anode side, It has an acid chamber partitioned by a bipolar membrane and an anion exchange membrane, a raw material chamber partitioned by an anion exchange membrane and a cation exchange membrane, and an alkali chamber partitioned by a cation exchange membrane and a bipolar membrane.

(Bipolar membrane)
The bipolar membrane has a structure in which a cation exchange membrane and an anion exchange membrane are bonded together. By supplying electricity to the electrodialyzer, H + can be introduced into the acid chamber through the bipolar membrane. Moreover, OH- can be introduced into the alkali chamber. Examples of the bipolar membrane include those containing a cation exchanger containing a sulfonic acid of a styrene-divinylbenzene copolymer and an anion exchanger containing a quaternary ammonium compound of a polystyrene polymer. By using such a bipolar membrane, the demetallation efficiency of the sulfonic acid metal salt having a vinyl group, the yield of the sulfonic acid having a vinyl group, the selectivity, and the inorganic impurity removal efficiency tend to be further improved.

(Anion exchange membrane)
By passing electricity through the electrodialyzer, the sulfonic acid having a vinyl group can be moved from the raw material chamber to the acid chamber via the anion exchange membrane. Examples of the anion exchange membrane include those containing a quaternary ammonium compound of a styrene divinylbenzene polymer. Among them, those having the following structures (a) to (c) are more preferable, and those having the following structure (a) are more preferable. By using such an anion exchange membrane, the demetallation efficiency of the sulfonic acid metal salt having a vinyl group, the yield of the sulfonic acid having a vinyl group, the selectivity, and the removal efficiency of the ether compound having a sulfonic acid group are further improved. There is a tendency that deformation and discoloration of the anion exchange membrane can be further suppressed.

The density of the anion exchange membrane is preferably 0.70 to 1.6 g / cm ³ , more preferably 0.80 to 1.5 g / cm ³ , and still more preferably 0.90 to 1.4 g / cm ^{3. 3} . When the density of the anion exchange membrane is within the above range, the demetallation efficiency of the sulfonic acid metal salt having a vinyl group, the yield of the sulfonic acid having a vinyl group, the selectivity, and the removal of the ether compound having a sulfonic acid group The efficiency tends to be further improved.

(Cation exchange membrane)
By supplying electricity to the electrodialyzer, metal ions can be moved from the raw material chamber to the alkali chamber via the cation exchange membrane. Although it does not specifically limit as a cation exchange membrane, For example, what contains the sulfonic acid of a styrene- divinylbenzene type copolymer is mentioned. By using such a cation exchange membrane, the metal ions tend to move more easily and the electric efficiency tends to be further improved.

The density of the cation exchange membrane is preferably 0.70 to 1.6 g / cm ³ , more preferably 0.80 to 1.5 g / cm ³ , and still more preferably 0.90 to 1.4 g / cm ^{3. 3} . When the density of the cation exchange membrane is within the above range, the demetallation efficiency of the sulfonic acid metal salt having a vinyl group, the yield of sulfonic acid having a vinyl group, and the selectivity tend to be further improved.

(Raw material room)
The raw material chamber is partitioned by a cation exchange membrane and an anion exchange membrane. In the raw material chamber, an aqueous solution containing a sulfonic acid metal salt having a vinyl group is circulated, for example, by pump circulation. By passing electricity through the electrodialysis apparatus, the sulfonic acid having a vinyl group constituting the sulfonic acid metal salt having a vinyl group moves to the acid chamber, and the metal ion moves to the alkali chamber.

(Acid chamber)
The acid chamber is partitioned by an anion exchange membrane and a bipolar membrane. Preferably, pure water or a diluted aqueous solution of vinyl sulfonic acid is circulated in the acid chamber, for example, by pump circulation. By passing electricity through the electrodialyzer, the sulfonic acid having a vinyl group moves from the raw material chamber to the acid chamber via the anion exchange membrane, and H + moves to the acid chamber via the bipolar membrane. That is, a vinyl sulfonic acid aqueous solution containing a sulfonic acid having a vinyl group can be obtained from the acid chamber.

(Alkaline room)
The alkaline chamber is partitioned by a cation exchange membrane and a bipolar membrane. Pure water or an alkaline solution is circulated in the alkaline chamber by, for example, pump circulation. By supplying electricity to the electrodialyzer, metal ions move from the raw material chamber to the alkali chamber via the cation exchange membrane, and OH − moves to the alkali chamber via the bipolar membrane. Although it does not specifically limit as an alkaline solution, For example, a sodium hydroxide solution etc. are mentioned. The concentration of the alkaline solution is 3.0 N or less, preferably 0.01 to 2.0 N, and more preferably 0.1 to 0.2 N.

  The electrodialysis apparatus may include two or more stacks in parallel, with the acid chamber, the raw material chamber, and the alkali chamber as one cell, and a plurality of cells in series. The number of cells in the stack is preferably 1 to 100 pairs, and more preferably 5 to 60 pairs. When the logarithm is within the above range, the demetallation efficiency of the sulfonic acid metal salt having a vinyl group, the yield of sulfonic acid having a vinyl group, the selectivity, and the removal efficiency of an ether compound having a sulfonic acid group are further improved. Tend to.

  A cell voltage becomes like this. Preferably it is 0.1-3.0V, More preferably, it is 2.0-3.0V. “Stack voltage” means a value obtained by multiplying the cell voltage by the number of cells in series in the stack. When the cell voltage is within the above range, the demetallation efficiency of the sulfonic acid metal salt having a vinyl group, the yield of the sulfonic acid having a vinyl group, the selectivity, and the removal efficiency of the ether compound having a sulfonic acid group are further improved. It tends to improve.

The current density of the stack is preferably 10~1000A / m ^2, more preferably 100~1000A / m ^2, more preferably from 500~1000A / m ^2. “Stack current density” refers to the amount of current per unit area of the stack. When the current density of the stack is within the above range, the demetallation efficiency of the sulfonic acid metal salt having a vinyl group, the yield of the sulfonic acid having a vinyl group, the selectivity, and the removal efficiency of the ether compound having a sulfonic acid group Tend to improve more.

  The yield of sulfonic acid having a vinyl group in the electrodialysis process increases with the amount of current. The yield of the electrodialysis step is preferably 30 to 90%, more preferably 50 to 80%, and still more preferably 50 to 75%. As the yield of the electrodialysis step is improved, the selectivity and the removal efficiency of the ether compound having a sulfonic acid group saturate with time. From the viewpoint of cost, the yield of the electrodialysis step is within the above range. It is preferable. In addition, a yield can be measured by the method as described in the Example mentioned later.

(Aqueous solution containing sulfonic acid metal salt having vinyl group)
The aqueous solution is not particularly limited as long as it contains a sulfonic acid metal salt having a vinyl group. The aqueous solution may contain a saturated aliphatic hydrocarbon metal salt having a hydroxyl group and a sulfonic acid group, and a metal salt of an ether compound having a sulfonic acid group.

  The content of the sulfonic acid metal salt having a vinyl group in the aqueous solution containing the sulfonic acid metal salt having a vinyl group is, for example, 10 to 25% by mass. Moreover, content of the ether compound which has a sulfonic acid group in the aqueous solution containing the sulfonic acid metal salt which has a vinyl group is 1.0-4.0 mass%, for example. Furthermore, the content of the saturated aliphatic hydrocarbon metal salt having a hydroxyl group and a sulfonic acid group in the aqueous solution containing the sulfonic acid metal salt having a vinyl group is, for example, 1.0 to 4.0% by mass. In addition, the content of sulfuric acid in the aqueous solution containing the sulfonic acid metal salt having a vinyl group is, for example, 0.10 to 0.50% by mass.

  The sulfonic acid metal salt having a vinyl group is not particularly limited, but a vinyl sulfonic acid metal salt or an allyl sulfonic acid metal salt is preferable. By using a vinyl sulfonic acid metal salt or an allyl sulfonic acid metal salt, the yield and selectivity of a sulfonic acid having a vinyl group tend to be further improved. In addition, the sulfonic acid metal salt which has a vinyl group may be used individually by 1 type, or may use 2 or more types together.

(Vinyl sulfonic acid aqueous solution)
The aqueous vinyl sulfonic acid solution obtained by the electrodialysis step contains 7.0 to 35% by mass of a sulfonic acid having a vinyl group and 0.0030 to 2.0% by mass of an ether compound having a sulfonic acid group. Thereby, the vinyl sulfonic acid aqueous solution which can shorten heating operation time in a dehydration process and can suppress generation | occurrence | production of a viscous material can be obtained. In addition, about each component of the vinyl-type sulfonic acid aqueous solution obtained by an electrodialysis process, it is the same as that of the above.

[Method for producing purified vinyl-based sulfonic acid]
The method for producing a purified vinyl sulfonic acid product includes a dehydration step in which water is removed from the vinyl sulfonic acid aqueous solution obtained by the method for producing a vinyl sulfonic acid aqueous solution, and a vinyl sulfonic acid composition is obtained. A thin film distillation step of thin-film distillation of a vinyl sulfonic acid composition to obtain a purified vinyl sulfonic acid product, and a method for producing a purified vinyl sulfonic acid product.

[Dehydration process]
The dehydration step is a step of obtaining a vinyl sulfonic acid composition by removing water from the vinyl sulfonic acid aqueous solution obtained by the method for producing a vinyl sulfonic acid aqueous solution. Specifically, water can be removed from the aqueous vinyl sulfonic acid solution under heating under reduced pressure, but is not limited thereto.

  The degree of reduced pressure is preferably 0.50 to 30.0 kPa, and more preferably 0.50 to 10.0 kPa.

  Moreover, heating temperature becomes like this. Preferably it is 10-140 degreeC, More preferably, it is 30-130 degreeC. “Heating temperature” refers to the temperature (liquid temperature) within the dehydration system of an aqueous vinyl sulfonic acid solution.

  Furthermore, the time required for the dehydration step is preferably the time until the residual moisture content of the resulting vinyl sulfonic acid composition becomes 0.1 to 1.0%.

[Thin film distillation process]
The thin film distillation step is a step of thin-film distillation of the dehydrated vinyl sulfonic acid composition to obtain a purified vinyl sulfonic acid product. The thin film distillation step can be performed using a thin film distillation apparatus. Hereinafter, the thin film distillation apparatus will be described.

  FIG. 4 shows a schematic diagram of a thin film distillation apparatus. Although the thin film distillation apparatus is not particularly limited, for example, the lower cock 8 into which the vinyl sulfonic acid composition is introduced, the distiller body 10 that evaporates the introduced vinyl sulfonic acid composition, and the distiller body 10 A heater 3 disposed in the periphery, a stirring drive unit 4 disposed at the top of the distiller body 10, a stirring rotating unit 5 disposed in the distiller body 10, and a wiper connected to the stirring rotating unit 5 Unit 11, vacuum pump suction port 9 connected to distiller body 10, condenser 6 disposed inside distiller body 10, and vinyl system that receives sulfonic acid having a vinyl group condensed in condenser 6 The sulfonic acid receiver 1 and the residue receiver 2 arrange | positioned at the tower bottom of the distiller main body 10 are provided.

  The dehydrated vinyl sulfonic acid composition 7 is supplied to the distiller body 10 by opening the lower cock 8. The vinyl sulfonic acid composition 7 supplied to the distiller main body 10 is applied to the inner surface of the distiller main body 10 by the rotating wiper unit 11 to form a thin film of the vinyl sulfonic acid composition. When the formed thin film is heated by the heater 3, the vinyl sulfonic acid in the thin film evaporates. The evaporated vinyl sulfonic acid is cooled by the condenser 6 inside the wiper portion 11 and flows down to the vinyl sulfonic acid receiver 1. The evaporation residue that has not been evaporated by the heater 3 travels along the inner surface of the distiller body 10 and is collected in the residue receiver 2. The vacuum pump suction port 9 is used to evacuate the entire thin film distillation apparatus.

  In the thin-film distillation apparatus, it is preferable that all or a part of the portion in contact with the sulfonic acid having a vinyl group or the composition thereof is formed of a highly corrosion-resistant material. Here, the “part in contact with a sulfonic acid having a vinyl group or a composition thereof” (hereinafter, also referred to as “vinyl sulfonic acid contact part”) means a vinyl sulfonic acid composition used as a distillation raw material, an evaporated vinyl group. Means a portion in contact with a purified sulfonic acid vapor obtained by condensing the sulfonic acid vapor having a vinyl group and the sulfonic acid vapor having a vinyl group. Specific examples of the vinyl sulfonic acid contact portion include an inner wall of a distiller body, a stirring portion, a wiper portion, a condenser, a stirring seal portion, a distillation raw material inlet, a receiver, a residue discharge line, and the like.

  The high corrosion resistance material is not particularly limited, and examples thereof include JIS standard R-3503 borosilicate glass-1 and metal materials determined to be complete corrosion resistance in a corrosion resistance test method. Since the vinyl sulfonic acid contact portion is formed of a highly corrosion-resistant material, it tends to be able to suppress the mixing of impurities from these members or portions.

Although it does not specifically limit as glass which belongs to JIS specification borosilicate glass-1, For example, products, such as Pyrex (trademark), Hario (trademark), and Duran (trademark), are mentioned. “JIS standard R-3503 borosilicate glass-1” means that the linear expansion coefficient is 3.5 × 10 ⁻⁶ · K ⁻¹ or less in JIS standard (Japanese Industrial Standard) R-3503, and the amount of alkali elution Glass that is rated as 0.10 mL / g or less or 31 μg / g or less.

  Further, “a metal material determined to be completely corrosion resistant in the corrosion resistance test method” refers to a metal material having an erosion degree of 0.05 mm / year or less. Examples of the corrosion resistance test method include a. In “Handbook of Chemical Equipment” (Chemical Engineering Association, edited by Maruzen Publishing, 1970, p. 500). In accordance with the method of the item, there is a method of immersing a test piece in a sulfonic acid having a vinyl group at 165 ° C. and measuring a change in weight and a change in appearance after a certain time. In addition, a tantalum is mentioned as a metal material determined with complete corrosion resistance in a corrosion test method.

(Purified vinyl sulfonic acid)
The purified vinyl-based sulfonic acid preferably contains 95 to 99.5% by mass of a sulfonic acid having a vinyl group and 0.050 to 0.23% by mass of sulfuric acid. As a result, a purified vinyl-based sulfonic acid having excellent storage stability can be obtained. In addition, about each component of the vinyl-type sulfonic acid refinement | purification thing obtained by a thin film distillation process, it is the same as that of the above.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited in any way by the following examples.

[Content of sulfonic acid having vinyl group in vinyl-based sulfonic acid aqueous solution]
The content of the sulfonic acid having a vinyl group in the aqueous vinyl sulfonic acid solution is in accordance with JISK0070 “Testing method for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponified product of chemical products”. It was measured by the Wijs method.

[Content of ether compound having sulfonic acid group in vinyl-based sulfonic acid aqueous solution]
The content of the ether compound having a sulfonic acid group in the aqueous vinyl sulfonic acid solution was measured by an ion chromatography method. Specifically, a sample for IC was prepared by dissolving 0.2 g of the sample in 50 mL of the mobile phase. Prepare a calibration curve with linearity (correlation coefficient of 0.995 or more) using three or more standard solutions with known concentrations in advance, and contain ether compounds having sulfonic acid groups based on this calibration curve The amount was calculated.
Measuring device Device: Product name “ICS-1500” manufactured by DIONEX
Guard column: manufactured by Shimadzu Corporation, product name “Shim-pac IC-SA2 (G)”
Main column: Product name “Shim-pac IC-SA2” manufactured by Shimadzu Corporation
Suppressor: Product name “SRS-300” manufactured by DIONEX
Measurement conditions Injection volume: 20 μL
Mobile phase: Water containing 12 mM sodium bicarbonate and 0.6 mM sodium carbonate Flow rate: 1.0 mL / min
Temperature: 30 ° C
Suppressor current: 50 mA

[Water content in vinyl sulfonic acid aqueous solution]
The water content in the vinyl-based sulfonic acid aqueous solution was measured by an evaporation residue measuring method in accordance with JISK0067 “Method for reducing chemical product weight and residue”.

[Sulfuric acid content in vinyl sulfonic acid aqueous solution]
The content of sulfuric acid in the vinyl sulfonic acid aqueous solution was measured using the same apparatus and conditions as those used in the ion chromatography method used for the content of the ether compound having a sulfonic acid group in the vinyl sulfonic acid aqueous solution.

[Content of saturated aliphatic hydrocarbon having hydroxyl group and sulfonic acid group in vinyl sulfonic acid aqueous solution]
Ion chromatographic method in which the content of the saturated aliphatic hydrocarbon having a hydroxyl group and a sulfonic acid group in the aqueous vinyl sulfonic acid solution is the same as the content of the ether compound having a sulfonic acid group in the aqueous vinyl sulfonic acid solution. The measurement was performed using the same apparatus and conditions as those described above.

[Amount of metal impurities in vinyl sulfonic acid aqueous solution]
The amount of metal impurities in the vinyl sulfonic acid aqueous solution was measured by inductively coupled plasma mass spectrometry (ICP-MS (product name “X Series X7 ICP-MS” manufactured by Thermo Fisher Scientific Co., Ltd.)). The measurement sample was prepared by diluting an aqueous solution of vinyl sulfonic acid using ultrapure water obtained with an ultrapure water production apparatus (product name “Milli-Q Element A-10 EQE System” manufactured by Japan Millipore Corporation). Tables 2 and 3 show the Na content.

[Selection rate]
The selectivity in the electrodialysis process was calculated by the following formula.
Selectivity = number of moles of vinyl sulfonic acid dialyzed into acid chamber / total number of moles of sulfonic acid dialyzed into acid chamber × 100

〔yield〕
The yield in the electrodialysis step was calculated by the following formula.
Yield = number of moles of vinyl sulfonic acid dialyzed in the acid chamber / number of moles of vinyl sulfonic acid metal salt charged in the raw material chamber × 100

〔efficiency〕
The efficiency in the electrodialysis process was calculated by the following formula.
Efficiency = number of moles of vinyl sulfonic acid dialyzed into the acid chamber / (current amount × number of cells) × 100

[Content of sulfonic acid having vinyl group in vinyl sulfonic acid composition]
The content of the sulfonic acid having a vinyl group in the vinyl-based sulfonic acid composition is in accordance with JISK0070 “Testing methods for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponified product of chemical products”. , Measured by Wijs method.

[Content of ether compound having sulfonic acid group in vinyl-based sulfonic acid composition]
The content of the ether compound having a sulfonic acid group in the vinyl sulfonic acid composition is the same as that of the ion chromatographic method used in the content of the ether compound having a sulfonic acid group in the vinyl sulfonic acid aqueous solution. Measured using conditions.

[Water content in vinyl sulfonic acid composition]
The water content in the vinyl sulfonic acid composition was measured by the Karl Fischer method according to JISK0113 “Potential difference / current / electricity / General rules of Karl Fischer titration method”.

[Sulfuric acid content in vinyl sulfonic acid composition]
The content of sulfuric acid in the vinyl sulfonic acid composition was measured using the same apparatus and conditions as in the ion chromatography method used for the content of the ether compound having a sulfonic acid group in the aqueous vinyl sulfonic acid solution. .

[Content of saturated aliphatic hydrocarbon having hydroxyl group and sulfonic acid group in vinyl sulfonic acid composition]
The content of the saturated aliphatic hydrocarbon having a hydroxyl group and a sulfonic acid group in the vinyl sulfonic acid composition is the same as the ion chromatograph used in the content of the ether compound having a sulfonic acid group in the aqueous vinyl sulfonic acid solution. Measurements were made using the same equipment and conditions as the method.

[Content of sulfonic acid having vinyl group in purified vinyl sulfonic acid]
The content of sulfonic acid having a vinyl group in the purified vinyl sulfonic acid is in accordance with JISK0070 “Testing methods for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponified product of chemical products”. , Measured by Wijs method.

[Content of ether compound having sulfonic acid group in purified vinyl sulfonic acid]
The content of the ether compound having a sulfonic acid group in the purified vinyl sulfonic acid product is the same as that of the ion chromatographic method used in the content of the ether compound having a sulfonic acid group in the vinyl sulfonic acid aqueous solution. Measured using conditions. In addition, when content was below a detection limit, it showed as "trace."

[Water content in purified vinyl sulfonic acid]
The water content in the purified vinyl sulfonic acid product was measured by the Karl Fischer method according to JISK0113 “Potential difference / current / electricity / General rules of Karl Fischer titration method”.

[Sulfuric acid content in purified vinyl sulfonic acid]
The sulfuric acid content in the purified vinyl sulfonic acid product was measured using the same apparatus and conditions as the ion chromatograph method used for the content of the ether compound having a sulfonic acid group in the aqueous vinyl sulfonic acid solution. .

[Content of saturated aliphatic hydrocarbon having hydroxyl group and sulfonic acid group in the purified vinyl sulfonic acid]
The content of the saturated aliphatic hydrocarbon having a hydroxyl group and a sulfonic acid group in the purified vinyl sulfonic acid product is the ion chromatograph used in the content of the ether compound having a sulfonic acid group in the aqueous vinyl sulfonic acid solution. Measurements were made using the same equipment and conditions as the method.

[Amount of metal impurities in purified vinyl sulfonic acid]
The amount of metal impurities in the purified vinyl sulfonic acid product was measured by inductively coupled plasma mass spectrometry (ICP-MS). Table 5 shows the contents of Na and Fe.

[Storage stability test of purified vinyl sulfonic acid]
The storage stability of the purified vinyl sulfonic acid product was evaluated by measuring the purified vinyl sulfonic acid product stored for one month by gel permeation chromatography (GPC). Specifically, the area of each peak of the chart obtained by gel permeation chromatography was measured, and if the ratio of the peak area of the desulfurized compound to the total area of all the peaks was 13% or less, the vinyl type The sulfonic acid purified product was judged to be stable, and if it exceeded 13%, the vinyl sulfonic acid purified product was judged to be unstable.
Measuring device: Product name “CR-7A” manufactured by Shimadzu Corporation
Pump: manufactured by JASCO, product name “PU980”
Detection device: RI manufactured by Shimadzu Corporation
Column: manufactured by Tosoh Corporation, product name “TSK-Gel α-2500, 3000, 4000”
Measurement conditions Mobile phase: 0.2 mol / L NaNO ₃
Flow rate: 1.0 mL / min
Temperature: 40 ° C
Sample: 2 wt%, 20 μL

[Example 1]
(Electrodialysis process)
500 mL of 25% -vinyl vinyl sulfonate aqueous solution was charged in the raw material chamber, 300 mL of pure water was charged in the acid chamber, and 300 mL of 0.2 N NaOH aqueous solution was charged in the alkali chamber. With the maximum current value set at 5.5A, the operation voltage was kept constant at 30V. An vinyl sulfonic acid aqueous solution was obtained with an energization time of 150 minutes (current amount: 0.49 Faraday) at which the conductivity of the acid chamber became substantially stable as the end point. The conditions for the electrodialysis step are shown in Table 1. The amount of dialysis completed in the raw material chamber, acid chamber, and alkali chamber was measured, and the composition analysis of the solution obtained from each chamber was performed. The results are shown in Table 2.

(Experimental conditions)
Apparatus: Acylizer EX-3B type (manufactured by Astom Co., Ltd.)
Electrode: Ni
Anion membrane: AHA (anion membrane having the above structure (a), manufactured by Astom Co., Ltd.)
Cationic membrane: CMX (manufactured by Astom Co., Ltd.)
Bipolar membrane: BP-1E (manufactured by Astom Co., Ltd.)
Electrode solution: 1N NaOH 500mL
Number of cells: 10 vs. Stack voltage: 25V
Electrode voltage: 30V
Total membrane area: 0.055 m ²

[Example 2]
The vinyl sulfonic acid aqueous solution was obtained in the same manner as in Example 1 except that the energization time was extended and the energization time was changed to 180 minutes (current amount 0.59 Faraday). Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

Example 3
The vinyl sulfone solution was operated in the same manner as in Example 1 except that the concentration of the sodium vinyl sulfonate aqueous solution charged in the raw material chamber was halved to 12.5% and the energization time was changed to 75 minutes (current amount 0.23 Faraday). An acid aqueous solution was obtained. Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

Example 4
The vinyl sulfonic acid aqueous solution was obtained in the same manner as in Example 3 except that the energization time was halved and the energization time was changed to 37 minutes (current amount 0.11 Faraday). Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

Example 5
A vinyl sulfonic acid aqueous solution was obtained in the same manner as in Example 1 except that the anion membrane was replaced with AHA and the anion membrane (AMX, manufactured by Astom Co., Ltd.) having the above structure (b) was used. Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

Example 6
A vinylsulfonic acid aqueous solution was obtained in the same manner as in Example 1 except that the anion membrane was replaced with AHA and the anion membrane (ACM, manufactured by Astom Co., Ltd.) having the above structure (c) was used. Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

Example 7
A vinylsulfonic acid aqueous solution was obtained in the same manner as in Example 1 except that the anion membrane was replaced with AHA and the anion membrane (ACS, manufactured by Astom Co., Ltd.) having the above structure (b) was used. Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

[Example 8-1]
In order to confirm the transition of electrodialysis over time, a vinylsulfonic acid aqueous solution was obtained in the same manner as in Example 1 except that the energization time was 30 minutes (current amount 0.05 Faraday). Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

[Example 8-2]
In order to confirm the transition of electrodialysis over time, a vinylsulfonic acid aqueous solution was obtained in the same manner as in Example 1 except that the energization time was 60 minutes (current amount 0.11 Faraday). Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

[Example 8-3]
In order to confirm the transition of electrodialysis over time, a vinylsulfonic acid aqueous solution was obtained in the same manner as in Example 1 except that the energization time was 150 minutes (current amount 0.44 Faraday). Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

[Example 8-4]
In order to confirm the transition of electrodialysis over time, a vinylsulfonic acid aqueous solution was obtained in the same manner as in Example 1 except that the energization time was 240 minutes (current amount: 0.76 Faraday). Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

Example 9
Except that the amount of 25% sodium vinyl sulfonate charged in the raw material chamber is increased to 800 mL, the pure water in the acid chamber and 0.2 N NaOH in the alkaline chamber are reduced to 200 mL, and the amount of current is 0.80 Faraday. Were operated in the same manner as in Example 1 to obtain an aqueous vinylsulfonic acid solution. Table 2 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

Example 10
The allyl sulfonic acid aqueous solution was obtained in the same manner as in Example 1 except that the 25% sodium vinyl sulfonate aqueous solution was used instead of the 25% sodium vinyl sulfonate aqueous solution in the raw material chamber. It was. The analysis results of the obtained allyl sulfonic acid aqueous solution are shown in Table 2.

[Comparative Example 1]
In place of the electrodialysis method, a 9% -vinyl vinyl sulfonate aqueous solution was used, and an about 2% by mass vinyl sulfonic acid aqueous solution was obtained by an ion exchange resin process.

  Specifically, the column was filled with an ion exchange resin (1000 mL of Dowex Monosphere 650C) to prepare an ion exchange resin column. The ion exchange resin column was fixed vertically, a beaker serving as a receiver was installed below the ion exchange resin column, and a dropping funnel containing 1500 mL of a 9% -vinyl vinyl sulfonate aqueous solution was installed above the ion exchange resin column. .

  The sodium vinyl sulfonate aqueous solution was dropped from the dropping funnel to the ion exchange resin column, and the sodium vinyl sulfonate aqueous solution that passed through the ion exchange resin column was obtained in the receiver. After all 1500 mL of 9% -sodium vinyl sulfonate aqueous solution was dropped, in order to co-wash the sodium vinyl sulfonate aqueous solution for the ion-exchange resin adsorption, 5000 mL of additional wash water was further dropped from the dropping funnel onto the ion exchange resin column. After passing through the ion exchange resin column, the washing water was also collected in the receiver. Table 3 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

[Comparative Example 2]
In place of 9% -vinyl vinyl sulfonate aqueous solution, 530 mL of 25% -sodium vinyl sulfonate aqueous solution was used, and operation was performed in the same manner as in Comparative Example 1 except that the post-washing water was not used. A sulfonic acid aqueous solution was obtained. Table 3 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

[Comparative Example 3]
The same procedure as in Example 1 was carried out except that the acid chamber feed solution was replaced with pure water and an aqueous solution containing 3.0% of saturated aliphatic hydrocarbons having hydroxyl groups and sulfonic acid groups, and hydroxyl groups and A vinylsulfonic acid aqueous solution having a high content of saturated aliphatic hydrocarbons having sulfonic acid groups was obtained. Table 3 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

[Comparative Example 4]
The content of the ether compound having a sulfonic acid group was changed in the same manner as in Example 1 except that the charged solution in the acid chamber was replaced with pure water to make an aqueous solution containing 2.7% of the ether compound having a sulfonic acid group. An aqueous vinyl sulfonic acid solution with a large amount was obtained. Table 3 shows the analysis results of the obtained vinyl sulfonic acid aqueous solution.

[Comparative Example 5]
The sulfonic acid metal salt charged in the raw material chamber was replaced with a 25% sodium vinyl sulfonate aqueous solution and replaced with a 25% sodium methallyl sulfonic acid aqueous solution. Got. Table 3 shows the analysis results of the resulting aqueous methallylsulfonic acid solution.

[Comparative Example 6]
The styrene sulfonic acid aqueous solution was prepared in the same manner as in Example 1 except that the metal sulfonic acid salt charged in the raw material chamber was replaced with a 25% sodium vinyl sulfonate aqueous solution and a 10% sodium styrene sulfonate aqueous solution was used. Obtained. Table 3 shows the analysis results of the obtained aqueous styrene sulfonic acid solution.

Example 11
(Dehydration process)
A 500 mL four-necked flask was equipped with a thermometer, a stirrer, and a T-tube for controlling the liquid temperature. A thermometer was installed above the T-shaped tube, and a Liebig cooler was installed on the side. A receiver for collecting the distillate was installed at the end of the cooler. A vacuum pump was attached to the receiver. Into the four-necked flask, 350 mL of the vinyl sulfonic acid aqueous solution obtained in Example 1 was charged, and the four-necked flask was attached to an oil bath with a thermometer to start distillation. During distillation, the internal pressure of the flask was set to 10 KPa or less, the internal temperature (liquid temperature) was maintained at 30 to 40 ° C., and vacuum distillation was performed for 4 hours. Thereby, the moisture content became 25% or less, and coloring or the like was not confirmed.

  Furthermore, the internal temperature was raised to 45 ° C., and vacuum distillation was performed for 2 hours (6 hours in total). As a result, the water content was 15% or less, and light coloring was confirmed.

  Further, the temperature was raised to 130 ° C., and vacuum distillation was performed for 2 hours (total 8 hours). As a result, a vinyl sulfonic acid composition having a moisture content of 1% or less was obtained. The vinyl sulfonic acid composition after the dehydration step was colored to reddish brown, but no viscous material was produced. Table 4 shows the analysis results of the obtained vinyl sulfonic acid composition.

(Thin film distillation process)
The obtained vinyl sulfonic acid composition was divided into three equal parts (R-1 to 3), and each was heated to 140 to 150 ° C. in a high vacuum state (200 Pa or less) using the apparatus shown in FIG. A distillation operation was performed. From the above, a purified product of vinyl sulfonic acid was obtained. Table 5 shows the analysis results of the resulting purified vinyl sulfonic acid.

Example 12
A vinyl sulfonic acid composition was obtained in the same manner as in Example 11 except that the vinyl sulfonic acid aqueous solution obtained in Example 9 was used instead of the vinyl sulfonic acid aqueous solution obtained in Example 1. . The dehydration process took 8 hours as in Example 11. No viscous material was produced in the vinyl sulfonic acid after the dehydration step. Using the obtained vinyl sulfonic acid composition, a thin film distillation operation was performed in the same manner as in Example 11 to obtain a purified vinyl sulfonic acid product. The analysis results of the obtained vinyl sulfonic acid composition and the purified vinyl sulfonic acid are shown in Tables 4 to 5.

[Comparative Example 7]
Instead of the vinyl sulfonic acid aqueous solution obtained in Example 1, 350 mL of the vinyl sulfonic acid aqueous solution obtained in Comparative Example 1 was charged, and vacuum distillation was performed for 4 hours while maintaining the internal temperature at 30 to 40 ° C. at 10 KPa or less. It was. As a result, the water content was 35% or less, the solution was colored yellow, and a slight turbidity was confirmed.

  Furthermore, the internal temperature was raised to 45 ° C., and vacuum distillation was performed for 2 hours (6 hours in total). Thereby, the water content became 15% or less, and brown coloring and turbidity were confirmed.

  Further, the temperature was raised to 130 ° C., and vacuum distillation was performed for 2 hours (total 8 hours). Thereby, the moisture content became 1% or less. The time used for vacuum distillation was 8 hours as in Example 11. Moreover, although a viscous substance did not arise in the vinyl sulfonic acid composition after a dehydration process, the tar-like floating substance was confirmed.

  Since the thin film distillation operation cannot be performed with the vinyl sulfonic acid composition after the dehydration step as it is, the insoluble matter is removed by filtering the vinyl sulfonic acid composition after the dehydration step using a 200 mesh polypropylene filter cloth. Then, thin film distillation operation was performed in the same manner as in Example 11 to obtain a purified vinyl sulfonic acid. The analysis results of the obtained vinyl sulfonic acid composition and the purified vinyl sulfonic acid are shown in Tables 4 to 5.

[Comparative Example 8]
A vacuum distillation was performed in the same manner as in Comparative Example 7 except that the vinyl sulfonic acid aqueous solution obtained in Comparative Example 2 was used in place of the vinyl sulfonic acid aqueous solution obtained in Comparative Example 1. Because of the high metal content, sodium metal salt was precipitated during the dehydration step, and a vinyl sulfonic acid composition capable of performing a thin film distillation operation was not obtained.

[Comparative Example 9]
A vinyl sulfonic acid composition was obtained in the same manner as in Example 11 except that the vinyl sulfonic acid aqueous solution obtained in Comparative Example 3 was used instead of the vinyl sulfonic acid aqueous solution obtained in Example 1. . In the dehydration step, 9 hours were required because the dehydration operation time at 130 ° C. was extended by 1 hour compared with Example 11 in order to achieve a moisture content of 1% or less. No viscous material was produced in the vinyl sulfonic acid composition after the dehydration step. Using the obtained vinyl sulfonic acid composition, a thin film distillation operation was performed in the same manner as in Example 11 to obtain a purified vinyl sulfonic acid product. The analysis results of the obtained vinyl sulfonic acid composition and the purified vinyl sulfonic acid are shown in Tables 4 to 5.

[Comparative Example 10]
The same operation as in Example 11 was performed except that the vinyl sulfonic acid aqueous solution obtained in Comparative Example 4 was used instead of the vinyl sulfonic acid aqueous solution obtained in Example 1. Some black smoke was generated in the flask during the dehydration process, and the viscosity increased. When the water content in the vinyl sulfonic acid composition became 2% or less in the dehydration step, the vinyl sulfonic acid composition became a thickened solution, and the dehydration step was stopped.
In addition, the obtained vinyl sulfonic acid composition did not have fluidity, and the vinyl sulfonic acid composition which can perform thin film distillation operation was not obtained. Table 4 shows the analysis results of the obtained vinyl sulfonic acid composition.

ＳＶＳ ：ビニルスルホン酸ナトリウム
ＳＡＳ ：アリルスルホン酸ナトリウム
ＳＭＡＳ：メタリルスルホン酸ナトリウム
ＳＳＳ ：スチレンスルホン酸ナトリウム

SVS: Sodium vinyl sulfonate SAS: Sodium allyl sulfonate SMAS: Sodium methallyl sulfonate SSS: Sodium styrene sulfonate

「-」は未測定を意味する。

“-” Means unmeasured.

  The aqueous vinyl sulfonic acid solution and the purified vinyl sulfonic acid of the present invention have industrial applicability as monomers constituting functional polymers and conductive materials.

DESCRIPTION OF SYMBOLS 1 ... Vinyl-type sulfonic acid receiver, 2 ... Residue receiver, 3 ... Heater, 4 ... Agitation drive part, 5 ... Agitation rotation part, 6 ... Condenser, 7 ... Dehydrated vinyl-type sulfone composition, 8 ... Lower cock , 9 ... Vacuum pump suction port, 10 ... Distiller body, 11 ... Wiper part

Claims (8)

7 to 35% by mass of a sulfonic acid having a vinyl group;
0.0030 to 2.0% by mass of an ether compound having a sulfonic acid group, and a vinyl sulfonic acid aqueous solution ,
The sulfonic acid having a vinyl group is a vinyl sulfonic acid aqueous solution containing vinyl sulfonic acid or allyl sulfonic acid .   The aqueous vinyl sulfonic acid solution according to claim 1, further comprising 0.030 to 1.0% by mass of sulfuric acid.   The vinyl sulfonic acid aqueous solution according to claim 1 or 2, wherein the sulfonic acid having a vinyl group has a molecular weight of 100 to 150. An electrodialysis step of supplying an aqueous solution containing a vinyl group-containing sulfonic acid metal salt to a raw material chamber of an electrodialyzer and performing electrodialysis to obtain a vinyl-based sulfonic acid aqueous solution;
In the electrodialysis apparatus, an anion exchange membrane and a cation exchange membrane are disposed between two anode membranes provided between an anode and a cathode so that the anion exchange membrane side faces the anode side. The acid chamber partitioned by the bipolar membrane and the anion exchange membrane, the raw material chamber partitioned by the anion exchange membrane and the cation exchange membrane, and partitioned by the cation exchange membrane and the bipolar membrane. Has an alkaline chamber,
The aqueous vinyl sulfonic acid, viewed contains a 7 to 35 wt% acid having a vinyl group, 0.0030 to 2.0 mass% ether compound having a sulfonic acid group, a,
The sulfonic acid metal salt having a vinyl group includes sodium vinyl sulfonate or sodium allyl sulfonate,
A method for producing an aqueous vinyl sulfonic acid solution. The vinyl system according to claim 4 , wherein the bipolar membrane includes a cation exchanger containing a sulfonic acid of a styrene-divinylbenzene copolymer and an anion exchanger containing a quaternary ammonium compound of a polystyrene polymer. A method for producing an aqueous sulfonic acid solution. The said anion exchange membrane is a manufacturing method of the vinyl-type sulfonic acid aqueous solution of Claim 4 or 5 containing the quaternary ammonium compound of a styrene divinylbenzene type polymer. The said cation exchange membrane is a manufacturing method of the vinyl-type sulfonic acid aqueous solution of any one of Claims 4-6 containing the sulfonic acid of a styrene- divinylbenzene type copolymer. A dehydration step of removing water from the vinyl sulfonic acid aqueous solution obtained by the method for producing a vinyl sulfonic acid aqueous solution according to any one of claims 4 to 7 to obtain a vinyl sulfonic acid composition;
A method for producing a purified vinyl-based sulfonic acid, comprising: a thin-film distillation step of thin-film distillation of the composition to obtain a purified vinyl-based sulfonic acid.

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