JP2012001508A - Method for producing olefin chlorohydrin compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an olefin chlorohydrin compound, efficiently utilizable of byproduct hydrogen chloride for producing an end product without using a neutralizing agent irrelevant to the production of the end product while using a neutralizing agent that can be utilized to the maximum extent for producing the end product.SOLUTION: The method for producing an olefin chlorohydrin compound, including a reaction step of producing an olefin chlorohydrin compound by allowing hypochlorous acid obtained by dissolving chlorine into water to react with an olefin compound, is characterized by controlling the pH of the reaction system in a range of 2 to 7 by virtue of a hypochlorite.

Description

  The present invention relates to a method for producing an olefin chlorohydrin.

Conventionally, a method for producing olefin chlorohydrin by reacting chlorine, water and alkene is known (Non-patent Document 1). The reaction is (1) hypochlorous acid (HOCl) by reaction of chlorine and water. And hydrogen chloride (HCl) and (2) the production of olefin chlorohydrin by the reaction of olefin and hypochlorous acid.
Since the reaction of (1) is an equilibrium reaction, it usually does not proceed when a certain ratio is reached. However, hypochlorous acid generated by the reaction is added to the double bond of olefin by the reaction of (2), and olefin chloro By being consumed as hydrin, the equilibrium of (1) further tilts to the right, and chlorine reacts with water.
However, since hydrogen chloride by-produced in (1) is not consumed, this reaction eventually reaches an equilibrium, and chlorine does not react with water. As a result, there was a problem that chlorine was dissolved in water as it was, and the dissolved chlorine was added to the double bond of olefin, whereby olefin dichloride was by-produced.

Therefore, a method has been studied in which by-products of olefin dichloride are suppressed by adding an alkali or an alkali salt to the reaction system to neutralize hydrogen chloride (Patent Document 1).
However, in this method, by-produced hydrogen chloride and the alkali or alkali salt for neutralizing it are components that are not related to the production of the olefin chlorohydrin itself, and are simply waste in the production process. As a result, the manufacturing cost is increased.

J. Am. Chem. Soc., 41, p1419 (1919)

JP-A-6-25037

  The present invention has been made in view of the above problems, and without using a neutralizing agent that is not related to the production of the final product, while utilizing a neutralizing agent that can be used to the maximum extent for the final product, It is an object of the present invention to provide a method for producing an olefin chlorohydrin compound that can efficiently use by-produced hydrogen chloride as a final product.

The present invention includes the following inventions.
(1) A reaction step in which hypochlorous acid obtained by dissolving chlorine in water is reacted with an olefin compound to obtain an olefin chlorohydrin compound, and the reaction system is reacted with hypochlorite. adjusting the pH to 2 to 7, a process for producing an olefin chlorohydrin compound,
(2) The production of the olefin chlorohydrin compound according to (1), wherein the hypochlorite is at least one selected from sodium hypochlorite, potassium hypochlorite, and calcium hypochlorite. Method,
(3) The method for producing an olefin chlorohydrin compound according to (1) or (2), wherein the olefin compound is at least one selected from ethylene, propylene, and allyl chloride.

  According to the present invention, a neutralizing agent that can be utilized to the maximum extent for the final product can be used without using a neutralizing agent that is not related to the production of the final product. Further, by-product hydrogen chloride can also be efficiently used for the final product, and an olefin chlorohydrin compound can be produced economically and effectively.

In the present invention, the olefin chlorohydrin compound can be produced by reacting hypochlorous acid with an olefin compound.
As hypochlorous acid, one produced by a known method and conditions can be used. For example, one obtained by dissolving chlorine in water can be used. In this case, since chlorine is normally supplied in a gas, it is preferable that the supply amount is 10 to 50 sccm with respect to 100 g of water. The concentration of hypochlorous acid is not particularly limited, but the stability is poor at a high concentration, so 25% by weight or less is suitable.

The olefin compound to be reacted with hypochlorous acid is not particularly limited, but olefins such as ethylene, propylene, n-butylene, and allyl compounds, and olefin halides such as allyl chloride, allyl bromide, allyl fluoride, and allyl iodide. Etc.
In the present invention, a step of preparing hypochlorous acid, that is, a step of reacting chlorine and water by dissolving chlorine in water, a step of reacting hypochlorous acid and an olefinic compound, and However, it is usually preferable to carry out these steps simultaneously. In this case, the olefinic compound is generally supplied as a gas, but the olefinic compound may be mixed with the hypochlorous acid used.

When hypochlorous acid is reacted with an olefinic compound, it is suitable to use hypochlorite to adjust the reaction system to pH 2-7.
Although it does not specifically limit as a hypochlorite used here, Sodium hypochlorite, potassium hypochlorite, calcium hypochlorite etc. are suitable from availability. These hypochlorites make the equilibrium reaction between chlorine and water easier to proceed by reacting with hydrogen chloride by-produced in the reaction system and reducing its concentration. Furthermore, hypochlorite itself becomes hypochlorous acid by reaction with hydrogen chloride produced as a by-product, and is used for reaction with olefins. For this reason, hypochlorous acid can be effectively utilized to the maximum extent in the reaction system.
When hypochlorite is excessively added to the reaction system, the reaction system becomes strongly alkaline, and tends to cause dehydrochlorination from the generated olefin chlorohydrin to generate an olefin oxide. Moreover, when there is too little addition, reaction with chlorine and water cannot fully advance, but there exists a tendency for olefin dichloride to byproduce. Therefore, it is preferable to add hypochlorite appropriately in a timely manner so as to keep the reaction system at about pH 2 to 7, preferably about pH 4 to 6.

Since the reaction proceeds sufficiently even at room temperature, heating is not particularly required, but a range of 0 ° C. to room temperature is desirable in order to further promote the reaction between chlorine and water.
These reactions can be performed using conventional reactors. For example, any of a batch type reactor or a continuous type reactor can be used.
The olefin chlorohydrin compound obtained by the reaction can be recovered by a method known in the art and may be further purified. For example, a method such as precision distillation is exemplified.

Below, the manufacturing method of the olefin chlorohydrin type compound of this invention is demonstrated in detail.
The reaction apparatus and measurement method used in the following examples are shown.
The reaction of the olefin chlorohydrin compound was carried out using a glass reaction vessel having a capacity of 500 ml. Hypochlorite was added dropwise little by little at the same time as chlorine gas was blown to obtain a hypochlorous acid aqueous solution. An olefin chlorohydrin was obtained by injecting the olefin therein.
The reaction solution was gas chromatograph (manufactured by Shimadzu Corporation, trade name GC-2010), capillary column (manufactured by Agilent J & W, trade name DB-1, 30 m × 0.25 mm (inner diameter), film thickness 1.0 μm), hydrogen flame ionization detection. Quantification was performed using a vessel (FID).
The composition ratio of the reaction product was calculated by the following formula.
Each product (mol%) = 100 × [each product amount (mol) / total product amount (mol)]

Example 1
Add 350 g of water to a glass reaction vessel, dissolve sodium hypochlorite with an effective chlorine concentration of 5%, and dissolve chlorine gas for 30 minutes with stirring at a rate of 0.05 L / min. A chlorous acid aqueous solution was prepared. Thereto, ethylene gas was blown for 60 minutes while stirring at a rate of 0.03 L / min to obtain ethylene chlorohydrin.
The reaction temperature was adjusted to 4 ° C.
The composition of the product was 95.5 mol% ethylene chlorohydrin, 3.6 mol% ethylene dichloride, and 0.9 mol% ethylene oxide.

Example 2
400 g of water is put into a glass reaction vessel, 15 g of calcium hypochlorite having an effective chlorine concentration of 70% is dissolved, and chlorine gas is dissolved for 30 minutes with stirring at a rate of 0.05 L / min. A chlorous acid aqueous solution was prepared. Thereto, ethylene gas was blown for 60 minutes while stirring at a rate of 0.03 L / min to obtain ethylene chlorohydrin.
The reaction temperature was adjusted to 4 ° C.
The composition of the product was 96.1 mol% ethylene chlorohydrin, 3.1 mol% ethylene dichloride, and 0.8 mol% ethylene oxide.

Example 3
Add 350 g of water to a glass reaction vessel, dissolve sodium hypochlorite with an effective chlorine concentration of 5%, and dissolve chlorine gas for 30 minutes with stirring at a rate of 0.05 L / min. A chlorous acid aqueous solution was prepared. Thereto, 5.0 g of allyl chloride was dropped over 60 minutes to obtain dichloropropanol. The reaction temperature was adjusted to 4 ° C.
The composition of the product was 94.9 mol% dichloropropanol, 4.6 mol% trichloropropane, and 0.5 mol% ethylene oxide.

Comparative Example 1
350 g of water was placed in a glass reaction vessel, and chlorine gas was dissolved for 30 minutes while stirring at a rate of 0.05 L / min to prepare a hypochlorous acid aqueous solution having a pH of 0.7. Thereto, ethylene gas was blown for 60 minutes while stirring at a rate of 0.03 L / min to obtain ethylene chlorohydrin. The reaction temperature was adjusted to 4 ° C.
The composition of the product was 75.2 mol% ethylene chlorohydrin and 24.8 mol% ethylene dichloride.

  According to the present invention, hydrogen chloride produced as a by-product is not wasted, a neutralizing agent that has nothing to do with the production process is used, and the utilized neutralizing agent can be utilized to the maximum in the production process. The manufacturing method of the olefin chlorohydrin type compound which can be provided can be provided.

Claims (3)

  A reaction step of reacting hypochlorous acid obtained by dissolving chlorine in water with an olefinic compound to obtain an olefin chlorohydrin compound, wherein the pH of the reaction system is reduced to 2 with hypochlorite. A process for producing an olefin chlorohydrin compound, characterized by adjusting to ˜7.   The method for producing an olefin chlorohydrin compound according to claim 1, wherein the hypochlorite is at least one selected from sodium hypochlorite, potassium hypochlorite, and calcium hypochlorite.   The method for producing an olefin chlorohydrin compound according to claim 1 or 2, wherein the olefin compound is at least one selected from ethylene, propylene, and allyl chloride.