KR102006819B1 - Method for preparing vinylidene chloride - Google Patents

Abstract

The present invention utilizes a continuous stirred tank reactor having one or more stage impellers, and the stirring force and aqueous alkali solution of the reactor, thereby dehydrohalogenation of 1,1,2-trichloroethane without addition of a phase transfer catalyst. It relates to a method for producing vinylidene chloride which can improve the reactivity of the conventional.

Description

Method for preparing vinylidene chloride {Method for preparing vinylidene chloride}

The present invention relates to a method for producing vinylidene chloride which can increase the reactivity by improving the dehalogenation hydrogenation reaction (preferably, dechlorination hydrogenation reaction).

In general, vinylidene chloride is prepared by adding a phase transfer catalyst to 1,1,2-trichloroethane and then performing dechlorination hydrogenation. The vinylidene chloride has been used as a precursor for additives or monomers, herbicides, and pharmaceutical raw materials for producing various plastic film materials in chemical processes.

For example, in US Patent No. 02610214, Japanese Patent Publication No. 1981-057721, Chinese Patent Publication No. 100868987, and Chinese Patent Publication No. 100868986, all use a phase transfer catalyst in an aqueous alkali solution to dehydrogenate hydrogenation. Proceeded. The phase transfer catalyst used here is in the form of a nitrogen salt such as quaternary ammonium salt, which helps to mix NaOH present in the aqueous solution with 1,1,2-trichloroethane.

However, the phase change catalyst added for the improvement of the dechlorination hydrogenation reaction is not only expensive but also difficult to purify and remove it from the reactants after the reaction. Therefore, there is a need for the development of a new method with improved dechlorination hydrogenation without using a phase transfer catalyst.

An object of the present invention is to provide a method for producing vinylidene chloride which can increase the dehydrochlorination reactivity without the use of a phase transfer catalyst for improving the reactivity as before.

The present invention comprises the steps of adding 1,1,2-trichloroethane and basic aqueous solution to a continuous stirred tank reactor (CSTR) with an impeller; And

Performing a dechlorination hydrogenation reaction for 1 to 60 minutes at an agitation force of 500 to 3000 W / m ³ ;

It provides a method for producing vinylidene chloride comprising a.

The impeller in the reactor consists of a rushton turbine (radial type), paddle (paddle), pitched paddle type (axial type), propeller, hydrofoil and paudler (pfaudler) It is preferable to include at least one stirring means selected from the group of one or more.

The basic aqueous solution may be a basic aqueous solution including 2 to 15% by weight of NaOH and 0 to 25% by weight of NaCl.

The basic aqueous solution is preferably added at 1.0 to 1.5 molar ratio with respect to 1.0 mole of 1,1,2-trichloroethane.

The operating conditions of the continuous stirred tank reactor is preferably maintained at a temperature of 70 to 110 ℃ under 0 barg to 10 barg pressure.

The present invention utilizes a continuous stirred tank reactor equipped with a specific impeller, and at the same time vinylidene chloride which can improve the dechlorination hydrogenation reactivity of 1,1,2-trichloroethane by appropriately adjusting the stirring force to a certain range. It can provide the effect of manufacturing. In addition, in the present invention, since only 1,1,2-trichloroethane and NaOH aqueous solution need to be used according to the above structure, purification after the reaction is easy, and thus the efficiency of the process can be improved, and the need for using an expensive phase transfer catalyst is economical. Has an effect.

1 illustrates an impeller type provided in a reactor according to an embodiment of the present invention.
Figure 2 briefly shows a manufacturing process of the vinylidene chloride in accordance with an embodiment of the present invention.
Figure 3 shows a comparison of the reaction rate according to the presence or absence of the addition and the stirring power of the phase transfer catalyst of Comparative Examples 1 to 5 and Example 1.
Figure 4 shows a comparison of the reaction rate according to the stirring force for Comparative Example 1 and Examples 1-2.

Hereinafter, the present invention will be described in more detail. In addition, the present invention may be variously modified and have various forms, and specific embodiments will be illustrated and described in detail below. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

In addition, the meaning of “comprising” as used in the specification of the present invention embodies a particular characteristic, region, integer, step, operation, element and / or component, and other characteristics, region, integer, step, operation, element and / or It does not exclude the presence or addition of ingredients.

Hereinafter, the manufacturing method of vinylidene chloride which raises the reactivity of the preferable dechlorination hydrogenation reaction of this invention is demonstrated in detail.

According to one embodiment of the invention, the step of adding 1,1,2-trichloroethane and basic aqueous solution to a continuous stirred tank reactor (CSTR) with an impeller; And performing a dechlorination hydrogenation reaction for 1 to 60 minutes at a stirring power of 500 to 3000 W / m ^3. Provided is a method for preparing vinylidene chloride.

In other words, the conventional method used a phase transition catalyst such as quaternary ammonium salt to increase the reactivity of the dechlorination hydrogenation reaction.

However, according to the experimental results of the present invention, it was confirmed that increasing the agitation force is more effective in increasing the reactivity than using a phase transfer catalyst in the dechlorination hydrogenation for producing vinylidene chloride, and completed the present invention.

Specifically, the present invention prepares 1,1,2-trichloroethane and basic aqueous solution as a chloride reactant to carry out the process of producing vinylidene chloride.

In particular, the present invention uses a continuous stirred tank reactor (CSTR) to perform the dechlorination hydrogenation reaction, by appropriately adjusting the stirring force of the reactor, the reaction of the reactant and the basic aqueous solution without using a conventional phase transfer catalyst Alone can exhibit excellent dechlorination hydrogenation. In this case, the continuous stirred tank reactor may be a multi-stage reactor, characterized in that it comprises an impeller. In addition, the reactor may be provided with one or more, they may be connected to each other to proceed a continuous process. A rectifier may be connected to the reactor.

In addition, the impeller in the specification of the present invention is connected to the upper portion of the continuous stirred tank reactor is provided, means the stirring means formed on the stirring shaft. The stirring shaft may also include a drive including a drive shaft for rotating the impeller in the reactor, the drive shaft may be driven according to methods well known in the art.

Specifically, the dechlorination hydrogenation reaction according to the present invention is a liquid-liquid biphasic reaction, and it is important to send vinylidene chloride as a product after the reaction to the top of the reactor. Therefore, in the present invention, by controlling the rotation and stirring force of the impeller included in the reactor, vinylidene chloride can be obtained in a more effective way than the conventional, and then sent to the top of the reactor can be easily recovered.

In addition, in the present invention, various types of impeller types may be used as long as the stirring force is increased, and reactivity may be improved by using a reactor having such an impeller.

For example, the impeller in the reactor consists of a rushton turbine (radial type), paddle (paddle), pitched paddle type (axial type), propeller, hydrofoil and pfaudler It is preferable to include at least one stirring means selected from the group of one or more. Including one or more stages of the said impeller means the apparatus provided with the stirring means of the 1st stage or the 1st stage or more stages centering on the stirring shaft of a reactor. The paddle may comprise a 90 degree 3-6 blade paddle at 90 ° type.

The impeller is connected from the top of the reactor may be included in one or more stages around the stirring shaft. In one example, the impeller may be provided in one or two stages in the reactor. When the impeller is provided in the reactor in one stage, an impeller may be included at the lower end of the stirring shaft of the reactor. In addition, when the impeller is provided in the reactor in two stages, the stirring shaft of the reactor may be included in the upper and lower points of the bisection.

In addition, the impeller is a single stage or two centered around the stirring shaft by combining a single or one or more of a rushton turbine (radial type), paddle (paddle), or pitched paddle type (axial type) It is preferable to include in a stage.

An example of the reactor including the impeller of the present invention is as shown in FIG.

In FIG. 1, (a) is an example provided with an impeller with a pitched paddle type at both the upper and lower ends about the stirring axis of the reactor (two stage configuration); (b) is an example having a paddle type as an impeller at the top and a pitched paddle type as the impeller at the top of the stirring shaft of the reactor (two stage configuration); (c) is an example having a pitched paddle type as an impeller at the top and a paddle type as the impeller at the top of the stirring shaft of the reactor (two stage configuration); (d) is an example in which a paddle type is provided as an impeller at both the top and bottom centers around the stirring shaft of the reactor (two stage configuration); (e) is an example provided with an impeller with a pitched paddle type at the lower end about the stirring axis of the reactor (single stage configuration); (f) is an example provided with a paddle type impeller at the lower end with respect to the stirring shaft of a reactor (one-stage structure). Pitched paddles in the impeller is excellent in the effect of increasing the internal cracking degree and OH-conversion rate, it is excellent in the production effect of vinylidene chloride. In addition, when the pitched paddle is used as an impeller, vinylidene chloride prepared by a dechlorination hydrogenation can be smoothly sent to the top of the reactor for easy recovery. In addition, the paddle type of the impeller has an effect of increasing the reaction speed.

In addition, in the present invention, the use of the impeller can give a uniform effect of the small reactant particles, evenly disperse the solid NaCl, it is possible to prevent the smooth product recovery and channeling of the continuous stirred tank reactor.

Such an impeller is preferably formed in one or two stages by selecting a pitched paddle and a paddle type. Most preferably, the impeller in the reactor comprises one or two stages of pitched paddles. Thus, examples of (a) and (e) in FIG. 1 are most preferred.

In addition, the present invention is characterized in that to improve the reactivity by using a continuous stirred tank reactor having the impeller at the same time, by adjusting the stirring force of the impeller to a certain range. That is, even if the reactor includes an impeller, if the stirring force is not controlled, the reactivity may be too low, or the reaction process may be inefficient.

Therefore, in the present invention, it is preferable to perform a dehalogenation hydrogenation reaction (that is, dechlorination hydrogenation reaction) for 1 to 60 minutes at a stirring power of 500 to 3000 W / m ³ . More preferably, the stirring force may be 1000 to 3000 W / m ³ . At this time, if the stirring force is less than 500 W / m ³ can not be expected to improve the dehydrochlorination reaction due to too slow stirring, the reaction effect is insignificant compared to the fast stirring force if the stirring force is 3000 W / m ³ or more There is. At this time, the unit of "W / m ³ " in the specification of the present invention is to indicate the stirring force of the reactor, it may mean the stirring power density of the impeller provided in the reactor.

And, The operating conditions of the continuous stirred tank reactor may be preferably maintained at a temperature of 70 to 110 ℃ under 0 barg to 10 barg pressure.

On the other hand, the basic aqueous solution may be a basic aqueous solution containing 2 to 15% by weight of NaOH and 0 to 25% by weight of NaCl.

For example, the basic aqueous solution may be an aqueous solution including 2 wt% NaOH and 25 wt% NaCl, or may be an aqueous solution including 15 wt% NaOH.

In addition, the basic aqueous solution is preferably added at 1.0 to 1.5 molar ratio with respect to 1.0 mole of 1,1,2-trichloroethane. If the amount of the basic aqueous solution is less than 1.0 molar ratio, there is a problem that the conversion of 1,1,2-trichloroethane is reduced, and when the amount of the basic aqueous solution exceeds 1.5 molar ratio, a large amount of by-products are generated.

In addition, when the dechlorination hydrogenation reaction is completed in the present invention, after recovering the vinylidene chloride in the reactor, it is possible to obtain a final product through a purification process.

The purification process of the vinylidene chloride is not particularly limited and may be performed according to methods well known in the art.

According to this method of the present invention, vinylidene chloride having a yield of 90% or more and a purity of 99% or more can be easily obtained.

On the other hand, the process of producing vinylidene chloride in the present invention may be performed taking the process of Figure 2 as an example.

As shown in FIG. 2, in the present invention, two continuous stirred tank reactors 10 having impellers are prepared, and these are connected and installed. In addition, a rectifier 20 may be connected to the reactor 10.

Specifically, in the present invention, 1,1,2-trichloroethane and a basic aqueous solution are supplied to the reactor 10 to proceed with dechlorination hydrogenation. As described above, the dechlorination hydrogenation is a liquid-liquid biphasic reaction in which vinylidene chloride (VDC) is produced in gaseous form by the interfacial reaction kinetics / interfacial area. The resulting vinylidene chloride gas may be stored via top rectifier and liquefaction.

In addition, although the reference numerals are not specifically described in the drawings, the impeller included in the first stage in the reactor is a pitched paddle.

Hereinafter, the present invention will be described in more detail with reference to embodiments according to the present invention. It is to be understood, however, that these embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention.

Comparative Example 1

Into a 0.5L CSTR type reactor, 300 mL of a basic aqueous solution containing 10% by weight of NaOH and 18% by weight of NaCl and 100 g of 1,1,2-trichloroethane were added thereto, and agitated at 339 W / m ³ for 30 minutes. Dehydrochlorination was carried out to produce vinylidene chloride.

[Comparative Examples 2 to 5]

Under the reaction conditions of Comparative Example 1, vinylidene chloride was prepared in the same manner as in Comparative Example 1 except adding the following phase transition catalyst (PTC) corresponding to 3000 ppm of an aqueous alkali solution.

Comparative Example 2: BTBAC, Benzyltributyl ammonium chloride

Comparative Example 3: BTMAC, Benzyltrimethyl ammonium chloride

Comparative Example 4: BTEAC, Benzyltriethyl ammonium chloride

Comparative Example 5: MTOAC, Methyltri-n-octyl ammonium chloride

Example 1

In a 0.5 L CSTR type reactor equipped with a radial rushton turbine (raditon type), 300 mL of basic aqueous solution containing 10 wt% NaOH and 18 wt% NaCl and 100 g of 1,1,2-trichloroethane were added. Vinylidene chloride was prepared by performing dehydrochlorination for 30 minutes after applying a stirring force of 1398 W / m ³ .

At this time, the operating conditions of the continuous stirred tank reactor was maintained at a temperature of 80 ℃ under 1 barg pressure.

[Experimental Example 1]

Comparison of reaction rate according to PTC type and stirring power

The dechlorination reaction rates of Comparative Examples 1 to 5 and Example 1 were measured and the results were compared (FIG. 3).

3, in Comparative Example 1, the reactivity was low due to the low stirring force. In Comparative Examples 2 to 5, the reaction rate increased only by adding PTC at low stirring force.

On the other hand, Example 1 of the present invention by increasing the stirring force to 1398 W / m ³ , it was confirmed that the reaction rate increases even without the addition of PTC.

[Example 2]

Except for increasing the stirring force from 1398 W / m ³ to 2674 W / m ³ , dehydrochlorination was carried out in the same manner as in Example 1 to prepare vinylidene chloride.

[Experimental Example 2]

Comparison of reaction rates by difference in stirring power

For Comparative Example 1 and Examples 1 to 2, the reaction rate according to the stirring force was compared and the results are shown in FIG.

4, it was confirmed that the reaction rate is faster than that of Comparative Example 1 as the stirring power increases as in Examples 1 to 2.

[Examples 3 to 8]

In the continuous stirred tank reactor, an experiment was conducted to determine the reaction pattern according to the impeller type and the conversion rate according to the mixing time.

Reaction conditions: Precipitation conditions of the product are 6 L of basic aqueous solution containing 10% by weight of NaOH and 18% by weight of NaCl (flow rate of 100 ml per minute) and 1.5 L of 1,1,2-trichloroethane (flow rate of 25 ml per minute). To operate a continuous stirred tank reactor at a temperature of 80 ° C. under 1 barg pressure.

Pitched paddle type (Pi), Paddle type (Pa)

Impeller condition rpm P / V
(W / m ³ ) Reaction time Reactant Example 3 Pi / Pi 860 1200 60 minutes NaOH 10% / NaCl18% 6L
(100ml / min)
1,1,2-trichlroethane
1.5L (25ml / min) Example 4 Pa / Pi 680 Example 5 Pi / Pa 710 Example 6 Pa / Pa 640 Example 7 Pi 1020 Example 8 Pa 740

Impeller condition Conversion rate (OH-) Mixing time (s) Example 3 Pi / Pi 87.3% 6.1 Example 4 Pa / Pi 83.1% 30.0 Example 5 Pi / Pa 85.4% 7.2 Example 6 Pa / Pa 85.1% 6.6 Example 7 Pi 87.2% 5.6 Example 8 Pa 83.0% 7.2

In Table 1, the OH-conversions represent the average (maximum standard deviation: 5%) of the 20-60 minute conversions. In addition, the mixing time represents the point at which the concentration standard deviation at any of the three points along the height in the reactor becomes 1e- ⁵ or less.

Through the results in Table 1, Examples 3 to 8 was excellent overall conversion. In addition, the order of the good conversion ratio was Pi / Pi? Pi (Examples 3 and 7)> Pi / Pa? Pa / Pa (Examples 5 and 6)> Pa / Pi? Pa (Examples 4 and 8). From the above results, it can be seen that the reaction conversion rate is high when the pitched paddle type is at the top of one or two stages of the reactor. In addition, embodiments of the present invention can prevent the channeling of the continuous stirred tank reactor, all smoothly vinylidene chloride was moved to the top of the reactor can be easily recovered through a series of processes through the rectifier.

Claims (5)

Adding 1,1,2-trichloroethane and a basic aqueous solution to a continuous stirred tank reactor (CSTR) equipped with an impeller; And
And performing a dechlorination hydrogenation reaction for 1 to 60 minutes at an agitation force (p / v) of 1000 to 3000 W / m ³ .
The impeller in the reactor comprises one or more stages of agitation means selected from the group consisting of paddles and pitched paddles (axial type), the pitched paddles of the reactor At the top of the first or second stage,
Method for preparing vinylidene chloride.
delete The method of claim 1,
The basic aqueous solution is a method of producing vinylidene chloride is a basic aqueous solution containing 2 to 15% by weight of NaOH and 0 to 25% by weight of NaCl.
The method of claim 1, wherein the basic aqueous solution is added at 1.0 to 1.5 molar ratio based on 1.0 mole of 1,1,2-trichloroethane.
The method for preparing vinylidene chloride according to claim 1, wherein the operating conditions of the continuous stirred tank reactor are maintained at a temperature of 70 to 110 ° C under a pressure of 0 barg to 10 barg.

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