JPH0425943B2 - - Google Patents

Description

[Detailed description of the invention]

Technical Field The present invention relates to a continuous method for sulfating organic compounds using chlorosulfonic acid. Prior Art Sulfation using chlorosulfonic acid has the advantage that unstable organic compounds are less likely to be decomposed because chlorosulfonic acid has milder reactivity than sulfuric anhydride. However, when trying to implement this on an industrial scale, there are actually various problems. Conventionally, industrial sulfation reactions using chlorosulfonic acid have been carried out batchwise, in which chlorosulfonic acid is added to the organic compound while stirring it in a tank. There are problems like this. Since chlorosulfonic acid is added dropwise or introduced into the liquid while stirring the organic compound, chlorosulfonic acid is unevenly distributed and becomes partially excessive. Bubbles of by-product chlorine gas cover the surface of the reaction mixture, and as a result, the dropped chlorosulfonic acid floats on the surface, requiring time to mix uniformly. Hydrogen chloride gas is entangled in the reaction mixture, increasing its viscosity and resulting in insufficient stirring, which not only takes a long time to complete the reaction, but also makes the reaction heat less effective to remove. It takes a long time from the start of sulfation to the end of neutralization,
The residence time of the product sulfate ester becomes longer. A large amount of hydrogen chloride gas is dissolved in the obtained sulfuric ester. These causes cause side reactions such as overreaction between organic compounds and chlorosulfonic acid and decomposition reaction of sulfuric esters. Therefore, the quality of the obtained sulfate or its neutralized product is currently inferior to that of products obtained by the anhydrous sulfuric acid method, as it contains many unreacted organic compounds, by-products such as mirabilite and salt. . For example, neutralized salts of sulfates such as higher alcohols and polyoxyethylene higher alkyl ethers are used as anionic surfactants in raw materials for liquid detergents, shampoos, toothpastes, etc., but conventional chlorsulfonic acid The neutralized salt obtained by this method is inferior in terms of viscosity, freezing point, low-temperature stability, flavor, etc., and requires special ingenuity in the formulation, which greatly limits its use. Purpose of the Invention The present invention uses chlorosulfonic acid to reduce impurities such as unreacted oil, mirabilite, and salt, and
The purpose of the present invention is to provide a method for producing high-quality sulfides with good color and odor. Purpose of the Invention The continuous sulfation method of the present invention includes forming a high-speed gas flow along a wall surface and supplying an organic compound onto the wall surface to form a fluid thin film of the organic compound on the wall surface by the high-speed gas flow, The method is characterized by bringing this fluid thin film into contact with chlorosulfonic acid. The present invention will be explained in more detail below. In the present invention, first, a forced flow thin film of a raw material organic compound flowing along a wall surface is formed by a high-speed gas flow. For example, by introducing an inert gas such as nitrogen or air as a high-speed flow into a circular tube, and supplying the organic compound as a liquid by heating it if necessary, the organic compound is forced into a thin film on the inner wall of the circular tube. It flows in a shape. Chlorosulfonic acid is then sprayed onto this fluidized film and added as fine particles. Spraying of chlorsulfonic acid can be carried out, for example, by continuously introducing chlorsulfonic acid into a high-speed stream of inert gas and ejecting it from pores. May be squirted directly. Since chlorosulfonic acid is atomized in a space in which a high-speed gas flow flows, the gas flow further atomizes the chlorsulfonic acid into fine particles, making it possible to uniformly add it to the organic compound at any time. The amount of chlorosulfonic acid added is the theoretical amount required for sulfuric acid esterification of an organic compound (1 mole if the molecule has one hydroxyl group).
Approximately 1.00 to 1.05 times the amount is appropriate. In the present invention, since the organic compound reacts in the form of a thin film, the heat exchange efficiency is high, and the chlorosulfonic acid necessary for the reaction can be sprayed all at once, but it may be sprayed multiple times if necessary, such as when increasing the production scale. It can also be added in portions. Since the chlorosulfonic acid is thus absorbed as fine particles in contact with the organic compound liquid film, there is no disturbance of the liquid film at the point of contact. The heat of reaction between the organic compound and chlorosulfonic acid is exchanged through the wall surface. In addition, the hydrogen chloride gas generated by the reaction is instantaneously broken and diffused by the high-speed gas flow, so the hydrogen chloride gas stays on the surface of the organic compound liquid film and prevents contact with the chlorosulfonic acid. Raw hydrogen chloride gas can be prevented from being entrained in the reaction mixture. From the viewpoint of promoting the bursting of bubbles by hydrogen chloride gas, and also improving the stirring effect of the reaction mixture and heat exchange efficiency and smoothing the reaction, the high-speed gas flow is
It is preferable to set it to m/sec or more. Furthermore, if the speed is too high, it will turn into mist, resulting in lower yields and higher equipment costs, so a range of 80 m/sec or less is appropriate. The reaction mixture produced by adding chlorosulfonic acid to the organic compound in the form of a thin film continues to be kept in a fluid state, and is moved and stirred in the form of a thin film by a high-speed gas flow to mature and complete the reaction. 20～80m/sec
By moving and stirring using a high-speed gas flow, the frequency of molecular collisions between unreacted organic compounds and chlorosulfonic acid can be increased, and the reaction can be completed in a short time. The melting point of the reaction mixture fluctuates as the sulfuric acid esterification progresses from the addition of chlorosulfonic acid to ripening. The reaction and aging temperatures are preferably lower from the viewpoint of controlling overreaction and decomposition reactions, but on the other hand, it is necessary to maintain the reaction mixture in a sufficiently fluid state. Therefore, it is preferable to control the heat exchange through the wall surface according to the progress of the reaction, and it is appropriate to set the reaction temperature to a value higher than the melting point of the flowing reaction mixture and lower than the melting point +10°C. More preferably, the melting point is +5°C or lower. From the addition of chlorosulfonic acid to the completion of the reaction,
That is, the reaction time until the completion of ripening is suitably 0.5 to 5 minutes, preferably 1 to 3 minutes.
If the reaction time is too short, the esterification reaction will not proceed sufficiently, and if the reaction time is too long, the decomposition of the produced sulfuric ester will proceed, which is not preferable. Next, the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is a diagram showing an example of the configuration of an apparatus for implementing the present invention. Heat exchange jackets 13, 15 and 41 are provided around the outer periphery of the reaction tube 11, and a high speed gas introduction port 17 and a raw material supply port 19 are provided at the upper part. A high-speed gas flow is guided into the reaction tube 11 from the high-speed gas inlet 17 to form a downward flow, while the organic compound in a liquid state is led from the raw flow supply port 19 to an annular storage tank 21 where it is The gas overflows and flows from the raw material introduction gate 23 along the inner wall of the reaction tube, forming an annular falling thin film flow due to the high-speed gas flow. Chlorsulfonic acid is introduced from the chlorsulfonic acid supply port 31, introduced from the gas introduction port 33, and then sprayed with an inert gas into the spray nozzle 3.
It is sprayed from the tip of No. 5, and the reaction with the organic compound is started. The sprayed chlorsulfonic acid particles are
The particles are further atomized by the high-speed gas flow from the high-speed gas inlet 17. The reaction mixture obtained by spraying chlorosulfonic acid on organic compounds is
It moves from the reaction zone 37 in a thin film state while being further stirred, passes through the ripening zone 39, and then enters the cyclone 51.
The sulfuric acid ester is separated into the generated sulfuric ester and waste gas. The obtained sulfate ester is continuously neutralized to obtain a sulfate ester salt. The reaction tube 11 has a plurality of heat exchange jackets 13,1
It has 5,41. Heat exchange jacket 13, 15
In the section equipped with , absorption and reaction of the sprayed chlorosulfonic acid into organic compounds mainly takes place, forming a reaction zone 37 . On the other hand, the latter part surrounded by the heat exchange jacket 41 forms a ripening zone 41 where the reaction between unreacted organic compounds and chlorosulfonic acid occurs mainly in the thin film and the reaction is completed. By dividing and controlling the heat exchange jacket into multiple parts in this way, fluidity can be maintained without impairing the movement and stirring of the reaction mixture through a thin film, in response to changes in the melting point and reaction heat due to the progress of the reaction. It is appropriate to control the temperature as low as possible within the range and to control overreaction and decomposition reactions. Also, as mentioned above, the residence time in the reaction tube is
The time is 0.5 to 5 minutes, preferably 1 to 3 minutes. The smaller the diameter of the reaction tube, the better the heat exchange efficiency.
In addition, although it is possible to prevent the liquid film from becoming a mist due to disturbance, it is appropriate to set the thickness to 2 to 50 mm, preferably 4 to 30 mm, taking production capacity and other aspects into consideration. Although the reaction tube may be a straight tube as shown in FIG. 1, it is preferably a column-shaped or spiral-shaped curved tube. By using such a curved pipe, it is possible to improve the stirring efficiency, make the residence time uniform, and make the equipment more compact. Since a high-speed gas flow is used, even if the reaction tube is a curved tube, the film does not break, and the liquid film can be moved while maintaining its annular shape. Organic compounds that can be sulfated by the method of the present invention include straight-chain or branched-chain alcohols having 8 to 20 carbon atoms or mixtures thereof, alkylene oxide adducts of alcohols, alkyphenols, or fatty acids;
Examples include fatty acid alkylolamides having 10 to 20 carbon atoms, ethylene oxide adducts thereof, and unsaturated hydrocarbon compounds. Neutralized salts of these compounds are excellent anionic surfactants. Effects of the Invention According to the present invention, by bringing the organic compound formed into a fluidized thin film into contact with chlorosulfonic acid using a high-speed gas flow, it is possible to continuously sulfate the organic compound, and also to sulfate the organic compound into the organic compound. Uneven distribution of chlorosulfonic acid is prevented, and heat exchange efficiency is also high. Furthermore, bubbles caused by by-product hydrogen chloride gas are simultaneously broken and diffused, preventing an increase in the viscosity of the sulfuric acid ester due to bubble entrainment and preventing chlorosulfonic acid from adhering to the bubbles, thereby improving stirring efficiency and heat exchange efficiency. At the same time, the amount of dissolved hydrogen chloride also decreases. Therefore, the reaction is completed in a short time and mildly, over-reaction and decomposition reactions are controlled, and a sulfated product with less unreacted organic compounds and by-products can be obtained. This neutralized product of sulfates contains less impurities such as unreacted organic compounds, mirabilite, and common salt, and has excellent color tone and odor, and is widely used as an anionic surfactant. Applications of this sulfide or its neutralized salt include, for example, raw materials for household products such as liquid detergents, shampoos, and foaming agents for toothpaste, as well as emulsifiers for emulsion polymerization, emulsifying and dispersing agents for pharmaceuticals, emulsifying agents for agricultural chemicals, and pigments. It is suitable as an industrial raw material for emulsifying dispersants, foaming agents for ore flotation, foaming agents for gypsum boards, air entrainment agents for cement mortar, etc. Example Using the reaction apparatus shown in FIG. 1, various organic compounds shown in Table 1 below were forced into a thin film with nitrogen gas, and 1.00 to 1.05 equivalents of chlorosulfonic acid was sprayed to 1 equivalent of the organic compound. The product was sulfated under the reaction conditions shown in Table 1, and then neutralized with caustic soda to obtain a neutralized salt. Table 1 shows the properties of this neutralized salt.

[Table] Reference example Meanwhile, while stirring the organic compounds shown in Table 2 below, the same amount of chlorosulfonic acid as in the example was added dropwise, and the reactions were carried out at the aging temperature shown in Table 2. The resulting sulfate was neutralized in the same manner as in Examples, and the properties of the resulting neutralized salt are shown in Table 2.

【table】 [Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of the configuration of an apparatus used to carry out the present invention. 11... Reaction tube, 13, 15, 41... Heat exchange jacket, 17... High speed gas inlet, 19...
Raw material supply port, 23... Raw material introduction gate, 31...
Chlorsulfonic acid supply port.

Claims (1)

[Claims] 1. Forming a high-speed gas flow along a wall surface and supplying an organic compound onto the wall surface to form a fluid thin film of the organic compound on the wall surface by the high-speed gas flow,
A continuous sulfation method characterized by bringing this thin film-like organic compound into contact with chlorosulfonic acid.