JPH0377182B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an aqueous olefin sulfonate slurry, and in particular to a method capable of producing a highly concentrated slurry. Olefin sulfonate is useful as a surfactant used in detergents, shampoos, cosmetics, etc., and has excellent biodegradability and hard water resistance. Olefin sulfonate is produced by sulfonating the raw material olefin to obtain a mixture of alkenesulfonic acid and sultone, which is then neutralized by adding water and an alkaline agent and hydrolyzed. Alkenesulfonate and hydroxyalkanesulfonic acid It is a mixture with salt and is obtained in the form of an aqueous slurry. As described above, since olefin sulfonates contain water-insoluble sultones, a step is required to hydrolyze the sultones and convert them into hydroxyalconesulfonates and alkenesulfonates that have surface-active properties. The slurry was neutralized at a relatively low temperature to form an aqueous slurry, and then hydrolyzed at a high temperature. However, when the concentration of olefin sulfonate in the aqueous slurry is increased, the viscosity of the aqueous slurry increases after the start of neutralization, making neutralization itself difficult and transportation to the hydrolysis process difficult. There are also problems in that the hydrolysis operation becomes difficult, and there is a limit to increasing the concentration of the olefin sulfonate aqueous slurry. On the other hand, increasing the concentration of slurry reduces storage and transportation costs, and also saves energy when evaporating water, as in the production of heavy-duty laundry detergents. is requested. As a method for producing a high-concentration olefin sulfonate slurry, Japanese Patent Application Laid-Open No. 78828/1983 discloses adding an excess of an alkaline agent and an alkylene oxide derivative to form a slurry with a concentration of about 50%. However, this method requires additives, and when the concentration exceeds about 60%, excess alkaline agents actually exhibit a thickening effect. In addition, JP-A No. 58-157758 discloses that polyethylene glycol or polyoxyethylene alkyl ether and aromatic carboxylic acid are added to neutralize and hydrolyze to form a highly concentrated aqueous olefin sulfonate with a concentration of 60% or more. A method for producing slurry has been reported. However, since additives are required, the cost not only increases, but also, depending on the application, they become impurities, which limits their use. From the above viewpoint, the present inventors have conducted intensive studies on a method that can suppress the increase in viscosity after neutralization without using additives and obtain a highly concentrated olefin sulfonate aqueous slurry. By skillfully controlling the neutralization-hydrolysis process,
We have discovered that this is possible, and have completed the present invention based on this knowledge. That is, in the method for producing an aqueous slurry of olefin sulfonate of the present invention, when producing an aqueous slurry of olefin sulfonate by neutralizing and hydrolyzing a sulfonated product of olefin, the amount of sultone is 0.5 to 0.5 to 1 per olefin sulfonate. It is characterized in that the sulfonated product of olefin is neutralized and hydrolyzed at 100 to 140°C using an alkaline agent so that the concentration becomes 4% by weight, and then hydrolyzed at 150 to 200°C. The present invention will be explained in more detail below. The sulfonated product of olefin is obtained by sulfonating the raw material olefin by a conventional method,
Thin film sulfonation methods are preferred. As a sulfonating agent, anhydrous SO ₃ or SO ₃ gas converted with a V ₂ O ₅ catalyst is _mixed with nitrogen or dry air for 1 to 3 hours.
A diluted product of 15 vol% is used at an SO ₃ molar ratio of 1.0 to 1.1, and the sulfonated product is usually obtained in a yield of 95% or more. Further, as the raw material olefin, a linear or branched olefin having 10 to 20 carbon atoms is used, and both α-olefin and inner olefin can be used. The sulfonated product thus obtained contains an alkene sulfonic acid and a sultone, and usually contains about 40 to 65% sultone. This sulfonated product is first subjected to a neutralization-hydrolysis treatment at 100 to 140°C. The neutralization-hydrolysis treatment is carried out by mixing the sulfonated product with water and an alkaline agent, and is usually mixed as an aqueous solution of the alkaline agent. It is preferable to mix the two quickly in a short period of time.
It is preferable to carry out pipe mixing by using the above in-line mixer. In order to obtain a highly concentrated slurry, it is preferable that the water content of the alkaline agent aqueous solution is not high, and since an alkali agent aqueous solution of 20 to 50 wt% is usually used, if the mixing of the two is uneven, there may be a localized high alkaline solution. This is not preferable because the neutralized product may be agglomerated and solidified due to its strong salting-out effect, or may be colored by locally remaining sulfonic acid. From this point of view, the sulfonated product and alkaline agent mixed in a mixer such as an in-line mixer are circulated back into the mixer by a circulation loop, and a buffer for the sulfonated product and alkaline agent newly supplied to the mixer is used. It is better to use it as a diluent. The amount of circulation is suitably at least 3 times, preferably at least 5 times, the amount of the sulfonated product and alkaline agent supplied. The neutralized-hydrolyzed slurry is taken out from the loop and sent to the next high-temperature hydrolysis step. In the neutralization-hydrolysis step, the alkene sulfonic acid forms a salt, and the sultone is hydrolyzed to open the ring and then neutralized to form a hydroxyalkanesulfonate and an alkene sulfonate. In the present invention, neutralization-hydrolysis is carried out at 100-140°C, preferably
The reaction is carried out at 110 to 130°C so that the amount of sultone is 0.5 to 4% by weight based on the olefin sulfonate. If the temperature is less than 100°C, it will take a very long time to achieve the above-mentioned amount of saltone, and if it exceeds 140°C, the resulting neutralized product will be colored and smell, which is not preferable. Furthermore, if the amount of sultone exceeds the above range, the viscosity of the neutralized product will increase significantly, while strict conditions are required to reduce it to less than 0.5 wt%, leading to coloration of the neutralized product. Neutralization-hydrolysis treatment time is 5-60
minutes is appropriate, preferably 10 to 50 minutes. The alkaline agent is preferably added so that it remains in an amount of 0.1 to 3 wt% based on the olefin sulfonate after the neutralization-hydrolysis treatment. If the amount of residual alkali is too large, the viscosity of the slurry increases, which is not preferable. As the alkali agent, hydroxides and oxides of alkali metals such as sodium hydroxide and potassium hydroxide are used. Water may be added as necessary, and is adjusted at appropriate times so as to obtain an aqueous slurry containing 55 to 80 wt% of olefin sulfonate. The neutralized-hydrolyzed slurry obtained as described above has a low viscosity and is easy to handle. Therefore, even when this is hydrolyzed at high temperatures, there is no burning or strange odor caused by partial heating, and transportation and
Stirring is also easy, and it is particularly suitable for continuous hydrolysis using a piping system. High temperature hydrolysis is 150-200℃, preferably 160℃
It is carried out at ~180°C and takes 20 to 60 minutes. As the device, a normal double-tube hydrolyzer or the like can be used. This treatment hydrolyzes the remaining sultone and yields an aqueous slurry containing a high concentration of olefin sulfonate. According to the present invention, by controlling the neutralization and hydrolysis conditions, an olefin sulfonate aqueous slurry can be produced while suppressing an increase in viscosity after neutralization. Therefore, it is possible to increase the concentration of the slurry using a continuous device with high productivity, and it is suitable for producing a highly concentrated slurry containing 55 to 80 wt% of olefin sulfonate. Further, since no additives are required, the cost does not increase, and the resulting slurry does not contain unnecessary substances and is highly versatile. Example 1 _C14-18 α-olefin ( _C14 : 15% _{, C16} :
50%, C ₁₈ : 35%, average molecular weight: 229) was sulfonated with diluted SO 3 at a molar ratio of olefin SO ₃ to olefin SO ₃ of 1.05 using a thin film sulfonation apparatus.
- A sulfonation reaction product of olefin was obtained (reaction rate of olefin: 96 wt%). Then neutralization with mixer and circulation loop
Using a hydrolysis device, supplying the above-mentioned sulfonation reaction product and alkali agent aqueous solution to this mixer,
While recirculating 5 to 10 times the amount of the mixture, neutralization-hydrolysis was carried out at the neutralization-hydrolysis temperature and average residence time shown in Table 1 to obtain a predetermined amount of saltone and remaining amount of alkaline agent. The viscosity of this neutralized hydrolyzate is shown in Table 1. Next, this neutralized-hydrolyzate was supplied to a double-tube hydrolyzer using a high-pressure metering pump, and heated to 165°C.
The mixture was hydrolyzed at high temperature for 20 minutes to obtain an olefin sulfonate slurry. The properties of this slurry are
Shown in the table. 【table】

Claims (1)

[Claims] 1. When neutralizing and hydrolyzing the sulfonated product of olefin to produce an aqueous slurry of olefin sulfonate, the amount of sultone is 0.5 to 4% by weight based on the olefin sulfonate, using an alkaline agent to 100-140 sulfonates
A method for producing an aqueous olefin sulfonate slurry, which comprises neutralizing and hydrolyzing at 150 to 200°C.