JPH02218656A - Production of alkylsulfuric acid ester salt - Google Patents

Abstract

PURPOSE:To obtain an alkylsulfuric acid ester salt suitable for producing high- density granular detergents as a pasty aqueous solution by subjecting an alkylsulfuric acid ester to neutralizing reaction using the alkylsulfuric acid ester and an alkali at a prescribed molar ratio according to a loop method for removing heat. CONSTITUTION:An alkali in an amount of 1-1.2mol is added and mixed with 1mol alkylsulfuric acid ester and neutralizing reaction is continuously carried out by a loop method for removing heat to afford the objective substance. In the process, the alkali (e.g. NaOH) is prepared so as to provide a pasty aqueous solution in 65-75wt.% concentration of the resultant alkylsulfuric acid ester salt after the reaction. The preferred concentration in the aqueous solution of the alkali is 22-37wt.% in this case. The objective substance directly in the pasty state can be efficiently dried with a dryer with a saved space in a drying step following the next step for mixing with other detergent components without requiring conventional spray-drying.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing an alkyl sulfate ester salt, and more particularly to a method for producing an alkyl sulfate ester salt particularly suitable for producing a high-density granular detergent.

[Prior Art] In recent years, demand for high-density granular detergents has increased due to their rationality from a resource-saving perspective and convenience for consumers such as ease of portability. Note that the term "high density" as used herein means that the apparent specific gravity of the powder is 0.5 g/c+j or more.

Typical manufacturing methods for the above-mentioned high-density granular detergents include those disclosed in JP-A-61-64798;
1-66798, JP-A-61-69897, JP-A-61-69898, JP-A-61-698
No. 99, JP-A-61-69900, JP-A-Sho 6
There are methods described in JP-A Nos. 1-76597 and JP-A-61-118500.

[Problem to be solved by the invention]

According to the method described in the above-mentioned publication, it is possible to obtain a high-density granular detergent that is excellent in various respects.
The methods described in JP-A No. 798, JP-A-61-69897, JP-A-61-69898, JP-A-61-69899, and JP-A-61-69900 are as follows:
Both methods involve a spray drying process similar to conventional powder detergent manufacturing methods, which requires large-scale drying equipment and a large amount of drying energy. There is an I.

Also, JP-A-61-66798, JP-A-61-7
The methods described in JP-A No. 6597 and JP-A-118500 do not have a spray drying step, so the problems with the above-mentioned methods have been solved; however, since they both have a crushing step, The crushed material needs to have a hardness above a certain level, and in order to maintain the specified hardness, there is a limit to the amount of moisture derived from the raw material, which poses the problem that the raw materials that can be used are limited.

(!! [Means for Solving the Problem] As a result of various studies on manufacturing methods for high-density granular detergents that can solve the above-mentioned problems, the present inventors found that various interfaces, which are the main raw materials of high-density granular detergents, Among the surfactants, certain surfactants can be obtained at high concentrations by a neutralization method different from conventional methods by utilizing their unique physical properties, and the high viscosity surfactants obtained in this way The agent has a high concentration, and the detergent slurry obtained by mixing with other detergent components in the next step has a low moisture content, which can reduce the drying load. Therefore, it was found that this method of neutralizing a surfactant can be dried by a drying means other than spray drying means and is suitable for producing a high-density granular detergent.

To elaborate on the above findings, since alkyl sulfate salts, which are typical surfactants used in high-density granular detergents, exhibit high viscosity, it is difficult to ensure that the neutralization reaction proceeds smoothly during the production of the salts. , it is necessary to adjust the reaction system to a low viscosity, but since cough salt has poor thermal stability and it is not possible to lower the viscosity by raising the reaction system's temperature, the reaction system must be kept at a low concentration (approximately 40% or less). It was necessary to carry out a neutralization reaction. Therefore, since the neutralized product (alkyl sulfate salt) is obtained at a low concentration, the detergent slurry obtained in the next step has a moisture content of 40 to 55% by weight, and the subsequent drying step requires large-scale equipment. Spray drying methods, which require a large amount of energy, had to be used.

However, the present inventors have discovered that the viscosity curve (graph showing the relationship between viscosity and concentration (Fig. 1)) of the alkyl sulfate ester salt exhibits a minimum value (viscosity) at an aqueous solution concentration of 65 to 75%. When the neutralization reaction is carried out using a loop heat removal method by adjusting the amount (molar ratio) of alkali added to the alkyl sulfate ester within a certain range, the reaction proceeds surprisingly smoothly, and the alkyl sulfate is removed at a high concentration. It was found that a sulfate ester salt can be obtained, and that this high-4 degree salt is extremely suitable for producing high-density granular detergents, and that it can contribute to solving the above problems.

The present invention has been made based on the above findings, and when an alkyl sulfate is neutralized with an alkali to produce an alkyl sulfate salt, 1 to 1.2 moles of alkali are added and mixed to 1 mole of the alkyl sulfate. The present invention provides a method for producing an alkyl sulfate ester salt, which is characterized in that the reaction is carried out continuously by a loop heat removal method to obtain a pasty aqueous solution having a concentration of 65 to 75% by weight.

Hereinafter, the method for producing the alkyl sulfate salt of the present invention having the above characteristics will be described in detail.

The alkyl sulfate esters used in the present invention include aliphatic alcohols having an average carbon number of 10 to 16 produced by reducing triglycerides such as tallow or coconut oil, and sulfuric acid of synthetic alcohols obtained by, for example, oxo synthesis or Ziegler synthesis. It can be manufactured by usually,
Immediately after sulfation, purity 92-98%, free sulfuric acid 0.5-4
%, and the composition of unreacted alcohol is 1 to 4%.

In addition, alkalis used for neutralizing alkyl sulfate esters include sodium hydroxide, potassium hydroxide, ammonium hydroxide, and triethanolamine.
Particularly preferred is sodium hydroxide.

Further, the neutralization reaction in the present invention is carried out by a loop heat removal method, and examples of the loop reactor for carrying out this loop heat removal method include those shown in FIG. As shown in FIG. 2, this loop reactor is equipped with a reaction at for neutralizing an alkyl sulfate and sodium hydroxide, and a loop reaction tube 2 connected to the reactor 1.

The loop tube 2 has one end 2a and the other end 2b connected to the reactor 1 to form a loop.
A pump 3 and a heat exchanger 4 are installed on the upstream side and the downstream side, respectively, and between the pump 3 and the heat exchanger 4, a part of the alkyl sulfate salt, which is a reaction product, is introduced from the loop pipe 2. A branch pipe 5 is formed to be extracted to the next process. Also,
The reactor 1 has a stirrer 111G for stirring and mixing the alkyl sulfate ester, sodium hydroxide, and the circulating alkyl sulfate salt aqueous solution, and the stirring blades 6a of the stirrer 6 are designed to exert high shearing force. and
Normally, it is driven at 1000 to 3000 r, p, m. Incidentally, the arrangement order of the reactor 1 and the pump 3 may be changed depending on the case.

Therefore, when the alkyl sulfate and sodium hydroxide are introduced into the reaction Ill, the stirring fi6 acts to mix the alkyl sulfate and sodium hydroxide to promote the neutralization reaction and produce an alkyl sulfate salt. . At this time, neutralization heat is generated, but a part of the alkyl sulfate salt that has been cooled and removed by the heat exchanger 4 is
Since it is refluxed from the other end 2b of the loop tube 2 to the reaction Ill to suppress the temperature rise due to the heat of neutralization, the alkyl sulfate ester salt is smoothly produced without being thermally decomposed.

The alkyl sulfate ester salt extracted from the branch pipe 5 is fed to a mixer (not shown) in the next step, where it is mixed with other detergent composition components such as Virzo.

To carry out the method for producing an alkyl sulfate salt of the present invention, first, an alkyl sulfate ester and an alkali are supplied to the reactor 1 described above. At that time, the alkali is supplied to the reactor in an amount of 1.0 to 1.2 mol, preferably 1.0 to 1.1 mol, per 1 mol of the alkyl sulfate, and the alkali is added to the reactor after the reaction. The aqueous solution is adjusted to a predetermined concentration so that the concentration of the alkali sulfate ester salt is 65 to 75% by weight. In this case, the preferred concentration of the alkali aqueous solution is 22 to 37% by weight.

1.0 alkali per mole of alkyl sulfate
If it is less than 1.2 mol, the alkyl sulfate and alkyl sulfate salt will be easily decomposed, and if it exceeds 1.2 mol,
The physical properties of the resulting alkyl sulfate ester salt as a surfactant deteriorate or become too hard, making mixing and circulation within the loop reactor L difficult. In addition, when sodium hydroxide is used as the alkali, the amount used is particularly preferably 0 to 1.05 mol per 1 mol of alkyl sulfate.

Furthermore, if the aqueous alkaline solution concentration deviates from the above range, the concentration of the alkyl sulfate ester salt, which is a reaction product, deviates from the above range, and as is clear from FIG. The rapid rise makes stirring difficult, making it difficult to maintain the neutralization reaction.

As mentioned above, when an alkyl sulfate and an alkali are supplied at a predetermined molar ratio and aqueous concentration, a neutralization reaction occurs in the reaction it, and an alkyl sulfate salt is produced, and this alkyl sulfate salt is A state is reached in which the viscosity is near the minimum viscosity value in the high concentration region shown in FIG.

That is, when alkyl sulfate and sodium hydroxide are fed into the reactor 1 at the above molar ratio, a neutralization reaction accompanied by heat proceeds to produce an alkyl sulfate salt, while the reaction ml is heated and cooled. A predetermined amount of the alkyl sulfate salt is refluxed to the reactor 1 to suppress the temperature rise of the reaction mixture and maintain the predetermined temperature, so that the alkyl sulfate salt is smoothly produced without thermal decomposition. The generated alkyl sulfate salt is extracted from the branch pipe 5 and sent to the next step.

The alkyl sulfate salt obtained as described above has a water content of 20 to 33% by weight, which is much lower than the water concentration of the alkyl sulfate salt obtained by the conventional method.

Therefore, in the case of the present invention, the alkyl sulfate ester salt can be used in the next step of mixing with other detergent components (in the drying step, it is not necessary to use spray drying as in the past, but to use other drying methods as a highly viscous paste). Since the drying device can be used for drying, the energy required for drying can be significantly saved, and the installation space for the drying device can be significantly reduced.

〔Example〕

Next, the present invention will be explained with reference to examples.

Example 1 In this example, alkyl sulfate and hydroxide)
An IJum aqueous solution (concentration: 35% by weight) was reacted using the loop reactor L shown in FIG. 1 under the following reaction conditions to obtain the following results. Incidentally, as the alkyl sulfate ester, one having the following composition was used.

Alkyl sulfate ester content −・−・・96% by weight Free sulfuric acid −・・−・・・・～・・−・−・
−・−・・・1.51% by weight unreacted alcohol ・
-...2.5% by weight (sulfation reaction rate 96.3
%) Average number of carbons...13.7 (1) Reaction conditions ■Supply amount x circulation ratio -...30 (j!/hr) x20
Times ■Number of moles of sodium hydroxide per mole of alkyl sulfate ・・・・・・・・・ 1.05 mol ■Reaction temperature ・・・・・・・・−・−・・65-75℃■
pH・-・・11.3 (2) Results ■Alkyl sulfate salt concentration・−・74% by weight■
Total reaction rate from sulfation to neutralization -96%
■Water content after reaction ・−・−・−・・・・・−・・−2
3% by weight ■ Viscosity at 70°C...500
0c, p.

0 Hue ......-20 to 30 (10% by weight aqueous solution; 1ette%) Examples 2 and 3 Using the same equipment and raw materials as Example 1, the reaction conditions were changed to the first
Neutralization reactions were carried out with changes as shown in the table.

Comparative Example 1 Using the same equipment and the same raw materials as Example 1, the reaction conditions were changed to the first
Neutralization reactions were carried out with changes as shown in the table.

That is, the neutralization reaction was performed with a different circulation ratio compared to Example 1.2.

Comparative Example 2 Using the same equipment and the same raw materials as Example 1, the reaction conditions were changed to the first
Neutralization reactions were carried out with changes as shown in the table.

That is, the neutralization reaction was performed by adding an excess of sodium hydroxide compared to Examples 1 to 3.

According to Table 1 showing the results of the neutralization reactions in Examples 1 to 3 and Comparative Examples 1.2 above, in Comparative Example 1, Example 1.
Because the circulation ratio was smaller than in Comparative Example 2, the reaction temperature increased, the reaction rate decreased due to thermal decomposition, and the hue of the neutralized product worsened. In addition, in Comparative Example 2, the amount of sodium hydroxide supplied was excessive. It can be seen that the viscosity of the neutralized product increases, making stable operation impossible.

That is, based on the method of the present invention (in Examples 1 to 3), the water content in the product was low, the viscosity was in the minimum range in the graph of FIG. 1, and the neutralization reaction was facilitated by the loop reactor. It turns out that it is possible to proceed.

Activator Concentration (%) [Effects of the Invention] According to the present invention, an alkyl sulfate ester salt suitable for producing a high-density granular detergent can be efficiently produced with a low water content, and this alkyl sulfate salt can be efficiently produced with a low water content. The ester salt is in the form of a paste, and in the drying process that follows the mixing process with other detergent ingredients in the next process, it can be efficiently dried using space-saving drying equipment without using conventional spray drying. .

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the aqueous solution concentration and viscosity of an alkyl sulfate salt, and FIG. 2 is a configuration diagram showing a loop reactor suitable for carrying out the method for producing an alkyl sulfate salt of the present invention. Procedural amendment 1. Display of the case Japanese Patent Application No. 1-41115 2, Name of the invention Process for producing alkyl sulfate ester salt 3, Person making the amendment Relationship to the case Patent applicant (091) Kao Corporation 4, Agent Minami-Aoyama, Minato-ku, Tokyo - Voluntary amendment to the 8th floor of Yamashiro Building, 15-16 Chome (amendment made within 1 year and 3 months from the date of application). 6. Detailed description of the invention and drawings in the specification to be amended. 7. Contents of correction (1) “Energy” in line 7 of page 3 has been corrected to “energy.” (2) “To keep” on page 3, line 15 has been corrected to “to keep.” (3) On page 4, line 2, "About surfactants" was corrected to "About surfactants." (4) Corrected “areru detergent” in line 7 of page 4 to “areru detergent.” (5) "Pump 3 and heat exchanger 4" on page 7, lines 12 to 13 was corrected to "reactor 1 and heat exchanger 4." (6) "Agitator 6... shearing force" on page 7, lines 18 to 19 was corrected to "It has a stirring blade 6, and this stirring blade 6 has high shearing force and dispersion force." (7) “Builder” in page 8, line 16 was corrected to “builder”. (8) On page 11, line 12, after “I will explain.”
The present invention is not limited to these examples in any way.'' (9) rKIe rKletteJ on page 12, line 17
tJ and correction. 00) "Sulfation" in the third line from the bottom of page 15 was corrected to "total reaction rate from sulfation to neutralization." 00 15th line 2nd row from just below rlO%” to “10% by weight”
” and corrected. +12) In the first line from the bottom of No. 15, "'# Circulation is not possible, operation is not possible" is corrected to "Circulation is not possible, operation is not possible." ■Figure 2 has been corrected as attached. that's all

Claims (3)

[Claims] (1) When producing an alkyl sulfate ester salt by neutralizing the alkyl sulfate ester with an alkali, 1 to 1.2 mol of alkali is added and mixed to 1 mol of the alkyl sulfate ester, and continuously by a loop heat removal method. 1. A method for producing an alkyl sulfate ester salt, which comprises reacting the alkyl sulfate ester salt to obtain a pasty aqueous solution having a concentration of 65 to 75% by weight. (2) The method for producing an alkyl sulfate ester salt according to claim (1), wherein the alkyl group of the alkyl sulfate ester has an average carbon number of 10 to 16. (3) Claim (1) wherein the circulation ratio of the aqueous solution of the alkyl sulfate salt in the loop heat removal method is 10 to 50 times.
) or the method for producing an alkyl sulfate ester salt according to (2).