JP3164747B2 - Continuous dilution method of anionic surfactant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously diluting an anionic surfactant used in dishwashing detergents, shampoos, clothing detergents and the like. The present invention relates to a method for efficiently and continuously diluting an anionic surfactant which cannot be efficiently performed by a simple operation.

[0002]

2. Description of the Related Art Conventionally, there have been many methods of supplying a high-viscosity fluid and a low-viscosity fluid from separate pipes, joining the two fluids, and then continuously mixing them with a line mixer or the like. Are being considered.

For example, JP-A-64-34427 discloses a first pipe provided with a first pump for pumping a high-viscosity fluid and a second pipe provided with a second pump for pumping a low-viscosity fluid. A line mixer is provided in a third pipe for connecting and connecting the high-viscosity fluid and the low-viscosity fluid to deliver the high-viscosity fluid and the low-viscosity fluid. A method of mixing different viscosity fluids is disclosed in which a premixing of a viscosity fluid is performed and a valve provided in each pipe is opened and closed simultaneously with the operation and stop of a pump.

[0004] However, the line mixer used here is considered to mean a static in-pipe mixer such as a static mixer. Since the shear rate and the shearing force during stirring are small, high-viscosity fluids and low The fact is that it cannot be applied to a system in which the viscosity becomes extremely large when a viscous fluid is mixed.

[0005] On the other hand, there have been studied several methods for atomizing a cationic surfactant, which is liable to be thickened by contact with water, into water by a method similar to the above method in which the stirring power is further increased.

For example, Japanese Patent Application Laid-Open No. 57-102226 discloses that a line mixer provided with a stirring blade is provided in a pipe for supplying water, and a line mixer is provided upstream of the line mixer at a position close to the stirring blade. There has been disclosed a method for continuously atomizing a cationic surfactant, which comprises continuously supplying a cationic surfactant and involving the same in the stirring blade to continuously atomize the cationic surfactant.

As an improvement method, Japanese Patent Laid-Open No. 1-2
In Japanese Patent No. 49129, a line mixer provided with a stirring blade is provided in a pipe for supplying a quaternary ammonium salt, and water is continuously supplied into the pipe at a position on the upstream side near the stirring blade. A method of continuously producing a soft finish by adding stirring and shearing is disclosed,
The effect that the number of rotations of the line mixer is smaller than that of the above method is obtained.

However, these methods can make the cationic surfactant finer, that is, improve the dispersibility, and have a different mechanism from the dilution of the anionic surfactant. To the viscosity before dilution of 10
It was inconceivable to those skilled in the art that these methods are equally applicable to anionic surfactants having more than twice the viscosity maximum.

Conventionally, as a method of diluting an anionic surfactant, a time-consuming operation of gradually diluting the mixture while stirring it at a high temperature by a batch operation and then cooling is performed.

[0010] An object of the present invention is to solve such a problem by preparing an anionic surfactant having a maximum value of viscosity at least 10 times the viscosity before dilution when diluted with water or the like by a simple operation. It is an object of the present invention to provide a method for diluting efficiently and continuously obtaining a diluent having good appearance.

[0011]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that the viscosity has a maximum value due to a decrease in the dilution concentration, and the maximum value is one of the viscosity before dilution.
When diluting the anionic surfactant so as to be 0 times or more, in order to improve the method of the above publication, using a continuous hermetic mixer equipped with a mixing chamber independent of piping and a stirring blade inside the mixing chamber, By supplying the high-viscosity fluid and the low-viscosity fluid so that the average residence time during which the fluid stays in the mixing chamber becomes large, the average moving distance obtained by multiplying the peripheral speed of the continuous closed type mixer by the average residence time is obtained. It was found that by setting the dilution to a larger value, it was possible to simply obtain a diluted product having a good appearance, thereby completing the present invention.

That is, the gist of the present invention is as follows: (1) A high-viscosity fluid and a low-viscosity fluid are supplied from separate pipes to join them, and then mixed by a mixer provided downstream thereof to obtain a high-viscosity fluid. In the method of continuously diluting a fluid, the high-viscosity fluid is a liquid containing an anionic surfactant as a main component, the low-viscosity fluid is an aqueous solvent, and the relationship between the two is a low-viscosity fluid and a high-viscosity fluid. When the fluid is gradually diluted at a constant temperature and shows a maximum value of the viscosity, and the maximum value is 10 times or more the viscosity of the high-viscosity fluid before dilution,
The mixer is a continuous hermetic mixer having a mixing chamber independent of the piping and a stirring blade therein, and has a high viscosity so that the average residence time of the mixed fluid in the mixing chamber is 4 seconds or more. A method for continuously diluting an anionic surfactant, which comprises supplying a fluid and a low-viscosity fluid; (2) providing a single internal nozzle upstream of the stirring blade to supply a high-viscosity fluid from the nozzle and an average residence time; (1) The average moving distance obtained by multiplying the time by the peripheral speed of the stirring blade is 200 m or more.
(3) A plurality of internal nozzles are provided upstream of the stirring blade to supply a high-viscosity fluid therefrom, and the average moving distance obtained by multiplying the average residence time by the peripheral speed of the stirring blade is 100 m. The continuous dilution method according to the above (1), wherein the anionic surfactant is an alkyl sulfate or a polyoxyethylene alkyl ether sulfate represented by the following general formula (I). To (3), wherein RO is a linear or branched alkyl or alkenyl group having 8 to 22 carbon atoms; and RO (CH ₂ CH ₂ O) _n SO ₃ M (I) And _n is 0 or 1 to 1
0 represents M, and M represents Na, K, NH ₄ or triethanolamine. (5) The continuous method according to the above (4), wherein the concentration of the anionic surfactant in the high-viscosity fluid before dilution is 55 to 80% by weight, and the concentration of the anionic surfactant in the liquid after dilution is 15 to 35% by weight. Dilution method.

The raw material to be subjected to the continuous dilution method of the present invention is a high-viscosity fluid containing an anionic surfactant as a main component, and when a low-viscosity fluid is gradually diluted at a constant temperature, the viscosity has a maximum value. As shown, the maximum value is usually 10 times or more, particularly 50 times or more, more specifically 100 times or more, of the viscosity of the high-viscosity fluid before dilution (particularly, the minimum value of the viscosity before dilution). Such anionic surfactants include, specifically, various anionic surfactants having a viscosity profile as shown in FIG.

[0014] Examples of such anionic surfactants include alkyl sulfates and polyoxyethylene alkyl ether sulfates.

Among them, alkyl sulfates or polyoxyethylene alkyl ether sulfates represented by the following general formula (I) have a maximum value of viscosity and the effect of the present invention is remarkable. RO (CH ₂ CH ₂ O) _n SO ₃ M (I) (wherein, R represents a linear or branched alkyl or alkenyl group having 8 to 22 carbon atoms, and _n represents 0 or 1 to 1)
0 represents M, and M represents Na, K, NH ₄ or triethanolamine. )

In the general formula (I), examples of R include an alkyl group such as octyl, lauryl, myristyl, palmityl, stearyl, and behenyl, and an alkenyl group corresponding thereto.

Specific examples of the compound represented by the general formula (I) include sodium lauryl sulfate, polyoxyethylene (2) sodium lauryl ether sulfate, polyoxyethylene (3) sodium lauryl ether sulfate, and sodium salts thereof. Similarly, ammonium salts, triethanolamine salts, or potassium salts may be mentioned.

The components other than the anionic surfactant contained in the high-viscosity fluid include water, a viscosity reducing agent (ethanol, propylene glycol, glycerin and the like).
There is no particular limitation.

According to the continuous dilution method of the present invention, the concentration of the anionic surfactant in the high-viscosity fluid before dilution is 55 to 80% by weight, and the concentration of the anionic surfactant in the liquid after dilution is 15 to 3%.
It is preferable to be 5% by weight in view of the remarkable effect. That is, since the concentration of the anionic surfactant obtained by the ordinary synthesis method is usually 55 to 80% by weight, the reaction solution can be used as it is in the present invention.
Since 5 wt% has a high viscosity region, it is necessary to mix for a long time in order to pass through the high viscosity region in ordinary dilution, whereas in the present invention, it is necessary to instantaneously pass through the high viscosity region for 15 minutes. This is because it can be diluted in a short time to a low viscosity region of about 35% by weight.

The water-based solvent used as the low-viscosity fluid in the present invention includes water or a solvent containing water as a main component.
Thickening agents such as ethanol, propylene glycol, glycerin and the like can be used. In the present invention, it is particularly preferable to use a mixed solution of water and alcohol as the aqueous solvent, for example, because the stirring force can be reduced.

As the apparatus used in the continuous dilution method of the present invention, a high-viscosity fluid and a low-viscosity fluid are supplied from separate pipes to join them, and then mixed by a mixer provided downstream thereof. A mixer capable of continuously diluting a high-viscosity fluid, wherein the mixer is a continuous hermetic mixer having a mixing chamber independent of piping and a stirring blade therein. Specific examples of continuous closed mixers include line homomixers, line mills, milders,
A pump having such a structure is appropriately selected from a centrifugal pump or the like.

In particular, as shown in FIG. 2, a mixing chamber independent of the piping and a stirring blade therein are provided, and a single or a plurality of internal nozzles are provided upstream of the mixing chamber at a position close to the stirring blade. A continuous hermetic mixer having a structure having internal piping is preferred. Here, the mixing chamber refers to a space inside the vessel connected to the pipe and where mixing is performed by the stirring blade (part separated by a dotted line in the figure). Means that a stirring blade is provided inside. Note that the position close to the stirring blade means that the distance between the stirring blade and the pipe outlet is １ ／ of the stirring blade diameter.
It means the following. Further, the number of stirring blades can be increased, or a continuous hermetic mixer can be connected in series.

In the above, the single or plural internal nozzles may be those in which nozzles are attached to internal pipes, those which are simply pipes as they are, or those in which a plurality of outlets are provided at the tip. However, in order to prevent a short path and dilute more efficiently, it is preferable to provide a plurality of nozzles in the internal piping (see FIG. 3).

The operating conditions are preferably such that a high-viscosity fluid and a low-viscosity fluid are supplied so that the average residence time of the mixed fluid in the mixing chamber is at least 4 seconds, more preferably 10 to 30. Seconds. In the present invention, by increasing the average residence time in this way, the average travel distance obtained by multiplying the average residence time by the peripheral speed of the stirring blade can be increased, and the stirring efficiency can be improved.

The average residence time referred to in the present invention is as follows: the supply amount of the high-viscosity fluid is A / min, the supply amount of the low-viscosity fluid is B / min, and the volume of the mixing chamber of the continuous hermetic mixer is L / min.
If it is liter, it can be obtained by the following equation. Average residence time = L / (A + B) Accordingly, the average residence time can be adjusted as described above by adjusting the total supply amount of the fluid and by adjusting the size of the mixing chamber volume L. The low-viscosity fluid at this time is water that does not contain a viscosity reducing agent. In addition, needless to say, by adding a viscosity reducing agent to the low-viscosity fluid, the average moving distance can be reduced and the dilution can be easily performed.

As the stirring conditions, the average moving distance obtained by multiplying the peripheral speed of the tip of the stirring blade of the continuous hermetic mixer by the average residence time is appropriately adjusted according to the structure of the continuous hermetic mixer. do it. Specifically, when a single internal nozzle is provided upstream of the stirring blade, the average moving distance is preferably 200 m or more, and more preferably 250 to 450
m. When a plurality of internal nozzles are provided upstream of the stirring blade, the average moving distance is preferably 100 m or more, more preferably 150 to 350 m. By having such an average movement distance, even when diluting an anionic surfactant such that the viscosity has a maximum value due to a decrease in the dilution concentration and the maximum value is 10 times or more the viscosity before dilution, A diluent having a good appearance can be easily obtained. Conversely, if the average moving distance is smaller than this range, only a diluent having a bad appearance (a state in which the gelled high-viscosity fluid and the low-viscosity fluid are individually present and the dilution is uneven) can be obtained.

The reason why the average moving distance can be reduced by increasing the number of the internal nozzles is that the high-viscosity fluid comes into contact with the low-viscosity fluid by increasing the supply ports of the high-viscosity fluid. It is considered that the opportunity (area) increases and the dilution effect increases. Therefore, as the number of supply ports for the high-viscosity fluid increases, the lower limit of the average moving distance tends to decrease.

The ratio of the supply amount of each liquid at the time of dilution is determined by the relationship between the composition of each liquid and the target dilution composition. On the other hand, the dilution processing amount (the amount of the diluent) is the capacity of the continuous closed type mixer. However, industrially, the dilution processing amount is 100 to 1
20 kg / min is also possible.

The dilution temperature may be about 10 to 30 ° C., and a high temperature such as a batch-type dilution operation is not required.
Therefore, in the present invention, the temperature raising / cooling operation performed by the batch type operation becomes unnecessary.

[0030]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to these Examples and the like.

Examples 1 to 9 Continuous dilution of an aqueous solution of anionic surfactant (20 ° C.) shown in Tables 1 and 2 with water (20 ° C.) using a continuous closed mixer under the conditions of Tables 1 and 2 (immediately after dilution) Liquid temperature of 20 ° C.). Tables 1 and 2 show the appearance evaluation of the dispersed state at that time. In addition, ○ indicates uniform dispersion, 米 indicates the presence of a gelled product of rice grain size, and × indicates the presence of a gelled product larger than △.

[0032]

[Table 1]

[0033]

[Table 2]

Comparative Example 1 A 70% aqueous solution of sodium polyoxyethylene (2) lauryl ether sulfate was heated to 80 ° C. over 30 minutes by a batch operation (the liquid volume after dilution was 5000 L).
0 ° C. water is added and stirring is continued at that temperature for 60 minutes to 25%
Diluted. Then, it cooled to 40 degreeC over 2 hours. The dispersion state at that time was good, but the processing amount per 3.5 hours in total was 24 L / min.

Comparative Example 2 A 70% aqueous solution of sodium polyoxyethylene (2) lauryl ether sulfate was heated to 80 ° C. over 30 minutes by a batch operation (the liquid volume after dilution was 5000 L).
0 ° C. water is added and stirring is continued for 90 minutes at that temperature for 30%
Diluted. Then, it cooled to 40 degreeC over 2 hours. The dispersion state at that time was good, but the total processing amount per 4 hours was 21 L / min.

Comparative Example 3 Continuous dilution was performed in the same manner as in Example 5 except that the average residence time was changed to 3 seconds. Table 2 shows the appearance evaluation of the dispersed state at that time.

[0037]

According to the method for continuously diluting an anionic surfactant of the present invention, the viscosity before dilution when diluted with water or the like is 1%.
An anionic surfactant having a maximum value of 0 times or more of viscosity can be efficiently diluted by a simple operation, and can be continuously obtained as a diluent having a good appearance. Therefore, the long mixing time and cooling time required in the conventional batch dilution can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a change in viscosity with respect to the concentration of a surfactant aqueous solution. In the figures, AS is sodium lauryl sulfate (manufactured by Kao Corporation, Emal 10 needle), E
S is sodium polyoxyethylene (2) lauryl ether sulfate (Emal E-70C, manufactured by Kao Corporation), α-
SFE is α-sulfonated fatty acid methyl ester (C ₁₄ /
C ₁₆ = 3/5) (palm-based one synthesized by Kao Corporation).

FIG. 2 is a cross-sectional view of an example of a continuous hermetic mixer used in the present invention.

FIG. 3 is a perspective view of a tip of an internal pipe of the continuous hermetic mixer of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piping 2 Stirrer blade 3 Continuous closed type mixer 4 Mixing chamber 5 Internal piping 6 Internal nozzle

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-249129 (JP, A) JP-A-57-102226 (JP, A) JP-A-4-14132 (JP, U) JP-A-2- 7666 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01F 3/00-3/22 B01F 5/00-5/26

Claims (5)

(57) [Claims] 1. A method for continuously diluting a high-viscosity fluid by supplying a high-viscosity fluid and a low-viscosity fluid from separate pipes to join them, and then mixing them by a mixer provided downstream thereof. The high-viscosity fluid is a liquid containing an anionic surfactant as a main component, the low-viscosity fluid is an aqueous solvent, and the relationship between the two is that the low-viscosity fluid gradually dilutes the high-viscosity fluid at a constant temperature. Sometimes, the maximum value of the viscosity is used, and the maximum value is 10 times or more the viscosity of the high-viscosity fluid before dilution, and the mixer is provided with a mixing chamber independent of the piping and a stirring blade therein. A continuous hermetic mixer provided with an anionic surfactant characterized by supplying a high-viscosity fluid and a low-viscosity fluid such that the average residence time of the mixed fluid in the mixing chamber is 4 seconds or more. Serial dilution method. 2. A single internal nozzle is provided upstream of the stirring blade to supply a high-viscosity fluid therefrom, and the average moving distance obtained by multiplying the average residence time by the peripheral speed of the stirring blade is 200.
The continuous dilution method according to claim 1, wherein m is at least m. 3. A plurality of internal nozzles are provided upstream of the stirring blade to supply a high-viscosity fluid therefrom, and the average moving distance obtained by multiplying the average residence time by the peripheral speed of the stirring blade is 100.
The continuous dilution method according to claim 1, wherein m is at least m. 4. The continuous dilution method according to claim 1, wherein the anionic surfactant is an alkyl sulfate or a polyoxyethylene alkyl ether sulfate represented by the following general formula (I). RO (CH ₂ CH ₂ O) _n SO ₃ M (I) (wherein, R represents a linear or branched alkyl or alkenyl group having 8 to 22 carbon atoms, and _n represents 0 or 1 to 1)
0 represents M, and M represents Na, K, NH ₄ or triethanolamine. ) 5. The high viscosity fluid before dilution has an anionic surfactant concentration of 55 to 80% by weight, and the diluted liquid has an anionic surfactant concentration of 15 to 35% by weight.
The described serial dilution method.