JPH0146559B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for atomizing a cationic surfactant in water. Generally, cationic surfactants have excellent softening effects, and among them, dioctadecylzamethylammonium chloride, which is a quaternary ammonium salt, is particularly widely used as a fabric softener. In addition to these quaternary ammonium salts, The phosphionium salt represented by the general formula is It is also known that cationic surfactants such as amide/amine salts represented by the following formula have excellent softening effects. These surfactants have hydrophobic long-chain alkyl groups, so they have excellent adsorption properties to clothing.
Most of these surfactants are poorly soluble in water, and in order to make them easier to use as softeners, most of these surfactants are dispersed in water, and nonionic surfactants or organic salts are added as anti-gelling agents. , inorganic salts, etc. are added, and alcohol is added as a low-temperature stability improver to suppress the viscosity to around 50 to 300 cp. The softening effect of cationic surfactants on clothing is evident from Figure 1, which shows the relationship between the amount of dioctadecylzamethylammonium chloride adsorbed onto cotton towels and the softness of the cotton towels. It is obtained in proportion to the amount of surfactant adsorbed on clothing, etc. In addition, the amount of cationic surfactant adsorbed onto clothing is clear from Figure 2, which shows the relationship between the amount of adsorption and the particle size of the cationic surfactant. be done. That is, FIG. 2 shows the softening of cotton towels using samples in which the two types of dioctadecylzamethylammonium chloride shown in Table 1, A and B, are dispersed at various concentrations, and the cotton towels are soaked in chloroform using a Soxhlet extractor. The amount of dioctadecyldimethylammonium chloride adsorbed onto the cotton towel was determined by measuring the amount of dioctadecyldimethylammonium chloride in the extract. It is shown in relation to the concentration of chloride.

[Table] Since the amount of quaternary ammonium salt adsorbed onto clothing is further increased when the particles are fine, it can be concluded that fine particles have an excellent softening effect. However, although cationic surfactants have excellent adsorption properties to clothing as mentioned above, many of them are poorly soluble in water, and when cationic surfactants come into contact with water, their surface becomes a liquid crystal structure. The surface viscosity increases and becomes a viscous liquid, making it extremely difficult to form particles. In other words, many synthetic surfactants take on a liquid crystal structure at a certain concentration or higher, and this liquid crystal is a crystalline liquid with weak interactions between molecules but regular arrangement of molecules, so it cannot be used in normal aqueous solutions or liquid crystals. It is known to have unique properties compared to solid melts, and often forms a viscous liquid. In the case of quaternary ammonium salts, for example, dioctadecylzamethylammonium chloride and didodecyldimethylammonium chloride have been reported to have wide liquid crystal regions, as is clear from the phase diagrams shown in Figures 3 and 4, respectively. has been done. When a quaternary ammonium salt with such properties is added to water (hot water), its surface comes into contact with the water and reaches the temperature-concentration range of the liquid crystal region shown in Figures 3 and 4, thereby causing As a result, the surface of the quaternary ammonium salt becomes a liquid crystal structure or a similar structure, and the surface becomes viscous, making it difficult to form fine particles. In the production of general softeners using such cationic surfactants, for example, gelation is prevented by maintaining the melted quaternary ammonium salt or its mixture at a temperature equal to or higher than the Kraft point of the quaternary ammonium salt. A method is adopted in which the agent is added to hot water containing the agent and dispersed using a paddle-type stirrer or a propeller-type stirrer. However, as mentioned above, the quaternary ammonium salt increases its viscosity when it comes into contact with water, so it is difficult to properly atomize the cationic surfactant using the above-mentioned general stirrer. In order to obtain this, it is necessary to use a special stirrer for emulsification such as a homogenizer that rotates small stirring blades at high speed, but the special stirrer for emulsification mentioned above can only process a small amount of softener at one time, and cannot be used as a batch type. When used, there were major problems in putting it into practical use, such as poor overall mixing ability within the stirring tank body. Cationic surfactants are used not only for the softening of clothing as mentioned above, but also for various other purposes, such as water repellents such as floor polishes and curling agents, and antistatic agents for textiles. In such cases, it is effective to micronize the cationic surfactant in water. The present invention has been made in view of the above, and aims to provide a method for efficiently finely dispersing a cationic surfactant in water using a general stirring blade. That is, the method of the present invention is a method in which a cationic surfactant is supplied to the suction side of a stirring blade rotating in water in a tank body, and is atomized by being wound around the stirring blade, in which the stirring blade is , using a stirring blade that causes water on the outer circumferential side of the blade to flow in the axial direction toward the front of the blade, and applying the above cationic surfactant to the stirring blade in such a manner that the distance a from the rotation center of the stirring blade is r/2≦a≦r, and from the stirring blade It is characterized by supplying at a position where the distance b is b≦r (where r is the radius of the stirring blade). When the cationic surfactant is atomized by such a method, an excellent atomization effect can be obtained, as is clear from the examples described below.Moreover, when a special stirrer for emulsification such as a homogenizer is used, Compared to this, it becomes possible to perform atomization extremely efficiently. Hereinafter, the present invention will be explained in more detail with reference to the drawings. 5 and 6A and 6B show an example of an apparatus for carrying out the method of the present invention. In this apparatus, a rotor that rotates in the direction of the arrow by a drive source (not shown) is mounted at the center of the tank body 1. A stirring blade 3 attached to a shaft 4 is provided. This stirring blade 3 is called a jet type stirring blade, and the peripheral side of each plate-shaped blade plate 3a protruding from the rotating shaft 4 is curved in the axial direction at the curved portion 3b so as to have a windmill shape as a whole. I'm letting you do it. Therefore, for example, a propeller-type stirring blade generates an axial flow along the axis of rotation, whereas in a jet-type stirring blade, water on the outer peripheral side of the blade flows in an axial direction toward the front of the blade. The supply pipe 5 for supplying the cationic surfactant is arranged on the suction side of the water flow generated by the rotation of the stirring blade 3 at a position where a strong suction flow is generated.
As a result, all of the supplied cationic surfactant is drawn into the stirring blades 3 and atomized. In order to ensure that the cationic surfactant is sufficiently finely divided in relation to the generated water flow, the stirring blade 3 should preferably have a diameter of 1/2 or less of the inner diameter of the tank body 1. There is. The cationic surfactant supply pipe 5 includes a pipe portion 5a that extends to a position where the suction flow is strong on the outer peripheral side of the blade behind the stirring blade 3, and a supply port 6 is opened at the tip of the pipe portion 5a. However, the supply pipe 5
As shown in FIG. 5, the supply port 6 is opened at the tip of a tube section 5a made of a single tube, or as shown in FIG. 7, the tip of the tube section 5a is made into an annular tube section 5b. It is possible to use an annular tube portion 5b having supply ports 6, 6, . . . opened therein. Further, the supply port 6 may have a single-hole structure with a single hole, or may have a multi-hole structure with a large number of unit holes 7, 7, etc. as shown in FIGS. 8 and 9. In either of these structures, the diameter of the supply port 6 is preferably 1/2 or less of the radius of the stirring blade 3. FIG. 10 shows that the supply position of the cationic surfactant in the tank body 1 is determined in relation to the stirring blade 3 shown in FIGS. 5 and 6, A and B, and the surfactant is This figure shows the results of an experiment to determine how much of the liquid is drawn into the stirring blade 3. The supply pipe shown in FIG. 7 was used. In FIG. 10, distance a and distance b on the horizontal and vertical axes respectively indicate a and b in FIG.
That is, the distance a is the distance between the supply port 6 and the center of rotation of the stirring blade 3, and the distance b is the distance between the supply port 6 and the stirring blade 3, in relation to the radius r of the stirring blade 3. It is expressed. According to this FIG. 10, it is desirable that the supply position of the cationic surfactant, that is, the position of the supply port 6, be within the range expressed by a=≦2r, b≦2r. In addition, Fig. 11 and Fig. 12 show experimental examples regarding the relationship between the feed liquid addition position and atomization for the same stirring blade as described above, and Fig. 11 shows the relationship between a and a while keeping the value of b constant. FIG. 12 shows the change in the atomization state when the value of a is kept constant and b is varied. According to these experimental results, the cationic surfactant is supplied at a position where the distance a from the rotation center of the stirring blade is r/2≦a≦r and the distance b from the stirring blade is b≦r. It can be seen that an excellent atomization effect can be obtained. In FIG. 11, when the distance a from the center of rotation of the stirring blade is in the range a<r/2, the feed liquid passes through the blades in a manner that it wraps around the stirring shaft, making it difficult to atomize. In addition, in the range a>r, the supply liquid is discharged downward from the blade tip, so
In this case as well, it becomes difficult to atomize the particles. Furthermore, in Fig. 12, when the distance b from the stirring blade is in the range b>1, the suction force becomes low, so the supply liquid is more likely to be dispersed without hitting the blade, becomes coarse grained. As described above, according to the method of the present invention, by supplying the cationic surfactant in a specific positional relationship with the stirring blade, it can be sufficiently finely dispersed by the jet-type stirrer. In addition, since a member such as a guide for guiding the cationic surfactant in the direction of the stirring blade is not required, the configuration of the device is also simplified. Next, embodiments of the present invention will be described. Example 1 Tank body: Volume 40 Stirring blades: Jet-type stirring blades with the structure shown in Figures 5 and 6 A and B, blade tip peripheral speed 11.8 m/sec Supply pipes: Supply port diameter 0.08r x 12 pieces, supply position a
= Arranged on the circumference of 4/5r, b = 1/4r Contains polyoxyethylene alkyl phenyl ether (0.5%) using an apparatus having the above configuration.
A mixture of dimethylammonium chloride and ethylene glycol heated to 55°C was supplied from a supply pipe into hot water heated to 40°C for 30 minutes,
The dispersion (ripening) time was set to 0 minutes. This results in
It was confirmed that particles with a size of 0.65μ or less accounted for 87% or more, but in a comparative example in which the above mixture was added to the liquid surface under similar experimental conditions, the proportion of particles with a size of 0.65μ or less was 21% or less. The photographs in Figures 13 and 14 are
Microscopic photographs (×300) of the dispersions obtained in the above Examples and Comparative Examples are shown, and it is clear that in the above Examples, no coarse particles of 1μ or more were observed. In the case of the comparative example, many coarse particles were observed, and it is clear that sufficient atomization was not performed.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between the amount of dioctadecyldimethylammonium chloride adsorbed onto a cotton towel and the flexibility of the cotton towel, and Figure 2 is a diagram showing the relationship between the concentration of dioctadecyldimethylammonium chloride and the amount of adsorption onto the cotton towel. FIG. 3 is a dioctadecyldimethylammonium chloride-aqueous phase equilibrium diagram, FIG. 4 is a didodecyldimethylammonium chloride-aqueous phase equilibrium diagram, and FIG. 5 is a sectional view of an apparatus for carrying out the present invention. 6A and B are a plan view and a perspective view of the stirring blade, FIGS. 7 to 9 are a side view and a partial perspective view showing different types of supply pipes and supply ports, and FIG. 10 is a diagram of a cationic surfactant. Explanatory diagram showing the addition position and the quality of suction to the stirring blade, No. 11
Figures 1 and 12 are diagrams showing the relationship between the feed liquid addition position of the jet type stirring blade and atomization, and Figures 13 and 14 are diagrams showing the dispersion particles obtained in the examples of the present invention and their comparative examples. This is a micrograph used as a drawing. 1... Tank body, 3... Axial flow type stirring blade, 5... Supply pipe,
6... Supply port.

Claims (1)

[Scope of Claims] 1. A method of supplying a cationic surfactant to the suction side of a stirring blade rotating in water in a tank body and atomizing it by winding it into the stirring blade, the stirring blade comprising: Using a stirring blade that causes water on the outer circumferential side of the blade to flow in the axial direction toward the front of the blade, the above cationic surfactant is applied at a distance a from the rotation center of the stirring blade such that r/2≦a≦r, and from the stirring blade to A method for atomizing a cationic surfactant in water, characterized in that the distance b is supplied at a position where b≦r (where r is the radius of a stirring blade).