JP2002018254A - Method for manufacturing emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an emulsion, capable of obtaining a fatty acid amide emulsion which contains a fatty acid amide the mean particle size of which is fine and uniform in a dispersed state and has good stability. SOLUTION: A first process for applying shearing force to a fatty acid amide in water at a temperature higher than the fusing temperature of the fatty acid amide to emulsify the fatty acid amide and a second process for charging the emulsion formed in the first process in water the temperature of which is lower than the fusing temperature of the fatty acid amide or the fatty acid amide emulsion to mix the same with water or the emulsion are successively performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an emulsion in which fatty acid amide dispersed in water has a fine and uniform average particle size and good stability.

[0002]

2. Description of the Related Art Generally, as a method for obtaining an oil-in-water emulsion of an organic substance, various surfactants or protective colloids are used as dispersants, and an oil phase is pulverized in an aqueous phase by a mechanical force such as a colloid mill. By using a wet pulverization method to obtain an oil-in-water emulsion by using various surfactants or water-soluble polymers as an emulsifier, and using a homogenizer or the like for the water phase above the melting temperature of the oil phase and the oil phase above the melting temperature of the oil phase. An emulsification method of obtaining an oil-in-water emulsion by emulsifying and dispersing the mixture with a high shearing force and then cooling the mixture with slow cooling or a heat exchanger is known.

However, when a fatty acid amide is used as the oil phase, the former method requires a huge amount of treatment to obtain a stable dispersion having an average particle diameter of 1 μm or less when the concentration of the fatty acid amide is 15% by weight or more. Need time,
There is a problem that only emulsions having poor stability can be obtained because the particle size distribution of dispersed particles is wide. On the other hand, also in the latter method, when the concentration of the fatty acid amide is 10% by weight or more, even if the fatty acid amide takes a good emulsified state at the melting temperature or higher, the viscosity increases upon cooling and the whole liquid gels or solidifies. As a result, a good emulsion cannot be obtained.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a fatty acid amide emulsion in which the dispersed fatty acid amide has a fine and uniform average particle size and good stability. It is an object of the present invention to provide a method for producing an emulsion which can be used.

[0005]

Means for Solving the Problems, Actions and Effects The invention of claim 1 made for solving the above-mentioned object is a method for producing an emulsion, which comprises shearing fatty acid amide in water at a temperature not lower than its melting temperature. It is characterized in that a first step of emulsifying by applying force and a second step of introducing and mixing the emulsion produced in the first step into an aqueous phase lower than the melting temperature of the fatty acid amide are sequentially performed.

According to the first aspect of the present invention, first, in the first step, an emulsion is formed in which the fatty acid amide melted in high-temperature water is dispersed as fine droplets. This is because the fatty acid amide is charged and mixed in an aqueous phase at or below the melting temperature of the fatty acid amide in the second step, so that the temperature rapidly decreases. When the emulsion is quenched in this way, even when the concentration of the fatty acid amide in the emulsion is high, the cooled emulsion does not thicken, gel or solidify, and the fatty acid having a fine and uniform average particle size is not obtained. A good emulsion in which the amide is dispersed can be obtained. Further, this emulsion does not cause aggregation and coagulation of particles or thickening of the emulsion even when left for a long time, and is excellent in stability. Further, in the second step, it is only necessary to mix the emulsion so as to be uniform, and a strong shearing force as in the first step is not required, so that the manufacturing apparatus and the operation are simple. As the aqueous phase used in the second step, water, an aqueous solution obtained by adding an auxiliary agent such as a stabilizer or a surfactant to water, an aqueous emulsion, or the like can be used.

In the second step, an already obtained fatty acid amide emulsion may be used as the aqueous phase (the invention of claim 2). In this case, if the fatty acid amide emulsion having the same concentration as that of the fatty acid amide emulsion obtained in the first step is used, the fatty acid amide emulsion having the same concentration is used in all the steps, and the concentration control is simplified.

[0008] In the first step, water may be heated under a pressure higher than the atmospheric pressure. Under an atmosphere of atmospheric pressure or higher, since the temperature of water can be raised to 100 ° C. or higher, the melting temperature of fatty acid amide is 100 ° C.
This is because even in the above case, the temperature of the fatty acid amide can be raised to the melting temperature or higher by setting the water to 100 ° C. or higher.

Further, the temperature of the aqueous phase in the second step is preferably 30 ° C. or lower than the melting temperature of the fatty acid amide (the invention of claim 4). When the high-temperature emulsion produced in the first step is rapidly cooled with a temperature difference of 30 ° C. or more, a good emulsion can be obtained more stably.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. According to the method for producing an emulsion of the present invention, as described above, first, in the first step, the fatty acid amide is emulsified in water at a temperature higher than its melting temperature by applying a shearing force.
For example, emulsification and dispersion are performed by mixing fatty acid amide, water, and an emulsifier at a temperature equal to or higher than the melting temperature of fatty acid amide in an emulsification container and applying high shearing force with a high-pressure emulsifying and dispersing machine called, for example, a homogenizer. At this time, when the melting temperature of the fatty acid amide to be emulsified is higher than 100 ° C., the emulsification container is preferably closed and pressurized to raise the temperature to 100 ° C. or higher. By doing so, the melted fatty acid amide particles are dispersed in water in a fine and uniform particle size, and a good fatty acid amide emulsion is prepared.

Then, in the second step, the high-temperature fatty acid amide emulsion obtained in the first step is used.
The fatty acid amide is gradually poured into an aqueous phase maintained at a lower temperature than the melting temperature, and mixed uniformly. This way,
The hot emulsion injected into the aqueous phase will soon be homogeneously mixed while being rapidly cooled by being surrounded by the cold aqueous phase. The temperature of the aqueous phase at this time is preferably maintained at a temperature lower than the melting temperature of the fatty acid amide by 30 ° C. or more. As described above, when the fatty acid amide emulsion having a temperature equal to or higher than the melting temperature of the fatty acid amide is rushed, the particles of the fatty acid amide dispersed in water do not agglomerate and coagulate with each other, and the emulsion does not gel. It is possible to obtain an emulsion with good stability in which fine and uniform fatty acid amide particles of 1 μm or less are dispersed.

The concentration of the fatty acid amide emulsion may be adjusted by mixing and diluting the high concentration emulsion prepared in the first step with water or an aqueous phase such as a low concentration emulsion in the second step. , First
In the process, an emulsion having a desired concentration may be prepared, and an emulsion having the same concentration prepared in advance may be charged into an aqueous phase as a refrigerant. When the latter method is adopted, the fatty acid amide emulsion having the same concentration is used in all the steps, and the fatty acid amide emulsion having the desired concentration can be continuously obtained, so that the productivity is high.

In the present invention, the kind of the fatty acid amide dispersed in water may be a commonly used one. Specifically, saturated fatty acid monoamides such as lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, unsaturated fatty acid monoamides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, N-stearyl stearin Acid amide, N-oleyl oleamide, N-stearyl oleamide, N-oleyl stearamide, N-stearyl erucamide, N
-Substituted amides such as oleyl palmitamide, methylol stearamide, methylol amides such as methylol behenamide, methylene bis stearamide, ethylene biscapric amide, ethylene bis lauric amide, ethylene bis stearamide, Ethylenebisisostearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid amide, hexamethylenebishydroxystearic acid amide, N, N'-distearyladipic acid Amides, saturated fatty acid bisamides such as N, N'-distearyl sebacic amide, ethylene bisoleic acid amide, hexamethylene bisoleic acid amide,
Examples include unsaturated aliphatic bisamides such as N'-dioleyl adipamide, and aromatic bisamides such as m-xylylene bisstearic acid amide. These fatty acid amides may be used alone or as a mixture of two or more.

The present invention is particularly applicable to the use of saturated fatty acid monoamides such as lauric amide, palmitic amide, stearic amide, and behenic amide having a melting temperature in the range of about 85 ° C. to 120 ° C. It is suitable.

According to the method for producing a fatty acid amide emulsion of the present invention, the average particle size of the fatty acid amide in the finally obtained emulsion after cooling is 1 μm or less.

In the present invention, the concentration of the fatty acid amide emulsion is not particularly limited, but is preferably from 10 to 40.
% By weight. When the content is 10% by weight or less, a fatty acid amide emulsion can be obtained without thickening and solidifying simply by cooling the high-temperature emulsion as it is. On the other hand, when the concentration is higher than 40% by weight, the high-temperature emulsion does not diffuse sufficiently quickly into the cooling water phase, so that aggregates increase and the viscosity increases, so that a good emulsion cannot be obtained.

If necessary, an emulsifier, an emulsion stabilizer,
Additives such as a rust inhibitor, a fungicide, and an antifoaming agent may be mixed. Emulsifier is not particularly limited, anionic,
Surfactants such as cationic, amphoteric, and nonionic surfactants can be used.

Examples of the anionic surfactant include fatty acids such as lauric acid, palmitic acid, stearic acid and oleic acid, higher alcohol sulfates, higher alkyl ether sulfates, sulfated fatty acid esters and sulfated esters such as sulfated olefins. , Sulfonic acid esters such as alkylbenzenesulfonic acid, alkylnaphthalenesulfonic acid, paraffinsulfonic acid, and sulfosuccinic acid diester, and salts of phosphoric acid esters such as higher alcohol phosphates with alkali metals, alkaline earth metals, or amines And the like.

Examples of the cationic or amphoteric surfactant include quaternary ammonium salts such as alkyltrimethylammonium chloride and alkyldimethylbenzylammonium chloride, alkylpyridium chloride, and alkylbetaine.

Nonionic surfactants include higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, higher alkylamine ethylene oxide adducts, fatty acids Polyamide glycol type such as amide ethylene oxide adducts, ethylene oxide adducts of fats and oils, polypropylene glycol ethylene oxide adducts, or fatty acid esters of glycerol, fatty acid esters of pentaerythritol, fatty acid esters of sorbitol and sorbitan, and fatty acid esters of sucrose And polyhydric alcohols such as alkyl ethers of polyhydric alcohols and fatty acid amides of alkanolamines. These surfactants are used alone or in combination of two or more.

Examples of the emulsion stabilizer include polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl methyl ether, polyethylene oxide, polyacrylamide, polyacrylic acid, carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, starch, gelatin, and higher alcohols.

The mixing ratio of these additives is 0.1 to 100 parts by weight, preferably 3 to 50 parts by weight, based on 100 parts by weight of the fatty acid amide. If the amount is less than 0.1 part by weight, it is difficult to obtain a stable emulsion,
The dispersed particles tend to be coarse. Further, even if it is added in an amount of 100 parts by weight or more, the dispersion stability is not improved, and it is useless.

[0023]

The present invention will be described more specifically with reference to the following examples. <Example 1> In a pressure vessel, palmitic amide 4000 was added.
g, 294 g of lauric acid, 25% by weight ammonia water 10
4 g and 11800 g of water were added, heated to 120 ° C. under pressure, mixed with a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), and further mixed with a high-pressure homogenizer (APPV Ga).
(manufactured by Uulin, Inc.) under a homogeneous pressure of 20 MPa to obtain a high-temperature palmitic acid amide emulsion. Next, 5000 g of water at 20 ° C. was placed in a coolant tank as a coolant, and the above-described high-temperature palmitic acid amide emulsion was gradually mixed into the coolant while being cooled to 60 ° C. or less. Thereafter, the emulsion was further cooled to 30 ° C. to obtain an emulsion having a palmitic acid amide concentration of 20% by weight. When the particle size of the obtained emulsion was measured with a laser scattering particle size measuring device (LA920, manufactured by Horiba, Ltd.), the average particle size was 0.3 μm, and the viscosity at 20 ° C. was 12 mPa · s. Was. In addition,
FIG. 1 shows the particle size distribution.

Example 2 A pressure vessel was charged with 4000 g of palmitic amide, 300 g of palmitic acid, 80 g of 25% by weight aqueous ammonia, and 7400 g of water, and a high-temperature palmitic amide emulsion was prepared in the same manner as in Example 1. Obtained. Next, 1774 g of water at 20 ° C. was placed in a coolant tank as a refrigerant, and the high-temperature palmitic acid amide emulsion was gradually mixed in the refrigerant in the same manner as in Example 1 to obtain 30% by weight of palmitic acid at 30 ° C. An amide emulsion was obtained. The average particle size of the obtained emulsion was 0.1.
6 μm and a viscosity at 20 ° C. of 18 mPa ·
s.

Example 3 3000 g of palmitic acid amide, 221 g of lauric acid, 76 g of 25% by weight aqueous ammonia, and 12903 g of water were charged into a pressure vessel, and a high-temperature palmitic acid amide emulsion was obtained in the same manner as in Example 1. Was. Next, the palmitic acid amide emulsion of 20% by weight obtained in Example 1 was used instead of water as a refrigerant, and the high-temperature palmitic acid amide emulsion was gradually added to the refrigerant in the same manner as in Example 1. Mix, 3
A 20% by weight palmitic amide emulsion at 0 ° C. was obtained. The average particle size of the obtained emulsion is 0.4 μm
And the viscosity at 20 ° C. was 11 mPa · s.

Example 4 The procedure of Example 1 was repeated, except that stearic acid amide was used instead of palmitic acid amide, to obtain an emulsion containing 20% by weight of stearic acid amide. The average particle size of the obtained emulsion is 0.3
μm, and the viscosity at 20 ° C. is 13 mPa · s.
Met.

Example 5 The procedure of Example 1 was repeated, except that behenic acid amide was used instead of palmitic acid amide, to obtain an emulsion containing 20% by weight of behenic acid amide. The average particle diameter of the obtained emulsion was 0.8 μm, and the viscosity at 20 ° C. was 12 mPa · s.

<Comparative Example 1> After a high-temperature emulsion was obtained in the same manner as in Example 1, the solution was cooled as it was. As a result, the whole liquid was solidified and a liquid emulsion could not be obtained.

<Comparative Example 2> A high-temperature emulsion obtained in the same manner as in Example 1 was withdrawn from a pressurized emulsification tank while being cooled through a plate heat exchanger. Could not be obtained.

Comparative Example 3 Stearamide 200
g, 8 g of dioctyl sulfosuccinate soda salt and 798 g of water were mixed and wet-pulverized by a batch-type bead mill using 1.5 mm glass beads. The dispersion thus obtained had an average particle size of 2.5 μm.
FIG. 2 shows the particle size distribution.

As shown in the above Examples, the fatty acid amide emulsions prepared by the production method of the present invention each have a dispersed fatty acid amide having an average particle diameter of 1%.
It was fine as μm or less, and no thickening, gelling or solidification occurred. On the other hand, in the case of the comparative example, the average particle diameter of the fatty acid amide was increased, or the emulsion was thickened or solidified, so that a fatty acid amide emulsion in a good state could not be obtained.

[Brief description of the drawings]

FIG. 1 is a graph showing the particle size distribution of Example 1.

FIG. 2 is a graph showing the particle size distribution of Comparative Example 3.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Usami 2-1 Buchagawa-cho, Nakagawa-ku, Nagoya-shi Nakagyo Oil & Fat Co., Ltd. F-term (reference) 4G035 AB40 AE15 4G065 AA01 AB12Y AB18Y BA03 BA04 BA05 BA06 BA07 BA11 BA13 BA14 CA03 EA01 EA05 EA10 FA01 4H006 AA02 AD40 BA50 BE14 BE60 BV21

Claims (4)

[Claims] A first step of emulsifying a fatty acid amide in water by applying a shearing force at a temperature not lower than its melting temperature;
A second step of introducing and mixing the emulsion produced in the step into an aqueous phase at or below the melting temperature of the fatty acid amide, and sequentially mixing the emulsions. 2. The method according to claim 1, wherein the aqueous phase in the second step is a fatty acid amide emulsion. 3. The method for producing an emulsion according to claim 1, wherein in the first step, water is heated under a pressure higher than the atmospheric pressure. 4. The emulsion according to claim 1, wherein the temperature of the aqueous phase in the second step is 30 ° C. or lower than the melting temperature of the fatty acid amide. Method.