JP2001179076A - Method for manufacturing oil-in-water type emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a stable emulsion by using an oily component, a nonionic surfactant and a clay mineral. SOLUTION: This method for manufacturing an oil-in-water type emulsion is characterized in that an oil phase is prepared by mixing at least the oily component, the nonionic surfactant, the clay mineral and (a) a small amount of water or (b) a low molecular weight polyhydric alcohol and the oil phase and the water phase are mixed and emulsified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an oil-in-water emulsion, and more particularly to a method for producing an oil-in-water emulsion which has high stability of emulsified particles and can be used for cosmetics, detergents and the like.

[0002]

2. Description of the Related Art Conventionally, as a technique of utilizing a clay mineral when producing an emulsion, for example, a method of dispersing a clay mineral in water to stabilize an oil-in-water emulsion without using a surfactant ( JP-A-58-124535
And a method of dispersing a cation-modified clay mineral in oil to form a water-in-oil emulsion (JP-A-62-21663).
No. 5 publication) is known. A technique for forming an oil gel with a surfactant, an oil component, and a clay mineral is also known (Japanese Patent Application Laid-Open No. 54-79183). Further, JP-A-8-126833 discloses that (A) (a) 1 to 10 moles of ethylene oxide is added to a partial ester of a fatty acid and a polyhydric alcohol having at least three or more hydroxyl groups in a molecule and to a hydroxyfatty acid triglyceride. (B) an aqueous solution containing one or more amino acids and / or salts thereof in an amount of 0.1% or more;
a water-in-oil type emulsifier composition in which the ratio of (b) is 1: 1 to 1:46 by weight, and (B) an organically modified clay mineral of 0.1 to 1
A water-in-oil emulsion having good usability and stability containing 0.0% and (C) 1 to 20% of silicone oil is disclosed. It is prepared by dispersing the organically modified clay mineral and silicone oil (C), and then adding and dispersing the above (A). All of these prior art methods use a clay mineral on the continuous phase side to increase the viscosity of the continuous phase and stabilize the dispersed phase. In other words, those using unmodified clay minerals form a swelled structure in the aqueous phase by making use of the aqueous properties, and those using organically modified clay minerals make use of the oily properties by using the oily properties. The system is stabilized by forming a swelling structure therein.

[0003]

The present invention relates to an oily component,
An object of the present invention is to provide a method for producing a stable emulsion using a nonionic surfactant and a clay mineral.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on the formation of a stable emulsion. As a result, a clay mineral was blended with a specific component in a dispersed phase and emulsified by a specific method. It has been found that the stability of the emulsified particles themselves is improved, and a fine and stable oil-in-water emulsion can be obtained, thus completing the present invention.

That is, the present invention provides the following (1) to (2)
Exists. (1) at least an oily component, a nonionic surfactant,
A method for producing an oil-in-water emulsion, comprising mixing a clay mineral and a small amount of water to prepare a viscous oil phase in which the clay mineral is dispersed, and mixing and emulsifying the oil phase and the aqueous phase. . (2) at least an oil component, a nonionic surfactant,
A clay mineral and a low molecular weight polyhydric alcohol are mixed to prepare a low-viscosity oil phase in which the clay mineral is dispersed, and an aqueous phase is gradually added to the oil phase to perform phase inversion emulsification. A method for producing an oil-in-water emulsion.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The method of the present invention comprises mixing at least an oil component, a nonionic surfactant, a clay mineral and (a) a small amount of water or (b) a low molecular weight polyhydric alcohol to form an oil phase. The oil-in-water emulsion is manufactured by mixing and emulsifying the oil phase and the aqueous phase.

The oily component used for preparing the oil phase in the method of the present invention includes, for example, hydrocarbons, animal and vegetable oils, silicone oils, synthetic oils and the like, and particularly those which are liquid at room temperature are preferably used. . Specific examples of the oily component include liquid paraffin, squalane, olive oil, jojoba oil, corn oil, soybean oil, coconut oil, palm oil, dimethyl silicone oil, methylphenyl silicone oil, cyclic dimethyl silicone oil, isopropyl myristate, and myristate. Octyldodecyl, isopropyl palmitate and the like can be mentioned.

The nonionic surfactants include polyoxyethylene alkyl ether, sorbitan fatty acid ester, polyglycerin fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene hydrogenated castor oil, and polyether. Modified silicone is exemplified. In the present invention, a liquid at room temperature is suitably used. Specific examples of such a nonionic surfactant include polyoxyethylene (2) oleyl ether, sorbitan monooleate, sorbitan sesquioleate, diglyceryl monooleate, decaglyceryl pentaoleate, and polyoxyethylene. (2) monooleate, polyoxyethylene (5) nonylphenyl ether, polyoxyethylene (10) hydrogenated castor oil, dimethylsiloxane / methyl (polyoxyethylene) siloxane copolymer,
A dimethylsiloxane / methyl (polyoxyethylene) siloxane / methyl (polyoxypropylene) siloxane copolymer is exemplified. If the HLB is too high, it tends to be less compatible with the oily component.

Examples of the clay mineral include smectite clay such as natural or synthetic bentonite, montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, and stevensite.
Swellable fluorine mica, etc., which may be used alone or
More than one kind can be used in appropriate combination. In the present invention, a non-organic modified clay mineral is particularly preferably used.

In the method of the present invention, (a) a small amount of water or (b) a low molecular weight polyhydric alcohol is mixed in the preparation of the oil phase, but the purpose of mixing these depends on the state of the oil phase. (A) A small amount of water is used for the purpose of easily increasing the viscosity of the oil phase, and the oil phase is mixed by mixing three components of an oil component, a nonionic surfactant and a clay mineral. It is used when the viscosity of the oil phase when prepared is about 0.1-3 Pa · s. On the other hand, (b) low molecular weight polyhydric alcohol is used for the purpose of suppressing the increase in the viscosity of the oil phase, and is obtained by mixing three components of an oil component, a nonionic surfactant, and a clay mineral. It is used when the viscosity of the oil phase when the oil phase is prepared is about 50 Pa · s or more. Depending on the system used, which method should be selected should be determined by mixing the three components of the oil component, nonionic surfactant and clay mineral, and examining the viscosity when the equilibrium is reached. Can be determined by Here, a small amount of water of the component (a) is added separately from the water originally held by the clay mineral. In the present invention, “a small amount of water” may be any amount as long as the clay mineral maintains a continuous phase and maintains an appropriate viscosity. Specifically, 1 to 20% by mass based on the dried clay mineral ( Hereinafter, simply referred to as “%”), and preferably ranges from 3 to 10%.
%. In the present invention, the degree of the viscosity varies depending on the amount of the component (a). Within the above range, when the amount of water is small, the oil phase viscosity decreases, and when the amount of water is large, the oil phase viscosity increases. Generally, higher oil phase viscosity is preferable because the oil holding power tends to be stronger when emulsified particles are used,
If the viscosity is too high, the oil phase may be poorly dispersed.
If the amount of water used is less than 1%, a sufficient effect cannot be obtained because the water is originally absorbed within the range of the amount of water (vibration width) brought by the clay mineral.

The low molecular weight polyhydric alcohol (b) includes, for example, ethylene glycol, propylene glycol, butylene glycol, sorbitol, dipropylene glycol, glycerin and the like. here,
“Low molecular weight” means that the alkyl chain portion in the polyhydric alcohol has about 2 to 6 carbon atoms. The blending amount of the polyhydric alcohol is preferably about 15 to 50% based on the nonionic surfactant, and more preferably 20 to 35%. If the amount of the polyhydric alcohol is too small, the system may thicken. If the amount is too large, the emulsification may not be successful.

The aqueous phase in the present invention contains water as a main component, but it is possible to appropriately mix optional components as described later.

Next, the method for preparing and emulsifying the oil phase in the present invention will be described separately for (a) a case where a small amount of water is used and (b) a case where a low molecular weight polyhydric alcohol is used.

First, the preparation of a viscous oil phase using the component (a) is carried out by mixing an oil component, a nonionic surfactant, a clay mineral and a small amount of water. First, a clay mineral and water are dispersed in an oily component, and then a nonionic surfactant is added and mixed. Here, “viscous” generally refers to a state of high viscosity, but in the present invention, it means that the viscosity is about 3.5 to 40 Pa · s, and preferably about 5 to 30 Pa · s. . The mixing of the components can be carried out within the normal operating range of the stirrer. However, it is preferable to use a blade having a high viscosity so that the whole can be easily mixed because the viscosity increases during the mixing.
Examples of the usable stirrer include a paddle mixer, an azihomomixer, and a hibis dispermix. The mixing temperature is preferably from room temperature to about 90 ° C. Mixing is performed until the viscosity of the system increases and becomes viscous. The time for increasing the viscosity of the system varies depending on the mixing power and the temperature, but a standard of the mixing time is preferably about 10 minutes to 2 hours. The stronger the mixing power, the faster the viscosity can be increased. The viscous oil phase prepared as described above is in a state in which the layer structure of the clay mineral is dispersed and dispersed in a dispersion medium comprising a nonionic surfactant and an oil component.
When the oil phase is prepared using the component (a), the ratio of each component is in the range of 1/10 to 1/4, particularly 1/8 to 1 for the ratio of the nonionic surfactant to the oil component. / 5 is preferable. Further, the ratio of the clay mineral to the oily component is preferably in the range of 1/10 to 1/4, particularly preferably in the range of 1/8 to 1/5. However,
The above range is merely an example, and the viscosity level of the oil phase formed by the oil component, the nonionic surfactant, the clay mineral, and the four components of water is about 3.5 to 40 Pa. If it is about s, it may be out of the above range.

The emulsification of the viscous oil phase obtained by using the component (a) is carried out by (1) a method in which the oil phase is added to the aqueous phase under high shear to emulsify, and (2) the aqueous phase is emulsified. It is carried out by a method of emulsifying by adding to the oil phase under high shear, (3) a method of gradually adding an aqueous phase to the oil phase and emulsifying a phase inversion, or the like. When the viscosity of the oil phase is not very high (for example, when the viscosity is about 15 Pa · s or less), the method of (1) or (2) above, in which the emulsion is added under high shear and emulsified, is preferable. As the emulsifying conditions in the above methods (1) and (2), it is preferable that the emulsifying power is set to a high shear level, that is, a normal use range of a homomixer. The emulsification temperature is preferably in the range of room temperature to about 90 ° C., and the emulsification time is preferably set until uniform emulsified particles are formed (about 10 minutes to 2 hours is a guide). On the other hand, when the viscosity of the oil phase is high (for example,
When the oil phase exceeds about 15 Pa · s), it becomes difficult to transfer the oil phase itself. Therefore, first, the water phase of the above (2), which is a method of preparing the oil phase in an emulsification kettle, is used as the oil phase. A method of adding and emulsifying under high shear, or a method of (3) gradually adding an aqueous phase to an oil phase and effecting phase inversion is preferred.
The conditions of the method (2) are as described above. As a condition of the phase inversion emulsification of (3), first, the emulsifying power is preferably set to an agitator level of an aziomomixer.
The emulsification temperature is preferably in the range from room temperature to about 90 ° C. In phase inversion emulsification, the addition of an aqueous phase to an oil phase is performed gradually. Here, "slowly adding" depends on the size of the emulsification kettle.
The rate of adding the aqueous phase of about 0 kg in about 3 to 10 minutes is a rough guide, but it is preferable to add the aqueous phase slowly little by little since the aqueous phase is hardly adapted at the beginning of the addition. Also, the required amount may be added in portions (for example,
3 to 20). The emulsification time is preferably about 30 minutes to 2 hours in all steps when gradually added, and in the case of divided addition, after adding each aqueous phase involved in the division, 5 minutes.
It is preferable to emulsify every about 20 minutes. In the formation of the emulsion, the ratio of the oil phase to the aqueous phase is set to 1:10
The ratio is preferably about 1: 1, particularly preferably about 1: 5 to 1: 2. In the oil phase, for example, an antibacterial agent, a preservative, a coloring matter, a fragrance and the like can be blended as optional components. In the aqueous phase, for example, a water-soluble polymer, a preservative, an antibacterial agent, alcohols, A hydric alcohol, a dye, and the like can be blended as optional components. Further, for example, a pigment such as titanium oxide can be dispersed in an aqueous phase or an oil phase in advance.

On the other hand, (b) the preparation of a low-viscosity oil phase using a low-molecular-weight polyhydric alcohol is carried out by mixing an oily component, a nonionic surfactant, a clay mineral and a low-molecular-weight polyhydric alcohol. Preferably, the method is carried out by dispersing a clay mineral in an oily component, adding a mixture of a nonionic surfactant and a polyhydric alcohol thereto, and mixing. Here, “low viscosity” generally refers to a low viscosity state, but in the present invention, it means that the viscosity is in a range of about 0.01 to 3 Pa · s. Here, the viscosity level at the time of preparing the oil phase is different from the case where (a) a small amount of water is added, because the polyhydric alcohol lowers the viscosity of the oil phase. Even if the phase has a low viscosity, stable particle formation can be similarly achieved by performing phase inversion emulsification thereafter. The mixing of the components can be carried out in the ordinary operation range of the stirrer, but it is preferable to use a blade having high viscosity and easy to mix as a whole because the viscosity increases in the phase inversion emulsification step. Examples of the usable stirrer include a paddle mixer, an azihomomixer, and a hibis dispermix. The mixing temperature is preferably from room temperature to about 90 ° C. Mixing is performed until the entire system is adjusted, and as a guide, it is preferably about 30 minutes to 2 hours. The low-viscosity oil phase prepared as described above has a layer structure of the clay mineral which is slightly dispersed and is dispersed in a dispersion medium composed of a nonionic surfactant and an oily component, but has a low viscosity. Therefore, when the stirring is stopped, the clay mineral is settled.

When the oil phase is prepared by using the component (b), the ratio of each component is in the range of 1/4 to 1/1, especially 1/1, with respect to the ratio of the nonionic surfactant to the oil component. 4
It is preferable to set the range to 〜. Further, regarding the oily component and the clay mineral, the ratio is in the range of 1/4 to 1/1, particularly 1: 1.
It is preferable to be in the range of to １ ／. The proportion of the polyhydric alcohol as the component (b) is preferably 15 to 50%, particularly preferably 20 to 35%, based on the nonionic surfactant. If the amount of the polyhydric alcohol is small, the viscosity of the oil phase is increased, and the oil phase may be poorly dispersed. If the amount is large, the oil phase may be separated. However, the above range is merely an example, and the present invention is not limited to the above range, and is not limited to four components such as an oil component, a nonionic surfactant, a clay mineral, and a polyhydric alcohol.
If the viscosity level of the oil phase formed by the components is about 3 Pa · s or less, it may be out of the above range.

The emulsification of the obtained low-viscosity oil phase is carried out by gradually adding an aqueous phase to the oil phase and carrying out phase inversion emulsification. As the conditions for the phase inversion emulsification, it is preferable that the emulsifying power is at the level of an agitator of an azihomomixer, and the emulsifying temperature is preferably in the range of room temperature to about 90 ° C. In phase inversion emulsification, the addition of an aqueous phase to an oil phase is performed gradually. Here, “slowly” is added depending on the size of the emulsification kettle.
The rate of adding the aqueous phase of about 0 kg in about 3 to 10 minutes is a rough guide, but it is preferable to add the aqueous phase slowly little by little since the aqueous phase is hardly adapted at the beginning of the addition. Also, the required amount may be added in portions (for example,
3 to 30). The emulsification time is preferably about 30 minutes to 2 hours in all steps in the case of gradual addition, and 5 minutes after the addition of each aqueous phase involved in the division in the case of divisional addition.
It is preferable to emulsify every about 20 minutes. In addition,
During the addition of the aqueous phase, the viscosity of the system becomes 30 Pa · s or more, but it is preferable to control the method of dividing water as far as the power of the stirrer allows. Is about 1:10 to 1: 1, especially 1: 5 to 1:
It is preferred to be about 2. In the oil phase, for example, an antibacterial agent, a preservative, a dye, a fragrance and the like can be blended as optional components, and in the aqueous phase, for example, a water-soluble polymer,
Preservatives, antibacterial agents, alcohols, pigments and the like can be blended as optional components. Further, for example, a pigment such as titanium oxide can be previously mixed in the water phase or the oil phase.

The oil-in-water emulsion of the present invention obtained as described above has high stability of emulsified particles, and is widely used for various uses such as cosmetics, detergents, pharmaceuticals, and housing-related products. Available.

[0020]

The method of the present invention differs from the prior art in that a special structure is formed inside the dispersed phase by using a clay mineral on the dispersed phase side. That is, the emulsified particles of the oil-in-water emulsion obtained by the method of the present invention are considered to have a form in which the oily component is wrapped in a capsule-like structure formed by a clay mineral,
As a result, the emulsion is stabilized against external changes, and for example, even when mixed with other surfactant micelles, the emulsified particles are hardly destroyed (that is,
Less oily components leak from emulsion droplets). In addition, in the method of the present invention, by adding a small amount of water to the oil phase, the thickening of the oil phase composed of an oil component, a nonionic surfactant and a clay mineral can be promoted, or By adding a low-molecular-weight polyhydric alcohol to, a high-viscosity oil phase is prevented, and a fine oil-in-water emulsion can be formed while maintaining the fluidity of the oil phase.

[0021]

Next, the present invention will be described in more detail with reference to examples and test examples, but the present invention is not limited to these examples. In addition, in the following Examples and the like, "parts" all means parts by mass.

Example 1 Dimethylpolysiloxane (trade name: SH200 30cs)
(Centistokes); 1.6 parts of Toray Silicone and 6 parts of vegetable squalane (Phytosqualane; trade name of Iwase Kosfa) and 1.6 parts of bentonite (trade name: Bengel FW; Toysunyo Yoko, 8% loss on drying) and Disperse 0.08 parts of water, and polyether-modified silicone (trade name: SH377)
(5M; manufactured by Toray Silicone Co., Ltd.) and mixed at 80 ° C. When paddle stirring was continued, the viscosity of the system increased in 30 minutes and reached 10 Pa · s with a BH type viscometer. This was designated as a viscous oil phase. On the other hand, 8 parts of sorbit (60% solution) was dissolved in 26 parts of purified water to prepare an aqueous phase. The viscous oil phase was added to the aqueous phase with stirring with a homomixer and emulsified for 15 minutes. The properties of the obtained emulsion are as follows:
070 mPa · s, the particle size was about 1 to 7 μm by microscopic observation, and no oil floating was observed.

Example 2 A viscous oil phase (15 Pa · s) was prepared in the same manner as in Example 1 (the mixing temperature was 30 ° C.), and a total of 34 parts of water was added in two portions. And mixed. The mixing time was 5 minutes with a scraping mixer each time 2 parts of water were added. The properties of the obtained emulsion were 520 mPa · s in viscosity,
The particle size was about 1 to 4 μm by microscopic observation, and no oil floating was observed.

Example 3 10 parts of vegetable squalane (trade name: phytosqualan; manufactured by Iwase Cospha) was added to bentonite (trade name: Kunipia F;
1.8 parts of water and 0.1 part of water by Kunimine Industries Co., Ltd.
One part was dispersed, and 1.8 parts of polyoxyethylene (3) glyceryl monoisostearate (trade name: GWIS-103; manufactured by Nippon Emulsion Co., Ltd.) was added and mixed at 50 ° C. When paddle stirring was continued, the viscosity of the system increased in 30 minutes, and reached 7 Pa · s with a BH type viscometer. This was designated as a viscous oil phase. On the other hand, sorbit (60%
5 parts) and an aqueous phase was prepared. These are described in Example 1.
When emulsified in the same manner as above, the viscosity was 1530 mPa
An emulsion having a particle size of 1 to 7 μm was obtained. No oil floating on the emulsion surface was observed.

EXAMPLE 4 To 12 parts of isopropyl myristate (trade name: IPM-EX; manufactured by Nikko Chemicals Co., Ltd.) was added 2 parts of bentonite (trade name: Bengel FW; manufactured by Toyshun Yoko Co., Ltd., loss on drying 7.5%) and 0.1 parts of water. Two parts were dispersed, and 2.2 parts of polyoxyethylene (12) diisostearate (trade name: 600 di-IS; manufactured by Nippon Emulsion Co., Ltd.) was added and mixed at 40 ° C. If paddle stirring is continued, the viscosity of the system increases in 30 minutes, and B
It became 6 Pa · s in the H type viscosity system. This was used as a viscous oil phase and emulsified in 35 parts of purified water in the same manner as in Example 1 to obtain an emulsion having a viscosity of 2,050 mPa · s and a particle size of 1 to 8 µm. No oil floating on the emulsion surface was observed.

Comparative Example 1 Of the compositions shown in Example 1, an oil phase was prepared in the same process as in Example 1 without adding a small amount of water. The viscosity of the system was increased by paddle stirring for 30 minutes. And 1 Pa · s for 1 hour. When this liquid phase was emulsified in the same manner as in Example 1, the properties of the obtained emulsion were 2200 mPa · s in viscosity and the particle size was 1 to 10 μm by microscopic observation.
m, and a small amount of coarse oil droplets was observed.

Example 5 An oil-in-water emulsion was prepared by the following composition and production method. <Composition> (1) Oil phase Oily component: 6 parts of dimethylpolysiloxane (SH200 30cs, manufactured by Toray Silicone) Nonionic surfactant: 2 parts of polyether-modified silicone (SH3775M, manufactured by Toray Silicone) Clay mineral: 2.2 parts of bentonite << Kunimine F Kunipia F (8% loss on drying) >> Polyhydric alcohol: propylene glycol 0.5 parts Pigment: titanium oxide 0.05 parts Transparent iron oxide 0.004 parts (2) Water phase Purified water 30 parts

<Production method> (1) Preparation of oil phase A clay mineral and a pigment are dispersed in the above-mentioned oil component, and a mixture obtained by previously mixing a nonionic surfactant and a polyhydric alcohol is added thereto. The mixture was mixed at 80 ° C. for 1 hour using a mixer. At this time, the viscosity of the oil phase was 70 mPa · s.

(2) Phase inversion emulsification 30 parts of the above aqueous phase were divided into 20 parts each of 1.5 parts, and 1.5 parts were added to the oil phase in the azihomomixer and stirred for 5 minutes each. When about 3 parts were added, the viscosity of the system increased, and after 18 parts, the viscosity of the system gradually decreased. The properties of the emulsion at the time when all the aqueous phases were finally mixed were 960 mPa · s in viscosity, the particle diameter was about 1 to 5 μm by microscopic observation, and a clean emulsion without oil floating was obtained. .

Example 6 Using an oil phase and an aqueous phase prepared with the same composition as in Example 5, phase inversion emulsification was carried out as follows. First, 30 parts of the aqueous phase was divided into 5 parts (1 part, 1 part, 1 part, 20 parts, 7 parts), and each aqueous phase was added using an azihomomixer in the same manner as in Example 5, and then stirred for 10 minutes. did. After the addition of the fourth 20 parts of the aqueous phase, the mixture was stirred for 20 minutes using an agitator and a homomixer in combination. The state of the viscosity of the system was about 80 Pa · s at the maximum. When all the aqueous phases have been finally mixed, the emulsion has a viscosity of 19
The particle size was 00 mPa · s, the particle size was about 1 to 6 μm when observed with a microscope, and a clean emulsion without oil floating was obtained.

Example 7 An oil-in-water emulsion was prepared by the following composition and production method. <Composition> (1) Oil phase Oil component: Vegetable squalane 6 parts (Phytosqualane manufactured by Iwase Cosfa) Nonionic surfactant: Polyoxyethylene (12) 2.2 parts Diisostearate (Nippon Emulsion 600di- IS) Clay mineral: bentonite 2.5 parts << Kunimine F Kunipia F (drying loss 8%) >> Polyhydric alcohol: 1,3-butylene glycol 0.7 parts (2) Aqueous phase Purified water 30 parts

<Manufacturing Method> (1) Preparation of Oil Phase A clay mineral is dispersed in the above oil component, and a mixture obtained by mixing a nonionic surfactant and a polyhydric alcohol in advance is added thereto. And mixed at 70 ° C. for 1 hour. At this time, the viscosity of the oil phase was 85 mPa · s.

(2) Phase inversion emulsification The above aqueous phase (30 parts) was divided into 10 parts each of 3 parts, added to the oil phase in the azihomomixer (3 parts each), and stirred for 10 minutes to perform phase inversion emulsification. . The properties of the obtained emulsion were 3400 mPa · s in viscosity and the particle size was 1 to 6 μm by microscopic observation.
m, and a clean emulsion without oil floating was obtained.

Example 8 An oil-in-water emulsion was prepared by the following composition and production method. <Composition> (1) Oil phase Oil component: 6 parts of isopropyl myristate (IPM-EX manufactured by Nikko Chemicals) Nonionic surfactant: 2.4 parts of polyoxyethylene (3) glyceryl monoisostearate (manufactured by Nippon Emulsion) GWIS-103) Clay mineral: bentonite 2.4 parts {Benger FW (7.5% loss on drying) manufactured by Toyohyun Yoko Co., Ltd.} Polyhydric alcohol: propylene glycol 0.7 part (2) Aqueous phase Purified water 30 parts

<Manufacturing Method> (1) Preparation of Oil Phase A clay mineral is dispersed in the above oily component, and a mixture obtained by previously mixing a nonionic surfactant and a polyhydric alcohol is added thereto. And mixed at 60 ° C. for 1 hour. At this time, the viscosity of the oil phase was 110 mPa · s.

(2) Phase inversion emulsification 30 parts of the above aqueous phase were divided into 20 parts each of 1.5 parts, and 1.5 parts were added to the oil phase in the above azihomomixer, and the mixture was stirred for 5 minutes, respectively. Emulsification was performed. The properties of the obtained emulsion were 3520 mPa · s in viscosity and the particle size was 1 by microscopic observation.
７7 μm, and a clean emulsion without oil floating was obtained.

Comparative Example 2 An oil phase was prepared in the same manner as in Example 5 except that the polyhydric alcohol was omitted. At this time, the viscosity of the oil phase was 300 Pa · s. 30 parts of the aqueous phase was added to this oil phase at a time and emulsification was carried out with an azihomomixer.
A uniform emulsion was not obtained.

[0038]

According to the method of the present invention, an oil-in-water emulsion which is fine and excellent in stability can be produced, and it is particularly advantageous since a clay mineral which has not been subjected to organic modification can be used as a raw material. The oil-in-water emulsion obtained by the method of the present invention can be used for a wide range of uses such as cosmetics and detergents. (A) When a small amount of water is used, not only can the viscosity of an oil phase formed by mixing an oily component, a nonionic surfactant and a clay mineral be increased, but also when an equilibrium is reached. Can be further increased as compared with the case where no water is used. Also,
(B) When a low molecular weight polyhydric alcohol is used, the viscosity of an oil phase formed by mixing an oil component, a nonionic surfactant and a clay mineral is excessively increased, and the fluidity is lost. It is particularly effective when the ratio is small, and even with such a ratio, it is possible to produce a fine oil-in-water emulsion while ensuring fluidity. In this case, the oil-in-water emulsion has an advantage that the effect of protecting the oily component is enhanced.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takumi Tsuruoka 1-3-7 Honjo, Sumida-ku, Tokyo Inside Lion Corporation (72) Inventor Tomoko Amasu 1-3-7, Honjo, Sumida-ku, Tokyo No. Inside Lion Corporation (72) Inventor Keiichi Nagai 1-3-7 Honjo, Sumida-ku, Tokyo Lyon Corporation (72) Shoji Matsunaga 1-3-7 Honjo, Sumida-ku, Tokyo Layo 4C076 AA17 DD07 DD28 DD38 EE27 EE53 FF43 GG45 4C083 AB051 AB232 AB242 AB441 AB442 AC022 AC111 AC122 AC132 AC352 AC402 AC422 AD152 AD162 BB04 BB11 DD33 FF01 4G065 AA01 AB01X AB05AB ABX AB13 AB33 AB BB01 BB03 CA03 DA02 DA08 FA01

Claims (2)

[Claims] 1. A viscous oil phase in which a clay mineral is dispersed is prepared by mixing at least an oil component, a nonionic surfactant, a clay mineral and a small amount of water. A method for producing an oil-in-water emulsion, comprising mixing and emulsifying. 2. A low-viscosity oil phase in which a clay mineral is dispersed by mixing at least an oil component, a nonionic surfactant, a clay mineral and a polyhydric alcohol having a low molecular weight. A method for producing an oil-in-water emulsion, which comprises gradually adding an aqueous phase to perform phase inversion emulsification.