JPS63126541A - Low-water content o/w type emulsion and its production - Google Patents

Abstract

PURPOSE:To micronize the particles and to improve the stability of the title emulsion by mixing 100pts.wt. oil phase, 15-30pts.wt. water phase, and 10-30 pts.wt. mixed phase of a polyol and a surfactant to prepare the low-water content O/W type emulsion. CONSTITUTION:One hundred pts.wt. oil phase, 15-30pts.wt. water phase, and 10-30pts.wt. mixed phase of the polyol and the surfactant are separately frozen. The frozen material are crushed under frozen conditions and pulverized, and then the mixture of the still frozen fine particles is heated or pressed to produce the low-water content O/W type emulsion. A cetyl 2-ethylhexanoate, isopropyl myristate, etc., are used as the oil phase. Besides, glycerin, sorbitol, etc, can be exemplified as the polyol to be used as the component of the mixed phase.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides an O/W emulsion with fine and uniform particles and a low water content with excellent stability, and the low water content 9
The present invention relates to a method for easily producing an O/W type emulsion, and the low water molecule FIO/W type emulsion of the present invention is particularly suitable for use in the production of cosmetics such as creams and milky lotions.

[Conventional technology and its problems]

Generally, emulsification methods for obtaining uniform emulsions with fine particles include a phase inversion (reaction) emulsification method and a gel emulsification method using a nonionic surfactant.

The phase inversion emulsification method described above is capable of emulsifying a wide range of oils, and by using an ionic surfactant, stable emulsions can usually be obtained. However, with this method,
Because the physical properties of emulsions depend on mechanical shear,
In order to obtain an emulsion with fine particles, it is necessary to apply strong shearing force.

In addition, in the gel emulsification method using a nonionic surfactant mentioned above, the nonionic surfactant is dissolved in a water-soluble solvent or a water-soluble solvent with an aqueous phase added, and the surfactant is continuously By forming a phase and gradually adding oil to the continuous phase, a gel-like emulsion is obtained, and water is further added to this gel-like emulsion to obtain an OZW type emulsion. However, although it is possible to obtain a fine emulsion with uniform particles using this method, the general tendency of nonionic surfactants is that they are temperature dependent, and an oil-in-polyol gel (0/P gel) is formed during the process. Alternatively, the manufacturing conditions for oil-in-surfactant gel (0/D gel) were severe.

That is, it has the disadvantage of being subject to manufacturing restrictions, and
Nonionic surfactants have the disadvantage of being limited in the oils that can be emulsified. In addition, the gel emulsification method described above has many limitations in the systems to which it can be applied.

In addition, the technology for making particles into fine particles has been rapidly progressing recently, and it is possible to make particles as small as 0.3 microns using ball mills, etc. However, conventional O/W emulsions
The water content is usually 60% or more, and the conventional emulsification method described above has not been able to obtain a low-moisture ○/W type emulsion with a water content of 30% or less.

In addition, the use of solid water such as ice and snow in dispersion systems is used in the cement industry to reduce the amount of water added to cement, but there is no attempt to use such technology in the cosmetics industry. No attempt has been made to do so.

[Means for solving problems]

The present inventors provide a low water content O/W emulsion with fine and uniform particles and excellent stability, and a method for easily producing the low water content O/W emulsion. As a result of various studies for the purpose of
It has been found that by utilizing phase change (liquid-solid) due to changes in temperature or pressure, it is possible to obtain an O/W emulsion with a lower moisture content than conventional O/W emulsions.

That is, the oil phase, the aqueous phase, and the mixed phase of polyol and surfactant are separately frozen and then crushed under frozen conditions to form fine particles, and then each fine particle under frozen conditions is By heating or pressurizing the mixture, a low-moisture 1) 0/W type emulsion that can achieve the above objectives can be easily obtained, although the solid-liquid transition temperatures of each phase are different. I found out.

The present invention was made based on the above knowledge, and the oil phase 10
The purpose of the present invention is to provide a low water content 0/W type emulsion consisting of 0 parts by weight, 15 to 30 parts by weight of an aqueous phase, and 10 to 30 parts by weight of a mixed phase of polyol and surfactant.

The present invention also provides a method for producing the low water molecule fi0/W emulsion, in which an oil phase, an aqueous phase, and a mixed phase of a polyol and a surfactant are separately frozen, and then The present invention provides a method for producing a low-moisture 1) 0/W type emulsion, in which the mixture of the fine particles is pulverized into fine particles, and then the mixture of the fine particles in a frozen state is heated or pressurized.

The low moisture 1ito/W type emulsion of the present invention will be described in detail below.

The oil phase constituting the emulsion of the present invention may be a liquid oil or solid fat with a high melting point, such as cetyl 2-ethylhexanoate, isopropyl myristate, isopropyl palmitate, 2-ethylhexyl valmitate, myristic acid, etc. Oils and fats such as octyldodecyl, isotridecyl stearate, jojoba oil, and olive oil can be used, and if necessary, these oils and fats may contain triglyceride, cholesterol, diglyceride, fatty acids with CI2 or more, fatty acids with C18 or more, which are generally difficult to emulsify. It is also possible to use oil-soluble substances in which 50% or less of oil-soluble substances such as waxes such as higher alcohols, batyl alcohol, beeswax, paraffin wax, ceresin, lanolin derivatives, vaseline, carnauba wax, and candelilla wax are dissolved.

Furthermore, as the aqueous phase constituting the emulsion of the present invention,
Water is used, and if necessary, add urea, amino acids,
It is also possible to use a solution in which 3% or less of a water-soluble substance such as an astringent is dissolved.

Further, as the polyol which is a forming component of the miscible phase constituting the emulsion of the present invention, glycerin, sorbitol, 1,3-butanediol, polyethylene glycol, ethylene glycol, dipropylene glycol, etc. can be used. Surfactants, which are another component of the , polyoxyethylene glycerin fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene phytosterol, polyoxyethylene polyoxybrobylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene castor oil/hydrogenated castor oil etc. can be used.

Further, the weight ratio (former/latter) of the polyol and the surfactant forming the mixed phase is 0°O1 to 0.1
It is preferable in terms of emulsion stability and reduction of skin irritation.

In the emulsion of the present invention composed of the above-mentioned oil phase, aqueous phase and mixed phase, the particle size of each particle in the emulsion is usually 1.0 μm or less.

The low water content 0/W type emulsion of the present invention described above can be easily produced by the above-described method for producing a low water content 0/W type emulcidin of the present invention.

Below, the manufacturing method of the present invention will be described in detail with respect to preferred embodiments thereof.

When carrying out the production method of the present invention, first, the oil phase, the aqueous phase, and the mixed phase are each separately frozen.

This freezing is usually carried out at a temperature of -50°C to -150°C.

Next, the frozen oil phase, aqueous phase, and mixed phase are each pulverized in a frozen state to form fine particles.

This pulverization can be performed using a ball mill or the like, and by this pulverization, the particle size of the fine particles of each phase is preferably reduced to 1.0.
It should be less than μ, especially less than 0.5 μ.

Next, the finely divided oil phase, aqueous phase, and mixed phase are added to 15 to 3 parts by weight of the aqueous phase per 100 parts by weight of the oil phase.
0 parts by weight and 10 to 30 parts by weight of the mixed phase to obtain a mixture of fine particles.

In addition, this mixture can also be obtained by mixing each frozen material in advance in the above-mentioned proportions before the above-mentioned pulverization, and then pulverizing them. Alternatively, after each material has been pulverized to some extent, the pulverized materials may be mixed and pulverized to a predetermined particle size.

Next, the above mixture is heated or pressurized to melt the continuous phase to obtain a dispersion system in which a solid oil phase is dispersed in the continuous phase.

The above heating is performed until the temperature of the above mixture reaches 120 to 20°C, preferably 110 to 10°C, and this temperature is maintained at 5°C.
It is preferable to raise the temperature in 20 minutes.

The pressurization is preferably carried out so that the mixture is kept at a pressure of 1.1 atm or higher, preferably 1.1 to 5 atm, and is preferably increased to this pressure over a period of 5 to 20 minutes. .

The obtained dispersion system has a liquid crystal structure due to the continuous phase being dissolved by the above-mentioned heating or pressurization, and in this state, the surface (interfacial) tension is approximately zero.

Next, the above dispersion system is stirred to further refine the oil phase.

Since the above-mentioned dispersion system has a surface (interfacial) tension of approximately 0 as described above, by this stirring, the oil phase can be further refined and dispersed well in the continuous phase without agglomeration.

Thereafter, the above-mentioned dispersion system is heated or pressurized again to melt the oil phase and stirred to obtain the low water content OZW type emulsine of the present invention.

The above-mentioned heating may be carried out until the temperature of the above-mentioned dispersion system reaches 40 to 50°C, and the above-mentioned pressurization is performed until the above-mentioned dispersion system reaches a temperature of 1.1 atm or more, preferably 1.1 to 2.0 atm. You should do it in a way that puts you in the right position.

The low water content OZW type emulcidin of the present invention obtained as described above has a particle size of each particle in the emulsion of 0.5 to 0.
It has a diameter of about 1 μm, has better high temperature stability than conventional 0/W emulsions, and has a water content of about 10 to 10 μm.It is particularly suitable for use in the production of creams and emulsions with a strong lynch feeling. .

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 [Oil phase] Jojoba oil 26.0 (%) Sorbitan monostearate 2.0 Setanol 1.2 Stearyl alcohol 0.8 Stearic acid 2.0 [Aqueous phase] Water 14.25 (%)
[Mixable phase] Cetyl phosphoric acid 1.5 (%) i-Arginine 0.7586% Glycerin 20.0 Octyldodecyl myristate 30.0 Hardened mustard oil 1.5 With the above blend, the oil phase, water phase, and polyol A miscible phase with a surfactant was prepared respectively.

Each phase is then frozen separately (temperature knee 1).
00° C.), and then ground in a ball mill under frozen conditions to obtain fine particles with a particle size of approximately 0.5 μm. Then,
While in a frozen state, the fine particles of each phase were mixed, and the mixture was further ground into fine particles having a particle size of approximately 0.1 μm. Thereafter, the mixture was heated to -10°C over 10 minutes, stirred at this temperature for 30 minutes, heated to 50°C while stirring, and then cooled to 30°C to form an O/W type. Mulberry cream invention product 1) was obtained.

Example 2 Using the same formulation as in Example 1, an oil phase, an aqueous phase, and a mixed phase of polyol and surfactant were prepared.

Each phase is then frozen separately (temperature knee I).
QQ°C), each was ground in a ball mill under frozen conditions to obtain fine particles with a particle size of approximately 0.5μ.
The microparticles of each phase in a frozen state were mixed, and the mixture was further pulverized to obtain microparticles with a particle size of approximately 0.1 μm. Thereafter, the mixture was pressurized to 2 atm at -50°C for 10 minutes, stirred at this pressure for 30 minutes, and then increased to 3 atm while stirring, then heated to 30°C, and heated to O/ A W-type mulberry cream invention product 2) was obtained.

Comparative Example 1 Using the same oil phase, water phase and mixed phase as in Example 1, an O/W type mulberry cream (comparison product) was produced by a conventional phase inversion emulsification method.

The emulsification state and stability of the present invention product 1.2 and the comparative product obtained in Example 1.2 and Comparative Example 1, respectively, were evaluated, and the particle size of each particle in the emulsion was measured. These evaluation results and measurement results are shown in the table below. The stability in the table below was evaluated after storage at room temperature for 7 days.

Note] Evaluation: ◎...Excellent, O...Good, △...Good It is a low water content O/W type emulsion with excellent properties, and can be particularly suitably used in the production of cosmetics such as creams and milky lotions.

Further, according to the manufacturing method of the present invention, the low water content 0/W type emulsion of the present invention described above can be easily manufactured.

Claims (8)

[Claims] (1) A low water content O/W emulsion consisting of 100 parts by weight of an oil phase, 15 to 30 parts by weight of an aqueous phase, and 10 to 30 parts by weight of a mixed phase of polyol and surfactant. (2) The low water content O/ according to claim (1), wherein the weight ratio (former/latter) of the polyol and surfactant forming the miscible phase is 0.01 to 0.1. W type emulsion. (3) The low water content O/ according to claim (1), wherein each particle in the emulsion has a particle size of 1.0μ or less.
W type emulsion. (4) The oil phase, the aqueous phase, and the mixed phase of polyol and surfactant are separately frozen and then crushed under a frozen state to form fine particles, and then each fine particle under the frozen state is heating or pressurizing a mixture of low moisture content O
/Method for producing W-type emulsion. (5) The low water content O/ according to claim (4), which is pulverized so that the particle size of the fine particles is 1.0μ or less.
Method for producing W-type emulsion. (6) The low water content O/ according to claim (4), wherein heating is performed until the mixture of fine particles reaches -20 to 20°C.
Method for producing W-type emulsion. (7) A method for producing a low water content O/W emulsion according to claim (6), which requires 5 to 20 minutes for heating. (8) The method for producing a low water content O/W emulsion according to claim (4), wherein the pressurization is carried out so that the mixture of fine particles is placed in a state of 1.1 atm or higher.