JPH0576338B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention uses diglycerin, triglycerin, and monoether consisting of a combination of tetraglycene and a specific higher alcohol as a hydrophilic surfactant alone, or as necessary, with other hydrophilic/lipophilic surfactants. This article relates to a safe and stable oil-in-water emulsion composition that has almost no formalin elution or PH change, has excellent emulsifying power, and does not cause skin irritation, which can be obtained by applying it to an emulsion system in combination with be. Nonionic surfactants that have been commonly used as emulsifiers include glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, and polyoxyethylene. Examples include alkyl phenyl ethers and polyoxyethylene hydrogenated castor oil derivatives. These emulsifiers are
They can be divided into lipophilic surfactants that do not contain or have short polyoxyethylene chains and hydrophilic surfactants that have long polyoxyethylene chains. If a large amount of hydrophilic surfactant is mixed in with the HLB of 10 to 15, an oil-in-water (O/W) emulsion will be obtained, and if the proportion of lipophilic surfactant is increased, the HLB will be 4 to 6.
A water-in-oil (W/O) emulsion is obtained. Creating stable emulsions requires delicate adjustment of hydrophilicity and hydrophilic balance. In the case of nonionic surfactants, polyoxyethylene chains are used to achieve this adjustment. This makes it easy to control the ethylene oxide chain length, making it possible to
This is because it can fully meet the demands of HLB. However, surfactants with ethylene oxide added have drawbacks such as dioxane being generated during synthesis, formalin eluting due to oxidation over time, and pH shifting to acidic. Therefore, attempts have been made to solve this problem by adding antioxidants, but their use is not desirable from a safety standpoint. On the other hand, polyglycerin surfactants that incorporate polyglycerin as a hydrophilic group are also well known in view of the problems of formalin elution and PH change caused by ethylene oxide. For example, polyglycerol fatty acid ester, which is widely used in the food field, is a typical example. However, this polyglycerol fatty acid ester has a wide distribution of polymerization degree of polyglycerin in the hydrophilic group part and a wide distribution of the bond number of the alkyl group in the lipophilic group part, and it is difficult to evaluate various physical properties and emulsifying properties using this wide mixture. Because of this, it was expected that the surfactant ability and properties of original polyglycerol surfactants would be even higher. In order to prove this, the present inventors first synthesized a polyglycerol ether type compound in which the number of bonds of the alkyl group, which is the lipophilic group, to polyglycerin was suppressed, and as a result of investigation, it was found that polyglycerol chains (more than heptaglycerin)
It was discovered that a polyglycerol ether type compound having a polyglycerol ether type compound has an excellent surfactant ability, and a good oil-in-water emulsion can be obtained, and the patent application was filed. (Refer to JP-A-58-180406) However, the polyglycerol ether type compounds obtained in this way also lack emulsifying power when the polyglycerin chain length is shortened (below hexaglycerin). It is thought that there is a limit to obtaining an oil-in-water emulsion composition, such as the formation of a water-in-oil emulsion, and this is also supported by the patent of Gregoire, Karopitsy et al. Ta. However, the present inventors conducted various syntheses and studies to gain further knowledge about polyglycerin, and found that when polyglycerin, which has a small degree of glycerin polymerization distribution, is used in a polyglycerol ether type compound, conventional lipophilic emulsifiers We discovered that monoalkyl ether type compounds of di-, tri- and tetraglycerin, which had not been considered as such, have high hydrophilicity contrary to common sense and form very good oil-in-water emulsion compositions. The present invention was completed based on these findings. That is, the present invention provides (a) diglycerin and 12 carbon atoms.
Monoether of ~14 higher alcohols, (b) Monoether of triglycerin and higher alcohols having 12 to 20 carbon atoms, (c) Tetraglycerin and higher alcohols having 12 to 20 carbon atoms
This invention relates to an oil-in-water emulsion composition characterized in that it contains a surfactant containing a hydrophilic surfactant consisting of one or more monoethers selected from 24 monoethers with higher alcohols. be. The present invention will be explained in detail below. The higher alcohol applicable to the present invention includes:
There are saturated aliphatic alcohols, unsaturated aliphatic alcohols, and β-branched monohydric alcohols having 12 to 24 carbon atoms, such as lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, oleyl alcohol, elaidyl alcohol, and linoleic alcohol. rail alcohol, linolenyl alcohol, jojoba alcohol,
Examples thereof include 2-hexyldecanol, 2-heptylundecanol, 2-octyldodecanol, fine oxocol, and 2-decyltetradecanol. The above-described higher alcohol is reacted with diglycerin, triglycerin, and tetraglycerin to form the monoether according to the present invention, which is used as a hydrophilic surfactant. In order to obtain this, the HLB of the entire hydrophilic surfactant needs to be 10 or more.
For this reason, a certain combination range is required between the di- or tetraglycerin and the higher alcohol used. That is, in the case of diglycerin, a higher alcohol having 12 to 14 carbon atoms is preferably used, in the case of triglycerin, a higher alcohol having 12 to 20 carbon atoms is preferably used, and in the case of tetraglycerin, a higher alcohol having 12 to 24 carbon atoms is preferably used. and the above HLB range is satisfied. If higher alcohols, which are the reactive components of di- to tetraglycerin, have carbon atoms smaller than the above range, the surfactant ability will be insufficient, whereas if higher alcohols are used, a water-in-oil emulsion composition will be obtained. I get used to it. In addition, for the same reason, in order to prevent deviations in the above HLB range when other hydrophilic surfactants are used together, the content of monoether in the hydrophilic surfactant should be adjusted based on the total amount of hydrophilic surfactants. It is desirable that the amount is 80% by weight, preferably 90% by weight or more. By doing so, the strength of the emulsifying power of the monoether according to the present invention can be fully exhibited, and the characteristics of not generating formalin and having almost no change in PH can be fully exhibited. Here, preferable specific examples of the monoether according to the present invention include diglycerin monolauryl ether, diglycerin monomyristyl ether,
triglycerin monolauryl ether, triglycerin monocetyl ether, triglycerin monostearyl ether, triglycerin motooleyl ether, triglycerin monolyl ether, triglycerin mono-2-hexyldecyl ether, triglycerin mono-2-octyl dodecyl ether, Triglycerin monophaein oxocol ether, tetraglycerin monolauryl ether, tetraglycerin monomyristyl ether, tetraglycerin monostearyl ether, tetraglycerin monobehenyl ether, tetraglycerin monooleyl ether, tetraglycerin monojojoba alcohol ether, tetraglycerin mono- 2-octyldodecyl ether and the like. Regarding the degree of polymerization of glycerin used for the formation of monoethers, in the case of monoglycerin, in the higher alcohol range which is usually used for the synthesis of surfactants, the obtained monoether form is a water-in-oil emulsifier. On the other hand, if it is pentaglycerin or higher, its hydrophilicity becomes too strong, resulting in a decrease in emulsifying power and also making it difficult to industrially synthesize each polyglycerin with high purity. In the present invention, the above-mentioned hydrophilic surfactant containing a monoether as a main component is used alone or in combination with a normal lipophilic surfactant while adjusting the HLB, and this is used as a surfactant in the system. A good oil-in-water emulsion composition can be obtained by blending in the range of 0.5 to 10% by weight, preferably 2 to 7% by weight. However, when used in combination with a lipophilic surfactant,
In order to maintain the HLB range for forming an oil-in-water emulsion composition, the content of the hydrophilic surfactant in accordance with the type of monoether relative to the total amount of surfactant is also important. In other words, since glycerin has strong properties as a hydrophilic group, the HLB value increases from diglycerin monoether to tetraglycerin monoether, so depending on the type of monoether, the hydrophilic surfactant The content of the surfactants in the total surfactant can be changed. For example, when using a hydrophilic surfactant made of diglycerol monoether, 50% by weight or more, preferably 60% by weight or more of the total amount of surfactant is required; When using a surfactant, the total amount of surfactant
40% by weight, preferably 50% by weight or more, and in the case of tetraglycerin monoether or di-, tri-, tetraglycerin monoether mixed system, 30% by weight, preferably 40% by weight or more of the total surfactant amount is sufficient. becomes. There are no particular restrictions on the components other than the surfactant for forming the oil-in-water emulsion composition of the present invention, that is, water, oil, and various additional components, and all conventional components can be used. Also, when preparing an oil-in-water emulsion composition, the hydrophilic surfactant made of monoether according to the present invention can be used in the same manner as conventional hydrophilic surfactants. Here, a hydrophilic surfactant containing highly purified diglycerin monoether, triglycerin monoether or tetraglycerin monoether having such good oil-in-water emulsification ability has not been available in the past. . This is because conventional polyglycerin ether surfactants are usually produced by adding glycidol to higher alcohol under an alkali catalyst, or by adding epichlorohydrin to higher alcohol and then saponifying it with alkali to form higher alcohol ether. It was guiding me. These ethers synthesized using glycidol give complex mixtures, and in synthesis using epihalohydrins such as epichlorohydrin, halogen removal may be incomplete or complex products may be produced during the desalting reaction. It was difficult to purify it to a high degree of purity. Therefore, instead of adding glycidol or epichlorohydrin to higher alcohols, which has been done up to now, the present inventors condensed higher alcohols with diglycerin or triglycerin or their derivatives, or used higher alcohol glyceryl ethers or higher alcohols. A highly purified monoether is obtained by condensing glycidyl ether with monoglycerin, diglycerin, triglycerin, or a derivative thereof. Next, Synthesis Examples 1 to 1 of monoethers according to the present invention
Comparative synthesis example 1 using 4 and the conventional method is shown below. Synthesis Example 1 Diglycerin monolauryl ether 2.0 g (0.087 mol) of metallic sodium was added to 552 g (6.0 mol) of anhydrous glycerin to produce an alcoholate at 120°C. Heat this to 180℃ and, while stirring vigorously, add lauryl glycidyl ether.
194 g (0.8 mol) was added dropwise over 4 hours, and after the addition was completed, the reaction was continued for 2 hours under the same conditions. After cooling to room temperature, the upper layer was taken out and subjected to silica gel column chromatography, and the target product was obtained as a colorless to pale yellow liquid by fractionation using chloroform:methanol=95:5. Yield: 176g (66% yield). Synthesis Example 2 Triglycerin Monooleyl Ether 14 g (0.061 mol) of metallic sodium was added to 515 g (3.1 mol) of anhydrous diglycerin to produce an alcoholate at 120°C. Heat this to 180℃,
Oleyl glycidyl ether with vigorous stirring
196 g (0.6 mol) was added dropwise over 5 hours, and after the addition was completed, the reaction was continued for 2 hours under the same conditions. After cooling to room temperature, the upper layer was taken out and subjected to silica gel column chromatography, and the target product was obtained as a colorless to pale yellow liquid by fractionation using chloroform:methanol=95:5. Yield 118g (yield 40%). Synthesis Example 3 Tetraglycerin mono-2-hexyldecyl ether 0.8 g (0.035 mol) of sodium metal was added to 120 g (0.5 mol) of anhydrous triglycerin to produce an alcoholate at 120°C. Heat this to 180℃,
While vigorously stirring, 59.6 g (0.2 mol) of 2-hexadecyl glycidyl ether was added dropwise over 6 hours, and after the addition was completed, the reaction was continued for 2 hours under the same conditions. After cooling to room temperature, the upper layer was taken out and subjected to silica gel column chromatography to obtain a colorless target product by fractionation in a ratio of chloroform:methanol=9:1. Yield: 54g (50% yield). Synthesis Example 4 Tetraglycerin monooleyl ether 0.8 g (0.035 mol) of metallic sodium was added to 120 g (0.5 mol) of anhydrous triglycerin to produce an alcoholate at 120°C. Heat this to 180℃,
Oleyl glycidyl ether with vigorous stirring
32.4 g (0.1 mol) was added dropwise over 8 hours, and after the addition was completed, the reaction was continued for 2 hours under the same conditions. After cooling to room temperature, the upper layer was taken out and subjected to silica gel column chromatography, and the desired product was obtained as a colorless to pale yellow liquid by fractionation with chloroform:methanol=9:1. Yield 23.1g (yield 41%). Comparative Synthesis Example 1 Tetraglycerin oleyl ether mixture 0.1 g (0.004 mol) of metallic sodium was added to 134 g (0.5 mol) of oleyl alcohol to produce an alcoholate. Glycidol 148 at 135℃
g (2.0 mol) was added dropwise over about 8 hours. After the dropwise addition was completed, the reaction was continued for 3 hours under the same conditions. After neutralizing the product with hydrochloric acid, insoluble matter was separated and volatile matter was removed under reduced pressure to obtain a mixture containing tetraglycerol oleyl ether in the form of a yellow paste. Yield 215
g (yield 76%). It is common knowledge that the surfactant according to the present invention is a water-in-oil emulsion type or liposomal dispersant, including higher alcohol ethers of diglycerin or triglycerin, as well as higher alcohol ethers of tetraglycerin, by conventional methods. cover the
It is surprising that it is hydrophilic, has excellent emulsifying ability, and can give a fine oil-in-water emulsion. This is because, as mentioned above, conventional polyglycerol higher alcohol ether surfactants exhibit strong lipophilic properties due to the distribution of the addition forms of glycerin chains. Therefore, in the case of conventional diglycerin, triglycerin, or tetraglycerin higher alcohol ether, systems using this as a surfactant can only be used as a stabilizer for water-in-oil emulsions or as a liposomal dispersant. It was currently being used. This is because all of these contain unpolymerized glycerin ether compounds and because the polyglycerin chains are distributed, HLB becomes lipophilic. Furthermore, it has been extremely difficult to increase the purity of surfactants produced by such conventional methods through purification. Next, as an application of the oil-in-water composition of the present invention,
It can be used mainly in food and cosmetics, which require safety, as well as in a wide range of other fields. Here, in order to evaluate the emulsifying ability of the hydrophilic surfactant made of monoether according to the present invention, a comparative product was synthesized with diglycerol monolauryl ether and tetraglycerol monooleyl ether obtained in Synthesis Examples 1 and 4. Using the tetraglycerol oleyl ether mixture obtained in Example 1 and the ethylene oxide hydrophilic surfactant hexaethylene oxylauryl ether, which has an HLB value similar to that of diglycerin monolauryl ether, dodecane, a type of hydrocarbon, and water (Dodecane: water = 2:
An experiment was conducted to compare the emulsifying power of 8wt%).
The method used was to add water to each of the above surfactant/dodecane mixtures at 70°C. Furthermore, the amount of surfactant blended was unified to 3% by weight based on the total amount of the system. The average particle diameter and maximum particle diameter of the emulsion were measured by liquid phase sedimentation method. The results are shown in Table 1.

[Table] As shown in the results in Table 1, the hydrophilic surfactant made of monoether according to the present invention is capable of forming a good oil-in-water emulsion, contrary to conventional wisdom.
It has also been proven that it gives a finer emulsion than conventional ethylene oxide surfactants. Furthermore, tetraglycerin monooleyl ether (Synthesis Example 4), which is a monoether according to the present invention, and cetomacrogol, polysorbate 80, and hydrogenated castor oil ethylene oxide addition, which have been conventionally used as emulsifying or solubilizing agents for pharmaceuticals and cosmetics, were added. Table 2 shows the results of the formalin elution test (surfactant 1wt% aqueous solution).

[Table] Examples of the application of the oil-in-water emulsion composition of the present invention to cosmetics are shown below. Incidentally, the blending ratio is in weight %. Example 1 Emollient cream (1) Triglycerin monolauryl ether 2.0 Tetraglycerin monomyristyl ether
1.0 sorbitan monostearate 2.0 stearic acid 5.0 cetanol 3.0 squalane 10.0 beeswax 2.0 spermaceti 1.0 lanolin 2.0 preservative 0.2 fragrance 0.3 (2) propylene glycol 7.0 glycerin 4.0 purified water 60.5 (Method) Heat (1) and (2). The temperature shall be 70℃. Add (2) into (1) while stirring. After the reaction, homogeneously emulsify using a homomixer and cool to 30°C using a heat exchanger. Example 2 Emollient lotion (1) Latraglycerin monobehenyl ether 1.0 Triglycerin monooleyl ether 1.0 Bacyl alcohol 1.0 Lanolin 2.0 Cetanol 1.0 Squalane 10.0 Preservative Appropriate amount Fragrance (2) Propylene glycol 4.0 Sorbitol 4.0 Hyaluronic acid 0.5 Purified water 75.5 (Method) Heat (1) and (2) to 70℃. Add (2) into (1) while stirring. After finishing, homogeneously emulsify using a homomixer. After the reaction, cool to 30°C using a heat exchanger. Example 3 Emulsified foundation (1) diglycerin monomyristyl ether 1.0 triglycerin mono-2-octyl dodecyl ether 1.0 tetraglycerin monojojoba alcohol ether 1.0 stearic acid 4.0 glycerin monostearate 3.0 cetanol 1.0 squalane 7.0 2-octyl dodeca Noroleate 7.0 Preservative Appropriate amount (2) Purified water 55.0 Triethanolamine 1.0 Sorbitol 3.0 (3) Titanium oxide 8.0 Kaolin 5.0 Talc 2.0 Bentonite 1.0 Color pigment Appropriate amount (4) Fragrance Appropriate amount (Method) Mix pigment (3) Smash. Heat the aqueous phase (2) to 80°C and add (3) to disperse. Heat and dissolve (1) at 80°C, then gradually add to (2) and emulsify. Cool while stirring and add (4). Further cool to 30℃. Example 4 Ointment (1) Triglycerin monostearyl ether 2.0 Diglycerin monolauryl ether 1.0 Chimyl alcohol 1.0 Vaseline 20.0 Indomethacin 1.0 Preservative appropriate amount (2) Glycerin 5 Purified water 70 (Method) Performed in the same manner as in Example 1 Summer.

Claims (1)

[Claims] 1 (a) A monoether of diglycerin and a higher alcohol having 12 to 14 carbon atoms. (b) Monoether of triglycerin and higher alcohol having 12 to 20 carbon atoms. (c) Monoether of tetraglycerin and higher alcohol having 12 to 24 carbon atoms. An oil-in-water emulsion composition characterized in that it contains a surfactant including a hydrophilic surfactant consisting of one or more monoethers selected from the following. 2. The oil-in-water emulsion composition according to claim 1, wherein the content of monoether in the hydrophilic surfactant is 80% by weight or more based on the total amount of the hydrophilic surfactant. 3. The oil-in-water emulsion composition according to claim 1, wherein the content of the hydrophilic surfactant in the surfactant is 30% by weight or more based on the total amount of the surfactant. 4. The oil-in-water emulsion composition according to claim 1, wherein the surfactant is blended in an amount of 0.5 to 10% by weight based on the entire oil-in-water emulsion composition.