JPS6314683B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an oil-in-water emulsion composition that has excellent emulsion stability and stability over time, has a glossy surface, and has excellent usability. As is well known, oil-in-water emulsion compositions obtained by reacting and emulsifying higher fatty acids and basic substances have been blended with various ingredients to provide cosmetics that blend well with the skin. Among these compositions, those that use organic amines, particularly triethanolamine, as basic substances are widely used because they blend well with the skin and create stable gels that are relatively resistant to fatty acid crystallization. However, triethanolamine is rarely allergic when used for a long period of time, and this has led to concerns about human safety. In view of these circumstances, reactive emulsion compositions using inorganic bases have recently attracted attention. Although inorganic bases do not have the human safety problems that triethanolamine has, they have a high PKa, so emulsified compositions using them have the disadvantage that fatty acid crystals tend to form. For this reason, higher alcohols such as cetanol stearyl alcohol have traditionally been used as emulsion stabilizing agents. Although the addition of higher alcohols is effective in preventing fatty acid crystallization, the amount of addition required to maintain a stable state is has the disadvantage of very high viscosity, and only narrow products can be obtained in terms of consistency, hardness, and feel when used. In other words, although adding higher alcohols can prevent fatty acid crystallization in areas with high viscosity,
When applied to products with low viscosity, especially products with a 30°C viscosity of 10,000 cps or less, products with good product stability cannot be obtained. The present inventors have conducted extensive research to solve the above-mentioned drawbacks of oil-in-water emulsion compositions obtained by reacting and emulsifying higher fatty acids and inorganic bases. When a mixed emulsifier of a salt consisting of a specific α-monoglycerin ether and a nonionic surfactant is blended,
To obtain an oil-in-water emulsion composition that suppresses crystallization of fatty acids even if the viscosity is extremely low, has good emulsification, odor and color stability over time, has a glossy surface, and has excellent usability. The present invention was completed after discovering that the composition is safe for the human body and can be applied to a wide range of cosmetics in terms of consistency, hardness, and texture. That is, the present invention is an oil-in-water emulsion composition characterized by containing a mixed emulsifier consisting of the following (A), (B), and (C), a liquid oil agent, and water. (A) A salt consisting of 1 to 5% by weight of a higher fatty acid and an inorganic base of 0.2 to 1.5 times the mole relative to the higher fatty acid (B) 0.3 to 6% by weight of a general formula CH ₂ OH・CHOH・CH ₂ OR (in the formula , R is a saturated aliphatic alcohol residue having 16 or more carbon atoms) α-monoglycerin ether (C) 0.5 to 4.0% by weight of a nonionic surfactant other than (B) Reacting a higher fatty acid with an inorganic base An example of an oil-in-water emulsion composition obtained by emulsification containing α-monoglycerin ether is oleyl-α-monoglycerin ether, although it is outside the scope of the claims of the present invention. Japanese Patent Publication No. 54-52734
Publication No.). However, oleyl-α-monoglycerol ether suffers from oxidative deterioration over time and has poor stability in odor, color, etc., and oil-in-water emulsion compositions containing it have poor stability over time. This is a big problem as it impairs the quality of the product. In this regard, the specific α-monoglycerin ether of the present invention has excellent quality stability, and the oil-in-water emulsion composition of the present invention obtained by combining it with a specific emulsifier is safe for the human body, especially the skin. It is stable in a wide viscosity range, especially in a low viscosity range, has a glossy surface, and has excellent usability, and is particularly excellent in odor and color stability. Next, the configuration and effects of the present invention will be explained. The essential components constituting the oil-in-water emulsion composition according to the present invention are a higher fatty acid, an inorganic base, a specific α-monoglycerin ether, a nonionic surfactant, a liquid oil agent, and water. Higher fatty acids react with inorganic bases to form salts and act as emulsifiers, such as saturated straight chain fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, eicoic acid, behenic acid, etc. Examples include saturated branched fatty acids such as isopalmitic acid, isostearic acid, etc., unsaturated fatty acids such as oleic acid, linoleic acid, etc., and fatty acid mixtures such as beeswax, lanolic acid, etc.
One or more of these may be used. Among these, mixed fatty acids in which a saturated straight chain fatty acid is combined with a saturated branched fatty acid or an unsaturated fatty acid are preferred.
The amount of this compound can be selected arbitrarily, but is generally about 1 to 5% by weight. Examples of the inorganic base include lithium hydroxide, sodium hydroxide, potassium hydroxide, and the like. One or more of these may be used. This product is blended in a molar ratio of about 0.2 to 1.5, preferably 0.3 to 0.8, per 1 part of the higher fatty acid. A specific α-monoglycerin ether is represented by the general formula CH ₂ OH・CHOH・CH ₂ OR (in the formula, R is a saturated aliphatic alcohol residue having 16 or more carbon atoms), such as cetyl-α-monoglycerin ether. (chimyl alcohol), stearyl-α
- monoglycerin ether (batylcol), monoglycerin ether with saturated linear alcohol residues such as behenyl-α-monoglycerin ether, isostearyl-α-monoglycerin ether, 2-hexadecyl-α-monoglycerin ether, 2- Octyl-dodecyl-α-monoglycerin ether, 2
-dodecyl-hexadecyl-α-monoglycerin ether, 2-octadecyl-docosyl-α-monoglycerin ether, etc., in which the alcohol residue is in the form of a saturated side chain. These α−
One or more monoglycerin ethers can be selected and used from those included in the above general formula. Among these, stearyl-α-
It is preferable to use monoglycerin ether or cetyl-α-monoglycerin ether alone or in combination. These particular α-monoglycerol ethers are safe for the skin and the results of the following test methods:
The three mixtures caused no primary irritation to human skin at all. (Test method) Apply the sample to a lint cloth with a diameter of 1.5 cm using the anterior arm or the flexor side of the upper arm, apply this to the test site, cover with a special bandage, and press the top with a bandage. Judgments are made after 24 and 48 hours. The study was conducted by 54 healthy people. The above specific α-monoglycerin ether is
It is blended in a range of 0.3 to 10% by weight. If it is less than 0.3% by weight, the emulsified composition will become stale and have no effect. Moreover, if it exceeds 10% by weight, it is also undesirable because it causes lumps. According to the present invention, stability over time, emulsion stability, etc. can be maintained well in the low viscosity range of 500 to 10,000 cps (30°C), and the amount added at this time is 0.3 to 6% by weight. The nonionic surfactant is selected from those other than the above-mentioned specific α-monoglycerin ethers, such as polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene glycol,
Polyoxyethylene polyoxypropylene alkyl ether, polyhydric alcohol fatty acid partial ester (polyhydric alcohol: glycol, glycerin, sorbitol, mannitol, pentaerythritol, sucrose, etc.), polyoxyethylene polyhydric alcohol fatty acid partial ester, polyoxyethylene fatty acid ester, polyglycerin fatty acid ester,
Polyoxyethylated castor oil, etc. can be mentioned. One or more of these can be used. Although the amount of this compound can be selected arbitrarily, it is generally about 0.5 to 4.0% by weight. Examples of liquid oils include liquid higher aliphatic alcohols (2-hexyldecyl alcohol, isostearyl alcohol, etc.), liquid ester oils (isopropyl myristate, pentaerythritol tetra-2-ethylhexanoate, trimethylolpropane diiso Stearate, propylene glycol monostearate, coconut oil, etc.), liquid hydrocarbon oils (liquid paraffin, squalane, etc.), and the like. One or more of these may be used. The amount of this compound added can be selected arbitrarily, but is generally about 1 to 70% by weight. The amount of water added is approximately 20-90% by weight. In addition to the above-mentioned essential components, the oil-in-water emulsion composition of the present invention may further contain a humectant, a thickener, a solid oil agent, and the like, if necessary. Of course, they must be used under qualitative and quantitative conditions that do not impair the purpose of the invention. Examples of humectants include propylene glycol, glycerin, dipropylene glycol, diglycerin, polyglycerin, polyoxyethylene glycol #300, #400, #1000, #1500, pentaerythritol, trimethylolpropane,
1,3-butylene glycol, hexylene glycol, polyoxypropylene glycol #200,
#400, sorbitol, sucrose, maltose, etc. One or more of these may be used. Examples of the thickener include polyvinyl alcohol, carboxyvinyl polymer, montmorillonite, and the like. Examples of solid oil agents include carnauba wax, candelilla wax, microcrystalline wax, petrolatum, solid paraffin, cetanol, and stearyl alcohol. In addition, appropriate amounts of known fragrances, preservatives, dyes, pigments, etc. may be added. As shown in the examples below, the emulsion composition according to the present invention has excellent emulsion stability in a wide viscosity range compared to conventional products, and in particular, even if the viscosity is extremely low, fatty acid crystals oxidation is suppressed and is stable over time. Therefore, the present invention has
In particular, it can be said that the emulsion composition is extremely useful cosmetically. Next, the effect of adding the specific α-monoglycerin ether blended in the present invention will be shown. Table 1 is
The state of the system when stearyl-α-monoglycerin ether is added to an aqueous soap solution obtained from higher fatty acids and inorganic bases is shown in comparison with cetanol, which has traditionally been used as an emulsion stabilizing agent. be. The formulation used in the test is as follows. [Formulation] Stearic acid 1.2% by weight Behenic acid 0.6 Isostearic acid 1.2 Potassium hydroxide 0.3 Ion exchange water 96.7-x Additives x

[Manufacturing method]

After heating and melting ~ at 80~85℃, increase the temperature to 70~
The temperature was adjusted to 75°C, and was added and mixed with stirring. On the other hand, ~ was heated and dissolved at 70 to 75°C, and the powder was uniformly dispersed using a dispersion machine, and then the mixture of ~ was gradually added to react and emulsify. When treated with an emulsifier, a uniform oil-in-water emulsion composition with emulsified powder of 1 to 2 μm was obtained. This was further cooled to 30°C. The emulsion composition thus produced was a liquid foundation with a glossy surface that was easily blended, easy to layer, and light in use. This product had a viscosity of 3500 cps at 30°C, and its emulsification, odor, and color remained stable even after one month at 0°C. On the other hand, for comparison, stearyl-α-
It was produced in the same manner as above except that monoglycerin ether 1.0% was replaced with cetanol 1.0%, but this product had a viscosity of 20,000 cps at 30°C, and the fatty acid crystallized after one month at 0°C. You can also see
The emulsification system was unstable. Example 2 Emulsion (formulation) Palmitic acid 1.0 Stearic acid 1.0 Squalane 10.0 Cetyl-α-monoglycerin ether 1.0 Glycerin monooleate 1.0 Polyoxyethylene (10) Glycerin monooleate 1.0 Fragrance 0.2 Preservative 0.2 Propylene glycol 5.0 Glycerin 5.0 Hydroxylation Potassium 0.1 Sodium hydroxide 0.1 Carboxyvinyl polymer 0.2 Ion exchange water to100 (Production method) After heating and dissolving ~ at 80~85℃, reduce the temperature to 70~
The temperature was adjusted to 75°C and , was added. On the other hand, ~
was heated and dissolved at 70 to 75°C, and the above mixture was gradually added thereto while stirring to react and emulsify. If processed with an emulsifying machine, the emulsified particles will be 1~
At 3μ, a uniform oil-in-water emulsion composition was obtained.
When this was further cooled to 30°C, it became an emulsion with a glossy surface that was easily absorbed and was easy to use. This product had a 30°C viscosity of 4900 cps, and remained stable in emulsification, odor, and color tone even after one month at 0°C. For comparison, palmityl-α-monoglycerin ether 1.0
% and 1.0% of cetanol was added in the same manner as above, but this product had a viscosity of 30,000 cps at 30°C and the emulsified system formed crystals over time and was unstable. Example 3 Emulsion [Formulation] Behenic acid 0.6 Stearic acid 1.2 Isostearic acid 1.2 Squalane 10.0 Cetyl-α-monoglycerin ether 0.3 Stearyl-α-monoglycerin ether
0.7 Glycerin monostearate 1.0 Flavor 0.2 Preservative 0.2 Propylene glycol 5.0 Glycerin 5.0 Potassium hydroxide 0.3 Carboxy vinyl polymer 0.5 Ion exchange water to100 [Manufacturing method] ~ was dissolved by heating at 80 to 85°C. after that,
The temperature was adjusted to 70-75°C and added. On the other hand, - was heated and dissolved at 70 to 75°C, and while stirring was continued, the mixture of - was gradually added to react and emulsify. When treated with an emulsifying machine, a uniform oil-in-water emulsion composition with small emulsion particles was obtained. When this was further cooled to 30°C, it became a milky lotion with a glossy surface and good blendability and ease of use. This product had a viscosity of 5300 cps at 30°C, and remained stable in emulsification, odor, and color tone even after one month at 0°C. On the other hand, for comparison, palmityl-α-monoglycerin ether 0.3
% and stearyl-α-monoglycerol ether
It was produced in the same manner as above except that 1.0% of cetanol was added instead of 0.7%, but the viscosity at 30°C was as high as 40,000 cps, and the emulsion system was unstable as crystals formed over time. Example 4 Cream [Formulation] Beeswax 3.0 Solid paraffin 5.0 Vaseline 10.0 Behenyl-α-monoglycerin ether 3.0 Squalane 30.0 Glycerin monostearate 2.0 Polyoxyethylene (15) sorbitan monostearate 2.0 Fragrance 0.2 Preservative 0.2 Propylene glycol 4.0 Potassium hydroxide 0.1 Ion exchange water to100 [Production method] After heating and dissolving ~ at 80~85℃, lower the temperature.
The temperature was adjusted to 70-75°C, and was added and mixed with stirring. On the other hand, - was heated and dissolved at 70 to 75°C, and while stirring was continued, the mixture of - was gradually added thereto to react and emulsify. When treated with an emulsifying machine, a uniform oil-in-water emulsion composition with emulsified particles of 1 to 3 microns was obtained. If this is further cooled to 30℃,
The result is a cream with a glossy surface that blends well and is easy to use. This product has a 30°C viscosity of approximately 50,000 cps and a hardness of 4 (card tension meter; pressure sensitive shaft diameter 8 mm, load
200g), and there is no emulsified odor even after one month at 0℃.
Both color tone was stable.

Claims (1)

[Scope of Claims] 1. An oil-in-water emulsion composition characterized by containing a mixed emulsifier consisting of the following (A), (B), and (C), a liquid oil agent, and water. (A) Salt consisting of 1 to 5% by weight of higher fatty acid and 0.2 to 1.5 times the molar amount of inorganic base to the higher fatty acid (B) 0.3 to 6% by weight General formula CH ₂ OH・CHOH・CH ₂ OR (Formula (wherein R is a saturated aliphatic alcohol residue with 16 or more carbon atoms)