JPS6135967B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to skin cosmetics. More specifically, it relates to a new emulsifier/oil obtained by adding appropriate amounts of alkylene oxide and ethylene oxide to higher alcohols, which has the property of being difficult to remove from the skin under normal conditions of use, but easy to remove under certain conditions (for example, when bathing). The aim is to obtain emulsified skin cosmetics that have the following properties. Cosmetics such as emulsions and creams are generally made by emulsifying oils such as liquid paraffin, solid paraffin, petrolatum, higher fatty acids, higher alcohols, animal and vegetable oils, mineral oils, and synthetic oils, water, and a suitable surfactant. There are various types depending on the combination of oil and surfactant, ranging from those with a high oil content to those with a low oil content. Conventionally, emulsified cosmetics have been widely produced by emulsifying the aforementioned oil and water using a nonionic surfactant. The nonionic surfactants used at this time are rarely used alone, and include hydrophobic polyhydric alcohol fatty acid esters and hydrophilic nonionic surfactants made by adding ethylene oxide to higher alcohols, higher fatty acids, polyhydric alcohol fatty acid esters, etc. It is common to use it in combination with an ionic surfactant. This method is easy to manufacture, the emulsion has good storage stability, and by changing the formulation composition, water-in-oil type,
Although it has some advantages, such as being able to produce both oil-in-water and oil-in-water emulsions, it is said that water-in-oil emulsions are difficult to remove, while oil-in-water emulsions are easy to remove. There are drawbacks. This drawback can be overcome to some extent by increasing the concentration of the emulsifier, but since hydrophilic nonionic surfactants are inherently skin irritating, they cannot be used in large numbers, and in practice it is difficult to eliminate the above drawbacks. I couldn't do it. Therefore, both water-in-oil and oil-in-water emulsions can be produced as new cosmetic raw materials, and both types of emulsions do not fall off in water at temperatures below 30°C during use. There was a desire for a compound that could be easily removed with hot water of 40°C or higher. As a result of intensive research, the present inventors found that the compound is an addition polymerized monohydric fatty acid alcohol, a lipophilic alkylene oxide, and a hydrophilic ethylene oxide, and the overall molecular weight and the number of addition polymerizations of ethylene oxide are within a certain range. It has been discovered that a certain compound has the above-mentioned properties and is excellent as a skin cosmetic. _The present invention _{has the} following general _formula : A is an alkylene group having 304 carbon atoms, a is the polymerization amount of alkylene oxide represented by AO and is an integer of 20 to 50, and b is the polymerization number of ethylene oxide in the range of 1 to 9 and (C ₂ H ₄ O) _b is an integer whose molecular weight is 15% or less of the total molecular weight. Raw material alcohols for the compounds used in the present invention include lauryl alcohol, myristyl alcohol, cetyl alcohol, oleyl alcohol, stearyl alcohol, coconut oil reduced alcohol, tallow reduced alcohol, rapeseed oil reduced alcohol, straight chain synthetic alcohols, etc. with 12 or more carbon atoms. 22 saturated or unsaturated straight chain higher alcohols are preferred. Preferred alkylene oxides exhibiting lipophilic properties include propylene oxide, butylene oxide, isobutylene oxide, tetrahydrofuran, etc. alone or in mixtures thereof. Add 20 to 50 moles of the alkylene oxide to the linear higher alcohol, and then add 1 to 9 moles of hydrophilic ethylene oxide to make the molecular weight less than 15% of the total molecular weight, or add ethylene chlorohydrin. The compound used in the present invention can be obtained by the reaction. The compound used in the present invention has the unique property of gelling or forming an extremely viscous emulsion when mixed with water at a temperature of 30°C or lower, and easily dispersing in water at a temperature of 40°C or higher. This characteristic appears only in the compound used in the present invention in which a higher alcohol is selected, the number of moles of lipophilic alkylene oxide added is limited, and then an appropriate amount of hydrophilic ethylene oxide is added. Raw material alcohols other than those shown in the present invention, such as methanol, ethanol, alcohols with side chains, etc., cannot produce stable emulsions or are easily dispersed in water at any temperature; It cannot be used because only emulsions that are not dispersed at all can be obtained. The amount and order of addition of lipophilic alkylene oxide and hydrophilic ethylene oxide are also very important; outside the scope of the present invention, the above-mentioned disadvantages may cause skin irritation, which is undesirable. The product of the present invention satisfies all other properties required as a cosmetic raw material, such as low irritation to the skin, no color or odor, and long-term stability. When the product of this invention is used in cosmetics, various emulsions ranging from milky lotions to waxes can be obtained, but in order to obtain emulsions that are cream-like or harder, propylene oxide is added to an alcohol with 14 to 22 carbon atoms. It is most desirable to use a compound in which 20 to 50 moles of ethylene oxide are added and 3 to 9 moles of ethylene oxide are added. Next, production examples of compounds used in the present invention will be shown. Production Example 1 1370g of a compound prepared by adding 20 moles of propylene oxide to myristyl alcohol was placed in a four-necked flask with an internal volume of 5, and after alcoholate using 25g of metallic sodium, 90g was added at 80 to 90℃.
of ethylene chlorohydrin was added dropwise over 1 hour.
After aging for 1 hour, unreacted chlorohydrin was distilled off at 100 to 110°C and below 30 mmHg, and the generated common salt was separated, and the resulting product had the structural formula: C ₁₄ H ₂₉ O−(C ₃ H ₆ O) ₂₀ −
(C ₈ H ₄ O) ₁ - Compound represented by H (Sample No.
), 1380g was obtained. Production example 2 Take 15g of caustic potash in an autoclave with an internal volume of 5 and catalyze it with 270g of stearyl alcohol, and after purging with nitrogen gas, heat at 100-150℃, 1.0-7.0Kg/
Under a pressure of cm ² 2350 g of propylene oxide were added followed by 230 g of ethylene oxide. Neutralize the catalyst by adding phosphoric acid, separate the formed crystals, and convert to C ₁₈ H ₃₇ O−(C ₃ H ₆ O) ₄₀ −(C ₂ H ₄ O) ₅ −
2770 g of a compound corresponding to H (sample 3) was obtained. Thereafter, the compounds shown in Table 1 were obtained in the same manner as in Production Example 2. Example 1 The following tests were conducted on each of the samples No.-1 to No.-12 in Table 1. Heat 15 g of sample, 5 g of solid paraffin, and 30 g of liquid paraffin to 60°C and stir until uniform. While stirring, 50 g of water at 60°C was gradually added to form an emulsion. (1) The emulsification state was determined using the following criteria. 〇 The cream state is maintained even after 7 days have passed. △ The fluid emulsified state is maintained even after 7 days have passed. × The emulsification will be destroyed within 7 days. (2) Using the produced emulsion, a 24-hour closed patch test was conducted on the upper arms of five men and five women, and the skin irritation was determined according to the following criteria. 〇 No abnormality is observed. × Some kind of abnormality is observed (3) Ease of washing off was tested as follows. Apply the sample to two pieces of cloth, and apply 250 ml to one piece of cloth.
℃, wash the other piece with water at 40℃, dry it,
It was compared with Planck and judged based on the following criteria. 〇 It does not fall off with water at 25℃, but does fall off with water at 40℃. × Does not fall in both 25℃ water and 40℃ water, or falls in both. The results are shown in Table 1.

[Table] As is clear from Table 1, the product of the present invention, No.
-1 to No.-7 satisfy all points of emulsification state, skin irritation, and ease of washing, but comparative products No.-8 to
It can be seen that No.-12 has poor performance. Example 2 An all-purpose cream was made using the following formulation. Compound of sample No. 3 16% (weight) Liquid paraffin 25〃 Solid paraffin 4〃 Propylene glycol 4〃 Stearic acid 3〃 Glycerin monostearate 8〃 Purified water 40〃 Fragrance, preservative appropriate amount Ingredients other than water 60 Stir at ℃ until homogeneous. Gradually add water at 60°C while continuing to stir. After bottling, it was cooled to obtain a glossy white cream. This cream was stable at 0 to 50°C and satisfied all three criteria of Example 1. Example 3 A milky lotion was prepared using the following recipe. Compound of sample No. 2 14% (weight) Isostearyl alcohol 2〃 Glycerin monostearate 2〃 Glycerin 2〃 Liquid paraffin 5〃 Purified water 75〃 Fragrance, preservative Appropriate amount Ingredients other than water were heated to 50℃. , stir until homogeneous. Gradually add water while continuing to stir. Cool to obtain emulsion. The obtained emulsion is -
It has fluidity even at 20℃ and is extremely stable. Furthermore, all three criteria shown in Example 1 were satisfied.

Claims (1)

[Scope of Claims] 1. A skin cosmetic containing one or more compounds represented by the general formula []. R-O-(AO) _a -(C ₂ H ₄ O) _b -H …………[] However, R is a saturated or unsaturated straight-chain alkyl group having 12 to 22 carbon atoms, and A is a carbon number 3 to 4 alkylene groups, a is the polymerization number of alkylene oxide represented by AO and is an integer of 20 to 50, b is the polymerization number of ethylene oxide and is in the range of 1 to 9, and the molecular weight of (C ₂ H ₄ O) _b is an integer that is less than or equal to 15% of the total molecular weight. 2. The skin cosmetic according to claim 1, wherein R is a saturated linear alkyl group having 14 to 22 carbon atoms, and A is an alkylene group having 3 carbon atoms.