JP5552248B2 - Water-in-oil emulsion composition - Google Patents

Description

  The present invention relates to a water-in-oil emulsified composition, and particularly relates to realization of a high moisturizing effect and improvement of a beam effect after application.

  The emulsified compositions are roughly classified into an oil-in-water type (O / W) and a water-in-oil type (W / O), and further, an oil-in-water type (O / W / O), a water-in-oil-in-water type ( There are also multiple types such as (W / O / W). These have been conventionally used in skin care creams, emulsions, hair care creams, etc. in the cosmetics field, and as transdermal creams, etc. in the pharmaceutical field.

  Among them, a water-in-oil type emulsion composition in which the oil phase is the outer phase and the water phase is the inner phase efficiently contains oil-soluble active ingredients such as emollient oil, oil-soluble drugs, and UV absorbers on the skin. Since it can be developed, it is a dosage form suitable as a skin external preparation, and is superior to the oil-in-water type in this respect.

  The ratio of the inner aqueous phase obtained by dividing the amount of the inner aqueous phase component by the total emulsified composition has a great influence on the properties of the emulsion, and also in the cosmetics containing the emulsion. Specifically, in a water-in-oil emulsified composition utilized for creams and the like, it is possible to give a refreshing and good feeling when the internal water phase ratio is increased, and the internal water phase ratio is low and moist. It feels oily.

  In a normal water-in-oil emulsion composition, when the internal water phase ratio is increased, it becomes difficult to maintain stability at around 60%. This is because the water molecules that make up the emulsified particles in the inner aqueous phase migrate and are absorbed by other emulsified particles (Ostwal Dryening), and the emulsified particles are more This is because coalescence of the emulsified particles occurs due to a significant increase in the collision frequency. Therefore, it was difficult to stabilize the emulsion at an internal water phase ratio exceeding 70%, which is around the fine packing ratio (74%) of the hard spheres. In addition, since the emulsification system is thermodynamically non-equilibrium, in order to stabilize it so that it can be used industrially, the amount of emulsifier, the ratio of the internal water phase, the type and amount of the aqueous component, the oil content There were limitations on the use of types and amounts, types and amounts of other stabilizers.

  That is, it has been difficult to provide a water-in-oil emulsion composition having a high moisturizing effect on the skin, having a high internal water phase ratio suitable for enhancing usability and maintaining good stability. .

  On the other hand, a water-in-oil emulsion composition having a high internal water phase ratio has been developed by mainly using glyceryl monooleate as a surfactant (see, for example, Patent Document 1). However, the above emulsion has a refreshing usability and a high moisturizing effect, but it is difficult to give a feeling of elasticity after coating. Also, by using one or more surfactants selected from glyceryl monooleate, glyceryl monooleate, polyoxyethylene glyceryl monoisostearate, and solid oil, fresh usability and water transpiration suppression effect A water-in-oil emulsified composition has been developed (see, for example, Patent Document 2). However, it is difficult to give a feeling of elasticity after coating even in the above emulsion.

  Furthermore, a water-in-liquid emulsified composition having a high internal water phase ratio in which a discontinuous reverse micelle cubic liquid crystal filled with reverse micelles is used as an outer phase and water is taken in as emulsion droplets has been developed (for example, Non-Patent Document 1). reference). However, in this method, the types and amounts of surfactants and oils are remarkably limited, so that the practicality is poor and the storage stability is not satisfactory.

  In addition, an oil-in-water emulsion composition that gives a feeling of skin sticking by using polyvinyl alcohol as a coating agent has been developed (see, for example, Patent Document 3). However, when commonly used “partially saponified” polyvinyl alcohol is added to a water-in-liquid emulsified composition having a high internal water phase ratio, there is a problem that the stability is remarkably lowered.

JP 2007-153824 A JP 2008-24630 A Japanese Patent No. 3664465

Satsuki Kuribayashi, Oreoscience Vol.1. No.3, 247-254 (2001)

As a result of devising the surfactant used to increase the internal water phase ratio, the conventional method has a sticky feeling and has a problem in usability, and is stable while maintaining a high internal water phase ratio. In order to maintain the quality, the kind of oil to be blended is limited, and when it is used as a cosmetic, it is not always satisfactory in terms of quality.
The present invention has been made in view of the above-mentioned problems of the prior art, and is a water-in-oil emulsion composition having a high internal water phase ratio that has a good makeup and a fresh effect on the skin, and is high after application. It is an object of the present invention to provide a water-in-oil emulsion composition that also gives a moisturizing effect.

  As a result of intensive studies by the present inventors to solve the above-mentioned problems, by mixing using a specific polyvinyl alcohol having a high degree of saponification, the emulsion stability is very good and the makeup lasting is good. Furthermore, the present invention has been completed by finding that it has excellent usability such as a finish having a high moisturizing effect and feeling after application.

That is, the water-in-oil emulsion composition according to the present invention includes the following components (A), (B), (C), and (D), and further satisfies the following conditions (1), (2), and (3): Features.
Ingredients: (A) glyceryl isostearate, (B) aqueous component excluding polyvinyl alcohol having a saponification degree of 90 mol% or more , (C) oily component excluding glyceryl isostearate , (D) polyvinyl having a saponification degree of 90 mol% or more. The internal water phase ratio obtained by dividing the mass of the aqueous component of alcohol (1) component (B) by the sum of the mass of the aqueous component of component (B) and the oily component of component (C) is 70% or more. is there. (2) The amount of glyceryl monoisostearate contained in component (A) is 85% by mass or more based on the total amount of (A). (3) The amount of glycerin diisostearate and glycerin triisostearate as impurities contained in component (A) is less than 15% by mass with respect to the total amount of (A).

  In the water-in-oil emulsion composition, a phase equilibrium state obtained by mixing the component (A) and the component (B) is bicontinuous cubic liquid crystal and aqueous phase, or bicontinuous cubic liquid crystal. A multiphase state in which other phases and an aqueous phase coexist is preferable.

  Moreover, it is preferable that the water-in-oil emulsified cosmetic further contains the component (E) tetramethyltrihydroxyhexadecane.

Moreover, it is suitable for the said water-in-oil emulsion cosmetic that the mass of a component (A) is 0.1-5.0 mass% with respect to the composition whole quantity.
The water-in-oil emulsified cosmetic preferably contains a solid oil as the oil component of the component (C).

  In addition, in the water-in-oil emulsified cosmetic, the mass of component (D) polyvinyl alcohol is preferably 0.03 to 1 mass% with respect to the total amount of the composition.

  The water-in-oil emulsion composition according to the present invention is a composition obtained by containing glyceryl monoisostearate with few impurities, an aqueous component, an oil component, and polyvinyl alcohol having a saponification degree of 90 mol% or more. Thus, it is possible to provide a water-in-oil emulsified cosmetic that is a product, has a long makeup, has a high internal water phase ratio, and has a high moisturizing effect after application.

The water-in-oil emulsion composition according to the present invention comprises (A) glyceryl isostearate (containing 85 mass% or more of glyceryl monoisostearate), (B) an aqueous component excluding polyvinyl alcohol having a saponification degree of 90 mol% or more , ( C) An oil component excluding glyceryl isostearate , and (D) polyvinyl alcohol having a saponification degree of 90 mol% or more. Hereinafter, each component will be described in detail.

  The component (A) glyceryl isostearate has a high purity of glyceryl monoisostearate and can be provided by various known synthesis methods. According to the usual synthesis method, it is produced as a mixture of glyceryl monoisostearate, glyceryl diisostearate, and glyceryl triisostearate. As for the component (A) which comprises the water-in-oil type emulsion composition concerning this invention, it is desirable that the purity of the glyceryl monoisostearate contained is high. As a purification method of glyceryl monoisostearate, a molecular distillation method is usually used, but is not limited thereto.

  The glycerin fatty acid diester and glycerin fatty acid triester contained as impurities of the component (A) are less than 15% by mass relative to the total amount of the component (A). While glyceryl monoisostearate has a function as a surfactant (emulsifier), glyceryl diisostearate and glyceryl triisostearate exhibit oil-like behavior. Accordingly, when the purity of glyceryl monoisostearate is low, the emulsion behaves as if glycerin diisostearate and glyceryl triisostearate were blended as oil components in addition to the oil component of component (C). That is, the purity of glyceryl monoisostearate is low, and glycerin fatty acid diester and / or glycerin fatty acid triester contained as an impurity of component (A) as a kind of oil blended as an oil component of component (C) When it exceeds 15 mass% with respect to the whole quantity of (A), stability of an emulsion will be impaired. In addition, the purity of glyceryl monoisostearate can be measured by general methods such as gas chromatography (GC), gel permeation chromatography (GPC), and high performance liquid chromatography (HPLC).

  In addition, as a suitable compounding quantity of a component (A), it is 0.1-5.0 mass% with respect to cosmetics whole quantity, Preferably it is 0.3-2.5 mass%. If it is 0.1% by mass or less, the stability of the emulsion may be remarkably impaired, and if it exceeds 5.0% by mass, the usability may be inferior.

As the aqueous component of component (B), those that can be usually used for cosmetics, pharmaceuticals, and the like can be blended within a range that does not impair the stability of the emulsion. Examples of the humectant include 1,3-butylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, glycerin, diglycerin, xylitol, maltitol, maltose, D-mannitol and the like. Water-soluble polymers include gum-based polymers such as gum arabic, carrageenan, pectin, agar, quince seed (quince), starch, and alge colloid (brown algae extract), microbial polymers such as dextran and pullulan, collagen, and casein. Animal polymers such as gelatin, starch polymers such as carboxymethyl starch and methylhydroxypropyl starch, alginic acid polymers such as sodium alginate, vinyl polymers such as carboxyvinyl polymer (such as CARBOPOL), polyoxyethylene Polymers, polyoxyethylene polyoxypropylene copolymer polymers, acrylic polymers such as sodium polyacrylate and polyacrylamide, inorganic water-soluble polymers such as bentonite, aluminum magnesium silicate, and laponite It is below.
Examples of UV absorbers include benzoic acid UV absorbers such as paraaminobenzoic acid, anthranilic acid UV absorbers such as methyl anthramylate, salicylic acid UV absorbers such as octyl salicylate and phenyl salicylate, isopropyl paramethoxycinnamate, Cinnamic acid UV absorbers such as octyl paramethoxycinnamate and glyceryl mono-2-ethylhexanoate diparamethoxycinnamate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy Benzophenone ultraviolet absorbers such as -4-methoxybenzophenone-5-sulfonic acid, urocanic acid, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 4-tert-butyl-4′-methoxybenzoylmethane Etc.

Examples of the sequestering agent include sodium edetate, sodium metaphosphate, phosphoric acid and the like.
Examples of the antioxidant include ascorbic acid, α-tocopherol, dibutylhydroxytoluene, butylhydroxyanisole and the like.
Drugs include vitamin A oil, retinol, retinol palmitate, inosit, pyridoxine hydrochloride, benzyl nicotinate, nicotinamide, nicotinic acid dl-α-tocopherol, ascorbic acid magnesium phosphate, ascorbic acid 2-glucoside, vitamin D2 ( Ergocassipherol), dl-α-tocopherol 2-L ascorbic acid phosphate diester potassium salt, dl-α-tocopherol, dl-α-tocopherol acetate, pantothenic acid, biotin and other vitamins, allantoin, azulene and other anti-inflammation Agents, whitening agents such as arbutin, astringents such as zinc oxide and tannic acid, sulfur, lysozyme chloride, pyridoxine hydrochloride, γ-oryzanol and the like.
In addition to the above drugs being used in a free state, those capable of salt formation can be used in the form of an acid or base salt, and those having a carboxylic acid group can be used in the form of its ester.

As the oily component of component (C), those that can be usually used for cosmetics and pharmaceuticals can be used as long as the stability of the emulsion is not impaired. The liquid oil is preferably silicone oil, more preferably cyclic silicone oil. Examples of silicone oils include linear silicone oils such as dimethylpolysiloxane, methylphenylpolysiloxane, and methylhydrogenpolysiloxane, and octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. There are typical cyclic silicone oils.
In addition, about polar oil, it is desirable to mix | blend a small quantity in the range which does not impair the stability of an emulsion. Representative polar oils include cetyl octanoate, hexyl laurate, isopropyl myristate, octyl palmitate, isocetyl stearate, isopropyl isostearate, octyl isopalmitate, isodecyl isostearate, 2-ethylhexyl succinate, diethyl sebacate, etc. There are ester oils.
Nonpolar oils include hydrocarbon oils typified by liquid paraffin, squalane, squalene, paraffin, isoparaffin, isododecane, isohexadecane and the like.

  Moreover, it is suitable that the oil component of a component (C) contains solid oil. Solid oils include cocoa butter, palm oil, horse oil, hardened palm oil, palm oil, beef tallow, sheep fat, hardened castor oil, etc., paraffin wax (straight chain hydrocarbon), microcrystalline wax (branched saturated carbonization) Hydrogen), hydrocarbons such as ceresin wax, mole, montan wax, Fischer-Trops wax, beeswax, lanolin, carnauba wax, candelilla wax, rice bran wax (rice wax), gay wax, jojoba oil, nukarou, montan wax, kapok wax, Bayberry wax, shellac wax, sugarcane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, hard lanolin, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid poly Waxes such as tylene glycol and POE hydrogenated lanolin alcohol ether, higher fatty acids such as myristic acid, palmitic acid, stearic acid, behenic acid, and higher alcohols such as cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, cetostearyl alcohol Etc. are raised. In addition, 0.5-3 mass% is preferable with respect to the cosmetics whole quantity, and, as for the compounding quantity of solid oil content, More preferably, it is 1-2 mass%. When the blending amount of the solid oil is less than 0.5% by mass, the stability may be inferior, and when it exceeds 3% by mass, the spread of the cosmetic becomes heavy.

  The internal water phase ratio of the water-in-oil emulsion composition according to the present invention is 70% or more. If it is less than 70%, a refreshing feeling may not be obtained. Furthermore, in the present invention, it is possible to prepare a water-in-oil emulsion composition having a high internal water phase ratio of 80% or more, and it is possible to give a refreshing feeling to use. The internal water phase ratio is calculated by dividing the mass of (1) the aqueous component of component (B) by the sum of the mass of the aqueous component of component (B) and the oily component of component (C).

  It is known that cubic liquid crystals have four types of structures. Closed aggregate micelles or reverse micelles form cubic surfaces by discontinuous cubic liquid crystals and lipid bilayers that are three-dimensionally connected in cubic layers in continuous layers of oil or water, respectively. There is a bicontinuous cubic liquid crystal which is a bicontinuous structure arranged in the same manner. Bicontinuous cubic liquid crystals also have a reverse type in which the positions of water and oil are reversed. In the emulsified composition of the present invention, the phase equilibrium state obtained by mixing the aqueous component (B) and the component (A) is such that the bicontinuous cubic liquid crystal and the aqueous phase, or the bicontinuous cubic liquid crystal It is preferable to be composed of a combination of the component (A) and the component (B) so as to be in a multiphase state in which another phase and an aqueous phase coexist.

A bicontinuous cubic liquid crystal is a bimolecular film in which surfactants are infinitely associated and arranged in a cubic form. Appearance is transparent, optically isotropic, and presents a highly viscous gel. Bicontinuous cubic liquid crystal discriminating methods include judgment by appearance, creation of phase equilibrium diagram, electrical conductivity measurement, self-diffusion coefficient measurement by NMR, small-angle X-ray scattering, freeze fracture method Determined by observation with an electron microscope or the like.
As a method for discriminating the liquid crystal structure in the present invention, the following methods can be considered. First, after the aqueous components (A) and (B) are mixed well, a plurality of coexisting phases are separated by centrifugation. When a normal centrifugal separator is used, a processing time of several hours to several days may be required. If there is no coexisting phase and it is in a single phase, the whole is uniformly transparent. Bicontinuous cubic liquid crystals including the reverse type are transparent in appearance, optically isotropic, and exhibit a highly viscous gel. Optical isotropy can be determined from the fact that the sample is held while two polarizing plates are combined with a phase difference of 90 degrees and there is no light transmission. The appearance is transparent and optically isotropic, and the gel-like phase with high viscosity can be further identified by small-angle X-ray scattering. The scattering pattern of the bicontinuous cubic liquid crystal including the inverted type is √2, √3, √4, √6, √8, √9, or Ia3d for the structure called Pn3m. The peak ratio is √6, √8, √14, √16, √20.
As a simple alternative to small-angle X-ray scattering, H. Kunieda
As described in et al., J. Oleo Sci. vol. 52, 429-432 (2003), there is also a method of estimating the structure from the diffusion time using water-soluble and oil-soluble dyes.

  As the component (D) polyvinyl alcohol, commercially available polyvinyl alcohol that can function as a coating agent can be used, and those divided into several grades depending on the degree of polymerization and saponification are commercially available. Polymerization is usually indicated by measuring the viscosity of a 4% strength aqueous solution at 20 ° C. In the present invention, those having a low viscosity of about 4 cps to a high viscosity of about 70 cps can be used. However, the higher the degree of polymerization, the higher the strength of the film to be formed, and there is a tendency for the feeling of elasticity to be too strong or the viscosity of the water-in-oil emulsion composition to increase. Considering the viscosity that is easy to do. It is preferable to use polyvinyl alcohol having a degree of polymerization having a viscosity range of 15 to 40 cps.

  On the other hand, the degree of saponification is due to the difference in the rate of saponification of the acetyl group of polyvinyl acetate during the production of polyvinyl alcohol. In the present invention, if a saponification degree of 90 mol% or more is used, a stable water-in-oil emulsion composition can be produced. In addition, it is not preferable to use a saponification degree of less than 90 mol% because a water-in-oil emulsion composition having poor stability is obtained.

  The compounding quantity of polyvinyl alcohol is 0.03-1 mass% normally with respect to the water-in-oil type emulsion composition whole quantity, Preferably it is the range of 0.1-1.0 mass%. If the blending amount is less than 0.03% by mass, the effects of the present invention such as a feeling of elasticity will not be sufficiently exerted. If the blending amount exceeds 1% by mass, the viscosity will be too high, resulting in stickiness or reduced stability. Or it may be difficult to apply.

  In addition, the water-in-oil emulsion composition according to the present invention can be widely applied to cosmetics, pharmaceuticals, and quasi-drugs that have been conventionally applied to the outer skin. For example, whitening serum, milk, cream, pack, foundation, lipstick, eye shadow, eyeliner, mascara, face wash, spray, mousse, hair rinse, shampoo, dermatological ointment and the like.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Unless otherwise specified, the blending amount is expressed in mass% with respect to the system in which the component is blended.

Preparation Method Component (A) glyceryl isostearate (containing 85 mass% or more of glyceryl monoisostearate), component (C) oily component and other oil-soluble components are mixed and heated to about 40 degrees to dissolve. The aqueous component of component (B), polyvinyl alcohol of component (D) and other water-soluble components are mixed and dissolved. While the oil-soluble component parts are relatively strongly stirred (or heated), the water-soluble component parts are gradually added to prepare an emulsion. In some cases, the emulsion is prepared while heating both the oil-soluble component part and the water-soluble component part. When heated, the prepared emulsion is cooled while stirring.
Further, the purity of glycerin monoisostearate in the component (A) can be measured by a general method such as gas chromatography (GC), gel permeation chromatography (GPC), high performance liquid chromatography (HPLC). .
The internal water phase ratio of the water-in-oil emulsion composition obtained by the above preparation method is calculated by dividing the mass of water and water-soluble components by the total mass of water and water-soluble components and oil and oil-soluble components. The

Evaluation method of water-in-oil emulsified composition The compositions shown in Tables 1 to 6 below are evaluated on the basis of the following evaluation criteria for freshness, elasticity, non-stickiness, moisturizing effect, stability, and phase equilibrium. did.
1. Mizumizushi Ten professional panels applied a water-in-oil emulsified composition to the face and evaluated the feeling during use.
A: Nine or more of the 10 panelists answered fresh.
○: 7 to 10 out of 10 panelists answered fresh.
Δ: 5 or more and less than 7 out of 10 panelists are fresh.
X: Reply that less than 5 out of 10 panelists were fresh.

2. Beam effect Ten professional panels applied a water-in-oil emulsified composition to the face and evaluated the feeling of use during application.
A: Nine or more of the 10 panelists answered that there was a beam.
○: 7 to 10 out of 10 panelists answered that there was a beam.
Δ: 5 or more but less than 7 out of 10 panelists answered that there was a beam.
×: Less than 5 out of 10 panelists answered that there was a beam.

3. No stickiness Ten professional panelists applied a water-in-oil emulsion composition to their faces and evaluated the feeling of use during application.
○: 8 or more of 10 panelists answered that there was no stickiness.
Δ: 5 or more and less than 8 out of 10 panelists answered that there was no stickiness.
×: Less than 5 out of 10 panelists answered that there was no stickiness.

4). Moisturizing effect Ten professional panels applied a water-in-oil emulsion composition to the face and evaluated the feeling of use during application.
A: Nine or more of 10 panelists answered that there was a moisturizing effect.
○: 7 to 10 out of 10 panelists answered that there was a moisturizing effect.
Δ: 5 or more and less than 7 out of 10 panelists answered that there was a moisturizing effect.
X: Less than 5 out of 10 panelists answered that there was a moisturizing effect.

5. Stability The water-in-oil emulsion composition was stored at 25 ° C. and 40 ° C. for 1 month, and the stability was evaluated by comparing the hardness and appearance immediately after adjustment.
A: Under any storage condition, the decrease in hardness is 10% or less, and no change in appearance is observed.
◯: No change in appearance is observed under any storage conditions, but only a 10% or more decrease in hardness is observed when stored at 50 ° C.
◯: No change in appearance is observed under any storage conditions, but a hardness decrease of 10% or more is observed.
Δ: Some separation of water or oil is observed in appearance.
×: Separation of water or oil is observed in appearance within one month.

6). Phase equilibrium when components (A) and (B) were mixed After each component was sufficiently mixed, each phase was separated by centrifugation. Thereafter, the phase equilibrium was determined by observation with a polarizing microscope and small-angle X-ray scattering measurement.
A: Bicontinuous cubic liquid crystal, reverse hexagonal liquid crystal and aqueous phase coexist.
○: Bicontinuous cubic liquid crystal, reverse hexagonal liquid crystal, and other phases and water phases coexist.
X: Consists of a combination of phases other than bicontinuous cubic liquid crystal and reverse hexagonal liquid crystal.

（＊）：テトラメチルトリヒドロキシヘキサデカン

(*): Tetramethyltrihydroxyhexadecane

In the test examples 1-1 to 1-4 shown in Table 1 above, the present inventors adjusted the amount of (B) the aqueous component and (C) the oil component and changed the internal water phase ratio as appropriate. Various effects and evaluation of phase equilibrium in a conventional water-in-oil emulsion composition containing no alcohol were studied.
As is clear from the results of Test Examples 1-1 to 1-4, it is possible to maintain stability even at an internal water phase ratio of 70% or more, which was difficult in the prior art, and a bicontinuous cubic liquid crystal. It was confirmed that reverse hexagonal and aqueous phase coexisted. Also, as the internal water phase ratio increased, the freshness and stickiness were improved, but the beam effect could not be improved at all.

Therefore, the inventors fixed the blending amount of polyvinyl alcohol at 0.3% by mass and changed the degree of saponification while keeping the composition in a high inner aqueous phase as shown in Test Examples 1-5 to 1-9. Each composition was adjusted to each composition and examined.
As a result, when polyvinyl alcohol having a saponification degree of 90 mol% or more was selected, it was found that a water-in-oil emulsion composition having excellent emulsification stability as in Test Examples 1-8 and 4-9 was obtained. However, even if it is polyvinyl alcohol, when less than 90 mol% polyvinyl alcohol is selected and compounded (Test Examples 1-5 to 1-7), the amphiphilic ability of less than 90 mol% polyvinyl alcohol is high, which affects the interface. Giving a problem, the emulsion stability was lowered.
From the above results, as the polyvinyl alcohol used in the present invention, it is possible to use those having a saponification degree of 90 mol% or more, while maintaining a high stability in spite of a high internal water phase ratio, and It became clear that it was preferable for the preparation of a water-in-oil emulsion composition with a feeling of elasticity.

  And from the result of Test Example 1-10, it became clear that in the water-in-oil emulsion composition of the present invention, when tetramethyltrihydroxyhexadecane is further added, the stability is further improved.

In addition, in the conventional oil-in-water emulsion composition, even when polyvinyl alcohol having a saponification degree of about 80 to 90 mol%, which is referred to as “partial saponification type”, is used, the saponification degree of “complete saponification type” is 97 to 100 mol%. It was thought that there was no difference in the emulsifying ability and stability even when using polyvinyl alcohol.
However, as described above, in the water-in-oil type emulsion composition of the present invention, when polyvinyl alcohol having a saponification degree of 90 mol% or more is selected and blended, good stability is maintained and the feeling of swell is very high. It is understood that it is preferable.
Next, the present inventors proceeded with studies on a suitable purity of (A) glyceryl isostearate used in the present invention.

（＊）：テトラメチルトリヒドロキシヘキサデカン

(*): Tetramethyltrihydroxyhexadecane

As shown in Table 2, the blending amount of (A) glyceryl isostearate is 0.7% by mass, and the purity of glyceryl monoisostearate is adjusted to 95%, 85%, 70%, 45%, and the purity. The effects of water on the phase state and usability evaluation of water-in-oil emulsion compositions were investigated.
As a result, when the purity of glyceryl monoisostearate is 95% and 85% (Test Examples 2-1 and 2-2), the composition is excellent in emulsion stability, but when the purity becomes 70% ( Test Example 2-3) In the phase equilibrium, the bicontinuous cubic liquid crystal, the reverse hexagonal liquid crystal, and other phases other than water coexist, and the emulsion stability at low temperature was slightly reduced. When the purity further decreased to 45% (Test Example 2-4), the phase equilibrium became a phase other than the bicontinuous cubic liquid crystal and the reverse hexagonal liquid crystal, and the emulsion stability tended to further decrease.
Subsequently, the present inventors examined an improvement mechanism of the emulsion composition by a combination of glyceryl monoisostearate and phytantriol.

（＊）：テトラメチルトリヒドロキシヘキサデカン

(*): Tetramethyltrihydroxyhexadecane

As shown in Table 3, in Test Examples 3-1 to 3-5, the amount of component (A) was appropriately changed, and each evaluation was examined.
As a result, in Test Example 3-1, in which 0.05% by mass of component (A) is blended, the phase equilibrium becomes a phase other than bicontinuous cubic liquid crystals and reverse hexagonal liquid crystals, and the emulsion stability tends to be poor. It was. On the other hand, when 0.1% by mass or more of component (A) was added (Test Examples 3-2 to 3-5), it was revealed that excellent emulsion stability was obtained, but 6.0% by mass. When blended (Test Example 3-5), the results were inferior to freshness.
As mentioned above, it is understood that the suitable compounding quantity of (A) component is 0.1-5.0 mass%.
Subsequently, the present inventors proceeded with studies on a suitable blending amount of polyvinyl alcohol used in the present invention and other oily components that can be blended in the water-in-oil emulsion composition of the present invention.

（＊）：テトラメチルトリヒドロキシヘキサデカン

(*): Tetramethyltrihydroxyhexadecane

As shown in Table 4, one type of surfactant is fixed to glyceryl monoisostearate (90%), further fixed to polyvinyl alcohol having a saponification degree of 99 mol% or more, and the blending amount of this polyvinyl alcohol is appropriately adjusted. Then, each evaluation was examined (Test Examples 4-1 to 4-6).
As a result, Test Example 4-1, in which no polyvinyl alcohol was blended, was inferior in the beam effect, and Test Example 4-6, in which 1.5% by weight of polyvinyl alcohol was blended, was sticky and improved in emulsion stability. It became inferior. On the other hand, in Test Examples 4-2 to 4-5 in which the blending amount of polyvinyl alcohol was blended by 0.03 to 1.0% by mass, each evaluation was favorable and particularly excellent in terms of stability and beam effect. A water-in-oil emulsion composition was obtained.
As described above, in order to obtain a water-in-oil emulsion composition that has a high internal water phase ratio and excellent emulsification stability, not only has a high degree of saponification, but also an appropriate amount of polyvinyl alcohol can be added. It was important and it became clear that it is preferable that the compounding quantity of the polyvinyl alcohol mix | blended with the water-in-oil emulsion composition of this invention is 0.03-1.0 mass%.

In addition to the squalane and cetyl ethylhexanoate, the present inventors added petrolatum, which is a semi-solid oil, and a solid oil (paraffin / microcrystalline wax mixture) in addition to the liquid oil.
As a result, Test Examples 4-7 and 4-8, in which 1-2% by mass of the solid oil (paraffin / microcrystalline wax mixture) was blended, were compared with Test Examples 4-2 to 4-5 using only the liquid oil. It is understood that the moisturizing effect is even better. However, Test Example 4-9 in which 4% by mass of the solid oil was blended did not change the superiority of the moisturizing effect, but resulted in deterioration in freshness, sticky feel, and stability.
From the above results, it is understood that in the water-in-oil emulsion composition of the present invention, it is preferable in terms of the moisturizing effect that an oily component containing 1 to 2% by mass of the solid oil content to the whole composition is blended.

Examples of the present invention are shown below.
Example 1 Moisturizing cream (compounding ingredient) (mass%)
(1) Purified water The remainder (2) Salt 1.0
(3) Glycerin 5.0
(4) Glycerol isostearate (90% by mass of pure monoisostearate) 0.7
(5) Squalane 7.0
(6) Cetyl ethylhexanoate 2.5
(7) Vaseline 2.0
(8) (paraffin / microcrystalline wax) mixture 1.0
(9) Polyvinyl alcohol 0.3
(10) Tetramethyltrihydroxyhexadecane 0.3
(11) Perfume appropriate amount (production method)
Oil components (4) to (8), (10) and (11) are mixed and heated to uniformly disperse the oil phase. The aqueous phase added with (1) to (3) and (9) is mixed. The heated water phase was gradually added to the oil phase, and after uniformly dispersing with a homodisper, the emulsified particles were prepared and cooled with stirring to produce a moisturizing cream composed of a water-in-oil emulsion composition. The obtained moisturizing cream had good stability and good usability.

Claims (6)

A water-in-oil emulsion composition comprising the following components (A), (B), (C), and (D), and further satisfying the following conditions (1), (2), and (3):
Component: (A) Glycerol isostearate (B) Aqueous component excluding polyvinyl alcohol having a saponification degree of 90 mol% or more (C) Oily component excluding glyceryl isostearate (D) Polyvinyl alcohol having a saponification degree of 90 mol% or more Conditions: (1) The internal water phase ratio obtained by dividing the mass of the aqueous component of component (B) by the sum of the mass of the aqueous component of component (B) and the oily component of component (C) is 70% or more.
(2) The amount of glyceryl monoisostearate contained in component (A) is 85% by mass or more based on the total amount of (A).
(3) The amount of glycerin diisostearate and glycerin triisostearate as impurities contained in component (A) is less than 15% by mass with respect to the total amount of (A).   2. The composition according to claim 1, wherein the phase equilibrium obtained by mixing the component (B) and the component (A) is bicontinuous cubic liquid crystal and aqueous phase, or bicontinuous cubic liquid crystal and others. A water-in-oil emulsified composition characterized by being in a multiphase state in which an aqueous phase and an aqueous phase coexist.   3. The water-in-oil emulsion composition according to claim 1, further comprising component (E) tetramethyltrihydroxyhexadecane.   The composition in any one of Claims 1-3 WHEREIN: The mass of a component (A) is 0.1-5.0 mass% with respect to the composition whole quantity, The water-in-oil emulsion composition characterized by the above-mentioned. object.   The composition in any one of Claims 1-4 WHEREIN: A solid oil component is included as an oil-based component of a component (C), The water-in-oil emulsion composition characterized by the above-mentioned. The water-in-oil emulsion composition according to any one of claims 1 to 5, wherein the mass of the component (D) polyvinyl alcohol is 0.03 to 1% by mass relative to the total amount of the composition. A water-in-water emulsified composition.