JP2009227659A - Thread-like micelle-forming composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-soluble composition in which thread-like micelles are formed. <P>SOLUTION: A thread-like micelle-forming composition includes a phosphoric acid diester of tocopherol represented by chemical formula (I) and/or chemical formula (II) with ascorbic acid, and/or an alkali metal salt thereof, an alkali metal salt and water. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a water-soluble string-like micelle forming composition.

  Thickening gelling agents are widely used in cosmetics, pharmaceuticals, and other food and industrial applications. In addition to those related to the stability of the dosage form, such as retention of the dosage form and prevention of separation, handling is also possible. It is often used for the purpose of improving usability such as ease and feel. There are various types of thickening gelling agents that are actually used, and polymers, organoclay minerals, waxes, thickening polysaccharides, surfactants, and the like are used.

When these thickening gelling agents are used for external preparations such as cosmetics and pharmaceuticals, in addition to excellent thickening action, there are various requirements such as safety to the skin, stability to heat, and a good feeling to use. What satisfies the requirements is desired.
For example, a carbomer of a water-soluble polymer has high viscosity and thixotropy, but the viscosity decreases when the salt coexists, so that there are restrictions on the blending of the salt. In addition, when applied on the skin, there is a problem that the viscosity rapidly decreases due to salt on the skin. On the other hand, thickening polysaccharides such as xanthan gum are excellent in salt resistance, but have problems such as high thickening function, stickiness, and low thixotropic properties.

  In recent years, molecular aggregates called string-like micelles formed by surfactant molecules have attracted attention as thickening liquid compositions. It is known that the string-like micelle has a form in which surfactant molecules are self-assembled like a string, and has a specific behavior with viscoelasticity due to the entanglement of the string-like structures.

  In general, in a low concentration surfactant aqueous solution at a concentration at which micelle formation starts, that is, near a critical micelle concentration (cmc), spherical micelles are mostly formed, and viscoelasticity is not exhibited. However, an organic salt of a benzene derivative such as sodium salicylate or sodium p-toluenesulfonate is added to an aqueous cationic surfactant solution having a quaternary ammonium salt or pyridinium salt in a hydrophilic group. Thus, they act as inducers for forming string-like micelles and develop strong viscoelasticity (Non-Patent Document 1). However, many of the components used as the constituent components of these string-like micelles have antiseptic and bactericidal properties, and are often formerly designated components in the classification of cosmetic raw materials. That is, in terms of safety, it is never a desirable system, and it is difficult to use as a base material for external preparations such as pharmaceuticals and cosmetics.

  Patent Document 1 discloses a string-like micelle solution mainly composed of a nonionic surfactant such as a sucrose fatty acid ester as a thickening gelled composition that has improved the drawbacks in terms of safety. However, since the Kraft point of these compositions is as high as around 30 ° C., there is a problem that the surfactant is deposited and separated even in a 25 ° C. environment (Non-patent Document 2). Non-Patent Document 2 uses SDS, which is an anionic surfactant, to avoid this problem, but it is not desirable to use it from the viewpoint of irritation to the skin. The sucrose fatty acid ester to be used must have a high monoester purity, and if the monoesterification degree is low, it is easy to transfer to a lamellar liquid crystal, so that it is difficult to form stable string micelles ( Patent Document 1). In order to obtain a sufficient viscosity, approximately 10% by weight of a surfactant must be added. Therefore, it is difficult to use it for applications other than those that are temporarily exposed to the skin, such as cleaning agents, for example, skin care preparations. It was.

JP 2005-82650 A

Takeshi Yamamura; Toshiaki Kusaka; Eiichi Takatori; Masashi Inoue; Norio Nemoto; Kunihiro Ozaki; Toshiyuki Shikata; Tadao Odaka Journal of Japanese Society of Rheology 1991 19, 140. Hiromi Ando; Jun Shioguchi; Kenji Aramaki Abstracts of the 2nd Japan-Australia Symposium 60th Colloid and Interface Chemistry Symposium 2007, 53

  It is providing the composition which formed the string-like micelle.

As a result of diligent research to solve the above problems, the present inventors have completed a composition that forms string-like micelles exhibiting thickening that does not require or use a small amount of a surfactant that has been used in a large amount until now.
The main configuration of the present invention for solving the problems is as follows.
(1) (a) one or more selected from the following compounds (a1) to (a4), (b) an alkali metal salt, and (c) water, A composition characterized by comprising:
(A1): phosphoric acid diester compound of tocopherol and ascorbic acid represented by the following chemical formula (I)
[R ₁ and R ₂ in the formula each represent a hydrogen atom or a methyl group. ]
(A2): alkali metal salt of (a1) (a3): phosphoric acid diester compound of tocopherol and ascorbic acid represented by the following chemical formula (II)
[R ₁ and R ₂ in the formula each represent a hydrogen atom or a methyl group. ]
(A4): The composition according to (1), wherein the amount of the alkali metal salt (2) (a) in (a3) is 0.5% by mass or more.
(3) The composition according to (1) or (2), wherein the blending molar ratio of (a) :( b) is from 1: 4 to 1:60.
(4) The composition according to any one of (1) to (3), further comprising (d) a nonionic surfactant having an HLB of 3 or more and 12 or less.
(5) (d) is one or more selected from the group consisting of monoglycerol fatty acid esters, polyglycerol fatty acid esters having a polymerization degree of glycerol of 2 or more, and polyoxyethylene alkyl ethers. (4) The composition as described.
(6) A thickener comprising the composition described in any one of (1) to (5).
(7) A skin external preparation containing the composition according to any one of (1) to (5).
(8) Food / beverage products containing the composition described in any one of (1)-(5).

The composition in which the cord-like micelle of the present invention is formed exhibits a viscosity in a static state and exhibits a property of increasing fluidity when a force such as stirring is applied.
The composition of the present invention having this string-like micelle structure has thixotropic properties, and at the stage when the composition is taken on the palm, it can prevent dripping and fall due to the viscosity caused by the string-like micelle structure, When performing the application action, the cord-like micelle structure is collapsed and the viscosity is lowered, so that the application becomes easy. Moreover, since the string-like micelle structure is recovered again after application, it exhibits an excellent usage characteristic that it is difficult for the sagging drop from being applied. The cord-like micelle of the present invention has a high salt resistance and is hardly affected by the salt on the skin when applied to the skin.
Conventional packs that apply a thickening and moisturizing preparation directly to the skin have a problem that the stickiness may occur when the viscosity decreases due to the salt content on the skin, or when the viscosity is maintained by adding a large amount of polysaccharides. there were. If the composition which formed the string-like micelle of the present invention is applied, it is possible to provide a moisturizing pack agent that maintains viscosity and is not sticky and has a good feeling of use.
The composition forming the corded micelle of the present invention exhibits excellent gelling ability despite the small amount of surfactant used, and the antioxidant active ingredient is mainly used, so the antioxidant ability against the skin Is also expected. In addition, in a composition containing a component susceptible to oxidation, it can be expected to prevent oxidation of the oxidation component. Furthermore, since the surfactant is hardly contained in the composition, it is easy to ensure safety even if it is left on the skin.
By utilizing the thixotropic property of the composition having the cord-like micelle of the present invention, it can be used as an external preparation applied to the skin, a cosmetic, a pharmaceutical base, or a carrier. Alternatively, it can be used as a base for general adhesive coating agents. Or since it shows a gel form in a static state, it is a gel-like food and drink, and can provide a food and drink in a unique form that exhibits a dosage form transformation that exhibits fluidity by biting in the mouth.

The figure which shows the Maxwell model which shows the specific behavior peculiar to a string-like micelle. The graph which shows the G '((omega)) and G "((omega)) typical curve of a Maxwell model. The graph which shows the G 'curve of the string-like micelle solution of Example 12, and the graph of a G "curve. The eta 'curve of the string-like micelle solution of Example 12 is a graph. The graph which shows the Cole-Cole plot (G "vsG ') of the string-like micelle solution of Example 12. FIG. The graph which shows the G 'curve of the string-like micelle solution of Example 37, and the graph of a G "curve. The eta 'curve of the string-like micelle solution of Example 37 is a graph. The graph which shows the Cole-Cole plot (G "vsG ') of the string-like micelle solution of Example 37. FIG. Transmission electron micrograph of Example 12 Transmission electron micrograph of Example 37

The present inventors have used ascorbyl / tocopheryl phosphate or a salt thereof used as an anti-oxidant for cosmetics and the like to form a string-like micelle without using a surfactant that has been used in a large amount until now. In combination with a salt containing an alkali metal ion and a surfactant having a specific range of HLB as an inducing factor for the formation of string-like micelles, it has excellent viscoelastic behavior and anti-component properties. A composition having a string-like micelle structure, which is expected to have oxidation ability at the same time, was completed. This composition is also a novel thickening gelling agent.
The composition of the present invention contains a phosphoric acid diester compound of tocopherol and ascorbic acid represented by the chemical formula (I) and / or (II) and / or an alkali metal salt and an alkali metal salt thereof. The composition that forms is fundamental.
Furthermore, a nonionic surfactant having an HLB of 3 or more and 12 or less can be contained.

[Phosphate diester compound of tocopherol and ascorbic acid and alkali metal salt thereof] The phosphate diester compound of tocopherol and ascorbic acid used in the present invention is represented by the following chemical formula (I) or (II).

[R ₁ and R ₂ in the formula each represent a hydrogen atom or a methyl group. ]

[R ₁ and R ₂ in the formula each represent a hydrogen atom or a methyl group. ]

In Formulas I and II, when both R ₁ and R ₂ are methyl groups, α-tocopherol, R ₁ is a hydrogen atom, and R ₂ is a methyl group, β-tocopherol, R ₁ is a methyl group, and R ₂ is a hydrogen atom. In the case of γ-tocopherol and when R ₁ and R ₂ are both hydrogen atoms, it represents a phosphodiester compound of δ-tocopherol and ascorbic acid.
The compound of the chemical formula (I) or (II) is a divalent acid and can be used as an alkali metal salt. Examples of the alkali metal salt include sodium salt and potassium salt. When the number of moles of the compound of chemical formula (I) or (II) is 1, it is preferable to use a metal salt having an alkali metal mole number of 1 to 2. Alkaline earth metal salts are not preferred because they inhibit the stability of string micelles.
The phosphoric acid diester compound of tocopherol and ascorbic acid represented by the chemical formula (I) or (II) and the alkali metal salt thereof can be produced, for example, according to the production method described in JP-A-8-157488. . First, α-tocopherol, β-tocopherol, γ-tocopherol, or δ-tocopherol is reacted with phosphorus oxytrichloride in the presence of pyridine in a non-reactive solvent such as benzene, tocopherol phosphorodichloridate. Synthesize.
For example, for the monopotassium salt of the compound of formula (I), ascorbic acid is dissolved in dimethyl sulfoxide, potassium carbonate is added, and the tocopherol phosphorodichloridate dissolved in tetrahydrofuran is added thereto and reacted. After neutralization with dilute hydrochloric acid, the product is extracted, the extract is dissolved in dichloromethane, adjusted to pH 2.0-2.5 with potassium hydroxide / ethanol solution, and crystals of monopotassium salt of the compound of formula (I) Can be deposited.
For example, for the monopotassium salt of the compound of formula (II), ascorbic acid is dissolved in 1,3-dimethyl-2-imidazolidinone, lithium carbonate is added, and the tocopherol phosphorodichloridate dissolved in tetrahydrofuran is added thereto. And react. After neutralization with dilute hydrochloric acid, the product is extracted, the extract is dissolved in ethanol, and adjusted to pH 7-8 with a potassium hydroxide / ethanol solution. Since crystals precipitate, the crystals are collected by filtration, dissolved in ethyl acetate / dilute hydrochloric acid, and the organic layer is washed and concentrated. The concentrate is dissolved in isopropyl alcohol, adjusted to pH 4-5 with potassium hydroxide / isopropanol solution, the precipitate is filtered off, the filtrate is concentrated, dissolved in ethyl acetate / dilute hydrochloric acid, the organic layer is washed and concentrated. To do. The concentrate can be dissolved in isopropanol, adjusted to pH 8 with a potassium hydroxide / isopropanol solution, and the precipitated crystals can be collected by filtration to obtain a monopotassium salt of the compound of formula (II).

The potassium salt of dl-α-tocopherol 2-L-ascorbic acid diester (C ₃₅ H ₅₇ O ₁₀ P: molecular weight 668.80), which is an alkali metal salt of the chemical formula (II), is a commercially available product (EPC-K: Senju Pharmaceutical Co., Ltd.) can be used. EPC-K is an alkali metal salt containing 1-2 mol of potassium with respect to 1 mol of dl-α-tocopherol 2-L-ascorbic acid diester.
The phosphoric acid diester compound of tocopherol and ascorbic acid represented by the chemical formula (I) or (II) and its alkali metal salt are compounds that are expected to act as an antioxidant and a radical scavenger. Has a free radical scavenging action, phospholipase A2 inhibitory action, moisturizing action, normalization of the stratum corneum formation cycle, etc., and has been confirmed to have actions different from α-tocopherol and ascorbic acid alone or in combination. It is a substance. For EPC-K, acute toxicity test (oral / dermal), subacute toxicity test (13 weeks dermal), contact sensitization test, photocontact sensitization test, reverse mutation test, chromosome aberration test, The results of a series of toxicity tests such as primary skin irritation test, continuous skin irritation test, phototoxicity test, and general pharmacological tests suggest that the substance is highly safe.
The blending amount of the phosphoric diester compound of tocopherol and ascorbic acid represented by the chemical formula (I) or (II) and the alkali metal salt thereof is preferably 0.5% by mass or more, particularly 1% by mass or more in the composition. It is preferable for obtaining a sticky effect. If 3% by mass is added, a strong thickening effect can be obtained, but it can also be added at a higher concentration. If it is less than 0.5% by mass, it becomes difficult to sufficiently develop the viscoelastic effect of the string-like micelle.

`` Alkali metal salt ''
Examples of the alkali metal salt used in the present invention include sodium chloride, potassium chloride, sodium phosphate, potassium phosphate, sodium sulfate, potassium sulfate, sodium carbonate, potassium carbonate, sodium acetate, potassium acetate, sodium citrate, potassium citrate and the like. Is mentioned. Alkaline earth metal salts tend to form precipitates with phosphodiester compounds of tocopherol and ascorbic acid, and although undesirable, precipitation of alkaline earth metal salts with the addition of aqueous chelating agents is undesirable. Formation can be suppressed.
The blending amount of the alkali metal salt is preferably 4 to 100 moles per 1 mole of the phosphoric acid diester compound of tocopherol and ascorbic acid represented by the chemical formula (I) or (II) and the alkali metal salt thereof, It is particularly preferable to add 4 to 62 mol in order to obtain a thickening effect. When the blending amount of the alkali metal salt is less than 4 moles with respect to 1 mole of the phosphoric acid diester compound of tocopherol and ascorbic acid and the alkali metal salt thereof, it is difficult to form a cord-like micelle, Exceeding this may cause problems in usability.

"Nonionic surfactant with HLB of 3-12"
The nonionic surfactant used in the present invention has an HLB of 3 or more and 12 or less. By adding a nonionic surfactant, it becomes easy to form a string-like micelle and stability is improved. When the HLB of the nonionic surfactant is less than 3, dissolution in water becomes difficult, and when the HLB exceeds 12, string-like micelles are hardly formed. The HLB is particularly preferably 5 or more and 12 or less. When the HLB is 5 or more, the solubility of the nonionic surfactant is good.
Examples of the nonionic surfactant having an HLB of 3 or more and 12 or less include, for example, monoglycerol fatty acid esters, polyglycerol fatty acid esters having a glycerol polymerization degree of 2 or more, polyoxyethylene alkyl ethers, and polyoxyethylene alkyl esters. , Sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene hydrogenated castor oil, sucrose fatty acid esters, and the like. Of these, monoglycerol fatty acid esters, polyglycerol fatty acid esters having a polymerization degree of glycerol of 2 or more, and polyoxyethylene alkyl ethers are preferable.
The alkyl chain length, the degree of esterification, the degree of glycerol polymerization, and the degree of ethylene oxide polymerization may be selected so that the HLB of the nonionic surfactant is 3 or more and 12 or less.
The blending amount of the nonionic surfactant having an HLB of 3 or more and 12 or less is preferably 0.1 to 2% by mass in the composition. If the amount is less than 0.1% by mass, the stabilizing effect of the string micelles is hardly exhibited, and if it exceeds 2% by mass, a liquid crystal phase starts to be formed and turbidity may occur.

About string-like micelles
The composition of the present invention can be prepared by heating and dissolving a phosphoric acid diester compound of tocopherol and ascorbic acid represented by the chemical formula (I) or (II) and an alkali metal salt and an alkali metal salt thereof in water. Furthermore, the stability of the string micelle can be improved by dissolving a nonionic surfactant having an HLB of 3 or more and 12 or less. These components are preferably completely dissolved, and the dissolution temperature is preferably about 80 ° C.

  The composition of the present invention forms a molecular assembly called string-like micelle in water. Unlike a spherical micelle formed by a general surfactant, this molecular assembly has a string-like structure like a polymer when viewed macroscopically. For this reason, in water, they intertwine with each other and form a network structure, thereby exhibiting a specific viscoelastic behavior that combines not only viscosity but also elasticity like rubber. The difference between string-like micelles and polymers is that, while string-like micelles maintain a string-like structure by associating a plurality of molecules, a polymer forms one string with one molecule. The former causes slipping at the point of entanglement, whereas the latter does not cause slipping. Therefore, the viscoelastic behavior or the feeling of use when applied to the skin is different from conventional polymer-containing cosmetics. In particular, in the case of string-like micelles, the string-like micelle structure is temporarily destroyed at the time of application, so that it is possible to give a feeling of use that is much smoother than that of a polymer.

The viscoelastic behavior of string-like micelles can be described by a Maxwell model having a single relaxation time in a sufficiently developed string-like micelle, although it depends on the degree of entanglement. This is shown in a model in which one spring showing a hook elastic component and one dashpot showing a Newtonian viscous component are connected in series (FIG. 1).
The liquid defined by the single Maxwell model shown in FIG. 1 has not been reported other than the string-like micelle solution, and can be said to have a unique behavior unique to the string-like micelle.

<Elastic modulus in Maxwell model>
A well-developed string micelle solution defined by a single Maxwell model exhibits behavior corresponding to the following equation when dynamic viscoelasticity measurement is performed using a stress-controlled rheometer.
[Formula 1]

At this time, G ′ (ω) (Pa) is the storage elastic modulus, G ″ (ω) (Pa) is the loss elastic modulus, ω (rad · s ⁻¹ ) is the angular velocity (angular frequency) of the shearing stress, and τ ( s) represents the relaxation time, where the relaxation time τ (s) represents the time required for the initial value of the applied shear stress to be 1 / e (e is the base of natural log = 2.718). (ω) corresponds to a change in elastic modulus of a portion where energy is stored when a shear stress is applied to the sample, that is, a spring portion in the model diagram of FIG. 1, and G ″ (ω) is a portion of energy loss. That is, this corresponds to a change in the viscosity of the dashpot portion in the model diagram of FIG.
This behavior is schematically shown in FIG. 2 when the horizontal axis ω and the vertical axis G ′ (ω) and G ″ (ω) are schematically illustrated.
G _{0 in} Equation 1 represents the flat elastic modulus in the plateau region of G ′ obtained on the high frequency side in FIG.
As can be derived from Equation 1, the G ′ curve and the G ″ curve intersect at G ′ = G ″ at ω = 1 / τ. In addition, when the dynamic viscoelastic behavior represented by Equation 1 is shown, taking the Cole-Cole plot (G ″ vsG ′) has the property that the data is completely overlapped in a semicircular shape centered on the G ′ axis. That is, by taking a Cole-Cole plot (G ″ vsG ′), the formation of string micelles can be easily determined.

<Viscosity in Maxwell model>
The dynamic viscosity η ′ (ω) of the solution showing the Maxwell model is defined by the following equation.
[Formula 2]

On the very low frequency side, η ′ (ω) has the following expression.
[Formula 3]

  Η obtained here corresponds to a viscosity coefficient in a static state, that is, zero shear viscosity.

<Confirmation of string micelle by electron microscope>
Furthermore, it can be confirmed from an electron micrograph that string-like micelles are formed in the composition of the present invention. In dynamic viscoelasticity measurement using a stress-controlled rheometer, when the intersection of the G ′ curve and the G ″ curve appears outside the measurable range due to the limitation of the measurement range, the Cole-Cole plot (G ″) Even when it is difficult to determine whether vsG ′) is a semicircle, string-like micelles can be confirmed by an electron micrograph.

"Use"
The composition of the present invention can be used as a skin external preparation (cosmetics, quasi-drug, pharmaceutical). It can be used as a base or carrier for these external preparations for skin. When the composition of the present invention is applied to the skin, the viscosity decreases due to shear stress, and it can be easily spread. After spreading, the viscosity recovers and does not sag. This property is also suitable for pack agents. Since the viscosity drops when applied, it is easy to spread thickly on the skin, after which the viscosity is restored and dripping does not occur.
As cosmetics and quasi-drugs, it can be used in lotions, cosmetic liquids, pack cosmetics, etc., and as pharmaceuticals, it can be used in lotions and the like.
Alternatively, it can be used as a base for general adhesive coating agents.
Or since it shows a gel form in a static state, it is a gel-like food and drink, and can provide a food and drink in a unique form that exhibits a dosage form transformation that exhibits fluidity by biting in the mouth. In addition, the composition of the present invention can be provided as a two-part type of an aqueous solution of a phosphoric diester compound of tocopherol and ascorbic acid and an aqueous solution of an alkali metal salt. An aqueous solution of a phosphoric acid diester compound of tocopherol and ascorbic acid and an aqueous solution of an alkali metal salt each have low viscosity, and can be easily filled into a container or impregnated into a cloth. And develops thickening. It is also possible to mix an aqueous solution of a phosphoric acid diester compound of tocopherol and ascorbic acid and an alkali metal salt in a powder state, dissolve in the aqueous solution at the time of use, and increase the viscosity.

<Preparation of string micelle>
Components 1 to 76 and Comparative Examples 1 to 9 having the compositions shown in Tables 1 to 10 were mixed, heated and dissolved at 80 ° C., and then cooled to room temperature to prepare string micelles.

The viscosities of the liquid compositions of Examples 1 to 76 and Comparative Examples 1 to 3 were visually evaluated according to the following criteria.
The evaluation results are shown in Tables 1-9.
It was confirmed that the liquid compositions of Examples 1 to 76 had viscosity and formed string-like micelles.

Visual evaluation criteria ◎: Sufficient thickening due to string micelles can be observed, and bubbles can be kept in the liquid for 10 seconds or longer.
When the sample bottle is further tilted to 45 °, the gas-liquid interface does not become horizontal even after 10 seconds.
○: Thickening due to string-like micelles can be observed, and bubbles can be held in the liquid for 10 seconds or more, but when the sample bottle is tilted, the gas-liquid interface becomes horizontal within 10 seconds.
Δ: Slight thickening due to string micelles can be observed, and bubbles can be held in the liquid for 1 second or longer.
Can not hold for more than 10 seconds.
X: Thickening is not seen. Air bubbles cannot be kept in the liquid for more than 1 second.

Among Examples 1 to 76 and Comparative Examples 1 to 9, representative samples (Examples 12, 19, 22, 27, 31, 37, 46, 51, 56, 60, 62, 65, 74, 76, comparison) Viscosity measurements were made on Examples 2, 5).
Since the string-like micelle solution has a network structure throughout the solution, it behaves as a non-Newtonian fluid. When such a non-Newtonian fluid is measured with a rotational speed control type viscometer (B-type viscometer), the network structure in the liquid collapses and the viscosity increases as the rotational speed of the rotor increases. There is a problem that decreases.
Further, since it is difficult to measure at a low rotational speed, the rotational speed control type viscometer is difficult to measure without destroying the internal structure of the sample. In particular, in a sample having a relatively low viscosity, the viscosity may drop to the same level as water, and it is almost impossible to detect the viscosity of the string micelle.
Therefore, in order to evaluate the network structure of the string-like micelle solution as non-destructively as possible, a stress-controlled rheometer capable of giving a minute deformation to the sample was used. Using a stress-controlled rheometer, the viscosity at which the shear rate can be approximated to zero, that is, zero shear viscosity was measured.
There are two types of measurement methods for zero shear viscosity, and there are a method for determining from dynamic viscoelasticity measurement shown in Example 12 and a method for determining from a viscosity curve obtained by steady flow measurement (static measurement). However, in the former case, in the case of a sample having an extremely long relaxation time, the measurement takes time, and further, there is a problem that the measurement accuracy is lowered due to volatilization of water in the sample during the measurement. Therefore, this time, we decided to measure the zero shear viscosity by the latter method. In the region where the shear rate is as close to zero as possible, even if it is a non-Newtonian fluid, there is a region that can be approximated to a Newtonian fluid, and the viscosity in that region does not vary and shows a certain value. The viscosity η at this time can be handled as _zero shear viscosity η ₀ .
As a measuring apparatus, a stress control type rheometer AR-G2 (manufactured by TA Instruments) was used, and a cone and plate system having a diameter of 4 cm (cone angle of 1 °) was used. All measurements were performed in the steady flow measurement mode under 25 ° C conditions, the viscosity was measured by changing the shear rate from 0.001 to 10 (s-1) in logarithmic increments, and a viscosity curve was obtained (each time it was incremented by one digit). 10 plot measurements.). Each plot used the value when the fluctuation of the torque value of the device was within 5% and the data was stable. Although it depends on the hardness of the sample, the viscosity shows a constant value when the shear rate is about 0.1 (s-1) or less (zero shear viscosity). The constant value was taken as the measured value.
The obtained viscosity was determined based on the following evaluation criteria.

Evaluation criteria by zero shear viscosity measurement method ◎: 1.0 × 10 ⁶ mPa · s ≦ η ₀
○: 1.0 × 10 ³ mPa · s ≦ η ₀ < 1.0 × 10 ⁶ mPa ・ s
Δ: 1.0 × 10 ² mPa · s ≦ η ₀ < 1.0 × 10 ³ mPa ・ s
×: η ₀ < 1.0 × 10 ² mPa ・ s

The obtained viscosity and evaluation are shown in Tables 2, 3, 4, 5, 6, 7, 8, 9, and 10.

About Example 12, a dynamic viscoelasticity measurement result is shown.
The dynamic viscoelasticity measurement was performed at 25 ° C. using a stress control type rheometer CSL100 (manufactured by Carri-Med Ltd) and a cone and plate system having a diameter of 4 cm (cone angle 2 °).
A G ′ curve and a G ″ curve graph of the corded micelle solution of Example 12 are shown in FIG. 3. The G ″ curve has a clear maximum value at the intersection with the G ′ curve, and G ″ is the maximum value. Since it has a flat region where the G ′ curve has a constant value in a region where the angular velocity is equal to or higher than the angular velocity, it can be seen that the behavior of a typical Maxwell fluid is shown.
FIG. 4 shows the η ′ curve of the string micelle solution of Example 12. The _zero shear viscosity η ₀ determined from this curve was 42 Pa · s.
A Cole-Cole plot (G ″ vsG ′) of the corded micelle solution of Example 12 is shown in FIG. 5. The data is distributed in a semicircular shape centering on G ″ = 0 and G ′ = 0.95. From this, it can be seen that the behavior of a typical Maxwell fluid is shown. This behavior is not reported except for the string-like micelle, and is a behavior different from that of the polymer.

The dynamic viscoelasticity measurement result is shown for Example 37.
A graph of the G ′ curve and the G ″ curve of the string-like micelle solution of Example 37 is shown in FIG. 6. Since Example 37 is a system that does not contain any surfactant, the string-like micelle is different from Example 12. It shows different behavior.
Similar to the twelfth embodiment, the G ′ curve and the G ″ curve intersect, but G ″ does not have a clear maximum value, and not only G ′ but also G ″ exhibits a flat angular velocity dependency. This does not show the behavior as a Maxwell fluid, but is generally observed during the growth process of string micelles (Shikata, T .; Hirata, H .; Kotaka, T. Lanagmuir 1988, 4, 354). .)).
In this way, the string-like micelle of this system may not show the behavior as Maxwell fluid when there is no surfactant, and it is difficult to clearly determine whether it is a string-like micelle. There is. In such a case, it is effective to observe the string-like micelle structure with a transmission electron microscope.
A Cole-Cole plot (G "vsG ') of the string micelle solution of Example 37 is shown in Fig. 8. The data distribution is not semicircular, and shows the behavior of a typical Maxwell fluid. I can't say that.

<Transmission electron microscope observation>
The electron micrographs of Examples 12 and 37 are shown in FIGS.
The photographing conditions for the electron micrograph are as follows.
Sample preparation <Equipment>
Rapid freezing equipment EM-CPC (manufactured by LEICA)
<Quick freeze condition>
Freezing refrigerant: Liquid ethane Freezing temperature: <-170 ° C
procedure:
1) Since the sample cannot be thinly stretched on the grid when the viscosity of the sample is high, Example 12 was diluted with purified water 3 times and Example 37 was diluted 10 times with purified water.
2) A sample diluted with purified water (approx. 4 microliters) is dropped on the grid. 3) Absorb the excess with filter paper to make a thin film (<300nm)
4) Instant freezing into liquid ethane for rapid freezing (formation of amorphous ice)

Direct observation by transmission electron microscope <Device>
Transmission electron microscope H-7650 (manufactured by Hitachi High-Technologies)
<Observation conditions>
Accelerating voltage: 120 kV
Emission current: 3 microamperes Spot size: 1 micrometer Observation temperature: <-170 ° C
Low dose condition mode
Cryotransfer CT-3500 (manufactured by Oxford Instruments)

  As shown in FIGS. 9 and 10 for both Examples 12 and 37, the structure of the string-like micelles was clearly observed by electron microscope observation. The string-like micelle can be confirmed by observing a string-like structure having a thickness of about 3 nm and a length of 200 nm or more.

Formulation Example 1 Moisturizing pack Ingredients Amount (% by mass)
1. Ascorbyl / potassium tocopheryl phosphate 2
2. Sodium chloride 1
3. Capric acid monoglyceride 0.2
4). Glycerin 2
5.1,2-Pentanediol 1.5
6). Purified water residue

Formulation Example 2 Moisturizing Lotion Ingredients Amount (% by mass)
1. Ascorbyl / potassium tocopheryl phosphate 1
2. Sodium chloride 0.5
3. Stearic acid monoglyceride 0.2
4). Glycerin 0.5
5.1,3-Butylene glycol 5
6.1,2-Pentanediol 1
7). Ethylhexyl glycerin 0.1
8). Sodium hyaluronate 0.001
9. Purified water residue

Claims (8)

(A) One or two or more selected from the following compounds (a1) to (a4), (b) an alkali metal salt, and (c) water, and forming string-like micelles Characteristic composition.
(A1): phosphoric acid diester compound of tocopherol and ascorbic acid represented by the following chemical formula (I)
[R ₁ and R ₂ in the formula each represent a hydrogen atom or a methyl group. ]
(A2): alkali metal salt of (a1) (a3): phosphoric acid diester compound of tocopherol and ascorbic acid represented by the following chemical formula (II)
[R ₁ and R ₂ in the formula each represent a hydrogen atom or a methyl group. ]
(A4): Alkali metal salt of (a3)   The composition according to claim 1, wherein the blending amount of (a) is 0.5% by mass or more.   The composition according to claim 1 or 2, wherein the blending molar ratio of (a) :( b) is 1: 4 to 1:60.   Furthermore, (d) HLB contains 3 or more and 12 or less nonionic surfactant, The composition in any one of Claims 1-3 characterized by the above-mentioned.   5. (d) is one or more selected from the group consisting of monoglycerol fatty acid esters, polyglycerol fatty acid esters having a polymerization degree of glycerol of 2 or more, and polyoxyethylene alkyl ethers. The composition as described.   A thickener comprising the composition according to any one of claims 1 to 5.   The skin external preparation containing the composition in any one of Claims 1-5.   Food-drinks containing the composition in any one of Claims 1-5.