JP7519692B2 - Natural cosmetics - Google Patents

Description

The present invention relates to cosmetics that are safe and environmentally friendly by using only naturally derived raw materials, and have the same effects as petroleum-derived cosmetics.

Cleansing cosmetics are examples of cosmetics that remove dirt and makeup from the skin. Moisturizing cosmetics such as lotions, serums, and gels are examples of cosmetics related to moisturizing. Conventionally, it has been important for cleansing cosmetics to easily wash away dirt and makeup from the skin. Cleansing cosmetics are classified into various types such as oil, liquid, balm, gel, cream, and milk. Oil-type cleansing cosmetics are mainly composed of oily ingredients, and are used to lift skin dirt such as makeup and sebum from the skin with the oily ingredients, and then washed away with water. Although they are highly effective at removing makeup, they tend to leave an oily feeling even after rinsing with water, and the refreshing feeling after washing tends to be insufficient. In addition, when used with the skin or hands wet with a small amount of water, the oil is instantly emulsified into an oil-in-water (O/W) type, which reduces the compatibility with makeup and sebum, etc., and reduces the cleansing power. Liquid types are mainly composed of surfactants, and can be used without problems when the skin or hands are wet with a small amount of water. However, since makeup stains are emulsified and dispersed from the skin by the surfactant and then washed away with water, they have a refreshing feeling after washing, but tend to have insufficient makeup removal effects. In addition, most cream types are O/W emulsions, and the moisture is evaporated by massaging during use, causing the structure to change to a water-in-oil (W/O) emulsion structure, which allows the makeup stains and sebum on the skin to blend in, making it difficult to cleanse in a short time. After the phase change, water is added to cause the structure to change back to an O/W emulsion structure, which is then washed away with water. However, the cleansing power is inferior to that of oil types, and the refreshing feeling after washing is not sufficient like that of liquid types. The above cleansing cosmetics need to be used according to the level of makeup stains and skin stains, and if the purpose of each cleansing cosmetic is not suitable, there is a problem that it can lead to an uncomfortable feeling after washing.

In recent years, there has been a demand for cleansing cosmetics that maintain high cleansing power and provide a refreshing feeling after washing with little stickiness even when used with the skin or hands wet with a small amount of water, and cleansing cosmetics with a bicontinuous microemulsion structure have become common. A bicontinuous microemulsion structure is one in which both the aqueous phase and the oil phase form continuous and random layers in an irregularly intricate structure, making them bicontinuous. When used as a cleansing cosmetic, this structure has good compatibility with makeup stains and sebum stains. When water is then added during rinsing, an aqueous solution with an O/W type microemulsion structure is formed. In this aqueous solution with an O/W microemulsion structure, the oily components that have incorporated makeup stains and sebum stains are incorporated in the particles of the O/W microemulsion structure in a thermodynamically stable state, so that they do not reattach to the skin and can be easily washed off, resulting in a refreshing feeling after washing without a sticky feeling.

On the other hand, moisturizing cosmetics are intended to keep the skin moisturized, and lotions, beauty serums, gels, etc., which consist mainly of water-soluble moisturizing ingredients and water, are characterized by replenishing moisture in the skin, preventing moisture loss, and maintaining moisture. However, one-liquid-phase moisturizing cosmetics consisting of water-soluble ingredients require solubilization with a surfactant in order to incorporate oily ingredients, but there is a problem in that the amount of oily ingredients that can be solubilized is very small.

In recent years, by using an O/W microemulsion former, it has become possible to increase the amount of oily ingredients in the above moisturizing cosmetics without separating them. As a result, it has become possible to further improve the moisturizing properties of moisturizing cosmetics that previously consisted mainly of water-soluble moisturizing ingredients and water by adding an oily ingredient.

Furthermore, cosmetics that use ingredients produced from petroleum, a limited resource that is feared to be depleted in the future, are unsuitable for a recycling-oriented society and cannot be considered environmentally friendly. On the other hand, naturally derived ingredients are considered to be suitable for a sustainable recycling-oriented society and are thought to lead to the sustainable conservation of the global environment. Furthermore, due to the recent increase in consumers' awareness of safety and security, cosmetics that are free of petroleum-derived ingredients (mineral oils and polyoxyethylene-based surfactants) are preferred, and the number of consumers seeking cosmetics made from naturally derived ingredients is on the rise.

JP 2009-196909 A JP 2008-106012 A JP 2010-280644 A

When producing cosmetics having a bicontinuous microemulsion structure, the surfactant required for forming both the oil phase consisting of oily components and the aqueous phase consisting of aqueous components into a continuous phase is often a polyoxyethylene surfactant, which is a petroleum-derived surfactant such as polyoxyethylene glycerin fatty acid ester, due to the extensive research experience and cost advantages. Petroleum-derived polyglycerin fatty acid esters may also be used.

As with bicontinuous microemulsion structures, cosmetics having an O/W microemulsion structure often use polyoxyethylene surfactants such as petroleum-derived polyoxyethylene glycerin fatty acid esters as surfactants required to disperse the oily components in the water as fine droplets in an oil phase consisting of oily components and an aqueous phase consisting of aqueous components. Petroleum-derived polyglycerin fatty acid esters may also be used.

Polyglycerol fatty acid esters used in preparing bicontinuous microemulsion formers and O/W microemulsion formers have been studied to obtain bicontinuous microemulsion formers and O/W microemulsion formers with stable properties using petroleum-derived polyglycerols with a content of cyclic isomers of 25% by weight or less. On the other hand, polyglycerol fatty acid esters produced using naturally derived polyglycerols with a content of cyclic isomers of more than 25% by weight have problems in terms of functionality, such as a lower effective polymerization degree and lower hydrophilicity, resulting in inferior solubilizing power, and higher costs compared to polyoxyethylene-based surfactants, compared to petroleum-derived polyglycerol fatty acid esters. Therefore, in the cosmetic field, research into obtaining bicontinuous microemulsion formers and O/W microemulsion formers from naturally derived polyglycerol fatty acid esters has not progressed sufficiently.

In addition, naturally derived polyglycerol fatty acid esters are mixtures of more components and more complex composition than polyglycerol fatty acid esters produced using petroleum-derived polyglycerols with a cyclic isomer content of 25% by weight or less. Therefore, when preparing a bicontinuous microemulsion-forming product using naturally derived polyglycerol fatty acid esters, it is necessary to find a limited composition range in which a naturally derived polyglycerol fatty acid ester can be prepared as a transparent one-phase liquid in which the aqueous phase and the oil phase are bicontinuous in a three-dimensionally complicated structure while containing many components, and it is also necessary to maintain a stable state (hereinafter referred to as time-dependent and temperature-dependent stability) with little change in properties over time and change in properties due to temperature change. Furthermore, naturally derived polyglycerol fatty acid esters have lower functional aspects such as solubilizing power compared to petroleum-derived polyglycerol fatty acid esters. Therefore, simply replacing petroleum-derived polyglycerol fatty acid esters with naturally derived polyglycerol fatty acid esters does not result in a cosmetic product having a bicontinuous microemulsion structure obtained using petroleum-derived polyglycerol fatty acid esters. The prior art is shown below.

In Patent Document 1, a bicontinuous microemulsion product is obtained by blending a nonionic surfactant, an oily component, water, a polyhydric alcohol other than 1,2-alkanediol having 5 to 10 carbon atoms, and a 1,2-alkanediol having 5 to 10 carbon atoms. There is no mention of the temporal or temperature stability of the bicontinuous microemulsion product obtained in Patent Document 1, and it is known that the aqueous phase and the oil phase may separate from the bicontinuous microemulsion structure. Patent Document 1 does not mention measures to deal with the effects of temperature changes on the bicontinuous microemulsion product, so the bicontinuous microemulsion structure cannot be maintained when the temperature changes, and there is a risk of the function and quality of the cleansing cosmetic being reduced. In addition, there is no mention of whether the raw materials used are of natural origin, i.e., there is no mention of environmental considerations.

Patent Document 2 discloses a cosmetic having a bicontinuous microemulsion structure, which is characterized by excellent percutaneous absorption effect of coenzyme Q10 when applied to the skin by blending coenzyme Q10, a surfactant containing polyglycerol fatty acid ester having a cyclic content of 25% or less by weight and an HLB value of 10 to 18, liquid oil having a solubility parameter (SP value) of 8.0 to 10.5 at 25°C, and a polyhydric alcohol. In Patent Document 2, the cyclic content in polyglycerol, which is a characteristic of petroleum-derived polyglycerol, is limited to 25% by weight or less, so it can be seen that polyglycerol fatty acid ester is produced using petroleum-derived polyglycerol. It is easy to obtain a bicontinuous microemulsion-forming product with stable properties from petroleum-derived polyglycerol fatty acid ester, but the raw materials for petroleum-derived polyglycerol fatty acid ester use carcinogenic glycidol, epichlorohydrin, etc., and therefore there is concern about safety to the skin. At the same time, since it is derived from petroleum, there is concern that it will be depleted in the future, making it an unsuitable raw material for a recycling society, and it is difficult to say that it is environmentally friendly. In addition, it is a raw material that is difficult to meet the demands of consumers and society for safety and security. In addition, the inventors of the prior art have conducted experiments to illustrate the case where a polyglycerol fatty acid ester having a cyclic content of 35% by weight, 38% by weight, 40% by weight, and 47% by weight is blended with a trihydric alcohol alone , and it has been revealed that a bicontinuous microemulsion structure with stable properties cannot be formed. In other words, it is clear that it is not easy to form a bicontinuous microemulsion structure with stable properties using a naturally derived polyglycerol fatty acid ester having a cyclic content of more than 25% by weight in the polyglycerol.

Including the above Patent Documents 1 and 2, many reports have been published in the field on the results of using polyglycerol fatty acid esters to produce cosmetics having a bicontinuous microemulsion structure. However, there have been no reports on cosmetics that use only naturally derived raw materials that are highly safe and can meet the safety and security-oriented demands of consumers and society, and that maintain a bicontinuous microemulsion structure or an O/W microemulsion structure that is stable over time and temperature.

The present invention was made in consideration of the above problems, and aims to provide cosmetics that use only naturally derived raw materials, which are safer for the skin than cosmetics made with petroleum-derived raw materials, are environmentally friendly, and have the same effects as petroleum-derived cosmetics.

In order to solve the above problems, the naturally derived cosmetic of the present invention is made from polyglycerol as a raw material, which has a cyclic content of more than 25% by weight and an average degree of polymerization of 3 to 10, and has at least one saturated or unsaturated fatty acid residue having 10 to 18 carbon atoms, The emulsion is characterized in that the emulsion contains as blended ingredients a polyglycerol fatty acid ester having a weighted average HLB value exceeding 10 when one or more of the polyglycerol fatty acid esters are used in combination, a dihydric alcohol having 3 to 7 carbon atoms, glycerin, or a polyglycerol having an average degree of polymerization of 2 to 10, or a sugar alcohol, or a polyhydric alcohol mixture obtained by mixing a dihydric alcohol having 3 to 7 carbon atoms and at least one of glycerin , a polyglycerol having an average degree of polymerization of 2 to 10, or a sugar alcohol, an oily component, and water, the polyglycerol fatty acid ester is contained in an amount of 24.2% to 31.0%, and the sugar alcohol is selected from erythritol, xylitol, sorbitol, trehalose, sucrose, maltitol, or mannitol, forming a bicontinuous microemulsion structure, and the blended ingredients are naturally derived raw materials. The term "polyhydric alcohol monohydrate" refers to an alcohol that is composed of a single polyhydric alcohol, and the term "polyhydric alcohol mixture" refers to an alcohol that is composed of a mixture of multiple types of polyhydric alcohol.

The naturally derived cosmetic composition of the present invention is further characterized in that it contains at least one saturated or unsaturated fatty acid having 8 to 22 carbon atoms as a temperature-stable component.

The naturally derived moisturizing cosmetic of the present invention is characterized in that it comprises a naturally derived cosmetic as described in claim 1 or claim 2 and a naturally derived water-soluble component containing water, and has an O/W microemulsion structure.

The raw materials used for petroleum-derived polyglycerol fatty acid esters include carcinogenic glycidol and epichlorohydrin, raising safety concerns. On the other hand, the naturally derived cosmetic product of the present invention is produced using only naturally derived raw materials for all of its ingredients, including the polyglycerol fatty acid ester, and therefore can provide cosmetics that meet the safety and security needs of consumers and society, as well as environmental considerations.

Conventionally, cosmetics produced using naturally derived raw materials have not been able to produce bicontinuous microemulsion-forming products or O/W microemulsion-forming products that are excellent in stability over time and temperature, and it has not been easy to produce cleansing cosmetics or moisturizing cosmetics such as lotions, serums, and gels that use naturally derived raw materials. According to the naturally derived cosmetic of the present invention, a bicontinuous microemulsion-forming product or O/W microemulsion-forming product that is excellent in stability over time and temperature can be obtained reproducibly using only naturally derived raw materials, and the same cleansing effect or moisturizing effect can be obtained compared to cosmetics produced using petroleum-derived polyglycerol fatty acid esters, making it possible to provide consumers with naturally derived cosmetics that meet the demands of environmental consideration.

In the past, when attempting to form a bicontinuous microemulsion forming product or an O/W microemulsion forming product by blending a dihydric or trihydric alcohol alone with a naturally derived polyglycerol fatty acid ester, it was believed that it was not possible to obtain a target product with excellent stability over time and temperature. However, according to the naturally derived cosmetic composition of the present invention, by blending a polyhydric alcohol alone or a polyhydric alcohol mixture containing at least a dihydric alcohol and a trihydric or higher polyhydric alcohol, it is possible to obtain a bicontinuous microemulsion forming product or an O/W microemulsion forming product with excellent stability over time and temperature.

By incorporating a temperature-stable component, the bicontinuous microemulsion structure can be stably maintained even when the temperature of the naturally derived cosmetic of the present invention changes due to changes in the environmental temperature. A "temperature-stable component" is a component that can maintain the properties of the composition without changing them when temperature changes occur. This makes it possible to obtain a cosmetic that has excellent stability over time and temperature and whose quality does not change even when stored in a place where the temperature changes drastically, such as a bathroom.

1 is a photograph comparing the appearance of a naturally derived cosmetic product obtained according to the present invention (on the right side of the figure) with a petroleum derived cosmetic product obtained according to Patent Document 3 (on the left side of the figure). 1 is a graph showing the change over time in the moisture content of the stratum corneum for a product containing squalane and a product not containing squalane, with the value before application set to "1." 1 is a graph showing the change over time in the amount of transepidermal water loss for a product containing squalane and a product not containing squalane, with the amount before application being set to "1." 1 is a photograph showing the appearance of a cleansing cosmetic preparation obtained according to the formulation of Example 4 of Patent Document 1 in Comparative Example 1.

Naturally derived ingredients are cosmetic ingredients that are natural products or substances derived from nature, with plant extracts being the main ingredients. In addition to extracts, other examples include royal jelly, a secretion from honeybees, and fermented soy milk filtrate obtained by fermenting soy milk. The ingredients of these natural products include amino acids, proteins, organic acids, sugars, vitamins, etc., and when incorporated into cosmetics, they are expected to have moisturizing effects and prevent rough skin.

The inventors of the present application have focused on natural ingredients and have undertaken the development of cleansing cosmetics and moisturizing cosmetics whose ingredients are all naturally derived, as petroleum-derived cosmetics raise concerns about their safety for the skin, are not considered to be environmentally friendly, and are difficult to meet the safety and security-oriented demands of consumers and society.

In Patent Document 2, the inventors of the prior art experimented with a polyglycerol fatty acid ester having a cyclic content of 35% by weight, 38% by weight, 40% by weight, and 47% by weight, and a trihydric alcohol was added alone to the polyglycerol fatty acid ester, and it was found that a bicontinuous microemulsion structure with stable properties could not be formed. In other words, it is shown that there is a problem in forming a bicontinuous microemulsion structure with stable properties using a naturally derived polyglycerol fatty acid ester having a cyclic content of more than 25% by weight in the polyglycerol. The formulation and emulsion stability of the bicontinuous microemulsion formed using a polyglycerol fatty acid ester having a cyclic content of 35% by weight, 38% by weight, 40% by weight, and a trihydric alcohol, which are listed in Table 4 of the prior art, are shown in Table 1. In Patent Document 2, the term "emulsion stability" is used, but this term indicates the change in properties over time and the change in properties due to temperature changes, and is synonymous with "temporal and temperature stability" in this specification. Since Patent Document 2 gives an evaluation of "x" for emulsion stability, it is understood that the problem that the inventors of the present application must overcome is not easily solvable by those skilled in the art. The "%" of the blending ratio in the table is "% by weight".

Since naturally derived polyglycerol fatty acid esters are mixtures of complex composition, when using them to prepare bicontinuous microemulsion forming products, it is necessary to find a limited composition range where many of the components contained in the naturally derived polyglycerol fatty acid esters can be prepared into a transparent one-phase liquid in which the aqueous phase and the oil phase are bicontinuous with a three-dimensionally intricate structure, and where the blend has stability over time and temperature.

Therefore, the inventors focused on the balance between the lipophilicity and hydrophilicity of naturally derived polyglycerol fatty acid esters and on mixed systems of multiple polyhydric alcohols, and decided to explore the formulation and ratios that would allow the formation of a bicontinuous microemulsion that is stable over time and across temperature using naturally derived polyglycerol fatty acid esters.

[Prerequisites for conducting the test]
The polyglycerol fatty acid ester is obtained by esterifying a naturally derived polyglycerol having a cyclic isomer content of more than 25% by weight in polyglycerol with a fatty acid, and serves as a surfactant for forming a bicontinuous microemulsion structure. As a composition other than the polyglycerol fatty acid ester, a polyhydric alcohol alone or a polyhydric alcohol mixture containing at least a dihydric alcohol and a trihydric or higher polyhydric alcohol is blended on the assumption that it serves to moisturize the skin, and an oily component is blended on the assumption that it serves as a cleansing component for removing dirt including makeup in the bicontinuous microemulsion former.

[Method for selecting blended samples]
As the polyglycerol fatty acid esters, several representative types of naturally derived polyglycerol fatty acid esters exemplified in the following paragraph were selected as samples.
As the dihydric alcohol, several representative types of naturally occurring dihydric alcohols exemplified in the following paragraph were selected.
As the trihydric or higher polyhydric alcohol, several representative types were selected from among the naturally occurring trihydric or higher polyhydric alcohols exemplified in the following paragraph.
As the oily components, several representative types were selected from among the naturally derived oily components exemplified in the following paragraph.

A method for preparing a cosmetic composition using the above-mentioned naturally occurring polyglycerol fatty acid ester, polyhydric alcohol and oily component is described below.
[Preparation method 1]
1. Phase A consisting of a polyglycerol fatty acid ester and an oily component, and phase B consisting of a polyhydric alcohol and water are each heated and dissolved at 70°C.
2. Next, phase B is added to phase A, and after stirring to dissolve, the mixture is cooled to 35°C with stirring to obtain the desired bicontinuous microemulsion.
Other preparation methods include the following preparation method.
[Preparation method 2]
1. Heat and dissolve the polyglycerol fatty acid ester, polyhydric alcohol, and oil components (excluding water) at 70°C.
2. Next, water heated to 70° C. is added, and after stirring to dissolve, the mixture is cooled to 35° C. to obtain a bicontinuous microemulsion.
The above two methods are merely examples of the preparation method, and the present invention is not limited to these.

[Confirmation method]
The mixture of polyglycerol fatty acid ester, polyhydric alcohol and oily component was changed, and the specimen obtained by the above-mentioned preparation method was sealed in a glass bottle and visually observed for two items: appearance and solubility in aqueous and oily dyes. The specimen that had a transparent one-phase appearance and could dissolve both aqueous and oily dyes was judged to be a bicontinuous microemulsion forming product. The obtained bicontinuous microemulsion forming products were placed in incubators at 5°C, 25°C and 50°C, and the state change was visually observed every predetermined period, and the one that maintained the appearance of a transparent one-phase liquid was marked as "○" for time-dependent temperature stability. The predetermined period was every day until the 10th day, every 5 days from the 11th day to one month, and every month after one month.
Based on the above assumptions, the method for selecting the blended sample, the method for preparing the cosmetic composition, and the method for confirming the bicontinuous microemulsion forming product, the following tests were carried out.

Below, we will examine the effects of each of the polyglycerol fatty acid esters, polyhydric alcohols, and oily components when preparing a naturally derived bicontinuous microemulsion former, and show the optimal blends and ratios that will allow us to obtain a cosmetic product with a naturally derived bicontinuous microemulsion structure that is stable over time and temperature.

(Test to prepare bicontinuous microemulsion forming substances using polyhydric alcohol alone and polyhydric alcohol mixture)
As mentioned above, it is known that when a bicontinuous microemulsion forming material is prepared by blending a polyhydric alcohol alone with a naturally derived polyglycerol fatty acid ester, a target product having time and temperature stability cannot be obtained. This is because naturally derived polyglycerol fatty acid esters are mixtures with complex compositions, so even if a bicontinuous microemulsion forming material is obtained, it is difficult to provide time and temperature stability. Therefore, the preparation of a cosmetic having a bicontinuous microemulsion structure using a naturally derived polyglycerol fatty acid ester and a dihydric or higher polyhydric alcohol has not been pursued.

In this specification, tests (Tests 1 to 7) were conducted again on combinations for preparing bicontinuous microemulsion formers using commercially available naturally occurring dihydric alcohols alone , trihydric alcohols alone , other polyhydric alcohols alone , sugar alcohols alone , mixed systems of dihydric and trihydric alcohols, and mixed systems of dihydric and tetrahydric or higher polyhydric alcohols, to search for blends and ratios that can prepare bicontinuous microemulsion formers having stability over time and temperature. Sugar alcohol is the name given to polyhydric alcohols obtained by reducing the aldehyde groups of sugars.

[Test 1]
A test was carried out to prepare a bicontinuous microemulsion by blending a naturally derived polyglycerol fatty acid ester with a dihydric alcohol alone .
(Formulated sample)
The polyglycerol fatty acid esters were polyglyceryl-10 isostearate (HLB value: 13.7) and polyglyceryl-10 laurate (HLB value: 14.7), and a combination capable of preparing a bicontinuous microemulsion former having stability over time and temperature was examined. HLB indicates the hydrophilic-lipophilic ratio of a surfactant, and is an index for obtaining a stable emulsion when a surfactant is used as an emulsifier. The HLB is expressed as a value between "0" when the surfactant does not have a hydrophilic group and "20" when the surfactant does not have a lipophilic group. When used as a cleansing cosmetic, a bicontinuous microemulsion former having a small HLB value has an oily residual feeling on the skin when washed off, and has poor water washability. On the other hand, it is known that when the HLB value becomes large beyond the appropriate range, a bicontinuous former having stable properties, such as a product with a cloudy appearance, cannot be obtained, and the above was used as a reference for the selection.
The test was conducted by selecting propanediol as the dihydric alcohol and squalane as the oily component and cleansing component.

(Test method)
Using preparation method 1 or preparation method 2, preparations were made by changing the blend and ratio of polyglycerol fatty acid ester, dihydric alcohol, and oily component, and the obtained samples were visually observed based on the above-mentioned confirmation method.

(Test results)
The data of the formulation for preparing a bicontinuous microemulsion forming material in a single dihydric alcohol system is shown in Table 2. The "%" of the blend ratio in the table is "% by weight". The same applies to the following tables.
In the case of a formulation containing only a dihydric alcohol, a bicontinuous microemulsion was obtained by adjusting the amount and composition of the surfactant, and the properties were maintained even after a period of 7 days, showing good stability over time and temperature.

[Test 2]
A test was carried out to prepare a bicontinuous microemulsion by blending naturally derived polyglycerol fatty acid ester with a trihydric alcohol alone .
(Formulated sample)
The polyglycerol fatty acid esters were used to study combinations capable of preparing a bicontinuous microemulsion former having good stability over time and temperature, including polyglyceryl-10 isostearate and polyglyceryl-10 laurate, which were capable of preparing a bicontinuous microemulsion former having good stability over time and temperature in Test 1.
The trihydric alcohol was selected as glycerin, and the oil component was selected as a cleansing component as in Test 1, and the test was performed.

(Test method)
Using preparation method 1 or preparation method 2, preparations were made by changing the blend and ratio of polyglycerol fatty acid ester, trihydric alcohol, and oily component, and the obtained samples were visually observed based on the above-mentioned confirmation method.

(Test results)
Table 3 shows data on the formulation for preparing a bicontinuous microemulsion forming product in a single trihydric alcohol system.
In the case of a formulation containing only a trihydric alcohol, a bicontinuous microemulsion was obtained by adjusting the amount and composition of the surfactant, and the properties were maintained even after a period of 7 days, showing good stability over time and temperature.

[Test 3]
A test was carried out to prepare bicontinuous microemulsion-forming products by blending naturally derived polyglycerol fatty acid esters with other polyhydric alcohols alone .
(Formulated sample)
The polyglycerol fatty acid esters were used to study combinations capable of preparing a bicontinuous microemulsion former having good stability over time and temperature, including polyglyceryl-1 isostearate and polyglyceryl-10 laurate, which were capable of preparing a bicontinuous microemulsion former having good stability over time and temperature in Test 1.
The other polyhydric alcohols were selected from polyglycerols having tetrahydric or higher hydricities, taking into consideration glycerol which had been used in Test 2 to prepare a bicontinuous microemulsion having good stability over time and temperature.
As in the above test, squalane was selected as the oily component and used as a cleansing component for the test.

(Test method)
Using preparation method 1 or preparation method 2, preparations were made by changing the blend and ratio of polyglycerol fatty acid ester, polyglycerol with 4 or more valences, and oily component, and the samples obtained were visually observed based on the above-mentioned confirmation method.

(Test results)
Table 4 shows the test results of the case where decaglycerin was used among the data of the formulation of the bicontinuous microemulsion forming material prepared in the single system of polyglycerin having 4 or more valences. In the case where decaglycerin was used as the single system of other polyhydric alcohols, the bicontinuous microemulsion forming material was obtained by adjusting the amount and composition of the surfactant, and the properties were maintained even after 7 days, and the stability over time and at temperature was good. Although not shown in the table, the single systems of polyglycerin having 4, 6 and 8 valences also showed good results in terms of stability over time and at temperature, similar to decaglycerin.

[Test 4]
A test was carried out to prepare a bicontinuous microemulsion by mixing naturally derived polyglycerol fatty acid ester with sugar alcohol alone .
(Formulated sample)
The polyglycerol fatty acid esters were used to study combinations capable of preparing a bicontinuous microemulsion former having good stability over time and temperature, using polyglyceryl-10 isostearate and polyglyceryl-10 laurate, which were capable of preparing a bicontinuous microemulsion former having good stability over time and temperature in Test 1.
As the sugar alcohol, hexahydric sorbitol, which is widely used, was selected.
As in the above test, squalane was selected as the oily component and used as a cleansing component for the test.

(Test method)
Using preparation method 1 or preparation method 2, preparations were made by changing the blend and ratio of polyglycerol fatty acid ester, sugar alcohol and oily component, and the samples obtained based on the above-mentioned preparation methods were visually observed.

(Test results)
The data of the formulation in which a bicontinuous microemulsion was prepared using a sugar alcohol, sorbitol, alone is shown in Table 5. In the formulation using a sugar alcohol alone , a bicontinuous microemulsion was obtained by adjusting the amount and composition of the surfactant, and the properties were maintained well over time and temperature even after 7 days.

[Test 5]
A test was conducted to prepare a bicontinuous microemulsion by mixing a naturally derived polyglycerol fatty acid ester with a dihydric alcohol and a trihydric alcohol.
(Formulated sample)
The polyglycerol fatty acid esters were used to study combinations capable of preparing a bicontinuous microemulsion former having good stability over time and temperature, using polyglyceryl-10 isostearate and polyglyceryl-10 laurate, which were capable of preparing a bicontinuous microemulsion former having good stability over time and temperature in Test 1.
As the dihydric alcohol, propanediol was selected, which showed good stability over time and temperature in Test 1, and as the trihydric alcohol, glycerin was selected, which showed good stability over time and temperature in Test 2. The combination of propanediol and glycerin is an example of a formulation in a mixed system of dihydric and trihydric alcohols. As for the oily component, methylheptyl isostearate was selected as a cleaning component.

(Test method)
Using preparation method 1 or preparation method 2, preparations were made by changing the blend and ratio of the polyglycerol fatty acid ester, the mixture of the dihydric alcohol and the trihydric alcohol, and the oily component, and the specimens obtained based on the above-mentioned confirmation method were visually observed. In this test, a temperature condition of 40°C was also added, and the specimens were left to stand in a 40°C incubator, and the changes in state were visually observed every time a specified period of time had passed.

(Test results)
The data of the formulation in which a bicontinuous microemulsion former was prepared using a mixture of propanediol and glycerin is shown in Table 6. In the formulation of the mixture of propanediol and glycerin, a bicontinuous microemulsion former was obtained by adjusting the amount and composition of the surfactant, and in terms of time and temperature stability, the properties were maintained well after at least 10 days at any temperature.

[Comparative Example 1]
In order to compare the results of Test 5 with those of Example 4 described in Patent Document 1, a reproducibility test regarding the formation of a bicontinuous microemulsion structure was carried out.
(Test method)
The formulation of Example 4 of Patent Document 1 is shown in Table 7. A nonionic surfactant was added to an aqueous polyhydric alcohol solution prepared by mixing a polyhydric alcohol other than 1,2-hexanediol (glycerin, a trihydric alcohol, in Table 7) and purified water, followed by addition of an oily component (liquid paraffin), mixing well, and stirring until homogenous. Next, a dihydric alcohol (1,2-hexanediol) was added and dissolved by stirring to obtain a preparation.

The above reproducibility test was carried out, but instead of a transparent one-phase liquid, a bicontinuous microemulsion structure with stable properties was not formed. In addition, separation was observed at temperatures of 25°C and 50°C for the periods shown in Table 7, and the results showed that the stability over time and at temperature was also poor (see Figure 4).

(Tests on time and temperature stability)
It has been known that bicontinuous microemulsion formulations in which all ingredients are naturally derived do not have good stability over time and at high temperatures. Therefore, we have extensively tested and screened ingredients that improve stability over time and at high temperatures. As a result, we have found that fatty acids have a positive effect on the stability over time and at high temperatures of the cosmetic composition according to the present invention. The tests on stability over time and at high temperatures are described below.

[Test 6]
A test was conducted in which a naturally derived polyglycerin fatty acid ester was mixed with a dihydric alcohol and a trihydric alcohol, and then lauric acid was selected from among fatty acids and added to prepare a bicontinuous microemulsion forming material.
(Formulated sample)
The polyglycerol fatty acid esters were used to study combinations capable of preparing a bicontinuous microemulsion former having good stability over time and temperature, using polyglyceryl-10 isostearate and polyglyceryl-10 laurate, which were capable of preparing a bicontinuous microemulsion former having good stability over time and temperature in Test 1.
Similarly, as the dihydric alcohol, propanediol, which had been able to prepare a bicontinuous microemulsion forming product having good stability over time and temperature in Test 1, was used.
Similarly, as the trihydric alcohol, glycerin was used, which had enabled the preparation of a bicontinuous microemulsion forming product having good stability over time and temperature in Test 2.
As in Test 5, methylheptyl isostearate was selected as the cleaning component, and lauric acid, a fatty acid, was selected to act as a temperature-stabilizing component, and the test was performed.

(Test method)
Using Preparation Method 1 or Preparation Method 2, the mixture of polyglycerol fatty acid ester, dihydric and trihydric alcohols was prepared in the same manner as in Test 5, and lauric acid was further added to the obtained sample, which was then visually observed according to the above-mentioned confirmation method. In this test, a temperature condition of 40°C was also added as in Test 5, and the sample was left to stand in a 40°C incubator, and the change in state was visually observed every time a predetermined period of time had passed.

(Test results)
Among the data on the formulation for preparing a bicontinuous microemulsion forming substance in a mixed system of dihydric and trihydric alcohols, Table 8 shows an example of the test results when lauric acid was added to the same formulation as in Test 5, in which the dihydric alcohol was propanediol and the trihydric alcohol was glycerin.
It was found that the incorporation of lauric acid resulted in a bicontinuous microemulsion product with better stability over time and temperature compared to the bicontinuous microemulsion product prepared using a mixture of dihydric and trihydric alcohols (Test 5).

Table 9 shows a comparison of the time and temperature stability of a bicontinuous microemulsion former containing lauric acid as a temperature-stable component (product containing a temperature-stable component) and a bicontinuous microemulsion former not containing a temperature-stable component (product not containing a temperature-stable component). The time period during which the bicontinuous microemulsion structure was maintained is shown for the time and temperature stability.

At temperatures of 25°C and 5°C, the bicontinuous microemulsion structure could be maintained for three months regardless of the presence or absence of a temperature-stable component. At temperatures of 40°C and 50°C, the bicontinuous microemulsion structure could be maintained for at least 10 days even in products without a temperature-stable component, and further, in products with a temperature-stable component, the bicontinuous microemulsion structure could be stably maintained for a period of 25 days even at 50°C. This test showed that even when all the ingredients were naturally derived and no temperature-stable ingredients were added, the bicontinuous microemulsion structure could be stably maintained beyond the time and temperature stability of the bicontinuous microemulsion formed product prepared using a polyglycerol fatty acid ester having a cyclic content in polyglycerol similar to the naturally derived raw material shown in Patent Document 2. Furthermore, it was found that by adding a temperature-stable component, the properties of the bicontinuous microemulsion formed product could be stably maintained even when the temperature of the cosmetic composition according to the present invention changed significantly due to changes in the environmental temperature (room temperature). This resulted in a cosmetic product with excellent stability over time and temperature, with no change in quality even when stored in places with drastic temperature changes, such as bathrooms. Further screening revealed that, among fatty acids, saturated or unsaturated fatty acids with 8 to 22 carbon atoms are particularly preferable as temperature-stable components in bicontinuous microemulsion formulations made entirely of naturally derived ingredients. It was confirmed that the naturally derived cosmetic product of the present invention has good stability over time and at temperature, and thus has characteristics that are significantly different from those of Patent Document 1, which does not mention temperature stability.

[Test 7]
Alternatively, a bicontinuous microemulsion former can be prepared by combining a dihydric alcohol with a tetrahydric, hexahydric, octahydric, dodecahydric or hexahydric sugar alcohol.
(Formulated sample)
In Test 7, the polyglycerol fatty acid esters were examined for combinations capable of preparing a bicontinuous microemulsion former having good stability over time and temperature, using polyglyceryl-10 isostearate and polyglyceryl-10 laurate, which had been able to prepare a bicontinuous microemulsion former having good stability over time and temperature in Test 1.
As an example of the polyhydric alcohol, propanediol was used as the dihydric alcohol, and diglycerin, tetraglycerin, hexaglycerin or decaglycerin was used as the tetrahydric, hexahydric or 12-hydric alcohol to be mixed with the dihydric alcohol.
In addition, a test was conducted using sorbitol, a hexahydric sugar alcohol, as the alcohol to be mixed with the dihydric alcohol.
The oil component was lauric acid as in Test 6, and the test was performed using squalane as a cleansing component.

(Test method)
Using preparation method 1 or preparation method 2, preparations were made by changing the ratio of polyglycerol fatty acid ester, dihydric and tetrahydric or higher polyhydric alcohol or sugar alcohol, and oily component, and the samples obtained were visually observed based on the confirmation method described above.

(Test results)
Table 10 shows the formulations in which the formation of a bicontinuous microemulsion structure was confirmed when a test was performed using a mixture of a dihydric alcohol and a tetrahydric, hexahydric, octahydric or dodecahydric alcohol, or a mixture of a hexahydric sugar alcohol. In all combinations of polyhydric alcohols, a bicontinuous microemulsion product was obtained by adjusting the amount and composition of the surfactant, and the properties were stable even after 7 days in terms of time and temperature stability. Considering the results of Test 6 as well, in order to obtain a bicontinuous microemulsion product with stable properties, in a mixture of a dihydric alcohol and a polyhydric alcohol having a hydric or higher hydric acid, it was found that the blending ratio of the dihydric alcohol to the polyhydric alcohol having a hydric or higher hydric acid tends to increase when the number of hydroxyl groups of the polyhydric alcohol having a hydric or higher hydric acid to be mixed increases (excluding sugar alcohol).

In addition, the dihydric alcohol is changed to, for example, butylene glycol, and bicontinuous microemulsion former is prepared by the above-mentioned test method. In Table 11 showing the results, as in the case of selecting propanediol as dihydric alcohol, when the number of hydroxyl groups of the polyhydric alcohol having 3 or more hydric groups to be mixed increases (excluding sugar alcohol), the mixing ratio of dihydric alcohol to the polyhydric alcohol having 3 or more hydric groups tends to increase. In addition, when comparing the test results using propanediol or butylene glycol as dihydric alcohol, it is found that, as a trend, when the number of carbon atoms of the alkylene group of dihydric alcohol increases, the HLB value of surfactant needs to be adjusted to be smaller (see Tables 10 and 11).

Conventionally, the raw materials for the petroleum-derived polyglycerol fatty acid esters used in cleansing cosmetics contain carcinogenic glycidol and epichlorohydrin, raising safety concerns. On the other hand, the naturally derived cosmetic of the present invention is obtained using only naturally derived raw materials for all of its ingredients, including the polyglycerol fatty acid esters, and therefore takes into consideration safety for the skin compared to cosmetics that use petroleum-derived raw materials, and can be said to be capable of sustained use in terms of raw material supply and safety.

By repeatedly studying the above test method and changing the formulation, the balance between the lipophilicity and hydrophilicity of the naturally derived polyglycerol fatty acid ester was adjusted, and a dihydric or higher polyhydric alcohol, including sugar alcohol, was added to further adjust the balance between the lipophilicity and hydrophilicity in two stages. Furthermore, by devising a specific ratio for the naturally derived polyglycerol fatty acid ester and the amount of oil, a composition region in which the target aqueous phase and oil phase become a transparent one-phase liquid (a region in which a bicontinuous microemulsion structure is formed) could be found. In addition, the properties of the obtained bicontinuous microemulsion-forming product were also sufficiently stable over time and temperature. This solved the problem that a naturally derived polyglycerol fatty acid ester with a cyclic content of more than 25% by weight in the polyglycerin cannot form a bicontinuous microemulsion structure with stable properties.

(The difference in cleansing power between natural and petroleum-derived products when made into a bicontinuous microemulsion)
From the above, it was possible to prepare a bicontinuous microemulsion former having good stability over time and temperature using a naturally derived polyglycerol fatty acid ester. However, when using it as a cleansing cosmetic, it was necessary to verify the difference in performance as a cleansing cosmetic between the bicontinuous microemulsion former prepared using a petroleum-derived polyglycerol fatty acid ester that has been conventionally used.

[Test 8]
Therefore, in the present invention, a naturally derived cleansing cosmetic product prepared by blending a polyglycerol fatty acid ester made from a polyglycerol having a cyclic content of more than 25% by weight of naturally derived polyglycerol as a raw material to prepare a bicontinuous microemulsion former was compared with a petroleum-derived cleansing cosmetic product prepared by blending a petroleum-derived polyglycerol fatty acid ester to prepare a bicontinuous microemulsion former, and a sensory test was conducted to examine the differences in the cleansing effects between the two products.
(Formulated sample)
The formulation for the preparation of a naturally derived cleansing cosmetic having a bicontinuous microemulsion structure, which was carried out based on the results of Test 6, is shown in Table 12, and the formulation for the preparation of a petroleum-derived cleansing cosmetic is shown in Table 13. For Table 13, the formulation described in Example 1 of Patent Document 3 was used.

(Test method)
1. A cleansing cosmetic having a bicontinuous microemulsion structure is prepared using the samples shown in Tables 12 and 13 by Preparation Method 1 or Preparation Method 2. For petroleum-derived cleansing cosmetics, the same Preparation Method 1 or Preparation Method 2 as for natural cleansing cosmetics is used to prepare a cleansing cosmetic having a bicontinuous microemulsion structure.
2. 0.1 g of BB cream (a foundation-based cosmetic with various functions) was applied to an area of 3 cm x 4 cm on the back of the hand and left to stand for 5 minutes.
3. Next, 0.5 g of a natural or petroleum-derived cleansing cosmetic was dropped onto the applied BB cream, and the cosmetic was massaged back and forth 30 times with the fingers to allow it to blend with the BB cream.
4. At that time, the degree of compatibility between the BB cream and the cleansing cosmetic was visually evaluated (evaluation of compatibility).
5. Thereafter, the BB cream with the cleansing cosmetic blended therein was massaged back and forth 10 times under running water to wash it off, and after rinsing, the state of the BB cream remaining on the back of the hand was visually evaluated (evaluation of cleansing power).
6. At the same time, the strength of residual oiliness, etc. was evaluated (evaluation of water washability).

(Evaluation method)
Each evaluation was made on a 5-point scale by 10 subjects, who were blinded so that they could not tell which cleansing cosmetic product they were using.
The sensory scores for each of "compatibility,""cleansingpower," and "water rinsability" were scored as 5 points (good), 4 points (slightly good), 3 points (average), 2 points (slightly poor), and 1 point (poor), and the sensory scores of the 10 subjects were averaged. When the difference between the average values was less than 1 point, the performance was determined to be comparable.

(Test results)
Table 14 shows a comparison of the cleansing performance of natural cleansing cosmetic compositions and petroleum-derived cleansing cosmetic compositions.
In all of the categories of "compatibility,""cleansingpower," and "water washability," the naturally derived cleansing cosmetic exhibited similar performance to the petroleum-derived cleansing cosmetic, with the difference in the average sensory score being less than 1 point. Therefore, it was found that there is no difference in cleansing effect between the conventional cleansing cosmetic using a petroleum-derived polyglycerol fatty acid ester and the cleansing cosmetic using the naturally derived polyglycerol fatty acid ester of the present invention.

(Comparing the cleansing cosmetic properties of dihydric alcohols alone , trihydric alcohols alone , and polyhydric alcohol mixtures)
In addition to the dihydric and trihydric alcohol mixtures, it has been shown by the above-mentioned various tests that a bicontinuous microemulsion former, in which all raw materials are naturally derived and has good stability over time and temperature, can be obtained by using a naturally derived dihydric or trihydric alcohol alone, or a polyhydric alcohol mixture containing at least a dihydric alcohol and a tetrahydric or higher polyhydric alcohol. Therefore, the following tests were carried out to compare the performance of these bicontinuous microemulsion formers as cleansing cosmetics.

[Test 9]
It was decided to compare the performance as a cleansing cosmetic of a bicontinuous microemulsion former using propanediol and glycerin as a mixed system (bivalent and trivalent mixed system) (naturally derived cleansing cosmetic obtained in Test 8), a bicontinuous microemulsion former using propanediol alone (bivalent sole system), and a bicontinuous microemulsion former using glycerin alone (trivalent sole system).
(Formulated sample)
The formulation of a naturally derived cleansing cosmetic composition having a bicontinuous microemulsion structure based on the results of Tests 1 to 6 is shown in Table 15.

(Test method)
1. Using the samples shown in Table 15 and preparation method 1 or preparation method 2, a cleansing cosmetic composition having a bicontinuous microemulsion is prepared.
2. 0.1 g of BB cream was applied to an area of 3 cm x 4 cm on the back of the hand and left to stand for 5 minutes.
3. Next, 0.2 g of a cleansing cosmetic composition containing a mixture of dihydric and trihydric alcohols, a dihydric alcohol alone , or a trihydric alcohol alone was dropped onto the applied BB cream, and the BB cream was massaged back and forth 30 times with a finger to allow the cleansing cosmetic composition to blend with the BB cream.
4. At that time, the degree of compatibility between the BB cream and the cleansing cosmetic was visually evaluated (evaluation of compatibility).
5. Thereafter, the BB cream with the cleansing cosmetic blended therein was massaged back and forth 10 times under running water and then washed off.
6. After rinsing, the remaining state of the BB cream on the back of the hand was visually judged (evaluation of cleansing power), and the strength of residual oiliness, etc. was also evaluated (evaluation of water rinsability).

(Evaluation method)
Each evaluation was performed by 10 subjects on a 5-point scale, similar to Test 8. The subjects were blinded so that they could not tell which cleansing cosmetic preparation they were using.
The sensory scores for each of "compatibility,""cleansingpower," and "water rinsability" were scored as 5 points (good), 4 points (slightly good), 3 points (average), 2 points (slightly poor), and 1 point (poor), and the sensory scores of the 10 subjects were averaged. When the difference between the average values was less than 1 point, the performance was determined to be comparable.

(Test results)
The results of comparing the cleansing power of the bicontinuous microemulsion former of a mixed system of dihydric alcohol and trihydric alcohol with that of a system of dihydric alcohol alone and a system of trihydric alcohol alone are shown in Table 16. In all of the categories of "compatibility,""cleansingpower," and "water washability," the difference in the average sensory scores between the two cleansing cosmetics was less than 1 point, demonstrating that the two cleansing cosmetics performed at the same level.

(Test on the inability to form an O/W microemulsion former by simply mixing a water-soluble component containing water with a bicontinuous microemulsion former)
[Test 10]
Conventionally, a technique is used in which a cosmetic product prepared by using petroleum-derived polyglycerol fatty acid ester as a bicontinuous microemulsion forming material is diluted with water to obtain an O/W microemulsion forming material.However, naturally derived polyglycerol fatty acid ester is a mixture of extremely complicated composition, and it is not easy to control the optimal blending ratio to improve stability over time and temperature, so the technique of forming a bicontinuous microemulsion structure from naturally derived raw materials has not been developed.In addition, the solubilizing power of naturally derived polyglycerol fatty acid ester is lower than that of petroleum-derived polyglycerol fatty acid ester, so the research on the preparation of a bicontinuous microemulsion forming material using only naturally derived raw materials and the preparation of an O/W microemulsion forming material by diluting the bicontinuous microemulsion forming material has not been fully advanced.
Therefore, in the present invention, in a cosmetic product in which a bicontinuous microemulsion former is prepared using a naturally derived polyglycerol fatty acid ester, a formulation and ratio that allows the preparation of an O/W microemulsion former by diluting the cosmetic product with a water-soluble component, including water, is explored.

(Formulated sample)
The formulation of a bicontinuous microemulsion former using a naturally derived polyglycerol fatty acid ester is shown in Table 17, and the formulation of a cosmetic (hereinafter, a naturally derived cosmetic) prepared by diluting the naturally derived bicontinuous microemulsion former with a water-soluble component containing water to obtain an O/W microemulsion former is shown in Table 18.

(Test method)
1. Prepare a bicontinuous microemulsion former using the sample shown in Table 17 using Preparation Method 1 or Preparation Method 2.
2. The bicontinuous microemulsion former was diluted with a water-soluble component including water to prepare the cosmetics shown in Table 18, and the appearance of each cosmetic was visually evaluated.

(Method of Determination)
The transparent naturally derived cosmetic product from which the bicontinuous microemulsion forming product had been prepared was diluted with a water-soluble component containing water. If the product became translucent, it was determined that an O/W microemulsion structure had been formed, and if the product became cloudy, it was determined that an O/W microemulsion structure had not been formed.

By the way, since the bicontinuous microemulsion structure is an association of surfactants in which the interfacial tension between oil and water is close, it is possible to form an O/W microemulsion structure by diluting it with a water-soluble component containing water, using this characteristic. However, it is known that even in the region in which the association can be formed, the O/W microemulsion structure is only formed to a limited extent by diluting the bicontinuous microemulsion structure. In other words, diluting a bicontinuous microemulsion forming material does not necessarily result in the preparation of an O/W microemulsion forming material. In order to demonstrate this, a bicontinuous microemulsion forming material obtained by the formulation described in Patent Document 3, which relates to the preparation of a bicontinuous microemulsion forming material using a petroleum-derived polyglycerol fatty acid ester, was diluted with a water-soluble component containing water to confirm whether or not an O/W microemulsion structure was formed.

(Formulated sample)
The bicontinuous microemulsion former using the petroleum-derived polyglycerol fatty acid ester used the formulation described in Example 1 of Patent Document 3 shown in Table 19. The formulation of the cosmetic (hereinafter, petroleum-derived cosmetic) prepared by diluting the petroleum-derived bicontinuous microemulsion former with a water-soluble component containing water to obtain an O/W microemulsion former is shown in Table 20.

(Test method)
1. Prepare a bicontinuous microemulsion forming material using the sample shown in Table 19 by using Preparation Method 1 or Preparation Method 2, which is the same as the naturally derived cleansing cosmetic preparation.
2. The bicontinuous microemulsion former was diluted with a water-soluble component including water to prepare the cosmetics shown in Table 20, and the appearance of each cosmetic was visually evaluated.

(Method of Determination)
The transparent petroleum-derived cosmetic from which the bicontinuous microemulsion former was prepared was diluted with a water-soluble component containing water. If the product became translucent, it was determined that an O/W microemulsion structure had been formed, and if the product became cloudy, it was determined that an O/W microemulsion structure had not been formed.

(Test results)
Figure 1 shows a comparison of the appearance of the naturally derived cosmetic formulation in Table 18 and the petroleum-derived cosmetic formulation in Table 20. The naturally derived cosmetic formulation in Table 18 (on the right side of the figure) became translucent through microemulsification, and the desired O/W microemulsion structure was formed, whereas the petroleum-derived cosmetic formulation in Table 20 (on the left side of the figure) was cloudy and the desired O/W microemulsion structure could not be formed.
Therefore, it was demonstrated that when a conventional petroleum-derived polyglycerol fatty acid ester was used, diluting the bicontinuous microemulsion former with a water-soluble component containing water did not necessarily result in O/W microemulsion. In O/W microemulsion formation using a naturally derived bicontinuous microemulsion former, an O/W microemulsion structure was formed by diluting the bicontinuous microemulsion former with a water-soluble component containing water. The HLB value of the bicontinuous microemulsion former in this case is preferably in the range of 11 to 14.

(Difference in moisturizing power between natural and petroleum-derived oils when used in O/W microemulsion formulation)
[Test 11]
In this test, the naturally derived cosmetic formulation in Table 18 was compared with the petroleum derived cosmetic formulation in Table 20 to confirm whether there was a difference in moisturizing effect between them.

The formulations of the naturally derived moisturizing cosmetic compositions are shown in Table 21, and the formulations of the petroleum derived moisturizing cosmetic compositions are shown in Table 22.

(Test method)
1. Using Preparation Method 1 or Preparation Method 2 in the same manner as in Test 10, prepare a bicontinuous microemulsion former, and dilute it with water-soluble ingredients including water to prepare a naturally derived moisturizing cosmetic composition having the formulation shown in Table 21 and a petroleum derived moisturizing cosmetic composition having the formulation shown in Table 22.
2. Wash the backs of your hands twice with soap and leave them as they are for at least 15 minutes.
3. Next, 0.1 g of the naturally derived moisturizing cosmetic composition formulated according to Table 21 or the petroleum derived moisturizing cosmetic composition formulated according to Table 22 was applied to the back of the hand, and a sensory evaluation was performed on the four items of "good spreadability," the degree of familiarity with the back of the hand ("friendliness"), "moist feeling after application," and "softness of the skin after application" for each moisturizing cosmetic composition.

(Evaluation method)
Each evaluation was made on a 5-point scale by 10 subjects, who were blinded so that they could not tell which moisturizing cosmetic product they had used.
The sensory scores for each of "good spreadability,""familiarity,""moist feeling after application," and "softness of skin after application" were scored as 5 points as good, 4 points as slightly good, 3 points as normal, 2 points as slightly poor, and 1 point as poor, and the sensory scores of 10 subjects were averaged. When the difference in the average values was less than 1 point, it was determined that the performance was comparable.

(Test results)
The results of comparing the moisturizing effects of a conventional petroleum-derived moisturizing cosmetic composition and the naturally derived moisturizing cosmetic composition of the present invention are shown in Table 23.
In all categories of "good spreadability,""compatibility,""moist feeling after application," and "softness of skin after application," the difference in average sensory scores between the naturally derived moisturizing cosmetic and the petroleum derived moisturizing cosmetic was less than 1 point, and the moisturizing cosmetic was evaluated to have similar performance. Therefore, it was found that there is no difference in moisturizing effect between the moisturizing cosmetic using the conventional petroleum-derived polyglycerol fatty acid ester and the moisturizing cosmetic using the naturally derived polyglycerol fatty acid ester of the present invention.

(Superiority of moisturizing effect with or without oily ingredients)
[Test 12]
In a one-liquid-phase moisturizing cosmetic made of water-soluble components, solubilization by a surfactant is required to blend in an oily component. However, the amount of oily component that can be solubilized is very small. In recent years, by using an O/W microemulsion former, it has become possible to solubilize an oily component without separation even in a one-liquid-phase moisturizing cosmetic, thereby increasing the blending amount. By increasing the amount of oily component, the moisturizing property of a moisturizing cosmetic made mainly of water-soluble moisturizing components and water is further improved. However, in the past, in cosmetics made of naturally derived raw materials for moisturizing, it was not easy to prepare a bicontinuous microemulsion former, and to dilute the former with water to prepare an O/W microemulsion former, so that there was a problem that it was difficult to use an O/W microemulsion former made by using a bicontinuous microemulsion former as a moisturizing cosmetic. Therefore, in this test, the blending and ratio of a cosmetic made only of naturally derived components that can be blended with an oily component for improving moisturizing property while maintaining stability over time and temperature was explored.

(Formulated sample)
Table 24 shows a formulation in which squalane was blended as an oily component in a naturally derived cosmetic product (a product containing squalane), and a formulation in which squalane was not blended as an oily component in a naturally derived moisturizing cosmetic product (a product not containing squalane).

(Test method)
1. Using Preparation Method 1 or Preparation Method 2 in the same manner as in Test 10, a naturally derived bicontinuous microemulsion former is prepared, and diluted with water-soluble ingredients including water to prepare a naturally derived moisturizing cosmetic composition having the formulation shown in Table 24.
2. The face was washed with a facial cleanser and allowed to rest for 15 minutes in an incubator at a temperature of 20° C. and a humidity of 50%, after which the moisture content of the stratum corneum and the amount of transepidermal water loss were measured.
3. After that, apply 0.5g of either the product containing squalane or the product without squalane to each half of the face and let it absorb.
4. The moisture content of the stratum corneum is measured using SKICON-200EX-USB manufactured by Yayoi Co., Ltd.
5. Transepidermal water loss is measured using a Tewmeter TM300 manufactured by CK electronic.
6. Measurements were taken at random intervals from immediately after application up to 3 hours.

(Test results)
The change over time in the moisture content of the stratum corneum when the product containing squalane and the product not containing squalane are used is shown in FIG. 2, where the moisture content before application is taken as "1". The product containing squalane (solid line) tended to have a higher moisture content in the stratum corneum than the product not containing squalane (dashed line) at all times of measurement. In addition, the change over time in the transepidermal water evaporation amount when the product containing squalane and the product not containing squalane are used is shown in FIG. 3, where the moisture evaporation from the skin before application is taken as "1". The product containing squalane (solid line) tended to suppress moisture evaporation from the skin compared to the product not containing squalane (dashed line) at all times of measurement. This confirmed that the O/W microemulsion formed product containing squalane, an oily component capable of suppressing the amount of transepidermal water evaporation, has superior moisturizing properties compared to the product not containing squalane. Therefore, the naturally derived moisturizing cosmetic composition according to the present invention was able to obtain a cosmetic composition containing only naturally derived components that can be blended with oily components to improve moisturizing properties while maintaining temperature stability over time.

Specific examples of naturally derived cosmetics for use on the skin include, but are not limited to, cleansing cosmetics, facial cleansers, lotions, serums, gels, and other preparations.

The polyglycerol fatty acid ester used in the present invention, which is made from a polyglycerol having a naturally occurring cyclic content of more than 25% by weight, can be obtained by the following method.
1. First, polyglycerin is obtained by dehydrating and condensing glycerin, which is one of the general methods for preparing polyglycerin, using naturally occurring glycerin as a raw material. The polyglycerin obtained by this preparation method has the characteristic of containing cyclic polyglycerin, which is an isomer of linear polyglycerin (the content of the cyclic polyglycerin analyzed using LC/MS is described in "FRAGRANCE JOURNAL 2003-12, pp. 106-112").
2. Next, the polyglycerol having a cyclic content of more than 25% by weight is esterified with a naturally occurring fatty acid to obtain a naturally occurring polyglycerol fatty acid ester.

By using a polyglycerol fatty acid ester made from a polyglycerol having a cyclic content of more than 25% by weight, cosmetics exhibiting the effects aimed at by the present invention can be reproducibly prepared.
More specifically, it refers to a polyglycerol fatty acid ester obtained by esterifying a polyglycerol having a degree of polymerization of 2 or more, which is obtained from naturally occurring glycerol having a content of cyclic isomers exceeding 25% by weight, with a saturated or unsaturated, or mixed saturated and unsaturated fatty acid having 8 to 22 carbon atoms.
The average degree of polymerization (n) is a value calculated from the hydroxyl value, and is calculated from the following Equations 1 and 2.
Molecular weight=74n+18...Formula 1
Hydroxyl value = 56110 (n + 2) / molecular weight ... formula 2
The hydroxyl value in formula 2 is a value calculated from the results of a test conducted in accordance with the "Standard Testing Method for the Physical Properties of Fats and Oils" (established by the Japan Oil Chemists' Association). Specifically, it is expressed as the number of milligrams of potassium hydroxide (KOH) required to neutralize the acetic acid bonded to the hydroxyl group when 1 g of a sample is acetylated with an acetic anhydride-pyridine solution.

The fatty acids constituting the polyglycerol fatty acid ester include one or more selected from linear or branched saturated and unsaturated fatty acids. Examples include triglyceryl monocaprate, tetraglyceryl monolaurate, hexaglyceryl monolaurate, decaglyceryl monolaurate, decaglyceryl dilaurate, hexaglyceryl monomyristate, decaglyceryl monomyristate, decaglyceryl dimyristate, hexaglyceryl monopalmitate, decaglyceryl monopalmitate, decaglyceryl dipalmitate, hexaglyceryl monostearate, decaglyceryl monostearate, diglyceryl diglyceryl ester ... decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl monostearate, decaglyceryl Examples of the polyglyceryl stearate include decaglyceryl stearate, hexaglyceryl monooleate, decaglyceryl monooleate, decaglyceryl dioleate, hexaglyceryl monoisostearate, decaglyceryl monoisostearate, decaglyceryl diisostearate, decaglyceryl mono(isostearate/oleate), decaglyceryl di(laurate/oleate), and hexaglyceryl mono(caprate/isostearate). One or more of these may be used. Among the above, polyglycerol fatty acid esters having an HLB value of more than 10.0 are particularly preferred, but it is also possible to use a polyglycerol fatty acid ester having an HLB value of less than 10.0 in combination with a polyglycerol fatty acid ester having an HLB value of more than 10.0 in a ratio such that the HLB value is 10.0 or more.

Examples of dihydric, trihydric or higher polyhydric alcohols or sugar alcohols used in the cosmetic composition according to the present invention include naturally derived dihydric polyhydric alcohols such as propanediol, butylene glycol, pentylene glycol, and heptanediol, naturally derived trihydric or higher polyhydric alcohols such as glycerin, diglycerin, triglycerin, tetraglycerin, hexaglycerin, and decaglycerin, and naturally derived sugar alcohols such as erythritol, xylitol, sorbitol, trehalose, sucrose, maltitol, and mannitol. Among these, propanediol, butylene glycol, and glycerin are preferred.

The temperature-stable components used in the cosmetic composition according to the present invention include saturated or unsaturated fatty acids having 8 to 22 carbon atoms, which are a type of oil component. Examples include fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, palmitoleic acid, arachidic acid, arachidonic acid, isostearic acid, undecylenic acid, erucic acid, oleic acid, lanolin fatty acid, linoleic acid, linolenic acid, hydroxystearic acid, polyhydroxystearic acid, ricinoleic acid, polyricinoleic acid, safflower oil fatty acid, rice bran fatty acid, tall oil fatty acid, coconut fatty acid, eicosapentaenoic acid, and docosahexaenoic acid, and one or more of these may be used. Among these, capric acid, lauric acid, and myristic acid are particularly preferred.

Naturally derived oily ingredients used in the cosmetic composition of the present invention include, for example, squalane, hydrocarbon oils such as (C13-15) alkanes, apricot kernel oil, avocado oil, linseed oil, almond oil, camellia seed oil, Argania spinosa kernel oil, olive fruit oil, cacao butter, kaya seed oil, cucumber oil, kukui nut oil, sesame oil, wheat germ oil, rice bran oil, rice germ oil, corn oil, safflower oil, shea butter, soybean oil, tea seed oil, tea leaf oil, tea seed oil, evening primrose oil, camellia seed oil, corn germ oil, carrot seed oil, and Vegetable oils and fats such as oleic acid, malt oil, grape seed oil, pearl barley oil, palm oil, palm kernel oil, castor oil, sunflower seed oil, hazelnut oil, macadamia seed oil, mango seed oil, meadowfoam oil, cottonseed oil, coconut oil, peanut oil, rosehip oil, camellia oil, rapeseed oil, jojoba seed oil, clove oil, lavender oil, rosemary oil, turpentine, and eucalyptus oil; orange roughy oil, turtle oil, horse oil, beef tallow, cod liver oil, mink oil, egg yolk oil, liquid lanolin, and other animal oils; caprylic alcohol, lauryl Alcohol, myristyl alcohol, cetanol, cetostearyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, octyldodecanol, octyl alcohol, decyl alcohol, decyltetradecanol, arachidyl alcohol, hexyldecanol, hydrogenated rapeseed oil alcohol, behenyl alcohol, lanolin alcohol and other higher alcohols, chimyl alcohol, selachyl alcohol, batyl alcohol and other alkyl glyceryl ethers, cholesterol, dihydrocholesterol, phytosterol and other sterols, beeswax, spermaceti wax, carnauba wax, candelilla wax, montan wax, Japan wax, rice wax, lanolin wax, Ibota wax and other waxes, avocado oil fatty acid ethyl, ethyl isostearate, methylheptyl isostearate, hexyldecyl isostearate, octyldodecyl isostearate, isocetyl isostearate, isostearyl isostearate, glyceryl isostearate, cholesterol isostearate Teryl, batyl isostearate, phytosteryl isostearate, triisostearin, hydrogenated castor oil isostearate, octyldodecyl erucate, pentaerythritol octanoate, cetyl octanoate, isocetyl octanoate, cetearyl octanoate, stearyl octanoate, isostearyl octanoate, ethyl oleate, oleyl oleate, glyceryl trioleate, octyldodecyl oleate, decyl oleate, cetyl caprate, cetyl caprylate, glyceryl tricaprylate , octyldodecyl erucate, hexyldecyl stearate, cholesteryl stearate, isocetyl stearate, stearyl stearate, batyl stearate, octyldodecyl stearoyloxystearate, hydrogenated castor oil dimer dilinoleate, diglycerin/dilinoleic acid/hydroxystearic acid copolymer, polyglyceryl-2 isostearate/dimer dilinoleic acid copolymer, cholesteryl hydroxy fatty acid, glyceryl triisostearate, diisostearin Diglyceryl Triisostearate, Diglyceryl Tetraisostearate, Decaglyceryl Nonisostearate, Decaglyceryl Decaisostearate, Caprylic/Capric Triglyceride, Glyceryl Trimyristate, Cetyl Lactate, Myristyl Lactate, Lauryl Lactate, Octyldodecyl Lactate, Isostearyl Palmitate, Isopropyl Palmitate, Octyl Palmitate, Methylheptyl Palmitate, Cetyl Palmitate, Isocetyl Palmitate, Hydroxy Examples of the oils include ester oils such as cholesteryl stearate, methylheptyl myristate, isocetyl myristate, isostearyl myristate, isopropyl myristate, octyldodecyl myristate, myristyl myristate, hexyl laurate, methylheptyl laurate, isostearyl laurate, cholesteryl lanoline fatty acid, tocopherol linoleate, octyldodecyl ricinoleate, diisostearyl malate, and γ-oryzanol. One or more of these oils may be used. Among these, methylheptyl isostearate and squalane are particularly preferred.

In addition, it is preferable that a temperature-stable component is blended into a cleansing cosmetic product made of a bicontinuous microemulsion-forming product using the naturally derived polyglycerol fatty acid ester of the present invention. However, as a result of investigating whether ethanol, which is used as a cooling agent, solvent, base material, etc. in cosmetics, can be blended into a bicontinuous microemulsion-forming product made of naturally derived polyglycerol fatty acid ester, it was found that it is better not to include it because it can have a negative effect on temporal and temperature stability.

The naturally derived cosmetic of the present invention may contain, in addition to the polyglycerol fatty acid ester made from polyglycerol having a cyclic content of more than 25% by weight, which is the blending component according to the present invention, a polyhydric alcohol alone or a polyhydric alcohol mixture containing at least a dihydric alcohol and a trihydric or higher polyhydric alcohol, a temperature-stable component, an oily component, and water, if it is a cosmetic preparation, for example, other oily components, other surfactants, moisturizers, preservatives/bactericides, powder components, ultraviolet absorbers, antioxidants, colorants, fragrances, other physiologically active components, and the like, as needed. Furthermore, so long as the efficacy and characteristics of the naturally derived cosmetic of the present invention are not impaired, naturally derived ingredients that are generally used as cosmetic raw materials, for example, mucopolysaccharides such as sodium hyaluronate and sodium chondroitin sulfate, water-soluble polymers such as gum arabic, sodium alginate, carrageenan, karaya gum, agar, xanthan gum, guar gum, quince seed gum, tamarind gum, locust bean gum, and tragacanth gum, pigments such as β-carotene, astaxanthin, and lutein, sphingophospholipids such as ceramide, flavonoids such as flavones, flavonols, isoflavones, and anthocyans, polyphenols such as ferulic acid, oil-based vitamins, amino acids, plant extracts, essential oils, pH adjusters, preservatives, and the like, can also be combined and blended into the cosmetic.

When the naturally derived cosmetic of the present invention is selected as a cleansing cosmetic, it can be prepared by adding, for example, methylheptyl isostearate. An example of the formulation of the cleansing cosmetic is shown in Table 25. The formulation in Table 25 is an example and is not limited thereto.

When the naturally derived cosmetic of the present invention is selected as a gel cream, it can be prepared by adding a thickener, etc. An example of the formulation of a naturally derived cosmetic having a bicontinuous microemulsion structure before the addition of a thickener is shown in Table 26, and an example of the formulation of a gel cream with a thickener added is shown in Table 27. The formulations in Tables 26 and 27 are only examples and are not limited to these.

The naturally derived cosmetic product of the present invention uses all of its ingredients from naturally derived raw materials, making it possible to provide a cosmetic product that is safer for the skin, more environmentally friendly, and has the same effects as petroleum-derived cosmetics, compared to cosmetics made from petroleum-derived raw materials.

Claims (3)

at least,
The polyglycerol used as a raw material has a cyclic content of more than 25% by weight and an average degree of polymerization of 3 to 10, and has at least one saturated or unsaturated fatty acid residue having 10 to 18 carbon atoms,
a polyglycerol fatty acid ester having a weighted average HLB value of more than 10 when one or more of the polyglycerol fatty acid esters are used in combination;
a polyhydric alcohol mono-system which is a dihydric alcohol having 3 to 7 carbon atoms, glycerin or a polyglycerin having an average degree of polymerization of 2 to 10, or a sugar alcohol, or a polyhydric alcohol mixture system which is a mixture of a dihydric alcohol having 3 to 7 carbon atoms and at least one of glycerin or a polyglycerin having an average degree of polymerization of 2 to 10, or a sugar alcohol;
Oily ingredients,
water and,
As a compounding ingredient,
The polyglycerol fatty acid ester is
Contains 24.2% to 31.0%
The sugar alcohol is
selected from erythritol, xylitol, sorbitol, trehalose, sucrose, maltitol, or mannitol;
A bicontinuous microemulsion structure was formed.
The blended ingredients are
It is made from natural ingredients,
A naturally derived cosmetic characterized by: Furthermore , the temperature-stable component contains at least one saturated or unsaturated fatty acid having 8 to 22 carbon atoms.
The naturally derived cosmetic composition according to claim 1, The naturally derived cosmetic composition according to claim 1 or 2,
Naturally derived water-soluble ingredients, including water,
Combined with
Having an O/W microemulsion structure;
A naturally derived moisturizing cosmetic characterized by:

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