JP7624869B2 - Water-in-oil emulsion cosmetics - Google Patents

Description

The present invention relates to a water-in-oil emulsion cosmetic.

Water-in-oil emulsion cosmetics have been proposed as base makeup cosmetics and sunscreen cosmetics. For example, Patent Document 1 discloses a technology for a water-in-oil emulsion cosmetic that contains (A) 0.1 to 5 mass % of a lipophilic polyoxyalkylene-modified silicone, (B) 0.02 to 5 mass % of a silicone polymer having a three-dimensional crosslinked structure, (C) 0.5 to 16.88 mass % of a silicone oil, and (D) 83 to 95 mass % of an aqueous phase component, as a cosmetic that has good stability over time, has an unprecedented moist feel when applied, spreads well, and is less sticky after use.
Patent Document 2 discloses a technology for a water-in-oil emulsion having excellent stability, which contains a silicone surfactant, a silicone elastomer powder, and an organo-modified clay.

JP 2003-055141 A Patent No. 6465961

The objective is to provide a water-in-oil emulsion cosmetic that has good stability and a good feel when used.

The main configuration of the present invention is as follows.
(1) A water-in-oil emulsion cosmetic comprising (A) to (F), wherein the oil (B) comprises a silicone oil (B-a) and an oil other than the silicone oil (B-b), the silicone gel composition (C) is a silicone gel composition consisting of a crosslinked silicone polymer (C-a) and a silicone oil (C-b), and the mass ratio of the total amount of the silicone oil (B-a) and the silicone oil (C-b) [(B-a)+(C-b)] to the oil other than the silicone oil (B-b) [(B-a)+(C-b)]:(B-b) is 4:1 to 9.5:1.
(A) Bis(PEG/PPG-14/14) dimethicone, (B) oil, (C) silicone gel composition, (D) inorganic powder, (E) polyhydric alcohol, and (F) water. (2) The water-in-oil emulsion cosmetic according to (1), wherein the total amount of (Ba) silicone oil, (B-b) oil other than silicone oil, and (C-b) silicone oil is 15 to 35% by mass based on the total amount of the composition.
(3) The water-in-oil emulsion cosmetic according to (1) or (2), wherein the inorganic powder (D) is 10 to 20% by mass.
(4) The water-in-oil emulsion cosmetic according to any one of (1) to (3), having a viscosity of 17,000 to 75,000 mPa·s as measured with a Brookfield viscometer (rotor No. 4, 12 rpm, 30 seconds, 25° C.).

The water-in-oil emulsion cosmetic composition of the present invention is a cosmetic composition with excellent stability, with little change in viscosity even after storage at 25°C for one month, and no oil separation even after storage at 25°C and 40°C for one month. It spreads well on the skin, feels smooth and non-sticky after application, and is a cosmetic composition with excellent usability.

The ingredients used in this invention are described below.

(A) Bis(PEG/PPG-14/14) Dimethicone (A) Bis(PEG/PPG-14/14) Dimethicone (cosmetic labeling name) of the present invention is a silicone-based emulsifier. The structure is as shown in Chemical Formula 1.

式中、ｍ＝１００～１１０であり、Ｒ、Ｒ（１）はポリオキシエチレンとポリオキシプロピレン鎖からなり、平均重合度１４である。
市販品としては、ＥＶＯＮＩＫ社の、ＡＢＩＬ ＥＭ ９７ Ｓが例示できる。ＡＢＩＬ ＥＭ ９７ Ｓは、ビス（ＰＥＧ／ＰＰＧ－１４／１４）ジメチコンと、ジメチコンの混合原料である。（Ａ）ビス（ＰＥＧ／ＰＰＧ－１４／１４）ジメチコンは、１～５質量％含有すると好ましい。

In the formula, m is 100 to 110, R and R(1) are composed of polyoxyethylene and polyoxypropylene chains, and the average degree of polymerization is 14.
An example of a commercially available product is ABIL EM 97 S manufactured by EVONIK. ABIL EM 97 S is a mixed raw material of bis(PEG/PPG-14/14) dimethicone and dimethicone. (A) Bis(PEG/PPG-14/14) dimethicone is preferably contained in an amount of 1 to 5% by mass.

(B) Oil The (B) oil of the present invention may be any oil that can be blended into cosmetics. In the water-in-oil emulsion cosmetic of the present invention, silicone oil (B-a) and other oil (B-b) are distinguished and contained in a specific ratio. Examples of silicone oil (B-a) and oil other than silicone oil (B-b) are shown below. Note that silicone oil is also contained in the (C) silicone gel composition described later, but the silicone oil in the (C) silicone gel composition is referred to as silicone oil (C-b). Examples of (B-a) silicone oil include dimethylpolysiloxane (dimethicone), methylphenylpolysiloxane (diphenylsiloxyphenyltrimethicone, diphenyldimethicone), cetyl PEG/PPG-10/1 dimethicone, (acrylates/ethylhexyl acrylate/dimethicone methacrylate) copolymer, etc. Examples of volatile silicone oil include cyclopentasiloxane, etc. Diphenylsiloxyphenyl trimethicone, cyclopentasiloxane, dimethicone, cetyl PEG/PPG-10/1 dimethicone, (acrylates/ethylhexyl acrylate/dimethicone methacrylate) copolymer are particularly preferred.
Examples of oils other than silicone oils (B-b) include ester oils, fats and oils, hydrocarbon oils, etc. Examples of ester oils include cetyl ethylhexanoate, 1,3-butylene glycol diisononanoate, 1,3-butylene glycol di-2-ethylhexanoate, dipropylene glycol diisononanoate, dipropylene glycol di-2-ethylhexanoate, isononyl isononanoate, isotridecyl isononanoate, tri(caprylic acid/capric acid)glyceryl, tri-2-ethylhexanoate glyceryl (triethylhexanoin), glyceryl tricaprate, glyceryl triisostearate, neopentyl glycol dicaprate, ethylhexyl palmitate, isostearyl neopentanoate, myristoyl methyl-β-alanine (phytosteryl/decyltetradecyl), dipentaerythrityl tripolyhydroxystearate, etc. Examples of oils and fats include liquid oils and fats such as camellia oil, evening primrose oil, macadamia nut oil, olive oil, rapeseed oil, corn oil, sesame oil, jojoba oil, germ oil, wheat germ oil, cacao butter, coconut oil, palm oil, palm kernel oil, etc. Examples of hydrocarbon oils include liquid paraffin, squalene, squalane, etc. Particularly preferred are triethylhexanoin, cetyl ethylhexanoate, squalane, tri(caprylic acid/capric acid)glyceryl, isotridecyl isononanoate, and dipentaerythrityl tripolyhydroxystearate. Ultraviolet absorbents and vitamin E are not included in the category of oil (B) of the present invention. However, this does not limit the incorporation of ultraviolet absorbents and vitamin E as optional components within a range that does not impair the effects of the present invention. Silicone oil, stearic acid, and the like used for coating or compounding the (D) inorganic powder or other powders that are optionally blended, which will be described later, are not included in the category of the (B) oil of the present invention.

(C) Silicone Gel Composition The (C) silicone gel composition of the present invention is composed of a crosslinked silicone polymer (Ca) and a silicone oil (C-b), and the crosslinked silicone polymer (Ca) is dispersed and swollen in the silicone oil (C-b). The crosslinked silicone polymer is a fine particle with a tertiary crosslinked structure, and has excellent swelling properties in silicone oil.
Examples of the crosslinked silicone polymer (Ca) include dimethicone/vinyl dimethicone crosspolymer and dimethicone/(PEG-10/15) crosspolymer.
The crosslinked silicone polymer (Ca) is preferably a dimethylpolysiloxane crosslinked with divinyldimethylpolysiloxane, such as a (dimethicone/vinyldimethicone) crosspolymer.
Examples of silicone oil (C-b) include dimethicone and cyclopentasiloxane. In the present invention, a commercially available product in which a crosslinked silicone polymer (C-a) is previously swollen in silicone oil (C-b) may be used. Examples of commercially available products include KSG-15, KSG-16, and KSG-210 manufactured by Shin-Etsu Chemical Co., Ltd. KSG-15 is a mixed raw material consisting of 4 to 10 mass% of (dimethicone/vinyl dimethicone) crosspolymer, which is a crosslinked silicone polymer (C-a), and 90 to 96 mass% of cyclopentasiloxane, which is a silicone oil (C-b). KSG-16 is a mixed raw material consisting of 20 to 30 mass% of (dimethicone/vinyl dimethicone) crosspolymer, which is a crosslinked silicone polymer (C-a), and 70 to 80 mass% of dimethicone, which is a silicone oil (C-b). KSG-210 is a mixed raw material consisting of 20 to 30% by mass of (Ca) (dimethicone/(PEG-10/15) crosspolymer) and 70 to 80% by mass of silicone oil (Cb) dimethicone.
In the present invention, it is preferable to blend the silicone gel composition (C) so that the crosslinked silicone polymer (Ca) is 0.01 to 0.5% by mass, more preferably 0.1 to 0.3% by mass, based on the total amount of the water-in-oil emulsion cosmetic.

In the water-in-oil emulsion cosmetic of the present invention, it is important that the total amount of silicone oil (B-a) and silicone oil (C-b) [(B-a) + (C-b)] and the mass ratio of oil other than silicone oil (B-b) [(B-a) + (C-b)]:(B-b) is preferably 4:1 to 9.5:1, more preferably 4:1 to 9.3:1, and even more preferably 4:1 to 9.2:1. If it is outside this range, there is a high risk of the stability and usability being impaired, which is undesirable.

In the water-in-oil emulsion cosmetic of the present invention, the total amount of silicone oils [(B-a) + (C-b)] and the total amount of oils other than silicone oils (B-b) is preferably 15 to 35% by mass, more preferably 15 to 33% by mass, based on the total amount of the water-in-oil emulsion cosmetic. This range is preferable because it provides good stability and a good feel when used.

(D) Inorganic powder The inorganic powder of the present invention is not particularly limited as long as it is one that is normally used in cosmetics. As the inorganic powder, a pigment is preferable. Examples of the inorganic powder include titanium oxide and talc, which are white pigments, iron oxide, which is a yellow pigment, iron oxide, which is a black pigment, iron oxide, which is a red pigment, such as red iron oxide, pearl pigments, such as mica, iron oxide-coated mica, and iron oxide-coated mica titanium, gunjo, chromium oxide, kaolin, boron nitride, and silica. Surface-treated powders that have been subjected to silicone treatment or fluorine treatment may be used as the inorganic powder. Also, commercially available dispersions that have been previously dispersed in silicone oil or the like may be used.
Fine particles such as titanium oxide, zinc oxide, cerium oxide, and zirconium oxide are also included in the inorganic powder.
The blending amount of the inorganic powder is preferably 10 to 25 mass %, more preferably 10 to 20 mass %, in terms of pure content.

(E) Polyhydric alcohol Examples of the polyhydric alcohol of the present invention include glycerin, diglycerin, 1,3-butylene glycol (BG), dipropylene glycol, and 1,2-pentanediol. 1,3-butylene glycol (BG) and 1,2-pentanediol are particularly preferred. The blending amount of the polyhydric alcohol is preferably 3 to 15% by mass, more preferably 5 to 15% by mass, based on the total amount of the cosmetic.

(F) Water In the present invention, the blending amount of (F) water is preferably from 35 to 60% by mass, and more preferably from 39 to 60% by mass, based on the total amount of the cosmetic.

Furthermore, in the present invention, the total amount of (E) polyhydric alcohol and (F) water is preferably 40 to 65% by mass, more preferably 45 to 65% by mass, based on the total amount of the cosmetic.

The preferred blend amounts of the water-in-oil emulsion cosmetic of the present invention are as follows.
(Preferable blending amount of water-in-oil emulsion cosmetic)
(A) Bis(PEG/PPG-14/14) dimethicone 1 to 5% by mass
Among the oils (B), the oil other than the silicone oil (B-b) is 1 to 5 mass %
(C) The silicone gel composition contains 0.01 to 0.5 mass % of a crosslinked silicone polymer (Ca).
[(Ba)+(Cb)] Silicone oil: 13 to 24% by mass
The total amount of silicone oil [(Ba) + (Cb)] and oil other than silicone oil (Bb) is 15 to 35% by mass.
(D) Inorganic powder 10-25% by mass
(E) Polyhydric alcohol 5 to 15% by mass
(F) Water 35-60% by mass

(viscosity)
The cosmetic is filled into a glass container having a diameter of 3 cm, and the viscosity measured with a B-type viscometer (No. 4 rotor, 12 rpm, 30 seconds, 25°C) is preferably 17,000 to 75,000 mPa·s. It is even more preferable that the viscosity on the day after preparation is 20,000 to 75,000 mPa·s.

The water-in-oil emulsion cosmetic of the present invention may contain any component within the scope of not impairing the effects of the present invention. For example, it may contain spherical powders such as polyethylene powder, preservatives, sequestering agents, moisturizing agents such as hyaluronic acid, fragrances, pH adjusters, etc. It may also contain other medicinal and biologically active components such as skin activators, blood circulation promoters, resident flora control agents, active oxygen scavengers, anti-inflammatory agents, whitening agents, and bactericides.

The properties of the water-in-oil emulsion cosmetic of the present invention make it ideal as a base cosmetic.

The water-in-oil emulsion cosmetic of the present invention will be specifically described below.
The water-in-oil emulsion cosmetics of Examples 1 to 8 and Comparative Examples 1 to 13 were prepared by a conventional method. The compositions and evaluation results of the Examples are shown in Table 1, and the compositions and evaluation results of the Comparative Examples are shown in Table 2. The units of composition are % by mass. Viscosity, viscosity change rate, appearance observation, and usability were measured and evaluated.

<Viscosity>
The cosmetic was filled into a glass container with a diameter of 3 cm and stored at 25° C. The viscosity the next day and one month later were measured using a B-type viscometer (No. 4 rotor, 12 rpm, 30 seconds, 25° C.). The units in the table are mPa·s.
<Viscosity change rate>
The viscosity change rate (%) was calculated from (viscosity after one month/viscosity on the next day)×100 and evaluated according to the following criteria.
(Criteria) ◎: Viscosity change rate at 25°C less than ±10% ◯: Viscosity change rate at 25°C from ±10% to less than ±15% ×: Viscosity change rate at 25°C of 15% or more It has been found that if the viscosity change rate after one month at 25°C is less than 15%, consumers will not notice the change during use. Therefore, a viscosity change rate of less than 15% can be judged to be excellent stability.

<Appearance Observation>
The cosmetic preparation was filled into a glass container having a diameter of 3 cm, and stored at 25° C. and 40° C. for one month, respectively. The change in appearance was visually observed and evaluated according to the following criteria.
◯: No oil separation at either 25°C or 40°C ×: Oil separation observed at either 25°C or 40°C

<Usability (spreadability, smoothness, stickiness)>
(Stretch)
The cosmetic was spread with fingers, and the spreadability was evaluated according to the following criteria. The spreadability refers to the ease with which the cosmetic can be spread.
◎: Strongly stretchable 〇: Slightly stretchable ×: No stretchable

(Smoothness)
The cosmetic was applied to the back of the hand, and the feel during application was evaluated according to the following criteria: Smoothness refers to the lack of stickiness when the cosmetic was spread.
◎: Smooth ◯: Slightly smooth ×: Not smooth

(Non-sticky)
After applying the cosmetic preparation to the back of the hand, the lack of stickiness was evaluated according to the following criteria.
◎: No stickiness ○: Almost no stickiness △: Slightly sticky ×: Sticky

(result)
As shown in the lower part of Table 1, the water-in-oil emulsion cosmetics of Examples 1 to 9 were visually confirmed to have no oil separation after storage for one month at 25°C and 40°C. The viscosity change rate after storage for one month at 25°C was less than 15%, and it was determined that the quality was very high. It was also confirmed that the feel in use (good spreadability, smoothness, and non-stickiness) was good.
On the other hand, in the case of the composition in Table 2 which does not conform to the constitution of the present invention, one or more items were unsatisfactory, and a cosmetic preparation of the desired quality was not obtained.
From the above, it was found that the composition of the present invention can provide a water-in-oil emulsion cosmetic with excellent stability, with little change in viscosity over time and no oil separation over time.The cosmetic obtained spreads well when applied to the skin, is smooth, non-sticky, and has an excellent feel when used.

In general, controlling viscosity is extremely difficult in compositions that contain a high amount of inorganic powder. In cases where the viscosity increases over time, there is a risk that the product will be difficult to dispense from the container, or that the feel of the product will differ between when the product is first used and after a certain amount of time has passed, which could lead to consumer complaints.
In addition, in cases where the viscosity decreases over time, there is a risk of powder settling. In order to prevent the viscosity from increasing over time, various companies have attempted to design the viscosity to be low in advance, but in such cases, a complicated method is required, such as placing a stirring ball in the container for stirring in advance and having the consumer shake the container just before use to mix the settled powder before use. In this situation, it is highly significant that the configuration of the present invention has been able to provide a cosmetic preparation that is comfortable to use and has excellent stability with little change in the viscosity of the composition.

Formulation examples of the water-in-oil emulsion cosmetic of the present invention are shown below.
(Formulation Example 1: Base cosmetic (water-in-oil emulsion cosmetic)
(Ingredients) (% by mass)
1. Bis(PEG/PPG-14/14) Dimethicone 2.55
2. Dimethicone 0.45
3. Cyclopentasiloxane 10.535
4. Diphenylsiloxyphenyl trimethicone 10
5. Isotridecyl isononanoate 3
6. (Dimethicone/vinyl dimethicone) crosspolymer 0.15
7. Cyclopentasiloxane 2.85
8. Silicone-treated titanium dioxide fine particles 10
9. Silicone-treated iron oxide 0.276
10. Silicone-treated talc 2.689
11. Silicone-treated pigment-grade titanium dioxide 2.5
12. BG10
13. Sodium chloride 1.57
14. Water 43.43

The base cosmetic of Formulation Example 1 was prepared by a conventional method. The base cosmetic of Formulation Example 1 was a cosmetic with excellent stability, with a viscosity change of less than 15% after storage for one month at 25° C. and no oil separation observed after storage for one month at 25° C. and 40° C. Furthermore, when applied to the skin, it spread well, was smooth, and had an excellent feel without stickiness.

Formulation Example 2 Foundation (water-in-oil emulsion cosmetic)
(Ingredients) (% by mass)
1. Bis(PEG/PPG-14/14) Dimethicone 3.4
2. Dimethicone 0.6
3. Cyclopentasiloxane 10.535
4. Diphenylsiloxyphenyl trimethicone 8
5. Triethylhexanoin 5
6. (Dimethicone/vinyl dimethicone) crosspolymer 0.15
7. Cyclopentasiloxane 2.85
8. Silicone-treated titanium dioxide microparticles 10
9. Silicone-treated iron oxide 1.5
10. Silicone-treated talc 0.465
11. Silicone-treated pigment-grade titanium dioxide 2.5
12. BG10
13. Sodium chloride 1.57
14. Water 43.43

The foundation of Formulation Example 2 was prepared by a conventional method. The foundation of Formulation Example 2 was a cosmetic preparation with excellent stability, with a viscosity change of less than 15% after storage for one month at 25° C. and no oil separation observed after storage for one month at 25° C. and 40° C. Furthermore, when applied to the skin, it spread well, was smooth, and had an excellent feel when used, with no stickiness.

By adopting the configuration of the present application, it is possible to provide a water-in-oil emulsion cosmetic that has little change in viscosity, does not experience oil separation, and is highly stable. It is also possible to provide a water-in-oil emulsion cosmetic that spreads well when applied to the skin, is smooth, non-sticky, and has an excellent feel when used.

Claims (4)

The silicone gel composition (C) comprises (A) to (F), the oil (B) comprises (Ba) a silicone oil and (B-b) an oil other than silicone oil, and the silicone gel composition (C) is a silicone gel composition comprising (Ca) a crosslinked silicone polymer and (C-b) a silicone oil,
A water-in-oil emulsion cosmetic, in which the mass ratio [(B-a)+(C-b)] of the total amount of silicone oil (B-a) and silicone oil (C-b) [(B-a)+(C-b)] to oil other than silicone oil (B-b) [(B-a)+(C-b)]:(B-b) is 4:1 to 9.5:1.
(A) Bis(PEG/PPG-14/14) dimethicone (B) Oil (C) Silicone gel composition (D) Inorganic powder (E) Polyhydric alcohol (F) Water The water-in-oil emulsion cosmetic according to claim 1, wherein the total amount of (B-a) silicone oil, (B-b) oil other than silicone oil, and (C-b) silicone oil is 15 to 35% by mass based on the total amount of the composition. The water-in-oil emulsion cosmetic according to claim 1 or 2, wherein (D) the inorganic powder is 10 to 20% by mass. The water-in-oil emulsion cosmetic according to any one of claims 1 to 3, having a viscosity of 17,000 to 75,000 mPa·s as measured with a B-type viscometer (rotor No. 4, 12 rpm, 30 seconds, 25°C).