CN109069357B

CN109069357B - Oil-in-water type emulsion cosmetic

Info

Publication number: CN109069357B
Application number: CN201780025626.XA
Authority: CN
Inventors: 香取崇广; 八卷悟史; 原田太一; 松田崇志; 渡边百合香; 石田佳保里
Original assignee: Shiseido Co Ltd
Current assignee: Shiseido Co Ltd
Priority date: 2016-04-28
Filing date: 2017-04-26
Publication date: 2022-08-30
Anticipated expiration: 2037-04-26
Also published as: WO2017188319A1; CN109069357A; HK1258070A1; JP7088830B2; TWI730089B; TW201739442A; KR102415538B1; KR20180135025A; JPWO2017188319A1

Abstract

The present invention aims to provide an oil-in-water emulsion cosmetic in which a powder is mixed into an internal oil phase, which has unprecedented characteristics such as improved water resistance and ultraviolet protection effect by contact with water, sweat, or the like, which are improved as compared with those immediately after application, and which is also excellent in feeling of use and cleansing properties. The present invention relates to an oil-in-water type emulsion cosmetic characterized by containing: (A) the ultraviolet absorbent, (B) the oil phase thickening agent, (C) the hydrophobized powder, (D) the nonionic surfactant and/or the core-crown microgel, and (E) the non-volatile oil component (including the ultraviolet absorbent (A)), wherein the ratio ([ (B) + (C) ]/(E)) of the total amount of the oil phase thickening agent (B) and the hydrophobized powder to the amount of the non-volatile liquid oil component (E) is 0.2 to 20.

Description

Oil-in-water type emulsion cosmetic

Technical Field

The present invention relates to an oil-in-water type emulsion cosmetic. More specifically, the present invention relates to an oil-in-water emulsion cosmetic composition containing a powder in an internal aqueous phase, which has excellent water resistance and has characteristics such that the ultraviolet protection effect is improved by contact with water, sweat, or the like, compared with those of the conventional emulsion cosmetic composition immediately after application.

Background

Protection of the skin from ultraviolet rays is one of important issues in skin care and body care, and various UV (ultraviolet) protective cosmetics have been developed in order to minimize adverse effects of ultraviolet rays on the skin. In 1 Sunscreen cosmetic (sun screen cosmetic) as a UV-screening cosmetic, UVA and UVB are blocked from reaching the skin by blending an ultraviolet absorber or an ultraviolet scattering agent, and the skin is protected from ultraviolet rays (non-patent document 1). Recently, it is considered important to protect the skin from ultraviolet rays in daily life as well as under severe ultraviolet ray conditions in outdoor activities such as swimming pools in summer, swimming in the sea, and skiing in winter, and it is expected that general skin care cosmetics have an ultraviolet ray protection effect.

As a formulation of a sunscreen cosmetic, a formulation in an emulsified form is frequently used, and the ultraviolet protection ability may be lowered due to instability of emulsification. Patent document 1 describes that the storage stability is improved and the deterioration of the ultraviolet protection ability due to long-term storage is suppressed by blending a free fatty acid having 14 to 24 carbon atoms. However, even if the ultraviolet protection ability is maintained until just before use, if the sunscreen cosmetic applied to the skin comes into contact with water or sweat, the ultraviolet absorber or the ultraviolet scattering agent is lost from the applied cosmetic, and it is considered that the ultraviolet protection effect is inevitably lowered.

Oil-in-water emulsions are also widely used as sunscreen cosmetics because they provide a feeling of use that they are water-wet. However, oil-in-water emulsion cosmetics are often inferior to water-in-oil emulsion cosmetics in water resistance, and the ultraviolet protection ability is more likely to be deteriorated due to the loss of the ultraviolet absorber or the ultraviolet scattering agent. Further, it is known that an oil-in-water type emulsion cosmetic containing a powder such as an ultraviolet scattering agent blended with an internal oil is particularly poor in water resistance, and if the amount of the powder blended is increased in order to obtain a high ultraviolet protection ability, it is necessary to blend an excessive amount of the oil component as a dispersion medium, and as a result, there is also a problem that a sticky feeling of use is given.

An attempt has also been made to improve water resistance by blending a film forming agent in an oil-in-water emulsion cosmetic (patent document 2). However, since cosmetics applied to the skin are exposed to various moisture from the inside and outside of the coating film, such as moisture from the external environment, such as sweat or seawater secreted from the skin, it is difficult to completely prevent the loss of the ultraviolet absorber or ultraviolet scattering agent even if a resin or coating agent for imparting water resistance is blended at a high level. In addition, even when the loss of the ultraviolet absorber or the like can be completely prevented, it is considered that the ultraviolet protection effect obtained does not exceed that immediately after application.

Documents of the prior art

Patent document

Patent document 1; japanese patent laid-open publication No. 2015-30723

Patent document 2; japanese laid-open patent publication No. 2004-91377

Non-patent document

Non-patent document 1; "New cosmetics science" 2 nd edition, Wufu edition of light well, 2001, published in Nanshan Tang, 497-504 th page

Disclosure of Invention

Problems to be solved by the invention

The present invention is based on the finding that, in the course of research for developing an oil-in-water emulsion sunscreen cosmetic having an efficient ultraviolet protection effect, the effect is improved on the contrary without lowering the ultraviolet protection effect by contact with water, sweat, or the like. The oil-in-water emulsion cosmetic composition of the present invention has novel and innovative properties that have not been achieved before, such as an improved ultraviolet protection effect when exposed to moisture.

Means for solving the problems

The present inventors have made extensive studies to solve the above problems, and as a result, have found that: the present inventors have found that an oil-in-water type emulsion cosmetic containing a powder as an internal oil phase contains an oil-phase thickener, and the ratio of the total amount of the oil-phase thickener and the hydrophobized powder to the amount of the nonvolatile oil component is adjusted to fall within a specific range, whereby the water resistance and stability are improved and the above-described novel innovative characteristics are exhibited, and thus the present invention has been completed.

Namely, the present invention provides an oil-in-water type emulsion cosmetic characterized by containing:

(A) an ultraviolet absorber;

(B) an oil phase thickener;

(C) hydrophobicizing the powder;

(D) nonionic surfactants and/or microgels of Core-Corona (Core-Corona) type; and

(E) a nonvolatile liquid oil component (containing the ultraviolet absorber (a); and is

(E) The ratio ([ (B) + (C) ]/(E)) of the total amount of the oil phase thickener (B) and the hydrophobized powder (C) to the amount of the nonvolatile liquid oil component is 0.2 to 20.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention, with the above-described configuration, has an ultraviolet protection effect after contact with water, sweat, or the like, which is significantly improved as compared to that immediately after application of a cosmetic to the skin. That is, the oil-in-water type emulsion cosmetic of the present invention is an innovative sunscreen cosmetic having a property that is directly opposite to the conventional common knowledge, such as an ultraviolet ray protection effect, and the like, is improved by contact with moisture and the like, which causes deterioration of the effect, as compared with the conventional oil-in-water type emulsion cosmetic. Further, the cosmetic coating film is made uniform by contact with water, and therefore the optical properties of the skin to which the cosmetic is applied become close to the original color, and the cosmetic effect of increasing the transparency and making the skin feel beautiful is also exhibited.

Further, the oil-in-water type emulsion cosmetic of the present invention is excellent in stability, and the water resistance of a cosmetic coating film is improved even if a coating agent or the like is not incorporated at a high level. Therefore, the coating feeling is not generated, the spreadability in use (application) is good, and the coating can be easily removed by using a general-purpose detergent or soap. That is, the present invention can provide an oil-in-water type emulsion cosmetic excellent in usability and washability in addition to a special ultraviolet ray protection effect and a beauty effect.

Detailed Description

As described above, the oil-in-water emulsion cosmetic of the present invention contains (a) an ultraviolet absorber, (B) an oil phase thickener, (C) a hydrophobized powder, (D) a nonionic surfactant and/or a core-crown microgel, and (E) a nonvolatile liquid oil component. The following describes an oil-in-water emulsion sunscreen cosmetic as one embodiment of the present invention.

(A) Ultraviolet absorber

The ultraviolet absorber (a) (hereinafter, sometimes simply referred to as "component a") to be incorporated in the oil-in-water type emulsion cosmetic of the present invention may be at least one selected from ultraviolet absorbers conventionally incorporated in sunscreen cosmetics.

The ultraviolet absorber (component a) used in the present invention is not particularly limited, and specific examples thereof include: organic ultraviolet absorbers such as 2-ethylhexyl p-methoxycinnamate, 2, 4-bis- { [4- (2-ethylhexyloxy) -2-hydroxy ] -phenyl } -6- (4-methoxyphenyl) 1,3, 5-triazine, -crilin, dimethylpolysiloxane diethylbenzylidene malonate, poly-Si-15, t-butylmethoxydibenzoylmethane, ethylhexyl triazone, diethylaminohydroxybenzoyl hexyl benzoate, bisethylhexyloxyphenol methoxyphenyl triazine, oxybenzone-3, methylenebisbenzotriazolyl tetramethylbutyl phenol, phenylbenzimidazole sulfonic acid, homosalate, and ethylhexyl salicylate.

When the amount of the ultraviolet absorber (component a) in the oil-in-water type emulsion cosmetic of the present invention is 1% by mass or more, preferably 1 to 40% by mass, and more preferably 2 to 30% by mass, based on the total amount of the cosmetic, in the case of a sunscreen cosmetic. On the other hand, the ultraviolet absorber (component a) in the present invention may constitute a part (or all) of the nonvolatile liquid oil component (component E). For example, when a sufficient ultraviolet protection ability can be ensured by the ultraviolet scattering agent stably maintained in the inner oil phase by blending a nonvolatile liquid oil component other than the ultraviolet absorber, the blending amount of the ultraviolet absorber may be set to less than 6 mass%, for example, 5 mass% or less, 3 mass% or less, or 2 mass% or less.

(B) Oil phase thickener

(B) The oil phase thickener (hereinafter, sometimes simply referred to as "component B") is a substance capable of adjusting the viscosity of the oil phase, and is preferably a dextrin fatty acid ester, a sucrose fatty acid ester, a solid or semisolid hydrocarbon oil, an organically modified clay mineral, a fatty acid or a salt thereof, or the like, and particularly preferably contains two or more kinds selected from these.

The dextrin fatty acid ester is an ester of dextrin or reduced dextrin with a higher fatty acid, and can be used without particular limitation as long as it is generally used in cosmetics. The dextrin or reduced dextrin preferably has an average degree of polymerization of saccharides of 3 to 100. The constituent fatty acids of the dextrin fatty acid ester are preferably saturated fatty acids having 8 to 22 carbon atoms. Specifically, there may be mentioned: and dextrin palmitate, dextrin oleate, dextrin stearate, dextrin myristate, (palmitic acid/2-ethylhexanoic acid) dextrin, and the like.

The sucrose fatty acid ester is preferably a linear or branched saturated or unsaturated fatty acid having 12 to 22 carbon atoms. Specifically, there may be mentioned: sucrose octanoate, sucrose decanoate, sucrose laurate, sucrose myristate, sucrose palmitate, sucrose stearate, sucrose oleate, sucrose erucate, and the like.

The solid or semisolid hydrocarbon oil is a hydrocarbon that is solid or semisolid at normal temperature (25 ℃), and specific examples thereof include: petrolatum, hydrogenated palm oil, hydrogenated castor oil (castor wax), hydrogenated palm kernel oil, hydrogenated castor oil, hydrogenated peanut (groundnut) oil, hydrogenated rapeseed oil, hydrogenated camellia oil, hydrogenated soybean oil, hydrogenated olive oil, hydrogenated macadamia nut oil, hydrogenated sunflower seed oil, hydrogenated wheat germ oil, hydrogenated rice bran oil, hydrogenated cottonseed oil, hydrogenated avocado oil, waxes, and the like.

The organically modified clay mineral is one of colloidal hydrous aluminum silicates having a three-layer structure, and is typically a clay mineral represented by the following general formula (1) modified with a quaternary ammonium salt cationic surfactant.

(X,Y) _2-3 (Si,Al) ₄ O ₁₀ (OH) ₂ Z _1/3 ·nH ₂ O (1)

(wherein, X ═ Al, Fe (III), Mn (III), Cr (III), Y ═ Mg, Fe (II), Ni, Zn, Li, Z ═ K, Na, Ca)

Specific examples thereof include: dimethyl distearyl ammonium lithium bentonite (distearyl dimethylamine lithium bentonite), dimethyl alkylammonium lithium bentonite, benzyl dimethyl stearyl ammonium lithium bentonite, distearyl dimethyl ammonium chloride-treated magnesium aluminum silicate, etc. Preferred commercially available products include Bentone27 (Benzyldimethylstearylammonium chloride-treated lithium bentonite, manufactured by Elementis Japan) and Bentone38 (distearyldimethylammonium chloride-treated lithium bentonite, manufactured by Elementis Japan).

Examples of the fatty acid include myristic acid, palmitic acid, stearic acid, and behenic acid, which are solid at room temperature. Examples of the salt of the fatty acid include calcium salts, magnesium salts, and aluminum salts of these fatty acids.

(C) Hydrophobicizing powder

The powder (hereinafter, also simply referred to as "component C") in the present invention is a powder blended as an ultraviolet scattering agent, a use powder, and a coloring material in conventional sunscreen cosmetics and the like, and includes a powder subjected to surface hydrophobization. The ultraviolet scattering agent is not particularly limited, and is preferably a fine particulate metal oxide, and examples thereof include powders of zinc oxide, titanium oxide, iron oxide, cerium oxide, tungsten oxide, and the like. Examples of the usable powder and coloring material include talc and mica titanium.

Examples of the surface-hydrophobizing agent that can be used in general cosmetic field include silicones such as dimethylpolysiloxane and alkyl-modified silicone, alkoxysilanes such as octyltriethoxysilane, dextrin fatty acid esters such as dextrin palmitate, fatty acids such as stearic acid, and silica. Among these, alkoxysilanes such as octyltriethoxysilane, and ultraviolet scattering agents subjected to surface hydrophobization with silica are particularly preferable.

(D) Nonionic surfactant and/or core-crown microgel

(D1) Nonionic surfactant

The nonionic surfactant (hereinafter, sometimes referred to as "component D1") in the present invention may be 1 or 2 or more nonionic surfactants selected from among nonionic surfactants conventionally used in oil-in-water emulsion cosmetics, and among them, those having an HLB (hydrophilic-to-oil ratio) of 6 or more are preferably used.

The nonionic surfactant used in the present invention particularly preferably contains polyoxyethylene hydrogenated castor oil in terms of stability of the formulation and an effect of increasing absorbance by contact with moisture. Specific examples of the polyoxyethylene hydrogenated castor oil include PEG-10 hydrogenated castor oil, PEG-20 hydrogenated castor oil, PEG-25 hydrogenated castor oil, PEG-30 hydrogenated castor oil, PEG-40 hydrogenated castor oil, PEG-50 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-80 hydrogenated castor oil, and PEG-100 hydrogenated castor oil. On the other hand, when the polyoxyethylene-free hydrogenated castor oil is not contained, it is preferable to use a nonionic surfactant having an HLB of 8 or more, preferably 10 or more, and more preferably 12 or more.

The amount of the (D1) nonionic surfactant to be blended in the present invention is 0.1 to 10% by mass, preferably 0.5 to 5% by mass, and more preferably 0.8 to 3% by mass, based on the total amount of the cosmetic. If the amount of the component D1 is less than 0.1% by mass, it may be difficult to obtain sufficient stability, and if it exceeds 10% by mass, the composition may be inferior in terms of usability. The polyoxyethylene hydrogenated castor oil is preferably blended in an amount of 50% by mass or more of the component D1, and the component D1 preferably contains the polyoxyethylene hydrogenated castor oil.

(D2) Core-crown type microgel

The core-corona microgel (hereinafter, sometimes referred to as "component D2") in the present invention is a gel microparticle in which a hydrophilic group (corona) is partially provided on the surface of a hydrophobic core. As the core-crown type microgel in the present invention, either a crosslinked type or a non-crosslinked type can be used.

As particularly suitable core-crown type microgel, as shown below, there can be exemplified (acrylate/methoxy methacrylate PGE) crosslinked polymer [ crosslinked core-crown type microgel ] and acrylamide core-crown type microgel [ non-crosslinked core-crown type microgel ].

1. Cross-linked core-crown microgel [ (acrylic ester/methoxy methacrylate PGE-90) cross-linked polymer) ]

The crosslinked core-crown microgel of this embodiment can be obtained by radical polymerizing monomers represented by the following formulae (1) to (3) under specific conditions.

R ₁ Is an alkyl group having 1 to 3 carbon atoms, and n is a number of 8 to 200. X is H or CH ₃ 。

As the polyethylene oxide macromonomer represented by the above formula (1), commercially available products such as those sold by Aldrich or Blemmer (registered trademark) sold by Nikkiso Co can be used. The molecular weight of the polyethylene oxide moiety (i.e., the value of n) must be 8 to 200.

Examples of such macromonomers include Blemmer (registered trademark) PME-400, Blemmer (registered trademark) PME-1000, and Blemmer (registered trademark) PME-4000 manufactured by Nikkiso Co.

R ₂ Is an alkyl group having 1 to 3 carbon atoms.

R ₃ Is an alkyl group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms.

As the hydrophobic monomer represented by the formula (2), commercially available products sold by Aldrich or Tokyo chemical company can be used, for example.

Specific examples of the hydrophobic monomer of formula (2) include: methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, decyl acrylate, dodecyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, and the like. In particular, methyl methacrylate, butyl methacrylate and octyl methacrylate are preferably used.

These hydrophobic monomers are general-purpose raw materials and are also easily available as general industrial raw materials.

R ₄ And R ₅ Each independently represents an alkyl group having 1 to 3 carbon atoms, and m is a number of 0 to 2.

The crosslinkable monomer represented by the formula (3) can be obtained as a commercially available product or an industrial raw material. The crosslinkable monomer is preferably hydrophobic.

The value of m is preferably 0 to 2. Specifically, ethylene glycol dimethacrylate (hereinafter, sometimes abbreviated as egdma (ethylene glycol dimethacrylate)) available from Aldrich, or Blemmer (registered trademark) PDE-50 available from solar oil, or the like is preferably used.

The crosslinked core-crown microgel of this embodiment is obtained by radical-polymerizing the above-mentioned monomers under the following conditions (a1) to (e 1).

(a1) The molar ratio of the molar amount of polyethylene oxide macromonomer added/the molar amount of the hydrophobic monomer added is 1: 10-1: 250.

(b1) the amount of the crosslinkable monomer added is 0.1 to 1.5% by mass relative to the amount of the hydrophobic monomer added.

(c1) The hydrophobic monomer represented by the formula (2) is composed of 1 or more than 2 mixed monomers of methacrylic acid derivatives with C1-C8 alkyl.

(d1) The polymerization solvent is a mixed solvent of water and an organic solvent, and when a polyhydric alcohol is used as the organic solvent, the organic solvent is 1 or 2 or more selected from dipropylene glycol, 1, 3-butanediol, and isoprene glycol.

(e1) The solvent composition of the mixed solvent of water and organic solvent is calculated by the mass ratio or the volume ratio of 20 ℃, and the ratio of water: and (3) organic solvent (90-10): 10 to 90.

In the present invention, "the amount of the crosslinkable monomer added to the amount of the hydrophobic monomer added" is defined as "crosslinking density (% by mass)". The crosslinking density of the core-cap microgel used in the present invention is determined by the condition of (b1), and the amount of the crosslinkable monomer added is required to be 0.1 to 1.5 mass% relative to the amount of the hydrophobic monomer added. Each condition is described in further detail below.

Condition (a1)

The molar amount of polyethylene oxide macromonomer added to the hydrophobic monomer is in the range of polyethylene oxide macromonomer: hydrophobic monomer ═ 1: 10-1: and in the range of 250 (molar ratio). The above-mentioned addition molar amount is preferably 1: 10-1: 200, more preferably 1: 25-1: 100.

if the molar amount of the hydrophobic monomer is less than 10 times the molar amount of the polyethylene oxide macromonomer, the polymerized polymer becomes water-soluble without forming a core-crown type microgel. When the molar amount of the hydrophobic monomer exceeds 250 times the molar amount of the polyethylene oxide macromonomer, the dispersion stability of the polyethylene oxide macromonomer is insufficient, and the hydrophobic polymer obtained from the insoluble hydrophobic monomer aggregates or precipitates.

Condition (b1)

By copolymerizing the crosslinkable monomer, the microgel in which the hydrophobic polymer of the core portion is crosslinked can be polymerized.

If the amount of the crosslinkable monomer added is less than 0.1 mass% of the amount of the hydrophobic monomer added, the crosslinking density becomes low and the microgel dissolves when swollen. When the amount of addition exceeds 1.5 mass%, the microgel particles aggregate with each other, and thus, microgel particles having a narrow particle size distribution cannot be suitably polymerized. The amount of the crosslinkable monomer added is preferably 0.2 to 1.0% by mass, more preferably 0.2 to 0.8% by mass, and most preferably 0.2 to 0.5% by mass.

Condition (c1)

The hydrophobic monomer represented by formula (2) is required to be composed of 1 or more than 2 mixed monomers of methacrylic acid derivatives having alkyl groups with 1 to 8 carbon atoms. If the number of carbon atoms is 0 (monomer having no terminal ester bond), the monomer may become excessively hydrophilic, and emulsion polymerization may not be smoothly performed. On the other hand, if the carbon number is 9 or more, steric hindrance may occur during polymerization, and the crosslinked structure may not be successfully formed.

Condition (d1)

The polymerization solvent must be a mixed solvent of water and an organic solvent. As the organic solvent, ethanol, propanol, butanol, polyhydric alcohol, or the like can be used, and in the case of using a polyhydric alcohol, it is preferable to be one in which the hydrophobic monomer represented by formula (2) and the crosslinkable monomer represented by formula (3) can be dissolved. The polyhydric alcohol used in the present invention is necessarily dipropylene glycol, 1, 3-butanediol, or isoprene glycol.

In the case where the polymerization solution is used as a starting material without purification steps such as dialysis, which is industrially producible, the solvent to be mixed with water is not ethanol, propanol or butanol, which is an organic solvent that may cause irritation when applied to the skin, but is preferably a polyol that can be blended in cosmetics in a versatile manner.

Condition (e1)

The solvent composition of the mixed solvent of water and an organic solvent as a polymerization solvent must be such that, in a mass ratio of 20 ℃, water: and (3) organic solvent (90-10): 10 to 90. The solvent composition of the water-organic solvent mixed solvent is preferably water: and (3) organic solvent (90-10): 10 to 90(20 ℃ volume ratio), more preferably water: 80-20% of organic solvent: 20 to 80(20 ℃ volume ratio).

The polymerization solvent is necessary to add an organic solvent in order to uniformly dissolve the hydrophobic monomer. The mixing ratio of the organic solvent is 10 to 90 by volume. When the mixing ratio of the organic solvent is less than 10% by volume, the hydrophobic monomer has extremely low dissolving ability, and the polymerization proceeds in the form of monomer droplets to form a large mass, so that no microgel is produced. When the mixing ratio of the organic solvent exceeds 90% by volume, an emulsion of the hydrophobic monomer obtained by hydrophobic interaction is not formed, and emulsion polymerization is not performed, so that a microgel cannot be obtained.

The core-crown microgel obtained by using the polyhydric alcohol as the organic solvent is a water-polyhydric alcohol mixed solvent as the polymerization solvent, does not contain ethanol, and can simply obtain the cosmetic which has no skin irritation to users with sensitive skin.

As the polymerization initiator used in the polymerization system, a commercially available polymerization initiator generally used for water-soluble thermal radical polymerization can be used. In this polymerization system, polymerization can be carried out without particularly strictly controlling the stirring conditions, and the particle size distribution of the polymerized microgel particles can be obtained to be very narrow.

2. Non-crosslinked core-crown microgel [ acrylamide core-crown ]

The non-crosslinked core-crown microgel preferably used in the present invention is a dispersion of core-crown fine particles obtained by radical polymerizing monomers represented by the following formulae (4) to (6) under specific conditions.

R ₁ Is an alkyl group having 1 to 3 carbon atoms, and n (the molecular weight of the polyethylene oxide moiety) is a number of 8 to 200. X is H or CH ₃ 。

The polyethylene oxide macromonomer represented by the formula (4) is preferably an acrylic acid derivative or a methacrylic acid derivative. For example, commercially available products such as those sold by Aldrich, and Blemmer (registered trademark) sold by Nichigan oil Co., Ltd. As examples, PME-400, PME-1000, and PME-4000 (n-9, n-23, and n-90 in formula (1), respectively, all manufactured by japan oil co., ltd.) as methoxypolyethylene glycol monomethacrylate may be used.

R ₂ Represents an alkyl group having 1 to 3 carbon atoms, R ₃ Represents a substituent containing an alkyl group having 1 to 12 carbon atoms.

The hydrophobic monomer represented by the above formula (5) is preferably an acrylic acid derivative or a methacrylic acid derivative (also referred to as "acrylate derivative monomer"), and examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, decyl acrylate, dodecyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, decyl methacrylate, and dodecyl methacrylate. Among them, methyl methacrylate (also known as methyl methacrylate), butyl methacrylate (also known as butyl methacrylate), and octyl methacrylate are particularly preferable.

These hydrophobic monomers are general-purpose raw materials and can be easily obtained as general industrial raw materials. For example, commercially available products sold by Aldrich or Tokyo chemical company can be used.

R ₄ H or C1-3 alkyl, R ₅ And R ₆ Represents H or a substituent containing an alkyl group having 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms.

The hydrophobic monomer represented by the above formula (6) is preferably an acrylamide derivative or a methacrylamide derivative (also referred to as "acrylamide derivative monomer"). For example, t-butylacrylamide, N-dimethylacrylamide, N- [3- (dimethylamino) propyl ] acrylamide, t-butylmethacrylamide, octylacrylamide, octylmethacrylamide, octadecylacrylamide and the like can be preferably used. Among these, tert-butylacrylamide, N-dimethylacrylamide and N- [3- (dimethylamino) propyl ] acrylamide are particularly preferable.

These hydrophobic monomers are available as commercially available products or industrial raw materials.

The copolymer constituting the core-crown type fine particles of the present invention is obtained by copolymerizing the macromonomer represented by the above formula (4) and 1 or 2 or more hydrophobic monomers selected from the group represented by the above formulae (5) and (6) by an arbitrary radical polymerization method under the following conditions (a2) to (d 2).

(a2) The molar ratio expressed by the molar amount of the polyethylene oxide macromonomer added/(the molar amount of the acrylate derivative monomer and/or the acrylamide derivative monomer added) is 1: 10-1: 250.

(b2) the macromonomer represented by the formula (4) is an acrylic acid derivative or a methacrylic acid derivative having a polyethylene glycol group having a repeating unit of 8 to 200,

the acrylate derivative monomer represented by the formula (5) is an acrylic acid derivative or a methacrylic acid derivative having a substituent containing an alkyl group having 1 to 12 carbon atoms,

the acrylamide derivative monomer represented by the formula (6) is an acrylamide derivative or a methacrylamide derivative having a substituent containing an alkyl group having 1 to 12 carbon atoms,

(c2) the polymerization solvent is water-alcohol mixed solvent, and the alcohol is 1 or more than 2 selected from ethanol, dipropylene glycol, 1, 3-butanediol, and isoprene glycol.

(d2) The solvent composition of the water-alcohol mixed solvent is that the mass ratio of water at 20 ℃ is as follows: 90-10% of alcohol: 10 to 90.

Each condition is described in further detail below.

Condition (a2)

The above polyethylene oxide macromonomer, and the above hydrophobic monomer (i.e., the sum of the acrylate derivative monomer and/or the acrylamide derivative monomer) are added in molar amounts based on the polyethylene oxide macromonomer: hydrophobic monomer ═ 1: 10-1: and in the range of 250 (molar ratio). The above-mentioned addition molar amount is preferably 1: 10-1: 200, more preferably 1: 25-1: 100.

if the molar amount of the hydrophobic monomer is less than 10 times the molar amount of the polyethylene oxide macromonomer, the polymerized polymer becomes water-soluble, and does not form core-crown type particles. When the molar amount of the hydrophobic monomer exceeds 250 times the molar amount of the polyethylene oxide macromonomer, the dispersion of the polyethylene oxide macromonomer is insufficiently stabilized, and the hydrophobic polymer obtained from the insoluble hydrophobic monomer aggregates and precipitates.

Condition (b2)

The condition (b2) includes 3 conditions (b2-1) to (b2-3) below.

(b2-1)

The macromonomer represented by the formula (4) is an acrylic acid derivative or a methacrylic acid derivative having a polyethylene glycol group having a repeating unit of 8 to 200. When the repeating unit is 7 or less, particles stably dispersed in a solvent may not be obtained, and when the repeating unit exceeds 200, the particles may be made fine and become unstable when blended in a cosmetic.

(b2-2)

The acrylate derivative monomer represented by the formula (5) is an acrylic acid derivative or a methacrylic acid derivative having a substituent containing an alkyl group having 1 to 12 carbon atoms. If the number of carbon atoms is 0 (monomer having no terminal ester bond), the monomer may be too hydrophilic to be smoothly emulsion polymerized. On the other hand, if the carbon number is 13 or more, a preferable feeling of use may not be obtained.

(b2-3)

The acrylamide derivative monomer represented by the formula (6) is an acrylamide derivative or a methacrylamide derivative having a substituent comprising an alkyl group having 1 to 18 carbon atoms.

The hydrophobic monomer of this embodiment is required to be a mixture of 1 or 2 or more monomers selected from the group consisting of the acrylate derivative monomer represented by the above formula (5) and the acrylamide derivative monomer represented by the above formula (6).

In this embodiment, two kinds of methacrylate and butyl methacrylate or four kinds of methacrylate, t-butylacrylamide, N-dimethylacrylamide and N- [3- (dimethylamino) propyl ] acrylamide are particularly preferably used as the hydrophobic monomer. In the combination of these hydrophobic monomers, it is preferable to use methoxypolyethylene glycol monomethacrylate as the macromonomer.

Without being limited thereto, the most preferable combination of the macromonomer and the hydrophobic monomer in this embodiment is:

methoxypolyethylene glycol monomethacrylate, methacrylate, butyl methacrylate, and the like having 8 to 90, most preferably 15 repeating units of polyethylene glycol group,

Methoxy polyethylene glycol monomethacrylate, methacrylate, t-butyl acrylamide, N-dimethylacrylamide, and N- [3- (dimethylamino) propyl ] acrylamide, t-butyl methacrylamide, octyl acrylamide, octyl methacrylamide, and octadecyl acrylamide, in which the repeating unit of the polyethylene glycol group is 8 to 200, most preferably 90.

Condition (c2)

The polymerization solvent must be a water-alcohol mixed solvent. The alcohol is preferably one which can dissolve the hydrophobic monomers represented by the formulae (5) and (6). Therefore, 1 or 2 or more selected from ethanol, dipropylene glycol, 1, 3-butanediol, and isoprene glycol are preferable.

Condition (d2)

The solvent composition of the water-alcohol mixed solvent as the polymerization solvent is preferably water: and (2) alcohol is 90-10: 10-90, more preferably water: 80-20% of alcohol: 20 to 80 parts. When the mixing ratio of the alcohol is less than 10% by volume, the dissolving ability of the hydrophobic monomer may be extremely low, and fine particles may not be formed. When the mixing ratio of the alcohol exceeds 90% by volume, an emulsion of hydrophobic monomers obtained by hydrophobic interaction may not be formed, and the emulsion polymerization may not be performed, so that fine particles may not be obtained.

The core-crown type microgel preferably used in the present invention is a microgel stabilized by a polyethylene oxide chain, which is a nonionic polymer, and is expected to have acid resistance or alkali resistance with respect to dispersion stability in water. The microgel is considered to be a core-crown type polymer microgel in which a hydrophilic macromonomer and a hydrophobic monomer are ordered in a solvent to form a substantially constant particle diameter and a core portion is crosslinked or uncrosslinked.

The amount of the core-crown microgel to be blended in the cosmetic of the present invention is preferably 0.01 to 10 mass% (purity) based on the total amount of the cosmetic. When the blending amount is less than 0.01% by mass (purity), it may be difficult to obtain a stable cosmetic. If the amount exceeds 10 mass% (purity), the stability during long-term storage under high temperature conditions may be poor, or the feeling of use may be poor.

The core-crown type microgel is an oil-in-water emulsified composition having a structure in which an oil phase component and an aqueous phase component are emulsified, and a core-crown type microgel emulsifier is adsorbed onto oil droplets of the oil phase component dispersed in the aqueous phase component. The core-crown type microgel emulsifier described above is an oil-in-water type emulsified composition having excellent emulsifying power and extremely excellent stability when used as an emulsifier. In addition, the core-crown microgel can obtain sufficient strength for the behavior of the hydrophobic powder with higher specific gravity existing in the oil phase.

(E) Non-volatile liquid oil component

The oil-in-water type emulsion cosmetic of the present invention contains (E) a nonvolatile liquid oil component.

The term "non-volatile liquid oil" as used herein means a liquid oil at normal temperature (25 ℃) or normal pressure (1 atm (9.8X 10) ⁴ Pa)) is not volatile (e.g., contains an oil component having a boiling point of about 200 ℃ or higher at normal pressure), has fluidity at normal temperature and normal pressure, is a non-solid liquid oil component, and contains a silicone oil and a non-volatile oil other than a silicone oil (e.g., a hydrocarbon oil, an ester oil, etc.).

The nonvolatile liquid oil component (E) in the present invention also contains an oily uv absorber corresponding to the component a. Therefore, the present invention includes (1) a mode in which the nonvolatile liquid oil component (component E) contains a nonvolatile liquid oil component other than the ultraviolet absorber, and (2) a mode in which the component E contains only the ultraviolet absorber.

The nonvolatile liquid oil component other than the ultraviolet absorber contained in the component E includes, for example, hydrocarbon oil, vegetable oil, ester oil, high molecular weight polyoxyalkylene glycol, and silicone oil.

Specific examples thereof include: liquid oils and fats such as palm oil, linseed oil, camellia oil, macadamia nut oil, corn oil, olive oil, avocado oil, camellia oil, castor oil, safflower oil, almond oil, cinnamon oil, jojoba oil, grape oil, almond oil, rapeseed oil, sesame oil, sunflower oil, wheat germ oil, rice bran oil, cottonseed oil, soybean oil, peanut oil, tea oil, evening primrose oil, egg yolk oil, liver oil, triglycerin, tricaprylin, and triisopalmitic acid glyceride; octanoates such as cetyl octanoate, isooctanoates such as glycerol tri-2-ethylhexanoate and neopentyl tetra-2-ethylhexanoate, laurates such as hexyl laurate, myristates such as isopropyl myristate and octyl myristate, palmitates such as octyl palmitate, stearates such as isocetyl stearate, isostearates such as isopropyl isostearate, isopalmitate such as octyl isopalmitate, oleates such as isodecyl oleate, adipates such as diisopropyl adipate, sebacates such as diethyl sebacate, and ester oils such as diisostearyl malate; hydrocarbon oils such as liquid paraffin and squalane; silicone oils such as polyoxybutylene polyoxypropylene glycol and polydimethylsiloxane.

[ Total amount of component B and component C ]/[ amount of component E ] ratio

The cosmetic of the present invention is an oil-in-water type emulsion cosmetic containing a powder in an inner oil phase. In such a powder-in-water emulsion, if the viscosity of the inner oil phase is high, it tends to be difficult to obtain a stable emulsion. However, in the present invention, by setting the ratio ([ B + C/E ]) of the total amount of the oil phase thickener (B) and the hydrophobized powder (C) constituting the internal oil phase to the amount of the nonvolatile liquid oil component (including the ultraviolet absorber (a)) within a specific range, a stable emulsion can be produced, and a special effect of improving the ultraviolet protection ability by contact with moisture can be exhibited.

The ratio ([ B + C/E ]) of the total amount of the oil phase thickener (B) and the hydrophobized powder (C) to the amount of the nonvolatile liquid oil component (E) including the ultraviolet absorber (A) in the oil-in-water type emulsion cosmetic of the present invention is required to be in the range of 0.2 to 20.

The total amount of the oil phase thickener (B) and the hydrophobized powder (C) is preferably 7.5 to 40 mass% based on the total amount of the cosmetic composition, and the amount of the nonvolatile liquid oil component (E) can be appropriately adjusted within a range satisfying the condition that [ B + C/E ] is 0.2 to 20.

The oil-in-water type emulsion cosmetic of the present invention may contain, as optional components, components generally used in cosmetics, in addition to the essential components described above, within a range not to impair the effects of the present invention.

Examples of the optional component include a volatile oil component, and the volatile oil component in the present invention may include a volatile hydrocarbon oil and a lower alcohol such as a volatile silicone oil or ethanol.

The volatile hydrocarbon oil is not particularly limited as long as it is a hydrocarbon oil that is volatile at room temperature (25 ℃) and has been conventionally used in cosmetics and the like. Specific examples thereof include isododecane, isohexadecane, and hydrogenated polyisobutene.

The volatile silicone oil includes silicone oils that are volatile at room temperature (25 ℃) and have been conventionally used in cosmetics and the like, and examples thereof include volatile linear silicone oils (volatile dimethylpolysiloxane) and volatile cyclic silicone oils (volatile cyclomethicone). As the volatile dimethylpolysiloxane, a low viscosity dimethylpolysiloxane such as decamethyltetrasiloxane can be used, and as commercially available products, KF-96L-1.5cs, KF-96L-2cs (both manufactured by shin-Etsu chemical industries, Ltd.) and the like can be cited. Examples of the volatile cyclic polysiloxane include decamethylcyclopentasiloxane (D5).

As other optional components, water-soluble or oil-soluble coating agents can be cited. By blending the coating agent, the resistance to the loss of (a) the ultraviolet absorber or (C) the hydrophobized powder or the abrasion and dropping due to clothes and the like can be further improved. However, the amount of the surfactant is preferably within a range in which the coating feeling (usability) and the cleaning performance are not lowered.

The coating agent is not particularly limited as long as it is generally used for cosmetics, and specifically, includes: PVP-based coating agents such as polyvinylpyrrolidone (PVP), PVP/dimethylaminoethyl methacrylic acid copolymer, PVP/eicosene copolymer, PVP/ethyl methacrylate/methacrylic acid copolymer, PVP/hexadecene copolymer, PVP/VA copolymer, PVP/vinyl acetate/itaconic acid copolymer, and styrene/PVP copolymer; ethyl acrylate/acrylamide/acrylic acid copolymer, ethyl acrylate/butyl acrylate copolymer, ethyl acrylate/ethyl methacrylate copolymer, ethyl acrylate/methacrylic acid copolymer, ethyl acrylate/methyl methacrylate copolymer, octyl acrylate/vinyl acetate copolymer, octyl acrylate/styrene copolymer, butyl acrylate/vinyl acetate copolymer, acrylic coating agents such as butyl acrylate/hydroxy ethyl methacrylate copolymer, butyl acrylate/methyl methacrylate copolymer, methoxyethyl acrylate/hydroxy ethyl acrylate/butyl acrylate copolymer, lauryl acrylate/vinyl acetate copolymer, polyethyl acrylate, polybutyl acrylate, polystyrene acrylic resin; vinyl acetate coating agents such as polyvinyl acetate; methacrylic coating agents such as polymethyl methacrylate, methyl methacrylate/butyl acrylate/caprylic acid acrylate, and diethyl vinylpyrrolidone sulfate/N, N' -dimethylamino methacrylic acid copolymer; vinyl methyl ether-based coating agents such as vinyl methyl ether/ethyl maleate copolymers and vinyl methyl ether/butyl maleate copolymers; styrene-based coating agents such as styrene/methylstyrene/indene copolymers; alkyd resin-based coating agents such as cyclohexane-based alkyd resins; silicone resin coating agents such as trimethylsiloxy silicic acid.

Examples of the other optional components include components generally used in cosmetics, such as whitening agents, moisturizers, antioxidants, oily active agents, surfactants, aqueous phase thickeners, usability powders (excluding those subjected to hydrophobic treatment), colorants, and aqueous active agents.

As the powder and coloring material for optional use, pigments, pearlescent pigments and the like can be used, and they are usually blended in cosmetic preparations. Specifically, there may be mentioned: inorganic white pigments (titanium dioxide, zinc oxide), inorganic red pigments (iron oxide (red iron oxide), iron titanate), inorganic brown pigments (B-iron oxide), inorganic yellow pigments (yellow iron oxide, yellow earth pigments), inorganic black pigments (black iron oxide, carbon, titanium suboxide), inorganic violet pigments (manganese violet, cobalt violet), inorganic green pigments (chromium oxide, chromium hydroxide, cobalt titanate), inorganic blue pigments (ultramarine blue, Prussian blue), pearl pigments (titanium oxide-coated mica, titanium oxide-coated bismuth oxychloride, titanium oxide-coated talc, colored titanium oxide-coated mica, bismuth oxychloride, fish scales), metal powder pigments (aluminum powder, copper powder), organic pigments (red 202, red 205, red 220, red 228, red 405, orange 203, orange 204, yellow 205, red 228, red 405, orange 203, orange 204, yellow 205, red 405, etc.), metal powder pigments (aluminum powder, copper powder, calcium oxide, calcium, Yellow No. 401 and blue No. 404), organic pigments of zirconium, barium, aluminum lake (red No. 3, red No. 104, red No. 227, red No. 401, orange No. 205, yellow No. 4, yellow No. 202, green No. 3, blue No. 1), natural pigments (chlorophyll, carotenoid (C-carotene), carthamin, cochineal, chalcone, lutein, betanin, flavonol, flavone, anthocyanin, anthraquinone, naphthoquinone), functional pigments (boron nitride, photochromic pigment, synthetic fluorophlogopite, iron-containing synthetic fluorophlogopite, fine particle composite powder (mixed fine powder)), and the like, but are not limited thereto. The powder and the coloring material may be used, for example, by combining 1 or 2 or more selected from the above.

The oil-in-water type emulsion cosmetic of the present invention can be produced according to a conventional method. For example, it can be prepared by the following method: the aqueous phase thickener is optionally dissolved in an aqueous component (containing a nonionic surfactant and/or a core-crown microgel), a surfactant is added to a part of an oily component in which the oil phase thickener is dissolved, the ultraviolet scattering agent is dissolved or dispersed, the resultant is added to the aqueous component, emulsification treatment is performed using a homomixer or the like, and finally the remaining oily component and powder are added and mixed under stirring (optionally, a shearing force is added during stirring).

The oil-in-water type emulsion cosmetic of the present invention can be preferably used, for example, as sunscreen cream, sunscreen lotion, pack for imparting sunscreen effect, foundation, and the like.

The embodiment of the sunscreen cosmetic composition has been described above, but the present invention is not limited to this embodiment. For example, by using the cosmetic of the present invention as a base and blending a pearling agent, a coloring agent (pigment), and the like, a novel cosmetic or a skin care cosmetic can be produced which changes in the characteristics (transparency, color developability, irregularity correcting effect, and the like) upon contact with moisture. The cosmetic of this type has a new characteristic that the cosmetic effect or skin care effect is improved by the contact with sweat or moisture. This characteristic was observed in both sunscreen cosmetics containing 1% by mass or more of the ultraviolet absorber (a), cosmetics containing less than 1% by mass of the ultraviolet absorber (a), and cosmetics containing no ultraviolet absorber (see table 4 and formulation examples 5 and 6).

That is, the present invention also includes an aspect of the oil-in-water type emulsion cosmetic characterized in that:

contains (A1) an ultraviolet absorber in an amount of 1% by mass or less,

(B) an oil-phase thickening agent, wherein,

(C) the hydrophobicizing treatment of the powder is carried out,

(D) nonionic surfactant and/or core-crown microgel, and

(B) The ratio ([ (B) + (C) ]/(E)) of the total amount of the oil phase thickener and the hydrophobized powder (C) to the amount of the nonvolatile liquid oil component (E) is 0.2-20.

The components (A) to (E) in the invention of this embodiment are the same as those described for the sunscreen cosmetic. The amount of the ultraviolet absorber (a) added is less than 1% by mass, and may be, for example, 0.5% by mass or less, 0.3% by mass or less, or 0.1% by mass or less, and the ultraviolet absorber may not be contained.

The oil-in-water type emulsion cosmetic of the present invention is characterized in that the thickness of the cosmetic coating film (film thickness) is made uniform by contact with moisture. The present inventors believe, without limiting the scope of the present invention, that the distribution (density) of the ultraviolet absorber in the direction perpendicular to the skin of the cosmetic coating film on the skin is made uniform over the entire coating film, and as a result, the ultraviolet protection ability is improved. This phenomenon is not limited to the ultraviolet absorber, and is considered to contribute to uniformity of distribution of each component to be blended. Therefore, when the film is made uniform by contact with moisture such as perspiration, the optical properties (diffuse reflection light and internal reflection light) of the cosmetic coating film become close to plain color, and the effect of increasing the transparency and feeling beautiful is exhibited.

Examples

The present invention will be described in more detail below by referring to specific examples, but the present invention is not limited to the examples below. The amount to be blended in the following examples and the like represents% by mass unless otherwise specified.

An oil-in-water type emulsified sunscreen cosmetic composition having the composition described in the following table 1 to table 4 was prepared according to the method described in paragraph 0078. For each sample, the emulsion stability and the change in absorbance before and after the water bath were measured.

Determination of emulsion stability

The samples of each example were stored at 60 ℃ for two weeks, and the presence or absence of separation or precipitation was visually observed. The measurement results were evaluated by the following criteria.

A: no separation and precipitation was observed and the stability was high.

B: separation or precipitation was observed.

Measurement of ultraviolet ray protective Effect

On an S plate (5X 5cm V-grooved PMMA plate, SPFMASTER-PA01) at 2mg/cm ² The samples of each example were dropped, applied with fingers for 60 seconds, dried for 15 minutes, and then measured for absorbance (500 to 280nm) using a U-3500 model self-recording spectrophotometer manufactured by Hitachi, Ltd. Absorbance (Abs) was calculated by the following formula using an uncoated plate as a control.

Abs＝-log(T/To)

T: transmittance of sample, To: transmittance when uncoated

The measured plate was sufficiently immersed in water having a hardness of 50 to 500, and directly stirred in the water (using a 3-1 motor, 300rpm) for 30 minutes. Thereafter, the surface was dried for about 15 to 30 minutes until no water droplets were formed on the surface, the absorbance was measured again, and the Abs change rate (the following formula) was calculated from the Abs integrated values before and after the water bath as the ultraviolet ray protection ability improving effect.

The absorbance change rate (%) before and after the water bath (absorbance integrated value after water bath)/(absorbance integrated value before water bath) × 100

In the present invention, when the absorbance change rate exceeds 100 (%), it is defined that the ultraviolet ray protection effect is improved.

[ Table 1]

From the results shown in table 1, examples 1 to 4 containing an oil phase thickener ((palmitic acid/2-ethylhexanoic acid dextrin, hydrogenated palm oil, or vaseline)) exhibited the characteristic effect that the change in absorbance before and after the water bath exceeded 100% and the ultraviolet protection effect was improved, and comparative example 1 containing no oil phase thickener and comparative example 2 containing a silicone coating agent instead of the oil phase thickener did not exhibit the same effect.

[ Table 2]

From the results shown in Table 2, it was confirmed that examples 5 to 10 in which the ratio [ (B + C)/E ] of the total amount of the oil phase thickener (B) and the hydrophobized powder (C) to the amount of the nonvolatile liquid oil component (E) was in the range of 0.2 to 20 gave stable samples, and the ultraviolet protection effect was improved by the change rate of absorbance before and after the water bath exceeding 100%. However, comparative example 3 in which the ratio [ (B + C)/E ] exceeded 20 did not obtain a stable emulsion, and also failed to measure the absorbance.

[ Table 3]

According to the results shown in tables 1 to 3, when polyoxyethylene hydrogenated castor oil was used as the nonionic surfactant, a stable emulsion having HLB of 14 (tables 1 and 2) or 9 (table 3) was obtained, and the rate of change in absorbance before and after water bath was also more than 100%, and further, the water resistance was also excellent. On the other hand, although the system containing no polyoxyethylene hydrogenated castor oil has HLB of 7 and is emulsifiable, the rate of change in absorbance before and after water bath is not 100% (comparative example 4), and a stable emulsion cannot be prepared in the system using a nonionic surfactant having HLB of 5.5 (comparative example 5).

On the other hand, examples 12 to 15 using a crosslinked core-crown microgel ((acrylate/methoxy methacrylate PEG-90) crosslinked polymer) or a non-crosslinked core-crown microgel (acrylamide-based crown) instead of or in addition to the nonionic surfactant are excellent in emulsion stability, and the change rate of absorbance before and after water bath is more than 100%, and further, water resistance is excellent.

[ Table 4]

From the results shown in table 4, it was confirmed that the effects of the present invention can be obtained even when the surface treatment agent of the hydrophobized powder is changed to silicone (dimethylpolysiloxane), a dextrin fatty acid ester such as alkoxysilane (octyltriethoxysilane), and palmityl dextrin, a fatty acid such as stearic acid, and silica.

A water-in-oil emulsion cosmetic was prepared according to the formulation shown in table 5 below in the same manner as in the other examples. For each sample, a sweat (water bath) test was performed on 10 functional inspectors under the following conditions.

After the application of the samples of each example, the skin was evaluated for transparency and beauty (presence or absence of solid feeling) compared to the skin before the sweating (water bath) test, after the lapse of 60 minutes in an environment at an air temperature of 30 ℃ and a humidity of 80%.

The results of the sweating (water bath) test were rated according to the following criteria.

A: more than 8 of 10 patients have true feeling

B: the 10 patients have a feeling of reality of 5 to 7

C: less than 4 of 10 have true feeling

[ Table 5]

As shown in table 5, in examples 22 to 24 satisfying the requirements of the present invention, the skin made up was more transparent and beautiful after sweating and contact with moisture. However, comparative examples 6 and 7, which did not contain (B) an oil-soluble thickener, did not achieve such a feeling.

Other formulation examples of the oil-in-water emulsion cosmetic of the present invention are shown below. The cosmetics of these formulation examples are also excellent in emulsion stability and water resistance, and in the case of sunscreen cosmetics, the change rate of absorbance before and after a water bath exceeds 100%, and a beautiful effect such as a beautiful appearance by a water bath is obtained.

Formulation example 1 sunscreen emulsion

[ Table 6]

Formulation example 2 sunscreen cream

[ Table 7]

Formulation example 3 Foundation

[ Table 8]

Purified water	Remains of
		Citric acid sodium salt	Proper amount of
Citric acid	Proper amount of
		Edetic acid trisodium	Proper amount of
PEG-40 hydrogenated Castor oil (HLB: 12)	1.5
		Dioleic acid PEG-8 (HLB: 5)	0.2
1, 3-butanediol	5
		Glycerol	5
Dimethylacrylamide/acryloyl sodium dimethyltaurate cross-linked polymer	1
		Succinoglycans	0.3
Sorbitan sesquiisostearate	0.3
		Light isoparaffins	12
Isostearic acid	1
		4-tert-butyl-4' -methoxydibenzoylmethane	1
2,4, 6-tris [4- (2-ethylhexyloxycarbonyl) phenylamino]1,3, 5-triazines	2
		2, 4-bis- [ {4- (2-ethylhexyloxy) -2-hydroxy } -phenyl]-6- (4-methoxyphenyl) -1,3, 5-triazine	1
Diethylamino hydroxybenzoyl hexyl benzoate	2
		Palmitic acid dextrin	3
Sucrose fatty acid ester	3
		Octyltriethoxysilane distearyldimethylammonium chloride treated Zinc oxide	10
Pearling agent (mica titanium)	3
		Titanium oxide (pigment)	1
Iron oxide	0.3
		In total	100
B+C	16
		(B+C)/E	2.286

Formulation example 4 Foundation make-up liquid

[ Table 9]

Ion exchange water	Remainder of
		Citric acid sodium salt	Proper amount of
Citric acid (food)	Proper amount of
		EDTA-3Na.2H2O	Proper amount of
PEG-60 hydrogenated Castor oil (HLB: 14)	2
		1, 3-butanediol	7
Glycerol	3
		Dimethylacrylamide/sodium acryloyldimethyl taurate crosslinked polymer	0.3
Succinoglycans	0.2
		Sodium carboxymethylcellulose	0.1
Light isoparaffins	18
		Sorbitan sesquiisostearate	0.2
Isostearic acid SX	1
		2-ethylhexyl p-methoxycinnamate	5
2, 4-bis- [ {4- (2-ethylhexyloxy) -2-hydroxy } -phenyl]-6- (4-methoxyphenyl) -1,3, 5-triazine	2
		Mineral oil	2
Polypropylene glycol	1
		Methyl polysiloxane	4
Palmitic acid dextrin	3
		Vaseline	3
Dimethylpolysiloxane-treated silica-coated zinc oxide	16
		Phenoxyethanol	Proper amount of
Titanium oxide (pigment)	5
		Pearling agent (mica titanium)	3
Iron oxide	1
		Hexamethylene diisocyanate/trimethylol hexyl lactone cross-linked polymer	1
In total	100
		B+C	22
(B+C)/E	1.47

Formulation example 5 CC cream

[ Table 10]

Purified water	Remainder of
		Citric acid sodium salt	Proper amount of
Citric acid	Proper amount of
		Edetic acid trisodium salt	Proper amount of
PEG-40 hydrogenated Castor oil (HLB: 12)	1.5
		Diisostearic acid PEG-8 (HLB: 5)	0.2
1, 3-butanediol	3
		Glycerol	8
Dimethylacrylamide/sodium acryloyldimethyl taurate crosslinked polymer	1
		Succinoglycans	0.3
Sorbitan sesquiisostearate	0.3
		Light isoparaffins	12
Isostearic acid	1
		Palmitic acid dextrin	2
Sucrose fatty acid ester	1
		Calcium stearate treated talc	5
Pearling agent (mica titanium)	3
		Titanium oxide (pigment)	0.5
Iron oxide	0.3
		In total	100
B+C	8
		(B+C)/E	8

Formulation example 6 Foundation make-up liquid

[ Table 11]

Ion exchange water	Remainder of
		Citric acid sodium salt	Proper amount of
Citric acid (food)	Proper amount of
		EDTA-3Na.2H2O	Proper amount of
PEG-60 hydrogenated Castor oil (HLB: 14)	2
		1, 3-butanediol	7
Glycerol	3
		Dimethylacrylamide/sodium acryloyldimethyl taurate crosslinked polymer	0.3
Succinoglycans	0.2
		Sodium carboxymethylcellulose	0.1
Light isoparaffins	18
		Sorbitan sesquiisostearate	0.2
Isostearic acid SX	1
		Sebacic acid isobutyl ester	5
Mineral oil	2
		Polypropylene glycol	1
Methyl polysiloxane	4
		Palmitic acid dextrin	3
Vaseline	3
		Phenoxyethanol	Proper amount of
Titanium oxide (pigment)	5
		Pearling agent (mica titanium)	3
Iron oxide	1
		Hexamethylene diisocyanate/trimethylol hexyl lactone cross-linked polymer	1
Total of	100
		B+C	6
(B+C)/E	0.75

Claims

1. An oil-in-water type emulsion cosmetic characterized by comprising:

(A) an ultraviolet absorber containing an oily ultraviolet absorber;

(B) an oil phase thickener;

(C) hydrophobicizing the powder;

(D) (D1) a nonionic surfactant; and

(E) a nonvolatile liquid oil component containing the oily ultraviolet absorber; and is

The (D1) nonionic surfactant comprises at least 1 selected from the group consisting of PEG-20 hydrogenated castor oil, PEG-25 hydrogenated castor oil, PEG-30 hydrogenated castor oil, PEG-40 hydrogenated castor oil, PEG-50 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-80 hydrogenated castor oil and PEG-100 hydrogenated castor oil,

(B) the ratio ([ (B) + (C) ]/(E)) of the total amount of the oil phase thickener and the hydrophobized powder (C) to the amount of the nonvolatile liquid oil component (E) is 0.2 to 20.

2. The cosmetic according to claim 1, further comprising (D2) a core-crown microgel.

3. The cosmetic according to claim 1 or 2, wherein (B) the oil phase thickener is 1 or 2 or more selected from the group consisting of dextrin fatty acid ester, sucrose fatty acid ester, organically modified clay mineral, and solid or semi-solid hydrocarbon oil.

4. The cosmetic according to claim 1 or 2, wherein the hydrophobized powder (C) is a powder surface-treated with 1 or 2 or more kinds selected from the group consisting of alkoxysilane, dextrin fatty acid ester, fatty acid, and silica.

5. The cosmetic according to claim 1 or 2, wherein the amount of the (a) ultraviolet absorber is 1% by mass or more.

6. The cosmetic according to claim 3, wherein the amount of the ultraviolet absorber (A) is 1% by mass or more.

7. The cosmetic according to claim 4, wherein the amount of the ultraviolet absorber (A) is 1% by mass or more.

8. The cosmetic according to claim 1 or 2, wherein the total amount of the oil phase thickener (B) and the hydrophobized powder (C) is 7.5 to 40% by mass.

9. The cosmetic according to claim 3, wherein the total amount of the oil phase thickener (B) and the hydrophobized powder (C) is 7.5 to 40% by mass.

10. The cosmetic according to claim 4, wherein the total amount of the oil phase thickener (B) and the hydrophobized powder (C) is 7.5 to 40% by mass.

11. The cosmetic according to claim 5, wherein the total amount of the oil phase thickener (B) and the hydrophobized powder (C) is 7.5 to 40% by mass.

12. The cosmetic according to claim 6, wherein the total amount of the oil phase thickener (B) and the hydrophobized powder (C) is 7.5 to 40% by mass.

13. The cosmetic according to claim 7, wherein the total amount of the oil phase thickener (B) and the hydrophobized powder (C) is 7.5 to 40% by mass.