TWI689316B - Oil-in-water emulsion cosmetics - Google Patents

Abstract

The object of the present invention is to provide an oil-in-water emulsified cosmetic, which is highly formulated with an ultraviolet absorber and an ultraviolet scattering agent in the oil phase to achieve a high SPF (Sun Protection Factor) and has unique characteristics when applied to the skin Delicate touch.

The water-in-oil emulsified cosmetic of the present invention is characterized in that it contains (A) 0.05 to 1% by mass of hydrophobically modified alkyl cellulose, (B) 5 to 40% by mass of oil, and (C) 2.5 to 30 by mass % Of the ultraviolet scattering agent with a hydrophobic surface, and (D) an aqueous phase tackifier with low salt resistance, and the above (C) ultraviolet scattering agent is dispersed in the oil phase.

Description

Oil-in-water emulsion cosmetics

The present invention relates to an oil-in-water emulsified cosmetic, which contains an ultraviolet absorber and an ultraviolet scattering agent, has a high ultraviolet defense capacity (SPF) and has a unique and delicate touch, and the present invention particularly relates to a sunscreen cosmetic .

The oil-in-water emulsified cosmetics are widely used as a base that imparts a refreshing feel to the water-in-oil type. However, if powder is blended into its internal phase (oil phase), especially the hydrophobized powder, the emulsification system tends to become unstable.

As one method of stabilizing the emulsification system, an attempt was made to thicken the outer phase (aqueous phase) of the oil-based emulsifying base in water with a water-soluble thickener. However, by dissolving the ions of the hydrophobized powder self-adjusted in the internal phase (oil phase), the viscosity of the water phase decreases, and the occurrence of destabilization or viscosity is considered a problem (Patent Document 1). Patent Document 1 discloses a case of preventing elution by firmly covering the surface of an inorganic powder.

As another stabilization method, a method of using a low-viscosity oil (dispersion medium) or dispersant that promotes the dispersion of powder is also proposed. For example, in Patent Document 2, by using a volatile oil component, a liquid higher fatty acid (dispersion medium), and a silicone or sugar ester (dispersant) having a carboxyl group in the structure, a hydrophobization-treated ultraviolet scattering agent ( (Zinc oxide) Stably formulated as an oil phase.

However, as a dispersion medium prepared for powder dispersion, (volatile) non-polar oils such as low-viscosity hydrocarbon oils or silicone oils are generally used. It is known that if polar oils are used in the internal phase, the hydrophilic group of the surfactant The distribution of the oil phase increases, and emulsification becomes difficult.

In other words, in order to achieve a high ultraviolet defense capability, it is necessary to formulate a highly polar ultraviolet absorber and a polar oil as a solvent if necessary. On the other hand, in order to emulsify the oil phase containing the ultraviolet scattering agent stably, it must be formulated as The non-polar oil of the dispersion medium, it is extremely difficult to control the total amount of oil while maintaining a high UV protection.

For example, Patent Document 3 describes that in a system in which a highly polar ultraviolet absorber, a non-polar silicone oil, and an ultraviolet scattering agent (powder) coexist, 2-ethylhexanoic acid 2-ethylhexyl ester and/or Isononyl 2-ethylhexanoate serves as an emulsifier, thereby obtaining a stable emulsion. In addition, Patent Document 4 describes an oil-in-water emulsified cosmetic in which a hydrophobically-modified alkyl cellulose is used as an emulsifier and a hydrophobized powder is stably blended in an oil phase. However, regarding these cosmetics, since the non-polar oil accounts for more than half of the oil phase (internal phase), there is a limit to the suppression of the total amount of oil.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2012-251152

[Patent Document 2] Japanese Patent Laid-Open No. 2012-111726

[Patent Document 3] Japanese Patent Laid-Open No. 2007-145722

[Patent Document 4] Japanese Patent Laid-Open No. 2013-199453

As mentioned above, the previous oil-in-water emulsified sunscreen cosmetics have the following problems: in order to stably formulate UV absorbers and UV-scattering agents to achieve high SPF, the amount of oil must be increased, and as a result, the oil-in-water emulsion is lost The unique and delicate sense of use, on the contrary, if you pay attention to the sense of use and suppress the amount of oil, the ultraviolet protection ability obtained is limited.

Therefore, the object of the present invention is to provide an oil-in-water emulsified cosmetic which, when applied to the skin, has a unique and delicate feeling of use that disintegrates like a melt, and is UV-resistant The ability to defend is also excellent.

In order to solve the above problems, the present inventors have made intensive studies and found that by using a hydrophobically modified cellulose derivative of a specific structure as an emulsifier, the oil phase (internal phase) contains a UV absorber and a hydrophobic treatment The ultraviolet scattering agent, and the addition of a tackifier with lower salt resistance in the water phase (outer phase), can achieve a higher SPF while maintaining a unique and delicate touch, thus completing the present invention.

That is, the present invention provides an oil-in-water emulsified cosmetic, characterized in that it contains (A) 0.05 to 1% by mass of hydrophobically modified alkyl cellulose, (B) 5 to 40% by mass of oil, and (C) 2.5~30% by mass of ultraviolet scattering agent with hydrophobic surface, and (D) water phase tackifier with low salt resistance, and the above (C) ultraviolet scattering agent is dispersed in the oil phase.

Regarding the oil-in-water emulsified cosmetics of the present invention, by using a hydrophobically modified alkyl cellulose as an emulsifier, a thickener is formulated in the aqueous phase, the total amount of oil can be suppressed, and ultraviolet absorbers and ultraviolet scattering agents are highly formulated. Achieve a higher SPF. Furthermore, in the present invention, by blending a viscosity-increasing agent with a low salt tolerance which was previously avoided due to the bad influence on the emulsion stability, in the aqueous phase, it can be given a uniqueness like melting when applied to the skin Excellent use feeling of delicate touch.

The so-called "unique and delicate touch" in this manual means that when applying cosmetics to the skin with fingers or the like, the viscosity drops sharply, and the touch is like a disintegration. At the same time, it gives the skin a very stretch Delicate touch.

Hereinafter, the present invention will be described in detail.

The oil-in-water emulsified cosmetics of the present invention (hereinafter, also simply referred to as "emulsified cosmetics") contain (A) a hydrophobically modified alkyl cellulose, (B) an oil component, (C) an ultraviolet scattering agent having a hydrophobic surface, And (D) Aqueous tackifier with lower salt resistance is an essential ingredient.

The (A) hydrophobically modified alkyl cellulose used in the present invention means an alkyl cellulose which is hydrophobically modified by an alkyl group having 14 to 22 carbon atoms. This hydrophobically modified alkyl cellulose is a compound obtained by introducing a long-chain alkyl group as a hydrophobic group into a water-soluble cellulose ether derivative, and is represented by the following general formula (I).

[In the formula, R may be the same or different, and is selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a group -[CH ₂ CH(CH ₃ )O] _m -H (where m is 1 ~5, preferably an integer from 1 to 3), radical -CH ₂ CH ₂ OH, and radical -CH ₂ CH(OH)CH ₂ OR' (where R'is an alkane with 14 to 22 carbon atoms) More than one kind of radicals, it is assumed that they must contain the radical -CH ₂ CH(OH)CH ₂ OR'; and, A is radical -(CH ₂ ) _q -(q is an integer of 1~3, preferably 1), n is 100~10000, preferably an integer of 500~5000]

Regarding the method for producing the hydrophobically modified alkyl cellulose of the above formula (I), the water-soluble cellulose ether derivative used as a base can be roughly described, and specifically, for methyl cellulose (R is a hydrogen atom or a methyl group) , Ethyl cellulose (R is a hydrogen atom or ethyl), propyl cellulose (R is a hydrogen atom or propyl), butyl cellulose (R is a hydrogen atom or butyl), hydroxypropyl cellulose [R Is a hydrogen atom or a hydroxypropyl group (yl-[CH ₂ CH(CH ₃ )O] _m -H (where m is 1 to 5, preferably an integer of 1 to 3))], hydroxypropylmethyl Cellulose (R is a hydrogen atom, methyl group or hydroxypropyl group (same as above)), etc., a compound for introducing a long-chain alkyl group having 14 to 22 carbon atoms, specifically, a long-chain alkyl group of the following formula (II) Glycerol ether is obtained by contact in the presence of an alkaline catalyst.

[R' is an alkyl group having 14 to 22 carbon atoms]

The content of the group -CH ₂ CH(OH)CH ₂ OR' introduced into the hydrophobically modified alkyl cellulose of the present invention is preferably about 0.1 to 5.0% by mass relative to the entire hydrophobically modified alkyl cellulose. In order to set such a content ratio, it is sufficient to select and manufacture the molar ratio, reaction time, type of alkali catalyst, etc. when the above-mentioned water-soluble cellulose ester derivative and long-chain alkyl glycidyl ether are reacted. After the above reaction, purification steps such as neutralization, filtration, washing, drying, and screening of the reactants may also be performed.

Furthermore, among the above water-soluble cellulose ether derivatives, it is particularly preferable to select hydroxypropylmethyl cellulose (whereby R in formula (I) becomes a hydrogen atom, a methyl group, and a group -[CH ₂ CH( CH ₃ )O] _m H, and any one of the four groups -CH ₂ CH(OH)CH ₂ OR', the q of group A is 1, and the group A is methylene).

Furthermore, R′ in the long-chain alkyl glycidyl ether of formula (II) is an alkyl group having a carbon number of 14 to 22, preferably an alkyl group having a carbon number of 14 to 20, and further preferably a stearin having a carbon number of 18 Radical (-C ₁₈ H ₃₇ ). If the carbon number of the alkyl group R'is less than 14 or 23 or more, the emulsion stability due to the hydrophobically modified alkyl cellulose obtained is insufficient.

The weight average molecular weight of the hydrophobically modified alkyl cellulose is preferably 100,000 to 1000,000, more preferably 300,000 to 800,000, and further preferably 550,000 to 750,000.

In the present invention, stearoxyhydroxypropyl cellulose is preferably used as the hydrophobically modified alkyl cellulose, and commercially available products can also be used. For example, SANGELOSE 90L (show Name: Hydrophobized hydroxypropyl methylcellulose, manufactured by Datong Chemical Industry Co., Ltd.), Natrosol Plus 330cs (manufactured by Ashland), Polysurf 67cs (manufactured by Ashland), etc.

The blending amount of the hydrophobically modified alkyl cellulose (A) in the emulsified cosmetic of the present invention is 0.05 to 1% by mass, preferably 0.1 to 0.5% by mass, and more preferably 0.1 to 0.3% by mass. If it is less than 0.05% by mass, sufficient emulsion stability cannot be obtained, and even if it exceeds 1% by mass for blending, it is difficult to obtain a further increase in the effect.

The oil component (B) in the emulsified cosmetics of the present invention can be selected from one or more types of oily components commonly used in cosmetics and the like.

The blending amount of the (B) oil component relative to the emulsified cosmetic is 5 to 40% by mass, preferably 10 to 40% by mass, and more preferably 20 to 35% by mass.

Regarding the emulsified cosmetic of the present invention, by setting the above-mentioned oil component (B) at 55 mass% or more, preferably 60 mass% or more, more preferably 70 mass% or more, and still more preferably 80 wt% or more as a polar oil, Can further improve the emulsion stability. The upper limit of the ratio of polar oil to oil content is not particularly limited, for example, polar oil can account for more than 90%, or 100% of oil content can be polar oil.

The "polar oil" in this specification is not particularly limited as long as it has a higher polarity among oils generally used in cosmetics. For example, it is preferable to use a relative dielectric constant of about 5 or more, preferably About 10 or more oil.

Representative examples of polar oils in the emulsified cosmetics of the present invention include ester oils and ultraviolet absorbers. In addition, by containing more polar oil than previous emulsified cosmetics, it is also possible to stably prepare, for example, highly polar perfumes.

Specific examples of ester oils suitable for the emulsified cosmetics of the present invention include tripropylene glycol dipivalate, isononyl isononanoate, isopropyl myristate, cetyl caprylate, octyl dodecane myristate Ester, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyl decanoate dimethyl caprylate, cetyl lactate, myristyl lactate Myristate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesterol 12-hydroxystearate, cetyl ethylhexanoate, ethyl di-2-ethylhexanoate Diol, dipentaerythritol fatty acid ester, monoisostearic acid N-alkyl glycol, dicaprylic acid neopentyl glycol, diisostearyl malate, di-2-heptyl undecanoic acid glyceride, Tri-2-ethylhexanoic acid trimethylolpropane, triisostearic acid trimethylolpropane, tetra-2-ethylhexanoic acid pentaerythritol ester, triisooctanoic acid glyceride (tri-2-ethylhexyl Glyceride), trioctanoic acid glyceride, triisopalmitic acid glyceryl ester, triisostearic acid trimethylolpropane, 2-ethylhexanoic acid cetyl ester, 2-ethylhexyl palmitate, three nutmeg Glyceryl acid ester, tri-2-heptyl undecanoic acid glyceryl ester, castor oil fatty acid methyl ester, oleic acid oleic acid ester, glyceryl glyceryl ester, palmitic acid 2-heptyl undecyl ester, adipic acid diiso Butyl ester, N-lauroyl-L-glutamic acid-2-octyl dodecyl ester, di-2-heptyl undecyl adipate, ethyl laurate, sebacic acid di-2 -Ethylhexyl ester, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, lemon Acid triethyl ester, etc.

衍生物、苯基苯并三唑衍生物、蒽基衍生物、咪唑啉衍生物、亞苄基丙二酸酯衍生物、4,4-二芳基丁二烯衍生物等。以下列舉具體例及商品名等，但並不受該等之限定。 As the ultraviolet absorber, a highly polar oily ultraviolet absorber commonly used in cosmetics can be exemplified, and is not particularly limited. For example, there can be exemplified: benzoic acid derivatives, salicylic acid derivatives, cinnamic acid derivatives, benzophenone derivatives, β,β-diphenyl acrylate derivatives, benzophenone derivatives, benzylidene Camphor derivatives, phenylbenzimidazole derivatives, three

Derivatives, phenylbenzotriazole derivatives, anthracenyl derivatives, imidazoline derivatives, benzylidene malonate derivatives, 4,4-diaryl butadiene derivatives, etc. Specific examples and trade names are listed below, but they are not limited to these.

Examples of benzoic acid derivatives include p-aminobenzoic acid (PABA) ethyl ester, ethyl-dihydroxypropyl PABA, ethylhexyl-dimethyl PABA (for example, "ESCALOL 507", ISP), and glycerol PABA , PEG-25-PABA (for example "UVINUL P25", BASF Corporation), diethylaminohydroxybenzoyl benzoate hexyl ester (for example "UVINUL A plus"), etc.

Examples of salicylic acid derivatives include humaloxate ("Eusolex HMS", Rona/EM Industries), and ethylhexyl salicylate (e.g. "Neo Heliopan OS", Haarmann & Reimer Company), dipropylene glycol salicylate (e.g. "Dipsal", Scher Company), TEA salicylate (e.g. "Neo Heliopan TS", Haarmann & Reimer Company), etc.

啉酸酯、DEA甲氧基肉桂酸酯、甲基肉桂酸二異丙酯、乙基己酸甘油酯-二甲氧基肉桂酸酯、二-(2-乙基己基)-4'-甲氧基亞苄基丙二酸酯等。 Examples of cinnamic acid derivatives include octylmethoxycinnamate or ethylhexyl methoxycinnamate (for example, "Parsol MCX", Hoffmann-La Roche), isopropyl methoxycinnamate, Isoamyl methoxycinnamate (eg "Neo Heliopan E1000", Haarmann & Reimer),

Phosphonoate, DEA methoxycinnamate, diisopropyl methylcinnamate, glyceryl ethylhexanoate-dimethoxycinnamate, di-(2-ethylhexyl)-4'-methyl Oxybenzylidene malonate etc.

As the dibenzoylmethane derivative, 4-tributyl-4'-methoxydibenzoylmethane (for example, "Parsol 1789") and the like can be exemplified.

As β,β-diphenyl acrylate derivatives, octocrylene (for example, "UVINUL N539", BASF Corporation) and the like can be exemplified.

Examples of benzophenone derivatives include benzophenone-1 (for example, "UVINUL 400", BASF Corporation), benzophenone-2 (for example, "UVINUL D50", BASF Corporation), and benzophenone- 3 or oxybenzone (eg "UVINUL M40", BASF), benzophenone-4 (eg "UVINUL MS40"; BASF), benzophenone-5, benzophenone-6 (eg "Helisorb 11", Norquay), benzophenone-8 (eg "Spectra-Sorb UV-24", American Cyanamid), benzophenone-9 (eg "UVINUL DS-49", BASF), diphenyl Methone-12 etc.

Examples of benzylidene camphor derivatives include 3-benzylidene camphor (for example, "Mexoryl SD", Chimex Corporation), 4-methylbenzylidene camphor, and benzylidene camphorsulfonic acid (for example, "Mexoryl SL", Chimex), camphor benzalkonium methylsulfate (e.g. "Mexoryl SO", Chimex), p-xylylene dicamphor sulfonic acid (e.g. "Mexoryl SX", Chimex), polyacrylamide methylmethylene Benzyl camphor (for example, "Mexoryl SW", Chimex Corporation), etc.

As the phenylbenzimidazole derivative, there can be exemplified: phenylbenzimidazole sulfonic acid (for example, "Usolex 232", Merck), disodium phenyldibenzimidazole tetrasulfonate (for example, "Neo Heliopan AP", Haarmann & Reimer) etc.

衍生物，可例示：苯甲醚三

(例如「Tinosorb S」，Ciba Specialty Chemicals公司)、乙基己基三

酮(例如「UVINUL T150」，BASF公司)、二乙基己基丁醯胺基三

酮(例如「Uvasorb HEB」，Sigma 3V公司)、2,4,6-三(二異丁基-4'-胺基亞苄基丙二酸酯)-均三

等。 As three

Derivatives, exemplified: anisole three

(Eg "Tinosorb S", Ciba Specialty Chemicals), ethylhexyl tri

Ketone (for example, "UVINUL T150", BASF), diethylhexylbutyramide tris

Ketone (for example, "Uvasorb HEB", Sigma 3V), 2,4,6-tris(diisobutyl-4'-aminobenzylidenemalonate)-all three

Wait.

Examples of phenylbenzotriazole derivatives include cresol-triazole trisiloxane (for example, "Silatrizole", Rhodia Chimie), and methylenebis (benzotriazolyltetramethylbutylphenol) ( For example, "Tinosorb M" (Ciba Specialty Chemicals)).

酯(例如「Neo Heliopan MA」，Haarmann & Reimer公司)等。 As an anthracenyl derivative, anthracenic acid can be exemplified

Ester (for example, "Neo Heliopan MA", Haarmann & Reimer), etc.

Examples of imidazoline derivatives include ethylhexyldimethoxybenzylidene dioxaimidazoline propionate and the like.

Examples of the benzylidene malonate derivatives include polyorganosiloxanes having a benzylidene malonate functional group (for example, polysilicone-15, "Parsol SLX", DSM Nutrition Japan) and the like.

As the 4,4-diaryl butadiene derivative, 1,1-dicarboxy(2,2′-dimethylpropyl)-4,4-diphenylbutadiene and the like can be exemplified.

Regarding other oils that can be formulated together with the above-mentioned polar oils (hereinafter also referred to as "non-polar oils"), it can be set as a low-polarity oil that is usually formulated in cosmetics, for example, selected from its relative dielectric constant About one-fifth or more than five kinds of oil.

The blending amount of the ultraviolet absorber contained in the polar oil is, for example, preferably 40% by mass or more of the polar oil, preferably 50% by mass or more, and more preferably 60% by mass or more.

The blending amount of ultraviolet absorber relative to the emulsified cosmetics is 5~25 quality The amount is preferably 8 to 23% by mass, more preferably 10 to 20% by mass.

The non-polar oil formulated in the emulsified cosmetic of the present invention is not particularly limited, and is preferably selected from volatile or non-volatile silicone oil and hydrocarbon oil.

Specific examples include chain silicone oils such as polydimethylsiloxane, tolylpolysiloxane, and methylhydropolysiloxane, and octylmethylcyclotetrasiloxane and decamethyl Cyclic silicone oils such as cyclopentasiloxane, dodecylcyclohexasiloxane, decane, dodecane, isododecane, isohexadecane, liquid paraffin, squalane, squalene, Paraffin and other hydrocarbon oils.

As the base material of the (C) ultraviolet scattering agent having a hydrophobic surface in the emulsified cosmetic of the present invention, powder of zinc oxide or titanium oxide is preferably used.

The zinc oxide and titanium oxide used in the present invention are not particularly limited, and can be appropriately selected from those commonly used in cosmetics.

The ultraviolet scattering agent (C) used in the present invention is an ultraviolet scattering agent having a hydrophobic surface obtained by hydrophobizing the surface of a substrate such as zinc oxide or titanium oxide.

As a method of surface hydrophobizing treatment, silicone treatment of methylhydropolysiloxane, methylpolysiloxane, etc.; fluorine treatment by perfluoroalkyl phosphate, perfluoroalcohol, etc.; Amino acid treatment such as N-acyl glutamic acid; other lecithin treatment; metal soap treatment; fatty acid treatment; alkyl phosphate treatment, etc.

In the emulsified cosmetic of the present invention (C), the amount of the ultraviolet scattering agent having a hydrophobic surface is 2.5 to 30% by mass, preferably 3 to 30% by mass, and more preferably 4 to 20% by mass. If the blending amount is less than 2.5% by mass, it tends to be difficult to obtain a higher SPF value than before, and the unique delicate touch during coating may not be obtained. On the other hand, if it exceeds 30% by mass, the emulsification stability and usability may decrease.

The (D) low-tolerance water phase tackifier in the present invention is a tackifier having the function of thickening the water phase, and the viscosity is generated by the presence of an electrolyte that is usually formulated in a range of cosmetics reduce. Such a tackifier with low salt resistance is selected from water-soluble tackifiers previously formulated in cosmetics and the like for the purpose of adjusting the viscosity of the water phase.

Specific examples include vinyl polymers such as polyvinyl alcohol, polyvinyl acetate, polyvinyl methyl ether, polyvinyl pyrrolidone, copolymers of vinyl pyrrolidone and vinyl acetate, and carboxyvinyl polymers; polyacrylic acid Sodium, polyethyl acrylate, polyalkanolamine, alkyl methacrylate and dimethylaminoethyl methacrylate copolymer, poly-2-acrylamide-2-methylpropanesulfonic acid, polymethyl Acrylic acid trimethylammonium, (acrylic acid dimethyl taurine ammonium/VP) copolymer, dimethylacrylamide/acrylic acid dimethyl taurine (Na) cross-linked polymer and other acrylic acid Department of polymer.

Among them, among the tackifiers with lower salt resistance (the viscosity is reduced due to the increase in electrolyte concentration), compared with the type of tackifier that is thickened by crosslinking of polymer chains, if it is used in The water-swellable microgels are formed in the water phase, and the type of tackifier which is thickened by friction between the swelling microgel particles further suppresses the slippery feeling when the cosmetics are fused to the skin, which is preferable. The reason is that the hydrophobically modified alkyl cellulose formulated as an emulsifier also has a viscosity-increasing effect through crosslinking of polymer chains, so if a type of viscosity-increasing agent that uses the same mechanism to thicken is further formulated, it will encourage the The thickening effect can be the cause of slippery feeling.

In the emulsified cosmetic of the present invention (D), the formulation amount of the water phase tackifier with low salt resistance is 0.05 to 3% by mass, preferably 0.1 to 2% by mass, and more preferably 0.15 to 1% by mass. If it is less than 0.05% by mass, it cannot function as a thickener (viscosity adjustment and emulsification stabilization), and it cannot obtain a unique and delicate touch during coating. If it exceeds 3% by mass for blending, stickiness or stick slip may occur.

Regarding the emulsified cosmetics of the present invention, in addition to the above-mentioned essential ingredients (A) to (D), various components usually formulated in the cosmetics can be formulated within a range that does not hinder the effects of the present invention. Specific examples include propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, polyethylene glycol and other glycols; glycerin, diethylene glycol Glycerin such as glycerin and polyglycerin; sugar alcohols such as sorbitol, mannitol, maltitol, xylitol, erythritol; sugars such as fructose, glucose, galactose, maltose, lactose, trehalose; chlorophyll, β-carrot Natural pigments such as vegetarian; gum arabic, tragacanth, polygalactose, guar Plant polymers such as gum, locust bean gum, karaya gum, gellan gum, carrageenan, etc.; microbial polymers such as Sanxian gum, dextran, succinoglycan, amylopectin; collagen, casein , Albumin, gelatin and other animal polymers; carboxymethyl starch, methyl hydroxypropyl starch and other starch polymers; methyl cellulose, ethyl cellulose, methyl hydroxypropyl cellulose, hydroxyethyl fiber Cellulose, sodium sulfate, hydroxypropyl cellulose, sodium carboxymethyl cellulose, crystalline cellulose and other cellulose-based polymers; sodium alginate, propylene glycol alginate and other alginic acid-based polymers; other thickeners; Vitamins such as magnesium ascorbyl phosphate, ascorbic acid glucoside, vitamin B6 hydrochloride, panthenol ether; fungicides, anti-inflammatory agents, preservatives, plant extracts, amino acids, cooling agents and other agents; ethanol, isopropyl alcohol and other low-grade Alcohols; aromatic alcohols such as phenoxyethanol and benzyl alcohol; surfactants, etc., but not limited to these.

Regarding the emulsified cosmetics of the present invention, by using a hydrophobically modified alkyl cellulose as an emulsifier, it can be an oil-in-water emulsified composition, and polarized oil containing ultraviolet absorbers and ultraviolet light with a hydrophobic surface can be scattered The agent is blended into the inner phase (oil phase) more than the previous oil-in-water cosmetics to exert excellent UV protection. Furthermore, by setting the ratio of the polar oil, which was previously considered to be a cause of destabilization, to 55 mass% or more of the oil phase, on the contrary, it exhibits a surprising effect of improving the emulsion stability.

On the other hand, it is believed that the hydrophobically modified alkyl cellulose has a moderate emulsifying power, so the ultraviolet scattering agent formulated in the internal phase (oil phase) is likely to interact with the external phase (aqueous phase), especially when applied to the skin. The electrolyte (ultraviolet scattering agent, etc.) coming out of the internal phase comes into contact with the viscosity-increasing agent in the water phase to reduce the viscosity sharply, thereby giving a unique and delicate touch like melting. Therefore, the emulsified cosmetic of the present invention is preferably one that does not substantially contain an emulsifier other than the hydrophobically modified alkyl cellulose, especially an emulsifier having strong emulsifying power. In the case of blending other emulsifiers, the blending amount is preferably 3% by mass or less, or about 1% by mass or less.

The emulsified cosmetics of the present invention can be prepared according to a method commonly used in oil-in-water emulsified cosmetics. That is, the water phase component and the oil phase component can be mixed separately while stirring the water phase The oil phase ingredients are added to the ingredients and emulsified to prepare them.

The emulsified cosmetic of the present invention is not particularly limited, but it is usually preferably an internal phase (oil phase) having an average particle diameter of about 15 μm or less.

[Example]

Hereinafter, specific examples will be given to further illustrate the present invention in detail, but these do not limit the technical scope of the present invention in any way.

In addition, the compounding quantity in the following Examples etc. is mass% unless there is special notice.

The oil-in-water emulsion cosmetics were prepared using the formulations shown in Tables 1 to 5 below, and these characteristics were evaluated according to the following evaluation methods and evaluation criteria. The results are summarized in the table.

1. Evaluation method using touch

Five professional functional inspectors were asked to actually use the samples of the examples and comparative examples to evaluate the feeling of use. In accordance with the following evaluation point criteria, each functional inspector is asked to perform a five-stage evaluation, and the total points are used to make judgments based on the following evaluation criteria.

"Evaluation item" (1) Unique and delicate touch

As defined above, the viscosity decreases sharply when applied to the skin, and the disintegrating touch and moisturizing touch spread to the skin.

(2) Sticky and slippery feeling during fusion

Does not feel sticky when the applied cosmetics are fused to the skin.

"Score"

5: Very good

4: Excellent

3: Ordinary

2: Poor

1: Very poor

"Evaluation Criteria"

A: Total score is 20 points or more

B: Total score is 15~19

C: Total score is 14 points or less

2. Emulsion stability

Two spiral tubes (50 ml) were filled with the sample, and allowed to stand for 2 weeks in a thermostatic bath at 0°C or 50°C. Before and after standing, the viscosity change was measured using a rotary viscometer (Vismetron rotary viscometer), and the emulsified particles and appearance were observed.

"Evaluation Criteria"

A: No decrease in viscosity at any temperature level of 0°C and 50°C, and there is no problem with emulsified particles and appearance.

B: At any temperature level, a slight decrease in viscosity or an increase in emulsified particles or changes in appearance are observed.

C: At any temperature level, a slight decrease in viscosity or an increase in emulsified particles and changes in appearance were observed.

D: At any temperature level, a large decrease in viscosity or an increase in emulsified particles and changes in appearance were observed.

E: At any temperature level, a significant decrease in viscosity or an increase in emulsified particles and changes in appearance were observed.

According to the results shown in Table 1, regarding the use of a hydrophobically modified alkyl cellulose as an emulsifier, a highly polar ultraviolet absorber and a hydrophobic surface treatment ultraviolet scatterer are formulated in the oil phase, and the increase in low salt resistance is used. Water-in-oil emulsified cosmetics (Examples 1 to 5), which are thickened by a water phase with a tackifier, give a unique and delicate touch during application, but the amount of ultraviolet scattering agent does not meet the specific value of Comparative Example 1 In the case, it is not enough to reduce the viscosity of the water phase, and the target use feeling cannot be obtained. Furthermore, even for emulsified cosmetics that use a thickener with a high salt tolerance to thicken the water phase, they cannot obtain a unique and delicate touch.

Regarding the unique and delicate use feeling obtained in Table 1 (Examples 1 to 5), even if the type of the tackifier with low salt resistance formulated in the water phase is changed, it can be exerted (Examples 6 and 7) . However, regarding Example 8 using a type of tackifier (carbomer) that is thickened by crosslinking of molecules, a little stickiness was felt when the cosmetic was fused to the skin.

Examples 9 to 11 in which the polar oil formulated in Example 6 was replaced with other polar oils also obtained a unique feeling of use as in Example 6, and also had excellent emulsion stability.

Regarding Examples 1 to 11 shown in Tables 1 to 3, the ratio of polar oil to the total oil content exceeds 55%, showing extremely excellent emulsion stability, but the implementation of the ratio of polar oil to the total oil content is less than 55% In Examples 12 to 14, the emulsion stability was slightly reduced (however, to a practically problem-free level). In addition, regarding Example 15 in which EDTA-3Na is added as a chelating agent in Example 12, the emulsification stability is improved by the addition of a chelating agent, but there is a tendency for the unique delicate touch to be slightly reduced. . It can be considered that the reason is that part of the electrolyte is captured by the chelating agent, and the sudden decrease in viscosity is slightly hindered. Therefore, it is presumed that the chelating agent formulated in the emulsified cosmetic of the present invention is preferably kept to a minimum.

According to the results shown in Table 5, regarding the hydrophobically modified alkyl cellulose as an emulsifier, the viscosity of the water phase is thickened using a thickener with low salt resistance, and the polar oil ratio in the oil phase is set to 55% by mass In the above Examples 16 to 19, regardless of the type of the substrate and surface treatment agent of the ultraviolet scattering agent having a hydrophobic surface formulated in the oil phase, a unique and delicate touch feeling is obtained, and it is further confirmed that the emulsion stability is also extremely excellent .

(Example 20)

An oil-in-water emulsion sunscreen cosmetic was prepared according to the composition shown below. The obtained cosmetics impart a unique and delicate touch like melting when applied to the skin, and the SPF after application is about 55.

Claims (5)

An oil-in-water emulsified cosmetic, characterized in that it contains (A) 0.05 to 1% by mass of hydrophobically modified alkyl cellulose, (B) 5 to 40% by mass of oil, and (C) 2.5 to 30% by mass The ultraviolet scattering agent having a hydrophobic surface, and (D) selected from the group consisting of polyvinyl alcohol, polyvinyl acetate, polyvinyl methyl ether, polyvinylpyrrolidone, copolymers of vinylpyrrolidone and vinyl acetate, carboxyvinyl Polymer, sodium polyacrylate, polyethyl acrylate, polyalkanolamine, copolymer of alkyl methacrylate and dimethylaminoethyl methacrylate, poly-2-acrylamide-2-methylpropanesulfonate Acid, polymethacrylamide trimethylammonium, (acryl dimethyl taurine ammonium/VP) copolymer, dimethyl acrylamide/acryl dimethyl taurine Na) The water phase tackifier with low salt resistance of the group of co-polymers, and the above (C) ultraviolet scattering agent is dispersed in the oil phase, and the polar oil accounts for more than 55% by mass of the above (B) oil content. The cosmetic according to claim 1, wherein the above (A) hydrophobically modified alkyl cellulose is a hydrophobicized hydroxypropyl methyl cellulose. The cosmetic as claimed in claim 1, wherein the above-mentioned (D) low-tolerance water phase tackifier is a water-swellable microgel formed in the water phase by friction of the swollen microgel particles with each other Thickening type of tackifier. The cosmetic as claimed in claim 2, wherein the above-mentioned (D) low-tolerance water-phase tackifier is to form a water-swellable microgel in the water phase by friction of the swollen microgel particles with each other Thickening type of tackifier. The cosmetics according to any one of claims 1 to 4 are sunscreen cosmetics.