JP5348876B2 - Oil-in-water emulsified cosmetic - Google Patents

Description

  The present invention relates to an oil-in-water emulsified cosmetic.

In recent years, more excellent hypoallergenicity is expected for cosmetics. From this viewpoint, various emulsification techniques using so-called polymer emulsifiers have been proposed.
For example, a method for dispersing oil droplets in hydrated gels of PEMULEN TR-1 and TR-2 (Noveon), which are hydrophobically modified poly (meth) acrylates, and ACULYN22 (Rohm & Haas) is known. (Patent Document 1, Non-Patent Document 1).

  However, these hydrophobically modified poly (meth) acrylates have low emulsifying power, and an appropriate viscosity is required to ensure the emulsion stability. That is, since an emulsion having a fine particle size cannot be prepared, creaming occurs when the viscosity is low, and gelation occurs over time when the viscosity is high, and the usability of the emulsified composition is remarkably deteriorated. In particular, there has been a problem that it is impossible to produce a composition having a low viscosity such as a lotion.

Various amphiphilic polymers having a nonionic hydrophilic group and a lipophilic group have been proposed (Patent Document 2, Patent Document 3, and Patent Document 4). However, there is no example specifically describing the use of these as emulsifiers, and when these are used for emulsification of oily components, it is difficult to obtain an emulsion composition in which the average particle size of oil droplets is fine, In particular, it was difficult to obtain an oil-in-water emulsion composition having excellent stability.
JP-A-8-217624 Japanese Patent Laid-Open No. 5-39320 JP 2001-316422 A JP-A-6-73369 FRAGRANANCE JOURNAL, 1998-8, p. 79

  An object of the present invention is to provide an oil-in-water emulsified cosmetic having excellent stability and good usability.

  The present inventors have used a specific polymer emulsifier and an oil component in a specific ratio, and by using a combination of a water-soluble organic solvent and water, the oil-in-water emulsion makeup with excellent stability and good usability. It was found that a fee can be obtained.

The present invention includes the following components (A), (B), (C) and (D):
(A) a polymeric emulsifier comprising a nonionic hydrophilic structural unit (a) and a hydrophobic structural unit (b),
(B) oily component,
(C) a water-soluble organic solvent,
(D) An oil-in-water emulsified cosmetic containing water and having a mass ratio of components (A) and (B) of (A) / (B) = 0.1-10 is provided.

  The oil-in-water emulsified cosmetic of the present invention has a fine average particle size of oil droplets, is excellent in stability, and has a good feeling of use.

  The polymer emulsifier of component (A) used in the present invention comprises a nonionic hydrophilic structural unit (a) and a hydrophobic structural unit (b).

  Here, the hydrophilicity in the hydrophilic structural unit means that the monomer forming the structural unit has a solubility in distilled water at 20 ° C. (g / 100 g water) of 8 or more. Means that the monomer forming the structural unit has a solubility (g / 100 g water) in distilled water at 20 ° C. of less than 8.

  Since the emulsified composition of the polymer emulsifier (A) / oil / water system forms a solubilized state or a low interfacial tension in a limited temperature range below the cloud point of the polymer emulsifier (A), From the viewpoint of obtaining an emulsified composition having a large amount of oil droplets and a fine average particle diameter of oil droplets, the cloud point of the polymer emulsifier (A) is higher than normal temperature (25 ° C) and lower than the boiling point of water. Preferably, the thing of 50-90 degreeC is more preferable, The thing of 50-70 degreeC is still more preferable.

  Here, the cloud point is a temperature at which the polymer starts to insolubilize from the solution when the temperature of the aqueous solution of the polymer emulsifier (A) is raised, and details of the cloud point measurement conditions are as shown in the Examples. It is.

From the viewpoint of controlling the cloud point of the polymer emulsifier (A) to 50 to 90 ° C., the proportion of the nonionic hydrophilic structural unit (a) in all the constituent units constituting the polymer emulsifier of component (A) is as follows: 30-90 mass% is preferable, and 40-80 mass% is more preferable. Moreover, the ratio of the hydrophobic structural unit (b) in all the structural units is preferably 10 to 70% by mass and more preferably 20 to 60% by mass from the viewpoint of obtaining sufficient emulsification performance.
In order to obtain a good O / W emulsion, it is preferable to select the proportion of the above structural units so that the HLB of the polymer emulsifier is 6-15. HLB is calculated as (inorganic / organic) × 10 by the organic conceptual projection.

  Particularly preferred as the polymer emulsifier of component (A) is one having a structural unit represented by the general formula (1) and a structural unit represented by the general formula (2).

(Wherein R ¹ , R ² , R ³ , R ⁶ , R ⁷ and R ⁸ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and R ⁴ has 1 to ⁴ carbon atoms. A linear or branched alkylene group, R ⁵ represents an alkyl group having 1 to 2 carbon atoms, R ⁹ represents a linear or branched alkyl group or alkenyl group having 1 to 30 carbon atoms, and X ¹ And X ² represents an oxygen atom or NH, and n represents a number of 1 to 30.)

  Examples of the nonionic hydrophilic structural unit (a) include a structural unit derived from a nonionic hydrophilic monomer (hereinafter referred to as nonionic hydrophilic monomer (a)), and hydrophilicity derived from a nonionic hydrophilic group after polymerization. Sex structural units and the like.

  Examples of the nonionic hydrophilic monomer (a) include methoxypolyethylene glycol (meth) acrylate, methoxypoly (ethylene glycol / propylene glycol) mono (meth) acrylate, ethoxypoly (ethylene glycol / propylene glycol) mono (meth) acrylate, polyethylene Examples include glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, hydroxyethyl acrylamide, and polyethylene glycol monoacrylamide.

  In these, the nonionic hydrophilic monomer represented by General formula (3) is preferable.

(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , X ¹ , and n have the above-mentioned meanings.)
In general formula (3), R ¹ and R ² are preferably hydrogen atoms. R ⁴ is preferably an ethylene group or a propylene group, and more preferably an ethylene group. X ¹ is preferably an oxygen atom. n is preferably 2 to 14, particularly 4 to 9.
In particular, methoxy polyethylene glycol (meth) acrylate having a polyethylene oxide chain polymerization degree of 1 to 30, particularly 2 to 14, and further 4 to 9 is more preferable.

  Examples of the hydrophobic structural unit (b) include a structural unit derived from a hydrophobic monomer (hereinafter referred to as hydrophobic monomer (b)), a hydrophobic structural unit to which a hydrophobic group is added after polymerization, and the like.

  As the hydrophobic monomer (b), a hydrophobic monomer represented by the general formula (4) is preferable.

(In the formula, R ⁶ , R ⁷ , R ⁸ , R ⁹ and X ² have the above-mentioned meanings.)
In the general formula (4), R ⁶ and R ⁷ are preferably hydrogen atoms. R ⁹ is preferably an alkyl group or an alkenyl group having 4 to 24 carbon atoms, particularly 8 to 22 carbon atoms, and further 12 to 18 carbon atoms from the viewpoint of emulsion stability. Specific examples include octyl group, 2-ethylhexyl group, decyl group, lauryl group, myristyl group, cetyl group, stearyl group, oleyl group, and behenyl group. X ² is preferably an oxygen atom.

  Specific examples of the hydrophobic monomer (b) include butyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, butyl (meth) acrylamide, octyl ( Examples include meth) acrylamide, lauryl (meth) acrylamide, stearyl (meth) acrylamide, and behenyl (meth) acrylamide. Of these, lauryl (meth) acrylate and stearyl (meth) acrylate are preferred.

The arrangement of the nonionic hydrophilic structural unit (a) and the hydrophobic structural unit (b) may be random, block, or graft. Moreover, structural units other than these structural units may be included.
The polymer emulsifier (A) can be obtained by a known synthesis method. For example, it can be obtained by polymerizing a monomer component containing a nonionic hydrophilic monomer (a) and a hydrophobic monomer (b) by a solution polymerization method.

  Examples of the solvent used for the solution polymerization include aromatic hydrocarbons (toluene, xylene, etc.), lower alcohols (ethanol, isopropanol, etc.), ketones (acetone, methyl ethyl ketone), ethers (tetrahydrofuran, diethylene glycol dimethyl ether, etc.), etc. Organic solvents can be used. The solvent amount (mass basis) is preferably 0.5 to 10 times the total amount of monomers.

As the polymerization initiator, known radical polymerization initiators can be used, and examples thereof include azo polymerization initiators, hydroperoxides, dialkyl peroxides, diacyl peroxides, and ketone peroxides. The amount of the polymerization initiator is preferably from 0.01 to 5 mol%, more preferably from 0.01 to 3 mol%, particularly preferably from 0.01 to 1 mol%, based on the total amount of the monomer components.
The polymerization reaction is preferably performed in a temperature range of 60 to 180 ° C. under a nitrogen stream, and the reaction time is preferably 0.5 to 20 hours.

  The weight average molecular weight of the polymer emulsifier (A) is preferably from 5,000 to 1,000,000, more preferably from 10,000 to 200,000, from the viewpoints of irritation to skin and emulsification performance. The weight average molecular weight is a value measured by GPC (gel permeation chromatography), and details of the measurement conditions are as shown in the examples.

  The polymer emulsifier of component (A) can be used alone or in combination of two or more, and from the viewpoint of obtaining excellent emulsification stability, preferably from 0.01 to the total composition of the emulsified cosmetic of the present invention. The content is 10% by mass, more preferably 0.1 to 10% by mass.

  The oil component of the component (B) used in the present invention may be either volatile or non-volatile, and the form at normal temperature may be any of solid, paste, and liquid. For example, hydrocarbons such as solid or liquid paraffin, petrolatum, ceresin, ozokerite, montan wax, squalane, squalene; eucalyptus oil, mint oil, camellia oil, macadamia nut oil, avocado oil, beef fat, pork fat, horse oil, egg yolk Oils, olive oil, carnauba wax, lanolin, jojoba oil and other oils; glycerin monostearate, diglyceryl monoisostearate, glyceryl distearate, glyceryl monooleate, isopropyl palmitate, isopropyl stearate, butyl stearate, Isopropyl myristate, neopentyl glycol dicaprate, diethyl phthalate, myristyl lactate, diisostearyl malate, diisopropyl adipate, di-2-heptylundecyl adipate, Cetyl ristate, cetyl lactate, 1-isostearoyl-3-myristoyl glycerol, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, 2-octyldodecyl myristate, neopentyl glycol di-2-ethylhexanoate, oleic acid Ester oils such as 2-octyldodecyl, glycerol triisostearate, glycerol tricaprate, diparamethoxycinnamate mono-2-ethylhexanoate glyceryl; ether oils such as cetyl 1,3-dimethylbutyl ether; stearic acid, palmitic acid, oleic acid, etc. Higher fatty acids such as stearyl alcohol, cetyl alcohol, etc .; natural essential oils such as rosemary, rooibos, royal jelly, hamamelis; lignan, vitamin E, oil-soluble vitamin C, vitamin A Conductors, ceramides, ceramide-like structural substances (for example, N- (3-hexadecyloxy-2-hydroxypropyl) -N-2-hydroxyethylhexadecanamide; see JP-A-62-228048), oil In addition to functional oily substances such as soluble ultraviolet absorbers and fragrances, silicones and fluorine-based oils can be used.

  Among these oily components (B), in combination with the polymer emulsifier (A), from the viewpoint of providing an emulsified composition having significantly superior storage stability over time than the existing nonionic emulsifier, an organic concept Oily component of 0 ≦ inorganicity ≦ 100 and organicity of 500 or less, 100 <inorganicity ≦ 200 and organicity of 600 or less on the diagram (Organic Conceptual Diagram, Yoshio Koda, Sankyo Publishing, 1984) It is preferable that at least one selected from oily components of 200 <inorganicity ≦ 300 and organicity of 700 or less, and 300 <inorganicity and organicity of 800 or less.

  Examples of oily components having 0 ≦ inorganic ≦ 100 and organic property of 500 or less include liquid paraffin such as decane, isopropyl palmitate, isopropyl stearate, butyl stearate, isopropyl myristate, cetyl 2-ethylhexanoate, palmitic Examples include acid 2-ethylhexyl, stearyl alcohol, cetyl alcohol and the like.

  Oily components with 100 <inorganic ≦ 200 and organicity of 600 or less include neopentyl glycol dicaprate, diethyl phthalate, myristyl lactate, diisopropyl adipate, cetyl lactate, neopentyl glycol di-2-ethylhexanoate, Examples include stearic acid and palmitic acid.

  Examples of the oil component with 200 <inorganic ≦ 300 and organic property of 700 or less include glycerin monostearate, glycerin monooleate, diisostearyl malate, and glycerol tricaprate.

  300 <Inorganic and organic components having an organic property of 800 or less include diglyceryl monoisostearate and the like.

  The oil component of the component (B) can be used alone or in combination of two or more, and from the viewpoint of obtaining excellent emulsion stability, preferably 0.01 to 10 in the entire composition of the emulsified cosmetic of the present invention. It is contained by mass%, more preferably 0.1-5 mass%.

  Moreover, the mass ratio of (A) polymer emulsifier and (B) oil component is (A) / (B) = 0.1-10 from the viewpoint of obtaining excellent emulsification stability, preferably 0.2. ˜2, particularly preferably 0.5˜1.

  As the water-soluble organic solvent of component (C) used in the present invention, any water-soluble organic solvent that is usually used in cosmetics can be used as long as it is liquid at room temperature. For example, lower alcohols such as ethanol and isopropanol; ethylene glycol, propylene glycol, Glycols such as dipropylene glycol, isoprene glycol, 1,3-butylene glycol, polyethylene glycol (average molecular weight 200 to 1540); polyhydric alcohols such as polyoxyethylene methyl glucoside, glycerin, diglycerin; tris (2- (2 -Ethoxyethoxy) ethyl) phosphate and the like.

  The water-soluble organic solvent of component (C) can be used singly or in combination of two or more, and is preferably 0 in the total composition of the emulsified cosmetic of the present invention from the viewpoint of obtaining a finer and more stable emulsion. 0.1-30 mass%, More preferably, 0.1-20 mass% is contained.

  Although the water of a component (D) can be contained arbitrarily, from the viewpoint of obtaining excellent emulsification stability, the total composition of the emulsified cosmetic of the present invention is preferably 50 to 99% by mass, more preferably 60 to 99% by mass. % Content.

The cosmetic of the present invention can further contain a whitening agent, and a high whitening effect can be obtained.
The whitening agent is not particularly limited as long as it is used in ordinary cosmetics. For example, L-ascorbic acids, hydroquinones such as arbutin, kojic acids, tranexamic acids, ellagic acids, lucinols, linoleic acids, 4- Examples include alkoxysalicylic acids such as methoxysalicylic acid potassium salt, and placenta extract.

  Among these, L-ascorbic acids are not particularly limited, and for example, L-ascorbic acid phosphate sodium salt, which is a monovalent metal salt of L-ascorbic acid phosphate, L-ascorbic acid phosphate L-ascorbic acid phosphate magnesium salt, L-ascorbic acid phosphate calcium calcium salt, trivalent metal salt L-ascorbic acid phosphate aluminum salt; L-ascorbic acid sulfate sodium salt, L-ascorbic acid sulfate potassium salt, divalent metal salt L-ascorbic acid sulfate potassium magnesium salt, L-ascorbic acid sulfate, monovalent metal salt of acid sulfate L-a which is a calcium salt and a trivalent metal salt L-ascorbic acid sodium salt, L-ascorbic acid potassium salt, divalent metal salt L-ascorbic acid magnesium salt, L-ascorbic acid calcium salt Preferable examples include salts such as L-ascorbic acid aluminum salt, L-ascorbic acid-2-O-glucoside, and ascorbyl tetra-2-hexyldecanoate, which are trivalent metal salts.

  Among these whitening agents, L-ascorbic acid-2-O-glucoside, arbutin, kojic acid, linoleic acid, ellagic acid, and lucinol derivatives are particularly preferable.

  One or more kinds of these whitening agents can be used. From the viewpoint of the whitening effect, the emulsion stability and the feeling of use, 0.01 to 30% by mass, particularly 0.01 to 10% by mass, in addition, The content of 0.01 to 5% by mass is preferable because a sufficient whitening effect can be obtained and the usability and stability are excellent.

  Moreover, in this invention, the plant extract which has a whitening effect | action can also be used as a whitening agent. Such plant extracts include, for example, Asen, Altea, Aloe, Ogon, Dutch mustard, oysters, cuckoo, chamomile, licorice, kina, magnolia, ginseng, comfrey, hawthorn, citrus, ginger, ginger, mulberry. Examples thereof include extracts obtained from plants such as leather, tea, clove, spruce, elderberry, barley winter, loquat, matsukasa, rosemary, funnel, and bitumen.

  These plant extracts were pulverized by drying or without drying one or more parts (hereinafter referred to as “raw materials”) of the whole plant or its leaves, flowers, bark, roots, branches, etc. Thereafter, it can be obtained by extraction with a solvent or extraction using an extraction tool such as a Soxhlet extractor at room temperature or under heating. Here, the solvent used is not particularly limited. For example, water; primary alcohol such as methanol, ethanol, propanol; liquid polyhydric alcohol such as propylene glycol, 1,3-butylene glycol; liquid fatty acid such as ethyl acetate. Lower alkyl esters; hydrocarbons such as benzene, hexane, liquid paraffin; solvents such as ethyl ether and acetone; castor oil, persic oil, soybean oil, isopropyl myristate, lower fatty acid triglycerides, intermediate fatty acid triglycerides, sunflower oil, dicapric acid neo It can be obtained by extraction with an oil such as pentyl glycol or squalane. One or more of these solvents can be used. Among these, as the extraction solvent, ethanol, 1,3-butylene glycol, neopentyl glycol dicaprate, and squalane are preferable.

  As a specific example of a preferred method for extracting from the active ingredient, 1000 mL of 50 v / v% ethanol is added to 100 g of the dry pulverized product, and extraction is performed for 3 days while occasionally stirring at room temperature. The obtained extract is filtered, and the filtrate is allowed to stand at 5 ° C. for 3 days and then filtered again to obtain a supernatant. The plant extract obtained under the above conditions may be used as it is, but it can be further subjected to concentration, filtration or the like if necessary.

  Of these, chamomile extract generally contains azulene, camazulene, umbelliferone, 7-methoxycoumarin, matricin, matricalin, taraxasterol, lupeol, apiin, chroman, spiroether and the like. As a preferable method for extracting chamomile, for example, the following method may be mentioned.

  Dry and shred the chamomile flowers. Squalane is added thereto, and the mixture is immersed from room temperature to 50 ° C. with occasional stirring, followed by pressing and separation to obtain an extract. This extract is filtered to obtain a chamomile extract.

  One or more kinds of these plant extracts can be used, and in terms of dry solid content, the total composition is 0.0001 to 20% by mass, particularly 0.0001 to 10% by mass, and further 0.0001 to 5%. The content by mass% is preferable because an excellent effect of preventing and improving stains and freckles can be obtained, and the feeling of use and stability are excellent.

  In addition to the above components, the oil-in-water emulsified cosmetic of the present invention is a component used in ordinary cosmetics such as preservatives, antioxidants, fragrances, ultraviolet absorbers, moisturizers, blood circulation promoters, and cooling sensates. , Antiperspirants, bactericides, skin protectants, water-soluble polymers, plant extracts, surfactants, pH adjusters, thickeners, and the like.

The oil-in-water emulsion composition of the present invention can be produced by mixing and emulsifying the blending components.
In addition, when the components (A) to (D) are mixed and heated to a solubilization temperature range, preferably 50 to 90 ° C. with stirring, or in a solubilized state, or when the amount of oil agent is large and the solubilized state does not occur In a state where the interfacial tension in the temperature range of the cloud point is low, after holding for a certain time, preferably 10 minutes or more, by cooling to 40 ° C. or less, preferably 30 ° C. or less, more preferably 0 to 30 ° C., Can be manufactured. The temperature range of the cloud point is preferably in the range of 10 ° C. below the cloud point to 5 ° C. higher than the cloud point, more preferably in the range of 5 ° C. lower than the cloud point to 3 ° C. higher than the cloud point. .

  In order to obtain an emulsified composition having a large content of the oil component (B) and a fine average particle diameter of oil droplets, the polymer emulsifier (A) is at a certain concentration or more, particularly 5% by mass in the step before cooling. It is preferable to use the above. The emulsion composition after cooling can be diluted with water as necessary. Although a water-soluble organic solvent can be added in all steps, it is preferably added in the emulsification step in order to control the average particle size of oil droplets with the water-soluble organic solvent (C).

  In the present invention, each component may be added and mixed by stirring and mixing by an ordinary method. For example, a homogenizer, an ultrasonic emulsifier, a high-pressure emulsifier or the like can be used.

In the present invention, the average particle size of the oil droplets is controlled by selecting the ratio of the polymer emulsifier (A) and the oil component (B) and the type and amount of the water-soluble organic solvent (C). Can do. The average particle diameter of the oil droplets in the oil-in-water emulsified cosmetic of the present invention is preferably 5 to 200 nm, more preferably 5 to 100 nm.
In order to control the average particle size of the oil droplets with the water-soluble organic solvent (C), it is particularly preferable to use 5 to 30% by mass of the water-soluble organic solvent (C) in the emulsification step. By reducing the average particle size and increasing the emulsification efficiency, stability and usability can be expected.

In the present invention, the average particle diameter of the emulsified oil droplets is 6 μm or more, the arithmetic average diameter obtained from the micrograph is used, and those having an average particle diameter of 6 μm or less are the dynamic light scattering particle size distribution measuring device LB. The arithmetic average diameter (volume average) calculated | required from the scattered light intensity | strength measured using -500 (made by HORIBA) is used.
Moreover, the transmittance | permeability% uses the transmittance | permeability% of the 1-cm cell of visible light which has a wavelength of 550 nm measured using UV-VISIBLE RECORDING SPECTROMETER (made by SHIMADZU).
These measurements are performed at 25 ° C.

  The oil-in-water emulsified cosmetics of the present invention include, for example, foundations, lotions, creams, emulsions, skin lotions, skin softening cosmetics, nutritional cosmetics, astringent cosmetics, whitening cosmetics, wrinkle improving cosmetics, and anti-aging cosmetics. It can be applied as skin cosmetics such as antiperspirants and deodorants, and as a skin external preparation.

  The measurement conditions and evaluation methods for each physical property in the following synthesis examples and examples are summarized below.

<Weight average molecular weight measurement conditions>
The weight average molecular weight of the polymer emulsifier is a weight average molecular weight in terms of polystyrene measured by GPC using a 0.5% by mass solution obtained by dissolving the polymer emulsifier in chloroform under the following conditions.
GPC measurement conditions Column: KF-804L (manufactured by Showa Denko), 2 eluents: 1 mmol / L Farmin DM20 (manufactured by Kao) / CHCl ₃ , flow rate: 1.0 mL / min, column temperature: 40 ° C., detection Instrument: Differential refractometer

<NMR measurement conditions>
The proportion of each structural unit in all the structural units of the polymer emulsifier was determined by measuring a 1% by mass solution of the polymer emulsifier dissolved in deuterium-substituted dimethyl sulfoxide by proton nuclear magnetic resonance spectrum.

<Cloud point measurement conditions>
The cloud point was confirmed according to the following method in accordance with the book written by Shinsei Surfactant, Takehiko Fujimoto, Sanyo Chemical Industries, 1992). That is, a 5% by mass aqueous solution of the polymer emulsifier is held at a constant temperature for 30 minutes to observe whether the polymer emulsifier is insolubilized from the solution. The temperature at which the polymer emulsifier began to become insoluble when the temperature was raised was taken as the cloud point.
Alternatively, in the mixed solution of the polymer emulsifier, the oil component, and water, the temperature at which the entire system becomes cloudy when the temperature is raised is defined as the cloud point.

<Solubilization condition confirmation conditions>
It was confirmed according to the following method that the system was in a solubilized state. That is, a mixed solution of a polymer emulsifier, an oil component, and water is held at a constant temperature for 10 minutes to observe whether the turbidity of the solution changes. Since the turbidity of the solution increases when the system is not in the solubilized state, the system is said to be in the solubilized state when the turbidity of the solution does not change.

<Average particle size>
At 25 ° C., the average particle diameter obtained from the micrograph is used for those having a particle diameter of 6 μm or more, and the dynamic light scattering particle size distribution analyzer LB-500 (manufactured by HORIBA) is used for those having a particle diameter of 6 μm or less. The arithmetic average diameter (volume average) obtained from the scattered light intensity measured by using was used.

<Viscosity>
The measurement was performed at 25 ° C. using a B8L viscometer (manufactured by Tokyo Keiki Co., Ltd.).

<Transparency>
At 25 ° C., the transmittance% of a 1 cm cell of visible light having a wavelength of 550 nm, which was measured using UV-VISIBLE RECORDING SPECTROMETER (manufactured by SHIMADZU), was used.

<Stability>
After the oil-in-water emulsion composition was stored at room temperature for 1 month, the degree of creaming and separation was visually evaluated according to the following criteria.
A: No change.
B: Although the transmittance slightly decreases, there is no difference in visual evaluation.
C: Slightly lower transparency and slightly creaming, but with a slight share, the creaming is unknown.
D: Creaming and separation are clearly recognized.

Synthesis Example 1 (Synthesis of polymer emulsifier (A-1))
In a reactor equipped with a stirrer, reflux condenser, thermometer, and nitrogen introduction tube, 60 g of methoxypolyethylene glycol (9 mol) methacrylate, 40 g of lauryl methacrylate, and 100 g of polymerization solvent methyl ethyl ketone, initiator V-65 (Wako Pure Chemical Industries, Ltd.) (Product) 1.0g was prepared, and the polymerization reaction was performed at 65 degreeC for 6 hours. Thereafter, drying was performed to obtain a polymer emulsifier (A-1). The weight average molecular weight of the obtained polymer emulsifier (A-1) was 73,000. The proportion of the structural unit derived from methoxypolyethylene glycol (9 mol) methacrylate in all the structural units of the obtained polymer emulsifier (A-1) was 63 mass%, and the proportion of the structural unit derived from lauryl methacrylate was 37 mass%. It was. The cloud point of the polymer emulsifier (A-1) was 60 ° C. The HLB (calculated value) was 11.2.

Synthesis Example 2 (Synthesis of polymer emulsifier (A-2))
A polymer emulsifier (A-2) having a weight average molecular weight of 69,000 was obtained by synthesizing under the same conditions as in Synthesis Example 1 except that 40 g of stearyl methacrylate was used instead of 40 g of lauryl methacrylate. The proportion of the structural unit derived from methoxypolyethylene glycol (9 mol) methacrylate in all the structural units of the obtained polymer emulsifier (A-2) was 60% by mass, and the ratio of the structural unit derived from stearyl methacrylate was 40% by mass. It was. The cloud point of the polymer emulsifier (A-2) was 60 ° C. The HLB (calculated value) was 10.0.

Example 1 and Comparative Examples 1 to 4
Oil-in-water emulsified cosmetics having the composition shown in Table 1 were produced, and the average particle size and viscosity were measured, and the stability was evaluated. The results are also shown in Table 1.

(Production method)
(1) Example 1:
After the polymer emulsifier was dissolved in 9 times the amount of purified water, squalane was added and mixed and stirred at 60 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. This was mixed with the remaining purified water and other components by a conventional method to obtain an oil-in-water emulsion cosmetic.

(2) Comparative Examples 1 to 4:
After mixing and dissolving paraoxybenzoic acid methyl ester, 86% glycerin and purified water at 80 ° C., an acrylic acid / alkyl methacrylate copolymer was added with stirring, and after dissolution, neutralized with an aqueous L-arginine solution. Thereafter, squalane was added with stirring and held for 20 minutes, and then cooled to room temperature to obtain an emulsified composition.

  The oil-in-water emulsified cosmetic of the present invention had a fine average particle diameter of oil droplets, excellent stability, and good usability. In contrast, in Comparative Examples 1 to 4 using an acrylic acid / alkyl methacrylate copolymer, the average particle size of the oil droplets is large, and those having low viscosity cream, so that only a high viscosity formulation can be obtained. It was.

Examples 2-3
An oil-in-water emulsified cosmetic composition having the composition shown in Table 2 was produced, and the average particle size, permeability and stability were evaluated. The results are also shown in Table 2.

(Production method)
(1) Example 2:
The polymer emulsifier was dissolved in 9 times the amount of purified water, neopentyl glycol dicaprate was added, and the mixture was stirred at 60 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. This was mixed with the remaining purified water and other components by a conventional method to obtain an oil-in-water emulsion cosmetic.
(2) Example 3:
A water-soluble organic solvent and a polymer emulsifier were dissolved in 7.65 times purified water, 1,3-butylene glycol and neopentyl glycol dicaprate were added, and mixed and stirred at 60 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. This was mixed with the remaining purified water and other components by a conventional method to obtain an oil-in-water emulsion cosmetic.

Examples 4-6, Comparative Example 5
An oil-in-water emulsified cosmetic composition having the composition shown in Table 3 was produced, and the average particle size, permeability and stability were evaluated. The results are also shown in Table 3.

(Production method)
The polymer emulsifier was dissolved in 9 times the amount of purified water, and the oil was mixed and stirred at 60 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. This was mixed with the remaining purified water and other components by a conventional method to obtain an oil-in-water emulsion cosmetic.

Example 7
A whitening oil-in-water emulsified cosmetic composition having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 1.0.
The resulting oil-in-water emulsion composition had an average particle size of oil droplets of 53 nm.

(Production method)
A polymer emulsifier is dissolved in 7.65 times purified water, 1,3-butylene glycol, neopentyl glycol dicaprate and chamomile extract are added thereto, mixed and stirred at 60 to 85 ° C., and held for 30 minutes And cooled to room temperature. This was mixed with the remaining purified water and other ingredients by a conventional method to obtain a whitening oil-in-water emulsified cosmetic.

(component)
Polymer emulsifier (A-2) 1 (mass%)
Neopentyl glycol dicaprate 1
Chamomile extract 0.5
86% glycerin 2.5
1,3-butylene glycol 1.35
Ethanol 5
Polyethylene glycol 1540 0.3
Eucalyptus extract 1
Sodium monohydrogen phosphate 0.033
Sodium dihydrogen phosphate 0.017
P-Hydroxybenzoic acid methyl ester 0.15
Pullulan PI-20 0.01
Purified water balance

Example 8
A whitening oil-in-water emulsified cosmetic composition having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 0.67.
The resulting oil-in-water emulsion composition had an average particle size of oil droplets of 59 nm.

(Production method)
A polymer emulsifier is dissolved in 9.56 times the amount of purified water, and 1,3-butylene glycol, squalane, dipentaglycol neopentyl glycol, N- (3-hexadecyloxy-2-hydroxypropyl) -N- Hydroxyethylhexadecanamide and silicone (6cs) were added and mixed and stirred at 85 ° C. After stirring at that temperature for 30 minutes, the mixture was cooled to room temperature. This was mixed with the remaining purified water and other ingredients by a conventional method to obtain a whitening oil-in-water emulsified cosmetic.

(component)
Polymer emulsifier (A-2) 0.8 (mass%)
Squalane 0.5
Neopentyl glycol dicaprate 0.4
N- (3-hexadecyloxy-2-hydroxypropyl) -N-
Hydroxyethyl hexadecanamide 0.2
Silicone (6cs) 0.1
86% glycerin 2.5
1,3-butylene glycol 1.35
Jiyu extract 1
P-Hydroxybenzoic acid methyl ester 0.15
Purified water balance

Example 9
A whitening oil-in-water emulsified cosmetic composition having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 1.5.
The obtained oil-in-water emulsion composition had an average particle diameter of oil droplets of 33 nm.

(Production method)
The polymer emulsifier was dissolved in 17 times the amount of purified water, 1,3-butylene glycol and neopentyl glycol dicaprate were added thereto, and mixed and stirred at 60 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. This was mixed with the remaining purified water and other ingredients by a conventional method to obtain a whitening oil-in-water emulsified cosmetic.

(component)
Polymer emulsifier (A-2) 0.45 (mass%)
Neopentyl glycol dicaprate 0.3
86% glycerin 2.5
1,3-butylene glycol 1.35
L-ascorbic acid-2-glucoside 2
Jiyu extract 1
P-Hydroxybenzoic acid methyl ester 0.15
Sodium monohydrogen phosphate 0.033
Sodium dihydrogen phosphate 0.017
Purified water balance

Example 10
An oil-in-water emulsified cosmetic for sensitive skin having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 0.67.
The obtained oil-in-water emulsion composition had an average particle size of oil droplets of 64 nm.

(Production method)
The polymer emulsifier was dissolved in 9.56 times the amount of purified water, and 1,3-butylene glycol and neopentyl glycol dicaprate were added thereto, followed by mixing and stirring at 60 to 85 ° C. After stirring at that temperature for 10-30 minutes, the mixture was cooled to room temperature. This was mixed with the remaining purified water and other components by a conventional method to obtain an oil-in-water emulsion composition for sensitive skin.

(component)
Polymer emulsifier (A-2) 0.8 (mass%)
Neopentyl glycol dicaprate 1.2
86% glycerin 2.5
1,3-butylene glycol 1.35
Dipotassium glycyrrhizinate 0.1
Asunaro Extract 1
P-Hydroxybenzoic acid methyl ester 0.15
Sodium monohydrogen phosphate 0.033
Sodium dihydrogen phosphate 0.017
Purified water balance

Example 11
A whitening oil-in-water emulsified cosmetic composition having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 1.0.
The obtained oil-in-water emulsion composition had an average particle size of oil droplets of 50 nm.

(Production method)
A polymer emulsifier was dissolved in 9 times the amount of purified water, and 1,3-butylene glycol, neopentyl glycol dicaprate, and chamomile extract were added thereto, and mixed and stirred at 60 to 85 ° C. After stirring at that temperature for 30 minutes, the mixture was cooled to room temperature. This was mixed with the remaining water and other components by a conventional method to obtain a whitening oil-in-water emulsified cosmetic.

(component)
Polymer emulsifier (A-2) 1 (mass%)
Neopentyl glycol dicaprate 1
Chamomile extract 0.5
86% glycerin 1
1,3-butylene glycol 1
Ethanol 5
Polyethylene glycol 1540 0.3
Altea extract 1
Sodium monohydrogen phosphate 0.033
Sodium dihydrogen phosphate 0.017
Carboxyvinyl polymer (Carbopol 980, manufactured by Noveon) 0.3
Potassium hydroxide 0.15
P-Hydroxybenzoic acid methyl ester 0.15
Purified water balance

  All of the oil-in-water emulsified cosmetics obtained in Examples 7 to 11 had excellent stability and good usability.

Claims (6)

The following components (A), (B), (C) and (D):
(A) A polymeric emulsifier comprising a nonionic hydrophilic structural unit (a) derived from methoxypolyethylene glycol (meth) acrylate and a hydrophobic structural unit (b) derived from lauryl (meth) acrylate or stearyl (meth) acrylate .01 to 10% by mass,
(B) Oil component 0.01 to 10% by mass,
(C) 0.1-30 mass% of water-soluble organic solvent,
(D) It contains water, and component (A) is 60 to 63% by mass of nonionic hydrophilic structural unit (a) and 37 to 40% by mass of hydrophobic structural unit (b) in all the structural units. is intended to include a proportion by weight of components (a) and (B), (a) / (B) = a 0.1-10, average particle diameter of the oil droplets, oil is 5~200nm Type emulsified cosmetic. Component (C) is, lower alcohols, glycols and water emulsified cosmetic composition of claim 1 wherein the water-soluble organic solvent selected from polyhydric alcohols. The oil-in-water emulsion cosmetic according to claim 1 or 2 , wherein in component (A), the degree of polymerization of the polyethylene oxide chain of methoxypolyethylene glycol (meth) acrylate is 4-9. The oil-in-water emulsified cosmetic according to any one of claims 1 to 3 , wherein the component (A) has a weight average molecular weight of 10,000 to 200,000. After the system in which the components (A), (B), (C) and (D) are mixed is solubilized in the solubilization temperature range, or the interfacial tension in the temperature range of the cloud point of the component (A) is The oil-in-water emulsified cosmetic according to any one of claims 1 to 4 , which is obtained by cooling to 40 ° C or lower after being brought to a low state. The oil-in-water emulsified cosmetic according to claim 5 , wherein the solubilization temperature range is 50 to 90 ° C.