Skin cosmetic

Abstract

To provide a skin cosmetic that can stably contain a relatively large amount of an oil agent while retaining a small average particle diameter, and that leaves the skin moisturized after application and exhibits a prolonged skin-softening effect.SOLUTION: A skin cosmetic comprises the following components (A), (B), and (C): (A) fine particles having an average particle diameter of 1 to 200 nm and containing (a) a phospholipid, (b) a sterol, and (c) a liquid ester oil; (B) a divalent alcohol; and (C) water.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to skin cosmetics.

Background Art

[0002] Phospholipids are components that make up the lipid bilayer of cells and are so-called surfactants derived from living organisms that have a hydrophobic group and a hydrophilic group in one molecule. Therefore, it is considered to have a high affinity for living organisms, and research on its application to cosmetics has been conducted for many years.

[0003] Conventionally, when a large amount of an oil agent having an emollient effect is highly formulated in a lotion, it is common to use a large amount of a polyoxyethylene-based surfactant. For example, Patent Document 1 describes a "skin cosmetic composition containing phospholipids, polyoxyethylene sterol ether having an average added mole number of ethylene oxide of 15 to 50 and / or polyoxyethylene stanol ether having an average added mole number of ethylene oxide of 15 to 50, a monohydric aliphatic alcohol having 12 to 24 carbon atoms with a branched chain, a polyhydric alcohol, water, sterol, an oil component, and polyoxyethylene hydrogenated castor oil having an average added mole number of ethylene oxide of 5 to 30", which can contain a relatively large amount of the oil component and is described as being excellent in transparency and storage stability. In addition, formulating an oil agent without relying on surfactants other than phospholipids has also been studied. For example, Patent Document 2 describes a "transparent or translucent liquid cosmetic composition containing phospholipids as a main dispersant, sterol, a component derived from an oil agent that is solid or paste-like at normal temperature and in an undispersed state, a polyhydric alcohol, and water", which can stably disperse a component derived from a solid or paste-like oil agent.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when emulsifying using plant-derived phospholipids instead of polyoxyethylene-based surfactants, there was a problem that the emulsion particle size became large and the appearance became milky white like an emulsion. Also, when a large amount of thickener was added to stabilize the emulsion particles, the viscosity increased, making it difficult to obtain a liquid lotion form while having a high content of the oil agent. Moreover, in a composition containing an oil agent without depending on surfactants other than phospholipids as in Patent Document 2, it was difficult to formulate a high content of the oil agent, and in particular, it was difficult to stably formulate a liquid oil agent.

Means for Solving the Problems

[0006] The present inventors have found that by dispersing an oily component containing (a) phospholipids, (b) sterols, and (c) a liquid ester oil as fine particles, a skin cosmetic can be obtained that contains a high content of the liquid oil agent while maintaining a fine average particle size, has excellent stability, and maintains the skin softening effect.

[0007] The present invention relates to a skin cosmetic containing the following components (A), (B), and (C): (A) Fine particles having an average particle size of 1 to 200 nm, containing (a) phospholipids, (b) sterols, and (c) a liquid ester oil, (B) A dihydric alcohol, (C) Water

Effects of the Invention

[0008] The skin cosmetic of the present invention can stably contain a relatively large amount of a functional oil agent while maintaining a small average particle size, and the skin after application is moist and has a long-lasting skin softening effect.

Modes for Carrying Out the Invention

[0009] ​ Component (A) used in the present invention contains (a) phospholipids, (b) sterols, and (c) liquid ester oils, and is fine particles having an average particle diameter of 1 to 200 nm. As the phospholipid of component (a), from the viewpoints of improving stability while maintaining a small average particle diameter, improving the moist feeling of the skin after application, and improving the long-term skin softening effect of the skin after application, the phosphatidylcholine content is preferably 60% by mass or more, more preferably 64% by mass or more, still more preferably 68% by mass or more, and even more preferably 70% by mass or more. Examples of phospholipid components other than phosphatidylcholine include phosphatidic acid, phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylglycerol, and the like.

[0010] The phospholipid used in the present invention may be a natural product extracted and purified from animals and plants, a chemically synthesized product, or a product subjected to processing such as hydrogenation and hydroxylation treatment. As the natural product, from the viewpoint of improving stability while maintaining a small average particle diameter, a phospholipid that is an extract from soybeans or egg yolk or a purified product thereof is preferable, and a hydrogenated or hydroxylated phospholipid is more preferable. Specifically, soybean lecithin, egg yolk lecithin, hydrogenated soybean lecithin, and hydrogenated egg yolk lecithin are preferably exemplified.

[0011] The content ratio of phosphatidylcholine in the phospholipid can be analyzed by a method using thin layer chromatography (TLC), high performance liquid chromatography (HPLC), iatrosweep (manufactured by Yatron Co., Ltd.), or the like. For example, there is a method in which an organic solvent containing the phospholipid described in JP-A-2001-186898 is spotted on TLC, developed with chloroform:methanol:acetic acid = 65:25:10, sprayed with 50% by mass sulfuric acid ethanol, heated, and then the phospholipid is analyzed with a densitometer. Any method may be used as long as it can measure and calculate the content and content ratio of phophphatidylcholine contained in the phospholipid other than the above method.

[0012] Examples of phospholipids containing 60% by mass or more of phosphatidylcholine include Coatosome NC-21 (hydrogenated soybean phospholipid; containing 90% by mass or more of phosphatidylcholine; manufactured by NOF Corporation), Phospholipid PCSH70 (hydrogenated soybean phospholipid; containing 70 - 80% by mass of phosphatidylcholine; manufactured by Nippon Fine Chemical Co., Ltd.), Egg yolk lecithin PL-100E (containing approximately 83% by mass of phosphatidylcholine; manufactured by Kewpie Corporation), and the like.

[0013] Also, from the viewpoints of improving stability while maintaining a small average particle size, improving the moist feeling of the skin after application, and improving the long-term skin softening effect of the skin after application, as component (a), a hydrogenated phospholipid having a phosphatidylcholine content of 50% by mass or more and containing 10% by mass or more of acidic phospholipid based on the phosphatidylcholine content is preferable. In this case, the content of phosphatidylcholine is more preferably 60 - 80% by mass, even more preferably 65 - 75% by mass, and the acidic phospholipid is more preferably 10 - 30% by mass based on the phosphatidylcholine content.

[0014] Component (a) can be used singly or in combination of two or more. From the viewpoints of improving stability while maintaining a small average particle size, improving the moist feeling of the skin after application, and improving the long-term skin softening effect of the skin after application, the content is preferably 0.05 - 0.7% by mass, more preferably 0.1 - 0.5% by mass, and even more preferably 0.28 - 0.38% by mass in the total composition. Also, from the viewpoints of improving stability while maintaining a small average particle size, improving the moist feeling of the skin after application, and improving the long-term skin softening effect of the skin after application, the content of component (a) in component (A) is preferably 5 - 35% by mass, more preferably 10 - 30% by mass, even more preferably 14 - 26% by mass, and even more preferably 18.5 - 23.2% by mass.

[0015] Examples of the sterols as component (b) include cholesterol, phytosterol, etc., and cholesterol is preferable.

[0016] Component (b) can be used singly or in combination of two or more. From the viewpoints of improving stability while maintaining a small average particle diameter, improving the moist feeling of the skin after application, and improving the long-term skin softening effect of the skin after application, the content is preferably 0.03 to 0.5% by mass, more preferably 0.065 to 0.3% by mass, and even more preferably 0.095 to 0.15% by mass in the total composition. Further, from the viewpoints of improving stability while maintaining a small average particle diameter, improving the moist feeling of the skin after application, and improving the long-term skin softening effect of the skin after application, the content of component (b) in component (A) is preferably 0.5 to 20% by mass, more preferably 1 to 18% by mass, even more preferably 4 to 15% by mass, and still more preferably 6.2 to 8% by mass.

[0017] In the present invention, the mass ratio (b) / (a) of component (b) to component (a) is preferably 0.05 to 1, more preferably 0.1 to 0.8, even more preferably 0.255 to 0.53, and still more preferably 0.28 to 0.38 from the viewpoints of improving stability while maintaining a small average particle diameter, improving the moist feeling of the skin after application, and improving the long-term skin softening effect of the skin after application.

[0018] In the liquid ester oil of component (c), "liquid" means that the viscosity at 25°C is 10,000 mPa·s or less. The viscosity is measured with a B-type viscometer (VISCOMETER TVB-10, manufactured by Toki Sangyo Co., Ltd.), rotor No. 4, 12 rpm, for 1 minute. Examples of such liquid ester oils include monoester oils, diester oils, triester oils, and the like. Specific examples of the monoester oil include cetyl 2-ethylhexanoate, cetyl octanoate, isononyl isononanoate, isotridecyl isononanoate, isopropyl myristate, octyldodecyl myristate, 2-hexyldecyl myristate, isostearyl isostearate, octyl methoxycinnamate, alkyl benzoate (C12 - C15), and the like. As the monoester oil, from the viewpoint of improving stability while maintaining a small average particle diameter, it preferably contains one or more selected from isononyl isononanoate, isotridecyl isononanoate, 2-hexyldecyl myristate, and isostearyl isostearate, and more preferably contains one or more selected from 2-hexyldecyl myristate and isostearyl isostearate.

[0019] Specific examples of the diester oil include propylene glycol dicaprylate, neopentyl glycol dicaprylate, di(phytosteryl·2-octyldodecyl) N-lauroyl-L-glutamate, diisostearyl malate, and the like. As the diester oil, from the viewpoint of improving stability while maintaining a small average particle diameter, it preferably contains one or more selected from propylene glycol dicaprylate and neopentyl glycol dicaprylate, and more preferably contains neopentyl glycol dicaprylate.

[0020] Specific examples of the triester oil include glyceryl tri(caprylate·caprate), glyceryl tri(2-ethylhexanoate), glyceryl triisostearate, and further include vegetable oils such as olive oil, jojoba oil, macadamia nut oil, meadowfoam oil, castor oil, safflower oil, sunflower oil, avocado oil, canola oil, sesame oil, rice germ oil, and rice bran oil. As the triester oil, from the viewpoint of improving stability while maintaining a small average particle diameter, it preferably contains one or more selected from glyceryl tri(caprylate·caprate), glyceryl tri(2-ethylhexanoate), and vegetable oils, and more preferably contains one or more selected from glyceryl tri(caprylate·caprate), glyceryl tri(2-ethylhexanoate), olive oil, and jojoba oil, and even more preferably contains one or more selected from glyceryl tri(caprylate·caprate) and glyceryl tri(2-ethylhexanoate).

[0021] As the ester oil, from the viewpoint of improving stability while maintaining a small average particle diameter, it preferably contains one or more selected from diester oils and triester oils, and more preferably contains a triester oil.

[0022] Component (c) can be used singly or in combination of two or more. From the viewpoints of improving stability while maintaining a small average particle diameter, improving the moist feeling of the skin after application, and improving the long-term skin softening effect of the skin after application, the content is preferably 0.5 to 5% by mass, more preferably 0.75 to 3% by mass, and even more preferably 1 to 2% by mass in the total composition. Also, from the viewpoints of improving stability while maintaining a small average particle diameter, improving the moist feeling of the skin after application, and improving the long-term skin softening effect of the skin after application, the content of component (c) in component (A) is preferably 52 to 91% by mass, more preferably 61 to 86% by mass, and even more preferably 68 to 81% by mass.

[0023] Component (A) is fine particles containing these components (a), (b) and (c), and may contain a liquid hydrocarbon oil, a silicone oil, etc. in addition to these components. From the viewpoint of improving stability while maintaining a small average particle diameter, the fine particles of component (A) have an average particle diameter of 1 to 200 nm, more preferably 1 to 120 nm, even more preferably 1 to 80 nm, and still more preferably 1 to 70 nm. The average particle diameter is measured by the dynamic light scattering method. Specifically, it is measured using a particle size analyzer (Zetasizer Nano ZS manufactured by Malvern), measured with a 20-fold diluted aqueous solution, and the cumulant diameter is taken as the average particle diameter.

[0024] When the skin cosmetic of the present invention is produced, component (A) is dispersed as fine particles containing components (a), (b) and (c). Component (A) preferably has a content of 0.5 to 2.3% by mass, more preferably 1 to 2.1% by mass, and even more preferably 1.4 to 1.9% by mass in the total composition from the viewpoints of improving stability while maintaining a small average particle size, improving the moist feeling of the skin after application, and improving the long-term skin softening effect of the skin after application.

[0025] The dihydric alcohol of component (B) is a compound having two hydroxyl groups in the molecule, and any one can be used as long as it is used in ordinary cosmetics. Examples of the dihydric alcohol of component (B) include polyethylene glycols such as polyethylene glycol 600 (PEG-12), polyethylene glycol 1500 (a mixture of PEG-6 and PEG-32), and polyethylene glycol 4000 (PEG-75), propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-butylene glycol, propanediol, pentanediol, and the like. Among these, from the viewpoint of improving stability while maintaining a small average particle size, it preferably contains one or more selected from polyethylene glycol, dipropylene glycol, and 1,3-butylene glycol, and more preferably contains one or more selected from dipropylene glycol and 1,3-butylene glycol.

[0026] One or more kinds of component (B) can be used, and from the viewpoint of improving stability while maintaining a small average particle size, the content is preferably 3 to 20% by mass, more preferably 6 to 15% by mass, and even more preferably 9 to 13% by mass in the total composition.

[0027] In the present invention, the water content of component (C) is preferably 63 to 87% by mass, more preferably 67 to 83% by mass, and even more preferably 70 to 80% by mass in the total composition from the viewpoint of improving stability while maintaining a small average particle size.

[0028] The skin cosmetic of the present invention can further contain (D) a polysaccharide, which can improve stability while maintaining a small average particle size and can improve the long-term skin softening effect on the skin after application. The polysaccharide as the component (D) is not limited as long as it can be used in ordinary cosmetics, and it may be derived from natural products or obtained by chemical synthesis.

[0029] In addition, derivatives of polysaccharides obtained by bonding an alkyl group, a hydroxyalkyl group, a polyalkylene oxide group such as a polyethylene oxide group or a polypropylene oxide group, a saccharide such as glucose, lactose, sucrose, or a polymer having these saccharides as constituent units to a part of the sugar of the polysaccharide are also regarded as polysaccharides and are included in the polysaccharide of the component (D).

[0030] Specifically, for example, locust bean gum, guar gum, tamarind gum, quince seed-derived gum, gum arabic, tragacanth gum, karaya gum, carrageenan, alginic acid, pectin, hydroxypropyl guar gum, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, tuberose polysaccharide, xanthan gum, polysaccharide produced by Alcaligenes latus, jellyfish polysaccharide, gellan gum, dextran, pullulan, hyaluronic acid, chondroitin sulfate, dermatan sulfate, chitin, chitosan and other mucopolysaccharides can be mentioned. Among these, from the viewpoints of improving stability while maintaining a small average particle size and improving the long-term skin softening effect on the skin after application, it is preferably contained one or more selected from at least quince seed extract, hydroxypropyl guar gum, xanthan gum, hyaluronic acid, tuberose polysaccharide, and more preferably contains one or more selected from xanthan gum and hyaluronic acid.

[0031] Component (D) can be used in combination of one or more kinds. From the viewpoints of maintaining stability and flexibility, its content is preferably 0.01 to 0.2% by mass, more preferably 0.02 to 0.1% by mass, and still more preferably 0.04 to 0.08% by mass in the whole composition.

[0032] The skin cosmetic of the present invention can further contain (E) an acrylic polymer, and can further enhance stability. Examples of the acrylic polymer as component (E) include those used in ordinary cosmetics, such as acrylamide-based polymers and carboxyvinyl polymers which may be alkyl-modified. The acrylamide-based polymer is one or more polymers selected from the group consisting of homopolymers and copolymers of acrylamide and their derivatives. Polyacrylamide includes polyacrylamide and acrylamide copolymers. Examples of the acrylamide copolymer include copolymers containing acrylamide and / or acryloyldimethyltaurine as constituent units. Examples of the acrylamide-based polymer include polyacrylamide, copolymers of acrylamide and acrylic acid (salt), copolymers of acrylic acid (salt) and acryloyldimethyltaurine (salt), copolymers of hydroxyalkyl acrylate and acryloyldimethyltaurine (salt), copolymers of acrylic acid (salt), acrylamide, acrylic acid (salt), and acryloyldimethyltaurine (salt), copolymers of 2-acrylamido-2-methylpropanesulfonic acid (salt), N,N-dimethylacrylamide, lauryl methacrylate, and lauroxypolyethylene glycol monomethacrylate (4EO), and the like.

[0033] Among the carboxyvinyl polymers which may be alkyl-modified, examples of the carboxyvinyl polymer include polymers containing acrylic acid or methacrylic acid as a constituent monomer. Specifically, examples thereof include Syntalen K, Syntalen L (manufactured by 3V Sigma), Carbopol 910, Carbopol 934, Carbopol 940, Carbopol 941, Carbopol 980, Carbopol 981 (manufactured by Lubrizol Advanced Materials), and the like. Examples of the alkyl-modified carboxyvinyl polymer include polymers containing an ester bond (alkyl modification) of acrylic acid or methacrylic acid and a fatty acid having 1 to 35 carbon atoms as a constituent monomer. Among them, those known as acrylic acid-methacrylic acid alkyl copolymers (acrylic acid-acrylic acid alkyl (C10-30) copolymers) in which the alkyl group has 10 to 30 carbon atoms are preferable from the viewpoints of improving the moist feeling of the skin after application and improving the long-term skin softening effect of the skin after application. Specifically, examples thereof include Carbopol ETD2020, Carbopol 1382, Pemulen TR-1, Pemulen TR-2 (manufactured by Lubrizol Advanced Materials), and the like. As the carboxyvinyl polymer which may be alkyl-modified, the carboxyvinyl polymer is preferable from the viewpoint of improving the stability while maintaining a small average particle diameter.

[0034] Component (E) can be used alone or in combination of two or more. From the viewpoint of stability, the content is preferably 0.02 to 0.2% by mass, more preferably 0.04 to 0.15% by mass, and still more preferably 0.06 to 0.1% by mass in the total composition.

[0035] In addition to the above components, the skin cosmetic of the present invention can contain components usually used in cosmetics, for example, surfactants other than the component (a), antioxidants, fragrances, preservatives, pH adjusters, blood circulation promoters, cooling agents, antiperspirants, bactericides, skin activators, moisturizers other than the component (B), cooling agents, and the like.

[0036] The skin cosmetic of the present invention can be produced according to a conventional method, for example, it can be produced by the following method. First, an oily component containing a part of components (a), (b), (c), and (B) is mixed and heated to dissolve to prepare a uniform oil-phase mixture X. Next, component (C) and other aqueous components are mixed to prepare a uniform water-phase mixture Y. These are each caused to flow in a certain amount, and they are made to merge and emulsified using a micromixer that causes them to flow through pores with a pore diameter of 0.03 to 20 mm, whereby it can be produced.

[0037] From the viewpoint of improving stability while maintaining a small average particle diameter, the transmittance of the skin cosmetic of the present invention is preferably 30 to 100%, more preferably 60 to 100%, still more preferably 80 to 100%, and even more preferably 90 to 100%. In the present invention, the transmittance is measured at a wavelength of 550 nm using a transmittance measuring device (Shimadzu ultraviolet-visible spectrophotometer UV-1800, manufactured by Shimadzu Corporation) for a 20-fold aqueous dilution of the skin cosmetic. As the measurement cell, a disposable cell (for near-UV PMMA) manufactured by BRAND is used.

[0038] The skin cosmetic of the present invention is a liquid skin cosmetic in which fine particles of component (A) are dispersed in the aqueous phase. For example, it is suitable as a lotion, a beauty liquid, a gel, etc., and can also be a mist in which a lotion is filled in a spray container.

Examples

[0039] Examples 1 to 9, Comparative Examples 1 to 4 Skin cosmetics having the compositions shown in Tables 1 and 2 were produced, and their stability and skin effects were evaluated. The results are shown together in Tables 1 and 2.

[0040] (Manufacturing method) First, a tank containing a part of components (a), (b), (c), and (B) was prepared, and the liquid temperature was adjusted to 80°C and heated and dissolved to prepare a uniform oil-phase mixture X. Next, a tank containing component (C) and other preservative components was prepared, and the liquid temperature was maintained at 25°C to prepare a uniform water-phase mixture Y. The mixtures X and Y were flowed in a certain amount and merged, and then passed through pores with a pore diameter of 0.6 mm. At this time, the flow rate was controlled so that the total flow rate was 170 g / min. Also, the inlet temperature of the oil-phase mixture X to the pores where it merges with the water-phase mixture Y was controlled at 45°C, and the inlet temperature of the water-phase mixture Y to the pores where it merges with the oil-phase mixture X was controlled at 12.5°C. Due to the above temperature difference, a liquid emulsion Z was obtained. Other components such as components (D) and (E) were sequentially mixed into the emulsion Z and sufficiently stirred with a propeller to obtain a skin cosmetic.

[0041] (Evaluation method) (1) Stability: For each skin cosmetic, immediately after production and after filling it into a standard glass container (glass bottle No. 88, manufactured by Koga Glass Co., Ltd.) and storing it at 5°C or 45°C for 2 weeks, the transmittance and average particle size were measured. (1-1) Transmittance: For each skin cosmetic, the transmittance of a 20-fold water-diluted solution was measured using a transmittance measuring device (Shimadzu UV-Visible Spectrophotometer UV-1800, manufactured by Shimadzu Corporation). The transmittance was measured at a wavelength of 550 nm. The measurement cell used was a disposable cell (PMMA for near UV) manufactured by BRAND. (1-2) Average particle size: For each skin cosmetic, the cumulant diameter obtained by measuring a 20-fold water-diluted solution by dynamic light scattering using a particle size analyzer (Zetasizer Nano ZS manufactured by Malvern) was determined. The measurement cell used was KUVETTEN CUVETTES 67.754 POYSTYROL / POLYSTYRENE 10 X 10 X 45 MM.

[0042] (2) Skin effect: Three professional evaluators each applied 0.1 g of each skincare product to the back of their hands, massaged it, felt the skin immediately afterwards, and conducted sensory evaluations on the "softness of the skin" and "moist feeling" according to the following criteria. The results were shown as the total scores of the three professional evaluators. Note that "softness of the skin" means that when force is applied vertically with a finger to the skin to which each skincare product has been applied, it is easy to press. 5: Strongly feel it. 4: Feel it. 3: Slightly feel it. 2: Slightly do not feel it. 1: Do not feel it.

[0043]

Table 1

[0044]

Table 2

[0045] Formulation Examples 1 - 5 In the same manner as in Examples 1 - 9, skincare products with the compositions shown in Tables 3 - 7 were manufactured. For all of the obtained skincare products, the fine particles of component (A) have an average particle diameter of 1 - 200 nm. Also, all of the skincare products have high stability and provide a moist feeling on the skin after application and a long - lasting skin softening effect.

[0046]

Table 3

[0047]

Table 4

[0048]

Table 5

[0049]

Table 6

[0050]

Table 7

Claims

Claim 1 The following components (A), (B) and (C): (A) (a) phospholipids, (b) sterols, (c) a liquid ester oil, and fine particles having an average particle diameter of 1 to 200 nm, (B) a dihydric alcohol, (C) water A skin cosmetic containing the same. Claim 2 The skin cosmetic according to Claim 1, wherein (a) the phospholipid is contained in the total composition in an amount of 0.05 to 0.7% by mass. Claim 3 The skin cosmetic according to Claim 1 or 2, wherein (b) the sterols are contained in the total composition in an amount of 0.03 to 0.5% by mass. Claim 4 The skin cosmetic according to Claim 1 or 2, wherein the mass ratio (b) / (a) of (b) the sterols to (a) the phospholipids is 0.05 to 1. Claim 5 The skin cosmetic according to Claim 1 or 2, further containing (D) a polysaccharide. Claim 6 The skin cosmetic according to Claim 1 or 2, further containing (E) an acrylic acid polymer.

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