JP2012067024A - Skin care preparation for external use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stable skin care preparation for external use, in the form of an oil-in-water-type emulsified product containing large-sized oily particles enough to be visible by human eyes, being well-compatible with the skin when applied to the skin, and free from any stickiness and filmy feeling.SOLUTION: The skin care preparation for external use is characterized by being in the form of an oil-in-water-type emulsified product with oily particles of 0.05-10 mm in average size dispersed in an aqueous phase; wherein each of the oily particles contains a solid oily fraction with a melting point of 55-75°C, and the aqueous phase consists of an emulsified product containing a carboxyvinyl polymer and a polyoxyethylene-based associable thickening agent. In addition, it is preferable that this skin care preparation for external use contains a moisturizer.

Description

  The present invention relates to an external preparation for skin consisting of an oil-in-water emulsion containing relatively large oil-based particles, having good skin familiarity and having no film feeling after application.

  Oil-in-water emulsions are characterized by a fresh feeling of use and are widely used as a base for external preparations for skin such as cosmetics. In oil-in-water emulsions, water and oil components are usually easily separated when the dispersed oily particles are large. Therefore, in stable emulsions, small (approximately 50 μm or less) oily particles are used. It was adjusted.

  On the other hand, in Patent Document 1, an amphiphilic substance having a melting point in a predetermined range is blended in a predetermined ratio as an oil component, emulsified in a state heated to the melting point of the amphiphilic substance or more, and in an aqueous phase. It is described that by adding a thickener, an oil-in-water emulsion in which relatively large oil particles of 100 μm or more are stably dispersed can be prepared.

  The emulsion thus prepared is not only visually novel and beautiful due to the dispersion of oily particles of a visible size covered with the amphiphile, but also when applied to the skin. It has a fresh and refreshing feel, and a sense of use unprecedented, such as a moist feel over time. However, for example, an emulsion in which a carboxyvinyl polymer is blended as a thickener in the aqueous phase is not sufficient in terms of skin familiarity, and a film feeling may be felt after application.

  In Patent Document 2, when the dextrin fatty acid ester, preferably further hydrogenated polyisobutene, is blended in the oil phase of the oil-in-water emulsion including those described in Patent Document 1, the stability is improved and the particles are uniform. It is described that the property is improved. However, it has not yet solved the problem of skin familiarity and film feeling.

JP 2003-73230 A JP 2005-36001 A

  Therefore, the problem in the present invention is an oil-in-water emulsion containing oily particles that are large enough to be visually observed, has good skin familiarity when applied to the skin, has no stickiness or film feeling, and is stable for external use. Is to provide an agent.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by blending a polyoxyethylene-based associative thickener in addition to a carboxyvinyl polymer as a thickener added to the aqueous phase. The present invention has been completed.

  That is, the present invention is an oil-in-water emulsion in which oily particles having an average particle diameter of 0.05 to 10 mm are dispersed in an aqueous phase, and the oily particles contain a solid oil component having a melting point of 55 to 75 ° C. And providing an external preparation for skin, wherein the aqueous phase comprises an emulsion containing a carboxyvinyl polymer and a polyoxyethylene-based associative thickener.

  The external preparation for skin of the present invention is an oil-in-water emulsion in which relatively large oily particles are stably dispersed, and not only has a unique visual effect and feeling of use, but also in large oily particles. It is possible to add a large amount of an oily component to the. Furthermore, the skin external preparation of the present invention has good skin familiarity when applied to the skin, and does not have stickiness or film feeling.

  The external preparation for skin of the present invention comprises an oil-in-water emulsion, and its aqueous phase (continuous phase) comprises a carboxyvinyl polymer (including an alkyl-modified carboxyvinyl polymer) as a thickener and a polyoxyethylene-based associative thickener. Contains the agent.

  The polyoxyethylene-based associative thickener used in the present invention (hereinafter sometimes simply referred to as “associative thickener”) is described in detail, for example, in JP-A-2000-234085. A copolymer having a hydrophobic part at both ends of a hydrophilic part, wherein the hydrophilic part is composed of a polyoxyethylene chain, and the hydrophobic parts of the copolymer are associated with each other in an aqueous medium to increase the viscosity. It is a thickener which shows.

Specifically, the following general formula (1):
RB- (X-B) _n- R (1)
(Wherein R represents a hydrophobic moiety, X represents a hydrophilic moiety obtained by addition polymerization of an alkylene oxide containing ethylene oxide to an organic compound having at least two active hydrogen groups, and B represents a bonding group of an ether group or an ester group. And n represents an integer of 1 to 5. Among these, a copolymer having a weight ratio of hydrophilic part to hydrophobic part of 5: 1 to 1000: 1, hydrophilic A copolymer in which the functional part X is polyethylene oxide, in particular, the hydrophobic part R is a monovalent hydrocarbon group having 6 or more carbon atoms or a monovalent fluorocarbon group having 4 or more carbon atoms, and the hydrophilic part of the copolymer Is a polyethylene oxide having an ethylene oxide unit of 30 to 6000 (integer).

The associative thickener in the present invention may be a commercially available product. For example, the trade name “Adecanol GT-700 (Asahi Denka Kogyo)” (display name: (PEG-240 / decyltetradeceth-20 / HDI) copolymer) Particularly preferred examples are mentioned.
The compounding quantity of the associative thickener in this invention is 0.05-0.7 mass%, More preferably, it is 0.05-0.5 mass%. If the blending amount is less than 0.05% by mass, the desired effect cannot be obtained, and if it exceeds 0.7% by mass, the viscosity tends to be excessively increased.

  The carboxyvinyl polymer may be one conventionally used as a thickener in cosmetics and the like. Moreover, in the skin external preparation of this invention, it is preferable to mix | blend and combine a carboxy vinyl polymer and an alkyl modified carboxy vinyl polymer, and stability of oil-based particle | grains improves further by mix | blending these both.

  The compounding quantity of the carboxy vinyl polymer in this invention is 0.05-0.7 mass%, More preferably, it is 0.1-0.4 mass%. If the blending amount is less than 0.05% by mass, the desired effect cannot be obtained, and if it exceeds 0.7% by mass, stickiness tends to occur.

The oil phase (dispersed phase) of the oil-in-water emulsion constituting the external preparation for skin of the present invention is oily particles having an average particle diameter of 0.05 to 10 mm.
The oily particles contain a solid oil component having a melting point of 55 to 75 ° C. as an essential component. By blending and preparing a solid oil component having a melting point of 55 to 75 ° C., a solid oil film is formed (encapsulated) on the outer surface of the oil particles, and adhesion between oil particles can be suppressed. It becomes.

  Examples of solid oils used in the present invention include hydrogenated jojoba oil (melting point: 68 ° C.), glyceryl behenate (melting point: 66 ° C.), behenyl alcohol (melting point: 68 ° C.), stearyl alcohol (melting point: 58 ° C.), solid paraffin (melting point: 59-91 ° C.), microcrystalline wax (melting point: 80 ° C.), ceresin (melting point: 68-75 ° C.), bees wax (melting point: 64 ° C.), polyethylene wax (melting point: 80 ° C), silicon wax (melting point: 60 ° C), batyl alcohol (melting point: 70 ° C), carnauba wax (melting point: 83 ° C), beeswax (melting point: 64 ° C), candelilla wax (melting point: 71 ° C), jojobarrow ( Melting point: 55 ° C.) Owl (melting point: 55 ° C.), hardened castor oil (melting point: 84 ° C.), hardened oil (melting point: 55-60 ° C.) Hydrogenated palm oil (melting point: 65 ° C.), hardened palm oil (melting point: 70 ℃), 12- hydroxystearic acid (mp: 70 ° C.) and the like can be given.

  The blending amount of the solid oil in the oily particles is preferably about 5 to 25% by mass with respect to the total mass of the oily particles. If the solid oil content is less than 5% by mass, stickiness when applied to the skin tends to agglomerate, and if it is more than 25% by mass, a crisp feel when applied to the skin becomes obvious. In addition, the tendency for skin contact to deteriorate is recognized.

In addition to the solid oil component, other oil components are blended in the oil particles (oil phase). Other oily components include, for example, dextrin fatty acid esters and liquid oils.
Examples of dextrin fatty acid esters include one or more of dextrin palmitate, dextrin oleate, dextrin stearate, dextrin myristate, etc., and it is preferable to select dextrin palmitate. .

  Liquid oil is a liquid oil at room temperature, such as linseed oil, camellia oil, macadamia nut oil, corn oil, olive oil, avocado oil, sasanqua oil, castor oil, safflower oil, kyonin oil, cinnamon oil, jojoba oil, Grape oil, almond oil, rapeseed oil, sesame oil, sunflower oil, wheat germ oil, rice germ oil, rice bran oil, cottonseed oil, soybean oil, peanut oil, tea seed oil, evening primrose oil, triglycerin, glycerin trioctanoate, triiso Oils such as glyceryl palmitate, coconut oil, palm oil, and palm kernel oil are included.

  Also, octanoic acid esters such as cetyl octanoate, glycerin tri-2-ethylhexanoate, isooctanoic acid esters such as tetra-2-ethylhexanoic acid pentaerythritol, lauric acid esters such as hexyl laurate, isopropyl myristate, Myristic acid ester such as octyldodecyl myristate, palmitic acid ester such as octyl palmitate, stearic acid ester such as isocetyl stearate, isostearic acid ester such as isopropyl isostearate, isopalmitic acid ester such as octyl isopalmitate, oleic acid Oleic acid esters such as isodecyl, adipic acid diesters such as diisopropyl adipate, sebacic acid diesters such as diethyl sebacate, and diacid malates such as diisostearyl malate Ester oils such as stearyl also included.

  Also, hydrocarbon oils such as liquid paraffin, ozokerite, squalane, squalene, pristane, paraffin, isoparaffin, petrolatum; sterols; and chain silicones such as dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, decamethyl Cyclic silicone such as cyclopentasiloxane and dodecamethylcyclohexasiloxane, amino-modified silicone oil, polyether-modified silicone oil, carboxy-modified silicone oil, alkyl-modified silicone oil, ammonium salt-modified silicone oil, fluorine-modified silicone oil and other silicone oils included.

The external preparation for skin of the present invention preferably further contains a moisturizing agent. By blending a humectant, the moist feeling and smoothness after application can be further improved.
The humectant may be usually blended in a skin external preparation such as cosmetics, and is not particularly limited. For example, polyhydric alcohols such as glycerin, dipropylene glycol, 1,3-butylene glycol, and ethylene glycol, sorbitol, etc. Sugar alcohol, hyaluronic acid and the like.

  The compounding quantity of the humectant in this invention is 10-30 mass%, More preferably, it is 15-25 mass%.

The external preparation for skin of the present invention may further contain other optional components that are usually blended in external preparations for skin such as cosmetics, as long as the effects of the present invention are not impaired.
Other components include water-soluble ingredients to be blended in the aqueous phase, for example, water-soluble drugs such as arbutin, ascorbic acid glucoside, tranexamic acid, 4-methoxysalicylate, and water-soluble ultraviolet absorbers such as dimorpholinopyridazinone. And chelating agents such as sodium edetate, pH adjusters such as citric acid and sodium citrate, preservatives such as paraben and phenoxyethanol, water-soluble dyes, water-soluble fragrances, and surfactants. In addition, the components blended in the oil phase include UV absorbers such as octyl paramethoxycinnamate and t-butylmethoxybenzoylmethane, UV scattering agents such as fine particle titanium oxide and fine particle zinc oxide, oil-soluble vitamins, oil Examples include soluble plant extracts, other oil-soluble drugs, oil-soluble fragrances, oil-soluble dyes and pigments.

  The skin external preparation of the present invention can be prepared according to a method as described in Patent Document 1 or 2, for example. Specifically, a water phase component containing a humectant is mixed and heated to the melting point or higher of the solid oil, and the oil phase component heated and mixed at the same temperature is stirred and then added to the water phase component and cooled while stirring. Can be adjusted.

  Hereinafter, the present invention will be described in more detail with specific examples, but the present invention is not limited to the following examples. Moreover, the compounding quantity in a following example etc. shows the mass% unless there is particular notice.

(Examples and Comparative Examples)
Emulsion compositions having the compositions listed in Table 1 and Table 2 below were prepared.
Production method:
(1) Numbers 2, 3, 4, and 10 were added to number 1 and mixed, and then heated to about 75 ° C.
(2) The mixture of (1) was stirred at 150 rpm with a propeller mixer, and numbers 5 to 9 heated to 85 ° C. were added.
(3) The mixture was cooled to 30 to 40 ° C. while continuing the stirring in (2).
(4) After adding No. 11-13 to the emulsion of (3) and stirring uniformly, No. 14 was added and mixed.

Each prepared composition was evaluated for viscosity, particle size, stability over time (one month at 50 ° C. or 0 ° C.), and usability. The evaluation method is as follows.
·viscosity:
It was measured with a digital bismetholone viscometer VDA type (BL type, 12 rpm (using No. 4 rotor) and BH type, 10 rpm (using No. 6 rotor)).
·Particle size:
The particle diameter was measured by observation with an optical microscope.
・ Stability over time:
The state after standing at 50 ° C. and 0 ° C. for 1 month was observed.
Evaluation criteria:
○: No change in appearance △: White turbidity in water phase is observed ×: Particles cannot maintain a dispersed state (particle floating)

・ Usability:
A test article was applied to the forearm of 10 female panels, and the sense of application was evaluated for each item according to the following evaluation criteria.
“Good skin comfort” “No coating feeling after application” “Smoothness after application”
○: Very felt ○ △: Slightly felt △: Almost unsatisfactory ×: Not felt at all "stickiness after application"
○: I do not feel at all ○ △: I do not feel almost △: I feel a little × I feel very much

  As is apparent from the results shown in Tables 1 and 2, Examples 1 to 7 in which appropriate amounts of polyoxyalkylene-based associative thickener and carboxyvinyl polymer were blended were excellent in stability over time and usability. On the other hand, Comparative Examples 1 and 2, which do not contain a polyoxyalkylene-based associative thickener, have poor skin familiarity when applied, have a film feeling, and lack smoothness. Moreover, the comparative example 2 with many compounding quantities of a carboxy vinyl polymer also had a sticky touch. Further, the blending amount of the polyoxyalkylene-based associative thickener was 1% by mass, and Comparative Example 3 in which the carboxyvinyl polymer was blended showed a sharp increase in viscosity, lacking stickiness and smoothness. In Comparative Example 4 in which no polymer was blended, the stability over time was poor and the usability was poor.

  Although the formulation example of the skin external preparation which concerns on this invention is described below, as for the result of the said test, all of these formulation examples were stable and excellent in usability.

Formulation Example 1
(Ingredient) (mass%)
(1) Ion exchange water Remaining amount (2) Glycerin 8
(3) Dipropylene glycol 7
(4) 1,3-butylene glycol 3
(5) Carboxyvinyl polymer 0.05
(6) Alkyl-modified carboxyvinyl polymer 0.02
(7) Xanthan gum 0.1
(8) Associative thickener ^* 0.3
(9) Potassium hydroxide 0.03
(10) Candelilla wax 1.2
(11) Dextrin palmitate 0.06
(12) Tetra-2-ethylhexanoic acid pentaerythrit 3.6
(13) Dimethylpolysiloxane 2.4
(14) EDTA-2Na.2H2O 0.01
(15) Phenoxyethanol 0.5
(*) Adecanol GT-700 (Asahi Denka Kogyo)

Manufacturing methods (1) to (4), (14) and (15) are mixed and heated to 75 ° C. This is stirred at 150 rpm with a propeller mixer, and (6) and (10) to (13) heated to 85 ° C. are added. This is cooled to 30-40 degreeC. (5), (7) and (8) are added and mixed with this, and then (9) is added and mixed.

Formulation Example 2
(Ingredient) (mass%)
(1) Ion exchange water remaining amount (2) Glycerin 3
(3) Dipropylene glycol 5
(4) 1,3-butylene glycol 7
(5) Polyoxyethylene methyl glucoside 0.5
(6) Carboxyvinyl polymer 0.3
(7) Alkyl-modified carboxyvinyl polymer 0.01
(8) Associative thickener ^* 0.3
(9) Potassium hydroxide 0.03
(10) Polyoxyethylene hydrogenated castor oil 0.1
(11) Polyglyceryl diisostearate 0.15
(12) Candelilla wax 0.6
(13) Dextrin palmitate 0.03
(14) Tetra-2-ethylhexanoic acid pentaerythritol 1.8
(15) Dimethylpolysiloxane 1.2
(16) Glyceryl tri-2-ethylhexanoate 0.15
(17) EDTA-2Na.2H2O 0.01
(18) Phenoxyethanol 0.5
(*) Adecanol GT-700 (Asahi Denka Kogyo)

Production Method (1), (2), (3), (17), (18) are mixed and heated to 75 ° C. This is stirred at 150 rpm with a propeller mixer, and (7) and (12) to (15) heated to 85 ° C. are added. This is cooled to 30-40 degreeC. (4), (5), (10), (11), and (16) are mixed by heating and mixed, and then (6) and (8) are added and mixed. Add (9) to this and mix.

Formulation Example 3
(Ingredient) (mass%)
(1) Ion exchange water Remaining amount (2) Alcohol 8
(3) Glycerin 4
(4) Dipropylene glycol 7
(5) 1,3-butylene glycol 3
(6) Polyoxyethylene (14) Polyoxypropylene (7) Dimethyl ether
3
(7) Xylit 1
(8) Sodium hyaluronate 0.1
(9) Carboxyvinyl polymer 0.4
(10) Alkyl-modified carboxyvinyl polymer 0.04
(11) Xanthan gum 0.1
(12) Associative thickener ^* 0.3
(13) Potassium hydroxide 0.03
(14) Candelilla wax 0.6
(15) Dextrin palmitate 0.03
(16) Tetra-2-ethylhexanoic acid pentaerythrit 1.8
(17) Dimethylpolysiloxane 1.2
(18) EDTA-2Na.2H2O 0.01
(19) Phenoxyethanol 0.2
(20) Methylparaben 0.15
(*) Adecanol GT-700 (Asahi Denka Kogyo)

Production method (1) to (4), (14), (15) are mixed and heated to 75 ° C. This is stirred at 150 rpm with a propeller mixer, and (6) and (10) to (13) heated to 85 ° C. are added. This is cooled to 30-40 degreeC. (5), (7) and (8) are added and mixed with this, and then (9) is added and mixed.

Claims (4)

An oil-in-water emulsion in which oily particles having an average particle size of 0.05 to 10 mm are dispersed in an aqueous phase, wherein the oily particles contain a solid oil component having a melting point of 55 to 75 ° C., and the aqueous phase An external preparation for skin comprising an emulsion containing a carboxyvinyl polymer and a polyoxyethylene-based associative thickener. The skin external preparation according to claim 1, further comprising a moisturizing agent. The external preparation for skin according to claim 1 or 2, wherein the blending amount of the polyoxyethylene-based associative thickener is 0.05 to 0.7 mass%. The skin external preparation according to any one of claims 1 to 3, wherein the polyoxyethylene-based associative thickener is a PEG-240 / decyltetradeceth-20 / HDI) copolymer. .