JP2000281533A - Coated powder and composition containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject powder well dispersible in an aqueous medium and excellent in stability without aggregating even in the presence of an acrylic thickener by coating a powder with a specific core-shell type emulsion resin. SOLUTION: This powder is obtained by coating a powder with a core-shell type emulsion resin having an acrylic water-soluble polymer [preferably the polymer containing (meth)acrylic acid, an acrylic or a methacrylic ester, styrene, etc.], in the shell and a water-insoluble polymer (preferably the polymer of styrene, an α-alkylstyrene, etc.), in the inner core. The powder to be coated is preferably a powder in which the surface is pretreated with a hydrogenmethylpolylsiloxane, dimethylpolysiloxane and a silane coupling agent. The ratio of the powder to the core-shell type emulsion is preferably (95.5:0.5) to (50:50). Thereby, a powder-dispersed cosmetic excellent in stability can be obtained in the presence of an aqueous medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a coated powder suitable for an aqueous dispersion foundation and the like.

[0002]

2. Description of the Related Art In a powder-containing cosmetic such as a foundation, which contains an aqueous component, it is necessary to stably disperse a powder having a specific gravity of 3 or more in a medium having a specific gravity of 1 or less. Therefore, measures must be taken to increase the viscosity of the system and to suppress the settling of such powders. As such means, usually, means for utilizing a gel structure of a fatty acid soap or utilizing a gel structure of a polysaccharide are already known. Among these, when a fatty acid soap gel is used, an oily component such as a higher alcohol is required for forming such a gel structure. Therefore, it is difficult to use an aqueous medium dispersion system. However, it was difficult to make a liquid formulation.

On the other hand, as a thickening means in a system containing no powder, there is a thickening means using an acrylic thickener such as a carboxyvinyl polymer. In this case, since the powders have an aggregating action, they have a disadvantage that they cannot be used in the aqueous medium dispersion system as described above. In order to prevent such agglomeration,
Treatment of powder surface is considered, but amino acid derivative treatment,
Known treatment methods, such as silicone treatment, phosphate treatment, and metal soap treatment, have drawbacks such as the inability to prevent agglomeration, low affinity between the powder and the aqueous medium, and a problem with stability. It was difficult to take appropriate measures. In addition, there are cases where makeup has a problem due to high hydrophilicity, such as flowing into sweat.

On the other hand, a core-shell type emulsion resin having an acrylic water-soluble polymer in the outer shell and a water-insoluble polymer in the inner core is already known to be used in cosmetics as a film-forming agent and the like. It is also excellent in that the powder is coated with this, and that the powder coated with the core-shell emulsion polymer does not cause agglomeration even in a system in which a thickener such as a carboxyvinyl polymer is present, and that it has good makeup. Was not known at all.

[0005]

SUMMARY OF THE INVENTION The present invention has been made under such circumstances, and an object of the present invention is to provide a powder-dispersed cosmetic composition having excellent stability in the presence of an aqueous medium.

[0006]

In view of such circumstances, the present inventors have intensively researched for a powder dispersion cosmetic having excellent stability in the presence of an aqueous medium. In the outer shell, to a powder coated with a core-shell type emulsion resin having a water-insoluble polymer in the inner core,
They have found that they are well dispersed in an aqueous medium and do not agglomerate even when an acrylic thickener such as a carboxyvinyl polymer is present, thereby completing the invention. Hereinafter, the present invention will be described in detail focusing on embodiments.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Coating Powder of the Present Invention The coating powder of the present invention is coated with a core-shell type emulsion resin having an acrylic water-soluble polymer in an outer shell and a water-insoluble polymer in an inner core. It is characterized by having been done. Powder serving as a substrate of the coating powder of the present invention,
Any powder that is usually used in cosmetics can be used as a base without any particular limitation. Examples of such powders include titanium dioxide, zinc oxide, yellow iron oxide,
Iron oxide such as red iron oxide, black iron oxide, Gunjou, navy blue, talc, sericite, mica, kaolin, silica, calcium silicate, magnesium silicate, methylsiloxane network polymer, cross-linked methylpolysiloxane, titanium mica, titanium sericite, etc. Can be preferably exemplified. These powders can be coated with the polymer as it is, or can be coated after the surface has been surface-treated in advance. As the surface treatment method, any commonly used treatment method can be used without any particular limitation.For example, silicone treatment by baking hydrogen methyl polysiloxane, dimethyl polysiloxane, or the like, silane coupling agent Silane coupling treatment, perfluoroalkyl treatment with perfluoroalkyl phosphate or perfluoroalkylsilane, metal soap treatment with metal soap such as zinc stearate, acyl amino acid treatment with acyl glutamate, silica gel coating treatment, etc. Can be preferably exemplified. The substrate of the coating powder of the present invention is preferably subjected to a surface treatment, particularly preferably a silicone treatment by baking hydrogen methyl polysiloxane, dimethyl polysiloxane or the like. As surface-treated powder,
The preferred amount of surface treatment is 1 to 10% by weight based on the total amount of the powder.

The polymer used for coating the coating powder of the present invention has an acrylic water-soluble polymer in its outer shell,
It is a core-shell emulsion resin having a water-insoluble polymer in the inner core. Of course, in addition to such polymers, plasticizers and other polymers can be arbitrarily coated as long as the effect of the present invention is not impaired. Belongs to the range.
Such a resin is, in the presence of a surfactant, in an aqueous solution of a water-soluble acrylic resin, a monomer constituting a water-insoluble polymer and azobisisobutyronitrile, cumene hydroperoxide, potassium persulfate, etc. It can be produced by adding and polymerizing a polymerization initiator. Preferred examples of the water-soluble acrylic resin include acrylic acid, methacrylic acid and salts thereof, and polymers containing vinyl alcohol and the like as constituent monomers. Specifically, acrylic acid and salts thereof, methacrylic acid and salts thereof, acrylic acid Esters, methacrylates, styrene and α
Preferred examples include one or more polymers and / or copolymers selected from -alkylstyrenes. Among them, a polymer obtained by polymerizing only such constituent monomers is preferable. Further, as the water-insoluble polymer of the core part, a polymer and / or a copolymer containing one or two or more selected from styrene, α-alkylstyrene, acrylate and methacrylate as constituent monomers Can be preferably exemplified, and among them, a polymer and / or a copolymer containing only these as a constituent monomer is particularly preferable. Here, the core: shell ratio is 20:80 to 8
0:20 is preferable, and 30:70 to 70:30 is more preferable.

The ratio of the powder to the core-shell emulsion polymer in the coated powder of the present invention is 95.5: 0.
5-50: 50 is preferable, and 99: 1-70: 30 is more preferable. This is because if the amount of the polymer is too small, the coating effect may not be obtained, and if the amount of the polymer is too large, the properties of the powder may not be obtained. The coating powder of the present invention can be produced by treating these powders, the core-shell type emulsion polymer, and the aqueous medium with a dispersion apparatus using a medium such as a sand grind mill or a dyno mill. In the case of manufacturing using such an apparatus, it is particularly preferable to use zirconia beads as a medium in terms of dispersibility and durability.

(2) Cosmetic of the present invention The cosmetic of the present invention is characterized by containing the above-mentioned coating powder. Since the coating powder of the present invention does not agglomerate even in the presence of an acrylic thickener, it is preferably applied to a dosage form taking advantage of the properties of such a thickener. And a system containing an aqueous medium, such as a viscous solubilizing system in which is dispersed, and an emulsion system containing a small amount of oil. Among them, emulsion type foundations containing a small amount, for example, 5% by weight or less, of fats and oils and having a high powder content have not yet been obtained due to the problem of stability of the system. The invention has made such a system possible. In the cosmetic of the present invention, the coating powder may contain only one kind, or may contain two or more kinds in combination. The preferred content of the coating powder in the cosmetic of the present invention is from 1 to 30.
%, More preferably 5 to 20% by weight.
The cosmetic of the present invention can contain optional components usually used in cosmetics in addition to the coating powder, which are these essential components. Such optional components include, for example, hydrocarbons such as petrolatum and microcrystalline wax, esters such as jojoba oil and gay wax, tallow, triglycerides such as olive oil, cetanol,
Higher alcohols such as oleyl alcohol, fatty acids such as stearic acid and oleic acid, polyhydric alcohols such as glycerin and 1,3-butanediol, nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric interfaces Preferred examples include activators, thickeners such as ethanol and carbopol, preservatives, ultraviolet absorbers, antioxidants, and pigments.

[0011]

EXAMPLES The present invention will be described in detail with reference to examples below, but it goes without saying that the present invention is not limited only to these examples.

REFERENCE EXAMPLE Under a nitrogen stream, 200 parts by weight of methyl ethyl ketone were heated to reflux, and 62 parts by weight of α-methylstyrene, 10 parts by weight of 2-ethylhexyl acrylate, 28 parts by weight of acrylic acid, and azobisisobutyrate were used. 0.5 parts by weight of lonitrile was added dropwise and reacted for 4 hours. This was neutralized with aqueous ammonia and concentrated under reduced pressure to remove methyl ethyl ketone. To this solution, 188 parts by weight of styrene and 15 parts by weight of 2-ethylhexyl acrylate were added dropwise.
A solution prepared by dissolving 0.1 part by weight of potassium persulfate in parts by weight was added and reacted for 4 hours. Furthermore, it heated at 90 degreeC, and cooled, and obtained the core-shell type emulsion liquid (core-shell liquid 1). The dried residue was 72% by weight, which was taken as the resin content. Also, the core: shell = 67:
The resin had a weight ratio of 33.

<Example 1> A liquid having the following formulation was charged into a sand grind mill together with 30 parts by weight of zirconia beads and dispersed by a sand grind mill to obtain a coating powder dispersion 1 of the present invention. The dispersion state of the powder in this liquid was extremely good. In general, it can be seen that even the silicone-treated hydrophobized powder, which has extremely poor dispersibility in an aqueous system, can be well dispersed according to the technique of the present invention. Core shell liquid of reference example 1 10 parts by weight Silicone baked titanium dioxide 30 parts by weight Silicone baked yellow iron oxide 5 parts by weight Silicone baked bengara 2 parts by weight Silicone baked talc 13 parts by weight Water 40 parts by weight

Example 2 A liquid foundation was prepared using the coating powder dispersion 1. That is, the component (a) was thoroughly stirred and made uniform to obtain a liquid foundation. 1,3-butanediol 12.8 parts by weight Silica gel 0.6 parts by weight Spherical acrylic powder 0.2 parts by weight Coating powder dispersion 1 20 parts by weight Bentonite 0.7 parts by weight Sodium chloride 0.2 parts by weight Methyl paraben 0 2 parts by weight Ethanol 5 parts by weight Water 60.3 parts by weight

Example 3 A control liquid 1 was prepared by treating the resin of the coating powder dispersion liquid 1 of Example 1 with water instead of water.
Comparative solution 1 replaced with vinyl acetate liquid (resin content 65%) and treated in the same manner, polyvinyl alcohol liquid (resin content 70%)
And a comparative solution 2 treated in the same manner was prepared.
++: very good, +: good, ±:
Somewhat good,-: Observed on the bad criteria. Further, the dispersion was stored at 40 ° C. for 48 hours, and the dispersion stability was observed based on the degree of sedimentation of the powder. The criteria for the degree of sedimentation were ++: no sedimentation was observed, +: almost no sedimentation, ±: slight sedimentation was observed,-: clearly sedimented. Table 1 shows the results. This indicates that the coating powder of the present invention is excellent in dispersibility and dispersion stability.

[0016]

[Table 1]

<Example 4> Comparative foundations 1 and 2 and a control foundation 1 were prepared by using the comparative liquids 1 and 2 and the control liquid 1 of the example 3 and replacing the coating dispersion 1 of the example 2. The makeup effect was examined. The evaluation items of the cosmetic effect include: make-up, resistance to makeup loss due to friction in the presence of oil (oil resistance), resistance to makeup loss due to friction in the presence of water (water resistance),
The evaluation criteria were as follows: ++: very good, +: good, ±: slightly good,-: bad. Table 2 shows the results. From this, it can be seen that the foundation, which is the cosmetic of the present invention, is very excellent not only in stability but also in its cosmetic effect.

[0018]

[Table 2]

Example 5 A creamy foundation was prepared according to the following formulation. That is, the components (a) and (b) were each stirred to make them uniform, and (b) was gradually added and neutralized to obtain a creamy foundation. As well as the foundation of Example 2, this cosmetic is not only excellent in cosmetic effect, but also has excellent cosmetic effect, which is a feature of the cosmetic of the present invention, and also has excellent covering power.
The feeling of use was also refreshing and unprecedented. A Glycerin 5 parts by weight 1,3-butanediol 15 parts by weight Decamethylcyclopentasiloxane 1 part by weight Silica gel 2 parts by weight Coating powder dispersion 1 20 parts by weight Carboxyvinyl polymer 0.3 parts by weight Ethanol 2 parts by weight Methyl paraben 0. 2 parts by weight Water 40 parts by weight b Potassium hydroxide 0.3 part by weight Water 14.2 parts by weight

Example 6 A liquid having the following formulation was charged into a sand grind mill together with 30 parts by weight of zirconia beads and dispersed in a sand grind mill to obtain a coating powder dispersion 2 of the present invention. The dispersion state of the powder in this liquid was extremely good. In general, it can be seen that even the silicone-treated hydrophobized powder, which has extremely poor dispersibility in an aqueous system, can be well dispersed according to the technique of the present invention. Core shell liquid of reference example 1 10 parts by weight Water 40 parts by weight Zinc stearate-treated (10%) fine particle titanium dioxide 40 parts by weight Silicone-baked zinc oxide 10 parts by weight

Example 7 Sun care milk was prepared according to the following recipe. That is, (a), (b) and (c) were each heated to 80 ° C., (b) was gradually added to (b) for neutralization, and (c) was gradually added and emulsified, followed by stirring and cooling to obtain sun care milk. It had excellent durability of UV protection, despite its light feel. B. Acrylic acid / alkyl methacrylate (C10-30) 0.3 parts by weight 1,3-butanediol 5 parts by weight 0.2 parts by weight methyl paraben 0.25 parts by weight of coating powder dispersion 2 15 parts by weight Water 40 parts by weight b) Potassium hydroxide 0 3 parts by weight water 33.2 parts by weight c para-dimethylaminoisooctyl benzoate 5 parts by weight sorbitan monooleate 1 part by weight

Example 8 A liquid having the following formulation was charged into a sand grind mill together with 30 parts by weight of zirconia beads and dispersed in a sand grind mill to obtain a coating powder dispersion 3 of the present invention. The dispersion state of the powder in this liquid was extremely good. In general, it can be seen that even the silicone-treated hydrophobized powder, which has extremely poor dispersibility in an aqueous system, can be well dispersed according to the technique of the present invention. Core shell liquid of reference example 1 10 parts by weight Water 40 parts by weight Perfluoroalkyl-treated iron grate 50 parts by weight

Example 9 Mascara was prepared according to the following recipe. That is, the components (a), (b), and (c) are each heated to 80 ° C., and (d) is dispersed in (a). Was. It was a mascara that resisted breaking. Imokuro 5 parts by weight Solid paraffin 5 parts by weight Carnauba wax 5 parts by weight Microcrystalline wax 5 parts by weight Monoglyceride stearate 3 parts by weight Polyoxyethylene (20) behenyl ether 2 parts by weight b Coating powder dispersion 3 30 parts by weight 1 5, 3-butanediol 5 parts by weight Carboxyvinyl polymer 0.3 parts by weight Methyl paraben 0.2 parts by weight Water 20 parts by weight C potassium hydroxide 0.3 parts by weight Water 18.2 parts by weight d Nylon fiber 1 part by weight

[0024]

According to the present invention, it is possible to provide a powder-dispersed cosmetic having excellent stability in the presence of an aqueous medium.

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Claims (9)

[Claims] 1. A powder comprising an acrylic water-soluble polymer in an outer shell and a core-shell emulsion resin having a water-insoluble polymer in an inner core. 2. The acrylic water-soluble polymer of the outer shell comprises acrylic acid and a salt thereof, methacrylic acid and a salt thereof, acrylate ester, methacrylate ester, styrene and α.
The powder according to claim 1, characterized in that it contains one or more selected from alkylstyrene as a constituent monomer. 3. The acrylic water-soluble polymer of the outer shell comprises acrylic acid and a salt thereof, methacrylic acid and a salt thereof, acrylate, methacrylate, styrene and α.
The powder according to claim 1, wherein the powder is one or two or more polymers and / or copolymers selected from alkylstyrene. 4. The water-insoluble polymer of the inner core is styrene, α
The powder according to any one of claims 1 to 3, wherein the powder contains one or more selected from alkylstyrene, acrylic acid ester, and methacrylic acid ester as constituent monomers. 5. The water-insoluble polymer of the inner core is styrene, α
-One or more polymers and / or copolymers selected from alkylstyrenes, acrylates and methacrylates, characterized in that they are copolymers.
5. The powder according to any one of the above items 4. 6. The material according to claim 1, wherein a powder whose surface has been previously treated with hydrogen methyl polysiloxane, dimethyl polysiloxane and a silane coupling agent is used as the material to be coated. Powder. 7. A cosmetic containing the powder according to any one of claims 1 to 6. 8. The cosmetic according to claim 7, comprising a carboxyvinyl polymer and / or a salt thereof. 9. The cosmetic according to claim 7, which is of an aqueous medium dispersion type.