JPH09241129A - Composite powder material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite powder material useful for preparations for external uses for skins, etc., eliminated in the surface activity of a powder material and having temperature sensitivity by successively forming a specific silicone polymer film and a hydrophilic polymer coating film on the surface of the powder material. SOLUTION: This composite powder material is obtained by forming a coating film comprising a silicone polymer having Si-H portions on the surface of a powder material and further forming a hydrophilic polymer coating film on the formed coating film. The silicone monomer or oligomer convenient for the coating is preferably a compound of the formula (R<1> -R<3> are each H, a hydrocarbon; R<4> -R<6> are each H, a hydrocarbon; (a) is >=1; (b) is 0, a number of <10000, (c) is 0, 2, the maximum value of (a)+(b)+(c) is 10000; the compound contains at least one of SiH group portion). The powder material is obtained in three processes comprising (1) forming the coating film of a silicone polymer on a power material, (2) reacting the Si-H portions of the silicone polymer with a reactive group-containing unsaturated compound and (3) forming a hydrophilic polymer coating film on the powder material through the obtained reactive groups. A polyacrylamide is preferably used for the hydrophilic polymer coating film.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is easy to manufacture,
Moreover, the present invention relates to a highly stable, highly hydrophilic and temperature-sensitive composite powder and a method for producing the same.

[0002]

2. Description of the Related Art Powder-type or cake-type powder cosmetics such as foundations, eye colors, and cheek colors generally have powder surfaces such as extender pigments, white pigments, and colored pigments Prepared by compressing and solidifying by treating with a binder such as an oil agent or a surfactant, but absorbs sweat and sebum due to the hygroscopicity and oil absorption of the powder, and time elapses after applying the cosmetic to the skin As a result, dull colors and discoloration of makeup occur. Therefore, hydrophilic powder is treated with a hydrophobizing agent such as silicone oil or a surfactant to improve water repellency, or it is coated with a fluororesin to improve water repellency and oil repellency, thus maintaining makeup retention. Attempts were made to improve it.

On the other hand, in powder cosmetics, water is not mixed, or even if it is mixed, the amount is limited to a very small amount, so that an emollient is contained and substances having high water retention such as collagen, hyaluronic acid and amino acid derivatives are included. Attempts have been made to give powder cosmetics moisturizing properties by mixing powders coated with.

However, the conventional cosmetics containing the water-repellent powder are suppressed in hygroscopicity of the powder itself when used in the summer when the temperature is high and the humidity is high, and the resistance to sweat is large, and the repellency is further improved. When oily powder is blended, resistance to sebum is also imparted and a good feeling of use is exhibited.
When used in winter when the temperature is low and the air is dry, the hygroscopicity of the powder is low, and the feeling of dryness becomes strong and a proper feeling of use cannot be obtained. On the other hand, cosmetics containing water-retaining powder have a moisturizing feel under conditions of low temperature and low humidity, but in the summer when the temperature and humidity are high and sweat is likely to occur, a sticky feeling is caused and makeup loss is remarkable. Becomes

Therefore, in summer when the temperature and humidity are high, and in winter when the temperature is low and the humidity is low and the skin tends to be dry, the cosmetic has a satisfactory feeling of use over both seasons. As a new temperature-sensitive powder whose hydrophilicity decreases in the summer and shows water repellency, and hydrophilicity increases in the low temperature and low humidity in the winter to retain water, the surface of the powder is coated with an acrylic acid polymer. Has been developed (Japanese Patent Laid-Open No. 7-285828). However, in this composite powder, the surface activity of the powder remains,
In addition to being inadequate in terms of stability, there is also a drawback in that it is necessary to manufacture and purify a polymer for forming a film, resulting in high manufacturing cost.

[0006]

As a result of intensive studies, the present inventors have found that if a silicone polymer film and a hydrophilic polymer film are sequentially formed on the surface of a powder, the surface activity of the powder will be reduced. It was found that the composite powder having the above-mentioned properties disappeared and having temperature sensitivity was obtained, and the present invention was completed. Further, according to the method of the present invention, a composite powder in which the silicone polymer film and the hydrophilic polymer film are firmly formed on the powder surface can be obtained by a simple method.

That is, according to the present invention, Si--H is formed on the powder surface.
The composite powder is characterized in that a film made of a silicone polymer having at least one portion is formed by coating, and a hydrophilic polymer film is further formed by coating on the outer layer thereof.

Further, the manufacturing method is such that Si is formed on the powder surface.
The first step of forming a coating of a silicone polymer having at least one -H portion, and the reactive group-containing unsaturated compound and the Si-H portion of the silicone polymer are subjected to an addition reaction to make the powder surface hydrophilic. A second step of forming a reaction point with the hydrophilic polymer, and a third step of forming a hydrophilic polymer film in which the hydrophilic polymer is bound via the reactive group on the outermost layer. It is characterized by

Further, according to the present invention, Si-
There is provided an external skin preparation containing a composite powder in which a film made of a silicone polymer having at least one H portion is formed by coating, and a hydrophilic polymer film is formed by coating the outer layer of the silicone polymer.

The composite powder of the present invention and the method for producing the same will be specifically described below. Regarding the type of powder used in the present invention, for example, in the case of inorganic powder, sericite,
Examples include extender pigment powders such as talc, mica, silica, kaolin, zinc oxide, titanium oxide, metal oxides such as ultramarine, and organic powders such as nylon powder.
It goes without saying that the scope of the invention is not limited to these examples.

A method for treating a powder of a silicone polymer coated powder used in the present invention with a silicone is known per se. For example, a method of coating with a silicone polymer is disclosed in Japanese Patent Application Laid-Open No. 63-113081 related to the prior application of the present inventors. Those specifically described in the publication can be mentioned.
The silicone polymer to be coated is preferably, for example, a silicone monomer or oligomer which is a precursor of the silicone polymer is adsorbed on the powder and polymerized on the surface thereof to form a uniform silicone polymer coating. Silicone compounds of general formula (1) can be used as convenient silicone monomers or oligomers for this coating.

[0012]

(R ¹ HSiO) _a (R ² R ³ SiO) _b (R ⁴ R ⁵ R ⁶ SiO _1/2 ) _c (1)

(Wherein R ¹ , R ² and R ³ are, independently of each other, a hydrogen atom or a halogen atom of at least 1
Hydrocarbon groups having 1 to 10 carbon atoms which may be substituted with R ¹ , R ² and R ³ are not hydrogen atoms at the same time, and R ⁴ , R ⁵ and R ^{6 s} independently of each other are a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may be substituted with at least one halogen atom, a is an integer of 1 or more, and b is It is 0 or an integer less than 10,000. c is 0
Or 2, but when c is 0 then a + b
Is an integer of 3 or more, and the maximum value of a + b + c is 10000.
At least one H portion is included. In the general formula (1), the groups R ^{1 to} R ⁶ can be different from each other in each repeating unit. Specific examples include compounds represented by the following formulas (2), (3), (4) and (5).

[0014]

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(In the formula, R ¹ is a lower alkyl group such as a methyl group or an ethyl group, or an aryl group such as a phenyl group, and a = 3 to 7.)

[0016]

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(In the formula, R ¹ and R ² are a lower alkyl group or an aryl group, R ³ is an alkyl group or an aryl group, and a + b is 3 to 100.)

[0018]

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(In the formula, a is preferably 1 to 500, particularly preferably 2 to 5.)

[0020]

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(Where a + b is 1 to 500, and a ≧
2. In addition, it is also possible to use one in which one or more methyl groups in the general formulas (4) and (5) are replaced with one or more ethyl groups, propyl groups or phenyl groups.

Examples of such compounds include dihydrogen hexamethylcyclotetrasiloxane, trihydrogen pentamethylcyclotetrasiloxane, tetrahydrogen tetramethylcyclotetrasiloxane, dihydrogen octamethylcyclopentasiloxane and tetrahydro. Cyclic silicone compounds such as genhexamethylcyclopentasiloxane and pentahydrogenpentamethylcyclopentasiloxane and 1,1,1,3,5,7,7,7-octamethyltetrasiloxane, 1,1,1,3 5, 7, 9,
9,9-Nonamethylpentasiloxane and 1,1,
Mention may be made of linear silicone compounds such as 1,3,5,7,9,11,11,11-decamethylhexasiloxane. These silicone compounds can form a silicone polymer coating deposited on the solid surface, for example by polymerization on the solid surface as disclosed in the above-mentioned publication. This polymer has reactive hydrosilyl (Si-H) groups as can be seen from the general formula of its corresponding monomer or oligomer.

The contact and polymerization of the powder with the silicone compound are most preferably carried out by a gas phase treatment, but the silicone compound is dissolved in a solvent to disperse the powder and then dried to form a silicone polymer coating on the surface of the powder. Alternatively, a silicone compound dissolved in a solvent may be directly sprayed and dried by heating to form a silicone polymer film. If the treatment is dried, a silicone polymer coating is formed on the surface, and by itself, a stable powder is obtained. In the case of gas phase treatment, even a drying step is unnecessary. For example, the powder is loaded into an appropriate mixer (rotary ball mill, vibrating ball mill, planetary ball mill, sand mill, attritor, pug mill, poni mixer, planetary mixer, crusher), etc. and processed mechanochemically. It is carried out by

Next, the hydrophilic polymer film formed on the silicone polymer film will be described. As the hydrophilic polymer used in the present invention, polyacrylamides and polyalkylene glycols are preferable. Among them, polyacrylamides include polyacrylamide, poly N-methyl acrylamide, poly N-ethyl acrylamide, poly N-isopropyl acrylamide,
Poly N-cyclopropyl acrylamide, poly N-n-
Propyl acrylamide, poly N-t-butyl acrylamide, poly methacrylamide, poly NN-dimethyl acrylamide, poly NN-diethyl acrylamide, poly NN-diisopropyl acrylamide, poly NN-di-n-propyl acrylamide, poly N-methyl-N-
Examples thereof include ethyl acrylamide, poly N-ethyl-N-isopropyl acrylamide, poly N-ethyl-Nn-propyl acrylamide, poly N-isopropyl-N-n-propyl acrylamide and the like. Polyalkylene glycols include polyethylene glycol,
Examples include polypropylene glycol and polybutylene glycol. In addition, poly N-acryloyl pyrrolidine, poly N-acryloyl piperidine, poly N-acryloyl methyl homopiperazine, poly N-acryloyl methyl piperazine, etc. may be used.

Next, a method for forming the hydrophilic polymer film will be described. The hydrophilic polymer film formed on the silicone polymer film can be formed on the silicone polymer film by using the reactive group-containing unsaturated compound as an adhesive for bonding both films. Here, the term "reactive group" means a group having reactivity with a hydrophilic polymer or a monomer as a raw material thereof, and is a portion where a reaction point with a hydrophilic polymer film is formed as a result. Examples of the reactive group-containing unsaturated compound include unsaturated compounds having a hydroxyl group. Examples of the compound having one hydroxyl group include allyl alcohol and 3-butenyl alcohol. Examples of the compound having two hydroxyl groups include glycerol-α-monoallyl ether.

Next, a method of reacting the surface of the silicone-coated powder with the unsaturated compound containing a reactive group will be described. First,
The above compound is dissolved in an organic solvent, and a silicone-coated powder is added, and the mixture is stirred and well dispersed, followed by hydrosilylation reaction (a catalyst such as chloroplatinic acid may be used).
To add the compound. The treatment temperature is not particularly limited as long as it is not higher than the boiling point of the organic solvent. The organic solvent used for the reaction between the surface of the silicone-coated powder and the unsaturated compound containing a reactive group may be any solvent such as acetone, ethanol or toluene, as long as it can dissolve the unsaturated compound. If necessary, two or more kinds of organic solvents may be used in combination.

The formation of the hydrophilic polymer film on the powder having the reactive group obtained on the surface as described above is carried out as follows.
Finally, the target powder is obtained by putting the powder and a hydrophilic monomer (eg acrylamide) in an organic solvent and further graft-polymerizing them in the presence of a polymerization initiator (eg heavy metal ions such as Ce). You can The organic solvent used at this time may be any solvent such as acetone, ethanol or toluene, as long as it can dissolve the hydrophilic monomer. If necessary, two or more kinds of organic solvents may be used in combination. Thus, the composite powder of the present invention is obtained. The powder according to the present invention is a skin external preparation, paint, container, plastic, paper, fiber, sheet, glass,
It can be used for prisms, lenses, etc.

When the composite powder of the present invention is used as an external preparation for skin, especially as a powder for cosmetics, it is satisfactory over both seasons, in the summer when the temperature is high and the humidity is high, and in the winter when the temperature is low and the humidity is low and the skin is easy to dry. It is possible to obtain a cosmetic having a good feeling of use and high stability. The external preparation for skin containing the composite powder of the present invention includes other powders, oils, preservatives, antioxidants,
Drugs, fragrances, UV absorbers, surfactants, semi-solid oil,
Ingredients that are usually blended in external preparations for skin such as solid oil and moisturizer can be added.

[0029]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but it goes without saying that the scope of the present invention is not limited to these examples. Example 1 (1-1) Silicone Polymer Coating of Fine Particle Silica Gel A particle size of 5 in a rotary double-cone type reaction vessel (stainless steel, with a heat insulation jacket) having a volume of 100 liters.
4 kg of 0 nm silica gel was added. The temperature of the reaction tank and the processing liquid supply tank (stainless steel, with a heat insulation jacket) directly connected to it with a volume of 10 liters, the heat medium heated to 80 ° C. is supplied from the heat medium heating tank to each heat insulation jacket by a circulation pump. By doing, 80 ℃
Held. Nitrogen gas was supplied to the treatment liquid supply tank at 1.5 l / min to bubble the treatment liquid (1,3,5,7-tetramethylcyclotetrasiloxane). A condenser was attached to the reaction tank so that nitrogen gas was released from the condenser and unreacted treating agent could be recovered. Further, the reaction tank was rotated at 10-minute intervals for 1 minute, and the operation of mixing the fine particle silica gel in the reaction tank was repeated for 8 hours to take out the treated powder. The powder obtained showed a marked hydrophobicity.

(1-2) Surface Modification of Silicone Polymer-Coated Fine Particle Silica Gel 100 g of the silicone polymer-coated fine particle silica gel of (1-1) was placed in a 3-liter eggplant-shaped flask, and 10 mg of chloroplatinic acid and glycerol-α were used as a catalyst. -4 g of monoallyl ether and 0.5 liter of ethanol were added, and the mixture was heated under reflux in a mantle heater for 6 hours, filtered, washed with 2 liters of ethanol, degassed and dried, and then with glycerol-α-monoallyl ether. A surface-modified powder was obtained.

(1-3) Coating of Polyacrylamide onto Glycerol-α-Monoallyl Ether Modified Powder A 100 mL eggplant-shaped flask containing a stirrer bar was added to
0.5 g of the modified powder of (1-2) and 1.0 of acrylamide
Then, 9 mL of a polymerization solvent (a mixed solvent of degassed pure water and acetone (volume ratio 10: 3)) was added. An aqueous nitric acid solution of ceric ammonium cerium nitrate (1 mol / L nitric acid aqueous solution 1.09 g of ceric ammonium ceric nitrate 1
1.0 mL of a solution containing 0 mL) was quickly added and the vessel was sealed, and polymerization was carried out at 30 ° C. under a nitrogen atmosphere while stirring with a magnetic stirrer. After the reaction, the product was poured into a large amount of acetone to stop the polymerization, and the polymer containing the modified powder was precipitated. The precipitate was suction filtered and washed well with acetone. The product was infrared-dried and then dried under reduced pressure to obtain a target composite powder.

Example 2 The same treatment as in Example 1 was carried out except that the fine particle silica gel of Example 1 was replaced with fine particle titanium dioxide to obtain a composite powder. The amount of polyacrylamide grafted on the surface of the particles was 0.28 mg / m ² per 1 m ² of surface area of titanium dioxide, and the polymerization rate was 70% by weight. The IR spectrum of the obtained composite powder is shown in FIG. 1 (A), and the IR spectrum of the surface-modified silicone polymer-coated fine particle titanium dioxide is shown in FIG. 1 (B). In FIG. 1A, clear peaks derived from Si—CH ₃ derived from a silicone polymer and C═O of polyacrylamide are observed, which indicates that a composite powder is formed.

Example 3 A composite powder was obtained by carrying out the same treatment as in Example 1 except that 10 kg of sericite was used instead of the fine particle silica gel of Example 1.

Example 4 A composite powder was obtained in the same manner as in Example 1, except that the fine particle silica gel of Example 1 was replaced with 10 kg of talc.

Example 5 A composite powder was obtained by carrying out the same treatment as in Example 1 except that the fine particle silica gel of Example 1 was changed to 10 kg of zinc white.

Example 6 A composite powder was obtained by performing the same treatment as in Example 1 except that 10 kg of mica titanium was used instead of the fine particle silica gel of Example 1.

Example 7 The acrylamide in (1-3) of Example 1 was replaced with N, N.
-The same treatment as in Example 1 was performed except that diethyl acrylamide was used to obtain a composite powder.

Example 8 A composite powder was obtained by performing the same treatment as in Example 1 except that the particulate silica gel of Example 1 was replaced with particulate titanium dioxide and the acrylamide was replaced with N, N-diisopropylacrylamide.

Example 9 A composite powder was obtained in the same manner as in Example 1 except that the fine particle silica gel of Example 1 was replaced with 10 kg of sericite and the acrylamide was replaced with N-ethyl-N-isopropylacrylamide. .

Example 10 A composite powder was obtained by performing the same treatment as in Example 1 except that the particulate silica gel of Example 1 was replaced with particulate titanium dioxide and the acrylamide was replaced with N, N-diethylacrylamide. The IR spectrum of the obtained composite powder is shown in FIG. 2 (A), and the IR spectrum of the surface-modified silicone polymer-coated particulate titanium dioxide is shown in FIG. 2 (B).
In FIG. 2A, Si-C derived from a silicone polymer is used.
Since clear peaks derived from C = O of H ₃ and polyacrylamide are observed, it can be seen that the composite powder is formed.

Example 11 A composite powder was obtained in the same manner as in Example 1, except that the particulate silica gel of Example 1 was replaced with particulate titanium dioxide and the acrylamide was replaced with N-isopropylacrylamide. The IR spectrum of the obtained composite powder is shown in FIG. 3 (A), and the IR spectrum of the surface-modified silicone polymer-coated fine particle titanium dioxide is shown in FIG. 3 (B).
In FIG. 3A, Si-C derived from a silicone polymer is used.
Since clear peaks derived from C = O of H ₃ and polyacrylamide are observed, it can be seen that the composite powder is formed.

Test Example 1: Wettability test Acrylamide / glycerol-α obtained in Example 2
-Monoallyl ether modified titanium dioxide (A), glycerol-α-monoallyl ether modified titanium dioxide (B), and untreated titanium dioxide (C) were each packed in a column having an inner diameter of 5 mm, and water was added from above. In addition, permeation (wet) distance (mm) of the packed bed by absorbing water absorbed for 1 minute
Was compared. As a result, in (C), the permeation rate of water is 1
mm / min, and the surface hydrophilicity was small. Also,
In (B), almost no water permeation was observed, and the particle surface was hydrophobic. On the other hand, in (A), the water permeation rate was 5 mm / min, which was higher than that of glycerol-α-monoallyl ether-modified titanium dioxide (B) and untreated titanium dioxide (C). It was found that the hydrophilicity of the surface of the composite powder of the invention was remarkably improved.

Test Example 2: Temperature Sensitivity Test The composite powder obtained in Example 8 was treated with deionized water (20 ° C.).
And then immersed in warm water (40 ° C. or higher). As a result, the composite powder that had been dispersed until then gradually aggregated and settled. Next, when it was immersed in cold water, it was well dispersed again, and it was confirmed that it showed temperature sensitivity.

Next, examples of various skin external preparations containing the composite powder according to the present invention will be described. No skin irritation or allergenicity was observed in any of the external preparations for skin of each Example, and the safety to the skin was extremely high.

Example 12 Foundation (1) Composite Powder of Example 3 10.0% by Weight (2) Titanium Dioxide 13.0 (3) Colloidal Kaolin 25.0 (4) Talc 34.7 (5) Bengalla 1 0.0 (6) Yellow iron oxide 2.5 (7) Black iron oxide 0.1 (8) Liquid paraffin 8.0 (9) Sorbitan sesquioleate 3.5 (10) Glycerin 2.0 (11) Ethylparaben 0.2 (Production method) (1) to (7) are mixed and passed through a crusher to obtain an average particle size of 1
Grinded to ~ 5 μm. Transfer this to a high speed blender, (1
0) was added and mixed. Separately, (8), (9) and (11) were mixed, and the homogenized mixture was added to the above mixture and further homogeneously mixed. This was processed with a crusher, the particle size was adjusted through a sieve, and then compression molding was performed to obtain a cake type foundation.

Example 13 Emulsion Foundation (A) Ion-exchanged water 43.5% by weight Sodium chondroitin sulfate 1.0 Sodium lactate 0.5 1,3-butylene glycol 3.0 Methylparaben Appropriate amount (B) Dimethylpolysiloxane (20 cs) 16.0 Decamethylcyclopentasiloxane 5.0 Silicone resin 1.0 Cetylisooctanate 1.0 Polyoxyalkylene modified organosiloxane (modification rate 20%) 4.0 Antioxidant proper amount Perfume proper amount (C) Yellow iron oxide 1.0 Red iron oxide 0.45 Black iron oxide 0.2 Composite powder of Example 11.7 Composite powder of Example 9 11.65 (Production method) After heating and dissolving the component (B), the component (C) ) Powder is added and dispersed. Further, the component (A) previously dissolved and heated was added and emulsified, and cooled to room temperature to obtain an emulsified foundation. It was found that the obtained emulsified foundation had improved makeup retention.

Example 14 Presto Powder (1) Composite Powder of Example 6 30.0% by Weight (2) Composite Powder of Example 4 65.8 (3) Iron Oxide Pigment 0.1 (4) Squalane 2 0.0 (5) 2-Ethylhexyl palmitate 2.0 (6) Perfume 0.1 (Production method) (1), (2) and (3) were mixed with a Henschel mixer, and this was mixed with (4) and (5). What was heated and mixed was sprayed, and after mixing, it was crushed and molded into a medium dish to obtain a pressed powder.

Example 15 Lipstick (1) Hydrocarbon wax 3.0% by weight (2) Carnauba wax 1.0 (3) Glyceryl isostearate 40.0 (4) Liquid paraffin 45.8 (5) Example 1 Composite powder 4.0 (6) Mixed powder of iron oxide and sericite 6.0 (7) Perfume 0.2 (Production method) (1) to (4) are melted at 85 ° C, and then (5) And (6) were added with stirring. Finally, (7) was added under stirring. The resulting mixture was charged into a container. The desired lipstick with excellent dispersibility was thus obtained.

Comparative Example 1 Lipstick (1) Hydrocarbon wax 3.0 wt% (2) Carnauba wax 1.0 (3) Glyceryl isostearate 40.0 (4) Liquid paraffin 45.8 (5) Composite powder 4 0.0 (fine silica gel directly modified with polyacrylamide) (6) Mixed powder of iron oxide and sericite 6.0 (7) Perfume 0.2 (Production method) (1) to (4) at 85 ° C It melt | dissolved, and (5) and (6) were added in it, stirring. Finally, (7) was added under stirring. The resulting mixture was charged into a container. Thus the desired lipstick was obtained. The composite powder is described in JP-A-7-28.
It was manufactured by the method described in Japanese Patent No. 5828.

Test Example 3: Stability test over time 5 times each of the lipsticks obtained in Example 15 and Comparative Example 1
Stored at 0 ° C for -1 month. As a result, Example 15 was stable with no change, whereas Comparative Example 1 had an offensive odor which is considered to be due to decomposition of the fragrance.

[0051]

As described above, the composite powder of the present invention is a highly stable, highly hydrophilic and temperature-sensitive composite powder, and according to the production method of the present invention, such composite powder Can be easily mass-produced and the manufacturing cost is low.

[Brief description of drawings]

FIG. 1 is an IR spectrum diagram of an example of a composite powder according to the present invention.

FIG. 2 is an IR spectrum diagram of an example of the composite powder according to the present invention.

FIG. 3 is an IR spectrum diagram of an example of the composite powder according to the present invention.

Claims (7)

[Claims] 1. A powder surface having at least one Si--H portion.
A composite powder comprising a coating of a silicone polymer having a plurality of coatings, and a hydrophilic polymer coating formed on the outer layer of the coating. 2. The composite powder according to claim 1, wherein the hydrophilic polymer film is made of polyacrylamide or its derivative, or polyalkylene glycol. 3. A first step of forming a coating of a silicone polymer having at least one Si—H portion on the surface of the powder, a reactive group-containing unsaturated compound and the Si—H portion of the silicone polymer. And the second step of forming a reaction point with the hydrophilic polymer on the surface of the powder by an addition reaction with, and a hydrophilic polymer film in which the hydrophilic polymer is bound via the reactive group as the outermost layer. And a third step of forming a coating. 4. The method for producing a composite powder according to claim 3, wherein the reactive group that is a reaction point with the hydrophilic polymer compound is a hydroxyl group. 5. The third step of coating and forming a hydrophilic polymer film comprises graft-polymerizing a hydrophilic monomer in the presence of a powder having reactive points.
Alternatively, the method for producing the composite powder as described in 4 above. 6. The method for producing a composite powder according to claim 3, wherein the hydrophilic polymer film is made of polyacrylamide or its derivative, or polyalkylene glycol. 7. An external preparation for skin comprising the composite powder according to claim 1 or 2.