JP4999412B2 - Fine particle powder and method for producing the same - Google Patents

Description

  The present invention relates to a fine particle powder composed of a fine particle metal oxide or a hydroxide / fatty acid complex, a method for producing the same, and a skin external preparation containing it, which are suitable as a cosmetic raw material.

Most inorganic particles such as pigments are produced in an aqueous system and are inherently hydrophilic and partly oleophilic. However, inorganic particles produced by water-based reactions begin to grow from the moment they are produced and cannot be extracted as ultrafine particles. In addition, in water, the particles tend to agglomerate with each other due to their polarity, making redispersibility difficult. A good dispersion. Such difficulty of dispersibility can be said to be similarly difficult or even higher if the dispersion medium is replaced with an organic solvent or oil. This is because it is difficult for such an organic dispersion medium to break the bond between powders more than water. In order to facilitate subsequent handling, once dried and powdered, the surface of the particles is activated and the particles are connected with a very strong cohesive force. Furthermore, the dispersibility in water and organic dispersion media is It becomes more difficult. On the other hand, the use of dispersed inorganic particles such as pigments is infinitely equal to paints, paints, cosmetics, foodstuffs, inks, etc. In recent years, inorganic particles used in these applications have become increasingly sophisticated in equipment and usage. With the refinement, finer and more dispersible materials have been demanded, and accordingly, finer pigments have been actively studied. However, in the above-described example, very strong crushing force is required to make inorganic particles fine particles and disperse them in a dispersion medium, and a large amount of surfactant is used to suppress dispersion and subsequent reaggregation. Ru required der (e.g., see Patent Document 1). In particular, when an organic dispersion medium is selected, there is a high probability that the dispersion medium itself has a high viscosity, and the mechanical force and the amount of surfactant required for dispersion are required to be larger. In this case, the fineness of the particles is naturally limited, and the use is limited depending on the type and amount of the active agent. That is, it can be said that there has been a demand for fine metal oxides or hydroxides that are excellent in dispersibility, in particular, dispersibility in organic dispersion media.

  In order to improve the dispersibility with respect to the organic dispersion medium, usually, a method of crushing the hydrophilic portion by a lipophilic treatment on the surface is taken, but as the lipophilic treatment, for example, a metal soap coating treatment, There are hydrogenmethylpolysiloxane baking treatment, phospholipid coating treatment, polyethylene coating treatment, acylamino acid salt coating treatment, etc., all of which require a heating process that promotes aggregation, or coating treatment with a component that becomes a binder Therefore, even if the particle size increases significantly, it does not decrease. In other words, it can be said that the higher the dispersibility in the organic dispersion medium, the larger the particle size, and the farther from dispersion of the dispersion into fine particles.

  As a complex of a fatty acid and a metal oxide or hydroxide, a mere metal soap, or a metal oxide or hydroxide treated with the metal soap is known (for example, Patent Document 2, (See Patent Document 3 and Patent Document 4), but of course, these are not sizes that can be said to be fine particles, and the permissible configuration of fatty acids does not match that of 6 to 30 carbon atoms. The fine particles referred to in the present invention mean particles having an average particle size of 0.1 μm or less.

  There are no known fine metal oxides or hydroxide / fatty acid complexes, and metal salts and alkalis are reacted in the presence of fatty acids and / or their salts to form metal oxides or hydroxides and fatty acids. There is also no known method for producing a fine particle metal oxide or hydroxide / fatty acid complex, which includes a step of forming a complex with the product, washing a product other than the complex, and then drying the product. .

  On the other hand, from the viewpoint of shape, most of the metal oxides or hydroxides of fine particles that have been known so far are spherical or indefinite, and the optical effect depends on the difference in shape. Therefore, the development of metal oxides or hydroxides having a characteristic shape has been desired. (For example, refer to Patent Document 5, Patent Document 6, Patent Document 7, and Patent Document 8) Among them, a scaly layer is not yet known.

JP 2001-207060 A Japanese Patent Laid-Open No. 08-231374 Japanese Patent Laid-Open No. 08-231373 JP 2000-219607 A JP 2005-289932 A Japanese Patent Application Laid-Open No. 07-155731 JP 2002-146238 A JP 2005-272466 A

  The present invention has been made under such circumstances, and an object of the present invention is to provide a metal oxide or hydroxide composition in the form of fine particles excellent in dispersibility in an organic dispersion medium.

  In view of such a situation, the present inventors sought for a composition of metal oxide or hydroxide in the form of fine particles excellent in dispersibility in an organic dispersion medium, and as a result of earnest research efforts, In the presence of a fatty acid and / or a salt thereof, a metal salt and an alkali are reacted to form a complex of the metal oxide or hydroxide and the fatty acid, and then a product other than the complex is washed. Then, it was found that the fine particle metal oxide or hydroxide / fatty acid complex obtained through the drying step has such characteristics, and the present invention has been completed. That is, the present invention is as follows.

(1) in water and an organic solvent and a mixed solvent, the presence of a fatty acid is reacted with a metal salt and an alkali, a metal oxide, allowed formation of a complex with a fatty acid, other than the complex thereafter A method for producing a fine particle metal oxide / fatty acid complex, comprising a step of removing a product by washing and then drying.
(2) said particulate metal oxide-fatty acid Rukin genus oxide put into the complex is characterized in that it is a zinc oxide, manufacturing method described in (1).
(3), wherein the fatty acid is a fatty acid having 6 to 30 carbon atoms, manufacturing method described in (1) or (2).
(4) The method according to any one of (1) to (3), wherein the metal salt is zinc chloride .
(5) The production method according to any one of (1) to (4), wherein the fine particle metal oxide / fatty acid complex has a scale-laminated shape.
(6) A fine particle metal oxide / fatty acid complex produced by the production method according to any one of claims 1 to 5 .
(7) A skin external preparation comprising the particulate metal oxide / fatty acid complex according to (6).
(8) The external preparation for skin according to (7), which is a cosmetic.

  ADVANTAGE OF THE INVENTION According to this invention, the composition of the metal oxide thru | or hydroxide of the fine particle form which is excellent in the dispersibility in an organic dispersion medium can be provided.

  The fine metal oxide or hydroxide / fatty acid complex of the present invention contains a water-soluble metal salt, for example, a halide such as chloride, nitrate, etc. in an aqueous carrier, and the presence of fatty acid and / or salt thereof. Then, it is produced by neutralizing with a water-soluble base and ion-exchanging the anion residue of the metal salt with the hydroxide ion. Examples of the metal constituting the metal oxide or hydroxide include zinc, iron, aluminum, magnesium, titanium, barium, manganese, cerium, cobalt, calcium, cadmium, strontium, copper, chromium, zirconium, gold, Silver and the like can be exemplified, and among these, those belonging to the amphoteric metal are preferable, and zinc, aluminum and the like can be suitably exemplified. In particular, zinc is particularly preferable because of optical effects. These metal salts can be used alone or in the form of a composite metal oxide or hydroxide using two or more kinds. The fatty acid and / or salt thereof is not particularly limited as long as it has 6 to 30 carbon atoms, more preferably 6 to 12 carbon atoms or a salt thereof, and may have an unsaturated bond. However, it may have a branched structure or a ring structure. In addition, the salt is not particularly limited as long as it has been used in cosmetics. For example, alkali metal salts such as sodium salts and potassium salts, alkaline earth metals such as calcium salts and magnesium salts. Preferred examples include organic amine salts such as salts, ammonium salts, triethylamine salts, triethanolamine salts and monoethanolamine salts, and basic amino acid salts such as lysine salts and alginates. Particularly preferred are alkali metal salts, especially sodium salts. Specifically, caproic acid, caprylic acid, capric acid, lauric acid, cyclohexane acid, 2-ethylhexanoic acid and the like can be suitably exemplified as fatty acids, and as salts thereof, sodium caproate, sodium caprylate, caprin Preferred examples include sodium acid, sodium laurate, sodium cyclohexane, sodium 2-ethylhexanoate and the like. Particularly preferred is caprylic acid or a salt thereof, and sodium caprylate is particularly preferred. The mass of the metal salt and the fatty acid or salt thereof is such that the metal oxide is converted to a metal oxide or hydroxide, and the metal oxide or hydroxide is 60% by mass or more. More preferably, it is preferably 60% to 99%, and more preferably 85% to 99%. It is essential that the aqueous carrier contains water, and it is preferable to use a mixture of water and a soluble organic solvent. In general, it is known that when a small amount or a large amount of an organic solvent is mixed in a process of hydrolyzing a metal salt in an aqueous system to produce a hydroxide or oxide, the hydrolyzate of the metal salt becomes an oxide. ing. The water-soluble organic solvent used in the production method of the present invention is used for directing the hydrolyzate of the metal salt directly to the oxide, and almost any organic solvent miscible with water can be used. Examples of such organic solvents include alcohols such as methanol, ethanol and isopropanol, diols such as ethanediol, propanediol and butanediol, ketones such as acetone, furans such as tetrahydrofuran, and a molecular weight of 200 or less. And ethylene glycol monoethers such as methoxyethanol and ethoxyethanol. The mixing ratio of such a water-soluble organic solvent is generally in a range of 1: 9 to 9: 1 by weight of water: water-soluble organic solvent. After completion of the reaction, it is preferable to remove excess salt by washing with hydrous alcohol or the like. In addition, as a base for generating a metal oxide or hydroxide, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide can be preferably exemplified, and the amount of such base added is the same as that of a metal salt or the like. A slight or excessive amount is preferred. Thus, a complex of a metal oxide or hydroxide and a fatty acid or a salt thereof obtained by reacting a fatty acid or a salt thereof, a water-soluble metal salt and a base in an aqueous carrier, Precipitate by centrifugation. Such precipitation can be removed once or several times with an aqueous carrier containing the organic solvent to remove unnecessary reaction products. After such treatment, the precipitate is dried to obtain a complex of the fine metal oxide and fatty acid or salt thereof of the present invention. Drying is performed by air drying for about 1 to 24 hours under heating at 30 to 100 ° C. Thus, a composite of fine particles is obtained in the form of a scale layer. Since such a complex is complexed with a fatty acid, the surface has high lipophilicity, and even this complex alone is excellent in the action of being uniformly dispersed in an oily carrier. Moreover, since it is a scale multi-layered form, it has an excellent covering power for the appearance that it feels thin. Since it is also excellent in UV protection effect, it is suitable as a raw material for UV protection cosmetics that do not feel white. Such a composite can be burned at 500 to 1000 ° C. in an oxidizing atmosphere to burn out the fatty acid, thereby forming a scale-layered metal oxide. In addition, the metal oxide or hydroxide / fatty acid complex of the present invention has the effects of the present invention other than the above components, that is, unless it has a lipophilic surface and does not impair that it is fine particles, silica, Optional ingredients such as fatty acid soaps and inorganic salts such as sodium chloride can also be contained. These contents are preferably suppressed to 10% by mass or less of the total amount of the composite.

The skin external preparation of the present invention contains the metal oxide or hydroxide / fatty acid complex of the present invention. The total content of the metal oxide or hydroxide / fatty acid complex in the external preparation for skin of the present invention is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass. The amount varies depending on the dosage form and type of the external preparation for skin, but in the above range, the finish does not feel unnatural whiteness, is not thick, the finish is natural, and is excellent. Also has UV protection effect. The skin external preparation of the present invention can be applied without particular limitation as long as it is a commonly known powder-containing skin external preparation, for example, UV protection cosmetics such as sun care milk, sun care powder, sun block, and undermake. Suitable examples include makeup cosmetics such as up, foundation, control color, and pressed powder, especially summer makeup cosmetics. As the dosage form, those containing an oily component are preferable. Particularly, in the case of using a paste as an intermediate work-in-process, it is preferable to incorporate it in the paste. This is because the dispersion stability in the paste is excellent. Furthermore, when it is contained in a foundation or the like, there is a secondary effect that there is little change with time in the color after application, and the cosmetic durability is excellent.

In the external preparation for skin of the present invention, in addition to the complex of the present invention, an optional component usually used in external preparations for skin can be contained. Examples of such optional components, e.g., macadamia nut oil, Abou transient oil, corn oil, olive oil, rapeseed oil, sesame oil, castor oil, safflower oil, cottonseed oil, jojoba oil, coconut oil, palm oil, liquid lanolin, cured Oils such as coconut oil, hydrogenated oil, molasses, hydrogenated castor oil, beeswax, candelilla wax, carnauba wax, ibotarou, lanolin, reduced lanolin, hard lanolin, jojoba wax, liquid paraffin, squalane, pristane, ozokerite, paraffin, ceresin , Hydrocarbons such as petrolatum, microcrystalline wax; higher fatty acids such as oleic acid, isostearic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, undecylenic acid; cetyl alcohol, stearyl alcohol, isostearyl Higher alcohols such as alcohol, behenyl alcohol, octyldodecanol, myristyl alcohol, cetostearyl alcohol; cetyl isooctanoate, isopropyl myristate, hexyldecyl isostearate, diisopropyl adipate, di-2-ethylhexyl sebacate, cetyl lactate, malic acid Diisostearyl, di-2-ethylhexanoic acid ethylene glycol, dicaprate neopentyl glycol, di-2-heptylundecanoic acid glycerin, tri-2-ethylhexanoic acid glycerin, tri-2-ethylhexanoic acid trimethylolpropane, tri Synthetic ester oils such as trimethylolpropane isostearate and pentane erythritol tetra-2-ethylhexanoate; dimethylpolysiloxane, methylphenylpoly Linear polysiloxanes such as oxane and diphenylpolysiloxane; cyclic polysiloxanes such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexanesiloxane; amino-modified polysiloxane, polyether-modified polysiloxane, alkyl-modified polysiloxane, Oil agents such as silicone oils such as modified polysiloxanes such as fluorine-modified polysiloxanes; Anionic surfactants such as fatty acid soap (sodium laurate, sodium palmitate, etc.), potassium lauryl sulfate, triethanolamine ether of alkyl sulfates; Cationic surfactants such as stearyltrimethylammonium, benzalkonium chloride, laurylamine oxide; imidazoline-based amphoteric surfactants (2-cocoyl-2-imida Zolinium hydroxide-1-carboxyethyloxy disodium salt, etc.), betaine surfactants (alkyl betaine, amide betaine, sulfobetaine, etc.), and amphoteric surfactants such as acylmethyltaurine; sorbitan fatty acid esters (sorbitan) Monostearate, sorbitan sesquioleate, etc.), glycerin fatty acids (eg, glyceryl monostearate), propylene glycol fatty acid esters (eg, propylene glycol monostearate), hardened castor oil derivatives, glycerin alkyl ethers, POE sorbitan fatty acid esters (POE sorbitan monooleate, polyoxyethylene sorbitan monostearate, etc.), POE sorbite fatty acid esters (POE-sorbitol monolaurate, etc.), POE glycerin fatty acid ester Tells (POE-glycerol monoisostearate, etc.), POE fatty acid esters (polyethylene glycol monooleate, POE distearate, etc.), POE alkyl ethers (POE2-octyldodecyl ether, etc.), POE alkylphenyl ethers (POE nonylphenyl) Ethers, etc.), Pluronic types, POE / POP alkyl ethers (POE / POP2-decyltetradecyl ether, etc.), Tetronics, POE castor oil / hardened castor oil derivatives (POE castor oil, POE hardened castor oil, etc.), Nonionic surfactants such as sucrose fatty acid ester and alkyl glucoside; polyethylene glycol, glycerin, 1,3-butylene glycol, erythritol, sorbitol, xylitol, maltitol, propylene Polyhydric alcohols such as recall, dipropylene glycol, diglycerin, isoprene glycol, 1,2-pentanediol, 2,4-hexanediol, 1,2-hexanediol, 1,2-octanediol; sodium pyrrolidonecarboxylate Moisturizing ingredients such as lactic acid and sodium lactate; powders such as mica, talc, kaolin, synthetic mica, calcium carbonate, magnesium carbonate, anhydrous silicic acid (silica), aluminum oxide, barium sulfate, etc. whose surface may be treated Body, the surface may be treated, inorganic pigments such as bengara, yellow iron oxide, black iron oxide, cobalt oxide, ultramarine, bitumen, titanium oxide, zinc oxide; surface may be treated, mica Pearl agents such as titanium, fish phosphorus foil, bismuth oxychloride; red 202 which may be raked, red Color 228, Red 226, Yellow 4, Blue 404, Yellow 5, Red 505, Red 230, Red 223, Orange 201, Red 213, Yellow 204, Yellow 203, Blue 1 No., green 201, purple 201, red 204, etc .; organic powders such as polyethylene powder, polymethyl methacrylate, nylon powder, organopolysiloxane elastomer; para-aminobenzoic acid UV absorbers; anthranils Acid UV absorbers; salicylic acid UV absorbers ; cinnamic acid UV absorbers ; benzophenone UV absorbers; sugar UV absorbers; 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole; UV absorbers such as 4-methoxy-4′-t-butyldibenzoylmethane; lower alcohols such as ethanol and isopropanol Vitamin B such as vitamin A or a derivative thereof, vitamin B ₆ hydrochloride, vitamin B ₆ tripalmitate, vitamin B ₆ dioctanoate, vitamin B ₂ or a derivative thereof, vitamin B ₁₂ , vitamin B ₁₅ or a derivative thereof; Vitamin E such as α-tocopherol, β-tocopherol, γ-tocopherol, vitamin E acetate, vitamin D, vitamin H, pantothenic acid, pantethine, vitamins such as pyrroloquinoline quinone, etc .; antibacterial agents such as phenoxyethanol are preferred It can be illustrated. The skin external preparation of this invention can be manufactured by processing these components according to a conventional method.

  Hereinafter, the present invention will be described in more detail with reference to examples. Needless to say, the present invention is not limited to these examples.

<Production Example 1>
Zinc chloride (31 g) and caprylic acid (14.4 g) were dissolved in a mixed solvent of isopropanol (300 g), ethanol (100 g), water (144 g) and 3N aqueous hydrochloric acid (3.6 g) to obtain solution A. . 6N caustic soda (100 g) was gradually poured into the liquid A with stirring at room temperature, and heating was started 20 minutes after the completion of the total injection, and the mixture was maintained at the reflux temperature for 1 hour and cooled. After cooling, decantation and filtration were repeated three times using 50% water-containing isopropanol, and the resulting precipitate was dried at 90 ° C. for 4 hours to obtain Complex 1 as a dried product (31.3 g). This was 56% wurtzite zinc oxide. The shape of this was a scaly layered shape with an average particle size of 0.4 μm. A photomicrograph of this is shown in FIG.

<Production Example 2>
Zinc chloride (31 g) and oleic acid (28.2 g) were dissolved in a mixed solvent of isopropanol (300 g), ethanol (100 g), water (144 g) and 3N aqueous hydrochloric acid (3.6 g) to obtain solution A. . 6N caustic soda (100 g) was gradually poured into the liquid A with stirring at room temperature, and heating was started 20 minutes after the completion of the total injection, and the mixture was maintained at the reflux temperature for 1 hour and cooled. After cooling, decantation and filtration were repeated three times using 50% aqueous isopropanol, and the resulting precipitate was dried at 90 ° C. for 4 hours to obtain Complex 2 as a dried product (41.7 g). This was 42% wurtzite zinc oxide. The shape of this was a scaly layer shape with an average particle size of 0.5 μm.

<Production Example 3>
Zinc chloride (31 g) and hexanoic acid (11.6 g) were dissolved in a mixed solvent of isopropanol (300 g), ethanol (100 g), water (144 g), and 3N aqueous hydrochloric acid (3.6 g) to obtain solution A. . 6N caustic soda (100 g) was gradually poured into the liquid A with stirring at room temperature, and heating was started 20 minutes after the completion of the total injection, and the mixture was maintained at the reflux temperature for 1 hour and cooled. After cooling, decantation and filtration were repeated three times using 50% water-containing isopropanol, and the resulting precipitate was dried at 90 ° C. for 4 hours to obtain Complex 3 as a dried product (25.4 g). This was 65% wurtzite zinc oxide. The shape of this was a scaly layer shape with an average particle size of 0.3 μm.

<Production Example 4>
Zinc chloride (31 g) and myristic acid (22.8 g) were dissolved in a mixed solvent of isopropanol (300 g), ethanol (100 g), water (144 g), and 3N aqueous hydrochloric acid (3.6 g) to obtain solution A. . 6N caustic soda (100 g) was gradually poured into the liquid A with stirring at room temperature, and heating was started 20 minutes after the completion of the total injection, and the mixture was maintained at the reflux temperature for 1 hour and cooled. After cooling, decantation and filtration were repeated 3 times using 50% water-containing isopropanol, and the resulting precipitate was dried at 90 ° C. for 4 hours to obtain Complex 4 as a dried product (39.2 g). This was 45% wurtzite zinc oxide. The shape of this was a scaly layer shape with an average particle size of 0.5 μm.

<Production Example 5>
Zinc chloride (31 g) and isostearic acid (28.4 g) were dissolved in a mixed solvent of isopropanol (300 g), ethanol (100 g), water (144 g) and 3N aqueous hydrochloric acid (3.6 g) to obtain a solution A. . 6N caustic soda (100 g) was gradually poured into the liquid A with stirring at room temperature, and heating was started 20 minutes after the completion of the total injection, and the mixture was maintained at the reflux temperature for 1 hour and cooled. After cooling, decantation and filtration were repeated 3 times using 50% water-containing isopropanol, and the resulting precipitate was dried at 90 ° C. for 4 hours to obtain Complex 5 as a dried product (40.7 g). This was 44% wurtzite zinc oxide. The shape of this was a scaly layer shape with an average particle size of 0.5 μm.

  According to Table 1 shown below, composites 1 to 5 were used to prepare UV-protecting cosmetics 1 to 5, which are skin external preparations of the present invention. That is, the component (a) is processed with a ball mill to prepare a paste, which is combined with the component (b), heated to 90 ° C., dissolved, poured into a mold, cooled and solidified, and applied to the external skin of the present invention. Suncare blocks 1 to 5 (cosmetics for UV protection), which are agents, were obtained. Samples of 50 mg were taken from the upper and lower portions of the sun care block 1 in the direction of solidification, and the SPF value of this sample was measured with a spectrophotometer according to the Cosmetic Industry Association method. Comparative Example 1 in which 83% of the composite 1 of sunblock 1 was replaced with normal zinc oxide (average particle size 0.5) and 17% with caprylic acid was similarly prepared and measured in the same manner. The results are shown in Table 2. From this result, it can be seen that the sun care block 1 which is the external preparation for skin of the present invention has very little vertical variation. This is presumably because zinc oxide does not settle during solidification because of excellent dispersibility.

  The present invention can be applied to powder-containing cosmetics.

3 is an electron micrograph of the composite 1 of Production Example 1 of Example 1. FIG. (Drawing substitute photo)

Claims (8)

With water and an organic solvent and a mixed solvent, the presence of a fatty acid is reacted with a metal salt and an alkali, a metal oxide, allowed formation of a complex with a fatty acid, a product other than the complex thereafter A method for producing a fine-particle metal oxide / fatty acid complex, which comprises a step of removing by washing and then drying. The particulate metal oxide-fatty acid Rukin genus oxide put into the complex is characterized in that it is a zinc oxide, manufacturing method of claim 1. Characterized in that said fatty acid is a fatty acid having 6 to 30 carbon atoms, manufacturing method of claim 1 or 2. The manufacturing method according to claim 1, wherein the metal salt is zinc chloride . The manufacturing method according to claim 1, wherein the particulate metal oxide / fatty acid complex has a scale-laminated shape. A fine-particle metal oxide / fatty acid complex produced by the production method according to claim 1 . A skin external preparation comprising the particulate metal oxide / fatty acid complex according to claim 6 . The external preparation for skin according to claim 7 , which is a cosmetic.

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