JPS635377B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to long wavelength ultraviolet absorbers, more specifically,
A benzophenone derivative having 1 to 4 hydroxyl groups on two benzene rings was adsorbed onto a composite consisting of a montmorillonite clay mineral and a metal oxide (hereinafter sometimes referred to as a "clay-metal oxide composite"). It relates to a long wavelength ultraviolet (hereinafter referred to as "UV-A") absorber. [Prior art and its problems] It is known that ultraviolet rays cause various changes in the skin. Dermatologically, the wavelength of action is
Ultraviolet rays are divided into long wavelength ultraviolet rays of 400 to 320 nm, medium wavelength ultraviolet rays of 320 to 290 nm, and short wavelength ultraviolet rays of 290 nm or less, and are called UV-A, UV-B, and UV-C, respectively. Normally, most of the sources of ultraviolet radiation to which humans are exposed are sunlight, but the ultraviolet rays that reach the ground are UV-A and UV-B, while UV-C is absorbed in the ozone layer and almost never reaches the ground. Among the ultraviolet rays that reach the ground, UV-B forms erythema and blisters when the skin is irradiated with more than a certain amount of light.
In addition, melanin formation is enhanced, causing changes in the skin such as pigmentation. On the other hand, conventionally,
It was thought that UV-A did not cause much change in the skin. However, in recent years, it has been revealed through electron microscopy and histochemical techniques that the skin undergoes changes even when exposed to UV-A irradiation. In particular, unlike UV-B, UV-A's energy reaches the dermis, causing micro-chronic changes in the elastic fibers in blood vessel walls and connective tissue, and these changes are thought to lead to accelerated skin aging. It is being In addition, UV-A has the effect of blackening the skin immediately after irradiation (immediate blackening), and UV-B
UV-A is known to enhance the degenerative effects of UV-A on the skin, and it is thought that UV-A is a factor in the occurrence and aggravation of age spots and freckles. As is clear from these facts, it is important to protect the skin not only from UV-B but also from UV-A in terms of preventing accelerated aging of the skin and preventing the occurrence and aggravation of age spots and freckles. However, research on the effects of UV-A on the skin has a short history, and when applied to the skin,
The reality is that not much is known about substances that effectively absorb UV-A. At present, only a few dibenzoylmethane derivatives and cinnamic acid derivatives are known, but most of them are fat-soluble (West German Patent Publication No. 2728241, West German Patent Publication No. 2728243, Japanese Patent Application Laid-Open No. 1983-61641). Publication No. 52-46056, No. 57
-197209), and there are few water-soluble ones (Japanese Patent Application Laid-Open No. 57-59840). Therefore, these UV-A
When attempting to add absorbents to cosmetics, there were limitations on the properties of the cosmetic base. In addition, in the case of organic ultraviolet absorbers, problems remain with respect to safety such as irritation to the skin, transdermal absorption, sustainability due to diffusion on the skin, etc. On the other hand, inorganic pigments can also reflect and scatter ultraviolet rays, which are not absorbed through the skin.
Although it has advantages such as being safe and not irritating to the skin, it is impossible to selectively absorb and protect against specific ultraviolet rays. That is, although inorganic pigments have high transparency to visible light, they have the disadvantage that they cannot selectively and effectively absorb only the UV-A region. Furthermore, recently, UV-A UV absorbers made from montmorillonite clay mineral benzophenone ultraviolet absorbers have been developed.
An absorbent was developed (Japanese Patent Application Laid-open No. 81124/1983). However, the amount of UV-absorbent adsorbed by montmorillonite clay minerals is small, and the bond between clay minerals and UV-absorbers is weak, so when this UV-A absorber is used as a water-based cosmetic, the UV-absorber will The drawback is that it forms a salt with the alkali metals contained in the clay and is liberated from the clay, changing the pH of the water layer to a high pH of 9 to 10. Therefore, this UV−
Absorbent A can be used as a powder cosmetic, but
Creams, milky lotions, lotions, and the like have limited uses and are not fully satisfactory. [Means for Solving the Problems] Under such circumstances, the present inventor conducted various studies and found that the longest maximum absorption wavelength of the benzophenone derivative represented by the general formula () below is on the considerably shorter wavelength side than 350 nm. However, when it is adsorbed onto a clay-metal oxide composite, its maximum absorption shifts to longer wavelengths, allowing it to selectively and effectively absorb and protect light in the UV-A region. We discovered that the amount of adsorption increases and the adsorption power is stronger than when adsorbed only to clay minerals, and that the UV-A absorbent thus obtained can also be used in water-based cosmetics. Completed the invention. That is, the present invention provides the following general formula () (In the formula, m X's and n Y's are each the same or different and represent an alkyl or alkoxy group having 1 to 24 carbon atoms, a sulfonic acid group, or an alkali metal salt thereof, and n and m are 0 to 3 carbon atoms. A long-wavelength ultraviolet absorber characterized by adsorbing a benzophenone derivative represented by (integer: k + l is an integer from 1 to 4) on a composite consisting of a montmorillonite clay mineral and a metal oxide, and a long-wavelength ultraviolet absorber containing the same. The purpose of the present invention is to provide cosmetics that In the present invention, examples of the benzophenone derivative represented by formula () include 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 2-hydroxy-4-methoxybenzophenone. Non-5-sulfonic acid, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4 Sodium '-dimethoxybenzophenone-5-sulfonate, 2,4-dihydroxybenzophenone, sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 2-hydroxy-4-octyloxybenzophenone , 2-
Hydroxy-4'-methoxybenzophenone, 2-
Hydroxybenzophenone, 4-hydroxybenzophenone, 2-hydroxy-4-methylbenzophenone, 2-hydroxy-5-methylbenzophenone, 2,5-dihydroxybenzophenone,
Examples include 2-hydroxy-5-methoxybenzophenone. Examples of the montmorillonite clay mineral include water-swellable natural clay minerals such as montmorillonite, hectorite, and bentonite, as well as synthetic ones. Suitable examples include various artificial fluorine-containing layered silicates that are swellable in water and have ion exchange ability. In addition, as the metal oxide to be combined with the montmorillonite clay mineral, for example, one in which the clay-metal oxide complex becomes basic, that is, this complex is suspended in anhydrous benzene, and a solution of bromothymol blue in anhydrous benzene is used. A liquid that shows a green color when a few drops of it is added is preferably used. Examples of such metal oxides include α-Al ₂ O ₃ , γ-
Al ₂ O ₃ , α-AlOOH, γ-AlOOH, γ-Al
(OH) ₃ , BeO, CdO, CuO, Cr ₂ O ₃ , CaO,
BaO, Fe(OH) ₂ , α−Fe ₂ O ₃ , γ−Fe ₂ O ₃ , α−
FeOOH, γ-FeOOH, MgO, MnO, NiO,
Metal oxides such as SiO ₂ , ZnO, Y ₂ O ₃ ; Al ₂ O ₃ ,
Examples include metal oxides such as SiO ₂ adsorbed with NaOH, KOH, alkali metals, alkaline earth metals, NH ₃ , NR ₃ (R: hydrogen, alkyl, alkanol), etc.; Alternatively, two or more types are used in combination. The clay-metal oxide composite used in the present invention can be prepared by adding a pre-prepared dispersion of a fine metal oxide colloid to a suspension of montmorillonite clay minerals in water, according to a conventional method. The product is prepared by filtering, washing, drying, and optionally pulverizing the product. A dispersion of a metal oxide colloid can be prepared, for example, by hydrolyzing an alkoxide of the metal in water and peptizing the resulting precipitate with an acid, or by dissolving a salt of the metal, such as a chloride, in water and adding an alkali such as sodium hydroxide. Therefore, it can be obtained by hydrolysis. The clay-metal oxide composite thus obtained has a porous structure containing a metal oxide between the layers of the montmorillonite clay mineral, and thus functions as a host compound for the benzophenone derivative (). The UV-A absorber of the present invention can be prepared by dissolving, for example, a benzophenone derivative in water or an organic solvent to a concentration of, for example, 0.1 to 50% by weight, and adding this to a dispersion of a clay-metal oxide complex under stirring. The clay-metal oxide complex is gradually added, and then the clay-metal oxide complex is filtered, washed and dried, or the solvent is distilled off. As the solvent for dissolving the benzophenone derivative and the solvent for dispersing the solid base, for example, water, alcohol, benzene, hexane, etc. are preferably used. The amount of benzophenone derivative used to treat the clay-metal oxide complex varies depending on the number of basic sites and adsorption capacity, but generally the benzophenone derivative is 0.01 to 1% (by weight) to the clay-metal oxide complex. , particularly preferably 0.1 to 1% (by weight). The clay-metal oxide composite used in the present invention has a structure in which fine particles of metal oxide are stably dispersed on the surface or between layers of layered crystals in clay minerals, and in particular titanium oxide, aluminum oxide,
When a white metal oxide such as magnesium oxide is used, a strong ultraviolet ray shielding effect appears.
The UV-A absorber of the present invention, in which a benzophenone derivative is adsorbed onto such a clay-metal oxide composite, has an ultraviolet scattering effect of the clay-metal oxide in addition to the ultraviolet absorption effect of the benzophenone derivative itself, and is extremely effective. It can effectively prevent UV rays. The UV-A absorber of the present invention can be incorporated into cosmetics, pharmaceuticals, etc. for the purpose of preventing the harmful effects of ultraviolet rays on the skin. The amount of the UV-A absorber of the present invention to be incorporated into cosmetics varies depending on the type (dosage form) of the cosmetics, but
Generally, 0.1 to 20 as a benzophenone derivative
% by weight, especially 0.5 to 10% by weight. The cosmetics of the present invention can be produced by blending this UV-A absorber into a known cosmetic base by a conventional method and making it into a dosage form such as a cream, solution, oil spray, stick, emulsion, foundation, or ointment. prepared. That is, benzophenone derivatives, clay-
By selecting and using metal oxide complexes according to the cosmetic base, we can create oil-based cosmetic oils, oil-based creams and oil-based emulsions that contain large amounts of oil, and weakly oily creams and weakly oily products that contain large amounts of water. It is possible to produce all types of cosmetics that have UV-A absorption properties, from basic cosmetics such as emulsions and water-based lotions to make-up cosmetics such as oil-based foundations and lipsticks. . Suitable bases and solvents include solid or liquid paraffin, crystal oil,
Hydrocarbons such as ceresin, ozokerite or montan wax; vegetable oils or animal fats and waxes such as olive, earth wax, carnauba wax, lanolin or spermaceti; further stearic acid, palmitic acid, oleic acid, glycerin monostearate, Fatty acids and their esters such as glycerin distearate, glycerin moreoleate, isopropyl myristate, isopropyl stearate or butyl stearate; ethyl alcohol,
Examples include alcohols such as isopropyl alcohol, cetyl alcohol, stearyl alcohol, palmityl alcohol, and hexyldodecyl alcohol. Further, polyhydric alcohols having a moisturizing effect such as glycol, glycerin or sorbitol can also be used. It is preferable that the cosmetic composition of the present invention is further combined with other UV-B absorbers. Examples of UV-B absorbers include p-methylbenzylidene-
D,L-sulfonate or its sulfonic acid sodium salt; 2-phenylbenzimidazole-5-sulfonic acid sodium salt, 3,4-dimethylphenylglyoxylic acid sodium salt, 4-phenylbenzophenone, 4-phenyl Benzophenone
Examples include 2'-carboxylic acid isooctyl ester, p-methoxycinnamic acid ester, 2-phenyl-5-methylbenzoxazole, and p-dimethylaminobenzoic acid ester. In addition to the above-mentioned components, various additives can be added to the cosmetic composition of the present invention. Suitable additives include, for example, W/O and O/W emulsifiers. As the emulsifier, commercially available emulsifiers can be used. Thickeners such as methylcellulose, ethylcellulose or carboxymethylcellulose, polyacrylic acid, tragacanth, agar or gelatin can also be added as additives. In addition, fragrances, preservatives, humectants, emulsion stabilizers,
Medicinal ingredients, colorants, etc. can also be added. [Action and effect] The long-wavelength ultraviolet absorber of the present invention selectively and effectively absorbs UV-A, so it can protect against skin damage caused by UV-A, and it also protects against water, organic solvents, oils, sebum, etc. Because it does not dissolve in water, it is safe because it is not absorbed through the skin, and it has the excellent characteristics of being long-lasting. [Examples] Next, examples, reference examples, and test examples will be given and explained. Reference example Synthesis of montmorillonite-TiO ₂ composite: Titanium tetraethoxide (Ti(OC ₂ H ₅ ) ₄ ) 22.8
g was added to 300 ml of water for hydrolysis, and the resulting white precipitate was thoroughly dispersed by stirring vigorously. next
100 ml of 1N hydrochloric acid was added and stirred for 1 hour to obtain a transparent sol. This sol was mixed with montmorillonite from Yamagata Prefecture (product name ``Kunipia G4'', cation exchange capacity
100 meq/100g) was added dropwise over 10 minutes to a suspension of 600ml of water with stirring, and the stirring was continued at 50°C for an additional hour. The product was then filtered, washed, dried and ground. The powder thus obtained was white and contained 36% as _TiO2 . Example 1 An amount corresponding to the saturated adsorption amount of the benzophenone derivative to the clay-metal oxide complex was dissolved in 2 to 3 ml of ethanol, and this was stirred into the clay-metal oxide complex dispersed in 20 ml of ethanol. Added gradually. Thereafter, ethanol was distilled off to obtain long wavelength ultraviolet absorbers shown in Table 1.

[Table] From Table 1, it can be seen that the amount of adsorption of 2,2',4,4'-tetrahydroxybenzophenone increases by 3 to 6 times in the montmorillonite-metal oxide composite compared to montmorillonite alone. . Also, by adding water to the UV-absorber in Table 1,
When we conducted an elution test for 2,2',4,4'-tetrahydroxybenzophenone, we found that the pH of the water was
In contrast, with the product of the present invention, no change in PH was observed. When UV of the aqueous layer was observed, elution of 2,2',4,4'-tetrahydroxybenzophenone was observed in the comparative product. On the other hand, in the product of the present invention, there was almost no elution. Test Example 1 The long-wavelength ultraviolet absorption effect of the UV-absorber obtained in Example 1 was examined using an absorption spectrum. The absorption spectra were determined by suspending the UV-absorber in diisostearyl malate at a concentration of 10% by weight.
It was coated on a quartz plate to a thickness of 30 μm, and the transmittance was measured. The difference spectrum from that of montmorillonite is shown in FIG. From FIG. 1, it can be seen that the UV-A absorber of the present invention exhibits maximum absorption at longer wavelengths than the benzophenone derivative alone, and selectively and effectively protects against so-called UV-A. Example 2 Oil: UV-A absorber (1) 30 (% by weight) Isopropyl myristate 10 Liquid lanolin 5 Mineral oil Remaining amount The above composition is kneaded in a roll mill to obtain an oil with uniform properties. Example 3 Emulsion: UV-A absorber (1) 5 (% by weight) Stearic acid 1 Setanol 2 Vaseline 2.5 Squalane 4 Hardened palm oil 2 Polyoxyethylene (20) Sorbitan monostearate 1.5 Lipophilic sorbitan monostearate
1.2 Glycerin 3 Potassium hydroxide 0.2 Carboxyvinyl polymer 0.2 Preservative Appropriate amount Fragrance Trace amount Purified water Remaining amount A milky lotion was obtained by blending in a conventional manner. Example 4 W/O type cream: UV-A absorber (1) 10 (wt%) Vaseline 6 Cholesterol 0.6 Cetol 0.5 Sorbitan sesquiolate 2 Liquid lanolin 4 Isopropyl palmitate 8 Squalane 10 Solid paraffin 4 Glycerin 3 Preservative Appropriate amount Fragrance Ingredients Trace amount Purified water Remaining amount A W/O type cream was obtained by blending in a conventional manner. Example 5 O/W type cream: UV-A absorber (1) 15 (wt%) Stearic acid 2 Setanol 4 Vaseline 5 Squalane 8 Hardened palm oil 4 Polyoxyethylene (20) Sorbitan monostearate 2 Sorbitan monostearate 2 Glycerin 5 Preservative Appropriate amount Fragrance Trace amount Purified water Remaining amount Blend in a conventional manner to obtain an O/W type cream. Example 6 Oil-based foundation: UV-A absorber (1) 12 (wt%) UV-A absorber (2) 10 Liquid paraffin 15 Isopropyl palmitate 10 Lanolin alcohol 3 Microcrystalline wax 7 Ozokerite 8 Chillandrillawa Tuxus 0.5 Preservative Appropriate amount Titanium oxide 8 Kaolin 18 Talc 6 Red iron oxide 1.5 Black iron oxide 0.5 Fragrance Small amount An oily foundation was obtained by blending in a conventional manner.

[Brief explanation of the drawing]

Figure 1 shows the products of the present invention (1), (2), (3) and 2, 2', 4,
4′-Tetrahydroxybenzophenone (THB)
shows the absorption spectrum in the ultraviolet region. In addition, in the figure,
a, b and c show difference spectra between montmorillonite and the spectrum. a...Product of the present invention (1), b...Product of the present invention (2), c...
Invention product (3), d...THB

Claims (1)

[Claims] First-order general formula () (In the formula, m X's and n Y's are each the same or different and represent an alkyl or alkoxy group having 1 to 24 carbon atoms, a sulfonic acid group, or an alkali metal salt thereof, and n and m are 0 to 3 carbon atoms. 1. A long-wavelength ultraviolet absorber characterized in that a benzophenone derivative represented by the following formula is adsorbed onto a composite consisting of a montmorillonite clay mineral and a metal oxide. 2nd order general formula () (In the formula, m X's and n Y's are each the same or different and represent an alkyl or alkoxy group having 1 to 24 carbon atoms, a sulfonic acid group, or an alkali metal salt thereof, and n and m are 0 to 3 carbon atoms. A cosmetic containing a long-wavelength ultraviolet absorber in which a benzophenone derivative represented by the following formula is adsorbed onto a composite consisting of a montmorillonite clay mineral and a metal oxide.