JPH0477724B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a cosmetic composition containing ultrafine iron oxide particles whose surface has been treated with an anionic surfactant. More specifically, by blending ultrafine iron oxide particles with an average particle size of 10 to 300 Å that have been surface-treated with anionic surfactants, they have a high degree of transparency and protect the skin from sunburn by blocking harmful ultraviolet rays. Concerning cosmetics that have protection, dispersion, stability, and are comfortable to use. Conventionally, colorants for cosmetics are broadly classified into organic tar pigments, natural pigments, and colored inorganic pigments. Among these, tar pigments often exhibit bright colors;
Although they have been widely used in cosmetics for many years, in recent years the number of pigments that can be used has been limited to a small number due to stricter safety regulations in Japan and overseas, and furthermore, these tar pigments have low fastness to light, acids, alkalis, etc. It has the disadvantage of Furthermore, no clear answer has been obtained regarding the safety of natural dyes, and their fastness is even worse than that of tar dyes. On the other hand, although colored inorganic pigments generally have excellent fastness and safety, they cannot be used in products that require transparency due to problems such as particle size and dispersion. Under these circumstances, the demand for fine particle powders has increased in recent years, and many examples of research are being conducted, mainly on manufacturing methods. A typical example is iron oxide, which is called transparent red pepper and has an average particle size of about 50m, which is already commercially available.However, these pigments, which have a small particle size and a large specific surface area, tend to aggregate easily and cannot be dispersed. The disadvantage is that it is very difficult to Furthermore, it is known that when the skin is exposed to excessive ultraviolet rays, erythema, blisters, and edema occur. Furthermore, repeated exposure to ultraviolet rays for a long period of time destroys collagen fibers in the subcutaneous tissue, promoting the formation of fine wrinkles, pigmentation such as age spots and freckles, and aging of the skin. Among the ultraviolet rays contained in sunlight,
The wavelengths that cause acute inflammation and burns, especially on human skin, are medium-wavelength light (U.
V.-B). Long wave light of approximately 320-400 nm (U.
V.-A) oxidizes melanin in the epidermis and directly causes sun tanning. Most of the short wavelength ultraviolet rays (UV-C) of 280 nm or less are absorbed by the atmosphere, and only a small amount reaches the earth's surface, but medium-wavelength rays (UV-B) reach the skin.
It's more harmful than that. Currently, the main UV absorbers used in cosmetics are para-aminobenzoic acid derivatives, salicylic acid derivatives,
Examples include synthetic ultraviolet absorbers such as benzotriazole derivatives, benzophenone derivatives, and cinnamic acid derivatives, and white inorganic pigments such as titanium oxide and zinc oxide. The former synthetic UV absorber has many problems as a raw material for cosmetics, such as solubility when increasing the amount added to the cosmetic base material, irritation to the skin, deterioration due to UV absorption, and decreased absorption power. There is. On the other hand, the latter type of white inorganic pigment is less susceptible to deterioration due to ultraviolet rays and is not absorbed through the skin, so there is no problem with irritation to the skin. It is a raw material that is extremely difficult to use except in products intended to conceal foundations and the like. In view of these circumstances, the present inventors have conducted intensive research to solve the above drawbacks, and as a result, by blending ultrafine iron oxide particles surface-treated with an anionic surfactant into a cosmetic base material, It protects the skin from ultraviolet rays by blocking ultraviolet light below 320 nm, which has a strong biological effect and causes erythema on the skin, and has excellent dispersibility and
It was discovered that it has excellent transparency and long-term storage stability, and based on this knowledge, the present invention was completed. That is, the present invention provides a cosmetic containing 0.01 to 30% by weight of ultrafine iron oxide having an average particle size of 10 to 300 Å and surface-treated with one or more anionic surfactants. It provides: The ultrafine iron oxide particles used in the present invention are prepared from a hydrated iron oxide sol. Hydrated iron oxide sol is 1)
A method of heating and hydrolyzing an aqueous solution of ferric salt.
2) A method of adding a basic substance to an aqueous ferric salt solution. 3) A method of adding an anion exchange resin to a ferric salt aqueous solution. 4) A method in which a basic substance is added to an aqueous ferric salt solution to form a precipitate of hydrated iron oxide, and after filtering and washing with water, an aqueous ferric salt solution is added to the precipitate and the method is heated to thaw. etc. The particle size of the final product, ultrafine iron oxide particles treated with an anionic surfactant, is determined by the particle size of the hydrated iron oxide sol, but conditions such as the concentration of ferric salt, temperature, and adjustment time are determined. It is possible to change the particle size as necessary. An appropriate amount of anionic surfactant is added to the hydroxyl sol of hydrated iron oxide thus obtained to aggregate colloidal particles. The anionic surfactants used in this case include fatty acid soap, N-acyl sarcosine salt, N-acyl glutamate, alkanesulfonate, 〓-olefin sulfonate, dialkyl sulfosuccinate, alkylaryl sulfonate, Alkylbenzene sulfonates, alkylnaphthalene sulfonates, higher alcohol sulfate ester salts, phosphate ester salts, etc. can be used, but from the viewpoint of skin safety,
Sodium and potassium salts of fatty acids and N-acylsarcosines are preferred. Furthermore, an organic solvent is added and stirred to perform flushing. The organic solvent is removed by distillation from the obtained organosol and heated to 180 to 260°C to obtain ultrafine iron oxide particles whose surface has been treated with an anionic surfactant. Next, the effects of the present invention will be explained. Average particle size
0.5 part of ultrafine iron oxide surface treated with 30Å and 200Å potassium laurate and castor oil
Add 99.5 parts and heat to 60℃ to decompose. Additionally, 75 parts of castor oil was added to 25 parts of rutile-type titanium oxide with an average particle size of 350 m, and thoroughly kneaded using three rollers to form a slurry. Take 2 parts of the slurry, add 98 parts of castor oil, and use a stirrer to further disperse titanium oxide. A film with a thickness of 0.1 mm was made with the dispersion on a transparent quartz plate, and absorbance (ABS) in the wavelength range of 200 to 400 nm and transmission in the wavelength range of 400 to 700 nm were measured using a JASCO UVIDEC-510 spectrophotometer. The rate was measured. The absorbance results are shown in Figure 1, and the transmittance results are shown in Figure 2. Curves a and b are average particle diameters, respectively.
Ultrafine particle iron oxide surface-treated with potassium laurate of 30 Å and 200 Å is shown, and curve c shows the average particle size.
Shows 350m〓 of rutile-type titanium oxide. As is clear from FIGS. 1 and 2, rutile-type titanium oxide with an average particle size of 350 m has little absorption of ultraviolet light and low transmittance of visible light. On the other hand, ultrafine iron oxide particles with average particle diameters of 30 Å and 200 Å that have been surface-treated with potassium laurate absorb ultraviolet rays of 320 nm or less, which have strong biological effects, but have a high transmittance of visible light. It can be seen that it has the properties of a UV absorber and a highly transparent coloring material. Next, O/W sunscreen cream A using ultrafine particle iron oxide with an average particle size of 80 Å and surface-treated with potassium myristate according to the present invention, and rutile type titanium oxide with an average particle size of 350 m as a comparative example. Table 1 shows the formulation of the O/W sunscreen cream B used. Table 1 Sunscreen cream A B Part A, stearic acid, cetanol, vaseline, liquid paraffin, stearic acid monoglyceride, POE (20) sorbitan trioleate, squalane, and ultrafine iron oxide surface treated with potassium myristate (average particle size) 80Å) 4.0% 4.0% 3.0〃 3.0〃 5.0〃 5.0〃 5.0〃 5.0〃 3.0〃 3.0〃 0.4〃 0.4〃 5.5〃 5.5〃 2.0〃 − Part B Rutile type titanium oxide (Average particle size 350 m〓) ・1, 3-Butylene glycol, potassium hydroxide, purified water bentonite, preservative - 2.0〃 6.0〃 6.0〃 0.5〃 0.5〃 64.0〃64.0〃 0.5〃 0.5〃 Appropriate amount Appropriate amount To prepare, disperse Part B uniformly with a homomixer. Keep at 75℃. Heat and dissolve part A, mix and keep at 70℃. Add part A to part B, emulsify and disperse with a homomixer, and cool to 30°C while stirring to obtain a product. The usability and effectiveness of the sunscreen creams A and B prepared in this way were actually used by 20 women for 3 consecutive months in July, August, and September.The results are shown in Tables 2 and 2. Shown in 3.

[Table] *The evaluation method is the number of people who answered that the ``spreadiness'', ``stickiness'', ``freshness'', and ``overall evaluation'' were good. Also, "white spots" and "skin irritation"
is the number of people who felt ``white spots'' and ``skin irritation.''

[Table] Efficiency.
As is clear from Tables 2 and 3, the average particle diameter of the surface treated with potassium myristate according to the present invention is 80.
Sunscreen Cream A, which uses Å's ultrafine particle iron oxide, improves the feeling of use, fine wrinkles, and age spots, and improves sunburn compared to general sunscreen creams that use rutile-type titanium oxide with an average particle size of 350 m. It has shown to be excellent in prevention. Examples of the present invention are shown below. (The blending ratio is in weight%). Example 1 Sunoil Part A - Ultrafine particle iron oxide surface treated with sodium lauroyl sarcosinate (average particle size 10-300 Å) - Squalane 0.03% 4.0 Part B - Liquid paraffin - Olive oil - Antioxidant and fragrance 4.0〃 30.0〃 65.8〃 Heat and dissolve appropriate amounts of Part A and Part B respectively. Parts A and B are added and mixed under stirring and cooled. Example 2 Ultrafine particle iron oxide surface treated with lipstick sodium palmitoyl sarcosinate (average particle size 10-300 Å)
5.0% ・ Squalane 10.0% ・ Red No. 204 0.6〃 ・ Orange No. 203 1.0〃 ・ Red No. 223 0.2〃 ・ Candelilla wax 9.0〃 ・ Solid paraffin 8.0〃 ・ Beeswax 5.0〃 ・ Carnauba wax 5.0〃 ・ Rano Phosphorus 11.0〃・Castor oil 44.8 - Antioxidant and fragrance Appropriate amount Add ultrafine iron oxide particles whose surface has been treated with sodium palmitoylsarcosine to squalane and uniformly disperse by heating (pigment part 1). Add Red No. 204, Orange No. 203, and Red No. 223 to a portion of castor oil and process with a roller (pigment part 2). After mixing the other components and heating and melting them, pigment parts 1 and 2 are added and uniformly dispersed. After dispersion, it is poured into molds and rapidly cooled, and the sticks are inserted into containers for framing. Example 3 Solid white powder Part A: Talc, titanium oxide, zinc stearate 86.0% 3.0〃 1.0〃 Part B: Ultrafine particle iron oxide surface treated with potassium lauroyl sarcosine (average particle size 10-30 Å) - Squalane and sorbitan mono Oleate, preservatives and fragrances 1.0〃 8.0〃 0.5〃 Appropriate amount Heat and dissolve Part B and disperse uniformly. While thoroughly mixing part A with a blender, add part B to the mixture to make it homogeneous, process with a pulverizer, and compression mold. Example 4 Foundation cream part A, liquid paraffin, cetanol, solid paraffin, stearic acid monoglyceride, POE (20) sorbitan monostearate, ultrafine iron oxide surface treated with sodium myristate (average particle size 10~ 300Å) ・Fragrance 28.0% 2.0〃 5.0〃 2.4〃 2.6〃 5.0〃 Appropriate amount Part B・1,3-butylene glycol・Titanium oxide・Ordinary iron oxide・Purified water・Preservative 10.0% 8.0〃 2.0〃 34.0〃 Appropriate amount B Disperse the mixture uniformly using a homomixer and keep at 75℃. Heat and dissolve part A, mix and keep at 70℃. Add part A to part B, emulsify and disperse with a homomixer, and cool to 30°C while stirring to obtain a product.

[Brief explanation of the drawing]

(1) Figure 1 shows the amount of a
(Ultrafine iron oxide particles with an average particle size of 30 Å surface-treated with potassium laurate), b (Ultra-fine iron oxide particles with an average particle size of 200 Å surface-treated with potassium laurate), c (Rutile with an average particle size of 350 m〓) It shows the absorbance in the wavelength range of 200 to 400 nm when dispersing titanium oxide (type titanium oxide). (2) Figure 2 shows castor oil, a cosmetic base material, containing a (ultrafine iron oxide particles with an average particle size of 30 Å surface-treated with potassium laurate) and b (average particle size with an average particle size of 30 Å surface-treated with potassium laurate). This shows the transmittance in the wavelength range of 400 to 700 nm when dispersing ultrafine iron oxide particles (200 Å) and c (rutile titanium oxide with an average particle size of 350 m).

Claims (1)

[Scope of Claims] 1. It is characterized by containing 0.01 to 30% by weight of ultrafine iron oxide particles having an average particle size of 10 to 300 Å and surface-treated with one or more anionic surfactants. cosmetics. 2 The anionic surfactant has the general formula () R-COOM (R in the formula is an alkyl group and M is sodium or potassium.) (In the formula, R is an alkyl group, and M is sodium or potassium.) The cosmetic according to claim 1, which is one or a combination of two or more of the following.