JPH1087472A - Titanium dioxide coated in high concentration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for suppressing a generated radical when titanium dioxide absorbs light rays. SOLUTION: In the titanium dioxide whose surface is coated with the oxide of a metal except titanium, when a HeLa cell is irradiated with ultraviolet light and cultured in a medium containing 1% of the zinc oxide whose surface is coated and in a medium not containing the zinc oxide, the survival rate of the HeLa cell in the medium containing the zinc oxide is >=90% so that of the HeLa cell in the medium not containing the zinc oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a surface-coated titanium dioxide suitable for a raw material for cosmetics.

[0002]

2. Description of the Related Art Titanium dioxide is widely used as a concealing agent, a light-shielding agent and the like in make-up cosmetics and ultraviolet ray preventing cosmetics because of its excellent hiding power. Titanium dioxide excites an electronic state when absorbing light rays such as ultraviolet rays, and thus is excellent in absorbing these light rays. It is known that the electronic state excited by absorbing light in this way returns to the original ground state by generating radicals and releasing energy. In recent years, it has been suggested that radicals caused by the light absorption of titanium dioxide are undesirable for living organisms. For this reason, it is known that the generation of radicals is suppressed to some extent by coating the surface of titanium dioxide with a metal oxide of 5 to 6% by weight. It was not known what effect it had. or,
No attempt has been made to coat the surface of titanium dioxide with oxides of other metals at high concentrations. Therefore, it has not been known at all that such high-concentration surface-coated titanium dioxide suppresses radicals generated when light is absorbed, and has little effect on living bodies.
Furthermore, such a high-concentration surface-coated titanium dioxide has never been incorporated into a composition such as a cosmetic.

[0003]

SUMMARY OF THE INVENTION In view of such a situation, the present inventors have studied the effects of titanium dioxide on light absorption and the effect on living organisms. It has been found that it exerts cytotoxicity on Hera cells. After further study,
It has been found that the conventionally known 5-6% metal oxide-coated titanium dioxide cannot exert a sufficient cytotoxicity-suppressing effect on Hera cells. The present invention has been made under such circumstances, the present invention,
An object of the present invention is to provide a modified titanium dioxide having a sufficient cytotoxicity-suppressing effect upon irradiation of Hera cells with light.

[0004]

In view of such a situation, the present inventors have conducted intensive studies for a modified titanium dioxide having a sufficient cytotoxicity suppressing effect upon irradiation with light, and as a result, have found that a high concentration of the modified titanium dioxide has been obtained. Such properties were found in the surface-coated titanium dioxide, and the invention was completed. Further, they have found that such a high concentration surface-coated titanium dioxide is useful as a raw material for cosmetics because it has low toxicity to cells even when irradiated with light, and has further developed the invention. Hereinafter, the present invention will be described in detail focusing on embodiments of the invention.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) Surface-coated titanium dioxide of the present invention The surface-coated titanium dioxide of the present invention is obtained by culturing Hera cells after UV irradiation in a medium containing 1% of the surface-coated titanium dioxide and a medium not containing the same. The viability of Hera cells is 90% or more, more preferably 95% or more, of the viability of Hera cells in a medium containing no viable cells. This property is due to the fact that the surface of titanium dioxide is made of an oxide of another metal and the total amount is 10%.
It is realized by coating at a concentration of not less than% by weight. However, if the coating amount is too high, the concealing effect of titanium dioxide is impaired, so the upper limit of the coating amount is suitably about 70% by weight. That is, in the surface-coated titanium dioxide of the present invention, the coating amount of the oxide of another metal is preferably 10 to 70% by weight, more preferably 15 to 65% by weight, and
0-60% by weight is more preferred. As the titanium dioxide to be coated, titanium dioxide itself may be used, but a titanium dioxide doped with a transition metal such as iron between crystal lattices can also be used, and a doped one is preferable because generation of radicals is suppressed. . The doping metal is preferably iron, and the doping amount is preferably 1 to 30% by weight based on titanium dioxide. The particle size is preferably 0.2 to 10 millimicrons in view of the versatility of cosmetics, pharmaceutical compositions, paints, and the like. In addition, the titanium dioxide may contain any commonly known optional components.
As a method of coating the surface of such titanium dioxide, any conventional coating method can be used without any particular limitation.For example, mechanochemically fixed or metal hydroxide or the like can be used. A method of attaching to titanium dioxide and then baking it at a high temperature to obtain a baked oxide can be used. Of these, the method of baking a hydroxide is preferred because of its strong adhesion. As the metal constituting the oxide of the metal used for coating in this way, aluminum, silicon, zirconium and the like can be mentioned, and these can be used alone or in combination of two or more. It is also possible to coat two or more of them sequentially in multiple layers.

(2) Composition of the Present Invention The composition of the present invention is characterized by containing the high concentration surface-coated titanium dioxide. As such a composition, for example, a cosmetic, a pharmaceutical composition, a paint and the like can be exemplified, and among them, application to a cosmetic is most preferable. Among the cosmetics, make-up cosmetics having both a large amount of titanium dioxide and a large number of use opportunities are preferable, and base make-up cosmetics such as foundations are particularly preferable. The preferred content of the high concentration surface-coated titanium dioxide in the composition of the present invention is 0.1 to 60% by weight, more preferably 0.1 to 50% by weight, still more preferably 0.1 to 50% by weight. ４０40% by weight. The compositions of the present invention can contain any of the ingredients normally used in these compositions, in addition to the essential ingredient, high concentration surface coated titanium dioxide. Such optional components include, for example, in cosmetics, hydrocarbons such as petrolatum and microcrystalline wax, esters such as jojoba oil and gay wax, triglycerides such as tallow, olive oil, cetanol, oleyl alcohol and the like. Higher alcohols, fatty acids such as stearic acid and oleic acid, polyhydric alcohols such as glycerin and 1,3-butanediol, nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, ethanol , Carbopol and other thickeners, preservatives, ultraviolet absorbers, antioxidants, dyes, powders and the like can be exemplified, in pharmaceutical compositions, excipients, binders,
Examples include coating agents, lubricants, sugar coatings, disintegrants, bulking agents, flavoring agents, emulsifying / solubilizing / dispersing agents, stabilizers, pH adjusters, isotonic agents, and the like. , A pigment, a plasticizer, a dispersant, and a solvent. The composition of the present invention can be produced by treating these components according to a conventional method.

[0007]

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

Embodiment 1 Production Example 85 g of titanium dioxide was dispersed in 500 ml of water, and 16.7 g of aluminum nitrate dissolved in 300 ml of water was added thereto.
Dissolved in 00 ml and added. The precipitate is collected by filtration, washed well with water,
By baking at 1000 ° C. for 48 hours, 93 g of titanium dioxide 1 having a high concentration surface coating was obtained. As a result of X-ray analysis, it was found that this was coated with 12% alumina with respect to the total amount.

Embodiment 2 FIG. Production Example As in Example 1, high-concentration surface-coated titanium dioxide 2 coated with 28% alumina was coated with 9
6 g were obtained.

Embodiment 3 FIG. Production Example A high concentration surface-coated titanium dioxide 3 coated with alumina having a coating amount of 51% in the same manner as in Example 1
1 g was obtained.

Embodiment 4 FIG. Production Example A high-concentration surface-coated titanium dioxide 4 coated with alumina having a coating amount of 67% in the same manner as in Example 1
1 g was obtained.

Embodiment 5 FIG. Production Example In the same manner as in Example 1, an aqueous solution of sodium silicate in which titanium dioxide was dispersed was neutralized with hydrochloric acid and calcined to obtain a coating amount of 2%.
97 g of high concentration surface coated titanium dioxide 5 coated with 3% silica gel was obtained.

Embodiment 6 FIG. Production Example As in Example 1, an aqueous solution of sodium silicate in which titanium dioxide was dispersed was neutralized with hydrochloric acid and calcined to obtain a coating amount of 5%.
98 g of highly concentrated surface coated titanium dioxide 6 coated with 5% silica gel was obtained.

Embodiment 7 FIG. Production Example In the same manner as in the example, an aqueous solution of zirconium nitrate in which titanium dioxide was dispersed was neutralized with an aqueous solution of sodium hydroxide, and 83 g of titanium dioxide 7 having a high concentration surface coating coated with zirconia having a coating amount of 32% was obtained.

Embodiment 8 FIG. Production Example In the same manner as in the Example, an aqueous solution of zirconium nitrate in which titanium dioxide was dispersed was neutralized with an aqueous solution of sodium hydroxide, and 83 g of titanium dioxide 8 having a high concentration surface coating coated with zirconia having a coating amount of 65% was obtained.

Embodiment 9 Production Example In the same manner as in Example, an aqueous solution of zirconium nitrate in which titanium oxide 1 having a high concentration of surface coating was dispersed was neutralized with an aqueous solution of sodium hydroxide.
74 g of high-concentration surface-coated titanium dioxide 9 having a coating amount of zirconia of 8%, that is, coated with 8% of zirconia and 12% of alumina was obtained.

Example 10 The titanium dioxide of Example 2 was replaced with 3% iron-doped titanium dioxide, and 76 g of a high concentration surface-coated titanium dioxide 10 coated with 22% alumina was used.
I got

Embodiment 11 FIG. Test Example 1 of the above high concentration surface coated titanium dioxide 1-10
Mix 1% in MEM medium containing 0% FBS and add 10%
Inoculate Hera cells at ⁶ cells / ml and add BL
1 J / c with an irradiator equipped with the same number of B lamps and SE lamps
m2 ultraviolet rays, and this was irradiated with 10% FBS-containing MEM.
The cells were cultured in a medium under an air stream containing 5% carbon dioxide for 48 hours, and the number of colonies formed was counted. The same operation was performed using a medium containing no high-concentration surface-coated titanium dioxide as a control, and a value obtained by dividing by the number of control colonies and multiplying by 100 was determined as a specific survival rate. For comparison, normal titanium dioxide (Comparative Example 1) and titanium dioxide coated with 6% silica (Comparative Example 2) were used. Table 1 shows the results. This indicates that the high-concentration surface-coated titanium dioxide of the present invention hardly causes damage to Hera cells under ultraviolet rays.
In addition, it is understood that the amount of the metal oxide to be coated with titanium dioxide is insufficient at 6% as usual, but it is necessary to be at least 10%, more preferably at least 30%.

[0019]

[Table 1]

Examples 12 to 16 Formulation Examples A foundation for ultraviolet protection was prepared according to the following formulation. That is, after mixing A with a Henschel mixer, the mixture was crushed with a pulverizer equipped with a 3 mm-diameter round hole screen, returned to the Henschel mixer, and gradually added while mixing to coat, and a 1 cm herringbone screen was mounted. Finish grinding was carried out with a pulverizer, filled in a metal plate, and pressed to obtain a foundation.

[0021]

[Table 2]

Examples 17 to 21 Formulation Examples A foundation for ultraviolet protection was prepared according to the following formulation. That is, after mixing A with a Henschel mixer, the mixture was crushed with a pulverizer equipped with a 3 mm-diameter round hole screen, returned to the Henschel mixer, and gradually added while mixing to coat, and a 1 cm herringbone screen was mounted. Finish grinding was carried out with a pulverizer, filled in a metal plate, and pressed to obtain a foundation.

[0023]

[Table 3]

Embodiment 22 FIG. Formulation Example A skin external pharmaceutical composition was prepared according to the following formulation. That is, a, b, and c are each heated to 80 ° C to dissolve the respective components, knead well with b, dilute by adding b, add d, disperse, and gradually add c to this to emulsify. Thus, a pharmaceutical composition for external use on the skin was obtained. A Glycerin 5 parts by weight 70% aqueous maltitol solution 5 parts by weight 1,3-butanediol 5 parts by weight Methyl paraben 0.3 parts by weight butyl paraben 0.1 part by weight Triglycerin diisostearate 5 parts by weight Indomethacin 1 part by weight b Flow Paraffin 15 parts by weight Dimethicone 10 parts by weight C Water 52.6 parts by weight d Powder of Example 10 1 part by weight

[0025]

According to the present invention, it is possible to provide a modified titanium dioxide having a sufficient cytotoxicity inhibitory effect upon irradiation of Hera cells with light.

Claims (6)

[Claims] The present invention relates to a titanium dioxide whose surface is coated with an oxide of a metal other than titanium, wherein a medium containing 1% of the surface-coated titanium dioxide and a medium not containing the same are provided,
A surface-coated titanium dioxide, wherein the viability of Hera cells in a medium containing the cultured Hera cells after irradiation with ultraviolet rays is 90% or more of the viability of Hera cells in a medium that does not contain the Hera cells. 2. The surface-coated titanium dioxide according to claim 1, wherein the metal of an oxide of a metal other than titanium for coating the surface is one or more selected from aluminum, zirconium, and silicon. 3. The weight of the oxide of a metal other than titanium for coating the surface is 10 to 70% by weight based on the total amount of the titanium dioxide coated on the surface.
The surface-coated titanium dioxide according to claim 1. 4. One or two elements selected from aluminum, zirconium and silicon in an amount of 10 to 70% by weight based on the total amount.
Titanium dioxide whose surface is coated with more than one kind of oxide. 5. A composition comprising the surface-coated titanium dioxide according to claim 1. 6. The composition according to claim 5, which is a cosmetic.