JP3115760B2 - Iron-containing ultrafine titanium dioxide dispersion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dispersion of iron-containing ultrafine titanium dioxide in water or oil, a sunscreen cosmetic using the same, and an ultraviolet ray preventive paint.

[0002]

2. Description of the Related Art Ultrafine titanium dioxide having a single particle size of about 0.1 μm or less, when incorporated into a resin film or molded product, transmits visible light and thus exhibits transparency. It is well known that it exhibits properties different from those of pigment-grade titanium dioxide having a single particle size of 0.15 to 0.5 μm, such as protection of substances which change color or deteriorate by ultraviolet rays. For this reason, utilization as a sunscreen cosmetic for making use of natural skin color and preventing sunburn due to ultraviolet rays has recently attracted particular attention. However,
Conventionally, commercially available ultrafine titanium dioxide has a strong cohesive force, and it is difficult to completely disperse the primary particles in an aqueous or oily medium.For example, a sunscreen cosmetic containing ultrafine titanium dioxide is used. When applied to the skin, it often has the disadvantage of causing strong scattering of bluish shades, giving bluish tones and, thus, making the skin look unhealthy. Further, the conventional ultrafine titanium dioxide sufficiently shields the light beam having the wavelength in the ultraviolet B region (wavelength 320 to 290 nm), but the light beam having the wavelength in the ultraviolet A region (wavelength 380 to 320 n).
m) is insufficiently shielded, and in recent years, skin damage due to ultraviolet rays in the A region has become a problem. For this reason, it is a fact that organic ultraviolet absorbers and the like are used in combination.

As ultrafine titanium dioxide which significantly improves the above problem, the present inventors have used a fine titania sol having a rutile nucleus as a base material, and neutralized a water-soluble salt of iron in the presence of the fine titania sol. Precipitating and coating the surface of titania with hydrated iron hydroxide, and then sintering at 300 to 850 ° C to obtain an iron-containing ultrafine titanium dioxide and an acidic aqueous solution of a titanium salt and an acidic aqueous solution of an iron salt in the presence of an alkaline substance , And thereafter, an iron-containing ultrafine titanium dioxide obtained by calcining the hydrolysis product at 300 to 800 ° C. was proposed (Japanese Patent Application No. 4-170256).

[0004] However, the present inventors have reported that the above-mentioned iron-containing ultrafine titanium dioxide has undergone a baking and drying process, and that some of the iron-containing ultrafine titanium dioxide is strongly agglomerated. Even when trying to prepare, especially in the preparation of cosmetics and the like, applying strong dispersing energy is disliked because it may impair the properties of the blended composition, and therefore has sufficient ultraviolet shielding ability I haven't gotten it. In addition, when a conventional dispersion of ultrafine titanium dioxide is used, a specific bluish tone is easily emphasized, and use in the cosmetics field is particularly disliked.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an ultra-fine iron-containing titanium dioxide having an excellent feature of not giving a bluish color tone, when it is blended into cosmetics and paints by a relatively simple dispersion treatment operation. An object of the present invention is to provide a dispersion which can be blended with a high degree of dispersion and can impart a very excellent ultraviolet shielding ability.

[0006]

Means for Solving the Problems The present inventors have studied various forms of ultrafine iron-containing titanium dioxide which fully exhibit the inherent ultraviolet shielding ability when blended in cosmetics and paints. . As a result, in a medium suitable for the system to be blended, if the form is well dispersed in advance using a dispersing agent, in addition to solving any of the above problems, the stability of the blended system It has been found that the present invention has excellent effects not found in the prior art, such as improvement and improvement in use feeling such as good elongation when blended in cosmetics, and completed the present invention. The iron-containing ultrafine titanium dioxide dispersion of the present invention comprises a medium suitable for the system to be blended, iron-containing ultrafine titanium dioxide, and a dispersant for dispersing the particles.

[0007] The aqueous dispersion is mixed with 30 to 70 parts by weight of iron-containing ultrafine titanium dioxide, preferably 40 to 70 parts by weight.
Parts by weight and the dispersant are 0.5 to 10% by weight as a dispersant / iron-containing ultrafine titanium dioxide, and 30 to 70 parts by weight, preferably iron-containing ultrafine titanium dioxide, as an oil dispersion. 40 to 70 parts by weight, and the dispersant is 1 to 30% by weight as the dispersant / iron-containing ultrafine titanium dioxide.

[0008] The iron-containing ultrafine titanium dioxide in the iron-containing ultrafine titanium dioxide dispersion of the present invention has an average single particle diameter of 0.01 to 0.1 µm, and the iron component is contained in the crystal in the form of TiO in terms of Fe. 1 to 30% by weight based on ₂ .

The ultrafine titanium dioxide containing iron is, for example, using a fine titania sol having a rutile nucleus as a base particle, and precipitating and coating an oxide of iron or a hydrated oxide on the surface of the titania, followed by firing, Obtained by grinding. Further, for example, it can also be obtained by hydrolyzing an acidic aqueous solution of a titanium salt and an acidic aqueous solution of an iron salt in the presence of an alkali, and then calcining and pulverizing the obtained hydrolysis product precipitate. This iron-containing ultrafine titanium dioxide has a solid solution of iron component inside the crystal,
Even when blended into cosmetics or paints under strong dispersion conditions, color separation between the iron component and titanium dioxide does not occur, and the ability to block the ultraviolet A region is remarkably improved. Have.

The medium in the iron-containing ultrafine titanium dioxide of the present invention may be selected according to the cosmetics and paints to be blended. This medium may belong to any of water, vegetable oil, animal oil, mineral oil and silicone oil, but those having a viscosity of more than 1000 cp have a certain degree of fluidity in the pulverization step in the production of the dispersion. It is not preferable because it is necessary.

The dispersant in the iron-containing ultrafine titanium dioxide of the present invention is desirably soluble in a medium and compatible with cosmetics and paints to be blended. If the medium is water, a condensed phosphoric acid compound, a polycarboxylic acid compound,
Amino acid compounds, polyoxyethylene alkyl ethers, amino alcohols and the like are used as dispersants. When the medium is oil, polyoxyethylene alkyl ether, sorbitan fatty acid ester, polyoxyethylene alkyl phosphate, fatty acid alkanolamide, polyether modified silicone oil, silicone resin and the like are used as dispersants. These dispersants need not be limited to one kind, and two or more kinds may be used in combination. Further, a preservative, for example, alkyl parabens, and the like, and an antifoaming agent, for example, a silicon compound and a surfactant can be added as needed.

[0012] The iron-containing ultrafine titanium dioxide in the iron-containing ultrafine titanium dioxide dispersant of the present invention contains aluminum, ultrafine titanium dioxide for improving the affinity with the dispersant, the weather resistance and the like.
The surface may be coated with an oxide or hydroxide of titanium, zirconium, silicon, zinc, tin, or the like. Further, it may be coated with various organic treating agents used in the field of cosmetics and paints, for example, at least one kind of organic substances such as carboxylic acids, polyols, amines, siloxane compounds and silane coupling agents. In that case, the dispersibility in cosmetics and paints and the durability of the coating film can be further improved.

Next, a method for producing the dispersion of the present invention will be described. The dispersion of the present invention is a specific dispersant, a medium solution and iron-containing ultrafine titanium dioxide are premixed using a blade-type stirrer, a disper, a homomixer, etc. It is obtained by dispersing iron-containing ultrafine titanium dioxide. The type of crusher, selection of crushing media, and setting of optimum crushing conditions are important in preparing an advanced dispersion. For example, a vertical or horizontal sand mill with a diameter of 0.5 mm is used.
It is preferable to use zirconia beads of mm.

It is important to perform the pre-mixing uniformly and in a short time in view of the quality and productivity of the finally obtained dispersion, and for that purpose, it is necessary to select a mixing method suitable for the properties of the dispersant. There is. If the dispersant is easily soluble in the medium, it is preferable to dissolve the dispersant in the medium in advance, and then add and mix the iron-containing ultrafine titanium dioxide particles. If the dispersing agent is a hardly soluble powder, it is preferable to dry-mix the dispersing agent and the iron-containing ultrafine titanium dioxide powder in advance, and then put the mixture into a medium and mix.

In the case where the medium is water, the iron-containing ultrafine titanium dioxide may be a cake before finishing and drying in the middle of the process. In this case, strong agglomeration due to drying can be avoided, and the pulverizing step at the time of manufacturing the dispersion can be simplified.

The iron-containing ultrafine titanium dioxide dispersion thus obtained contains the iron-containing ultrafine titanium dioxide in a very well dispersed state. In addition to sufficiently exhibiting the ultraviolet shielding ability, it exhibits the effect of improving the stability of the compounded system and, in the case of cosmetics, improving the usability such as good elongation.

The iron-containing ultrafine titanium dioxide dispersion is prepared under conditions very suitable for dispersing the iron-containing ultrafine titanium dioxide, and then blended into a desired system. Be demonstrated. In contrast,
Even if iron-containing ultrafine titanium dioxide is mixed in such a way that powder is mixed into cosmetics and paints, the inherent ultraviolet shielding ability is often not sufficiently exhibited. When utilizing the iron-containing ultrafine titanium dioxide dispersion of the present invention as a sunscreen cosmetic, for example, an oily component, a humectant, a surfactant,
It can be mixed with pigments, fragrances, preservatives, water, alcohols, thickeners and the like, and used in various forms such as lotions, creams, pastes, sticks, and emulsions.

When used as a coating for preventing ultraviolet rays, for example, polyvinyl alcohol resin, vinyl chloride-vinyl acetate resin, acrylic resin, epoxy resin, urethane resin, alkyd resin, polyester resin, ethylene-vinyl acetate copolymer, acryl-styrene It is mixed with a copolymer, a cellulose resin, a phenol resin, an amino resin, and the like, and dispersed in water or a solvent.

Although the iron-containing ultrafine titanium dioxide dispersion of the present invention is useful for various sunscreen cosmetics and UV protection paints as described above, wood paints for UV protection have recently attracted attention and are becoming popular. It is also suitable.

[0020]

Example 1 While maintaining an aqueous solution of titanium tetrachloride at a concentration of 200 g / l as TiO ₂ at room temperature, an aqueous solution of sodium hydroxide was added to adjust the pH to 7.0, and the colloidal amorphous Hydrous titanium oxide was precipitated and subsequently aged to obtain a rutile-type titania sol. After thoroughly washing this sol, TiO
₂ was used as a hydrous titanium oxide aqueous slurry having a concentration of 200 g / l. This slurry was heated to 70 ° C., and with good stirring, 7% by weight of Fe relative to TiO ₂ was contained therein.
Ferrous sulfate aqueous solution (Fe concentration 50 g / l) was added over a period of 30 minutes, and a sodium hydroxide solution was added over a period of 40 minutes to adjust the pH to 9 and water was added to the surface of the hydrous titanium oxide particles. The iron oxide was precipitated and coated. After aging for 60 minutes, the mixture was filtered and washed. 600 ° C of the obtained washed cake
For 3 hours, dispersed in water, and wet-ground with a sand mill to obtain a slurry of ultrafine titanium dioxide.

The slurry is heated to 70 ° C., and while stirring well, a 2.0% by weight aqueous solution of aluminum sulfate as Al ₂ O _{3 with} respect to TiO ₂ is added thereto over 30 minutes. Add sodium hydroxide solution,
The pH was adjusted to 7.0, and the hydrated alumina was precipitated and coated.

After that, aging for 60 minutes, filtration and washing,
After drying, the powder was pulverized with a fluid energy mill to obtain ultrafine iron-containing titanium dioxide having an average single particle diameter of 0.04 μm by electron micrograph.

After 50 parts by weight of the iron-containing ultrafine titanium dioxide and 1 part by weight of sodium hexametaphosphate were mixed in a mortar, the mixture was added to 49 parts by weight of purified water and mixed with a disper. Next, when this was pulverized with a sand mill using zircon beads as a pulverizing medium, the viscosity was 95 cP,
An aqueous dispersion (A) having a pH of 8.2 was obtained.

Comparative Example 1 The iron-containing ultrafine titanium dioxide of Example 1 was used as a powder (B).

Example 2 45 parts by weight of the dried and ground powder before the preparation of the aqueous dispersion of Example 1 was mixed with 15 parts by weight of a dispersant (trimethylsiloxysilicic acid) and 40 parts by weight of a dispersion medium (octamethylcyclotetrasiloxane). The mixture was mixed using a disper. next,
This was pulverized with a sand mill using zircon beads as a pulverizing medium to obtain a silicon oil dispersion (C) having a viscosity of 100 cP.

[0026]

[Test example]

Test Example 1 A sunscreen cream (O / W emulsion) (a) was prepared by blending the iron-containing ultrafine titanium dioxide aqueous dispersion (A) and the powder (B) in the following formulation so that the total amount would be 100 parts by weight. ) And (b) were obtained. (1) 2.5 parts by weight of stearic acid (2) 3.5 parts by weight of beeswax (3) 3.5 parts by weight of cetanol (4) 17.0 parts by weight of squalane (5) 3.0 parts by weight of glycerin monostearate (6) Ultrafine titanium dioxide aqueous dispersion (A) 6.0 parts by weight or ultrafine titanium dioxide powder (B) 3.0 parts by weight (7) Methylparaben 0.1 parts by weight (8) Glycerin 12.0 parts by weight (9) 1.0 part by weight of triethanolamine (10) Remaining purified water (11) 0.3 part by weight of fragrance Components (1) to (6) obtained by heating and mixing at 80 ° C. are mixed with components (7) to ( 10) is added to the mixture obtained by heating at 80 ° C., mixed well with a homomixer, and stirred vigorously. 45 ° C
In the vicinity, (11) was added to prepare a sunscreen cream.

Test Example 2 A sunscreen cream (W / W) was prepared by blending a silicon oil dispersion (C) and a powder (B) of iron-containing ultrafine titanium dioxide in the following formulation so that the total amount would be 100 parts by weight. O emulsion) (c) and (d) were obtained. (1) Octamethylcyclotetrasiloxane balance (2) Dimethylpolysiloxane 15.7 parts by weight (3) Polyoxyethylene-modified dimethyl 0.5 parts by weight polysiloxane (4) Ultrafine titanium dioxide dispersion (C) 6.7 Parts by weight or ultrafine titanium dioxide powder (B) 3.0 parts by weight (5) Nylon powder (particle diameter 5 μm) 12.5 parts by weight (6) ethanol 10.0 parts by weight (7) glycerin 2.5 parts by weight ( 8) Purified water 27.5 parts by weight To components obtained by mixing components (1) to (5) and dispersing them with a disper, gradually add a mixture of components (6) to (8) mixed in advance while stirring. A sunscreen cream was prepared.

Evaluation Method 1 Each of the above creams was applied on quartz glass so as to have a thickness of 25 μm, and the transmittance at 750 to 300 nm was measured with a spectrophotometer.

Evaluation Method 2 Each of the above creams was commonly used by 10 women aged 20 to 52 years, and the use feeling of good stretch on the skin was mutually evaluated. Table 1 shows the above evaluation results.

[0030]

[Table 1]

[0031]

The iron-containing ultrafine titanium dioxide dispersion obtained by the present invention, when blended in cosmetics, paints, etc., can sufficiently exhibit the ultraviolet shielding ability of the iron-containing ultrafine titanium dioxide. When blended in cosmetics, it is possible to impart more excellent effects such as a healthy skin tone with reduced blueness, a feeling of use, and stability.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-48-67196 (JP, A) JP-A 64-7941 (JP, A) JP-A 64-3020 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) A61K 7/02 A61K 7/42 C01G 23/053 C09C 1/36 C09D 5/33

Claims (7)

(57) [Claims] [Claim 1 wherein] in water as a dispersion medium, 30 to 70 parts by weight of iron-containing ultrafine titanium dioxide and dispersing agents 0.15
7-A aqueous dispersion containing parts, iron-containing titanium dioxide, the titania fine titania sol comprising rutile nuclei
Precipitate and coat iron oxide or hydrated oxide on the surface ,
It is then calcined and pulverized and has an average single particle size of 0.1.
And the iron component is Fe
In that it contains 1 to 30 wt% with respect to TiO2 in terms of
An iron-containing ultrafine titanium dioxide dispersion. Wherein in oil as a dispersion medium, 0.3 to 30 to 70 parts by weight and a dispersant iron containing ultrafine titanium dioxide
21 be an oil dispersion comprising parts, iron-containing titanium dioxide, the titania fine titania sol comprising rutile nuclei
Precipitate and coat iron oxide or hydrated oxide on the surface ,
It is then calcined and pulverized and has an average single particle size of 0.1.
And the iron component is Fe
In that it contains 1 to 30 wt% with respect to TiO2 in terms of
An iron-containing ultrafine titanium dioxide dispersion. 3. The iron-containing ultrafine titanium dioxide dispersion according to claim 2, wherein the oil as the dispersion medium is a silicone oil. 4. A sunscreen cosmetic comprising the iron-containing ultrafine titanium dioxide dispersion of claim 1 or 2. 5. An anti-ultraviolet coating comprising the iron-containing ultrafine titanium dioxide dispersion of claim 1 or 2. 6. Dispersant 0.15 to water as a dispersion medium
Titan of fine titania sol having 7 parts by weight and rutile nucleus
Precipitation of iron oxide or hydrated oxide on the near surface , Coating
And then calcined and crushed to obtain the average single particle size
It has a thickness of 0.01 to 0.1 μm, and contains an iron component inside the crystal.
Iron containing 1 to 30% by weight of TiO2 in terms of Fe
30-70 parts by weight of ultrafine titanium dioxide
After that, the iron-containing ultrafine titanium dioxide is
The iron-containing composition according to claim 1, wherein the composition is dispersed.
Method for producing ultrafine titanium dioxide dispersion. 7. Dispersant 0.3 to 2 in oil as dispersion medium
1 part by weight and rutile nucleus Of titania sol with fine titania
Precipitation of iron oxide or hydrated oxide on the near surface , Coating
And then calcined and crushed to obtain the average single particle size
It has a thickness of 0.01 to 0.1 μm, and contains an iron component inside the crystal.
Iron containing 1 to 30% by weight of TiO2 in terms of Fe
30-70 parts by weight of ultrafine titanium dioxide
After that, the iron-containing ultrafine titanium dioxide is
3. The iron-containing composition according to claim 2, wherein the composition is dispersed.
Method for producing ultrafine titanium dioxide dispersion.