JP2002080823A - Ultraviolet ray insulating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet ray insulating agent effective for insulating an UV-A ultraviolet ray. SOLUTION: This ultraviolet ray insulating agent comprises particles having a band gap energy of 2.5-3.2 eV and an average particle diameter in the range of 1-500 nm. The particle comprises inorganic oxides, and prepared especially by compounding 0.005-30 mol% of at least one selected from the group consisting of titanium oxide, zinc oxide, iron oxide, aluminum oxide, nickel oxide, and cobalt oxide to potassium oxide, and it is a solid solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet ray blocking agent incorporated in cosmetics, films, plastics, paints and the like. More specifically, cosmetics for cosmetics such as emulsions, creams, lotions, foundations, compact powders, nail varnishes, lipsticks, eye shadows, lotions, hair styling products, lighting covers, electronic substrates and electric and electronic materials such as EL , Automotive parts such as interior panels for automobiles, machine parts, packaging and containers for food and medicine, textiles, signs, steel plates, plastic plates, sheets, agricultural coating materials, roofs,
Films, plastics, paints used for outdoor structures such as tents and outdoor warehouses, automobiles, vehicles, ships, aircraft, household appliances, machinery, building exterior walls, bridges, office supplies, eyeglass lenses, toys, sundries, etc. Provided is an ultraviolet ray blocking agent for preventing deterioration of the product.

[0002]

2. Description of the Related Art Ultraviolet rays contained in sunlight have
280 nm UV-C, 280-320 nm UV-
B, there is 320-400 nm UV-A. this house,
UV-C is absorbed by the ozone layer and does not reach the surface of the earth. However, UV-B and UV-A ultraviolet rays not only degrade and erode organic materials such as films and plastics, discoloring, lowering gloss, cracking and embrittlement, but also have an adverse effect on living organisms. strong. As one of the prevention methods, various organic and inorganic ultraviolet ray blocking agents have been developed.

[0003] Organic ultraviolet blocking agents such as benzophenone, paraaminobenzoic acid, salicylic acid, cinnamic acid, benzotriazole and cyanoacrylate are compounded in films, plastics, paints and cosmetics. Although most of these organic compounds function effectively for UV-B, very few of them are effective for UV-A.

On the other hand, as the inorganic ultraviolet blocking agent, metal oxides such as titanium oxide, zinc oxide, iron oxide, cerium oxide, zirconium oxide and aluminum oxide have been conventionally used. However, for example, titanium oxide is
Although it shows an effective ultraviolet ray blocking effect for ultraviolet rays in the V-B region, the effect is not sufficient for ultraviolet rays in the UV-A region. Zinc oxide has high transparency and UV-A
Although it has an effective ultraviolet light blocking effect for ultraviolet light in the region, there is a problem that the light shielding effect is not sufficient for ultraviolet light in the UV-B region.

[0005] As a solution to these problems, there have been proposed a large number of fine particles or composites of the above-mentioned metal oxides. UV rays are blocked efficiently,
It is impossible to completely block ultraviolet rays in the UV-A region, especially ultraviolet rays having a wavelength of 380 nm or more.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems found in the conventionally proposed ultraviolet ray blocking agents, and to efficiently block ultraviolet rays, especially ultraviolet rays in the UV-A region, and an ultraviolet ray blocking agent therefor. It is to provide a manufacturing method.

[0007]

In order to solve the above-mentioned problems, the ultraviolet blocking agent of the present invention has a band gap in the range of 2.5 to 3.2 eV and an average particle diameter of 1 to 3. It is characterized in that the fine particles are in the range of up to 500 nm. According to this configuration, the ultraviolet ray blocking effect is efficiently exhibited by the absorption of the ultraviolet ray due to the transition between the band gaps and the increase in the effective sectional area due to the atomization. Further, by setting the average primary particle diameter to 1 to 500 nm, it becomes possible to cope with the case where light scattering is required in the visible light region and the case where transparency is required on the contrary.

The fine particles constituting the above-mentioned ultraviolet ray blocking agent may be of any type as long as they have a band gap in the range of 2.5 to 3.2 eV and an average particle size in the range of 1 to 500 nm. In consideration of heat resistance, weather resistance, and safety in daily use, an inorganic compound is preferably used, and an inorganic oxide is more preferably used.

The inorganic oxide is not particularly limited as long as it satisfies the above-mentioned conditions, and is not limited. For example, cerium oxide, titanium oxide, zinc oxide, zirconium oxide, yttrium oxide,
Lanthanum oxide, gadolinium oxide, lutetium oxide, silicon oxide, magnesium oxide, tungsten oxide, tin oxide, iron oxide, aluminum oxide, nickel oxide, cobalt oxide, barium titanate, strontium titanate, calcium titanate, barium cerium, cerium One or more oxides selected from strontium acid, calcium cerate and lanthanoid aluminum oxide are preferably used.

In addition, one or more oxides selected from titanium oxide, zinc oxide, iron oxide, aluminum oxide, nickel oxide and cobalt oxide are added to cerium oxide.
The 005 to 30 mol% compounded particles are more preferably used because they have a greater effect of blocking not only ultraviolet rays in the UV-B region but also ultraviolet rays in the UV-A region. Zinc oxide,
Particles in which one or more oxides selected from iron oxide, nickel oxide, and cobalt oxide are dissolved are particularly preferably used because the above-mentioned ultraviolet shielding effect is further enhanced.

In particular, particles obtained by compounding cerium oxide with titanium oxide in an amount of 0.005 to 30 mol% are more preferably used because the effect of blocking ultraviolet rays is further increased. By doing so, the band gap can be controlled by the amount of solid solution, and an extremely high ultraviolet blocking effect can be obtained. Here, the compounding amount of the oxide compounded with cerium oxide is 0.005 mol%.
If it is smaller than that of cerium oxide alone, there is no significant difference in the ultraviolet ray blocking effect,
If it exceeds 30 mol%, it becomes extremely difficult to form a solid solution with cerium oxide.

Further, the surface of the ultraviolet ray blocking agent of the present invention is coated with one or more kinds of various surface treating agents and amorphous and / or crystalline inorganic compounds, and is used for cosmetics, films, plastics and paints. It often prevents or suppresses photo / thermal catalytic activity, imparts water repellency / hydrophilicity, prevents coagulation, improves dispersibility, improves usability, and adjusts colors, which are often problems when compounding into May go.

As the surface treatment agent at this time, for example,
Polyols such as pentaerythritol and trimethylolpropane, alkanolamines such as triethanolamine acetate, silicones such as methylhydrogenpolysiloxane, dimethylpolysiloxane, trimethylsiloxysilicate, and metal soaps such as aluminum stearate And various surface treatment agents can be used.

[0014] In addition, the irregular shape covering the surface of the particles and / or
Or, as the crystalline inorganic compound, any compound may be used as long as it is chemically stable, and is not particularly limited.
For example, barium, calcium, magnesium, strontium, silicon, boron, aluminum, gallium,
Iron, copper, silver, nickel, palladium, cobalt, tin,
Molybdenum, tungsten, zirconium, hafnium, zinc, titanium, manganese, vanadium, niobium, tantalum, antimony, bismuth, germanium, scandium, yttrium, oxides, hydroxides and composite oxides of rare earth elements having atomic numbers 57 to 71 Or composite hydroxide,
One or more amorphous or crystalline compounds selected from nitrides, oxynitrides, carbides, carbonates, and oxycarbonates can be used.

Among the inorganic compounds, for example, zinc oxide has a band gap of about 3.2 eV, titanium oxide has a band gap of about 3.0 eV for rutile type and about 3.2 eV for anatase type, and cerium oxide has a band gap of about 3.2 eV. .1 eV. Therefore, if one selected from these is used, there is an effect that the ultraviolet ray blocking effect is increased. Furthermore, if these and other oxides are compounded and / or dissolved in these and the band gap value is adjusted between 2.5 and 3.0 eV, the blocking effect against UV-A ultraviolet rays is further increased. Become.

Further, by forming the above-mentioned ultraviolet ray blocking agent by coating with amorphous or crystalline boron nitride or boron oxynitride, in addition to the ultraviolet ray blocking effect and the effect of suppressing or suppressing the catalytic activity, lubrication, This has the effect of improving dispersibility. Further, when the ultraviolet ray blocking agent is colored, there is also an effect of whitening by coating with the compound. In this case, as the form of boron nitride or boron oxynitride, or a mixture thereof, in addition to amorphous and crystalline forms, bucky onion type particles having a layered structure such as fullerene having a layered structure such as onion are also included. included.

Here, the amorphous in the present invention means an amorphous and / or glass and / or turbostratic structure. By making the inorganic compound layer covering the surface amorphous, there is an effect that the heat treatment temperature at the time of manufacturing can be lowered.

Further, as the mode of surface coating with the ultraviolet ray blocking agent of the present invention, a single compound may be coated in a layer, or a mixture of a plurality of compounds may be coated in a layer. In addition, the coating layer may have one or more layers. In the case of having two or more layers, various surface treatment agents and combinations of inorganic compounds can be arbitrarily set and are not limited at all. The crystalline form of the inorganic compound may be any of crystal, glass and amorphous.

Hereinafter, preferred embodiments of the composite fine particles of the present invention will be described in detail in terms of the band gap energy of the particles.

The fine particles used in the ultraviolet blocking agent of the present invention must have a blocking property in the entire range of UV-A to UV-B ultraviolet rays. Generally, in the case of the inorganic ultraviolet blocking agent as in the present invention, the blocking of the ultraviolet rays is performed by scattering and absorbing the ultraviolet rays.

Light scattering depends on the particle size, and Rayleigh scattering and Mie scattering mainly occur in the particle size range of the ultraviolet blocking agent of the present invention. Mie scattering occurs in a region where the wavelength of light is substantially equal to the particle diameter, and the particle diameter becomes maximum around about 1/2 of the wavelength of ultraviolet light. Therefore, the wavelength 2
In order to protect the ultraviolet light having a wavelength of 80 to 400 nm, the particle diameter may be controlled to 140 to 200 nm. At this time, the effect of scattering increases as the refractive index of the particles increases.

However, when the ultraviolet light of the present invention is blended into cosmetics, films, plastics, paints, and the like that require high transparency, not only ultraviolet light but also visible light can be used in the particle size range where the scattering effect is large. Since light is also scattered, the transparency in the visible light region is impaired as a result.

Accordingly, the particle size of the ultraviolet ray blocking agent is not particularly limited. For example, when transparency is required for cosmetics, films, plastics, paints, etc. containing the ultraviolet ray blocking agent, the ultraviolet ray blocking agent may be used. Particle size of 1 to 500 n
m, preferably 1 to 100 nm, more preferably 1 to 100 nm
The thickness is preferably set to 50 nm. The reason is that if the particle diameter is less than 1 nm, synthesis and handling become extremely difficult, and 50 n
If m exceeds m, scattering becomes large, and it is extremely difficult to obtain transparency to light in the visible light region.

In particular, when the particle size of the ultraviolet ray blocking agent is controlled to about 1/10 or less of the wavelength, that is, 50 nm or less,
Light scattering becomes Rayleigh scattering, and the scattering power is reduced, so that the transparency is significantly improved. However, at the same time, the scattering ability with respect to ultraviolet light is also reduced, so that the effect of scattering with respect to ultraviolet light of 380 nm or more is hardly obtained. Therefore, in such a case, the ultraviolet rays are blocked by absorption.

The absorption of ultraviolet light by the inorganic compound is mainly due to the exciton absorption of the semiconductor compound, and the energy corresponding to this energy is the band gap. Therefore, a compound whose band gap energy is equivalent to a wavelength in the ultraviolet light region exhibits its properties effectively.

That is, since the valence band and the conduction band are not continuous, the semiconductor compound absorbs light having a wavelength corresponding to energy equal to or greater than the band gap energy, which is the energy difference between the two levels. For example, zinc oxide has a band gap energy of 3.2 eV and absorbs light having a wavelength of 390 nm or less. The property of the inorganic ultraviolet shielding agent absorbing ultraviolet light is that its band gap energy is in the wavelength region of ultraviolet light.

However, since the band gap corresponds to the wavelength at which absorption starts, when an ultraviolet-visible absorption spectrum is measured, although light having a wavelength corresponding to the band gap energy is actually absorbed to some extent,
Not completely absorbed. Then, as the wavelength becomes shorter than the wavelength of the light corresponding to the band gap, the absorption gradually increases, and eventually complete absorption occurs.

Therefore, in order to completely block UV-A, which is long-wavelength ultraviolet light, it is necessary to make the band gap energy smaller than 3.2 eV and completely absorb light having a wavelength of 400 nm or less. From these points, in the ultraviolet ray blocking agent of the present invention, the band gap energy of the fine particles is preferably 2.5 to 3.2 eV. Here, if the band gap is smaller than 2.5 eV, the absorption of the powder extends to the visible light region, so that the coloring becomes strong, and the compounding in cosmetics, films, plastics, paints and the like is restricted. Therefore, it is not preferable.

[0029]

According to the present invention, the ultraviolet blocking agent is formed into fine particles having a band gap in the range of 2.5 to 3.2 eV and an average particle size in the range of 1 to 500 nm. The present invention solves the problems found in the conventionally proposed ultraviolet screening agents, and provides an ultraviolet screening agent that efficiently blocks ultraviolet light, particularly ultraviolet light in the UV-A region. Hereinafter, the present invention will be described specifically.

The ultraviolet blocking agent according to the present invention has a property of substantially blocking light transmission in the ultraviolet region over almost the entire range from the UV-B to the UV-A region.

In the above characteristics, "UV-B to UV-B
The term "substantially blocks the transmission of light in the ultraviolet region over substantially the entire region A" means not only the case where light in the ultraviolet region having a wavelength of 280 to 400 nm is completely blocked but also the light blocking ratio of light in the ultraviolet region. At least 60% or more, preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more.

The form of the ultraviolet blocking agent particles obtained in the present invention is not particularly limited, and the form of the particles can be changed and synthesized according to the intended use, such as spherical, acicular, columnar, polyhedral, porous and hollow. Although it is possible, it is desirable to use spherical particles or spherical hollow particles for the purpose of improving dispersibility and uniformity.

The ultraviolet blocking agent of the present invention can be easily produced by the following known production methods. That is, precipitation method (coprecipitation method), uniform precipitation method, hydrothermal synthesis method, hydrolysis method,
Liquid phase method such as alkoxide method, microemulsion method, emulsion method, spray pyrolysis method, gas phase method such as chemical vapor transport method, sputtering method, gas evaporation method, laser synthesis method, gas phase reaction method, raw material Powders can be produced by various methods such as a solid phase method in which powders are mixed and heated and fired in a non-oxidizing or oxidizing atmosphere to react.

Of the methods described in the preceding paragraph, those which are relatively easy to synthesize and easy to mass-produce are preferably used, in particular, a precipitation method (coprecipitation method) which is advantageous for fine particle synthesis,
A hydrothermal synthesis method, an alkoxide method, a gas evaporation method, and a spray pyrolysis method are preferably used. For example, precipitation method (coprecipitation method)
Is to add a precipitant such as aqueous ammonia to an aqueous solution of an inorganic compound salt to precipitate a precipitate. In the hydrothermal synthesis method, a raw material is dissolved in a solvent such as water, or a precipitate obtained by a precipitation method is dispersed in a solvent and then heated in a pressure vessel to cause a reaction or crystallization. The alkoxide method hydrolyzes an alcohol solution of a metal alkoxide. In the gas evaporation method, metal powder is instantaneously evaporated in an inert gas, and the generated ultrafine metal particles are reacted with oxygen, nitrogen, ammonia, hydrogen gas or the like. In the spray pyrolysis method, an aqueous solution of a metal salt or the like is sprayed into a high-temperature atmosphere, and is immediately decomposed and fired. Subsequently, the particles obtained by these methods and the like are washed and dried as necessary.
If necessary, the ultraviolet ray blocking agent is obtained by baking in a non-oxidizing or oxidizing atmosphere.

Examples of the raw material of the inorganic compound include metal hydroxides, carbonates, acetates, citrates, borates, nitrates, chlorides, sulfates, ammonium nitrates, citric acid, and boric acid. , Urea, oxalic acid, alkoxide, acetylacetonato complex, and various organometallic compounds are used.

Examples of the precipitant include water,
Oxalic acid, boric acid, ammonium oxalate, ammonia, sodium hydroxide, potassium hydroxide, ammonium carbonate, sodium hydrogen carbonate, urea, water or alcohol solutions of sodium carbonate, ammonia gas, carbon dioxide gas, hydrogen sulfide gas, etc. are used. .

Examples of the solvent include water, alcohols having 1 or more carbon atoms and various organic solvents such as methanol, ethanol, propanol, isopropanol, butanol, hexanol, hexane, cyclohexane, ligroin,
Pentane, cyclopentane, benzene, toluene, phenol, tetrahydrofuran, pyridine, diethyl ether, acetone, and mixtures thereof can be used, but preferably inexpensive and easily available water is used.

An ultrasonic dispersing apparatus is usually used for dispersing the above-mentioned ultraviolet ray blocking particles, but in addition, a stirrer such as a magnetic stirrer or a homogenizer may be used. When the solvent is evaporated, drying using a constant temperature drier, a rotary evaporator, or the like, or freeze drying or supercritical drying may be performed in addition to natural evaporation and heating evaporation.

The above particles can be washed with water, hydrocarbon, alcohol, acetone, petroleum ether or the like. The washing means may be a centrifugal separation, filtration and decantation, or a fine powder washing apparatus using a ceramic filter or an ultrafiltration membrane. The particles are dried by natural drying at room temperature or by heating and drying using an oven or the like. At this time, a vacuum drying device, a freeze drying device, a spray dryer, or the like may be used.

The non-oxidizing atmosphere means, for example, a gas atmosphere of nitrogen, hydrogen, chlorine, ammonia, hydrogen sulfide, argon, helium, or the like, or a vacuum. 0.01 for total pressure
% Is desirable. On the other hand, the oxidizing atmosphere is
For example, oxygen, air, and a gas atmosphere containing these are meant. The treatment temperature at this time can be any temperature in the range of room temperature to 1000 ° C., but it is preferable to perform the treatment at room temperature to 600 ° C. in order to suppress aggregation and growth of particles. In addition, at room temperature or lower, the reaction rate cannot be decreased or the activation energy required for the reaction cannot be exceeded,
The production efficiency of the intended ultraviolet ray blocking agent particles is remarkably reduced, while at 600 ° C. or higher, sintering and grain growth between the particles occur.

The above-mentioned firing treatment is performed in a non-oxidizing or oxidizing atmosphere. However, when firing is performed in a non-oxidizing atmosphere, the firing may be performed again in an oxidizing atmosphere. The firing temperature at this time is from room temperature to 700 ° C., preferably from room temperature to 30 ° C.
0 ° C., the heating rate is 500 ° C./hour or less, preferably 100 ° C./hour, and the firing time is 30 minutes to 12 minutes.
Time, preferably 1 to 3 hours. It can be said that it is preferable to set upper and lower limits of the firing temperature, the firing time, and the heating time so that aggregation, grain growth, and sintering due to the firing process do not easily occur.

When the surface of the ultraviolet ray blocking agent of the present invention is coated, the amount of the substance to be coated on the surface can be adjusted to an arbitrary ratio with respect to the ultraviolet ray blocking agent fine particles by changing the mixing ratio of raw materials, the reaction temperature and the reaction time. Can be controlled by
Although not particularly limited, it is desirable to adjust the molar fraction of the surface coating substance in the obtained composite particles to be 1 to 50 mol%. The reason is that selecting a mole fraction of 50% or more makes it difficult to obtain a high ultraviolet blocking effect, while selecting a mole fraction of 1% or less suppresses catalytic activity and improves lubricity. This is because it is difficult to improve the image quality and adjust the color.

When the surface of the ultraviolet ray blocking agent of the present invention is coated, the thickness of the material for coating the surface may be, for example, the concentration of the raw material,
It varies depending on the reaction temperature, reaction time, type of the substance to be coated, and the like. The thickness is not particularly limited, but is preferably adjusted to 0.1 to 20 nm in order to simultaneously achieve a high ultraviolet blocking effect, suppression of catalytic activity, and excellent lubricity.

In this way, it is possible to easily obtain an ultraviolet ray blocking agent which substantially blocks the transmission of ultraviolet rays from substantially the entire region from the UV-B to the UV-A region, and in particular, efficiently blocks ultraviolet rays in the UV-A region. Can be.

The application of the ultraviolet ray blocking agent according to the present invention is not particularly limited, and it can be used in any application which needs to block ultraviolet rays. It can be used for films, UV-resistant plastics, UV-resistant paints and the like. Among them, it is suitably used for sunscreen cosmetics and films for preventing UV deterioration.

If the ultraviolet ray blocking agent of the present invention is incorporated into, for example, cosmetics, films, plastics, paints, etc.,
It shows an excellent ultraviolet blocking effect over almost the entire region from VB to UV-A.

The blending amount of the ultraviolet ray blocking agent at this time is not particularly limited, but is preferably 0.1 to 80% by weight.
Is blended. When the amount is less than 0.1% by weight, it is difficult to substantially provide the ultraviolet ray blocking ability. On the other hand, when the content exceeds 80% by weight, the ultraviolet ray shielding ability is too high. This is because the UV-blocking agent is not used effectively because it is added excessively, and the raw material is wasted.

Further, the ultraviolet ray blocking agent of the present invention can be used in the form of particles as it is, for example, in cosmetics, films, plastics, paints, etc., as well as in various forms such as pastes, slurries, and dispersions. It can be formulated in a form.

The cosmetic containing the ultraviolet blocking agent of the present invention has high transparency and exhibits an excellent ultraviolet blocking effect. As the dosage form of the cosmetic, for example, it can be used for emulsions, creams, lotions, foundations, compact powders, nail varnishes, lipsticks, eye shadows, lotions, hair stylings, etc., and is preferably used as a sunscreen cosmetic.

Further, when blended in cosmetics, the ultraviolet blocking agent of the present invention may be further subjected to a surface treatment as long as its effect is not impaired. As the surface treatment, for example, amino acid treatment, collagen treatment, lecithin treatment, triglyceride treatment, silicone treatment, metal soap treatment,
And chitin / chitosan treatment.

When the ultraviolet ray blocking agent of the present invention is used in cosmetics, for example, dispersants, surfactants, oils, gelling agents, polymers, humectants, cosmetic ingredients, pigments, preservatives, powders, fragrances, etc. Can be used as long as the effects of the present invention are not impaired.

Also, by blending the ultraviolet ray blocking agent according to the present invention into a film and using it for surface protection, an adhesive, a plastic plate,
Wood boards, steel sheets, and coloring agents such as dyes and pigments can be used for a long period of time because they are protected from ultraviolet rays.

Further, examples of plastics, films and paints containing the ultraviolet blocking agent according to the present invention include:
Electric and electronic materials such as lighting covers, electronic substrates and EL,
Automotive parts such as interior panels for automobiles, mechanical parts, packaging and containers for food and medicine, textiles, signs, steel plates, plastic plates, sheets, agricultural covering materials, rooftops, tents and outdoor structures such as outdoor warehouses, automobiles, Vehicles, ships, aircraft,
Examples include household appliances, machinery, building exterior walls, bridges, office supplies, eyeglass lenses, toys, sundries, etc., but any film, plastic, or paint that requires ultraviolet blocking properties It can also be used for other purposes.

As a resin which is a raw material of the plastic, the film and the paint, a thermoplastic resin or a thermosetting resin is used. Examples of the thermoplastic resin include a fluorine-containing resin, an acrylic resin, a polyamide resin, a vinyl chloride resin, a polycarbonate resin, an olefin resin, an epoxy resin, a polyacetal resin, a polyester resin, a polyetherimide resin, a polyethersulfonic acid resin, and a polyether. Ether ketone resin, polyphenylene sulfide resin, polysulfone resin, polyarylate resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polymethylpentene resin, ABS resin, vinyl acetate resin, polyethylene resin, etc. Preferred are moldable fluorine-containing resins, acrylic resins, polyamide resins, polycarbonate resins, and polyester resins.

Further, as the thermosetting resin, for example, melamine resin, phenol resin, urea resin, furan resin, alkyd resin, unsaturated polyester resin, diallyl phthalate resin, epoxy resin, silicon resin, polyurethane resin, polyimide resin, polyparaban An acid resin or the like is used, and among them, an epoxy resin, a diallyl phthalate resin, and a polyimide resin are preferable.

The paint containing the ultraviolet blocking agent of the present invention is not particularly limited, and any paint may be used. Among the classifications by the coating method, a room temperature dry paint and a baking paint are preferably used.

Further, in addition to the ultraviolet ray blocking agent of the present invention, a small amount of an organic ultraviolet ray absorbing agent is added within a range that does not cause problems caused by its use, such as contamination of products and the environment. By combining the use of an organic ultraviolet ray blocking agent with the organic ultraviolet ray blocking agent, the advantages of both may be used simultaneously. Examples of the organic ultraviolet blocking agent in this case include salicylic acid, benzophenone, benzotriazole or cyanoacrylate, and 4-tert-butyl-4 ′.
-Various ultraviolet blocking agents such as methoxybenzoylmethane. As specific examples, examples of the salicylic acid-based ultraviolet ray blocking agent include octyl salicylate, homomenthyl salicylate, and methyl salicylate. Examples of the benzophenone-based ultraviolet ray blocking agent include hydroxybenzophenone, tetrahydroxybenzophenone, hydroxymethoxybenzophenonesulfonic acid, sodium hydroxymethoxybenzophenonesulfonate, hydroxymethoxybenzophenone, and oxybenzone. As the benzotriazole-based ultraviolet ray blocking agent, 2- (2-hydroxy-5)
-Methylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-butylphenyl) benzotriazole, 2- (2-hydroxy-3-5-ditert-butylphenyl) -5-chlorobenzotriazole and the like. As a cyanoacrylate-based ultraviolet ray blocking agent,
There are 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate, ethyl-2-cyano-3,3-diphenyl acrylate and the like.

[0058]

[Measurement of physical properties] Powder X-ray diffraction measurement of ultraviolet blocking agent (M18XHFSHA, manufactured by Mac Science Co., Ltd.)
) To identify the generated phase, observe the ultrafine particles with a high-resolution transmission electron microscope (H-9000, manufactured by Hitachi, Ltd.), and calculate the average particle diameter as the number average particle diameter of the primary particles. .

The band gap energy E _g of the ultraviolet blocking agent was measured by using an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, UV).
-200 type, with integrating sphere)
Measure the reflection spectrum at 0 nm to determine the absorption coefficient α,
It was calculated from the following relational expression. αhυ = A (hυ−E _g ) ⁿ where h is Planck's constant, υ is the frequency, and A is a constant. n is １ ／ when the band gap transition is a direct type,
In the case of the indirect type, it becomes 2. E _g has hυ on the horizontal axis and (αh
υ) It is obtained from the extrapolation of the linear part obtained by plotting ^{1 / n} on the vertical axis and the intercept of the horizontal axis.

The ultraviolet light blocking property was also measured using an ultraviolet-visible spectrophotometer. Castor oil 5.0 g and clear lacquer 7.0
In 3 g of the mixed solution, 3% by weight of an ultraviolet ray blocking agent is dispersed. This liquid was applied to a transparent quartz plate to a thickness of 40 μm,
The light having a wavelength of 500 nm was continuously irradiated, and the light transmittances at wavelengths of 300 nm and 400 nm were measured.

[0061]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

(Example 1) Isopropyl alcohol 10
A solution obtained by dissolving 1 g of cerium chloride heptahydrate in 0 ml and a solution obtained by dissolving 0.08 g of titanium isopropoxide in 10 ml of isopropyl alcohol were added to 100 ml of 5% aqueous ammonia to obtain a precipitate. Was. Next, the precipitated gel was collected by centrifugation, washed, and dried at 80 ° C. overnight using a thermostatic drier to obtain an ultraviolet ray blocking powder.

When the X-ray diffraction measurement of the thus obtained ultraviolet ray blocking agent powder was performed, as shown in FIG.
Only the diffraction pattern attributed to the cubic fluorite structure was observed. Since a characteristic X-ray of titanium was detected by EPMA analysis and X-ray fluorescence analysis, a solid solution of cerium oxide and titanium oxide was generated.

FIG. 2 shows the results of the measurement of the light reflectance of the ultraviolet ray blocking agent obtained in Example 1. From this figure, it can be seen that the ultraviolet ray blocking agent of the present invention is substantially in the entire region from UV-B to UV-A. It has been found to have excellent absorption capacity over a wide range. Furthermore, the ultraviolet blocking agent obtained in the present invention did not undergo strong aggregation, and was extremely excellent in dispersibility.

(Example 2) The ultraviolet ray blocking agent particles obtained in exactly the same manner as in Example 1 were put into an aqueous solution in which boric acid was dissolved in an amount corresponding to 5.2 times the molar amount of cerium oxide.
After dispersing using an ultrasonic disperser, the solvent was distilled off using a rotary evaporator. After vacuum-drying the obtained powder at 50 ° C.,
Heat treatment was performed at 0 ° C. for 6 hours. Then in the air 5
It was calcined at 00 ° C. for 3 hours, washed 10 times with deionized water and then once with ethanol, and dried naturally to obtain an ultraviolet ray blocking powder.

When the X-ray diffraction measurement of the thus obtained ultraviolet ray blocking agent powder was carried out, it was found that, in addition to the diffraction pattern of a cubic fluorite type structure, boron nitride having a turbostratic structure was obtained at 2θ = 20 to 25 °. A unique diffraction pattern was observed. Further, when observed with a transmission electron microscope, it was observed that the surfaces of the ultraviolet ray blocking agent particles were uniformly covered with amorphous boron oxynitride.

Example 3 To 1 liter of a hydrochloric acid solution in which 5.5 g of titanium tetrachloride and 216 g of cerium chloride heptahydrate were dissolved, 1 liter of 10% aqueous ammonia was added to obtain a precipitate. Next, the precipitated gel was collected by centrifugation, washed, and dried at 80 ° C. overnight using a constant temperature drier to obtain an ultraviolet ray blocking material powder.

When the X-ray diffraction measurement of the thus obtained UV-shielding powder was carried out, as in Example 1, only the diffraction pattern belonging to the cubic fluorite type structure was observed. Since a characteristic X-ray of titanium was detected by EPMA analysis and X-ray fluorescence analysis, a solid solution of cerium oxide and titanium oxide was generated.

[0069]

Comparative Example 1 Comparative Example 1 Using commercially available rutile-type titanium oxide, the band gap energy and the ultraviolet shielding property were evaluated by the methods described in the paragraphs 58 to 60. However, in order to make the visible light transparency almost equal to the ultraviolet light blocking agent obtained in Examples 1 to 3, rutile type ultrafine titanium oxide compounded in a thin film sample for evaluation of ultraviolet light blocking and visible light transparency. Was 1% by weight.

(Comparative Example 2) Using commercially available zinc oxide,
The band gap energy and the ultraviolet blocking property were respectively evaluated by the methods described in the paragraphs 8 to 60. In order to make the visible light transparency substantially equal to the ultraviolet light blocking agent obtained in Examples 1 to 3, the amount of the ultrafine zinc oxide compounded in the thin film sample for evaluating the ultraviolet light blocking property and the visible light transparency was changed. It was 2% by weight.

With respect to the ultraviolet ray blocking agents produced in Examples 1 to 3 and the ultraviolet ray blocking agents of Comparative Examples 1 and 2, the band gap energy and the ultraviolet ray blocking property were evaluated by the methods described in Items 58 to 60, respectively. Table 1 shows the results
Shown in

[0072]

[Table 1]

As described above, the ultraviolet ray blocking agent of the present invention has an excellent effect of blocking ultraviolet rays, especially ultraviolet rays in the UV-A region.
By blending in cosmetics, films, plastics and paints, it is extremely effective in preventing deterioration and deterioration due to ultraviolet rays.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction diagram of the ultraviolet ray blocking agent produced in Example 1.

FIG. 2 is a curve diagram showing an ultraviolet ray absorbing effect of the ultraviolet ray blocking agent produced in Example 1.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Masui 1-220 C20-103 Aoyamadai, Suita-shi, Osaka F-term (reference) 4J002 AA001 AA011 DE096 DE097 DE107 DE117 DE137 DE147 DE186 FA057 FD056 GA01 GG00 GH01 GL00 GN00 GP00 GQ00

Claims (5)

[Claims] 1. An ultraviolet ray blocking agent comprising fine particles having a band gap in the range of 2.5 to 3.2 eV and an average particle diameter in the range of 1 to 500 nm. 2. The ultraviolet blocking agent according to claim 1, wherein said fine particles are made of an inorganic oxide. 3. The method according to claim 1, wherein the fine particles are cerium oxide, titanium oxide,
Zinc oxide, zirconium oxide, yttrium oxide, lanthanum oxide, gadolinium oxide, lutetium oxide, silicon oxide, magnesium oxide, tungsten oxide, tin oxide, iron oxide, aluminum oxide, nickel oxide, cobalt oxide, barium titanate, strontium titanate,
One or more oxides selected from calcium titanate, barium cerium, strontium cerate, calcium cerate, and aluminum lanthanoid oxide, and / or an oxide in which two or more of these are combined The ultraviolet blocking agent according to any one of claims 1 to 2, characterized in that: 4. The fine particles obtained by compounding cerium oxide with 0.005 to 30 mol% of one or more selected from titanium oxide, zinc oxide, iron oxide, aluminum oxide, nickel oxide and cobalt oxide. The ultraviolet ray blocking agent according to any one of claims 1 to 3, wherein 5. The method according to claim 1, wherein the fine particles are cerium oxide and titanium oxide,
Zinc oxide, iron oxide, aluminum oxide, nickel oxide,
The ultraviolet blocking agent according to claim 4, wherein the ultraviolet blocking agent is a solid solution of one or more oxides selected from cobalt oxide.