JP2005067984A - Oxide-cerium hydroxide composite body, and resin composition and cosmetic material blended with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxide-cerium hydroxide composite body having high ultraviolet light shielding capacity, reduced catalytic activity and high whiteness, and to provide a resin composition and a cosmetic material blended with the composite body. <P>SOLUTION: The oxide-cerium hydroxide composite body is obtained by coating an oxide-cerium hydroxide expressed by Ce<SP>4+</SP><SB>1-X</SB>Ce<SP>3+</SP><SB>X</SB>O<SB>2-X</SB>(OH)<SB>X</SB>(wherein, 0<X<1) with one or more kinds of oxides selected from silicon oxide, zirconium oxide, aluminum oxide, iron oxide and titanium oxide. Alternatively, an oxide-cerium hydroxide obtained by making a metallic ion having an ion radius larger than that of tetravalent cerium ion and /or a metallic ion having a valence lower than that of tetravalent cerium ion into a solid solution in the oxide-cerium hydroxide expressed by Ce<SP>4+</SP><SB>1-X</SB>Ce<SP>3+</SP><SB>X</SB>O<SB>2-X</SB>(OH)<SB>X</SB>(wherein, 0<X<1) is coated with one or more kinds of oxides selected from silicon oxide, zirconium oxide, aluminum oxide, iron oxide and titanium oxide, so that the oxide-cerium hydroxide composite body in which the one or more kinds of oxides enter into the solid solution is obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a composite obtained by coating cerium oxyhydroxide containing cerium partially reduced to trivalent or the above-mentioned cerium oxyhydroxide in which metal ions are dissolved (doped) with an inorganic oxide. Moreover, it is related with the resin composition or cosmetics which mix | blended these composites.

  Since ultraviolet rays degrade plastics, various measures have been taken to prevent this degradation. As one of them, various ultraviolet blocking agents called organic ultraviolet absorbers and inorganic ultraviolet scattering agents have been developed, and the effects of ultraviolet rays have been reduced by adding them to plastics. Organic UV absorbers include salicylic acid, benzophenone, benzotriazole, and cyanoacrylate, but recently there have been problems such as lack of heat resistance and weather resistance and the safety of their decomposition products. ing. For the purpose of solving these problems, inorganic ultraviolet scattering agents such as fine particle titanium oxide and fine particle zinc oxide have been developed. However, these also cause problems such as dispersibility and catalytic action. Particularly in recent years, it has been pointed out that generation of singlet oxygen due to photocatalytic action may cause problems with titanium oxide.

  In addition, ultraviolet rays are known to have an adverse effect on living organisms, and ultraviolet rays in the UV-B region having a wavelength of 280 to 320 nm cause inflammation such as erythema and water bubbles on the skin, and have a wavelength of 320 to 400 nm. Ultraviolet rays in the UV-A region are known to promote melanin production and cause skin browning. Conventionally, various sunscreen cosmetics are known as countermeasures against such adverse effects of ultraviolet rays. The UV blocking agents that have been used in these cosmetics can be broadly classified into UV absorbers such as cinnamic acid, benzophenone and dibenzoylmethane, and UV scattering agents such as zinc oxide and titanium oxide. There are two types. However, these ultraviolet absorbers have problems such as insufficient absorbability with respect to ultraviolet rays and are not preferable from the viewpoint of safety when incorporated in a large amount. Furthermore, since it has been difficult to improve the transparency of conventional ultraviolet scattering agents even if the dispersibility is improved, there are problems such as an unnatural cosmetic finish as well as a deterioration in the feeling of use. It was.

  In recent years, techniques using an insoluble cerium compound such as cerium oxide as an ultraviolet scattering agent have been proposed (Patent Documents 1 and 2). However, cerium oxide has a high catalytic activity, promotes oxidative degradation of resins and oils and fats, causes problems of discoloration and odor when blended in cosmetics and resins, and has poor transparency and whiteness. There is also a problem that the degree is inferior. In order to meet this demand, composite particles of silica and other metal oxides and cerium oxide have been proposed (Patent Document 3, Patent Document 4), but the metal oxide / cerium oxide composite particles are transparent, Although the whiteness was improved, the catalytic activity was not sufficiently reduced. Moreover, although cerium oxide with high whiteness has been proposed (Patent Document 5), it is difficult to obtain fine particles, and the effect as an ultraviolet blocking material is insufficient, and there is no effect of reducing catalytic activity.

Therefore, metal oxide solid solution cerium oxide has recently been proposed as a cerium compound having no catalytic activity and having a good ultraviolet scattering action (Patent Documents 6 and 7). In addition, these documents also describe metal oxide solid solution cerium oxide with high whiteness, and this metal oxide solid solution cerium oxide with high whiteness is controlled by controlling the reaction conditions during the formation reaction. It is disclosed that it can be obtained.
JP-A-6-145645 JP-A-7-207251 JP-A-9-118610 JP 2000-203835 A Japanese Patent Laid-Open No. 10-226518 JP 2000-327328 A JP 2002-160920 A

  The present invention has been made under the above circumstances, and has a high ultraviolet blocking ability, reduced catalytic activity, good transparency and high whiteness, cerium oxyhydroxide or metal oxide solid solution acid water An object is to provide a complex of cerium oxide. Furthermore, an object of this invention is to provide the resin composition and cosmetics which mix | blended the above-mentioned composite_body | complex.

That is, the present invention relates to cerium ^oxyhydroxide represented by Ce ⁴⁺ _1-X Ce ³⁺ _X O _2−X (OH) _X (where 0 <X <1), silicon oxide, zirconium oxide, aluminum oxide, It is a cerium oxyhydroxide complex formed by coating with one or more oxides selected from iron oxide and titanium oxide. In the present invention, the cerium ^oxyhydroxide represented by Ce ⁴⁺ _1-X Ce ³⁺ _X O _2−X (OH) _X (where 0 <X <1) is larger than a tetravalent cerium ion. A kind of cerium oxyhydroxide in which a metal ion having a radius and / or a metal ion having a lower valence than tetravalent cerium ion is dissolved, is selected from silicon oxide, zirconium oxide, aluminum oxide, iron oxide, and titanium oxide Or it is a metal oxide solid solution cerium oxyhydroxide complex formed by coating with two or more kinds of oxides.

As the metal ions to be ^solidified , one or two selected from Ca ²⁺ , Y ³⁺ , La ³⁺ , Nd ³⁺ , Eu ³⁺ , Tb ³⁺ , Sm ³⁺ , Mg ²⁺ , Sr ²⁺ , Ba ²⁺ and Zn ^2+. More than species are preferred. The above composite has an L ^* value of 80 or more, an a ^* value of 4 or less in absolute value, and a b ^* value of 10 or less in absolute value when evaluated by the L ^* a ^* b ^* system. Is preferred. Furthermore, this invention is a resin composition or cosmetics which mix | blend said composite_body | complex.

  Oxide-coated cerium oxyhydroxide composite or oxide-coated metal oxide solid solution cerium oxyhydroxide complex of the present invention [these are referred to as oxide-coated (metal oxide solid solution) cerium oxyhydroxide complex Has an excellent ultraviolet blocking property, is both white and transparent, and has reduced catalytic activity of cerium oxide. Therefore, it can mix | blend with a resin composition and cosmetics, and can provide the outstanding ultraviolet-blocking effect, without changing those color tone.

Conventionally, in general, cerium oxide (CeO ₂ ) is produced by reacting a cerium salt aqueous solution with an alkali to produce cerium hydroxide and then oxidizing with an oxidant, or cerium salt aqueous solution, an alkali aqueous solution and an oxidant. Are made to react at the same time. For example, a cerium salt solution and an alkali solution having a predetermined concentration are prepared in advance, and the alkali solution is first put in a reaction vessel so that the alkali solution is present. Then, the resulting reaction solution is oxidized by adding an oxidizing agent, washed with water, filtered and dried to obtain cerium oxide. The cerium oxide thus obtained is yellowish and has a high catalytic activity.

  The aqueous cerium salt solution used in the above reaction is prepared by, for example, dissolving cerium carbonate with an aqueous acid solution such as hydrochloric acid or nitric acid, or dissolving cerium chloride, cerium nitrate, cerium sulfate, cerium acetate, or the like in water. As the alkali, an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or aqueous ammonia can be used. The metal salt to be dissolved is, for example, chloride, nitrate, sulfate, acetate or the like. As the oxidizing agent, hydrogen peroxide, hypochlorous acid, sodium hypochlorite, potassium hypochlorite, calcium hypochlorite, ozone or the like can be used.

  By the way, the present invention has been made by finding the following matters. That is, in the above-described conventional production of cerium oxide, in the reaction of oxidizing trivalent cerium to tetravalent cerium by an oxidizing agent, this oxidation reaction is performed in a neutral to acidic region, and the oxidizing agent is used in the chemistry of the oxidation reaction. If no stoichiometric amount is added or if reductive organic substances such as methanol coexist, and oxidation does not occur completely, cerium oxide with high whiteness and reduced catalytic activity can be obtained. It is an invention that was discovered and made.

Then, when the cerium oxide complex produced through the reaction process that was generated without completely performing the oxidation reaction as described above was subjected to oxidation-reduction titration analysis, trivalent in addition to tetravalent cerium in this cerium oxide. The presence of cerium was confirmed. Further, when thermogravimetric analysis of white cerium oxide was performed, a weight reduction was observed between 200 ° C. and 700 ° C., and this phenomenon of weight reduction was attributed to the elimination of structural water (OH in the crystal was converted to H ₂ O). Cerium oxide produced through the reaction process that is generated without completely performing the oxidation reaction as described above is Ce ⁴⁺ _1-X Ce ³⁺ _X O _2−X (OH) _X (however, , Cerium oxyhydroxide in a form represented by a chemical structure of 0 <X <1). This cerium oxyhydroxide has high whiteness and has an excellent ultraviolet blocking effect as in the case of conventional cerium oxide.

However, cerium ^{oxyhydroxide in the} form represented by the chemical structure of Ce ⁴⁺ _1-X Ce ³⁺ _X O _2−X (OH) _X (where 0 <X <1) has whiteness when exposed to air. It will drop and become yellowish. However, this cerium oxyhydroxide is a kind selected from silicon oxide, zirconium oxide, aluminum oxide, iron oxide, and titanium oxide in a state before the whiteness is lowered (what is in this state is called an intermediate). Alternatively, when the composite is coated with two or more kinds of oxides (oxide-coated cerium oxyhydroxide composite), the whiteness can be maintained even when exposed to air, and the catalytic activity can also be reduced.

This composite is produced by forming cerium oxyhydroxide as an intermediate and coating it with one or more oxides selected from silicon oxide, zirconium oxide, aluminum oxide, iron oxide, and titanium oxide. . That is, when cerium oxide is produced by reacting an aqueous cerium salt solution with an alkali to produce cerium hydroxide and then oxidizing with an oxidizing agent, or by reacting an aqueous cerium salt aqueous solution with an aqueous alkaline solution and an oxidizing agent simultaneously, By carrying out this oxidation reaction in a neutral to acidic region and under conditions where oxidation is not complete, cerium oxyhydroxide, an intermediate having the above chemical structure, is produced. Next, while maintaining the pH of the intermediate at 9 or more, for example, a sodium silicate aqueous solution and a mineral acid such as hydrochloric acid, nitric acid, and sulfuric acid are dropped to obtain a composite in which cerium oxyhydroxide is coated with silicon oxide, and then washed with water. Filter, dry and pulverize to produce a powdered silicon oxide-coated cerium oxyhydroxide composite. In this case, the amount of sodium silicate to be dropped is 2-60% of the conjugates as SiO ₂ are suitable. This oxide coating can maintain high whiteness and reduced catalytic activity even when cerium oxyhydroxide is exposed to air.

  The method for producing the above intermediate cerium oxyhydroxide will be described more specifically. That is, an alkaline aqueous solution is placed in a container, and a cerium salt aqueous solution is dropped and reacted under conditions of a temperature of 60 ° C. or lower, pH 5 or higher, preferably pH 8 or higher to produce cerium hydroxide, and then a temperature of 60 ° C. or lower and pH 7 An oxidant is added under the following conditions and washed with water to produce an intermediate. Alternatively, water is put into a container, and a cerium salt aqueous solution and an alkaline aqueous solution are added dropwise under conditions of a temperature of 60 ° C. or lower, pH 5 or higher, preferably pH 8 or higher to form cerium hydroxide, and then a temperature of 60 ° C. or lower and pH 7 or lower. The intermediate is produced by adding an oxidizing agent under the conditions of, and washing with water. Alternatively, there is a method in which an intermediate is produced by putting water in a container, dropping a cerium salt aqueous solution, an alkaline aqueous solution and an oxidizing agent under conditions of a temperature of 60 ° C. or lower and a pH of 5 or higher, and washing with water. In this case, the amount of the oxidizing agent to be dropped is suitably 40 to 97% of the stoichiometric amount, and preferably 60 to 85%. In the above reaction, a reducing organic substance can be present together. In that case, the amount of the reducing organic substance is suitably 1 to 60% by mass with respect to the alkaline aqueous solution or water placed in the container before the dropping. In the case of adopting any of the above-described reactions, the average particle size can be reduced by dropping the oxidant while setting the temperature of the liquid to 60 ° C. or less, preferably 40 ° C. or less and the pH after the reaction to 7 or less. An intermediate of 2 to 4 nm ultrafine particles can be obtained.

Further, the cerium ^{oxyhydroxide having} a chemical structure of Ce ⁴⁺ _1-X Ce ³⁺ _X O _2−X (OH) _X (where 0 <X <1) has a larger ionic radius than the tetravalent cerium ion. Metal ions having a lower valence than metal ions and / or tetravalent cerium ions may be dissolved. The metal ions to be dissolved are Ca ²⁺ , Y ³⁺ , La ³⁺ , Nd ³⁺ , Eu ³⁺ , Tb ³⁺ , Sm ³⁺ , Mg ²⁺ , Sr ²⁺ , Ba ²⁺ and Zn ^2+. The above is preferable. The concentration of cerium oxyhydroxide in the solid solution is preferably 40 to 98 mol%. An intermediate in which these metal ions are dissolved, that is, a metal oxide solid solution cerium oxyhydroxide (hereinafter sometimes referred to as a solid solution intermediate) is Ce ⁴⁺ _1-XY Ce ³⁺ _X M ^{n +} _{Y 2} O _{2. —X—Y (4-n) / 2} (OH) _X where 0 <X ≦ 0.5, 0 <Y <1, n is a valence, and M is a metal atom. Can do. The solid solution intermediate is coated with one or more oxides selected from silicon oxide, zirconium oxide, aluminum oxide, iron oxide, and titanium oxide to form a composite (hereinafter, this composite is a solid solution composite). Manufacturing). By making the metal oxide solid solution cerium oxyhydroxide, the catalytic activity can be further reduced while maintaining the ultraviolet blocking action.

The above solid solution intermediate metal oxide solid solution cerium oxyhydroxide includes a cerium salt aqueous solution, a metal ion having an ionic radius larger than a tetravalent cerium ion and / or a metal having a lower valence than a tetravalent cerium ion. It can be produced by reacting an aqueous metal salt solution of an ion with an alkali to form a solid solution of cerium hydroxide and a metal hydroxide, and then oxidizing by adding an oxidizing agent. The metal ion solution having a larger ionic radius than the cerium ion and / or the metal salt aqueous solution of the metal ion having a lower valence than the tetravalent cerium ion, an alkali, and an oxidizing agent can be produced simultaneously by dropwise mixing. As described above, the metal oxide solid solution cerium hydroxide having a high whiteness can be obtained by preventing the oxidation in the neutral to acidic region and completely oxidizing. It is. The metal oxide solid solution cerium hydroxide obtained at this time is Ce ⁴⁺ _1-X Ce ³⁺ _X O _2−X (OH) _X (where 0 <X <1), A metal ion having a larger ion radius than the tetravalent cerium ion and / or a metal ion (metal oxide) having a lower valence than the tetravalent cerium ion is in a solid solution state.

  The production method of the metal oxide solid solution cerium oxyhydroxide, which is a solid solution intermediate, will be described more specifically. A metal of an aqueous cerium salt solution and a metal ion having a larger ionic radius than a tetravalent cerium ion and / or a metal ion having a lower valence than a tetravalent cerium ion under conditions of a temperature of 60 ° C. or less, pH 5 or more, preferably pH 8 or more After an aqueous salt solution and an alkali are reacted to form a solid solution of cerium hydroxide and a metal hydroxide, an oxidant is added under conditions of a temperature of 60 ° C. or lower and a pH of 7 or lower to generate a solid solution intermediate. In this case, the amount of the oxidizing agent to be dropped is suitably 40 to 97% of the stoichiometric amount, and preferably 60 to 85%. In the above reaction, a reducing organic substance can be present together. In that case, the amount of the reducing organic substance is suitably 1 to 60% by mass with respect to the alkaline aqueous solution or water placed in the container before the dropping. As an aspect of generating a solid solution of the above cerium hydroxide and metal hydroxide, (1) a method in which an alkaline aqueous solution is placed in a container and a cerium salt aqueous solution and a metal salt aqueous solution to be dissolved in the solution are simultaneously added dropwise; (2) There is a method in which water is put into a container, and a cerium salt aqueous solution and an aqueous solution of a metal salt to be dissolved in an alkaline aqueous solution are dropped simultaneously.

  Further, an aqueous cerium salt solution and / or metal ions having a larger ion radius than tetravalent cerium ions and / or metal ions having a lower valence than tetravalent cerium ions under conditions of a temperature of 60 ° C. or lower, pH 5 or higher, preferably pH 8 or higher. An aqueous solution of a metal salt, an alkali, and an oxidizing agent are simultaneously started to be dropped and mixed, and the pH is adjusted to 7 or less at the end of the reaction. For example, a cerium salt aqueous solution, an aqueous solution of a metal salt to be dissolved, an alkaline aqueous solution, and hydrogen peroxide as an oxidizing agent are simultaneously dropped into water in a container under conditions of a temperature of 60 ° C. or lower and a pH of 5 or higher. Thus, a solid solution intermediate is produced. In this case, the amount of the oxidizing agent to be dropped is suitably 40 to 97% of the stoichiometric amount, and preferably 60 to 85%. In the above reaction, a reducing organic substance can be present together. In that case, the amount of the reducing organic substance is suitably 1 to 60% by mass with respect to the alkaline aqueous solution or water placed in the container before the dropping. In the case of adopting any of the above-described reactions, the average particle size is reduced by setting the temperature of the liquid to 60 ° C. or lower, preferably 40 ° C. or lower, and the pH at the end of the reaction to 7 or lower during dropping of the oxidizing agent. A solid solution intermediate of ultrafine particles of 2 to 4 nm can be obtained.

  When exposed to air, the solid solution intermediate metal oxide solute cerium hydroxide obtained as described above gradually decreases in whiteness and becomes yellowish. However, prior to exposure to air, if a solid solution composite coated with one or more oxides selected from silicon oxide, zirconium oxide, aluminum oxide, iron oxide, and titanium oxide is used, this composite is exposed to air. However, the whiteness can be maintained. This oxide-coated metal oxide solid solution cerium oxyhydroxide complex can be produced in the same manner as described above for the oxide-coated cerium oxyhydroxide complex. That is, a solid solution intermediate metal oxide solid solution cerium oxyhydroxide is produced by the above-mentioned method, and then, while maintaining the pH at 9 or more, for example, sodium silicate aqueous solution and mineral acid such as hydrochloric acid, nitric acid, sulfuric acid and the like Is added dropwise, and the metal oxide solid solution cerium oxyhydroxide is coated with silicon oxide, and then washed with water, filtered, and dried and pulverized to produce a powdered silicon oxide-coated metal oxide solid solution cerium oxyhydroxide complex. .

The above oxide-coated (metal oxide solid solution) cerium oxyhydroxide composite has good whiteness, and when evaluated by the L ^* a ^* b ^* system, the L ^* value is 80 or more, and the a ^* value In which the absolute value is 4 or less and the b ^* value is 10 or less in absolute value. In addition, the oxide-coated (metal oxide solid solution) cerium oxyhydroxide composite was excellent in transparency in the visible light region, excellent in dispersibility, and further had a high ultraviolet blocking effect and low catalytic activity. .

The above ^L * ^a * ^{b *} is defined by the CIE1976L ^* a ^* b ^* color space defined by the CIE (International Commission on Illumination) in 1976. This color space is a color space having quantities L ^* , a ^* , and b ^* defined by the following equations in an orthogonal coordinate system.
L * = 116 (Y / Y ₀ ) ^1/3 −16
a * = 500 [(X / X ₀ ) ¹ /3-(Y / Y ₀ ) ^1/3 ]
b * = 200 [(Y / Y ₀ ) ¹ / ^3- (Z / Z ₀ ) ^1/3 ]
(However, X / X ₀ , Y / Y ₀ , Z / Z ₀ > 0.008856, X, Y, Z are tristimulus values of the object color, and X ₀ , Y ₀ , Z ₀ are light sources that illuminate the object color. And are normalized to Y ₀ = 100). The measurement is performed using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd.).

  In addition, when the oxide-coated (metal oxide solid solution) cerium oxyhydroxide complex is blended in a composition such as a resin composition or a cosmetic, these may be further surface-treated. Examples of the surface treatment agent include general oil agent, metal soap treatment, silicone treatment, alkyl phosphate treatment, compound treatment having a perfluoroalkyl group, amino acid treatment, lecithin treatment, collagen treatment and the like.

  Next, the resin composition and cosmetics according to the present invention will be described. In general, a resin composition deteriorates by absorbing light in the ultraviolet region of sunlight. As a countermeasure against ultraviolet rays, light resistance is improved by adding the oxide-coated (metal oxide solid solution) cerium oxyhydroxide composite of the present invention to the resin composition, and light deterioration can be prevented or reduced. Further, it is possible to prevent or reduce the light deterioration of the contents covered with the transparent resin composition due to ultraviolet rays. Further, since the composite of the present invention has a very small catalytic activity as compared with cerium oxide, the oxidative deterioration of the resin composition based on cerium oxide can be remarkably reduced. The resin composition as used herein refers to all resin compositions such as synthetic resins such as polyvinyl chloride, polypropylene, polyethylene, polyamide, polyester, and polycarbonate, molded products of natural resins, and paints blended with these resins.

  Next, the cosmetic according to the present invention will be described. The cosmetic of the present invention has an excellent ultraviolet blocking effect by blending the above-mentioned oxide-coated (metal oxide solid solution) cerium oxyhydroxide complex of the present invention, and has excellent transparency. Further, since the composite of the present invention has a very small catalytic activity compared to cerium oxide, cosmetics formulated with this composite are more suitable for oils and fats in cosmetics than conventional cosmetics formulated with cerium oxide. There is an advantage that it is possible to reduce troubles such as deterioration of the blended ingredients and generation of a bad odor based on it, that is, to improve the product stability of the cosmetic. As a cosmetic dosage form, it can be used for skin care cosmetics such as emulsions and lotions, makeup cosmetics such as foundations and lipsticks, hair cosmetics and the like, and sunscreen cosmetics are particularly preferred. The blending amount is not particularly limited, but is preferably 0.1 to 70% by mass.

  In the cosmetic according to the present invention, the effect becomes remarkable when combined with an ultraviolet absorber and / or an ultraviolet scattering agent which is an ultraviolet protective agent. As the ultraviolet absorber, one or more selected from oxybenzone, octyl methoxycinnamate, and 4-tert-butyl-4'-methoxydibenzoylmethane are preferable. Although the compounding quantity of a ultraviolet absorber is not specifically limited, Preferably it is 0.1-40 mass%. As the ultraviolet scattering agent, titanium oxide and / or zinc oxide is preferable, and fine particle titanium oxide and / or zinc oxide having an average particle diameter of 0.05 μm or less is more preferable. As a compounding quantity of a ultraviolet-ray scattering agent, 0.1-50 mass% is preferable.

Furthermore, the cosmetics of the present invention include components usually used in cosmetics, such as powders, surfactants, oils, gelling agents, polymers, cosmetic ingredients, moisturizers, pigments, preservatives, and fragrances. It can be used as long as the effects of the invention are not impaired.
Example 1

493 g of cerium chloride (CeCl ₃ ) is dissolved in water to prepare 3.3 L of cerium chloride solution. Further, 3.3 L of sodium hydroxide solution is prepared by dissolving 237 g of sodium hydroxide in water. Further, 68 g of 30% hydrogen peroxide solution is dissolved in water to prepare 3.3 L of hydrogen peroxide solution. While stirring, a cerium chloride solution and a sodium hydroxide solution are simultaneously added dropwise to 8.5 L of water heated to 30 to 40 ° C. so that the pH of the reaction solution is 9 to 11 and the temperature is kept at 40 ° C. or less. An oxide slurry is obtained. To this, 1 mol / L hydrochloric acid is added to pH 7 or less, and a hydrogen peroxide solution is added dropwise. At the end of dropping, the pH of the reaction solution is adjusted to 5-7. After stirring for 30 minutes after completion of the reaction, the produced cerium oxyhydroxide is decanted and washed 5 times with water to prepare cerium oxyhydroxide. 562 g of a sodium silicate solution (SiO ₂ content 28.5 mass%) is dissolved in water to prepare 2 L of a sodium silicate solution. 25.8 L of dilute sulfuric acid solution is prepared by diluting 75.8 g of 95% by mass sulfuric acid in water. While heating and stirring cerium oxyhydroxide at 80 ° C. or higher, a sodium silicate solution and a dilute sulfuric acid solution are simultaneously added dropwise so that the pH of the reaction solution can be maintained at 9 or higher. After completion of the dropwise addition of both solutions, the mixture is stirred for 30 minutes and adjusted with dilute sulfuric acid so that the pH of the reaction solution becomes 7-8. This was filtered, washed with water, dried and pulverized to obtain a silicon oxide-coated cerium oxyhydroxide composite powder containing 30% by mass of SiO ₂ . The whiteness of the obtained powder was L ^* value 94.0, a ^* value -1.4, and b ^* value 5.2. The L ^* value, a ^* value, and b ^* value were measured with a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd.) by pressing 20 g of a sample on a 6 cm diameter metal pan. The obtained composite was excellent in transparency in the visible light region, excellent in dispersibility, high in ultraviolet blocking effect, and low in catalytic activity.
Example 2

493 g of cerium chloride (CeCl ₃ ) is dissolved in water to prepare 3.3 L of cerium chloride solution. Further, 3.3 L of sodium hydroxide solution is prepared by dissolving 237 g of sodium hydroxide in water. Further, 68 g of 30% hydrogen peroxide solution is dissolved in water to prepare 3.3 L of hydrogen peroxide solution. To 7 L of water heated to 30 to 40 ° C. and 2 L of methanol, a cerium chloride solution and a sodium hydroxide solution are simultaneously added dropwise with stirring so that the reaction solution has a pH of 9 to 11 and a temperature of 40 ° C. or lower. A hydroxide slurry is obtained. A hydrogen peroxide solution is added dropwise thereto. At the end of dropping, 1 mol / L hydrochloric acid is added and adjusted so that the pH of the reaction solution becomes 5-7. After stirring for 30 minutes after completion of the reaction, the produced cerium oxyhydroxide is decanted and washed 5 times with water to prepare cerium oxyhydroxide. 300 g of sodium silicate solution (SiO ₂ content 28.5 mass%) is dissolved in water to prepare 2 L of sodium silicate solution. 20.5 L of dilute sulfuric acid solution is prepared by diluting 50.5 g of 95% by mass sulfuric acid in water. While heating and stirring cerium oxyhydroxide at 80 ° C. or higher, a sodium silicate solution and a dilute sulfuric acid solution are simultaneously added dropwise so that the pH of the reaction solution can be maintained at 9 or higher. After completion of the dropwise addition of both solutions, the mixture is stirred for 30 minutes and adjusted with dilute sulfuric acid so that the pH of the reaction solution becomes 7-8. This was filtered, washed with water, dried, and pulverized to obtain a silicon oxide-coated cerium oxyhydroxide complex containing 20% by mass of SiO ₂ . The average primary particle size of this composite was 5 nm. The particle diameter was measured using a transmission electron microscope (manufactured by JEOL). That is, the particle diameter was visually measured for 100 primary particles, and the average value was obtained. The obtained fine particle silicon oxide-coated cerium oxyhydroxide composite fine particles were excellent in transparency in the visible light region, excellent in dispersibility, high in ultraviolet blocking effect, and low in catalytic activity.
Example 3

394 g of cerium chloride (CeCl ₃ ) and 245 g of calcium chloride (CaCl ₂ ) were dissolved in water to prepare 3 L of a mixed aqueous solution of cerium chloride and calcium chloride. Further, 224 g of sodium hydroxide was dissolved in water to prepare 3 L of an aqueous sodium hydroxide solution. Furthermore, 3 g of a hydrogen peroxide solution was prepared by dissolving 55 g of 30% hydrogen peroxide water in water. The above cerium calcium chloride mixed aqueous solution, sodium hydroxide aqueous solution and hydrogen peroxide aqueous solution were simultaneously added dropwise to 8 L of water at a pH of 11 or more and a temperature of 40 ° C. while stirring. At the end of dropping, 1 mol / L hydrochloric acid is added and adjusted so that the pH of the reaction solution becomes 5-7. After stirring for 30 minutes, the produced calcium oxide solid solution cerium oxyhydroxide is decanted and washed with water five times to prepare calcium oxide solid solution cerium hydroxide having a ratio of calcium to cerium of 2: 8. . 447 g of a sodium silicate solution (SiO ₂ content 28.5 mass%) is dissolved in water to prepare 2 L of a sodium silicate solution. 25.5 L of dilute sulfuric acid solution is prepared by diluting 75.5 g of 95 mass% sulfuric acid in water. While heating and stirring cerium oxyhydroxide at 80 ° C. or higher, a sodium silicate solution and a dilute sulfuric acid solution are simultaneously added dropwise so that the pH of the reaction solution can be maintained at 9 or higher. After completion of the dropwise addition of both solutions, the mixture is stirred for 30 minutes and adjusted with dilute sulfuric acid so that the pH of the reaction solution becomes 7-8. This was filtered, washed with water, dried and pulverized to obtain a silicon oxide-coated calcium oxide solid solution cerium oxyhydroxide complex containing 30% by mass of SiO ₂ . The average particle size of this composite was 5 nm. The particle diameter was measured using a transmission electron microscope (manufactured by JEOL). That is, the particle diameter was visually measured for 100 particles, and the average value was obtained. The obtained fine particle silicon oxide-coated calcium oxide solid solution cerium oxyhydroxide composite had excellent transparency in the visible light region, excellent dispersibility, high ultraviolet blocking effect, and low catalytic activity.
Comparative Examples 1-3

In Examples 1 to 3, conditions other than adding an equivalent amount (0.5 mol) of hydrogen peroxide required to oxidize 1 mol of cerium (III) chloride to cerium (IV) oxide were the same as in Examples 1 to 3. The silicon oxide-coated cerium oxyhydroxide complex and the silicon oxide-coated calcium oxide solid solution cerium oxyhydroxide complex were produced under the same conditions as in Comparative Examples 1 to 3, respectively.
About the composite_body | complex obtained in Examples 2-3 and Comparative Examples 1-3, it carried out similarly to Example 1, and measured whiteness. The results are shown in Table 1 together with the results of Example 1.

Compared to the composites obtained in Examples 2 to 3, the composites obtained in Comparative Examples 1 to 3 were inferior in whiteness and yellowish.
Example 4

The silicon oxide-coated cerium oxyhydroxide composite obtained in Example 1 was blended with 0, 0.5, 1, and 2.0% by mass of soft polyvinyl chloride, and these were each molded into a sheet using a heating roll. . When the light transmittance of these sheets was measured with a spectrophotometer (UV-2200, manufactured by Shimadzu Corporation), the above-mentioned silicon oxide-coated oxyhydroxide was compared with the one without the above silica-coated cerium oxyhydroxide composite powder. It was found that the addition of the cerium composite increases the blocking effect in the ultraviolet region as the blending ratio increases, but maintains high transparency in the visible region.
Example 5

Using the oxide-coated (metal oxide solid solution) cerium hydroxide hydroxide composite obtained in Examples 1 to 3, a cream foundation was produced by the following composition and preparation method.
Ingredient Mass%
(1) Stearic acid 5.0
(2) Lipophilic glyceryl monostearate 2.5
(3) Cetanol 1.5
(4) Isopropylene glycol monolaurate 2.5
(5) Flowing paraffin 8.0
(6) Isopropyl myristate 7.0
(7) Propyl paraoxybenzoate 0.1
(8) Purified water remaining amount (9) Triethanolamine 1.2
(10) Sorbitol 3.0
(11) Methyl paraoxybenzoate 0.2
(12) Titanium oxide 8.0
(13) Kaolin 5.0
(14) Oxide-coated (metal oxide solid solution) cerium oxyhydroxide composite 3.0
(15) Bentonite 1.0
(16) Bengala 2.5
(17) Yellow iron oxide 2.0
(18) Black iron oxide 0.2

Preparation method:
A. (12)-(14) and (16)-(18) are mixed well.
B. Add (15) to (8) at 80 ° C. and swell well. Next, (9) to (11) are added and dissolved. The mixture of a is added to this and melt | dissolved at 80 degreeC (water phase).
C. (1) to (7) are dissolved at 80 ° C. (oil phase).
D. Add (oil phase) to (water phase) and emulsify. Thereafter, the mixture is cooled and stirred and cooled to 35 ° C.
The cream foundation obtained as described above had a sense of transparency, good elongation, an excellent ultraviolet blocking effect, and good stability due to reduced catalytic activity.
Example 6

Using the oxide-coated (metal oxide solid solution) cerium hydroxide complex obtained in Examples 1 to 3, sunscreen emulsions were produced by the following composition and preparation method.
Ingredient Mass%
(1) Oxide coating (metal oxide solid solution) Cerium oxyhydroxide complex 10.0
(2) Acrylic silicone copolymer solution * 1 1.0
(3) Glyceryl triisooctanoate 5.0
(4) Squalane 5.0
(5) Methyl polysiloxane (10CS) 10.0
(6) Decamethylcyclopentasiloxane 20.0
(7) Sorbitan sesquioleate 4.0
(8) Polyoxyethylene / methylpolysiloxane copolymer * 2 2.0
(9) Oxybenzone 0.1
(10) 1,3-butylene glycol 9.0
(11) Preservative appropriate amount (12) Purified water remaining amount (13) Fragrance proper amount * 1: KP-545 (manufactured by Shin-Etsu Chemical Co., Ltd.)
* 2: KF-6017 (manufactured by Shin-Etsu Chemical Co., Ltd.)

Preparation method:
A. (2) to (9) were dissolved, and (1) was added thereto and kneaded well.
B. (10) to (12) were dissolved and added to a and emulsified and mixed.
C. (13) was added to and mixed with B to obtain a sunscreen emulsion.
The sunscreen emulsion obtained as described above was transparent, had good makeup, had an excellent ultraviolet blocking effect, and had a good stability due to reduced catalytic activity.

Comparative Example 4
When the cream foundation was prepared according to the prescription of Example 5 using the composites obtained in Comparative Examples 1 to 3, the transparency was inferior, and an unnatural yellowish finish was obtained.
Comparative Example 5
Using the composites obtained in Comparative Examples 1 to 3, the sunscreen emulsion was prepared according to the formulation of Example 6, and the ultraviolet blocking effect was excellent, but the color of the emulsion was yellow, and the natural finish was It was not obtained.

Claims (6)

Ce ⁴⁺ _1-X Ce ³⁺ _X O _2−X (OH) _X (where 0 <X <1) is converted from cerium oxyhydroxide from silicon oxide, zirconium oxide, aluminum oxide, iron oxide, and titanium oxide. A cerium oxyhydroxide complex formed by coating with one or more selected oxides. Ce ⁴⁺ _1-X Ce ³⁺ _X O _2−X (OH) _X (where 0 <X <1) is a metal ion having an ionic radius larger than that of a tetravalent cerium ion and / or 2. The cerium oxyhydroxide complex according to claim 1, wherein metal ions having a lower valence than tetravalent cerium ions are dissolved. One or two kinds of metal ions ^solidified are selected from Ca ²⁺ , Y ³⁺ , La ³⁺ , Nd ³⁺ , Eu ³⁺ , Tb ³⁺ , Sm ³⁺ , Mg ²⁺ , Sr ²⁺ , Ba ²⁺ and Zn ^2+. It is the above, The cerium oxyhydroxide complex of Claim 2 characterized by the above-mentioned. The L ^* value is 80 or more, the a ^* value is 4 or less in absolute value, and the b ^* value is 10 or less in absolute value when the whiteness is evaluated in the L ^* a ^* b ^* system. The cerium oxyhydroxide complex according to any one of to 3. The resin composition formed by mix | blending the cerium oxyhydroxide complex in any one of Claims 1-4. Cosmetics which mix | blend the cerium oxyhydroxide complex in any one of Claims 1-4.