HK1181740A1

HK1181740A1 - Sheet-shaped cerium oxide and petal-shaped cerium oxide powder which is aggregate of the sheet-shaped cerium oxide, process for production of the sheet-shaped cerium oxide and the petal-shaped cerium oxide powder, coated sheet-shaped cerium oxide and petal-shaped cerium oxide powder which is aggregate of the coated sheet-shaped cerium oxide, and cosmetic

Info

Publication number: HK1181740A1
Application number: HK13109094.1A
Authority: HK
Inventors: 佐藤次雄; 殷澍; 田中巧; 西本健治; 粂井貴行; 粂井贵行; 渡部敬二郎
Original assignee: 大东化成工业株式会社; 株式会社芳凯尔
Priority date: 2010-08-12
Filing date: 2011-08-08
Publication date: 2013-11-15
Also published as: KR101939604B1; CN103180248A; KR20130139830A; WO2012020729A1; CN103180248B; JP5843431B2; JP2012041202A; TWI504568B; TW201210947A

Abstract

[Problem] To provide: sheet-shaped cerium oxide having an average particle diameter of less than 20 µm; a petal-shaped cerium oxide powder which is an aggregate of the sheet-shaped cerium oxide; a process for producing the sheet-shaped cerium oxide and the petal-shaped cerium oxide powder; and a cosmetic which is produced by adding the sheet-shaped cerium oxide or the petal-shaped cerium oxide powder which is an aggregate of the sheet-shaped cerium oxide to a cosmetic to thereby impart a high ultraviolet ray blocking effect and an excellent feeling upon application to the cosmetic. [Solution] Sheet-shaped cerium oxide having an average particle diameter of less than 20 µm and an average aspect ratio of 2-80 and a petal-shaped cerium oxide powder which is an aggregate of the sheet-shaped cerium oxide can be produced by preparing an aqueous solution comprising cerium nitrate or cerium chloride, sodium hydrogen carbonate or sodium carbonate and water so that the molar ratio of carbonate ions to cerium ions falls within the range of 1.5-5, maintaining the aqueous solution at a temperature falling within the range of 0-40°C to cause the precipitation of cerium carbonate particles from the aqueous solution, and then burning the cerium carbonate particles.

Description

Plate-like cerium oxide and petal-like cerium oxide powder as aggregate thereof, process for producing the same, coated plate-like cerium oxide and petal-like cerium oxide powder as aggregate thereof, and cosmetic

Technical Field

The present invention relates to a plate-like cerium oxide and a petal-like cerium oxide powder as an aggregate thereof, and a method for producing the same, a plate-like cerium oxide after coating treatment and a petal-like cerium oxide powder as an aggregate thereof, and a cosmetic containing the plate-like cerium oxide and the petal-like cerium oxide powder as an aggregate thereof or the plate-like cerium oxide after coating treatment and the petal-like cerium oxide powder as an aggregate thereof. Background

Conventionally, organic ultraviolet screening agents such as salicylic acid compounds and benzophenone compounds, and inorganic ultraviolet screening agents such as metal oxide fine particles of titanium oxide, zinc oxide, and the like have been used as ultraviolet screening agents used for sunscreen cosmetics and the like. Among them, organic ultraviolet screening agents are widely used because they are colorless and transparent when blended in cosmetics, but they are low molecular weight and therefore may be absorbed into the skin.

On the other hand, titanium oxide, which is generally used as an inorganic ultraviolet screening agent, is chemically stable, but has a problem that its use in products requiring transparency is limited because of its large hiding power (high refractive index). Further, zinc oxide has characteristics of high ultraviolet shielding ability in the UVA region and high transparency in the visible light region, but it has a property of being dissolved in a small amount in water or the like, and zinc ions eluted by sweat or the like are likely to permeate into the skin, and this is a concern in the case where safety to skin tissues is further required in the future.

For this reason, inorganic ultraviolet-screening agents using cerium compounds having relatively high transparency have been studied. For example, patent document 1 proposes an ultraviolet shielding agent in which cerium oxide particles or cerium-containing composite oxide particles having an average primary particle diameter of 1nm to 500nm, or the surface of these composites is coated with an amorphous or crystalline inorganic compound. However, the composite cerium oxide particles described in patent document 1 have a problem that they are aggregated due to fine particles, although they have an ultraviolet shielding ability, and thus they are not good in feeling of use.

On the other hand, as an inorganic ultraviolet shielding agent having a good feeling of use, compounding of plate-like particles with cerium oxide powder has been studied, and for example, patent document 2 proposes an ultraviolet absorbing composition comprising plate-like barium sulfate having a surface coated with a metal oxide such as cerium oxide. However, in the cerium oxide-coated barium sulfate plate-like particles described in patent document 2, ultraviolet shielding of the barium sulfate plate-like particles is insufficient, and there is a problem that ultraviolet shielding ability that can be satisfied as composite plate-like particles cannot be obtained.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2001 + 139926

Patent document 2: japanese laid-open patent publication No. 10-8028

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide plate-like cerium oxide having an average particle diameter of less than 20 μm, petal-like cerium oxide powder as an aggregate thereof, and a method for producing the powder. It is another object of the present invention to provide a cosmetic composition having a high ultraviolet shielding effect and an excellent feeling of use by blending the plate-like cerium oxide and the petal-like cerium oxide powder as an aggregate thereof.

Means for solving the problems

As a result of intensive studies to achieve the above object, the present inventors have found that a plate-like cerium oxide having an average primary particle size of less than 20 μm or a petal-like cerium oxide powder having a petal-like morphology as an aggregate can be obtained by firing plate-like cerium carbonate or petal-like cerium carbonate octahydrate as an aggregate precipitated from an aqueous solution prepared in an aqueous solution of cerium nitrate or cerium chloride, sodium bicarbonate or sodium carbonate, and water so that the molar ratio of cerium ions to carbonate ions is in the range of 1: 1.5 to 1: 5. Further, the present inventors have found that a hydrophobic powder can be obtained by coating the surface of the obtained plate-like cerium oxide or petal-like cerium oxide powder as an aggregate thereof with a compound such as polysiloxane, alkylsilane compound, alkyltitanate compound, fluorine compound, or the like, and that a cosmetic having a high ultraviolet shielding effect and an excellent feeling in use can be provided by blending these components in the cosmetic, thereby completing the present invention.

That is, the plate-shaped cerium oxide and the petal-shaped cerium oxide powder as the aggregate thereof according to the first aspect of the present invention are characterized by having an average particle diameter of less than 20 μm and an average aspect ratio (average primary particle diameter/average thickness) of 2 to 80.

The method for producing the plate-like cerium oxide and the petal-like cerium oxide powder as the aggregate thereof according to the second aspect of the invention is a method for producing the plate-like cerium oxide and the petal-like cerium oxide powder as the aggregate thereof according to the first aspect of the invention, characterized in that an aqueous solution containing cerium nitrate or cerium chloride, sodium bicarbonate or sodium carbonate, and water is prepared so that the molar ratio of carbonate ions to cerium ions is in the range of 1.5 to 5, the temperature of the aqueous solution is maintained in the range of 10 to 40 ℃, cerium carbonate particles are precipitated from the aqueous solution, and the resulting solution is calcined.

A method for producing a plate-like cerium oxide and a petal-like cerium oxide powder as an aggregate thereof according to a third aspect of the invention are the method for producing the plate-like cerium oxide and the petal-like cerium oxide powder as an aggregate thereof according to the first aspect of the invention, characterized in that an aqueous solution containing cerium nitrate or cerium chloride, sodium bicarbonate or sodium carbonate, and water is prepared so that the molar ratio of carbonate ions to cerium ions is in the range of 1.5 to 5, the temperature of the aqueous solution is maintained in the range of 0 to 10 ℃, cerium carbonate particles are precipitated from the aqueous solution, and the resulting solution is calcined.

In the second or third invention, it is preferable that the aqueous solution contains an alcohol compound (fourth invention).

The plate-like cerium oxide and the petal-like cerium oxide powder as the aggregate of the plate-like cerium oxide according to the fifth invention are characterized in that the surface of the plate-like cerium oxide and the petal-like cerium oxide powder as the aggregate of the plate-like cerium oxide according to the first invention is coated with one or two or more compounds selected from the group consisting of a polysiloxane represented by the following general formula (1), an alkylalkoxysilane compound represented by the following general formula (2), an alkyltitanate compound represented by the following general formula (3), a fluorine compound represented by the following general formula (4), a fluorine compound represented by the following general formula (5) and a fluorine compound represented by the following general formula (6).

(wherein m is an integer of 1 or more, n is an integer of 0 or more, and R is₁～R₂Hydrogen, alkyl, alkoxy or phenyl, which may be the same).

R₁Si(OR₂)₃…(2)

(in the formula, R₁And R₂Is a saturated hydrocarbon group having 1 or more carbon atoms).

(R₁COO)_aTi(OR₂)_b…(3)

(in the formula, R₁And R₂Is a saturated hydrocarbon group having 1 or more carbon atoms. Each of a and b is an integer of 1 to 3, and has a relationship of a + b being 4. To say thatIt is to be noted that the alkyl group shown here may be linear or branched and may have a monodisperse chain length or a polydisperse chain length. )

CF₃(CF₂)_n CH₂CH₂Si(OR₁)₃…(4)

(in the formula, R₁Is a saturated hydrocarbon group having 1 or more carbon atoms, n is an integer of 1 or more)

(wherein n is an integer of 4 or more, M is 1 or 2, and M is an alkali metal, an ammonium group, or a diethanolammonium group).

(wherein n is an integer of 4 or more, and M is an alkali metal, an ammonium group, or a diethanolammonium group).

The cosmetic according to a sixth aspect of the invention is characterized by containing the plate-like cerium oxide of the first aspect and the petal-like cerium oxide powder as an aggregate thereof or the plate-like cerium oxide after the coating treatment of the fifth aspect and the petal-like cerium oxide powder as an aggregate thereof.

Effects of the invention

According to the present invention, there can be provided a plate-like cerium oxide having an average primary particle diameter of less than 20 μm and a petal-like cerium oxide powder as an aggregate thereof, wherein the plate-like cerium oxide and the petal-like cerium oxide powder as the aggregate thereof can be produced by precipitating and growing cerium carbonate octahydrate particles in a mixed solution of a cerium nitrate or cerium chloride solution, sodium bicarbonate or sodium carbonate, and water, and then firing the particles.

In addition, the cosmetic containing the plate-like cerium oxide of the first invention and the petal-like cerium oxide powder as an aggregate thereof or the coated plate-like cerium oxide of the fifth invention and the petal-like cerium oxide powder as an aggregate thereof has an ultraviolet shielding effect and is excellent in feeling of use.

Drawings

Fig. 1 is a scanning electron micrograph of the plate-shaped cerium oxide powder produced in example 1.

Fig. 2 is a scanning electron micrograph of petaloid cerium oxide powder as a plate-like aggregate produced in example 2.

Fig. 3 is a scanning electron micrograph of the cerium oxide powder produced in comparative example 1.

Fig. 4 is a scanning electron micrograph of the cerium oxide powder produced in comparative example 2.

Fig. 5 is a scanning electron micrograph of the cerium oxide powder produced in comparative example 3.

Detailed Description

Next, specific embodiments of the plate-like cerium oxide and the petal-like cerium oxide powder as the aggregate thereof, the method for producing the same, the plate-like cerium oxide after the coating treatment, the petal-like cerium oxide powder as the aggregate thereof, and the cosmetic according to the present invention will be described with reference to the drawings.

The plate-like cerium oxide and the petal-like cerium oxide powder as an aggregate thereof of the present invention are cerium oxide powders having an average primary particle diameter of less than 20 μm. In the present invention, the average thickness of the cerium oxide powder is preferably 0.2 to 4 μm. When the average thickness is less than 0.2 μm, the thickness of the obtained cerium oxide powder becomes insufficient, and thus, the cerium oxide powder is easily broken. On the other hand, when it exceeds 4 μm, the visible light transparency is lowered.

The average primary particle size of the plate-like cerium oxide and the petal-like cerium oxide powder as an aggregate thereof of the present invention can be measured by the following procedure: the plate-like particles and the petal-like particles as an aggregate thereof were observed by a Scanning Electron Microscope (SEM), and the diameters (major axis and minor axis) of the plate-like particles of arbitrary 20 plate-like particles or the petal-like particles constituting the aggregate thereof were measured to calculate the average value thereof.

The average thickness of the plate-like cerium oxide and the petal-like cerium oxide powder as an aggregate thereof of the present invention can be measured by the following procedure: the plate-like particles and the petal-like particles as an aggregate thereof were observed by a Scanning Electron Microscope (SEM), and the thicknesses of arbitrary 20 plate-like particles or the plate-like particles of the petal-like particles constituting the aggregate thereof were measured to calculate the average value thereof.

In the present invention, the aspect ratio (average primary particle diameter/average thickness) of the plate-like cerium oxide and the petal-like cerium oxide powder as an aggregate thereof is 2 to 80. When the aspect ratio is less than the lower limit value 2, the obtained cerium oxide powder is not formed into a plate shape. On the other hand, if it exceeds the upper limit value of 80, the thickness of the obtained cerium oxide powder does not become a thickness that only retains the particle shape.

The method for producing the plate-like cerium oxide and the petal-like cerium oxide powder as the aggregate thereof of the present invention is as follows: cerium carbonate particles are precipitated and grown by mixing sodium bicarbonate or carbonate ions so that the molar ratio of the carbonate ions to cerium ions in a cerium nitrate or cerium chloride solution is in the range of 1: 1.5 to 1: 5, and allowing the mixed solution to stand or stir at a temperature in the range of 0 to 40 ℃ for 30 minutes or more, and cerium carbonate octahydrate is obtained and fired to produce a plate-like or petal-like cerium oxide powder as an aggregate thereof. (petal-shaped cerium oxide as an aggregate of plate-shaped cerium oxide was obtained at 0 to 10 ℃ and plate-shaped cerium oxide was obtained at 10 to 40 ℃)

The molar ratio of the carbonate ion to the cerium ion is preferably more than 1.5 and less than 5 from the viewpoint of maintaining the form of a plate or petal and production efficiency. When the molar ratio of carbonate ions to cerium ions is less than 1.5, the yield decreases, the productivity decreases, and the morphology of the plate-like particles becomes irregular. When the molar ratio of carbonate ions to cerium ions exceeds 5, the ionic strength is too high, and the particles aggregate.

As the solvent for dissolving the cerium nitrate or chloride and the sodium hydrogencarbonate or sodium carbonate, water is used, or a mixed solvent containing water may be used. The solvent to be mixed with water may be any water-soluble compound, and is preferably an alcohol compound. Examples of the alcohol compound include monohydric alcohols such as methanol, ethanol, propanol, and butanol, and polyhydric alcohols such as polyethylene glycol, ethylene glycol, polyethylene, and glycerol.

In the case of using such an alcohol-based mixed solvent, the mass ratio of the alcohol-based solvent to the water in the solvent is preferably less than 50%, more preferably 30% or less. When the mass ratio is 50% or more, sodium bicarbonate or sodium carbonate does not dissolve, and the uniformity of the obtained plate-like and petal-like cerium oxide powder as an aggregate thereof is lowered.

When the temperature of the mixed solution is less than 0 ℃, the progress of the growth reaction of the cerium carbonate particles in the mixed solution is slowed, and thus, the petal-shaped cerium oxide powder of the plate-like or aggregated body thereof cannot be obtained with a sufficient yield. On the other hand, when the temperature of the mixed solution exceeds 40 ℃, the growth reaction of the cerium carbonate octahydrate particles proceeds rapidly, and therefore, the particles become elongated and have a needle-like shape, and thus, a petal-shaped cerium oxide powder of a plate shape and an aggregate thereof cannot be obtained. When the time for growing the cerium carbonate particles is less than 30 minutes, the particles are grown, and therefore, crystallinity of the obtained cerium carbonate octahydrate particles is deteriorated, and amorphous particles are formed, and thus, the petal-shaped cerium oxide powder having a plate shape and an aggregate thereof cannot be obtained.

The conditions for firing the plate-like and petal-like cerium carbonate octahydrate particles as an aggregate thereof are preferably such that the firing temperature is in the range of 350 to 1000 ℃, more preferably 400 to 700 ℃. When the firing temperature is less than 350 ℃, the cerium carbonate octahydrate tends to remain without being completely oxidized, and when the firing temperature exceeds 1000 ℃, the particles tend to be sintered. The firing time is preferably set within a range of 0.5 to 5 hours.

Next, the hydrophobic plate-like cerium oxide powder of the present invention and petal-like cerium oxide powder as an aggregate thereof will be described. The hydrophobic plate-like cerium oxide powder and the petal-like cerium oxide powder as an aggregate thereof according to the present invention can be obtained by: the surface of the petal-shaped cerium oxide powder of the plate-like shape and the aggregate thereof of the present invention is coated with the polysiloxane, the alkylsilane compound, the alkyltitanate compound, the fluorine compound, or the like.

In addition to the above compounds, various surface treatments known in the art may be performed. These treatments may be used in combination of a plurality of kinds.

In addition, as a treatment method for coating the surface of the hydrophobic compound, the following method is generally used: the pigment subjected to coating treatment is stirred by a suitable homogenizer, and after the compound for surface coating is added dropwise or sprayed by a liquid, it is strongly stirred at a high speed for a certain period of time. Then, the reaction surface is coated by heating to 80 to 200 ℃ for aging while continuously stirring. Alternatively, the following methods may be mentioned: the surface-coating compound is dissolved in advance in an alcohol such as ethanol, isopropanol, isobutanol, or the like, a hydrocarbon organic solvent such as toluene, n-hexane, cyclohexane, or the like, a polar organic solvent such as acetone, ethyl acetate, butyl acetate, or the like, stirred in the solution, and after the cosmetic pigment is added and stirred, the organic solvent is completely evaporated and removed, and then heated to 80 to 200 ℃ to be matured, thereby performing a reaction surface coating treatment.

In addition, as the mixing and dispersing method, an appropriate method can be selected depending on the concentration, viscosity, and the like of the solution. As suitable examples, there can be selected a method using a mixer such as a dispersant, a Henschel homogenizer, a Lodige homogenizer (Lodige mixer), a kneader, a V-type mixer, a roll mill, a bead mill, or a twin-screw kneader, and a method of spray drying in which an aqueous solution and a pigment are sprayed into heated air to continuously remove water. In addition, in the case of pulverization, a common pulverizer such as a hammer mill, a ball mill, a sand mill, or a jet mill may be used. Any of these pulverizers can be used to obtain a pulverized product of the same quality, and is not particularly limited.

In this case, the mass ratio of the component of the compound used for the surface coating treatment of the pigment is preferably 0.5 to 30% by mass relative to the pigment to be subjected to the coating treatment. When the mass ratio is less than 0.5% by mass, the lasting effect and uniform adhesion to the skin are insufficient, and when it exceeds 30% by mass, the feeling is extremely greasy and the feeling is wet, which is not preferable as a cosmetic.

Next, the cosmetic of the present invention will be described. The cosmetic of the present invention has an excellent ultraviolet shielding effect by incorporating the petal-shaped cerium oxide powder of the plate-like shape and the aggregate thereof of the present invention. Further, since the petal-shaped cerium oxide powder of the plate-like shape and the aggregate thereof of the present invention is cerium oxide having an average primary particle of less than 20 μm, the cosmetic containing the powder has a good feel when applied to the skin and a good feeling in use, as compared with conventional cosmetics containing cerium oxide. The cosmetic formulation can be used for skin care cosmetics such as lotions and lotions, makeup cosmetics such as foundations and lipsticks, hair cosmetics, etc., and particularly preferred is sunscreen cosmetics. The amount of the additive is not particularly limited, but is preferably 0.1 to 70% by mass.

The cosmetic composition of the present invention has a remarkable effect by combining an organic ultraviolet-screening agent and a fine-particle inorganic ultraviolet-screening agent. The organic ultraviolet screening agent is preferably one or more selected from oxybenzone (オキシベンゾン), octyl methoxycinnamate, 4-tert-4' -methoxybenzoylmethane, and diethylamino hydroxybenzoylbenzoic acid hexyl ester. The amount of the organic ultraviolet shielding agent is not particularly limited, but is preferably 0.1 to 40% by mass. The inorganic ultraviolet-screening agent of the fine particles is preferably titanium oxide and/or zinc oxide, and more preferably fine particles of titanium oxide and/or zinc oxide having an average particle diameter of 0.05 μm or less. The amount of the inorganic ultraviolet shielding agent to be incorporated into the fine particles is not particularly limited, but is preferably 0.1 to 50% by mass.

In the cosmetic of the present invention, components generally used in cosmetics, such as powders, surfactants, oils, gelling agents, polymers, cosmetic components, moisturizers, pigments, preservatives, perfumes, and the like, can be used within a range not impairing the effects of the present invention.

The form of the cosmetic of the present invention may be any form such as powder, emulsion, paste, stick, solid, spray, multi-layer separation type, and the like.

Examples

Next, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples.

(example 1)

54.6 parts by mass of sodium hydrogencarbonate was dissolved in 1200 parts by mass of water, and the mixture was stirred by three motors 200. 197.7 parts by mass of an aqueous solution of cerium chloride (cerium concentration: 18.7% by mass) was added to the solution. The molar ratio of cerium ions to carbonate ions was 1: 4.3. The mixed solution was stirred at a temperature of 18 ℃ for 1 hour to obtain a hydrate solution containing plate-like cerium carbonate octahydrate particles. The plate-like cerium carbonate octahydrate particles were recovered from the obtained hydrate solution by filtration, washed and dried, and then the plate-like cerium carbonate octahydrate particles were fired at 400 ℃ for 1 hour in the air to obtain plate-like cerium oxide powder.

The cerium oxide powder obtained in example 1 was observed with a Scanning Electron Microscope (SEM). An SEM photograph of the obtained cerium oxide powder is shown in fig. 1. As shown in the figure, it was confirmed that the obtained cerium oxide powder was plate-like particles. In addition, arbitrary 20 plate-shaped cerium oxide powders in fig. 1 were observed, and the average primary particle size and the average thickness of the plate-shaped cerium oxide powders were measured. As a result, it was confirmed that the plate-like cerium oxide powder had an average primary particle size of 7.1 μm and an average primary particle size of less than 20 μm. Further, it was confirmed that the average thickness of the plate-like cerium oxide powder was 0.51 μm and in the range of 0.2 to 4 μm. In addition, it was confirmed that the aspect ratio (average primary particle size/average thickness) of the plate-like cerium oxide powder was 13.9.

(example 2)

Petal-shaped cerium oxide powder, which was an aggregate of plate-shaped particles, was obtained in the same manner as in example 1, except that the temperature of the mixed solution was set to 7 ℃.

The cerium oxide powder obtained in example 2 was observed by SEM. An SEM photograph of the obtained cerium oxide powder is shown in fig. 2. As shown in the figure, it was confirmed that the obtained cerium oxide powder had a large amount of petaloid cerium oxide powder as an aggregate of plate-like particles. Further, the plate-shaped cerium oxide constituting an arbitrary 20 petal-shaped cerium oxide powder in fig. 2 was observed, and the average primary particle diameter and the average thickness of the plate-shaped cerium oxide were measured. As a result, it was confirmed that the plate-like cerium oxide powder had an average primary particle size of 2.1 μm, an average thickness of 0.41 μm, and an aspect ratio of 5.1. Incidentally, the average particle diameter of the petal-shaped cerium oxide powder as an aggregate of the plate-shaped cerium oxide was 5.4. mu.m.

(example 3)

Cerium oxide powder was obtained in the same manner as in example 1, except that a mixed solution of 1200 parts by mass of water and 60 parts by mass of polyethylene glycol (average molecular weight: 200) was used instead of 1200 parts by mass of water.

The cerium oxide powder obtained in example 3 was observed by SEM, and it was confirmed that the cerium oxide powder was plate-like cerium oxide powder, and had an average primary particle size of 18.7 μm, an average thickness of 1.2 μm, and an aspect ratio of 15.6.

(example 4)

Cerium oxide powder was obtained in the same manner as in example 1, except that the cerium chloride solution was left standing without stirring instead of the three-motor 200 revolutions.

The cerium oxide powder obtained in example 4 was observed by SEM, and it was confirmed that the cerium oxide powder was plate-like cerium oxide powder, and had an average primary particle size of 4.7 μm, an average thickness of 0.34 μm, and an aspect ratio of 13.8.

Comparative example 1

Cerium oxide powder was obtained in the same manner as in example 1, except that the temperature of the mixed solution was set to 43 ℃.

The cerium oxide powder obtained in comparative example 1 was observed by SEM. The obtained cerium oxide powder is shown in fig. 3. As shown in the figure, it was confirmed that the cerium oxide powder obtained in comparative example 1 was a long, thin, needle-like powder.

Comparative example 2

Cerium oxide powder was obtained in the same manner as in example 1, except that 16.8 parts by mass of sodium hydrogencarbonate was used instead of 54.6 parts by mass of sodium hydrogencarbonate. The molar ratio of cerium ions to carbonate ions of the aqueous solution prepared was 1: 1.33.

The cerium oxide powder obtained in comparative example 2 was observed by SEM. The obtained cerium oxide powder is shown in fig. 4. As shown in the figure, it was confirmed that the cerium oxide powder obtained in comparative example 2 was large particles having an average particle size of 20 μm or more.

Comparative example 3

Cerium oxide powder was obtained in the same manner as in example 1, except that 67.2 parts by mass of sodium hydrogencarbonate was used instead of 54.6 parts by mass of sodium hydrogencarbonate. The molar ratio of cerium ions to carbonate ions of the aqueous solution prepared was 1: 5.33.

The cerium oxide powder obtained in comparative example 3 was observed by SEM. The obtained cerium oxide powder is shown in fig. 5. As shown in the figure, it was confirmed that the cerium oxide powder obtained in comparative example 3 was amorphous particles, and aggregation was observed.

Production example 1 production example of silicon Compound-coated plate-shaped cerium oxide

1000 parts by mass of the plate-like cerium oxide obtained in example 1 was charged into a Henschel homogenizer, and then a solution prepared by dissolving 20.4 parts by mass of polymethylhydrosiloxane in 125 parts by mass of isopropyl alcohol was mixed dropwise and mixed thoroughly with the plate-like cerium oxide. Then, the Henschel homogenizer was heated and depressurized to remove isopropanol. The pigment powder was taken out from the Henschel homogenizer, pulverized, and subjected to heat treatment to obtain titanium oxide in which the silicon compound was treated at 2 mass%. Titanium oxide, sericite, talc, mica, red iron oxide, yellow iron oxide, and black iron oxide were subjected to the same surface coating treatment in the same steps to obtain various samples.

Production example 2 production example of cerium oxide plate coated with alkylsilane Compound

Samples were obtained in the same manner as in production example 1, except that n-octyltriethoxysilane was used instead of the polymethylhydrosiloxane of production example.

Production example 3 production example of cerium oxide sheet coated with alkyltitanate Compound

A sample was obtained in the same manner as in production example 1 except that isopropyl triisostearoyl titanate was used instead of the polymethylhydrosiloxane of production example.

Production example 4 production example of fluorine Compound-coated plate-shaped cerium oxide

Samples were obtained in the same manner as in production example 1, except that tridecafluorooctyltriethoxysilane was used instead of the polymethylhydrosiloxane of production example.

Here, in order to confirm the water and oil repellency of the cosmetic pigment powder of this example, the contact angle with water and the contact angle with liquid paraffin of the plate-like cerium oxide treated in production examples 1 to 4 were measured using a goniometer-type contact angle measuring device manufactured by elmer. The results of measuring the contact angles of production examples 1 to 4 are shown in table 1.

TABLE 1

From the results shown in table 1, by coating the surface with a water-repellent compound, a plate-like cerium oxide having good water/oil repellency can be obtained.

Example 5 preparation of powder Foundation

According to the recipe shown in table 2 and the following manufacturing method, a powder foundation was obtained. The unit of the amount blended in the table is mass%.

TABLE 2

Note 1: KSP-100 (manufactured by Xinyue chemical industry Co., Ltd.)

Note 2: CELLULOBEADS D-10 (manufactured by Dadong chemical industry Co., Ltd.)

Note 3: KSG-16 (manufactured by Xinyue chemical industry Co., Ltd.)

The manufacturing method comprises the following steps: and (3) using a homogenizer to fully mix the component A, slowly adding the uniformly heated and dissolved component B, further mixing, crushing, sieving, and pressing in a metal container by using a mold to obtain the product.

Comparative example 4

A product was obtained in the same manner as in example 5, except that silicon-treated particulate titanium oxide was used instead of the silicon-treated plate-like cerium oxide produced in production example 1.

Comparative example 5

A product was obtained in the same manner as in example 5, except that the silicon-treated fine particulate zinc oxide was used instead of the silicon-treated plate-like cerium oxide produced in production example 1.

Comparative example 6

A product was obtained in the same manner as in example 5, except that silicon-treated fine-particle cerium oxide was used instead of the silicon-treated plate-like cerium oxide produced in production example 1. The fine-particle cerium oxide used in comparative example 6 was セリガ - ド SC-6832 manufactured by Dadonghua chemical industries, Ltd.

The cosmetics prepared in example 5 and comparative examples 4 to 6 were subjected to a sensory evaluation test for feeling of use, using 10 female members. The test was conducted in the form of a questionnaire, and the number of points between 0 and 5 points was evaluated for each item, and the results were expressed as the average point of all the members, with 0 points being the evaluation difference and 5 points being the evaluation excellence, and were expressed as numerical values. Therefore, a higher point number indicates an excellent evaluation. The cosmetic is applied in the form of applying an emulsion-like foundation liquid. The results are shown in Table 3.

TABLE 3

From the results in table 3, it is understood that example 5 is excellent in all items of the feeling of use, the transparency, and the sunscreen effect (ultraviolet shielding effect) at the time of coating. In comparative example 4, since the silicon-treated particulate titanium oxide was blended, the sunscreen effect (ultraviolet shielding effect) was excellent, but the feeling of use and transparency at the time of coating were deteriorated. In comparative example 5, since the silicon-treated fine particulate zinc oxide was added, the transparent feeling and the sunscreen effect (ultraviolet shielding effect) were excellent, but the result was that the feeling of use at the time of coating was deteriorated. In comparative example 6, since the silicon-treated particulate cerium oxide was blended, the plate-like cerium oxide of the present invention was superior in transparency and sunscreen effect (ultraviolet shielding effect), but was inferior in feeling of use at the time of coating, and thus had superior characteristics as compared with the conventional cerium oxide.

(example 6)

A W/O type liquid foundation was produced according to the recipe shown in table 4 and the following production method. The unit of the amount blended in the table is mass%.

TABLE 4

Note 1: BY22-008M (Dongli Dow Corning Co., Ltd.)

Note 2: KSG-16 (manufactured by shin Yue chemical industries Co., Ltd.)

Note 3: plastic powder D-800 (manufactured by eastern color paint Co., Ltd.)

The manufacturing method comprises the following steps: the ingredient B was thoroughly mixed using a homogenizer. On the other hand, component A was heated to 80 ℃ and mixed well to achieve homogeneity. Ingredient B was slowly added thereto with stirring, slowly cooled to 50 ℃. Subsequently, the component C was heated to 80 ℃ to be uniformly dissolved, and then slowly cooled to 50 ℃. Component C was added to component a with stirring, and the mixture was further stirred sufficiently and cooled to room temperature. The resulting solution was filled into a container to obtain a product.

The obtained liquid foundation was excellent in all of the feeling of use, transparency, and ultraviolet shielding effect when applied.

(example 7)

A W/O type sunscreen cosmetic was prepared according to the formulation shown in Table 5 and the following production method. The unit of the amount blended in the table is mass%.

TABLE 5

Note 1: CELLULOBEADS D-5 (manufactured by Dadong chemical industry Co., Ltd.)

Note 2: KSG-16 (manufactured by Xinyue chemical industry Co., Ltd.)

The manufacturing method comprises the following steps: ingredient a was heated to 80 ℃ and mixed thoroughly to achieve homogeneity. To this was slowly added component B with stirring, slowly cooled to 50 ℃. Subsequently, the component C was heated to 80 ℃ to be uniformly dissolved, and then slowly cooled to 50 ℃. Component C was added to component a with stirring, and the mixture was further stirred sufficiently and cooled to room temperature. The resulting solution was filled into a container to obtain a product.

The obtained W/O type sunscreen cosmetic composition is excellent in all of the feeling of use, transparency and ultraviolet shielding effect at the time of application.

(example 8)

An O/W type liquid foundation was prepared according to the formulation shown in table 6 and the following production method. The unit of the amount blended in the table is mass%.

TABLE 6

The manufacturing method comprises the following steps: ingredients A, C were mixed thoroughly at 80 ℃. The component B was added to the component C under stirring, and after thorough mixing, the component a was slowly added from above, slowly cooled, and then filled into a container to obtain a product.

The obtained O/W type liquid foundation was excellent in all of the feeling of use, transparency and ultraviolet shielding effect at the time of application.

Industrial applicability

The plate-like cerium oxide of the present invention, the petal-like cerium oxide powder as an aggregate thereof, and the coated powder obtained by coating the surface of the plate-like cerium oxide powder with a hydrophobic compound are blended with a cosmetic such as a powder foundation or a liquid foundation, and therefore, a cosmetic excellent in feeling of use, transparency, and ultraviolet shielding effect when applied to the skin can be obtained.

Claims

1. A plate-like cerium oxide and a petal-like cerium oxide powder as an aggregate thereof, characterized by having an average particle diameter of less than 20 μm and an average aspect ratio of 2 to 80.

2. A process for producing plate-like cerium oxide and petal-like cerium oxide powder as an aggregate thereof, which comprises the step of producing plate-like cerium oxide and petal-like cerium oxide powder as an aggregate thereof according to claim 1,

an aqueous solution containing cerium nitrate or cerium chloride, sodium bicarbonate or sodium carbonate, and water is prepared so that the molar ratio of carbonate ions to cerium ions is in the range of 1.5 to 5, and cerium carbonate particles are precipitated from the aqueous solution by maintaining the temperature of the aqueous solution in the range of 10 to 40 ℃, followed by firing.

3. A process for producing plate-like cerium oxide and petal-like cerium oxide powder as an aggregate thereof, which comprises the step of producing plate-like cerium oxide and petal-like cerium oxide powder as an aggregate thereof according to claim 1,

an aqueous solution containing cerium nitrate or cerium chloride, sodium bicarbonate or sodium carbonate, and water is prepared so that the molar ratio of carbonate ions to cerium ions is in the range of 1.5 to 5, and cerium carbonate particles are precipitated from the aqueous solution by maintaining the temperature of the aqueous solution in the range of 0 to 10 ℃, followed by firing.

4. The method for producing plate-like cerium oxide and petal-like cerium oxide powder as an aggregate thereof according to claim 2 or 3, wherein the aqueous solution contains an alcohol compound.

5. A plate-like cerium oxide and a petal-like cerium oxide powder as an aggregate thereof, characterized in that the surface of the plate-like cerium oxide and the petal-like cerium oxide powder as an aggregate thereof according to claim 1 is coated with one or two or more compounds selected from the group consisting of a polysiloxane represented by the following general formula (1), an alkylalkoxysilane compound represented by the following general formula (2), an alkyltitanate compound represented by the following general formula (3), fluorine compounds represented by the following general formula (4), the following general formula (5) and the following general formula (6),

wherein m is an integer of 1 or more, n is an integer of 0 or more, and R is₁～R₂Hydrogen, alkyl, alkoxy or phenyl, which may be the same,

R₁Si(OR₂)₃…(2)

in the formula, R₁And R₂Is a saturated hydrocarbon group having 1 or more carbon atoms,

(R₁COO)_aTi(OR₂)_b…(3)

in the formula, R₁And R₂A saturated hydrocarbon group having 1 or more carbon atoms, a and b are each an integer of 1 to 3, and a + b is 4, and the alkyl group shown here may be linear or branched, and may have a monodisperse distribution chain length or a polydisperse distribution chain length,

CF₃(CF₂)_nCH₂CH₂Si(OR₁)₃…(4)

in the formula, R₁Is a saturated hydrocarbon group having 1 or more carbon atoms, n is an integer of 1 or more,

wherein n is an integer of 4 or more, M is 1 or 2, M is an alkali metal, an ammonium group, a diethanolammonium group,

wherein n is an integer of 4 or more, and M is an alkali metal, an ammonium group, or a diethanolammonium group.

6. A cosmetic comprising the plate-like cerium oxide according to claim 1 and a petal-like cerium oxide powder as an aggregate thereof or the coated plate-like cerium oxide according to claim 5 and a petal-like cerium oxide powder as an aggregate thereof.