JP2991952B2 - Cerium oxide and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ceric oxide surface-treated with a fluorinated surfactant and a method for producing the same.

[0002] Cerium oxide is used in abrasives, catalysts, ultraviolet absorbers, decolorizing agents for glass, cosmetics and the like. The present invention is particularly applicable to heat-resistant films, plastics and paints. It is another object of the present invention to provide ceric oxide which exhibits an ultraviolet absorbing effect more effectively when used as an internal additive in cosmetics and the like.

[0003]

2. Description of the Related Art As a technique for imparting an ultraviolet absorbing effect to a film or plastic, it has been conventionally known to mix an organic ultraviolet absorbing agent with plastics. However, when the organic ultraviolet absorber is exposed to a high temperature during molding, it volatilizes and decomposes itself, and its effect is significantly reduced. In particular, in the case of a material requiring extremely high temperature for molding, such as a fluororesin, an organic ultraviolet absorber cannot be used in practice.

Therefore, in order to impart an ultraviolet absorbing effect to a resin requiring high-temperature processing, it is necessary to mix an inorganic ultraviolet absorbing agent, for example, titanium oxide, zinc oxide, iron oxide, ceric oxide and the like. It is considered effective.

However, when using titanium oxide, the resin itself is deteriorated due to generation of radicals of titanium oxide, and when using zinc oxide, the water resistance of the obtained resin composition is reduced. Further, since iron oxide itself is colored, application to colorless and transparent uses other than cosmetics cannot be expected.

[0006] As described above, when inorganic UV absorbers are used in a mixture with plastics, none of them can satisfy all physical properties.

On the other hand, examples in which a fluorine-based surfactant is applied to plastics, paints, photoreceptors, magnetic toners and the like are disclosed in JP-A-55-50251, JP-A-55-127564, and JP-A-57-127564. No. 101302, JP-A-58-62650, JP-A-63-139952
No., JP-A-63-69631, JP-A-63-210156, JP-A-3-1
No. 80334, JP-A-6-95299, JP-A-6-138622, JP-A-Hei.
Although there is no spare time in enumeration such as 6-240145, none of these are used as the surface treatment agent as shown in the present invention. Examples using a fluorine-based surfactant as a surface treatment agent are described in JP-A-56-9177, JP-A-59-19235, and
-246212, JP-A-4-292428, JP-A-5-151968, JP-A-6-303071, JP-A-6-211631, JP-A-6-345632, etc. It does not utilize the heat resistance of the fluorine-based surfactant and the property of blocking the effect of the pigment on the resin. Furthermore, Japanese Patent Application Laid-Open No. 2-285081 discloses the use of cerium and a fluorine-based surfactant, which uses ceric ammonium nitrate as an etching solution for a chromium film.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, the present inventors have intensively studied to obtain a ceric oxide-based ultraviolet absorber which has excellent ultraviolet absorption and does not adversely affect plastics. Was done.

When ceric oxide powder not subjected to a surface treatment is mixed with plastics, there is a problem that the resin is oxidized at the time of high-temperature processing and discolored to brown.

In addition, the inventors of the present invention disclosed in Japanese Patent Application Laid-Open No. 1-306435, an anionic surfactant was adsorbed on a cationic aqueous ceric oxide sol and dispersed in an organic solvent. Further, in the invention of JP-A-4-300644, a surface treatment of a cationic aqueous ceric oxide sol with a phosphorus compound, and then a ceric oxide cerium oxide adsorbed with a cationic surfactant is used. Proposed.

However, all of the inventions have a problem that the surfactant is carbonized during the high temperature processing of plastics, and at the same time, the plastics are remarkably discolored to brown.

[0012]

According to the present invention, in order to solve the above-mentioned problems, ceric oxide has been further studied, and as a result, a means for solving the problems has been found. The present invention provides ceric oxide which exhibits excellent ultraviolet absorption even when it is used and does not adversely affect plastics.

That is, the present invention provides ceric oxide surface-treated with a fluorine-containing surfactant having a perfluorocarbon chain.

[0014]

The ceric oxide used in the present invention may be a ceric oxide slurry finely pulverized by a wet process or a cationic aqueous oxidized slurry disclosed by the present inventors in the invention of JP-A-1-148710. Dicerium sol,
Anionic aqueous ceric oxide sol disclosed in the invention of JP-A-4-300644 is exemplified. From the viewpoint of transparency when mixed with plastics, a sol having a small particle size is most preferable.

The cerium oxide of the present invention may be a mixture of cerium oxide alone or aluminum, zirconium, iron, silicon or the like in order to modify various physical properties such as resin. Good. However, it is necessary that ceric oxide be contained at 70% by weight or more as CeO ₂ . Below this, the ultraviolet absorbing effect of the present invention cannot be expected.

The fluorosurfactant used in the present invention may be any surfactant having a perfluorocarbon chain, such as a perfluoroalkyl sulfonate, a perfluoroalkyl carboxylate, and a perfluorocarbon sulfonate. Monoalkyl fluoroalkyl phosphates, perfluoroalkyltrimethylammonium salts, organosiloxanes having a perfluoro group or derivatives thereof, and the like. Among these, a perfluoroalkyl sulfonate having high heat resistance is particularly preferable when mixed with a resin that requires high-temperature processing such as a fluororesin.

As a method of surface-treating ceric oxide finely pulverized by a wet method or the like, for example, a fluorinated surfactant of the present invention is dissolved in a solvent such as water or methanol, and this is added to a ceric oxide slurry. Or a method in which a fluorine-based surfactant is directly added to the slurry, stirred, and dried. The drying method may be a general drying method such as standing drying, spray drying, or infrared drying. When a perfluoroalkyl sulfonate having high heat resistance is used, heat treatment may be performed at 400 ° C. or lower.

When the ceric oxide sol is subjected to a surface treatment, a fluorine-based surfactant is directly added, or a solution previously dissolved in a solvent such as water or methanol is added, followed by sufficient stirring. Thereby, the surface of the ceric oxide sol is hydrophobized to form a slurry. The ceric oxide of the present invention is obtained by washing, filtering and drying the slurry. The point is that the fluorinated surfactant may be adsorbed on ceric oxide, and the present invention is not limited to these surface treatment methods.

With regard to the amount of the fluorine-based surfactant, the smaller the particle size of the ceric oxide, the smaller the amount of the fluorine-based surfactant to be used. The amount used will increase. The amount used is in the range of 12 to 100% by weight based on the CeO ₂ amount of ceric oxide. The amount of this surfactant deviates from this range,
If the amount is less than 12% by weight, oxidation of the resin cannot be completely prevented when mixed with plastics. On the other hand, the excessive use of the surfactant in excess of 100% by weight is not preferable because the surplus surfactant is present alone without being adsorbed on the surface of ceric oxide. .

The plastics applicable to the present invention include ethylene tetrafluoride resin, ethylene tetrafluoride-propylene hexafluoride copolymer resin, ethylene tetrafluoride-perfluoroalkyl vinyl ether copolymer resin, and ethylene tetrafluoride resin. Various fluorine resins including ethylene copolymer resin, ethylene trifluoride ethylene resin, vinylidene fluoride resin, acrylic resin, vinyl chloride resin, vinyl acetate resin, polyethylene resin, polypropylene resin, ionomer resin, polystyrene resin, acrylonitrile / styrene Resin, A
BS resin, ethylene / vinyl chloride copolymer resin, ethylene / vinyl acetate copolymer resin, vinylidene chloride resin, chlorinated polyethylene resin, chlorinated polypropylene resin, coumarone resin, ketone resin, phenoxy resin, polycarbonate resin, polyimide resin, polyethylene terephthalate resin And the like, but are not limited thereto.

The amount of surface-treated ceric oxide added to these plastics varies depending on the type of resin, but is generally in the range of 0.1 to 30% by weight based on the amount of resin. If the content is out of this range and less than 0.1% by weight, a sufficient ultraviolet absorbing effect cannot be obtained. If it exceeds 30% by weight, the physical properties of the resin itself are impaired. The ceric oxide of the present invention exerts its effects best when used in plastics, but exhibits an excellent ultraviolet absorbing effect even when added to cosmetics, films and paints.

[0022]

The present invention will be further described below with reference to examples of the present invention, but the present invention is not limited to these examples. Also,
All percentages are by weight unless otherwise specified.

(Example 1) Cerous carbonate (CeO ₂ 32.7)
%, Particle diameter of 5 to 10 μm), 2139 g of water was added, and the mixture was pulverized by a wet pulverizer to an average particle diameter of 1 μm. To this was added 131 g of hydrogen peroxide (34.5% H ₂ O ₂ ). After stirring this at room temperature for 1 hour, the solution was heated to 93 ° C., and the reaction was carried out while stirring for another 1 hour. After the reaction, the product became a yellow-white gel slurry. The slurry was dried at 60 ° C., and X-ray diffraction of the obtained powder was measured. As a result, the powder was identified as ceric oxide. This slurry was further pulverized by a wet pulverizer to an average particle diameter of 0.5 μm. Next, 35 g of potassium perfluoroalkylsulfonate (C ₈ F ₁₇ SO ₃ K) was directly added to 1000 g of the ceric oxide slurry (CeO ₂ 11.8%), followed by stirring. After the reaction, the product was filtered and washed, and water was added to the obtained wet cake to 400 g. After stirring, this was spray-dried. Thus, 141 g of ceric oxide of the present invention was obtained. When this was analyzed, CeO ₂ 75.7
% And perfluoroalkylsulfonic acid 19.2%.
1 g of the obtained ceric oxide powder was added to 100 g of the thermoplastic fluororesin, kneaded at 330 ° C. for 10 minutes, and a film having a thickness of 50 μm was obtained by injection molding. The light transmittance of the obtained film at a wavelength of 320 nm was measured, and the coloring property was evaluated. Table 2 shows the results.

Example 2 Cerous carbonate (CeO ₂ 32.7)
%, Particle diameter 5-10 μm), 635 g of water was added to 1000 g, and the mixture was pulverized by a wet pulverizer to an average particle diameter of 1 μm. To this was added 375 g of hydrogen peroxide (H ₂ O ₂ 34.5%). After stirring this at room temperature for 1 hour, the solution was heated to 93 ° C., and the reaction was carried out while stirring for another 1 hour. Immediately thereafter, 345 g of zirconium oxychloride (ZrO ₂ 21.7%), followed by hydrochloric acid (HCl 35.4%) 1
96 g was added and heating was continued for another hour. After cooling, ultrafiltration (using an ultrafiltration membrane with a molecular weight cut off of 10,000)
After washing, 1,435 g of a stable sol solution was obtained. As a result of analyzing this, CeO _{2 was} 22.1% and ZrO _{2 was} 4.6%. This sol 1
After adding 121 g of water to 00 g and stirring well, 18 g of potassium perfluoroalkylsulfonate (C ₈ F ₁₇ SO ₃ K) was directly added and sufficiently stirred to obtain a slurry. This slurry was filtered and washed, and the obtained wet cake was allowed to stand and dried to obtain 44.1 g of ceric oxide of the present invention. When this was analyzed, it was CeO ₂ 47.6%, ZrO ₂ 9.9%, and perfluoroalkylsulfonic acid 34.4%. This was made into a fluororesin film having a thickness of 50 μm in the same manner as in Example 1. The light transmittance of the obtained film at a wavelength of 320 nm was measured, and the coloring property was evaluated. The results are also shown in Table 2.

(Example 3) Aqueous ceric sulfate solution (Ce
1028 g of aqueous ammonia (NH ₃ 4.0%) was added to 1000 g of O _{2 (} 8.0%) with stirring to form a gel. This was washed until no SO ₄ ^2- ions were observed. The obtained gel had a ceric oxide concentration of 22.5% CeO ₂ . 200g of this gel
3.9 g of glacial acetic acid and 69 water to give a CH ₃ COOH / CeO ₂ molar ratio of 0.25
6 g was added, and the mixture was placed in an autoclave and subjected to hydrothermal treatment at 200 ° C. for 24 hours to obtain an aqueous ceric oxide sol. The ceric oxide concentration of this sol was 5.0% CeO ₂ . To 100 g of this sol, 5 g of potassium perfluoroalkylsulfonate (C ₈ F ₁₇ SO ₃ K) was directly added, and sufficiently stirred to obtain a slurry. The slurry was filtered and washed, and the obtained wet cake was allowed to stand and dried to obtain 8.7 g of ceric oxide of the present invention. When this was analyzed, it was 51.0% of CeO _{2 and} 44.4% of perfluoroalkylsulfonic acid. Also,
When the specific surface area was measured, it was 62 m ² / g. This was made into a fluororesin film having a thickness of 50 μm in the same manner as in Example 1. The light transmittance of the obtained film at a wavelength of 320 nm was measured, and the coloring property was evaluated. The results are also shown in Table 2.

Example 4 12.5 g of potassium perfluoroalkylsulfonate was directly added to 1000 g of the ceric oxide slurry obtained in Example 1 and stirred. After the reaction,
The product was filtered and washed, and water was added to the obtained wet cake to 400 g. After stirring, this was spray-dried. Thus, 117 g of ceric oxide surface-treated with the fluorine-based surfactant of the present invention was obtained. When this was analyzed, CeO ₂ 87.5
% And perfluoroalkylsulfonic acid 8.1%.
In the same manner as in Example 1, a fluororesin film having a thickness of 50 μm was obtained. The light transmittance of the obtained film at a wavelength of 320 nm was measured, and the coloring property was evaluated. Table 2 also shows the results.

(Example 5) The ceric oxide of the present invention obtained in Example 3 was blended in a PVC film resin composition for agricultural use at a ratio shown in Table 1, and this was kneaded in a roll, followed by press molding. As a result, a sheet having a thickness of 2 mm was obtained.

[0028]

[Table 1]

The light transmittance of the obtained sheet at a wavelength of 320 nm was measured, and the coloring property was evaluated. Table 2 shows the results.

Example 6 ₄ g of ammonium perfluoroalkylcarboxylate (CF ₃ (CF ₂ ) ₆ CO ₂ NH ₄ ) was directly added to 100 g of the aqueous ceric oxide sol obtained in Example 3, and the mixture was sufficiently stirred. Thus, a slurry was obtained. This slurry was filtered and washed, and the obtained wet cake was allowed to stand and dried to obtain 7.9 g of ceric oxide of the present invention. When this was analyzed, CeO ₂ 53.7%, perfluoroalkyl carboxylic acid 4
It was 1.2%. This was blended with the agricultural PVC film resin composition of Example 5 at the same ratio, roll-kneaded, and then press-molded to obtain a sheet-shaped resin composition having a thickness of 2 mm. The light transmittance of the obtained sheet at a wavelength of 320 nm was measured, and the coloring property was evaluated. Table 2 also shows the results.

(Example 7) 1 g of the ceric oxide of the present invention obtained in Example 3 was added to a methacrylic resin Acrypet V
The mixture was mixed with H.sub.100g, heated and kneaded at 240.degree. C., and formed into a plate having a thickness of 2 mm by injection molding. The light transmittance of the obtained plate at a wavelength of 320 nm was measured to evaluate the coloring property. Table 2 also shows the results.

Example 8 To 100 g of the aqueous ceric oxide sol obtained in Example 3 was directly added 3 g of potassium perfluoroalkylsulfonate (C ₄ F ₉ SO ₃ K), and the mixture was sufficiently stirred to obtain a slurry. Was. The slurry was filtered and washed, and the obtained wet cake was allowed to stand and dried to obtain 6.9 g of ceric oxide of the present invention. When this was analyzed, it was 66.0% of CeO _{2 and} 28.8% of perfluoroalkylsulfonic acid.

(Comparative Example 1) 100 g of the aqueous ceric oxide sol obtained in Example 3 was diluted to 500 g with water, and 5 g of sodium anion surfactant sodium dodecylbenzenesulfonate was added to obtain a slurry. . Filter this slurry,
After washing, it was left to dry, yielding ceric oxide surface-treated with a surfactant. This dried product is CeO ₂ 65
% And dodecylbenzenesulfonic acid 35%. As in Example 1, a fluororesin film having a thickness of 50 μm was obtained.
The light transmittance of the obtained film at a wavelength of 320 nm was measured, and the coloring property was evaluated. The results are also shown in Table 2.

[0034]

[Table 2]

[0033]

According to the present invention, ceric oxide surface-treated with a fluorine-containing surfactant having a perfluorocarbon chain prevents deterioration of the resin due to oxidation when mixed with, for example, plastics and provides transparency. I do. Accordingly, the present invention has made it possible to use inorganic ultraviolet absorbers in applications where it has been difficult to apply them, and to list the application examples of the present invention, an ultraviolet cut film or a plastic plate can be used. , UV absorption of fluorescent lamps, etc., weather resistance of various paints and various functional coatings, UV absorption of cosmetics, weather resistance of fibers, weather resistance of transparent adhesive, weather of sealant And a resin refractive index adjuster.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C01F 17/00 A61K 7/40 B01J 13/00 C09C 3/10 C09K 3/00 104 CA (STN)

Claims (4)

(57) [Claims] Cerium oxide surface-treated with a fluorine-containing surfactant having a perfluorocarbon chain. 2. The ceric oxide of claim 1, wherein the fluorinated surfactant having a perfluorocarbon chain is a perfluoroalkyl sulfonate. 3. The amount of the fluorinated surfactant having a perfluorocarbon chain is based on the amount of CeO ₂ of ceric oxide.
3. The ceric oxide of claim 1 or 2 which is 12 to 100% by weight. 4. A fluorinated surfactant having a perfluorocarbon chain is added to the ceric oxide sol, mixed and then dried, and the surface is treated with a fluorinated surfactant having a perfluorocarbon chain. Of producing ceric oxide.