JP5167595B2 - Transparent plastic member and composite plastic member containing zirconia fine particles - Google Patents

Description

  The present invention relates to a transparent plastic member and a composite plastic member containing zirconia fine particles. More specifically, by combining zirconia fine particles and various plastic members, both high refractive index and high transparency are realized, and at the same time, mechanical properties. It is related with the transparent plastic member and composite plastic member containing a zirconia microparticle which can aim at improvement.

  Conventionally, attempts have been made to improve the mechanical properties and the like of a resin by combining it with a resin using an inorganic oxide such as silica as a filler. As a method of combining the filler and the resin, a method of mixing a dispersion in which an inorganic oxide is dispersed in water and / or an organic solvent and a resin is generally used. By mixing by the method, an inorganic oxide particle composite plastic in which inorganic oxide particles are combined can be produced.

On the other hand, in the flat panel display (FPD) field such as a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (EL), and a surface electric field display (SED), in recent years, the glass substrate has been replaced. Many attempts have been made to use various plastic materials. By using a plastic material, it is possible to improve the ease of cracking, workability, weight, etc., which are problems in a glass substrate.
In addition, functional films using various plastic films such as anti-reflection (AR) film, anti-glare (AG) film, and hard coat (HC) film are affixed to the surface of this flat panel display to improve visibility. It helps to prevent scratches on the surface. Important properties required for such a plastic film include transparency, refractive index, mechanical properties, and the like. In particular, in order to improve the refractive index, a composite plastic film in which a plastic film and an inorganic oxide filler having a high refractive index per se, such as zirconia (ZrO ₂ ) and titania (TiO ₂ ), are combined. Is used.

As a method of compounding such an inorganic oxide filler and a plastic, the following two methods can be roughly classified.
(1) A method of kneading an inorganic oxide filler into plastic.
This method includes (a) a method in which an inorganic oxide filler is dispersed in a resin monomer, and this resin monomer is polymerized or polycondensed to form an inorganic oxide filler-containing plastic film, and (b) a liquid resin material is inorganic. There is a method in which an oxide filler is dispersed, then formed into a film, and then a resin material is cured to form an inorganic oxide filler-containing plastic film.
Examples of the inorganic oxide filler-containing plastic film include a zirconia particle-containing polyester film having improved surface wear resistance by dispersing zirconia particles having a particle diameter of 0.005 to 0.3 μm in polyester. Has been proposed (see, for example, Patent Document 1).

(2) A method of forming a film containing an inorganic oxide filler on a plastic film.
In this method, a paint containing an inorganic oxide filler and a binder component is applied onto a plastic film, and then the binder component is cured to form a film. As the binder component, silica prepared by a sol-gel method is used. Inorganic materials such as polyester, and resin materials such as polyester and polyether are used.
As an example of this film, a zirconia particle composite plastic film having a high refractive index and high transparency of several microns in thickness has been proposed by combining zirconia particles having a particle diameter of 10 to 100 nm and plastic (for example, , See Patent Document 2).
Japanese Patent Laid-Open No. 05-171012 Japanese Patent Laying-Open No. 2005-161111

By the way, in the conventional method of kneading the inorganic oxide filler into the plastic, since the zirconia particles of 0.005 μm to 0.3 μm are compounded only by physical treatment, the thickness of the plastic film is several tens μm or more. In this case, in order to ensure a high refractive index of the plastic film, it is necessary to contain an inorganic oxide filler in an amount sufficient to cause the high refractive index. However, when the content of the inorganic oxide filler is increased, there is a problem that it becomes difficult to ensure the transparency of the plastic film. On the other hand, in order to ensure the transparency of the plastic film, the content of the inorganic oxide filler has to be reduced, which makes it difficult to improve the refractive index.
Thus, when an inorganic oxide filler is contained in a plastic film, there is a trade-off relationship between high refractive index and transparency, and it is difficult to satisfy both high refractive index and transparency. there were.

  On the other hand, in the method of forming a film containing an inorganic oxide filler on a plastic film, it is possible to form a high refractive index film on the surface of the plastic film, but this high refractive index film is integrated with the substrate. Therefore, it is difficult to completely follow the folding of the plastic film. Therefore, after forming a high refractive index film on the surface of the plastic film, if the plastic film is bent, there is a risk that the high refractive index film may crack or the high refractive index film may be peeled off. There was a problem.

  The present invention has been made in order to solve the above-described problems, and has a zirconia fine particle-containing transparent plastic member capable of achieving both high refractive index and high transparency and at the same time improving mechanical properties. An object is to provide a composite plastic member.

  As a result of intensive studies to solve the above problems, the present inventors modified the surface of zirconia fine particles having a dispersed particle diameter of 1 nm or more and 20 nm or less with a surface modifier, and the surface-modified zirconia fine particles Dispersion and high filling rate of zirconia fine particles in plastic can be realized by uniformly dispersing in transparent plastic in the form of film or sheet. As a result, high refraction is ensured while ensuring high transparency. It has been found that it is possible to increase the efficiency, and at the same time, it is possible to improve the mechanical characteristics, and the present invention has been completed.

That is, the transparent plastic member containing zirconia fine particles of the present invention is a film-like or sheet-like transparent plastic member having a thickness of 10 μm to 5 mm , the surface is modified with a surface modifier, and the dispersed particle diameter is 1 nm or more. It is characterized in that zirconia fine particles of 20 nm or less are dispersed in a transparent plastic .

The content of the zirconia fine particles is preferably 10% by weight or more and 80% by weight or less.
The transparent plastic member containing zirconia fine particles preferably has a visible light transmittance of 80% or more when the thickness is 30 μm or more and 300 μm or less.

The surface modifier is preferably one or more selected from the group consisting of alkoxysilane, chlorosilane, alkylalkoxysilane, alkylchlorosilane, siloxane, and surfactant.
The alkoxysilane or chlorosilane is preferably a silane coupling agent.
The siloxane is preferably a modified silicone or a silicone resin.

  The composite plastic member of the present invention includes the transparent plastic member containing zirconia fine particles of the present invention.

According to the transparent plastic member containing zirconia fine particles of the present invention, the transparent plastic member is a film or sheet having a thickness of 10 μm to 5 mm , the surface is modified with a surface modifier, and the dispersed particle diameter is 1 nm or more. Since zirconia fine particles of 20 nm or less are dispersed in a transparent plastic, the refractive index can be increased while maintaining the transparency of the plastic member, and the mechanical properties can be improved.
Therefore, it is possible to provide a plastic member having a high refractive index, high transparency, and improved mechanical properties.

  According to the composite plastic member of the present invention, since the transparent plastic member containing zirconia fine particles of the present invention is provided, the refractive index can be increased while maintaining the transparency of the composite plastic member, and the mechanical properties are improved. Can be made.

The best mode for carrying out the zirconia fine particle-containing transparent plastic member and composite plastic member of the present invention will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

"Transparent plastic material containing zirconia fine particles"
The transparent plastic member containing zirconia fine particles according to the present invention is a transparent plastic member in the form of a film or a sheet, and the surface thereof is modified by a surface modifier and contains zirconia fine particles having a dispersed particle diameter of 1 nm or more and 20 nm or less. It is a transparent plastic member.
This transparent plastic member is a film or sheet having a thickness of 10 μm to 5 mm. Specifically, there are various thicknesses and shapes such as a transparent plastic film, a transparent plastic sheet, and a thin transparent plastic substrate. It is possible to select appropriately according to the application.
The zirconia fine particles are preferably uniformly dispersed in a plastic having transparency to visible light.

The dispersed particle diameter of the zirconia fine particles is preferably 1 nm or more and 20 nm or less.
Here, the reason why the dispersed particle diameter of the zirconia particles is limited to 1 nm or more and 20 nm or less is that when the dispersed particle diameter is less than 1 nm, the crystallinity becomes poor and it is difficult to express particle characteristics such as refractive index. On the other hand, if the dispersed particle diameter exceeds 20 nm, the transparency of the plastic member is lowered.
Thus, since the zirconia particles are nano-sized particles, even when the zirconia particles are dispersed in the plastic member, light scattering is small and transparency can be maintained.

The zirconia fine particles are obtained by modifying the surface with a surface modifier. As the surface modifier, the hydrophilic zirconia particles can be hydrophobized and the dispersibility can be ensured with respect to the composite plastic. As long as it is a thing, it does not need to specifically limit, For example, 1 type, or 2 or more types selected from the group of alkoxysilane, chlorosilane, alkyl alkoxysilane, alkylchlorosilane, siloxane, and surfactant is preferable.
Of these, more preferable are silane compounds such as alkoxysilane, chlorosilane, alkylalkoxysilane, alkylchlorosilane, and siloxane which are excellent in heat resistance.

Alkoxysilane, chlorosilane, alkylalkoxysilane, and alkylchlorosilane are compounds represented by the structural formula SiX _m Y _4-m , and each of the X group and the Y group includes one or more of those shown below. Those are preferred.
X group includes vinyl group, allyl group, 3-glycidoxypropyl group, 2- (3,4 epoxycyclohexyl) ethyl group, 3-acryloxypropyl group, 3-methacryloxypropyl group, styryl group, 3- Aminopropyl group, N-2 (aminoethyl) 3-aminopropyl group, N-phenyl-3-aminopropyl group, 3-mercaptopropyl group, 3-isocyanatopropyl group, alkyl group represented by C _n H _{2n + 1} Among them, those in which n is in the range of 1 to 20, phenyl groups and the like are mentioned.
Examples of the Y group include chlorine, a hydroxy group, an alkoxy group represented by C _n H _{2n + 1} O, wherein n is in the range of 1 to 20, an acetoxy group, and the like.

  As the alkoxysilane or chlorosilane, a silane coupling agent is particularly preferable. For example, vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane. , 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane and the like.

  Examples of the alkylchlorosilane include methyltrichlorosilane, ethyltrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane, diethyldichlorosilane, trimethylchlorosilane, and triethylchlorosilane.

Siloxane is preferably a modified silicone or a silicone resin. The modified silicone is an epoxy-modified silicone, an epoxy / polyether-modified silicone, an alcohol-modified silicone, a methacryl-modified silicone, a methacrylate-modified silicone, a phenol-modified silicone, a methylstyryl-modified silicone, an acrylic. Examples include modified silicone, mercapto-modified silicone, amino-modified silicone, and methyl hydrogen silicone.
Examples of the silicone resin include methyl silicone resin, methylphenyl silicone resin, diphenyl silicone resin, and the like.

As the surfactant, an anionic surfactant, a cationic surfactant, an ionic surfactant such as an amphoteric surfactant, or a nonionic surfactant is preferably used.
Examples of the anionic surfactant include fatty acid sodium such as sodium oleate, sodium stearate and sodium laurate, fatty acid such as fatty acid potassium and sodium fatty acid ester sulfonate, and phosphoric acid such as sodium alkyl phosphate ester. And olefins such as sodium alpha olein sulfonate, alcohols such as sodium alkyl sulfate, and alkylbenzenes.
Examples of the cationic surfactant include alkyl methyl ammonium chloride, alkyl dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, and alkyl dimethyl benzyl ammonium chloride.

Examples of the zwitterionic surfactant include carboxylic acid systems such as alkylaminocarboxylates and phosphate ester systems such as phosphobetaine.
Examples of the nonionic surfactant include fatty acid-based compounds such as polyoxyethylene lanolin fatty acid ester and polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, and fatty acid alkanolamide.

Examples of a method for modifying the surface of the zirconia fine particles using the surface modifier include a wet method and a dry method.
The wet method is a method of modifying the surface of the zirconia fine particles by introducing a surface modifier and zirconia fine particles into a solvent and mixing them.
The dry method is a method of modifying the surface of the zirconia fine particles by introducing the surface modifier and the dried zirconia fine particles into a dry mixer such as a mixer and mixing them.

The weight ratio of the modified portion of the surface-modified zirconia fine particles is preferably 5% by weight or more and 200% by weight or less of the total amount of the zirconia fine particles, more preferably 10% by weight or more and 100% by weight or less, Preferably they are 20 weight% or more and 100 weight% or less.
Here, the reason why the weight ratio of the modified part of the zirconia fine particles is limited to 5% by weight or more and 200% by weight or less is that if the weight ratio of the modified part is less than 5% by weight, the compatibility of the zirconia fine particles with the resin is reduced. This is because the transparency is lost when the resin is combined with the resin. On the other hand, if the weight ratio of the modified part exceeds 200% by weight, the effect of the surface treatment agent on the resin characteristics increases, and the refractive index. This is because the composite properties such as the above deteriorate.

  The plastic may be any film or sheet having transparency with respect to visible light and having a thickness of 10 μm to 5 mm, and there are various types of plastics such as a film, a sheet, and a very thin thin plate. A shape can be selected and used.

Examples of such plastics include polyethylene terephthalate (PET), polycarbonate (PC), polyethersulfone (PES), polyethylene naphthalate (PEN), polyarylate (PAR), aromatic polyether ketone (PEEK), and polyolefin. , Triacetyl cellulose (TAC), acrylonitrile / styrene copolymer (AS resin), methyl methacrylate / styrene copolymer (MS resin), poly-4-methylpentene (TPX), and the like.
In addition to these, a polyester resin, a polyimide resin, an epoxy resin, a norbornene-based polymer and the like having transparency to visible light can also be used.

In the zirconia fine particle-containing transparent plastic member, the content of the zirconia fine particles is preferably 10% by weight or more and 80% by weight or less, more preferably 20% by weight or more and 80% by weight or less.
Here, the reason why the content of the zirconia fine particles is limited to 10% by weight or more and 80% by weight or less is that the lower limit of 10% by weight is the minimum value of the content that effectively improves the refractive index of the plastic member. This is because if the content is less than% by weight, the refractive index of the plastic member cannot be increased. On the other hand, the upper limit of 80% by weight is the maximum value of the content ratio that can maintain the characteristics of the plastic member itself, and if it exceeds 80% by weight, the characteristics as the plastic member may be lost.

In this zirconia fine particle-containing transparent plastic member, when the content of zirconia fine particles is 25% by weight, the visible light transmittance is preferably 80% or more, more preferably 82% or more when the optical path length is 100 μm.
This visible light transmittance varies depending on the content of zirconia fine particles in the transparent plastic member, and is 85% or more when the content of zirconia fine particles is 10% by weight, and is 80% or more when the content of zirconia fine particles is 40% by weight.

The refractive index of the zirconia fine particles is a value larger than 2 although there is a slight difference depending on the crystal system. Therefore, the refractive index can be improved by dispersing the zirconia fine particles in the plastic.
In addition, since the zirconia fine particles are nano-sized particles, even when they are combined with plastic, light scattering is small and the transparency of the plastic member can be maintained.

"Method for producing transparent plastic member containing zirconia fine particles"
When manufacturing thin products such as transparent plastic films and transparent plastic sheets, zirconia fine particles whose surface is modified by a surface modifier and whose dispersed particle diameter is 1 nm or more and 20 nm or less are uniformly applied to the raw material of the plastic to be combined. It can be obtained by dispersing to form a mixture, polymerizing or condensation polymerizing the mixture to obtain a zirconia fine particle-containing plastic composition, and molding the plastic composition into a film or sheet.

  Also, zirconia fine particles whose surface is modified by a surface modifier and whose dispersed particle diameter is 1 nm or more and 20 nm or less are dispersed in an organic solvent to obtain a dispersion containing zirconia fine particles, and the raw material of the plastic to be combined is dissolved in this dispersion Then, a plastic solution containing zirconia fine particles can be obtained, and the plastic solution can be obtained by forming the plastic solution into a film or sheet by a solution casting method.

"Composite plastic parts"
Various functional films such as an antireflection (AR) film, an antiglare (AG) film, and a hard coat (HC) film are formed on the surface of the transparent plastic member containing zirconia fine particles, or antireflection (AR). Composites with various functions such as anti-reflection (AR) function, anti-glare (AG) function, and anti-scratch function by bonding various plastic films such as film, anti-glare (AG) film, and hard coat (HC) film. A plastic member can be obtained.
Examples of the composite plastic member include a functional film and a functional sheet.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited by these Examples.
"Example 1"
(Preparation of zirconia fine particles)
To a zirconium salt solution in which 2615 g of zirconium oxychloride octahydrate was dissolved in 40 L (liter) of pure water, dilute ammonia water in which 344 g of 28% ammonia water was dissolved in 20 L of pure water was added with stirring, and the zirconia precursor slurry was added. It was adjusted.
Next, an aqueous sodium sulfate solution in which 300 g of sodium sulfate was dissolved in 5 L of pure water was added to this slurry with stirring. The amount of sodium sulfate added at this time was 30% by weight with respect to the zirconia converted value of zirconium ions in the zirconium salt solution.

Next, this mixture was dried in the air at 130 ° C. for 24 hours using a dryer to obtain a solid.
Next, this solid material was pulverized with an automatic mortar and then baked in the air at 500 ° C. for 1 hour using an electric furnace.
Next, the fired product is put into pure water, stirred to form a slurry, washed using a centrifuge, and after sufficiently removing the added sodium sulfate, dried in a dryer, Zirconia fine particles were prepared.
When the crystal system of the zirconia fine particles was examined using an X-ray diffractometer, it was confirmed from the powder X-ray diffraction pattern (chart) that the crystal system of the zirconia fine particles was a tetragonal system as shown in FIG. It was done.

(Preparation of polyethylene terephthalate film containing zirconia fine particles)
Next, to 45 g of the zirconia fine particles, 50 g of ethylene glycol as a dispersion medium and 5 g of dimethyldichlorosilane (manufactured by Shin-Etsu Chemical Co., Ltd.) as a surface modifier are added and mixed, and then a dispersion treatment is performed to obtain a zirconia transparent dispersion. Produced.
The dispersed particle size of the zirconia fine particles in this transparent zirconia dispersion was measured using a dynamic light scattering particle size distribution analyzer (manufactured by Malvern) and found to be 10 nm.

Next, 50 parts by weight of dimethyl terephthalate was added to 100 parts by weight of this dispersion, and 0.05 parts by weight of magnesium acetate was further added as a catalyst to conduct a transesterification reaction. Further, 0.02 part by weight of antimony oxide as a polycondensation catalyst and 0.02 part by weight of trimethyl phosphate as a heat stabilizer were added to carry out a polycondensation reaction to prepare a polyethylene terephthalate composition containing zirconia fine particles.
Next, this polyethylene terephthalate composition was melt-extruded at 290 ° C., then stretched three times in length and breadth at 90 ° C., and then heat treated at 220 ° C. for 15 seconds, and biaxially stretched with a thickness of 100 μm. A polyethylene terephthalate film containing zirconia fine particles was prepared.

"Example 2"
Particle synthesis was performed according to Example 1 to produce zirconia fine particles.
Next, 80 g of methylene chloride as a dispersion medium and 5 g of phenyltrichlorosilane (manufactured by Shin-Etsu Chemical Co., Ltd.) as a surface modifier are added to 15 g of the zirconia fine particles, and the mixture is stirred for 30 minutes at 7000 rpm using a homogenizer. A zirconia dispersion was prepared.
When the dispersed particle diameter of the zirconia fine particles in this zirconia transparent dispersion was measured using a dynamic light scattering particle size distribution analyzer (manufactured by Malvern), it was 8 nm.

Next, 30 parts by weight of polycarbonate resin pellet Panlite C-1400QJ (manufactured by Teijin Kasei Co., Ltd.) was added to 100 parts by weight of this dispersion and stirred to prepare a polycarbonate resin solution in which zirconia fine particles were dispersed.
Next, the polycarbonate resin solution is filtered to remove foreign matters, and then cast onto a mirror-finished stainless steel belt using a lip die, dried for 30 minutes using hot air at 60 ° C., then peeled off, and the thickness is 100 μm. A polycarbonate film containing zirconia fine particles was prepared.

"Example 3"
A zirconia dispersion was prepared according to Example 2.
Next, 30 parts by weight of polyethersulfone resin powder Sumika Excel 5200G (manufactured by Sumitomo Chemical Co., Ltd.) was added to 100 parts by weight of this zirconia dispersion and stirred to prepare a polyethersulfone resin solution in which zirconia particles were dispersed. Next, this polyethersulfone resin solution is filtered to remove foreign matter, and then cast onto a mirror-finished stainless steel belt using a lip die, dried for 30 minutes using hot air at 60 ° C., and then peeled off. A 100 μm zirconia-containing polyethersulfone resin film was prepared.

“Comparative Example 1”
A dispersion treatment was performed according to Example 1 except that RC-100 (manufactured by Daiichi Rare Element Co., Ltd.) was used as the zirconia particles to produce a zirconia dispersion. It was 100 nm when the dispersed particle diameter of the zirconia particle of this dispersion liquid was measured.
Next, using this dispersion, a biaxially stretched zirconia particle-containing polyethylene terephthalate film having a thickness of 100 μm was produced according to Example 1.

“Comparative Example 2”
A zirconia dispersion was prepared by carrying out a dispersion treatment according to Example 2 except that RC-100 (manufactured by Daiichi Rare Element Co., Ltd.) was used as the zirconia particles. It was 100 nm when the dispersed particle diameter of the zirconia particle of this dispersion liquid was measured.
Next, using this dispersion, a zirconia particle-containing polycarbonate film having a thickness of 100 μm was produced according to Example 2.

“Comparative Example 3”
A zirconia dispersion was prepared by carrying out a dispersion treatment according to Example 3 except that RC-100 (manufactured by Daiichi Rare Element Co., Ltd.) was used as the zirconia particles. It was 100 nm when the dispersed particle diameter of the zirconia particle of this dispersion liquid was measured.
Subsequently, using this dispersion, a zirconia particle-containing polyethersulfone resin film having a thickness of 100 μm was produced according to Example 3.

“Comparative Example 4”
To 10 parts by weight of the zirconia dispersion of Comparative Example 1, 90 parts by weight of ethylene glycol was added and stirred. To this, 50 parts by weight of dimethyl terephthalate was added, and 0.05 parts by weight of magnesium acetate was further added as a catalyst to conduct a transesterification reaction. went. Furthermore, 0.02 parts by weight of antimony oxide as a polycondensation catalyst and 0.02 parts by weight of trimethyl phosphate as a heat stabilizer were added to carry out a polycondensation reaction, thereby preparing a zirconia particle-containing polyethylene terephthalate composition.
Next, using this polyethylene terephthalate composition, a zirconia particle-containing polyethylene terephthalate film having a thickness of 100 μm was produced according to Example 1.

“Comparative Example 5”
By adding 120 parts by weight of methylene chloride to 10 parts by weight of the zirconia dispersion of Comparative Example 2, and further adding 28 parts by weight of polycarbonate resin pellets Panlite C-1400QJ (manufactured by Teijin Chemicals Ltd.), the zirconia particles are stirred. A polycarbonate resin solution was prepared.
Subsequently, using this polycarbonate resin solution, a zirconia particle-containing polyethersulfone resin film having a thickness of 100 μm was produced according to Example 2.

“Comparative Example 6”
120 parts by weight of methylene chloride was added to 10 parts by weight of the zirconia dispersion of Comparative Example 3, and 28 parts by weight of the polyethersulfone resin powder was dissolved therein to prepare a polyethersulfone resin solution containing zirconia particles.
Next, a polyethersulfone resin film containing zirconia particles having a thickness of 100 μm was prepared according to Example 3 using the polyethersulfone resin solution.

"Evaluation of film"
About each film of Examples 1-3 and Comparative Examples 1-6, three points of visible light transmittance, haze, and refractive index were evaluated with the following apparatus or method.
(1) Visible light transmittance Using a spectrophotometer V-570 (manufactured by JASCO Corp.), the visible light transmittance in the wavelength range of 350 nm to 800 nm was measured for air as 100%.

(2) Haze Japanese Industrial Standards: Measured in accordance with JIS K 7136 "Plastics-Determination of haze of transparent material" using a haze meter NDH-2000 (manufactured by Nippon Denshoku) with 0% air. .
(3) Refractive index Measured with an Abbe refractometer in accordance with Japanese Industrial Standards: JIS K 7142 “Plastic Refractive Index Measuring Method”.
Here, on the basis of a film to which zirconia is not added, a case where the refractive index is improved by 0.05 or more is indicated by “◯”, and a case where the refractive index is improved by less than 0.05 is indicated by “X”.
The above evaluation results are shown in Table 1.

According to these evaluation results, in Examples 1 to 3, it was found that the visible light transmittance, haze, and refractive index were all good.
On the other hand, in Comparative Examples 1-6, any one of visible light transmittance, haze, and refractive index was inferior to Examples 1-3.

  The transparent plastic member containing zirconia fine particles of the present invention has a surface modified with a surface modifier, and zirconia fine particles having a dispersed particle diameter of 1 nm or more and 20 nm or less are dispersed in a film-like or sheet-like plastic. In addition to improving the refractive index and transparency of a plastic member in the form of a sheet or a sheet and improving the mechanical properties, liquid crystal displays (LCD), plasma displays (PDP), including composite plastic members, In addition to display substrates or functional films for flat panel displays (FPD) such as electroluminescence displays (EL) and surface electric field displays (SED), microarray lens sheets, prism sheets, Fresnel lenses, and optical films in the optical field. Lens sheet, such as Ji Molecular lens, a light guide plate, a diffusion film, a holographic substrate, even in the light control film and the like, the effect is large.

It is a figure which shows the powder X-ray-diffraction figure of the zirconia microparticles | fine-particles of Example 1 of this invention.

Claims (7)

A film or sheet transparent plastic member having a thickness of 10 μm to 5 mm ,
A transparent plastic member containing zirconia fine particles, wherein the surface is modified with a surface modifier and zirconia fine particles having a dispersed particle diameter of 1 nm or more and 20 nm or less are dispersed in a transparent plastic.   2. The zirconia fine particle-containing transparent plastic member according to claim 1, wherein the content of the zirconia fine particles is 10 wt% or more and 80 wt% or less.   The transparent plastic member containing zirconia fine particles according to claim 2, wherein the visible light transmittance is 80% or more when the thickness is 30 µm or more and 300 µm or less.   The said surface modifier is 1 type, or 2 or more types selected from the group of alkoxysilane, chlorosilane, alkyl alkoxysilane, alkylchlorosilane, siloxane, and surfactant, The Claim 1, 2, or 3 characterized by the above-mentioned. Transparent plastic member containing fine zirconia particles.   5. The transparent plastic member containing zirconia fine particles according to claim 4, wherein the alkoxysilane or chlorosilane is a silane coupling agent.   5. The transparent plastic member containing zirconia fine particles according to claim 4, wherein the siloxane is a modified silicone or a silicone resin.   A composite plastic member comprising the transparent plastic member containing zirconia fine particles according to any one of claims 1 to 6.

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