JP6132301B2 - Zirconia particles and zirconia-containing epoxy resin composition - Google Patents

Description

  The present invention relates to zirconia particles and a zirconia-containing resin composition. More specifically, by using the zirconia-containing resin composition of the present invention, the present invention has excellent transparency and a high refractive index, and an LED (light emission). The present invention relates to a cured product useful as a material for realizing improvement in light extraction efficiency of a diode) or organic EL (organic electroluminescence).

In the optical semiconductor sealing material, epoxy resin or silicone resin is widely used.
However, the problem with epoxy resins and silicone resins is their low refractive index. In the optical semiconductor sealing material, since the improvement of the light extraction efficiency is required, it is necessary to increase the refractive index of the resin.

Thus, as means for improving the refractive index of the resin, Patent Document 1 achieves an improvement in the refractive index by introducing an aromatic substituent into the silicone resin. According to this, by introducing a phenyl group having a high refractive index as a silicon substituent, it is possible to improve the refractive index from 1.4 to slightly higher than 1.5.
In addition, a method for adjusting the refractive index of a resin by dispersing a metal oxide having a high refractive index such as titania, zirconia, or barium titanate in the resin has been studied.
However, it is difficult to disperse the metal oxide particles that are hydrophilic in a hydrophobic and water-repellent silicone resin, and it is difficult to apply to applications that require transparency.
Therefore, in Patent Document 2, in order to disperse titania particles in a silicone resin, a metal oxide fine particle dispersant obtained by copolymerizing an acrylic part having affinity for particles and a silicone part having affinity for silicone resin is provided. It is disclosed. Patent Document 3 reports a method of dispersing titania using silicon acid or the like that is structurally similar to silicone.

  On the other hand, particles prepared by a sol-gel method or the like generally have an advantage that the primary particle size can be adjusted from several nm to several tens of nm, and the monodispersity is excellent. In the sol-gel method, since the reaction is usually performed in a water-alcohol system, when the obtained particles are dispersed in a resin, it is necessary to replace the dispersion solvent of the obtained particles with a solvent for dissolving the resin. However, simply replacing the solvent often causes the particles to aggregate because the affinity between the surface of the fine particles and the solvent is low. Therefore, Patent Document 4 discloses a method of performing solvent replacement after treating particles prepared by a sol-gel method with various surface treatment agents.

However, in the method of Patent Document 1, if the amount of phenyl group introduced is increased, the resin becomes hard and brittle, so that the utilization method is limited, and in addition, the silicone resin is crystallized, resulting in a decrease in transparency. There's a problem.
Further, in the method of Patent Document 2, an excessive dispersant that has not been used for the surface modification of particles causes a decrease in the permeability of the organic polymer that is the base material of the nanocomposite and a suppression of the increase in the refractive index of the nanocomposite. Since it becomes a factor, it has the subject that it is not enough at the point of the transmittance | permeability and refractive index of the manufactured nanocomposite.
Furthermore, the method of Patent Document 3 has a problem in dispersion stability in addition to dispersibility.
Furthermore, when the metal oxide treated with the surface treatment agent according to Patent Document 4 is dispersed in the resin, the silane coupling agent must have an unsaturated hydrocarbon group that can be polymerized with the resin. If not, the resin composition may become clouded by phase separation, and the hardness and scratch resistance will not be obtained.

JP 2005-76003 A JP 2006-131547 A JP-A-9-208438 JP 2001-164117 A

  An object of the present invention is to provide a zirconia-containing resin that is excellent in transparency and has a high refractive index, which can be used as a material that contributes to improving the light extraction efficiency of an LED (light emitting diode) or organic EL (organic electroluminescence). It is to provide a composition.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that zirconia particles 1 to 20 nm having a volume average particle diameter of 1 to 20 nm that are surface-modified with hydroxycarboxylic acid with respect to 100 parts by weight of an epoxy resin or a silicone resin. It has been found that by containing 400 parts by weight, a resin composition having a high refractive index and transparency can be obtained, and the present invention has been completed.
That is, the present invention relates to surface-modified zirconia particles characterized in that zirconia particles having a volume average particle diameter of 1 to 20 nm are modified with hydroxycarboxylic acid.
The present invention also includes a zirconia-containing resin characterized by containing 1 to 400 parts by weight of zirconia particles having a surface-modified volume average particle diameter of 1 to 20 nm with respect to 100 parts by weight of an epoxy resin or a silicone resin. The present invention relates to a composition and a cured product thereof.

  The cured product using the zirconia-containing resin composition of the present invention is expected to improve the light extraction efficiency as compared with conventional resins when used as an LED or organic EL sealing resin as a high refractive index resin. it can.

Hereinafter, the present invention will be described in detail.
The surface-modified zirconia particles of the present invention are not particularly limited as long as zirconia particles having an average particle diameter of 1 to 20 nm are modified with hydroxycarboxylic acid.
Here, the volume average particle diameter is defined by the volume average particle diameter obtained from transmission electron microscope measurement.
The reason why the volume average particle diameter of the zirconia particles is 1 to 20 nm is that when the volume average particle diameter is less than 1 nm, the crystallinity becomes poor and it is difficult to express particle characteristics such as refractive index, while the volume average particle diameter This is because if the diameter exceeds 20 nm, the transparency decreases when a dispersion or a resin composite is used.

Since zirconia particles are nano-sized particles, light scattering is small even in a resin composite that is combined with a resin, and the transparency of the resin can be maintained.
As the zirconia particles, either monoclinic zirconia particles or tetragonal zirconia particles, or monoclinic zirconia particles and tetragonal zirconia particles are used, and tetragonal zirconia particles are preferable for the following reasons. .
The reason why tetragonal zirconia particles are preferable as the zirconia particles is that, from the standpoint of fine particle synthesis, when the particle size of the fine particles is as small as 20 nm or less, the tetragonal crystals are more stable than the conventionally known monoclinic crystals. In addition, the mechanical properties of the resin composite in which the hardness is high and the zirconia particles are dispersed in the resin can be improved, and in this resin composite, compared with the case where the monoclinic zirconia particles are added. This is because high toughness is exhibited by volume expansion called martensitic transformation.

  As a method of producing such zirconia particles having a volume average particle diameter of 1 to 20 nm, for example, a dilute aqueous ammonia is added to a zirconium salt solution obtained by dissolving zirconium oxychloride octahydrate in pure water while stirring. A zirconia precursor slurry is prepared, and then an aqueous solution of an inorganic salt such as sodium sulfate is added to the slurry while stirring to form a slurry, which is then washed using a centrifuge, and the added inorganic salt is sufficiently removed. And then pulverizing with a wet mixer such as a bead mill using zirconia beads of 0.05 to 1 mmφ to prepare zirconia particles.

  The surface modifier for zirconia particles in the present invention is hydroxycarboxylic acid, and the hydroxycarboxylic acid is used to facilitate incorporation of zirconia particles into the resin during curing, and is combined with zirconia particles. There is no particular limitation on the epoxy resin or the like as long as the dispersibility of the zirconia particles can be secured after curing.

  Examples of the hydroxycarboxylic acid include glycolic acid, lactic acid, tartronic acid, glyceric acid, hydroxybutyric acid, malic acid, tartaric acid, citramalic acid, citric acid, isocitric acid, leucine acid, mevalonic acid, pantoic acid, ricinoleic acid, Ricinelaidic acid, cerebronic acid, quinic acid, shikimic acid, hydroxybenzoic acid, creosote acid, vanillic acid, syringic acid, pyrocatechuic acid, resorcylic acid, protocatechuic acid, gentisic acid, olceric acid, gallic acid, mandelic acid, benzylic acid, Examples include atrolactic acid, mellitic acid, furoletic acid, coumaric acid, umbelic acid, caffeic acid, ferulic acid, and sinapinic acid. Among them, hydroxybenzoic acid is preferred because of its excellent dispersibility in surface-modified zirconia resin. Has a hydroxyl group at the ortho or para position The use of hydroxybenzoic acid are more preferred that, hydroxybenzoic acid having a hydroxyl group at the ortho position are especially preferred.

  As a method for obtaining such a surface-modified zirconia, for example, a specific hydroxycarboxylic acid is added to an aqueous dispersion of zirconia particles and a mixture of methanol, and then water and methanol are removed by azeotropic distillation. By replacing the solvent with toluene, a toluene dispersion in which the surface-modified zirconia is dispersed can be produced. Thereafter, the solvent is distilled off to obtain a white powder of surface-modified zirconia.

  The content of hydroxycarboxylic acid in zirconia particles surface-modified with a specific hydroxycarboxylic acid (hereinafter sometimes referred to as surface-modified zirconia) is determined in view of the dispersibility in the resin composition and the effect of improving the refractive index. The amount is preferably 10 to 80 parts by weight and more preferably 25 to 45 parts by weight with respect to 100 parts by weight of the zirconia particles.

  The zirconia-containing resin composition of the present invention is not particularly limited as long as it contains 1 to 400 parts by weight of the surface-modified zirconia particles of the present invention with respect to 100 parts by weight of the epoxy resin or silicone resin.

  Examples of the epoxy resin include bifunctional glycidyl ether type epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, hydrogenated bisphenol A type epoxy resins, and biphenyl type epoxy resins; Polyfunctional glycidyl ether type epoxy resin such as novolac type epoxy resin, orthocresol novolak type epoxy resin, alkyl-modified triphenolmethane type epoxy resin, tris-hydroxyphenylmethane type epoxy resin, tetraphenylolethane type epoxy resin; Glycidyldiaminidiphenylmethane type epoxy resin, triglycidyl isocyanurate type epoxy resin, aminophenol type epoxy resin, aniline type epoxy resin, toluidine Glycidylamine type epoxy resins such as epoxy resins; 1,4-cyclohexanediol diglycidyl ether, bis (3,4-epoxycyclohexylmethyl) oxalate, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4 Epoxy-6-methylcyclohexylmethyl) adipate, vinylcyclohexylene diepoxide, limonene diepoxide, bis (3,4-epoxycyclohexylmethyl) pimelate, dicyclopentadiene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxy Cyclohexanecarboxylate, 3,4-epoxy-1-methylcyclohexyl-methyl-3,4-epoxy-1-methylcyclohexanecarboxylate, 6-methyl-3,4-epoxycyclohexyl Rumethylmethyl-6-methyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-2-methylcyclohexylmethyl-3,4-epoxy-2-methylcyclohexanecarboxylate, 3,4-epoxy-3-methylcyclohexyl Cyclic aliphatic epoxy resins such as methyl-3,4-epoxy-3-methylcyclohexanecarboxylate, 3,4-epoxy-5-methylcyclohexyl-methyl-3,4-epoxy-5-methylcyclohexanecarboxylate; Examples thereof include heterocyclic epoxy resins such as glycidyl isocyanurate and hydantoin epoxy. From the transparency and versatility of epoxy resins, they are one or more epoxy resins composed of glycidyl ether type epoxy resins and cyclic aliphatic epoxy resin groups. Preferably Yes.

Moreover, as a silicone resin, the thing of the two-component condensation hardening type hardening system is mentioned, for example, Since the cure rate is quick, the silicone resin which has an alkoxy group is preferable.
Examples of the two-component condensation curable silicone resin include KE-200 and KE-513 (both manufactured by Shin-Etsu Chemical Co., Ltd.).
Examples of the silicone resin having an alkoxy group include KE-66, KE-118, KE-108, and KE-119 (all manufactured by Shin-Etsu Chemical Co., Ltd.).

  The surface-modified zirconia particles are 1 to 400 parts by weight, preferably 50 to 100 parts by weight with respect to 100 parts by weight of the epoxy resin or silicone resin. This is because when the surface-modified zirconia particles are less than 1 part by weight, the refractive index is not increased, and when it exceeds 400 parts by weight, the cured resin becomes cloudy and becomes not transparent.

  When the zirconia-containing resin composition of the present invention contains an epoxy resin, it is preferable to further contain an acid anhydride and / or a photocationic polymerization initiator in order to obtain a cured product.

Examples of the acid anhydride include dodecenyl succinic anhydride, polyadipine anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhymic anhydride, hexahydrophthalic anhydride, phthalic anhydride, trimellitic anhydride, Examples include pyromellitic anhydride, and methylhexahydrophthalic anhydride is preferable because of excellent yellowing resistance.
What is acid anhydride? The amount is preferably 10 to 200 parts by weight and more preferably 10 to 100 parts by weight with respect to 100 parts by weight of the epoxy resin.

Examples of the cationic photopolymerization initiator include aromatic sulfonium antimonate salts, aromatic sulfonium arsenate salts, aromatic sulfonium phosphanate salts, aromatic sulfonium borate salts, and the like, from the viewpoint of initiator efficiency. Group sulfonium antimonate salts are preferred.
0.01-10 weight part is preferable with respect to 100 weight part of epoxy resins, and a photocationic polymerization initiator has more preferable 0.1-1 weight part.

In order to obtain the zirconia-containing resin composition of the present invention, there is no particular limitation and a known method can be used. Examples thereof include a method of adding surface-modified zirconia powder to the resin.
Specifically, 1 to 400 parts by weight of surface-modified zirconia is added to 100 parts by weight of epoxy resin or silicone resin and stirred to obtain a zirconia-containing resin composition.

In order to obtain the zirconia-containing epoxy resin composition containing the acid anhydride and / or photocationic polymerization initiator of the present invention, there is no particular limitation, and a known method can be used. For example, a zirconia-containing epoxy resin composition can be used. The method of mixing an acid anhydride, the method of adding a photocationic polymerization initiator solution to a zirconia containing epoxy resin composition, etc. are mentioned.
Specifically, 10 to 200 parts by weight of acid anhydride or a cationic photopolymerization initiator solution (containing 0.01 to 10 parts by weight of initiator) is added to 100 parts by weight of the zirconia-containing epoxy resin composition. A method etc. can be illustrated.

  The zirconia-containing resin composition of the present invention may contain a heat-resistant agent, a dye, a pigment, a flame retardant, and the like as other optional components as long as the object of the present invention is not impaired.

The zirconia-containing resin composition of the present invention is preferably a cured product because of its excellent transparency, and the cured product is obtained by curing the zirconia-containing resin composition of the present invention with light and / or heat. There is no particular limitation.
As a method for obtaining a zirconia-containing epoxy resin cured product, for example, it can be obtained by heating a zirconia-containing epoxy resin composition containing an acid anhydride at 100 ° C. × 2 hours + 150 ° C. × 3 hours.
It can also be obtained by irradiating the zirconia-containing epoxy resin composition containing the cationic photopolymerization initiator with 10 mW / cm ² of ultraviolet rays for 5 minutes.
A cured product using the zirconia-containing resin composition thus obtained has excellent transparency and a high refractive index.

  The present invention will be described in more detail with reference to the following examples. However, these are examples to help understanding of the present invention, and the present invention is not limited to these examples.

[Reagents, etc.]
Reagents and the like used in Examples and Comparative Examples are expressed using the following abbreviations (commercially available products are used for other reagents).
<Glycidyl ether type epoxy resin>
Bisphenol A diglycidyl ether, YD-128, manufactured by Nippon Steel Chemical Co., Ltd. <Cyclic aliphatic epoxy resin>
3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate: Celoxide (registered trademark) 2021P, manufactured by Daicel Corporation <Carboxylic acid>
Hydroxycarboxylic acid: o-hydroxybenzoic acid

<Acid anhydride>
Acid anhydride (I): 4-methylhexahydrophthalic anhydride, Ricacid MH, Shin Nippon Chemical Co., Ltd. <Curing Accelerator>
Curing accelerator (I): 1-methylimidazole, Tokyo Chemical Industry Co., Ltd. <Photocationic polymerization initiator>
Triphenylsulfonium hexafluoroantimonate salt: Adekaoptomer (registered trademark) SP-170, manufactured by Adeka Corporation

[Physical property testing method]
<Volume average particle diameter>
The volume average particle diameter is a value obtained by measuring 500 particles using a transmission electron microscope (JEM-2000FX, manufactured by JEOL Ltd.) and volume average.
<Transparency evaluation>
It was evaluated by visual observation that there was no cloudiness.
<Refractive index measurement>
Measurement was performed using an Abbe refractometer (ATAGO DM-M4, manufactured by Atago Co., Ltd.).

Example 1
[Preparation of zirconia aqueous dispersion]
To a zirconium salt solution in which 100 g of zirconium oxychloride octahydrate is dissolved in 1.5 L (liter) of pure water, dilute ammonia water in which 13 g of 28% ammonia water is dissolved in 1.0 L of pure water is added with stirring, and zirconia is added. A precursor slurry was prepared.
Next, an aqueous sodium sulfate solution in which 11 g of sodium sulfate was dissolved in 0.2 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, washing was performed using a centrifugal separator, and the added sodium sulfate was sufficiently removed, followed by drying in a drier to produce zirconia particles.
Next, 82.5 g of water as a dispersion solvent was added to 10 g of the zirconia particles and mixed, and then dispersion treatment was performed by a bead mill using 0.1 mmφ zirconia beads to prepare a zirconia aqueous dispersion. The volume average particle diameter of zirconia particles in this zirconia aqueous dispersion was 3 nm.

[Surface modification of zirconia with hydroxycarboxylic acid]
12 mL of methanol, 1 mL of toluene, and 0.09 g of o-hydroxybenzoic acid (30 parts by weight with respect to 100 parts by weight of zirconia particles) were added to 3 mL of a zirconia aqueous dispersion having a concentration of 10 wt%. The resulting mixture was stirred for 1 hour at room temperature and then azeotroped to remove water and replace the solvent with toluene to prepare a toluene dispersion. When 1 mL of this toluene dispersion was dried, 0.35 g of white surface-modified zirconia particles was obtained. This is designated as surface-modified zirconia particles (I).

[Production of zirconia-containing epoxy resin composition containing acid anhydride]
A zirconia-containing epoxy resin composition containing an acid anhydride is prepared by adding 0.9 g of acid anhydride (I) and 0.5 g of surface-modified zirconia particles (I) to 1 g of glycidyl ether-type epoxy resin. did.

[Preparation of cured zirconia-containing epoxy resin using acid anhydride as curing agent]
0.07 g of curing accelerator (I) was added to the zirconia-containing epoxy resin composition containing the obtained acid anhydride and stirred. This was heated in a separable beaker under a nitrogen atmosphere at 100 ° C. for 2 hours and at 150 ° C. for 3 hours to obtain a cured resin. Since the obtained resin cured product did not become cloudy, it was visually confirmed that it had transparency. Moreover, it was 1.58 when the refractive index measurement was performed about the obtained resin cured material.

Example 2
[Preparation of a zirconia-containing epoxy resin composition containing a cationic photopolymerization initiator]
1 g of glycidyl ether type epoxy resin, 0.5 g of surface-modified zirconia particles (I) prepared in Example 1, and 0.01 g of triphenylsulfonium hexafluoride antimonate salt (solvent: propylene carbonate, 0.005 g of polymerization initiator) A zirconia-containing epoxy resin composition containing a cationic photopolymerization initiator (50 parts by weight of surface-modified zirconia and 0.5 parts by weight of a cationic photopolymerization initiator with respect to 100 parts by weight of the epoxy resin). did.

[Preparation of cured zirconia-containing epoxy resin with cationic photopolymerization initiator]
The cured resin was obtained by irradiating the obtained zirconia-containing epoxy resin composition containing the cationic photopolymerization initiator with ultraviolet rays of 10 mW / cm ² for 5 minutes. Since the obtained resin cured product did not become cloudy, it was visually confirmed that it had transparency.

Example 3
[Production of zirconia-containing epoxy resin composition containing acid anhydride]
Zirconia containing acid anhydride by adding 0.9 g of acid anhydride (I) and 0.5 g of surface-modified zirconia particles (I) prepared in Example 1 to 1 g of cycloaliphatic epoxy resin An epoxy resin composition was prepared.

[Preparation of cured zirconia-containing epoxy resin using acid anhydride as curing agent]
In the same manner as in Example 1, 0.07 g of the curing accelerator (I) was added to the obtained zirconia-containing epoxy resin composition containing an acid anhydride and stirred. This was heated in a separable beaker under a nitrogen atmosphere at 100 ° C. for 2 hours and at 150 ° C. for 3 hours to obtain a cured resin. Since the obtained resin cured product did not become cloudy, it was visually confirmed that it had transparency.

Example 4
[Preparation of a zirconia-containing epoxy resin composition containing a cationic photopolymerization initiator]
To 1 g of cycloaliphatic epoxy resin, 0.5 g of surface-modified zirconia particles (I) prepared in Example 1 and 0.01 g of a cationic photopolymerization initiator (solvent: containing propylene carbonate and 0.005 g of a polymerization initiator) are added. A zirconia-containing epoxy resin composition containing a cationic photopolymerization initiator (50 parts by weight of surface-modified zirconia particles and 0.5 parts by weight of a cationic photopolymerization initiator with respect to 100 parts by weight of the epoxy resin) was prepared.

[Preparation of cured zirconia-containing epoxy resin with cationic photopolymerization initiator]
The cured resin was obtained by irradiating the obtained zirconia-containing epoxy resin composition containing the cationic photopolymerization initiator with ultraviolet rays of 10 mW / cm ² for 5 minutes. Since the obtained resin cured product did not become cloudy, it was visually confirmed that it had transparency.

Comparative Example 1
[Surface modification of zirconia with carboxylic acid]
Methanol 12 mL, toluene 1 mL, and hexanoic acid 0.09 g (30 parts by weight with respect to 100 parts by weight of zirconia particles) were added to 3 mL of a zirconia aqueous dispersion having a concentration of 10 wt%. The resulting mixture was stirred for 1 hour at room temperature and then azeotroped to remove water and replace the solvent with toluene to prepare a toluene dispersion. When 1 mL of this toluene dispersion was dried, 0.35 g of white zirconia particles surface-modified with hexanoic acid that was not hydroxycarboxylic acid was obtained. This is designated as surface-modified zirconia particles (II).

[Production of zirconia-containing epoxy resin composition containing acid anhydride]
A zirconia-containing epoxy resin composition containing an acid anhydride is prepared by adding 0.9 g of acid anhydride (I) and 0.5 g of surface-modified zirconia particles (II) to 1 g of glycidyl ether-type epoxy resin. did.

[Preparation of cured zirconia-containing epoxy resin using acid anhydride as curing agent]
0.07 g of curing accelerator (I) was added to the zirconia-containing epoxy resin composition containing the obtained acid anhydride and stirred. This was heated in a separable beaker under a nitrogen atmosphere at 100 ° C. for 2 hours and at 150 ° C. for 3 hours to obtain a cured resin. The obtained cured resin was cloudy, and a zirconia-containing epoxy resin cured product having transparency was not obtained.

Comparative Example 2
[Preparation of a zirconia-containing epoxy resin composition containing a cationic photopolymerization initiator]
To 1 g of cycloaliphatic epoxy resin, 0.5 g of surface-modified zirconia particles (II) and 0.01 g of photocationic polymerization initiator (solvent: containing propylene carbonate and 0.005 g of polymerization initiator) are added to initiate photocationic polymerization. A zirconia-containing epoxy resin composition containing an agent (50 parts by weight of surface-modified zirconia and 0.5 parts by weight of a cationic photopolymerization initiator with respect to 100 parts by weight of the epoxy resin) was prepared.

[Preparation of cured zirconia-containing epoxy resin with cationic photopolymerization initiator]
The cured resin was obtained by irradiating the obtained zirconia-containing epoxy resin composition containing the cationic photopolymerization initiator with ultraviolet rays of 10 mW / cm ² for 5 minutes. The obtained cured resin was cloudy, and a zirconia-containing epoxy resin cured product having transparency was not obtained.

The surface-modified zirconia particles of the present invention, the zirconia-containing resin composition using the particles, and the cured product have excellent transparency and a high refractive index. For example, LED (light emitting diode) or organic EL (organic) It is useful as a material for improving the light extraction efficiency of electroluminescence.

Claims (4)

1 to 400 parts by weight of surface-modified zirconia particles in which zirconia particles having a volume average particle diameter of 1 to 20 nm are modified with hydroxycarboxylic acid with respect to 100 parts by weight of epoxy resin , and initiation of acid anhydride and / or photocationic polymerization A zirconia-containing resin composition comprising an agent . The zirconia-containing resin composition according to claim 1, wherein the hydroxycarboxylic acid is hydroxybenzoic acid. The zirconia-containing resin composition according to claim 1 or 2 , wherein the epoxy resin is at least one epoxy resin selected from the group consisting of a glycidyl ether type epoxy resin and a cyclic aliphatic epoxy resin. A cured zirconia-containing resin obtained by curing the zirconia-containing resin composition according to any one of claims 1 to 3 .