JP2017002112A - Curable composition, cured article thereof, hard coat material and hard coat film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition capable of forming a hard coat film having high refractive index, substrate adhesion, light resistance and alkali resistance at the same time.SOLUTION: A curable composition contains (A) an organic inorganic composite where a silane coupling agent having a (meth)acryloyl group and an alkoxysilyl group binds to a first inorganic oxide fine particle, (B) a polyfunctional (meth)acrylate monomer having at lest 2 (meth)acryloyl group, (C) a polymerization initiator and (D) a second inorganic oxide fine particle which is a different kind of inorganic fine particle from the first inorganic oxide fine particle at a predetermined ratio. A ratio of V1 and V2, V1/V2 satisfies a formulation 0.7<V1/V2<1.5 and both of V1 and V2 are -50 (mV) or less, where V1 (mV) is zeta potential of the organic inorganic composite (A) and V2 (mV) is zeta potential of the second inorganic oxide fine particle (D).SELECTED DRAWING: None

Description

  The present invention relates to a curable composition that can be cured, and a cured product obtained by curing the curable composition. The present invention also relates to the application of the curable composition as a hard coat material and a hard coat film formed using the hard coat material.

Surfaces such as plastic sheets and plastic films are relatively soft, have poor scratch resistance and low pencil hardness, so improving the performance by providing a hard coat film on the surface of these articles to increase the surface hardness Is planned.
Further, by providing a hard coat film on these articles, various performances can be imparted in addition to scratch resistance and pencil hardness. For example, the refractive index can be improved by providing a hard coat film.

  In the field of touch panels, which have been developed in recent years, an ITO (Indium Tin Oxide) layer as a transparent conductive electrode is formed on a hard-coated film, but the refractive index difference between the ITO layer and the hard-coated film is large. Since the reflectance increases and the total light transmittance decreases and the visibility decreases, the smaller the refractive index difference between the ITO layer and the hard coat treatment film, the better.

  As a method for improving the refractive index of the hard coat film, there is a method of blending metal oxide particles such as titanium, zirconium, zinc, indium tin, antimony tin, and aluminum into the hard coat film. The method of blending the metal oxide fine particles can obtain a hard coat film having a high refractive index while maintaining high hardness and scratch resistance. For example, Patent Documents 1 and 2 describe coating compositions containing metal oxide fine particles such as titania.

In the technique disclosed in Patent Document 1, a coating composition containing a titania fine particle and an organosilicon compound is coated on a substrate by a dipping method, and then heated and thermally cured to obtain a transparent high refractive index. A coating is obtained.
In the technique disclosed in Patent Document 2, a coating film having excellent pencil hardness and scratch resistance is obtained by treating the surface of titania fine particles with a polysiloxane compound having an unsaturated group.

JP 2002-129102 A JP 2012-220556 A

However, since titania fine particles have high ultraviolet absorptivity, there is a possibility that ultraviolet rays may not reach the deep part when the composition is cured with ultraviolet rays. For this reason, the adhesion strength may be insufficient, or the resistance when immersed in an alkaline solution may be insufficient.
Although the technique disclosed in Patent Document 1 supplements the adhesion by performing an alkali treatment or the like on a plastic molded body as a base material, there is no disclosure about improving the adhesion of the coating composition itself. Moreover, the technique disclosed in Patent Document 2 does not disclose that the base material is glass and the adhesion to a plastic base material is improved.

  Therefore, the present invention solves the problems of the prior art as described above, and can form a hard coat film having high refractive index, substrate adhesion, light resistance, and alkali resistance at the same time. It is another object of the present invention to provide a hard coat material. Moreover, this invention makes it a subject to provide the hard-coat film | membrane and hardened | cured material which have high refractive index, base-material adhesiveness, light resistance, and alkali resistance simultaneously.

In order to solve the above problems, one embodiment of the present invention is as described in [1] to [5] below.
[1] An organic-inorganic composite (A) in which a silane coupling agent having a (meth) acryloyl group and an alkoxysilyl group and the first inorganic oxide fine particles are bonded,
A polyfunctional (meth) acrylate monomer (B) having at least two (meth) acryloyl groups;
A polymerization initiator (C);
Second inorganic oxide fine particles (D) which are different types of inorganic oxide fine particles from the first inorganic oxide fine particles;
Containing
When the content of the polyfunctional (meth) acrylate monomer (B) having at least two (meth) acryloyl groups is 100 parts by mass, the organic-inorganic composite (A) and the second inorganic oxide fine particles ( D) is 100 parts by mass or more and 700 parts by mass or less, and the content of the polymerization initiator (C) is 5 parts by mass or more and 40 parts by mass or less,
When the zeta potential of the organic-inorganic composite (A) is V1 (mV) and the zeta potential of the second inorganic oxide fine particles (D) is V2 (mV), the ratio V1 / V2 of V1 and V2 is A curable composition satisfying the formula 0.7 <V1 / V2 <1.5, and V1 and V2 are both -50 (mV) or less.

[2] The curable composition according to [1], wherein the first inorganic oxide fine particles contain titania and the second inorganic oxide fine particles (D) mainly contain zirconia.
[3] A cured product obtained by curing the curable composition according to [1] or [2].
[4] A hard coat material comprising the curable composition according to [1] or [2].
[5] A hard coat film formed by arranging the hard coat material according to [4] on the surface of a base material in a film shape and curing it.

The curable composition and the hard coat material of the present invention can form a hard coat film having a high refractive index, substrate adhesion, light resistance, and alkali resistance at the same time.
In addition, the hard coat film and the cured product of the present invention have a high refractive index, substrate adhesion, light resistance, and alkali resistance at the same time.

Embodiments of the present invention will be described in detail. In the present invention, “(meth) acrylate” means methacrylate and / or acrylate, “(meth) acryloyl” means methacryloyl and / or acryloyl, and “(meth) acryl” means methacryl and / or Means acrylic.
As a result of intensive studies to solve the various problems of the above-described conventional technology, the present inventors have found that a silane coupling agent having a (meth) acryloyl group and an alkoxysilyl group is bonded to inorganic oxide fine particles. Organic inorganic composites, polyfunctional (meth) acrylate monomers having at least two (meth) acryloyl groups, and inorganic oxide fine particles of a type different from the inorganic oxide fine particles constituting the organic / inorganic composite, The present inventors have found that the above problems can be solved by combining them, and have completed the present invention.

  That is, the curable composition of the present invention comprises an organic-inorganic composite (A) in which a silane coupling agent having a (meth) acryloyl group and an alkoxysilyl group and the first inorganic oxide fine particles are bonded, and at least The polyfunctional (meth) acrylate monomer (B) having two (meth) acryloyl groups, the polymerization initiator (C), and the first inorganic oxide fine particles are different types of inorganic oxide fine particles. Organic inorganic composite (A) when the content of the polyfunctional (meth) acrylate monomer (B) containing inorganic oxide fine particles (D) and having at least two (meth) acryloyl groups is 100 parts by mass ) And the second inorganic oxide fine particles (D) are 100 parts by mass or more and 700 parts by mass or less, and the content of the polymerization initiator (C) is 5 parts by mass or more and 40 parts by mass or less. It is characterized in.

  The organic-inorganic composite (A) is obtained by, for example, treating the first inorganic oxide fine particles with a silane coupling agent having a (meth) acryloyl group and an alkoxysilyl group to form the first inorganic oxide fine particles into the silane It can be obtained by covalently binding the coupling agent. A cured product and hard coat film of such a curable composition obtained by copolymerizing and curing (for example, ultraviolet curing) the organic-inorganic composite (A) and the polyfunctional (meth) acrylate monomer (B) are organic and inorganic. In addition to the high degree of cross-linking of the surface of the composite (A), it has a high pencil hardness because of its high elastic modulus due to the construction of a uniform cross-linking system. In addition, since the drop of the first inorganic oxide fine particles caused by surface abrasion is prevented by crosslinking, the cured product of the curable composition and the hard coat film also have high scratch resistance.

  Further, the curable composition contains second inorganic oxide fine particles (D). The second inorganic oxide fine particles (D) improve the refractive index without impairing the characteristics such as light resistance and hardness of the cured product of the curable composition and the hard coat film. Further, by selecting inorganic oxide fine particles having good curability, it is possible to improve process suitability for balancing light resistance, alkali resistance and curability.

  However, when two different inorganic oxide fine particles coexist in the same system, the inorganic oxide fine particles have a low zeta potential, a large difference in absolute value, or an inorganic having a surface potential with different positive and negative. Since the inorganic oxide fine particles may be aggregated due to the presence of the oxide fine particles, the zeta potential of the inorganic oxide fine particles must be appropriately selected.

Below, each component of the curable composition of this embodiment and the material for manufacturing this component are demonstrated.
<(1) Organic-inorganic composite (A)>
The organic-inorganic composite (A) includes a silane coupling agent having a (meth) acryloyl group and an alkoxysilyl group (hereinafter referred to as “(meth) acrylic silane coupling agent (A-1)”) and the first inorganic It can be obtained by dehydration condensation reaction or dealcoholization condensation reaction with oxide fine particles (A-2).

  Since the first inorganic oxide fine particles (A-2) have a large number of hydroxy groups (OH groups) on their surfaces, the hydroxy groups and the (meth) acrylic silane coupling agent (A-1) By the condensation reaction with the alkoxysilyl group, the (meth) acrylic silane coupling agent (A-1) and the first inorganic oxide fine particles (A-2) can be bonded by a covalent bond.

<(1-1) (Meth) acrylic silane coupling agent (A-1)>
The (meth) acrylic silane coupling agent (A-1) is not particularly limited as long as it has a (meth) acryloyl group and an alkoxysilyl group. For example, (meth) acryloyloxypropyltri Examples thereof include methoxysilane, (meth) acryloyloxypropyltriethoxysilane, (meth) acryloyloxypropylmethyldimethoxysilane, (meth) acryloyloxypropylmethyldiethoxysilane, and a compound represented by the following chemical formula (II).

However, M in the chemical formula (I) represents a hydroxyl group residue of a compound having at least two (meth) acryloyl groups and at least one hydroxy group. X represents an oxygen atom or a sulfur atom. Further, R ² and R ³ are linear, branched or cyclic alkyl groups or phenyl groups having 1 to 10 carbon atoms (which may have an alkyl group having 1 to 3 carbon atoms). R ² and R ³ may be the same or different. Further, R ¹ represents a linear, branched, or cyclic alkylene group having 1 to 10 carbon atoms or a phenylene group (which may have an alkyl group having 1 to 3 carbon atoms), This alkylene group may contain an oxygen atom in the chain. Further, l represents an integer from 0 to 2, m represents an integer from 1 to 3, the sum of l and m is 3, and k represents an integer from 1 to 3.

The compound represented by the chemical formula (I) can be obtained by a condensation reaction between a compound having an alkoxysilyl group and an isocyanato group and a compound having at least two (meth) acryloyl groups and at least one hydroxy group. . This condensation reaction is a condensation reaction in which an isocyanato group and a hydroxy group react to form a urethane bond.
Hereinafter, the (meth) acrylic silane coupling agent will be described in more detail.

The (meth) acrylic silane coupling agent is, for example, a compound (a-1) having an alkoxysilyl group and an isocyanato group, and an organic group that can be condensed with an isocyanato group (hydroxy group, mercapto group, amino group, carboxyl group, etc. ) And a compound (a-2) having at least two (meth) acryloyl groups.
Examples of the compound (a-1) include, but are not limited to, 3-isocyanatopropyltrimethoxysilane and 3-isocyanatopropyltriethoxysilane. Moreover, these can also be used individually by 1 type and can also use 2 or more types together.

  Examples of the compound (a-2) include glycerin di (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, and 3-hydroxy-2- (meth) acrylic. Leuoxypropyl (meth) acrylate, bis ((meth) acryloyloxyethyl) -2-hydroxyethyl isocyanurate, pentaerythritol tri (meth) acrylate, pentaerythritol di (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, Examples thereof include dipentaerythritol penta (meth) acrylate and dipentaerythritol tetra (meth) acrylate.

Furthermore, a cyclic acid is formed by a (meth) acrylic copolymer having an active hydrogen group such as a hydroxy group, an amino group, a mercapto group, and a carboxyl group and a (meth) acryloyl group in the side chain, or a polyfunctional acrylate having a hydroxy group. Examples include compounds formed by ring opening of anhydrides.
However, a compound (a-2) is not restricted to these, These can also use 1 type individually and can also use 2 or more types together.

  Furthermore, as the compound (a-2), a compound having a hydroxy group is preferable because it has no reactivity with an unsaturated group and can be easily controlled, and has a moderate reactivity with an isocyanato group. . In particular, pentaerythritol tri (meth) acrylate, pentaerythritol di (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol tetra (meth) acrylate are preferable.

In the condensation reaction between the compound (a-1) and the compound (a-2), the following can be used as a catalyst for the reaction. Examples of the catalyst include tin, zirconia, titania, zinc, iron, nickel, bismuth, chromium, cobalt, amine, and phosphorus. The reaction temperature is preferably 20 ° C or higher and 60 ° C or lower, and more preferably 30 ° C or higher and 55 ° C or lower.
The reaction solvent is not particularly limited, but in order to promote the condensation reaction, it is preferable to use a solvent having a small solvation. For example, nonpolar solvents such as cyclohexane, methylcyclohexane, benzene, toluene, xylene, and dichloromethane can be used. Of these, toluene is most preferable from the viewpoints of compatibility with organic substances, low water absorption, and relatively easy distillation.

<(1-2) First inorganic oxide fine particles (A-2)>
Next, the following substances can be used for the first inorganic oxide fine particles (A-2). For example, silica, hollow silica, alumina, zirconia, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, antimony tin oxide (ATO), cerium oxide, potassium oxide, Among these, a composite oxide in which two or more kinds are combined can be given. In particular, when it is desired to obtain a cured product having a high refractive index, zirconia, titania and antimony tin oxide are preferred from the viewpoint of particle refractive index, handling and transparency, and titania is most preferred.

  The first inorganic oxide fine particles (A-2) are preferably used as an organic solvent-dispersed sol dispersed in an organic solvent. The organic solvent used as the dispersion medium is not particularly limited. For example, alcohols such as methanol, ethanol, isopropanol, butanol, octanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, acetic acid Esters such as butyl, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethers such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether, and aromatic hydrocarbons such as benzene, toluene and xylene And amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Among these, methanol and isopropanol are preferable because the dispersion stability of the first inorganic oxide fine particles (A-2) is good.

  Furthermore, the average primary particle diameter of the first inorganic oxide fine particles (A-2) is preferably 1 nm or more and 200 nm or less, particularly preferably 5 nm or more and 100 nm or less from the viewpoint of handling and transparency. If the average primary particle diameter is 1 nm or more, the particle surface has low activity, and thus it is easy to maintain a dispersed state, and aggregation and gelation are unlikely to occur. On the other hand, if the average primary particle diameter is 200 nm or less, haze due to Rayleigh scattering is difficult to observe. Since Rayleigh scattering is proportional to the square of the particle volume, that is, the sixth power of the particle diameter, scattering is small for particles having an average primary particle diameter of ¼ or less of the wavelength of visible light, and is suitable for a transparent material. Can be used.

The average primary particle size is determined by, for example, observing the first inorganic oxide fine particles with a high-resolution transmission electron microscope (H-9000 type, manufactured by Hitachi, Ltd.), and arbitrarily selecting 100 inorganic oxides from the observed fine particle image. An object particle image can be selected and obtained as a number average particle diameter by a known image data statistical processing technique.
As a product marketed as an organic solvent-dispersed sol of silica fine particles, for example, colloidal silica includes OSCAL-1132, OSCAL-1432M, OSCAL-1432, OSCAL-1632 manufactured by JGC Catalysts & Chemicals, and Nissan Chemical Industries, Ltd. Methanol silica sol, MA-ST-L, IPA-ST, IPA-ST-L, IPA-ST-ZL, IPA-ST-UP, PGM-ST, MEK-ST, MEK-ST-L, MEK-ST- ZL, MIBK-ST, PMA-ST, EAC-ST, Fuso Chemical Co., Ltd. PL-1-IPA, PL-2L-PGME, PL-2L-MEK, etc. can be mentioned.

  Examples of products that are commercially available as organic solvent-dispersed sols of zirconia fine particles include Nanouse (trademark) OZ-30M and Nanouse (trademark) OZ-S30K manufactured by Nissan Chemical Industries, Ltd. Furthermore, examples of products that are commercially available as organic solvent-dispersed sols of titania fine particles include OPTOLAKE 1130Z and OPTPLAKE 6320Z manufactured by JGC Catalysts & Chemicals.

  Examples of the shape of the first inorganic oxide fine particles (A-2) include a spherical shape, a hollow spherical shape, a bead shape, a flat plate shape, and a fibrous shape. However, the spherical shape and the hollow shape are favorable in terms of handling properties and dispersibility. A bead shape is preferable, and a spherical shape is particularly preferable. Examples of beaded silica include IPA-ST-UP (trade name) manufactured by Nissan Chemical Industries, Ltd., and examples of hollow silica include sulria (trade name) manufactured by JGC Catalysts & Chemicals. Can be mentioned.

<(1-3) Synthesis of organic-inorganic composite (A)>
<Surface modification (surface treatment)>
The organic-inorganic composite (A) is mixed by adding the (meth) acrylic silane coupling agent (A-1) and a small amount of water to the solvent in which the first inorganic oxide fine particles (A-2) are dispersed. By stirring, it is obtained by advancing a dehydration condensation reaction or a dealcoholization condensation reaction.

Furthermore, if necessary, an acid or a basic compound may be added as a catalyst, and examples thereof include acetic acid, hydrochloric acid, nitric acid, sulfuric acid, and aqueous ammonia.
The temperature of the condensation reaction is preferably 10 ° C. or higher and 80 ° C. or lower, more preferably 20 ° C. or higher and 60 ° C. or lower, and further preferably 35 ° C. or higher and 55 ° C. or lower. If the reaction temperature is 10 ° C. or higher, the condensation reaction between the first inorganic oxide fine particles (A-2) and the (meth) acrylic silane coupling agent (A-1) is likely to proceed, and the target compound is sufficient. Easy to obtain. On the other hand, if it is 80 ° C. or lower, radical generation due to heat hardly occurs, and therefore gelation due to polymerization of unsaturated groups in the system hardly occurs.

  As the condensation reaction solvent, the dispersion medium of the first inorganic oxide fine particles (A-2) can be used, but from the viewpoint of compatibility with the surface of the first inorganic oxide fine particles (A-2), Protic solvents such as water, methanol, ethanol, isopropanol, butanol, octanol, propylene glycol monomethyl ether are preferred, and both solvation strength and surface reactivity of the first inorganic oxide fine particles (A-2) are preferred. In view of the above, methanol and isopropanol are most preferable.

  The amount of the (meth) acrylic silane coupling agent (A-1) used for the surface treatment of the first inorganic oxide fine particles (A-2) is the first inorganic oxide fine particles that are not surface-treated ( A-2) 10 parts by mass or more and 100 parts by mass or less are preferable, 100 parts by mass or more and 95 parts by mass or less are more preferable, and 20 parts by mass or more and 90 parts by mass or less are more preferable. If the amount of the (meth) acrylic silane coupling agent (A-1) used is 10 parts by mass or more, a sufficient condensation reaction is performed on the surface of the first inorganic oxide fine particles (A-2). There is no possibility of reducing the dispersibility of the first inorganic oxide fine particles (A-2). On the other hand, if it is 100 parts by mass or less, the crosslink density does not become too high, so that the hard coat film is hardly warped or cracked.

  In addition, the surface treatment of the first inorganic oxide fine particles (A-2) is used in combination with the (meth) acrylic silane coupling agent (A-1) and the other silane coupling agent (A-4). You can also Examples of silane coupling agents that can be used in combination are not particularly limited, but include unsaturated group-containing products such as vinyltrimethoxysilane, vinyltriethoxysilane, and p-styryltrimethoxysilane, methyltrimethoxysilane, and dimethyldimethoxy. Silane, phenyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, Examples include decyltriethoxysilane, trifluorotrimethoxysilane, and alkoxysilane compounds having a perfluoropolyether group having a repeating unit in the molecule.

Next, while removing water or alcohol produced by the dehydration condensation reaction or the dealcoholization condensation reaction and the condensation reaction solvent from the condensation reaction solution, a substitution solvent is added to perform solvent substitution, A solvent dispersion in which the organic-inorganic composite (A) is dispersed may be obtained (solvent replacement step).
The kind of the substitution solvent is not particularly limited, and solvents such as ketone, ester, aromatic hydrocarbon, aliphatic hydrocarbon, alcohol, amide, and ether can be used. The addition of the polymerization inhibitor is preferably performed in this solvent replacement step.

And in the solvent dispersion liquid, polyfunctional (meth) acrylate monomer (B) having at least two (meth) acryloyl groups, polymerization initiator (C), second inorganic oxide fine particles (D), Can be mixed to produce the curable composition (hard coat material).
Since the dehydration condensation reaction or dealcoholization condensation reaction between the first inorganic oxide fine particles (A-2) and the silane coupling agent is an equilibrium reaction, a reverse reaction (decomposition reaction) may also occur. When the reverse reaction occurs, the performances of the cured product (hard coat film) obtained by curing the curable composition (hard coat material) may be insufficient.

  In the curable composition (hard coat material) of the present embodiment, the water or alcohol produced by the dehydration condensation reaction or the dealcoholization condensation reaction and the condensation reaction solvent are removed by the solvent replacement step, and the water or alcohol is removed. Or the content of the condensation reaction solvent is reduced, the equilibrium shifts in the direction in which a dehydration condensation reaction or a dealcoholization condensation reaction occurs, and the reverse reaction hardly occurs. Therefore, the various performances of the cured product (hard coat film) obtained by curing the curable composition (hard coat material), that is, pencil hardness and scratch resistance are excellent.

  In addition, the polyfunctional (meth) acrylate monomer which has at least 2 (meth) acryloyl group in the dispersion liquid of the organic inorganic composite (A) obtained by the surface treatment of the first inorganic oxide fine particles (A-2) (B), a substitution solvent, and a polymerization inhibitor may be added and subjected to a solvent substitution step to perform solvent substitution. As a result, a dispersion containing the polyfunctional (meth) acrylate monomer (B), the organic-inorganic composite (A), and the substitution solvent can be obtained. Here, the polymerization initiator (C) and the second inorganic oxide are obtained. If the fine particles (D) are mixed, the curable composition (hard coat material) can be produced.

<(2) Polyfunctional (meth) acrylate monomer (B) having at least two (meth) acryloyl groups>
Examples of the polyfunctional (meth) acrylate monomer (B) having at least two (meth) acryloyl groups (also referred to as “polyfunctional (meth) acrylate monomer (B)” in the present specification) include: Examples include (meth) acrylic acid ester (B-1), epoxy (meth) acrylate (B-2), and urethane (meth) acrylate (B-3).

<(2-1) (Meth) acrylic acid ester (B-1)>
Specific examples of the (meth) acrylic acid ester (B-1) include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. , Propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1, Diacrylates such as 6-hexanediol di (meth) acrylate, tricyclodecane di (meth) acrylate, bisphenol A di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Taerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tris (2- (meth) Examples thereof include, but are not limited to, polyfunctional (meth) acrylates such as (acryloyloxyethyl) isocyanurate, and ethylene oxide modified products and propylene oxide modified products thereof. Among these, from the viewpoint of improving the hardness and scratch resistance of the cured product, a tri- or higher functional (meth) acrylate monomer is preferable, and a mixture of pentaerythritol tetraacrylate and pentaerythritol triacrylate is most preferable. Moreover, these compounds can also be used individually by 1 type, and can also use 2 or more types together.

<(2-2) Epoxy (meth) acrylate (B-2)>
The epoxy (meth) acrylate (B-2) can be obtained by reacting an epoxy compound with a carboxylic acid having a (meth) acryloyl group. Specific examples of the epoxy compound include glycidyl (meth) acrylate, glycidyl ethers having both ends of a linear alcohol having 1 to 12 carbon atoms, diethylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and bisphenol A diglycidyl. Examples include ether, ethylene oxide-modified bisphenol A diglycidyl ether, propylene oxide-modified bisphenol A diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, hydrogenated bisphenol A diglycidyl ether, and glycerin diglycidyl ether. Examples of the carboxylic acid having a (meth) acryloyl group include (meth) acrylic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, and the like.

<(2-3) Urethane (meth) acrylate (B-3)>
Urethane (meth) acrylate (B-3) is an alcohol compound (B-3-1), a polyfunctional thiol compound (B-3-2), or a polyfunctional amine compound (B-3-3). It can be obtained by reacting a (meth) acryloyl group-containing isocyanate compound (B-3-4). Alternatively, the alcohol compound (B-3-1) and the isocyanate compound (B-3-5) are subjected to a condensation reaction under conditions where the isocyanate group is excessive to synthesize a polyurethane compound having an isocyanate group at the terminal, and then a terminal isocyanate group. It can be obtained by subjecting an alcohol compound (B-3-6) having a (meth) acryloyl group to a condensation reaction. The number of (meth) acryloyl groups possessed by the urethane (meth) acrylate (B-3) is preferably 4 or more and 10 or less.

  Specific examples of the alcohol compound (B-3-1) include (meth) acryloyloxy group-containing alcohols such as 2-hydroxyethyl acrylate, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, glycerin, polyglycerin, tris (2-hydroxyethyl) isocyanurate, 1,3,5-trihydroxypentane, 1,4-dithian-2,5-dimethanol tricyclodecanediol, tri Methylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, norbornane dimethanol, polycarbonate diol, polysiloxane diol, bisphenol A, hydrogenated bisphenol A, perfluoroalcohol, perfluoropolyether Alcohol, and their EO (ethylene oxide) modified products, PO (propylene oxide) modified products, caprolactone-modified products thereof.

  Moreover, as a polyfunctional thiol compound (B-3-2), a C2-C20 linear, branched or cyclic alkylthiol (which may have a thioether structure in the molecule), And thiirane adducts of the alkyl thiols. Or the ester compound which made the compound which has at least 2 hydroxy group among the said alcohol compounds (B-3-1) and the compound of following Chemical formula (II) react is mentioned.

In addition, R ⁴ and R ⁵ in the chemical formula (III) are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aromatic group, and among them, a methyl group or an ethyl group is preferable. More preferably, one of R ⁴ and R ⁵ is a hydrogen atom, and the other is an alkyl group having 1 to 10 carbon atoms (particularly a methyl group or an ethyl group). p is an integer of 0 or more and 2 or less, preferably 0 or 1. q is 0 or 1, preferably 0.

  Specific examples of the compound of the chemical formula (II) include 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-mercaptobutanoic acid, 3-mercaptobutanoic acid, 4-mercaptobutanoic acid, 2-mercaptoisobutanoic acid, 2- Examples include mercaptoisopentanoic acid, 3-mercaptoisopentanoic acid, and 3-mercaptoisohexanoic acid, with 3-mercaptopropionic acid and 3-mercaptobutanoic acid being preferred.

  Examples of the polyfunctional amine compound (B-3-3) include isophorone diamine, 2,2-bis (4-aminophenyl) propane, 2,2-bis (4-aminocyclohexyl) propane, hexamethylene diamine, melamine, and melamine. Derivatives and the like. From the viewpoint of light resistance and hardness of the cured product, isophoronediamine, 2,2-bis (4-aminocyclohexyl) propane, and melamine are preferable.

  Examples of the (meth) acryloyl group-containing isocyanate compound (B-3-4) include 2- (meth) acryloyloxyethyl isocyanate, 3- (meth) acryloyloxypropyl isocyanate, 4- (meth) acryloyloxybutyl isocyanate, 5- (Meth) acryloyloxypentyl isocyanate, 6- (meth) acryloyloxyhexyl isocyanate, 2- (2- (meth) acryloyloxyethyl) oxyethyl isocyanate, 3- (meth) acryloyloxyphenyl isocyanate, 4- (meth) acryloyl Oxyphenyl isocyanate, 1,3-bis ((meth) acryloyloxy) propyl-2-methyl-2-isocyanate, 1,3-bis ((meth) acryloyloxy) propyl-2-isocyanate Doors and the like.

  As the isocyanate compound (B-3-5), in addition to the aforementioned (meth) acryloyl group-containing isocyanate compound (B-3-4), hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate and its Examples thereof include hydrogenated products, xylylene diisocyanate and hydrogenated products thereof, norbornane diisocyanate, and allophanate, dimer (uretdione), and trimer (isocyanurate).

  As the alcohol compound (B-3-6) having a (meth) acryloyl group, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerin di (meth) acrylate, 2-hydroxy-3- (Meth) acryloyloxypropyl (meth) acrylate, 3-hydroxy-2- (meth) acryloyloxypropyl (meth) acrylate, bis ((meth) acryloyloxyethyl) -2-hydroxyethyl isocyanurate, pentaerythritol tri (Meth) acrylate, ditrimethylolpropane tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) acrylate, the aforementioned epoxy (meth) acrylate (B-2), etc. That.

<(3) Polymerization initiator (C)>
The polymerization initiator (C) used in the present invention reacts with the (meth) acryloyl group of the organic-inorganic composite (A) and the (meth) acryloyl group of the polyfunctional (meth) acrylate monomer (B) to form an organic inorganic A copolymer of the composite (A) and the polyfunctional (meth) acrylate monomer (B) can be obtained, and the following polymerization initiators can be exemplified.

  Examples thereof include a photopolymerization initiator that generates radicals by light (ultraviolet light, visible light, etc.) and a thermal polymerization initiator that generates radicals by heat. In addition, when the curing reaction is performed by ionic polymerization, an ionic polymerization initiator (for example, a photoacid generator or a photobase generator) can be used. These polymerization initiators can be used alone or in combination of two or more.

  Examples of the photopolymerization initiator include benzophenone, benzoin methyl ether, benzoin propyl ether, diethoxyacetophenone, 1-hydroxy-phenyl phenyl ketone, 1-hydroxycyclohexyl phenyl ketone (product of BASF; trade name Irgacure 184, etc.), 2, 2-dimethoxy-1,2-diphenylethane-1-one (product of BASF; trade name Irgacure 651, etc.), 2-hydroxy-2-methyl-1-phenylpropan-1-one (product of BASF; trade name Irgacure) 1173), 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (product of BASF; trade name Irgacure 2959, etc.), 2-hydroxy- 1- {4- [4- (2-Hydro Cy-2-methylpropionyl) -benzyl] -phenyl} -2-methylpropan-1-one (BASF product; trade name Irgacure 127 etc.), phenylglyoxylic acid methyl ester (BASF product; trade name Irgacure MBF) 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (product of BASF; trade name Irgacure 907 etc.), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (product of BASF; trade name Irgacure 369, etc.), 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholine-4- Yl-phenyl) -butan-1-one (product of BASF; trade name Irgacure 379, etc.), bis ( , 4,6-trimethylbenzoyl) -phenylphosphine oxide (product of BASF; trade name Irgacure 819 etc.), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (product of BASF; trade name Irgacure TPO etc.), bis (η5 -2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium (product of BASF; trade name Irgacure 784 etc.), 1, 2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] (product of BASF; trade name Irgacure OXE01, etc.), ethanone, 1- [9-ethyl-6- (2- Methylbenzoyl) -9H-carbazol-3-yl] -1,1- (0-acetyloxime (BASF's products; such as Irgacure OXE02), and the like.

  Among these photopolymerization initiators, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide or bis (2 , 4,6-Trimethylbenzoyl) -phenylphosphine oxide, preferably 2-hydroxy-2-methyl-1-phenylpropan-1-one and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide Is most preferred.

These photopolymerization initiators can be used alone or in combination of two or more.
The content of the photopolymerization initiator in the curable composition of the present embodiment is not particularly limited as long as it is an amount capable of appropriately curing the curable composition, and at least 2 with the organic-inorganic composite (A). 5 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the total of the polyfunctional (meth) acrylate monomer (B) having two (meth) acryloyl groups and the second inorganic oxide fine particles (D). It is preferable to mix | blend and it is more preferable to mix | blend 8 mass parts or more and 35 mass parts or less.

If the compounding quantity of a photoinitiator is 5 mass parts or more, hardening of a curable composition will become enough. On the other hand, if it is 40 mass parts or less, the storage stability of a curable composition will not fall and coloring will not easily occur. In addition, problems such as rapid cross-linking during cross-linking to obtain a cured product and cracks during curing are less likely to occur, and there are few outgas components during high-temperature processing, and there is no possibility of contaminating the apparatus.
Examples of the thermal polymerization initiator include peroxide-based and azo-based thermal polymerization initiators. For example, benzoyl oxide, tertiary butyl peroxypivalate, tertiary butyl peroxy-2-ethylhexanoate, 2,2-bisazoisobutyronitrile, dimethyl-2-2′-azobis (2-methylpropyl) (Pionate) etc. are mentioned, but it is not limited to these. Moreover, these thermal polymerization initiators can also be used individually by 1 type, and can also use 2 or more types together.
Content of the thermal polymerization initiator in the curable composition of this embodiment is the same as that of the case of the above-mentioned photoinitiator. Moreover, you may use together a photoinitiator and a thermal-polymerization initiator.

<(4) Second inorganic oxide fine particles (D)>
The second inorganic oxide fine particles (D) used in the curable composition of this embodiment are used for the purpose of improving the refractive index without impairing the curability of the curable composition. Examples of the second inorganic oxide fine particles (D) include silica, hollow silica, alumina, zirconia, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, and antimony. Examples thereof include tin oxide (ATO), cerium oxide, potassium oxide, and composite oxides in which two or more of these are combined. Among these, zirconia is preferable in view of good curability and the viewpoint of particle refractive index, handling, and transparency. When titania is selected as the main component of the first inorganic oxide fine particles (A-2), it is preferable to select zirconia as the main component of the second inorganic oxide fine particles (D). Here, “main component” means that the component accounts for more than 50% by mass.

  Here, a method for measuring the zeta potential of the organic-inorganic composite (A) and the second inorganic oxide fine particles (D) used for the preparation of the curable composition of the present embodiment will be described. The zeta potential was measured using a trade name Zeta Sizer Nano Series ZSP manufactured by Malvern. In measurement, dispersion was diluted to 1% by mass using methyl ethyl ketone (dielectric constant at 20 ° C. was 15.45, viscosity at 20 ° C. was 0.405 mPa · s, and refractive index was 1.380). The liquid was used as a sample.

  Further, preferable conditions for the zeta potential will be described. It is known that as the absolute value of the zeta potential increases, the repulsive force between the fine particles increases and the dispersion stabilizes. When the zeta potential of the organic-inorganic composite (A) and the second inorganic oxide fine particles (D) used for adjusting the curable composition of the present embodiment is measured by the method described above, the organic-inorganic composite (A) When the zeta potential is V1 (mV) and the zeta potential of the second inorganic oxide fine particles (D) is V2 (mV), the ratio V1 / V2 of V1 and V2 is 0.7 <V1 / V2 <1. 5 is satisfied. Furthermore, it is more preferable to satisfy the expression 0.75 <V1 / V2 <1.35, and it is most preferable to satisfy the expression 0.8 <V1 / V2 <1.2. Moreover, it is preferable that both V1 and V2 become -50 (mV) or less, and it is more preferable that it becomes -55 (mV) or less. By using the organic-inorganic composite (A) and the second inorganic oxide fine particles (D) exhibiting the zeta potential, the respective particles can be stably dispersed together.

  As described above, the curable composition of the present embodiment includes the organic-inorganic composite (A), the polyfunctional (meth) acrylate monomer (B), the polymerization initiator (C), and the second inorganic oxide fine particles (D ), But the mass ratio of these components is preferably as follows. That is, the total content of the organic-inorganic composite (A) and the second inorganic oxide fine particles (D) is 100 parts by mass or more and 700 parts by mass with respect to 100 parts by mass of the polyfunctional (meth) acrylate monomer (B). Part or less, preferably 150 parts by mass or more and 500 parts by mass or less, and more preferably 180 parts by mass or more and 350 parts by mass or less.

  In the mixture of these four components, the total content of the organic-inorganic composite (A) and the second inorganic oxide fine particles (D) is 100 masses with respect to 100 mass parts of the polyfunctional (meth) acrylate monomer (B). If it is more than a part, the inorganic content is sufficient, so that a cured product having a predetermined pencil hardness and refractive index can be obtained, and the curing shrinkage is small, and a film-like cured product (“cured film” or “hard coat film” is obtained. In some cases, warping is unlikely to increase. On the other hand, if the amount is 700 parts by mass or less, the influence of the properties of the inorganic oxide fine particles does not appear strongly, so that the film-like cured product has excellent bending resistance, and a self-supporting film can be formed.

Further, the content of the polymerization initiator (C) needs to be 5 parts by mass or more and 40 parts by mass or less, and 8 parts by mass or more and 35 parts by mass with respect to 100 parts by mass of the polyfunctional (meth) acrylate monomer (B). The amount is preferably not more than 11 parts by weight, and more preferably not less than 11 parts by weight and not more than 32 parts by weight.
If the content of the polymerization initiator (C) is 5 parts by mass or more with respect to 100 parts by mass of the polyfunctional (meth) acrylate monomer (B), sufficient properties such as pencil hardness and scratch resistance are obtained by sufficient curing. Become. On the other hand, if it is 40 parts by mass or less, the cured film is hardly warped by the progress of appropriate crosslinking, and the unreacted polymerization initiator (C) hardly remains, so that bleed out or outgas occurs during heating. There is no fear.

  An organic solvent (E) can be mix | blended with the curable composition of this embodiment. The type of the organic solvent is not particularly limited. For example, ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone, esters such as methyl acetate, ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, toluene And aromatic compounds such as xylene. In addition, aliphatic hydrocarbons such as cyclohexane and methylcyclohexane, ethers such as diethyl ether, tetrahydrofuran and propylene glycol monomethyl ether, and alcohols such as methanol, ethanol, isopropanol and butanol can be used. Among these organic solvents, propylene glycol monomethyl ether, methyl ethyl ketone, and methyl isobutyl ketone are preferable.

The ratio of the organic solvent (E) in the curable composition is not particularly limited, and the type of the organic solvent, the property of the curable composition, the type and shape of the target substrate using the curable composition, and the like. Accordingly, it may be set appropriately.
In the present invention, a material that coats the surface of an article (base material) made of various materials such as resin and glass and improves surface performance such as scratch resistance and adhesion is called a hard coat material. The curable composition of this embodiment containing an organic solvent can be used as a hard coat material.

  In addition, the curable composition of the present embodiment may be blended with an additive (F) that imparts desired characteristics to the curable composition or the cured product within a range that does not impair the object and effect of the present invention. . Examples of the additive (F) include photosensitizers, polymerization inhibitors, polymerization initiation assistants, leveling agents, wettability improvers, antifoaming agents, plasticizers, ultraviolet absorbers, antioxidants, and antistatic agents. , Silane coupling agents, pigments, dyes, slip agents, chain transfer agents, and adhesion promoters.

Examples of the photosensitizer include benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, diethyl thioxanthone, isopropyl thioxanthone, and mifiller ketone.
Examples of the adhesion-imparting material include styrene butadiene resin (trade name Septon manufactured by Kuraray Co., Ltd.), vinyl polymer having a polycarbonate skeleton and a urethane bond (trade name Acryt 8UA-347A manufactured by Taisei Fine Chemical Co., Ltd.), 2-methacryloyloxy. Ethyl isocyanate (trade name Karenz MOI manufactured by Showa Denko KK), 2-acryloyloxyethyl isocyanate (trade name Karenz AOI manufactured by Showa Denko KK), pentaerythritol tetrakis (3-mercaptobutyrate) (manufactured by Showa Denko KK) And trade name Karenz MT PE1).

The liquid hard coat material of the present invention is arranged in the form of a film on the surface of a base material of various materials (resin, glass, etc.) by a conventional method such as coating, spraying, or dipping, and the hard coat material is heated or lighted. When the organic solvent is removed by drying or the like, the hard coat film can be coated on the surface of the substrate.
If the curable composition of this embodiment is processed into a film by a conventional method and the curable composition is cured and the organic solvent is removed, a film-like cured product of the curable composition can be obtained. . When the curable composition is a hard coat material, the film-like cured product becomes a hard coat film.

For example, in the case of forming a hard coat film on the surface of the substrate, a hard coat material was applied to the surface of the substrate, and volatile components such as an organic solvent (E) were dried at 10 ° C. or higher and 150 ° C. or lower. Thereafter, if the hard coat material is cured by light, radiation, heat or the like, a molded body coated with the hard coat film can be obtained.
In the case of performing polymerization by heat, for example, an electric heater, an infrared lamp, hot air, or the like can be used as the heat source. The preferable curing conditions when the polymerization is performed by heat are a temperature of 40 ° C. or higher and 150 ° C. or lower and a time of 10 seconds or longer and 24 hours or shorter.

When performing polymerization by radiation (light), the type of radiation (light) is particularly limited as long as the hard coat material can be cured in a short time after coating the hard coat material. However, for example, visible light, ultraviolet light, electron beam, and the like can be given.
Examples of the visible light source include sunlight, a visible light lamp, a fluorescent lamp, and a laser. Furthermore, examples of the ultraviolet ray source include a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, and a laser. Furthermore, as a source of electron beam, a method using thermoelectrons generated from a commercially available tungsten filament, a cold cathode method in which metal is generated through a high voltage pulse, and collision between ionized gaseous molecules and metal electrode The secondary electron system using the secondary electrons generated by the above can be mentioned.

Next, uses of the curable composition, the hard coat material, and the hard coat film of the present embodiment will be described.
The curable composition of the present embodiment is suitable as a hard coat material for use in hard coat films such as coating materials for surface protection (hard coat, clear hard coat) and antireflection films. Examples of the base material to be applied include plastics (polyethylene terephthalate, polycarbonate, polyacrylate, polymethacrylate, polymethyl methacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetyl cellulose, ABS resin (acrylonitrile-butadiene-styrene). Resin), AS resin (acrylonitrile-styrene resin), norbornene resin, cycloolefin polymer (COP resin, etc.), metal, wood, paper, glass, slate, and the like.

  Among these, a polyethylene terephthalate film (PET film) is preferable, and the refractive index of the surface on which the hard coat film of the PET film is formed is preferably 1.60 or more and 1.70 or less, more preferably 1.62 or more and 1.68 or less. 1.635 to 1.665 is most preferable. When the refractive index is 1.60 or more and 1.70 or less, the difference in refractive index from the coating material of the present invention is reduced, so that a PET film giving a good appearance can be obtained.

  The shape of these base materials is not particularly limited, and examples thereof include a plate shape, a film shape, and a three-dimensional molded body. Examples of the hard coating material coating method include ordinary coating methods such as gravure printing, micro gravure printing, inkjet coating, dipping coating, spray coating, flow coating, shower coating, roll coating, spin coating, and brush coating. be able to. The thickness of the coating film in these coatings is the thickness after drying and curing, and is usually 0.1 μm or more and 400 μm or less, preferably 1 μm or more and 200 μm or less.

  The hard coat substrate obtained by forming the hard coat film of the present embodiment on the substrate surface has excellent adhesion between the hard coat film and the substrate surface, has a high surface refractive index, and is light resistant. Excellent in resistance and alkali resistance, and also excellent in scratch resistance. Therefore, index matching film, antireflection film, optical disc, light emitting diode (LED) lighting device, automobile headlamp, automobile body, mobile phone terminal body, solar cell, touch panel, TV receiver, flexible display device, personal computer, etc. Can be applied to. Moreover, it can apply to uses, such as a refractive index adjustment layer of a display panel, a brightness improvement film, and a light extraction layer.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
(1) Synthesis of organic-inorganic composite [Production Example 1]: Preparation of organic-inorganic composite dispersion (L-1) Methanol-dispersed titania fine particles (titania content 30% by mass, titania average particle diameter 13 nm, trade name Opt) 200.0 g of Lake 1130Z (manufactured by JGC Catalysts & Chemicals Co., Ltd.) is placed in a separable flask, and further 18.0 g of 3-acryloyloxypropyltrimethoxysilane (trade name KBM-5103; manufactured by Shin-Etsu Chemical Co., Ltd.) is added. The mixture was stirred and mixed to obtain a uniform solution.

Further, 3.1 g of a 0.18% by mass HCl aqueous solution as a reaction catalyst was added to this mixed liquid, and the titania fine particles were subjected to surface treatment by heating and stirring for 6 hours at an internal temperature of 40 ° C.
Next, the obtained reaction solution was transferred to a flask equipped with a gas inlet, and further 7.8 g of dipentaerythritol hexaacrylate (trade name SARTOMER DPHA; manufactured by SARTOMER), 286.3 g of methyl isobutyl ketone, and polymerization. As an inhibitor, 0.034 g of 2,6-di-t-butyl-p-cresol was added to obtain a uniform solution.

  Next, the temperature inside the flask was heated to 40 ° C., and the system was depressurized while bubbling nitrogen gas containing 5% oxygen into the solution at a rate of 100 mL / min, and the solvent was distilled off. The solvent was distilled off so that the non-volatile content was 30% by mass to obtain 286.1 g of an organic-inorganic composite dispersion (L-1). The zeta potential of the obtained organic-inorganic composite dispersion (L-1) was −57.0 mV.

[Production Example 2]: Preparation of organic-inorganic composite dispersion (L-2) 3-Acroyloxypropyltrimethoxysilane of Production Example 1 was replaced with 3-methacryloyloxypropyltrimethoxysilane (trade name KBM-503; Shin-Etsu). Except for changing to Chemical Industries, Ltd.), the same operation as in Production Example 1 was performed (see Table 1 for the amount of each raw material), and 286.1 g of the organic-inorganic composite dispersion (L-2) was added. Obtained. The zeta potential of the obtained organic-inorganic composite dispersion (L-2) was −56.9 mV.

(2) Preparation of curable composition [Preparation Example 1]: Preparation of curable composition (M-1) 185.9 parts by mass of the organic-inorganic composite dispersion (L-1) obtained in Production Example 1, Dipentaerythritol hexaacrylate (trade name SARTOMER DPHA; manufactured by SARTOMER) 25.5 parts by mass as the polyfunctional (meth) acrylate monomer (B), 1-hydroxycyclohexyl phenyl ketone (trade name Irgacure 184) as the polymerization initiator (C) (IRG184); manufactured by BASF) 4.0 parts by mass, as the second inorganic oxide fine particles (D), zirconia dispersion (trade name Nanouse OZ-S40K-AC; manufactured by Nissan Chemical Industries, Ltd., nonvolatile content 40.0 (Mass%, zeta potential -56.4 mV) 46.8 parts by mass, the non-volatile content, that is, components other than the solvent will be 20 mass% The addition of 257.8 parts by mass of methyl isobutyl ketone to obtain a curable composition (M-1).

[Preparation Examples 2-12]: Preparation of Curable Compositions (M-2) to (M-12) Same as Preparation Example 1, except that the types and amounts used of the respective raw materials were changed as shown in Table 2. Was performed. Good composition liquids were obtained for the curable compositions (M-2) to (M-10), but aggregates were generated for M-11 and M-12, and good composition liquids were obtained. could not.

“PETA” in Table 2 is a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (trade name Aronix M-306; manufactured by Toagosei Co., Ltd.), and “UN-3320HA” is a hexafunctional urethane acrylate. (Trade name UN-3320HA; manufactured by Negami Kogyo Co., Ltd.).
“IRG1173” in Table 2 is 2-hydroxy-2-methyl-1-phenylpropan-1-one (trade name Irgacure 1173; manufactured by BASF), and “IRG TPO” is 2, 4, 6-trimethylbenzoyldiphenylphosphine oxide (trade name Irgacure TPO; manufactured by BASF).

Furthermore, “OPTOLAKE” in Table 2 is a zirconia dispersion (trade name OPTOLAKE 256Z1) manufactured by JGC Catalysts and Chemicals Co., Ltd., having a nonvolatile content of 21.5% by mass and a zeta potential of −57.0 mV.
Further, “Zirconia A” in Table 2 is a zirconia dispersion having a nonvolatile content of 13.0 mass% and a zeta potential of −22.2 mV, and “Zirconia B” has a nonvolatile content of 32.7 mass%, This is a zirconia dispersion having a zeta potential of −36.1 mV.

(3) Production and evaluation of coating film [Example 1]
The curable composition (M-1) is applied onto the easy-adhesion surface of a 125 μm-thick PET film (trade name Lumirror UH-13; manufactured by Toray Industries, Inc.) so that the thickness of the dried coating film becomes 1 μm. And dried at 100 ° C. for 1 minute. Next, using a conveyor exposure machine, UV light (200 mJ / cm ² ) is irradiated with a UV lamp (high pressure mercury) under a nitrogen atmosphere, and the curable composition (M-1) is cured to cure. A PET film (hereinafter referred to as “coating film”) coated with a cured product (hard coat film) of the composition (M-1) was obtained. The obtained coating film was used for the test of the adhesiveness, light resistance, and alkali resistance according to the below-mentioned evaluation method. The results are shown in Table 3.

In addition, the curable composition (M-1) of a PET film (trade name Cosmo Shine (trademark) A-4100; manufactured by Toyobo Co., Ltd.) having a thickness of 125 μm is used so that the thickness of the dry coating film becomes 30 μm. It apply | coated on the easily bonding surface and was dried at 100 degreeC for 1 minute. Next, using a conveyor exposure machine, UV light (200 mJ / cm ² ) is irradiated with a UV lamp (high pressure mercury) under a nitrogen atmosphere, and the curable composition (M-1) is cured to cure. A coating film coated with a cured product (hard coat film) of the composition (M-1) was obtained. The obtained coating film was subjected to a refractive index test according to the evaluation method described later. The results are shown in Table 3.

[Examples 2 to 9 and Comparative Examples 1 to 3]
A coating film was obtained in the same manner as in Example 1 except that the curable composition (M-1) was changed to curable compositions (M-2) to (M-12), respectively. In the same manner as in Example 1, it was subjected to various tests. The results are shown in Table 3.

(4) Evaluation method of coating film [Evaluation of adhesion]
A cross-cut guide (manufactured by Cortec Co., Ltd.) was placed on the coating film, and the hard coat film of the coating film was cut into squares using a cutter knife or the like. One square was 2 mm square in length and width, and was cut so that a total of 100 squares were formed by 10 squares and 10 squares.

An adhesive tape (Cellotape (registered trademark) manufactured by Nichiban Co., Ltd.) was applied to the cut hard coat film, and after sufficiently adhering, the adhesive tape was peeled off from the hard coat film. And the peeling condition from the base material (PET film) of a hard-coat film | membrane was observed visually, and the following reference | standard evaluated.
A: No peeling from the substrate B: Not all peeling, but some peeling is observed.
C: The whole surface peeled from the substrate

[Evaluation of refractive index]
The refractive index of the hard coat film of the coating film was measured using an Abbe refractometer (DR-M4 manufactured by Atago Co., Ltd.).
[Evaluation of light resistance]
Using a compact black light blue fluorescent lamp (FPL27BLB manufactured by Sankyo Electric Co., Ltd.), the coating film was irradiated with ultraviolet rays for 200 hours. And the adhesiveness evaluation was performed by the method similar to the above with respect to the coating film after irradiation.

[Evaluation of alkali resistance]
The coating film was immersed for 10 minutes in a 5% by weight sodium hydroxide aqueous solution kept at 40 ° C., and the change in the appearance of the hard coat film after the immersion was visually confirmed. And the adhesiveness evaluation was performed by the method similar to the above with respect to the coating film after immersion.

  Table 3 shows the results of these various tests. In Comparative Examples 2 and 3, a dispersion could not be obtained due to aggregation between inorganic oxide fine particles. Examples 1 to 9 are excellent in initial adhesion (adhesion before being subjected to a light resistance test or an alkali resistance test) and are not obtained in Comparative Example 1 even after the light resistance test or after the alkali resistance test. Excellent adhesion was obtained. From these results, good adhesion is obtained by appropriately selecting the zeta potential of the first and second inorganic oxide fine particles to be used and using two kinds of inorganic oxide fine particles in combination. I understand. Moreover, it turns out that Examples 1-9 are excellent in light resistance and alkali resistance.

Claims (5)

An organic-inorganic composite (A) in which a silane coupling agent having a (meth) acryloyl group and an alkoxysilyl group and the first inorganic oxide fine particles are bonded;
A polyfunctional (meth) acrylate monomer (B) having at least two (meth) acryloyl groups;
A polymerization initiator (C);
Second inorganic oxide fine particles (D) which are different types of inorganic oxide fine particles from the first inorganic oxide fine particles;
Containing
When the content of the polyfunctional (meth) acrylate monomer (B) having at least two (meth) acryloyl groups is 100 parts by mass, the organic-inorganic composite (A) and the second inorganic oxide fine particles ( D) is 100 parts by mass or more and 700 parts by mass or less, and the content of the polymerization initiator (C) is 5 parts by mass or more and 40 parts by mass or less,
When the zeta potential of the organic-inorganic composite (A) is V1 (mV) and the zeta potential of the second inorganic oxide fine particles (D) is V2 (mV), the ratio V1 / V2 of V1 and V2 is A curable composition satisfying the formula 0.7 <V1 / V2 <1.5, and V1 and V2 are both -50 (mV) or less.   The curable composition according to claim 1, wherein the first inorganic oxide fine particles are mainly composed of titania, and the second inorganic oxide fine particles (D) are mainly composed of zirconia.   A cured product obtained by curing the curable composition according to claim 1.   A hard coat material comprising the curable composition according to claim 1 or 2.   A hard coat film formed by arranging the hard coat material according to claim 4 on the surface of a base material in a film shape and curing it.