JPH07247306A - Ultraviolet-curable composition - Google Patents

Abstract

PURPOSE:To obtain an ultraviolet-curable compsn. which cures easily to give a cured film having a high refractive index, an excellent clarity, etc., by incorporating a specific fine metal oxide power into a specific (meth)acrylate monomer mixture. CONSTITUTION:An ultraviolet-curable compsn. is prepd. by compounding 100 pts.wt. (meth)acrylate monomer mixture contg. 5-40wt.% biphenylene-group-contg. difunctional acrylate monomer of the formula: R1-C6H4-C6H4-R2 {wherein R1 and R2 are each -O-(CH2CH2O)m-COCH=CH2 (wherein m is 0-3), -O-(CH2CH (OH)CH2O)n-COCH=CH2 (wherein n is 1-3), or -COO-(CH2CH2O)p-COCH=CH2 (wherein p is 1-3)} with 10-200 pts.wt. fine metal oxide powder having an average particle size of 1-50nm and comprising titanium oxide and ferric oxide in a wt. ratio of TiO2/Fe2O3 of 20-99. The compsn. gives an ultraviolet-cured film having a refractive index of 1.54-1.70.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a UV-curable composition, and more specifically, it is easily cured by being irradiated with UV rays after being applied to a resin molding, and has a high refractive index, transparency, and
The present invention relates to an ultraviolet curable composition capable of forming a cured film having excellent scratch resistance, chemical resistance, adhesion to a resinous molded article, and the like.

[0002]

2. Description of the Related Art In recent years, synthetic resin products have been widely used for optical products such as spectacle lenses and optical lenses mounted on optical equipment. However, since the surface of the optical product made of synthetic resin is soft, it is easily scratched by sand or dust. The decrease in light transmittance due to these scratches is a fatal problem for optical products. Therefore, in optical products such as synthetic resin lenses, it is necessary to form a cured film having scratch resistance on the surface for protection.

This cured film is formed by applying a liquid composition mainly containing a curing agent to the surface of an optical product and curing it. Conventionally, as a curing agent applied to these synthetic resin optical products, a silicon-based thermosetting curing agent (see JP-A-59-102964) is the mainstream, and this type of curing agent is It can be easily applied by the dipping method, and an extremely hard cured film is formed by heating. However, a cured film formed of a silicon-based curing agent is generally inferior in chemical resistance, particularly alkali resistance. Further, with the demand for higher refractive index of synthetic resin lenses such as spectacle lenses, it is required that the cured film formed on the surface thereof also has a high refractive index. However, the cured film made of the above-mentioned silicon-based curing agent does not have a sufficiently high refractive index. Then, when the difference in the refractive index between the synthetic resin lens that is the base material of the optical product and the cured film becomes large,
Interference fringes of light appear, making the appearance unsightly, which is not practical.

As a cured film having a high refractive index, a film comprising a specific organic silicon compound, cerium oxide fine particles and silica fine particles is known (Japanese Patent Laid-Open No. 63-2237).
No. 01). However, such a cured film is easily yellowed by the cerium oxide fine particles contained for increasing the refractive index, and the hardness of the cured film is low and the scratch resistance is insufficient.

Further, it has been described in JP-A-2-77434 that the titanium dioxide fine particles are used to increase the refractive index, but the cured film may turn black with time due to light resistance deterioration. Further, it is known that the combined use of titanium dioxide and ferric oxide (JP-A-2-178219) enhances the ultraviolet shielding effect and further improves the light resistance. However, a cured film composed of these UV-curable paints and compositions is based on the volume shrinkage during film formation,
Adhesion to the synthetic resin base material is still insufficient. Further, the cured film from these ultraviolet curable coating compositions,
In addition, when forming a metal thin film by a vacuum vapor deposition method or the like, there is a drawback that the adhesion to the metal thin film is poor.

[0006] As described above, curing which is easily cured by irradiation of ultraviolet rays, has a high refractive index, and is well balanced in scratch resistance, chemical resistance, light resistance, and adhesion to a synthetic resin substrate. A cured film composition capable of forming a film has not yet existed, and its development is strongly desired.

[0007]

The present invention has been made based on the above circumstances, and its purpose is to:
Can be easily cured by UV irradiation to form a cured film having a high refractive index, excellent transparency, scratch resistance, chemical resistance, light resistance, and adhesion to a synthetic resin substrate. An object is to provide an ultraviolet curable composition.

[0008]

The ultraviolet-curable composition of the present invention has a biphenylene group represented by the following chemical formula 2
100 parts by weight of a (meth) acrylate-based monomer mixture containing 5 to 40% by weight of a functional acrylate-based monomer, having an average particle size of 1 to 50 nm, and composed of titanium dioxide and ferric oxide. , Its mixing ratio (TiO ₂ / Fe ₂ O
₁ : ₃ metal oxide fine particles having a weight ratio of ₃ to 20 are 99.
It is contained in an amount of 0 to 200 parts by weight and forms a cured film by irradiation of ultraviolet rays, and the cured film has a refractive index of 1.54 to 1.70.
Is characterized in that.

Embedded image R ₁ —C ₆ H ₄ —C ₆ H ₄ —R _{2 In} Chemical Formula ₂ , R ₁ and R ₂ are —O— (CH ₂ CH ₂ O) _m —COCH═CH ₂ (where m is Or an —O— (CH ₂ C (OH) HCH ₂ O) _n —COCH═C.
H ₂ (where, n is an integer of 1-3.) _{Or, -COO- (CH 2 CH 2 O} ) p -COCH = CH 2 ( Here, p is an integer of 1-3.) Shows the , And may be the same or different.

The present invention will be described in detail below. The ultraviolet-curable composition of the present invention has a biphenylene group-containing 2
An acrylate-based monomer mixture containing a functional acrylate-based monomer (hereinafter also referred to as “biphenylene-based monomer”) as essential components and metal oxide fine particles.

Since the biphenylene-based monomer itself has a high refractive index and a small volume shrinkage during polymerization, a composition with a polyfunctional acrylate-based monomer has a refractive index The cured film is high and has excellent adhesion to the base material made of synthetic resin or the metal film on the cured film, and has good appearance without interference fringes.

The biphenylene type monomer represented by the chemical formula 2 is
The molecule has two substituents in which an acryloyloxy group is bonded to the following "ethoxy group", "hydroxypropoxy group" or "ethoxycarbonyl group". The two substituents may be different from each other, but it is easy to enhance the curing reactivity of the ultraviolet curable composition of the present invention and to improve the scratch resistance and chemical resistance of the resulting cured film. Therefore, it is preferable that R ₁ and R ₂ are the same substituents (the repeating numbers m, n and p are also the same). Also, the substitution position of the substituent to the biphenylene nucleus may be present in a large number by various combinations, but the volume shrinkage during the curing reaction is significantly reduced, and the resulting cured film is used for the synthetic resin substrate lens. The position of "2,2'-" of the biphenylene nucleus is more preferable because the adhesion is further improved.

_{[0012]: -O- (CH 2 CH 2 O} ) m -COCH = CH 2 ( where, m: 0 to 3 _{integer): -O- (CH 2 C (} OH) HCH 2 O) n -COCH =
CH ₂ (where, n: 1 to 3 _{integer): -COO- (CH 2 CH 2} O) p -COCH = CH 2 ( where, p: 1 to 3 integer)

When m, n, and p representing the number of repetitions become large, the adhesion of the formed cured film to the base resin improves, but the hardness, refractive index, transparency, etc. of the cured film tend to decrease. However, the performance balance of the cured film is best when m is 0 and n and p are 1 respectively. When a bifunctional acrylate in which two acryloyloxy groups are bound to these biphenylene groups is mixed with other polyfunctional (meth) acrylate and used, the hardness and scratch resistance of the cured film formed are increased, and , These mixed monomers have a small volume shrinkage rate at the time of forming a cured film, further improve adhesion with a synthetic resin base material, appearance characteristics and transparency,
It is easy to obtain a cured film which is excellent in flexibility and has a good performance balance without interference fringes.

Next, as the polyfunctional (meth) acrylate used by mixing with the biphenylene-based monomer, first, as other bifunctional (meth) acrylate, 1,3-butanediol di (meth) is used. Acrylate,
1,6-hexanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane benzoate diacrylate, bisphenol A diglycidyl ether diacrylate, tolylene diisocyanate and hexa Urethane-based oligodi (meth) acrylate obtained by reacting polyisocyanate such as methylene diisocyanate with 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate or 2-hydroxyethyl (meth) acrylate And so on. Among these bifunctional (meth) acrylates, urethane-based oligodi (meth) acrylates have excellent adhesiveness to the resin-made base material and have good flexibility, and therefore, the cured film of the film surface It is also effective in preventing cracks.

Next, as other polyfunctional (meth) acrylate monomers, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa Polyurethane such as (meth) acrylic acid ester of polyhydric alcohol such as (meth) acrylate, tolylene diisocyanate, hexamethylene diisocyanate and urethane type urethane obtained by reaction with glycerin dimethacrylate, pentaerythritol tri (meth) acrylate Examples thereof include oligo (meth) acrylate. Here, the oligo (meth) acrylate refers to an oligomer having a (meth) acryloyloxy group at the molecular end or side chain and having a molecular weight of several hundreds to several thousands.

In the ultraviolet curable composition of the present invention,
The content ratio of the biphenylene-based monomer in the acrylate-based monomer mixture is 5 to 40% by weight, preferably 6 to 3%.
It is 7% by weight, more preferably 7 to 35% by weight. If this proportion exceeds 40% by weight, the hardness and scratch resistance of the obtained cured film will decrease. On the other hand, when this value is less than 5% by weight, the volume shrinkage during the formation of the cured film becomes large, the adhesion to the synthetic resin substrate decreases, and the refractive index also decreases, resulting in poor appearance of the cured film. It is not preferable because it causes damage.

Next, in the ultraviolet-curable composition of the present invention, a metal composed of titanium dioxide and ferric oxide is used mainly for the purpose of increasing the refractive index of the formed cured film and reducing the light-resistant discoloration of the cured film. The oxide fine particles are the second essential constituent component. Further, the metal oxide fine particles also have an effect of enhancing the adhesiveness with the metal thin film when the metal thin film is formed on the cured film by the vacuum deposition method or the sputtering method. The mixing ratio of titanium dioxide and ferric oxide in the metal oxide fine particles (TiO ₂ / F
e ₂ O ₃ ) is in a weight ratio of 20 to 99, preferably 35 to 50.
Is. Further, the particle size is 1 to 50 nm, preferably 5 to
40 nm.

The mixing ratio of titanium dioxide and ferric oxide is 20.
When the amount is less than the above, the stability of the metal oxide fine particles as a sol decreases. In addition, the curing reaction of the acrylate-based monomer mixture with ultraviolet energy tends to be inhibited. Further, reddish brown coloring due to ferric oxide becomes strong, and it becomes difficult to obtain a colorless and transparent cured film. On the other hand, when the mixing ratio exceeds 99 and becomes large, the light resistance of the cured film against discoloration becomes strong, and the cured film becomes blackish. If the particle size is less than 1 nm, it becomes difficult to use the metal oxide fine particles in a stable sol state, and the performance also tends to deteriorate the refractive index and scratch resistance, which is not preferable in the performance of the cured film. . However, when the particle size exceeds 50 nm and becomes large, the transparency of the cured film decreases, which is also not preferable.

The metal oxide fine particles can be obtained as a colloidal liquid dispersed in various media, but an organic solvent excellent in compatibility with polyfunctional acrylates, particularly biphenylene-based monomers, such as methyl. alcohol,
It is preferable to use a dispersion medium such as ethyl alcohol or isopropyl alcohol. A preferred specific example of such a metal oxide fine particle sol is “Optlake 1120F” manufactured by Catalysts & Chemicals Industry Co., Ltd. Incidentally, the surface of the metal oxide fine particles may be subjected to a lipophilic treatment or the dispersibility of the metal oxide fine particles in the metal oxide fine particle sol may be increased by adding carboxylic acid, amine or the like to the fine particle sol. it can. As a result, the dispersibility of the fine particles in the composition of the present invention is enhanced.

The amount of the fine metal oxide particles blended is 10 to 200 parts by weight, preferably 15 to 150 parts by weight, per 100 parts by weight of the acrylate-based monomer mixture. If the blending amount is less than 10 parts by weight, the refractive index of the cured film cannot be sufficiently increased, and the refractive index difference between the lens substrate having a high refractive index and the cured film should be adjusted within ± 0.05. Becomes difficult. In addition, the adhesiveness is reduced due to the volume contraction during the formation of the cured film, and when the metal thin film such as the antireflection film is further formed on the cured film, the adhesion between the cured film and the metal thin film is insufficient. Become. On the other hand, if the blending amount exceeds 200 parts by weight, the transparency of the formed cured film will decrease. Further, there is a tendency that the curing reactivity is lowered and the scratch resistance of the cured film is lowered.

When preparing the curable composition of the present invention, an organic solvent excellent in compatibility with the dispersion medium of these metal oxide fine particles and the polyfunctional acrylate can be used if necessary. For example, benzene, toluene,
Aromatic hydrocarbons such as xylene, aliphatic saturated hydrocarbon alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol, aliphatic ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and butyl acetate, and ethyl. Specific examples include ethers such as cellosolve. These organic solvents can be used singly or in a mixture of two or more kinds, and among them, methyl alcohol or ethyl alcohol which is an aliphatic saturated hydrocarbon lower alcohol, and methyl ethyl ketone which is an aliphatic ketone are preferably used. . By using these organic solvents, it becomes easy to enhance the uniformity of dispersion of the metal oxide fine particles in the curable composition of the present invention.

In the curable composition of the present invention, it is desirable to use a photopolymerization initiator or a photosensitizer in order to accelerate the curing reaction by ultraviolet irradiation. Specific examples of such photopolymerization initiators and photosensitizers include benzoin such as 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-4'-isopropyl-2-methylpropiophenone, 2-hydroxy-2-methylpropiophenone, and benzoin methyl ether. Ethers, 3,3'-dimethyl-4
-Benzophenones such as methoxybenzophenone, 2,
Examples thereof include xanthones such as 4-diethylthioxanthone and 2-chlorothioxanthone, and acetophenone derivatives. Diluted with a lower alcohol as a dispersion medium forming the metal oxide fine particle sol or the ultraviolet curable composition of the present invention. Compounds that are easily uniformly dissolved in an organic solvent used as an agent or a viscosity modifier, for example, 1-hydroxycyclohexyl phenyl ketone having 2-hydroxy group, 2-hydroxy-4'-isopropyl-2-methylpropiophenone, 2-hydroxy-2-methylpropio Phenone and the like are more preferable.

The content of these photosensitizers is 0.1 to 10 parts by weight, preferably 0.1 to 7 parts by weight, based on 100 parts by weight of the acrylate-based monomer mixture. If the amount is less than 0.1 part by weight, the curing reaction will not proceed sufficiently and
If it is used in an amount of more than 0 parts by weight, the cured film will be colored and the light resistance will decrease, such being undesirable.

The ultraviolet-curable composition of the present invention contains, if necessary, a light stabilizer, an antioxidant, a storage stabilizer, a colorant, a plasticizer, an antistatic agent as long as the object of the present invention is not impaired. A silicon-based or fluorine-based surface smoothing agent or the like can be added.

The UV-curable composition of the present invention is applied to the surface of a synthetic resin substrate which is an optical product, and is cured by UV irradiation to form a cured film. The synthetic resin substrate on which the cured film is formed has a difference in refractive index of the cured film of ± 0.05 or less, particularly preferably ± 0.0
There is no particular limitation as long as it is within 4. When the difference in refractive index exceeds ± 0.05, interference fringes are formed on the cured film and the appearance is unsightly, which is not preferable.

The synthetic resin as the base material is transparent,
If the refractive index is within the above range, it is not particularly limited, but a urethane resin that is a cross-linked polymer composed of a compound having an isocyanate group or a modified urethane resin that contains a sulfur atom in its molecule, A cross-linked (co) polymer of a monomer having an aromatic group or a halogen atom-substituted aromatic group has a high refractive index, is excellent in hardness, heat resistance and impact resistance, and is a synthetic resin base. It is particularly preferable because the material can be easily obtained.

The method for forming a cured film on the surface of a synthetic resin substrate is not particularly limited, but one mode of a preferable forming method will be shown below. First, the surface of the synthetic resin base material is chemically treated with an acid or alkali aqueous solution, for example, a sulfuric acid-chromic acid mixed solution or a 20% sodium hydroxide aqueous solution, or a corona discharge treatment, a low temperature plasma treatment, ultraviolet rays or ozone is used. Wash by performing treatment. Next, the ultraviolet curable composition of the present invention is applied onto the resin base material by a dipping method, a spinner method or the like, and then volatile components such as an organic solvent are dried and removed. Then, the coated curable composition is irradiated with ultraviolet rays having a wavelength of 180 to 400 nm at a room temperature of 30 to 40 ° C. or lower for 1 second to 60 seconds by using a high pressure mercury lamp or the like to cure and cure the composition. Form a film.

The thickness of the cured film thus formed is 500 to 10000 nm, more preferably 1000 to 5 nm.
000 nm. If the thickness is less than 500 nm, the scratch resistance is poor, and if it exceeds 10,000 nm, the film thickness is not uniform, and the film performance such as hardness, scratch resistance, and chemical resistance varies. Can not be achieved.

The cured film formed from the ultraviolet curable composition of the present invention has a refractive index of 1.54 or more, preferably 1.58 or more. As a result, even when formed on a synthetic resin base material having a high refractive index, appearance defects due to light interference fringes hardly occur.

[0030]

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited thereto. In the following examples and comparative examples,
"%" And "parts" represent "wt%" and "parts by weight", respectively.

As the "biphenylene type monomer", the following were used. The substitution positions of the substituents R ₁ and R _{2 to} the biphenylene group are both “2,2′-”. R-1: The substituents R ₁ and R ₂ in the above Chemical formula ₂ are —OCOCH.
= Is a CH ₂ (m = 0). R-2: The substituents R ₁ and R _{2 in the} chemical formula ₂ are —O (CH ₂
CH ₂ O) ₃ COCH = CH ₂ (m = 3). R-3: The substituents R ₁ and R _{2 in the} above Chemical formula ₂ are —OCH ₂ C.
H (OH) is a _{CH 2 OCO-CH = CH 2} (n =
1). R-4: The substituents R ₁ and R ₂ in the chemical formula ₂ are —COOCH.
₂ CH ₂ OCOCH = CH ₂ (p = 1). R-5: The substituents R ₁ and R _{2 in the} chemical formula ₂ are —O (CH ₂
CH ₂ O) ₅ COCH = CH ₂ (m = 5). R-6: The substituents R ₁ and R _{2 in the} chemical formula ₂ are —O {CH ₂
CH (OH) CH ₂ O} is a ₅ -COCH = CH ₂ (n
= 5). R-7: The substituents R ₁ and R _{2 in the} above Chemical formula ₂ are —COO (C
_{H 2 CH 2 O) 5 COCH} = a CH ₂ (p = 5).

Example 1 Biphenylene monomer (R-
1) 14 parts, 81 parts of pentaerythritol triacrylate ("PE-3A": manufactured by Kyoeisha Chemical Co., Ltd.), and acrylate urethane oligomer ("AT-600":
121.8 parts of methyl ethyl ketone in 100.6 parts of an acrylate-based monomer mixture consisting of 5.6 parts (manufactured by Kyoeisha Chemical Co., Ltd.) (5.0 parts of the active ingredient, and hereinafter shown as the amount of the active ingredient). And mixed with titanium dioxide and ferric oxide (solid content concentration 20%, solid content mixing weight ratio: TiO 2) as a metal oxide fine particle sol.
_{2 / Fe 2 O 3 = 98} /2) methanol dispersion sol consisting of "Optolake 1120F" (Shokubai Kasei Co., Ltd.: average particle diameter: 10 to 20 nm) 325 parts (solid content: 65 parts) were mixed. The total concentration of the active ingredient of the acrylate-based monomer and the solid content of the metal oxide fine particles in this mixed solution was about 30%. Furthermore, 2 parts of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator and 0.6 part of a silicon-based surface smoothing agent were added to this mixed solution, and the mixture was sufficiently stirred and mixed to obtain the ultraviolet curable composition of the present invention. Obtained.

The performance of this composition was evaluated by the following method, and the results are shown in Table 1. <Coating on concave lens> As a lens substrate, the refractive index of the cross-linked copolymer of m-xylylene diisocyanate and di (2-mercaptoethyl) ether is n _D = 1.62.
Concave lens (Mitsui Toatsu: center thickness 1.2 mm, diameter 75
mm) was used. First, this lens at 1
Annealing was carried out for a period of time, and then the lens surface was degreased by immersing in a 5% sodium hydroxide aqueous solution at 60 ° C. for 10 minutes, then washed with water, further ultrasonically washed in ultrapure water, and then dried with hot air. Next, this treated lens is dipped in the above-mentioned UV curable composition liquid for 5 seconds, then pulled out of the immersion liquid at a rate of 300 mm / min, air-dried at room temperature, and further preliminarily cured at 60 ° C. for about 5 minutes. Then, a pre-cured film of the composition was formed on the lens surface.

<Formation of cured film> An ultraviolet irradiation device "MiniCure System UV-450" (manufactured by Ushio Inc.) using a high pressure mercury lamp with an output of 500 W as a source was used.
The pre-cured film was irradiated with ultraviolet rays for 20 seconds to be cured to form a cured film on the lens.

<Evaluation of cured film> The performance of the obtained cured film was evaluated by the following method. (A) Appearance test (1) Interference fringes The reflected light under a fluorescent lamp "Mellow Look FL15EX-S" (manufactured by Toshiba Corporation) was visually observed, and the appearance was evaluated according to the following criteria. ◯: No interference fringes are visible. Δ: Interference fringes are slightly visible. X: Strong interference fringes are clearly visible. (2) Transparency and color tone Using the same fluorescent lamp as in (1) above, about 1
The transmitted light at a position separated by 0 cm was visually observed and evaluated according to the following criteria. ◯: No cloudiness or cloudiness. Δ: There is a slight cloudiness. X: There is opaque white turbidity on the entire surface.

(B) Scratch resistance test # 00 was applied to the surface of the cured film while applying a load of 1000 g.
Rubbing with 00 steel wool 10 times, the presence or absence of scratches and the degree of scratches were visually observed, and evaluated according to the following criteria. The ○ mark was passed. ◯: Almost no scratch was observed. Δ: Some scratches are recognized. X: Many scratches are recognized.

(C) Adhesion test for substrate (concave lens) The cured film on the substrate was vertically cut at 1 mm intervals using a cutter.
Make 11 lines each with 11 horizontal cuts to make 100 bangs. Adhesive tape "Big Eco" (Sekisui Co., Ltd.)
Peeling test was carried out by using a product manufactured by K.K.) to examine the number of peeled burrs and evaluated according to the following criteria. ◯: No peeling is observed. (Triangle | delta): 1-5 peeling is seen. X: 10 or more peelings are seen.

(D) Weather resistance test Xenon lamp weatherometer (manufactured by Toyo Seiki Co., Ltd .:
Irradiation was performed for 300 hours using "Atlas CI35W", and the appearance after irradiation was evaluated by the test method of (2) of (a) above. The criteria for judgment are as follows. ◯: Turbidity and cracks are not seen at all. Δ: Some white turbidity or slight cracks are seen. X: The entire surface is opaque or strong cracks are seen.

(E) Measurement of Refractive Index A solution of each composition was spinner-coated on a silicon wafer and measured using “Ellipsometry AEP-100” (manufactured by Shimadzu: helium-neon laser beam is irradiated from a light source). .

[Examples 2 and 3 and Comparative Examples 1 and 2] The compounding amount of the biphenylene monomer (R-1) was 1 part (Comparative Example 1), 9 parts (Example 2), 35 parts (Example). Example 3) and 52
Parts (Comparative Example 2) with 93 parts of pentaerythritol triacrylate (“PE-3A”) and 8 parts, respectively.
In 6 parts, 61 parts and 45 parts, the compounding amount of the acrylate urethane oligomer (“AT-600”) was changed to 6 parts (Comparative Example 1), 4 parts (Example 3) and 3 parts (Comparative Example 2). An ultraviolet curable composition was obtained in the same manner as in Example 1 except for the above. The evaluation results of the performance are shown in Table 1.

[Examples 4 to 5] The type and blending amount of the biphenylene type monomer were 25 parts of R-3 (Example 4) and R-4.
12 parts (Example 5) of 71 parts (Example 4) and 83 parts (Example 5) of pentaerythritol triacrylate (“PE-3A”), and an acrylate urethane oligomer (“AT- A UV-curable composition was obtained in the same manner as in Example 1 except that the compounding amount of "600") was changed to 4 parts (Example 4). The evaluation results of the performance are shown in Table 1.

[Example 6 and Comparative Examples 3 to 5] The types of the biphenylene-based monomers are R-2 (Example 6), R-5 (Comparative Example 3), R-6 (Comparative Example 4) and R. An ultraviolet curable composition was obtained in the same manner as in Example 1 except that the composition was changed to -7 (Comparative Example 5). The evaluation results of the performance are shown in Table 1.

Example 7 81 parts of pentaerythritol triacrylate (“PE-3A”) and 5 parts of acrylate urethane oligomer (“AT-600”) were added to methacrylate urethane oligomer (“UA-101H”:
Kyoeisha Chemical Co., Ltd. 26 parts and acrylate urethane oligomer (“UA-306T”: Kyoeisha Chemical Co., Ltd.)
The UV curable composition of the present invention was obtained in the same manner as in Example 1 except that the amount was changed to 60 parts. The performance is shown in Table 1. The ultraviolet irradiation time for forming the cured film was 50 seconds.

Example 8 A biphenylene-based monomer was used as R-
4 to 12 parts, pentaerythritol triacrylate (“PE-3A”) to 71 parts, and acrylate urethane oligomer (“AT-600”) to acrylate benzoate ester (“BA-134”: Kyoeisha Chemical Co., Ltd. )) Was obtained in the same manner as in Example 1 except that the ultraviolet curable composition of the present invention was obtained. The performance is shown in Table 1.
It was shown to.

[Examples 9 to 10 and Comparative Examples 6 to 7] 90 parts (solid content: 18 parts) (Example 9) and 725 parts (solid content) of the metal oxide fine particle sol "Optlake 1120F" were compounded. 145 parts) (Example 10), 15 parts (solid content: 3 parts) (Comparative Example 6) and 1150 parts (solid content: 23).
0 parts) (Comparative Example 7), and 121.8 parts of methyl ethyl ketone as a diluent was added to 1 part of methyl ethyl ketone.
To 200 parts of a mixed solvent of 50 parts and 50 parts of methyl alcohol (Example 9), 397 parts of a mixed solvent of 200 parts of methyl ethyl ketone and 197 parts of methyl alcohol (Comparative Example 6).
An ultraviolet curable composition was obtained in the same manner as in Example 1 except that the composition was changed to. The solid content concentration in the composition of Comparative Example 7 was about 26.
%Met. Others were about 30% like Example 1. The results of performance evaluation are shown in Table 1.

[Comparative Example 8] "Optlake 1120F"
325 parts (solid content 65 parts) of isopropanol-dispersed sol of titanium dioxide fine particles "OSCAL 842" (manufactured by Catalysts & Chemicals Co., Ltd .: solid content concentration 20.5%, particle diameter 20)
(30 nm) to 317.1 parts and an ultraviolet curable composition was obtained in the same manner as in Example 1 except that the compounding amount of methyl ethyl ketone was changed to 129.8 parts. Table 1 shows the results of performance evaluation.
It was shown to.

[Comparative Example 9] "Optlake 1120F"
325 parts of methanol-dispersed sol "Quintitanic" (manufactured by Catalysts & Chemicals Co., Ltd .: solid content concentration 20%, in which the mixing ratio of titanium dioxide and ferric oxide (TiO ₂ / Fe ₂ O ₃ ) is 4) A UV-curable composition was obtained in the same manner as in Example 1 except that the particle size was changed to 325 parts. The results of performance evaluation are shown in Table 1.

[Comparative Example 10] "Optlake 1120
90 parts of "F" is a methanol dispersion sol of "Titanium dioxide fine particles alone""Quin Titanic special product" (Catalyst Kasei Co., Ltd .: solid content concentration 20%, average particle diameter 61 nm) 9
Change to 0 parts and add 160.5% methanol as diluent.
Parts and methyl ethyl ketone to 40.1 parts to obtain an ultraviolet curable composition in the same manner as in Example 9. The results of performance evaluation are shown in Table 1.

[0049]

[Table 1] Note) “---” mark: Impossible to measure due to poor transparency

[0050]

As described above, a mixture of a (meth) acrylate monomer containing a bifunctional acrylate monomer having a specific biphenylene group as an essential component, titanium dioxide and ferric oxide. The ultraviolet curable composition of the present invention containing fine oxide particles, a synthetic resin optical product, for example, optical lenses such as cameras, microscopes, telescopes, binoculars, sunglasses, spectacle lenses such as correction lenses. Alternatively, by applying it to a prism, a reflecting mirror or the like, and further, to a synthetic resin substrate such as a cover glass for a watch or a decorative case and curing it by ultraviolet irradiation, the refractive index is high, the scratch resistance and the abrasion resistance are high. It is possible to form a cured film which is excellent in chemical properties, adhesiveness and the like, and which does not cause interference fringes and has a good appearance. Further, since the cured film formed by the ultraviolet curable composition of the present invention has excellent adhesion to a metal thin film, it is possible to easily form an antireflection film or a reflection increasing film on the cured film. it can.

Claims (1)

[Claims] 1. An average particle diameter based on 100 parts by weight of a (meth) acrylate-based monomer mixture containing 5 to 40% by weight of a bifunctional acrylate-based monomer having a biphenylene group represented by the following chemical formula 1. Is 1 to 50 nm, and is composed of titanium dioxide and ferric oxide, and its mixing ratio (TiO ₂ / F
10 to 200 parts by weight of metal oxide fine particles having an e ₂ O ₃ : weight ratio of 20 to 99 are contained, and a cured film is formed by irradiation of ultraviolet rays, and the cured film has a refractive index of 1.54 to 1 ．
70. The ultraviolet-curable composition, which is 70. Embedded image R ₁ —C ₆ H ₄ —C ₆ H ₄ —R _{2 In} Chemical Formula 1, R ₁ and R ₂ are —O— (CH ₂ CH ₂ O) _m —COCH═CH ₂ (provided that m is an integer of 0-3.) _{or, -O- (CH 2 C (OH} ) HCH 2 O) n -COCH = C
H ₂ (where, n is an integer of 1-3.) _{Or, -COO- (CH 2 CH 2 O} ) p -COCH = CH 2 ( Here, p is an integer of 1-3.) Shows the , And may be the same or different.