JP2016102188A - Photocurable resin composition and high refractivity resin hardened body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocurable resin composition that can produce a resin hardened body having a higher refractive index than the conventional photocurable resin composition, and to provide a high refractivity resin hardened body obtained by molding and hardening the same.SOLUTION: There is provided a photocurable resin composition containing a compound represented by the formula (1), and a mono-functional epoxy compound having a phenyl phenol skeleton. (R is each independently a C1 to 3 methylene group or an alkylene group; n is each independently an integer of 0 or more.)SELECTED DRAWING: None

Description

  The present invention relates to a photocurable resin composition and a highly refractive resin cured body.

High refractive index plastics are widely used for optical materials because of their ease of molding and light weight.
As a means for achieving a high refractive index, for example, a method of blending a bifunctional epoxy compound having a fluorene skeleton excellent in fast curing and high refractive properties into a photocurable resin composition can be mentioned (for example, Patent Document 1). .

Japanese Patent Laid-Open No. 2005-314692

  However, conventional photocurable resin compositions containing a bifunctional epoxy compound having a fluorene skeleton (hereinafter referred to as conventional photocurable resin compositions) are highly functional devices such as thin lenses and displays in recent years. In response to the demand for higher refractive index due to miniaturization, further improvement in refractive index is required.

  The present invention relates to a photocurable resin composition capable of producing a resin cured product having a higher refractive index than that of a conventional photocurable resin composition, and a highly refractive resin cured product obtained by molding and curing the composition. It is an issue to provide.

The present invention
[1] The following formula (1):

(Wherein, R is a methylene group or alkylene group having 1 to 3 carbon atoms, and may be the same or different, and n is a number of 0 or more, and may be the same or different). Bifunctional epoxy compound (component A) having a fluorene skeleton, and the following formula (2):

(Wherein m is a number from 1 to 3), a photocurable resin composition containing a monofunctional epoxy compound (component B) having a phenylphenol skeleton, and
[2] A highly refractive resin cured product obtained by molding and curing the photocurable resin composition according to item 1 above.

  According to the present invention, a photocurable resin composition capable of producing a cured resin having a higher refractive index than a conventional photocurable resin composition, and a highly refractive resin obtained by molding and curing the composition. A cured body can be provided.

(1) Component A
The photocurable resin composition of the present invention (hereinafter also referred to as a photocurable resin composition) has the following formula (1):

(Wherein, R is a methylene group or alkylene group having 1 to 3 carbon atoms, and may be the same or different, and n is a number of 0 or more, and may be the same or different). A bifunctional epoxy compound-curable compound (component A) having a fluorene skeleton is included.

R in Formula (1) is a methylene group or alkylene group having 1 to 3 carbon atoms.
Examples of the alkylene group include an ethylene group and a propylene group. From the viewpoint of imparting a high refractive index, a methylene group and / or an ethylene group is preferable, and a methylene group is more preferable.
R may be the same as or different from each other, but are preferably the same from the viewpoint of the productivity of Component A.

N in the formula (1) is a number of 0 or more from the viewpoint of imparting a high refractive index, but from the viewpoint of moldability, the component A is preferably 50 to 200 ° C, more preferably 50 to 150 ° C, and further Preferably, n is selected such that the component A has sufficient fluidity to be molded when heated at 50 to 100 ° C., more preferably 0 to 2.
n may be the same as or different from each other, but are preferably the same from the viewpoint of the productivity of Component A.

Specific examples of component A include 9,9-bis (glycidyloxy C _2-3 alkoxyphenyl) fluorene.

  Component A can be obtained by reacting the corresponding alkylene oxide adduct of 9,9-bis (hydroxyphenyl) fluorenes with epichlorohydrin.

In addition, the manufacturing method of the alkylene oxide adduct of 9,9-bis (monohydroxyphenyl) fluorene is, for example, 9,9-bis (hydroxyphenyl) fluorene and the corresponding alkylene oxide ( _C2-3 alkylene oxide). ) In the presence of a catalyst (such as a base catalyst) as necessary.

  As component A, commercially available product Ogsol EG-200 manufactured by Osaka Gas Chemical Co., Ltd. can be used.

(2) Component B
The photocurable resin composition has the following formula (2):
(Wherein m is a number from 1 to 3), and a monofunctional epoxy compound (component B) having a phenylphenol skeleton.

  M in Formula (2) is a number from 1 to 3 from the viewpoint of high refractive index after curing of the photocurable resin composition, and is 1, that is, Component B is 2-biphenylylglycidyl ether. Preferably there is.

  As Component B, commercially available OPP-G manufactured by Sanko Co., Ltd. can be used.

The resin cured body of the photocurable resin composition in which Component A and Component B are blended gives a higher refractive index than the conventional resin cured body of the photocurable resin composition (for example, Example 1 described later).
In addition, the refractive index of the resin cured body of the photocurable resin composition measured as follows is referred to as “refractive index of the photocurable resin composition”.
[Measurement method of refractive index of photocurable resin composition]
A silicone mold having an opening with a width of 1 cm, a length of 3 cm, and a depth of 0.5 cm is placed on a transparent PET film, and liquid photocuring is performed from the opening of the silicone mold (width 1 cm, length 3 cm). The resin composition is filled, and the opening is covered with another transparent PET film to produce a sample for light irradiation.
The sample for light irradiation was irradiated with 6000 mJ / cm ² of light having a wavelength of 365 nm with a metal halide lamp (for example, ECS-301 manufactured by Eye Graphics) to cure the filled photocurable resin composition, and then PET. The film and the silicone mold are removed, and the cured photocurable resin composition is further subjected to a heat treatment at 120 ° C. for 30 minutes in a hot air dryer to form a cured resin body.
The refractive index (25 ° C.) of the cured resin is measured with an Abbe refractometer (for example, 2T: manufactured by Atago Co., Ltd.).

Since the bifunctional epoxy compound having a fluorene skeleton as component A has a high viscosity, the conventional photocurable resin composition is blended with a low-viscosity photocurable compound in order to obtain a viscosity that does not hinder moldability. Was.
However, the conventional photocurable resin composition not containing component B was difficult to adjust to a lower viscosity even when a low viscosity photocurable compound was added (for example, Comparative Example 2 described later). And 3).

  In the photocurable resin composition in which the component A and the component B are blended, the viscosity can be reduced by adjusting the composition ratio of the component A and the component B. Furthermore, a low-viscosity photocurable compound (preferably The component C) described later can be blended to easily adjust to a lower viscosity (for example, Examples 2 to 6 described later).

  Moreover, in the photocurable resin composition with which component A and component B were mix | blended, compared with the radical photocurable resin composition by the conventional photocurable resin composition or acrylate, etc., the shrinkage | contraction rate of a resin cured body And curling can be reduced, so that the molding accuracy of the cured resin is improved.

(3) Component C
In addition to Component A and Component B, the photocurable resin composition further includes an oxetane compound having a phenyl group and / or an epoxy compound having a phenyl group as a component for adjusting the viscosity of the photocurable resin composition. It is preferable to include a compound (component C) having a viscosity of 2000 mPa · s or less, preferably 1000 mPa · s or less, more preferably 100 mPa · s or less.

  From the viewpoint of imparting a certain level of hardness to the highly refractive resin cured body, when the ratio of component A in the total amount of component A and component B is maintained at a certain level or more, the component C is blended to form a photocurable resin composition. It is preferable to adjust the viscosity of the product.

  Component C is an epoxy resin having a phenyl group (excluding Component A and Component B) from the viewpoint that the viscosity of the photocurable resin composition can be further reduced, and the viscosity is 2000 mPa · s or less, Preferably, the compound is 1000 mPa · s or less, more preferably 100 mPa · s or less.

As an oxetane resin having a phenyl group,
3-ethyl-3- (phenoxymethyl) oxetane (for example, OXT-211 (POX) manufactured by Toagosei Co., Ltd.) and / or 1,4-bis {[(3-ethyloxetane-3-ioxetanyl) methoxy] methyl} benzene (For example, Toagosei Co., Ltd. OXT-121 (XDO)) is preferable,
3-ethyl-3- (phenoxymethyl) oxetane is more preferred.

As an epoxy resin having a phenyl group,
Phenyl glycidyl ether (for example, EX-141 manufactured by Nagase ChemteX) and / or phenol (EO) 5 glycidyl ether is preferred,
More preferred is phenyl glycidyl ether.

(4) Component D

Since the photocurable resin composition containing Component A and Component B is cationically polymerizable, Component B preferably contains a photopolymerization initiator (Component D) that acts as a photoacid generator.
Component D is preferably a Lewis acid such as trialkylborane, trihalogenborane, trialkylaluminum, trialkylaluminum ion or hexafluorophosphoric acid from the viewpoint of curability in addition to normal strength and endurance strength. , A compound that generates Bronsted acid such as hexafluoroantimonic acid (preferably hexafluorophosphoric acid), preferably sulfonium salt and / or iodonium salt, hexafluorophosphoric acid, hexafluoroantimonic acid (preferably hexafluorophosphoric acid) More preferred are sulfonium salts of compounds that generate Bronsted acids such as (acid).

As a sulfonium salt, in addition to normal strength and durability strength, from the viewpoint of curability,
Triphenylsulfonium hexafluorophosphate,
Triphenylsulfonium hexafluoroantimonate,
Triphenylsulfonium tetrakis (pentafluorophenyl) borate,
4,4′-bis [diphenylsulfonio] diphenyl sulfide bishexafluorophosphate,
4,4′-bis [di (β-hydroxyethoxy) phenylsulfonio] diphenyl sulfide bishexafluoroantimonate,
4,4′-bis [di (β-hydroxyethoxy) phenylsulfonio] diphenyl sulfide bishexafluorophosphate,
7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone hexafluoroantimonate,
7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone tetrakis (pentafluorophenyl) borate,
4-phenylcarbonyl-4′-diphenylsulfonio-diphenyl sulfide hexafluorophosphate,
4- (p-tert-butylphenylcarbonyl) -4'-diphenylsulfonio-diphenyl sulfide hexafluoroantimonate,
4- (p-tert-butylphenylcarbonyl) -4′-di (p-toluyl) sulfonio-diphenyl sulfide tetrakis (pentafluorophenyl) borate and the like are preferable.

As the commercially available sulfonium salt cationic polymerization initiator, SP-170, SP-172, SP-150, SP-152 manufactured by Asahi Denka Co., Ltd., CPI-110P, CPI-210S manufactured by San Apro, and the like are preferable. CPI-110P manufactured by Asahi Denka Co., Ltd., SP-170 and SP-172 manufactured by Asahi Denka are more preferable, and CPI-110P manufactured by San Apro is more preferable.
These salts may be used alone or in combination of two or more.

As an iodonium salt, in addition to normal strength and durability strength, from the viewpoint of curability,
Diphenyliodonium tetrakis (pentafluorophenyl) borate,
Diphenyliodonium hexafluorophosphate,
Diphenyliodonium hexafluoroantimonate,
Di (4-nonylphenyl) iodonium hexafluorophosphate and the like are preferable.
As a commercially available iodonium salt-based cationic polymerization initiator, PI2074 manufactured by Rhodia is preferable.
These salts may be used alone or in combination of two or more.

(5) Other additives [plasticizer]
Following formula (3):

(Wherein R ^4a and R ^4b are a hydrogen atom or a (meth) acryloyl group,
R ^1a and R ^1b are non-radically polymerizable substituents,
R ^2a and R ^2b are alkylene groups,
R ^3a and R ^3b are non-radically polymerizable substituents,
k1 and k2 are each an integer of 0 to 4,
m1 and m2 are each an integer of 0 or more,
n1 and n2 are each an integer of 1 to 4,
p1 and p2 each represent an integer of 0 to 4,
By adjusting the amount of the compound represented by n1 + p1 ≦ 5 and n2 + p2 ≦ 5, the scratch resistance may be improved more advantageously or effectively in combination with the plastic effect.

In the formula (3), the number of (meth) acryloyl groups among n1 + n2 R ^4a and R ^4b may be 1 or more and smaller than n1 + n2. For example, when (i) n1 = n2 = 1, the number of (meth) acryloyl groups is 0-2, and (ii) when n1 = n2 = 2, the number of (meth) acryloyl groups is 0-4. Yes, (iii) When n1 = n2 = 3, the number of (meth) acryloyl groups is 0-6.
In the formula (3), when n1 + n2 is 3 or more, the number of (meth) acryloyl groups is the average value of the whole compound represented by the formula (2) as in the case of the polyfunctional (meth) acrylate. Represented as:

〔solvent〕
The photocurable resin composition can be a liquid, such as a solution containing a solvent, a slurry, or a paste, from the viewpoint of being applied to the surface of a substrate to be bonded such as a liquid crystal display element.

  Examples of the organic solvent include alcohols, glycol ethers, esters, and ketones.

Examples of alcohols include pentanol, hexanol, cyclohexanol, ethylene glycol, and propylene glycol.
Examples of glycol ethers include ethyl ethoxy acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 2-methoxypropionate, 2-methoxypropionic acid. Ethyl, propyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, methyl 2-methoxy-2-methylpropionate, ethyl 2-ethoxy-2-methylpropionate, 3-methoxybutyl acetate , 3-methyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, ethylene glycol Monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and the like diethylene glycol monoethyl ether acetate.
Esters include methyl lactate, ethyl lactate, butyl lactate, methyl 2-hydroxyisobutanoate, isopentyl acetate, butyl propionate, isopropyl butyrate, ethyl butyrate, butyl butyrate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, aceto Examples include methyl acetate, ethyl acetoacetate, cyclohexanol acetate, and γ-butyrolactone.
Examples of ketones include 4-hydroxy-4-methyl-2-pentanone, 2-heptanone, 3-heptanone, 4-heptanone, cyclopentanone, cyclohexanone, and isophorone.

  Depending on the purpose, the photocurable resin composition may be, for example, an antioxidant, an ultraviolet absorber, a light stabilizer, a silane coupling agent, a polymerization inhibitor, a leveling agent, a surfactant, a colorant, a storage stabilizer, Plasticizers, lubricants, fillers, anti-aging agents, wettability improvers, mold release agents, and the like can be added.

(6) Photocurable resin composition Although each component of component A and component B or component A, component B and component C is liquid or solid, these are preferably 50-200 degreeC, More preferably, it is 50. The photo-curable resin composition obtained by heating and mixing at ˜150 ° C., more preferably at 50˜100 ° C. can be used as a liquid such as a solution, slurry or paste, and other additives as necessary Can be used as a liquid such as a solution, slurry, or paste.

  The suitable composition of a photocurable resin composition is demonstrated.

  From the viewpoint of high refraction and viscosity reduction, the mass ratio of component A and component B (component A / component B) is preferably 1/99 to 99/1, and preferably 10/90 to 90/10. Is more preferable, 20/80 to 80/20 is still more preferable, and 30/70 to 70/30 is still more preferable.

From the viewpoint of high refraction and viscosity reduction, Component C is a total of 100 parts by mass of Component A and Component B.
It is preferably 1 to 200 parts by mass,
More preferably 5 to 100 parts by weight,
Component C is an epoxy resin having a phenyl group (excluding component A and component B), and the viscosity is preferably 2000 mPa · s or less, more preferably 1000 mPa · s or less, and still more preferably 100 mPa · s or less. When it is a certain compound, it is preferable that it is 1-100 mass parts with respect to a total of 100 mass parts of component A and component B, It is more preferable that it is 1-50 mass parts, 5-30 mass parts More preferably, it is 5 to 15 parts by mass.

  From the viewpoint of ensuring the room for blending other components for adjusting the practical performance of the photocurable resin composition and the viewpoint of high refraction and viscosity reduction, the component A in the solid content of the photocurable resin composition and The ratio of the total amount of component B is preferably 10 to 100% by mass, more preferably 20 to 90% by mass, and still more preferably 40 to 80% by mass.

  From the viewpoint of normal strength, durability strength and curability, component D is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 7 parts by mass, relative to 100 parts by mass of component A, More preferably, it is 1-5 mass parts.

The viscosity of the photocurable resin composition is adjusted by adjusting the mass ratio of component A and component B, or by adding a photocurable compound capable of adjusting the viscosity such as component C to component A and component B,
It is preferably adjusted to 100 to 20000 mPa · s,
More preferably, it is adjusted to 200 to 10,000 mPa · s,
More preferably, it is adjusted to 500 to 7000 mPa · s,
More preferably, it is adjusted to 500 to 5000 mPa · s,
More preferably, it is adjusted to 500 to 3000 mPa · s.

  Since the photocurable resin composition having the above-mentioned preferred composition can be adjusted to a high refractive index of 1.6 or higher, when it is molded and cured, it has a high refractive index of 1.6 or higher. A highly refractive resin cured body can be produced.

(6) High refractive resin cured body

  The highly refractive resin cured body can be produced by forming a photocurable resin composition into a shape suitable for the purpose, irradiating the molded body with light, and curing it by a curing reaction.

  The highly refractive resin cured body may be, for example, a one-dimensional or two-dimensional cured body such as a three-dimensional cured body, a cured film, or a cured pattern, or a dot or dot-shaped cured body.

  The photocurable resin composition may be molded, for example, by forming a film-like body of the photocurable resin composition on a base material, or filling it into a mold according to the application and three-dimensionally molding it.

  As a method of forming a film-like body of a photocurable resin composition on a substrate, for example, a flow coating method, a spin coating method, a spray coating method, a screen printing method, a casting method, a bar coating method, a curtain coating method, Examples thereof include a roll coating method, a gravure coating method, a dipping method, and a slit method.

When the highly refractive resin cured body is in the form of a film or a sheet, the thickness of the highly refractive resin cured body is preferably about 0.01 μm to 10 mm, depending on the use of the cured product.
In the case of a photoresist, it is preferably 0.05 to 10 μm, more preferably 0.1 to 5 μm,
In the case of a printed wiring board, it is preferably 10 μm to 5 mm, more preferably 100 μm to 1 mm,
In the case of an optical thin film, it is preferably 0.1 to 100 μm, and more preferably 0.3 to 50 μm.

  In the case of a high-refractive resin cured body for lens use, the high-refractive resin cured body has a convex slope on both sides or a convex slope on one side and the other side is in close contact with a substrate such as glass. The form is preferred.

  The light to be irradiated or exposed may be, for example, ultraviolet light or visible light, depending on the photopolymerization initiator, but suppresses the color of the highly refractive resin cured body and improves transparency, preferably colorless transparency. From the viewpoint of improvement, ultraviolet rays are more preferable.

  The wavelength of light is preferably 150 to 450 nm, preferably 200 to 400 nm from the viewpoint of improving transparency by suppressing the color of the fast-curing and highly refractive resin cured body, and preferably improving colorless transparency. More preferably, it is more preferably 300 to 400 nm.

From the viewpoint of sufficiently proceed the curing reaction, irradiation light amount varies depending on the thickness of the coating film is preferably 1500~10000mJ / cm ^2, more preferably 2000~9000mJ / cm ^2, 3000~9000mJ / Cm ² is more preferable, and 4000 to 7000 mJ / cm ² is more preferable.

  The light source can be selected according to the type of light to be exposed. For example, in the case of ultraviolet rays, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a deuterium lamp, a halogen lamp, a laser beam (helium-cadmium laser, Excimer laser etc.) can be used.

The molded photocurable resin composition is heated after light irradiation or with light irradiation as necessary, but is often performed after light irradiation.
The heating temperature is preferably 60 to 250 ° C, more preferably 100 to 200 ° C,
The heating time is preferably 1 minute to 2 hours, more preferably 10 minutes to 1 hour, further preferably 20 minutes to 1 hour, and further preferably 30 minutes to 1 hour. .

  When a pattern or an image is formed (for example, when a printed wiring board is manufactured), the coating film formed on the substrate may be subjected to pattern exposure, and this pattern exposure may be performed by scanning with a laser beam. Alternatively, light irradiation may be performed through a photomask.

A pattern or an image can be formed by developing (or dissolving) a non-irradiated region (unexposed portion) generated by pattern exposure with a developer.
When the coating is heated after the exposure, the development step may be performed before the heating step or after the heating step.

  Since these methods can form a fine and high-precision pattern on a base material even with a small exposure amount, they are suitable for applications that require a precise pattern, for example, printed wiring boards for electronic devices. .

When forming an optical thin film, you may form multiple layers of photocurable resin compositions on a base material.
Moreover, after forming another functional layer etc. on a base material, you may form the layer formed with the photocurable resin composition on the functional layer.

  The material of the base material is selected according to the application. For example, in the case of a printed wiring board or an optical thin film, a semiconductor such as silicon, gallium arsenide, gallium nitride, or silicon carbide, a metal such as aluminum or copper, zirconium oxide, Ceramics such as titanium oxide and PZT, transparent inorganic materials (glass, quartz, magnesium fluoride, calcium fluoride, etc.), transparent resins (polymethyl methacrylate, polymethyl acrylate, polystyrene, etc.), etc. are used.

  Since the high refractive resin cured body can have a high refractive index of 1.6 or higher, various lenses such as Fresnel lenses, lenticular lenses, prism lenses, and micro lenses, and high refractive index of antireflection films such as liquid crystal displays. It is preferably used for optical applications such as optical layers such as index layers, reflectors, optical fiber core materials, clad materials, optical waveguides, holograms, Fresnel lenses, lenticular lenses, prism lenses, micro lenses, etc. It is more preferable to use it for various lenses.

〔Compound〕
(1) Component A
(Compound a) Bifunctional epoxy compound having a fluorene skeleton (Ogsol EG-200, manufactured by Osaka Gas Chemical Co., Ltd., highly viscous liquid at normal temperature)

(2) Component B
(Compound b) Monofunctional epoxy compound having a phenylphenol skeleton (manufactured by Sanko Co., Ltd., OPP-G, solid at room temperature)

(3) Component C
(Compound c1) Phenyl oxetane monomer (OXT-211 (POX) manufactured by Toagosei Co., Ltd., viscosity 14 mPa · s)
(Compound c2) Xylene bisoxetane monomer (OXT-121 (XDO) manufactured by Toagosei Co., Ltd., viscosity 160 mPa · s)
(Compound c3) Phenyl epoxy monomer (EX-141 manufactured by Nagase ChemteX, viscosity: 8 mPa · s)

(4) Component D
(Compound d) Hexafluorophosphonic photoacid generator (CPI-110P manufactured by Sun Apro)

(5) Other compounds (Compound e1) Bisphenol type bifunctional epoxy monomer (830S manufactured by DIC, viscosity 3000 to 4500 mPa · s)
(Compound e2) 1,2-epoxy-4-vinylcyclohexane monomer (Delcel Celoxide 2000, viscosity 1.7 mPa · s)
(Compound e3) Bisphenol type bifunctional epoxy monomer (830 LVP manufactured by DIC, viscosity 1200 to 1800 mPa · s)
(Compound e4) 3-ethyl-3 {[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane monomer (OXT-221 (DOX) manufactured by Toagosei Co., Ltd., viscosity 13 mPa · s)

[Photocurable resin composition]
According to the blending ratio shown in Table 1, components A to D and other components were stirred and mixed at 80 ° C. for 30 minutes to 1 hour until uniform in a flask equipped with a stirrer. -6 liquid photocurable resin compositions were obtained.

〔Test method〕
(1) Refractive index The sample for light irradiation was irradiated with 6000 mJ / cm ² of light having a wavelength of 365 nm with a metal halide lamp (ECS-301 manufactured by Eye Graphics Co., Ltd.) to cure the filled photocurable resin composition. Thereafter, the PET film and the silicone mold were removed, and the cured photocurable resin composition was further subjected to a heat treatment at 120 ° C. for 30 minutes in a hot air dryer to form a cured resin.
The refractive index (25 ° C.) of this cured resin was measured with an Abbe refractometer (2T: manufactured by Atago Co., Ltd.).

(2) Viscosity About the photocurable resin composition of Comparative Examples 1-3 and Examples 1-6, it measured at 25 degreeC using the E-type viscosity meter (Toki Sangyo Co., Ltd. RE-105U).

〔result〕

  The conventional photocurable resin composition containing Component A (Comparative Example 2) has a higher refractive index than the photocurable resin composition containing no Component A (Comparative Example 1), but has a viscosity. Will also increase. Even if the blending ratio of component A is increased, if the blending adjustment is performed to maintain the viscosity, the refractive index of the cured resin body is lowered, so it is difficult to increase the refractive index of the cured resin body.

  When component B is combined with component A, the refractive index of the cured resin increases even if the blending ratio of component A is small, and a highly refractive cured resin having a refractive index of 1.6 or more can be produced (implementation). Example 1).

  Increasing the proportion of component B in the total amount of component A and component B can greatly reduce the viscosity while maintaining a refractive index of 1.6 or higher.

  The photocurable resin composition can be obtained while maintaining the refractive index of the highly refractive resin cured product at 1.6 or more by adding the component C to the photocurable resin composition containing the component A and the component B (Example 1). It can be seen that the viscosity-reducing effect can be easily reduced (Examples 4 and 5), and the viscosity-reducing effect is particularly great when an epoxy resin having a phenyl group is included (Example 6).

Moreover, when the ratio of the component A in the total amount of the component A and the component B is made constant and the component C is added, the viscosity of the photocurable resin composition is reduced while maintaining the hardness of the highly refractive resin cured body. (Examples 1, 4 and 6).

Claims (5)

Following formula (1):
(Wherein, R is a methylene group or alkylene group having 1 to 3 carbon atoms, and may be the same or different, and n is a number of 0 or more, and may be the same or different). Bifunctional epoxy compound (component A) having a fluorene skeleton, and the following formula (2):
A photocurable resin composition comprising a monofunctional epoxy compound (component B) having a phenylphenol skeleton represented by (wherein m is a number of 1 to 3).   Furthermore, it is an oxetane compound having a phenyl group and / or an epoxy compound having a phenyl group (excluding the component A and the component B), and a compound having a viscosity of 2000 mPa · s or less (component C). Item 2. The photocurable resin composition according to Item 1.   The photocurable resin composition according to claim 1 or 2, wherein the refractive index is 1.6 or more.   A highly refractive resin cured body obtained by molding and curing the photocurable resin composition according to claim 1. The high refractive resin cured body according to claim 4, wherein the high refractive resin cured body is a lens.