JP2002356524A - Active energy ray-hardenable resin composition for cast polymerization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active energy ray-hardenable resin composition which is excellent in adhesion to a transparent plastic base material, mold release characteristics from a mold matrix and transparency, has excellent shape- retaining property of a molded resin layer formed on a transparent base material over a broad temperature range and further hardly causing cleaving and cracking. SOLUTION: A hardened product is obtained by active energy ray-hardening of from resin composition containing an essential components an glycidyl(meth) acrylate, (meth)acrylate compound of an aliphatic polyvalent alcohol and monofunctional (meth)acrylate, and has a specified value with the measurement of dynamic viscoelasticity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active energy ray-curable resin composition used for casting polymerization utilizing a curing reaction by irradiation with active energy rays. More specifically, after the active energy ray-curable resin composition is placed between a matrix having a required shape and a plate-shaped or sheet-shaped transparent plastic substrate serving as a support, the active energy ray is irradiated. Used to manufacture articles with a structure in which a molded resin layer made of a resin cured product is provided on a substrate, for example, to manufacture plastic articles such as shaped sheets, lenses, optical components, optical disks, prisms, etc. The present invention relates to an active energy ray-curable resin composition for cast polymerization.

[0002]

2. Description of the Related Art In recent years, with the miniaturization and weight reduction of equipment, in particular, parts having a fine and complicated uneven surface shape composed of a resin-cured material on a plate-shaped or sheet-shaped transparent plastic substrate, A lens with a flat or aspheric surface shape,
The need for plastic articles such as prisms or mirrors is increasing.

[0003] Such plastic articles usually include
High mechanical strength and toughness of the molding resin layer, excellent adhesion to the transparent plastic base material used and excellent mold release from the matrix, and excellent durability because it needs to withstand long-term use Is required. Also,
These plastic articles are required to have durability at high temperatures due to their various use environments, and are also required to have good shape retention at high temperatures and mechanical properties.

Accordingly, various methods have been proposed for producing a replica of a matrix by interposing a reactive resin between the matrix and the transparent plastic substrate and curing the reactive resin by heat or ultraviolet rays. .

Japanese Patent Publication No. 4-5681 discloses a method of improving the thermal dimensional stability and improving the mechanical properties by cross-linking and curing a mixture of compounds called soft segments and hard segments by irradiating ultraviolet rays. It has been disclosed.

In Japanese Patent Application Laid-Open No. 4-329501 or Japanese Patent Application Laid-Open No. 6-67004, the elastic modulus of a microlens array cured product produced by casting polymerization of an active energy ray-curable resin composition is specified. By selecting within the range,
It is disclosed that the distortion of the tip of the formed optical article shape and warpage due to polymerization shrinkage can be improved.

[0007] Japanese Patent Application Laid-Open No. 64-65111 discloses that an epoxy (meth) acrylate-based resin composition exhibiting a high elastic modulus of a cured product is combined with a specific photopolymerization initiator to reduce the depth curability and curing distortion. It is disclosed that it can be improved.

Further, Japanese Patent Application Laid-Open Nos. Hei 5-287040 and Hei 11-60656 disclose a cast polymerization method using an epoxy (meth) acrylate resin composition exhibiting a cured product having a high modulus of elasticity. It is disclosed that the hardness, heat resistance, durability and the like of the manufactured optical article can be improved.

However, when a plastic article is actually manufactured, it has been found that it is difficult to completely solve the following disadvantages even with these conventional manufacturing methods. That is, when a plastic article is made using a hard resin (a resin having a high elastic modulus), although the shape reproducibility of the molded product and the surface hardness are good, especially when the molded product is a sheet, When an external force is applied in a manufacturing process or the like, the molded shape tends to be chipped or cracked. On the other hand, when a plastic article is made using a flexible resin (a resin having a low elastic modulus), the above-mentioned disadvantages are improved, but the article is easily deformed, and particularly when the molded article is in a sheet shape, these are removed. Deformation is likely to occur when laminating, and the shape of the formed replica, particularly the shape of the pressed tip, is distorted, and the reproducibility of the shape of the molded product is insufficient.

Accordingly, there has been a demand for an active energy ray-curable resin composition for cast polymerization which satisfies each required property.

[0011]

The problem to be solved by the present invention is that the molding resin layer formed on the transparent substrate as described above has excellent adhesion and transparency to a transparent plastic substrate, and can be used in a wide temperature range. An object of the present invention is to provide an active energy ray-curable resin composition for casting polymerization, which exhibits excellent shape retention power and is less likely to be chipped or cracked by external force.

[0012]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that an epoxy (meth) acrylate, a (meth) acrylate compound of an aliphatic polyhydric alcohol, The active energy ray-curable resin composition for cast polymerization containing a monofunctional (meth) acrylate as an essential component is cured with an active energy ray. The crosslinked structure observed from the elastic behavior was found to be important.

In particular, the dynamic loss tangent, which is obtained by measuring the dynamic viscoelasticity of the resin composition and shows a correlation with the crosslinked structure and the crosslinked density of the cured product of the composition, and the storage elastic modulus in the rubber elastic region, [T (max)] indicating the maximum value of the mechanical loss tangent, the maximum value [Tan δ (max)] of the mechanical loss tangent, and the temperature difference [ΔT (0 .1)] for casting polymerization in which the storage elastic modulus [E '(Tmax + 40 ° C)] at a temperature 40 ° C higher than the temperature [T (max)] at which the maximum value of the mechanical loss tangent is obtained is in a specific range. By using the active energy ray-curable resin composition, the obtained cured product retains high hardness and a high refractive index, and is not easily chipped or cracked by an external force. It has been found that the present invention has excellent properties and exhibits excellent shape retention in a wide temperature range, and has completed the present invention.

That is, the present invention provides an epoxy (meth) acrylate (a) having two or more (meth) acryloyl groups, a (meth) acrylate compound (b) of an aliphatic polyhydric alcohol, and a monofunctional compound. An active energy ray-curable resin composition containing (meth) acrylate (c) as an essential component, and a cured product cured by irradiation with active energy rays obtained by dynamic viscoelasticity measurement at a frequency of 1 Hz. Temperature [T (ma) showing the maximum value of the loss tangent
x)] is 50 ° C. or more and the maximum value of the mechanical loss tangent [Tan
δ (max)] is 0.7 to 2.0, and the temperature difference [ΔT (0.1)] at two points where the mechanical loss tangent value is 0.1 is 60 ° C. or less, and the mechanical loss tangent is temperature indicating the maximum value of [T (max)] storage modulus at from 40 ° C. higher temperatures [E '(Tmax + 40 ℃)] is, 5.0 × ¹⁰ 6 ~
The present invention provides an active energy ray-curable resin composition for casting polymerization, which is 2.0 × 10 ⁷ Pa.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
An epoxy (meth) acrylate (a) having two or more (meth) acryloyl groups and a (meth) acrylate compound (b) of an aliphatic polyhydric alcohol according to the present invention
And an active energy ray-curable resin composition for cast polymerization containing a monofunctional (meth) acrylate (c) as an essential component (hereinafter abbreviated as an article), for example, a plate-like or Articles provided with a molded resin layer obtained by curing the resin composition of the present invention on a sheet-shaped transparent plastic substrate include, during an article manufacturing process, or when incorporating an article into an apparatus, an external force is applied. May be locally deformed. For example, when a sheet-like article is wound up with foreign matter or bubbles interposed, a large stress is locally applied to the location of the foreign matter, and a sheet take-up roll or a large number of plate-like or sheet-like articles are laminated. When stored as it is, the stress is locally concentrated by its own weight, and such local deformation may be distorted and remain.

This problem can be solved by increasing the elastic modulus of the molding resin layer. However, simply adjusting the elastic modulus does not sufficiently improve the hardness and brittleness of the molding resin layer. When an impact is applied to the formed fine shape or when the formed fine shape is cut into a desired size, cracks, chips, cracks, and the like occur.

Generally, the hardness and mechanical properties of an active energy ray-curable resin composition are affected by the rigidity of the resin skeleton, the crosslink density, and the like. In particular, in the case of a resin composition exhibiting a cured product having a high elastic modulus, the glass transition temperature of the cured resin often becomes higher than the ambient temperature during curing. Therefore, in this case, the crosslink density of the cured resin material varies depending on the reaction rate of the crosslinkable functional group, and it is not sufficient to specify only the concentration of the crosslinkable functional group in the resin composition.

The active energy ray-curable resin composition for cast polymerization of the present invention comprises an epoxy (meth) acrylate (a) having two or more (meth) acryloyl groups and a (meth) acrylate of an aliphatic polyhydric alcohol. An epoxy (meth) acrylate-based resin composition containing an acrylic ester compound (b) and a monofunctional (meth) acrylate (c) as essential components and having high elasticity and cured properties, and has a wide temperature range Thus, both excellent shape retention and toughness can be achieved. Further, the cured product of the composition has a temperature [T (max)] at which the mechanical loss tangent, which shows a correlation with the crosslinked structure and the crosslink density, and the storage elastic modulus in the rubber elastic region show the maximum value of the mechanical loss tangent. , The maximum value of the mechanical loss tangent [T
anδ (max)], a temperature difference [ΔT (0.1)] between two points at which the mechanical loss tangent value is 0.1, and 40 ° C. from a temperature [T (max)] at which the maximum mechanical loss tangent value is obtained. When the storage elastic modulus [E ′ (Tmax + 40 ° C.)] at a high temperature has a value within the above range, the hardness and brittleness of a molded resin layer using the composition can be improved.

In general, the dynamic viscoelasticity measurement is easily affected by the thickness of the sample film. Therefore, the value of the dynamic viscoelasticity measurement described in the present invention is measured by a solid viscoelasticity measuring apparatus using a strain control method. (For example, RSA manufactured by Rheometrics Inc.
-2), film thickness 200 ± 25 μm, size 6 × 35
mm film, frequency 1 Hz, load strain 0.05%, heating rate 3 ° C./min, measurement temperature -50 to 15
Of the data measured under the condition at 0 ° C, -30 to 120 ° C
Was defined as a value determined from data obtained in the temperature range of

An epoxy (meth) acrylate (a) having two or more (meth) acryloyl groups, and a (meth) acrylate compound (b) of an aliphatic polyhydric alcohol
An active energy ray-curable resin composition for casting polymerization of the present invention, which contains a monofunctional (meth) acrylate (c) as an essential component, and a cured product obtained by curing with an active energy ray at a frequency of 1 Hz. Temperature [T (max)] at which the maximum value of the mechanical loss tangent by the measured dynamic viscoelasticity is measured
Is 50 ° C. or higher and the maximum value of the mechanical loss tangent [T
anδ (max)] is 0.7 to 2.0 and the mechanical loss tangent value is 0.1.
(0.1)] is 60 ° C. or less. That is, since the distribution of the mechanical loss tangent is sharp, a decrease in the elastic modulus of the cured product that undergoes thermal deformation is prevented up to the vicinity of the high-temperature region represented by [Tan δ (max)] while maintaining the toughness, Shape retention in a high temperature range can be improved.

When [T (max)] is less than 50 ° C.,
When an external force is applied to the formed fine shape, deformation tends to occur, which is not preferable. Also, [Tan δ (max)]
Is less than 0.7, the distribution of the mechanical loss tangent becomes broad, and the elastic modulus decrease near [Tan δ (max)] starts to occur at a low temperature, so that deformation tends to occur.
When [anδ (max)] exceeds 2.0, the distribution of mechanical loss tangent becomes sharp. However, it is necessary to reduce the rubber elastic modulus of the cured product, which is not preferable because the shape retention force is inferior. Further, when [ΔT (0.1)] exceeds 60 ° C., as described above, the distribution of the mechanical loss tangent becomes broad and the elastic modulus decrease near [Tan δ (max)] begins to occur at a low temperature. This is not preferred because it is likely to cause the following.

Above all, [T (m
ax)] is 50 to 70 ° C., and [Tan δ (ma
x)] is 0.8 to 1.5, and [ΔT (0.
1)] is preferably 35 to 45 ° C.

Further, the active energy ray-curable resin composition for cast polymerization of the present invention is used under the same conditions as the above-mentioned dynamic viscoelasticity measurement in order to further improve the shape retention of the molded resin layer in a high temperature range. It is essential to limit the value of the measured storage modulus in the rubber elasticity region of the cured product.

It is known that the value of the storage modulus in the rubber elasticity region of a cured product is correlated with the crosslink density of the cured product. The storage elastic modulus in this rubber elastic region is [T
(Max) at a temperature 40 ° C. higher than the storage modulus [E ′ (Tmax + 40 ° C.)], the value of [E ′ (Tmax + 40 ° C.)] is determined by setting the crosslink density of the cured product to an appropriate value. In order to prevent deformation, cracks and breakage due to external force from being applied to the formed fine shape, it is essential that the pressure be 5.0 × 10 ^{6 to} 2.0 × 10 ⁷ Pa. If it is less than 5.0 × 10 ⁶ Pa, the crosslink density is low, so that it is easy to deform. If it is more than 2.0 × 10 ⁷ Pa, the crosslink density becomes too high, and the shape is easily cracked or chipped by external force. Not preferred. Among them, it is particularly preferable that the pressure be 1.0 × 10 ^{7 to} 2.0 × 10 ⁷ Pa.

The epoxy (meth) acrylate (a) having two or more (meth) acryloyl groups used in the present invention includes, for example, aliphatic epoxy resin, bisphenol type epoxy resin, hydrogenated bisphenol type epoxy resin, novolak One or more epoxy (meth) acrylates obtained by the reaction of an epoxy resin having two or more epoxy groups such as a type epoxy resin and a naphthalene skeleton epoxy resin with (meth) acrylic acid, and mixtures thereof. Can be

Among them, epoxy (meth) acrylates having a cyclic structure and having two or more (meth) acryloyl groups, because they exhibit a high modulus of elasticity and can increase the refractive index if necessary. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, partially halogen substituted bisphenol A type epoxy resin, partially halogen substituted bisphenol F
Epoxy resins, hydrogenated bisphenol A type epoxy resins, and bisphenol type epoxy (meth) acrylates obtained by reacting one or more epoxy resins selected from the group consisting of a mixture thereof with (meth) acrylic acid. Can be

Of these, epoxy (meth) acrylate (a) is obtained by reacting (meth) acrylic acid with a cyclic structure epoxy resin having an average epoxy equivalent of 450 g / eq or more. 1) Epoxy acrylate (a ') having an acryloyl group is preferable because various values obtained by kinematic viscoelasticity measurement as shown in FIG. 1 become appropriate and the brittleness of the molded resin layer is improved. .

The average epoxy equivalent of the epoxy resin is 450
g / eq or more, for example, 450 g alone
Epoxy resins having an epoxy equivalent of / eq or more may be used, or epoxy resins having different epoxy equivalents may be mixed so that the average epoxy equivalent becomes 450 g / eq or more.

The epoxy acrylate (a ') used in the present invention is a mixture of epoxy acrylates obtained by using epoxy resins having different epoxy equivalents. The epoxy acrylate (a') has an average epoxy equivalent of 450 g / epoxy resin.
eq or more.

The aliphatic polyhydric alcohol (meth) acrylate compound (b) used in the present invention includes, for example, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate; diethylene glycol di (meth) acrylate. Polyethylene glycol di (meth) acrylates such as acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and heptaethylene glycol di (meth) acrylate; dipropylene glycol di (meth) acrylate, tripropylene glycol Di (meth) acrylate of polypropylene glycol such as di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, heptapropylene glycol di (meth) acrylate Rate; 1,3-butylene glycol di (meth) acrylate, 1,4-butylene glycol di (meth) acrylate, 1,6-hexamethylene glycol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate , Neopentyl glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate hydroxypivalate, di (meth) acrylate of a compound obtained by adding caprolactone to neopentyl glycol hydroxypivalate, neopentyl glycol adipate di (meth) acrylate, etc. A compound in which (meth) acrylic acid has two molecular ester bonds;

Trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, tetramethylol methane, and
Compounds in which three or more (meth) acrylic acids are ester-bonded to a compound having three or more hydroxyl groups, such as a hydroxyl group-containing compound to which 20 mol of alkylene oxide has been added, and the like.

Among them, the (meth) acrylate compound (b) of the aliphatic polyhydric alcohol of the present invention includes:
In order to improve the brittleness of the molded layer, a (meth) acrylate compound of an aliphatic polyhydric alcohol having an alkylene oxide structure and having two or more hydroxyl groups is preferable, for example, diethylene glycol di (meth) acrylate,
Polyethylene glycol di (meth) acrylates such as triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and heptaethylene glycol di (meth) acrylate; dipropylene glycol di (meth) acrylate, tripropylene glycol di ( Di (meth) acrylates of polypropylene glycol such as (meth) acrylate, tetrapropylene glycol di (meth) acrylate, heptapropylene glycol di (meth) acrylate;

Compounds having three or more hydroxyl groups such as trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, and hydroxyl-containing compounds obtained by adding 1 to 20 moles of alkylene oxide to tetramethylolmethane are (meth) acrylic. Examples include compounds in which three or more molecules of the acid are ester-bonded.

Among them, various values obtained by kinematic viscoelasticity measurement are within an appropriate range, and the alkylene oxide structure is propylene oxide in order to improve the adhesion to a plastic substrate without impairing a high elastic modulus. The (meth) acrylate compound (b ') of an aliphatic polyhydric alcohol having a propylene oxide structure and having two or more hydroxyl groups is preferable.

Examples of the compound (b ') include propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, and heptapropylene. Mono or polypropylene glycol di (meth) acrylates such as glycol di (meth) acrylate;

Trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, tetramethylolmethane, and 1 to 3
Compounds in which three or more (meth) acrylic acids are ester-bonded to a compound having three or more hydroxyl groups, such as a hydroxyl group-containing compound to which 20 mol of propylene oxide has been added, and the like.

The monofunctional (meth) acrylate (c) used in the present invention is not particularly limited. However, since it is possible to develop a high refractive index without deteriorating a high elastic modulus and, if necessary, Monofunctional (meta) having cyclic structure
Acrylate (c ') is preferred.

Examples of the monofunctional (meth) acrylate (c ′) having a cyclic structure include benzoyloxyethyl (meth) acrylate, benzyl (meth) acrylate, phenylethyl (meth) acrylate, phenoxyethyl (meth) acrylate, Phenoxydiethylene glycol (meth) acrylate, 2-hydroxy-3-
Phenoxypropyl (meth) acrylate; 2-phenyl-2- (4- (meth) acryloyloxyphenyl) propane represented by the following general formula (1), 2-phenyl-2- (4- (meth) acryloyl Oxyethoxyphenyl) propane, 2-phenyl-2- (4- (meth) acryloyloxypropoxyphenyl) propane and the like;

Embedded image (In the formula (1), R1 is a hydrocarbon group having 1 to 5 carbon atoms, R2
Represents hydrogen or a methyl group, and n represents an integer of 0 to 3. )

Chlorophenyl (meth) acrylate, bromophenyl (meth) acrylate, chlorobenzyl (meth) acrylate, bromobenzyl (meth) acrylate, chlorophenylethyl (meth) acrylate,
Bromophenylethyl (meth) acrylate, chlorophenoxyethyl (meth) acrylate, bromophenoxyethyl (meth) acrylate, 2,4,6-trichlorophenyl (meth) acrylate, 2,4,6-tribromophenyl (meth) acrylate 2,4,6-trichlorobenzyl (meth) acrylate, 2,4,6-tribromobenzyl (meth) acrylate, 2,4,6-trichlorophenoxyethyl (meth) acrylate, 2,4,6-tribromo Phenoxyethyl (meth) acrylate o-phenylphenol (poly) ethoxy (meth) acrylate, p-phenylphenol (poly) ethoxy (meth)
Monofunctional (meth) acrylates having an aromatic ring such as acrylate;

Cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl cyclocarbonate (meth) acrylate, (Meth) acrylic esters having an alicyclic and heterocyclic structure, such as N-vinylpyrrolidone, N-vinylcaprolactone, and acryloylformoline.

Among these, monofunctional (meth) acrylates having an aromatic ring can be suitably used because they do not impair the rigidity and high refractive index.

Each of the total of 100 parts by weight of the epoxy (meth) acrylate (a '), the (meth) acrylate compound (b') of the aliphatic polyhydric alcohol and the monofunctional (meth) acrylate (c ') was used. The content of the component is set so that various values obtained by kinematic viscoelasticity measurement as shown in FIG. 1 are in an appropriate range so that the properties of the cured product having a high elastic modulus, which is a characteristic of the epoxy acrylate resin composition, are appropriately exhibited. In order to improve the brittleness of the cured molding layer, 30 to 70 parts by weight of the epoxy (meth) acrylate (a ') and 5 to 5 parts of the (meth) acrylate compound (b') of the aliphatic polyhydric alcohol are used.
40 parts by weight, 5 monofunctional (meth) acrylates (c ')
It is preferably from 35 to 35 parts by weight.

In the active energy ray-curable resin composition for cast polymerization of the present invention, in addition to the above-mentioned components (a) to (c), for example, for the purpose of fine adjustment of viscosity and refractive index, etc.
Other unsaturated double bond-containing compound (d) can be contained.

Other unsaturated double bond-containing compounds (d)
For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate,
(Meth) acrylic acid esters having an alkyl group having 1 to 22 carbon atoms, such as octyl (meth) acrylate, dodecyl (meth) acrylate, and stearyl (meth) acrylate; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, (Meth) acrylates having a hydroxyalkyl group such as glycerol (meth) acrylate, lactone-modified hydroxyethyl (meth) acrylate, and (meth) acrylates having a polyalkylene glycol group such as polyethylene glycol and polypropylene glycol; (meth) Phosphoethyl acrylate; styrene compounds such as styrene, α-methylstyrene, chlorostyrene;

N, N-dialkylaminoalkyl (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate or N, N-diethylaminopropyl (meth) acrylate;

Bisphenol A ethylene oxide adducts and their halides, bisphenol A propylene oxide adducts and their halides, bisphenol F ethylene oxide adducts and their halides, bisphenol F propylene oxide adducts and their Halides, ethylene oxide adducts of bisphenol S and their halides, propylene oxide adducts of bisphenol S and their halides, 2,2'-di (hydroxypropoxyphenyl) propane and their halides 2,2 '
A compound in which two molecules of (meth) acrylic acid are ester-bonded to an alicyclic compound having two hydroxyl groups such as di (hydroxyethoxyphenyl) propane, a halide thereof, and tricyclodecanedimethylol;

Bis [4- (meth) acryloyloxyphenyl] -sulfide, bis [4- (meth) acryloyloxyethoxyphenyl] -sulfide, bis [4-
(Meth) acryloyloxypentaethoxyphenyl]
-Sulfide, bis [4- (meth) acryloyloxyethoxy-3-phenylphenyl] -sulfide, bis [4- (meth) acryloyloxyethoxy-3,5-
Dimethylphenyl] -sulfide, bis (4- (meth)
Sulfur-containing compounds such as acryloyloxyethoxyphenyl) sulfone; and polyfunctional (meth) acrylate compounds such as di [(meth) acryloyloxyethoxy) phosphate and tri [(meth) acryloyloxyethoxy] phosphate.

The active energy ray-curable resin composition for cast polymerization of the present invention may be used in combination with another resin (e) for the purpose of improving the viscosity and adhesion to a transparent substrate.

Other resins (e) include, for example, acrylic resins such as methyl methacrylate resin and methyl methacrylate copolymer; polystyrene, methyl methacrylate-styrene copolymer; polyester resin, polybutadiene and butadiene-acrylonitrile copolymer. Polybutadiene resins such as polymers; and epoxy resins such as bisphenol-type epoxy resins, phenoxy resins and novolak-type epoxy resins.

When the other resin (e) is a resin having an unsaturated double bond in the main chain skeleton, such as a polybutadiene resin or an unsaturated polyester resin, the unsaturated group is a resin composition of the present invention. This is preferable because it reacts at the time of the curing reaction and is taken into the cured product, so that the thermoplastic resin component hardly changes over time. A polyester resin having a bisphenol A and / or bisphenol F skeleton is suitable because the resulting rigidity and high refractive index are not impaired.

The amount of the other resin (e) used is a total of 1 in the active energy ray-curable resin composition for cast polymerization of the present invention.
1 to 30 parts by weight is preferable with respect to 00 parts by weight.

The refractive index after curing of the active energy ray-curable composition for cast polymerization of the present invention comprising the above-mentioned components is sufficient for producing optical parts, lenses and lens sheets as articles. It is preferably 1.54 or more in order to obtain an effect of improving the brightness and to make the lens shape shallower to improve the releasability from the mother die.

The viscosity of the active energy ray-curable resin composition for cast polymerization of the present invention is set so that the resin composition can be uniformly applied to a matrix, and that a matrix having a fine structure can be reproduced. At 25 ° C, 1000 to 30000 mPa
s, preferably 1000 to 2
It is particularly preferable that it is 0000 mPa · s. Even if the viscosity is out of the above range, the viscosity can be adjusted by controlling the temperature of the resin composition and the like, and can be used.

The active energy ray-curable resin composition for cast polymerization of the present invention can be cured using an active energy ray. The active energy ray means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing and crosslinking molecules, for example, visible light, ultraviolet light, X
An electromagnetic wave such as a beam or a charged particle beam such as an electron beam can be used. Of these, visible light, ultraviolet light, or electron beam is often used in practice.

In the case of ultraviolet rays, a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a black light lamp, and a metal halide lamp can be used. As the ultraviolet wavelength, a wavelength range of usually 1900 to 3800 angstroms is mainly used.

In the case of curing by visible light or ultraviolet light, a photo (polymerization) initiator which dissociates and generates radicals by ultraviolet light or visible light having a wavelength of 1,000 to 8,000 angstroms is used in the present invention. Contained in the resin composition.

As such a photo (polymerization) initiator, various photopolymerization initiators which dissociate by light to generate radicals can be used. For example, benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 4,4'-bisdimethylaminobenzophenone, 4,4'-bisdiethylaminobenzophenone, 4,4'-dichlorobenzophenone, Michler's ketone, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, etc. Benzophenones; xanthone, thioxanthone,
Xanthones such as 2-methylthioxanthone, 2-chlorothioxanthone, and 2,4-diethylthioxanthone; thioxanthones; acyloin ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether; α- such as benzyl and diacetyl; Diketones; sulfides such as tetramethylthiuram disulfide and p-tolyl disulfide; benzoic acids such as 4-dimethylaminobenzoic acid and ethyl 4-dimethylaminobenzoate;

Further, 3,3'-carbonyl-bis (7-diethylamino) coumarin, 1-hydroxycyclohexyl phenyl ketone, 2,2'-dimethoxy-
1,2-diphenylethan-1-one, 2-methyl-1
-[4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1-
On, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 1-
[4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 1-
(4-Isopropylphenyl) -2-hydroxy-2-
Methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4-benzoyl-4'-methyldimethylsulfide, 2,2'-diethoxyacetophenone, benzyl Dimethyl ketal, benzyl-β-methoxyethyl acetal, methyl o-benzoyl benzoate, bis (4-dimethylaminophenyl) ketone, p-dimethylaminoacetophenone, α, α-dichloro-4-phenoxyacetophenone, pentyl- 4-dimethylaminobenzoate, 2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer, 2,4-bis-trichloromethyl-6- [di- (ethoxycarbonylmethyl) amino] phenyl-S-triazine , 2,4-bis-trichloromethyl-6- (4-ethoxy Phenyl-S-triazine, 2,4-bis-trichloromethyl-6- (3-bromo-4-ethoxy) phenyl-S-triazineanthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone and the like Are also mentioned.

Commercially available photo (polymerization) initiators include:
For example, Irgacure-184, 149, 261 and 3
69, 500, 651, 784, 819, 9
07, 1116, 1664, 1700, 180
0, 1850, 2959, 4043, Darocur-1
173 (manufactured by Ciba Specialty Chemicals), Lucirin TPO (manufactured by BASF), KAYACURE-DETX, MBP, DM
BI, EPA, OA (Nippon Kayaku Co., Ltd.), VICURE-10,
55 (STAUFFER Co. LTD), TRIGONALP1 (AKZO C
o.LTD), SANDORY 1000 (SANDOZ Co.LTD), DEAP
(APJOHN Co. LTD), QUANTACURE-PDO, ITX, EPD
(Made by WARD BLEKINSOP Co.LTD), etc.

Further, various photosensitizers can be used in combination with the photopolymerization initiator. Examples thereof include amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitriles and other nitrogen-containing compounds. And the like.

Specifically, for example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-
Hydroxyethoxy) phenyl] -2-hydroxy-2
-Methyl-1-propan-1-one, thioxanthone and thioxanthone derivatives, 2,2'-dimethoxy-
1,2-diphenylethan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2-methyl-1- [4- (methylthio) Phenyl] -2-morpholino-1-propanone, 2
One or a mixture of two or more selected from the group of -benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one is particularly preferred because high curability is obtained.

These photosensitizers can be used alone or in combination of two or more. The amount used is not particularly limited, but is preferably 0 to 100 parts by weight of the active energy ray-curable resin composition for casting polymerization in order to maintain good sensitivity, prevent precipitation of crystals, deterioration of coating film properties, and the like. .05-2
It is preferable to use 0 parts by weight, especially 0.1 to 10 parts by weight.
Part by weight is particularly preferred.

In the production of an article using the active energy ray-curable resin composition for cast polymerization of the present invention, active energy rays such as ultraviolet rays are often irradiated through the surface of a transparent substrate serving as a support. . Therefore, the photoinitiator is preferably an initiator having a light absorbing ability in a long wavelength region, for example,
It is desirable to use a photoinitiator that exhibits a photoinitiating ability in the range of 360 to 450 nm of ultraviolet light. Those having strong absorption even with light of 450 nm or more have poor stability of the composition, require production in a completely light-shielded environment, and are extremely difficult to handle. When an electron beam is used, these photoinitiators and photosensitizers are unnecessary.

In the case of an electron beam, a Cockloft-Walton type, a bandeograph type, a resonance transformer type, an insulating core transformer type,
Alternatively, an apparatus equipped with an irradiation source such as various electron beam accelerators such as a linear type, a dynamitron type, and a high frequency type can be used, and 100 to 1000 KeV, preferably 100 to 1000 KeV.
Irradiate with electrons having an energy of 00 KeV. The irradiation dose is usually preferably about 0.5 to 30 Mrad.

The active energy ray-curable resin composition for cast polymerization according to the present invention may optionally contain an ultraviolet absorber when the cured resin molding layer formed on the substrate is required to have light resistance. Can be added. Furthermore, in order to improve the coating film, improve the coating suitability, and improve the releasability from the matrix, antioxidants, silicon-based additives, fluorine-based additives, rheology control agents, defoamers, release agents It is also possible to add a silane coupling agent, an antistatic agent, an anti-fogging agent, a coloring agent and the like.

As the ultraviolet absorber, for example, 2- [4
-｛(2-hydroxy-3-dodecyloxypropyl)
Oxy {-2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-{(2-hydroxy-3-tridecyloxypropyl) oxy {-2-hydroxyphenyl]-
4,6-bis (2,4-dimethylphenyl) -1,3
Triazine derivatives such as 5-triazine, 2- (2'-
Xanthenecarboxy-5'-methylphenyl) benzotriazole, 2- (2'-o-nitrobenzyloxy-
5'-methylphenyl) benzotriazole, 2-xanthencarboxy-4-dodecyloxybenzophenone,
2-o-nitrobenzyloxy-4-dodecyloxybenzophenone and the like.

Examples of the antioxidant include 4,4 'methylenebis (2,6-t-butylphenol),
2'-methylenebis- (4-methyl-6-t-butylphenol), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 1,1,3-tris (2-methyl-5-
t-butyl-4-hydroxyphenyl) propane, 2,
2′-ethylidenebis- (4,6, -di-t-butylphenol), triethylene glycol bis-3- (t-
Butyl-4-hydroxy-5-methylphenyl) propionate, 3- (3 ', 5'-di-tert-butyl-4'-
Hydroxyphenyl) octadecyl propionate, 2,
2'-methylenebis- (4-ethyl-6-t-butylphenol, pentaerythrityl-tetrakis- {3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate｝, 2,6-di-t-butyl-4-methylphenol, 6- (3'-t-butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenylacrylate-t-butyl , 4,4'-butylidenebis-
(3-methyl-6-t-butylphenol), tetrakis-dimethylene-3- (3 ', 5'-di-t-butyl-
4'-hydroxyphenyl) propionate methane,
N. N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxyhydrocinnamamide), 1,6-
Hexanediol bis-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate,
2,2'-thiodiethylbis- {3- (3 ', 5'-t
Hindered phenolic compounds such as -butyl-4-hydroxyphenyl) propionate {, 4,4'-thiobis (3-methyl-6-t-butylphenol);
Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 1- [2- {3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionyloxy {ethyl} -4- {3- (3,5-
Di-tert-butyl-4-hydroxyphenyl) propionyloxy {-2,2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3
-Octyl-1,3,8-triazaspin [4,5] undecane-2,4-dione, 4-benzoyloxy-
Hindered amine compounds such as 2,2,6,6-tetramethylpiperidine; organic sulfur compounds such as dilauryldithiopropionate and pentaerythritol-tetrakis- (3-laurylthiopropionate);
Phosphate esters such as 5-di-t-butyl-4-hydroxybenzyl phosphate diethyl ester and 3,5-di-t-butyl-4-hydroxybenzyl phosphate dioctadecyl ester are exemplified.

As the silicon-based additive, for example, dimethylpolysiloxane, methylphenylpolysiloxane,
Cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, fluorine-modified dimethylpolysiloxane copolymer,
Examples thereof include polyorganosiloxanes having an alkyl group or a phenyl group, such as an amino-modified dimethylpolysiloxane copolymer.

The amount of each of the various additives as described above is within a range in which the effect is sufficiently exhibited and the ultraviolet curing is not hindered. Therefore, 100% by weight of the active energy ray-curable resin composition for casting polymerization is used. Parts for each
It is preferably in the range of 1 to 5 parts by weight.

The active energy ray-curable resin composition for cast polymerization of the present invention can be applied to various articles having a structure in which a molded resin layer made of a cured resin on a film-shaped, sheet-shaped, or plate-shaped transparent substrate is provided. Suitable material. Above all, when used for the manufacture of articles requiring transparency, such as optical parts and lenses, a cured product having a thickness of 200 ± 25 μm has a thickness of 400 to 9 μm.
It is preferable to use each resin composition component in combination so that the light transmittance in the wavelength region of 00 nm is 80% or more, preferably 85% or more.

For these articles, for example, the active energy ray-curable resin composition for cast polymerization of the present invention is applied on a matrix having a required fine shape, and a support and a support are formed on the layer. The resin composition is cured by adhering a transparent substrate, and then irradiating an active energy ray from the transparent substrate surface to cure the resin composition, and then peeling the resin composition from the matrix.

Examples of the film-like, sheet-like, and plate-like transparent base materials usable herein include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), triacetyl cellulose, polycarbonate resins, and the like. An acrylic resin such as a methyl methacrylate copolymer, a styrene resin, a polysulfone resin, a polyethersulfone resin, a polycarbonate resin, a vinyl chloride resin, a polymethacrylimide resin, and the like are included. Also, although not a plastic substrate,
Inorganic substrates such as glass substrates can be used as well.

[0073]

Next, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention should not be limited to these. All parts and percentages in the examples are based on weight unless otherwise specified.

(Examples 1 to 7 and Comparative Examples 1 to 3) The active energy ray-curable resin compositions for cast polymerization were prepared according to the formulations shown in Table 1.

(Formation of Cured Film) The obtained active energy ray-curable resin composition was placed between a chromium-plated metal plate and a transparent surface-untreated PET film, and the thickness was adjusted. After irradiating 800 mJ / cm 2 of ultraviolet light from the transparent substrate side to cure the resin, the active energy ray-curable resin layer is peeled off from the metal plate and the transparent substrate, and the surface has a smooth thickness of 200 ± 25 μm. A resin film (F) was produced.

The obtained active energy ray-curable resin composition was placed between a chromium-plated metal matrix having a 120-μm width and a 100-μm height having a repeating chevron shape and a transparent easy-adhesion-treated PET film as a transparent substrate. It was cured by irradiating it with ultraviolet light of 800 mJ / cm 2 from the transparent substrate side using an ultra-high pressure mercury lamp. After UV curing, the PET film with the transparent easy-adhesion treated PET film peeled off from the metal matrix together with the active energy ray-curable resin layer, and the required shape was transferred.
A cured product (L) with a film shape was produced.

The obtained active energy ray-curable resin composition was put between a chromium-plated metal plate and an acrylic resin plate, and the thickness thereof was adjusted.
mJ / cm ² ultraviolet rays are irradiated from the transparent substrate side to cure, the transparent substrate is peeled off from the metal plate together with the active energy ray-curable resin layer, and the transparent substrate is cured to a thickness of 200 ± 25 μm with a smooth surface. An acrylic resin plate smooth cured product (S) having a resin layer was produced.

(Evaluation Method) Using these active energy ray-curable resin compositions and cured products, evaluation was performed according to the following measurement and test methods. In addition, about the active-energy-ray-curable resin composition of Example 2, the viscosity was reduced in the state heated at 50 degreeC, and each test sample was created. The evaluation results are shown in Table 1, Table 2 (1), and Table 2 (2). FIG. 1 shows the dynamic viscoelasticity measurement results obtained in Example 1. FIG. 2 shows the results of measurement of the dynamic viscoelasticity obtained in Comparative Example 1. These are shown as an example of the measurement results in all Examples and Comparative Examples.

(1) Viscosity measurement: The viscosity of the resin composition adjusted by the formulation shown in Table 1 was measured at 25 ° C. (mPa · s) using an E-type rotational viscometer.

(2) Refractive index: A liquid sample and a cured sample were measured. The liquid sample was directly applied to a prism of an Abbe refractometer and measured at 25 ° C. The cured sample was a cured resin film (F). 1-bromonaphthalene was used as an intermediate solution for bringing the sample into close contact with the prism, and the sample temperature was 25 ° C. with an Abbe refractometer.
Was measured.

(3) Dynamic viscoelasticity measurement: Using a solid viscoelasticity measuring apparatus RSA-2 (manufactured by Rheometrics) using a strain control method, using the cured resin film (F) as a sample,
Size 6 × 35mm, frequency 1Hz, load distortion 0.05
%, Heating rate 3 ° C / min, measuring temperature -50 ° C to 150 ° C
-30 ° C to 120 ° C out of the data measured under the conditions of
From the data obtained in the temperature range up to [T (ma
x)], [Tan δ (max)], [ΔT (0.1)]
And [E ′ (Tmax + 40 ° C.)].

(4) Transparency: Using the cured resin film (F), the light transmittance in the wavelength region of 400 to 900 nm was measured.
Those with a transmittance lower than that were rated as x.

(5) Adhesion: The adhesion between the transparent substrate and the cured resin layer was measured in accordance with JIS K5400 using the acrylic resin plate smooth cured product (S). 95/100
The time when the above-mentioned squares remained was indicated by ○, the time when 60/100 or more squares remained was indicated by Δ, and the time when it was less than 60/100 was indicated by ×.

(6) Judgment of appearance: The appearance of the cured product (L) having a PET film shape was visually judged. Judgment criteria were those where a uniform surface shape was obtained, 、, those in which cracks and shape omissions were seen in some parts, and those in which cracks and shape omissions were seen over the entire surface were evaluated as ×. .

(7) Shape holding force: On a smooth metal plate,
5cm x 5cm of cured product (L) with PET film shape
The test piece cut out in the above manner is placed horizontally so that the cured resin layer is on the upper side, and the bottom is flat from above (weight 15).
0 g), and evenly applied at a temperature of 25 ° C. and 40 ° C. for 60 minutes. Subsequently, the load was removed, and the presence or absence of deformation marks on the cured product (L) with the PET film shape was visually determined. As a criterion for the shape retention force, ○ indicates that no trace of deformation was confirmed on the sheet, and X indicates that a trace of deformation was confirmed on the sheet.

(8) Chipping / cracking resistance: When a cut is made in the PET film-shaped cured product (L) in the direction intersecting with the chevron shape using a cutter knife, the cured resin layer is chipped or cracked. Was evaluated as ○ when there was no 、, and × when chipping or cracking occurred.

(9) Light resistance: The cured resin layer side was irradiated with an ultraviolet fade meter (black panel temperature: 63 ° C.) for 200 hours using an acrylic resin plate smooth cured product (S). Next, using a color difference meter (ZE2000) manufactured by Nippon Denshoku, the degree of yellowing (ΔYI) before and after irradiation was calculated from the XYZ values, and when the value indicating the difference was less than 5, the result was ◎. , And the case of 10 or more was evaluated as x.

[0088]

[Table 1]

<Footnotes to Table 1> (a-1) Epoxy acrylate obtained by reacting bisphenol A type epoxy resin (epoxy equivalent 640 g / eq) with acrylic acid (a-2) Bisphenol A type epoxy resin (epoxy equivalent 190 g) / Eq) and an acrylic acid obtained by reacting acrylic acid (b-1) tripropylene glycol diacrylate (b-2) polypropylene glycol (molecular weight of about 40
0) Diacrylate (b-3) Triacrylate of polyhydric alcohol obtained by adding about 3 mol of propylene oxide to trimethylolpropane (b-4) Polyethylene glycol (molecular weight: about 200)
Diacrylate (c-1) Acrylate of paracumylphenol obtained by addition reaction of about 1 mol of ethylene oxide (c-2) Phenoxyethyl acrylate (c-3) Benzyl methacrylate (c-4) 2,4,6-tribromophenoxy Ethyl acrylate (c-5) 2,3-carbonate propyl methacrylate (glycidyl cyclocarbonate methacrylate) (ultraviolet absorber) 2- [4-{(2-hydroxy-3-
Dodecyloxypropyl) oxy {-2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl)
-1,3,5-triazine (photoinitiator) 1-hydroxycyclohexyl phenyl ketone

[Table 2]

[0090]

[Table 3]

[0091]

According to the present invention, the molded resin layer formed on the transparent substrate has excellent shape holding power over a wide temperature range, and has a lack of shape due to external force. An excellent active energy ray-curable resin composition for cast polymerization can be provided, which hardly causes cracks and has no problems with other required characteristics.

[0092]

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing dynamic viscoelasticity measurement results. The vertical axis represents the storage elastic modulus (E ′) and the tangent of the mechanical loss, and the horizontal axis represents the temperature (° C.). (This is the result of measurement using the resin composition of Example 1.)

FIG. 2 is a schematic diagram showing dynamic viscoelasticity measurement results. The vertical axis represents the storage elastic modulus (E ′) and the tangent of the mechanical loss, and the horizontal axis represents the temperature (° C.). (This is the result of measurement using the resin composition of Comparative Example 1.)

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yasunobu Hirota 1-27-1 Osakidai, Sakura City, Chiba Prefecture (72) Inventor Masanobu Funatsu 1863-10, Noman, Ichihara City, Chiba Prefecture (72) Inventor Hidenobu Ishikawa Chiba City 6-5-4 Haraichi Wakamiya F term (reference) 4J011 GA05 GB07 GB08 4J027 AC03 AC04 AC06 AE02 AE06 BA07 BA08 BA13 BA15 BA16 BA19 BA20 BA21 BA23 BA26 BA28 CA02 CA03 CA06 CA08 CA10 CB10 CC04 CC05 CC06 CC08 CD01 CD04

Claims (4)

[Claims] 1. An epoxy (meth) acrylate (a) having two or more (meth) acryloyl groups, a (meth) acrylate compound of an aliphatic polyhydric alcohol (b), and a monofunctional (meth) acrylate (C) is an active energy ray-curable resin composition containing, as an essential component, the maximum of the mechanical loss tangent by dynamic viscoelasticity measurement at a frequency of 1 Hz of a cured product cured by irradiation with active energy rays. Temperature [T (max)] is 50 ° C. or more, the maximum value of the mechanical loss tangent [Tan δ (max)] is 0.7 to 2.0, and the mechanical loss tangent value is 0.1. The storage modulus [E '(Tmax) at a temperature where the temperature difference [ΔT (0.1)] at two points is 60 ° C. or less and 40 ° C. higher than the temperature [T (max)] at which the maximum value of the mechanical loss tangent is obtained.
+ 40 ° C.)], but from 5.0 × 10 ^{6 to} 2.0 × 10 ⁷ Pa
An active energy ray-curable resin composition for cast polymerization, characterized by being: 2. The temperature [T which indicates the maximum value of the mechanical loss tangent
(Max)] is 50 to 70 ° C., the maximum value of the mechanical loss tangent [Tan δ (max)] is 0.8 to 1.5, and the temperature difference between the two points is 0.1. [ΔT (0.
1)] is 35 to 45 ° C. and the storage elastic modulus [E ′ (Tmax + 40 ° C.)] at a temperature 40 ° C. higher than the temperature [T (max)] at which the maximum value of the mechanical loss tangent is 1.0 × 1.0 ×
The active energy ray-curable resin composition for casting polymerization according to claim 1, which has a pressure of 10 ^{7 to} 2.0 × 10 ⁷ Pa. 3. Epoxy (meth) acrylate (a)
Has a cyclic structure and an average epoxy equivalent of 450 g / e
q or more epoxy resins (a ') obtained by the reaction of (meth) acrylic acid with an epoxy resin, wherein the (meth) acrylate compound (b) of an aliphatic polyhydric alcohol has an aliphatic structure having a propylene oxide structure (Meth) acrylic acid ester compound (b ') of a polyhydric alcohol, wherein the monofunctional (meth) acrylate (c) is a monofunctional (meth) acrylate (c') having a cyclic structure
And (a ′), (b ′), and (c ′) in a total of 100 parts by weight, the epoxy (meth) acrylate (a ′) is 30 to 70 parts by weight, and the aliphatic polyhydric alcohol ( (Meth) acrylic acid ester compound (b ') is 5 to 40
5 parts by weight of monofunctional (meth) acrylate (c ')
The active energy ray-curable resin composition for cast polymerization according to claim 1 or 2, which contains 5 parts by weight as an essential component. 4. The active energy ray-curable resin composition for cast polymerization according to claim 1, wherein the cured product cured by irradiation with the active energy ray has a refractive index of 1.54 or more.