JP2013018910A - Resin cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin cured product excellent in toughness and high in scratch resistance.SOLUTION: The resin cured product (1), on the surface of which a fine uneven structure (10) is formed, comprises a cured product of polyethyleneglycol di (meth)acrylate and urethane di(meth)acrylate and has surface elasticity of 0.01 to 2 GPa and surface hardness of 0.01 to 0.2 GPa.

Description

  The present invention relates to a cured resin material having excellent antireflection performance and excellent scratch resistance in a wide wavelength range from visible to near infrared and a wide incident light angle range.

  It is known that antireflection materials such as antireflection films or antireflection films have the effect of reducing the surface reflection of a substance, improving the efficiency of taking light into the substance, and improving the visibility from the outside. ing. For example, in various optical panels such as a liquid crystal television screen of a game machine, an antireflection film is provided on the surface of the optical panel or an internal member, whereby external light reflection is reduced and an image can be clearly seen. Moreover, when an antireflection film is attached to the solar cell panel, the daylighting property is improved, which greatly contributes to the improvement of power generation efficiency. As described above, since the antireflection material efficiently transmits light information and light energy to various media, it greatly contributes to comfortable living and energy saving.

  In general, as the antireflection film, a single layer AR (antireflection) that cancels light by utilizing interference of light and a multilayer AR are widely known. In particular, the latter is less likely to cause RGB color spots in the transmitted light and has good visibility. However, since the optical path length of the single-layer AR and the multilayer AR varies depending on the incident angle, the wavelength band that can be anti-reflective varies and the anti-reflection effect is reduced. In recent years, as a new antireflection film, an antireflection film having a fine concavo-convex structure (moth eye structure) imitating the surface concavo-convex structure of the eyelet has been reported. The moth-eye structure is a continuous fine concavo-convex structure having a pitch smaller than the wavelength of visible light, and a continuous refractive index gradient can be formed at the interface between the gas layer and the solid layer, thereby preventing interface reflection (Non-Patent Document 1). ). In addition, even if the incident angle is changed, the same effect can be confirmed, and a single layer exhibits excellent antireflection characteristics. Therefore, it is expected as a next-generation antireflection material.

  On the other hand, a fine concavo-convex structure having a pitch smaller than the wavelength of visible light has a drawback that it is geometrically very fragile and fragile. In particular, when a concavo-convex structure with a high aspect ratio is produced in order to improve the antireflection performance, it becomes physically weaker. For this reason, there is a demand for the development of a resin that exhibits scratch resistance even in a fine uneven structure. As a prior art, a hard resin using a polyfunctional acrylic resin (Patent Document 1) and an optical element using a soft resin (Patent Document 2) have been proposed.

JP 2011-000856 A JP 2011-076072 A

Nature 244,281-282 (03 August 1973) Reduction of Lens Reflexion by the "Moth Eye" Principle, P.B.CLAPHAM & M.C.HUTLEY

  However, the hard resin described in Patent Document 1 shows a certain scratch resistance, but in the case of a concavo-convex structure with a high aspect ratio, it is difficult to impart toughness, and it is often hard and brittle. In addition, the soft type resin described in Patent Document 2 is attractive in that it can relieve stress. However, when a wiping operation is performed on the surface of the optical element, the surface has a fine uneven structure. It often breaks, and it is difficult to say that scratch resistance is good overall.

  This invention is made | formed in view of this point, and it aims at providing the resin hardened | cured material with high toughness while being excellent in toughness.

  The cured resin product of the present invention is a cured resin product having a fine concavo-convex structure formed on the surface thereof, and includes a cured product of polyethylene glycol di (meth) acrylate and urethane di (meth) acrylate, and has a surface elastic modulus of 0.01 GPa. It is 2 GPa or less and the surface hardness is 0.01 GPa or more and 0.2 GPa or less.

  According to this configuration, since the cured resin contains polyethylene glycol di (meth) acrylate, the extensibility is improved, and since urethane di (meth) acrylate is included, the extensibility and elasticity are improved. As a result, the toughness and the restoring force against elongation are improved, and a cured resin with high scratch resistance can be realized.

  The cured resin of the present invention preferably contains at least one of a silicone-based additive and a fluorine-based additive.

  In the resin cured product of the present invention, the number of polymerizable functional groups of the cured product is preferably 2 or less.

  In the resin cured product of the present invention, it is preferable that 10 parts by mass to 500 parts by mass of the urethane di (meth) acrylate is included with respect to 100 parts by mass of the polyethylene glycol di (meth) acrylate.

  In the resin cured product of the present invention, it is preferable that N-vinylpyrrolidone is contained in an amount of more than 0 parts by mass and less than 500 parts by mass with respect to 100 parts by mass of the polyethylene glycol di (meth) acrylate.

  In the resin cured product of the present invention, the fine concavo-convex structure has a pitch between adjacent convex portions of 100 nm or more and 1000 nm or less, and an aspect ratio of the concave portions or the convex portions of 0.1 or more and 2.5 or less. Preferably there is.

  In the cured resin of the present invention, it is preferable that the concave portions or convex portions of the fine concavo-convex structure are arranged in a hexagonal lattice shape in plan view.

  In the cured resin product of the present invention, ((reflectance after scratch test−reflectance before scratch test) / reflectivity before scratch test) × 100 in the entire visible range is preferably 60% or less.

  The optical element of the present invention comprises a base material and a resin layer provided on the base material and containing the resin cured product.

  According to the present invention, it is possible to provide a cured resin having excellent toughness and high scratch resistance.

It is a cross-sectional schematic diagram of the resin cured material which concerns on this Embodiment. It is the electron micrograph which expanded a part of fine concavo-convex structure concerning this embodiment. It is a photograph which shows the arrangement pattern of the fine uneven structure of the resin cured material which concerns on this Embodiment. It is a cross-sectional schematic diagram which shows an example of the optical element which concerns on this Embodiment. It is a cross-sectional schematic diagram which shows the other example of the optical element which concerns on this Embodiment. It is a photograph which shows the result of the wiping test (scratch resistance evaluation) using the bemcot with ethanol which concerns on an Example. It is a photograph which shows the result of the steel wool test (scratch resistance evaluation) which concerns on an Example. It is a scanning electron micrograph which shows the result which concerns on an Example. It is a figure which shows the reflectance before and behind the touch pen scratch test which concerns on an Example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

(Cured resin)
FIG. 1 is a schematic cross-sectional view of a cured resin 1 according to an embodiment of the present invention. As shown in FIG. 1, the cured resin 1 according to the present embodiment has a fine concavo-convex structure 10 molded on the surface. The fine concavo-convex structure 10 has a plurality of convex portions 11 and concave portions 12 provided so as to continuously extend in an in-plane direction (left-right direction and depth direction in FIG. 1) of the reference surface X of the cured resin 1. (See FIG. 2). Further, the fine concavo-convex structure 10 forms an array pattern having arbitrary regularity by a plurality of convex portions 11 and a plurality of concave portions 12 in a plan view from a vertical direction orthogonal to the reference plane X of the cured resin 1. To do. In addition, in FIG. 1, the convex part 11 which protrudes upwards from the reference plane X of the resin cured material 1 and the recessed part 12 which was provided between each convex part 11 and was depressed in the reference plane X side from each convex part 11 are shown. Although the example of the fine concavo-convex structure 10 provided repeatedly is shown, a concave portion 12 recessed downward from the reference plane X, and a convex portion 11 provided between the concave portions 12 and protruding from the bottom of each concave portion toward the reference plane X side It is good also as the fine concavo-convex structure 10 which provided repeatedly.

  In the cured resin 1 according to the present embodiment, the concave portions 12 or the convex portions 11 having a fine concavo-convex structure are preferably arranged in a hexagonal lattice shape in plan view. As a result, the occupancy ratio of the concavo-convex structure that creates a refractive index gradient is the highest (closest packed), so that the antireflection function is improved. FIG. 3 shows an example of an arrangement pattern of the protrusions 11 of the fine concavo-convex structure 10 arranged in a hexagonal lattice pattern. As shown in FIG. 3, the hexagonal lattice-like arrangement pattern means that, in a plan view from the direction perpendicular to the reference plane X, with respect to any one convex portion 11 of the fine concavo-convex structure 10, There are six closest protrusions 11, and the six protrusions 11 form a hexagonal shape 21. In FIG. 3, a region (ridge 22) that is provided in a region between the convex portion 11 and the concave portion 12 and has an intermediate height H between the height H of the convex portion 11 and the height H of the bottom of the concave portion 12. ) Is also shown. As an array pattern of the convex portions 11 or the concave portions 12 of the fine concavo-convex structure 10, there are four convex portions 11 closest to the convex portion 11 for any one convex portion 11, and the four It may be a tetragonal lattice-like arrangement pattern that forms a quadrangular shape by the convex portions 11, or a random pattern having no regularity in the arrangement of the convex portions 11.

  In the cured resin 1 according to the present embodiment, the pitch P between the convex portions 11 adjacent to each other is 100 nm or more and 1000 nm or less, and the aspect ratio between the pitch P and the height H of the convex portion 11 (concave portion 12). Is preferably 0.1 or more and 2.5 or less. If the pitch P satisfies the above range and the aspect ratio is 0.1 or more, the optical characteristics of the fine concavo-convex structure 10 are sufficiently exhibited, so that the antireflection function can be improved and the aspect ratio is 2.5 or less. If so, the physical strength is stabilized against external stresses such as scratches, and the peelability from the stamper can be maintained when the cured resin 1 is produced, and the productivity of the cured resin 1 is improved. In the present specification, the “projection (or recess) height H” refers to the distance from the reference plane X in the direction perpendicular to the reference plane X of the cured resin 1 to the apex of the projection 11 (or the bottom of the recess). Distance.

  The shape of the continuous structure of the fine concavo-convex structure 10 is not particularly limited as long as it is a continuous structure including the concave portions 11 and the convex portions 12 and can obtain the effects of the present invention. Examples of the type of continuous structure include a line and space structure, a dot structure, a honeycomb structure, and a moth eye structure. Among these, in order to obtain high antireflection performance, it is preferable to apply a moth-eye structure which is one of dot structures.

  Moreover, it is preferable that the shape of the convex part 11 and the recessed part 12 of the fine concavo-convex structure 10 is any one of a substantially pyramid shape, a substantially cone shape, a substantially truncated cone shape, and a substantially truncated cone shape. Among these, a substantially pyramid shape and a substantially conical shape are more preferable, and a substantially conical shape is more preferable. The substantially conical shape may be a true cone or an elliptical cone, and preferably has a round top. Antireflection performance can be improved by further rounding the top as a substantially conical shape. Examples of the substantially conical shape include a tent shape (a shape in which the ridge line of the convex portion is dented), a bell shape ((a shape in which the ridge line of the convex portion swells), and a triangular shape ((a shape in which the ridge line of the convex portion is a straight line). The bell type is more preferable in that an excellent antireflection performance can be obtained in a wide wavelength region, particularly in the near infrared wavelength region (700 to 1000 nm).

(Surface elastic modulus and surface hardness)
In the cured resin 1 according to the present embodiment, the surface elastic modulus and surface hardness were measured using a nanoindenter device (manufactured by MTS) and analyzed using NanoIndenter attached software Analyst (manufactured by MTS). Modulus is the surface elastic modulus and Hardness is the surface hardness. The surface elastic modulus and surface hardness are values measured in the range of several hundred nm to several μm in the depth direction from the surface of the cured resin 1, and are defined as values obtained by measuring at least 10 points and calculating the average value.

  The cured resin 1 according to the present embodiment has a surface elastic modulus of 0.01 GPa or more and 2 GP or less. If the surface elastic modulus is 0.01 GPa or more, for example, even when the surface of the cured resin 1 is rubbed with a wounded body such as a fiber body (tissue, cloth, etc.), the fine concavo-convex structure 10 is damaged and the resin is cured. Abrasion to the surface of the object 1 can be suppressed. Further, if the surface elastic modulus is 0.1 GP or more, even when the surface of the cured resin 1 is rubbed with a resin-made wound body such as a touch pen, the fine uneven structure 10 is damaged and the surface of the cured resin 1 is obtained. Can be suppressed. Further, the upper limit value of the surface elastic modulus is not particularly limited. For example, if it is 2 GPa or less, the load from the external stress can be sufficiently dispersed, so that the scratch on the surface of the cured resin 1 can be suppressed, and 1.5 GPa If it is below, even when an external stress is applied for a long time, scratches on the surface of the cured resin 1 can be suppressed. Furthermore, if it is 1 GPa or less, it is possible to suppress deep scratches caused by a heavily damaged wound body.

  The cured resin 1 according to the present embodiment has a surface hardness of 0.01 GPa or more and 0.2 GPa or less. If the surface hardness is 0.01 GPa or more, even when the surface of the cured resin 1 is rubbed with a fibrous wound body, scratches on the surface of the cured resin 1 can be suppressed. Moreover, if the surface hardness is 0.02 GPa or more, even when the surface of the cured resin 1 is rubbed with a scratched resin body such as a touch pen, scratches on the surface of the cured resin 1 can be suppressed. If the surface hardness is 0.2 GPa or less, it is possible to sufficiently disperse the load from the external stress. Therefore, scratches on the surface of the cured resin 1 can be suppressed, and if it is 0.15 GPa or less, external stress is applied for a long time. Even in such a case, scratches on the surface of the cured resin 1 can be suppressed. Furthermore, if it is 0.1 GPa or less, it is possible to suppress deep scuffing caused by a heavily damaged wound body.

  Furthermore, in the cured resin 1 according to the present embodiment, the surface elastic modulus of the cured resin 1 is 0.01 GPa or more and 2 GPa or less, and the surface hardness is 0.01 GPa or more and 0.2 GPa or less. It is preferable in that it is a flexible resin that has excellent folding resistance and is easy to process, and exhibits elastic properties with scratch resistance. Furthermore, when the surface elastic modulus is 0.1 GPa or more and 1 GPa or less and the surface hardness is 0.02 GPa or more and 0.1 GPa or less, the load can be reduced even for a long time deep scratch and the wound is recovered. It is more preferable at the point which shows a quick elasticity.

(Compounding guidelines for soft resin materials)
The cured resin 1 preferably contains a resin material that is soft and slippery and has a good restoring force against elongation in order to prevent the resin cured product 1 from being permanently deformed when subjected to an external stress load. . As the soft resin material, (1) a resin material having flexibility, toughness, and surface elasticity is preferable, and a composition that exhibits these physical properties in a well-balanced manner is selected. For example, when the polymer main chain partially contains a highly flexible molecular chain such as an ethylene oxide (hereinafter abbreviated as “EO”) chain or a propylene oxide (hereinafter abbreviated as “PO”) chain, It shows flexible elasticity as a macroscopic physical property. Next, (2) by providing a non-covalent cross-linking point between polymer chains, it is possible to disperse external stress, and to develop toughness properties that can withstand permanent deformation in addition to flexibility. For example, a hydrogen bond group represented by amide, urethane, ester group or the like is included in the molecular structure. Furthermore, (3) it is also effective to reduce the crosslinking density in order to prevent local stress concentration with respect to external stress. For example, in the cured resin 1 according to the present embodiment, the polymer network size after curing can be increased by setting the number of polymerizable functional groups to 2 or less, or by selecting a composition having a large molecular weight. Can be relaxed. Moreover, (4) Elongation improves by containing the continuous EO chain | strand in a main component. Further, by containing the urethane skeleton at the same time, the restoring force against elongation is further improved.

  In addition to the above resin physical properties, it is more preferable to provide (5) resin surface slipperiness. The external stress is easy to diverge in the horizontal direction, and is effective in that the stress in the vertical direction on the cured resin layer surface can be reduced. Specifically, the surface of the cured resin 1 is modified by using a silicone or fluorine silane coupling agent, or a silicone additive or fluorine additive is added to the resin composition 1 in advance. Then, the method of hardening resin etc. is mentioned.

  Furthermore, from the viewpoint of productivity, the resin preferably has a composition suitable for (6) an optical nanoimprint process capable of forming the fine relief structure 10 quickly and continuously. Specifically, a composition in which a photoinitiator is mixed is preferable, and a composition in which a photoradical initiator having a high reaction rate is mixed is more preferable. In order to prevent surface damage of the cured resin 1 when the cured resin 1 is peeled from the mold, (7) it is preferable to add a release agent to the resin. Examples of the release agent include silicone-based and fluorine-based additives. Moreover, (8) By improving the adhesiveness between resin and a base material, the peelability between resin and a metal mold | die also improves. There are measures such as surface treatment of the substrate surface in advance, or addition of a polar molecule such as a monomer component having an N-vinyl group to the resin.

  From the above viewpoints, the cured resin 1 according to the present embodiment contains a cured product of polyethylene glycol di (meth) acrylate and urethane di (meth) acrylate. Thus, since the resin hardened | cured material 1 contains polyethyleneglycol di (meth) acrylate, while extending | stretching becomes favorable, since extensibility and elasticity are improved since urethane di (meth) acrylate is contained. As a result, the surface elastic modulus and surface hardness can be adjusted within a predetermined range, and in addition to softness and slipperiness, extensibility and resilience are imparted. A cured resin having an uneven structure can be realized. In other words, the present inventors have found that it is effective to have these characteristics in order to realize a cured resin product having excellent toughness and a good restoring force against elongation and having high scratch resistance. It has come to be solved.

  The blending guideline for the soft resin material is as outlined above, and specifically, it is more preferable to contain the following photopolymerizable mixture.

(Photopolymerizable mixture)
In the cured resin 1 according to the present embodiment, from the viewpoint of the above (1), a photopolymerizable composition prepared from a monomer, oligomer, or polymer having a photopolymerizable group is 80% by weight of the total composition. It is preferable to occupy the above, more preferably 90% by weight or more. The combination of the monomer, oligomer and polymer is not particularly limited. Moreover, you may contain the additive which does not have a photopolymerization group as functional provision to the resin cured material 1. FIG.

  Although it does not restrict | limit especially as a photopolymerization group, It is preferable that they are a (meth) acryloyl group, a vinyl group, and an allyl group. The (meth) acryloyl group means an acryloyl group or a methacryloyl group. In addition, (meth) acrylate in the text description means a monomer, oligomer or polymer containing a (meth) acryloyl group.

  From the viewpoint of the above (3), it is preferable that the main component is a bifunctional (meth) acrylate. From the viewpoint of the above (1) and (3), as the bifunctional (meth) acrylate, an EO-modified di (meth) acrylate Or PO-modified di (meth) acrylate. In particular, EO-modified di (meth) acrylate having a high molecular chain flexibility is more preferable because it is flexible and elastic and has an antistatic effect.

  For example, as bifunctional (meth) acrylate, KAYARAD NPGDA, FM400, R-167, HX-220, HX-620, R-604, R-684 manufactured by Nippon Kayaku Co., Ltd., SR212 manufactured by SARTOMER, SR213, SR238F, SR247, CD406, SR833, SR214, SR239, SR248, SR297, CD401, HDDA, IRR214-K, HPNDA manufactured by Daicel-Cytec, and light ester P-2M, 1.4BG manufactured by Kyoeisha Chemical Co., Ltd. , NP, 1.6HX, 1.9ND, 1.10DC, G-101P, G-201P, DCP-M, Light acrylate PTMGA-250, NP-A, MPD-A, 1.6HX-A, 1.9ND -A, MOD-A, DCP-A, BA-134, HPP- , G-201P, epoxy esters 80MFA, 3002M, 3002A, 300MK, and the like 3000A. Other examples include EO-modified di (meth) acrylate, PO-modified di (meth) acrylate, and urethane di (meth) acrylate as shown below.

  Specifically, as EO / PO modified di (meth) acrylate, bisphenol F-EO modified diacrylate, bisphenol A-EO modified acrylate, isocyanuric acid EO modified diacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, and the like The molecular structure preferably contains an ethylene glycol chain and / or a propylene glycol chain. For example, Toagosei Co., Ltd. M-208, M-211B, M-215, M-220, M-225, M-270, M-240, Nippon Kayaku Co., Ltd. KAYARAD PEG400DA, R-551, R SR712, SARTOMER, SR230, SR259, SR268, SR272, SR306H, SR344, SR349, SR508, CD560, CD561, CD562, CD564, C580, CD581, CD582, SR601, SR602, SR610, SSR9003, CD9038, CD9043 SR101, SR150, SR205, SR206, SR209, SR210, SR231, SR252, SR348, SR480, CD540, SR541, CD542, SR603, SR644, SR740, SR90 6, DPGDA, TPGDA, EBECRYL145, EBECRYL150, PEG400DA, EBECRYL11 manufactured by Daicel-Cytech, and light esters EG, 2EG, 4EG, 9EG, 14EG, BP-2EMK, BP-4EM, BP-6EM manufactured by Kyoeisha Chemical Co., Ltd. , Light acrylate 3EG-A, 4EG-A, 9EG-A, 14EG-A, BP-4EA, BP-4PA, BP-10EA, epoxy ester 40EM, 70PA, 200PA, and the like.

  Regarding the mixing composition ratio, the bifunctionality including EO-modified or PO-modified di (meth) acrylate with respect to the total mass of the photopolymerizable composition prepared from the monomer, oligomer, and polymer having a photopolymerizable group ( When the content of meth) acrylate is 60% by mass or more, compatibility with other bifunctional (meth) acrylates is improved, and when it is 65% by mass or more, the network density after curing is more uniform. become. In particular, in order to suppress water absorption while maintaining the flexibility of EO and PO, the content is particularly preferably 70% by mass or more. On the other hand, the upper limit is preferably 95% by mass or less in order to maintain flexibility, and more preferably 85% by mass or less in order to suppress a reduction in the antistatic effect.

  Moreover, the mixed composition containing EO modified | denatured and / or PO modified | denatured di (meth) acrylate and urethane di (meth) acrylate from the viewpoint of said (1)-(4) is more preferable, and EO modified | denatured di (meth) acrylate and urethane diene. A mixed composition containing (meth) acrylate is most preferred.

  Examples of urethane di (meth) acrylates include polyester, polyether, polycarbonate, and mixed systems. For example, UV-6630B, UV-3000B, UV-3200B, UV-3210EA, UV-3310B, UV-3500BA, UV-3520TL, UV-3700B, UV-6100B, UV-6640B, UV manufactured by Nippon Synthetic Chemical Industry Co., Ltd. -2000B, Toagosei Co., Ltd. M-1100, M-1200, M-1600, Nippon Kayaku Co., Ltd. UX-3204, UX-4101, UX-6000, UX-6000-M30, UX-6101, UX -7101, UX-8101, UX-0937, UXF-4001-M35, UXF-4002, bifunctional functional urethane acrylate oligomer (CN series), functional epoxy acrylate oligomer (CN series) manufactured by SARTOMER, Functional polyester acrylate Mer and the like (CN series), Daicel Cytec difunctional aromatic urethane acrylate, and aliphatic urethane acrylates. The average molecular weight (Mw) of each composition of urethane di (meth) acrylate is elastic at 3000 or more, more toughness at 5000 or more, and preferably rubbery at 10,000 or more, and elongation and resilience at 30000 or more. It is more preferable at the point which appears. On the other hand, since the tackiness increases as the molecular weight increases, Mw. More preferably, it is 70000 or less.

  Regarding the mixed composition ratio, it is preferable to contain 10 parts by mass to 500 parts by mass of urethane di (meth) acrylate with respect to 100 parts by mass of EO-modified or PO-modified di (meth) acrylate. By containing 10 parts by mass or more of urethane di (meth) acrylate, it is preferable in that the effects (1) to (4) described above can be sufficiently expressed by the physical properties after curing. By containing 20 parts by mass or more, the toughness and the antistatic effect are excellent, and by containing 40 parts by mass or more, the balance between extensibility and elasticity is improved and the restoring force is improved. On the other hand, when the upper limit is 500 parts by mass or less, water absorption can be suppressed, and when the upper limit is 400 parts by mass or less, tackiness can be suppressed. Furthermore, by making it 250 parts by mass or less, the balance between softness and slipperiness is improved. Moreover, by setting it as 200 mass parts or less, it becomes a viscosity suitable for continuous transfer productivity. In addition, when it contains EO modified | denatured and PO modified | denatured di (meth) acrylate simultaneously, or when multiple types of EO modified | denatured or PO modified | denatured di (meth) acrylate are contained, these total mass parts shall be 100 mass parts, this 100 masses It is preferable to prepare the mixture composition ratio with respect to parts, more preferably EO-modified or PO-modified di (meth) acrylate as a total mass part of 100 parts by mass, and more preferably with the mixture composition ratio. In particular, it is most preferable to prepare EO-modified di (meth) acrylate as 100 parts by mass. In particular, it is most preferable to use polyethylene glycol di (meth) acrylate as the EO-modified di (meth) acrylate in order to sufficiently exhibit the effects (1) to (4).

From the viewpoint of the above (8), in order to improve the adhesion with the substrate surface that is not particularly surface-treated,
A mixed composition containing EO-modified and / or PO-modified di (meth) acrylate and a monomer containing an N-vinyl group is more preferable, and includes an EO-modified di (meth) acrylate and a monomer containing an N-vinyl group. A mixed composition is most preferred.

  Examples of the monomer component having an N-vinyl group include N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone, and N-vinylcaprolamtam. One or more monomer components having an N-vinyl group may be used. In particular, N-vinylpyrrolidone is preferable because it has good compatibility with the resin composition, high reactivity, and good adhesion to various substrates.

  Regarding the mixed composition ratio, it is preferable that the monomer component having an N-vinyl group is contained in an amount of more than 0 parts by weight and 500 parts by weight or less with respect to 100 parts by weight of EO-modified or PO-modified di (meth) acrylate. In order to provide sufficient base material adhesion, it is preferable to contain 50 parts by mass or more of the monomer component having an N-vinyl group, and inclusion of 100 parts by mass or more is preferable because the adhesion becomes higher. By containing 150 parts by mass or more, the viscosity of the resin can be lowered, the wettability with the substrate is improved and the adhesion after curing is improved, and further by containing 200 parts by mass or more, Sufficient adhesion can be obtained even after curing in a short time after coating. On the other hand, by setting the upper limit value to 500 parts by mass or less, bleeding out from the molded product of unreacted monomers and low-polymerization degree oligomers can be minimized, and by setting it to 450 parts by mass or less, excessive moisture absorption of the molded product is achieved. Can be suppressed, and the moisture resistance of the molded body can be improved. In addition, when using the base material surface-treated beforehand by an easily bonding layer etc., it is not necessary to contain the monomer component which has N-vinyl group. In addition, when it contains EO modified | denatured and PO modified | denatured di (meth) acrylate simultaneously, or when multiple types of EO modified | denatured or PO modified | denatured di (meth) acrylate are contained, these total mass parts shall be 100 mass parts, and this 100 mass parts It is preferable to prepare at the mixed composition ratio with respect to the total composition part of either EO-modified or PO-modified di (meth) acrylate as 100 parts by mass, and more preferable to prepare at the mixed composition ratio. In particular, it is most preferable to prepare EO-modified di (meth) acrylate as 100 parts by mass. In particular, it is preferable to use polyethylene glycol di (meth) acrylate as the EO-modified di (meth) acrylate in order to sufficiently exhibit the effects (1) to (4) above, while an N-vinyl group is used. N-vinylpyrrolidone is preferable as a monomer component having a diol from the viewpoint of compatibility with polyethylene glycol di (meth) acrylate and good adhesion to a substrate.

  From the viewpoints of (5) and (7) above, it is preferable to add a small amount of a silicone-based additive or a fluorine-based additive. The additive here does not specifically limit the functional group of the terminal structure. That is, it may be an alcohol terminal, an alkane terminal, or the like, or a terminal structure containing a silane coupling or a terminal structure containing a (meth) acryl group. In particular, it is more preferable to add a small amount of silicone-containing (meth) acrylate or fluorine-containing (meth) acrylate that can be polymerized with other resin compositions, and it is more preferable to add a silicone-containing (meth) acrylate having good compatibility. The polymerizable functional group is not particularly limited, but bifunctional or monofunctional is preferable from the viewpoint of (3) above.

  Moreover, in the resin cured material 1 which concerns on this Embodiment, it is preferable that at least 1 type is included among a silicone type and a fluorine-type additive from the viewpoint of said (5) and (7). One type of silicone-based or fluorine-based additive added to the photopolymerizable mixture may be used alone, or two or more types may be used in combination. In particular, in the case of a resin composition containing EO-modified (meth) acrylate, a silicone-based additive is more preferable from the viewpoint of compatibility. Furthermore, in order to impart water repellency, a fluorine-based additive having low compatibility may be phase-separated and segregated to the surface. Further, it can be used in combination with other surface modifiers such as wear resistance, scratch resistance, fingerprint adhesion prevention, antifouling property, leveling property and water / oil repellency.

  Examples of the silicone-based additive include a silicone acrylate compound in which an acrylic group is bonded to a polydimethylsiloxane skeleton. For example, BYK-UV3500, BYK-UV3570 manufactured by Big Chemie Japan, EBECRYL350 manufactured by Daicel Cytec Co., Ltd., X-22-164, X-22-164AS, X-22-164A manufactured by Shin-Etsu Chemical Co., Ltd., X- 22-164B, X-22-164C, X-22-164E, X-22-174DX, X-22-2426, X-22-2475, and the like.

  As the fluorine-based additive, for example, “Factent” manufactured by Neos Co., Ltd. (for example, M series: Footgent 251, Footgent 215M, Footgent 250, FTX-245M, FTX-290M; S series: FTX-207S, FTX- 211S, FTX-220S, FTX-230S; F Series: FTX-209F, FTX-213F, Aftergent 222F, FTX-233F, Aftergent 245F; G Series: Aftergent 208G, FTX-218G, FTX-230G, FTS- 240G; Oligomer series: Aftergent 730FM, Aftergent 730LM; Aftergent P series; Aftergent 710FL, FTX-710HL, etc., DIC's "Megafuck" (for example, F-11) F-410, F-493, F-494, F-443, F-444, F-445, F-470, F-471, F-474, F-475, F-477, F-479, F -480SF, F-482, F-483, F-489, F-172D, F-178K, F-178RM, MCF-350SF, etc.), Daikin "OPTOOL (registered trademark)" (for example, DSX, DAC, AES), “Eftone (registered trademark)” (for example, AT-100), “Zeffle (registered trademark)” (for example, GH-701), “Unidyne (registered trademark)”, “Daifree (registered trademark)”, “Optoace (registered trademark)”, “Novec EGC-1720” manufactured by Sumitomo 3M Limited, “Fluorosurf (registered trademark)” manufactured by Fluoro Technology Co., Ltd., and the like.

  Concerning the mixed composition ratio, by containing 0.25 parts by mass or more of the silicone additive with respect to 100 parts by mass of EO-modified or PO-modified di (meth) acrylate, the releasability from the mold is improved, and 0 Containing 5 parts by mass or more improves the continuous transfer from the mold. Furthermore, the surface slip property of hardened | cured material becomes good by containing 1 mass part or more. On the other hand, the upper limit is preferably 4 parts by mass or less in order to maintain the adhesion to the substrate, and 3.5 parts by mass or less improves compatibility with the resin. By being 5 parts by mass or less, the surface segregation property is enhanced. In addition, when it contains EO modified | denatured and PO modified | denatured di (meth) acrylate simultaneously, or when multiple types of EO modified | denatured or PO modified | denatured di (meth) acrylate are contained, these total mass parts shall be 100 mass parts, and this 100 mass parts It is preferable to prepare at the above mixed composition ratio, more preferably at 100% by mass as the total mass part of either EO-modified or PO-modified di (meth) acrylate, particularly at the mixed composition ratio. It is most preferable to prepare EO-modified di (meth) acrylate as 100 parts by mass.

  The photopolymerization initiator causes a radical reaction or an ionic reaction by light. As the photopolymerization initiator, a photopolymerization initiator that causes a radical reaction is preferable. Specific examples thereof include the following photopolymerization initiators.

  From the viewpoint of the above (6), the photopolymerization initiator can sufficiently cure the resin by mixing 0.01% by weight or more with respect to the total mass of the photopolymerizable composition. If it exists, bleed-out to the resin surface of the unreacted initiator after hardening and the decomposition product can be reduced, and if it is 0.5 wt% to 5 wt%, the resin transmittance after curing is excellent.

  As acetophenone-based photopolymerization initiators, acetophenone, p-tert-butyltrichloroacetophenone, chloroacetophenone, 2,2-diethoxyacetophenone, hydroxyacetophenone, 2,2-dimethoxy-2′-phenylacetophenone, 2-aminoacetophenone And dialkylaminoacetophenone. Benzoin-based photopolymerization initiators include benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-2 -Methylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, benzyldimethyl ketal and the like.

  Benzophenone-based photopolymerization initiators include benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, methyl-o-benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, hydroxypropylbenzophenone, acrylic benzophenone, 4,4′-bis ( Dimethylamino) benzophenone, perfluorobenzophenone and the like. Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, diethylthioxanthone, and dimethylthioxanthone.

  Examples of the anthraquinone-based photopolymerization initiator include 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone and the like. Examples of ketal photopolymerization initiators include acetophenone dimethyl ketal and benzyl dimethyl ketal. Other photopolymerization initiators include α-acyl oxime ester, benzyl- (o-ethoxycarbonyl) -α-monooxime, acyl phosphine oxide, glyoxy ester, 3-ketocoumarin, 2-ethylanthraquinone, camphorquinone, tetra Examples thereof include methyl thiuram sulfide, azobisisobutyronitrile, benzoyl peroxide, dialkyl peroxide, tert-butyl peroxypivalate and the like. Examples of the photopolymerization initiator having a fluorine atom include perfluoro tert-butyl peroxide and perfluorobenzoyl peroxide. Moreover, these well-known and usual photoinitiators can be used individually or in combination of 2 or more types.

  The photopolymerizable mixture may contain a photosensitizer. Specific examples of the photosensitizer include n-butylamine, di-n-butylamine, tri-n-butylphosphine, allylthiourea, s-benzisothiuronium-p-toluenesulfinate, triethylamine, diethylaminoethyl methacrylate. , Triethylenetetramine, 4,4′-bis (dialkylamino) benzophenone, N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, tri It can be used in combination with one or more of known and commonly used photosensitizers such as amines such as ethanolamine.

  Examples of commercially available photopolymerization initiators include “IRGACURE” manufactured by Ciba (for example, IRGACURE 651, 184, 500, 2959, 127, 754, 907, 369, 379, 379EG, 819, 1800, 784, OXE01). , OXE02) and “DAROCUR” (for example, DAROCUR1173, MBF, TPO, 4265).

  In the cured resin 1 according to the present embodiment, ((reflectance after scratch test-reflectance before scratch test) / reflectivity before scratch test) × 100 in the entire visible range is 60% or less. Is preferable, and 40% or less is more preferable. In particular, at an arbitrary wavelength in the wavelength range of 500 to 600 nm with high visibility, the above formula is preferably 50% or less, more preferably 30% or less, and even more preferably 20% or less. . Thereby, the antireflection function before and after the scratch test of the resin composition 1 is sufficient. Here, the reflectance before and after the scratch test is, for example, the reflectance of the resin composition 1 before and after the touch pen scratch test with respect to the cured resin 1, as shown in Examples described later. As a specific example, when the reflectance at 550 nm before the scratch test of the resin composition 1 is 0.25% and the reflectance at 550 nm after the scratch test is 0.3%, the above range is satisfied.

(Method for producing cured resin)
The cured resin 1 according to the present embodiment is manufactured by forming a fine uneven structure on the surface of a soft resin material. As a method for molding the fine concavo-convex structure on the surface of the soft resin material, it is preferable to mold by a transfer method using a mold having the fine concavo-convex structure. The transfer method is not particularly limited, but a nanoimprint method is preferable in order to accurately transfer a concavo-convex structure having a size of several tens of nm to 1000 nm. Depending on the curing conditions of the resin material, thermal nanoimprint method, optical nanoimprint method, room temperature nanoimprint method and casting method can be mentioned, but from the viewpoint of rapid transfer and continuous production in roll-to-roll, optical nanoimprint method Is particularly preferred.

(Mold)
As the mold, a mold having a concavo-convex structure inverted from the concavo-convex structure molded into the resin material is used. Examples of the mold material include quartz glass, ultraviolet light transmitting glass, sapphire, diamond, polydimethylsiloxane, and other silicone materials, fluororesin, silicon, SiC, mica, and the like.

  When the cured resin material is peeled from the mold, it is preferable to release the mold surface in advance in order to improve the mold release property between the resin material and the mold. As the release treatment agent, a silane coupling release agent is preferable, and a fluorine-containing release agent is more preferable. Examples of commercially available release agents include Daikin Industries, Ltd. OPTOOL DSX, Durasurf HD1101 and HD2101, and Sumitomo 3M Novec.

  Next, an example of a method for producing a cured resin according to the present embodiment will be described in detail. In the method for producing a cured resin according to the present embodiment, a soft resin material is applied on a base material (application process), and the base material coated with the resin material is formed into a fine uneven structure of a mold. The resin material is cured by exposing the resin material to the fine uneven structure of the mold (exposure process), and the cured resin material is peeled from the mold to cure the resin 1 Is manufactured (peeling step).

  In the coating step, a soft material is coated on the substrate to form a film. As a method of applying the resin composition on the substrate, the casting method, potting method, spin coating method, roller coating method, bar coating method, casting method, dip coating method, die coating method, Langmuir projet method, spray coating Method, air knife coating method, flow coating method, curtain coating method and the like.

  When the base material area is larger than the mold area, the resin composition may be applied to the entire surface of the base material, or the resin composition is applied only to a range where the resin composition is applied to a part of the substrate and embossed. It may be present.

  By pre-baking after applying the resin composition to the substrate, the solvent can be distilled off when the solvent is contained, and void formation derived from the residual solvent after curing can be reduced. As other effects, surface migration of internally added additives (for example, fluorine-containing polymerizable (meth) acrylate and silicone-containing (meth) acrylate) can be promoted, and the cured resin surface has good slipperiness. Become. As a result, it is possible to obtain a high-quality resin cured product with low defects by improving the scratch resistance of the surface of the cured resin product or improving the releasability from the mold. The prebaking temperature is preferably 25 ° C to 120 ° C, more preferably 40 ° C to 100 ° C, further preferably 50 ° C to 100 ° C, and most preferably 60 ° C to 100 ° C. The prebaking time is preferably 30 seconds to 30 minutes, more preferably 1 minute to 15 minutes, and further preferably 3 minutes to 10 minutes.

  It is preferable to perform the process which improves the adhesiveness of a base material and a resin composition. For example, on the surface to be bonded, chemical bonding with the resin composition, easy adhesion coating for physical bonding such as penetration, primer treatment, corona treatment, plasma treatment, UV / ozone treatment, high energy ray irradiation treatment It is preferable to perform surface roughening treatment, porosification treatment, and the like.

  In the pressing step, it is preferable that a highly flexible base material is gently coated on the fine concavo-convex structure of the mold so as to prevent bubbles from entering and pressed under a constant pressure. The press pressure at the time of pressing is preferably more than 0 MPa to 10 MPa, more preferably 0.01 MPa to 5 MPa, and further preferably 0.01 MPa to 1 MPa.

  In the exposure step, it is preferable to expose from the substrate side when the light transmittance of the mold is low. On the other hand, when the mold has a high transmittance for light of an ultraviolet wavelength, for example, when the mold material is synthetic quartz, it is preferable to expose from at least one side of the substrate side or the mold side. It is more preferable to expose from both sides on the mold side. You may make it harden | cure by apply | coating only a curable resin composition to a master mold, without using a base material. In that case, in order to prevent polymerization inhibition by oxygen, a method of exposing in a nitrogen atmosphere or an argon atmosphere, or a method of covering with a base material with low adhesiveness, and peeling off the base material and the cured resin after curing. A cured product can be produced by, for example.

As an exposure light source to be used, a metal halide lamp, a high-pressure mercury lamp, a chemical lamp, or a UV-LED is preferable. From the viewpoint of suppressing heat generation during long-time exposure, it is preferable to use a filter (including a band-pass filter) that cuts a wavelength longer than the visible wavelength. As integrated light quantity is preferably 300 mJ / cm ² or more at a wavelength of 365 nm, for the purpose of obtaining a high reaction rate cured products, preferably at least 800 mJ / cm @ ^2, more preferably ^{800mJ / cm 2 ~6000mJ / cm 2} , a resin with light In order to prevent deterioration, 800 mJ / cm ^{2 to} 3000 mJ / cm ² is particularly preferable.

  In the peeling step, the soft resin material photocured by exposure is peeled from the mold. In the peeling process, as described above, when the mold surface is subjected to the mold release treatment, the cured resin material can be easily peeled from the mold surface. The cured resin 1 is manufactured through the above steps.

(Optical element)
Next, the optical element according to the present embodiment will be described. FIG. 4 is a schematic cross-sectional view showing an example of the optical element 2 according to the present embodiment. As shown in FIG. 4, the optical element 2 according to the present embodiment includes a base material 13 and a cured resin layer 100 that is provided on the base material 13 and contains the cured resin product 1 described above.

  FIG. 5 is a schematic cross-sectional view showing another example of the optical element according to the present embodiment. As shown in FIG. 5, the optical element 3 according to the present embodiment includes a cured resin layer 101 (first cured resin layer) provided on at least one main surface of the substrate 13, and this resin. And a cured resin layer 100 (second cured resin layer) provided on the cured product layer 101. The cured resin layers 100 and 101 contain the cured resin 1 described above. From the viewpoint of scratch resistance, the outermost layer of the optical element 3 is preferably composed of a soft and tough flexible resin cured product layer 100 (the same configuration as the resin cured product 1 described above). For the cured resin layer 101 other than the outermost layer, the material of the resin is not particularly limited. In addition, as the optical element 3, as long as it has one or more resin cured material layers containing the resin cured material 1 mentioned above, the several resin cured material layer may be laminated | stacked. Further, in addition to the cured resin layers 100 and 101, coating treatment or surface treatment of over 0 nm to about 100 nm is performed to provide functionality such as slipperiness, tackiness, and antireflection effect to the interface between layers and the layer surface. May be applied.

  As the base material 13, the adhesiveness with the resin cured material layer 100 which has the convex part 11 and the recessed part 12 is good, a refractive index difference is small with the resin cured material layer 100, and between the resin cured material layers 100, It is desirable to use one having a small haze. Examples of the material satisfying these include glass and resin. The substrate 13 preferably has flexibility, easy processability, high productivity, and high impact, is lightweight, and is inexpensive. Resin is mentioned as a material which satisfy | fills these. In addition, as the base material 13, it is not limited to these, According to a use purpose and a use, organic materials, such as inorganic materials, such as glass, a ceramic, a metal, and resin can be selected arbitrarily.

  In the optical elements 2 and 3 according to the present embodiment, there are a case where transparency is required and a case where transparency is required. For this reason, it is desirable to select the kind of the base material 13 according to a use purpose or a use. When transparency is required, the base material 13 needs to be substantially transparent in the wavelength region to be used. In this case, it is preferable to use a transparent resin or glass as the substrate 13. Further, when flexibility is required, it is preferable to use a transparent resin. Moreover, when non-transparency is required, the base material 13 needs to be opaque in the wavelength region to be used. In this case, it is preferable to use ceramic, metal, or opaque resin as the base material 13. Furthermore, when flexibility, flexibility, easy processability, high productivity, and high impact resistance are required, it is preferable to use an opaque resin because it is lightweight and inexpensive.

  Examples of the transparent resin include polymethyl methacrylate resin (PMMA resin), acrylic resin, polycarbonate resin (PC resin), polystyrene resin (PS resin), methyl methacrylate-styrene resin (MS resin), and styrene resin. , Cycloolefin resin (COP resin), polyarylate resin, polyetherimide resin, polyether sulfone resin, polysulfone resin, polyether ketone resin, polyethylene terephthalate resin (PET resin), polyethylene naphthalate resin (PEN resin), Examples include polytrimethylene terephthalate resin, aromatic polyester resin, triacetyl cellulose resin (TAC resin), polyimide resin, acrylic resin, epoxy resin, urethane resin such as ultraviolet curable resin, and thermosetting resin.In particular, PMMA resin, acrylic resin, PC resin, PS resin, styrene resin, COP resin, PET resin, PEN resin, aromatic polyester resin, and TAC resin are preferable.

  Examples of the opaque resin include ABS resin, AAS resin, AES resin, ACS resin, rubber-containing styrene resin, rubber-containing acrylic resin, polyamide resin, polyacetal resin, polyethylene resin, cross-linked polyethylene resin, polypropylene resin, and polychlorinated resin. Examples thereof include vinyl resins, polyphenylene ether resins, modified polyphenylene ether resins, and polybutylene terephthalate resins. Also, ABS resin (or AAS resin, AES resin, ACS resin, rubber-containing styrene resin) / polyamide resin, ABS resin (or AAS resin, AES resin, ACS resin, rubber-containing styrene resin) / acrylic resin And the like.

  When the substrate 13 is a resin, an additive may be added as necessary within a range in which the effect as the optical elements 2 and 3 is obtained. The additive may be directly contained in the resin or may be layered on the surface of the resin substrate. Examples of the additive include organic and / or inorganic particles, plasticizers, antioxidants, ultraviolet absorbers, antistatic agents, antifogging agents, and easy adhesives.

  In order to improve the impermeability of the optical elements 2 and 3, a black pigment and / or dye may be contained in the resin of the base material 13. Further, a black paint may be applied to the surface where the uneven structure is not formed.

  Further, a barrier resin layer may be formed on the surface of the base material 13 by coating or the like as long as the effects as the optical elements 2 and 3 are obtained. By forming the barrier resin layer on the surface of the base material 13, the base material 13 can be protected from deterioration factors such as heat, light, moisture, oxygen, carbon dioxide, nitrogen, and hydrogen.

  When the base material 13 is glass, a surface treatment such as a silane coupling agent, primer treatment, or UV treatment can be applied. Moreover, you may use combining these surface treatments. Moreover, you may use the base material 13 in which the surface coating, the contact bonding layer, and the interference reduction layer are formed as the base material 13. FIG.

  As the shape of the base material 13, a plate, a sheet, a film, a thin film, a woven fabric, a nonwoven fabric, other arbitrary shapes, and a composite of these can be selected according to the purpose of use. When flexibility is required, it is preferable to use a sheet, a film, a thin film, a woven fabric, or a non-woven fabric.

  The thickness of the base material 13 can be selected according to the intended purpose. When thinning or flexibility is required, the thickness of the substrate 13 is preferably 350 μm or less, more preferably 190 μm or less, further preferably 100 μm or less, and most preferably 85 μm or less. Further, the thickness of the substrate is preferably 10 μm or more from the viewpoint of easy handling.

  Each cured resin layer 100, 101 has a thickness of preferably 200 nm or more, more preferably 1 μm or more, from the viewpoint of scratch resistance. Further, when a touch pen or the like is used as an injured body, the thickness of the cured resin layers 100 and 101 is more preferably 3 μm or more, and particularly preferably 5 μm or more, from the assumed depth of damage. Furthermore, when assuming use in an environment where external stress is repeatedly applied, it is most preferable that the cured resin layers 100 and 101 have a thickness of 10 μm or more. Considering the warpage of the base material 13 due to the curing shrinkage of the resin, the cured resin layers 100 and 101 preferably have a thickness of 100 μm or less, and when applied as a transparent member, the thickness is 80 μm or less. It is more preferable. Further, from the viewpoint of productivity, the cured resin layers 100 and 101 are preferably 50 μm or less in thickness, and more preferably 20 μm or less in terms of cost.

  The number of the cured resin layers 100 and 101 in the optical element 3 is preferably the optical element 3 having one or more cured resin layers 100 and 101 from the viewpoint of resistance to indentation scratches and an antireflection effect. From the viewpoint of productivity that can be manufactured by a simple process, one or two layers are more preferable. Furthermore, since an optical member with good reproducibility can be produced by reducing the number of laminated interfaces, the cured resin layers 100 and 101 are composed of one layer having the smallest number of interfaces, that is, the base material 13 and one cured resin layer. Most preferably, it consists of 100.

  At the interface between the base material 13 and the cured resin layer 100 of the optical element 3 and at the interface between the cured resin layer 100 and the cured resin layer 101, the refractive index difference is 0.2 from the viewpoint of reducing each reflection. Hereinafter, it is preferably 0.001 or more, more preferably 0.1 or less and 0.001 or more, and most preferably 0.05 or less and 0.001 or more. In addition, the refractive index of the functional thin film (for example, a thin film layer for the purpose of interlayer adhesion or surface slipperiness) applied to the interface or the surface of the optical element 3 is not particularly limited.

(optical properties)
In the optical elements 2 and 3 according to the present embodiment, the regular reflectance is preferably 2% or less from the ultraviolet wavelength to the near infrared wavelength region, and the regular reflectance is preferably 380 nm to 800 nm in the wavelength region. More preferably, it is 1.5% or less. Further, in the wavelength region of 450 nm to 700 nm in the vicinity of 550 nm where the visibility is high, the regular reflectance is more preferably 1% or less, and particularly preferably 0.5% or less. In addition, the said regular reflectance means the regular reflectance with respect to the light which injected at 5 degree | times from the direction perpendicular | vertical to the surface of the resin cured material layer 100 (resin cured material 1).

  In the optical elements 2 and 3 according to the present embodiment, the diffuse reflectance is preferably 2% or less in the ultraviolet to near infrared wavelength region, and the diffuse reflection is preferably performed in the wavelength region of 380 nm to 800 nm. The rate is more preferably 1.5%, and the diffuse reflectance is more preferably 1% or less in the wavelength region of 450 nm to 700 nm in the vicinity of 550 nm where the visibility is high. In addition, the said diffuse reflectance means the diffuse reflectance with respect to the light which injected at 7 degree | times from the direction perpendicular | vertical to the surface of the resin cured material layer 100 (resin cured material 1).

  As described above, according to the cured resin 1 according to the present embodiment, it is soft, has slipperiness, and has a restoring force with respect to elongation. Good scratch resistance against scratching by fibers, touch pens, etc. Further, since the cured resin 1 is soft, it is easy to disperse the load inside the cured resin 1 with respect to the pressing force when scratching with a touch pen or the like, and the surface friction is provided by providing slipperiness. The resistance is reduced, and the stress load on the cured resin 1 can be reduced. Furthermore, there exists elongation and it becomes possible to also suppress the fracture | rupture of the resin cured material 1 because a restoring force becomes favorable. Therefore, by combining them, it is possible to realize a cured resin that exhibits scratch resistance even under a larger load.

  Further, in the cured resin 1 according to the above-described embodiment, the resin cured product 1 exhibits excellent scratch resistance against a scratched body such as a touch pen, and the resin cured product 1 itself exhibits a low surface resistance value. A certain resin molding can be obtained. Further, it is possible to realize the optical element 2 having excellent optical characteristics and excellent antireflection function in a wide wavelength range from visible to near infrared and a wide incident light angle range.

  Hereinafter, the present invention will be described in detail with reference to specific examples and comparative examples, but the present invention is not limited to the following examples.

[Preparation of Resin A to Resin N]
The composition of resin A to resin N is shown in Table 1 below. Relevance of each item was set as “◯”, and non-applicable was set as “X”. About preparation of each resin, it is as follows.

(Preparation of resin A)
In a brown container, urethane diacrylate (UV3000B, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 150 g, polyethylene glycol diacrylate (KAYARAD PEG400DA, manufactured by Nippon Kayaku Co., Ltd.) 150 g, 1,9-nonanediol diacrylate (light acrylate 1.9ND-A) 150 g, N-vinylpyrrolidone 23.2 g, and silicon diacrylate (EBECRYL350, manufactured by Daicel-Cytec) 800 mg are added in this order, and the mixture is warmed in a 50 ° C. hot water bath for about 15 minutes. The viscosity of the resin was lowered. With the resin viscosity lowered, the resin was mixed vigorously with a spatula until uniform. After cooling to room temperature, 9.1 g of a photopolymerization initiator (DAROCUR TPO, Ciba) was added, and the photopolymerization initiator was dissolved with an ultrasonic device for about 2 hours. This was designated as Resin A.

(Preparation of resin B)
155 g of urethane diacrylate (UV3000B, manufactured by Nippon Synthetic Chemical Industry), 155 g of polyethylene glycol diacrylate (KAYARAD PEG400DA, manufactured by Nippon Kayaku Co., Ltd.), 1,9-nonanediol diacrylate (light acrylate 1.9ND-A) 155 g, N-vinylpyrrolidone 99 g, and silicon diacrylate (EBECRYL350, manufactured by Daicel-Cytec) 828 mg were added in this order, and the resulting mixture was warmed in a hot water bath at 50 ° C. for about 15 minutes. The viscosity of was lowered. With the resin viscosity lowered, the resin was mixed vigorously with a spatula until uniform. After cooling to room temperature, 9.4 g of a photopolymerization initiator (DAROCUR TPO, Ciba) was added, and the photopolymerization initiator was dissolved with an ultrasonic device for about 2 hours. This was designated as Resin B.

(Preparation of resin C)
155 g of urethane diacrylate (UV3000B, manufactured by Nippon Synthetic Chemical Industry), 155 g of polyethylene glycol diacrylate (KAYARAD PEG400DA, manufactured by Nippon Kayaku Co., Ltd.), 1,9-nonanediol diacrylate (light acrylate 1.9ND-A) (Manufactured by Kyoeisha Chemical Co., Ltd.) 155 g and 99 g of N-vinylpyrrolidone were added in this order, and the mixture was warmed in a hot water bath at 50 ° C. for about 15 minutes to reduce the viscosity of the resin. With the resin viscosity lowered, the resin was mixed vigorously with a spatula until uniform. After cooling to room temperature, 9.4 g of a photopolymerization initiator (DAROCUR TPO, Ciba) was added, and the initiator was dissolved with an ultrasonic device for about 2 hours. This was designated as Resin C.

(Preparation of resin D)
In a brown container, 165 g of trimethylolpropane triacrylate (Aronix (registered trademark) M309 (manufactured by Toagosei Co., Ltd.), 165 g of 1,9-nonanediol diacrylate (light acrylate 1.9ND-A, manufactured by Kyoeisha Chemical Co., Ltd.), N-vinyl Add 165 g of pyrrolidone, 2.5 g of silicon diacrylate (EBECRYL350, manufactured by Daicel-Cytec) and 10 g of photopolymerization initiator (DAROCUR TPO, Ciba) in this order, and uniformly with an ultrasonic device under light shielding for about 2 hours. This was dissolved as Resin D.

(Preparation of resin E)
150 g of a mixture containing a urethane acrylate oligomer in a brown container (Beamset 575CB, Arakawa Chemical Industries Co., Ltd.), 30 g of N-vinylpyrrolidone, 16 g of silicon diacrylate (EBECRYL350, manufactured by Daicel Cytec Co., Ltd.) are added in this order. The viscosity of the resin was lowered by warming in a hot water bath for about 15 minutes. With the resin viscosity lowered, the resin was stirred vigorously with a spatula and mixed until uniform. After cooling to room temperature, 4 g of a photopolymerization initiator (DAROCUR TPO, Ciba) was added, and the initiator was dissolved with an ultrasonic device for about 2 hours. This was designated as Resin E.

(Preparation of resin F)
A mixture containing urethane acrylate oligomer in a brown container (Beamset 575CB, Arakawa Chemical Industries) 140g, N-vinylpyrrolidone 40g, silicon diacrylate (EBECRYL350, Daicel Cytec) 16g was added in this order, and 50 ° C. The viscosity of the resin was lowered by warming in a hot water bath for about 15 minutes. With the resin viscosity lowered, the resin was stirred vigorously with a spatula and mixed until uniform. After cooling to room temperature, 4 g of a photopolymerization initiator (DAROCUR TPO, Ciba) was added, and the initiator was dissolved with an ultrasonic device for about 2 hours. This was designated as Resin F.

(Preparation of resin G)
In a brown container, 67 g of polyester acrylate oligomer (CN2271E, manufactured by Sartomer), 16.75 g of epoxy monoacrylate (CN152, manufactured by Sartomer), 3.35 g of photopolymerization initiator (DAROCUR1173, manufactured by Ciba Specialty Chemicals), In this order, the mixture was stirred with a stirrer at room temperature for 1 hour. This was designated as Resin G.

(Preparation of resin H)
In a brown container, 67 g of polyester acrylate oligomer (CN2271E, manufactured by Sartomer), 16.75 g of epoxy monoacrylate (CN152, manufactured by Sartomer), 130 mg of silicon diacrylate (EBECRYL350, manufactured by Daicel-Cytec), photopolymerization initiator (DAROCUR1173, 3.35 g of Ciba Specialty Chemicals) was added in this order, and the mixture was stirred with a stirrer at room temperature for 1 hour. This was designated as Resin H.

(Preparation of resin I)
In a brown container, 67 g of polyester acrylate oligomer (CN2271E, manufactured by Sartomer), 16.75 g of epoxy monoacrylate (CN152, manufactured by Sartomer), 871 mg of silicon diacrylate (EBECRYL350, manufactured by Daicel-Cytec), photopolymerization initiator (DAROCUR1173, 3.35 g of Ciba Specialty Chemicals) was added in this order, and the mixture was stirred with a stirrer at room temperature for 1 hour. This was designated as Resin I.

(Preparation of resin J)
In a brown container, 67 g of polyester acrylate oligomer (CN2271E, manufactured by Sartomer), 16.75 g of epoxy monoacrylate (CN152, manufactured by Sartomer), 8.71 g of silicon diacrylate (EBECRYL350, manufactured by Daicel-Cytec), photopolymerization initiator ( DAROCUR 1173 (manufactured by Ciba Specialty Chemicals) was added in this order, and the mixture was stirred with a stirrer at room temperature for 1 hour. This was designated as Resin J.

(Preparation of resin K)
21.84 g of polyester acrylate oligomer (CN2271E, manufactured by Sartomer), 50.97 g of tripropylene glycol diacrylate (Biscoat 310HP, manufactured by Osaka Organic Chemical Industry), photopolymerization initiator (DAROCUR 1173, Ciba Specialty Chemicals) 2.91 g) were added in this order, and the mixture was stirred with a stirrer at room temperature for 1 hour. This was designated as Resin K.

(Preparation of resin L)
In a brown container, 21.84 g of polyester acrylate oligomer (CN2271E, manufactured by Sartomer), 50.97 g of tripropylene glycol diacrylate (Biscoat 310HP, manufactured by Osaka Organic Chemical Industry Co., Ltd.), 114 mg of silicon diacrylate (EBECRYL350, manufactured by Daicel Cytec) , 2.91 g of a photopolymerization initiator (DAROCUR 1173, manufactured by Ciba Specialty Chemicals) was added in this order, and the mixture was stirred with a stirrer at room temperature for 1 hour. This was designated as Resin L.

(Preparation of resin M)
In a brown container, polyester acrylate oligomer (CN2271E, manufactured by Sartomer) 21.84 g, tripropylene glycol diacrylate (Biscoat 310HP, manufactured by Osaka Organic Chemical Industry) 50.97 g, silicon diacrylate (EBECRYL350, manufactured by Daicel Cytec) 757 mg , 2.91 g of DAROCUR 1173 (manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator was added in this order, and the mixture was stirred with a stirrer at room temperature for 1 hour. This was designated as Resin M.

(Preparation of resin N)
Polyester acrylate oligomer (CN2271E, manufactured by Sartomer) 21.84g, tripropylene glycol diacrylate (Biscoat 310HP, manufactured by Osaka Organic Chemical Industry) 50.97g, silicon diacrylate (EBECRYL350, manufactured by Daicel Cytec) 7 .57 g and 2.91 g of a photopolymerization initiator (DAROCUR 1173, manufactured by Ciba Specialty Chemicals) were added in this order, and the mixture was stirred with a stirrer at room temperature for 1 hour. This was designated as Resin N.

(Mold)
A moth-eye concavo-convex original plate was prepared by laser interference exposure, and then a nickel-plated Ni mold was obtained by electroforming using the prepared original plate. Details are as follows.

(Original plate production method)
A glass plate on which a positive photoresist layer having a uniform thickness was formed was irradiated with two parallel laser beams by a laser interference exposure method to obtain an interference draft. Next, the glass plate was rotated 60 ° to obtain an interference paper in the same manner. Further, the glass plate was rotated 60 ° to obtain an interference paper in the same manner. Thereafter, the photoresist was developed, and the portion around the interference paper was dissolved to prepare an original having a moth-eye-like continuous structure composed of concave and convex portions. The arrangement of the concave and convex portions was a hexagonal lattice pattern.

(Production of Ni mold)
A Ni mold having a moth-eye concavo-convex structure (flat plate shape, thickness 0.2 mm) was produced from the produced original plate by nickel electroforming. In the Ni mold, the pitch of the concavo-convex structure was 240 nm and the height was 310 nm, and the concave and convex portions were each arranged in a hexagonal lattice pattern. The Ni mold surface was subjected to mold release treatment using a commercially available mold release agent (Daikin Industries, Durasurf HD-2101Z).

(Production of transfer film)
Resin A is applied to a 80 μm-thick triacetyl cellulose resin (hereinafter abbreviated as TAC) film (manufactured by FUJIFILM, TD80UL-H), and the mold (Ni mold) and TAC film are applied with the coated surface facing down. It was covered so that there was no air in between. Ultraviolet rays were irradiated from the TAC film side using a metal halide lamp at 1500 mJ / cm ² to transfer the uneven shape of the mold. The TAC film was peeled from the mold to obtain a transfer film having a moth-eye concavo-convex structure having a length of 200 mm and a width of 150 mm.

  Similarly, a transfer film was produced with a combination of a base material (TAC, PET film) and a resin (resin A to resin N) described in Table 2. In addition, about the PET film, the PET film (Toyobo Co., Ltd. Cosmo Shine A4100) which has an easily bonding layer was used, and the easily bonding surface was made into the resin application surface. In addition, it measured using the thickness gauge (Mitutoyo Co., Ltd./Code No. 547-401), and each transfer film consisting of a base material and a resin cured material layer was designated as “Sample 1 to Sample 16” (see Table 2 below). .

  About the adhesiveness (base-material adhesiveness) between a resin cured material layer and a base material, it evaluated in the crosscut test of the transfer film. According to JISK5600-5-6, the transfer film was cut into a grid pattern (25 cm), and when the grid was peeled off with a tape having a prescribed adhesive strength, the adhesion was determined by how many peeled from the substrate. The detailed conditions are as follows. Cross-cut method (JIS K5600-5-6); line width: 2 mm, number of squares: 5 × 5, adhesive tape: Nichiban CT-18 (adhesive strength: 10 ± 1 N / 25 mm), peel angle: 60 degrees. The case where the “tape peeled square / total square” is “0/25” is “◯”, and the case where the “tape peeled square / total square” is “1 / 25-24 / 25” is “△”. The case where “tape peeled square / total square” was “25/25” was defined as “x”.

  In the case of a transfer film produced from a substrate having an easy-adhesion layer (samples 3 to 16), the grids peeled off by tape peeling were zero, and sufficient adhesion could be confirmed. On the other hand, in sample 1 and sample 2 using a base material that does not have an easy-adhesion layer such as a TAC film, only sample 1 cured with resin A was partially tape-peeled. Since the final concentration of NVP was high in resin B, it was found that the final concentration of NVP contributed to the adhesion with the substrate.

(Surface physical properties of transfer film)
The surface elastic modulus and surface hardness of each transfer film were measured using a nanoindenter apparatus (Nano IndenterXP / software: TestWorks 4 manufactured by Toyo Technica Co., Ltd.). Detailed condition settings are as follows. Allowable Drift Rate: 0.5 [nm / s], Load Rate Multiple For Unload Rate: 1, Maximum Load: 0.3 to 1 [gf], Number of Times to Load: 1, Peak Hold Time: 10 [ Percent To Unload: 90 [%], Time To Load: 15 [s]. In addition, about Maximum Load, the suitable load load was selected so that the measurement depth might be set to about 2 micrometers-3 micrometers. After measurement, the measurement start depth was corrected to zero on the software, and the surface elastic modulus and surface hardness averaged over 10 measurements were obtained (see Table 3 below).

  The transfer films (samples 1 to 5) made of the resins A, B, and C have a surface elastic modulus of about 0.2 to 0.5 [GPa] and a surface hardness of 0.02 regardless of the material of the substrate. Before and after [GPa], it was found that the resin was soft. Since all of the resins are mainly composed of a bifunctional acrylate having an ethylene glycol structure or a urethane structure, it is assumed that the resin contributes to the softness of the resin. Moreover, since the transfer films (sample 10 and sample 14) produced with the resin H and the resin L are similarly composed of bifunctional acrylate as a main component, they exhibited softness. On the other hand, in the transfer films (sample 6 to sample 8) obtained using Resin D, Resin E, and Resin F mainly composed of a polyfunctional acrylate having three or more functions, the surface elastic modulus is about 2 to 3 [GPa]. The surface hardness was about 0.3 [GPa], about 10 times as hard as that of the soft resin.

(Slip evaluation)
About the surface slipperiness of each sample film, the dynamic friction force was measured by the measuring method according to JISK7125. The measurement results are summarized in Table 4.

  As can be seen from Table 4, it does not depend on the type of resin composition, and when it contains a small amount of silicone acrylate, the slipping property is improved, and even with a content of about 0.15% by weight relative to the total mass of the photopolymerizable composition. It turns out that there is enough effect.

(Abrasion resistance evaluation)
First, a black vinyl tape (38 mm width, black, product number No. 200-38-21) is pasted on the back side of each film (opposite side of the concavo-convex molding surface) to prevent reflection on the back side before and after the test. This makes it easier to observe the state of fracture of the surface. Next, the uneven surface of each sample film was strongly wiped with bemcot with ethanol, and the degree of surface destruction of the resin was observed. It has been confirmed that there is no deterioration of the resin by ethanol.

  For example, if a fluorescent lamp is projected from a surface with an uneven pattern and the reflected light is observed, if the low reflectivity or color of the surface does not change before and after wiping, it is judged as `` ◎ '', and the surface reflection before and after wiping If the texture and color change slightly, it will be judged as `` ○ '', and after wiping it will be judged as `` X '' if there is a clear glare on the surface, and if the resin cured product on the surface will be scraped off after wiping, `` XX (See FIG. 6). The evaluation results are shown in Table 5 below.

  In addition, when the surface of the sample film after each wiping was observed with a scanning electron microscope, the concavo-convex pattern damage was not confirmed with “◎”, and the part with the concavo-convex pattern inclined was confirmed with “◯”. . On the other hand, in “×”, the concavo-convex pattern is completely crushed, and in “XX”, the entire cured resin including the concavo-convex pattern is shaved, and the resin is destroyed so that the substrate can be seen inside. Was confirmed.

  As another test method, a steel wool test was performed. The evaluation conditions are as follows. Apparatus: Surface property tester (manufactured by Imoto Seisakusho Co., Ltd.), Steel wool: Nippon Steel Wool Co., Ltd. BON STAR (registered trademark) No. 0000, load: 100 g, speed: 50 scale, number of times: 5 reciprocations. As with the wiping test, the back surface of each sample was made easy to observe the damaged state of the surface by applying black tape. Regarding the judgment of how to scratch after the test, if there is a partial scratch in the part where the steel wool has passed and the reflection is small, it is “○”, and there are innumerable scratches in the part where the steel wool has passed and the reflection is large. “×” is assigned to the case of “”, and “△” is assigned to the case where “○” and “x” are intermediate. An example of “◯” and “x” determination is shown in FIG. As shown in FIG. 7, in the case of “◯” determination, it is understood that a slight flaw is generated at a portion through which the steel wool has passed, but the reflection of light is small. Further, in the case of “x” determination, it can be seen that a large number of scratches are generated on the line at the portion where the steel wool has passed, and the reflection of light is large. The results of evaluation based on the above evaluation methods are summarized in Table 5 below.

  As can be seen from Table 5, in Samples 6 to 8 made of a hard resin, the reflectance was significantly increased after wiping off the ethanol, and the destruction of the obvious uneven pattern was confirmed. On the other hand, in the soft samples 1 to 4, no surface damage was observed. In the sample 5 using the resin C, which is a resin not containing a silicone additive, a low reflectance was maintained although a portion where the color was slightly deformed was confirmed. However, even in the case of a soft resin, the samples 9 to 16 were scraped. Resin A to Resin C used in Samples 1 to 5 have extensibility with polyethylene glycol diacrylate and elasticity and flexibility of urethane diacrylate. Therefore, it is considered that the resin surface layer having elongation and high restoration property is prepared by blending these as main components. These results showed the same tendency in the steel wool test.

(Abrasion resistance evaluation using a touch pen)
The uneven surface of the transfer film was repeatedly rubbed with a touch pen to evaluate the degree of scratching. First, a touch pen (manufactured by Lynx Products, extra touch pen Lite for DSLite) was fixed to a surface property tester (manufactured by Imoto Seisakusho), and a load of 100 g was placed on the fixing jig. Next, the fixed height of the touch pen was readjusted so that the pen tip of the touch pen was in perpendicular contact with the sample (transfer film) while looking at the horizontal level on the device arm. The transfer film was fixed to the sample stage with the concave / convex pattern forming surface facing upward (touch pen side). Scratching at an outward path length of about 30 mm was repeated 10 times or 25 times. The scratching speed was set to “50” or “100” on the apparatus speed scale.

  After the scratch test, the back side of the transfer film (the back side of the base material on which the concavo-convex structure is not formed) is not filled with black vinyl tape (manufactured by Yamato, 38 mm width, black, product number No. 200-38-21). Thus, the back surface reflection was prevented and the degree of scratches on the surface was visually evaluated. Next, the scratch test mark was observed in detail using a scanning electron microscope. There were cases where there was no scratch on the transfer film and some thin scratches were observed by observation with a scanning electron microscope. “◎”. Specific determination criteria are shown in FIG. The scratches of each transfer film were evaluated based on this criterion, and the determination results are summarized in Table 6.

  Samples 6 to 8 made of hard resin all had clear scratches that could be confirmed by visual observation. When observed with a scanning electron microscope, it was confirmed that the concavo-convex structure was completely crushed in most places. On the other hand, it was found that Samples 1 to 5 and Samples 9 to 16 made of a soft resin are not damaged or difficult to be attached. However, when the scratching speed was increased, thin scratches were confirmed in Sample 5, Sample 9, and Sample 13. For example, since the resin C does not contain the EBECRYL350 component which is a silicone-based additive, it was considered that the surface slip property was relatively low and the scratch resistance was increased.

  When the applied load was 300 g, no visible scratches could be confirmed in Samples 1 to 4, but Samples 10 to 12 and Samples 14 to 16 were found to be easily scratched.

  From the above results, it can be seen that a scratch-resistant resin is preferably a soft, slippery material that is rich in elongation and resilience. Since the resin is soft, it is easy to disperse the load inside the resin against the pressing force when the touch pen is scratched. Further, by imparting slipperiness, the frictional resistance of the surface can be reduced, and the stress load on the resin can be reduced. Furthermore, it has the effect of suppressing breakage of the resin due to good elongation and resilience. Therefore, it can be considered that Samples 1 to 4 that have them have also been scratch-resistant even under a large load.

(Reflectance measurement before and after touch pen scratch test)
The reflectance of the transfer film before and after the touch pen scratch test was measured. The reflectance was measured using a reflection spectral film thickness meter (manufactured by Otsuka Electronics Co., Ltd., FE3000 automatic stage specification) that can be measured with a local measurement area. The measurement conditions are absolute reflectance measurement, the measurement mode is manual, the objective lens is set to X25, the baseline is adjusted with the Al reference, the reflectance of BK7 known as the reference is also measured, and the device is normal confirmed. Next, the concavo-convex pattern forming surface of the transfer film was placed on the objective stage side on the sample stage of the FE3000, and the height was adjusted so that the measurement focus coincided with the concavo-convex pattern surface. The measurement incident angle at this time was 10 to 22 ° with respect to the sample, and the measurement area was 8 μmφ.

  FIG. 9 shows the measurement results of the local reflectance of the transfer film before and after the touch pen scratch test. First, the reflectance (regular reflectance + diffuse reflectance) of each transfer film before the scratch test was measured. For example, Sample 2, Sample 5 and Sample 7 showed a reflectance of 0.8% or less in the wavelength range of 300 to 800 nm. In particular, in the wavelength range of 450 to 700 nm, the reflectance was 0.5% or less, and it was confirmed that there was a sufficient antireflection effect in the visibility region. The reflectance here is defined as the average reflectance of adjacent peaks (peaks) and valleys (valleys) of the interference waveform.

  Next, the reflectance after the touch pen scratch test was similarly measured. In Example 2 where the evaluation result of visual observation determined “◯”, the reflectance fluctuation before and after the test was hardly confirmed. In Example 5 determined as “Δ” in the evaluation result of visual observation, the reflectance was slightly high in the wavelength region of 550 nm or more. This is considered to be caused by partial collapse deformation of the concavo-convex structure as a result of observation by a scanning electron microscope. The absolute value of the reflectance is still kept low (the reflectance is 0.5% or less in the wavelength range of 450 nm to 700 nm), and it can be judged that the function as an antireflection is sufficient.

  On the other hand, Comparative Example 2, which was clearly marked and marked as “x” in the visual observation evaluation result, showed a high reflectance of 1.5% or more in the entire range of 300 nm to 800 nm. As can be judged from scanning electron micrographs, it was found that the concavo-convex structure was completely crushed at most scars and there was no function as an antireflection.

(Surface resistivity measurement)
The surface resistivity of the sample surface was measured. The apparatus used was a superinsulator (SM-8220, for high resistance). The measurement conditions are as follows. Electrode: Ring electrode SME8310 for flat plate sample, voltage 500V, charge 50 seconds, measurement 10 seconds. The measurement was carried out after standing for 3 days at a constant temperature and humidity of 23 ° C. and 50% humidity. The results of the surface resistivity measurement are shown in Table 7 below.

  As a result, Sample 2 and Sample 4 showed a resistivity that was one or two orders of magnitude smaller than the other samples. This is considered to be caused by having a high water content by having polyethylene glycol in the resin composition. It is expected to have an effect of preventing dust such as dust caused by static electricity.

  INDUSTRIAL APPLICABILITY The present invention has an effect of being able to realize a cured resin having excellent toughness and high scratch resistance, and can be suitably used particularly as an antireflection film or an antireflection film used in solar cell panels and liquid crystal televisions. It is.

DESCRIPTION OF SYMBOLS 1 Resin hardened | cured material 2, 3 Optical element 10 Fine uneven structure 11 The vertex of a convex part 12 The bottom of a recessed part 13 Base material 100, 101 Resin hardened | cured material layer

Claims (9)

It is a cured resin with a fine uneven structure formed on the surface,
A cured product of polyethylene glycol di (meth) acrylate and urethane di (meth) acrylate, having a surface elastic modulus of 0.01 GPa to 2 GPa and a surface hardness of 0.01 GPa to 0.2 GPa Cured resin.   The cured resin product according to claim 1, comprising at least one of a silicone-based additive and a fluorine-based additive.   The number of polymerizable functional groups of the said hardened | cured material is 2 or less, The resin hardened | cured material of Claim 1 or Claim 2 characterized by the above-mentioned.   The resin curing according to any one of claims 1 to 3, comprising 10 parts by mass to 500 parts by mass of the urethane di (meth) acrylate with respect to 100 parts by mass of the polyethylene glycol di (meth) acrylate. object.   The resin curing according to any one of claims 1 to 4, wherein N-vinylpyrrolidone is contained in an amount of more than 0 parts by weight and 500 parts by weight or less with respect to 100 parts by weight of the polyethylene glycol di (meth) acrylate. object.   The fine concavo-convex structure has a pitch between adjacent convex portions of 100 nm or more and 1000 nm or less, and an aspect ratio of the concave portion or the convex portion is 0.1 or more and 2.5 or less. The resin cured product according to claim 5.   The cured resin product according to any one of claims 1 to 6, wherein the concave or convex portions of the fine concavo-convex structure are arranged in a hexagonal lattice shape in a plan view.   8. Any one of claims 1 to 7, wherein ((reflectance after scratch test−reflectance before scratch test) / reflectivity before scratch test) × 100 in the entire visible range is 60% or less. Hardened resin product according to crab.   An optical element comprising: a base material; and a resin layer comprising the resin cured product according to claim 1 provided on the base material.