Active energy ray-curable composition, hard coating film and laminate thereof

Abstract

The present invention provides an active energy ray-curable composition for forming a hard coating layer on a transparent substrate, a hard coating film using the same, and a laminate thereof, wherein the active energy ray-curable composition suppresses scratches of a display in a production process, the generation of curling caused by curing shrinkage, and the dissolution of an ultraviolet blocker in a saponification treatment solution. The present invention solves the problem by an active energy ray-curable composition for forming a hard coating layer on a transparent substrate, the active energy ray-curable composition comprising: an active energy ray-curable component (A) containing a specific (meth)acrylate, an ultraviolet blocker (B) having a molecular weight of 300 or more, a specific photopolymerization initiator (C), and a solvent (D).

Description

Technical Field

[0001] The present invention relates to an active energy ray-curable composition for forming a hard coat layer on a transparent substrate, and a hard coat film and a laminate thereof using the same.

[0002] More specifically, the present invention relates to an active energy ray-curable composition for forming a hard coat layer that can be applied to displays of televisions, notebook computers, mobile phones, smartphones, and the like, a hard coat film using the same, and a laminate thereof. Background Art

[0003] In the use of displays for televisions, notebook computers, mobile phones, smartphones, etc., in addition to the liquid crystal displays (LCDs) that have been commonly used in the past, various types of displays have been developed, and products that utilize various features have been launched on the market.

[0004] Among them, organic electroluminescent (EL) displays are rapidly expanding in various applications such as televisions and smartphones, but the light-emitting elements used in organic EL displays are weak to water vapor and impurity gases generated by the constituent materials. Therefore, as a countermeasure for degradation caused by water vapor, an isolation layer (inorganic layer) of an inorganic compound is provided on the substrate, or as a countermeasure for impurity gases, volatile components are reduced, thereby protecting the light-emitting elements.

[0005] In addition, the influence of external factors such as heat and ultraviolet rays is also great. In particular, the influence of ultraviolet rays is not limited to the high-energy region on the low-wavelength side. Even ultraviolet rays near the wavelength of 400nm close to visible light have a great influence on degradation. Therefore, considering the use outdoors, in order to protect the internal structure from the influence of ultraviolet rays invading from the outside of the display, it is required to have a function of blocking ultraviolet rays.

[0006] On the other hand, a polarizing plate is stacked in a conventional organic EL display. The polarizing plate used in an organic EL display is called a circular polarizing plate, which is different from the light transmission control used in a liquid crystal display. The electrode portion constituting the organic EL display is made of metal, and in the electrode portion, incident light from the outside is scattered inside the display. In order to avoid the influence of the incident light from the outside, a circular polarizing plate is stacked.

[0007] Polarizers are usually made of water-soluble polyvinyl alcohol (PVA), which is dyed with iodine and then stretched into a film. Since PVA polarizers are hygroscopic, triacetyl cellulose (TAC) films with excellent non-flammability, appearance (transparency) and insulation are used as protective films.

[0008] When bonding a polarizing plate made of PVA to a TAC film, the surface of the TAC film needs to be saponified with caustic soda to hydrolyze part of the acetyl groups (—O═COCH groups) on the surface of the TAC film into hydroxyl groups (—OH) that are hydrophilic groups.

[0009] The saponification treatment of the TAC film is carried out by immersing the TAC film in an alkaline aqueous solution such as sodium hydroxide (NaOH) or potassium hydroxide (KOH). When the polarizer is used for polarization in a display, other functional layers such as a hard coating (HC), anti-glare (AG), anti-reflection (AR), and antistatic (AS) are often stacked on the side opposite to the side bonded to the polarizer.

[0010] In order to maintain the adhesion between the PVA polarizer and the TAC film, the step of laminating these functional layers is usually performed before the saponification treatment with caustic alkali.

[0011] Therefore, if a saponification treatment using a strong alkali is performed after lamination of the functional layers, the functional layers that have been laminated with great effort may be damaged, resulting in a disadvantageous situation in which the functions are degraded.

[0012] In addition, devices with displays, especially mobile devices such as laptops, mobile phones, smartphones, tablets, and smart watches, attach importance to portability, so they are being promoted to be lightweight and miniaturized, and research is being conducted on the multifunctionalization and thin filmization of functional layers in the display structure. In the research on thin filmization, the film thickness of the base film is being reduced, and thin films of 100μm to 50μm or less are also being studied.

[0013] When an active energy ray-cured material is applied to a film, warping and curling due to shrinkage during curing are often generated. This tendency becomes more prominent as the film substrate becomes thinner.

[0014] Since the display is constructed by laminating functional layers, the curling of the substrate after forming the functional layers will lead to poor workability in subsequent steps and a decrease in yield.

[0015] In Japanese Patent Gazette No. 2012-211305 and Japanese Patent Gazette No. 2022-000694, as a study on the multifunctionalization and thin filmization of functional layers in the display structure, a transparent double-sided adhesive sheet is exemplified, which is arranged between the viewing side of the polarizing layer and the display part of the organic EL display to integrate the two components. The above-mentioned transparent double-sided adhesive sheet has at least one layer of ultraviolet absorption layer to reduce the transmittance of light with a wavelength of 380nm.

[0016] However, when adding a UV blocker to a double-sided adhesive sheet, the amount added is naturally limited from the perspective of preventing seepage and adhesive performance. Therefore, due to the thin film of the component, the UV rays incident on the display part cannot be fully blocked, and the adverse effects on the display cannot be prevented.

[0017] On the other hand, when the UV blocking functional layer is laminated on the opposite side of the TAC film that is in close contact with the PVA polarizer, the UV blocking agent sometimes dissolves from the UV blocking functional layer due to the saponification treatment of the TAC film, causing an increase in the UV transmittance and dissolution (contamination) of the UV blocking agent in the saponification treatment solution.

[0018] As a countermeasure, Japanese Patent Publication No. 2007-308670 exemplifies a method of selectively performing saponification on the surface opposite to the TAC film surface provided with a UV-curable functional layer, but fails to eliminate the influence of saponification on the UV-blocking layer. Furthermore, if the cross-linking density of the functional layer is increased, there are problems such as curling due to curing shrinkage. Although it is also considered to pre-paste a protective film during the saponification treatment, it is believed that there will be problems such as deterioration and cost increase caused by the increase in steps. On the other hand, it is also necessary to suppress the influence of UV blockers on UV curing, and improvements are still needed.

[0019] Furthermore, since the TAC film has high water vapor permeability, a polarizing plate bonded with the TAC film as a protective film may deteriorate under moist heat, for example, under conditions of a temperature of 70° C. and a relative humidity of 90%.

[0020] Therefore, a method of solving the above-mentioned problem by using a resin film having a lower water vapor permeability than the TAC film as a protective film has been proposed. For example, a method of using a polyethylene terephthalate resin film or an acrylic resin film as a protective film is known.

[0021] As a composition for forming an acrylic resin film, for example, International Publication No. 2020 / 209264 discloses an active energy ray-curable resin composition, which contains: a polyurethane (meth) acrylate resin (A) having a weight average molecular weight of 1500 to 30000; a (meth) acrylate compound (B) having a specific amount of one or more and two or less (meth) acryloyl groups in one molecule; and a (meth) acrylate compound (C) having three or more (meth) acryloyl groups in one molecule. In addition, International Publication No. 2022 / 25175 discloses a photocurable resin composition, which contains polyurethane (meth) acrylate (A); a (meth) acrylate monomer (B) containing at least a difunctional (meth) acrylate monomer (b1) and a hexafunctional (meth) acrylate monomer (b2); a photopolymerization initiator (C); and a leveling agent (D). Furthermore, Japanese Patent Application Laid-Open No. 2020-128558 discloses a resin composition comprising: an isocyanuric acid ring-containing polyurethane (meth)acrylate compound A including a compound A-1 having a specific structure; an isocyanuric acid ring-containing tri(meth)acrylate compound B including a compound B-1 having a specific structure; and a triazine-based ultraviolet absorber C. Japanese Patent Application Laid-Open No. 2022-034529 discloses a curable resin composition comprising: (A) (meth)acrylate; (B) a modifier having a molecular weight greater than that of (A) (meth)acrylate; (C) an ultraviolet absorber; and (D) a solvent.

[0022] Even when a film other than the TAC film is used as the protective film, since the same production line as the TAC film is used, it may come into contact with the saponification solution, and the ultraviolet shielding agent may be eluted (contaminated) in the saponification solution. Summary of the invention

[0023] Problem that the invention aims to solve

[0024] The present invention provides an active energy ray-curable composition for forming a hard coating layer on a transparent substrate, a hard coating film using the same, and a laminate thereof. The active energy ray-curable composition suppresses scratches on a display during a production process, curling caused by curing shrinkage, and dissolution of an ultraviolet shielding agent in a saponification treatment solution.

[0025] Solutions for solving problems

[0026] The present inventors have conducted intensive studies on the above-mentioned problems and, as a result, have found that the above-mentioned problems can be solved by using the active energy ray-curable composition described below, thereby completing the present invention.

[0027] [1]: An active energy ray-curable composition for forming a hard coating layer on a transparent substrate, the active energy ray-curable composition comprising an active energy ray-curable component (A), an ultraviolet shielding agent (B), a photopolymerization initiator (C) and a solvent (D), wherein the active energy ray-curable component (A) comprises all of the following (a1), (a2) and (a3):

[0028] (a1) a polyfunctional urethane (meth)acrylate having 6 or more (meth)acryloyl groups and a urate ring skeleton;

[0029] (a2) a multifunctional polyurethane (meth)acrylate having 4 to 15 (meth)acryloyl groups and a weight average molecular weight of 500 to 15,000 (excluding (a1));

[0030] (a3) other multifunctional (meth)acrylates,

[0031] The molecular weight of the ultraviolet shielding agent (B) is 300 or more, and the photopolymerization initiator (C) includes at least one of an oxime ester compound and a phosphine oxide compound.

[0032] [2]: The active energy ray-curable composition according to [1], wherein the mass ratio (a1) / (a2) of (a1) and (a2) contained in the active energy ray-curable component (A) is 50 / 50 to 70 / 30.

[0033] [3]: A hard coating film comprising a hard coating layer of a cured product of the active energy ray-curable composition according to [1] or [2] on a transparent substrate.

[0034] [4]: The hard coat film according to [3], wherein the transmittance (ta) of the hard coat film at a wavelength of 380 nm is 4% or less and the transmittance (tb) of the hard coat film at a wavelength of 420 nm is 70% or more.

[0035] [5]: The hard coating film according to [3] or [4], wherein the hard coating film satisfies the following formula (2):

[0036] Formula (2) (tc)-(ta)≤1%

[0037] (ta): transmittance of the hard coating film not immersed in the sodium hydroxide aqueous solution at a wavelength of 380 nm,

[0038] (tc): Transmittance at a wavelength of 380 nm of the hard coating film after being immersed in a sodium hydroxide aqueous solution, washed with water and dried.

[0039] [6]: A laminate comprising the hard coat film according to any one of [3] to [5] and a circularly polarizing functional layer.

[0040] Effects of the Invention

[0041] According to the present invention, there can be provided an active energy ray-curable composition for forming a hard coat layer, a hard coat film using the same, and a laminate thereof, which suppresses scratches on a display during a production process, curling due to curing shrinkage, and elution of an ultraviolet shielding agent in a saponification treatment solution. DETAILED DESCRIPTION

[0042] Hereinafter, the present invention will be described in detail. In addition, as long as it complies with the gist of the present invention, other embodiments are certainly also included in the scope of the present invention. In addition, the numerical range determined by using "to" in this specification is the range including the numerical values ​​recorded before and after "to" as the lower limit and upper limit.

[0043] First, the terms used in this specification are explained.

[0044] In this specification, when "(meth)acrylic acid", "(meth)acryloyl" and "(meth)acrylate" are expressed, they respectively mean "acrylic acid or methacrylic acid", "acryloyl or methacryloyl" and "acrylate or methacrylate" unless otherwise specified.

[0045] In addition, an “active energy ray-curable composition for forming a hard coat layer on a transparent substrate” is sometimes referred to as a “hard coat layer-forming composition”, “(a1) a polyurethane (meth)acrylate having 6 or more (meth)acryloyl groups and a urethane ring skeleton” is referred to as a “polyurethane (meth)acrylate (a1)”, “(a2) a polyfunctional polyurethane (meth)acrylate having 4 or more and 15 or less (meth)acryloyl groups and a weight average molecular weight of 500 or more and 15,000 or less (excluding (a1))” is referred to as a “polyfunctional polyurethane (meth)acrylate (a2)”, and “(a3) other polyfunctional (meth)acrylates” is referred to as a “polyfunctional (meth)acrylate (a3)”. Unless otherwise specified, the various components appearing in this specification can be used alone or in combination of two or more.

[0046] <Active energy ray-curable component (A)>

[0047] The active energy ray-curable component (A) contains all of the following (a1), (a2), and (a3).

[0048] (a1) A polyfunctional urethane (meth)acrylate having 6 or more (meth)acryloyl groups and having a urate ring skeleton.

[0049] (a2) A multifunctional urethane (meth)acrylate having 4 to 15 (meth)acryloyl groups and a weight average molecular weight of 500 to 15,000 (excluding (a1)).

[0050] (a3) Other multifunctional (meth)acrylates.

[0051] The multifunctional urethane (meth)acrylate refers to an oligomer having a urethane bond and having two or more (meth)acrylate groups.

[0052] <Multifunctional urethane (meth)acrylate (a1)>

[0053] Polyurethane (meth) acrylate (a1) has 6 or more (meth) acryloyl groups and has a urea ester ring skeleton. The urea ester ring skeleton is a trimer of an isocyanate compound having a nitrogen atom and is a six-membered ring structure. By having 6 or more (meth) acryloyl groups, the crosslinking density increases, the hardness and scratch resistance of the hard coating surface are excellent, and the curling of the hard coating can be suppressed. The detailed factors that suppress curling are not yet clear, but it is believed that the ring structure of the urea ester ring skeleton portion contributes to stress relaxation to a large extent.

[0054] A compound having three (meth)acryloyl groups and a urate ring skeleton is also relatively easy to obtain, but is not preferred because the hardness and scratch resistance of the hard coating surface are insufficient due to a low crosslinking density.

[0055] Specific examples of the urethane (meth)acrylate (a1) include a reaction product of an isocyanurate (trimer) of a diisocyanate and a poly(meth)acrylate compound having a hydroxyl group, and a reaction product of an isocyanurate (trimer) of a polyisocyanate and a polyol and a poly(meth)acrylate compound or a mono(meth)acrylate compound having a hydroxyl group. From the viewpoint of achieving excellent hardness and scratch resistance on the surface of the hard coating film, a reaction product of an isocyanurate (trimer) compound of a diisocyanate and a poly(meth)acrylate compound having one hydroxyl group and two or more (meth)acryloyl groups is preferred.

[0056] Examples of the diisocyanate include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, and diphenylmethane diisocyanate; hydrogenated products of the above aromatic isocyanates; and aliphatic diisocyanates such as isophorone diisocyanate and hexamethylene diisocyanate.

[0057] Examples of the mono(meth)acrylate having one hydroxyl group include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate. Examples of the poly(meth)acrylate having one hydroxyl group include pentaerythritol tri(meth)acrylate and dipentaerythritol penta(meth)acrylate, but are not limited thereto.

[0058] Examples of the polyol include ethylene glycol, polyethylene glycol, polypropylene glycol, glycerin, trimethylolpropane, cyclohexanediol, cyclohexanedimethanol, and tricyclodecane dimethanol, but the polyol is not limited to these.

[0059] <Multifunctional urethane (meth)acrylate (a2)>

[0060] The multifunctional polyurethane (meth)acrylate (a2) is a polyfunctional polyurethane (meth)acrylate having 4 or more and 15 or less (meth)acryloyl groups and having a weight average molecular weight of 500 to 15000 (excluding (a1)). The weight average molecular weight of the multifunctional polyurethane (meth)acrylate (a2) is preferably 1000 to 5000. The weight average molecular weight (Mw) is a polystyrene-converted weight average molecular weight determined by gel permeation chromatography (GPC). The weight average molecular weight can be measured by the method described in the [Examples] section.

[0061] The polyfunctional urethane (meth)acrylate (a2) can achieve a balance among crosslinking density, flexibility, and substrate adhesion by using the urethane (meth)acrylate (a1), thereby suppressing the occurrence of scratches and curling (warping), and further reducing the elution of the ultraviolet shielding agent.

[0062] The multifunctional polyurethane (meth) acrylate (a2) includes, for example, a polyfunctional polyurethane (meth) acrylate obtained by reacting a polyisocyanate with a mono(meth) acrylate or poly(meth) acrylate having a hydroxyl group; a polyfunctional polyurethane (meth) acrylate obtained by reacting an isocyanate group-containing polyurethane prepolymer obtained by reacting a polyol with a polyisocyanate under conditions in which the isocyanate group is excessive with a mono(meth) acrylate or poly(meth) acrylate having a hydroxyl group, etc. Alternatively, it can also be obtained by reacting a hydroxyl-containing polyurethane prepolymer obtained by reacting a polyol with a polyisocyanate under conditions in which the hydroxyl group is excessive with a (meth) acrylate having an isocyanate group.

[0063] The following is a method for producing polyurethane (meth) acrylate (a2), but this is only an example and is not limited to these. For example, polyurethane (meth) acrylate (a2) can be obtained by stirring polyisocyanate and hydroxyl-containing (meth) acrylate in the presence of an appropriate urethanization catalyst at 60 to 100° C. for 4 to 8 hours in an oxygen environment.

[0064] Specific examples of the urethanization catalyst include copper naphthenate, cobalt naphthenate, zinc naphthenate, dibutyltin dilaurate, triethylamine, 1,4-diazabicyclo[2.2.2]octane, 2,6,7-trimethyl-1,4-diazabicyclo[2.2.2]octane, etc. Among these, dibutyltin dilaurate, etc. are particularly preferred.

[0065] Polyisocyanates include, for example, aliphatic diisocyanates, aromatic diisocyanates, etc., and aliphatic diisocyanates include hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, etc., and aromatic diisocyanates include toluene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, etc. The bonding position of the isocyanate group and the aromatic group may be any one of the ortho position, meta position, and para position. In addition, the diisocyanate may also form an isocyanurate ring in the form of a trimer.

[0066] Among them, aliphatic diisocyanates are preferred from the viewpoint of suppressing yellowing when used for optical purposes.

[0067] The number of (meth)acryloyl groups and the weight average molecular weight can be adjusted by combining a polyol, a polyisocyanate, and a hydroxyl group-containing mono(meth)acrylate or poly(meth)acrylate.

[0068] Examples of the hydroxyl group-containing (meth)acrylate include trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, 2-hydroxyethyl (meth)acrylate, 1-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 1-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. Hydroxyl-containing (meth)acrylates such as 8-hydroxyoctyl (meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, ethyl-α-(hydroxymethyl) (meth)acrylate, monofunctional glycerol (meth)acrylate, or (meth)acrylates having a hydroxyl group at the terminal by ring-opening addition of these (meth)acrylates and ε-caprolactone, and alkylene oxide-added (meth)acrylates obtained by repeatedly adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to the above-mentioned hydroxyl-containing (meth)acrylates.

[0069] From the viewpoint of increasing the crosslinking density and suppressing the occurrence of scratches, curling, and dissolution of ultraviolet shielding materials, (meth)acrylates having 2 to 5 (meth)acryloyl groups are preferred. Specifically, it is preferred to include at least one selected from trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate.

[0070] Examples of the polyurethane (meth)acrylate (a2) whose molecular weight and number of acryloyl groups are disclosed in catalogs and the like include: UV1700B (molecular weight 2000, number of acryloyl groups 10), UV7600B (molecular weight 1400, number of acryloyl groups 6), UV7605B (molecular weight 1100, number of acryloyl groups 6), UV7610B (molecular weight 1100, number of acryloyl groups 9), UV7629EA (molecular weight 4100, number of acryloyl groups 9, volatile components 35%), UV7640B (molecular weight 1500, number of acryloyl groups 6 to 7), and UV7650B (molecular weight 2300, number of acryloyl groups 4 to 5) manufactured by Mitsubishi Chemical Corporation; PU610 (molecular weight 1800, number of acryloyl groups 6) and MU9500 (molecular weight 3200, number of acryloyl groups 10) manufactured by Nippon Kayaku Co., Ltd.; KAYARAD DPHA-40H (molecular weight 2000, number of acryloyl groups 10), UX-5000 (molecular weight 1500, number of acryloyl groups 6), UX-5102D-M20 (molecular weight 3500, number of acryloyl groups 6, volatile components 20%), UX-5103 (molecular weight 7000, number of acryloyl groups 6) and UX-5005 (molecular weight 4500, number of acryloyl groups 9) manufactured by Negomi Industries Co., Ltd.; ARTRESIN UN-3320HA (molecular weight 1500, number of acryloyl groups 6), UN-3320HC (molecular weight 1500, number of acryloyl groups 15, volatile components 5%), UN-904 (molecular weight 4900, number of acryloyl groups 10), UN-906S (molecular weight 1000, number of acryloyl groups 6), UN-901T (molecular weight 4000, number of acryloyl groups 9, volatile components 20%) and UN-952 (molecular weight 6500-11000, number of acryloyl groups 10), etc., but not limited to these.

[0071] <Multifunctional (meth)acrylate (a3)>

[0072] The polyfunctional (meth)acrylate (a3) ​​is a polyfunctional (meth)acrylate other than (a1) and (a2).

[0073] Examples of the polyfunctional (meth)acrylate (a3) ​​include various diol (meth)acrylates, trimethylolethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate and other polyol poly(meth)acrylates, tri(meth)acrylates of isocyanurates of various diisocyanates, and polyurethane (meth)acrylates other than the polyfunctional polyurethane (meth)acrylate (a1) and the polyfunctional polyurethane (meth)acrylate (a2), but are not limited thereto.

[0074] Pentaerythritol triacrylate (a3-1), pentaerythritol tetraacrylate (a3-2), dipentaerythritol pentaacrylate (a3-3) and dipentaerythritol hexaacrylate (a3-4) remaining in the synthesis of urethane (meth)acrylate (a1) and urethane (meth)acrylate (a2) can be used as they are.

[0075] Examples of polyurethane (meth)acrylates other than polyfunctional polyurethane (meth)acrylate (a1) and polyfunctional polyurethane (meth)acrylate (a2) include: polyfunctional polyurethane (meth)acrylates having 2 to 5 (meth)acryloyl groups and a urethane ring skeleton; polyfunctional polyurethane (meth)acrylates having a (meth)acryloyl group number outside the range of 4 to 15 or a weight average molecular weight outside the range of 500 to 15,000; and the like.

[0076] Examples of the polyfunctional acrylate having 2 to 5 (meth)acryloyl groups and having a urate ring skeleton include isocyanuric acid EO-modified diacrylate (acryloyl group number: 2) such as ARONIX M-215 manufactured by Toagosei Co., Ltd.;

[0077] Isocyanuric acid EO-modified diacrylate and / or triacrylate (number of acryloyl groups: 2 to 3) such as ARONIX M-313 manufactured by Toagosei Co., Ltd. and ARONIX M-315 manufactured by Toagosei Co., Ltd.;

[0078] ε-caprolactone-modified (2-acryloyloxy)isocyanurate (number of acryloyl groups: 3) such as NK ESTER A-9300-1CL manufactured by Shin-Nakamura Chemical Co., Ltd.; and

[0079] NK ESTER A-9300 manufactured by Shin-Nakamura Chemical Co., Ltd., SARTOMER SR368 manufactured by Arkema;

[0080] NEW FRONTIER TEICA (GX-8430) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; and

[0081] Tris(2-acryloyloxyethyl)isocyanurate (number of acryloyl groups: 3) such as FANCRYL FA-731A manufactured by Showa Denko Industries, Ltd., etc., but the present invention is not limited to these.

[0082] Examples of the multifunctional polyurethane (meth)acrylate having a (meth)acryloyl group number outside the range of 4 to 15 or a weight average molecular weight outside the range of 500 to 15,000 include, but are not limited to, UV-6300B (molecular weight 3,700, acryloyl group number 3) manufactured by Mitsubishi Chemical Corporation, ARTRESIN UN-5500 (molecular weight 50,000, acryloyl group number 12.5, volatile component 50%), UN-5507 (molecular weight 17,000, acryloyl group number 15.5, volatile component 50%), and UN-905 (molecular weight 40,000 to 200,000, acryloyl group number 15, volatile component 40%) manufactured by Negami Industries Co., Ltd., and Miramer SC2152 (molecular weight 20,787, acryloyl group number 15) manufactured by Migen Corporation.

[0083] The mass ratio (a1) / (a2) of the multifunctional polyurethane (meth) acrylate (a1) and the multifunctional polyurethane (meth) acrylate (a2) contained in the active energy ray curable component (A) is preferably 20 / 80 to 80 / 20. The above-mentioned mass ratio (a1) / (a2) is more preferably 40 / 60 to 60 / 40. By making (a1) / (a2) 20 / 80 to 80 / 20, it is possible to suppress the dissolution of scratches and ultraviolet blockers in the process, as well as the adhesion and curling with the substrate. In addition, from the viewpoint of making the balance of these characteristics more excellent, the above-mentioned mass ratio (a1) / (a2) is also more preferably 50 / 50 to 70 / 30.

[0084] The content of the polyfunctional polyurethane (meth) acrylate (a1), the polyfunctional polyurethane (meth) acrylate (a2) and the polyfunctional (meth) acrylate (a3) ​​in 100% by mass of the active energy ray curable component (A) is preferably 12 to 48% by mass for the polyfunctional polyurethane (meth) acrylate (a1), 20 to 80% by mass for the polyfunctional polyurethane (meth) acrylate (a2) and 8 to 32% by mass for the polyfunctional (meth) acrylate (a3). By adjusting to this range, high scratch resistance and high substrate adhesion can be achieved, as well as the generation of curling and the dissolution of the ultraviolet shielding agent can be suppressed.

[0085] 《Ultraviolet Blocker (B)》

[0086] The UV blocker (B) is a material that absorbs ultraviolet rays. The UV blocker (B) uses a UV blocker with a molecular weight of 300 or more. When the molecular weight is less than 300, it is easy to dissolve in the saponification process and is not preferred. The UV blocker (B) preferably has a molecular weight of 100,000 or less. If the molecular weight is 100,000 or less, the pencil hardness when made into a hard coating is excellent. In addition, from the perspectives of preventing seepage, preventing dissolution in the saponification process, and price, it is preferred that the UV blocker has excellent ultraviolet absorption ability with a small amount of addition.

[0087] Examples of such ultraviolet shielding agents include benzotriazole-based, hydroxyphenyltriazine-based, and benzophenone-based ultraviolet shielding agents.

[0088] From the perspective of minimizing adverse effects on other physical properties of the coating film, hydroxyphenyltriazine-based and benzotriazole-based ultraviolet shielding agents are preferred. The ultraviolet shielding agents may be commercially available products as such or two or more commercial products may be mixed and used. Examples of commercially available ultraviolet shielding agents include the “TINUVIN” series (benzotriazole and hydroxyphenyltriazine) and “CHIMASSORB” series manufactured by BASF, the “UVINUL” series (benzophenone and triazine) manufactured by BASF, the “RUVA” series (benzotriazole) manufactured by Otsuka Chemical Co., Ltd., the “Adekastab LA” series (benzotriazole and triazine) manufactured by Adecco Co., Ltd., the “Eversorb” series (benzotriazole, triazine, benzophenone) manufactured by Nagako Chemical Co., Ltd., and the “VANARESIN UVA” series (benzotriazole, etc.) manufactured by Shin-Nakamura Chemical Co., Ltd.

[0089] The content of the ultraviolet blocker (B) is, for example, 0.5 to 20% by mass, preferably 2 to 15% by mass, relative to 100% by mass of the active energy ray curable component (A). By making it 0.5 to 20% by mass, it is possible to ensure the ultraviolet rays required for photoexcitation of the photopolymerization initiator while fully blocking the ultraviolet rays, and the curability of the coating film can be improved.

[0090] 《Photopolymerization initiator (C)》

[0091] The photopolymerization initiator (C) contains at least one of an oxime ester compound and a phosphine oxide compound.

[0092] The active energy ray-curable composition of the present invention contains an ultraviolet shielding agent to shield ultraviolet rays of wavelengths around 400 nm close to visible light that affect the laminate, thereby shielding ultraviolet rays required for photoexcitation of the photopolymerization initiator. Therefore, at least one highly sensitive initiator selected from oxime ester compounds and phosphine oxide compounds that can efficiently generate free radicals even under weak ultraviolet rays is contained in as little amount as possible.

[0093] Specifically, phosphine oxide compounds such as 2,4,6-trimethylbenzoindiphenylphosphine oxide and oxime ester compounds such as Irgacure OXE01, Irgacure OXE02, and Irgacure OXE03 manufactured by BASF are preferred, and oxime ester compounds are particularly preferably used.

[0094] The amount of the photopolymerization initiator (C) is preferably 0.1 to 30% by mass, more preferably 5 to 20% by mass, relative to 100% by mass of the total active energy ray-curable component (A). Within this range, a sufficient polymerization initiation effect can be obtained, and adhesion and scratch resistance can be effectively improved.

[0095] Furthermore, other photopolymerization initiators other than the oxime ester compound and the phosphine oxide compound may be used in combination.

[0096] The other photopolymerization initiators are not particularly limited as long as they have a function of initiating radical polymerization by light excitation, and examples thereof include acetophenone compounds, benzoin compounds, benzophenone compounds, phosphine oxide compounds, ketal compounds, anthraquinone compounds, and thioxanthone compounds.

[0097] Specific examples thereof include benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, diethoxyacetophenone, benzil dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 2,4,6-trimethylbenzoin diphenylphosphine oxide, N,N-dimethylaminobenzoic acid isopentyl ester, 2-chlorothioxanthone, and 2,4-diethylthioxanthone.

[0098] In addition, the thioxanthone compound functions as a photopolymerization initiator when used alone, and also functions as a photosensitizer when used in combination with other photopolymerization initiators.

[0099] Solvent (D)

[0100] The active energy ray-curable composition for forming a hard coat layer of the present invention may be diluted with a solvent.

[0101] A known solvent can be used, and examples thereof include dimethyl carbonate, ethyl acetate, n-butyl acetate, acetone, methyl ethyl ketone, 1,3-dioxolane, methyl isobutyl ketone, isopropyl alcohol, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate, but are not limited thereto.

[0102] The solvent (D) is preferably 40 to 80% by mass, more preferably 40 to 70% by mass, and further preferably 45 to 65% by mass in 100% by mass of the active energy ray-curable component (A) for forming the hard coat layer. When it is 40% by mass or more, the substrate permeability is high, thereby further improving the adhesion, and when it is 80% by mass or less, the substrate permeability is not too high, and the deterioration of the coating haze or scratch resistance can be further suppressed.

[0103] <Sensitizer (F)>

[0104] The hard coat layer-forming composition of the present invention may contain a photopolymerization initiator (C) and a sensitizer. Examples of the sensitizer include amine sensitizers, anthracene sensitizers, and thioxanthone sensitizers. The sensitizers may be used alone or in combination of two or more.

[0105] Examples of the amine sensitizer include trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate (EPA), isoamyl p-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, N,N-dimethylbenzylamine, and 4′-bis(diethylamino)benzophenone.

[0106] Examples of the anthracene-based sensitizer include 9,10-dibutoxyanthracene (DBA), 9,10-diethoxyanthracene (DEA), 9,10-dipropoxyanthracene, and 9,10-bis(2-ethylhexyloxy)anthracene.

[0107] Examples of the thioxanthone-based sensitizer include thioxanthone-based sensitizers such as 2,4-diethylthioxanthone (DETX), 2-isopropylthioxanthone (ITX), and 4-isopropylthioxanthone.

[0108] Representative examples of commercially available products include KAYACURE KAYACUREEPA manufactured by Nippon Kayaku Co., Ltd. for amine-based sensitizers, Anthracure UVS-1331 (DBA) and UVS-1101 (DEA) manufactured by Airwater Chemical Co., Ltd. for anthracene-based sensitizers, and Omnirad DETX and ITX manufactured by Aeginmon Resins GmbH of the Netherlands for thioxanthone-based sensitizers.

[0109] A sensitizer having absorption also at around 420 nm which is on the longer wavelength side than the ultraviolet blocking region is preferred, and a thioxanthone sensitizer or a combination of an amine sensitizer and a thioxanthone sensitizer is preferred.

[0110] When using a sensitizer, the content thereof is preferably 1 to 15% by mass relative to 100% by mass of the active energy ray-curable component (A).

[0111] [Active Energy Ray-Curable Composition for Forming a Hard Coat Layer on a Transparent Substrate (Hard Coat Layer-Forming Composition)]

[0112] The hard coat layer-forming composition of the present invention contains an active energy ray-curable component (A), an ultraviolet shielding agent (B), a photopolymerization initiator (C), and a solvent (D).

[0113] The hard coat layer-forming composition of the present invention may contain other additives as required. Examples of other additives include plasticizers, surface conditioners, light stabilizers, antioxidants, and polymerization inhibitors.

[0114] [Hard Coat]

[0115] The hard coating film of the present invention has a hard coating layer formed by curing the hard coating layer-forming composition on a transparent substrate.

[0116] The hard coating film of the present invention preferably has a transmittance (ta) of 4% or less at a wavelength of 380 nm and a transmittance (tb) of 70% or more at a wavelength of 420 nm.

[0117] From the viewpoint of suppressing yellowing, the transmittance (tb) at a wavelength of 420 nm is more preferably 75% or more, and even more preferably 80% or more.

[0118] By making the transmittance (ta) at a wavelength of 380nm less than 4%, the light in the ultraviolet region with a wavelength of less than 380nm, which is harmful to the organic EL display, is blocked, and the degradation of the organic EL display can be prevented. In addition, by making the transmittance (tb) at a wavelength of 420nm more than 70%, the accurate color reproduction of the display part of the organic EL display can be achieved.

[0119] Furthermore, the hard coating film of the present invention preferably satisfies the following formula (2):

[0120] Formula (2) (tc)-(ta)≤1%

[0121] (ta): transmittance at a wavelength of 380 nm of the hard coating film not immersed in the sodium hydroxide aqueous solution.

[0122] (tc): Transmittance at a wavelength of 380 nm of the hard coating film after being immersed in a sodium hydroxide aqueous solution, washed with water and dried.

[0123] By making (tc)-(ta)≤1%, the elution of the UV blocking agent in the saponification treatment solution can be reduced while protecting the organic EL display from harmful ultraviolet rays. The determination method of (ta) and (tc) is described in detail in the [Examples] section.

[0124] <Transparent substrate>

[0125] The transparent substrate used in the present invention can be any grade as long as it is optically transparent. Specifically, amorphous polyolefin resin films, polyester resin films, polyethylene terephthalate (PET) resin films, acrylic resin films, polycarbonate (PC) resin films, polysulfone resin films, alicyclic polyimide resin films, polycycloolefin (COP) resin films, triacetyl cellulose (TAC) films, etc. having a haze of less than 1.0% can be cited. Among these, polyethylene terephthalate resin films, acrylic resin films, polycarbonate resin films, and polycycloolefin resin films are preferred from the viewpoint of low water vapor permeability.

[0126] The thickness of the transparent substrate is not particularly limited, but is generally about 10 to 500 μm, particularly preferably 20 to 250 μm, from the perspectives of strength, workability such as handling, and thinness.

[0127] <Manufacturing of hard coating film>

[0128] The hard coat film can be produced by a conventionally known method such as coating a hard coat layer-forming composition on a transparent substrate, and is not particularly limited.

[0129] For example, after applying the hard coat forming composition of the present invention to a transparent substrate, the solvent is dried as needed, and then the applied hard coat forming composition is crosslinked and cured by irradiating it with active energy rays to obtain a hard coat film having a transparent substrate and a hard coat layer.

[0130] Examples of the coating method include bar coating, blade coating, spin coating, reverse coating, die coating, spray coating, roll coating, gravure coating, micro gravure coating, lip coating, air knife coating, and dipping.

[0131] As the active energy ray, ultraviolet rays emitted from a light source such as an electron beam, a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a carbon arc lamp, or a tungsten lamp can be used.

[0132] The thickness of the hard coating layer is not particularly limited as long as the hard coating property is maintained, and is usually 1 to 20 μm, preferably 2 to 15 μm. The total thickness of the hard coating layer and the mixed layer is not particularly limited, but is preferably 0.5 to 100 μm, more preferably 1.1 to 30 μm, and further preferably 1.2 to 25 μm in order to reduce interference unevenness.

[0133] The film thickness of the hard coating film is not particularly limited, but is preferably 50 to 300 μm, more preferably 81 to 100 μm, and further preferably 82 to 95 μm.

[0134] [Laminated body]

[0135] The laminate of the present invention has a hard coating film and a circularly polarized light functional layer. The hard coating film and the circularly polarized light functional layer may be directly laminated or may have another layer therebetween. The laminated hard coating film and the circularly polarized light functional layer have a structure of hard coating layer / transparent substrate / circularly polarized light functional layer.

[0136] The circularly polarized light functional layer has a laminated structure of a PVA polarizer and a phase difference layer, and the phase difference layer can be a phase difference TAC having a phase difference function. The phase difference TAC can also serve as TAC constituting the hard coat film. That is, the structure of hard coat layer / phase difference TAC / PVA polarizer is also referred to as a laminate in the present invention.

[0137] The method for producing the laminate is not particularly limited, and the circularly polarizing functional layer laminate can be formed by, for example, bonding the triacetyl cellulose surface of the hard coat film that does not have a hard coat layer to a PVA polarizer.

[0138] Example

[0139] <Weight average molecular weight (Mw)>

[0140] The weight average molecular weight is a polystyrene-converted weight average molecular weight measured using a gel permeation chromatograph "HLC-8220GPC" manufactured by Tosoh Corporation, wherein four separation columns, "TSK-GEL SUPER H5000", "TSK-GEL SUPER H4000", "TSK-GEL SUPER H3000" and "TSK-GEL SUPER H2000" manufactured by Tosoh Corporation, are connected in series, and tetrahydrofuran is used as the mobile phase at a temperature of 40°C and a flow rate of 0.6 ml / min.

[0141] <Measurement of Haze Value>

[0142] The haze value was determined using a spectrophotometer / haze meter "SH7000" manufactured by Nippon Denshoku Industries Co., Ltd., which was set in a constant temperature and humidity chamber at 23°C and 50% relative humidity (RH). The average value of n=3 under a D65 light source was taken as the haze value.

[0143] <Measurement of transmittance>

[0144] The obtained hard coat forming composition was applied on a transparent substrate using a bar coater No. 8, dried in a hot air oven for 1 minute, and then irradiated with ultraviolet light using a high-pressure mercury lamp with an output of 80 w / cm to cure the coating layer, thereby obtaining a hard coat film having a transparent substrate, an active energy ray curable composition for forming a hard coat layer, and a hard coat layer. The transmittance of the hard coat film having the hard coat layer at 380 nm and 420 nm was measured using a Hitachi High-Technologies Corporation spectrophotometer "UH5200" set in a constant temperature and humidity chamber at 23° C. and 50% RH.

[0145] <Difference in transmittance of hard coat film [(tc)-(ta)]>

[0146] The hard coating film was immersed in a 9 wt% NaOH aqueous solution at a liquid temperature of 50°C for 5 minutes, washed with water, and dried in a box oven at 100°C for 5 minutes, and then the transmittance (tc) at a wavelength of 380nm was measured. The difference between the transmittance (tc) and the transmittance (ta) of the untreated hard coating film (not immersed in the sodium hydroxide aqueous solution) at a wavelength of 380nm was calculated.

[0147] <Production of polyfunctional urethane (meth)acrylate (a1)>

[0148] (Synthesis Example 1) Polyurethane acrylate mixed liquid (P1): In a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel, 1325.6 parts by mass of ARONIX M306 (a mixture of 67.5% by mass of pentaerythritol triacrylate (PE-3A) (a3-1) having a molecular weight of 298 and 32.5% by mass of pentaerythritol tetraacrylate (PE-4A) (a3-2) having a molecular weight of 352, manufactured by Toagosei Co., Ltd.) and 0.1 parts by mass of NEOSTANN U-810 (a tin catalyst, manufactured by Nitto Kasei Co., Ltd.) were added, and after the liquid temperature was adjusted to 50° C., 1109.8 parts by mass of DESMODUR Z4470BA (manufactured by Sumika Covestro Co., Ltd., with a nonvolatile component of 70% by mass (volatile component butyl acetate), 85.8% by mass of isophorone diisocyanate (IPDI) trimer with a molecular weight of 667, and a polyisocyanate having a urate ring with an NCO content of 11.9% relative to the nonvolatile component). After the heating was completed, the temperature was raised to 80°C to react for 3 hours, and after confirming the disappearance of the peak of the isocyanate group in Fourier transform infrared spectroscopy (FT-IR), the temperature was lowered to room temperature to obtain a polyurethane acrylate mixed solution (P1) with a nonvolatile component of 86.7% by mass, which contained 77.1% by mass of a polyurethane acrylate (a1-1) with a weight average molecular weight of 1600 and 9 acryloyl groups, 20.8% by mass of pentaerythritol tetraacrylate (PE-4A) (a3-2) and 2.1% by mass of other compounds (e-1) without (meth)acryloyl groups.

[0149] (Synthesis Example 2) Polyurethane acrylate mixed liquid (P2): Into a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel, 1325.6 parts by mass of ARONIX M306 and 0.1 parts by mass of NEOSTANN U-810 were added, and after the liquid temperature became 50°C, 571.7 parts by mass of DURANATE TPA-100 (manufactured by Asahi Kasei Corporation, a polyisocyanate having a urate ring with a non-volatile content of 100 mass%, a hexamethylene diisocyanate (HDI) trimer with a molecular weight of 505 containing 88.3 mass% of the non-volatile content, and an NCO content of 23.1%) was added dropwise from the dropping funnel over a period of 30 minutes. After the heating was completed, the temperature was raised to 80°C and reacted for 3 hours. After confirming that the peak of the isocyanate group disappeared in FT-IR, the temperature was lowered to room temperature to obtain a polyurethane acrylate mixed solution (P2) with a non-volatile component of 100% by mass, which contained 76.1% by mass of a polyurethane acrylate (a1-2) having 9 acryloyl groups and a weight average molecular weight of 1400, 23.0% by mass of pentaerythritol tetraacrylate (PE-4A) (a3-2) and 0.9% by mass of other compounds (e-2) without a (meth)acryloyl group.

[0150] (Synthesis Example 3) Polyurethane acrylate mixed solution (P3): 4439.0 parts by mass of DESMODUR Z4470BA, 432.6 parts by mass of cyclohexyl dimethanol (molecular weight 144, hydroxyl value 389 mgKOH / g) and 0.1 parts by mass of NEOSTANN were added to a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer and a dropping funnel. U-810 was heated to 80°C and reacted for 3 hours. After confirming in FT-IR that the peak intensity of the isocyanate group reached half of that before the reaction, 865.0 parts by mass of 4-hydroxybutyl acrylate (molecular weight 144, hydroxyl value 389 mgKOH / g) was added and further reacted at 80°C for 3 hours. After confirming in FT-IR that the peak of the isocyanate group disappeared, the temperature was lowered to room temperature to obtain a polyurethane acrylate mixed solution (P3) with a non-volatile component of 100.0% by mass, which contained 96.0% by mass of a polyurethane acrylate (a1-3) having 6 acryloyl groups and a weight average molecular weight of 4000 and 4.0% by mass of other compounds (e-3) without a (meth)acryloyl group.

[0151] <Production of multifunctional urethane (meth)acrylate (a2)>

[0152] (Synthesis Example 4) Polyurethane acrylate mixed liquid (Q1): Into a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel, 533 parts by mass of pentaerythritol triacrylate (pentaerythritol triacrylate (PE-3A) manufactured by Thermo Fisher Scientific, purity 97% or more, molecular weight 298), 237 parts by mass of ARONIX M306, and 0.1 parts by mass of NEOSTANN U-810 were added, and after the liquid temperature was adjusted to 50° C., 224 parts by mass of DESMODUR I (isophorone diisocyanate (IPDI) manufactured by Sumika Covestro Corporation) was added dropwise from the dropping funnel over 30 minutes. After the heating was completed, the temperature was raised to 80°C and reacted for 3 hours. After confirming that the peak of the isocyanate group disappeared in FT-IR, the temperature was lowered to room temperature to obtain a polyurethane acrylate mixed liquid Q1 containing 82.6% by mass of a polyurethane acrylate (a2-1) having a molecular weight of 900 and 6 acryloyl groups (acryloyl equivalent 137), 9.7% by mass of pentaerythritol triacrylate (a3-1) (PE-3A, acryloyl equivalent 99) and 7.7% by mass of pentaerythritol tetraacrylate (a3-2) (PE-4A, acryloyl equivalent 88) in the non-volatile component.

[0153] (Synthesis Example 5) Urethane acrylate mixed liquid (Q2): In a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel, 2500 parts by mass of ARONIX M403 (manufactured by Toagosei Co., Ltd., a mixture of 55% by mass of dipentaerythritol pentaacrylate (DPPA (a3-3)) having a molecular weight of 524 and 45% by mass of dipentaerythritol hexaacrylate (DPHA (a3-4)) having a molecular weight of 579) and 0.1 parts by mass of NEOSTANN U-810 were added, and after the liquid temperature was adjusted to 50° C., 224 parts by mass of DESMODUR I was added dropwise from the dropping funnel over a period of 30 minutes. After the heating was completed, the temperature was raised to 80°C and reacted for 3 hours. After confirming that the peak of the isocyanate group disappeared in FT-IR, the temperature was lowered to room temperature to obtain a polyurethane acrylate mixed liquid (Q2) containing 46.7% by mass of a polyurethane acrylate (a2-2) having a molecular weight of 1300 and 10 acryloyl groups (acryloyl equivalent 127), 12.0% by mass of dipentaerythritol pentaacrylate (a3-3) (DPPA, acryloyl equivalent 105) and 41.3% by mass of dipentaerythritol hexaacrylate (a3-4) (DPHA, acryloyl equivalent 96) in the non-volatile component.

[0154] The materials used in Examples and Comparative Examples are as follows.

[0155] <Multifunctional urethane (meth)acrylate (a1)>

[0156] (a1-1): molecular weight 1600, number of acryloyl groups 9

[0157] (a1-2): molecular weight 1400, number of acryloyl groups 9

[0158] (a1-3): molecular weight 4000, number of acryloyl groups 6

[0159] <Multifunctional urethane (meth)acrylate (a2)>

[0160] (a2-1): molecular weight 900, number of acryloyl groups 6

[0161] (a2-2): molecular weight 1300, number of acryloyl groups 10

[0162] <Multifunctional (meth)acrylate (a3)>

[0163] (a3-1): Pentaerythritol triacrylate (PE-3A)

[0164] (a3-2): Pentaerythritol tetraacrylate (PE-4A)

[0165] (a3-3): Dipentaerythritol pentaacrylate (DPPA)

[0166] (a3-4): Dipentaerythritol hexaacrylate (DPHA)

[0167] · Multifunctional acrylate liquid (R1): ARONIX M-403 manufactured by Toagosei Co., Ltd. (a mixture of 55% of dipentaerythritol pentaacrylate (a3-3) and 45% of dipentaerythritol tetraacrylate (a3-4))

[0168] Multifunctional acrylate liquid (R2): SARTOMER SR368 manufactured by Arkema (molecular weight 423, number of acryloyl groups 3, (a3-5))

[0169] · Multifunctional acrylate liquid (R3): ARTRESIN UN-5507 manufactured by Negami Industries Co., Ltd. (molecular weight 17000, number of acryloyl groups 15.5, (a3-6), containing 50% of propylene glycol monomethyl ether acetate)

[0170] <Ultraviolet blocking agent (B)>

[0171] UV blocker (b-1): TINUVIN 477 manufactured by BASF (hydroxyphenyl triazine-based UV blocker, molecular weight greater than 300)

[0172] Ultraviolet light blocking agent (b-2): RUVA-93 manufactured by Otsuka Chemical Co., Ltd. (benzotriazole-based ultraviolet light blocking agent, molecular weight 323)

[0173] UV blocker (b-3): Uvinul 3050 manufactured by BASF (benzophenone-based UV blocker, molecular weight 246)

[0174] UV blocker (b-4): VANARESIN UVA-5080 manufactured by Shin-Nakamura Chemical Industry Co., Ltd. (benzotriazole-based UV blocker, molecular weight 40,000 to 60,000)

[0175] <Photopolymerization initiator (C)>

[0176] (c-1): ESACURE ONE manufactured by Agenmon Resins GmbH of the Netherlands: oligomeric [2-hydroxy-2-methyl-[1-(methylvinyl)phenyl]acetone

[0177] (c-2): DAIDO UV-CURE APO manufactured by Daido Chemical Industry Co., Ltd.: diphenyl-2,4,6-trimethylbenzoylphosphine oxide

[0178] (c-3): Irgacure OXE01 manufactured by BASF: 1-[4-(phenylthio)phenyl]octane-1,2-dione = 2-(O-benzoyl oxime)

[0179] (c-4): Irgacure OXE03 manufactured by BASF: oxime ester-based photopolymerization initiator

[0180] (c-5): Omnirad 907 manufactured by Agenmon Resins GmbH of the Netherlands: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one

[0181] <Sensitizer (F)>

[0182] (f): Omnirad DETX manufactured by Agenmon Resins GmbH of the Netherlands: 2,4-diethylthioxanthone

[0183] <Solvent (D)>

[0184] ·(d1) n-Butyl acetate (manufactured by Daicel Co., Ltd.)

[0185] (d2) DMC: dimethyl carbonate (manufactured by Ube Industries, Ltd.)

[0186] ·(d3)MEK: Methyl ethyl ketone (manufactured by Maruzen Petrochemical Co., Ltd.)

[0187] (d4) MIBK: methyl isobutyl ketone (manufactured by Mitsubishi Chemical Corporation)

[0188] (d5) PGM: Propylene glycol monomethyl ether (manufactured by Daishin Chemical Co., Ltd.)

[0189] <Transparent substrate>

[0190] PET: Polyethylene terephthalate resin film with a thickness of 50 μm

[0191] PMMA: Polymethyl methacrylate resin film with a thickness of 50 μm

[0192] PC: Polycarbonate resin film with a thickness of 50 μm

[0193] ·COP: Polycycloolefin resin film with a thickness of 50 μm

[0194] <Example 1>

[0195] In a flask with a stirrer, 20.9 parts of a polyurethane acrylate liquid (P1), 67.8 parts of a polyurethane acrylate liquid (Q1), 14.4 parts of a multifunctional acrylate liquid (R1), 10 parts of an ultraviolet shielding agent TINUVIN477 (b-1), 10.0 parts of a photopolymerization initiator Irgacure OXE03 (c-4), 35 parts of dimethyl carbonate (d2), 12.2 parts of methyl ethyl ketone (d3), 40 parts of methyl isobutyl ketone (d4) and 10 parts of propylene glycol monomethyl ether (d5) were added and stirred and mixed to obtain a hard coat layer-forming composition containing the following compounds.

[0196] Polyurethane acrylate (a1-1): 14.0 parts

[0197] Polyurethane acrylate (a2-1): 56.0 parts

[0198] Pentaerythritol triacrylate (a3-1): 6.6 parts

[0199] Pentaerythritol tetraacrylate (a3-2): 9.2 parts

[0200] Dipentaerythritol pentaacrylate (a3-3): 7.8 parts

[0201] Dipentaerythritol hexaacrylate (a3-4): 6.4 parts

[0202] The total amount of the active energy ray curing component (A) is 100 parts

[0203] Other compounds (e-1): 0.6 parts

[0204] UV blocker TINUVIN477 (b-1): 10 parts

[0205] Photopolymerization initiator Irgacure OXE03 (c-4): 10 parts

[0206] n-Butyl acetate (d1): 2.8 parts

[0207] Dimethyl carbonate (d2): 35.0 parts

[0208] Methyl ethyl ketone (d3): 12.2 parts

[0209] Methyl isobutyl ketone (d4): 40.0 parts

[0210] Propylene glycol monomethyl ether (d5): 10.0 parts

[0211] <Examples 2 to 37, Comparative Examples 1 to 6>

[0212] Hard coat layer-forming compositions of Examples 2 to 37 and Comparative Examples 1 to 6 were prepared in the same manner as in Example 1 except that the compositions, blending amounts (parts by mass) and transparent substrates were changed as shown in Tables 1 to 4.

[0213] The obtained hard coat layer-forming composition was used to evaluate dissolution resistance, pencil hardness, adhesion, and warpage by the following methods. The results are shown in Tables 1 to 4.

[0214] [Dissolution resistance]

[0215] The hard coat layer-forming composition obtained was applied onto a transparent substrate using a bar coater No. 8 and irradiated with a high-pressure mercury lamp having an output of 80 W / cm2 to a cumulative exposure of 400 mJ / cm2. 2 The coating layer was cured by ultraviolet light to obtain a hard coating film for evaluating dissolution resistance having a hard coating layer with a film thickness of 5 to 6 μm. The obtained hard coating film was cut into a test film with a length of 100 mm and a width of 50 mm as a test film. The test film was immersed in a 9 wt % sodium hydroxide aqueous solution heated to 50°C for 5 minutes, and the taken out test film was washed with water and dried in a box oven at 100°C for 2 minutes.

[0216] The transmittances (ta) and (tc) shown below were measured.

[0217] (ta): transmittance at a wavelength of 380 nm of the hard coating film not immersed in the sodium hydroxide aqueous solution.

[0218] (tc): Transmittance at a wavelength of 380 nm of the hard coating film after being immersed in a sodium hydroxide aqueous solution, washed with water and dried.

[0219] (tc)-(ta) was calculated from the obtained (ta) and (tc), and the dissolution resistance was evaluated according to the following criteria. In addition, the dissolution resistance of Comparative Example 4 in which no UV shielding agent was added could not be evaluated, and was recorded as "-".

[0220] ○: (tc)-(ta)≤1% (good)

[0221] △: 1%<(tc)-(ta)≤2% (no problem in practice)

[0222] ×: 2%<(tc)-(ta) (not practical)

[0223] [Pencil hardness]

[0224] A hard coating film for pencil hardness evaluation was obtained in the same manner as in [Dissolution resistance]. The pencil hardness of the obtained hard coating film was measured using pencils of different hardnesses by a test method in accordance with JIS K5400 (1990).

[0225] ◎: Pencil hardness 3H or above (excellent)

[0226] ○: Pencil hardness is H to 2H (good)

[0227] △: Pencil hardness is F (no problem in practical use)

[0228] ×: Pencil hardness is HB or less (not practical)

[0229] [Adhesion]

[0230] A hard coating film for adhesion evaluation was obtained in the same manner as in [Dissolution Resistance]. The surface of the obtained hard coating film opposite to the hard coating layer was attached to a glass plate via an adhesive layer having a thickness of about 20 μm, and then the hard coating surface was subjected to a cross-cut peeling test according to JIS K5400 and evaluated using the following indexes.

[0231] ◎: Number of peeled pieces 0 / 100 (excellent)

[0232] ○: Number of peeled pieces: 1 to 5 / 100 (good)

[0233] △: Number of peelings: 6 to 20 / 100 (no problem in practice)

[0234] ×: Number of peelings: 21 to 100 / 100 (not practical)

[0235] [Warp test]

[0236] A hard coating film for a warpage test was obtained in the same manner as in [Dissolution Resistance].

[0237] The obtained hard coating film was cut into a test film having a length of 100 mm and a width of 50 mm, and was left in a constant temperature and humidity chamber at 22° C. and 50% RH for 6 hours.

[0238] The test film was placed on a horizontal surface, and the distances between the two ends in the width direction were measured at three locations, namely, the two ends and the center of the long side, using a micrometer, and the average value was calculated.

[0239] ◎: 40mm or more (excellent)

[0240] ○: 30 mm or more and less than 40 mm (good)

[0241] △: 10mm or more and less than 30mm (no problem in practical use)

[0242] ×: cylindrical, or less than 10 mm (not practical)

[0243] [Table 1]

[0245] [Table 2]

[0247] [Table 3]

[0249] [Table 4]

[0251] As shown in Tables 1 to 4, by using the hard coat-forming composition of the present invention, a hard coat film having a hard coat layer can be provided, wherein the hard coat layer has high ultraviolet shielding properties, reduces the dissolution of the ultraviolet shielding agent in the saponification process, prevents the reduction of the ultraviolet shielding properties of the coating film and the contamination of the saponification treatment liquid, improves the efficiency of the display production process due to low curling properties, and has scratch resistance in the display production process due to the impartment of high hard coating properties.

Claims

1. An active energy ray-curable composition for forming a hard coating layer on a transparent substrate, The active energy ray-curable composition comprises an active energy ray-curable component (A), an ultraviolet shielding agent (B), a photopolymerization initiator (C) and a solvent (D). The active energy ray-curable component (A) contains all of the following (a1), (a2) and (a3): (a1) a polyfunctional urethane (meth)acrylate having 6 or more (meth)acryloyl groups and a urate ring skeleton; (a2) a multifunctional polyurethane (meth)acrylate having 4 to 15 (meth)acryloyl groups and a weight average molecular weight of 500 to 15,000 (excluding (a1)); (a3) other multifunctional (meth)acrylates, The mass ratio (a1) / (a2) of (a1) to (a2) contained in the active energy ray-curable component (A) is 50 / 50 to 70 / 30, The molecular weight of the ultraviolet blocking agent (B) is 300 or more, The photopolymerization initiator (C) includes at least one of an oxime ester compound and a phosphine oxide compound. 2 . A hard coating film comprising a hard coating layer which is a cured product of the active energy ray-curable composition according to claim 1 on a transparent substrate.

3. The hard coating film according to claim 2, wherein: The hard coating film has a transmittance (ta) of 4% or less at a wavelength of 380 nm and a transmittance (tb) of 70% or more at a wavelength of 420 nm.

4. The hard coating film according to claim 3, wherein The hard coating film satisfies the following formula (2): Formula (2) (tc)-(ta)≤1% (ta): transmittance of the hard coating film not immersed in the sodium hydroxide aqueous solution at a wavelength of 380 nm, (tc): Transmittance at a wavelength of 380 nm of the hard coating film after being immersed in a sodium hydroxide aqueous solution, washed with water and dried. 5 . A laminate comprising the hard coating film according to claim 2 and a circularly polarizing functional layer.

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