Optical films, polarizing plates, liquid crystal panels, touch panels, and image display devices

Abstract

The present invention provides an optical film that functions as a glass substitute and has excellent impact absorption properties, as well as a polarizer, liquid crystal panel, touch panel, and image display device having the optical film. The present invention provides an optical film, a polarizer, liquid crystal panel, touch panel, and image display device having the optical film, wherein the optical film comprises a resin film and an impact absorption layer disposed on at least one surface of the resin film, wherein the impact absorption layer has a high shock absorption capacity at 25°C and a frequency of 10 6 The storage modulus E' at Hz is 1 GPa or less.

Description

[0001] This application is a divisional application of Chinese patent application 201980028545.4 filed on October 27, 2020 (international application number PCT / JP2019 / 020209, invention name: optical film, polarizer, liquid crystal panel, touch panel and image display device). Technical Field

[0002] The present invention relates to an optical film, a polarizing plate, a liquid crystal panel, a touch panel and an image display device. Background Art

[0003] Chemically strengthened glass and other glass have been the primary materials used for optical films requiring high durability, such as the front panels of image display devices, especially touch panel displays. In recent years, the various functionalities of resin films, such as lightness, toughness (crack resistance), and film processability (thinning capability), have attracted attention. The use of resin films as glass alternatives is expected to enhance the functionality of optical films.

[0004] As a resin film of a glass substitute material, for example, Patent Document 1 describes a resin laminate having a resin plate provided on one surface of a transparent substrate having in-plane birefringence, wherein the transparent substrate having in-plane birefringence has a retardation of 8000 nm or more.

[0005] Previous technical literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-129868 Summary of the Invention

[0008] Technical issues to be solved by the invention

[0009] When the resin laminate is used as a front panel for a touch panel, a front panel for a touch panel display, or an optical film such as a protective film for a polarizer, external impact on the front panel may damage internal materials of the display such as a liquid crystal cell, thereby impairing its function.

[0010] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an optical film that functions as a glass substitute and has excellent impact absorption properties, and a polarizing plate, a liquid crystal panel, a touch panel, and an image display device having the optical film.

[0011] Means for solving technical problems

[0012] The above-mentioned problems were solved by the following means. (1)

[0014] An optical film comprising a resin film and a shock absorbing layer disposed on at least one surface of the resin film, wherein the shock absorbing layer is 6 The storage modulus E' at Hz is 1 GPa or less. (2)

[0016] The optical film according to (1), wherein

[0017] The impact absorbing layer has a thickness of 10 μm to 80 μm. (3)

[0019] The optical film according to (1) or (2), wherein

[0020] The resin film has a hard coating layer on a surface opposite to the surface on which the impact absorbing layer is arranged. (4)

[0022] A polarizing plate comprising the optical film described in (1) or (2). (5)

[0024] A polarizing plate comprising the optical film described in (3). (6)

[0026] A liquid crystal panel having the polarizing plate described in (4) as a rear polarizing plate. (7)

[0028] A liquid crystal panel having the polarizing plate described in (5) as a front polarizing plate. (8)

[0030] A liquid crystal panel having the polarizing plate described in (4) as a rear polarizing plate and the polarizing plate described in (5) as a front polarizing plate. (9)

[0032] The liquid crystal panel according to (8), wherein

[0033] The storage modulus E' of the impact absorbing layer of the optical film of the rear polarizer r The storage modulus E'f of the impact absorbing layer of the optical film of the front polarizing plate satisfies the following formula.

[0034] E'f-E'r≥0 (10)

[0036] The liquid crystal panel according to any one of (6) to (9), comprising a touch sensor. (11)

[0038] A touch panel is formed by laminating the optical film according to any one of (1) to (3) to a touch sensor film. (12)

[0040] The liquid crystal panel according to any one of (6) to (9), comprising the touch panel according to (11). (13)

[0042] An image display device having the liquid crystal panel described in any one of (6) to (10) and (12).

[0043] The “front side” and “rear side” indicate the relative positional relationship of the polarizers when assembled into a liquid crystal display device. That is, the “front side polarizer” refers to the polarizer located on the visual recognition side when the liquid crystal panel is assembled into the liquid crystal display device, among the liquid crystal cell and the two polarizers holding the liquid crystal cell, and the “rear side polarizer” refers to the polarizer located on the side opposite to the visual recognition side (visual recognition opposite side) when the liquid crystal panel is assembled into the liquid crystal display device. For example, in a liquid crystal display device with a direct backlight, the visual recognition opposite side refers to the side where the backlight is present when assembled into the liquid crystal display device, and is located on the side opposite to the visual recognition side across the liquid crystal cell.

[0044] In this specification, when there are multiple substituents, linking groups, repeating structures, etc. (hereinafter referred to as substituents, etc.) represented by specific symbols, or when multiple substituents, etc. are specified at the same time, unless otherwise specified, each substituent, etc. may be the same or different from each other. This is also the same as the number of substituents, etc. regulations. In addition, when multiple substituents, etc. are close (especially, adjacent), unless otherwise specified, they can be linked to each other to form a ring. In addition, rings such as aliphatic rings, aromatic rings, and heterocyclic rings can be further fused to form a fused ring.

[0045] In this specification, when the number of carbon atoms in a group is specified, the number of carbon atoms refers to the total number of carbon atoms in the group. That is, when the group further has a substituent, the number of carbon atoms in the group including the substituent is specified.

[0046] In this specification, the numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0047] In this specification, "(meth)acrylate" is used to mean either or both of acrylate and methacrylate. Furthermore, "(meth)acryloyl" is used to mean either or both of acryloyl and methacryloyl. "(Meth)acrylic acid" is used to mean either or both of acrylic acid and methacrylic acid.

[0048] In this specification, the term "(co)polymer" is used to mean either or both of a homopolymer and a copolymer.

[0049] Each component described in this specification may be used alone or in combination of two or more components having different structures. Furthermore, when two or more components having different structures are used in combination, the content of each component refers to the total content thereof.

[0050] In this specification, the solid content in the impact absorbing layer and the solid content in the hard coating layer refer to the components remaining in the layer when the layer is formed by coating and drying a composition containing a solvent, that is, the components other than the solvent.

[0051] In this specification, unless otherwise specified, the weight average molecular weight (Mw) can be measured by GPC as a molecular weight equivalent to polystyrene. At this time, a GPC apparatus HLC-8220 (manufactured by TOSOH CORPORATION) was used, a G3000HXL + G2000HXL column was used, a flow rate of 1 mL / min at 23°C, and detection was performed using RI. As an eluent, THF (tetrahydrofuran), chloroform, NMP (N-methyl-2-pyrrolidone), and m-cresol / chloroform (manufactured by Shonan Wako Pure Chemical Industries Co., Ltd.) can be selected. If the material is dissolved, THF is used.

[0052] In this specification, the thickness of each layer and the storage modulus in the tensile deformation mode are measured by the method described in the Examples.

[0053] The optical film of the present invention can be used as a front plate for a touch panel or a touch panel display (an image display device with a touch sensor function), or as a protective film for a polarizer (also called a polarizer protective film), thereby effectively preventing damage to materials within a display such as a liquid crystal cell. Furthermore, the optical film of the present invention can also be preferably used as a polarizing film, a retardation film, or a brightness enhancement film for a liquid crystal display.

[0054] Effects of the Invention

[0055] The optical film of the present invention functions as a glass substitute and has excellent impact absorption properties, making it suitable for use as front plates for touch panels and touch panel displays, as well as polarizer protective films. Furthermore, polarizers, liquid crystal panels, touch panels, and image display devices of the present invention, incorporating the optical film of the present invention, can exhibit excellent impact absorption properties.

[0056] The above and other features and advantages of the present invention will become more apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is a longitudinal sectional view showing one embodiment of the structure of the optical film of the present invention.

[0058] Figure 2 This is a longitudinal sectional view showing one embodiment of the structure of the optical film of the present invention having a hard coat layer.

[0059] Figure 3 This is a longitudinal sectional view schematically showing the pseudo liquid crystal panel used in Test Example 1 including the base. DETAILED DESCRIPTION

[0060] Preferred embodiments of the optical film of the present invention will be described.

[0061] <<Optical Film>>

[0062] Figure 1 Preferred embodiments of the optical film of the present invention will be described. Figure 1 The optical film 4A shown is an optical film comprising a resin film 1A and a shock absorbing layer 2A disposed on one side of the resin film 1A. As will be described later, the shock absorbing layer is subjected to a shock absorbing effect at 25°C and a frequency of 10 6 Hz(1.0×10 6 The storage modulus E' at 100 Hz represents a value within a specific range. The optical film of the present invention has the above-mentioned structure and achieves excellent impact absorption. For example, when used as a front plate of a touch panel or a front plate of a touch panel display, or as a polarizer protective film, it can prevent damage to the internal materials of the display and maintain its function even when subjected to external impact.

[0063] The resin film and the impact absorbing layer may be a single layer or a multilayer layer.

[0064] (Film thickness of optical film)

[0065] From the viewpoint of impact absorption, the thickness of the optical film of the present invention is preferably 20 μm or more, more preferably 40 μm or more. In practice, the upper limit is 200 μm or less.

[0066] (Delay in the in-plane direction)

[0067] From the viewpoint of reducing interference unevenness, the retardation in the in-plane direction of the optical film at a wavelength of 550 nm is preferably less than 6000 nm, i.e., less than 6000 nm, more preferably 1000 nm or less, further preferably 500 nm or less, and even more preferably 50 nm or less.

[0068] Among them, when linearly polarized light is incident on the optical film and the light passing through the optical film is decomposed into two linearly polarized lights along the fast axis and the slow axis, the phase difference (delay) in the in-plane direction of the optical film is defined as R (unit: nm) represented by the following formula (A) by the refractive index Nx on the fast axis and the refractive index Ny on the slow axis and the thickness d (unit: nm) of the optical film.

[0069] R=d×(Nx-Ny) (A)

[0070] In this specification, in-plane retardation at a wavelength of 550 nm is measured using a KOBRA21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) by directing light of 550 nm into the normal direction of the film or layer being measured. The measurement wavelength can be selected by manually changing the wavelength selection filter or converting the measured value using a program. Alternatively, in-plane retardation can be measured using an AxoScan (manufactured by AXOMETRICS).

[0071] Hereinafter, the components and preparation of the thin films and layers constituting the optical film of the present invention will be described in detail.

[0072] (1) Resin film

[0073] (Material of resin film)

[0074] The material of the resin film used in the present invention is not particularly limited.

[0075] Examples of the resin film include acrylic resin films, polycarbonate (PC) resin films, cellulose ester resin films such as triacetylcellulose (TAC) resin films, polyethylene terephthalate (PET) resin films, polyolefin resin films, polyester resin films, polyimide resin films, polyamide resin films, polyamideimide resin films, and acrylonitrile-butadiene-styrene copolymer resin films. The resin film is preferably one of acrylic resin films, cellulose ester resin films, polyethylene terephthalate resin films, and polycarbonate resin films. From the viewpoint of moisture permeability, a cellulose ester resin film is more preferred, and a cellulose acetate resin film is even more preferred.

[0076] The acrylic resin film refers to a polymer or copolymer resin film formed from at least one compound selected from acrylate and methacrylate. Examples of the acrylic resin film include polymethyl methacrylate (PMMA) films.

[0077] From the viewpoint of increasing the tensile modulus, the weight average molecular weight of the resin is preferably 10,000 to 1,000,000, more preferably 100,000 to 1,000,000.

[0078] (Structure of Resin Film)

[0079] Furthermore, the structure of the resin film is not limited and may be a single layer or a laminated film composed of two or more layers, preferably a laminated film composed of two or more layers. The number of layers of the laminated film is preferably 2 to 10, more preferably 2 to 5, and even more preferably 2 or 3. In the case of three or more layers, the outer layer and the layers other than the outer layer (core layer, etc.) are preferably films of different compositions. Furthermore, the outer layers are preferably films of the same composition.

[0080] Specific examples include films having a laminated structure of TAC-a / TAC-b / TAC-a, acrylic-a / PC / acrylic-a, and PFT-a / PET-b / PET-a, as well as films of a single polycarbonate resin layer. Films labeled with the same reference numeral (a or b) (e.g., TAC-a films) have the same composition.

[0081] (additive)

[0082] The resin film may contain additives in addition to the above-mentioned resin (material). Examples of the additives include inorganic particles, matte particles, ultraviolet absorbers, fluorine-containing compounds, surface conditioners, and leveling agents described below for the hard coat layer.

[0083] In the melt film forming method described later, it can be used as a resin melt obtained by mixing and melting the above additives and resin, and in the solution film forming method described later, it can be used as a dope obtained by mixing a solvent (which can be applied to the description of the hard coat described later), resin and the above additives to form a resin film.

[0084] (Tensile elastic modulus)

[0085] The tensile modulus of a resin film can vary depending on the type of resin comprising the film. Generally, increasing at least one of the molecular weight and crystallinity of the resin tends to increase the tensile modulus. Furthermore, the tensile modulus of a resin film in the tensile direction can be increased by stretching. Even when the resin film is composed of multiple layers, the tensile modulus of the resin film as a whole is indicated.

[0086] The tensile modulus of the resin film at 25°C is preferably 2.0 GPa or higher, more preferably 2.5 GPa or higher, further preferably 3.0 GPa or higher, particularly preferably 3.5 GPa or higher, and most preferably 4.0 GPa or higher. The upper limit is not particularly limited, but is practically 12.0 GPa or lower.

[0087] The "tensile modulus" of the resin film can be calculated by testing according to the method described in JIS K7127 by the following method.

[0088] A 15 cm long and 1 cm wide resin film was cut out in the measurement direction to serve as a measurement sample. The cut sample was placed on a tensile testing machine (manufactured by TOYOSEIKI Co., Ltd., product name: "Strograph-R2") with a chuck spacing of 10 cm in the measurement direction. At a measurement temperature of 25°C, the sample was stretched at a rate of 10 mm / min, increasing the chuck spacing, to obtain a stress-strain curve. The tensile modulus at 25°C was calculated by linear regression of the curve between two predetermined strains, ε1 = 0.0005 and ε2 = 0.0025.

[0089] In addition, when the resin film has anisotropy, the average value of the tensile elastic modulus of the measurement sample with the orientation direction with the largest orientation degree as the long side and the tensile elastic modulus of the measurement sample with the direction orthogonal to the orientation direction as the long side on the surface perpendicular to the thickness direction of the resin film is taken as the tensile elastic modulus of the resin film.

[0090] (film thickness)

[0091] From the perspective of impact absorption, the film thickness of the resin film is preferably 80 μm or more, more preferably 100 μm or more. The upper limit is not particularly limited, but is preferably 190 μm or less. In addition, when the resin film is a laminated film of more than two layers as described above, the film thickness of the resin film represents the film thickness of the laminated film.

[0092] The thickness of the resin film hardly changes before and after the production of the optical film of the present invention.

[0093] (easy bonding layer)

[0094] The resin film used in the present invention may also include an easy-adhesion layer. Regarding the easy-adhesion layer, the contents of the polarizer-side easy-adhesion layer and the method for producing the polarizer-side easy-adhesion layer described in paragraphs 0098 to 0133 of JP-A-2015-224267 can be incorporated into this specification together with the present invention.

[0095] In this case, the easily adhesive layer is a layer constituting the resin film in the optical film of the present invention.

[0096] (Resin Film Formation Method)

[0097] The resin film can be formed by any method, and examples thereof include a melt film forming method and a solution film forming method.

[0098] <Melt Film Forming, Smoothing>

[0099] When producing a resin film using a melt film forming method, the process preferably includes a step of melting the resin using an extruder, extruding the molten resin from a die into a sheet, and forming the resin into a film. Depending on the resin material, the molten resin may be filtered after the melting step, or cooled during extrusion into a sheet.

[0100] Hereinafter, a specific melt film forming method will be described, but the present invention is not limited thereto.

[0101] [Method for Forming Resin Film]

[0102] The manufacturing method of the above-mentioned resin film includes: a melting process, using an extruder to melt the resin; a filtering process, filtering the molten resin through a filtering device equipped with a filter; a film forming process, by extruding the filtered resin from a mold into a sheet, making it adhere to a cooling drum and cooling and solidifying it to form an unstretched resin film; and a stretching process, stretching the unstretched resin film in one axis or two axes.

[0103] This structure enables the production of a resin film. If the pore size of the filter used in the filtration step of the molten resin is 1 μm or less, foreign matter can be sufficiently removed. Consequently, the surface roughness of the resulting resin film in the film width direction can be controlled.

[0104] Specifically, the method for forming the resin film can include the following steps.

[0105] <Melting Process>

[0106] The method for producing the resin film includes a melting step of melting the resin using an extruder.

[0107] The resin or the mixture of the resin and the additive is preferably dried to a moisture content of 200 ppm or less and then introduced into a single-axis (uniaxial) or double-axis extruder to be melted. In order to suppress the decomposition of the resin, it is also preferred to melt in nitrogen or in a vacuum. The detailed conditions can be adopted from Patent No. 4962661. <0051> ~ <0052> (US2013 / 0100378 publication <0085> ~ <0086> ), implemented in accordance with these gazettes, and the contents recorded in these gazettes are incorporated into this manual.

[0108] The extruder is preferably a single-screw kneading extruder.

[0109] Furthermore, in order to improve the delivery accuracy of the molten resin (melt), it is also preferable to use a gear pump.

[0110] <Filtration process>

[0111] The method for producing the resin film includes a filtration step of filtering the molten resin through a filtration device equipped with a filter. The pore size of the filter used in the filtration step is preferably 1 μm or less.

[0112] The filtration device having filters within such a pore size range may be provided in a single set or in two or more sets in the filtration step.

[0113] <Film Forming Process>

[0114] The method for producing the resin film includes a film forming step of extruding the filtered resin from a die into a sheet, adhering the sheet to a cooling drum, and cooling and solidifying the sheet to form an unstretched resin film.

[0115] When the melted (and kneaded) and filtered resin (including the resin melt) is extruded from a die into a sheet, it can be extruded in a single layer or in multiple layers. In the case of multi-layer extrusion, for example, a layer containing a UV absorber and a layer not containing a UV absorber can be stacked. From the perspective of suppressing degradation of the polarizer caused by ultraviolet rays and suppressing the leakage of the UV absorber, a three-layer structure in which the layer containing the UV absorber is the inner layer is preferred.

[0116] When a resin film is produced by multi-layer extrusion, the thickness of the inner layer of the obtained resin film is preferably 50% to 99% of the thickness of all layers, more preferably 60% to 99%, and even more preferably 70% to 99%. This lamination can be performed using a feedblock die, a multi-manifold die, or the like.

[0117] Preferably, the method according to Japanese Patent Application Laid-Open No. 2009-269301 is used. <0059> The resin (including the resin melt) extruded from the die into a sheet shape is extruded onto a cooling drum (casting drum), cooled and solidified to obtain an unstretched resin film (roll film).

[0118] In the above-described method for producing a resin film, the temperature of the resin extruded from the die is preferably 280°C to 320°C, more preferably 285°C to 310°C. To reduce molten residue in the raw resin and thereby suppress the generation of foreign matter, the temperature of the resin extruded from the die during the melting step is preferably 280°C or higher. To reduce resin decomposition and thereby suppress the generation of foreign matter, the temperature of the resin extruded from the die during the melting step is preferably 320°C or lower.

[0119] The temperature of the resin extruded from the die can be measured with a radiation thermometer (manufactured by Hayashi Denko Co., Ltd., model: RT61-2, used with an emissivity of 0.95) without contacting the surface of the resin.

[0120] In the above-mentioned method for producing a resin film, it is preferred that an electrostatic application electrode be used when adhering the resin to the cooling drum in the film forming step, thereby making it possible to firmly adhere the resin to the cooling drum without roughening the film surface.

[0121] In the above-mentioned method for producing a resin film, the temperature of the resin when adhering to the cooling drum (the point where the molten resin extruded from the die first contacts the cooling drum) is preferably 280°C or higher. This improves the conductivity of the resin, allows the resin to be firmly adhered to the cooling drum by electrostatic application, and suppresses roughening of the film surface.

[0122] The temperature of the resin when adhering to the cooling drum can be measured with a radiation thermometer (manufactured by Hayashi Denko Co., Ltd., model: RT61-2, used with an emissivity of 0.95) without contacting the surface of the resin.

[0123] <Stretching process>

[0124] The method for producing the resin film includes a stretching step of uniaxially or biaxially stretching an unstretched resin film.

[0125] In the longitudinal stretching step (a step of stretching in the same direction as the film conveying direction), after the resin film is preheated, the heated resin film is stretched in the conveying direction using a roller group having a circumferential speed difference (i.e., different conveying speeds).

[0126] The preheating temperature in the longitudinal stretching step is preferably from Tg - 40°C to Tg + 60°C, more preferably from Tg - 20°C to Tg + 40°C, and even more preferably from Tg to Tg + 30°C, relative to the glass transition temperature (Tg) of the resin film. Furthermore, the stretching temperature in the longitudinal stretching step is preferably from Tg to Tg + 60°C, more preferably from Tg + 2°C to Tg + 40°C, and even more preferably from Tg + 5°C to Tg + 30°C. The stretch ratio in the longitudinal direction is preferably from 1.0 times to 2.5 times, and even more preferably from 1.1 times to 2 times.

[0127] In addition to or in place of the longitudinal stretching step, the resin film can be stretched transversely in the width direction by a transverse stretching step (a step of stretching in a direction perpendicular to the film's conveyance direction). In the transverse stretching step, for example, a tenter can be preferably used, whereby the resin film is gripped at both widthwise ends with clamps and stretched in the transverse direction. This transverse stretching can increase the tensile modulus of the resin film in the optical film.

[0128] Transverse stretching is preferably performed using a tenter. The preferred stretching temperature relative to the glass transition temperature (Tg) of the resin film is preferably Tg or higher and Tg+60°C or lower, more preferably Tg+2°C or higher and Tg+40°C or lower, and even more preferably Tg+4°C or higher and Tg+30°C or lower. The stretch ratio is preferably 1.0 times or higher and 5.0 times or lower, and even more preferably 1.1 times or higher and 4.0 times or lower. It is also preferred to relax the resin film in either or both the longitudinal and transverse directions after transverse stretching.

[0129] Furthermore, the variation in thickness due to position in both the width direction and the length direction is preferably set to 10% or less, more preferably 8% or less, further preferably 6% or less, particularly preferably 4% or less, and most preferably 2% or less.

[0130] Note that the variation in thickness can be obtained as follows.

[0131] A 10-meter section of the stretched resin film was sampled, and 20% of both ends in the film width direction were removed. 50 points were sampled at equal intervals in the width direction and the length direction from the center of the film to measure the thickness.

[0132] Calculate the average thickness Th in the width direction TD-av , maximum value Th TD-max and minimum value Th TD-min ,

[0133] (Th TD-max -Th TD-min )÷Th TD-av ×100[%]

[0134] is the variation in thickness in the width direction.

[0135] Then, the average value Th of the thickness in the longitudinal direction is obtained. MD-av , maximum value Th MD-max and minimum value Th MD-min ,

[0136] (Th MD-max -Th MD-min )÷Th MD-av ×100[%]

[0137] is the variation in thickness in the length direction.

[0138] The above-mentioned stretching step can improve the thickness accuracy of the resin film.

[0139] The stretched resin film can be wound into a roll in the winding process. At this time, the winding tension of the resin film is preferably set to 0.02 kg / mm 2 the following.

[0140] Regarding other detailed conditions, melt film forming can be carried out by combining the <0134> ~ <0148> The contents described in the stretching step and the contents described in Japanese Patent Application Laid-Open No. 2007-137028 can be incorporated into this specification together with the present invention.

[0141] <Solution Film Formation, Smoothing>

[0142] When a resin film is produced by a solution film forming method, the process preferably includes the steps of casting a dope solution onto a casting belt to form a cast film, drying the cast film, and stretching the cast film. Specifically, the film is preferably formed by the method described in Japanese Patent No. 4889335.

[0143] In the present invention, the following method is preferably employed.

[0144] For example, the method of slowly drying the cast film by setting the drying speed of the cast film to 300 mass % / minute (=5 mass % / s) or less based on the amount of solvent contained in the drying amount benchmark as described in Japanese Patent Laid-Open No. 11-123732 Gazette can be cited. In addition, in the co-casting method of the cast film having a multilayer structure with a surface layer (outer layer) on both surfaces of the core layer as the intermediate layer as described in Japanese Patent Laid-Open No. 2003-276037 Gazette, the method of improving the viscosity of the doping solution forming the core layer to ensure the strength of the cast film and reducing the viscosity of the doping solution forming the outer layer can be cited. In addition, the cast film can also be preferably dried quickly to form a film on the cast film surface, and the method of smoothing the surface by the leveling effect of the formed film and the method of stretching the cast film can be cited.

[0145] The structure of the resin film used in the present invention is not particularly limited as long as the effects of the present invention are exhibited. For example, when the film thickness is set to a specific value or above, the resin film may be composed of a single resin film as described above, or may be composed of a resin film formed by laminating two resin films via an adhesive layer, with the first resin film / adhesive layer / second resin film being laminated in this order.

[0146] Hereinafter, a resin film obtained by bonding two resin films together via an adhesive layer will be described.

[0147] (A resin film formed by bonding two resin films together via an adhesive layer)

[0148] From the viewpoint of preventing the optical film from being bent, the two resin films bonded together via the adhesive layer are preferably the same film.

[0149] Here, "same film" means that the resin constituting the resin film is made of the same material (for example, both are TAC films). Preferably, the resin has the same molecular weight, more preferably the same molecular weight and crystallinity, and even more preferably the same molecular weight, crystallinity, and elongation. Furthermore, in addition to the above, it is also more preferable that the two resin films have the same thickness.

[0150] Furthermore, “same” is not limited to being completely identical, but includes being substantially the same. Specifically, it means being produced using the same manufacturing method (with the same film thickness, stretching, etc.) and includes errors that occur under these conditions.

[0151] Specifically, the difference in tensile elastic modulus between the two resin films bonded together via the adhesive layer is preferably small, specifically, preferably 4.0 GPa or less, more preferably 3.0 GPa or less, further preferably 2.0 GPa or less, and particularly preferably 1.0 GPa or less.

[0152] (Thickness of resin film)

[0153] From the viewpoint of production suitability, the thickness of each of the two resin films is preferably 40 to 160 μm, more preferably 50 to 160 μm, further preferably 80 to 160 μm, and particularly preferably 100 to 160 μm.

[0154] (Adhesive layer)

[0155] The adhesive layer is a layer that plays a role in bonding the resin films together, and is not particularly limited as long as it has a function of bonding two resin films together.

[0156] The adhesive layer is preferably formed using a composition containing a component (adhesive) that exhibits adhesive properties by at least one of drying and reaction. For example, an adhesive layer formed using a composition containing a component that exhibits adhesive properties by a curing reaction (hereinafter referred to as a "curable composition") is a cured layer formed by curing the curable composition.

[0157] As the adhesive, a resin can be used. In one embodiment, the adhesive layer can be a layer in which the resin accounts for 50% or more by mass, preferably 70% or more by mass. As the resin, a single resin can be used, or a mixture of multiple resins can be used. When a mixture of resins is used, the proportion of the above-mentioned resins refers to the proportion of the resin mixture. As examples of the resin mixture, there can be cited a mixture of a certain resin and a resin having a structure in which a portion of the resin is modified, and a mixture of a resin obtained by reacting a polymerizable compound different from the polymerizable compound constituting the certain resin.

[0158] As the adhesive, any adhesive having any appropriate properties, form and bonding mechanism can be used. As specific examples, water-soluble adhesives, ultraviolet curing adhesives, latex adhesives, latex adhesives, mastic adhesives, multilayer adhesives, paste adhesives, foaming adhesives, coating film adhesives, thermoplastic adhesives, hot melt adhesives (hot melts), heat curing adhesives, heat activated adhesives, heat seal adhesives, heat curing adhesives, contact adhesives, pressure sensitive adhesives, polymerized adhesives, solvent adhesives and solvent activated adhesives can be cited. Water-soluble adhesives and ultraviolet curing adhesives are preferred. Among them, water-soluble adhesives are preferably used from the perspectives of transparency, adhesion, operability, product quality and economic efficiency.

[0159] Water-soluble adhesives can contain natural or synthetic water-soluble ingredients such as proteins, starches, and synthetic resins. Examples of synthetic resins include resol resins, urea resins, melamine resins, polyethylene oxide resins, polyacrylamide resins, polyvinyl pyrrolidone resins, polyacrylate resins, polymethacrylate resins, polyvinyl alcohol resins, polyacrylic acid resins, and cellulose derivatives. Among these, water-soluble adhesives containing polyvinyl alcohol resins or cellulose derivatives are preferred due to their excellent adhesion when laminating resin films. Specifically, the adhesive layer preferably contains polyvinyl alcohol resins or cellulose derivatives.

[0160] Here, the cellulose derivative refers to a substance obtained by modifying cellulose. The cellulose derivative is not particularly limited, and a known cellulose derivative can be used. For example, HEC (hydroxyethyl cellulose) can be used.

[0161] From the viewpoint of increasing the tensile modulus, the weight average molecular weight of the resin is preferably 1,000 or more, more preferably 10,000 or more. The upper limit is not particularly limited, but is practically 1,000,000 or less.

[0162] Examples of components optionally contained in the adhesive-containing composition include crosslinking agents (boric acid and Safelink SPM-01 (product name, manufactured by The Nippon Synthetic ChemicaI Industry Co., Ltd.)) and durability improvers (potassium iodide).

[0163] (Tensile elastic modulus)

[0164] The tensile modulus of bonding layer can for example change according to the kind of the resin constituting bonding layer, and usually by improving at least any one in the molecular weight and the crystallinity of resin, tensile modulus has the tendency of improving.And, when bonding layer has crosslinking group, can improve the crosslinking degree of bonding layer by adding crosslinking agent etc., thereby improve tensile modulus.And, when bonding layer contains polymerizable compound, by reducing the polymerizable group equivalent (the molecular weight of this compound divided by the value obtained by the sum of the polymerizable groups contained in this compound) of the compound with polymerizable group, improve the polymerization rate of bonding layer, add high elasticity material (for example inorganic particles etc.) and add the compound containing rigid molecular structure (for example adamantane skeleton) etc. to bonding layer, have the tendency of improving.

[0165] The tensile modulus of elasticity of the adhesive layer at 25°C is preferably 2.0 GPa or greater, more preferably 2.5 GPa or greater, even more preferably 3.0 GPa or greater, even more preferably 3.5 GPa or greater, even more preferably 4.0 GPa or greater, particularly preferably 4.5 GPa or greater, and most preferably 5.0 GPa or greater. The upper limit is not particularly limited, but is practically 12.0 GPa or less.

[0166] The elastic modulus of the adhesive layer can be calculated by testing a sample of the adhesive layer produced using the adhesive layer forming liquid in the same manner as the tensile elastic modulus of the resin film described above.

[0167] (Thickness of adhesive layer)

[0168] From the viewpoint of bonding two resin films, the thickness of the adhesive layer is preferably 10 nm or more, more preferably 10 nm to 10 μm, further preferably 10 nm to 5 μm, and even more preferably 10 nm to 1 μm, from the viewpoint of further reducing interference unevenness.

[0169] The adhesive layer can be formed, for example, by applying a coating liquid containing an adhesive to at least one surface of the resin film and drying the coating liquid. Any appropriate method can be used to prepare the coating liquid. For example, a commercially available solution or dispersion can be used as the coating liquid. A solvent can also be added to a commercially available solution or dispersion, or a solid component can be dissolved or dispersed in various solvents.

[0170] In one embodiment, the adhesive layer may be a cured layer formed by curing an active energy ray-curable composition. The active energy ray-curable composition used to form the adhesive layer preferably contains a cationic polymerizable compound as an active energy curable component, such as an epoxy compound, more specifically, an epoxy compound that does not have an aromatic ring in the molecule as described in Japanese Patent Application Laid-Open No. 2004-245925. As such epoxy compounds, for example, an aromatic polyhydroxy compound as a raw material of an aromatic epoxy compound, represented by diglycidyl ether of bisphenol A, is subjected to nuclear hydrogenation and glycidyl etherification to obtain a hydrogenated epoxy compound, an alicyclic epoxy compound having at least one epoxy group bonded to an alicyclic ring in the molecule, and an aliphatic epoxy compound represented by glycidyl ether of an aliphatic polyhydroxy compound. Furthermore, the active energy ray-curable composition used to form the adhesive layer may contain, in addition to a cationically polymerizable compound, typified by epoxy compounds, a polymerization initiator, such as a photocationic polymerization initiator that generates a cationic species or Lewis acid upon exposure to active energy rays and initiates polymerization of the cationically polymerizable compound, and a photobase generator that generates a base upon exposure to light. Furthermore, it may contain a thermal cationic polymerization initiator that initiates polymerization upon heating, as well as various additives such as a photosensitizer.

[0171] (Difference in tensile elastic modulus between the resin film and the adhesive layer)

[0172] The difference between the tensile elastic modulus of the two bonded resin films at 25°C and the tensile elastic modulus of the adhesive layer at 25°C is preferably independently 4.0 GPa or less, more preferably 3.5 GPa or less, further preferably 3.0 GPa or less, further preferably 2.5 GPa or less, further preferably 2.0 GPa or less, particularly preferably 1.5 GPa or less, and most preferably 1.0 GPa or less.

[0173] The optical film of the present invention may also have an adhesive layer on the face (the other surface) on the opposite side of the face with the adhesive layer when having a resin film formed by laminating 2 resin films by an adhesive layer. For example, a known polarizer protective film may be provided on the other surface via the adhesive layer. When adhesive layers are provided on both sides of the resin film, the composition for forming each adhesive layer may be the same or different. From the viewpoint of productivity, it is preferred that both sides have an adhesive layer formed by the same composition.

[0174] Before forming the adhesive layer, the surface to which the adhesive layer is to be formed may be subjected to at least one surface treatment such as saponification treatment, corona discharge treatment, and plasma treatment.

[0175] As the saponification treatment, for example, by subjecting a cellulose ester resin film to an alkali saponification treatment, adhesion with a polarizer material such as polyvinyl alcohol can be improved.

[0176] Regarding the saponification method, the following can be used: <0212> The method described in paragraph .

[0177] For example, alkali saponification treatment of a cellulose ester resin film is preferably performed in a cycle of immersing the film surface in an alkaline solution, neutralizing with an acidic solution, washing with water, and drying. Examples of the alkaline solution include potassium hydroxide solution and sodium hydroxide solution. The hydroxide ion concentration is preferably 0.1 to 5.0 mol / L, more preferably 0.5 to 4.0 mol / L. The temperature of the alkaline solution is preferably room temperature (25°C) to 90°C, more preferably 40 to 70°C.

[0178] Instead of the alkali saponification treatment, an adhesion-facilitating treatment as described in Japanese Patent Application Laid-Open No. 6-094915 or Japanese Patent Application Laid-Open No. 6-118232 may be performed.

[0179] As a method of bonding the resin films together using an adhesive, a known method can be used.

[0180] For example, the second resin film or the first resin film can be brought close to one surface of the first resin film or the second resin film in the form of a strip moving in the horizontal direction or the vertical direction at the same moving speed, and an adhesive is applied to form an adhesive layer in a manner so as to be located between the first resin film and the second resin film, and pressure is applied by a pinch roller to bond the two resin films. The applied adhesive can also be an adhesive in which the material constituting the adhesive layer is diluted with a solvent in a manner that allows it to be applied. At this time, the solvent in the adhesive layer is dried to complete the bonding of the two resin films. The drying temperature at this time depends on the type of solvent in the adhesive layer and the type and thickness of the resins of the two resin films. For example, when the solvent in the adhesive layer is water, it is preferably 30 to 85°C, and more preferably 45 to 80°C.

[0181] Furthermore, an adhesive forming an adhesive layer can be applied to one or both of the two resin films, and a drying process is performed to remove the solvent contained in the adhesive layer. After the adhesive layer is formed on the resin film, the other resin film is brought close to the surface of the resin film forming the adhesive layer at the same moving speed, and a solvent that swells the adhesive layer is applied between the two resin films forming the above-mentioned adhesive layer. Pressure is applied using pinch rollers to bond the two resin films. At this time, the solvent is dried, and the bonding of the two resin films is completed. The drying temperature at this time depends on the type of solvent and the type and thickness of the resin of the two resin films. For example, when the solvent is water, it is preferably 30 to 85°C, and more preferably 45 to 80°C.

[0182] (2) Impact absorbing layer

[0183] The optical film of the present invention has a shock absorbing layer on at least one side of the resin film. 6 Hz(1.0×10 6 Hz) and the storage modulus E' satisfies 1 GPa or less (1.0×10 3 MPa or less). The impact-absorbing layer can fully absorb external impacts. Therefore, when the optical film of the present invention is used as a front plate of a touch panel or a front plate of a touch panel display, or as a polarizing plate protective film, it can prevent damage to the internal materials of the display.

[0184] When the optical film of the present invention is used for a rear polarizing plate, the impact absorbing layer is heated at 25°C and a frequency of 10 6 Hz(1.0×10 6 The storage modulus E' at 100 Hz is preferably 700 MPa or less, more preferably 300 MPa or less, further preferably 100 MPa or less, and particularly preferably 10 MPa or less. The lower limit of the storage modulus E' is not particularly limited, but is practically 1 MPa or more.

[0185] When the rear polarizing plate includes two or more optical films of the present invention, the impact absorbing layer located on the side most opposite to the visual recognition side preferably has the above-mentioned preferred storage elastic modulus E'.

[0186] When the optical film of the present invention is used for a front polarizing plate, the impact absorbing layer is heated at 25°C and a frequency of 10 6 Hz(1.0×10 6 The storage elastic modulus E' at 100 Hz) is preferably 10 MPa or more and 700 MPa or less, more preferably 10 MPa or more and 300 MPa or less, and further preferably 10 MPa or more and 100 MPa or less.

[0187] When the front polarizing plate includes two or more optical films of the present invention, the impact-absorbing layer positioned closest to the visual recognition side preferably has the above-mentioned preferred storage elastic modulus E'.

[0188] The impact absorbing layer is preferably subjected to a temperature of 25°C and a frequency of 10 -1 ~10 15 Hz(1.0×10 -1 ~1.0×1015Hz) and more preferably has a maximum value of tanδ in the range of 10 3 ~10 15 Hz(1.0×10 3 ~1.0×10 15 Hz) has a maximum value, and more preferably has a maximum value within the range of 10 5 ~10 15 It has a maximum value in the range of Hz, and is particularly preferably in the range of 10 5 ~10 10 Hz(1.0×10 5 ~1.0×10 10 Hz) has a maximum value. At this time, at 25°C, at a frequency of 10 -1 ~10 15 It is sufficient to have at least one maximum value of tanδ within the range of Hz, or it can be within the range of 10 -1 ~10 15 There are two or more tanδ maxima in the range of Hz. -1 ~10 15 There is a maximum value of tan δ in a frequency range outside the Hz range, and this maximum value may be the maximum value of tan δ of the impact absorbing layer.

[0189] From the viewpoint of further improving the impact absorption property, the maximum value of tan δ of the impact absorbing layer at 25° C. within the above-mentioned preferred frequency range is preferably 1.0 or more, more preferably 1.5 or more.

[0190] When the rear polarizing plate includes two or more optical films of the present invention, the impact absorbing layer located on the side most opposite to the visual recognition side preferably has the preferred maximum value of tan δ.

[0191] Furthermore, when the front polarizing plate includes two or more optical films of the present invention, it is preferred that the impact absorbing layer positioned closest to the viewing side has the preferred maximum value of tan δ.

[0192] On the other hand, when the optical film of the present invention is used for a rear polarizing plate of a liquid crystal panel, the impact absorbing layer has a tan δ at 25° C. of 10 -1 ~10 6Hz(1.0×10 -1 ~1.0×10 6 Hz), preferably 3.0 or less, more preferably 1.0 or less, further preferably 0.5 or less, and particularly preferably 0.3 or less.

[0193] When the rear polarizing plate includes two or more optical films of the present invention, the impact absorbing layer located on the side most opposite to the visual recognition side preferably satisfies the aforementioned preferred tan δ requirements.

[0194] [Measurement of storage modulus and calculation of tanδ by dynamic viscoelasticity measurement]

[0195] In the present invention, the tensile deformation mode of the dynamic viscoelasticity measuring device is used to determine the 6 Storage elastic modulus E' at Hz. Similarly, regarding the relationship between frequency and tan δ of the impact absorbing layer at 25°C, a frequency-tan δ curve was prepared using the tensile deformation mode of a dynamic viscoelasticity measuring device, and the maximum value of tan δ and the frequency showing the maximum value were determined.

[0196] Specifically, the method described below was used.

[0197] <Sample Preparation Method>

[0198] A shock absorbing material (also referred to as a shock absorbing layer material or shock absorbing layer constituent material) such as the shock absorbing layer-forming composition described below is dissolved or melted in a solvent to obtain a coating liquid. This coating liquid is applied to the release-treated surface of a release-treated release PET (polyethylene terephthalate) sheet to a thickness of 40 μm after drying and dried. The shock absorbing layer is then peeled off the release PET sheet to prepare a test piece for the shock absorbing layer.

[0199] <Measurement Method>

[0200] Using a dynamic viscoelasticity measuring instrument (manufactured by IT Keisoku Seigyo Co., Ltd., product name: DVA-225), the test piece, previously conditioned at 25°C and 60% relative humidity for at least 2 hours, was measured in the "step temperature increase / frequency dispersion" mode under the following conditions. A master curve of tan δ, storage modulus, and loss elastic modulus versus frequency at 25°C was then generated using "Master Curve" editing. The maximum tan δ value and the frequency representing the maximum value were determined from the resulting master curve.

[0201] Specimen: 5mm×50mm

[0202] Test mode: tensile deformation mode

[0203] Distance between fixtures: 20mm

[0204] Set distortion: 0.10%

[0205] Measuring temperature: -100℃~40℃

[0206] Heating conditions: 2℃ / min

[0207] (Shock absorbing layer constituent materials)

[0208] As the above-mentioned 25°C, frequency 10 6 Hz(1.0×10 6 The material constituting the impact absorbing layer of the impact absorbing layer having a storage elastic modulus E' at 100 Hz of 1 GPa or less, when the optical film of the present invention is used as a front plate of a touch panel or a front plate of a touch panel display, or as a polarizing plate protective film, can be composed of a resin or an elastomer (including oil-plasticized rubber) as long as it has transparency that can ensure the visual recognition of the displayed content and can prevent damage to the internal materials of the display due to external impact.

[0209] Examples of the resin include polystyrene resins, polyamide resins, urethane resins, (meth)acrylate resins (also referred to as (meth)acrylic resins, which refer to (meth)acrylate resins, etc.), and modified resins thereof. Examples of the urethane resin include urethane-modified polyester resins and urethane resins.

[0210] Among the above resins, (meth)acrylate resins are preferred.

[0211] Examples of the elastomer include block (co)polymers of conjugated dienes and hydrogenated products thereof, (meth)acrylic block (co)polymers (for example, (co)polymers having poly(meth)acrylate as a block unit), styrene block (co)polymers and hydrogenated products thereof ((co)polymers having a polymer of an aromatic vinyl compound (preferably polystyrene) as a block unit and hydrogenated products thereof, for example, block copolymers of a polymer of an aromatic vinyl compound and a polymer containing a conjugated diene, and block copolymers of a polymer of an aromatic vinyl compound and a polymer containing a conjugated diene). The present invention also includes but is not limited to hydrogenated block copolymers, ethylene-α-olefin copolymers, polar group-modified olefin copolymers, elastomers composed of polar group-modified olefin copolymers and at least one of metal ions and metal compounds, nitrile rubbers such as acrylonitrile-butadiene rubber, butyl rubber, acrylic rubber, thermoplastic polyolefin elastomers (TPO), thermoplastic polyurethane elastomers (TPU), thermoplastic polyester elastomers (TPFE), thermoplastic polyamide elastomers (TPAE) and diene elastomers (such as 1,2-polybutadiene), silicone elastomers and fluorine-based elastomers.

[0212] The block (co)polymer of the conjugated diene does not contain a polystyrene block.

[0213] As the above-mentioned elastomer, preferably a (meth) acrylic block (co)polymer or a styrene block (co)polymer and its hydride. As the (meth) acrylic block (co)polymer, preferably a block copolymer of polymethyl methacrylate and polybutyl acrylate (also referred to as "PMMA-PnBA block copolymer") can be mentioned. As the styrene block (co)polymer and its hydride, preferably a block copolymer of a polymer containing at least one of isoprene and butadiene and polystyrene and its hydride can be mentioned. The polymer containing at least one of the above-mentioned isoprene and butadiene can contain butylene as a constituent component other than isoprene and butadiene.

[0214] Among them, the above-mentioned elastomer is more preferably a hydrogenated product of a (meth)acrylic block (co)polymer or a styrene block (co)polymer, and further preferably a hydrogenated product of a PMMA-PnBA copolymer or a block copolymer of a polymer containing at least one of isoprene and butadiene and polystyrene.

[0215] The resin or elastomer that can be contained in the impact-absorbing layer can be synthesized by a known method, or a commercially available product can be used. Examples of commercially available products include CLARITY LA 1114, CLARITY LA 2140, CLARITY LA 2250, CLARITY LA 2330, CLARITY LA 4285, HYBRAR 5127, HYBRAR 7311F, SEPTON 2104, and SEPTON 2063 (all manufactured by KURARAY CO., LTD.).

[0216] The impact absorbing layer is preferably formed using at least one of the above-mentioned resins and elastomers.

[0217] From the viewpoint of the balance between solubility in a solvent and the storage elastic modulus, the weight average molecular weight of the resin or elastomer is preferably 10,000 to 1,000,000, and more preferably 50,000 to 500,000.

[0218] When these resins or elastomers constitute the impact absorbing layer, they may be used alone as constituent materials.

[0219] Furthermore, as described later, when various additives are used in addition to the aforementioned resin or elastomer to form the impact absorbing layer, the content of the aforementioned resin or elastomer in the solids component of the impact absorbing layer is preferably 10% by mass or greater, more preferably 15% by mass or greater, and even more preferably 20% by mass or greater, taking into account the aforementioned storage modulus of the impact absorbing layer. The content of the aforementioned resin or elastomer is not particularly limited, but is, for example, preferably 99.9% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less.

[0220] When the impact absorbing layer is formed by using the polymerizable group-containing compound and polymerization initiator described later together with the above-mentioned resin or elastomer, or when the impact absorbing layer is formed by using the polymerizable group-containing compound and polymerization initiator described later instead of the above-mentioned resin or elastomer, the contents of these constituent materials (resin, elastomer, polymerizable group-containing compound, and polymerization initiator) in the total solid content can be described in terms of the content of the above-mentioned resin or elastomer.

[0221] Furthermore, in addition to the above-mentioned resins or elastomers, the impact absorbing layer may be formed using, as constituent materials, softeners, plasticizers, lubricants, crosslinking agents, crosslinking aids, photosensitizers, antioxidants, anti-aging agents, heat stabilizers, flame retardants, antibacterial agents, rust inhibitors, weathering agents, ultraviolet absorbers, tackifiers, nucleating agents, pigments, dyes, organic fillers, inorganic fillers, additives such as silane coupling agents and titanium coupling agents, compounds containing polymerizable groups, polymerization initiators, or compositions containing polymers other than the above-mentioned resins or elastomers (hereinafter referred to as "other polymers"). That is, the impact absorbing layer may also be formed using a resin composition or an elastomer composition.

[0222] Hereinafter, the composition for forming the impact-absorbing layer is referred to as a composition for forming the impact-absorbing layer.

[0223] The inorganic filler added to the impact-absorbing layer is not particularly limited. Examples of the inorganic filler include silica particles, zirconia particles, alumina particles, mica, and talc. These can be used alone or in combination of two or more. From the perspective of dispersibility in the impact-absorbing layer, silica particles are preferred.

[0224] To improve affinity with the resin constituting the impact-absorbing layer, the surface of the inorganic filler may be treated with a surface modifier having functional groups capable of bonding to or adsorbing the inorganic filler. Examples of such surface modifiers include silane, metal alkoxide surface modifiers such as aluminum, titanium, and zirconium, and surface modifiers having anionic groups such as phosphate, sulfate, sulfonic, and carboxylic acid groups.

[0225] If the balance between the storage modulus and tan δ in the impact absorbing layer is taken into account, the content of the inorganic filler in the solid component constituting the impact absorbing layer is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, and further preferably 5 to 15% by mass. The size (average primary particle size) of the inorganic filler is preferably 10 nm to 100 nm, more preferably 15 to 60 nm. The average primary particle size of the inorganic filler can be obtained based on an electron microscope photograph. If the particle size of the inorganic filler is above the preferred lower limit, the effect of improving the storage modulus is obtained. If it is below the preferred upper limit, there is no situation where it becomes the cause of the haze increase. The shape of the inorganic filler can be any one of plate-like, spherical and non-spherical.

[0226] Specific examples of inorganic fillers include ELCOMV-8802 (manufactured by JGC Catalysts and Chemicals Ltd., spherical silica fine particles with an average primary particle size of 12 nm), ELCOMV-8803 (manufactured by JGC Catalysts and Chemicals Ltd., irregularly shaped silica fine particles), MIBK-ST (manufactured by NISSAN CHEMICAL INDUSTRIES, LTD., spherical silica fine particles with an average primary particle size of 10 to 20 nm), MEK-AC-2140Z (manufactured by NISSAN CHEMICAL INDUSTRIES, LTD.), and ELCOMV-8803 (manufactured by JGC Catalysts and Chemicals Ltd., irregularly shaped silica fine particles). TD., spherical silica particles with an average primary particle size of 10 to 20 nm), MEK-AC-4130 (made by NISSAN CHEMICAL INDUSTRIES, LTD., spherical silica particles with an average primary particle size of 40 to 50 nm), MIBK-SD-L (made by NISSAN CHEMICAL INDUSTRIES, LTD., spherical silica particles with an average primary particle size of 40 to 50 nm) and MEK-AC-5140Z (made by NISSAN CHEMICAL INDUSTRIES, LTD., spherical silica particles with an average primary particle size of 70 to 100 nm), etc.

[0227] The tackifier added to the impact-absorbing layer is not particularly limited. Examples of the tackifier include rosin ester resins, hydrogenated rosin ester resins, petrochemical resins, hydrogenated petrochemical resins, terpene resins, terpene phenolic resins, aromatic modified terpene resins, hydrogenated terpene resins, and alkylphenol resins. These tackifiers may be used alone or in combination of two or more.

[0228] Considering the balance between the storage modulus and tan δ in the impact absorbing layer, the content of the thickener is preferably 1 to 80% by mass, more preferably 5 to 70% by mass, based on the solid content constituting the impact absorbing layer.

[0229] Specific examples of the tackifier include SUPERESTER A75, SUPERESTER A115, and SUPERESTER A125 (all rosin ester resins manufactured by Arakawa Chemical Industries, Ltd.), PETROTAC 60, PETROTAC 70, PETROTAC 90, PETROTAC 100, PETROTAC 100V, and PETROTAC 90HM (all petrochemical resins manufactured by TOSOH CORPORATION), YS POLYSTART 30, YS POLYSTART80, YSPOLYSTART100, YSPOLYSTART115, YSPOLYSTART130, YSPOLYSTART145 and YSPOLYSTART160 (all of the above are terpene phenolic resins manufactured by YASUHARA CHEMICAL CO., LTD.) and YSRESINPX800, YSRESINPX1000, YSRESINPX1150 and YSRESINPX1250 (all of the above are terpene resins manufactured by YASUHARA CHEMICAL CO., LTD.), etc.

[0230] The softener added to the impact-absorbing layer is not particularly limited. For example, at least one of various rubber and resin softeners, including naphthenic, paraffinic, and aromatic mineral oils, castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, wood wax, pine oil, olive oil, and synthetic oils, can be used. From the perspective of suppressing oozing, the number average molecular weight of the softener is preferably 200 or greater, more preferably 300 or greater. From the perspective of suppressing stickiness, the number average molecular weight is preferably 1000 or less, more preferably 800 or less.

[0231] Considering the balance between the storage modulus and tan δ in the impact absorbing layer, the content of the softener in the solid component constituting the impact absorbing layer is preferably 70 mass % or less, more preferably 10 mass % or more and 50 mass % or less.

[0232] Specific examples of the softener include MORESCOWHITE P-40, MORESCOWHITE P-55, MORESCOWHITE P-60, MORESCOWHITE P-70, MORESCOWHITE P-80, MORESCOWHITE P-100, MORESCOWHITE P-120, MORESCOWHITE P-150, MORESCOWHITE P-200, MORESCOWHITE P-260 and MORESCOWHITE P-350P (all of which are paraffin oils manufactured by MORESCO Corporation), Diana Process Oil NS-24, Diana Process Oil NS-100, DianaProcess Oil NM-26, DianaProcess Oil NM-68, DianaProcess Oil NM-150, DianaProcess Oil NM-280, DianaProcess Oil NP-24, DianaProcess Oil NU-80 and DianaProcess Oil NF-90 (all of the above are cycloparaffinic oils manufactured by Idemitsu Kosan Co., Ltd.) and DianaProcess Oil AC-12, DianaProcess Oil AC-460, DianaProcess Oil AE-24, DianaProcess Oil 1 lAE-50, DianaProcess Oil AE-200, DianaProcess Oil AH-16 and DianaProcess Oil AH-58 (all of the above are aromatic oils manufactured by Idemitsu Kosan Co., Ltd.), etc.

[0233] The polymerizable group-containing compound that can be contained in the impact-absorbing layer-forming composition, such as a resin composition or an elastomer composition, for forming the impact-absorbing layer may be any of a polymerizable group-containing polymer, a polymerizable group-containing oligomer, and a polymerizable group-containing monomer, or may be an elastomer (including rubber) having a polymerizable group. Specifically, commercially available products such as ARTPEARLRA331MB and ARTPEA RLRA341 (both manufactured by Negami Chemical Industrial Co., Ltd.), KURAPRENEUC-102M and KURAPRENEUC-203M (both manufactured by KURARAY CO., LTD.), and SERMELASTOMERSH3400M (manufactured by ASM Inc.) may be mentioned, as well as the radically polymerizable compounds and cationically polymerizable compounds described below.

[0234] When the resin composition or elastomer composition for forming the impact absorbing layer contains a polymerizable group-containing compound, the composition preferably further contains a polymerization initiator. Specific examples of the polymerization initiator include the polymerization initiators described below.

[0235] The impact absorbing layer is also preferably formed using a composition for forming an impact absorbing layer that does not contain the aforementioned resins or elastomers and that contains at least a compound containing a polymerizable group and a polymerization initiator. Preferred examples of such a composition include a composition containing a rubber such as polyisoprene containing a radically polymerizable group and a polymerization initiator, and curing the composition to obtain an impact absorbing layer.

[0236] (Thickness of shock absorbing layer)

[0237] From the viewpoint of further improving the impact absorption property, the thickness of the impact absorbing layer is preferably 1 μm to 100 μm, more preferably 5 μm to 80 μm, and even more preferably 10 μm to 80 μm.

[0238] (Method for forming shock-absorbing layer)

[0239] The method for forming the impact absorbing layer is not particularly limited, and examples thereof include coating, casting (solventless casting and solvent casting), pressing, extrusion, injection molding, casting, and inflation. Specifically, a liquid material comprising the impact absorbing layer constituent material dissolved or dispersed in a solvent, or a melt of the components constituting the impact absorbing material (specifically, the resin or elastomer, etc.) is prepared. This liquid material or melt is then applied to a resin film, and the solvent is then removed as necessary, thereby forming the impact absorbing layer on the resin film (or a resin film having an HC layer).

[0240] The solvent is not particularly limited, and for example, the description of the solvent in the curable composition for forming the HC layer can be applied. Preferred examples include methyl isobutyl ketone and toluene.

[0241] Furthermore, the mixing ratio of the solvent to the solid component is not particularly limited and can be adjusted as appropriate. For example, the ratio of the solid component to the total amount of the solvent and the solid component can be set to 10 to 90% by mass.

[0242] Furthermore, the impact absorbing layer material can be applied to the release-treated surface of a release sheet that has been subjected to a release treatment in the same manner as described above, and dried to form a sheet having an impact absorbing layer. The impact absorbing layer of the sheet can be bonded to a resin film to thereby produce an impact absorbing layer on the resin film (or a resin film having an HC layer).

[0243] When the impact absorbing layer is composed of a resin, the impact absorbing layer may be composed of an uncrosslinked resin or a resin that is at least partially crosslinked. There is no particular limitation on the method for crosslinking the resin, and for example, a method selected from the group consisting of electron beam irradiation, ultraviolet irradiation, and a crosslinking agent (e.g., an organic peroxide, etc.) may be cited. When crosslinking the resin by electron beam irradiation, the impact absorbing layer obtained before crosslinking is irradiated with an electron beam by an electron beam irradiation device, thereby forming crosslinks. Furthermore, in the case of ultraviolet irradiation, the impact absorbing layer obtained before crosslinking is irradiated with ultraviolet rays by an ultraviolet irradiation device, thereby forming crosslinks by the effect of a photosensitizer such as a photopolymerization initiator that is matched as needed. Furthermore, when a crosslinking agent is used, the impact absorbing layer obtained before crosslinking is heated in an atmosphere in which there is no air, such as a nitrogen atmosphere, thereby forming crosslinks by a crosslinking agent such as an organic peroxide and a crosslinking aid that are matched as needed.

[0244] When the polymerizable group-containing compound is contained, the impact absorbing layer is preferably formed by cross-linking using any one of electron beam irradiation, ultraviolet irradiation, and a cross-linking agent.

[0245] (Protective film layer of impact absorbing layer)

[0246] The optical film of the present invention preferably has a removable protective film layer on the side of the impact-absorbing layer opposite to the resin film. This protective film layer prevents damage to the impact-absorbing layer and adhesion of dust and dirt before use, and allows the film to be removed for use.

[0247] The protective film layer of the impact-absorbing layer is different from the protective film of a polarizing plate used as a component incorporated in a product, in that it is peeled off before use.

[0248] To facilitate removal of the protective film layer, a release layer may be provided between the protective film layer and the impact-absorbing layer. The method for providing the release layer is not particularly limited; for example, it can be provided by applying a release coating agent to at least one surface of the protective film layer or the impact-absorbing layer. The type of release coating agent is not particularly limited; examples include silicone coating agents, inorganic coating agents, fluorine coating agents, and organic-inorganic hybrid coating agents.

[0249] An optical film comprising a protective film layer and a release layer can generally be obtained by providing a release layer on the surface of the protective film layer and then laminating the release layer on the surface of the impact absorbing layer. In this case, the release layer may be provided on the surface of the impact absorbing layer instead of on the surface of the protective film layer.

[0250] (3) Hard coating (HC layer)

[0251] like Figure 2 As shown, the optical film of the present invention may also have a hard coating layer (Hc layer, 3A) on the surface opposite to the surface of the resin film 1A provided with the impact absorbing layer 2A. The optical film of the present invention having the hard coating layer can be used as a protective film for a front polarizer or a front panel of a touch panel. In this case, the hard coating layer is arranged on the visual recognition side, and the impact absorbing layer is opposite to the polarizer. That is, as the front polarizer, it has a laminated structure in which a hard coating layer, a resin film, an impact absorbing layer, and a polarizer are sequentially arranged from the visual recognition side. As the front panel of the touch panel, it has a laminated structure in which a hard coating layer, a resin film, an impact absorbing layer, and a touch sensor film are sequentially arranged from the visual recognition side.

[0252] The HC layer in the present invention is preferably formed by polymerizing and curing a polysiloxane-containing compound having a polymerizable group in its molecule, a fluorine-containing compound having a polymerizable group in its molecule, or a polymerizable compound having a polymerizable group in its molecule (described below) other than these compounds. More preferably, these polymerizable groups are free radical polymerizable groups. This allows the polysiloxane-containing compound and the fluorine-containing compound to be present in the HC layer in a bonded state with the polymerizable compound forming the HC layer, thereby imparting superior antifouling properties. If the polysiloxane-containing compound and the fluorine-containing compound used to form the HC layer have polymerizable groups, the polymerizable groups in the polysiloxane-containing compound and the fluorine-containing compound, described below, will react to form bonds and be present in the HC layer.

[0253] When the HC layer has a laminated structure of two or more layers as described below, the polysiloxane compound and the fluorine-containing compound preferably include at least the HC layer farthest from the resin film, and more preferably include only the HC layer farthest from the resin film.

[0254] Hereinafter, specific aspects of the HC layer will be described, but the present invention is not limited to the following aspects.

[0255] [Fluorinated compounds]

[0256] The fluorine-containing compound in the present invention is not particularly limited as long as it can impart wear resistance to the HC layer when used together with the polysiloxane-containing compound. Compounds having fluorine atoms in their molecules can be used. As the fluorine-containing compound, a fluorine-containing antifouling agent exhibiting antifouling properties is preferably used.

[0257] In the present invention, the fluorine-containing compound may be any of a monomer, oligomer, and polymer. The fluorine-containing compound preferably has a substituent that contributes to forming a bond with other components (e.g., a polysiloxane-containing compound, a polymerizable monomer as a component of the resin, and the resin) or contributing to compatibility in the HC layer. These substituents may be the same or different, and preferably, a plurality of substituents are present.

[0258] The substituent is preferably a polymerizable group, and any polymerizable reactive group exhibiting any of free radical polymerization, cationic polymerization, anionic polymerization, condensation polymerization, and addition polymerization is sufficient. Preferred examples of the substituent include acryloyl, methacryloyl, vinyl, allyl, cinnamoyl, epoxy, oxetanyl, hydroxy, polyoxyalkylene, carboxyl, and amino groups. Among these, free radical polymerizable groups are preferred, and acryloyl and methacryloyl groups are particularly preferred.

[0259] The fluorine-containing compound may be a polymer or oligomer having a compound containing no fluorine atoms as a copolymer component.

[0260] The fluorine-containing antifouling agent is preferably a fluorine-based compound represented by the following general formula (F).

[0261] General formula (F):

[0262] (R f )-[(W)-(R A ) n ] m

[0263] (Where R f represents a (per)fluoroalkyl group or a (per)fluoropolyether group, W represents a single bond or a connecting group, R A represents a polymerizable unsaturated group. n represents an integer of 1 to 3. m represents an integer of 1 to 3. The valence of the linking group in W is (n+1).

[0264] In the general formula (F), R A represents a polymerizable unsaturated group. The polymerizable unsaturated group is preferably a group having an unsaturated bond capable of inducing a free radical polymerization reaction upon irradiation with active energy rays such as ultraviolet rays and electron beams (i.e., a free radical polymerizable group), and examples thereof include (meth)acryloyl, (meth)acryloyloxy, vinyl, and allyl groups. Preferred are (meth)acryloyl and (meth)acryloyloxy groups, and groups in which any hydrogen atom in these groups is substituted with a fluorine atom.

[0265] In the general formula (F), R f represents a (per)fluoroalkyl group or a (per)fluoropolyether group.

[0266] Among them, (per)fluoroalkyl represents at least one of a fluoroalkyl group and a perfluoroalkyl group substituted with at least one fluorine atom, and (per)fluoropolyether represents at least one of a fluoropolyether group and a perfluoropolyether group substituted with at least one fluorine atom. f The content of fluorine atoms in it is high.

[0267] The (per)fluoroalkyl group is preferably a group having 1 to 20 carbon atoms, more preferably a group having 1 to 10 carbon atoms.

[0268] The (per)fluoroalkyl group may be a linear structure (e.g., -CF2CF3, -CH2(CF2)4H, -CH2(CF2)8CF3, and -CH2CH2(CF2)4H), a branched structure (e.g., -CH(CF3)2, -CH2CF(CF3)2, -CH(CH3)CF2CF3, and -CH(CH3)(CF2)5CF2H), or an alicyclic structure (preferably a 5-membered ring or a 6-membered ring, such as perfluorocyclohexyl and perfluorocyclopentyl, and alkyl groups substituted by these groups).

[0269] (Per) fluoropolyether group refers to a (per) fluoroalkyl group having an ether bond, and may be a monovalent group, a divalent group, or a trivalent group. Examples of the fluoropolyether group include -CH2OCH2CF2CF3, -CH2CH2OCH2C4F8H, -CH2CH2OCH2CH2C8F 17 , -CH2CH2OCF2CF2OCF2CF2H and a fluorocycloalkyl group having 4 to 20 carbon atoms and having 4 or more fluorine atoms. In addition, examples of perfluoropolyether groups include -(CF2O) p -(CF2CF2O) q -, -[CF(CF3)CF2O] p -[CF(CF3)] q -、-(CF2CF2CF2O) p -and-(CF2CF2O) p -wait.

[0270] The above-mentioned p and q each independently represent an integer of 0 to 20. However, p+q is an integer of 1 or greater.

[0271] The total of p and q is preferably 1-83, more preferably 1-43, and even more preferably 5-23.

[0272] From the viewpoint of excellent wear resistance, the above-mentioned fluorine-containing antifouling agent is particularly preferably one having -(CF2O) p -(CF2CF2O) q - represents a perfluoropolyether group.

[0273] In the present invention, the fluorinated antifouling agent preferably has a perfluoropolyether group and has a plurality of polymerizable unsaturated groups in one molecule.

[0274] In the general formula (F), W represents a single bond or a linking group. Examples of the linking group in W include alkylene, arylene, and heteroalkylene groups, as well as linking groups formed by combinations of these groups. These linking groups may also include functional groups such as oxy (—O—), carbonyl, carbonyloxy, carbonylimino, and sulfonamide groups, as well as combinations of these groups.

[0275] W is preferably an ethylene group, and more preferably an ethylene group bonded to a carbonylimino group.

[0276] The fluorine atom content of the fluorine-containing antifouling agent is not particularly limited, but is preferably 20% by mass or more, more preferably 30 to 70% by mass, and even more preferably 40 to 70% by mass.

[0277] Examples of preferred fluorine-containing antifouling agents include R-2020, M-2020, R-3833, M-3833 and OPTOOLDAC (the above are product names) manufactured by DAIKIN INDUSTRIES, LTD. and MEGAFACE F-171, F-172, F-179A, RS-78, RS-90, DEFENSAM CF-300 and MCF-323 (the above are product names) manufactured by DIC Corporation, but are not limited to these.

[0278] From the viewpoint of wear resistance, in the general formula (F), the product of n and m (n×m) is preferably 2 or more, more preferably 4 or more.

[0279] In the general formula (F), when n and m are both 1, specific examples of preferred embodiments include the following general formulae (F-1) to (F-3).

[0280] General formula (F-1):

[0281] R f2 (CF2CF2) p R 22 CH2CH2R 21 OCOCR 11 =CH2

[0282] (Where R f2 represents a fluorine atom or a fluoroalkyl group having 1 to 10 carbon atoms, R 11 represents a hydrogen atom or a methyl group, R 21 represents a single bond or an alkylene group, R 22 represents a single bond or a divalent linking group, p is an integer representing the degree of polymerization, and the degree of polymerization p is k (k is an integer of 3 or more).

[0283] In R 22When representing a divalent linking group, examples of the divalent linking group include the same groups as the divalent linking groups in W described above.

[0284] Examples of the fluorine-containing telomer-type (meth)acrylate in the general formula (F-1) include partially or completely fluorinated alkyl ester derivatives of (meth)acrylic acid.

[0285] When a telomerization reaction is used in the synthesis of the compound represented by the general formula (F-1), it may contain a plurality of fluorinated (meth)acrylates depending on the conditions of the telomerization reaction and the separation conditions of the reaction mixture. f2 (CF2CF2) p R 22 CH2CH2R 21 The p of O- is k, k+1, k+2, etc.

[0286] General formula (F-2):

[0287] F(CF2) q -CH2-CHX-CH2Y

[0288] (In the formula, q represents an integer of 1 to 20, X and Y represent a (meth)acryloyloxy group or a hydroxyl group, and at least one of X and Y is a (meth)acryloyloxy group.)

[0289] The fluorine-containing (meth)acrylate represented by the general formula (F-2) has a fluoroalkyl group having 1 to 20 carbon atoms and a trifluoromethyl group (-CF3) at the terminal. Even when a small amount of the fluorine-containing (meth)acrylate is used, the trifluoromethyl groups can be effectively aligned on the surface.

[0290] From the viewpoint of wear resistance and ease of compound production, q is preferably an integer of 6 to 20, more preferably an integer of 8 to 10. Fluorine-containing (meth)acrylates having a fluoroalkyl group having 8 to 10 carbon atoms also exhibit superior effects in reducing the friction coefficient compared to fluorine-containing (meth)acrylates having fluoroalkyl groups of other chain lengths (number of carbon atoms), and also exhibit excellent wear resistance.

[0291] Specific examples of the fluorine-containing (meth)acrylate represented by the general formula (F-2) include 1-(meth)acryloyloxy-2-hydroxy-4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,13-heneicocarbonfluorotridecane, 2-(meth)acryloyloxy-1-hydroxy-4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,13-heneicocarbonfluorotridecane, and 1,2-bis(meth)acryloyloxy-4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,13-heneicocarbonfluorotridecane. In the present invention, 1-acryloyloxy-2-hydroxy-4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,13-heneicosafluorotridecane is preferred.

[0292] General formula (F-3):

[0293] F(CF2) r O(CF2CF2O) s CF2CH2OCOCR 3 =CH2

[0294] (Where R 3 is a hydrogen atom or a methyl group, s is an integer from 1 to 20, and r is an integer from 1 to 4.

[0295] The fluorine-containing monofunctional (meth)acrylate represented by the general formula (F-3) can be obtained by reacting a fluorine-containing alcohol compound represented by the following general formula (FG-3) with a (meth)acrylic acid halide.

[0296] General formula (FG-3):

[0297] F(CF2) r O(CF2CF2O) s CF2CH2OH

[0298] (In general formula (FG-3), s represents an integer of 1 to 20, and r represents an integer of 1 to 4.)

[0299] Specific examples of the fluorine-containing alcohol compound represented by the general formula (FG-3) include 1H,1H-perfluoro-3,6-dioxoheptane-1-ol, 1H,1H-perfluoro-3,6-dioxooctane-1-ol, 1H,1H-perfluoro-3,6-dioxadecan-1-ol, 1H,1H-perfluoro-3,6,9-trioxadecan-1-ol, 1H,1H-perfluoro-3,6,9-trioxaundecan-1-ol, 1H,1H-perfluoro-3,6,9-trioxatridecan-1-ol, 1H,1H-perfluoro-3,6,9,12-tetraoxatridecan-1-ol, 1H,1H-perfluoro-3,6,9,12-tetraoxatetradecane-1-ol, and 1H,1H-perfluoro-3,6,9,12-tetraoxatetradecane-1-ol. Hexadecane-1-ol, 1H,1H-perfluoro-3,6,9,12,15-pentaoxahexadecan-1-ol, 1H,1H-perfluoro-3,6,9,12,15-pentaoxaheptadecan-1-ol, 1H,1H-perfluoro-3,6,9,12,15-pentaoxaheptadecan-1-ol, 1H,1H-perfluoro-3,6,9,12,15-pentaoxaheptadecan-1-ol, 1H,1H-perfluoro-3,6,9,12,15-pentaoxaheptadecan-1-ol, 8-hexaoxaicosane-1-ol, 1H,1H-perfluoro-3,6,9,12,15,18-hexaoxadocosan-1-ol, 1H,1H-perfluoro-3,6,9,12,15,18,21-heptaoxatriacosan-1-ol and 1H,1H-perfluoro-3,6,9,12,15,18,21-heptaoxapentacosan-1-ol, etc.

[0300] These are commercially available products. Specific examples thereof include 1H,1H-perfluoro-3,6-dioxaheptane-1-ol (product name "C5GOL", manufactured by EXFloor), 1H,1H-perfluoro-3,6,9-trioxadecan-1-ol (product name "C7GOL", manufactured by EXFloor), 1H,1H-perfluoro-3,6-dioxadecan-1-ol (product name "C8GOL", manufactured by EXFloor), 1H,1H-perfluoro-3,6,9-trioxatridecan-1-ol (product name "C10GOL", manufactured by EXFloor), and 1H,1H-perfluoro-3,6,9,12-tetraoxahexadecan-1-ol (product name "C12GOL", manufactured by EXFloor).

[0301] In the present invention, 1H,1H-perfluoro-3,6,9,12-tetraoxatridecan-1-ol is preferably used.

[0302] Examples of the (meth)acrylic acid halide to be reacted with the fluorine-containing alcohol compound represented by the general formula (FG-3) include (meth)acrylic acid fluoride, (meth)acrylic acid chloride, (meth)acrylic acid bromide, and (meth)acrylic acid iodide. (Meth)acrylic acid chloride is preferred from the viewpoint of availability.

[0303] Preferred specific examples of the compound represented by the general formula (F-3) are shown below, but the present invention is not limited thereto. Preferred specific examples of the compound represented by the general formula (F-3) are also described in Japanese Patent Application Laid-Open No. 2007-264221.

[0304] (b-1): F9C4OC2F4OC2F4OCF2CH2OCOCH=CH2

[0305] (b-2): F9C4OC2F4OC2F4OCF2CH2OCOC(CH3)=CH2

[0306] Furthermore, in addition to the compound represented by the general formula (F-3), a compound represented by the following general formula (F-3)' can also be preferably used.

[0307] General formula (F-3)':

[0308] R f3 -[(O) c (O=C) b (CX 4 X 5 ) a -CX 3 =CX 1 X 2 ]

[0309] (Where, X 1 and X 2 Indicates H or F, X 3 represents H, F, CH3 or CF3, X 4 and X 5 represents H, F or CF3, a, b and c represent 0 or 1, R f3 It represents a fluorine-containing organic group having 18 to 200 carbon atoms and containing an ether bond.

[0310] The compound represented by the above general formula (F-3)' is f3 The group has 6 or more of the general formula (FG-3)':-(CX 6 2CF2CF2O)-(where X 6 The fluorine-containing unsaturated compound is a repeating unit represented by F or H).

[0311] Examples of the fluorinated polyether compound represented by the general formula (F-3)' include:

[0312] (c-1)R f3 -[(O)(O=C) b -CX 3 =CX 1 X 2 ]

[0313] (c-2)R f3 -[(O)(O=C)-CX 3 =CX 1 X 2 ]

[0314] (c-3)R f3 -[(O) c (O=C)-CF=CH2]

[0315] etc. (The definitions of the symbols in (c-1) to (c-3) are the same as in the general formula (FG-3)').

[0316] As the polymerizable unsaturated group of the fluorine-containing polyether compound, a group having the following structure can be preferably contained.

[0317] Furthermore, the fluorine-containing polyether compound represented by the above general formula (F-3)' may have a plurality of polymerizable unsaturated groups.

[0318] In the present invention, compounds having a structure of -O(C=O)CF=CH2 are preferred because they have particularly high polymerization (curing) reactivity and can efficiently produce a cured product.

[0319] The fluorinated polyether compound represented by the general formula (F-3)' is f3 It is important that the base contains 6 or more fluorinated polyether chains represented by the general formula (FG-3)' in terms of repeating units, because this can impart wear resistance.

[0320] Furthermore, it may be a mixture of compounds having 6 or more repeating units of the above-mentioned fluorinated polyether chain. When used as a mixture, among the distribution of the above-mentioned fluorinated unsaturated compounds having less than 6 repeating units and the fluorinated unsaturated compounds having 6 or more repeating units, the mixture in which the abundance ratio of the fluorinated unsaturated compounds having 6 or more repeating units of the polyether chain is the highest is preferred.

[0321] The number of repeating units of the fluorinated polyether chain represented by the general formula (FG-3)' is 6 or more, preferably 10 or more, more preferably 18 or more, and even more preferably 20 or more. This can reduce the dynamic friction coefficient and improve wear resistance. In addition, the fluorinated polyether chain may be present in R f3The end of the base can also be present in the chain.

[0322] R f3 Specifically, it is preferably composed of

[0323] General formula (c-4):

[0324] R 4 -(CX 6 2CF2CF2O) t -(R 5 ) e -(where X 6 and X in the fluorinated polyether chain represented by formula (FG-3)' 6 Same meaning, R 4 represents a hydrogen atom, a halogen atom, an alkyl group, a fluorinated alkyl group, an alkyl group containing an ether bond, or a fluorinated alkyl group containing an ether bond, and R 5 represents a divalent or higher valent organic group, t represents an integer of 6 to 66, and e represents 0 or 1. ) represents a group.

[0325] That is, R f3 The group is preferably a divalent or higher organic group R 5 Bonded to a reactive carbon-carbon double bond, and further having R at the end 4 fluorinated organic groups.

[0326] R 5 Any organic group may be used as long as it is capable of bonding the fluorinated polyether chain represented by the general formula (FG-3)' to a reactive carbon-carbon double bond. For example, an alkylene group, a fluorinated alkylene group, an alkylene group containing an ether bond, and a fluorinated alkylene group containing an ether bond may be mentioned. Among these, at least one of a fluorinated alkylene group and a fluorinated alkylene group containing an ether bond is preferred from the perspectives of transparency and low refractive index.

[0327] Specific examples of the fluorinated polyether compound represented by the general formula (F-3)' include compounds listed in Republished Patent No. WO2003 / 022906. In the present invention, CH2=CF-COO-CH2CF2CF2-(OCF2CF2CF2)7-OC3F7 can be particularly preferably used.

[0328] In the general formula (F), when n and m are not 1 at the same time, preferred embodiments include the general formula (F-4) and the general formula (F-5).

[0329] General formula (F-4):

[0330] (R f1 )-[(W)-(R A ) n ] m

[0331] (In the general formula (F-4), R f1 represents a (per)fluoroalkyl group or a (per)fluoropolyether group, W represents a connecting group, R A represents a polymerizable unsaturated group. n represents an integer of 1 to 3, m represents an integer of 1 to 3, and n and m are not 1 at the same time.

[0332] From the viewpoint of excellent water and oil repellency and excellent durability of the water and oil repellency (antifouling durability), n is preferably 2 or 3 and m is an integer of 1 to 3, more preferably n is 2 or 3 and m is 2 or 3, and even more preferably n is 3 and m is 2 or 3.

[0333] R f1 Monovalent to trivalent groups can be used. f1 When it is monovalent, as the terminal group, it is preferably (C n F 2n+1 )-、(C n F 2n+1 O)-、(XC n F 2n O)-、(XC n F 2n+1 )-(wherein X is a hydrogen atom, a chlorine atom or a bromine atom, and n is an integer of 1 to 10). Specifically, CF3O(C2F4O) can be preferably used. p CF2-, C3F7O (CF2CF2CF2O) p CF2CF2-, C3F7O(CF(CF3)CF2O) p CF(CF3)- and F(CF(CF3)CF2O) p CF(CF3)-etc.

[0334] The average value of p is 0 to 50, preferably 3 to 30, more preferably 3 to 20, and even more preferably 4 to 15.

[0335] In R f1 In the case of divalent, -(CF2O) can be preferably used. q (C2F4O) r CF2-, -(CF2)3O(C4F8O) r (CF2)3-, -CF2O(C2F4O) r CF2-, -C2F4O(C3F6O) r C2F4-, -CF(CF3)(OCF2CF(CF3)) s OC t F 2t O(CF(CF3)CF2O) rCF(CF3)- and -(CF(CF3)CF2O) p CF(CF3)-etc.

[0336] The average value of p, q, r, and s in the formula is 0 to 50, preferably 3 to 30, more preferably 3 to 20, and most preferably 4 to 15. t is an integer of 2 to 6.

[0337] Preferred specific examples and synthesis methods of the compound represented by general formula (F-4) are described in International Publication No. 2005 / 113690.

[0338] In the following, F(CF(CF3)CF2O) p Compounds with an average p value of 6 to 7 in CF(CF3)- are described as "HFPO-", and -(CF(CF3)CF2O) p Compounds in which the average value of p in CF(CF3)- is 6 to 7 are described as "-HFPO-", and specific compounds of the general formula (F-4) are shown, but the present invention is not limited to these.

[0339] (d-1):HFPO-CONH-C-(CH2OCOCH=CH2)2CH2CH3

[0340] (d-2):HFPO-CONH-C-(CH2OCOCH=CH2)2H

[0341] (d-3): 1:1 Michael addition polymer of HFPO-CONH-C3H6NHCH3 and trimethylolpropane triacrylate

[0342] (d-4): (CH2=CHCOOCH2)2H-C-CONH-HFPO-CONH-(CH2OCOCH=CH2)2H

[0343] (d-5): (CH2=CHCOOCH2)3-C-CONH-HFPO-CONH-C-(CH2OCOCH=CH2)3

[0344] Furthermore, as the compound represented by the general formula (F-4), a compound represented by the following general formula (F-5) can be used.

[0345] General formula (F-5):

[0346] CH2=CX 1 -COO-CHY-CH2-OCO-CX 2 =CH2

[0347] (Where X 1 and X 2represents a hydrogen atom or a methyl group, and Y represents a fluoroalkyl group having 2 to 20 carbon atoms and having 3 or more fluorine atoms, or a fluorocycloalkyl group having 4 to 20 carbon atoms and having 4 or more fluorine atoms.

[0348] In the present invention, the compound whose polymerizable unsaturated group is a (meth)acryloyloxy group may have multiple (meth)acryloyloxy groups. When the fluorinated antifouling agent has multiple (meth)acryloyloxy groups, it forms a three-dimensional network structure upon curing, resulting in a higher glass transition temperature, lower antifouling agent migration, and improved durability against repeated wiping of dirt. Furthermore, it is possible to obtain an HC layer with excellent heat resistance and weather resistance.

[0349] Specific examples of the compound represented by the general formula (F-5) include preferably 2,2,2-trifluoroethyl glycol di(meth)acrylate, 2,2,3,3,3-pentafluoropropyl glycol di(meth)acrylate, 2,2,3,3,4,4,4-heptafluorobutyl glycol di(meth)acrylate, 2,2,3,3,4,4,5,5,5-nonafluoropentyl glycol di(meth)acrylate, 2,2,3,3,4,4,5,5,5-nonafluoropentyl glycol di(meth)acrylate, 3,3,4,4,5,5,6,6,6-undecafluorohexyl glycol, 2,2,3,3,4,4,5,5,6,6,7,7,7-tridecafluoroheptyl glycol di(meth)acrylate, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl glycol di(meth)acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl glycol di(meth)acrylate Ethylene glycol, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononyl glycol di(meth)acrylate, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-nineteenfluorodecyl glycol di(meth)acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,1 0-heptadecafluorodecyl glycol, 2-trifluoromethyl-3,3,3-trifluoropropyl glycol di(meth)acrylate, 3-trifluoromethyl-4,4,4-trifluorobutyl glycol di(meth)acrylate, 1-methyl-2,2,3,3,3-pentafluoropropyl glycol di(meth)acrylate, and 1-methyl-2,2,3,3,4,4,4-heptafluorobutyl glycol di(meth)acrylate can be used alone or as a mixture. These di(meth)acrylates can be prepared by the known methods described in Japanese Patent Application Laid-Open No. 6-306326. In the present invention, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononyl glycol di(meth)acrylate is preferably used.

[0350] In the present invention, the compound having a (meth)acryloyloxy group as the polymerizable unsaturated group may be a compound having a plurality of (per)fluoroalkyl groups or (per)fluoropolyether groups in one molecule.

[0351] (Molecular weight of fluorinated compound)

[0352] The weight average molecular weight (Mw) of the fluorine-containing compound having a polymerizable unsaturated group can be measured using molecular exclusion chromatography, for example, gel permeation chromatography (GPC).

[0353] The Mw of the fluorinated compound used in the present invention is preferably 400 or greater and less than 50,000, more preferably 400 or greater and less than 30,000, and even more preferably 400 or greater and less than 25,000. A Mw exceeding this preferred lower limit is preferred because surface transferability to the HC layer of the antifouling agent is enhanced. Furthermore, a Mw below this preferred upper limit is preferred because surface transferability of the fluorinated compound is not impaired during the curing process after application of the HC layer-forming curable composition, making it easier to uniformly localize the HC layer surface, thereby improving abrasion resistance and film hardness. Furthermore, the fluorinated compound may have multimodal properties in terms of weight-average molecular weight.

[0354] (Amount of fluorinated compound added)

[0355] The amount of the fluorinated compound added is preferably 0.01 to 5% by mass, more preferably 0.1 to 5% by mass, even more preferably 0.5 to 5% by mass, and particularly preferably 0.5 to 2% by mass, relative to the total solids content of the curable composition for forming the HC layer. If the amount added is below the preferred upper limit, the coefficient of friction against steel wool can be reduced, further improving wear resistance. Furthermore, if the amount added is above the preferred lower limit, insufficient mixing of the fluorinated compound with the polymerizable compound (the resin component when forming the HC layer) in the curable composition for forming the HC layer prevents precipitation on the surface, thereby suppressing whitening of the HC layer or the generation of white powder on the surface.

[0356] When the HC layer has a laminated structure of two or more layers as described later, the amount added to the curable composition for forming the HC layer containing the fluorine-containing compound and the polysiloxane-containing compound is referred to.

[0357] [Polysilicone compound containing]

[0358] The polysiloxane-containing compound in the present invention is not particularly limited as long as it can impart antifouling properties to the HC layer when used together with the fluorine-containing compound, and compounds having a polysiloxane structure in the molecule can be used.

[0359] The polysiloxane structure of the polysiloxane-containing compound may be any of linear, branched, and cyclic.

[0360] As the polysiloxane-containing compound, a polysiloxane antifouling agent exhibiting properties of an antifouling agent is preferably used.

[0361] The polysiloxane antifouling agent is preferably represented by the following general formula (F-6).

[0362] General formula (F-6):

[0363] R a R A b SiO (4-a-b) / 2

[0364] (wherein, R is a hydrogen atom, a methyl group, an ethyl group, a propyl group or a phenyl group, R A is an organic group containing a polymerizable unsaturated group, 0<a, 0<b and a+b<4.

[0365] a is preferably 1 to 2.75, more preferably 1 to 2.5. When a is 1 or greater, the synthesis of the compound becomes industrially easy, and when a is 2.75 or less, it is easy to achieve both curability and antifouling properties.

[0366] As R A The polymerizable unsaturated group in the formula (F) may be R A The same polymerizable unsaturated group (ie, radical polymerizable group) is preferably a (meth)acryloyl group, a (meth)acryloyloxy group, or a group in which any hydrogen atom in these groups is substituted with a fluorine atom.

[0367] Similarly, in the polysiloxane antifouling agent, from the viewpoint of film strength, it is preferred to have a plurality of polymerizable unsaturated groups in one molecule, and polydimethylsiloxane having a plurality of polymerizable unsaturated groups in one molecule is more preferred.

[0368] Preferred examples of polysiloxane antifouling agents include those having a substituent at at least one of the ends or side chains of a compound chain containing multiple dimethylsiloxy units as repeating units. The compound chain containing dimethylsiloxy units as repeating units may contain structural units other than dimethylsiloxy groups. The substituents may be the same or different, but preferably, there are multiple substituents.

[0369] The substituent is preferably a polymerizable group, and any polymerizable group exhibiting free radical polymerization, cationic polymerization, anionic polymerization, condensation polymerization, and addition polymerization may be used. Preferred examples of substituents include groups containing (meth)acryloyl, (meth)acryloyloxy, vinyl, allyl, cinnamoyl, epoxy, oxetanyl, hydroxyl, fluoroalkyl, polyoxyalkylene, carboxyl, and amino groups. Among these, free radical polymerizable groups are preferred, and (meth)acryloyloxy groups are particularly preferred from the perspective of improving antifouling properties.

[0370] Furthermore, from the perspective of achieving a balance between film strength and antifouling properties, the number of substituents in the compound, as a functional group equivalent, is preferably 100 to 10,000 g / mol, more preferably 100 to 3,000 g / mol, even more preferably 100 to 2,000 g / mol, and particularly preferably 100 to 1,000 g / mol. Setting the functional group equivalent above the preferred lower limit is preferred because it prevents excessive compatibility with the polymerizable compound (the resin component when forming the HC layer) in the curable composition for forming the HC layer, thereby improving the surface transferability of the antifouling agent within the HC layer. Setting the functional group equivalent below the preferred upper limit is preferred because it increases film hardness and improves antifouling properties.

[0371] R A An organic group containing a (meth)acryloyl group is preferred. From the perspective of ease of industrial synthesis, it is more preferred that the bond between the organic group and the Si atom be a Si-OC bond. b is preferably 0.4 to 0.8, more preferably 0.6 to 0.8. When b is above the preferred lower limit, curability is improved, while when it is below the preferred upper limit, antifouling properties are improved.

[0372] Furthermore, a+b is preferably 3 to 3.7, more preferably 3 to 3.5. If it is above the preferred lower limit, the compound is easily localized on the surface of the HC layer, while if it is below the preferred upper limit, both curability and antifouling properties can be achieved.

[0373] The polysiloxane antifouling agent preferably has 3 or more Si atoms in one molecule, more preferably 3 to 40 Si atoms. If the number of Si atoms is 3 or more, localization of the compound on the surface of the HC layer is promoted, making it easier to obtain sufficient antifouling properties.

[0374] The polysiloxane antifouling agent can be produced using a known method such as that listed in Japanese Patent Application Laid-Open No. 2007-145884.

[0375] As an additive having a polysiloxane structure, polysiloxane (e.g., "KF-96-10CS", "KF-100T", "X-22-169AS", "KF-102", "X-22-3701IE", "X-22-164", "X-22-164A", "X-22-164AS", "X-22-164B", "X-22-164C", "X-22-5002", "X-22-173B", "X-22-174D", "X-22-167B" and "X-22-161AS" (product names)) is also preferably added. Co., Ltd.; "AK-5", "AK-30" and "AK-32" (product names), all manufactured by TOAGOSEI CO., LTD.; "SILAPLANE FM0725" and "SILAPLANE FM0721" (product names), all manufactured by Chisso Corporation; "DMS-U22", "RMS-033" and "UMS-182" (product names), all manufactured by Gelest; "Akrit 8SS-723" (product name), all manufactured by TAISEIFINE CHEMICAL CO., LTD.). In addition, the polysiloxane compounds described in Table 2 and Table 3 of JP-A-2003-112383 can also be preferably used.

[0376] [Molecular weight of polysiloxane-containing compound]

[0377] The weight average molecular weight of the polysiloxane-containing compound is preferably 300 or greater, more preferably 300 or greater and 100,000 or less, and even more preferably 300 or greater and 30,000 or less. When the weight average molecular weight of the polysiloxane-containing compound is 300 or greater, localization of the polysiloxane-containing compound on the surface of the HC layer is promoted, further improving wear resistance and hardness.

[0378] [Addition amount of polysiloxane-containing compound]

[0379] The amount of the polysiloxane-containing compound added relative to the total solids content of the HC layer-forming curable composition is preferably 0.01 to 5% by mass, more preferably 0.1 to 5% by mass, even more preferably 0.5 to 5% by mass, and particularly preferably 0.5 to 2% by mass. When the amount added is above the preferred lower limit, antifouling properties can be further improved. Furthermore, when the amount added is below the preferred upper limit, the polysiloxane compound that has not been sufficiently mixed with the polymerizable compound (the resin component when forming the HC layer) in the HC layer-forming curable composition is prevented from precipitating on the surface, thereby suppressing whitening of the HC layer or the generation of white powder on the surface.

[0380] In addition, when the HC layer has a laminated structure of two or more layers as described later, it means the amount added to the curable composition for forming the HC layer containing the polysiloxane compound.

[0381] (Surface roughness Sa of the hard coat layer in the optical film)

[0382] In the present invention, the surface roughness Sa of the hard coat layer in the optical film refers to the surface roughness of the surface opposite to the surface having the resin film in a state where the resin film and the hard coat layer are laminated (hereinafter also referred to as simply the surface roughness Sa).

[0383] The surface roughness Sa of the hard coat layer is preferably 60 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less in a measurement field of view of 4 mm×5 mm. In practice, the lower limit is 1 nm or more.

[0384] In addition, in the case where the hard coating layer has other layers described later on the surface opposite to the surface having the resin film (hereinafter also referred to as the surface on the visual recognition side), the above-mentioned "surface roughness Sa of the hard coating layer" refers to the surface roughness Sa of the hard coating layer measured when the hard coating layer is located on the outermost surface of the optical film on the visual recognition side of the optical film.

[0385] (HC layer formed by curing the curable composition for forming a hard coat layer (HC layer))

[0386] The HC layer used in the present invention can be obtained by irradiating a curable composition for forming the HC layer with active energy rays and curing the composition. As used herein, "active energy rays" refers to ionizing radiation, including X-rays, ultraviolet rays, visible light, infrared rays, electron beams, α-rays, β-rays, and γ-rays.

[0387] The HC layer-forming curable composition used to form the HC layer contains at least one component (hereinafter also referred to as an "active energy ray-curable component") that has the property of curing upon exposure to active energy rays. The active energy ray-curable component is preferably at least one of a free radical polymerizable compound and a cationically polymerizable compound. In this specification, a "polymerizable compound" refers to a compound having a polymerizable group in its molecule; the polymerizable group may be present in one or more molecules. A polymerizable group is a group capable of participating in a polymerization reaction. Specific examples include the groups contained in the various polymerizable compounds described below. Examples of polymerization reactions include free radical polymerization, cationic polymerization, and anionic polymerization.

[0388] Furthermore, the HC layer in the present invention is preferably obtained by irradiating an HC layer-forming curable composition containing a polysiloxane-containing compound having a polymerizable group in its molecule, a fluorine-containing compound having a polymerizable group in its molecule, and a polymerizable compound having a polymerizable group other than these compounds by irradiating the composition with active energy rays to cause polymerization and curing. In this case, it is more preferable that the polymerizable groups possessed by the polysiloxane-containing compound, the fluorine-containing compound, and the polymerizable compound are radically polymerizable groups.

[0389] The HC layer used in the present invention may have a single-layer structure or a laminated structure of two or more layers, and is preferably a HC layer composed of a single-layer structure or a laminated structure of two or more layers as described in detail below.

[0390] 1) 1-layer structure

[0391] A preferred embodiment of a curable composition for forming a HC layer in a single-layer structure includes, as a first embodiment, a curable composition for forming an HC layer containing at least one polymerizable compound having two or more ethylenically unsaturated groups per molecule. An ethylenically unsaturated group refers to a functional group containing an ethylenically unsaturated double bond.

[0392] Examples of the polymerizable compound having two or more ethylenically unsaturated groups in one molecule contained in the curable composition for forming the HC layer of the first embodiment include esters of polyols and (meth)acrylic acid [e.g., ethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, 1,4-cyclohexane diacrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dimethoxypropane tri ... Pentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, pentaerythritol hexa(meth)acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate and polyester polyacrylate], ethylene oxide-modified products, polyethylene oxide-modified products and caprolactone-modified products of the above esters, vinylbenzene and its derivatives [for example, 1,4-divinylbenzene, 2-acryloylethyl 4-vinylbenzoate and 1,4-divinylcyclohexanone], vinyl sulfones (for example, divinyl sulfone) and acrylamides (for example, methylenebisacrylamide) and methacrylamide.

[0393] Polymerization of the polymerizable compound having two or more ethylenically unsaturated groups per molecule can be carried out by irradiation with active energy rays in the presence of a radical photopolymerization initiator. The radical photopolymerization initiator described below is preferably used as the radical photopolymerization initiator. Furthermore, regarding the content ratio of the radical photopolymerization initiator to the polymerizable compound having an ethylenically unsaturated group in the curable composition for forming the HC layer, the content ratio of the radical photopolymerization initiator to the radical polymerizable compound described below is preferably applied.

[0394] Furthermore, as a second embodiment, a curable composition for forming an HC layer containing at least one radical polymerizable compound (B) and at least one cationically polymerizable compound (A) can be cited. As a preferred embodiment, a curable composition for forming an HC layer containing the following can be cited:

[0395] (b-1) a radically polymerizable compound containing at least one radically polymerizable group selected from two or more acryloyl groups and methacryloyl groups in one molecule; and

[0396] (A) Cationic polymerizable compound.

[0397] The HC layer-forming curable composition more preferably contains a radical photopolymerization initiator and a cationic photopolymerization initiator. As a preferred embodiment of the second embodiment, a HC layer-forming curable composition containing the following can be cited:

[0398] (b-1) a radically polymerizable compound containing at least one radically polymerizable group selected from two or more acryloyl groups and methacryloyl groups in one molecule;

[0399] (A) a cationically polymerizable compound;

[0400] Free radical photopolymerization initiator; and

[0401] Cationic photopolymerization initiator.

[0402] Hereinafter, this aspect will be described as the second aspect (1).

[0403] In the second aspect (1), the radically polymerizable compound preferably contains two or more radically polymerizable groups in one molecule and one or more urethane bonds in one molecule.

[0404] In another preferred embodiment of the second embodiment, there can be mentioned a curable composition for forming an HC layer containing:

[0405] (a-1) a cationically polymerizable compound containing an alicyclic epoxy group and an ethylenically unsaturated group, wherein the number of the alicyclic epoxy group contained in one molecule is one, the number of the ethylenically unsaturated group contained in one molecule is one, and the molecular weight is 300 or less;

[0406] (b-2) a radically polymerizable compound containing three or more ethylenically unsaturated groups in one molecule;

[0407] (c) a free radical polymerization initiator; and

[0408] (d) Cationic polymerization initiator.

[0409] Hereinafter, this embodiment will be referred to as the second embodiment (2). The HC layer formed by curing the HC layer-forming curable composition of the second embodiment (2) preferably contains, when the total solid content of the HC layer is 100% by mass, 15 to 70% by mass of the structure derived from (a-1), 25 to 80% by mass of the structure derived from (b-2), 0.1 to 10% by mass of (c), and 0.1 to 10% by mass of (d). Furthermore, in one embodiment, the HC layer-forming curable composition of the second embodiment (2) preferably contains 15 to 70% by mass of (a-1), when the total solid content of the HC layer-forming curable composition is 100% by mass. Furthermore, an "alicyclic epoxy group" refers to a monovalent functional group having a cyclic structure formed by condensing an epoxy ring with a saturated hydrocarbon ring.

[0410] Hereinafter, various components (polymerizable compounds and polymerization initiators) that can be contained in the curable composition for forming the HC layer of the second embodiment, preferably the second embodiment (1) or the second embodiment (2) will be described in more detail.

[0411] -Polymerizable compound-

[0412] (B) Radically polymerizable compound

[0413] The HC layer-forming curable composition of the second embodiment contains at least one radical polymerizable compound (B).

[0414] As a free radical polymerizable compound (B), any compound having a polymerizable group capable of free radical polymerization (free radical polymerizable group) can be used without any limitation. Furthermore, the number of free radical polymerizable groups contained in one molecule only needs to be at least one. That is, the free radical polymerizable compound (B) can be a monofunctional compound containing one free radical polymerizable group in one molecule, or a polyfunctional compound containing two or more free radical polymerizable groups. The number of free radical polymerizable groups contained in the polyfunctional compound is not particularly limited, and for example, it is 2 to 6 in one molecule. Furthermore, the two or more free radical polymerizable groups contained in one molecule of the polyfunctional compound may be the same, or may be two or more groups having different structures.

[0415] The radical polymerizable compound in the second embodiment (1) (hereinafter referred to as the radical polymerizable compound (b-1)) contains two or more radical polymerizable groups of at least one of acryloyl groups and methacryloyl groups in one molecule. The radical polymerizable compound (b-1) can contain, for example, preferably 2 to 10 radical polymerizable groups of at least one of acryloyl groups and methacryloyl groups in one molecule, and more preferably 2 to 6 radical polymerizable groups.

[0416] As the above-mentioned free radical polymerizable compound (B), a free radical polymerizable compound having a molecular weight of 200 or more and less than 1000 is preferred. In addition, in this specification, "molecular weight" refers to the weight average molecular weight measured by gel permeation chromatography (GPC) in terms of polystyrene for polymers. As an example of specific measurement conditions for the weight average molecular weight, the following measurement conditions can be cited.

[0417] GPC apparatus: HLC-8120 (manufactured by TOSOH CORPORATION)

[0418] Column: TSKgel Multipore HXL-M (manufactured by TOSOH CORPORATION, inner diameter 7.8 mm × column length 30.0 cm)

[0419] Eluent: tetrahydrofuran

[0420] As described above, the radical polymerizable compound (b-1) preferably contains one or more carbamate bonds in one molecule. The number of carbamate bonds contained in one molecule of the radical polymerizable compound (b-1) is preferably one or more, more preferably two or more, further preferably 2 to 5, for example, it can be set to two. In addition, in the radical polymerizable compound (b-1) containing two carbamate bonds in one molecule, at least one radical polymerizable group of the acryloyl group and the methacryloyl group may be bonded to only one of the carbamate bonds directly or via a linking group, or may be bonded to each of the two carbamate bonds directly or via a linking group. In one embodiment, it is preferred that at least one radical polymerizable group of the acryloyl group and the methacryloyl group is bonded to each of the two carbamate bonds bonded via a linking group.

[0421] In more detail, in the above-mentioned free radical polymerizable compound (b-1), the carbamate bond and at least one free radical polymerizable group of the acryloyl group and the methacryloyl group may be directly bonded, or a connecting group may be present between the carbamate bond and at least one free radical polymerizable group of the acryloyl group and the methacryloyl group. As the connecting group, there is no particular limitation, and examples thereof include any one of a straight chain and a branched chain and any one of a saturated and an unsaturated group, a hydrocarbon group and a cyclic group, and a group formed by combining two or more of them. The number of carbon atoms of the above-mentioned hydrocarbon group is, for example, about 2 to 20, but is not particularly limited. In addition, as a cyclic structure contained in the cyclic group, as an example, an aliphatic ring (cyclohexane ring, etc.) and an aromatic ring (benzene ring, naphthalene ring, etc.) can be mentioned. The above-mentioned group may be an unsubstituted group or may have a substituent. In addition, in this specification, unless otherwise specified, the group described may have a substituent or may be unsubstituted. When a certain group has a substituent, examples of the substituent include an alkyl group (e.g., an alkyl group having 1 to 6 carbon atoms), a hydroxyl group, an alkoxy group (e.g., an alkoxy group having 1 to 6 carbon atoms), a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom), a cyano group, an amino group, a nitro group, an acyl group, and a carboxyl group.

[0422] The free radical polymerizable compound (b-1) described above can be synthesized using a known method. It can also be obtained as a commercial product. For example, as an example of a synthesis method, a method of reacting a hydroxyl-containing compound such as an alcohol, a polyol, and a hydroxyl-containing (meth) acrylic acid with an isocyanate, or a method of esterifying the carbamate compound obtained by the above reaction using (meth) acrylic acid as needed can be cited. In addition, "(meth) acrylic acid" refers to one or both of acrylic acid and methacrylic acid.

[0423] Commercially available products of the radically polymerizable compound (b-1) containing one or more urethane bonds in one molecule include the following commercially available products, but are not limited to these. For example, they are all product names, and examples include UA-306H, UA-306I, UA-306T, UA-510H, UF-8001G, UA-101I, UA-101T, AT-600, AH-600, AI-600, BPZA-66, and BPZA-100 manufactured by Kyoeisha Chemical Co., Ltd.; U-4HA, U-6HA, U-6LPA, UA-32P, U-15HA, and UA-1100H manufactured by Shin-Nakamura Chemical Co., Ltd.; and UV-1400B, UV-1700B, UV-1800B, and UV-1900B manufactured by The Nippon Synthetic Chemical Industry Co., Ltd. V-6300B, UV-7550B, UV-7600B, UV-7605B, UV-7610B, UV-7620EA, UV-7630B, UV-7640B, UV-6630B, UV-7000B, UV-7510B, UV-7461TE, UV-300 0B, Purple Light UV-3200B, Purple Light UV-3210EA, Purple Light UV-3310EA, Purple Light UV-3310B, Purple Light UV-3500BA, Purple Light UV-3520TL, Purple Light UV-3700B, Purple Light UV-6100B, Purple Light UV-6640B, Purple Light UV-2000B, Purple Light UV-2010B and Purple Light UV-2250EA. In addition, examples include UV-2750B manufactured by The Nippon SVi Thetic Chemical Industry Co., Ltd., UL-503LN manufactured by Kyoeisha Chemical Co., Ltd., UNIDIC17-806, UNIDIC17-813, UNIDIC V-4030 and UNIDIC V-4000BA manufactured by Dainippon Ink and Chemicals, Inc., EB-1290K manufactured by DAICEL-ALLNEXL T., and HI-COAPAU-2010 and HI-COAPAU-2020 manufactured by TOKUSHIKICO., Ltd.

[0424] Hereinafter, as specific examples of the radically polymerizable compound (b-1) containing one or more urethane bonds in one molecule, exemplified compounds A-1 to A-8 are shown, but the present invention is not limited to the following specific examples.

[0425] [Chemical Formula 1]

[0426]

[0427] [Chemical Formula 2]

[0428]

[0429] While the radically polymerizable compound (b-1) containing one or more urethane bonds per molecule has been described above, the radically polymerizable compound (b-1) containing two or more acryloyl groups and at least one methacryloyl group per molecule may not have a urethane bond. Furthermore, the curable composition for forming the HC layer of the second embodiment (1) may contain, in addition to the radically polymerizable compound (b-1) containing two or more acryloyl groups and at least one methacryloyl group per molecule, one or more radically polymerizable compounds other than the radically polymerizable compound.

[0430] Hereinafter, a radical polymerizable compound (b-1) containing at least one radical polymerizable group selected from two or more acryloyl groups and methacryloyl groups in one molecule and containing at least one urethane bond in one molecule will be described as a first radical polymerizable compound, and a radical polymerizable compound that does not belong to the first radical polymerizable compound will be described as a "second radical polymerizable compound". That is, as long as the second radical polymerizable compound does not belong to the first radical polymerizable compound, it may or may not have one or more urethane bonds in one molecule, and may or may not contain at least one radical polymerizable group selected from two or more acryloyl groups and methacryloyl groups in one molecule. When the first radical polymerizable compound and the second radical polymerizable compound are used simultaneously, their mass ratio is preferably first radical polymerizable compound / second radical polymerizable compound = 3 / 1 to 1 / 30, more preferably 2 / 1 to 1 / 20, and even more preferably 1 / 1 to 1 / 10.

[0431] The content of the radically polymerizable compound containing at least one radically polymerizable group selected from among two or more acryloyl groups and methacryloyl groups in one molecule (regardless of the presence or absence of a urethane bond) in the curable composition for forming the HC layer of the second embodiment (1) is preferably 30% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more, relative to 100% by mass of the total amount of the composition. Furthermore, the content of the radically polymerizable compound containing at least one radically polymerizable group selected from among two or more acryloyl groups and methacryloyl groups in one molecule (regardless of the presence or absence of a urethane bond) in the curable composition for forming the HC layer of the second embodiment (1) is preferably 98% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to 100% by mass of the total amount of the composition.

[0432] Furthermore, the content of the first radically polymerizable compound in the curable composition for forming an HC layer of the second embodiment (1) is preferably 30% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more, relative to 100% by mass of the total amount of the composition. On the other hand, the content of the first radically polymerizable compound is preferably 98% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to 100% by mass of the total amount of the composition.

[0433] In one embodiment, the second radical polymerizable compound is preferably a radical polymerizable compound containing two or more radical polymerizable groups in one molecule and having no carbamate bond. The radical polymerizable group contained in the second radical polymerizable compound is preferably an ethylenically unsaturated group, and in one embodiment, it is preferably a vinyl group. In another embodiment, the ethylenically unsaturated group is preferably at least one radical polymerizable group among acryloyl and methacryloyl. That is, the second radical polymerizable compound also preferably has at least one radical polymerizable group among one or more acryloyl and methacryloyl groups in one molecule and has no carbamate bond. Furthermore, the second radical polymerizable compound, as a radical polymerizable compound, can also contain at least one radical polymerizable group among one or more acryloyl and methacryloyl groups and one or more radical polymerizable groups other than these in one molecule.

[0434] The number of radically polymerizable groups contained in one molecule of the second radically polymerizable compound is preferably at least two, more preferably three or more, and even more preferably four or more. Furthermore, in one embodiment, the number of radically polymerizable groups contained in one molecule of the second radically polymerizable compound is, for example, 10 or less, but may also be greater than 10. Furthermore, the second radically polymerizable compound preferably has a molecular weight of 200 or more and less than 1000.

[0435] Examples of the second radical polymerizable compound include the following compounds. However, the present invention is not limited to the following exemplary compounds.

[0436] For example, polyethylene glycol 200 di(meth)acrylate, polyethylene glycol 300 di(meth)acrylate, polyethylene glycol 400 di(meth)acrylate, polyethylene glycol 600 di(meth)acrylate, triethylene glycol di(meth)acrylate, epichlorohydrin-modified ethylene glycol di(meth)acrylate (commercially available products include DENACOLDA-811 manufactured by NAGASE & CO., LTD.), polypropylene glycol 200 di(meth)acrylate, polypropylene glycol 400 di(meth)acrylate, polypropylene glycol 700 di(meth)acrylate, ethylene oxide (EO) / propylene oxide (PO) block polyether di(meth)acrylate (commercially available products include BREMMERPET series manufactured by NOFCORPORATION), dipropylene glycol di(meth)acrylate, bisphenol AEO addition type di(meth)acrylate, and the like. Ester (commercially available products include M-210 manufactured by TOAGOSEI Co., Ltd. and NKEster A-BPE-20 manufactured by Shin-Nakamura Chemical Co., Ltd.), hydrogenated bisphenol AEO addition type di(meth)acrylate (commercially available products include NKEster A-HPE-4 manufactured by Shin-Nakamura Chemical Co., Ltd.), bisphenol APO addition type di(meth)acrylate (commercially available products include LIGHTACRYLATE BP-4PA manufactured by Kyoeisha Chemical Co., Ltd.), bisphenol A epichlorohydrin addition type di(meth)acrylate (commercially available products include Evecryl 150 manufactured by DAICEL-ALLNEXL T.), bisphenol AEO·PO addition type di(meth)acrylate (commercially available products include In BP-023-PE manufactured by Tostry Co., Ltd., etc.), bisphenol FEO addition type di(meth)acrylate (commercially available products, such as Aronix M-208 manufactured by Toagosei Co., Ltd., etc.), 1,6-hexanediol di(meth)acrylate and its epichlorohydrin modified products, neopentyl glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate and its caprolactone modified products, 1,4-butanediol di(meth)acrylate ) acrylate, 1,9-nonanediol di(meth)acrylate, trimethylolpropane di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, pentaerythritol di(meth)acrylate monostearate, trimethylolpropane acrylate benzoate, and isocyanuric acid EO-modified di(meth)acrylate (commercially available products, such as Aronix M-215 manufactured by TOAGOSEI Co., Ltd.).

[0437] In addition, trimethylolpropane tri(meth)acrylate and its EO, PO or epichlorohydrin modified products, pentaerythritol tri(meth)acrylate, glycerol tri(meth)acrylate and its EO, PO or epichlorohydrin modified products, isocyanuric acid EO-modified tri(meth)acrylate (commercially available products include Aronix M-315 manufactured by TOAGOSEICo., Ltd.), tri(meth)acryloyloxyethyl phosphate, [2,2,2-tri(meth)acryloyloxymethyl]ethyl-hydrogen phthalate, glycerol tri(meth)acrylate and its EO, PO or epichlorohydrin modified products, and the like. tetrafunctional (meth)acrylate compounds such as pentaerythritol tetra(meth)acrylate and its EO, PO or epichlorohydrin modified products, di-trimethylolpropane tetra(meth)acrylate; pentafunctional (meth)acrylate compounds such as dipentaerythritol penta(meth)acrylate and its EO, PO, epichlorohydrin, fatty acid or alkyl modified products; hexafunctional (meth)acrylates such as dipentaerythritol hexa(meth)acrylate and its EO, PO, epichlorohydrin, fatty acid or alkyl modified products, sorbitol hexa(meth)acrylate and its EO, PO, epichlorohydrin, fatty acid or alkyl modified products.

[0438] Two or more second radical polymerizable compounds may be used simultaneously. In this case, a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, "DPHA" (manufactured by Nippon Kaya ku Co., Ltd.), or the like can be preferably used.

[0439] Furthermore, as the second radically polymerizable compound, polyester (meth)acrylate or epoxy (meth)acrylate having a weight average molecular weight of 200 or more and less than 1000 is also preferred. Examples of commercially available polyester (meth)acrylates include BEAMSET 700 series products manufactured by Arakawa Chemical Industries, Ltd., such as BEAMSET 700 (hexafunctional), BEAMSET 710 (tetrafunctional), and BEAMSET 720 (trifunctional). In addition, examples of epoxy (meth)acrylates include SP series manufactured by SHOWADENKOK.K., such as SP-1506, 500, SP-1507, and 480; VR series manufactured by SHOWADENKOK.K., such as VR-77; and EA-1010 / ECA, EA-11020, EA-1025, and EA-6310 / ECA manufactured by Shin-Nakamura Chemical Co., Ltd.

[0440] Furthermore, specific examples of the second radically polymerizable compound include the compounds A-9 to A-11 described below.

[0441] [Chemical Formula 3]

[0442]

[0443] The curable composition for forming an HC layer of the second embodiment (2) contains a radically polymerizable compound (b-2) having three or more ethylenically unsaturated groups per molecule. Hereinafter, the compound (b-2) having three or more ethylenically unsaturated groups per molecule is also referred to as "component (b-2)."

[0444] Component (b-2) includes esters of polyols and (meth)acrylic acid, vinylbenzene and its derivatives, vinyl sulfone, and (meth)acrylamide. Among these, preferred are radically polymerizable compounds containing at least one radically polymerizable group of three or more acryloyl groups and methacryloyl groups in one molecule. Specific examples include esters of polyols and (meth)acrylic acid, which contain three or more ethylenically unsaturated groups in one molecule. More specifically, for example, (di)pentaerythritol tetra(meth)acrylate, (di)pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, EO-modified phosphoric acid tri(meth)acrylate, trimethylolethane tri(meth)acrylate, bis-trimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, (di)pentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, pentaerythritol hexa(meth)acrylate, 1,2,3-cyclohexane tetramethacrylate, polyurethane polyacrylate, polyester polyacrylate, caprolactone-modified tris(acryloyloxyethyl)isocyanurate, tripentaerythritol triacrylate, tripentaerythritol hexatriacrylate, 1,2,4-cyclohexane tetra(meth)acrylate, and pentaglycerol triacrylate. In addition, the above-mentioned "(di)pentaerythritol" is used to mean one or both of pentaerythritol and dipentaerythritol.

[0445] Furthermore, a resin containing three or more acryloyl groups and at least one radical polymerizable group among methacryloyl groups in one molecule is also preferred.

[0446] Examples of resins containing at least one free radical polymerizable group of three or more acryloyl groups and methacryloyl groups in one molecule include polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polymers of polyfunctional compounds such as polyols.

[0447] Specific examples of the radically polymerizable compound containing three or more acryloyl groups and at least one radically polymerizable group of methacryloyl groups in one molecule include the compounds exemplified in paragraph 0096 of JP-A-2007-256844.

[0448] Moreover, specific examples of free radical polymerizable compounds containing at least one free radical polymerizable group of three or more acryloyl groups and methacryloyl groups in one molecule include KAYARAD D PHA, KAYARAD D PHA-2C, KAYARAD PET-30, KAYARAD TMPTA, KAYARAD TPA-320, KAYARAD TPA-330, KAYARAD RP-1040, KAYARAD T-1420, KAYARAD D-310, KAYARAD D PCA-20, KAYARAD D PCA-30, KAYARAD D PCA-60 and KAYARAD GPO-303 manufactured by Nippon Kayaku Co., Ltd.; and esters of polyols and (meth) acrylic acid such as V#400 and V#36095D manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.In addition, violet UV-1400B, violet UV-1700B, violet UV-6300B, violet UV-7550B, violet UV-7600B, violet UV-7605B, violet UV-7610B, violet UV-7620EA, violet UV-7630B, violet UV-7640B, violet UV-6630B, violet UV-7000B, violet UV-7510B, violet UV-7461TE, violet UV-3000B, violet UV-3200B, violet UV-3210EA, violet UV-7620EA, violet UV-7630B, violet UV-7640B, violet UV-6630B, violet UV-7000B, violet UV-7510B, violet UV-7461TE, violet UV-3000B, violet UV-3200B, violet UV-3210EA, violet UV-7620EA UV-3310EA, UV-3310B, UV-3500BA, UV-3520TL, UV-3700B, UV-6100B, UV-6640B, UV-2000B, UV-2010B, UV-2250EA and UV-2750B (all manufactured by The Nippon Synthetic Chemical Industry Co., Ltd.), UL-503LN (manufactured by Kyoeisha Chemical Co., Ltd. ), UNIDIC17-806, UNIDIC17-813, UNIDIC V-4030 and UNIDIC V-4000BA (all manufactured by Dainippon Ink and Chemicals, Inc.), EB-1290K, EB-220, EB-5129, EB-1830 and EB-4358 (all manufactured by DAICEL-ALLNEXL T.), HI-COAPAU-2010 and HI-COAPAU-2020 (all manufactured by TOKUSHIKICO., Ltd. ), Aronix M-1960 (manufactured by TOAGOSEI Co., Ltd.), ArtResin UN-3320HA, UN-3320HC, UN-3320HS, UN-904, and HDP-4T, and trifunctional or higher-functional polyester compounds such as Aronix M-8100, M-8030, and M-9050 (all manufactured by TOAGOSEI Co., Ltd.) and KBM-8307 (manufactured by Daicel-Cytec Company, Ltd.). The above specific examples are all product names.

[0449] Furthermore, as the component (b-2), only one kind may be used, or two or more kinds having different structures may be used in combination.

[0450] As described above, the HC layer formed by curing the curable composition for forming an HC layer of the second embodiment (2) preferably contains, when the total solid content of the HC layer is 100% by mass, 15 to 70% by mass of the structure derived from (a-1), 25 to 80% by mass of the structure derived from (b-2), 0.1 to 10% by mass of the structure derived from (c), and 0.1 to 10% by mass of the structure derived from (d). When the total solid content of the HC layer is 100% by mass, the structure derived from (b-2) preferably accounts for 40 to 75% by mass, and more preferably 60 to 75% by mass. Furthermore, when the total solid content of the curable composition for forming an HC layer is 100% by mass, the curable composition for forming an HC layer of the second embodiment (2) preferably contains 40 to 75% by mass of the component (b-2), and more preferably 60 to 75% by mass.

[0451] (A) Cationic polymerizable compound

[0452] The HC layer-forming curable composition of the second embodiment contains at least one cationically polymerizable compound (A).

[0453] As a cationic polymerizable compound (A), any cationic polymerizable group (cationic polymerizable group) capable of cationic polymerization can be used without any restrictions. In addition, the number of cationic polymerizable groups contained in one molecule can be at least one. That is, the cationic polymerizable compound (A) can be a monofunctional compound containing one cationic polymerizable group in one molecule, or a polyfunctional compound containing two or more cationic polymerizable groups. The number of cationic polymerizable groups contained in the polyfunctional compound is not particularly limited, for example, it is 2 to 6 in one molecule. In addition, the two or more cationic polymerizable groups contained in one molecule of the polyfunctional compound can be the same, or can be two or more cationic polymerizable groups with different structures.

[0454] Furthermore, in one embodiment, the cationically polymerizable compound (A) preferably has one or more radical polymerizable groups in one molecule together with the cationically polymerizable group. Regarding the radical polymerizable groups that the above-mentioned cationically polymerizable compound (A) may have, reference can be made to the description of the radical polymerizable groups in the above-mentioned radical polymerizable compound (B). Preferably, it is an ethylenically unsaturated group, and the ethylenically unsaturated group is more preferably at least one radical polymerizable group selected from vinyl, acryloyl and methacryloyl. The number of radical polymerizable groups in one molecule of the cationically polymerizable compound having a radical polymerizable group is at least one, preferably 1 to 3, and more preferably one.

[0455] Preferred examples of the cationically polymerizable group include an oxygen-containing heterocyclic group and a vinyl ether group. The cationically polymerizable compound may contain one or more oxygen-containing heterocyclic groups and one or more vinyl ether groups in one molecule.

[0456] As the oxygen-containing heterocycle, it can be a monocycle or a condensed ring. In addition, an oxygen-containing heterocycle with a bicyclic skeleton is also preferred. The oxygen-containing heterocycle can be a non-aromatic ring or an aromatic ring, preferably a non-aromatic ring. As specific examples of monocycles, an epoxy ring (oxirane ring), a tetrahydrofuran ring, and an oxetane ring can be mentioned. In addition, as the oxygen-containing heterocycle with a bicyclic skeleton, an oxabicycle can be mentioned. In addition, a cationic polymerizable group containing an oxygen-containing heterocycle is included in the cationic polymerizable compound as a monovalent substituent or as a polyvalent substituent of more than two valencies. In addition, the above-mentioned condensed ring can be a condensed ring formed by condensing two or more oxygen-containing heterocycles, or a condensed ring formed by condensing one or more oxygen-containing heterocycles with one or more ring structures other than the above-mentioned oxygen-containing heterocycles. As ring structures other than the above-mentioned oxygen-containing heterocycles, it is not limited to these, and cycloalkane rings such as cyclohexane rings can be mentioned.

[0457] Specific examples of the oxygen-containing heterocycle are shown below, but the present invention is not limited to the following specific examples.

[0458] [Chemical Formula 4]

[0459]

[0460] The cationically polymerizable compound (A) may contain partial structures other than the cationically polymerizable group. Such partial structures are not particularly limited and may be linear, branched, or cyclic structures. These partial structures may contain one or more heteroatoms such as oxygen atoms and nitrogen atoms.

[0461] As a preferred embodiment of the cationic polymerizable compound (A), a compound containing a cyclic structure (a compound containing a cyclic structure) can be cited as a cationically polymerizable group or as a local structure other than a cationically polymerizable group. The number of cyclic structures contained in the compound containing a cyclic structure is, for example, one in one molecule, or it can be two or more, for example, 1 to 5, but is not particularly limited. A compound containing two or more cyclic structures in one molecule may contain the same cyclic structure or two or more cyclic structures having different structures.

[0462] An example of the cyclic structure contained in the cyclic structure-containing compound is an oxygen-containing heterocycle, the details of which are as described above.

[0463] The cationically polymerizable group equivalent (B / C), calculated by dividing the molecular weight (hereinafter referred to as "B") by the number of cationically polymerizable groups contained in one molecule of the cationically polymerizable compound (A) (hereinafter referred to as "C"), is, for example, 300 or less. From the perspective of improving the adhesion between the HC layer formed by curing the HC layer-forming curable composition and the resin film, it is preferably less than 150. On the other hand, from the perspective of improving the hygroscopicity of the HC layer formed by curing the HC layer-forming curable composition, the cationically polymerizable group equivalent is preferably 50 or greater. Furthermore, in one embodiment, the cationically polymerizable group contained in the cationically polymerizable compound from which the cationically polymerizable group equivalent is calculated may be an epoxy group (ethylene oxide ring). That is, in one embodiment, the cationically polymerizable compound (A) is a compound containing an epoxy group (ethylene oxide ring). From the perspective of improving the adhesion between the HC layer formed by curing the HC layer-forming curable composition and the resin film, the epoxy group (ethylene oxide ring)-containing compound preferably has an epoxy equivalent weight (calculated by dividing the molecular weight by the number of epoxy groups (ethylene oxide rings) contained in one molecule) of less than 150. Furthermore, the epoxy equivalent weight of the epoxy group (ethylene oxide ring)-containing compound is, for example, 50 or greater.

[0464] Furthermore, the molecular weight of the cationically polymerizable compound (A) is preferably 500 or less, more preferably 300 or less. A cationically polymerizable compound having a molecular weight within the above range tends to easily permeate the resin film and is presumably able to contribute to improved adhesion between the HC layer formed by curing the HC layer-forming curable composition and the resin film.

[0465] The curable composition for forming an HC layer of the second embodiment (2) contains an alicyclic epoxy group and an ethylenically unsaturated group (a-1), wherein the number of the alicyclic epoxy group contained in one molecule is one, the number of the ethylenically unsaturated group contained in one molecule is one, and the composition contains a cationically polymerizable compound having a molecular weight of 300 or less. Hereinafter, the cationically polymerizable compound (a-1) is referred to as "component (a-1)."

[0466] Examples of the ethylenically unsaturated group include free radical polymerizable groups such as acryloyl, methacryloyl, vinyl, styryl, and allyl groups. Among these, acryloyl, methacryloyl, or C(═O)OCH═CH2 is preferred, and acryloyl or methacryloyl is more preferred. The number of alicyclic epoxy groups and ethylenically unsaturated groups per molecule is preferably one each.

[0467] The molecular weight of the component (a-1) is 300 or less, preferably 210 or less, and more preferably 200 or less.

[0468] As a preferred embodiment of the component (a-1), a compound represented by the following general formula (1) can be mentioned.

[0469] [Chemical Formula 5]

[0470]

[0471] In the general formula (1), ring R represents a monocyclic hydrocarbon or a cross-linked hydrocarbon, L represents a single bond or a divalent linking group, and Q represents an ethylenically unsaturated group. Ring R refers to a ring having at least two carbon atoms and R constituting the oxirane ring in the above formula (1) as ring-constituting atoms.

[0472] When R in the general formula (1) is a monocyclic hydrocarbon, the monocyclic hydrocarbon is preferably an alicyclic hydrocarbon, more preferably an alicyclic hydrocarbon having 4 to 10 carbon atoms, further preferably an alicyclic hydrocarbon having 5 to 7 carbon atoms, and particularly preferably an alicyclic hydrocarbon having 6 carbon atoms. Preferred specific examples include cyclobutyl (cyclobutane), cyclopentyl (cyclopentane), cyclohexyl (cyclohexane), and cycloheptyl (cycloheptane), with cyclohexyl (cyclohexane) being more preferred.

[0473] When R in the general formula (1) is a cross-linked hydrocarbon, the cross-linked hydrocarbon is preferably a bicyclic cross-linked hydrocarbon (bicyclic) or a tricyclic cross-linked hydrocarbon (tricyclic). Specific examples include cross-linked hydrocarbons having 5 to 20 carbon atoms, such as norbornyl (norbornane), bornyl (bornane), isobornyl (isobornane), tricyclodecanyl (tricyclodecane), dicyclopentenyl (dicyclopentene), dicyclopentyl (dicyclopentane), tricyclopentenyl (tricyclopentene), tricyclopentyl (tricyclopentane), adamantyl (adamantane), and lower (e.g., 1 to 6 carbon atoms) alkyl-substituted adamantyl (adamantane).

[0474] When L represents a divalent linking group, the divalent linking group is preferably a divalent aliphatic hydrocarbon group. The number of carbon atoms in the divalent aliphatic hydrocarbon group is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1. The divalent aliphatic hydrocarbon group is preferably a linear, branched, or cyclic alkylene group, more preferably a linear or branched alkylene group, and even more preferably a linear alkylene group.

[0475] Examples of Q include ethylenically unsaturated groups such as acryloyl, methacryloyl, vinyl, styryl, and allyl. Among these, acryloyl, methacryloyl, or C(═O)OCH═CH 2 is preferred, and acryloyl or methacryloyl is more preferred.

[0476] Specific examples of the component (a-1) include various compounds exemplified in paragraph 0015 of Japanese Patent Application Laid-Open No. 10-017614, compounds represented by the following general formula (1A) or (1B), and 1,2-epoxy-4-vinylcyclohexane. Among these, compounds represented by the following general formula (1A) or (1B) are more preferred. Furthermore, compounds represented by the following general formula (1A) are preferably isomers thereof.

[0477] [Chemical Formula 6]

[0478]

[0479] [Chemical Formula 7]

[0480]

[0481] In the general formulae (1A) and (1B), R1 represents a hydrogen atom or a methyl group, and L2 represents a divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms.

[0482] The number of carbon atoms in the divalent aliphatic hydrocarbon group represented by L2 in general formulae (1A) and (1B) is 1 to 6, more preferably 1 to 3, and even more preferably 1. The divalent aliphatic hydrocarbon group is preferably a linear, branched, or cyclic alkylene group, more preferably a linear or branched alkylene group, and even more preferably a linear alkylene group.

[0483] The HC layer formed by curing the curable composition for forming an HC layer of the second embodiment (2) preferably contains 15 to 70% by mass of the structure derived from the above-mentioned component (a-1), more preferably 18 to 50% by mass, and even more preferably 22 to 40% by mass, based on 100% by mass of the total solid content of the HC layer. Furthermore, the curable composition for forming an HC layer of the second embodiment (2) preferably contains 15 to 70% by mass of the component (a-1), more preferably 18 to 50% by mass, and even more preferably 22 to 40% by mass of the component (a-1), based on 100% by mass of the total solid content of the curable composition for forming the HC layer.

[0484] Another example of a cyclic structure contained in the aforementioned cyclic structure-containing compound is a nitrogen-containing heterocycle. From the perspective of improving the adhesion between the HC layer formed by curing the HC layer-forming curable composition and the resin film, compounds containing nitrogen-containing heterocycles are preferred cationically polymerizable compounds. Compounds containing nitrogen-containing heterocycles preferably contain at least one nitrogen-containing heterocycle per molecule, either an isocyanurate ring (nitrogen-containing heterocycles contained in Exemplary Compounds B-1 to B-3, described below) or a glycoluril ring (nitrogen-containing heterocycle contained in Exemplary Compound B-10, described below). Among these, compounds containing an isocyanurate ring (isocyanurate ring-containing compound) are even more preferred cationically polymerizable compounds from the perspective of improving the adhesion between the HC layer formed by curing the HC layer-forming curable composition and the resin film. The present inventors presume that this is because the isocyanurate ring has excellent affinity with the resin constituting the resin film. From this point of view, a resin film including an acrylic resin film is more preferred, and the surface that directly contacts the HC layer formed by curing the HC layer-forming curable composition is further preferably an acrylic resin film surface.

[0485] Furthermore, as another example of the cyclic structure contained in the above-mentioned cyclic structure-containing compound, an alicyclic structure can be cited. Alicyclic structures include, for example, cyclocyclic, bicyclic, and tricyclic structures, and specific examples include dicyclopentyl ring and cyclohexane ring.

[0486] The cationically polymerizable compounds described above can be synthesized by known methods and are also available as commercial products.

[0487] Specific examples of the cationic polymerizable compound (A) containing an oxygen-containing heterocyclic ring (group) include 3,4-epoxycyclohexyl methyl methacrylate (commercially available products such as CYCLOMERM 100 manufactured by Daicel Corporation), 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate (for example, UVR6105 and UVR6110 manufactured by Union Carbide Corporation and CELLOXIDE 2021 manufactured by Daicel Chemical Industries, Ltd.), bis(3,4-epoxycyclohexylmethyl)adipate (for example, UVR6128 manufactured by Union Carbide Corporation), vinylcyclohexenyl monoepoxide (for example, CELLOXIDE 2000 manufactured by Daicel Chemical Industries, Ltd.), ε-caprolactone-modified 3,4-epoxycyclohexyl methyl methacrylate (commercially available products such as CYCLOMERM 100 manufactured by Daicel Corporation), 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate (for example, UVR6105 and UVR6110 manufactured by Union Carbide Corporation and CELLOXIDE 2021 manufactured by Daicel Chemical Industries, Ltd.), bis(3,4-epoxycyclohexylmethyl)adipate (for example, UVR6128 manufactured by Union Carbide Corporation), vinylcyclohexenyl monoepoxide (for example, CELLOXIDE 2000 manufactured by Daicel Chemical Industries, Ltd.), Cyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate (e.g., CELLOXIDE 2081 manufactured by DAICEL CHEMICAL INDUSTRIES, LTD.), 1-methyl-4-(2-methyloxiranyl)-7-oxabicyclo[4,1,0]heptane (e.g., CELLOXIDE 3000 manufactured by DAICEL CHEMICAL INDUSTRIES, LTD.), 7,7'-dioxa-3,3'-bis[bicyclo[ 4.1.0]heptane] (for example, CELLOXIDE 8000 manufactured by DAICEL CHEMICAL INDUSTRIES, LTD.), 3-ethyl-3-hydroxymethyloxetane, 1,4-bis{[(3-ethyl-3-oxetanyl)methoxy]methyl}benzene, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane and di[1-ethyl(3-oxetanyl)]methyl ether, etc.

[0488] Specific examples of the cationically polymerizable compound (A) containing a vinyl ether group as a cationically polymerizable group include 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether, nonanediol divinyl ether, cyclohexanediol divinyl ether, cyclohexanedimethanol divinyl ether, triethylene glycol divinyl ether, trimethylolpropane trivinyl ether, and pentaerythritol tetravinyl ether. The cationically polymerizable compound containing a vinyl ether group also preferably has an alicyclic structure.

[0489] Furthermore, as the cationically polymerizable compound (A), compounds exemplified in JP-A-8-143806, JP-A-8-283320, JP-A-2000-186079, JP-A-2000-327672, JP-A-2004-315778, and JP-A-2005-029632 can also be used.

[0490] Hereinafter, although example compounds B-1 to B-14 are shown as specific examples of the cationically polymerizable compound (A), the present invention is not limited to the following specific examples.

[0491] [Chemical Formula 8]

[0492]

[0493] [Chemical Formula 9]

[0494]

[0495] [Chemical Formula 10]

[0496]

[0497] Furthermore, from the perspective of improving the adhesion between the HC layer formed by curing the HC layer-forming curable composition and the resin film, preferred embodiments of the HC layer-forming curable composition include the following embodiments (1) to (4). It is more preferred that one or more of the following embodiments be satisfied, further preferably two or more, further preferably three or more, and further preferably all of them be satisfied. Furthermore, it is also preferred that a single cationically polymerizable compound satisfy multiple embodiments. For example, a preferred embodiment includes a compound containing a nitrogen-containing heterocycle having a cationically polymerizable group equivalent weight of less than 150.

[0498] (1) The cationically polymerizable compound includes a compound containing a nitrogen-containing heterocyclic ring. Preferably, the nitrogen-containing heterocyclic ring of the compound containing a nitrogen-containing heterocyclic ring is at least one of an isocyanurate ring and a glycoluril ring. More preferably, the compound containing a nitrogen-containing heterocyclic ring is an isocyanurate ring-containing compound. Further preferably, the isocyanurate ring-containing compound is an epoxy ring-containing compound containing one or more epoxy rings in one molecule.

[0499] (2) As the cationically polymerizable compound, a cationically polymerizable compound having a cationically polymerizable group equivalent weight of less than 150 is contained. Preferably, an epoxy group-containing compound having an epoxy group equivalent weight of less than 150 is contained.

[0500] (3) The cationically polymerizable compound contains an ethylenically unsaturated group.

[0501] (4) An oxetane ring-containing compound containing one or more oxetane rings in one molecule together with other cationically polymerizable compounds. The oxetane ring-containing compound preferably does not contain a nitrogen-containing heterocycle.

[0502] The content of the cationically polymerizable compound (A) in the HC layer-forming curable composition is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and even more preferably 20 parts by mass or more, relative to 100 parts by mass of the total content of the radically polymerizable compound (B) and the cationically polymerizable compound (A). Furthermore, the content of the cationically polymerizable compound (A) in the HC layer-forming curable composition is preferably 50 parts by mass or less, relative to 100 parts by mass of the total content of the radically polymerizable compound (B) and the cationically polymerizable compound (A).

[0503] Furthermore, the content of the cationically polymerizable compound (A) in the curable composition for forming the HC layer is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 1 part by mass or more, relative to 100 parts by mass of the total content of the first radically polymerizable compound and the cationically polymerizable compound (A). On the other hand, the content of the cationically polymerizable compound (A) is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, relative to 100 parts by mass of the total content of the first radically polymerizable compound and the cationically polymerizable compound (A).

[0504] In this specification, a compound having both a cationically polymerizable group and a radically polymerizable group is classified as a cationically polymerizable compound (A), and the content in the HC layer-forming curable composition is also defined according to this classification.

[0505] -Polymerization initiator-

[0506] The curable composition for forming the HC layer preferably contains a polymerization initiator, more preferably a photopolymerization initiator. The curable composition for forming the HC layer containing the radically polymerizable compound (B) preferably contains a radical photopolymerization initiator, and the curable composition for forming the HC layer containing the cationically polymerizable compound (A) preferably contains a cationic photopolymerization initiator. A single radical photopolymerization initiator may be used, or two or more radical photopolymerization initiators having different structures may be used simultaneously. This also applies to the cationic photopolymerization initiator.

[0507] Hereinafter, each photopolymerization initiator will be described in order.

[0508] (i) Free radical photopolymerization initiator

[0509] As the free radical photopolymerization initiator, any free radical photopolymerization initiator that can generate free radicals as active species by light irradiation can be used without any limitation. Specific examples include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, benzyl dimethyl ketal, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone oligomers, and Acetophenones such as 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propane-1-one; oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyl oxime)] and ethyl ketone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetooxime); benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether; dibenzoin; Benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3',4,4'-tetrakis(tert-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzylmethane bromide and (4-benzoylbenzyl)trimethylammonium chloride; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethyl Thioxanthones such as 2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thioxanthone-9-one methochloride; acylphosphine oxides such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; etc. In addition, as auxiliary agents of free radical photopolymerization initiators, triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4-dimethylaminobenzoic acid ethyl, 4-dimethylaminobenzoic acid (n-butoxy)ethyl ester, 4-dimethylaminobenzoic acid isopentyl ester, 4-dimethylaminobenzoic acid 2-ethylhexyl ester, 2,4-diethylthioxanthone and 2,4-diisopropylthioxanthone can be used simultaneously.

[0510] The above-mentioned radical photopolymerization initiators and auxiliary agents can be synthesized by known methods and are also available as commercial products. Preferred examples of commercially available radical photopolymerization initiators include Irgacure (127, 651, 184, 819, 907, 1870 (CGI-403 / Irg184 = 7 / 3 mixed initiator), 500, 369, 1173, 2959, 4265, 4263, and OXE01) manufactured by BASF, KAYACURE (DETX-S, BP-100, BDMK, CTX, BMS, 2-EAQ, ABQ, CPTX, EPD, ITX, QTX, BTC, and MCA) manufactured by Nippon Kayaku Co., Ltd., and Esacure (KIP100F, KB1, EB3, BP, X33, KT046, KT37, KIP150, and TZT) manufactured by Sartomer Company, Inc.

[0511] The content of the radical photopolymerization initiator in the HC layer-forming curable composition can be appropriately adjusted within a range that allows the polymerization reaction (radical polymerization) of the radical polymerizable compound to proceed satisfactorily, and is not particularly limited. The content is, for example, 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the radical polymerizable compound contained in the HC layer-forming curable composition.

[0512] (ii) Cationic photopolymerization initiator

[0513] As a cationic photopolymerization initiator, as long as it is an initiator that can generate cations (acids) as active species by light irradiation, known cationic photopolymerization initiators can be used without any restriction. As a specific example, known sulfonium salts, ammonium salts, iodine salts (such as diaryl iodonium salts), triaryl sulfonium salts, diazonium salts and iminium salts can be cited. More specifically, for example, cationic photopolymerization initiators represented by formulas (25) to (28) shown in paragraphs 0050 to 0053 of Japanese Patent Publication No. 8-143806 and substances exemplified as cationic polymerization catalysts in paragraph 0020 of Japanese Patent Publication No. 8-283320 can be cited. In addition, cationic photopolymerization initiators can be synthesized using known methods and can also be obtained as commercially available products. As commercially available products, for example, CI-1370, CI-2064, CI-2397, CI-2624, CI-2639, CI-2734, CI-2758, CI-2823, CI-2855, and CI-5102 manufactured by Nipponsoda Co., Ltd.; PHOTOINITIATOR 2047 manufactured by Rhodia; UVI-6974 and UVI-6990 manufactured by Union Carbide Corporation; and CPI-10P manufactured by San-Apro Ltd. can be used.

[0514] As the cationic photopolymerization initiator, from the viewpoints of the sensitivity of the photopolymerization initiator to light, the stability of the compound, etc., diazonium salts, iodonium salts, sulfonium salts, or iminium salts are preferred. From the viewpoint of weather resistance, iodonium salts are most preferred.

[0515] Specific commercially available products of iodine salt-based cationic photopolymerization initiators include, for example, B2380 manufactured by Tokyo Chemical Co., Ltd., BBI-102 manufactured by Midori Kagaku Co., Ltd., WPI-113 manufactured by Wako Pure Chemical Industries, Ltd., WPI-124 manufactured by Wako Pure Chemical Industries, Ltd., WPI-169 manufactured by Wako Pure Chemical Industries, Ltd., WPI-170 manufactured by Wako Pure Chemical Industries, Ltd., and DTBPI-PFBS manufactured by Toyo Gosei Co., Ltd.

[0516] Furthermore, specific examples of the iodine salt compound that can be used as a cationic photopolymerization initiator include the following compounds PAG-1 and PAG-2.

[0517] [Chemical Formula 11]

[0518] Cationic photopolymerization initiator (iodine salt compound) PAG-1

[0519]

[0520] [Chemical Formula 12]

[0521] Cationic photopolymerization initiator (iodine salt compound) PAG-2

[0522]

[0523] The content of the cationic photopolymerization initiator in the HC layer-forming curable composition can be appropriately adjusted within a range that allows the polymerization reaction (cationic polymerization) of the cationically polymerizable compound to proceed satisfactorily, and is not particularly limited. The content is, for example, 0.1 to 200 parts by mass, preferably 1 to 150 parts by mass, and more preferably 2 to 100 parts by mass, relative to 100 parts by mass of the cationically polymerizable compound.

[0524] Examples of other photopolymerization initiators include those described in paragraphs 0052 to 0055 of JP-A-2009-204725, the contents of which are incorporated into the present invention.

[0525] -Components that can be optionally contained in the HC layer-forming curable composition-

[0526] The HC layer-forming curable composition contains at least one component curable by irradiation with active energy rays, a fluorine-containing compound, and a polysiloxane-containing compound, and may optionally contain at least one polymerization initiator, preferably at least one polymerization initiator.

[0527] Next, various components that can be arbitrarily contained in the curable composition for forming the HC layer will be described.

[0528] (i) Inorganic particles

[0529] The curable composition for forming the HC layer may contain inorganic particles having an average primary particle size of less than 2 μm. To improve the hardness of a front panel having an HC layer formed by curing the curable composition for forming the HC layer (and, in turn, to improve the hardness of a liquid crystal panel having such a front panel), the curable composition for forming the HC layer and the HC layer formed by curing the composition preferably contain inorganic particles having an average primary particle size of less than 2 μm. The average primary particle size of the inorganic particles is preferably 10 nm to 1 μm, more preferably 10 nm to 100 nm, and even more preferably 10 nm to 50 nm.

[0530] The average primary particle size of the inorganic particles and matte particles described below was determined by observing 100 randomly selected particles (primary particles) using a transmission electron microscope (magnification of 500,000 to 2,000,000). The average of these particle sizes was taken as the average primary particle size.

[0531] Examples of the inorganic particles include silica particles, titania particles, zirconia particles, and alumina particles, among which silica particles are preferred.

[0532] To improve affinity with the organic components contained in the curable composition for forming the HC layer, the surfaces of the inorganic particles are preferably treated with a surface modifier containing an organic chain segment. The surface modifier preferably contains, within the same molecule, a functional group capable of forming a bond with or adsorbing to the inorganic particles and a functional group with high affinity for the organic components. Preferred surface modifiers having functional groups capable of bonding with or adsorbing to inorganic particles include silane-based surface modifiers, surface modifiers of metal alkoxides such as aluminum, titanium, and zirconium, and surface modifiers having anionic groups such as phosphate, sulfate, sulfonic, and carboxylic acid groups. Examples of functional groups with high affinity for organic components include those having the same hydrophilicity / hydrophobicity as the organic components and those capable of chemically bonding with the organic components. Among these, functional groups capable of chemically bonding with the organic components are preferred, with ethylenically unsaturated groups or ring-opening polymerizable groups being more preferred.

[0533] Preferred inorganic particle surface modifiers are polymerizable compounds containing a metal alkoxide surface modifier or an anionic group and an ethylenically unsaturated group or a ring-opening polymerizable group within the same molecule. By using these surface modifiers to chemically bond the inorganic particles to the organic component, the crosslink density of the HC layer can be increased, thereby increasing the hardness of the front panel (and, consequently, the hardness of the liquid crystal panel including the front panel).

[0534] Specific examples of the surface modifier include the following compounds S-1 to S-8.

[0535] S-1HC=C(X)COOC3H6Si(OCH3)3

[0536] S-2H2C=C(X)COOC2H4OTi(OC2H5)3

[0537] S-3H2C=C(X)COOC2H4OCOC5H 10 OPO(OH)2

[0538] S-4(H2C=C(X)COOC2H4OCOC5H 10 O)2POOH

[0539] S-5H2C=C(X)COOC2H4OSO3H

[0540] S-6H2C=C(X)COO(C5H 10 COO)2H

[0541] S-7H2C=C(X)COOC5H l0 COOH

[0542] S-8CH2CH(O)CH2OC3H6Si(OCH3)3

[0543] (X represents a hydrogen atom or a methyl group)

[0544] The surface modification of inorganic particles based on a surface modifier is preferably carried out in a solution. When the inorganic particles are mechanically dispersed, the surface modifier can be present together, or the surface modifier can be added and stirred after the inorganic particles are mechanically dispersed, or the surface modification is carried out before the inorganic particles are mechanically dispersed (if necessary, heating or pH (power of hydrogen) change is performed after heating or drying), and then dispersed. As a solvent for dissolving the surface modifier, an organic solvent with high polarity is preferably used. Specifically, well-known solvents such as alcohols, ketones and esters can be mentioned.

[0545] The content of inorganic particles, based on the total solids content of the HC layer-forming curable composition being 100% by mass, is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. The lower limit of this content is not particularly limited and may be 0% by mass (the HC layer may contain no inorganic particles). However, if present, it is preferably 1% by mass or more, and more preferably 7% by mass or more. The primary particles of the inorganic particles may be spherical or non-spherical, but spherical is preferred. To further enhance hardness, the HC layer formed by curing the HC layer-forming curable composition is preferably present as non-spherical secondary particles or higher-order particles formed by connecting 2 to 10 spherical inorganic particles (primary particles).

[0546] Specific examples of inorganic particles include ELCOMV-8802 (spherical silica particles with an average primary particle size of 12 nm manufactured by JGC Catalysts and Chemicals Ltd.), ELCOMV-8803 (irregular silica particles manufactured by JGC Catalysts and Chemicals Ltd.), MIBK-SD (spherical silica particles with an average primary particle size of 10 to 20 nm manufactured by Nissan Chemical Corporation), MEK-AC-2140Z (spherical silica particles with an average primary particle size of 10 to 20 nm manufactured by Nissan Chemical Corporation), and ELCOMV-8803 (irregular silica particles manufactured by JGC Catalysts and Chemicals Ltd.). Examples of the preferred materials include MEK-AC-4130 (spherical silica particles with an average primary particle size of 45 nm manufactured by Nissan Chemical Corporation), MIBK-SD-L (spherical silica particles with an average primary particle size of 40 to 50 nm manufactured by Nissan Chemical Corporation), and MEK-AC-5140Z (spherical silica particles with an average primary particle size of 85 nm manufactured by Nissan Chemical Corporation). Among these, ELCOM V-8802 manufactured by JGC Catalysts and Chemicals Ltd. is preferred from the viewpoint of further improving hardness.

[0547] (ii) Matting particles

[0548] The curable composition for forming the HC layer may also contain matte particles. Matt particles are particles having an average primary particle size of 2 μm or greater. They may be inorganic particles, organic particles, or particles of a composite material of inorganic and organic materials. The matte particles may be spherical or non-spherical. The average primary particle size of the matte particles is preferably 2 to 20 μm, more preferably 4 to 14 μm, and even more preferably 6 to 10 μm.

[0549] Specific examples of matte particles include inorganic particles such as silica particles and TiO particles, and organic particles such as cross-linked acrylic particles, cross-linked acrylic-styrene particles, cross-linked styrene particles, melamine resin particles, and benzoguanamine resin particles. Among these, the matte particles are preferably organic particles, more preferably cross-linked acrylic particles, cross-linked acrylic-styrene particles, or cross-linked styrene particles.

[0550] The content of the matte particles per unit volume in the HC layer formed by curing the HC layer-forming curable composition is preferably 0.10 g / cm 3 More preferably, 0.10 g / cm 3 ~0.40g / cm 3, more preferably 0.10 g / cm 3 ~0.30g / cm 3 .

[0551] (iii) UV absorbers

[0552] The curable composition for forming the HC layer also preferably contains a UV absorber. Examples of UV absorbers include benzotriazole compounds and triazine compounds. Benzotriazole compounds are compounds having a benzotriazole ring. Specific examples include the various benzotriazole-based UV absorbers described in paragraph 0033 of JP-A-2013-111835. Triazine compounds are compounds having a triazine ring. Specific examples include the various triazine-based UV absorbers described in paragraph 0033 of JP-A-2013-111835. The content of the UV absorber in the HC layer is, for example, approximately 0.1 to 10 parts by mass per 100 parts by mass of the resin (polymer component) contained in the HC layer, but is not particularly limited. Regarding UV absorbers, reference can also be made to paragraph 0032 of JP-A-2013-111835. In this specification, ultraviolet light refers to light having a central emission wavelength in the wavelength range of 200 to 380 nm.

[0553] (iv) Leveling agent

[0554] The curable composition for forming the HC layer also preferably contains a leveling agent.

[0555] As a leveling agent, a fluorinated polymer is preferably used. For example, a fluorinated aliphatic group-containing polymer described in Patent No. 5175831 can be mentioned. In addition, among the fluorinated aliphatic group-containing polymers, as a component constituting the polymer, a fluorinated aliphatic group-containing polymer described in the same patent, wherein the content of the fluorinated aliphatic group-containing monomer represented by the general formula (1) is 50% by mass or less of the total polymerized units, can be used as a leveling agent.

[0556] Moreover, in addition to the above, a leveling agent described in (vi) other components described later may also be contained.

[0557] When the HC layer-forming curable composition contains a leveling agent, the content thereof is preferably 0.01 to 7% by mass, more preferably 0.05 to 5% by mass, and even more preferably 0.1 to 2% by mass, based on the solid content of the HC layer-forming curable composition.

[0558] The curable composition for forming the HC layer may contain only one type of leveling agent or two or more types. When containing two or more types, the total amount thereof is preferably within the above range.

[0559] (v) Solvent

[0560] The curable composition for forming the HC layer also preferably contains a solvent. The solvent is preferably an organic solvent, but a single organic solvent or a mixture of two or more organic solvents in any proportion may be used. Specific examples of organic solvents include alcohols such as methanol, ethanol, propanol, n-butanol, and isobutanol; ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; cellosolves such as ethyl cellosolve; aromatics such as toluene and xylene; glycol ethers such as propylene glycol monomethyl ether; acetates such as methyl acetate, ethyl acetate, and butyl acetate; and diacetone alcohol. Cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, or methyl acetate are preferred, and a mixture of at least two of cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, and methyl acetate in any proportion is more preferred. This configuration allows for an optical film with improved abrasion resistance, punchability, and adhesion.

[0561] The amount of solvent in the HC layer-forming curable composition can be appropriately adjusted within a range that ensures the coating suitability of the composition. For example, the amount of solvent can be 50 to 500 parts by mass, preferably 80 to 200 parts by mass, per 100 parts by mass of the total amount of the polymerizable compound and the photopolymerization initiator.

[0562] Furthermore, the total solid content in the HC layer-forming curable composition is preferably 10 to 90% by mass, more preferably 50 to 80% by mass, and particularly preferably 65 to 75% by mass.

[0563] (vi) Other ingredients

[0564] In addition to the above-mentioned components, the HC layer-forming curable composition may further contain one or more known additives in any amount. Examples of these additives include surface conditioners, leveling agents, polymerization inhibitors, and polyrotaxanes. For details, see, for example, paragraphs 0032 to 0034 of JP-A-2012-229412. However, the additives are not limited to these, and various additives commonly added to HC layer-forming curable compositions may be used.

[0565] The curable composition for forming the HC layer can be prepared by mixing the above-mentioned various components simultaneously or sequentially in any order. The preparation method is not particularly limited, and a known stirrer or the like can be used for the preparation.

[0566] 2) Laminated structure with more than 2 layers

[0567] The optical film of the present invention is also preferably Figure 1 The HC layer 2A in the embodiment includes at least a first HC layer and a second HC layer in this order from the resin film 1A side.

[0568] The first HC layer can be located on the surface of the resin film 1A, or with another layer interposed therebetween. Similarly, the second HC layer can be located on the surface of the first HC layer, or with another layer interposed therebetween. To improve adhesion between the first and second HC layers, it is preferred that the second HC layer be located on the surface of the first HC layer, i.e., the two layers be in contact at least partially across the film surface.

[0569] Furthermore, each of the first HC layer and the second HC layer may be one layer or two or more layers, preferably one layer.

[0570] Furthermore, as described in detail below, when the optical film of the present invention is used as a front plate of a touch panel or a front plate of a touch panel display, or as a protective film for a polarizer, it is preferable to arrange the optical film so that the second HC layer faces the front side (visual recognition side) of the image display element. In order to achieve excellent abrasion resistance and punchability of the optical film surface, it is preferable to arrange the second HC layer on the surface side of the optical film, particularly on the outermost surface.

[0571] <First HC Layer, Curable Composition for First HC Layer Formation>

[0572] The first HC layer used in the present invention is formed from a curable composition for forming a first HC layer.

[0573] The first HC layer-forming curable composition preferably contains a polymerizable compound 1 having a radical polymerizable group and a polymerizable compound 2 having a cation polymerizable group and a radical polymerizable group in the same molecule and being different from the polymerizable compound 1 .

[0574] (Polymerizable compound)

[0575] As the polymerizable compound 1, the description of the radical polymerizable compound (B) described above is preferably applied, and as the polymerizable compound 2, the description of the cationically polymerizable compound (a-1) component described above is preferably applied.

[0576] Furthermore, the first HC layer-forming curable composition may contain another polymerizable compound different from the polymerizable compound 1 and the polymerizable compound 2 .

[0577] The aforementioned other polymerizable compound is preferably a polymerizable compound having a cationically polymerizable group. The cationically polymerizable group has the same meaning as the cationically polymerizable group described in Polymerizable Compound 2 (i.e., the cationically polymerizable group in cationically polymerizable compound (a-1) cited in Polymerizable Compound 2), and the preferred range is also the same. In particular, in the present invention, the other polymerizable compound is preferably a compound containing a nitrogen-containing heterocycle that contains a cationically polymerizable group. The use of such a compound can more effectively improve the adhesion between the resin film and the first HC layer. Examples of the nitrogen-containing heterocycle include at least one of an isocyanurate ring (the nitrogen-containing heterocycle contained in Exemplary Compounds B-1 to B-3 described below) and a glycoluril ring (the nitrogen-containing heterocycle contained in Exemplary Compound B-10 described below), preferably an isocyanurate ring. The number of cationically polymerizable groups contained in the other polymerizable compound is preferably 1 to 10, and more preferably 2 to 5. Furthermore, when using a polymerizable compound having a cationic polymerizable group and a nitrogen-containing heterocyclic structure as the other polymerizable compound, the resin film bonded to the first HC layer is preferably an acrylic resin film. This configuration tends to further improve the adhesion between the resin film and the first HC layer.

[0578] Specific examples of other polymerizable compounds include the aforementioned exemplary compounds B-3 to B-9, but the present invention is not limited to the aforementioned specific examples.

[0579] (other)

[0580] Furthermore, the descriptions of the fluorine-containing compound, the polysiloxane-containing compound, the polymerization initiator, the inorganic particles, the matte particles, the ultraviolet absorber, the leveling agent, the solvent, and other components described above can be preferably applied.

[0581] In particular, the first HC layer-forming curable composition preferably contains a solvent.

[0582] <Second HC Layer, Curable Composition for Second HC Layer Formation>

[0583] The second HC layer used in the present invention is formed from a curable composition for forming a second HC layer.

[0584] The curable composition for forming the second HC layer preferably contains at least the active energy curable component, the polysiloxane-containing compound, and the fluorine-containing compound. As the active energy curable component, it is preferred to contain at least the radical polymerizable compound (B).

[0585] Furthermore, there are no particular limitations on the first and second HC layers and the curable composition for forming the HC layer, and the description of the aforementioned HC layer and the curable composition for forming the HC layer can be applied.

[0586] (Thickness of HC layer)

[0587] The thickness of the HC layer is preferably 3 μm or more and 100 μm or less, more preferably 5 μm or more and 70 μm or less, and even more preferably 10 μm or more and 50 μm or less.

[0588] (Pencil degree of HC layer)

[0589] The harder the pencil sharpness of the HC layer, the better. Specifically, it is preferably 3H or higher, more preferably 5H or higher, and even more preferably 7H or higher.

[0590] -Method for forming HC layer-

[0591] The HC layer can be formed by applying the curable composition for forming the HC layer directly or via another layer such as an adhesion layer onto a resin film and then irradiating the film with active energy rays. Coating can be performed using known coating methods such as dip coating, air knife coating, curtain coating, roll coating, die coating, wire rod coating, and gravure coating. Furthermore, the HC layer can be formed into a laminated structure of two or more layers (e.g., approximately two to five layers) by simultaneously or sequentially applying two or more compositions of different compositions.

[0592] The HC layer can be formed by irradiating the applied HC layer-forming curable composition with active energy rays. For example, when the HC layer-forming curable composition contains a radical polymerizable compound, a cationic polymerizable compound, a radical photopolymerization initiator, and a cationic photopolymerization initiator, the polymerization reaction of the radical polymerizable compound and the cationic polymerizable compound can be initiated by the action of the radical photopolymerization initiator and the cationic photopolymerization initiator, respectively. The wavelength of the irradiated light can be determined according to the type of polymerizable compound and polymerization initiator used. As light sources for light irradiation, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, chemical lamps, electrodeless discharge lamps, and LEDs (Light Emitting Diodes) that emit light in the wavelength band of 150 to 450 nm can be cited. In addition, the light irradiation amount is generally 30 to 3000 mJ / cm 2 , preferably 100 to 1500 mJ / cm 2 Before or after light irradiation, or both, a drying treatment may be performed as needed. Drying can be performed by blowing warm air, placing the composition in a heating furnace, or transporting the composition in a heating furnace. When the curable composition for forming the HC layer contains a solvent, the heating temperature can be set to a temperature that can dry and remove the solvent, and is not particularly limited. The heating temperature refers to the warm air temperature or the atmosphere temperature in the heating furnace.

[0593] Polarizing Plate

[0594] The polarizing plate of the present invention comprises at least a polarizing film (also referred to as a polarizer) and the optical film of the present invention, and may further comprise a retardation film on the side of the polarizing film not provided with the optical film of the present invention. The retardation film is not particularly limited, and a commonly used film can be used.

[0595] Furthermore, the polarizer of the present invention may have impact-absorbing layers disposed on both sides of the polarizing film. These impact-absorbing layers may be any impact-absorbing layers commonly used in polarizers, with the impact-absorbing layers in the optical film of the present invention being preferred. The polarizer of the present invention can further improve its impact absorption by having impact-absorbing layers disposed on both sides of the polarizing film.

[0596] In the polarizing plate of the present invention, examples of the structure of the polarizing plate comprising the optical film of the present invention and the impact-absorbing layer include, specifically, a polarizing plate comprising the optical film of the present invention, a polarizing film, and an impact-absorbing layer in this order; and a polarizing plate comprising the optical film of the present invention, a polarizing film, a resin film, and an impact-absorbing layer in this order.

[0597] In the polarizing plate of the present invention, the side of the optical film of the present invention on which the impact-absorbing layer is provided can be directly bonded to the polarizing film, or the side opposite to the impact-absorbing layer (i.e., the side on the resin film side) can be bonded thereto, or the impact-absorbing layer and the polarizing film can be bonded thereto with a resin film interposed between them.

[0598] During the lamination of the optical film and polarizing film, and the lamination of the impact-absorbing layer and polarizing film, an adhesive or pressure-sensitive adhesive may be used. Conventional adhesives or pressure-sensitive adhesives can be used. Furthermore, if the impact-absorbing layer is located on the lamination surface, lamination can also be performed through the impact-absorbing layer.

[0599] When the polarizer of the present invention is assembled on a liquid crystal panel, it is preferably used as either the front or rear polarizer. When used as a front polarizer, the optical film of the present invention may or may not have a hard coating layer, but preferably has a hard coating layer. When assembled on a liquid crystal panel, it is more preferably provided with a hard coating layer on the side closest to visual recognition. Furthermore, when used as a rear polarizer, the optical film of the present invention may or may not have a hard coating layer.

[0600] As a polarizing film (also referred to as a polarizer), iodine-based polarizing films, dye-based polarizing films using dichroic dyes, and polyene-based polarizing films can be cited. Iodine-based polarizing films and dye-based polarizing films can usually be manufactured using polyvinyl alcohol films. The protective film on the side of the polarizing film not provided with the optical film of the present invention is usually a resin film. The protective film can be exemplified by a cellulose acylate film.

[0601] (Brightness Enhancement Film)

[0602] The polarizer of the present invention may be provided with a brightness-enhancing film. The brightness-enhancing film is not particularly limited, and various known films may be used. Specifically, examples include the dielectric multilayer film described in Patent No. 04091978, DBEF (product name) manufactured by 3M, and APF-V3 and APF-V4 manufactured by 3M, all of which are product names. The brightness-enhancing film may be applied to the polarizer via an impact-absorbing layer or via an adhesive or pressure-sensitive adhesive. In this case, various known adhesives or pressure-sensitive adhesives may be used.

[0603] <<LCD Panel>>

[0604] The liquid crystal panel includes at least a liquid crystal cell and a polarizing plate. Preferably, the liquid crystal panel includes a front polarizing plate, a liquid crystal cell, and a rear polarizing plate.

[0605] In the liquid crystal panel of the present invention, it is preferred that at least one of the front polarizer and the rear polarizer be the polarizer of the present invention, and it is more preferred that both be the polarizers of the present invention. That is, the optical film on at least one of the front polarizer and the rear polarizer preferably has the aforementioned impact-absorbing layer, and it is more preferred that both the optical film on the front polarizer and the optical film on the rear polarizer have the aforementioned impact-absorbing layer.

[0606] In the front and rear polarizers, the relationship between the polarizing film and the impact-absorbing layer is not particularly limited. However, the front polarizer preferably includes the impact-absorbing layer on at least the visually visible side relative to the polarizing film of the front polarizer, and the rear polarizer preferably includes the impact-absorbing layer on at least the opposite visually visible side relative to the polarizing film of the front polarizer. It is believed that by having at least one of the front and rear polarizers having the above-described structure, the liquid crystal panel of the present invention can absorb and disperse external impacts, etc., and exhibits even better impact absorption.

[0607] Furthermore, by having at least one of the front polarizer and the rear polarizer have the aforementioned impact absorbing layer on both sides of the polarizing film, the impact absorption can be further improved. Therefore, from the perspective of improving the impact absorption, it is preferred that both the front polarizer and the rear polarizer have the aforementioned impact absorbing layer on both sides of the polarizing film.

[0608] When the above-mentioned impact absorbing layer is used in both the rear polarizer and the front polarizer as in the above-mentioned liquid crystal panel, these impact absorbing layers may be the same or different. In different cases, the impact absorbing layer is subjected to the conditions of 25°C and a frequency of 10 6 The storage modulus E' in Hz preferably satisfies the following formula.

[0609] E' f (Storage modulus E' of the impact absorbing layer of the front polarizer) - E' r(Storage modulus E' of the impact absorbing layer of the rear polarizer) ≥ 0

[0610] The liquid crystal panel of the present invention can further disperse the impact from the outside by satisfying the above formula. f -E' r The upper limit of the indicated value is not particularly limited.

[0611] The above impact absorbing layer is heated at 25℃ and 10 6 The storage modulus E' in Hz is a value measured by the method described in the section "Optical Film".

[0612] In the case where the rear polarizing plate has two or more optical films of the present invention, the storage elastic modulus of the impact absorbing layer located on the side opposite to the visual recognition side is used as E' in the above formula. r When the front polarizing plate has two or more optical films of the present invention, the storage modulus of the impact absorbing layer located closest to the visual recognition side is read as E' in the above formula.

[0613] The liquid crystal cell comprises at least a liquid crystal and two alignment films sandwiching the liquid crystal, and a glass substrate is typically disposed on the outer sides of the alignment films. The image display element of the liquid crystal panel of the present invention is not particularly limited as long as it is a liquid crystal display element. For example, a thin-film transistor liquid crystal display element can be mentioned. The liquid crystal display element can be the liquid crystal cell itself, or it can be configured as a touch sensor film or touch panel on one side of the liquid crystal cell, as in the case of the externally mounted touch panel described below.

[0614] The liquid crystal panel of the present invention is preferably a liquid crystal touch panel with a touch sensor (function). In this case, the liquid crystal display element is an in-cell touch panel display element or an out-cell touch panel display element. In-cell touch panel display elements and out-cell touch panel display elements are described in detail in the image display device described later.

[0615] When the liquid crystal panel of the present invention has the above-mentioned in-cell touch panel display element, the liquid crystal panel of the present invention includes at least the in-cell touch panel display element and a polarizer, preferably at least a front polarizer, an in-cell touch panel display element and a rear polarizer.

[0616] When the liquid crystal panel of the present invention has the above-mentioned external touch panel display element, the liquid crystal panel of the present invention includes at least an external touch panel display element with a touch sensor film and a polarizer, preferably includes at least a front polarizer, an external touch panel display element with a touch sensor film and a rear polarizer.

[0617] When laminating the polarizer of the present invention to a liquid crystal cell, etc., an adhesive or pressure-sensitive adhesive may be used. In this case, a conventional adhesive or pressure-sensitive adhesive may be used. In addition, when an impact-absorbing layer is located on the laminating surface, lamination may also be performed through the impact-absorbing layer.

[0618] In addition to the above description, regarding the constituent materials of the liquid crystal panel other than the polarizing plate, the structure of the liquid crystal panel, the method for forming the liquid crystal panel, etc. of the present invention, commonly used techniques can be applied without any limitation.

[0619] <<Image Display Device>>

[0620] The image display device having the optical film of the present invention is an image display device having the optical film of the present invention or the polarizing plate of the present invention (at least one of the front polarizing plate and the rear polarizing plate) and an image display element.

[0621] Examples of image display devices including the optical film of the present invention include liquid crystal displays (LCDs), plasma display panels, electroluminescent displays, cathode ray tube displays, and touch panel displays.

[0622] Preferred examples of the liquid crystal display device including the optical film of the present invention include an image display device including the liquid crystal panel of the present invention.

[0623] Examples of liquid crystal display devices include TN (Twisted Nematic) type, STN (Super-Twisted Nematic) type, TSTN (Triple Super Twisted Nematic) type, multi-domain type, VA (Vertical Alignment) type, IPS (In Plane Switching) type, and OCB (Optically Compensated Bend) type.

[0624] The image display device preferably has reduced brittleness, excellent handleability, no loss of display quality due to surface smoothness or wrinkles, and can reduce light leakage during a wet heat test.

[0625] That is, in the image display device having the optical film of the present invention, it is preferable that the image display element is a liquid crystal display element. As an image display device having a liquid crystal display element, Xperia P (product name) manufactured by Sony Ericsson Mobile Communications can be cited.

[0626] In the image display device having the optical film of the present invention, it is also preferable that the image display element is an organic electroluminescence (EL) display element.

[0627] The organic electroluminescent display element can be applied to a known technology without any limitation. As an image display device having an organic electroluminescent display element, GALAXYS II (product name) manufactured by SAMSUNG Corporation can be cited.

[0628] In the image display device having the optical film of the present invention, the image display element is preferably an in-cell touch panel display element. An in-cell touch panel display element is an element in which a touch panel function is built into the image display element unit.

[0629] The in-cell touch panel display element can apply known technologies such as those described in Japanese Patent Application Laid-Open No. 2011-076602 and Japanese Patent Application Laid-Open No. 2011-222009 without limitation. An example of an image display device having an in-cell touch panel display element is the Xperia P (product name) manufactured by Sony Ericsson Mobile Communications.

[0630] Furthermore, in the image display device having the optical film of the present invention, the image display element is preferably an on-cell touch panel display element. An on-cell touch panel display element is an element in which the touch panel function is arranged outside the image display element unit.

[0631] The on-cell touch panel display element can be applied to known technologies such as Japanese Patent Application Laid-Open No. 2012-88683 without limitation. An example of an image display device having an on-cell touch panel display element is GALAXYS II (product name) manufactured by SAMSUNG.

[0632] <<Touch Panel>>

[0633] A touch panel having the optical film of the present invention is a touch panel comprising a touch sensor film bonded to the optical film of the present invention. When the optical film of the present invention is used for a touch panel, the optical film of the present invention may or may not have an HC layer, but preferably has an HC layer, preferably on the resin film surface opposite to the surface having the HC layer (e.g., Figure 2 The touch sensor film is attached to the impact absorbing layer 2A surface).

[0634] The touch sensor film is not particularly limited, but is preferably a conductive film having a conductive layer formed thereon.

[0635] The conductive film is preferably a conductive film in which a conductive layer is formed on an arbitrary support.

[0636] As the liquid crystal panel of the present invention, a liquid crystal panel including the touch panel of the present invention is also preferably used.

[0637] The touch panel of the present invention can be preferably used as an add-on touch panel. An add-on touch panel refers to a touch panel that is attached to the visual recognition side of a liquid crystal panel. As the liquid crystal panel, a commonly used liquid crystal panel can be used without particular limitation. For example, the liquid crystal panel of the present invention described above can also be preferably used (however, liquid crystal panels having a touch sensor function are not included).

[0638] Furthermore, the touch panel of the present invention can also be preferably used as a touch panel in an external touch panel. In this case, the touch panel of the present invention can be used as an image display element provided on the surface of the visual recognition side of the external touch panel display element. As the image display element, a commonly used external touch panel or other image display element can be used without particular limitation, for example, the aforementioned external touch panel display element can be cited. Furthermore, at least one of the optical film of the present invention and the polarizer of the present invention can also be used in combination.

[0639] Example

[0640] The present invention is described in more detail below based on the following examples. However, the present invention is not to be construed as being limiting. In the following examples, unless otherwise specified, "parts" and "%" representing compositional values ​​are by mass. Furthermore, a "-" symbol in a table indicates that the component or structure in that column is absent, or that the storage modulus E' or tan δ is not measured.

[0641] <Example>

[0642] <<Production of Optical Film>>

[0643] [Example 1]

[0644] <1. Preparation of Resin Film 1>

[0645] (1) Preparation of core layer cellulose acylate doping solution

[0646] The following composition was placed in a mixing tank and stirred to prepare a core layer cellulose acylate dope.

[0647] ----------------------------

[0648] Core layer cellulose acylate doping solution

[0649] -------------------------

[0650] 100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.88 and a weight average molecular weight of 260,000

[0651] Phthalate oligomer A of the following structure: 10 parts by mass

[0652] 4 parts by mass of a compound (A-1) represented by the following formula I

[0653] 2.7 parts by mass of an ultraviolet absorber represented by the following formula II (manufactured by BASF)

[0654] Light stabilizer (manufactured by BASF, product name: TINUVIN 123) ... 0.18 parts by mass

[0655] N-Alkenylpropylenediaminetriacetic acid (manufactured by Nagase ChemteX Corporation, product name: TEKLANDO) 0.02 parts by mass

[0656] Dichloromethane (first solvent) 430 parts by mass

[0657] Methanol (second solvent) 64 parts by mass

[0658] ----------------------------

[0659] The compounds used are shown below.

[0660] Phthalate oligomer A (weight average molecular weight: 750)

[0661] [Chemical Formula 13]

[0662]

[0663] The compound (A-1) represented by the following formula I

[0664] Formula I:

[0665] [Chemical Formula 14]

[0666]

[0667] Ultraviolet absorber represented by formula II

[0668] Formula II:

[0669] [Chemical Formula 15]

[0670]

[0671] (2) Preparation of outer layer cellulose acylate doping solution

[0672] To 90 parts by mass of the core layer cellulose acylate dope was added 10 parts by mass of the following inorganic particle-containing composition to prepare an outer layer cellulose acylate dope.

[0673] -------------------------

[0674] Composition containing inorganic particles

[0675] --------------------------

[0676] Silica particles with an average primary particle size of 20 nm (manufactured by NIPPON AEROSIL CO., LTD., product name: AEROSIL R972) ... 2 parts by mass

[0677] Dichloromethane (first solvent) 76 parts by mass

[0678] Methanol (second solvent) 11 parts by mass

[0679] Core layer cellulose acylate doping liquid: 1 part by mass

[0680] --------------------------

[0681] (3) Preparation of resin film

[0682] The outer layer cellulose acylate dope, the core layer cellulose acylate dope and the outer layer cellulose acylate dope were simultaneously cast from a casting port onto a casting belt having a surface temperature of 20°C in such a manner that the outer layer cellulose acylate dope was arranged on both sides of the core layer cellulose acylate dope.

[0683] A stainless steel endless belt with a width of 2.1 m and a length of 70 m was used as the casting belt. The belt was polished to a thickness of 1.5 mm and a surface roughness of 0.05 μm or less. Made of SUS316, it possesses sufficient corrosion resistance and strength. The overall thickness variation of the belt was less than 0.5%.

[0684] On the resulting cast film, a rapid drying air stream at a speed of 8 m / s, a gas concentration of 16%, and a temperature of 60°C was blown onto the surface of the cast film to form an initial film. Subsequently, a drying air stream at 140°C was blown from the upstream side of the casting belt. Furthermore, drying air streams at 120°C and 60°C were blown from the downstream side.

[0685] After adjusting the residual solvent content to approximately 33% by mass, the film was peeled from the tape. Next, both ends of the resulting film in the width direction were fixed with tenter clips and then conveyed between rollers in a heat treatment apparatus for further drying, thereby producing a resin film 1 having a thickness of 100 μm (outer layer / core layer / outer layer = 3 μm / 94 μm / 3 μm).

[0686] [Saponification treatment]

[0687] The resin film 1 prepared above was immersed in a 1.5 mol / L aqueous NaOH solution (saponification solution) maintained at 55°C for 2 minutes, then rinsed with water. The film was then immersed in a 0.05 mol / L aqueous sulfuric acid solution at 25°C for 30 seconds, and then rinsed under running water for 30 seconds to neutralize the film. Dehydration with an air knife was repeated three times, and after water removal, the film was dried in a drying zone at 70°C for 15 seconds, thereby producing a saponified resin film 1.

[0688] <2. Preparation of shock absorbing layer>

[0689] (1) Preparation of the composition for forming the impact absorbing layer (SA layer)

[0690] The components were mixed in the formulations shown in Table 1 below, and the mixture was filtered through a polypropylene filter having a pore size of 10 μm to prepare compositions SA-1 to SA-8 for forming an impact-absorbing layer (SA layer).

[0691] [Table 1]

[0692]

[0693] The details of each compound described in Table 1 are shown below.

[0694] <Resin>

[0695] CLARITY LA4285: Product name, manufactured by KURARAY CO., LTD., PMMA-PnBA block copolymer elastomer

[0696] HYBRAR 5127: Product name, manufactured by KURARAY CO., LTD., unhydrogenated block copolymer elastomer of polystyrene and ethylene-polydiene

[0697] SEPTON 2063: Product name, manufactured by KURARAY CO., LTD., a block copolymer elastomer of polystyrene and ethylene propylene

[0698] HYBRAR 7311F: Product name, manufactured by KURARAY CO., LTD., hydrogenated type of polystyrene and vinyl-polydiene block copolymer elastomer

[0699] <Polymerizable Group-Containing Compound>

[0700] KURAPRENE UC-203M: Product name, manufactured by KURARAY CO., LTD., polyisoprene containing polymerizable groups

[0701] <Polymerization Initiator>

[0702] Irg184: 1-Hydroxy-cyclohexyl-phenyl-ketone (α-hydroxyalkyl phenone-based free radical photopolymerization initiator, manufactured by BASF, product name: IRGACURE 184)

[0703] <Additives>

[0704] KURAPRENE LBR-302: Product name, manufactured by KURARAY CO., LTD., liquid butadiene

[0705] Liquid paraffin: Made by FUJIFILM Wako Pure Chemical Corporation, reagent grade

[0706] <Solvent>

[0707] MIBK: Methyl isobutyl ketone

[0708] In Table 1 above, the total amount of the solid content and the solvent is described as 100 mass %. The solid content concentration in the composition represents the ratio of the solid content to the total amount of the solid content and the solvent.

[0709] (2) Preparation of impact absorbing layer

[0710] The SA layer-forming composition SA-1 was applied to the surface of the resin film 1 subjected to saponification treatment on the side opposite to the side in contact with the casting belt, and dried to form an SA layer.

[0711] The coating and drying methods are described in detail below. The SA layer-forming composition was applied using the slot die coating method described in Example 1 of Japanese Patent Application Laid-Open No. 2006-122889 at a conveying speed of 30 m / min to a film thickness of 80 μm after drying. The film was then dried at an ambient temperature of 60° C. for 150 seconds to produce the optical film of Example 1.

[0712] [Example 2]

[0713] SA-2 was used instead of the SA layer-forming composition SA-1, and after drying for 150 seconds at an ambient temperature of 60°C, the sample was irradiated with an illuminance of 300 mW / cm2 using an air-cooled metal halide lamp (manufactured by EYE GRAPHICS Co., Ltd.) with an oxygen concentration of approximately 0.1% by volume and a 160 W / cm2 intensity under nitrogen purge. 2 , irradiation dose 1200mJ / cm 2 An optical film of Example 2 was produced in the same manner as in Example 1, except that the applied SA layer-forming composition was cured by irradiating with ultraviolet rays.

[0714] [Example 3]

[0715] An optical film of Example 3 was produced in the same manner as in Example 1, except that SA-3 was used instead of the SA layer-forming composition SA-1.

[0716] [Example 4]

[0717] <1. Preparation of Resin Film 2>

[0718] A resin film 2 was produced in the same manner as in Example 1, except that the thickness of the resin film 1 was 140 μm (outer layer / core layer / outer layer=3 μm / 134 μm / 3 μm).

[0719] <2. Preparation of hard coating>

[0720] (1) Preparation of curable composition for forming hard coat layer (HC layer)

[0721] The components were mixed in the formulation shown in Table 2 below, and the mixture was filtered through a polypropylene filter having a pore size of 10 μm to prepare HC layer-forming curable compositions HC-1 and HC-2.

[0722] [Table 2]

[0723]

[0724] The unit of the numerical values ​​in Table 2 is mass %. In Table 2, the total amount of the solid content and the solvent is described as 100 mass %. The solid content concentration in the composition represents the ratio of the solid content to the total amount of the solid content and the solvent.

[0725] The details of each compound described in Table 2 are shown below.

[0726] <Polymerizable Compound>

[0727] DPHA: A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., product name: KAYARAD DPHA)

[0728] CYCLOMER M100: 3,4-epoxycyclohexyl methyl methacrylate (product name, manufactured by Daicel Corporation)

[0729] <Polymerization Initiator>

[0730] Irg184: 1-Hydroxy-cyclohexyl-phenyl-ketone (α-hydroxyalkyl phenone-based free radical photopolymerization initiator, manufactured by BASF, product name: IRGACURE 184)

[0731] PAG-1: Cationic photopolymerization initiator, which is the iodine salt compound shown below

[0732] [Chemical Formula 16]

[0733] Cationic photopolymerization initiator (iodine salt compound)

[0734]

[0735] <Fluorinated compounds>

[0736] RS-90: Made by DIC Corporation, a fluorinated antifouling agent with a radically polymerizable group

[0737] <Polysilicone-containing compound>

[0738] 8SS-723: Taisei Fine Chemical Co., Ltd., a polysiloxane antifouling agent having an acrylic group with a reactive group equivalent weight of 338 g / mol

[0739] <Leveling agent>

[0740] P-112: Leveling agent, compound P-112 described in paragraph 0053 of Japanese Patent No. 5175831

[0741] <Inorganic particles>

[0742] MEK-AC-2140Z: Made by Nissan Chemical Corporation, spherical silica particles with an average primary particle size of 10 to 20 nm

[0743] <Solvent>

[0744] MEK: Methyl Ethyl Ketone

[0745] MIBK: Methyl isobutyl ketone

[0746] (2) Preparation of HC layer

[0747] (i) Preparation of the first HC layer

[0748] On the side of the resin film 2 in contact with the casting belt, a curable composition HC-1 for forming an HC layer was applied and cured to form a first HC layer having a film thickness of 16 μm.

[0749] The coating and curing methods are described in detail below. The HC layer-forming curable composition was applied using the slot die coating method described in Example 1 of Japanese Patent Application Laid-Open No. 2006-122889 at a conveying speed of 30 m / min and dried for 150 seconds at an ambient temperature of 60°C. Subsequently, under nitrogen purge, the film was irradiated with an illuminance of 20 mW / cm² using an air-cooled metal halide lamp (manufactured by EYF GRAPHICS Co., Ltd.) with an oxygen concentration of approximately 0.1% by volume and a 160 W / cm² light intensity. 2 , irradiation dose 30mJ / cm 2 The coated HC layer-forming curable composition was cured by ultraviolet light to form a first HC layer, and then wound up.

[0750] (ii) Fabrication of the Second HC Layer

[0751] On the surface of the first HC layer formed above, the curable composition HC-2 for forming an HC layer was applied and cured to form a second HC layer having a film thickness of 4 μm.

[0752] The coating and curing methods are described in detail below. The HC layer-forming curable composition was applied using the slot die coating method described in Example 1 of Japanese Patent Application Laid-Open No. 2006-122889 at a conveying speed of 30 m / min and dried for 150 seconds at an ambient temperature of 60°C. Subsequently, under nitrogen purge, the film was irradiated with an illuminance of 300 mW / cm² using an air-cooled metal halide lamp (manufactured by EYE GRAPHICS Co., Ltd.) with an oxygen concentration of approximately 0.1% by volume and a 160 W / cm². 2 , irradiation dose 600mJ / cm 2 The resin film 3 to which the HC layer is applied (hereinafter referred to as the resin film 3 having the HC layer) is produced by irradiating the resin film with ultraviolet rays to form the second HC layer and then winding the film.

[0753] [Saponification treatment]

[0754] The resin film 3 having the HC layer produced above was immersed in a 1.5 mol / L aqueous NaOH solution (saponification solution) maintained at 55°C for 2 minutes, then rinsed with water. The film was then immersed in a 0.05 mol / L aqueous sulfuric acid solution at 25°C for 30 seconds, and then rinsed under running water for 30 seconds to neutralize the film. Dehydration with an air knife was repeated three times, and after water removal, the film was dried in a drying zone at 70°C for 15 seconds, thereby producing a saponified resin film 3 having the HC layer.

[0755] <3. Preparation of shock absorbing layer>

[0756] The SA layer-forming composition SA-4 was applied to the surface of the saponified resin film 3 having the HC layer, opposite to the surface on which the HC layer was formed, and dried to form the SA layer. The coating and drying methods are described below. The SA layer-forming composition was applied using the slot die coating method described in Example 1 of Japanese Patent Application Laid-Open No. 2006-122889 at a conveyor speed of 30 m / min to a film thickness of 10 μm after drying. The composition was then dried at an ambient temperature of 60°C for 150 seconds to produce the optical film of Example 4.

[0757] [Example 5]

[0758] An optical film of Example 5 was produced in the same manner as in Example 4, except that SA-5 was used instead of the SA layer-forming composition SA-4.

[0759] [Example 6]

[0760] An optical film of Example 6 was produced in the same manner as in Example 4 except that SA-7 was used instead of the SA layer-forming composition SA-4.

[0761] [Example 7]

[0762] An optical film of Example 7 was produced in the same manner as in Example 3 except that SA-8 was used instead of the SA layer-forming composition SA-3 and the film thickness after drying was set to 40 μm.

[0763] [Comparative Example 1]

[0764] An optical film of Comparative Example 1 was produced in the same manner as in Example 1, except that SA-6 was used instead of the SA layer-forming composition SA-1.

[0765] [Comparative Example 2]

[0766] An optical film of Comparative Example 2 was produced in the same manner as in Example 4, except that SA-6 was used instead of the SA layer-forming composition SA-4.

[0767] The impact absorbing layer constituting the optical film produced above was subjected to the following tests. The optical film structure and test results are summarized in Table 3 below.

[0768] [Test Example A] Measurement of Dynamic Viscoelasticity of Impact-Absorbing Layer

[0769] <Sample Preparation Method>

[0770] The composition for forming the impact-absorbing layer (SA layer) prepared above was applied to the release-treated surface of a release-treated release PET (polyethylene terephthalate) sheet to a thickness of 40 μm after drying. After drying, the impact-absorbing layer was peeled from the release PET sheet to prepare a test piece of the impact-absorbing layer.

[0771] The coating and drying conditions were the same as those described in the SA layer formation method in Example 1. The SA layer-forming composition SA-2 was coated and dried, and then cured by ultraviolet irradiation under the conditions described in Example 2.

[0772] <Measurement Method>

[0773] The above test piece, which had been previously conditioned for at least 2 hours at a temperature of 25°C and a relative humidity of 60%, was measured using a dynamic viscoelasticity measuring apparatus (manufactured by IT Keisoku Seigyo Co., Ltd., product name: DVA-225) in the "Step Temperature Ramp Frequency Dispersion" mode under the following conditions. A master curve of tan δ, storage modulus, and loss modulus relative to frequency at 25°C was obtained by "Master Curve Editing." The following master curves were used to determine the relative strength of the test piece at 25°C and a frequency of 10°C. 6 The maximum values ​​of the storage modulus E' and tan δ in Hz and the frequency at which they occur.

[0774] In the following table, the 6 Hz(1.0×10 6 The storage modulus E' under 25°C and frequency 10 Hz) is recorded in the "Storage modulus" or "E'" column. -1 ~10 15 Hz(1.0×10 -1 ~1.0×10 15 The maximum value of tan δ within the range of Hz) is described in the "tan δ" column.

[0775] The impact absorption layer in the rear polarizer is at 25°C and a frequency of 10 -1 ~10 6 Hz(1.0×10 -1 ~1.0×10 6 The tan δ values ​​within the range of Hz) were all 3.0 or less.

[0776] Specimen: 5mm×50mm

[0777] Test mode: tensile deformation mode

[0778] Distance between fixtures: 20mm

[0779] Set distortion: 0.10%

[0780] Measuring temperature: -100℃~40℃

[0781] Heating conditions: 2℃ / min

[0782] [Test Example B] Measurement of film thickness

[0783] The "film thickness" was measured by the following method and observation using a scanning electron microscope (SEM).

[0784] After exposing the cross-sections of each component (resin film, impact-absorbing layer, and HC layer) or a component containing each component (e.g., a liquid crystal panel) using conventional methods such as an ion beam or microtome, SEM cross-sectional observations were performed on the exposed cross-sections. For cross-sectional observations, the thickness of each film was calculated as the arithmetic average of the thicknesses at the three equal points, excluding the two ends, when the component was divided into four equal parts in the width direction.

[0785] [Table 3]

[0786]

[0787] <<Production of Polarizing Plate>>

[0788] <Resin Film 4>

[0789] A commercially available cellulose acylate film (product name: FUJITAC ZRD40, manufactured by Fuji Film Corporation) was prepared and used as the resin film 4 .

[0790] <Saponification treatment>

[0791] The resin films 1, 3, and 4 were immersed in a 1.5 mol / L aqueous NaOH solution (saponification solution) maintained at 55°C for 2 minutes, then rinsed with water. The films were then immersed in a 0.05 mol / L aqueous sulfuric acid solution at 25°C for 30 seconds, and then rinsed in a water bath under running water for 30 seconds to neutralize the film. Dehydration with an air knife was repeated three times, and after water removal, the films were dried in a drying zone at 70°C for 15 seconds, thereby producing saponified resin films 1, 3, and 4.

[0792] <Production of Polarizer>

[0793] According to Example 1 of Japanese Patent Application Laid-Open No. 2001-141926, iodine was adsorbed on a stretched polyvinyl alcohol film to produce a polarizer having a film thickness of 26 μm.

[0794] (Production of Polarizing Plates)

[0795] The saponified resin film 4 (inner protective film) was attached to one side of the polarizer produced by the above method, which had nothing bonded to either side, using a polyvinyl alcohol-based adhesive, and then dried at 70°C for at least 10 minutes. Next, the optical films of Examples 1 to 7 and Comparative Examples 1 and 2, and either of the saponified resin films 1 and 3 (outer protective film) were attached to the surface of the polarizer produced by the above method opposite to the surface bonded to the resin film 4, using a polyvinyl alcohol-based adhesive, and then dried at 70°C for at least 10 minutes. This produced the polarizers A1 to A7, a1, a2, b1, and b2 listed in Table 4 below.

[0796] The polarizing plate obtained above has a structure in which an outer protective film, a polarizer, and an inner protective film are laminated in this order. The lamination surfaces of the outer protective film and the polarizer are as follows. The optical films of Examples 1 to 3 and 7 and Comparative Example 1 were laminated to the surface not laminated with the impact-absorbing layer, i.e., the resin film and the polarizer were laminated. The optical films of Examples 4 to 6 and Comparative Example 2 were laminated to the surface laminated with the impact-absorbing layer, i.e., the impact-absorbing layer and the polarizer were laminated. Resin films 1 and 3 were laminated to the polarizer on the side of the resin film opposite to the side in contact with the casting tape.

[0797] (Production of Polarizing Plate A8)

[0798] On the resin film 4 side of the polarizing plate A6 produced above, an impact absorbing layer was produced by the same method as in Example 3, thereby producing a polarizing plate A8.

[0799] (Production of Polarizing Plate A9)

[0800] On the resin film 4 side of the polarizing plate A7 produced above, an impact absorbing layer was formed in the same manner as in Example 1 so that the thickness after drying would be 20 μm, thereby producing a polarizing plate A9.

[0801] [Table 4]

[0802]

[0803] The following tests were performed on the polarizing plates produced above. The test results are summarized in Table 5 below.

[0804] <Production of Analog LCD Panel>

[0805] [Test Example 1] Impact Absorption

[0806] A glass plate (Corning Incorporated, product name: EAGLE XG, thickness 0.4 mm) and the polarizer prepared above were bonded together using a rubber roller while applying a 2 kg load to form the structure shown in Table 5, thereby producing a simulated liquid crystal panel. Furthermore, the absorption axis of the front polarizer was oriented in the left-right direction, and the transmission axis of the rear polarizer was oriented in the left-right direction, that is, the transmission axes of the two polarizers were orthogonal to each other, forming a crossed Nicol arrangement.

[0807] Specifically, polarizers A1 to A7, a1 to a2, and b1 to b2 were bonded together with a 20 μm thick adhesive (manufactured by Soken Chemical & Engineering Co., Ltd., product name: SK-2057) so that the polarizer's resin film 4 faced the glass plate. Furthermore, polarizers A8 to A9 were bonded together without adhesive so that the impact-absorbing layer formed on the polarizer's resin film 4 side faced the glass plate. That is, using the simulated liquid crystal panel of Example 110 as an example, the impact-absorbing layers were arranged in the order of impact-absorbing layer 1, impact-absorbing layer 2, impact-absorbing layer 4, and impact-absorbing layer 3 from the visual recognition side. Each polarizer was cut into a 10 cm square for use.

[0808] Then, the simulated liquid crystal panel was placed on a stainless steel base so that a stainless steel spacer with a thickness of 20 mm and a width of 5 mm (a spacer with a 9 cm square center was punched out from a 10 cm square spacer) was sandwiched between the simulated liquid crystal panel and the stainless steel base. Figure 3 .exist Figure 3 In the embodiment, a base 301, a spacer 302, a rear polarizer 303, an adhesive layer or a shock absorbing layer 304, a glass plate 305, an adhesive layer or a shock absorbing layer 306, and a front polarizer 307 are stacked in this order.

[0809] Next, an iron ball (3.2 cm in diameter, 130 g in mass) was dropped from specified heights (10 cm, 25 cm, 40 cm, 50 cm, 55 cm, and 60 cm) to collide with the front polarizer until they came into contact. The glass plate was then observed for cracks and breakage, and the relationship between the drop height of the iron ball and the damage to the glass plate was applied to the following evaluation criteria to evaluate the impact absorption. In this test, a score of "D" or higher was considered acceptable.

[0810] <Evaluation Criteria>

[0811] A++: No damage even after a drop from a height of 60 cm.

[0812] A+: No damage after a drop of 55 cm, but damaged after a drop of 60 cm.

[0813] A: It was not damaged after being dropped from a height of 50 cm, but it was damaged after being dropped from a height of 55 cm.

[0814] B: No damage after being dropped from a height of 40 cm, but damaged after being dropped from a height of 50 cm.

[0815] C: No damage after being dropped from a height of 25 cm, but damaged after being dropped from a height of 40 cm.

[0816] D: No damage after being dropped from a height of 10 cm, but damaged after being dropped from a height of 25 cm.

[0817] E: Broken after falling from a height of 10 cm.

[0818] The results of the impact absorbency test are shown in Table 5 below.

[0819]

[0820] As shown in Table 5, the pseudo-liquid crystal panels of Comparative Examples 101 and 102, which did not include the optical film of the present invention as a polarizing plate, were inferior in impact absorption.

[0821] In contrast, the pseudo-liquid crystal panels of Examples 101 to 110, which included the optical film of the present invention as at least one of the front and rear polarizers, demonstrated sufficient impact absorption. Among the aforementioned examples, Examples 106 to 110, which included the optical film of the present invention as both the front and rear polarizers, showed no damage even when dropped by an iron ball from a height of 50 cm, demonstrating excellent impact absorption.

[0822] The present invention has been described together with its embodiments, but the inventors believe that, unless otherwise specified, the present invention will not be limited in any details of the description and should be interpreted broadly without violating the spirit and scope of the invention shown in the attached technical solutions.

[0823] This application claims priority based on Japanese Patent Application No. 2018-098318 filed in Japan on May 22, 2018, and Japanese Patent Application No. 2018-114622 filed in Japan on June 15, 2018, the contents of which are incorporated herein by reference as part of the description of this specification.

[0824] Explanation of symbols

[0825] 1A-resin film, 2A-impact absorbing layer, 3A-hard coating layer, 4A, 4B-optical film, 301-base, 302-spacer, 303-rear polarizer, 304-adhesive layer or impact absorbing layer, 305-glass plate, 306-adhesive layer or impact absorbing layer, 307-front polarizer.

Claims

1. An optical film comprising a resin film and a shock absorbing layer disposed on at least one surface of the resin film, The impact absorbing layer is heated at 25°C and a frequency of 10 6 The storage modulus E' at Hz is below 1 GPa, The resin film is one of an acrylic resin film, a cellulose ester resin film, a polyethylene terephthalate resin film, and a polycarbonate resin film.

2. An optical film comprising a resin film, an impact absorbing layer disposed on at least one surface of the resin film, and a hard coating layer disposed on a surface opposite to the surface on which the impact absorbing layer is disposed. The impact absorbing layer is heated at 25°C and a frequency of 10 6 The storage modulus E' at Hz is below 1 GPa, The hard coating layer has a thickness of 3 μm to 100 μm.

3. An optical film comprising a resin film and a shock absorbing layer disposed on at least one surface of the resin film, The impact absorbing layer is heated at 25°C and a frequency of 10 6 The storage modulus E' at Hz is greater than 1 MPa and less than 1 GPa, The impact absorbing layer has a thickness of 10 μm to 80 μm.

4. The optical film according to claim 1 or 2, wherein The impact absorbing layer has a thickness of 10 μm to 80 μm.

5. The optical film according to claim 1 or 3, wherein The resin film has a hard coating layer on a surface opposite to a surface on which the impact absorbing layer is arranged. A polarizing plate comprising the optical film according to any one of claims 1, 3 and 4. 7 . A polarizing plate comprising the optical film according to claim 2 . 8 . A liquid crystal panel comprising the polarizing plate according to claim 6 as a rear polarizing plate. 9 . A liquid crystal panel comprising the polarizing plate according to claim 7 as a front polarizing plate. 10 . A liquid crystal panel comprising the polarizing plate according to claim 6 as a rear polarizing plate and the polarizing plate according to claim 7 as a front polarizing plate.

11. The liquid crystal panel according to claim 10, wherein: The storage modulus E' of the impact absorbing layer of the optical film of the rear polarizer r and the storage modulus E' of the impact absorbing layer of the optical film of the front polarizer f Satisfies the following formula: AND' f -AND' r ≥0。 12. The liquid crystal panel according to any one of claims 8 to 11, wherein Equipped with a touch sensor. 13 . A touch panel comprising the optical film according to claim 1 and a touch sensor film bonded together.

14. The liquid crystal panel according to any one of claims 8 to 11, wherein A touch panel according to claim 13 is provided. 15 . An image display device comprising the liquid crystal panel according to claim 8 .

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