Hard Coat Film

Abstract

The hard coat film 10 comprises a substrate 11 and a hard coating layer 12 made of a cured product of a resin composition containing a resin (A) and a resin (B) and laminated on the substrate 11, the resin (A) being a polyfunctional (meth)acrylic monomer having a weighted average functionality of 4 or more. The resin (B) is an aliphatic urethane acrylate. The glass transition temperature Tg of the hard coating layer 12 is 50°C or more and 100°C or less. When the loss tangent tanδ of the hard coating layer 12 is measured by dynamic viscoelasticity measurement in which a dynamic load of a frequency of 1 Hz is applied, the loss tangent tanδ at the glass transition temperature Tg is 0.07 or more and 0.15 or less.

Description

[Technical field]

[0001] The present disclosure relates to a hard coat film. [Background technology]

[0002] Display devices such as liquid crystal displays (LCD), plasma displays (PDP), and organic light emitting displays (OLED) are widely used in smartphones, mobile phones, portable personal computers, car navigation devices, and the like. In general, a protective film is provided on the top surface of the screen of a display device to prevent the screen from being scratched. The protective film includes a substrate and a hard coating layer laminated on the substrate. Conventional hard coating layers are formed of materials with high crosslink density.

[0003] Currently, flexible display devices having a flexible screen and capable of being folded are being developed. Flexible display devices are required to be capable of being repeatedly folded many times, such as hundreds of thousands of times, in one or more directions. For this reason, a protective film covering the screen of a flexible display device is also required to have flexibility capable of enduring the repeated folding many times.

[0004] However, the high crosslink density material used in the conventional hard coating layer has hardness but lacks flexibility due to its high shrinkage rate. Therefore, when a flexible display device covered with a protective film having a conventional hard coating layer is repeatedly folded many times, such as several hundred thousand times, the hard coating layer and the protective film are likely to peel off from the screen. In addition, if the crosslink density of the material of the hard coating layer is high, the hard coating layer becomes brittle or easily cracks even if the thickness of the hard coating layer itself is thin.

[0005] As an example of a flexible hard coating layer, Patent Document 1 discloses a 5 μm thick hard coating layer that can be bent around a mandrel with a diameter of 2 mm without cracking. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US Patent Publication No. 2009 / 0004478 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the above-mentioned Patent Document 1 does not disclose anything about repeatedly folding the hard coating layer a large number of times, such as several hundred thousand times, or about the material and characteristics of the hard coating layer required for such repeated folding.

[0008] In addition, if the hard coating layer is made of a flexible material to enable multiple folding, the scratch resistance of the hard coating layer is reduced, making the hard coating layer more susceptible to scratches. Therefore, the hard coating layer used in the protective film of the flexible display device is required to have not only the performance to withstand the multiple repeated folding, but also scratch resistance to prevent scratches.

[0009] Therefore, the present invention has been made in consideration of the above problems, and an object of the present invention is to provide a hard coat film that has both the ability to withstand repeated folding many times and scratch resistance. [Means for solving the problem]

[0010] In order to solve the above problems, according to one aspect of the present invention, A substrate; a hard coating layer comprising a cured product of a resin composition comprising a resin (A) and a resin (B) and laminated on the substrate; Equipped with The resin (A) is a polyfunctional (meth)acrylic monomer having a weighted average functionality of 4 or more, The resin (B) is an aliphatic urethane acrylate, The glass transition temperature Tg of the hard coating layer is 50° C. or more and 100° C. or less, When the loss tangent tanδ of the hard coating layer is measured by dynamic viscoelasticity measurement in which a dynamic load of a frequency of 1 Hz is applied, the loss tangent tanδ at the glass transition temperature Tg is 0.07 or more and 0.15 or less, thereby providing a hard coat film.

[0011] The resin composition may further comprise metal oxide nanoparticles having an average particle size of 100 nm or less.

[0012] In one embodiment, the content of the metal oxide nanoparticles in the resin composition may be 2% by mass or more and 5% by mass or less based on the total solid content of the resin composition of the hard coating layer.

[0013] The metal oxide constituting the metal oxide nanoparticles may be either or both of silica and alumina.

[0014] The metal oxide nanoparticles may have a Mohs hardness of greater than 6.

[0015] When an abrasion tester using steel wool #0000 is used to abrade the surface of the hard coating layer with the steel wool under conditions of a load of 1000 g, a speed of 50 mm / sec, a reciprocating distance of 40 mm, and a number of reciprocating movements of 2500, the water contact angle of the surface of the hard coating layer after abrasion may be greater than 100 degrees.

[0016] In some embodiments, the water contact angle of the surface of the hard coating layer before abrasion may be greater than 110 degrees.

[0017] In one embodiment, the reduction rate of the water contact angle of the surface of the hard coating layer after abrasion relative to the water contact angle before abrasion may be less than 13%.

[0018] In one embodiment, the content of the resin (A) in the resin composition may be more than 2 times and less than 9 times the content of the resin (B).

[0019] In one embodiment, the content of the resin (A) in the resin composition may be 20% by mass or more and 40% by mass or less, and the content of the resin (B) in the resin composition may be 2% by mass or more and 15% by mass or less.

[0020] The hard coat film may be configured to be capable of being folded, either in or out, at least 100,000 times without cracking, delaminating, and / or losing optical properties.

[0021] The substrate may be a thermoplastic substrate having a thickness of 10 μm or more and 200 μm or less.

[0022] The resin composition may contain a fluorine compound, and the fluorine compound may be segregated in a first region located on the surface side of the hard coating layer.

[0023] Furthermore, the segregated fluorine compound may have an antifouling function.

[0024] In one embodiment, the fluorine compound may be segregated on the surface of the hard coating layer.

[0025] In one embodiment, the hard coat film may be configured to be capable of being folded, either in or out, at least 100,000 times without loss of the optical properties, which are one or more selected from the group consisting of total light transmittance (%), transmission haze, gloss, and variation in chromaticity b* (intensity of color from blue to yellow).

[0026] In one embodiment, the fluorine compound may not be segregated in the second region located on the substrate side of the hard coating layer. Effect of the Invention

[0027] According to an embodiment of the present invention, it is possible to provide a hard coat film that has both the ability to withstand repeated folding many times and scratch resistance. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a cross-sectional view showing a hard coat film according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing a hard coat film according to another embodiment of the present invention. [Diagram 3] FIG. 3 is a cross-sectional view showing a hard coat film according to another embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing a hard coat film manufacturing apparatus according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, specific values, etc. shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanation. Elements not directly related to the present invention are not shown.

[0030] In the drawings referred to in the following description, the size of some components may be exaggerated for the sake of convenience, and the relative sizes of the components shown in the drawings do not necessarily accurately represent the proportional relationships between the actual components.

[0031] [1. Overall structure of hard coat film] First, the overall structure of a hard coat film 10 according to one embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a cross-sectional view showing a hard coat film 10 according to this embodiment.

[0032] The hard coat film 10 according to this embodiment is provided on the outermost surface of a flexible display device as a protective film for preventing scratches, for example. As shown in Fig. 1, the hard coat film 10 according to this embodiment includes a substrate 11 and a hard coating layer 12. The hard coating layer 12 is laminated on the substrate 11. Each layer will be described below.

[0033] [Base material 11] The base material 11 is formed of a transparent material that can transmit light in the visible light range having a wavelength of, for example, 350 to 830 nm.

[0034] The substrate 11 may be made of, for example, an inorganic material such as a glass film, or an organic material such as a plastic film.

[0035] The material of the plastic film is, for example, one or more selected from the group consisting of polyester-based resins, acetate-based resins, polyethersulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyolefin-based resins, poly(meth)acrylate-based resins, polyvinyl chloride-based resins, polyvinylidene chloride-based resins, polystyrene-based resins, polyvinyl alcohol-based resins, polyarylate-based resins, and polyphenylene sulfide-based resins, and may be preferably any one or more of polyester-based resins, acetate-based resins, polycarbonate-based resins, polyimide-based resins, and polyolefin-based resins.

[0036] From the viewpoints of handleability, flexibility, cost, and characteristics, the thickness of the substrate 11 is, for example, preferably 10 μm or more and 200 μm or less, more preferably 20 μm or more and 100 μm or less, and even more preferably 40 μm or more and 60 μm or less.

[0037] When the thickness of the substrate 11 is 10 μm or more, at least one of the following advantages is obtained. Since the rigidity of the substrate 11 itself can be ensured, even if stress is applied to the hard coat film 10, wrinkles are unlikely to occur in the hard coat film 10. Furthermore, even if the hard coating layer 12 is continuously formed on the substrate 11, wrinkles are unlikely to occur in the hard coat film 10, so problems in manufacturing the hard coat film 10 can be reduced. Furthermore, since curling of the hard coat film 10 is reduced, it is not necessary to laminate an additional coating layer on the back surface of the substrate 11. The back surface of the substrate 11 refers to the surface opposite to the surface on which the hard coating layer 12 is laminated.

[0038] When a roll is used in the production of the hard coat film 10, the thickness of the substrate 11 is preferably 200 μm or less. When the thickness of the substrate 11 is 200 μm or less, the hard coat film 10 during production and the hard coat film 10 after production can be easily wound into a roll, and the hard coat film 10 can be efficiently produced. In addition, the substrate 11 is preferably a thermoplastic substrate.

[0039] The substrate 11 may be previously subjected to a surface treatment for the purpose of improving adhesion. The surface treatment may be, for example, one or more treatments selected from the group consisting of corona treatment, plasma treatment, ultraviolet treatment, excimer treatment, and primer treatment. In order to improve adhesion, a surface treatment using a silane coupling agent is particularly preferable. In addition, it is also preferable to remove dust and clean the surface of the substrate 11 with a web cleaner or the like, as necessary, before forming the hard coating layer 12 on the substrate 11.

[0040] [Hard coating layer 12] The hard coating layer 12 is provided on the substrate 11. The hard coating layer 12 may be, for example, a cured product of a resin composition. In this embodiment, the resin composition contains a resin (A), a resin (B), an energy ray-activated polymerization initiator, and a solvent.

[0041] Resin (A) and resin (B) may be energy ray curable resins such as ultraviolet ray curable resins, electron beam curable resins, and infrared ray curable resins. It is preferable to use ultraviolet ray curable resins as resin (A) and resin (B). This is because post-treatment after curing is not required. It is preferable to cure under a nitrogen atmosphere in order to perform the curing process appropriately.

[0042] The resin (A) may be a polyfunctional (meth)acrylic monomer having a weighted average functional group of 4 or more. The weighted average functional group number of the resin (A) is preferably more than 4.2 and less than 5.1. In the present embodiment, the resin (A) contains, for example, a difunctional acrylic monomer and a hexafunctional acrylic monomer. As the difunctional acrylic monomer, for example, SARTOMER's product "SR833S" (difunctional tricyclodecanedimethanol diacrylate) or "SR306" (tripropylene glycol diacrylate) can be mentioned. As the hexafunctional acrylic monomer, DAICEL-ALLNEX LTD.'s product "DPHA" (dipentaerythritol hexaacrylate) can be mentioned. Here, instead of the difunctional acrylic monomer, or in addition to the difunctional acrylic monomer, at least one of a trifunctional acrylic monomer, a tetrafunctional acrylic monomer, or a pentafunctional acrylic monomer may be used. Examples of trifunctional monomers include "SR351" (trimethylolpropane triacrylate) and "SR454" (ethoxylated trimethylolpropane triacrylate), all of which are available from SARTOMER. Examples of tetrafunctional monomers include "SR295" (pentaerythritol tetraacrylate), "SR355" (di-trimethylolpropane tetraacrylate), and "SR494" (ethoxylated pentaerythritol tetraacrylate), all of which are available from SARTOMER. Examples of pentafunctional monomers include "SR399" (dipentaerythritol pentaacrylate), all of which are available from SARTOMER.

[0043] In this embodiment, the resin (B) is an aliphatic urethane acrylate. The resin (B) is, for example, a trifunctional aliphatic urethane acrylate, a trifunctional aliphatic polyester urethane acrylate, or the like. Specific examples of the resin (B) available on the market include SARTOMER's product "CN989" (trifunctional aliphatic urethane acrylate) and product "CN929" (trifunctional aliphatic polyester urethane acrylate).

[0044] By forming the hard coating layer 12 from a cured product of a resin composition containing the resin (A) which is a polyfunctional (meth)acrylic monomer having a weighted average functional group of 4 or more and the resin (B) which is an aliphatic urethane acrylate, the glass transition temperature Tg of the hard coating layer 12 can be set to 50°C or more and 100°C or less. In addition, by forming the hard coating layer 12 in the same manner, the loss tangent tanδ of the hard coating layer 12 at the glass transition temperature Tg can be set to 0.07 or more and 0.15 or less. The loss tangent tanδ of the hard coating layer 12 at the glass transition temperature Tg is a value calculated by dynamic viscoelasticity measurement in which a dynamic load of a frequency of 1 Hz is applied. In addition, the loss tangent tanδ is the ratio of the storage modulus (E') to the loss modulus (E') (tanδ=E' / E'). The storage modulus (E') is the component of the internal energy increase when a strain is generated in the object. The storage modulus (E') indicates the elastic properties of the object. The loss modulus (E') is the component of energy lost when strain occurs in an object. Loss energy is the energy that diffuses outside the object as heat. The loss modulus (E') indicates the viscous properties of the object.

[0045] If the glass transition temperature Tg is less than 50° C., the hard coating layer 12 becomes soft in a high-temperature environment such as the inside of a vehicle, and the scratch resistance of the hard coating layer 12 is significantly reduced. On the other hand, if the glass transition temperature Tg is more than 100° C., the flexibility of the hard coating layer 12 cannot be ensured, and it becomes difficult to repeatedly fold the hard coating layer 12 many times.

[0046] Therefore, it is preferable that the glass transition temperature Tg of the hard coating layer 12 is set to 50° C. or higher and 100° C. or lower. This makes it possible to improve the scratch resistance of the hard coating layer 12 even in a high-temperature environment such as the inside of a vehicle, and also makes it possible for the hard coating layer 12 to be repeatedly folded a large number of times, such as 100,000 times or more.

[0047] If the loss tangent tan δ of the hard coating layer 12 at the glass transition temperature Tg is less than 0.07, the hardness of the hard coating layer 12 becomes too high, resulting in a decrease in flexibility of the hard coating layer 12. On the other hand, if the loss tangent tan δ of the hard coating layer 12 at the glass transition temperature Tg is more than 0.15, the hardness of the hard coating layer 12 becomes too low, resulting in a decrease in scratch resistance of the hard coating layer 12.

[0048] Therefore, it is preferable that the loss tangent tanδ of the hard coating layer 12 at the glass transition temperature Tg is 0.07 to 0.15, which can improve the scratch resistance of the hard coating layer 12 and also enable the hard coating layer 12 to be repeatedly folded over 100,000 times or more.

[0049] The content (mass%) of resin (A) in the resin composition is preferably more than 2 times and less than 9 times the content (mass%) of resin (B), more preferably 4 times or more and less than 9 times, and even more preferably 4 times or more and 5 times or less. The content (mass%) of resin (A) in the resin composition is preferably 20% by mass or more and 40% by mass or less, and more preferably 26% by mass or more and 33% by mass or less. The content (mass%) of resin (B) in the resin composition is preferably 2% by mass or more and 15% by mass or less, and more preferably 4.5% by mass or more and 11.5% by mass or less.

[0050] In this embodiment, the energy beam-activated polymerization initiator is a Norrish type I photoinitiator or a Norrish type II photoinitiator. Specific examples of energy beam-activated polymerization initiators available on the market include IGM Resins (formerly BASF) products "OMNIRAD 184 (IRGACURE 184)" (1-hydroxycyclohexyl phenyl ketone), "OMNIRAD 500 (IRGACURE 500)" (mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone), and "OMNIRAD TPO" (2,4,6-trimethylbenzoyldiphenylphosphine oxide).

[0051] The solvent is not particularly limited as long as it satisfies the coating property of the resin composition, but is preferably selected in consideration of safety. In this embodiment, the solvent includes one or more selected from the group consisting of alcohol-based solvents such as ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, and diacetone alcohol, ketone-based solvents such as acetone, methyl ethyl ketone (hereinafter, MEK), methyl isobutyl ketone, and cyclohexanone, ester-based solvents such as methyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate (hereinafter, PGMEA), and ether-based solvents such as propylene glycol monomethyl ether (hereinafter, PGME), diethyl ether, and diisopropyl ether. Preferably, it includes any one of MEK, PGME, and PGMEA. In particular, it is preferable to use either one or both of PGME and PGMEA, which can improve the coating property of the resin composition.

[0052] The thickness of the hard coating layer 12 is, for example, preferably 3 μm or more, more preferably 5 μm or more. When the thickness of the hard coating layer 12 is 3 μm or more, sufficient hardness is obtained, so that the hard coating layer 12 is less likely to be scratched during the manufacturing process. Moreover, the thickness of the hard coating layer 12 is preferably 15 μm or less, more preferably 10 μm or less. When the thickness of the hard coating layer 12 is 15 μm or less, microcracks in the hard coating layer 12 that occur when the hard coat film 10 is bent during manufacturing are less likely to occur, so the productivity of the hard coat film 10 is good.

[0053] Metal oxide nanoparticles may be dispersed and contained in the resin composition of the hard coating layer 12. When the resin composition contains metal oxide nanoparticles, the hardness of the hard coating layer 12 can be increased.

[0054] The average particle size of the metal oxide nanoparticles is, for example, preferably 100 nm or less, and more preferably 50 nm or less. Note that in this embodiment, the average particle size refers to a value measured by the BET method.

[0055] If the average particle size of the metal oxide nanoparticles is larger than 100 nm, the transmittance of visible light of the hard coating layer 12 may decrease. Therefore, by setting the average particle size of the metal oxide nanoparticles to 100 nm or less, the transmittance of visible light of the hard coating layer 12 can be maintained. By setting the average particle size of the metal oxide nanoparticles to 50 nm or less, these advantages can be further exhibited. When the substrate 11 is an opaque substrate, the light transmittance of the hard coating layer 12 does not need to be high, so the average particle size of the metal oxide nanoparticles may be larger than 100 nm.

[0056] The content of the metal oxide nanoparticles (excluding monomers) in the resin composition is preferably 2% by mass or more and 5% by mass or less with respect to the total solid content of the resin composition of the hard coating layer 12. If the content of the metal oxide nanoparticles is more than 5% by mass, the hard coating layer 12 tends to become brittle. Therefore, by setting the content of the metal oxide nanoparticles according to this embodiment within the above range, the flexibility of the hard coating layer 12 can be maintained. The solid content of the resin composition refers to all components other than the solvent, and the liquid monomer component is also included in the solid content.

[0057] In this embodiment, the metal oxide constituting the metal oxide nanoparticles is either or both of SiO2 (silica) and Al2O3 (alumina), which can prevent a decrease in the transmittance of light in the visible light range of the hard coating layer 12.

[0058] The metal oxide nanoparticles preferably have a Mohs hardness of greater than 6. This allows the hardness of the hard coating layer 12 to be increased without decreasing the flexibility of the hard coating layer 12.

[0059] [Anti-stain layer 13] In another embodiment of the present invention, an antifouling layer 13 may be provided as a part of the hard coating layer 12. FIG. 2 is a cross-sectional view showing a hard coat film 10 according to another embodiment of the present invention. As shown in FIG. 2, the fluorine compound contained in the hard coating layer 12 segregates in the first region 12a located on the surface side of the hard coating layer 12 to form the antifouling layer 13. The fluorine compound does not segregate in the second region 12b located on the substrate 11 side of the hard coating layer 12. In other words, the amount of the fluorine compound in the second region 12b is less than the amount of the fluorine compound in the first region 12a. The second region 12b may contain a fluorine compound. The fluorine compound may be dispersed (dispersed) in the second region 12b. The first region 12a has a thickness Ta of, for example, 10% of the total thickness T of the hard coating layer 12 at most. The second region 12b is a region of the hard coating layer 12 other than the first region 12a. In this specification, "segregation" means that when the resin composition is cured, the distribution of the fluorine compound in the resin composition becomes larger on the surface side of the hard coating layer 12 than on the substrate 11 side. The antifouling layer 13 prevents contamination of the hard coating layer 12. The antifouling layer 13 may or may not be a strict layer, depending on the segregation state of the fluorine compound.

[0060] The antifouling layer 13 contains a fluorine compound. The fluorine compound preferably has a (meth)acrylic group. From the viewpoint of environmental regulations, the fluorine compound is preferably a perfluoropolyether derivative rather than a fluoroalkyl derivative. The fluorine compound may be a hybrid material of an organic material and an inorganic material. An example of the hybrid material is fluorine-containing silsesquioxane. In this embodiment, since the antifouling layer 13 contains a fluorine compound, the antifouling property and chemical resistance of the hard coat film 10 can be improved. The chemical resistance is, for example, resistance to acids, bases, solvents, and oils.

[0061] Examples of fluorine compounds contained in the anti-fouling layer 13 include "KY-1203" manufactured by Shin-Etsu Chemical Co., Ltd., "Optool DAC-HP" manufactured by Daikin Industries, Ltd., "Fluorolink AD1700" manufactured by Solvay Specialty Polymers, and "CN4000" manufactured by SARTOMER.

[0062] [2. Characteristics of hard coating layer 12] Next, the characteristics of the hard coating layer 12 according to this embodiment will be described. The hard coating layer 12 according to this embodiment has, for example, at least one of the following characteristics (I) to (IV).

[0063] (I) Glass transition temperature Tg and loss tangent tanδ The glass transition temperature Tg of the hard coating layer 12 is from 50° C. to 100° C., preferably from 60° C. to 90° C. The loss tangent tan δ is from 0.07 to 0.15, preferably from 0.09 to 0.13.

[0064] This makes it possible to improve the scratch resistance and abrasion resistance of the hard coating layer 12 even in a high-temperature environment such as the inside of a vehicle, and also makes it possible for the hard coating layer 12 to be repeatedly folded a large number of times, up to more than 100,000 times.

[0065] The glass transition temperature Tg and the loss tangent tan δ can be measured, for example, using a viscoelasticity measuring device DMA7100 manufactured by Hitachi High-Tech Science Corporation. The measurement conditions for the dynamic viscoelasticity measurement when calculating the glass transition temperature Tg and the loss tangent tan δ are as follows. Sine wave vibration with frequency: 1Hz Sample size: length 20mm x width 4.4mm x thickness 0.10mm Test method: Temperature increase from 20℃ to 200℃ at a rate of 10℃ / min

[0066] (II) Number of folds The hard coat film 10 is configured so that it can be folded in or out at least 100,000 times without cracking, delamination, or loss of optical properties. Here, the optical properties include, for example, variations in total light transmittance (%), transmission haze, glossiness, and chromaticity b* (intensity of color from blue to yellow). With the above configuration, even if a flexible display device covered with the hard coat film 10 is repeatedly folded many times, several hundred thousand times, it is possible to prevent the hard coat film 10 from peeling off from the flexible display device.

[0067] The number of folds (number of bends) can be measured, for example, using a folding test device manufactured by Yuasa System Equipment Co., Ltd. (mandrel diameter: 3 mm, bending radius: 1.5 mm).

[0068] (III) Water contact angle (WCA) The water contact angle is an angle formed between the surface of a water droplet and the surface of the hard coating layer 12 when a water droplet is brought into contact with the surface of the hard coating layer 12. The water contact angle is measured before and after the abrasion test.

[0069] The abrasion test is performed using an abrasion tester with steel wool #0000, in which the steel wool is abraded against the surface of the hard coating layer 12 under the following conditions: load: 1000 g, speed: 50 mm / sec, reciprocation distance: 40 mm, number of reciprocations: 2500 times.

[0070] The water contact angle θ1 of the surface of the hard coating layer 12 before the abrasion test (before abrasion) is desirably greater than 110 degrees and less than 120 degrees. The water contact angle θ2 of the surface of the hard coating layer 12 after the abrasion test (after abrasion) is desirably greater than 100 degrees and smaller than the water contact angle θ1.

[0071] The reduction rate of the water contact angle of the surface of the hard coating layer 12 before and after abrasion is preferably less than 13%, and more preferably 7.6% or less. A low reduction rate of the water contact angle means that the hard coating layer 12 is hardly scraped off even when subjected to an abrasion test, that is, it has excellent abrasion resistance. Here, the reduction rate of the water contact angle is calculated by the formula: (water contact angle before abrasion test-water contact angle after abrasion test)÷water contact angle before abrasion test×100.

[0072] The water contact angle can be measured, for example, using an automatic contact angle meter DM-501Hi manufactured by Kyowa Interface Science Co., Ltd.

[0073] (IV) Visible scratches After the abrasion test was performed on the hard coating layer 12 according to this embodiment, no visible scratches were found on the hard coating layer 12. That is, it is found that in the hard coat film 10 according to this embodiment, the hard coating layer 12 is less susceptible to scratches and has excellent abrasion resistance.

[0074] [3. Manufacturing Equipment for Hard Coat Film 10] Fig. 4 is a schematic diagram showing a film manufacturing apparatus 100 according to this embodiment. As shown in Fig. 4, the film manufacturing apparatus 100 includes a delivery roll 110, a take-up roll 112, guide rolls 114a-114d, a coating device 120, a drying device 130, and a curing device 140. In Fig. 4, the solid arrows indicate the rotation direction of the rolls. In Fig. 4, the dashed arrows indicate the transport direction of the substrate 11.

[0075] A strip-shaped base material 11 is wound in a roll shape around the delivery roll 110. The delivery roll 110 is disposed so as to be able to continuously deliver the base material 11 by means of a guide roll 114a or the like.

[0076] The take-up roll 112 is disposed so as to be able to take up the strip-shaped hard coat film 10 produced by the film production apparatus 100 .

[0077] The guide rolls 114a to 114d are arranged on a transport path in the film production apparatus 100 so as to be capable of transporting the belt-shaped substrate 11 and the belt-shaped hard-coated film 10. The material of the guide rolls 114a to 114b is appropriately selected according to the desired roll characteristics. The material of the guide rolls 114a to 114b is, for example, a metal such as stainless steel, rubber, silicone resin, or the like.

[0078] Coating device 120 is provided between guide roll 114a and guide roll 114b. Coating device 120 laminates (for example, coats) a resin composition on substrate 11. Coating device 120 is, for example, a gravure coater, a wire bar coater, a die coater, or the like.

[0079] The drying device 130 is provided between the guide roll 114b and the guide roll 114c. The drying device 130 heats the substrate 11 on which the resin composition is applied, to dry the resin composition. The drying device 130 vaporizes the solvent contained in the resin composition. This removes the solvent from the resin composition.

[0080] The curing device 140 is provided between the guide roll 114c and the guide roll 114d. The curing device 140 includes guide rolls 144 and 146 and a light source 148 that irradiates the resin composition with energy rays. The energy rays are, for example, electron beams, ultraviolet rays, visible light rays, gamma rays, etc. The guide rolls 144 and 146 come into contact with the back surface of the substrate 11 on which the resin composition is applied, and send the substrate 11 in the direction of the guide roll 114d.

[0081] Next, a method for manufacturing the hard coat film 10 using the film manufacturing apparatus 100 will be described. First, the substrate 11 is sent out from the sending roll 110. The sent out substrate 11 passes under the coating device 120 via the guide roll 114a. The coating device 120 applies a resin composition onto the substrate 11 passing under the coating device 120. The substrate 11 to which the resin composition has been applied is transported to the drying device 130 via the guide roll 114b. The drying device 130 dries the resin composition applied onto the substrate 11.

[0082] The substrate 11 on which the dried resin composition is laminated is transported via a guide roll 114c to a curing device 140, where the resin composition is irradiated with energy rays from a light source 148. This causes the resin composition to cure, and a hard coat film 10 in which a hard coating layer 12 is laminated on the substrate 11 is produced.

[0083] The hard coat film 10 thus produced is taken up by the take-up roll 112 via guide rolls 146 and 114d.

[0084] It is preferable that the resin composition contains a fluorine compound, so that when the solvent is evaporated by the drying device 130, the fluorine compound can be caused to float on the resin composition as the solvent dries and rises, thereby forming the stain-resistant layer 13.

[0085] The antifouling layer 13 may be formed by laminating a layer containing a fluorine compound separately after forming the hard coating layer 12. FIG. 3 is a cross-sectional view showing another hard coat film 10 according to the present embodiment. As shown in FIG. 3, the antifouling layer 13 may be a layer separate from the hard coating layer 12. In this case, the antifouling layer 13 is formed on the hard coating layer 12. When the antifouling layer 13 is formed in a separate process, it can be formed by a coating method, a vapor deposition method, a sputtering method, or the like. When the coating method is used, an apparatus similar to the film manufacturing apparatus 100 can be used. Thus, the antifouling layer 13 may be a part of the hard coating layer 12, or may be a layer separate from the hard coating layer 12. EXAMPLES

[0086] Examples of the present invention and comparative examples will be specifically described below. Note that the examples shown below are merely examples, and the hard coat film according to the present invention is not limited to the following examples.

[0087] As the hard coating layer and the antifouling layer, Examples 1 to 13 and Comparative Examples 1 to 8 were prepared. In addition, in preparing the hard coating layer and the antifouling layer, a resin composition containing a resin (A), a resin (B), an energy ray-activated polymerization initiator, a solvent, and a fluorine compound was prepared. The compositions of the resin compositions of Examples 1 to 5 are shown in Table 1 below. The compositions of the resin compositions of Examples 6 to 10 are shown in Table 2 below. The compositions of the resin compositions of Examples 11 to 13 are shown in Table 3 below. The compositions of the resin compositions of Comparative Examples 1 to 5 are shown in Table 4 below. The compositions of the resin compositions of Comparative Examples 6 to 8 are shown in Table 5 below. The unit of the compounding ratio in Tables 1 to 5 is mass%.

[0088] In addition, the glass transition temperature Tg, loss tangent tan δ (tan Delta, peak) at the glass transition temperature Tg, number of foldings, water contact angle (WCA) before and after abrasion testing, and visible scratches were measured for the hard coat films of Examples 1 to 13 and Comparative Examples 1 to 8.

[0089] The glass transition temperature Tg and the loss tangent tan δ at the glass transition temperature Tg were measured using a viscoelasticity measuring device DMA7100 manufactured by Hitachi High-Tech Science Corp. The measurement conditions for the dynamic viscoelasticity measurement when calculating the loss tangent tan δ were the same as those in the above embodiment.

[0090] The number of times of folding was measured using a folding test device manufactured by Yuasa System Equipment Co., Ltd. (mandrel diameter 3 mm, bending radius 1.5 mm). In Tables 1 to 5, the folding test results are evaluated on a three-level scale. In Tables 1 to 5, a rating of "3" indicates that there is no change even after 200,000 folds, i.e., the evaluation is very good. In Tables 1 to 5, a rating of "2" indicates that there is no change even after 100,000 folds, i.e., the evaluation is within the acceptable range. In Tables 1 to 5, a rating of "1" indicates that there is a change before 100,000 folds, i.e., the evaluation is poor.

[0091] The water contact angle was measured by dropping 2.0 μL of pure water onto the surface of the hard coat film according to each experimental example before and after abrasion using an abrasion tester using steel wool. The abrasion conditions for the surface of the hard coat film were: load: 1000 g, speed: 50 mm / sec, reciprocating distance: 40 mm, and number of reciprocations: 2500. The water contact angle was measured 10 times at the center of the abraded area, and the average value was calculated. The water contact angles shown in Tables 1 to 5 below are average values. The water contact angles were measured using an automatic contact angle meter DM-501Hi manufactured by Kyowa Interface Science Co., Ltd.

[0092] After the abrasion test, the hard coat film of each experimental example was visually inspected to see whether scratches were formed on the surface.

[0093] [Table 1]

[0094] [Example 1] As shown in Table 1, the resin composition of Example 1 contains 5.64 mass% of SARTOMER's "SR833S" and 22.56 mass% of DAICEL-ALLNEX LTD.'s "DPHA" as resin (A), 9.4 mass% of SARTOMER's "CN989" as resin (B), 5.64 mass% of IGM RESINS' "OMNIRAD500" and 1.41 mass% of IGM RESINS' "OMNIRAD TPO" as energy ray activated polymerization initiators, 46.984 mass% of SIGMA-ALDRICH's "PGME" as a solvent, 7.52 mass% of NANOPHASE TECHNOLOGIES CORPORATION's "AL2260" as metal oxide nanoparticles, and 0.846 mass% of Shin-Etsu Chemical Co., Ltd.'s "KY-1203" as a fluorine compound.

[0095] Here, "AL2260" contains 30% by mass of alumina particles and 70% by mass of a bifunctional monomer (TPGDA). Therefore, the "weighted average of functionality" and the content ratio of resin (A) to resin (B) (hereinafter referred to as "A / B") of Examples 1 to 13 and Comparative Examples 1 to 8 shown in Tables 1 to 5 reflect the content of the bifunctional monomer.

[0096] In Example 1, the weighted average functionality of resin (A) is 4.70, and A / B is 3.56 times.

[0097] In Example 1, the glass transition temperature Tg was 60.4° C. The loss tangent tan δ at the glass transition temperature Tg was 0.1046.

[0098] In the folding test of Example 1, the hard coat film was folded 200,000 times without any change (evaluation "3"). In Example 1, the water contact angle before the abrasion test was 114.7 degrees, and the water contact angle after the abrasion test was 106 degrees. No visible scratches were observed.

[0099] [Example 2] As shown in Table 1, the resin composition of Example 2 contains 7.52 mass% of "SR833S" and 22.56 mass% of "DPHA" as resin (A), and 7.52 mass% of "CN989" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Example 2 are the same as those of Example 1.

[0100] In Example 2, the weighted average functionality of resin (A) is 4.55, and A / B is 4.70 times.

[0101] In Example 2, the glass transition temperature Tg was 54.4° C. The loss tangent tan δ at the glass transition temperature Tg was 0.1126.

[0102] In the folding test of Example 2, the hard coat film was folded 200,000 times without any change. In Example 2, the water contact angle before the abrasion test was 115.2 degrees, and the water contact angle after the abrasion test was 100.8 degrees. No visible scratches were observed.

[0103] [Example 3] As shown in Table 1, the resin composition of Example 3 contains 7.52 mass% of "SR833S" and 18.8 mass% of "DPHA" as resin (A), and 11.28 mass% of "CN989" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Example 3 are the same as those in Example 1.

[0104] In Example 3, the weighted average functionality of resin (A) is 4.38, and A / B is 2.80 times.

[0105] In Example 3, the glass transition temperature Tg was 68.5° C. The loss tangent tan δ at the glass transition temperature Tg was 0.1246.

[0106] In the folding test of Example 3, the hard coat film was folded 200,000 times without any change. In Example 3, the water contact angle before the abrasion test was 113.4 degrees, and the water contact angle after the abrasion test was 105.1 degrees. No visible scratches were observed.

[0107] [Example 4] As shown in Table 1, the resin composition of Example 4 contains 9.4 mass% of "SR833S" and 20.68 mass% of "DPHA" as resin (A), and 7.52 mass% of "CN989" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Example 4 are the same as those in Example 1.

[0108] In Example 4, the weighted average functionality of resin (A) is 4.34, and A / B is 4.70 times.

[0109] In Example 4, the glass transition temperature Tg was 68.5° C. The loss tangent tan δ at the glass transition temperature Tg was 0.1274.

[0110] In the folding test of Example 4, the hard coat film was folded 200,000 times without any change. In Example 4, the water contact angle before the abrasion test was 113.4 degrees, and the water contact angle after the abrasion test was 106.7 degrees. No visible scratches were observed.

[0111] [Example 5] As shown in Table 1, the resin composition of Example 5 contains 5.64 mass% of "SR833S" and 24.44 mass% of "DPHA" as resin (A), and 7.52 mass% of "CN989" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Example 5 are the same as those in Example 1.

[0112] In Example 5, the weighted average functionality of resin (A) is 4.77, and A / B is 4.70 times.

[0113] In Example 5, the glass transition temperature Tg was 76.8° C. The loss tangent tan δ at the glass transition temperature Tg was 0.1017.

[0114] In the folding test of Example 5, the hard coat film was folded 200,000 times without any change. In Example 5, the water contact angle before the abrasion test was 113.4 degrees, and the water contact angle after the abrasion test was 106.5 degrees. No visible scratches were observed.

[0115] [Table 2]

[0116] [Example 6] As shown in Table 2, the resin composition of Example 6 contains 9.4 mass% of "SR833S" and 18.8 mass% of "DPHA" as resin (A), and 9.4 mass% of "CN989" as resin (B). The energy beam-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Example 6 are the same as those in Example 1.

[0117] In Example 6, the weighted average functionality of resin (A) is 4.25, and A / B is 3.56 times.

[0118] In Example 6, the glass transition temperature Tg was 73.4° C. The loss tangent tan δ at the glass transition temperature Tg was 0.1125.

[0119] In addition, in the folding test of Example 6, the hard coat film was folded 200,000 times, but no change occurred. In Example 6, the water contact angle before the abrasion test was 113.4 degrees, and the water contact angle after the abrasion test was 107.3 degrees. No visible scratches were observed.

[0120] [Example 7] As shown in Table 2, the resin composition of Example 7 contains 5.64 mass% of "SR833S" and 20.68 mass% of "DPHA" as resin (A), and 11.28 mass% of "CN989" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Example 7 are the same as those in Example 1.

[0121] In Example 7, the weighted average functionality of resin (A) is 4.62, and A / B is 2.80 times.

[0122] In Example 7, the glass transition temperature Tg was 50.6° C. The loss tangent tan δ at the glass transition temperature Tg was 0.1152.

[0123] In the folding test of Example 7, the hard coat film was folded 200,000 times without any change. In Example 7, the water contact angle before the abrasion test was 113.2 degrees, and the water contact angle after the abrasion test was 102.3 degrees. No visible scratches were observed.

[0124] [Example 8] As shown in Table 2, the resin composition of Example 8 contains 4.7 mass% of "SR833S" and 25.38 mass% of "DPHA" as resin (A), and 7.52 mass% of "CN989" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Example 8 are the same as those in Example 1.

[0125] In Example 8, the weighted average functionality of resin (A) is 4.87, and A / B is 4.70 times.

[0126] In Example 8, the glass transition temperature Tg was 58.3° C. The loss tangent tan δ at the glass transition temperature Tg was 0.0912.

[0127] In the folding test of Example 8, the hard coat film was folded 200,000 times without any change. In Example 8, the water contact angle before the abrasion test was 114.5 degrees, and the water contact angle after the abrasion test was 105.6 degrees. No visible scratches were observed.

[0128] [Example 9] As shown in Table 2, the resin composition of Example 9 contains 3.76 mass% of "SR833S" and 26.32 mass% of "DPHA" as resin (A), and 7.52 mass% of "CN989" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Example 9 are the same as those in Example 1.

[0129] In Example 9, the weighted average functionality of resin (A) is 4.98, and A / B is 4.70 times.

[0130] In Example 9, the glass transition temperature Tg was 91.7° C. The loss tangent tan δ at the glass transition temperature Tg was 0.1003.

[0131] In the folding test of Example 9, the hard coat film was folded 200,000 times without any change. In Example 9, the water contact angle before the abrasion test was 115.8 degrees, and the water contact angle after the abrasion test was 107.1 degrees. No visible scratches were observed.

[0132] [Example 10] As shown in Table 2, the resin composition of Example 10 contains 2.82 mass% of "SR833S" and 27.26 mass% of "DPHA" as resin (A), and 7.52 mass% of "CN989" as resin (B). The energy ray-activatable polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Example 10 are the same as those in Example 1.

[0133] In Example 10, the weighted average functionality of resin (A) is 5.09, and A / B is 4.70 times.

[0134] In Example 10, the glass transition temperature Tg was 85.3° C. The loss tangent tan δ at the glass transition temperature Tg was 0.1007.

[0135] In the folding test of Example 10, the hard coat film was folded 200,000 times without any change. In Example 10, the water contact angle before the abrasion test was 116.1 degrees, and the water contact angle after the abrasion test was 109.6 degrees. No visible scratches were observed.

[0136] [Table 3]

[0137] [Example 11] As shown in Table 3, the resin composition of Example 11 contains 5.64 mass% of "SR833S" and 27.26 mass% of "DPHA" as resin (A), and 4.7 mass% of "CN989" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Example 11 are the same as those in Example 1.

[0138] In Example 11, the weighted average functionality of resin (A) is 4.86, and A / B is 8.12 times.

[0139] In Example 11, the glass transition temperature Tg was 58.3° C. The loss tangent tan δ at the glass transition temperature Tg was 0.0912.

[0140] In the folding test of Example 11, the hard coat film was folded 200,000 times without any change. In Example 11, the water contact angle before the abrasion test was 116.7 degrees, and the water contact angle after the abrasion test was 110.2 degrees. No visible scratches were observed.

[0141] [Example 12] As shown in Table 3, the resin composition of Example 12 contains 8.064 mass% of "SR833S" and 24.192 mass% of "DPHA" as resin (A), 8.064 mass% of "CN929" from SARTOMER as resin (B), 1.613 mass% of "OMNIRAD 184" from IGM RESINS as an energy ray-activated polymerization initiator, 49.693 mass% of "PGME" as a solvent, 8.064 mass% of "AL2260" as metal oxide nanoparticles, and 0.31 mass% of "KY-1203" as a fluorine compound.

[0142] In Example 12, the weighted average functionality of resin (A) is 4.55, and A / B is 4.70 times.

[0143] In Example 12, the glass transition temperature Tg was 69.4° C. The loss tangent tan δ at the glass transition temperature Tg was 0.09.

[0144] In the folding test of Example 12, the hard coat film was folded more than 250,000 times and no change occurred. In Example 12, the water contact angle before the abrasion test was 115.3 degrees, and the water contact angle after the abrasion test was 107.7 degrees. No visible scratches were observed.

[0145] [Example 13] As shown in Table 3, the resin composition of Example 13 contains 8.014 mass% of "SR833S" and 22.04 mass% of "DPHA" as resin (A), 10.02 mass% of "CN989" as resin (B), 1.603 mass% of "OMNIRAD 184" as an energy ray-activated polymerization initiator, 50 mass% of "PGME" as a solvent, 8.014 mass% of "AL2260" as metal oxide nanoparticles, and 0.31 mass% of "KY-1203" as a fluorine compound.

[0146] In Example 13, the weighted average functionality of resin (A) is 4.47, and A / B is 3.56 times.

[0147] In Example 13, the glass transition temperature Tg was 80° C. The loss tangent tan δ at the glass transition temperature Tg was 0.099.

[0148] In the folding test of Example 13, the hard coat film was folded more than 250,000 times without any change. In Example 13, the water contact angle before the abrasion test was 114.9 degrees, and the water contact angle after the abrasion test was 105.9 degrees. No visible scratches were observed.

[0149] As described above, in Examples 1 to 13, the weighted average functional group of the resin (A) is 4 or more. Therefore, the glass transition temperature Tg of Examples 1 to 13 is in the range of 50°C to 100°C, and the loss tangent tanδ at the glass transition temperature Tg is in the range of 0.07 to 0.15. Therefore, it is presumed that the number of folding times of Examples 1 to 13 was 200,000 or more. It is presumed that the water contact angle before the abrasion test of Examples 1 to 13 was larger than 110 degrees, and the water contact angle after the abrasion test was larger than 100 degrees. It is presumed that the reduction rate of the water contact angle after the abrasion test with respect to the water contact angle before the abrasion test was less than 13% in Examples 1 to 13. It is presumed that no visible scratches were confirmed in Examples 1 to 13. In other words, it was confirmed that Examples 1 to 13 have the performance to withstand repeated folding many times, and that it is possible to improve the scratch resistance and abrasion resistance even in a high-temperature environment such as inside a vehicle.

[0150] [Table 4]

[0151] [Comparative Example 1] As shown in Table 4, the resin composition of Comparative Example 1 contains 7.515 mass% of "SR833S" as resin (A), 5.01 mass% of "SR306 (TPGDA)" by SARTOMER, and 9.018 mass% of "DPHA", 16.032 mass% of "CN929" as resin (B), 2.004 mass% of "OMNIRAD 184" as an energy ray-activated polymerization initiator, 50.09 mass% of "PGME" as a solvent, 10.02 mass% of "AL2460" by NANOPHASE TECHNOLOGIES CORPORATION as metal oxide nanoparticles, and 0.31 mass% of "KY-1203" as a fluorine compound.

[0152] In Comparative Example 1, the weighted average functionality of the resin (A) is 2.77, and A / B is 1.78 times.

[0153] In Comparative Example 1, the glass transition temperature Tg was 59.5° C. The loss tangent tan δ at the glass transition temperature Tg was 0.1516.

[0154] In the folding test of Comparative Example 1, the film was folded over 250,000 times without any change. The water contact angle before the abrasion test was 115 degrees, and the water contact angle after the abrasion test was 106 degrees. However, visible scratches were observed.

[0155] As described above, in Comparative Example 1, the weighted average functional group of the resin (A) contained in the resin composition is 2.77. Therefore, the loss tangent tanδ at the glass transition temperature Tg of Comparative Example 1 is high at 0.1516, and the flexibility of the film is slightly low. For this reason, it is presumed that visible scratches were confirmed in Comparative Example 1.

[0156] [Comparative Example 2] As shown in Table 4, the resin composition of Comparative Example 2 contains 16.65 mass% of SARTOMER's "SR444" as resin (A), 30.91 mass% of MIWON SPECIALTY CHEMICAL's "PU610" as resin (B), 2.37 mass% of "OMNIRAD 184" as an energy ray activated polymerization initiator, 49.76 mass% of "PGME" as a solvent, and 0.31 mass% of "KY-1203" as a fluorine compound. The resin composition of Comparative Example 2 does not contain metal oxide nanoparticles. "SR444" is a monomer containing 4 functional groups with 3 functional groups as the main component.

[0157] In Comparative Example 2, the weighted average functionality of the resin (A) is 3.00, and A / B is 0.54 times.

[0158] In Comparative Example 2, the glass transition temperature Tg was 100° C. The loss tangent tan δ at the glass transition temperature Tg was 0.055.

[0159] In the folding test of Comparative Example 2, cracks were generated in the sample during the process of folding the film 100 times. In Comparative Example 2, the water contact angle before the abrasion test was 110 degrees, and the water contact angle after the abrasion test was 95 degrees. No visible scratches were observed.

[0160] As described above, in Comparative Example 2, the weighted average functional group of the resin (A) contained in the resin composition is 3.00. Therefore, the loss tangent tanδ at the glass transition temperature Tg of Comparative Example 2 is low at 0.055, and the hardness of the film is too high. For this reason, it is presumed that the number of folding times of Comparative Example 2 was 100 times or less. In general, in Comparative Example 2, the crosslink density was increased to increase the scratch resistance, so no scratches were observed, but on the other hand, it is considered that the crosslink density was increased too much, resulting in no flexibility and no good results in the folding test.

[0161] [Comparative Example 3] As shown in Table 4, the resin composition of Comparative Example 3 contains 7.35 mass% of "SR444" as resin (A), 24.51 mass% of "IBOA (SR506-A)" by SARTOMER, 9.81 mass% of "CN9047" by SARTOMER as resin (B), 0.98 mass% of "OMNIRAD 184" as an energy beam-activated polymerization initiator, 49.75 mass% of "PGME" as a solvent, 7.35 mass% of "AL2260" as metal oxide nanoparticles, and 0.25 mass% of "KY-1203" as a fluorine compound. Here, "IBOA (SR506-A)" is a monofunctional monomer.

[0162] In Comparative Example 3, the weighted average functionality of the resin (A) is 1.54, and A / B is 3.77 times.

[0163] In Comparative Example 3, the glass transition temperature Tg was 129.6° C. The loss tangent tan δ at the glass transition temperature Tg was 0.25.

[0164] In the folding test of Comparative Example 3, there was no change even after the film was folded 200,000 times. However, in Comparative Example 3, the water contact angle before the abrasion test was 113.4 degrees, and the water contact angle after the abrasion test was 87.3 degrees. Visible scratches were confirmed.

[0165] As described above, in Comparative Example 3, the weighted average functional group of the resin (A) contained in the resin composition is 1.54. Therefore, the glass transition temperature Tg of Comparative Example 3 was high at 129.6°C. The loss tangent tanδ at the glass transition temperature Tg of Comparative Example 3 was high at 0.25. That is, in Comparative Example 3, the crosslink density was low due to the high tanδ, and since it had flexibility, it showed good results in the folding test, but on the other hand, since the hardness was too low, it is presumed that visible scratches were confirmed after the abrasion test.

[0166] [Comparative Example 4] As shown in Table 4, the resin composition of Comparative Example 4 contains 7.35 mass% of "SR444" and 22.06 mass% of "IBOA (SR506-A)" as resin (A), and 12.26 mass% of "CN9047" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Comparative Example 4 are the same as those of Comparative Example 3.

[0167] In Comparative Example 4, the weighted average functionality of the resin (A) is 1.57, and A / B is 2.82 times.

[0168] In Comparative Example 4, the glass transition temperature Tg was 117.8° C. The loss tangent tan δ at the glass transition temperature Tg was 0.208.

[0169] In the folding test of Comparative Example 4, there was no change even after the film was folded 200,000 times. However, in Comparative Example 4, the water contact angle before the abrasion test was 113.7 degrees, and the water contact angle after the abrasion test was 73.9 degrees. Visible scratches were confirmed.

[0170] As described above, in Comparative Example 4, the weighted average functional group of the resin (A) contained in the resin composition is 1.57. Therefore, the glass transition temperature Tg of Comparative Example 4 was high at 117.8°C. The loss tangent tanδ at the glass transition temperature Tg of Comparative Example 4 was high at 0.208. That is, in Comparative Example 4, the crosslink density was low due to the high tanδ, and since it had flexibility, it showed good results in the folding test, but on the other hand, since the hardness was too low, it is presumed that visible scratches were confirmed after the abrasion test.

[0171] [Comparative Example 5] As shown in Table 4, the resin composition of Comparative Example 5 contains 7.35 mass% of "SR444" and 19.61 mass% of "IBOA (SR506-A)" as resin (A), and 14.71 mass% of "CN9047" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Comparative Example 5 are the same as those of Comparative Example 3.

[0172] In Comparative Example 5, the weighted average functionality of the resin (A) is 1.62, and A / B is 2.18 times.

[0173] In Comparative Example 5, the glass transition temperature Tg was 106.3° C. The loss tangent tan δ at the glass transition temperature Tg was 0.194.

[0174] In the folding test of Comparative Example 5, the film was folded 200,000 times without any change. However, in Comparative Example 5, the water contact angle before the abrasion test was 114.1 degrees, and the water contact angle after the abrasion test was 76.1 degrees. Visible scratches were confirmed.

[0175] As described above, in Comparative Example 5, the weighted average functional group of the resin (A) contained in the resin composition is 1.62. Therefore, the glass transition temperature Tg of Comparative Example 5 was high at 106.3°C. The loss tangent tanδ at the glass transition temperature Tg of Comparative Example 5 was high at 0.194. That is, in Comparative Example 5, the crosslink density was low due to the high tanδ, and since it had flexibility, it showed good results in the folding test, but on the other hand, the hardness was too low, so it is presumed that visible scratches were confirmed after the abrasion test.

[0176] [Table 5]

[0177] [Comparative Example 6] As shown in Table 5, the resin composition of Comparative Example 6 contains 4.9 mass% of "SR444" and 24.51 mass% of "IBOA (SR506-A)" as resin (A), and 12.26 mass% of "CN9047" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Comparative Example 6 are the same as those of Comparative Example 3.

[0178] In Comparative Example 6, the weighted average functionality of the resin (A) is 1.43, and A / B is 2.82 times.

[0179] In Comparative Example 6, the glass transition temperature Tg was 111.9° C. The loss tangent tan δ at the glass transition temperature Tg was 0.2791.

[0180] In the folding test of Comparative Example 6, the film was folded 200,000 times without any change. However, in Comparative Example 6, the water contact angle before the abrasion test was 113.5 degrees, and the water contact angle after the abrasion test was 77.4 degrees. Visible scratches were confirmed.

[0181] As described above, in Comparative Example 6, the weighted average functional group of the resin (A) contained in the resin composition is 1.43. Therefore, the glass transition temperature Tg of Comparative Example 6 was high at 111.9°C. The loss tangent tanδ at the glass transition temperature Tg of Comparative Example 6 was high at 0.2791. That is, in Comparative Example 6, the crosslink density was low due to the high tanδ, and since it had flexibility, it showed good results in the folding test, but on the other hand, the hardness was too low, so it is presumed that visible scratches were confirmed after the abrasion test.

[0182] [Comparative Example 7] As shown in Table 5, the resin composition of Comparative Example 7 contains 4.9 mass% of "SR444" and 22.06 mass% of "IBOA (SR506-A)" as resin (A), and 14.71 mass% of "CN9047" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Comparative Example 7 are the same as those of Comparative Example 3.

[0183] In Comparative Example 7, the weighted average functionality of the resin (A) is 1.47, and A / B is 2.18 times.

[0184] In Comparative Example 7, the glass transition temperature Tg was 102.7° C. The loss tangent tan δ at the glass transition temperature Tg was 0.2455.

[0185] In the folding test of Comparative Example 7, the film was folded 200,000 times without any change. However, in Comparative Example 7, the water contact angle before the abrasion test was 113.5 degrees, and the water contact angle after the abrasion test was 70.3 degrees. Visible scratches were confirmed.

[0186] As described above, in Comparative Example 7, the weighted average functional group of the resin (A) contained in the resin composition is 1.47. Therefore, the glass transition temperature Tg of Comparative Example 7 was high at 102.7°C. In addition, the loss tangent tanδ at the glass transition temperature Tg of Comparative Example 7 was high at 0.2455. That is, in Comparative Example 7, the crosslink density was low due to the high tanδ, and since it had flexibility, it showed good results in the folding test, but on the other hand, the hardness was too low, so it is presumed that visible scratches were confirmed after the abrasion test.

[0187] [Comparative Example 8] As shown in Table 5, the resin composition of Comparative Example 8 contains 4.9 mass% of "SR444" and 19.61 mass% of "IBOA (SR506-A)" as resin (A), and 17.16 mass% of "CN9047" as resin (B). The energy ray-activated polymerization initiator, solvent, metal oxide nanoparticles, and fluorine compound contained in the resin composition of Comparative Example 8 are the same as those of Comparative Example 3.

[0188] In Comparative Example 8, the weighted average functionality of the resin (A) is 1.50, and A / B is 1.73 times.

[0189] In Comparative Example 8, the glass transition temperature Tg was 93.2° C. The loss tangent tan δ at the glass transition temperature Tg was 0.2183.

[0190] In the folding test of Comparative Example 8, the film was folded 200,000 times without any change. However, in Comparative Example 8, the water contact angle before the abrasion test was 107 degrees, and the water contact angle after the abrasion test was 65 degrees. Visible scratches were confirmed.

[0191] As described above, in Comparative Example 8, the weighted average functional group of the resin (A) contained in the resin composition is 1.50. Therefore, the loss tangent tan δ at the glass transition temperature Tg of Comparative Example 8 is high at 0.2183, and the hardness is too low. For this reason, it is presumed that the water contact angle after the abrasion test of Comparative Example 8 is low at 65 degrees, and visible scratches were confirmed.

[0192] As described above, according to this embodiment, it is possible to provide a hard coat film 10 that has the performance to withstand repeated folding many times, as well as scratch resistance and abrasion resistance.

[0193] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the invention disclosed in this specification is not limited thereto, and it is clear that various changes and modifications are possible within the scope of the present disclosure and the claims.

[0194] The hard coat film 10 of the present invention can be used as a protective film in any device requiring a protective film, such as the display screen of a display device, a screen, goggles, an eye shield, a face shield, etc. It is particularly suitable for electronic devices such as flexible displays and information terminals that are folded when used (foldable), and any other similar products.

[0195] When the hard coat film 10 of the present invention is used in a display device, the hard coat film 10 may have a functional material layer and / or an adhesive layer for improving visibility. Examples of the functional material layer include a diffusion layer and an anti-reflection layer. Examples of the adhesive layer include an optical elastic resin layer. [Explanation of symbols]

[0196] 10 Hard coat film 11 Base material 12 Hard coating layer 12a 1st area 12b 2nd area 13 Antifouling layer 100 Film manufacturing equipment 110 Delivery roll 112 Winding roll 114a~d Guide roll 120 Coating equipment 130 Drying equipment 140 Curing equipment 144 Guide Roll 146 Guide Roll 148 Light source

Claims

1. A substrate; a hard coating layer formed on the substrate, the hard coating layer being made of a cured product of a resin composition containing a resin (A) and a resin (B); Equipped with The resin (A) is a polyfunctional (meth)acrylic monomer having a weighted average functionality of 4 or more, The resin (B) is an aliphatic urethane acrylate, The glass transition temperature Tg of the hard coating layer is 50° C. or more and 100° C. or less, A hard coat film, wherein when the loss tangent tan δ of the hard coating layer is measured by dynamic viscoelasticity measurement in which a dynamic load of a frequency of 1 Hz is applied, the loss tangent tan δ at the glass transition temperature Tg is 0.07 or more and 0.15 or less.

2. The hard coat film according to claim 1 , wherein the resin composition further comprises metal oxide nanoparticles having an average particle size of 100 nm or less.

3. 3. The hard coat film according to claim 2, wherein the content of the metal oxide nanoparticles in the resin composition is 2% by mass or more and 5% by mass or less based on the total solid content of the resin composition of the hard coating layer.

4. 3. The hard coat film according to claim 2, wherein the metal oxide constituting the metal oxide nanoparticles is either or both of silica and alumina.

5. 3. The hard coat film of claim 2, wherein the metal oxide nanoparticles have a Mohs hardness of greater than 6.

6. 2. The hard coat film according to claim 1, wherein when the surface of the hard coating layer is abraded with steel wool #0000 using an abrasion tester under conditions of a load of 1000 g, a speed of 50 mm / sec, a reciprocating distance of 40 mm, and a number of reciprocating movements of 2500, the water contact angle of the surface of the hard coating layer after abrasion is greater than 100 degrees.

7. 7. The hardcoat film of claim 6, wherein the water contact angle of the surface of the hardcoat layer before abrasion is greater than 110 degrees.

8. 8. The hard coat film according to claim 7, wherein a reduction rate of a water contact angle of the surface of the hard coating layer after abrasion to a water contact angle before abrasion is less than 13%.

9. The hard coat film according to claim 7 , wherein the content of the resin (A) contained in the resin composition is more than 2 times and less than 9 times the content of the resin (B).

10. The content of the resin (A) in the resin composition is 20% by mass or more and 40% by mass or less, The hard coat film according to claim 9 , wherein the content of the resin (B) in the resin composition is 2% by mass or more and 15% by mass or less.

11. 10. The hard coat film of claim 1, wherein the hard coat film is configured to be capable of being folded, either in or out, at least 100,000 times without cracking, delamination, and / or loss of optical properties.

12. 2. The hard coat film according to claim 1, wherein the substrate is a thermoplastic substrate having a thickness of 10 μm or more and 200 μm or less.

13. 2. The hard coat film according to claim 1, wherein the resin composition contains a fluorine compound, and the fluorine compound is segregated in a first region located on the surface side of the hard coating layer.

14. The hard coat film according to claim 13, wherein the segregated fluorine compound has an antifouling function.

15. The hard coat film according to claim 13 , wherein the fluorine compound is segregated on the surface of the hard coating layer.

16. the hard coat film is configured to be capable of being folded, either in or out, at least 100,000 times without loss of the optical properties; The optical properties are one or more selected from the group consisting of total light transmittance (%), transmission haze, gloss, and variation in chromaticity b* (intensity of color from blue to yellow). The hard coat film according to claim 11.

17. The hard coat film according to claim 13 , wherein the fluorine compound is not segregated in a second region located on the substrate side of the hard coating layer.

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