Component for display device and display device

Abstract

The present disclosure provides a member for a display device having a laminate in which an impact-absorbing layer and a hard coat layer are laminated, the member being characterized in that when the tensile stress of the laminate is measured, the impact-absorbing layer and the hard coat layer are bonded to each other, and the impact-absorbing layer and the hard coat layer are bonded to each other. The hard coat layer has a breaking strength of 7 MPa or more and a breaking elongation of 4% to 36% (inclusive), where the stress at the time of breaking of the hard coat layer is defined as the breaking strength of the hard coat layer and the elongation at the time of breaking of the hard coat layer is defined as the breaking elongation of the hard coat layer.

Description

Technical Field

[0001] The present disclosure relates to a component for a display device and a display device. Background Art

[0002] In the past, in display devices, a cover member made of glass or resin was used to protect the display device. The cover member protects the display device from impact or damage, and is required to have strength, impact resistance, damage resistance, etc. The glass cover member has the characteristics of high surface hardness, scratch resistance, high transparency, etc., and the resin cover member has the characteristics of light weight and not easy to break. In addition, generally, the thicker the cover member is, the higher the function of protecting the display device from impact. The material and thickness of the cover member are appropriately selected according to the weight, cost, size of the display device, etc.

[0003] In recent years, the development of flexible displays such as foldable displays, rollable displays, and bendable displays has been actively advanced, and among these, the development of foldable displays, that is, bendable display devices, has been advanced.

[0004] In a bendable display device, the cover part also needs to bend following the movement of the display device, so a bendable cover part is applied. In the case of a resin cover part, a colorless and transparent polyimide or polyamide-imide film has been developed by designing the chemical structure (for example, see Patent Document 1). In addition, in the case of a glass cover part, research is being conducted on cover parts such as ultra-thin glass (UTG) that are bendable by thinning the glass (for example, see Patent Document 2). Among glasses, glass with particularly high bending resistance is called chemically strengthened glass, which internalizes the stress of expansion on the glass surface so that the tiny damage on the glass surface does not increase when bent, making the glass less likely to break.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-137864

[0008] Patent Document 2: Japanese Patent Application Publication No. 2018-188335 Summary of the invention

[0009] Problems to be solved by the invention

[0010] The elastic modulus of glass is higher than that of resin, so when the thickness is the same, the ability to protect the display device is higher than that of resin. In addition, from an optical point of view, the transparency of glass is also high, and a display device with better visibility can be manufactured. On the other hand, by making the glass thinner, it is more likely to break, and the impact resistance deteriorates sharply. If the glass of the cover part breaks due to an impact from the outside, not only will the function of protecting the display device be reduced, but there is also the possibility that the user's fingertips and the like will be injured by the resulting fragments or sharp end faces.

[0011] For the glass substrate, an impact absorbing layer is sometimes provided on the outer surface of the glass substrate to prevent the glass substrate from being broken due to external impact. In this case, a hard coating layer is provided on the surface of the impact absorbing layer opposite to the glass substrate to improve scratch resistance.

[0012] A laminate composed of an impact absorbing layer and a hard coat layer disposed on the outer surface of such a glass substrate is required to have not only excellent impact resistance and scratch resistance but also bending resistance when used in a flexible display. However, it is extremely difficult to obtain a laminate having these three properties in a well-balanced manner.

[0013] The present disclosure has been made in view of the above-mentioned actual situation, and a main object of the present disclosure is to provide a member for a display device having excellent impact resistance, scratch resistance, and bending resistance.

[0014] Means for solving problems

[0015] In order to solve the above-mentioned problems, the inventors of the present invention conducted in-depth research and found that when measuring the tensile stress of the above-mentioned stack, the hard coating layer breaks first, and when the stress and elongation at this time are set to a specified range, a component for a display device with excellent impact resistance, abrasion resistance and bending resistance is produced, thereby completing the present invention.

[0016] That is, the present disclosure provides a component for a display device, which is a component for a display device having a stacked body formed by stacking an impact absorbing layer and a hard coating layer, wherein, when measuring the tensile stress of the above-mentioned stacked body, when the stress when the above-mentioned hard coating layer breaks is set as the breaking strength of the hard coating layer, and the elongation when the above-mentioned hard coating layer breaks is set as the breaking elongation of the hard coating layer, the breaking strength of the above-mentioned hard coating layer is greater than 7 MPa, and the breaking elongation of the above-mentioned hard coating layer is greater than 4% and less than 36%.

[0017] In the display device member of the present disclosure, it is preferred that the hard coat layer have an elongation at break of less than 30%.

[0018] In the display device member of the present disclosure, it is preferable that a glass substrate having a thickness of 100 μm or less is disposed on the surface of the impact absorbing layer opposite to the hard coating layer.

[0019] Another embodiment of the present disclosure provides a display device including a display panel and the above-mentioned display device component disposed on the viewer side of the display panel.

[0020] In the present disclosure, the display device is preferably foldable in terms of exerting the effect.

[0021] Effects of the Invention

[0022] In the present disclosure, there is an effect of being able to provide a member for a display device having excellent impact resistance, scratch resistance, and bending resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 : is a schematic cross-sectional view illustrating a laminate used in the present disclosure.

[0024] Figure 2 It is a schematic cross-sectional view illustrating a member for a display device in the present disclosure.

[0025] Figure 3 It is a schematic cross-sectional view illustrating a member for a display device in the present disclosure.

[0026] Figure 4 It is a schematic cross-sectional view illustrating a member for a display device in the present disclosure.

[0027] Figure 5 is a schematic cross-sectional view illustrating a display device in the present disclosure.

[0028] Figure 6 : is a schematic cross-sectional view explaining the bending resistance test in the present disclosure.

[0029] Figure 7 This is a graph summarizing the comprehensive evaluation results of Examples and Comparative Examples. DETAILED DESCRIPTION

[0030] Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings, etc. Among them, the present invention can be implemented in a variety of different ways, and is not to be construed as being limited to the contents of the embodiments illustrated below. In addition, in order to make the description clearer, the drawings sometimes schematically represent the width, thickness, shape, etc. of each part compared to the actual situation, but it is always an example and does not limit the interpretation of the present invention. In addition, in this specification and the drawings, the same reference numerals are given to the same elements as those in the drawings that have appeared, and the detailed description is sometimes appropriately omitted.

[0031] In this specification, when describing a method of arranging another component above a certain component, if it is simply described as "above" or "below", unless otherwise stated, it includes both the case where the other component is arranged directly above or directly below in a manner of contacting the certain component, and the case where the other component is arranged above or below the certain component with another component further interposed therebetween. In addition, in this specification, when describing a method of arranging another component on the surface of a certain component, if it is simply described as "surface side" or "surface", unless otherwise stated, it includes both the case where the other component is arranged directly above or directly below in a manner of contacting the certain component, and the case where the other component is arranged above or below the certain component with another component further interposed therebetween.

[0032] In addition, in this specification, a "film" also includes a member called a "sheet".

[0033] Hereinafter, the display device component and the display device in the present disclosure will be described in detail.

[0034] A. Display device components

[0035] The component for a display device in the present disclosure is a component for a display device having a stacked body formed by stacking an impact absorbing layer and a hard coating layer, and is characterized in that, when measuring the tensile stress of the above-mentioned stacked body, the stress when the above-mentioned hard coating layer breaks is set as the hard coating layer breaking strength (hereinafter sometimes referred to as the HC breaking strength), and the elongation when the above-mentioned hard coating layer breaks is set as the hard coating layer breaking elongation (hereinafter sometimes referred to as the HC breaking elongation), the above-mentioned HC breaking strength is 7 MPa or more, and the above-mentioned HC breaking elongation is 4% or more and 36% or less.

[0036] Figure 1 Schematic cross-sectional view showing an example of a laminate used in a display device component in the present disclosure. Figure 1 As shown, the laminate 4 has an impact absorbing layer 2 and a hard coating layer 3 disposed on one surface side of the impact absorbing layer 2. When the tensile stress of the laminate 4 having the impact absorbing layer 2 and the hard coating layer 3 is measured, the hard coating layer 3 breaks first, but in the present disclosure, the strength and elongation of the laminate 4 when the hard coating layer 3 breaks are within a specified range.

[0037] Figure 2 An example of a display device member 1 of the present disclosure is shown. The display device member 1 includes a laminate 4 and a glass substrate 5 on the surface of the laminate 4 opposite to the hard coating layer 3 of the impact absorbing layer 2 .

[0038] In the present disclosure, the HC elongation at break of 4% or more and 36% or less means that, when the laminate is stretched to measure the tensile stress, both the hard coating layer and the impact absorbing layer are stretched, but the hard coating layer having higher rigidity and thinner thickness breaks first. The HC elongation at break refers to the elongation when the hard coating layer breaks, and the laminate in the present disclosure is characterized in that the elongation of the laminate when the hard coating layer breaks is 4% or more and 36% or less.

[0039] Since the HC breaking elongation of the laminated body of the present disclosure is within the above range, the rigidity of the hard coat layer is within an appropriate range, and thus the laminated body having excellent scratch resistance and bending resistance can be obtained.

[0040] That is, when the HC elongation at break is less than 4%, it means that the rigidity of the hard coating layer is too high. Therefore, when the laminate is bent, whether it is bent outward or inward, a large shear stress is applied to the hard coating layer at the bent portion. Therefore, cracks and wrinkles are generated in the hard coating layer, and there is a high possibility that the appearance of the laminate is poor when used as a foldable display device, for example.

[0041] On the other hand, when the HC elongation at break exceeds 36%, the hard coat layer is not rigid enough and the surface becomes relatively soft, so the scratch resistance is reduced. Therefore, when the laminate is used as a display device, the surface is easily scratched during use.

[0042] In addition, in the laminate used in the display device member of the present disclosure, the HC fracture strength of 7 MPa or more also refers to the strength when the hard coating layer breaks (tensile stress of the laminate), and refers to the tensile stress of the impact absorbing layer when it breaks. The laminate in the present disclosure is characterized in that the tensile stress of the impact absorbing layer when the hard coating layer breaks is 7 MPa or more.

[0043] Since the HC breaking strength of the laminated body is within the above range, it means that the impact absorbing layer is harder, and thus the impact resistance based on the pen drop test can be improved.

[0044] 1. Characteristics of the laminate

[0045] Hereinafter, the characteristics of the laminated body in the present disclosure will be described.

[0046] (1) HC elongation at break

[0047] The lower limit of the HC elongation at break of the laminate in the present disclosure is 4% or more, may be 6% or more, and preferably 7% or more. On the other hand, the upper limit is 36% or less, and preferably less than 30%. The specific range of the HC elongation at break is 4% or more and 36%, may be 6% or more and 36% or less, and preferably 6% or more and less than 30%.

[0048] The method for measuring the HC breaking elongation is as follows.

[0049] First, the laminate was cut using an SDL-200 bar cutter equipped with a JIS dumbbell shape No. 3 (manufactured by Dumbbell Co.) to obtain a dumbbell-shaped test piece (total length 100 mm, standard length 20 mm). The test piece was stretched at a speed of 100 mm / min using a Tensilon universal testing machine. The test piece was irradiated with an LED light, and the elongation when only the HC layer cracked (ruptured) was set as a (mm), and the value obtained by the following formula was taken as the HC breaking elongation.

[0050] HC breaking elongation (%) = (a / 20) × 100 (%) (formula)

[0051] In order to obtain the above-mentioned laminated body from a display device member, the laminated body is slowly peeled off from the end surface of the laminated body while being heated in a dryer. When the film is about to break, it can be easily obtained by once cooling it to room temperature and then slowly peeling it off.

[0052] (2) HC fracture strength

[0053] The lower limit of the HC fracture strength of the laminate is 7 MPa or more, preferably 10 MPa or more. On the other hand, the upper limit is preferably 100 MPa or less, and particularly preferably 70 MPa or less. If the HC fracture strength is too large, the HC becomes hard and brittle, and thus the bendability deteriorates. As a specific range, it is preferably 7 MPa or more and 70 MPa or less, and particularly preferably 10 MPa or more and 70 MPa or less.

[0054] The HC breaking strength can be measured by the same method as the above-mentioned HC breaking elongation measurement method.

[0055] (3) Young's modulus of the laminate

[0056] In the present disclosure, in order to improve the impact resistance (pencil drop characteristics), the Young's modulus of the laminate is preferably 90 MPa or more, particularly preferably 290 MPa or more. On the other hand, the upper limit is preferably 3000 MPa or less.

[0057] This is because, if it is below the above range, the rigidity of the impact absorbing layer is insufficient, and the impact resistance (pencil resistance) may be reduced. On the other hand, if it exceeds the above range, problems may arise in terms of bending resistance and the like.

[0058] As a method for measuring the Young's modulus of the laminate, a stress-strain curve was prepared when measuring the HC breaking elongation, and the slope was determined from a range of 0.5% to 1.0% when the strain at a load of 0.01 MPa was set to 0%.

[0059] (4) Film thickness of laminate

[0060] The film thickness of the laminate in the present disclosure is preferably 15 μm to 300 μm, and particularly preferably 40 μm to 200 μm. This is because when it is thinner than the above range, the impact resistance (pencil resistance) may be reduced; when it is thicker than the above range, the properties such as bending resistance may be reduced.

[0061] 2. Configuration of display device components

[0062] The display device member of the present disclosure only needs to include the above-mentioned laminate, and a glass substrate is usually disposed on the impact absorbing layer side of the above-mentioned laminate.

[0063] In the laminate, the impact absorbing layer and the hard coating layer may be arranged adjacent to each other. That is, the impact absorbing layer and the hard coating layer may be in contact or attached via an adhesive layer or the like. In the present disclosure, in consideration of the aspect of forming the hard coating layer by a coating method and the aspect of not requiring an adhesive layer, it is preferred that the impact absorbing layer and the hard coating layer be arranged in a contacting state.

[0064] Hereinafter, each structure of the display device component of the present disclosure will be described.

[0065] (1) Laminated body

[0066] The laminate used in the present disclosure has a shock absorbing layer and a hard coating layer.

[0067] a) Impact absorbing layer

[0068] The material of the impact absorbing layer used in the laminate is not particularly limited as long as it can exhibit the above-mentioned HC breaking elongation and HC breaking strength when laminated with the hard coating layer to form the laminate.

[0069] Specifically, urethane resins, polyethylene terephthalate resins, etc. are mentioned. Among them, urethane resins are preferred because the HC breaking strength can be easily adjusted to the above range by using urethane resins.

[0070] The urethane resin is a resin having a urethane bond. Examples of the urethane resin include a cured product of an ionizing radiation curable urethane resin composition or a cured product of a thermosetting urethane resin composition. Among these, a cured product of an ionizing radiation curable urethane resin composition is preferred because it has high hardness, a fast curing speed, and excellent mass productivity.

[0071] The thermosetting urethane resin may contain, for example, a polyol compound and an isocyanate compound. The polyol compound and the isocyanate compound may be any of a monomer, an oligomer, and a prepolymer.

[0072] The ionizing radiation curable urethane resin composition may contain, for example, urethane (meth)acrylate. The urethane (meth)acrylate may be any of a monomer, an oligomer, and a prepolymer.

[0073] The number of (meth)acryloyl groups (functional group number) in the urethane (meth)acrylate is, for example, preferably 2 or more and 4 or less, and more preferably 2 or more and 3 or less. When the number of (meth)acryloyl groups in the urethane (meth)acrylate is small, the hardness may be reduced. In addition, when the number of (meth)acryloyl groups in the urethane (meth)acrylate is large, the curing shrinkage becomes large, the impact absorbing layer may curl, and cracks may be generated in the impact absorbing layer when it is bent.

[0074] In addition, "(meth)acrylate" means including both "acrylate" and "methacrylate", and "(meth)acryloyl" means including both "acryloyl" and "methacryloyl".

[0075] The weight average molecular weight of carbamate (meth) acrylate is, for example, preferably 1500 or more and 20000 or less, more preferably 2000 or more and 15000 or less. When the weight average molecular weight of carbamate (meth) acrylate is too small, the impact resistance may be reduced. In addition, when the weight average molecular weight of carbamate (meth) acrylate is too large, the viscosity of the ionizing radiation curable carbamate resin composition increases, and the coating property may deteriorate. It should be noted that the weight average molecular weight of carbamate (meth) acrylate refers to the value calculated by polystyrene conversion measured by gel permeation chromatography (GPC).

[0076] When the urethane resin is a cured product of an ionizing radiation curable urethane resin composition, or the ionizing radiation curable urethane resin composition contains urethane (meth) acrylate, the urethane resin contains repeating units having a structure derived from urethane (meth) acrylate. Examples of the repeating units having a structure derived from urethane (meth) acrylate include structures represented by the following general formula (1), (2), (3) or (4).

[0077] [Chemistry 1]

[0078]

[0079] In the above general formula (1), R 1represents a branched alkyl group, R 2 represents a branched alkyl group or a saturated cyclic aliphatic group, R 3 represents a hydrogen atom or a methyl group, R 4 represents a hydrogen atom, a methyl group or an ethyl group, m represents an integer of 0 or greater, and x represents an integer of 0-3.

[0080] [Chemistry 2]

[0081]

[0082] In the above general formula (2), R 1 represents a branched alkyl group, R 2 represents a branched alkyl group or a saturated cyclic aliphatic group, R 3 represents a hydrogen atom or a methyl group, R 4 represents a hydrogen atom, a methyl group or an ethyl group, n represents an integer of 1 or more, and x represents an integer of 0-3.

[0083] [Chemistry 3]

[0084]

[0085] In the above general formula (3), R 1 represents a branched alkyl group, R 2 represents a branched alkyl group or a saturated cyclic aliphatic group, R 3 represents a hydrogen atom or a methyl group, R 4 represents a hydrogen atom, a methyl group or an ethyl group, m represents an integer of 0 or greater, and x represents an integer of 0-3.

[0086] [Chemistry 4]

[0087]

[0088] In the above general formula (4), R 1 represents a branched alkyl group, R 2 represents a branched alkyl group or a saturated cyclic aliphatic group, R 3 represents a hydrogen atom or a methyl group, R 4 represents a hydrogen atom, a methyl group or an ethyl group, n represents an integer of 1 or more, and x represents an integer of 0-3.

[0089] It should be noted that the structure of the polymer chain (repeating unit) of the resin constituting the impact absorbing layer can be determined by analyzing the impact absorbing layer using, for example, pyrolysis gas chromatography mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FT-IR). In particular, pyrolysis GC-MS is useful because it can detect the monomer units contained in the impact absorbing layer as monomer components.

[0090] The impact absorbing layer may contain, for example, an ultraviolet absorber, a spectral transmittance adjuster, an antifouling agent, inorganic particles, a leveling agent, a polymerization initiator, etc. as necessary.

[0091] The Young's modulus of the impact absorbing layer in the present disclosure is not particularly limited as long as the HC fracture strength can be within the above-mentioned specified range and the impact resistance (pen-fall characteristics) can be good. Specifically, it is preferably 50 MPa or more, and particularly preferably 100 MPa or more. On the other hand, as an upper limit, it is preferably 3000 MPa or less, more preferably 900 MPa or less, and particularly preferably 300 MPa or less. As a range, it is preferably 50 MPa or more and 3000 MPa or less, and more preferably 100 MPa or more and 900 MPa or less.

[0092] The Young's modulus of the impact absorbing layer is measured in the same manner as that of the laminate, and thus the description thereof is omitted. It should be noted that the Young's modulus of the laminate is substantially the same as that of the impact absorbing layer alone.

[0093] The thickness of the impact absorbing layer in the present disclosure varies depending on the Young's modulus of the impact absorbing layer, but is not particularly limited as long as the HC breaking strength can be within the above-mentioned predetermined range and the impact resistance (pencil drop characteristics) can be improved.

[0094] Specifically, the lower limit is preferably 10 μm or more, particularly preferably 30 μm or more, and particularly preferably 40 μm or more. On the other hand, the upper limit is preferably 300 μm or less, particularly preferably 200 μm or less.

[0095] The preferred range of thickness is preferably 10 μm or more and 300 μm or less, and more preferably 30 μm or more and 200 μm or less.

[0096] Here, the thickness of the impact absorbing layer may be the average value of the thickness at any 10 locations measured in a cross section in the thickness direction of the display device member observed using a transmission electron microscope (TEM), a scanning electron microscope (SEM), or a scanning transmission electron microscope (STEM). It should be noted that the thickness of other layers included in the display device member may be measured in the same manner.

[0097] The impact absorbing layer used in the present disclosure preferably has a predetermined transparency. Specifically, the total light transmittance of the impact absorbing layer is preferably 85% or more, more preferably 88% or more, and further preferably 90% or more. By making the total light transmittance so high, a component for a display device with good transparency can be made.

[0098] Here, the total light transmittance of the impact absorbing layer can be measured in accordance with JIS K7361-1, for example, using a haze meter HM150 manufactured by Murakami Color Research Laboratory.

[0099] The impact absorbing layer preferably has a haze of 5% or less, more preferably 2% or less, and further preferably 1% or less. By making the haze so low, a display device member having good transparency can be obtained.

[0100] Here, the haze of the impact absorbing layer can be measured in accordance with JIS K-7136, for example, using a haze meter HM150 manufactured by Murakami Color Research Laboratory.

[0101] As the impact absorbing layer, for example, a film-shaped impact absorbing layer can be used. Alternatively, for example, the impact absorbing layer can be formed by coating a composition for an impact absorbing layer on a support.

[0102] b) Hard coating

[0103] The laminated body in the present disclosure has a hard coating layer disposed on the surface of the impact absorbing layer. The hard coating layer is a component for improving the surface hardness. By configuring the hard coating layer, the scratch resistance can be improved. Specifically, the laminated body in the present disclosure preferably shows a hardness of "H" or above when the pencil hardness test specified in JIS K 5600-5-4 (1999) is performed on the surface having the hard coating layer.

[0104] The material forming the hard coat layer in the present disclosure is not particularly limited as long as the HC breaking strength and HC breaking elongation of the laminated body of the present disclosure can be within the above-mentioned ranges.

[0105] The hard coat layer includes a cured product of a resin composition containing a polymerizable compound. The cured product of a resin composition containing a polymerizable compound can be obtained by polymerizing the polymerizable compound using a polymerization initiator according to need by a known method.

[0106] The polymerizable compound has at least one polymerizable functional group in the molecule. As the polymerizable compound, for example, at least one of a radical polymerizable compound and a cation polymerizable compound can be used.

[0107] A free radical polymerizable compound refers to a compound having a free radical polymerizable group. The free radical polymerizable group possessed by the free radical polymerizable compound is not particularly limited as long as it is a functional group capable of undergoing free radical polymerization reaction, and for example, a group containing a carbon-carbon unsaturated double bond can be cited, and specifically, vinyl, (meth) acryloyl, etc. can be cited. It should be noted that when the free radical polymerizable compound has two or more free radical polymerizable groups, these free radical polymerizable groups can be the same or different.

[0108] From the viewpoint of increasing the hardness of the hard coat layer, the number of radically polymerizable groups contained in one molecule of the radically polymerizable compound is preferably 2 or more, more preferably 3 or more.

[0109] In addition, in this specification, a (meth)acryloyl group represents an acryloyl group and a methacryloyl group respectively.

[0110] Cationic polymerizable compounds refer to compounds having cationic polymerizable groups. The cationic polymerizable groups possessed by cationic polymerizable compounds are not particularly limited as long as they are functional groups capable of undergoing cationic polymerization, and examples thereof include epoxy groups, oxetane groups, vinyl ether groups, etc. It should be noted that when a cationic polymerizable compound has two or more cationic polymerizable groups, these cationic polymerizable groups may be the same or different.

[0111] From the viewpoint of increasing the hardness of the hard coat layer, the number of cationically polymerizable groups contained in one molecule of the cationically polymerizable compound is preferably 2 or more, more preferably 3 or more.

[0112] The above-mentioned resin combination can contain a polymerization initiator as required. As the polymerization initiator, free radical polymerization initiator, cationic polymerization initiator, free radical and cationic polymerization initiator etc. can be appropriately selected and used. These polymerization initiators are decomposed by at least one of light irradiation and heating to produce free radicals or cations, thereby allowing free radical polymerization and cationic polymerization to proceed. It should be noted that in the hard coat layer, sometimes the polymerization initiator is completely decomposed and does not remain.

[0113] In the present disclosure, in order to improve the HC elongation at break, for example, by using a soft ethylene oxide-containing compound as a part of the hard coating material, such as a polymerizable compound, the hard coating layer can be given film-forming properties and adhesion, and the elongation at break of the hard coating layer can be improved. Examples of such compounds include poly(oxyalkylene) alkyl ether compounds containing a (meth)acryloyl group. Examples of poly(oxyalkylene) alkyl ether compounds containing a (meth)acryloyl group include LIGHT ESTER3EG-A, LIGHT ESTER4EG-A, LIGHT ESTER9EG-A (all from Kyoeisha Chemical), A-200, A-400 (all from Shin-Nakamura Chemical), MPE400A, and MPE550A (all from Osaka Organic Chemical Industry Co., Ltd.).

[0114] The thickness of the hard coating layer is not particularly limited as long as it is a thickness that allows the HC elongation at break of the laminated body disclosed in the present invention to fall within the above range. As a specific thickness, for example, it is preferably 1 μm to 35 μm, more preferably 2 μm to 25 μm, and particularly preferably 3 μm to 25 μm. By making the thickness of the hard coating layer fall within the above range, it is easy to adjust the HC elongation at break of the laminated body disclosed in the present invention to fall within the above range.

[0115] The hard coat layer may further contain additives as required. The additives may be appropriately selected according to the functions imparted to the hard coat layer, and are not particularly limited, and examples thereof include fillers, ultraviolet light absorbers, infrared light absorbers, antifouling agents, antiglare agents, antistatic agents, leveling agents, surfactants, lubricants, various sensitizers, flame retardants, tackifiers, polymerization inhibitors, antioxidants, light stabilizers, surface modifiers, and the like.

[0116] As a method for forming the hard coat layer, for example, there is a method of applying a curable resin composition for a hard coat layer containing the above-mentioned polymerizable compound and the like on the above-mentioned base layer and curing the composition.

[0117] The Martens hardness (HM) at the center of the cross section of the hard coating of the hard coating in the present disclosure is preferably 50MPa or more, and more preferably 100MPa or more. The "Martens hardness" in this specification refers to the hardness when the indenter is pressed into 500nm by the hardness measurement based on the nanoindentation method. In the above-mentioned determination of the Martens hardness based on the nanoindentation method, the "TI950 TriboIndenter" made by Bruker (Bruker) is used in an optical film cut into a size of 30mm×30mm. That is, under the following measurement conditions, the Berkovich indenter (triangular pyramid, such as TI-0039 manufactured by Bruker) is used as the above-mentioned indenter to press the cross section 500nm of the hard coating vertically. Here, in order to avoid the influence of the side edge of the impact absorbing layer or the hard coating, the Berkovich indenter is pressed into the portion of the hard coating with a distance of 500nm from the interface of the impact absorbing layer and the hard coating to the central side of the hard coating and a distance of 500nm or more from the two side ends of the hard coating to the central side of the hard coating. Then, after the residual stress is relaxed while being kept constant, it is unloaded and the maximum load after relaxation is measured. The maximum load Pmax and the depression area A with a depth of 500nm are used to calculate the Martens hardness by Pmax / A. The Martens hardness is the arithmetic mean of the values ​​obtained by measuring 10 places. It should be noted that when the measured value contains a measured value that deviates from the arithmetic mean by more than ±20%, the measured value is excluded and re-measured. Whether there is a measured value that deviates from the arithmetic mean by more than ±20% in the measured value is determined by setting the measured value to A and the arithmetic mean to B, based on whether the value (%) obtained by (AB) / B×100 is more than ±20%.

[0118] (Measurement conditions)

[0119] Control method: displacement control

[0120] Loading speed: 10nm / sec

[0121] Hold time: 5 seconds

[0122] Unloading speed: 10nm / sec

[0123] ·Measurement temperature: 23±5℃

[0124] ·Measurement humidity: 30%~70%

[0125] (2) Glass substrate

[0126] The display device member of the present disclosure is preferably used by arranging a glass substrate having a thickness of 100 μm or less on the surface of the impact absorbing layer of the laminate on the opposite side to the hard coat layer.

[0127] The glass constituting the glass substrate is not particularly limited, but chemically strengthened glass is preferred. Chemically strengthened glass is preferred in that it has excellent mechanical strength and can be thinned accordingly. Typically, chemically strengthened glass is glass whose mechanical properties are strengthened by chemical methods by partially exchanging ion species with potassium instead of sodium near the surface of the glass, and has a compressive stress layer on the surface.

[0128] Examples of the glass constituting the chemically strengthened glass substrate include aluminosilicate glass, soda-lime glass, borosilicate glass, lead glass, alkali barium glass, and aluminoborosilicate glass.

[0129] Commercially available products of chemically strengthened glass substrates include, for example, Gorilla Glass from Corning and Dragontrail from AGC. In addition, as a chemically strengthened glass substrate, for example, a chemically strengthened glass substrate described in Japanese Patent Application Laid-Open No. 2019-194143 may be used.

[0130] The thickness of the glass substrate is 100 μm or less, preferably 15 μm or more and 100 μm or less, more preferably 20 μm or more and 90 μm or less, and further preferably 25 μm or more and 80 μm or less. By reducing the thickness of the glass substrate to the above range, good flexibility can be obtained, and sufficient hardness can be obtained. In addition, the curling of the display device component can be suppressed. Furthermore, it is preferred in terms of lightweighting of the display device component.

[0131] (3) Other components

[0132] The display device member in the present disclosure may have other layers as necessary in addition to the above-mentioned layers. Examples of the other layers include a primer layer, a resin layer, and a decorative layer.

[0133] a) Primer

[0134] For example Figure 3 As shown, the display device member in the present disclosure may include a primer layer 6 between the glass substrate 5 and the impact absorbing layer 2. The primer layer can improve the adhesion between the glass substrate and the impact absorbing layer.

[0135] The material of the primer layer is not particularly limited as long as it can improve the adhesion between the glass substrate and the impact absorbing layer, and examples thereof include resins. Examples of the resins include (meth) acrylic resins, urethane resins, (meth) acrylic acid urethane copolymers, vinyl chloride-vinyl acetate copolymer resins, polyesters, butyral resins, chlorinated polypropylene, chlorinated polyethylene, epoxy resins, silicone resins, etc. These resins may be used alone or in combination of two or more.

[0136] The thickness of the primer layer may be any thickness that can improve the adhesion between the glass substrate and the impact absorbing layer, and may be, for example, 0.1 μm to 10 μm, and preferably 0.2 μm to 5 μm.

[0137] As a method for forming the primer layer, for example, a method of coating a primer composition on a glass substrate can be cited. As a coating method, for example, a general coating method such as a gravure coating method, a reverse gravure coating method, a gravure offset coating method, a spin coating method, a roll coating method, a reverse roll coating method, a blade coating method, a dip coating method, and a screen printing method can be cited. In addition, a transfer method can also be used as a method for forming the primer layer.

[0138] b) Resin layer

[0139] For example Figure 4 As shown, the display device component in the present disclosure may include a resin layer 7 on the surface side of the glass substrate 5 opposite to the impact absorbing layer 2. When an impact is applied to the display device component, not only the impact absorbing layer but also the resin layer absorbs the impact, which can suppress the breakage of the glass substrate and improve the impact resistance.

[0140] The resin contained in the resin layer is not particularly limited as long as it is a resin capable of absorbing impact, and examples thereof include urethane resins, epoxy resins, polyimides, polyamide-imides, acrylic resins, triacetyl cellulose (TAC), etc. These resins may be used alone or in combination of two or more.

[0141] The resin layer may further contain an additive as necessary. Examples of the additive include an ultraviolet absorber and the like.

[0142] The thickness of the resin layer may be any thickness capable of absorbing impact, and is, for example, preferably 5 μm to 60 μm, more preferably 10 μm to 50 μm, and further preferably 15 μm to 40 μm.

[0143] The resin layer may be formed by the same method as the above-mentioned method for forming the impact absorbing layer.

[0144] c) Decorative layer

[0145] The display device member in the present disclosure may include a decorative layer between the glass substrate and the resin layer, or on the surface of the glass substrate opposite to the resin layer.

[0146] The decorative layer includes a colorant and a binder resin. The binder resin contained in the decorative layer is not particularly limited, and a resin generally used in a decorative layer can be used. In addition, the colorant contained in the decorative layer is not particularly limited, and a known colorant generally used in a decorative layer can be used.

[0147] The decorative layer is usually disposed on a portion of the glass substrate. In addition, the decorative layer may also have a pattern shape.

[0148] The thickness of the decorative layer is not particularly limited, and may be, for example, 5 μm or more and 40 μm or less.

[0149] 3. Characteristics of display device components

[0150] The total light transmittance of the display device member disclosed in the present invention is preferably 80% or more, more preferably 85% or more, and further preferably 88% or more. By making the total light transmittance so high, a display device member having good transparency can be obtained.

[0151] Here, the total light transmittance of the display device member can be measured in accordance with JIS K7361-1, for example, by using a haze meter HM150 manufactured by Murakami Color Research Laboratory.

[0152] The haze of the display device member in the present disclosure is, for example, preferably 2.0% or less, more preferably 1.5% or less, and further preferably 1.0% or less.

[0153] By making the haze so low, a display device member having excellent transparency can be obtained.

[0154] Here, the haze of the display device member can be measured in accordance with JIS K-7136, for example, using a haze meter HM150 manufactured by Murakami Color Research Laboratory.

[0155] 4. Application of display device components

[0156] The display device component in the present disclosure can be used as a component arranged on the observer side of the display device rather than the display panel. The display device component in the present disclosure can be used, for example, for display device components of smartphones, tablet terminals, wearable terminals, personal computers, televisions, digital signage, public information displays (PIDs), car displays, etc. Among them, the display device component in the present disclosure can be preferably used for flexible displays such as foldable displays, rollable displays, and bendable displays, and can be suitable for foldable display components.

[0157] In the display device member of the present disclosure, the surface that becomes the outermost surface when the display device member is arranged on the surface of the display device is preferably the surface on the hard coat layer side.

[0158] The method of placing the display device member in the present disclosure on the surface of the display device is not particularly limited, and examples thereof include a method using an adhesive layer, etc. As the adhesive layer, a known adhesive layer used for bonding display device members can be used.

[0159] B. Display device

[0160] A display device in the present disclosure includes a display panel and the display device member disposed on the viewer side of the display panel.

[0161] Figure 5 is a schematic cross-sectional view showing an example of a display device in the present disclosure. Figure 5 As shown, the display device 30 includes a display panel 31, a touch panel component 32, and a display device component 1 disposed on the viewer side of the display panel 31 and the touch panel component 32. In the display device 30, the display device component 1 is used as a component disposed on the surface of the display device 30, and an adhesive layer 34 is disposed between the display device component 1 and the touch panel component 32. In addition, an adhesive layer 33 is also disposed between the display panel 31 and the touch panel component 32.

[0162] The display device member in the present disclosure may be the same as the display device member described above.

[0163] Examples of the display panel in the present disclosure include display panels used in display devices such as liquid crystal display devices, organic EL display devices, and LED display devices.

[0164] The display device in the present disclosure may include a touch panel component between the display panel and the display device component.

[0165] The display device in the present disclosure is preferably a flexible display. Among them, the display device in the present disclosure is preferably foldable. That is, the display device in the present disclosure is more preferably a foldable display. Since the display device in the present disclosure has the above-mentioned display device component, it has excellent bending resistance and is suitable as a flexible display and further a foldable display.

[0166] It should be noted that the present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are illustrative, and those having substantially the same configuration and having the same function and effect as the technical concept described in the scope of the claims of this feedback are all included in the technical scope of the present disclosure.

[0167] Example

[0168] Hereinafter, examples and comparative examples are shown to further illustrate the present disclosure.

[0169] [Example 1]

[0170] <Production of Shock Absorbing Layer (SA1)>

[0171] As a release film, a polyethylene terephthalate substrate with a thickness of 100 μm (product name "Cosmoshine (registered trademark) A4160", manufactured by Toyobo Co., Ltd.) was prepared. The following impact absorbing layer composition 1 was applied to the untreated surface of the polyethylene terephthalate substrate using a bar coater to form a coating film with a thickness of 80 μm after curing. An ultraviolet irradiation device (manufactured by Fusion UV Systems Japan, light source H bulb) was used to irradiate the film in air at a cumulative light intensity of 500 mJ / cm 2 The coating is cured by irradiating ultraviolet light to form an impact absorbing layer.

[0172] <Composition 1 for impact absorbing layer>

[0173] Urethane acrylate (product name "UV-3310B" manufactured by Mitsubishi Chemical Corporation): 20 parts by mass

[0174] Urethane acrylate (product name "UV-3000B" manufactured by Mitsubishi Chemical Corporation): 20 parts by mass

[0175] Ethoxylated pentaerythritol tetraacrylate (product name "ATM-35E" manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 20 parts by mass

[0176] Acryloylmorpholine (product name: "4-Acryloylmorpholine", manufactured by Tokyo Chemical Industry Co., Ltd.): 40 parts by mass

[0177] Polymerization initiator (product name "Omnirad 184" manufactured by IGM Resins BV): 5 parts by mass

[0178] <Preparation of Hard Coat (HC1)>

[0179] The surface of the impact absorbing layer formed above on the opposite side of the release film was coated with the following hard coating resin composition 1 using a rod coater to form a coating film. The coating film was then heated at 70°C for 1 minute to evaporate the solvent in the coating film. An ultraviolet irradiation device (Fusion UV Systems Japan, light source H bulb) was used in an environment with an oxygen concentration of less than 100 ppm, with a cumulative light intensity of 200 mJ / cm 2 The coating was cured by irradiating ultraviolet light in a manner to form a hard coating layer HC1 with a thickness of 6 μm. Thus, a laminate with a release film having a release film, an impact absorbing layer and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and an impact absorbing layer was obtained.

[0180] <Hard Coat Composition 1>

[0181] ※ Values ​​based on solid content excluding solvents being 100%.

[0182] Urethane acrylate (product name "KUA-10H", manufactured by KSM Corporation): 100 parts by mass

[0183] Polymerization initiator (1-hydroxycyclohexyl phenyl ketone, product name "Omnirad 184", manufactured by IGM Resins BV): 4 parts by mass

[0184] Leveling agent (product name "BYK-UV3535", manufactured by BYK Chemical Japan Co., Ltd.): 0.5 parts by mass (based on 100% solid content)

[0185] Solvent "methyl isobutyl ketone": 313.5 parts by mass

[0186] [Example 2]

[0187] <Production of Shock Absorbing Layer (SA1)>

[0188] A shock absorbing layer was formed on the release film in the same manner as in Example 1 except that the coating film was formed so as to have a thickness of 100 μm after curing.

[0189] <Preparation of Hard Coat (HC2)>

[0190] The hard coating layer HC2 was formed in the same manner as in Example 1 except that the following hard coating resin composition 2 was applied to the surface of the impact absorbing layer formed above on the opposite side to the release film by a bar coater so as to have a film thickness of 20 μm. Thus, a laminate with a release film having a release film, an impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and an impact absorbing layer was obtained.

[0191] <Hard Coat Composition 2>

[0192] Ethoxylated pentaerythritol tetraacrylate (product name "ATM-35E", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 95 parts by mass

[0193] Polyethylene glycol diacrylate (product name "A-200", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 5 parts by mass

[0194] Polymerization initiator (product name "Omnirad 184", manufactured by IGM Resins BV): 4 parts by mass

[0195] Leveling agent (product name "BYK-UV3535", manufactured by BYK Chemical Japan Co., Ltd.): 0.5 parts by mass (based on 100% solid content)

[0196] Solvent "methyl isobutyl ketone": 313.5 parts by mass

[0197] [Example 3]

[0198] <Production of Shock Absorbing Layer (SA1)>

[0199] By the same method as in Example 2, a shock absorbing layer was formed on the release film.

[0200] <Preparation of Hard Coat (HC2)>

[0201] A hard coating layer HC2 was formed on the surface of the impact absorbing layer opposite to the release film in the same manner as in Example 2 except that the film thickness was 15 μm. Thus, a laminate with a release film having a release film, a impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and a impact absorbing layer was obtained.

[0202] [Example 4]

[0203] <Production of Shock Absorbing Layer (SA1)>

[0204] By the same method as in Example 1, a shock absorbing layer was formed on the release film.

[0205] <Preparation of Hard Coat (HC2)>

[0206] A hard coating layer HC2 was formed on the surface of the impact absorbing layer opposite to the release film in the same manner as in Example 2 except that the film thickness was 12 μm. Thus, a laminate with a release film having a release film, a impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and a impact absorbing layer was obtained.

[0207] [Example 5]

[0208] <Production of Shock Absorbing Layer (SA1)>

[0209] By the same method as in Example 1, a shock absorbing layer was formed on the release film.

[0210] <Preparation of Hard Coat (HC2)>

[0211] A hard coating layer HC2 was formed on the surface of the impact absorbing layer opposite to the release film in the same manner as in Example 2 except that the film thickness was 6 μm. Thus, a laminate with a release film having a release film, a impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and a impact absorbing layer was obtained.

[0212] [Example 6]

[0213] <Production of Shock Absorbing Layer (SA2)>

[0214] As a release film, a polyethylene terephthalate substrate with a thickness of 100 μm (product name "Cosmoshine (registered trademark) A4160", manufactured by Toyobo Co., Ltd.) was prepared. The following impact absorbing layer composition 2 was applied to the untreated surface of the polyethylene terephthalate substrate using a bar coater to form a coating film with a thickness of 80 μm after curing. An ultraviolet irradiation device (manufactured by Fusion UV Systems Japan, light source H bulb) was used to irradiate the film in air at a cumulative light intensity of 500 mJ / cm 2 The coating film is cured by irradiating ultraviolet rays in a manner to produce an impact absorbing layer.

[0215] <Shock-absorbing layer composition 2>

[0216] Urethane acrylate (product name "UV-3310B", manufactured by Mitsubishi Chemical Corporation): 30 parts by mass

[0217] Urethane acrylate (product name "UV-6630B", manufactured by Mitsubishi Chemical Corporation): 10 parts by mass

[0218] A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (product name "PET-30", manufactured by Nippon Kayaku Co., Ltd.): 20 parts by mass

[0219] Acryloylmorpholine (product name: "4-Acryloylmorpholine", manufactured by Tokyo Chemical Industry Co., Ltd.): 20 parts by mass

[0220] N-Hydroxyethyl acrylamide (product name "N-(2-Hydroxyehtyl)acrylamide", manufactured by KJ Chemicals Co., Ltd.): 20 parts by mass

[0221] Polymerization initiator (product name "Omnirad 184", manufactured by IGM Resins BV): 5 parts by mass

[0222] <Preparation of Hard Coat (HC2)>

[0223] A hard coating layer HC2 was formed on the surface of the impact absorbing layer on the opposite side of the release film by the same method as in Example 5. Thus, a laminate with a release film having a release film, an impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and an impact absorbing layer was obtained.

[0224] [Example 7]

[0225] <Production of Shock Absorbing Layer (SA1)>

[0226] By the same method as in Example 1, a shock absorbing layer was formed on the release film.

[0227] <Preparation of Hard Coat (HC2)>

[0228] A hard coating layer HC2 was formed on the surface of the impact absorbing layer on the opposite side of the release film in the same manner as in Example 2 except that the film thickness was 4 μm. Thus, a laminate with a release film having a release film, a impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and a impact absorbing layer was obtained.

[0229] [Example 8]

[0230] <Production of Shock Absorbing Layer (SA3)>

[0231] As a release film, a polyethylene terephthalate substrate with a thickness of 100 μm (product name "Cosmoshine (registered trademark) A4160", manufactured by Toyobo Co., Ltd.) was prepared. The following impact absorbing layer composition 3 was applied to the untreated surface of the polyethylene terephthalate substrate using a bar coater to form a coating film with a thickness of 80 μm after curing. An ultraviolet irradiation device (manufactured by Fusion UV Systems Japan, light source H bulb) was used to irradiate the film in air at a cumulative light intensity of 500 mJ / cm 2 The coating is cured by irradiating ultraviolet light to form an impact absorbing layer.

[0232] <Shock-absorbing layer composition 3>

[0233] Urethane acrylate (product name "UV-3310B", manufactured by Mitsubishi Chemical Corporation): 10 parts by mass

[0234] Urethane acrylate (product name "UV-3000B", manufactured by Mitsubishi Chemical Corporation): 30 parts by mass

[0235] A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (product name "PET-30", manufactured by Nippon Kayaku Co., Ltd.): 20 parts by mass

[0236] Acryloylmorpholine (product name: "4-Acryloylmorpholine", manufactured by Tokyo Chemical Industry Co., Ltd.): 30 parts by mass

[0237] N-Hydroxyethyl acrylamide (product name "N-(2-Hydroxyehtyl)acrylamide", manufactured by KJ Chemicals Co., Ltd.): 10 parts by mass

[0238] Polymerization initiator (product name "Omnirad 184" manufactured by IGM Resins BV): 5 parts by mass

[0239] <Preparation of Hard Coat (HC2)>

[0240] A hard coating layer HC2 was formed on the surface of the impact absorbing layer on the opposite side of the release film by the same method as in Example 5. Thus, a laminate with a release film having a release film, an impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and an impact absorbing layer was obtained.

[0241] [Example 9]

[0242] <Production of Shock Absorbing Layer (SA3)>

[0243] A shock absorbing layer was produced in the same manner as in Example 8 except that the coating film was formed to have a thickness of 100 μm after curing.

[0244] <Preparation of Hard Coat (HC1)>

[0245] A hard coating layer HC1 was formed on the surface of the impact absorbing layer on the opposite side of the release film by the same method as in Example 1. Thus, a laminate with a release film having a release film, an impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and an impact absorbing layer was obtained.

[0246] [Example 10]

[0247] <Production of Shock Absorbing Layer (SA1)>

[0248] A shock absorbing layer was produced in the same manner as in Example 1 except that the coating film was formed to have a thickness of 50 μm after curing.

[0249] <Preparation of Hard Coat (HC3)>

[0250] The hard coating layer HC3 was formed by the same method as in Example 1 except that the following hard coating resin composition 3 was applied to the surface of the impact absorbing layer on the opposite side of the release film by a bar coater. Thus, a laminate with a release film having a release film, an impact absorbing layer and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and an impact absorbing layer was obtained.

[0251] <Hard Coat Composition 3>

[0252] Ethoxylated pentaerythritol tetraacrylate (product name "ATM-35E", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 80 parts by mass

[0253] Polyethylene glycol diacrylate (product name "A-200", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 20 parts by mass

[0254] Polymerization initiator (product name "Omnirad 184", manufactured by IGM Resins BV): 4 parts by mass

[0255] Leveling agent (product name "BYK-UV3535", manufactured by BYK Chemical Japan Co., Ltd.): 0.5 parts by mass (based on 100% solid content)

[0256] Solvent "methyl isobutyl ketone": 313.5 parts by mass

[0257] [Example 11]

[0258] <Production of Shock Absorbing Layer (SA1)>

[0259] A shock absorbing layer was produced in the same manner as in Example 1 except that the coating film was formed to have a thickness of 40 μm after curing.

[0260] <Preparation of Hard Coat (HC3)>

[0261] A hard coat layer HC3 was formed on the surface of the impact absorbing layer on the opposite side of the release film by the same method as in Example 10. Thus, a laminate with a release film having a release film, an impact absorbing layer, and a hard coat layer in this order was obtained. By peeling off the release film, a laminate having a hard coat layer and an impact absorbing layer was obtained.

[0262] [Example 12]

[0263] <Production of Shock Absorbing Layer (SA2)>

[0264] A shock absorbing layer was produced in the same manner as in Example 6 except that the coating film was formed to have a thickness of 50 μm after curing.

[0265] <Preparation of Hard Coat (HC3)>

[0266] A hard coat layer HC3 was formed on the surface of the impact absorbing layer on the opposite side of the release film by the same method as in Example 10. Thus, a laminate with a release film having a release film, an impact absorbing layer, and a hard coat layer in this order was obtained. By peeling off the release film, a laminate having a hard coat layer and an impact absorbing layer was obtained.

[0267] [Comparative Example 1]

[0268] <Production of Shock Absorbing Layer (SA3)>

[0269] A shock absorbing layer was produced in the same manner as in Example 8 except that the coating film was formed to have a thickness of 120 μm after curing.

[0270] <Preparation of Hard Coat (HC1)>

[0271] A hard coating layer HC1 was formed on the surface of the impact absorbing layer on the opposite side of the release film in the same manner as in Example 1 except that the film thickness was 12 μm. Thus, a laminate with a release film having a release film, an impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and an impact absorbing layer was obtained.

[0272] [Comparative Example 2]

[0273] <Production of shock absorbing layer SA3)>

[0274] The impact absorbing layer was prepared in the same manner as in Example 8.

[0275] <Preparation of Hard Coat (HC1)>

[0276] A hard coating layer HC1 was formed on the surface of the impact absorbing layer on the opposite side of the release film by the same method as in Example 1. Thus, a laminate with a release film having a release film, an impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and an impact absorbing layer was obtained.

[0277] [Comparative Example 3]

[0278] <Production of Shock Absorbing Layer (SA3)>

[0279] A shock absorbing layer was produced in the same manner as in Example 8 except that the coating film was formed to have a thickness of 50 μm after curing.

[0280] <Preparation of Hard Coat (HC4)>

[0281] The hard coating layer HC4 was formed by the same method as in Example 1 except that the following hard coating resin composition 4 was applied to the surface of the impact absorbing layer on the opposite side of the release film by a bar coater. Thus, a laminate with a release film having a release film, an impact absorbing layer and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and an impact absorbing layer was obtained.

[0282] <Hard Coat Composition 4>

[0283] Ethoxylated pentaerythritol tetraacrylate (product name "ATM-35E", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 70 parts by mass

[0284] Ethoxylated dipentaerythritol polyacrylate (product name "A-DPH-12E", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 30 parts by mass

[0285] Polymerization initiator (product name "Omnirad 184", manufactured by IGM Resins BV): 4 parts by mass

[0286] Leveling agent (product name "BYK-UV3535", manufactured by BYK Chemical Japan Co., Ltd.): 0.5 parts by mass (based on 100% solid content)

[0287] Solvent "methyl isobutyl ketone": 313.5 parts by mass

[0288] [Comparative Example 4]

[0289] <Production of Shock Absorbing Layer (SA1)>

[0290] The impact absorbing layer was prepared in the same manner as in Example 10.

[0291] <Preparation of Hard Coat (HC4)>

[0292] A hard coating layer HC4 was formed on the surface of the impact absorbing layer on the opposite side of the release film by the same method as in Comparative Example 3. Thus, a laminate with a release film having a release film, an impact absorbing layer, and a hard coating layer in this order was obtained. By peeling off the release film, a laminate having a hard coating layer and an impact absorbing layer was obtained.

[0293] [Measurement of Young's modulus of laminate and impact absorbing layer]

[0294] The Young's modulus of the laminate and the impact absorbing layer were measured by the method described in "A. Display device component 1. Properties of laminate (3) Young's modulus of laminate" and "A. Display device component 2. Configuration of display device component (1) Laminate a) Impact absorbing layer". The results are shown in Table 1.

[0295] [Determination of elongation at break and breaking strength of hard coating]

[0296] The elongation at break and the strength at break of the hard coat layer were measured by the method described in “A. Display device member 1. Properties of laminate (1) HC elongation at break”. The results are shown in Table 1.

[0297] [evaluate]

[0298] (1) Impact resistance test (pen drop test)

[0299] The laminated bodies of Examples and Comparative Examples were subjected to an impact resistance test.

[0300] An optical adhesive (OCA) film is attached to the surface on the impact-absorbing layer side of the laminate, the diaphragm is peeled off, and the OCA surface is bonded to a glass substrate (glass plate (trade name "G-leaf", manufactured by Nippon Electric Glass Co., Ltd., thickness 30 μm, minimum bending radius 3 mm). Thus, a display device component having a hard coating layer, an impact-absorbing layer, an optical adhesive layer and a glass substrate in sequence is manufactured. The display device component is arranged on a stone table. At this time, the glass substrate of the display device component is arranged in a manner opposite to the stone table. Next, a ballpoint pen with a pen tip of φ0.7 mm and a weight of 5 g is dropped from a height of 10 cm. The condition of the dropped part is observed with a 10x magnifying glass to confirm the degree of damage and to make a judgment according to the following evaluation criteria.

[0301] Evaluation benchmark

[0302] A: No damage

[0303] B: There are dents

[0304] C: Cracked or broken

[0305] (2) Bending resistance test (folding resistance test)

[0306] The laminates of the examples and comparative examples were subjected to a continuous folding test to evaluate their folding resistance. Specifically, first, a measurement sample of 20 mm × 100 mm was cut out from the laminate. Then, Figure 6 As shown in (a), the two opposite short sides 50C and 50D of the laminate (measurement sample) 50 are fixed by the fixing part 51 of the folding durability tester (for example, product name "U-shaped stretch tester DLDMLH-FS", manufactured by Yuasa System Instrument Co., Ltd., in accordance with IEC62715-6-1) arranged in parallel, and the laminate (measurement sample) 50 is installed in a manner that the laminate (measurement sample) 50 is folded into a U shape in the long side direction. Then, as Figure 6As shown in (a) to (c), a continuous folding test of 180° folding was performed 200,000 times under the following conditions, with the minimum interval d between the two opposite short sides 50C and 50D of the laminate (measurement sample) 50 being 7 mm and the hard coating side of the laminate (measurement sample) 50 being the outside, to investigate whether the bending portion 50E of the laminate (measurement sample) 50 is deformed, cracked or broken. The continuous folding test was performed at room temperature (23°C) and a relative humidity of 50%. In addition, a continuous folding test of 180° folding was performed 200,000 times in a manner where the minimum interval d between the two short sides 50C and 50D was 3 mm and the hard coating side of the laminate (measurement sample) 50 was the inside. Furthermore, a continuous folding test of 180° folding was performed 200,000 times in a manner where the minimum interval d between the two short sides 50C and 50D was 6 mm and the hard coating side of the laminate (measurement sample) 50 was the inside. The evaluation criteria are as follows. The results are shown in Table 2.

[0307] Evaluation benchmark

[0308] A: In the continuous folding test, no cracks or wrinkles were generated at the bent portion.

[0309] B: In the continuous folding test, the bent portion was not broken, but two or less wrinkles were generated.

[0310] C: In the continuous folding test, cracks or wrinkles were clearly observed at the bent portion.

[0311] (3) Abrasion resistance test (steel wool test)

[0312] The scratch resistance of the laminated bodies for display devices obtained in Examples and Comparative Examples was evaluated by the following test method.

[0313] Using the Gakushin type friction fastness tester AB-301 manufactured by TESTER SANGYO CO., LTD., a 5cm×10cm laminate was fixed on a glass plate using Cellotape (registered trademark) so that it had no bends or wrinkles. Next, #0000 steel wool (Bonstar#0000 manufactured by Japan Steel Wool Co., Ltd.) was used to fix the steel wool to a 1cm×1cm fixture, and the surface on the hard coating side of the laminate was rubbed under the conditions of a load of 1.5kg / cm2, a moving speed of 100mm / second, and a moving distance of 50mm. The number of reciprocating times until the hard coating peeled off was determined, and the evaluation was performed according to the following evaluation criteria.

[0314] Evaluation benchmark

[0315] A: More than 1000 times

[0316] B: More than 100 times and less than 1000 times

[0317] C: Less than 100 times

[0318] As a comprehensive evaluation of the impact resistance test, bending resistance test and abrasion resistance test, the case where all three tests were judged as A was evaluated as "A", the case where one or more B was evaluated was evaluated as "B", and the case where one or more C was evaluated was evaluated as "C".

[0319] [Table 1]

[0320]

[0321] [Table 2]

[0322]

[0323] Figure 7 The above results are plotted with the horizontal axis being the HC layer elongation at break and the vertical axis being the HC layer breaking strength. Figure 7 As shown, it was confirmed that Examples 1 to 12 were superior to Comparative Examples 1 to 4 in comprehensive evaluation of the impact resistance test, the bending resistance test, and the abrasion resistance test.

[0324] That is, the present disclosure can provide the following inventions. [1]

[0326] A display device component, comprising a laminated body in which an impact absorbing layer and a hard coating layer are laminated, wherein:

[0327] When measuring the tensile stress of the laminate, the stress at which the hard coating layer breaks is defined as the hard coating layer breaking strength, and the elongation at which the hard coating layer breaks is defined as the hard coating layer breaking elongation.

[0328] The hard coating layer has a breaking strength of 7 MPa or more, and a breaking elongation of the hard coating layer of 4% or more and 36% or less. [2]

[0330] The display device member according to [1], wherein the hard coat layer has an elongation at break of less than 30%. [3]

[0332] The display device member according to [1] or [2], wherein a glass substrate having a thickness of 100 μm or less is disposed on a surface of the impact absorbing layer opposite to the hard coat layer. [4]

[0334] A display device comprising: a display panel; and

[0335] The display device component according to any one of [1] to [3], arranged on the viewer side of the display panel. [5]

[0337] The display device as described in [4] is foldable.

[0338] Description of Reference Numerals

[0339] 1…Parts for display devices

[0340] 2…Shock absorbing layer

[0341] 3…Hard coating

[0342] 4…Laminated body

[0343] 5…Glass substrate

[0344] 6…Base coating

[0345] 7…Resin layer

[0346] 30…Display device

[0347] 31…Display Panel

[0348] 32…Touch panel components

[0349] 33, 34… Adhesive layer

Claims

1. A display device component, comprising a laminated body in which an impact absorbing layer and a hard coating layer are laminated, wherein: When measuring the tensile stress of the laminate, the stress at which the hard coating layer breaks is defined as the hard coating layer breaking strength, and the elongation at which the hard coating layer breaks is defined as the hard coating layer breaking elongation. The hard coating layer has a breaking strength of 7 MPa or more, and a breaking elongation of the hard coating layer of 4% or more and 36% or less.

2. The display device component according to claim 1, wherein: The elongation at break of the hard coating is less than 30%.

3. The display device component according to claim 1, wherein: A glass substrate having a thickness of 100 μm or less is disposed on a surface of the impact absorbing layer opposite to the hard coating layer.

4. A display device comprising: a display panel; and The display device member according to any one of claims 1 to 3, arranged on the viewer side of the display panel. The display device as claimed in claim 4 , which is foldable.

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