Laminates, electronic devices, cover glass, and resin compositions

Abstract

The present invention provides a laminate with excellent impact resistance, an electronic device and cover glass using the laminate, and a resin composition used to form the resin layer of the laminate. [Solution] The solution comprises a thin glass plate with a thickness of 200 μm or less, and a resin layer with a thickness of 5 μm or more disposed on at least one side of the thin glass plate, wherein the rupture energy of the resin layer is 1 mJ / mm². 3 A laminate having the above characteristics and a storage modulus of elasticity of 2500 MPa or less at 25°C, or a laminate having a thin glass plate with a thickness of 200 μm or less and a resin layer with a thickness of 5 μm or more disposed on at least one side of the thin glass plate, wherein the Young's modulus of the resin layer is 50 MPa or more and 1500 MPa or less.

Description

[Technical Field]

[0001] The present invention relates to a laminate with excellent impact resistance. The present invention also relates to an electronic device and cover glass using the laminate, and a resin composition used to form the resin layer of the laminate. [Background technology]

[0002] In recent years, development has been progressing to make the display screens of electronic devices such as smartphones, e-books, and tablet PCs foldable. The use of a flexible thin sheet of glass on the outermost surface of such foldable display screens is being considered.

[0003] Because thin glass sheets are easily broken by impact, there is consideration to placing a protective resin layer on one side of the thin glass sheet. For example, Patent Document 1 describes a protective substrate for a display device comprising glass and a resin layer on one side of the glass, wherein the thickness of the glass is 20 μm to 200 μm and the specific gravity of the resin layer is 0.9 g / cm³. 3 ~1.5g / cm 3 The protective substrate for a display device is described, wherein the resin layer has a flexural modulus of 1000 MPa to 8000 MPa at 25°C. Furthermore, Patent Document 2 describes a protective substrate for a display device having a thin glass with a thickness of 120 μm or less, and an impact-absorbing layer with a thickness of 5 μm or more disposed on one side of the thin glass, wherein the impact-absorbing layer has a flexural modulus of 10 at 25°C. 1 ~10 15 An optical laminate having a maximum value of tanδ in the Hz range is described. Patent document 3 describes a cover member having a structure in which a glass plate with a thickness of 500 μm or less and a resin film are laminated with an adhesive layer in between. Patent document 4 describes a substrate for a display element comprising inorganic glass and resin layers arranged on both sides of the inorganic glass. However, with regard to resin compositions for forming resin layers to protect thin glass sheets, conventional methods have not adequately considered the composition from the perspective of improving impact resistance, or materials with insufficient impact resistance have been used. Therefore, there has been a need to further improve impact resistance. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2013-37207 [Patent Document 2] International Publication No. 2018 / 190208 [Patent Document 3] International Publication No. 2020 / 153259 [Patent Document 4] Japanese Patent Publication No. 2008-107510 [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to provide a laminate with excellent impact resistance. Furthermore, the present invention aims to provide electronic equipment and cover glass using the laminate, as well as a resin composition used to form the resin layer of the laminate. [Means for solving the problem]

[0006] Disclosure 1 comprises a thin glass sheet with a thickness of 200 μm or less, and a resin layer with a thickness of 5 μm or more disposed on at least one side of the thin glass sheet, wherein the rupture energy of the resin layer is 1 mJ / mm². 3 The above is true, and the storage modulus at 25°C is 2500 MPa or less, and this is the laminate (first laminate). Disclosure 2 is a laminate of Disclosure 1, wherein the Young's modulus of the resin layer is 50 MPa or more and 1500 MPa or less. Disclosure 3 is a laminate of Disclosure 1 or 2, wherein the storage modulus of the resin layer at 25°C is 2000 MPa or less. The present disclosure 4 is the laminate of the present disclosure 1, 2 or 3, wherein the glass transition temperature of the resin layer is 100° C. or lower. The present disclosure 5 is the laminate of the present disclosure 1, 2, 3 or 4, wherein the resin layer contains a polymer of a cation-curable resin. The present disclosure 6 is the laminate of the present disclosure 5, wherein the cation-curable resin contains an epoxy group-containing compound and an oxetanyl group-containing compound. The present disclosure 7 is the laminate of the present disclosure 6, wherein the epoxy group-containing compound contains a hydrogenated bisphenol type epoxy resin. The present disclosure 8 is the laminate of the present disclosure 7, wherein the hydrogenated bisphenol type epoxy resin contains a hydrogenated bisphenol A skeleton. The present disclosure 9 is the laminate of the present disclosure 7 or 8, wherein the epoxy equivalent of the hydrogenated bisphenol type epoxy resin is 100 or more and 2000 or less. The present disclosure 10 is the laminate of the present disclosure 6, 7, 8 or 9, wherein the epoxy group-containing compound contains an epoxy resin having a polyether skeleton. The present disclosure 11 is the laminate of the present disclosure 10, wherein the epoxy resin having a polyether skeleton is liquid at 23° C. The present disclosure 12 is the laminate of the present disclosure 6, 7, 8, 9, 10 or 11, wherein the oxetanyl group-containing compound is monofunctional. The present disclosure 13 is the laminate of the present disclosure 5, 6, 7, 8, 9, 10, 11 or 12, wherein the cation-curable resin contains a hydrogenated bisphenol type epoxy resin, an epoxy resin having a polyether skeleton, and an oxetanyl group-containing compound. The present disclosure 14 is the laminate of the present disclosure 13, wherein the content of the hydrogenated bisphenol type epoxy resin in the resin layer is 20% by weight or more and 60% by weight or less, the content of the epoxy resin having a polyether skeleton is 10% by weight or more and 20% by weight or less, and the content of the oxetanyl group-containing compound is 20% by weight or more and 60% by weight or less. The present disclosure 15 has a first resin layer with a thickness of 5 μm or more disposed on one side of the thin plate glass, and a second resin layer with a thickness of 5 μm or more disposed on the side of the thin plate glass opposite to the first resin layer side. Both the first resin layer and the second resin layer have a fracture energy of 1 mJ / mm 3 or more, and a storage elastic modulus at 25°C of 2500 MPa or less, which is the laminate of the present disclosure 1. The present disclosure 16 is the laminate of the present disclosure 15, in which both the first resin layer and the second resin layer have a Young's modulus of 50 MPa or more and 1500 MPa or less. The present disclosure 17 is the laminate of the present disclosure 15 or 16, in which at least one of the first resin layer and the second resin layer has a thickness of 25 μm or less. The present disclosure 18 is the laminate of the present disclosure 15, 16 or 17, in which at least one of the first resin layer and the second resin layer has a glass transition temperature of 100°C or less. The present disclosure 19 is the laminate of the present disclosure 15, 16, 17 or 18, in which at least one of the first resin layer and the second resin layer contains a polymer of a cation-curable resin.

[0007] The present disclosure 20 is a laminate (second laminate) having a thin plate glass with a thickness of 200 μm or less and a resin layer with a thickness of 5 μm or more disposed on at least one side of the thin plate glass, and the Young's modulus of the resin layer is 50 MPa or more and 1500 MPa or less. The present disclosure 21 is the laminate of the present disclosure 20, in which the fracture energy of the resin layer is 1 mJ / mm 3 or more. The present disclosure 22 is the laminate of the present disclosure 20 or 21, in which the storage elastic modulus of the resin layer at 25°C is 2500 MPa or less. The present disclosure 23 is the laminate of the present disclosure 20, 21 or 22, in which the glass transition temperature of the resin layer is 100°C or less. The present disclosure 24 is the laminate of the present disclosure 20, 21, 22 or 23, in which the resin layer contains a polymer of a cation-curable resin. <00Disclosure 25 is a laminate of Disclosure 24 in which the cationic curable resin comprises an epoxy group-containing compound and an oxetanyl group-containing compound. Disclosure 26 is a laminate of Disclosure 25 in which the epoxy group-containing compound comprises a hydrogenated bisphenol type epoxy resin. Disclosure 27 is a laminate of Disclosure 26 in which the hydrogenated bisphenol type epoxy resin contains a hydrogenated bisphenol A skeleton. Disclosure 28 is a laminate of Disclosure 26 or 27, wherein the epoxy equivalent of the hydrogenated bisphenol type epoxy resin is 100 or more and 2000 or less. Disclosure 29 is a laminate of Disclosure 25, 26, 27, or 28, wherein the epoxy group-containing compound comprises an epoxy resin having a polyether skeleton. Disclosure 30 is a laminate of Disclosure 29 in which the epoxy resin having the polyether skeleton is liquid at 23°C. Disclosure 31 is a laminate of Disclosures 25, 26, 27, 28, 29, or 30, wherein the oxetanyl group-containing compound is monofunctional. Disclosure 32 is a laminate of Disclosure 24, 25, 26, 27, 28, 29, 30 or 31, wherein the cationic curable resin comprises a hydrogenated bisphenol type epoxy resin, an epoxy resin having a polyether skeleton, and an oxetanyl group-containing compound. Disclosure 33 is a laminate of Disclosure 32, wherein the content of hydrogenated bisphenol type epoxy resin in the resin layer is 20% by weight or more and 60% by weight or less, the content of epoxy resin having a polyether skeleton is 10% by weight or more and 20% by weight or less, and the content of oxetanyl group-containing compound is 20% by weight or more and 60% by weight or less.

[0008] Disclosure 34 is a laminate of Disclosure 20, comprising a first resin layer with a thickness of 5 μm or more disposed on one side of the thin glass sheet, and a second resin layer with a thickness of 5 μm or more disposed on the side of the thin glass sheet opposite to the first resin layer, wherein both the first resin layer and the second resin layer have a Young's modulus of 50 MPa or more and 1500 MPa or less. Disclosure 35 is a laminate of Disclosure 34, wherein at least one of the first resin layer and the second resin layer has a storage modulus of 3000 MPa or less at 25°C. Disclosure 36 is a laminate of Disclosure 34 or 35, wherein at least one of the first resin layer and the second resin layer has a thickness of 25 μm or less. Disclosure 37 is a laminate of Disclosure 34, 35, or 36, wherein at least one of the first resin layer and the second resin layer has a glass transition temperature of 100°C or less. Disclosure 38 is a laminate of Disclosure 34, 35, 36, or 37, wherein at least one of the first resin layer and the second resin layer comprises a polymer of a cationic curable resin. Disclosure 39 is a laminate of Disclosure 38 in which the cationic curable resin comprises an epoxy group-containing compound and an oxetanyl group-containing compound. Disclosure 40 is a laminate of Disclosure 39 in which the epoxy group-containing compound comprises a hydrogenated bisphenol type epoxy resin. Disclosure 41 is a laminate of Disclosure 40 in which the hydrogenated bisphenol type epoxy resin contains a hydrogenated bisphenol A skeleton. Disclosure 42 is a laminate of Disclosure 40 or 41, wherein the epoxy equivalent of the hydrogenated bisphenol type epoxy resin is 100 or more and 2000 or less. Disclosure 43 is a laminate of Disclosure 39, 40, 41, or 42, wherein the epoxy group-containing compound comprises an epoxy resin having a polyether skeleton. Disclosure 44 is a laminate of Disclosure 43 in which the epoxy resin having the polyether skeleton is liquid at 23°C. Disclosure 45 is a laminate of Disclosures 39, 40, 41, 42, 43, or 44, wherein the oxetanyl group-containing compound is monofunctional. Disclosure 46 is a laminate of Disclosure 38, 39, 40, 41, 42, 43, 44 or 45, wherein the cationic curable resin comprises a hydrogenated bisphenol type epoxy resin, an epoxy resin having a polyether skeleton, and an oxetanyl group-containing compound. Disclosure 47 is a laminate of Disclosure 46, wherein the resin layer containing the polymer of the cationic curable resin contains 20% by weight or more and 60% by weight or less of hydrogenated bisphenol type epoxy resin, contains 10% by weight or more and 20% by weight or less of the epoxy resin having a polyether skeleton, and contains 20% by weight or more and 60% by weight or less of the oxetanyl group-containing compound.

[0009] Disclosure 48 is an electronic device comprising a laminate of any of Disclosures 1 to 47. Disclosure 49 is a cover glass comprising a laminate of any of Disclosures 1 to 47. Disclosure 50 is a resin composition used to form a resin layer of any of the laminates described in Disclosures 1 to 47. Disclosure 51 is a resin composition comprising a hydrogenated bisphenol type epoxy resin, an epoxy resin having a polyether skeleton, and an oxetanyl group-containing compound. Disclosure 52 is a resin composition of Disclosure 50 or 51 used for coating thin glass sheets with a thickness of 200 μm or less. Disclosure 53 is a resin composition of Disclosure 51 or 52 in which the hydrogenated bisphenol type epoxy resin contains a hydrogenated bisphenol A skeleton. Disclosure 54 is a resin composition of Disclosure 51, 52, or 53, wherein the epoxy equivalent of the hydrogenated bisphenol type epoxy resin is 100 or more and 2000 or less. Disclosure 55 is a resin composition of Disclosure 51, 52, 53, or 54, wherein the epoxy resin having the polyether skeleton is liquid at 23°C. Disclosure 56 is a resin composition of Disclosure 51, 52, 53, 54, or 55 in which the oxetanyl group-containing compound is monofunctional. Disclosure 57 is a resin composition according to Disclosures 51, 52, 53, 54, 55, or 56, wherein the content of the hydrogenated bisphenol type epoxy resin is 20% by weight or more and 60% by weight or less, the content of the epoxy resin having the polyether skeleton is 10% by weight or more and 20% by weight or less, and the content of the oxetanyl group-containing compound is 20% by weight or more and 60% by weight or less. The present invention will be described in detail below.

[0010] The inventors investigated a resin layer placed on at least one side of a thin glass sheet and, focusing on the correlation between the fracture energy, storage modulus, and impact resistance of the resin layer, set the fracture energy to 1 mJ / mm². 3 Furthermore, we found that sufficient impact resistance can be obtained by setting the storage modulus at 25°C to 2500 MPa or less. Furthermore, the inventors investigated a resin layer placed on at least one side of a thin glass sheet and, focusing on the correlation between the Young's modulus of the resin layer and its impact resistance, found that sufficient impact resistance can be obtained by setting the Young's modulus to 50 MPa or more and 1500 MPa or less. Furthermore, the inventors investigated how to improve the impact resistance of thin glass sheets placed on the display surfaces of electronic devices by laminating a resin layer on their surface. As a result, they found that by providing resin layers on both sides of the thin glass sheet, glass shattering can be effectively prevented, and that the impact resistance can be enhanced by adjusting the fracture energy of the first and second resin layers to a specific range by adjusting the combination of fracture energy and storage modulus or Young's modulus. The inventors have found a resin composition suitable for forming a resin layer in which the fracture energy, storage modulus at 25°C, and Young's modulus are adjusted to a specific range. As described above, the inventor has completed the present invention.

[0011] The laminate of the present invention (hereinafter, with respect to matters common to the first laminate and the second laminate, it will also be referred to as "the laminate of the present invention") comprises a thin glass sheet with a thickness of 200 μm or less and a resin layer with a thickness of 5 μm or more disposed on at least one side of the thin glass sheet. The resin layer only needs to be at least one layer in the laminate of the present invention. For example, one or more resin layers may be disposed on one side of the thin glass sheet, or one or more resin layers may be disposed on both sides. Furthermore, the laminate of the present invention may have other layers besides the thin glass sheet and the resin layer. For example, the resin layer may be laminated with the thin glass sheet via an adhesive layer, but it is preferable that it be in direct contact with the thin glass sheet without an adhesive layer. From the viewpoint of taking advantage of the benefits of using flexible thin glass sheet, a configuration in which only one resin layer is disposed on one side of the thin glass sheet, or a configuration in which one resin layer is disposed on each side is preferred. When providing the resin layer without an adhesive layer, a preferred method is to form the resin layer by applying a resin composition, which will be the material for the resin layer, onto the surface of the thin glass sheet and curing it.

[0012] Furthermore, it is preferable that the laminate of the present invention has the thin glass sheet or the resin layer placed on the outermost surface. That is, the laminate of the present invention may have a configuration in which the thin glass sheet is placed on the outermost surface and the resin layer is placed below it, or it may have a configuration in which the resin layer is placed on the outermost surface and the thin glass sheet is placed below it. Among these, the configuration in which the thin glass sheet is placed on the outermost surface and the resin layer is placed below it is particularly preferable from the viewpoint of achieving both the scratch resistance of the glass and the improved impact resistance of the resin layer.

[0013] Preferably, the resin layer covers 80% or more of the surface area of ​​the thin glass plate in a plan view, and more preferably covers the entire surface of the thin glass plate.

[0014] The configurations of the first laminate and the second laminate are appropriately selected according to their application, but when used in front of a display device such as an organic electroluminescent display device, they have, for example, the configuration shown in Figure 1. Figure 1 is a schematic cross-sectional view showing an example of the configuration of the laminate of the present invention. In Figure 1, the laminate 10 has a first resin layer 11 on one side (viewing side) of the thin glass plate 12 and a second resin layer 13 on the opposite side (display device side) of the thin glass plate 12 from the first resin layer 11 side, and may be integrated with the polarizing plate 15 by an optical transparent adhesive (OCA) 14.

[0015] The thin glass sheet described above is not particularly limited as long as it is in the form of a plate and has a thickness of 200 μm or less. Examples of the composition of the thin glass sheet include soda-lime glass, borate glass, aluminosilicate glass, and quartz glass. Furthermore, according to the classification by alkali component, alkali-free glass and low-alkali glass are included. From the viewpoint of impact resistance, the thin glass sheet is preferably chemically strengthened glass that has undergone chemical strengthening treatment. Chemically strengthened glass preferably has a compressive stress layer formed on its surface by chemical strengthening treatment (ion exchange treatment).

[0016] The thickness of the thin glass sheet described above is 200 μm or less. A thickness of 200 μm or less allows for the flexibility required for foldable electronic devices. Furthermore, the thinner the thin glass sheet, the more pronounced the improvement in impact resistance due to the resin layer. The thickness of the thin glass sheet is preferably 150 μm or less, more preferably 100 μm or less. Also, the thickness of the thin glass sheet is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 20 μm or more, and particularly preferably 30 μm or more. Having a certain thickness or more of the thin glass sheet allows for both flexibility and impact resistance.

[0017] The light transmittance of the thin glass plate at a wavelength of 550 nm is preferably 85% or higher. The refractive index of the thin glass plate at a wavelength of 550 nm is preferably 1.4 to 1.65.

[0018] The density of the thin plate glass is preferably 2.3 g / cm 3 ~3.0 g / cm 3 and more preferably 2.3 g / cm 3 ~2.7 g / cm 3 .

[0019] The method for producing the glass used for the thin plate glass is not particularly limited. For example, a mixture containing main raw materials such as silica and alumina, defoaming agents such as sodium sulfate and antimony oxide, and reducing agents such as carbon is melted at a temperature of 1400°C to 1600°C, formed into a thin plate shape, and then cooled to produce it. Examples of the method for forming the thin plate of the glass include the slot down draw method, the fusion method, the float method, etc. The glass formed into a plate shape by these methods may be chemically polished with a solvent such as hydrofluoric acid as necessary to make it thinner or improve its smoothness.

[0020] In the case of chemically strengthened glass, a chemical strengthening treatment is performed. In the chemical strengthening treatment, the surface of the glass is ion-exchanged to form a surface layer (compressive stress layer) in which compressive stress remains. Specifically, at a temperature below the glass transition point, alkali metal ions with a small ionic radius (typically, Li ions or Na ions) present near the surface of the glass plate are replaced with alkali ions with a larger ionic radius (typically, Na ions or K ions for Li ions, and K ions for Na ions) by ion exchange. As a result, compressive stress remains on the surface of the glass, and the strength of the glass is improved.

[0021] The above thin plate glass may be used as it is a commercially available product, or a commercially available glass may be used after additional treatments such as polishing and etching to obtain a desired thickness.

[0022] <The first laminate> The resin layer has a fracture energy of 1 mJ / mm 3 or more. The fracture energy of the resin layer is 1 mJ / mm 3As a result, sufficient impact resistance can be provided to thin glass, which has been thinned to realize foldable electronic devices. The breaking energy is preferably 1.5 mJ / mm 3 The above is more preferable to 2 mJ / mm 3 That concludes the explanation. Furthermore, while there is no particular upper limit to the fracture energy, from the viewpoint of ensuring other properties of the laminate, for example, 50 mJ / mm² is recommended. 3 The following applies:

[0023] The above fracture energy measurement was performed in accordance with JIS K7113 "Tensile Test Method for Plastics," using test specimens prepared according to the following procedure. A 0.7 mm thick glass plate was placed with the release side of a release-treated polyethylene terephthalate resin film facing upwards, and a 0.5 mm thick silicone sheet mold, punched into a dumbbell shape (SDK-400), was then placed on top. The resin composition used to form the resin layer was poured into the dumbbell mold, and the resin liquid was covered with the release side of the release-treated polyethylene terephthalate resin film to prevent air bubbles from being trapped, after which another glass plate was placed on top. Next, a wavelength of 365 nm and an illuminance of 100 mW / cm were used. 2 The UV LED was used as a light source and exposed to a glass plate for 15 seconds, resulting in a reading of 1500 mJ / cm². 2 Ultraviolet light is irradiated onto the specimen. Then, while still sandwiched between glass plates, the specimen is flipped over and irradiated again with the same ultraviolet light from the back. After that, the resin is heated in an 80°C oven for 30 minutes to cure it, and the cured resin is removed from the silicone sheet mold to create a test specimen. A tensile test is performed on this specimen using a tensile testing machine. The tensile test is performed with a chuck distance of 25 mm, a tensile speed of 50 mm / min, and a sampling interval of 20 μm until the specimen breaks. From the obtained measurement results, a stress-strain curve is created with stress (unit: MPa) on the vertical axis and strain (unit: %) on the horizontal axis, and the fracture energy can be calculated by finding the area enclosed by this stress-strain curve and the horizontal axis.

[0024] When measuring the fracture energy of the resin layer directly from the laminate, the resin layer is punched out in a dumbbell shape (SDK-400) and used as the test specimen. Alternatively, the resin layer is dissolved in a solvent to form a resin liquid, which is then poured into the dumbbell mold and allowed to dry completely to create the test specimen.

[0025] The resin layer preferably has a Young's modulus of 1500 MPa or less. A Young's modulus of 1500 MPa or less allows for appropriate flexibility of the resin layer, which is preferable for creating a laminate with the flexibility required to realize foldable electronic devices. It also prevents the resin film from shattering when the glass breaks, thus providing a shatterproof effect. The Young's modulus is more preferably 1300 MPa or less, and even more preferably 1200 MPa or less. The lower limit of the Young's modulus is not particularly limited, but from the viewpoint of ensuring the impact resistance of the laminate, it is preferably 50 MPa or more. The Young's modulus can be calculated by creating a stress-strain curve in the same manner as in the measurement of the fracture energy, and determining the slope of this stress-strain curve when the strain is between 0 and 10%.

[0026] The above-mentioned resin layer has a storage modulus of 2500 MPa or less at 25°C. A storage modulus of 2500 MPa or less in the resin layer provides sufficient impact resistance to the thin glass. Furthermore, the flexibility of the resin layer can be ensured, allowing for a laminate with the flexibility required to realize foldable electronic devices. The above-mentioned storage modulus is preferably 2000 MPa or less, more preferably 1800 MPa or less. While the lower limit of the above-mentioned storage modulus is not particularly limited, from the viewpoint of ensuring the impact resistance of the laminate, it is, for example, 100 MPa or more.

[0027] The storage modulus is measured by stacking two resin cured material test pieces, prepared in the same manner as the fracture energy measurement procedure, to a thickness of 1 mm to create a measurement sample. The storage modulus can then be obtained as the storage modulus at 25°C when the dynamic viscoelastic spectrum of the prepared measurement sample is measured from -50°C to 200°C using a viscoelastic spectrometer (e.g., DVA-200, manufactured by IT Measurement Control Co., Ltd.) under the conditions of a low-speed heating shear deformation mode of 5°C / min and 1 Hz.

[0028] <Second layer> The above resin layer has a Young's modulus of 50 MPa or more and 1500 MPa or less. Having a Young's modulus of 50 MPa or more and 1500 MPa or less in the above resin layer provides adequate flexibility for realizing foldable electronic devices, and also provides sufficient impact resistance to the thin glass used to create foldable electronic devices. The above Young's modulus is preferably 1300 MPa or less, more preferably 1200 MPa or less, and preferably 80 MPa or more.

[0029] The above Young's modulus measurement was performed in accordance with JIS K7113 "Tensile Test Method for Plastics," using test specimens prepared according to the following procedure. A 0.7 mm thick glass plate was placed with the release side of a release-treated polyethylene terephthalate resin film facing upwards, and a 0.5 mm thick silicone sheet mold, punched into a dumbbell shape (SDK-400), was then placed on top. The resin composition used to form the resin layer was poured into the dumbbell mold, and the resin liquid was covered with the release side of the release-treated polyethylene terephthalate resin film to prevent air bubbles from being trapped, after which another glass plate was placed on top. Next, a wavelength of 365 nm and an illuminance of 100 mW / cm were used. 2 The UV LED was used as a light source and exposed to a glass plate for 15 seconds, resulting in a reading of 1500 mJ / cm². 2The specimen is irradiated with ultraviolet light. Then, while still sandwiched between glass plates, it is flipped over and irradiated again with the same ultraviolet light from the back. After that, the resin is heated in an 80°C oven for 30 minutes to cure it, and the cured resin is removed from the silicone sheet mold to create a test specimen. A tensile test is performed on this specimen using a tensile testing machine. The tensile test is performed with a chuck distance of 25 mm, a tensile speed of 50 mm / min, and a sampling interval of 20 μm until the specimen breaks. From the obtained measurement results, a stress-strain curve is created with stress (unit: MPa) on the vertical axis and strain (unit: %) on the horizontal axis, and the value can be calculated by determining the slope of this stress-strain curve when the strain is between 0 and 1%.

[0030] When measuring the Young's modulus of the resin layer directly from the laminate, the resin layer is punched out in a dumbbell shape (SDK-400) and used as the test specimen. Alternatively, the resin layer is dissolved in a solvent to form a resin liquid, which is then poured into the dumbbell mold and allowed to dry completely to create the test specimen.

[0031] The above resin layer has a breaking energy of 1 mJ / mm². 3 Preferably, the above is true. 3 The above conditions can further improve the impact resistance of the laminate. The fracture energy is preferably 1.5 mJ / mm². 3 The above is more preferable to 2 mJ / mm 3 That concludes the explanation. Furthermore, while there is no particular upper limit to the fracture energy, from the viewpoint of ensuring other properties of the laminate, for example, 50 mJ / mm² is recommended. 3 The fracture energy can be calculated by creating a stress-strain curve in the same manner as in the measurement of Young's modulus, and then determining the area of ​​the region enclosed by this stress-strain curve and the horizontal axis.

[0032] The above resin layer preferably has a storage modulus of 2500 MPa or less at 25°C. A storage modulus of 2500 MPa or less ensures the flexibility of the resin layer, which is preferable for creating a laminate with the flexibility required to realize foldable electronic devices. More preferably, the storage modulus is 2000 MPa or less, and even more preferably 1800 MPa or less. Furthermore, the lower limit of the storage modulus is not particularly limited, but from the viewpoint of ensuring the impact resistance of the laminate, it is, for example, 100 MPa or more.

[0033] The storage modulus is measured by stacking two resin cured specimens, prepared in the same manner as the fracture energy measurement procedure, to a thickness of 1 mm, and creating a measurement sample. The storage modulus can then be obtained as the storage modulus at 20°C when the dynamic viscoelastic spectrum of the prepared measurement sample is measured from -50°C to 200°C using a viscoelastic spectrometer (e.g., DVA-200, manufactured by IT Measurement Control Co., Ltd.) under the conditions of a low-speed heating shear deformation mode of 5°C / min and 1 Hz.

[0034] <Laminates 1 and 2> The resin layer described above preferably has a fracture elongation of 5% or more. A fracture elongation of 5% or more in the resin layer makes it less likely to crack or whiten during bending durability tests. A fracture elongation of 7% or more in the resin layer is more preferable. There is no particular upper limit to the fracture elongation, but from the viewpoint of ensuring the impact resistance of the laminate, it is preferable to have an elongation of 1000% or less. The fracture elongation can be determined by performing a tensile test in the same manner as for measuring the fracture energy described above, and using the value of the strain when the test piece fractures.

[0035] The above resin layer preferably has a breaking strength of 5 MPa or more and 50 MPa or less. A breaking strength of the above resin layer within the range of 5 MPa or more and 50 MPa or less makes it easier to impart sufficient impact resistance to thin glass. More preferably, the breaking strength of the above resin layer is 10 MPa or more and 40 MPa or less. The above breaking strength can be determined by performing a tensile test in the same manner as for measuring the breaking energy, and the stress value at which the test piece breaks can be used.

[0036] The resin layer described above preferably has a glass transition temperature of 100°C or lower. A glass transition temperature of 100°C or lower ensures the flexibility of the resin layer, which is preferable for creating a laminate with the flexibility required to realize foldable electronic devices. More preferably, the glass transition temperature is 80°C or lower. Furthermore, the lower limit of the glass transition temperature is not particularly limited, but from the viewpoint of ensuring other properties of the laminate, it is, for example, 0°C or higher. The glass transition temperature can be determined by creating a dynamic viscoelastic spectrum in the same manner as in the measurement of the storage modulus, and using the temperature of the maximum value of the loss tangent.

[0037] The resin layer described above preferably has a total light transmittance of 80% or more. A total light transmittance of 80% or more ensures the transparency of the resin layer, which is preferable for creating a laminate with the transparency required to realize a foldable display. The total light transmittance described above is more preferably 90% or more. The total light transmittance described above can be measured, for example, using a HazeMeter NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.). The total light transmittance described above is measured by a method in accordance with JIS K 7361-1.

[0038] The thickness of the resin layer is 5 μm or more. A resin layer thickness of 5 μm or more allows the flexible resin layer to provide shock absorption, thus granting sufficient impact resistance to the thin glass used to create foldable electronic devices. Preferably, the thickness of the resin layer is 10 μm or more. While there is no particular upper limit to the thickness of the resin layer, from the viewpoint of ensuring the flexibility of the laminate, it is preferable that it be thinner than the thin glass sheet. Specifically, it is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less.

[0039] Furthermore, preferred embodiments of the first laminate and the second laminate include a thin glass sheet with a thickness of 200 μm or less, a first resin layer with a thickness of 5 μm or more disposed on one side of the thin glass sheet, and a second resin layer with a thickness of 5 μm or more disposed on the side of the thin glass sheet opposite to the first resin layer. At least one layer of the first resin layer and the second resin layer is provided within the first laminate and the second laminate. In addition, in the preferred embodiments, the first laminate and the second laminate may have other layers besides the thin glass sheet, the first resin layer and the second resin layer. For example, the first resin layer and the second resin layer may be laminated with the thin glass sheet via an adhesive layer, but it is preferable that they be in direct contact with the thin glass sheet without an adhesive layer. When providing the first resin layer and the second resin layer without an adhesive layer, a preferred method is to form the resin layers by applying a resin composition, which will be the material for the first resin layer and the second resin layer, onto the surface of the thin glass sheet and curing it.

[0040] Preferably, the first resin layer and the second resin layer cover 80% or more of the area of ​​the thin glass sheet in a plan view, and more preferably cover the entire surface of the thin glass sheet.

[0041] <Characteristics of the first and second resin layers of the first laminate> In the first laminate described above, both the first resin layer and the second resin layer have a fracture energy of 1 mJ / mm². 3 The above conditions are met, and it is preferable that the storage modulus at 25°C is 2500 MPa or less. The above fracture energy is 1 mJ / mm 3 As a result, sufficient impact resistance can be provided to thin glass, which has been thinned to realize foldable electronic devices. The breaking energy is more preferably 1.5 mJ / mm 3 The above is preferable to 2 mJ / mm 3 That concludes the explanation. Furthermore, while there is no particular upper limit to the fracture energy, from the viewpoint of ensuring other properties of the laminate, for example, 50 mJ / mm² is recommended. 3The following applies. Furthermore, if the storage modulus is 2500 MPa or less, sufficient impact resistance can be imparted to the thin glass. In addition, the flexibility of the resin layer can be ensured, so a laminate with the flexibility required to realize foldable electronic devices can be made. The storage modulus is more preferably 2000 MPa or less, and even more preferably 1800 MPa or less. Furthermore, the lower limit of the storage modulus is not particularly limited, but from the viewpoint of ensuring the impact resistance of the laminate, it is, for example, 100 MPa or more.

[0042] The above fracture energy measurement can be performed using test specimens prepared according to the following procedure, in accordance with JIS K7113 "Tensile Testing Method for Plastics". A 0.7mm thick glass plate is placed with the release side of a release-treated polyethylene terephthalate resin film facing upwards, and a 0.5mm thick silicone sheet mold, punched into a dumbbell shape (SDK-400), is then placed on top. The resin composition used to form the resin layer is poured into the dumbbell mold, and the resin liquid is covered with the release side of the release-treated polyethylene terephthalate resin film to prevent air bubbles from being trapped, after which another glass plate is placed on top. Next, a wavelength of 365nm and an illuminance of 100mW / cm are applied. 2 The UV LED was used as a light source and exposed to a glass plate for 15 seconds, resulting in a reading of 1500 mJ / cm². 2 Ultraviolet light is irradiated onto the specimen. Then, while still sandwiched between glass plates, the specimen is flipped over and irradiated again with the same ultraviolet light from the back. After that, the resin is heated in an 80°C oven for 30 minutes to cure it, and the cured resin is removed from the silicone sheet mold to create a test specimen. A tensile test is performed on this specimen using a tensile testing machine. The tensile test is performed with a chuck distance of 25 mm, a tensile speed of 50 mm / min, and a sampling interval of 20 μm until the specimen breaks. From the obtained measurement results, a stress-strain curve is created with stress (unit: MPa) on the vertical axis and strain (unit: %) on the horizontal axis, and the fracture energy can be calculated by finding the area enclosed by this stress-strain curve and the horizontal axis.

[0043] When measuring the fracture energy of the resin layer directly from the laminate, the resin layer is punched out in a dumbbell shape (SDK-400) and used as the test specimen. Alternatively, the resin layer is dissolved in a solvent to form a resin liquid, which is then poured into the dumbbell mold and allowed to dry completely to create the test specimen.

[0044] Furthermore, the storage modulus is measured in the same manner as the fracture energy measurement, except that a 0.5 mm thick silicone sheet die, punched into a rectangular shape with a width of 5 mm and a length of 50 mm, is used instead of a dumbbell-shaped (SDK-400) die, to prepare the measurement sample. The storage modulus can then be obtained as the storage modulus at 25°C when the dynamic viscoelastic spectrum of the prepared measurement sample is measured from -50°C to 200°C using a viscoelastic spectrometer (e.g., DVA-200, manufactured by IT Measurement Control Co., Ltd.) under the conditions of a low-speed heating shear deformation mode of 5°C / min and 1 Hz.

[0045] The first resin layer and the second resin layer described above preferably have a Young's modulus of 1500 MPa or less. A Young's modulus of 1500 MPa or less allows for appropriate flexibility of the first and second resin layers, which is preferable for creating a laminate with the flexibility required to realize foldable electronic devices. It also makes it less likely for the resin layer to break simultaneously when the glass breaks, thus providing a shatterproof effect. The Young's modulus is more preferably 1400 MPa or less, and even more preferably 1300 MPa or less. Furthermore, there is no particular lower limit to the Young's modulus, but from the viewpoint of ensuring the impact resistance of the laminate, it is preferably 50 MPa or more. The Young's modulus can be calculated by creating a stress-strain curve in the same manner as in the measurement of the fracture energy described above, and determining the slope of this stress-strain curve when the strain is between 0 and 10%.

[0046] <Characteristics of the first and second resin layers in the second laminate> In the second laminate described above, it is preferable that both the first resin layer and the second resin layer have a Young's modulus of 50 MPa or more and 1500 MPa or less. A Young's modulus of 50 MPa or more and 1500 MPa or less provides adequate flexibility for realizing foldable electronic devices and also provides sufficient impact resistance to thin glass that has been thinned to realize foldable electronic devices. The Young's modulus is more preferably 1400 MPa or less, even more preferably 1300 MPa or less, and more preferably 80 MPa or more.

[0047] The first resin layer and the second resin layer described above each have a breaking energy of 1 mJ / mm². 3 Preferably, the above fracture energy is 1 mJ / mm 3 The above conditions can further improve the impact resistance of the laminate. The fracture energy is preferably 1.5 mJ / mm². 3 The above is more preferable to 2 mJ / mm 3 That concludes the explanation. Furthermore, while there is no particular upper limit to the fracture energy, from the viewpoint of ensuring other properties of the laminate, for example, 50 mJ / mm² is recommended. 3 The following applies:

[0048] At least one of the first resin layer and the second resin layer has a storage modulus of 3000 MPa or less at 25°C, more preferably 2500 MPa or less, even more preferably 2000 MPa or less, particularly preferably 1800 MPa or less, and especially preferably 1500 MPa or less. By keeping the storage modulus within the above range, the flexibility of the resin layer can be improved, which is preferable for creating a laminate with the flexibility required to realize foldable electronic devices. Furthermore, the lower limit of the storage modulus is not particularly limited, but from the viewpoint of ensuring the impact resistance of the laminate, it is preferably 10 MPa or more, more preferably 100 MPa or more, and even more preferably 500 MPa or more. From the viewpoint of improving the foldability of the laminate, it is preferable that both the first resin layer and the second resin layer have a storage modulus of 2500 MPa or less at 25°C. From the viewpoint of ensuring the impact resistance of the laminate, it is preferable that both the first resin layer and the second resin layer have a storage modulus of 100 MPa or more at 25°C.

[0049] <Characteristics of the first and second resin layers common to the first and second laminates> The first resin layer and the second resin layer described above preferably have a fracture elongation of 5% or more. A fracture elongation of 5% or more makes it less likely for cracks or whitening to occur in bending durability tests. A fracture elongation of 7% or more is more preferable. There is no particular upper limit to the fracture elongation, but from the viewpoint of ensuring the impact resistance of the laminate, it is preferable to be 1000% or less. The fracture elongation can be determined by performing a tensile test in the same manner as the measurement of fracture energy described above, and using the value of the strain when the test piece fractures.

[0050] The first resin layer and the second resin layer described above preferably have a breaking strength of 5 MPa or more and 50 MPa or less. A breaking strength within the range of 5 MPa or more and 50 MPa or less makes it easier to impart sufficient impact resistance to thin glass. A breaking strength of 10 MPa or more and 40 MPa or less is more preferable. The breaking strength can be determined by performing a tensile test in the same manner as for measuring the breaking energy, and the stress value at the time the test piece breaks can be used.

[0051] The first resin layer and the second resin layer each preferably have a glass transition temperature of 100°C or less, and it is preferable that at least one of the first resin layer and the second resin layer has a glass transition temperature of 100°C or less. A glass transition temperature of 100°C or less for the resin layer ensures the flexibility of the resin layer, which is preferable for creating a laminate with the flexibility required to realize foldable electronic devices. The glass transition temperature is more preferably 80°C or less, and even more preferably 60°C or less. Furthermore, the lower limit of the glass transition temperature is not particularly limited, but from the viewpoint of ensuring other properties of the laminate, it is, for example, 0°C or higher. The glass transition temperature can be determined by creating a dynamic viscoelastic spectrum in the same manner as in the measurement of the storage modulus, and using the temperature of the maximum value of the loss tangent.

[0052] The first resin layer and the second resin layer described above preferably have a total light transmittance of 80% or more. A total light transmittance of 80% or more of the resin layer ensures the transparency of the resin layer, which is preferable for creating a laminate with the transparency required to realize a foldable display. The total light transmittance described above is more preferably 90% or more. The total light transmittance described above can be measured, for example, using a HazeMeterNDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.). The total light transmittance described above is measured by a method in accordance with JIS K 7361-1.

[0053] The thickness of the first resin layer and the second resin layer is preferably 5 μm or more. A resin layer thickness of 5 μm or more allows the flexible resin layer to exhibit a shock-absorbing function, providing sufficient impact resistance to the thin glass thinned to realize foldable electronic devices. More preferably, the thickness of the first resin layer and the second resin layer is 10 μm or more. While there is no particular upper limit to the thickness of the first resin layer and the second resin layer, from the viewpoint of ensuring the bendability of the laminate, it is preferable that they be thinner than thin glass sheets. Specifically, they are preferably 100 μm or less, more preferably 50 μm or less, even more preferably 30 μm or less, particularly preferably 25 μm or less, and most preferably 20 μm or less. From the viewpoint of ensuring the bendability of the laminate, it is preferable that at least one of the first resin layer and the second resin layer has a thickness of 25 μm or less.

[0054] The following describes the materials that can be used in the resin layer, the first resin layer, and the second resin layer. The resin composition used to form the above-mentioned resin layer, the first resin layer, and the second resin layer is not particularly limited as long as it can adjust the properties of the resin layer obtained after curing to a desired range. For example, a composition containing a cationic curable resin is preferably used because it has excellent adhesion to glass. It is preferable that at least one of the first resin layer and the second resin layer contains a polymer of a cationic curable resin, and it is more preferable that both the first resin layer and the second resin layer contain a polymer of a cationic curable resin.

[0055] The above-mentioned cationic curable resin is not particularly limited as long as it is a compound having at least one cationic polymerizable functional group in its molecule and exhibiting high cationic polymerizability. Examples of the cationic polymerizable functional groups mentioned above include epoxy groups, oxetanyl groups, vinyl ether groups, episulfide groups, and ethyleneimine groups. In particular, the cationic curable resin preferably contains at least one of the following resins: epoxy resin (epoxy group-containing compound), oxetane resin (oxetanyl group-containing compound), and vinyl ether resin (vinyl ether group-containing compound), and more preferably contains epoxy resin (epoxy group-containing compound) and oxetane resin (oxetanyl group-containing compound). Since epoxy resin and oxetane resin have excellent adhesion to the thin glass sheet, peeling of the resin layer can be suppressed when the laminate of the present invention is repeatedly bent.

[0056] The epoxy resin (epoxy group-containing compound) mentioned above is not particularly limited and includes, for example, bisphenol-type epoxy resins such as bisphenol A type, bisphenol F type, bisphenol AD ​​type, and bisphenol S type; novolac-type epoxy resins such as phenol novolac type and cresol novolac type; aromatic epoxy resins such as resorcinol-type epoxy resin and trisphenolmethane triglycidyl ether; alicyclic epoxy resins; naphthalene-type epoxy resins; fluorene-type epoxy resins; dicyclopentadiene-type epoxy resins; polyether-modified epoxy resins such as epoxy resins having a polyether skeleton; NBR-modified epoxy resins; CTBN-modified epoxy resins; and hydrogenated versions thereof. Among these, hydrogenated bisphenol-type epoxy resins and epoxy resins having a polyether skeleton are preferably used. These epoxy resins may be used individually or in combination of two or more types.

[0057] The above-mentioned hydrogenated bisphenol-type epoxy resin is preferably a hydrogenated bisphenol A-type epoxy resin containing a hydrogenated bisphenol A skeleton. The above-mentioned hydrogenated bisphenol-type epoxy resin may also be a polymer such as a dimer. The epoxy equivalent of the above-mentioned hydrogenated bisphenol-type epoxy resin is preferably 100 to 2000. By having an epoxy equivalent of 100 to 2000, the crosslinking density of the epoxy resin can be controlled within a desirable range, and the impact resistance can be further improved. The above-mentioned epoxy equivalent is defined as "the mass of resin containing one equivalent of epoxy groups" and is measured by a method in accordance with JIS K7236.

[0058] Examples of the above-mentioned alicyclic epoxy resins include 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, bis(3,4-epoxycyclohexyl) adipate, 1,2-epoxy-4-vinylcyclohexane, 1,4-cyclohexanedimethanol diglycidyl ether, epoxyethyldivinylcyclohexane, diepoxyvinylcyclohexane, 1,2,4-triepoxyethylcyclohexane, limonene dioxide, and alicyclic epoxy group-containing silicone oligomers. These alicyclic epoxy resins may be used individually or in combination of two or more types.

[0059] The epoxy resin described above may be a liquid epoxy resin at room temperature (23°C) or a solid epoxy resin at room temperature, and these may be used in appropriate combinations. Preferably, the epoxy resin contains at least one epoxy resin that is liquid at room temperature. For example, a hydrogenated bisphenol type epoxy resin that is liquid at room temperature and an epoxy resin having a polyether skeleton that is liquid at room temperature are preferably used. Examples of epoxy resins that are liquid at room temperature include polyether-backed epoxy resins such as "jER YX7400" and "jER YX7400N" (both manufactured by Mitsubishi Chemical Corporation), bisphenol A type epoxy resins such as "EPICLON 840", "EPICLON 840-S", "EPICLON 850", "EPICLON 850-S", and "EPICLON EXA-850CRP" (all manufactured by DIC Corporation), bisphenol F type epoxy resins such as "EPICLON 830", "EPICLON 830-S", "EPICLON EXA-830CRP", "EPICLON EXA-830LVP" (all manufactured by DIC Corporation), and "jER 806H" (manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resins such as "EPICLON HP-4032" and "EPICLON HP-4032D" (both manufactured by DIC Corporation), and "jER YX8000", "jER Hydrogenated bisphenol A epoxy resins such as YX8034, jER YX8040 (both manufactured by Mitsubishi Chemical Corporation), EPICLON EXA-7015 (manufactured by DIC Corporation), EX-252 (manufactured by Nagase ChemteX Corporation); Resorcinol-type epoxy resins such as EX-201 (manufactured by Nagase ChemteX Corporation); Celloxide 2081, Celloxide 2021P, Celloxide 2000, Celloxide 3000, Celloxide 8000, Celloxide 8010, EHPE3150 (all manufactured by Daicel Corporation), TTA21 (manufactured by Jiangsu TetraChem), and Licaresin. Alicyclic epoxy resins such as "DME-100" (manufactured by Shin-Nippon Rika Co., Ltd.), "X-40-2670", "X-22-169AS", and "X-22-169B" (manufactured by Shin-Etsu Chemical Co., Ltd.) are available commercially.

[0060] Examples of epoxy resins that are solid at room temperature include, for example, bisphenol A type epoxy resins such as "EPICLON 860," "EPICLON 10550," and "EPICLON 1055" (all manufactured by DIC Corporation); bisphenol F type epoxy resins such as "jER 4005P" (manufactured by Mitsubishi Chemical Corporation); bisphenol S type epoxy resins such as "EPICLON EXA-1514" (manufactured by DIC Corporation); naphthalene type epoxy resins such as "EPICLON HP-4700," "EPICLON HP-4710," and "EPICLON HP-4770" (all manufactured by DIC Corporation); dicyclopentadiene type epoxy resins such as the "EPICLON HP-7200 series" (manufactured by DIC Corporation); and cresol novolac type epoxy resins such as "EPICLON HP-5000" and "EPICLON EXA-9900" (both manufactured by DIC Corporation), which are commercially available.

[0061] Furthermore, the oxetane resin (oxetanyl group-containing compound), which is the cationic curable resin mentioned above, is not particularly limited. Examples include 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane, 3-ethyl-3-hydroxymethyloxetane, 1,4-bis([(3-ethyl-3-oxetanyl)methoxy]methyl)benzene, 3-ethyl-3-(phenoxymethyl)oxetane, bis[(3-ethyloxetan-3-yl)methyl]ether, 3-ethyl-3-([3-(triethoxysilyl)propoxy]methyl)oxetane, oxetanylsilsesquioxane, and the like. Monofunctional oxetane resins are preferably used. Examples of the oxetane resins mentioned above include "ETRENACOLL EHO" (manufactured by Ube Industries), "Aron Oxetane OXT-101", "Aron Oxetane OXT-121", "Aron Oxetane OXT-211", "Aron Oxetane OXT-221", and "Aron Oxetane OXT-610" (all manufactured by Toagosei Co., Ltd.), which are commercially available. These can be used individually or in combination of two or more types.

[0062] Furthermore, the vinyl ether resin (vinyl ether group-containing compound), which is the cationic curable resin mentioned above, is not particularly limited. For example, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, allyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, isopentyl vinyl ether, tert-pentyl vinyl ether, n-hexyl vinyl ether, isohexyl vinyl ether, 2-ethylhexyl vinyl ether, n-heptyl vinyl ether, n-octyl vinyl ether, nonyl vinyl ether, decyl vinyl ether, dodecyl vinyl ether, hexadecyl vinyl ether, octadecyl vinyl ether, ethoxymethyl vinyl ether, 2-methoxyethyl vinyl ether, 2-ethoxyethyl vinyl ether, 2-butoxyethyl vinyl ether, acetoxymethyl vinyl ether, 2-acetoxyethyl vinyl ether, 3-acetoxypropyl vinyl ether, 4-acetoxybutyl vinyl ether, 4-ethoxybutyl vinyl ether, 2 -(2-methoxyethoxy)ethyl vinyl ether, 3-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, diethylene glycol monovinyl ether, diethylene glycol methyl vinyl ether, diethylene glycol ethyl vinyl ether, triethylene glycol monovinyl ether, tetraethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, propylene glycol monovinyl ether, dipropylene glycol monovinyl ether, tripropylene glycol monovinyl ether, polypropylene glycol monovinyl ether, 4-hydroxycyclohexyl vinyl ether, cyclohexyl dimethanol monovinyl ether, trimethylolpropane monovinyl ether, ethylene oxide-added trimethylolpropane monovinyl ether, pentaerythritol monovinyl ether, ethylene oxide-added pentaerythritol monovinyl ether, cyclohexyl vinyl ether, cyclohexyl methyl vinyl ether,Cyclohexylethyl vinyl ether, menthyl vinyl ether, tetrahydrofurfuryl vinyl ether, norborneyl vinyl ether, 1-adamantyl vinyl ether, 2-adamantyl vinyl ether, phenyl vinyl ether, benzyl vinyl ether, 1-naphthyl vinyl ether, 2-naphthyl vinyl ether, glycidyl vinyl ether, diethylene glycol ethyl vinyl ether, triethylene glycol methyl vinyl ether, divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, tripropylene glycol divinyl ether, polypropylene glycol divinyl ether, butanediol divinyl ether, neopentyl glycol di Examples include vinyl ethers, hexanediol divinyl ethers, nonanediol divinyl ethers, hydroquinone divinyl ethers, 1,4-cyclohexanediol divinyl ethers, 1,4-cyclohexanedimethanol divinyl ethers, trimethylolpropane divinyl ethers, ethylene oxide-added trimethylolpropane divinyl ethers, pentaerythritol divinyl ethers, ethylene oxide-added pentaerythritol divinyl ethers, trimethylolpropane trivinyl ethers, ethylene oxide-added trimethylolpropane trivinyl ethers, pentaerythritol trivinyl ethers, ethylene oxide-added pentaerythritol trivinyl ethers, pentaerythritol tetravinyl ethers, ethylene oxide-added pentaerythritol tetravinyl ethers, ditrimethylolpropane tetravinyl ethers, dipentaerythritol hexanyl ethers, etc. These can be used individually or in combination of two or more.

[0063] The cationic curable resins mentioned above are preferably hydrogenated bisphenol-type epoxy resins, epoxy resins having a polyether skeleton, and compounds containing oxetanyl groups. Such cationic curable resins provide particularly excellent impact resistance, and therefore yield good results in evaluations of splash prevention by pen drop tests.

[0064] The content of the above-mentioned hydrogenated bisphenol type epoxy resin is not particularly limited, but it is preferably 20% by weight or more, more preferably 40% by weight or more, preferably 70% by weight or less, and more preferably 50% by weight or less, based on the total amount of the resin layer containing the above-mentioned cationically curable resin polymer. The content of the epoxy resin having the polyether skeleton is not particularly limited, but is preferably 10% by weight or more, more preferably 12% by weight or more, preferably 40% by weight or less, more preferably 30% by weight or less, and even more preferably 20% by weight or less, relative to the total amount of the resin layer containing the polymer of the cationic curable resin. The content of the oxetanyl group-containing compound is not particularly limited, but is preferably 10% by weight or more, more preferably 20% by weight or more, preferably 70% by weight or less, more preferably 60% by weight or less, and even more preferably 50% by weight or less, relative to the total amount of the resin layer containing the cationically curable resin polymer. Preferably, the content of the hydrogenated bisphenol type epoxy resin in the resin layer containing the polymer of the cationic curable resin is 20% by weight or more and 60% by weight or less, the content of the epoxy resin having a polyether skeleton is 10% by weight or more and 20% by weight or less, and the content of the oxetanyl group-containing compound is 20% by weight or more and 60% by weight or less.

[0065] The above resin composition preferably contains a polymerization initiator. The polymerization initiator may be a photopolymerization initiator or a thermal polymerization initiator. Examples of photopolymerization initiators include compounds consisting of a combination of a cation such as diphenyliodonium, 4-methoxydiphenyliodonium, bis(4-methylphenyl)iodonium, bis(4-tert-butylphenyl)iodonium, bis(dodecylphenyl)iodonium, diphenyl-4-thiophenoxyphenylsulfonium, bis[4-(diphenylsulfonio)-phenyl]sulfide, bis[4-(di(4-(2-hydroxyethyl)phenyl)sulfonio)-phenyl]sulfide, and η5-2,4-(cyclopentagenyl)[1,2,3,4,5,6-η-(methylethyl)benzene]-iron(1+) and an anion such as tetrafluoroborate, hexafluorophosphate, triphenylhexafluorophosphate, and hexafluoroarcenate. Examples of thermal polymerization initiators include imidazoles, quaternary ammonium salts, phosphorus compounds, amines, phosphines, phosphonium salts, bicyclic amidines and their salts, acid anhydrides, phenols, cresols, xylenols, resolcins, etc., novolac-type phenolic resins obtained by condensation reaction with formaldehyde, polymercapto resins such as liquid polymercaptans and polysulfides, and amides. These polymerization initiators may be used alone or in combination of two or more.

[0066] The content of the polymerization initiator is preferably 0.1 parts by weight and preferably 10 parts by weight per 100 parts by weight of the cationic curable resin. If the content of the polymerization initiator is less than 0.1 parts by weight, cationic polymerization may not proceed sufficiently, or the curing reaction may be too slow. If the content of the polymerization initiator exceeds 10 parts by weight, the curing reaction of the resin composition may be too fast, resulting in reduced workability or an uneven composition of the resulting resin layer. A more preferable lower limit for the content of the polymerization initiator is 0.5 parts by weight and a more preferable upper limit is 5 parts by weight.

[0067] The above resin composition may further contain various known additives, such as solvents, viscosity modifiers, surface modifiers (surfactants, leveling agents), plasticizers, silane coupling agents, tackifiers, sensitizers, thermosetting agents, crosslinking agents, curing retarders, antioxidants, storage stabilizers, dispersants, and fillers, to the extent that they do not impede the objectives of the present invention.

[0068] The method for preparing the above resin composition is not particularly limited, and examples include mixing a curable resin, a polymerization initiator, and additives as needed using a mixer. Examples of such mixers include homodispers, homomixers, universal mixers, planetary mixers, kneaders, and three-roll mixers.

[0069] The method for forming the above-mentioned resin layer, the first resin layer, and the second resin layer is not particularly limited. For example, they can be formed by applying the resin composition to the surface of the thin glass sheet and then curing it by light irradiation, heating, etc. The method for applying the resin composition is not particularly limited. For example, screen printing, die-coating, offset printing, gravure printing, inkjet printing, etc., may be used.

[0070] Furthermore, an electronic device comprising the laminate of the present invention is also one of the present inventions. As the electronic device of the present invention, a foldable electronic device is preferred, and among these, a foldable display device is preferred. Specifically, examples include portable display terminals such as smartphones, e-books, and tablet PCs. In a display device comprising the first laminate or the second laminate, it is preferable that the first resin layer is arranged on the viewing side and the second resin layer is arranged on the display device side.

[0071] Furthermore, a cover glass comprising the laminate of the present invention is also one of the present inventions. The cover glass of the present invention is preferably a protective glass that is arranged to cover an article to be protected, and more preferably the article to be protected is a display cover glass that is a display device.

[0072] Furthermore, the resin composition used to form the resin layer of the laminate of the present invention is also one of the present inventions. The resin composition of the present invention can exhibit excellent impact resistance after curing and is a resin composition suitable for forming a thin film to protect an adherend such as glass.

[0073] The composition of the resin composition of the present invention is the same as that of the resin composition used to form the above-mentioned resin layer, the first resin layer, and the second resin layer. The resin composition of the present invention preferably comprises a hydrogenated bisphenol-type epoxy resin, an epoxy resin having a polyether skeleton, and an oxetanyl group-containing compound. Such a resin composition provides particularly excellent impact resistance, and therefore yields good results in evaluations of splash resistance by pen drop tests.

[0074] The above-mentioned hydrogenated bisphenol-type epoxy resin is preferably a hydrogenated bisphenol A-type epoxy resin containing a hydrogenated bisphenol A skeleton. The above-mentioned hydrogenated bisphenol-type epoxy resin may also be a polymer such as a dimer. The epoxy equivalent of the above-mentioned hydrogenated bisphenol-type epoxy resin is preferably 100 to 2000. The above-mentioned hydrogenated bisphenol-type epoxy resin is preferably used in liquid form at room temperature (23°C). The hydrogenated bisphenol-type epoxy resin may be used alone or in combination of two or more types. The epoxy resin having the polyether skeleton described above is preferably one that is liquid at room temperature (23°C). The epoxy resin having the polyether skeleton may be used alone or in combination of two or more types. The oxetanyl group-containing compound (oxetane resin) described above is preferably a monofunctional compound. The oxetanyl group-containing compound may be used alone or in combination of two or more types.

[0075] The content of the above-mentioned hydrogenated bisphenol type epoxy resin is not particularly limited, but it is preferably 20% by weight or more, more preferably 40% by weight or more, preferably 70% by weight or less, and more preferably 50% by weight or less, based on the total amount of the resin composition of the present invention. The content of the epoxy resin having the polyether skeleton described above is not particularly limited, but is preferably 10% by weight or more, more preferably 12% by weight or more, preferably 40% by weight or less, more preferably 30% by weight or less, and even more preferably 20% by weight or less, based on the total amount of the resin composition of the present invention. The content of the oxetanyl group-containing compound is not particularly limited, but is preferably 10% by weight or more, more preferably 20% by weight or more, preferably 70% by weight or less, more preferably 60% by weight or less, and even more preferably 50% by weight or less, based on the total amount of the resin composition of the present invention. Preferably, the resin composition of the present invention contains 20% to 60% by weight of the hydrogenated bisphenol type epoxy resin, 10% to 20% by weight of the epoxy resin having a polyether skeleton, and 20% to 60% by weight of the oxetanyl group-containing compound.

[0076] The above resin composition is preferably a resin composition used for coating thin glass sheets with a thickness of 200 μm or less.

[0077] The above resin composition may contain a solvent from the viewpoint of coating properties, etc. From the viewpoint of coating properties and storage stability, a nonpolar solvent or an aprotic polar solvent with a boiling point of 200°C or less is preferred as the above solvent. Examples of the above nonpolar solvent or aprotic polar solvent with a boiling point of 200°C or less include ketone solvents, ester solvents, hydrocarbon solvents, halogen solvents, ether solvents, nitrogen-containing solvents, etc. From the viewpoint of coating stability, uniformity of the coating film, and drying efficiency, the boiling point of the above nonpolar solvent or aprotic polar solvent is more preferably in the range of 80°C to 180°C.

[0078] The above resin composition preferably has a viscosity of 1 to 1000 mPa·s at 25°C, as measured using an E-type viscometer. A more preferable range of viscosity is adjusted depending on the coating method. For example, a range of 5 to 50 mPa·s is preferred for inkjet coating, a range of 10 to 100 mPa·s is preferred for slit coating, and a range of 100 to 1000 mPa·s is preferred for roll coating and offset printing. On the other hand, if the viscosity exceeds 1000 mPa·s, the leveling properties of the coating liquid tend to decrease, and the uniformity of the coating film thickness tends to decrease. The viscosity can be measured, for example, using a VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) as an E-type viscometer, by selecting a rotation speed of 1 to 100 rpm from the optimal torque number for each viscosity range using the CP1 cone plate. [Effects of the Invention]

[0079] According to the present invention, a laminate with excellent impact resistance can be provided. Furthermore, according to the present invention, an electronic device and a cover glass using the laminate, and a resin composition used to form the resin layer of the laminate can be provided. [Brief explanation of the drawing]

[0080] [Figure 1] This is a schematic cross-sectional view showing an example of the structure of the laminate of the present invention. [Modes for carrying out the invention]

[0081] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0082] (Examples 1-12, Comparative Examples 1-3) According to the mixing ratios listed in Table 1 below, the curable resin shown in (1), the initiator shown in (2), and the surface modifier shown in (3) were stirred and mixed to obtain a resin composition. The obtained resin composition was diluted with the solvent propylene glycol monomethyl ether acetate to adjust its viscosity, and coated onto a 50 μm thick glass plate to a thickness of 10 μm after drying. The obtained coating was dried at a temperature of 100°C for 15 minutes, and then irradiated with ultraviolet light at a wavelength of 365 nm at a dose of 1500 mJ / cm². 2 The resin was cured by irradiation and then heating at 80°C for 30 minutes. As a result, a laminate was obtained in which a resin layer made of cured resin was formed on one side of a thin glass sheet.

[0083] (1) Curing resin • EPICLON EXA-830LVP (a mixture of bisphenol F type liquid epoxy resin and bisphenol A type liquid epoxy resin, manufactured by DIC Corporation) • jER YX7400 (Polyether-backed liquid epoxy resin, manufactured by Mitsubishi Chemical Corporation) • jER 4005P (Bisphenol F type solid epoxy resin, manufactured by Mitsubishi Chemical Corporation) • jER 806H (Bisphenol F type liquid epoxy resin, manufactured by Mitsubishi Chemical Corporation) • jER YX8000 (Hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 192-220) jER YX8034 (Hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 250-360) jER YX8040 (Hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 900-1500) • Celoxide 2021P (3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, manufactured by Daicel Corporation) • ETRENACOLL EHO (3-ethyl-3-hydroxymethyloxetane, manufactured by Ube Industries, Ltd.)

[0084] (2) Initiator • CPI-210S (Triarylsulfonium salt type photocationic polymerization initiator, manufactured by Sunapro Co., Ltd.)

[0085] (3) Surface modifiers • JAR-33 (organically modified polysiloxane, manufactured by Jujo Chemical Co., Ltd.)

[0086] (Comparative Example 4) Comparative Example 4 used thin glass sheets with the same thickness of 50 μm as Examples 1-5 and Comparative Examples 1-3, where no resin layer was formed on the surface.

[0087] <Physical property measurement> The physical properties of the cured resin products prepared using the resin compositions of Examples 1-12 and Comparative Examples 1-3 were measured by the following method. The results are shown in Table 1.

[0088] (Storage modulus and glass transition temperature) Test specimens of cured resin were stacked to a thickness of 1 mm to prepare measurement samples. The dynamic viscoelastic spectra of the prepared measurement samples were measured from -50°C to 200°C using a viscoelastic spectrometer (IT Measurement Control Co., Ltd., DVA-200) under the conditions of a low-speed heating shear deformation mode at 5°C / min and 1 Hz. The storage modulus at 25°C was calculated from the obtained dynamic viscoelastic spectra. The temperature at which the loss tangent was maximized was defined as the glass transition temperature Tg (°C).

[0089] (Young's modulus, elongation at break, strength at break, energy at break) In accordance with JIS K7113 "Tensile Testing Method for Plastics," 0.5 mm thick resin cured material was molded into a dumbbell shape (SDK-400) and subjected to tensile testing using a tensile testing machine. The tensile test was performed with a chuck distance of 20 mm, a tensile speed of 50 mm / min, and a sampling interval of 20 μm, until the specimen fractured. From the obtained measurement results, a stress-strain curve was created with stress (in MPa) on the vertical axis and strain (in %) on the horizontal axis. The value of the strain at the time of fracture was defined as the elongation at fracture, and the value of the maximum stress at the time of fracture was defined as the fracture strength. Young's modulus was calculated by determining the slope of the stress-strain curve at strains of 0 to 10%. The fracture energy was calculated by determining the area enclosed by the stress-strain curve and the horizontal axis.

[0090] <Rating> The laminates obtained in Examples 1-12 and Comparative Examples 1-3, as well as the thin glass sheet of Comparative Example 4, were evaluated as follows. The results are shown in Table 1.

[0091] (Total light transmittance and haze) Total light transmittance and haze were measured using HazeMeterNDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

[0092] (Pendrop test) A laminate was placed on a 10mm thick stainless steel plate with the thin glass side facing upwards. A ballpoint pen (BIC Japan, orange EG0.7, 0.7mm diameter tip, 5.75g weight) was dropped vertically from a predetermined height with the tip facing downwards onto the glass surface of the laminate. The maximum height at which no cracks occurred in the thin glass was recorded as the test result.

[0093] (Splash prevention test) For laminates in which cracks occurred in the thin glass sheets during the pendrop test described above, the shatterproof properties were evaluated based on the following evaluation criteria. ○: Although cracks occurred in the glass, the fragments of glass caused by the cracks were held together by the resin layer, and no separation occurred between the resin layer and the thin glass sheet, resulting in no glass shattering. ×: Cracks occurred in the resin layer simultaneously with the cracking of the thin glass sheet, causing it to break into fragments, or the glass broke into fragments due to the delamination of the resin layer and the thin glass sheet.

[0094] (Bending durability test) A U-bending test machine (Yuasa System Equipment Co., Ltd., DLDMLH-FS) was used to repeatedly bend the laminate so that the thin glass sheet was positioned on the inside when the laminate was bent. The test was performed at a speed of 2 seconds / bend, a bending diameter of R3.0 mm, and 100,000 bends. The laminate was then placed on a horizontal movable plate, and the two movable plates were rotated 90 degrees to bend the laminate into a U-shape. After the test, the appearance of the laminate was visually inspected. If there was no change in appearance before and after the test, it was evaluated as "○○", if cracks or whitening occurred at the ends but not elsewhere after the test, it was evaluated as "○", and if cracks or whitening occurred elsewhere after the test and the appearance changed, it was evaluated as "×".

[0095] [Table 1]

[0096] (Examples 13-25) According to the mixing ratios listed in Table 2 below, the curable resin shown in (1), the initiator shown in (2), and the surface modifier shown in (3) were stirred and mixed to obtain a resin composition. The obtained resin composition was diluted with the solvent propylene glycol monomethyl ether acetate to adjust its viscosity, and coated onto a 50 μm thick glass plate to the dry thickness shown in Table 2 below. The obtained coating was dried at a temperature of 100°C for 15 minutes, and then irradiated with ultraviolet light at a wavelength of 365 nm at a dose of 1500 mJ / cm². 2 The material was cured by irradiation and then heating at 80°C for 30 minutes. As a result, a laminate was obtained in which a first resin layer made of cured resin was provided on one side (viewing side) of the thin glass plate, and a second resin layer made of cured resin was provided on the other side (display element side).

[0097] (1) Curing resin • EPICLON EXA-830LVP (a mixture of bisphenol F type liquid epoxy resin and bisphenol A type liquid epoxy resin, manufactured by DIC Corporation) • jER YX7400N (Polyether-backed liquid epoxy resin, manufactured by Mitsubishi Chemical Corporation) • jER 4005P (Bisphenol F type solid epoxy resin, manufactured by Mitsubishi Chemical Corporation) • jER YX8000 (Hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 192-220) jER YX8034 (Hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 250-360) jER YX8040 (Hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 900-1500) • Celoxide 2021P (3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, manufactured by Daicel Corporation) • ETRENACOLL EHO (3-ethyl-3-hydroxymethyloxetane, manufactured by Ube Industries, Ltd.)

[0098] (2) Initiator • CPI-210S (Triarylsulfonium salt type photocationic polymerization initiator, manufactured by Sunapro Co., Ltd.) • DTS-200 (Aromatic sulfonium salt type photocationic polymerization initiator, manufactured by Midori Chemical Co., Ltd.) (3) Surface modifiers • BYK-340 (manufactured by Big Chemie) • JAR-33 (organically modified polysiloxane, manufactured by Jujo Chemical Co., Ltd.)

[0099] <Physical property measurement> The physical properties of the cured resin products prepared in Examples 13-25 were measured using the following method. The results are shown in Table 2 below.

[0100] (Storage modulus and glass transition temperature) A test specimen of cured resin with a thickness of 0.5 mm, a width of 5 mm, and a length of 50 mm was prepared. Using a viscoelastic spectrometer (IT Measurement Control Co., Ltd., DVA-200), the dynamic viscoelastic spectrum was measured from -50°C to 150°C under tensile mode conditions of 10°C / min and 10 Hz. From the obtained dynamic viscoelastic spectrum, the storage modulus at 25°C was determined. The temperature at which the loss tangent was maximized was defined as the glass transition temperature Tg (°C).

[0101] (Young's modulus, elongation at break, strength at break, energy at break) In accordance with JIS K7113 "Tensile Testing Method for Plastics," 0.5 mm thick resin cured material was molded into a dumbbell shape (SDK-400) and subjected to tensile testing using a tensile testing machine. The tensile test was performed with a chuck distance of 20 mm, a tensile speed of 50 mm / min, and a sampling interval of 20 μm, until the specimen fractured. From the obtained measurement results, a stress-strain curve was created with stress (in MPa) on the vertical axis and strain (in %) on the horizontal axis. The value of the strain at the time of fracture was defined as the elongation at fracture, and the value of the maximum stress at the time of fracture was defined as the fracture strength. Young's modulus was calculated by determining the slope of the stress-strain curve at strains of 0 to 10%. The fracture energy was calculated by determining the area enclosed by the stress-strain curve and the horizontal axis.

[0102] <Rating> The thin glass laminates obtained in Examples 13-25 were evaluated as follows. The results are shown in Table 2 below.

[0103] (Total light transmittance and haze) Total light transmittance and haze were measured using HazeMeterNDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

[0104] (Pendrop test) A 10mm thick artificial marble slab (DuPont, "Corian") was placed with the first resin layer of the laminate facing upwards. A ballpoint pen (BIC Japan, Orange EG0.7, 0.7mm diameter tip, 5.75g weight) was then dropped vertically from a predetermined height with the tip facing downwards, onto the surface of the first resin layer of the laminate. The maximum height at which no cracks occurred in the thin glass sheet was recorded as the test result.

[0105] (Splash prevention test) For laminates in which cracks occurred in the thin glass sheets during the pendrop test described above, the shatterproof properties were evaluated based on the following evaluation criteria. ○: Although cracks occurred in the glass, the fragments of glass caused by the cracks were held together by the resin layer, and no separation occurred between the resin layer and the thin glass sheet, resulting in no glass shattering. ×: Cracks occurred in the resin layer simultaneously with the cracking of the thin glass sheet, causing it to break into fragments, or the glass broke into fragments due to the delamination of the resin layer and the thin glass sheet.

[0106] (Bending durability test) A U-bend test machine (Yuasa System Equipment Co., Ltd., DLDMLH-FS) was used to flex the laminate so that the first resin layer was on the inside when bent. The laminate was repeatedly bent at a test speed of 1 second / bend, a bending diameter of R2.0 mm, and 100,000 bends. After the test, the bent portion of the laminate was visually inspected. "○○" was used to indicate no change in appearance before and after the test, "○" was used to indicate that cracks or whitening occurred at the ends but not elsewhere after the test, and "×" was used to indicate that cracks or whitening occurred elsewhere after the test, resulting in a change in appearance.

[0107] [Table 2] [Industrial applicability]

[0108] According to the present invention, a laminate with excellent impact resistance can be provided. Furthermore, according to the present invention, an electronic device and a cover glass using the laminate, and a resin composition used to form the resin layer of the laminate can be provided. [Explanation of Symbols]

[0109] 10 Laminate 11 First resin layer 12 Thin glass 13. Second resin layer 14. Transparent adhesive for optical applications 15 Polarizing plates

Claims

1. It comprises a thin glass plate with a thickness of 200 μm or less, and a resin layer with a thickness of 5 μm or more, which is disposed on at least one side of the thin glass plate. The rupture energy of the resin layer is 1 mJ / mm ３ The above conditions are met, and the storage modulus at 25°C is 2500 MPa or less. A laminate characterized by the following features.

2. The laminate according to claim 1, wherein the Young's modulus of the resin layer is 50 MPa or more and 1500 MPa or less.

3. The laminate according to claim 1 or 2, wherein the storage modulus of the resin layer at 25°C is 2000 MPa or less.

4. The laminate according to claim 1 or 2, wherein the glass transition temperature of the resin layer is 100°C or less.

5. The laminate according to claim 1 or 2, wherein the resin layer comprises a polymer of a cationic curable resin.

6. The laminate according to claim 5, wherein the cationic curable resin comprises an epoxy group-containing compound and an oxetanyl group-containing compound.

7. The laminate according to claim 6, wherein the epoxy group-containing compound comprises a hydrogenated bisphenol type epoxy resin.

8. The laminate according to claim 7, wherein the hydrogenated bisphenol-type epoxy resin comprises a hydrogenated bisphenol A skeleton.

9. The laminate according to claim 7, wherein the epoxy equivalent of the hydrogenated bisphenol type epoxy resin is 100 or more and 2000 or less.

10. The laminate according to claim 6, wherein the epoxy group-containing compound comprises an epoxy resin having a polyether skeleton.

11. The laminate according to claim 10, wherein the epoxy resin having the polyether skeleton is liquid at 23°C.

12. The laminate according to claim 6, wherein the oxetanyl group-containing compound is monofunctional.

13. The laminate according to claim 5, wherein the cationic curable resin comprises a hydrogenated bisphenol type epoxy resin, an epoxy resin having a polyether skeleton, and an oxetanyl group-containing compound.

14. The laminate according to claim 13, wherein the content of hydrogenated bisphenol type epoxy resin in the resin layer is 20% by weight or more and 60% by weight or less, the content of epoxy resin having a polyether skeleton is 10% by weight or more and 20% by weight or less, and the content of oxetanyl group-containing compound is 20% by weight or more and 60% by weight or less.

15. A first resin layer with a thickness of 5 μm or more is disposed on one side of the thin glass plate, The thin glass plate has a second resin layer with a thickness of 5 μm or more, which is positioned on the side opposite to the first resin layer. Both the first resin layer and the second resin layer have a breaking energy of 1 mJ / mm². ３ The above conditions are met, and the storage modulus at 25°C is 2500 MPa or less. The laminate according to claim 1.

16. The laminate according to claim 6, wherein both the first resin layer and the second resin layer have a Young's modulus of 50 MPa or more and 1500 MPa or less.

17. The laminate according to claim 15 or 16, wherein at least one of the first resin layer and the second resin layer has a thickness of 25 μm or less.

18. The laminate according to claim 15 or 16, wherein at least one of the first resin layer and the second resin layer has a glass transition temperature of 100°C or less.

19. The laminate according to claim 15 or 16, wherein at least one of the first resin layer and the second resin layer comprises a polymer of a cationic curable resin.

20. It comprises a thin glass plate with a thickness of 200 μm or less, and a resin layer with a thickness of 5 μm or more, which is disposed on at least one side of the thin glass plate. The Young's modulus of the resin layer is 50 MPa or more and 1500 MPa or less. A laminate characterized by the following features.

21. The rupture energy of the resin layer is 1 mJ / mm ３ The laminate according to claim 20, wherein the above is true.

22. The laminate according to claim 20 or 21, wherein the storage modulus of the resin layer at 25°C is 2500 MPa or less.

23. The laminate according to claim 20 or 21, wherein the glass transition temperature of the resin layer is 100°C or less.

24. The laminate according to claim 20 or 21, wherein the resin layer comprises a polymer of a cationic curable resin.

25. The laminate according to claim 24, wherein the cationic curable resin comprises an epoxy group-containing compound and an oxetanyl group-containing compound.

26. The laminate according to claim 25, wherein the epoxy group-containing compound comprises a hydrogenated bisphenol type epoxy resin.

27. The laminate according to claim 26, wherein the hydrogenated bisphenol-type epoxy resin comprises a hydrogenated bisphenol A skeleton.

28. The laminate according to claim 26, wherein the epoxy equivalent of the hydrogenated bisphenol type epoxy resin is 100 or more and 2000 or less.

29. The laminate according to claim 25, wherein the epoxy group-containing compound comprises an epoxy resin having a polyether skeleton.

30. The laminate according to claim 29, wherein the epoxy resin having the polyether skeleton is liquid at 23°C.

31. The laminate according to claim 25, wherein the oxetanyl group-containing compound is monofunctional.

32. The laminate according to claim 24, wherein the cationic curable resin comprises a hydrogenated bisphenol type epoxy resin, an epoxy resin having a polyether skeleton, and an oxetanyl group-containing compound.

33. The laminate according to claim 32, wherein the content of hydrogenated bisphenol type epoxy resin in the resin layer is 20% by weight or more and 60% by weight or less, the content of epoxy resin having a polyether skeleton is 10% by weight or more and 20% by weight or less, and the content of oxetanyl group-containing compound is 20% by weight or more and 60% by weight or less.

34. A first resin layer with a thickness of 5 μm or more is disposed on one side of the thin glass plate, The thin glass plate has a second resin layer with a thickness of 5 μm or more, which is positioned on the side opposite to the first resin layer. Both the first resin layer and the second resin layer have a Young's modulus of 50 MPa or more and 1500 MPa or less. The laminate according to claim 20.

35. The laminate according to claim 34, wherein at least one of the first resin layer and the second resin layer has a storage modulus of 3,000 MPa or less at 25°C.

36. The laminate according to claim 34 or 35, wherein at least one of the first resin layer and the second resin layer has a thickness of 25 μm or less.

37. The laminate according to claim 34 or 35, wherein at least one of the first resin layer and the second resin layer has a glass transition temperature of 100°C or less.

38. The laminate according to claim 34 or 35, wherein at least one of the first resin layer and the second resin layer comprises a polymer of a cationic curable resin.

39. The laminate according to claim 38, wherein the cationic curable resin comprises an epoxy group-containing compound and an oxetanyl group-containing compound.

40. The laminate according to claim 39, wherein the epoxy group-containing compound comprises a hydrogenated bisphenol type epoxy resin.

41. The laminate according to claim 40, wherein the hydrogenated bisphenol-type epoxy resin comprises a hydrogenated bisphenol A skeleton.

42. The laminate according to claim 40, wherein the epoxy equivalent of the hydrogenated bisphenol type epoxy resin is 100 or more and 2000 or less.

43. The laminate according to claim 39, wherein the epoxy group-containing compound comprises an epoxy resin having a polyether skeleton.

44. The laminate according to claim 43, wherein the epoxy resin having the polyether skeleton is liquid at 23°C.

45. The laminate according to claim 39, wherein the oxetanyl group-containing compound is monofunctional.

46. The laminate according to claim 38, wherein the cationic curable resin comprises a hydrogenated bisphenol type epoxy resin, an epoxy resin having a polyether skeleton, and an oxetanyl group-containing compound.

47. The laminate according to claim 46, wherein the content of hydrogenated bisphenol type epoxy resin in the resin layer containing the polymer of the cationic curable resin is 20% by weight or more and 60% by weight or less, the content of epoxy resin having a polyether skeleton is 10% by weight or more and 20% by weight or less, and the content of oxetanyl group-containing compound is 20% by weight or more and 60% by weight or less.

48. An electronic device comprising a laminate according to any one of claims 1 to 47.

49. A cover glass comprising a laminate according to any one of claims 1 to 47.

50. A resin composition used to form a resin layer of a laminate according to any one of claims 1 to 47.

51. A resin composition comprising a hydrogenated bisphenol-type epoxy resin, an epoxy resin having a polyether skeleton, and an oxetanyl group-containing compound.

52. The resin composition according to claim 50 or 51, used for coating thin glass sheets with a thickness of 200 μm or less.

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