Laminate

Abstract

The present invention provides a laminate in which the decorative layer adheres well to chemically strengthened glass or alkali-free glass, and the decorative layer is less likely to peel off. [Solution] The laminate 1 comprises a base material 2, an adhesive layer 3 laminated on at least a portion of the base material 2, and a decorative layer 4 formed to contact the adhesive layer 3. The base material 2 is chemically strengthened glass or alkali-free glass. The adhesive layer 3 contains a heat transferable resin. The decorative layer 4 contains a heat transferable resin. The ratio of the thickness of the adhesive layer 3 to the thickness of the decorative layer 4 is preferably 1:0.01 to 1:100. It is preferable to provide an adhesive layer 5 on at least a portion of the base material 2 so as to be in contact with at least one of the adhesive layer 3 and the decorative layer 4.

Description

[Technical Field]

[0001] This invention relates to a laminate. [Background technology]

[0002] OLED (Organic Light Emitting Diode) displays offer several advantages over liquid crystal displays, including higher visibility, less dependence on viewing angle, and faster response times. Furthermore, because OLED displays do not use backlights, they are more suitable for thinner designs and can be used as flexible, curved, or foldable devices.

[0003] In OLED display devices, a laminate is constructed on the viewing side of the OLED element, comprising layers of various optical elements such as an adhesive layer, a substrate such as plastic or thin glass, and a hard coat layer, in order to provide functions such as surface protection and flexibility.

[0004] In such laminates, a decorative layer with reflective or light-shielding properties may be formed on the substrate to prevent external light from penetrating the OLED elements. Since decorative layers generally do not adhere well to thin glass, they are often formed by bonding them to a plastic substrate, and this plastic substrate is then laminated onto the thin glass.

[0005] In recent years, there has been a demand for thinner optical products such as OLED display devices. Therefore, attempts have been made to form decorative layers directly onto thin glass without using plastic substrates (see Patent Documents 1 and 2). Such laminates contribute to thinner designs because they eliminate the need for plastic substrates to form the decorative layer. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2013 / 146183

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] In particular, in a foldable device, even more thinning is required so that it can be easily folded. As such thin glass in a foldable device, chemically strengthened glass or non-alkali glass with high flexural resistance may be used. However, the adhesion of a conventional decorative layer to chemically strengthened glass and non-alkali glass is low, and it has been difficult to form a decorative layer on chemically strengthened glass or non-alkali glass by a conventional method such as screen printing. Further, even if it could be formed, there was a problem that the decorative layer was likely to peel off from chemically strengthened glass or non-alkali glass when impacted or repeatedly folded.

[0008] The present invention has been made in view of the above problems, and an object thereof is to provide a laminate having high adhesion of a decorative layer to chemically strengthened glass or non-alkali glass and in which the decorative layer is difficult to peel off.

Means for Solving the Problems

[0009] As a result of intensive studies to achieve the above object, the present inventors have found that a specific laminate has high adhesion of a decorative layer to chemically strengthened glass and non-alkali glass and in which the decorative layer is difficult to peel off.

[0010] The present invention provides a laminate including a base material, an adhesive layer laminated on at least a part of the base material, and a decorative layer formed so as to contact the adhesive layer, where the base material is chemically strengthened glass or non-alkali glass, the adhesive layer contains a heat-transferable resin, and the decorative layer contains a heat-transferable resin.

[0011] The ratio of the thickness of the adhesive layer to the thickness of the decorative layer is preferably 1:0.01 to 1:100.

[0012] The decorative layer described above preferably contains a pigment.

[0013] The laminate of the present invention may include an adhesive layer on at least a portion of the substrate so as to be in contact with at least one of the adhesive layer and the decorative layer.

[0014] The ratio of the total thickness of the adhesive layer and the decorative layer to the thickness of the adhesive layer is preferably 1:0.5 to 1:2500. [Effects of the Invention]

[0015] In the laminate of the present invention, the decorative layer adheres well to chemically strengthened glass or alkali-free glass, and the decorative layer is less likely to fall off. Therefore, even when used laminated in a foldable device (especially a foldable OLED display device), the decorative layer is less likely to fall off, providing excellent light shielding (light-shielding) and an aesthetically pleasing foldable device. [Brief explanation of the drawing]

[0016] [Figure 1] This is a cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 2] This is a cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 3] This is a cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 4] This is a cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 5] This is a cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 6] This is a cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 7] This is a cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 8] This is a cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 9] This is a cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 10] This is a cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 11] This is a cross-sectional view showing one embodiment of the decorative layer transfer process in a method for manufacturing a laminate. [Figure 12] This is a cross-sectional view showing one embodiment of the adhesive layer transfer process in a method for manufacturing a laminate. [Figure 13] This is a cross-sectional view showing one embodiment of the laminate transfer process in a method for manufacturing a laminate. [Modes for carrying out the invention]

[0017] In this specification, "adhesion" refers to the property of two surfaces adhering tightly to each other based on cohesive forces derived from the chemical structure of the composition in response to external pressure (e.g., minute pressure), and being able to be separated if necessary. In contrast, "bonding" refers to the property of two surfaces being firmly joined together by flow due to heating and subsequent solidification or curing due to cooling, etc., without exhibiting pressure-sensitive adhesion at room temperature and without the intention of separation.

[0018] Furthermore, in this specification, the form of the "adhesive" is not particularly limited and may be liquid at room temperature (for example, a fluid solid (paste), an adhesive composition, etc.), or a solid at room temperature. Also, the form of the "adhesive" is not particularly limited and may be in the form of a sheet. In this specification, the "adhesive layer" is a non-fluid sheet-like (layered) adhesive layer.

[0019] [Laminated structure] The laminate of the present invention comprises at least a base material, an adhesive layer laminated on at least a portion of the base material, and a decorative layer formed to be in contact with the adhesive layer.

[0020] Figures 1 to 10 show cross-sectional views of one embodiment of the laminate of the present invention. The laminate 1 shown in Figure 1 comprises a base material 2, an adhesive layer 3, and a decorative layer 4. The base material 2 is chemically strengthened glass or alkali-free glass. The adhesive layer 3 is formed on a part of the base material 2 so as to be in contact with the base material 2. The shape of the adhesive layer 3 is not particularly limited, but for example, in the case where the decorative layer 4 has light-shielding properties, it may be formed in a frame shape (ring-shaped, picture frame shape, etc.) along the edge of the base material 2 in order to prevent light from entering the interior. The adhesive layer 3 only needs to be formed on at least a part of the side of the base material 2 where the decorative layer 4 is located, and may be formed on the entire surface of the side of the base material 2 where the decorative layer 4 is located.

[0021] The decorative layer 4 is laminated via the adhesive layer 3. In other words, the decorative layer 4 is laminated on top of the adhesive layer 3. Preferably, the area where the decorative layer 4 is formed is the same area as the area where the adhesive layer 3 is formed, or it is inside the area where the adhesive layer 3 is formed. From the viewpoint of improving the adhesion of the decorative layer 4 to the substrate 2 and more reliably preventing the decorative layer 4 from falling off, it is preferable that the area where the decorative layer 4 is formed is inside the area where the adhesive layer 3 is formed. The shape of the decorative layer 4 is not particularly limited, but for example, if the decorative layer 4 has light-shielding properties, from the viewpoint of preventing light from entering the interior, it is formed in a frame shape (ring-shaped, picture frame-shaped, etc.) along the edge of the substrate 2.

[0022] The adhesive layer 3 contains a heat-transferable resin. Because the adhesive layer 3 contains a heat-transferable resin, the adhesive layer 3, which is made on a temporary substrate separate from the base material 2, can be formed by heating and transferring it onto the base material 2, resulting in excellent adhesion to the base material 2. The decorative layer 4 also contains a heat-transferable resin. Because the decorative layer 4 contains a heat-transferable resin, the decorative layer 4, which is made on a temporary substrate separate from the base material 2, can be formed by heating and transferring it onto the adhesive layer 3. Furthermore, because both the adhesive layer 3 and the decorative layer 4 contain a heat-transferable resin, when the adhesive layer 3 is heat-transferred onto the decorative layer 4, or when the laminate of the adhesive layer 3 and the decorative layer 4 is transferred onto the base material 2, the area near the boundary between the decorative layer 4 and the adhesive layer 3 is compatible, resulting in excellent adhesion between the adhesive layer 3 and the decorative layer 4, and consequently, excellent adhesion of the decorative layer 4 to the base material 2.

[0023] In the laminate of the present invention, the decorative layer may be a single layer or a multi-layered layer. By forming a multi-layered layer, a thicker decorative layer can be created, and if the decorative layer has light-shielding properties, the light-shielding properties can be made even higher. The laminate 1 shown in Figure 2 is the same as the laminate 1 shown in Figure 1, except that the decorative layer 4 is a multi-layered layer. When the decorative layer 4 is a multi-layered layer, the thickness and formation area of ​​the multiple decorative layers 4 may be the same or different. In the laminate 1 shown in Figure 2, the multi-layered decorative layer 4 is stepped, and the formation area of ​​the first decorative layer from the adhesive layer 3 side is larger than the formation area of ​​the second decorative layer. With such a structure, the shape of the decorative layer 4 becomes more stable.

[0024] In the laminate of the present invention, the adhesive layer only needs to be laminated on at least a part of the substrate, and may be laminated on a part as shown in Figure 1, or on the entire surface as shown in Figure 3. The laminate 1 shown in Figure 3 is the same as the laminate 1 shown in Figure 1, except that the adhesive layer 3 is formed on the entire surface of the side of the substrate 2 where the decorative layer 4 is located (one surface).

[0025] The laminate of the present invention may comprise multiple adhesive layers. For example, the laminate of the present invention comprises at least one adhesive layer on one side of the substrate (the side with the decorative layer), but may also comprise an adhesive layer on the side of the substrate opposite to the aforementioned side (the other side). The multiple adhesive layers may have the same thickness, composition, shape, or physical properties, or they may be different layers.

[0026] The laminate 1 shown in Figure 4 comprises a plurality of adhesive layers 3, with adhesive layer 31 and adhesive layer 32. In the laminate 1 shown in Figure 4, adhesive layer 31 is formed over the entire surface of one side of the base material 2, and adhesive layer 32 is also formed on the other side of the base material 2. Although adhesive layer 32 is formed over the entire surface of the other side of the base material 2, it may also be formed on a part of the other side of the base material 2. Also, in Figure 4, adhesive layer 31 may be formed on a part of one side of the base material 2.

[0027] In the laminate 1 shown in Figure 5, the adhesive layer 3 is formed over the entire surface of one side of the substrate 2 and is also formed to cover the decorative layer 4. As shown in Figure 5, the decorative layer may also be covered by the adhesive layer.

[0028] The laminate of the present invention may have an adhesive layer on one of the above-mentioned surfaces (the surface on which the adhesive layer and the decorative layer are provided). The adhesive layer is preferably formed to be in contact with at least one of the adhesive layer and the decorative layer, and is preferably formed to be in contact with at least the adhesive layer from the viewpoint of having superior adhesive properties of the adhesive layer to the substrate. In particular, it is more preferable that the adhesive layer is formed to cover both the adhesive layer and the decorative layer from the viewpoint of more reliably preventing the decorative layer from falling off. Furthermore, the adhesive layer is preferably provided on at least a part of the substrate, and may be provided on the entire surface of the substrate.

[0029] The laminate 1 shown in Figure 6 comprises an adhesive layer 5. The adhesive layer 5 is formed to cover the entire surface of one of the surfaces of the substrate 2, including the adhesive layer 3 and the decorative layer 4. The adhesive layer 5 is in contact with both the adhesive layer 3 and the decorative layer 4.

[0030] The laminate 1 shown in Figure 7 is the same as the laminate 1 shown in Figure 6, except that the adhesive layer 3 is formed over the entire surface of one of the surfaces of the base material 2. As shown in Figure 7, the adhesive layer 3 is provided over the entire surface of the base material 2, which further increases the adhesion of the adhesive layer 5 to the base material 2.

[0031] The laminate 1 shown in Figure 8 is the same as the laminate 1 shown in Figure 7, except that the adhesive layer 3 is formed over the entire surface of one side of the substrate 2 and covers the decorative layer 4. As shown in Figure 8, when the adhesive layer 3 covers the decorative layer 4, there is no area where the adhesive layer 5 and the decorative layer 4 come into contact, and the adhesion of the adhesive layer 5 to the substrate 2 becomes even higher.

[0032] The laminate of the present invention may comprise a plurality of adhesive layers. For example, the laminate of the present invention may have an adhesive layer on one side of the substrate (the side with the decorative layer), on the other side of the substrate, or on both sides. The plurality of adhesive layers may have the same thickness, composition, shape, or physical properties, or they may be different layers.

[0033] Furthermore, from the viewpoint of having superior adhesion to the substrate, it is preferable that at least a portion of the adhesive layer provided on the other surface is provided via the adhesive layer provided on the other surface.

[0034] The laminate 1 shown in Figure 9 comprises a plurality of adhesive layers 5, with adhesive layers 51 and adhesive layer 52. Adhesive layer 52 is provided via an adhesive layer 32 formed on the entire surface of the other side of the base material 2. Other aspects are the same as the laminate shown in Figure 7. In the laminate 1 shown in Figure 9, the adhesive layer 32 is formed on the entire surface of the other side of the base material 2, but it may also be formed on a part of the other side of the base material 2. Also, in Figure 9, adhesive layer 31 may be formed on a part of one side of the base material 2.

[0035] In the laminate 1 shown in Figure 10, the adhesive layer 31 is formed over the entire surface of one side of the substrate 2 and is also formed to cover the decorative layer 4. Other aspects are the same as those of the laminate 1 shown in Figure 9.

[0036] Furthermore, the laminate of the present invention may include other layers besides those described above. Examples of these other layers include a protective layer and a receiving layer, which are formed on the decorative layer. The protective layer and the receiving layer are laminated on the decorative layer in this order. If the laminate of the present invention includes an adhesive layer, the protective layer and the receiving layer are laminated between the decorative layer and the adhesive layer.

[0037] In the laminate of the present invention, the ratio of the thickness of the adhesive layer to the thickness of the decorative layer [thickness of adhesive layer:thickness of decorative layer] is preferably 1:0.01 to 1:100, more preferably 1:0.015 to 1:67, and even more preferably 1:0.02 to 1:50. When the thickness of the adhesive layer is greater than 1:100, the thickness of the adhesive layer is sufficient relative to the thickness of the decorative layer, resulting in superior adhesion of the decorative layer to the substrate. When the thickness of the decorative layer is less than 1:100, the difference in height between the adhesive layer and the decorative layer is small, resulting in a better appearance. When the thickness of the decorative layer is greater than 1:0.01, the light-shielding properties are superior if they are light-shielding. When the thickness of the adhesive layer is less than 1:0.01, the difference in height between the adhesive layer and the decorative layer is small, resulting in a better appearance. Note that when the adhesive layer and the decorative layer are each composed of multiple layers (a single layer formed by the contact of multiple layers), the above thickness is the total thickness of the multiple layers. Furthermore, the adhesive layer and decorative layer in the above ratio are layers provided on the same side of the substrate, that is, the thickness of the adhesive layer and decorative layer formed on one of the surfaces (for example, the thickness of adhesive layer 3 and decorative layer 4 in Figures 1-3). Also, the thickness of the adhesive layer in the above ratio is the thickness of the adhesive layer located between the substrate and the decorative layer, for example, if the adhesive layer covers the decorative layer as shown in Figure 5, it is the thickness of adhesive layer 3 located between substrate 2 and decorative layer 4.

[0038] In the laminate of the present invention, the ratio of the total thickness of the adhesive layer and the decorative layer to the thickness of the adhesive layer [(thickness of adhesive layer + thickness of decorative layer):thickness of adhesive layer] is preferably 1:0.5 to 1:2500, more preferably 1:1 to 1:1500, and even more preferably 1:2 to 1:1000. If the thickness of the adhesive layer is greater than 1:0.5, it can adequately follow the steps between the adhesive layer and the decorative layer. If the thickness of the adhesive layer is less than 1:2500, it can further suppress adhesive overflow from the adhesive layer and blocking between laminates. Note that if the adhesive layer, decorative layer, and adhesive layer are each composed of multiple layers (a single layer formed by the contact of multiple layers), the above thickness is the total thickness of the multiple layers. Furthermore, the adhesive layer, decorative layer, and tack layer in the above ratio are layers provided on the same side of the substrate, that is, the thickness of the adhesive layer, decorative layer, and tack layer formed on one of the above sides (for example, the thickness of adhesive layer 3, decorative layer 4, and tack layer 5 in Figures 6 and 7). Also, the thickness of the adhesive layer in the above ratio is the thickness of the adhesive layer located between the substrate and the decorative layer, for example, if the adhesive layer covers the decorative layer as shown in Figure 5, it is the thickness of the adhesive layer 31 located between the substrate 2 and the decorative layer 4.

[0039] (base material) The above-mentioned substrate is chemically strengthened glass or alkali-free glass. Furthermore, the substrate can be thin. For example, ultra-thin glass can be used.

[0040] Alkali-free glass refers to glass that contains less alkali components (e.g., alkali metal oxides such as Na2O and K2O) than conventional alkali glass. However, alkali-free glass also includes glass that contains only trace amounts of alkali components. In this specification, the alkali component (alkali metal oxide) content in alkali-free glass may be, for example, 1% by mass or less, 0.1% by mass or less, or 0.05% by mass or less, or it may be substantially free of alkali components. Here, "substantially free" means that it is not contained except for unavoidable impurities.

[0041] Chemically strengthened glass offers superior bending resistance and impact resistance compared to unstrengthened glass. Furthermore, chemically strengthened glass possesses excellent mechanical strength, allowing for the use of thinner glass.

[0042] Chemically strengthened glass is glass whose mechanical properties have been enhanced by chemical means through ion exchange near the glass surface, and it has a compressive stress layer on its surface. Chemically strengthened glass has a high potassium content on its surface, resulting in compressive stress on the surface. For example, by performing ion exchange at a temperature below the glass transition temperature, alkali metal ions with small ionic radii (e.g., lithium ions, sodium ions) on the glass surface are replaced with other alkali ions with larger ionic radii (e.g., sodium ions, potassium ions). This leaves compressive stress on the glass surface, improving the strength of the glass.

[0043] Chemically strengthened glass typically has a rectangular parallelepiped shape, or a hexahedron. Chemically strengthened glass has two faces (first and second principal faces) and four sides. Typically, chemically strengthened glass is hexahedral glass, where all faces are chemically strengthened. Hexahedral glass can be obtained, for example, by chemically strengthening a glass plate. Alternatively, chemically strengthened glass may be 2-sided glass, obtained by cutting hexahedral glass to a desired size.

[0044] Examples of glass materials that make up chemically strengthened glass include aluminosilicate glass, soda-lime glass, borosilicate glass, lead glass, alkali barium glass, and aluminoborsilicate glass.

[0045] Chemically strengthened glass has a higher potassium ion concentration on its surface than near the center in the thickness direction. Therefore, glass can be identified as chemically strengthened glass by the following method. For example, if the glass is divided into 10 sections in the thickness direction, and the potassium ion concentrations in each section are labeled d1, d2, d3, ..., d10 from the outermost surface, then the glass can be identified as chemically strengthened glass if the potassium ion concentrations satisfy both d1 > d5 and d10 > d5. The potassium concentration distribution in the thickness direction can be measured, for example, by energy-dispersive X-ray analysis (EDX). Specifically, EDX mapping can be performed on the side surface of the glass substrate in the thickness direction using Oxford Instruments' "X-MaxN" at an acceleration voltage of 10 kV to quantify the potassium concentration.

[0046] As chemically strengthened glass, ultra-thin glass can be used. Commercially available chemically strengthened glass can be used as appropriate, for example, Corning's "Gorilla Glass," and as ultra-thin glass, examples include SCHOTT's "SCHOTT UTG," Corning's "Willow Glass," and Nippon Electric Glass Co., Ltd.'s "Dinorex UTG."

[0047] The thickness of the substrate (thickness of chemically strengthened glass or alkali-free glass) is preferably 10 to 2000 μm, more preferably 15 to 1000 μm, and even more preferably 20 to 500 μm, from the viewpoint of excellent flexibility and impact resistance.

[0048] (adhesive layer) The adhesive layer described above comprises at least a heat-transferable resin. In this specification, "heat-transferable resin" is a resin that can be transferred to a substrate at a heating temperature (for example, at least one temperature between 60 and 250°C) when a single layer of resin formed using the heat-transferable resin is heated. The adhesive layer may contain only one type of heat-transferable resin, or it may contain two or more types.

[0049] The above-mentioned heat-transferable resin preferably satisfies at least one of the following conditions: (1) the ratio of the elastic modulus at a heating temperature (for example, at least one temperature between 60 and 250°C) to the elastic modulus at 25°C [elastic modulus at heating temperature / elastic modulus at 25°C] is 1 / 5 or less, or (2) the softening point is between 0 and 200°C. Note that the above-mentioned elastic modulus is the storage modulus.

[0050] The ratio of the elastic moduli is more preferably 1 / 10 or less, and even more preferably 1 / 50 or less. When the ratio of the elastic moduli is 1 / 5 or less, the adhesive layer is not sticky at room temperature and can be handled, providing excellent handling properties, and when heated, it becomes sticky and can be transferred to the substrate. The softening point can be measured by known or conventional measurement methods, such as the ring-and-ball method (JIS K7234), the mercury substitution method (JIS K7234), and the Vicat softening temperature (JIS K7206). Furthermore, the heating temperature in (1) above is preferably 80 to 200°C, and more preferably 100°C.

[0051] The above storage modulus is a value measured by dynamic viscoelasticity. The above storage modulus may be the shear storage modulus or the tensile storage modulus. However, if the adhesive layer is curable, the modulus of elasticity after curing will be high, and when measuring the shear storage modulus, slippage may occur between the adhesive layer and the measuring jig, making it impossible to perform the measurement properly. For this reason, if the shear storage modulus cannot be measured properly (for example, if the modulus of elasticity is 10 8 If it exceeds the above, the storage modulus is preferably the tensile storage modulus. The storage modulus can be controlled by the type of base polymer constituting the heat transferable resin, the monomer composition, the weight-average molecular weight, the amount of crosslinking agent used (amount added), and the type and content of other additives. If the adhesive layer is curable, the elastic modulus of the adhesive layer in the above ratio may be the elastic modulus of the adhesive layer before curing or the elastic modulus of the adhesive layer after curing, but it is preferably the elastic modulus before heat transfer.

[0052] The above softening point is more preferably 20 to 200°C, and even more preferably 40 to 200°C. If the above softening point is 0°C or higher, the adhesive layer is not sticky at room temperature and can be handled, resulting in excellent handling properties. If the above softening point is 200°C or lower, stickiness can be generated by heating with low energy, allowing for energy-saving transfer to the substrate. If the above adhesive layer is curable, the above softening point of the adhesive layer may be the softening point of the adhesive layer before curing, or the softening point of the adhesive layer after curing. Furthermore, it is preferable that the above softening point is the softening point before heat transfer.

[0053] Examples of the above-mentioned heat-transferable resins include various polymers that exhibit rubber elasticity at room temperature, such as epoxy polymers, acrylic polymers, rubber polymers (natural rubber, synthetic rubber, mixtures thereof, etc.), polyester polymers, urethane polymers, polyether polymers, silicone polymers, polyamide polymers, and fluorine polymers. Only one of these heat-transferable resins may be used, or two or more may be used. In this specification, the above-mentioned polymers refer to those having monomer-derived structural units, and their weight-average molecular weight and number-average molecular weight are not particularly limited. For example, compounds with a weight-average molecular weight or number-average molecular weight of about 1000 are also included in the above-mentioned polymers.

[0054] The glass transition temperature (Tg) of the above-mentioned heat-transferable resin is preferably less than 200°C, more preferably 150°C or lower, and even more preferably 125°C or lower. The glass transition temperature is preferably, for example, -80°C or higher, more preferably -40°C or higher, and even more preferably -20°C or higher. Furthermore, the glass transition temperature of the above-mentioned adhesive layer is preferably within the above range.

[0055] For the glass transition temperature (Tg) of a heat transfer resin, the theoretical glass transition temperature (Tg) can be obtained based on Fox's equation, as shown below. Fox's equation is a relationship between the glass transition temperature Tg of a polymer and the glass transition temperature Tgi of the homopolymer of the monomers constituting the polymer. In Fox's equation below, Tg represents the glass transition temperature (°C) of the polymer, Wi represents the weight fraction of monomer i constituting the polymer, and Tgi represents the glass transition temperature (°C) of the homopolymer formed from monomer i. For the glass transition temperature of the homopolymer, literature values ​​can be used. For example, "Polymer Handbook" (4th edition, John Wiley & Sons, Inc., 1999) lists the glass transition temperatures of various homopolymers. On the other hand, the glass transition temperature of the monomer homopolymer can also be determined by the method specifically described in Japanese Patent Publication No. 2007-51271. Fox's formula 1 / (273+Tg)=Σ[Wi / (273+Tgi)]

[0056] The adhesive layer preferably contains the heat-transferable resin as a base polymer. The content of the base polymer in the adhesive layer is not particularly limited, but is preferably 75% by mass or more (for example, 75 to 99.9% by mass) and more preferably 85% by mass or more (for example, 85 to 99.9% by mass) based on the total amount (100% by mass) of the adhesive layer.

[0057] The adhesive layer described above preferably has curability. Examples of curability include active energy ray curability, thermosetting, and moisture curability. Examples of active energy rays include ionizing radiation such as alpha rays, beta rays, gamma rays, neutron rays, and electron beams, as well as ultraviolet rays.

[0058] The adhesive layer may contain a curable resin. Examples of curable resins include active energy ray curable resins, thermosetting resins, and moisture-curable resins. The adhesive layer may contain only one type of curable resin, or two or more types. The heat transfer resin may also be curable. That is, the heat transfer resin may be a curable resin. A heat transfer resin with curability may be included in the content of either the heat transfer resin or the thermopolymer resin.

[0059] As the thermosetting resin mentioned above, known or conventional thermosetting resins can be used, for example, resins having thermosetting functional groups. Examples of the thermosetting functional groups include epoxy group-containing groups such as glycidyl groups, carboxyl groups, hydroxyl groups, isocyanate groups, and aziridyl groups. The thermosetting functional group may be one type or two or more types.

[0060] Examples of the thermosetting resins mentioned above include epoxy resins, phenolic resins, urea resins, melamine resins, unsaturated polyester resins, bismaleimide resins, polyurethane resins, diallyl phthalate resins, silicone resins, polyimide resins, polyamideimide resins, and benzocyclobutene resins.

[0061] As the active energy ray curable resin mentioned above, known or conventional active energy ray curable resins can be used, for example, resins having active energy ray curable functional groups. Examples of the active energy ray curable functional groups include epoxy group-containing groups such as glycidyl groups, and ethylenically unsaturated groups such as allyl groups, acryloyl groups, and methacryloyl groups. The active energy ray curable functional group may be one type or two or more types.

[0062] Examples of the above-mentioned active energy ray curable resins include resins having two or more of the above-mentioned active energy ray curable functional groups in one molecule, such as epoxy resins, polyester acrylic resins, polyether acrylic resins, urethane acrylic resins, carbonate acrylic resins, epoxy acrylic resins, and other acrylic resins.

[0063] The adhesive layer described above may contain other components besides those listed above, as long as they do not impair the effects of the present invention. Examples of these other components include crosslinking agents, curing agents, curing catalysts, crosslinking accelerators, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, fillers (metal powders, organic fillers, inorganic fillers, etc.), colorants (pigments, dyes, etc.), antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, UV absorbers, polymerization inhibitors, rust inhibitors, granular materials, foil-like materials, flame retardants, silane coupling agents, ion trapping agents, photoacid generators, thermal polymerization initiators, and photopolymerization initiators (photoradical generators, photoinitiators). Each of these other components may be used individually or in combination of two or more.

[0064] The thickness of the adhesive layer is preferably 0.01 to 50 μm, more preferably 0.05 to 35 μm, and even more preferably 0.1 to 20 μm. When the thickness of the adhesive layer is 0.01 μm or more, the adhesion of the decorative layer to the substrate is superior. When the thickness of the adhesive layer is 50 μm or less, the difference in height between the adhesive layer and the decorative layer is small, resulting in a good appearance. If the adhesive layer is composed of multiple layers (a single layer formed by the contact of multiple layers), the above thickness is the total thickness of the multiple layers. Furthermore, the thickness of the adhesive layer is the thickness of the adhesive layer located between the substrate and the decorative layer. For example, as shown in Figure 5, if the adhesive layer covers the decorative layer, it is the thickness of the adhesive layer 31 located between the substrate 2 and the decorative layer 4.

[0065] The elastic modulus of the above adhesive layer at 25°C is 10 4 ~10 10 Pa is preferred, and more preferably 3 × 10 4 ~1 × 109 Pa, more preferably 5×10 4 ~5×10 8 Pa. When the elastic modulus of the adhesive layer at 25°C is 10 4 Pa or more, it has appropriate cohesive force and excellent adhesion to the adhesive layer and the substrate. When the elastic modulus of the adhesive layer at 25°C is 10 10 Pa or less, appropriate flexibility and flex resistance can be maintained. When the adhesive layer has curability, the elastic modulus may be the elastic modulus of the adhesive layer before curing or the elastic modulus of the adhesive layer after curing, but it is preferably the elastic modulus of the adhesive layer before curing.

[0066] When the adhesive layer has a glass transition temperature (Tg), the elastic modulus at (Tg + 20)°C is 10 3 ~10 7 Pa is preferable, more preferably 3×10 3 ~5×10 6 Pa, more preferably 5×10 3 ~1×10 6 Pa. When the elastic modulus of the adhesive layer at (Tg + 20)°C is 10 3 Pa or more, it has appropriate cohesive force and excellent adhesion to the adhesive layer and the substrate. When the elastic modulus of the adhesive layer at (Tg + 20)°C is 10 7 Pa or less, appropriate flexibility and flex resistance can be maintained. When the adhesive layer has curability, the elastic modulus may be the elastic modulus of the adhesive layer before curing or the elastic modulus of the adhesive layer after curing, but it is preferably the elastic modulus of the adhesive layer before curing.

[0067] Also, when the adhesive layer has curability, the elastic modulus of the adhesive layer after curing at 25°C is 10 6 ~10 10 Pa is preferable, more preferably 5×10 6 ~5×10 9 Pa, more preferably 1×10 7 ~1×10 9 Pa. When the elastic modulus of the adhesive layer after curing at 25°C is 10 6If the elastic modulus of the cured adhesive layer is Pa or higher, the adhesion to the adhesive layer and substrate is superior. 10 If the elastic modulus is below Pa, it is possible to maintain appropriate flexibility and bending resistance. Furthermore, it is preferable that the elastic modulus of the cured adhesive layer at 60°C is within the above range, the elastic modulus of the cured adhesive layer at 80°C is within the above range, and the elastic modulus of the cured adhesive layer at 100°C is within the above range. If the adhesive layer is curable, if the elastic modulus after curing is within the above range, it is possible to maintain a high elastic modulus even at high temperatures, resulting in superior adhesive reliability.

[0068] (Decorative layer) The decorative layer described above contains at least one heat-transferable resin. The decorative layer may contain only one type of heat-transferable resin, or it may contain two or more types.

[0069] Examples of the heat-transferable resin in the decorative layer include those exemplified and described as the heat-transferable resin contained in the adhesive layer described above. The preferred embodiment of the heat-transferable resin in the decorative layer is the same as the preferred embodiment of the heat-transferable resin in the adhesive layer.

[0070] The heat-transferable resin in the decorative layer may be the same type as the heat-transferable resin contained in the adhesive layer (for example, acrylic polymer and acrylic polymer), or it may be a different type (for example, acrylic polymer and rubber polymer). If they are the same type, when the adhesive layer is heat-transferred onto the decorative layer, the area near the boundary between the decorative layer and the adhesive layer becomes compatible, resulting in excellent adhesion between the adhesive layer and the decorative layer, and consequently, excellent adhesion of the decorative layer to the substrate.

[0071] The decorative layer preferably contains the heat-transferable resin as a base polymer. The content of the base polymer in the decorative layer is not particularly limited, but is preferably 10% by mass or more (for example, 10 to 99.9% by mass) and more preferably 25% by mass or more (for example, 25 to 99.9% by mass) based on the total amount (100% by mass) of the decorative layer.

[0072] The decorative layer may contain a coloring agent. The coloring agent may be a dye or a pigment, as long as it is soluble or dispersible in the decorative layer. Pigments are preferred from the viewpoint of superior weather resistance and durability. One coloring agent may be used alone, or two or more may be used.

[0073] Examples of the above-mentioned colorants include black colorants, cyan colorants, magenta colorants, and yellow colorants. The above-mentioned colorants may be present in a single form or in a form containing two or more types.

[0074] Examples of black colorants include carbon black, carbon nanotubes, graphite, copper oxide, manganese dioxide, azo pigments such as azomethine azoblack, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite, magnetite, chromium oxide, iron oxide, molybdenum disulfide, complex oxide black pigments, anthraquinone-based organic black dyes, and azo-based organic black dyes. Examples of carbon black include furnace black, channel black, acetylene black, thermal black, and lamp black. Examples of black colorants include CI Solvent Black 3, 7, 22, 27, 29, 34, 43, and 70; CI Direct Black 17, 19, 22, 32, 38, 51, and 71; CI Acid Black 1, 2, 24, 26, 31, 48, 52, 107, 109, 110, 119, and 154; CI Disperse Black 1, 3, 10, and 24; and CI Pigment Black 1 and 7.

[0075] Examples of cyan-based colorants include CI Solvent Blue 25, 36, 60, 70, 93, 95; CI Acid Blue 6, 45; CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:5, 15:6, 16, 17, 17:1, 18, 22, 25, 56, 60, 63, 65, 66; CI Bat Blue 4, 60, and CI Pigment Green 7.

[0076] Examples of magenta-based colorants include CI Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, 122; CI Disperse Red 9; CI Solvent Violet 8, 13, 14, 21, 27; CI Disperse Examples include Violet 1; CI Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; CI Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28, etc. Furthermore, as magenta-based colorants, for example, CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 42, 48:1, Same 48:2, same 48:3, same 48:4, same 49, same 49:1, same 50, same 51, same 52, same 52:2, same 53:1, same 54, same 55, same 56, same 57:1, same 58, same 60, same 60:1, same 63, same 63:1, same 63:2, same 64, same 64:1, same 67, same 68, same 81, same 83, same 87, same 88, same 89, same 90, same 92, same 101 , 104, 105, 106, 108, 112, 114, 122, 123, 139, 144, 146, 147, 149, 150, 151, 163, 166, 168, 170, 171, 172, 175, 176, 177, 178, 179, 184, 185, 187, 190 Examples include 193, 202, 206, 207, 209, 219, 222, 224, 238, and 245; CI Pigment Violet 3, 9, 19, 23, 31, 32, 33, 36, 38, 43, and 50; CI Bat Red 1, 2, 10, 13, 15, 23, 29, and 35.

[0077] Examples of yellow colorants include CI Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162; CI Pigment Orange 31, 43; CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 24, 34, 35, 37, 42, 53, 55, 65, 73, 74. Examples include 75, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 108, 109, 110, 113, 114, 116, 117, 120, 128, 129, 133, 138, 139, 147, 150, 151, 153, 154, 155, 156, 167, 172, 173, 180, 185, 195; CI Bat Yellow 1, 3, 20, etc.

[0078] As the above-mentioned coloring agent, from the viewpoint of excellent light-shielding properties of the decorative layer, a coloring agent that produces black is preferred, that is, it is preferable to include a coloring agent so that the decorative layer produces black. As the above-mentioned coloring agent that produces black, a black-based coloring agent may be used, which is a combination of the above-mentioned black-based coloring agent or a coloring agent that produces a color other than black and functions as a black-based coloring agent.

[0079] The decorative layer described above may contain other components besides those listed above, as long as they do not impair the effects of the present invention. Examples of these other components include crosslinking agents, curing agents, curing catalysts, crosslinking accelerators, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, fillers (metal powders, organic fillers, inorganic fillers, etc.), antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, rust inhibitors, granular materials, foil-like materials, flame retardants, silane coupling agents, and ion trapping agents. Each of these other components may be used individually or in combination of two or more.

[0080] The thickness of the decorative layer is preferably 0.01 to 50 μm, more preferably 0.05 to 35 μm, and even more preferably 0.1 to 20 μm. If the thickness of the decorative layer is 0.01 μm or more, the light-shielding properties are superior when light-shielding properties are present. If the thickness of the decorative layer is 50 μm or less, the difference in height between the adhesive layer and the decorative layer is small, resulting in a good appearance. If the decorative layer is composed of multiple layers (a single layer formed by the contact of multiple layers), the above thickness is the total thickness of the multiple layers.

[0081] (Adhesive layer) The adhesive layer can be a known or conventional adhesive layer. Preferably, the adhesive layer is a solvent-free adhesive layer containing a photopolymerized polymer as the base polymer. Such an adhesive layer can be manufactured from a solvent-free adhesive composition. When manufacturing the adhesive layer from a solvent-free adhesive composition, there is no need to remove the solvent by volatilizing it from the coating film of the composition. Therefore, a laminate comprising the adhesive layer is suitable for reducing environmental impact.

[0082] The adhesive layer is preferably a sheet-like pressure-sensitive adhesive (solvent-free adhesive sheet) formed from a solvent-free adhesive composition. Therefore, the adhesive layer (solvent-free adhesive composition) preferably contains at least a photopolymerizable polymer as a base polymer. A photopolymerizable polymer is a polymer formed by a polymerization method in which the polymerization reaction of polymerizable components is advanced by irradiation with active energy rays such as ultraviolet light.

[0083] The base polymer is an adhesive component that exhibits tackiness in the adhesive layer described above. The base polymer is not particularly limited, but examples include acrylic polymers, rubber polymers (such as natural rubber polymers and synthetic rubber polymers), silicone polymers, polyester polymers, urethane polymers, polyamide polymers, epoxy polymers, vinyl alkyl ether polymers, and fluorine polymers. One type of base polymer may be used, or two or more types may be used.

[0084] The content of the base polymer in the adhesive layer is not particularly limited, but is preferably 75% by mass or more (for example, 75 to 99.9% by mass) and more preferably 85% by mass or more (for example, 85 to 99.9% by mass) based on the total amount (100% by mass) of the adhesive layer.

[0085] The adhesive layer described above may contain other components besides those listed above, as long as they do not impair the effects of the present invention. Examples of these other components include crosslinking agents, curing agents, curing catalysts, crosslinking accelerators, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, fillers (metal powders, organic fillers, inorganic fillers, etc.), colorants (pigments, dyes, etc.), antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, rust inhibitors, granular materials, foil-like materials, flame retardants, silane coupling agents, and ion trapping agents. Each of these other components may be used individually or in combination of two or more.

[0086] The thickness of the adhesive layer is preferably 5 to 2500 μm, more preferably 10 to 1000 μm, and even more preferably 15 to 500 μm. When the thickness of the adhesive layer is 5 μm or more, the adhesion to the substrate and the decorative layer is superior. When the thickness of the adhesive layer is 2500 μm or less, when the substrate is bent, the formation of creases due to deformation of the adhesive layer is less likely to occur. If the adhesive layer is composed of multiple layers (a single layer formed by the contact of multiple layers), the above thickness is the total thickness of the multiple layers.

[0087] The elastic modulus of the above adhesive layer at 25°C is 10 3 ~10 6 Pa is preferred, futur2×10 3 ~5×10 5 Pa, more preferably 5 × 10 3 ~10 5 The elastic modulus of the above adhesive layer at 25°C is 10 3If the elastic modulus of the above adhesive layer is Pa or higher, it has appropriate cohesive force and superior adhesion to the adhesive layer. 6 If the elastic modulus is Pa or less, it provides superior flexibility and bending resistance. If the adhesive layer is curable, the elastic modulus may be the elastic modulus of the adhesive layer before curing, or the elastic modulus of the adhesive layer after curing.

[0088] The elastic modulus of the above adhesive layer at -20°C is 10 3 ~10 9 Pa is preferred, futur2×10 3 ~5×10 7 Pa, more preferably 5 × 10 3 ~10 6 The elastic modulus of the above adhesive layer at -20°C is 10 3 If the elastic modulus of the above adhesive layer is Pa or higher, it has appropriate cohesive force and superior adhesion to the adhesive layer. 9 If the elastic modulus is Pa or less, it provides superior flexibility and bending resistance. If the adhesive layer is curable, the elastic modulus may be the elastic modulus of the adhesive layer before curing, or the elastic modulus of the adhesive layer after curing.

[0089] The elastic modulus of the above adhesive layer at 60°C is 5 × 10 2 ~10 6 Pa is preferred, and more preferably 10 3 ~5×10 5 Pa, more preferably 2 × 10 3 ~10 5 The elastic modulus of the above adhesive layer at 60°C is 5 × 10⁻⁶. 2 If the elastic modulus of the adhesive layer is Pa or higher, it has appropriate cohesive force and superior adhesion to the adhesive layer. 6 If the elastic modulus is Pa or less, it provides superior flexibility and bending resistance. If the adhesive layer is curable, the elastic modulus may be the elastic modulus of the adhesive layer before curing, or the elastic modulus of the adhesive layer after curing.

[0090] The above modulus of elasticity is the storage modulus, and is a value measured by dynamic viscoelasticity. The above storage modulus may be the shear storage modulus or the tensile storage modulus, but it is preferably the shear storage modulus. The above storage modulus can be controlled by the type of base polymer constituting the adhesive layer, the monomer composition, the weight-average molecular weight, the amount of crosslinking agent used (amount added), and the type and content of other additives.

[0091] The adhesive layer described above may or may not have curability, but it is preferable that it does not. Examples of curability include active energy ray curability, thermosetting, and moisture curability. Examples of active energy rays include ionizing radiation such as alpha rays, beta rays, gamma rays, neutron rays, and electron beams, as well as ultraviolet rays.

[0092] (Laminated structure) The laminate of the present invention may include layers other than those described above. It is preferable that the substrate and the adhesive layer are in contact in at least a portion of the surface (preferably the entire surface of one side of the substrate). Furthermore, it is preferable that the adhesive layer and the decorative layer are in contact in at least a portion of the surface (preferably the entire surface of one side of the decorative layer).

[0093] The haze value (H) of the region of the laminate of the present invention in which the decorative layer is not laminated is not particularly limited, but from the viewpoint of efficiently reducing color shift and interference unevenness of the OLED display device, it is preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less. Furthermore, although the above haze value is not particularly limited, it may be, for example, 0.01% or more, or 0.05% or more. It is preferable that the haze value in the region of the laminate in which the decorative layer is not laminated, which includes chemically strengthened glass or alkali-free glass as a substrate, and in which one end face (for example, the end face of the one surface) is an adhesive layer or tack layer provided on one surface of the substrate, and the other end face (for example, the end face of the other surface) is the substrate, or an adhesive layer or tack layer provided on the other surface of the substrate, is within the above range.

[0094] The total light transmittance of the laminate of the present invention in the region where the decorative layer is laminated is preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less, from the viewpoint of ensuring concealment by the decorative layer. Furthermore, the above total light transmittance is not particularly limited, but may be, for example, 0.00001% or more, or 0.0001% or more. It is preferable that the total light transmittance of a laminate containing chemically strengthened glass or alkali-free glass as a base material, wherein one end face (for example, the end face of the one surface) is a decorative layer, adhesive layer, or tack layer provided on one surface of the base material, and the other end face (for example, the end face of the other surface) is the base material, or an adhesive layer or tack layer provided on the other surface of the base material, is within the above range.

[0095] The total light transmittance of the laminate of the present invention in the region where no decorative layer is laminated is not particularly limited, but from the viewpoint of ensuring the brightness of the OLED display device, it is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, and particularly preferably 90% or more. Furthermore, although the above total light transmittance is not particularly limited, it may be less than 100%, 99.9% or less, or 99% or less. It is preferable that the total light transmittance of the laminate, which includes chemically strengthened glass or alkali-free glass as a substrate, has one end face (for example, the end face of the one surface) as an adhesive layer or tack layer provided on one surface of the substrate, and the other end face (for example, the end face of the other surface) as the substrate, or an adhesive layer or tack layer provided on the other surface of the substrate, be within the above range.

[0096] The haze value and total light transmittance of the laminate of the present invention can be measured by the methods specified in JIS K7136 and JIS K7361, respectively, and can be controlled by the type and thickness of each layer constituting the laminate.

[0097] When the laminate of the present invention has the adhesive layer, the 180° peel force of the adhesive layer from the substrate (the surface on which the adhesive layer is formed), measured under conditions of a tensile speed of 300 mm / min and a peel angle of 180 degrees, is preferably 9.0 N / 25 mm or more, more preferably 9.5 N / 25 mm or more, and even more preferably 10.0 N / 25 mm or more. The higher the 180° peel force, the higher the adhesion of the adhesive layer to the substrate, and although not particularly limited, it is, for example, 50 N / 25 mm or less. When the adhesive layer and / or the adhesive layer is curable, the 180° peel force may be a value before curing or after curing for one or more of the adhesive layer and the adhesive layer.

[0098] When the laminate of the present invention has the adhesive layer described above, it is preferable that the elastic modulus of the adhesive layer at 25°C is smaller than the elastic modulus of the adhesive layer at 25°C. In other words, it is preferable that the elastic modulus of the adhesive layer at 25°C is larger than the elastic modulus of the adhesive layer at 25°C. When an adhesive layer and an adhesive layer with different elastic moduli are in close contact in this way, the adhesive layer with the lower elastic modulus can flexibly follow bending and folding movements, and the adhesive layer with the higher elastic modulus can adhere strongly to chemically strengthened glass and alkali-free glass, thus achieving both excellent flexibility and excellent adhesion to chemically strengthened glass and alkali-free glass.

[0099] When the laminate of the present invention has the adhesive layer, the ratio of the elastic modulus of the adhesive layer at 25°C to the elastic modulus of the adhesive layer at 25°C [elastic modulus of the adhesive layer at 25°C / elastic modulus of the adhesive layer at 25°C] is preferably 2 or more, more preferably 5 or more, even more preferably 10 or more, and particularly preferably 25 or more. 2 It may be more than 10 3 or more, or 10 4 It may be greater than or equal to 2. When the above ratio is 2 or greater, it is superior in achieving both adhesion to chemically strengthened glass and alkali-free glass and flexibility. Also, the above ratio may be 10 7 The following is also acceptable, 10 6The following may also apply. If the adhesive layer is curable, the elastic modulus may be the elastic modulus of the adhesive layer before curing or the elastic modulus of the adhesive layer after curing. Also, if the adhesive layer is curable, the elastic modulus may be the elastic modulus of the adhesive layer before curing or the elastic modulus of the adhesive layer after curing, but it is preferable that it is the elastic modulus of the adhesive layer after curing. That is, if the adhesive layer is curable, it is preferable that the elastic modulus of the adhesive layer at 25°C is smaller than the elastic modulus of the adhesive layer at 25°C after curing. Furthermore, if the adhesive layer is curable, it is preferable that the elastic modulus of the adhesive layer at 25°C in the above ratio is the elastic modulus of the adhesive layer at 25°C after curing.

[0100] When the laminate of the present invention has the adhesive layer described above, the peel force between the adhering adhesive layer and the adhesive layer in a T-type peel test under the conditions of 23°C and a peeling speed of 300 mm / min may be greater than 0.25 N / 25 mm, greater than 0.5 N / 25 mm, or greater than 1.0 N / 25 mm. Furthermore, the adhesive layer (or the adhesive layer) may be so adhered to the adhesive layer (or adhesive layer) that it cannot be peeled off. When the adhesive layer is curable, the adhesive layer in the peel force described above may be the adhesive layer before curing or the adhesive layer after curing. Also, when the adhesive layer is curable, the adhesive layer in the peel force described above may be the adhesive layer before curing or the adhesive layer after curing, but it is preferable that it be the adhesive layer after curing.

[0101] (compatible layer) When the laminate of the present invention has the adhesive layer described above, it is preferable that the laminate of the present invention has a compatible layer at the interface between the adhesive layer and the bonding layer. The compatible layer is a layer formed by compatibility near the boundary between the adhesive layer and the bonding layer. The mechanism by which the compatible layer is formed is not particularly limited, but for example, when the adhesive layer and the bonding layer are bonded together by lamination or the like, at least a part of the bonding layer mixes with at least a part of the adhesive layer to form the compatible layer. Because the adhesion between the adhesive layer and the bonding layer is improved by the formation of the compatible layer, peeling that may occur between the adhesive layer and the bonding layer when bending and folding operations are repeated is suppressed, and as a result the occurrence of peeling and creases (crazing) is further suppressed.

[0102] The thickness of the compatible layer is preferably 10 nm to 20 μm, more preferably 20 nm to 10 μm, and even more preferably 30 nm to 5 μm. When the thickness of the compatible layer is 10 nm or more, the adhesion between the adhesive layer and the tack layer is improved. When the thickness of the compatible layer is 20 μm or less, the influence on the elastic modulus of the tack layer can be further suppressed, resulting in improved flexibility and bending resistance.

[0103] The thickness ratio R of the compatible layer, defined by the following formula (1), is not particularly limited, but is preferably 0.01 to 0.99, more preferably 0.02 to 0.95, and even more preferably 0.05 to 0.9. When R is 0.01 or higher, the adhesion between the adhesive layer and the tack layer is superior. When R is 0.99 or lower, the influence on the elastic modulus of the tack layer can be further suppressed, resulting in superior flexibility and bending resistance. The compatible layer can be confirmed, for example, by observing the cross-section of an optical element using spectroscopic analysis such as infrared absorption spectroscopy (IR method) or by observation with a transmission electron microscope (TEM), and its thickness can be measured.

[0104] R = [DC / (DC + DB)] (1)

[0105] In the above formula (1), DB is the thickness of the adhesive layer and DC is the thickness of the compatible layer.

[0106] The laminate of the present invention may have a release liner bonded to at least one surface (the surface of the adhesive layer, decorative layer, or tack layer) until use. When both sides of the laminate of the present invention are protected with a release liner, each side may be protected by two release liners, or it may be protected by a single release liner with both sides being release surfaces, wound in a roll shape (winding body). The release liner is used as a protective material for the laminate and is peeled off when it is attached to the substrate. Note that the release liner is not necessarily required.

[0107] The above-mentioned release liner can be conventional release paper or the like, and is not particularly limited, but examples include a substrate having a release treatment layer, a low-adhesion substrate made of a fluoropolymer, or a low-adhesion substrate made of a nonpolar polymer. Examples of the substrate having the release treatment layer include plastic films and paper surface-treated with release agents such as silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide. Examples of fluorine-based polymers in the low-adhesion substrate made of a fluoropolymer include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and chlorofluoroethylene-vinylidene fluoride copolymer. Examples of the above-mentioned nonpolar polymer include olefin resins (e.g., polyethylene, polypropylene, etc.). The release liner can be formed by known or conventional methods. The thickness of the release liner is also not particularly limited.

[0108] The applications of the laminate of the present invention are not particularly limited and can be used for any application. Preferably, the laminate of the present invention is a laminate that can be used for optical applications, that is, for lamination on optical members (optical laminate). Examples of the optical members include electrical and electronic equipment. Note that "electrical and electronic equipment" refers to equipment that falls under at least one of electrical equipment or electronic equipment. Examples of the electrical and electronic equipment include image display devices such as liquid crystal displays, electroluminescent displays, and plasma displays, and portable electronic devices. Examples of the image display devices include image display devices in portable electronic devices, and displays (roll displays) inside and outside vehicles such as trains and buses.

[0109] Examples of the above-mentioned image display devices include liquid crystal displays, organic / inorganic electroluminescent displays, plasma displays, and OLED display panels. Examples of the above-mentioned image display devices include image display devices in portable electronic devices, in-vehicle displays, and digital signage (electronic billboards). The above-mentioned image display devices may be in a form (structure) such as a so-called "flexible type," or they may be in a form (structure) that can be bent or folded, such as a so-called "foldable type" or "rollable type."

[0110] Examples of the above-mentioned portable electronic devices include mobile phones, smartphones, tablet computers, notebook computers, various wearable devices (for example, wristwear-type devices worn on the wrist like watches, modular devices attached to a part of the body with clips or straps, eyewear-type devices including glasses (monocular and binocular types, including head-mounted types), clothing-type devices attached to shirts, socks, hats, etc. as accessories, earwear-type devices attached to the ears like earphones, etc.), digital cameras, digital video cameras, audio equipment (portable music players, IC recorders, etc.), calculators (calculators, etc.), portable game consoles, electronic dictionaries, electronic organizers, e-books, in-car information systems, portable radios, portable televisions, portable printers, portable scanners, and portable modems. In this specification, "portable" means not merely being able to carry something, but having a level of portability that allows an individual (a typical adult) to carry it relatively easily.

[0111] The optical components mentioned above specifically include, for example, components and modules that make up portable electronic devices, and housings for components and modules that make up portable electronic devices. More specifically, they include cover glass, lenses (especially glass lenses), touch panels, touch sensors such as touch sensor films (especially touch sensor films with metal wiring such as metal mesh films and silver nanowire films), polarizing films, display panels, sheet keyboards, protective panels for information display sections, housings, and decorative sheets. In this specification, a display panel refers to a structure that consists of at least a lens (especially a glass lens) and a touch panel. Furthermore, the term "lens" in this specification is a concept that includes both transparent materials that exhibit light refraction and transparent materials that do not exhibit light refraction. In other words, the term "lens" in this specification also includes simple window panels that do not exhibit light refraction.

[0112] The laminate of the present invention comprises a thin, chemically strengthened glass or alkali-free glass with excellent flexibility and impact resistance as a base material. Therefore, the laminate of the present invention is preferably used for lamination to components in electrical and electronic equipment that is used in a bendable manner, such as a bendable substrate, such as a bendable image display device (flexible display) (especially a foldable image display device (foldable display)).

[0113] The laminate of the present invention is preferably used by being laminated onto an OLED display panel. The OLED display panel comprises at least an OLED element in which an anode, an OLED layer including an emissive layer, and a cathode are laminated in that order. The laminate of the present invention is laminated on the viewing side of the OLED element in the OLED display panel. An OLED display device in which the laminate of the present invention and the OLED display panel are laminated may be referred to as "the OLED display device of the present invention".

[0114] The laminate of the present invention is preferably a laminate used in an OLED display device in which only optical elements with a polarization degree of 95% or less are laminated on the viewing side of the OLED element (laminated for OLED display device). That is, the OLED display device of the present invention preferably has an OLED display panel in which only optical elements with a polarization degree of 95% or less are laminated on the viewing side of the OLED element. "Only optical elements with a polarization degree of 95% or less are laminated on the viewing side of the OLED element" means that the optical elements on the viewing side of the OLED element do not include optical elements with a polarization degree exceeding 95%. "Optical elements with a polarization degree exceeding 95%" are not particularly limited, but include polarizers such as linear polarizers, quarter phase difference plates, half phase difference plates, circular polarizers, and reflective polarizers. That is, the OLED display device of the present invention is preferably an OLED display device that does not include polarizers on the viewing side of the OLED element.

[0115] The degree of polarization is determined by the following formula, based on the parallel transmittance Tp and orthogonal transmittance Tc, which are measured using a UV-Vis spectrophotometer and corrected for luminous sensitivity. Polarization degree (%)={(Tp-Tc) / (Tp+Tc)}1 / 2×100

[0116] The OLED display device of the present invention, by not including a polarizing plate on the viewing side of the OLED element, suppresses the absorption of light emitted from the OLED element by the polarizing plate, improving light collection efficiency, saving power consumption, and extending the lifespan of the OLED element. Furthermore, the absence of a polarizing plate allows for a thinner design and reduces manufacturing costs.

[0117] [Method for manufacturing the laminated material of the present invention] The laminate of the present invention can be manufactured by (i) forming a laminate of an adhesive layer and a decorative layer on a temporary substrate and transferring the laminate to one surface of the substrate, and (ii) sequentially transferring the adhesive layer and the decorative layer to one surface of the substrate.

[0118] The manufacturing method described in (i) above comprises, for example, at least a step of heating a decorative layer formed on a film substrate (a) and transferring it to one side of a temporary substrate (decorative layer transfer step), and a step of heating an adhesive layer formed on a film substrate (b) and transferring it onto the decorative layer (adhesive layer transfer step). Preferably, the manufacturing method described in (i) above comprises, after the adhesive layer transfer step, a step of transferring the laminate of the decorative layer and the adhesive layer on the temporary substrate to the substrate (laminated laminate transfer step).

[0119] Regarding the manufacturing method described in (i) above, a method for manufacturing the laminate 1 shown in Figure 1 will be specifically explained using Figures 11 to 13. Note that the manufacturing method shown in Figures 11 to 13 is a preferred embodiment, and the manufacturing method for the laminate of the present invention is not limited to the above method.

[0120] (Decorative layer transfer process) In the decorative layer transfer process described above, as shown in Figure 11, the decorative layer 4 formed on the entire surface of the film substrate (a) 6 is heated to transfer the decorative layer to one side of the temporary substrate 7. Note that the decorative layer 4 does not necessarily have to be formed on the entire surface of the film substrate (a) 6, but may be formed on only a portion of the surface, including the area to be transferred.

[0121] The film substrate (a) can be any material from which the decorative layer can be peeled off by heating, such as a plastic film. Examples of plastics that make up the plastic film include polyester resins such as polyethylene terephthalate (PET), acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate, triacetylcellulose (TAC), polysulfone, polyarylate, polyimide, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, and ethylene-propylene copolymer. One or more of these plastic materials may be used. Furthermore, since the film substrate (a) is heated in the decorative layer transfer process, it is preferable that it has heat resistance at the heating temperature during transfer, for example, that it does not deform and / or shrink.

[0122] The decorative layer described above can be formed on a film substrate (a) by known or conventional methods. For example, the decorative layer can be produced by coating a composition for forming the decorative layer onto a film substrate (a) and drying and curing the resulting composition layer, or by coating the composition onto a release liner, curing the resulting composition layer by irradiating it with active energy rays, and then transferring it onto a film substrate (a). If necessary, it may also be further heated and dried.

[0123] A known coating method may be used for applying (coating) the above composition. For example, coaters such as gravure roll coaters, reverse roll coaters, kiss roll coaters, dip roll coaters, bar coaters, knife coaters, spray coaters, comma coaters, and direct coaters may be used.

[0124] In the decorative layer transfer process described above, first, the decorative layer 4 formed on the film substrate (a) 6 is placed facing the temporary substrate 7 (Figure 11(a)). Next, the decorative layer 4 is brought into contact with one side of the temporary substrate 7 (Figure 11(b)), and heating can be performed from the side of the film substrate (a) 6 that does not have the decorative layer 4. Heating is performed selectively, selecting only the area of ​​the decorative layer 4 to be transferred. Heating can be performed using a known heating jig 8. In Figure 11(b), the decorative layer that has been heated selectively is indicated by 4a. The temperature during heating is appropriately selected depending on the type of decorative layer, for example, 60 to 250°C, or 80 to 200°C. After heating, the film substrate (a) 6 is peeled off from the temporary substrate 7, the selectively heated decorative layer 4 is transferred to the temporary substrate 7, and the unheated decorative layer 4 is peeled off from the temporary substrate 7 together with the film substrate (a) 6 (Figure 11(c)).

[0125] As the temporary substrate mentioned above, the film substrate (a) described above can be used. Furthermore, since the temporary substrate is heated in the laminate transfer process, it is preferable that it has heat resistance at the heating temperature during transfer, for example, that it does not deform and / or shrink.

[0126] The temporary substrate may be single-layered or multi-layered. If the temporary substrate is multi-layered, it is preferable that it comprises a plastic film, a release layer laminated on one side of the plastic film, a protective layer, and a receiving layer in this order. The temporary substrate may also comprise other layers besides the plastic film, release layer, protective layer, and receiving layer, but it is preferable that the receiving layer is formed on the outermost surface of the temporary substrate.

[0127] As the release layer, the example and described above can be used as the release layer of the film substrate (a).

[0128] There are no particular limitations on the method for forming the above-mentioned release layer. The release layer can be prepared by dissolving or dispersing each of the above-mentioned components in a suitable solvent, applying and drying this coating solution on one surface of a temporary substrate, and then drying and curing the resulting composition layer. Alternatively, the release layer can be applied (coated) onto a release liner, the resulting composition layer can be cured by irradiating it with active energy rays, and then transferred onto a temporary substrate. Furthermore, if necessary, it may be further heated and dried.

[0129] The protective layer described above is provided to improve peelability when transferring the decorative layer and adhesive layer from the temporary substrate, and to protect the decorative layer after peeling. Because the adhesion between the protective layer and the release layer is relatively small, it is possible to easily separate the protective layer and the release layer during the laminate transfer process described later.

[0130] The protective layer described above may be the specific example and description of the release layer. The protective layer may have the same composition as the release layer, but it is preferable that it has a different composition. In particular, from the viewpoint of excellent scratch resistance, the protective layer is preferably made of polyester resin, and more preferably has a higher polyester resin content than the release layer.

[0131] There are no particular limitations on the method for forming the protective layer described above. The protective layer can be prepared by dissolving or dispersing each of the above components in a suitable solvent, applying and drying this coating solution on one surface of the release layer to dry and harden the resulting composition layer, or by applying (coating) the protective layer coating solution onto a release liner, irradiating the resulting composition layer with active energy rays to harden it, and then transferring it onto the release layer. If necessary, further heating and drying may be performed.

[0132] The receiving layer has excellent adhesion to the decorative layer and preferably contains a resin component (particularly a thermoplastic resin). Specifically, examples include polyolefins such as polypropylene, halogenated resins such as polyvinyl chloride or polyvinylidene chloride, vinyl resins such as polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer or polyacrylic acid ester, polyesters such as polyethylene terephthalate or polybutylene terephthalate, polystyrene, polyamide, ethylene, or copolymers of olefins such as propylene with other vinyl polymers, ionomers, or cellulose resins such as cellulose diastase, polycarbonate, epoxy resin, etc. Among these, the receiving layer preferably contains polyvinyl chloride, acrylic-styrene resin, or polyester.

[0133] There are no particular limitations on the method for forming the above-mentioned receiving layer. The receiving layer can be prepared by dissolving or dispersing each of the above-mentioned components in a suitable solvent, applying and drying this coating solution onto one surface of the protective layer to dry and harden the resulting composition layer, or by applying (coating) the above-mentioned receiving layer coating solution onto a release liner, irradiating the resulting composition layer with active energy rays to harden it, and then transferring it onto the protective layer. Furthermore, if necessary, it may be further heated and dried.

[0134] The thickness of the receiving layer is not particularly limited, but 1 to 10 μm is preferred from the viewpoint of exhibiting sufficient heat resistance.

[0135] (Adhesive layer transfer process) In the adhesive layer transfer process described above, as shown in Figure 12, the adhesive layer 3 formed on the film substrate (b) 9 is heated and transferred onto the decorative layer 4 formed on one side of the temporary substrate 7. Note that the adhesive layer 3 does not need to be formed over the entire surface of the film substrate (b) 9, but may be formed only in a portion of the area including the area to be transferred. When the adhesive layer 3 is heat-transferred onto the decorative layer 4, in particular, if the heat-transferable resin contained in the adhesive layer 3 and the heat-transferable resin contained in the decorative layer 4 are of the same type, the area near the boundary between the decorative layer 4 and the adhesive layer 3 will be compatible, resulting in excellent adhesion between the adhesive layer 3 and the decorative layer 4, and consequently, excellent adhesion of the decorative layer 4 to the substrate 2.

[0136] As the film substrate (b), those exemplified and described above as film substrate (a) can be used. Furthermore, since the film substrate (b) is heated in the adhesive layer transfer process, it is preferable that it has heat resistance at the heating temperature during transfer, for example, that it does not deform and / or shrink.

[0137] The adhesive layer described above can be formed on the film substrate (b) by known or conventional methods. For example, the adhesive layer can be produced by coating the film substrate (b) with a composition for forming an adhesive layer (adhesive composition) and drying and curing the resulting adhesive composition layer, or by coating the adhesive composition onto a release liner, curing the resulting adhesive composition layer by irradiating it with active energy rays, and then transferring it onto the film substrate (b). If necessary, it may also be further heated and dried.

[0138] A known coating method may be used for applying (coating) the above adhesive composition. For example, coaters such as gravure roll coaters, reverse roll coaters, kiss roll coaters, dip roll coaters, bar coaters, knife coaters, spray coaters, comma coaters, and direct coaters may be used.

[0139] In the adhesive layer transfer process described above, first, the adhesive layer 3 formed on the film substrate (b) 9 is brought into contact with the side of the temporary substrate 7 that has the decorative layer 4 (Figure 12(a)). Next, the adhesive layer 3 is brought into contact with the decorative layer 4 on the temporary substrate 7 (Figure 12(b)), and heating can be performed from the side of the film substrate (b) 9 that does not have the adhesive layer 3. Heating is performed selectively, selecting only the area of ​​the adhesive layer 3 to be transferred. Heating can be performed using a known heating jig 10. In Figure 12(b), the adhesive layer that has been heated selectively is indicated by 3a. The temperature during heating is appropriately selected depending on the type of adhesive layer, and is, for example, 60 to 250°C, or 80 to 200°C. After heating, the film substrate (b) 9 is peeled off from the temporary substrate 7, the selectively heated adhesive layer 3 is transferred onto the decorative layer 4, and the unheated adhesive layer 3 is peeled off from the temporary substrate 7 together with the film substrate (b) 9 (Figure 12(c)).

[0140] It is preferable that the amount of heat used when heating during the transfer of the adhesive layer 3 is less than the amount of heat used when heating during the transfer of the decorative layer 4. In this case, when the adhesive layer 3 is brought into contact with the decorative layer 4 and the film substrate (b) 9 is peeled off, the so-called reverse transfer of the decorative layer 4, where the heated layer 4 is transferred to the adhesive layer 3 and then to the film substrate (b) 9, can be suppressed.

[0141] After transferring the adhesive layer 3, the adhesive layer 3 may be cured. Curing may be performed before the next step, after any of the subsequent steps, or all at once if there are multiple adhesive layers 3. The curing operation is appropriately selected according to the type of curability of the adhesive layer described above.

[0142] (Laminate transfer process) In the laminate transfer process described above, as shown in Figure 13, the laminate of the decorative layer 4 and adhesive layer 3 formed on the temporary substrate 7 is heated and transferred onto the substrate 2. In the laminate transfer process, first, the decorative layer 4 and adhesive layer 3 formed on the temporary substrate 7 are placed facing one side of the substrate 2 (Figure 13(a)). Next, the adhesive layer 3 is brought into contact with one side of the substrate 2 (Figure 13(b)). Then, heat lamination is performed by applying pressure with a roll 11 from the side of the temporary substrate 7 that does not have the decorative layer 4 and adhesive layer 3. After that, the temporary substrate 7 is peeled off from the substrate 2, and the decorative layer 4 and adhesive layer 3 are transferred onto the substrate 2 (Figure 13(c)). Alternatively, the transfer may be performed by heat pressing instead of heat lamination. In this way, the laminate 1 shown in Figure 1 can be manufactured.

[0143] Here, when the laminate of the adhesive layer 3 and the decorative layer 4 is transferred onto the substrate 2, especially when the heat-transferable resin contained in the adhesive layer 3 and the heat-transferable resin contained in the decorative layer 4 are of the same type, the area near the boundary between the decorative layer 4 and the adhesive layer 3 becomes compatible, resulting in excellent adhesion between the adhesive layer 3 and the decorative layer 4, and consequently, excellent adhesion of the decorative layer 4 to the substrate 2.

[0144] When manufacturing a laminate 1 in which the decorative layer 4 is multilayered, as shown in Figure 2, the decorative layer transfer step may be performed multiple times in succession. Also, when manufacturing a laminate 1 in which the adhesive layer 3 is formed over the entire surface, as shown in Figure 3, the adhesive layer 3 can be transferred to the entire surface of the temporary substrate 7 by heating the entire surface of the film substrate (b) 9 in the adhesive layer transfer step. Furthermore, when manufacturing a laminate 1 in which the adhesive layer 3 is provided on both sides of the substrate 2, as shown in Figure 4, the adhesive layer 3 on the film substrate (b) 9 obtained by the adhesive layer transfer step can be transferred to the other surface of the substrate in the same manner as in the laminate transfer step, either after the laminate transfer step or before the decorative layer transfer step, thereby forming the adhesive layer 3 on the other surface of the substrate 2. Furthermore, when manufacturing a laminate 1 in which the adhesive layer 3 covers the decorative layer 4, as shown in Figure 5, the laminate can be manufactured by performing the laminate transfer step on a laminate obtained by going through the adhesive layer transfer step, which selectively transfers the adhesive layer, the decorative layer transfer step, and the adhesive layer transfer step, which transfers the adhesive layer to the entire surface of the temporary substrate, in that order.

[0145] Furthermore, if the temporary substrate comprises a plastic film, a release layer laminated on one side of the plastic film, a protective layer, and a receiving layer in this order, when transferring the laminate of the adhesive layer 3 and the decorative layer 4 to the substrate 2, the protective layer and the receiving layer can also be transferred onto the substrate 2 together with the adhesive layer 3 and the decorative layer 4. The presence of the protective layer and the receiving layer on the decorative layer 4 protects the decorative layer 4. Also, if the adhesive layer 3 is in contact with the receiving layer, the protective layer and the receiving layer may be transferred onto the adhesive layer 3.

[0146] (Adhesive layer transfer process) If the laminate of the present invention includes an adhesive layer as shown in Laminate 1 in Figures 6 to 10, the above manufacturing method may include a step of transferring the adhesive layer to a substrate (adhesive layer transfer step) after the laminate transfer step.

[0147] The above-mentioned adhesive layer can be manufactured, for example, by applying an adhesive composition for forming the adhesive layer onto a release liner and drying and curing the resulting adhesive composition layer, or by applying the above-mentioned adhesive composition onto a release liner and curing the resulting adhesive composition layer by irradiating it with active energy rays. Furthermore, if necessary, it may be further heated and dried.

[0148] Known coating methods may be used for applying (coating) the above adhesive composition. For example, coaters such as gravure roll coaters, reverse roll coaters, kiss roll coaters, dip roll coaters, bar coaters, knife coaters, spray coaters, comma coaters, direct coaters, and die coaters may be used.

[0149] In the above adhesive layer transfer process, the adhesive layer formed on the release liner is transferred onto the substrate. In the above adhesive layer transfer process, first, the adhesive layer formed on the release liner is placed facing one side of the substrate. Next, the adhesive layer is brought into contact with one side of the substrate. Then, lamination is performed by applying pressure with a roll from the side of the release liner that does not have the adhesive layer. Heating may be applied during lamination. After that, the release liner is peeled off the substrate, and the adhesive layer is transferred onto the substrate.

[0150] (Release liner application process) A release liner may be attached to the laminate of the present invention obtained as described above (release liner attachment step). The release liner may be attached to one side of the laminate of the present invention, or to both sides, or one release liner with both sides being release surfaces may be attached to one side.

[0151] The manufacturing method described in (ii) above includes, for example, at least a step of heating an adhesive layer formed on a film substrate (b) and transferring it onto the substrate (adhesive layer transfer step), and a step of heating a decorative layer formed on a film substrate (a) and transferring it onto the adhesive layer (decorative layer transfer step). The adhesive layer transfer step in the manufacturing method described in (ii) above can be carried out in the same manner as the adhesive layer transfer step in the manufacturing method described in (i) above, except that the adhesive layer on the film substrate (b) is transferred to one side of the substrate rather than onto a decorative layer formed on a temporary substrate. Furthermore, the decorative layer transfer step in the manufacturing method described in (ii) above can be carried out in the same manner as the decorative layer transfer step in the manufacturing method described in (i) above, except that the decorative layer on the film substrate (a) is transferred to an adhesive layer formed on one side of the substrate rather than onto a temporary substrate. The manufacturing method described in (ii) above may also include an adhesive layer transfer step and / or a release liner application step in the manufacturing method described in (i) above.

[0152] The method for manufacturing the laminate of the present invention may involve continuously performing each of the above steps by roll-to-roll. Specifically, the temporary substrate can be unwound from a wound body in which the temporary substrate is wound, while performing the decorative layer transfer step, the adhesive layer transfer step, the laminate transfer step, and optionally the adhesive layer transfer step and / or the release liner application step, and the resulting laminate can be wound up to obtain the laminate as a wound body. In this case, the order and number of times the decorative layer transfer step, the adhesive layer transfer step, and the laminate transfer step are appropriately selected depending on the layer configuration of the laminate. Furthermore, the laminate of film substrate (a) and decorative layer, the laminate of film substrate (b) and adhesive layer, the laminate of release liner and adhesive layer, and the substrate provided in the roll-to-roll process may each be unwound from a wound body. In addition, after each of the above steps, the film substrate (a), film substrate (b), and temporary substrate may be wound up to form a wound body. After transferring the release liner, which has an adhesive layer, to the laminate, the release liner is wound up together with the laminate while protecting the adhesive layer.

[0153] While alkali glass is commonly used for glass sheets, its hydrophilic surface allows for the formation of highly adhesive decorative layers to the glass using conventional printing methods such as screen printing. However, chemically strengthened glass and alkali-free glass, although thin, possess high strength and excellent bending resistance. Their smooth and highly hydrophobic surfaces make it difficult to form highly adhesive decorative layers to them using conventional printing methods such as screen printing. In contrast, the laminate of the present invention contains a heat-transferable resin for both the decorative layer and the adhesive layer. This allows the decorative layer and adhesive layer to be formed on a substrate of chemically strengthened glass or alkali-free glass by a transfer method using the manufacturing method described above. In such a laminate of the present invention, the adhesive layer, decorative layer, and even the adhesive layer exhibit excellent adhesion to chemically strengthened glass or alkali-free glass, which have smooth and highly hydrophobic surfaces, and each layer is less likely to detach from the chemically strengthened glass or alkali-free glass. Furthermore, the decorative layer is less likely to detach from the chemically strengthened glass or alkali-free glass when the laminate of the present invention is subjected to impact or repeated bending. Furthermore, while screen printing requires coating the glass and subsequent drying and firing processes, the laminate of the present invention can be manufactured by a method other than screen printing, eliminating the need for drying and firing processes, thus enabling efficient and energy-saving manufacturing. In addition, while screen printing typically forms an adhesive layer only partially, the laminate of the present invention allows for the formation of an adhesive layer over the entire surface of the chemically strengthened glass or alkali-free glass substrate, thereby improving the adhesion between the adhesive layer and the chemically strengthened glass or alkali-free glass.

[0154] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. [Examples]

[0155] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples.

[0156] Example 1 <Preparation of the adhesive layer> (Preparation of adhesive composition) An epoxy solution was prepared by mixing 100 parts by mass of 1,2-epoxy-4-(2-oxyranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (trade name "Celoxide EHPE3150", manufactured by Daicel Corporation) and 100 parts by mass of ethyl acetate as an epoxy polymer and stirring. To the epoxy solution, 5 parts by mass of diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate (trade name "CPI-110P", manufactured by Sunapro Co., Ltd.) and 425 parts by mass of ethyl acetate were added as photoacid generators and stirred to obtain an adhesive composition.

[0157] (Formation of adhesive layer) The adhesive composition was applied to the side of a polyester film (product name "Lumirror 5AF531," manufactured by Toray Industries, Inc.) opposite to the side coated with a heat-resistant coating to form an adhesive composition layer. By drying at 80°C for 1 minute, an adhesive layer with a thickness of 2 μm was formed, resulting in an adhesive sheet with an adhesive layer formed on the polyester film.

[0158] <Fabrication of laminates> Chemically strengthened glass (alkali-free glass) (product name "Gorilla Glass 3", manufactured by Matsunami Glass Industry Co., Ltd., 200 mm wide, 300 mm long, 1 mm thick) was prepared, and the adhesive layer surface of the adhesive sheet was placed in contact with one side of the chemically strengthened glass. Then, using a hot press device (product number "MP-WCH", manufactured by Toyo Seiki Seisakusho Co., Ltd.), a hot press was performed for 30 seconds at a temperature of 100°C and a pressure of 10 kN to heat-press the chemically strengthened glass and the adhesive sheet. After heat pressing, the polyester film of the adhesive sheet was peeled off, and the adhesive layer was transferred onto the chemically strengthened glass to obtain chemically strengthened glass with an adhesive layer having a laminated structure of [chemically strengthened glass / adhesive layer].

[0159] Next, an ink ribbon (product name "TTR_40MM", manufactured by KOGLEE) was prepared and placed so that the decorative layer of the ink ribbon was in contact with the adhesive layer of the chemically strengthened glass with the adhesive layer. Then, using the hot press device described above, a hot press was performed for 30 seconds at a temperature of 100°C and a pressure of 10kN to heat-press the chemically strengthened glass with the adhesive layer and the ink ribbon, transferring the decorative layer onto the adhesive layer and obtaining a laminate having a layered structure of [chemically strengthened glass / adhesive layer / decorative layer].

[0160] Next, using a UV-LED irradiation device (model number "QEL-350-RU6W-CW-MY", manufactured by Quark Technology Inc.), a 365nm wavelength UV-LED lamp was used as the light source, and the integrated irradiation light dose was 2 J / cm². 2 The entire surface of the laminate was irradiated with ultraviolet light from the chemically strengthened glass side to cure the adhesive layer. Then, the base film of the ink ribbon was peeled off to obtain a laminate having a laminated structure of [chemically strengthened glass / adhesive layer / decorative layer].

[0161] Examples 2-7 A laminate was prepared in the same manner as in Example 1, except that the composition of the adhesive composition was changed as shown in Table 1.

[0162] Example 8 A laminate was fabricated in the same manner as in Example 4, except that the composition of the decorative layer in the ink ribbon was changed as shown in Table 1.

[0163] Examples 9, 10 The laminate was prepared in the same manner as in Example 1, except that the composition of the adhesive composition was changed as shown in Table 1 and the adhesive layer was not cured by ultraviolet irradiation.

[0164] Comparative Example 1 Chemically strengthened glass (alkali-free glass) (product name "Gorilla Glass 3", manufactured by Matsunami Glass Industry Co., Ltd., 200 mm wide, 300 mm long, 1 mm thick) was prepared, and the decorative layer of the ink ribbon (product name "TTR_40MM", manufactured by KOGLEE) was placed in contact with the chemically strengthened glass. Then, using a hot press device (product number "MP-WCH", manufactured by Toyo Seiki Seisakusho Co., Ltd.), a hot press was performed for 30 seconds at a temperature of 100°C and a pressure of 10 kN to heat-press the chemically strengthened glass and the ink ribbon. The decorative layer was transferred onto the chemically strengthened glass to obtain a laminate having a [chemically strengthened glass / decorative layer] laminated structure.

[0165] Comparative Example 2 A laminate was fabricated in the same manner as in Comparative Example 1, except that the composition of the decorative layer in the ink ribbon was changed as shown in Table 1.

[0166] The components shown in Table 1 are as follows: <Thermal transfer resin> EHPE3150: Product name "Celoxide EHPE3150", manufactured by Daicel Corporation, curable epoxy resin KRM-9322: Product name "KRM-9322", manufactured by Daicel Ornex Co., Ltd., acrylic resin. MAP-7000: Product name "MAP-7000", manufactured by Negami Kogyo Co., Ltd., acrylic resin (acrylate) Urethane polymer: Product name "UN-954", manufactured by Negami Kogyo Co., Ltd., urethane acrylate resin <Additives> CPI-110P: Product name "CPI-110P", manufactured by Sunapro Co., Ltd., diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate, photoacid generator Omnirad 184: Product name "Omnirad 184", manufactured by IGM Resins Italia Srl, photoradical generator. Omnirad 651: Product name "Omnirad 651", manufactured by IGM Resins Italia Srl, photoradical generator. <Thermal transfer ink (ink ribbon)> TTR: Product name "TTR_40MM", manufactured by KOGLEE. 10PN: Product name "Duraink 10PN", manufactured by Nitto Denko Corporation

[0167] [evaluation] The laminates obtained in the examples and comparative examples were evaluated as follows, and the results are shown in Table 1. Note that, in measuring the storage modulus, for the adhesive layers of Examples 1 to 8, which are UV-curable, the tensile storage modulus was used because the modulus was high after UV curing, making it impossible to properly measure the shear storage modulus.

[0168] (1) Transferability of the adhesive layer In the examples, when the adhesive layer was transferred onto chemically strengthened glass and the polyester film was peeled off, the transferability of the adhesive layer was visually evaluated based on the area on which the adhesive layer was transferred to the chemically strengthened glass. When the total area of ​​the adhesive layer to be transferred was set to 100%, a transfer rate of 95% or more of the adhesive layer to the chemically strengthened glass was evaluated as "○", an evaluation of 80% or more but less than 95% was evaluated as "△", and an evaluation of less than 80% was evaluated as "×".

[0169] (2) Transferability of the decorative layer In the examples and comparative examples, when the decorative layer was transferred onto the adhesive layer and the base film of the ink ribbon was peeled off, the transferability of the decorative layer was visually evaluated based on the area on which the decorative layer was transferred to the chemically strengthened glass. When the total area of ​​the decorative layer to be transferred was set to 100%, a transfer rate of 95% or more of the decorative layer onto the adhesive layer was marked as "○", a transfer rate of 80% or more but less than 95% was marked as "△", and a transfer rate of less than 80% was marked as "×".

[0170] (3) Adhesion ([chemically strengthened glass / adhesive layer]) A cross-cut test was performed using the chemically strengthened glass with an adhesive layer prepared in the example. Six vertical and six horizontal cuts were made at 2 mm intervals to form a grid pattern of 25 squares. Adhesive tape (product name "Sellotape", manufactured by Nichiban Co., Ltd.) was applied to the grid pattern and peeled off at an angle of approximately 60° for 0.5 to 1 second. When peeled, "○" was used if no peeling occurred in any of the grids, "△" was used if peeling of the adhesive layer occurred but the peeled area was less than 5%, and "×" was used if peeling of 5% or more of the adhesive layer occurred. For samples where the transferability of the adhesive layer was "×" or "△" in the above adhesive layer transferability evaluation, the evaluation was performed by selecting the areas where transfer occurred.

[0171] (4) Adhesion ([chemically strengthened glass / adhesive layer / decorative layer]) A cross-cut test was performed using the laminates prepared in the examples. Six vertical and horizontal cuts were made at 2 mm intervals to form a grid pattern of 25 squares. Adhesive tape (product name "Sellotape", manufactured by Nichiban Co., Ltd.) was applied to the grid pattern and peeled off at an angle of approximately 60° for 0.5 to 1 second. When peeled, "○" was used if no peeling occurred in any of the grids, "△" was used if peeling of the adhesive layer or decorative layer occurred but the peeled area was less than 5%, and "×" was used if peeling of 5% or more of the adhesive layer or decorative layer occurred. For samples where the transferability of the decorative layer was "×" or "△" in the above evaluation, the evaluation was performed by selecting the areas where transfer occurred.

[0172] (5) Shear storage modulus (modulus before hardening) A layer of adhesive was laminated to a thickness of 1.0 mm to 2.0 mm, which was then punched out into an 8 mm diameter disc shape to be used as a measurement sample. During lamination, the adhesive layer was heated to 50°C as needed. Using a rheometer (product name "ARES-G2", manufactured by TA Instruments), the elastic modulus was measured in torsion mode under the conditions of a measurement frequency of 1 Hz, a measurement temperature of -50°C to 150°C, and a heating rate of 5°C / min. The elastic modulus G1' at 25°C and the elastic modulus G2' at 100°C were obtained. Furthermore, even below 150°C, the elastic modulus was 10 3If the reading fell below Pa, the measurement was terminated at that point. For G2', the temperature was 100°C or below. 3 If it falls below Pa, 10 3 It was recorded as less than Pa.

[0173] (6) Glass transition temperature (Tg) The peak temperature of tanδ (= loss modulus G'' / storage modulus G') during the measurement of the shear storage modulus described above was recorded as Tg. When there were two or more peaks, the lower temperature was recorded as Tg. When there were no peaks, it was recorded as "no Tg".

[0174] (7) Tensile storage modulus (modulus after hardening) The adhesive layers from Examples 1 to 8 were laminated to a thickness of 10 μm to 100 μm and sandwiched between two release liners. Using a UV-LED irradiation device (product name "QEL-350-RU6W-CW-MY", manufactured by Quark Technology Inc.), a UV-LED lamp with a wavelength of 365 nm was used as the light source, and the integrated irradiation amount was 2 J / cm². 2 The adhesive layer was cured by ultraviolet irradiation. After cutting the cured adhesive layer into pieces 5 mm wide x 50 mm long, the release liner was removed from both sides. Next, the dynamic viscoelasticity was measured using a rheometer (product name "RSA G2", manufactured by TA Instruments) under the conditions of a frequency of 1 Hz, a heating rate of 5 °C / min, and a measurement temperature of -50 to 150 °C. The tensile storage modulus E3' was measured in the above manner.

[0175] [Table 1]

[0176] As shown in Table 1, in the comparative example, the decorative layer could not be transferred onto the chemically strengthened glass without an adhesive layer. In contrast, in the example, both the adhesive layer and the decorative layer could be transferred onto the chemically strengthened glass by transfer. Furthermore, the laminate of the example was evaluated as having high adhesion between the adhesive layer and the decorative layer to the chemically strengthened glass, and the decorative layer was less likely to fall off.

[0177] Example 11 In the following embodiments, the effect of the presence or absence of an adhesive layer on improving the adhesion of the adhesive layer to a chemically strengthened glass substrate was investigated. Since a decorative layer is not necessary for confirming the above adhesion improvement effect, the evaluation was performed in a configuration without a decorative layer.

[0178] Chemically strengthened glass (alkali-free glass) (product name "Gorilla Glass 3", manufactured by Matsunami Glass Industry Co., Ltd., 200 mm wide, 300 mm long, 1 mm thick) was prepared, and the adhesive layer surface of the adhesive sheet prepared in Example 1 was placed in contact with one side of the chemically strengthened glass. Then, using a hot press device (product number "MP-WCH", manufactured by Toyo Seiki Seisakusho Co., Ltd.), a hot press was performed for 30 seconds at a temperature of 100°C and a pressure of 10 kN to heat-press the chemically strengthened glass and the adhesive sheet. After heat pressing, the polyester film of the adhesive sheet was peeled off, and the adhesive layer was transferred onto the chemically strengthened glass to obtain chemically strengthened glass with an adhesive layer having a laminated structure of [chemically strengthened glass / adhesive layer].

[0179] Examples 12-16 Chemically strengthened glass with an adhesive layer having a laminated structure of [chemically strengthened glass / adhesive layer] was obtained in the same manner as in Example 11, except that the composition of the adhesive composition was changed as shown in Table 2.

[0180] [evaluation] The chemically strengthened glass with adhesive layers obtained in Examples 12-16 was evaluated as follows, and the results are shown in Table 1.

[0181] (8) 180° peeling force Under a measurement environment of 23°C and 50% RH, the release liner was peeled from one side of the adhesive sheet prepared in Manufacturing Example 1 below, a 50 μm thick PET film was laminated to the backing, and the sheet was cut to a size of 25 mm wide and 100 mm long to serve as a test specimen. The release liner was peeled from the other side of the test specimen, and a 2 kg roller was pressed onto the surface of the adhesive layer of the chemically strengthened glass with adhesive layer obtained in Examples 12 to 16 by one back-and-forth motion. As Comparative Example 3, chemically strengthened glass without an adhesive layer was used, and the test specimen was pressed onto the surface of the chemically strengthened glass. After leaving this in the same environment for 24 hours, the peel strength (adhesion) [N / 25 mm] was measured using a universal tensile and compression tester in accordance with JIS Z 0237:2000, under conditions of a tensile speed of 300 mm / min and a peel angle of 180 degrees. The universal tensile and compression tester used was the "Tensile and Compression Tester, TG-1kN" manufactured by Minebea Co., Ltd.

[0182] Manufacturing Example 1 (Preparation of acrylic prepolymer solution) In a reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas inlet tube, 40 parts by mass of lauryl acrylate (LA), 57 parts by mass of 2-ethylhexyl acrylate (2EHA), 3 parts by mass of 4-hydroxybutyl acrylate (4HBA), 0.25 parts by mass of photopolymerization initiator (trade name "Omnirad 819," manufactured by IGM Resins Italia Srl), and 0.05 parts by mass of photopolymerization initiator (trade name "Omnirad 184," manufactured by IGM Resins Italia Srl) were added. Then, nitrogen gas was introduced, and nitrogen purging was carried out for approximately 20 minutes while stirring. After that, 5 mW / cm² was added. 2 Polymerization was carried out by irradiating with ultraviolet light, and the reaction rate was adjusted to 5-15% to obtain an acrylic prepolymer solution.

[0183] (Formation of adhesive sheet) To the above acrylic prepolymer solution, 0.1 parts by mass of dipentaerythritol hexaacrylate (DPHA) and 0.3 parts by mass of 3-glycidyloxypropyltrimethoxysilane were added as crosslinking agents and stirred to prepare an adhesive composition. This adhesive composition was applied to the release surface of a release liner (product name "MRE38," manufactured by Mitsubishi Chemical Corporation, a polyethylene terephthalate film with a release treatment on one side, 38 μm thick) to form an adhesive composition layer, and the release surface of the release liner (product name "MRF38," manufactured by Mitsubishi Chemical Corporation) was bonded onto the adhesive composition layer. Next, a black light was used to measure 2.5 mW / cm². 2 The ultraviolet light at an illuminance of 2400 mJ / cm² is measured by the cumulative light intensity of 2400 mJ / cm². 2 Polymerization was carried out by irradiation until the desired state was reached, and an adhesive sheet (40 μm thick) was fabricated.

[0184] [Table 2]

[0185] As shown in Table 2, in the embodiment in which the adhesive layer was adhered to the chemically strengthened glass via an adhesive layer containing a heat-transferable resin, the 180° peel strength was higher and the adhesion of the adhesive layer was superior compared to the case in which the adhesive layer was adhered to the chemically strengthened glass without an adhesive layer (Comparative Example 3). Therefore, even when a decorative layer is present, it was determined that the adhesion of the adhesive layer to the chemically strengthened glass is superior when the adhesive layer containing a heat-transferable resin is on the chemically strengthened glass.

[0186] The following describes variations of the invention relating to this disclosure. [Note 1] The laminate comprises a base material, an adhesive layer laminated on at least a portion of the base material, and a decorative layer formed to be in contact with the adhesive layer. The substrate is chemically strengthened glass or alkali-free glass. The adhesive layer contains a heat-transferable resin. The decorative layer is a laminate containing a heat transfer resin. [Note 2] The laminate as described in Note 1, wherein the ratio of the thickness of the adhesive layer to the thickness of the decorative layer is 1:0.01 to 1:100. [Note 3] The decorative layer is a laminate according to Note 1 or 2, containing a pigment. [Note 4] The laminate according to any one of Notes 1 to 3, wherein at least a portion of the substrate is provided with an adhesive layer so as to be in contact with at least one of the adhesive layer and the decorative layer. [Note 5] The laminate as described in Note 4, wherein the ratio of the total thickness of the adhesive layer and the decorative layer to the thickness of the adhesive layer is 1:0.5 to 1:2500. [Explanation of symbols]

[0187] 1. Laminate 2. Chemically strengthened glass or alkali-free glass 3,31,32,3a Adhesive layer 4,4a Decorative layer 5, 51, 52 Adhesive layer 6. Film substrate (a) 7 Temporary base material 8. Heating jig 9. Film substrate (b) 10 Heating fixture 11 rolls

Claims

1. A laminate comprising a base material, an adhesive layer laminated on at least a portion of the base material, and a decorative layer formed to be in contact with the adhesive layer, The substrate is chemically strengthened glass or alkali-free glass. The adhesive layer contains a heat-transferable resin, The decorative layer is a laminate containing a heat transfer resin.

2. The laminate according to claim 1, wherein the ratio of the thickness of the adhesive layer to the thickness of the decorative layer is 1:0.01 to 1:

100.

3. The laminate according to claim 1 or 2, wherein the decorative layer comprises a pigment.

4. The laminate according to claim 1 or 2, wherein at least a portion of the substrate is provided with an adhesive layer so as to be in contact with at least one of the adhesive layer and the decorative layer.

5. The laminate according to claim 4, wherein the ratio of the total thickness of the adhesive layer and the decorative layer to the thickness of the adhesive layer is 1:0.5 to 1:2500.

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