Member for display device and film for member for display device

Abstract

The present invention relates to a member for a display device obtained by laminating an impact absorption layer and a protective layer. The impact absorption layer contains a reaction product of a telechelic polymer having between 3.0 and 5.0 reactive functional groups (both inclusive) per molecule and a weight average molecular weight of 2,000 or more.

Description

Display device components, film for display device components

[0001] The present invention relates to a component for a display device and a film for a display device component.

[0002] In recent years, the proliferation of display-equipped devices such as smartphones, tablets, personal computers, wearable devices, and televisions has been increasing. In particular, the development of new flexible displays such as foldable displays, bendable displays, rollable displays, slidable displays, and stretchable displays is progressing.

[0003] Given this situation, it is expected that new technological areas will emerge where materials used in conventional displays and devices are insufficient, leading to an increased need for materials suitable for new flexible displays. In particular, flexible displays are expected to undergo thinning of their constituent materials to achieve their flexibility. Therefore, to compensate for the decrease in strength of the display and its constituent materials due to thinning, there is a potential need for impact-resistant materials.

[0004] Under these circumstances, Patent Document 1 describes an impact-absorbing sheet comprising a silicone-containing layer containing a silicone resin and an adhesive layer overlapping the silicone-containing layer, wherein the thickness of the silicone-containing layer is 60% to 95% of the thickness of the impact-absorbing sheet, and the storage modulus of the silicone-containing layer at -20°C (G1) and at 25°C (G2) are both 1 × 10 ４ Pa or more 1×10 ５ An impact-absorbing sheet has been proposed in which the adhesive layer contains a resin (A) whose pressure is Pa or less and whose peak temperature of loss tangent is 0°C or less.

[0005] Further, Patent Document 2 proposes "a shock absorbing film having a laminate, wherein the laminate essentially consists of only: A) a first stretchable film having a 10% tensile modulus of 0.15 to 0.5 N / 10 mm and having stretchability to return to the original length when the tensile force is removed; and B) a foam having a thickness of 0.05 mm or more and 0.5 mm or less, wherein the foam has a repulsive stress of 0.02 MPa or more and 3.0 MPa or less, measured when a sheet consisting only of said foam is stacked to a thickness of 1 cm and compressed to a thickness of 50%; the above-described shock absorbing film."

[0006] Furthermore, Patent Document 3 discloses "a shock absorbing sheet having a storage elastic modulus at 23°C of 1.0×10 ５ Pa or more and 2.5×10 ７ Pa or less, a tanδ at 23°C of 0.3 or more, and a density of 600 kg / m ３ or more."

[0007] Japanese Unexamined Patent Application Publication No. 2022-98240, Japanese Unexamined Patent Application Publication No. 2016-30394, International Publication No. WO2018 / 131619

[0008] As a shock absorbing material used for the aforementioned flexible displays and the like, there is a demand for a material that not only has impact resistance, but also has optical properties suitable for display materials, and more preferably is a thin film. However, the materials proposed in Patent Documents 1 to 3 did not satisfy all of these requirements.

[0009] Therefore, an object of the present invention is to provide a member for a display device and a film for a member for a display device that are excellent in impact resistance.

[0010] To solve the above problems, the present inventors have diligently conducted research and have completed the following invention. That is, a preferred embodiment of the present invention is as follows: <1> A display device member comprising a shock-absorbing layer and a protective layer laminated together, wherein the shock-absorbing layer comprises a reaction product of a telechelic polymer having 3.0 to 5.0 reactive functional groups per molecule and a weight-average molecular weight of 2,000 or more. <2> The display device member according to <1>, wherein the shock-absorbing layer is laminated on one side of the protective layer, or the shock-absorbing layer is laminated on both sides of the protective layer. <3> The display device member according to <1> or <2>, wherein the shock-absorbing layer satisfies conditions 1 and 2. Condition 1: The tensile yield strain of the shock-absorbing layer at 25°C, as described in JIS K7161 (2014), is 20% or more. Condition 2: The elastic limit strain of the shock-absorbing layer at 25°C is 20% or more. <4> A display device component comprising a shock-absorbing layer and a protective layer laminated together, wherein the shock-absorbing layer satisfies conditions 1 and 2. Condition 1: The tensile yield strain of the shock-absorbing layer at 25°C, as described in JIS K7161 (2014), is 20% or more. Condition 2: The elastic limit strain of the shock-absorbing layer at 25°C is 20% or more. <5> The display device component according to <4>, wherein the shock-absorbing layer is laminated on one side of the protective layer, or the shock-absorbing layer is laminated on both sides of the protective layer. <6> A display device component according to any of <1> to <5>, satisfying the following conditions 3 and 4. Condition 3: The glass transition temperature of the shock-absorbing layer in a dynamic viscoelastic test is -40°C or higher and 30°C or lower. Condition 4: The loss tangent at the glass transition temperature in a dynamic viscoelastic test of the shock-absorbing layer is 0.5 or higher. <7> A display device component according to any of <1> to <6>, satisfying the following condition 5. Condition 5: The tensile hysteresis loss at 20% strain as defined in JIS K7312 (1996) at 25°C of the shock-absorbing layer is less than 10%. <8> A display device component according to any of <1> to <7> that satisfies the following conditions 6 and 7.Condition 6: The impact absorbing layer has an elastic modulus of 1 MPa or more and 1,000 MPa or less as specified in JIS K 7312 (1996) at 25°C. Condition 7: The impact absorbing layer has an elongation at break of 50% or more as specified in JIS K 7312 (1996) at 25°C. <9> The member has a protective layer on the outermost layer on the viewing side (the protective layer provided on the outermost layer on the viewing side is referred to as a surface protective layer), has the surface protective layer, the impact absorbing layer, and the protective layer in this order, wherein the surface protective layer and at least one layer of the impact absorbing layer are directly laminated, and the thickness T of the surface protective layer. １ and the thickness T of the impact absorbing layer ２ satisfy Formula 1, the display device member according to any one of <1> to <8>. Formula 1: 0.4 ≦ T １ / (T １ + T ２ ) ≦ 0.8 <10> The display device member according to any one of <1> to <9>, wherein the impact absorbing layer comprises segments of Chemical Formula 1 to Chemical Formula 3 below.

[0011]

[0012]

[0013]

[0014] R １ represents a hydrogen atom or a methyl group. R ２ represents any one of the following: a substituted or unsubstituted alkylene group; a substituted or unsubstituted arylene group; an alkylene group having an ether group, an ester group, or an amide group in its structure; an arylene group having an ether group, an ester group, or an amide group in its structure; an unsubstituted alkylene group having an ether group, an ester group, or an amide group in its structure; an unsubstituted arylene group having an ether group, an ester group, or an amide group in its structure. R ３ represents any one of the following: a substituted or unsubstituted alkylene group; a substituted or unsubstituted arylene group. R ４<11> The display device member according to any one of <1> to <10>, wherein the shock-absorbing layer includes a segment of the following chemical formula 4.

[0015]

[0016] R ５ , R ６ and R ７ This refers to one of the following. Note that R ５ , R ６ and R ７ These may be the same or different. A substituted or unsubstituted alkylene group A substituted or unsubstituted arylene group <12> A film for a display device component used in the shock-absorbing layer of a display device component comprising a laminate of a shock-absorbing layer and a protective layer, wherein the tensile yield strain at 25°C as described in JIS K7161 (2014) is 20% or more. <13> The film for a display device component according to <12>, comprising a reaction product of a telechelic polymer having 3.0 to 5.0 reactive functional groups per molecule and a weight-average molecular weight of 2,000 or more.

[0017] According to the present invention, it is possible to provide display device components and films for display device components that have excellent impact resistance.

[0018] Figure 1 is a cross-sectional view showing an example of a display device component in this disclosure. Figure 2 is a cross-sectional view showing an example of a display device component in this disclosure. Figure 3 is a cross-sectional view showing an example of a display device component in this disclosure. Figure 4 is a cross-sectional view showing an example of a display device component in this disclosure. Figure 5 is a cross-sectional view showing an example of a display device component in this disclosure. Figure 6 is a cross-sectional view showing an example of a display device component in this disclosure. Figure 7 is a cross-sectional view showing an example of a display device component in this disclosure. Figure 8 is a cross-sectional view showing an example of a display device component in this disclosure. Figure 9 is a cross-sectional view showing an example of a display device component in this disclosure. Figure 10 is a cross-sectional view showing an example of a display device using a display device component in this disclosure. Figure 11 is a cross-sectional view showing an example of an impact absorption layer using a support substrate in this disclosure. Figure 12 is a cross-sectional view showing an example of an impact absorption layer using a support substrate in this disclosure. Figure 13 is a diagram of the configuration of an apparatus for evaluating impact resistance in this disclosure. Figure 14 is a diagram of the configuration of an apparatus for evaluating impact resistance in this disclosure.

[0019] The embodiments of the present invention will be described in detail below. Note that the numerical values ​​used in this disclosure are rounded to one decimal place.

[0020] A preferred embodiment of the display device component of the present disclosure is a display device component comprising a shock-absorbing layer and a protective layer laminated together, wherein the shock-absorbing layer contains a reaction product of a telechelic polymer having 3.0 to 5.0 reactive functional groups per molecule and a weight-average molecular weight of 2,000 or more.

[0021] It is preferable that the shock-absorbing layer contains a reaction product of a telechelic polymer having 3.0 to 5.0 reactive functional groups per molecule and a weight-average molecular weight of 2,000 or more, as this improves resilience and tensile yield strain, and suppresses tensile hysteresis loss, thereby improving the shock resistance and flexural resistance of the display device. If the number of reactive functional groups per molecule or the weight-average molecular weight does not meet the above range, or if the reaction product of the telechelic polymer is not included, the shock resistance and flexural resistance of the display device may be insufficient when it undergoes significant deformation under severe load.

[0022] The present inventors conducted a detailed study on the chemical structure of materials used in display device components, particularly in the shock-absorbing layer. As a result, it was found that the shock-absorbing layer used in the display device component of this disclosure preferably contains a reaction product of a telechelic polymer having 3.0 to 5.0 reactive functional groups per molecule.

[0023] Here, a telechelic polymer refers to a polymer having reactive functional groups at its terminal ends that can react with each other, and having a weight-average molecular weight of 1,500 or more. In a telechelic polymer, it is preferable that two or more functional groups in one polymer molecule are of the same type. Furthermore, it is preferable that the reactive functional groups that can react with each other are addition-polymerizable functional groups. For example, a telechelic polymer having two reactive functional groups can be a telechelic polymer with a [a]-[b]-[a] structure. Here, [a] is the terminal portion which is a reactive functional group, and [b] is the main chain portion which has a flexible structure.

[0024] In this specification, "reaction product of telechelic polymer" means the product generated by the reaction of the reactive functional groups of the telechelic polymer. In the context of the impact-absorbing layer, the main component being the reaction product of a telechelic polymer having 3.0 to 5.0 reactive functional groups at its ends per molecule means that the content of the reaction product of the telechelic polymer in the impact-absorbing layer is 90% by volume or more, preferably 95% by volume or more, and more preferably 97% by volume or more. When the content is 90% by volume or more, the tensile yield strain and elastic limit strain tend to be moderately large, resulting in good impact resistance and flexural resistance. The upper limit of the proportion of the telechelic polymer reaction product in the impact-absorbing layer is, in principle, 100% by volume.

[0025] The shock-absorbing layer is required to be a flexible polymer exhibiting excellent rubber elasticity, in terms of impact resistance and bending resistance of display device components and the displays incorporating it. For a polymer to exhibit rubber elasticity, it is important to create a three-dimensional network structure by chemically or physically crosslinking flexible polymer chains.

[0026] In typical elastomers, creating a three-dimensional network structure often requires either chemical crosslinking of unsaturated bonds in the polymer chain using various chemical crosslinking agents, or physical crosslinking utilizing physical bonds such as hydrogen bonds or π-π interactions. In both cases, the crosslinked structure is located in the middle of the polymer chain, resulting in free chains (dangling chains) at the ends of the polymer chain. Since these free chain portions are not included in the three-dimensional network structure, they do not contribute to the development of rubber elasticity, and the inventors believe this is one of the reasons why the tensile yield strain of impact-absorbing layers obtained using conventional technology is low.

[0027] In response to this, the inventors considered that in order to improve the tensile yield strain as much as possible, it is important to reduce the number of free chains, increase the three-dimensional network structure as much as possible, and make the molecular weight between crosslinks uniform. When a three-dimensional crosslinked structure is created by reacting telechelic polymers, the ends of the polymers react with each other, so the resulting elastomer has a polymer network with few free chains. Therefore, by making the reaction products of telechelic polymers the main component of the shock-absorbing layer, the proportion of a uniform network structure in the resin component constituting the shock-absorbing layer can be increased, thereby obtaining an shock-absorbing layer with a high tensile yield strain.

[0028] In the impact-absorbing layer of this disclosure, the number of reactive functional groups of the telechelic polymer is preferably 3.0 to 5.0 per molecule, as described above, but more preferably 3.0 to 4.5. When the number of reactive functional groups is 3.0 or more per molecule on a weight average, the formation of a three-dimensional network structure is sufficient, and the tensile yield strain tends to be moderately large. When it is 5.0 or less per molecule, the three-dimensional network structure is not moderately dense, making it more mobile, and the proportion of rigid crosslinked portions is moderately small, resulting in a moderately large tensile yield strain and an improvement in the impact resistance and bending resistance of the display device component. Furthermore, because the three-dimensional network structure is not too dense and is easily deformed, the elongation at break may be moderately large.

[0029] In the embodiments of this disclosure, the number of reactive functional groups is calculated from the amount of material used during polymer synthesis. When the amount of material used during polymer synthesis is unknown, and the reactive functional group is an acryloyl group, the acryloyl group equivalent is determined experimentally and multiplied by the weight-average molecular weight.

[0030] As mentioned above, the type of reactive functional group is not particularly limited as long as it can react with other groups, but one or more selected from alkenyl groups, acryloyl groups, and methacryloyl groups are preferred, and acryloyl groups and / or methacryloyl groups (hereinafter sometimes referred to as "(meth)acryloyl groups") are particularly preferred.

[0031] In forming the shock-absorbing layer, the type of telechelic polymer used is not particularly limited, and different types of telechelic polymers may be mixed and used. However, it is preferable from the standpoint of reactivity and compatibility that the reactive ends of the telechelic polymer and the segments constituting the polymer are the same. In this case, the number of reactive functional groups is the sum of the number of reactive functional groups of each telechelic polymer multiplied by their mass fraction.

[0032] The weight-average molecular weight of the telechelic polymer is not particularly limited, but is preferably 2,000 or more and less than 50,000, and more preferably 8,000 or more and less than 40,000. By setting the weight-average molecular weight above the aforementioned lower limit, it is possible to suppress the proportion of rigid crosslinked portions from becoming excessively large and to prevent a decrease in tensile yield strain, thereby suppressing a decrease in the impact resistance and flexural resistance of the display device. Furthermore, by setting the weight-average molecular weight below the aforementioned upper limit, it is possible to suppress cases where the viscosity is too high, making it difficult to create an impact-absorbing layer of uniform thickness.

[0033] In forming the shock-absorbing layer, the type of telechelic polymer used is not particularly limited, and different telechelic polymers may be mixed and used. However, when mixing, it is preferable from the standpoint of reactivity and compatibility that the reactive functional groups and repeating units of the telechelic polymers be the same or similar.

[0034] Furthermore, in forming the shock-absorbing layer, compounds such as polymers or monomers that are not telechelic polymers but have the same reactive functional groups, or have different structures but reactive functional groups, may be mixed.

[0035] If the shock-absorbing layer contains reaction products of two or more types of telechelic polymers, the "number of reactive functional groups" as used herein shall be the sum of the weight-averaged values ​​obtained by multiplying the number of reactive functional groups of each telechelic polymer by their weight fraction. If the reaction products of the telechelic polymers contained in the shock-absorbing layer are products resulting from a reaction with a polymer or monomer other than a telechelic polymer that is reactive with a telechelic polymer, the number of reactive functional groups shall be limited to the reactive functional groups of the telechelic polymer only.

[0036] If the shock-absorbing layer contains reaction products of multiple types of telechelic polymers, the "weight-average molecular weight of the telechelic polymer" as used herein shall be the sum of the weight-average molecular weights of each telechelic polymer multiplied by their weight fractions; in other words, the weight-averaged value. Furthermore, if the reaction products of the telechelic polymers contained in the shock-absorbing layer are polymers other than telechelic polymers that can react with telechelic polymers, or products resulting from reactions with monomers, the weight-average molecular weight of the telechelic polymer shall only refer to that of the telechelic polymer.

[0037] Furthermore, it is preferable that the display device component of this disclosure has the shock-absorbing layer laminated on one side of the protective layer, or the shock-absorbing layer laminated on both sides of the protective layer. The shock-absorbing layer and the protective layer may be laminated directly together, or they may be laminated via other layers such as an adhesive layer, bonding layer, or primer layer.

[0038] The display device component of this disclosure exhibits impact resistance by having the impact-absorbing layer laminated on one side of the protective layer, but it can also exhibit the same effect if the impact-absorbing layer is laminated on both sides of the protective layer. Furthermore, the configuration in which the impact-absorbing layer is laminated on both sides of the protective layer is preferable because it may exhibit higher impact resistance than the configuration in which the impact-absorbing layer is laminated on one side of the protective layer.

[0039] Figure 1 shows a cross-sectional view of an example of a display device member 1 in which an impact-absorbing layer 2 is laminated on one side of a protective layer 3. Figure 2 shows a cross-sectional view of an example of a display device member 1 in which an impact-absorbing layer 2 is laminated on both sides of a protective layer 3. Figure 3 shows a cross-sectional view of an example of a display device member 1 in which an impact-absorbing layer 2 is laminated on one side of a protective layer 3 via an adhesive layer 4. Figure 4 shows a cross-sectional view of an example of a display device member 1 in which an impact-absorbing layer 2 is laminated on both sides of a protective layer 3 via an adhesive layer 4. Figure 5 shows a cross-sectional view of an example of a display device member 1 in which an impact-absorbing layer 2 is laminated on both sides of a protective layer 3, with one of these layers laminated via an adhesive layer 4.

[0040] Furthermore, it is preferable that the shock-absorbing layer of the display device component of this disclosure satisfies conditions 1 and 2. Condition 1: The tensile yield strain of the shock-absorbing layer at 25°C is 20% or more, as described in JIS K7161 (2014). Condition 2: The elastic limit strain of the shock-absorbing layer at 25°C is 20% or more. The methods for measuring the tensile yield strain and elastic limit strain will be described later.

[0041] The preferred range for the tensile yield strain of the shock-absorbing layer at 25°C is 20% or more, but more preferably 50% or more. A tensile yield strain of 20% or more at 25°C is preferable because it improves the recovery after deformation, thereby improving the impact resistance and bending resistance of the display device. The higher the tensile yield strain, the better the aforementioned effect. To achieve the tensile yield strain of the shock-absorbing layer at 25°C within the above range, for example, it is possible to select a specific resin, as described later, for the resin constituting the shock-absorbing layer.

[0042] Furthermore, the preferred range for the elastic limit strain of the shock-absorbing layer at 25°C is 20% or more, but more preferably 50% or more. A stress limit strain of 20% or more in the shock-absorbing layer at 25°C is preferable because it improves the recovery after deformation, thereby improving the shock resistance and bending resistance of the display device. The higher the elastic limit strain, the greater the aforementioned effect. To achieve the aforementioned range for the elastic limit strain of the shock-absorbing layer at 25°C, for example, it is possible to select a specific resin, as described later, for the resin constituting the shock-absorbing layer.

[0043] The inventors focused on the mechanical properties of the shock-absorbing layer and investigated its relationship with the impact resistance and bending resistance of display device components and display devices incorporating them. As a result, they found that the higher the tensile yield strain of the shock-absorbing layer, the better the impact resistance and bending resistance of the display device component.

[0044] Tensile yield strain represents the limit to which a material can deform without yielding, that is, the strain limit to which deformation can be performed without leaving permanent deformation after deformation. Elastic limit strain represents the limit of strain at which the strain completely disappears when the tensile stress is gently removed. Conventionally, when examining the impact resistance and flexural resistance of materials, the focus has been on material rheological properties. However, due to the evaluation methods, material rheological properties are based on the assumption of a linear deformation region of the material, and the mechanical properties have been evaluated by applying extremely small deformations (strain of 0.1% or less, etc.). However, according to the inventors' research, while material rheological properties are important when examining impact resistance and flexural resistance, it has been found that properties in a relatively large deformation region, such as tensile yield strain and elastic limit strain, are equally important. This is thought to be because the loads applied to display device components and the display devices using them are not necessarily limited to small deformations, and properties in a certain large deformation region are also important. A larger tensile yield strain indicates a larger region that can undergo elastic deformation during the process. Therefore, even if a large deformation occurs instantaneously in the display device component or the display device using it, it can be restored by the elastic force of rubber. As a result, the impact resistance and bending resistance of the display device component and the display device using it can be improved.

[0045] Furthermore, when the display device component of this disclosure includes multiple shock-absorbing layers, it is preferable that at least one shock-absorbing layer satisfies conditions 1 and 2.

[0046] Furthermore, a preferred embodiment of the display device member of this disclosure is a display device member comprising a shock-absorbing layer and a protective layer laminated together, wherein the shock-absorbing layer satisfies conditions 1 and 2. Condition 1: The tensile yield strain of the shock-absorbing layer at 25°C, as described in JIS K7161 (2014), is 20% or more. Condition 2: The elastic limit strain of the shock-absorbing layer at 25°C is 20% or more. Similarly, the preferred range for the tensile yield strain of the shock-absorbing layer at 25°C is 20% or more, but more preferably 50% or more.

[0047] A tensile yield strain of 20% or more at 25°C in the shock-absorbing layer is preferable because it improves the recovery after deformation, thereby improving the shock resistance of the display device component and the display device using it. The higher the tensile yield strain, the better the above effect.

[0048] To achieve the tensile yield strain of the shock-absorbing layer at 25°C within the aforementioned range, this can be achieved, for example, by selecting a specific resin, as described later, for the resin constituting the shock-absorbing layer. The preferred range for the elastic limit strain of the shock-absorbing layer at 25°C is 20% or more, but more preferably 50% or more.

[0049] A shock-absorbing layer with an elastic limit strain of 20% or more at 25°C is preferable because it improves the recovery after deformation, thereby improving the shock resistance and bending resistance of the display device. The higher the elastic limit strain, the greater the aforementioned effect.

[0050] To set the elastic limit strain of the shock-absorbing layer at 25°C within the aforementioned range, this can be achieved, for example, by selecting a specific resin, as described later, for the resin constituting the shock-absorbing layer.

[0051] Furthermore, when the display device component of this disclosure includes multiple shock-absorbing layers, it is preferable that at least one shock-absorbing layer satisfies conditions 1 and 2.

[0052] Furthermore, in a display device member comprising a shock-absorbing layer and a protective layer laminated together, where the shock-absorbing layer satisfies condition 1, it is preferable that the shock-absorbing layer is laminated on one side of the protective layer, or that the shock-absorbing layer is laminated on both sides of the protective layer. The shock-absorbing layer and the protective layer may be laminated directly together, or they may be laminated via other layers such as an adhesive layer, bonding layer, or primer layer. The display device member of this disclosure exhibits impact resistance by having the shock-absorbing layer laminated on one side of the protective layer, but it can exhibit the same effect even if the shock-absorbing layer is laminated on both sides of the protective layer. Moreover, lamination on both sides may exhibit higher impact resistance than lamination on one side, making it more preferable.

[0053] Figure 1 shows a cross-sectional view of an example of a display device member 1 in which an impact-absorbing layer 2 is laminated on one side of a protective layer 3. Figure 2 shows a cross-sectional view of an example of a display device member 1 in which an impact-absorbing layer 2 is laminated on both sides of a protective layer 3. Figure 3 shows a cross-sectional view of an example of a display device member 1 in which an impact-absorbing layer 2 is laminated on one side of a protective layer 3 via an adhesive layer 4. Figure 4 shows a cross-sectional view of an example of a display device member 1 in which an impact-absorbing layer 2 is laminated on both sides of a protective layer 3 via an adhesive layer 4. Figure 5 shows a cross-sectional view of an example of a display device member 1 in which an impact-absorbing layer 2 is laminated on both sides of a protective layer 3, with one of these layers laminated via an adhesive layer 4.

[0054] Furthermore, the display device component of this disclosure preferably satisfies the following conditions 3 and 4. Condition 3: The glass transition temperature in the dynamic viscoelasticity test of the impact absorption layer is between -40°C and 30°C. Condition 4: The loss tangent at the glass transition temperature in the dynamic viscoelasticity test of the impact absorption layer is 0.5 or greater.

[0055] The glass transition temperature and the method for measuring the loss tangent at the glass transition temperature will be described later.

[0056] The preferred range for the glass transition temperature of the shock-absorbing layer is -40°C to 30°C, more preferably -40°C to 10°C, and particularly preferably -40°C to 0°C.

[0057] A glass transition temperature of -40°C to 30°C in the dynamic viscoelasticity test of the shock-absorbing layer is preferable because it improves the shock resistance of the display device.

[0058] The preferred range for the loss loss tangent at the glass transition temperature of the shock-absorbing layer is 0.5 or higher, more preferably 0.7 or higher, and particularly preferably 0.9 or higher.

[0059] A loss loss tangent of 0.5 or higher at the glass transition temperature of the shock-absorbing layer is preferable because it improves the shock resistance of the display device. A higher loss loss tangent improves the aforementioned effect, but due to the properties of the constituent materials, the upper limit is generally considered to be around 2.0.

[0060] To set the glass transition temperature of the shock-absorbing layer and the loss loss tangent at the glass transition temperature within the aforementioned range, this can be achieved, for example, by selecting a specific resin for the shock-absorbing layer, as described later.

[0061] The inventors focused on the rheological properties of the shock-absorbing layer and conducted an investigation. As a result, they found that when the glass transition temperature of the shock-absorbing layer is within a certain range and the loss tangent at that glass transition temperature is sufficiently high, the impact resistance of the display device component is significantly improved.

[0062] Loss tangent is one of the rheological properties, and generally, the higher it is, the more mechanical energy such as impact is converted into heat, which is thought to contribute to improved impact resistance. There are various types of loads on display device components and the displays that use them, such as high-speed loads like collisions and low-speed loads like indentations. Here, it is known that the temperature-velocity conversion law holds true for resin materials under certain conditions, and in this case, the difference between low speed and high speed correlates with the difference between high and low temperature. Therefore, the inventors focused on the speed of the load applied to the display device component and the displays that use it, and after organizing the relationship between that speed and temperature, they found that the impact absorption layer has a glass transition temperature in a certain temperature range, and that it is important to increase the loss tangent at that glass transition temperature. This is thought to be because the glass transition temperature in a specific range corresponds to a load of a specific speed, and by increasing the loss tangent according to the load applied to the display device component and the displays that use it, impact resistance is significantly improved.

[0063] Furthermore, when the display device component of this disclosure includes multiple shock-absorbing layers, it is preferable that at least one shock-absorbing layer satisfies conditions 3 and 4.

[0064] Furthermore, the display device component of this disclosure preferably satisfies the following condition 5.

[0065] Condition 5: The tensile hysteresis loss of the shock-absorbing layer at 25°C and 20% strain as defined in JIS K7312 (1996) is less than 10%.

[0066] The method for measuring tensile hysteresis loss will be described later.

[0067] The preferred range for the tensile hysteresis loss of the shock-absorbing layer at 25°C and 20% strain is less than 10%, more preferably less than 8%, and particularly preferably less than 5%. A tensile hysteresis loss of less than 10% at 25°C and 20% strain of the shock-absorbing layer is preferable because it improves the recovery of the display device component and the display device using it after they are subjected to load and deformation, thereby improving the impact resistance and bending resistance of the display device component and the display device using it. The lower the tensile hysteresis loss, the better, but the lower limit is theoretically 0%.

[0068] To achieve the aforementioned range for the tensile hysteresis loss at 20% strain in the shock-absorbing layer at 25°C, this can be achieved, for example, by selecting a specific resin, as described later, for the resin constituting the shock-absorbing layer.

[0069] The inventors focused on the mechanical properties of the shock-absorbing layer and further investigated its properties in a certain large deformation region, as described above. As a result, they found that the lower the tensile hysteresis loss of the shock-absorbing layer, the better the shock resistance and bending resistance of the display device component and the display device using it.

[0070] Tensile hysteresis loss represents how much energy is lost when a material deforms and then recovers. When focusing solely on material rheological properties, the important factor is how much of the energy a material converts into heat when it undergoes deformation. However, by improving tensile hysteresis loss, which is a characteristic in a certain large deformation region, deformations that have occurred can be recovered with greater precision. As a result, it is thought that this contributes to improving the impact resistance and bending resistance of display device components and the displays that use them.

[0071] Furthermore, when the display device component of this disclosure includes multiple shock-absorbing layers, it is preferable that at least one of the shock-absorbing layers satisfies condition 5.

[0072] Furthermore, the display device component of this disclosure preferably satisfies the following conditions 6 and 7. Condition 6: The modulus of elasticity of the shock-absorbing layer at 25°C, as described in JIS K7312 (1996), is 1 MPa or more and 1,000 MPa or less. Condition 7: The elongation at break of the shock-absorbing layer at 25°C, as described in JIS K7312 (1996), is 50% or more.

[0073] The methods for measuring the modulus of elasticity and elongation at break will be described later.

[0074] The preferred range for the elastic modulus of the shock-absorbing layer at 25°C is 1 MPa to 1,000 MPa, more preferably 1 MPa to 100 MPa, and particularly preferably 1 MPa to 10 MPa.

[0075] It is preferable that the elastic modulus of the shock-absorbing layer at 25°C is 1,000 MPa or less, as this improves the impact resistance and bending resistance of the display device component and the display device using it.

[0076] The preferred range for the elongation at break of the impact-absorbing layer at 25°C is 50% or more, more preferably 70% or more, and particularly preferably 80% or more. A elongation at break of 100% or more of the impact-absorbing layer at 25°C is preferable because it improves the impact resistance and bending resistance of the display device component and the display device using it. While a higher elongation at break is preferable, due to the properties of the constituent materials, the upper limit is generally considered to be around 1,000%.

[0077] To set the elastic modulus and elongation at break of the display device component and the display device using it within the aforementioned range, this can be achieved, for example, by selecting a specific resin, as described later, for the resin constituting the shock-absorbing layer. The inventors investigated the relationship between the mechanical properties of the shock-absorbing layer and the impact resistance and flexural resistance of the display device component and the display device using it. As a result, they found that impact resistance improves when the elastic modulus of the shock-absorbing layer is within a certain range, and flexural resistance improves when the elongation at break is above a certain level.

[0078] If the elastic modulus of the shock-absorbing layer is extremely low, even if it efficiently converts the load on the display device component or the display device using it into heat to exhibit shock absorption, the low elastic modulus will leave significant deformation. In this case, since even slight deformation can be seen by people in products such as displays, the shock resistance is considered insufficient. Therefore, it is considered that shock resistance is improved when the elastic modulus of the shock-absorbing layer is above a certain level. On the other hand, if the elastic modulus is too high, the loss tangent and tensile hysteresis loss may be insufficient, and it is considered that shock resistance is significantly improved when the elastic modulus is within a certain range.

[0079] Regarding elongation at break, flexible displays are subjected to significant deformation loads, especially during bending. In multi-layer laminated structures like displays, the load on each layer is expected to be unexpectedly large. Therefore, it is believed that increasing the elongation at break in shock-absorbing layers used in display device components and display devices using them will improve bending resistance.

[0080] Furthermore, when the display device component of this disclosure includes multiple shock-absorbing layers, it is preferable that at least one shock-absorbing layer satisfies conditions 6 and 7.

[0081] Furthermore, the display device component of this disclosure has a protective layer (surface protective layer) on the outermost surface on the viewing side, and has the surface protective layer, the shock absorbing layer, and the protective layer in that order, and the surface protective layer and at least one layer of the shock absorbing layer are directly laminated, and the thickness T of the surface protective layer １ The thickness T of the shock-absorbing layer ２ However, it is preferable that Equation 1 is satisfied. Equation 1: 0.4 ≤ T １ / (T １ +T ２ ) ≤ 0.8

[0082] The thickness T of the surface protective layer １ and the thickness T of the shock-absorbing layer ２ The preferred range for this relationship is "0.4 ≤ T １ / (T １ +T ２ ) ≤ 0.8, but more preferably 0.4 ≤ T １ / (T １ +T ２ ) ≤ 0.6.

[0083] The thickness T of the surface protective layer １ and the thickness T of the shock-absorbing layer ２ The relationship is "0.4 ≤ T １ / (T １ +T ２ Satisfying the condition ≤ 0.8 is preferable because it improves the impact resistance of the display device component and the display device using it. Thickness T of the surface protective layer １ and the thickness T of the shock-absorbing layer ２ To achieve the aforementioned relationship, it is possible, for example, by changing the thickness of the surface protective layer or the thickness of the impact absorbing layer.

[0084] The protective layer on the outermost surface of the viewing side is referred to as the surface protective layer. When the display device component of this disclosure has multiple shock-absorbing layers, the thickness T of at least one shock-absorbing layer is... ２ It is preferable that the above formula 1 is satisfied.

[0085] In verifying the impact resistance of display device components and display devices using them, the inventors investigated the relationship between the thicknesses of each layer constituting the display device component. As a result, they found that impact resistance significantly improves when the ratio of the thickness of the surface protection layer to the impact absorption layer is in a constant relationship. The surface protection layer is required to have impact resistance, scratch resistance, and other functions in addition to the impact resistance required for display devices, and a hard material is considered suitable for the impact absorption layer. In that case, since a relatively hard surface protection layer and a relatively soft impact absorption layer are laminated, it is thought that the thickness ratio, in addition to the mechanical strength of each layer, greatly affects the characteristics of the entire laminated structure, one of which is impact resistance. Therefore, the inventors investigated this thickness ratio in detail and found that T １ and T ２ It was found that impact resistance improves when the aforementioned range is met. This is thought to be because the hard surface protective layer suppresses deformation due to load, while the soft impact-absorbing layer converts the energy of that deformation into heat and restores the deformation that occurred, resulting in impact resistance throughout the entire laminated structure.

[0086] While the protective layer is a concept that encompasses the surface protective layer, for convenience, the terms "protective layer" and "surface protective layer" are sometimes used together.

[0087] Figure 6 shows a cross-sectional view of an example of a display device component 1 having a surface protection layer 5, an adhesive layer 4, an impact absorption layer 2, another adhesive layer 4, and a protective layer 3 in that order. Figure 7 shows a cross-sectional view of an example of a display device component 1 having a surface protection layer 5, an impact absorption layer 2, an adhesive layer 4, and a protective layer 3 in that order. Figure 8 shows a cross-sectional view of an example of a display device component 1 having a surface protection layer 5, an adhesive layer 4, an impact absorption layer 2, and a protective layer 3 in that order. Figure 9 shows a cross-sectional view of an example of a display device component 1 having a surface protection layer 5, an adhesive layer 4, a protective layer 3, and an impact absorption layer 2 in that order.

[0088] Furthermore, the display device component of the present disclosure preferably includes segments of the following chemical formulas 1 to 3 in its shock-absorbing layer.

[0089]

[0090]

[0091]

[0092] R １ R refers to a hydrogen or methyl group. ２ This refers to any of the following: A substituted or unsubstituted alkylene group A substituted or unsubstituted arylene group An alkylene group having an ether group, ester group, or amide group inside An arylene group having an ether group, ester group, or amide group inside An unsubstituted alkylene group having an ether group, ester group, or amide group inside An unsubstituted arylene group having an ether group, ester group, or amide group inside R ３ This refers to one of the following: a substituted or unsubstituted alkylene group or a substituted or unsubstituted arylene group. ４n is an integer greater than or equal to 2, where n is one of the following: a substituted or unsubstituted alkylene group; an alkylene group having an ether group or an ester group inside; an unsubstituted alkylene group having an ether group or an ester group inside; or an unsubstituted arylene group having an ether group or an ester group inside.

[0093] Here, the segment of chemical formula 1 refers to the (meth)acrylate group (after reaction) obtained by crosslinking the (meth)acrylate group. The presence of the (meth)acrylate group (after reaction) obtained by crosslinking the (meth)acrylate group in the shock-absorbing layer is preferable because it improves impact resistance and flexibility. Furthermore, it is preferable because it improves heat resistance, thus improving processing at high temperatures and stability in high-temperature environments.

[0094] The segment in chemical formula 2 refers to the diurethane group (after reaction). The presence of the diurethane group (after reaction) in the shock-absorbing layer is preferable because it improves impact resistance and flexibility.

[0095] The segment in chemical formula 3 refers to a polyether group. The presence of a polyether group in the impact-absorbing layer is preferable because it improves impact resistance and flexibility.

[0096] It is preferable that the impact-absorbing layer contains 10% to 100% by mass of a resin having segments of chemical formula 1, chemical formula 2, and chemical formula 3 in 100% by mass. This is preferable because it can improve the impact resistance and bending resistance of the display device component and the display device using it.

[0097] Furthermore, when the display device component of this disclosure includes a plurality of shock-absorbing layers, it is preferable that at least one of the shock-absorbing layers includes segments of chemical formulas 1 to 3.

[0098] Furthermore, the display device component of the present disclosure preferably includes a segment of the following chemical formula 4 in the shock-absorbing layer.

[0099]

[0100] R ５ , R ６and R ７ This refers to one of the following. Note that R ５ , R ６ and R ７ These may be the same or different. Substituted or unsubstituted alkylene group Substituted or unsubstituted arylene group

[0101] The segment in chemical formula 4 refers to an adduct branch. The presence of an adduct branch in the impact-absorbing layer is preferable because it improves impact resistance and bending resistance.

[0102] It is preferable that the impact-absorbing layer contains 10% to 100% by mass of a resin having segments of chemical formula 4 in 100% by mass. This is preferable because it can improve the impact resistance and bending resistance of the display device component and the display device using it.

[0103] Furthermore, when the display device component of this disclosure includes a plurality of shock-absorbing layers, it is preferable that at least one of the shock-absorbing layers includes a segment of chemical formula 4.

[0104] Furthermore, the telechelic polymer preferably contains segments of chemical formula 5 at its ends, and more preferably contains segments of chemical formula 6.

[0105]

[0106] Here, the R of the segment in chemical formula 5 ８ R refers to a hydrogen or methyl group. ９ This refers to any of the following: - A substituted or unsubstituted alkylene group - A substituted or unsubstituted arylene group - An alkylene group having an ether, ester, or amide group internally - An arylene group having an ether, ester, or amide group internally - An unsubstituted alkylene group having an ether, ester, or amide group internally - An unsubstituted arylene group having an ether, ester, or amide group internally Furthermore, R １０ This refers to one of the following: - A substituted or unsubstituted alkylene group - A substituted or unsubstituted arylene group

[0107]

[0108] Here, the R segment of chemical formula 6 １１ R refers to a hydrogen or methyl group. １２ and R １３ refers to one of the following, where n is an integer greater than or equal to 2. Note that R １２ and R １３ These may be the same or different. • A substituted or unsubstituted alkylene group, • A substituted or unsubstituted arylene group, • An alkylene group having an ether, ester, or amide group internally, • An arylene group having an ether, ester, or amide group internally, • An unsubstituted alkylene group having an ether, ester, or amide group internally, • An unsubstituted arylene group having an ether, ester, or amide group internally. Furthermore, R １４ This refers to either: a substituted or unsubstituted alkylene group, or a substituted or unsubstituted arylene group.

[0109] The fact that the shock-absorbing layer of this disclosure contains segments of chemical formulas 1 to 4, and that the reaction products of the telechelic polymer contain segments of chemical formulas 5 and 6, can be determined by various analytical methods, but the method using pyrolysis GC-MS is simple. It can also be determined from the raw materials that form the shock-absorbing layer.

[0110] One aspect of this disclosure is a film for a display device component used in the shock-absorbing layer of a display device component comprising a laminated shock-absorbing layer and a protective layer, wherein the tensile yield strain at 25°C as described in JIS K7161 (2014) is 20% or more.

[0111] The preferred range for the tensile yield strain of a film for display device components at 25°C is 20% or more, but more preferably 50% or more. A tensile yield strain of 20% or more at 25°C is preferable because it improves the recovery after deformation, thereby improving the impact resistance and bending resistance of the display device component and the display device using it. The higher the tensile yield strain, the better the above effect. To set the tensile yield strain of the impact absorbing layer at 25°C within the above range, this can be achieved, for example, by selecting a specific resin, as described later, for the resin constituting the impact absorbing layer.

[0112] The characteristics and effects of tensile yield strain are as described above.

[0113] The preferred range for the elastic limit strain of a film for display device components at 25°C is 20% or more, but more preferably 50% or more.

[0114] A film for display device components with an elastic limit strain of 20% or more at 25°C is preferable because it improves the recovery after deformation, thereby improving the impact resistance and bending resistance of the display device. The higher the elastic limit strain, the greater the aforementioned effect.

[0115] To set the elastic limit strain of the film for display device components at 25°C within the aforementioned range, this can be achieved, for example, by selecting a specific resin, as described later, for the resin constituting the shock-absorbing layer.

[0116] Furthermore, the film for display device components of this disclosure preferably contains a reaction product of a telechelic polymer having 3.0 to 5.0 reactive functional groups per molecule and a weight-average molecular weight of 2,000 or more.

[0117] It is preferable that the film for the display device component contains a reaction product of a telechelic polymer having 3.0 to 5.0 reactive functional groups per molecule and a weight-average molecular weight of 2,000 or more, as this improves resilience and tensile yield strain, and suppresses tensile hysteresis loss, thereby improving the impact resistance and flexural resistance of the display device incorporating the film for the display device component. If the number of reactive functional groups per molecule or the weight-average molecular weight does not meet the above range, or if the film does not contain a reaction product of a telechelic polymer, the impact resistance and flexural resistance of the display device may be insufficient when the display device undergoes significant deformation under severe load.

[0118] The properties and effects of telechelic polymers are as described above.

[0119] [Laminated Structure of Display Device Component] The display device component of this disclosure comprises a shock-absorbing layer and a protective layer laminated together. The display device component may also have layers other than the shock-absorbing layer and the protective layer laminated together. Furthermore, the display device component may have a protective layer on the outermost surface on the viewing side (a protective layer on the outermost surface on the viewing side may be called a surface protective layer). The shock-absorbing layer may be laminated on one side of the protective layer, or on both sides of the protective layer.

[0120] The shock-absorbing layer and the protective layer may be directly laminated together, or they may be laminated together via other layers such as an adhesive layer, bonding layer, or primer layer.

[0121] The surface protection layer may be directly laminated with the shock-absorbing layer and the protective layer, or it may be laminated via other layers such as an adhesive layer, bonding layer, or primer layer. Direct lamination of the surface protection layer and the shock-absorbing layer is more preferable. Furthermore, a preferred configuration is one in which the surface protection layer, shock-absorbing layer, and protective layer are laminated in that order.

[0122] [Protective Layer (Surface Protective Layer)] Examples of materials for the protective layer or surface protective layer in the display device component of this disclosure include acrylic resin, methacrylic resin, polycarbonate resin, polyamide resin, polyimide resin, transparent polyimide resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polycyclic olefin resin, thermoplastic polyurethane resin, silicone resin, and glass.

[0123] Preferred materials for the protective layer or surface protective layer of this disclosure include polyimide resin, polyethylene terephthalate resin, and glass.

[0124] When glass is used for the protective layer or surface protective layer in this disclosure, chemically strengthened glass is preferred. Because chemically strengthened glass has excellent strength, it can achieve high strength even with a thinner film.

[0125] The thickness of the protective layer or surface protective layer of this disclosure is not particularly limited, but is preferably 300 μm or less, more preferably 100 μm or less, and particularly preferably 80 μm or less.

[0126] Furthermore, the protective layer and surface protective layer may contain various additives, such as antioxidants, antistatic agents, nucleating agents, inorganic particles, organic particles, viscosity reducers, heat stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, and doping agents for refractive index adjustment.

[0127] Furthermore, the protective layer and surface protective layer may be in a single-layer or laminated configuration. In addition, functional layers such as an easy-adhesion layer, an antistatic layer, an undercoat layer, or an ultraviolet-absorbing layer may be pre-applied to the surface of the protective layer and surface protective layer, separate from the impact-absorbing layer of this disclosure.

[0128] Various surface treatments can be applied to the surface of protective layers and surface protection layers. Examples of surface treatments include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high-frequency treatment, glow discharge treatment, activated plasma treatment, laser treatment, sandblasting treatment, mixed acid treatment, and ozone oxidation treatment.

[0129] Examples of protective layers and surface protective layers include Toray Industries, Inc.'s "Lumirror" (registered trademark), Toyobo Co., Ltd.'s "Cosmoshine" (registered trademark), "Toyobo Ester" (registered trademark) film, and "Teonex" (registered trademark), Mitsubishi Chemical Corporation's "Diafoil" (registered trademark), Unitika Ltd.'s "Emblet" (registered trademark) and "Emblem" (registered trademark), Kolon Industries' transparent polyimide film products, SK Microworks Solutions' transparent polyimide film, Sumitomo Chemical Co., Ltd.'s transparent polyimide film, Mitsubishi Gas Chemical Company, Inc.'s "Neoprim" (registered trademark), Kaneka Corporation's transparent polyimide film, UBE Corporation's "Upirex" (registered trademark), I.S.T. Corporation's "Tohmed" (registered trademark), AGC Inc.'s "Dragontrail" (registered trademark), Corning's "Gorilla Glass" (registered trademark), and Schott's "SHOTT UTG" (registered trademark), and these products can also be used.

[0130] [Impact-absorbing layer] In addition to impact resistance and flexibility, the impact-absorbing layer in the display device component of this disclosure may have other functions such as moldability, designability, scratch resistance, stain resistance, anti-reflective properties, anti-static properties, conductivity, heat reflection, near-infrared absorption, and electromagnetic wave shielding, and in such cases, one or more layers may be formed. For example, a functional layer having the above-mentioned functions, an adhesive layer, an electronic circuit layer, a printed layer, an optical adjustment layer, and other functional layers may be provided.

[0131] There are no particular limitations on the thickness of the impact-absorbing layer in this disclosure, and it can be appropriately selected depending on the application. The lower limit of the thickness of the impact-absorbing layer cannot be determined in general terms, as it is affected by the elastic modulus of the impact-absorbing layer itself, the elongation at break, the peel force from the laminate, and the peel angle. However, when achieving physical properties equivalent to those of a general flexible material using the laminate manufacturing method described later, the lower limit is approximately 1 μm.

[0132] [Method for manufacturing a display device component and shock-absorbing layer] The method for manufacturing a display device component according to this disclosure is not particularly limited, but the shock-absorbing layer may be directly laminated onto a protective layer or surface protective layer by a method such as coating, or the shock-absorbing layer may be formed on a support substrate, the support substrate may be peeled off, and the shock-absorbing layer may be laminated onto the protective layer or surface protective layer via an adhesive layer or the like, or the shock-absorbing layer may be formed on a support substrate, the shock-absorbing layer may be laminated onto the protective layer or surface protective layer via an adhesive layer or the like, and then the support substrate may be peeled off.

[0133] Figure 11 shows a cross-sectional view of an example of an impact-absorbing layer 2 using a support substrate 21.

[0134] The method for manufacturing the shock-absorbing layer of this disclosure is not particularly limited, but preferably involves applying a coating composition containing a resin component to a protective layer, a surface protective layer, or a support substrate to form a coating layer (step 1), then removing the solvent from the coating layer and drying it (step 2), and irradiating it with active energy rays to crosslink the resin precursor (step 3). Furthermore, when a support substrate is used, it is preferable to peel the support substrate from the shock-absorbing layer (step 4).

[0135] Furthermore, it is preferable to perform the following steps in order after "Step 3": applying a coating composition for a particle layer containing particles and resin components to form a coating layer, and removing the solvent from the coating layer; or, after "Step 3", applying a coating composition for a particle layer containing particles and resin precursors to form a coating layer, removing the solvent from the coating layer, and irradiating with active energy rays to crosslink the resin precursor and form a laminate having an impact-absorbing layer on a support substrate.

[0136] Furthermore, if a support substrate having a surface shape such as an uneven shape is used as the aforementioned support substrate, it is possible to form a surface shape on the surface of the shock-absorbing layer by transferring the surface shape such as the uneven shape of the support substrate to the surface of the shock-absorbing layer that was in contact with the support substrate in "Step 4" above. At this time, an inversion occurs between the surface shape of the support substrate and the surface shape of the shock-absorbing layer.

[0137] The method for applying the coating composition to the protective layer, surface protective layer, or support substrate in step 1 is not particularly limited, as long as the coating composition is applied to the protective layer, surface protective layer, or support substrate and a uniform coating layer is formed within the surface. The coating method on the support substrate can be appropriately selected from methods such as dip coating, roller coating, wire bar coating, gravure coating, or die coating (U.S. Patent No. 2,681,294). Here, the coating layer refers to the "liquid layer" formed by the coating process.

[0138] The method for removing the solvent in step 2, i.e., the drying method, is not particularly limited as long as it can remove the solvent from the protective layer, surface protective layer, and coating layer formed on the support substrate. Examples of drying methods include heat transfer drying (adhesion to a high-temperature object), convection heat transfer (hot air), radiant heat transfer (infrared rays), and others (microwaves, induction heating). Among these, in the manufacturing method of this disclosure, a method using convection heat transfer or radiant heat transfer is preferred because it is necessary to make the drying speed uniform in the width direction with precision.

[0139] The crosslinking method in step 3 involves irradiating the coated layer, from which the solvent has been removed after drying, with active energy rays to induce a reaction and crosslink the coating film.

[0140] For crosslinking using active energy rays, electron beams (EB) and / or ultraviolet (UV) rays are preferred for versatility. Examples of UV lamps used for irradiation include discharge lamps, flash lamps, laser lamps, and electrodeless lamps. When using a high-pressure mercury lamp (discharge lamp type) for UV curing, the UV irradiance should be 100 to 3,000 mW / cm². ２ ) is preferred, and more preferably 200 to 2,000 (mW / cm²). ２ ), more preferably 300 to 1,500 (mW / cm²). ２ UV irradiation is often performed under conditions where the cumulative amount of UV light is 100 to 3,000 (mJ / cm²). ２ ) is preferred, and more preferably 200 to 2,000 (mJ / cm²). ２ ), more preferably 300 to 1,500 (mJ / cm²). ２ It is preferable to perform ultraviolet irradiation under the following conditions. Here, ultraviolet irradiance is the irradiation intensity received per unit area, and it varies depending on the lamp output, emission spectral efficiency, diameter of the light bulb, design of the reflector, and distance from the light source to the irradiated object. However, the irradiance does not change with the transport speed. In addition, the integrated ultraviolet light quantity is the irradiation energy received per unit area, and it is the total amount of photons that reach the surface. The integrated light quantity is inversely proportional to the irradiation speed passing under the light source and is proportional to the number of irradiations and the number of lamps.

[0141] [Paint Composition] The "paint composition" used in the above-described method for manufacturing the shock-absorbing layer is not particularly limited as long as it can be applied uniformly in-plane on a protective layer, surface protective layer, or support substrate and form an shock-absorbing layer exhibiting the characteristics of this disclosure, but it is preferable that it is a paint composition containing a telechelic polymer. The paint composition may contain solid components other than the telechelic polymer, but it is preferable that the content of such components is less than 10% by volume relative to the solid components. Examples of solid components other than the telechelic polymer include monomers, prepolymers, and polymer components that are different from the main component, the telechelic polymer. The method for controlling the number of functional groups and molecular weight of the telechelic polymer varies depending on the type of polymer and is therefore not particularly limited, but in the case of the telechelic polymer described in the examples and comparative examples of this disclosure described later, it can be controlled by appropriately selecting the number of functional groups and molecular weight of the polyol or polyisocyanate used during synthesis and optimizing the polymerization conditions.

[0142] [Solvent] The paint composition used in the above-described method for manufacturing the shock-absorbing layer may contain a solvent, and it is preferable to include a solvent in order to uniformly form the coated layer within the surface. Preferably, the number of solvent types is 1 to 20, more preferably 1 to 10, even more preferably 1 to 6, and particularly preferably 1 to 4.

[0143] Here, "solvent" refers to a substance that is liquid at room temperature and pressure and can be almost entirely evaporated during the drying process described above.

[0144] Here, the type of solvent is determined by the molecular structure that constitutes the solvent. That is, even if they have the same elemental composition and the same type and number of functional groups, those with different bonding relationships (structural isomers), and those that are not structural isomers but cannot perfectly overlap in any conformation in three-dimensional space (stereoisomers), are treated as different types of solvents. For example, 2-propanol and n-propanol are treated as different solvents. The aforementioned solvents are not particularly limited, but examples include ketone solvents, alcohol solvents, aromatic hydrocarbon solvents, ester solvents, ether solvents, glycol ether solvents, and aliphatic hydrocarbon solvents. Specifically, examples include, but are not limited to, methyl ethyl ketone, methyl isobutyl ketone, acetone, cyclohexanone, methanol, ethanol, isopropyl alcohol, n-propanol, n-butanol, toluene, xylene, ethylbenzene, ethyl acetate, butyl acetate, isobutyl acetate, tetrahydrofuran, diethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether, n-hexane, n-heptane, and isoparaffinic solvents. Furthermore, if a solvent with a low relative evaporation rate is included, it is preferable that the solvent exhibits the following properties.

[0145] Characteristic 1: When solvent B is defined as the solvent with the lowest relative evaporation rate relative to n-butyl acetate (ASTM D3539-87 (2004)), the relative evaporation rate of solvent B is 0.4 or less.

[0146] Here, the relative evaporation rate relative to the solvent n-butyl acetate is the evaporation rate measured in accordance with ASTM D3539-87 (2004). Specifically, it is defined as the relative value of the evaporation rate relative to the time required for 90% by mass of n-butyl acetate to evaporate under dry air.

[0147] The lower limit of the relative evaporation rate of the solvent with a low relative evaporation rate is acceptable as long as the solvent can evaporate and be removed from the coating film during the drying process. In a typical coating process, a relative evaporation rate of 0.005 or higher is sufficient. Examples of solvents with low relative evaporation rates include isobutyl ketone (relative evaporation rate: 0.2), isophorone (relative evaporation rate: 0.026), diethylene glycol monobutyl ether (relative evaporation rate: 0.004), diacetone alcohol (relative evaporation rate: 0.15), oleyl alcohol (relative evaporation rate: 0.003), ethylene glycol monoethyl ether acetate (relative evaporation rate: 0.2), nonylphenoxyethanol (relative evaporation rate: 0.25), propylene glycol monoethyl ether (relative evaporation rate: 0.1), and cyclohexanone (relative evaporation rate: 0.32).

[0148] [Other components in the paint composition] The paint composition used in the above-described method for manufacturing the shock-absorbing layer preferably contains antioxidants, polymerization initiators, curing agents, and catalysts. Polymerization initiators and catalysts are used to promote crosslinking of the resin film. The polymerization initiator is preferably one that can initiate or promote polymerization, condensation, or crosslinking reactions of the components contained in the paint composition by anionic, cationic, or radical polymerization reactions.

[0149] Antioxidants are broadly classified into radical chain initiation inhibitors, radical scavengers, and peroxide decomposers based on their mechanism of action. Radical scavengers or peroxide decomposers are more preferred, with hindered phenol-based, semi-hindered phenol-based radical scavengers, or phosphite-based and thioether-based peroxide decomposers being particularly preferred.

[0150] Various polymerization initiators, curing agents, and catalysts can be used. Furthermore, polymerization initiators, curing agents, and catalysts may be used individually, or multiple polymerization initiators, curing agents, and catalysts may be used simultaneously. Acidic catalysts and thermal polymerization initiators may also be used in combination. Examples of acidic catalysts include aqueous hydrochloric acid, formic acid, and acetic acid. Examples of thermal polymerization initiators include peroxides and azo compounds. Examples of photopolymerization initiators include alkylphenone compounds, sulfur-containing compounds, acylphosphine oxide compounds, and amine compounds. Examples of crosslinking catalysts that promote the formation of urethane bonds include dibutyltin dilaurate and dibutyltin diethylhexoate.

[0151] Alkylphenone compounds are preferred as photopolymerization initiators from the viewpoint of curability. Specific examples of alkylphenone compounds include 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-phenyl)-1-butane, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-(4-phenyl)-1-butane, and 2-benzyl-2-dimethylamino-1-(4- Examples include morpholinophenyl)-1-butane, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butane, 1-cyclohexylphenyl ketone, 2-methyl-1-phenylpropan-1-one, 1-[4-(2-ethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, bis(2-phenyl-2-oxoacetic acid)oxybisethylene, and high molecular weight versions of these materials.

[0152] Furthermore, leveling agents, lubricants, antistatic agents, etc., may be added to the coating composition used to form the resin film, provided that they do not impair the effects of the present disclosure. As a result, the resin film can contain leveling agents, lubricants, antistatic agents, etc.

[0153] Examples of leveling agents include acrylic copolymers, silicone-based, and fluorine-based leveling agents. Examples of antistatic agents include metal salts such as lithium salts, sodium salts, potassium salts, rubidium salts, cesium salts, magnesium salts, and calcium salts.

[0154] [Supporting material] The supporting material used in the shock-absorbing layer described later may be a thermoplastic resin or a thermosetting resin, and may be a homopolymer, copolymer, or a blend of two or more types. The resin constituting the supporting material is preferably one with good moldability, and from this point of view, a thermoplastic resin is more preferred.

[0155] Examples of thermoplastic resins include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene; alicyclic polyolefin resins; polyamide resins such as nylon 6 and nylon 66; aramid resins; polyimide resins; polyester resins; polycarbonate resins; polyarylate resins; polyacetal resins; polyphenylene sulfide resins; fluororesins such as tetrafluoroethylene resin, trifluoroethylene resin, trifluoroethylene chloride resin, tetrafluoroethylene-hexafluoropropylene copolymer, and vinylidene fluoride resin; acrylic resins; methacrylic resins; polyacetal resins; polyglycolic acid resins; and polylactic acid resins.

[0156] Examples of thermosetting resins that can be used include phenolic resins, epoxy resins, urea resins, melamine resins, unsaturated polyester resins, polyurethane resins, polyimide resins, and silicone resins.

[0157] The thermoplastic resin is preferably one that has sufficient stretchability and conformability. From the viewpoint of strength, heat resistance, and transparency, the thermoplastic resin is more preferably polyester resin, polycarbonate resin, acrylic resin, or methacrylic resin.

[0158] In this disclosure, polyester resin is a general term for polymers having ester bonds as the main linkage chains in the main chain, and is obtained by polycondensation of an acid component and its ester with a diol component. Specific examples include polyethylene terephthalate, polypropylene terephthalate, polyethylene-2,6-naphthalate, and polybutylene terephthalate. These may also be copolymerized with other dicarboxylic acids and their esters or diol components as the acid and diol components. Among these, polyethylene terephthalate and polyethylene-2,6-naphthalate are particularly preferred in terms of transparency, dimensional stability, and heat resistance.

[0159] Furthermore, the supporting substrate may contain various additives, such as antioxidants, antistatic agents, nucleating agents, inorganic particles, organic particles, viscosity reducers, heat stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, and doping agents for refractive index adjustment.

[0160] Furthermore, the support substrate may be in a single-layer or multi-layer configuration.

[0161] Furthermore, the surface of the support substrate may be pre-filled with functional layers such as an easy-adhesion layer, an antistatic layer, an undercoat layer, an ultraviolet-absorbing layer, and a release layer, separate from the display device component and the film for the display device component of this disclosure. In this disclosure, it is preferable that the support substrate has a release layer in order to reduce the peeling force between the support substrate and the resin film. Details of the release layer will be described later.

[0162] Examples of supporting substrates include Toray Industries, Inc.'s "Lumirror" (registered trademark) and "Trefan," Toyobo Co., Ltd.'s "Cosmoshine" (registered trademark) and "Toyobo Ester" (registered trademark) films and "Teonex" (registered trademark), Mitsubishi Chemical Corporation's "Diafoil" (registered trademark), and Unitika Ltd.'s "Emblet" (registered trademark) and "Emblem" (registered trademark), and these products can also be used.

[0163] Examples of support substrates provided with release layers made of silicone-based or non-silicone-based materials (fluorine-based, alkyl-based, etc.) include "Therapyle" (registered trademark) from Toray Film Processing Co., Ltd., "Unipeel" (registered trademark) from Unitika Ltd., "Panapeel" (registered trademark) from Panac Co., Ltd., and "Cosmopeel" (registered trademark) and "Purex" (registered trademark) from Toyobo Co., Ltd., and these products can also be used.

[0164] The surface of the support substrate can be subjected to various surface treatments before the resin film is formed. Examples of surface treatments include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high-frequency treatment, glow discharge treatment, activated plasma treatment, laser treatment, sandblasting treatment, mixed acid treatment, and ozone oxidation treatment. Among these, glow discharge treatment, ultraviolet irradiation treatment, corona discharge treatment, and flame treatment are preferred, and glow discharge treatment and ultraviolet treatment are even more preferred.

[0165] The peeling force between the support substrate and the shock-absorbing layer is preferably 5 N / 50 mm or less. A support substrate having a peeling force of 5 N / 50 mm or less from the shock-absorbing layer will be referred to as a peelable support substrate below.

[0166] As described above, in the laminate of this disclosure, the peel force between the support substrate and the shock-absorbing layer is preferably 5 N / 50 mm or less, more preferably 1 N / 50 mm or less, and particularly preferably 800 mN / 50 mm or less. There is no particular lower limit to the peel force between the support substrate and the shock-absorbing layer, but if it is less than 1 mN / 50 mm, the support substrate and the shock-absorbing layer may peel off or lift during the manufacturing process, so it is preferable that the peel force between the support substrate and the shock-absorbing layer is 1 mN / 50 mm or more.

[0167] [Release Layer] The aforementioned support substrate preferably has a release layer. A support substrate having a release layer is also called a release film. The release layer may be composed of multiple layers from the viewpoint of providing adhesion, antistatic properties, solvent resistance, etc., and may be present on both sides of the support substrate.

[0168] The composition and thickness of the release layer are not particularly limited as long as the peeling force from the impact absorption layer can be kept within the preferred range described above. However, from the viewpoint of in-plane uniformity, quality, and peeling force of the release layer, it is preferably 10 nm to 500 nm, and more preferably 20 nm to 300 nm.

[0169] [Protective Material] The shock-absorbing layer may have a protective material on the side opposite to the protective layer, surface protective layer, or support substrate. The distinction between the protective material and the protective layer, surface protective layer, or support substrate is that the coating composition is applied to the protective layer, surface protective layer, or support substrate, while the material that is bonded after the shock-absorbing layer is formed is the protective material. The protective material may be the same as or different from the aforementioned protective layer, surface protective layer, or support substrate, but it is preferable that there is a difference in peel strength between the protective material and the aforementioned protective layer, surface protective layer, or support substrate in subsequent processes, and it is particularly preferable that the peel strength of the protective material is lower than that of the protective layer, surface protective layer, or support substrate. The relationship between the peel strength of the protective material and the protective layer, surface protective layer, or support substrate from the shock-absorbing layer is appropriately selected according to the method of use in subsequent processes. For this reason, the protective material may have a release layer, an adhesive layer, or be a single layer.

[0170] Figure 12 shows a cross-sectional view of an example of an impact-absorbing layer 2 having a protective material 22 on the side opposite to the support base material 21.

[0171] [Examples of Use] The display device components and films for display device components disclosed herein have excellent impact resistance and flexibility, and can be suitably used in a variety of applications.

[0172] For example, it can be used in display devices such as smartphones, flexible displays, liquid crystal displays, organic EL displays, micro-LED displays, mini-LED displays, foldable displays, rollable displays, slidable displays, stretchable displays, see-through displays, tablet devices, IT equipment, wearable devices, smartwatches, smart glasses, personal computers, handheld devices, AR headsets, VR headsets, MR headsets, televisions, digital signage, public information displays, in-vehicle displays, center information displays, and head-up displays.

[0173] In particular, it can be used as a component for display devices such as smartphones, flexible displays, foldable displays, rollable displays, slidable displays, stretchable displays, tablet terminals, and IT equipment.

[0174] Figure 10 shows a cross-sectional view of an example of a display device having a display device member 1 having a surface protective layer 5, an impact absorbing layer 2, an adhesive layer 4, and a protective layer 3 in that order, an adhesive layer 4, and an optical display 11.

[0175] Next, the present invention will be described based on examples, but the present invention is not necessarily limited to these. Unless otherwise specified below, "parts" refers to parts by mass, and "%" refers to mass percent.

[0176] [Telechelic Polymer] [Synthesis Example 1: Synthesis of Telechelic Polymer (TP-1)] In a four-necked flask equipped with a thermometer, condenser, and stirrer, 12.9 parts by mass of polycaprolactone triol (Daicel Corporation's "Praxel" (registered trademark) 312) and 52.1 parts by mass of polycaprolactone diol (Daicel Corporation's "Praxel" (registered trademark) L212AL) ​​were added as component A, and 30.8 parts by mass of allophanate-modified hexamethylene diisocyanate (Covestro AG's "Desmodur" (registered trademark) XP2580) and dibutylsulata laurate (Nitto Kasei Co., Ltd.) were added as component B. 0.03 parts by mass of "Neostan" (registered trademark) U-100 and 67 parts by mass of methyl isobutyl ketone (hereinafter referred to as MIBK) were charged, and the mixture was reacted for 5 hours while maintaining the internal temperature at 60°C and blowing in nitrogen. Subsequently, 4.3 parts by mass of 2-hydroxyethyl acrylate (HEA, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and 0.1 parts by mass of hydroquinone monomethyl ether were added as component C, and the mixture was reacted for 3 hours at the same temperature while blowing in air. After confirming that the isocyanate group content was 0.1% or less by the method of JIS K7301 (1995), a telechelic polymer solution (TP-1) with a weight-average molecular weight of 19,000 and 3.5 functional groups was obtained. The molecular weight of the telechelic polymer was measured using a GPC instrument HLC-8220 (manufactured by Tosoh Corporation).

[0177] [Synthesis Examples 2-5: Synthesis of Telechelic Polymers (TP-2) to (TP-5)] Telechelic polymer (TP-5) was obtained from (TP-2) using the same method as in Synthesis Example 1, except that the raw materials and amounts of charge shown in Table 1 were changed.

[0178]

[0179] The abbreviations in the table represent the following compounds. [Component A; Polyols, etc.] ・PL-312: Polycaprolactone triol, manufactured by Daicel Corporation, product name: "Praxel" (registered trademark) 312, hydroxyl value 136.1 mg KOH / g, number average molecular weight 1250 ・PL-L212AL: Polycaprolactone diol, manufactured by Daicel Corporation, product name: "Praxel" (registered trademark) L212AL, hydroxyl value 90.2 mg KOH / g, number average molecular weight 1250 ・PL-FA1: Lactone-modified acrylate, manufactured by Daicel Corporation, product name: "Praxel" (registered trademark) FA1, hydroxyl value 244 mg KOH / g ・BL-AE200: Terminal hydroxyl group polyalkylene glycol monoacrylate, manufactured by NOF Corporation, product name: "Bremmer" (registered trademark) AE200, molecular weight 270 • PL-410: Polycaprolactone tetraol, manufactured by Daicel Corporation, product name: "Praxel" (registered trademark) 410, hydroxyl value 217.8 mg KOH / g, number average molecular weight 1030 • PTMG-2000: Polytetramethylene glycol, manufactured by Mitsubishi Chemical Corporation, product name: PTMG2000, hydroxyl value 56 mg KOH / g, number average molecular weight 2000

[0180] [Component B; Isocyanates, etc.] ・DS-XP2580: Allophanate modified hexamethylene diisocyanate, manufactured by Covestro AG, product name: "Desmodur" (registered trademark) XP2580, isocyanate group content 12% by mass ・DS-I: Isophorone diisocyanate, manufactured by Covestro AG, product name: "Desmodur" (registered trademark) I, isocyanate group content 37.5% by mass ・DU-AE700-100: Adduct of hexamethylene diisocyanate, manufactured by Asahi Kasei Corporation, product name: "Duranate" (registered trademark) AE700-100, isocyanate group content 11.9% by mass DU-TPA100: Isocyanurate derivative of hexamethylene diisocyanate, manufactured by Asahi Kasei Corporation, product name: "Duranate" (registered trademark) TPA-100, isocyanate group content 23.1% by mass.

[0181] [Component C; Acrylate, etc.] • HEA: 2-Hydroxyethyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd., product name: HEA

[0182] [Other ingredients] ・DBTDL: Dibutylsulphurate, manufactured by Nitto Kasei Co., Ltd., product name: "Neostan" (registered trademark) U-100) ・MEHQ: Hydroquinone monomethyl ether ・MIBK: Methyl isobutyl ketone.

[0183] [Preparation of Paint Composition] [Paint Composition 1] Paint Composition 1 was obtained by uniformly mixing 167 parts by mass of the telechelic polymer solution (TP-1) obtained in Synthesis Example 1, 3.0 parts by mass of an α-hydroxyacetophenone-based photopolymerization initiator (product name: "Omnirad" (registered trademark) 184, manufactured by IGM Resins B.V.), 0.2 parts by mass of a non-silicone-based leveling agent (product name: BYK-3560, manufactured by BYK Additives & Instruments), and 36.5 parts by mass of a solvent (methyl isobutyl ketone).

[0184] [Paint Compositions 2-6] Paint compositions 2-6 were obtained in the same manner as in paint composition 1, except that the raw materials shown in Table 2 were changed.

[0185]

[0186] The abbreviations shown in the table refer to the following compounds: • HPNDA: Neopentyl glycol diacrylate hydroxypivalate, manufactured by MIWON, product name: "Miramer" (registered trademark) M210, molecular weight: 312 • O184: α-hydroxyacetophenone-based photopolymerization initiator, manufactured by IGM Resins B.V., product name: "Omnirad" (registered trademark) 184. • B3560: Non-silicone leveling agent, manufactured by BYK Additives & Instruments, product name BYK-3560 • MIBK: Methyl isobutyl ketone

[0187] [Supporting material] [Supporting material 1] As supporting material 1, a release-coated PET film "Therapyle" (registered trademark) SY (thickness 50 μm, manufactured by Toray Film Processing Co., Ltd.) was used.

[0188] [Protective layer] [Protective layer film 1] As protective layer film 1, PET film "Lumirror" (registered trademark) US20 (thickness 50 μm, manufactured by Toray Industries, Inc.) was used.

[0189] [PET Film] [PET Film 1] As PET Film 1, PET film "Lumirror" (registered trademark) S10 (thickness 50 μm, manufactured by Toray Industries, Inc.) was used.

[0190] [Preparation of Display Device Components] [Method 1 for Preparing Display Device Components] An impact-absorbing layer was formed on a support substrate by using the combination of the aforementioned paint composition and the resin layer formation method described later, as shown in Table 3.

[0191] [Step 1] In Step 1, the aforementioned paint composition was applied to the support substrate (or the side with the release layer if a release layer is present) using a continuous coating device with a slot die coater, adjusting the discharge flow rate so that the thickness of the impact absorption layer after crosslinking was as shown in Table 4, thereby forming a coated layer.

[0192] [Step 2] In Step 2, the coating layer formed in Step 1 was dried under the following conditions to remove the solvent. • Air temperature: 80°C. • Air velocity: Coating side: 5 m / sec, Opposite coating side: 5 m / sec. • Air direction: Coating side: Parallel to the substrate surface, Opposite coating side: Perpendicular to the substrate surface. • Residence time: 2 minutes.

[0193] [Step 3] In Step 3, the coating layer (uncrosslinked resin layer) obtained by removing the solvent was irradiated with active energy rays under the following conditions to crosslink it and obtain an impact-absorbing layer. • Irradiation light source: High-pressure mercury lamp. • Irradiation output: 400 mW / cm² ２ • Total luminous intensity: 120 mJ / cm ２ Oxygen concentration: 0.1% by volume.

[0194] [Step 4] In Step 4, an optical adhesive film is bonded to the side of the shock-absorbing layer opposite to the support substrate, the adhesive side of the optical adhesive film is bonded to the protective layer film 1, and the support substrate is peeled off from the shock-absorbing layer to create a display device component.

[0195] [Method for creating display device components 2] An impact-absorbing layer was formed on the protective layer film 1 using the combination of the aforementioned paint composition and the resin layer formation method described later, as shown in Table 3, to create a display device component.

[0196] [Step 1] In Step 1, the aforementioned coating composition was applied to the protective layer film 1 using a continuous coating device with a slot die coater, adjusting the discharge flow rate so that the thickness of the impact absorption layer after crosslinking would be the film thickness shown in Table 4, thereby forming a coated layer.

[0197] [Step 2] In Step 2, the coating layer formed in Step 1 was dried under the following conditions to remove the solvent. • Air temperature: 80°C. • Air velocity: Coating side: 5 m / sec, Opposite coating side: 5 m / sec. • Air direction: Coating side: Parallel to the substrate surface, Opposite coating side: Perpendicular to the substrate surface. • Residence time: 2 minutes.

[0198] [Step 3] In Step 3, the coating layer (uncrosslinked resin layer) obtained by removing the solvent was irradiated with active energy rays under the following conditions to crosslink it and obtain an impact-absorbing layer. • Irradiation light source: High-pressure mercury lamp. • Irradiation output: 400 mW / cm² ２ • Total luminous intensity: 120 mJ / cm ２ Oxygen concentration: 0.1% by volume.

[0199] The impact-absorbing layers prepared by the above method were used in the examples and comparative examples. In addition, PET film 1 was used as comparative example 3.

[0200]

[0201] [Evaluation of Display Device Components and Shock Absorbing Layer] The following performance evaluations were conducted on the display device components and shock absorbing layer. For the evaluation of the shock absorbing layer, the support substrate was peeled off from the shock absorbing layer obtained in [Step 3] of [Method for Manufacturing Display Device Components 1] and the evaluation was performed. Unless otherwise specified, measurements were taken three times in different locations for one sample in each example, and the average value was used.

[0202] [Thickness of the Impact Absorbing Layer] The thickness of the impact absorbing layer was measured by observing the cross-section using an electron microscope (SEM) according to the following method. The thickness of the layer was read from images of cross-sections of the impact absorbing layer taken with an SEM at a magnification of 3,000x using software (image processing software ImageJ). The average value obtained by measuring the layer thickness at a total of 30 points was used as the measured value.

[0203] [Tensile Yield Strain, Elastic Modulus, Elongation at Break] The shock-absorbing layer was cut into a rectangle 10 mm wide x 150 mm long to serve as the test specimen. The 150 mm length was aligned with the longitudinal direction of the shock-absorbing layer. A tensile test was performed using a tensile testing machine (A&D Co., Ltd. RTG-1210 universal material tester) with an initial tensile chuck distance of 50 mm, a tensile speed of 300 mm / min, and a measurement temperature of 25°C. The stress-strain curve was recorded, and the stress-strain curve between 1% and 5% deformation was linearly approximated. The average value of the slope was defined as the elastic modulus. The strain at the fracture point was defined as the elongation at break of the shock-absorbing layer. Furthermore, the strain corresponding to the first point in the aforementioned stress-strain curve where the strain increases without an increase in stress (yield point) was defined as the tensile yield strain. If no yield point appeared, the tensile yield strain was considered to be infinite (∞).

[0204] [Elastic Limit Strain] The shock-absorbing layer was cut into a rectangle 25 mm wide x 120 mm long to serve as the test specimen. The 120 mm length was aligned with the longitudinal direction of the shock-absorbing layer. A tensile testing machine (A&D Co., Ltd. Universal Material Tester RTG-1210) was used to perform a tensile test with an initial tensile chuck distance of 20 mm, a tensile speed of 300 mm / min, and a measurement temperature of 25°C. After stretching the test specimen to a strain of 4 mm (20%), it was then restored to a strain of 0 mm (0%) at the same speed. This stretching-to-restoration process was repeated a total of 10 times to obtain stress-strain curves for 10 cycles. From these curves, the strain amount S (mm) at which the stress becomes 0 was determined in each restoration step, and the elastic recovery rate z1 (%) was calculated using the following formula, and the average value for the 10 cycles was obtained. Elastic recovery rate z1 = (1 - (S / 20)) × 100 (%). For specimens where the average of these 10 trials exceeded 95%, the elastic limit strain was considered to be 20% or higher. Similarly, after stretching the specimen to a strain of 10 mm (50%), it was then restored to a strain of 0 mm (0%) at the same speed. This stretching-to-restoration process was repeated a total of 10 times, and stress-strain curves for 10 cycles were obtained. From these curves, the strain amount S at which the stress becomes 0 during the restoration process in each stage was identified. ２ The (mm) was determined, and the elastic recovery rate z² (%) was calculated from the following formula, and the average value over 10 trials was found. Elastic recovery rate z² = (1 - (S ２ ( / 20)) × 100 (%). If the average of these 10 measurements exceeds 95%, the elastic limit strain was considered to be 50% or higher.

[0205] [Tensile Hysteresis Loss] The shock-absorbing layer was cut into a rectangle measuring 10 mm wide x 150 mm long to serve as the test specimen. The 150 mm length was aligned with the longitudinal direction of the shock-absorbing layer. A tensile test was performed using a tensile testing machine (A&D Co., Ltd., Universal Material Tester RTG-1210) with an initial chuck distance of 20 mm, a tensile speed of 300 mm / min, and a measurement temperature of 25°C. After stretching the test specimen to a strain of 20 mm (100%), it was then restored to a strain of 0 mm (0%) at the same speed. This stretching-to-restoration process was repeated a total of 10 times to obtain stress-strain curves for 10 cycles. The tensile hysteresis loss was determined according to JIS K7312 (1996), 11. Using the method for calculating hysteresis loss from the stress-strain curve described in section 11.2.4 of the hysteresis loss test, the hysteresis loss was calculated for the stress-strain curve from the first to the tenth test mentioned above, and the average value was taken as the tensile hysteresis loss.

[0206] [Glass Transition Temperature (Tg), Loss Tangent] Based on the tensile vibration-non-resonant method of JIS K7244 (1998) (referred to as the dynamic viscoelastic method), the storage modulus and loss modulus of the shock-absorbing layer were determined using a dynamic viscoelasticity measuring device DMS7100 manufactured by Seiko Instruments Inc. The loss tangent was calculated from the obtained values, and a curve plot of temperature vs. loss tangent was performed. The temperature at which the loss tangent showed a maximum value was defined as the glass transition temperature. If there were multiple temperatures at which the loss tangent showed a maximum value, the temperature at which the loss tangent value was the largest was defined as the glass transition temperature. Measurement mode: Tensile chuck distance: 20 mm Specimen width: 10 mm Frequency: 1 Hz Strain amplitude: 10 μm Initial force amplitude: 40 mN Measurement temperature: -100 °C to 150 °C Heating rate: 5 °C / min Loss tangent: (loss modulus) / (storage modulus).

[0207] [Total Light Transmittance] The impact-absorbing layer was cut into 100 mm wide x 100 mm long pieces to serve as test specimens. Total light transmittance was measured using a haze meter (NDH-5000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 7361-1 (1997).

[0208] [Haze] The impact-absorbing layer was cut into 100 mm wide x 100 mm long pieces to serve as test specimens. The haze was measured using a haze meter (NDH-5000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 7136 (2000).

[0209] [Evaluation of Impact Resistance] Impact resistance was evaluated using the measuring devices shown in Figures 13-14. These devices were used depending on the configuration of the sample being evaluated. First, a stainless steel plate 33 (1 mm thick, 160 mm in diameter, circular) was prepared, and an acceleration sensor 34 was placed directly beneath it. When the sample being evaluated had the protective layer 3 and the shock-absorbing layer 2 directly laminated (without an adhesive layer in between), the shock-absorbing layer 2 and the stainless steel plate 33 were laminated via a transparent optical adhesive film 32, as shown in Figure 13. When the sample being evaluated did not have the protective layer and the shock-absorbing layer 2 directly laminated, a PET film 31 was laminated to one side of the shock-absorbing layer via a transparent optical adhesive film 32, as shown in Figure 14, and the stainless steel plate 33 was laminated to the other side via a transparent optical adhesive film 32. The PET film (50 μm thick), which will be used as the evaluation standard later, was also evaluated using the configuration shown in Figure 14. Next, a steel ball 35 (weighing 4g, with a diameter of 10mm) was dropped from a height of 420mm from the top surface of each component, and the signal detected by the acceleration sensor 34 at that time was recorded every 20μsec. The detected acceleration m / sec ２ The maximum value was recorded, and measurements were taken for each test specimen. Here, the evaluation standard was set to 100% for the value when a PET film (50 μm) was used as the impact absorption layer (configuration shown in Figure 14), and a relative evaluation was performed. Since this is an evaluation of impact resistance, a smaller value indicates higher impact resistance (better impact absorption).

[0210] Table 4 summarizes the evaluation results for each example and comparative example.

[0211]

[0212] 1 Display device component 2 Shock-absorbing layer 3 Protective layer 4 Adhesive layer 5 Surface protective layer 11 Optical display 21 Support substrate 22 Protective material 31 Polyethylene terephthalate film 32 Adhesive layer for evaluation 33 Stainless steel plate 34 Accelerometer 35 Steel ball

[0213] The display device components and films of the present invention have excellent impact resistance and can be suitably used in a variety of applications. For example, they can be used in display device components such as smartphones, flexible displays, liquid crystal displays, organic EL displays, micro-LED displays, mini-LED displays, foldable displays, rollable displays, slidable displays, stretchable displays, see-through displays, tablet terminals, IT equipment, wearable terminals, smartwatches, smart glasses, personal computers, handheld terminals, AR headsets, VR headsets, MR headsets, televisions, digital signage, public information displays, in-vehicle displays, center information displays, and head-up displays. In particular, they can be preferably used in display device components such as smartphones, flexible displays, foldable displays, rollable displays, slidable displays, stretchable displays, tablet terminals, and IT equipment.

[0214] It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0215] This application is based on Japanese Patent Application No. 2025-051263 filed on March 26, 2025, and its contents are incorporated herein by reference.

Claims

1. A display device component comprising a shock-absorbing layer and a protective layer laminated together, wherein the shock-absorbing layer contains a reaction product of a telechelic polymer having 3.0 to 5.0 reactive functional groups per molecule and a weight-average molecular weight of 2,000 or more.

2. The display device member according to claim 1, wherein the shock-absorbing layer is laminated on one side of the protective layer, or the shock-absorbing layer is laminated on both sides of the protective layer.

3. The display device member according to claim 1, wherein the shock-absorbing layer satisfies conditions 1 and 2. Condition 1: The tensile yield strain of the shock-absorbing layer at 25°C is 20% or more, as defined in JIS K7161 (2014). Condition 2: The elastic limit strain of the shock-absorbing layer at 25°C is 20% or more.

4. A display device component comprising a shock-absorbing layer and a protective layer laminated together, wherein the shock-absorbing layer satisfies conditions 1 and 2. Condition 1: The tensile yield strain of the shock-absorbing layer at 25°C, as described in JIS K7161 (2014), is 20% or more. Condition 2: The elastic limit strain of the shock-absorbing layer at 25°C is 20% or more.

5. The display device member according to claim 4, wherein the shock-absorbing layer is laminated on one side of the protective layer, or the shock-absorbing layer is laminated on both sides of the protective layer.

6. A display device component according to any one of claims 1, 3, or 4, satisfying the following conditions 3 and 4: Condition 3: The glass transition temperature in the dynamic viscoelasticity test of the impact absorption layer is -40°C or higher and 30°C or lower. Condition 4: The loss loss tangent at the glass transition temperature in the dynamic viscoelasticity test of the impact absorption layer is 0.5 or higher.

7. A display device component according to any one of claims 1, 3, or 4, satisfying the following condition 5: The tensile hysteresis loss of the shock-absorbing layer at 25°C with 20% strain as defined in JIS K7312 (1996) is less than 10%.

8. A display device member according to any one of claims 1, 3, or 4, satisfying the following conditions 6 and 7: Condition 6: The modulus of elasticity of the shock-absorbing layer at 25°C is 1 MPa or more and 1,000 MPa or less, as specified in JIS K7312 (1996). Condition 7: The elongation at break of the shock-absorbing layer at 25°C is 50% or more, as specified in JIS K7312 (1996).

9. The outermost layer on the visible side has a protective layer (surface protective layer), and the surface protective layer, the impact absorbing layer, and the protective layer are arranged in that order, and the surface protective layer and at least one of the impact absorbing layers are directly laminated, and the thickness T of the surface protective layer １ The thickness T of the shock-absorbing layer ２ A display device component according to any one of claims 1, 3, or 4, wherein formula 1 is satisfied. Formula 1: 0.4 ≤ T １ / (T １ +T ２ ) ≤ 0.8 10. The member for a display device according to any one of claims 1, 3 or 4, wherein the shock absorbing layer comprises segments represented by the following Chemical Formulas 1 to 3. R １ represents hydrogen or a methyl group. R ２ represents any one of the following: a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, an alkylene group having an ether group, an ester group, or an amide group inside the chain thereof, an arylene group having an ether group, an ester group, or an amide group inside the chain thereof, an unsubstituted alkylene group having an ether group, an ester group, or an amide group inside the chain thereof, and an unsubstituted arylene group having an ether group, an ester group, or an amide group inside the chain thereof. R ３ represents any one of the following: a substituted or unsubstituted alkylene group and a substituted or unsubstituted arylene group. R ４ represents any one of the following, and n is an integer of 2 or more: a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, an alkylene group having an ether group or an ester group inside the chain thereof, an arylene group having an ether group or an ester group inside the chain thereof, an unsubstituted alkylene group having an ether group or an ester group inside the chain thereof, and an unsubstituted arylene group having an ether group or an ester group inside the chain thereof 11. The display device member according to any one of claims 1, 3, or 4, wherein the shock-absorbing layer includes a segment of the following chemical formula 4. R ５ , R ６ and R ７ This refers to one of the following. Note that R ５ , R ６ and R ７ These may be the same or different. Substituted or unsubstituted alkylene group Substituted or unsubstituted arylene group 12. A film for a display device component, used in the shock-absorbing layer of a display device component comprising a laminated shock-absorbing layer and a protective layer, wherein the tensile yield strain at 25°C is 20% or more as described in JIS K7161 (2014).

13. A film for a display device component according to claim 12, comprising a reaction product of a telechelic polymer having 3.0 to 5.0 reactive functional groups per molecule and a weight-average molecular weight of 2,000 or more.

Images