Laminate

Abstract

A laminate containing a thin glass film, exhibiting excellent flexibility and impact resistance. [Solution] A laminate comprising, in this order, a glass thin film with a thickness of 25 μm or more and 75 μm or less, a hard layer with a storage modulus of 0.3 GPa or more and 3 GPa or less at 25°C, and a flexible layer with a storage modulus of 0.0001 GPa or more and 0.1 GPa or less at 25°C.

Description

[Technical Field]

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

[0002] Films made of glass typically possess superior properties compared to resins, such as high transparency and scratch resistance, and are therefore used as components for optical elements in image display devices and other applications. Incidentally, in recent years, advances have been made in technologies that make electronic circuits and other components included in optical elements bendable, and bendable image display devices have also appeared. Glass films are sometimes used in foldable image display devices due to their excellent properties, and a technique is known in which a predetermined glass film and a predetermined resin layer are combined to impart flexibility and impact resistance to the glass film (see Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2019 / 066078 [Overview of the project] [Problems that the invention aims to solve]

[0004] Glass films are typically harder but more brittle than resin layers, and making them thin to allow for flexibility sometimes results in insufficient impact resistance. For example, in image display devices that use touch input methods such as pens, the glass film can be damaged by impact during input.

[0005] Therefore, a laminate is required that contains a thin glass film while exhibiting excellent flexibility and impact resistance. [Means for solving the problem]

[0006] The inventors, in an effort to solve the aforementioned problems, conducted thorough research and found that the problems could be solved by combining a glass thin film of a predetermined thickness range with a hard layer and a flexible layer, each having a predetermined storage modulus of elasticity at 25°C. Thus, the inventors completed the present invention. In other words, the present invention provides the following:

[0007] [1] A glass thin film having a thickness of 25 μm or more and 75 μm or less, A hard layer having a storage modulus of 0.3 GPa or more and 3 GPa or less at 25°C, A laminate comprising, in this order, a flexible layer having a storage modulus of 0.0001 GPa or more and 0.1 GPa or less at 25°C, and a layer of flexible material. [2] The laminate according to [1], wherein the glass thin film and the hard layer are in direct contact, and the hard layer and the flexible layer are in direct contact. [3] The laminate according to [1] or [2], wherein the hard layer comprises a thermoplastic resin containing a polymer having a group containing a silicon atom, or a thermoplastic resin containing an organosilicon compound. [4] The laminate according to [3], wherein the polymer having a silicon atom-containing group is a modified form of a hydrogenated aromatic vinyl compound-conjugated diene copolymer with a silicon atom-containing compound. [5] The laminate according to [3], wherein the organosilicon compound is a silane coupling agent. [6] The laminate according to any one of [1] to [5], wherein the hard layer contains a filler. [7] The laminate according to any one of [1] to [6], wherein the storage modulus of the hard layer at 50°C is 0.25 GPa or more and 3 GPa or less. [8] The laminate according to any one of [1] to [7], wherein the tanδ of the hard layer has a maximum value at 25°C or higher, and where tanδ is the ratio of the loss modulus to the storage modulus (loss modulus / storage modulus). [9] The laminate according to any one of [1] to [8], wherein the sum of the thickness of the hard layer and the thickness of the flexible layer is less than 100 μm. [Effects of the Invention]

[0008] According to the present invention, a laminate containing a glass thin film can be provided, which has excellent bending resistance and excellent impact resistance.

Brief Description of the Drawings

[0009] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a laminate according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and can be arbitrarily modified and implemented without departing from the scope of the claims of the present invention and its equivalent scope. The components of the embodiments shown below can be appropriately combined.

[0011] In the following description, the term “(meth)acrylic” includes “acrylic”, “methacrylic” and combinations thereof.

[0012] The storage elastic modulus, loss elastic modulus, and loss tangent tan δ (loss elastic modulus / storage elastic modulus) of the layer can be measured by a dynamic viscoelasticity measuring device. The conditions for dynamic viscoelasticity measurement can be a measurement temperature range of 20°C to 130°C, a heating rate of 3°C / min, and a frequency of 1 Hz.

[0013] [1. Outline of the Laminate] The laminate according to an embodiment of the present invention includes, in this order, a glass thin film having a thickness of 25 μm or more and 75 μm or less, a hard layer having a storage elastic modulus of 0.3 GPa or more and 3 GPa or less at 25°C, and a soft layer having a storage elastic modulus of 0.0001 GPa or more and 0.1 GPa or less at 25°C. By having the above-described configuration, the laminate according to the present embodiment can simultaneously have excellent bending resistance and excellent impact resistance.

[0014] In addition to the glass thin film, the hard layer, and the soft layer, the laminate may include an arbitrary layer. From the perspective of thinning the laminate and making it easier to bend the laminate, it is preferable that the laminate does not have any optional layer between the glass thin film and the hard layer. Also, it is preferable that the laminate does not have any optional layer between the hard layer and the flexible layer.

[0015] FIG. 1 is a cross-sectional view schematically showing a laminate 100 according to an embodiment of the present invention. The laminate 100 includes a glass thin film 110, a hard layer 120, and a flexible layer 130 in this order in the thickness direction. One main surface 110U of the two main surfaces of the glass thin film 110 is in direct contact with one main surface 120D of the two main surfaces of the hard layer 120. Of the two main surfaces of the hard layer 120, the other main surface 120U is in direct contact with one main surface 130D of the two main surfaces of the flexible layer 130. In this way, since the glass thin film 110 and the hard layer 120 of the laminate 100 are in direct contact and the hard layer 120 and the flexible layer 130 are in direct contact, the glass thin film 110 is less likely to be damaged when the laminate 100 is bent.

[0016] In another embodiment, the laminate may include any optional layer such as an adhesive layer having adhesiveness between the glass thin film and the hard layer. In still another embodiment, the laminate may include an optional layer between the hard layer and the flexible layer.

[0017] In yet another embodiment, a resin layer may be provided on the main surface of the glass thin film that does not face the hard layer among the two main surfaces of the glass thin film. It is preferable that the maximum of the loss tangent tanδ of this resin layer is in the range of (20°C - 15°C) or more and (20°C + 15°C) or less. By providing a resin layer having a maximum of tanδ in the above temperature range on the main surface of the glass thin film, the impact applied to the laminate can be mitigated, and it is also difficult for traces of impact to remain on the laminate.

[0018] [2. Glass Thin Film] The thickness of the glass thin film is typically 75 μm or less, preferably 70 μm or less, and more preferably 65 μm or less. Even with such a thin glass thin film, the laminate of this embodiment exhibits excellent impact resistance. Furthermore, the laminate possesses excellent flexibility, which can suppress damage to the glass thin film. The thickness of the glass thin film is typically 25 μm or more, preferably 30 μm or more, and more preferably 35 μm or more. By having a glass thin film thickness equal to or greater than the aforementioned lower limit, the laminate can possess excellent impact resistance.

[0019] Examples of glass used to form thin glass films include, but are not limited to, soda-lime glass, borosilicate glass, and alkali-free glass.

[0020] The glass thin film may have undergone treatments such as cleaning, surface treatment, or chemical strengthening by immersion in a chemical solution.

[0021] [3.Hard layer] [3.1. Physical properties of hard layers] The hard layer has a storage modulus at 25°C of typically 0.3 GPa or higher, preferably 0.35 GPa or higher, and more preferably 0.4 GPa or higher. By having a storage modulus at 25°C of the hard layer that is above the lower limit, the deflection of the glass thin film can be reduced, thereby suppressing the breakage of the glass thin film. The rigid layer has a storage modulus at 25°C that is typically 3 GPa or less, preferably 2.5 GPa or less, and more preferably 2 GPa or less. Having the storage modulus of the rigid layer at 25°C below the aforementioned upper limit allows for a laminate with excellent bending resistance.

[0022] The storage modulus of the hard layer at 50°C is preferably 0.25 GPa or higher, more preferably 0.3 GPa or higher, and even more preferably 0.35 GPa or higher. The storage modulus of the hard layer at 50°C is usually 3 GPa or lower, preferably 2.5 GPa or lower, and more preferably 2 GPa or lower. By having the storage modulus of the hard layer at 50°C within the above range, the deflection of the glass thin film can be reduced even at temperatures higher than room temperature, thereby suppressing damage to the glass thin film and resulting in a laminate with excellent bending resistance.

[0023] The storage modulus of a rigid layer at 25°C can be adjusted by adjusting the composition and formulation of the material forming the rigid layer. For example, it can be adjusted by adding fillers to the material forming the rigid layer, depending on the modulus of the polymer that may be contained in the rigid layer. Generally, increasing the weight proportion of fillers contained in the material forming the rigid layer can increase the storage modulus of the rigid layer at 25°C.

[0024] The hard layer preferably has a maximum value in its loss tangent tanδ (i.e., the ratio of the loss modulus to the storage modulus (loss modulus / storage modulus)) at 25°C or higher. If the hard layer's loss tangent tanδ has multiple maximums, it is preferable that the temperature at at least one of the multiple maximums is 25°C or higher. The tanδ of the hard layer has a maximum value at temperatures above 25°C, which imparts resilience to the hard layer, resulting in a laminate that is less prone to retaining bending marks.

[0025] The temperature at which the tanδ of the hard layer shows a maximum value is preferably 25°C or higher, more preferably 40°C or higher, and even more preferably 50°C or higher, and the upper limit may be, for example, 4000°C or lower.

[0026] The fracture elongation (tensile fracture elongation) of the hard layer is preferably 110% or more, more preferably 120% or more, and even more preferably 125% or more. A higher value is preferable, but it may be 1000% or less. The fracture elongation of the hard layer can be measured in accordance with JIS K7127.

[0027] By ensuring that the elongation at break of the hard layer is above the aforementioned lower limit, the bending resistance of the laminate can be improved. In addition, stress on the glass thin film is less likely to concentrate locally when bent.

[0028] [3.2. Materials for the hard layer] The material for forming the rigid layer is arbitrary, as long as it satisfies the storage modulus requirement at 25°C. An example of a material for forming the rigid layer is a thermoplastic resin. Thermoplastic resins typically consist of a polymer and optional components as needed.

[0029] Examples of polymers that can be included in thermoplastic resins for forming a hard layer include polymers containing alicyclic structures; polymers of vinyl aromatic compounds such as polystyrene; polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyarylene sulfides such as polyphenylene sulfide; polyvinyl alcohol; polycarbonate; polyarylate; cellulose ester polymers; polyethersulfone; polysulfone; polyarylsulfone; polyvinyl chloride; rod-shaped liquid crystal polymers; acrylic polymers such as polyacrylonitrile and polymethyl methacrylate; and multi-component copolymer polymers of these. The polymer may be a homopolymer or a copolymer. Furthermore, the thermoplastic resin may contain a single polymer or a combination of two or more polymers.

[0030] (Thermoplastic resin containing a polymer having a group containing silicon atoms) In one embodiment, the hard layer preferably comprises a thermoplastic resin containing a polymer having groups containing silicon atoms.

[0031] In the following explanation, "groups containing silicon atoms" may be referred to as "Si-containing groups" as appropriate. Similarly, polymers having groups containing silicon atoms may be referred to as "Si polymers" as appropriate.

[0032] In one embodiment, the hard layer preferably comprises only a thermoplastic resin containing a Si polymer. The thermoplastic resin contained in the hard layer may also contain a combination of a Si polymer and an organosilicon compound.

[0033] Si polymers have a high affinity for glass. Therefore, a hard layer containing a thermoplastic resin with a Si polymer can have high adhesion to a glass thin film. Furthermore, this hard layer can improve the resistance of the laminate to bending.

[0034] Si-containing groups are typically polar groups. Therefore, due to the polarity of the Si-containing groups, Si polymers and glass can have a high affinity. Consequently, a hard layer containing a Si polymer can be bonded to a glass thin film with high adhesive strength.

[0035] As the Si-containing group, an alkoxysilyl group is preferred. The alkoxysilyl group can react with hydroxyl groups commonly present on the surface of the glass thin film to form a bond. Therefore, this bond can effectively increase the adhesion strength between the glass thin film and the hard layer.

[0036] Examples of alkoxysilyl groups include trialkoxysilyl groups, alkyldialkoxysilyl groups, and aryldialkoxysilyl groups. The trialkoxysilyl group preferably has 3 to 9 carbon atoms. Examples of trialkoxysilyl groups include trimethoxysilyl and triethoxysilyl groups. The alkyldialkoxysilyl group preferably has 3 to 20 carbon atoms. Examples of alkyldialkoxysilyl groups include methyldimethoxysilyl group, methyldiethoxysilyl group, ethyldimethoxysilyl group, ethyldiethoxysilyl group, propyldimethoxysilyl group, and propyldiethoxysilyl group. The number of carbon atoms in the aryldialkoxysilyl group is preferably 8 to 16. Examples of aryldialkoxysilyl groups include phenyldimethoxysilyl group and phenyldiethoxysilyl group. Among these, the trimethoxysilyl group is preferred from the viewpoint of effectively increasing the adhesive strength between the glass thin film and the hard layer. The Si-containing group may be one type or two or more types.

[0037] Si polymers may have a structure in which Si-containing groups are introduced into the polymer before the introduction of Si-containing groups. The polymer before the introduction of Si-containing groups usually does not contain Si-containing groups. In the following explanation, the polymer before the introduction of Si-containing groups may be referred to as the "pre-reaction polymer" to distinguish it from the Si polymer. For example, a Si polymer having an alkoxysilyl group as a Si-containing group may have a structure in which an alkoxysilyl group is introduced into the pre-reaction polymer.

[0038] The Si polymer may be a graft polymer having Si-containing groups. An example of a graft polymer having Si-containing groups is a graft polymer containing structural units containing Si-containing groups. A structural unit containing Si-containing groups refers to a unit having a structure obtained by polymerizing monomers having Si-containing groups. A graft polymer containing structural units containing Si-containing groups may be a polymer having a structure obtained by graft polymerization of a certain pre-reaction polymer with a monomer having Si-containing groups. However, the above-mentioned graft polymer is not limited by its manufacturing method.

[0039] Examples of polymers used before the reaction include ethylene-α-olefin copolymers such as ethylene-propylene copolymer; ethylene-α-olefin-polyene copolymer; copolymers of ethylene and unsaturated carboxylic acid esters such as ethylene-methyl methacrylate and ethylene-butyl acrylate; copolymers of ethylene and fatty acid vinyl such as ethylene-vinyl acetate; polymers of alkyl acrylates such as ethyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate; diene copolymers such as polybutadiene, polyisoprene, acrylonitrile-butadiene copolymer, butadiene-isoprene copolymer, butadiene-(meth)acrylate alkyl ester copolymer, butadiene-(meth)acrylate alkyl ester-acrylonitrile copolymer, butadiene-(meth)acrylate alkyl ester-acrylonitrile-styrene copolymer; and butylene. Examples include isoprene copolymers; aromatic vinyl compound-conjugated diene copolymers such as styrene-butadiene random copolymers, styrene-isoprene random copolymers, styrene-butadiene block copolymers, styrene-butadiene-styrene block copolymers, styrene-isoprene block copolymers, and styrene-isoprene-styrene block copolymers; hydrogenated aromatic vinyl compound-conjugated diene copolymers such as styrene-butadiene random copolymers, styrene-isoprene random copolymers, styrene-butadiene block copolymers, styrene-butadiene-styrene block copolymers, styrene-isoprene block copolymers, and styrene-isoprene-styrene block copolymers; as well as low-crystallinity polybutadiene, styrene-grafted ethylene-propylene elastomers, thermoplastic polyester elastomers, and ethylene-based ionomers. The polymers used before the reaction may be used individually or in combination of two or more types.

[0040] In particular, polymers selected from aromatic vinyl compound-conjugated diene copolymers, hydrogenated aromatic vinyl compound-conjugated diene copolymers, and combinations thereof are preferred as the polymers to be reacted. Therefore, it is preferable that the Si polymer has a structure in which a Si-containing group is introduced into an aromatic vinyl compound-conjugated diene copolymer, a hydrogenated aromatic vinyl compound-conjugated diene copolymer, and combinations thereof, and it is more preferable that the Si-containing group is introduced into a hydrogenated aromatic vinyl compound-conjugated diene copolymer.

[0041] In other words, the Si polymer is preferably a modified polymer of an aromatic vinyl compound-conjugated diene copolymer, a hydrogenated aromatic vinyl compound-conjugated diene copolymer, or a polymer selected from combinations thereof, with a compound containing silicon atoms, and more preferably a modified hydrogenated aromatic vinyl compound-conjugated diene copolymer with a compound containing silicon atoms. Here, the modified product with a silicon atom-containing compound has a structure obtained by modification with a silicon atom-containing compound, and the modified product is not limited by its manufacturing method.

[0042] As the aromatic vinyl compound-conjugated diene copolymer, an aromatic vinyl compound-conjugated diene block copolymer is preferred. The aromatic vinyl compound-conjugated diene block copolymer is preferably selected from styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, and mixtures thereof.

[0043] A hydrogenated aromatic vinyl compound-conjugated diene copolymer refers to a hydride of an aromatic vinyl compound-conjugated diene copolymer. That is, a hydrogenated aromatic vinyl compound-conjugated diene copolymer has a structure obtained by hydrogenating some or all of the carbon-carbon unsaturated bonds in the main chain and side chains, the carbon-carbon bonds in the aromatic ring, or both of these, of an aromatic vinyl compound-conjugated diene copolymer. However, the copolymer and hydride are not limited by their manufacturing method.

[0044] The hydrogenation rate of the hydrogenated aromatic vinyl compound-conjugated diene copolymer is usually 90% or higher, preferably 97% or higher, and more preferably 99% or higher. The higher the hydrogenation rate, the better the heat resistance and light resistance of the resin. Here, the hydrogenation rate of the hydride is 1 This can be determined by measurement using 1H-NMR.

[0045] The hydrogenation rate of the carbon-carbon unsaturated bonds in the main chain and side chains of the hydrogenated aromatic vinyl compound-conjugated diene copolymer is preferably 95% or higher, more preferably 99% or higher. By increasing the hydrogenation rate of the carbon-carbon unsaturated bonds in the main chain and side chains of the hydrogenated aromatic vinyl compound-conjugated diene copolymer, the light resistance and oxidation resistance of the resin can be further improved.

[0046] Furthermore, the hydrogenation rate of the carbon-carbon unsaturated bond of the aromatic ring in the hydrogenated aromatic vinyl compound-conjugated diene copolymer is preferably 90% or more, more preferably 93% or more, and particularly preferably 95% or more. By increasing the hydrogenation rate of the carbon-carbon unsaturated bond of the aromatic ring, the glass transition temperature of the hydride is increased, thereby effectively improving the heat resistance of the resin. In addition, the photoelastic coefficient of the resin can be lowered, reducing the occurrence of retardation in the hard layer.

[0047] As the hydrogenated aromatic vinyl compound-conjugated diene copolymer, a hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferred. The hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferably selected from hydrogenated styrene-butadiene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-isoprene-styrene block copolymer, and mixtures thereof. More specific examples of these are described in technical literature such as Japanese Patent Publication No. 2-133406, Japanese Patent Publication No. 2-305814, Japanese Patent Publication No. 3-72512, Japanese Patent Publication No. 3-74409, and International Publication No. 2015 / 099079.

[0048] As a hydrogenated aromatic vinyl compound-conjugated diene block copolymer, it is preferable to have a structure in which both the unsaturated bond and the aromatic ring of the conjugated diene are hydrogenated.

[0049] Particularly preferred block forms of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer are a triblock copolymer in which blocks [A] of aromatic vinyl polymer hydride are bonded to both ends of a block [B] of conjugated diene polymer hydride; and a pentablock copolymer in which polymer blocks [B] are bonded to both ends of polymer block [A], and polymer blocks [A] are further bonded to the other ends of each of the polymer blocks [B]. In particular, a [A]-[B]-[A] triblock copolymer is particularly preferred because it is easy to manufacture and allows the physical properties of the block copolymer to be within a desirable range.

[0050] In a hydrogenated aromatic vinyl compound-conjugated diene block copolymer, the ratio (wA / wB) of the weight fraction wA of total polymer block [A] in the entire block copolymer to the weight fraction wB of total polymer block [B] in the entire block copolymer is usually 20 / 80 or more, preferably 30 / 70 or more, and usually 60 / 40 or less, preferably 55 / 45 or less. When the ratio wA / wB is above the lower limit of the above range, the heat resistance of the resin can be improved. When it is below the upper limit, the flexibility of the resin can be increased. Furthermore, when the ratio wA / wB is within the above range, breakage due to bending of the glass thin film can be particularly effectively suppressed.

[0051] By reacting the aforementioned polymer before reaction with a compound having a Si-containing group, a Si-containing group can be introduced into the polymer before reaction to obtain a Si polymer. Specifically, by reacting the polymer before reaction with a monomer having a Si-containing group, a graft polymer having a Si-containing group can be obtained. Examples of compounds having a Si-containing group that can be used as a monomer include vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, and 2-norbornene-5-yltrimethoxysilane, which are ethylenically unsaturated silane compounds having an alkoxysilyl group. The Si-containing compound may be used alone or in combination of two or more types.

[0052] When introducing alkoxysilyl groups, the amount of alkoxysilyl groups introduced is usually 0.1 parts by weight or more, preferably 0.2 parts by weight or more, more preferably 0.3 parts by weight or more, and usually 10 parts by weight or less, preferably 5 parts by weight or less, and more preferably 3 parts by weight or less, per 100 parts by weight of the polymer before reaction. When the amount of alkoxysilyl groups introduced is within the above range, it is possible to suppress the excessively high degree of crosslinking between alkoxysilyl groups that have been decomposed by moisture, thereby maintaining high adhesion. An example of a method for introducing alkoxysilyl groups is described in International Publication No. 2015 / 099079. In addition, the amount of Si-containing groups is 1 The amount can be measured using 1H-NMR spectroscopy. When measuring the amount of Si-containing groups, if the amount of Si-containing groups is small, the number of integration steps can be increased.

[0053] As described above, the introduction of alkoxysilyl groups into the polymer before reaction is called silane modification. In silane modification, the alkoxysilyl groups may be directly bonded to the polymer before reaction, or they may be bonded via a divalent organic group such as an alkylene group. Hereinafter, the polymer obtained by silane modification of the polymer before reaction may also be called a "silane-modified polymer." As the silane-modified polymer, one or more polymers selected from silane-modified styrene-butadiene block copolymers, silane-modified styrene-butadiene-styrene block copolymers, silane-modified styrene-isoprene block copolymers, and silane-modified styrene-isoprene-styrene block copolymers are preferred.

[0054] The weight-average molecular weight (Mw) of the Si polymer is preferably 20,000 or more, more preferably 30,000 or more, particularly preferably 35,000 or more, preferably 200,000 or less, more preferably 100,000 or less, particularly preferably 70,000 or less. The molecular weight distribution (Mw / Mn) of the Si polymer is preferably 4 or less, more preferably 3 or less, particularly preferably 2 or less, and preferably 1 or more. Here, Mn represents the number-average molecular weight. When the weight-average molecular weight Mw and molecular weight distribution Mw / Mn of the Si polymer are within the above ranges, the mechanical strength and heat resistance of the resin can be improved. The weight-average molecular weight of the polymer can be measured in polystyrene equivalent values ​​by gel permeation chromatography (hereinafter also referred to as "GPC") using tetrahydrofuran as the solvent.

[0055] The glass transition temperature Tg of the Si polymer is not particularly limited, but is preferably 40°C or higher, more preferably 70°C or higher, preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 160°C or lower. The glass transition temperature can be measured from the peak of the loss tangent tanδ (loss modulus / storage modulus) measured using a dynamic viscoelasticity measuring device.

[0056] The amount of Si polymer contained in the thermoplastic resin is preferably 30% by weight or more, more preferably 35% by weight or more, relative to 100% by weight of the thermoplastic resin, and is usually 100% by weight or less, preferably 95% by weight or less, more preferably 90% by weight or less, and particularly preferably 85% by weight or less.

[0057] (Thermoplastic resin containing organosilicon compounds) In another embodiment, the hard layer preferably comprises a thermoplastic resin containing an organosilicon compound. In one embodiment, the hard layer preferably comprises only a thermoplastic resin containing an organosilicon compound.

[0058] Organosilicon compounds have a high affinity for glass. Therefore, a hard layer containing a thermoplastic resin that includes an organosilicon compound can have high adhesion to a glass thin film. Furthermore, this hard layer can improve the resistance of the laminate to bending.

[0059] Thermoplastic resins containing organosilicon compounds typically consist of a polymer and an organosilicon compound in combination. Examples of polymers include acrylic polymers, urethane polymers, polyester polymers, rubber polymers, and epoxy polymers. Alternatively, the polymer may be the Si polymer mentioned above, or its pre-reaction polymer. The polymer may be used individually or in combination of two or more types.

[0060] The weight-average molecular weight (Mw) of the polymer contained in the thermoplastic resin containing the organosilicon compound is not particularly limited, but it is preferably within the same range as the weight-average molecular weight (Mw) of the Si polymer. Furthermore, the molecular weight distribution (Mw / Mn) of the polymer contained in the thermoplastic resin containing the organosilicon compound is preferably within the same range as the molecular weight distribution (Mw / Mn) of the Si polymer. In addition, the glass transition temperature of the polymer contained in the thermoplastic resin containing the organosilicon compound is preferably within the same range as the glass transition temperature of the Si polymer.

[0061] The amount of polymer contained in a thermoplastic resin containing organosilicon compounds is preferably within the same range as the amount of Si polymer contained in a thermoplastic resin containing Si polymers.

[0062] Organosilicon compounds contain a combination of organic groups and silicon atoms. The organic groups of organosilicon compounds exhibit high affinity to organic components such as polymers contained in thermoplastic resins. Furthermore, the silicon atoms of organosilicon compounds exhibit high affinity to glass thin films. Therefore, hard layers containing organosilicon compounds have high adhesion to glass thin films.

[0063] As organosilicon compounds, silane coupling agents are preferred. Silane coupling agents can particularly effectively increase the adhesion strength between the glass thin film and the hard layer. Examples of silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-(2-amino Examples include N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, and 3-isocyanatetopropyltriethoxysilane.

[0064] Organosilicon compounds may be used individually or in combination of two or more types.

[0065] The amount of organosilicon compound is preferably 0.01 parts by weight or more, more preferably 0.03 parts by weight or more, particularly preferably 0.05 parts by weight or more, preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and particularly preferably 3 parts by weight or less, per 100 parts by weight of polymer.

[0066] (Thermoplastic resin containing alicyclic structure polymers) In another embodiment, the thermoplastic resin for forming the hard layer preferably includes an alicyclic structure-containing polymer as the polymer.

[0067] Alicyclic structure-containing polymers are polymers that contain an alicyclic structure within their repeating units. Alicyclic structure-containing polymers typically exhibit excellent mechanical strength, transparency, low water absorption, moisture resistance, dimensional stability, and lightweight properties. Alicyclic structure-containing polymers may be amorphous or crystalline.

[0068] Examples of alicyclic structure-containing polymers include polymers or their hydrides that can be obtained by polymerization reactions using cyclic olefins as monomers. Furthermore, as the alicyclic structure-containing polymers, either polymers containing alicyclic structures in the main chain or polymers containing alicyclic structures in the side chains can be used. Among these, it is preferable that the alicyclic structure-containing polymer contains an alicyclic structure in the main chain. Examples of alicyclic structures include cycloalkane structures and cycloalkene structures, but cycloalkane structures are preferred from the viewpoint of thermal stability, etc.

[0069] The number of carbon atoms in a single alicyclic structure is preferably 4 or more, more preferably 5 or more, more preferably 6 or more, preferably 30 or less, more preferably 20 or less, and particularly preferably 15 or less. Having the number of carbon atoms in a single alicyclic structure within this range provides a high degree of balance between mechanical strength, heat resistance, and moldability.

[0070] The proportion of repeating units having an alicyclic structure in the alicyclic structure-containing polymer is preferably 30% by weight or more, more preferably 50% by weight or more, even more preferably 70% by weight or more, and particularly preferably 90% by weight or more. By increasing the proportion of repeating units having an alicyclic structure as described above, heat resistance can be improved. Furthermore, in polymers containing alicyclic structures, the remainder other than the repeating units having an alicyclic structure is not particularly limited and can be appropriately selected depending on the intended use.

[0071] Examples of polymers containing alicyclic structures include (1) norbornene polymers, (2) monocyclic olefin polymers, (3) cyclic conjugated diene polymers, (4) vinyl alicyclic hydrocarbon polymers, and their hydrides. Among these, norbornene polymers and their hydrides are preferred from the viewpoint of transparency and moldability.

[0072] Examples of norbornene polymers include ring-opening polymers of monomers having a norbornene structure and their hydrides; and addition polymers of monomers having a norbornene structure and their hydrides. Furthermore, examples of ring-opening polymers of monomers having a norbornene structure include ring-opening homopolymers of one type of monomer having a norbornene structure, ring-opening copolymers of two or more types of monomers having a norbornene structure, and ring-opening copolymers of a monomer having a norbornene structure and any monomer copolymerizable therewith. In addition, examples of addition polymers of monomers having a norbornene structure include addition homopolymers of one type of monomer having a norbornene structure, addition copolymers of two or more types of monomers having a norbornene structure, and addition copolymers of a monomer having a norbornene structure and any monomer copolymerizable therewith. Among these, the hydrides of ring-opening polymers of monomers having a norbornene structure are particularly preferred from the viewpoint of moldability, heat resistance, low hygroscopicity, low moisture permeability, dimensional stability, and lightweight properties.

[0073] Examples of monomers having a norbornene structure include bicyclo[2.2.1]hepto-2-ene (common name: norbornene), tricyclo[4.3.0.1 2,5 Deca-3,7-diene (common name: dicyclopentadiene), 7,8-benzotricyclo[4.3.0.1 2,5 Deca-3-ene (common name: methanotetrahydrofluorene), tetracyclo[4.4.0.1 2,5 .1 7,10Examples include dodeca-3-ene (common name: tetracyclododecene) and derivatives of these compounds (for example, those having substituents on the ring). Here, examples of substituents include alkyl groups, alkylene groups, and polar groups. Multiple substituents may be bonded to the ring, either identical or different in nature. Monomers having a norbornene structure may be used individually or in combination of two or more types in any ratio.

[0074] Ring-opening polymers of monomers having a norbornene structure can be produced, for example, by polymerizing or copolymerizing monomers in the presence of a ring-opening polymerization catalyst.

[0075] Addition polymers of monomers having a norbornene structure can be produced, for example, by polymerizing or copolymerizing monomers in the presence of an addition polymerization catalyst.

[0076] The hydrides of the ring-opening polymers and addition polymers described above can be produced, for example, by hydrogenating the carbon-carbon unsaturated bonds by preferably 90% or more in a solution of the ring-opening polymer or addition polymer in the presence of a hydrogenation catalyst containing a transition metal such as nickel or palladium.

[0077] The weight-average molecular weight (Mw) of the alicyclic structure-containing polymer is preferably 10,000 or more, more preferably 15,000 or more, even more preferably 20,000 or more, preferably 100,000 or less, more preferably 80,000 or less, and even more preferably 50,000 or less. Alicyclic structure-containing polymers having such a weight-average molecular weight exhibit an excellent balance of mechanical strength, moldability, and heat resistance.

[0078] The molecular weight distribution (Mw / Mn) of the alicyclic structure-containing polymer is preferably 1.2 or higher, more preferably 1.5 or higher, even more preferably 1.8 or higher, preferably 3.5 or lower, more preferably 3.4 or lower, and even more preferably 3.3 or lower. When the molecular weight distribution is above the lower limit of the above range, the productivity of the alicyclic structure-containing polymer can be increased and manufacturing costs can be suppressed. Furthermore, when it is below the upper limit, the amount of low molecular weight components is reduced, which can improve the stability of the layer containing the alicyclic structure-containing polymer.

[0079] The weight-average molecular weight Mw and number-average molecular weight Mn of alicyclic polymers can be measured in polyisoprene equivalent values ​​by GPC using cyclohexane as the solvent. If the resin does not dissolve in cyclohexane, the values ​​can be measured in polystyrene equivalent values ​​by GPC using toluene as the solvent.

[0080] The glass transition temperature of the alicyclic structure-containing polymer is preferably 50°C or higher, more preferably 65°C or higher, even more preferably 70°C or higher, preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 170°C or lower.

[0081] (Any component) The thermoplastic resin capable of forming a hard layer may contain any component in combination with the polymer. The component may be used individually or in combination of two or more components in any ratio.

[0082] A thermoplastic resin capable of forming a hard layer may, for example, contain a hydrogenated C9 petroleum resin as an optional component. A hydrogenated C9 petroleum resin is a resin obtained by hydrogenating a C9 petroleum resin obtained by cationic polymerization of a C9 fraction obtained by cracking naphtha. The C9 fraction is a fraction mainly containing hydrocarbons with 9 carbon atoms, and includes, for example, styrene, vinyltoluene, α-methylstyrene, indenes, etc. The polymers contained in hydrogenated C9 petroleum resins have a cyclic skeleton, and their movement is restricted due to steric hindrance; therefore, materials containing hydrogenated C9 petroleum resins tend to be rigid. The hydrogenated C9 petroleum resin is not limited by its manufacturing method.

[0083] By including hydrogenated C9 petroleum resin in a thermoplastic resin capable of forming a hard layer, the hardness of the hard layer can be increased without changing its hue. Therefore, by appropriately incorporating hydrogenated C9 petroleum resin into the thermoplastic resin, the storage modulus of the hard layer can be adjusted to a desired range.

[0084] Examples of commercially available products containing hydrogenated C9 petroleum resins include Alcon P100, P115, P135, and P140 manufactured by Arakawa Chemical Industries, Ltd.

[0085] The amount of hydrogenated C9 petroleum resin is preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 15% by weight or more, preferably 50% by weight or less, more preferably 45% by weight or less, and even more preferably 40% by weight or less, in the thermoplastic resin capable of forming a hard layer. By incorporating hydrogenated C9 petroleum resin in the above proportions into a thermoplastic resin, particularly a thermoplastic resin containing a Si polymer, the storage modulus of the hard layer can be easily adjusted to a desired range.

[0086] A thermoplastic resin capable of forming a hard layer may contain fillers. By including fillers in addition to the polymer in the thermoplastic resin capable of forming a hard layer, the hardness of the hard layer can be increased, and the storage modulus of the hard layer can be easily adjusted to a desired range.

[0087] The fillers that may be included in thermoplastic resins may be inorganic or organic substances, or composites of inorganic and organic substances. Examples of fillers include zeolite, magnesium oxide, aluminum oxide, talc, hydrotalcite, titanium dioxide, calcium oxide, and the like.

[0088] The filler is usually in particulate form. The average particle size of the filler is preferably 0.01 μm or more, more preferably 0.02 μm or more, even more preferably 0.05 μm or more, preferably 1 μm or less, more preferably 0.5 μm or less, and even more preferably 0.3 μm or less. Here, the average particle diameter of the filler is the volume-average particle diameter measured by laser diffraction using the LA-960V series laser diffraction / scattering particle size distribution analyzer manufactured by Horiba, Ltd. By having an average particle size of the filler within the aforementioned range, the filler is well dispersed in the hard layer, and the storage modulus of the hard layer can be easily adjusted to a desired range.

[0089] The amount of filler is preferably 20% by weight or more, more preferably 30% by weight or more, even more preferably 40% by weight or more, preferably 80% by weight or less, more preferably 75% by weight or less, and even more preferably 70% by weight or less, in the thermoplastic resin capable of forming a hard layer. By incorporating the filler into the thermoplastic resin in the above proportions, the storage modulus of the hard layer can be easily adjusted to a desired range.

[0090] A thermoplastic resin capable of forming a hard layer may, for example, contain an antioxidant as an optional component. Examples of antioxidants include phosphorus-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants, with phosphorus-based antioxidants being preferred due to their less discoloration.

[0091] Examples of phosphorus-based antioxidants include monophosphine compounds such as triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, tris(dinonylphenyl) phosphite, tris(2,4-di-t-butylphenyl) phosphite, and 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; and 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl-di-tridecyl phosphate). Examples of diphosphite compounds include sphite, 4,4'-isopropylidene-bis(phenyl-di-alkyl(C12~C15)phosphite); and compounds such as 6-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetrakis-t-butyldibenzo[d,f][1.3.2]dioxaphosfepine and 6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy]-2,4,8,10-tetrakis-t-butyldibenzo[d,f][1.3.2]dioxaphosfepine. Furthermore, the antioxidant may be used alone or in combination of two or more types.

[0092] The amount of antioxidant is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, particularly preferably 0.1 parts by weight or more, preferably 1 part by weight or less, more preferably 0.5 parts by weight or less, and particularly preferably 0.3 parts by weight or less, per 100 parts by weight of polymer contained in the thermoplastic resin.

[0093] Other optional components that may be included in a thermoplastic resin capable of forming a hard layer include, for example, light stabilizers, ultraviolet absorbers, lubricants, and the aforementioned organosilicon compounds.

[0094] [3.3. Thickness of the hard layer] The thickness of the hard layer is preferably 3 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less. By having the thickness of the hard layer within the above range, the bending resistance of the laminate can be effectively improved, suppressing breakage of the glass thin film, while also improving the impact resistance of the laminate.

[0095] [4.Flexible layer] [4.1. Physical properties of the flexible layer] The flexible layer has a storage modulus at 25°C that is typically 0.0001 GPa or higher, preferably 0.0002 GPa or higher, and more preferably 0.0003 GPa or higher. The flexible layer has a storage modulus at 25°C that is typically 0.1 GPa or lower, preferably 0.05 GPa or lower, and more preferably 0.01 GPa or lower. Because the storage modulus of the flexible layer at 25°C is within the aforementioned range, a laminate with excellent bending resistance can be obtained. In addition, the flexible layer can absorb impact.

[0096] The storage modulus of the flexible layer can be adjusted, for example, by adjusting the types and proportions of components contained in the material used to form the flexible layer. In particular, the storage modulus can be easily adjusted by adjusting the proportion of the softener contained in the material used to form the flexible layer.

[0097] [4.2. Materials for the flexible layer] The material forming the flexible layer is arbitrary, as long as it satisfies the storage modulus condition at 25°C. Examples of materials forming the flexible layer include thermoplastic resins.

[0098] Thermoplastic resins capable of forming a flexible layer typically contain a polymer and optional components as needed. Examples of polymers include: aromatic vinyl compound-conjugated diene copolymers; hydrogenated aromatic vinyl compound-conjugated diene copolymers; Si polymers (e.g., polymers having a structure in which Si-containing groups are introduced into polymers selected from aromatic vinyl compound-conjugated diene copolymers, hydrogenated aromatic vinyl compound-conjugated diene copolymers, and combinations thereof); acrylic polymers; urethane polymers; rubber polymers; alicyclic structure-containing polymers; olefin polymers, etc.

[0099] The polymer may be a homopolymer or a copolymer. Furthermore, the thermoplastic resin capable of forming a flexible layer may contain a single polymer or a combination of two or more polymers.

[0100] Thermoplastic resins capable of forming a flexible layer may contain optional components in addition to the polymer. An example of an optional component is a plasticizer. Plasticizers can reduce the storage modulus of the thermoplastic resin.

[0101] As a softening agent, a compound that is itself liquid under normal temperature and pressure conditions may be used. Furthermore, a compound compatible with the polymer contained in the thermoplastic resin capable of forming a flexible layer is preferred as the softening agent. Suitable examples of softening agents include hydrocarbon monomers and oligomers; organic acid ester softening agents such as monobasic organic acid esters and polybasic organic acid esters; and phosphate ester softening agents such as organic phosphate esters and organic phosphite esters. The softening agent may be used alone or in combination of two or more types. Among these, hydrocarbon monomers and oligomers are preferred.

[0102] Specific examples of hydrocarbon monomers and oligomers include polyisobutylene, polybutene, poly-4-methylpentene, liquid paraffin, poly-1-octene, ethylene-α-olefin copolymer, polyisoprene, alicyclic hydrocarbons, other aliphatic hydrocarbons, aromatic vinyl compound-conjugated diene copolymers, hydrides of the above compounds, and indene-styrene copolymer hydrides. Among these, polyisobutylene, polybutene, hydrogenated polyisobutylene, and hydrogenated polybutene are preferred. Many of these hydrocarbon monomers and oligomers have good compatibility with polymers, and are particularly compatible with the Si polymer.

[0103] Hydrocarbon monomers and oligomers are preferred because they are polymers of hydrocarbon compounds having a specific molecular weight range, and they disperse well in the components constituting the adhesive layer without significantly impairing heat resistance. The number-average molecular weight of the hydrocarbon oligomer is preferably 200 to 5,000, more preferably 300 to 3,000, and even more preferably 500 to 2,000. For example, polybutenes with a number-average molecular weight in the above range can be uniformly mixed with polymers having alkoxysilyl groups in any proportion.

[0104] The amount of softening agent is preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 15% by weight or more, preferably 70% by weight or less, more preferably 60% by weight or less, and particularly preferably 50% by weight or less, in the thermoplastic resin capable of forming a flexible layer.

[0105] Examples of other optional components in a thermoplastic resin that can form a flexible layer include the components exemplified as optional components that can be included in a thermoplastic resin that can form a rigid layer. For example, a thermoplastic resin that can form a flexible layer may contain antioxidants in addition to the polymer.

[0106] The amount of antioxidant is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, particularly preferably 0.1 parts by weight or more, preferably 1 part by weight or less, more preferably 0.5 parts by weight or less, and particularly preferably 0.3 parts by weight or less, per 100 parts by weight of polymer contained in the thermoplastic resin.

[0107] A commercially available optically transparent adhesive film (OCA film) can be used as the flexible layer. Examples of commercially available products include Nitto Denko's "CS9861US" and Lintec's "NCF-D692".

[0108] The thickness of the flexible layer is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 20 μm or more, preferably 70 μm or less, more preferably 60 μm or less, and even more preferably 50 μm or less.

[0109] Furthermore, the sum T of the thickness of the flexible layer and the hard layer is preferably less than 100 μm, more preferably 80 μm or less, and even more preferably 70 μm or less, and is usually greater than 0 μm, preferably 10 μm or more, and more preferably 20 μm or more. By having the sum T within the above range, the bending resistance of the laminate can be effectively improved.

[0110] [5. Other physical properties of laminates] The laminate of this embodiment has excellent impact resistance and excellent bending resistance. The impact resistance of the laminate can be evaluated by the following pendrop height test. The laminate is attached to a stainless steel plate and placed on a metal plate with the glass thin film facing upwards. Next, a 5g ballpoint pen with a 0.7mm diameter tip is dropped onto the laminate test piece with the tip facing downwards. The height from the laminate to the pen tip is increased by 1cm increments until cracking occurs in the glass thin film. The highest height from the laminate to the pen tip at which no cracking occurs is defined as the pen drop test height (cm).

[0111] The pendrop test height of the laminate is preferably 10 cm or more, and more preferably 12 cm or more.

[0112] The bending resistance of the laminate can be evaluated by the following bending test. The laminate is cut into a rectangular shape measuring 50 mm x 120 mm to form a bending test specimen. The bending test specimen is bent so that the glass thin film faces inward and a bend occurs along its long side, and then sandwiched between two parallel plate-like bodies (initial gap between the plate-like bodies = 100 mm). The gap between the two plate-like bodies in which the bending test specimen is sandwiched is narrowed at a speed of 50 mm / min, thereby compressing and bending the bending test specimen. If the bending test specimen does not break even when the gap between the plate-like bodies is 6 mm, that is, if the bending test specimen does not break even when the radius of curvature R of the bending test specimen is 3 mm, then the laminate can be said to have excellent bending resistance.

[0113] Because the laminate has such excellent flexibility, it can be combined with a bendable element (for example, a bendable image display device). In particular, when the laminate is used in combination with a bendable element so that the glass thin film contained in the laminate is subjected to large tensile stress, the breakage of the glass thin film can be effectively suppressed.

[0114] The haze of the laminate is preferably 3% or less, more preferably 2% or less, and even more preferably 1% or less. It is preferable that it be small, usually 0% or more, and may be 0.1% or more. Such low haze of the laminate makes it suitable for use as an element in an image display device. The haze can be measured by a turbidimeter.

[0115] [6. Applications of laminates] Because the laminate possesses excellent flexibility and impact resistance, it can be suitably used, for example, as a substitute for cover glass in a foldable image display device. In particular, by providing the laminate in the image display device so that the glass thin film faces the viewing side, the flexibility and impact resistance of the laminate can be effectively demonstrated.

[0116] [7. Method for manufacturing laminates] The laminate can be manufactured by any method. For example, the laminate can be manufactured by bonding a glass thin film, a rigid layer, and a flexible layer. An adhesive may be used as needed during bonding. In this specification, the adhesive includes pressure-sensitive adhesives.

[0117] Alternatively, for example, a hard layer may be formed on a glass thin film by preparing a hard layer-forming solution containing a material and a solvent for forming a hard layer, applying it to one main surface of a glass thin film to form a coating layer, and then drying the coating layer. In this specification, the term "solvent" includes dispersion media, and the term "solution" includes dispersion liquids.

[0118] Alternatively, for example, the hard layer forming solution may be applied to a substrate to form a coating layer, and the coating layer may be dried to form a hard layer on the substrate. Then, the hard layer on the substrate may be transferred to one main surface of a glass thin film to produce an intermediate laminate containing a (glass thin film) / (hard layer) layer structure, and then a flexible layer may be laminated on the hard layer of the intermediate laminate.

[0119] Alternatively, for example, a flexible layer-forming solution may be prepared containing a material and a solvent for forming a flexible layer, this flexible layer-forming solution may be applied to a substrate to form a coating layer, the coating layer may be dried to form a flexible layer on the substrate, and then the flexible layer on the substrate may be transferred to the main surface of a hard layer separate from the main surface facing the glass thin film to produce a laminate having a layer structure of (glass thin film) / (hard layer) / (flexible layer).

[0120] The stacking order of each layer in the laminate is not particularly limited. For example, a glass thin film and a hard layer may be stacked, followed by a flexible layer. Alternatively, a hard layer and a flexible layer may be stacked, followed by a glass thin film. [Examples]

[0121] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the examples shown below, and can be modified and implemented as appropriate without departing from the scope of the claims and equivalents of the present invention.

[0122] In the following explanation, "%" and "parts" used to express quantities refer to weight unless otherwise specified. Furthermore, the operations described below were performed under normal temperature (20°C ± 15°C) and atmospheric pressure (1 atm) conditions unless otherwise specified.

[0123] [Evaluation Method] (Method for measuring the molecular weight of polymers) The weight-average molecular weight (Mw), number-average molecular weight (Mn), and molecular weight distribution (Mw / Mn) of the polymers were measured in polystyrene equivalent values ​​by gel permeation chromatography (GPC) using tetrahydrofuran as the solvent, unless otherwise specified. The weight-average molecular weight (Mw), number-average molecular weight (Mn), and molecular weight distribution (Mw / Mn) of norbornene polymer (b) were measured using GPC with cyclohexane as the solvent, and the values ​​were expressed on a polyisoprene basis.

[0124] (Method for measuring the hydrogenation rate of hydrides) The hydrogenation rate of a hydride is 1 This was determined by measurement using 1H-NMR.

[0125] (Measurement of volume-average particle size of filler) The volume-average particle size of the filler was measured using a hard layer-forming solution containing the filler as a sample, based on laser diffraction using a HORIBA LA-960V series laser diffraction / scattering particle size distribution analyzer.

[0126] (thickness of the layer) The layer thickness was measured using a thickness gauge manufactured by Mitutoyo Corporation.

[0127] (Glass transition temperature) Unless otherwise specified, the glass transition temperature (Tg) of polymers was measured as follows. First, the polymer was melted by heating, and the molten polymer was rapidly cooled with dry ice. Next, using this polymer as a test specimen, the glass transition temperature Tg of the polymer was measured using a differential scanning calorimeter (DSC) at a heating rate of 10°C / min (heating mode).

[0128] (Measurement of storage modulus, loss modulus, and tanδ) A 38 μm thick polyethylene terephthalate film (Mitsubishi Chemical's "MRV38," hereinafter also referred to as release PET film) with a release treatment applied to its surface was prepared. A hard layer forming solution or a flexible layer forming solution was applied to the release PET film so that the thickness after drying would be 100 μm, and the film was dried on a hot plate at 110°C to form a sample film on the release PET film. The obtained sample film was peeled off the release PET film, and a test piece measuring 10 mm in width and 20 mm in length was cut from the sample film. For the cut test specimens, the storage modulus, loss modulus, and tanδ (loss modulus / storage modulus) were measured using a dynamic viscoelasticity analyzer (Hitachi High-Tech Science Corporation's "DMA7100") at a heating rate of 3°C / min and a frequency of 1 Hz. The measurement temperature range was 20°C to 130°C for the hard layer and 20°C to 140°C for the flexible layer. From the measurement results, the temperature at which the storage modulus, loss modulus, and tanδ showed maximum values ​​(tanδ peak temperature) at measurement temperatures of 25°C or 50°C was read.

[0129] (Haze measurement) The haze of the laminate was measured using a turbidimeter (NDH-2000, manufactured by Nippon Denshoku Co., Ltd.).

[0130] (Measurement of elongation at break (tensile fracture elongation)) A hard layer forming solution was applied to a release PET film to a thickness of 50 μm after drying, and the sample film was formed on the release PET film by drying it on a hot plate at 110°C. The obtained sample film was peeled off the release PET film, and the elongation at break (%) of the hard layer at 25°C was measured in accordance with JIS K7127.

[0131] (Pendrop height test) A pendrop height test was performed on the resulting laminate. The laminate was cut into 50mm squares, and the cut laminate was attached to a 50mm square, 0.5mm thick stainless steel plate so that the glass thin film was exposed on the surface to create a laminate test specimen. The attachment was performed while heating the stainless steel plate on a hot plate. The laminated test specimen was placed on a metal plate with the exposed glass thin film facing upwards. Next, a 5g ballpoint pen with a 0.7mm diameter tip was dropped onto the laminated test specimen tip-down. The height from the laminated test specimen to the pen tip was increased by 1cm increments until cracking occurred in the glass thin film. The highest height from the laminated test specimen to the pen tip that did not cause cracking was defined as the pen drop test height (cm). The higher the pen drop test height, the better the impact resistance of the laminate.

[0132] (Two-point bending test) A two-point bending test was performed on the resulting laminate. A rectangular piece measuring 50 mm x 120 mm was cut from the laminate to form a bending test specimen. The bending test specimen was bent so that the glass thin film was on the inside and a bend occurred along the longer side, and then sandwiched between two parallel plate-like bodies (initial gap between the plates = 100 mm). The bending test specimen was bent by narrowing the gap between the two plate-like bodies at a speed of 50 mm / min. If the bending test specimen did not break even when the gap between the plate-like bodies was 6 mm, it was considered a pass (A). A gap of 6 mm between the plate-like bodies means that the radius of curvature R of the bending test specimen is 3 mm. If the bending test specimen broke when the gap between the plate-like bodies was less than 6 mm, it was considered a fail (R).

[0133] [Manufacturing Example 1: Production of a polymer (a) having a polar group containing silicon atoms] (Manufacturing of hydrogenated block copolymers) Using styrene as the aromatic vinyl compound and isoprene as the chain-like conjugated diene compound, a hydrogenated block copolymer (hydrogenated block copolymer) having a triblock structure in which polymer blocks [A] are bonded to both ends of polymer block [B] was produced by the following procedure.

[0134] In a reactor equipped with a stirring device and thoroughly purged with nitrogen, 256 parts of dehydrated cyclohexane, 25.0 parts of dehydrated styrene, and 0.615 parts of n-dibutyl ether were added. Polymerization was initiated by adding 1.35 parts of n-butyllithium (15% cyclohexane solution) while stirring at 60°C, and the reaction was continued at 60°C for 60 minutes while stirring. At this point, the polymerization conversion rate was 99.5% (the polymerization conversion rate was measured by gas chromatography; the same applies below).

[0135] Next, 50.0 parts of dehydrated isoprene were added, and stirring was continued at the same temperature for 30 minutes. At this point, the polymerization conversion rate was 99%. Subsequently, 25.0 parts of dehydrated styrene were added, and the mixture was stirred at the same temperature for 60 minutes. At this point, the polymerization conversion rate was approximately 100%. Next, 0.5 parts of isopropyl alcohol were added to the reaction mixture to stop the reaction and obtain solution (i) containing the block copolymer. The weight-average molecular weight (Mw) of the block copolymer in the obtained solution (i) was 44,900, and the molecular weight distribution (Mw / Mn) was 1.03.

[0136] Next, solution (i) was transferred to a pressure reactor equipped with a stirring device, and 4.0 parts of silica-alumina-supported nickel catalyst (E22U, nickel load 60%; manufactured by JGC Chemical Industries, Ltd.) and 350 parts of dehydrated cyclohexane were added to solution (i) as a hydrogenation catalyst and mixed. The reactor was purged with hydrogen gas, and hydrogen was supplied while stirring the solution, and the hydrogenation reaction was carried out at a temperature of 170°C and a pressure of 4.5 MPa for 6 hours to hydrogenate the block copolymer and obtain solution (iii) containing the hydride (ii) of the block copolymer. The weight-average molecular weight (Mw) of the hydride (ii) in solution (iii) was 45,100, and the molecular weight distribution (Mw / Mn) was 1.04.

[0137] After the hydrogenation reaction was complete, solution (iii) was filtered to remove the hydrogenation catalyst. Then, 1.0 part of a xylene solution containing 0.1 part of the phosphorus-based antioxidant 6-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetrakis-t-butyldibenzo[d,f][1.3.2]dioxaphosfepine (Sumitomo Chemical Co., Ltd., "SumiLizer® GP"; hereinafter referred to as "antioxidant A") was added to the filtered solution (iii) and dissolved to obtain solution (iv).

[0138] Next, solution (iv) was filtered through a ZetaPlus® filter 30H (manufactured by Quno, pore size 0.5 μm to 1 μm), and then sequentially filtered through another metal fiber filter (pore size 0.4 μm, manufactured by Nichidai) to remove minute solid particles. From the filtered solution (iv), the solvent cyclohexane, xylene, and other volatile components were removed using a cylindrical concentrate dryer (product name "Contro", manufactured by Hitachi, Ltd.) at a temperature of 260°C and a pressure of 0.001 MPa or less. The solid particles were then extruded in a molten state into strands from a die directly connected to the concentrate dryer, cooled, and cut with a pelletizer to obtain 85 parts of pellet (v) containing the hydride of the block copolymer and antioxidant A. The weight-average molecular weight (Mw) of the hydride of the block copolymer (hydrogenated block copolymer) in the obtained pellet (v) was 45,000, and the molecular weight distribution (Mw / Mn) was 1.08. Furthermore, the hydrogenation rate was 99.9%.

[0139] (Production of Silane-Modified Hydrogenated Block Copolymer) To 100 parts of pellets (v), 2.0 parts of vinyltrimethoxysilane and 0.2 part of di-t-butyl peroxide were added to obtain a mixture. This mixture was kneaded using a twin-screw extruder at a barrel temperature of 210 °C and a residence time of 80 to 90 seconds. The kneaded mixture was extruded and cut with a pelletizer to obtain pellets (vi) of a silane-modified hydrogenated block copolymer as a polymer (a) having a polar group containing a silicon atom. A film-shaped test piece was prepared from these pellets (vi), and when the glass transition temperature Tg was evaluated by the tanδ peak of a dynamic viscoelasticity measuring apparatus, it was 124 °C.

[0140] [Production Example 2: Production of Norbornene Polymer (b)] (Production of Norbornene Polymer) Into a dried and nitrogen-substituted polymerization reactor, 7 parts (1% based on the total amount of monomers used in the polymerization) of a monomer mixture consisting of 30 mol% of tricyclo[4.3.0.1 2,5 deca-3,7-diene (common name: dicyclopentadiene) (DCP), 26 mol% of 8-methyl-tetracyclo[4.4.0.1 2,5 .1 7,10 dodeca-3-ene (TCD), and 44 mol% of bicyclo[2.2.1]hept-2-ene (common name: norbornene) (NB), 1,600 parts of dehydrated cyclohexane, 3.0 parts of 1-hexene as a molecular weight regulator, 1.3 parts of diisopropyl ether, 0.33 part of isobutyl alcohol, 0.84 part of triisobutylaluminum, and 30 parts of a 0.66% cyclohexane solution of tungsten hexachloride were added and stirred at 55 °C for 10 minutes. Then, while maintaining the reaction system at 55 °C and stirring, 693 parts of the monomer mixture and 72 parts of a 0.77% cyclohexane solution of tungsten hexachloride were continuously dropped into the polymerization reactor over 150 minutes each. After further stirring for 30 minutes after the completion of the dropping, 1.0 part of isopropyl alcohol was added to stop the polymerization reaction. When the polymerization reaction solution was measured by gas chromatography, the conversion rate of the monomer to the polymer was 100%.

[0141] Next, 300 parts of the polymerization reaction solution containing the above polymer were transferred to an autoclave equipped with a stirrer, and 100 parts of cyclohexane and 2.0 parts of diatomaceous earth-supported nickel catalyst (manufactured by JGC Chemical Co., Ltd., product name "T8400RL", nickel load 58%) were added. After purging the autoclave with hydrogen, the reaction was carried out at 180°C and under a hydrogen pressure of 4.5 MPa for 6 hours. After the hydrogenation reaction was complete, diatomaceous earth (manufactured by Showa Chemical Industry Co., Ltd., product name "Radiolite® #500") was used as the filter bed, and the solution was filtered under pressure at 0.25 MPa using a pressure filter (manufactured by IHI Corporation, product name "Fundaback Filter") to obtain a colorless and transparent solution. Next, to the obtained solution, 0.5 parts of pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (manufactured by BASF Japan, product name "Irganox® 1010") was added as an antioxidant per 100 parts of the hydride and dissolved.

[0142] This solution was filtered through a filter (manufactured by Quno Filters, product name "Zeta Plus® 30H", pore size 0.5-1 μm), and the filtrate was filtered through a metal fiber filter (manufactured by Nichidai, pore size 0.4 μm) to remove foreign matter.

[0143] Next, the filtrate obtained above was used in a cylindrical concentrate dryer (manufactured by Hitachi, Ltd.) at a temperature of 260°C and a pressure of 1 kPa or less to remove the solvent cyclohexane and other volatile components from the solution. The molten material was then extruded in strand form from a die directly connected to the concentrate, and after water cooling, it was cut in a pelletizer (manufactured by Nagata Seisakusho, model "OSP-2") to obtain pellets of hydride of a ring-opening polymer containing an alicyclic structure. The hydrogenated product of this alicyclic structure-containing ring-opening polymer (norbornene polymer (b)) had a molecular weight of Mw=46,000, Mn=17,000, Mw / Mn=2.70, a hydrogenation rate of 99.9%, and a Tg of 70°C.

[0144] [Example 1] (1-1. Formation of the hard layer) Solution H1 for hard layer formation was prepared by mixing 21 parts of polymer (a) produced in Production Example 1, 9 parts of hydrogenated C9 petroleum resin "Alcon P140" (manufactured by Arakawa Chemical Industries, Ltd.), and 70 parts of ethylcyclohexane. The storage modulus of the hard layer obtained from this solution H1 at 25°C was 0.55 GPa. Next, this solution H1 was applied to a 50 μm thick glass film so that its thickness after drying would be 25 μm. The applied layer was dried on a hot plate at 110°C to obtain an intermediate laminate 1 having a layer structure of (hard layer) / (glass film). In the resin forming the hard layer, polymer (a) accounts for 70% by weight and hydrogenated C9 petroleum resin accounts for 30% by weight.

[0145] (1-2. Formation of the flexible layer) A solution S1 for forming a flexible layer was prepared by mixing 24 parts of polymer (a), 16 parts of polybutene (manufactured by NOF Corporation, number average molecular weight 1500) as a softener, and 60 parts of ethylcyclohexane. The storage modulus of the flexible layer obtained from this solution S1 at 25°C was 0.005 GPa. Next, this solution S1 was applied to a release PET film so that its thickness after drying was 25 μm, and the applied layer was dried on a hot plate at 110°C to obtain a laminated film 1 having a layer structure of (flexible layer) / (release PET film). In the resin forming the flexible layer, polymer (a) is 60% by weight and polybutene is 40% by weight.

[0146] (1-3. Fabrication of the laminate) The laminated film 1 and the intermediate laminate 1 were bonded together so that the rigid layer and the flexible layer faced each other, and the release PET film was peeled off to obtain a laminate (L1) having a layer structure of (flexible layer) / (rigid layer) / (glass thin film). A pendrop height test was performed on this laminate (L1), and no cracks occurred up to a height of 14 cm. In addition, haze measurement and a two-point bending test were performed on the laminate (L1).

[0147] [Example 2] (2-1. Formation of the hard layer) A hard layer-forming solution H2 was prepared by mixing 15 parts of polymer (a), 15 parts of hydrotalcite as a filler, and 70 parts of ethylcyclohexane. The volume-average particle size of the filler measured from this solution H2 was 120 nm. The storage modulus of the hard layer obtained from this solution H2 at 25°C was 0.61 GPa. Intermediate laminate 2 was obtained using hard layer forming solution H2 instead of hard layer forming solution H1, following the same procedure as in Example 1 (1-1). In the resin forming the hard layer, polymer (a) is 50% by weight and filler is 50% by weight.

[0148] (2-2. Formation of the flexible layer) Laminated film 1 was obtained by the same procedure as in Example (1-2).

[0149] (2-3. Fabrication of the laminate) Using the laminated film 1 and the intermediate laminate 2, a laminate (L2) having a layer structure of (flexible layer) / (hard layer) / (glass thin film) was obtained by following the same procedure as in (1-3) of Example 1. A pendrop height test was performed on this laminate (L2), and no cracks occurred up to a height of 16 cm. Furthermore, haze measurement and a two-point bending test were conducted on the laminate (L2).

[0150] [Example 3] (3-1. Formation of the hard layer) Solution H3 for hard layer formation was prepared by mixing 11.2 parts of polymer (a), 4.8 parts of hydrogenated C9 petroleum resin "Alcon P140" (manufactured by Arakawa Chemical Industries, Ltd.), 16 parts of hydrotalcite as a filler, and 68 parts of ethylcyclohexane. The volume-average particle size of the filler measured from solution H3 was 120 nm. The storage modulus of the hard layer obtained from solution H3 at 25°C was 0.75 GPa. Next, instead of hard layer forming solution H1, hard layer forming solution H3 was used to obtain intermediate laminate 3 in the same procedure as in Example 1 (1-1). In the resin forming the hard layer, polymer (a) was 35% by weight, hydrogenated C9 petroleum resin was 15% by weight, and filler was 50% by weight.

[0151] (3-2. Preparation of the flexible layer) A 25 μm thick optical transparent adhesive film (OCA film) S3 (Nitto Denko "CS9861US") was prepared as the flexible layer. The storage modulus of this optical transparent adhesive film at 25°C was 0.0004 GPa.

[0152] (3-3. Fabrication of Laminates) An optically transparent adhesive film S3 was bonded to the hard layer of the intermediate laminate 3 to obtain a laminate (L3) having a layer structure of (flexible layer) / (hard layer) / (glass thin film). A pendrop height test was performed on this laminate (L3), and no cracks occurred up to a height of 18 cm. Furthermore, haze measurement and a two-point bending test were conducted on the laminate (L3).

[0153] [Example 4] (4-1. Formation of the hard layer) Twenty parts of norbornene-based polymer (b) prepared in Production Example 2 and eighty parts of ethylcyclohexane were mixed to prepare hard layer formation solution H4. The storage modulus of the hard layer obtained from this solution H4 at 25°C was 1.6 GPa. Next, this solution H4 was applied to a 50 μm thick glass thin film so that its thickness after drying would be 10 μm. The applied layer was then dried on a hot plate at 110°C to obtain an intermediate laminate 4 having a layer structure of (hard layer) / (glass thin film).

[0154] (4-2. Formation of the flexible layer) A flexible layer-forming solution S1 was prepared in the same manner as in (1-2) of Example 1. The storage modulus of the flexible layer obtained from this solution S1 at 25°C was 0.005 GPa. Next, this solution S1 was applied to a release PET film so that its thickness after drying was 40 μm, and the applied layer was dried on a hot plate at 110°C to obtain a laminated film 4 having a layer structure of (flexible layer) / (release PET film). The laminated film 4 and the intermediate laminate 4 were bonded together so that the rigid layer and the flexible layer faced each other, and the release PET film was peeled off to obtain a laminate (L4) having a layer structure of (flexible layer) / (rigid layer) / (glass thin film). A pendrop height test was performed on this laminate (L4), and no cracks occurred up to a height of 12 cm. Furthermore, haze measurement and a two-point bending test were conducted on the laminate (L4).

[0155] [Comparative Example 1] (C1-1. Formation of the flexible layer) A flexible layer-forming solution S1 was prepared in the same manner as in (1-2) of Example 1. The storage modulus of the flexible layer obtained from this solution S1 at 25°C was 0.005 GPa. Next, this solution S1 was applied to a release PET film so that its thickness after drying was 50 μm, and the applied layer was dried on a hot plate at 110°C to obtain a laminated film C1 having a layer structure of (flexible layer) / (release PET film).

[0156] (C1-2. Fabrication of the laminate) A glass thin film with a thickness of 50 μm was prepared. A flexible layer was bonded to the glass thin film so that it was facing the flexible layer, and the release PET film was peeled off to obtain a laminate (CL1) having a layer structure of (flexible layer) / (glass thin film). A pendrop height test was performed on this laminate (CL1). No cracks occurred up to a height of 8 cm, but cracks occurred at a height of 9 cm. In addition, haze measurement and a two-point bending test were performed on the laminate (CL1).

[0157] [Comparative Example 2] (C2-1. Formation of the hard layer) A hard layer formation solution CH2 was prepared by mixing 30 parts of polymer (a) and 70 parts of ethylcyclohexane. The storage modulus of the hard layer obtained from this solution CH2 at 25°C was 0.21 GPa. Instead of the hard layer forming solution H1, the hard layer forming solution CH2 was used, and an intermediate laminate C2 was obtained by the same procedure as in (1-1) of Example 1.

[0158] (C2-2. Fabrication of the laminate) As the flexible layer, an optically transparent adhesive film S3 (Nitto Denko "CS9861US") with a thickness of 25 μm was prepared, similar to the flexible layer in Example 3. An optically transparent adhesive film S3 was bonded to the hard layer of the intermediate laminate C2 to obtain a laminate (CL2) having a layer structure of (flexible layer) / (hard layer) / (glass thin film). A pendrop height test was performed on this laminate (CL2). No cracks occurred up to a height of 8 cm, but cracks occurred at a height of 9 cm. In addition, haze measurement and a two-point bending test were performed on the laminate (CL2).

[0159] [Comparative Example 3] (C3-1. Formation of hard layers and laminates) A hard layer-forming solution CH2 was prepared in the same manner as in Comparative Example 2. The storage modulus of the hard layer obtained from this solution CH2 at 25°C was 0.21 GPa. Next, this solution CH2 was applied to a 50 μm thick glass so that the thickness after drying would be 50 μm. The applied layer was then dried on a hot plate at 110°C to obtain a laminate (CL3) having a layer structure of (hard layer) / (glass thin film). A two-point bending test was performed on this laminate (CL3). Before the radius of curvature R of the bending test specimen reached 3 mm, the glass thin film on the bending test specimen cracked and broke. In addition, haze measurements were performed on the laminate (CL3).

[0160] [result] The layer configurations and evaluation results of the examples and comparative examples are shown in the table below. In the table below, the abbreviations have the following meanings. "HPR": Hydrogenated C9 petroleum resin "PB": Polybutene "Polymer (a)": Polymer (a) having a polar group containing silicon atoms, manufactured in Manufacturing Example 1. "Polymer (b)": norbornene-based polymer (b) produced in Production Example 2. "CS9861": Nitto Denko's "CS9861US"

[0161] [Table 1]

[0162] [Table 2]

[0163] Based on the above results, the laminate according to the example has a pen drop test height (pen drop height) of 10 cm or more, exhibits excellent impact resistance, and has a "pass (A)" evaluation in the two-point bending test, indicating excellent flexural resistance. On the other hand, the laminate according to Comparative Example 2, in which the storage modulus of the hard layer at 25°C is less than 0.3 GPa, has a pendrop test height of less than 10 cm and exhibits inferior impact resistance. The laminate according to Comparative Example 1, which lacks a rigid layer, and the laminate according to Comparative Example 3, which lacks a flexible layer, both show poor evaluation in either the pendrop test height or the two-point bending test, and exhibit inferior bending resistance or impact resistance. [Explanation of symbols]

[0164] 100-layer structure 110 Glass thin film 110U main surface 120 hard layer 120D main surface 120U main surface 130 Flexible layer 130D main surface

Claims

1. A glass thin film having a thickness of 25 μm or more and 75 μm or less, A hard layer having a storage modulus of 0.3 GPa or more and 3 GPa or less at 25°C, A laminate comprising, in this order, a flexible layer having a storage modulus of 0.0001 GPa or more and 0.1 GPa or less at 25°C, and a flexible layer.

2. The laminate according to claim 1, wherein the glass thin film and the hard layer are in direct contact, and the hard layer and the flexible layer are in direct contact.

3. The laminate according to claim 1 or 2, wherein the hard layer comprises a thermoplastic resin containing a polymer having a group containing silicon atoms, or a thermoplastic resin containing an organosilicon compound.

4. The laminate according to claim 3, wherein the polymer having a silicon atom-containing group is a modified form of a hydrogenated aromatic vinyl compound-conjugated diene copolymer with a silicon atom-containing compound.

5. The laminate according to claim 3, wherein the organosilicon compound is a silane coupling agent.

6. The laminate according to any one of claims 1 to 5, wherein the hard layer includes a filler.

7. The laminate according to any one of claims 1 to 6, wherein the storage modulus of the hard layer at 50°C is 0.25 GPa or more and 3 GPa or less.

8. The laminate according to any one of claims 1 to 7, wherein the tanδ of the hard layer has a maximum value at 25°C or higher, where tanδ represents the ratio of the loss modulus to the storage modulus (loss modulus / storage modulus).

9. The laminate according to any one of claims 1 to 8, wherein the sum of the thickness of the hard layer and the thickness of the flexible layer is less than 100 μm.

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