Laminate

Abstract

To provide a laminate with excellent impact resistance in which a resin layer is laminated to a glass substrate.SOLUTION: The laminate is formed by laminating a resin layer with a storage modulus E1' of 10 to 1000 MPa at 20°C to a glass substrate with a thickness of 0.02 to 1 mm. In a test in which a steel ball with a weight of 225.6 g and a diameter of 38.1 mm is dropped on the glass substrate surface, the 50% fracture height is 300 mm or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a laminate formed by laminating resin layers. [Background technology]

[0002] In recent years, progress has been made in the field of displays, including liquid crystal displays and organic electroluminescence (EL) displays, to make them thinner and more flexible. Glass is used for these applications because of its excellent light transmittance, gas barrier properties, dimensional stability, hardness, etc., and thinner, high-performance glass is also available. However, when glass is thin, its impact resistance decreases and it is easily broken by an impact such as a drop or an external force during operation. Therefore, for example, Patent Document 1 proposes a method of laminating a resin film on the surface of a glass substrate to improve the impact resistance of glass. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-93401 Summary of the Invention [Problem to be solved by the invention]

[0004] However, although the laminate disclosed in Patent Document 1 has improved crack resistance (impact resistance), there is a problem in that the resin film is thick, at 50 μm or more, and the crack resistance of the laminate is also insufficient. An object of the present invention is to provide a laminate in which a resin layer is laminated on a glass substrate, and which has excellent impact resistance. [Means for solving the problem]

[0005] As a result of extensive research to solve the above problems, the inventors discovered that excellent impact resistance can be achieved by laminating a resin layer having specific physical properties on a glass substrate, and arrived at the present invention. That is, the gist of the present invention is as follows.

[0006] (1) A laminate in which a resin layer having a storage modulus E1' of 10 to 1000 MPa at 20°C is laminated on a glass substrate having a thickness of 0.02 to 1 mm, wherein the laminate has a 50% breaking height of 300 mm or more in a test in which a steel ball weighing 225.6 g and having a diameter of 38.1 mm is dropped onto the surface of the glass substrate. (2) The laminate according to (1), wherein the resin layer has a thickness of 1 to 50 μm. (3) The laminate according to (1) or (2), wherein the resin layer has a storage modulus E2' at 60° C. of 1 to 100 MPa. (4) The laminate according to any one of (1) to (3), wherein the resin layer contains an isocyanate compound, an epoxy compound, or an oxazoline compound. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a laminate in which a resin layer is laminated on a glass substrate, and which has excellent impact resistance. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will be described in detail below. The laminate of the present invention is a laminate in which a resin layer is laminated on a glass substrate, and the thickness of the glass substrate is in the range of 0.02 to 1 mm, the storage modulus E1' of the resin layer at 20°C is 10 to 1000 MPa, and in a test in which a steel ball weighing 225.6 g and having a diameter of 38.1 mm is dropped onto the surface of the glass substrate, the 50% breaking height is required to be 300 mm or more.

[0009] <Glass substrate> The glass substrate constituting the laminate of the present invention may be any plate-shaped material, and its material is not particularly limited, but examples thereof include soda-lime glass, borate glass, aluminosilicate glass, and quartz glass. Glasses are classified according to the alkali content, and include alkali-free glass and low-alkali glass. The content of alkali metal components (e.g., Na2O, KO, and Li2O) in the glass is preferably 15% by mass or less, and more preferably 10% by mass or less. The thickness of the glass substrate must be 0.02 to 1 mm, more preferably 0.03 to 0.7 mm, and even more preferably 0.05 to 0.5 mm. If the glass substrate is too thick, it may have poor flexibility, and if it is too thin, it may lack strength and be prone to breakage. The method for forming the glass substrate is not particularly limited, and examples thereof include melting a mixture containing a main raw material such as silica or alumina, an antifoaming agent such as mirabilite or antimony oxide, and a reducing agent such as carbon at 1400 to 1600°C, forming it into a plate, and then cooling it, and examples of methods include the slot downdraw method, the fusion method, and the float method. The glass substrate formed into a plate by these methods may be chemically polished with a solvent such as hydrofluoric acid, as necessary, to thin the plate or to improve its smoothness. The glass substrate may be a commercially available glass plate as it is, or a commercially available thin glass plate may be polished to a desired thickness. Examples of commercially available glass plates include Corning 7059, 1737, and EAGLE2000, Asahi Glass AN100, NH Techno Glass NA-35, Nippon Electric Glass OA-10 and T2X-1, Schott D263 and AF45, and Matsunami Glass cover glass and slide glass.

[0010] <Resin layer> The laminate of the present invention is obtained by laminating a resin layer on the glass substrate. The glass substrate may have a portion on which no resin layer is laminated, as long as the effect of the present invention is not impaired. The resin layer constituting the laminate must have a storage modulus (E1') of 10 to 1000 MPa at 20° C., preferably 20 to 200 MPa, and a storage modulus (E2') of 1 to 100 MPa, preferably 10 to 100 MPa, at 60° C. In a laminate in which a resin layer having a storage modulus in the above range is laminated on a glass substrate, impact stress is alleviated.

[0011] The resin layer having a storage modulus (E1') at 20°C of 10 to 1000 MPa can be constructed using a conventionally known resin. Examples of resins that can be used to construct the resin layer include vinyl acetate, vinyl acetate-vinyl chloride copolymer, polyvinyl butyral, polyolefin, polyamide, natural rubber, synthetic rubber, silicone rubber, polyester, phenol, epoxy, polyimide, acrylic, and cyanoacrylate, and these can also be used in combination. Among these, silicone, acrylic, and polyamide are preferred from the viewpoint of impact resistance, and it is particularly preferred that the resin layer that constitutes the laminate of the present invention contains an acrylic resin or a polyamide resin.

[0012] [Acrylic resin] Examples of components constituting the acrylic resin include conventionally known components, such as 2-ethylhexyl acrylate, butyl acrylate, methyl methacrylate, ethyl acrylate, methyl acrylate, benzyl acrylate, phenoxyethyl acrylate, vinyl acetate, acrylic acid, hydroxyethyl methacrylate, hydroxyethyl acrylate, glycidyl methacrylate, acetoacetoxyethyl methacrylate, etc. These components can be copolymerized or mixed and used according to the desired adhesiveness and thermal properties.

[0013] [Polyamide resin] The polyamide resin constituting the resin layer is preferably a dimer acid polyamide or a polyether ester polyamide. (dimer acid polyamide) Dimer acid polyamides have amide bonds in their main chains and are obtained mainly by dehydration condensation reactions using dimer acid as a dicarboxylic acid component and a diamine component. Compared to resins such as nylon 6, nylon 66, and nylon 12, which are widely used as polyamide resins, dimer acid polyamides have a larger hydrocarbon group and are therefore more flexible.

[0014] In the present invention, the dimer acid polyamide preferably contains dimer acid as a dicarboxylic acid component in an amount of 50 mol % or more, more preferably 60 mol % or more, and even more preferably 70 mol % or more of the total dicarboxylic acid components. If the proportion of dimer acid is less than 50 mol %, the resin layer will find it difficult to achieve the effects of the dimer acid polyamide. Here, dimer acid is obtained by dimerizing unsaturated fatty acids having 18 carbon atoms, such as oleic acid or linoleic acid, and may contain monomeric acid (18 carbon atoms), trimer acid (54 carbon atoms), or other polymerized fatty acids having 20 to 54 carbon atoms, as long as the dimer acid component accounts for 25% by mass or less, or may be hydrogenated to reduce the degree of unsaturation. Dimer acids are commercially available as the Haridimer series (manufactured by Harima Chemicals Co., Ltd.), Pripol series (manufactured by Croda Japan Co., Ltd.), Tsunodim series (manufactured by Tsuno Foods Industries Co., Ltd.), and the like, and these can be used.

[0015] When a component other than dimer acid is used as the dicarboxylic acid component of the dimer acid-based polyamide, it is preferable to use adipic acid, azelaic acid, sebacic acid, pimelic acid, suberic acid, nonanedicarboxylic acid, fumaric acid, etc., and by containing less than 50 mol% of these, it becomes easier to control the softening point and adhesiveness of the resin. Furthermore, as the diamine component of the dimer acid polyamide, ethylenediamine, hexamethylenediamine, tetramethylenediamine, pentamethylenediamine, m-xylenediamine, phenylenediamine, diethylenetriamine, piperazine, etc. can be used, and among these, ethylenediamine, hexamethylenediamine, diethylenetriamine, m-xylenediamine, and piperazine are preferred.

[0016] When polymerizing a dimer acid polyamide, it is possible to control the degree of polymerization and the acid value or amine value of the resin by changing the charging ratio of the dicarboxylic acid component and the diamine component. In the present invention, the amine value of the dimer acid polyamide is preferably less than 1.0 mgKOH / g, more preferably less than 0.7 mgKOH / g, and even more preferably less than 0.4 mgKOH / g. When a dimer acid polyamide having an amine value of 1.0 mgKOH / g or more is used, the heat resistance may decrease. The acid value of the dimer acid polyamide is preferably 1 to 20 mgKOH / g, more preferably 1 to 15 mgKOH / g, even more preferably 3 to 12 mgKOH / g, and most preferably 3 to 7 mgKOH / g. If the acid value of the dimer acid polyamide is less than 1 mgKOH / g, it becomes difficult to obtain a stable coating agent for forming a resin layer. On the other hand, if the acid value exceeds 20 mgKOH / g, the chemical resistance, which is an inherently good property of the dimer acid polyamide, may decrease. The acid value is defined as the number of milligrams of potassium hydroxide required to neutralize the acidic components contained in 1 g of resin. On the other hand, the amine value is expressed as the number of milligrams of potassium hydroxide that is the molar equivalent of the base components in 1 g of resin. Both are measured using the method specified in JIS K2501.

[0017] The softening point of the dimer acid polyamide is preferably 70 to 250°C, more preferably 80 to 240°C, and even more preferably 80 to 200°C. If the softening point is less than 70°C, the resulting resin layer tends to have low heat resistance and a high tackiness at room temperature. On the other hand, if the softening point is more than 250°C, not only does it tend to be difficult to prepare a resin layer-forming coating agent by dispersing the dimer acid polyamide in an aqueous medium, but the resulting coating agent may have insufficient resin fluidity when laminated on a glass substrate, and the laminated resin layer may not have sufficient adhesion to the glass substrate.

[0018] (Polyetherester polyamide) In the present invention, the polyetheresteramide constituting the resin layer is obtained by reacting a polyamide component with a polyetherester component consisting of polyoxyalkylene glycol and dicarboxylic acid, and is a block copolymer having an amide bond, an ether bond, and an ester bond in the molecular chain.

[0019] Specific examples of polyamide components constituting polyetheresteramides include polyamides produced from aliphatic, alicyclic, or aromatic diamines having 4 or more carbon atoms, such as tetramethylenediamine, hexamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, phenylenediamine, and xylylenediamines, and aliphatic, alicyclic, or aromatic dicarboxylic acids having 6 or more carbon atoms, such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, and polymerized fatty acids. Other examples include polyamides produced from aminocarboxylic acids having 6 or more carbon atoms, such as ω-aminocaproic acid, ω-aminoenanthic acid, ω-aminocaprylic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid, and polyamides produced from lactams having 6 or more carbon atoms, such as caprolactam, enantholactam, capryllactam, and laurolactam. Also included are copolymer polyamides of these, and mixed polyamides of these. In particular, polyamides produced from hexamethylenediamine and adipic acid, polyamides produced from hexamethylenediamine, polymerized fatty acid, and azelaic acid or sebacic acid, and polyamides produced from 12-aminododecanoic acid and caprolactam are preferred.

[0020] The polymerized fatty acid used is an unsaturated fatty acid obtained by polymerizing a monobasic fatty acid having one or more double or triple bonds and having 10 to 24 carbon atoms. Specific examples include dimers of oleic acid, linoleic acid, and erucic acid. Commercially available polymerized fatty acids typically contain dimerized fatty acids as the main component, with the raw fatty acids and trimerized fatty acids also present. The dimerized fatty acid content is preferably 70% by weight or more, and more preferably 95% by weight or more. If the dimerized fatty acid content is less than 70% by weight, the resulting polyamide tends to have a broad molecular weight distribution, making it difficult to adjust its properties. Furthermore, the polymerized fatty acid is preferably hydrogenated to reduce its degree of unsaturation. The lower the degree of unsaturation, the more resistant the resulting polyamide tends to be to oxidation and deterioration. In particular, commercially available polymerized fatty acids such as Pripol 1009, Pripol 1004, and Pripol 1010 (manufactured by Croda Japan) and Empol 1010 (manufactured by Henkel) are preferred, and mixtures of these may also be used.

[0021] Specific examples of the polyoxyalkylene glycol that constitutes the polyether ester component of the polyether ester amide include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, block or random copolymers of ethylene oxide and propylene oxide, block or random copolymers of ethylene oxide and tetrahydrofuran, and copolymers of dihydric phenol compounds and the above-mentioned polyoxyalkylene glycols.

[0022] The dicarboxylic acid constituting the polyetherester component of the polyetheresteramide is preferably a dicarboxylic acid having 6 to 20 carbon atoms, and specific examples thereof include aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid. In particular, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, and isophthalic acid are preferably used in terms of polymerizability and the physical properties of the polyetheresteramide.

[0023] The mass ratio (polyamide block / polyether ester block) in the polyether ester amide is preferably 95 / 5 to 20 / 80.

[0024] The polyetheresteramide preferably has a weight-average molecular weight of 5000 to 200000. If the weight-average molecular weight of the polyetheresteramide is less than 5000, it tends to be difficult to laminate a resin layer in the form of a film on the surface of a glass substrate, whereas if the weight-average molecular weight exceeds 200000, the solubility and compatibility in solvents decreases, making it difficult to prepare a coating agent for forming a resin layer, as described below.

[0025] The polyetheresteramide may be modified at its terminal with an amino group or a hydroxyl group, and the polar group at the terminal improves the adhesiveness of the polyetheresteramide.

[0026] Any method for producing polyether ester amide can be used as long as it can produce a uniform, high-molecular-weight polymer, for example, a method in which a polyamide oligomer is first synthesized, to which a polyoxyalkylene glycol and a dicarboxylic acid are added, and the mixture is heated under reduced pressure to achieve a high degree of polymerization.

[0027] As the polyetheresteramide, commercially available products can be suitably used, such as PA-200, PA-201, TPAE-12, TPAE-31, and TPAE-32 manufactured by T&K TOKA Corporation.

[0028] [Polyolefin resin] In the present invention, the polyolefin resin constituting the resin layer is preferably a polyolefin resin containing an unsaturated carboxylic acid component. The olefin component that is the main component of the polyolefin resin is not particularly limited, but is preferably an alkene having 2 to 6 carbon atoms, such as ethylene, propylene, isobutylene, 2-butene, 1-butene, 1-pentene, 1-hexene, or 4-methyl-1-pentene, and of these, ethylene and propylene are more preferred. A mixture of these may also be used. Furthermore, a copolymer of two or more types of polyolefin components may also be used. From the viewpoint of adhesiveness, the polyolefin resin preferably contains an unsaturated carboxylic acid component. Examples of the unsaturated carboxylic acid component include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, etc., as well as half esters and half amides of unsaturated dicarboxylic acids. Among these, from the viewpoint of even better adhesiveness, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferred, and acrylic acid and maleic anhydride are particularly preferred. As the polyolefin resin, commercially available products may be used, such as Arrowbase manufactured by Unitika Ltd., Hardlen manufactured by Toyobo Co., Ltd., and Auroren manufactured by Nippon Paper Industries Co., Ltd.

[0029] The thickness of the resin layer is preferably 1 to 50 μm, and more preferably 3 to 20 μm. When the thickness of the resin layer is in the above range, it is easy to obtain better impact resistance.

[0030] <Additives> In the present invention, the resin layer may contain additives such as a crosslinking agent, a tackifier, a filler, a surfactant, a pigment, an antioxidant, a flame retardant, and a silane coupling agent. The resin layer preferably contains a crosslinking agent from the viewpoint of improving cohesive strength and achieving a balance with the storage modulus. As the crosslinking agent, a conventionally known crosslinking agent can be used, such as an oxazoline compound, an isocyanate compound, a hydrazide compound, a carbodiimide compound, a melamine compound, a urea compound, an epoxy compound, or a compound having self-crosslinking properties or a compound having polyvalent coordination sites. These may be used alone or in combination. Among these, an isocyanate compound, an epoxy compound, or an oxazoline compound is more preferred.

[0031] Examples of the isocyanate compound include isocyanate monomers such as tolylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane diisocyanate, as well as adduct-type isocyanate compounds obtained by adding these isocyanate monomers to trimethylolpropane or the like; isocyanurates, biuret-type compounds, and urethane prepolymer-type isocyanates obtained by addition reaction of known polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, etc. These may be used alone or in combination of two or more.

[0032] Examples of epoxy compounds include sorbitol polyglycidyl ether, diglycerol polyglycidyl ether, bisphenol A diglycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, resorcinol diglycidyl ether, isosorbide diglycidyl ether, isomannide diglycidyl ether, isoidite diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, cresol novolac polyglycidyl ether, etc. These may be used alone or in combination of two or more. The number of epoxy groups that the epoxy compound has in one molecule is preferably 2 to 15, more preferably 2 to 10, and even more preferably 2 to 6. The epoxy equivalent of the epoxy compound is not particularly limited, but is preferably 100 to 1,000, and more preferably 120 to 700. In the present invention, commercially available crosslinking agents may be used as the epoxy compound because they are easily available. Specific examples include the Denacol series (EX-211, EX-212, EX-313, EX-314, EX-411, EX-421, EX-512, EX-521, EX-611, EX-612, EX-614, EX-614B, EX-622, EX-810, EX-811, EX-850, EX-851, EX-821, EX-830, EX-832, EX-841, EX-861, EX-911, EX-941, and EX-920) manufactured by Nagase Chemtec Corporation.

[0033] As the oxazoline compound, for example, commercially available products such as the Epocross series (WS-500, WS-700, K-1010E, K-1020E, K-1030E, K-2010E, K-2020E, K-2030E, RPS-1005) manufactured by Nippon Shokubai Co., Ltd. can be used.

[0034] <Method of manufacturing laminate> Next, a method for manufacturing the laminate will be described. The laminate of the present invention can be produced by laminating a resin layer on the surface of a glass substrate. Examples of methods for laminating a resin layer include a coating method in which a coating agent in which the resin constituting the resin layer is dissolved or dispersed is applied to the surface of a glass substrate and then dried, a method in which the resin constituting the resin layer is heat-melted on the surface of a glass substrate and extrusion-coated, and a method in which a resin layer previously formed on a process film such as a release film is attached to the surface of the glass substrate and transferred. Among these, the coating method is preferred from the viewpoint of facilitating the formation of a uniform, thin resin layer.

[0035] (Coating agent for forming resin layer) The resin layer-forming coating agent is a solution or dispersion of the resin constituting the resin layer in a medium. Examples of the medium include alcohols such as water, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, and cyclohexanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, and isophorone; ethers such as tetrahydrofuran and dioxane; esters such as ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, ethyl propionate, diethyl carbonate, and dimethyl carbonate; ethylene glycol, ethylene glycol monomethyl ether, and the like. Examples of suitable solvents include glycol derivatives such as ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monobutyl ether, and propylene glycol methyl ether acetate; and further examples include 3-methoxy-3-methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate, toluene, xylene, and cyclohexane, and these solvents may be used in combination as needed.

[0036] The resin content (solids concentration) in the resin layer-forming coating agent can be appropriately selected depending on the intended use, storage method, etc., and is not particularly limited, but is preferably 3 to 40 mass %, and more preferably 10 to 35 mass %. If the resin content in the resin layer-forming coating agent is less than the above range, it may take a long time to form a coating film by the drying process, and it tends to be difficult to obtain a thick coating film. On the other hand, if the resin content in the resin layer-forming coating agent is more than the above range, the storage stability of the coating agent tends to be reduced.

[0037] The viscosity of the resin layer-forming coating agent is not particularly limited, but it is preferably low even at room temperature. Specifically, the rotational viscosity measured at 20°C using a B-type viscometer (Tokimec Co., Ltd., DVL-BII digital viscometer) is preferably 20,000 mPa·s or less, more preferably 5,000 mPa·s or less, and even more preferably 1,000 mPa·s or less. If the viscosity of the resin layer-forming coating agent exceeds 20,000 mPa·s, it tends to become difficult to apply the coating agent uniformly to the glass substrate.

[0038] <Characteristics of laminate> The laminate of the present invention is required to have impact resistance such that the 50% breaking height is 300 mm or more in a steel ball drop test. More specifically, as described below, in a test in which a steel ball weighing 225.6 g and having a diameter of 38.1 mm is dropped onto the surface of a glass substrate at various heights, the steel ball drop height at which 50% of the glass substrate breaks must be 300 mm or more, more preferably 400 mm or more, and particularly preferably 700 mm or more.

[0039] <Use of laminates> The laminate of the present invention has excellent impact resistance and transparency, and therefore can be used in a variety of applications including displays such as liquid crystal displays and organic LEDs, and examples thereof include solar cell substrates and sensors. [Example]

[0040] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples. 1. Evaluation Method The properties of the laminate were measured and evaluated by the following methods. 1-1 Storage modulus and temperature dependence of resin layer The resin layer-forming coating material was applied to a polyethylene terephthalate film (Emblet S-50, manufactured by Unitika Ltd.) so that the thickness of the coating film after drying would be approximately 0.3 mm, and then dried on a hot plate. The resulting coating film was then peeled off from the film and cut into a 40 mm × 4 mm × 0.3 mm sample for evaluating the storage modulus. Then, using a dynamic viscoelasticity measuring device (TA Instruments, RSA-G2 DMA), the storage modulus at 20°C (E1') and the storage modulus at 60°C (E2') were measured under the following conditions: chuck distance: 20 mm, temperature range: -25 to 150°C, heating rate: 5°C / min, strain: 0.1%, and frequency: 1 Hz. The temperature dependence of viscoelastic properties was evaluated by calculating the ratio (E2' / E1') of the storage modulus at 60°C (E2') to the storage modulus at 20°C (E1'). From a practical standpoint, a ratio of the storage modulus at 60°C of 50% or more was considered to be preferable because it has little temperature dependence.

[0041] 1-2 Impact resistance A laminate sample (50 mm long x 50 mm wide) was placed with the glass substrate side facing up, and a stainless steel plate (1.5 mm thick, SUS304, manufactured by Nippon Test Panel Co., Ltd.) was placed under the resin layer. A steel ball weighing 225.6 g and measuring 38.1 mm in diameter was dropped onto the glass substrate surface from various drop heights, and the height at which 10 samples either broke or did not break (standard drop height H) was determined. Based on the DuPont impact strength measurement method of JIS K 5400, a steel ball was dropped from a standard drop height H to determine whether or not the glass substrate was broken. If breakage was observed in the glass substrate, the drop height of the steel ball was reduced by one level and the test was repeated. If breakage was not observed in the glass substrate, the drop height of the steel ball was increased by one level and the test was repeated. The drop test was repeated a total of 20 times, and the 50% break height (H) was calculated using the following formula: 50 The change interval d for each level was 50 mm. H 50 =H+d(Σ(i-ni) / N-1 / 2) H = Standard drop height (mm) d = height change interval (mm) i = number of levels (...3, 2, 1, 0, -1, -2, -3...) ni = number of times failure occurred at each level N = total number of times destruction occurred (=Σni)

[0042] 2.Material The following materials were used to prepare the laminate: 2-1 Glass substrate The following glass substrates were used: [G-1] Matsunami Glass Industry Co., Ltd., cover glass No. 1, size 50mm x 70mm, thickness approximately 0.15mm (0.13mm - 0.17mm) [G-2] AS ONE Corporation, square glass plate, soda glass, size 50mm x 50mm, thickness 1mm [G-3] Nippon Electric Glass Co., Ltd., OA-10G, size 50mm x 50mm, thickness 0.05mm [G-4] AS ONE Corporation, square glass plate, soda glass, size 50mm x 50mm, thickness 2mm [G-5] Square glass plate, soda glass, size 50mm x 50mm, thickness 0.015mm [G-6] Square glass plate, soda glass, size 50mm x 50mm, thickness 0.02mm

[0043] 2-2 Resin layer A resin solution constituting a resin layer-forming coating agent for forming a resin layer was prepared by the following method. [Acrylic resin solution P-1] A four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser was charged with a monomer mixture containing 91.8 parts by weight of n-butyl acrylate, 6 parts by weight of methyl methacrylate, 1.5 parts by weight of N-vinylpyrrolidone, 0.2 parts by weight of acrylic acid, and 0.5 parts by weight of 4-hydroxybutyl acrylate. Furthermore, 0.15 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator was charged together with ethyl acetate per 100 parts by weight of the monomer mixture (solid content). Nitrogen gas was introduced with gentle stirring to replace the atmosphere, and the liquid temperature in the flask was maintained at around 60°C for 7 hours to carry out the polymerization reaction. Ethyl acetate was then added to the resulting reaction solution to a solids concentration of 20% by weight, yielding acrylic resin solution P-1.

[0044] [Dimer acid polyamide resin solution P-2] The dimer acid polyamide resin used was a polyamide resin whose dicarboxylic acid component contained 100 mol% dimer acid, whose diamine component contained 100 mol% ethylenediamine, and whose acid value was 10.0 mgKOH / g, amine value was 0.1 mgKOH / g, and softening point was 158° C. This was dissolved in a 1 / 1 mixed solvent of toluene and methanol to give a solids concentration of 15% by mass, to obtain dimer acid polyamide resin solution P-2.

[0045] [Polyetheresteramide resin solution P-3] Polyetheresteramide "TPAE-32" manufactured by T&K TOKA Corporation was used as the polyetheresteramide, and was dissolved in a mixed solvent of toluene / methanol = 1 / 1 so that the solid content concentration was 15 mass %, to obtain polyetheresteramide resin solution P-3.

[0046] [Polyolefin resin aqueous dispersion P-4] Bondine LX4110 manufactured by Arkema was used as the polyolefin resin. A 1-liter, sealable, pressure-resistant glass vessel equipped with a stirrer and heater was charged with 60.0 g of polyolefin resin, 28.0 g of IPA, 1.5 g of triethylamine, and 210.5 g of distilled water. The mixture was stirred at 300 rpm with an impeller. No precipitation of resin particles was observed at the bottom of the vessel; the resin particles remained suspended in the water. After 10 minutes of stirring, the heater was turned on and the vessel was heated. The system temperature was maintained at 140°C and the mixture was stirred for another 20 minutes. The mixture was then placed in a water bath and cooled to room temperature (approximately 25°C) while stirring at 300 rpm. It was then filtered under pressure (0.2 MPa air pressure) through a 300-mesh stainless steel filter (0.035 mm wire diameter, plain weave) to obtain a milky-white, uniform aqueous polyolefin resin dispersion, P-4. The solids concentration of P-4 was 20% by mass, and the viscosity was 70 mPa·s.

[0047] [Acrylic resin solution P-5] In the preparation of the acrylic resin solution P-1, the monomer composition was changed to 100 parts by mass of 4-hydroxybutyl acrylate, and the polymerization conditions were adjusted. An acrylic polymer solution was prepared in the same manner as in the preparation of the acrylic resin solution P-1, thereby obtaining acrylic resin solution P-5.

[0048] The following crosslinking agents were used to form the resin layer-forming coating agent. [C-1] Epoxy compound (Nagase Chemtec Corporation, Denacol EX-512, solid content 100% by mass) [C-2] Oxazoline compound (Nippon Shokubai Co., Ltd., Epocross RPS-1005, solid content 100% by mass) [C-3] Isocyanate compound (Mitsui Chemicals, Takenate D160N, solid content 75% by mass)

[0049] Example 1 The acrylic resin solution P-1 and the crosslinking agent (C-1, epoxy compound) were mixed so that the solid content of each was 100 parts by mass / 20 parts by mass, and the mixture was stirred at room temperature for 5 minutes to obtain a coating agent for forming a resin layer. The obtained coating material was applied to a glass substrate G-1 so that the thickness after drying would be 10 μm, and dried at 150° C. for 30 seconds to form a resin layer, thereby obtaining a laminate.

[0050] Examples 2 to 12 (Example 9 is a reference example) , Comparative Examples 1 to 5 A laminate was obtained in the same manner as in Example 1, except that the type of glass substrate and the composition of the resin layer-forming coating agent were changed as shown in Table 1. In Comparative Example 1, the impact resistance of glass substrate G-1 was evaluated without laminating a resin layer.

[0051] Table 1 shows the configurations and properties of the laminates of the examples and comparative examples.

[0052] [Table 1]

[0053] The glass substrates of the laminates of the Examples had excellent impact resistance, with a 50% breaking height of 300 mm or more. On the other hand, Comparative Example 1 was a glass substrate without a resin layer laminated thereon, and Comparative Examples 2 and 3 had glass substrate thicknesses outside the range of 0.02 to 1 mm, and Comparative Examples 4 and 5 had resin layer storage moduli outside the range of 10 to 1000 MPa at 20°C, so none of them provided sufficient impact resistance.

Claims

1. A laminate comprising a glass substrate having a thickness of 0.02 to 1 mm and a resin layer comprising at least one selected from the following crosslinked resins (1) to (4), the resin layer having a storage modulus E1' at 20°C of 10 to 1000 MPa, wherein the laminate has a 50% breaking height of 400 mm or more in a test in which a steel ball weighing 225.6 g and having a diameter of 38.1 mm is dropped onto the surface of the glass substrate. Crosslinked resin (1): A crosslinked resin obtained by crosslinking an acrylic resin with an oxazoline compound. Crosslinked resin (2): A crosslinked resin obtained by crosslinking an acrylic resin containing N-vinylpyrrolidone and acrylic acid as constituent components with at least one compound selected from an isocyanate compound, an epoxy compound, and an oxazoline compound. Crosslinked resin (3): A crosslinked resin obtained by crosslinking a polyamide resin with at least one compound selected from an isocyanate compound, an epoxy compound, and an oxazoline compound. Crosslinked resin (4): A crosslinked resin obtained by crosslinking a polyolefin resin containing an unsaturated carboxylic acid component with at least one compound selected from an isocyanate compound, an epoxy compound, and an oxazoline compound.

2. 2. The laminate according to claim 1, wherein the resin layer has a thickness of 1 to 50 μm.

3. 3. The laminate according to claim 1, wherein the resin layer has a storage modulus E2' at 60° C. of 1 to 100 MPa.

4. A laminate described in any one of claims 1 to 3, wherein the resin layer contains the following crosslinked resin (3') and has a storage modulus E1' at 20°C of 10 to 1000 MPa. Crosslinked resin (3'): A crosslinked resin obtained by crosslinking a dimer acid polyamide resin or a polyether ester polyamide resin with at least one compound selected from an isocyanate compound, an epoxy compound, and an oxazoline compound.

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