Laminate

Abstract

To provide a laminate that contains a transparent base material and has excellent transparency and also excellent impact resistance.SOLUTION: Provided is a laminate in which, characterized, a transparent substrate, an adhesive layer and a semi-aromatic polyamide resin film are laminated in this order, and the adhesive strength between the transparent substrate and the semi-aromatic polyamide resin film is 4 N / 10 mm or more.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a laminate formed by laminating a transparent substrate.

Background Art

[0002] In recent years, in the field of displays such as liquid crystal displays and organic EL displays, thinning and flexibility have been promoted. Glass has excellent light transmittance, gas barrier properties, dimensional stability, hardness, etc., and is used in these applications, and even thinner and higher-performance glass is also provided. However, when glass is thin, its impact resistance decreases, and it is easily cracked by impacts such as dropping or external forces during operation. Therefore, in order to improve the impact resistance of glass, for example, a laminate in which a protective film or the like is attached to the glass has been proposed.

Prior Art Documents

Patent Documents

[0003] Patent Document 1: International Publication No. 2017 / 105908 Patent Document 2: Japanese Unexamined Patent Application Publication No. 2020-20960

Summary of the Invention

Problems to be Solved by the Invention

[0004] Although the laminates disclosed in Patent Documents 1 and 2 have improved scratch resistance and bendability tests by attaching a protective film with excellent transparency to the surface of the glass, there is a problem that the thickness of the protective film is as thick as 100 μm or more, and the impact resistance when an impact is applied to the surface has not been evaluated. In addition, problems such as affecting the operability and the appearance of the screen by attaching the protective film have also been pointed out.

[0005] An object of the present invention is to provide a laminate including a transparent substrate, which has excellent transparency and excellent impact resistance.

Means for Solving the Problems

[0006] As a result of investigations to solve the above problems, the present inventors have found that when a transparent substrate such as glass is laminated on a semi-aromatic polyamide resin film with a specific adhesive strength through an adhesive layer, it has excellent impact resistance, and thus arrived at the present invention. That is, the gist of the present invention is as follows.

[0007] (1) A laminate in which a transparent substrate, an adhesive layer, and a semi-aromatic polyamide resin film are laminated in this order, The transparent substrate is glass, wherein the adhesive strength between the transparent substrate and the semi-aromatic polyamide resin film is 4 N / 10 mm or more. (2) The laminate according to (1), wherein in a test of dropping a steel ball weighing 225.6 g and having a diameter of 38.1 mm onto the transparent substrate, the 50% fracture height is 400 mm or more. (3) The laminate according to (1) or (2), wherein the adhesive layer contains an acrylic adhesive. (4) The laminate according to (3), wherein the thickness of the adhesive layer is 10 to 50 μm. (5) The laminate according to (1) or (2), wherein the adhesive layer contains a polyamide resin. (6) The laminate according to (5), wherein the adhesive layer contains a crosslinking agent. (7) The laminate according to (5) or (6), wherein the thickness of the adhesive layer is 3 to 20 μm 。 (8 ) A laminate according to any one of (1) to ([ 7 ) wherein an easy-adhesion layer is laminated between the adhesive layer and the semi-aromatic polyamide resin film. [Advantages of the Invention]

[0008] According to the present invention, it is possible to provide a laminate in which a transparent substrate such as glass is laminated on the surface, and which has excellent impact resistance and transparency. [Embodiments for Carrying Out the Invention]

[0009] Hereinafter, the present invention will be described in detail. In the laminate of the present invention, a transparent substrate, an adhesive layer, and a semi-aromatic polyamide resin film are laminated in this order, and the adhesive strength between the transparent substrate and the semi-aromatic polyamide resin film needs to be 4 N / 10 mm or more.

[0010] <Transparent substrate> The transparent substrate constituting the laminate of the present invention may be any transparent substrate, and its material is not particularly limited. For example, glass, a transparent resin film, etc. can be mentioned.

[0011] The glass may be in a plate shape, and its material is not particularly limited. For example, soda lime glass, borate glass, aluminosilicate glass, quartz glass, etc. can be mentioned. Also, according to the classification by the alkali component, alkali-free glass and low-alkali glass can be mentioned. The content of the alkali metal component (for example, Na2O, K2O, Li2O) of the above glass is preferably 15% by mass or less, and more preferably 10% by mass or less. The thickness of the glass plate is preferably 1 to 300 μm, more preferably 5 to 150 μm, still more preferably 15 to 100 μm, and particularly preferably 20 to 50 μm. If the glass is too thick, it may be inferior in flexibility, and if it is too thin, the strength may be insufficient and it may be easily broken. The forming method of the glass plate is not particularly limited. For example, a mixture containing main raw materials such as silica and alumina, defoaming agents such as sodium sulfate and antimony oxide, and reducing agents such as carbon is melted at 1400 to 1600 °C, formed into a plate shape, and then cooled to be produced. For example, the slot down draw method, the fusion method, the float method, etc. can be mentioned. The glass formed into a plate shape by these methods may be chemically polished with a solvent such as hydrofluoric acid as necessary to make it thinner or improve its smoothness. The glass plate may be a commercially available one used as it is, or a commercially available thin glass plate may be polished to a desired thickness before use. Examples of commercially available glass plates include Corning 7059, 1737, EAGLE 2000, Asahi Glass AN100, NH Techno Glass NA-35, Nippon Electric Glass OA-10, T2X-1, Schott D263, AF45, Matsunami Glass Cover Glass, Slide Glass, etc.

[0012] As the transparent resin film substrate, various resin films having transparency can be used, and there is no particular limitation. For example, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, etc. can be mentioned. Among these, particularly preferred are films of polyester resins, polyimide resins, and polyethersulfone resins. The thickness of the film substrate is preferably 15 to 200 μm.

[0013] A functional layer may be laminated on the surface of the transparent substrate. For example, a hard coat layer, a conductive layer, an adhesive layer, a barrier layer, an antireflection layer, an antiglare layer, a polarizing layer, an antifouling layer, an antistatic layer, a hydrophilic layer, a water repellent layer, an oil repellent layer, an ultraviolet absorption layer, an infrared absorption layer, a printing layer, etc. can be mentioned.

[0014] <Adhesive layer> In the laminate of the present invention, an adhesive layer is laminated between the above transparent substrate and the semi-aromatic polyamide resin film. As the material constituting the adhesive layer, conventionally known materials can be used. For example, vinyl acetate, vinyl acetate-vinyl chloride copolymer, polyvinyl butyral, polyolefin, polyamide, natural rubber, synthetic rubber, silicone rubber, polyurethane, polyester, phenol, epoxy, polyimide, acrylic, cyanoacrylate, etc. can be mentioned. Among them, from the viewpoints of adhesiveness, transparency, and durability, urethane, silicone, acrylic, and polyamide are preferable, and the adhesive layer constituting the laminate of the present invention preferably contains an acrylic adhesive and a polyamide resin in particular.

[0015] 〔Acrylic Adhesive〕 As an example of the acrylic adhesive, an adhesive excellent in transparency called OCA (OPTICAL CLEAR ADHESIVE), which has been conventionally used when laminating members for displays, can be mentioned. From the viewpoints of heat resistance, transparency, and stability, it is preferable to use this adhesive. As components constituting the acrylic adhesive, conventionally known ones can be mentioned. For example, 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. can be mentioned. Such components can be copolymerized or mixed and used according to the desired adhesiveness and thermal properties.

[0016] When the adhesive layer contains an acrylic adhesive, the thickness is preferably 10 to 50 μm, more preferably 10 to 40 μm, and even more preferably 15 to 35 μm. When the thickness of the adhesive layer is within this range, it is easier to obtain more excellent impact resistance.

[0017] 〔Polyamide Resin〕 The polyamide resin constituting the adhesive layer is preferably a dimer acid-based polyamide or a polyether ester polyamide. (Dimer acid-based polyamide) Dimer acid-based polyamide has an amide bond in the main chain and is obtained mainly by a dehydration condensation reaction using dimer acid as a dicarboxylic acid component and a diamine component. Compared with resins such as nylon 6, nylon 66, and nylon 12 that are widely used as polyamide resins, dimer acid-based polyamide has a large hydrocarbon group and thus has flexibility.

[0018] In the present invention, the dimer acid-based polyamide preferably contains 50 mol% or more, more preferably 60 mol% or more, and still more preferably 70 mol% or more of dimer acid as the dicarboxylic acid component based on the total amount of the dicarboxylic acid components. When the proportion of dimer acid is less than 50 mol%, it becomes difficult for the adhesive layer to exhibit the effects of the dimer acid-based polyamide. Here, dimer acid is obtained by dimerizing unsaturated fatty acids having 18 carbon atoms such as oleic acid and linolenic acid. If it is 25 mass% or less of the dimer acid component, it may contain monomeric monomeric acid (18 carbon atoms), trimeric trimeric acid (54 carbon atoms), and other polymerized fatty acids having 20 to 54 carbon atoms, and may also be hydrogenated to reduce the degree of unsaturation. Dimer acid is commercially available as the Haridimer series (manufactured by Harima Chemicals, Inc.), the Prepole series (manufactured by Croda Japan Co., Ltd.), the Tsunodime series (manufactured by Tsukino Food Industry Co., Ltd.), etc., and these can be used.

[0019] When using a component other than dimer acid 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. By containing these in less than 50 mol%, it becomes easy to control the softening point and adhesiveness of the resin. In addition, as the diamine component of the dimer acid-based polyamide, ethylenediamine, hexamethylenediamine, tetramethylenediamine, pentamethylenediamine, m-xylenediamine, phenylenediamine, diethylenetriamine, piperazine, etc. can be used. Among them, ethylenediamine, hexamethylenediamine, diethylenetriamine, m-xylenediamine, and piperazine are preferred.

[0020] When polymerizing the dimer acid-based polyamide, it becomes possible to control the degree of polymerization, acid value, or amine value of the resin by changing the charging ratio of the above dicarboxylic acid component and diamine component. In the present invention, the amine value of the dimer acid-based 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-based polyamide having an amine value of 1.0 mgKOH / g or more is used, the heat resistance may decrease. Also, the acid value of the dimer acid-based 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-based polyamide is less than 1 mgKOH / g, it becomes difficult to obtain a stable coating agent for forming the adhesive layer. On the other hand, if it exceeds 20 mgKOH / g, the chemical resistance, which is a good property of the original dimer acid-based 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 the resin. On the other hand, the amine value is represented by the number of milligrams of potassium hydroxide that is equivalent to the molar amount of the basic components in 1 g of the resin. Both are measured by the method described in JIS K2501.

[0021] The softening point of the dimer acid-based polyamide is preferably from 70 to 250°C, more preferably from 80 to 240°C, and even more preferably from 80 to 200°C. When the softening point is less than 70°C, the resulting adhesive layer tends to have low heat resistance and high tackiness at room temperature. On the other hand, when the softening point exceeds 250°C, not only does it tend to be difficult to disperse the dimer acid-based polyamide in an aqueous medium to prepare a coating agent for forming an adhesive layer, but the resulting adhesive layer may have insufficient resin fluidity during adhesion, and sufficient adhesiveness may not be obtained.

[0022] (Polyether ester polyamide) In the present invention, the polyether ester amide constituting the adhesive layer is obtained by the reaction of a polyamide component and a polyether ester component composed 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.

[0023] Specific examples of the polyamide component constituting the polyether ester amide 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. In addition, 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, enanthlactam, capryllactam, and laurolactam can be mentioned. Further, these copolyamides, or mixed polyamides thereof, etc. can be mentioned. 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 preferable.

[0024] As the above polymerized fatty acid, a polymerized fatty acid obtained by polymerizing an unsaturated fatty acid, for example, a monobasic fatty acid having one or more double bonds or triple bonds with 10 to 24 carbon atoms, is used. Specific examples include dimers such as oleic acid, linoleic acid, and erucic acid. Commercially available polymerized fatty acids usually have dimerized fatty acids as the main component and contain other raw material fatty acids and trimerized fatty acids. However, the content of dimerized fatty acids is preferably 70% by weight or more, and more preferably 95% by weight or more. When the content of dimerized fatty acids is less than 70% by weight, the molecular weight distribution of the resulting polyamide tends to become wide, making it difficult to adjust the properties of the polyamide. Further, the above polymerized fatty acid is preferably hydrogenated to reduce the degree of unsaturation. The lower the degree of unsaturation, the less likely the resulting polyamide is to be oxidized and deteriorated. In particular, as commercially available products of polymerized fatty acids, Prepol 1009, Prepol 1004, Prepol 1010 (manufactured by Croda Japan), Empol 1010 (manufactured by Henkel), etc. are preferable, and mixtures of these may also be used.

[0025] As the polyoxyalkylene glycol constituting the polyether ester component of the polyether ester amide, specifically, polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, a block or random copolymer of ethylene oxide and propylene oxide, a block or random copolymer of ethylene oxide and tetrahydrofuran, and a copolymer of a divalent phenol compound and the above polyoxyalkylene glycol, etc. may be mentioned.

[0026] As the dicarboxylic acid constituting the polyether ester component of the polyether ester amide, a dicarboxylic acid having 6 to 20 carbon atoms is preferable, and specifically, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, alicyclic dicarboxylic acids such as 1,4 - cyclohexanedicarboxylic acid, etc. may be mentioned. In particular, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, and isophthalic acid are preferably used from the viewpoints of polymerizability and physical properties of the polyether ester amide.

[0027] The mass ratio (polyamide block / polyether ester block) in the polyether ester amide is preferably 95 / 5 to 20 / 80.

[0028] The polyether ester amide preferably has a weight - average molecular weight of 5000 to 200000. When the weight - average molecular weight of the polyether ester amide is less than 5000, it tends to be difficult to form an adhesive layer in a film form on the semi - aromatic polyamide resin film surface. When the weight - average molecular weight exceeds 200000, the solubility and compatibility in a solvent decrease, and it tends to be difficult to prepare a coating agent for forming an adhesive layer described later.

[0029] The polyether ester amide may have its terminal modified by an amino group or a hydroxyl group. The adhesiveness of the polyether ester amide is improved by the polar group at the terminal.

[0030] As a method for producing a polyetheresteramide, any method can be adopted as long as it can obtain a uniform and high-molecular-weight polymer. For example, a method of first synthesizing a polyamide oligomer, adding a polyoxyalkylene glycol and a dicarboxylic acid thereto, and heating under reduced pressure to increase the degree of polymerization can be mentioned.

[0031] As the polyetheresteramide, commercially available products can be preferably used. Examples of such commercially available products include PA-200, PA-201, TPAE-12, TPAE-31, TPAE-32, etc. manufactured by T&K TOKA.

[0032] When the adhesive layer contains a polyamide-based resin, the thickness is preferably 3 to 20 μm, and more preferably 5 to 10 μm. When the thickness of the adhesive layer is within the above range, it is easier to obtain more excellent adhesiveness and impact resistance.

[0033] [Polyolefin resin] The polyolefin resin constituting the adhesive layer is preferably a polyolefin containing an unsaturated carboxylic acid component. The olefin component, which is the main component of the polyolefin resin, is not particularly limited, but alkenes having 2 to 6 carbon atoms such as ethylene, propylene, isobutylene, 2-butene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, etc. are preferable, and among them, ethylene and propylene are more preferable. These mixtures may also be used. In addition, those in which two or more kinds of polyolefin components are copolymerized may 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., and half esters and half amides of unsaturated dicarboxylic acids. Among them, from the viewpoint of further excellent adhesiveness, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferable, and acrylic acid and maleic anhydride are particularly preferable. As the polyolefin resin, commercially available products may be used. For example, Aron Base manufactured by Unitika Ltd., Hardlen manufactured by Toyobo Co., Ltd., Auroren manufactured by Nippon Paper Industries Co., Ltd., etc. can be mentioned.

[0034] [Polyurethane resin] The polyurethane-based resin constituting the adhesive layer is not particularly limited, and various polyurethane resins such as polyester-based urethane resins, polyether-based urethane resins, and polycarbonate-based urethane resins can be mentioned. As the polyurethane-based resin, commercially available products may be used. For example, Takelac, Takenate manufactured by Mitsui Chemicals, Inc., Barnock, Hydran manufactured by DIC Corporation, etc. can be mentioned.

[0035] In the present invention, the adhesive layer may contain additives such as a crosslinking agent, tackifier, filler, surfactant, pigment, antioxidant, flame retardant, and silane coupling agent. The crosslinking agent is preferably contained in the adhesive layer from the viewpoints of improving cohesive force and heat resistance. As the crosslinking agent, conventionally known ones can be contained, and examples thereof include isocyanate compounds, epoxy compounds, oxazoline compounds, metal chelate-based compounds, and melamine compounds. The tackifier is for the purpose of improving adhesiveness and is preferably contained in the adhesive layer. As the tackifier, conventionally known ones can be contained, and examples thereof include rosins, terpenes, petroleum resins, coumarone resins, and indene resins.

[0036] [Semi-aromatic polyamide resin film] The laminate of the present invention is one in which a semi-aromatic polyamide resin film is laminated on a transparent substrate via an adhesive layer. In the present invention, examples of the semi-aromatic polyamide constituting the semi-aromatic polyamide resin film include those containing an aromatic dicarboxylic acid component and an aliphatic diamine component, and those containing an aliphatic dicarboxylic acid component and an aromatic diamine component. Examples of the semi-aromatic polyamide containing an aromatic dicarboxylic acid component and an aliphatic diamine component include polyamide 9T composed of terephthalic acid and 1,9-nonanediamine, polyamide 10T composed of terephthalic acid and 1,10-decanediamine, and the like. Examples of the semi-aromatic polyamide containing an aliphatic dicarboxylic acid component and an aromatic diamine component include polyamide MXD6 composed of adipic acid and metaxylylenediamine, and the like. Among the above semi-aromatic polyamides, the semi-aromatic polyamide used in the present invention is preferably one containing an aromatic dicarboxylic acid component and an aliphatic diamine component because of the excellent balance between transparency and dimensional stability. Hereinafter, the semi-aromatic polyamide containing an aromatic dicarboxylic acid component and an aliphatic diamine component will be described in detail.

[0037] The aromatic dicarboxylic acid component preferably contains 60 mol% or more of terephthalic acid, more preferably 70 mol% or more, and still more preferably 85 mol% or more. When the content of terephthalic acid is less than 60 mol%, the resulting film has reduced heat resistance and low water absorption. Examples of the aromatic dicarboxylic acid component other than terephthalic acid include isophthalic acid, naphthalenedicarboxylic acid (1,2-isomer, 1,3-isomer, 1,4-isomer, 1,5-isomer, 1,6-isomer, 1,7-isomer, 1,8-isomer, 2,3-isomer, 2,6-isomer, 2,7-isomer).

[0038] The semi-aromatic polyamide may contain a dicarboxylic acid component other than the aromatic dicarboxylic acid component as long as the effects of the present invention are not impaired. Examples of other dicarboxylic acids include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, and octadecanedioic acid.

[0039] The aliphatic diamine component preferably contains an aliphatic diamine having 6 to 12 carbon atoms as a main component, more preferably contains an aliphatic diamine having 9 to 12 carbon atoms as a main component, and even more preferably contains an aliphatic diamine having 9 or 10 carbon atoms as a main component. The content of the aliphatic diamine having 6 to 12 carbon atoms in the aliphatic diamine component is preferably 60 mol% or more, more preferably 75 mol% or more, and even more preferably 90 mol% or more. When the content of the aliphatic diamine having 6 to 12 carbon atoms is 60 mol% or more, the resulting film can achieve both heat resistance and productivity. The aliphatic diamine having 6 to 12 carbon atoms may be used alone or in combination of two or more. When two or more are used in combination, the content is the total thereof.

[0040] Examples of the aliphatic diamine having 6 to 12 carbon atoms include linear aliphatic diamines such as 1,6 - hexanediamine, 1,7 - heptanediamine, 1,8 - octanediamine, 1,9 - nonanediamine, 1,10 - decanediamine, 1,11 - undecanediamine, 1,12 - dodecanediamine, and branched - chain aliphatic diamines such as 2 - methyl - 1,8 - octanediamine, 4 - methyl - 1,8 - octanediamine, 5 - methyl - 1,9 - nonanediamine, 2,2,4 - / 2,4,4 - trimethyl - 1,6 - hexanediamine, 2 - methyl - 1,5 - pentanediamine, 2 - methyl - 1,6 - hexanediamine, 2 - methyl - 1,7 - heptanediamine. Examples of the aliphatic diamine other than the aliphatic diamine having 6 to 12 carbon atoms include linear aliphatic diamines such as 1,4 - butanediamine and 1,5 - pentanediamine.

[0041] The semi-aromatic polyamide may contain a diamine component other than an aliphatic diamine component as long as the effects of the present invention are not impaired. Examples of other diamines include alicyclic diamines such as isophoronediamine, norbornanedimethylamine, and tricyclodecanedimethylamine, and aromatic diamines such as metaxylylenediamine, paraxylylenediamine, metaphenylenediamine, and paraphenylenediamine.

[0042] The semi-aromatic polyamide may be copolymerized with lactams such as ε-caprolactam, ζ-enanthlactam, η-capryllactam, and ω-laurolactam as long as the effects of the present invention are not impaired.

[0043] The type and copolymerization ratio of the monomers constituting the semi-aromatic polyamide are preferably selected so that the melting point (Tm) of the resulting semi-aromatic polyamide is in the range of 270 to 350°C. When the Tm of the semi-aromatic polyamide is within the above range, thermal decomposition during film processing can be efficiently suppressed. If the Tm is less than 270°C, the resulting film may have insufficient heat resistance. On the other hand, if the Tm exceeds 350°C, thermal decomposition may occur during film production.

[0044] The intrinsic viscosity of the semi-aromatic polyamide is preferably 0.8 to 2.0 dL / g, more preferably 0.9 to 1.8 dL / g. When the intrinsic viscosity of the semi-aromatic polyamide is 0.8 dL / g or more, a film with excellent mechanical strength can be produced, but if it exceeds 2.0 dL / g, it may be difficult to produce the film.

[0045] Commercially available products can be preferably used as the semi-aromatic polyamide. Examples of such commercially available products include Genesta (registered trademark) manufactured by Kuraray Co., Ltd., Zecon (registered trademark) manufactured by Unitika Ltd., Reni (registered trademark) manufactured by Mitsubishi Engineering-Plastics Corporation, Arlen (registered trademark) manufactured by Mitsui Chemicals, Inc., Ultramid (registered trademark) manufactured by BASF SE, and Nylon MXD6 manufactured by Mitsubishi Gas Chemical Company, Inc.

[0046] Semi-aromatic polyamides can be produced using methods known as methods for producing crystalline polyamides. For example, a solution polymerization method or an interfacial polymerization method (Method A) using an acid chloride and a diamine component as raw materials, or a method (Method B) of producing a low polymer using a dicarboxylic acid component and a diamine component as raw materials and increasing the molecular weight of the low polymer by melt polymerization or solid-phase polymerization, a method (Method C) of producing a crushed mixture of a salt and a low polymer using a dicarboxylic acid component and a diamine component as raw materials and subjecting this to solid-phase polymerization, a method (Method D) of producing a salt using a dicarboxylic acid component and a diamine component as raw materials and subjecting this to solid-phase polymerization, and the like can be mentioned. Among these, Method C and Method D are preferred, and Method D is more preferred. Method C and Method D can produce a crushed mixture of a salt and a low polymer or a salt at a low temperature compared to Method B, and also do not require a large amount of water when producing a crushed mixture of a salt and a low polymer or a salt. Therefore, the generation of a gel-like substance can be reduced, and fish eyes can be reduced.

[0047] In Method B, for example, a nylon salt prepared by mixing a diamine component, a dicarboxylic acid component, and a polymerization catalyst all at once can be heated and polymerized at a temperature of 200 to 250°C to obtain a low polymer. The intrinsic viscosity of the low polymer is preferably 0.1 to 0.6 dL / g. By setting the intrinsic viscosity of the low polymer within this range, in subsequent solid-phase polymerization or melt polymerization, the molar balance between the carboxyl group in the dicarboxylic acid component and the amino group in the diamine component does not collapse, and there is an advantage that the polymerization rate can be increased. If the intrinsic viscosity of the low polymer is less than 0.1 dL / g, the polymerization time becomes long, and the productivity may be poor. On the other hand, if it exceeds 0.6 dL / g, the resulting semi-aromatic polyamide may be colored. The solid-phase polymerization of the low polymer is preferably carried out under reduced pressure or under a flow of inert gas. Also, the temperature of the solid-phase polymerization is preferably 200 to 280 °C. By setting the temperature of the solid-phase polymerization within this range, coloring and gelation of the resulting semi-aromatic polyamide can be suppressed. If the temperature of the solid-phase polymerization is less than 200 °C, the polymerization time may become long, resulting in poor productivity. On the other hand, if it exceeds 280 °C, coloring and gelation may occur in the resulting semi-aromatic polyamide. The melt polymerization of the low polymer is preferably carried out at a temperature of 350 °C or lower. If the polymerization temperature exceeds 350 °C, decomposition and thermal degradation of the semi-aromatic polyamide may be promoted. Therefore, the film obtained from such a semi-aromatic polyamide may be inferior in strength and appearance. Note that the above melt polymerization includes melt polymerization using a melt extruder.

[0048] In the C method, for example, a suspension composed of a molten aliphatic diamine and a solid aromatic dicarboxylic acid is stirred and mixed to obtain a mixed solution. Then, in this mixed solution, at a temperature below the melting point of the finally produced semi-aromatic polyamide, a salt formation reaction by the reaction of the aromatic dicarboxylic acid and the aliphatic diamine and a low polymer formation reaction by the polymerization of the produced salt are carried out to obtain a mixture of the salt and the low polymer. In this case, crushing may be carried out while the reaction is in progress, or it may be carried out after once taking out the reaction product and then crushing. Then, the obtained reaction product is subjected to solid-phase polymerization at a temperature below the melting point of the finally produced semi-aromatic polyamide to increase the molecular weight to a predetermined molecular weight, and a semi-aromatic polyamide is obtained. The solid-phase polymerization is preferably carried out at a polymerization temperature of 180 to 270 °C and a reaction time of 0.5 to 10 hours in a stream of an inert gas such as nitrogen.

[0049] In the D method, for example, aromatic dicarboxylic acid powder is heated to a temperature equal to or higher than the melting point of the aliphatic diamine and lower than the melting point of the aromatic dicarboxylic acid in advance. To the aromatic dicarboxylic acid powder at this temperature, an aliphatic diamine is added to produce a salt without substantially containing water so as to keep the powder state of the aromatic dicarboxylic acid. Then, the obtained salt is subjected to solid-phase polymerization at a temperature lower than the melting point of the finally produced semi-aromatic polyamide to increase the molecular weight to a predetermined molecular weight, thereby obtaining a semi-aromatic polyamide. The solid-phase polymerization is preferably carried out at a polymerization temperature of 180 to 270°C and a reaction time of 0.5 to 10 hours in an inert gas stream such as nitrogen.

[0050] The raw material of the semi-aromatic polyamide resin film may be a mixture of virgin raw materials, or a mixture of off-specification films generated during the production of the semi-aromatic polyamide resin film and scraps generated as ear trimmings, or a mixture of the scrap mixture and virgin raw materials. These mixtures can be prepared by known methods such as the dry blending method using a known apparatus or the kneading method of melt-kneading and mixing using a single-screw or twin-screw extruder.

[0051] The semi-aromatic polyamide may contain a polymerization catalyst and a terminal blocking agent. Examples of the terminal blocking agent include acetic acid, lauric acid, benzoic acid, octylamine, cyclohexylamine, and aniline. Examples of the polymerization catalyst include phosphoric acid, phosphorous acid, hypophosphorous acid, or their salts.

[0052] The semi-aromatic polyamide resin film constituting the laminate of the present invention may contain fine particles for the purpose of improving slipperiness or the like. The semi-aromatic polyamide resin film can contain either inorganic fine particles or organic fine particles.

[0053] Examples of the inorganic particles include silica, alumina, titanium dioxide, calcium carbonate, kaolin, barium sulfate, etc. Examples of the organic fine particles include acrylic resin particles, melamine resin particles, silicone resin particles, crosslinked polystyrene particles, etc. Among them, silica and acrylic resin particles are preferred in terms of good dispersibility and handleability in the semi-aromatic polyamide resin film.

[0054] The average particle diameter of the fine particles is preferably 0.05 to 5.0 μm, and more preferably 0.1 to 4.0 μm. Also, the content of the fine particles is preferably 0 to 0.2% by mass, more preferably 0.01 to 0.2% by mass, and even more preferably 0.02 to 0.1% by mass. In addition, when the average particle diameter of the fine particles is 0.05 to 2.0 μm, it is used at a content of 0.2% by mass or less, and when the average particle diameter is 2.1 to 5.0 μm, it is used at a content of 0.1% by mass or less, so that the slipperiness of the semi-aromatic polyamide resin film can be improved efficiently. Also, two or more kinds of fine particles having different average particle diameters can be used in combination. As described above, the average particle diameter and content of the fine particles can be selected according to the friction characteristics, optical characteristics, and other required characteristics of the film. The fine particles can be added within a range that does not impair transparency, but it is preferably not added in order to obtain high transparency.

[0055] In addition to the above-mentioned fine particles, the semi-aromatic polyamide resin film may contain additives such as lubricants, pigments such as titanium, colorants such as dyes, color inhibitors, heat stabilizers, antioxidants such as hindered phenols, phosphoric acid esters and phosphorous acid esters, weather resistance improvers such as benzotriazole-based compounds, bromine-based and phosphorus-based flame retardants, plasticizers, release agents, reinforcing agents such as talc, modifiers, antistatic agents, ultraviolet absorbers, antifogging agents, and various polymer resins, as required. The surface of the semi-aromatic polyamide resin film may be subjected to corona treatment, plasma treatment, acid treatment, flame treatment, etc. in order to improve the adhesion to the adhesive layer.

[0056] As a method of incorporating the above additives into the semi-aromatic polyamide resin film, various methods can be used. As typical methods, the following methods can be mentioned. (A) Method of adding during the polymerization of semi-aromatic polyamide (B) Masterbatch method of directly adding to semi-aromatic polyamide and preparing melt-kneaded pellets (C) Method of directly adding to semi-aromatic polyamide during film formation and melt-kneading with an extruder (D) Method of directly adding to an extruder during film formation and melt-kneading

[0057] The semi-aromatic polyamide resin film may be a single-layer film composed of one type of layer or a multi-layer structure formed by laminating two or more types of layers. In the case of a multi-layer structure, for example, in a two-layer film, a lubricant can be contained in any one of the two layers, and in a three-layer film, lubricants can be contained in the layers located on both surfaces among the three layers. The type and content of the lubricant to be contained can be designed independently. By adopting such a multi-layer structure, the surface roughness of each surface of the semi-aromatic polyamide resin film can be independently controlled.

[0058] <Easy adhesion layer> In the present invention, it is preferable from the viewpoints of the adhesiveness and impact resistance of the laminate that an easy adhesion layer is laminated between the adhesive layer and the semi-aromatic polyamide resin film, and a semi-aromatic polyamide resin film having an easy adhesion treatment applied to its surface can be used. The components constituting the easy adhesion layer are not particularly limited, and various resins can be used. Examples of the resin include polyamide-based resins, polyester-based resins, polyurethane-based resins, acrylic-based resins, epoxy-based resins, and the like.

[0059] As the polyamide-based resin constituting the easy adhesion layer, the polyamide-based resin constituting the above-mentioned adhesive layer can be preferably used. The polyester resin is not particularly limited, and examples include those composed of a polybasic acid component and a polyhydric alcohol component and produced by a known polymerization method. It is possible to use only one type or a combination of two or more types. Examples of commercially available polyester resins include Elite KA-5034, KZA-0134, KZA-3556 manufactured by Unitika Ltd., Plascoat Z-730, RZ-142 manufactured by Gohsei Chemical Industry Co., Ltd., and the like.

[0060] The polyurethane resin is not particularly limited, and various polyurethane resins such as polyester-based urethane resins, polyether-based urethane resins, and polycarbonate-based urethane resins can be mentioned. Further, from the viewpoint of improving the adhesiveness with a semi-aromatic polyamide resin film or an adhesive layer, a compound having a sulfo group or a compound having a carboxyl group may be copolymerized. The polyurethane resin is not particularly limited, but from the viewpoint of the problem of the solvent remaining in the easy-adhesion layer and the low environmental pollution, it is preferably an aqueous urethane resin. A commercially available polyurethane resin may be used as the polyurethane resin. Examples of the aqueous dispersion of the polyurethane resin include Hydran series manufactured by DIC Corporation, Superflex series manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Takelac series manufactured by Mitsui Chemicals, Inc., Adeka Bon Titizer series manufactured by Adeka Corporation, and Eucort manufactured by Sanyo Chemical Industries, Ltd.

[0061] The acrylic resin is not particularly limited, but is mainly composed of ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc., and is copolymerized with vinyl compounds such as styrene, methyl methacrylate, acrylonitrile, etc. and functional group monomers such as acrylic acid, methacrylic acid, itaconic acid, acrylamide, methylol acrylamide, hydroxyethyl acrylate, hydroxyethyl methacrylate, etc. For the formation of the easy-adhesion layer, it is preferable to use these acrylic resins as an aqueous dispersion dispersed in an aqueous medium.

[0062] In the easy-adhering layer, various agents such as crosslinking agents, leveling agents, defoaming agents, anti-crawling agents, pigment dispersants, ultraviolet absorbers, etc., and pigments or dyes such as titanium oxide, zinc acid value, carbon black, etc. can be added as necessary within the range that does not impair physical properties such as adhesiveness, impact resistance, and transparency.

[0063] Further, the easy-adhering layer may contain fine particles. As the fine particles, either inorganic fine particles or organic fine particles can be used. Examples of the inorganic fine particles include fine particles of inorganic compounds such as silica, alumina, titanium dioxide, calcium carbonate, kaolin, barium sulfate, zinc oxide, niobium oxide, neodymium oxide, lanthanum oxide, zirconium oxide, cerium oxide, and magnesium oxide. Examples of the organic fine particles include acrylic particles, melamine particles, silicone particles, polyimide particles, crosslinked polyester particles, crosslinked polystyrene particles, crosslinked polyethylene particles, crosslinked polypropylene particles, silicone particles, nylon particles, polyacrylonitrile particles, benzoguanamine-formaldehyde resin particles, styrene divinylbenzene copolymer particles, acrylic divinylbenzene copolymer, and the like. Among them, silica and acrylic resin particles are preferable in terms of good handling. These inorganic and organic fine particles can be used alone or in a blend of a plurality, and may be surface-treated to enhance dispersibility and adhesion.

[0064] The average particle diameter of the fine particles is preferably 0.010 to 4.0 μm, more preferably 0.030 to 3.0 μm, and even more preferably 0.050 to 2.0 μm. The average particle diameter of the fine particles can be arbitrarily selected according to friction characteristics, optical characteristics, anti-blocking properties, and other required properties of the film.

[0065] <Manufacture of the laminate> Next, the manufacturing method of the laminate will be described. The laminate of the present invention can be produced by forming an adhesive layer on one surface of either a transparent substrate or a semi-aromatic polyamide resin film, then overlaying the other film or substrate, and applying heat and pressure as necessary for bonding.

[0066] As a method for forming the adhesive layer, for example, a coating agent in which the resin constituting the adhesive layer is dissolved or dispersed is applied to the surface of the transparent substrate or the semi-aromatic polyamide resin film and then dried, a method by coating, or a method in which the resin constituting the adhesive layer is heat-melted on the surface of the transparent substrate or the semi-aromatic polyamide resin film and then extrusion-coated, or a method in which an adhesive layer previously formed on a process film such as a release film is bonded to the surface of the transparent substrate or the semi-aromatic polyamide resin film and transferred. Among these, from the viewpoint of easily forming a uniform and thin adhesive layer, the method by coating is preferable.

[0067] As a method for applying the coating agent, a known method can be adopted. For example, gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating method, etc. can be mentioned. By the above method, after applying the coating agent on the transparent substrate or the semi-aromatic polyamide resin film, the adhesive layer can be formed by subjecting the coating film to dry heat treatment.

[0068] The conditions for laminating the transparent substrate and the semi-aromatic polyamide resin film through the formed adhesive layer are not particularly limited, but methods such as pressurizing at room temperature after overlaying or pressurizing while heating after overlaying can be adopted. The heating temperature may be selected according to the resin contained in the adhesive layer. For example, in the case of an adhesive layer containing a polyamide-based resin, it is preferably 100 to 200°C, more preferably 120 to 190°C, and even more preferably 140 to 180°C. At the time of bonding, it is preferable to perform bonding by pressurizing to about 0.1 MPa at the above heating temperature.

[0069] <Properties of the laminate> For the laminate of the present invention, it is necessary that the adhesive strength between the transparent substrate and the semi-aromatic polyamide resin film laminated via the adhesive layer is 4 N / 10 mm or more, preferably 5 N / 10 mm or more, and more preferably 6 N / 10 mm or more. When the laminate of the present invention satisfies the above range of the adhesive strength, when the impact resistance test described later is performed, it becomes possible to prevent cracking of the transparent substrate, and it is also possible to prevent whitening caused by peeling between the transparent substrate and the semi-aromatic polyamide resin film, and excellent impact resistance can be obtained. When the adhesive strength of the laminate is less than 4 N / 10 mm, the transparent substrate is likely to crack in the impact resistance test, or although the transparent substrate does not crack, peeling occurs between the transparent substrate and the semi-aromatic polyamide resin film, resulting in a decrease in transparency, making it difficult to use as a material for displays and the like.

[0070] The laminate of the present invention preferably has impact resistance with a 50% fracture height of 400 mm or more in the steel ball drop test. More specifically, as described later, in a test in which a steel ball with a weight of 225.6 g and a diameter of φ38.1 mm is dropped on the transparent substrate while changing the height, the drop height of the steel ball at which 50% of the transparent substrate is fractured is preferably 400 mm or more.

[0071] The transparency of the laminate of the present invention is not particularly limited, but it is preferably excellent in transparency. As specific performance, the haze is preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.0 or less. Further, for the laminate of the present invention, the total light transmittance is preferably 85% or more, more preferably 88% or more, and even more preferably 90% or more.

[0072] <Use of the laminate> Since the laminate of the present invention is excellent in impact resistance and transparency, it can be applied to various uses including display uses such as liquid crystal displays and organic LEDs, for example, solar cell substrates, sensors, and the like.

Examples

[0073] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. The characteristics of the laminate were measured and evaluated by the following methods.

[0074] <Adhesion strength> The transparent substrate surface of the laminate and a SUS plate (reinforcing support) were bonded together with a double-sided tape to obtain a test piece. The test piece was cut into a width of 10 mm, the semi-aromatic polyamide resin film of the test piece was pulled, and the semi-aromatic polyamide film and the transparent substrate were peeled off to measure the adhesion strength. The adhesion strength was measured using a tensile testing machine (manufactured by Intesco Co., Ltd., Precision Universal Material Testing Machine Model 2020) under the conditions of 180-degree peel and a tensile speed of 200 mm / min at room temperature. Five test pieces were measured, and the average value was taken as the adhesion strength.

[0075] <Impact resistance> A sample of the laminate (18 mm in length × 18 mm in width) was placed with the transparent substrate surface facing up, and a stainless steel plate (thickness 1.5 mm, SUS304, manufactured by Nippon Test Panel Co., Ltd.) was placed under the semi-aromatic polyamide resin film. A steel ball with a weight of 225.6 g and a diameter of 38.1 mm was dropped onto the transparent substrate at different drop heights. For 10 samples, the height (reference drop height H) at which the sample may or may not crack was determined. Referring to the DuPont impact strength measurement method of JIS K 5400, the steel ball was dropped from the reference drop height H to determine the presence or absence of damage to the transparent substrate. When damage was observed on the transparent substrate, the drop height of the steel ball was lowered by one level and the retest was carried out. When no damage was observed on the transparent substrate, the drop height of the steel ball was increased by one level and the retest was carried out. The drop test was repeated 20 times in total, and the 50% fracture height (H 50 ) was obtained using the following formula. The change interval d of one level was carried out at 50 mm. H 50 = H + d(Σ(i·ni) / N - 1 / 2) H = reference drop height (mm) d = height change interval (mm) i = level number (···3, 2, 1, 0, -1, -2, -3···) ni = number of occurrences of failure at each level N = total number of occurrences of failure (= Σni)

[0076] <Total light transmittance (T.t) and haze (Hz)> The laminate obtained in the example was measured in accordance with JIS K 7136 using a turbidity meter (manufactured by Nippon Electric Shokai Co., Ltd., NDH2000).

[0077] The following materials were used for the production of the laminate. <Transparent substrate> The following were used as the transparent substrate. 〔Glass plate G-1〕 Manufactured by Matsunami Glass Industry Co., Ltd., cover glass No. 1, size 50 mm × 70 mm, thickness approximately 150 μm (130 - 170 μm) 〔Toughened glass plate G-2〕 Manufactured by Nippon Electric Glass Co., Ltd., Dinorex T2X-1, size 50 mm × 50 mm, thickness 55 μm 〔Transparent polyimide film CPI〕 Manufactured by Mitsubishi Gas Chemical Company, Inc., Neoprim L-3450, thickness 30 μm

[0078] <Materials used for forming the adhesive layer> 〔Acrylic adhesive A-1〕 Acrylic adhesive (manufactured by Soken Chemical & Engineering Co., Ltd., SK Dyn 1502C, solid content concentration 40 mass%)

[0079] 〔Polyether ester amide solution P-1〕 Polyether ester amide (manufactured by T&K TOKA Co., Ltd., TPAE-12) was dissolved in a mixed solvent of toluene / isopropyl alcohol = 1 / 1 so that the solid content concentration became 15 mass% to obtain a polyether ester amide solution P-1.

[0080] 〔Dimer Acid-based Polyamide Resin Aqueous Dispersion P-2〕 As the dimer acid-based polyamide resin, a resin containing 100 mol% of dimer acid as the dicarboxylic acid component and 100 mol% of ethylenediamine as the diamine component, having an acid value of 10.0 mgKOH / g, an amine value of 0.1 mgKOH / g, and a softening point of 158 °C was used. Into a sealable pressure-resistant 1-liter glass container equipped with a stirrer and a heater, 75.0 g of the dimer acid-based polyamide resin, 37.5 g of isopropanol (IPA), 37.5 g of tetrahydrofuran (THF), 7.2 g of N,N-dimethylethanolamine, and 217.8 g of distilled water were charged. While stirring at a rotation speed of 300 rpm, the system was heated and heated with stirring at 120 °C for 60 minutes. Then, while stirring, it was cooled to near room temperature (about 30 °C), and after adding 100 g of distilled water, it was filtered while applying slight pressure with a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave). The obtained aqueous dispersion was placed in a 1-L eggplant flask, and while heating it in a water bath heated to 80 °C, it was depressurized using an evaporator to distill off about 100 g of a mixed medium of IPA, THF, and water, and a milky white uniform dimer acid-based polyamide resin aqueous dispersion P-2 was obtained. The solid content concentration of P-2 was 20% by mass, the number average particle diameter of the resin in the dispersion was 0.040 μm, the pH was 10.4, and the viscosity was 36 mPa·s.

[0081] 〔Urethane-based Adhesive P-3〕 An adhesive prepared by mixing Takelac A-310 and Takenate A-3 (manufactured by Mitsui Chemicals, Inc.) at a mass ratio of Takelac A-310 / Takenate A-3 / ethyl acetate = 10 / 1 / 13 was used.

[0082] 〔Polyolefin Resin Aqueous Dispersion P-4〕 As the polyolefin resin, Bondine LX4110 manufactured by Arkema was used. Into a sealable pressure-resistant 1-liter glass container equipped with a stirrer and a heater, 60.0 g of a polyolefin resin, 28.0 g of IPA, 1.5 g of triethylamine, and 210.5 g of distilled water were charged. When stirred with the rotation speed of the stirring blade set at 300 rpm, no precipitation of resin granules was observed at the bottom of the container, and it was confirmed that they were in a suspended state. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the temperature inside the system was maintained at 140 °C and stirring was continued for another 20 minutes. Thereafter, it was placed in a water bath and cooled to room temperature (about 25 °C) while stirring at a rotation speed of 300 rpm. Then, it was pressure-filtered (air pressure 0.2 MPa) through a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky white uniform polyolefin resin aqueous dispersion P-4. The solid content concentration of P-4 was 20% by mass and the viscosity was 70 mPa·s.

[0083] <Semi-aromatic polyamide resin film> 〔Semi-aromatic polyamide resin T-1〕 1343 g of 1,9-nonanediamine (NMDA), 237 g of 2-methyl-1,8-octanediamine (MODA), 1627 g of terephthalic acid (TPA) (average particle size: 80 μm) (NMDA:MODA:TPA = 85:15:99, molar ratio), 48.2 g of benzoic acid (BA) (4.0 mol% based on the total number of moles of the dicarboxylic acid component and the diamine component), 3.2 g of phosphorous acid (0.1% by mass based on the total amount of the dicarboxylic acid component and the diamine component), and 1100 g of water were placed in a reactor and purged with nitrogen. Further, after stirring at 80 °C for 0.5 hour at 28 rotations per minute, the temperature was raised to 230 °C. Thereafter, it was heated at 230 °C for 3 hours. Then, it was cooled and the reaction product was taken out. After pulverizing the reaction product, it was heated in a dryer at 220 °C for 5 hours under a nitrogen stream for solid-phase polymerization to obtain a polymer. Then, it was melt-kneaded under the condition of a cylinder temperature of 320 °C and extruded into strands. Thereafter, it was cooled and cut to prepare pellet-shaped semi-aromatic polyamide resin T-1.

[0084] 〔Semi-aromatic polyamide resin film F-1〕 100 parts by mass of a semi-aromatic polyamide resin T-1 and 0.2 parts by mass of 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane (manufactured by Sumitomo Chemical Co., Ltd., Sumilizer GA-80, thermal decomposition temperature 392 °C) were heated to a cylinder temperature of 320 °C and charged into a single-screw extruder with a screw diameter of 50 mm and melted to obtain a molten polymer. The molten polymer was filtered using a metal fiber sintered filter (manufactured by Nippon Seisen Co., Ltd., NF-10, absolute particle size: 30 μm). Then, it was extruded in a film shape from a T-die set at 320 °C to obtain a film-shaped melt. The melt was adhered to a cooling roll set at 50 °C by electrostatic printing method and cooled to obtain an unstretched film (thickness: 250 μm) that was substantially unoriented. Next, while gripping both ends of this unstretched film with clips, it was guided into a tenter-type simultaneous biaxial stretching machine (entrance width: 193 mm, exit width: 605 mm) and subjected to simultaneous biaxial stretching. The stretching conditions were: the temperature of the preheating section was 120 °C, the temperature of the stretching section was 130 °C, the stretching strain rate in the MD direction was 2400% / min, the stretching strain rate in the TD direction was 2760% / min, the stretching ratio in the MD direction was 3.0 times, and the stretching ratio in the TD direction was 3.3 times. Then, in the same tenter, heat setting was performed at 270 °C, and a relaxation treatment of 5% in the width direction of the film was performed to obtain a biaxially stretched film with a thickness of 25 μm. The obtained biaxially stretched semi-aromatic polyamide resin film was used as the base film F-1.

[0085] 〔Semi-aromatic polyamide resin film F-2〕 As the unstretched film, an operation similar to the manufacturing method of F-1 was performed except that a film with a thickness of 500 μm was used, and a biaxially stretched film with a thickness of 50 μm was obtained. The obtained biaxially stretched semi-aromatic polyamide resin film was used as the base film F-2.

[0086] 〔Semi-aromatic polyamide resin film F-3〕 A urethane resin aqueous dispersion (composition of each unit constituting the resin: terephthalic acid / isophthalic acid / naphthalenedicarboxylic acid / sebacic acid / bisphenol A ethylene oxide / ethylene glycol / neopentyl glycol / tolylene diisocyanate (5 / 10 / 10 / 10 / 30 / 5 / 15 / 15 (mol%)), solid content concentration: 20% by mass) and acrylic particles (manufactured by JXTG Energy Corporation, Eposter NMB-0220C) were mixed so that the content of the acrylic particles was 0.2% by mass with respect to the whole components constituting the easy-adhesion layer, and a liquid material for forming the easy-adhesion layer was prepared. The semi-aromatic polyamide resin (T-1) was put into a single-screw extruder with a cylinder temperature of 320 °C and a screw diameter of 50 mm and melted, filtered using a metal fiber sintered filter (manufactured by Nippon Seisen Co., Ltd., NF-10, absolute particle size: 30 μm), and then extruded in film form from a T-die heated to 320 °C to obtain a film-like melt. The melt was adhered to a cooling roll at 50 °C by electrostatic printing method and cooled to obtain an unstretched film (thickness: 250 μm) with substantially no orientation. Subsequently, the above liquid material for forming the easy-adhesion layer was applied to the unstretched film using a gravure coater so that the thickness of the easy-adhesion layer after drying and stretching became 0.2 μm, and then led to a tenter-type simultaneous biaxial stretching machine. While gripping both ends of the unstretched film with clips, simultaneous biaxial stretching was performed to obtain an easy-adhesion film. The stretching was carried out under the conditions that the temperature of the preheating section was 120 °C, the temperature of the stretching section was 130 °C, the longitudinal stretching strain rate was 2400% / min, the transverse stretching strain rate was 2760% / min, the longitudinal stretching ratio was 3.0 times, and the transverse stretching ratio was 3.3 times. Then, heat setting was performed at 270 °C in the same tenter, and a relaxation treatment of 5% in the width direction of the film was applied to obtain a biaxially stretched easy-adhesion film with a thickness of 25 μm. The obtained biaxially stretched semi-aromatic polyamide resin film having the easy-adhesion layer was used as the base film F-3.

[0087] 〔Semi-aromatic polyamide resin film F-4〕 As the unstretched film, an operation similar to the manufacturing method of F-3 was performed except that a film with a thickness of 500 μm was used, and a biaxially stretched film with a thickness of 50 μm was obtained. The obtained biaxially stretched semi-aromatic polyamide resin film having an easy-adhesion layer was used as the base film F-4.

[0088] 〔Semi-aromatic polyamide resin film F-5〕 The semi-aromatic polyamide resin T-1 was changed to an aromatic nylon resin (manufactured by Unitika Ltd., Zecon XN500), and a film was obtained by the same operation as the semi-aromatic polyamide resin film F-1. The obtained semi-aromatic nylon film was used as the base film F-5.

[0089] 〔Semi-aromatic polyamide resin film F-6〕 The semi-aromatic polyamide resin T-1 was changed to an aromatic nylon resin (manufactured by Unitika Ltd., Zecon XN500), and a film was obtained by the same operation as the semi-aromatic polyamide resin film F-2. The obtained semi-aromatic nylon film was used as the base film F-6.

[0090] Example 1 An acrylic adhesive A-1 was applied to the semi-aromatic polyamide resin film F-1 so that the thickness after drying would be 50 μm, and it was dried under the conditions of 100 °C for 1 minute to form an adhesive layer. Then, the adhesive layer on the semi-aromatic polyamide resin film was laminated onto the glass plate G-1 at room temperature while pressing a rubber roll against it to obtain a laminate.

[0091] Example 2 In Example 1, the same operation was performed except that the thickness of the adhesive layer was adjusted to 15 μm to obtain a laminate.

[0092] Example 3 In Example 2, the same operation was performed except that a tempered glass plate G-2 was used as the transparent base material to obtain a laminate.

[0093] Example 4 In Example 2, the same operations were performed except that a transparent polyimide film CPI was used as the transparent substrate to obtain a laminate.

[0094] Example 5 A polyether ester amide solution P-1 was applied to a semi-aromatic polyamide resin film F-1 so that the thickness after drying would be 6 μm, and it was dried under the conditions of 100 °C for 1 minute to form an adhesive layer. Then, the adhesive layer on the semi-aromatic polyamide resin film was laminated onto a glass plate G-1 at room temperature while pressing a rubber roll against it, and after that, it was pressed under the conditions of 180 °C and 0.5 MPa for 15 minutes and then allowed to cool at room temperature to obtain a laminate.

[0095] Example 6 In Example 5, when forming the adhesive layer, the same operations were performed except that a mixture obtained by blending a polyether ester amide solution P-1 and an epoxy compound (Denacol EX-512 manufactured by Nagase ChemteX Corporation, solid content concentration 100% by mass) so that the respective solid contents would be in a ratio of 100 parts by mass / 20 parts by mass and stirring and mixing them at room temperature for 5 minutes was used to obtain a laminate.

[0096] Example 7 In Example 6, the same operations were performed except that the thickness of the adhesive layer was set to 10 μm to obtain a laminate.

[0097] Example 8 In Example 6, the same operations were performed except that the thickness of the adhesive layer was set to 15 μm to obtain a laminate.

[0098] Example 9 In Example 7, the same operations were performed except that a strengthened glass plate G-2 was used as the transparent substrate to obtain a laminate.

[0099] Example 10 In Example 7, the same operations were performed except that a transparent polyimide film CPI was used as the transparent substrate to obtain a laminate.

[0100] Example 11 In Example 5, in forming the adhesive layer, the same operations were performed except that an aqueous dispersion of dimer acid-based polyamide resin P-2 was used and applied so that the thickness of the adhesive layer became 10 μm, to obtain a laminate.

[0101] Example 12 In Example 11, in forming the adhesiveness, an aqueous dispersion of dimer acid-based polyamide resin P-2 and an aqueous solution of an oxazoline group-containing polymer (manufactured by Nippon Shokubai Co., Ltd., Epocros WS-700, solid content concentration 25% by mass) were blended so that the solid content mass ratio of each became 100 / 10, and the same operations were performed except that a liquid material obtained by mixing and stirring at room temperature for 5 minutes was used, to obtain a laminate.

[0102] Example 13 In Example 12, in forming the adhesiveness, an aqueous dispersion of dimer acid-based polyamide resin P-2, an aqueous solution of an oxazoline group-containing polymer (manufactured by Nippon Shokubai Co., Ltd., Epocros WS-700, solid content concentration 25% by mass), and colloidal silica fine particles (manufactured by Fuso Chemical Co., Ltd., Quartron PL-7, average particle diameter 0.07 μm) were blended so that the solid content mass ratio of each became 100 / 10 / 5, and the same operations were performed except that a liquid material obtained by mixing and stirring at room temperature for 5 minutes was used, to obtain a laminate.

[0103] Example 14 In Example 13, the same operations were performed except that the solid content mass ratio in the liquid material was blended so as to be 100 / 10 / 10, to obtain a laminate.

[0104] Example 15 In Example 5, in forming the adhesive layer, a urethane-based adhesive P-3 was used and applied onto a semi-aromatic polyamide film so that the coating thickness after drying became 10 μm, and dried at 100°C for 30 seconds to form an adhesive layer. Then, it was bonded to a glass plate and left in an environment at 40°C for 24 hours for the adhesive to cure, to obtain a laminate.

[0105] Example 16 In Example 5, a laminate was obtained by performing the same operations except that when forming the adhesive layer, the polyolefin resin aqueous dispersion P-4 was used and the thickness was made 10 μm.

[0106] Example 17 In Example 1, a laminate was obtained by performing the same operations except that the semi-aromatic polyamide resin film F-2 was used.

[0107] Example 18 In Example 2, a laminate was obtained by performing the same operations except that the semi-aromatic polyamide resin film F-2 was used.

[0108] Example 19 In Example 7, a laminate was obtained by performing the same operations except that the semi-aromatic polyamide resin film F-2 was used.

[0109] Example 20 In Example 2, a laminate was obtained by performing the same operations except that the semi-aromatic polyamide resin film F-3 was used.

[0110] Example 21 In Example 20, a laminate was obtained by performing the same operations except that the tempered glass plate G-2 was used as the transparent substrate.

[0111] Example 22 In Example 20, a laminate was obtained by performing the same operations except that the transparent polyimide film CPI was used as the transparent substrate.

[0112] Example 23 In Example 7, a laminate was obtained by performing the same operations except that the semi-aromatic polyamide resin film F-3 was used.

[0113] Example 24 In Example 7, a laminate was obtained by performing the same operations except that the semi-aromatic polyamide resin film F-4 was used.

[0114] Example 25 In Example 20, the same operations were carried out except that the semi-aromatic polyamide resin film F-5 was used to obtain a laminate.

[0115] Example 26 In Example 7, the same operations were carried out except that the semi-aromatic polyamide resin film F-6 was used to obtain a laminate.

[0116] Comparative Example 1 In Example 1, the same operations were carried out except that the thickness of the adhesive layer was set to 5 μm to obtain a laminate.

[0117] Comparative Example 2 In Comparative Example 1, the same operations were carried out except that the reinforced glass plate G-2 was used as the transparent substrate to obtain a laminate.

[0118] Comparative Example 3 In Comparative Example 1, the same operations were carried out except that the transparent polyimide film CPI was used as the transparent substrate to obtain a laminate.

[0119] Comparative Example 4 In Example 6, the same operations were carried out except that the thickness of the adhesive layer was set to 0.5 μm to obtain a laminate.

[0120] Comparative Example 5 In Example 1, the same operations were carried out except that the polyamide 6 film (manufactured by Unitika Ltd., Emblem ON-25, thickness 25 μm) was used instead of the semi-aromatic polyamide resin film to obtain a laminate.

[0121] Comparative Example 6 In Example 1, the same operations were carried out except that the polyester film (manufactured by Unitika Ltd., Embret S-50, thickness 50 μm) was used instead of the semi-aromatic polyamide resin film to obtain a laminate.

[0122] Comparative Example 7 In Example 1, the same operations were carried out except that the transparent polyimide film CPI was used instead of the semi-aromatic polyamide resin film to obtain a laminate.

[0123] Table 1 shows the manufacturing conditions and evaluated characteristics of the laminate of the examples and comparative examples.

[0124]

Table 1

[0125] The laminate of the example was excellent in impact resistance and transparency because the adhesive strength between the transparent substrate and the semi-aromatic polyamide resin film was 4 N / 10 mm or more. On the other hand, the laminates of Comparative Examples 1 to 4 had an adhesive strength of less than 4 N / 10 mm, and the laminates of Comparative Examples 5 to 7 used resin films other than the semi-aromatic polyamide resin film, so sufficient impact resistance could not be obtained in any of them.

Claims

1. A laminate in which a transparent substrate, an adhesive layer, and a semi-aromatic polyamide resin film are laminated in this order, the transparent substrate is glass, and the adhesive strength between the transparent substrate and the semi-aromatic polyamide resin film is 4 N / 10 mm or more.

2. The laminate according to claim 1, wherein in a test of dropping a steel ball with a weight of 225.6 g and a diameter of 38.1 mm onto the transparent substrate, the 50% fracture height is 400 mm or more.

3. The laminate according to claim 1 or 2, wherein the adhesive layer contains an acrylic adhesive.

4. The laminate according to claim 3, wherein the thickness of the adhesive layer is 10 to 50 μm.

5. The laminate according to claim 1 or 2, wherein the adhesive layer contains a polyamide-based resin.

6. The laminate according to claim 5, wherein the adhesive layer contains a crosslinking agent.

7. The laminate according to claim 5 or 6, wherein the thickness of the adhesive layer is 3 to 20 μm.

8. The laminate according to any one of claims 1 to 7, wherein an easy-adhesion layer is laminated between the adhesive layer and the semi-aromatic polyamide resin film.

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