Polycarbonate laminate

Abstract

In a polycarbonate laminate (10), a base material layer (1) containing a polycarbonate resin and a hard coat layer (2) constituting an outer surface are laminated. The thickness of the hard coat layer is 20-80 μm. The glossiness, which is the reflectance of light at an incidence angle of 60° and is measured in conformance with JIS Z 8741 on the hard-coat-layer-side surface after the polycarbonate laminate is processed at 80°C and 50% RH for 72 hours, is 97 or greater.

Description

Polycarbonate Laminate

[0001] The present invention relates to polycarbonate laminates, and more particularly to polycarbonate laminates and display screens or windows using the same.

[0002] Polycarbonate resin is known to have high transparency, abrasion resistance, heat resistance, etc. Therefore, molded articles obtained by heat bending a polycarbonate resin sheet are suitably used, for example, as various lenses for sunglasses and ski goggles, motorcycle windshields, and vehicle window materials.

[0003] For example, Patent Document 1 (WO 2019 / 049704) describes that the hardness of a resin sheet can be further increased by providing a high-hardness resin layer between a substrate layer containing a polycarbonate resin and a hard coat layer, and also discloses that the pencil hardness of the high-hardness resin is HB or higher.

[0004] International Publication No. 2019 / 049704

[0005] In recent years, polycarbonate has been attracting attention as a substitute for tempered glass. Therefore, when polycarbonate is used as a substitute for tempered glass, it is required to be able to continue to be used without cracking. However, conventional polycarbonate sheets such as those disclosed in Patent Document 1 have room for improvement in terms of hardness, and cracks may occur depending on the use conditions, etc.

[0006] The present inventors have conducted research into improving the hardness and crack resistance of polycarbonate laminates and devised a new index for the glossiness of a polycarbonate laminate having a hard coating layer on its surface. They have also found that it is effective to produce a polycarbonate laminate that satisfies this index, and have thus completed the present invention.

[0007] According to the present invention, the following polycarbonate laminate and related technology are provided.

[0008] [1] A polycarbonate laminate comprising a substrate layer containing a polycarbonate resin and a hard coat layer constituting an outer surface, wherein the hard coat layer has a thickness of 20 μm or more and 80 μm or less, and the polycarbonate laminate is treated under conditions of 80°C, 50% RH, and 72 hours, and the gloss, which is the reflectance of light at an incident angle of 60°, measured in accordance with JIS Z 8741, of the surface of the hard coat layer side is 97 or more. [2] The polycarbonate laminate according to [1], wherein the ratio of the thickness of the hard coat layer to the total thickness of the polycarbonate laminate is 0.1% or more and 2.0% or less. [3] The polycarbonate laminate according to [1] or [2], wherein the hard coat layer contains a cyclic ether compound. [4] The polycarbonate laminate according to [3], wherein the cyclic ether compound contains an epoxy ring and / or an oxetane ring. [5] The polycarbonate laminate according to any one of [1] to [4], wherein the hard coat layer is laminated so as to be in direct contact with the base layer. [6] The polycarbonate laminate according to any one of [1] to [5], wherein the thickness of the polycarbonate laminate is 3 mm or more and 20 mm or less. [7] The polycarbonate laminate according to any one of [1] to [6], wherein the pencil hardness of the surface facing the base layer is 2B or more and B or less. [8] The polycarbonate laminate according to any one of [1] to [7], wherein the polycarbonate laminate is used for a display screen and / or a window. [9] A display screen using the polycarbonate laminate according to any one of [1] to [8].

[10] A window using the polycarbonate laminate according to any one of [1] to [8].

[0009] According to the present invention, a polycarbonate laminate is provided that can improve surface hardness and crack resistance.

[0010] 1 is a cross-sectional view schematically illustrating a polycarbonate laminate 10 according to an embodiment of the present invention.

[0011] In this specification, the notation "a to b" in the description of a numerical range means from a to b, unless otherwise specified. For example, "1 to 5 mass%" means "1 mass% to 5 mass%." Furthermore, the lower limit and upper limit of a numerical range can be arbitrarily combined with the lower limit and upper limit of another numerical range.

[0012] Unless otherwise specified, each of the components and materials exemplified in this specification may be used alone or in combination of two or more.

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The drawings are for illustrative purposes only, and the shapes and dimensional ratios of the components in the drawings do not necessarily correspond to actual products.

[0014] <Polycarbonate Laminate> Fig. 1 is a cross-sectional view that schematically shows a polycarbonate laminate 10 according to this embodiment. The polycarbonate laminate 10 is in the form of a plate, a sheet, or a film.

[0015] The polycarbonate laminate 10 comprises a substrate layer 1 containing a polycarbonate resin and a hard coat layer 2 constituting the outer surface thereof. The polycarbonate laminate 10 is configured such that the thickness of the hard coat layer 2 is 20 μm or more and 80 μm or less, and the gloss, which is the reflectance of light at an incident angle of 60°, measured in accordance with JIS Z 8741 on the surface of the polycarbonate laminate 10 on the side of the hard coat layer 2 after treating the polycarbonate laminate 10 under conditions of 80°C, 50% RH, and 72 hours, is 97 or more.

[0016] This improves hardness and crack resistance. Although the details of this mechanism are not clear, it is thought to be as follows: Under conditions of 80°C, 50% RH, and 72 hours, the polycarbonate laminate 10 is subjected to a large thermal load, which causes distortion and other problems in the polycarbonate laminate 10, making it prone to cracks on the surface. Therefore, by using the glossiness of the surface on the hard coat layer 2 side of the polycarbonate laminate 10 treated under these conditions as an indicator, it is possible to highly control the surface condition of the polycarbonate laminate 10, and as a result, it is thought that cracks can be suppressed.

[0017] Furthermore, the polycarbonate laminate 10 satisfying the above-mentioned gloss level can be realized by appropriately combining the thickness balance of the hard coat layer 2, the selection of the material constituting the hard coat layer 2, the layer structure of the polycarbonate laminate 10, and the like.

[0018] In this embodiment, the substrate layer 1 and the hard coat layer 2 are laminated so as to be in direct contact with each other. This improves the surface hardness and crack resistance, while resolving the problems of formability and adhesion that arise in the prior art when co-extrusion molding the substrate layer and an intermediate layer such as a high-hardness resin layer. This improves productivity.

[0019] The total thickness of the polycarbonate laminate 10 is preferably 3 mm or more, more preferably 5 mm or more, and even more preferably 8 mm or more. This allows for improved strength while maintaining good moldability. On the other hand, the thickness of the polycarbonate laminate 10 is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 12 mm or less. This allows for improved moldability while maintaining good strength.

[0020] The total light transmittance of the polycarbonate laminate 10 can be appropriately set depending on the application, but from the viewpoint of letting in light while suppressing excessive glare from direct sunlight, it is preferably 70% or more, more preferably 80% or more, and on the other hand, it is preferably 92% or less, more preferably 90% or less. The total light transmittance can be measured in accordance with JIS K7361-1.

[0021] Each layer will be described in detail below.

[0022] [Substrate Layer 1] The substrate layer 1 is a layer that forms the base of the polycarbonate laminate 10. The substrate layer 1 contributes to maintaining good transparency and mechanical strength of the polycarbonate laminate 10. The substrate layer 1 can be a single layer or a multilayer, but is preferably a single layer from the viewpoints of improving formability, adhesion, and transparency.

[0023] In this embodiment, the hard coat layer 2 is provided so as to be in contact with both surfaces of the substrate layer 1. The hard coat layer 2 may cover the entire surface of the substrate layer 1, may cover a part of the surface, or may cover the surface discontinuously.

[0024] The base layer 1 preferably has optical transparency (visible light transparency). The base layer 1 may be colorless, or may be colored in red, blue, yellow, or the like with a colorant described below, as long as the base layer 1 maintains optical transparency.

[0025] The thickness of the substrate layer 1 is preferably 3 mm or more, more preferably 5 mm or more, and even more preferably 8 mm or more. This allows for improved strength while maintaining good formability. On the other hand, the thickness of the substrate layer 1 is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 12 mm or less. This allows for improved formability while maintaining good strength.

[0026] The thickness of the base layer 1 is preferably 93.00 to 99.99% of the total thickness of the polycarbonate laminate 10, and more preferably 95.00 to 99.90%.

[0027] (Resin composition for base layer) The base layer 1 is a resin layer containing a polycarbonate resin, and is formed using a resin composition for a base layer. Polycarbonate resins are excellent in transparency and mechanical strength such as rigidity, and also have high heat resistance.

[0028] Various resins can be used as the polycarbonate resin, but aromatic polycarbonate resins are preferred. Aromatic polycarbonate resins are synthesized, for example, by an interfacial polycondensation reaction between bisphenol and phosgene, or a transesterification reaction between bisphenol and diphenyl carbonate. A bisphenol-type polycarbonate resin having a skeleton derived from bisphenol is preferably used as the main material. By using such a bisphenol-type polycarbonate resin, the base layer 1 exhibits even greater strength.

[0029] The base layer 1 may contain various additives such as resins other than polycarbonate resin, ultraviolet absorbers, colorants, antioxidants, fillers, plasticizers, light stabilizers, heat ray absorbers, and flame retardants, as described below, so long as the transparency and mechanical strength of the polycarbonate laminate 10 are maintained. For example, when the base layer 1 is molded by extrusion molding, selecting a heat-resistant additive can suppress discoloration and maintain the transparency of the polycarbonate laminate 10.

[0030] When the base layer 1 contains a resin other than the above-mentioned polycarbonate resin, the proportion of the resin other than the polycarbonate resin is preferably 1 mass % or less, more preferably 0.5 mass % or less, and even more preferably 0.1 mass % or less, relative to the total amount of resin in the base layer 1, and it is even more preferable that the base layer does not contain any resin other than the polycarbonate resin.

[0031] When the substrate layer 1 contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 1 mass % or less, more preferably 0.5 mass % or less, even more preferably 0.1 mass % or less, and even more preferably no ultraviolet absorber is contained, relative to the total amount of the substrate layer 1. By setting the content of the ultraviolet absorber in the substrate layer 1 to the above upper limit or less, the transparency and functionality of the substrate layer 1 can be easily maintained.

[0032] As the colorant, known dyes and pigments may be used. When the base layer 1 contains a colorant, the content of the colorant is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less, based on the total amount of the base layer 1, and it is even more preferable that the base layer does not contain a colorant.

[0033] Examples of the dye include acid dyes, direct dyes, reactive dyes, and basic dyes, and one or more selected from these may be used in combination.

[0034] [Hard Coat Layer 2] The hard coat layer 2 constitutes at least one outer surface of the polycarbonate laminate 10. By providing the hard coat layer 2 on the substrate layer 1, the substrate layer 1 can be protected from the outside. The hard coat layer 2 can be a single layer or a multilayer, but is preferably a single layer from the viewpoints of improving formability, adhesion, and transparency.

[0035] The thickness of the hard coat layer 2 is preferably 15 μm or more, more preferably 20 μm or more, and even more preferably 25 μm or more. This improves the strength of the protective layer and suppresses breakage and cracking. Furthermore, from the viewpoint of improving surface hardness, the thickness of the hard coat layer 2 may be 26 μm or more. On the other hand, the thickness of the hard coat layer 2 is preferably 80 μm or less, more preferably 60 μm or less. Conventionally, attempts to increase the thickness of the hard coat layer 2 to enhance hardness have tended to result in curling and cracking due to cure shrinkage. However, in the polycarbonate laminate 10 of this embodiment, even when the thickness of the hard coat layer 2 is increased, excellent crack resistance is achieved, so that both improved hardness and crack resistance can be achieved. Furthermore, from the viewpoint of achieving a thinner film, the thickness of the hard coat layer 2 may be preferably 40 μm or less, more preferably 38 μm or less.

[0036] The ratio of the thickness of the hard coat layer 2 to the total thickness of the polycarbonate laminate 10 is preferably 0.1% or more and 2.0% or less, more preferably 0.2% or more and 1.0% or less, and even more preferably 0.3% or more and 0.8% or less.

[0037] The pencil hardness of the surface on the hard coat layer 2 side is preferably 3H or more, and more preferably 4H or more, thereby achieving higher levels of hardness and crack resistance.

[0038] (Resin Composition for Hard Coat Layer) The hard coat layer 2 is formed using a resin composition for hard coat layer. The hard coat layer 2 contains a cured product of the resin composition for hard coat layer.

[0039] The resin composition for the hard coat layer preferably contains a cyclic ether compound. In particular, the cyclic ether compound preferably contains an epoxy ring and / or an oxetane ring. This allows for high hardness while improving crack resistance. While the details of the reason for this are unclear, it is believed that ring-opening polymerization of the epoxy ring and the oxetane ring makes it difficult for cure shrinkage to occur, thereby making it difficult for cracks to occur.

[0040] Furthermore, examples of the cyclic ether compound of the present embodiment include condensates of silane compounds represented by the following formula (1).

[0041] A-R １ -Si(OR ２ ) ｎ R ３ ３－ｎ (1) In formula (1), R １ represents a substituted or unsubstituted alkylene group having 1 to 16 carbon atoms, and R ２ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ３ represents a hydrogen atom or a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 25 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms. n represents an integer of 2 or 3. A represents a glycidyloxy group or an alicyclic epoxy group.

[0042] The cyclic ether compound of the present embodiment is a compound represented by the formula (1) Si—OR ２ The silane compound represented by formula (1) is obtained by hydrolysis and condensation of two or three (-OR ２ ) is preferably present.

[0043] In formula (1), R １ is preferably an alkylene group having 1 to 3 carbon atoms from the viewpoint of increasing the surface hardness of the hard coat layer 2. １ Examples of the substituent of R include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, and a phenyl group. From the viewpoint of improving crack resistance, however, R １ is preferably unsubstituted. ２ The number of carbon atoms in R is preferably 1 to 3 in order to improve hardness. ３ Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an isopropyl group, an isobutyl group, a cyclohexyl group, an ethylhexyl group, a benzyl group, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and a phenethyl group.

[0044] In formula (1), A is a glycidyloxy group or an alicyclic epoxy group, and is preferably an alicyclic epoxy group from the viewpoint of improving surface hardness. An example of the alicyclic epoxy group is a 3,4-epoxycyclohexyl group. On the other hand, A is preferably a glycidyloxy group from the viewpoint of increasing the flexibility and crack resistance of the hard coat layer 2.

[0045] Specific examples of the silane compound represented by formula (1) include (3,4-epoxycyclohexyl)methyldimethoxysilane, (3,4-epoxycyclohexyl)dimethylmethoxysilane, (3,4-epoxycyclohexyl)triethoxysilane, (3,4-epoxycyclohexyl)methyldiethoxysilane, (3,4-epoxycyclohexyl)dimethylethoxysilane, {(3,4-epoxycyclohexyl)methyl}trimethoxysilane, {(3,4-epoxycyclohexyl)methyl}methyldimethoxysilane, {(3,4-epoxycyclohexyl)methyl}dimethylmethoxysilane, {(3,4-epoxycyclohexyl)methyl}triethoxysilane, {(3,4-epoxycyclohexyl)methyl}methyldiethoxysilane, {(3,4-epoxycyclohexyl)methyl}dimethylethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}trimethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}methyldimethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}dimethylmethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}triethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}methyldiethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}dimethylethoxysilane, {3-(3,4-epoxycyclohexyl)propyl {3-(3,4-epoxycyclohexyl)propyl}trimethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}methyldimethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}dimethylmethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}triethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}methyldiethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}dimethylethoxysilane.

[0046] The cyclic ether compound produced by hydrolysis and condensation of the silane compound may contain a mixture of a structure in which all three alkoxy groups of a silane compound having a unit structure in which n=3 in formula (1) have undergone a condensation reaction to form an Si—O—Si bond, and a structure in which two of the three alkoxy groups have undergone a condensation reaction to form an Si—O—Si bond.

[0047] When a cyclic ether compound is obtained by condensation of a silane compound, a plurality of types of silane compounds may be condensed. For example, a silane compound in which A in formula (1) is an alicyclic epoxy group may be condensed with a silane compound in which A in formula (1) is a glycidyloxy group.

[0048] The hydrolysis and condensation reactions in the synthesis process of the cyclic ether compound of this embodiment are preferably carried out in the presence of a neutral salt catalyst, which can prevent the epoxy group from being deactivated before, after, or during storage of the compound.

[0049] The neutral salt catalyst may be a salt composed of an acid and a base, and preferably a salt composed of an alkali metal or alkaline earth metal cation and a halogen anion. Specific examples of the neutral salt catalyst include lithium chloride, sodium chloride, potassium chloride, beryllium chloride, magnesium chloride, calcium chloride, lithium bromide, sodium bromide, potassium bromide, beryllium bromide, magnesium bromide, calcium bromide, lithium iodide, sodium iodide, potassium iodide, beryllium iodide, magnesium iodide, and calcium iodide.

[0050] The content of the cyclic ether compound in the resin composition for the hard coat layer is not particularly limited, but is preferably 30 parts by mass or more, more preferably 50 parts by mass or more, and even more preferably 70 parts by mass or more, per 100 parts by mass of the resin composition for the hard coat layer. By setting the content of the cyclic ether compound to be equal to or greater than the above-mentioned lower limit, the hardness of the hard coat layer 2 can be maintained well. On the other hand, the content of the cyclic ether compound in the resin composition for the hard coat layer is preferably 95% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less. By setting the content of the cyclic ether compound to be equal to or less than the above-mentioned upper limit, the curability of the hard coat layer 2 can be improved.

[0051] (Other Materials) The resin composition for hard coat layer may contain other materials in addition to the various materials described above. Examples thereof include a polymerization initiator, a leveling agent, a reactive diluent, a sensitizer, an ultraviolet absorber, a colorant, a stabilizer, a surfactant, an antioxidant, an anti-reducing agent, an antistatic agent, a surface conditioner, a hydrophilic additive, a filler, and a solvent, and one or more of these may be used in combination.

[0052] (Polymerization Initiator) Examples of the polymerization initiator include a thermal cationic polymerization initiator and a photo-cationic polymerization initiator. A thermal cationic polymerization initiator is a compound that generates an acid upon heating (thermal acid generator). A photo-cationic polymerization initiator is a compound that generates an acid upon irradiation with active energy rays, and the epoxy groups of the siloxane compound of formula (1) react with the generated acid, resulting in curing through intermolecular crosslinking. Examples of the photo-cationic polymerization initiator include one or more selected from strong acids such as toluenesulfonic acid or boron tetrafluoride; onium salts such as sulfonium salts, ammonium salts, phosphonium salts, iodonium salts, and selenium salts; iron-arene complexes; silanol-metal chelate complexes; sulfonic acid derivatives such as disulfones, disulfonyldiazomethanes, disulfonylmethanes, sulfonylbenzoylmethanes, imidosulfonates, and benzoin sulfonates; and organic halogen compounds.

[0053] [Others] The polycarbonate laminate 10 may further have other layers laminated on the hard coat layer 2 as needed. Examples of other layers include a decorative layer. This can enhance the design of the polycarbonate laminate 10. In order to obtain good transparency in the polycarbonate laminate 10, it is preferable not to provide an adhesive layer between the substrate layer 1 and the hard coat layer 2.

[0054] [Uses] The polycarbonate laminate 10 can also be used by being attached to curved window members found in vehicles such as automobiles, motorcycles, and trains, as well as in aircraft, ships, houses, etc. This window member can be applied to window members provided in vehicles and the like that are positioned between a person and an object that the person views, and can also be applied to window members that are positioned between various devices, such as sensors and display devices, provided in vehicles and the like, and the object.

[0055] <Method for producing polycarbonate laminate 10> The method for producing the polycarbonate laminate 10 includes the following steps: (Step 1) A step of extruding a resin composition for a base layer to form a base layer 1. (Step 2) A step of applying a resin composition for a hard coat layer onto the base layer 1 to form a hard coat layer 2 on the base layer 1. Each step will be described in detail below.

[0056] (Step 1) First, a resin composition for the base layer is prepared. For example, the resin composition for the base layer can be prepared by premixing a polycarbonate resin raw material and any additives using a mixer, followed by extrusion melt-kneading, granulating using a granulator, and pelletizing. The pelletized material is then extrusion-molded using a known extruder to obtain a sheet-like base layer 1. It is also possible to obtain a sheet-like material by directly melt-kneading the material in an extruder and extruding it from a die during lamination by extrusion without going through pelletization.

[0057] The extrusion method is a known method in which a resin is melt-extruded using an extruder to form the resin into a sheet.

[0058] (Step 2) Next, the resin composition for a hard coat layer is applied onto the substrate layer 1. The application method is not particularly limited, and examples thereof include known and commonly used application methods such as brush coating, roller coating, spray coating, dip coating, flow coater coating, roll coater coating, and electrodeposition coating. After application, the solvent is dried and the composition is cured, thereby forming a hard coat layer 2 on the substrate layer 1.

[0059] Before applying the resin composition for a hard coat layer, the surface of the base layer 1 may be subjected to a surface treatment such as a corona treatment or a plasma treatment. Also, an easy-adhesion layer or the like may be provided on the surface of the base layer 1.

[0060] Curing is carried out by irradiation with active energy rays or heating. This generates an acid from the cationic polymerization initiator, and the epoxy groups of the siloxane compound represented by formula (1) undergo ring-opening and cationic polymerization, thereby progressing the curing. UV rays are preferred as the active energy rays. The cumulative exposure dose of the active energy rays may be set depending on the type and amount of the photocationic polymerization initiator, the thickness of the film, and the like. The curing temperature is not particularly limited, but is preferably 150°C or less, and more preferably 100°C or less. On the other hand, the curing temperature is preferably 30°C or more, and may be 70°C or more. Heating may also be carried out after irradiation with active energy rays. Heating promotes the reaction of unreacted epoxy groups remaining in the hard coat layer 2, thereby further improving the hardness of the hard coat layer 2.

[0061] The polycarbonate laminate 10 can be manufactured through the above steps.

[0062] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted.

[0063] Next, the present invention will be described in detail with reference to examples, but the content of the present invention is not limited to the examples.

[0064] 1. Preparation of Raw Materials First, the raw materials used for each layer of the polycarbonate laminate are shown below.

[0065] [Substrate layer] Polycarbonate resin 1: Bisphenol A polycarbonate (manufactured by Mitsubishi Engineer-Plastics Corporation, "E2000FN") Polycarbonate resin 2: High hardness polycarbonate (manufactured by Mitsubishi Engineer-Plastics Corporation, "KH3560UR") Additive 1: Additive 1 was prepared by mixing 90.9% by mass of bisphenol A polycarbonate (manufactured by Mitsubishi Engineer-Plastics Corporation, "E2000FN"), 7.0% by mass of Rikemal S-100A (manufactured by Riken Vitamin Co., Ltd.), 2.0% by mass of Adekastab PEP-36 (manufactured by ADEKA Corporation), and 0.1% by mass of Solvent Violet 13 (manufactured by Taiyo Fine Chemical Co., Ltd.).

[0066] [Hard Coat Layer Material (Resin Composition)] The raw materials shown below were mixed in the proportions (parts by mass) shown in Table 1 to obtain hard coat layer material A and hard coat layer material B, respectively. (Raw Materials) Silicon-modified cyclic ether compound A: Synthesized according to the following procedure. 60 g of Shin-Etsu Chemical's "KBM-4803" and 5.4 g of Momentive Performance Materials' "SILQUEST A-186" were dissolved in 15 mL of 1-methoxy-2-propanol (PGME) to obtain a mixed solution. A solution of 0.01 g of magnesium chloride dissolved in 12 mL of water and 4.8 mL of methanol was gradually added dropwise to this mixed solution over 5 minutes. The mixture was then stirred at 80°C for 6 hours. After completion of the reaction, the solvent was removed using a rotary evaporator to obtain a silicon-modified cyclic ether compound. The obtained silicon-modified cyclic ether compound was dissolved in isobutyl acetate to a solids content of 70%, yielding siloxane-modified cyclic ether A. Photoacid generator 1: sulfonium salt type "CPI-101A" (manufactured by San-Apro Co., Ltd.) Silica particles 1: "PGM-AC-2140Y" (manufactured by Nissan Chemical Industries, Ltd.) Urethane (meth)acrylate 1: 7.8-functional urethane acrylate, "UV-1700B" (manufactured by Mitsubishi Chemical Corporation) (meth)acrylate monomer 1: bifunctional acrylate monomer, "A-BPE-4" (manufactured by Shin-Nakamura Chemical Co., Ltd.) Photopolymerization initiator 1: "Omnirad754" (manufactured by IGM Resin

[0067]

[0068] 2. Preparation of polycarbonate laminate (sheet) The UV curing conditions were as follows: an electrodeless UV lamp manufactured by FUSION Systems was used, the irradiation distance was 50 mm, the conveyor speed was 1.5 m / min, and the irradiation intensity was 500 mW / cm. ２ , cumulative light intensity 1700 mJ / cm ２ As a result, polycarbonate laminates (sheets) shown in Table 2 were produced by the following procedure.

[0069] Example 1 A resin composition for a substrate layer, consisting of 99% by mass of polycarbonate-based resin 1 for the substrate layer and 1% of additive 1, was extruded to form a substrate layer. The thickness of the substrate layer was 10 mm. Hard coat layer material A was applied to the surface of the obtained substrate layer, dried at 80°C for 5 minutes, and UV-cured to form a hard coat layer with a film thickness of 37 μm. This resulted in a polycarbonate laminate sheet.

[0070] Example 2 A polycarbonate laminate sheet was obtained in the same manner as in Example 1, except that the thickness of the hard coat layer was changed from 37 μm to 25 μm.

[0071] Comparative Example 1 A resin composition for a substrate layer, consisting of 99% by mass of polycarbonate-based resin 1 for the substrate layer and 1% of additive 1, was extruded to form a substrate layer. The thickness of the substrate layer was 10 mm. Hard coat layer material B was applied to the surface of the obtained substrate layer, dried at 80°C for 5 minutes, and UV-cured to form a hard coat layer with a film thickness of 25 μm. This resulted in a polycarbonate laminate sheet.

[0072] Comparative Example 2: A base layer resin composition consisting of 99% by mass of polycarbonate-based resin 1 and 1% by mass of additive 1 for the base layer and an intermediate layer resin composition consisting of 99% by mass of polycarbonate-based resin 2 and 1% by mass of additive 1 were co-extruded to form a laminate comprising the base layer and intermediate layer. The laminate had a combined thickness of 10 mm for the base layer and intermediate layer, and the intermediate layer was 200 μm thick. Hard coat layer material B was applied to the surface of the resulting intermediate layer, dried at 80°C for 5 minutes, and UV-cured to form a hard coat layer with a thickness of 15 μm. This produced a polycarbonate laminate sheet.

[0073] Comparative Example 3 A polycarbonate laminate sheet was obtained in the same manner as in Comparative Example 2, except that the thickness of the hard coat layer was changed from 15 μm to 25 μm.

[0074] 4. Measurement [Glossiness] After treating the polycarbonate laminate under conditions of 80°C, 50% RH, and 72 hours, the glossiness, which is the reflectance of light at an incident angle of 60°, of the surface on the hard coat layer side was measured in accordance with JIS Z 8741. The results are shown in Table 2. The device used was a handy glossmeter PG-1M (manufactured by Nippon Denshoku Industries Co., Ltd.).

[0075] 5. Evaluation The following measurements / evaluations were carried out on the obtained laminates. The results are shown in Table 2. Total light transmittance (%) The total light transmittance (%) of each laminate was determined in accordance with JIS K7361-1 (1997) using a haze meter (product name: NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.).

[0076] Hardness: In a pencil scratch hardness test in accordance with JIS K 5600-5-4, a pencil was pressed against the surface of the hard coat layer of the polycarbonate laminate at an angle of 45 degrees with a load of 750 g, and the presence or absence of scratches was confirmed. The pencil hardness was increased in order, and the maximum pencil hardness at which no scratches were observed was recorded as the "pencil hardness." The results are shown in Table 2.

[0077] Crack Resistance After treating the polycarbonate laminate under conditions of 80°C, 50% RH for 72 hours, the presence or absence of cracks was visually observed and evaluated according to the following criteria: OK: No change in appearance was observed. NG: Cracks were observed in the hard coat layer.

[0078]

[0079] This application claims priority based on Japanese Patent Application No. 2024-050766, filed March 27, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0080] 10 Polycarbonate laminate 1 Base layer 2 Hard coat layer

Claims

1. A polycarbonate laminate comprising a substrate layer containing a polycarbonate resin and a hard coat layer constituting the outer surface, wherein the thickness of the hard coat layer is 20 μm or more and 80 μm or less, and the gloss, which is the reflectance of light at an incident angle of 60°, measured in accordance with JIS Z 8741 on the surface of the hard coat layer side after treating the polycarbonate laminate under conditions of 80°C, 50% RH, and 72 hours, is 97 or more.

2. A polycarbonate laminate according to claim 1, wherein the ratio of the thickness of the hard coat layer to the total thickness of the polycarbonate laminate is 0.1% or more and 2.0% or less.

3. The polycarbonate laminate according to claim 1 or 2, wherein the hard coat layer contains a cyclic ether compound.

4. A polycarbonate laminate according to claim 3, wherein the cyclic ether compound contains an epoxy ring and / or an oxetane ring.

5. A polycarbonate laminate according to any one of claims 1 to 4, wherein the hard coat layer is laminated so as to be in direct contact with the substrate layer.

6. A polycarbonate laminate according to any one of claims 1 to 5, wherein the thickness of the polycarbonate laminate is 3 mm or more and 20 mm or less.

7. A polycarbonate laminate according to any one of claims 1 to 6, wherein the surface on the substrate layer side has a pencil hardness of 2B or more and B or less.

8. A polycarbonate laminate according to any one of claims 1 to 7, for use in display screens and / or windows.

9. A display screen using the polycarbonate laminate according to any one of claims 1 to 8.

10. A window using a polycarbonate laminate according to any one of claims 1 to 8.

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