Laminate

Abstract

To provide a laminate which retains bonding strength to difficult-to-bond materials under room temperature and high temperature environments, is free from bonding failure or visual defects due to water wetting or humidity, and prevents deformation of the adherend.SOLUTION: A laminate comprises at least a layer A and a layer B, wherein the layer A is a film containing 90.0 mass% or more of a polycarbonate resin, the layer B contains 80.0 mass% or more of a polycarbonate resin and 5.0 mass% or more and 15.0 mass% or less of a polycaprolactone resin, and the laminate has a total light transmittance of 70% or more both before and after immersion in a 95°C aqueous solution containing a surfactant.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminate.

Background Art

[0002] Generally, adhesives or pressure-sensitive adhesives are used to bond base materials such as films and papers. As materials used as such adhesives, there is a hot-melt adhesive containing a thermoplastic resin. And hot-melt adhesives are classified into rubber-based, acrylic-based, and silicone-based according to the materials used, and are classified into organic solvent solutions, emulsions, solids (such as hot melts), and aqueous solutions according to their states.

[0003] Next, the main uses of hot-melt adhesives include bonding of difficult-to-bond materials (polycarbonate: PC, polypropylene: PP, polyethylene: PE, polytetrafluoroethylene: PTFE, ethylene propylene diene rubber: EPDM, etc.), temporary bonding (in addition to the adhesion process of nameplates, the adhesion coating of labels and films, etc.), primary processing of adhesive members (such as double-sided adhesive tapes), re-peel adhesion (higher re-adhesion and easier peelability are required than in temporary bonding), etc., and it is necessary to select a hot-melt adhesive suitable for each use.

[0004] On the other hand, in recent years, there have been demands for following complex shapes such as electronic device components, maintaining adhesive strength in a high-temperature environment exceeding 100 °C due to repair of heater members of home appliances, etc., and further preventing a decrease in adhesive strength and preventing appearance defects due to a humid environment or water wetting.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In response to the above requirements, conventional thermoplastic resins have insufficient heat resistance and water resistance, and there are problems in maintaining the adhesion to difficult-to-bond materials in high-temperature environments. Therefore, a proposal (Patent Document 1) has been made to crystallize thermoplastic resins for the purpose of improving heat resistance and water resistance. However, it is necessary to change the thermoplastic resin according to various difficult-to-bond materials, and since the thermoplastic resin hardens at room temperature, there are problems such as inability to follow complex shapes and a decrease in adhesion. In addition, when crystallized, the thermoplastic resin turns white and poor appearance (opaque) occurs, or the adherend, which is a difficult-to-bond material, cannot withstand the lamination temperature during lamination, and deformations such as warping and melting occur. In order to solve such problems, it is an object of the present invention to provide a laminate that maintains adhesion to difficult-to-bond materials both in a normal-temperature environment and in a high-temperature environment, can follow complex shapes, suppresses the occurrence of adhesion failure and poor appearance due to the influence of water wetting and humidity, and can suppress deformation of the difficult-to-bond material during lamination.

Means for Solving the Problems

[0007] As a result of intensive studies to solve the above problems, the present invention has found the following solutions and has reached the present invention. That is, the laminate of the present invention is as follows. (1) A laminate having at least layer A and layer B, wherein layer A is a film containing 90.0% by mass or more of a polycarbonate resin, layer B contains 80.0% by mass or more of a polycarbonate resin and 5.0% by mass or more and 15.0% by mass or less of a polycaprolactone resin, and the total light transmittance of the laminate before and after immersing the laminate in an aqueous solution at a temperature of 95 °C containing a surfactant is 70% or more in both cases. A laminate characterized by this. (2) The polycarbonate resin contained in layer B contains a hydroxyl group in its molecular chain, layer B has two or more flow start temperatures, the flow start temperature of layer B is 100 °C or more and 140 °C or less, and the thickness of layer B is 5 μm or more and 40 μm or less. The laminate according to (1), characterized by this. (3) The laminate according to (1) and (2), characterized in that the flow start temperature of the layer B is -5°C or higher and 25°C or lower on the low-temperature side, 40°C or higher and 185°C or lower on the high-temperature side, and the weight average molecular weight of the layer B is 5000 or higher and 30000 or lower. (4) Among the two surfaces of the laminate, on the surface A formed by the layer A, a silicone resin is present, and the amount of the silicone resin is 0.001 kcps or more and 0.10 kcps or less. The laminate according to any one of (1) to (3). (5) The laminate having at least layer A, layer B, layer C, and layer D in this order, wherein the layer C contains 45.0% by mass or more of polyethylene terephthalate resin, and the layer D contains 90.0% by mass or more of silicone resin. The laminate according to any one of (1) to (4). (6) The laminate according to any one of (1) to (5), characterized in that the peel strength between the layer B and the layer C is 0.1 N / cm or more and 1.0 N / cm or less. (7) A laminated structure formed by laminating the laminate according to any one of (1) to (6) and an adherend, wherein the adherend contains a polycarbonate resin, and the content of the polycarbonate resin is 50.0% by mass or more based on the whole adherend. A laminated structure characterized by this.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a laminate that maintains the adhesive strength with an adherend that is a difficult-to-adhere material both in a normal temperature environment and in a high temperature environment, can follow a complex shape, and further suppresses the occurrence of poor adhesion and poor appearance due to the influence of water wetting and humidity, and can suppress the deformation of the difficult-to-adhere material during lamination.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0010] The laminate of the present invention is a laminate having at least layer A and layer B. The layer A is a film containing 90.0% by mass or more of a polycarbonate resin. The layer B contains 80.0% by mass or more of a polycarbonate resin and 5.0% by mass or more and 15.0% by mass or less of a polycaprolactone resin. The total light transmittance of the laminate before and after immersing the laminate in an aqueous solution at a temperature of 95°C containing a surfactant is 70% or more in both cases. The laminate is characterized by this.

[0011] With the above configuration, in the laminate of the present invention, the adhesive strength with an adherend that is a difficult-to-adhere material is maintained in both normal temperature environments and high temperature environments, it can follow complex shapes, and furthermore, the occurrence of adhesion failure and appearance failure due to the influence of water wetting and humidity is suppressed, and deformation of the difficult-to-adhere material during lamination can be suppressed. Hereinafter, a preferred aspect of the laminate of the present invention will be specifically described. In the present invention, normal temperature means 10°C or more and 25°C or less, and high temperature means 80°C or more and 120°C or less.

[0012] In the present invention, the flow start temperature of a layer means the flow start temperature of the composition constituting the layer, and the weight average molecular weight of a layer means the average of the weight average molecular weights of each resin contained in the composition constituting the layer.

[0013] (Description of the adherend) The adherend described above is not particularly limited, but a difficult-to-adhere material is assumed for hot melt adhesion applications. More specifically, for example, molded articles made of polycarbonate (PC), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), and ethylene propylene diene rubber (EPDM) can be mentioned. Among them, polycarbonate (PC) is suitable for heat-resistant and water-resistant applications and is preferably used as the adherend. Further, the adherend may contain a plurality of materials. Also, when the adherend contains a plurality of materials, that is, when the adherend contains a plurality of types of resins, it is preferable that one of the plurality of types of resins is a polycarbonate resin. The content of the polycarbonate resin is preferably 50.0% by mass or more, more preferably 60.0% by mass or more, based on the whole adherend. As will be described later, when the polycarbonate resin is contained in an amount of 80.0% by mass or more based on the whole layer B, the adhesion between the adherend and layer B can be improved by the adherend containing a specific amount of the polycarbonate resin. The shape of the adherend is not particularly limited, but a sheet shape is preferably used.

[0014] Next, the laminate of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic view of an embodiment of the laminate of the present invention including layer A and layer B. Shown in FIG. 1 is a laminate in which layer A (indicated by reference numeral 1) and layer B (indicated by reference numeral 2) are laminated. Further, FIG. 2 shows a schematic view of a laminate in a mode different from the laminate shown in FIG. 1, that is, a schematic view of an embodiment of the laminate of the present invention including layer A, layer B, layer C, and layer D in this order. That is, shown in FIG. 2 is a laminate in which layer A (indicated by reference numeral 1), layer B (indicated by reference numeral 2), layer C (indicated by reference numeral 3), and layer D (indicated by reference numeral 4) are laminated in this order.

[0015] (Layer B: Layer of hot melt adhesive) Layer B included in the laminate of the present invention is a hot-melt adhesive layer. Here, the hot-melt adhesive refers to a material that melts at a specific temperature or higher and exhibits adhesiveness. That is, it is an adhesive that is melted by applying heat to bond substrates or the like, and a thermoplastic resin is often used as the hot-melt adhesive material. And the above layer B contains a polycarbonate resin. By configuring the above layer B from a hot-melt adhesive containing a polycarbonate resin, the adhesive strength between the laminate of the present invention and the adherend to be laminated, heat resistance, etc. become excellent. Further, the flow start temperature of layer B is preferably 100°C or higher and 120°C or lower. When the flow start temperature is 100°C or higher and 120°C or lower, the adhesive does not melt in a high-temperature environment, so the adhesiveness can be maintained, and peeling of the substrate and the adherend due to heat can be suppressed. Also, when a plurality of resins and additives are mixed in layer B, there may be a plurality of flow start temperatures. In the case of the present invention, the melting start temperature of the lowest temperature is taken as the melting start temperature of layer B.

[0016] As described above, it is preferable that layer B contains two or more resins. In this case, layer B will have two or more flow start temperatures. Preferably, the low-temperature side is -5°C or higher and 25°C or lower, and the high-temperature side is 40°C or higher and 185°C or lower. When there are three or more flow start temperatures, the flow start temperature on the lowest temperature side is taken as the low-temperature side, and the flow start temperature on the highest temperature side is taken as the high-temperature side. If the flow start temperature on the low-temperature side is -5°C or higher or the flow start temperature on the high-temperature side is 40°C or higher, the hot-melt resin does not dissolve at high temperatures, and the adhesion in a high-temperature environment becomes more excellent. Also, when the flow start temperature on the low-temperature side is 25°C or lower and the flow start temperature on the high-temperature side is 185°C or lower, layer B becomes soft at room temperature, so it can follow an adherend with a complex shape. The flow start temperature is measured according to JIS K 7121:2012 by DSC (differential scanning calorimetry).

[0017] When layer B is subjected to gel permeation chromatography (GPC) analysis (hereinafter sometimes referred to as GPC analysis), it is preferable that the weight average molecular weight is 5,000 or more and 30,000 or less. When the weight average molecular weight of layer B (polystyrene equivalent value, measured by gel permeation chromatography (GPC)) is 5,000 or more and 30,000 or less, the cohesive force and the adhesive strength, particularly the adhesive strength at high temperature, can be maintained, the melt viscosity during coating decreases, and the production efficiency is increased in the process of laminating layer A. Also, when thermally bonding layer B to layer C, it is not necessary to increase the bonding temperature, and as a result, heat damage such as thermal shrinkage, decomposition, and melting of the base material and / or layer C can be prevented. Further, it is more preferable that the weight average molecular weight in the case of performing GPC analysis on layer B is 10,000 or more and 25,000 or less.

[0018] The method for GPC analysis of layer B shall be as follows. Take 0.03 g of layer B and measure it with a GPC measuring device (Nexra manufactured by Shimadzu Corporation, column GPC - 801, column temperature 40 °C) using a solution of about 15 g and about 0.2 mass% diluted with tetrahydrofuran, and determine it by converting using polystyrene as a standard substance (see JIS K7252 - 1:2016).

[0019] Due to the above circumstances, it is preferable that layer B has the following characteristics. That is, the flow start temperature of layer B is -5 °C or more and 25 °C or less on the low - temperature side and 40 °C or more and 185 °C or less on the high - temperature side, and further, the weight average molecular weight of layer B is 5,000 or more and 30,000 or less.

[0020] Layer B included in the laminate of the present invention contains polycaprolactone (PCL) resin in addition to the polycarbonate resin. The method for obtaining the polycaprolactone (PCL) resin is not particularly limited, but it can be obtained by ring-opening polymerization of ε-caprolactone, which is one of the lactones required for obtaining the polycarbonate diol described later. Since the polycaprolactone resin is produced from the raw material of the polycarbonate resin, it can be mixed while maintaining the properties of the polycarbonate resin. Further, by including polycaprolactone (PCL) resin having a lower flow start temperature than the polycarbonate resin in layer B, the melting start temperature can be lowered while maintaining the total light transmittance of layer B, and the flow start temperature of layer B can be changed by changing the blending amount.

[0021] In addition to the above polycarbonate resin and polycaprolactone resin, layer B preferably contains at least one resin selected from the group consisting of polyester resin, (meth)acrylic resin, polyolefin resin, ethylene-vinyl acetate copolymer resin, polyamide resin, and chloroprene resin. Furthermore, it is preferable that the resins other than these polycarbonate resin and polycaprolactone resin have an aromatic skeleton. Having an aromatic skeleton is preferable because the cohesive force of the resin constituting layer B is improved, and the adhesion strength to layer A and the adherend is improved. Also, layer B may contain only one type of resin other than the above-described polycarbonate resin and polycaprolactone resin, or may contain a plurality of resins.

[0022] As a method for obtaining a polycarbonate diol having an integral value ratio of the present embodiment, for example, a method using a dibasic acid or dibasic acid ester, a lactone, or a polyester polyol can be mentioned. The dibasic acid is not particularly limited, and examples thereof include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, tartaric acid, glutamic acid, sebacic acid, and brassilic acid. The dibasic acid ester is not particularly limited, and examples thereof include methyl, ethyl, butyl, isobutyl, 2-ethylhexyl, isodecyl, and isononyl esters of the above dibasic acids. The lactone is not particularly limited, and examples thereof include α-acetolactone, β-propiolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone. The polyester polyol is not particularly limited, and for example, it can be obtained by subjecting a dibasic acid alone or a mixture of two or more kinds and a polyhydric alcohol alone or a mixture of two or more kinds to a condensation reaction. The dibasic acid is not particularly limited, and examples thereof include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid. The polyhydric alcohol is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerin, pentaerythritol, 2-methylolpropanediol, and ethoxylated trimethylolpropane. Or, although not particularly limited, for example, polycaprolactones and the like obtained by ring-opening polymerization of lactones such as ε-caprolactone using a polyhydric alcohol can also be used as the polyester polyol. When a lactone is used, it is preferable because the heat and water resistance of the obtained polycarbonate diol is maintained, and it is more preferable to use one or more lactones selected from γ-butyrolactone, δ-valerolactone, and ε-caprolactone.As specific methods, for example, there are methods of polymerizing polycarbonate diol by mixing dibasic acid or dibasic acid ester, lactone, polyester polyol with a diol and a carbonate as raw materials, or adding dibasic acid or dibasic acid ester, lactone, polyester polyol to a general polycarbonate diol and heating at a temperature of 100°C or higher and 200°C or lower for 30 minutes or longer and 5 hours or shorter.

[0023] In the present invention, layer A described later is a film containing 90.0% by mass or more of a polycarbonate resin, and further, layer B contains 80.0% by mass or more and 95.0% by mass or less of a polycarbonate resin. In the above case, by layer B containing 80.0% by mass or more of a polycarbonate resin, the adhesion to layer A and the adherend described later can be improved, and for example, the occurrence of peeling between layer B and layer A during shearing processing can be suppressed. Also, by containing 80.0% by mass or more of a polycarbonate resin, layer B has excellent transparency. Further, by layer B containing 95.0% by mass or less of a polycarbonate resin, it becomes possible to bond to the adherend at a temperature lower than the melting start temperature of the polycarbonate resin. Also, layer B preferably contains 5.0% by weight or more and 15.0% by weight or less of a polycaprolactone (PCL) resin. In the above case, by layer B containing 5.0% by weight or more of a polycaprolactone (PCL) resin, the adhesion to the adherend and layer A can be improved. Also, by containing 15.0% by weight or less of a polycaprolactone (PCL) resin, the transparency of layer B can be maintained.

[0024] The method for identifying the resin of layer B is not particularly limited. For example, only layer B can be cut out from the laminate, and the IR spectrum can be measured using the ATR method (refer to JIS K0117:2017) of a Fourier transform infrared analyzer, generally known as an FT-IR device (for example, Shimadzu Corporation, IR Spirit), and it can be identified by comparing it with the standard sample spectrum recorded in the database in advance. Also, using a thermal analysis gas chromatograph mass spectrometer, generally known as a GC-MS device (for example, Shimadzu Corporation, GCMS-QP2020NX), the mass spectra of the molecular ions and decomposition ions of layer B can be measured, and the resin can be quantified by comparing it with the general compound spectrum measured in advance using a calibration curve.

[0025] The polycarbonate resin of layer B is not particularly limited, but it can be synthesized and manufactured by ordinary methods. For example, there are a melt polymerization method in which raw materials and a catalyst are charged and heated at a temperature above the melting point of the product, a solid-phase polymerization method in which polymerization is carried out below the melting point of the product, and a solution polymerization method using a solvent. Any method may be adopted, but from the viewpoint of obtaining a polycarbonate with an appropriate degree of polymerization in line with the object of the present invention and economic efficiency, the melt polymerization method is preferred.

[0026] Also, the thickness of layer B is preferably 5 μm or more and 40 μm or less, more preferably 10 μm or more and 35 μm or less. When the thickness of layer B is 5 μm or more and 40 μm or less, it is possible to suppress the peeling of layer B due to scratches during processing and the generation of pinholes in layer B by improving the adhesion strength between layer B and the adherend. Also, when cutting the laminate into a predetermined size with a slit blade, a Thomson blade, etc., it is possible to prevent layer B from adhering to the surface of the slit blade or Thomson blade.

[0027] Here, the polycarbonate resin used in the present invention can be easily obtained by either a known transesterification method in which an aromatic dihydroxy compound and a carbonic acid diester are reacted in the presence of a transesterification catalyst such as a basic compound, or a known interfacial polycondensation method in which the aromatic dihydroxy compound and phosgene, etc. are reacted in the presence of an acid binder.

[0028] As the aromatic dihydroxy compound, specifically, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)phenylmethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxy-3-t-butylphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-phenylphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxy-3-methoxyphenyl)propane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone and the like can be mentioned.

[0029] Among them, 2,2-bis(4-hydroxyphenyl)propane (that is, bisphenol A) is more preferable in terms of impact resistance and heat resistance when used as a polycarbonate resin, stability as an aromatic dihydroxy compound, and the fact that although the amount of impurities contained therein is small, it is easily available. In the present invention, a plurality of the above aromatic dihydroxy compounds may be used in combination as necessary.

[0030] In addition, examples of the above-mentioned carbonic acid diesters include aromatic carbonic acid diesters such as diphenyl carbonate, ditolyl carbonate, bis(2-chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, and bis(4-phenylphenyl) carbonate. In addition, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, etc. can also be used as desired. Among these, diphenyl carbonate is preferred in terms of reactivity, stability against coloring of the resulting resin, and further cost.

[0031] The polycarbonate resin used in the present invention may be synthesized by an interfacial polymerization method, a melt polymerization method, or may be synthesized by a method such as a solid-phase polymerization method or a thin-film polymerization method. Further, it is preferable that at least a part of the above polycarbonate resin is terminated with end groups derived from a hydroxy compound.

[0032] The proportion of the end groups is preferably 60 mol% or more based on the total amount of end groups, and the terminal hydroxyl group concentration can be measured by spectroscopic measurement using a Ti complex. Further, the terminal hydroxyl group concentration can also be measured by 1H-NMR analysis. The terminal hydroxyl group concentration by the same evaluation is preferably 1,500 ppm or less, more preferably 1,000 ppm or less. If the hydroxyl end groups are within this range or the amount of the blocked end groups is within this range, a sufficient effect of increasing the molecular weight can be obtained by the transesterification reaction with the diol compound.

[0033] From the above circumstances, layer B contains at least a polycarbonate resin. And this polycarbonate resin contains a hydroxyl group in its molecular chain. The above layer B has two or more flow start temperatures. The pre-flow start temperature of the above layer B is 100°C or higher and 140°C or lower. Further, the thickness of the above layer B is preferably 5 μm or more and 40 μm or less. By layer B having the above characteristics, the adhesion to an adherend that is a difficult-to-adhere material is maintained in both normal temperature and high temperature environments, it can follow a complex shape, and further, the occurrence of adhesion failure and appearance failure due to the influence of water wetting and humidity is suppressed.

[0034] (Layer A: Polycarbonate resin-containing film) For layer A used in the present invention, a film containing 90.0 mass% or more of a polycarbonate resin is used from the viewpoints of dimensional stability, durability, etc. As the resin components of the above film, polyester, polyolefin, polyamide, polyester amide, polyether, polyimide, polyamideimide, polystyrene, polycarbonate, poly-ρ-phenylene sulfide, polyether ester, polyvinyl chloride, poly(meth)acrylate can be mentioned, and copolymers, blends, and further cross-linked compounds thereof can also be used. Layer A used in the present invention is a film containing 90.0 mass% or more of a polycarbonate resin. Such a film is excellent in followability to an adherend and transparency. Since layer A contains 90.0 mass% or more of a polycarbonate resin, and further, the above layer B contains 80.0 mass% or more of a polycarbonate resin, the adhesion between layer A and layer B becomes excellent, and for example, the occurrence of peeling between layer B and layer A during shearing processing can be suppressed.

[0035] The thickness of layer A used in the present invention is not particularly limited, but is preferably 500 μm or less from the viewpoint of ensuring the flexibility of the laminate, and is preferably 10 μm or more from the viewpoint of ensuring strength against tension and impact. Further, from the viewpoint of ease of processing and handling of layer A, the thickness is preferably 20 μm or more and 300 μm or less, and more preferably 30 μm or more and 250 μm or less.

[0036] (Layer C: Release layer substrate) In the laminate of the present invention, in addition to layer A and layer B, it is preferable to include layer C and layer D in this order. Here, the layer C that can be used in the present invention is not particularly limited, but for example, a plastic film, synthetic paper, paper, or a composite sheet with surface treatment is preferable, and among them, a plastic film is preferable from the viewpoints of dimensional stability, durability, etc. As the material of the plastic film, polyester, polyolefin, polyamide, polyester amide, polyether, polyimide, polyamideimide, polystyrene, poly-ρ-phenylene sulfide, polyether ester, polyvinyl chloride, poly(meth)acrylate can be mentioned, and copolymers, blends, and further cross-linked compounds thereof can also be used.

[0037] Furthermore, among the above plastic films, a film made of a polyester resin, for example, polyethylene terephthalate resin, polyethylene 2,6-naphthalate resin, polyethylene α,β-bis(2-chlorophenoxy)ethane 4,4'-dicarboxylate resin, polybutylene terephthalate resin, polycarbonate resin, etc. is preferable. Considering comprehensively the quality such as mechanical properties and workability, and economy among these, a film containing 45.0% by mass or more of polyethylene terephthalate resin is more preferable. Also, layer C may be a film composed only of polyethylene terephthalate resin.

[0038] The thickness of layer C used in the present invention is not particularly limited, but from the viewpoint of ensuring the flexibility of the laminate, it is preferably 500 μm or less, and from the viewpoint of ensuring the strength against tension and impact, it is preferably 10 μm or more. Further, when the above plastic film is used for layer C, from the viewpoint of ease of film processing and handling, the thickness of layer C is preferably 20 μm or more and 300 μm, more preferably 30 μm or more and 250 μm.

[0039] Also, the peeling force between the layer B and the layer C is not particularly limited, but considering prevention of dropping during film conveyance and peelability during use, it is preferably 0.1 N / cm or more and 1.0 N / cm or less.

[0040] (Layer D: Release layer) In the laminate of the present invention, in addition to the layer A and the layer B, it is preferable to include the layer C and the layer D in this order. Here, the layer D that can be used in the present invention preferably contains a silicone resin as a main component in order to impart releasability to the layer C. Here, the phrase "containing a silicone resin as a main component" means that when the total components constituting the layer D are 100.0% by mass, the content of the silicone resin in the layer D is 90.0% by mass or more. By using a silicone resin as the main component of the layer D, releasability can be imparted. Therefore, when the laminate of the layer B / layer C / layer D is pulled out from the roll, generation of peeling between the layer B and the layer C is suppressed, and separation between the layer B and the layer D can be achieved, so that the laminate of the layer B / layer C / layer D can be maintained, and the surface of the layer B on the side opposite to the surface on the layer C side can be adhered to the layer A. In the laminate of the layer B / layer C / layer D in the form of a roll, the layer B is adjacent to the layer D and the layer C.

[0041] Here, the silicone resin refers to a silicone-based compound that has been conventionally known as a silicone-based release agent. Silicone is a polymer composed of a main chain formed by alternating bonds of silicon and oxygen having an organic group (for example, an alkyl group or a phenyl group). For example, silicone-based compounds having dimethylpolysiloxane as a basic skeleton are well known.

[0042] The silicone resin is not particularly limited as long as the effects of the present invention are not impaired, but an addition reaction type silicone resin, a condensation polymerization reaction type silicone resin, an ultraviolet curable type silicone resin, an electron beam curable type silicone resin, and a solventless type silicone resin are preferable. From the viewpoint of improving productivity, an addition reaction type silicone resin is more preferable, and a silicone resin obtained by heat-curing a polydimethylsiloxane containing terminal vinyl groups and a hydrogen siloxane under a platinum catalyst is even more preferable.

[0043] By making layer D mainly composed of a silicone resin, it becomes possible to make the surface free energy of layer D 30 mN / m or less. By making the surface free energy of layer D 30 mN / m or less, layer D can be used as a release layer, and when the laminate of layer B / layer C / layer D is pulled out from a roll, generation of peeling between layer B and layer C is suppressed, and separation between layer B and layer D is possible, so that the laminate of layer B / layer C / layer D can be maintained, and the surface of layer B on the side opposite to the surface on the layer C side can be adhered to layer A, whereby the layer A / layer B / layer C / layer D laminate can be formed.

[0044] The coating thickness of layer D is preferably 0.02 or more and 0.50 μm or less in terms of the coating thickness after drying, and more preferably 0.05 μm or more and 0.30 μm or less. By making the coating thickness 0.02 μm or more and 0.50 μm or less, variation in the peeling performance within the plane of layer D can be prevented, and the amount of silicone migration after drying can be reduced.

[0045] Due to the above circumstances, the laminate of the present invention preferably has at least layer A, layer B, layer C, and layer D in this order, and layer D contains 90.0% by mass or more of a silicone resin.

[0046] (Method for producing a laminate) The manufacturing method of the laminate of the present invention is not particularly limited, but a preferred manufacturing method will be described below. Also, the manufacturing method exemplified here is a method for manufacturing a laminate including layer A, layer B, layer C, and layer D in this order.

[0047] A preferred embodiment of the manufacturing method of the present invention is an embodiment having the following steps 1 to 4 in this order. Step 1: A step of laminating layer D on one side of layer C. Step 2: A step of laminating layer B on the layer C side of the layer C / layer D laminate produced in step 1. Step 3: A step of bonding layer A to the layer B surface of the layer B / layer C / layer D produced in step 2.

[0048] <Step 1> Step 1 is a step of laminating layer D on one side of layer C. First, a coating composition of layer D mainly composed of a silicone resin is prepared. From the viewpoint of improving coatability with respect to the substrate, it is preferable to mix an organic solvent in the coating composition. The organic solvent is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include ethyl methyl ketone, methyl isobutyl ketone, butyl acetate, ethyl acetate, methanol, isopropanol, cyclohexanone, toluene, xylene, and the like.

[0049] Thereafter, although not particularly limited as long as the effects of the present invention are not impaired, for example, by comma coating method, applicator method, dip coating method, roller coating method, wire bar coating method, reverse coating method, kiss coating method, gravure coating method, die coating method (U.S. Patent No. 2681294), etc., it is preferable to form layer D by applying a composition for obtaining layer D, and from the viewpoint of processability, the wire bar coating method, reverse coating method, and gravure coating method are more preferable.

[0050] <Step 2> Step 2 is a step of laminating layer B on the layer C side of the layer C / layer D created in Step 1. First, a coating composition of layer B mainly composed of a polycarbonate resin and containing a polycaprolactone resin is prepared. Here, the main component means that when all components constituting layer B are 100.0% by mass, the polycarbonate resin is contained in an amount of 80.0% by mass or more. It is preferable to contain the polycaprolactone resin in an amount of 5.0% by mass or more and 15.0% by mass or less. Also, from the viewpoint of improving coatability with respect to the substrate as in layer D, it is preferable to mix an organic solvent in the coating composition. The organic solvent is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include ethyl methyl ketone, methyl isobutyl ketone, butyl acetate, ethyl acetate, methanol, isopropanol, cyclohexanone, toluene, xylene, and the like.

[0051] Thereafter, although not particularly limited as long as the effects of the present invention are not impaired, layer B is preferably formed by applying a composition for obtaining layer B by a comma coating method, an applicator method, a dip coating method, a roller coating method, a wire bar coating method, a reverse coating method, a kiss coating method, a gravure coating method, a die coating method (U.S. Patent No. 2,681,294), etc. From the viewpoint of processability, the wire bar coating method, the reverse coating method, and the gravure coating method are more preferable. <Step 3> Step 3 is a step of laminating layer A onto the layer B surface of layer B / layer C / layer D created in Step 2. It is a common manufacturing method to laminate layer A onto the layer B surface of layer B / layer C / layer D by laminating. At the time of lamination, in order to improve the adhesiveness of layer B, it is preferable to set the temperature of the laminating roll at 110°C or higher and lower than 150°C.

[0052] [Applications of the laminate] Using the laminate of the present invention, shearing processes such as slitting and punching are carried out, and then the layer C / layer D laminate is peeled off, and a desired adherend can be laminated onto the layer B surface of layer A / layer B. For example, it is preferably used for electronic device parts with complex shapes and heater parts of household appliances, and can be used as an adhesive when laminating a metal laminated film with another base material, or laminated as a cover material for protecting the metal part of the metal laminated film. At the same time, when the film laminated with the adhesive is punched into a desired size and shape, the process can be kept clean without being contaminated.

[0053] Here, in the laminate of the present invention, among the two surfaces of this laminate, on surface A formed by layer A, a silicone resin is present, and further, the amount of the silicone resin present is 0.001 kcps or more and 0.10 kcps or less. In the present invention, the amount of the silicone resin present is synonymous with the silicone resin transfer amount. Since the silicone resin adheres to surface A and the amount of the silicone resin present is 0.001 kcps or more and 0.10 kcps or less, the water resistance of the laminate becomes further excellent.

[0054] Also, the amount of silicone resin transferred to layer A is such that, after being wound into a roll as an A / B / C / D layer laminate and left standing for 1000 hours in an atmosphere at a temperature of 25°C and a relative humidity of 50%, the C / D layer laminate is peeled off, and the peak intensity of the silicon element measured by wavelength-dispersive fluorescent X-ray analysis on the surface of layer A is 0.001 kcps or more and 0.10 kcps or less. That the peak intensity of the silicon element is 0.10 kcps or less, preferably 0.05 kcps or less, means that the transfer of the silicone resin in layer D to layers A and B is suppressed and the adhesiveness of layer B is maintained, and the adhesion between layer A and layer B can be maintained. Also, that the peak intensity of the silicon element is 0.01 kcps or more, preferably 0.05 kcps or more, means that the silicone resin in layer D has a thickness that can maintain sufficient mold release properties, and when the B / C / D layer laminate is pulled out from the roll, while suppressing the occurrence of peeling between layer B and layer C, separation can occur between layer B and layer D, so that the B / C / D layer laminate can be maintained, and the surface of layer B on the side opposite to the side facing layer C can be adhered to layer A, thereby constituting the A / B / C / D layer laminate. That is, as described above, the amount of silicone resin transferred from layer D to layer A is 0.001 kcps or more and 0.10 kpcs or less. Incidentally, the peak intensity of the silicon element measured by wavelength-dispersive fluorescent X-ray analysis on the surface of layer A as described above is synonymous with the amount of silicone resin adhered to surface A formed by layer A among the two surfaces of the laminate. For example, when the peak intensity of the silicon element measured by wavelength-dispersive fluorescent X-ray analysis on the surface of layer A is 0.01 kcps, the amount of silicone resin adhered to surface A formed by layer A among the two surfaces of the laminate is 0.01 kcps.

[0055] The influence of the transfer of the silicone resin to Layer B can be confirmed by peeling the Layer C / Layer D laminate from the Layer A / Layer B / Layer C / Layer D laminate and measuring the adhesion between Layer B and the adherend. The method for measuring the adhesion is not particularly limited. For example, after peeling the Layer C / Layer D laminate from the Layer A / Layer B / Layer C / Layer D laminate and laminating it on the Layer B side of the Layer A / Layer B laminate with the polycarbonate (PC) film "Iupilon" (registered trademark) (type NF2000) manufactured by Mitsubishi Gas Chemical Co., Inc., use the MCK Co., Ltd. MLP-600W type laminator to perform thermal bonding at a laminator temperature of 120°C, a line speed of 0.5 m / min, and a linear pressure of 2 kgf·cm to create a sample for measuring adhesion. After leaving the test piece for measuring the adhesion in a constant temperature chamber at 23°C for 1 hour, the adhesion can be measured using an autograph manufactured by Shimadzu Corporation under the conditions of a peeling angle of 180 degrees and a peeling speed of 50 mm / min between Layer A and the PC film. The adhesion is preferably 5.0 N / cm or more, and more preferably 7.0 N / cm or more. When the adhesion is 5.0 N / cm or more, it is possible to prevent Layer A and Layer B or Layer B and the adherend from peeling when performing shearing after laminating Layer B and the adherend, and also prevent Layer A and Layer B or Layer B and the adherend from peeling during the process conveyance. The adhesion obtained by this measurement is the "Adhesion 1 Normal Temperature (N / cm)" in Table 2. And for the laminate of the present invention, the value of the adhesion measured after laminating the adherend on the Layer B side of the laminate is 5.0 N / cm or more, and the adhesion referred to here is the "Adhesion 1 Normal Temperature (N / cm)".

[0056] Also, for the adhesion between Layer B and the adherend at high temperature, using the same sample as above and using the constant temperature bath attached to the autograph manufactured by Shimadzu Corporation used for the above adhesion measurement, the adhesion in a 120°C environment can be measured. The adhesion is preferably 5.0 N / cm or more, and more preferably 7.0 N / cm or more. When the adhesion is 5.0 N / cm or more, it is possible to prevent Layer A and Layer B or Layer B and the adherend from peeling when performing shearing after laminating Layer B and the adherend, and also prevent Layer A and Layer B or Layer B and the adherend from peeling during the process conveyance. The adhesion obtained by this measurement is the "Adhesion 2 High Temperature (N / cm)" in Table 2.

[0057] In order to maintain the followability to the adherend and not impair the design of the adherend, the laminate of the present invention preferably maintains adhesion at normal temperature and high temperature environments and is transparent. Also, it is preferable to maintain adhesion and transparency in the same manner even when wet with water.

[0058] The adhesion when wet with water is measured by cutting the laminate into an appropriate size, laminating it on the layer B surface onto a polycarbonate (PC) film manufactured by Mitsubishi Gas Chemical Company, and then performing thermal bonding using a laminator at a laminator temperature of 120°C, a line speed of 0.5 m / min, and a linear pressure of 2 kgf·cm to create a sample for measuring adhesion. The test piece for measuring adhesion is left in a constant temperature room at 23°C for 1 hour. Then, an aqueous solution in which 10 wt% of a quaternary ammonium salt, which is a surfactant, is dissolved is prepared. After heating the aqueous solution to 95°C, the test piece for measuring adhesion is immersed for 1 hour. Then, it is taken out from the aqueous solution, and the adhesive force is measured using an autograph manufactured by Shimadzu Corporation under the conditions of a peeling angle of 180 degrees and a peeling speed of 50 mm / min between layer A and the PC film. The adhesion obtained in this measurement is the "Adhesion 3 Water Resistance (N / cm)" in Table 2. And for the laminate of the present invention, an adherend is bonded to the layer B surface side of this laminate to obtain a laminate (i.e., a laminated structure) of the laminate and the adherend, and the value of the adhesion after immersing the laminated structure in an aqueous solution containing a surfactant at 95°C or higher is 5.0 N / cm or more. Here, the adhesion referred to is the "Adhesion 3 Water Resistance (N / cm)".

[0059] Also, the transparency of the laminate of the present invention can be determined by the total light transmittance of the laminate. The total light transmittance can be obtained by measuring according to JIS K7361-1:1997 using a haze meter (SH7000 manufactured by Nippon Denshoku Industries Co., Ltd.). And the obtained total light transmittance is the "Total Light Transmittance (%)" at "Normal Temperature 20°C" in Table 2. This total light transmittance is preferably 70% or more and 99% or less. By this total light transmittance being 70% or more, the design of the adherend can be maintained after bonding the adherend using the laminate of the present invention.

[0060] Furthermore, the transparency when wetted with water can be determined by the total light transmittance of the laminate. For the laminate of the present invention, the total light transmittance after immersing the laminate in an aqueous solution containing a surfactant at a temperature of 80°C or higher is 70% or more. Also, for the transparency when wetted with water, an aqueous solution in which 10 wt% of a quaternary ammonium salt, which is a surfactant, is dissolved is prepared. After heating the aqueous solution to 95°C, the laminate is immersed in the aqueous solution for 1 hour and then taken out from the aqueous solution, and the total light transmittance measured within 30 seconds is within the above range. The total light transmittance was measured using a haze meter (SH7000 manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7361-1:1997. The total light transmittance obtained by this measurement is the "total light transmittance (%)" at "high temperature 95°C" in Table 2. When this total light transmittance is 70% or more, even if the laminate of the present invention is wetted with water in a high-temperature environment after being bonded to an adherend, the laminate does not cause poor appearance and can maintain the designability of the adherend.

[0061] Also, for the laminate of the present invention, the total light transmittance of the laminate after immersing it in an aqueous solution at 95°C containing a surfactant is 70% or more. When the total light transmittance is 70% or more, the designability of the adherend can be maintained after bonding the adherend using the laminate of the present invention. From the above viewpoints, the above total light transmittance is preferably 75% or more, and more preferably 80% or more.

[0062] Also, in the laminate of the present invention, among the two surfaces of the laminate, the value of the adhesion between surface A and the adherend after bonding the adherend to surface B formed by layer B, the value of the adhesion between surface A and the adherend after immersing in an aqueous solution at 95°C containing a surfactant, and the value of the adhesion between surface A and the adherend in an environment at 100°C are all 5.0 N / cm or more. By these adhesion values all being 5.0 N / cm or more, the adhesion between the laminate of the present invention and the adherend can be maintained even at normal temperature or high temperature and when wetted with water. From the above viewpoints, these adhesion values are preferably all 5.0 N / cm or more, and more preferably all 7.0 N / cm or more.

[0063] In addition, in the laminate of the present invention, both the value of the adhesive strength measured after bonding an adherend to the layer B side thereof and the value of the adhesive strength after immersion in an aqueous solution containing a surfactant at 95°C or higher are 5.0 N / cm or more. The laminate of the present invention having such characteristics can maintain the adhesive strength without peeling when wetted with water in a high-temperature environment.

[0064] In addition, the laminate of the present invention is suitably used for a laminated structure. Here, the laminated structure is formed by laminating the laminate of the present invention and an adherend. Further, in this laminated structure, it is preferable that the adherend contains a polycarbonate resin. By containing the polycarbonate resin, the above-mentioned laminated structure becomes a laminated structure excellent in heat resistance and water resistance. And, the content of the polycarbonate resin in the adherend is preferably 50.0% by mass or more based on the whole adherend. When the content of the polycarbonate resin is 50.0% by mass or more, the occurrence of peeling between layer B and the adherend can be suppressed.

[0065] Also, since the bonding temperature is lower than the flow start temperature, shrinkage and melting of the adherend and the present laminate after bonding can be prevented, so that deformation of the adherend and the present laminate can be prevented. In order to confirm the above appearance defect, after laminating the layer A / layer B laminate and the adherend at a predetermined temperature and installing them on a flat surface, it can be confirmed by measuring the lifting height at the four corners thereof. The method for measuring warpage is not particularly limited. For example, the layer C / layer D laminate is peeled off from the layer A / layer B / layer C / layer D laminate, and after laminating it on the layer B surface of the layer A / layer B laminate with a polycarbonate (PC) film "Iupilon" (registered trademark) (type NF2000) manufactured by Mitsubishi Gas Chemical Company, a sample for warpage measurement is created by performing thermal adhesion processing using an MCK Corporation MLP-600W type laminator at a laminator temperature of 120°C, a line speed of 0.5 m / min, and a line pressure of 2 kgf·cm. The test piece for measuring the adhesive strength is installed on a flat surface, the lifting height at the four corners is measured, and the warpage value can be confirmed by obtaining the average value thereof. The warpage value is preferably 3 mm or less, and more preferably 2.5 mm or less. When the warpage value is 3 mm or less, a laminated structure with no abnormal appearance can be provided even after laminating layer A / layer B and the adherend.

Example

[0066] Examples are shown below to explain the present invention more specifically, but the present invention is not limited thereto.

[0067] (Measurement and Evaluation Method) (1) Adhesion 1 The laminate of the present invention was cut into a size of 100 mm × 100 mm, and after laminating it on the layer B surface of a polycarbonate (PC) film "Iupilon" (registered trademark) (type NF2000) manufactured by Mitsubishi Gas Chemical Co., Ltd. (hereinafter, this polycarbonate film "Iupilon" (registered trademark) (type NF2000) manufactured by Mitsubishi Gas Chemical Co., Ltd. may be referred to as a PC film), a MCK Co., Ltd. MLP-600W type laminator was used, and heat adhesion processing was performed at a laminator temperature of 120°C, a line speed of 0.5 m / min, and a linear pressure of 2 kgf·cm to create a sample for measuring adhesion. After leaving the test piece for measuring the adhesion in a constant temperature chamber at 23°C for 1 hour, the adhesive force was measured using an autograph manufactured by Shimadzu Corporation under the conditions of a peeling angle of 180 degrees between layer A and the PC film and a peeling speed of 50 mm / min.

[0068] (2) Adhesion 2 The laminate of the present invention was cut into a size of 100 mm × 100 mm, and after laminating it on the layer B surface of a polycarbonate (PC) film "Iupilon" (registered trademark) (type NF2000) manufactured by Mitsubishi Gas Chemical Co., Ltd., a MCK Co., Ltd. MLP-600W type laminator was used, and heat adhesion processing was performed at a laminator temperature of 120°C, a line speed of 0.5 m / min, and a linear pressure of 2 kgf·cm to create a sample for measuring adhesion. After leaving the test piece for measuring the adhesion in a constant temperature chamber at 23°C for 1 hour, it was set to 120°C after placing the sample in the constant temperature bath attached to the autograph manufactured by Shimadzu Corporation, left for 1 hour, and then the adhesive force was measured in the constant temperature bath under the conditions of a peeling angle of 180 degrees between layer A and the PC film and a peeling speed of 50 mm / min.

[0069] (3) Adhesion 3 The laminate of the present invention was cut into a size of 100 mm × 100 mm, and after laminating it on the surface B of layer of the laminate with a polycarbonate (PC) film “Iupilon” (registered trademark) (type NF2000) manufactured by Mitsubishi Gas Chemical Company, a MLP-600W laminator manufactured by MCK Co., Ltd. was used to perform thermal bonding at a laminator temperature of 120 °C, a line speed of 0.5 m / min, and a line pressure of 2 kgf·cm to prepare a sample for measuring the adhesive strength. The test piece for measuring the adhesive strength was left in a constant temperature room at 23 °C for 1 hour. Then, an aqueous solution in which 10 wt% of a quaternary ammonium salt, which is a surfactant, was dissolved was prepared. After heating the aqueous solution to 95 °C, the test piece for measuring the adhesive strength was immersed in the solution for 1 hour. Then, it was taken out from the aqueous solution, and the adhesive strength was measured with an autograph manufactured by Shimadzu Corporation under the conditions of a peeling angle of 180 degrees between layer A and the PC film and a peeling speed of 50 mm / min.

[0070] (4) Peel force The laminate of the present invention was cut into a size of 100 mm × 100 mm, and after leaving the test piece for measuring the adhesive strength in a constant temperature room at 23 °C for 1 hour, the adhesive strength between layer A and layer C was measured using an autograph manufactured by Shimadzu Corporation under the conditions of a peeling angle of 180 degrees and a peeling speed of 50 mm / min.

[0071] (5) Qualitative and quantitative evaluation of layer A, layer B, layer C, and the adherend [Qualitative and quantitative analysis of the resins contained in layer A, layer B, layer C, and the adherend] The qualitative analysis and quantitative analysis of the resins contained in layer A, layer B, layer C, and the adherend were carried out by the following procedure using LC / MS / MS. LC / MS / MS is a mass spectrometry method applicable to non-volatile compounds that are difficult to analyze by LC / MS (gas chromatograph mass spectrometer).

[0072] [Preparation of solutions of the resins contained in layer A, layer B, layer C, and the adherend] (a) Layer A or layer B or layer C or the adherend was shaved off from the laminate, and 0.04 g of each of them was weighed into a 25 mL volumetric flask. (b) Add 1 mL of HFIP (1,1,1,1,3,3,3 - hexafluoro - 2 - propanol) / chloroform (1 / 1) to the female flask and dissolve each layer. (c) After adding 2 mL of chloroform, gradually add acetonitrile to insolubilize the resin component. (d) After adding acetonitrile and making the volume up to 25 mL, dilute the prepared solution 100 - fold with acetonitrile. (e) Filter the 100 - fold diluted solution prepared in step (d) through a PTFE disk filter (0.45 μm), and use the filtrate obtained as the measurement solution.

[0073] <Qualitative analysis of the resins contained in layer A, layer B, layer C, and the adherend> (f) Subject the solution obtained in step (e) to LC / MS / MS, and confirm the retention time and peak area at which peaks derived from polyethylene terephthalate, polyester resin (excluding polyethylene terephthalate), or polycarbonate are detected from the chromatogram. (g) Perform MS analysis on the peaks derived from polycarbonate resin, polycaprolactone resin, and polyethylene terephthalate in layer A and the adherend (derived from polycarbonate resin), layer B (derived from polycarbonate resin and polycaprolactone resin), and layer C (derived from polyethylene terephthalate) to confirm the formula weights of the ions derived from polycarbonate resin, polycaprolactone resin, and polyethylene terephthalate.

[0074] <Preparation of standard solution and construction of calibration curve> (h) Weigh the qualified standard samples (0.01 g) derived from polycarbonate resin, polycaprolactone resin, and polyethylene terephthalate into a 10 - mL volumetric flask, dissolve them with methanol, and make the volume up to 10 mL to obtain the standard solution. (i) Aliquot the standard solution and dilute each with methanol to obtain a total of 4 standard solutions with arbitrary concentrations. (j) Subject the standard solutions obtained in step (i) to LC / MS / MS respectively, and confirm the peak areas of the chromatograms for each concentration. (k) Obtain the calibration curve by linearly approximating the relationship between the solution concentration and the peak area.

[0075] <Quantification of Resins Derived from Polycarbonate Resin, Polycaprolactone Resin, and Polyethylene Terephthalate Contained in Layer A, Layer B, Layer C, and the Substrate> (l) Substitute the peak area determined in procedure (f) into the calibration curve equation obtained in procedure (k), and calculate the concentrations of the polycarbonate resin-derived component in layer A and the substrate, the polycarbonate resin-derived and polycaprolactone resin-derived components in layer B, and the polyethylene terephthalate-derived component in layer C to determine the contents of the polycarbonate resin, polycaprolactone resin, and polyethylene terephthalate resin.

[0076] For procedures (a) to (g) and (k), (l), the experiments were carried out with n = 2, and the average values were taken as the results.

[0077] This analysis was performed using an LC system: LC-20A (manufactured by Shimadzu Corporation), an MS system: API4000 (manufactured by AB SCIEX Corporation), a column: Inertsil ODS-3 (2.1×150 mm, 5 μm) (manufactured by GL Sciences Inc.) under the conditions of a column temperature of 50°C, a flow rate of 0.25 mL / min, an injection volume of 1 μL, an ionization method: APCI (atmospheric pressure chemical ionization), a detection method: positive ion detection, and a measurement mode: SRM (selected reaction monitoring).

[0078] (6) Measurement of the Hydroxyl Group Concentration of Layer B Prepare the laminate of the present invention, remove and collect layer B from layer A, and then volatilize the organic solvent to prepare 1 g of the layer B composition. Then, dissolve 1 mg in chloroform, which is a solvent for NMR measurement, and use NMR "AVANCE NEO" manufactured by Hitachi High-Tech Corporation to measure and analyze the deviation of the excitation wavelength to measure the hydroxyl group content concentration.

[0079] (7) Flow Initiation Temperature of Layer B Prepare the laminate of the present invention. After removing and collecting layer B from layer A, volatilize the organic solvent to prepare the layer B composition. Then, using a differential scanning calorimeter "DSC-60 Plus" manufactured by Shimadzu Corporation, measure the heat quantity from room temperature to 400 °C at a heating rate of 10 °C / min, and measure the melting point from the peak. When multiple flow start temperatures could be confirmed, the lowest value was taken as the flow start temperature.

[0080] (8) Measurement of the thickness of layer B Prepare the laminate of the present invention, measure the thickness of the laminate (let the measurement result be a), then measure the thickness of layer A / layer B after removing layer C (let the measurement result be b), and calculate a - b to measure the thickness of layer C. Similarly, measure the thickness of layer A after removing layer B from layer A / layer B (let the measurement result be c), and calculate b - c to measure the thickness of layer B. Measure using a dial gauge (7-547 series, 7050) manufactured by Mitutoyo Corporation. Cut the sample into a 10 cm square, perform three measurements on one sample, and evaluate with the average value of the obtained values.

[0081] (9) Total light transmittance of the laminate (at room temperature and high temperature) Prepare the laminate of the present invention, cut it into 5 cm × 5 cm, and use a haze meter (SH7000 manufactured by Nippon Denshoku Industries Co., Ltd.) to measure the total light transmittance at room temperature according to JIS K7361-1:1997. Next, prepare an aqueous solution in which 10 wt% of a quaternary ammonium salt, which is a surfactant, is dissolved. After heating the aqueous solution to 95 °C, immerse the cut laminate in it for 1 hour. Take it out from the aqueous solution and use a haze meter (SH7000 manufactured by Nippon Denshoku Industries Co., Ltd.) within 30 seconds to measure the total light transmittance at high temperature according to JIS K7361-1:1997.

[0082] (10) Weight average molecular weight when layer B is analyzed by GPC Prepare the laminate of the present invention and collect 0.03 g of layer B from the laminate. Using a solution of about 15 g of about 0.2% by mass diluted with tetrahydrofuran, it was determined by conversion using polystyrene as a standard substance from the GPC chromatogram measured with a GPC measuring device (Nexra manufactured by Shimadzu Corporation, column GPC-801, column temperature 40 °C). In this specification, GPC means gel permeation chromatography. (11) Peak intensity of silicon element on the surface of layer A and layer D The laminate of the present invention was randomly extracted from layer A and the layer C / layer D laminate at three locations, and the laminate was cut out into a square shape of 50 mm × 50 mm. Using a wavelength-dispersive X-ray fluorescence analyzer (manufactured by Rigaku Corporation, product name "Mini-Z", output 200 W), the peak intensity of the silicon element on the obtained surfaces of layer A and layer D was measured, the average value of the three locations was calculated, and the content of the silicone resin on the surface of layer A and layer D was measured.

[0083] (12) Warpage value The laminate of the present invention was cut out into a size of 100 mm × 100 mm, and after laminating it on the layer B surface of this laminate with a polycarbonate film "Iupilon" (registered trademark) (type NF2000) manufactured by Mitsubishi Gas Chemical Company (hereinafter, this polycarbonate film "Iupilon" (registered trademark) (type NF2000) may be referred to as a PC film), using an MCK Corporation MLP-600W type laminator, heat adhesion processing was performed at a laminator temperature of 120 °C, a line speed of 0.5 m / min, and a line pressure of 2 kgf·cm to create a sample for measuring the warpage value. The test piece for measuring the adhesion was placed on a flat surface, the lifting height at the four corners was measured, and the average value thereof was obtained.

[0084] (Example 1) 〔Method for preparing each member〕 The method for preparing each member will be described below.

[0085] First, as a coating solution for forming Layer B, a polycarbonate resin A (hereinafter sometimes referred to as resin A) with a weight average molecular weight of 26,000 and a flow start temperature of 126°C, and a polycaprolactone resin B (hereinafter sometimes referred to as resin B) with a weight average molecular weight of 10,000 and a flow start temperature of 10°C were prepared. After mixing resin A / resin B at 90.0 / 10.0 (mass ratio), a coating solution H with a total content of resin A and resin B dissolved in toluene / methyl ethyl ketone (MEK) / methylene chloride = 4 / 1 / 1 (mass ratio) of 25% by mass was prepared.

[0086] Next, the laminate of Layer C / Layer D was produced by the following procedure. First, 90% by mass of "DOWSIL" (registered trademark) "LTC" (registered trademark) 750A (addition reaction type silicone resin) manufactured by Dow Corning Toray Co., Ltd. and 10% by mass of "DOWSIL" (registered trademark) SRX212 Catalyst manufactured by Dow Corning Toray Co., Ltd. were mixed to produce a Layer D coating composition. Next, this Layer D coating composition was dissolved in methyl ethyl ketone and mixed and dispersed using a homodisper (manufactured by Primix Corporation) to obtain a Layer D adjustment solution with a solid content of 3.0% by mass. Also, a polyethylene terephthalate (PET) film "Lumirror" (registered trademark) (type S10) (thickness 38 μm) manufactured by Toray Industries, Inc. was used as Layer C, and the Layer D adjustment solution was coated on one surface of the Layer C by the gravure coating method. After drying at 120°C, a laminate of Layer C / Layer D having a water-repellent layer with a thickness of 0.05 μm was obtained, and this was wound up in a roll shape.

[0087] Next, the coating solution H was coated on the Layer C side of the laminate of the laminate of Layer C / Layer D by the die coating method. After drying at 120°C, a laminate of Layer B / Layer C / Layer D having a Layer B with a thickness of 20 μm was obtained, and this was wound up in a roll shape.

[0088] Also, a polycarbonate (PC) film "Iupilon" (registered trademark) (type NF2000 thickness 125 μm) manufactured by Mitsubishi Gas Chemical Company was used as Layer A, and the laminate of Layer B / Layer C / Layer D was bonded to Layer A with the Layer B surface facing Layer A using a heat laminator at 120°C to produce laminate 1. The thickness of Layer B at that time was 16 μm.

[0089] The configuration of laminate 1 and the like are shown in Table 1, and the evaluation results of laminate 1 are shown in Table 2.

[0090] (Example 2) After mixing polycarbonate resin A and polycaprolactone resin B constituting layer B at a resin A / resin B ratio of 92.0 / 8.0 (mass ratio), a 25% by mass coating solution I dissolved in toluene / methyl ethyl ketone (MEK) / methylene chloride = 4 / 1 / 1 (mass ratio) was prepared, and then laminate 2 was prepared in the same manner as in Example 1.

[0091] (Example 3) After mixing polycarbonate resin A and polycaprolactone resin B constituting layer B at a resin A / resin B ratio of 87.0 / 13.0 (mass ratio), a 25% by mass coating solution J dissolved in toluene / methyl ethyl ketone (MEK) / methylene chloride = 4 / 1 / 1 (mass ratio) was prepared, and then laminate 3 was prepared in the same manner as in Example 1.

[0092] (Example 4) Laminate 4 was prepared in the same manner as in Example 1, except that the thickness of layer B was set to 8 μm.

[0093] (Comparative Example 1) After mixing polycarbonate resin A and polycaprolactone resin B constituting layer B at a resin A / resin B ratio of 75.0 / 25.0 (mass ratio), a 25% by mass coating solution K dissolved in toluene / methyl ethyl ketone (MEK) / methylene chloride = 4 / 1 / 1 (mass ratio) was prepared, and then laminate 5 was prepared in the same manner as in Example 1.

[0094] (Comparative Example 2) After mixing polycarbonate resin A and polycaprolactone resin B constituting layer B at a resin A / resin B ratio of 98.0 / 2.0 (mass ratio), a 25% by mass coating solution L dissolved in toluene / methyl ethyl ketone (MEK) / methylene chloride = 4 / 1 / 1 (mass ratio) was prepared, and then laminate 6 was prepared in the same manner as in Example 1.

[0095] (Comparative Example 3) Except for using a thermoplastic amorphous polyester resin C (Mitsubishi Chemical Corporation's "Polyester" (trademark registered) LP-011) with a flow start temperature of 65 °C, a weight average molecular weight of 16,000, and a flow start temperature of 4 °C instead of polycarbonate resin A (hereinafter sometimes referred to as resin C), a laminate 7 was produced in the same manner as in Example 1. In addition, the content of resin A in layer B of this laminate is 0.0% by mass, and the content ratio of resin A in the total content of resin A and resin B is 0.0% by mass.

[0096] (Comparative Example 4) Except for using resin C instead of polycaprolactone resin B, a laminate 8 was produced in the same manner as in Example 1. In addition, the content of resin B in layer B of this laminate is 0.0% by mass, and the content ratio of resin B in the total content of resin A and resin B is 0.0% by mass.

[0097] (Comparative Example 5) Except for preparing a 25% by mass coating solution M in which only polycarbonate resin A was dissolved in toluene / methyl ethyl ketone (MEK) / methylene chloride = 4 / 1 / 1 (mass ratio), a laminate 9 was produced in the same manner as in Example 1. In addition, the content of resin B in layer B of this laminate is 0.0% by mass, and the content ratio of resin B in the total content of resin A and resin B is 0.0% by mass.

[0098] (Comparative Example 6) Except for using a polyethylene terephthalate (PET) film "Lumirror" (registered trademark) (type T60, thickness 100 μm) manufactured by Toray Industries, Inc. for layer A instead of the polycarbonate (PC) film "Iupilon" (registered trademark) (type NF2000, thickness 125 μm) manufactured by Mitsubishi Gas Chemical Company, a laminate 10 was produced in the same manner as in Example 1.

[0099] Except for making the composition of each layer as described in Table 1, laminates were produced and evaluated in the same manner as in Example 1 for Examples 2 to 4 and Comparative Examples 1 to 6.

[0100] Table 1 shows the configurations and the like of the laminates of Examples 2 to 4 and Comparative Examples 1 to 6, and Table 2 shows the evaluation results of the laminates of Examples 2 to 4 and Comparative Examples 1 to 6.

[0101] All of the laminates of Examples 1 to 4 were excellent in adhesion 1, adhesion 2, adhesion 3, and total light transmittance. In contrast, it was confirmed that the laminate of Comparative Example 1 was inferior in adhesion (adhesion 2) under a high-temperature environment as compared with the laminate of Example 1. It was confirmed that all of adhesions 1 to 3 of the laminates of Comparative Examples 2, 5, and 6 were inferior as compared with the laminate of Example 1. It was confirmed that all of adhesions 1 to 3 of the laminate of Comparative Example 3 were inferior as compared with the laminate of Example 1. It was confirmed that the total light transmittance of the laminate of Comparative Example 4 was inferior as compared with the laminate of Example 1. In the laminates of Examples 1 to 4, all of adhesions 1 to 3 were 5.0 N / cm or more, the total light transmittance was 70% or more, and the warp value was 3.0 mm or less. These laminates were excellent in followability to adherends having a complicated shape and had no appearance abnormalities such as whitening or deformations such as melting.

[0102] [Table 1]

[0103] [Table 2] [Description of Signs]

[0104] 1: Layer A 2; Layer B 3: Layer C 4: Layer D

Claims

1. A laminate having at least layer A and layer B, wherein layer A is a film containing 90.0% by mass or more of a polycarbonate resin, layer B contains 80.0% by mass or more of a polycarbonate resin and 5.0% by mass or more and 15.0% by mass or less of a polycaprolactone resin, and the total light transmittance of the laminate before and after immersing the laminate in an aqueous solution at 95 °C containing a surfactant is 70% or more in both cases. A laminate characterized by this.

2. The polycarbonate resin contained in layer B contains a hydroxyl group in its molecular chain, layer B has two or more flow start temperatures, the flow start temperature of layer B is 100 °C or more and 140 °C or less, and the thickness of layer B is 5 μm or more and 40 μm. The laminate according to claim 1, characterized by this.

3. The flow start temperature of layer B is -5 °C or more and 25 °C or less on the low temperature side and 40 °C or more and 185 °C or less on the high temperature side, and the weight average molecular weight of layer B is 5000 or more and 30000 or less. The laminate according to claim 1 or 2, characterized by this.

4. On surface A formed by layer A among the two surfaces of the laminate, a silicone resin is present, and the amount of the silicone resin is 0.001 kcps or more and 0.10 kcps or less. The laminate according to any one of claims 1 to 3, characterized by this.

5. A laminate having at least layer A, layer B, layer C, and layer D in this order, wherein layer C contains 45.0% by mass or more of a polyethylene terephthalate resin, and layer D contains 90.0% by mass or more of a silicone resin. The laminate according to any one of claims 1 to 4, characterized by this.

6. The peel strength between layer B and layer C is 0.1 N / cm or more and 1.0 N / cm or less. The laminate according to any one of claims 1 to 5, characterized by this.

7. A laminated structure formed by laminating the laminate according to any one of claims 1 to 6 and an adherend, wherein the adherend contains a polycarbonate resin, and the content of the polycarbonate resin is 50.0% by mass or more based on the whole adherend. A laminated structure characterized by this.

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