Manufacturing method of laminate

Abstract

To provide a manufacturing method of a laminate capable of inhibiting a poor appearance even when adhered on glass having a complicated curved surface shape.SOLUTION: A manufacturing method of a laminate includes a lamination step of bonding a film on a substrate. The film has a structure in which two or more kinds of thermoplastic resin layers having different main constituents are regularly laminated by 51 to 2001 layers, inclusive. If a direction with a largest shrinkage factor S150(%) at 150°C is an X direction, a direction orthogonal to the X direction within a film surface is a Y direction, a shrinkage factor at 150°C in the X direction is S150X(%), a shrinkage factor at 150°C in the Y direction is S150Y(%), and S150X-S150Y is ΔS150, the film satisfies 0.7≤ΔS150≤10.0. A maximum curvature in the X direction of the film is 0.0001 to 0.1, inclusive, after the lamination step.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a laminate, a window, an information display device, and an oriented film. [Background technology]

[0002] Many products, such as mobile phones, personal computer housings, electrical appliances, furniture, buildings, and automobiles, require exterior design, and in recent years, the demand for design in these products has also increased. Known methods for imparting design to these products include, for example, painting or printing, attaching a colored film, or transferring the printed surface of a printed film onto a substrate. Furthermore, in addition to the demand for design, the demand for functionality in the exterior of these products is also increasing. For example, a known method involves applying a substrate to a product via a heating process that has been further endowed with properties such as heat ray reflectivity, heat ray absorption, gas barrier properties, adhesiveness, and electrical conductivity.

[0003] In recent years, in addition to design, heat-cutting glass that can suppress the inflow of heat from the outside in summer, especially from sunlight, has attracted attention in response to carbon dioxide emission regulations for environmental protection, and attempts have been made to use this in the windows of vehicles such as automobiles and trains, and buildings. Examples of how to obtain such heat-cutting glass include a method of attaching a substrate having a heat-cutting function to glass having a designed shape by heating, and a method of attaching a substrate having a heat-cutting function to glass and then heating it to give it a designed shape. Examples of substrates having a heat-cutting function include substrates having a layer containing a heat-absorbing material, substrates on which a metal film is formed by sputtering, and substrates on which multiple thermoplastic resin layers are laminated so as to cut heat rays.

[0004] Such heat-cutting glass is typically used in places where it is visible to the public, making its appearance important. Furthermore, increasing demands for design have led to increasingly complex glass shapes, such as those with multiple curved surfaces and larger curvatures. Therefore, the substrate, such as a film, that is applied must conform to this shape. For example, insufficient conformability can cause wrinkles when a substrate, such as a film, is applied to curved glass, or uneven distortions can occur in the film when the substrate, such as a film, is applied to glass and then shaped, resulting in a poor appearance. One known cause of these problems is an insufficient thermal shrinkage of the film under certain processing conditions, and methods for controlling this thermal shrinkage have been proposed (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2013 / 137288 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-81748 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the proposals in Patent Documents 1 and 2 are focused on increasing the thermal shrinkage rate of the film in all directions and suppressing unevenness (improving appearance) after laminating the film into glass. Therefore, sufficient consideration has not been given to suppressing the appearance of a bonded body obtained by the process of bonding the film or a substrate having a complex curved surface. Therefore, an object of the present invention is to provide a method for manufacturing a bonded body that can suppress poor appearance even when bonded to glass with a complex curved surface, and an oriented film that can be suitably used in the method for manufacturing the bonded body. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention comprises the following configurations. (1) A method for producing a laminated body, comprising a step of laminating a film on a substrate, wherein the film has a structure in which two or more types of thermoplastic resin layers having different main components are regularly laminated in 51 to 2001 layers, and the shrinkage ratio S of the film at 150°C is 150 The direction in which the largest shrinkage (%) is the X direction, the direction perpendicular to the X direction in the film plane is the Y direction, and the shrinkage rate in the X direction at 150°C is S 150X (%), and the shrinkage rate in the Y direction at 150°C is S 150Y (%), S 150X -S 150Y ΔS 150 When this is the case, 0.7≦ΔS 150 ≦10.0, and the maximum curvature of the film in the X direction after the bonding step is 0.0001 or more and 0.1 or less. (2) The method for producing a bonded body according to (1), wherein the angle between the X direction and the A direction is 0° or more and 30° or less, when the direction in which the curvature of the bonded body is maximum is defined as the A direction. (3) The film has a resistance of 0.1≦S 150X <2.5 and -0.6≦S 150Y <1.8. (4) The method for producing a bonded body according to (3), wherein the maximum curvature κA in the A direction is 0.0001 or more and 0.0050 or less. (5) The film has a S 150X ≦20.0 and 3.3≦S 150Y ≦19.7。 The method for producing a laminate according to any one of (1) to (4). (6) The method for producing a bonded body according to (5), wherein the maximum curvature κA in the A direction is greater than 0.0050 and not more than 0.1. (7) The method for producing a laminate according to any one of (1) to (6), wherein the film has a functional layer. (8) The method for producing a bonded body according to any one of (1) to (7), wherein when light having a wavelength of 300 to 2500 nm is incident on the film at an incident angle of 10°, the film has a continuous reflection band with a reflectance of 30% or more and 110% or less over a wavelength width of 20 nm or more and 1000 nm or less. (9) The method for producing a laminate according to any one of (1) to (8), wherein the film has an average reflectance of 0% or more and 15% or less at wavelengths of 400 to 700 nm and an average reflectance of 70% or more and 110% or less at wavelengths of 900 to 1200 nm. (10) The method for producing a laminate according to any one of (1) to (9), wherein, when the thickness of the film is D, and among the layer groups divided into two at a position of D / 2 from one surface, the layer group having the smaller average layer thickness of the layers constituting each layer group is called layer group A and the layer group having the thicker average layer thickness is called layer group B, the film is arranged in the attaching step so that the inner curved surface side is called layer group A. (11) A window comprising a bonded body obtained by the method for producing a bonded body according to any one of (1) to (10). (12) An information display device comprising a bonded body obtained by the method for producing a bonded body according to any one of (1) to (10). (13) A thermoplastic resin having a structure in which two or more thermoplastic resin layers with different main components are regularly laminated in 51 layers or more and 2001 layers or less, and a shrinkage rate S at 150 ° C. 150 The direction in which the largest shrinkage (%) is the X direction, the direction perpendicular to the X direction in the film plane is the Y direction, and the shrinkage rate in the X direction at 150°C is S 150X (%), and the shrinkage rate in the Y direction at 150°C is S 150Y (%), S 150X -S 150Y ΔS 150 When this is the case, 0.7≦ΔS 150 Oriented film that satisfies ≦10.0. (14) The oriented film according to (13), wherein each of the thermoplastic resin layers contains a polyester resin. (15) An oriented film according to (13) or (14), wherein the outermost layers on both sides of the film are the same layer, and the glass transition temperature of the thermoplastic resin that is the main component of the outermost layers is the highest among the main components of the thermoplastic resin layers that constitute the film. (16) The oriented film according to any one of (13) to (15), wherein the highest glass transition temperature of the oriented film is 90° C. or higher and 140° C. or lower. (17) The oriented film according to any one of (13) to (16), wherein, among the layers constituting the film other than the outermost layer, at least one layer has a difference between the average in-plane refractive index and the perpendicular refractive index of 0.01 or more and 0.30 or less. (18) The oriented film according to any one of (13) to (17), which has an in-plane retardation of 1,500 nm or more and 10,000 nm or less. (19) 0.1≦S 150X <2.5 and -0.6≦S 150Y The oriented film according to any one of claims 13 to 18, which satisfies <1.8. (20) 4.0≦S 150X ≦20.0 and 3.3≦S 150Y The oriented film according to any one of (13) to (19), which satisfies a σ ≦19.7. (21) An oriented film according to any one of (13) to (20), which has a reflection band with a continuous reflectance of 30% or more and 110% or less over a wavelength range of 20 nm or more and 1000 nm or less when light with a wavelength of 300 to 2500 nm is incident at an incident angle of 10°. (22) The oriented film according to any one of (13) to (21), having an average reflectance of 0% or more and 15% or less at wavelengths of 400 to 700 nm and an average reflectance of 70% or more and 110% or less at wavelengths of 900 to 1200 nm. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a method for manufacturing a bonded body that can suppress appearance defects even when a film is attached to glass with a complex curved surface shape, and an oriented film that can be suitably used in the method for manufacturing the bonded body. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below, but the present invention should not be construed as being limited to specific embodiments including the following examples, and various modifications that can achieve the object of the invention and do not deviate from the gist of the invention are included in the scope of the present invention.

[0010] The method for producing a laminate of the present invention is a method for producing a laminate, which includes a step of sticking a film onto a substrate, and the film has a structure in which two or more types of thermoplastic resin layers having different main components are regularly laminated in 51 layers or more and 2001 layers or less, and the shrinkage ratio S of the film at 150°C is 150 The direction in which the largest shrinkage (%) is the X direction, the direction perpendicular to the X direction in the film plane is the Y direction, and the shrinkage rate in the X direction at 150°C is S 150X (%), and the shrinkage rate in the Y direction at 150°C is S 150Y (%), S 150X -S 150Y ΔS 150 When this is the case, 0.7≦ΔS 150 ≦10.0, and the maximum curvature of the film in the X direction after the bonding step is 0.0001 or more and 0.1 or less.

[0011] <Film> The method for manufacturing a laminate of the present invention includes a step of laminating a film onto a substrate. In the method for manufacturing a laminate of the present invention, the film has a structure in which two or more thermoplastic resin layers having different main components are regularly laminated in a total of 51 to 2001 layers. Here, the term "thermoplastic resin layer" refers to a layer whose main component is a thermoplastic resin, i.e., a layer containing a total of more than 50% to 100% by mass of thermoplastic resin when the entire layer is taken as 100% by mass. Examples of minor components that are not the main component of the thermoplastic resin layer include inorganic components and low-molecular-weight organic components other than thermoplastic resins. Specific examples include light absorbers (ultraviolet absorbers, dyes, pigments, heat absorbers), antioxidants, light stabilizers, quenchers, heat stabilizers, weather stabilizers, organic lubricants, fillers, antistatic agents, nucleating agents, and flame retardants. These minor components can be freely added to each layer to the extent that the film's inherent properties and functions are not impaired.

[0012] Among these minor components, depending on the type of thermoplastic resin constituting each thermoplastic resin layer, it may absorb high-energy ultraviolet light and accelerate degradation, so it is preferable to include an ultraviolet absorber in order to suppress photodegradation by causing reaction competition. Furthermore, light absorbers such as ultraviolet absorbers may themselves be affected by degradation due to heat or oxygen, or photodegradation due to reaction with ultraviolet light or oxygen, during the resin extrusion process in film production. Therefore, antioxidants for the former and light stabilizers or quenchers for the latter can be added as additives to layers containing thermoplastic resins that may be subject to degradation, to the extent that the original physical properties and functions of the film are not impaired.

[0013] Representative thermoplastic resins used to form the thermoplastic resin layer in the film used in the manufacturing method of the laminate of the present invention are listed below, but are not limited to these. Thermoplastic resins that can be suitably used in the thermoplastic resin layer of the film include, for example, polyolefin resins such as polyethylene, polypropylene, poly(1-butene), poly(4-methylpentene), polyisobutylene, polyisoprene, polybutadiene, polyvinylcyclohexane, polystyrene, poly(α-methylstyrene), poly(p-methylstyrene), polynorbornene, and polycyclopentene, polyamide resins such as nylon 6, nylon 11, nylon 12, and nylon 66, and copolymers of vinyl monomers such as ethylene / propylene copolymers, ethylene / vinylcyclohexane copolymers, ethylene / vinylcyclohexene copolymers, ethylene / alkyl acrylate copolymers, ethylene / acrylic methacrylate copolymers, ethylene / norbornene copolymers, ethylene / vinyl acetate copolymers, propylene / butadiene copolymers, isobutylene / isoprene copolymers, and vinyl chloride / vinyl acetate copolymers. Examples of suitable polymers include resins, acrylic resins such as polyacrylate, polyisobutyl methacrylate, polymethacrylate, polymethyl methacrylate, polybutyl acrylate, polyacrylamide, and polyacrylonitrile; polyester resins such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene-2,6-naphthalate; biodegradable polymers such as polylactic acid and polybutyl succinate; and others, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, polyacetal, polyglycolic acid, polycarbonate, polyketone, polyethersulfone, polyether ether ketone, modified polyphenylene ether, polyphenylene sulfide, polyetherimide, polyimide, polysiloxane, tetrafluoroethylene resin, trifluoroethylene resin, trifluorochloroethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer, and polyvinylidene fluoride.

[0014] In each thermoplastic resin layer, these thermoplastic resins may be used alone, or two or more types of thermoplastic resins may be used as a blend or alloy. By implementing a blend or alloy, physical / chemical properties that cannot be obtained from a single type of thermoplastic resin can be obtained. In addition, when thermoplastic resin layers with significantly different skeletal structures are laminated, if a component that is common to the polymer skeletal structure contained in the thermoplastic resin layer on one side of adjacent thermoplastic resin layers can be imparted as a copolymer component to the thermoplastic resin layer on the opposite side, the interlayer adhesion at the interface can be improved.

[0015] In each thermoplastic resin layer constituting the film used in the method for producing a laminate of the present invention, from the viewpoint of rheological properties related to strength, heat resistance, transparency, and lamination, it is preferable that the thermoplastic resin serving as the main component is selected from polyolefin resin, polyester resin, acrylic resin, polycarbonate resin, and polyamide resin. Among these, from the viewpoint of the above, polyester resin is more preferably used, and it is more preferable that at least one of the thermoplastic resin layers is a polyester resin layer (a layer mainly composed of polyester resin). Even more preferable is a polyester resin obtained by polymerization of a monomer mainly composed of an aromatic dicarboxylic acid or an aliphatic dicarboxylic acid and a diol.

[0016] Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, and 4,4'-diphenylsulfonedicarboxylic acid. Examples of aliphatic dicarboxylic acids include adipic acid, suberic acid, sebacic acid, dimer acid, dodecanedioic acid, cyclohexanedicarboxylic acid, and their ester derivatives. Of these, terephthalic acid and 2,6-naphthalenedicarboxylic acid are preferred. These acid components may be used alone or in combination, and may also be partially copolymerized with hydroxy acids such as hydroxybenzoic acid.

[0017] Examples of diol components include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis(4-hydroxyethoxyphenyl)propane, isosorbate, and spiroglycol. Among these, ethylene glycol is preferred. These diol components may be used alone or in combination.

[0018] In each thermoplastic resin layer constituting the film used in the manufacturing method of the laminate of the present invention, it is particularly preferable to use a polyester resin selected from the above polyester resins, particularly polyethylene terephthalate and its copolymers, polyethylene naphthalate and its copolymers, polybutylene terephthalate and its copolymers, polybutylene naphthalate and its copolymers, and further polyhexamethylene terephthalate and its copolymers, and polyhexamethylene naphthalate and its copolymers, as the main component.

[0019] The film used in the method for producing a laminate of the present invention has a structure in which two or more thermoplastic resin layers having different main components are regularly laminated in a total of 51 to 2001 layers. This structure can impart functions to the film that cannot be achieved with a single layer. For example, it can impart light reflection, and this function improves with the number of layers based on the principle of interference reflection. From this perspective, the total number of thermoplastic resin layers is preferably 201 or more, more preferably 401 or more. Increasing the number of layers in the film enhances the interference reflection function derived from the lamination. For example, if the reflection band is near infrared or near infrared, it can improve heat ray blocking performance, etc. On the other hand, from the perspective of reducing the size of the lamination device, the upper limit of the number of thermoplastic resin layers is approximately 2001.

[0020] By using the film used in the method for producing a bonded body of the present invention as described above, it is easy to achieve the function of selectively reflecting light in a specific wavelength band by interference reflection, the function of reflecting light of a specific polarized light, etc., depending on the relationship between the difference in refractive index of each layer and the layer thickness. For example, if a film is used that has the function of reflecting infrared rays, by attaching this film to a substrate (e.g., glass), it can also be made into glass with high heat-shielding performance. Alternatively, if a film is used that has the function of reflecting light of a specific polarized light, by attaching this film to a substrate (e.g., glass), it can also be made into a glass member suitable for a display device that displays images with a specific polarized light.

[0021] In the film used in the method for producing the laminate of the present invention, the main component of the thermoplastic resin layer is "different" means that the components constituting the thermoplastic resin layer differ by more than 50% by mass. However, if it is difficult to specify this, it can be substituted by at least one of the following: (1) the glass transition temperature or melting point is different in differential scanning calorimetry (DSC), or (2) the contrast of the image after dyeing when the cross section is observed by transmission electron microscopy (TEM) is different.

[0022] In differential scanning calorimetry (DSC), the thermoplastic resin layers constituting the film can be determined to have "different" main components by showing different melting points and / or glass transition points. In the present invention, "different melting points" and "different glass transition temperatures" refer to melting points or glass transition points that differ by 0.1°C or more, preferably 2°C or more. On the other hand, there are cases where the thermoplastic resin layers do not show a glass transition point or melting point. If one thermoplastic resin layer shows a glass transition point or melting point and the other thermoplastic resin layer does not, this cannot be calculated as a temperature difference, but the main components of the thermoplastic resin layers are interpreted as being different. In the present invention, DSC measurements can be performed in the temperature range of 25°C to 300°C using the method of JIS-K-7122 (1987).

[0023] In the above-mentioned method, it is necessary to separate and analyze the corresponding thermoplastic resin layer from the film, but separation of the layers may be difficult depending on the layer structure of the film. Therefore, in the present invention, for simplicity, the layer interface can be recognized by contrast difference in the cross-sectional image observed by transmission electron microscope observation, and if it can be confirmed that the difference in the average brightness of two adjacent layers is greater than any of the standard deviations of brightness within each of the adjacent thermoplastic resin layers by the method described in the section on layer interface (contrast difference) in the measurement method described below, it can be determined that the contrast of the dyed image is different and that the main components of the adjacent thermoplastic resin layers are "different."

[0024] This contrast difference arises due to differences in electron beam scattering, crystal diffraction, etc. between thermoplastic resin layers. Therefore, if the main components of the thermoplastic resin layers differ according to the above-mentioned criteria, the crystallinity and electron density state will differ depending on the type of thermoplastic resin constituting each thermoplastic resin layer and the copolymerization amount of the combined thermoplastic resin, and the electron dyeing state will also differ. In other words, if the film has thermoplastic resin layers with different main components, each thermoplastic resin layer can be visually recognized as a layer structure with a contrast difference in a cross-sectional image of the film. The presence or absence of a contrast difference can be evaluated using the method described below.

[0025] In the film used in the method for producing a laminate of the present invention, from the viewpoint of interlayer adhesion and high precision of the laminate structure, it is preferable that the regularly laminated thermoplastic resin layers each contain, as a main component, a thermoplastic resin having the same basic skeleton. The basic skeleton is the repeating unit most abundant in the molecular chain, such as ethylene terephthalate units in the case of polyethylene terephthalate and ethylene units in the case of polyethylene.

[0026] When the film used in the method for producing a laminate of the present invention has a structure in which two types of thermoplastic resin layers (referred to as A1 layer and B1 layer) having different main components are alternately laminated, a preferred combination of thermoplastic resins used as the main components of A1 layer and B1 layer is a combination in which the thermoplastic resin that is the main component of A1 layer and the thermoplastic resin that is the main component of B1 layer have the same basic skeleton. When the thermoplastic resins that are the main components of each layer have the same basic skeleton, the lamination precision is high and further, interlayer delamination at the lamination interface is less likely to occur.

[0027] To impart different properties to thermoplastic resins having the same basic skeleton, it is preferable to use a copolymer as the main component of one layer, or to use a copolymer as the main component of both layers, but with different types or amounts of copolymerized units. An example of the former is a configuration in which one layer's main component is homopolyethylene terephthalate, while the other layer's main component is a polyester resin composed of ethylene terephthalate units and repeating units containing other ester bonds. The proportion of the other repeating units (sometimes referred to as the copolymerization amount) is preferably 5 mol% or more to achieve different properties, while less than 50 mol% is preferred to achieve excellent interlayer adhesion and excellent thickness accuracy and uniformity due to minimal differences in thermal flow properties. A ratio of 10 mol% to 45 mol% is even more preferred. An example of the latter is a configuration in which each layer's main component is a polyester resin composed of ethylene terephthalate units and repeating units containing other ester bonds, but with different copolymerization amounts. It is also desirable that the A1 layer and the B1 layer each be a blend or alloy of multiple types of thermoplastic resins, which can provide performance that cannot be achieved with a single type of thermoplastic resin.

[0028] In addition, a preferred combination of thermoplastic resins used as the main components of the A1 layer and the B1 layer of the film used in the method for producing a laminate of the present invention is one in which the difference in glass transition temperature between the thermoplastic resins is 20°C or less. A difference in glass transition temperature of 20°C or less improves thickness uniformity during film formation of the laminated film, resulting in more uniform reflection characteristics. Furthermore, the occurrence of overstretching during film formation can be reduced.

[0029] When the film of the present invention has a layer configuration in which A1 layers and B1 layers are alternately laminated and the A1 layers are disposed as the outermost layers on both sides, if the difference in glass transition temperature between the thermoplastic resin that is the main component of A1 layer (thermoplastic resin A1) and the thermoplastic resin that is the main component of B1 layer (thermoplastic resin B1) is greater than 5° C., it is more preferable that the glass transition temperature of thermoplastic resin A1 is higher than the glass transition temperature of thermoplastic resin B1. The relatively high glass transition temperature of A1, which is the outermost layer, reduces adhesion to rolls or clips during longitudinal stretching or transverse stretching, and suppresses deterioration of appearance quality.

[0030] In the film used in the method for producing a laminate of the present invention, the difference in the in-plane average refractive index between the A1 layer and the B1 layer is preferably 0.03 or more. It is more preferably 0.05 or more, and even more preferably 0.10 or more. When the difference in the in-plane average refractive index between the A1 layer and the B1 layer is 0.03 or more, sufficient reflectance is obtained, resulting in improved heat ray blocking performance, for example. One method for achieving the difference in the in-plane average refractive index between the A1 layer and the B1 layer within the above range is to use an embodiment in which one of the thermoplastic resins A1 and B1 is crystalline and the other is amorphous. Crystallinity here refers to a melting enthalpy of 10 J / g or more in differential scanning calorimetry (DSC). Similarly, amorphousness refers to a melting enthalpy of less than 10 J / g.

[0031] When the main components are such a combination of thermoplastic resins, it is possible to easily provide an in-plane average refractive index difference during the stretching and heat treatment steps in the production of the film. Furthermore, when such a combination of resins is used, orientation can be alleviated by heat treatment at a temperature that is much higher than the glass transition temperature of the amorphous polyester and equal to or lower than the melting point of the crystalline polyester.

[0032] In the case of amorphous thermoplastic resins, the refractive index usually does not change during the stretching and heat treatment processes in film production, so the refractive index can also be measured by vacuum drying the thermoplastic resin and then pressing it into a sheet, as needed. The in-plane average refractive index refers to the average value of the refractive index in the X and Y directions (described below) (details of how to specify each direction and how to measure the refractive index will be described later).

[0033] As an example of a resin combination that satisfies the above conditions, in the film of the present invention, it is preferable that the A1 layer be primarily composed of polyethylene terephthalate or polyethylene naphthalate, and the B1 layer be primarily composed of a polyester having the same basic skeleton as the primary component of the A1 layer and containing spiroglycol. The spiroglycol-containing polyester refers to a copolyester copolymerized with spiroglycol, or a polyester blended with a copolyester copolymerized with spiroglycol. Spiroglycol-containing polyesters are preferred because they have a small difference in glass transition temperature from polyethylene terephthalate or polyethylene naphthalate, making them less susceptible to overstretching during molding and less susceptible to delamination. From the above perspectives, a more preferable embodiment is one in which the A1 layer is primarily composed of polyethylene terephthalate or polyethylene naphthalate, and the B1 layer is primarily composed of a polyester having the same basic skeleton as the primary component of the A1 layer and containing spiroglycol and cyclohexanedicarboxylic acid. When the B1 layer is primarily composed of a polyester resin containing spiroglycol and cyclohexanedicarboxylic acid, the difference in in-plane refractive index between the B1 layer and polyethylene terephthalate or polyethylene naphthalate is large, making it easier to achieve high reflectance by alternately laminating the A1 and B1 layers. Furthermore, this type of polyester has a small difference in glass transition temperature between the B1 layer and polyethylene terephthalate or polyethylene naphthalate, and exhibits excellent adhesive properties. Therefore, the film is less likely to be overstretched during molding, and delamination between the A1 and B1 layers can be reduced.

[0034] The copolymerization amount of the polyester containing spiro glycol and cyclohexanedicarboxylic acid is preferably 5 mol% to 30 mol% for spiro glycol and 5 mol% to 30 mol% for cyclohexanedicarboxylic acid. Furthermore, the copolymerization amount of the polyester containing spiro glycol is preferably 5 mol% or more and less than 50 mol%. When using a polyester containing spiro glycol and cyclohexanedicarboxylic acid, it is also preferable to blend a small amount of polyethylene terephthalate. By adopting such an embodiment, when the film is heated to form a laminate having a curvature, denaturation of the polyester resin due to heating is suppressed, and poor appearance of the resulting laminate is easily suppressed. From this perspective, the blend ratio of the polyester resin containing spiro glycol and cyclohexanedicarboxylic acid to polyethylene terephthalate is preferably 95:5 to 70:30.

[0035] Other preferred embodiments include those in which the A1 layer contains a small amount of the thermoplastic resin that is the main component of the B1 layer, those in which the B1 layer contains a small amount of the thermoplastic resin that is the main component of the A1 layer, and those that combine both of the above. By blending small amounts of the thermoplastic resins that are the main components of either the A1 layer or the B1 layer, or both, in this manner, high-precision lamination, improved interlayer adhesion, and improved stretchability during film formation can be achieved. In such embodiments, the blending ratio is preferably in the range of 5% to 30% by mass, with the entire layer being taken as 100% by mass.

[0036] Furthermore, the film used in the method for producing a laminate of the present invention preferably has a regular arrangement consisting of the A2 layer, the B2 layer, and the C2 layer, where the three thermoplastic resin layers have different main components and are designated as the A2 layer, the B2 layer, and the C2 layer, respectively. Here, the term "regular arrangement" refers to a laminate structure in which three thermoplastic resin layers with "different" main components are laminated in a regular arrangement, as defined above. In this case, the three thermoplastic resin layers with different main components may each be formed from a thermoplastic resin with a different skeletal structure, or two thermoplastic resins with different skeletal structures may be used, with the three thermoplastic resin layers being designed to have different blend ratios or copolymerization amounts. For convenience, hereafter in this specification, the thermoplastic resin layers with different main components will be defined alphabetically as the A2 layer, the B2 layer, and the C2 layer in the order in which they first appear when viewed from the outermost surface of the film, and the thermoplastic resins that are the main components of each thermoplastic resin layer will be defined as the thermoplastic resin A2, the thermoplastic resin B2, and the thermoplastic resin C2.

[0037] If the different thermoplastic resin layers are defined as layer A2, layer B2, and layer C2 in the order of arrangement from the outermost surface of the laminate film, examples of the regular arrangement possessed by the film used in the first invention include (ABC)x, (ABCB)x, (ABAC)x, (ABCAB)x, (ABCAC)x, (ABABC)x, and (ABCBCB)x (the numbers in parentheses represent the regular arrangement, and x is a natural number indicating the number of repetitions. A, B, and C represent layer A2, layer B2, and layer C2, respectively. Note that similar notations may be used hereinafter in describing the regular arrangement consisting of layer A2, layer B2, and layer C2). In particular, to ensure that a film made of thermoplastic resins with different physical / chemical properties, such as skeletal structure and viscoelasticity / viscosity characteristics, maintains its laminate structure over a long period of time without interfacial delamination and loss of essential functions, it is necessary to consider a combination of thermoplastic resin layers that are compatible (e.g., miscibility, surface free energy) with the adjacent thermoplastic resin layers that form the interface between the different thermoplastic resin layers in the film.

[0038] Therefore, to avoid complicating the resin design of the entire film, it is preferable to limit the number of different interface combinations formed between adjacent thermoplastic resin layers. Specifically, the interfaces formed by three different types of thermoplastic resin layers include three types: the A2-B2 interface, the B2-C2 interface, and the C2-A2 interface. Among the regular arrangements, (ABCB)x and (ABCBCB)x are preferred because they have only two types: the A2-B2 interface and the B2-C2 interface. In such an embodiment, the resin design only needs to be such that delamination between the A2 layer and the B2 layer, and between the B2 layer and the C2 layer, is unlikely to occur, and the combination of the A2 layer and the C2 layer does not need to be given much consideration.

[0039] In the method for producing a laminate of the present invention, the film used in the method has a shrinkage rate S 150 The direction with the largest shrinkage (%) is the X direction, the direction perpendicular to the X direction in the film plane is the Y direction, and the shrinkage rate in the X direction at 150°C is S 150X (%), and the shrinkage rate in the Y direction at 150°C is S 150Y (%), S 150X -S 150Y ΔS 150 When this is the case, 0.7≦ΔS 150 ≦10.0. Here, the X direction is defined as the S direction among any one direction in a plane parallel to the film surface and each direction rotated from that direction up to 180° in a plane parallel to the film surface at 5° intervals. 150 The shrinkage rate can be determined from a thermal shrinkage curve measured by thermomechanical analysis under conditions of a temperature of 25°C to 200°C and a heating rate of 10°C / min, where a positive value indicates shrinkage and a negative value indicates expansion, based on the length at 25°C (the specific measurement method will be described later).

[0040] By adopting such an embodiment, when a film is applied to a curved surface of a substrate, the film shrinks upon heating, allowing it to conform to the curved surface, resulting in a bonded product without poor appearance. If conformance to a curved surface depends on the shrinkage rate, a method of controlling the shrinkage rate of the film in the same way in all directions is also possible. However, when substrates have complex curved shapes due to improved design, if the thermal shrinkage rate is the same in all directions, poor appearance will only be suppressed in specific areas. For example, in a substrate with a single curved surface, where the curvature differs between the left-right and up-down directions, problems such as poor appearance can be suppressed in the direction with the greater curvature but not in the direction with the smaller curvature may occur (details of the substrate shape will be discussed later). Alternatively, in the case of a substrate with multiple curved surfaces, poor appearance may be suppressed in one curved surface but not in the other curved surfaces. Furthermore, controlling the shrinkage rate of the film in the same way in all directions imposes many restrictions on the film's manufacturing conditions and the type of thermoplastic resin that constitutes it, often resulting in a deterioration of film properties other than its ability to conform to a curved surface. Therefore, after extensive research, the inventors discovered that by imparting anisotropy to the thermal shrinkage rate of the film, it is possible to maintain film properties other than the ability to conform to curved shapes, while allowing the film to conform well to substrates with complex curved shapes, thereby suppressing poor appearance.

[0041] The film used in the method for producing the laminate of the present invention has a ΔS 150 A method for imparting the property of ≦10.0 will be explained below with an example. For example, a method can be used in which an unoriented sheet formed by a melt extrusion process and a casting process is stretched in the longitudinal or transverse direction to form a uniaxially oriented film. In the case of a uniaxially oriented film, the stretching direction is the shrinkage ratio S 150 The direction in which the film thickness is greatest (%), i.e., the X direction. Here, the longitudinal direction refers to the running direction of the sheet or film (the winding direction of the film in the case of a film roll), and the width direction refers to the direction perpendicular to the longitudinal direction within the film plane.

[0042] As another example, a method can be used in which a non-oriented sheet formed by a melt extrusion process and a casting process is stretched in the longitudinal direction and the transverse direction to form a biaxially oriented film. In this case, stretching can be carried out in two directions sequentially or simultaneously. The biaxially oriented film can have a stretching ratio of 0.7≦ΔS 150 To obtain a shrinkage ratio of ≦10.0, methods include: providing a difference in the stretching ratio between the longitudinal direction and the width direction; performing a relaxation treatment in the longitudinal direction between stretching in the longitudinal direction and stretching in the width direction; performing a relaxation treatment in the width direction after biaxial stretching; adjusting the heat treatment temperature and the conditions for the relaxation treatment in the width direction; and performing further stretching in the width direction after biaxial stretching (additional stretching in the width direction). In the method of providing a difference in the stretching ratio between the longitudinal direction and the width direction, the direction with the higher stretching ratio is higher; in the method of performing relaxation treatment in the longitudinal direction, the longitudinal direction is higher; and in the method of performing relaxation treatment in the width direction and additional stretching in the width direction, the shrinkage ratio S 150 (%) is the direction in which the difference is largest, that is, the X direction. Note that these methods may be combined as appropriate.

[0043] The film used in the method for producing a laminate of the present invention is preferably a biaxially oriented film from the viewpoints of toughness and handleability. Furthermore, from the viewpoint of maintaining film properties other than conformity to a curved surface shape, a method of performing width direction relaxation treatment and width direction additional stretching is more preferred.

[0044] The film used in the method for producing a bonded body of the present invention preferably has, on at least one surface, a reflection band in which the reflectance is continuous over a wavelength range of 20 nm to 1000 nm when light having a wavelength of 300 to 2500 nm is incident at an incident angle of 10°. Details of the measurement of each optical property will be described later, but the incident angle refers to the angle with the normal to the film surface. "On at least one surface" means that the requirements are met when the reflectance is measured by irradiating light onto at least one surface. Hereinafter, "on at least one surface" in the measurement of optical properties will be interpreted in the same way.

[0045] When the film used in the method for producing a laminate of the present invention has the above-described properties, for example, when it has a reflection band in the wavelength range of 400 to 700 nm, it can be colored by visible light, thereby providing decorative properties (design), and when it has a reflection band in the wavelength range of 850 nm or more, it can provide heat-shielding properties. From the viewpoint of enhancing each property, the wavelength width is more preferably 100 nm or more, and even more preferably 300 nm or more. From the above viewpoint, the wider the wavelength width of the reflection band, the more preferable it is, but from the viewpoint of feasibility, the upper limit is 1000 nm. Here, the maximum value of reflectance in the reflection band exceeds 100% because the reflectance here is the relative reflectance based on a white aluminum oxide plate (details of the measurement method will be described later). Note that, as a means for obtaining a film having at least one reflection band with a reflectance of 30% or more continuous over a wavelength width of 20 nm or more, the number of thermoplastic resin layers in the film and the layer thickness can be adjusted. More specifically, the width of the reflection band can be widened by increasing the number of layers.

[0046] The film used in the method for producing a bonded body of the present invention preferably has an average reflectance of 0% to 15% at wavelengths of 400 to 700 nm and an average reflectance of 70% to 110% at wavelengths of 900 to 1200 nm. By adopting such an embodiment, when applied to, for example, the windows of a building or an automobile, it is possible to improve the heat shielding properties of the interior (interior) of the vehicle by reflecting infrared rays while maintaining aesthetics and the view and visibility from the interior (interior). From the viewpoint of heat shielding properties, the average reflectance at wavelengths of 900 to 1200 nm is more preferably 80% or more. Meanwhile, the upper limit of the average reflectance is set to 105% from the viewpoint of feasibility.

[0047] One method for obtaining such a film is to set the sum of the optical thicknesses of adjacent layers to 400 to 700 nm for the majority of the thermoplastic resin layers constituting the film. The optical thickness here refers to the product of the layer thickness of each layer and the refractive index of the resin constituting the layer. The sum of the optical thicknesses of adjacent layers determines the wavelength at which interference reflection occurs in the film. Interference reflection from a film in which the sum of the optical thicknesses of adjacent layers is 400 to 700 nm typically occurs in the wavelength range of approximately 800 to 1400 nm, making it easy to achieve an average reflectance of 70% to 110% in the wavelength range of 900 to 1200 nm. Furthermore, the magnitude of reflectance increases with the number of layers and the difference in the in-plane average refractive index of adjacent layers. In a film in which the sum of the optical thicknesses of adjacent layers for the majority of the layers is 400 to 700 nm, it becomes easy to efficiently improve the average reflectance in the wavelength range of 850 to 1200 nm.

[0048] Another example of a film having an average reflectance of 70% or more in the wavelength range of 900 to 1200 nm is one in which the layer thickness distribution of two types of thermoplastic resin layers (A1 layer, B1 layer) having different main components is such that the optical thicknesses of the adjacent A1 layer and B1 layer simultaneously satisfy the following formulas 1 and 2. Equation 1:λ=2(n α d α +n β d β ) Formula 2:n α d α =n β d β where λ is the reflected wavelength, n α is the in-plane refractive index of the A1 layer, d α is the thickness of the A1 layer, n β is the in-plane refractive index of the B1 layer, d βis the thickness of the B1 layer. Having a layer thickness distribution that simultaneously satisfies both Equation 1 and Equation 2 can eliminate even-order reflections. This allows for a high average reflectance in the 900-1200 nm wavelength range while a low average reflectance in the visible light range of 400-700 nm, resulting in a transparent film with excellent heat-ray blocking properties. Generally, the refractive index of a film formed from a thermoplastic resin after stretching is approximately 1.4-1.9. Therefore, by setting the thickness ratio of the adjacent A1 layer to the B1 layer (thickness of the A1 layer / thickness of the B1 layer) to 0.7 or more and 1.4 or less, a film with suppressed even-order reflections can be obtained. Therefore, it is preferable that the thickness ratio of the adjacent A1 layer to the B1 layer (thickness of the A1 layer / thickness of the B1 layer) be 0.7 or more and 1.4 or less. It is more preferable that the thickness ratio be 0.8 or more and 1.2 or less.

[0049] Another example of a layer thickness distribution is the 711711 configuration (U.S. Pat. No. 5,360,659). The 711711 configuration is a stacked structure in which six layers, each consisting of an A1 layer and a B1 layer stacked in the ABABAB order, form one repeating unit, with the optical thickness ratio within the unit being 711711 (A represents the A1 layer, and B represents the B1 layer). A layer thickness distribution with the 711711 configuration can eliminate high-order reflections. This allows for a high average reflectance in the wavelength range of 900 to 1200 nm while a low average reflectance in the wavelength range of 400 to 700 nm, resulting in a transparent film with excellent thermal energy blocking performance. It is also preferable to use a layer thickness distribution that simultaneously satisfies both Equations 1 and 2 for reflections in the wavelength range of 900 to 1200 nm, and thus for reflections in the wavelength range of 1200 to 1400 nm, with the 711711 configuration. By using such a layer thickness configuration, light can be reflected efficiently with a small number of layers.

[0050] One embodiment of the film used in the method for producing a bonded body of the present invention is one in which the refractive index of at least one surface of the film is 1.68 or more and 1.80 or less. By making the refractive index 1.68 or more, it becomes easy to increase the reflectance in the reflection band. If the refractive index is higher than 1.80, the difference in chemical structure becomes large, which deteriorates the lamination property of the thermoplastic resin A1 and the thermoplastic resin B1, and the film may become cloudy or peeling at the interface between the A1 layer and the B1 layer may become noticeable.

[0051] An example of a method for achieving a refractive index of 1.68 to 1.80 on at least one surface of the film is a method in which the main dicarboxylic acid unit of the thermoplastic resin A1 is a naphthalenedicarboxylic acid unit. This method allows for an in-plane refractive index difference between the A1 layer and the B1 layer, making it easier to obtain a laminated polyester film with superior reflective performance. Furthermore, in order to increase the in-plane refractive index difference between the A1 layer and the B1 layer, it is also preferable that the thermoplastic resin B1 be an amorphous resin. To incorporate naphthalenedicarboxylic acid into the dicarboxylic acid constituents of the thermoplastic resin A1 of the film, a method can be used in which naphthalenedicarboxylic acid is included in the dicarboxylic acid constituents of the raw material polyester resin that constitutes the thermoplastic resin A1.

[0052] The layer thickness distribution is preferably a layer thickness distribution in which the layer thickness increases or decreases from one side of the film surface to the opposite side, a layer thickness distribution in which the layer thickness increases from one side of the film surface toward the center of the film and then decreases, a layer thickness distribution in which the layer thickness decreases from one side of the film surface toward the center of the film and then increases, etc. The layer thickness distribution preferably changes in a continuous manner, such as linearly, geometrically, or by difference progression, or in a manner in which about 10 to 50 layers have approximately the same layer thickness and the layer thickness changes in a stepwise manner.

[0053] In the film used in the method for producing a laminate of the present invention, a layer having a thickness of 3 μm or more can be preferably provided as a protective layer on both surface layers. The thickness of the protective layer is preferably 5 μm or more, more preferably 10 μm or more. By providing a protective layer or increasing the thickness of the protective layer, the appearance of the obtained film can be easily improved (reducing flow marks) and ripples in the transmittance and reflectance spectra can be suppressed.

[0054] The film used in the method for producing a laminate of the present invention preferably has the same outermost layer on both sides, and the glass transition temperature of the thermoplastic resin that is the main component of the outermost layer is the highest among the main components of the thermoplastic resin layers that make up the film. By making the outermost layers on both sides of the film the same layer, it becomes easier to produce the film. Furthermore, by making the outermost layers on both sides of the film from a thermoplastic resin that has the highest glass transition temperature among the main components of the thermoplastic resin layers that make up the film, it is possible to easily suppress poor appearance when applied to a substrate having a curved surface.

[0055] The highest glass transition temperature among the main components of the thermoplastic resin layer constituting the film used in the manufacturing method of the laminate of the present invention is preferably 90°C or higher and 140°C or lower. The bonding process involves heating, and the heating temperature is generally a high temperature of 100°C or higher. In such a bonding process, if the glass transition temperature of the thermoplastic resin layer is lower than 90°C, the heat during the bonding process may cause the layer to soften, resulting in deformation and poor appearance, or film properties other than shape conformity may be deteriorated. Furthermore, if the glass transition temperature is higher than 140°C, depending on the shape to be bonded, the film may not shrink sufficiently even upon heating, making it unable to conform to the shape. By using a thermoplastic resin layer of the above-mentioned embodiment, it is possible to maintain the properties of the film, suppress poor appearance due to heat during the bonding process, and impart excellent shape conformity to even complex shapes.

[0056] Of the layers other than the outermost layer constituting the film used in the method for producing a bonded body of the present invention, it is preferable that the difference between the in-plane average refractive index and the in-plane normal refractive index in at least one layer is 0.01 or more and 0.30 or less. A difference of 0.01 or more between the in-plane average refractive index and the in-plane normal refractive index indicates in-plane orientation, which means that the heat resistance of the layer is high. If the difference between the in-plane average refractive index and the in-plane normal refractive index is less than 0.01, the heat resistance is low, which may cause the film to soften due to heat during the bonding process and deform, resulting in poor appearance. Furthermore, if the difference between the in-plane average refractive index and the in-plane normal refractive index is greater than 0.03, the difference in the in-plane average refractive index with the other layers constituting the film becomes small, which may deteriorate film properties other than shape conformity, or the heat resistance may be so high that the film does not shrink sufficiently even when heated, making it unable to conform to the shape depending on the shape to be bonded. By keeping the difference between the in-plane average refractive index and the in-plane normal refractive index within the above-mentioned range, it is possible to maintain the film's properties while suppressing poor appearance due to heat during the bonding process and imparting excellent shape conformity to complex shapes.

[0057] There is no particular restriction on the method for achieving a difference between the in-plane average refractive index and the perpendicular refractive index of the film of 0.01 to 0.30, but an example is a method in which a small amount of crystalline polyethylene terephthalate is blended with a thermoplastic resin whose difference between the in-plane average refractive index and the perpendicular refractive index is less than 0.01.

[0058] The film used in the method for producing a laminate of the present invention preferably has an in-plane retardation of 1500 nm or more and 10,000 nm or less. If the in-plane retardation is less than 1500 nm, the film may appear discolored when used as a window film, especially when wearing polarized sunglasses. If the in-plane retardation is greater than 10,000 nm, the film may be oriented too strongly in one direction, resulting in impaired handleability. By setting the in-plane retardation within the above range, both appearance and handleability can be achieved when used as a window film. A retardation of 1500 nm or more and 3,000 nm or less is particularly preferred. In this case, not only is the appearance and handleability particularly excellent, but high transparency can also be easily maintained. The retardation can be achieved by adjusting the stretching conditions when stretching the film.

[0059] The thickness of the film used in the method for producing a bonded body of the present invention is preferably 20 μm to 300 μm. If the film thickness is thinner than 20 μm, the film may be difficult to produce and provide, while if the film thickness is thicker than 300 μm, the film may become stiff and difficult to handle. By setting the film thickness within the above range, not only is the film easy to produce, but the film's handleability is improved, making the application process involving heating easier to carry out.

[0060] Next, a preferred manufacturing method for obtaining a biaxially oriented film suitable for use in the manufacturing method of the laminate of the present invention will be explained below using the example of a method of sequentially biaxially stretching two types of thermoplastic resins, but the present invention should not be construed as being limited to such an example.

[0061] First, the thermoplastic resins constituting each thermoplastic resin layer of the film are prepared in the form of pellets or the like. Here, when forming an alloy of an amorphous polyester and a crystalline polyester, it is preferable to prepare pellets kneaded in advance using a twin-screw extruder or the like. The dispersion state of the crystalline polyester can be controlled by selecting the screw of the twin-screw extruder, controlling the discharge rate, screw rotation speed, kneading temperature, etc., and can also be controlled by adding a compatibilizer such as a polyester elastomer. By preparing pellets kneaded in advance using a twin-screw extruder or the like in this way, it becomes possible to control the dispersion state and domain size of the crystalline polyester in the amorphous polyester.

[0062] The pellets are then dried in hot air or under vacuum as needed and then fed into separate extruders. The pellets are melted in each extruder by heating above their melting point or to 250-330°C. The resin extrusion rate is uniformed using a gear pump or the like, and foreign matter and denatured resin are removed from the molten resin through a filter or the like. The resin is then formed into a sheet using a die and discharged. The sheet is then cooled and solidified on a cooling body such as a casting drum to obtain an unoriented sheet. In this process, it is preferable to use a wire-, tape-, needle-, or knife-shaped electrode to electrostatically adhere the molten sheet to a cooling body such as a casting drum, thereby rapidly solidifying the molten sheet. Other preferable methods for adhering the molten sheet to a cooling body include blowing air from a slit-, spot-, or planar-shaped device to adhere the molten sheet to the cooling body, and using nip rolls to adhere the molten sheet to the cooling body. The surface temperature of the casting drum is preferably 20-50°C.

[0063] Furthermore, when producing a sheet consisting of multiple thermoplastic resin layers, the multiple resins are fed through different channels using the same number of extruders as the number of resin types and then fed into a multi-layer lamination device. For two types of thermoplastic resin layers, two extruders are used. While a multi-manifold die, feed block, static mixer, etc. can be used as the multi-layer lamination device, it is preferable to use a feed block containing at least two separate members with multiple fine slits, particularly for efficiently obtaining a desirable layer structure in the film used in the first invention. The use of such a feed block prevents the device from becoming excessively large, suppresses the generation of foreign matter due to thermal degradation, and enables high-precision lamination even when the number of layers is extremely large. Furthermore, the lamination accuracy in the width direction is significantly improved compared to conventional technology, and it is also easy to form an arbitrary layer thickness structure. This device allows the thickness of each layer to be adjusted by the shape (length and width) of the slits, making it easy to achieve an arbitrary layer thickness. The molten multi-layer laminate formed in this manner with the desired layer structure is then guided into a die to obtain an unoriented sheet as described above.

[0064] The resulting unoriented sheet is then biaxially stretched in the longitudinal and width directions. Here, stretching in the longitudinal direction refers to uniaxial stretching to impart longitudinal molecular orientation to the sheet, and is typically performed by varying the peripheral speed of the longitudinal stretching machine rolls. This stretching can be performed in a single stage or in multiple stages using multiple pairs of rolls. The stretching ratio varies depending on the type of resin, but is typically preferably 2 to 10 times. For example, when using polyethylene terephthalate or polyethylene naphthalate, which are thermoplastic resins that form the crystalline thermoplastic resin layer preferably used in the film of the first invention, a ratio of 2 to 7 times is particularly preferred. If the stretching ratio is excessively large during the longitudinal stretching step, strong orientation can occur, resulting in neckdown in the width direction, making it impossible to obtain a sufficient sheet width, and can also result in significant thickness unevenness in the longitudinal and / or width directions after width direction stretching. The stretching temperature is preferably set within a range from the glass transition temperature of the thermoplastic resin layer with the highest glass transition temperature among the thermoplastic resin layers constituting the sheet to the glass transition temperature + 100°C.

[0065] The uniaxially stretched sheet is then stretched in the width direction. Prior to this, if necessary, surface treatments such as corona treatment, flame treatment, and plasma treatment may be performed, followed by the application of an adhesive layer by in-line coating to provide properties such as slipperiness, adhesion, and antistatic properties. In the in-line coating process, the adhesive layer may be applied to one side of the film, or to both sides of the sheet simultaneously or sequentially. Stretching in the width direction refers to stretching to impart widthwise orientation to the sheet. This is typically performed by using a tenter to hold both widthwise edges of the sheet with clips and conveying the sheet while increasing the distance between the opposing clips. The stretching ratio varies depending on the type of resin, but is typically preferably 2 to 10 times. For example, when using polyethylene terephthalate or polyethylene naphthalate, which are thermoplastic resins that form the crystalline thermoplastic resin layer preferably used in the film of the present invention, a stretching ratio of 2 to 7 times is particularly preferred. The stretching temperature is preferably between the glass transition temperature of the resin with the highest glass transition temperature among the resins constituting the sheet and glass transition temperature + 120°C.

[0066] The biaxially stretched film is then heat-treated in a tenter at a temperature equal to or higher than the stretching temperature but lower than the melting point of the thermoplastic resin layer with the highest melting point among the thermoplastic resin layers constituting the film, preferably at a temperature equal to or higher than the stretching temperature but lower than the melting point of the thermoplastic resin layer with the highest melting point among the thermoplastic resin layers constituting the film -30°C. The film is then uniformly and slowly cooled, then cooled to room temperature, and wound up. If necessary, a relaxation treatment may be performed in the longitudinal and / or transverse directions between the heat treatment and the slowly cooling to impart thermal dimensional stability.

[0067] Here, the film used in the method for producing the laminate of the present invention is selected from the group consisting of a film having a surface roughness of 0.7≦ΔS 150 In a manufacturing method for achieving a β-value of ≦10.0, the heat treatment temperature after width direction stretching is preferably below the melting point of at least one thermoplastic resin and above the melting point of at least one of the remaining thermoplastic resins. In this case, one thermoplastic resin maintains a high orientation while the orientation of the other thermoplastic resin is relaxed, making it easy to achieve a refractive index difference between these resins. Furthermore, while maintaining the orientation, it is possible to impart higher heat shrinkage behavior only in the width direction. For example, in a film having two thermoplastic resin layers (A1 layer, B1 layer) with different main components, where the A1 layer is made of a crystalline polyester (crystalline polyester A1) and the B1 layer is made of an amorphous polyester and a crystalline polyester (crystalline polyester B1) different from the crystalline polyester A1, the heat treatment temperature is preferably below the melting points of the crystalline polyester A1 and the crystalline polyester B1. In this case, the orientation of the crystalline polyester A1 and the orientation of the crystalline polyester B1 are maintained, resulting in more favorable heat shrinkage behavior.

[0068] It is also preferable to perform a relaxation treatment in the width direction between the heat treatment and the gradual cooling. However, since the relaxation treatment is usually performed to suppress heat shrinkage behavior (reduce the shrinkage rate), it is also preferable not to perform the relaxation treatment in the width direction for the film used in the first invention, and the preferred degree of relaxation treatment is a ratio of the relaxation treatment to the film width before the relaxation treatment of 0% to 5%. Although it depends on the type of thermoplastic resin used, for example, in the case of polyethylene terephthalate and an amorphous polyester that is completely melted in the heat treatment step, the ratio of the relaxation treatment to the film width before the relaxation treatment is in the range of about 0% to 5%, and 0.7≦ΔS 150 A film satisfying a viscosity of ≦10.0 can be obtained.

[0069] It is also preferable to perform additional stretching in the width direction between the heat treatment and the annealing. By performing additional stretching, the orientation in the width direction alone is further strengthened, making it easier to increase the shrinkage rate in the width direction alone, and the shrinkage rate in the width direction alone is 0.7≦ΔS 150 A film satisfying the above condition can be easily obtained. The stretching ratio is preferably in the range of about 2% to 5% of the width of the film before stretching.

[0070] The film used in the method for producing a bonded body of the present invention may further have a functional layer. Here, the functional layer refers to a layer having a function not present in the film used in the first invention, such as an easy-adhesion layer, a hard coat layer, an abrasion-resistant layer, a scratch-resistant layer, an anti-reflection layer, a color correction layer, an ultraviolet absorbing layer, a heat absorbing layer, a weather-resistant layer, a printing layer, a gas barrier layer, an adhesive layer, a conductive layer, or a protective layer. The functional layer may have only one of the above-mentioned functions, or may have multiple functions. The functional layer may consist of one layer or two or more layers. The same functional layer may be present on both sides of the film, or functional layers with different functions may be present on each side.

[0071] The functional layer of the film used in the method for producing a bonded body of the present invention preferably has adhesive properties. Here, adhesiveness refers to the ability to adhere to other materials. The method for imparting adhesive properties to the functional layer is not particularly limited, but examples include applying adhesives to the functional layer, such as vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, ethylene-vinyl acetate copolymers, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, polyvinyl ether, nitrile rubbers, styrene-butadiene rubbers, natural rubbers, chloroprene rubbers, polyamides, epoxy resins, polyurethanes, acrylic resins, cellulose, polyvinyl chloride, polyacrylic esters, and polyisobutylene. These components may be used alone or in combination. If necessary, adhesive adjusters, plasticizers, heat stabilizers, antioxidants, UV absorbers, antistatic agents, lubricants, colorants, crosslinkers, and the like may be added. These adhesives may be in liquid, gel, block, powder, sheet, or other forms before processing.

[0072] Examples of methods for providing an adhesive functional layer to the film used in the method for producing a bonded body of the present invention include a method of applying the above-mentioned liquid or gel adhesive to the film, and a method of transferring a sheet-like adhesive to the film.

[0073] The functional layer of the film used in the method for producing a laminate of the present invention preferably has heat ray absorption properties. Heat ray absorption properties refer to the ability to absorb light rays mainly in the near-infrared to far-infrared region with wavelengths exceeding 700 nm. By having such a functional layer, the heat shielding performance can be further improved.

[0074] The method for imparting heat ray absorption to the functional layer is not particularly limited, but examples include an embodiment in which the functional layer contains a heat ray absorbing material. Examples of applicable heat ray absorbing materials include lanthanum-based particles, antimony-based particles, indium-based particles, tin-based particles, and tungsten-based particles. These are preferred from the viewpoint of ensuring transparency, even though they have low light absorption in the visible light region. In general, lanthanum-based particles and tungsten-based particles have high absorption performance, particularly in the wavelength range of 700 to 1500 nm, while antimony-based particles, indium-based particles, and tin-based particles have high absorption performance, particularly in the wavelength region of 1500 nm or longer. These heat ray absorbing materials may be used alone or in combination, and are preferably used in combination with the aforementioned adhesive.

[0075] Resins suitable for the heat ray absorbing functional layer are preferably selected from acrylic resins, urethane resins, polyester resins, silanols, etc., and the type is not particularly limited, and these can be used alone or in combination. Taking acrylic resins as an example, it is preferable to use acrylic resins obtained using, as monomers, for example, methacrylic acid, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, 4-hydroxybutyl methacrylate glycidyl ether, phenylglycidyl acrylate, epoxy acrylate, epoxy methacrylate, dipentaerythritol hexaacrylate, or the like (monomers may be used alone or in combination).

[0076] Furthermore, the resin forming the heat-absorbing functional layer and the mixture serving as its precursor are preferably cured by using an initiator, curing agent, or catalyst, since this accelerates curing. The initiator is preferably one that can initiate or accelerate polymerization, condensation, or crosslinking reactions through anionic, cationic, or radical reactions. Various initiators, curing agents, and catalysts can be used. The initiator, curing agent, and catalyst may be used alone, or multiple initiators, curing agents, and catalysts may be used simultaneously. Furthermore, an acidic catalyst, a thermal polymerization initiator, or a photopolymerization initiator may be used in combination, with photopolymerization initiators being preferred.

[0077] Examples of acidic catalysts include aqueous hydrochloric acid, formic acid, and acetic acid. Examples of thermal polymerization initiators include peroxides and azo compounds. Examples of photopolymerization initiators include alkylphenone compounds, sulfur-containing compounds, acylphosphine oxide compounds, and amine compounds. As the photopolymerization initiator, alkylphenone compounds are preferred in terms of curability. Specific examples of alkylphenone compounds include 1-hydroxycyclohexylphenylketone, 2.2-dimethoxy-1.2-diphenylethan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-phenyl)-1-butane, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-(4-phenyl)-1-butane. , 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butane, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butane, 1-cyclohexyl-phenyl ketone, 2-methyl-1-phenylpropan-1-one, 1-[4-(2-ethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, and the like.

[0078] Methods for providing a heat ray absorbing functional layer to the film used in the manufacturing method of the laminate of the present invention include a method of applying a mixture that forms a heat ray absorbing functional layer to the film, and a method of transferring a heat ray absorbing sheet formed on another film to the film.

[0079] The functional layer of the film used in the method for producing a laminate of the present invention preferably has weather resistance. Weather resistance means showing durability against natural environments such as ultraviolet rays, wind and rain, temperature changes, etc. By having such a functional layer, deterioration of the film can be suppressed when the film is applied to the outside of a window of a building or a car, for example.

[0080] There are no particular limitations on the method for imparting weather resistance to the functional layer, but an example is an embodiment in which an ultraviolet absorber is included. Examples of ultraviolet absorbers include benzophenone-based compounds, triazine-based compounds, and benzotriazole-based compounds, and it is preferable to contain at least one selected from these. Specific examples of benzophenone-based compounds include salicylate-based ultraviolet absorbers such as phenyl salicylate, 4-t-butylphenyl salicylate, 2,4-di-t-butylphenyl-3,5'-di-t-butyl-4'-hydroxylbenzoate, and 4-t-octylphenyl salicylate; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-n-octoxybenzophenone, and 2-hydroxy-4-n-dodecyloxybenzophenone. benzophenone, 2-hydroxy-4-benzyloxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-(2-methacryloyloxyethoxy)benzophenone, and the like.

[0081] Examples of triazine compounds include 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine, and 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-1,3,5-triazine. Examples of hydroxyphenyltriazine-based ultraviolet absorbers include hydroxyphenyltriazine-based ultraviolet absorbers such as (4-phenylphenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-acetoxyethoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, and 2,2'-dihydroxy-4,4'-dimethoxy-5,5'-disulfobenzophenone disodium salt.

[0082] Benzotriazole compounds include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2'-hydroxy-3',5'-bis(α,α-dimethylbenzyl)phenyl]benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, and 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole. , 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-amyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2N-benzotriazole-2-yl)phenol], and the like.

[0083] These may be used alone or in combination of two or more. Among them, hydroxyphenyltriazine-based ultraviolet absorbers are preferred because the ultraviolet absorber itself is stable against ultraviolet light and heat and has excellent absorption ability.

[0084] Examples of commercially available ultraviolet absorbers include Tinuvin 326, 384-2, PS, 900, 400, 460, 477, and 479 (manufactured by BASF), Adekastab LA-29, 31, 36, 46, and 1413 (manufactured by ADEKA Corporation), and Hostavin ARO8, 3041, and VSU (manufactured by Clariant).

[0085] Resins suitable for the weather-resistant functional layer are the same as those suitable for the heat-absorbing functional layer described above, and the method for forming the functional layer is also the same.

[0086] <Substrate> The method for producing a bonded body of the present invention includes a bonding step of bonding a film onto a substrate. In the present invention, the substrate refers to a plate-like body to which a film can be bonded. The substrate must have a curved surface so that the maximum curvature of the film in the X direction after the bonding step (described later) falls within a desired range. The material of the substrate is not particularly limited, but examples thereof include glass, resin, metal, and ceramic. Examples of resins include acrylic resins such as polycarbonate, cyclic polyolefin, polyarylate, polyethylene terephthalate, and polymethyl methacrylate, ABS, and triacetyl cellulose. These components may be used alone or in combination. The glass is not particularly limited, and commonly used transparent glass can be used. Specific examples include clear glass, float glass, polished glass, figured glass, wired glass, lined glass, infrared-absorbing glass, infrared-reflecting glass, and green glass. The substrate is preferably transparent, and its thickness is preferably 0.5 mm to 5.0 mm.

[0087] In the lamination step of laminating a film onto a substrate, when the film is to be formed into a laminate having a curved surface, the most preferred method is to laminate a film having an adhesive functional layer on at least one surface onto a curved substrate while shaping the film at a temperature of 150° C. or higher. From this viewpoint, the substrate is preferably glass.

[0088] The substrate used in the method for producing a bonded body of the present invention may have a single curved shape curved only in one of the left-right or up-down directions, or a compound curved shape curved in both the left-right and up-down directions. The curvatures in the left-right and up-down directions may be the same or different. The substrate may have one or more curved surfaces. The substrate of the present invention has a curved surface, and all points on this curved surface have a maximum curvature in the direction of one tangent vector (first tangent vector) of two tangent vectors that are tangent to the curved surface and perpendicular to each other, and a minimum curvature in the direction of the other tangent vector (second tangent vector).

[0089] The relationship between each vector and curvature described above will be explained in detail for one curved surface. Let S1 be one surface of the substrate, a point on S1 be point P, and let Sn be the plane containing the unit normal vector n and unit tangent vector x at point P. S1 cut by Sn describes a curve c. Furthermore, let κ be the curvature of curve c at point P. The unit tangent vector x1 at which curvature κ is at its maximum value κ1 and the unit tangent vector x2 at which curvature κ is at its minimum value κ2 are mutually orthogonal (according to Euler's theorem; the theorem of identification, where θ is the angle between x and x1, κ = κ1 cos2θ + κ2 sin2θ). Note that the maximum value κ1 of curvature κ is the maximum curvature, and the minimum value κ2 is the minimum curvature. Furthermore, among all points on the substrate, the point where the maximum curvature κ1 is the largest is defined as point Pmax, the maximum curvature at point Pmax is defined as κA, the direction of the unit tangent vector that results in κA is defined as direction A, the minimum curvature is defined as κB, and the direction of the unit tangent vector that results in κB is defined as direction B. As mentioned above, direction A and direction B are orthogonal to each other.

[0090] When the substrate has a single curved shape, it has a point where the minimum curvature κ2 is 0. When the substrate has a compound curved shape, with a curved surface having non-uniform curvatures in the left-right and up-down directions, it has a point where the maximum curvature κ1 and the minimum curvature κ2 are different. When the substrate has a compound curved shape, with a curved surface having identical curvatures in the left-right and up-down directions, it has a point where the maximum curvature κ1 and the minimum curvature κ2 are substantially the same. The substrate used in the first invention preferably has a point where the maximum curvature κ1 and the minimum curvature κ2 are different, and more preferably has a point where the minimum curvature κ2 is 0.

[0091] <Attachment process> The method for producing a bonded body of the present invention includes a bonding step of bonding a film onto a substrate, and the maximum curvature of the film in the X direction after the bonding step is 0.0001 to 0.1. Regardless of the shape of the substrate, by making the film have a curved shape at least in the X direction, i.e., in the maximum shrinkage direction, it becomes easy to impart excellent shape conformability even to complex shapes.

[0092] In the method for producing a laminate of the present invention, the step of attaching a film to a substrate is not particularly limited as long as the substrate and film can be attached, but examples thereof include a step of applying a pressure-sensitive adhesive or adhesive to a substrate by coating or laminating the substrate and then attaching the film, and a step of applying a pressure-sensitive adhesive or adhesive to a film by coating or laminating the film and then laminating the film to the substrate. Furthermore, as a method for forming a curved shape, the above-mentioned laminating step may be performed on a substrate having a curve, or a curved surface may be formed after the above-mentioned laminating step. Furthermore, a method involving heating is more preferable when imparting a curved shape to a film.

[0093] As an example of the application process, a procedure will be described in which a curved glass substrate is used and a film having an adhesive layer on one side is applied to the curved inner surface of the glass, but the application process is not limited to this. First, an application liquid is prepared by dissolving a surfactant in water. The water can be distilled water, ion-exchanged water, or tap water. Examples of surfactants that can be used include ester-type surfactants such as glycerin fatty acid esters, sorbitan fatty acid esters, and sucrose fatty acid esters; ether-type surfactants such as alkyl polyethylene glycols and polyoxyethylene alkylphenyl ethers; and nonionic surfactants such as alkyl glycosides. The concentration of the surfactant in the application liquid can be, for example, from about 0.01% by mass to about 5% by mass. By setting the surfactant content within this range, the wettability of the application liquid to the glass surface, evaporation time, and the like can be easily adjusted.

[0094] Next, spray the application liquid onto the curved outer surface of the glass (the side opposite the surface to which the film will be applied), and attach the adhesive-free side of a film cut to a sufficient size to the curved outer surface of the glass. At this time, the film adheres to the curved outer surface of the glass due to the surface tension of the application liquid. Adjust the position and size of the film as needed. Use a heat gun or similar device to apply hot air to areas of the film that are not in contact with the glass, especially curved sections of the glass, to shrink those areas and bring them into contact with the glass surface. Spray the application liquid again between the film and the glass, and use a squeegee to adhere the film to the curved outer surface of the glass. If there are any areas where the film is not sufficiently adhered, use a heat gun or similar device to apply hot air again to shrink the film until it is firmly adhered to the curved outer surface of the glass. Once the entire film is in contact with the curved outer surface of the glass, mark the position on the film as appropriate and then remove it from the glass.

[0095] The application liquid is then sprayed onto the curved inner surface of the glass (the surface to which the film will be applied), and also onto the surface of the adhesive layer of the film. The film is then applied to the curved inner surface of the glass. A squeegee is used to scrape out the application liquid between the film and the curved inner surface of the glass toward the outer periphery of the film, while pressing the film against the glass, adhering the film to the curved inner surface of the glass.

[0096] In the present invention, the maximum curvature of the film in the X direction after the lamination step is 0.0001 to 0.1 means that the film is laminated such that the X direction of the film, i.e., the maximum shrinkage direction, is the direction in which the film has at least a curved surface. To achieve this, for example, a method can be used in which the film is laminated to a substrate having a direction in which the maximum curvature is 0.0001 to 0.1, such that the X direction overlaps with the direction.

[0097] Furthermore, in the method for producing a bonded body of the present invention, when the direction in which the curvature of the bonded body is maximum is defined as the A direction, the angle between the X direction and the A direction is preferably 0° or more and 30° or less. Here, the angle between the X direction and the A direction is the angle when viewed from the direction of the unit normal vector at point Pmax where the curvature of the bonded body is maximum. A 0° angle between the X direction and the A direction means that the direction of maximum shrinkage of the film is aligned with the direction of maximum curvature of the substrate. If the angle between the X direction and the A direction exceeds 30°, the direction in which the shrinkage rate of the film is small becomes the direction in which the curvature of the substrate is maximum, resulting in insufficient conformance to the curved surface shape, which may result in poor appearance of the resulting bonded body. By setting the angle between the X direction and the A direction within the above range, the film can efficiently conform to various shapes, such as substrates with different curvatures in the left-right and up-down directions or substrates with multiple curves, thereby suppressing poor appearance of the entire substrate.

[0098] The film used in the method for producing the laminate of the present invention has a surface roughness of 0.1≦S 150X <2.5 and -0.6≦S 150Y It is also preferable that S<1.8. 150X is less than 0.1 and S 150Y If the shrinkage ratio is less than −0.6, the film does not shrink in any direction, and therefore, depending on the size of the substrate, it may be difficult to prevent defects in appearance when the substrate has a curved surface.

[0099] The substrate used in the manufacturing method of the bonded body of the present invention preferably has a maximum curvature κA in the A direction of 0.0001 or more and 0.0050 or less. When the substrate has such an embodiment, the degree of the curved surface is gentle. In addition, the reciprocal of the curvature is the radius of curvature, and the radius of curvature of the maximum curvature κA of the bonded body is R A , the radius of curvature of the orthogonal minimum curvature κB is R B When κA is 0.0001 or more and 0.0050 or less, R A is 500 to 10,000 mm, and R A and R B It is preferable that the difference between R is 4500 mm or more. B The optimum range is about 5000 to 12000 mm.A and R B The larger the difference, i.e., the greater the anisotropy of the shape, the more efficiently the effect of the difference in shrinkage rate of the film is exerted, and the more preferable it is because the appearance defect is suppressed. For the same reason, it is also preferable that the substrate has κB of 0 (i.e., a single-bend shape). The κA of the bonded body can be adjusted by the κA of the substrate.

[0100] In the method for producing a laminate of the present invention, the film has a thickness of 0.1≦S 150X <2.5 and -0.6≦S 150Y When <1.8 is satisfied, it is more preferable that the bonded body has a maximum curvature κA in the A direction of 0.0001 or more and 0.0050 or less, since this reduces poor appearance due to insufficient or excessive shrinkage of the film.

[0101] The film used in the method for producing the laminate of the present invention has a surface roughness of 4.0≦S 150X ≦20.0 and 3.3≦S 150Y ≦19.7 may be satisfied. 150X is less than 4.0 and S 150Y If S is less than 3.3, the film will not shrink in any direction, making it difficult to prevent defects in appearance on a curved substrate. 150X is 20.0 or less and S 150Y When the tensile strength is 19.7 or less, sufficient heat treatment during film production ensures toughness, resulting in good handling properties and reducing poor appearance due to wrinkles caused by excessive shrinkage.

[0102] The bonded body obtained by the manufacturing method of the bonded body of the present invention preferably has a maximum curvature κA in the A direction of more than 0.0050 and not more than 0.1. When the substrate has such an embodiment, it has a relatively steeply curved surface. In addition, the curvature radius of the maximum curvature κA of the bonded body is R A , the radius of curvature of the orthogonal minimum curvature κB is R B When κA is greater than 0.0050 and less than 0.1, R A is 10 to 200 mm, and R A and R BIt is preferable that the difference between R is 4500 mm or more. B The optimum range is about 5000 to 12000 mm. A and R B The larger the difference, i.e., the greater the anisotropy of the shape, the more efficiently the effect of the difference in shrinkage rate of the film is exerted, and the more preferable it is because the appearance defect is suppressed. For the same reason, it is also preferable that the substrate has κB of 0 (i.e., a single-bend shape). The κA of the bonded body can be adjusted by the κA of the substrate.

[0103] In the method for producing a laminate of the present invention, the film has a thickness of 4.0≦S 150X ≦20.0 and 3.3≦S 150Y ≦19.7 and the substrate has a maximum curvature κA in the A direction that is greater than 0.0050 and is 0.1, this is more preferable because it can prevent insufficient shrinkage of the film relative to the shape, resulting in poor appearance, and conversely, excessive shrinkage, resulting in wrinkles in the film, resulting in poor appearance.

[0104] In the present invention, when the thickness of the film is D and the layer groups divided into two at a position D / 2 from one surface are designated layer group A as the layer group with the smallest average layer thickness and layer group B as the layer group with the thickest average layer thickness, it is preferable to arrange the film in the attachment step so that the inner curved surface side is layer group A. Here, the average layer thickness refers to the average value of the layer thicknesses of each layer in the layer group, and the layer group refers to a group of layers that are part of a structure in which thermoplastic resin layers are regularly laminated.

[0105] The film used in the method for producing a laminate of the present invention preferably has a layer thickness distribution in which the layer thickness of each layer changes continuously. Therefore, when the film is divided into two at the halfway point, one half has a thicker average layer thickness and the other half has a thinner average layer thickness. Furthermore, when the film is applied to a substrate having a curved surface, the curvature of the inner curved surface side in the thickness direction of the film is larger by the thickness of the film.

[0106] In the prior art, there are examples of applying a film laminated with a thermoplastic resin layer to a curved surface, but the orientation of the film surface has not been given much consideration. As a result, when the film is applied to a curved surface, appearance defects sometimes occur and sometimes do not, and it has not been possible to consistently suppress appearance defects.

[0107] Therefore, as a result of extensive research, the inventors have found that it is important to arrange the film so that the layer group A with the thinner average layer thickness is on the inner curved surface side, as described above. A thinner average layer thickness means that each layer is thinner, and the thinner the layer, the more flexible each layer is and the easier it is to conform to complex shapes and unevenness. Therefore, by arranging the layer with the thinner average layer thickness on the inner curved surface side (the side with greater curvature), excellent shape conformability to complex shapes can be imparted, and this can be achieved stably.

[0108] The bonded body obtained by the present invention is glass or the like having a curved surface with few appearance defects, and is therefore suitable for windows of buildings and automobiles. In particular, it is suitable for windows that require high design quality, aesthetics, visibility from the inside, and internal heat insulation (comfort). It is also suitable as an information display member because it can prevent temperature rise in devices inside the screen while ensuring visibility of the screen. That is, the window or information display device of the present invention comprises a bonded body obtained by the manufacturing method of a bonded body of the present invention.

[0109] Next, the oriented film of the present invention will be described. The oriented film of the present invention has a structure in which two or more thermoplastic resin layers different in main component are regularly laminated in 51 to 2001 layers, and has a shrinkage ratio S at 150°C. 150 The direction in which the largest shrinkage (%) is the X direction, the direction perpendicular to the X direction in the film plane is the Y direction, and the shrinkage rate in the X direction at 150°C is S 150X (%), and the shrinkage rate in the Y direction at 150°C is S 150Y (%), S 150X -S 150Y ΔS 150 When this is the case, 0.7≦ΔS 150≦10.0. Such an oriented film can be obtained in the same manner as the film used in the manufacturing method of the bonded body of the present invention. In addition, the respective properties described for the film used in the manufacturing method of the bonded body of the present invention can also be applied to the oriented film of the present invention. [Example]

[0110] The film of the present invention will be described below with reference to specific examples. Even when a thermoplastic resin other than the thermoplastic resins specifically exemplified below is used, the film of the present invention can be obtained in the same manner as above, provided that the description of this specification, including the examples below, is taken into consideration.

[0111] [Methods for measuring physical properties and evaluating effects] The methods for evaluating the physical properties and the effects are as follows.

[0112] (1) Shrinkage rate S 150 , ΔS 150 Measurements were made under the following conditions using a Seiko Instruments Inc. heat, stress and strain measuring device (TMA / SS6000). Samples were cut out in a plane parallel to the film surface, in the longitudinal direction, and in each direction rotated up to 180° at 5° intervals in an in-plane direction parallel to the film surface. Each data point was set so that at least one data point was obtained per 1°C, and the shrinkage rate at each temperature was calculated using the following formula 3 to obtain a thermal shrinkage curve. Measurements were made three times in each direction, and the shrinkage rate S at 150°C was 150 The direction in which the shrinkage (%) was greatest was defined as the X direction, and the direction perpendicular to the X direction in the film plane was defined as the Y direction. The shrinkage rate in the X direction at 150°C was defined as S 150X (%), and the shrinkage rate in the Y direction at 150°C is S 150Y (%), and ΔS 150 =S 150X -S 150Y It was calculated as follows. Sample size: width 4mm, length 15mm Temperature range: 25 to 200°C Heating rate: 10°C / min Measurement load: 19.8N Temperature 23°C, relative humidity 65%, in the atmosphere Equation 3: Shrinkage rate S at 150°C 150 =(L(25)-L(150)) / L(25)×100 L(T): sample length at T°C.

[0113] (2) Number of layers, layer thickness, average layer thickness The number and thickness of film layers were determined by transmission electron microscopy (TEM) of samples thinned using an ultramicrotome. Specifically, the cross-section of the laminated film was observed using a JEM-1400 Plus transmission electron microscope (JEOL Ltd.) at an accelerating voltage of 100 kV. The number of layers was determined by obtaining cross-sectional images. To obtain a large contrast difference between each layer, a staining technique using an electron stain (e.g., RuO4) was used. Furthermore, depending on the thickness of each layer, observations were performed at a direct magnification of 40,000x for thin film layer thicknesses less than 100 nm, 20,000x for thin film layer thicknesses between 100 and 500 nm, and 1,000x to 10,000x for thin film layer thicknesses greater than 500 nm. The number and thickness of layers were determined based on the contrast difference in the obtained images. The average layer thickness of the corresponding area was calculated from the identified layer thickness.

[0114] (3) Layer interface (contrast difference) The cross-sectional images obtained by transmission electron microscope observation (2) were converted to compressed image files (JPEG), and position-brightness data was obtained by line profiling along the thickness direction of the laminate film using ImagePro-10 (sold by Hakuto Co., Ltd.). Then, using spreadsheet software (Microsoft Excel® 2016), the relationship between position and brightness was plotted, and a five-point moving average was applied to the resulting profile. The averaging process was performed by averaging brightness at five consecutive measurement positions, changing the position one by one and repeating the same calculation repeatedly to obtain an averaged position-brightness profile. In the obtained averaged position-brightness profile, the positions surrounded by inflection points where the slope changed from positive to negative or from negative to positive were determined to represent one layer. For each layer obtained using this method, position-brightness data was then obtained along the planar direction of the laminate film (the direction perpendicular to the thickness direction). After calculating the average and standard deviation of the brightness obtained for each layer, if the difference between the average brightness values ​​of two adjacent layers was greater than either of the standard deviations of the brightness values ​​of the adjacent thermoplastic resin layers, the two adjacent layers were determined to be different.

[0115] (4) Differential scanning calorimetry (DSC) A differential scanning calorimeter, EXSTAR DSC6220, manufactured by Hitachi High-Technologies Corporation, was used. Measurements and temperature readings were performed according to JIS-K-7122 (1987). Specifically, approximately 5 mg of sample was placed on an aluminum pan and heated from 25°C to 300°C at a rate of 10°C / min. The glass transition temperature Tg (°C) was determined as the intersection of the baseline when the sample was heated from room temperature and the tangent to the inflection point of the step transition. After heating, the sample was rapidly cooled with liquid nitrogen and heated again under the same conditions. The endothermic peak observed at the highest temperature was determined as the melting point (°C). The integrated value from the baseline within a range of ±20°C from the melting point was determined as the enthalpy of fusion (J / g).

[0116] (5)Reflectance A sample cut to 5cm x 5cm was subjected to reflectance measurement using a Hitachi spectrophotometer (U-4100 Spectrophotometer) with an integrating sphere attached, using the basic configuration. The measurement was performed using the aluminum oxide secondary white plate attached to the instrument as a reference. The sample was placed behind the integrating sphere with its longitudinal direction facing up and down, and the reflectance was measured under the following conditions. The presence or absence of a reflection band was confirmed, and the average reflectance in the wavelength range of 400nm to 700nm and the average reflectance in the wavelength range of 900nm to 1200nm were calculated. <Measurement conditions> Slit: 2nm (visible) / Automatic control (infrared) Gain: 2 Scanning speed: 600 nm / min Starting wavelength: 2600nm End wavelength: 240nm Sampling interval: 1 nm Incident angle: 10°.

[0117] (6) Preparation of the laminate First, a film having an adhesive layer as functional layer A was obtained as follows. A monomer mixture was prepared by mixing 83.3 parts by weight of 2-ethylhexyl acrylate, 14.7 parts by weight of N,N-dimethylacrylamide, 2.0 parts by weight of 2-hydroxyethyl acrylate, and 185.7 parts by weight of ethyl acetate. 0.2 parts by weight of V-65 was added as an initiator, and the mixture was allowed to react for 24 hours at 50°C under a nitrogen atmosphere to obtain a 35% ethyl acetate solution of a (meth)acrylic copolymer. Next, 100 parts by weight of the resulting (meth)acrylic copolymer solution was mixed with 2.19 parts by weight of Tinuvin™ 477 and 0.08 parts by weight of Coronate™ 2203. This mixture was applied to one side of the films obtained in Examples 1 to 22 and Reference Examples 1 to 3 to a thickness of 20 μm after drying, and then dried at 90°C for 5 minutes to obtain a film having an adhesive layer. In Examples 26, 27, 42, and 43, functional layer B and functional layer C were laminated on one side of the film obtained in Examples 1 and 12, and then functional layer A was laminated on the opposite side. The film was 300 mm square. Next, a working solution was prepared by dissolving 0.05% by mass of glycerin fatty acid ester in distilled water. The curved glass substrates 1 to 4 were used as substrates. The working solution was sprayed on the side opposite to the side to which the film was to be applied, and the side of the film without the adhesive layer was attached. Then, hot air was applied using a heat gun to the curved portion of the film that was not in contact with the glass, bringing it into contact with the glass surface, and the film was removed from the glass. A squeegee was used to bring the film into contact with the glass. The working solution was then sprayed on the side of the substrate to which the film was to be applied, and also on the surface of the adhesive layer of the film, and the film was attached to the side of the substrate to which the film was to be applied. The working solution between the film and the curved inner surface of the glass was scraped out using a squeegee toward the periphery of the film, while the film was pressed against the glass to obtain a formulation. The surface to which the film was applied (inner curved surface or outer curved surface), the thickness of the film on the inner curved surface side, and the angle between the X direction and the A direction were as shown in Table 2.

[0118] The following four types of substrates were used:

[0119] The radius of curvature of the substrate was measured using a laser interferometer (manufactured by ZYGO), and the direction with the smallest radius of curvature was designated as direction A. The reciprocal of the radius of curvature at that time was designated as maximum curvature κA. Next, the direction perpendicular to direction A was designated as direction B, and the reciprocal of the radius of curvature in that direction was designated as minimum curvature κB. Substrate 1: Transparent single-bent glass with a maximum curvature κA in the A direction of 0.0003 and a maximum curvature κB in the B direction of 0. Substrate 2: Transparent curved glass with a maximum curvature κA in the A direction of 0.0003 and a maximum curvature κB in the B direction of 0.0002. Substrate 3: Transparent curved glass with a maximum curvature κA in the A direction of 0.03 and a maximum curvature κB in the B direction of 0.0003. Substrate 4: Transparent single-bent glass with a maximum curvature κA in the A direction of 0.03 and a maximum curvature κB in the B direction of 0.

[0120] (7) Appearance of the laminate (wrinkles) The appearance of the laminated body produced in (6) was visually evaluated on the following 5-point scale, with B or higher being considered acceptable. SS: There were no wrinkles at all. S: There was a very slight wrinkle in one place. A: There were wrinkles in several places, about the same as an S grade. B: There were wrinkles in several places that exceeded the level of A. C: There were large wrinkles that were problematic for practical use.

[0121] (8) Interlayer adhesion The interlayer adhesion of the laminate produced in (6) was evaluated on the following two-level scale, with A being acceptable. A: There was no delamination. B: At least some delamination was observed.

[0122] (9) Heat insulation The total energy transmittance (Tts) through the laminate was measured in accordance with ISO 13837:2008 "Road vehicles - Safety glazing materials - Determination of solar transmittance" and rated on the following five-point scale. Note that light was incident from the outside of the bent glass. SS: The total energy transmittance (Tts) through the projection image display member was 50% or less. S: The total energy transmittance (Tts) through the projection image display member was greater than 50% and less than or equal to 60%. A: The total energy transmittance (Tts) through the projection image display member was greater than 60% and less than or equal to 70%. B: The total energy transmittance (Tts) through the projection image display member was greater than 70% and less than or equal to 80%. C: The total energy transmittance (Tts) through the projection image display component exceeded 80%.

[0123] (10) Visibility A sensory evaluation was conducted to assess the visibility of the background through the laminate, and the visual visibility was evaluated on the following three levels, with A and B being considered acceptable. A: The background looked clear. B: The background appeared dark enough that it would not cause any problems in practical use. C: The background appeared darker than the level of B, and the background was not visible.

[0124] (11) Calculation of the difference between the average in-plane refractive index and the refractive index perpendicular to the plane The in-plane average refractive index and in-plane normal refractive index of layer A of the film were measured using a Cylon Technology SPA-400 prism coupler. The laser wavelength used for the measurements was 633 nm. The in-plane average refractive index was the average of the values ​​measured along the main alignment axis and in the direction perpendicular to the main alignment axis, and the in-plane normal refractive index was the average of the values ​​measured along the main alignment axis and in the direction perpendicular to the main alignment axis. Layers B and C of the film are internal layers of the film, so measurements and calculations were performed in the same manner as above using films of the layer B resin alone or the layer C resin alone, prepared under the same conditions as the film, rather than using the film itself. The in-plane average refractive index and the in-plane normal refractive index were calculated as absolute values ​​obtained by subtracting the refractive indexes measured for each layer.

[0125] (12) In-plane phase difference A retardation measurement device (KOBRA-WPR) manufactured by Oji Scientific Instruments was used. The film was cut into a 10 cm square and placed on the large-format sample setting stage at the bottom of the device. The film was then analyzed for its orientation angle from 0°, as defined by the measurement device, and for in-plane retardation at 587 nm at normal incidence. The orientation angle was measured from -90° to 90°.

[0126] (Resin used in the film) The resins used in the examples of the present invention are described below. The refractive index difference was calculated from the in-plane average refractive index and the in-plane normal refractive index when a sheet made of each resin was stretched under the stretching conditions described in the examples. Within the range of stretching conditions described in the examples, the in-plane average refractive index and the in-plane normal refractive index all showed the same value. Resin 1: Crystalline homopolyethylene terephthalate resin (difference between in-plane average refractive index and perpendicular refractive index = 0.1) with a glass transition temperature of 78°C, a melting point of 254°C, and a melting enthalpy of 40 J / g. Resin 2: Crystalline polyethylene naphthalate resin (difference between in-plane average refractive index and perpendicular refractive index = 0.25) with a glass transition temperature of 124°C, a melting point of 262°C, a crystallization temperature of 200°C, and a melting enthalpy of 48 J / g. Resin 3: Amorphous polyethylene terephthalate resin copolymerized with 33 mol% cyclohexanedimethanol, exhibiting a glass transition temperature of 80°C (difference between the in-plane average refractive index and the perpendicular refractive index = less than 0.01). Resin 4: Amorphous homo-polymethylene methacrylate resin with a glass transition temperature of 101°C (difference between the average in-plane refractive index and the perpendicular in-plane refractive index = less than 0.01) Resin 5: Amorphous polyethylene terephthalate resin blend (difference between in-plane average refractive index and perpendicular refractive index = 0.05) made by blending Resin 3 and Resin 1 in an 85:15 ratio, exhibiting a glass transition temperature of 79°C. Resin 6: Amorphous polyethylene terephthalate resin blend (difference between in-plane average refractive index and perpendicular refractive index = 0.05) obtained by blending Resin 1 with polyethylene terephthalate resin copolymerized with 29 mol% spiroglycol and 21 mol% cyclohexanedicarboxylic acid in a ratio of 70:30, which has a glass transition temperature of 80°C. Resin 7: A crystalline polyethylene terephthalate resin copolymerized with 10 mol% isophthalic acid, with a glass transition temperature of 79°C, a melting point of 230°C, and a melting enthalpy of 12 J / g (difference between the in-plane average refractive index and the perpendicular refractive index = 0.08).

[0127] Example 1 Two thermoplastic resin layers with different main components were designated as layers A1 and B1, with resin 1 used as the thermoplastic resin for layer A1 and resin 3 used as the thermoplastic resin for layer B1. Resins 1 and 3 were melted at 280°C in separate extruders and passed through five FSS-type leaf disc filters to remove any foreign matter. They were then extruded using a gear pump while being metered to achieve a discharge ratio (lamination ratio) of resin 1 / resin 3 = 1.00 / 1.07, and the flows were combined in a 273-layer feed block. Both surface layers were made of resin 1. From one surface of the film to the opposite surface, the thickness of the final A1 layer (A1 layer made of resin 1) and the thickness of the final B1 layer (B1 layer made of resin 3) were varied geometrically from 130 nm to 180 nm, and from 137 nm to 190 nm, respectively, so that the adjacent thicknesses of the A1 layer and B1 layer, respectively, satisfied the above-mentioned formulas 1 and 2. (However, the thickness of the A1 layers located on both surface layers was adjusted to a final thickness of 10 μm.) The resulting molten laminate was then fed into a T-die to form a sheet. It was then quenched and solidified on a casting drum maintained at a surface temperature of 25°C while applying an electrostatic voltage of 8 kV with a wire, resulting in an unoriented sheet. This unoriented sheet was then longitudinally stretched by varying the peripheral speed of the rolls at a temperature of 90°C and a stretch ratio of 3.3 to obtain a uniaxially oriented sheet. The resulting uniaxially oriented sheet was then clamped at both ends with clips and introduced into a tenter, where it was transversely stretched at 100°C to a stretch ratio of 3.5, followed by heat treatment at 240°C for 10 seconds, followed by 2.0% transverse relaxation at the same temperature, and then cooled at 150°C for 10 seconds to obtain a 50μm thick film. The physical properties and characteristics of the resulting film are shown in Tables 1-1 and 1-2.

[0128] (Examples 2 to 13, 15 to 17, 19 to 20, 22, Reference Examples 1 and 2) A film was obtained in the same manner as in Example 1, except that the resin, film configuration, and film-forming conditions were as shown in Tables 1-1 and 1-2. The physical properties and characteristics of the obtained film are shown in Tables 1-1 and 1-2. The number of layers was adjusted by changing the number of slits in the feed block, and the thickness was adjusted by changing the extrusion rate of each resin (the same applies below).

[0129] Example 14 A film was obtained in the same manner as in Example 12, except that the film was heat-treated at 183°C for 10 seconds, relaxed by 3.6% in the width direction at the same temperature, and then further stretched by 3.1% in the width direction in a cooling zone at 150°C. The physical properties and characteristics of the obtained film are shown in Table 1-2.

[0130] Example 18 A film was obtained in the same manner as in Example 14, except that the relaxation in the width direction was as shown in Table 1-2. The physical properties and characteristics of the obtained film are shown in Table 1-2.

[0131] Example 21 Three thermoplastic resin layers with different main components were used, designated as layers A2, B2, and C2. Resin 1 was used as the thermoplastic resin for layer A2, Resin 7 as the thermoplastic resin for layer B2, and Resin 3 as the thermoplastic resin for layer C2. Resins 1, 7, and 3 were melted in separate extruders at 270°C, 270°C, and 280°C, respectively. Each extruded resin was passed through seven FSS-type leaf disc filters, and then metered and extruded using a gear pump to achieve a discharge ratio (lamination ratio) of Resin 1 / Resin 7 = 1.00 / 1.02 and Resin 3 / Resin 7 = 1.00 / 0.98. The extruded resins were then merged in a 601-layer feedblock. Both surface layers were made of A2, and the laminate was stacked in a regular arrangement of A2 / B2 / C2 / B2 layers through the thickness direction. The thicknesses of the A2, B2, and C2 layers were designed to provide a flat reflectance spectrum from 400 nm to 700 nm. That is, from one surface of the film to the opposite surface, the thickness of the final A2 layer was varied in a geometric progression from 130 nm to 180 nm, the thickness of the final B2 layer was varied from 137 nm to 190 nm, and the thickness of the final C2 layer was varied from 144 nm to 200 nm, so that the adjacent A2 and B2 layers, B2 and C2 layers, and C2 and A2 layers satisfied the above-mentioned formulas 1 and 2, respectively (however, the thickness of the A2 layers located on both surfaces was adjusted to a final thickness of 10 μm). Subsequently, film formation was performed in the same manner as in Example 1, except that the film formation conditions were as shown in Table 1-2, to obtain a film with a thickness of 80 μm. Note that the explanation of formulas 1 and 2 above assumes the combination of layers A and B, but should be interpreted accordingly depending on the combination. The physical properties and characteristics of the obtained film are shown in Table 1-2.

[0132] (Reference example 3) Resin 1 was used as the thermoplastic resin for the A1 layer, and Resin 4 was used as the thermoplastic resin for the B1 layer. Resins 1 and 2 were melted at 280°C in separate extruders and passed through five FSS-type leaf disc filters to remove any impurities. They were then extruded using a gear pump while being metered to a discharge ratio (lamination ratio) of Resin 1 / Resin 3 = 1.00 / 1.07, and the resulting mixtures were merged in a 273-layer feed block. The thickness of the final A1 layer was varied in a geometric progression from 130 nm to 180 nm, and the thickness of the final B1 layer was varied in a geometric progression from 137 nm to 190 nm, so that the adjacent A1 layer (made of Resin 1) and B1 layer (made of Resin 2) satisfied the aforementioned equations 1 and 2, respectively, from one surface of the film to the other. The resulting molten laminate was then fed into a T-die and formed into a sheet, after which it was rapidly cooled and solidified on a casting drum maintained at a surface temperature of 25°C while an electrostatic voltage of 8 kV was applied using a wire, yielding an unoriented sheet. The physical properties and characteristics of the resulting unoriented sheet (film) are shown in Table 1-2.

[0133] Example 23 Substrate 1 was used as the substrate, and the film obtained in Example 1 was used, and the film was arranged so that the film was the member on the curved inner surface side and the thickness of the film on the curved inner surface side was d2, and a bonded body was obtained by the method (6) above. The evaluation results of the obtained bonded body are shown in Table 2-1.

[0134] (Examples 24, 25, 28 to 41, 44 to 55, Comparative Examples 1 to 5) A laminate was obtained in the same manner as in Example 23, except that the configuration and production method of the laminate were as shown in Tables 2-1 and 2-2. The evaluation results of the obtained laminate are shown in Tables 2-1, 2-2, 2-3, and 2-4.

[0135] Example 26 The coating solution for functional layer B described below was coated on one side of the film obtained in Example 1 using a wire bar coater, and then dried in a hot air oven at 80°C for 2 minutes. Thereafter, ultraviolet rays of 300 mJ / cm were applied using a UV irradiation device. 2The coating was irradiated and cured to form a functional layer B, thereby obtaining a film having the functional layer B. The coating amount of the functional layer B was adjusted so that the dry film thickness was 3 μm. A bonded body was obtained in the same manner as in Example 23, except that the film obtained in this manner was used as shown in Table 2-1. The evaluation results of the obtained bonded body are shown in Table 2-1.

[0136] (Preparation of coating solution for functional layer B) DPHA (dipentaerythritol hexaacrylate), potassium tert-butoxide, and a photoinitiator (BASF Japan "IRGACURE" (registered trademark) 184) were mixed in a mass ratio of 99:1:1, and the solid content was adjusted to a concentration of 40% with MEK (methyl ethyl ketone). This coating material and cesium tungsten oxide particles (Cs) were mixed. 0.33 A slurry with a solid content concentration of WO3 of 20% by mass was mixed at a mass ratio of solids of 80:18.5 to prepare a coating liquid for functional layer B.

[0137] Example 27 The coating liquid for the functional layer C described below was coated on one side of the film obtained in Example 1 using a wire bar coater, and then dried in a hot air oven at 80°C for 2 minutes. Thereafter, ultraviolet rays of 300 mJ / cm were applied using a UV irradiation device. 2 The coating was cured by irradiation to form a functional layer C, thereby obtaining a film having the functional layer C. The coating amount of the functional layer C was adjusted so that the dry film thickness was 3 μm. A bonded body was obtained in the same manner as in Example 23, except that the film obtained in this manner was used as shown in Table 2-1. The evaluation results of the obtained bonded body are shown in Table 2-1.

[0138] (Preparation of coating solution for functional layer C) A coating solution for functional layer C was prepared by mixing DPHA (dipentaerythritol hexaacrylate), an ultraviolet absorber (trade name: Tinuvin 326, manufactured by BASF, benzotriazole-based), a photopolymerization initiator (trade name: Irgacure 184, manufactured by BASF, α-hydroxyacetophenone-based), and a photopolymerization initiator (trade name: OXE01, manufactured by BASF, oxime ester-based) in a weight ratio of 100:1.5:5:0.3, and then adding MEK (methyl ethyl ketone) and cyclohexanone to adjust the solids content to 40% by weight.

[0139] Example 42 A film was obtained, and further a laminate was obtained, in the same manner as in Example 26, except that the substrate was Substrate 3 and the film was Example 12. The evaluation results of the obtained laminate are shown in Table 2-3.

[0140] Example 43 A film was obtained, and further a laminate was obtained, in the same manner as in Example 27, except that the substrate was Substrate 3 and the film was Example 12. The evaluation results of the obtained laminate are shown in Table 2-3.

[0141] [Table 1-1]

[0142] [Table 1-2]

[0143] [Table 2-1]

[0144] [Table 2-2]

[0145] [Table 2-3]

[0146] [Table 2-4] [Industrial Applicability]

[0147] According to the present invention, it is possible to provide a method for manufacturing a bonded body that can suppress appearance defects even when attached to glass with a complex curved surface shape, and an oriented film that can be suitably used in the method for manufacturing the bonded body. Furthermore, the bonded body obtained by the method for manufacturing the bonded body of the present invention has excellent properties as described above, and therefore can be suitably used in windows and information display devices of automobiles, buildings, etc.

Claims

1. A method for producing a bonded body, comprising a bonding step of bonding a film onto a substrate, The film has a structure in which two or more thermoplastic resin layers having different main components are regularly laminated in 51 to 2001 layers, The shrinkage rate S of the film at 150°C １５０ The direction in which the shrinkage rate (%) is the largest is the X direction, the direction perpendicular to the X direction in the film plane is the Y direction, and the shrinkage rate in the X direction at 150°C is S １５０Ｘ (%), and the shrinkage rate in the Y direction at 150°C is S １５０Y (%), S １５０Ｘ -S １５０Y ΔS １５０ When this is the case, 0.7≦ΔS １５０ ≦10.0, The method for producing a bonded body, wherein the maximum curvature of the film in the X direction after the bonding step is 0.0001 or more and 0.1 or less.

2. The method for manufacturing a bonded body according to claim 1, wherein when a direction in which the curvature of the bonded body is maximum is defined as an A direction, an angle formed between the X direction and the A direction is 0° or more and 30° or less.

3. The film has a value of 0.1≦S １５０Ｘ <2.5 and -0.6≦S １５０Y The method for producing a bonded body according to claim 1 or 2, which satisfies <1.

8.

4. The method for producing a bonded body according to claim 3, wherein the maximum curvature κ A in the A direction is 0.0001 or more and 0.0050 or less.

5. The film has a S １５０Ｘ ≦20.0 and 3.3≦S １５０Y The method for producing a bonded body according to claim 1 or 2, wherein the bonded body satisfies the condition of ≦19.

7.

6. The method for producing a bonded body according to claim 5, wherein the maximum curvature κ A in the A direction is greater than 0.0050 and not more than 0.

1.

7. The method for producing a bonded body according to claim 1 or 2, wherein the film has a functional layer.

8. 3. The method for producing a bonded body according to claim 1 or 2, wherein the film has a continuous reflection band having a reflectance of 30% or more and 110% or less over a wavelength width of 20 nm or more and 1000 nm or less when light with a wavelength of 300 to 2500 nm is incident on the film at an incident angle of 10°.

9. The method for producing a bonded body according to claim 1 or 2, wherein the film has an average reflectance of 0% or more and 15% or less at a wavelength of 400 to 700 nm, and an average reflectance of 70% or more and 110% or less at a wavelength of 900 to 1200 nm.

10. When the thickness of the film is D, and among the layer groups divided into two at a position D / 2 from one surface, the layer group having the smaller average layer thickness constituting each layer group is called layer group A, and the layer group having the thicker average layer thickness is called layer group B, The method for producing a bonded body according to claim 1 or 2, wherein in the bonding step, the film is arranged so that the inner curved surface side is layer group A.

11. A window comprising a laminate obtained by the method for producing a laminate according to claim 1 or 2.

12. An information display device comprising a bonded body obtained by the method for producing a bonded body according to claim 1 or 2.

13. The laminate has a structure in which two or more thermoplastic resin layers having different main components are regularly laminated in 51 to 2001 layers, Shrinkage rate S at 150°C １５０ The direction in which the shrinkage rate (%) is the largest is the X direction, the direction perpendicular to the X direction in the film plane is the Y direction, and the shrinkage rate in the X direction at 150°C is S １５０Ｘ (%), and the shrinkage rate in the Y direction at 150°C is S １５０Y (%), S １５０Ｘ -S １５０Y ΔS １５０ When this is the case, 0.7≦ΔS １５０ An oriented film that satisfies ≦10.

0.

14. The oriented film according to claim 13, wherein each of the thermoplastic resin layers comprises a polyester resin.

15. 15. The oriented film according to claim 13 or 14, wherein the outermost layers on both sides of the film are the same layer, and the glass transition temperature of the thermoplastic resin that is the main component of the outermost layers is the highest among the main components of the thermoplastic resin layers that constitute the film.

16. 15. The oriented film according to claim 13 or 14, wherein the highest glass transition temperature of the oriented film is 90°C or higher and 140°C or lower.

17. 15. The oriented film according to claim 13, wherein the difference between the average in-plane refractive index and the perpendicular in-plane refractive index in at least one layer other than the outermost layer constituting the film is 0.01 or more and 0.30 or less.

18. 15. The oriented film according to claim 13, wherein the in-plane retardation is 1,500 nm or more and 10,000 nm or less.

19. 0.1≦S １５０Ｘ <2.5 and -0.6≦S １５０Y The oriented film according to claim 13 or 14, which satisfies <1.

8.

20. 4.0≦S １５０Ｘ ≦20.0 and 3.3≦S １５０Y The oriented film according to claim 13 or 14, which satisfies ≦19.

7.

21. The oriented film according to claim 13 or 14, wherein the film has a continuous reflection band with a reflectance of 30% to 110% over a wavelength range of 20 nm to 1000 nm when light with a wavelength of 300 to 2500 nm is incident at an incident angle of 10°.

22. The oriented film according to claim 13 or 14, wherein the average reflectance in the wavelength range of 400 to 700 nm is 0% or more and 15% or less, and the average reflectance in the wavelength range of 900 to 1200 nm is 70% or more and 110% or less.

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