Laminate

Abstract

This laminate comprises at least one releasable substrate, and at least one adhesive film comprising a thermoplastic resin composition containing a thermoplastic resin. The present invention makes it possible to provide a laminate having excellent dimensional stability.

Description

Laminate

[0001] The present invention relates to a laminate used as an interlayer film for laminated glass, an optically transparent adhesive for displays, and the like.

[0002] Conventionally, laminated glass, which is formed by interposing an interlayer film between two glass sheets and integrating them, has been widely known. The interlayer film is often formed from plasticized polyvinyl acetal, which is a polyvinyl acetal resin blended with a plasticizer. Laminated glass is safe because it hardly shatters glass fragments even if it is broken by external impact, and is therefore widely used as window glass in vehicles such as automobiles, aircraft, buildings, etc.

[0003] Laminated glass is generally produced by arranging two glass plates with an interlayer film, and after a preliminary degassing process, heating and pressurizing the glass and the interlayer film in an autoclave (ACV) process at a temperature of about 130°C to 140°C and a pressure of about 1.3 MPa.

[0004] In recent years, there has been a demand for laminated glass incorporating a light-control film and displays with reduced glass shatter resistance. When incorporating a light-control film into laminated glass, it is known that an interlayer film is disposed between the light-control film and each glass plate, and the two glass plates and the light-control film are integrated via the interlayer film (see, for example, Patent Document 1). In addition, in display applications, an optically transparent adhesive (OCA) is sometimes used to bond various components such as a cover glass to an image display panel, and it has been considered to use an adhesive film made of a polyvinyl acetal resin or the like for the optically transparent adhesive, similar to the interlayer film.

[0005] International Publication No. 2019 / 066042

[0006] Another method for incorporating functional elements such as light-control films into laminated glass involves embedding the functional elements within the frame of a picture-frame-shaped interlayer film. In this case, if there is a gap between the interlayer film frame and the functional element, bubbles may form. For this reason, the interlayer film frame must have high dimensional accuracy. Furthermore, when an interlayer film is used in a display as an optically clear adhesive (OCA) to prevent glass shattering, the size of the interlayer film must be matched to the size of the other components. This requires minimizing the dimensional difference between the interlayer film and the other components, so that the edges are aligned with the other components, creating a so-called just-edge effect.

[0007] However, when an interlayer film is produced by extrusion molding a thermoplastic resin composition using a conventional method, the interlayer film is stretched due to differences in roll speed during transport, which leaves distortion in the interlayer film, resulting in poor dimensional stability. Furthermore, if the interlayer film is embossed to prevent self-adhesion, tension is generated in the interlayer film, further worsening the dimensional stability of the interlayer film. Even if the interlayer film is processed with high processing accuracy, poor dimensional stability of the interlayer film will result in low dimensional accuracy. Therefore, in order to use the interlayer film as a component requiring high dimensional accuracy, it was necessary to improve the dimensional stability of the interlayer film.

[0008] Therefore, an object of the present invention is to provide a laminate having excellent dimensional stability that can be suitably used as an interlayer film for laminated glass, an optically transparent adhesive for displays, and the like.

[0009] As a result of extensive research, the present inventors have found that the above problems can be solved by providing a laminate with a release substrate, and have completed the present invention as described below. That is, the present invention provides the following [1] to

[16] .

[0010] [1] A laminate comprising at least one release substrate and at least one adhesive film made of a thermoplastic resin composition containing a thermoplastic resin. [2] The laminate according to [1] above, wherein the thermoplastic resin is polyvinyl butyral resin (PVB). [3] The laminate according to [1] above, wherein the thermoplastic resin is ethylene-vinyl acetate copolymer resin (EVA). [4] The laminate according to any one of [1] to [3] above, wherein the absolute value of the rate of dimensional change in the length in the machine direction (MD) before and after the following accelerated test ((length after test - length before test) ÷ (length before test) x 100) is 1% or less, and the absolute value of the rate of dimensional change in the length in the cross direction (TD) before and after the following accelerated test ((length after test - length before test) ÷ (length before test) x 100) is 1% or less. (Accelerated Test) (1) Samples measuring 20 mm x 100 mm are cut from the laminate so that the machine direction (MD) and the cross direction (TD) of the laminate respectively coincide with the longitudinal direction of the sample. Thereafter, heat-resistant tape is applied to the sample within 1 mm from the end of the short side. (2) The sample is hung from the heat-resistant tape side in a thermostatic chamber set to conditions of a temperature of 80°C and a humidity of 40% RH so that the long side of the sample is perpendicular, and maintained for 20 minutes. (3) 20 minutes after hanging the sample in the thermostatic chamber, the sample is removed from the thermostatic chamber. [5] The laminate according to any one of [1] to [4] above, in which the absolute value of the dimensional change rate of thickness before and after the following accelerated test ((thickness after test - thickness before test) ÷ (thickness before test) × 100) is 5% or less. (Accelerated Test) (1) Samples measuring 20 mm x 100 mm are cut from the laminate so that the length direction (MD) and width direction (TD) of the laminate are aligned with the longitudinal direction of the sample. Thereafter, heat-resistant tape is applied to the sample within 1 mm from the end of the short side. (2) The sample is hung from the heat-resistant tape side so that the long side of the sample is vertical in a thermostatic chamber set to a temperature of 80°C and a humidity of 40% RH, and is held for 20 minutes. (3) After 20 minutes have passed since the sample was hung in the thermostatic chamber, the sample is removed from the thermostatic chamber.[6] The laminate according to any one of [1] to [5] above, wherein the absolute value of the dimensional change rate of the length in the machine direction (MD) of the release substrate before and after the following accelerated test ((length after test - length before test) ÷ (length before test) x 100) is 0.5% or less, and the absolute value of the dimensional change rate of the length in the width direction (TD) of the release substrate before and after the following accelerated test ((length after test - length before test) ÷ (length before test) x 100)) is 0.5% or less. (Accelerated Test) (1) Samples measuring 20 mm x 100 mm are cut out from the release substrate so that the machine direction (MD) and width direction (TD) of the release substrate coincide with the longitudinal directions of the samples. Thereafter, heat-resistant tape is attached to the samples within 1 mm from the ends of the short sides. (2) The sample is hung from the heat-resistant tape side in a thermostatic chamber set to conditions of a temperature of 80°C and a humidity of 40% RH with the long side of the sample aligned vertically, and held for 20 minutes. (3) After 20 minutes have passed since the sample was hung in the thermostatic chamber, the sample is removed from the thermostatic chamber. [7] The laminate according to any one of items [1] to [6] above, wherein the release substrate is at least one substrate selected from the group consisting of release film, release paper, mesh material, metal, and prepreg, and the resin constituting the release film is polyester resin, polyolefin resin, polyimide resin, fluororesin such as tetrafluoroethylene, silicone resin, liquid crystal polymer, polysulfone resin, cellulose acetate, polyamide resin, polyether ether ketone resin, polyether ketone ketone resin, modified polyphenylene ether, polyphenylene sulfide resin, polycarbonate resin, or polybenzimidazole resin. "8" The laminate according to any one of the above [1] to [7], wherein the thickness of the adhesive film is 10 μm or more and 3 mm or less. [9] The laminate according to any one of the above [1] to [8], wherein the thickness of the releasable substrate is 10 μm or more and 200 μm or less.

[10] The laminate according to any one of the above [1] to [9], wherein the peel strength when peeling the releasable substrate from the adhesive film is 0.02 N / 25 mm or more and 7 N / 25 mm or less.

[11] The laminate according to any one of [1] to

[10] above, comprising one release substrate and one adhesive film, wherein the peel strength when the release substrate is peeled from the adhesive film is 0.03 N / 25 mm or more and 7 N / 25 mm or less.

[12] The laminate according to any one of [1] to

[10] above, comprising release substrates on both sides of the adhesive film, wherein the release substrate provided on one side of the adhesive film is designated as a first release substrate and the release substrate provided on the other side of the adhesive film is designated as a second release substrate, and wherein the peel strength ratio (B / A) of the peel strength B (N / 25 mm) when the second release substrate is peeled from the adhesive film to the peel strength A (N / 25 mm) when the first release substrate is peeled from the adhesive film is 1.3 or more.

[13] The laminate according to

[12] above, wherein the peel strength A when the first releasable substrate is peeled from the adhesive film is 0.03 N / 25 mm or more and 0.5 N / 25 mm or less, and the peel strength B when the second releasable substrate is peeled from the adhesive film is 0.05 N / 25 mm or more and 7 N / 25 mm or less.

[14] The laminate according to

[12] or

[13] above, wherein the first releasable substrate is thinner than the second releasable substrate.

[15] The laminate according to any one of [1] to

[14] above, wherein the releasable substrate comprises an adhesion adjusting layer.

[16] The laminate according to any one of [1] to

[15] above, wherein the surface roughness Rz of the release surface of the adhesive film after peeling the releasable substrate is 3 μm or more and 10 μm or less.

[17] The laminate according to any one of [1] to

[15] , wherein the surface roughness Rz of the release surface of the adhesive film after peeling off the release substrate is less than 3 μm.

[18] The laminate according to any one of [1] to

[15] or

[17] , wherein the surface roughness Rz of the release surface of the adhesive film after peeling off the release substrate is less than 1 μm.

[19] The laminate according to any one of [1] to

[15] above, wherein the thermoplastic resin composition contains 20 parts by mass or more and 70 parts by mass or less of a plasticizer per 100 parts by mass of the thermoplastic resin.

[0011] According to the present invention, a laminate having excellent dimensional stability can be provided.

[0012] FIG. 1 is a diagram illustrating a first embodiment of the method for producing a laminate of the present invention. FIG. 2 is a diagram illustrating the first embodiment of the method for producing a laminate of the present invention. FIG. 3 is a diagram illustrating an example of a tan δ-temperature curve. FIG. 4 is a diagram illustrating a second embodiment of the method for producing a laminate of the present invention. FIG. 5 is a diagram illustrating the second embodiment of the method for producing a laminate of the present invention. FIG. 6 is a diagram illustrating a third embodiment of the method for producing a laminate of the present invention. FIG. 7 is a diagram illustrating the third embodiment of the method for producing a laminate of the present invention. FIG. 8 is a diagram illustrating a fourth embodiment of the method for producing a laminate of the present invention.

[0013] <Laminate> The laminate of the present invention comprises at least one release substrate and at least one adhesive film made of a thermoplastic resin composition containing a thermoplastic resin. The release substrate suppresses shrinkage of the adhesive film, resulting in the laminate of the present invention having excellent dimensional stability. Furthermore, by peeling off the release substrate immediately before attaching the laminate to the adherend, or by peeling off the release substrate after attaching the laminate to the adherend, the dimensional accuracy of the adhesive film attached to the adherend can be improved.

[0014] [Dimensional Change Rate in Machine Direction (MD) Length and Transverse Direction (TD) Length] In the laminate of the present invention, the absolute value of the dimensional change rate in the machine direction (MD) length before and after the accelerated test ((length after test - length before test) ÷ (length before test) × 100) is preferably 1% or less, and the absolute value of the dimensional change rate in the transverse direction (TD) length before and after the accelerated test ((length after test - length before test) ÷ (length before test) × 100) is preferably 1% or less. The accelerated test is performed as follows. (Accelerated Test) (1) Samples measuring 20 mm × 100 mm are cut out from the laminate so that the machine direction (MD) and the transverse direction (TD) of the laminate coincide with the longitudinal direction of the sample. Then, double-sided tape is attached to the sample within 1 mm from the end of the short side. (2) The sample is hung from the heat-resistant tape side in a thermostatic chamber set at a temperature of 80°C and a humidity of 40% RH, with the long side of the sample oriented vertically, and held for 20 minutes. (3) After 20 minutes have passed since hanging the sample in the thermostatic chamber, the sample is removed from the thermostatic chamber. It is recommended to use a double-sided tape with heat resistance that can maintain the sample suspended in the accelerated test environment described above, such as a double-sided tape made of polyimide called Kapton (registered trademark) tape. One side of the double-sided tape is attached to the sample, and the other side is attached to the thermostatic chamber. When measuring the dimensional change rate in the MD, the long side of the sample should be aligned with the MD, and when measuring the dimensional change rate in the TD, the long side of the sample should be aligned with the TD. The thermostatic chamber can be, for example, a thermo-hygrostat (manufactured by Espec Corporation, model "PHP-2J").

[0015] The length of the sample was measured using a JIS Class 1 ruler (with a 0.5 mm scale pitch) in the longitudinal direction (MD) and transverse direction (TD) after the temperature of the sample removed from the thermostatic chamber had been confirmed to be the same as room temperature. The length of the sample was determined by measuring the value of the scale mark closest to the length of the sample. The accelerated test was also performed on three samples, and the average values ​​of the lengths of the three samples in the longitudinal direction (MD) and transverse direction (TD) were determined as the lengths of the sample in the longitudinal direction (MD) and transverse direction (TD).

[0016] When the absolute value of the dimensional change rate of the laminate is 1% or less, the dimensional stability of the laminate is further improved. This makes the laminate of the present invention suitable for use as an interlayer film for laminated glass, an optically transparent adhesive for displays, and the like. From this perspective, the absolute value of the dimensional change rate in the length direction (MD) before and after the accelerated test is more preferably 0.5% or less, even more preferably 0.4% or less, and even more preferably 0.2% or less. The lower limit of the range of the absolute value of the dimensional change rate in the length direction (MD) before and after the accelerated test is, for example, 0%. Furthermore, from the above-mentioned perspective, the absolute value of the dimensional change rate in the width direction (TD) before and after the accelerated test is more preferably 0.5% or less, even more preferably 0.4% or less, and even more preferably 0.2% or less. The lower limit of the range of the absolute value of the dimensional change rate in the width direction (TD) before and after the accelerated test is, for example, 0%. The absolute value of the dimensional change rate of the laminate can be adjusted by the type of resin constituting the release substrate, the thickness of the release substrate, or the manufacturing process of the laminate.

[0017] [Dimensional change rate of thickness] In the laminate of the present invention, the absolute value of the dimensional change rate of thickness before and after the accelerated test ((thickness after test - thickness before test) ÷ (thickness before test) × 100) is preferably 5% or less. The accelerated test is as described above. Furthermore, measurements are taken of three samples each with the long side oriented in the MD and three samples with the long side oriented in the TD, and the average dimensional change rate of thickness is calculated, and the larger absolute value of the average dimensional change rate of thickness is taken as the dimensional change rate of thickness of that sample.

[0018] After confirming that the temperature of the sample removed from the thermostatic chamber has reached room temperature, the sample thickness is measured using a digital indicator (minimum display value: 0.0005 mm) conforming to or with equivalent accuracy to JIS B7563. Accelerated testing is performed on three samples, and the average thickness of the three samples is taken as the sample thickness. Thickness measurements are performed in an environment with a temperature of 17 to 23°C ± 2°C. An SR7 hemispherical indenter is used as the measuring probe. The measuring force when pressing the measuring probe against the sample is set between 0.1 and 0.4 N, and is consistent throughout the measurements. The measuring probe is then removed from the sample and allowed to stand until the thickness change per 10 seconds is equal to or less than the minimum display value (0.0005 mm or less). The remaining time is the time from removal of the measuring probe until the thickness change per 10 seconds is equal to or less than the minimum display value. The standing time should be measured in advance, and if the standing time differs between the sample before and after the accelerated test, the longer standing time should be used as the standing time. When measuring the thickness, the standing time should be the same before and after the accelerated test (with an error of ±2 seconds or less).

[0019] When the absolute value of the dimensional change rate of the thickness of the laminate is 5% or less, the dimensional stability of the laminate is further improved. From this perspective, the absolute value of the dimensional change rate of the thickness before and after the accelerated test is more preferably 2.5% or less, even more preferably 2% or less, even more preferably 1.5% or less, and even more preferably 1.0% or less. The lower limit of the range of the absolute value of the dimensional change rate of the thickness before and after the accelerated test is, for example, 0%. The absolute value of the dimensional change rate of the laminate can be adjusted by the type of resin constituting the release substrate and the thickness of the release substrate, or the manufacturing process of the laminate.

[0020] [Releaseable Substrate] The releaseable substrate used in the present invention preferably has an absolute value of 0.5% or less as a dimensional change rate in the length in the machine direction (MD) of the release substrate before and after the following accelerated test ((length after test - length before test) ÷ (length before test) × 100). Furthermore, the absolute value of dimensional change rate in the width direction (TD) of the release substrate before and after the following accelerated test ((length after test - length before test) ÷ (length before test) × 100) is preferably 0.5% or less. (Accelerated Test) The accelerated test of the releaseable substrate is carried out in the same manner as the accelerated test of the laminate described above.

[0021] When the absolute value of the dimensional change rate of the length in the longitudinal direction (MD) of the release substrate before and after the accelerated test is 0.5% or less, the absolute value of the dimensional change rate of the laminate can be further reduced. From this perspective, the absolute value of the dimensional change rate of the length in the longitudinal direction (MD) of the release substrate before and after the accelerated test is more preferably 0.4% or less, even more preferably 0.3% or less, and even more preferably 0.1% or less. The lower limit of the range of the absolute value of the dimensional change rate of the length in the longitudinal direction (MD) of the release substrate before and after the accelerated test is not particularly limited, but is, for example, 0%. Furthermore, when the absolute value of the dimensional change rate of the length in the width direction (TD) of the release substrate before and after the accelerated test is 0.5% or less, the absolute value of the dimensional change rate of the laminate can be further reduced. From this perspective, the absolute value of the dimensional change rate of the length in the width direction (TD) of the release substrate before and after the accelerated test is more preferably 0.4% or less, even more preferably 0.3% or less, and even more preferably 0.1% or less. The lower limit of the absolute value of the dimensional change rate of the width direction (TD) length of the release substrate before and after the accelerated test is not particularly limited, but is, for example, 0%.The absolute value of the dimensional change rate of the release substrate can be adjusted depending on the type of release substrate.In addition, when the release substrate is a release film, it can be adjusted depending on the type of resin constituting the release substrate and the thickness of the release substrate.

[0022] The length of the sample was measured using a JIS Class 1 ruler (with a 0.5 mm scale pitch) in the longitudinal direction (MD) and transverse direction (TD) after the temperature of the sample removed from the thermostatic chamber had been confirmed to be the same as room temperature. The length of the sample was determined by measuring the value of the scale mark closest to the length of the sample. The accelerated test was also performed on three samples, and the average values ​​of the lengths of the three samples in the longitudinal direction (MD) and transverse direction (TD) were determined as the lengths of the sample in the longitudinal direction (MD) and transverse direction (TD).

[0023] The release substrate is not particularly limited as long as it can be released from the adhesive film. Examples of the release substrate include release films, release papers, mesh materials, metals, prepregs, etc. These release substrates can be used alone or in combination of two or more. For example, a release film laminated with a mesh material or metal can also be used.

[0024] The release film may be any known resin film, and examples of the resin constituting the release film include, but are not limited to, polyester resin, polyolefin resin, polyimide resin, fluororesin such as tetrafluoroethylene, silicone resin, liquid crystal polymer, polysulfone resin, cellulose acetate, polyamide resin, polyether ether ketone resin, and polyether ketone ketone resin.

[0025] Examples of polyester resins include polyethylene terephthalate resin (PET), polyethylene terephthalate glycol resin (PETG), polybutylene naphthalate resin (PBN), polybutylene terephthalate resin (PBT), polytrimethylene terephthalate resin (PTT), polyhexamethylene terephthalate resin (PHT), copolymerized polyethylene terephthalate-isophthalate resin (PET / PEI), polyethylene naphthalate resin (PEN), and polylactic acid resin. Preferred polyester resins include PET, PEN, and PBN, with PET being more preferred. Examples of polyolefin resins include polyethylene resins such as ultra-high molecular weight polyethylene, high-density polyethylene, low-density polyethylene, and linear low-density polyethylene, polypropylene resin, polymethylpentene resin (PMP), and cyclic olefin resin (COP). Among these, polypropylene resin and polymethylpentene resin (PMP) are more preferred. Examples of fluororesins include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE or CTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), perfluoroalkoxy fluororesin (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and tetrafluoroethylene-perfluoroalkoxyethylene copolymer. Among these, polytetrafluoroethylene is more preferred. Examples of polysulfone resins include polysulfone (PSU), polyphenylsulfone (PPSU), and polyethersulfone (PES). In addition to these resins, modified polyphenylene ether, polyphenylene sulfide resin, polycarbonate resin, polybenzimidazole resin, and the like can also be suitably used. Of these, polyolefin resins and polyester resins are preferred, and among these, PET, polyethylene resins, polypropylene resins (PP), and polymethylpentene resins are preferred, with PET and PP being more preferred, and PET being even more preferred.Therefore, the film substrate constituting the release film is preferably a polyolefin resin film or a polyester resin film, more preferably a PET film or a PP film, and even more preferably a PET film.

[0026] These resins may be used alone or in combination of two or more. The film substrate may be composed of a single layer or may have a multilayer structure of two or more layers. When it has a multilayer structure of two or more layers, the resins constituting each layer may be the same or different. The resin film may be a non-stretched film or a stretched film. For example, a stretched PP film is preferred from the viewpoint of heat resistance, and a biaxially stretched PP film is more preferred.

[0027] The release film may have an adhesive strength adjusting layer. This makes it easier to adjust the peel strength when peeling the releasable substrate from the adhesive film. The adhesive strength adjusting layer is preferably provided on the surface facing the adhesive film.

[0028] The adhesive strength adjusting layer may be a release layer that improves the releasability when peeling off the adhesive film. When the adhesive strength adjusting layer is a release layer, examples of the resin constituting the release layer include silicone resin, fluororesin, melamine resin, epoxy resin, phenolic resin, and acrylic resin. These resins can be used alone or in combination of two or more. Among these, silicone resins are preferred.

[0029] The thickness of the adhesion adjusting layer is preferably 0.01 μm or more and 20 μm or less, more preferably 0.05 μm or more and 10 μm or less, and even more preferably 0.08 μm or more and 5 μm or less.

[0030] The adhesion adjusting layer may be formed from a primer of a urethane resin or a polyethylene resin, in addition to being formed from the above-mentioned resins. Among these, a urethane resin is preferred. The urethane resin primer increases the polarity of the surface of the release film, thereby improving the adhesive strength of the surface of the release film. The adhesion adjusting layer may also be formed by corona treatment or plasma treatment of the surface of the release film. By corona treatment or plasma treatment of the surface of the release film, functional groups are generated on the surface of the release film, which increases the polarity of the surface of the release film and allows the adhesive strength of the surface of the release film to be adjusted.

[0031] The release paper may be a known release paper, preferably one having a release layer provided on at least one surface of the paper substrate. The release layer may be provided on the surface of the adhesive film. The release layer may be formed from a release agent, which may be a silicone-based release agent or a non-silicone-based release agent. In the case of a silicone-based release agent, a silicone resin may be used as the resin in the release agent. In the case of a silicone-based release agent, a silicone resin may be used as the resin in the release agent. In addition, examples of resins used in non-silicone-based release agents include fluororesins, melamine resins, epoxy resins, phenolic resins, and acrylic resins. In addition, the paper substrate used for the release paper may be one that has been treated to prevent the release agent from penetrating the base paper, such as glassine paper, seal-coated paper, PE-laminated paper, or PET-laminated paper.

[0032] Examples of mesh materials include resin mesh and metal mesh. Resin meshes may be woven or knitted fabrics made of resin fibers, or nonwoven fabrics. The resins used in the resin mesh may be any of the resins listed above for use in the release film. Examples of metal meshes include aluminum mesh, stainless steel mesh, and copper mesh. Examples of metals include metal foils such as aluminum foil, stainless steel foil, and copper foil, as well as metal plates. Metal plates may be thin and flexible, and examples include aluminum plates, stainless steel plates, and copper plates. Examples of pre-polymers include those obtained by impregnating reinforcing fibers such as glass fibers and carbon fibers with matrix resins such as epoxy resins, modified polyphenylene ether resins, polyimide resins, and polybenzoxazole resins.

[0033] As the release substrate, a release film is more preferred from the viewpoint of ease of handling and further reducing the thermal shrinkage rate. Furthermore, the release film is preferably one in which the film substrate is a PET film, or one in which the film substrate is a PET film and an adhesive strength adjusting layer made of a silicone resin is provided on at least one surface of the film substrate. In this case, the adhesive film is laminated directly on the PET film, or is laminated on the PET film via an adhesive strength adjusting layer made of a silicone resin.

[0034] The release substrate may have an uneven structure on its surface. The release substrate may have an uneven structure on at least the surface on the adhesive film side. A mesh material is preferably used as a release substrate having an uneven structure. Furthermore, release substrates other than mesh materials may also have an uneven structure as appropriate, for example, a release film having an uneven structure on its surface. By using a release substrate having an uneven structure on its surface, the unevenness can be transferred to the adhesive film, and the adhesive film surface can be made uneven. Therefore, for example, the adhesive film can have improved adhesion to other members after the release substrate is peeled off.

[0035] The thickness of the release substrate is preferably 10 μm or more and 200 μm or less. When the thickness of the release substrate is 10 μm or more, the absolute value of the dimensional change rate of the laminate before and after the accelerated test can be further reduced. When the thickness of the release substrate is 200 μm or less, the handling of the laminate becomes even easier. From this viewpoint, the thickness of the release substrate is more preferably 20 μm or more and 150 μm or less, and even more preferably 30 μm or more and 130 μm or less.

[0036] The peel strength when peeling the releasable substrate from the adhesive film is preferably 0.02 N / 25 mm or more and 7 N / 25 mm or less. When the peel strength is 0.02 N / 25 mm or more, it is possible to prevent the releasable substrate from unintentionally peeling from the adhesive film before carrying out the step of peeling the releasable substrate from the adhesive film. When the peel strength is 7 N / 25 mm or less, it is possible to more easily peel the releasable substrate from the adhesive film. From this viewpoint, the peel strength when peeling the releasable substrate from the adhesive film is more preferably 0.03 N / 25 mm or more and 6 N / 25 mm or less, even more preferably 0.05 N / 25 mm or more and 5 N / 25 mm or less, even more preferably 0.1 N / 25 mm or more and 5 N / 25 mm or less, and even more preferably 1.4 N / 25 mm or more and 5 N / 25 mm or less. The peel strength when peeling the releasable substrate from the adhesive film can be measured by the method described in the Examples below. The peel strength when peeling the releasable substrate from the adhesive film can be adjusted by the type of resin in the releasable substrate, and when the releasable substrate has the above-mentioned adhesion adjusting layer, by the type of resin constituting the adhesion adjusting layer and the thickness of the adhesion adjusting layer.

[0037] When the laminate comprises one releasable substrate and one adhesive film, the peel strength when peeling the releasable substrate from the adhesive film is preferably 0.03 N / 25 mm or more and 7 N / 25 mm or less. Note that when the laminate comprises one releasable substrate and one adhesive film, it means that the releasable substrate is laminated on one side of the adhesive film, and the releasable substrate is not laminated on the other side of the adhesive film. When the peel strength is 0.03 N / 25 mm or more, it is possible to prevent the releasable substrate from unintentionally peeling from the adhesive film before carrying out the step of peeling the releasable substrate from the adhesive film. When the peel strength is 7 N / 25 mm or less, the releasable substrate can be easily peeled from the adhesive film. From this viewpoint, the peel strength when peeling the release substrate from the adhesive film is more preferably 0.05 N / 25 mm or more and 6 N / 25 mm or less, even more preferably 0.1 N / 25 mm or more and 3 N / 25 mm or less, and even more preferably 1.4 N / 25 mm or more and 3 N / 25 mm or less. The peel strength when peeling the release substrate from the adhesive film can be measured by the method described in the Examples below. The peel strength when peeling the release substrate from the adhesive film can be adjusted by the type of resin of the release substrate. Furthermore, when the release substrate has an adhesive strength adjustment layer described below, it can be adjusted by the type of resin constituting the adhesive strength adjustment layer and the thickness of the adhesive strength adjustment layer.

[0038] When the laminate has the release substrate on both sides of the adhesive film, the release substrate provided on one side of the adhesive film is referred to as the first release substrate, and the release substrate provided on the other side of the adhesive film is referred to as the second release substrate. The peel strength of the first release substrate and the peel strength of the second release substrate preferably have the following relationship. The peel strength ratio (B / A) of the peel strength A (N / 25 mm) when the first release substrate is peeled from the adhesive film to the peel strength B (N / 25 mm) when the second release substrate is peeled from the adhesive film is preferably 1.3 or more. When the peel strength ratio (B / A) is 1.3 or more, peeling of the adhesive film from the second release substrate can be suppressed when only the first release substrate is peeled from the adhesive film. From this viewpoint, the peel strength ratio (B / A) is more preferably 1.5 or more, and even more preferably 2 or more. The upper limit of the range of the peel strength ratio (B / A) is not particularly limited, but may be, for example, 250, 233, 100, 50, 10, 5, or the like.

[0039] The peel strength A when peeling the first releasable substrate from the adhesive film preferably satisfies the above peel strength ratio (B / A) and is 0.03 N / 25 mm or more and 0.5 N / 25 mm or less. When the above peel strength ratio (B / A) is satisfied and the peel strength A is 0.03 N / 25 mm or more, unintentional peeling of the first releasable substrate from the adhesive film can be suppressed before performing the step of peeling the first releasable substrate from the adhesive film. When the peel strength A is 0.5 N / 25 mm or less, unintentional peeling of the adhesive film from the second releasable substrate can be suppressed when peeling the first releasable substrate from the adhesive film. From this perspective, the peel strength A when peeling the first releasable substrate from the adhesive film is more preferably 0.1 N / 25 mm or more, even more preferably 0.25 N / 25 mm or more. The peel strength A when peeling the first releasable substrate from the adhesive film can be measured by the method described in the examples below. The peel strength A when the first releasable substrate is peeled from the adhesive film can be adjusted by the type of resin in the first releasable substrate. Furthermore, when the first releasable substrate has an adhesion adjusting layer described below, the peel strength A can be adjusted by the type of resin constituting the adhesion adjusting layer and the thickness of the adhesion adjusting layer.

[0040] The peel strength B when peeling the second releasable substrate from the adhesive film preferably satisfies the above peel strength ratio (B / A) and is 0.05 N / 25 mm or more and 7 N / 25 mm or less. When the above peel strength ratio (B / A) is satisfied and the peel strength B is 0.05 N / 25 mm or more, it is possible to prevent the adhesive film from unintentionally peeling from the second releasable substrate when peeling the first releasable substrate from the adhesive film. When the peel strength B is 7 N / 25 mm or less, the second releasable substrate can be more easily peeled from the adhesive film. From this perspective, the peel strength B when peeling the second releasable substrate from the adhesive film is more preferably 0.1 N / 25 mm or more and 6 N / 25 mm or less, even more preferably 0.5 N / 25 mm or more and 5 N / 25 mm or less, and even more preferably 1 N / 25 mm or more. The peel strength B when peeling the second releasable substrate from the adhesive film can be measured by the method described in the examples below. The peel strength B when the second releasable substrate is peeled from the adhesive film can be adjusted by the type of resin in the second releasable substrate. Furthermore, when the second releasable substrate has an adhesion adjusting layer as described below, the peel strength B can be adjusted by the type of resin constituting the adhesion adjusting layer and the thickness of the adhesion adjusting layer.

[0041] The first release substrate is preferably thinner than the second release substrate. This can further prevent the PSA film from unintentionally peeling from the second release substrate when peeling the first release substrate from the adhesive film. From this perspective, the thickness of the first release substrate is preferably 30% to 84% of the thickness of the second release substrate, more preferably 40% to 80%. It is even more preferably 50% to 75%.

[0042] [Adhesive Film] The adhesive film is made of a thermoplastic resin composition containing a thermoplastic resin.

[0043] (Thermoplastic Resin) Examples of thermoplastic resins contained in the thermoplastic resin composition include (meth)acrylic resins, polyvinyl acetal resins, polyvinyl alcohol resins (PVA), polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), saponified ethylene-vinyl acetate copolymers (EVOH), ethylene-methacrylic acid copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, and styrene-butadiene copolymer resins. These thermoplastic resins may be used alone or in combination of two or more. Among these thermoplastic resins, ethylene-vinyl acetate copolymer resins (EVA) and polyvinyl acetal resins are preferred, polyvinyl acetal resins are more preferred, and polyvinyl butyral resins (PVB) are even more preferred. EVA and PVB have relatively low dimensional stability when formed into a film, but by laminating a release substrate on at least one side as in the present invention, excellent dimensional stability can be achieved.

[0044] (Polyvinyl acetal resin) The polyvinyl acetal resin used as the thermoplastic resin of the thermoplastic resin composition may be a modified polyvinyl acetal resin or an unmodified polyvinyl acetal resin. As described below, the modified polyvinyl acetal resin may have a structure (modifying group) other than an acetal group, a hydroxyl group, and an acetyl group, and preferably has a modifying group on a side chain. The polyvinyl acetal resin is obtained by acetalizing polyvinyl alcohol with an aldehyde and, if necessary, reacting it with a modifying agent. In addition, to obtain the modified polyvinyl acetal resin, modified polyvinyl alcohol may be used as the raw material polyvinyl alcohol.

[0045] <Degree of Acetalization> The degree of acetalization of the polyvinyl acetal resin used as the thermoplastic resin of the thermoplastic resin composition is preferably 65 mol% or more and 75 mol% or less. When the degree of acetalization of the polyvinyl acetal resin is 65 mol% or more, the number of hydroxyl groups in the polyvinyl acetal resin is reduced, and the adhesive film has sufficient flexibility. When the degree of acetalization of the polyvinyl acetal resin is 75 mol% or less, the adhesion to transparent substrates such as glass is improved. From this viewpoint, the degree of acetalization of the polyvinyl acetal resin is more preferably 67 mol or more and 74 mol or less, even more preferably 68 mol or more and 73 mol or less, and even more preferably 69 mol or more and 72 mol or less. Note that the degree of acetalization means the degree of butyralization when the acetal group is a butyral group and the polyvinyl acetal resin is a polyvinyl butyral resin.

[0046] The degree of acetalization is a molar fraction obtained by subtracting the amount of ethylene groups having hydroxyl groups and the amount of ethylene groups having acetyl groups from the total amount of ethylene groups in the main chain, and dividing the result by the total amount of ethylene groups in the main chain, and the percentage is expressed as the molar fraction. The degree of acetalization (degree of butyralization) may be calculated from the results of measurements made, for example, according to JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0047] <Weight Average Molecular Weight> The weight average molecular weight (Mw) of the polyvinyl acetal resin used as the thermoplastic resin of the thermoplastic resin composition is preferably 220,000 or more. When the weight average molecular weight (Mw) of the polyvinyl acetal resin is 220,000 or more, the impact resistance of the polyvinyl acetal resin can be improved. From this perspective, the weight average molecular weight (Mw) of the polyvinyl acetal resin used as the thermoplastic resin of the thermoplastic resin composition is more preferably 230,000 or more, even more preferably 240,000 or more, and even more preferably 260,000 or more. Furthermore, the weight average molecular weight (Mw) of the polyvinyl acetal resin used as the thermoplastic resin of the thermoplastic resin composition is preferably 310,000 or less. When the weight average molecular weight (Mw) of the polyvinyl acetal resin is 310,000 or less, the adhesive film has sufficient flexibility. Furthermore, it becomes easier to adjust the cohesive failure strength value within the numerical range, and glass shattering can be more effectively suppressed. From this perspective, the weight average molecular weight (Mw) of the polyvinyl acetal resin used as the thermoplastic resin of the thermoplastic resin composition is more preferably 305,000 or less, even more preferably 300,000 or less, and even more preferably 290,000 or less. The weight average molecular weight (Mw) of the polyvinyl acetal resin is measured by gel permeation chromatography. The weight average molecular weight can be measured by the following measurement method. A measurement sample is dissolved to a concentration of 0.05% by mass in an N-methyl-2-pyrrolidone solution to which lithium bromide has been added so that the concentration becomes 10 mM, and the solution is filtered using a syringe filter (Millex-LH 0.45 μm, manufactured by Merck). After filtration, measurement is performed using gel permeation chromatography (e2690, manufactured by Waters), and the molecular weight is calculated using a molecular weight calibration curve prepared using monodisperse polystyrene standard samples. The column used is Shodex GPC KF-806L (Showa Denko KK), and the eluent used is an N-methyl-2-pyrrolidone solution containing lithium bromide added to a concentration of 10 mM.

[0048] <Aldehyde> The polyvinyl acetal resin used as the thermoplastic resin in the thermoplastic resin composition is preferably a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol (PVA) with an aldehyde. The aldehyde is not particularly limited, but generally, an aldehyde having 1 to 10 carbon atoms is preferably used. The aldehyde having 1 to 10 carbon atoms is not particularly limited, and examples thereof include n-butyl aldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexyl aldehyde, n-octyl aldehyde, n-nonyl aldehyde, n-decyl aldehyde, formaldehyde, acetaldehyde, and benzaldehyde. These aldehydes may be used alone or in combination of two or more. Among the above, n-butylaldehyde, n-hexylaldehyde, and n-valeraldehyde are preferred, and n-butylaldehyde is more preferred. Therefore, the polyvinyl acetal resin is preferably polyvinyl butyral resin (PVB).

[0049] <Polyvinyl Alcohol (PVA)> Polyvinyl alcohol (PVA), used as a raw material for polyvinyl acetal resins, is obtained, for example, by saponifying a polyvinyl ester such as polyvinyl acetate. The degree of saponification of polyvinyl alcohol is generally 70 to 99.9 mol%. The average degree of polymerization of PVA is preferably 200 or more, more preferably 500 or more, even more preferably 1000 or more, and even more preferably 1500 or more. When the average degree of polymerization is above the lower limit, the penetration resistance of laminated glass is improved when used in laminated glass. Furthermore, the average degree of polymerization of PVA is preferably 5000 or less, more preferably 4000 or less, even more preferably 3500 or less, and even more preferably 2500 or less. The average degree of polymerization of polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Test Method for Polyvinyl Alcohol." Furthermore, when two or more types of polyvinyl alcohol are used as raw materials, the average degree of polymerization of the polyvinyl alcohol can be estimated by calculation from the average degrees of polymerization of each polyvinyl alcohol.

[0050] Two or more polyvinyl alcohols having different average degrees of polymerization may be used as the polyvinyl alcohol raw material for the polyvinyl acetal resin. In this case, it is preferable to produce the polyvinyl acetal resin using a mixture of two or more polyvinyl alcohols as the raw material by the production method described below. When two or more polyvinyl alcohols are used, it is preferable to use, for example, a first polyvinyl alcohol having an average degree of polymerization of 1500 or more and a second polyvinyl alcohol having an average degree of polymerization of 1000 or less. By using two or more polyvinyl alcohols having different average degrees of polymerization, the flexibility of the adhesive film can be improved. The average degree of polymerization of the first polyvinyl alcohol is preferably 1500 or more and 3500 or less, more preferably 1600 or more and 2500 or less, and even more preferably 1600 or more and 2000 or less. The average degree of polymerization of the second polyvinyl alcohol is preferably 200 or more and 1000 or less, more preferably 300 or more and 900 or less, and even more preferably 400 or more and 700 or less. When the first and second polyvinyl alcohols are used, the blending ratio of the first polyvinyl alcohol to the second polyvinyl alcohol is not particularly limited, but the blending amount of the second polyvinyl alcohol relative to the total amount of the first and second polyvinyl alcohols is preferably 1% by mass or more and 50% by mass or less, more preferably 2% by mass or more and 40% by mass or less, even more preferably 3% by mass or more and 30% by mass or less, and still more preferably 5% by mass or more and 15% by mass or less.

[0051] <Hydroxyl Group Amount> The hydroxyl group amount of the polyvinyl acetal resin used as the thermoplastic resin of the thermoplastic resin composition is preferably 15 mol% or more, and preferably 38 mol% or less. By setting the hydroxyl group amount to 15 mol% or more, adhesion to a transparent substrate is likely to be good. Furthermore, by setting the hydroxyl group amount to 38 mol% or less, flexibility is easily ensured, and the impact energy absorbency of the thermoplastic resin composition can be further improved. The hydroxyl group amount is more preferably 20 mol% or more, and even more preferably 25 mol% or more. Furthermore, the hydroxyl group amount is more preferably 35% or less, and even more preferably 33 mol% or less. When a polyvinyl butyral resin is used as the polyvinyl acetal resin, from the same viewpoint, the hydroxyl group amount is 15 mol% or more, and preferably 38 mol% or less, more preferably 20 mol% or more, even more preferably 25 mol% or more, more preferably 35% or less, and even more preferably 33 mol% or less. The amount of hydroxyl groups in the polyvinyl acetal resin is the molar fraction calculated by dividing the amount of ethylene groups having hydroxyl groups by the total amount of ethylene groups in the main chain, and is expressed as a percentage. The amount of ethylene groups having hydroxyl groups can be measured, for example, in accordance with JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0052] <Degree of Acetylation> The degree of acetylation of the polyvinyl acetal resin used as the thermoplastic resin of the thermoplastic resin composition is preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 10 mol% or less, and even more preferably 2 mol% or less. When the degree of acetylation is below the upper limit, the moisture resistance of the thermoplastic resin composition is improved. Furthermore, the degree of acetylation is not particularly limited, but is preferably 0.01 mol% or more, more preferably 0.1 mol% or more. The degree of acetylation is a molar fraction calculated by dividing the amount of ethylene groups to which acetyl groups are bonded by the total amount of ethylene groups in the main chain, expressed as a percentage. The amount of ethylene groups to which acetyl groups are bonded can be measured, for example, in accordance with JIS K6728 "Test Methods for Polyvinyl Butyral."

[0053] <Modified Polyvinyl Acetal Resin> The polyvinyl acetal resin used as the thermoplastic resin in the thermoplastic resin composition may be an unmodified polyvinyl acetal resin, but may also be a modified polyvinyl acetal resin. The modified polyvinyl acetal resin has a structure (modifying group) other than an acetal group, a hydroxyl group, and an acetyl group, and preferably has a modifying group on the side chain. Examples of the modifying group include those having a polyalkylene oxide structure on the side chain, and those having an acetal group or an alkyl group other than an acetyl group (e.g., having about 2 to 30 carbon atoms) on the side chain. A preferred modified polyvinyl acetal resin is a polyalkylene oxide-modified polyvinyl acetal resin, and a more preferred modified polyvinyl acetal resin is a polyethylene oxide-modified polyvinyl acetal resin. The modification amount is not particularly limited, but is, for example, about 0.1 mol % to 10 mol %. The modification amount refers to the ratio of functional groups to all vinyl monomer units constituting the polyvinyl acetal resin.

[0054] (Method for Producing Polyvinyl Acetal Resin) The polyvinyl acetal resin is preferably produced by a production method including a mixing step of mixing the polyvinyl alcohol and the aldehyde, and an aging step of aging the mixture obtained in the mixing step.

[0055] In the mixing step, polyvinyl alcohol and aldehyde may be mixed according to a conventional method. In addition to polyvinyl alcohol and aldehyde, a catalyst such as an acid catalyst may be added to promote the acetalization reaction. For example, the aldehyde may be added to a mixture of polyvinyl alcohol and an acid catalyst at a low temperature of about 0 to 40°C. A solvent such as water is also typically added. When two or more polyvinyl alcohols are used in combination (for example, when two or more polyvinyl alcohols with different molecular weights are used), the two or more polyvinyl alcohols may be mixed with the aldehyde.

[0056] The aging step is not particularly limited, but may involve, for example, adding a catalyst such as an acid catalyst to the mixture (reaction mixture) obtained by the mixing step, heating to the aging temperature, and maintaining the mixture at the aging temperature for a certain period of time. In this production method, acetalization of polyvinyl alcohol proceeds in the mixing step and the aging step to obtain a polyvinyl acetal resin. After maintaining the reaction mixture at the aging temperature for a certain period of time, the reaction mixture may be appropriately cooled and neutralized, and then washed with water, dried, or the like, as necessary.

[0057] Examples of the acid catalyst added in the mixing step and the aging step include inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, etc. In the aging step, the concentration of the acid catalyst may be adjusted to, for example, about 0.5% by mass or more and 5% by mass or less, preferably about 1% by mass or more and 2.5% by mass or less.

[0058] The aging temperature in the aging step may be relatively low, for example, from 30° C. to 68° C., preferably from 30° C. to 65° C., more preferably from 35° C. to 60° C., and even more preferably from 40° C. to 58° C. The time for which the aging temperature is maintained (aging time) may be longer than a certain time, for example, from 75 minutes to 180 minutes, preferably from 90 minutes to 150 minutes, and more preferably from 100 minutes to 140° C.

[0059] (Ethylene-vinyl acetate copolymer resin (EVA)) The ethylene-vinyl acetate copolymer resin may be a non-crosslinked ethylene-vinyl acetate copolymer resin or a high-temperature crosslinked ethylene-vinyl acetate copolymer resin. Furthermore, the ethylene-vinyl acetate copolymer resin may also be a modified ethylene-vinyl acetate resin such as a saponified ethylene-vinyl acetate copolymer or a hydrolyzed ethylene-vinyl acetate.

[0060] The ethylene-vinyl acetate copolymer resin preferably has a vinyl acetate content of 10% by mass or more and 50% by mass or less, more preferably 20% by mass or more and 40% by mass or less, as measured in accordance with JIS K6730 "Testing Methods for Ethylene-Vinyl Acetate Resins" or JIS K6924-2:1997. By adjusting the vinyl acetate content to be equal to or greater than these lower limits, the adhesion of the laminate to the adherend is enhanced. Furthermore, by adjusting the vinyl acetate content to be equal to or less than these upper limits, the breaking strength of the adhesive film is enhanced.

[0061] (Plasticizer) The thermoplastic resin composition preferably contains a plasticizer in addition to the thermoplastic resin. By containing a plasticizer in the thermoplastic resin composition, the adhesive film becomes more flexible and the impact energy absorbency can be further improved.

[0062] Examples of the plasticizer include organic ester plasticizers, organic phosphorus-based plasticizers such as organic phosphate ester plasticizers and organic phosphite ester plasticizers, organic ether-based plasticizers such as polyalkylene glycol-based plasticizers and polyoxyalkylene ether-based plasticizers, and alcohol-based plasticizers. One type of plasticizer may be used alone, or two or more types may be used in combination. Among the above, organic ester plasticizers and organic ether-based plasticizers are preferred.

[0063] Preferred organic ester plasticizers include monobasic organic acid esters and polybasic organic acid esters. Examples of monobasic organic acid esters include esters of glycols and monobasic organic acids. Examples of glycols include polyalkylene glycols in which each alkylene unit has 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, and the number of repeating alkylene units is 2 to 10, preferably 2 to 4. Examples of glycols include monoalkylene glycols having 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms (i.e., one repeating unit). Specific examples of glycols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, and butylene glycol. Examples of the monobasic organic acid include organic acids having 3 to 10 carbon atoms, and specific examples thereof include butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, n-nonylic acid, and decylic acid.

[0064] Specific monobasic organic acids include triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, and triethylene glycol. Di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprylate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, ethylene glycol di-2-ethylbutyrate, 1,2-propylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, 1,2-butylene glycol di-2-ethylbutyrate, and the like.

[0065] Examples of polybasic organic acid esters include ester compounds of dibasic organic acids having 4 to 12 carbon atoms, such as adipic acid, sebacic acid, and azelaic acid, with alcohols having 4 to 10 carbon atoms. The alcohols having 4 to 10 carbon atoms may be linear, branched, or cyclic. Specific examples include dibutyl sebacate, dioctyl azelaate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, dibutyl carbitol adipate, and mixed adipates. Oil-modified alkyd sebacate is also suitable. Examples of mixed adipates include adipates prepared from two or more alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms.

[0066] The organic ester plasticizer is not limited to the complete esters of the above-mentioned esters, but may also be a partial ester. For example, it may be a partial ester of a glycol and a monobasic organic acid, or a partial ester of a dibasic organic acid and an alcohol. Specific examples include triethylene glycol-mono-2-ethylhexanoate. Furthermore, it may be a partial ester of a monobasic organic acid with a trihydric or higher alcohol, such as glycerin. Examples of monobasic organic acids include monobasic organic acids having 3 to 24 carbon atoms, preferably 6 to 18 carbon atoms. Specific examples of partial esters of a trihydric or higher alcohol and a monobasic organic acid include a mono- or diester of glycerin and stearic acid, and a mono- or diester of glycerin and 2-ethylhexyl acid. Among the organic ester plasticizers listed above, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferred.

[0067] Examples of organic phosphorus-based plasticizers include phosphate esters such as tributoxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate. Examples of polyalkylene glycol-based plasticizers include polyethylene glycol, polypropylene glycol (PPG), poly(ethylene oxide / propylene oxide) block copolymers, poly(ethylene oxide / propylene oxide) random copolymers, and polytetramethylene glycol. Among these, polypropylene glycol (PPG) is preferred.

[0068] The polyoxyalkylene ether plasticizer is an ether compound of a monohydric or polyhydric alcohol and a polyoxyalkylene. Specific examples of the polyoxyalkylene ether plasticizer include polyoxyethylene hexyl ether, polyoxyethylene heptyl ether, polyoxyethylene octyl ether, polyoxyethylene-2-ethylhexyl ether, polyoxyethylene nonyl ether, polyoxyethylene decyl ether, polyoxyethylene allyl ether, polyoxypropylene allyl ether, polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether (DGP), and polyoxyalkylene pentaerythritol ether. Among these, polyoxypropylene diglyceryl ether (DGP) is preferred. The polyoxyalkylene ether plasticizer is preferably an ether compound of a polyhydric alcohol and a polyoxyalkylene, more preferably an ether compound of glycerin or diglycerin and a polyoxyalkylene, and even more preferably an ether compound of glycerin or diglycerin and a polyoxypropylene. Examples of the alcohol plasticizer include various polyhydric alcohols such as butanediol, hexanediol, trimethylolpropane, and pentaerythritol. Among these, trimethylolpropane is preferred.

[0069] The above plasticizers can be used alone or in combination of two or more. Among the above plasticizers, triethylene glycol-di-2-ethylhexanoate (3GO), polyoxypropylene diglyceryl ether (DGP), and polypropylene glycol (PPG) are preferred, with triethylene glycol-di-2-ethylhexanoate (3GO) being more preferred.

[0070] The content of the plasticizer in the thermoplastic resin composition is not particularly limited, but is preferably 20 parts by mass or more and 70 parts by mass or less per 100 parts by mass of the thermoplastic resin. When the content of the plasticizer is 20 parts by mass or more, the adhesive film becomes moderately flexible, and the adhesiveness of the adhesive film improves. Furthermore, the thickness change also becomes easier to increase. On the other hand, when the content of the plasticizer is 70 parts by mass or less, separation of the plasticizer from the adhesive film is prevented. Furthermore, a decrease in the storage modulus and excessive increase in the thickness change can also be prevented. The content of the plasticizer is more preferably 25 parts by mass or more, even more preferably 30 parts by mass or more, and more preferably 65 parts by mass or less, even more preferably 60 parts by mass or less, even more preferably 55 parts by mass or less, and even more preferably 50 parts by mass or less.

[0071] The thermoplastic resin composition may contain, in addition to the plasticizer, known additives that are used in combination with thermoplastic resins. That is, the thermoplastic resin composition may be composed of a thermoplastic resin such as a polyvinyl acetal resin, or a thermoplastic resin and a plasticizer, but may also contain additives other than the plasticizer that are blended as needed. Specific examples of additives other than the plasticizer include ultraviolet absorbers, infrared absorbers, antioxidants, light stabilizers, adhesion modifiers, colorants (pigments or dyes), fluorescent brighteners, and crystal nucleating agents.

[0072] The thickness of the adhesive film is not particularly limited, but is preferably 10 μm or more and 3 mm or less, more preferably 30 μm or more and 2 mm or less, and even more preferably 100 μm or more and 1 mm or less. When the thickness of the adhesive film is equal to or more than the above-mentioned lower limit, the impact resistance can be improved and adhesion to laminated glass members and the like can be easily ensured. On the other hand, when the thickness is equal to or less than the above-mentioned upper limit, the thickness of the laminated glass can be prevented from becoming thicker than necessary.

[0073] As described above, the adhesive film may have an uneven structure. The surface roughness Rz of the release surface of the adhesive film after the release substrate has been peeled off is preferably 3 μm or more and 10 μm or less. When the surface roughness Rz of the release surface of the adhesive film is 3 μm or more, the tackiness is reduced, making it easier to readjust the bonding position after placement on the adherend. When the surface roughness Rz of the release surface of the adhesive film is 10 μm or less, the pressure and temperature of the pre-press when bonding the adhesive film can be reduced. As a result, damage to the adherend and the finished product, such as an image display device, can be reduced. From this perspective, the surface roughness Rz of the release surface of the adhesive film is more preferably 3.5 μm or more and 9.5 μm or less. The surface roughness Rz is the ten-point average roughness (RzJIS94) measured in accordance with JIS B0601-1994. The ten-point mean roughness (RzJIS94) can be measured using, for example, a "Surfcorder SE300" manufactured by Kosaka Laboratory Co., Ltd. More specifically, the ten-point mean roughness (Rz) can be measured using a palpation needle with a tip radius of 2 μm and a tip angle of 60° under the following measurement conditions: a cutoff value of 0.8 mm, a reference length of 0.8 mm, a measurement length of 4 mm, a preliminary length of 0.8 mm, and a palpation needle feed rate of 0.5 mm / sec, under an environment of 23°C and 30% RH. Note that when the surface roughness Rz exceeds 10 μm, the measurement conditions are a cutoff value of 2.5 mm, a reference length of 2.5 mm, a measurement length of 12.5 mm, and a preliminary length of 2.5 mm.

[0074] The adhesive film may have a surface roughness Rz of less than 3 μm on the release surface of the adhesive film after the release substrate has been peeled off. When the surface roughness Rz of the release surface of the adhesive film is less than 3 μm, the adhesive film surface has excellent tackiness. In addition, the pressure, temperature, and time of the pre-press when laminating the adhesive film can be further reduced. As a result, damage to the adherend and the finished product such as an image display device can be reduced. From this perspective, the adhesive film does not need to have a concave-convex structure. Here, "not having a concave-convex structure" means that Rz is 1 μm or less when measured using the above-mentioned surface roughness Rz measurement method, and more preferably Rz is less than 1 μm.

[0075] (Storage modulus at 90°C) The adhesive film has a storage modulus of 1.4 × 10 ５ It is preferable that the storage modulus of the adhesive film is 1.8 × 10 Pa or more. When the storage modulus of the adhesive film is equal to or greater than the lower limit, the adhesive film can have a certain mechanical strength while increasing the amount of thickness change. Therefore, it is possible to further reduce the occurrence of poor appearance or deterioration of appearance while improving the performance of the adhesive film. In addition, since the adhesive film has a certain mechanical strength, it becomes easier to convey the film while applying tension, which makes it easier to mold the adhesive film by, for example, extrusion molding, and improves film formability. From the above viewpoints, the adhesive film has a storage modulus of 1.8 × 10 at 90 ° C. ５ Pa or more, and more preferably 2.0 × 10 ５ Pa or more, and more preferably 2.3 × 10 ５ The storage modulus at 90°C is preferably a certain value or less in order to ensure a certain degree of flexibility, for example, 1.0 × 10 ７ Pa or less, preferably 1.0 × 10 ６ Pa or less, more preferably 5.0 × 10 ５ The storage modulus is a shear storage modulus, and can be measured, for example, under the following measurement conditions.

[0076] The adhesive film is stored for 12 hours in an environment of room temperature 23±2°C and humidity 25±5%, and the viscoelasticity is measured using a dynamic viscoelasticity device (manufactured by TA Instruments, trade name "ARES-G2", jig "8 mm diameter parallel plate") under the following measurement conditions to detect the shear storage modulus (G') at 90°C. (Measurement conditions) Deformation mode: shear mode, measurement temperature: -10°C or higher and 100°C or lower, temperature decrease rate: 3°C / min, measurement frequency: 1 Hz, strain: 1%

[0077] The adhesive film may be a single-layer film having a single layer structure. When the adhesive film is composed of a single layer, the adhesive film of the single layer structure may have the composition as described above for the thermoplastic resin composition. That is, the layer constituting the single-layer adhesive film contains the above-mentioned thermoplastic resin, and may contain a plasticizer as needed, and may also contain additives other than the plasticizer as appropriate.

[0078] The adhesive film may be a multilayer film having two or more layers. Each resin layer of the multilayer film may have the composition as described above for the thermoplastic resin composition. That is, each resin layer contains a thermoplastic resin as described above for the thermoplastic resin composition, and may contain a plasticizer as needed, and additives other than the plasticizer may be appropriately blended. Preferably, each resin layer contains the polyvinyl acetal resin described above as the thermoplastic resin. Details of the thermoplastic resin, plasticizer, and additives in each resin layer of the multilayer film, and details of the content of each component, are as described above for the thermoplastic resin composition. However, the thermoplastic resin used as the basis for the content is the thermoplastic resin contained in each layer. In the multilayer film, each resin layer may have the same composition or different compositions.

[0079] The method for producing the adhesive film is not particularly limited, and it may be produced by a conventionally known method, such as extrusion molding or press molding, but it is preferable to produce it by extrusion molding, as described in detail below.

[0080] <Method for manufacturing a laminate> The method for manufacturing a laminate of the present invention will be described in more detail below using embodiments. <First embodiment> The manufacturing method according to the first embodiment described below obtains a laminate by laminating a first substrate and a second substrate on a resin layer (adhesive film) obtained by extruding a molten thermoplastic resin composition. Note that one of the first substrate and the second substrate corresponds to the first releasable substrate, and the other substrate corresponds to the second releasable substrate. However, in this embodiment, one of the first substrate and the second substrate laminated on the laminate may be peeled off and removed as appropriate, or a laminate may be produced in which a substrate is laminated on only one side of the resin layer (adhesive film).

[0081] The manufacturing method according to the first embodiment is performed using a manufacturing apparatus shown in Fig. 1. The manufacturing apparatus 10 in the first embodiment includes an extruder 11, a mold 12, a feeding mechanism 13, a substrate heating mechanism 14, a laminating mechanism 15, a heating mechanism 16, a cooling mechanism 17, and a winding mechanism 18. In the manufacturing apparatus 10 in this embodiment, a laminate 25 obtained by laminating first and second substrates 21, 22 and a resin layer 20 fed from the feeding mechanism 13 is wound into a roll by the winding mechanism 18 to obtain a roll-shaped laminate.

[0082] In the manufacturing method according to this embodiment, the processes from unwinding the first and second substrates 21, 22 to winding them up by the winding mechanism 18 are carried out between rolls, so-called roll-to-roll. When the substrates, laminates, etc. are transported by roll-to-roll, the substrates and laminates may be transported by, but not particularly limited to, a pinch roll 41 or the like and guided by guide rolls 42, 43, etc. However, the pinch roll 41 and guide rolls 42, 43 shown in FIG. 1 are merely examples and are not particularly limited.

[0083] The extruder 11 is not particularly limited as long as it can melt and knead the thermoplastic resin composition, and may be a single-screw extruder with one screw inside the cylinder, or a twin-screw extruder with two screws in parallel. The thermoplastic resin composition is introduced into the extruder 11 through a raw material supply port on the upstream side of the cylinder, and is melt-kneaded by the screws inside the cylinder while being sent downstream. The melt-kneaded thermoplastic resin composition is supplied to a mold 12 connected to the extruder 11. In the mold 12, the thermoplastic resin composition is extruded from a die provided in the mold 12 into a sheet-like resin layer 20, which is then supplied to a lamination mechanism 15. The temperature at which the thermoplastic resin composition is extruded from the mold 12 (the temperature at the mold outlet) is preferably higher than the softening temperature T1 (°C) described below and at a temperature at which the tan δ of the thermoplastic resin composition is 1 or greater, more preferably at a temperature at which the tan δ is 1.5 or greater. From the viewpoint of suppressing thermal degradation of the thermoplastic resin composition, the temperature is preferably a temperature at which tan δ is 2.2 or less, and more preferably a temperature at which tan δ is 2.0 or less. When the thermoplastic resin composition contains polyvinyl butyral as a main component, the extrusion temperature can be, for example, about 180 to 220°C.

[0084] In the extruder 11, the moisture content of the thermoplastic resin composition may be appropriately adjusted to appropriately adjust the moisture content of the adhesive film to be obtained. The moisture content may be adjusted, for example, by feeding a thermoplastic resin composition whose moisture content has been adjusted in advance into the extruder, or by reducing the moisture content of the thermoplastic resin composition by vacuum suction or the like from a vent of the extruder. Alternatively, the moisture content of the thermoplastic resin composition may be increased by supplying water from the raw material supply port or a moisture supply port provided separately from the raw material supply port.

[0085] In the above description, it is assumed that the thermoplastic resin composition extruded from the mold 12 is a single resin layer, but a co-extrusion method may be employed to extrude multiple resin layers. When multiple resin layers are extruded, multiple extruders may be provided and connected to the mold 12, and the thermoplastic resin composition may be extruded from the mold 12 to form multiple resin layers. In this case, the thermoplastic resin compositions constituting each resin layer may be the same or different.

[0086] The unwinding mechanism 13 includes first and second unwinding mechanisms 31 and 32. A wound body, on which the first substrate 21 and the second substrate 22 are wound in a roll shape, is attached to each of the first and second unwinding mechanisms 31 and 32. The first unwinding mechanism 31 unwinds the first substrate 21 from the wound body and supplies the first substrate 21 to the laminating mechanism 15. The second unwinding mechanism 32 unwinds the second substrate 22 from the wound body and supplies the second substrate 22 to the laminating mechanism 15. Typically, the first and second substrates 21 and 22 are preferably supplied from the unwinding mechanism 13 to the laminating mechanism 15 while being guided by one or more guide rolls (not shown).

[0087] In the unwinding mechanism 13, at least one of the first and second unwinding mechanisms 31 and 32 may be equipped with two or more wound bodies, each of which is formed by winding the first substrate 21 or the second substrate 22 into a roll. At least one of the first and second unwinding mechanisms 31 and 32 may be equipped with a splicer, which connects the substrates between the two or more wound bodies and continuously unwinds the substrate. This configuration enables continuous production without stopping the production line when replacing the wound bodies, thereby improving production efficiency. To further improve production efficiency, the first and second unwinding mechanisms 31 and 32 may each be equipped with two or more wound bodies, and both the first and second unwinding mechanisms 31 and 32 may connect the substrates between the two or more wound bodies and continuously unwind the substrate.

[0088] Furthermore, the first substrate 21 may be subjected to a surface modification treatment, such as plasma modification, surface roughening, or corona treatment, before being laminated on the resin layer 20. Similarly, the second substrate 22 may be subjected to a surface modification treatment, such as plasma modification, surface roughening, or corona treatment, before being laminated on the resin layer 20.

[0089] The plasma modification treatment may be performed on the surfaces of the first and second substrates 21 and 22 that are to be laminated on the resin layer 20. When the plasma modification treatment is performed on the first substrate 21, the second substrate 22, or both, the surfaces are modified to facilitate adhesion to the resin layer 20. For example, oxygen plasma can be used for the plasma treatment. Furthermore, the surface roughening treatment can be performed by roughening the surface of the substrate through skin treatment or the like, thereby adjusting the adhesive strength (peeling strength) of the substrate to the resin layer 20. Furthermore, by roughening the surface of the release substrate, it is also possible to impart the above-mentioned uneven structure to the release substrate.

[0090] The surface modification treatment is not particularly limited, and may be performed, for example, after being fed from the feeding mechanism 13 and before the resin layer 20 is laminated, but is preferably performed after being fed from the feeding mechanism 13 and before being heated by the substrate heating mechanism 14. The surface modification treatment may be performed while being transported roll-to-roll as described above, and for example, the plasma treatment may be performed using a known plasma treatment device. Furthermore, the surface roughening treatment may be performed, for example, by passing the substrate along the surface of a roughened roll.

[0091] In this embodiment, the first and second substrates 21, 22 fed from the first and second feed mechanisms 31, 32, respectively, are preferably heated by the substrate heating mechanism 14 before being supplied to the laminating mechanism 15. Specifically, the first substrate 21 is preferably heated by the substrate heating mechanism 14 (i.e., before laminating the first substrate 21 on the resin layer 20) to a temperature equal to or higher than the softening temperature T1 (°C) of the resin layer 20, which will be described later. By preheating the first substrate 21 to a temperature equal to or higher than the softening temperature T1, the first substrate 21 undergoes thermal shrinkage before being laminated on the resin layer 20. Therefore, when the first substrate 21 is laminated on the extruded resin layer 20, shrinkage of the first substrate 21 due to the heat of the resin layer 20 and the generation of wrinkles can be prevented. Furthermore, the substrate heating mechanism 14 preferably heats the first substrate 21 to approximately ±20°C, and even more preferably to approximately ±15°C, of ​​the temperature R1 of the resin layer 20 when the first substrate 21 is laminated, as described below. The heating time for the first substrate 21 in the substrate heating mechanism 14 is not particularly limited, but is, for example, 0.1 to 30 seconds, preferably 0.1 to 15 seconds. After heating in the substrate heating mechanism 14, the temperature of the first substrate 21 is preferably maintained at or above the softening temperature T1 (°C) before laminating it on the resin layer 20 in the laminating mechanism 15. By laminating in this manner, the first substrate 21 is prevented from shrinking due to heating by the resin layer 20 during lamination, and the occurrence of wrinkles and the like in the first substrate 21 can be further prevented.

[0092] Similarly, the second substrate 22 is preferably heated by the substrate heating mechanism 14 (i.e., before laminating the second substrate 22 on the resin layer 20) to a temperature equal to or higher than the softening temperature T1 (°C) of the resin layer 20, which will be described later. By preheating the second substrate 22 to a temperature equal to or higher than the softening temperature T1, the second substrate 22 will thermally shrink before being laminated on the resin layer 20. This prevents the second substrate 22 from shrinking due to the heat of the resin layer 20 and causing wrinkles when the second substrate 22 is laminated on the extruded resin layer 20. The substrate heating mechanism 14 more preferably heats the second substrate 22 to a temperature approximately ±20°C, and even more preferably to a temperature approximately ±15°C, of ​​the temperature R2 of the resin layer 20 when the second substrate 22 is laminated, which will be described later. The heating time for the second substrate 22 in the substrate heating mechanism 14 is not particularly limited, but is, for example, 0.1 to 30 seconds, preferably 0.1 to 15 seconds. Furthermore, after heating in the substrate heating mechanism 14, it is more preferable that the second substrate 22 be laminated on the resin layer 20 while maintaining the temperature of the second substrate 22 at or above the softening temperature T1 (°C). By laminating in this manner, the second substrate 22 is prevented from shrinking due to heating by the resin layer 20 during lamination, and the occurrence of wrinkles and the like in the second substrate 22 can be further prevented.

[0093] It is particularly preferable that the first and second substrates 21, 22 are both heated to a temperature within the above range before being laminated on the resin layer 20, from the viewpoint of suppressing thermal shrinkage of both the first and second substrates 21, 22 and preventing warping and the like. The first and second substrates 21, 22 may be heated to the same temperature or to different temperatures by the substrate heating mechanism 14. By heating to different temperatures, the adhesive film made of a thermoplastic resin composition and the first substrate 21 and the second substrate 22 can be laminated at different temperatures. As a result, the adhesive strength between the first substrate 21, the second substrate 22 and the adhesive film made of a thermoplastic resin composition can be adjusted.

[0094] The substrate heating mechanism 14 is not particularly limited, and examples thereof include a heating roll and a heating space. The substrate heating mechanism 14 may heat the first and second substrates 21, 22 along any of the paths along which the substrates are supplied from the unwinding mechanism 13 to the laminating mechanism 15. When a heating roll is used, the first substrate 21 may travel along the heating roll along any of the paths. The heating space is a space heated in a high-temperature environment and may be composed of, for example, a thermostatic bath, a heating chamber, a heating furnace, or the like. When a heating space is used, the first substrate 21 may be passed through a heating space adjusted to a high-temperature environment. The second substrate 22 may also be heated in the same manner as the first substrate 21 by a heating space, a heating roll, or the like. The temperature inside the heating space constituting the substrate heating mechanism 14 and the temperature of the surface of the heating roll in contact with the substrates may be appropriately set so that the first and second substrates 21, 22 are within the above-mentioned temperature range. Specifically, the temperature may be set to a temperature equal to or higher than the softening temperature T1 (°C) of the resin layer 20. For convenience, FIG. 1 shows a configuration in which both the first and second substrates 21, 22 are heated by one substrate heating mechanism 14, but two or more substrate heating mechanisms 14 may be provided to heat the first and second substrates 21, 22 independently.

[0095] The laminating mechanism 15 laminates the first and second substrates 21, 22 supplied from the delivery mechanism 13 onto the thermoplastic resin composition (resin layer 20) extruded from the mold 12. The laminating mechanism 15 includes first and second rolls 35, 36, as shown in FIG. 2 , for example. The first roll 35 is a cast roll, and the first and second substrates 21, 22 are laminated onto the resin layer 20 on the first roll 35. The second roll 36 is a nip roll, and is arranged at a fixed interval from the first roll 35. The first substrate 21, resin layer 20, and second substrate 22 supplied between the first roll 35 and the second roll 36 can be pressed together by applying pressure. It is preferable that the pressure applied to the second roll 36 be controllable. By being able to control the pressure applied, it is possible to appropriately control the pressure depending on the types of the first and second substrates 21, 22, the thickness of the resin layer 20, etc. The pressure of the second roll 36 can be adjusted by adjusting the distance from the first roll 35, for example.

[0096] The first and second rolls 35, 36 may both be metal rolls or rubber rolls with rubber wrapped around the periphery of a metal core, but it is preferable to use one as a metal roll and the other as a rubber roll. Using one as a metal roll and the other as a rubber roll eliminates press unevenness and enables the substrates 21, 22 to be stably laminated onto the resin layer 20. Furthermore, the first and second rolls 35, 36 may each have a temperature control mechanism by flowing a fluid such as steam, oil, or water therein, or by introducing a heater or electromagnetic induction. The first and second substrates 21, 22 and the resin layer 20 may be heated by a temperature control mechanism. The temperature control mechanism makes it easier to adjust the temperature during lamination of the first and second substrates 21, 22 and the resin layer 20 within a desired range.

[0097] In this embodiment, as shown in Fig. 2 , the first substrate 21 supplied from the unwinding mechanism 13 is supplied to the first roll 35, transported on and along the first roll 35, and supplied between the first and second rolls 35 and 36. The second substrate 22 supplied from the unwinding mechanism 13 is supplied to the second roll 36, transported on and along the second roll 36, and supplied between the first and second rolls 35 and 36. It is preferable that the first and second rolls 35 and 36 rotate in opposite directions while the first and second substrates 21 and 22 are being supplied.

[0098] On the other hand, the thermoplastic resin composition (resin layer 20) extruded and melted from the mold 12 is supplied between the first and second rolls 35, 36. Then, between the first and second rolls 35, 36, a first substrate 21 and a second substrate 22 are laminated on both sides of the supplied resin layer 20, respectively, to obtain a laminate 25. At this time, the first substrate 21 and the second substrate 22 are simultaneously laminated on the resin layer 20. In this embodiment, by laminating the first and second substrates 21, 22 on both sides of the resin layer 20, respectively, between the first and second rolls 35, 36, the thermal history of the laminate 25 is likely to be the same on the front and back, making it less likely to warp and further improving dimensional stability.

[0099] In this embodiment, the temperature R1 of the resin layer 20 when the first base material 21 is laminated on the resin layer 20 is preferably equal to or higher than the softening temperature T1 (°C) of the resin layer 20. The softening temperature T1 of the resin layer 20 is a temperature that satisfies the following formulas (1) and (2). T1>Tg...Formula (1) tan δ(T1+n)-tan δ(T1+n-1)>0 (n=1 to 5)...Formula (2) Note that Tg in formula (1) is the temperature at the highest maximum value on a tan δ-temperature curve that is created by measuring the tan δ of the resin layer 20, for example, at 0 to 240°C, and plotting tan δ on the vertical axis and temperature on the horizontal axis. Tg is also the glass transition temperature of the resin layer 20. T1 is an integer value and the minimum value that satisfies formulas (1) and (2). Tan δ (T1+n) is the value of tan δ at T1+n (°C). n is an integer of 1 or more and 5 or less, and formula (2) is satisfied when n is any of 1 to 5. Note that tan δ may be measured under the conditions described in the examples below.

[0100] In this embodiment, the first and second base materials 21, 22 are simultaneously laminated on the resin layer 20. Therefore, the temperature R1 of the resin layer 20 when the first base material 21 is laminated on the resin layer 20 is the same as the temperature R2 of the resin layer 20 when the second base material 22 is laminated on the resin layer 20.

[0101] An example of a tan δ-temperature curve is shown in FIG. 3. In the tan δ-temperature curve of the resin layer 20, as shown in FIG. 3, if the temperature is further increased from the temperature (Tg) at which the tan δ-temperature curve reaches its maximum value, tan δ decreases and then increases. The temperature at which the decrease turns to an increase is the softening temperature T1 that satisfies the above formulas (1) and (2). The softening temperature T1 of the resin layer 20 is the temperature at which the resin layer 20 begins to soften. Therefore, if the temperature of the resin layer R1 when the first substrate 21 is laminated is equal to or higher than the softening temperature T1, it becomes possible to laminate the first substrate 21 to the resin layer 20 with an appropriate adhesive strength. Therefore, it is possible to prevent the first substrate 21 from unintentionally peeling off from the resin layer 20 in subsequent processes.

[0102] Furthermore, it is more preferable that the temperature R1 of the resin layer 20 when the first substrate 21 is laminated on the resin layer 20 is equal to or higher than the softening temperature T1 (°C) and a temperature at which tan δ is 0.15 or higher. At a temperature equal to or higher than T1 (°C) and tan δ of 0.15 or higher, the resin layer 20 starts to soften and viscosity becomes more dominant in the resin layer 20. Therefore, by making the temperature R1 higher than this temperature, the first substrate 21 can be more appropriately bonded to the resin layer 20. From the above viewpoints, it is more preferable that the temperature R1 is a temperature that is equal to or higher than the softening temperature T1 of the resin layer 20 and at which tan δ is 0.19 or higher, even more preferable that it is a temperature that is equal to or higher than the softening temperature T1 and at which tan δ is 0.3 or higher, particularly preferable that it is a temperature that is equal to or higher than the softening temperature T1 and at which tan δ is 0.5 or higher, even more preferable that it is a temperature that is equal to or higher than the softening temperature T1 and at which tan δ is 0.75 or higher, and particularly preferable that it is a temperature that is equal to or higher than the softening temperature T1 and at which tan δ is 1 or higher.

[0103] Furthermore, it is more preferable that the temperature R1 of the resin layer 20 when the first substrate 21 is laminated on the resin layer 20 is equal to or higher than the softening temperature T1 (°C) and is at least 50°C higher than the glass transition temperature of the resin layer 20. Even at such a temperature, the resin layer 20 begins to soften and viscosity becomes more dominant in the resin layer 20, so that temperature R1 higher than this temperature allows the first substrate 21 to be more appropriately bonded to the resin layer 20. From the same viewpoint, it is even more preferable that the temperature is equal to or higher than the softening temperature T1 (°C), is at least 50°C higher than the glass transition temperature of the resin layer 20, and is at least a temperature that satisfies the above-mentioned value of tan δ.

[0104] Furthermore, the temperature R1 is not particularly limited, but from the viewpoint of preventing the resin layer 20 from softening or melting more than necessary when the resin layer 20 is laminated to the first substrate 21 and the second substrate 22, it is preferable that the temperature R1 be below a certain level. For example, a temperature that is equal to or higher than the softening temperature T1 and has a tan δ of 2 or less is preferable, and a temperature that is equal to or higher than the softening temperature T1 and has a tan δ of 1.5 or less is more preferable.

[0105] Furthermore, the thermoplastic resin composition extruded from the mold 12 is extruded at a temperature equal to or higher than the softening temperature T1, and the temperature drops after extrusion, but in this embodiment, after the extrusion of the thermoplastic resin composition, before the temperature of the thermoplastic resin composition drops below the softening temperature T1 (°C), it is preferable to laminate the first substrate 21 onto the thermoplastic resin composition (resin layer 20) in the laminating mechanism 15. This allows the thermoplastic resin composition (resin layer 20) to be maintained in a softened state by the residual heat from extrusion while being transferred from the mold 12 to the laminating mechanism 15, without being heated by a separately provided heating means, and to be laminated onto the first substrate 21.

[0106] In the laminating mechanism 15, the laminate 25 obtained by laminating the first and second substrates 21, 22 is sent to the annealing section 16. In the annealing section 16, the laminate 25 is maintained at or above the softening temperature T1 of the thermoplastic resin composition (resin layer 20). By maintaining the laminate 25 at or above the softening temperature T1 in the annealing section 16, stress relaxation is promoted, distortions generated in the resin layer 20 during extrusion are eliminated, and shrinkage of the resin layer 20 due to subsequent cooling or the like can be prevented. The annealing section may be maintained or heated by a heating mechanism, or may be slowly cooled in a room temperature environment, etc. During slow cooling, the laminate 25 may be appropriately transported using guide rolls at room temperature, etc. However, when slowly cooled in the annealing section 16, it is preferable that the laminate 25 be slowly cooled in an environment with a temperature higher than the cooling temperature in the cooling mechanism described below. Note that the laminate 25 is obtained by laminating at least the resin layer 20 on the first and second substrates 21, 22 at or above the softening temperature T1 as described above. Therefore, the laminate 25 (particularly the resin layer 20) may be maintained at or above the softening temperature T1 from the time the laminate 25 is formed in the laminating mechanism 15 until it is supplied to the annealing section 16. According to this embodiment, the resin layer 20 is maintained at a temperature equal to or higher than the softening temperature T1 for a long period of time after the first and second base materials 21, 22 are laminated, which further promotes stress relaxation and further prevents the resin layer 20 from shrinking due to subsequent cooling, etc. However, the temperature of the laminate 25 (particularly the resin layer 20) may be lowered to a temperature below the softening temperature T1 from the time the laminate 25 is formed in the laminating mechanism 15 until it is supplied to the annealing section 16.

[0107] When the annealing section 16 has a heating mechanism, the heating mechanism may be, but is not limited to, a heating roll, a heating space, or the like. When a heating roll is used, the laminate 25 formed in the laminating mechanism 15 may be supplied to the heating roll and advanced along the heating roll. The heating space is a space heated in a high-temperature environment, and may be, for example, a thermostatic bath, a heating chamber, a heating furnace, or the like. When a heating space is used, the laminate 25 may be passed through a heating space adjusted to a high-temperature environment. The temperature inside the space constituting the annealing section 16 and the temperature of the surface of the heating roll in contact with the substrate may be appropriately set so that the laminate is within the above-mentioned temperature range; specifically, the temperature may be set to be equal to or higher than the softening temperature T1 (°C) of the resin layer 20.

[0108] In the annealing section 16, from the viewpoint of appropriately relaxing stress and suppressing shrinkage during cooling by the cooling mechanism 17 described below, the laminate 25 is preferably maintained at or elevated in temperature to a temperature range equal to or higher than the softening temperature T1 of the resin layer 20 and equal to or lower than 1, and even more preferably maintained at or elevated in temperature to a temperature range equal to or higher than the softening temperature T1 and equal to or lower than 0.75. Specifically, for example, when the resin layer 20 is primarily composed of polyvinyl butyral, the temperature can be approximately 60 to 160°C. The time during which the laminate 25 is maintained at or higher than the softening temperature T1 (°C) in the annealing section 16 is not particularly limited, but is, for example, 0.1 to 360 seconds, preferably 3 to 120 seconds.

[0109] The laminate 25, which has been maintained or heated to or above the melting temperature T1 in the annealing section 16, is then sent to the cooling mechanism 17, where the laminate 25 is cooled. By cooling the laminate 25 in the cooling mechanism 17, distortion is less likely to occur during subsequent winding, and the dimensional stability of the resin layer 20 and the laminate 25 can be further improved. Note that, because the resin layer 20 is supported by the substrate during cooling in the cooling mechanism 17, shrinkage during cooling is appropriately suppressed. In particular, in this embodiment, because the substrates 21 and 22 are laminated on both sides of the resin layer 20, shrinkage can be further appropriately suppressed, and dimensional stability can be improved.

[0110] Here, from the viewpoint of making the laminate 25 less likely to be distorted in the subsequent steps, it is preferable that the laminate 25 be cooled in the cooling mechanism 17 to a temperature below the softening temperature T1 (°C) of the resin layer 20, more preferably below the glass transition temperature of the resin layer 20, even more preferably to a temperature that is 10°C or more lower than the glass transition temperature, and even more preferably to a temperature that is 20°C or more lower than the glass transition temperature. The laminate 25 may be cooled in the cooling mechanism 17 to a temperature of about room temperature (e.g., 23°C).

[0111] The cooling mechanism 17 is not particularly limited, but examples include a cooling roll and a cooling space. When a cooling roll is used, cooling is performed by moving the laminate 25 along the cooling roll after heating by the heating mechanism 16. The cooling space is a space maintained in a low-temperature environment, and may be a space or device that maintains a temperature below that of the laminate 25 passing through, such as a thermostatic bath, an air-cooled bath, a cooling chamber, or a room temperature environment. When a cooling space is used, the laminate 25 is simply passed through a cooling space adjusted to a low-temperature environment. The temperature inside the cooling space constituting the cooling mechanism 17 and the temperature of the surface of the cooling roll with which the laminate comes into contact may be appropriately set so that the laminate 25 is within the above-mentioned temperature range, for example, 0°C or higher and lower than the softening temperature T1 (°C), preferably 5°C or higher and 25°C or lower. The cooling time for the laminate 25 in the cooling mechanism 17 at these temperatures is not particularly limited, but may be, for example, 0.1 to 120 seconds, preferably 0.1 to 60 seconds.

[0112] The laminate 25 cooled in the cooling mechanism 17 is wound into a roll by the winding mechanism 18, thereby obtaining a roll-shaped laminate. The winding mechanism 18 is not particularly limited, and a known winding machine may be used.

[0113] In this embodiment, the laminate 25 obtained by the above series of steps suppresses shrinkage of the resin layer 20, and by laminating the first substrate 21 and the second substrate 22, dimensional changes due to residual strain in the resin layer 20 are also suppressed, resulting in a laminate 25 with high dimensional stability. Therefore, as described above, the dimensional change rates of length and thickness can be reduced. Furthermore, in this embodiment, the thermoplastic resin composition (resin layer 20) extruded from the mold 12 is laminated with the first and second substrates 21, 22 before being transported by rolls. Therefore, warping and other problems caused by roll transport are less likely to occur, making it easier to ensure the flatness of the adhesive film.

[0114] The width of the laminate 25 after cutting the edges may be adjusted before being wound by the winding mechanism 18. Furthermore, the laminate 25 may be inspected as appropriate, for example, by measuring the thickness, checking for the presence of foreign matter, measuring foreign matter such as counting the number of foreign matter and measuring its size, measuring transmittance, measuring color, etc. The edge cutting and inspection may be performed after cooling by the cooling mechanism 17 and before winding, but are preferably performed immediately before winding.

[0115] Furthermore, in the above first embodiment, the moisture content of the resin layer 20 is adjusted in an extruder, but the moisture content does not have to be adjusted in an extruder. For example, the moisture content may be adjusted by a humidity control mechanism after cooling by the cooling mechanism 17. The humidity control mechanism is not particularly limited, and examples thereof include a humidity control device that maintains a constant internal humidity. For example, the moisture content of the resin layer 20 may be adjusted by passing the laminate 25 through the humidity control device. However, the humidity control device does not need to be provided separately, and the moisture content of the resin layer 20 may be adjusted by adjusting the humidity of the cooling space that constitutes the cooling mechanism to a constant humidity.

[0116] Second Embodiment In the first embodiment described above, the first and second base materials are laminated in the laminating mechanism, but in the manufacturing apparatus 10B of the second embodiment, only the first base material is laminated in the laminating mechanism. Hereinafter, differences between the second embodiment and the first embodiment will be described with reference to FIG.

[0117] In this embodiment, the unwinding mechanism 13 consists of a first unwinding mechanism 31, and the first substrate 21 unwound from the first unwinding mechanism 31 is heated in the heating mechanism 14 as in the first embodiment and then supplied to the laminating mechanism 15, where the first substrate 21 is laminated onto the resin layer 20.

[0118] As in the first embodiment, lamination of the first substrate 21 onto the resin layer 20 may be performed using a first roll 35 and a second roll 36 as shown in FIG. 5 . That is, the first substrate 21 supplied from the delivery mechanism 13 is supplied to the first roll 35 as shown in FIG. 5 , transported along the first roll 35 on the first roll 35, and supplied between the first and second rolls 35, 36. Note that while the first substrate 21 is being supplied, the first and second rolls 35, 36 may be rotated in opposite directions. Meanwhile, the thermoplastic resin composition (resin layer 20) extruded from the mold 12 and melted is supplied between the first and second rolls 35, 36. Then, between the first and second rolls 35, 36, the first substrate 21 is laminated onto one side of the supplied resin layer 20, thereby obtaining a laminate 25X. In this embodiment, the temperature R1 of the resin layer 20 when the first base material 21 is laminated on the resin layer 20 is as described in the first embodiment.

[0119] Furthermore, the laminate 25X obtained by laminating the first substrate 21 in the laminating mechanism 15 may be sent to the heating mechanism 16, kept warm or heated by the heating mechanism 16, and then cooled by the cooling mechanism 17 before being wound up by the winding mechanism 18, as in the first embodiment. In the second embodiment described above, as in the first embodiment, shrinkage of the resin layer 20 is suppressed, and by laminating the first substrate 21, dimensional changes due to strain remaining in the resin layer 20 are also suppressed, so that a laminate with high dimensional stability can be obtained, and the dimensional change rates of the length and the thickness can be reduced.

[0120] In the first embodiment, a laminate is obtained by laminating a first substrate and a second substrate onto a resin layer obtained by extruding a molten thermoplastic resin composition. In the third embodiment, however, the first and second substrates are laminated onto a resin layer unwound from a roll of a resin layer containing a thermoplastic resin composition. Differences between the first embodiment and the third embodiment will be described below.

[0121] 6, the manufacturing apparatus 10C includes a resin layer payout mechanism 50, a resin layer heating mechanism 51, a payout mechanism 13, a substrate heating mechanism 14, a laminating mechanism 15, an annealing section 16, a cooling mechanism 17, and a winding mechanism 18. In this embodiment, as in the first embodiment, the resin layer 20 (adhesive film) paid out from the resin layer payout mechanism 50 and the first and second substrates 21, 22 paid out from the payout mechanism 13 are laminated and transported as a laminate 25 by the winding mechanism 18 in a so-called roll-to-roll manner until being wound up.

[0122] A wound body 50A in which a resin layer is wound into a roll is attached to the resin layer payout mechanism 50. The wound body 50A may be manufactured by a known method. Specifically, as shown in FIG. 7 , a thermoplastic resin composition is melt-kneaded in an extruder 61, and the melt-kneaded thermoplastic resin composition is supplied to a mold 62 connected to the extruder 61. In the mold 62, the molten thermoplastic resin composition is extruded from a die provided in the mold 62 into a sheet-like resin layer 20. Details of the extruder 61 and the mold 62 are the same as those of the extruder 11 and the mold 12 described above, and as described above, additives may be appropriately blended into the thermoplastic resin composition. The resin layer 20 extruded into a sheet-like form is stretched by a stretching roll 63 consisting of a pair of opposing rolls and supplied into a cooling water tank 64. The resin layer 20 is cooled in the cooling water tank 64 while being guided and conveyed through the cooling water tank 64 by a guide roll 65. The temperature of the cooling water bath 64 is, for example, 0 to 20°C, preferably 0 to 10°C, and the resin layer 20 may be cooled to, for example, about 10 to 50°C. The cooled resin layer 20 is pulled out of the cooling water bath 64 and taken up by the take-up mechanism 66, thereby obtaining a roll-shaped wound body 50A. The resin layer 20 (adhesive film) may be embossed to impart irregularities to its surface before being taken up by the take-up mechanism 66. Examples of embossing that can be used include lip embossing, embossing roll, and calendar roll. By imparting irregularities to the surface of the resin layer 20, it is possible to prevent the resin layer 20 from adhering to itself during take-up.

[0123] As shown in FIG. 6 , in the resin layer payout mechanism 50, the resin layer 20 (adhesive film) is paid out from the wound body 50A, and the paid-out resin layer 20 is supplied to the resin layer heating mechanism 51 and heated by the resin layer heating mechanism 51. In the resin layer heating mechanism 51, the resin layer 20 is heated to a softening temperature T1 or higher, and after heating, is supplied to the laminating mechanism 15. Meanwhile, as in the first embodiment, the first and second substrates 21, 22 are paid out from the payout mechanism 13 and heated by the substrate heating mechanism 14, and the heated first and second substrates 21, 22 are supplied to the laminating mechanism 15. In the laminating mechanism 15, the second substrates 21, 22 are laminated on the resin layer 20 to obtain a laminate 25. Note that in this embodiment, the details of the peelable substrate are the same as those described in the first embodiment above, and therefore will not be described again.

[0124] As in the first embodiment, the laminating mechanism 15 includes first and second rolls 35 and 36 (see FIG. 2 ). As in the first embodiment, the supplied resin layer 20 is supplied between the first and second rolls 35 and 36, and the first substrate 21 and the second substrate 22 are laminated on both sides of the supplied resin layer 20 between the first and second rolls 35 and 36, respectively, to obtain a laminate 25.

[0125] In this embodiment, too, it is preferable that the temperature R1 of the resin layer 20 when the first substrate 21 is laminated onto the resin layer 20 be equal to or higher than the softening temperature T1 (°C) of the resin layer 20, and the details of the temperature R1 are as described in the first embodiment.

[0126] The laminate 25 is sent to the annealing section 16. In the annealing section 16, the laminate 25 may be maintained, kept warm, or heated to a temperature equal to or higher than the softening temperature T1 of the thermoplastic resin composition (resin layer 20). By maintaining, keeping warm, or heating the laminate 25 to a temperature equal to or higher than the softening temperature T1 in the annealing section 16, stress relaxation is promoted, residual strain in the resin layer 20 is removed, and shrinkage of the resin layer 20 due to subsequent cooling or the like can be prevented. The details of the annealing section 16 are the same as those of the first embodiment, and the specific means, the temperature of the laminate 25 in the annealing section 16, the heating time, and the like are the same as those of the first embodiment, so detailed description thereof will be omitted.

[0127] The laminate 25, whose temperature has been raised to or above the melting temperature T1 in the annealing section 16, is then sent to the cooling mechanism 17, where the laminate 25 is cooled. By cooling the laminate 25 in the cooling mechanism 17, distortion is less likely to occur during subsequent transport or winding, and the dimensional stability of the resin layer 20 and the laminate 25 can be further improved. The details of the cooling mechanism 17 are the same as those in the first embodiment, and the specific means, temperature of the laminate 25 in the cooling mechanism 17, cooling temperature, cooling time, etc. are the same as those in the first embodiment, so detailed description thereof will be omitted.

[0128] The laminate 25 cooled in the cooling mechanism 17 is wound into a roll by the winding mechanism 18, thereby obtaining a roll-shaped laminate. The winding mechanism 18 is not particularly limited, and a known winding machine may be used. In this embodiment as well, the laminate 25 obtained by the above series of steps suppresses shrinkage of the resin layer 20, and by laminating the first substrate 21 and the second substrate 22, dimensional changes due to residual strain in the resin layer 20 are also suppressed, thereby obtaining a laminate 25 with high dimensional stability. Therefore, in this embodiment as well, the dimensional change rates of the length and thickness of the laminate can be reduced.

[0129] In this embodiment, too, the width of the cut end may be adjusted before being wound by the winding mechanism 18, and inspection may be performed as appropriate. Furthermore, adjustment of the moisture content may be performed as necessary. In this embodiment, one of the first substrate and the second substrate laminated in the laminate may be peeled off and removed as appropriate, and a laminate may be produced in which the substrate is laminated on only one side of the resin layer (adhesive film).

[0130] <Fourth embodiment> In the third embodiment described above, the first and second base materials are laminated in the laminating mechanism, but in a manufacturing apparatus 10D of a fourth embodiment, only the first base material is laminated in the laminating mechanism. Hereinafter, differences between the fourth embodiment and the first embodiment will be described with reference to FIG.

[0131] In this embodiment, the unwinding mechanism 13 consists of a first unwinding mechanism 31, and the first substrate 21 unwound from the first unwinding mechanism 31 is heated in the heating mechanism 14 as in the third embodiment and then supplied to the laminating mechanism 15, where the first substrate 21 is laminated onto the resin layer 20.

[0132] As in the second embodiment, lamination of the first substrate 21 onto the resin layer 20 may be performed using a first roll 35 and a second roll 36, as shown in Fig. 5. That is, the first substrate 21 supplied from the unwinding mechanism 13 is supplied to the first roll 35, as shown in Fig. 5, transported along the first roll 35 on the first roll 35, and supplied between the first and second rolls 35, 36. Meanwhile, the adhesive film (resin layer 20) unwound from the wound body 50A is heated by a resin layer heating mechanism 51 and then supplied between the first and second rolls 35, 36. Then, between the first and second rolls 35, 36, the first substrate 21 is laminated onto one side of the supplied resin layer 20, thereby obtaining a laminate 25X.

[0133] Furthermore, in the laminating mechanism 15, the laminate 25X obtained by laminating the first base material 21 may be sequentially supplied to the annealing section 16 and the cooling mechanism 17, heated and cooled, and then wound up by the winding mechanism 18, as in the third embodiment. In the fourth embodiment described above, as in the third embodiment, shrinkage of the resin layer 20 is suppressed, and by laminating the first base material 21, dimensional changes due to strain remaining in the resin layer 20 are also suppressed, making it possible to obtain a laminate with high dimensional stability, and to reduce the dimensional change rates of the length and thickness of the laminate.

[0134] Furthermore, in each of the above embodiments, the obtained laminate is wound up by the winding mechanism 18, but the obtained laminate does not need to be wound up by the winding mechanism 18. In this case, the obtained laminate may be cooled by the cooling mechanism 17 and then appropriately cut or punched into sheets.

[0135] Furthermore, the laminating mechanism can take various forms other than those described above. For example, the molten thermoplastic resin composition may be supplied onto the first roll rather than between the first and second rolls, and then laminated on the first roll. The laminating mechanism may also be configured with two pairs of rolls. In this case, after one release substrate is laminated between one pair of rolls, another release substrate may be laminated between another pair of rolls. Furthermore, when one release substrate is laminated on a resin layer, the laminating mechanism may be configured with only one roll. In this case, the molten thermoplastic resin composition may be supplied to the release substrate being transported on the rolls and laminated.

[0136] <Use of Laminate> The laminate of the present invention is not particularly limited, and the adhesive film may be used by being bonded to another adherend. When the laminate of the present invention has first and second release substrates, at least one of the release substrates, preferably at least one release substrate having a lower peel strength than the other release substrate, may be peeled off, and then the adhesive film may be bonded to another adherend. In this case, both release substrates may be peeled off, and then the adhesive film may be bonded to the adherend, or one release substrate may be bonded to the adherend while still laminated on the adhesive film. Similarly, when the laminate of the present invention has a release substrate on only one side, the release substrate may be peeled off, and then the adhesive film may be bonded to the adherend, or the release substrate may be bonded to the adherend while still laminated on the adhesive film. When the release substrate is bonded to the adherend while still laminated on the adhesive film, the release substrate may be peeled off from the adhesive film after the adhesive film has been bonded to the adherend. The dimensional accuracy of the adhesive film of the laminate of the present invention can be further improved by peeling the releasable substrate from the laminate immediately before attaching the laminate to the adherend, or by peeling the releasable substrate from the laminate after attaching the laminate to the adherend.

[0137] The adherend to which the adhesive film is bonded is not particularly limited, but examples thereof include organic material substrates and inorganic material substrates. Examples of organic material substrates include organic resin plates and resin films. Organic resin plates are also called organic glass. Examples of organic glass include, but are not particularly limited to, (meth)acrylic plates such as polycarbonate plates and polymethyl methacrylate plates. The thickness of the organic glass and the inorganic glass described below (collectively sometimes referred to as glass members) is not particularly limited, but is preferably 0.1 mm or more, more preferably 1.0 mm or more, and preferably 5.0 mm or less, more preferably 3.2 mm or less.

[0138] The resin film is not particularly limited, but examples thereof include polyester resin films such as (meth)acrylic resin films, polycarbonate films, polyethylene terephthalate (PET) films, and polyethylene naphthalate (PEN) films; polyolefin resin films such as polyethylene films and polypropylene films; cyclic polyolefin (COP) films, triacetyl cellulose (TAC) films, polyethersulfone (PES) resin films, and polyimide resin films. The surface of the resin film may be provided with a surface layer such as a hard coat layer made of a (meth)acrylic resin or a coating layer containing a heat-shielding substance. The adhesive film of the present invention may also be bonded to an adhesive film made of the above-mentioned thermoplastic resin composition. Therefore, the adhesive film of the present invention may also serve as an adherend. The thickness of the resin film is not particularly limited, but is preferably 30 μm to 2 mm, more preferably 40 μm to 1 mm, and even more preferably 50 μm to 500 μm. In addition, materials that are relatively thick, have low flexibility, and generally cannot be bent are called organic resin plates, while materials that are relatively thin and generally can be bent are generally called resin films, but these are not clearly distinguished from each other.

[0139] Examples of inorganic material substrates include inorganic glass. The inorganic glass is not particularly limited, but examples include various glass plates such as float glass, tempered glass, colored glass, polished glass, patterned glass, wired glass, striped glass, ultraviolet absorbing glass, infrared reflecting glass, infrared absorbing glass, and green glass. The inorganic glass may be subjected to a surface treatment or may be provided with a surface layer such as a coating layer containing a heat-shielding substance.

[0140] The laminate of the present invention may also be used for a functional element. The functional element may be electrically controllable. In this case, the functional element has an electrical circuit, and its operation can be switched by the flow of current or by changing the amount of current flow. Specific examples of electrically controllable functional elements include electrically controllable films and substrates such as electrically controllable flexible printed circuit boards. More specifically, examples include films or flexible printed circuit boards equipped with devices such as dimmers, coils, antennas, piezoelectric elements, LED elements, batteries, sensors such as touch sensors, switches, memories, processors, integrated circuits such as communication ICs, and display elements such as organic EL display elements and liquid crystal display elements. Furthermore, the functional element may be a glass panel in which these devices are mounted on a glass member, an image display panel in which a display element is incorporated into a glass member, or a touch panel in which a touch sensor is incorporated into a resin film or glass member. A preferred functional element is a dimmer element equipped with a dimmer. Examples of the light control element include polymer dispersed liquid crystal (PDLC), electrochromic (EC), suspended particle device (SPD), electrophoretic device, guest host liquid crystal (GHLC), etc. Furthermore, the functional element preferably includes a display element such as an organic EL display element or a liquid crystal display element.

[0141] Examples of electrically controllable films include those comprising at least a substrate film and a device provided on the substrate film, but they may also be those in which a device is disposed between two substrate films. Examples of substrate films include polyester resin films such as polyethylene terephthalate and polyethylene naphthalate, acrylic resin films, cellulose derivative films such as triacetyl cellulose (TAC), polyethersulfone (PES) resin films, and polyimide resin films. Furthermore, in electrically controllable films, an electrode layer may be provided on the device-side surface of the substrate film. Any conventionally known electrode material may be used as the electrode layer without any particular limitation, but a transparent electrode layer is preferred.

[0142] The functional element is preferably a light-controlling film in which the device is a light-controlling body. Examples of light-controlling films include two substrate films and a light-controlling body (light-controlling layer) disposed between the two substrate films. The functional element may not be electrically controlled. Specific examples include a heat-shielding film (heat-absorbing or reflective), a color film, a polarizing plate, an optical compensation plate, or a composite. The thickness of the functional element is not particularly limited, but is, for example, about 20 μm to 2000 μm, preferably about 100 μm to 1000 μm, and more preferably about 200 μm to 800 μm. The thickness of the functional element may vary depending on the position, and in this case, the maximum thickness is meant.

[0143] The laminate of the present invention is preferably used by placing the adhesive film between two members to bond the two members, and more preferably used as an interlayer film for laminated glass by placing the adhesive film between two glass members to bond the two glass members.

[0144] The adhesive film of the present invention is preferably used in an image display device, and is preferably used to bond components constituting the image display device, such as a cover glass, a touch panel, or an image display panel, to each other. For example, when used in an image display device, the adhesive film needs to be attached to the edge of a component such as a cover glass, a touch panel, or an image display panel, so to speak, just edge-on. If the adhesive film protrudes from the edge of each component, that portion needs to be cut off, but cutting off the protruding portion may damage each component. By using the laminate of the present invention, the dimensional accuracy of the adhesive film can be increased, so the adhesive film can be attached to the edge of the glass plate, and there is no need to cut off the portion of the adhesive film protruding from the edge of the glass plate.

[0145] When the laminate of the present invention is used in a functional element, the adhesive film may be used to adhere the functional element to another component. Alternatively, a functional element such as a light control element may be fitted into the frame of an adhesive film formed into a frame shape to fit the functional element, and then the film may be attached to another component such as a resin film. In this case, if there is a gap between the frame of the adhesive film and the functional element, foaming may occur. However, by using the laminate of the present invention, the dimensional accuracy of the adhesive film can be improved, thereby preventing gaps from occurring between the frame of the adhesive film and the functional element.

[0146] Generally, when an adhesive film obtained by extrusion molding is thin, the dimensional stability of the thickness of the adhesive film decreases and warping occurs easily. However, the laminate of the present invention has excellent dimensional stability of the thickness and a small rate of dimensional change in the planar direction (MD or TD), and therefore the laminate of the present invention can be suitably used in applications where a thin adhesive layer is required.

[0147] The laminate of the present invention can be used for a variety of applications, including window glass for various vehicles such as automobiles and trains, ships, and airplanes, various buildings such as buildings, condominiums, detached houses, halls, and gymnasiums, machine tools for cutting and polishing, and construction machines such as shovels and cranes, and partitions inside various vehicles and buildings. Of these, applications in vehicles such as automobiles are preferred, and applications in vehicles such as laminated glass for vehicles, in-vehicle displays, and light-control roofs are more preferred.

[0148] The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The methods for measuring and evaluating the various physical properties in the present invention are as follows.

[0149] <Dimensional Change Rate> According to the method described in the above specification, the dimensional change rates in the MD direction, TD direction, and thickness direction of the laminates and release substrates of the Examples and Comparative Examples before and after the accelerated test were measured. The thickness of the adhesive film was also measured before and after the accelerated test to measure the dimensional change rate of the adhesive film thickness. The thermostatic chamber used was a "PHP-2J" model manufactured by Espec Corporation, and the standing time during measurement was preliminarily measured, with the standing time being 1 minute 30 seconds ± 1 second in the Examples and Comparative Examples.

[0150] <Peel Strength> A 180° peel test was performed in accordance with JIS K6854-2:1999 using an Instron "5965 Model Universal Tester" to measure the peel strength. Specifically, the laminate was cut into a width of 25 mm and a length of 150 mm or more. Then, in the case of a laminate having one releasable substrate, the side of the adhesive film not provided with the releasable substrate was pressure-bonded to a SUS plate via a double-sided adhesive tape (Nitto Denko Corporation, No. 501L) for fixing. At this time, pressure-bonding was performed by rolling twice back and forth with a 2 kg rubber roller. The SUS plate was held with one jig of the universal testing machine and the sample with the other jig, and the 180° peel adhesive strength was measured when peeled at a rate of 100 mm / min at 23 ° C. In the case of a laminate having two releasable substrates, after peeling off one of the releasable substrates, the surface of the adhesive film from which the releasable substrate had been peeled was pressure-bonded to a SUS plate via double-sided adhesive tape (Nitto Denko Corporation, No. 501L). The pressure was applied by rolling the tape back and forth twice with a 2 kg rubber roller. The SUS plate was held in one jig of a universal testing machine, and the sample was held in the other jig. The 180° peel adhesive strength was measured at 23 °C and a speed of 100 mm / min. The peel strength was determined as the arithmetic mean value of the peel strength (N / 25 mm) in the section from 25 mm to 125 mm from the start of the measurement. Peel strength was measured twice for each sample, and the peel strengths obtained in each measurement were further averaged to determine the peel strength of the sample. The double-sided adhesive tape for fixing is not particularly limited as long as it has an adhesive strength higher than the peel strength to be measured and peeling does not occur at the interface between the SUS plate and the double-sided adhesive tape for fixing, and at the interface between the double-sided adhesive tape for fixing and the adhesive film after measurement.

[0151] <Glass Transition Temperature (Tg), Softening Temperature (T1)> The adhesive films obtained in the Examples and Comparative Examples were cut into pieces 10 mm long and 5 mm wide, and viscoelasticity was measured using a dynamic viscoelasticity measuring device (manufactured by TA Instruments, trade name "ARES-G2") under the following measurement conditions. The sample was placed at 200°C, and viscoelasticity measurements were performed while the temperature was lowered, and the peak temperature of the loss tangent tanδ obtained from the results was read. A tanδ-temperature curve was created, and the highest maximum value among the peak temperatures in the temperature range of 0°C to 200°C was taken as the glass transition temperature (Tg), and the temperature satisfying the formulas (1) and (2) described in the specification was taken as the softening temperature T1. (Measurement Conditions) Deformation mode: shear mode, measurement temperature: temperature decrease from 200°C to 0°C, temperature decrease rate: 3°C / min, measurement frequency: 1 Hz, strain: 1%, 8 mm parallel plate

[0152] <Peeling during processing> When the laminates of the examples were produced using the production apparatus shown in Figure 1, the state of the laminate was evaluated according to the following criteria in the section from the laminating mechanism 15 to the winding mechanism 18, and when the laminate was being wound up by the winding mechanism. A: The laminate could be wound up without the first release substrate or the second release substrate being peeled off from the adhesive film. B: There were locations where the first release substrate or the second release substrate was peeled off from the adhesive film.

[0153] <Dimensional Stability> Samples were prepared by cutting the laminates of the Examples and Comparative Examples to a size of 300 mm x 300 mm. The samples were then left on a PTFE plate for 12 hours under conditions of a temperature of 23°C and a relative humidity of 50%, and the length of each side of the sample was measured. Evaluation was then performed according to the following evaluation criteria: A: The absolute values ​​of the changes in the dimensions of all four sides of the sample were less than 1 mm; B: The largest absolute value of the changes in the dimensions of the four sides of the sample was 1 mm or more and less than 5 mm; C: The largest absolute value of the changes in the dimensions of the four sides of the sample was 5 mm or more.

[0154] <Edge Condition During Glass Lamination> An adhesive film measuring 300 mm x 300 m was cut from the adhesive film obtained in the Examples and Comparative Examples. Two glass plates measuring 300 mm x 300 m were prepared. A laminate was produced by laminating the two glass plates via the cut-out adhesive film so that the four edges of the cut-out adhesive film were aligned with the four edges of the glass plates. The resulting laminate was then placed in a rubber bag and subjected to vacuum suction to remove any air remaining between the glass plates and the adhesive film. The laminate was pre-bonded at approximately 80°C to obtain a pre-pressed laminate. The pre-pressed laminate was then placed in an autoclave and pressed at 140°C and 1.3 MPa to produce a glass-laminated laminate for measurement. The following glass plates were used: Glass plate: Soda lime glass manufactured by Central Glass Co., Ltd., thickness: 2 mm, size: 300 mm x 300 mm. Evaluation was performed according to the following evaluation criteria. A: The edges of all four sides of the adhesive film were aligned with the edges of all four sides of the glass plate. B: The edge of at least one of the four sides of the adhesive film was recessed inward from the edge of the side of the glass plate by a distance of more than 0 mm and less than 0.5 mm. C: The edge of at least one of the four sides of the adhesive film was recessed inward from the edge of the side of the glass plate by a distance of 5 mm or more and less than 1.0 mm. D: The edge of at least one of the four sides of the adhesive film was recessed inward from the edge of the side of the glass plate by a distance of 1.0 mm or more.

[0155] <Peeling Workability> The laminates of the Examples and Comparative Examples were cut into 100 mm x 100 mm samples. The time required to peel the releasable substrate from the adhesive film was measured. Evaluation was performed according to the following evaluation criteria. In Example 5, the time required to peel the first releasable substrate was measured. A: Peeling was possible within 10 seconds. B: Peeling was possible in more than 10 seconds but not more than 30 seconds. C: It took more than 30 seconds but not more than 1 minute. D: It took more than 1 minute.

[0156] <Glass Reworkability> The laminates of the Examples and Comparative Examples were cut to a width of 25 mm and a length of 150 mm. Then, the adhesive film surface opposite the surface in contact with the first release substrate (if a second release substrate was present, the second release substrate was peeled off, and the surface of the adhesive film from which the second release substrate had been peeled off) was pressed against a glass plate. A release tape measuring 25 mm in width and 30 mm in length was then attached to an end region of the first release substrate. The release tape attached to the first release substrate was grasped to peel the laminate from the glass plate. This operation was performed twice. The reworkability of the laminate was evaluated according to the following criteria: A: In both attempts, the laminate could be peeled from the glass plate without the first release substrate peeling off from the adhesive film. B: In one of the two attempts to peel the first release substrate, the laminate could be peeled from the glass plate without the first release substrate peeling off from the adhesive film. However, in the other case, when the laminate was peeled from the glass plate, the first releasable substrate peeled from the adhesive film. C: In both cases, when the laminate was peeled from the glass plate, the first releasable substrate peeled from the adhesive film.

[0157] <Separation Test> The laminate of Example 5 having release substrates on both sides was evaluated for the occurrence of unintended peeling when peeling off the release substrates. A sample was prepared by cutting out a piece measuring 100 mm x 100 mm. Then, the release substrate with the lower peel strength between the release substrate and the adhesive film layer was peeled off. After peeling, the other release substrate was observed and evaluated according to the following criteria. A: No unintended peeling or lifting occurred on the other release substrate. B: Peeling or lifting occurred.

[0158] The thermoplastic resins used in the examples and comparative examples were prepared as follows. (Resin) 1800 ml of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, degree of saponification 99 mol%) were placed in a reactor equipped with a stirrer, and the mixture was heated and dissolved while stirring to obtain a polyvinyl alcohol solution. Next, 30% hydrochloric acid was added as a catalyst to this solution so that the hydrochloric acid concentration was 0.2% by mass. The temperature was then adjusted to 15°C, and n-butylaldehyde was added to 10 mol% while stirring. Subsequently, n-butylaldehyde was added to 60 mol%, resulting in the precipitation of a white particulate polyvinyl butyral resin. Ten minutes after precipitation, 30% hydrochloric acid was added so that the hydrochloric acid concentration was 1.8% by mass. The temperature was then raised to 53°C, and the mixture was aged at this aging temperature for 2 hours. Next, the solution was cooled and neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain Resin 1 (polyvinyl butyral resin, hydroxyl group content 30.3 mol%, acetalization degree 68.5 mol%, acetylation degree 1.2 mol%).

[0159] The release substrates used in the Examples and Comparative Examples were as follows: Release substrate (1) (substrate 1): PET (polyethylene terephthalate) film, manufactured by Toray Industries, Inc., trade name "Lumirror", thickness 75 μm, grade: T60 Release substrate (2) (substrate 2): PET (polyethylene terephthalate) film, manufactured by Toray Industries, Inc., trade name "Lumirror", thickness 50 μm, grade: S10, with embossing formed Release substrate (3) (substrate 3): PET (polyethylene terephthalate) film, manufactured by Toray Industries, Inc., trade name "Lumirror", thickness 50 μm, grade: S10, with embossing formed, with concaves and convexes formed to about half the depth of release substrate (2) Release substrate (4) (substrate 4): a urethane-based adhesion modifier was applied to the surface of substrate 1, thereby forming an adhesion adjustment layer on the surface of substrate 1 Release substrate (5) (substrate 5): a silicone-based release agent was applied to the surface of substrate 1, thereby forming an adhesion adjustment layer on the surface of substrate 1

[0160] Example 1 A laminate was produced using the production apparatus 10 shown in FIG. 1. Specifically, 100 parts by mass of resin and 35 parts by mass of plasticizer (triethylene glycol-di-2-ethylhexanoate: 3GO) were supplied to an extruder 11 and melt-kneaded to produce a resin composition, and the resin composition was extruded from a mold 12 at 211 ° C. Meanwhile, first and second substrates 21, 22 were fed from first and second feeding mechanisms 31, 32, and each substrate 21, 22 was heated to 120 ° C. by a substrate heating mechanism 14 consisting of a heating roll. In Example 1, a release substrate (1) (first release substrate) was used as the first substrate 21, and a release substrate (5) (second release substrate) was used as the second substrate 22. The extruded resin composition (resin layer 20) was sandwiched between two heated releasable substrates 21 and 22 using the method shown in FIG. 2 to produce a laminated sheet having a resin layer thickness of 760 μm. The temperatures R1 and R2 of the resin layer 20 when laminating the first and second substrates 21 and 22 were 125°C. The laminated sheet was then heated at 100°C for 5 seconds in an annealing section 16 consisting of a heating roll. It was then cooled at 20°C for 5 seconds in a cooling mechanism 17 consisting of a cooling roll, and then air-cooled at room temperature for 20 seconds. The second releasable substrate 22 was then peeled off to produce the laminate of Example 1. The glass transition temperature (Tg) of the resin composition (resin layer) was 33°C, and the storage modulus at 90°C was 2.1 × 10 ５ The softening temperature T1 of the resin layer was 63° C., the glass transition temperature was 33° C., and tan δ at each temperature was the value shown in Table 1.

[0161]

[0162] (Example 2) A releasable substrate (2) was used as both the first and second releasable substrates, and the temperatures R1 and R2 of the resin layer 20 when the first and second substrates 21 and 22 were laminated were set to 117°C. When the releasable substrate (2) was laminated, the embossment on the releasable substrate (2) was transferred to form an embossment on the resin layer. Otherwise, the laminate of Example 2 was produced in the same manner as in Example 1.

[0163] (Example 3) The release substrate (3) was used as both the first and second release substrates. The thickness of the resin layer in the laminated sheet was 380 μm. The substrate heating mechanism 14 consisting of a heating roll was not used, and the release substrate was not preheated before lamination with the resin layer. In addition, the temperatures R1 and R2 of the resin layer 20 when laminating the first and second substrates 21 and 22 were 80 ° C. When the release substrate (3) was laminated, the embossment on the release substrate (3) was transferred to form an embossment on the resin layer. Otherwise, the laminate of Example 3 was produced in the same manner as Example 1.

[0164] Example 4 A resin composition extruded in the same manner as in Example 1, except that the thickness of the resin film was 380 μm, was immersed in a water tank and cooled as shown in FIG. 7 to obtain a resin film. The resin film was then subjected to the following embossing process. The obtained resin film was wound into a wound body. A laminate was then laminated using the manufacturing apparatus shown in FIG. 6. Specifically, a resin layer (adhesive film) was unwound from the wound body in a room temperature environment and heated at 80°C for 5 seconds using a heating roll in the resin layer heating mechanism 51. Furthermore, two substrates 21 and 22 were unwound from the first and second unwound mechanisms 31 and 32, and each substrate 21 and 22 was heated to 80°C using a substrate heating mechanism 14 consisting of a heating roll. A releasable substrate 4 was used as the first substrate, and a releasable substrate 5 was used as the second substrate. Next, the unwound adhesive film was sandwiched between two releasable substrates 21 and 22 heated to 90°C using the method shown in Figure 2 to produce a laminate sheet with a resin layer thickness of 380 μm. The laminate was then slowly cooled to room temperature in an air-cooled bath. After slow cooling, the second substrate was peeled off to produce the laminate of Example 4. [Embossing] Random irregularities were formed on the surface of an iron roll using a blasting agent, and the iron roll was then vertically ground. Further, finer blasting agents were used to create fine irregularities on the flat surface after grinding, thereby obtaining a pair of rolls with the same shape, each having a coarse main embossment and a fine sub-embossment. The pair of rolls was used as a texture transfer device, and the random texture was transferred to both sides of the resulting resin film. The transfer conditions were a resin film temperature of 80°C, a roll temperature of 145°C, a linear speed of 10 m / min, and a press linear pressure of 50 to 100 kN / m.

[0165] (Example 5) A releasable substrate (5) was used as the first substrate instead of the releasable substrate (1). The first substrate 21 was heated to 100°C by a substrate heating mechanism 14 consisting of a heating roll, and the second substrate was heated to 120°C. In addition, temperatures R1 and R2 were set to 104°C, and the thickness of the resin layer in the laminate sheet was set to 200 μm. The releasable substrate was not peeled from the laminate sheet. Otherwise, the laminate of Example 5 was produced in the same manner as in Example 1.

[0166] (Example 6) The thickness of the resin layer in the laminate sheet was set to 200 μm. The temperatures R1 and R2 of the resin layer 20 when laminating the first and second base materials 21 and 22 were set to 103° C. Otherwise, the laminate of Example 6 was produced in the same manner as Example 1.

[0167] (Example 7) A releasable substrate (5) was used as the first substrate instead of the releasable substrate (1). The thickness of the resin layer in the laminate sheet was set to 100 μm. The temperatures R1 and R2 of the resin layer 20 when laminating the first and second substrates 21 and 22 were set to 82° C. Otherwise, a laminate of Example 7 was produced in the same manner as in Example 1.

[0168] (Example 8) The release substrate (2) was used as the first and second release substrates. The thickness of the resin layer in the laminated sheet was 50 μm. The substrate heating mechanism 14 consisting of a heating roll was set to room temperature. The temperatures R1 and R2 of the resin layer 20 when laminating the first and second substrates 21 and 22 were set to 109°C. The embossment on the release substrate was transferred during lamination to form an embossment on the thermoplastic resin layer. Otherwise, the laminate of Example 8 was produced in the same manner as in Example 1.

[0169] (Example 9) A release substrate (5) was used as the first substrate instead of the release substrate 1. The thickness of the resin layer in the laminate sheet was set to 10 μm. The temperatures R1 and R2 of the resin layer 20 when laminating the first and second substrates 21 and 22 were set to 111° C. Otherwise, a laminate of Example 9 was produced in the same manner as in Example 1.

[0170] Comparative Example 1: 100 parts by mass of resin and 40 parts by mass of plasticizer (triethylene glycol-di-2-ethylhexanoate: 3GO) were fed into an extruder and melt-kneaded at 200°C to produce a resin composition. The resin composition was extruded to obtain a resin film. The resin film was embossed as described below to produce an adhesive film with a thickness of 760 μm. [Embossing] After random irregularities were formed on the surface of an iron roll using a blasting agent, the iron roll was vertically ground, and finer irregularities were further formed on the flat surface after grinding using a finer blasting agent, thereby obtaining a pair of rolls of the same shape having coarse main embossments and fine sub-embossments. The pair of rolls was used as a texture transfer device to transfer random textures to both sides of the resulting resin film. The transfer conditions were as follows: resin film temperature 80° C., roll temperature 145° C., linear speed 10 m / min, and press linear pressure 50 to 100 kN / m.

[0171] Comparative Example 2 An adhesive film of Comparative Example 2 was produced in the same manner as in Comparative Example 1, except that the thickness was changed to 380 μm.

[0172] Comparative Example 3 A resin film of Comparative Example 3 was produced in the same manner as in Comparative Example 1, except that the thickness was changed to 200 μm.

[0173]

[0174] The laminates of Examples 1 to 9 had excellent dimensional stability because they had at least one releasable substrate, whereas the laminates of Comparative Examples 1 to 3 had poor dimensional stability because they did not have a releasable substrate.

[0175] 10, 10B, 10C, 10D Manufacturing apparatus 11, 61 Extruder 12, 62 Mold 13 Payout mechanism 14 Substrate heating mechanism 15 Laminating mechanism 16 Heating mechanism 17 Cooling mechanism 18 Winding mechanism 20 Resin layer 21, 22 Substrate 25, 25X Laminate 41 Pinch roll 42, 43 Guide roll 31 First payout mechanism 32 Second payout mechanism 35 First roll 36 Second roll 50 Resin layer payout mechanism 50A Wound body 51 Resin layer heating mechanism 64 Cooling water tank 65 Guide roll

Claims

1. A laminate comprising at least one releasable substrate and at least one adhesive film made of a thermoplastic resin composition containing a thermoplastic resin.

2. The laminate according to claim 1, wherein the thermoplastic resin is polyvinyl butyral resin (PVB).

3. The laminate according to claim 1, wherein the thermoplastic resin is an ethylene-vinyl acetate copolymer resin (EVA).

4. The laminate according to claim 1, wherein the absolute value of the dimensional change rate in the machine direction (MD) before and after the following accelerated test ((length after test - length before test) ÷ (length before test) x 100) is 1% or less, and the absolute value of the dimensional change rate in the transverse direction (TD) before and after the following accelerated test ((length after test - length before test) ÷ (length before test) x 100) is 1% or less. (Accelerated Test) (1) Samples measuring 20 mm x 100 mm are cut out from the laminate so that the machine direction (MD) and transverse direction (TD) of the laminate coincide with the longitudinal directions of the samples. Then, heat-resistant tape is attached to the samples within 1 mm from the end of the short side. (2) The samples are hung from the heat-resistant tape side in a thermostatic chamber set to conditions of a temperature of 80°C and a humidity of 40% RH, with the long side of the sample aligned vertically, and held for 20 minutes. (3) After 20 minutes have passed since the sample was suspended in the thermostatic bath, the sample was removed from the thermostatic bath.

5. The laminate according to claim 1, wherein the absolute value of the dimensional change rate of thickness before and after the following accelerated test ((thickness after test - thickness before test) ÷ (thickness before test) × 100) is 5% or less. (Accelerated Test) (1) Samples measuring 20 mm × 100 mm are cut out from the laminate so that the length direction (MD) and width direction (TD) of the laminate coincide with the longitudinal direction of the sample. Then, heat-resistant tape is attached to the sample within 1 mm from the end of the short side. (2) The sample is hung from the heat-resistant tape side in a thermostatic chamber set to conditions of a temperature of 80°C and a humidity of 40% RH so that the long side of the sample is vertical, and is kept there for 20 minutes. (3) After 20 minutes have passed since the sample was hung in the thermostatic chamber, the sample is removed from the thermostatic chamber.

6. The laminate according to claim 1, wherein the absolute value of the dimensional change rate of the length in the machine direction (MD) of the release substrate before and after the following accelerated test ((length after test - length before test) ÷ (length before test) x 100) is 0.5% or less, and the absolute value of the dimensional change rate of the length in the cross direction (TD) of the release substrate before and after the following accelerated test ((length after test - length before test) ÷ (length before test) x 100) is 0.5% or less. (Accelerated Test) (1) Samples measuring 20 mm x 100 mm are cut out from the release substrate so that the machine direction (MD) and cross direction (TD) of the release substrate coincide with the longitudinal direction of the sample. Then, heat-resistant tape is attached to the sample within 1 mm from the edge of the short side. (2) The sample is hung from the heat-resistant tape side so that the long side of the sample is vertical in a thermostatic chamber set to a temperature of 80°C and a humidity of 40% RH, and is held for 20 minutes. (3) After 20 minutes have passed since the sample was hung in the thermostatic chamber, the sample is removed from the thermostatic chamber.

7. The laminate according to claim 1, wherein the release substrate is at least one substrate selected from the group consisting of release films, release papers, mesh materials, metals, and prepregs, and the resin constituting the release film is polyester resin, polyolefin resin, polyimide resin, fluororesin such as tetrafluoroethylene, silicone resin, liquid crystal polymer, polysulfone resin, cellulose acetate, polyamide resin, polyether ether ketone resin, polyether ketone ketone resin, modified polyphenylene ether, polyphenylene sulfide resin, polycarbonate resin, or polybenzimidazole resin.

8. The laminate according to claim 1, wherein the thickness of the adhesive film is 10 μm or more and 3 mm or less.

9. The laminate according to claim 1, wherein the thickness of the release substrate is 10 μm or more and 200 μm or less.

10. The laminate according to claim 1, wherein the peel strength when the releasable substrate is peeled from the adhesive film is 0.02 N / 25 mm or more and 7 N / 25 mm or less.

11. A laminate according to claim 1, comprising one releasable substrate and one adhesive film, wherein the peel strength when the releasable substrate is peeled from the adhesive film is 0.03 N / 25 mm or more and 7 N / 25 mm or less.

12. A laminate according to claim 1, having the releasable substrates on both sides of the adhesive film, wherein the releasable substrate on one side of the adhesive film is referred to as a first releasable substrate and the releasable substrate on the other side of the adhesive film is referred to as a second releasable substrate, and wherein the peel strength ratio (B / A) of the peel strength A (N / 25 mm) when the first releasable substrate is peeled from the adhesive film to the peel strength B (N / 25 mm) when the second releasable substrate is peeled from the adhesive film is 1.3 or more.

13. A laminate according to claim 12, wherein the peel strength A when the first releasable substrate is peeled from the adhesive film is 0.03 N / 25 mm or more and 0.5 N / 25 mm or less, and the peel strength B when the second releasable substrate is peeled from the adhesive film is 0.05 N / 25 mm or more and 7 N / 25 mm or less.

14. The laminate of claim 12, wherein the first releasable substrate is thinner than the second releasable substrate.

15. The laminate according to claim 1, wherein the releasable substrate is provided with an adhesion adjusting layer.

16. The laminate according to claim 1, wherein the surface roughness Rz of the release surface of the adhesive film after the release substrate has been peeled off is 3 μm or more and 10 μm or less.

17. The laminate according to claim 1, wherein the surface roughness Rz of the release surface of the adhesive film after the release substrate has been peeled off is less than 3 μm.

18. The laminate according to claim 1, wherein the surface roughness Rz of the release surface of the adhesive film after the release substrate is peeled off is less than 1 μm.

19. The laminate according to claim 1, wherein the thermoplastic resin composition contains 20 to 70 parts by mass of a plasticizer per 100 parts by mass of the thermoplastic resin.

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