Method for bending functional film and method for manufacturing laminated glass

Abstract

To suppress an occurrence of wrinkles and optical distortion.SOLUTION: A method for bending a functional film including a resin film includes: holding a peripheral part of a functional film by a supporting member with a pressure of 30 kPa or more; heating the functional film at a heating temperature higher than a glass transition temperature of the resin film in a state where the peripheral part is held by the supporting member; curving the functional film by pressing a mold having a three-dimensional curved surface that is convex in one direction against one of main surfaces of the functional film, in a state where heating of the functional film at the heating temperature is stopped, and the peripheral part is held by the supporting member; and cooling the functional film to a cooling temperature lower than the glass transition temperature by releasing pressing the mold.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for bending a functional film and a method for manufacturing laminated glass.

Background Art

[0002] Functional films having a predetermined function such as a dimming film are known. Such a functional film may need to be curved, for example, for reasons such as being mounted on a curved laminated glass. For example, Patent Document 1 describes that a dimming film is thermoformed into a three-dimensional shape before manufacturing laminated glass by a vacuum forming method using a vacuum forming apparatus, a hot pressing method using a hot press apparatus, a bag method using a bag apparatus, or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the hot pressing method and the bag method, pressing force is applied to both main surfaces of the dimming film, and the shape of fine foreign matter attached to the mold surface or the bag surface is transferred to the dimming film, which may cause an optical distortion called "bump distortion". Further, in the vacuum forming method, since it is necessary to bring the dimming film into close contact with the forming die by suction of air through the suction holes, it is necessary to prepare a dimming film sufficiently larger than the forming die. Further, wrinkles may occur at positions corresponding to the outer edge of the forming die of the dimming film and outside thereof, and a trimming process for trimming the outer shape was substantially required after the autoclave process for manufacturing laminated glass.

[0005] Therefore, when bending a functional film such as a dimming film, it is required to suppress the occurrence of wrinkles and optical distortion.

[0006] The present disclosure has been made in view of the above, and an object thereof is to provide a method for bending a functional film capable of suppressing the occurrence of wrinkles and optical distortion and a method for manufacturing a laminated glass.

Means for Solving the Problems

[0007] The method for bending a functional film according to the present disclosure is a method for bending a functional film including a resin film, wherein a peripheral portion of the functional film is clamped by a support member at a pressure of 30 kPa or more, and with the peripheral portion clamped by the support member, the functional film is heated at a heating temperature higher than the glass transition temperature of the resin film, heating of the functional film at the heating temperature is stopped, and with the peripheral portion clamped by the support member, a mold having a three-dimensional curved surface convex in one direction is pressed against one main surface of the functional film to bend the functional film, and pressing of the mold is released and the functional film is cooled to a cooling temperature lower than the glass transition temperature.

[0008] The method for manufacturing a laminated glass according to the present disclosure includes obtaining a laminate by laminating a first glass plate having a curved shape, a first intermediate layer, the functional film obtained by the bending method, a second intermediate layer, and a second glass plate having a curved shape in this order, and heating the laminate at an adhesion temperature to adhere the respective layers of the laminate to obtain a laminated glass, wherein the adhesion temperature is higher than the glass transition temperature and lower than the heating temperature.

Effects of the Invention

[0009] According to the present disclosure, the occurrence of wrinkles and optical distortion can be suppressed.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

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Figure 5

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Figure 10

Figure 11

Figure 12

DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the present disclosure is not limited by this embodiment, and when there are a plurality of embodiments, those configured by combining each embodiment are also included.

[0012] (Bending of the functional film) In the present embodiment, the functional film 10 is bent to manufacture a curved functional film 10. FIG. 1 is a flowchart showing a method for bending the functional film according to the present embodiment.

[0013] (Preparation of Functional Film) As shown in FIG. 1, in this forming method, a functional film 10 to be bend-formed is prepared (step S10).

[0014] The functional film 10 is a film including a resin film. The resin film may be a film containing any resin, and examples thereof include films containing at least one of polyethylene terephthalate (PET), cycloolefin polymer (COP), polycarbonate (PC), and polystyrene (PS).

[0015] The functional film 10 may be any film including a resin film, but is preferably a film having a predetermined function, and more preferably a film having a predetermined optical function. The functional film 10 preferably includes at least one of, for example, a dimming film, a electrothermal film, a transparent display, a film mounted with a light-emitting element, an infrared cut film, and a radio wave control film. In the example of this embodiment, the functional film 10 is a dimming film. The dimming film refers to a film capable of electrically changing the transmittance of light (for example, visible light) and haze.

[0016] In this embodiment, the functional film 10 to be bend-formed is flat. However, the shape of the functional film 10 to be bend-formed may be arbitrary, and may be, for example, a curved shape. In this case, the functional film 10 will be further curved by the bend-forming.

[0017] (Configuration of Functional Film) Figure 2 is a schematic cross-sectional view of the functional film. The laminated structure of the functional film 10 may be arbitrary, but the functional film 10 as the dimming film according to the present embodiment has a configuration as shown in Figure 2. As shown in Figure 2, in the present embodiment, the functional film 10 has a first base material 12A, a first transparent electrode layer 14A, a dimming layer 16, a second transparent electrode layer 14B, and a second base material 12B. When the lamination direction of each layer of the functional film 10 is the Z direction, the functional film 10 has the first base material 12A, the first transparent electrode layer 14A, the dimming layer 16, the second transparent electrode layer 14B, and the second base material 12B laminated in this order in the Z direction.

[0018] Hereinafter, one direction orthogonal to the Z direction is defined as the X direction, and one direction orthogonal to the X direction and the Z direction is defined as the Y direction. Hereinafter, when the first base material 12A and the second base material 12B are not distinguished, they are referred to as the base material 12, and when the first transparent electrode layer 14A and the second transparent electrode layer 14B are not distinguished, they are referred to as the electrode layer 14. Hereinafter, when the first base material 12A and the second base material 12B are not distinguished, they are referred to as the base material 12, and when the first transparent electrode layer 14A and the second transparent electrode layer 14B are not distinguished, they are referred to as the electrode layer 14.

[0019] The thickness of the functional film 10 is, for example, 0.05 mm or more and 1 mm or less, preferably 0.1 mm or more and 0.8 mm or less, and more preferably 0.2 mm or more and 0.6 mm or less. The thickness here is the distance from the main surface 10A to the main surface 10B in the Z direction.

[0020] The area of the functional film 10 when viewed from the Z direction is, for example, 3.0×10 4 mm 2 or more and 3.0×10 7 mm 2 or less is preferable, and 4.0×10 5 mm2 Above 4.0×10 6 mm 2 Below is more preferable, 1.0×10 6 mm 2 Above 4.0×10 6 mm 2 Below is even more preferable. According to this embodiment, the functional film 10 of such a size can be bent appropriately.

[0021] The first base material 12A and the second base material 12B are a pair of base materials that support the electrode layer 14 and sandwich the light control layer 16. The first base material 12A is arranged in the Z direction relative to the light control layer 16 and supports the first transparent electrode layer 14A. The second base material 12B is arranged in the direction opposite to the Z direction relative to the light control layer 16 and supports the second transparent electrode layer 14B.

[0022] The base material 12 is a resin film included in the functional film 10. The base material 12 is preferably a transparent resin layer. The base material 12 preferably contains one or more selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polyamide, polyether, polysulfone polyethersulfone, polycarbonate, polystyrene, cyclic polyolefin, polyarylate, polyetherimide, polyetheretherketone, polyimide, aramid, polybutylene terephthalate, triacetyl cellulose, polyurethane, cycloolefin polymer.

[0023] Note that the first base material 12A and the second base material 12B are, for example, composed of the same materials as those shown above, but are not limited thereto and may be composed of different materials.

[0024] The thickness of the base material 12 is, for example, 5 μm or more and 500 μm or less, preferably 10 μm or more and 300 μm or less, and more preferably 50 μm or more and 200 μm or less. When the thickness is 5 μm, the decrease in the impact resistance of the functional film 10 is preferably suppressed. When the thickness is 500 μm or less, the functional film 10 can be bent with a small force and a short heating time, and the mass does not become too large. The thickness here is the distance in the Z direction from the main surface on the Z direction side of the base material 12 to the main surface on the opposite side of the Z direction. Note that the first base material 12A and the second base material 12B have the same thickness, but they may have different thicknesses.

[0025] The first transparent electrode layer 14A is formed on the main surface of the first base material 12A in the direction opposite to the Z direction and is in contact with the light control layer 16. The second transparent electrode layer 14B is formed on the main surface in the Z direction of the second base material 12B and is in contact with the light control layer 16. That is, the first transparent electrode layer 14A and the second transparent electrode layer 14B are a pair of electrode layers sandwiching the light control layer 16. The first transparent electrode layer 14A and the second transparent electrode layer 14B are connected to a control unit (not shown) via a power supply unit 17 and wiring 18 described later, and a voltage is applied from the power supply unit 17 under the control of the control unit. The first transparent electrode layer 14A and the second transparent electrode layer 14B are each formed over the entire surfaces of the first base material 12A and the second base material 12B. However, the shapes of the first transparent electrode layer 14A and the second transparent electrode layer 14B may be arbitrary, and they do not have to be formed over the entire surfaces of the first base material 12A and the second base material 12B, and they do not have to be rectangular, and may be, for example, a comb shape.

[0026] As the electrode layer 14, for example, a transparent conductive oxide (TCO) can be used. Examples of TCO include, but are not limited to, tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), and indium-doped cadmium oxide.

[0027] As the electrode layer 14, a transparent conductive polymer such as poly(3,4-ethylenedioxythiophene) (PEDOT) or poly(4,4-dioctylcyclopentadithiophene) can also be preferably used. Further, as the electrode layer 14, a laminated film of a metal phase and a dielectric layer, silver nanowires, a metal mesh of silver or copper, etc. can also be preferably used.

[0028] The dimming layer 16 is a layer capable of changing the light transmittance and haze. The dimming layer 16 is located between the first base material 12A and the second base material 12B. That is, the dimming layer 16 is located between the first transparent electrode layer 14A and the second transparent electrode layer 14B. The dimming layer 16 according to the present embodiment is a polymer dispersed liquid crystal (PDLC). However, the dimming layer 16 is not limited to PDLC, and may be, for example, any of polymer network liquid crystal (PNLC), guest-host liquid crystal (GHLC), suspended particle device (SPD), electrochromic (EC).

[0029] The power supply unit 17 is connected to the electrode layer 14 and applies the voltage from the control unit to the electrode layer 14. The wiring 18 may be integrally formed with the power supply unit 17.

[0030] The material of the power supply unit 17 is not particularly limited as long as it is a conductive material, and examples thereof include metal materials. Examples of the metal material include gold, silver, copper, aluminum, tungsten, platinum, palladium, nickel, cobalt, titanium, iridium, zinc, magnesium, or tin. Further, these metals may be plated, or may be configured as a composite with an alloy or a resin.

[0031] (Clamping of the functional film) As shown in Fig. 1, in this forming method, after preparing the functional film 10 to be bent, the peripheral portion 10D of the functional film 10 is clamped by a support member H (step S12). Figs. 3 and 4 are schematic views showing the state where the functional film is clamped by the support member. Fig. 3 is a cross-sectional view of the state where the functional film is clamped by the support member, and Fig. 4 is a top view of that state.

[0032] The peripheral portion 10D refers to the portion of the entire functional film 10 that is located outside the in-plane direction with respect to the portion including the center of the functional film 10 when viewed from the Z direction. That is, when the portion including the center of the functional film 10 is defined as the central portion 10E when viewed from the Z direction, it can be said that the peripheral portion 10D is the portion surrounding the central portion 10E. Note that the inner side in the in-plane direction is the direction from the end face 10C of the functional film 10 toward the center of the functional film 10 when viewed from the Z direction, and the outer side in the in-plane direction is the direction from the center of the functional film 10 toward the end face 10C of the functional film 10 when viewed from the Z direction.

[0033] The support member H may have any structure capable of clamping the peripheral portion 10D. In this embodiment, it is a member in which a pair of support surfaces HA for clamping the peripheral portion 10D of the functional film 10 are formed. Here, when the region of the main surface 10A of the functional film 10 that overlaps the peripheral portion 10D is defined as region 10DA, and the region of the main surface 10B of the functional film 10 that overlaps the peripheral portion 10D is defined as region 10DB, in this step, one support surface HA of the support member H is brought into contact with region 10DA, and the other support surface HA of the support member H is brought into contact with region 10DB. Then, a load is applied to the support member H with the support surfaces HA in contact with regions 10DA and 10DB in the direction in which one support surface HA and the other support surface HB approach each other, and it is held in that state, so that the peripheral portion 10D is clamped by the support member H. Thereby, the support member H is attached to the functional film 10. Note that the support member H may clamp a plurality of functional films at the same time. Also, the method of applying a load to the support member H may be arbitrary.

[0034] When attaching the support member H to the functional film 10, the environmental temperature is preferably lower than the glass transition temperature of the resin film of the functional film 10. For example, it is more preferably in the same temperature range as the environmental temperature T2 described later.

[0035] The support member H preferably sandwiches only the peripheral edge portion 10D of the entire functional film 10. That is, the support member H preferably sandwiches the peripheral edge portion 10D but does not sandwich the central portion 10E. In other words, in the state where the support member H is attached to the functional film 10, when viewed from the Z direction, it is preferable that the support member H overlaps the peripheral edge portion 10D and does not overlap the central portion 10E.

[0036] The support member H preferably sandwiches the entire circumferential section of the peripheral edge portion 10D. In other words, it is preferable that the support surface HA of the support member H is in contact with the entire circumferential section of the regions 10DA and 10DB. However, not limited thereto, the support member H may sandwich only a part of the circumferential section of the peripheral edge portion 10D. For example, as shown in FIG. 4, when the power supply unit 17 and the wiring 18 are connected to the electrode layer 14 of the functional film 10, the power supply unit 17 may be arranged at a position overlapping the peripheral edge portion 10D when viewed from the Z direction. In this case, the support member H preferably does not sandwich the section (region) overlapping the power supply unit 17 among the peripheral edge portion 10D, but sandwiches the section (region) not overlapping the power supply unit 17. That is, in this case, it is preferable that the support surface HA of the support member H does not contact the region overlapping the power supply unit 17 among the regions 10DA and 10DB. Thereby, it is possible to prevent the power supply unit 17 from being damaged by the sandwiching of the support member H. In this case, for example, a groove is formed at a position facing the region of the support surface HA overlapping the power supply unit 17, so that contact with the region overlapping the power supply unit 17 can be avoided. Here, the circumferential direction refers to the circumferential direction when the axis passing through the center of the functional film 10 and extending in the Z direction is the central axis.

[0037] (Structure of the support member) The support member H may have any structure capable of sandwiching the peripheral portion 10D, but is preferably an annular (frame-shaped) member when viewed from the Z direction. By being an annular member, it is possible to suitably achieve sandwiching the peripheral portion 10D without sandwiching the central portion 10E. That is, for example, when the support member H is attached to the functional film 10, when viewed from the Z direction, the support member H (annular member) overlaps the peripheral portion 10D, and the space inside the support member H (annular member) overlaps the central portion 10E (the central portion 10E is exposed).

[0038] More specifically, in the example of this embodiment, as shown in FIG. 3, the support member H has a first support member H1 that supports the main surface 10A (region 10DA) and a second support member H2 that supports the main surface 10B (region 10DB). The first support member H1 is a member having a support surface HA that contacts the region 10DA and is annular when viewed from the Z direction. In the example of FIG. 3, the first support member H1 includes a support portion Ha1 and a fixing portion Hb1. The support portion Ha1 is an annular member when viewed from the Z direction, and the surface opposite to the Z direction is the support surface HA. The fixing portion Hb1 is a portion that protrudes radially outward from the support portion Ha1. The second support member H2 is a member having a support surface HA that contacts the region 10DB and is annular when viewed from the Z direction. In the example of FIG. 3, the second support member H2 includes a support portion Ha2 and a fixing portion Hb2. The support portion Ha2 is an annular member when viewed from the Z direction, and the surface in the Z direction is the support surface HA. The fixing portion Hb2 is a portion that protrudes radially outward from the support portion Ha2.

[0039] When attaching such a support member H to the functional film 10, as shown in FIG. 3, the support surface HA of the first support member H1 is brought into contact with the region 10DA, and the support surface HA of the second support member H2 is brought into contact with the region 10DB, and the fixing portion H1b of the first support member H1 and the fixing portion H2b of the second support member H2 are arranged in a state facing each other. Then, a load is applied to the fixing portion H1b and the fixing portion H2b in a direction approaching each other. Thereby, the peripheral portion 10D is sandwiched between the support surface HA of the first support member H1 and the support surface HA of the second support member H2. Note that the method of applying a load to the fixing portions H1b and H2b may be arbitrary, and examples thereof include fixing the fixing portion H1b and the fixing portion H2b with bolts or the like.

[0040] Note that the support surface HA may have an arbitrary shape, for example, it may be planar, but in the present embodiment, it is a three-dimensional curved surface shape. The support surface HA preferably has a shape corresponding to the shape of the peripheral portion 10D that is desired to be realized by bending. In the present embodiment, the support surface HA that is in contact with the main surface 10A (region 10DA) has a curved surface shape that is convex in the direction opposite to the Z direction, and the support surface HA that is in contact with the main surface 10B (region 10DB) has a curved surface shape that is concave in the direction opposite to the Z direction.

[0041] Also, the support member H may be made of an arbitrary material, but it is preferably made of a member having a Young's modulus higher than that of the functional film 10. For example, the Young's modulus of the support member H is preferably 5 GPa or more, more preferably 10 GPa or more, and may be, for example, 30 GPa or more, 50 GPa or more, or 100 GPa or more. As the material of the support member H, for example, stainless steel (SUS) or an aluminum alloy can be used. The upper limit of the Young's modulus of the support member H is not particularly limited, and may be, for example, 500 GPa or less, or 300 GPa or less.

[0042] (Support pressure of the support member) When the peripheral edge portion 10D of the functional film 10 is sandwiched by the support member H, the pressure applied from the support member H to the peripheral edge portion 10D is defined as the support pressure. In this case, the support pressure by the support member H is preferably 30 kPa or more and 9,000 kPa or less. By the support pressure being 30 kPa or more, the peripheral edge portion 10D where wrinkles are likely to occur can be held with sufficient pressure, and the generation of wrinkles can be suppressed. By the support pressure being 9,000 kPa or less, the generation of scratches on the peripheral edge portion 10D and damage to the structure due to the sandwiching by the support member H can be suppressed. The support pressure by the support member H is preferably 50 kPa or more, more preferably 100 kPa or more, still more preferably 200 kPa or more, even more preferably 500 kPa or more, and particularly preferably 1,000 kPa or more. Also, the support pressure by the support member H is preferably 7,000 kPa or less, more preferably 5,000 kPa or less. That is, the support pressure by the support member H is preferably 30 kPa or more and 9,000 kPa or less, more preferably 50 kPa or more and 7,000 kPa or less, still more preferably 100 kPa or more and 5,000 kPa or less, still more preferably 200 kPa or more and 5,000 kPa or less, even more preferably 500 kPa or more and 5,000 kPa or less, and particularly preferably 1,000 kPa or more and 5,000 kPa or less. Note that the support pressure is calculated by dividing the load applied to the support member H by the area of the support surface HA of the support member H. The load applied to the support member H can be directly measured with a load measuring instrument such as a force gauge or a surface pressure distribution measuring instrument.

[0043] (Support area) As shown in FIG. 4, when viewed from the Z direction, the region where the support surface HA of the support member H and the peripheral edge portion 10D of the functional film 10 overlap is defined as the support region AR. The support region AR can also be said to be the region where the support surface HA and the peripheral edge portion 10D are in contact. Note that the end face HC1 shown in FIG. 4 refers to the end face inside the surface direction of the support member H, and the end face HC2 refers to the end face outside the surface direction of the support member H. That is, in FIG. 4, the region from the end face HC1 to the end face HC2 is the support surface HA.

[0044] When viewed from the Z direction, it is preferable that the end face 10C of the functional film 10 does not protrude outward in the in-plane direction with respect to the end face HC2 of the support member H. In other words, when viewed from the Z direction, it is more preferable that the end face 10C of the functional film 10 is at the same position as the end face HC2 of the support member H or is located inward in the in-plane direction from the end face HC2 of the support member H. In the present embodiment, as shown in FIG. 4, when viewed from the Z direction, the end face 10C of the functional film 10 is located inward in the in-plane direction from the end face HC2 of the support member H. In this case, the outer end side in the plane direction of the support region AR is a side along the end face 10C of the functional film 10, and the inner end side in the plane direction of the support region AR is a side along the inner end face HC1 of the support member H in the plane direction.

[0045] When the end face 10C of the functional film 10 does not protrude outward in the in-plane direction with respect to the end face HC2 of the support member H, it is preferable that the support region AR occupies from the end face 10C of the functional film 10 to a position 5 mm or more and 50 mm or less away from the end face 10C inward in the in-plane direction, and it is more preferable that the support region AR occupies from the end face 10C of the functional film 10 to a position 10 mm or more and 30 mm or less away from the end face 10C inward in the in-plane direction. In other words, when viewed from the Z direction, the shortest distance from the outer end side in the in-plane direction of the support region AR (the end face 10C of the functional film 10 in this example) to the inner end side in the in-plane direction of the support region AR (the inner end face HC1 of the support member H in the plane direction in this example) is defined as the support width L1. In this case, it can be said that it is preferable that the support width L1 is 5 mm or more and 50 mm or less, and it is more preferable that the support width L1 is 10 mm or more and 30 mm or less. When the size of the support area AR and the length of the support width L1 are 5 mm or more, the peripheral edge portion 10D can be appropriately supported by the support member H to suppress wrinkles. When the size of the support area AR and the length of the support width L1 are 50 mm or less, damage to the peripheral edge portion 10D by the support member H can be suppressed. Further, when the size of the support area AR and the length of the support width L1 are 50 mm or less, when providing a shielding layer 28 with an appropriate width so that the peripheral edge portion 10D and the power supply portion 17 of the functional film 10 are not visible, the support area AR is less likely to overlap with the area (opening) surrounded by the shielding layer 28, and the support area AR can be made difficult to be visually recognized.

[0046] However, the end face 10C of the functional film 10 may protrude outward in the in-plane direction with respect to the end face HC2 of the support member H. In this case, the protruding length of the end face 10C of the functional film 10 from the end face HC2 of the support member in the in-plane direction is preferably 30 mm or less, more preferably 20 mm or less, and still more preferably 10 mm or less. Since the protruding length of the end face 10C is short in this way, wrinkles can be appropriately suppressed. In addition, when the end face 10C protrudes outward in the in-plane direction from the end face HC2 of the support member H, the outer end side of the support area AR in the in-plane direction is the side along the end face HC2 of the support member H, and the inner end side of the support area AR in the in-plane direction is the side along the inner end face HC1 of the support member H in the surface direction. In this case, the support area AR preferably occupies a position 5 mm or more and 50 mm or less away from the end face HC1 of the support member H in the inner side in the in-plane direction from the end face HC1, and preferably occupies a position 10 mm or more and 30 mm or less away from the end face 10C of the functional film 10 in the inner side in the in-plane direction from the end face 10C. That is, also in this case, the support width L1 (the shortest distance from the end face HC1 to the end face HC2 in this example) is preferably 5 mm or more and 50 mm or less, and more preferably 10 mm or more and 30 mm or less.

[0047] (Buffer member) FIG. 5 is a schematic diagram showing another example of a state in which a functional film is sandwiched between support members. In the above description, the support surface HA of the support member H and the peripheral edge portion 10D of the functional film 10 were in direct contact, but it is not limited thereto, and a buffer member N may be provided on the support surface HA so that the buffer member N and the peripheral edge portion 10D are in contact with each other. That is, in this example, as shown in FIG. 5, the buffer member N is provided on each support surface HA, and the buffer member N is disposed between the support surface HA and the peripheral edge portion 10D, and the peripheral edge portion 10D is sandwiched by the support member H. More specifically, the buffer member N is disposed between one support surface HA (the support surface HA of the first support member H1) and the region 10DA, and the buffer member N is disposed between the other support surface HA (the support surface HA of the second support member H2) and the region 10DA, and the peripheral edge portion 10D is sandwiched by the support member H.

[0048] The buffer member N is preferably a member having a lower Young's modulus than the support member H so as to easily follow the shapes of the functional film 10 and the support member H. For example, the Young's modulus of the buffer member N is preferably 0.001 GPa or more and 1 GPa or less. Further, the buffer member N preferably has heat resistance and durability. As the material of the buffer member N, for example, fluororubber or silicon sponge can be used.

[0049] (Heating of the functional film) FIG. 6 is a schematic diagram for explaining an example of heating of the functional film. After the peripheral edge portion 10D of the functional film 10 is sandwiched by the support member H as described above, as shown in FIG. 1, the functional film 10 is heated at a heating temperature T1 (step S14). In this step, the functional film 10 is heated at the heating temperature T1 while the peripheral edge portion 10D of the functional film 10 is sandwiched by the support member H. That is, for example, when the functional film 10 is heated in the furnace R, the functional film 10 in a state where the peripheral edge portion 10D is sandwiched by the support member H is disposed in the furnace R, and the functional film 10 is heated in the furnace R.

[0050] The heating temperature T1 of the functional film 10 is higher than the glass transition temperature of the resin film that the functional film 10 has. For example, it is preferably 70°C or higher and 260°C or lower, more preferably 90°C or higher and 240°C or lower, and even more preferably 110°C or higher and 200°C or lower. By setting the heating temperature T1 within this range, it is preferable to appropriately soften the functional film 10 and appropriately curve the functional film 10. Here, the heating temperature T1 refers to the temperature (maximum temperature) that the functional film 10 reaches by heating. For example, when heating in the furnace R, it may be the set temperature in the furnace R. Further, since the functional film 10 is heated with the support member H attached, the support member H may also reach the heating temperature T1.

[0051] In this step, it is preferable to heat the functional film 10 in a state where no load is applied to the functional film 10 by a member other than the support member H (for example, in a state where the mold M described later is not pressed).

[0052] The heating time for heating the functional film 10 is preferably 0.1 minute or longer and 120 minutes or shorter, more preferably 0.5 minute or longer and 60 minutes or shorter, and even more preferably 1 minute or longer and 10 minutes or shorter. By setting the heating time within this range, the functional film 10 can be appropriately heated. Note that the heating time is the time from the start of heating the functional film 10 to the end of heating.

[0053] The heating rate when heating the functional film 10 is not particularly limited, but may be, for example, 2.5°C / minute or higher and 300°C / minute or lower. By setting the heating rate within this range, the functional film 10 can be appropriately heated. Note that the heating rate refers to the rate at which the temperature of the functional film 10 rises.

[0054] (Bending and forming of the functional film) Figures 7 and 8 are schematic diagrams for explaining the bending and forming of the functional film. After heating the functional film 10 as described above, as shown in FIG. 1, the heating of the functional film 10 at the heating temperature T1 is stopped (step S16), and the mold M is pressed against the functional film 10 whose heating has been stopped to bend and form the functional film 10 (step S18).

[0055] In the step of stopping the heating of the functional film 10, the heating of the functional film 10 is stopped while the peripheral portion 10D of the functional film 10 is clamped by the support member H. In this step, the functional film 10 after heating at the heating temperature T1 is placed in an environmental temperature T2 lower than the heating temperature T1 to stop the heating of the functional film 10. The environmental temperature T2 here may be any temperature lower than the glass transition temperature of the resin film of the functional film 10, for example, it may be room temperature, preferably 0°C or higher and 60°C or lower, more preferably 5°C or higher and 40°C or lower, and still more preferably 10°C or higher and 30°C or lower. For example, in this step, the functional film 10 may be taken out of the furnace R and placed at room temperature to stop the heating of the functional film 10.

[0056] In the step of bending and forming, the mold M is pressed against the functional film 10 whose heating has been stopped while the peripheral portion 10D of the functional film 10 is clamped by the support member H to bend and form the functional film 10.

[0057] (Mold) As shown in FIG. 7, the mold M is a member whose surface MA has a curved surface (three-dimensional curved surface) shape that is convex in one direction. The surface MA is the surface pressed against the functional film 10 and has a shape corresponding to the shape of the functional film 10 (central portion 10E) to be realized by bending and forming.

[0058] Furthermore, when the support member H and the mold M described later are arranged such that the inner end point in the radial direction of the support surface HA contacts the outer end point in the radial direction of the surface MA of the mold M, the surface MA preferably has a shape in which the support surface HA and the surface MA are flush (continuous). In other words, the radius of curvature of the support surface HA and the radius of curvature of the surface MA of the mold M described later are preferably substantially the same. Here, "substantially the same" may refer to, for example, the difference between the radius of curvature of the support surface HA and the radius of curvature of the surface MA in a cross-section along the radial direction being 10% or less with respect to the radius of curvature of the surface MA.

[0059] Also, the mold M is preferably composed of a member having a Young's modulus higher than that of the functional film 10. For example, the Young's modulus of the mold M is preferably 5 GPa or more, more preferably 10 GPa or more, and may be, for example, 30 GPa or more, 50 GPa or more, or 100 GPa or more. As the material of the mold M, for example, stainless steel (SUS) or an aluminum alloy can be used. The upper limit of the Young's modulus of the mold M is not particularly limited, but may be, for example, 500 GPa or less, or 300 GPa or less. Also, the mold M is preferably smaller than the region surrounded by the inner end surface HC1 in the in-plane direction of the support member H. Thereby, the mold M can be inserted into the region surrounded by the end surface HC1 of the support member H and pressed against the functional film 10.

[0060] (Pressing of the mold) Here, an area (an area surrounded by the peripheral edge portion 10D) on the main surface 10A of the functional film 10 that is inside the peripheral edge portion 10D in the in-plane direction is defined as the area 10EA. The area 10EA can also be said to be an area that overlaps with the central portion 10E on the main surface 10A. As shown in FIGS. 7 and 8, when the mold M is pressed against the support member H, the surface MA of the mold M is pressed against the area 10EA of the functional film 10 in a state where the peripheral edge portion 10D of the functional film 10 is sandwiched by the support member H. That is, with the surface MA in contact with the area 10EA, a load is applied in the direction from the surface MA toward the area 10EA. As a result, the functional film 10 is recessed so that the main surface 10A (area 10EA) has a shape along the surface MA, and the opposite main surface 10B (area 10EB) protrudes accordingly and curves into a shape along the surface MA. Note that the area 10EB refers to an area on the main surface 10B that overlaps with the central portion 10E. In this way, by pressing the mold M against one main surface 10A (area 10EA), it is possible to suppress the application of loads from both main surfaces, and thus suppress the occurrence of optical distortion called "bump distortion" in the functional film 10.

[0061] In this way, in this step, the functional film 10 is bent and formed by pressing the mold M against one main surface 10A of the functional film 10 to apply a load to the main surface 10A. On the other hand, in this step, the mold M is pressed against the main surface 10A without applying a load by a member other than the support member H to the opposite main surface 10B. In other words, in this step, the peripheral edge portion 10D is sandwiched by the support member H, and the mold M is pressed against the area 10EA to perform bending and forming without applying a load to the area 10EB. Not applying a load to the area 10EB means, for example, keeping the area 10EB in a state of not being supported by another member (a state where the area 10EB is free). By not applying a load to the main surface 10B (area 10EB) in this way, the occurrence of optical distortion can be more preferably suppressed.

[0062] Also, in this step, the mold M is pressed against the functional film 10 whose heating has been stopped (the functional film 10 placed at the environmental temperature T2) and bent and formed. By bending and forming the functional film 10 in a state where the heating has been stopped in this way, the generation of optical distortion can be suppressed. In this step, since the functional film 10 is bent and formed in a state of being slightly cooled due to the stop of heating, it can be bent processed without the main surface of the functional film 10 becoming too soft, and it is estimated that foreign substances and the like can be suppressed from being transferred, so optical distortion can be suppressed.

[0063] The temperature of the main surface of the functional film 10 when the mold M is pressed is less than the heating temperature T1, preferably 70°C or more and less than 260°C, more preferably 90°C or more and less than 240°C, and still more preferably 100°C or more and less than 200°C. By bending and forming the functional film 10 within such a temperature range, optical distortion can be suppressed while being bent appropriately. Note that the temperature of the surface of the support member H when the mold M is pressed may also be within the same temperature range as the temperature of the main surface of the functional film 10.

[0064] The time from the timing when the heating of the functional film 10 is stopped to the timing when the pressing of the mold M is completed (the mold M is separated from the functional film 10) is preferably 1 second or more and 60 seconds or less, more preferably 3 seconds or more and 45 seconds or less, and still more preferably 5 seconds or more and 30 seconds or less. By completing the pressing within such a time, it becomes possible to bend and form the functional film 10 at an appropriate temperature, and optical distortion can be suppressed while being bent appropriately.

[0065] When pressing the mold M against the functional film 10, the pressure applied from the mold M to the functional film 10 is defined as the pressing pressure. In this case, the pressing pressure by the mold M is preferably 0.1 kPa or more and 7,000 kPa or less, more preferably 1 kPa or more and 1,000 kPa or less, and still more preferably 5 kPa or more and 500 kPa or less. When the pressing pressure is 5 kPa or more, the functional film 10 can be appropriately bent, and when the pressing pressure is 7,000 kPa or less, the occurrence of scratches on the functional film 10 by the mold M can be suppressed. The support pressure is calculated by dividing the load applied to the mold M by the area of the surface MA of the mold M. The load applied to the mold M can be directly measured with a load measuring instrument such as a force gauge or a surface pressure distribution measuring instrument.

[0066] The time during which the mold M is pressed against the functional film 10 is defined as the pressing time. In this case, the pressing time by the mold M is preferably 1 second or more and 5 minutes or less, more preferably 2 seconds or more and 2 minutes or less, and still more preferably 3 seconds or more and 1 minute or less. By pressing for such a time, the functional film 10 can be appropriately bent. The pressing time is the time from when the application of the load is started to when the application of the load is stopped with the surface MA of the mold M in contact with the main surface 10A of the functional film 10.

[0067] (Cooling of the functional film) FIG. 9 is a schematic diagram of the functional film after the bending forming is completed. After the pressing of the mold M against the functional film 10 is completed, the pressing of the mold M against the functional film 10 is released, and as shown in FIG. 1, the functional film 10 is cooled (step S20) to obtain the bent functional film 10 (see FIG. 9). In this step, the functional film 10 is cooled to the cooling temperature T3. The cooling temperature T3 may be any temperature lower than the glass transition temperature of the resin film of the functional film 10, for example, it may be in the same temperature range as the environmental temperature T2. That is, for example, the functional film 10 after the pressing of the mold M is completed may be continuously placed under the environmental temperature T2 to cool the functional film 10. In this embodiment, the support member H is removed from the functional film 10 after the pressing of the mold M is completed to cool the functional film 10, but it is not limited thereto, and the functional film 10 with the support member H attached may be cooled.

[0068] (Method for manufacturing laminated glass) Next, a method for manufacturing the laminated glass 1 using the bent functional film 10 obtained as described above will be described. FIG. 10 is a flowchart showing the method for manufacturing the laminated glass according to this embodiment. FIGS. 11 and 12 are schematic diagrams of the laminated glass. FIG. 11 is a schematic cross-sectional view of the laminated glass, and FIG. 12 is a schematic top view of the laminated glass.

[0069] (Preparation of laminate) As shown in FIG. 10, in this manufacturing method, a laminate 1a in which each layer such as the bent functional film 10 is laminated is prepared. (Step S30).

[0070] As shown in FIG. 11, in this step, the laminate 1a is manufactured by laminating a first glass plate 22, an intermediate layer 26 in which the bent functional film 10 is provided inside, and a second glass plate 24 in this order in the Z direction. That is, the laminate 1a is a laminate in which a first glass plate 22, an intermediate layer 26 in which the bent functional film 10 is provided inside, and a second glass plate 24 are laminated in this order in the Z direction.

[0071] More specifically, in the present embodiment, it is preferable to manufacture the laminate 1a by laminating a first glass plate 22, a first intermediate layer 261, a bent functional film 10, a second intermediate layer 262, and a second glass plate 24 in this order in the Z direction. Furthermore, it is more preferable to dispose a third intermediate layer 263 around the functional film 10 disposed between the first intermediate layer 261 and the second intermediate layer 262.

[0072] (Manufacture of laminated glass) After manufacturing the laminate 1a, as shown in FIG. 11, the laminate 1a is heated at an adhesion temperature T4 to bond adjacent layers of the laminate 1a, thereby manufacturing the laminated glass 1. That is, the laminated glass 1 can be said to be a laminate in which each layer of the laminate 1a is bonded.

[0073] The adhesion temperature T4 may be set as appropriate, but it is preferably higher than the glass transition temperature of the resin film of the functional film 10 and lower than the heating temperature T1, more preferably 100°C or higher and 145°C or lower, and even more preferably 105°C or higher and 140°C or lower. By setting the adhesion temperature T4 in this way, it is possible to appropriately bond each layer while suppressing the shape of the bent functional film 10 from returning to its original state.

[0074] (Laminated glass) In this embodiment, the laminated glass 1 is a laminated glass for vehicles. The laminated glass 1 can be suitably used, for example, as window glass for vehicles such as roof glass, rear glass, rear side glass, rear quarter glass, extra glass, windshield, etc. for vehicles. Note that the extra glass is glass attached to the rear side of the vehicle to improve the rear visibility of the vehicle driver. The vehicle here typically refers to an automobile, but includes moving bodies having glass, such as trains, ships, airplanes, etc. However, the use of the laminated glass 1 is not limited to vehicles.

[0075] The thickness of the laminated glass 1 is preferably 2.8 mm or more and 10 mm or less, more preferably 3.0 mm or more and 8.0 mm or less, and even more preferably 4.0 mm or more and 6.0 mm or less. If the thickness of the laminated glass 1 is 2.8 mm or more, sufficient rigidity can be ensured. Also, if the thickness of the laminated glass 1 is 10 mm or less, sufficient transmittance can be obtained and haze (cloudiness) can be reduced. Note that the thickness of the laminated glass 1 refers to the distance in the Z direction from the main surface 1A in the Z direction of the laminated glass 1 to the main surface 1B in the direction opposite to the Z direction. In this example, the main surface 1A is the main surface 24A in the Z direction of the second glass plate 24, and the main surface 1B is the main surface 22B in the direction opposite to the Z direction of the first glass plate 22.

[0076] (Glass plate) Hereinafter, the first glass plate 22 and the second glass plate 24 will be described. The following description may refer to both the first glass plate 22 and the second glass plate 24 before being mounted on the laminate 1a (before adhesion) and the first glass plate 22 and the second glass plate 24 included in the laminated glass 1 (after adhesion). The same applies to other layers.

[0077] The first glass plate 22 and the second glass plate 24 are glass plates facing each other. The first glass plate 22 and the second glass plate 24 may be inorganic glass or organic glass. As the inorganic glass, for example, soda-lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, fused silica glass, etc. can be used without particular limitation. The first glass plate 22 located on the outside is preferably inorganic glass from the viewpoint of scratch resistance, and preferably soda-lime glass from the viewpoint of formability. When the first glass plate 22 and the second glass plate 24 are soda-lime glass, clear glass, green glass containing a predetermined amount or more of iron component, and UV cut green glass can be preferably used. The inorganic glass may be either unstrengthened glass or strengthened glass. The unstrengthened glass is obtained by shaping molten glass into a plate shape and gradually cooling it.

[0078] The strengthened glass is obtained by forming a compressive stress layer on the surface of the unstrengthened glass. The strengthened glass may be either physical strengthened glass such as air-cooled strengthened glass or chemical strengthened glass. In the case of physical strengthened glass, for example, by subjecting a uniformly heated glass plate in bending forming to rapid cooling from a temperature near the softening point, a compressive stress layer is generated on the glass surface due to the temperature difference between the glass surface and the glass interior, thereby strengthening the glass surface.

[0079] On the other hand, examples of the organic glass material include polycarbonate, acrylic resins such as polymethyl methacrylate, transparent resins such as polyvinyl chloride and polystyrene.

[0080] In this embodiment, the first glass plate 22 and the second glass plate 24 are in a curved shape. The shapes of the first glass plate 22 and the second glass plate 24, and the radius of curvature of the curved portion may be arbitrary. In the example of FIG. 11, the first glass plate 22 and the second glass plate 24 are convex in the direction opposite to the outer Z direction, but the present invention is not limited thereto, and they may be concave in the direction opposite to the Z direction. For the bending forming of the first glass plate 22 and the second glass plate 24, gravity forming, press forming, roller forming, etc. are used. The forming method of the first glass plate 22 and the second glass plate 24 is not particularly limited either. For example, in the case of inorganic glass, a glass plate formed by a float method or the like is preferable.

[0081] The thickness of the first glass plate 22 is not particularly limited, but generally, it can be appropriately selected according to the type and part of the vehicle to which the laminated glass 1 is applied within the range of 0.1 mm or more and 10 mm or less. When the thickness of the first glass plate 22 is 0.3 mm or more, the impact resistance is appropriately maintained and the strength such as the anti-chip performance becomes sufficient. It is preferably 0.5 mm or more, more preferably 0.7 mm or more, particularly preferably 1.1 mm or more, and most preferably 1.6 mm or more. Also, when the thickness of the first glass plate 22 is 3 mm or less, the mass of the laminated glass 1 does not become too large, which is preferable from the viewpoint of the vehicle fuel consumption. The thickness of the first glass plate 22 is more preferably 2.6 mm or less, and particularly preferably 2.1 mm or less. Here, when the thickness of the first glass plate 22 is not constant, the thickness of the thinnest part is used.

[0082] The same can be said for the thickness of the second glass plate 24 as for the thickness of the first glass plate 22. The second glass plate 24 may have a composition different from that of the first glass plate 22, or may have a thickness different from that of the first glass plate 22. For example, the second glass plate 24 may be thinner than the first glass plate 22.

[0083] When the thickness of the second glass plate 24 is 1.1 mm or less, from the viewpoint of strength, the second glass plate 24 is preferably chemically strengthened glass.

[0084] On at least one outer surface of the first glass plate 22 and the second glass plate 24, a film having water-repellent, ultraviolet ray and infrared ray cut-off functions, a film having low reflection characteristics, low emissivity characteristics, antifouling properties, or a film having dew condensation prevention characteristics may be provided. Further, on a surface of at least one of the first glass plate 22 and the second glass plate 24 that is in contact with the intermediate layer 26, a film such as ultraviolet ray and infrared ray cut-off, low emissivity characteristics, visible light absorption, or coloring may be provided. Further, a low emissivity (Low-E) coating may be formed on the inner surface of the second glass plate 24 facing the interior of the vehicle. That is, at least one of the first glass plate 22 and the second glass plate 24 may have any one or more of a water-repellent layer, an ultraviolet ray blocking layer, an infrared ray reflecting layer, a low reflectivity layer, a low emissivity layer, a dew condensation prevention layer, a visible light absorption layer, and a coloring layer. Note that at least one of the first glass plate 22, the second glass plate 24, the intermediate layer 26, and the functional film 10 may have these layers.

[0085] In the present embodiment, the laminated glass 1 is a laminated glass having two glass plates, the first glass plate 22 and the second glass plate 24, but the number of glass plates is not limited thereto, and may be three or more.

[0086] (Intermediate layer) The intermediate layer 26 is a film that joins the first glass plate 22 and the second glass plate 24. As shown in FIG. 11, the intermediate layer 26 has, for example, a first intermediate layer 261 that joins the first glass plate 22 and the functional film 10, and a second intermediate layer 262 that joins the second glass plate 24 and the functional film 10. Furthermore, the intermediate layer 26 has a frame-shaped third intermediate layer 263 that is located between the first intermediate layer 261 and the second intermediate layer 262 and surrounds the outer periphery of the functional film 10. However, the intermediate layer 26 may not have the third intermediate layer 263. Even when the third intermediate layer 263 is not present, the outer periphery of the functional film 10 is surrounded by at least one of the first intermediate layer 261 and the second intermediate layer 262 during pressure bonding in the manufacturing process of the laminated glass 1.

[0087] The material of the intermediate layer 26 may be arbitrary, for example, a thermoplastic resin may be used. Examples of the thermoplastic resin include a plasticized polyvinyl acetal resin, a plasticized polyvinyl chloride resin, a saturated polyester resin, a plasticized saturated polyester resin, a polyurethane resin, a plasticized polyurethane resin, an ethylene-vinyl acetate copolymer resin, an ethylene-ethyl acrylate copolymer resin, a cycloolefin polymer resin, an ionomer resin, etc., and it is preferable to use a polyvinyl acetal resin. Examples of the polyvinyl acetal resin include a polyvinyl formal resin obtained by reacting polyvinyl alcohol (hereinafter, may be referred to as "PVA" as necessary) with formaldehyde, a polyvinyl acetal resin in a narrow sense obtained by reacting PVA with acetaldehyde, a polyvinyl butyral resin obtained by reacting PVA with n-butyl aldehyde (hereinafter, may be referred to as "PVB" as necessary), etc., and in particular, PVB is preferably mentioned.

[0088] As the intermediate layer 26, a curable transparent resin also called Optical Clear Resin (OCR) or a transparent adhesive sheet also called Optical Clear Adhesive (OCA) may be used. Further, the intermediate layer 26 may contain functional particles such as an infrared absorber, an ultraviolet absorber, a light emitter, etc. Further, the intermediate layer 26 may have a colored portion called a shade hand.

[0089] The thickness of the intermediate layer 26 is preferably 0.3 mm or more at the thinnest part. When the thickness of the thinnest part of the intermediate layer 26 is 0.3 mm or more, the impact resistance required for the laminated glass 1 is sufficient. The thickness of the intermediate layer 26 is preferably 3 mm or less at the thickest part. When the maximum value of the thickness of the intermediate layer 26 is 3 mm or less, the mass of the laminated glass 1 does not become too large. The maximum value of the thickness of the intermediate layer 26 is more preferably 2.8 mm or less, and even more preferably 2.6 mm or less. Note that the thickness of the intermediate layer 26 refers to, for example, the thickness of only the intermediate layer 26 excluding the thickness of the functional film 10. Therefore, the thickness of the intermediate layer 26 refers to the length obtained by subtracting the thickness of the functional film 10 from the thickness from the surface of the second intermediate layer 262 facing the second glass plate 24 to the surface of the first intermediate layer 261 facing the first glass plate 22.

[0090] Note that the intermediate layer 26 may have one layer, or may have two or more layers, particularly three or more layers. Further, it is preferable that the first intermediate layer 261, the second intermediate layer 262, and the third intermediate layer 263 included in the intermediate layer 26 are all formed of the same material, but a part or all of the first intermediate layer 261, the second intermediate layer 262, and the third intermediate layer 263 may be formed of different materials. That is, the first intermediate layer 261, the second intermediate layer 262, and the third intermediate layer 263 may be integrally formed, or may be separately formed from each other. Note that in the present embodiment, a part of the first intermediate layer 261 or the second intermediate layer 262 is formed so as to surround the outer periphery of the functional film 10, but the first intermediate layer 261 and the second intermediate layer 262 may be formed to have the same size as the functional film 10.

[0091] (Shielding layer) The laminated glass 1 may be provided with a shielding layer 28. The shielding layer 28 is an opaque layer and can be provided, for example, in a strip shape along the peripheral edge of the laminated glass 1. The shielding layer 28 overlaps, for example, the peripheral edge of the glass plate and the peripheral edge of the functional film 10 when viewed from the Z direction. The shielding layer 28 is, for example, an opaque (e.g., black) colored ceramic. The shielding layer 28 may be a colored intermediate film, a colored film, or a combination of a colored intermediate film and a colored ceramic having light-shielding properties. The colored film may be integrated with an infrared reflection film or the like. Note that the colored intermediate film or the colored film may be entirely colored, or the surface may be colored or painted.

[0092] By having the opaque shielding layer 28, the laminated glass 1 can suppress the deterioration of a resin such as urethane that holds the peripheral edge of the laminated glass 1 on the vehicle body due to ultraviolet rays. In addition, the power supply unit 17 and the wiring 18 that are electrically connected to the functional film 10 can be concealed so as to be difficult to visually recognize from at least one of the outside and the inside of the vehicle.

[0093] The shielding layer 28 can be formed, for example, by applying a ceramic color paste containing a fusible glass frit containing a black pigment onto the glass plate by screen printing or the like and then firing it, but is not limited thereto. The shielding layer 28 may be formed, for example, by applying an organic ink containing a black or dark pigment onto the glass plate by screen printing, inkjet printing, or the like and then drying it.

[0094] In the example of FIG. 11, the shielding layer 28 is provided at the peripheral edge of the main surface 22B on the side opposite to the Z direction of the first glass plate 22 and at the peripheral edge of the main surface 24A in the Z direction of the second glass plate 24. However, it is not limited thereto, and the shielding layer 28 may be provided at the peripheral edge of at least one of the first glass plate 22 and the second glass plate 24. For example, it may be provided at at least one of the peripheral edge of the main surface 22B of the first glass plate 22 and the peripheral edge of the main surface 24A of the second glass plate 24. Also, for example, the shielding layer 28 may be provided at the peripheral edge of the main surface in the Z direction of the first glass plate 22 or at the peripheral edge of the main surface in the direction opposite to the Z direction of the second glass plate 24. Also, for example, the shielding layer 28 may be provided at the peripheral edge of the functional film 10.

[0095] As shown in FIG. 12, when viewed from the Z direction, the end face on the inner side in the in-plane direction of the shielding layer 28 is defined as end face 28C1, and the end face on the outer side in the in-plane direction of the shielding layer 28, end face 28C2. In this case, when viewed from the Z direction, the end face 10C of the functional film 10 is preferably positioned between the end face 28C1 and the end face 28C2 of the shielding layer 28 in the in-plane direction.

[0096] Also, when viewed from the Z direction, the end face 28C1 of the shielding layer 28 is preferably positioned more inward in the in-plane direction than the inner end side ARa of the support region AR (the region where the support surface HA of the support member H and the peripheral edge 10D are in contact) in the in-plane direction. Also, when viewed from the Z direction, the shortest distance from the end face 28C1 to the end face 28C2 of the shielding layer 28 is defined as the shielding width L2. In this case, the support width L1 (the distance from the outer and inner end sides of the support region AR to the inner end side in the in-plane direction) is preferably shorter than the shielding width L2. By providing the shielding layer 28 in such a position, the shielding layer 28 can appropriately shield the peripheral edge 10D that was sandwiched by the support member H.

[0097] (Effect) As described above, the bending method according to the first aspect of the present disclosure is a bending method for a functional film 10 including a resin film, including sandwiching the peripheral edge 10D of the functional film 10 with a support pressure of 30 kPa or more by a support member H, heating the functional film 10 at a heating temperature T1 higher than the glass transition temperature of the resin film while sandwiching the peripheral edge 10D with the support member H, stopping the heating of the functional film 10 at the heating temperature T1, and pressing a mold M having a three-dimensional curved surface convex in one direction against one main surface 10A of the functional film 10 while sandwiching the peripheral edge 10D with the support member H to bend the functional film 10, and releasing the pressing of the mold M and cooling the functional film 10 to a cooling temperature T3 lower than the glass transition temperature.

[0098] According to this forming method, by performing bending forming while sandwiching the peripheral edge portion 10D of the functional film 10 with the above-described support pressure, it is possible to suppress the occurrence of wrinkles in the functional film 10. Further, according to this forming method, the functional film 10 is heated at the heating temperature T1, and after the heating is released, the mold M is pressed against the main surface 10A to perform bending forming, so that it is possible to suppress the occurrence of optical distortion in the functional film 10.

[0099] The bending forming method according to the second aspect of the present disclosure is the bending forming method according to the first aspect, and it is preferable to press the mold M against the functional film 10 at an environmental temperature T2 lower than the glass transition temperature. According to the present disclosure, since the mold M is pressed against the functional film 10 at the environmental temperature T2, it is possible to appropriately suppress the occurrence of optical distortion in the functional film 10.

[0100] The bending forming method according to the third aspect of the present disclosure is the bending forming method according to the first aspect or the second aspect, and it is preferable to sandwich the peripheral edge portion 10D with a support pressure of 9,000 kPa or less by the support member H. According to the present disclosure, since the peripheral edge portion 10D is supported with such a support pressure, it is possible to appropriately suppress the occurrence of scratches on the functional film 10.

[0101] The bending forming method according to the fourth aspect of the present disclosure is the bending forming method according to any one of the first aspect to the third aspect, and the support region AR, which is the region where the peripheral edge portion 10D is sandwiched by the support member H, preferably occupies a position 5 mm or more and 50 mm or less inward in the in-plane direction from the end face 10C of the functional film 10 to the end face 10C. According to the present disclosure, since the peripheral edge portion 10D is supported by the support region AR having such a size, it is possible to appropriately suppress the occurrence of wrinkles in the functional film 10.

[0102] The bending method according to the fifth aspect of the present disclosure is the bending method according to the fourth aspect, wherein the support region AR preferably occupies a position 10 mm or more and 30 mm or less inward in the in-plane direction from the end face 10C of the functional film 10. According to the present disclosure, by supporting the peripheral portion 10D with the support region AR of such a size, it is possible to appropriately suppress the occurrence of wrinkles in the functional film 10.

[0103] The bending method according to the sixth aspect of the present disclosure is the bending method according to any one of the first to third aspects, wherein the protruding length of the end face 10C of the functional film 10 from the end face HC2 of the support member H in the in-plane direction is preferably 30 mm or less. By making the protruding length of the end face 10C this short, wrinkles can be appropriately suppressed.

[0104] The bending method according to the seventh aspect of the present disclosure is the bending method according to any one of the first to sixth aspects, wherein the pressing pressure of the mold M against the functional film 10 is preferably 0.1 kPa or more and 7,000 kPa or less. By setting the pressing pressure within this range, the functional film 10 can be appropriately bent.

[0105] The bending method according to the eighth aspect of the present disclosure is the bending method according to any one of the first to seventh aspects, wherein the support surface HA, which is the surface that sandwiches the peripheral portion 10D of the support member H, is preferably a three-dimensional curved surface. By making the support surface HA a three-dimensional curved surface, the peripheral portion 10D can also be appropriately curved.

[0106] The bending method according to the ninth aspect of the present disclosure is the bending method according to any one of the first to eighth aspects, wherein a buffer member N is preferably provided on the support surface HA, which is the surface that sandwiches the peripheral portion 10D of the support member H. By providing the buffer member N, it is possible to suppress damage to the peripheral portion 10D.

[0107] The bending method according to the tenth aspect of the present disclosure is the bending method according to any one of the first to ninth aspects, and the resin film preferably contains at least one of polyethylene terephthalate, cycloolefin polymer, polycarbonate, and polystyrene. According to the present disclosure, the functional film 10 having such a resin film can be appropriately bent while suppressing wrinkles and optical distortion.

[0108] The bending method according to the eleventh aspect of the present disclosure is the bending method according to any one of the first to tenth aspects, and the functional film 10 preferably contains at least one of a dimming film, a heating film, a transparent display, a film mounted with a light-emitting element, an infrared cut film, and a radio wave control film. According to the present disclosure, the functional film 10 having such a resin film can be appropriately bent while suppressing wrinkles and optical distortion.

[0109] The bending method according to the twelfth aspect of the present disclosure is the bending method according to any one of the first to eleventh aspects, and a power supply unit 17 is preferably connected to the peripheral portion 10D of the functional film 10. According to the present disclosure, the functional film 10 having such a resin film can be appropriately bent while suppressing wrinkles and optical distortion.

[0110] The method for manufacturing the laminated glass 1 according to the thirteenth aspect of the present disclosure includes obtaining a laminate 1a by laminating a first glass plate 22 having a curved shape, a first intermediate layer 261, a functional film 10 obtained by the bending method according to any one of the first to eleventh aspects, a second intermediate layer 262, and a second glass plate 24 having a curved shape in this order, and heating the laminate 1a at an adhesion temperature T4 to adhere the layers of the laminate 1a to obtain the laminated glass 1. The adhesion temperature T4 is higher than the glass transition temperature of the resin film and lower than the heating temperature T1. According to the present disclosure, since the laminated glass 1 is manufactured using the functional film 10 that has been appropriately bent in advance, the curved laminated glass 1 can be appropriately manufactured.

[0111] The manufacturing method of the laminated glass 1 according to the 14th aspect of the present disclosure is the manufacturing method of the laminated glass 1 according to the 13th aspect, wherein a shielding layer 28 is provided on at least one peripheral edge of the first glass plate 22 and the second glass plate 24, and the inner end surface 28C1 of the shielding layer 28 in the in-plane direction is preferably located more inward in the in-plane direction than the inner edge ARa of the support region AR in the in-plane direction. Thereby, the shielding layer 28 can appropriately shield the peripheral edge portion 10D that was sandwiched by the support member H.

[0112] (Example) Next, examples will be described. Table 1 is a table showing the functional films of each example. Note that the embodiments may be changed as long as the effects of the invention are achieved.

[0113]

Table 1

[0114] (Example 1) In Example 1, a flat functional film (dimming film) in which a first base material, a first transparent electrode layer, a dimming layer, a second transparent electrode layer, and a second base material were laminated in this order was prepared. The area of the functional film was 62,500 mm 2 and the thickness was 0.4 mm. The first base material and the second base material are resin films made of PET, the first transparent electrode layer and the second transparent electrode layer are electrodes made of ITO, and the dimming layer is PDLC.

[0115] The peripheral edge of such a functional film was sandwiched by a support member combining an aluminum alloy and a heat-resistant resin in a state where the end surface of the functional film was located between the inner end surface and the outer end surface in the in-plane direction of the support member. The support pressure by the support member was 4,000 kPa, and the support width of the support member (the distance from the end surface of the functional film to the inner end surface in the in-plane direction of the indicating member) was 10 mm.

[0116] The functional film with the peripheral edge portion sandwiched by the support member was heated at a heating temperature of 150 ° C and a heating time of 30 minutes. Thereafter, heating was released, and in an environment with an ambient temperature of 25°C, a mold M having a curved surface convex in one direction was pressed against one main surface of the functional film to bend and form the functional film. The pressing pressure was 7 kPa, and the pressing time was 30 seconds. Note that the time from releasing the heating to completing the pressing was 35 seconds.

[0117] (Examples 2 to 4) In Examples 2 to 4, the dimming films were bent and formed in the same process as in Example 1, except that the process conditions were those shown in Table 1. Note that in Example 4, the ambient temperature was 150°C, that is, without releasing the heating, the mold M was pressed against it to bend and form it.

[0118] (Evaluation) As the evaluation, evaluation of wrinkles and evaluation of optical distortion were performed. In the evaluation of wrinkles, when visually observing the functional film after bending and forming, if no wrinkles could be confirmed at all, it was rated as "good"; if wrinkles were only confirmed within 10D of the peripheral part, it was rated as "acceptable"; if wrinkles were confirmed in the central part 10E, or if the dimming layer peeled off from the first transparent electrode layer or the second transparent electrode layer, it was rated as "unacceptable". In the evaluation of optical distortion, when visually observing the central part 10E of the functional film after bending and forming, if mainly granular spots were not confirmed, it was rated as "good"; if confirmed, it was rated as "unacceptable". When the evaluation of wrinkles was "good" or "acceptable" and the evaluation of optical distortion was "good", it was considered qualified; when at least one of the evaluation of wrinkles and the evaluation of optical distortion was "unacceptable", it was considered unqualified.

[0119] As shown in Table 1, Examples 1 and 2, which are examples, were qualified, indicating that wrinkles and optical distortion can be appropriately suppressed. Also, in Example 1, it can be seen that the support width is longer than that in Example 2, and wrinkles can be more appropriately suppressed. On the other hand, Examples 3 and 4, which are comparative examples, were unqualified, indicating that wrinkles and optical distortion cannot be appropriately suppressed. In Example 3, since the support pressure was low, wrinkles could not be appropriately suppressed. In Example 4, since it was bent and formed while heated, optical distortion could not be appropriately suppressed.

[0120] The embodiments of the present invention have been described above. However, the embodiments are not limited by the content of these embodiments. Further, the above-described components include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Still further, various omissions, substitutions, or changes of the components can be made without departing from the gist of the above-described embodiments.

Explanation of Reference Numerals

[0121] 1 Laminated glass 10 Functional film 10A Main surface 10D Peripheral portion H Support member HA Support surface M Mold T1 Heating temperature T2 Ambient temperature

Claims

1. A method for bending a functional film including a resin film, comprising: clamping a peripheral portion of the functional film with a support member at a pressure of 30 kPa or more; heating the functional film at a heating temperature higher than the glass transition temperature of the resin film while the peripheral portion is clamped by the support member; stopping the heating of the functional film at the heating temperature, and while the peripheral portion is clamped by the support member, pressing a mold having a three-dimensional curved surface convex in one direction against one main surface of the functional film to bend the functional film; releasing the pressing of the mold and cooling the functional film to a cooling temperature lower than the glass transition temperature; and a method for bending a functional film.

2. The method for bending a functional film according to claim 1, wherein the mold is pressed against the functional film at an environmental temperature lower than the glass transition temperature.

3. The method for bending a functional film according to claim 1 or claim 2, wherein the peripheral portion is clamped by the support member at a pressure of 9,000 kPa or less.

4. The method for bending a functional film according to claim 1 or claim 2, wherein a support region, which is a region where the peripheral portion is clamped by the support member, occupies a position 5 mm or more and 50 mm or less inward in the in-plane direction from an end face of the functional film.

5. The method for bending a functional film according to claim 4, wherein the support region occupies a position 10 mm or more and 30 mm or less inward in the in-plane direction from an end face of the functional film.

6. The method for bending a functional film according to claim 1 or claim 2, wherein a protruding length of an end face of the functional film from an end face of the support member in the in-plane direction is 30 mm or less.

7. The method for bending a functional film according to claim 1 or claim 2, wherein a pressing pressure of the mold against the functional film is 0.1 kPa or more and 7,000 kPa or less.

8. The method for bending a functional film according to claim 1 or claim 2, wherein a support surface, which is a surface for clamping the peripheral portion of the support member, is in a three-dimensional curved surface shape.

9. The method for bending a functional film according to claim 1 or claim 2, wherein a buffer member is provided on a support surface, which is a surface for clamping the peripheral portion of the support member.

10. The method for bending and forming a functional film according to claim 1 or claim 2, wherein the resin film contains at least one of polyethylene terephthalate, cycloolefin polymer, and polycarbonate.

11. The method for bending and forming a functional film according to claim 1 or claim 2, wherein the functional film contains at least one of a dimming film, a heating film, a transparent display, a film with a light-emitting element mounted thereon, an infrared cut-off film, and a radio wave control film.

12. The method for bending and forming a functional film according to claim 1 or claim 2, wherein a power supply part is connected to the peripheral part of the functional film.

13. Laminating a first glass plate having a curved shape, a first intermediate layer, the functional film obtained by the bending and forming method according to claim 1 or 2, a second intermediate layer, and a second glass plate having a curved shape in this order to obtain a laminate; Heating the laminate at an adhesion temperature to bond each layer of the laminate to obtain laminated glass; comprising the adhesion temperature is higher than the glass transition temperature and lower than the heating temperature; A method for manufacturing laminated glass.

14. A shielding layer is provided on at least one peripheral part of the first glass plate and the second glass plate, The inner end face in the in-plane direction of the shielding layer is located more inward in the in-plane direction than the inner end side of the support region, which is a region where the peripheral part is sandwiched by the support member, in the method for manufacturing laminated glass according to claim 13.

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