Manufacturing method for laminated glass for vehicle windows

Abstract

To provide a method for manufacturing a laminated glass for a vehicle window which corresponds to a plurality of kinds of curved surface shapes and is excellent in quality.SOLUTION: A method for manufacturing a laminated glass for a vehicle window in which first and second glass plate are bonded to each other through an intermediate film includes a lamination step of arranging a functional film containing a resin film between first and second curved plate-like bodies, and forming a laminate, a molding step of heating the functional film to a temperature equal to or higher than a softening point and lower than a melting point of the resin film, and forming a curve functional film, and a first press-bonding step of arranging and press-bonding the intermediate film and the curve functional film between the first and second glass plates, wherein an area of a main surface of the first curved plate-like body is larger than an area of the first main surface facing the main surface of the first curved plate-like body of the functional film, and an area of a main surface of the second curved plate-like body is larger than an area of a second main surface facing the main surface of the second curved plate-like body of the functional film.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for producing laminated glass for vehicle windows. [Background technology]

[0002] There is known a technique for enclosing a functional film such as a light control film in laminated glass. For example, there is laminated glass in which a first glass plate, a first interlayer film, a light control film, a second interlayer film, and a second glass plate are laminated in this order (for example, see Patent Document 1). In this laminated glass, the first glass plate and the second glass plate are formed into a three-dimensional curved surface.

[0003] When manufacturing laminated glass having a functional film between glass sheets having such curved surfaces, wrinkles are likely to occur, for example, at the periphery of the functional film. Patent Document 1 proposes a preparatory process in which a heat forming process is performed to deform the light control film from a flat state into a shape that matches the three-dimensional curved surface of the laminated glass. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-85277 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, since the thermoforming process is carried out by pressing a solid mold having a surface shape that matches the shape of the light control film, processing and tool management that are suited to each desired curved shape are required, making it difficult to flexibly respond to multiple types of curved shapes.

[0006] The present invention has been made in view of the above-mentioned points, and has an object to provide a method for producing laminated glass for vehicle windows that is compatible with a variety of curved surface shapes and has excellent quality. [Means for solving the problem]

[0007] A manufacturing method of laminated glass for vehicle windows according to one embodiment of the disclosure is a manufacturing method of laminated glass for vehicle windows in which first and second glass plates are bonded via an intermediate film, and includes a lamination process of arranging a functional film including a resin film between first and second curved plate-like bodies to form a laminate, a molding process of heating the functional film to a temperature equal to or higher than the softening point and lower than the melting point of the resin film to form a curved functional film, and a first compression process of arranging the intermediate film and the curved functional film between the first and second glass plates and compressing them, wherein an area of ​​a main surface of the first curved plate-like body is larger than an area of ​​a first main surface of the functional film that faces the main surface of the first curved plate-like body, and an area of ​​a main surface of the second curved plate-like body is larger than an area of ​​a second main surface of the functional film that faces the main surface of the second curved plate-like body. Effect of the Invention

[0008] According to one embodiment of the disclosure, it is possible to provide a manufacturing method for a laminated glass for vehicle windows that is compatible with a plurality of types of curved surface shapes and has excellent quality. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a laminated glass for vehicle windows according to an embodiment of the present invention. [Diagram 2] 1 is a perspective view illustrating a laminated glass for a vehicle window according to an embodiment of the present invention. [Diagram 3] 1A to 1C are diagrams illustrating a bending method for a functional film. [Figure 4] FIG. 2 is a diagram illustrating a method for producing a laminated glass for a vehicle window according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiment of the present invention will be described with reference to the drawings. In each drawing, the same components are given the same reference numerals, and duplicated explanations may be omitted. In each drawing, the size and shape may be partially exaggerated to make the contents of the present invention easier to understand.

[0011] The vehicle is typically an automobile, but also refers to any moving body having laminated glass for vehicle windows, including trains, ships, aircraft, etc.

[0012] In addition, the term "planar view" refers to a specified area of ​​the laminated glass for vehicle windows viewed from the normal direction of the surface facing the exterior side of the laminated glass for vehicle windows, and the term "planar shape" refers to the shape of a specified area of ​​the laminated glass for vehicle windows viewed from the normal direction of the surface facing the exterior side of the laminated glass for vehicle windows.

[0013] [Laminated glass for vehicle windows] Fig. 1 is a diagram illustrating a laminated glass for vehicle windows according to the present embodiment, and Fig. 1(a) is a schematic diagram illustrating the laminated glass for vehicle windows attached to a vehicle and viewed from outside the vehicle interior. Fig. 1(b) is a cross-sectional view taken along line AA in Fig. 1(a). Fig. 2 is a perspective view illustrating the laminated glass for vehicle windows according to the present embodiment.

[0014] As shown in Fig. 1 and Fig. 2, the laminated glass for vehicle windows 10 includes a glass plate 11, a glass plate 12, an intermediate film 13, a shielding layer 14, and a curved functional film 15. The glass plates 11 and 12 are bonded together via the intermediate film 13. The glass plate 11 is disposed on a first side (negative side of the Z axis) that faces the inside of the vehicle when the laminated glass for vehicle windows 10 is installed in a vehicle, and the glass plate 12 is disposed on a second side (positive side of the Z axis) that faces the outside of the vehicle when the laminated glass for vehicle windows 10 is installed in a vehicle. The shielding layer 14 is provided as necessary.

[0015] Here, in a plan view of the laminated glass for vehicle windows 10, of the two line segments connecting the midpoints of two pairs of opposing sides, the direction of the shorter line segment is defined as the first direction, and the direction of the longer line segment is defined as the second direction. In the example of FIG. 1(a), the Y-axis direction is the first direction, and the X-axis direction (direction of line AA) is the second direction. In the examples shown in FIG. 1 and FIG. 2, the first direction and the second direction are perpendicular to each other. When the lengths of the two line segments connecting the midpoints of the opposing sides are the same, either one may be defined as the first direction and the second direction, but the direction of the line segment that intersects with the shortest side of the laminated glass for vehicle windows 10 may be defined as the first direction, and the other may be defined as the second direction.

[0016] The laminated glass 10 for vehicle windows has, for example, a complex curved shape curved in both a first direction and a second direction. However, the complex curved shape is not limited to a shape curved in two directions, the first direction and the second direction, but includes a shape curved in two or more different directions. Alternatively, the laminated glass 10 for vehicle windows may have a single curved shape curved in only the first direction or only the second direction. Note that the single curved shape is not limited to a shape curved in only the first direction or only the second direction, but includes a shape curved in only one direction.

[0017] The laminated glass for vehicle windows 10 is preferably curved so as to be convex toward the vehicle exterior (second side). Although the laminated glass for vehicle windows 10 is rectangular in plan view in Fig. 1 and Fig. 2, the laminated glass for vehicle windows 10 is not limited to a rectangular shape and may be any shape including a trapezoidal shape.

[0018] The laminated glass 10 for vehicle windows can be used, for example, as a front glass, rear glass, roof glass, front side glass, rear side glass, front bench glass, rear quarter glass, extra window, etc. of a vehicle.

[0019] The glass plate 11 is an interior glass plate that becomes the interior side (first side) of the vehicle when the laminated glass for vehicle windows 10 is installed in a vehicle. The glass plate 12 is an exterior glass plate that becomes the exterior side (second side) of the vehicle when the laminated glass for vehicle windows 10 is installed in a vehicle. The glass plate 11 is a representative example of the first glass plate according to the present invention, and the glass plate 12 is a representative example of the second glass plate according to the present invention.

[0020] In the laminated glass 10 for vehicle windows, the minimum value of the radius of curvature is preferably 500 mm or more and 100,000 mm or less. The radii of curvature of the glass plates 11 and 12 may be the same or different. When the radii of curvature of the glass plates 11 and 12 are different, the radius of curvature of the glass plate 11 is smaller than the radius of curvature of the glass plate 12.

[0021] The glass plate 11 and the glass plate 12 are a pair of glass plates facing each other, and the intermediate film 13 and the bending function film 15 are located between the pair of glass plates. The glass plate 11 and the glass plate 12 are fixed together with the intermediate film 13 and the bending function film 15 sandwiched therebetween.

[0022] The interlayer film 13 is a film that bonds the glass plate 11 and the glass plate 12. The interlayer film 13 has, for example, a first interlayer film 131 that bonds to the glass plate 11 and a second interlayer film 132 that bonds to the glass plate 12. In addition to the first interlayer film 131 and the second interlayer film 132, a frame-shaped interlayer film that is located between the first interlayer film 131 and the second interlayer film 132 and surrounds the outer peripheral side surface of the curved functional film 15 may be provided. When there is no need to particularly distinguish between the first interlayer film 131 and the second interlayer film 132, they are simply referred to as the interlayer film 13.

[0023] In addition, the outermost contour portion of the object in a plan view is referred to as the periphery, and the area having a width including the periphery is referred to as the peripheral portion. Also, the surface including the periphery and connecting one main surface of the object to the other main surface is referred to as the outer periphery side surface.

[0024] The outer peripheral side surface of the interlayer 13 is preferably edge-treated. In other words, the outer peripheral side surface of the interlayer 13 is preferably treated so as not to protrude significantly from the outer peripheral side surfaces of the glass sheets 11 and 12. If the amount of protrusion of the outer peripheral side surface of the interlayer 13 from the outer peripheral side surfaces of the glass sheets 11 and 12 is 150 μm or less, this is preferable in terms of not impairing the appearance. However, when the laminated glass 10 for vehicle windows is a side glass, the lower edge is hidden by the door panel, so edge treatment of the lower edge of the interlayer 13 is not essential. Details of the glass sheet 11, the glass sheet 12, and the interlayer 13 will be described later.

[0025] The shielding layer 14 is an opaque layer, and can be provided, for example, in a strip shape along the periphery of the laminated glass 10 for vehicle windows. The shielding layer 14 is, for example, an opaque colored ceramic layer, and may be of any color, but is preferably a dark color such as black, brown, gray, or dark blue, and more preferably black. The shielding layer 14 may be a colored intermediate film or colored film having light-shielding properties, a combination of a colored intermediate film and a colored ceramic layer, or a layer having a light-adjusting function. The colored film may be integrated with an infrared reflective film or the like.

[0026] The width of the shielding layer 14 in plan view is, for example, about 10 mm to 250 mm, preferably 20 mm to 220 mm, and more preferably 30 mm to 200 mm. The presence of the opaque shielding layer 14 in the laminated glass for vehicle windows 10 can suppress deterioration of an adhesive made of a resin such as urethane that holds the peripheral portion of the laminated glass for vehicle windows 10 to the vehicle body, caused by ultraviolet rays. In addition, when a power supply member such as a bus bar or an electrode is electrically connected to the peripheral portion of the curved functional film 15, the power supply member electrically connected to the curved functional film 15 can be concealed so as to be difficult to see from the outside and / or inside of the vehicle.

[0027] 1 and 2, the shielding layer 14 is provided on the peripheral portion of the interior surface of the glass plate 12, but the shielding layer 14 may be provided on the peripheral portion of the interior surface of the glass plate 11 as necessary, or may be provided on both the peripheral portion of the interior surface of the glass plate 11 and the peripheral portion of the interior surface of the glass plate 12. Alternatively, the shielding layer 14 need not be provided.

[0028] The curved functional film 15 is enclosed in the intermediate film 13. The curved functional film is a functional film that is originally flat and is formed and curved, and refers to the film after hardening. The surface of the curved functional film 15 facing the glass plate 11 is covered with a first intermediate film 131, and the surface of the curved functional film 15 facing the glass plate 12 is covered with a second intermediate film 132. The curved functional film 15 may be disposed on almost the entire laminated glass 10 for vehicle windows, or may be disposed on only a part of it. The peripheral portion of the curved functional film 15 and the peripheral portions of the glass plates 11 and 12 do not necessarily need to be parallel. The peripheral portion of the curved functional film 15 may overlap with the shielding layer 14 in a plan view.

[0029] The planar shape of the curved function film 15 is, for example, a rectangle smaller than the planar shape of the laminated glass 10 for vehicle windows, but is not limited to a rectangle. The thickness of the curved function film 15 is, for example, 0.1 mm or more and 3 mm or less. When the laminated glass 10 for vehicle windows is applied to a windshield, the curved function film 15 is disposed at a position that does not interfere with the driver's driving.

[0030] The curved functional film 15 has a resin film. The curved functional film 15 may have a multi-layered laminate structure, in which case it may have two or more layers of resin film. However, the curved functional film 15 is a film different from the intermediate film 13. The curved functional film 15 may include at least one of a light control film, an electric heating film, a transparent display, a film equipped with a light emitting element, and an infrared cut film. In other words, the curved functional film 15 has functional layers such as a layer having a light control function, a layer having a heat generation function, a layer having a light emission function, and a layer that reflects / absorbs infrared rays provided on a resin film.

[0031] The light-emitting element may be, for example, an LED (Light Emitting Diode), an organic EL (Organic Electro-Luminescence), or an inorganic EL (Inorganic Electro-Luminescence). The LED here also includes a micro LED. When the curved functional film 15 is an electrically driven member, such as a light control film, an electric heating film, a transparent display, or a film equipped with a light-emitting element, a power supply member such as a bus bar or an electrode is electrically connected to the periphery of the curved functional film 15.

[0032] [Method of manufacturing laminated glass for vehicle windows] The manufacturing method of the laminated glass 10 for vehicle windows includes a step of bending a functional film and a step of producing laminated glass. In the step of bending a functional film, first, as shown in Fig. 3(a), curved plate-like bodies 101 and 102 that serve as molds used to mold the functional film are prepared. The curved plate-like body 101 has a main surface 101a, and the curved plate-like body 102 has a main surface 102a. Here, the curved plate-like body 101 serves as a lower mold, and the curved plate-like body 102 serves as an upper mold.

[0033] The curved plate-like bodies 101 and 102 can be formed from, for example, metals such as iron, titanium, copper, and aluminum, alloys containing these metals such as stainless steel, glasses such as soda lime glass, aluminosilicate glass, and borosilicate glass, and resins such as nylon resin and polycarbonate resin. Among these, the curved plate-like bodies 101 and 102 are preferably formed from metals that are difficult to break and have excellent durability, such as stainless steel. The curved plate-like bodies 101 and 102 may be coated with a release agent in liquid or powder form. The curved plate-like body 101 is a representative example of a first curved plate-like body according to the present invention, and the curved plate-like body 102 is a representative example of a second curved plate-like body according to the present invention.

[0034] The curved plate-like bodies 101 and 102 have a curved shape corresponding to the final laminated glass 10 for a vehicle window. For example, if the final laminated glass 10 for a vehicle window is complex-curved, the curved plate-like bodies 101 and 102 will also have a complex-curved shape, and if the final laminated glass 10 for a vehicle window is single-curved, the curved plate-like bodies 101 and 102 will also have a single-curved shape.

[0035] However, the curved plate-like bodies 101 and 102 do not have to be entirely curved. For example, the curved plate-like bodies 101 and 102 only need to have a curved main surface facing the curved functional film 15, and the main surface opposite the curved functional film 15 does not have to correspond to the shape of the vehicle window laminated glass 10. Below, an example in which the curved plate-like bodies 101 and 102 are entirely curved will be described, but the above may also be applied to the main surfaces of the curved plate-like bodies 101 and 102 facing the curved functional film 15.

[0036] For example, if the radius of curvature of the laminated glass 10 for vehicle windows that is finally manufactured is 500 mm or more and 100,000 mm or less, the radius of curvature of the curved plate-like bodies 101 and 102 is also preferably 500 mm or more and 100,000 mm or less. However, the shapes of the curved plate-like bodies 101 and 102 do not have to completely match the shape of the laminated glass 10 for vehicle windows that is finally manufactured. For example, the minimum value of the radius of curvature of the curved plate-like body 101 may be within a range of ±50% of the minimum value of the radius of curvature of the glass plate 11, preferably within a range of ±30%, and more preferably within a range of ±20%. The minimum value of the radius of curvature of the curved plate-like body 102 may be within a range of ±50% of the minimum value of the radius of curvature of the glass plate 12, preferably within a range of ±30%, and more preferably within a range of ±20%. The same applies to the maximum values ​​of the radii of curvature.

[0037] Even in this case, the curved functional film 15 after molding has a shape that roughly follows the shape of the glass plates 11 and 12. Therefore, in the process of producing the laminated glass 10 for vehicle windows, the curved functional film 15 deforms into a shape that follows the shape of the glass plates 11 and 12, and no visible wrinkles beyond the allowable range are generated in the curved functional film 15. In this way, one type of curved plate-like body 101, 102 can be used to mold functional films to be used for a plurality of types of glass plates 11 and 12 having different curved shapes.

[0038] Furthermore, unlike conventional solid dies, plate-shaped dies such as the curved plate-shaped bodies 101 and 102 are capable of fine-tuning the curved shape to match the curved shapes of the glass plates 11 and 12. In other words, by using plate-shaped dies such as the curved plate-shaped bodies 101 and 102, which are different from conventional dies, a bending forming method for functional films that can accommodate a variety of curved surface shapes can be realized.

[0039] When the curved plate-like body 101 and the curved plate-like body 102 have different radii of curvature, for example, the radius of curvature of the curved plate-like body 101 is smaller than the radius of curvature of the curved plate-like body 102. The thicknesses of the curved plate-like body 101 and the curved plate-like body 102 are almost constant, and are, for example, about 0.3 mm to 10 mm, respectively. Almost constant means that the minimum value of the maximum value of the plate thickness is 0.75 or more. If the plate thickness is 0.3 mm or more, rigidity can be ensured, and if it is within 10 mm, it is easy to flexibly respond to a plurality of curved surface shapes. The plate thicknesses of the curved plate-like body 101 and the curved plate-like body 102 are preferably 1.1 mm or more, and more preferably 1.6 mm or more. In addition, the plate thicknesses of the curved plate-like body 101 and the curved plate-like body 102 are preferably 5 mm or less, and more preferably 3 mm or less. The plate thicknesses of the curved plate-like body 101 and the curved plate-like body 102 may be the same or different.

[0040] The curved plate-like body 102 may have a through hole 102x. The through hole 102x is a through hole for supplying air to remove the curved functional film 15 from the curved plate-like bodies 101 and 102. Although the formation of the through hole 102x is not essential, by forming the through hole 102x in the curved plate-like body 102, it becomes easy to remove the curved functional film 15 from the curved plate-like bodies 101 and 102. The through hole for supplying air may be formed only in the curved plate-like body 101, may be formed only in the curved plate-like body 102, or may be formed in both the curved plate-like bodies 101 and 102.

[0041] The diameter of the through-hole 102x is, for example, 1 mm to 10 mm. The diameter of the through-hole 102x is preferably 3 mm or more. Moreover, if the diameter of the through-hole 102x is 10 mm or less, it is preferable because the bending function film 15 is unlikely to enter the inside of the through-hole 102x, and the diameter of the through-hole 102x is more preferably 5 mm or less.

[0042] The pitch of the through holes 102x is, for example, 10 mm to 200 mm. If the pitch of the through holes 102x is 10 mm or more, it is preferable because the surface of the curved functional film 15 can be easily kept smooth, and more preferably 25 mm or more. In addition, if the pitch of the through holes 102x is 200 mm or less, it is preferable because excellent releasability can be obtained, and more preferably 100 mm or less.

[0043] The diameter and pitch of the through holes 102x do not have to be uniform. For example, the pitch of the through holes 102x may be narrower as it approaches the peripheral edge of the curved plate-like body 102. Furthermore, the through holes 102x may be provided only in a part of the curved plate-like body 102.

[0044] Next, the step shown in Fig. 3(b) is carried out. The step shown in Fig. 3(b) is a lamination step in which a functional film 15X is disposed between curved plate-like bodies 101 and 102 to form a laminate 100. Specifically, first, a functional film 15X is prepared. The functional film 15X is a flat functional film before being formed into a curved functional film 15. In other words, the first main surface 15a and the second main surface 15b of the functional film 15X are substantially two-dimensional flat surfaces. For example, the radius of curvature of the functional film 15X is greater than 100,000 mm.

[0045] The main surface 101a of the curved plate-like body 101 and the first main surface 15a of the functional film 15X face each other in the process of bending the functional film 15X. The main surface 102a of the curved plate-like body 102 and the second main surface 15b of the functional film 15X face each other in the process of bending the functional film 15X. The area of ​​the main surface 101a of the curved plate-like body 101 is larger than the area of ​​the first main surface 15a of the functional film 15X. The area of ​​the main surface 102a of the curved plate-like body 102 is larger than the area of ​​the second main surface 15b of the functional film 15X. In this way, since the area of ​​the main surface of the curved plate-like body 101 is larger than the area of ​​the main surface of the functional film 15X, pressure concentration on the peripheral portion of the functional film 15X is suppressed, and the entire functional film 15X is easily pressurized uniformly. As a result, wrinkles are less likely to occur in the functional film 15X.

[0046] The area of ​​the main surface 101a and the area of ​​the main surface 102a are each, for example, 0.01 m 2 More than 10m 2 The area of ​​the main surface 101a and the area of ​​the main surface 102a are each 0.02 m 2 More than 0.07m is fine. 2 More than 0.1m is fine. 2 The area of ​​the main surface 101a and the area of ​​the main surface 102a may be 9 m or more. 2 Less than 6m is fine. 2 The area of ​​the main surface 101a and the area of ​​the main surface 102a may be the same or different.

[0047] When a through hole is formed in at least one of the curved plate-like bodies 101 and 102, the area of ​​the through hole may also be included in the area of ​​the main surface.

[0048] Next, the functional film 15X is disposed between the curved plate-like bodies 101 and 102 to form the laminate 100. At this time, it is preferable to dispose the main surface 101a so that the outer periphery is outside the outer periphery of the first main surface 15a. It is also preferable to dispose the main surface 102a so that the outer periphery is outside the outer periphery of the second main surface 15b. By disposing the curved plate-like body 101, the curved plate-like body 102, and the functional film 15X in this manner, pressure concentration on the peripheral portion of the functional film 15X is suppressed, and it becomes easier to apply pressure uniformly to the entire functional film 15X. As a result, wrinkles are less likely to occur in the functional film 15X. In addition, by suppressing pressure concentration on the peripheral portion of the functional film 15X, even if the functional film 15X has a power supply member on the peripheral portion, the power supply member is less likely to be damaged. Then, the distance between the curved plate-like body 101 and the curved plate-like body 102 is narrowed from the state shown in Figure 3(b) so that the main surface 101a of the curved plate-like body 101 contacts the first main surface 15a of the functional film 15X and the main surface 102a of the curved plate-like body 102 contacts the second main surface 15b of the functional film 15X.

[0049] Next, the process shown in FIG. 3(c) is carried out. The process shown in FIG. 3(c) is a molding process for forming the curved functional film 15. Specifically, the functional film 15X is heated to a temperature equal to or higher than the softening point and lower than the melting point of the resin film constituting the functional film 15X. The heating method is not particularly limited, and for example, the temperature of the atmosphere (air) may be increased, or the temperatures of the curved plate-like body 101 and the curved plate-like body 102 may be increased. Then, after heating for a predetermined time, the interval between the curved plate-like body 101 and the curved plate-like body 102 is widened, and the curved functional film 15 in which the functional film 15X is hardened in a curved state is taken out. The curved functional film 15 is taken out in a state in which it is cooled to a temperature lower than the softening point of the resin film (for example, room temperature). The process for bending the functional film is thus completed, and the curved functional film 15 is formed. In addition, when the functional film 15X has multiple layers of resin films, it is heated at a temperature equal to or higher than the softening point of the resin film with the highest softening point among the multiple resin films and lower than the melting point of the resin film with the lowest melting point among the multiple resin films.

[0050] After careful consideration, the inventors discovered conditions under which a high-quality curved functional film 15 can be obtained even when the shapes of the curved plate-like bodies 101 and 102 do not completely match the shape of the laminated glass 10 for vehicle windows that will ultimately be manufactured.

[0051] First, the "maximum bending depth" and the "depth of the arc" will be described as indicators of the curved shape. These may be applied to any of the curved plate-like body 101, the curved plate-like body 102, and the laminate 100 including them, but for example, the curved plate-like body 101 will be used for the description. The curved plate-like body 101 described here is an example in which the curved shape of the main surface 101a facing the functional film 15X is substantially the same as the curved shape of the main surface opposite the curved functional film 15. Even if the curved shapes of both main surfaces are different, for example, the "maximum bending depth" and the "depth of the arc" can be measured by producing a mold in which the curved shapes of both main surfaces are substantially the same using the main surface 101a facing the functional film 15X.

[0052] The maximum bending depth is the length of a perpendicular line drawn from the shorter line segment to the deepest point at the bottom of the curved portion when the curved plate body 101 is placed on a horizontal plane with the convex side facing downward and two lines are drawn connecting the midpoints of two pairs of opposing sides, and is expressed in mm. The deepest point at the bottom of the curved portion may be the surface position of the concave side of the curved plate body 101 that corresponds to the contact point with the horizontal plane when the curved plate body 101 is placed on the horizontal plane with the convex side facing downward.

[0053] The maximum bending depth can strongly reflect the curved shape near the center of the curved functional film 15 .

[0054] The depth of the arc is the length, expressed in mm, of a perpendicular line drawn from a plane parallel to the horizontal plane that passes through the highest point of the curved plate body 101 when the curved plate body 101 is placed on the horizontal plane with the convex side facing downward and viewed in a direction parallel to the horizontal plane (for example, the X-axis direction) to the deepest point at the bottom of the curved part. The deepest point at the bottom of the curved part may be the surface position of the concave side of the curved plate body 101 that corresponds to the contact point with the horizontal plane when the curved plate body 101 is placed on the horizontal plane with the convex side facing downward.

[0055] The depth of the arc can strongly reflect the curved shape of the peripheral portion of the curved functional film 15 .

[0056] The maximum bending depth of the curved plate-like body 101 is preferably 2 mm or more, more preferably 4 mm or more, and even more preferably 6 mm or more. The maximum bending depth of the curved plate-like body 101 is preferably 60 mm or less, more preferably 50 mm or less, and even more preferably 40 mm or less.

[0057] The arc depth of the curved plate-like body 101 is preferably 40 mm or more, more preferably 60 mm or more, and even more preferably 80 mm or more. The arc depth of the curved plate-like body 101 is preferably 250 mm or less, more preferably 200 mm or less, and even more preferably 180 mm or less.

[0058] In the above definitions, the maximum bending depth and the arc depth can also be used as indicators of the curved shape of the laminated glass for vehicle windows 10 by replacing the curved plate-like body 101 with the glass plate 11, the glass plate 12, or the laminated glass for vehicle windows 10. The maximum bending depth and the arc depth of the curved plate-like body 101 may be the same as the maximum bending depth and the arc depth of the glass plate 11, respectively.

[0059] Furthermore, the inventors have discovered that even if the shapes of the curved plate-like bodies 101 and 102 do not completely match the shape of the laminated glass for vehicle windows 10 that will ultimately be manufactured, i.e., even if the maximum bending depth and arc depth of the curved plate-like body 101 are different from the maximum bending depth and arc depth of the glass plate 11, respectively, a good-quality laminated glass for vehicle windows 10 can be obtained if formula (1) is satisfied in the lamination process or the forming process.

[0060]

number

[0061] The value of the left side of formula (1) is more preferably 180 or more, and further preferably 250 or more.

[0062] After the lamination step shown in FIG. 3(b), a depressurization step of holding the laminate 100 at a gauge pressure of −70 kPa or less, or a pressurization step of holding the laminate 100 at an absolute pressure of 0.6 MPa or more may be added. These steps may be performed before the preliminary pressure bonding step described later. By adding one or both of these steps, the functional film 15X can be made to conform to the shape of the glass plates 11 and 12. When both of these steps are added, the order of the depressurization step and the pressurization step is preferable. In addition, the pressurization step of holding the laminate 100 at an absolute pressure of 0.6 MPa or more also has the effect of suppressing the occurrence of orange peel. Here, orange peel is a phenomenon in which fine irregularities that do not exceed the thickness of the curved functional film 15 are formed on the curved functional film 15, causing the outline of the reflected image to appear fluctuating. However, if the curved functional film 15 satisfies the required specifications without adding these steps, these steps may not be added.

[0063] In FIG. 3(b), the curved plate-like bodies 101 and 102 are used so that the upper side is convex, but this is not limited thereto, and the curved plate-like bodies 101 and 102 may be used so that the lower side is convex.

[0064] Next, a laminated glass 10 for vehicle windows is produced by the steps shown in Fig. 4(a) and Fig. 4(b). First, glass sheets 11 and 12 are prepared as shown in Fig. 4(a). The glass sheets 11 and 12 are bent into a desired shape that is determined in advance by design drawings, CAD data, or the like. For bending the glass sheets 11 and 12, for example, a gravity forming method can be used in which the glass sheets are placed on a ring mold and passed through a heating furnace, heated and softened, and bent into a desired shape by gravity. Alternatively, a press forming method can be used in which the glass sheets are sandwiched between a male mold and a female mold and pressurized to form the glass sheets.

[0065] If necessary, a shielding layer 14 may be formed on the glass plate 11 and / or the glass plate 12. In the present embodiment, a case where the shielding layer 14 is formed on the glass plate 12 is illustrated. The shielding layer 14 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 the paste, but is not limited thereto. The shielding layer 14 may also be formed, for example, by applying an organic ink containing a black or dark color pigment onto the glass plate by screen printing or the like, and then drying the paste.

[0066] Next, a preliminary pressure-bonding step shown in FIG. 4(b) is performed. In the preliminary pressure-bonding step, the first intermediate film 131, the curved functional film 15 obtained in the step shown in FIG. 3(c), and the second intermediate film 132 are sequentially arranged between the glass plate 11 and the glass plate 12 to form a laminate 120, and the laminate 120 is pressure-bonded. For example, the laminate 120 is placed in a rubber bag, a rubber channel, a resin bag, or the like, and pressure-bonded at a temperature controlled to a range of about 70° C. to 120° C. in a vacuum controlled to a gauge pressure range of −100 kPa to −65 kPa. Alternatively, the laminate 120 may be passed between nipper rolls to apply a pressure equivalent to this to the laminate 120. Heating conditions, temperature conditions, and lamination methods are appropriately selected.

[0067] After the preliminary pressure bonding step shown in Fig. 4(b), a main pressure bonding step is carried out. In the main pressure bonding step, for example, a pressure bonding treatment is carried out by heating and pressing under controlled conditions of an absolute pressure of 0.6 MPa or more and 1.3 MPa or less and a temperature of 100°C or more and 150°C or less. This results in a laminated glass 10 for vehicle windows with excellent durability. In some cases, the main pressure bonding step may not be carried out in consideration of simplification of the process and the characteristics of the material to be filled in the laminated glass 10 for vehicle windows. In other words, the main pressure bonding step is carried out as necessary.

[0068] Here, the glass plate 11, the glass plate 12, and the interlayer film 13 will be described in detail.

[0069] [Glass plate] The glass plates 11 and 12 may be inorganic glass or organic glass. As the inorganic glass, for example, soda-lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, quartz glass, etc. can be used without any particular limitation. The glass plate 12 located on the outer side of the laminated glass for vehicle windows 10 is preferably inorganic glass from the viewpoint of scratch resistance, and is preferably soda-lime glass from the viewpoint of formability. When the glass plates 11 and 12 are soda-lime glass, clear glass, green glass containing a predetermined amount or more of iron components, and UV-cut green glass can be suitably used.

[0070] The inorganic glass may be either unstrengthened glass or tempered glass. Unstrengthened glass is obtained by forming molten glass into a plate shape and slowly cooling it. Tempered glass is obtained by forming a compressive stress layer on the surface of unstrengthened glass.

[0071] The tempered glass may be either physically tempered glass such as air-cooled tempered glass or chemically tempered glass. In the case of physically tempered glass, the glass surface can be tempered by generating a compressive stress layer on the glass surface due to the temperature difference between the glass surface and the inside of the glass by an operation other than slow cooling, such as rapidly cooling a glass sheet uniformly heated in bending from a temperature near the softening point.

[0072] In the case of chemically strengthened glass, for example, after bending, the glass surface can be strengthened by generating a compressive stress on the glass surface by an ion exchange method or the like. Glass that absorbs ultraviolet or infrared rays may also be used. Furthermore, although transparent glass is preferable, a glass plate that is colored to the extent that transparency is not impaired may also be used.

[0073] On the other hand, examples of materials for organic glass include transparent resins such as polycarbonate, acrylic resins such as polymethyl methacrylate, polyvinyl chloride, and polystyrene.

[0074] The shape of the glass plates 11 and 12 is not particularly limited to a rectangular shape, and may be processed into various shapes and curvatures. In addition to the gravity forming method and press forming method described above, a roller forming method or the like may be used for bending the glass plates 11 and 12. The forming method of the glass plates 11 and 12 is also not particularly limited, but for example, in the case of inorganic glass, glass plates formed by a float method or the like are preferable.

[0075] The thickness of the glass plate 12 is preferably 1.1 mm or more and 3 mm or less at the thinnest part. When the thickness of the glass plate 12 is 1.1 mm or more, the strength such as resistance to flying stones is sufficient, and when the thickness is 3 mm or less, the mass of the laminated glass for vehicle windows 10 does not become too large, which is preferable in terms of fuel efficiency of the vehicle. The thickness of the glass plate 12 is more preferably 1.8 mm or more and 2.8 mm or less at the thinnest part, further preferably 1.8 mm or more and 2.6 mm or less, further preferably 1.8 mm or more and 2.2 mm or less, and further preferably 1.8 mm or more and 2.0 mm or less.

[0076] The thickness of the glass plate 11 is preferably 0.3 mm or more and 2.3 mm or less. If the thickness of the glass plate 11 is 0.3 mm or more, the glass plate 11 is easy to handle, and if the thickness is 2.3 mm or less, the weight does not become too large.

[0077] Furthermore, if the thickness of the glass plate 11 is not appropriate, when two pieces of glass with particularly deep curves are formed as the glass plates 11 and 12, a mismatch will occur between the shapes of the two pieces, which will have a significant impact on the glass quality, such as residual stress after compression bonding.

[0078] However, by setting the thickness of the glass plate 11 to 0.3 mm or more and 2.3 mm or less, the glass quality such as residual stress can be maintained. Setting the thickness of the glass plate 11 to 0.3 mm or more and 2.3 mm or less is particularly effective in maintaining the glass quality of deeply curved glass. The thickness of the glass plate 11 is more preferably 0.5 mm or more and 2.1 mm or less, and further preferably 0.7 mm or more and 1.9 mm or less. Within this range, the above-mentioned effects become more remarkable.

[0079] When the laminated glass for vehicle windows 10 is used in, for example, a head-up display (HUD), the glass sheets 11 and / or 12 may not have a constant thickness, but may have a thickness that varies from place to place as necessary. For example, when the laminated glass for vehicle windows 10 is a windshield, one or both of the glass sheets 11 and 12 may have a wedge-shaped cross section whose thickness gradually increases from the lower edge to the upper edge of the windshield when the windshield is attached to a vehicle. In this case, as long as the thickness of the interlayer film 13 is constant, the total wedge angle of the glass sheets 11 and 12 may be changed, for example, in the range of more than 0 mrad to 1.0 mrad or less.

[0080] A coating having water repellency and ultraviolet and infrared blocking properties, or a coating having low reflection and low radiation properties may be provided on the outer side of the glass plates 11 and / or 12. In addition, a coating having ultraviolet and infrared blocking properties, low radiation properties, visible light absorption properties, coloring properties, etc. may be provided on the side of the glass plates 11 and / or 12 that contacts the interlayer film 13.

[0081] When the glass sheets 11 and 12 are curved inorganic glass, the glass sheets 11 and 12 are bent after being formed by a float method or the like and before being bonded with the interlayer film 13. The bending is performed by softening the glass by heating. The heating temperature of the glass during bending is preferably controlled in the range of about 550°C to 700°C.

[0082] [Interlayer] Thermoplastic resins are often used for the intermediate film 13, and examples of such thermoplastic resins include those conventionally used for this type of application, such as plasticized polyvinyl acetal resins, plasticized polyvinyl chloride resins, saturated polyester resins, plasticized saturated polyester resins, polyurethane resins, plasticized polyurethane resins, ethylene-vinyl acetate copolymer resins, ethylene-ethyl acrylate copolymer resins, cycloolefin polymer resins, ionomer resins, etc. Also suitable for use is a resin composition containing a modified hydrogenated block copolymer, as described in Japanese Patent No. 6065221.

[0083] Among these, plasticized polyvinyl acetal resins are preferably used because they have an excellent balance of various properties such as transparency, weather resistance, strength, adhesive strength, penetration resistance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. These thermoplastic resins may be used alone or in combination of two or more. The term "plasticized" in the plasticized polyvinyl acetal resin means that it is plasticized by adding a plasticizer. The same applies to other plasticized resins.

[0084] However, when a specific object is enclosed in the intermediate film 13, the object may be deteriorated by a specific plasticizer depending on the type of object, and in that case, it is preferable to use a resin that does not substantially contain the plasticizer. Examples of resins that do not contain plasticizers include ethylene-vinyl acetate copolymer (EVA) resins.

[0085] Examples of the polyvinyl acetal resin include polyvinyl formal resin obtained by reacting polyvinyl alcohol (PVA) with formaldehyde, polyvinyl acetal resin in the narrow sense obtained by reacting PVA with acetaldehyde, and polyvinyl butyral (PVB) resin obtained by reacting PVA with n-butylaldehyde, and the like. In particular, PVB is preferred because it has an excellent balance of various properties such as transparency, weather resistance, strength, adhesive strength, penetration resistance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. These polyvinyl acetal resins may be used alone or in combination of two or more kinds.

[0086] However, the material forming the intermediate film 13 is not limited to thermoplastic resin. The intermediate film 13 may contain functional particles such as infrared absorbing agents, ultraviolet absorbing agents, and luminescent agents. The intermediate film 13 may have a colored portion called a shade band. The color pigment used to form the colored portion is one that can be used for plastics, and the amount added may be adjusted so that the visible light transmittance of the colored portion is 40% or less. For example, organic color pigments such as azo-based, phthalocyanine-based, quinacridone-based, perylene-based, perinone-based, dioxazine-based, anthraquinone-based, and isoindolino-based pigments, and inorganic color pigments such as oxides, hydroxides, sulfides, chromates, sulfates, carbonates, silicates, phosphates, arsenates, ferrocyanides, carbon, and metal powders may be used. These color pigments may be used alone or in combination of two or more types.

[0087] The thickness of the interlayer film 13 is preferably 0.5 mm or more at the thinnest part. When the interlayer film 13 is composed of the first interlayer film 131 and the second interlayer film 132, the thickness of the interlayer film 13 is the sum of the thickness of the first interlayer film 131 and the thickness of the second interlayer film 132. When the thickness of the thinnest part of the interlayer film 13 is 0.5 mm or more, the impact resistance required for a laminated glass for a vehicle window is sufficient. In addition, the thickness of the interlayer film 13 is preferably 3 mm or less at the thickest part. When the maximum thickness of the interlayer film 13 is 3 mm or less, the mass of the laminated glass for a vehicle window does not become too large. The maximum thickness of the interlayer film 13 is more preferably 2.8 mm or less, and even more preferably 2.6 mm or less.

[0088] When the laminated glass 10 for vehicle windows is used as, for example, a HUD, the interlayer film 13 does not have a constant thickness, and the thickness may vary from place to place as necessary. For example, when the laminated glass 10 for vehicle windows is a windshield, the interlayer film 13 may have a wedge-shaped cross section whose thickness gradually increases from the lower edge to the upper edge of the windshield when the windshield is attached to the vehicle. In this case, as long as the thicknesses of the glass sheets 11 and 12 are constant, the wedge angle of the interlayer film 13 may be changed, for example, in the range of more than 0 mrad to 1.0 mrad or less.

[0089] The interlayer film 13 may have three or more layers. For example, when the interlayer film is formed of three or more layers and the shear modulus of any layer other than the layers on both sides is made smaller than the shear modulus of the layers on both sides by adjusting the plasticizer or the like, the sound insulation of the laminated glass for vehicle windows 10 can be improved. In this case, the shear modulus of the layers on both sides may be the same or different.

[0090] Furthermore, the first interlayer film 131 and the second interlayer film 132 included in the interlayer film 13 are preferably formed of the same material, but may be formed of different materials. However, from the viewpoint of adhesion to the glass plates 11 and 12, or functional materials to be incorporated into the laminated glass 10 for vehicle windows, it is desirable that 50% or more of the thickness of the interlayer film 13 be made of the above-mentioned materials.

[0091] To produce the interlayer film 13, for example, the above-mentioned resin material that will become the interlayer film is appropriately selected and extruded in a heated and molten state using an extruder. The extrusion conditions, such as the extrusion speed of the extruder, are set to be uniform. Thereafter, the extruded resin film is stretched as necessary to give curvature to the upper and lower sides in accordance with the design of the laminated glass for vehicle windows, thereby completing the interlayer film 13.

[0092] [Laminated glass for vehicle windows] The total thickness of the laminated glass for vehicle windows 10 is preferably 2.8 mm or more and 10 mm or less. If the total thickness of the laminated glass for vehicle windows 10 is 2.8 mm or more, sufficient rigidity can be ensured. Also, if the total thickness of the laminated glass for vehicle windows 10 is 10 mm or less, sufficient transmittance can be obtained and haze can be reduced.

[0093] The plate misalignment between the glass plates 11 and 12 is preferably 1.5 mm or less, and more preferably 1 mm or less, on at least one side of the laminated glass for vehicle windows 10. Here, the plate misalignment between the glass plates 11 and 12 refers to the amount of misalignment between the outer peripheral side surface of the glass plate 11 and the outer peripheral side surface of the glass plate 12 in a plan view.

[0094] It is preferable that the misalignment between the glass plates 11 and 12 is 1.5 mm or less on at least one side of the laminated glass for vehicle windows 10, since the appearance is not impaired. It is even more preferable that the misalignment between the glass plates 11 and 12 is 1.0 mm or less on at least one side of the laminated glass for vehicle windows 10, since the appearance is not impaired.

[0095] Examples and Comparative Examples Examples and comparative examples are described below, but the present invention is not limited to these examples. Examples 1 and 2 are examples, and Example 3 is a comparative example.

[0096] [Example 1] In Example 1, a laminated glass LG1 for evaluation having the same structure as the laminated glass 10 for vehicle windows was produced. First, the functional film 15X was pre-bent to produce a curved functional film 15. Specifically, curved plate-like bodies 101 and 102 made of soda lime glass were prepared to have a complex curved shape, and a light control film was placed between the curved plate-like bodies 101 and 102 as the functional film 15X, to form a laminate A in which the curved plate-like body 101, the functional film 15X, and the curved plate-like body 102 were laminated. The dimensions of the curved plate-like body 101 were 1400 mm long x 1100 mm wide x 1.8 mm thick. The dimensions of the curved plate-like body 102 were 1400 mm long x 1100 mm wide x 2.0 mm thick. All of the vertical and horizontal dimensions were measured along the main surface. In addition, the light control film had a PET film on the surface, and an electrode was electrically connected to the periphery. The dimensions of the light-control film before bending, excluding the electrodes, were 1100 mm long x 800 mm wide x 120 μm thick. The maximum bending depth of the laminate A was 40 mm, and the arc depth was 120 mm.

[0097] Next, the laminate A was placed in a resin bag and placed in a vacuum device, the pressure in the vacuum device was reduced to a gauge pressure of -70 kPa or less, and the pressure was maintained at room temperature for 5 to 10 minutes to create a vacuum in the resin bag. Thereafter, the laminate A placed in the resin bag was removed from the vacuum device, and the laminate A was placed in an oven while still in the resin bag, and the oven was maintained at atmospheric pressure and a temperature of 130°C for 30 minutes or more. Thereafter, the laminate A was returned to room temperature and removed from the resin bag, and further force was applied to the laminate A to separate the curved plate-like bodies 101 and 102, and the functional film 15X was removed. A curved functional film 15 curved approximately along the shape of the curved plate-like bodies 101 and 102 was completed. Note that 130°C is a temperature above the softening point and below the melting point of the PET film of the functional film 15X.

[0098] Next, the curved functional film 15 taken out of the resin bag was used to prepare a laminated glass LG1 for evaluation. Specifically, a complex curved glass plate 11 that would become an inner plate (glass plate on the inside of the vehicle) when the laminated glass was prepared, a complex curved glass plate 12 that would become an outer plate (glass plate on the outside of the vehicle), a first intermediate film 131, and a second intermediate film 132 were prepared. The dimensions of the glass plate 11 were 1400 mm long x 1100 mm wide x 1.8 mm thick. The dimensions of the glass plate 12 were 1400 mm long x 1100 mm wide x 2 mm thick. The dimensions of the first intermediate film 131 and the second intermediate film 132 were both 1400 mm long x 1100 mm wide x 0.4 mm thick. EVA was used for the first intermediate film 131 and the second intermediate film 132.

[0099] Then, the glass plate 11, the glass plate 12, the first interlayer film 131, and the second interlayer film 132 were laminated together with the bending function film 15 in the order shown in Fig. 4(b) to produce a laminate B. Next, the laminate B was placed in a rubber bag and bonded at a temperature of about 70°C to 120°C in a vacuum with a gauge pressure of -100 kPa to -65 kPa to produce a laminated glass for evaluation LG1. In the laminated glass for evaluation LG1 produced, the minimum radius of curvature was 905 mm, the maximum bending depth was 40 mm, and the arc depth was 120 mm.

[0100] [Example 2] In Example 2, a laminated glass LG2 for evaluation having the same structure as the laminated glass 10 for vehicle windows was produced. First, a functional film 15X was pre-bent. Specifically, curved plate-shaped bodies 101 and 102 made of glass were prepared, and a light control film was placed between the curved plate-shaped bodies 101 and 102 as the functional film 15X, and a laminate C in which the curved plate-shaped body 101, the functional film 15X, and the curved plate-shaped body 102 were laminated was formed. The curved plate-shaped bodies 101 and 102 and the functional film 15X used were the same as those in Example 1. The maximum bending depth of the laminate C was 40 mm, and the arc depth was 120 mm.

[0101] Next, the laminate C was placed in a resin bag and placed in a vacuum device, the pressure in the vacuum device was reduced to a gauge pressure of -70 kPa or less, and the pressure was maintained at room temperature for 5 to 10 minutes to create a vacuum in the resin bag. Thereafter, the laminate C placed in the resin bag was removed from the vacuum device, and the laminate C was supported in a predetermined manner while still in the resin bag and placed in an autoclave, where it was maintained at an absolute pressure of 1.27 MPa and a temperature of 135°C for 20 minutes. Thereafter, the laminate C was returned to room temperature and removed from the resin bag, and the functional film 15X was removed from the curved plate-like bodies 101 and 102. A curved functional film 15 curved approximately along the shape of the curved plate-like bodies 101 and 102 was completed. Note that 135°C is a temperature above the softening point and below the melting point of the PET film of the functional film 15X.

[0102] Next, a PVB film having a length of 1400 mm, a width of 1100 mm, and a thickness of 0.38 mm was used as the first interlayer film 131, and a PVB film having a length of 1400 mm, a width of 1100 mm, and a thickness of 0.76 mm was used as the second interlayer film 132. The glass plate 11, the glass plate 12, the first interlayer film 131, and the second interlayer film 132 were laminated together with the bending function film 15 in the order shown in FIG. 4(b) to produce a laminate B. Next, the laminate B was placed in a rubber bag and bonded at a temperature of about 70° C. to 120° C. in a vacuum with a gauge pressure of −100 kPa to −65 kPa. Then, pressure and heat were applied under conditions of an absolute pressure of 0.6 MPa to 1.3 MPa and a temperature of about 100° C. to 150° C. to produce a laminated glass LG2 for evaluation. In the prepared laminated glass for evaluation LG2, the minimum radius of curvature was 905 mm, the maximum bending depth was 40 mm, and the arc depth was 120 mm.

[0103] [Example 3] Except for not pre-bending the functional film 15X, a laminated glass for evaluation LG3 was produced in the same manner as in Example 2. In the produced laminated glass for evaluation LG3, the minimum radius of curvature was 905 mm, the maximum bending depth was 40 mm, and the arc depth was 120 mm.

[0104] [Evaluation of Examples 1 to 3] Next, the laminated glasses for evaluation LG1 to LG3 produced in Examples 1 to 3 were evaluated for the occurrence of wrinkles and orange peel in the bending functional film 15, and a comprehensive evaluation was made based on the results.

[0105] <Wrinkles> The laminated glass for evaluation was visually observed for the presence or absence of wrinkles in the functional film at the peripheral portion along the entire outer periphery, and was evaluated according to the following criteria. A: No visible wrinkles were observed on the functional film within 20 mm of the entire circumference of the laminated glass for evaluation (within the acceptable range). C: Visible wrinkles were observed in at least a part of the functional film within 20 mm from the entire outer periphery of the evaluation laminated glass (outside the acceptable range). <Orange peel> The laminated glass for evaluation, which was prepared with a dark background, was placed on a horizontal plane, and a straight-tube fluorescent lamp (length 630 mm, 30 W, Mitsubishi Electric Lighting Co., Ltd. FL30SW) was placed 180 cm above the laminated glass for evaluation so that the length direction was the width direction of the laminated glass for evaluation and was turned on. The position of the fluorescent lamp was adjusted so that it was directly above the center of the laminated glass for evaluation, and the presence or absence of fluctuation in the outline of the reflected image of the fluorescent lamp in the center was visually observed. Similarly, the position of the fluorescent lamp was adjusted so that it was directly above the vicinity of the bottom edge of the laminated glass for evaluation, and the presence or absence of fluctuation in the outline of the reflected image of the fluorescent lamp in the vicinity of the bottom edge was visually observed. The observation results were evaluated according to the following criteria. A: No fluctuation is observed in the outline of the fluorescent light reflection image. C: Fluctuations are observed in at least part of the contour of the fluorescent light reflection image.

[0106] Although it is preferable that orange peel does not occur, it is acceptable for the laminated glass to have orange peel. In other words, if the evaluation result for wrinkles is A, the overall evaluation for the laminated glass is A even if the evaluation result for orange peel is C. On the other hand, if the evaluation result for wrinkles is C, the overall evaluation for the laminated glass is C, regardless of the evaluation result for orange peel.

[0107] [Table 1] The evaluation results of Examples 1 to 3 are summarized in Table 1 together with the conditions for pre-bending the functional film 15X. As shown in Table 1, if the functional film 15X is not pre-bended as in Example 3, unacceptable wrinkles are generated from the outer periphery of the functional film 15X over 70 mm, and the overall evaluation as a laminated glass is C. In contrast, by pre-bending the functional film 15X to prepare a curved functional film 15 as in Examples 1 and 2, the wrinkles are within the acceptable range, and the overall evaluation as a laminated glass is A or higher. Specifically, wrinkles are generated in the curved functional film 15 in Examples 1 and 2, but the position of the wrinkles in Example 1 is within 20 mm from the outer periphery, and the position of the wrinkles in Example 2 is within 10 mm from the outer periphery. In particular, when the pre-bending process of the functional film 15X includes a pressurizing process in which the laminate is held at an absolute pressure of 0.6 MPa or more as in Example 2, orange peel is eliminated, and the overall evaluation as a laminated glass is AA.

[0108] In this way, if the functional film is not pre-bent, wrinkles will occur due to stress generated in the functional film when the functional film follows the curved shape of the glass sheet during the manufacturing process of the laminated glass. In contrast, by pre-bending the functional film to produce a curved functional film, the stress generated in the curved functional film is alleviated before the manufacturing process of the laminated glass, so that wrinkles are less likely to occur even after the manufacturing process of the laminated glass.

[0109] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims. [Explanation of symbols]

[0110] 10. Laminated glass for vehicle windows 11, 12 Glass plate 13 Interlayer 131 First intermediate film 132 Second intermediate film 14 Shielding layer 15 Curved functional film 15X Functional Film 101, 102 Curved plate-shaped body 100, 120 laminate

Claims

1. A method for producing a laminated glass for a vehicle window in which first and second glass sheets are bonded together via an interlayer film, comprising the steps of: a lamination step of disposing a functional film including a resin film between the first and second curved plate-like bodies to form a laminate; a molding step of heating the functional film to a temperature equal to or higher than the softening point and lower than the melting point of the resin film to form a curved functional film; A first pressure-bonding step of disposing and pressure-bonding the intermediate film and the bending function film between the first and second glass plates, an area of ​​a main surface of the first curved plate-like body is larger than an area of ​​a first main surface of the functional film that faces the main surface of the first curved plate-like body; A method for manufacturing laminated glass for vehicle windows, wherein an area of ​​a main surface of the second curved plate-like body is larger than an area of ​​a second main surface of the functional film that faces the main surface of the second curved plate-like body.

2. 2. The method for producing a laminated glass for a vehicle window according to claim 1, wherein the first pressure-bonding step is performed at a gauge pressure of -100 kPa or more and -65 kPa or less and at a temperature of 70°C or more and 120°C or less.

3. 3. The method for manufacturing a laminated glass for a vehicle window according to claim 1, wherein the first and second curved plate-like bodies have a complex curved main surface facing the functional film.

4. 4. The method for producing a laminated glass for a vehicle window according to claim 1, wherein a minimum value of a radius of curvature of the first and second curved plate-like bodies is 500 mm or more and 100,000 mm or less.

5. 5. The method for producing a laminated glass for a vehicle window according to claim 1, further comprising, after the laminating step, a depressurizing step of holding the laminate at a gauge pressure of -70 kPa or less.

6. The method for producing a laminated glass for a vehicle window according to claim 1 , further comprising, after the laminating step, a pressurizing step of holding the laminate at an absolute pressure of 0.6 MPa or more.

7. The area of ​​the main surface of the first and second curved plate-like bodies is 0.01 m ２ 10m or more ２ The method for producing a laminated glass for a vehicle window according to any one of claims 1 to 6, wherein the method is as follows:

8. The method for producing a laminated glass for a vehicle window according to claim 1 , wherein the first or second curved plate-like body has a through hole.

9. 9. The method for manufacturing a laminated glass for a vehicle window according to claim 1, wherein the functional film includes at least one of a light control film, an electric heating film, a transparent display, a light emitting element mounted film, and an infrared ray blocking film.

10. The method for producing a laminated glass for a vehicle window according to claim 1 , wherein a power supply member is electrically connected to a peripheral edge portion of the functional film.

11. 11. The method for manufacturing a laminated glass for vehicle windows according to claim 1, wherein the lamination process includes a process of arranging the first curved plate-like body so that an outer periphery of the main surface of the first curved plate-like body and an outer periphery of the main surface of the second curved plate-like body are respectively outside an outer periphery of the first main surface of the functional film and an outer periphery of the second main surface of the functional film.

12. 12. The method for producing a laminated glass for a vehicle window according to claim 1 , further comprising a second pressing step of performing pressing at an absolute pressure of 0.6 MPa or more and 1.3 MPa or less and at a temperature of 100° C. or more and 150° C. or less after the first pressing step.

13. The minimum value of the radius of curvature of the first curved plate-like body is within a range of ±50% of the minimum value of the radius of curvature of the first glass plate, 13. The method for manufacturing a laminated glass for a vehicle window according to claim 1, wherein a minimum value of a radius of curvature of the second curved plate-like body is in a range of ±50% of a minimum value of a radius of curvature of the second glass plate.

14. The method for producing a laminated glass for a vehicle window according to any one of claims 1 to 13, wherein the first curved plate-shaped body has a maximum bending depth of 2 mm or more and 60 mm or less.

15. The method for manufacturing a laminated glass for a vehicle window according to any one of claims 1 to 14, wherein the arc depth of the first curved plate-like body is 40 mm or more and 250 mm or less.

16. 16. The method for manufacturing a laminated glass for a vehicle window according to claim 1, wherein a maximum bending depth and an arc depth of the first curved plate-like body are equal to a maximum bending depth and an arc depth of the first glass plate, respectively.

17. The maximum bending depth and the arc depth of the first curved plate-like body are different from the maximum bending depth and the arc depth of the first glass sheet, respectively; The method for producing a laminated glass for a vehicle window according to claim 1 , which satisfies the following formula (1): [0010] Where: In a plan view of the first glass plate, of two line segments connecting midpoints of two pairs of opposing sides, a direction of a shorter line segment is defined as a first direction and a direction of a longer line segment is defined as a second direction; L １ is the length [mm] between the midpoints of the opposing sides of the first glass plate along the surface in the first direction, L ２ is the length [mm] between the midpoints of the opposing sides of the first glass plate along the surface in the second direction, W is the maximum bending depth of the first curved plate-like body [mm], W' is the maximum bending depth of the first glass sheet [mm], A is the arc depth of the first curved plate-like body [mm], A' is the arc depth of the first glass sheet [mm], It is.

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