JP2023011440A - Manufacturing method of laminated glass for vehicle window - Google Patents

Abstract

To provide a method for manufacturing a laminated glass for a vehicle window which facilitates a design of a joint condition of a laminate and prevents occurrence of wrinkles in a functional film.SOLUTION: A method for manufacturing a laminated glass for a vehicle window in which first and second glass plates whose main surfaces have curved surfaces are bonded to each other through an intermediate film includes a first lamination step of arranging a functional film including a resin film between first and second molds having curved shapes, and forming a first laminate, a molding step of heating the functional film at a first temperature T1, and forming a curved functional film, a second lamination step of arranging the intermediate film and the curved functional film between the first and second glass plates, and forming a second laminate, and a first pressure-bonding step of pressure-bonding the second laminate at a second temperature T2 at which the second laminate is heated and pressure-bonded, and when a highest temperature in a step following the molding step is represented by Tmax, the first temperature T1 is higher than the highest temperature Tmax.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing laminated glass for vehicle windows.

2. Description of the Related Art In recent years, there has been known a technique of enclosing a functional film such as a light control film in a laminated glass used in a vehicle or the like (see, for example, Patent Documents 1 and 2). In the laminated glass of Patent Document 1, a first glass plate, a first intermediate film, a light control film, a second intermediate film, and a second glass plate are laminated in this order. In this laminated glass, the first glass plate and the second glass plate are formed into three-dimensional curved surfaces.

When manufacturing a laminated glass having a functional film between glass plates having such curved surfaces, for example, wrinkles are likely to occur at the peripheral edge of the functional film. In Patent Document 1, a liquid crystal film is heated to a temperature higher than the glass transition point of a base layer of the liquid crystal film, molded into a three-dimensional curved surface shape of laminated glass, and then the liquid crystal film is sandwiched between two glass plates. It discloses a method of heating the laminate at a temperature below the glass transition point of the base material layer and applying a predetermined pressure to join the laminate.

WO2019/088261 WO2014/122704

By the way, laminated glass is usually manufactured through a preliminary press-bonding process in which the laminated body is held in the range of about 70° C. to 120° C. and, in some cases, a main press-bonding step in which the laminate is further held in the range of about 100° C. to 150° C. There are many. For example, in Patent Document 2, a laminate is pre-bonded at 110° C. using a vacuum bag, and then pressurized and heated at 135° C. using an autoclave. When changing the temperature of these processes, various problems such as poor degassing, poor adhesion, occurrence of foaming, cracking of glass, etc. may occur, so various conditions must be carefully redesigned. On the other hand, in the case of heating at a temperature below the glass transition point of the base material layer and pressing with a predetermined pressure to bond, the base material layer that can be used as a functional film is limited to, for example, types with a relatively high glass transition point. be done.

The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing a laminated glass for vehicle windows in which it is easy to design the joining conditions of the laminate and the functional film is less likely to wrinkle.

A method for manufacturing laminated glass for vehicle windows according to an embodiment of the disclosure is a method for manufacturing laminated glass for vehicle windows in which first and second glass plates having curved main surfaces are bonded via an intermediate film. There is
a first lamination step of placing a functional film containing a resin film between first and second molds having a curved shape to form a _first laminate; a forming step of forming a curved functional film by heating to a second lamination step of forming a second laminate by arranging an intermediate film and a curved functional film between the first and second glass plates; 2 laminated bodies are thermocompressed at a _second temperature T2, and when the maximum temperature in the process after the molding process is _Tmax , the _first temperature T1 is higher than the maximum temperature T _max .

According to one embodiment of the disclosure, it is possible to provide a method for manufacturing a laminated glass for a vehicle window in which it is easy to design the bonding conditions for the laminate and the functional film is less likely to wrinkle.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which illustrates the laminated glass for vehicle windows concerning this embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which illustrates the laminated glass for vehicle windows concerning this embodiment. It is a figure explaining the bending-forming method of a functional film. It is a figure explaining the manufacturing method of the laminated glass for vehicle windows concerning this embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals, and redundant description may be omitted. Also, in each drawing, the size and shape may be partially exaggerated so that the contents of the present invention can be easily understood.

The vehicle is typically an automobile, but also refers to a moving body having laminated glass for vehicle windows, including trains, ships, aircraft, and the like.

Planar view refers to viewing a predetermined area of the laminated glass for vehicle windows from the normal direction of the surface of the laminated glass for vehicle windows on the outside of the vehicle, and planar shape refers to viewing a predetermined area of the laminated glass for vehicle windows from the vehicle. It refers to the shape of the laminated glass for windows viewed from the normal direction of the surface on the vehicle exterior side.

[Laminated glass for vehicle windows]
FIG. 1 is a diagram illustrating a laminated glass for a vehicle window according to the present embodiment, and FIG. 1(a) is a schematic diagram of the laminated glass for a vehicle window in plan view. 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.

As shown in FIGS. 1 and 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 plate 11 and the glass plate 12 are bonded with an intermediate film 13 interposed therebetween. The glass plate 11 is arranged on the first side (negative side of the Z axis) which is the inner side of the vehicle when the laminated glass for vehicle windows 10 is attached to the vehicle, and the glass plate 12 is the laminated glass for vehicle windows. It is arranged on the second side (the positive side of the Z axis) which is the outside of the vehicle when 10 is attached to the vehicle. In addition, the shielding layer 14 is provided as needed.

Here, in the 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 short line segment is the first direction, and the direction of the long line segment is the first direction. Let it be the second direction. In the example of FIG. 1A, the Y-axis direction is the first direction, and the X-axis direction (the direction of line AA) is the second direction. In the example shown in FIG. 1A, the first direction and the second direction are orthogonal. When two line segments connecting midpoints of opposing sides have the same length, either of the two lines may be the first direction and the second direction. The direction of the line segment intersecting the ten shortest sides may be the first direction, and the other may be the second direction.

The laminated glass for vehicle windows 10 has, for example, a compound curved shape curved in both the first direction and the second direction. However, the compound curved shape is not limited to a shape curved in two directions, the first direction and the second direction, and includes a shape curved in two or more different directions. Alternatively, the laminated glass for vehicle windows 10 may have a single-curved shape that is curved only in the first direction or only in the second direction. Note that the single-curved shape is not limited to a shape curved only in the first direction or only in the second direction, and includes a shape curved only in any one direction. Also, curved shapes may include single-curved shapes and compound-curved shapes. A curved surface is also called a curved surface.

The laminated glass for vehicle windows 10 is preferably curved so as to be convex toward the outside of the vehicle (second side). In FIG. 1A, the laminated glass for vehicle windows 10 has a rectangular shape in plan view, but the laminated glass for vehicle windows 10 is not limited to a rectangular shape, and may have any shape including a trapezoidal shape. I do not care.

The laminated glass 10 for vehicle windows can be applied, for example, to a vehicle windshield, rear glass, roof glass, front side glass, rear side glass, front bench glass, rear quarter glass, extra window, and the like.

The glass plate 11 is a vehicle-interior glass plate that becomes the vehicle interior (first side) when the laminated glass for vehicle windows 10 is attached to the vehicle. Further, the glass plate 12 is a vehicle-exterior glass plate that becomes the vehicle exterior (second side) when the vehicle window laminated glass 10 is attached to the vehicle. The glass plate 11 is a typical example of the first glass plate according to the present invention, and the glass plate 12 is a typical example of the second glass plate according to the present invention.

In the laminated glass for vehicle windows 10, the minimum value of the radius of curvature is preferably 500 mm or more and 100000 mm or less. The radii of curvature of the glass plate 11 and the glass plate 12 may be the same or different. When the curvature radii of the glass plate 11 and the glass plate 12 are different, the curvature radius of the glass plate 11 is smaller than the curvature radius of the glass plate 12 .

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 curved functional film 15 are positioned between the pair of glass plates. The glass plate 11 and the glass plate 12 are fixed with the intermediate film 13 and the curved functional film 15 sandwiched therebetween.

The intermediate film 13 is a film that bonds the glass plate 11 and the glass plate 12 together. The intermediate film 13 has, for example, a first intermediate film 131 bonded to the glass plate 11 and a second intermediate film 132 bonded to the glass plate 12 . Apart from the first intermediate film 131 and the second intermediate film 132, there is a frame-shaped intermediate film positioned between the first intermediate film 131 and the second intermediate film 132 and surrounding the outer peripheral side surface of the bendable functional film 15. You may The first intermediate film 131 and the second intermediate film 132 are simply referred to as the intermediate film 13 when there is no particular need to distinguish between them.

Note that the outermost contour portion of the object in plan view is referred to as the outer periphery, and a region having a width including the outer periphery is referred to as the peripheral portion. Moreover, let the surface which includes an outer periphery and connects one main surface and the other main surface of an object be an outer peripheral side surface.

The outer peripheral side surface of the intermediate film 13 is preferably edge-treated. That is, it is preferable that the outer peripheral side surface of the intermediate film 13 is treated so as not to protrude greatly from the outer peripheral side surfaces of the glass plates 11 and 12 . If the amount of protrusion of the outer peripheral side surface of the intermediate film 13 from the outer peripheral side surfaces of the glass plates 11 and 12 is 150 μm or less, it is preferable in terms of not impairing the appearance. However, when the laminated glass for vehicle windows 10 is a side glass, the edge processing of the lower side of the intermediate film 13 is not essential because the lower side is hidden by the door panel. The details of the glass plate 11, the glass plate 12, and the intermediate film 13 will be described later.

The shielding layer 14 is an opaque layer, and can be provided, for example, in a belt shape along the periphery of the laminated glass for vehicle windows 10 . The shielding layer 14 is, for example, an opaque colored ceramic layer and may be of any color, preferably dark colors such as black, brown, gray and navy blue, or white, more preferably black. The shielding layer 14 may be a colored intermediate film or colored film having a light shielding property, a combination of a colored intermediate film and a colored ceramic layer, or a layer having a light control function. The colored film may be integrated with an infrared reflective film or the like.

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, more preferably 30 mm to 200 mm. The presence of the opaque shielding layer 14 in the laminated glass 10 for vehicle windows suppresses deterioration of an adhesive made of a resin such as urethane, which holds the peripheral edge of the laminated glass 10 for vehicle windows to the vehicle body, due to ultraviolet rays. Further, when a power supply member such as a bus bar or an electrode is electrically connected to the peripheral portion of the bendable functional film 15, the power supply member electrically connected to the bendable functional film 15 can be visually recognized from outside and/or inside the vehicle. It can be hidden so that it is difficult to

In the example of FIGS. 1 and 2, the shielding layer 14 is provided on the peripheral edge of the surface of the glass plate 12 on the vehicle interior side. However, the shielding layer 14 may be provided on the peripheral edge of the vehicle-interior surface of the glass plate 11 as necessary, or may be provided on the peripheral edge of the vehicle-interior surface of the glass plate 11 and the vehicle-interior surface of the glass plate 12 . may be provided on both of the peripheral edges of the Alternatively, the shielding layer 14 may not be provided.

The bendable functional film 15 is enclosed in the intermediate film 13 . The curved functional film is obtained by molding and curving an originally flat functional film, and refers to the cured film. The surface of the curved functional film 15 on the glass plate 11 side is covered with a first intermediate film 131 , and the surface of the curved functional film 15 on the glass plate 12 side is covered with a second intermediate film 132 . The functional bending film 15 may be arranged substantially entirely on the laminated glass for a vehicle window 10, or may be arranged only on a part thereof. The peripheral edge of the bendable functional film 15 and the peripheral edge of the glass plates 11 and 12 do not necessarily have to be parallel. The peripheral portion of the curved functional film 15 may overlap the shielding layer 14 in plan view.

The planar shape of the functional bendable film 15 is, for example, a rectangle smaller than the planar shape of the laminated glass for vehicle window 10, but is not limited to a rectangle. The thickness of the curved functional film 15 is, for example, 0.1 mm or more and 3 mm or less. When the laminated glass for vehicle windows 10 is applied to a windshield, the functional bending film 15 is arranged at a position that does not hinder the driving of the driver.

The curved functional film 15 has a resin film. The curved functional film 15 may have a laminated structure of multiple layers, in which case it may have two or more layers of resin films. However, the curved functional film 15 is a film different from the intermediate film 13 . The curved functional film 15 may include, for example, at least one of a light control film, an electrothermal film, a transparent display, a light-emitting element-mounted film, an infrared cut film, a radio wave control film, a polarizing film, and a visible light scattering film. In other words, the bending function film 15 has a light control layer, a heat generating layer, a light emitting layer, a layer that reflects/absorbs infrared rays, and a layer that selectively transmits/transmits radio waves of a predetermined wavelength on a resin film. Functional layers are provided, such as reflective/absorbing layers. Alternatively, the curved functional film 15 may be a resin film such as a polarizing film or a visible light scattering film whose entirety acts as a functional layer.

Resin films include, for example, polyethylene terephthalate (PET), polyethylene naphthalate, polyamide, polyether, polysulfone, polyethersulfone, polycarbonate, polystyrene, cyclic polyolefin, polyarylate, polyetherimide, polyetheretherketone, polyimide, and aramid. , polybutylene terephthalate, triacetyl cellulose, polyurethane, and cycloolefin polymer. The resin film more preferably contains one or more selected from the group consisting of polyethylene terephthalate (PET), cycloolefin polymer, polycarbonate, and polystyrene.

The glass transition temperature Tg of the resin film may be, for example, 50°C to 180°C. The glass transition temperature Tg of the resin film may be 55° C. or higher, 60° C. or higher, 65° C. or higher, or 70° C. or higher. Also, the glass transition temperature Tg of the resin film may be 150° C. or lower, 120° C. or lower, 90° C. or lower, or 80° C. or lower.

Note that the light-emitting element is, for example, an LED (Light Emitting Diode), an organic EL (Organic Electro-Luminescence), an inorganic EL (Inorganic Electro-Luminescence), or the like. The LEDs referred to here also include micro LEDs. A transparent display is a transparent member that includes a plurality of light-emitting elements and is capable of displaying images. Also, the light control film is a film that can switch the visible light transmittance, haze, etc. between a plurality of states. The switching mechanism is not particularly limited, and for example, aligned particles or liquid crystals can be used.

When the curved functional film 15 is an electrically driven member, for example, when it is a light control film, an electrothermal film, a transparent display, or a light-emitting element-mounted film, a power supply member such as a bus bar or an electrode is attached to the peripheral portion of the curved functional film 15 . are electrically connected.

A radio wave control film is a layer that selectively transmits, reflects, or absorbs radio waves of a predetermined wavelength. The predetermined wavelength is, for example, a wavelength of 1 mm or longer. Radio waves of a predetermined wavelength include, for example, at least one of submillimeter waves, millimeter waves, microwaves, ultrashort waves, ultrashort waves, short waves, and medium waves.

[Method for manufacturing laminated glass for vehicle window]
A method for manufacturing the laminated glass for vehicle windows 10 will be described with reference to FIG. The manufacturing method includes a forming step of curving a functional film and a step of producing a laminated glass. The forming process for bending the functional film is also called a pre-bending process. In the manufacturing process of the laminated glass for vehicle windows 10, the _first temperature T1 in the pre-bending process is the maximum temperature _Tmax in the processes subsequent to the pre-bending process (during heating of the second laminated body described later). taller than. As a result, it is possible to obtain a laminated glass for a vehicle window in which it is easy to design the bonding conditions of the laminate and the functional film is less likely to wrinkle. The _first temperature T1 and the maximum temperature _Tmax will be detailed later.

In the pre-bending step, first, as shown in FIG. 3(a), molds 101 and 102, which are molds used for molding the functional film, are prepared. Mold 101 has a major surface 101a and mold 102 has a major surface 102a. Here, the mold 101 is the lower mold and the mold 102 is the upper mold.

Molds 101 and 102 are made of, for example, metals such as iron, titanium, copper, and aluminum, alloys containing them such as stainless steel, glasses such as soda lime glass, aluminosilicate glass, borosilicate glass, nylon resin, and polycarbonate. It can be formed from a resin such as a resin. Among these, the molds 101 and 102 are preferably made of a metal that is hard to break and has excellent durability, such as stainless steel. Molds 101 and 102 may be coated with a liquid or powder release agent. Mold 101 is a representative example of the first mold according to the present invention, and mold 102 is a representative example of the second mold according to the present invention.

The molding dies 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 for vehicle windows 10 has a compound curved shape, the molding dies 101 and 102 also have a compound curved shape, and if the finally manufactured laminated glass for vehicle windows 10 has a single curved shape. Molds 101 and 102 also have a single-curved shape. The curved shapes of the molds 101 and 102 are preferably substantially the same as the curved shapes of the curved surfaces of the glass plates 11 and 12 .

However, the molds 101 and 102 do not have to be curved as a whole. For example, the molding dies 101 and 102 may have a curved shape (curved surface) on the main surface facing the curved functional film 15 , and the main surface opposite to the curved functional film 15 may have the shape of the laminated glass 10 for a vehicle window. It does not have to be compatible. An example in which the molds 101 and 102 as a whole have a curved shape will be described below, but the present invention may be applied to the main surfaces of the molds 101 and 102 facing the curved functional film 15 .

For example, if the finally manufactured laminated glass for vehicle windows 10 has a curvature radius of 500 mm or more and 100000 mm or less, the curvature radii of the molds 101 and 102 are also preferably 500 mm or more and 100000 mm or less. However, the shapes of the molds 101 and 102 may not completely match the shape of the final laminated glass for vehicle windows 10 . For example, the minimum radius of curvature of the mold 101 may be within a range of ±50% of the minimum radius of curvature of the glass plate 11, preferably within a range of ±30%, and more preferably within a range of ±20%. The minimum radius of curvature of the mold 102 may be within a range of ±50% of the minimum 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 value of the radius of curvature, respectively.

Even in this case, the curved functional film 15 after molding has a shape roughly along the glass plates 11 and 12 . Therefore, in the process of manufacturing the laminated glass 10 for a vehicle window, the functional bendable film 15 is deformed along the glass plates 11 and 12, and visible wrinkles exceeding the permissible range do not occur in the functional bendable film 15. In this manner, one type of molds 101 and 102 can be used to mold functional films used for a plurality of types of glass plates 11 and 12 having different curved shapes.

Further, if the molds 101 and 102 are plate-shaped molds as shown in FIG. It is possible to realize a method of bending and forming a functional film that is compatible with However, the molds 101 and 102 do not necessarily have to be plate-like. For example, at least one of the molds 101 and 102 may be a non-plate solid mold.

When the radius of curvature of the mold 101 and the radius of curvature of the mold 102 are different, for example, the radius of curvature of the mold 101 is smaller than the radius of curvature of the mold 102 . When the molding die 101 and the molding die 102 are plate-shaped, for example, each may be about 0.3 mm to 10 mm. Further, when the molding die 101 and the molding die 102 are plate-shaped, it is preferable that the plate thickness is substantially constant. “Substantially constant” means that the minimum value for the maximum thickness is 0.75 or more. If the plate thickness is 0.3 mm or more, rigidity can be ensured, and if the plate thickness is 10 mm or less, it is easy to flexibly cope with a plurality of curved surface shapes. The plate thickness of the mold 101 and the mold 102 is preferably 1.1 mm or more, more preferably 1.6 mm or more. Moreover, the plate thickness of the mold 101 and the mold 102 is preferably 5 mm or less, more preferably 3 mm or less. The plate thickness of the mold 101 and the plate thickness of the mold 102 may be the same or different.

The mold 102 may have through holes 102x. The through-hole 102x is an air-supplying through-hole for removing the functional bending film 15 from the molds 101 and 102 . Formation of the through holes 102 x is not essential, but forming the through holes 102 x in the mold 102 facilitates removal of the functional bendable film 15 from the molds 101 and 102 . The through holes for supplying air may be formed only in the mold 101, only in the mold 102, or in both the molds 101 and 102. FIG.

The hole diameter of the through hole 102x is, for example, 1 mm to 10 mm. The hole diameter of the through hole 102x is preferably 3 mm or more. Also, the hole diameter of the through-hole 102x is preferably 10 mm or less because it is difficult for the curved functional film 15 to enter the through-hole 102x, and is more preferably 5 mm or less.

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, the surface of the bendable functional film 15 can be kept smooth, and the pitch is preferably 25 mm or more. Also, the pitch of the through-holes 102x is preferably 200 mm or less for excellent releasability, and is more preferably 100 mm or less.

Note that the hole diameter and pitch of the through holes 102x may not be uniform. For example, the pitch of the through-holes 102x may be narrower as it approaches the periphery of the mold 102 . Also, the through-hole 102x may be provided only in a part of the mold 102 .

Next, the process shown in FIG.3(b) is implemented. The step shown in FIG. 3B is a lamination step of placing the functional film 15X between the molds 101 and 102 to form the laminate 100 (first laminate). Note that this lamination step is also referred to as a first lamination step. Specifically, first, the functional film 15X is prepared. The functional film 15X is a flat functional film before being formed into the curved functional film 15. FIG. That is, the first main surface 15a and the second main surface 15b of the functional film 15X are substantially two-dimensional planes. For example, the radius of curvature of functional film 15X is greater than 100000 mm. It is preferable that the mold 101 and the mold 102 are each larger than the functional film 15X in plan view.

The main surface 101a of the mold 101 and the first main surface 15a of the functional film 15X face each other in the process of bending the functional film 15X. Further, the main surface 102a of the mold 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 mold 101 may be equal to or larger than the area of the first main surface 15a of the functional film 15X, but preferably larger than the area of the first main surface 15a of the functional film 15X. Also, the area of the main surface 102a of the mold 102 may be equal to or larger than the area of the second main surface 15b of the functional film 15X, but preferably larger than the area of the second main surface 15b of the functional film 15X. Since the area of the main surface of the mold 101 is larger than the area of the main surface of the functional film 15X in this way, the concentration of pressure on the peripheral edge of the functional film 15X is suppressed, and the entire functional film 15X is easily pressurized uniformly. Become. As a result, the functional film 15X is less likely to wrinkle.

The area of the principal surface 101a and the area of the principal surface 102a are, for example, 0.01 m ² or more and 10 m ² or less, respectively. The area of the main surface 101a and the area of the main surface 102a may each be 0.02 m ² or more, 0.07 m ² or more, or 0.1 m ² or more. Also, the area of the main surface 101a and the area of the main surface 102a may each be 9 m ² or less, or 6 m ² or less. The area of the main surface 101a and the area of the main surface 102a may be the same or different.

When at least one of the molds 101 and 102 is formed with a through hole, the area of the main surface may also be the area of the through hole.

Next, a functional film 15X is arranged between molds 101 and 102 to form a laminate 100 (first laminate). At this time, it is preferable that the outer circumference of the main surface 101a be arranged to be outside the outer circumference of the first main surface 15a. Moreover, it is preferable to arrange so that the outer circumference of the main surface 102a is outside the outer circumference of the second main surface 15b. By arranging the mold 101, the mold 102, and the functional film 15X in this way, the concentration of pressure on the peripheral edge 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. In addition, since pressure concentration on the peripheral portion of the functional film 15X is suppressed, 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. After that, the distance between the mold 101 and the mold 102 is narrowed from the state of FIG. 102a and the second main surface 15b of the functional film 15X are brought into contact with each other.

Next, the process shown in FIG.3(c) is implemented. The process shown in FIG. 3C is a molding process for forming the curved functional film 15 . Specifically, the functional film 15X (shown in FIG. 3(b)) is heated to a _first temperature T1. The _first temperature T1 is preferably higher than the glass transition temperature Tg of the resin film forming the functional film 15X. Also, the _first temperature T1 may be lower than the melting point of the resin film forming the functional film 15X. The heating method is not particularly limited, and for example, the temperature of the atmosphere (air) may be raised, or the temperature of the mold 101 and the mold 102 may be raised. After heating for a predetermined time, the gap between the mold 101 and the mold 102 is widened, and the cured curved functional film 15 is taken out while the functional film 15X is curved. The bending function film 15 is taken out after being cooled to a temperature (for example, room temperature) below the transition temperature Tg of the resin film. Thus, the forming step (preliminary bending step) of bending the functional film is completed, and the curved functional film 15 is formed. When the functional film 15X has multiple layers of resin films, the glass transition temperature Tg of the resin film having the highest glass transition temperature Tg among the multiple layers of resin films and It may be heated at a temperature lower than the melting point of the resin film having the lowest melting point.

The _first temperature T1 may be, for example, higher than 60°C, higher than 80°C, higher than 100°C, higher than 120°C, higher than 140°C, higher than 160°C. Well, it can be higher than 180°C. The _first temperature T1 may be, for example, 250° C. or lower, or 200° C. or lower.

Here, "bending depth" will be described as an index representing the curved shape. Although this may be applied to any of the mold 101, the mold 102, and the laminate 100 including them, the mold 101 will be used for explanation. Further, the mold 101 described here is an example in which the curved shape of the principal surface 101a facing the functional film 15X and the curved shape of the principal surface opposite to the curved functional film 15 are substantially the same. When the curved shapes are substantially the same, the minimum value of the radius of curvature of one curved shape may be in the range of ±50%, preferably ±30%, and ±20% of the minimum value of the radius of curvature of the other curved shape. is more preferred. The same applies to the maximum value of the radius of curvature. Even if the curved shapes of both main surfaces are different, for example, by using the main surface 101a facing the functional film 15X to produce a mold having substantially the same curved shape on both main surfaces, the "maximum bending depth" can be obtained. can be measured.

The bending depth is obtained by arranging the mold 101 on a horizontal plane with the convex side facing downward and drawing two line segments connecting the midpoints of two pairs of opposing sides. Let the length, in mm, of the perpendicular drawn to the deepest point at the bottom of the . The maximum bending depth is the larger one of the two bending depths. The deepest point at the bottom of the curved portion may be the surface position on the concave side of the mold 101 corresponding to the point of contact with the horizontal surface when the mold 101 is placed on the horizontal surface so that the convex side faces downward. .

The maximum bending depth of the mold 101 is preferably 2 mm or more, more preferably 4 mm or more, and even more preferably 6 mm or more. Also, the maximum bending depth of the mold 101 is preferably 60 mm or less, more preferably 50 mm or less, and even more preferably 40 mm or less.

In the above definition, the bending depth can also be used as an index representing the curved shape of the laminated glass for vehicle windows 10 by replacing the mold 101 with the glass plate 11, the glass plate 12, or the laminated glass for vehicle windows 10. Available. The bending depth of the mold 101 may match the bending depth of the glass plate 11 .

Further, after the first lamination step shown in FIG. 3B, a decompression step of holding the laminate 100 at a gauge pressure of −70 kPa or less, and 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 pre-compression bonding step described below. By adding one or both of these processes, the functional film 15X can conform to the shapes of the glass plates 11 and 12. FIG. When both of these steps are added, the order of decompression step and pressurization step is preferred. In addition, the pressurizing step in which the laminate 100 is held at an absolute pressure of 0.6 MPa or more also has the effect of suppressing the occurrence of orange peel. Here, the orange peel is a phenomenon in which fine irregularities are formed in the curved functional film 15 to the extent that they do not exceed the thickness of the curved functional film 15, and the outline of the reflected image appears to fluctuate.

In FIG. 3B, the molds 101 and 102 are used so that the upper side is convex, but the present invention is not limited to this, and the molds 101 and 102 may be used so that the lower side is convex. good.

Next, the laminated glass 10 for vehicle windows is produced by the steps shown in FIGS. 4(a) and 4(b). First, as shown in FIG. 4A, glass plates 11 and 12 are prepared. The glass plates 11 and 12 are bent into a desired shape predetermined by a design drawing, CAD data, or the like. Therefore, the main surfaces of the glass plates 11 and 12 have curved surfaces. For the bending of the glass plates 11 and 12, for example, a gravity forming method can be used in which the glass plates are placed on a ring mold, passed through a heating furnace, heated and softened, and then bent into a desired shape by gravity. . Alternatively, a press molding method may be used in which a glass plate is sandwiched between a male mold and a female mold and pressurized.

A shielding layer 14 may be formed on the glass plate 11 and/or the glass plate 12 as necessary. In this embodiment, the 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 fusible glass frit containing a black pigment onto a glass plate by screen printing or the like and baking the paste, but is not limited thereto. The shielding layer 14 may be formed by, for example, applying an organic ink containing a black or dark pigment or a white pigment on a glass plate by screen printing or the like, and drying the ink.

Next, a preliminary press-bonding step shown in FIG. 4(b) is carried out. In the preliminary press-bonding step, first, between the glass plate 11 and the glass plate 12, the first intermediate film 131, the curved functional film 15 obtained in the step shown in FIG. A second stacking step is performed to arrange and form a stack 120 (second stack). Next, this laminate 120 (second laminate) is thermocompression bonded. For example, this laminate 120 is placed in a rubber bag or resin bag, or a rubber channel is attached to the peripheral edge, and the temperature is about 70 ° C. or higher in a vacuum controlled in the range of gauge pressure -100 kPa or more -65 kPa or less. Crimping is performed while controlling the temperature within the range of 120°C or less.

The second temperature T2 is lower than the _first temperature T1 in the forming step of forming the curved functional film described above, when the pressure-bonding temperature of the _{second laminate in the preliminary pressure-bonding step is defined as a second temperature} T2. . In general, both plastic deformation and elastic deformation occur above the glass transition temperature Tg and below the melting point of the resin, and the higher the temperature, the greater the rate of plastic deformation. Therefore, the force acting on the bendable functional film to restore its original shape in the preliminary press-bonding process is less likely to cause plastic deformation, and the curved shape of the bendable functional film is likely to be maintained even in the pre-press-bonding process. Therefore, by making the _second temperature T2 lower than the _first temperature T1, wrinkles are less likely to occur in the functional bendable film. Alternatively, without using vacuum, the layered body 120 may be passed between nipper rolls to apply a pressure corresponding to the pressure described above to the layered body 120 . Also in this case, the laminate is heated at a _second temperature T2 lower than the _first temperature T1.

The _second temperature T2 may be higher than the glass transition temperature Tg of the resin film. Therefore, it is not necessary to adjust the _second temperature T2 in consideration of the Tg of the resin film. The _second temperature T2 may be 75° C. or higher, 80° C. or higher, 85° C. or higher, or 90° C. or higher. Also, the _second temperature T2 may be 115° C. or lower, 110° C. or lower, 105° C. or lower, or 100° C. or lower.

After the preliminary step shown in FIG. 4(b), the main pressure bonding step is carried out. Here, for the sake of explanation of the main press-bonding process, the laminate after press-bonding in the preliminary press-bonding process shown in FIG. 4B is also referred to as the laminate 120 (second laminate). In the main pressure-bonding step, the laminate 120 (second laminate) is subjected to a pressure-bonding process of heating and pressurizing under conditions controlled within a range of, for example, 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. conduct. Thereby, the laminated glass 10 for vehicle windows having excellent durability can be obtained. In some cases, the main pressure-bonding step may not be performed in consideration of the simplification of the process and the characteristics of the material to be enclosed in the laminated glass for vehicle window 10 . That is, the main crimping step is performed as necessary.

When the pressure-bonding temperature of the laminate in the main pressure-bonding step is set to a _third temperature T3, the _third temperature T3 may be equal to or higher than the _second temperature T2 and lower than the _first temperature T1. Alternatively, the _third temperature T3 may be lower than the _second temperature T2. Therefore, the curved shape of the curved functional film is likely to be maintained even in the main pressure-bonding step, and wrinkles are less likely to occur in the curved functional film. The _third temperature T3 can also be said to be the heating temperature of the curved functional film 15 .

The _third temperature T3 may also be higher than the glass transition temperature Tg of the resin film. Therefore, it is not necessary to adjust the _third temperature T3 in consideration of the Tg of the resin film. The _third temperature T3 may be 105° C. or higher, 110° C. or higher, 115° C. or higher, or 120° C. or higher. Also, the _third temperature T3 may be 145° C. or lower, 140° C. or lower, 135° C. or lower, or 130° C. or lower.

As described above, in the method for manufacturing the laminated glass for a vehicle window 10 according to one embodiment, after the pre-bending step, as the step of thermocompression bonding the second laminate, the second laminated body is crimped at the _second temperature T2. A first crimping step and a second crimping step crimping at a _third temperature T3 are included. That is, the manufacturing method includes a second pressure bonding step of pressure bonding at a _third temperature T3 at an absolute pressure of 0.6 MPa or more and 1.3 MPa or less after the first pressure bonding step. Both the _second temperature T2 and the _third temperature T3 are lower than the _first temperature T1. That is, the _first temperature T1 is higher than the maximum temperature _Tmax . Therefore, in the processes subsequent to the pre-bending process, a plastic deformation force greater than that in the pre-bending process is less likely to occur in the functional bendable film 15, and the curved shape of the functional bendable film 15 is easily maintained. That is, wrinkles are less likely to occur in the functional bendable film 15 . Also, by setting the _first temperature T1 higher than the maximum temperature _Tmax , it becomes easier to design the joining conditions of the laminate in the steps after the pre-bending step.

The difference between the _first temperature T1 and the maximum temperature _Tmax is preferably 2°C or more, preferably 5°C or more, more preferably 10°C or more, and even more preferably 15°C or more. The upper limit of the difference is not particularly limited, but may be, for example, 90°C, 70°C, 50°C, or 30°C.

In addition, as a step after the preliminary bending step, for example, the step of thermocompression bonding the second laminate may be only one (for example, the first compression step), or two (for example, the first compression step and second crimping step), or three or more. In these cases, the maximum temperature _Tmax may be the _second temperature T2 or the third temperature T3 as long as it is lower than the _first temperature T1, the _second temperature T2 and the _third temperature T It may be a fourth temperature of ₃ or more.

Here, the glass plate 11, the glass plate 12, and the intermediate film 13 are described in detail.

[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. are used without particular limitation. The glass plate 12 positioned outside the laminated glass 10 for a vehicle window is preferably inorganic glass from the viewpoint of scratch resistance, and 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 an iron component, and UV-cut green glass can be suitably used.

The inorganic glass may be either untempered glass or tempered glass. Untempered glass is obtained by shaping molten glass into a plate and slowly cooling it. Tempered glass is obtained by forming a compressive stress layer on the surface of untempered glass.

The tempered glass may be either physically tempered glass such as air-cooled tempered glass or chemically tempered glass. In the case of physically strengthened glass, for example, the temperature difference between the glass surface and the inside of the glass is compressed to the glass surface by an operation other than slow cooling, such as quenching the glass sheet heated uniformly in bending from a temperature near the softening point. By creating a stress layer, the glass surface can be strengthened.

In the case of chemically strengthened glass, for example, after bending, the glass surface can be strengthened by generating compressive stress on the glass surface by an ion exchange method or the like. Also, a glass that absorbs ultraviolet rays or infrared rays may be used, and although transparency is preferred, a glass plate that is colored to such an extent that transparency is not impaired may be used.

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

The shape of the glass plates 11 and 12 is not particularly limited to a rectangular shape, and may be a shape processed into various shapes and curvatures. For the bending of the glass plates 11 and 12, a roller forming method or the like may be used in addition to the gravity forming method and press forming method described above. The method of forming the glass plates 11 and 12 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.

The plate 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, strength such as resistance to stepping stones is sufficient. point is preferable. The thickness of the glass plate 12 at the thinnest part is more preferably 1.8 mm or more and 2.8 mm or less, still more preferably 1.8 mm or more and 2.6 mm or less, even more preferably 1.8 mm or more and 2.2 mm or less. It is more preferably 8 mm or more and 2.0 mm or less.

The plate thickness of the glass plate 11 is preferably 0.3 mm or more and 2.3 mm or less. When the plate thickness of the glass plate 11 is 0.3 mm or more, the handleability is good, and when it is 2.3 mm or less, the mass does not become too large.

Further, if the thickness of the glass plate 11 is not appropriate, if two glasses having a particularly deep bend are formed as the glass plates 11 and 12, the shape of the two sheets will be mismatched, and the quality of the glass such as the residual stress after pressure bonding will be greatly affected. Affect.

However, by setting the plate thickness of the glass plate 11 to 0.3 mm or more and 2.3 mm or less, it is possible to maintain glass quality such as residual stress. Setting the plate thickness of the glass plate 11 to 0.3 mm or more and 2.3 mm or less is particularly effective in maintaining the quality of the glass with a deep bend. The plate thickness of the glass plate 11 is more preferably 0.5 mm or more and 2.1 mm or less, and still more preferably 0.7 mm or more and 1.9 mm or less. Within this range, the above effects are more pronounced.

When the laminated glass for vehicle windows 10 is used for, for example, a head-up display (HUD), the thickness of the glass plates 11 and/or 12 may not be constant, and the thickness may vary depending on the location. For example, when the laminated glass for vehicle windows 10 is a windshield, one or both of the glass plates 11 and 12 have a thickness increasing from the lower side to the upper side of the windshield when the windshield is attached to the vehicle. A gradually increasing cross-sectional wedge shape is also possible. In this case, if the film thickness of the intermediate film 13 is constant, the total wedge angle of the glass plate 11 and the glass plate 12 may be varied within a range of, for example, greater than 0 mrad and less than or equal to 1.0 mrad.

A coating having a function of water repellency, blocking ultraviolet rays and infrared rays, or a coating having low reflection characteristics and low radiation characteristics may be provided on the outside of the glass plates 11 and/or 12 . In addition, the side of the glass plate 11 and/or 12 in contact with the intermediate film 13 may be provided with a film that cuts ultraviolet rays or infrared rays, has low radiation characteristics, absorbs visible light, is colored, or the like.

When the glass plates 11 and 12 are made of curved inorganic glass, the glass plates 11 and 12 are bent after forming by a float method or the like and before bonding with the intermediate film 13 . Bending is performed by softening the glass by heating. The heating temperature of the glass during bending is preferably controlled within a range of approximately 550°C to 700°C.

[Interlayer film]
Thermoplastic resins are often used as the intermediate film 13. For example, plasticized polyvinyl acetal-based resin, plasticized polyvinyl chloride-based resin, saturated polyester-based resin, plasticized saturated polyester-based resin, polyurethane-based resin, and plasticized polyurethane-based resin are used. Resins, ethylene-vinyl acetate copolymer resins, ethylene-ethyl acrylate copolymer resins, cycloolefin polymer resins, ionomer resins, and other thermoplastic resins that have been conventionally used for this type of application. A resin composition containing a hydrogenated modified block copolymer described in Japanese Patent No. 6065221 can also be preferably used.

Among these, plasticized polyvinyl acetal resin is excellent in the balance of performance such as transparency, weather resistance, strength, adhesive strength, penetration resistance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. is preferably used. These thermoplastic resins may be used alone or in combination of two or more. “Plasticization” in the above-mentioned plasticized polyvinyl acetal resin means plasticization by addition of a plasticizer. The same applies to other plasticizing resins.

However, when a specific substance is enclosed in the intermediate film 13, depending on the type of substance to be enclosed, it may be deteriorated by a specific plasticizer. Examples of plasticizer-free resins include ethylene-vinyl acetate copolymer (EVA) resins.

Examples of the polyvinyl acetal-based resin include a polyvinyl formal resin obtained by reacting polyvinyl alcohol (PVA) and formaldehyde, a narrowly defined polyvinyl acetal-based resin obtained by reacting PVA and acetaldehyde, and PVA and n-butyraldehyde. Examples include polyvinyl butyral (PVB) resins obtained by reacting, especially transparency, weather resistance, strength, adhesive strength, penetration resistance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. PVB is preferred because of its excellent balance of properties. These polyvinyl acetal-based resins may be used alone, or two or more of them may be used in combination.

However, the material forming the intermediate film 13 is not limited to thermoplastic resin. Also, the intermediate film 13 may contain functional particles such as an infrared absorber, an ultraviolet absorber, and a light-emitting agent. Also, the intermediate film 13 may have a colored portion called a shade band. The coloring pigment used to form the colored portion is a pigment 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. phthalocyanine-based, quinacridone-based, perylene-based, perinone-based, dioxazine-based, anthraquinone-based, isoindolino-based organic coloring pigments, oxides, hydroxides, sulfides, chromic acid, sulfate, carbonate, silicic acid Inorganic coloring pigments such as salts, phosphates, arsenates, ferrocyanides, carbon, and metal powders are included. These color pigments may be used alone, or two or more of them may be used in combination.

The film thickness of the intermediate film 13 is preferably 0.5 mm or more at the thinnest part. When the intermediate film 13 is composed of the first intermediate film 131 and the second intermediate film 132, the thickness of the intermediate film 13 is the sum of the thickness of the first intermediate film 131 and the thickness of the second intermediate film 132. film thickness. When the thickness of the thinnest portion of the intermediate film 13 is 0.5 mm or more, the impact resistance necessary for laminated glass for vehicle windows is sufficient. Further, the film thickness of the intermediate film 13 is preferably 3 mm or less at the thickest part. When the maximum film thickness of the intermediate film 13 is 3 mm or less, the mass of the laminated glass for vehicle windows does not become excessively large. The maximum thickness of the intermediate film 13 is more preferably 2.8 mm or less, and even more preferably 2.6 mm or less.

When the laminated glass for vehicle windows 10 is used as, for example, a HUD, the intermediate film 13 may not have a constant film thickness, but may have different film thicknesses depending on the location. For example, when the laminated glass for vehicle windows 10 is a windshield, the intermediate film 13 may have a wedge-shaped cross section in which the film thickness gradually increases from the lower side to the upper side of the windshield when the windshield is attached to the vehicle. In this case, if the plate thicknesses of the glass plates 11 and 12 are constant, the wedge angle of the intermediate film 13 may be varied within a range of, for example, greater than 0 mrad and less than or equal to 1.0 mrad.

Note that the intermediate 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 laminated glass for vehicle windows 10 can improve the sound insulation of In this case, the shear moduli of the layers on both sides may be the same or different.

The first intermediate film 131 and the second intermediate film 132 included in the intermediate film 13 are desirably made of the same material, but they may be made of different materials. However, from the viewpoint of adhesiveness to the glass plates 11 and 12, or functional materials to be put into the laminated glass for vehicle windows 10, it is desirable to use the above materials for 50% or more of the film thickness of the intermediate film 13. .

In order to produce the intermediate film 13, for example, the above-described resin material for the intermediate film is appropriately selected and extruded in a heated and melted state using an extruder. The extrusion conditions such as the extrusion speed of the extruder are set so as to be uniform. After that, the extruded resin film is stretched, for example, as necessary in order to give curvature to the upper side and the lower side in accordance with the design of the laminated glass for vehicle windows, thereby completing the intermediate film 13. - 特許庁

[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. Further, 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.

In at least one side of the laminated glass for vehicle windows 10, the deviation between the glass plates 11 and 12 is preferably 1.5 mm or less, more preferably 1 mm or less. Here, the deviation between the glass plate 11 and the glass plate 12 is the amount of deviation between the outer peripheral side surface of the glass plate 11 and the outer peripheral side surface of the glass plate 12 in plan view.

In at least one side of the laminated glass 10 for a vehicle window, it is preferable that the displacement between the glass plates 11 and 12 is 1.5 mm or less in terms of not spoiling the appearance. In at least one side of the laminated glass 10 for a vehicle window, it is more preferable that the displacement between the glass plate 11 and the glass plate 12 is 1.0 mm or less so as not to impair the appearance.

<Examples, Comparative Examples>
Examples and comparative examples will be described below, but the present invention is not limited to these examples. Examples 1 and 2 are working examples, and examples 3 and 5 are comparative examples.

[Example 1]
In Example 1, a laminated glass for evaluation LG1 having the same structure as the laminated glass for vehicle windows 10 was produced. First, the curved functional film 15 was produced by preliminarily bending the functional film 15X. Specifically, molds 101 and 102 having double curved shapes made of soda-lime glass were prepared. After that, as a first lamination step, a light control film is placed between the molds 101 and 102 as the functional film 15X, and the laminate A (first A laminate) was formed. The dimensions of the molding die 101 and the molding die 102 were each 300 mm long×300 mm wide×2.0 mm thick. The vertical and horizontal dimensions are values measured along the major surfaces. As for the light control film, a transparent conductive layer and a liquid crystal layer having a light control function were provided between two PET films having a glass transition temperature Tg of about 90° C. and a thickness of 50 μm. The dimensions of the light control film before bending were 250 mm long×250 mm wide×120 μm thick.

Next, the laminate A is placed in a resin bag and placed in a vacuum device, the vacuum device is evacuated to a gauge pressure of -70 kPa or less, and held at room temperature for 5 to 10 minutes to remove the resin bag. evacuated. After that, the laminate A put in the resin bag is taken out from the vacuum apparatus, and as a molding step, the laminate A is placed in the oven while still in the resin bag, and the inside of the oven is set to atmospheric pressure and a temperature of about 150°C ( T ₁ =150° C.) and held for 30 minutes or longer. After that, the temperature was returned to room temperature, the laminate A was taken out from the resin bag, and force was applied to the laminate A to separate the molds 101 and 102 and remove the functional film 15X (curved functional film 15). A curved functional film 15 curved roughly along the shapes of the molds 101 and 102 was completed.

Next, a laminated glass for evaluation LG1 was produced using the functional bendable film 15 taken out of the resin bag. Specifically, a compound-shaped glass plate 11 that becomes an inner plate (vehicle-inside glass plate) when made into laminated glass, a compound-shaped glass plate 12 that becomes an outer plate (vehicle-exterior glass plate), and a first intermediate A film 131 and a second intermediate film 132 were prepared. The dimensions of the glass plate 11 and the glass plate 12 were 300 mm long×300 mm wide×2.0 mm thick. The bending depths of the glass plate 11 and the glass plate 12 were both 7.5 mm in the shallow direction and 17.5 mm in the deep direction. The dimensions of the first intermediate film 131 were 300 mm long×300 mm wide×0.38 mm film thickness, and the dimensions of the second intermediate film 132 were 300 mm long×300 mm wide×0.76 mm film thickness. PVB was used for the first intermediate film 131 and the second intermediate film 132 .

Then, as a second lamination step, the glass plate 11, the glass plate 12, the first intermediate film 131, and the second intermediate film 132 are laminated in the order shown in FIG. (Second laminate) was produced. Next, a rubber channel was attached to the periphery of the laminate B. Then, as a first pressure-bonding step, the laminated body B is placed in an oven while the rubber channel is kept at a gauge pressure of −100 kPa or more and −65 kPa or less by a vacuum pump, and the temperature is about 110° C. (T ₂ =110° C.) for about 40° C. It was held for a minute and the laminate B was adhered. Next, as a second pressure-bonding step, the laminate B is pressurized and heated under conditions of an absolute pressure of 0.6 MPa or more and 1.3 MPa or less and a temperature of about 135 ° C. (T ₃ = 135 ° C.) for 20 minutes or more. A laminated glass LG1 was produced. That is, the maximum temperature T _max in the steps after the molding step was T ₃ =135°C.

[Example 2]
In Example 2, a laminated glass for evaluation LG2 having the same structure as the laminated glass for vehicle windows 10 was produced. First, in the same manner as in Example 1, except that the temperature inside the oven was set to approximately 120° C. (T ₁ =120° C.) in the molding step, a curved functional film 15 curved approximately along the shapes of the molds 101 and 102 was obtained. rice field.

Next, EVA having a length of 300 mm, a width of 300 mm, and a film thickness of 0.40 mm was used as the first intermediate film 131 and the second intermediate film 132 . Then, as a second lamination step, the glass plate 11, the glass plate 12, the first intermediate film 131, and the second intermediate film 132 are laminated in the order shown in FIG. (Second laminate) was produced. Next, a rubber channel was attached to the periphery of the laminate C. Then, as a first pressure-bonding step, the laminated body C is placed in an oven while the rubber channel is kept at a gauge pressure of −100 kPa or more and −65 kPa or less by a vacuum pump, and the temperature is about 110° C. (T ₂ =110° C.) for about 40° C. The laminated body C was adhered to prepare a laminated glass LG2 for evaluation. Note that Example 2 does not include the second crimping step. That is, the maximum temperature T _max in the steps after the molding step was T ₂ =110°C.

[Example 3]
In Example 3, a laminated glass for evaluation LG3 having the same structure as the laminated glass for vehicle windows 10 was produced. A laminated glass for evaluation LG3 was produced in the same manner as in Example 1, except that the temperature in the oven was set to about 120° C. (T ₁ =120° C.) in the molding step.

[Example 4]
In Example 4, a laminated glass for evaluation LG4 having the same structure as the laminated glass for vehicle windows 10 was produced. First, as in Example 1, as the first lamination step, a laminate A was formed by laminating the mold 101, the functional film 15X, and the mold 102. As shown in FIG.

Next, the laminate A is placed in a resin bag and placed in a vacuum device, the vacuum device is evacuated to a gauge pressure of -70 kPa or less, and held at room temperature for 5 to 10 minutes to remove the resin bag. evacuated. After that, the laminate A put in the resin bag was taken out from the vacuum apparatus, and as a molding step, the laminate A was placed in the autoclave while being held in the resin bag and supported by a predetermined method. Pressurized and heated at 6 MPa or more and 1.3 MPa or less and a temperature of 135° C. (T ₁ =135° C.) for 20 minutes or more. After that, the temperature was returned to room temperature, the laminate A was taken out from the resin bag, and the functional films 15X were removed from the molds 101 and 102 . A curved functional film 15 curved roughly along the shapes of the molds 101 and 102 was completed.

Next, laminated glass for evaluation LG4 was produced in the same manner as in Example 1 using the curved functional film 15 taken out of the resin bag. At this time, the same glass plate 11, glass plate 12, first intermediate film 131, and second intermediate film 132 as in Example 1 were used.

[Example 5]
In Example 5, a laminated glass for evaluation LG5 having the same structure as the laminated glass for vehicle windows 10 was produced. In Example 5, a laminated glass for evaluation LG5 was produced in the same manner as in Example 1 except that the pre-bending step was not performed. That is, the functional film 15X was used without being formed into the curved functional film 15. FIG.

[Evaluation of Examples 1 to 5]
Next, the laminated glasses for evaluation LG1 to LG5 produced in Examples 1 to 5 were evaluated for the presence or absence of wrinkles in the functional bendable film 15, and a comprehensive evaluation was made based on the results.

例１～例５の評価結果を機能フィルム１５Ｘの予備曲げの条件と共に表１にまとめた。表１の例５のように機能フィルム１５Ｘの予備曲げを行わないと、機能フィルム１５Ｘの外周の各辺から機能フィルム１５Ｘの内側に向かって約１０ｍｍの視認可能なしわが生じ、しわの評価はＣとなった。
また、例３及び例４のように、予備曲げ温度が圧着温度以下の条件で、湾曲機能フィルム１５の外周の各辺から湾曲機能フィルム１５の内側に向かって、例３では約３ｍｍ、例４では約２．５ｍｍの視認可能なしわが生じ、しわの評価はＣとなった。なお、例３及び例４において、予備圧着後かつ本圧着前には湾曲機能フィルム１５に視認可能なしわの発生が認められなかった。
これに対して、例１及び例２のように、予備曲げ温度が圧着温度より高い条件で機能フィルム１５Ｘの予備曲げを行って湾曲機能フィルム１５を作製することで、しわは許容範囲となり、しわの評価はＡとなった。なお、例１おいて、予備圧着後かつ本圧着前には湾曲機能フィルム１５に視認可能なしわの発生が認められなかった。 <Wrinkles>
The laminated glass for evaluation was visually observed for the presence or absence of wrinkles in the functional film at the periphery along the entire periphery, and evaluated according to the following criteria.
A: No visible wrinkles were observed in the functional film of the laminated glass for evaluation. (Within the acceptable range)
C: Occurrence of visible wrinkles is observed in at least a part of the functional film of the laminated glass for evaluation. (out of acceptable range)

The evaluation results of Examples 1 to 5 are summarized in Table 1 together with the pre-bending conditions of the functional film 15X. If the functional film 15X was not pre-bent as in Example 5 of Table 1, visible wrinkles of about 10 mm were generated from each side of the outer periphery of the functional film 15X toward the inner side of the functional film 15X, and the wrinkle evaluation was C. became.
Further, as in Examples 3 and 4, under the condition that the pre-bending temperature is equal to or lower than the pressure-bonding temperature, the distance from each side of the outer periphery of the functional bendable film 15 toward the inner side of the functional bendable film 15 is about 3 mm in Example 3, and about 3 mm in Example 4. In , visible wrinkles of about 2.5 mm were generated, and the wrinkle evaluation was C. In Examples 3 and 4, no visible wrinkles were observed in the bendable functional film 15 after the preliminary press-bonding and before the final press-bonding.
On the other hand, as in Examples 1 and 2, by pre-bending the functional film 15X under the condition that the pre-bending temperature is higher than the pressure-bonding temperature to produce the curved functional film 15, the wrinkles are within the allowable range. was rated A. In addition, in Example 1, no visible wrinkles were observed in the bendable functional film 15 after the preliminary press-bonding and before the final press-bonding.

As described above, unless the functional film is pre-bent under predetermined conditions, wrinkles are generated due to the stress generated in the functional film when the functional film follows the curved shape of the glass plate in the manufacturing process of laminated glass. . On the other hand, by pre-bending the functional film under predetermined conditions to prepare the curved functional film, the stress generated in the curved functional film before the manufacturing process of the laminated glass is relaxed, so that the laminated glass can be manufactured. Wrinkles are less likely to occur even after the manufacturing process.

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

10 Laminated glass for vehicle windows 11, 12 Glass plate 13 Intermediate film 131 First intermediate film 132 Second intermediate film 14 Shielding layer 15 Curved functional film 15X Functional films 101, 102 Forming molds 100, 120 Laminate

Claims (15)

A method for manufacturing a laminated glass for a vehicle window, in which first and second glass plates having curved main surfaces are bonded via an intermediate film, the method comprising:
a first lamination step of placing a functional film containing a resin film between first and second molds having a curved shape to form a first laminate;
a forming step of heating the functional film to a _first temperature T1 to form a curved functional film;
a second lamination step of disposing the intermediate film and the bendable functional film between the first and second glass plates to form a second laminate;
Having a first compression bonding step of crimping the second laminate at a _second temperature T2 for thermocompression bonding,
A method for manufacturing laminated glass for a vehicle window, wherein the _first temperature T1 is higher than the maximum temperature _Tmax , where _Tmax is the maximum temperature in a process subsequent to the molding process. The method for manufacturing a laminated glass for vehicle windows according to claim 1, wherein a difference between said _first temperature T1 and said maximum temperature _Tmax is 2°C or more. The method for producing a laminated glass for vehicle windows according to claim 1 or 2, wherein the _first temperature T1 is higher than the glass transition temperature Tg of the resin film. The method for manufacturing a laminated glass for a vehicle window according to any one of claims 1 to 3, wherein the _first temperature T1 is higher than 60°C and lower than or equal to 250°C. The method for manufacturing a laminated glass for a vehicle window according to any one of claims 1 to 4, wherein the _second temperature T2 is higher than the glass transition temperature Tg of the resin film. The vehicle window according to any one of claims 1 to 5, further comprising a step of cooling the bendable functional film to below the glass transition temperature Tg of the resin film between the molding step and the first compression step. A method for manufacturing laminated glass. The area of the main surface of the first mold is larger than the area of the first main surface of the functional film facing the main surface of the first mold,
7. The area of the main surface of the second mold is larger than the area of the second main surface of the functional film facing the main surface of the second mold. 2. The method for manufacturing the laminated glass for vehicle windows according to 1. The _second temperature T2 is 70° C. or higher and 120° C. or lower,
The method for manufacturing a laminated glass for a vehicle window according to any one of claims 1 to 7, wherein the first pressure bonding step performs pressure bonding at a gauge pressure of -100 kPa or more and -65 kPa or less. The method for manufacturing a laminated glass for a vehicle window according to any one of claims 1 to 8, wherein the minimum value of the radius of curvature of the main surfaces of the first and second molds is 500 mm or more and 100000 mm or less. The method for manufacturing a laminated glass for a vehicle window according to any one of claims 1 to 9, further comprising, after the first lamination step, a decompression step of holding the first laminate at a gauge pressure of -70 kPa or less. The vehicle according to any one of claims 1 to 10, wherein the functional film includes at least one of a light control film, an electrothermal film, a transparent display, a light emitting element mounting film, an infrared cut film, and a radio wave control film. A method for manufacturing laminated glass for windows. The method for manufacturing a laminated glass for a vehicle window according to any one of claims 1 to 11, wherein a power supply member is electrically connected to the peripheral edge portion of the functional film. After the first crimping step, a second crimping step of crimping at a _third temperature T3 at an absolute pressure of 0.6 MPa or more and 1.3 MPa or less,
The method for manufacturing a laminated glass for a vehicle window according to any one of claims 1 to 12, wherein the _third temperature T3 is equal to or higher than the _second temperature T2 and lower than the _first temperature T1. After the first crimping step, a second crimping step of crimping at a _third temperature T3 at an absolute pressure of 0.6 MPa or more and 1.3 MPa or less,
The method for manufacturing a laminated glass for a vehicle window according to any one of claims 1 to 12, wherein the _third temperature T3 is lower than the _second temperature T2. The method for producing a laminated glass for vehicle windows according to claim 13 or 14, wherein the _third temperature T3 is higher than the glass transition temperature Tg of the resin film.

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