Method for manufacturing vehicular laminated glass and vehicle

Abstract

To provide a method for manufacturing a vehicular laminated glass, the method maintaining the quality of appearance of the glass and furthermore improving the yield of the glass.SOLUTION: A method for manufacturing a vehicular laminated glass in which a first glass plate and a second glass plate are joined to each other by an intermediate film is provide, the method includes a bonding step of bonding the first glass plate including at least a part of a first curvature, and a second glass plate including at least a second curvature larger than the first curvature through the intermediate film. In the bonding step, the second glass plate is deformed in such a manner that the second curvature becomes small, when bonding the first glass plate and the second glass plate through the intermediate film, and tensile stress in a circumferential direction is generated on the outer periphery of the main surface of the second glass plate.SELECTED DRAWING: Figure 9

Description

[Technical field]

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

[0002] Laminated glass, which has advantages such as high sound insulation, low shattering when broken, and low penetration by flying objects, is used for window glass in vehicles such as automobiles, aircraft, buildings, etc. Laminated glass is generally formed by bonding a pair of glass plates together with an interlayer film therebetween.

[0003] As an example of such laminated glass, Patent Document 1 discloses a laminated glass for vehicles in which two intermediate layers, a first intermediate layer and a second intermediate layer, are disposed between a pair of glass plates.

[0004] Patent Document 2 discloses a method for producing a laminated glass for vehicles in which a first glass plate having a first curvature and a second glass plate having a second curvature smaller than the first curvature are bonded together with an interlayer film. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-128738 A [Patent Document 2] International Publication No. 2022 / 224908 Summary of the Invention [Problem to be solved by the invention]

[0006] However, a pair of glass sheets are formed to have various curved shapes depending on the application, etc. Therefore, depending on the curvature and shape of the pair of glass sheets, when the pair of glass sheets are laminated together via an interlayer film, defects in lamination, such as cracks or defective appearance, may occur on the main surfaces of the glass sheets, resulting in a problem of reduced yield in the production of laminated glass.

[0007] An object of one aspect of the present invention is to provide a method for producing laminated glass for vehicles, which improves yield while maintaining the quality of appearance. [Means for solving the problem]

[0008] One aspect of the present invention is A method for producing a laminated glass for a vehicle in which a first glass plate and a second glass plate are bonded together with an interlayer film, comprising the steps of: a bonding step of bonding the first glass plate, at least a part of which has a first curvature, and the second glass plate, at least a part of which has a second curvature larger than the first curvature, via the interlayer film; The bonding step is a manufacturing method for laminated glass for vehicles, in which, when the first glass plate and the second glass plate are bonded together via the interlayer film, the second glass plate is deformed so that the second curvature becomes smaller, and a tensile stress is generated along a circumferential direction on an outer periphery of a main surface of the second glass plate. Effect of the Invention

[0009] According to the method for producing a laminated glass for vehicles according to one aspect of the present invention, it is possible to improve the yield while maintaining the quality in appearance. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a front view of an automobile equipped with a laminated glass for vehicles obtained by a method for producing a laminated glass for vehicles according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the laminated glass for vehicles shown in FIG. [Diagram 3]FIG. 2 is a partial cross-sectional view of the laminated glass for vehicles shown in FIG. [Figure 4] FIG. 2 is an explanatory diagram of the arrow height, central angle, and radius of curvature of the exterior glass sheet and the interior glass sheet. [Diagram 5] FIG. 2 is an explanatory diagram showing a state in which tensile stress is generated on the outer periphery of the interior glass sheet in a state in which the exterior glass sheet and the interior glass sheet are bonded together via an interlayer film. [Figure 6] FIG. 2 is an explanatory diagram showing a state in which tensile stress is generated on the outer periphery of the vehicle exterior glass sheet in a state in which the vehicle exterior glass sheet and the vehicle interior glass sheet are bonded together via an interlayer film. [Figure 7] 1 is a flowchart showing an example of a method for producing a laminated glass for vehicles according to a first embodiment of the present invention. [Figure 8] 1 is a flow chart showing an example of a flat glass plate preparation step (Step S11). [Figure 9] FIG. 11 is an explanatory diagram showing an example of a bonding step (step S13). [Figure 10] FIG. 11 is an explanatory diagram showing another example of the bonding step (step S13). [Figure 11] FIG. 4 is a plan view of a laminated glass for vehicles obtained by a method for producing a laminated glass for vehicles according to a second embodiment of the present invention. [Figure 12] FIG. 12 is a partial cross-sectional view of the laminated glass for vehicles shown in FIG. [Figure 13] 5 is a flowchart showing an example of a method for producing a laminated glass for vehicles according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail. In order to facilitate understanding of the description, the same components in each drawing are given the same reference numerals, and duplicated descriptions will be omitted. In addition, the scale of each member in the drawings may differ from the actual scale. In this specification, "~" indicating a numerical range means that the numerical values ​​before and after it are included as the lower and upper limits, unless otherwise specified.

[0012] <First embodiment> A method for producing a laminated glass for vehicles according to a first embodiment of the present invention, and a laminated glass for vehicles obtained by the production method will be described.

[0013] The laminated glass for vehicles includes window glass for automobiles such as a front glass (windshield), rear glass, side glass, roof glass, quarter glass, etc., window glass for transportation vehicles such as trains and locomotives, window glass for construction vehicles such as bulldozers, window glass for flying objects such as airplanes and helicopters, window glass for other special vehicles, etc. In this embodiment, a case where the laminated glass for vehicles is used as a front glass of an automobile will be described.

[0014] [Laminated glass for vehicles] The laminated glass for vehicles will now be described. Fig. 1 is a front view of an automobile equipped with a laminated glass for vehicles obtained by the method for producing laminated glass for vehicles according to this embodiment. As shown in Fig. 1, a laminated glass for vehicles 1A obtained by the method for producing laminated glass for vehicles according to this embodiment is used as a windshield of an automobile 100.

[0015] Fig. 2 is a plan view of the laminated glass for vehicles 1A shown in Fig. 1, and Fig. 3 is a partial cross-sectional view of the laminated glass for vehicles 1A shown in Fig. 1. In Fig. 2 and Fig. 3, one of the main surfaces of the laminated glass for vehicles 1A is the vehicle exterior side, and the other is the vehicle interior side. In Fig. 2, the front side is the vehicle exterior side, and the back side is the vehicle interior side. In Fig. 2, the longitudinal direction of the laminated glass for vehicles 1A corresponds to, for example, the vehicle width direction, but may also correspond to the vehicle vertical direction. In Fig. 3, the left side is the vehicle exterior side, and the right side is the vehicle interior side.

[0016] As shown in Fig. 2, the laminated glass for vehicles 1A is formed in a substantially trapezoidal shape in a front view, with rounded corners. As shown in Fig. 3, the laminated glass for vehicles 1A has a curved surface whose main surface is curved in a convex shape toward the outside of the vehicle, and has a predetermined curvature. The laminated glass for vehicles 1A may be curved so as to be convex toward the outside of the vehicle as a whole or in part. In this case, the exterior glass sheet 10 and the interior glass sheet 20 can be processed and curved to a predetermined curvature in one or more directions, respectively, by a bending forming process described later.

[0017] As shown in Fig. 3, the laminated glass 1A for vehicles has an exterior glass plate 10, which is a first glass plate, and an interior glass plate 20, which is a second glass plate, bonded together via an interlayer 30. The exterior glass plate 10 has a first surface 11, which is a main surface facing the exterior side of the vehicle, and a second surface 12, which is a main surface facing the interior side of the vehicle, and the interior glass plate 20 has a third surface 21, which is a main surface facing the exterior side of the vehicle, and a fourth surface 22, which is a main surface facing the interior side of the vehicle.

[0018] The material constituting the vehicle exterior glass plate 10 and the vehicle interior glass plate 20 (hereinafter, collectively referred to as glass plates) in the vehicle laminated glass 1A is preferably inorganic glass. Examples of inorganic glass include soda lime silicate glass, aluminosilicate glass, borate glass, lithium aluminosilicate glass, and borosilicate glass. The method for forming the glass plate made of inorganic glass is not particularly limited, but the glass plate is preferably formed by, for example, a float method. The glass plate may be unreinforced glass. Unreinforced glass is glass obtained by forming molten glass into a plate shape and slowly cooling it, and is not subjected to a reinforcement treatment such as an air-cooling reinforcement treatment or a chemical reinforcement treatment. By using unreinforced glass, even if the glass is broken by impact, it is difficult for net-like or spider web-like cracks to occur, and the visibility of the occupants can be secured even in the event of an accident.

[0019] The exterior glass sheet 10 and the interior glass sheet 20 may have the same thickness or different thicknesses. However, it is preferable that the exterior glass sheet 10 be thicker than the interior glass sheet 20.

[0020] The thickness of the exterior glass plate 10 is preferably 1.1 mm to 6.0 mm. The lower limit of the thickness of the exterior glass plate 10 is more preferably 1.5 mm or more, and even more preferably 2.0 mm or more. The upper limit of the thickness of the exterior glass plate 10 is more preferably 4.5 mm or less, and even more preferably 4.0 mm or less.

[0021] The thickness of the interior side glass sheet 20 is preferably 0.5 mm to 3.5 mm. The lower limit of the thickness of the interior side glass sheet 20 is more preferably 1.0 mm or more, and even more preferably 1.5 mm or more. The upper limit of the thickness of the interior side glass sheet 20 is more preferably 3.0 mm or less, and even more preferably 2.5 mm or less.

[0022] The overall thickness of the laminated glass for vehicles 1A may be 1.6 mm to 8.5 mm.

[0023] The difference in thickness between the exterior glass sheet 10 and the interior glass sheet 20 is preferably 0.7 mm or less, more preferably 0.6 mm or less, and further preferably 0.5 mm or less. When the difference is 0.7 mm or less, the exterior glass sheet 10 can exhibit its strength while the interior glass sheet 20 can be made thinner and lighter.

[0024] The arrow height of the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 may be appropriately selected depending on the curvature of the laminated glass to be designed, and is, for example, preferably 90 mm or more, and may be 100 mm or more, or may be 150 mm or more. The upper limit of the arrow height of the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 may be appropriately selected depending on the shape, size, etc. of the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20, as long as it is 2000 mm or less.

[0025] The arrow height is the maximum bending depth of the exterior side glass sheet 10 and the interior side glass sheet 20, as shown in Figure 4, and refers to the difference between the deepest position in the center of the main surface of the exterior side glass sheet 10 and the interior side glass sheet 20 and their ends.

[0026] The radius of curvature of the interior side glass plate 20 needs to be smaller than the radius of curvature of the exterior side glass plate 10, taking into account the thickness of the interlayer 30. For example, it is preferably 1 mm or more smaller than the radius of curvature of the exterior side glass plate 10, and may be 5 mm or more smaller, or may be 10 mm or more smaller.

[0027] The central angle with respect to the arc length of the vehicle exterior glass sheet 10 and the vehicle interior glass sheet 20 may be appropriately selected depending on the curvature of the laminated glass to be designed, and is, for example, preferably 110° or more, may be 115° or more, or may be 130° or more. The upper limit of the central angle may be 180° or less.

[0028] The central angle with respect to the arc length refers to the central angle of the radius of curvature of the arc length when the length in the width direction (horizontal direction in Figure 4) of the exterior side glass sheet 10 and the interior side glass sheet 20 is taken as the chord length, as shown in Figure 4.

[0029] The exterior glass sheet 10 and the interior glass sheet 20 may have the same configuration (material constituting the glass sheet, manufacturing method of the glass sheet, etc.) or may be different from each other.

[0030] When the interior-side glass sheet 20 is bonded to the exterior-side glass sheet 10 via the interlayer 30, it is pressed so as to increase the radius of curvature of the interior-side glass sheet 20. For this reason, in a state in which the exterior-side glass sheet 10 and the interior-side glass sheet 20 are bonded together via the interlayer 30, stress (hoop stress) is generated along the circumferential direction on the outer periphery of the main surface of the interior-side glass sheet 20.

[0031] FIG. 5 is an explanatory diagram showing a state in which a stress in a tensile direction (tensile stress) is generated on the outer periphery of the interior glass sheet 20 in a state in which the exterior glass sheet 10 and the interior glass sheet 20 are bonded together via the interlayer 30. As shown in FIG. 5, in the interior glass sheet 20, a tensile stress is generated along the circumferential direction on the outer peripheries of the third surface 21 and the fourth surface 22, which are the main surfaces on the exterior side of the vehicle. The tensile stress is preferably generated in a region up to 100 mm in the in-plane direction from the outer periphery of the main surface of the interior glass sheet 20. If the tensile stress is generated within the above-mentioned range, the effect of the manufacturing method for vehicle laminated glass according to this embodiment due to the tensile stress generated on the outer periphery of the main surface of the interior glass sheet 20 can be fully exhibited. In addition, in the interior glass sheet 20, a compressive stress (compressive stress) is generated in a direction perpendicular to the circumferential direction of the main surface.

[0032] Furthermore, in a state in which the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 are bonded together via the interlayer 30, a hoop stress may also be generated on the outer periphery of the main surface of the vehicle-exterior glass sheet 10, similar to that of the vehicle-interior glass sheet 20. When the vehicle-interior glass sheet 20 is bonded to the vehicle-exterior glass sheet 10 via the interlayer 30, the vehicle-interior glass sheet 20 is pressed so as to increase the radius of curvature thereof, and the vehicle-exterior glass sheet 10 may also be deformed so as to increase its radius of curvature slightly. In this case, a hoop stress may also be generated on the outer periphery of the main surface of the vehicle-exterior glass sheet 10.

[0033] FIG. 6 is an explanatory diagram showing a state in which tensile stress occurs on the outer periphery of the vehicle-exterior glass sheet 10 in a state in which the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 are bonded together via the interlayer 30. As shown in FIG. 6, tensile stress may also occur in the vehicle-exterior glass sheet 10 along the circumferential direction on the outer periphery of the first surface 11 and the second surface 12, which are the main surfaces on the vehicle exterior side. The tensile stress is preferably generated in a region up to 100 mm in the in-plane direction from the outer periphery of the main surface of the vehicle-exterior glass sheet 10. If the tensile stress occurs within the above-mentioned range, the effect of this embodiment due to the tensile stress generated on the outer periphery of the main surface of the vehicle-exterior glass sheet 10 can be fully exhibited. In addition, compressive stress may occur in the vehicle-exterior glass sheet 10 in a direction perpendicular to the circumferential direction of the main surface.

[0034] The intermediate film 30 is disposed between the vehicle exterior glass plate 10 and the vehicle interior glass plate 20. The intermediate film 30 bonds the vehicle exterior glass plate 10 and the vehicle interior glass plate 20. The material of the intermediate film 30 is not particularly limited, but is preferably a thermoplastic resin. Examples of the thermoplastic resin include conventionally used thermoplastic resins 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, and ionomer resins. In addition, a resin composition containing a generally known modified block copolymer hydrogenated product described in, for example, Japanese Patent No. 6065221 can also be preferably used. Among these, a plasticized polyvinyl acetal resin is preferably used because it has an excellent balance of various performances such as transparency, weather resistance, strength, adhesive strength, penetration resistance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. The above thermoplastic resins may be used alone or in combination of two or more. The term "plasticized" in the plasticized polyvinyl acetal resin means that the resin is plasticized by adding a plasticizer. The same applies to other plasticized resins.

[0035] The intermediate film 30 may be a resin that does not contain a plasticizer, such as an ethylene-vinyl acetate copolymer resin.

[0036] 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 resin (PVB) obtained by reacting PVA with n-butylaldehyde. In particular, PVB is a suitable material 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. The above resins may be used alone or in combination of two or more kinds.

[0037] The thickness of the interlayer film 30 may be appropriately selected depending on the shape of the vehicle laminated glass 1A, and is preferably 2.0 mm or less, and may be 1.6 mm or less, or may be 1.0 mm or less, for example. The lower limit of the thickness of the interlayer film 30 may be any value that can exhibit the function of bonding the vehicle exterior glass sheet 10 and the vehicle interior glass sheet 20 together, and may be, for example, 0.3 mm or more.

[0038] The thickness of the interlayer film 30 means the thickness from the interface (second surface 12) of the interlayer film 30 with the vehicle exterior glass sheet 10 to the interface (third surface 21) of the interlayer film 30 with the vehicle interior glass sheet 20 when no display member such as a light control panel is sandwiched between the interlayer film 30. When a display member is sandwiched between the interlayer film 30, the thickness of the interlayer film 30 means the thickness of the interlayer film 30 only, excluding the thickness of the display member. In other words, the thickness of the interlayer film 30 means the length obtained by subtracting the thickness of the display member from the thickness from the interface (second surface 12) of the interlayer film 30 with the vehicle exterior glass sheet 10 to the interface (third surface 21) of the interlayer film 30 with the vehicle interior glass sheet 20.

[0039] A light-shielding layer may be provided on the periphery of the laminated glass for vehicles 1A to protect a sealant or the like that adheres and holds the laminated glass for vehicles 1A to the vehicle body. The light-shielding layer may be formed, for example, by applying a ceramic color paste of a low brightness color such as black, gray, or brown, which contains a meltable glass frit containing a black pigment, and then firing the paste. The light-shielding layer may be formed on the periphery of one or more of the second surface 12, the third surface 21, and the fourth surface 22 (FIG. 3) of the laminated glass for vehicles 1A, preferably on at least one of the second surface 12 and the fourth surface 22. The light-shielding layer may be provided over a distance of 10 mm to 300 mm from the peripheral edge of the glass plate.

[0040] [Method of manufacturing laminated glass for vehicles] Next, a method for producing a laminated glass for vehicles according to the first embodiment of the present invention will be described. Fig. 7 is a flow chart showing an example of a method for producing a laminated glass for vehicles according to this embodiment. As shown in Fig. 7, in the method for producing a laminated glass for vehicles according to this embodiment, a flat glass sheet is prepared (flat glass sheet preparation step: step S11).

[0041] In the flat glass plate preparation process (step S11), as shown in FIG. 8, a long ribbon-shaped glass plate is manufactured by a float method, a roll-out method or the like (strip glass plate manufacturing process: step S111), the ribbon-shaped glass plate is slowly cooled (strip cooling process: step S112), a blank plate is cut out from the ribbon-shaped glass plate (cutting process: step S113), the blank plate is cut to the desired outline (cutting process: step S114), chamfered (chamfering process: step S115), washed (washing process: step S116), and a light-shielding layer is printed (printing process: step S117).

[0042] These steps (step S111) to (step S117) are generally performed in manufacturing a glass sheet, and therefore details of each step will be omitted. The order of these steps (step S111) to (step S117) may be partially interchanged. Furthermore, some of these steps (step S111) to (step S117) may be changed or omitted, and other steps may be included between any of the steps (step S111) to (step S117). For example, one or more additional cleaning steps other than the cleaning step (step S116) may be included between any of the steps from the annealing step (step S112) to the chamfering step (step S115).

[0043] Next, as shown in FIG. 7, the flat glass sheet prepared in the flat glass sheet preparation step (step S11) is bent (bending step: step S12).

[0044] In the bending process (step S12), the flat glass sheet is curved by heating it to near its softening point or above its softening point. This results in two glass sheets (the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20) that are convexly curved in one direction. The vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 each have compressive stress in a direction parallel to the circumferential direction of their respective main surfaces at their most peripheral edges.

[0045] The bending may be gravity bending, in which a flat glass sheet is placed on a ring mold and bent by its own weight in a heating furnace, or press bending, in which the flat glass sheet is sandwiched between a ring mold (lower mold) and a press mold (upper mold) and pressed, or a combination of these.

[0046] The two flat glass sheets may be bent separately. The two flat glass sheets are bent, for example, so as to be convex downward (vertically downward).

[0047] The bending may be a single-bend bending in which a flat glass sheet is bent in only one direction, for example, only in the width direction or the up-down direction of the automobile when the sheet is attached to an opening of the automobile, or a multiple-bend bending in which the sheet is bent in both the width direction and the up-down direction of the automobile.

[0048] The heating temperature of the flat glass sheet during bending may be 550°C to 700°C.

[0049] The radii of curvature of the two glass sheets (the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20) obtained by the bending process (step S12) depend on the sizes of the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20, and may be, for example, 100 mm to 10,000 mm. The two glass sheets (the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20) are shaped so that the radius of curvature of the vehicle-exterior glass sheet 10 in the vehicle laminated glass 1A is larger than the radius of curvature of the vehicle-interior glass sheet 20. By bending, the vehicle-exterior glass sheet 10 includes a first curvature in at least a part of its main surfaces (the first surface 11 and the second surface 12), and the vehicle-interior glass sheet 20 includes a second curvature larger than the first curvature in at least a part of its main surfaces (the third surface 21 and the fourth surface 22).

[0050] The magnitudes of the first curvature and the second curvature are not particularly limited as long as the second curvature is larger than the first curvature, and can be appropriately selected depending on the size, shape, etc. of the exterior side glass sheet 10 and the interior side glass sheet 20.

[0051] The regions of the first curvature and the second curvature are not particularly limited and can be appropriately selected depending on the size, shape, etc. of the exterior side glass sheet 10 and the interior side glass sheet 20. The first curvature and the second curvature may be formed on the entire main surfaces of the exterior side glass sheet 10 and the interior side glass sheet 20, or may be formed only on the outer periphery and the surrounding region of the exterior side glass sheet 10 and the interior side glass sheet 20.

[0052] The maximum distance (gap amount) between the vehicle-exterior glass plate 10 and the vehicle-interior glass plate 20 before bonding the two plates is preferably 2.7 mm or less, more preferably 2.3 mm or less, and further preferably 1.7 mm or less. If the gap amount is 2.7 mm or less, the vehicle-interior glass plate 20 can be easily bonded to the vehicle-exterior glass plate 10 via the interlayer 30.

[0053] 7, the two glass sheets (the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20) bent in the bending process (step S12) are bonded together via the interlayer 30 (bonding process: step S13), thereby obtaining a laminated glass for vehicles 1A.

[0054] In the lamination step (step S13), as shown in FIG. 9, when two curved glass sheets (the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20) are laminated together, an interlayer film 30 is disposed between the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 (see FIG. 9(a)), and the vehicle-interior glass sheet 20 is moved toward the vehicle-exterior glass sheet 10 together with the interlayer film 30 (see FIG. 9(b)). After the center of the third surface 21 of the vehicle-interior glass sheet 20 is brought into contact with the center of the second surface 12 of the vehicle-exterior glass sheet 10 via the interlayer film 30 (see FIG. 9(c)), the end of the vehicle-interior glass sheet 20 is pressed toward the vehicle-exterior glass sheet 10, and the vehicle-interior glass sheet 20 is deformed in a direction in which its curvature becomes smaller (a direction in which the radius of curvature becomes larger) (see FIG. 9(d)). This allows the two glass sheets to be laminated together without generating any gap between the vehicle-exterior glass sheet 10, the vehicle-interior glass sheet 20, and the interlayer film 30.

[0055] Furthermore, since the exterior side glass sheet 10 and the interior side glass sheet 20 are not deformed in a direction in which their curvature increases (a direction in which their radius of curvature decreases), it is possible to prevent stress from concentrating on the principal surfaces of the exterior side glass sheet 10 and the interior side glass sheet 20. This makes it possible to prevent cracks from occurring on the principal surfaces, particularly the first surface 11 and the fourth surface 22, of the exterior side glass sheet 10 and the interior side glass sheet 20.

[0056] Furthermore, when the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 are bonded together via the interlayer 30, the vehicle-interior glass sheet 20 is deformed in a direction that reduces the curvature of the glass sheet, and as a result, tensile stress, which is a hoop stress, is generated in the circumferential direction of the principal surfaces (the third surface 21 and the fourth surface 22) of the vehicle-interior glass sheet 20, as shown in Fig. 5. As a result, the principal surfaces are bonded together from the center thereof, and air can be pushed outward without remaining on the bonding surface.

[0057] The stress applied to the end of the interior glass sheet 20 toward the exterior glass sheet 10 may be appropriately selected depending on the size, curvature, etc. of the interior glass sheet 20. 2 ~3N / mm 2 When the stress is within the above-mentioned preferred range, the vehicle-interior glass sheet 20 can be bonded to the vehicle-exterior glass sheet 10 via the interlayer 30 while preventing insufficient embedding of the interlayer 30 between the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20.

[0058] Furthermore, when bonding the interior-side glass sheet 20 to the exterior-side glass sheet 10 via the interlayer 30, only the edge of the interior-side glass sheet 20 may be pressed toward the exterior-side glass sheet 10, or, for example, the interior-side glass sheet 20 may be pressed toward the exterior-side glass sheet 10 from approximately the center of the fourth surface 22 of the interior-side glass sheet 20 toward the edge. This allows the interior-side glass sheet 20 to be bonded to the exterior-side glass sheet 10 via the interlayer 30 while pushing out internal air so as to prevent insufficient embedding of the interlayer 30 in the approximately center portion between the exterior-side glass sheet 10 and the interior-side glass sheet 20.

[0059] When bonding the vehicle-exterior glass plate 20 to the vehicle-exterior glass plate 10 via the interlayer 30, it is preferable to perform this in a vacuum state with a pressure of, for example, 100 Pa or less. If the pressure is equal to or less than the above-mentioned numerical value, it is possible to prevent air from remaining between the vehicle-exterior glass plate 10 and the vehicle-interior glass plate 20 and the interlayer 30 when bonding the vehicle-exterior glass plate 10 and the vehicle-interior glass plate 20 and the interlayer 30. This makes it possible to prevent insufficient embedding of the interlayer 30 between the vehicle-exterior glass plate 10 and the vehicle-interior glass plate 20, and to bond the vehicle-exterior glass plate 10 and the vehicle-interior glass plate 20 together via the interlayer 30.

[0060] The magnitude of the tensile stress generated in the circumferential direction of the main surface of the interior side glass sheet 20 depends on the degree of deformation of the interior side glass sheet 20 in the direction in which the curvature increases. For example, 2 ~3N / mm 2 If the tensile stress is within the above range, the glass sheet can be deformed without excessive stress being concentrated locally, and peeling from the edge portions can also be suppressed.

[0061] When the edge of the exterior glass plate 10 is pressed by the interior glass plate 20 through the intermediate film 30, causing the exterior glass plate 10 to deform in a direction that reduces the curvature, tensile stress is generated along the circumferential direction of the outer periphery of the main surfaces (first surface 11 and second surface 12) of the exterior glass plate 10, just like the interior glass plate 20, as shown in Figure 6.

[0062] In addition, in the bonding process (step S13), when bonding two curved glass plates (the vehicle exterior glass plate 10 and the vehicle interior glass plate 20) together, for example, as shown in Figure 10, the vehicle exterior glass plate 10 may be placed in advance on a support stand 40, and the vehicle exterior glass plate 10 and the vehicle interior glass plate 20 may be bonded together via an intermediate film 30.

[0063] That is, after the exterior-side glass sheet 10 is placed on the support base 40 in advance, the interlayer 30 is placed between the exterior-side glass sheet 10 and the interior-side glass sheet 20 in the same manner as described above (see Fig. 10(a)), and the interior-side glass sheet 20 together with the interlayer 30 is moved towards the exterior-side glass sheet 10 (see Fig. 10(b)). After the centre of the third surface 21 of the interior-side glass sheet 20 is brought into contact with the centre of the second surface 12 of the exterior-side glass sheet 10 via the interlayer 30 (see Fig. 10(c)), the edge of the interior-side glass sheet 20 is pressed towards the exterior-side glass sheet 10 to deform the exterior-side glass sheet 10 in a direction that reduces its curvature (see Fig. 10(d)).

[0064] The lamination step (step S13) may include a step of preliminarily bonding the interlayer 30 sandwiched between two glass sheets (the vehicle exterior glass sheet 10 and the vehicle interior glass sheet 20) by a rubber pack method or a nip roller method (preliminary bonding step), and a step of subsequently heating and pressurizing in an autoclave for full bonding (full bonding step). All steps of the preliminary bonding step are similar to those described above except for the heating conditions, so details will be omitted.

[0065] As described above, the manufacturing method of the laminated glass for vehicles according to this embodiment includes a bonding step (step S13). In the bonding step (step S13), when the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 are bonded together with the interlayer film 30 interposed therebetween, the vehicle-interior glass sheet 20 is deformed so as to reduce the second curvature. As a result, when the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 are bonded together with the interlayer film 30 interposed therebetween, the interlayer film 30 is not insufficiently embedded between the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20, and the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 can be bonded together without generating any gaps between them and the interlayer film 30.

[0066] The interior glass sheet 20 has a second curvature larger than the first curvature of the exterior glass sheet 10. Therefore, in the bonding step (step S13), the interior glass sheet 20 is deformed so as to reduce the second curvature, thereby generating tensile stress along the circumferential direction on the outer periphery of the main surface (the third surface 21 and the fourth surface 22) of the interior glass sheet 20. That is, the interior glass sheet 20 is spread and bonded to the exterior glass sheet 10 via the intermediate film 30. This prevents the tensile stress generated along the circumferential direction on the outer periphery of the main surface of the interior glass sheet 20 (the second glass sheet) from being excessively concentrated locally on the main surface of the interior glass sheet 20 (particularly, the central part of the main surface). Since excessive stress is prevented from being concentrated locally on the main surface of the interior glass sheet 20, the main surface of the interior glass sheet 20 becomes less likely to crack. This prevents damage such as cracks from occurring on the main surfaces of the exterior glass plate 10 and the interior glass plate 20, particularly in the approximate central portions of the first surface 11 and the fourth surface 22, and prevents poor appearance of the vehicle laminated glass 1A.

[0067] Therefore, according to the method for producing a laminated glass for vehicles according to this embodiment, it is possible to improve the yield of the laminated glass for vehicles 1A produced while maintaining the quality of the appearance of the laminated glass for vehicles 1A.

[0068] Furthermore, in the bonding step (step S13), when bonding the vehicle-exterior glass plate 10 and the vehicle-interior glass plate 20 together via the interlayer 30, it is only necessary to deform the vehicle-interior glass plate 20 so as to reduce the second curvature. Therefore, the vehicle-exterior glass plate 10 and the vehicle-interior glass plate 20 are easily bonded together via the interlayer 30, and misalignment is unlikely to occur in the bonding positions of the vehicle-exterior glass plate 10 and the vehicle-interior glass plate 20. Therefore, the method for manufacturing laminated glass for vehicles according to this embodiment enables the vehicle-exterior glass plate 10 and the vehicle-interior glass plate 20 to be bonded together with high precision via the interlayer 30.

[0069] In the manufacturing method for laminated glass for vehicles according to this embodiment, the arrow height of the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 is preferably 90 mm or more. As a result, the manufacturing method for laminated glass for vehicles according to this embodiment improves the yield of laminated glass for vehicles to be manufactured while maintaining the appearance quality of the laminated glass for vehicles 1A, even if the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 are glass sheets having a deep arrow height of 90 mm or more.

[0070] In the manufacturing method for laminated glass for vehicles according to this embodiment, the radius of curvature of the interior side glass sheet 20 is preferably smaller than the radius of curvature of the exterior side glass sheet 10 by at least 1 mm. This makes it possible for the manufacturing method for laminated glass for vehicles according to this embodiment to more reliably bond the exterior side glass sheet 10 and the interior side glass sheet 20 together via the interlayer film 30, taking into account the thickness of the interlayer film 30. Thus, the manufacturing method for laminated glass for vehicles according to this embodiment can manufacture laminated glass for vehicles while further suppressing the occurrence of defects in the appearance of the laminated glass for vehicles 1A.

[0071] In the method for producing laminated glass for vehicles according to this embodiment, the thickness of the interlayer film 30 is preferably 2.0 mm or less. This allows the exterior glass sheet 10 and the interior glass sheet 20 to be bonded together more easily without generating gaps between the sheet 10 and the interlayer film 30. Therefore, the method for producing laminated glass for vehicles according to this embodiment allows the exterior glass sheet 10 and the interior glass sheet 20 to be bonded together more reliably via the interlayer film 30. Therefore, the method for producing laminated glass for vehicles according to this embodiment can produce laminated glass for vehicles while further suppressing the occurrence of defects in the appearance of the exterior glass sheet 10 and the interior glass sheet 20.

[0072] In the manufacturing method for laminated glass for vehicles according to this embodiment, it is preferable that the thickness of the vehicle-exterior glass sheet 10 is greater than the thickness of the vehicle-interior glass sheet 20. This increases the strength of the vehicle-exterior glass sheet 10, thereby increasing the strength against external impact. Therefore, the manufacturing method for laminated glass for vehicles according to this embodiment can manufacture laminated glass for vehicles with higher strength.

[0073] In the manufacturing method for laminated glass for vehicles according to this embodiment, it is preferable that the thickness of the vehicle-exterior glass sheet 10 is 1.1 mm to 6.0 mm, and the thickness of the vehicle-interior glass sheet 20 is 0.5 mm to 3.5 mm. As a result, the vehicle-exterior glass sheet 10 can be made thicker than the vehicle-interior glass sheet 20, so that the vehicle-exterior glass sheet 10 ensures the rigidity required for the laminated glass for vehicles 1A, while the thickness of the vehicle-interior glass sheet 20 can be reduced, thereby reducing the weight of the laminated glass for vehicles 1A. Thus, according to the manufacturing method for laminated glass for vehicles according to this embodiment, the laminated glass for vehicles 1A can be manufactured with a good yield while ensuring the rigidity and reducing the weight of the laminated glass for vehicles 1A.

[0074] In the manufacturing method for laminated glass for vehicles according to this embodiment, the central angles with respect to the arc lengths of the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 are preferably 110° or more. As a result, the manufacturing method for laminated glass for vehicles according to this embodiment improves the yield of laminated glass for vehicles to be manufactured while maintaining the appearance quality of the laminated glass for vehicles 1A, even if the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 are glass sheets having central angles of 110° or more.

[0075] In the manufacturing method of the laminated glass for vehicles according to this embodiment, the difference in thickness between the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 is preferably 0.7 mm or less. Since the vehicle-exterior glass sheet 10 can be made thicker than the vehicle-interior glass sheet 20, if the difference in thickness between the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 is 0.7 mm or less, the laminated glass for vehicles 1A can be manufactured with a good yield while ensuring the rigidity of the laminated glass for vehicles 1A and reducing its weight.

[0076] In the manufacturing method for laminated glass for vehicles according to this embodiment, it is preferable that the maximum distance between the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 before bonding the vehicle-exterior glass sheet 10 and the vehicle-interior glass sheet 20 is 2.7 mm or less. As a result, the manufacturing method for laminated glass for vehicles according to this embodiment can reliably press the edge of the vehicle-interior glass sheet 20 against the vehicle-exterior glass sheet 10 via the interlayer 30 so that the radius of curvature of the vehicle-interior glass sheet 20 is large, and therefore the laminated glass for vehicles 1A can be easily manufactured.

[0077] <Second embodiment> A method for producing a laminated glass for vehicles according to a second embodiment of the present invention and a laminated glass for vehicles obtained by the method will be described. Note that detailed descriptions of the method and the laminated glass for vehicles obtained by the method that are common to the first embodiment will be omitted.

[0078] Fig. 11 is a plan view of a laminated glass for vehicles 1B obtained by the manufacturing method for laminated glass for vehicles according to this embodiment, and Fig. 12 is a partial cross-sectional view of the laminated glass for vehicles 1B shown in Fig. 11. The positional relationship between the vehicle exterior side and vehicle interior side of the main surfaces of the laminated glass for vehicles 1B in Figs. 11 and 12 is the same as in Figs. 2 and 3.

[0079] As shown in Fig. 11, the laminated glass for vehicles 1B has the same shape as the laminated glass for vehicles 1A. As shown in Fig. 12, the laminated glass for vehicles 1B has a second interlayer film 50 and a shielding layer 60 between the interior glass sheet 20 and the interlayer film 30, and is configured by bonding the exterior glass sheet 10 and the interior glass sheet 20 with the interlayer film 30, the second interlayer film 50, and the shielding layer 60 interposed therebetween.

[0080] The shielding layer 60 is attached to the surface of the interlayer 30 facing the interior side glass sheet 20, and is provided so as to be sandwiched between the interlayer 30 and the second interlayer 50. The shielding layer 60 may be attached to the third surface 21 of the interior side glass sheet 20, and is provided so as to be sandwiched between the interior side glass sheet 20 and the second interlayer 50.

[0081] The positions of the second interlayer film 50 and the shielding layer 60 are not limited to between the vehicle-interior glass sheet 20 and the interlayer film 30, and may be provided between the vehicle-exterior glass sheet 10 and the interlayer film 30 depending on the application, design, etc. of the vehicle laminated glass 1B. In this case, the second interlayer film 50 may be attached to the second surface 12 of the vehicle-exterior glass sheet 10, and the shielding layer 60 may be attached to the second surface 12 of the vehicle-exterior glass sheet 10 or to the surface of the interlayer film 30.

[0082] In addition, the vehicle laminated glass 1B has a second intermediate film 50 between the interior side glass plate 20 and the intermediate film 30, but it may not have the second intermediate film 50 and the shielding layer 60 may be sandwiched between the interior side glass plate 20 and the intermediate film 30.

[0083] The second interlayer film 50 is provided on the third surface 21 of the interior-side glass sheet 20, and is disposed between the interior-side glass sheet 20 and the interlayer film 30. The second interlayer film 50 bonds the interior-side glass sheet 20 and the interlayer film 30 together.

[0084] The material of the second intermediate film 50 is not particularly limited, and the same material as that of the intermediate film 30 may be used.

[0085] The thickness of the second interlayer film 50 may be appropriately selected depending on the shape of the vehicle laminated glass 1B and the like, and may be thinner than the interlayer film 30 or may be the same thickness as the interlayer film 30. The thickness of the second interlayer film 50 should be sufficient to bond the vehicle interior glass sheet 20 and the interlayer film 30 together, and is preferably 10 μm to 250 μm, more preferably 20 μm to 160 μm, and even more preferably 40 μm to 100 μm.

[0086] As shown in Fig. 11, the shielding layer 60 is provided on the periphery of the vehicle laminated glass 1B. The shielding layer 60 is provided so as to cover the periphery of the vehicle exterior glass sheet 10 and the vehicle interior glass sheet 20 in a plan view. The periphery refers to a range of 10 mm to 300 mm from the periphery of the vehicle exterior glass sheet 10 and the vehicle interior glass sheet 20. Therefore, the shielding layer 60 is provided over a range of 10 mm to 300 mm from the periphery of the vehicle exterior glass sheet 10 and the vehicle interior glass sheet 20. The shape and size of the shielding layer 60 are not particularly limited, and may be any shape and size depending on the arrangement of sensors and cameras present behind or around the vehicle laminated glass 1B.

[0087] The shielding layer 60 contains a pigment and can be formed, for example, by applying a printing composition that includes a pigment.

[0088] As the pigment, an inorganic or organic pigment is used. As the inorganic or organic pigment, it is preferable to use carbon black, iron oxide, polyaniline, perylene or spinel pigment. The pigment may be dispersed in a carrier fluid, such as water, alcohol or a mixture of alcohol and water. Furthermore, the pigment may contain a binder, such as polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyvinylpyrrolidone, polyacrylate, polyurethane or polystyrene acrylate. As the binder, it is preferable to use PVB, for example. Such a printing composition containing a pigment, a carrier fluid and a binder is also called a "printing ink" or "ink".

[0089] Among the printing inks, water-based printing inks (water-based printing inks) are preferred over organic solvent-based printing inks, since the use of water-based printing inks can prevent the shielding layer 60 from swelling or dissolving and can prevent defects in the shielding layer 60.

[0090] When the shielding layer 60 is thin, or when the printing ink dries quickly so that the solvent contained in the printing ink does not migrate into the intermediate film 30 or the second intermediate film 50, it is preferable to use a printing ink based on an organic solvent.

[0091] The binder used in the printing ink is preferably low molecular weight PVB, which makes it easier to ensure good compatibility with the second interlayer film 50 containing PVB.

[0092] The printing inks can be applied, for example, by offset printing, rotogravure printing, flexographic printing or screen printing.

[0093] In order to optimize adhesion of printing ink to the surface of the second interlayer 50, the surface of the second interlayer 50 may be activated, such as by corona treatment, prior to application of the shielding layer 60.

[0094] The thickness of the shielding layer 60 is not particularly limited and may be any appropriate thickness depending on the opacity required for the shielding layer 60, and may be, for example, 1 μm to 50 μm.

[0095] [Method of manufacturing laminated glass for vehicles] Next, a method for manufacturing a laminated glass for vehicles according to a second embodiment of the present invention will be described. FIG. 13 is a flow chart showing an example of a method for manufacturing a laminated glass for vehicles according to the present embodiment. As shown in FIG. 13, in the method for manufacturing a laminated glass for vehicles according to the present embodiment, a flat glass sheet is prepared (flat glass sheet preparation step: step S21), and the flat glass sheet prepared in the flat glass sheet preparation step (step S21) is bent (bending step: step S22). The flat glass sheet preparation step (step S21) and the bending step (step S22) are similar to the flat glass sheet preparation step (step S11) and the bending step (step S12) in the method for manufacturing a laminated glass for vehicles according to the first embodiment shown in FIG. 7, and therefore details will be omitted.

[0096] Next, of the two glass sheets (the exterior glass sheet 10 and the interior glass sheet 20) bent in the bending process (step S22), a second intermediate film 50 is bonded to the third surface 21 of the interior glass sheet 20 (bonding process of the second intermediate film 50: step S23).

[0097] The method for bonding the second interlayer film 50 to the third surface 21 of the interior-facing glass sheet 20 is not particularly limited, and a general bonding method may be used.

[0098] Next, the shielding layer 60 is formed on the periphery of the second intermediate film 50 (shielding layer 60 forming process: step S24).

[0099] The shielding layer 60 may be formed by applying the above-described printing composition to the periphery of the second interlayer 50 using conventional application methods.

[0100] Next, the vehicle exterior glass sheet 10 bent in the bending process (step S22) and the vehicle interior glass sheet 20 having the second interlayer film 50 and the shielding layer 60 provided on the third surface 21 are bonded together via the interlayer film 30 (bonding process: step S25). In this way, a laminated glass for vehicles 1B is obtained.

[0101] The lamination step (step S25) can be performed in the same manner as the lamination step (step S13) of the manufacturing method for laminated glass for vehicles according to the first embodiment shown in Figure 7, except that a second intermediate film 50 and a shielding layer 60 are provided on the third surface 21 of the interior glass plate 20 before the exterior glass plate 10 and the interior glass plate 20 are laminated together with the intermediate film 30 interposed therebetween.

[0102] The manufacturing method of the laminated glass for vehicles according to this embodiment includes a bonding step of the second interlayer film 50 (step S23), a forming step of the shielding layer 60 (step S24), and a bonding step (step S25). In the bonding step of the second interlayer film 50 (step S23) and the forming step of the shielding layer 60 (step S24), the second interlayer film 50 and the shielding layer 60 are provided on the third surface 21 of the interior side glass sheet 20. In the bonding step (step S25), when the exterior side glass sheet 10 and the interior side glass sheet 20 having the second interlayer film 50 and the shielding layer 60 provided on the third surface 21 are bonded together via the interlayer film 30, the interior side glass sheet 20 is deformed so as to reduce the second curvature. As a result, when the vehicle exterior glass plate 10 and the vehicle interior glass plate 20 are bonded together with the intermediate film 30, the second intermediate film 50, and the shielding layer 60 interposed therebetween, there is no insufficient embedding of the intermediate film 30, the second intermediate film 50, and the shielding layer 60, and the vehicle exterior glass plate 10 and the vehicle interior glass plate 20 can be bonded together without any gaps being generated between the intermediate film 30, the second intermediate film 50, and the shielding layer 60.

[0103] The interior-side glass sheet 20 has a second curvature larger than the first curvature of the exterior-side glass sheet 10. Therefore, in the bonding step (step S25), the interior-side glass sheet 20 is deformed so as to reduce the second curvature, thereby generating tensile stress along the circumferential direction on the outer periphery of the main surfaces (the third surface 21 and the fourth surface 22) of the interior-side glass sheet 20. As a result, like the manufacturing method of the laminated glass for vehicles according to the first embodiment, damage such as cracks is prevented from occurring in the main surfaces of the exterior-side glass sheet 10 and the interior-side glass sheet 20, particularly in the approximate central portions of the first surface 11 and the fourth surface 22, thereby preventing appearance defects of the laminated glass for vehicles 1B.

[0104] Therefore, according to the manufacturing method of the laminated glass for vehicles according to this embodiment, even if the second interlayer film 50 and the shielding layer 60 are provided on the third surface 21 of the interior side glass sheet 20, the yield of the laminated glass for vehicles 1B can be improved while maintaining the appearance quality of the laminated glass for vehicles 1B.

[0105] As described above, the manufacturing method of the laminated glass for vehicles according to each of the above-mentioned embodiments can improve the yield of the laminated glass for vehicles manufactured while maintaining the quality of the appearance, so that the laminated glass for vehicles 1A and 1B are preferably windshields. The manufacturing method of the laminated glass for vehicles according to the present embodiment may be used for automobile window glass such as rear glass, side glass, roof glass, quarter glass, etc., window glass for transportation vehicles such as trains and locomotives, window glass for construction vehicles such as bulldozers, window glass for aircraft such as airplanes and helicopters, window glass for other special vehicles, etc. In particular, the manufacturing method of the laminated glass for vehicles according to the present embodiment is preferably used for windshields, roof glass, etc. of vehicles that have many curved shapes and a large degree of curvature.

[0106] Although the embodiment has been described above, the above embodiment is presented as an example, and the present invention is not limited to the above embodiment. The above embodiment can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. EXAMPLES

[0107] The following examples are provided to further explain the embodiments, but the embodiments are not limited to these examples. Examples 1 to 10 are working examples, and Examples 11 to 14 are comparative examples.

[0108] <Making laminated glass> [Example 1] (Production of the first glass sheet (outside glass sheet)) A rectangular glass plate (thickness 2 mm) in plan view was prepared as the first glass plate. The first glass plate was subjected to gravity bending while being heated, and warped so as to be curved convexly in the direction in which the first glass plate was to be placed. The radius of curvature of the first glass plate was 133 mm, the arrow height was 99 mm, the central angle was 150°, and the curvature was 751.9 × 10 -5 (1 / mm). (Production of the second glass sheet (inside glass sheet)) As the second glass plate, a glass plate similar to the first glass plate was prepared. The second glass plate was subjected to gravity bending while being heated, and warped so as to be convexly curved in the direction in which the second glass plate was placed. The radius of curvature of the second glass plate was 132 mm, the arrow height was 100 mm, the central angle was 152°, and the curvature was 757.6×10 -5 (1 / mm). (Making laminated glass) An interlayer film (PVB, thickness 0.8 mm) was placed between the first glass plate and the second glass plate, and the edge of the second glass plate was pressed against the first glass plate to deform the second glass plate so that its curvature became smaller. The first glass plate and the second glass plate were bonded together via the interlayer film to produce laminated glass.

[0109] [Example 2 to Example 14] In Examples 2 to 14, the same procedures as in Example 1 were carried out except that the conditions for the first glass plate and the second glass plate were changed to the values ​​shown in Tables 1 and 2, to prepare laminated glasses.

[0110] <Evaluation of laminated glass> (Lamination property) The appearance of the laminated glass was visually observed to confirm whether air bubbles were generated inside the laminated glass, and whether peeling from the interlayer film occurred on at least one of the lamination surfaces of the first and second glass sheets was evaluated based on the following evaluation criteria. The evaluation results are shown in Tables 1 and 2. If air bubbles were generated inside the laminated glass, a gap was generated between at least one of the lamination surfaces of the first and second glass sheets and the interlayer film, and it can be determined that peeling occurred between the lamination surface and the interlayer film. If no air bubbles were observed inside the laminated glass, it was determined that the lamination surfaces of the first and second glass sheets were not peeled from the interlayer film, and the lamination property was determined to be good. If air bubbles were observed inside the laminated glass, it was determined that at least one of the lamination surfaces of the first and second glass sheets was peeled from the interlayer film, and the lamination property was determined to be poor. Note that the presence or absence of peeling "-" in Examples 12 and 14 could not be evaluated due to cracks. (Evaluation Criteria) A: The bonding surfaces of the first glass plate and the second glass plate are not peeled off from the interlayer film. B: The bonding surface of the first glass plate or the second glass plate has peeled off from the interlayer film.

[0111] (Check for cracks) The appearance of the laminated glass was visually observed to check whether cracks had occurred on the surface of the first glass sheet or the second glass sheet, and evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 1 and 2. (Evaluation Criteria) A: There are no cracks on the surfaces of the first glass plate and the second glass plate. B: There is a crack on the surface of the first glass plate or the second glass plate.

[0112] [Table 1]

[0113] [Table 2]

[0114] As seen from Table 1, in Examples 1 to 10, the bonding surfaces of the first and second glass plates were not peeled off from the interlayer film, the bonding property was good, and no cracks were found on the surfaces of either the first or second glass plate. On the other hand, as seen from Table 2, in Examples 11 to 14, the bonding surfaces of the first or second glass plate were peeled off from the interlayer film, or cracks were found on the surfaces of the first or second glass plate.

[0115] Therefore, if the curvature of the second glass plate is made larger than the curvature of the first glass plate, and the first glass plate and the second glass plate are bonded together via an interlayer film while deforming the second glass plate so that its curvature is smaller, the first glass plate and the second glass plate are bonded together via the interlayer film to produce laminated glass for vehicles, it is possible to maintain the quality of the appearance and to improve the yield of the laminated glass for vehicles produced. [Explanation of symbols]

[0116] 1A, 1B Laminated glass for vehicles 10. Vehicle exterior glass panel (first glass panel) 11 Page 1 12 Side 2 20. Interior glass panel (second glass panel) 21 Page 3 22 Page 4 30 Interlayer 40 Support stand 50 Second intermediate film 60 Shielding layer 100 Automobiles

Claims

1. A method for producing a laminated glass for a vehicle in which a first glass plate and a second glass plate are joined together with an interlayer film, comprising the steps of: a bonding step of bonding the first glass plate, at least a part of which has a first curvature, and the second glass plate, at least a part of which has a second curvature larger than the first curvature, via the interlayer film; the bonding step includes, when bonding the first glass plate and the second glass plate with the interlayer film interposed therebetween, deforming the second glass plate so that the second curvature becomes smaller, and generating a tensile stress along a circumferential direction on an outer periphery of a main surface of the second glass plate.

2. The method for producing a laminated glass for a vehicle according to claim 1, wherein the arrow height of the first glass plate and the second glass plate is 90 mm or more.

3. 3. The method for producing a laminated glass for a vehicle according to claim 1, wherein a radius of curvature of the second glass plate is smaller than a radius of curvature of the first glass plate by 1 mm or more.

4. The method for producing a laminated glass for vehicles according to claim 1 or 2, wherein the thickness of the interlayer film is 2.0 mm or less.

5. The method for producing a laminated glass for a vehicle according to claim 1 or 2, wherein a thickness of the first glass plate is greater than a thickness of the second glass plate.

6. The thickness of the first glass plate is 1.1 mm to 6.0 mm; 3. The method for producing a laminated glass for a vehicle according to claim 1, wherein the second glass plate has a thickness of 0.5 mm to 3.5 mm.

7. 3. The method for producing a laminated glass for a vehicle according to claim 1, wherein a central angle with respect to an arc length of the first glass plate and the second glass plate is 110° or more.

8. 3. The method for producing a laminated glass for a vehicle according to claim 1, wherein a difference in thickness between the first glass plate and the second glass plate is 0.7 mm or less.

9. 3. The method for producing a laminated glass for a vehicle according to claim 1, wherein a maximum distance between the first glass plate and the second glass plate before the first glass plate and the second glass plate are bonded to each other is 2.7 mm or less.

10. 3. The method for producing a laminated glass for a vehicle according to claim 1, further comprising providing a shielding layer between either one of the first glass plate or the second glass plate and the interlayer film so as to cover peripheral edges of the first glass plate and the second glass plate in a plan view.

11. The method for producing a laminated glass for vehicles according to claim 1 or 2, wherein the laminated glass for vehicles is a windshield.

12. A vehicle comprising a laminated glass for vehicles obtained by the method for producing a laminated glass for vehicles according to claim 1 or 2.

Images