Laminated glass for automobile windows, automobile, and method for manufacturing laminated glass for automobile windows

Abstract

The present invention provides a laminated glass for automobile windows in which a first glass sheet and a second glass sheet are bonded with an intermediate film interposed therebetween, the laminated glass having a first main surface of the first glass sheet that is located on the opposite side from the intermediate film, a second main surface of the first glass sheet in contact with the intermediate film, a third main surface of the second glass sheet in contact with the intermediate film, and a fourth main surface of the second glass sheet that is located on the opposite side from the intermediate film. Each of the first glass sheet and the second glass sheet has a chamfered region at an end part. The chamfered region of the first glass sheet and / or the chamfered region of the second glass sheet has a rough surface part in which the arithmetic mean roughness Ra described in JISB0601:2013 is 50-200 μm, inclusive.

Description

Technical Field

[0001] The present invention relates to an automotive window laminated glass, an automobile, and a method for manufacturing an automotive window laminated glass.

Background Art

[0002] Automobiles are required to have the performance of reducing the impact on a person's body when the person collides. For example, in Patent Document 1, when a pedestrian runs into an automobile and an impact from the front to the lower side is applied around the cowl louver and the windshield glass, a configuration is disclosed in which the connected cowl louver and the windshield are separated to reduce the impact on the pedestrian or the like. Such performance of reducing the impact on a person at the time of collision is also required for the automotive window glass itself.

[0003] As automotive window glass, particularly as a windshield (front glass), generally, a laminated glass formed by joining two glass plates via an interlayer film is used. Patent Document 2 describes that by providing a processed area having a higher fracture strength than the chamfered area between the surface of the glass plate and the chamfered area, the strength of the glass plate can be improved without causing a decrease in productivity.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In laminated glass for automobile windows, improving the performance of reducing the impact on people during collisions requires that the glass plates constituting the laminated glass break appropriately during a collision to absorb the impact. However, the window glass configuration described in Patent Document 2 is aimed at improving the strength of the glass plates as a barrier against flying objects from the outside, and does not consider the performance of laminated glass required in the event of a collision with a person. Therefore, a configuration that can reduce the impact on people during a collision is required. On the other hand, laminated glass for automobile windows needs to maintain sufficient robustness or durability as automobile window glass.

[0006] One aspect of the present invention aims to provide laminated glass for automobile windows that reduces the impact on people during collisions and has sufficient robustness as automobile window glass. [Means for solving the problem]

[0007] One aspect of the present invention is a laminated glass for an automobile window, comprising a first glass plate and a second glass plate joined together via an interlayer, wherein the first glass plate has a first main surface located on the side opposite to the interlayer, a second main surface in contact with the interlayer, a third main surface in contact with the interlayer, and a fourth main surface located on the side opposite to the interlayer, and the first glass plate and the second glass plate each have a chamfered region at their ends, and at least one of the chamfered region of the first glass plate and the chamfered region of the second glass plate has a roughened surface portion having an arithmetic mean roughness Ra of 50 μm or more and 200 μm or less as described in JIS B0601:2013. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to provide laminated glass for automobile windows that reduces the impact on people during collisions and has sufficient robustness as automobile window glass. [Brief explanation of the drawing]

[0009] [Figure 1]This is a front view of an automobile equipped with laminated glass according to an embodiment of the present invention. [Figure 2] Figure 1 is a front view of laminated glass (windshield). [Figure 3] Figure 2 is a cross-sectional view of line II, and is a diagram illustrating the first embodiment. [Figure 4] This is a diagram illustrating chamfering and the chamfered area. [Figure 5] This figure shows a modified example of the first embodiment. [Figure 6] This figure shows a modified example of the second embodiment. [Figure 7] This figure shows a modified example of the third embodiment. [Figure 8] This figure shows a modified example of the fourth embodiment. [Figure 9] This is a cross-sectional view taken along line II-II in Figure 8. [Figure 10] This figure shows a modified example of the fourth embodiment. [Modes for carrying out the invention]

[0010] <First Embodiment> (Basic structure of laminated glass) Figure 1 shows an automobile 100 equipped with laminated glass 1 for automobile windows according to this embodiment. In the example shown in Figure 1, the laminated glass 1 for automobile windows is glass installed in the opening (window) at the front of the vehicle body, i.e., the windshield. However, the laminated glass 1 for automobile windows according to this embodiment can also be used as window glass other than the windshield, for example, side windows, rear windows, and roof windows.

[0011] Figure 2 shows a plan view of only the laminated glass 1 for automobile windows in Figure 1, as seen from the outside of the vehicle. As shown in Figure 2, the plan view shape of the laminated glass 1 for automobile windows in this embodiment may be approximately rectangular. In that case, when the laminated glass 1 is installed in an automobile and viewed from the outside, it may have an upper edge 101 located on the upper side, a lower edge 104 located on the lower side, and a left edge 102 located on the left side and a right edge 103 located on the right side (collectively referred to as side edges 102 and 103). In the drawings, when the laminated glass 1 for automobile windows according to this embodiment is installed in an automobile and viewed from the front, the direction from approximately left to right is the x-direction, the direction from approximately bottom to top is the y-direction, and the thickness direction of the laminated glass 1, which is from the inside of the vehicle to the outside of the vehicle, is the z-direction (a direction perpendicular to the x-direction and y-direction).

[0012] Figure 3 shows a cross-sectional view (section II) of the laminated glass for automobile windows 1, cut near the periphery in a direction perpendicular to the periphery. As shown in Figure 3, the laminated glass for automobile windows 1 is made by joining a first glass plate 10 and a second glass plate 20 via an interlayer 30. In the example in Figure 3, the first glass plate 10 is located on the outside of the vehicle, and the second glass plate 20 is located on the inside of the vehicle. The first glass plate 10 has a first main surface 11 located on the opposite side of the interlayer 30 and a second main surface 12 in contact with the interlayer 30. The second glass plate 20 has a third main surface 21 in contact with the interlayer 30 and a fourth main surface 22 located on the opposite side of the interlayer 30.

[0013] The materials constituting the first glass plate 10 and the second glass plate 20 (hereinafter also simply referred to as the glass plate) are preferably inorganic glass. Examples of inorganic glass include soda-lime silicate glass, aluminosilicate glass, borate glass, lithium aluminosilicate glass, borosilicate glass, and the like. The forming method of the glass plate made of inorganic glass is not particularly limited, but it is preferable that the glass plate is formed by, for example, the float method or the like. Also, the glass plate may be unstrengthened glass (raw glass). Unstrengthened glass is glass formed by shaping molten glass into a plate shape and then slowly cooling it, and it has not been subjected to strengthening treatments such as air-cooling strengthening treatment or chemical strengthening treatment. By using unstrengthened glass, even when the glass is impacted and cracked, the entire surface does not break into fine pieces, and the visibility of the passengers can be ensured even in case of an accident.

[0014] The thickness of the first glass plate 10 and the thickness of the second glass plate 20 may be the same, or may be different as shown in the following embodiment (FIG. 7). The specific thicknesses of the first glass plate 10 and the second glass plate may each be 0.5 mm or more and 3.5 mm or less. Also, the thickness of the laminated glass 1 for vehicle windows as a whole (including the thickness of the intermediate film 30) may be 2.3 mm or more and 8.0 mm or less. Note that the configurations of the first glass plate 10 and the second glass plate 20 (materials constituting the glass plate, manufacturing method of the glass plate, etc.) may also be the same.

[0015] The material of the interlayer 30 placed between the first glass plate 10 and the second glass plate 20 is not particularly limited, but it is preferably a thermoplastic resin. Examples of materials for the interlayer 30 include thermoplastic resins that have been conventionally used in the same applications, 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, resin compositions containing modified block copolymer hydrides described in Japanese Patent No. 6065221 can also be suitably used. Among these, plasticized polyvinyl acetal resins are suitably used because they have an excellent balance of various properties such as transparency, weather resistance, strength, adhesiveness, puncture 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 types. In the context of the above-mentioned plasticized polyvinyl acetal resins, "plasticization" refers to the process of plasticization through the addition of a plasticizer. The same applies to other plasticized resins.

[0016] The interlayer 30 may be a resin that does not contain plasticizers, such as an ethylene-vinyl acetate copolymer resin. Examples of the polyvinyl acetal resins 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-butyraldehyde. In particular, PVB is a suitable material because it has an excellent balance of various properties such as transparency, weather resistance, strength, adhesiveness, puncture resistance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. The above resins may be used individually or in combination of two or more types.

[0017] Furthermore, a shielding layer (hereinafter referred to as reference numeral 50) for protecting a sealant or the like that adheres and holds the laminated glass 1 for automotive windows to the vehicle body may be provided at the periphery of the laminated glass 1 for automotive windows. The shielding layer can be formed, for example, by applying a ceramic color paste of a low brightness color such as black, gray, or brownish color containing a fusible glass frit containing a black pigment, and firing it. The shielding layer may be formed on one or more of the second main surface 12, the third main surface 21, and the fourth main surface 22 (FIG. 3) of the laminated glass 1 for automotive windows, preferably at the periphery of at least one of the second main surface 12 and the fourth main surface 22. The shielding layer may be provided over a range from 10 mm or more to 300 mm or less from the peripheral edge of the glass plate.

[0018] The laminated glass 1 for automotive windows can be manufactured by overlapping a first glass plate 10 and a second glass plate 20 that are bent and formed by gravity forming, press forming, or the like, through an intermediate film 30, and then performing pressure bonding. An autoclave or the like can be used for the pressure bonding.

[0019] In the above bending and forming, the first glass plate 10 and the second glass plate 20 can be processed to have a desired curvature in one direction or two directions, for example, in the vertical and horizontal directions when attached to a window frame in the front of an automobile. The radius of curvature of the first glass plate 10 and the radius of curvature of the second glass plate 20 may be the same or different.

[0020] In the manufacture of the laminated glass 1 for automotive windows, a flat glass plate is produced before the step before the above bending and forming. The production of the flat glass plate may include, for example, cutting a blank from a strip-shaped glass plate obtained by the float method, cutting it into a desired outer shape, for example, the outer shape of a windshield, and chamfering. In the example shown in FIG. 3, the end faces of both the first glass plate 10 and the second glass plate 20 are chamfered, and chamfered regions 15 (first chamfered region 151 and second chamfered region 152) of the first glass plate 10 and chamfered regions 25 (third chamfered region 251 and fourth chamfered region 252) of the second glass plate 20 are formed.

[0021] (Chamfering process and chamfered area) Here, chamfering will be explained with reference to Figure 4. Figure 4(a) shows the first glass plate 10 from Figure 3 as an example. In Figure 4(a), the outer contour of the part removed by chamfering is shown by a dotted line. Before chamfering, the original side surface 13' of the glass plate (the side surface immediately after being cut into the desired shape during the glass plate manufacturing process) usually extends in a direction perpendicular to the first main surface 11 and the second main surface 12, and a sharp corner of approximately 90° is formed at the position where the main surfaces 11, 12 and the original side surface 13' meet. Chamfering is a process that removes such sharp corners and forms a surface. This process can prevent injuries that may occur when an operator comes into contact with a sharp corner, and can also prevent damage to equipment or components that may occur when equipment or components other than the glass plate come into contact with the corner during subsequent processing steps.

[0022] Figure 4(a) shows an example of chamfering, where the chamfered areas 15 (first chamfered area 151 and second chamfered area 152) formed by this chamfering process are planar, or in other words, they are straight when viewed in a cross-section cut in a direction perpendicular to the periphery of the glass plate. The first chamfered area 151 connects the first main surface 11 and the side surface 13, and the second chamfered area 152 connects the second main surface 12 and the side surface 13.

[0023] The chamfering process is not limited to the thread chamfering process described above, and may also be R-chamfering, where the chamfered area has a curved cross-section, that is, the surface of the chamfered area is curved. Therefore, in Figure 4(a), the first chamfered area 151 connecting the first main surface 11 and the side surface 13 may be processed to have a curved surface rather than a flat surface, and the second chamfered area 152 connecting the second main surface 12 and the side surface 13 may be processed to have a curved surface rather than a flat surface. Furthermore, as in the example in Figure 4(b), a first chamfered area 151 adjacent to the first main surface and a second chamfered area 152 adjacent to the second main surface may be formed, but the original side surface 13' may not be left behind, and the first chamfered area 151 and the second chamfered area 152 may be processed to form a single continuous curved surface.

[0024] Chamfering can be performed using cutting tools, polishing tools, lasers, blasting, etching, or other known chamfering methods.

[0025] Referring again to Figure 3, the laminated glass 1 for automobile windows according to the first embodiment will be described. In the laminated glass 1, the edge of the first glass plate 10 is chamfered to form a first glass plate chamfered region 15. The edge of the second glass plate 20 is also chamfered to form a second glass plate chamfered region 25. In the example shown in Figure 3, the first glass plate chamfered region 15 includes a first chamfered region 151 adjacent to the first main surface 11 and a second chamfered region 152 adjacent to the second main surface 12, and the second glass plate chamfered region 25 includes a third chamfered region 251 adjacent to the third main surface 21 and a fourth chamfered region 252 adjacent to the fourth main surface 22. In the example shown in Figure 3, the first chamfered area 151, the second chamfered area 152, the third chamfered area 251, and the fourth chamfered area 252 are all formed by thread chamfering, but all or part of the above chamfered areas may be formed by R chamfering. Furthermore, in the laminated glass 1 according to this embodiment, the first chamfered area 151, the second chamfered area 152, the third chamfered area 251, and the fourth chamfered area 252 do not necessarily have to be formed in their entirety, but from the viewpoint of preventing injury to workers and preventing damage to equipment and other components as described above, it is preferable that all four chamfered areas are formed.

[0026] (Rough surface part) In this embodiment, at least a portion of the chamfered area described above is roughened. More specifically, at least one of the first glass plate chamfered area 15 and the second glass plate chamfered area 25 (hereinafter sometimes simply referred to as the chamfered area) is roughened and has a roughened portion rs. More specifically, at least one of the first chamfered area 151, the second chamfered area 152, the third chamfered area 251, and the fourth chamfered area 252 is at least partially roughened and has a roughened portion rs. In this specification, the roughened portion rs refers to the portion with an arithmetic mean roughness Ra of 50 μm or more and 200 μm or less as described in JIS B0601:2013. In this embodiment, because the chamfered area of ​​the glass plate has a roughened portion rs, when the laminated glass for automobile windows 1 collides with a person, the glass plate becomes moderately prone to breaking, and the impact on the person can be mitigated.

[0027] When a person collides with laminated glass for an automobile window, the point where the laminated glass 1 receives direct impact (impact point) is usually the main surface (first main surface 11 or fourth main surface 22). However, the energy of the impact received by the laminated glass 1 spreads from the impact point outwards and propagates to the edges (periphery) of the glass plate. In this embodiment, where a rough surface is formed in the chamfered region, stress tends to concentrate more easily on the fine irregularities of the rough surface, making the glass plate more prone to cracking at the rough surface. In other words, this embodiment allows the strength of the glass plate to be reduced at the edges (periphery). Therefore, even if cracking does not start from the impact point within the main surface, the edge of the glass plate can become the starting point for cracking, allowing the glass plate to crack appropriately, and the impact of the collision can be absorbed by that crack. In recent years, regarding the performance of laminated glass for automobile windows, not only the protection of occupants but also the protection of pedestrians (pedestrians, cyclists, etc.) in the event of a collision has become important, and it is required to meet specific standards such as the Head Injury Criterion (HIC). In response to this, the above-described form can mitigate or absorb the impact on people when occupants are hit from the inside of the laminated glass, and / or when pedestrians are hit from the outside of the laminated glass, thereby ensuring the safety of people's bodies.

[0028] Furthermore, in order to reduce the impact on people during a collision, it might be conceivable to change the composition of the glass or other factors to make the glass material itself more brittle. However, in that case, the original function of the car window glass may be impaired. For example, its durability or robustness may decrease, impairing its function as a barrier against flying objects such as flying stones. With this embodiment, the original function of the car window glass can be maintained without changing the glass composition or other factors, while reducing the impact on people during a collision.

[0029] Furthermore, the roughness Ra of the roughened portion rs provided in the chamfered area may preferably be 50 μm or more, more preferably 100 μm or more. This improves the effect of absorbing the impact on a person during a collision. Also, from the viewpoint of maintaining the robustness of the glass plate, as well as from the viewpoint of preventing injuries to workers and preventing damage to equipment or other components during manufacturing, the upper limit of the roughness Ra may preferably be 200 μm or less, more preferably 150 μm or less.

[0030] The rough surface portion rs may be formed in a part of the chamfered area, or it may be formed in the entire chamfered area. In the former case, for example, one to three of the first chamfered area 151, the second chamfered area, the third chamfered area 251, and the fourth chamfered area 252 may have the rough surface portion rs, while the remaining chamfered area may not have the rough surface portion rs. Also, in a single chamfered area, the rough surface portion rs and the non-rough surface portion (i.e., the portion with an arithmetic mean roughness Ra of less than 50 μm as described in JIS B0601:2013) may be provided adjacent to each other along the circumferential direction (x direction in the case of Figure 3) of the chamfered area, or adjacent to each other along the thickness direction (z direction). However, it is preferable that the total area of ​​the rough surface portion rs is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more of the total area of ​​the chamfered areas in the laminated glass for automobile windows 1. Furthermore, it is preferable that the entire beveled area of ​​the laminated glass for automobile windows 1 is a roughened surface rs, that is, the entire beveled area is roughened. This improves the aforementioned effect of reducing the impact on people during a collision.

[0031] When a person collides with laminated glass for a car window from one side, the impact of the collision propagates from that side to the opposite side in the thickness direction. In this case, for example, if a person collides from the outside of the car, compressive stress is generated on the outer main surface of the outer glass plate, and tensile stress is generated on the inner main surface. Therefore, cracking is more likely to begin on the inner surface where tensile stress is generated. Thus, from the viewpoint of reducing the impact on a person outside the car during a collision, it is preferable to roughen the chamfered area of ​​the outer glass plate that is in contact with the inner main surface, and / or roughen the chamfered area of ​​the inner glass plate that is in contact with the inner main surface. Therefore, as shown in the example in Figure 3, when the first glass plate 10 is the outer glass plate and the second glass plate 20 is the inner glass plate, it is preferable that the second chamfered region 152 in contact with the second main surface 12 of the first glass plate 10 has a rough surface portion rs, and / or that the fourth chamfered region 252 in contact with the fourth main surface 22 of the second glass plate 20 has a rough surface portion rs, and it is particularly preferable that the second chamfered region 152, which receives a greater impact, has a rough surface portion rs.

[0032] Furthermore, for similar reasons, from the viewpoint of reducing the impact on people inside the vehicle during a collision, it is preferable to roughen the chamfered area of ​​the inner glass plate that is in contact with the outer main surface, and it is also preferable to roughen the chamfered area of ​​the outer glass plate that is in contact with the outer main surface. Therefore, as shown in the example in Figure 3, when the first glass plate 10 is the outer glass plate and the second glass plate 20 is the inner glass plate, it is preferable that the third chamfered area 251 in contact with the third main surface 21 of the second glass plate 20 has a roughened portion rs, and / or that the first chamfered area 151 in contact with the first main surface 11 of the first glass plate 10 has a roughened portion rs, and it is particularly preferable that the third chamfered area 251, which receives a greater impact, has a roughened portion rs.

[0033] Furthermore, the surface roughness Ra of different chamfered regions may be the same or different. For example, the surface roughness Ra of the second chamfered region 152 can be made greater than that of the first chamfered region 151 to make the first glass plate 10 more susceptible to cracks originating from its edges in response to impacts from the first glass plate 10 side. Also, the surface roughness Ra of the third chamfered region 251 can be made greater than that of the fourth chamfered region 252 to make the second glass plate 20 more susceptible to cracks originating from its edges in response to impacts from the second glass plate 20 side.

[0034] Furthermore, the surface roughness Ra of the roughened portion rs in a single chamfered area may be uniform or may vary from place to place. If the surface roughness Ra of the roughened portion rs in a single chamfered area varies, it may vary in the circumferential direction (x-direction in the case of Figure 3) or in the thickness direction (z-direction).

[0035] The formation of the rough surface portion rs in the chamfered area can be performed in a normal chamfering process by adjusting the processing conditions of the chamfering means described above. Therefore, in this embodiment, a configuration that can absorb the impact on a person during a collision can be obtained without requiring significant effort or cost. If the processing means used is an abrasive tool, it can be adjusted by increasing the grit size of the grinding wheel of the abrasive tool. For example, to obtain the rough surface portion rs, an abrasive tool equipped with a grinding wheel of #160 to #200 can be used.

[0036] In the example shown in Figure 3, the edges (non-main surfaces) of the first glass plate 10 and the second glass plate 20, specifically the non-chamfered areas (side surface 13 of the first glass plate 10 and side surface 23 of the second glass plate 20), may or may not have a roughened surface portion rs. That is, side surfaces 13 and 23 may have an arithmetic mean roughness Ra of 50 μm or more and 200 μm or less as described in JIS B0601:2013, or they may be non-roughened areas with an arithmetic mean roughness Ra of less than 50 μm as described in JIS B0601:2013. When using a grinding tool as a processing means for chamfering, such non-roughened areas can be formed, for example, by using a grinding wheel of #200 or more and #230 or less.

[0037] The roughened portion rs may be provided along the entire periphery of the laminated glass for automobile windows 1, or it may be provided on only a part of the periphery. For example, the roughened portion rs may be provided on at least one of the upper edge 101, side edges 102, 103, and lower edge 104 (Figure 2) of the laminated glass for automobile windows 1, and depending on the application of the laminated glass 1, it can be formed on the periphery close to the area where it is desired to cause appropriate breakage in the event of a collision with a person. Recent studies have shown that when a person outside the vehicle, such as a pedestrian, collides with the windshield, the person who collides is more likely to suffer serious injuries if the collision occurs at the lower part of the windshield ("Biomechanics of Pedestrians in Vehicle Collisions," Journal of the Japan Society for Biomechanics, Vol. 36, No. 4 (2012)). Therefore, by making the lower part of the windshield more easily breakable in the event of a collision, it is possible to avoid serious injury to the person who collides. For this reason, it is preferable to provide the roughened portion rs in the chamfered area at the end of the lower edge 104 of the laminated glass for automobile windows 1. In particular, it is preferable to form a first chamfered area 151, a second chamfered area 152, a third chamfered area 251, and a fourth chamfered area 252 over the entire periphery on the lower side 104, and each of them has a rough surface portion rs, and it is more preferable that each of them has a rough surface portion rs.

[0038] Figure 5 shows a modified example of laminated glass for automobile windows from the first embodiment. The laminated glass 1 shown in Figure 5 has the same configuration as the laminated glass 1 shown in Figure 3, but differs from the laminated glass 1 in that the ends of the first glass plate 10 and the second glass plate 20 are curved. Specifically, in the laminated glass 1 shown in Figure 5, both the chamfered area 15 of the first glass plate and the chamfered area 25 of the second glass plate are curved in cross-section, i.e., chamfered areas having a curved surface. Similar to the example in Figure 3, the chamfered area 15 of the first glass plate has a first chamfered area 151 and a second chamfered area 152, and these first chamfered area 151 and the second chamfered area 152 are a continuous curved surface. Similarly, the chamfered area 25 of the second glass plate has a third chamfered area 251 and a fourth chamfered area 252, and these third chamfered area 251 and the fourth chamfered area 252 are also a continuous curved surface. In other words, in the example shown in Figure 5, the entire edge surfaces of the first glass plate 10 and the second glass plate 20 are each rounded off.

[0039] In the example shown in Figure 5, the first chamfered area 151, the second chamfered area 152, the third chamfered area 251, and the fourth chamfered area 252 also have roughened surfaces rs. The details of the roughened surfaces rs are the same as those of the laminated glass 1 for automobile windows shown in Figure 3.

[0040] <Second Embodiment> Figure 6 shows a laminated glass 1A for automobile windows according to the second embodiment. In the laminated glass 1A shown in Figure 6, the position of the edge 17 of the first glass plate 10 and the position of the edge 27 of the second glass plate 20 are not aligned, but are offset in the y direction in Figure 6. More specifically, the position of the edge 17 of the first glass plate 10 is positioned inward (away from the outer edge of the entire laminated glass) at least in part of its periphery than the position of the edge 27 of the second glass plate 20. In other words, the second glass plate 20 protrudes outward more than the first glass plate 10. Because the second glass plate 20 protrudes outward in this way, when a person collides with the laminated glass 1A, the second glass plate 20 in particular can break appropriately, mitigating the impact on the person. Therefore, as shown in Figure 6, when the first glass plate 10 is positioned on the outside of the vehicle and the second glass plate 20 is positioned on the inside of the vehicle, when a person on the inside of the vehicle collides with it, the glass plate on the inside of the vehicle is more likely to break starting from its edge, preventing damage to the occupants, etc. On the other hand, unlike the arrangement shown in Figure 6, if the first glass plate 10 is positioned on the inside of the vehicle and the second glass plate 20 is positioned on the outside, the glass plate on the outside of the vehicle is more likely to break properly starting from its edge when a person on the outside of the vehicle collides with it, thus preventing damage to pedestrians and others. Furthermore, in either case, there is no need to change the composition of the first glass plate 10 and the second glass plate 20, or the configuration of the central region in a plan view, so the durability or robustness as automotive window glass can be maintained.

[0041] In this embodiment, where the edges of the two glass plates are misaligned, the misalignment Δd, that is, the distance between the edge 17 of the first glass plate 10 and the edge 27 of the second glass plate 20, may be between 2 mm and 3 mm in the direction perpendicular to the periphery (y-direction in Figure 6). By setting Δd within this range, the protruding edge of the glass plate becomes more likely to become the starting point for cracking, while maintaining the structure of laminated glass.

[0042] The area where the edge 17 of the first glass plate 10 and the edge 27 of the second glass plate 20 are misaligned may be at least a part of the top edge 101, side edges 102, 103, and bottom edge 104 (Figure 2) of the laminated glass. As described above, when the laminated glass for automobile windows is a windshield, injuries to pedestrians and others who are hit tend to be more severe at the bottom of the glass. Therefore, by misaligning the edge 17 of the first glass plate 10 and the edge 27 of the second glass plate 20 across the bottom edge 104 of the laminated glass 1A, injuries to people can be effectively reduced.

[0043] Furthermore, the edges of the two glass plates may be offset around the entire circumference of the laminated glass 1A. In that case, a configuration can be obtained in which, in a plan view, the first glass plate 10 is within the range of the second glass plate 20, and the area of ​​the first glass plate 10 is smaller than the area of ​​the second glass plate 20.

[0044] The configuration of laminated glass 1A, in which the edges of the first glass plate 10 and the second glass plate 20 are offset in at least a portion of the periphery of the laminated glass, can be combined with the configuration of laminated glass 1 (a configuration in which the chamfered area at the end has a rough surface portion rs) as described with reference to Figures 3 and 5. This allows for appropriate adjustment of the ease with which the glass plate breaks in the event of a person's collision.

[0045] <Third Embodiment> Figure 7 shows a laminated glass 1B for automobile windows according to the third embodiment. In the laminated glass 1B shown in Figure 7, the thickness t1 of the first glass plate 10 and the thickness t2 of the second glass plate 20 are different. In this example, as shown in Figure 7, it is preferable that when the laminated glass 1B is installed in an automobile, the first glass plate 10 is positioned on the outside of the vehicle and the second glass plate 20 is positioned on the inside. That is, it is preferable that the thickness of the glass plate on the outside of the vehicle is thinner than the thickness of the glass plate on the inside of the vehicle. This allows the glass on the outside of the vehicle to break appropriately and absorb the impact if a person outside the vehicle collides with the vehicle.

[0046] The difference Δt(|t1-t2|) between the thickness t1 of the first glass plate 10 and the thickness t2 of the second glass plate 20 may be between 0.2 mm and 2.0 mm. By setting Δt within the above range, it is possible to appropriately reduce the impact on people while maintaining the robustness of the window glass, and to obtain a configuration that does not crack or break, especially when struck by flying objects such as flying stones.

[0047] This configuration of laminated glass 1B, in which the first glass plate 10 and the second glass plate 20 have different thicknesses, can be combined with the configuration of laminated glass 1 (a configuration in which the chamfered area at the edge has a rough surface portion rs) as described with reference to Figures 3 and 5. This allows for appropriate adjustment of the ease with which the glass plate breaks in the event of a person's collision.

[0048] <Fourth Embodiment> Figure 8 shows a laminated glass 1C for automobile windows according to the fourth embodiment. Figure 8 is a plan view of the laminated glass 1C as seen from the outside of the vehicle. Figure 9 shows a cross-sectional view taken along line II-II in Figure 8. As shown in Figures 8 and 9, in the laminated glass 1C, a recess 18 is formed on the periphery of the first glass plate 10. That is, a portion of the periphery of the first glass plate 10 is formed to be located inward from the periphery of the second glass plate 20.

[0049] Stress tends to concentrate in such recesses 18. Therefore, when a person collides with laminated glass, a crack is likely to start at the edge of the first glass plate 10. Thus, as in the example in Figure 8, when the first glass plate 10 is located on the outside of the vehicle and the second glass plate 20 is located on the inside, it is preferable to have the recess 18 formed on the first glass plate 10, which receives a greater impact when a person collides with it from the outside of the vehicle. This reduces the impact on the person, especially when a person collides with it from the outside of the vehicle.

[0050] The recess 18 can be formed on any side of the laminated glass 1C for automobile windows. For example, as shown in Figure 8, one recess 18 may be formed on each of the bottom edge 104 and side edges 102 and 103 of the laminated glass. However, as mentioned above, if the laminated glass for automobile windows is a windshield, injuries are more likely to be severe if a pedestrian or the like collides with the lower part of the glass, so it is preferable to reduce the strength of the bottom edge of the laminated glass. Therefore, it is preferable that the recess 18 is formed at least on the periphery of the bottom edge 104. The number of recesses 18 may be one or more, but considering the durability of the laminated glass 1C, it is preferable to have three or fewer on each side.

[0051] Figures 8 and 9 also show the aforementioned shielding layer 50, which is formed by applying and firing ceramic color paste. In this example, it is provided on the fourth main surface 22 of the laminated glass 1C for automobile windows. It is preferable that the recess 18 is formed within the area where the shielding layer 50 is provided, in a plan view.

[0052] The depth a of the recess 18, that is, the length from the edge to the bottom point of the recess 18 when viewed in a cross section perpendicular to the periphery (Figure 8), may be between 50 mm and 200 mm. By having the depth a of the recess 18 within the above range, the strength of the glass plate at the end can be appropriately reduced while ensuring the function of the laminated glass 1C as window glass.

[0053] In the example shown in Figure 8, the contour of the recess 18 is part of a circle, but the plan view shape of the recess 18 is not limited to that shown. For example, the plan view shape of the recess 18 may be a quadrilateral such as a trapezoid, or other polygons. Furthermore, if the contour of the recess 18 is part of a circle as shown in Figure 8, its radius of curvature may be between 130 mm and 1000 mm.

[0054] In the examples shown in Figures 8 and 9, a recess is formed on the periphery of the first glass plate 10 on the outside of the vehicle, but a similar recess may be formed on the periphery of the second glass plate 20 on the inside of the vehicle. In that case, the glass plate on the inside of the vehicle can break appropriately, especially if a person collides with the vehicle from the inside, which is preferable from the viewpoint of reducing the impact on the occupants of the vehicle.

[0055] Figure 10 shows a modified example of the fourth embodiment. In this example, a recess 18 is formed on the periphery of the first glass plate 10, and a recess 28 is also formed on the periphery of the second glass plate 20. In the example in Figure 10, the contours of both recesses 18 and 28 are aligned in plan view, but the contours of the two recesses 18 and 28 may be different. In this example as well, the strength at the edges of both the first glass plate 10 and the second glass plate 20 can be appropriately reduced, so that both the first glass plate 10 and the second glass plate 20 become more prone to breaking during a collision, thereby absorbing and mitigating the impact.

[0056] The configuration of the laminated glass 1C for automobile windows according to the fourth embodiment described above can also be combined with the configuration of the laminated glass 1 described with reference to Figures 3 and 5 (a configuration in which the chamfered area at the end has a rough surface portion rs). This allows for appropriate adjustment of the ease with which the glass plate breaks in the event of a collision with a person.

[0057] The individual components included in the first to fourth embodiments described above can be combined in any way. Furthermore, in any of the above embodiments, the radii of curvature of the first glass plate 10 and the second glass plate 20 can preferably be 10,000 mm or more, more preferably 15,000 mm or more. This allows for an appropriate reduction in the overall strength of the glass plate, thereby increasing the freedom of other manufacturing conditions for laminated glass for automobile windows. For example, even when using a thick glass plate or a high-strength glass material, the susceptibility to breakage during a collision can be adjusted by using a glass plate with the above-mentioned radius of curvature. When laminated glass for automobile windows is used as a windshield, the radii of curvature of the first glass plate 10 and the second glass plate 20 are preferably 10,000 mm or less, taking into consideration robustness and design.

[0058] <Manufacturing method for laminated glass for automobile windows> One embodiment of the present invention may be a method for manufacturing laminated glass for automobile windows as described above. This manufacturing method provides for laminated glass for automobile windows having a first main surface of the first glass plate located on the side opposite to the interlayer, a second main surface of the first glass plate in contact with the interlayer, a third main surface of the second glass plate in contact with the interlayer, and a fourth main surface of the second glass plate located on the side opposite to the interlayer, wherein the first glass plate and the second glass plate each have a chamfered region at their edges, wherein at least one of the chamfered region of the first glass plate and the chamfered region of the second glass plate is formed to have a rough surface portion with an arithmetic mean roughness Ra of 50 μm or more and 200 μm or less as described in JIS B0601:2013. By this method, laminated glass for automobile windows with appropriately reduced edge strength can be obtained. Therefore, when an automobile collides with a person, the glass plate breaks appropriately and absorbs the impact, thereby reducing damage to the person.

[0059] This application claims priority under Japanese Patent Application No. 2021-071148, filed on April 20, 2021, which is incorporated herein by reference in its entirety. [Explanation of symbols]

[0060] 1. Laminated glass for automobile windows 10. First glass plate 11 1st main surface 12 Second main surface 13 Side view of the first glass plate 15. First glass plate beveling area 17 Edge of the first glass plate 18 Recess of the first glass plate 20. Second glass plate 21 Third main surface 22 4th main surface 23 Side view of the second glass plate 25. Second glass plate beveling area 27 Edge of the second glass plate 28 Recess of the second glass plate 30 Interlayer 151 First chamfered area 152 Second chamfer area 251 Third chamfered area 252 Fourth chamfered area 100 automobiles rs Rough surface area

Claims

1. A laminated glass for automobile windows, comprising a first glass plate and a second glass plate joined together with an interlayer film, The first main surface of the first glass plate, which is located on the side opposite to the interlayer, The second main surface of the first glass plate that is in contact with the interlayer, The third main surface of the second glass plate that is in contact with the interlayer, The second glass plate has a fourth main surface located on the opposite side from the interlayer, The first glass plate and the second glass plate each have a chamfered area at their edges. Laminated glass for automobile windows, wherein at least one of the beveled area of ​​the first glass plate and the beveled area of ​​the second glass plate has a roughened surface portion having an arithmetic mean roughness Ra of 50 μm or more and 200 μm or less as described in JIS B0601:2013.

2. The laminated glass for automobile windows according to claim 1, wherein the beveled area of ​​the first glass plate includes a first beveled area adjacent to the first main surface, and the first beveled area has the roughened portion.

3. The laminated glass for automobile windows according to claim 1, wherein the beveled area of ​​the first glass plate includes a second beveled area adjacent to the second main surface, and the second beveled area has the roughened portion.

4. The laminated glass for automobile windows according to claim 1, wherein the beveled area of ​​the second glass plate includes a third beveled area adjacent to the third main surface, and the third beveled area has the roughened portion.

5. The laminated glass for automobile windows according to claim 1, wherein the chamfered area of ​​the second glass plate includes a fourth chamfered area adjacent to the fourth main surface, and the fourth chamfered area has the roughened portion.

6. The laminated glass for automobile windows according to claim 1, wherein the roughened portion is provided on the side that becomes the bottom edge and / or side edge when the laminated glass for automobile windows is installed in an automobile.

7. The laminated glass for an automobile window according to claim 1, wherein, in a plan view, at least a portion of the periphery of the second glass plate is located inward from the periphery of the first glass plate.

8. The laminated glass for automobile windows according to claim 1, wherein the first glass plate has a recess at its periphery in a plan view, at least on the lower edge and / or side edge when the laminated glass for automobile windows is installed in an automobile.

9. The laminated glass for automobile windows according to claim 1, wherein the second glass plate has a recess at its periphery in a plan view at the lower edge and / or side edge when the laminated glass for automobile windows is installed in an automobile.

10. The laminated glass for automobile windows according to claim 1, wherein when the laminated glass for automobile windows is installed in an automobile, the first glass plate is located on the outside of the vehicle and the second glass plate is located on the inside of the vehicle.

11. The laminated glass for automobile windows according to claim 10, wherein the thickness of the first glass plate is thinner than the thickness of the second glass plate.

12. An automobile equipped with laminated glass for automobile windows according to any one of claims 1 to 11.

13. A method for manufacturing laminated glass for automobile windows, comprising a first glass plate and a second glass plate joined together via an interlayer, Laminated glass for car windows, The first main surface of the first glass plate, which is located on the side opposite to the interlayer, The second main surface of the first glass plate that is in contact with the interlayer, The third main surface of the second glass plate that is in contact with the interlayer, The second glass plate has a fourth main surface located on the opposite side from the interlayer, A method for manufacturing laminated glass for automobile windows, comprising forming chamfered regions on the edges of the first glass plate and the second glass plate, wherein at least one of the chamfered regions of the first glass plate and the second glass plate has a rough surface portion with an arithmetic mean roughness Ra of 50 μm or more and 200 μm or less as described in JIS B0601:2013.

Images