Automobile window laminated glass and automobile

Abstract

A laminated glass for automotive windows which comprises a first glass plate, an interlayer film, and a second glass plate arranged in this order from a vehicle exterior side toward a vehicle interior side, wherein the first glass plate and / or the second glass plate has a plurality of different-quality regions formed by a laser and distributed in the vicinity of the vehicle-interior-side surface so as to be separated from each other in plane directions, the different-quality regions having a ratio of the thickness-direction length to the equivalent circular diameter in a plan view of 2-1,000.

Description

Technical Field

[0001] The present invention relates to laminated glass for automotive windows and automobiles.

Background Art

[0002] When a vehicle collides with a person such as a pedestrian, there is a need for a technique to reduce the impact on the person. For example, Patent Document 1 describes a technique in which when an impact is applied around a cowl louver and a windshield, the rear end portion of the cowl louver connected by a molding and the front end portion of the windshield are separated, reducing the impact on the person.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Laminated glass for automotive windows such as a windshield is required to break appropriately in order to reduce the impact on a person when a vehicle collides with a person such as a pedestrian. For example, it is required that the Head Injury Criterion (HIC) of the laminated glass for automotive windows be below a desired value. On the other hand, it is also required that the occupants of the vehicle can visually recognize the outside of the vehicle through the laminated glass for automotive windows.

[0005] One aspect of the present invention is to reduce the impact on a person when a vehicle collides with a person and to prevent the occupants of the vehicle from being hindered from visually recognizing the outside of the vehicle.

Means for Solving the Problems

[0006] One aspect of the present invention is a laminated glass for an automobile window, comprising a first glass plate, an intermediate film, and a second glass plate in this order from the outside of the vehicle toward the inside of the vehicle, wherein a plurality of heterogeneous regions formed by a laser are provided at intervals in the plane direction near the surface on the inside of the vehicle of the first glass plate and / or the second glass plate, and the value of the ratio of the length in the thickness direction to the equivalent diameter of a circle in a plan view of the heterogeneous region is 2 or more and 1000 or less.

[0007] Another aspect of the present invention is a laminated glass for an automobile window, comprising a first glass plate, an intermediate film, and a second glass plate in this order from the outside of the vehicle toward the inside of the vehicle, wherein a plurality of heterogeneous regions formed by a laser are provided at intervals in the plane direction near the surface on the inside of the vehicle of the first glass plate and / or the second glass plate, and the value of the ratio of the length in the longitudinal direction to the diameter of a cross section orthogonal to the longitudinal direction of the heterogeneous region is 2 or more and 1000 or less.

Advantages of the Invention

[0008] According to one aspect of the present invention, it is possible to provide a technique that reduces the impact on a person during a collision between an automobile and a person and does not prevent the occupants of the automobile from visually recognizing the outside of the automobile.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 5C

Figure 6

Figure 7

Figure 8

Figure 9

DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same reference numerals, and the description thereof may be omitted.

[0011] FIG. 1 shows an example in which a laminated glass 1 for an automobile window manufactured according to an embodiment of the present invention is used as a window glass of an automobile 100. In the example of FIG. 1, the laminated glass for an automobile window (hereinafter, also simply referred to as laminated glass) 1 is a glass mounted on an opening (window) in the front of the vehicle body 2 of the automobile 100, that is, a windshield. However, the laminated glass 1 may be a window glass other than the windshield, for example, a side glass, a rear glass, or a roof glass.

[0012] FIG. 2 shows a partial cross-sectional view of the laminated glass 1 shown in FIG. 1. As shown in FIG. 2, the laminated glass 1 includes a first glass plate 10, an intermediate film 30, and a second glass plate 20 in this order from the outside of the vehicle toward the inside of the vehicle. The first glass plate 10 and the second glass plate 20 are joined by the intermediate film 30. As shown in FIG. 2, the first glass plate 10 has a first surface F1 which is the outside surface of the vehicle and a second surface F2 which is the inside surface of the vehicle, and the second glass plate 20 has a third surface F3 which is the outside surface of the vehicle and a fourth surface F4 which is the inside surface of the vehicle.

[0013] The materials constituting the first glass plate 10 and the second glass plate 20 (hereinafter simply referred to as the glass plates together) in the laminated glass 1 are preferably inorganic glass. Examples of the 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 the glass plate is preferably, for example, glass formed by the float method (float glass).

[0014] Also, the glass plates used for manufacturing the laminated glass 1 may be unstrengthened glass (raw glass). The unstrengthened glass is glass obtained by forming molten glass into a plate shape and slowly cooling it, and has not been subjected to strengthening treatments such as air-cooling strengthening treatment and 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 occupants can be ensured even in the event of an accident.

[0015] The thicknesses of the first glass plate 10 and the second glass plate 20 may be the same or different from each other. The thickness of the first glass plate 10 may be 1.1 mm or more and 3.5 mm or less. Also, the thickness of the second glass plate 20 may be 0.5 mm or more and 2.3 mm or less. Furthermore, the thickness of the entire laminated glass 1 can 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 plates, manufacturing methods of the glass plates, etc.) may also be the same or different from each other.

[0016] The material of the intermediate film 30 is not particularly limited, but is preferably a thermoplastic resin. Examples of the material of the intermediate film 30 include plasticized polyvinyl acetal resins, plasticized polyvinyl chloride resins, saturated polyester resins, plasticized saturated polyester resins, polyurethane resins, plasticized polyurethane resins, ethylene-vinyl acetate copolymer resins, ethylene-ethyl acrylate copolymer resins, cycloolefin polymer resins, ionomer resins, and other thermoplastic resins that have been conventionally used for the same applications. In addition, a resin composition containing a modified block copolymer hydride described in Japanese Patent No. 6065221 can also be preferably used. Among these, a plasticized polyvinyl acetal resin is preferably used because it is excellent in the balance of various properties such as transparency, weather resistance, strength, adhesive strength, 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. In the above plasticized polyvinyl acetal resin, "plasticized" means that it is plasticized by the addition of a plasticizer. The same applies to other plasticized resins.

[0017] The intermediate film 30 may be a resin that does not contain a plasticizer, such as an ethylene-vinyl acetate copolymer resin. 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, polyvinyl butyral resin (PVB) obtained by reacting PVA with n-butyl aldehyde, etc. In particular, PVB is mentioned as a suitable material because it is excellent in the balance of various properties such as transparency, weather resistance, strength, adhesive strength, puncture 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.

[0018] The intermediate film 30 may have either a single-layer structure or a multi-layer structure. The intermediate film 30 may have functions other than adhesion. For example, the intermediate film 30 may have one or more selected from a sound insulation layer, a colored transparent layer, an ultraviolet ray cut layer, an infrared ray cut layer, etc.

[0019] The thickness of the intermediate film 30 may be 0.5 mm or more from the viewpoint of adhesiveness. Further, the thickness of the intermediate film 30 may be 3 mm or less from the viewpoints of light weight and handleability. The thickness of the intermediate film 30 may be constant or may vary according to the position.

[0020] The method for manufacturing the laminated glass 1 includes, for example, the following steps (a) to (c). (a) The first glass plate 10 and the second glass plate 20 are overlapped via the intermediate film 30 to produce a laminate. (b) The laminate is housed inside a housing such as a rubber bag, and while reducing the pressure inside the housing, it is heated to bond the first glass plate 10 and the second glass plate 20 with the intermediate film 30. The air pressure inside the housing is, for example, -100 kPa to -65 kPa based on the atmospheric pressure. The heating temperature of the housing is, for example, 70°C to 110°C. (c) The laminate taken out from the housing is pressure-bonded at a pressure of 0.6 MPa to 1.3 MPa while heating at 100°C to 150°C. For pressure-bonding, for example, an autoclave is used. Note that the method for manufacturing the laminated glass 1 may be a general one and may not include the step (c).

[0021] As shown in FIG. 2, the laminated glass 1 may be curved so as to be convex outward of the vehicle as a whole or partially. In that case, the first glass plate 10 and the second glass plate 20 can be processed and curved to a desired predetermined curvature in one direction or two directions by bending. The laminated glass 1 as shown in FIG. 1 is a complex curve curved in the longitudinal and vertical directions of the vehicle, but may be a single curve curved only in the longitudinal direction or the vertical direction. The radius of curvature of the laminated glass 1 may be 200 mm or more and 300,000 mm or less.

[0022] The first glass plate 10 and the second glass plate 20 are bent and formed before the step (a) above. The bending and forming is performed in a state where the glass is softened by heating. The heating temperature of the glass during bending and forming is, for example, 550°C to 700°C. The first glass plate 10 and the second glass plate 20 may be bent and formed separately, or may be bent and formed simultaneously while being stacked. The bending and forming includes, for example, gravity forming or press forming, and may include both.

[0023] A shielding layer or a light-shielding layer 40 for protecting a sealant or the like for adhering and holding the laminated glass 1 to the vehicle body may be provided at the periphery of the laminated glass 1 (FIGS. 1 and 3). The shielding layer 40 can be formed, for example, by applying and firing a ceramic color paste of a low brightness color such as black, gray, or brown, including a fusible glass frit containing a black pigment. The shielding layer 40 may be formed on one or more of the second surface F2, the third surface F3, and the fourth surface F4 (FIG. 2) of the laminated glass 1, preferably at the periphery of at least one of the second surface F2 and the fourth surface F4 (FIG. 2). The shielding layer 40 may be provided over a position ranging from 10 mm or more to 300 mm or less from the peripheral edge of the glass plate. In this embodiment, the region excluding the region covered by the shielding layer 40 formed on the laminated glass (also referred to as the light-shielding region) becomes the transparent region 5. The transparent region 5 is a region that allows the occupants of the vehicle 100 to visually recognize the outside of the vehicle 100. In other words, the occupants of the vehicle 100 can visually recognize the outside through the transparent region 5.

[0024] As described above, the laminated glass 1 for automotive windows is required to break appropriately to reduce the impact on a person during a collision between the vehicle and a person such as a pedestrian or a cyclist. For example, it is required that the laminated glass 1 has a Head Injury Criterion (HIC) of a desired value or less (for example, 1000 or less, preferably 650 or less).

[0025] Here, the way the laminated glass 1 breaks when it collides with a person will be described. As shown in FIG. 2, when the laminated glass 1 collides with a person 200, the laminated glass 1 is pushed from the outside of the vehicle toward the inside of the vehicle. As a result, tensile stress is generated on the second surface F2, which is the surface on the inside of the vehicle of the first glass plate 10, and the first glass plate 10 breaks starting from a heterogeneous region (defect) near the second surface F2. In addition, tensile stress is also generated on the fourth surface F4, which is the surface on the inside of the vehicle of the second glass plate 20, and the second glass plate 20 breaks starting from a heterogeneous region (defect) near the fourth surface F4. Thus, in both the first glass plate 10 and the second glass plate 20, the break (fracture) starts on the inside of the vehicle, and then the crack propagates from the inside of the vehicle toward the outside of the vehicle.

[0026] In the laminated glass 1 according to this embodiment, the first glass plate 10 and / or the second glass plate 20 have a plurality of heterogeneous regions formed at intervals in the plane direction of the glass plate near the surface on the inside of the vehicle (the surface on the inside of the vehicle), that is, at a position appearing on the surface on the inside of the vehicle or at a depth position inside the first glass plate 10 and / or the second glass plate 20 but close to the surface on the inside of the vehicle. In other words, a plurality of heterogeneous regions are formed at intervals in the plane direction in a region near the second surface F2 inside the first glass plate 10, and / or a plurality of heterogeneous regions (or heterogeneous phases) are formed at intervals in the plane direction in a region near the fourth surface F4 inside the second glass plate 20. The heterogeneous regions in this embodiment are formed by heterogeneous formation by irradiating with a laser beam (described in detail later).

[0027] In this specification, the "heterogeneous region (or heterogeneous phase)" refers to a minute region where the glass is locally heterogeneous within the glass plate, and the heterogeneity means locally changing physical and / or chemical properties. In this specification, the heterogeneous region may be a region where one or more properties such as fictive temperature, density, refractive index, stress, crystal state, composition, ionic valence, and void formation are locally changed by irradiation with laser light (described in detail later). Therefore, the heterogeneous region may be a region including cracks, dents, bubbles, etc. Further, the heterogeneous region may be, for example, a region where the fictive temperature is higher than the value before heterogeneity, specifically, a region where the change is 30 °C or more from the value before heterogeneity. The fictive temperature can be evaluated, for example, by spectroscopic evaluation such as Raman spectroscopy or infrared spectroscopy. Also, the heterogeneous region is a region where the refractive index is lower or higher than the value before heterogeneity, and for example, it may be a region where the change is 0.1% or more with the value before heterogeneity taken as 100%.

[0028] In this embodiment, by forming a heterogeneous region at a position close to the inner surface of the vehicle, which is the side where the laminated glass 1 is most likely to crack first when the laminated glass on both sides of the glass plate is impacted from the outside, the heterogeneous region serves as a starting point for cracking and makes it easier for the cracking of the glass plate to start. As a result, appropriate cracking of the laminated glass 1 is promoted. Further, since a plurality of heterogeneous regions 50 are provided in the vicinity of the inner surface of the vehicle and spaced apart in the surface direction, the surrounding compressive stress generated against the tensile stress in the heterogeneous region 50 appears on the surface (the inner surface of the vehicle), and furthermore, a continuous tensile stress is generated over the entire surface between the compressive stresses appearing on the surface. Therefore, the surface strength is reduced as a whole and it becomes easier to crack. Thus, even when the vehicle collides with a person, the laminated glass 1 can absorb the impact by cracking and reduce the impact on the person. In this embodiment, the difference in the plane stress value between the peripheral part of the heterogeneous region on the inner surface of the vehicle (the second surface F2 and / or the fourth surface F4) of the glass plate can be 0.2 MPa or more and 20 MPa or less.

[0029] In this embodiment, if a heterogeneous region is formed in either the first glass plate 10 or the second glass plate 20, the effect that the laminated glass 1 cracks appropriately as described above can be obtained. However, if the heterogeneous region is formed at least in the second glass plate 20 that is exposed to the outside (inside the vehicle) and not in contact with the intermediate film 30, the laminated glass 1 can be effectively weakened. Further, if heterogeneous regions are formed in both the first glass plate 10 and the second glass plate 20, each of the first glass plate 10 and the second glass plate 20 is likely to crack from the inside of the vehicle, so that the laminated glass 1 as a whole is appropriately likely to crack, and the crack is likely to progress in the thickness direction, which is preferable.

[0030] FIG. 3 shows a plan view of the laminated glass 1 as viewed from the fourth surface F4. The laminated glass 1 has a plurality of heterogeneous regions 50, 50,... in the glass plate. In the example shown in FIG. 3, the heterogeneous regions 50, 50,... include a plurality of first heterogeneous regions 51, 51,... that are spaced apart and scattered throughout the first glass plate 10 in the plane direction, and a plurality of second heterogeneous regions 52, 52,... that are spaced apart and scattered throughout the second glass plate 20 in the plane direction. The first heterogeneous regions 51, 51,... and the second heterogeneous regions 52, 52,... are each arranged in a lattice pattern in plan view, but each arrangement is not limited to the lattice pattern and may be, for example, in a staggered pattern. Further, in the example shown in FIG. 3, each first heterogeneous region 51 and each second heterogeneous region 52 do not overlap in plan view, but a part or all of the first heterogeneous regions 51, 51,... may overlap with the second heterogeneous regions 52, 52,.... Furthermore, in the example shown in FIG. 3, when the first heterogeneous regions 51, 51,... and the second heterogeneous regions 52, 52,... (collectively the heterogeneous regions 50, 50,...) are viewed, they are in a staggered pattern in plan view, but the arrangement is not limited to the staggered pattern and may be, for example, in a lattice pattern.

[0031] The pitch P1 of the first heterogeneous regions 51, 51, … is preferably 1 mm or more and 200 mm or less, more preferably 10 mm or more and 100 mm or less, and still more preferably 20 mm or more and 100 mm or less. The pitch P1 is the distance between the center position of one first heterogeneous region 51 and the center position of another first heterogeneous region 51 arranged closest thereto. The pitch P1 may be uniform over the perspective region 5 or may vary depending on the location, and in the latter case, the average value is used. By setting the pitch P1 to 1 mm or more, it is possible to suppress the phenomenon that the first heterogeneous regions 51, 51 are too close to each other, and the compressive stress generated on the surface is continuously distributed in the plane direction, and instead, the glass plate becomes less likely to break. On the other hand, by setting the pitch P1 to 200 mm or less, the starting points of cracks are appropriately distributed on the inner side surface (second surface F2) of the first heterogeneous regions 51, 51, …, and when an impact is applied to the laminated glass 1 from the outside of the vehicle, the laminated glass 1 becomes more appropriately likely to break.

[0032] The pitch P2 of the second heterogeneous region 52 is also the same as the pitch P1 of the first heterogeneous regions 51, 51, …, and is preferably 1 mm or more and 200 mm or less, more preferably 10 mm or more and 100 mm or less, and still more preferably 20 mm or more and 100 mm or less. The effect of setting the pitch P2 of the second heterogeneous region 52 to 1 mm or more and 200 mm or less is the same as the effect on the inner side surface described for the pitch P1.

[0033] FIG. 4 shows a partially enlarged view of the cross-section taken along line A-A of the laminated glass 1 in FIG. 3. Further, FIG. 5A shows an enlarged view of a portion B in FIG. 4 that includes one heterogeneous region 50 (second heterogeneous region 52). As shown in FIG. 4, the first heterogeneous regions 51, 51,... are formed in the vicinity of the second surface F2 (the surface on the vehicle interior side). Also, the second heterogeneous regions 52, 52,... are formed in the vicinity of the fourth surface F4 (the surface on the vehicle interior side). In other words, the location in the thickness direction of the heterogeneous region 50 (first heterogeneous region 51 or second heterogeneous region 52) formed in the glass plate is closer to the surface on the vehicle interior side than the surface on the vehicle exterior side of the glass plate. Further, when the glass plate is virtually divided at the central position in the thickness direction, it is preferable that the heterogeneous region 50 is included within the range from the central position to the surface on the vehicle interior side of the glass plate. Also, it is preferable that the heterogeneous region 50 is not included within the range from the central position to the surface on the vehicle exterior side of the glass plate.

[0034] The heterogeneous region 50 may or may not extend to the surface on the vehicle interior side (second surface F2 or fourth surface F4) of the glass plate in which the heterogeneous region 50 is formed. That is, the heterogeneous region 50 may or may not appear on the surface on the vehicle interior side. However, from the viewpoint that when the heterogeneous region 50 is in contact with the surface on the vehicle interior side or the heterogeneous region 50 appears on the surface on the vehicle interior side, it is easy to form a crack initiation point on the surface on the vehicle interior side and tensile stress is likely to occur on the surface on the vehicle interior side, it is preferable. On the other hand, from the viewpoint of ensuring the robustness of the laminated glass 1 during normal use without collision, depending on the shape and size of the heterogeneous region 50, it is preferable that the heterogeneous region 50 does not appear on the surface on the vehicle interior side.

[0035] As schematically shown in FIG. 5A, the heterogeneous region 50 has an elongated shape in the thickness direction. Further, the heterogeneous region 50 has a columnar shape or a shape close thereto having an axis in the thickness direction of the glass plate, and may have a larger diameter near the center in the thickness direction and a smaller diameter as it approaches the inner and outer surfaces of the glass plate on the vehicle side. For example, as shown in FIG. 5A, it may have a shape in which the cross section cut in the thickness direction is elliptical. Such a shape of the heterogeneous region 50 is due to a predetermined formation using a laser for the heterogeneous region 50. Therefore, the heterogeneous region 50 is not limited to having the shape shown in FIG. 5A or the like, and may have various configurations depending on laser irradiation conditions and the like.

[0036] The length L (FIG. 5A) of the heterogeneous region 50 in the thickness direction is preferably 0.1 μm or more and 2000 μm or less, more preferably 1 μm or more and 1000 μm or less, still more preferably 10 μm or more and 1000 μm or less, even more preferably 50 μm or more and 1000 μm or less, and particularly preferably 100 μm or more and 1000 μm or less. By setting it to 0.1 μm or more and 2000 μm or less, cracks are likely to progress in the thickness direction during a collision with a person, and the laminated glass 1 can be effectively weakened, while ensuring the robustness and external visibility as an automobile window during normal use when there is no collision. Further, the value of the ratio (L / glass plate thickness) of the above length L to the thickness of the glass plate provided with the heterogeneous region 50 is preferably 0.001 or more and 1.0 or less, more preferably 0.01 or more and 0.7 or less, and still more preferably 0.05 or more and 0.7 or less. By setting it to 0.001 or more and 1.0 or less, cracks are likely to progress in the thickness direction during a collision with a person, and the laminated glass 1 can be effectively weakened, while ensuring the robustness as an automobile window during normal use when there is no collision.

[0037] The equivalent diameter D of the maximum circle in plan view of the cross section cut in the plane direction of the heterogeneous region 50 (Fig. 5A) is preferably 0.01 μm or more and 200 μm or less, more preferably 0.1 μm or more and 200 μm or less, still more preferably 1 μm or more and 200 μm or less, even more preferably 10 μm or more and 200 μm or less, and particularly preferably 20 μm or more and 150 μm or less. When the shape of the cross section cut in the plane direction of the heterogeneous region 50 is circular, the above equivalent diameter D of the maximum circle is the maximum diameter thereof. By setting the equivalent diameter D of the maximum circle to 0.01 μm or more and 200 μm or less, a tensile stress field can be appropriately formed on the inner surface of the glass plate inside the vehicle, and the function as a starting point of cracks at the time of collision of the heterogeneous region 50 can also be improved. Thus, the effect that the laminated glass 1 cracks appropriately can be improved, and the external visual recognition by the occupants of the automobile 100 is not hindered. Note that the upper limit of 200 μm for the equivalent diameter D of the maximum circle is smaller than the size (500 μm) of black spots allowed by the Japanese Automotive Standards Organization (JASO).

[0038] The value of the ratio (L / D) of the length L in the thickness direction to the equivalent diameter D of the maximum circle of the heterogeneous region 50 is 2 or more and 1000 or less, preferably 2.5 or more and 500 or less, more preferably 2.5 or more and 100 or less, still more preferably 3 or more and 100 or less, even more preferably 5 or more and 100 or less, and particularly preferably 10 or more and 50 or less. By the value of (L / D) of the heterogeneous region 50 being 2 or more, the effect that the laminated glass 1 cracks appropriately at the time of collision can be improved. By the value of (L / D) being 1000 or less, the robustness as an automobile window during normal use when not in collision can be ensured. Also, the external visual recognition by the occupants of the automobile 100 is not hindered.

[0039] In addition, the longitudinal length Li (Figs. 5A to 5C) of the heterogeneous region 50 is preferably 0.1 μm or more and 2000 μm or less, more preferably 1 μm or more and 1000 μm or less, still more preferably 10 μm or more and 1000 μm or less, even more preferably 50 μm or more and 1000 μm or less, and particularly preferably 100 μm or more and 1000 μm or less. By setting the longitudinal length Li of the heterogeneous region 50 itself to be 0.1 μm or more and 2000 μm or less, cracks are likely to progress in the thickness direction during a collision with a person, enabling effective weakening of the laminated glass 1, while ensuring the robustness and external visibility as an automobile window during normal use when not in a collision. The longitudinal direction of the heterogeneous region 50 is the axial direction of the heterogeneous region 50 and may correspond to the irradiation direction of the laser beam during the formation of the heterogeneous region.

[0040] The diameter Di (Figs. 5A to 5C) of the cross section orthogonal to the longitudinal direction of the heterogeneous region 50 is preferably 0.01 μm or more and 200 μm or less, more preferably 0.1 μm or more and 200 μm or less, still more preferably 1 μm or more and 200 μm or less, even more preferably 10 μm or more and 200 μm or less, and particularly preferably 20 μm or more and 150 μm or less. The diameter Di of the heterogeneous region is the equivalent diameter of a circle (the diameter of a circle having the same area) at the position where the cross section orthogonal to the longitudinal direction of the heterogeneous region 50 is the largest. Also, when the shape of the cross section orthogonal to the longitudinal direction of the heterogeneous region 50 is circular, the diameter Di of the heterogeneous region is the diameter at the position where the cross section of the heterogeneous region 50 is the largest. By setting the diameter Di of the heterogeneous region 50 itself to be 0.01 μm or more and 200 μm or less, a tensile stress field can be appropriately formed on the inner surface of the glass plate inside the vehicle, and the function of the heterogeneous region 50 as a starting point for cracking during a collision can also be improved, thus improving the effect that the laminated glass 1 cracks appropriately.

[0041] The aspect ratio of the heterogeneous region 50, that is, the value of the ratio (Li / Di) of the longitudinal length Li to the diameter Di, may be 2 or more and 1000 or less, preferably 2.5 or more and 500 or less, more preferably 2.5 or more and 100 or less, still more preferably 3 or more and 100 or less, even more preferably 5 or more and 100 or less, and particularly preferably 10 or more and 50 or less. When the value (aspect ratio) of (Li / Di) of the heterogeneous region 50 is 2 or more, the effect that the laminated glass 1 breaks appropriately at the time of collision can be improved. When the value of (Li / Di) is 1000 or less, the robustness as an automobile window during normal use when not in collision can be ensured. Also, it does not prevent the occupants of the automobile 100 from visually recognizing the outside.

[0042] In addition, in the example shown in FIG. 5A, the length L in the thickness direction of the heterogeneous region 50 is also the longitudinal length Li of the heterogeneous region 50 itself. Also, the diameter D corresponding to the maximum circle in the plan view of the heterogeneous region 50 is also the diameter Di of the heterogeneous region 50 itself.

[0043] The longitudinal direction of the elongated heterogeneous region 50 may be parallel to the thickness direction (the normal direction when the glass plate is curved), as shown in FIG. 5A, or may form an angle of more than 0° and 60° or less, as shown in FIG. 5B. In this specification, parallel includes a direction inclined within 10° from perfect parallel.

[0044] Here, FIG. 5B shows another example of the heterogeneous region, in which the longitudinal direction or the direction of the axis Ax of the heterogeneous region 50 forms an angle θ with respect to the thickness direction or the normal N. Such an inclined heterogeneous region can be formed, for example, by inclining the irradiation angle of a laser with respect to the normal direction of the glass plate surface. The laser irradiation angle can be adjusted, for example, by using a scanning device such as a galvanometer scanner.

[0045] From the perspective of effectively weakening the laminated glass 1, the longitudinal directions of the plurality of heterogeneous regions 50 may preferably be aligned parallel to the thickness direction or the normal direction. On the other hand, from the perspective of improving the visibility outside the vehicle by scattering the external light incident on the heterogeneous regions in various directions, preferably, the longitudinal directions of the plurality of provided heterogeneous regions 50 are not aligned and are different, and more preferably, there may be a distribution within a range where the angle θ is more than 0° and 60° or less. Further, as another example, from the perspective of making it difficult to see the heterogeneous region itself and ensuring visibility, the longitudinal direction of the elongated heterogeneous region 50 may be parallel to the horizontal direction in the state of being assembled to the vehicle. Also, in the state of being assembled to the vehicle, it can be parallel to the direction along the line of sight from the position of the occupant's eyes toward the laminated glass 1. Thereby, the size of the heterogeneous region as viewed from the occupant's field of view can be minimized, and the influence on visibility can be reduced.

[0046] Furthermore, FIG. 5C shows an example of the structure of a modified example of the heterogeneous region 50. FIG. 5C is a schematic cross-sectional view of the glass plate cut in the thickness direction at the position of the heterogeneous region 50, similar to FIGS. 5A and 5B. As shown in FIG. 5C, the heterogeneous region 52(50) may be a region including a central heterogeneous portion 52a(50a) located at the center in the heterogeneous region 52(50) and cracks 52c(50c) formed around it. In the example shown in FIG. 5C, the central heterogeneous portion 50a is a concave portion formed by removing the material constituting the glass plate from the surface of the glass plate. The number of cracks formed in the heterogeneous region 50 may be one or a plurality. Also, the crack 50c preferably includes a crack formed so as to extend from the inner surface of the central heterogeneous portion 50a to the periphery, and further may include a crack formed at a distance from the central heterogeneous portion 50a. The crack formed at a distance from the central heterogeneous portion 50a may be formed, for example, at a distance from the central heterogeneous portion 50a in the thickness direction and may be formed on the axis of the heterogeneous region 50. Also, the crack in the heterogeneous region preferably includes a crack reaching the surface of the glass plate.

[0047] In the heterogeneous region 50 where a crack 50c is formed around the central heterogeneous portion 50a, the length L in the thickness direction of the heterogeneous region 50 may be the length from the inner surface of the glass plate to the deepest position where the crack 50c extends, and the equivalent circle diameter D in plan view of the heterogeneous region 50 may be the diameter of the smallest circle within which the range where the crack 50c extends is contained in plan view.

[0048] The above-mentioned central heterogeneous portion 50a is a portion directly formed by irradiation with a laser for forming the heterogeneous region 50 and may have a diameter Da having a size close to the irradiation diameter of the laser. In contrast, the crack 50c can be generated immediately during or after the formation of the central heterogeneous portion 50a by laser irradiation. When the central heterogeneous portion 50a is a concave portion, the concave portion may be an ablation portion formed by laser ablation.

[0049] The equivalent circle diameter Da in plan view of the central heterogeneous portion 50a, that is, the diameter of a circle having the same area as the plan view area of the central heterogeneous portion 50a, may preferably be 10 μm or more and 200 μm or less, more preferably 20 μm or more and 100 μm or less. Also, the length La in the thickness direction of the central heterogeneous portion 50a may preferably be more than 0 μm and 200 μm or less, more preferably 5 μm or more and 50 μm or less. Also, the ratio value (La / Da) may preferably be 1 or less, more preferably 0.8 or less. Also, the lower limit of (La / Da) is not particularly limited, and (La / Da) may be more than 0, for example, 0.05 or more.

[0050] The position (depth position) in the thickness direction of the heterogeneous region 50 is preferably a depth of 0 μm or more and 200 μm or less from the inner surface. The depth position refers to the length from the inner surface of the glass plate to the closer end of the heterogeneous region 50 to the inner surface of the glass plate as viewed in the thickness direction. When the depth position is 0 μm, the heterogeneous region 50 reaches the inner surface. When the heterogeneous region 50 reaches the inner surface, its function can be exerted on the surface of the glass plate, and appropriate cracking during a collision is promoted, which is preferable.

[0051] Note that, in the first heterogeneous region 51 and the second heterogeneous region 52, one or more of the shape, the length L in the thickness direction, the equivalent diameter D of the maximum circle, the length Li in the longitudinal direction of the heterogeneous region itself, the diameter Di, and the inclination angle θ and its distribution state may be the same or different.

[0052] When the glass plates 10 and 20 constituting the laminated glass 1 are float glass, it is preferable that the heterogeneous regions 50, 50,... are formed in the vicinity of the surface (hereinafter referred to as the bottom surface) that was in contact with the molten metal, for example, molten tin or a molten tin alloy, during manufacturing, out of the two main surfaces of the glass plate 10. This will be described below.

[0053] The float process is a method of forming molten glass by floating it on a molten metal such as molten tin in a float bath. Here, the bottom surface that was in contact with the molten tin contains tin near the surface, but the main surface on the opposite side of the bottom surface, which was not in contact with the molten tin, hardly contains tin. On the top surface that hardly contains tin, the ion exchange reaction between sodium ions in the glass and hydrogen ions in the outside air proceeds, and a surface hydration layer is gradually formed. Since the surface hydration layer has a low hardness, the top surface gradually reduces its brittleness over time, and cracks are less likely to be generated and grow. Therefore, even if the heterogeneous regions 50, 50,... are formed on the top surface side, the fracture strength increases over time. As a result, when a pedestrian or the like collides with the vehicle, it becomes difficult for the laminated glass 1 to start cracking, and the function of protecting people may be insufficient. On the other hand, on the bottom surface containing tin, the ion exchange reaction between hydrogen ions and sodium ions is inhibited by the effect of tin, which is an asymmetric ion, so the formation of the surface hydration layer hardly proceeds. Therefore, by forming the heterogeneous regions 50, 50,... in the vicinity of the bottom surface, the fracture strength hardly changes over time, and the function of protecting people is maintained over a long period.

[0054] From the above, in this embodiment, it is desirable to form heterogeneous regions 50, 50,... in the vicinity of the bottom surface containing a large amount of tin. In the manufacture of the laminated glass 1, the glass plates 10 and 20 are preferably arranged such that the surfaces on the vehicle interior side (the second surface F2 and the fourth surface F4) become the bottom surface, respectively. Further, on the bottom surface containing a large amount of a metal such as tin, the light absorption rate in the UV region is particularly improved advantageously. For this reason, when forming the heterogeneous regions 50, 50,..., there is also an advantage that the treatment can be performed with irradiation of lower energy by performing laser irradiation from the bottom surface side.

[0055] Incidentally, the bottom surface containing a large amount of tin and the top surface containing almost no tin can be discriminated, for example, by measuring the tin concentrations on both surfaces using a tin surface measuring instrument TinCheck manufactured by Bohle Co., Ltd. Further, on the bottom surface, a tin-containing layer having a thickness of 5 to 15 μm can be detected by quantitatively measuring the tin concentration using a fluorescent X-ray method or an EPMA method.

[0056] Further, when obtaining the distribution of the strength (fracture stress) (the calculation method will be described later) of the surfaces on the vehicle interior side (the second surface F2 and / or the fourth surface F4) of the glass plates of the laminated glass 1 obtained according to this embodiment, the maximum value of the strength may preferably be 350 MPa or less, more preferably 250 MPa or less. Further, the minimum value of the strength may preferably be 60 MPa or more, more preferably 80 MPa or more. When the maximum value is 350 MPa or less, the laminated glass 1 is appropriately likely to break at the time of a collision, and the effect of reducing the impact on a person can be improved. When the minimum value is 60 MPa or more, the breakage of the laminated glass 1 due to flying stones can be suppressed.

[0057] FIG. 6 shows a modified example of the arrangement of the heterogeneous regions 50, 50,.... As shown in the example of FIG. 6, the first heterogeneous regions 51, 51,... and the second heterogeneous regions 52, 52,... may be arranged so as to overlap in plan view. In other words, both the first heterogeneous region 51 and the second heterogeneous region 52 may be arranged on a single straight line Z parallel to the thickness direction. When the first heterogeneous region 51 and the second heterogeneous region 52 overlap in plan view, cracks are likely to progress in the thickness direction during a collision between the automobile 100 and the person 200, which is preferable.

[0058] As described above, the heterogeneous regions 50, 50,... are formed using a laser. Since the laser beam has high directivity or convergence and can irradiate with a small spot diameter (diameter at the focused position), a minute region can be locally heated to form the heterogeneous region 50 with precise size and arrangement. FIG. 7 schematically shows a laser beam irradiation device 300 for forming the heterogeneous regions 50, 50,.... The laser beam LB emitted from the laser beam irradiation device 300 is irradiated onto the main surface of the glass plate. In the example shown in FIG. 7, the laser beam LB is irradiated from the vehicle interior side (side of the fourth surface F4) of the laminated glass 1, but it may also be irradiated from the vehicle exterior side (side of the first surface F1) of the laminated glass 1, or irradiated from both sides.

[0059] The laser beam LB is irradiated under conditions such that it can be focused inside the glass plate. More specifically, it is irradiated under conditions such that it can be focused in the vicinity of the second surface F2 inside the first glass plate and / or in the vicinity of the fourth surface F4 inside the second glass plate. Thereby, the inside of the glass plate is preferentially heated, and minute regions inside the glass plate are made heterogeneous to form the heterogeneous region.

[0060] In the irradiation of the laser beam LB, either non - linear absorption or linear absorption may be utilized. When non - linear absorption is utilized, the photon density is 1×10 8 W / cm 2 or more and 1×10 14 W / cm 2The following may be the case. In non-linear absorption, multi-photon absorption occurs. The probability of multi-photon absorption is non-linear absorption, and the higher the photon density, the exponentially higher it becomes. For example, the probability of two-photon absorption is proportional to the square of the photon density. In the case of non-linear absorption, by selecting a wavelength with low linear absorption, selective light absorption can be achieved only in the condensing part, so it is easy to form the heterogeneous region 50 at a deep position inside the glass plate.

[0061] On the other hand, in linear absorption, one-photon absorption occurs at any position in the thickness direction of the glass plate depending on the photon density. One-photon absorption is proportional to the photon density. Also, the intensity of the laser light LB decays according to Lambert-Beer's law. That is, assuming that the intensity of the laser light LB changes from I0 to I while the laser light LB travels a distance E (unit: [cm]) in the glass plate, if the absorption coefficient of the glass plate is α (unit: [cm -1 ), the equation I = I0×exp(-α×E) holds. From the viewpoint of absorbing the laser light LB inside the glass plate, it is preferable to irradiate the laser light LB so that the absorption coefficient α is greater than 0 and less than 100. In the case of linear absorption, for example, even in the case of colored glass, it is easy to control the size and shape of the heterogeneous region 50 by appropriately selecting the absorption coefficient α. Also, in linear absorption, it is easy to form a heterogeneous region on the surface of the glass plate.

[0062] The wavelength of the laser light LB depends on the composition of the glass plate included in the laminated glass 1 and the like, but as described above, it is preferable that the laser light LB has a wavelength that can be at least partially transmitted so that the inside of the glass plate can be heated. More specifically, the wavelength of the laser light LB may be 250 nm or more and 5000 nm or less, and preferably 310 nm or more and 3000 nm or more. At wavelengths in the above range, the absorption coefficient α can be set within an appropriate range, and the presence or absence and degree of ablation can also be adjusted.

[0063] As the light source of the laser beam, for example, near-infrared lasers such as Yb fiber lasers (wavelength: 1000 nm or more and 1100 nm or less), Yb disk lasers (wavelength: 1000 nm or more and 1100 nm or less), Nd:YAG lasers (wavelength: 1064 nm), high-power semiconductor lasers (wavelength: 808 nm or more and 980 nm or less), etc. can be mentioned. Further, the light source of the laser beam may be a UV laser (wavelength: 310 nm or more and 360 nm or less), a green laser (wavelength: 510 nm or more and 540 nm or less), a Ho:YAG laser (wavelength: 2080 nm), an Er:YAG laser (2940 nm), a laser using a mid-infrared optical parametric oscillator (wavelength: 2600 nm or more and 3450 nm or less), etc. It may also be a LD pumped solid state (DPSS) laser combined with a wavelength conversion element.

[0064] Note that the laser beam LB may be irradiated in a pulse oscillation mode or a continuous oscillation mode. However, in the pulse oscillation mode, it is preferable from the viewpoint of reducing unintentional damage to the vicinity of the irradiation part. Also, the operation mode of the pulse is not particularly limited, but the burst pulse mode is preferable because high-power irradiation can be performed, so the irradiation time can be shortened. In the case of the pulse oscillation mode, a nanosecond pulse laser, a picosecond pulse laser, a femtosecond pulse laser, etc. can be used.

[0065] As other conditions for laser beam irradiation, it may be 0.0001 ns or more and 100 ns or less, pulse energy 10 μJ or more and 1000 μJ or less, irradiation times 1 time or more and 1000 times or less, and repetition frequency 1 kHz or more and 10000 kHz or less. Also, the irradiation angle of the laser beam (the angle with respect to the normal direction of the main surface of the glass plate at the irradiation position) can be set to the irradiation angle corresponding to the inclination angle θ (FIG. 5B) of the heterogeneous region 50 to be formed. The irradiation angle of the laser beam and the inclination angle θ of the heterogeneous region 50 will have different values due to the refraction of the laser beam on the glass plate surface. The difference in angles can be easily calculated from the refractive index of the glass plate. The plurality of heterogeneous regions 50, 50,... on the main surface of the glass plate can be formed while changing the irradiation angle of the laser beam.

[0066] When forming the heterogeneous regions 50, 50, …, while moving the relative position of the laser beam LB with respect to the alignment glass 1, the laser beam is intermittently irradiated at a plurality of predetermined positions. For example, the alignment glass 1 can be fixed in position and the laser beam irradiation device 300 can be scanned in the plane direction. At this time, it is preferable to use a scanner (scanning device) such as a galvanometer scanner or a polygon scanner. By using the scanning device, the irradiation position of the laser beam LB can be arbitrarily changed three-dimensionally. Therefore, even for a curved glass plate, for example, it is possible to reliably irradiate the laser beam LB at a predetermined position.

[0067] When forming heterogeneous regions on both the first glass plate 10 and the second glass plate 20, the laser beam LB is scanned across the transmission region 5 to form the first heterogeneous regions 51, 51, … in the first glass plate 10, and then the laser beam LB is scanned across the transmission region 5 again to form the second heterogeneous regions 52, 52, … in the second glass plate 20. The formation order of the first heterogeneous regions 51, 51, … and the second heterogeneous regions 52, 52, … may be reversed.

[0068] Also, the scanning of the laser beam LB required to obtain the final product, the alignment glass 1, can be performed once to form heterogeneous regions on both the first glass plate 10 and the second glass plate 20. In that case, during one scan, the laser beam LB is focused at two or more different positions in the optical axis direction of the laser beam LB, that is, both inside the first glass plate 10 and inside the second glass plate 20. Specifically, it is preferable to focus and irradiate the laser beam LB using a multi-focus lens or a multi-focus diffractive optical element. Thereby, the time required for scanning the laser beam LB can be shortened. This method is suitable for obtaining a configuration (FIG. 6) in which the first heterogeneous region 51 and the second heterogeneous region 52 are arranged so as to overlap in plan view.

[0069] Note that, as shown in FIGS. 5A and 5B, the laminated glass 1 according to the present embodiment is in a form in which ablation by laser light does not occur or hardly occurs, that is, the irradiation with the laser light LB can be performed under conditions where ablation does not occur or hardly occurs in the glass plate. Ablation refers to a phenomenon in which a part of the material of the glass plate is removed from the surface of the glass plate by irradiation with the laser light LB. When ablation occurs, the surface of the glass plate becomes rough, which may interfere with the visual recognition of the outside of the vehicle through the laminated glass 1. However, in the present embodiment, the conditions of the laser light LB irradiation can be adjusted so that ablation does not occur, and in that case, the above-described interference with the visual recognition can be reduced. Note that, in the laminated glass 1 according to the present embodiment, "hardly any ablation by laser light occurs" includes the case where ablation having a depth of less than 1 μm occurs due to the laser light.

[0070] On the other hand, in the laminated glass 1 according to the present embodiment, ablation by laser light may occur. For example, as described with reference to FIG. 5C, the central heterogeneous portion 50a in the heterogeneous region 50 may be formed as an ablation portion. When the central heterogeneous portion 50a is an ablation portion, for example, when compared with a heterogeneous region such as a melting mark, there is an advantage that the central heterogeneous portion 50a can be easily recognized by normal inspection means during inspection of the product, and the inspection becomes easy.

[0071] In the laminated glass 1 according to the present embodiment, at least in the see-through region 5, the arithmetic mean roughness Ra of the roughness curve defined in JIS B 0601-2013 of the second surface F2 of the first glass plate 10 and the fourth surface F4 of the second glass plate 20 can be 0.1 nm or more and 1000 nm or less.

[0072] As described above, the heterogeneous region 50 in the laminated glass 1 according to the present embodiment may be a region including the central heterogeneous portion 50a and the crack 50c formed around it (FIG. 5C). When the heterogeneous region 50 is formed, the central heterogeneous portion is directly formed by laser irradiation as described above, and the crack is formed simultaneously with or immediately after the formation.

[0073] Here, with reference to FIGS. 8 and 9, the formation of cracks in the heterogeneous region 50 having the cylindrical central heterogeneous portion 50a will be described as an example. FIG. 8 shows the state at the time when the central heterogeneous portion 50a is formed by laser irradiation and at the same time or immediately after the formation of the central heterogeneous portion 50a when cracks occur, and FIG. 9 shows the state after the state of FIG. 8 where the crack 50c has progressed. FIGS. 8(a) and 9(a) are perspective views of a portion of the glass plate including the central heterogeneous portion 50a, and FIGS. 8(b) and 9(b) are views of the surface of the glass plate as seen from above. Tensile stress is generated in the minute central heterogeneous portion 50a formed by heating due to the irradiation of laser light. Compressive stress is generated in the surrounding affected region 50b to counteract the tensile stress, and further tensile stress is generated around it, and the crack 50c is generated by the tensile stress (FIG. 8). The crack 50c may have a length in the thickness direction. Thereafter, the crack 50c progresses from the affected region 50b into the central heterogeneous portion 50a while causing stress relaxation of the glass plate (FIG. 9).

[0074] In this way, by including the crack 50c generated in the laminated glass 1 due to the central heterogeneous portion 50a, the start of cracking during a collision between an automobile and a person is further promoted, and the effect that the laminated glass 1 cracks appropriately is improved.

[0075] One embodiment of the present invention is a method for manufacturing a glass plate for an automobile window, including forming a plurality of heterogeneous regions spaced apart in a plane direction by a laser near the surface on the vehicle interior side of the glass plate within the glass plate, and the value of the ratio of the length in the thickness direction to the diameter equivalent to a circle in plan view of the heterogeneous region is 2 or more and 1000 or less. It may be a method for manufacturing a glass plate for an automobile window.

[0076] Further, an embodiment of the present invention is a method for manufacturing laminated glass for an automotive window, comprising a first glass plate, an intermediate film, and a second glass plate in this order from the outside of the vehicle toward the inside of the vehicle, including forming a plurality of heterogeneous regions spaced apart in a plane direction using a laser near the surface on the inside of the vehicle of the first glass plate and / or near the surface on the inside of the vehicle of the second glass plate, wherein a value of a ratio of a length in a thickness direction to a diameter equivalent to a circle in a plan view of the heterogeneous region is 2 or more and 1000 or less.

[0077] Further, an embodiment of the present invention is a method for manufacturing laminated glass for an automotive window, comprising a first glass plate, an intermediate film, and a second glass plate in this order from the outside of the vehicle toward the inside of the vehicle, including forming a plurality of heterogeneous regions spaced apart in a plane direction using a laser near the surface on the inside of the vehicle of the first glass plate and / or near the surface on the inside of the vehicle of the second glass plate, wherein a value of a ratio of a length in a longitudinal direction to a diameter of a cross-section orthogonal to the longitudinal direction of the heterogeneous region is 2 or more and 1000 or less.

[0078] In the method for manufacturing laminated glass for an automotive window described above, the formation of the heterogeneous region may be performed after the first glass plate and the second glass plate are overlapped via the intermediate film. In that case, the irradiation conditions of the laser light, particularly the wavelength of the laser, are adjusted so that the absorption rate of the laser light in the first glass plate and / or the second glass plate is greater than the absorption rate of the laser light in the intermediate film. According to the above method, when the first heterogeneous regions 51, 51,... are formed in the first glass plate 10 and the second heterogeneous regions 52, 52,... are formed in the second glass plate 20, displacement of their positions in a plan view can be prevented.

[0079] Furthermore, in the method for manufacturing laminated glass for an automotive window described above, the laser can be irradiated after bending the first glass plate and the second glass plate irradiated with the laser. Thereby, in the bending process, it is possible to prevent the shape and size of the heterogeneous regions 50, 50,... from being affected and the functions of the heterogeneous regions 50, 50,... from becoming non-uniform depending on the location in the plane direction.

Example

[0080] The experimental data will be described below. In the following experimental examples, Examples 1 to 5 are examples, and Example 6 is a comparative example.

[0081] <Preparation of Samples for Measuring Fracture Stress> (Example 1) In the same manner as in the normal mass production process, a glass sample (100 mm × 100 mm × 2 mm thick) was cut out from a soda-lime silicate glass plate obtained by the float method, and laser irradiation was performed on one point at the in-plane center of the glass sample from the top surface side. As a result, one heterogeneous region was formed near the bottom surface of the glass sample. Table 1 shows the laser irradiation conditions. Among the irradiation conditions, the "number of irradiations" is the number of times of laser irradiation. The "irradiation angle" is the angle with respect to the normal direction of the top surface (Example 1) or the bottom surface (Examples 2 to 5) of the glass plate at the irradiation position. An irradiation angle of 0° means that the irradiation is performed in the normal direction of the incident surface (top surface or bottom surface). In Example 1, the heterogeneous region was formed by laser irradiation with an irradiation angle of 0°.

[0082] The laser processing apparatus used for laser irradiation was composed of a laser light irradiation apparatus (LD-excited solid laser) and a galvanometer scanner which is a scanning apparatus. Although the laser processing apparatus itself was fixed in position, an apparatus capable of irradiating laser light at various angles was used. The aperture ratio of the lens and the working distance were set so that the spot diameter of the laser light on the glass plate surface became 32 μm at the 1 / e diameter. 2 The aperture ratio of the lens and the working distance were set so that the spot diameter of the laser light on the glass plate surface became 32 μm at the 1 / e diameter.

[0083] The glass sample after laser irradiation was placed in an electric heating furnace, and a heat treatment at 658 °C for 200 seconds was performed as a heat treatment equivalent to the normal bending process.

[0084] (Examples 2 to 5) Except for changing the laser irradiation conditions as shown in Table 1 (including changing the laser incident surface to the bottom surface), glass samples of Examples 2 to 5 were obtained in the same manner as in Example 1. In Example 5, a heterogeneous region was formed by laser irradiation at an irradiation angle of 28.00°. As a result, a heterogeneous region with an axial direction inclined at 17.78° with respect to the normal direction of the glass plate surface was obtained.

[0085] (Example 6) A glass sample was obtained in the same manner as in Example 1 except that no laser was irradiated.

[0086] <Measurement of the shape of the heterogeneous region> The heterogeneous region formed near the bottom surface of the glass sample of each example was photographed from the bottom surface side where the heterogeneous region was formed using a digital microscope VHX-6000 manufactured by Keyence Corporation. Based on the photographed image, the diameter Di of the heterogeneous region was determined. Furthermore, the contour of the heterogeneous region in the cross-section cut in the thickness direction of the glass plate was determined by one-dimensional analysis using a laser microscope VK-X3000 manufactured by Keyence Corporation, and based on this analysis, the length Li of the heterogeneous region was determined. In Examples 1 to 4, since there is no inclination of the heterogeneous region, the length Li in the longitudinal direction of the heterogeneous region and the length L in the thickness direction are the same, and the diameter Di of the cross-section orthogonal to the longitudinal direction of the heterogeneous region and the equivalent diameter D in plan view are the same. The results are shown in Table 1.

[0087] <Measurement of strength (fracture stress)> Ten glass samples (100 mm × 100 mm × thickness 2 mm) prepared as described above were used, and the strength of each glass sample was measured as the fracture stress (MPa). The fracture stress was measured according to ISO1288-5 (2016) using R30. Specifically, a support ring with a diameter of 60 mm and a load ring with a diameter of 12 mm were used, and a load was applied by the load ring at a load rate of 0.3 mm per minute, and the fracture load was measured. The load was applied from the top surface side by arranging the load ring on the top surface side of the glass plate. Furthermore, the fracture stress was determined using the formula described in ISO1288-5 (2016). The results are shown in Table 1.

[0088] From the strength data of the above 10 glass samples, the maximum and minimum values were recorded, and the average value was calculated and recorded.

[0089] As shown in Table 1, in Examples 1 to 5 where a heterogeneous region having a shape with a ratio of length to diameter (Li / Di) of 2 to 1000 was provided, the maximum value of the fracture stress was 350 MPa or less, and the minimum value was 60 MPa or more. On the other hand, in Example 6 where no heterogeneous region was provided, the maximum value of the fracture stress exceeded 350 MPa.

[0090] <Preparation of Samples for External Visibility Evaluation> A glass sample (300 mm × 300 mm × 2 mm thick) was cut out from a glass plate of a soda-lime silicate glass composition obtained by the float method, and laser irradiation was performed from the top surface side (Example 1) or the bottom surface side (Examples 2 to 5). The irradiation was performed intermittently at 81 points scattered in a square lattice pattern with a pitch of 30 mm. The laser irradiation conditions were as shown in Table 1. The glass sample after laser irradiation was placed in an electric heating furnace, and heat treatment at 658°C for 200 seconds was performed as heat treatment equivalent to a normal bending process.

[0091] Two glass samples that had been laser-irradiated and heat-treated were stacked with their bottom surfaces aligned (with the bottom surfaces of both glass samples facing upward), and laminated through an intermediate film (PVB resin) and pressed together to form laminated glass. A laminated glass sample in which a 2-mm-thick glass sample, a 0.76-mm-thick intermediate film, and a 2-mm-thick glass sample were laminated was obtained. Example 6 was the same as Examples 1 to 5 except that no laser irradiation was performed, and a laminated glass sample was obtained.

[0092] <External Visibility Evaluation> The obtained laminated glass was placed at a position 400 mm away with the inner surface of the glass plate on the vehicle interior side facing the face of the evaluator, and the visibility of the image on the opposite side (the vehicle exterior side) of the laminated glass was evaluated when looking at the image under natural light. The evaluation criteria were as follows. ◎: No bright spots are visible at all. 〇: There are some places where faint bright spots are visible. △: Periodic bright spots can be faintly seen throughout. ×: Periodic bright spots can be strongly seen throughout. The evaluation of each example is shown in Table 1.

[0093]

Table 1

[0094] According to the above, a laminated glass for automotive windows in which a plurality of different regions of Examples 1 to 5 formed by a laser are provided spaced apart in the plane direction near the inner surface of the first glass plate and / or the second glass plate can provide a technology that reduces the impact on a person during a collision between an automobile and a person while not obstructing the view of the outside of the automobile by the occupants of the automobile.

[0095] This application claims priority based on Japanese Patent Application No. 2022-032932 filed on March 3, 2022, and the entire contents thereof are incorporated herein by reference.

Explanation of Reference Numerals

[0096] 1 Laminated glass 2 Vehicle body 5 Transparent region 10 First glass plate 20 Second glass plate 30 Intermediate film 40 Shielding layer 50 Different region 50a Central different part (concave part) 50b Influence region 50c Crack 51 First different region 52 Second different region 100 Automobile 200 Person 300 Laser light irradiation device F1 First surface F2 Second surface F3 Third surface F4 Fourth surface LB Laser light

Claims

1. An automotive laminated glass for a window, comprising, in this order from the outside of the vehicle to the inside of the vehicle, a first glass plate, an intermediate film, and a second glass plate, a plurality of heterogeneous regions formed by a laser are provided at intervals in the plane direction near the surface on the inside of the vehicle of the first glass plate and / or the second glass plate, The automotive laminated glass for a window, wherein a value of a ratio of a length in the thickness direction to a diameter equivalent to a circle in a plan view of the heterogeneous region is 2 or more and 1000 or less.

2. The automotive laminated glass for a window according to claim 1, wherein the diameter equivalent to a circle in a plan view of the heterogeneous region is 0.01 μm or more and 200 μm or less, and the length in the thickness direction is 0.1 μm or more and 2000 μm or less.

3. An automotive laminated glass for a window, comprising, in this order from the outside of the vehicle to the inside of the vehicle, a first glass plate, an intermediate film, and a second glass plate, a plurality of heterogeneous regions formed by a laser are provided at intervals in the plane direction near the surface on the inside of the vehicle of the first glass plate and / or the second glass plate, The automotive laminated glass for a window, wherein a value of a ratio of a length in the longitudinal direction to a diameter of a cross section orthogonal to the longitudinal direction of the heterogeneous region is 2 or more and 1000 or less.

4. The automotive laminated glass for a window according to claim 3, wherein the diameter of the heterogeneous region is 0.01 μm or more and 200 μm or less, and the length is 0.1 μm or more and 2000 μm or less.

5. The plurality of heterogeneous regions include inclined heterogeneous regions, The automotive laminated glass for a window according to claim 3, wherein a longitudinal direction of the inclined heterogeneous region forms an angle of more than 0° and 60° or less with respect to a normal direction of a main surface of the first glass plate and / or the second glass plate on which the heterogeneous region is provided.

6. The angle of the longitudinal direction of the plurality of heterogeneous regions with respect to the normal direction of the main surface of the first glass plate and / or the second glass plate on which the heterogeneous region is provided is distributed within a range of 0° or more and 60° or less. The laminated glass for automotive windows according to claim 5.

7. The pitch in the plane direction of the heterogeneous region is 1 mm or more and 200 mm or less. The laminated glass for automotive windows according to claim 1 or 3.

8. The heterogeneous region is at least a region where the virtual temperature is different from that of the region around the heterogeneous region. The laminated glass for automotive windows according to claim 1 or 3.

9. The first glass plate and / or the second glass plate on which the heterogeneous region is provided is float glass, The heterogeneous region is provided in the vicinity of the molten metal contact surface of the float glass. The laminated glass for automotive windows according to claim 1 or 3.

10. The heterogeneous region extends to the inner surface of the vehicle. The laminated glass for automotive windows according to claim 1 or 3.

11. The first glass plate and the second glass plate have the heterogeneous region, The heterogeneous region formed on the first glass plate and the heterogeneous region formed on the second glass plate overlap in a plan view. The laminated glass for automotive windows according to claim 1 or 3.

12. The laminated glass for automotive windows according to claim 1 or 3, and A vehicle body including an opening to which the laminated glass for automotive windows is attached. An automobile.

Images