Laminated glass and method for producing laminated glass

Abstract

The present invention provides a laminated glass which has excellent film adhesion between a glass plate and a resin and excellent stone chip resistance. A laminated glass according to the present invention comprises: a first glass plate which has a first main surface and a second main surface that is opposite to the first main surface; a second glass plate which has a third main surface and a fourth main surface that is opposite to the third main surface; and an intermediate film which is sandwiched between the second main surface of the first glass plate and the third main surface of the second glass plate. The developed area ratio Sdr2 of the second main surface is within the range of 0.001-2.5.

Description

Laminated glass and method for manufacturing laminated glass

[0001] The present invention relates to a laminated glass and a method for producing the laminated glass.

[0002] As automobiles become more sophisticated with the advent of autonomous driving technology, there are increasing cases of sensor devices that combine multiple sensors, such as monochrome cameras and millimeter-wave radar, being installed on the inside of the windshield (WS).

[0003] Automotive window shields are relatively easily damaged by stones kicked up by vehicles ahead while driving. When a scratch occurs on the window shield, it must be replaced, but this replacement requires sensor calibration, which increases costs. Therefore, the window shield must function as a cover glass for the sensor equipment, meaning it must be highly resistant to stone chipping.

[0004] Patent Document 1 discloses a resin composition for an interlayer film of laminated glass that can provide laminated glass with high chipping resistance. Patent Documents 2 and 3 disclose glass resin composites that can effectively attenuate the impact energy of flying fragments.

[0005] Japanese Patent Publication No. 2020-040869 Japanese Patent Publication No. 2018-145082 Japanese Patent Publication No. 2018-177601

[0006] On the other hand, for WS, glass with a large area tends to be preferred from the perspective of design, but as the glass area increases, deformation due to deflection increases even under the same indentation load. In laminated glass, as the deformation amount of the glass increases, the deformation amount of the resin used in the interlayer also increases, making the interlayer film more likely to peel off from the outer glass sheet. Therefore, from the perspective of film adhesion, a large contact area between the glass sheet and the resin is preferable, but if the contact area is too large, not only will the optical properties deteriorate, but the probability of cracking due to flying stones as mentioned above will increase. As such, there is a trade-off between film adhesion between the glass sheet and the resin and resistance to flying stone cracking, and it has been difficult to realize laminated glass that combines both performances.

[0007] Therefore, an object of the present invention is to provide a laminated glass having excellent film adhesion between the glass sheets and the resin and excellent resistance to stone chipping, and a method for producing the laminated glass.

[0008] One embodiment of the present invention relates to a laminated glass comprising: a first glass plate having a first main surface and a second main surface opposite the first main surface; a second glass plate having a third main surface and a fourth main surface opposite the third main surface; and an interlayer film sandwiched between the second main surface of the first glass plate and the third main surface of the second glass plate, wherein a developed area ratio Sdr2 of the second main surface is in a range of 0.001 to 2.5.

[0009] Another embodiment of the present invention relates to a method for manufacturing the above-described laminated glass, comprising: abrading the second main surface of a first glass plate, the first glass plate having a first main surface and a second main surface opposite the first main surface, by any one of wet blasting, sandblasting, and sandpaper; and laminating the first glass plate, an interlayer film, and a second glass plate having a third main surface and a fourth main surface opposite the third main surface, in this order, so that the second main surface of the first glass plate and the third main surface of the second glass plate face each other.

[0010] According to the present invention, it is possible to provide laminated glass that has excellent film adhesion between the glass sheet and the resin and excellent resistance to chipping caused by flying stones.

[0011] Fig. 1 is a cross-sectional view of an example of laminated glass according to an embodiment of the present invention. Fig. 2 is a schematic diagram of an indenter used in a collision test. Fig. 3 is a conceptual diagram showing a state in which laminated glass according to an embodiment of the present invention is used as a window glass for an automobile. Fig. 4 is a partial perspective view showing an enlarged view of part S in the automobile shown in Fig. 3. Fig. 5 is a cross-sectional view taken along line Y-Y in Fig. 4.

[0012] Hereinafter, embodiments of the present invention will be described in detail. In the following drawings, components and parts that perform the same function may be described with the same reference numerals, and duplicated descriptions may be omitted or simplified. The embodiments shown in the drawings are schematic to clearly explain the present invention, and do not necessarily accurately represent the size or scale of an actual product. In this specification, "mass" is synonymous with "weight."

[0013] [Laminated Glass] A laminated glass according to an embodiment of the present invention (hereinafter also referred to as "the present embodiment") comprises: a first glass plate having a first main surface and a second main surface opposing the first main surface; a second glass plate having a third main surface and a fourth main surface opposing the third main surface; and an interlayer film sandwiched between the second main surface of the first glass plate and the third main surface of the second glass plate, wherein a developed area ratio Sdr2 of the second main surface is in a range of 0.001 to 2.5.

[0014] FIG. 1 is a diagram showing an example of laminated glass 10 according to this embodiment. The laminated glass 10 includes a first glass sheet 11, a second glass sheet 12, and an interlayer film 13 sandwiched between the first glass sheet 11 and the second glass sheet 12. The first glass sheet 11 has a first main surface S1 and a second main surface S2 opposing the first main surface S1. The second glass sheet 12 has a third main surface S3 and a fourth main surface S4 opposing the third main surface S3. The interlayer film 13 is sandwiched between the second main surface S2 of the first glass sheet 11 and the third main surface S3 of the second glass sheet 12.

[0015] (Thickness of the First Glass Sheet and the Second Glass Sheet) The thickness of the first glass sheet 11 and the thickness of the second glass sheet 12 are preferably the same or greater than the thickness of the second glass sheet 12. If the thickness of the first glass sheet 11 is equal to or greater than the thickness of the second glass sheet 12, when the laminated glass is used, for example, as an automobile windshield, the laminated glass can be arranged so that the first glass sheet 11 is on the outside of the automobile, thereby achieving high impact resistance against flying objects such as pebbles. This is because, when the laminated glass is used in an automobile so that the first glass sheet 11 is on the outside of the automobile, the thickness of the glass sheet arranged on the outside of the automobile is equal to or greater than the thickness of the glass sheet arranged on the inside of the automobile, thereby improving the rigidity of the glass sheet on the side where scratches occur, and consequently improving the impact resistance of the laminated glass. Note that the thickness of the glass sheet in this specification refers to the average thickness of the glass measured using a constant pressure thickness gauge.

[0016] The ratio of the thickness of the first glass sheet 11 to the thickness of the second glass sheet 12 (thickness of the first glass sheet 11 / thickness of the second glass sheet 12) is preferably 1.0 to 6.0. When the ratio is 1.0 or more, stone chip resistance can be improved. Furthermore, when the ratio is 6.0 or less, bending formability can be improved. The ratio is more preferably 1.2 or more, even more preferably 1.4 or more, even more preferably 1.6 or more, and particularly preferably 1.8 or more. Furthermore, the ratio is more preferably 5.9 or less, even more preferably 5.8 or less, even more preferably 5.7 or less, and particularly preferably 5.6 or less.

[0017] The thickness of the first glass sheet 11 is preferably 2.0 to 5.0 mm. When the thickness of the first glass sheet 11 is 2.0 mm or more, high resistance to stone chipping can be obtained. Furthermore, when the thickness of the first glass sheet 11 is 5.0 mm or less, bending formability and pedestrian protection performance can be satisfied. The thickness of the first glass sheet 11 is more preferably 2.2 mm or more, even more preferably 2.4 mm or more, even more preferably 2.6 mm or more, particularly preferably 2.8 mm or more, more preferably 4.9 mm or less, even more preferably 4.8 mm or less, even more preferably 4.7 mm or less, and particularly preferably 4.6 mm or less.

[0018] The thickness of the second glass sheet 12 is preferably 0.5 to 2.5 mm. When the thickness of the second glass sheet 12 is 0.5 mm or more, excellent handleability and high strength can be obtained. Furthermore, when the thickness of the second glass sheet 12 is 2.5 mm or less, a laminated glass with excellent bend formability can be provided. The thickness of the second glass sheet 12 is more preferably 0.6 mm or more, even more preferably 0.8 mm or more, and particularly preferably 1.0 mm or more, and is more preferably 2.0 mm or less, even more preferably 1.9 mm or less, even more preferably 1.8 mm or less, and particularly preferably 1.6 mm or less.

[0019] (Developed Area Ratio) In the laminated glass 10 according to this embodiment, the developed area ratio Sdr2 of the second main surface S2 of the first glass sheet 11 is in the range of 0.001 to 2.5. When the developed area ratio Sdr2 of the second main surface S2 of the first glass sheet 11 is in this range, the contact area between the first glass sheet 11 and the interlayer film 13 is increased, thereby improving adhesion to the resin forming the interlayer film 13. This makes the first glass sheet 11 less likely to peel from the interlayer film 13, suppressing deterioration of optical properties and improving impact resistance when the laminated glass is used in an automobile with the first glass sheet 11 facing the exterior of the automobile. Here, it is sufficient that the developed area ratio Sdr2 of the laminated glass 10 according to this embodiment is in the range of 0.001 to 2.5 in at least 30% of a region 200 mm from the edge of the second main surface S2 of the first glass sheet 11. In the laminated glass 10, the developed area ratio Sdr2 is preferably in the range of 0.001 to 2.5 across the entire region of the second main surface S2 of the first glass sheet 11. The developed area ratio Sdr2 of the second main surface S2 of the first glass sheet 11 is preferably in the range of 0.001 to 2.0, with the lower limit being more preferably 0.002 or more, even more preferably 0.003 or more, and may be 0.005 or more, or even 0.007 or more. The upper limit is more preferably 1.8 or less, and even more preferably 1.5 or less.

[0020] In the laminated glass 10 according to this embodiment, the developed area ratio Sdr3 of the third main surface S3 of the second glass sheet 12 is preferably in the range of 0.001 to 2.5. When the developed area ratio Sdr3 of the third main surface S3 of the second glass sheet 12 is in this range, the contact area between the second glass sheet 12 and the interlayer film 13 is increased, thereby further improving adhesion to the resin forming the interlayer film 13. This makes the second glass sheet 12 less likely to peel from the interlayer film 13, suppressing deterioration of optical properties and further improving impact resistance when the laminated glass is used in an automobile with the first glass sheet 11 facing the exterior of the automobile. Here, in the laminated glass 10 according to this embodiment, it is sufficient that the developed area ratio Sdr3 is in the range of 0.001 to 2.5 in at least 30% of a region 200 mm from the edge of the third main surface S3 of the second glass sheet 12. In the laminated glass 10, the developed area ratio Sdr3 is preferably in the range of 0.001 to 2.5 across the entire region of the third main surface S3 of the second glass plate 11. The developed area ratio Sdr3 of the third main surface S3 of the second glass plate 12 is preferably in the range of 0.001 to 1.5, with the lower limit being more preferably 0.002 or more and even more preferably 0.003 or more, and the upper limit being more preferably 1.4 or less and even more preferably 1.2 or less.

[0021] In this embodiment, the developed area ratio Sdr2 of the second main surface is preferably larger than the developed area ratio Sdr3 of the third main surface. When the developed area ratio Sdr2 of the second main surface is larger than the developed area ratio Sdr3 of the third main surface, the impact resistance of the laminated glass is further increased, and pedestrian protection performance can be improved when the laminated glass is used, for example, in an automobile windshield. The developed area ratio Sdr2 of the second main surface is preferably larger than the developed area ratio Sdr3 of the third main surface by 0.001 or more, and more preferably by 0.005 or more.

[0022] Furthermore, from the viewpoints of the transparency and pedestrian protection performance of the laminated glass, it is preferable that the developed area ratio of the surface of the glass sheet that contacts the interlayer film be larger than that of the surface located on the outer side, and therefore the developed area ratio Sdr2 of the second main surface S2 of the first glass sheet 11 is preferably larger than the developed area ratio Sdr1 of the first main surface S1 of the first glass sheet 11. Furthermore, it is preferable that the developed area ratio Sdr3 of the third main surface S3 of the second glass sheet 12 is larger than the developed area ratio Sdr4 of the fourth main surface S4 of the second glass sheet 12.

[0023] The developed area ratio of each surface of the glass plate is Sdr as defined in ISO25178, and is measured using a laser microscope.

[0024] In order to ensure that the developed area ratio Sdr2 of the second main surface S2 of the first glass sheet 11 and the developed area ratio Sdr3 of the third main surface S3 of the second glass sheet 12 satisfy the above-mentioned ratios, for example, methods of scratching the second main surface and the third main surface using sandblasting, wet blasting, or sandpaper may be used. The scratched area may be 30% or more of an area 200 mm from each edge of the second main surface S2 of the first glass sheet 11 and the third main surface S3 of the second glass sheet 12, or may be the entire area of ​​the second main surface S2 of the first glass sheet 11 and the third main surface S3 of the second glass sheet 12.

[0025] (Chipping Size) The average chipping size on the edge surface of the first glass sheet 11 in the laminated glass 10 according to this embodiment is preferably 40 μm or less. When the average chipping size on the edge surface of the first glass sheet 11 is 40 μm or less, edge processability is improved. The average chipping size on the edge surface of the first glass sheet 11 is more preferably 38 μm or less, even more preferably 37 μm or less, and particularly preferably 35 μm or less. The average chipping size on the edge surface of the first glass sheet 11 in the laminated glass 10 according to this embodiment may be 5 μm or more, 6 μm or more, or 7 μm or more. That is, the average chipping size on the edge surface of the first glass sheet 11 is preferably in the range of 5 to 40 μm.

[0026] In order to bring the average size of chipping on the edge surface of the first glass plate 11 in the laminated glass 10 according to this embodiment into the above range, for example, methods include adjusting the grit size of the grinding wheel used to process the edge surface and adjusting the processing speed.

[0027] Here, chipping on the edge of the first glass sheet 11 in the laminated glass 10 according to this embodiment refers to chipping that occurs at the boundary between the first main surface S1 or the second main surface S2 and the edge when the edge of the laminated glass 10 is processed into a C-chamfered shape (C0.1, angle 45°) using a #230 electroplated grinding wheel at a grinding wheel rotation speed of 10,000 rpm and a feed rate of 200 mm / min. Details of the measurement method will be described later in the examples. Note that "C0.1, angle 45°" in the C-chamfered shape means that the corner of the edge of the laminated glass 10 is cut off by 0.1 mm at an angle of 45° relative to the edge.

[0028] In the laminated glass 10 according to this embodiment, the average size of chipping on the edge surface of the second glass sheet 12 is preferably 40 μm or less. Having an average size of chipping on the edge surface of the second glass sheet 12 of 40 μm or less reduces thermal cracking. The average size of chipping on the edge surface of the second glass sheet 12 is more preferably 39 μm or less, even more preferably 38 μm or less, even more preferably 37 μm or less, and particularly preferably 35 μm or less. In the laminated glass 10 according to this embodiment, the average size of chipping on the edge surface of the second glass sheet 12 may be 5 μm or more, 7 μm or more, or 10 μm or more. That is, the average size of chipping on the edge surface of the second glass sheet 12 is preferably in the range of 5 to 40 μm.

[0029] In order to bring the average size of chipping on the edge surface of the second glass sheet 12 in the laminated glass 10 according to this embodiment into the above range, for example, methods such as improving the mechanical properties of the glass, slowing down the edge surface processing speed, or increasing the fictive temperature of the glass can be used.

[0030] Here, chipping on the edge surface of the second glass sheet 12 in the laminated glass 10 according to this embodiment refers to chipping that occurs at the boundary between the third principal surface S3 or the fourth principal surface S4 and the edge surface when the edge surface of the laminated glass 10 is processed into a C-chamfered shape (C0.1, angle 45°) using a #230 electroplated grinding wheel at a grinding wheel rotation speed of 10,000 rpm and a feed rate of 200 mm / min. Details of the measurement method will be described later in the examples.

[0031] (Fracture Toughness Value) The fracture toughness value K of the first glass plate 11 in the laminated glass 10 according to this embodiment ＩＣ is 0.7 MPa m １／２ The fracture toughness value K of the first glass plate 11 is preferably equal to or greater than 100%. ＩＣ is 0.7 MPa m １／２ By satisfying the above, high resistance to flying stones can be achieved. ＩＣ is 0.71 MPa m １／２ More preferably, 0.72 MPa m １／２ More preferably, 0.73 MPa m １／２ The above is particularly preferable. ＩＣ is 1.0 MPa m from the viewpoint of pedestrian protection performance. １／２ Preferably, 0.97 MPa m or less １／２ More preferably, 0.95 MPa m １／２ More preferably, the fracture toughness value K of the first glass plate 11 is: ＩＣ is 0.7 to 1.0 MPa m １／２ The range is preferred.

[0032] The fracture toughness value K of the second glass plate 12 in the laminated glass 10 according to this embodiment ＩＣ is 0.72 MPa m １／２ The fracture toughness value K of the second glass plate 12 is preferably equal to or greater than 100%. ＩＣ is 0.72 MPa m １／２ By satisfying the above, the strength against a collision from the fourth surface side can be increased. ＩＣ is 0.73 MPa m １／２ More preferably, 0.74 MPa m １／２More preferably, 0.75 MPa m １／２ The above is particularly preferable. ＩＣ is 1.0 MPa m from the viewpoint of pedestrian protection performance. １／２ Preferably, 0.97 MPa m or less １／２ More preferably, 0.95 MPa m １／２ More preferably, the fracture toughness value K of the second glass plate 12 is: ＩＣ is 0.72 to 1.0 MPa m １／２ The range is preferred.

[0033] The fracture toughness value K of the first glass sheet 11 and the second glass sheet 12 in the laminated glass 10 according to this embodiment ＩＣ In order to make it fall within the above range, for example, SiO ２ The method for adjusting the content of the alkali metal component is to adjust the proportion of the alkali metal component having a small atomic number, or to adjust the proportion of the alkali metal component having a small atomic number. ２ Since is a component that forms a network structure, increasing the content strengthens the glass structure, thereby improving fracture toughness. Furthermore, the smaller the atomic number of the alkaline earth metal component, the higher the Young's modulus, and as a result, the higher the fracture toughness. The smaller the atomic number of the alkali metal component, the same tendency as that of the alkaline earth metal component is observed.

[0034] Fracture toughness value K ＩＣ (MPa m １／２ ) is Young's modulus E (GPa), surface fracture energy γ (J / m ２ ) and Poisson's ratio ν (unitless) using the following formula:

[0035]

[0036] Furthermore, the fracture toughness values ​​K ＩＣis measured using a pre-crack introduction fracture test method (SEPB method: Single-Edge-Precracked-Beam method) based on JIS R1607:2015 "Fracture toughness test method for fine ceramics".

[0037] (Young's Modulus) The Young's modulus E of the first glass plate 11 in the laminated glass 10 according to this embodiment is preferably 60 GPa or more. When the Young's modulus E of the first glass plate 11 is 60 GPa or more, high resistance to stone chipping can be obtained. The Young's modulus E of the first glass plate 11 is more preferably 62 GPa or more, even more preferably 64 GPa or more, and particularly preferably 68 GPa or more. From the viewpoint of pedestrian protection performance, the Young's modulus E of the first glass plate 11 in the laminated glass 10 according to this embodiment is more preferably 100 GPa or less, even more preferably 95 GPa or less, and particularly preferably 90 GPa or less. That is, the Young's modulus E of the first glass plate 11 is preferably in the range of 60 to 100 GPa.

[0038] The Young's modulus E of the second glass plate 12 in the laminated glass 10 according to this embodiment is preferably 65 GPa or more. When the Young's modulus E of the second glass plate 12 is 65 GPa or more, high strength against a collision on the fourth main surface side can be obtained. The Young's modulus E of the second glass plate 12 is more preferably 66 GPa or more, even more preferably 67 GPa or more, and particularly preferably 70 GPa or more. From the viewpoint of pedestrian protection performance, the Young's modulus E of the second glass plate 12 in the laminated glass 10 according to this embodiment is more preferably 100 GPa or less, even more preferably 97 GPa or less, and particularly preferably 95 GPa or less. That is, the Young's modulus E of the second glass plate 12 is preferably in the range of 65 to 100 GPa.

[0039] In order to set the Young's modulus within the above range, the type and amount of alkaline earth metal and alkali metal are adjusted, and MgO and Li ２ Increase the O content, ２ O ３ , TiO ２ , ZrO ２ The Young's modulus can be measured by an ultrasonic pulse method based on JIS R1602:1995 "Testing method for elastic modulus of fine ceramics."

[0040] (Density) The density r of each of the first glass sheet 11 and the second glass sheet 12 in the laminated glass 10 according to this embodiment is 2.2 to 2.8 g / cm ３ The density r in the above range is preferable in terms of sound insulation, bending formability, and weight. The density r of the first glass sheet 11 and the second glass sheet 12 is 2.22 g / cm ３ More preferably, 2.25 g / cm ３ More preferably, 2.75 g / cm ３ More preferably, 2.7 g / cm or less ３ The following is even more preferred:

[0041] The density of the first glass sheet 11 and the second glass sheet 12 in the laminated glass 10 according to this embodiment is measured by Archimedes' method using a glass lump of about 20 g containing no bubbles cut out from the glass sheets.

[0042] (E / r) In the laminated glass 10 according to this embodiment, the value E / r obtained by dividing the Young's modulus E by the density r of each of the first glass sheet 11 and the second glass sheet 12 is preferably 25 to 40. When E / r is within the above range, the rigidity of the glass is increased, and sufficient rigidity is obtained. E / r of the first glass sheet 11 and the second glass sheet 12 is more preferably 26 or more, even more preferably 27 or more, and more preferably 38 or less, even more preferably 36 or less.

[0043] (Poisson's ratio) The Poisson's ratio of each of the first glass sheet 11 and the second glass sheet 12 in the laminated glass 10 according to this embodiment is preferably 0.18 to 0.27. A Poisson's ratio within the above range provides excellent bending formability and high rigidity. The Poisson's ratio of the first glass sheet 11 and the second glass sheet 12 is more preferably 0.185 or more, even more preferably 0.19 or more, and more preferably 0.265 or less, even more preferably 0.26 or less.

[0044] The Poisson's ratio of the first glass sheet 11 and the second glass sheet 12 in the laminated glass 10 according to this embodiment can be measured by an ultrasonic pulse method based on JIS R1602:1995 "Testing method for elastic modulus of fine ceramics."

[0045] (Glass transition temperature) The glass transition temperature Tg of the first glass sheet 11 in the laminated glass 10 according to this embodiment is preferably 700°C or lower. When the glass transition temperature Tg of the first glass sheet 11 is 700°C or lower, high bend formability can be obtained. The glass transition temperature Tg of the first glass sheet 11 is more preferably 690°C or lower, even more preferably 680°C or lower, and particularly preferably 670°C or lower. In terms of glass durability and bend formability, the glass transition temperature Tg of the first glass sheet 11 in the laminated glass 10 according to this embodiment is preferably 450°C or higher, more preferably 460°C or higher, and even more preferably 470°C or higher. That is, the glass transition temperature Tg of the first glass sheet 11 is preferably in the range of 450 to 700°C.

[0046] The glass transition temperature Tg of the second glass sheet 12 in the laminated glass 10 according to this embodiment is preferably 700°C or lower. When the glass transition temperature Tg of the second glass sheet 12 is 700°C or lower, high bend formability can be obtained. The glass transition temperature Tg of the second glass sheet 12 is more preferably 690°C or lower, even more preferably 680°C or lower, and particularly preferably 670°C or lower. From the viewpoint of bend formability, the glass transition temperature Tg of the second glass sheet 12 in the laminated glass 10 according to this embodiment is preferably 470°C or higher, more preferably 475°C or higher, and even more preferably 480°C or higher. That is, the glass transition temperature Tg of the second glass sheet 12 is preferably in the range of 470 to 700°C.

[0047] The glass transition temperature Tg can be measured using a differential thermal dilatometer (TMA) in accordance with JIS R3103-3:2001.

[0048] (Average Coefficient of Linear Expansion) The average coefficient of linear expansion (CTE) of the first glass sheet 11 and the second glass sheet 12 in the laminated glass 10 according to this embodiment at 50 to 350°C is 100 × 10 －７ / °C or less. The average linear expansion coefficient is preferably 100 x 10 －７ / °C or less, cracking due to heat shock can be suppressed when the laminated glass of this embodiment is used as a window glass for a vehicle. Furthermore, when the laminated glass of this embodiment is used as a curved glass, the difference in thermal expansion due to the difference in thermal history within the surface can be suppressed, and curved glass with good dimensional and surface accuracy can be obtained. －７ / °C or less, and 95 x 10 －７ / °C or less is more preferable, and 92 × 10 －７ / °C or less is more preferable, and 90 x 10 －７ / °C or less. From the viewpoint of suppressing cracking of the black ceramic due to the difference in thermal expansion between the black ceramic printed on the windshield and the black ceramic, the average linear expansion coefficient is preferably 30 x 10 －７ / °C or more. －７ / °C or more, the difference in thermal expansion with the black ceramic is small, and cracking of the black ceramic can be suppressed. －７ / °C or more is more preferable, and 37 x 10 －７ / °C or more is more preferable, and 38 x 10 －７ / °C or more, and 39 x 10 －７ / °C or more is particularly preferred, and 40 x 10 －７ / °C or more is particularly preferred, and 42 x 10 －７ / °C or more. That is, the average linear expansion coefficients of the first glass plate 11 and the second glass plate 12 are each preferably 30×10 －７ / ℃~100×10 －７ / °C range is preferred.

[0049] In order to set the average linear expansion coefficient within the above range, the SiO ２ Increase the content of R ２ O, RO and Al ２ O ３ The method for adjusting the content of

[0050] The average linear expansion coefficient can be measured using a differential thermal dilatometer (TMA) in accordance with JIS R3102:1995.

[0051] (Haze Value) The haze value of the laminated glass 10 according to this embodiment is preferably 3.0 or less. A haze value of 3.0 or less for the laminated glass 10 enables both visibility and strength to be achieved. The haze value of the laminated glass 10 is more preferably 2.8 or less, even more preferably 2.6 or less, and particularly preferably 2.5 or less. Furthermore, from the viewpoint of pedestrian protection performance, the haze value of the laminated glass 10 is more preferably 0.1 or more, even more preferably 0.3 or more, even more preferably 0.5 or more, and particularly preferably 1.0 or more. That is, the haze value of the laminated glass 10 is preferably in the range of 0.1 to 3.0.

[0052] The haze value of the laminated glass 10 according to this embodiment can be measured using a haze meter.

[0053] (Resistance to stone chipping) As shown in Fig. 2 , when a super steel indenter 20 weighing 1.0 g, having a tip angle of 120 degrees, and a tip curvature radius of 0.2 mm is collided perpendicularly with the surface of the laminated glass 10 facing the first glass sheet 11 (first main surface S1 of the first glass sheet 11 in Fig. 1 ) at a speed of 40 km / h, the laminated glass 10 preferably does not generate cracks originating from the second main surface S2 of the first glass sheet 11. Details of the method of the collision test will be described later in the examples.

[0054] (Penetration Resistance) The laminated glass 10 according to this embodiment preferably does not penetrate when a steel ball having a diameter of 82 mm and a weight of 260 g is dropped from a height of 4 m onto the center of a flat surface of a 300 mm x 300 mm laminated glass 10 placed on a horizontally supported frame with the second glass plate 12 side facing up, in an environment of room temperature 23±2°C and relative humidity 50±5%. In the above-mentioned ball drop test, the fact that the steel ball does not penetrate the laminated glass means that the laminated glass has impact resistance and can exhibit sufficient resistance to flying objects such as pebbles.

[0055] (Composition of First Glass Sheet and Second Glass Sheet) At least one of the first glass sheet and the second glass sheet in the laminated glass 10 according to this embodiment has a SiO content, expressed as mass % on an oxide basis, of 55≦SiO ２ ≦85 0≦Al ２ O３ ≦25 0≦B ２ O ３ ≦20 0≦MgO≦15 0≦CaO≦15 0≦SrO≦10 0≦BaO≦10 0≦ZnO≦10 0≦Li ２ O≦5 0≦Na ２ O≦20 0≦K ２ O≦10 0≦Fe ２ O ３ It is preferred that ≦1.

[0056] The composition ranges of each component in the first glass plate and the second glass plate (hereinafter simply referred to as the present glass plate) of this embodiment will be described below. The composition ranges of each component are expressed in mass % based on the oxide unless otherwise specified. Furthermore, when glass is "substantially free" of a component, it means that the component is not contained except for unavoidable impurities, and that the component is not actively added. Specifically, this means that the content of each of these components in the glass is approximately 100 ppm or less.

[0057] SiO in this glass plate ２ The content of SiO is preferably 55% or more and 85% or less. ２ contributes to improving the Young's modulus, making it easier to ensure the strength required for automobile applications, etc. ２ If the content of SiO is too low, it becomes difficult to ensure weather resistance, and the average linear expansion coefficient becomes too large, which may cause thermal cracking of the glass plate. ２ If the amount is too large, the viscosity of the glass increases when melted, which may make it difficult to manufacture the glass.

[0058] SiO in this glass plate ２ The content of SiO in the present glass plate is more preferably 57% or more, further preferably 59% or more, and particularly preferably 60% or more. ２ The content is more preferably 83% or less, further preferably 80% or less, and particularly preferably 78% or less.

[0059] Al in this glass plate ２ O ３ The content of Al is preferably 0% or more and 25% or less. ２ O３ contributes to suppressing phase separation of the glass and improving weather resistance. It also reduces the average linear expansion coefficient and makes the glass sheet less susceptible to thermal cracking. ２ O ３ When it contains Al ２ O ３ The content of Al in the glass plate is more preferably 1.0% or more, even more preferably 1.2% or more, even more preferably 1.3% or more, particularly preferably 1.4% or more, and most preferably 1.5% or more. ２ O ３ The content of １１ , T １２ From the viewpoint of keeping T low and facilitating the production of bent glass, it is more preferably 23% or less, further preferably 22% or less, particularly preferably 21% or less, and most preferably 20% or less. １１ is a glass viscosity of 10 １１ indicates the temperature in [dPa s], and T １２ is a glass viscosity of 10 １２ The temperature is shown in [dPa·s].

[0060] B in this glass plate ２ O ３ The content of is preferably 0% or more and 20% or less. ２ O ３ This glass plate contributes to improving the glass strength and meltability. ２ O ３ When it contains B ２ O ３ The content is more preferably 0.1% or more, further preferably 0.5% or more, particularly preferably 1% or more, and most preferably 2% or more.

[0061] On the other hand, B ２ O ３ If the content of B in the glass plate is too high, the alkali element is likely to volatilize during melting and forming, which may result in a deterioration in glass quality and a decrease in acid resistance and alkali resistance. ２ O ３ The content is more preferably 18% or less, further preferably 17% or less, particularly preferably 16% or less, and most preferably 15% or less.

[0062] In this glass plate, SiO ２ +Al ２ O ３ +B ２ O ３ , i.e., SiO ２ Content and Al ２ O ３ Content and B ２ O ３ The total content may be 70% or more and 97% or less. By setting it in the above range, the temperature T １１ , T １２ This makes it easier to manufacture bent glass. ２ +Al ２ O ３ +B ２ O ３ is more preferably 96% or less, and even more preferably 95% or less. ２ +Al ２ O ３ +B ２ O ３ If the amount is too small, the weather resistance may be reduced. ２ +Al ２ O ３ +B ２ O ３ is more preferably 71% or more, and even more preferably 72% or more.

[0063] The content of MgO in the present glass plate is preferably 0% or more and 15% or less. MgO is a component that promotes the melting of glass raw materials and improves weather resistance and Young's modulus. When the present glass plate contains MgO, the content of MgO is more preferably 0.5% or more, and even more preferably 1% or more. Furthermore, if the content of MgO in the present glass plate is 15% or less, devitrification is less likely to occur. The content of MgO in the present glass plate is more preferably 13% or less, even more preferably 12% or less, particularly preferably 11% or less, and most preferably 10% or less.

[0064] The CaO content in the present glass plate is preferably 0% or more and 15% or less. When the present glass plate contains CaO, the CaO content is more preferably 0.2% or more, and even more preferably 0.3% or more. This improves the meltability of glass raw materials and the formability of bent glass. Furthermore, by setting the CaO content in the present glass plate to 15% or less, an increase in the density of the glass is avoided, and low brittleness and strength are maintained. In order to prevent the glass from becoming brittle, the CaO content in the present glass plate is more preferably 13% or less, even more preferably 12% or less, particularly preferably 11% or less, and most preferably 10% or less.

[0065] The content of SrO in the present glass plate is preferably 0% or more and 10% or less. When SrO is contained, it is more preferably 0.1% or more, and even more preferably 0.3% or more. This improves the meltability of glass raw materials and the formability of bent glass. Furthermore, by setting the content of SrO in the present glass plate to 10% or less, an increase in the density of the glass is avoided, and low brittleness and strength are maintained. In order to prevent the glass from becoming brittle, the content of SrO in the present glass plate is more preferably 8% or less, even more preferably 6% or less, particularly preferably 5% or less, and most preferably substantially no SrO is contained.

[0066] The content of BaO in the present glass plate is preferably 0% or more and 10% or less. BaO is a component that improves the melting property of glass raw materials. When the present glass plate contains BaO, the content of BaO is more preferably 0.1% or more, and even more preferably 0.3% or more. Furthermore, by setting the content of BaO in the present glass plate to 10% or less, an increase in glass density and a decrease in glass strength due to low brittleness can be suppressed. The content of BaO in the present glass plate is more preferably 8% or less, even more preferably 6% or less, particularly preferably 4% or less, and most preferably substantially no BaO is contained.

[0067] The content of ZnO in the present glass plate is preferably 0% or more and 10% or less. ZnO is a component that improves the meltability and bendability of glass. When ZnO is contained, it is more preferably 0.1% or more, and even more preferably 0.3% or more. Furthermore, by making the ZnO content 10% or less, the strength characteristics of the glass can be improved. The content of ZnO is more preferably 8% or less, even more preferably 6% or less, particularly preferably 5% or less, and most preferably substantially not contained.

[0068] Li in this glass plate ２ The content of O is preferably 0% or more and 5% or less. ２ O is a component that improves the meltability of glass, and also makes it easier to increase the Young's modulus, thereby contributing to improving the strength of the glass. ２ By incorporating O, the viscosity of the glass is reduced, and therefore the formability of window glass for vehicles, particularly windshields, etc. is improved. ２ When O is contained, Li ２ The O content is more preferably 0.1% or more, further preferably 0.3% or more, particularly preferably 0.5% or more, and most preferably 1.0% or more. ２ If the content of O is too high, devitrification may occur during glass production, making production difficult. ２ The O content is more preferably 4.7% or less, further preferably 4.5% or less, particularly preferably 4.3% or less, and most preferably 4.2% or less.

[0069] Na in this glass plate ２ The content of O is preferably 0% or more and 20% or less. ２ O is a component that improves the melting property of glass. ２ By including O, the viscosity of the glass is reduced, and therefore the formability of the glass for vehicle window glass, particularly windshield, is improved. ２ When O is contained, Na ２ The O content is more preferably 0.5% or more, further preferably 1.0% or more, particularly preferably 2% or more, and most preferably 2.5% or more.２ If the amount of O is too large, the average linear expansion coefficient becomes too large, and the glass plate is prone to thermal cracking. ２ The O content is more preferably 18% or less, further preferably 17% or less, particularly preferably 16% or less, and most preferably 15% or less.

[0070] K in this glass plate ２ The content of O is preferably 0% or more and 10% or less. ２ O is a component that improves the melting property of glass. ２ When O is contained, K ２ The O content is more preferably 0.1% or more, even more preferably 0.3% or more, even more preferably 0.5% or more, particularly preferably 0.7% or more, and most preferably 1.0% or more. ２ If the content of O is too high, the average linear expansion coefficient becomes too large, and the glass plate is prone to thermal cracking. ２ The O content is more preferably 8% or less, further preferably 6% or less, and particularly preferably 5% or less.

[0071] Fe in this glass plate ２ O ３ The content of Fe is preferably 0% or more and 1% or less. ２ O ３ can be contained in order to impart heat insulating properties to the glass. ２ O ３ The content of FeO, which is an oxide of divalent iron, and Fe, which is an oxide of trivalent iron ２ O ３ This refers to the total amount of iron, including

[0072] The glass plate is Fe ２ O ３ When containing Fe ２ O ３ The content of is more preferably 0.005% or more, further preferably 0.007% or more, even more preferably 0.01% or more, particularly preferably 0.015% or more, and most preferably 0.02% or more. ２ O ３If the content of Fe in the glass plate is too high, the transmittance in the visible region may decrease. ２ O ３ The content is preferably 1% or less, more preferably 0.9% or less, and even more preferably 0.8% or less.

[0073] The glass plate is made of the above-mentioned SiO ２ , Al ２ O ３ , B ２ O ３ , MgO, CaO, SrO, BaO, ZnO, Li ２ O, Na ２ O.K. ２ O and Fe ２ O ３ It may contain other components (hereinafter also referred to as "other components"), and when other components are contained, the total content thereof is preferably 3% or less.

[0074] Other components include, for example, ZrO ２ , Y ２ O ３ , TiO ２ , CeO ２ , Nd ２ O ５ , GaO ２ , GeO ２ , MnO ２ , NiO, Cr ２ O ３ , V ２ O ５ , Er ２ O ３ , Au ２ O ３ , Ag ２ O, CuO, CdO, MoO ３ , S.O. ３ , Cl, F, SnO ２ , Sb ２ O ３ These may be metal ions or oxides. Other components may be contained for various purposes (for example, fining and coloring).

[0075] (β-OH value) In the first glass plate and the second glass plate in this embodiment, when moisture is present in the glass plate, the adhesion between the glass plate and the interlayer film is increased. １１ and T １２ This has the effect of reducing the β-OH value, which makes it easier to bend the glass sheet. Therefore, it is preferable that the first glass sheet and the second glass sheet in this embodiment contain a certain amount of moisture. The moisture content in the glass sheet can generally be expressed by a value called the β-OH value.

[0076] In this embodiment, at least one of the first glass plate and the second glass plate has a β-OH value of 0.050 mm －１ It is preferable that the thickness is 0.10 mm or more. －１ More preferably, it is 0.15 mm or more. －１ More preferably, it is 0.20 mm or more. －１ It is particularly preferable that the β-OH value of both the first glass sheet and the second glass sheet is 0.050 mm or more. －１ More preferably, both are 0.10 mm or more. －１ More preferably, it is equal to or greater than this.

[0077] On the other hand, if the amount of water in the glass sheet is too large, it may affect the network structure of the glass and reduce the resistance to chipping by stones. －１ Preferably, 0.60 mm or less －１ More preferably, 0.50 mm or less －１ More preferably, 0.40 mm or less －１ The following are particularly preferred:

[0078] β-OH can be obtained from the transmittance of glass measured using an FT-IR (Fourier transform infrared spectrophotometer) by the following formula: β-OH=(1 / X)log １０ (T Ａ / T Ｂ ) [mm －１ ] X: Sample thickness [mm] T Ａ :Reference wave number 4000cm －１ Transmittance [%] at T Ｂ : Hydroxyl group absorption wave number 3600 cm－１ Minimum transmittance in the vicinity [%]

[0079] (Glass Sheet Forming) In this embodiment, the first glass sheet and the second glass sheet are preferably float glass formed by, for example, a known float process. In the float process, a molten glass base is floated on a molten metal such as tin, and by strict temperature control, glass with a uniform thickness and sheet width can be formed, and glass with a large area can also be obtained.

[0080] Alternatively, the glass sheet may be formed by a known roll-out method or down-draw method, and may be a glass sheet having a polished surface and a uniform thickness. Here, the down-draw method is broadly divided into a slot down-draw method and an overflow down-draw method (fusion method), and both are techniques in which molten glass is continuously allowed to flow down from a forming body to form a band-shaped glass ribbon.

[0081] In this embodiment, the shapes of the first glass plate and the second glass plate are not particularly limited, but the area of ​​the main surface is preferably 250,000 mm ２ More than 450,000 mm is preferable. ２ More preferably, 900,000 mm or more ２ The above is even more preferable. When the area of ​​the glass sheet is within the above range, it can be used for various vehicle models. Furthermore, if the area of ​​the glass sheet is too large, the glass sheet becomes difficult to handle, the temperature distribution during heating becomes uneven, and the dimensional accuracy after bending becomes poor, which increases the difficulty of bending. Therefore, the area of ​​the main surface is set to 4,000,000 mm ２ Preferably, less than 3,500,000 mm ２ More preferably, 3,000,000 mm or less ２ The following is even more preferred:

[0082] The first glass sheet and the second glass sheet in this embodiment may be glass sheets that have been subjected to tempering treatment such as air-cooling tempering or chemical tempering. By performing the above treatment, the strength of the glass sheets can be increased.

[0083] Here, air-cooling tempering is a process for forming a compressive stress layer on the glass surface by thermal tempering. Specifically, a uniformly heated glass sheet is rapidly cooled from a temperature near its softening point, and compressive stress is formed on the glass surface due to the temperature difference between the glass surface and the glass interior. The compressive stress is generated uniformly over the entire glass surface, and a compressive stress layer of uniform depth is formed over the entire glass surface. Thermal tempering is more suitable for tempering thick glass sheets than chemical tempering.

[0084] Chemical strengthening is a process in which alkali metal ions with a small ionic radius (typically Li ions or Na ions) on the glass surface are replaced with alkali metal ions with a larger ionic radius (typically Na ions or K ions) by ion exchange at a temperature below the glass transition point, thereby forming a compressive stress layer on the glass surface. The chemical strengthening process can be carried out by a known method, such as ion exchange. The ion exchange process involves immersing a glass plate in a treatment solution (e.g., potassium nitrate molten salt) and exchanging ions with a small ionic radius (e.g., Na ions) contained in the glass for ions with a large ionic radius (e.g., K ions), thereby generating compressive stress on the glass surface. The magnitude of the compressive stress on the glass plate surface (hereinafter also referred to as surface compressive stress CS) and the depth DOL of the compressive stress layer formed on the glass plate surface can be adjusted by the glass composition, chemical strengthening treatment time, and chemical strengthening treatment temperature, respectively.

[0085] (Bent Glass) The first glass sheet and the second glass sheet in the present embodiment may be bent glass, which may be formed by shaping the flat first glass sheet or the flat second glass sheet into a curved shape by gravity forming, press forming, or the like.

[0086] Bent glass is glass that curves at a predetermined curvature, and may be single-curved glass that curves in only one direction, either up and down or left and right, or double-curved glass that curves in both up and down and left and right directions.

[0087] The minimum radius of curvature of the bent glass is preferably 500 mm or more and 100,000 mm or less. The radius of curvature of the bent glass is calculated by performing a shape simulation on a sample using a laser displacement meter (Dyvoce manufactured by Kohzu Seiki Co., Ltd.) based on the amount of warp inherent to the sample determined by weight deflection correction in a double-sided differential mode, and the radius of curvature is determined from the shape obtained by the simulation.

[0088] In the method for producing bent glass, the first glass sheet or the second glass sheet, each having a flat shape, is heated and bent to form bent glass. Examples of methods for forming bent glass include a method in which heated glass is placed on a forming mold and pressed from above with a press to bend the glass. Another example is a method in which flat glass is placed on a forming mold having a bending surface corresponding to the desired curved surface, and the forming mold is then carried into a heating furnace, where the glass is heated to a temperature close to the glass softening point. According to this forming method, the glass is softened and curved along the bending surface of the forming mold due to its own weight, resulting in glass having the desired curved surface.

[0089] In this embodiment, bending by the press means is preferred from the viewpoint of improving productivity and improving surface accuracy after forming. The bending method by the press means is not particularly limited, and for example, the method described in International Publication No. 2016 / 093031 can be appropriately adopted. Hereinafter, the bending method by the press means will be described as an example.

[0090] First, the flat first glass sheet and the flat second glass sheet are transported to a press area by a transport conveyor or the like. Then, in the press area, the flat first glass sheet and the flat second glass sheet are heated to a temperature at which they can be bent and softened. Here, the bendable temperature is, for example, a temperature at which the glass viscosity is 10 １１ [dPa s] Temperature T １１ The heating may be performed by a heater in a heating furnace during the process of transporting the material to the pressing area on a transport conveyor or the like. １１ The bending time under the condition of maintaining the above condition can be set to, for example, 1 second or more.

[0091] A lower press mold (female mold) and an upper press mold (male mold) are arranged at predetermined positions in the press area, and the upper surface shape of the female mold and the lower surface shape of the male mold correspond to the curved shapes of the first glass sheet and the second glass sheet to be bent in the conveying direction and the perpendicular direction. The female mold can be raised and lowered between a standby position below the conveyor and a press position above it, and after the glass is transferred from the conveyor, the female mold, with the glass sheet placed on it, is raised from a predetermined raised position to a press position above the conveyor, thereby press-forming the glass.

[0092] Next, the press-formed glass is transported to a cooling area by a transport shuttle, etc. In the cooling area, the glass is cooled by blowing cooled air onto it, etc.

[0093] The above steps result in the formation of a curved glass. While the above description has been given of bending the first glass sheet and the second glass sheet, the bending may also be performed on the laminated glass. When performing such bending, the first glass sheet is placed face down in a forming mold and subjected to processing.

[0094] (Interlayer film) The interlayer film 13 according to this embodiment is sandwiched between the first glass sheet 11 and the second glass sheet 12. By including the interlayer film 13, the laminated glass 10 according to this embodiment can firmly bond the first glass sheet 11 and the second glass sheet 12 together and can also absorb the impact force when flying debris hits the glass sheets.

[0095] Various organic resins that are commonly used in conventional laminated glass can be used for the interlayer film 13. Examples of organic resins include polyethylene (PE), ethylene vinyl acetate copolymer (EVA), polypropylene (PP), polystyrene (PS), methacrylic resin (PMA), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), cellulose acetate (CA), diallyl phthalate resin (DAP), urea resin (UP), melamine resin (MF), unsaturated polyester (UP), polyvinyl butyral (PVB), and polyvinyl hol. Examples of materials that can be used include marl (PVF), polyvinyl alcohol (PVAL), vinyl acetate resin (PVAc), ionomer (IO), polymethylpentene (TPX), vinylidene chloride (PVDC), polysulfone (PSF), polyvinylidene fluoride (PVDF), methacrylic-styrene copolymer resin (MS), polyarate (PAR), polyallylsulfone (PASF), polybutadiene (BR), polyethersulfone (PESF), and polyetheretherketone (PEEK). Among these, EVA and PVB are preferred from the viewpoints of transparency and adhesion, and PVB is particularly preferred because it can impart sound insulation properties.

[0096] From the viewpoints of impact force absorption and sound insulation, the thickness of the interlayer film 13 is preferably 0.300 mm or more, more preferably 0.500 mm or more, and even more preferably 0.700 mm or more. Furthermore, from the viewpoint of suppressing a decrease in visible light transmittance, the thickness of the interlayer film 13 is preferably 1.00 mm or less, more preferably 0.900 mm or less, and even more preferably 0.800 mm or less. Furthermore, the thickness of the interlayer film 13 is preferably in the range of 0.300 mm to 1.00 mm, more preferably 0.700 mm to 0.800 mm. The thickness of the interlayer film 13 may be uniform across the entire surface or may vary from location to location as necessary. Note that the thickness of the interlayer film in this specification refers to the thickness calculated by measuring the average thickness of the laminated glass 10 using a constant-pressure thickness gauge and subtracting the average thickness of the first glass sheet 11 and the average thickness of the second glass sheet 12 from the average thickness of the laminated glass 10.

[0097] If the difference in linear expansion coefficient between the interlayer film 13 and the first glass sheet 11 or the second glass sheet 12 is large, cracks or warping may occur in the laminated glass 10 when the laminated glass 10 is produced through the heating step described below, which may result in poor appearance. Therefore, it is preferable that the difference in linear expansion coefficient between the interlayer film 13 and the first glass sheet 11 or the second glass sheet 12 is as small as possible. The difference in linear expansion coefficient between the interlayer film 13 and the first glass sheet 11 or the second glass sheet 12 may be expressed as the difference between the average linear expansion coefficients in a predetermined temperature range.

[0098] In particular, since the resin constituting the interlayer film 13 has a low glass transition point, a predetermined difference in the average linear expansion coefficient may be set within a temperature range equal to or lower than the glass transition point of the resin material. The difference in the linear expansion coefficient between the first glass sheet 11 or the second glass sheet 12 and the resin material may be set at a predetermined temperature equal to or lower than the glass transition point of the resin material.

[0099] Alternatively, an adhesive layer containing an adhesive may be used as the interlayer film 13. The adhesive is not particularly limited, but an acrylic adhesive, a silicone adhesive, or the like may be used. When the interlayer film 13 is an adhesive layer, a heating step is not required in the process of joining the first glass plate 11 and the second glass plate 12, and therefore the risk of the above-mentioned cracking or warping occurring is reduced.

[0100] (Total Thickness) In the laminated glass 10 of this embodiment, the total thickness of the first glass sheet 11, the second glass sheet 12, and the interlayer film 13 is preferably 2.80 mm or more. A total thickness of 2.80 mm or more ensures sufficient strength. The total thickness is more preferably 3.00 mm or more, even more preferably 3.50 mm or more, even more preferably 4.00 mm or more, particularly preferably 4.50 mm or more, and most preferably 4.70 mm or more. From the viewpoint of weight reduction, the total thickness may be 6.00 mm or less, preferably 5.80 mm or less, more preferably 5.60 mm or less, and even more preferably 5.40 mm or less.

[0101] (Other Layers) The laminated glass 10 of the present embodiment may include layers (hereinafter also referred to as "other layers") other than the first glass sheet 11, the second glass sheet 12, and the interlayer film 13, provided that the effects of the present invention are not impaired. For example, the laminated glass 10 may include a coating layer that imparts water-repellent properties, hydrophilic properties, anti-fogging properties, or the like, an infrared reflective film, or the like.

[0102] The positions at which the other layers are provided are not particularly limited, and the other layers may be provided on the surface of the laminated glass 10, or may be sandwiched between the first glass sheet 11, the second glass sheet 12, or the interlayer film 13. The laminated glass 10 of this embodiment may also include a black ceramic layer or the like arranged in a strip shape along part or all of the peripheral edge for the purpose of concealing the attachment portion to the frame or the wiring conductors.

[0103] (Method for manufacturing laminated glass) The method for manufacturing laminated glass 10 of the present embodiment includes a step of stacking a first glass plate 11, an interlayer film 13, and a second glass plate 12 in this order, and then heating and pressurizing the laminated glass 10, in which the first glass plate 11 and the second glass plate 12 are joined together via the interlayer film 13.

[0104] The manufacturing method of laminated glass 10 of this embodiment includes abrading the second main surface S2 of a first glass plate 11, which has a first main surface S1 and a second main surface S2 opposing the first main surface S1, by any one of wet blasting, sandblasting, and sandpaper, and laminating the first glass plate 11, an interlayer film 13, and a second glass plate 12, which has a third main surface S3 and a fourth main surface S4 opposing the third main surface S3, in this order, so that the second main surface S2 of the first glass plate 11 faces the third main surface S3 of the second glass plate 12. By abrading the second main surface S2 of the first glass plate 11, which is the side opposing the second glass plate 12, the developed area ratio Sdr2 of the second main surface S2 is set to a range of 0.001 to 2.5. This makes it difficult for the first glass plate 11 to peel off from the interlayer film 13, suppressing deterioration of optical properties, and improving impact resistance when the laminated glass is used in an automobile with the first glass plate 11 on the outside of the automobile, for example.

[0105] The scratching of the second main surface S2 of the first glass plate 11 is carried out so that the developed area ratio Sdr2 is 0.001 to 2.5 in at least 30% of a region 200 mm from the edge of the second main surface S2 of the first glass plate 11. The scratching of the second main surface S2 is carried out so that the developed area ratio Sdr2 is preferably 0.002 or more, more preferably 0.003 or more, even more preferably 0.005 or more, and particularly preferably 0.007 or more. The scratching of the second main surface S2 is carried out so that the developed area ratio Sdr2 is preferably 2.0 or less, more preferably 1.8 or less, and even more preferably 1.5 or less.

[0106] In the method for manufacturing laminated glass of this embodiment, it is preferable to scratch the third main surface S3 of the second glass sheet 12, which faces the first glass sheet 11, using any one of wet blasting, sandblasting, and sandpaper. By scratching the third main surface S3, it is preferable to set the developed area ratio Sdr3 of the third main surface S3 in the range of 0.001 to 2.5. This makes the second glass sheet 12 less likely to peel from the interlayer film 13, suppressing deterioration of the optical properties, and further improving impact resistance when the laminated glass is used in an automobile with the first glass sheet 11 facing the exterior of the automobile, for example.

[0107] The scratching of the third main surface S3 of the second glass plate 12 may be carried out so that the developed area ratio Sdr3 is in the range of 0.001 to 2.5 in at least 30% of a region 200 mm from the edge of the third main surface S3 of the second glass plate 12. The scratching of the third main surface S3 is more preferably carried out so that the developed area ratio Sdr3 is 0.002 or more, and even more preferably 0.003 or more. Furthermore, the scratching of the third main surface S3 is more preferably carried out so that the developed area ratio Sdr3 is 1.4 or less, and even more preferably 1.2 or less.

[0108] The method for manufacturing the laminated glass 10 according to this embodiment may, for example, include a step of heating and shaping the first glass sheet 11 and the second glass sheet 12, followed by a step of inserting the interlayer film 13 between the first glass sheet 11 and the second glass sheet 12 and applying heat and pressure. By going through these steps, the laminated glass 10 may be configured such that the first glass sheet 11 and the second glass sheet 12 are joined together via the interlayer film 13.

[0109] (Vehicle window glass) The laminated glass 10 of this embodiment is suitably used as a vehicle window glass. Hereinafter, an example of using the laminated glass 10 of this embodiment as a vehicle window glass will be described with reference to the drawings. FIG. 3 is a conceptual diagram showing a state in which the laminated glass 10 of this embodiment is attached to an opening 110 formed in the front of an automobile 100 and used as a window glass of the automobile. The laminated glass 10 used as a window glass of an automobile may have a housing (case) 120 attached to its surface on the interior side of the vehicle, the housing 120 housing an information device or the like to ensure the driving safety of the vehicle.

[0110] The information device housed in the housing is a device that uses a camera, radar, etc. to prevent rear-end collisions with vehicles ahead, pedestrians, obstacles, etc., and to alert the driver to danger. For example, it is an information receiving device and / or information transmitting device, etc., and includes millimeter-wave radar, stereo cameras, infrared lasers, etc., which send and receive signals. The "signal" refers to electromagnetic waves including millimeter waves, visible light, infrared light, etc.

[0111] 4 is an enlarged partial perspective view of the S portion of the automobile in FIG. 3 , showing the portion where the housing 120 is attached to the laminated glass 10 of this embodiment. The housing 120 houses a millimeter-wave radar 201 and a stereo camera 202 as information devices. The housing 120 housing the information devices is usually attached on the outer side of the vehicle relative to the rearview mirror 150 and on the inner side of the vehicle relative to the laminated glass 10, but may also be attached to other portions.

[0112] 5 is a cross-sectional view taken along line Y-Y in FIG. 4 and perpendicular to the horizontal line. It is preferable that the first glass sheet 11 of the laminated glass 10 be disposed on the vehicle exterior side. This configuration allows for the realization of a lightweight, gray-colored windshield with a highly stylish design that is highly resistant to stone chipping and rigid.

[0113] The present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the above-described embodiments, and modifications and improvements can be made as appropriate. In addition, the material, shape, size, number, and location of each component in the above-described embodiments are arbitrary and not limited as long as the present invention can be achieved.

[0114] As described above, this specification discloses the following. [1] Laminated glass including a first glass plate having a first main surface and a second main surface opposite the first main surface, a second glass plate having a third main surface and a fourth main surface opposite the third main surface, and an interlayer sandwiched between the second main surface of the first glass plate and the third main surface of the second glass plate, wherein the developed area ratio Sdr2 of the second main surface is in the range of 0.001 to 2.5. [2] The laminated glass according to [1] above, wherein the developed area ratio Sdr3 of the third main surface is in the range of 0.001 to 2.5. [3] The laminated glass according to [1] or [2] above, wherein the developed area ratio Sdr2 of the second main surface is in the range of 0.001 to 2.0. [4] The laminated glass according to [2] or [3] above, wherein the developed area ratio Sdr3 of the third main surface is in the range of 0.001 to 1.5. [5] β-OH of at least one of the first glass plate and the second glass plate is 0.10 mm －１ [6] The laminated glass according to any one of [1] to [4], wherein the β-OH of both the first glass sheet and the second glass sheet is 0.10 mm or more. －１[7] The laminated glass according to any one of [1] to [6], having a haze value of 3.0 or less. [8] The laminated glass according to any one of [1] to [7], wherein a steel ball having a diameter of 82 mm and a weight of 260 g is allowed to fall freely from a height of 4 m onto the center of a flat surface of a 300 mm x 300 mm laminated glass placed on a horizontally supported frame with the second glass sheet side facing up, under an environment of room temperature of 23±2°C and a relative humidity of 50±5%, the steel ball does not penetrate the laminated glass. [9] The laminated glass according to any one of [1] to [8], wherein a 1.0 g cemented carbide indenter having a tip angle of 120 degrees and a tip curvature radius of 0.2 mm is allowed to collide perpendicularly with the surface of the laminated glass facing the first glass sheet at a speed of 40 km / h, and wherein no cracks are generated originating from the second main surface of the first glass sheet.

[10] The laminated glass according to any one of [1] to [9], wherein, when the edge of the laminated glass is processed into a C-chamfered shape (C0.1, angle 45°) using a #230 electroplated grindstone at a grindstone rotation speed of 10,000 rpm and a feed rate of 200 mm / min, the average size of chipping that occurs at the boundary between the first or second main surface and the edge is 40 μm or less.

[11] The laminated glass according to any one of [1] to

[10] , wherein, when the edge of the laminated glass is processed into a C-chamfered shape (C0.1, angle 45°) using a #230 electroplated grindstone at a grindstone rotation speed of 10,000 rpm and a feed rate of 200 mm / min, the average size of chipping that occurs at the boundary between the third or fourth main surface and the edge is 40 μm or less.

[12] The laminated glass according to any one of [1] to

[11] above, wherein the thickness of the first glass sheet is 2.0 to 5.0 mm and the thickness of the second glass sheet is 0.5 to 2.5 mm.

[13] The laminated glass according to any one of [1] to

[12] above, wherein the thickness of the first glass sheet and the thickness of the second glass sheet are the same or greater than the thickness of the second glass sheet.

[14] The fracture toughness value K of the first glass sheet ＩＣ is 0.7 MPa m １／２

[15] The laminated glass according to any one of [1] to

[14] , wherein the Young's modulus of the first glass sheet is 60 GPa or more.

[16] The density of the first glass sheet and the second glass sheet is 2.2 to 2.8 g / cm ３

[17] The laminated glass according to any one of [1] to

[16] above, wherein the Poisson's ratio of the first glass sheet and the second glass sheet is 0.18 to 0.27.

[18] The laminated glass according to any one of [1] to

[17] above, wherein the glass transition temperature of the first glass sheet is 700°C or lower.

[19] At least one of the first glass sheet and the second glass sheet has a SiO content, expressed in mass% on an oxide basis, of 55≦SiO ２ ≦85 0≦Al ２ O ３ ≦25 0≦B ２ O ３ ≦20 0≦MgO≦15 0≦CaO≦15 0≦SrO≦10 0≦BaO≦10 0≦ZnO≦10 0≦Li ２ O≦5 0≦Na ２ O≦20 0≦K ２ O≦10 0≦Fe ２ O ３

[20] The laminated glass according to any one of [1] to

[19] , comprising: abrading the second main surface of a first glass plate, the first glass plate having a first main surface and a second main surface opposite the first main surface, by any one of wet blasting, sandblasting, and sandpaper; and laminating the first glass plate, an interlayer film, and a second glass plate having a third main surface and a fourth main surface opposite the third main surface, in this order, so that the second main surface of the first glass plate faces the third main surface of the second glass plate.

[21] The laminated glass according to

[20] , comprising abrading the third main surface of the second glass plate by any one of wet blasting, sandblasting, and sandpaper before laminating the first glass plate, the interlayer film, and the second glass plate.

[0115] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

[0116] <Preparation of Laminated Glass> Laminated glasses of Examples 1 to 13 were produced according to the following procedure. Examples 1 to 11 are working examples, and Examples 12 and 13 are comparative examples. (Example 1) [First Glass Sheet] Raw materials were placed in a platinum crucible and melted at 1650°C for 3 hours to obtain molten glass, so as to achieve the glass composition (unit: mass%) shown in Glass 1 in Table 1. The molten glass was poured onto a carbon plate and slowly cooled. Both sides of the obtained glass sheet were polished to obtain a plate-shaped first glass sheet measuring 30 cm x 30 cm x 2.6 mm thick, having a first main surface and a second main surface opposite the first main surface. The entire area of ​​the second main surface of the first glass sheet was scratched by wet blasting. [Second Glass Sheet] Raw materials were placed in a platinum crucible and melted at 1650°C for 3 hours to obtain the glass composition (unit: mass%) shown in Glass 1 in Table 1. The molten glass was poured onto a carbon plate and slowly cooled. Both sides of the obtained plate-shaped glass were polished to obtain a plate-shaped second glass plate having a third main surface and a fourth main surface opposite the third main surface, measuring 30 cm x 30 cm x 1.3 mm in thickness. The entire area of ​​the third main surface of the second glass plate was scratched by wet blasting. [Interlayer film] A polyvinyl butyral film with a thickness of 0.76 mm was used as the interlayer film. [Laminated glass] The first glass plate, the interlayer film, and the second glass plate were laminated in this order so that the second main surface of the first glass plate faced the third main surface of the second glass plate, and pressure bonding was performed using an autoclave (1 MPa, 130°C, 3 hours) to produce the laminated glass of Example 1.

[0117] (Examples 2 to 12) Laminated glasses of Examples 2 to 12 were produced in the same manner as in Example 1, except that the types and thicknesses of the first glass plate and the second glass plate were changed as shown in Tables 1 and 2.

[0118] (Example 13) The types and thicknesses of the first glass plate and the second glass plate were changed as shown in Tables 1 and 2, and a laminated glass of Example 13 was produced in the same manner as in Example 1. However, in Example 13, no scratches were made to the first glass plate and the second glass plate.

[0119] The methods for determining the values ​​shown in Tables 1 and 2 are as follows: (1) Glass Transition Temperature Tg The glass transition temperature Tg was measured using a differential thermal dilatometer (TMA) in accordance with JIS R3103-3:2001.

[0120] (2) Average coefficient of linear expansion from 50°C to 350°C (CTE_50-350°C) The average coefficient of linear expansion from 50°C to 350°C was measured using a differential thermal dilatometer (TMA) in accordance with JIS R3102:1995.

[0121] (3) Density r The density r was measured by Archimedes' method using a glass block of about 20 g containing no bubbles cut out from a glass plate.

[0122] (4) Young's modulus E, modulus of rigidity G, and Poisson's ratio v Young's modulus E, modulus of rigidity G, and Poisson's ratio v were measured at 25°C by an ultrasonic pulse method (Olympus, DL35) based on JIS R1602:1995 "Testing method for elastic modulus of fine ceramics."

[0123] (5) E / r E / r is expressed as an integer by rounding off the value obtained by dividing Young's modulus E by density r using the Young's modulus E and density r measured by the above method.

[0124] (6) Fracture toughness value K ＩＣ Based on JIS R1607:2015 "Fracture toughness test method for fine ceramics", the measurement was performed using a pre-crack introduction fracture test method (SEPB method: Single-Edge-Precracked-Beam method).

[0125] (7) Average chipping size The average chipping size on the edge of the first glass plate was measured using a #230 electroplated grinding wheel at a grinding wheel rotation speed of 10,000 rpm and a feed rate of 200 mm / min to form a C-chamfered shape (C0.1, angle 45 °) on the edge of the laminated glass of each example. The size of the chipping occurring at the boundary between the first main surface S1 or the second main surface S2 and the edge was measured with a digital microscope, and the average value was calculated. The average chipping size on the edge of the second glass plate was measured using a #230 electroplated grinding wheel at a grinding wheel rotation speed of 10,000 rpm and a feed rate of 200 mm / min to form a C-chamfered shape (C0.1, angle 45 °) on the edge of the laminated glass of each example. The size of the chipping occurring at the boundary between the third main surface S3 or the fourth main surface S4 and the edge was measured with a digital microscope, and the average value was calculated.

[0126] (8) Haze Value Measurement was carried out using a haze meter (HZ-V3).

[0127] (9) Developed Area Ratio Sdr This was measured using a laser microscope (VK-X260) with an objective lens of 150x magnification in high definition mode.

[0128] (10) β-OH Raw materials were placed in a platinum crucible and melted at 1650°C for 3 hours to obtain the glass composition (unit: mass%) shown in Table 1, to obtain molten glass, which was then poured onto a carbon plate and slowly cooled. Both sides of the obtained plate-shaped glass were polished to prepare a glass sample with a thickness of 2.0 mm. The transmittance of the glass sample was measured using an FT-IR (Fourier transform infrared spectrophotometer), and β-OH was calculated as follows: β-OH = (1 / X) log １０ (T Ａ / T Ｂ ) [mm －１ ] X: Sample thickness [mm] T Ａ :Reference wave number 4000cm －１ Transmittance [%] at T Ｂ : Hydroxyl group absorption wave number 3600 cm －１ Minimum transmittance in the vicinity [%]

[0129] (11) Drop Ball Test The test was conducted in accordance with the penetration resistance test of JIS R3212:2015. A 300 mm x 300 mm laminated glass was placed on a horizontally supported frame with the second glass sheet (inner sheet) of the laminated glass facing up, and a steel ball with a diameter of 82 mm and a weight of 2260 g was dropped freely from a height of 4 m onto the center of the flat surface of the laminated glass. The test was conducted in an environment of room temperature of 23°C ± 2°C and relative humidity of 50 ± 5%. Evaluation A was a pass, and evaluation B was a fail. A: The steel ball did not penetrate the laminated glass. B: The steel ball penetrated the laminated glass.

[0130] (12) Evaluation of stone chipping resistance Stone chipping resistance was evaluated by the following method. A 1.0 g ultra-steel indenter with a weight of 1.0 g, a tip angle of 120 degrees, and a tip curvature radius of 0.2 mm was collided perpendicularly with the surface of the first glass sheet (outer sheet) of the laminated glass at a speed of 40 km / h, and the presence or absence of cracks originating from the second main surface of the first glass sheet was determined. Evaluation A was a pass, and evaluation B was a fail. A: No cracks originating from the second main surface were generated. B: Cracks originating from the second main surface were generated.

[0131] The results are shown in Tables 1 and 2.

[0132]

[0133]

[0134] The laminated glasses of Examples 1 to 11 had an expanded area ratio of the second main surface of the first glass plate in the range of 0.001 to 2.5, and exhibited good adhesion between the first glass plate and the interlayer film, and were excellent in both the ball drop test and stone chipping resistance. On the other hand, the laminated glass of Example 12 had an excessively large expanded area ratio of the second main surface of the first glass plate, resulting in poor stone chipping resistance. Furthermore, the laminated glass of Example 13 had an excessively small expanded area ratio of the second main surface of the first glass plate, resulting in poor impact resistance.

[0135] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made thereto without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2024-155114) filed on September 9, 2024, the contents of which are incorporated herein by reference.

[0136] REFERENCE SIGNS LIST 10 laminated glass 11 first glass sheet 12 second glass sheet 13 interlayer 20 indenter 100 automobile 110 opening 120 housing 150 rearview mirror 201 millimeter wave radar 202 stereo camera 300 radio waves S1 first principal surface S2 second principal surface S3 third principal surface S4 fourth principal surface

Claims

1. Laminated glass comprising: a first glass plate having a first principal surface and a second principal surface opposite the first principal surface; a second glass plate having a third principal surface and a fourth principal surface opposite the third principal surface; and an interlayer sandwiched between the second principal surface of the first glass plate and the third principal surface of the second glass plate, wherein the developed area ratio Sdr2 of the second principal surface is in the range of 0.001 to 2.

5.

2. The laminated glass according to claim 1, wherein the developed area ratio Sdr3 of the third principal surface is in the range of 0.001 to 2.

5.

3. The laminated glass according to claim 1 or 2, wherein the developed area ratio Sdr2 of the second main surface is in the range of 0.001 to 2.

0.

4. The laminated glass according to claim 2, wherein the developed area ratio Sdr3 of the third principal surface is in the range of 0.001 to 1.

5.

5. The β-OH of at least one of the first glass plate and the second glass plate is 0.10 mm －１ The laminated glass according to claim 1 or 2, wherein 6. The β-OH of both the first glass plate and the second glass plate is 0.10 mm －１ The laminated glass according to claim 5 .

7. The laminated glass according to claim 1 or 2, which has a haze value of 3.0 or less.

8. The laminated glass according to claim 1 or 2, wherein a steel ball having a diameter of 82 mm and a weight of 260 g is allowed to fall freely from a height of 4 m onto the center of a flat surface of a 300 mm x 300 mm laminated glass placed on a horizontally supported frame with the second glass plate side facing up, in an environment of room temperature of 23±2°C and relative humidity of 50±5%, and the steel ball does not penetrate the laminated glass.

9. The laminated glass according to claim 1 or 2, in which, when a super steel indenter weighing 1.0 g, having a tip angle of 120 degrees and a tip curvature radius of 0.2 mm is collided perpendicularly with the surface of the laminated glass facing the first glass plate at a speed of 40 km / h, no cracks are generated originating from the second main surface of the first glass plate.

10. The laminated glass according to claim 1 or 2, wherein, when the edge of the laminated glass is processed into a C-chamfered shape (C0.1, angle 45°) using a #230 electroplated grinding wheel at a grinding wheel rotation speed of 10,000 rpm and a feed rate of 200 mm / min, the average size of chipping generated at the boundary between the first main surface or second main surface and the edge is 40 μm or less.

11. The laminated glass according to claim 1 or 2, wherein, when the edge of the laminated glass is processed into a C-chamfered shape (C0.1, angle 45°) using a #230 electroplated grinding wheel at a grinding wheel rotation speed of 10,000 rpm and a feed rate of 200 mm / min, the average size of chipping generated at the boundary between the third principal surface or the fourth principal surface and the edge is 40 μm or less.

12. The laminated glass according to claim 1 or 2, wherein the first glass sheet has a thickness of 2.0 to 5.0 mm, and the second glass sheet has a thickness of 0.5 to 2.5 mm.

13. The laminated glass according to claim 1 or 2, wherein the thickness of the first glass sheet and the thickness of the second glass sheet are the same or the thickness of the first glass sheet is greater than the thickness of the second glass sheet.

14. Fracture toughness value K of the first glass plate ＩＣ is 0.7 MPa m １／２ The laminated glass according to claim 1 or 2, wherein 15. The laminated glass according to claim 1 or 2, wherein the first glass sheet has a Young's modulus of 60 GPa or more.

16. The density of the first glass plate and the second glass plate is 2.2 to 2.8 g / cm ３ The laminated glass according to claim 1 or 2, 17. The laminated glass according to claim 1 or 2, wherein the Poisson's ratio of the first glass sheet and the second glass sheet is 0.18 to 0.

27.

18. The laminated glass according to claim 1 or 2, wherein the glass transition temperature of the first glass sheet is 700°C or lower.

19. At least one of the first glass sheet and the second glass sheet has, in mass % on an oxide basis, 55≦SiO ２ ≦85 0≦Al ２ O ３ ≦25 0≦B ２ O ３ ≦20 0≦MgO≦15 0≦CaO≦15 0≦SrO≦10 0≦BaO≦10 0≦ZnO≦10 0≦Li ２ O≦5 0≦Na ２ O≦20 0≦K ２ O≦10 0≦Fe ２ O ３ 3. The laminated glass of claim 1 or 2, wherein the saturation temperature is 100° C. or less.

20. A method for manufacturing laminated glass as defined in claim 1 or 2, comprising: abrading the second main surface of a first glass plate having a first main surface and a second main surface opposite the first main surface using one of wet blasting, sandblasting, and sandpaper; and laminating the first glass plate, an interlayer film, and a second glass plate having a third main surface and a fourth main surface opposite the third main surface in this order, with the second main surface of the first glass plate facing the third main surface of the second glass plate.

21. The method for producing laminated glass according to claim 20, further comprising, before laminating the first glass sheet, the interlayer film, and the second glass sheet, abrading the third main surface of the second glass sheet by any one of wet blasting, sandblasting, and sandpaper.

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