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

Abstract

The present application provides a vehicle laminated glass, wherein the proportion of the region where the breaking stress determined by the method described in ISO 1288-5 (2016) is 100 MPa or more and 600 MPa or less is 90% or more of the perspective region.

Description

Technical Field

[0001] This invention relates to laminated glass for vehicles, automobiles, and a method for manufacturing laminated glass for vehicles. Background Technology

[0002] Automobiles and other vehicles require high safety standards. For example, windshields, from the perspective of protecting passengers as safety glass for vehicles, must meet standards that prevent passengers from being ejected from the vehicle upon impact and absorb the impact. Furthermore, in recent years, safety performance in collisions with pedestrians has received increasing attention. Especially in the event of a vehicle colliding with a human body, there is a strong demand for performance that ensures human safety, i.e., human protection performance during a collision, and various solutions are currently being researched. For example, Patent Document 1 proposes a solution where, when a vehicle impacts a pedestrian forward, applying a downward impact to the front vent cover and the area around the windshield, the pedestrian's safety can be ensured by separating the interconnected front vent cover and windshield.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-213928 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] As mentioned above, the high safety requirements are placing increasing demands on vehicle glass. Vehicle glass requires a certain degree of robustness as a whole; furthermore, considering the protection of the human body during collisions, it is also necessary to control the strength of vehicle glass so that it does not easily cause impact or injury to the human body when colliding with it.

[0008] However, it is known that glass, when formed into a sheet, originally has a strength distribution within its surface, and the strength of the glass sheet is usually randomly specified based on factors such as safety factor and probability of breakage. Therefore, even if the overall strength of vehicle glass is appropriate, there will be localized areas of excessive strength within the surface of the vehicle glass. If such an area of ​​excessive strength collides with a person, it may still cause injury.

[0009] Here, in order to reduce the strength in areas of excessive strength that exist locally within the plane, it is also considered to change the composition or manufacturing method of the glass to reduce the overall strength of the vehicle glass. However, in this case, strength reduction will also occur in areas of lower strength within the plane, which may compromise the robustness necessary for the vehicle glass. Therefore, there is a need for a type of vehicle glass that ensures robustness as a vehicle glass by reducing or eliminating areas of excessive strength to suppress the distribution of strength within the plane, while also providing high safety performance during a collision from the aforementioned perspective of human safety.

[0010] The technical problem to be solved by one aspect of the present invention is to provide vehicle glass that is both robust and has high safety performance in the event of a collision.

[0011] Technical solutions adopted to solve technical problems

[0012] One aspect of the present invention is a laminated glass for vehicles, wherein the proportion of the region in which the breaking stress, as measured by the method described in ISO 1288-5 (2016), is 100 MPa or more and 600 MPa or less, is 90% or more of the transparent region.

[0013] Invention Effects

[0014] According to one aspect of the present invention, it is possible to provide vehicle glass that is both robust and has high safety performance in the event of a collision. Attached Figure Description

[0015] Figure 1 This is a front view of a vehicle equipped with laminated glass according to an embodiment of the present invention.

[0016] Figure 2 yes Figure 1 The cross-sectional view of the laminated glass shown.

[0017] Figure 3 This is a graph showing the results of Examples 1 and 2.

[0018] Figure 4 This is a diagram showing the positions of the samples cut from the front window glass in Examples 3 and 4.

[0019] Figure 5 This is a graph showing the results of Examples 3 and 4. Detailed Implementation

[0020] <Vehicle Glass>

[0021] One aspect of the present invention is glass for vehicles, specifically laminated glass for vehicles. Figure 1 The image shows an example of the vehicle laminated glass 1 of this type being used as a window glass of a car 100. Figure 1In the example, the vehicle laminated glass 1 is the windshield of the car 100, but the vehicle laminated glass 1 can also be used as a window glass other than the windshield, such as the side window glass, the rear window glass, or the sunroof glass.

[0022] Figure 2 Show Figure 1 The image shows a cross-sectional view of the laminated glass 1 used in the vehicle. (See image.) Figure 2 As shown, the laminated glass 1 for vehicles is a laminated glass formed by bonding a first glass plate 10 and a second glass plate 20 together with an interlayer film 30. Figure 2 In the example, the first glass panel 10 is disposed on the outer side of the vehicle, and the second glass panel 20 is disposed on the inner side of the vehicle. Additionally, as... Figure 2 As shown, the first glass panel 10 on the outer side of the vehicle has a first surface 11 as the outer side of the vehicle and a second surface 12 as the inner side of the vehicle, and the second glass panel 20 on the inner side of the vehicle has a third surface 21 as the outer side of the vehicle and a fourth surface 22 as the inner side of the vehicle.

[0023] The materials constituting the first glass plate 10 and the second glass plate 20 (hereinafter, sometimes collectively referred to as glass plates) are preferably inorganic glass. Examples of inorganic glass include soda-lime silicate glass, aluminosilicate glass, borosilicate glass, lithium aluminum silicate glass, and borosilicate glass. There are no particular limitations on the forming method of the glass plate formed from inorganic glass, but it is preferable, for example, that the glass plate is formed by the float glass process or the like.

[0024] Unstrengthened glass can be used for glass sheets. Unstrengthened glass is glass that has been molten and shaped into sheets and then annealed, without undergoing any strengthening treatments such as air-cooling strengthening or chemical strengthening.

[0025] The thicknesses of the first glass 10 and the second glass plate 20 may be the same or different. The thickness of the first glass plate 10 may be 1.1 mm or more and 3.5 mm or less. If the thicknesses of the first glass plate 10 and the second glass plate 20 are different, the thickness of the second glass plate 20 may be 0.5 mm or more and 2.3 mm or less. Furthermore, the composition (materials constituting the glass plates, manufacturing methods of the glass plates, etc.) of the first glass 10 and the second glass plate 20 may be the same or different. Additionally, the overall thickness of the laminated glass 1 for vehicles may be 2.3 mm or more and 8.0 mm or less.

[0026] The material of the interlayer 30, which is disposed between the first glass plate 10 and the second glass plate 20 and bonds the first glass plate 10 and the second glass plate 20, is not particularly limited, but a thermoplastic resin is preferred. Examples of materials for the interlayer 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, and ionomer resins, which have been conventionally used for this purpose. Furthermore, the resin composition containing modified block copolymer hydrogenates described in Japanese Patent No. 6065221 may also be suitably used. Among these, plasticized polyvinyl acetal resins are suitable from the perspective of a good balance of various properties such as transparency, weather resistance, strength, adhesion, penetration resistance, impact energy absorption, moisture resistance, thermal insulation, and sound insulation. The aforementioned thermoplastic resins can be used alone or in combination of two or more. In the above-mentioned plasticized polyvinyl acetal resins, "plasticized" means that plasticization can be achieved by adding plasticizers. The same meaning applies to other plasticized resins.

[0027] The interlayer 30 can also be a plasticizer-free resin. Plasticizer-free resins can be, for example, ethylene-vinyl acetate copolymer resins. Examples of the aforementioned polyvinyl alcohol acetal resins include polyvinyl alcohol formal resin obtained by reacting polyvinyl alcohol (PVA) with formaldehyde, polyvinyl alcohol acetal resin obtained by reacting PVA with acetaldehyde, and polyvinyl alcohol butyral resin (PVB) obtained by reacting PVA with n-butyraldehyde. Among these, PVB is particularly suitable from the perspective of its excellent balance of various properties such as transparency, weather resistance, strength, adhesion, penetration resistance, impact energy absorption, moisture resistance, thermal insulation, and sound insulation. These polyvinyl alcohol acetal resins can be used alone or in combination of two or more.

[0028] A shielding layer can be provided around the periphery of the laminated glass 1 for use in vehicles to protect the sealant or similar material that adheres and holds the glass 1 to the vehicle body when it is installed in a vehicle opening. The shielding layer can be formed, for example, by applying a ceramic color paste containing a molten glass frit with black pigment and then firing it. The shielding layer can be provided on one or more of the second surface 12, the third surface 21, and the fourth surface 22 of the laminated glass 1 for vehicles.

[0029] The laminated glass 1 for vehicles can be bent entirely or partially. In this case, the glass plates (first glass plate 10 and second glass plate 20) can be bent to a specified curvature. The radius of curvature of the glass plates can be 1,000 to 100,000 mm. When the laminated glass 1 for vehicles is bent, it can be bent in a way that protrudes towards the first surface 11 of the first glass plate 10 and the third surface 21 of the second glass plate 20, that is, towards the outside of the vehicle. In the case where the glass plate is an inorganic glass with a curved shape, the glass plate can be bent by gravity forming, pressure forming, etc. after float forming. Bending is performed by heating to soften the glass. The heating temperature of the glass during bending is about 550°C to 700°C. The laminated glass 1 for vehicles can be a single-curved shape formed only in one direction, for example, when installed in an opening of a car 100, it can be bent only in the front-rear direction or the vertical direction of the car 100. In addition, the laminated glass 1 for vehicles can also be a multi-curved shape formed by bending in both the front-rear direction and the vertical direction. The first glass plate 10 and the second glass plate 20 in the laminated glass for vehicles can have the same or different radii of curvature.

[0030] The requirements for laminated glass used in vehicles are increasingly stringent, encompassing various safety-related properties and functions. Particularly when laminated glass is used as window glass in vehicles, it must possess adequate robustness for window use while also ensuring safety for passengers and pedestrians in the event of a collision. In recent years, pedestrian protection has received significant attention, leading to specific requirements for vehicle glass, such as the Head Injury Criterion (HIC).

[0031] In this respect, the proportion of the region in the laminated glass for vehicles of this type where the breaking stress, as measured by the R30 method as described in ISO 1288-5 (2016), is 100 MPa or more and 600 MPa or less, is 90% or more of the transparent region. Preferably, this proportion is 95% or more, and more preferably 98% or more.

[0032] In this specification, the transparent area refers to the portion of laminated glass for vehicles excluding the shielding layer formed on the laminated glass for vehicles.

[0033] In this invention, the breaking stress or bending strength can be measured separately in multiple regions comprised of the laminated glass for vehicles. In this case, the measurement can be performed in the original state of the laminated glass for vehicles, or by cutting the laminated glass for vehicles to divide it and measuring the breaking stress in each of the divided regions. The size of the divided glass can be 100mm × 100mm, but is not limited to this size. The size of the divided glass only needs to be 60mm to 300mm × 60mm to 300mm. Furthermore, when cutting the laminated glass for vehicles, the measurement can be performed directly using the cut laminated glass, or the measurement can be performed on each glass plate after removing the interlayer from the laminated glass. Additionally, the measurement can be performed on each glass before it is manufactured into laminated glass. Therefore, the proportion of regions in the first glass plate 10 and / or the second glass plate 20 comprised of the laminated glass where the breaking stress measured using the R30 method as described in ISO 1288-5 (2016) is 100MPa or more and 600MPa or less in the transparent area is sufficient to be 90% or more. Furthermore, the determination of destructive stress is preferably performed before the vehicle-mounted laminated glass is installed on the vehicle.

[0034] The method described in ISO 1288-5 (2016) involves placing a plate of glass, the test object, on a support ring of a specified diameter. A load ring of a specified diameter smaller than the support ring is then applied to the plate, and the load at failure is measured. The failure stress value is then calculated according to the formula described in ISO 1288-5 (2016). In this case, when laminated glass for vehicles, such as windshields, is bent, the failure stress of the cut-out bend is measured. In this case, the formula described in ISO can be omitted; instead, an approximate formula can be derived through stress measurement, and the measured value can be substituted into this approximate formula to calculate the failure stress value.

[0035] By employing a configuration in this form where a specified proportion of the area having a defined destructive stress value is a transparent area, the robustness of the vehicle glass can be maintained, and the proportion of areas with strength within an appropriate range can be increased. This appropriate range of strength ensures safety for the human body even in the event of an impact. In other words, the in-plane strength is homogenized or averaged, causing the strength measured in multiple areas of the vehicle glass to converge within a more appropriate range. In other words, in-plane strength distribution or unevenness is suppressed. Therefore, according to this form, a vehicle glass that possesses overall robustness as a vehicle glass and improves safety for humans or other living beings in the event of an impact can be provided.

[0036] The aforementioned destructive stress is measured by applying a load to one side of the laminated glass for vehicles, which can be either the interior or exterior side of the vehicle. Specifically, the laminated glass for vehicles of this type exhibits a destructive stress of 100 MPa or more and 600 MPa or less, as measured by the method described in ISO 1288-5 (2016), when a load is applied from the interior side of the vehicle. This destructive stress is measured by the method described in ISO 1288-5 (2016), and / or, when a load is applied from the exterior side of the vehicle, the destructive stress is measured by the method described in ISO 1288-5 (2016), and the destructive stress is measured by the method of ISO 1288-5 (2016), and the destructive stress is measured by the method of ISO 1288-5 (2016), and the destructive stress is measured by the method of ISO 1288-5 (2016), and the destructive stress is measured by the method of ISO 1288-5 (2016). When the above proportions are met in the measurement when a load is applied from the interior side of the vehicle, the safety performance when impacted from the interior side is improved, which is preferred from the perspective of protecting passengers. When the above proportions are met in the measurement when a load is applied from the exterior side of the vehicle, the safety performance for both parties when impacted from the exterior side of the vehicle is improved, which is preferred from the perspective of protecting pedestrians.

[0037] In particular, the proportion of areas in the laminated glass for vehicles with a breaking stress greater than 600 MPa, as measured by the method described in ISO 1288-5 (2016), is preferably 5% or less of the transparent area. Furthermore, this proportion is preferably 3% or less, and more preferably 1% or less. With this configuration, areas of excessive strength in the laminated glass can be reduced or eliminated. Therefore, even in the event of a collision between a passenger or pedestrian and the laminated glass for vehicles, the likelihood of injury to the passenger or pedestrian's head from impacting areas of excessive strength can be reduced, thus improving safety performance.

[0038] Furthermore, in the above configuration, the side on which the load is applied when measuring the destructive stress can be either the outer side or the inner side of the vehicle. That is, the proportion of areas where the destructive stress is greater than 600 MPa, as measured by the method described in ISO 1288-5 (2016), when a load is applied from the outer side of the vehicle, is less than 5% of the visible area, and / or the proportion of areas where the destructive stress is greater than 600 MPa, as measured by the method described in ISO 1288-5 (2016), when a load is applied from the inner side of the vehicle, is less than 5% of the visible area. Here, it is particularly preferable that the destructive stress is measured by applying a load from the outer side of the vehicle, from the perspective of protecting pedestrians.

[0039] In a type of laminated glass for vehicles, it is preferable that the proportion of the area with a breaking stress of less than 100 MPa, as measured by the method described in ISO 1288-5 (2016), is 5% or less of the transparent area. This proportion is preferably 3% or less, and more preferably 1% or less. With the above configuration, the robustness of the laminated glass for vehicles can be reliably maintained.

[0040] In the above configuration, the side on which the load is applied when measuring the breaking stress can be either the outer side or the inner side of the vehicle. That is, the proportion of the area where the breaking stress is less than 100 MPa when the load is applied from the inner side of the vehicle by the method described in ISO 1288-5 (2016) is less than 5% of the transparent area, and / or the proportion of the area where the breaking stress is less than 100 MPa when the load is applied from the outer side of the vehicle by the method described in ISO 1288-5 (2016) is less than 5% of the transparent area.

[0041] Furthermore, when loads are applied from the inside or outside of the vehicle, it is more preferable that the proportion of areas with a breaking stress greater than 600 MPa, as measured by the method described in ISO 1288-5 (2016), is 5% or less of the transparent area, and the proportion of areas with a breaking stress less than 100 MPa, as measured by the aforementioned method, is 5% or less of the transparent area. This further reduces or eliminates areas of excessive strength and suppresses intensity distribution. Therefore, it is possible to further achieve the effect of having the robustness of laminated glass for vehicles while reducing or preventing injury to the human body even in the event of a collision between the laminated glass and a person. Moreover, when the aforementioned breaking stress is a value measured by applying a load from the outside of the vehicle, it is particularly preferable from the perspective of protecting pedestrians.

[0042] <Manufacturing Methods for Vehicle Glass>

[0043] The aforementioned vehicle glass can be manufactured using a manufacturing method according to one aspect of the present invention, as described below. Specifically, the manufacturing method of one aspect of the vehicle laminated glass according to the present invention involves forming the vehicle laminated glass by laminating a first glass panel disposed on the outer side of the vehicle and a second glass panel disposed on the inner side of the vehicle through an interlayer film. The first glass panel has a first surface on the outer side of the vehicle and a second surface on the inner side of the vehicle, and the second glass panel has a third surface on the outer side of the vehicle and a fourth surface on the inner side of the vehicle. At least one of the first to fourth surfaces undergoes a strength averaging treatment. The strength averaging treatment can be performed on each glass panel before forming the vehicle laminated glass, or after forming the vehicle laminated glass.

[0044] Strength averaging treatment is a process to suppress in-plane strength distribution or uneven strength in laminated glass for vehicles. In other words, it is a measure to narrow the distribution of strength values ​​(breaking stress or flexural strength) measured in multiple regions within the laminated glass for vehicles. Strength averaging treatment can be applied to at least one of the first surface 11, second surface 12, third surface 21, and fourth surface 22 of the laminated glass 1 for vehicles. Figure 2 The strength averaging treatment is particularly preferably performed on one or more of the second surface 12, the third surface 21, and the fourth surface 22 of the laminated glass for vehicles.

[0045] Strength averaging treatment (also known as strength homogenization treatment or strength control treatment) can be carried out by bringing a substance into contact with the surface of laminated glass for vehicles or the surface of the glass sheet used to make laminated glass for vehicles.

[0046] As an example of strength averaging treatment, a tool can be used to contact the surface of a glass plate. The shape of the tool is not particularly limited; it can be a film or sheet, a roller, a brush, or bristles, and may or may not be flexible or elastic. It can also be disc-shaped or blade-shaped. Furthermore, the tool can be made of ceramic, metal, resin, etc. It can also be an object formed from foam, such as a foamed resin molded body or a foamed resin sheet, or an object formed from fibers, such as a fibrous structure formed by assembling fibers three-dimensionally or planarly, particularly cloth, non-woven fabric, paper, etc. When the tool is made of resin, or the material of the tool contains resin, specific examples of resin include ultra-low density polyethylene, linear low density polyethylene, low density polyethylene, high density polyethylene, polypropylene, polystyrene, polyurethane, silicone resin, EVA, and olefin elastomers. The tool can be made from one of the above materials or from a combination of two or more of the above materials.

[0047] Preferably, the surface of the tool has fine irregularities at least in the portion that contacts the glass plate. Such fine irregularities on the surface of the tool can be formed by roughening the surface of the portion of the tool that contacts the glass plate, fixing it after attaching fine powder, or kneading powder into the material during the molding of resin or other materials.

[0048] When the tool is in contact with the glass plate, it can move relative to the glass plate while in contact. Furthermore, when the tool is in contact with the glass plate, this can be achieved by applying a specified pressing force, or by not applying or substantially not applying pressing force.

[0049] Furthermore, as a tool component, a soft roller coated with a foaming agent having a micro-textured coating can be passed through a flexible core to contact the glass. Alternatively, a sheet with an uneven surface can be used to contact the surface of the glass plate. This allows for efficient strength averaging on the production line.

[0050] Furthermore, during the strength averaging process, the tool can be brought into contact with the glass plate in the presence of a liquid. The liquid can be any liquid that will not denature the glass or the tool; there are no particular limitations, and water, aqueous solutions, or organic solvents can be used. The liquid can be volatile or non-volatile.

[0051] In other examples of strength averaging treatment, the powder may be brought into contact with the surface of the laminated glass or glass plate. Therefore, for example, after the powder is dispersed on the surface of the glass plate, the surface of the glass plate can be wiped with the aforementioned tool, or the powder can be removed by cleaning after sweeping. When wiping or cleaning the surface of the glass plate with the aforementioned tool, the powder can be wiped or cleaned directly, or a liquid such as water can be added for wiping or cleaning. Furthermore, the tool can be placed in contact with the powder and supported thereon, and while applying pressure or not, the tool can be moved relative to the glass plate along its surface. The tool used in the strength averaging treatment with powder can be the same tool used in the above examples where strength averaging treatment is performed by bringing the tool into contact with the surface of the glass plate.

[0052] The powder used in the strength averaging treatment of powders may contain inorganic or organic materials, or both, but inorganic powders are preferred. Examples of inorganic powders include cerium oxide, glass beads, titanium dioxide, diamond, calcium carbonate, anhydrous silicate, sodium hydrogen phosphate, silicon nitride, silicon carbide, and alumina. These powders may be used alone or in combination of two or more. The powder used may have an average particle size of 10 nm or more and 100 μm or less, as determined by sedimentation. Furthermore, the powder may be used in a dry state, in a state moistened with liquid, or in a slurry form. The liquid used with the powder is not particularly limited as long as it does not denature the glass or the powder; water, aqueous solutions, or organic solvents may be used. The liquid may be volatile or non-volatile.

[0053] While the detailed mechanism by which strength averaging treatment averages the strength of automotive glass is not yet fully understood, it is believed to be related to microcracks (also known as microcracks, invisible microcracks below the nanometer scale) on the glass surface. That is, the surface of the manufactured glass originally contains microcracks, and the uneven presence of these microcracks is the main cause of strength inhomogeneity in automotive glass. However, strength averaging treatment can introduce new cracks into the glass surface, which can reduce the strength of areas with excessively high strength. However, strength averaging treatment does not further reduce the strength of areas that were originally low in strength, or it reduces the strength of areas that were originally low in strength by almost nothing; therefore, the result is that the strength within the surface can be averaged.

[0054] Furthermore, when laminated glass for vehicles is impacted, the impact can be absorbed by creating breakage or cracks in the glass. However, if a certain degree of breakage or cracking is easily generated on the surface opposite to the impacted side, the impact is particularly easily absorbed. Therefore, by performing strength averaging treatment on the surface opposite to the impacted side to reduce or eliminate areas of excessive strength, the impact can be easily absorbed. Therefore, from the perspective of reducing or eliminating the damage to pedestrians when the laminated glass for vehicles collides with a pedestrian from the outside of the vehicle, it is preferable to perform strength averaging treatment on one or more of the second surface 12 and the fourth surface 22, and it is even more preferable to perform it on at least the second surface 12, which is more affected by the impact. On the other hand, for the same reason, from the perspective of reducing or eliminating the damage to passengers when the laminated glass for vehicles collides with a passenger from the inside of the vehicle, it is preferable to perform strength averaging treatment on one or more of the third surface 21 and the first surface 11, and it is even more preferable to perform it on at least the third surface 21, which is more affected by the impact.

[0055] Example

[0056] In this embodiment, a strength test was conducted on a glass plate that had undergone strength averaging treatment and an untreated glass plate, and the two were compared.

[0057] [Experiment 1]

[0058] (Example 1)

[0059] Eight glass plates, each 66mm x 66mm and 2mm thick, manufactured under identical conditions, were prepared. Strength averaging treatment was applied to one side of each glass plate. Approximately 10g of each of the eight powders (Kanto loam) listed in JIS Z8901 "Test Powders and Test Particles" was spread out on a 200cm² area of ​​cloth. 2 Spread the powder evenly over a wide area, then evenly sprinkle 100 ml of water from above onto the area where the powder was placed. Next, place the powder-coated side of the cloth on the glass plate surface, apply approximately 3 kg of pressure, and rub the cloth against the glass plate surface with a 6 cm stroke for 2 seconds, repeating this process 3 times. A strength test was then conducted on the glass plate after this strength averaging treatment.

[0060] (Example 2)

[0061] Eight glass plates identical to the untreated glass plates prepared in Example 1 were prepared and strength tests were conducted.

[0062] <Strength Test>

[0063] The strength of the glass plates in Examples 1 and 2 was determined as the breaking stress (MPa) as described below. The breaking stress was determined with R30 according to ISO 1288-5 (2016). More specifically, the breaking load was determined by applying a load at a rate of 0.3 mm per minute using a support ring with a diameter of 60 mm and a load ring with a diameter of 12 mm from the untreated surface (i.e., the untreated side) using the load ring. The breaking stress was calculated using the formula described in ISO 1288-5 (2016).

[0064] The results are shown in Figure 3 .like Figure 3 As shown, the average failure stress was 455 MPa without averaging treatment (Example 2), which decreased to 352 MPa after averaging treatment (Example 1). Furthermore, the highest failure stress decreased significantly from 752 MPa without averaging treatment (Example 2) to 552 MPa after averaging treatment (Example 1). This indicates that areas with excessively high failure stress (strength) were eliminated. The lowest failure stress was 148 MPa without averaging treatment (Example 2), compared to 156 MPa after averaging treatment (Example 1), showing minimal change. This demonstrates that strength averaging treatment suppressed the distribution of in-plane strength.

[0065] [Experiment 2]

[0066] (Example 3)

[0067] Prepare an outer sheet of 2mm thick glass that is formed in the same process as mass-produced windshield glass. Figure 2 Symbol 10 in the middle), inner plate ( Figure 2 (symbol 20 in the text). Furthermore, eight types of powder and cotton cloth were used on the third surface ( Figure 2 The inner panel 20 (represented by symbol 21) undergoes the same averaging treatment as in Experiment 1. After treatment, the glass plate is cleaned and returned to the mass production process, where the outer and inner panels are processed to form laminated glass, thus producing the front window glass. The resulting front window glass is composed of a 2mm thick glass plate, a 0.76mm thick PVB interlayer film, and a 2mm thick glass plate laminated together. Figure 4 (The diagram shows the windshield glass produced when viewed from the outside of the vehicle.) Twelve 100mm x 100mm samples (numbered S1 to S12) were cut from the center of the windshield glass.

[0068] (Example 4)

[0069] Except for the absence of averaging, the windshield was manufactured in the same manner as in Example 3, such as... Figure 4 As shown, 12 100mm×100mm samples were cut from the center of the front window glass.

[0070] <Strength Test>

[0071] Except for the sample size of 100mm × 100mm and the loading speed of 1mm per minute, the measurements were performed according to ISO 1288-5 (2016) with R30, the same as in [Experiment 1]. More specifically, a support ring with a diameter of 60mm and a load ring with a diameter of 12mm were used, and the load ring was used to load the inner plate ( Figure 2 A load was applied to the inner plate 20 (represented by symbol 22) and the failure load was measured. To calculate the failure stress, a strain gauge (Kyowa Denko KFGS-5-120-D17-11) was used to determine the load-stress relationship between the two samples, and the failure stress was calculated.

[0072] The results are shown in Figure 5 .like Figure 5 As shown, the average failure stress was 397 MPa without averaging (Example 4), which decreased to 350 MPa after averaging (Example 3). Furthermore, the highest failure stress decreased significantly from 684 MPa without averaging (Example 4) to 499 MPa after averaging (Example 3). This indicates that areas with excessively high failure stress (strength) were eliminated. The lowest failure stress was 147 MPa without averaging (Example 4), compared to 160 MPa after averaging (Example 3), showing minimal change. This demonstrates that strength averaging suppressed the in-plane strength distribution. Additionally, the results do not include samples with strain gauges.

[0073] This application claims priority based on Japanese Patent Application No. 2020-015447, filed with the Japan Patent Office on January 31, 2020, the entire contents of which are incorporated herein by reference.

[0074] Symbol Explanation

[0075] 1. Laminated glass

[0076] 10 First Glass Plate

[0077] 11 First Surface

[0078] 12 Second Surface

[0079] 20 Second glass plate

[0080] 21 Third Surface

[0081] 22 Fourth Surface

[0082] 30 Intermediate Membrane

[0083] 100 cars.

Claims

1. Laminated glass for vehicles, comprising a first glass panel disposed on the outer side of the vehicle and a second glass panel disposed on the inner side of the vehicle, wherein, The first glass panel has a first surface on the outer side of the vehicle and a second surface on the inner side of the vehicle. The second glass panel has a third surface on the outer side of the vehicle and a fourth surface on the inner side of the vehicle. One or more of the second and fourth surfaces are subjected to strength averaging treatment and thus have cracks. The proportion of areas with destructive stress of 100 MPa or more and 600 MPa or less, as determined by the method described in ISO 1288-5 (2016), is more than 90% of the transparent area.

2. The laminated glass for vehicles as described in claim 1, characterized in that, The proportion of areas with a destructive stress greater than 600 MPa, as determined by the method described in ISO 1288-5 (2016), is less than 5% of the transparent area.

3. The laminated glass for vehicles as described in claim 1 or 2, characterized in that, The proportion of areas with a destructive stress of less than 100 MPa, as determined by the method described in ISO 1288-5 (2016), is less than 5% of the transparent area.

4. The laminated glass for vehicles as described in claim 1 or 2, characterized in that, The destructive stress is a value measured by applying a load to the inside of the vehicle.

5. The laminated glass for vehicles as described in claim 4, characterized in that, The destructive stress is a value measured by applying a load to the outside of the vehicle.

6. The laminated glass for vehicles as described in claim 1 or 2, characterized in that, The destructive stress was a value measured before the laminated glass was installed on the vehicle.

7. The laminated glass for vehicles as described in claim 1 or 2, characterized in that, It is the windshield glass.

8. An automobile, characterized in that, The vehicle laminated glass comprises any one of claims 1 to 7.

9. A method for manufacturing laminated glass for vehicles, characterized in that, The laminated glass for vehicles is formed by laminating a first glass panel disposed on the outside of the vehicle and a second glass panel disposed on the inside of the vehicle with an interlayer film. The first glass panel has a first surface on the outer side of the vehicle and a second surface on the inner side of the vehicle. The second glass panel has a third surface on the outer side of the vehicle and a fourth surface on the inner side of the vehicle. Intensity averaging treatment is applied to one or more of the second and fourth surfaces. Through the aforementioned strength averaging treatment, the proportion of the region in the laminated glass for vehicles with a breaking stress of 100 MPa or more and 600 MPa or less, as determined by the method described in ISO 1288-5 (2016), is more than 90% of the transparent region.

10. The method for manufacturing laminated glass for vehicles as described in claim 9, characterized in that, The strength averaging treatment is performed using powder.

11. The method for manufacturing laminated glass for vehicles as described in claim 9, characterized in that, The strength averaging process is performed by contacting a tool with a surface having fine irregularities.

12. The method for manufacturing laminated glass for vehicles as described in claim 10 or 11, characterized in that, The intensity averaging process is performed in the presence of a liquid.

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