JPWO2017183381A1 - Laminated glass for vehicles - Google Patents

Abstract

  The laminated glass for vehicles of the present invention is a laminated glass for vehicles in which an inner glass plate and an outer glass plate are integrated via an organic resin intermediate layer, and the inner glass plate is a chemically strengthened glass having a compressive stress layer on the surface. And the outer glass plate is a physically tempered glass having a compressive stress layer on the surface thereof.

Description

  The present invention relates to a laminated glass for a vehicle, and more particularly to a laminated glass for a vehicle suitable for a windshield of an automobile.

  A laminated glass in which two glass plates are integrated with an organic resin intermediate layer is used for a windshield of an automobile. Laminated glass can ensure good visibility even if part of the glass plate breaks, and even if the glass plate breaks in the event of an accident, the stretch of the organic resin intermediate layer allows the passenger to go outside the vehicle. There is an advantage that it can be prevented from jumping out.

  For example, Patent Document 1 discloses that the ratio of the thickness of the outer glass plate to the thickness of the inner glass plate is 0.6 or more and 0.9 or less in order to prevent breakage of the intermediate layer when the airbag is deployed. Laminated glass is disclosed. Moreover, in patent document 2, in order to improve crime prevention etc., the difference of the thickness of an inner side glass plate and an outer side glass plate shall be 1.0 mm or more, and the plate | board thickness of an inner side glass plate is made more than the plate | board thickness of an outer side glass plate. Larger laminated glass is disclosed.

JP 2003-55007 A JP 2001-39743 A

  In recent years, in the automobile industry, from the environmental point of view, it is strongly demanded to improve fuel consumption by reducing the weight of the vehicle body. As a result, weight reduction of automobile-related parts is required more than ever. The requirement for laminated glass is no exception. In order to reduce the weight of the laminated glass, it is effective to reduce the thickness of the glass plate, but its realization is not easy from the viewpoint of safety and the like. Therefore, in order to reduce the thickness of the laminated glass, it is assumed that thin physically strengthened glass is used as the glass plate.

  However, it is difficult to increase the compressive stress value of the compressive stress layer in the thin physical tempered glass because it is difficult to form a temperature difference between the surface and the inside during the heat treatment. As a result, it becomes difficult to maintain the strength of the laminated glass.

  Furthermore, when physically strengthened glass is installed in a place close to the human body, the physically strengthened glass is broken into particles due to physical impact, and the fine fragments may damage the eyeball or the like.

  Therefore, the present invention has been made in view of the above circumstances, and its technical problem is that it is possible to achieve both high strength and thinning, and can effectively avoid the risk of human body damage at the time of breakage. The idea is to create a laminated glass.

  The present inventor has found that the above technical problem can be solved by using a chemically strengthened glass plate and a physically strengthened glass plate as laminated glass, and disposing the physically strengthened glass outside, and proposes the present invention. . That is, the laminated glass for vehicles according to the present invention is a laminated glass for vehicles in which an inner glass plate and an outer glass plate are integrated via an organic resin intermediate layer, and the inner glass plate has a compressive stress layer on its surface. It is glass and the outer glass plate is a physically tempered glass having a compressive stress layer on the surface. Here, the “inner glass plate” refers to a glass plate disposed on the vehicle inner side, and the “outer glass plate” refers to a glass plate disposed on the vehicle outer side. In addition, when a laminated glass has the curved-surface shape curved in three dimensions, a glass plate with a small curvature radius turns into an inner side glass plate, and a glass plate with a large curvature radius turns into an outer side glass plate.

  In the laminated glass for vehicles of the present invention, the inner glass plate is chemically strengthened glass. As a result, the strength can be maintained even when the plate thickness is small, and the risk of the granular glass piece damaging the human body inside the vehicle at the time of breakage can be reduced. Moreover, the laminated glass for vehicles of this invention uses the outer side glass plate as physically strengthened glass. Physically tempered glass tends to increase the stress depth. For this reason, an outer side glass plate becomes difficult to be damaged by the point impact of fine flying objects, such as gravel. Furthermore, in the laminated glass for vehicles of the present invention, two glass plates are integrated with an organic resin intermediate layer. Thereby, it is possible to prevent the passenger from jumping out of the vehicle when an accident occurs.

  FIG. 1 is a schematic view for explaining a laminated glass for a vehicle according to the present invention. A laminated glass 10 for a vehicle includes an inner glass plate 11 made of chemically strengthened glass, an outer glass plate 12 made of physically strengthened glass, an organic resin intermediate layer 13 sandwiched between the inner glass plate 11 and the outer glass plate 12, It has. And the laminated glass 10 for vehicles makes the outer side glass plate 12 side convex, the whole board width direction curves in an arc shape, and the whole length direction curves in an arc shape.

  Secondly, it is preferable that the laminated glass for vehicles of the present invention has a curved shape that is three-dimensionally curved.

  Thirdly, in the laminated glass for vehicles of the present invention, the inner glass plate is preferably alkali aluminosilicate glass, and the plate thickness is preferably 1.5 mm or less.

Fourthly, in the laminated glass for vehicles of the present invention, the inner glass plate has a glass composition of mass%, SiO ₂ 40-80%, Al ₂ O ₃ 1-30%, B ₂ O ₃ 0-10%. , Na ₂ O 5 to 20%, K ₂ O 0 to 5% is preferable.

  Fifth, in the laminated glass for vehicles of the present invention, it is preferable that the compressive stress value of the compressive stress layer of the inner glass plate is 300 MPa or more and the stress depth is 5 μm or more. Here, the “compressive stress value” and the “stress depth” are calculated by observing the number of interference fringes and their intervals using a surface stress meter (for example, FSM-6000 manufactured by Orihara Seisakusho Co., Ltd.). is there.

  Sixth, the laminated glass for vehicles of the present invention preferably has a crack occurrence rate of 80% or less on the inner glass plate before chemical strengthening when a load of 800 gf is applied with a Vickers indenter. Here, the “crack rate” is a value measured as follows. First, in a constant temperature and humidity chamber maintained at a humidity of 30% and a temperature of 25 ° C., a Vickers indenter set to a load of 800 gf is driven into the glass surface (optical polishing surface) for 15 seconds, and 15 seconds later, it is generated from the four corners of the indentation. Count the number of cracks (maximum 4 per indentation). Thus, after indenting 50 times and calculating | requiring the total number of crack generation, it calculates | requires by the formula of (total number of crack generation / 200) x100. The Vickers indenter can be driven by a fully automatic Vickers hardness tester (for example, FLEC-50VX manufactured by Huatetec). However, since the crack generation rate varies depending on the moisture state of the glass surface, annealing is performed for 1 hour or more in the temperature range of (Ps-350 ° C.) to (Ps-150 ° C.) before measurement. It is desirable to cancel the difference in moisture state on the surface. Ps indicates a strain point.

  Seventh, in the laminated glass for vehicles of the present invention, the outer glass plate is preferably alkali aluminosilicate glass or soda lime glass, and the plate thickness is preferably 1.0 to 4.0 mm.

  Eighth, in the laminated glass for vehicles of the present invention, the organic resin layer is preferably composed of an ethylene vinyl acetate copolymer or polyvinyl butyral.

  Ninth, the laminated glass for vehicles of the present invention is preferably used for a windshield of an automobile.

It is the schematic which shows an example of the laminated glass for vehicles of this invention.

  In the laminated glass for vehicles of the present invention, the inner glass plate and the outer glass plate have a compressive stress layer on the surface. As a method for forming a compressive stress layer on the surface, there are a physical strengthening method and a chemical strengthening method. In the present invention, the inner glass plate is a chemically strengthened glass, and the outer glass plate is a physically strengthened glass.

  The chemical strengthening method is a method of introducing alkali ions having a large ion radius to the glass surface by ion exchange at a temperature below the strain point of the glass. If it is a chemical strengthening method, even when the plate | board thickness of a glass plate is small, a compressive-stress layer can be formed appropriately. The physical strengthening method is a method of forming a compressive stress layer on the surface by heat-treating at a temperature near the softening point of the glass, and then rapidly cooling the glass with an air jet after processing a curved surface at a temperature particularly near the softening point of the glass. . If it is physically strengthened glass, a compressive stress layer having a large stress depth can be easily formed.

  In the laminated glass for vehicles of the present invention, the thickness of the inner glass plate is preferably 1.5 mm or less, 1.2 mm or less, 1.0 mm or less, particularly 0.8 mm or less, preferably 0.3 mm or more, 0 4 mm or more, 0.5 mm or more, 0.6 mm or more, particularly 0.7 mm or more. The thickness of the outer glass plate is preferably 4.0 mm or less, 3.5 mm or less, 3.0 mm or less, 2.5 mm or less, 2.0 mm or less, 1.8 mm or less, particularly 1.5 mm or less, preferably It is 0.3 mm or more, 0.4 mm or more, 0.5 mm or more, 0.6 mm or more, 0.7 mm or more, 0.8 mm or more, 0.9 mm or more, particularly 1.0 mm or more. The plate thickness of the laminated glass is preferably 4.5 mm or less, 3.5 mm or less, 3.0 mm or less, 2.5 mm or less, 2.0 mm or less, particularly 1.5 mm or less. If each plate thickness is too large, it will be difficult to reduce the weight of the laminated glass. On the other hand, when each plate thickness is too small, it becomes difficult to obtain a desired strength.

  In particular, if the inner glass plate is regulated to 0.3 to 1.0 mm and the outer glass plate is regulated to 1.0 to 1.5 mm, mechanical impact force is easily absorbed elastically. When applied to, it becomes difficult to be scratched.

  In the laminated glass for vehicles of the present invention, the inner glass plate is preferably alkali aluminosilicate glass. Since alkali aluminosilicate glass has high ion exchange performance, it is possible to form a desired compressive stress layer in a short time of chemical strengthening treatment. Further, since the devitrification resistance is good, it can be easily formed into a glass plate.

The inner glass sheet, as a glass composition, in _{mass%, SiO 2 40~80%, Al} 2 O 3 1~30%, B 2 O 3 0~10%, Na 2 O 5~20%, K 2 O 0 It is preferable to contain -5%. The reason why the content range of each component is regulated as described above is shown below. In addition, in description of the containing range of each component,% display shall show the mass%.

SiO ₂ is a component that forms a network of glass. The content of SiO ₂ is preferably 40 to 80%, 45 to 75%, 52 to 73%, 55 to 71%, 57 to 68%, particularly 58 to 67%. If the content of SiO ₂ is too small, vitrification becomes difficult, and the thermal expansion coefficient becomes too high, so that the thermal shock resistance tends to decrease. On the other hand, if the content of SiO ₂ is too large, the meltability and formability tend to be lowered, and the thermal expansion coefficient becomes too low, making it difficult to match the thermal expansion coefficient of the outer glass plate.

Al ₂ O ₃ is a component that improves ion exchange performance, and is a component that increases the strain point and Young's modulus. When the content of Al ₂ O ₃ is too small, resulting is a possibility which can not be sufficiently exhibited ion exchange performance. Therefore, the lower limit range of Al ₂ O ₃ is preferably 1% or more, 3% or more, 8% or more, 12% or more, 16% or more, 16.5% or more, 17.1% or more, 17.5% or more. , 18% or more, particularly 18.5% or more. On the other hand, when the content of Al ₂ O ₃ is too large, devitrification crystal glass becomes easy to precipitate, and it becomes difficult to mold the glass sheet by an overflow down draw method or the like. Moreover, acid resistance also falls and it becomes difficult to apply to an acid treatment process. Furthermore, the high-temperature viscosity becomes high and the meltability tends to be lowered. Therefore, the upper limit range of Al ₂ O ₃ is preferably 30% or less, 28% or less, 26% or less, 24% or less, 23.5% or less, 22% or less, 21% or less, particularly 20.5% or less. is there.

B ₂ O ₃ is a component that lowers the crack generation rate, high-temperature viscosity, and density, stabilizes the glass, makes it difficult to precipitate crystals, and lowers the liquidus temperature. The lower limit range of B ₂ O ₃ is preferably 0% or more, 0.1% or more, 1% or more, 2% or more, particularly 3% or more. However, when the content of B ₂ O ₃ is too large, coloring of the glass surface called burnt occurs due to ion exchange, water resistance is lowered, and the stress depth tends to be small. Therefore, the upper limit range of B ₂ O ₃ is preferably 10% or less, 6% or less, 5% or less, and particularly less than 4%.

Na ₂ O is an ion exchange component, and is a component that lowers the high temperature viscosity and improves the meltability and moldability. Na ₂ O is also a component that improves devitrification resistance. When Na 2 _O content is too small, the melting property and ion exchange performance tends to decrease. Therefore, the content of Na ₂ O is preferably 5% or more, more than 7.0%, 10% or more, 12% or more, 13% or more, particularly 14% or more. On the other hand, when the content of Na ₂ O is too large, the thermal expansion coefficient becomes too high, and the thermal shock resistance is lowered or it is difficult to match the thermal expansion coefficient of the organic resin intermediate layer. In addition, the strain point may be excessively lowered or the component balance of the glass composition may be lost, and the devitrification resistance may be deteriorated. Therefore, the content of Na ₂ O is preferably 20% or less, 19% or less, 17% or less, 16.3% or less, 16% or less, and particularly 15% or less.

K ₂ O is a component that promotes ion exchange, and is a component that easily increases the stress depth among alkali metal oxides. Moreover, it is a component which reduces high temperature viscosity and improves a meltability and a moldability. Furthermore, it is also a component that improves devitrification resistance. However, when the content of K ₂ O is too large, the thermal expansion coefficient becomes too high, the thermal shock resistance is lowered, and it becomes difficult to match the thermal expansion coefficient of the organic resin intermediate layer. On the other hand, if the strain point is too low, the component balance of the glass composition is lost, and the devitrification resistance tends to be lowered. Therefore, the upper limit range of K ₂ O is preferably 5% or less, 4% or less, less than 2%, particularly less than 1%. Incidentally, when adding _{K 2} O, the addition amount thereof is preferably 0.1% or more, 0.3% or more, particularly 0.5% or more.

  In addition to the above components, for example, the following components may be added.

Li ₂ O is an ion exchange component, and is a component that lowers the high-temperature viscosity to increase the meltability and moldability, and also increases the Young's modulus. Furthermore, Li ₂ O has a large effect of increasing the compressive stress value among alkali metal oxides. However, in a glass system containing 5% or more of Na ₂ O, if the Li ₂ O content is extremely increased, the compressive stress is rather increased. The value tends to decrease. Further, when the content of Li 2 _O is too large, and decreases the liquidus viscosity, in addition to the glass tends to be devitrified, the thermal expansion coefficient becomes too high, the thermal shock resistance may decrease, It becomes difficult to match the thermal expansion coefficient of the organic resin intermediate layer. Furthermore, the low-temperature viscosity decreases too much, and stress relaxation is likely to occur, and the compressive stress value may decrease instead. Therefore, the content of Li ₂ O is preferably 0 to 5%, 0 to 3.5%, 0 to 2%, 0 to 1.5%, 0 to 1%, and less than 0.01 to 1.0%. In particular, it is 0.1 to 0.5%. When the Li ₂ O content is 0.1% or more, Li ions act as an ion exchange component, so that the stress depth can be increased in a short time. As a result, when the chemical strengthening process is performed a plurality of times, the first ion exchange time can be shortened.

  MgO is a component that lowers the high-temperature viscosity and increases the meltability, moldability, strain point, and Young's modulus, and is a component that has a large effect of improving ion exchange performance among alkaline earth metal oxides. Therefore, the lower limit range of MgO is preferably 0% or more, 0.5% or more, 1% or more, 1.2% or more, 1.3% or more, particularly 1.4% or more. However, when there is too much content of MgO, a density and a thermal expansion coefficient will become high easily and there exists a tendency for glass to devitrify easily. Therefore, the upper limit range of MgO is preferably 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3.5% or less, 3% or less, 2.5% or less, 2.3% or less, especially 2.2% or less.

  CaO is a component that increases the meltability, moldability, strain point, and Young's modulus by reducing the high-temperature viscosity without lowering the devitrification resistance compared to other components. However, if the content of CaO is too large, the density and thermal expansion coefficient become high, and the balance of the composition of the glass composition is lacking. On the contrary, the glass is liable to devitrify, the ion exchange performance is lowered, or the ion exchange. It becomes easy to degrade the solution. Therefore, the CaO content is preferably 0 to 6%, 0 to 5%, 0 to 4%, 0 to 3.5%, 0 to 3%, 0 to 2%, 0 to less than 1%, 0 to 0.5%, in particular 0-0.1%.

  SrO is a component that increases the meltability, moldability, strain point, and Young's modulus by lowering the high-temperature viscosity. However, if the content of SrO is too large, the ion exchange reaction is likely to be inhibited, and the density and thermal expansion coefficient are increased, and the glass is easily devitrified. Therefore, the content of SrO is preferably 0 to 2%, 0 to 1.5%, 0 to 1%, 0 to 0.5%, 0 to 0.1%, particularly less than 0 to 0.1%. is there.

  BaO is a component that lowers the high-temperature viscosity and increases meltability, moldability, strain point, and Young's modulus. However, when the content of BaO is too large, the ion exchange reaction is likely to be inhibited, and in addition, the density and the thermal expansion coefficient are increased, and the glass is easily devitrified. Therefore, the content of BaO is preferably 0 to 2%, 0 to 1.5%, 0 to 1%, 0 to 0.5%, 0 to 0.1%, particularly 0 to less than 0.1%. is there.

  When the total amount of MgO, CaO, SrO and BaO is too large, the density and the thermal expansion coefficient tend to increase, the glass becomes devitrified, and the ion exchange performance tends to decrease. Therefore, the total amount of MgO, CaO, SrO and BaO is preferably 0 to 9.9%, 0 to 8%, 0 to 6%, particularly 0 to 5%.

TiO ₂ is a component that enhances the ion exchange performance and is a component that lowers the high-temperature viscosity. However, if its content is too large, the glass tends to be colored or devitrified easily. Therefore, the content of TiO ₂ is preferably 0 to 4.5%, 0 to 0.5%, particularly 0 to 0.3%.

ZrO ₂ is a component that remarkably improves the ion exchange performance and a component that increases the viscosity and strain point in the vicinity of the liquid phase viscosity. However, if the content of ZrO ₂ is too large, the devitrification resistance may be remarkably reduced, and the density may be too high. Therefore, the content of ZrO ₂ is preferably 0 to 5%, 0 to 3%, 0 to less than 1%, particularly 0.001 to 0.5%.

  ZnO is a component that enhances the ion exchange performance, and is a component that is particularly effective in increasing the compressive stress value. Moreover, it is a component which reduces high temperature viscosity, without reducing low temperature viscosity. However, when the content of ZnO is too large, the glass tends to undergo phase separation, the devitrification resistance decreases, the density increases, or the stress depth decreases. Therefore, the content of ZnO is preferably 0 to 6%, 0 to 3%, 0 to 1%, particularly 0 to 0.1%.

P ₂ O ₅ is a component that enhances ion exchange performance, and in particular, a component that increases the stress depth. A suitable lower limit range of P ₂ O ₅ is 0% or more, 1% or more, 3% or more, 5% or more, particularly more than 7%. However, when the content of P ₂ O ₅ is too large, the glass phase separation, the water resistance tends to decrease. Therefore, the preferable upper limit range of the content of P ₂ O ₅ is 20% or less, 18% or less, 15% or less, 13% or less, 10% or less, particularly 7% or less.

SnO ₂ has an effect of improving ion exchange performance. Therefore, the content of SnO ₂ is preferably 0 to 3%, 0.01 to 3%, 0.05 to 3%, 0.1 to 3%, particularly 0.2 to 3%.

As a clarifier, one or more selected from the group of Cl, SO ₃ and CeO ₂ (preferably a group of Cl and SO ₃ ) may be added in an amount of 0 to 3%.

The content of Fe ₂ O ₃ is preferably less than 1000 ppm (less than 0.1%), less than 800 ppm, less than 600 ppm, less than 400 ppm, especially less than 300 ppm. Further, the Fe ₂ O ₃ content is regulated within the above range, and the molar ratio Fe ₂ O ₃ / (Fe ₂ O ₃ + SnO ₂ ) is set to 0.8 or more, 0.9 or more, particularly 0.95 or more. It is preferable to regulate. If it does in this way, it will become easy to improve the total light transmittance (400-770 nm) in plate | board thickness 1mm (for example, 90% or more).

Rare earth oxides such as Nd ₂ O ₃ and La ₂ O ₃ are components that increase the Young's modulus. However, the cost of the raw material itself is high, and when it is added in a large amount, the devitrification resistance tends to be lowered. Therefore, the rare earth oxide content is preferably 3% or less, 2% or less, 1% or less, 0.5% or less, particularly 0.1% or less.

From the environmental consideration, it is preferable that the glass composition does not substantially contain As ₂ O ₃ , Sb ₂ O ₃ , PbO, Bi ₂ O ₃ and F. Here, “substantially does not contain” means that the glass component does not actively add an explicit component, but allows it to be mixed as an impurity. It indicates that the content is less than 0.05%.

  In the laminated glass for vehicles of the present invention, the inner glass plate has a compressive stress layer on the surface, and the compressive stress value of the compressive stress layer is preferably 300 MPa or more, 500 MPa or more, 600 MPa or more, 650 MPa or more, particularly 700 MPa or more. is there. The greater the compressive stress value, the higher the strength of the inner glass plate. On the other hand, when an extremely large compressive stress is formed on the surface, the internal tensile stress becomes extremely high, and the inner glass plate may be self-destructed due to a point collision. Therefore, the compressive stress value of the compressive stress layer is preferably 1200 MPa or less.

  The stress depth of the compressive stress layer of the inner glass plate is preferably 5 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, particularly 50 μm or more. The greater the stress depth, the harder the inner glass plate breaks and the less the variation in strength, even if the inner glass plate is deeply scratched. On the other hand, if the stress depth is too large, the internal tensile stress becomes extremely high, and the inner glass plate may be self-destructed by point collision. Therefore, the stress depth is preferably 70 μm or less.

  The tensile stress value inside the inner glass plate is preferably 200 MPa or less, 150 MPa or less, 90 MPa or less, 70 MPa or less, particularly 10 to 50 MPa. If the internal tensile stress value is too large, the glass plate may be destroyed by point collision. The internal tensile stress value is a value calculated from the following mathematical formula.

  The compressive stress curve in the depth direction from the surface of the inner glass plate is preferably bent. If it does in this way, it will become easy to prevent internal stress destruction, increasing the compressive stress value and stress depth of a compressive stress layer. In addition, when a chemical strengthening process is performed in multiple times, the compressive stress curve in the depth direction can be bent from the surface.

  In the case of performing chemical strengthening treatment a plurality of times, the temperature of the last chemical strengthening treatment (for example, in the case of two chemical strengthening treatments, the second chemical strengthening treatment) is preferably 390 to 430 ° C, particularly 400 to 420 ° C. The time for the last chemical strengthening treatment is preferably 1.5 to 5 hours, in particular 2 to 4.5 hours. If it does in this way, it will become easy to raise the compressive stress value of a compressive stress layer.

  When performing the chemical strengthening process a plurality of times, it is preferable to perform the chemical strengthening process twice. In this way, the compressive stress curve in the depth direction from the surface can be bent efficiently.

  When the chemical strengthening treatment is performed twice, the ratio of small alkali ions (for example, Li ions, Na ions, particularly Na ions) in the ion exchange solution used for the second chemical strengthening treatment is the ion used for the first chemical strengthening treatment. Less than that in the exchange liquid is preferred. This makes it easier to increase the compressive stress value of the compressive stress layer. The size of the alkali ions is Li ion <Na ion <K ion.

When the chemical strengthening treatment is performed twice, the content of KNO ₃ in the ion exchange solution used for the first chemical strengthening treatment is preferably less than 75% by mass, 70% by mass or less, particularly 60% by mass or less. The content of KNO ₃ in the ion exchange solution used for the second chemical strengthening treatment is preferably 75% by mass or more, 85% by mass or more, 95% by mass or more, particularly 99.5% by mass or more. When the content of KNO ₃ in the ion exchange solution is out of the above range, it is difficult to increase the compressive stress value of the compressive stress layer.

When the chemical strengthening treatment is performed twice, the content of NaNO _{3 in} the ion exchange solution used for the second chemical strengthening treatment is smaller than the content of NaNO _{3 in} the ion exchange solution used for the first chemical strengthening treatment. It is preferably 5% by mass or less, more preferably 10% by mass or less, and particularly preferably 15% by mass or more. Further, the content of NaNO ₃ in the ion exchange solution used for the second chemical strengthening treatment is preferably 25% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, and particularly 5% by mass or less. 0.5% by mass or less. If there is too much NaNO ₃ in the ion exchange solution used for the second chemical strengthening treatment, it is difficult to increase the compressive stress value of the surface compressive stress layer.

[Equation 1]
Internal tensile stress value = (compressive stress value × stress depth) / (plate thickness−2 × stress depth)

  In the laminated glass for vehicles of the present invention, the crack occurrence rate of the inner glass plate before chemical strengthening treatment when a load of 800 gf is applied with a Vickers indenter is preferably 80% or less. If this crack generation rate is too large, when a flying object collides with the outer glass plate and local stress is applied, cracks are likely to occur in the inner glass plate, which may lead to the destruction of the entire laminated glass. .

  In the laminated glass for vehicles of the present invention, the outer glass plate is a physically strengthened glass having a compressive stress layer on the surface. The compressive stress value of the compressive stress layer of the outer glass plate is preferably 1 MPa or more, 5 MPa or more, 10 MPa or more, 20 MPa or more, 50 MPa or more, particularly 100 MPa or more. The greater the compressive stress value, the higher the strength of the outer glass plate. The stress depth of the compressive stress layer of the outer glass plate is preferably 50 μm or more, 100 μm or more, or 150 μm or more. When the stress depth of the outer glass plate is too small, the point impact resistance against flying objects tends to be lowered. The tensile stress value inside the outer glass plate is preferably 90 MPa or less, 70 MPa or less, particularly 10 to 50 MPa. If the tensile stress value inside the outer glass is too large, glass fragments may be shattered at the time of breakage, resulting in a temporary poor visibility and a very dangerous situation.

As the outer glass plate, the alkali aluminosilicate glass is preferable, but from the viewpoint of production cost, soda lime glass is also preferable. Soda-lime glass is generally a glass _{composition, SiO 2 65~75%, Al 2} O 3 0~3%, CaO 5~15%, 0~15% MgO, Na 2 O 10~20%, K ₂ O 0 to 3%, Fe ₂ O ₃ 0 to 3% are contained.

The vehicle laminated glass of the present invention, the density of the glass sheet (inner glass plate and / or outer glass plate) is 2.6 g / cm ³ or less, 2.55 g / cm ³ or less, 2.50 g / cm ³ or less, 2 .48g / cm ³ or less, 2.46 g / cm ³ or less, particularly preferably 2.45 g / cm ³ or less. When the density is too large, it is difficult to reduce the weight of the glass plate, and it is difficult to reduce the weight of the laminated glass. The “density” can be measured by the Archimedes method.

The thermal expansion coefficient in the temperature range of 25 to 380 ° C. of the glass plate (inner glass plate and / or outer glass plate) is preferably 100 × 10 ⁻⁷ / ° C. or lower, 95 × 10 ⁻⁷ / ° C. or lower, 90 × 10 ^{It is −7} / ° C. or lower, particularly 85 × 10 ⁻⁷ / ° C. or lower. When the thermal expansion coefficient of the glass plate is too high, it becomes difficult to match the thermal expansion coefficient of the organic resin intermediate layer, and the glass plate and the organic resin intermediate layer are easily peeled off. The “thermal expansion coefficient in the temperature range of 25 to 380 ° C.” is an average value measured with a dilatometer.

The liquidus temperature of the glass plate (inner glass plate and / or outer glass plate) is preferably 1200 ° C. or lower, 1150 ° C. or lower, 1100 ° C. or lower, 1080 ° C. or lower, 1050 ° C. or lower, 1020 ° C. or lower, particularly 1000 ° C. or lower. is there. Liquidus viscosity, preferably of ¹⁰ 4.0 dPa · s or ^{more, 10} 4.4 dPa · s or ^{more, 10} 4.8 dPa · s or ^{more, 10} 5.0 dPa · s or ^more, 10 5.3 dPa · s Above, 10 ^5.5 dPa · s or more, 10 ^5.7 dPa · s or more, 10 ^5.8 dPa · s or more, particularly 10 ^6.0 dPa · s or more. If the liquidus temperature and the liquidus viscosity are out of the above ranges, the glass tends to devitrify during molding. Note that the “liquid phase temperature” is obtained by passing the glass powder that passes through a standard mesh of 30 mesh (a sieve opening of 500 μm) and remains in a mesh of 50 mesh (a sieve opening of 300 μm) into a platinum boat, and then in a temperature gradient furnace for 24 hours. This is a value obtained by measuring the temperature at which crystals are deposited. “Liquid phase viscosity” refers to a value obtained by measuring the viscosity of glass at the liquid phase temperature by a platinum ball pulling method.

  The Young's modulus of the glass plate (inner glass plate and / or outer glass plate) is preferably 65 GPa or more, 69 GPa or more, 71 GPa or more, 75 GPa or more, particularly 77 GPa or more. When the Young's modulus is too low, the glass plate is easily bent and the glass plate is easily deformed by its own weight. The “Young's modulus” can be measured by a resonance method or the like.

  In the laminated glass for vehicles of the present invention, the thickness of the organic resin intermediate layer is preferably 0.1 to 2 mm, 0.3 to 1.5 mm, 0.5 to 1.2 mm, particularly 0.6 to 0.9 mm. is there. If the thickness of the organic resin intermediate layer is too small, the impact absorbability tends to be lowered, and the sticking property tends to vary, so that the glass plate and the organic resin intermediate layer are easily peeled off. On the other hand, when the thickness of the organic resin intermediate layer is too large, the visibility of the laminated glass tends to be lowered.

  Various materials can be used as the organic resin intermediate layer, for example, polyethylene (PE), ethylene vinyl acetate copolymer (EVA), polypropylene (PP), polystyrene (PS), methacrylic resin (PMA), polychlorinated. Vinyl (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), polyvinyl formal (PVF), polyvinyl alcohol (PVAL), vinyl acetate resin (PVAc), ionomer (IO), polymethylpentene (TPX), vinylidene chloride (PVDC), polysulfone (PSF), polyfluoride Used as vinylidene (PVDF), methacryl-styrene copolymer resin (MS), polyarate (PAR), polyallylsulfone (PASF), polybutadiene (BR), polyethersulfone (PESF), or polyetheretherketone (PEEK) Is possible. Among these, EVA and PVB are preferable from the viewpoint of transparency and adhesiveness, and PVB is particularly preferable because it can provide sound insulation.

  A colorant may be added to the organic resin intermediate layer, or an absorber that absorbs light of a specific wavelength such as infrared rays or ultraviolet rays may be added.

  The laminated glass for vehicles of the present invention can be produced as follows.

  First, the glass raw material prepared so as to have a predetermined glass composition is put into a continuous melting furnace, heated and melted at 1500 to 1700 ° C., clarified and stirred, then supplied to a molding device and molded into a flat plate shape, A glass plate can be produced by slow cooling.

  As a method of forming into a flat plate shape, it is preferable to employ an overflow down draw method. The overflow downdraw method is a method in which a high-quality glass plate can be produced in a large amount and a large glass plate can be easily produced while the surface is unpolished. If the surface is unpolished, the manufacturing cost of the glass plate can be reduced.

  In addition to the overflow downdraw method, it is also preferable to form the glass plate by a float method. The float method is a method capable of producing a large glass plate at low cost.

  Next, the obtained glass plate is subjected to curved surface processing as necessary. Various methods can be employed as a method of processing the curved surface. In particular, a method of press-molding a glass plate with a mold is preferable, and it is more preferable to pass through a heat treatment furnace with the glass plate sandwiched between molds having a predetermined shape. In this way, the dimensional accuracy of the curved surface shape can be increased. Also preferred is a method of softening and deforming the glass plate by its own weight along the shape of the mold by heat-treating a part or the whole of the glass plate after arranging the glass plate on the mold having a predetermined shape. If it does in this way, the efficiency of curved surface processing can be raised.

Subsequently, the glass plate after the curved surface processing is chemically strengthened to obtain an inner glass plate, and is physically strengthened to obtain an outer glass plate. The conditions for the chemical strengthening treatment are not particularly limited, and the optimum conditions may be selected in consideration of the viscosity characteristics, application, thickness, internal tensile stress, dimensional change, and the like of the glass. For example, it can be carried out by immersing in KNO ₃ molten salt at 390 to 480 ° C. for 1 to 8 hours. In particular, when K ions in the KNO ₃ molten salt are ion-exchanged with Na components in the glass, a compressive stress layer can be efficiently formed on the glass surface. Moreover, although the conditions of a physical reinforcement | strengthening process are not specifically limited, After heating to the temperature of the softening point vicinity of a glass plate, it is preferable to quench rapidly with an air jet. The physical strengthening treatment may be performed in a separate heat treatment step, but from the viewpoint of production efficiency, it is preferably performed by rapidly cooling the glass after the curved surface processing.

  Furthermore, the two glass plates after the tempering treatment are laminated and integrated with an organic resin intermediate layer to obtain a laminated glass. As a method of stacking and integrating, a method of curing an organic resin after injecting an organic resin between two glass plates, a method of placing an organic resin sheet between two glass plates, and a method of performing pressure heat treatment (thermocompression bonding), etc. However, the latter method is preferable because stacking and integration are easier.

  After obtaining the laminated glass, it is preferable to remove the organic resin intermediate layer protruding from the end face of the laminated glass, and chamfering may be performed to prevent breakage from the end face of the laminated glass. Moreover, after obtaining the laminated glass, a hard coat film or an infrared reflective film may be formed on the surface of the inner glass plate or the outer glass plate.

  Hereinafter, based on an Example, this invention is demonstrated in detail. The following examples are merely illustrative. The present invention is not limited to the following examples.

  Table 1 shows the glass composition and glass characteristics of the inner glass plate (Sample Nos. 1 to 5).

  Each sample was produced as follows. First, to prepare the glass composition in the table, each glass raw material was prepared, melted, clarified and stirred to obtain a homogeneous glass, then formed into a plate shape by the overflow down draw method, A glass plate was obtained. Various characteristics were evaluated for each obtained sample.

  The density ρ is a value measured by the well-known Archimedes method.

  The thermal expansion coefficient α is a value obtained by measuring an average thermal expansion coefficient in a temperature range of 25 to 380 ° C. using a dilatometer.

  The Young's modulus E is a value measured by a known resonance method.

  The liquid phase temperature TL passes through a standard sieve 30 mesh (a sieve opening of 500 μm), and glass powder remaining in a 50 mesh (a sieve opening of 300 μm) is put in a platinum boat, and then held in a temperature gradient furnace for 24 hours. This is a value obtained by measuring the temperature at which crystals are deposited.

The liquidus viscosity log ₁₀ η _TL is a value obtained by measuring the viscosity of the glass at the liquidus temperature by a platinum ball pulling method.

  The crack occurrence rate was measured as follows. First, it was kept in an electric furnace kept at a temperature of 200 ° C. for 1 hour to make the surface moisture state constant. Then, in a constant temperature and humidity chamber maintained at a humidity of 30% and a temperature of 25 ° C., a Vickers indenter set at a load of 800 gf was driven into the glass surface for 15 seconds, and the number of cracks generated from four corners of the indentation after 15 seconds. Counted (maximum 4 per indentation). Thus, after indenting the indenter 50 times and determining the total number of cracks generated, the total number of cracks generated was calculated by the formula (total number of cracks generated / 200) × 100.

  Next, each sample is passed through a heat treatment furnace in a state where each sample is sandwiched between molds of a predetermined shape, so that the entire plate width direction is curved in an arc shape and the entire length direction is an arc shape. Curved to a curved shape.

Subsequently, after optical polishing was performed on both surfaces of each sample, chemical strengthening treatment was performed by immersing in KNO ₃ molten salt (new KNO ₃ molten salt) at 430 ° C. for 4 hours. After the chemical strengthening treatment, the surface of each sample was washed to obtain an inner glass plate. Subsequently, the compressive stress value CS and the stress depth DOL of the compressive stress layer on the surface were calculated from the number of interference fringes observed using a surface stress meter (FSM-6000 manufactured by Orihara Seisakusho Co., Ltd.). In the calculation, the refractive index of each sample was 1.5, and the optical elastic constant was 30 [(nm / cm) / MPa].

  Furthermore, while preparing the glass plate (plate thickness 1.5mm) which consists of soda-lime glass which has the same size as the said inner side glass plate, it curved-surface-processed by the method similar to the case of the said inner side glass plate about this glass plate. Thereafter, the outer glass plate was obtained by quenching and physical strengthening treatment. When CS was calculated by the above method for the obtained outer glass plate, CS was 50 MPa.

  Finally, using an organic resin intermediate layer (PVB) having a thickness of 0.7 mm, the inner glass plate (Sample Nos. 1 to 4) and the outer glass plate are laminated and integrated by pressure and heat treatment to obtain a curved surface shape. A laminated glass having was obtained. It is considered that these laminated glasses can achieve both high strength and thinning, and can effectively avoid the risk of human body damage when broken.

  The laminated glass for vehicles of the present invention is suitable for a windshield of an automobile, but is also suitable for a rear glass, a door glass, and a roof glass of an automobile.

DESCRIPTION OF SYMBOLS 10 Vehicle laminated glass 11 Inner glass plate 12 Outer glass plate 13 Organic resin intermediate layer

Claims (9)

In the laminated glass for vehicles in which the inner glass plate and the outer glass plate are integrated via the organic resin intermediate layer,
The inner glass plate is chemically strengthened glass having a compressive stress layer on the surface,
The laminated glass for vehicles, wherein the outer glass plate is a physically tempered glass having a compressive stress layer on the surface.   The laminated glass for a vehicle according to claim 1, which has a curved surface shape that is three-dimensionally curved.   The laminated glass for vehicles according to claim 1 or 2, wherein the inner glass plate is alkali aluminosilicate glass and the thickness thereof is 1.5 mm or less. The inner glass plate is, as a glass composition, in mass%, SiO ₂ 40-80%, Al ₂ O ₃ 1-30%, B ₂ O ₃ 0-10%, Na ₂ O 5-20%, K ₂ O 0. The laminated glass for vehicles according to any one of claims 1 to 3, comprising -5%.   The laminated glass for vehicles according to any one of claims 1 to 4, wherein a compressive stress value of a compressive stress layer of the inner glass plate is 300 MPa or more and a stress depth is 5 µm or more.   The laminated glass for vehicles according to any one of claims 1 to 5, wherein a crack occurrence rate of the inner glass plate before chemical strengthening treatment when a load of 800 gf is applied with a Vickers indenter is 80% or less.   The laminated glass for vehicles according to any one of claims 1 to 6, wherein the outer glass plate is alkali aluminosilicate glass or soda lime glass, and the thickness thereof is 1.0 to 4.0 mm.   The laminated glass for vehicles according to any one of claims 1 to 7, wherein the organic resin layer is composed of an ethylene vinyl acetate copolymer or polyvinyl butyral.   The laminated glass for vehicles according to any one of claims 1 to 8, which is used for a windshield of an automobile.

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