Laminated glass for vehicles and its applications

Abstract

A laminated vehicle glass includes an outer glass sheet having a first surface facing the exterior of the vehicle and a second surface facing the interior of the vehicle, an inner glass sheet having a third surface facing the exterior of the vehicle and a fourth surface facing the interior of the vehicle, and an interlayer bonding the second and third surfaces together, with an infrared reflective film disposed between the outer and inner glass sheets and a low-emissivity film disposed on the fourth surface, the laminated vehicle glass having a specular coefficient α calculated by the formula α = RL / TL2 of 15 or less (where RL is the visible light reflectance of the laminated vehicle glass measured from the interior of the vehicle, and TL is the visible light transmittance of the laminated vehicle glass). When used as a skylight glass in a vehicle roof, the laminated vehicle glass satisfies the need to eliminate the use of sunroof curtains and effectively improves the specular reflection effect on the interior of the vehicle, improving the user experience and protecting the privacy of occupants.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority from a Chinese patent application filed with the China Patent Office on November 24, 2022, bearing application number 202211479714.6 and titled "Laminated glass for vehicles and its applications," the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to laminated glass for vehicles and its applications, and belongs to the technical field of glass for vehicles. [Background technology]

[0003] The panoramic canopy glass for sunroof-free automobiles, used in the prior art such as US20040219368A1 and CN101400515A, generally achieves heat insulation and heat retention functions by using a heat-reflecting metal film and / or a heat-absorbing interlayer and / or a low-emissivity film. The heat-absorbing interlayer generally has low visible light transmittance, so that sunlight passing through the roof and entering the vehicle interior can be prevented from causing adverse effects such as glare and dizziness.

[0004] At the same time, because vehicle laminated glass generally does not have a sunroof curtain and its visible light reflectance generally exceeds 8%, when used as a rooftop glass for a vehicle, the specular reflection of passengers and objects inside the vehicle (e.g., center console displays or other electronic device displays) is formed in the rooftop glass, causing visual interference and discomfort to passengers, especially rear passengers. Furthermore, as the size of the rooftop glass increases and the visible light transmittance decreases, the reflection becomes more pronounced, for example, in the panoramic rooftop glass or panoramic canopy glass of an electric vehicle. When passengers inside the vehicle use electronic devices such as mobile phones, the contents of the electronic device are clearly displayed on the rooftop glass, allowing other passengers to observe, potentially resulting in a breach of privacy. Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, providing a laminated glass for vehicles and its application to realize improved specular reflection without a sunroof curtain has become a technical problem that needs to be solved urgently in this field.

[0006] One object of the present invention is to provide a laminated vehicle glass to achieve improved specular reflection without a sunroof curtain.

[0007] Another object of the present invention is to provide use of the above laminated glass for vehicles as a roof window glass, side window glass or rear window glass of a vehicle. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a laminated glass for a vehicle, comprising an outer glass sheet having a first surface facing the exterior of the vehicle and a second surface facing the interior of the vehicle, an inner glass sheet having a third surface facing the exterior of the vehicle and a fourth surface facing the interior of the vehicle, and an interlayer film bonding the second surface and the third surface together, wherein an infrared reflective film is provided between the outer glass sheet and the inner glass sheet, and a low emissivity film is provided on the fourth surface; α=RL / TL 2 The present invention provides a laminated glass for vehicles having a specular coefficient α calculated by the following formula (where RL is the visible light reflectance of the laminated glass for vehicles measured from the inside of the vehicle, and TL is the visible light transmittance of the laminated glass for vehicles) of 15 or less. Specific examples of the specular coefficient α include 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15.

[0009] In one embodiment of the laminated glass for vehicles of the present invention, the specular coefficient α of the laminated glass for vehicles is 3-10.

[0010] In one embodiment of the above-mentioned laminated glass for vehicles of the present invention, an edge region of the second surface is covered with a first dark-tinted shielding layer, and / or an edge region of the third surface or the fourth surface is covered with a second dark-tinted shielding layer, and a width of the second dark-tinted shielding layer is greater than a width of the first dark-tinted shielding layer.

[0011] In one embodiment of the laminated glass for vehicles of the present invention, the thickness range of each of the first dark colored shielding layer and the second dark colored shielding layer is 10 μm to 22 μm, and preferably 10 μm to 15 μm.

[0012] In the present invention, the width of the second dark color shielding layer is greater than the width of the first dark color shielding layer. In this case, it is possible to prevent the print boundary from being visible inside the vehicle. In one embodiment of the above-mentioned laminated glass for vehicles of the present invention, the difference in width between the second dark color shielding layer and the first dark color shielding layer is 3 mm to 10 mm, and preferably 5 mm.

[0013] In some embodiments of the present invention, the first and second dark color blocking layers may be made of black ceramic ink, which is a conventional material that is commercially available and includes glass frit (with a content of more than 60 wt%) and a coloring material.

[0014] In some embodiments of the present invention, the first and second dark color blocking layers are both manufactured by screen printing or inkjet printing.

[0015] In one embodiment of the laminated glass for vehicles of the present invention, the outer glass sheet is a transparent glass having a visible light transmittance of ≧80% and a thickness of 1.8 mm to 4.2 mm.

[0016] In one embodiment of the laminated glass for vehicles of the present invention, the inner glass sheet is a clear glass or a green glass having a visible light transmittance of ≧80% and a thickness of 0.7 mm to 2.1 mm.

[0017] In one embodiment of the laminated glass for vehicles of the present invention, the visible light transmittance of the inner glass sheet provided with the low-emissivity film is 50% to 70%.

[0018] In one embodiment of the laminated glass for vehicles of the present invention, the inner glass sheet provided with the low-emissivity film has a glass thickness of α1=RL 内 / TL 内 2 The specular coefficient α1 calculated by the formula is 0.1 or less (however, RL 内 is the visible light reflectance of the inner glass sheet with the low-emissivity coating measured from the side closest to the low-emissivity coating, and TL 内 is the visible light transmittance of the inner glass sheet provided with the low-emissivity film.) Here, specific examples of the specular coefficient α1 include 0.05, 0.06, 0.07, 0.08, 0.09, and 0.1.

[0019] In one embodiment of the laminated glass for vehicles of the present invention, the visible light transmittance of the interlayer film is 1% to 20%, preferably 2% to 10%. More preferably, the interlayer is a colored thermoplastic polymer film, the material of which includes PVB, EVA, SGP or PU.

[0020] In the present invention, the thickness of the interlayer is not specifically limited and may be reasonably adjusted according to the actual conditions of the site. For example, in some embodiments of the present invention, the thickness of the interlayer may be generally 0.38 mm to 1.63 mm, and preferably 0.76 mm to 1.25 mm.

[0021] In one embodiment of the above-mentioned laminated glass for vehicles of the present invention, the infrared reflective film includes at least one metal layer and at least two first dielectric layers, and each metal layer is located between two adjacent first dielectric layers.

[0022] In the present invention, the thickness of the infrared reflective film is not specifically limited and can be reasonably adjusted according to the actual situation at the site. For example, in some embodiments of the present invention, the thickness of the infrared reflective film may be 100 nm to 500 nm.

[0023] In the present invention, when the edge region of the second surface of the outer glass sheet is covered with a first dark color shielding layer, an infrared reflective film is provided between the first dark color shielding layer and the interlayer film.

[0024] In one embodiment of the above-mentioned laminated glass for vehicles of the present invention, the low-emissivity film includes at least one transparent conductive oxide layer and at least two second dielectric layers, and each transparent conductive oxide layer is located between two adjacent second dielectric layers.

[0025] In one embodiment of the above-mentioned laminated glass for vehicles of the present invention, the low-emissivity film further comprises at least one visible light barrier layer in direct contact with the transparent conductive oxide layer.

[0026] In the present invention, the thickness of the low-emissivity film is not specifically limited and can be reasonably adjusted according to the actual situation at the site. For example, in some embodiments of the present invention, the thickness of the low-emissivity film may be 100 nm to 500 nm.

[0027] In one embodiment of the above laminated glass for vehicles of the present invention, the emissivity of the low-emissivity film is 0.25 or less and the surface resistance is 23 ohm / m 2 or less, and the reflected hue of the inner glass sheet provided with the low-emissivity coating, measured from the side closest to the low-emissivity coating, is −10≦a≦2, −5≦b≦5 in the Lab system.

[0028] In one embodiment of the laminated glass for vehicles of the present invention, the laminated glass for vehicles has a visible light transmittance TL of 0.5% to 10%. The laminated glass for vehicles has a visible light reflectance RL measured from the inside of the vehicle of 6% or less, preferably 4% or less, more preferably 2% or less, and even more preferably 1% or less. The laminated glass for vehicles has a total solar transmittance of 20% or less.

[0029] The present invention also provides an application of the above laminated glass for vehicles as a roof window glass, side window glass or rear window glass of a vehicle.

[0030] In one embodiment of the above application of the present invention, the vehicle may be, for example, a car. [Effects of the Invention]

[0031] When the vehicle laminated glass provided by the present invention is used as a roof glass, i.e., a skylight glass, the use of shading devices such as sunroof curtains or shading cloths can be dispensed with, and the formation of obvious reflections of passengers and objects inside the vehicle due to specular reflection on the skylight glass can be reduced or eliminated, avoiding visual interference for passengers, especially rear passengers, and effectively improving the specular reflection effect on the interior of the vehicle, improving the user experience and protecting the privacy of passengers.

[0032] In order to more clearly explain the embodiments of the present invention or the technical solutions in the prior art, the following will briefly describe the drawings used to describe the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings based on these drawings without any creative work. [Brief explanation of the drawings]

[0033] [Figure 1] Schematic diagram of the structure of a laminated glass for vehicles according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0034] It should be noted that the term "comprises" and any variations thereof in the present specification, claims, and drawings are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, apparatus, or composition that comprises a series of steps, units, or components is not necessarily limited to those steps, units, or components explicitly recited, but may include other steps, units, or components that are not explicitly recited or that are inherent to the process, method, product, apparatus, or composition.

[0035] The "ranges" disclosed herein are given in the form of lower and upper limits. There may be one or more lower and upper limits. A given range is defined by selecting one lower limit and one upper limit. The selected lower and upper limits define the boundaries of that particular range. All ranges defined in this manner are combinable, i.e., any lower limit and any upper limit may be combined to form a single range. For example, if ranges of 60 to 120 and 80 to 110 are recited for a particular parameter, ranges of 60 to 110 and 80 to 120 are also contemplated. Furthermore, if the recited minimum range values ​​are 1 and 2 and the recited maximum range values ​​are 3, 4, and 5, ranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5 are contemplated.

[0036] In the present invention, unless otherwise specified, the numerical range "a to b" indicates an abbreviation for any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0 to 5" indicates that all real numbers between "0 and 5" are listed in the present invention, and "0 to 5" is merely an abbreviation for this combination of numerical values.

[0037] In the present invention, unless otherwise specified, all embodiments and preferred embodiments of the present invention can be combined with each other to form new technical solutions.

[0038] In the present invention, unless otherwise specified, all the constituent features and preferred constituent features of the present invention can be combined with each other to form a new technical solution.

[0039] In order to clarify the objectives, technical solutions, and advantages of the present invention, the present invention will be described in more detail below with reference to tables, drawings, and examples. The examples described below are only some of the examples of the present invention, but are not all examples, and are intended to illustrate the present invention and not to limit the scope of the present invention. All other examples obtained by those skilled in the art based on the examples of the present invention without creative effort fall within the scope of the present invention. Unless specific conditions are specified in the examples, they are carried out according to standard conditions or conditions suggested by the manufacturer. Unless the manufacturer is specified, the reagents or equipment used are all commercially available standard products.

[0040] In the present invention, the infrared reflective film 3 can reduce the total solar transmittance of the vehicle laminated glass by reflecting infrared rays in sunlight. The infrared reflective film 3 is provided between the outer glass sheet 1 and the inner glass sheet 5, and specifically, may be provided on the second surface 12 of the outer glass sheet 1, on the third surface 51 of the inner glass sheet 5, or on a thermoplastic film such as PET. The thermoplastic film provided with the infrared reflective film 3 is sandwiched between the second surface 12 and the third surface 51.

[0041] The infrared reflective film 3 includes at least one metal layer and at least two first dielectric layers, with each metal layer positioned between two adjacent first dielectric layers. The metal layers can be made of metals or metal alloys such as silver (Ag), gold (Au), copper (Cu), aluminum (Al), and platinum (Pt). In the present invention, silver metal or a silver alloy is preferred. The silver alloy is preferably an alloy of silver with at least one of gold, aluminum, copper, and platinum. Depending on the actual application, the number of metal layers in the infrared reflective film 3 can be, for example, two, three, four, five, or more. For example, silver metal or a silver alloy can be used to make a two-silver-layer infrared reflective film, a three-silver-layer infrared reflective film, a four-silver-layer infrared reflective film, or a five-silver-layer infrared reflective film. The material of the first dielectric layer may be at least one selected from oxides of Zn, Mg, Sn, Ti, Nb, Zr, Ni, In, Al, Ce, W, Mo, Sb, and Bi, or nitrides, nitrogen oxides, and mixtures thereof of Si, Al, Zr, Y, Ce, and La. For example, zinc stannate, magnesium-doped zinc stannate, zinc oxide, magnesium-doped zinc oxide, zirconium-doped zinc oxide, niobium oxide, bismuth oxide, aluminum-doped zinc oxide, zirconium oxide, titanium oxide, and titanium peroxide.

[0042] Here, the metal layer and the first dielectric layer may each be formed by a magnetron sputtering process. The thickness of each metal layer is 4 nm to 20 nm. By optimizing the materials and thicknesses of the metal layer and the first dielectric layer, the infrared reflective film 3 can withstand subsequent high-temperature heat treatment or other bending processes, and the optical and mechanical properties of the resulting laminated glass for vehicles can all meet the standards for use with vehicle glass.

[0043] In the present invention, the low-emissivity film 6 is provided on the fourth surface 52 of the inner glass sheet 5 to reduce the emissivity of the vehicle laminated glass. The emissivity of the low-emissivity film 6 is preferably 0.25 or less, more preferably 0.20 or less. The low-emissivity film 6 includes at least one transparent conductive oxide (TCO) layer. The transparent conductive oxide layer may be made of at least one material selected from the group consisting of doped zinc oxide, indium tin oxide (ITO), and fluorine-doped tin dioxide (FTO). The doped zinc oxide is zinc oxide doped with one or more elements such as aluminum, tungsten, hafnium, gallium, yttrium, niobium, and neodymium. Specifically, the doped zinc oxide may be at least one of aluminum-doped zinc oxide (AZO), yttrium-doped zinc oxide (YZO), hafnium- and aluminum-doped zinc oxide (HAZO), tungsten- and aluminum-doped zinc oxide (W-AZO), and gallium-doped zinc oxide (GZO).

[0044] The total thickness of the transparent conductive oxide layers in the low-emissivity film 6 is 50 nm to 300 nm. The low-emissivity film 6 further includes at least two second dielectric layers, with each transparent conductive oxide layer positioned between two adjacent second dielectric layers. The transparent conductive oxide layers and the second dielectric layers may each be formed by a magnetron sputtering process. By optimizing the materials and thicknesses of the transparent conductive oxide layers and the second dielectric layers, the low-emissivity film 6 can withstand subsequent high-temperature heat treatment or other bending processes, and the optical and mechanical performance of the resulting laminated glass for vehicles can meet the standards for use with glass. The low-emissivity film 6 also achieves a reflection-reducing effect. In this way, the formation of obvious reflections of passengers and objects inside the vehicle due to specular reflection on the rooflight glass can be reduced or eliminated, avoiding visual interference for passengers, especially rear passengers, and improving the user experience. Preferably, the material of the second dielectric layer is a nitride, oxide or oxynitride of at least one element selected from Zn, Sn, Ti, Si, Al, Mg and Zr.

[0045] The low-emissivity film 6 further includes at least one visible light barrier layer. The thickness of the visible light barrier layer is 4 nm to 20 nm. The visible light barrier layer is at least one selected from the group consisting of nickel-chromium alloy (NiCr), nickel-aluminum alloy (NiAl), nickel-silicon alloy (NiSi), metallic chromium (Cr), titanium nitride (TiN), niobium nitride (NbN), and titanium-molybdenum alloy (MoTi). The addition of the visible light barrier layer to the low-emissivity film 6 allows the inner glass sheet 5 to be made of clear glass or green glass with a visible light transmittance of 80% or more, and further achieves a specular coefficient α of 15 for the vehicle laminated glass. This is advantageous in reducing or eliminating the formation of obvious reflections of passengers and objects inside the vehicle due to specular reflection in the rooflight glass, avoiding visual interference with passengers, especially rear passengers, and improving the user experience.

[0046] <Examples 1 to 3 and Comparative Examples 1 to 3> Example 1 This embodiment provides laminated glass for vehicles, the structural schematic of which is shown in Figure 1. As can be seen from Figure 1, the laminated glass for vehicles includes an outer glass sheet 1 having a first surface 11 facing the exterior of the vehicle and a second surface 12 facing the interior of the vehicle, an inner glass sheet 5 having a third surface 51 facing the exterior of the vehicle and a fourth surface 52 facing the interior of the vehicle, and an interlayer 4 bonding the outer glass sheet 1 and the inner glass sheet 5 together. An infrared reflective film 3 is provided on the second surface 12 of the outer glass sheet 1, and a low-emissivity film 6 is provided on the fourth surface of the inner glass sheet 5.

[0047] The edge region of the second surface 12 of the outer glass sheet 1 is covered with a first dark color shielding layer 2, and the edge region of the fourth surface 52 of the inner glass sheet 5 is covered with a second dark color shielding layer 7. The width of the second dark color shielding layer 7 is greater than the width of the first dark color shielding layer 2. The material of the first dark color shielding layer 2 and the second dark color shielding layer 7 is black ceramic ink. The first dark color shielding layer 2 may be printed directly on the second surface 12 by a process such as screen printing, or may be printed directly on the infrared reflective film 3. The second dark color shielding layer 7 may be printed directly on the fourth surface 52 by a process such as screen printing, or may be printed directly on the low-emissivity film 6.

[0048] In this embodiment, the outer glass sheet 1 is a transparent glass sheet having a thickness of 2.1 mm and a visible light transmittance of 88%, the inner glass sheet 5 is a transparent glass sheet having a thickness of 2.1 mm and a visible light transmittance of 88%, and the interlayer film 4 is a gray PVB film having a visible light transmittance of 8%.

[0049] The infrared reflective film 3 is a double-silver layer infrared reflective film. Specifically, the infrared reflective film 3 is composed of transparent glass / SiO2 (15 nm) / ZnSnOx (32 nm) / AZO (9 nm) / Ag (9.6 nm) / AZO (12.3 nm) / ZnSnOx (46.3 nm) / AZO (12 nm) / Ag (11.8 nm) / AZO (11 nm) / ZnSnOx (25 nm) / Si3N4 (11 nm). The Ag layer is the metal layer, and the others are first dielectric layers.

[0050] The low-emissivity film 6 includes a visible light barrier layer. Specifically, the low-emissivity film 6 is made of transparent glass / Si3N4 (5 nm) / ITO (160 nm) / NiCr (4 nm) / Si3N4 (23 nm) / SiO2 (60 nm) / Si3N4 (5 nm). ITO is a transparent conductive oxide layer, NiCr is a visible light barrier layer, and the other layers are second dielectric layers.

[0051] Example 2 The laminated glass for vehicles according to this example differs from the laminated glass for vehicles according to Example 1 only in the following points. The low-emissivity film 6 does not include a visible light barrier layer. Specifically, the low-emissivity film 6 is made of transparent glass / Si3N4 (5 nm) / ITO (118 nm) / Si3N4 (8 nm) / SiO2 (180 nm). The ITO is a transparent conductive oxide layer, and the other layers are second dielectric layers.

[0052] Example 3 The laminated glass for vehicles according to this example differs from the laminated glass for vehicles according to Example 1 only in the following points. The interlayer 4 is gray PVB, and its visible light transmittance is 5%.

[0053] (Comparative Example 1) The laminated glass for vehicles according to this comparative example differs from the laminated glass for vehicles according to Example 1 only in the following points. The fourth surface 52 of the inner glass sheet 5 was not provided with the low-emissivity coating 6 .

[0054] Comparative Example 2 The laminated glass for vehicles according to this comparative example differs from the laminated glass for vehicles according to Example 1 only in the following points. The second surface 12 of the outer glass sheet 1 was not provided with an infrared reflective coating 3. The outer glass sheet 1 was gray glass having a thickness of 2.1 mm and a visible light transmittance of 40%, the inner glass sheet 5 was gray glass having a thickness of 2.1 mm and a visible light transmittance of 40%, and the interlayer 4 was gray PVB having a visible light transmittance of 18%.

[0055] (Comparative Example 3) The laminated glass for vehicles according to this comparative example differs from the laminated glass for vehicles according to Example 1 only in the following points. The low-emissivity film 6 is a single FTO layer formed by an online chemical vapor deposition (CVD) process using a float method.

[0056] (Performance test example 1) Using the automotive glass manufacturing process, laminated vehicle glasses according to Examples 1 to 3 and laminated vehicle glasses according to Comparative Examples 1 to 3 were obtained. Then, the visible light transmittance (TL), visible light reflectance (RL), total solar transmittance (TTS), etc. were measured for each glass, and the specular coefficient (α) was calculated. The correlation test results and calculation results are shown in Table 1.

[0057] The visible light transmittance (TL) was calculated based on ISO9050 by measuring the visible light transmittance of the laminated glass for vehicles in the wavelength range of 380 nm to 780 nm. The visible light reflectance (RL) was calculated based on ISO9050 by measuring the visible light reflectance of the laminated glass for vehicles in the wavelength range of 380 nm to 780 nm from the inside of the vehicle. The total solar transmittance (TTS) was calculated based on ISO9050 by measuring the total solar transmittance of laminated glass for vehicles in the wavelength range of 300 nm to 2500 nm. The specular coefficient (α) is α=RL / TL 2 was calculated from the formula:

[0058] Table 1 shows the test results and calculation results for Examples 1 to 3 and Comparative Examples 1 to 3.

[0059] [Table 1]

[0060] As can be seen from Table 1 above, the laminated glass for vehicles according to Examples 1 to 3 of the present invention have a visible light transmittance TL of 0.5% to 10%, a visible light reflectance of 3% or less, a specular coefficient of 3 to 10, and a total solar transmittance of 20% or less. As can be seen from this, when used as a roof window glass for a vehicle roof, the laminated glass for vehicles according to Examples 1 to 3 is better than the laminated glass for vehicles according to Comparative Examples 1 to 3 in satisfying the need to dispense with a sunroof curtain, and is able to reduce or eliminate the formation of clear reflections of passengers and objects inside the vehicle due to specular reflection in the roof window glass, thereby avoiding visual interference for passengers, particularly passengers in the rear, effectively improving the specular reflection effect on the interior of the vehicle, improving the user experience, and protecting the privacy of passengers.

[0061] The laminated glass for vehicles according to Comparative Example 1 was not provided with a low-emissivity film 6, and therefore had an emissivity of approximately 0.9, did not have the effect of insulating in summer or keeping warm in winter, and not only did its total solar transmittance exceed 20%, but its specular coefficient was also greater than 15. Compared with Examples 1 to 3, the laminated glass for vehicles according to Comparative Example 1 did not have low-emissivity performance, had poor insulating effect, and exhibited strong specular reflection, and could not satisfy the need for not using a sunroof curtain.

[0062] The laminated glass for vehicles in Comparative Example 2 was not provided with an infrared reflective film 3, and therefore two sheets of gray glass were used to reduce its total solar transmittance to approximately 20% as much as possible. The visible light transmittance and visible light reflectance met the needs, and the total solar transmittance was close to 20%, but the specular coefficient was greater than 15, resulting in strong specular reflection and failing to meet the need for no sunroof curtain.

[0063] The laminated glass for vehicles in Comparative Example 3 met the requirements for visible light transmittance, specular coefficient, and total solar transmittance, but its visible light reflectance exceeded 8%, so it could not satisfy the requirement for not using a sunroof curtain.

[0064] <Examples 4 to 6 and Comparative Examples 4 to 6> Example 4 This embodiment provides laminated glass for vehicles, the structural schematic of which is shown in Figure 1. As can be seen from Figure 1, the laminated glass for vehicles includes an outer glass sheet 1 having a first surface 11 facing the exterior of the vehicle and a second surface 12 facing the interior of the vehicle, an inner glass sheet 5 having a third surface 51 facing the exterior of the vehicle and a fourth surface 52 facing the interior of the vehicle, and an interlayer 4 bonding the outer glass sheet 1 and the inner glass sheet 5 together. An infrared reflective film 3 is provided on the second surface 12 of the outer glass sheet 1, and a low-emissivity film 6 is provided on the fourth surface 52 of the inner glass sheet 5.

[0065] The edge region of the second surface 12 of the outer glass sheet 1 is covered with a first dark color shielding layer 2, and the edge region of the fourth surface 52 of the inner glass sheet 5 is covered with a second dark color shielding layer 7. The width of the second dark color shielding layer 7 is greater than the width of the first dark color shielding layer 2. The material of the first dark color shielding layer 2 and the second dark color shielding layer 7 is black ceramic ink. The first dark color shielding layer 2 may be printed directly on the second surface 12 by a process such as screen printing, or may be printed directly on the infrared reflective film 3. The second dark color shielding layer 7 may be printed directly on the fourth surface 52 by a process such as screen printing, or may be printed directly on the low-emissivity film 6.

[0066] In this embodiment, the outer glass sheet 1 is a transparent glass sheet having a thickness of 2.1 mm and a visible light transmittance of 88%, the inner glass sheet 5 is a transparent glass sheet having a thickness of 2.1 mm and a visible light transmittance of 88%, and the interlayer film 4 is a gray PVB film having a visible light transmittance of 8%.

[0067] The infrared reflective film 3 is a three-layer silver infrared reflective film. Specifically, the infrared reflective film 3 is composed of transparent glass / SiO2 (13 nm) / ZnSnOx (26.8 nm) / AZO (15.2 nm) / Ag (10.7 nm) / AZO (8.2 nm) / TiO2 (12.6 nm) / ZnSnOx (55.3 nm) / AZO (6.2 nm) / Ag (13.2 nm) / AZO (6 nm) / ZnSnOx (56.3 nm) / AZO (7 nm) / Ag (12.5 nm) / AZO (6.5 nm) / TiO2 (14.9 nm) / ZnSnOx (19 nm) / Si3N4 (11 nm). The Ag layer is the metal layer, and the others are first dielectric layers. The low-emissivity film 6 includes a visible light barrier layer. Specifically, the low-emissivity film 6 is made of transparent glass / Si3N4 (5 nm) / ITO (160 nm) / NiCr (4 nm) / Si3N4 (23 nm) / SiO2 (60 nm) / Si3N4 (5 nm). ITO is a transparent conductive oxide layer, NiCr is a visible light barrier layer, and the other layers are second dielectric layers.

[0068] Example 5 The laminated glass for vehicles according to this example differs from the laminated glass for vehicles according to Example 4 only in the following points. The inner glass sheet 5 is a green glass having a thickness of 2.1 mm and a visible light transmittance of 82%.

[0069] Example 6 The laminated glass for vehicles according to this example differs from the laminated glass for vehicles according to Example 4 only in the following points. The interlayer 4 is gray PVB, and its visible light transmittance is 5%.

[0070] Comparative Example 4 The laminated glass for vehicles according to this comparative example differs from the laminated glass for vehicles according to Example 4 only in the following points. The interlayer 4 is gray PVB, and its visible light transmittance is 2%. The low-emissivity film 6 does not include a visible light barrier layer. Specifically, the low-emissivity film 6 is made of transparent glass / Si3N4 (5 nm) / ITO (118 nm) / Si3N4 (8 nm) / SiO2 (180 nm). The ITO is a transparent conductive oxide layer, and the other layers are second dielectric layers.

[0071] (Comparative Example 5) The laminated glass for vehicles according to this comparative example differs from the laminated glass for vehicles according to Example 4 only in the following points. The inner glass sheet 5 is a green glass having a thickness of 2.1 mm and a visible light transmittance of 82%, and the interlayer 4 is a gray PVB having a visible light transmittance of 2%. The low-emissivity film 6 does not include a visible light barrier layer. Specifically, the low-emissivity film 6 is made of transparent glass / Si3N4 (5 nm) / ITO (118 nm) / Si3N4 (8 nm) / SiO2 (180 nm). The ITO is a transparent conductive oxide layer, and the other layers are second dielectric layers.

[0072] (Comparative Example 6) The laminated glass for vehicles according to this comparative example differs from the laminated glass for vehicles according to Example 4 only in the following points. The inner glass sheet 5 is gray glass having a thickness of 2.1 mm and a visible light transmittance of 40%, and the interlayer 4 is gray PVB having a visible light transmittance of 2%.

[0073] (Performance test example 2) Using the automotive glass manufacturing process, laminated vehicle glasses according to Examples 4 to 6 and laminated vehicle glasses according to Comparative Examples 4 to 6 were obtained. Then, the visible light transmittance (TL), visible light reflectance (RL), total solar transmittance (TTS), etc. were measured for each glass, and the specular coefficient (α) was calculated. The correlation test results and calculation results are shown in Table 2.

[0074] The visible light transmittance (TL) was calculated based on ISO9050 by measuring the visible light transmittance of the laminated glass for vehicles in the wavelength range of 380 nm to 780 nm. The visible light reflectance (RL) was calculated based on ISO9050 by measuring the visible light reflectance of the laminated glass for vehicles in the wavelength range of 380 nm to 780 nm from the inside of the vehicle. The total solar transmittance (TTS) was calculated based on ISO9050 by measuring the total solar transmittance of laminated glass for vehicles in the wavelength range of 300 nm to 2500 nm. The specular coefficient (α) is α=RL / TL 2 was calculated from the formula:

[0075] Table 2 shows the test results and calculation results for Examples 4 to 6 and Comparative Examples 4 to 6.

[0076] [Table 2]

[0077] As can be seen from Table 2 above, the laminated glass for vehicles according to Examples 4 to 6 of the present invention have a visible light transmittance TL of 0.5% to 6%, a visible light reflectance of 2% or less, a specular coefficient of 3 to 10, and a total solar transmittance of 13% or less. As can be seen from this, when used as a roof window glass for a vehicle roof, the laminated glass for vehicles according to Examples 4 to 6 are better able to satisfy the need to dispense with a sunroof curtain than the laminated glass for vehicles according to Comparative Examples 4 to 6, and can reduce or eliminate the formation of clear reflections of passengers and objects inside the vehicle due to specular reflection in the roof window glass, thereby avoiding visual interference for passengers, particularly passengers in the rear, effectively improving the specular reflection effect on the interior of the vehicle, improving the user experience, and protecting the privacy of passengers.

[0078] The visible light transmittance, visible light reflectance, and total solar transmittance of the laminated glass for vehicles according to Comparative Examples 4 to 6 all satisfied the needs. However, when the visible light transmittance TL was reduced so that TL ≦ 2%, the visible light reflectance RL had to be reduced even further, otherwise the specular coefficient would be much greater than 15, and even greater than 100, resulting in very strong specular reflection and failing to meet the need to not use a sunroof curtain. In order to reduce specular reflection to meet the specular coefficient ≦ 15 and meet the need to not use a sunroof curtain, when the visible light transmittance was reduced so that TL ≦ 2%, the visible light reflectance RL needed to be further reduced so that RL ≦ 0.6%.

[0079] The inner glass sheet 5 used in Examples 1, 3, 4, 5, and 6 of the present invention was a clear glass or green glass having a visible light transmittance of 80% or more, and the low-emissivity film 6 further included at least one visible light barrier layer, which was in direct contact with the transparent conductive oxide layer therein.

[0080] The inner glass sheets 5 provided with the low-emissivity films 6 in Examples 1, 3, 4, 5, and 6 were selected and subjected to performance tests. The correlation performance test results are shown in Table 3.

[0081] Visible light transmittance (TL 内 ) was calculated based on ISO9050 by measuring the visible light transmittance of the inner glass sheet 5 provided with the low emissivity film 6 in the wavelength range of 380 nm to 780 nm. Visible light reflectance (RL 内 ) was calculated based on ISO9050 by measuring the visible light reflectance in the wavelength range of 380 nm to 780 nm of the inner glass sheet 5 on which the low-emissivity film 6 was provided, starting from the side closest to the low-emissivity film 6. Total Solar Transmittance (TTS 内 ) was calculated based on ISO9050 by measuring the total solar transmittance of the inner glass sheet 5 provided with the low-emissivity film 6 in the wavelength range of 300 nm to 2500 nm. The specular coefficient (α1) is α1=RL 内 / TL内 2 was calculated from the formula: The emissivity was measured from the side close to the low emissivity film 6 using a Fourier infrared spectrophotometer, and calculations and calibrations were carried out based on the standard EN12898. The surface resistance was measured by a surface resistance meter. The reflected hue was measured from the side closest to the low-emissivity coating 6 and calculated according to the CIE Lab color model, based on a D65 illuminant and a 10° viewing angle, for a 65° incident angle. The a value indicates the red-green value, and the b value indicates the yellow-blue value.

[0082] Table 3 shows the performance test results of the inner glass sheets provided with the low-emissivity films in Example 1 and Examples 3 to 6.

[0083] [Table 3]

[0084] As can be seen from Table 3 above, in the embodiment of the present invention, the transmittance of the inner glass sheet 5 provided with the low emissivity film 6 is 50% to 70%, the reflectance is 4% or less, the specular coefficient is 0.1 or less, the emissivity is 0.25 or less, and the surface resistance is 23 ohm / m 2 When the reflective hue of the inner glass sheet 5 on which the low-emissivity coating 6 was provided was measured from the side closest to the low-emissivity coating 6, the Lab system yielded values ​​of -10≦a≦2 and -5≦b≦5. As can be seen in combination with Tables 1 and 2, the addition of at least one visible light barrier layer to the low-emissivity coating 6 can further improve the visible light transmittance, visible light reflectance, specular coefficient, and total solar transmittance. Furthermore, to achieve the same levels of visible light transmittance, visible light reflectance, and total solar transmittance, there is no need to use an interlayer 4 or gray glass with a lower visible light transmittance. This significantly reduces production costs and difficulty, prevents a specular coefficient of greater than 15, and satisfies the need for a sunroof curtain.

[0085] The above are merely specific examples of the present invention and do not limit the scope of the present invention, so that the replacement of equivalent parts, or equivalent changes and modifications within the scope of protection of the present invention, all fall within the scope of the present invention. In addition, the constituent features of the present invention, the constituent features and technical inventions, and the technical inventions can all be freely combined. [Explanation of symbols]

[0086] 1 outer glass sheet 11 1st surface 12 Second surface 2 1st dark color shielding layer 3. Infrared reflective film 4 Interlayer 5 Inner glass sheet 51 Third surface 52 4th surface 6 Low emissivity film 7 Second dark color shielding layer

Claims

1. a laminated glass for a vehicle, comprising: an outer glass sheet having a first surface facing the exterior of the vehicle and a second surface facing the interior of the vehicle; an inner glass sheet having a third surface facing the exterior of the vehicle and a fourth surface facing the interior of the vehicle; and an interlayer film bonding the second surface and the third surface together, wherein an infrared reflective film is provided between the outer glass sheet and the inner glass sheet, and a low emissivity film is provided on the fourth surface; α=RL / TL ２ The specular coefficient α calculated by the formula is 15 or less (where RL is the visible light reflectance of the laminated glass for a vehicle measured from the inside of the vehicle, and TL is the visible light transmittance of the laminated glass for a vehicle). A laminated glass for vehicles, characterized in that

2. 2. The laminated glass for vehicles according to claim 1, wherein the specular coefficient α is 3 to 10.

3. an edge region of the second surface is covered with a first dark-colored shielding layer, and / or an edge region of the third surface or the fourth surface is covered with a second dark-colored shielding layer; the width of the second dark shielding layer is greater than the width of the first dark shielding layer; The laminated glass for vehicles according to claim 1 .

4. 2. The laminated glass for vehicles according to claim 1, wherein the outer glass sheet is a transparent glass having a thickness of 1.8 mm to 4.2 mm and a visible light transmittance of 80% or more.

5. 2. The laminated glass for vehicles according to claim 1, wherein the inner glass sheet is a clear glass or a green glass having a thickness of 0.7 mm to 2.1 mm and a visible light transmittance of 80% or more.

6. 6. The laminated glass for vehicles according to claim 5, wherein the visible light transmittance of the inner glass sheet provided with the low-emissivity film is 50% to 70%.

7. The inner glass sheet provided with the low-emissivity coating has a value of α1=RL 内 / TL 内 ２ The specular coefficient α1 calculated by the formula is 0.1 or less (provided that RL 内 is the visible light reflectance of the inner glass sheet provided with the low-emissivity coating, measured from the side closest to the low-emissivity coating, and TL 内 is the visible light transmittance of the inner glass sheet provided with the low-emissivity coating), The laminated glass for vehicles according to claim 1 .

8. 2. The laminated glass for vehicles according to claim 1, wherein the visible light transmittance of the interlayer film is 1% to 20%.

9. 9. The laminated glass for vehicles according to claim 8, wherein the visible light transmittance of the interlayer film is 2% to 10%.

10. 9. The laminated glass for vehicles according to claim 8, wherein the interlayer is a colored thermoplastic polymer film comprising PVB, EVA, SGP, or PU.

11. the infrared reflective film includes at least one metal layer and at least two first dielectric layers; each metal layer is located between two adjacent first dielectric layers; The laminated glass for vehicles according to claim 1 .

12. The low-emissivity film includes at least one transparent conductive oxide layer and at least two second dielectric layers; each transparent conductive oxide layer is located between two adjacent second dielectric layers; The laminated glass for vehicles according to claim 1 .

13. 13. The laminated glass for a vehicle according to claim 12, wherein the low-emissivity film further comprises at least one visible light barrier layer in direct contact with the transparent conductive oxide layer.

14. The low-emissivity film has an emissivity of 0.25 or less and a surface resistance of 23 ohm / m ２ is as follows: The reflection hue of the inner glass sheet provided with the low-emissivity coating, measured from the side closest to the low-emissivity coating, is −10≦a≦2, −5≦b≦5 in the Lab system. The laminated glass for vehicles according to claim 1 .

15. the laminated glass for vehicles has a visible light transmittance TL of 0.5% to 10%, a visible light reflectance RL of the laminated glass for vehicles measured from the inside of the vehicle is 6% or less, and a total solar transmittance of the laminated glass for vehicles is 20% or less; The laminated glass for vehicles according to any one of claims 1 to 14.

16. 16. The laminated glass for vehicles according to claim 15, wherein the laminated glass for vehicles has a visible light reflectance RL measured from an interior side of the vehicle of 4% or less.

17. The laminated glass for vehicles according to any one of claims 1 to 16 is used as a roof window glass, a side window glass or a rear window glass of a vehicle.

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