Laminated glazing

Abstract

A laminated glazing for a vehicle windshield is described, comprising first and second sheets of glazing material joined by a sheet of adhesive interlayer material. The laminated glazing has an outward-facing surface and an inward-facing surface with a first treated region that has been subjected to a roughening process such that the first treated region has a first surface roughness before the roughening process and the first treated region has a second surface roughness after the roughening process. The first treated region with the second surface roughness aids in failure of the laminated glazing upon impact with the outward-facing surface. The use of the roughened region to reduce the time it takes for the laminated glazing to fail when struck by an impacting object is also described.

Description

[Technical Field]

[0001] The present invention relates to laminated glazing for use in automobiles, and more particularly for use as a windshield for automobiles. [Background technology]

[0002] Conventional laminated glazing for automotive windshields consists of two plies of soda-lime silicate glass bonded together with a polyvinyl butyral (PVB) sheet. Typically, each glass sheet is 2.1 mm thick, and the PVB sheet is typically 0.76 mm thick.

[0003] As is well known in this field, laminated windshields for automobiles offer improved safety advantages to the driver of a vehicle. However, automakers are also working on the safety of vehicles in the event of a frontal collision with a pedestrian.

[0004] In the event of a collision with a pedestrian, the pedestrian may hit the vehicle's windshield, potentially causing further injuries to the pedestrian.

[0005] International Publication No. 2013181505 describes a glass laminate comprising at least one chemically strengthened glass sheet having a thickness not exceeding 2.0 mm, and a polymer interlayer between the glass sheets. A defect is made on one surface of the glass sheet to weaken the glass laminate upon impact to a first side of the laminate, while maintaining the strength of the laminate upon impact to a second side on the opposite side.

[0006] European Patent Application Publication No. 2062862 describes a laminated glass structure manufactured by laminating at least three glass plates, each having a thickness of less than 1 mm, with an intermediate layer between two adjacent glass plates. [Overview of the project]

[0007] The present invention aims to provide a vehicle windshield that is positioned to reduce the risk of pedestrians suffering serious injuries in the event of a collision between a vehicle and a pedestrian.

[0008] Accordingly, in a first aspect, the present invention provides a laminated glazing for a vehicle windshield, comprising a first sheet of glazing material bonded to a second sheet of glazing material by at least one sheet of adhesive intermediate layer material, wherein each of the first and second sheets of glazing material has a first main surface and a second main surface, the second main surface of the first sheet of glazing material facing the first main surface of the second sheet of glazing material, and further comprising at least a first processing area, the first processing area having a first surface roughness before the roughening process and being subjected to a roughening process to have a second surface roughness after the roughening process.

[0009] It was found that by using a surface roughening process to provide a first processed area having a second roughness on the second main surface of a second sheet of glazing material, the second sheet of glazing material can be easily broken in the event of collision with the first main surface of the first sheet of glazing material.

[0010] The second main surface of the second sheet of glazing material has a first area, and the first processing area has a second area, preferably the second area being smaller than the first area.

[0011] Preferably, after the roughening process, the first processed area is semi-transparent.

[0012] Preferably, the first processing region has an outer periphery having one, two, three, four, five, six, seven, eight, nine, or ten sides.

[0013] Preferably, the first processing area has four sides.

[0014] Preferably, the first processing area has a rectangular, rhombic, parallelogram or square shape.

[0015] Preferably, the first processing area has an outer edge that is parallel or substantially parallel to at least a part of the outer edge of the second sheet of the graining material.

[0016] Preferably, the first processing area includes at least a first part and a second part, and the first part is inclined with respect to the second part.

[0017] In some embodiments, the roughening process includes irradiating at least a part of the first area to be processed with a laser to laser-etch the second main surface of the second sheet of the graining material in the first processing area. After the irradiation with the laser, at least a part of the first area is laser-etched.

[0018] Preferably, after the irradiation with the laser, the first processing area has a defect within the volume of the second sheet of the graining material, and the volume is bounded on one side by the first processing area.

[0019] Preferably, the laser is a carbon dioxide laser.

[0020] In some embodiments, the roughening process includes providing one or more scratches in the first processing area of the second surface of the second sheet of the graining material.

[0021] Preferably, the scratches are arranged randomly.

[0022] Preferably, the scratches are mechanically generated.

[0023] Preferably, the scratches are formed using an abrasive.

[0024] Preferably, the scratches are formed using sandpaper.

[0025] In some embodiments, the roughening process includes polishing a first treatment area of ​​a second surface of a second sheet of glazing material.

[0026] Preferably, polishing includes at least one sandblasting step. To avoid misunderstanding, in such embodiments, the surface roughening process includes at least one sandblasting step.

[0027] Preferably, the first processing area is sandblasted to a depth of at least 20 μm, preferably to a maximum depth of less than 500 μm.

[0028] Preferably, the first processing area is sandblasted to a depth of A μm to B μm, where A is preferably 20, or 25, or 30, or 35, or 40, or 45, or 50, or 55, or 60, or 65, or 70, and B is preferably 500, or 450, or 400, or 350, or 300, or 250, or 200, or 150, or 100.

[0029] In some embodiments, the roughening process includes polishing a first treated area of ​​the second surface of a second sheet of glazing material using an acid etching step.

[0030] To avoid misunderstanding, in such embodiments, the surface roughening process includes at least one acid etching step.

[0031] Preferably, the first processing area is acid-etched to a depth of at least 20 μm, preferably to a maximum depth of less than 500 μm.

[0032] Preferably, the first processing region is etched with an acid to a depth of A μm to B μm, where A is preferably 20, or 25, or 30, or 35, or 40, or 45, or 50, or 55, or 60, or 65, or 70, and B is preferably 500, or 450, or 400, or 350, or 300, or 250, or 200, or 150, or 100.

[0033] In some embodiments, the first processing region has an area of less than 10% of the area of the second major surface of the second sheet of the glazing material. The area of the first processing region is kept as small as possible so as not to affect the visual field of the laminated glazing.

[0034] Preferably, the first processing region has an area of less than 5%, or less than 4%, or less than 3%, or less than 2%, or less than 1% of the area of the second major surface of the second sheet of the glazing material.

[0035] In some embodiments, the first processing region is one of a plurality of processing regions, and the total area of the plurality of processing regions is preferably less than 10%, or less than 9%, or less than 8%, or less than 7%, or less than 6%, or less than 5%, or less than 4%, or less than 3%, or less than 2%, or less than 1% of the area of the second major surface of the second sheet of the glazing material.

[0036] In some embodiments, the first processing region is one of a plurality of processing regions, and the area of the first processing region is 0.01 cm 2 ~200 cm 2 , preferably 0.01 cm 2 ~100 cm 2 , more preferably 0.01 cm 2 ~10 cm 2 , even more preferably 0.01 cm[[ID=二十九]] 2 ~5 cm 2 , even more preferably 0.01 cm 2 ~0.5 cm 2 is.

[0037] Preferably, one or more processing areas in a plurality of processing areas are 0.01 cm² apart. 2 ~200cm 2 Preferably 0.01 cm 2 ~100cm 2 More preferably 0.01 cm 2 ~10cm 2 More preferably 0.01 cm 2 ~5cm 2 More preferably 0.01 cm 2 ~0.5cm 2 It has an area of ​​.

[0038] In some embodiments, the first processing area is one of a plurality of processing areas, and two or more of the processing areas have the same area.

[0039] Preferably, all processing areas in multiple processing areas have the same area.

[0040] In some embodiments, the first processing area is separated from the second processing area by a first distance, the first distance being 0.5 cm to 50 cm, more preferably 0.5 cm to 40 cm, more preferably 0.5 cm to 30 cm, more preferably 0.5 cm to 20 cm, and more preferably 0.5 cm to 10 cm.

[0041] In some embodiments, the first processing area is separated from the periphery of the laminated glazing.

[0042] Preferably, the first processing area is located 1 cm to 20 cm, more preferably 1 cm to 15 cm, more preferably 1 cm to 10 cm, more preferably 1 cm to 9 cm, or 1 cm to 8 cm, or 1 cm to 7 cm, or 1 cm to 6 cm, or 1 cm to 5 cm away from the periphery of the laminated glazing.

[0043] In some embodiments, the first processing area is separated from the periphery of the laminated glazing, which is configured to become the lower edge of the laminated glazing when installed in a vehicle.

[0044] Preferably, the first processing area is one of a plurality of processing areas spaced apart from the periphery of the laminated glazing, which is configured to become the lower edge of the laminated glazing when installed on a vehicle.

[0045] Preferably, the processing areas in a plurality of processing areas spaced apart from the periphery of the laminated glazing, which is configured to become the lower edge of the laminated glazing when mounted on a vehicle, are arranged in a row, and preferably the row is parallel to the periphery of the laminated glazing, which is configured to become the lower edge of the laminated glazing when mounted on a vehicle.

[0046] When the first processing area is one of a plurality of processing areas, it is preferable that each processing area has an area within ±20% of the same area.

[0047] When the first processing area is one of a plurality of processing areas, it is preferable that each processing area has the same area.

[0048] In some embodiments, the first sheet of glazing material has a thickness of 1 mm to 5 mm, preferably 1.3 mm to 3 mm.

[0049] In some embodiments, the second sheet of glazing material has a thickness of 1 mm to 5 mm, preferably 1.3 mm to 3 mm.

[0050] In some embodiments, the second sheet of glazing material is thinner than the first sheet of glazing material.

[0051] In some embodiments, the first main surface of the first sheet of glazing material is convex, and the second main surface of the second sheet of glazing material is convex.

[0052] In some embodiments, the second surface roughness is Rz greater than 20 μm, preferably Rz is 20 μm to 40 μm. As is known to those skilled in the art, Rz is the maximum profile height, which is the sum of the maximum profile peak height and the maximum profile valley depth within the sample length. The sample length may be less than 5 cm, preferably 0.5 cm to 4 cm, or 0.5 cm to 3 cm, or 0.5 cm to 2 cm, or 0.5 cm to 1 cm. The sample length may be 1 cm or more.

[0053] In some embodiments, the second surface roughness has an Ra in the range of 3 μm to 6 μm. Ra is the arithmetic mean deviation of the profile within the sample length. The sample length may be less than 5 cm, preferably 0.5 cm to 4 cm, or 0.5 cm to 3 cm, or 0.5 cm to 2 cm, or 0.5 cm to 1 cm. The sample length may be 1 cm or more.

[0054] In some embodiments, the second surface roughness has an Rmax in the range of 20 μm to 50 μm. Rmax is the maximum single roughness depth within the sample length. The sample length may be less than 5 cm, preferably 0.5 cm to 4 cm, or 0.5 cm to 3 cm, or 0.5 cm to 2 cm, or 0.5 cm to 1 cm. The sample length may be 1 cm or more.

[0055] In some embodiments, the second surface roughness has an Rv in the range of 10 μm to 20 μm. Rv is the maximum profile valley depth (Rv) within the sample length. The sample length may be less than 5 cm, preferably 0.5 cm to 4 cm, or 0.5 cm to 3 cm, or 0.5 cm to 2 cm, or 0.5 cm to 1 cm. The sample length may be 1 cm or more.

[0056] In some embodiments, the second surface roughness has a sample length Rz greater than 20 μm, preferably Rz is 20 μm to 40 μm, and / or has Ra in the region of 3 μm to 6 μm, and / or has Rmax in the range of 20 μm to 50 μm, and / or has Rv in the range of 10 μm to 20 μm. The sample length may be less than 5 cm, preferably 0.5 cm to 4 cm, or 0.5 cm to 3 cm, or 0.5 cm to 2 cm, or 0.5 cm to 1 cm. The sample length may be 1 cm or more.

[0057] In some embodiments, after impact by a suitable impactor at an impact site on the first main surface of the first sheet of glazing material, the laminated glazing propagates a crack in less than 2 ms near the impact site.

[0058] In such embodiments, the laminated glazing completely fails within 2 ms, preferably within 1 ms, which is the time it takes for the crack to propagate.

[0059] Preferably, the impactor is as described in UN Regulation No. 127 (E / ECE / 324 / Rev.2 / Add.126 / Rev.2).

[0060] Preferably, the impactor has a mass of 3 kg to 6 kg, more preferably 4 kg to 5 kg, and even more preferably 4.5 kg.

[0061] Preferably, the impactor is a sphere or a spheroid, and preferably has a diameter of 15 cm to 20 cm, more preferably 16 cm to 17 cm.

[0062] When the collision object hits the collision site, its speed is preferably 20 km / h to 50 km / h, more preferably 35 km / h to 45 km / h, and even more preferably 40 km / h.

[0063] Preferably, the impacting object collides with the impact site by falling under the influence of gravity alone.

[0064] Laminated glazing has other desirable characteristics.

[0065] Preferably, the laminated glazing is a vehicle windshield.

[0066] Preferably, the laminated glazing is curved in at least one direction. Preferably, the radius of curvature in at least one direction is 500 mm to 20,000 mm, more preferably 1,000 mm to 8,000 mm.

[0067] Preferably, at least one sheet of the adhesive intermediate layer material comprises an ethylene copolymer such as polyvinyl butyral (PVB), acoustic modified PVB, ethylene vinyl acetate (EVA), polyurethane (PU), polyvinyl chloride (PVC), an ethylene and methacrylic acid (EMA) copolymer, or Uvekol (liquid curable resin).

[0068] Preferably, at least one sheet of the adhesive intermediate layer material is a sheet of polyvinyl butyral (PVB), EVA, PVC, EMA, polyurethane, sound-absorbing modified PVB, or Uvekol (liquid curable resin).

[0069] Preferably, at least one sheet of the adhesive intermediate layer material has a thickness of 0.3 mm to 2.3 mm, more preferably 0.3 mm to 1.6 mm, and most preferably 0.3 mm to 0.8 mm.

[0070] Preferably, the first and / or second sheets of glazing material have a thickness between 1 mm and 3 mm.

[0071] Preferably, the first and / or second sheets of glazing material have a thickness of 1.4 mm to 2.8 mm, more preferably 1.6 mm to 2.3 mm.

[0072] Preferably, the first and / or second sheets of glazing material are sheets of soda-lime silicate glass. Soda-lime silicate glass is often called soda-lime silica glass, or simply sheet-like "soda-lime" glass.

[0073] Preferably, the first and / or second sheets of glazing material are sheets of soda-lime silicate glass, particularly sheets of float glass.

[0074] Preferably, the first and second sheets of glazing material are not chemically strengthened. When the sheets of glazing material are not subjected to an ion exchange process, or when subjected to an ion exchange process where the depth of the subsequent layer is 0 μm to DOL μm (where DOL is 1, 2, 3, 4, or 5), the sheets of glazing material can be classified as not chemically strengthened.

[0075] In some embodiments, the second sheet of glazing material is a sheet of alkali aluminosilicate glass.

[0076] Preferably, the second sheet of glazing material comprises at least about 6 wt% (weight percent) of aluminum oxide (Al2O3).

[0077] In some embodiments, the second sheet of glazing material is chemically strengthened, i.e., chemically strengthened glass. When the second sheet of glazing material is chemically strengthened, it preferably has a thickness of less than 1.2 mm, more preferably 0.3 mm to 1 mm, and even more preferably 0.4 mm to 0.9 mm.

[0078] The present invention also provides the use of one or more roughened areas on the first exposed surface of the laminated glazing to reduce the time it takes for the laminated glazing to break when struck by a suitable impactor in the impact area on the second exposed surface of the laminated glazing.

[0079] Preferably, the roughened area may include a sandblasted area and / or a laser etched area.

[0080] Preferably, the first exposed surface of the laminated glazing is the surface 4 of the laminated glazing, and the second exposed surface is the surface 1 of the laminated glazing.

[0081] As is customary in the art, surface 1 of the laminated glazing is the outermost surface of the laminated glazing, and surface 4 of the laminated glazing is an inward-facing surface defined with respect to the interior of the vehicle in which the laminated glazing is installed. The inward-facing surface of the laminated glazing faces the interior of the vehicle in which the laminated glazing is installed. The outermost surface (often called the exterior surface) faces the exterior of the vehicle in which the laminated glazing is installed.

[0082] Preferably, the impactor is as described in UN Regulation No. 127 (E / ECE / 324 / Rev.2 / Add.126 / Rev.2).

[0083] Preferably, the impactor has a mass of 3 kg to 6 kg, more preferably 4 kg to 5 kg, and even more preferably 4.5 kg.

[0084] Preferably, the impactor is a sphere or a spheroid, and preferably has a diameter of 15 cm to 20 cm, more preferably 16 cm to 17 cm.

[0085] When the collision object hits the collision site, its speed is preferably 20 km / h to 50 km / h, more preferably 35 km / h to 45 km / h, and even more preferably 40 km / h.

[0086] Preferably, the impacting object collides with the impact site by falling under the influence of gravity alone.

[0087] Preferably, the time it takes for the laminated glazing to break when impacted by an impactor is at least 50%, 60%, 70%, or 80% shorter than the time it takes for laminated glazing without one or more sandblasted areas on the first exposed surface to break.

[0088] The present invention will be described with reference to the following diagram. [Brief explanation of the drawing]

[0089] [Figure 1] This is a cross-sectional view of the laminated glazing according to the present invention. [Figure 2] This is a plan view of the laminated glazing according to the present invention. [Figure 3] This is a diagram showing the view from inside a vehicle having a windshield according to the present invention. [Figure 4] This is a plan view of another laminated glazing according to the present invention, similar to Figure 2. [Figure 5] This is a plan view of another laminated glazing according to the present invention, similar to Figure 2. [Figure 6] This is a schematic isometric view of the type of windshield described with reference to Figure 1. [Figure 7] Figure 6 is a schematic cross-sectional view of a method for testing the breakage characteristics of a vehicle windshield of the type shown. [Modes for carrying out the invention]

[0090] Figure 1 shows a cross-section of the curved laminated glazing according to the present invention.

[0091] The laminated glazing 1 has a first sheet 3 of soda lime silicate glass having a composition such as clear float glass, and iron oxide is usually added as a colorant to provide some form of sunlight control to the laminated glazing. The first sheet 3 has a thickness of 2.3 mm, but the thickness may be in the range of 1.4 mm to 2.5 mm or 1.6 mm to 2.3 mm.

[0092] The typical composition (by weight) of soda lime silicate glass is SiO2 69-74%, Al2O3 0-3%, Na2O 10-16%, K2O 0-5%, MgO 0-6%, CaO 5-14%, SO3 0-2%, and Fe2O3 0.005-2%. The glass composition may also contain other additives, such as refining aids, which are usually present in amounts up to 2%. Soda lime silica glass compositions may contain other colorants such as Co3O4, NiO, and Se to give the glass a desired color when viewed through transmitted light. The transmitted color of the glass can be measured based on recognized standards such as BS EN410.

[0093] The laminated glazing 1 also has a second sheet 7 of soda lime silicate glass having a thickness of 1.6 mm, but the second sheet may have a thickness in the range of 1.4 mm to 2.5 mm, preferably not as thick as the first sheet 3.

[0094] The first sheet 3 is bonded to the second sheet 7 by an adhesive interlayer 5. The adhesive interlayer 5 is a PVB sheet with a thickness of 0.76 mm. The adhesive interlayer 5 may have a thickness of 0.3 mm to 1.8 mm.

[0095] Other suitable adhesive interlayers include PVC, EVA, EMA, and polyurethane.

[0096] Laminated glazing 1 is curved in one or more directions. The radius of curvature of one of these directions is between 1000 mm and 8000 mm.

[0097] When laminated glazing curves in two directions, ideally, each curvature direction is orthogonal to the others. Ideally, the radius of curvature in one or both directions of curvature is between 1000 mm and 8000 mm.

[0098] The first sheet 3 has a first convex surface 9 and a second concave surface 11 on the opposite side. The second sheet 7 has a first convex surface 13 and a second concave surface 15 on the opposite side. The concave surface 11 of the first sheet 3 is in contact with the adhesive intermediate layer 5, and the convex surface 13 of the second sheet 7 is in contact with the adhesive intermediate layer 5. Using conventional nomenclature, the convex surface 9 of the first sheet 3 is "surface 1" (or S1) of the laminated glazing 1, the concave surface 11 of the first sheet 3 is "surface 2" (or S2) of the laminated glazing 1, the convex surface 13 of the second sheet 7 is "surface 3" (or S3) of the laminated glazing 1, and the concave surface 15 of the second sheet 7 is "surface 4" (or S4) of the laminated glazing 1.

[0099] An array of processing areas 17 is located on surface 4 (the concave surface 15 of the second sheet 7).

[0100] Figure 2 is a plan view of the laminated glazing 1 in the direction of arrow 10 in Figure 1.

[0101] In Figure 2, the periphery of the laminated glazing is typical of a vehicle windshield. The laminated glazing has a lower periphery 19, and inside the lower periphery 19 are six sandblasted areas 17a, 17b, 17c, 17c, 17e, and 17f, which form an array of processing areas 17. The sandblasted areas 17a, 17b, 17c, 17c, 17e, and 17f have different roughnesses compared to the roughness of the untreated surface 15 surrounding them.

[0102] Each sandblasting area 17a, 17b, 17c, 17c, 17e, and 17f is a square with sides of 2 cm. As a result, the area of ​​each sandblasting area 17a, 17b, 17c, 17c, 17e, and 17f is 4 cm². 2 That is the case.

[0103] The sandblasting areas 17a, 17b, 17c, 17c, 17e, and 17f are arranged at equal intervals such that the space between sandblasting area 17a and 17b is the same as the space between sandblasting area 17b and 17c, and so on for the others.

[0104] The sandblasting areas 17a, 17b, 17c, 17c, 17e, and 17f are arranged in a line parallel to the lower periphery 19.

[0105] The sandblasted area may be located in the layered glazing area where an obscuring band exists on the concave surface 15 of the second sheet 7.

[0106] By providing sandblasted areas 17a, 17b, 17c, 17c, 17e, and 17f, if an impact is applied to the first convex surface 9 of the first sheet 3, the second sheet 7 may become more susceptible to breakage, and the rigidity of the laminated glazing 1 decreases. When the laminated glazing 1 is installed in a vehicle as a windshield, if a pedestrian is involved in a collision with the vehicle, the reduced rigidity of the windshield upon impact with the first convex surface 9 reduces the severity of the pedestrian's injuries.

[0107] Figures 1 and 2 show only six sandblasted areas, but there may be more than six or fewer than six sandblasted areas. In some embodiments, there may be seven, eight, nine, ten or more sandblasted areas. In some embodiments, there may be one, two, three, four or five sandblasted areas. It is preferable to have areas that are sandblasted at equal intervals from one another. It is also preferable that each sandblasted area is sandblasted to the same depth and / or has the same dimensions and geometric shape, however, in some embodiments, one or more sandblasted areas are sandblasted to a different depth than one or more other sandblasted areas.

[0108] Another embodiment of the present invention is shown in Figure 3.

[0109] Figure 3 shows an inside view of a vehicle having the windshield 100 according to the present invention.

[0110] The windshield 100 is substantially the same as the laminated glazing 1 described above. The vehicle windshield has a lower edge extending between point E and point F. The vehicle windshield has an upper edge extending between point D and point G.

[0111] The surface 4 (inward-facing surface) of the windshield 100 has multiple sandblasting areas. There is a first array of sandblasting areas 174 having 20 square areas (only one of which is designated 175). Each square area 175 has dimensions ranging from 1 × 1 cm to 3 × 3 cm. Preferably, all squares 175 have the same size and / or area. The squares 175 are arranged in a row extending parallel to the lower periphery EF, i.e., the lower side of the squares 175 is aligned with and parallel to the lower periphery EF. The squares 175 may be oriented in different directions.

[0112] In this embodiment, the surface 4 of the windshield 100 also has a second array of sandblasted areas 172 extending along the left peripheral edge DE of the windshield 100 and a third array of sandblasted areas 176 extending along the right peripheral edge. The second array of sandblasted areas 172 has seven square areas (only one of which is shown as 173) whose lower side is parallel to the left peripheral edge DE. The third array of sandblasted areas 176 also has seven square areas (only one of which is shown as 177) whose lower side is parallel to the right peripheral edge FG.

[0113] Each of the sandblasting areas in the second and third arrays has the same size and / or area.

[0114] Referring to Figure 2, the sandblasted areas are created using a conventional sandblasting apparatus of the type used to sandblast the surface of a glass sheet. Each area 17a, 17b, 17c, 17e, and 17f is sandblasted to a depth of 50 μm to 150 μm, although deeper depths, such as 250 μm to 400 μm, are also possible.

[0115] Before sandblasting, the areas 17a, 17b, 17c, 17c, 17e, and 17f to be processed have the same roughness as the glass sheet and are smooth. Following sandblasting, the processed areas 17a, 17b, 17c, 17c, 17e, and 17f become rougher. According to "Glass Processing Days," September 13-15, 1997, pages 40-44, the surface roughness of float glass has an Rz of less than 0.1 μm. The processed areas are preferably semi-transparent after the processing, i.e., sandblasting, scratching, and acid etching.

[0116] The roughness parameters of a sandblasted float glass sheet can be determined using a suitable profiling sensor, such as a stylus or confocal displacement sensor. A method for evaluating surface profile parameters using a confocal displacement sensor is described in Procedia Materials Science, 5(2014), pp. 1385-1391.

[0117] Using a Hommel Tester T500 surface roughness tester available from Hommelwerke GmbH (Alte Tuttlinger Strasse 20, D-78056 VS- Schwenningen, Germany), it was found that sandblasting can be used to adjust the surface roughness of a 20 mm × 20 mm square area on a sheet of float glass to have an Rz greater than 20 μm, typically between 20 μm and 40 μm. As is known to those skilled in the art, Rz is the maximum profile height, which is the sum of the maximum profile peak height and the maximum profile valley depth within the sample length.

[0118] Another parameter commonly used to define surface roughness is the arithmetic mean deviation of the profile within the sample length (usually abbreviated as Ra in this art). It has been found that sandblasting a 20 mm × 20 mm area of ​​float glass surface can generate an Ra in the 3 μm to 6 μm range.

[0119] Other parameters that define surface roughness, such as the maximum single roughness depth (Rmax) or the maximum profile valley depth (Rv) within the sample length, may be used. By sandblasting a 20 mm × 20 mm area of ​​the float glass surface, it was possible to generate Rmax in the range of 20 μm to 50 μm and Rv in the range of 10 μm to 20 μm.

[0120] The following are specific examples of four different 20mm x 20mm sandblasted areas on a float glass sheet, measured with a Hommel Tester T500 surface roughness meter: (i) Ra=3.768μm, Rz=22.159μm, Rmax=26.173μm, Rv=11.811μm, (ii) Ra=3.775μm, Rz=20.441μm, Rmax=23.417μm, Rv=10.405μm, (iii) Ra=5.017μm, Rz=35.720μm, Rmax=47.800μm, Rv=18.100μm, (iv) Ra=5.093μm, Rz=33.666μm, Rmax=37.109μm, Rv=19.213μm.

[0121] Figure 4 is a plan view toward the surface 4 (S4) of another laminated glazing 30 having a structure similar to that of laminated glazing 1. Figure 4 is similar to the diagram in Figure 2, and its field of view is in the direction of arrow 10 in Figure 1.

[0122] The laminated glazing 30 has a first glass sheet having a thickness of 2.1 mm, which is bonded to a second glass sheet 32 ​​having a thickness of 1.6 mm by a PVB sheet having a thickness of 0.76 mm.

[0123] In Figure 4, the area surrounding the laminated glazing 30 is a typical vehicle windshield. The laminated glazing 30 has a lower periphery 34, and the inner portion of the lower periphery 34 of surface 4 is sandblasted to provide a rectangular sandblasted area 36. The rectangular sandblasted area 36 has a width of approximately 5 mm, but its width can be 2 mm to 50 mm. The rectangular sandblasted area 36 has a lower edge 38 parallel to the lower periphery 34 of the laminated glazing.

[0124] The sandblasted region 36 may be located within the layered glazing region, where an obscuration band exists, and a window may be provided in the obscuration band in which the sandblasted region is located.

[0125] Alternatively to the example shown in Figure 4, there may be at least two spaced-apart rectangular sandblasting regions. Each of the two rectangular sandblasting regions has its own lower edge, preferably the lower edge of the first rectangular sandblasting region is parallel to the lower edge of the second rectangular sandblasting region. It is also preferable that the lower edges of the first and second sandblasting regions are parallel to the lower periphery 34. There may be multiple such spaced-apart sandblasting rectangular regions, each having the same or different widths and spaced the same or different distances from each other.

[0126] Figure 5 is a plan view of the surface 4 of another laminated glazing 40 having a structure similar to that of laminated glazing 1 (the view from the direction of arrow 10 in Figure 1 is also similar).

[0127] The laminated glazing 40 comprises a first sheet of soda-lime silicate glass having a thickness of 1.8 mm, which is bonded to a second sheet 42 of soda-lime silicate glass having a thickness of 1.8 mm by a PVB sheet having a thickness of 0.76 mm.

[0128] The laminated glazing 40 has a curved lower edge 44, and the inner portion of the lower edge 44 of the surface 4 is sandblasted to provide a sandblasting area 46. The sandblasting area 46 has three portions 46a, 46b, and 46c that form a continuous sandblasting area 46.

[0129] Each of the parts 46a, 46b, and 46c is rectangular, and these parts are positioned substantially along the contour of the lower edge 44.

[0130] A second sandblasted area 48 is also provided on the surface 4 of the laminated glazing 40.

[0131] The second sandblasting area 48 is curved and has a lower edge 49 that is substantially parallel to the lower periphery 44 of the laminated glazing 40. The second sandblasting area 48 also has an upper edge 49' which is preferably parallel to the lower edge 49. The distance between the upper edge 49' and the lower edge 49 is 2 mm to 50 mm, i.e., 2 mm to 10 mm, and can be about 5 mm.

[0132] The laminated glazing 40 may have one or both of the sandblasted areas 46, 48. If there are two sandblasted areas 46, 48 (as shown in Figure 5), their relative positions may be switched such that the second sandblasted area 48 is between the lower edge 44 and sandblasted area 46.

[0133] The sandblasted regions 46 and 48 are symmetrical with respect to the axis m-m', which is the center line of the layered glazing 40.

[0134] Although the sandblasting regions 46 and 48 are each shown as continuous sandblasting regions, in other examples of the present invention, one or both of the sandblasting regions 46 and 48 may be formed by a plurality of cut sandblasting regions having substantially the same overall shape as the sandblasting regions 46 and 48.

[0135] For example, to test the effect of sandblasting on roughening a portion of the surface of the laminated glazing, the brittleness of the laminated glazing was measured.

[0136] Referring to Figures 6 and 7, the laminated glazing under test was constructed using conventional lamination conditions. The laminated glazing under test comprises a first sheet 53 of soda-lime silicate glass bonded to a second sheet 57 of soda-lime silicate glass by a sheet 55 of PVB. The laminated glazing was in the form of a vehicle windshield. The laminated glazing may have an obscuration band thereon, as is common in the art. Neither the first nor the second sheet 53, 55 was chemically strengthened.

[0137] The first sheet 53 has an exposed main surface 59, which is the "surface 1" (or S1) of the laminated glazing 51. The main surface 59 is convex.

[0138] The second sheet 57 has an exposed main surface 61, which is the "surface 4" (or S4) of the laminated glazing 51. The main surface 61 is concave.

[0139] The main surface 61 was sandblasted. In Figure 6, there are nine sandblasted square areas 77 (only one of which is labeled), so the plan view of the laminated glazing 51 in the direction of arrow 60 is similar to that shown in Figure 2 (except that there are nine squares instead of six).

[0140] In Figure 6, each square is 2 cm x 2 cm, approximately 10 cm to 15 cm away from adjacent squares, and the spacing can be uniform. The center of each square is 60 mm to 100 mm from the lower edge 54 of the laminated glazing 51. The lower edge of each square is positioned to follow the contour of the lower edge 54, and as a result, the nine squares are arranged not in a straight line, but in a curve similar to (or identical to) the curvature of the lower edge 54. However, the squares could also be arranged in a straight line.

[0141] Regardless of the arrangement of the sandblasting areas, the layered glazing was tested as follows, referring to Figures 6 and 7.

[0142] The laminated glazing 51 was initially placed within a horizontally positioned frame (not shown) and clamped around its periphery. The main surface 59 ("Surface 1") was facing upward and freely accessible; that is, the frame did not obstruct contact with the main surface 59.

[0143] Next, the impactor 67 is dropped onto the surface 59 at one of two locations. Due to the fracture properties of the test, only one laminated glazing can be tested at each impact location.

[0144] The first impact point 63 is located in the central position, substantially on the centerline n-n' of the laminated glazing, approximately 15 cm to 30 cm away from the lower edge 54' of the laminated glazing, and the actual distance from the lower edge 54' of the laminated glazing is kept the same during the test.

[0145] The second impact location 65 is oriented toward the side of the laminated glazing and represents the portion of the laminated glazing directly in front of the driver of the vehicle on which the laminated glazing 51 is installed. Because the laminated glazing is symmetrical with respect to the center line n-n', the second impact location is substantially the same as the portion of the laminated glazing directly in front of the passenger seat of the vehicle on which the laminated glazing 51 is installed.

[0146] The second impact location is approximately 15-30 cm away from the side 54'' of the laminated glazing and approximately 15-30 cm away from the bottom edge 54', and the actual distances from the side 54'' and bottom edge 54' of the laminated glazing are kept the same during the test.

[0147] The impactor 67 used in the test is a hollow plastic ellipsoid filled with steel shot and covered with felt. The total weight of impactor 67 is 4.5 kg, and its overall diameter is 165 mm.

[0148] The impactor used in the test is the same as that specified in UN Regulation No. 127 (E / ECE / 324 / Rev.2 / Add.126 / Rev.2).

[0149] The impactor 67 was positioned directly above the first or second impact position at a height sufficient to reach a velocity of 40 km / h at the selected impact position (by equalizing its potential energy with the acquired kinetic energy). Referring to Figure 7, the impactor 67 is directly above the first impact position 63, released under gravity, falls in the direction of arrow 68, and collides with the main surface 59 at the first impact position 63.

[0150] To ensure the same impact position for each sample, a vertical line may be used to position the impactor 67 at a desired location for contact with the glass surface upon impact.

[0151] As described above, in order to evaluate how the laminated glazing 51 breaks when the impactor 67 falls onto it, the test is recorded using a video camera 70 positioned on the laminated glazing 51. The video camera 70 operates at a high frame rate, such as 1000 frames per second (1000fps).

[0152] To classify the susceptibility of the laminated glazing 51 to failure, two failure criteria were identified by examining video recordings made during testing.

[0153] The first failure criterion is called the "initial failure time," and it is the time it takes from the time the impactor 67 makes contact with the main surface 59 at the selected impact location until the first crack is observed in the laminated glazing.

[0154] The second failure criterion is called the "complete failure time," which is the time it takes for the laminated glazing 51 to undergo catastrophic failure after the impactor 67 makes contact with the main surface 59 at the selected impact location.

[0155] To help determine the initial failure time and / or the complete failure time, one or more reference marks may be provided on the main surface 59 in a particularly selected area of ​​impact location. The reference marks may be in the form of a grid and may be applied to the main surface 59 using a suitable pen or the like.

[0156] Numerous layered glazing samples were evaluated as described above. Each layered glazing had substantially the same curvature. The results are shown in Table 1.

[0157] The samples in Table 1 are defined in terms of outer and inner glass plates. Referring to Figures 6 and 7, the first sheet 53 is called the "outer glass plate" because when the laminated glazing 51 is installed on the vehicle, the first sheet 53 faces the outside of the vehicle. Similarly, the second sheet 57 is called the "inner glass plate" because when the laminated glazing 51 is installed on the vehicle, the second sheet 57 faces the inside of the vehicle. Therefore, to simulate a collision with a pedestrian that may be involved in a frontal collision with a vehicle fitted with the laminated glazing 51, the impacting body 67 collides with the outer glass plate.

[0158] The sample details and results are shown in Table 1. Each inner and outer glass plate is a sheet of soda-lime silicate glass of the indicated thickness. The inner and outer glass plates are joined with a 0.76 mm thick PVB sheet. Neither the inner nor outer glass plates in these samples were chemically strengthened.

[0159] Two different types of sandblasted areas were evaluated on the surface 4 of the sample. The first type of sandblasted area consisted of nine 2cm × 2cm squares, as described with reference to Figures 6 and 7. The second type of sandblasted area evaluated was described with respect to area 46 in Figure 5, and had a total length of approximately 1.4m and a width of approximately 5mm. Referring to Figure 5, in the test performed, both lateral sections 46a and 46c were rectangular with a length of approximately 40cm, and the central section 46b was also rectangular with a length of approximately 60cm, and was substantially horizontal with respect to the horizontal line when the laminated glazing was mounted on the vehicle. The lateral sections 46a and 46c were inclined at an angle of approximately 20° to 30° with respect to the central section 46b, which was substantially determined by the curvature of the lower periphery of the sample.

[0160] In Table 1 below, the first type of sandblasted area is labeled "square," and the second type of sandblasted area is labeled "striped." The first collision location is called "center," and the second collision location is called "driver."

[0161] The table also shows the average depth of the sandblasted area for each sample, measured using a Hommel Tester T500 surface roughness meter.

[0162] Initial failure time and complete failure time are expressed in milliseconds (ms), respectively.

[0163] In Table 1 below, comparative samples 1-4 have inner and outer glass plates made of 1.8 mm thick soda-lime silicate glass bonded with a 0.76 mm PVB sheet. Comparative samples 5-8 have inner and outer glass plates made of 1.4 mm and 1.8 mm thick soda-lime silicate glass, respectively, bonded with a 0.76 mm PVB sheet. Comparative samples 1-8 do not have a sandblasted area.

[0164] The results in Table 1 show that in cases without a sandblasted area (Comparative Examples 1-8), the laminated glazing has an initial failure time of 4-6 ms after the surface 59 is impacted by the impactor 67 in the selected impact area. Most of the comparative samples have an initial failure time of 5 ms.

[0165] As can be seen from Table 1, the final failure time occurs immediately after the initial failure time, usually within those milliseconds.

[0166] The results in Table 1 show that providing a sandblasted area (of the type described above) to the surface 4 of the laminated glazing reduces the initial failure time from 4 ms to approximately 1 ms or less. The final failure time is also reduced.

[0167] This indicates that, for example, in a frontal collision with a pedestrian, a windshield with a sandblasted area is more prone to breakage. The reduced rigidity of the windshield upon breakage can mitigate serious injuries to the pedestrian.

[0168] Instead of the array of sandblasted square regions described with reference to Figures 2, 3, and 6, other shaped regions, such as rhombuses, circles, trapezoids, or other irregular shapes, are expected to behave similarly. Symmetrical regions and / or regions of the same shape may provide laminated glazing with the advantages detailed in Table 1 at two or more impact locations on the surface 1 of the windshield.

[0169] Furthermore, similar advantages can be expected when using other similar tests, such as UN Regulation No. 127 (E / ECE / 324 / Rev.2 / Add.126 / Rev.2), to determine the failure characteristics of laminated glazing.

[0170] [Table 1-1]

[0171] [Table 1-2]

[0172] It was found that by treating the inward-facing surface area of ​​the laminated windshield, the inward-facing glass sheet becomes more easily damaged when a pedestrian collides with the outward-facing surface of the laminated windshield. The treated area is positioned so as not to obstruct the vehicle driver's view and does not degrade the windshield's performance in stone chip impact tests.

Claims

1. A laminated glazing for a vehicle windshield, comprising a first sheet of glazing material bonded to a second sheet of glazing material by at least one sheet of adhesive intermediate layer material, wherein each of the first and second sheets of glazing material has a first main surface and a second main surface, the second main surface of the first sheet of glazing material facing the first main surface of the second sheet of glazing material, and further comprising at least a first processing region, the first processing region having a first surface roughness before the roughening process and being subjected to a roughening process to have a second surface roughness after the roughening process. The first processing area is one of a plurality of processing areas subjected to the same surface roughening process as the first processing area, and the area of ​​the first processing area is 0.01 cm². ２ ~200cm ２ This is a laminated glazing for vehicle windshields.

2. The laminated glazing according to claim 1, wherein the first and second sheets of the glazing material are not chemically strengthened.

3. The laminated glazing according to claim 1 or 2, wherein the first processing area is semi-transparent to visible light.

4. The laminated glazing according to any one of claims 1 to 3, wherein the roughening process includes providing one or more scratches in the first processed area of ​​the second main surface of the second sheet of the glazing material.

5. The laminated glazing according to claim 4, wherein the scratch is mechanically generated.

6. The laminated glazing according to any one of claims 1 to 5, wherein the roughening process includes polishing the first treatment area of ​​the second main surface of the second sheet of the glazing material.

7. The laminated glazing according to any one of claims 1 to 6, wherein the first processing area comprises a sandblasting area or an acid etching area.

8. The laminated glazing according to any one of claims 1 to 3, wherein the first processed area after the roughening process is a sandblasted area having a sandblasting depth of at least 20 μm.

9. The laminated glazing according to claim 8, wherein the sandblasting depth is less than 500 μm.

10. The laminated glazing according to any one of claims 1 to 9, wherein the first processing area is one of the plurality of processing areas, and the total area of ​​the plurality of processing areas is less than 10%, less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1% of the area of ​​the second main surface of the second sheet of the glazing material.

11. The area of the first processing region is 0.01 cm ２ to 100 cm ２ , preferably 0.01 cm ２ to 10 cm ２ , more preferably 0.01 cm ２ to 5 cm ２ , even more preferably 0.01 cm ２ to 0.5 cm ２ The laminated glazing according to any one of claims 1 to 10, which is such.

12. One or more of the processing areas in the aforementioned plurality of processing areas is 0.01 cm. ２ ~200cm ２ Preferably 0.01 cm ２ ~100cm ２ , more preferably 0.01 cm ２ ~10cm ２ More preferably 0.01 cm ２ ~5cm ２ More preferably 0.01 cm ２ ~0.5cm ２ The laminated glazing according to claim 11, having the area of ​​the above.

13. The laminated glazing according to any one of claims 1 to 12, wherein the first processing area is one of the plurality of processing areas, two or more of the processing areas have the same area, and preferably all of the plurality of processing areas have the same area.

14. The laminated glazing according to any one of claims 1 to 13, wherein the first processing area is separated from the second processing area by a first interval, where the second processing area has a first surface roughness before the roughening process and has been subjected to the roughening process to have a second surface roughness after the roughening process, and the first interval is 0.5 cm to 50 cm, more preferably 0.5 cm to 40 cm, more preferably 0.5 cm to 30 cm, more preferably 0.5 cm to 20 cm, and more preferably 0.5 cm to 10 cm.

15. The laminated glazing according to any one of claims 1 to 14, wherein the first processing area is separated from the periphery of the laminated glazing.

16. The laminated glazing according to claim 15, wherein the first processing area is located 1 cm to 20 cm, more preferably 1 cm to 15 cm, more preferably 1 cm to 10 cm, more preferably 1 cm to 9 cm, or 1 cm to 8 cm, or 1 cm to 7 cm, or 1 cm to 6 cm, or 1 cm to 5 cm away from the periphery of the laminated glazing.

17. The laminated glazing according to claim 15 or 16, wherein the first processing area is spaced apart from the periphery of the laminated glazing, which is configured to become the lower edge of the laminated glazing when mounted on a vehicle.

18. The laminated glazing according to any one of claims 1 to 17, wherein the first sheet of the glazing material has a thickness of 1 mm to 5 mm, preferably 1.3 mm to 3 mm.

19. The laminated glazing according to any one of claims 1 to 18, wherein the second sheet of the glazing material has a thickness of 1 mm to 5 mm, preferably 1.3 mm to 3 mm.

20. The laminated glazing according to any one of claims 1 to 19, wherein the second sheet of the glazing material is thinner than the first sheet of the glazing material, and / or the laminated glazing has a thickness of 3 mm to 10 mm.

21. The laminated glazing according to any one of claims 1 to 20, wherein the first processing region is located within the region of the laminated glazing having an obscuration band thereon.

22. The laminated glazing according to any one of claims 1 to 21, wherein the roughening process includes irradiating at least a portion of the first region to be processed with a laser to laser-etch the second main surface of the second sheet of the glazing material in the first processing region.

23. The laminated glazing according to claim 22, wherein in the volume of the second sheet of the glazing material bounded by the first processing region, defects are formed following irradiation with the laser.

24. The laminated glazing according to any one of claims 1 to 23, wherein the second surface roughness has an Rz greater than 20 μm.

25. The laminated glazing according to any one of claims 1 to 24, wherein the second surface roughness has an Ra in the range of 3 μm to 6 μm.

26. The laminated glazing according to any one of claims 1 to 25, wherein the second surface roughness has an Rmax in the range of 20 μm to 50 μm.

27. The laminated glazing according to any one of claims 1 to 26, wherein the second surface roughness has an Rv in the range of 10 μm to 20 μm.

28. The laminated glazing according to any one of claims 1 to 27, wherein the laminated glazing propagates a crack around the impact site in less than 2 ms following an impact by a suitable impactor at the impact site on the first main surface of the first sheet of the glazing material, wherein the impactor is (i) as described in UN Regulation No. 127 (E / ECE / 324 / Rev.2 / Add.126 / Rev.2), or (ii) the impactor has a mass of 3 kg to 6 kg, and the impactor is a sphere or a spheroid, and the impactor impacts the impact site at a velocity of 20 km / h to 50 km / h.

29. A vehicle windshield comprising laminated glazing according to any one of claims 1 to 28.

30. The use of at least a first roughened area on the first exposed surface of a laminated glazing to reduce the time it takes for the laminated glazing to break when struck by a suitable impactor in an impact area on the second exposed surface of the laminated glazing, wherein the first roughened area is one of a plurality of roughened areas, and the area of ​​the first roughened area is 0.01 cm². ２ ~200cm ２ The collision body has a mass of 3 kg to 6 kg, and the collision body is a sphere or a spheroid, and when the collision body collides with the collision position, its velocity is 20 km / h to 50 km / h, and the first roughening region is the use of one or more roughening regions on the first exposed surface of the laminated glazing, comprising a sandblasted region and / or a laser etched region.

31. The use according to claim 30, wherein the first exposed surface is the surface 4 of the laminated glazing, and the second exposed surface is the surface 1 of the laminated glazing.

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