Laminated glazing

Abstract

A laminated glazing for a vehicle windshield is described, comprising a first sheet of glazing material joined to a second sheet of glazing material by an intermediate film. The intermediate film is between the first and second sheets of glazing material and comprises a first section of adhesive interlayer material and a second section of adhesive interlayer material. The first and second sections of the intermediate film are positioned such that a first edge of the first section of the intermediate film faces a first edge of the second section of the intermediate film. The first edge of the first section of the intermediate film is spaced from the first edge of the second section of the intermediate film.

Description

[Technical Field]

[0001] LAMINATED GLAZING FIELD OF THE INVENTION The present invention relates to laminated glazing for use in vehicles, particularly for use as an automobile windscreen. [Background technology]

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

[0003] As is known in the art, laminated automotive windshields provide improved safety benefits to vehicle operators. However, automobile manufacturers also address the safety of their automobiles in the event of a frontal collision with a pedestrian.

[0004] In the event of a collision with a pedestrian, the pedestrian may be struck by the vehicle's windshield, which may result in further injury to the pedestrian.

[0005] From Japanese Patent Publication No. 4844362, it is known to use a section of interlayer material in the construction of laminated glazing. The laminated glazing is formed by sandwiching an intermediate film between several glass sheets (external and internal sheets). The intermediate film has at least a first and a second region in the front view. The first region is a region extending along the underside and / or at least one of both sides of the laminated glazing. The tensile stiffness of the intermediate film in the first region is higher than that of the intermediate film in the second region. The tensile stiffness is given by the product of the elastic modulus of the intermediate film and its thickness.

[0006] WO 2012 / 033894 discloses a laminated transparent sheet comprising a first ply having a first surface and a second surface. A second ply is spaced from the first ply and has a third surface and a fourth surface, with the second surface facing the third surface. A polymer interlayer is positioned between the first and second plies. At least one failure strip is incorporated into the interlayer to provide the transparent sheet with a predetermined failure orientation. Summary of the Invention

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

[0008] Thus from a first aspect, the present invention provides a laminated glazing for a vehicle windshield comprising a first sheet of glazing material joined to a second sheet of glazing material by an intermediate film, the first and second sheets of glazing material each having a first major surface and an opposite second major surface, the laminated glazing being arranged such that the second major surface of the first sheet of glazing material faces the first major surface of the second sheet of glazing material and the intermediate film is between the first and second sheets of glazing material, the intermediate film having a first section of adhesive interlayer material and an adhesive intermediate film. A laminated glazing for a vehicle windshield is provided, comprising a second section of interlayer material, wherein the first section of the intermediate film extends over the first section of the second major surface of the first sheet of glazing material, the second section of the intermediate film extends over the second section of the second major surface of the first sheet of glazing material, the first and second sections of the intermediate film are arranged such that a first edge of the first section of the intermediate film faces a first edge of the second section of the intermediate film, and further, the first edge of the first section of the intermediate film is spaced apart from the first edge of the second section of the intermediate film.

[0009] Having at least a first space between the first edge of the first section of the intermediate film and the first edge of the second section of the intermediate film provides a weakness in the laminated glazing, thereby making the laminated glazing more easily breakable in the region of the first space between the first edge of the first section of the intermediate film and the first edge of the second section, because there is no adhesive intermediate film within that space.

[0010] Preferably, a barrier is located between the first edge of the first section of the intermediate film and the first edge of the second section of the intermediate film.

[0011] By having a barrier between the first edge of the first section of the intermediate film and the first edge of the second section of the intermediate film, the intermediate film does not bond the first sheet of glazing material to the second sheet of glazing material near the barrier, which makes it easier to fracture the laminated glazing in the area of ​​the barrier material.

[0012] Preferably, the barrier is in the entire space between the first edge of the first section of the intermediate film and the first edge of the second section of the intermediate film.

[0013] Preferably, the barrier comprises a first wall facing the first edge of the first section of the intermediate film and a second wall facing the first edge of the second section of the intermediate film, and preferably the first wall of the barrier is spaced apart from the second wall of the barrier.

[0014] Preferably, the barrier is dimensionally stable during the lamination process used to make the laminated glazing.

[0015] Preferably, the barrier comprises polyethylene terephthalate (PET) or polycarbonate (PC).

[0016] Preferably, the barrier is compressible so that the barrier forms a seal with the second major surface of the first sheet of glazing material and / or the first major surface of the second sheet of glazing material.

[0017] Preferably, the barrier comprises an elastomeric material such as rubber, more preferably silicone rubber.

[0018] In some embodiments, the barrier comprises a first tape covering a first edge of a first section of the intermediate film.

[0019] Preferably, the first tape comprises a strip of polymeric material, preferably comprising PET. Preferably, the strip of polymeric material comprises at least one adhesive area on at least one surface thereof.

[0020] In some embodiments, the barrier comprises a second tape covering a first edge of the second section of the intermediate film.

[0021] Preferably, the second tape comprises a strip of polymeric material, preferably comprising PET. Preferably, the strip of polymeric material comprises at least one adhesive area on at least one surface thereof.

[0022] In some embodiments, the intermediate film comprises a third section of adhesive interlayer material, the third section of the intermediate film having a first edge, the third section of the intermediate film spaced apart from the first and second sections of the intermediate film, and the first edge of the third section of the intermediate film facing the first edge of the first section of the intermediate film.

[0023] Preferably, there is a barrier between the first edge of the first section of the intermediate film and the first edge of the third section of the intermediate film.

[0024] In some embodiments, the intermediate film comprises a third section of adhesive interlayer material, the third section of the intermediate film having a first edge, the third section of the intermediate film spaced apart from the first and second sections of the intermediate film, and the first edge of the third section of the intermediate film facing the second edge of the first section of the intermediate film.

[0025] Preferably, the first edge of the first section of the intermediate film and the second edge of the first section of the intermediate film extend along opposite sides of the first section of the intermediate film.

[0026] Preferably, the first and second edges of the first section of the intermediate film intersect to form a corner portion of the first section of the intermediate film.

[0027] Preferably, there is a second barrier between the second edge of the first section of the intermediate film and the first edge of the third section of the intermediate film.

[0028] In some embodiments, the intermediate film comprises a third section of adhesive interlayer material having a first edge and a second edge, the second sections of the intermediate film each having a second edge, the third sections of the intermediate film being spaced apart from the second sections of the intermediate film, and the second edge of the second sections of the intermediate film facing the second edge of the third sections of the intermediate film.

[0029] Preferably, there is a third barrier between the second edge of the second section of the intermediate film and the second edge of the third section of the intermediate film.

[0030] In some embodiments, the intermediate film comprises, in addition to the first and second sections, a plurality of other sections of adhesive interlayer material, each of the plurality of other sections of the intermediate film having a first edge and spaced apart from the first and second sections of the intermediate film, and further, at least one of the plurality of other sections has its respective first edge facing the first edge of the first section of the intermediate film.

[0031] Preferably, the first edge of each of the plurality of other sections of the intermediate film faces the first edge of the first section of the intermediate film.

[0032] Preferably, there is a barrier between the first edge of the first section of the intermediate film and the first edge of the or each of the plurality of other sections of the intermediate film.

[0033] In some embodiments, the intermediate film comprises, in addition to the first and second sections, a plurality of other sections of adhesive interlayer material, each of the plurality of other sections of the intermediate film having a first edge and spaced apart from the first and second sections of the intermediate film, and at least one of the plurality of other sections is positioned such that its respective first edge faces the second edge of the first section of the intermediate film.

[0034] Preferably, the first edge of each of the plurality of other sections of the intermediate film faces the second edge of the first section of the intermediate film.

[0035] Preferably, there is a barrier between the second edge of the first section of the intermediate film and the first edge of the or each of the plurality of other sections of the intermediate film.

[0036] In some embodiments, the intermediate film comprises, in addition to the first and second sections, a plurality of other sections of adhesive interlayer material, each of the plurality of other sections of the intermediate film having a first edge and spaced apart from the first and second sections of the intermediate film, and further, at least one of the plurality of other sections is positioned so that its respective first edge faces the second edge of the first section of the intermediate film, and at least one of the plurality of other sections is positioned so that its respective first edge faces the third edge of the first section of the intermediate film.

[0037] Preferably, there is a barrier between the second edge of the first section of the intermediate film and the first edge of the or each of the plurality of other sections of the intermediate film.

[0038] Preferably, there is a barrier between the third edge of the first section of the intermediate film and the first edge of the or each of the plurality of other sections of the intermediate film.

[0039] In embodiments having multiple other sections of adhesive interlayer material of the intermediate film, preferably each section of the multiple other sections is spaced apart from other sections of the multiple other sections.

[0040] In embodiments having multiple other sections of adhesive intermediate layer material of the intermediate film, preferably each of the multiple other sections has a respective second edge, and two of the multiple other sections are arranged with their respective second edges facing each other, preferably with a barrier between them.

[0041] In embodiments having multiple other sections of adhesive interlayer material of the intermediate film, each section of the multiple other sections comprises the same adhesive interlayer material.

[0042] Preferably, each of the plurality of other sections is of the same adhesive interlayer material.

[0043] In some embodiments, the first sheet of glazing material has a thickness of from 1 mm to 5 mm, preferably from 1.3 mm to 3 mm.

[0044] In some embodiments, the second sheet of glazing material has a thickness of from 1 mm to 5 mm, preferably from 1.3 mm to 3 mm.

[0045] In some embodiments, the second sheet of glazing material is thinner than the first sheet of glazing material.

[0046] In some embodiments, the first major surface of the first sheet of glazing material is convex and the second major surface of the second sheet of glazing material is convex.

[0047] In some embodiments, the first and / or second sheets of glazing material comprise one or more points or lines of weakness positioned to further weaken the laminated glazing upon impact with the laminated glazing.

[0048] Preferably, the points or lines of weakness are on a major surface of the first and / or second sheets of glazing material.

[0049] Preferably, the point or line of weakness is aligned with the first edge of the first or second section of the intermediate film.

[0050] Preferably, in plan view, the point or line of weakness is located in the space between the first edge of the first section and the first edge of the second section.

[0051] Preferably, the weak spots or lines are created by mechanical or thermal means such as localized heating, preferably with a laser.

[0052] In some embodiments, the laminated glazing comprises an obscuring band on at least a portion of the first and / or second major surfaces of the first and / or second sheets of glazing material.

[0053] Preferably, the obscuring band covers at least a portion of the first edge of the first and / or second section.

[0054] When there is a barrier between the first edge of the first section of the intermediate film and the first edge of the second section of the intermediate film, preferably at least a portion of the barrier between the first edge of the first section of the intermediate film and the first edge of the second section covers at least a portion of the obscuration band.

[0055] In some embodiments, the first edge of the first section of the intermediate film is separated from the first edge of the second section of the intermediate film by a barrier comprising a first wall and a first void, the first wall being between the first edge of the first section of the intermediate film and the first void.

[0056] Preferably, the barrier comprises a second wall, the second wall being between the first edge of the second section of the intermediate film and the first void, and the first void being between the first wall and the second wall of the barrier.

[0057] Preferably, the gap is an air space.

[0058] Laminated glazing has other desirable features.

[0059] Preferably, the first section is the central section.

[0060] Preferably, the second section is a lower section such that in use the second section is below the first section.

[0061] 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.

[0062] Preferably, the adhesive interlayer material used for the first and / or second sections of the intermediate film is polyvinyl butyral (PVB), sound-absorbing modified PVB, ethylene vinyl acetate (EVA), copolymers of ethylene, Comprising polyurethane (PU), polyvinyl chloride (PVC), copolymer of ethylene and methacrylic acid (EMA) or Uvekol (liquid curable resin).

[0063] Preferably, the adhesive interlayer material used in the first section of the intermediate film is the same as the adhesive interlayer material used in the second section of the intermediate film.

[0064] Preferably, the intermediate film has a thickness of 0.3 mm to 2.3 mm, more preferably 0.3 mm to 1.6 mm, most preferably 0.3 mm to 0.8 mm.

[0065] Preferably, the first section of the intermediate film has a thickness of 0.3 mm to 2.3 mm, more preferably 0.3 mm to 1.6 mm, most preferably 0.3 mm to 0.8 mm.

[0066] Preferably, the second section of the intermediate film has a thickness of 0.3 mm to 2.3 mm, more preferably 0.3 mm to 1.6 mm, most preferably 0.3 mm to 0.8 mm.

[0067] Preferably, the first and / or second sheets of glazing material have a thickness of between 1 mm and 3 mm.

[0068] Preferably, the first and / or second sheets of glazing material have a thickness of between 1.4 mm and 2.8 mm, more preferably between 1.6 mm and 2.3 mm.

[0069] Preferably, the first and / or second sheets of glazing material are sheets of soda-lime silicate glass, which is often referred to as soda-lime-silica glass, or simply sheet "soda-lime" glass.

[0070] Preferably, the first and / or second sheets of glazing material are sheets of soda lime silicate glass, in particular sheets of float glass.

[0071] Preferably, the first and / or second sheets of glazing material are sheets of alkali aluminosilicate glass.

[0072] Preferably, the first and / or second sheets of glazing material comprise at least about 6 wt% (weight percent) aluminum oxide (Al2O3).

[0073] Preferably, the first and / or second sheets of glazing material are chemically strengthened, i.e., chemically strengthened glass. When the first and / or second sheets of glazing material are chemically strengthened, preferably the first and / or second sheets of glazing material have a thickness of less than 1.2 mm, more preferably between 0.3 mm and 1 mm, even more preferably between 0.4 mm and 0.9 mm.

[0074] Preferably the laminated glazing is a vehicle windshield.

[0075] The present invention also provides, from a second aspect, the use of laminated glazing according to the first aspect of the invention as a windscreen in a vehicle to reduce the likelihood of injury to persons involved in a collision with the vehicle.

[0076] The invention will now be described with reference to the following figures (not to scale): [Brief explanation of the drawings]

[0077] [Figure 1]1 is a plan view of a laminated glazing according to the present invention; FIG. [Figure 2] 2 is a schematic cross-sectional view of the laminated glazing shown in FIG. 1 along line A-A'. [Figure 3] 2 is a schematic cross-sectional view of another laminated glazing similar to that shown in FIG. 1 taken along line A-A'. [Figure 4] 2 is a schematic exploded cross-sectional view along line A-A' of another laminated glazing similar to that shown in FIG. 1. [Figure 5] 1 is a schematic cross-sectional view of an adhesive interlayer material and a cross section of a tape to form a barrier. [Figure 6] 1 is a view from the inside of a vehicle in which a windshield according to the present invention is installed. [Figure 7] 7 is a schematic diagram of an intermediate film used in the windshield of the vehicle shown in FIG. 6. FIG. [Figure 8] FIG. 8 is an enlarged view of a corner of the intermediate film shown in FIG. 7. [Figure 9] 1 is a schematic diagram used to explain the method for manufacturing laminated glazing according to the invention; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0078] Figure 1 is a plan view of a laminated glazing 1 according to the invention. In this embodiment, the laminated glazing 1 is a vehicle windshield of the type used in automobiles.

[0079] Referring to Figures 1 and 2, laminated glazing 1 has a first glass sheet 3. The glass may have a soda-lime-silicate composition, such as clear float glass, and the glass may contain a level of iron oxide as a colorant to provide some form of solar control to the laminated glazing. First glass sheet 3 has a thickness of 2.3 mm, but the thickness may range from 1.4 mm to 2.5 mm or from 1.6 mm to 2.3 mm.

[0080] The laminated glazing 1 also has a second glass sheet 5 having a thickness of 1.6 mm, although the second sheet may have a thickness ranging from 1.4 mm to 2.5 mm. The second glass sheet 5 may be the same thickness as the first glass sheet 3. Preferably, the second glass sheet is not as thick as the first glass sheet 3.

[0081] The typical composition (by weight) of soda-lime silicate glass is 69-74% SiO2, 0-3% Al2O3, 10-16% Na2O, 0-5% K2O, 0-6% MgO, 5-14% CaO, 0-2% SO3, and 0.005-2% Fe2O3. The glass composition may also contain other additives, such as refining aids, which may be present in amounts typically up to 2%. Soda-lime silicate glass compositions may contain other colorants, such as Co3O4, NiO, and Se, to impart a desired color to the glass when viewed through transmitted light. The transmitted color of glass can be measured according to recognized standards, such as BS EN 410.

[0082] Other glass compositions may also be used, and the first and / or second glass sheets may be chemically strengthened. When chemically strengthened glass sheets are used, the thickness of such glass sheets is preferably less than 1 mm, more preferably in the range of 0.4 mm to 0.9 mm.

[0083] The first glass sheet 3 is joined to the second glass sheet 5 by an intermediate film comprising a first section 7 of adhesive interlayer material and a second section 9 of adhesive interlayer material. The first and second sections 7, 9 each have a thickness of 0.76 mm, and in this example are sheets of polyvinyl butyral (PVB) such that the intermediate film has a thickness of 0.76 mm. Both the first and second sections 7, 9 are cut from the same roll of PVB, and before being laminated, the first and second sections 7, 9 are in sheet form.

[0084] The intermediate film may have a thickness of 0.3 mm to 1.8 mm.

[0085] Other suitable adhesive interlayer materials include acoustically modified PVB, copolymers of ethylene such as ethylene vinyl acetate (EVA), polyurethane (PU), polyvinyl chloride (PVC), copolymers of ethylene and methacrylic acid (EMA) or Uvekol (a liquid curable resin).

[0086] The laminated glazing 1 may be curved in one or more directions. The radius of curvature in one of the one or more directions may be between 1000 mm and 8000 mm.

[0087] When the laminated glazing is curved in two directions, the directions of curvature are suitably perpendicular to each other. Suitably, the radius of curvature in one or both directions of curvature may be from 1000 mm to 8000 mm.

[0088] The first and second sections 7, 9 of the PVB are separated by a barrier 11. Referring to Figure 2, the lower edge 9a of the second section 9 of the PVB faces the upper edge 7a of the first section 7 of the PVB and is separated therefrom by the barrier 11.

[0089] The use of a barrier is a convenient way to ensure that the first section 7 of PVB remains spaced apart from the second section 9 of PVB following a suitable lamination process for joining the first glass sheet 3 to the second glass sheet 5 by the intermediate film. During such lamination processes, which use appropriately high temperatures and pressures, the first and / or second sections 7, 9 of PVB may flow such that their edges are at least partially or completely fused together and no longer spaced apart. The barrier 11 helps to prevent this from happening; it is within the scope of the invention to not provide a barrier after lamination, but the first and second sections of the intermediate film are separated by at least the first space.

[0090] In Figure 2, barrier 11 is made of polyethylene terephthalate (PET) and is between a first edge 7a of a first section 7 of PVB and a first edge 9a of a second section 9 of PVB. During a suitable lamination process, barrier 11 forms a seal between the opposing inner major surfaces of the first and second glass sheets, thereby preventing the first and second sections 7, 9 of PVB from being bonded together.

[0091] Laminated glazing 1 has lower region 1a, upper region 1b, and central region 1c. The central region is typically a through-vision region, while lower region 1a may include an obscuration band in the area below line 12. By providing an obscuration band that extends above barrier 11 in plan view (see FIG. 1, barrier 11 is below the area defined by line 12), barrier 11 may be hidden from view.

[0092] When installed in a vehicle, the peripheral edges of the upper and lower regions 1a, 1b are typically bonded to an opening in the vehicle body in a manner known in the art.

[0093] Upon impact in the direction of arrow 13, the barrier 11 presents a line of weakness in the laminated glazing 1. This is because the barrier is not a hot melt adhesive and the intermediate film does not bond the first and second glass sheets 3, 5 together in the area of ​​the barrier. In the area of ​​the barrier 11, the first and second glass sheets 3, 5 do not behave like laminated glazing, but rather like two panes of glass spaced apart from each other. As a result, the laminated glazing 1 may break more easily in the area of ​​the barrier 11.

[0094] As can be seen from FIG. 2, the first section 7 of the PVB is coplanar with the second section 9 of the PVB.

[0095] FIG. 3 shows a cross-sectional view of another laminated glazing 21 having substantially the same plan view as the laminated glazing 1 shown in FIG.

[0096] In Figure 3, a different barrier 31 is used to separate first and second sections 7, 9 of PVB that are used to bond together first and second glass sheets 3, 5. Portions of Figure 3 have been enlarged for clarity.

[0097] 3, the barrier 31 has a double-walled structure such that a first wall 31a of the barrier faces a first edge 7a of a first section 7 of the PVB, and a second wall 31b of the barrier faces a first edge 9a of a second section 9 of the PVB. The first and second walls 31a, 31b of the barrier are separated by a gap 31c, such as an air space, and the first wall 31a may be connected to the second wall 31b by one or more film sections within the gap 31c.

[0098] As can be seen from FIG. 3, the first section 7 of the PVB is coplanar with the second section 9 of the PVB.

[0099] In the event of an impact in the direction of arrow 13, the laminated glazing 21 is prone to breakage in the area of ​​the barrier 31 because the gap 31c and / or the first and second walls 31a, 31b cause the laminated glazing 21 to behave substantially as two separated glass sheets 3, 5 rather than as laminated glazing in the area of ​​the barrier 31.

[0100] FIG. 4 shows a cross-sectional view of another laminated glazing 41 having substantially the same plan view as the laminated glazing 1 shown in FIG.

[0101] In Figure 4, a different barrier 51 is used to separate the first and second sections 7,9 of PVB used to bond the first and second glass sheets 3,5 together.

[0102] Figure 4 is provided in an exploded form for clarity. Accordingly, Figure 4 also shows that the first glass sheet 3 has a first major surface 3a and an opposite major surface 3b, and the second glass sheet 5 has a first major surface 5a and an opposite second major surface 5b. An intermediate film (labeled 10) comprises first and second sections 7, 9 of PVB between the first and second glass sheets 3, 5. The intermediate film 10 has a first major surface facing the second major surface 3b of the first glass sheet 3 and an opposite second major surface facing the first major surface 5a of the second glass sheet 5.

[0103] The first glass sheet 3 is the outer sheet of glass and the second glass sheet is the inner sheet of glass.

[0104] Using conventional nomenclature, the first major surface 3a of the first glass sheet 3 is "Surface 1" (or S1) of the laminated glazing 41. The second major surface 3b of the first glass sheet 3 is "Surface 2" (or S2) of the laminated glazing 41. The first major surface 5a is "Surface 3" (or S3) of the laminated glazing 41. The second major surface 5b of the second glass sheet 5 is "Surface 4" (or S4) of the laminated glazing 41. This same nomenclature applies to laminated glazings 1 and 21 discussed above.

[0105] As shown in Figure 4, in the laminated glazing 41, a first portion of the second major surface 3b of the first glass sheet 3 is covered by a first section 7 of PVB, and a second portion of the second major surface 3b of the first glass sheet 3 is covered by a second section 9 of PVB.

[0106] As is readily apparent from Figure 4, a first portion of the first major surface 5a of the second glass sheet 5 is also covered by a first section 7 of the PVB, and a second portion of the first major surface 5a of the second glass sheet 5 is also covered by a second section 9 of the PVB.

[0107] In the laminated glazing shown in Figure 4, the barrier 51 is similar to the barrier 31 of the laminated glazing 21, as it also has a double-wall structure.

[0108] The barrier 51 comprises a first tape 53 covering a first edge 7a of a first section 7 of PVB. The first tape 53 comprises a non-adhesive polymer strip such as PET having adhesive sections 53a, 53b extending along opposing edges on one surface.

[0109] The barrier 51 also includes a second tape 55 covering a first edge 9a of the second section 9 of PVB. The second tape 55 includes a non-adhesive polymer strip having adhesive sections 55a, 55b extending along opposing edges on one side. Conveniently, the first tape 53 is of the same type as the second tape 55 and can be cut from the same roll. Suitable tapes 53, 55 include riveter tapes, such as Riveter Tape 695 available from 3M™.

[0110] Although tape without adhesive areas could be used to cover the edges 7a, 9a of the first and second sections 7, 9 of PVB, the provision of adhesive areas 53a, 53b on tape 53 (and adhesive areas 55a, 55b on tape 55) simplifies assembly of the layers prior to lamination, as will be explained below with reference to Figure 5.

[0111] 4 and 5, prior to lamination, a first tape 53 is used to cover a first edge 7a of a first section 7 of PVB. The first tape 53 is positioned above edge 7a and then folded downward in the direction of arrow 56 to cover edge 7a so that a portion of the tape 53 contacts a first major surface 7b of the first section 7 of PVB. The adhesive section 53a then faces outward (i.e., away from the first major surface 7b) and can be used to form a seal with the second major surface 3b of the first glass sheet 3 when the first section 7 of PVB is placed onto the first glass sheet 3.

[0112] Similarly, tape 53 is folded downward in the direction of arrow 58 so that a portion of tape 53 contacts second major surface 7c of PVB first section 7. Adhesive section 53b then faces outward and can be used to form a seal with first major surface 5a of second glass sheet 5 when second glass sheet 5 is placed on intermediate film 10 prior to lamination.

[0113] A second tape 55 is applied in a similar manner to cover the edge 9a of the second section 9 of PVB.

[0114] As is readily apparent from Figure 5, the first edge 7a of the first section 7 of the PVB includes the minor surface between the first and second major surfaces 7b, 7c of the first section 7 of the PVB and the intersection of the minor surface with the first and second major surfaces 7b, 7c of the first section 7 of the PVB. Within the context of the present invention, the edge is defined accordingly.

[0115] Between the adhesive regions 53a, 53b of the first tape 53 is an adhesive-free region 53c. The second tape 55 is similarly configured. The adhesive-free regions of the tapes 53, 55 are positioned so that they face each other within the laminated glazing 41 so that they do not adhere to each other. When positioned within the laminated glazing 41, there may be a space between the adhesive-free regions of each tape 53, 55.

[0116] In an alternative embodiment, instead of adhesive-free area 53c, first tape 53 has a single adhesive area extending over its upper surface.

[0117] First tape 53 and / or second tape 55 may also include an adhesive area on the surface of the tape that faces first section 7 of the PVB when folded, an example of which is shown in phantom as layer 53d in Figure 5. Layer 53d may be divided into two adhesive areas in a manner similar to adhesive areas 53, 53b.

[0118] An obscuring band may be present on any of the major surfaces 3a, 3b, 5a, 5b to obscure the barrier 51 when the laminated glazing is viewed in the direction of arrows 43 or 45. Arrow 43 is perpendicular to the first major surface 3a and arrow 45 is perpendicular to the second major surface 5b. Preferably, the obscuring band is on the second major surface 3b and / or second major surface 5b.

[0119] As can be seen from FIG. 4, the first section 7 of the PVB is coplanar with the second section 9 of the PVB.

[0120] 6 shows a schematic view from the inside of a vehicle fitted with a windshield 100 according to the present invention, comprising first (outer) and second (inner) glass sheets joined together by an intermediate film 110 made up of a number of spaced apart sections, which are preferably all in the same plane, i.e. coplanar.

[0121] Windshield 100 is similar to that shown in Figures 1 and 2, except that instead of having two sections, the intermediate film that bonds the first and second glass sheets together has twelve spaced-apart sections of adhesive interlayer material (PVB in this example). The intermediate film of windshield 100 has a first section 101 of PVB that covers the central region of the windshield. Outside and around first section 101 are eleven smaller sections 103a-103k, each of PVB.

[0122] Each of the sections 101, 103a-103k are spaced apart from one another and separated by barriers, for example of the type described above with reference to FIGS.

[0123] When viewed from inside the vehicle, the PVB sections 103a, 103b are on the left side of the windshield 100.

[0124] Additionally, sections of PVB 103j and 103k are located on the right side of windshield 100, and sections of PVB 103c, 103d, 103e, 103f, 103g, 103h, and 103i are located on the lower side of windshield 100.

[0125] Although not shown in FIG. 6, the windshield 100 may include obscuring bands to hide the barrier between any or all of the sections of the PVB.

[0126] Figure 7 shows the arrangement of the first section 101 and eleven sections 103a-103k of intermediate film 110 between the inner and outer glass sheets of windshield 100. In this example, sections 101 and 103a-103k are all in the same plane. Figure 8 is an enlarged view of the left side of Figure 7.

[0127] 7 and 8, the first section of PVB 101 has a first edge 101' along the left side and a second edge 101'' along the underside.

[0128] The section of PVB 103a has a first edge 103a' and a second edge 103a''.

[0129] The section of PVB 103b has a first edge 103b', a second edge 103b'' and a third edge 103b'''.

[0130] In the laminated glazing 100, a first edge 101' of the first section 101 faces a first edge 103a' of the section 103a and a first edge 103b' of the section 103b.

[0131] The first edge 101' is separated from the first edge 103a' by at least a first space such that a first space exists between the first edge 101' and the first edge 103a'. Preferably, the first space extends along the entire first edge 103a'.

[0132] Because maintaining the first space between first edge 101' and first edge 103a' is difficult (i.e., during lamination, the adhesive interlayers may flow into each other, as described above), it is preferable to have a barrier between first edge 101' and first edge 103a' so that the barrier is at least partially within the first space. During the proper lamination process, the barrier prevents the PVB from first section 101 and / or section 103a from flowing and fusing together, thereby holding the individual sections together in the laminated glazing. Due to the flow of PVB during lamination, first edges 101' and 103a' are typically in direct contact with the barrier.

[0133] As shown in Figure 8, second edge 103a" of section 103a faces and points away from second edge 103b" of section 103b. As mentioned above, a barrier is preferably present between second edges 103a" and 103b".

[0134] 8 also shows that the third edge 103b''' of section 103b faces the first edge 103c' of section 103c. The portion of section 103c up to the first edge 103c' also faces a portion of the second edge 101'' of section 101.

[0135] A first edge 103d' of section 103d faces a second edge 101'' of section 101. A second edge 103c'' of section 103c faces a second edge 103d'' of section 103d.

[0136] As noted above, all edges are preferably separated by barriers.

[0137] For each section 101, 103a-103k, the barrier provided may have a configuration as described with respect to FIGS.

[0138] Next, a method for manufacturing laminated glazing according to the present invention will be described.

[0139] 2 and 9, a first glass sheet 3 is provided and placed flat on a horizontal table 120. A first section 7 of PVB is then provided and positioned on the first glass sheet 3 (in the direction of arrow 121) to cover a first portion of the upwardly facing major surface of the first glass sheet 3.

[0140] Next, a barrier 11 is provided, the barrier 11 being located adjacent to a first edge 7a of the first section 7 of PVB.

[0141] Next, a second section 9 of the PVB is prepared, and the second section 9 of the PVB is positioned on the upward major surface of the first glass sheet 3, covering a second portion thereof. A first edge 9a of the second section 9 of the PVB is positioned adjacent to the barrier 11. The first section 7 of the PVB is coplanar with the second section 9 of the PVB.

[0142] A second glass sheet 5 is then provided and positioned over the first and second sections 7, 9 of PVB and the barrier 11 to form an unlaminated stack.

[0143] The unlaminated stack is then laminated at a suitable elevated temperature and pressure to bond the first glass sheet 3 to the second glass sheet by the first and second sections 7, 9 of the PVB.

[0144] As will be readily apparent, as an alternative to the above method, the first and second sections 7, 9 of PVB may first be positioned on the first glass sheet to separate the edges 7a, 9a, and then the barrier 11 may be positioned in the space between the edges 7a, 9a.

[0145] The barrier 11 is made from a material that is capable of preventing sections 7, 9 of the PVB from fusing together during the lamination process. A suitable material is PET. The barrier may be compressible so that during the lamination process, the barrier is compressed between the first and second glass sheets 3, 5, thereby forming a seal that prevents flow of the PVB from section 7 to section 9 (and / or from section 9 to section 7). Suitable compressible materials for the barrier include elastomers, including elastomeric polymers and rubbers, such as silicone rubber.

[0146] Alternatively, the first and / or second sections 7, 9 may be made from a liquid resin that is subsequently hardened.

[0147] In such an alternative method, a suitable barrier may be provided around the periphery of the first glass sheet 3. The or each barrier may then be positioned on the first glass sheet to divide its major surface into the desired number of sections.

[0148] Next, pour the appropriate liquid resin into each empty section.

[0149] Finally, the second glass sheet 5 is placed on top. The liquid resin in the section surrounded by the barrier hardens to provide a section of intermediate film, bonding the first glass sheet 3 to the second glass sheet 5. A suitable pourable liquid resin is UVEKOL®.

[0150] However, it is preferred to use sections of adhesive interlayer material that are in sheet form prior to lamination.

[0151] In a preferred embodiment, the present invention provides laminated glazing having two glass sheets joined by an intermediate film comprising at least two sections. The sections are spaced apart within the laminated glazing, and at least a first edge of a first section of the intermediate film faces at least a first edge of a second section of the intermediate film such that at least a first space exists between the first edge of the first section and the first edge of the second section. The first space may be at least partially filled by a barrier that prevents the first and second sections from being joined together during a suitable lamination process used to make the laminated glazing.

[0152] In contrast to using an intermediate film that is a single sheet of adhesive interlayer material bonding the first and second glass sheets together, first and second spaced apart sections of the intermediate film are used instead. The spaced apart area between the first and second sections of the intermediate film introduces a weakness in the laminated glazing such that upon impact with the laminated glazing, the laminated glazing is fragile, particularly near the weakness, and the laminated glazing may break more easily compared to when a single sheet of adhesive interlayer material is used to bond the first and second glass sheets together, and the single sheet of adhesive interlayer material is coextensive with the first and second glass sheets.

[0153] Also, as is known from US Patent Application Publication Nos. 2005 / 0175844 and 2006 / 0138798 A1, the glass sheets of laminated glazing may be provided with one or more points of weakness that weaken the laminated glazing in the event of a collision. Such points of weakness may be provided in the laminated glazing according to the present invention and may be located so as to coincide with the barrier, i.e., so as to be aligned near or at the area of ​​the or each glass pane opposite the barrier.

[0154] The invention finds particular application as a windscreen for a vehicle such as a car, lorry, truck or bus.

Claims

1. 1. Laminated glazing for a vehicle windshield, comprising a first sheet of glazing material joined to a second sheet of glazing material by an intermediate film, each of the first and second sheets of glazing material having a respective first major surface and an opposite second major surface; the laminated glazing is positioned such that the second major surface of the first sheet of glazing material faces the first major surface of the second sheet of glazing material and the intermediate film is between the first and second sheets of glazing material; the intermediate film comprising a first section of adhesive interlayer material and a second section of adhesive interlayer material; the first section of the intermediate film extends over a first portion of the second major surface of the first sheet of glazing material and the second section of the intermediate film extends over a second portion of the second major surface of the first sheet of glazing material; the first and second sections of the intermediate film are positioned such that a first edge of the first section of the intermediate film faces a first edge of the second section of the intermediate film; further, the first edge of the first section of the intermediate film is spaced from the first edge of the second section of the intermediate film; a barrier positioned between the first edge of the first section of the intermediate film and the first edge of the second section of the intermediate film; the barrier comprises a first wall facing the first edge of the first section of the intermediate film and a second wall facing the first edge of the second section of the intermediate film; further, the first wall of the barrier is separated from the second wall of the barrier by a first gap. Laminated glazing for vehicle windshields.

2. 10. The laminated glazing of claim 1, wherein a barrier is in the entire space between the first edge of the first section of the intermediate film and the first edge of the second section of the intermediate film.

3. 3. Laminated glazing according to claim 1 or claim 2, wherein the barrier comprises a first tape covering the first edge of the first section of the intermediate film.

4. 4. Laminated glazing according to any one of claims 1 to 3, wherein the barrier comprises a second tape covering the first edge of the second section of the intermediate film.

5. 5. A laminated glazing according to any one of claims 1 to 4, wherein the barrier forms a seal with the second major surface of the first sheet of glazing material and / or the first major surface of the second sheet of glazing material.

6. 6. The laminated glazing of claim 5, wherein the barrier is compressible.

7. 7. The laminated glazing of claim 5 or 6, wherein the barrier comprises an elastomeric material.

8. 5. Laminated glazing according to any one of claims 1 to 4, wherein the barrier comprises polyethylene terephthalate or polycarbonate.

9. 9. The laminated glazing of claim 1, wherein the intermediate film comprises a third section, the third section of the intermediate film having a first edge, the third section of the intermediate film being spaced apart from the first and second sections, and the first edge of the third section of the intermediate film facing the first edge of the first section of the intermediate film or the second edge of the first section of the intermediate film.

10. 10. The laminated glazing of claim 9, wherein the first edge of the first section of the intermediate film and the second edge of the first section of the intermediate film extend along opposite sides of the first section of the intermediate film, or the first and second edges of the first section of the intermediate film intersect to form a corner portion of the first section of the intermediate film.

11. the intermediate film includes a third section having a first edge and a second edge, the second sections of the intermediate film each having a second edge; 9. A laminated glazing according to any one of claims 1 to 8, wherein the third section of the intermediate film is spaced apart from the second section of the intermediate film and the second edge of the second section of the intermediate film faces the second edge of the third section of the intermediate film.

12. 12. The laminated glazing of claim 11, comprising a third barrier between the second edge of the second section of the intermediate film and the second edge of the third section of the intermediate film.

13. 13. The laminated glazing of claim 1, wherein the intermediate film comprises a plurality of other sections of adhesive interlayer material, each of the plurality of other sections of the intermediate film having a respective first edge and spaced apart from the first and second sections of the intermediate film, and wherein at least one of the plurality of other sections is positioned such that its respective first edge faces the first edge of the first section of the intermediate film.

14. Laminated glazing as described in claim 13, wherein a first edge of each of the plurality of other sections of the intermediate film faces the first edge of the first section of the intermediate film.

15. 15. Laminated glazing as described in claim 13 or claim 14, further comprising a barrier between the first edge of the first section of the intermediate film and the first edge of the or each of the plurality of other sections of the intermediate film.

16. 16. The laminated glazing of claim 1, wherein the intermediate film comprises a plurality of other sections of adhesive interlayer material, each of the plurality of other sections of the intermediate film having a first edge and spaced apart from the first and second sections of the intermediate film, and wherein at least one of the plurality of other sections is positioned such that its respective first edge faces the second edge of the first section of the intermediate film.

17. A laminated glazing as described in claim 16, wherein the first edge of each of the plurality of other sections of the intermediate film faces the second edge of the first section of the intermediate film.

18. 18. Laminated glazing as described in claim 16 or claim 17, further comprising a barrier between the second edge of the first section of the intermediate film and the first edge of the or each of the plurality of other sections of the intermediate film.

19. 19. A laminated glazing as claimed in any one of claims 16 to 18, wherein at least one of the plurality of other sections is positioned such that the first edge of each of the other sections faces the third edge of the first section of the intermediate film.

20. A laminated glazing as described in claim 19, wherein a barrier exists between the third edge of the first section of the intermediate film and the first edge of at least one of the plurality of other sections of the intermediate film.

21. 21. A laminated glazing as claimed in any one of claims 13 to 20, wherein each section of the plurality of other sections has a second edge, and two of the plurality of other sections are arranged with their respective second edges facing each other and with a barrier between them.

22. 22. Laminated glazing according to any one of claims 1 to 21, wherein the first and / or second sheets of glazing material comprise one or more points or lines of weakness arranged to weaken the laminated glazing in the event of a collision.

23. 23. Laminated glazing according to claim 22, wherein the points or lines of weakness are on a major surface of the first and / or second sheets of glazing material.

24. 24. Laminated glazing according to claim 22 or claim 23, wherein the point or line of weakness is aligned with the first edge of or the space between the first or second section of the intermediate film.

25. 25. Laminated glazing according to any one of claims 1 to 24, further comprising an obscuring band on at least a portion of the first and / or second major surfaces of the first and / or second sheets of glazing material.

26. 26. The laminated glazing of claim 25, wherein the obscuring band covers at least a portion of the first edge of the first and / or second section and, when present, covers at least a portion of the barrier between the first edges of the first and / or second sections of the intermediate film.

27. 27. Laminated glazing according to any one of claims 1 to 26, wherein the first and / or second section of the intermediate film comprises polyvinyl butyral (PVB), sound-absorbing modified PVB, ethylene vinyl acetate (EVA), copolymers of ethylene, polyurethane (PU), polyvinyl chloride (PVC), copolymers of ethylene and methacrylic acid (EMA) or Uvekol (a liquid curable resin).

28. 28. A vehicle windshield comprising a laminated glazing according to any one of claims 1 to 27.

29. 29. A vehicle comprising the vehicle windshield of claim 28.

30. 28. Use of a laminated glazing according to any one of claims 1 to 27 as a windscreen for a vehicle to reduce the likelihood of injury to persons involved in a collision with the vehicle.

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