MXPA00008243A - Anti-laceration glazing - Google Patents

Abstract

The invention concerns the use of a laminated glazing consisting of two glass sheets linked via an adhesive coating insert more than 0.76 mm thick, as anti-laceration glazing.

Description

ENCRISTALADO ANTI-LACERACIÓN Description of the invention The invention belongs to the encristalados domain and in particular is related to the protection of people who are in proximity of a glazing when it is broken. In the case of the automobile, significant efforts have been made to date to adapt the structure of glazing and the nature of its building materials in a perspective of occupant protection. For this purpose, the different types of accidents likely to occur are the subject of simulations. One of the problems that has been clearly identified involves tempered monolithic encristalados, widely used as lateral glazing, mainly vertically mobile. In case of collision due to a collision, a rollover, etc., this type of glazing is broken into "a thousand pieces" by completely releasing the window opening. It has been studied that the expulsion of the occupants through this opening constitutes one of the most critical risks due to its frequency and the seriousness of its consequences, in particular the squashing of the occupant by the bodywork. In a desire to improve the safety conditions, one of the ways consists in replacing the tempered monolithic encristalados, of thicknesses in general at least equal to 3 mm, by encristalados in leaves constituted of two more or less tempered glass sheets or simply Annealed, of thicknesses approximately between 1 and 3 mm, that take in sandwich an intercalar adhesive, in general a layer of polyvinyl butyral (PVB) of 0.76 mm of thickness. A glazing of this type, when it breaks, is likely to remain in its place in the hole; nevertheless, pieces of glass, which retain their adhesion to the PVB, constitute a source of laceration, mainly in the upper part of the faces of the occupants. The sinking of the glazing towards the passenger compartment, which is mainly due to the folding of the elements of the bodywork or the frame that contains the glazing, constitutes, in this respect, in a very understandable way, a circumstance that is even more aggravating that occurs with the formation of profiles of glazing at sharper angles that penetrate the interior of the cabin or interior. In effect, certain pieces of broken glass located in proximity to such relatively sharp angles have sharp edges directed towards the occupants. It is very obviously intended to minimize as much as possible the laceration that affects the faces of the occupants. On the other hand, numerous anti-fracture and / or bulletproof and / or anti-shatter glazes are known which include at least three sheets of glass joined by various interlayer layers such as PVB, polyurethane (PU) of thicknesses greater than 0.76 m. In the context of the use of a sheet of glass-adhesive-glass as automobile side glazing mentioned above, the European patent application EP 0 418 123 Al describes the improvement of acoustic weakening properties, obtained by putting into operation a appropriate interlayer from 0.8 to 2.0 mm thick. This intercalar is a copolymer of vinyl chloride-glycidyl methacrylate; Certain thermoplastic PUs can also agree, the PVB is on the contrary avoided. The European patent application EP 0 816 064 A1 allegedly refers to the same type of glazing with maintenance of satisfactory mechanical properties, mainly with regard to resistance to bending. The putting into operation of the thin glass sheets, of approximately equal thickness of 0.5 mm, is made possible by the use of particular, relatively hard intercalary, having a Young's modulus at least equal to 20 MPa, such as an ionomeric resin , certain polyurethanes, certain polyesters of poly (ethylene terephthalate), certain acrylic resins. Unexpectedly, the inventors have realized that the increase in the thickness of the intercalar adhesive has the effect of decreasing the amplitude of the laceration phenomenon, in particular in the circumstances mentioned above. Accordingly, the invention has as its objective the use of a glazing essentially consisting of two sheets of glass joined by means of an interlayer adhesive layer thicker than 0.76 mm as glazing anti-laceration, mainly for cars and transport vehicles. According to the invention, the anti-laceration property is appreciated on mannequins according to the tests described in the publication "Pic ard J., Brereton P., He are A: An objective method of assessing laceration damage to facial tissues simulations - The Triple Laceration Index - Proceedings of the 17th conference - American Automobile Medicine Association 1973, pages 148-165". This publication defines a scale of laceration measurement between 0 and approximately 13 in practice, or even higher, observed on the head of a vinyl mannequin, covered with two calibrated leathers. The parameter taken, called TLI (for Triplex Laceration Index), is all the higher when the scratches, tears and other damages of the two leathers and the vinyl are numerous and deep at the end of the test. On the other hand, an anti-laceration effect against the air bags installed in the cabin has been observed as a secondary advantage, provided by the invention. This effect is manifested by a decrease in air bag punctures in the course of accidents and, finally, by a better efficiency of its operation. According to a preferred variant of the invention, the glazing is used as anti-laceration glazing in the non-integrated state or, in other words, as glazing that has anti-laceration properties against an occupant or a dummy that hits it when it It is already broken. It is easy to understand that the laceration is much more important in these conditions than when the occupant strikes a surface of the integral glazing that does not fragment immediately. A second variant of the invention, preferred to the preceding one, corresponds to the still more demanding conditions for measuring the anti-laceration property. It involves the use of a sheet glazing defined above, such as glazing • that has anti-laceration properties in the non-integrated and folded state. This variant refers particularly to the case of the encristalados mounted, in the context of experimentation, in a frame or frame articulated according to an axis at least; in the event of a collision from the outside of the vehicle, such a frame undergoes an angular deformation up to a predetermined minimum angle, a little less than 180 °, which causes the glazing to collapse over a short distance in the cabin. Longitudinally of the axis of articulation of the frame, the encristalado presents a vertex rounded in U or a edge in V, according to the case. When glazing is broken, pieces of glass located in proximity to the axis of articulation are all the more dangerous as their edges are directed towards a certain incident angle towards the occupants. By "glazing anti-laceration" in the sense of the invention, a glazing with substantially improved anti-laceration properties is designated in relation to those of a classical blade, mainly a lateral glazing for automobile where the TLI, measured under other extremely stringent conditions such as over the non-integrated and folded glazing, does not exceed 7 and particularly preferably 6. Advantageously, the thickness of the interlayer adhesive layer does not exceed 2 mm, even 1.90 mm or even 1.53 mm. In fact, the increase of this thickness to higher values does not provide a significant improvement of the antilaceration effect, but rather has as its main consequence a dulling and an increase in glazing. To constitute the interlayer, any plastic material usually used as an adhesive between two sheets of glass can be used, it being understood that the total thickness of the interlayer is greater than 0.76 mm. Polyvinyl butyral, polyurethane, mainly thermoplastic polyurethane, RIM polyurethane, polycarbonate, poly (methyl methacrylate), polypropylene, ethylene / vinyl acetate copolymer, cycloolefin copolymer, polyethylene mainly in the form of an ionomeric resin such as a copolymer of (meth) acrylic acid and ethylene, neutralized with a polyamine, thermoplastic polyester, mainly poly (ethylene terephthalate), unsaturated thermosettable polyester, optionally modified acrylic resin, vinyl chloride / glycidyl methacrylate copolymer. The interlayer adhesive layer may be constituted by a single layer based on one of these plastic materials, associated with the usual additives, in particular to the plasticizers in varying proportions. The standard PVB, as well as its "acoustic" degree, perfectly agree with other compositions that have excellent acoustic weakening properties, such as those described in the application EP 0 418 123 Al. According to an alternative, the layer Adhesive interlayer is constituted by a stack of thickness greater than 0.76 mm of several layers such as those to be defined. Stacks which have acoustic weakening properties, constituted for example by a layer of PVB or other material adapted to the present invention and of a layer of an acoustic resin, separated by a barrier film of poly (ethylene terephthalate), are particularly suitable. , as described in the European patent application EP 0 763 420 Al, the content of which is incorporated herein by reference. Advantageously, each of the two sheets of glass of the sheet glazing has a thickness comprised between 0.1 and 3 mm, in particular at least equal to 1.5 mm, and has a compressive stress in the core in the central zone, comprised between 1 and 50 MPa, advantageously at least equal to 20 MPa. The glass employed is float glass, more or less tempered, that is to say in the fully tempered state until simply annealed and, preferably, semi-tempered. According to a preferred embodiment, the invention also relates to the use of a sheet glazing comprising at least one functional layer. This may consist of one of the layers or sheets described above, obtained by the incorporation of the function sought in this layer or in this sheet, where the composition is chosen in a manner adapted for this purpose. It is also possible to treat a more or less thin layer or a film interposed between a glass sheet and the interlayer adhesive layer or between two layers constituting this intercalating adhesive, or even a layer or a functional film directly in contact with the ambient air, either that of the exterior or that of the vehicle cabin. A functional layer can consist of a hydrophobic / oleophobic layer, grafted in the form of a thin layer of thickness between 2 and 50 nm on the outer surface of a glass sheet, or unsupported by a plastic film such as a poly (fluoride) of vinyl) (PVF) or poly (vinylidene fluoride) (PVDF) applied on the outer surface of the glass sheet. The functional layer also comprises a decoration and / or masking layer, covering all or part of the glazing surface in sheets. This layer can, for example, replace the serigraphic decoration frequently placed on the periphery of the interior face of the glazing, mainly for motor vehicles, with the aim of masking, for an observer located on the outside of the vehicle, the elements of the bodywork which form the frame of the gap and the tail cord which is thus protected from degradation by ultraviolet radiation. This can include opaque or transparent colored decoration elements, which allow to make combined color elements to the bodywork or interior equipment, logos, etc. As other examples of functional layers, mention may be made of optically selective layers, consisting of stacks of layers that are distinguished by high transmission in the visible domain (wavelengths of 400 to 800 nm) and high absorption and / or reflection in the ultraviolet domain (<; 400 nm) and infrared (> 800 nm). These layers may consist of thin metallic layers, for example based on silver, of thicknesses comprised between 2 and 35 nm, separated from each other as well as from other adjacent layers or films, by dielectric layers of oxides or of indium nitrides, tin, silicon, zinc, titanium, tungsten, tantalum, niobium, aluminum, zirconium, etc., of thickness in general between 10 and 150 nm. These layers may include at least one colored layer in the dough. The set of these layers can be conductive of electricity; This can belong to the family of sunblind stacks, used to limit the contribution of heat by solar radiation in enclosed spaces or that of low-emissivity stacks, used on the contrary to limit the waste of heat in enclosed spaces, mainly due to a transmission of infrared radiation through glazing. Such stacks are described in patents FR 2 708 926 and EP 0 678 484. The functional layers are formed in a known manner by application of liquid precursors, according to the classical techniques of flow coating, tempering, liquid spraying or curtain, by pyrolysis or by evaporation according to techniques such as CVD (Chemical Vapor Deposition), plasma, optionally in vacuum. The decoration or masking layer (s) is or is provided on support films, mainly of plastic material, according to the techniques used in printing: screen printing, flexography, inkjet, laser printing, etc. The formation of optically selective stacks resorts to successive deposits by cathodic spraying, mainly aided by magnetic field or similar. In this regard, reference is again made to the patents FR 2 708 926 and EP 0 678 848. The formation of functional layers is achieved with the eventual application of a heating and / or a mainly ultraviolet radiation, according to the procedures of polymerization, sol-gel, crosslinking, etc. According to a particularly advantageous embodiment, the sheet glazing includes, on at least one of its outer faces, a sheet of plastic material. It is more particularly a sheet having the anti-laceration and, optionally, self-healing properties placed on the face of the glazing facing the vehicle cabin or the interior of the construction. A sheet of this type, made of plastic material, comprises, for example, a layer of thermoplastic polyurethane which serves for adhesion to the glass sheet, and an outer thermosetting polyurethane layer, that is to say in direct contact with the cabin atmosphere or of the interior of the construction; it is described in French patent FR 2 398 606, incorporated herein by reference, and improves the antilaceration properties of glazing. The use according to the invention more particularly considers automotive glazing and, preferably, any lateral glazing for fixed or mobile automobiles, for example vertically. A use as windshield and subsequent medallion can be considered as part of the invention by analogy, although the technical problem that this solves and, in particular the definition of the previous TLI, refers exclusively to the lateral encristalados for automobiles; similarly, a use as glazing of construction or base is also within the scope of the invention. The remarkable effect of the increase of the thickness of the interlayer over the antilaceration properties is now illustrated by the following examples.

EXAMPLE 1 The TLI (Triple Laceration Index), as defined above, is measured on the side glazing for automobiles, consisting of two layers of float glass 2.1 mm thick, sandwich-taking an interlayer layer of PVB of varying thickness. One of the glass sheets is simply annealed, that is, it has not been subjected to any tempering; the other has been partially tempered, to a degree corresponding to a surface stress or constraint of 45 ± 10 MPa, which is equivalent to a compressive stress in the core in the central area approximately equal to 22 ± 5 MPa. The measurement is made on a dummy that hits the broken glazing mounted on an articulated frame that has suffered an angular deformation corresponding to a collapse of the 75 mm glazing in the cabin at the level of the hinge axis. The glazing has a length of 600 mm and a width of 450 mm. The LTI measured is reported in the following table for each thickness of PVB and type of glass used.

For each type of glass, a linear interpolation of the TLI measurements is performed as a function of the PVB thickness and is represented in the single figure to which reference is made. The effect of the improvement of the antilaceration properties, in the occurrence on the broken, folded encristalado, procured by an increase of the thickness of intercalated PVB, is very visible. Under the same conditions, the TLI has been measured on three lateral automotive glazing constituted by two sheets of floated glass slightly hardened, that is to say that it has been subjected to a weak tempering, 1.1 mm thick, which adhere to each other by medium of a 2 mm thick interlayer. As the interlayer, a copolymer of acrylic acid and ethylene neutralized by a polyamine is chosen. The TLI reported are 3.8; 3.9; 4.1 corresponding to a remarkable level of antilaceration properties.

Claims (11)

1. The use of a glazing essentially consisting of two sheets of glass joined by means of an interlayer adhesive layer thicker than 0.76 mm as glazed anti-laceration.

2. The use of a sheet glazing according to claim 1, as glazing having anti-laceration properties in the non-integrated state.

3. The use of a sheet glazing according to claim 2, as glazing having anti-laceration properties in the non-integrated and folded state.

4. The use according to any of claims 1 to 3, characterized in that the thickness of the interlayer adhesive layer is at most equal to 2 mm, preferably 1.90 mm, mainly 1.53 mm.

5. The use according to any of claims 1 to 4, characterized in that the interlayer adhesive layer is constituted by one or several layers of plastic materials chosen from polyvinyl butyral, polyurethane, mainly thermoplastic polyurethane, RIM polyurethane, polycarbonate, poly (methyl methacrylate) ), polypropylene, ethylene / vinyl acetate copolymer, cycloolefin copolymer, polyethylene mainly in the form of an ionomeric resin such as an acid copolymer (meth) acrylic and ethylene, neutralized by a polyamine, thermoplastic polyester, mainly poly (ethylene terephthalate) unsaturated thermosetting polyester, optionally modified acrylic resin, vinyl chloride / glycidyl methacrylate copolymer.

6. The use according to any of claims 1 to 5, characterized in that each of the two layers of glass has a thickness comprised between 0.1 and 3 mm, preferably between 1.5 and 3 mm, and presents a compressive stress in the core in the central zone, between 1 and 50 MPa.

7. The use according to claim 6, characterized in that each of the two glass sheets has a compressive stress in the core in the central area at least equal to 20 MPa.

8. The use according to any of claims 1 to 7, characterized in that the sheet glazing comprises at least one functional layer.

9. The use according to any of claims 1 to 8, characterized in that at least one of the outer faces of the sheet glazing is constituted by a sheet of plastic material.

10. The use of glazing in sheets according to claim 1, as glazing for automobile.

11. The use of a glazing sheet according to claim 1, as side glazing for automobile.