Laminated glass sheet comprising peripheral steering elements made from polymer materials having

Abstract

The invention relates to:-a laminated glass sheet comprising a first glass sheet (1) forming the outer face of the glass sheet, the first glass sheet (1) being connected to a second glass sheet (3) by means of a first interlayer adhesive layer (2), the edge of the first glass sheet (1) being indented relative to the edge of the second glass sheet (3), the peripheral portion of the free surface of the first glass sheet (1), the edge face of the first glass sheet (1), the edge face of the first interlayer adhesive layer (2) and the surface portion of the second glass sheet (3) extending beyond the first glass sheet (1) describe a continuous stepped profile covered with stepped elements (7) in which an adhesive (6) is inserted, said stepped element (7) being made of a polymeric material, which may contain a reinforcing filler, exhibiting a water vapor permeability of at most equal to 5 g / m2 / day; a method for the production thereof; -its use (aeronautical engineering and the like).

Description

[0001] This application is a divisional application, the parent application being filed on December 3, 2019, with application number 201980005781.4 and the invention title being "Laminated Glass Plate Containing Peripheral Stepped Elements Made of Polymer Material with Desired Maximum Water Vapor Permeability". Technical Field

[0002] This invention relates to laminated glass sheets. Background Technology

[0003] Heated aircraft windshields are laminates of at least three inorganic and / or acrylic sheets (or layers), with the outermost layer serving as a carrier for heating (de-icing). These sheets are bonded together in pairs by interlayer adhesive layers such as polyvinyl butyral (PVB), thermoplastic polyurethane (TPU), ethylene / vinyl acetate (EVA), ionomers, etc. Moisture can penetrate the interlayer adhesive layers, particularly between the outer heating layer and its adjacent layers, causing malfunctions due to the following mechanisms: - Delamination; - Corrosion and oxidation of electrical connection components; - Electrolysis of heating layers such as tin-doped indium oxide (indium tin oxide - ITO) (induces layer rupture, which can lead to electric arcs near the layer); - Decolorization and turbidity of the interlayer; - Peripheral coloration resulting from the migration of tinting elements (e.g., those made from polysulfides) into the interlayer via adhesives / sealants.

[0004] Furthermore, since the outer layer is not used for the natural support of the system connecting to the aircraft (maintaining the two structural layers), the deformation of the glass plate caused by the aircraft pressure can lead to tearing and / or peripheral shearing mechanisms of the outer layer that promote delamination.

[0005] Water infiltration can be managed using different strategies: - Apply a few millimeters of sealing element on the periphery: usually a two-component polysulfide or polyurethane (PU) type; - The application uses stepped (or Z-shaped "z") metal (stainless steel, aluminum) peripheral elements that are bonded to the periphery of the laminated glass sheet, as will be seen later; this Z-bonded glass sheet is bonded to the laminated glass sheet and can be covered by, for example, hermetically and watertight seals made of silicone or equivalents, and "beads" (external seals made of polysulfides or equivalents) that provide aerodynamic continuity between the glass sheet and the aircraft structure and provide good inertness to aviation fluids (cleaning supplies, glycols (ground de-icing) etc.); in addition, these beads can significantly limit problems related to electric arcs and sparks, especially arc trapping and surface discharge.

[0006] The application of hermetic elements presents numerous challenges. This is because the implementation is extremely problematic due to the significant risk of optical defects arising from the need to install non-intercalated areas during lamination (maintaining the parallelism of the laminated material surfaces). Furthermore, the products used to manufacture hermetic elements exhibit poor moisture barrier properties, rendering this solution largely ineffective (particularly due to constraints associated with injection-based application methods).

[0007] In contrast, the application of stepped peripheral barrier elements, known as "Z" made of stainless steel (or sometimes aluminum), has greatly reduced moisture penetration and thus can eliminate the aforementioned failure modes to a very good degree.

[0008] On the other hand, the application of metal z has created new problems: - Increased risk of electrical insulation defects in heating system components; it specifies that, for the heating layer function, the cable runs horizontally between the outer and inner surfaces of the glass plate; - Discharges that cause noise, light and / or electromagnetic interference between z and the aircraft structure, or faulty connecting elements of the glass plate. - It induces surface discharge that dazzles the pilot; - The point that attracts lightning (the protrusion of the z-axis and the conductive properties of metals); - Weakening at the ends of silicone seals; - Reduce the cost of tooling equipment used for forming (e.g., by stamping) during short-term operation; - Complex management of z-glass plate shape tolerances; - It imparts good hardness to z and makes its geometry complex to manufacture; - The metallic nature of z leads to the (unnecessary) covering of it with a “barrier” usually made of polysulfides, which in turn requires maintenance because this barrier is susceptible to corrosion.

[0009] Therefore, the inventors sought to replace the metal z with z made of a polymer material, which can be formed, for example, by thermoforming. The polymer material has been selected to exhibit sufficient water vapor permeability to prevent degradation of the glass plate.

[0010] The specific permeability P is understood as representing the rate at which 1 mm of material permeates. The fluid is then expressed in g / m² / day·mm, representing the material's inherent barrier properties against water vapor.

[0011] The water vapor barrier performance of a given material or a given combination of materials (of a given thickness) is its permeability p, expressed in g / m² / day.

[0012] For a homogeneous material with thickness t, there exists a relationship p = P / t.

[0013] The inventors have been able to ensure water vapor tightness through peripheral stepped metallic elements (“z”) while overcoming problems related to their electrical conductivity and their manufacturing processes. In view of this, the subject of the present invention is a laminated glass plate comprising at least a first glass sheet forming the outer surface of the glass plate, the first glass sheet being connected to a second glass sheet by a first interlayer adhesive layer, wherein the edge of the first glass sheet is recessed relative to the edge of the second glass sheet, the peripheral portion of the free surface of the first glass sheet, the edge face of the first glass sheet, the edge face of the first interlayer adhesive layer, and the portion of the second glass sheet extending beyond the surface of the first glass sheet describe a continuous stepped profile, covered with stepped elements inserted with adhesive, characterized in that the stepped elements are made of a polymeric material capable of containing reinforcing fillers and exhibit a content of at most 5, and preferably 1 g / m³. 2 / day water vapor permeability.

[0014] Glass here is understood to mean inorganic glass such as soda-lime glass, aluminosilicate glass, etc., and plexiglass made of polymeric materials with transparent structures (common examples being poly(methyl methacrylate) (PMMA) and polycarbonate (PC)).

[0015] In reality, stepped metal elements do not allow any water vapor to permeate through their thickness, but there is a bypass path via the adhesive (polysulfide). Because stepped elements made of polymer materials have greater flexibility, it is possible to reduce the thickness of the adhesive and make these stepped elements comparable to bonded stepped metal elements in terms of water vapor permeability.

[0016] All the aforementioned electrical problems of stepped metal components are eliminated. Polymer materials are excellent electrical insulators.

[0017] also, Methods for processing polymer materials, such as thermoforming, are substantially less expensive than metal stamping; - Polymer materials are not susceptible to corrosion; - The polymer material exhibits flexibility, making the relative shape sensitivity of the stepped elements and laminated glass sheets easier to manage in production and limiting adhesive bonding stress that could cause the stepped elements to detach during use.

[0018] The adhesive includes, for example, polysulfides and / or polyurethane.

[0019] A stepped element is a single component or, optionally, a number of components.

[0020] Preferred characteristics of the laminated glass sheet according to the present invention: - The stepped element exhibits an elastic modulus of up to 5 GPa; it should be emphasized that it does not include polymers reinforced by reinforcing fibers (FRP fiber-reinforced polymers) (e.g., epoxide or unsaturated polyester type thermosetting resins), the reinforcement being caused by optionally woven relatively long fibers (e.g., glass or carbon fibers). - The polymer materials are selected from polyolefins (including polyethylene (PE), polypropylene (PP), or polyisobutylene (P-IB)) alone or as mixtures and / or copolymers of several of them, polyvinyl chloride and its derivatives (e.g., polyvinyl chloride (PVDC)), styrene polymers (e.g., polystyrene (PS), acrylonitrile / styrene / butadiene (ABS), styrene / acrylonitrile (SAN)), polyacrylic acids (including polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA)), polyesters (including polyethylene terephthalate (PET) and polybutylene terephthalate (PBT)), polyoxymethylene (POM), polyamide (PA), fluorinated polymers such as polytrifluoroethylene (PCTFE), polycarbonate (PC), aromatic polysulfones, including polysulfone (PSU), polyphenylene ether (PPE), polyurethane and polyurea (PU), and epoxides (EP); - Stepped elements are composed of several layers of the same or different polymer materials, which can be obtained, for example, by co-extrusion; - The polymer material contains short fibers and / or oriented layered reinforcing fillers; these fillers promote sufficiently low water vapor permeability; short glass or carbon fibers may be mentioned. - The stepped element has a thickness of up to 800 μm, preferably 300 μm; - The polymer material exhibits at least one surface treatment as follows: Better water vapor barrier performance: One or more dense oxides, such as SiO2 or Al2O3, deposited by chemical vapor deposition (CVD); Adhesive properties; - The adhesive has a thickness of at most 350 μm, preferably 200 μm; - The stepped element is covered with an airtight and watertight seal that protects against solar radiation and fluids; this seal is advantageously made of silicone or an equivalent. - The stepped element is covered with a protective strip that provides aerodynamic continuity between the laminated glass plate and the support structure, such as an aircraft structure, and good inertness to treatment fluids (such as aviation fluids, cleaning products, degreasers, glycols used for ground de-icing, etc.); this protective strip may be made of polysulfides or equivalents; - The laminated glass sheet includes at least a third glass sheet connected to the second glass sheet by a second interlayer adhesive layer; particularly in this configuration, the stepped element can extend beyond the continuous stepped profile defined above, thereby covering the entire thickness of the laminated glass sheet, including the edge surfaces of the second glass sheet, the second interlayer adhesive layer, and the third glass sheet; - The first glass sheet is made of inorganic glass having a thickness of 0.5 to 5 mm, preferably 2 to 4 mm, or of a polymeric material such as poly(methyl methacrylate) (PMMA) having a thickness of 0.5 to 5 mm. - The second and third glass sheets (if any) or even subsequent sheets are made of inorganic glass with a thickness of 4 to 10 mm, or of polymeric materials such as poly(methyl methacrylate) (PMMA) with a thickness of 5 to 30 mm, preferably up to 20 mm. - The interlayer adhesive layer is made of polyurethane (PU), polyvinyl butyral (PVB), ethylene / vinyl acetate (EVA), or equivalents, the first interlayer adhesive layer has a thickness of 3 to 10 mm, preferably 4 to 8 mm, and the second interlayer adhesive layer and subsequent layers (if any) have a thickness of 0.5 to 4 mm, preferably up to 2 mm.

[0021] Another aspect of this invention comprises a method for manufacturing the laminated glass sheet described above, characterized in that the stepped element is manufactured separately from its support structure via thermoforming, injection molding, injection molding and RIM (reaction injection molding), extrusion or co-extrusion, blow molding or compression / transfer. Conversely, it should be noted that the composite stepped element (glass fiber reinforced resin) formed directly on the laminated glass sheet is designed for good gas venting during the resin curing stage (crosslinking in an autoclave or vacuum bag). This good gas venting capability contradicts good moisture barrier properties (porosity). This stepped element is manufactured in single or multiple components by the method of this invention.

[0022] Another subject of the invention consists of the use of the laminated glass panels described above as glass panels for buildings, or glass panels for land, air, or water transportation vehicles, or for public facilities, especially for aircraft cockpit glass panels. Attached Figure Description

[0023] A better understanding of the present invention can be obtained from the following embodiments and with reference to the accompanying drawings, wherein: [ Figure 1 The first embodiment of the laminated glass plate of the present invention is illustrated by a cross-sectional view; [ Figure 2 A second embodiment of the laminated glass plate of the present invention is illustrated by a cross-sectional view; [ Figure 3 [Illustrated view] is a partial schematic view of a laminated glass plate according to the invention, supporting a specific interpretation related to the water vapor permeability of the stepped element (“z”) made of polymer material. Detailed Implementation

[0024] In these embodiments, the glass sheet refers to a chemically tempered aluminosilicate glass sheet sold by Saint-Gobain Sully under the registered trademark Solidion®.

[0025] about Figure 1 and 2 The laminated glass panel includes a first glass sheet 1 with a thickness of 3 mm forming the outer surface of the glass panel, which is bonded to a second glass sheet 3 with a thickness of 8 mm by a first interlayer adhesive layer 2 of polyvinyl butyral (PVB) with a thickness of 5.3 mm.

[0026] The third glass sheet 5, which is 8 mm thick, is bonded to the second glass sheet 3 by a second interlayer adhesive layer 4, which is 2 mm thick and made of polyvinyl butyral (PVB).

[0027] The edge of the first glass sheet 1 is recessed relative to the edge of the second glass sheet 3. The outer portion of the free surface of the first glass sheet 1, the edge face of the first glass sheet 1, the edge face of the first interlayer adhesive layer 2, and the portion of the second glass sheet 3 extending beyond the surface of the first glass sheet 1 describe a continuous stepped profile, which is covered with a stepped element 7 made of polyethylene terephthalate with a thickness of 355 μm.

[0028] The continuous stepped profile is covered with stepped elements 7 into which an adhesive 6 is inserted, the adhesive 6 having a thickness of 100 μm and being prepared from polysulfides.

[0029] - exist Figure 2 In the middle, the stepped element 7 is covered with a hermetically and watertight seal 8 made of silicone and a protective strip 9 made of polysulfide, which provides the laminated glass plate with aerodynamic continuity between the glass plate and the support structure, such as an aircraft structure, and good inertness to the processing fluid, as explained.

[0030] about Figure 1 and 2 The stepped element 7 can extend further than shown, thereby covering, for example, the entire peripheral edge of the laminated glass sheet, and in particular the edge surfaces of the second glass sheet 3, the second interlayer adhesive layer 4, and the third glass sheet 5.

[0031] about Figure 3 Regarding the stepped element 7, made of PET and bonded to the edge surface of the laminated glass plate, three types of moisture (water vapor) fluids should be considered: - A fluid containing an adhesive of thickness h1 flowing between the stepped element 7 and the first glass sheet 1; - A fluid containing an adhesive of thickness h2 flowing between the stepped element 7 and the second glass sheet 3; - Flowing through the stepped element 7 with a thickness of t z fluid; These three fluids diffuse into the first interlayer adhesive layer with a thickness H.

[0032] We can then introduce the concept of an equivalent barrier, corresponding to a hypothetical material with a precisely defined thickness covering the periphery of the glass plate. The water vapor permeation properties of this equivalent barrier are then defined as follows: [Mathematical Formula 1] For the four types of laminated glass structures specified below each table, the calculated p is recorded in the following table. eq The required values ​​and their results.

[0033] [Table 1] An example of an AIRBUS A320 (H=6.8mm) with metal z.

[0034] [Table 2] An example of an AIRBUS A320 (H=6.8mm) made of PET.

[0035] [Table 3] An example of an AIRBUS A350 (H=4.8mm) with metal z-axis.

[0036] [Table 4] An example of an AIRBUS A350 (H=4.8mm) with z-shape prepared from PET.

[0037] As shown in the comparisons of Tables 1 and 2 on the one hand and Tables 3 and 4 on the other, replacing the stepped metal element 7 with the stepped element 7 made of PET can reduce the concentration of PET by 0.87 g / m³ to 0.67 g / m³. 2 / day, and on the other hand, it decreased from 0.91 to 0.68g / m 2 / day penetration rate p.

[0038] This is because deformable polymer materials are easier to match the shape of the glass plate without being limited by the support. Their application can reduce the thickness of the adhesive from 500μm or 1mm to 100μm, thus reducing the permeability p value compared to metal z (stepped element) 7.

[0039] As expected, nonmetal z eliminates all the drawbacks associated with the conductivity of metals.

[0040] Polymer materials (especially those produced by thermoforming) are cheaper to manufacture than metals, particularly in tooling and equipment.

Claims

1. A laminated glass plate comprising at least a first glass sheet (1) forming an outer surface of the glass plate, the first glass sheet (1) being connected to a second glass sheet (3) by a first interlayer adhesive layer (2), wherein the edge of the first glass sheet (1) is recessed relative to the edge of the second glass sheet (3), the peripheral portion of the free surface of the first glass sheet (1), the edge face of the first glass sheet (1), the edge face of the first interlayer adhesive layer (2), and the portion of the second glass sheet (3) extending beyond the surface of the first glass sheet (1) describe a continuous stepped profile, covered with stepped elements (7) in which an adhesive (6) is inserted, characterized in that The stepped element (7) is made of a polymer material capable of containing reinforcing fillers and exhibits a maximum of 5 g / m³. 2 Water vapor permeability per day The polymeric materials mentioned herein are selected from styrene polymers, such as polystyrene (PS), acrylonitrile / styrene / butadiene (ABS), and styrene / acrylonitrile (SAN), either alone or as mixtures and / or copolymers thereof; polyacrylic acids, including polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA); polyoxymethylene (POM); polyamide (PA); fluorinated polymers, such as polychlorotrifluoroethylene (PCTFE); polycarbonate (PC); aromatic polysulfones, including polysulfone (PSU); polyphenylene ether (PPE); and epoxides (EP). The stepped element (7) has a thickness of at most 800 μm; and The adhesive (6) therein has a thickness of up to 350 μm.

2. The laminated glass plate according to claim 1, characterized in that... The stepped element (7) shows a maximum of 1 g / m³. 2 / day water vapor permeability.

3. The laminated glass sheet according to any one of the preceding claims, characterized in that... The stepped element (7) exhibits an elastic modulus of up to 5 GPa, excluding FRP (fiber-reinforced polymer).

4. The laminated glass sheet according to any one of the preceding claims, characterized in that... The stepped element (7) is composed of several layers of the same or different polymer materials.

5. The laminated glass sheet according to any one of the preceding claims, characterized in that... The polymer material contains short fibers and / or oriented layered reinforcing fillers.

6. The laminated glass sheet according to any one of the preceding claims, characterized in that... The stepped element (7) has a thickness of up to 300 μm.

7. The laminated glass sheet according to any one of the preceding claims, characterized in that... The polymer material exhibits at least one surface treatment as follows: Better water vapor barrier properties: one or more dense oxides, such as SiO2 or Al2O3, deposited by chemical vapor deposition (CVD); and / or Adhesive properties.

8. The laminated glass plate according to any one of the preceding claims, characterized in that... The adhesive (6) has a thickness of up to 200 μm.

9. The laminated glass plate according to any one of the preceding claims, characterized in that... The stepped element (7) is covered with airtight and watertight seals (8) to resist solar radiation and fluids.

10. The laminated glass plate according to any one of the preceding claims, characterized in that... The stepped element (7) is covered with a guard strip (9) which provides aerodynamic continuity between the laminated glass plate and the support structure, such as an aircraft structure, and good inertness to processing fluids such as aviation fluids, cleaning products, degreasers, diols used for ground de-icing, etc.

11. The laminated glass plate according to any one of the preceding claims, characterized in that... It includes at least a third glass sheet (5) connected to the second glass sheet (3) by a second interlayer adhesive layer (4).

12. The laminated glass plate according to any one of the preceding claims, characterized in that... The first glass sheet (1) is made of inorganic glass having a thickness of 0.5 to 5 mm, preferably 2 to 4 mm, or of a polymer material such as poly(methyl methacrylate) (PMMA) having a thickness of 0.5 to 5 mm.

13. The laminated glass plate according to any one of the preceding claims, characterized in that... The second glass sheet (3), and if present, the third glass sheet (5), or even subsequent sheets, are made of inorganic glass having a thickness of 4 to 10 mm, or of polymeric materials such as poly(methyl methacrylate) (PMMA) having a thickness of 5 to 30 mm, preferably up to 20 mm.

14. The laminated glass plate according to any one of the preceding claims, characterized in that... The interlayer adhesive layers (2; 4) are made of polyurethane (PU), polyvinyl butyral (PVB), ethylene / vinyl acetate (EVA) or equivalents, wherein the first interlayer adhesive layer (2) has a thickness of 3 to 10 mm, preferably 4 to 8 mm, and wherein the second interlayer adhesive layer (4) and, if any, subsequent layers have a thickness of 0.5 to 4 mm, preferably up to 2 mm.

15. A method for manufacturing a laminated glass plate according to any one of the preceding claims, characterized in that... The stepped element (7) is manufactured separately from its support structure by thermoforming, injection, injection molding, and RIM (reaction injection molding), extrusion or co-extrusion, blow molding or compression / transfer.

16. The laminated glass panel according to any one of claims 1 to 15 is used as a glass panel for buildings or for land, air or water transportation or for public facilities.

17. The use according to claim 16, for use as a glass panel in an aircraft cockpit.

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