EP3867208A1

EP3867208A1 - Laminated assembly

Info

Publication number: EP3867208A1
Application number: EP19783343.7A
Authority: EP
Inventors: Louis DELLIEU; Perrine LEYBROS; Antonella Contino; Thomas LAMBRICHT; Xavier GILLON
Original assignee: AGC Glass Europe SA
Current assignee: AGC Glass Europe SA
Priority date: 2018-10-21
Filing date: 2019-10-11
Publication date: 2021-08-25
Also published as: WO2020083669A1

Abstract

The present invention discloses a laminated assembly (10) comprising a glass sheet and a panel maintained together by a polymer interlayer. The glass sheet has a interdiffusion coefficient, D, of K+ into the glass matrix at 420°C is included in the range from 3.0 x10-15 m²/s to 20.0 x10-15 m²/s (3.0 x10-15 m²/s ≤ D ≤ 20.0 x10-15 m²/s), for a chemical tempering process of glass in a molten salt containing K and the glass sheet is chemically tempered.

Description

Laminated assembly

Technical Field

[0001] The present invention relates to Laminated assembly made to protect and/or to add functionalities to a panel, and in particular large size panels.

Background Art

[0002] Panels such as decorative signs, painted panels, pieces based on natural material,... can be damaged, scratched, peeled, attacked due to

manipulations, storage during handling, transport or upon the life cycle of the panel with rain, wind, snow, ice, chemicals,...

[0003] To avoid these problems, it is known to treat panels with a specific

treatment. Such treatments can be a protective paint, a stain, a lacquer and/or a chemical surface treatment.

[0004] Another way of protection is to add a layer on top of the panel such as plastic layer or an alumino-silicate glass to be as discrete as possible and then as thin as possible.

[0005] U.S. patent application Ser. No. 2009/0202808 discloses a alumino- silicate glass article used as a cover glass to protect an electronic devices such as such as cell phones, hand held games, MP3 players, watches, laptop computers, mobile GPS.

[0006] Alumino-silicate needs specific furnaces or specific processes. This kind of glass articles is expensive to produce and can be used only for small articles due to the price and difficulties to handle.

[0007] Another problem with alumino-silicate glass is the need to be chemically tempered to be used as a protection or a cover glass, to be handled and in order to have sufficient mechanical strength. This causes a large fragmentation of the glass and prevents the use once it is cracked meaning that the glass article exposes in a lot of very small glass pieces. This phenomena is due to the huge and deep interdiffusion coefficient of K+ into the glass matrix during the tempering process.

[0008] The reinforcement thanks to the chemical tempering process can be follow by the depth of layer (DOL), the exchange depth. DOL has to be higher than the deepest defect to avoid the opening of the crack. Another problem is that higher the surface compression is, higher is the internal tensile stress and higher is the fragmentation. Thus, the chemically tempered glass is exploding directly in very small fragments.

[0009] The chemical strengthening of a glass article is a heat induced ion- exchange, involving replacement of smaller alkali sodium ions in the surface layer of glass by larger ions, for example alkali potassium ions. Increased surface compression stress occurs in the glass as the larger ions“wedge” into the small sites formerly occupied by the sodium ions. Such a chemical treatment is generally carried out by immerging the glass in an ion-exchange molten bath containing one or more molten salt(s) of the larger ions, with a precise control of temperature and time.

Aluminosilicate-type glass compositions, such as for example those from the products range DragonTrail® from Asahi Glass Co. or those from the products range Gorilla® from Corning Inc., are also known to be very efficient for chemical tempering.

Summary of invention

[0010] It is an object of the present invention to alleviate these problems, and particularly to provide a laminated assembly which leads to protect a panel with a cost reduction and a compromise between an efficient mechanical reinforcement and a limited fragmentation to allow the use even if the glass is broken. Indeed, glass sheet brakes in larger fragments allowing to keep the transparency or the global aspect of the glass by keeping structural properties and avoiding penetration through the glass sheet.

[0011] According to a first aspect of the invention, the invention relates to an

improved laminated assembly comprising a chemically tempered glass sheet and a panel maintained together by a polymer interlayer.

[0012] The solution as defined in the first aspect of the present invention is based on that the glass sheet has a interdiffusion coefficient, D, of K+ into the glass matrix at 420°C is included in the range from 2.0 x10 ¹⁵ m²/s to 20.0 x10 ¹⁵ m²/s (2.0 x10 ¹⁵ m²/s < D < 20.0 x10 ¹⁵ m²/s), for a chemical tempering process of glass in a molten salt containing potassium, K. The molten salt can comprises KNO3 or KOH. Preferably, the interdiffusion coefficient is equal to or greater than 3.0 x10 ¹⁵ m²/s, more preferably 4.0 x10 ¹⁵ m²/s. Preferably, the interdiffusion coefficient is equal to or lower than 15.0 x10 ¹⁵ m²/s, more preferably 10.0 x10 ¹⁵ m²/s and much more preferably 8.0 x10-¹⁵ m²/s.

[0013] The interdiffusion coefficient, D, is calculated knowing the chemical

tempering time, t, and the ion exchange depth, d. The latter is measured either by Scanning Electron Microprobe on the polished section of the chemically tempered glass, or by optical diffractometric method on the face of the tempered glass, with equipment like FSM, a surface stress meter. Then the interdiffusion coefficient can be calculated as follows :

D [m²/s] = d² / 4 t

[0014] To determine the interdiffusion coefficient, D, the glass must be chemically tempered with a known temperature and a known duration, and the CS and DoL measured. If this glass is already tempered, the glass has to be polished to remove a depth higher than the exchange depth. Typically polishing more than 100 pm is enough. A after the polishing, the glass sheet has to be chemically tempered to determine the interdiffusion coefficient.

[0015] In one embodiment according to the invention, to have a discrete and light solution, the glass sheet has a thickness equal to or lower than 25 mm, preferably equal to or lower than 6 mm, more preferably equal to or lower than 3 mm.

[0016] In one embodiment according to the invention, to easily manipulate and handle the glass to assemble it to the panel, the glass sheet has a thickness equal to or greater than 0.1 mm, preferably equal to or greater than 0.2 mm, more preferably equal to or greater than 0.5 mm.

[0017] According to the invention, the panel can comprises a layer of material such as wood, metal, plastic, composite material or any other material that may need to be protected from scratches, chemical attacks, shocks while keeping the natural aesthetic such as veins for the wood, metallic, painted, ... aspect. [0018] The panel can be used to ensure the structural properties of the laminated assembly allowing to reduce the thickness of the glass sheet in order to reduce the weight of the assembly.

[0019] The panel can also be used as a decorative element or to give specific properties to the laminated assembly such as electrical conductivity, lighting functions or any other properties know by the skilled man in the art.

[0020] Preferably, the thickness of the layer of material is comprises between 0.1 mm to 50 cm meaning that the layer of material can be a thin slice of material but also can have a thick piece of material.

[0021] According to one embodiment of the invention, the layer of material is in contact with the polymer interlayer. Preferably, the face of the material that is laminated with the polymer interlayer is smooth to avoid bubbles and/or delamination. The roughness of this face is preferably at most 1 mm, more preferably at most 0.5 mm.

[0022] This layer of material can be treated, painted or any other known treatment for the used material. The face of the layer of material may have a specific surface aspect or have at least one recess and preferably several recess to allow the light passing through by keeping a specific decorative aspect in some embodiment, recesses can be holes meaning that holes pass through the layer of material.

[0023] In one embodiment, the panel comprises a metal-based plate and

preferably the metal-based plate comprises stainless-steel. More preferably, the metal-based plate is painted to protect chemically the metal-based plate and to ensure the adhesion between the polymer interlayer and the metal-based plate to avoid delamination. A metal-based plate even treated is easily scratched during the transport, the handling and/or during his life time. According to the invention, the panel is protected from these problems by the glass sheet.

[0024] In one embodiment according to the invention, the panel comprises one glass sheet. In this embodiment, the Laminated assembly comprises two glass sheets laminated together by a polymer interlayer and at least one glass sheet is chemically tempered and has a interdiffusion coefficient, D, of K+ into the glass matrix at 420°C is included in the range from 2.0 x10

¹⁵ m²/s to 20.0 x10-¹⁵ m²/s (2.0 x10 ¹⁵ m²/s < D < 20.0 x10-¹⁵ m²/s), for a chemical tempering process of glass in a molten salt containing

potassium. Preferably, the interdiffusion coefficient is greater than 3.0 x10- 1⁵ m²/s, more preferably 4.0 x10 ¹⁵ m²/s. Preferably, the interdiffusion coefficient is equal to or lower than 15.0 x10 ¹⁵ m²/s, more preferably 10.0 x10 ¹⁵ m²/s and much more preferably 8.0 x10 ¹⁵ m²/s.

[0025] In one embodiment according to the invention, the panel comprises n

glass sheets and n-1 polymer interlayers where n is a positive integer greater or equal to 2. Preferably, the positive integer n is equal to or lower than 7 (n < 7), preferably equal to or lower than 5 (n < 5); and more preferably equal to or lower than 3 (n < 3).

[0026] Glass sheets comprised in the panel can be chosen among all flat glass technologies, among them: float clear, extra-clear or coloured glass. The term“glass” is herein understood to mean any type of glass or equivalent transparent material, such as a mineral glass. The mineral glasses used may be irrespectively one or more known types of glass such as soda- lime-silica, aluminosilicate or borosilicate, crystalline and polycrystalline glasses. The glass pane can be obtained by a floating process, a drawing process, a rolling process or any other process known to manufacture a glass pane starting from a molten glass composition. The glass sheets can optionally be edge-ground. Edge grinding renders sharp edges into smooth edges which are much safer for people who could come in contact with the insulating glazing unit, in particular with the edge of the glazing.

[0027] In some embodiments of the present invention, films such as low

emissivity films, solar control films (a heat ray reflection films), anti- reflective films, anti-fog films, preferably a heat ray reflection film or a low emissivity film, can be provided on at least one face of at least one glass sheet of the laminated assembly.

[0028] In some embodiments of the present invention, at least one glass sheet of the laminated assembly can be at least partially etched or painted to give an additional aesthetic or decorative aspect to the laminated assembly. [0029] In some embodiments of the present invention, the glass sheet of the laminated assembly laminated with the panel can be a cast glass sheet meaning that the glass sheet has an external rough surface. The external surface is the non-laminated surface of the glass sheet.

[0030] In some embodiments of the present invention, at least one glass sheet of the panel is prestressed, preferably tempered and more preferably chemically tempered to reinforce the assembly.

[0031] By prestressed glass, it means a heat strengthened glass, a thermally toughened glass, or a chemically strengthened glass.

[0032] Heat strengthened glass is heat treated using a method of controlled

heating and cooling which places the glass surfaces under compression and the core of the glass under tension. This heat treatment method delivers a glass with a bending strength greater than annealed glass but less than thermally toughened safety glass.

[0033] Thermally toughened glass is heat treated using a method of controlled heating and cooling which puts the glass surface under compression and the core glass under tension. Such stresses cause the glass, when impacted, to break into small granular particles instead of splintering into jagged shards. The granular particles are less likely to injure occupants or damage objects.

[0034] In some embodiments according to the invention, at least one glass sheet of the panel has a interdiffusion coefficient of K+ into the glass matrix at 420°C is included in the range from 2.0 x10 ¹⁵ m²/s to 20.0 x10 ¹⁵ m²/s, for a chemical tempering process of glass in a molten salt containing potassium. Preferably, the interdiffusion coefficient is greater than 3.0 x10 ¹⁵ m²/s, more preferably 4.0 x10 ¹⁵ m²/s. Preferably, the interdiffusion coefficient is equal to or lower than 15.0 x10 ¹⁵ m²/s, more preferably 10.0 x10 ¹⁵ m²/s and much more preferably 8.0 x10 ¹⁵ m²/s.

[0035] In some embodiments according to the invention, at least one glass sheet of the panel has a thickness equal to or greater than 0.1 mm, preferably equal to or greater than 0.2 mm, more preferably equal to or greater than 0.5 mm and at least one glass sheet has a thickness equal to or lower than 25 mm, preferably equal to or lower than 6 mm, more preferably equal to or lower than 3 mm to easily manipulate and handle the glass to assemble it to the panel and to have a discrete and light laminated solution.

[0036] In some embodiments of the present invention, coatings such as low

emissivity coatings, solar control coatings (a heat ray reflection coatings), anti-reflective coatings, anti-fog coatings can be provided on the inner pane faces and/or outer pane face of the glass sheet or of the at least one glass sheet of the panel. The outer face is the face facing the outside of the laminated assembly.

[0037] The polymer interlayer to be used in the present invention typically

comprises a material selected from the group consisting ethylene vinyl acetate (EVA), polyisobutylene (PIB), polyvinyl butyral (PVB),

polyurethane (PU), polyvinyl chlorides (PVC), polyesters, copolyesters, polyacetals, cyclo olefin polymers (COP), ionomers and/or an ultraviolet activated adhesive, and others known in the art of manufacturing glass laminates. Blended materials using any compatible combinations of these materials can be suitable as well. In a preferred embodiment, the at least one polymer interlayer comprises a material selected from the group consisting of ethylene vinyl acetate, and/or polyvinyl butyral, more preferably polyvinyl butyral. The polymer interlayer is also designated as a “bonding interlayer” since the polymer interlayer and the glass pane form a bond that results in adhesion between the glass pane and the polymer interlayer.

[0038] In a preferred embodiment, the polymer interlayer to be used in the

present invention is a transparent or translucent polymer interlayer.

However, for decorative applications, the polymer interlayer may be coloured or patterned.

[0039] Typical thicknesses (measured in the direction normal to the plane, P) for the at least one polymer interlayer are 0.3 mm to 3.5 mm, preferably 0.75 mm to 1.75 mm. Commercially available polymer interlayers are polyvinyl butyral (PVB) layers of 0.38 mm, 0.76 mm, 1.52 mm, 2.28 m and 3.04 mm. To achieve the desired thickness, one or more of those layers can be used. [0040] To form the laminate glazing assembly of the present invention, polyvinyl butyral polymer interlayers are preferably used. Polyvinyl butyral (or PVB) is a resin known for applications that require strong binding, optical clarity, adhesion to many surfaces, toughness and flexibility. It is prepared from polyvinyl alcohol by reaction with butyraldehyde. Trade names for PVB- films include KB PVB, Saflex, GlasNovations, WINLITE, S-Lec, Trosifol and EVERLAM. The bonding process takes place under heat and pressure also designated as autoclave process which is well known in the art. When laminated under these conditions, the PVB interlayer becomes optically clear and binds the two panes of glass together. Once sealed together, the laminate behaves as a single unit and looks like normal glass. The polymer interlayer of PVB is tough and ductile, so brittle cracks will not pass from one side of the laminate to the other.

[0041] Another process known in the art and preferred for the present invention, is the autoclave free laminated glass production. This process reduces energy costs but has the drawback of limiting the types and thickness of polymer interlayer. Autoclave free oven makes preferentially EVA and dedicated PVB laminated glass. In such case, to achieve the desired thickness and security requirements, one or more of those autoclave free polymer interlayers can be used. The usual process for such autoclave free interlayers is the vacuum bag process.

[0042] According to the invention, an element can be embedded into the polymer interlayer. In some case, to avoid delamination several layers of polymer interlayers are needed to embed the element. The element can be a photovoltaic element, a thermochromic layer, a photochromic layer, a decorative element or any other element able to be embedded into the polymer interlayer.

[0043] In some embodiments according to the invention, the panel comprises a plastic element to give a light and rigid structural shape to the laminated assembly. This plastic element can be transparent, semi-transparent or non-transparent.

[0044] In a preferred embodiment, the plastic element is used as a skeleton with a specific 2- or 3-dimensional shape. The glass sheet completely conforms to the shape of the plastic element without any heating step and

assembled with the plastic interlayer to the plastic element.

[0045] In some embodiments, the plastic element is made of polycarbonate,

polymethyl methacrylate (PMMA), acrynolonitrile butadiene styrene (ABS), epoxy, nylon with or without fibers or any other suitable plastic material able to light and rigid structural shape to the laminated assembly.

[0046] It is noted that the invention relates to all possible combinations of features recited in the claims.

[0047] The following description relates to an architectural laminated assembly but it’s understood that the invention may be applicable to others fields like automotive, transportation, aviation, partition walls.

Brief description of drawings

[0048] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing various exemplifying embodiments of the invention which are provided by way of illustration and not of limitation. The drawings are a schematic

representation and not true to scale. The drawings do not restrict the invention in any way. More advantages will be explained with examples.

[0049] FIG. 1 is a schematic view of a laminated assembly according to an

exemplifying embodiment of the present invention.

[0050] FIG. 2 is a schematic view of a laminated assembly according to a second exemplifying embodiment of the present invention.

[0051] FIG. 1 is a schematic view of a laminated assembly according to a third exemplifying embodiment of the present invention.

Description of embodiments

[0052] With reference to FIG. 1 , a first embodiment of the present invention is described.

[0053] FIG. 1 shows a laminated assembly (10) comprising a chemically

tempered glass sheet (1), a polymer interlayer (2) and a panel (3). The glass sheet (1) has an external face (1a) and an internal face (1 b). The panel as at least two faces, a face to protect (3a) and second face (3b). The glass sheet (1) and the panel (3) are maintained together by the polymer interlayer (2). The internal face of the glass sheet (1b) is in contact with the polymer interlayer as the face to protect (3a).

[0054] In some embodiments related to Fig. 1 , the panel (3) is be a painted

metallic plate. During the transportation and the installation of this metallic plate, scratches can occur which can cause a shortening of the life cycle or a bad aesthetics. To protect the visible face of the metallic plate (3a), the glass sheet (1) is maintained by the polymer interlayer (2) on it (3). The visible face of the metallic plate (3a) is painted to ensure the adhesion with the polymer interlayer (2).

[0055] In one embodiment, the glass sheet has a thickness of at most 3 mm and the metallic plate has a thickness between 1 mm and 5 mm. The metallic plate is used also to ensure the structural properties of the laminated assembly (10). In this example, the glass sheet protects the metallic plate from exterior chemical and physical attacks such as water, wind, hard material,... This laminated assembly can be used as store signs.

[0056] In a preferred embodiment according to this example, the polymer

interlayer is an ethylene vinyl acetate or a polyvinyl butyral based material and more preferably to ensure the adhesion the polymer interlayer is an ethylene vinyl acetate based material.

[0057] In some embodiments related to Fig. 1 , the panel (3) comprises

photovoltaic and/or solar cells. Preferably, the chemically tempered glass sheet (1) has a interdiffusion coefficient of K+ into the glass matrix at 420°C is included in the range between 4.5 x10 ¹⁵ m²/s to 7.0 x10 ¹⁵ m²/s, for a chemical tempering process of glass in a molten salt containing potassium to prevent fragmentation of the glass sheet. The thickness of the glass sheet (1) is between 0.5 mm to 3 mm. The glass sheet (1) is used to protect cells from external attacks and is used as a structural element. Usually, hailstones can causes breakage of the cover glass of solar panels. Known solutions cannot well resist to hailstone due to fragmentation of the glass sheet used as a cover glass or know solutions needed very important thickness more than 6 mm and the assembly is then heavier than the solution according to the invention. Indeed, known cover glass sheets when a hailstone break them, the glass is broken in very small fragments. Due to these fragments the glass has no anymore structural properties and hailstone or others elements can pass through the glass and destroy cells. The glass sheet according to the invention brakes in large pieces then the broken glass sheet keep structural properties and continue to protect cells because pieces of broken glass are bigger than dimensions of cells and keep cells together. When the panel comprises photovoltaic or solar cells, in a preferred embodiment, the tempered glass sheet is textured or etched, at least on the external face (1a), to minimize the reflection of the light and to maximize the

transmission of the light to cells. The sun light hits the laminated assembly (10) on the external face (1a) of the glass sheet (1) passing through it to photovoltaic or solar cells, thus, light passes through the glass sheet and is absorbed by cells.

[0058] The assembly comprising cells can be mounted on a building roof, on

building fagade or can be used as independents assembly in solar farm for example.

[0059] With reference to FIG. 2, a second embodiment of the present invention is described.

[0060] FIG. 2 shows a laminated assembly (10) comprising a chemically

tempered glass sheet (1), a polymer interlayer (2) and a panel (3). The glass sheet (1) has an external face (1a) and an internal face (1 b). The panel as at least two faces, a face to protect (3a) and second face (3b). The glass sheet (1) and the panel (3) are maintained together by the polymer interlayer (2). The internal face of the glass sheet (1 b) is in contact with the polymer interlayer as the face to protect (3a).

[0061] The panel (3) comprises n glass sheets (4, 5) and n-1 polymer interlayer (6). In this non-limitative example, n is a positive integer equal to 2 (n = 2). The glass sheets (4, 5) of the panel (3) are laminated together by a polymer interlayer (6).

[0062] According to the invention, polymer interlayers can have different

compositions. In a preferred embodiment, polymer interlayers (2, 6) are polyvinyl butyral based material with same composition to facilitate to process of assembly.

[0063] According to the invention, glass sheets can have different compositions.

Glass sheets (4, 5) of the panel can have a different glass compositions and a different treatment.

[0064] In a one embodiment, the three glass sheets (1 , 4, and 5) have the same composition and are chemically tempered. Glass sheets of the laminated assembly have an interdiffusion coefficient of K+ into the glass matrix at 420°C is included in the range between 4.0 x10 ¹⁵ m²/s to 7.0 x10 ¹⁵ m²/s, for a chemical tempering process of glass in a molten salt containing potassium.

[0065] In a particular example, with reference of Fig. 2, the three glass sheets have a thickness of about 3 mm and the two polymer interlayers have a thickness of 0.76 mm. The three glass sheets have an interdiffusion coefficient of K+ into the glass matrix at 420°C of about 4.5 x10³ pm²/s, for a chemical tempering process of glass in a molten salt containing potassium. Preferably, glass sheets (1 , 4, and 5) of the laminated assembly (10) have a specific chemical composition to be produce in a float furnace and minimize the price of the glass sheets. Preferably, the chemical composition of the Ex11 of Table 1 is used to maximize the tempering process and reduce the fragmentation after the chemical tempering step.

[0066] Surprisingly, this particular example with three chemically tempered glass sheets shows high performances against explosion pressure with a very light assembly.

[0067] The current European standards dedicated to the security glazing

resistance against explosion pressure are provided in NBN EN 13541 (European Committee for Standardization EN 13541 , April 2012, ICS 13.230; 81.040.20). The pendant International ISO standards are the ISO 16934 with its alternative ISO 16933 (01 July 2007). According to the European standards, this example is classified ER3NS or ER4S. A known glazing with same performances regarding explosion resistance has a higher thickness. This example has a thickness of less than 10 mm where a known explosion resistance glazing has a thickness upper than 32 mm for an ER3NS glazing panel. Thus, a the example according to the invention is lighter than the known used glazing meaning that the building will be lighter, the transport and the handling will be easier.

[0068] Depending of the level of the classification needed to resist to explosion, the panel of the laminated assembly can have more glass sheets. To minimize the process of assembly, for the most of needed products, the number of glass sheets is limited to 7 sheets laminated together by plastic interlayers. In some embodiment, different plastic interlayers can be used to improve the laminated assembly or to give specific properties such as rigidity, light transmission, privacy,...

[0069] With reference to FIG. 3, a third embodiment of the present invention is described.

[0070] FIG. 3 shows a laminated assembly (100) comprising a chemically

tempered glass sheet (101), a polymer interlayer (102) and a panel (103). The glass sheet (101) has an external face (101a) and an internal face (101 b). The panel as at least two faces, a face to protect (103a) and second face (103b). The glass sheet (101) and the panel (103) are maintained together by the polymer interlayer (102). The internal face of the glass sheet (101 b) is in contact with the polymer interlayer as the face to protect (103a).

[0071] The panel (103) is a plastic skeleton with a specific 3-dimensional shape.

The glass sheet (101) completely conforms to the shape of the plastic element (103) without any heating step. The plastic interlayer maintained the glass sheet (101) on the plastic skeleton (103). This plastic skeleton can be mounted on a car body or on any other support in order to be integrated. In some embodiments, other elements such as display, touch function can be integrated to the laminated assembly on the plastic skeleton. In some embodiments, at least a hole can be made through the glass sheet into the plastic skeleton as for example a cup holder.

[0072] As a non-limiting examples, Table 1 shows some tempered during 8 hours glass sheet compositions having a interdiffusion coefficient, according to the invention, D, of K+ into the glass matrix at 420°Cis included in the range from 2.0 x10 ¹⁵ m²/s to 20.0 x10 ¹⁵ m²/s (2.0 x10 ¹⁵ m²/s < D < 20.0 x10 ¹⁵ m²/s), for a chemical tempering process of glass in a molten salt containing potassium. Preferably, the interdiffusion coefficient is greater than 3.0 x10 ¹⁵ m²/s, more preferably 4.0 x10 ¹⁵ m²/s. Preferably, the interdiffusion coefficient is equal to or lower than 15.0 x10 ¹⁵ m²/s, more preferably 10.0 x10 ¹⁵ m²/s and much more preferably 8.0 x10 ¹⁵ m²/s. The examples provided herein are illustrative of the scope of the invention defined in the claims. They do not in any way, represent limitative embodiments of the invention.

Ex 1 Ex 2 Ex 3 Ex 4 Ex 5 Ex 6

MgO 8,39 5,53 4,00 9,12 7,20 10,53

CaO 0,96 0,95 0,95 0 1,28 0

AI203 4,31 4,27 1,72 8,55 1,56 0

MgO/( 0,86 0,52 0,33 0,87 0,63 1,00 Excha 26,5 20 14,8 16,1 21,3 21,1

Coeff

13,30 7,58 4,15 4,91 8,59 8,43

(10³ .p

MgO 7,5 6,7 9,1 9,2 9,5

CaO 3 4,3 0,6 0,6 0,9

AI203 2 2,3 3 2,9 5,8

MgO/( 0,71 0,61 0,94 0,94 0,91

Excha 13,3 11,5 16,6 18,1 15,4

Coeff

3,35 2,50 5,22 6,2 4,49

(10³ .p

Table 1 - Examples of glass compositions

Claims

Claim 1. Laminated assembly (10) comprising a glass sheet (1 ) and a panel (3) maintained together by a polymer interlayer (2) characterized in that the glass sheet (1 ) has a interdiffusion coefficient, D, of K+ into the glass matrix at 420°C is included in the range from 2.0 x10 ¹⁵ m²/s to 20.0 x10 ¹⁵ m²/s (2.0 x10^_ ¹⁵ m²/s < D < 20.0 x10 ¹⁵ m²/s), for a chemical tempering process of glass in a molten salt containing K and in that the glass sheet is chemically tempered.

Claim 2. Laminated assembly (10) according to claim 1 wherein the glass sheet has a thickness equal to or greater than 0.1 mm, preferably equal to or greater than 0.2 mm, more preferably equal to or greater than 0.5 mm.

Claim 3. Laminated assembly (10) according to claim 1 or 2 wherein the glass sheet has a thickness equal to or lower than 25 mm, preferably equal to or lower than 6 mm, more preferably equal to or lower than 3 mm.

Claim 4. Laminated assembly (10) according to claims 1 to 3 wherein the

panel comprises a metal-based plate.

Claim 5. Laminated assembly (10) according to claim 4 wherein the metal- based plate comprises stainless-steel.

Claim 6. Laminated assembly (10) according to claims 1 to 3 wherein the

panel comprises a transparent material.

Claim 7. Laminated assembly (10) according to claims 1 to 3 wherein the

panel comprises one glass sheet.

Claim 8. Laminated assembly (10) according to claims 1 to 3 wherein the

panel comprises n glass sheets and n-1 polymer interlayers where n is a positive integer greater or equal to 2.

Claim 9. Laminated assembly (10) according to claim 8 wherein the positive integer n is equal to or lower than 7 (n < 7), preferably equal to or lower than 5 (n < 5); and more preferably equal to or lower than 3 (n < 3).

Claim 10. Laminated assembly (10) according to claims 7 to 9 wherein at least one glass sheet of the panel has a interdiffusion coefficient of K+ into the glass matrix at 420°C is included in the range from 3.0 x10 ¹⁵ to 20.0 x10 ¹⁵ m²/s, for a chemical tempering process of glass in a molten salt containing potassium.

Claim 1 1. Laminated assembly (10) according to claims 7 to 10 wherein at least one glass sheet of the panel has a thickness equal to or greater than

0.1 mm, preferably equal to or greater than 0.2 mm, more preferably equal to or greater than 0.5 mm.

Claim 12. Laminated assembly (10) according to claims 7 to 1 1 wherein at least one glass sheet has a thickness equal to or lower than 25 mm, preferably equal to or lower than 6 mm, more preferably equal to or lower than 3 mm.

Claim 13. Laminated assembly (10) according to claims 7 to 12 wherein at least one glass sheet of the panel is tempered and preferably chemically tempered.

Claim 14. Laminated assembly (10) according to claims 1 to 3 wherein the panel comprises a plastic element.

Claim 15. Laminated assembly according to any preceding claims, wherein the polymer interlayer is a material selected from the group consisting of ethylene vinyl acetate, polyisobutylene, polyvinyl butyral, polyurethane, cyclo olefin polymers, ionomer, a thermoplastic material, combinations thereof and/or ultraviolet activated adhesive, preferably is polyvinyl butyral.