GB2086263A

GB2086263A - Glued Panel Assemblies

Info

Publication number: GB2086263A
Application number: GB8130994A
Authority: GB
Original assignee: BFG Glassgroup GIE
Current assignee: BFG Glassgroup GIE
Priority date: 1980-10-21
Filing date: 1981-10-14
Publication date: 1982-05-12
Also published as: GB2086263B; FR2492478B1; FR2492478A1

Abstract

Panels adapted to be assembled by sticking to another component comprise a substrate bearing at least one heat-sensitive adhesive substance for securing the panel to the other component and at least one electrically conductive element which is adjacent the adhesive material and is adapted to supply the material with heat produced by the Joule effect in the conductive element.

Description

SPECIFICATION Glued Panel Assemblies The invention relates to a panel adapted to be assembled by sticking to another component, and a method of securing a substrate to another component by using an adhesive.

It is known to use various kinds of adhesive, and the user can choose in accordance with the final destination of the assembly. In some applications, however, it is not always possible to meet all operating requirements in satisfactory manner while maintaining the required properties after assembly.

Some existing kinds of adhesive, for example, have low viscosity at ambient temperature. Such adhesives are easy to apply and it is also easy to apply them to the coated panel, without substantial effort. On the other hand the coated panel is difficult to manipulate. In addition, the aforementioned kinds of adhesive take appreciable time to vulcanise or polymerize. It may thus be necessary to hold the panel in position until the adhesive becomes sufficiently rigid to secure the panel. Consequently this kind of adhesive is not suitable for installing panels in a production or assembly series, if high production rates are required.

In some applications, therefore, it is preferred to use adhesives having higher viscosity at ambient temperature. The coated panel is then easier to manipulate. However, the use of the last-mentioned adhesives results in difficulties when the panel is positioned. Presses, for example, are required for pressing the panel against the support. This additional operation, besides taking time, requires bulky apparatus and again is undesirable in large-scale manufacture.

In addition to the problems of manipulating adhesives and coated panels, allowance must be made for the constraints placed on the assembly when used. In the car sector, for example, the trend is to secure fixed windows to the vehicle body by sticking. The sticking point must preserve elastic and/or plastic properties so as to absorb deformation of the body without breaking the window. Adhesion must also be sufficient for the window, more particularly the windscreen, not to come loose from the vehicle in a collision.

It is not always easy to find adhesives which satisfactorily meet all these requirements.

On the other hand, during large-scale manufacture it is advantageous not to have to manipulate the panel after installing it.

In some cases, the panel must also be adapted for dismantling after installation. Such is the case, more particularly, with windows which have to be replaced after breaking. Dismantling may be very difficult.

The object of the invention is to provide a panel which at least partly obviates some of the aforementioned disadvantages.

The invention relates to a panel adapted to be secured by sticking to another component, characterised in that it comprises a substrate bearing at least one heat-sensitive adhesive substance for securing the panel to the other component and in that it comprises at least one electrically conductive element which is adjacent and preferably in surface contact with the adhes;ve material and is adapted to supply the material with heat produced by the Joule effect in the conductive element.

The panel according to the invention is simple to make. Since the conductive element is disposed adjacent the adhesive, the conductive element and the adhesive can be independently deposited, each by the appropriate method. It is thus unnecessary to secure the adhesive previously to a conductive element, as it would be if such element were incorporated in the adhesive, which latter procedure would require special apparatus, and would be applicable only to certain kinds of adhesive. Furthermore, the adhesive and the conductive element can be selected when deposited. When a panel is constructed according to the invention, therefore, use can be made of an adhesive adapted to the specifications imposed by the user. In short, the range of useable adhesives is widened. Some adhesives can be deposited in conventional manner, e.g. by an ordinary extruding machine of simple design.On the other hand, if the conductive element were not disposed adjacent the adhesive, a number of different adhesive/conductive element assemblies would have to be stored ready for use and choice of combinations would be limited.

The panel according to the invention is also easier to assemble to another component, since the conducting element is very accessible when the panel is being installed and no other manipulation is required afterwards. It is thus easy to introduce the assembly operation into large-scale manufacture. Access to the conductive element is also easy if the panel has to be taken out.

In some embodiments, the panel according to the invention has the further advantage of being ready to install, thus substantially reducing the amount of manipulation during installation.

The lastmentioned feature appreciably facilitates use of the panel in an assembly series or large-scale installation. The panel can be made at a different place from the assembly series and stored. The series is then supplied from the store as required and the panel can be assembled without much other preliminary treatment.

The panel according to the invention can comprise a substrate made up of various materials such as plastics or wood. However, according to a preferred embodiment of a panel according to the invention, the substrate comprises a glass sheet. The invention has been more particularly developed for this kind of substrate.

In the latter case the substrate can be an ordinary or hardened or laminated window adapted to be placed in a window opening or to be associated with another window to form a multiple window. Alternatively the substrate can be a sheet of glass associated with a sheet of plastics.

The invention also includes panels comprising one or more other components such as another glass sheet associated with the substrate, e.g. via a welded or stuck intermediate member so as to form a multiple panel adapted to be assembled by sticking to another component or adapted to be stuck in a frame.

In another embodiment the substrate can comprise a mirror adapted to be stuck e.g. to a wall of a building. The resulting panel forms a mirror ready for installation and having appreciable advantages, inter alia for large-scale installation.

As described hereinafter, the invention has been developed more particularly with regard to fixed motor-vehicle windows.

The conducting element may be manufactured in various ways. It can e.g. be constructed in the form of a thin strip applied to the adhesive so as e.g. to be placed perpendicular to the substrate.

When the adhesive is a self-supporting material such as a bead, a layer of conductive material can be deposited on the adhesive. In another embodiment, the conductive element can be applied or deposited on the substrate. It can e.g.

comprise one or more prefabricated conductors applied to the substrate on one or both sides of the adhesive or between the substrate and the adhesive.

In a preferred embodiment, the electrically conductive element comprises at least one coating deposited on the substrate. This feature is easier from the manufacturing point of view.

Of course, the amount of heat liberated by the conductive element must be adapted to the adhesive and to the type of substrate used.

Preferably, however, the coating will have a conductivity of at least 0.1 Siemens/m. This feature enables use to be made of an electric potential difference below 48 V, thus meeting safety standards in the sector while sufficiently heating the adhesive.

The conducted coating can be deposited on the substrate by various known methods. It can e.g.

be a conductive lacquer which is deposited by a brush or pneumatic pistol. Alternatively, it can be a conductive enamel which is baked or vitrified by heat.

Preferably, however, the coating is deposited by spraying a metal such as copper, aluminium or alloys thereof. This method is particularly easy, and is also well adapted to a coating deposited on a glass substrate. It can be used to obtain a coating which is very firmly attached to the substrate. The coating is also resistant to mechanical damage during subsequent handling, and is also resistant to heat produced in it.

This particular method has another appreciable advantage. When the conductive element is heated, it is usually oxidized to a certain extent. In the case of metal-coating in accordance with the preferred embodiment of the panel according to the invention, the surface of the conductive element in contact with the substrate undergoes little or no oxidation, and can thus inter alia preserve its aesthetic appearance.

The adhesive can be deposited directly on the substrate near the conductive coating or on either side thereof. Preferably, however, it is deposited on the conductive coating. This feature ensures good contact between the adhesive and the conductive element and optimum heat transfer to the adhesive. Furthermore, when the coating has been deposited by the preferred method of spraying a metal as previously mentioned, the roughness of the metal will substantially improve the adhesion of the adhesive. In such cases, furthermore, the conductive coating can be used as an embellishment so as to hide the adhesive when the panel is installed. The coating, in short, can have an aesthetic effect without the use of an external embellishment. Another result is a reduction in the amount of material used and consequently in the weight of the assembly.This advantage is particularly appreciated in the car industry. The resulting panel, therefore, is particularly advantageous since its conductive element solves both the aesthetic problem and the problem of heating the adhesive.

Of course, a coupling layer can be applied between the adhesive and the conductive coating, thus improving the adhesion of the adhesive to the coating.

Various kinds of adhesive can be used, inter alia vulcanizable, thermo-setting or polymerizable substances, e.g. polychloroprene, polyurethane and neoprene. Preferably, however, the adhesive is a thermoplastic. It is preferably chosen from among elastomers in the butyl family. By way of example, there is a particular advantage in using elastomers such as high molecular-weight polyisobutylenes, chlorobutyls which may or may not be mixed with low molecular-weight polyisobutylenes and isobutylene and isoprene copolymers. Elastomers in the butyl family have good sealing-tightness, among other properties.

Use can also be made of ethylene-propylenebased elastomers conventionally called E.P.D.M.

Thermoplastics in general, and more particularly those previously mentioned, are very advantageous for constructing a panel according to the invention, since they usuaily have relatively high viscosity at ambient temperature and are thus very easy to manipulate, without serious disadvantage. They are also relatively stable in time. The use of polyurethane, on the other hand, requires special precautions since it is very dirty.

Polyurethane is also sensitive to ultraviolet rays and thus deteriorates after a time.

In addition, since the conductive element heats the panel according to the invention, the viscosity of the thermoplastics therein can be substantially reduced during sticking, thus avoiding the use of complicated apparatus such as presses.

Thermoplastics are also particularly advantageous when the panel has to be subsequently dismantled, since in such cases it is sufficient to produce heat by the Joule effect in the conductive element in order to soften the adhesive and facilitate removal of the panel. This advantage is particularly important in the automobile industry, for example, where the garage mechanic is appreciably helped when replacing broken windscreens or other fixed windows, with regard to the removal of an old panel and replacement by a new. This advantage also applies to other sectors such as building.

In addition, as a result of the heat supplied by the conductive element, the surface tension of thermoplastics decreases and their adhesion to the receiving component during the assembly process can be improved by the wetting phenomenon. This applies particularly to butyl adhesives.

In order to optimize these various advantages of thermoplastics, it is preferable to use an adhesive having a Shore hardness A above 2 at 200C and below 1 at 600C. By use of a material of this kind, the maximum advantage can be obtained from the panel according to the invention, inter alia with regard to manipulation and assembly.

The conductive coating can be deposited on the substrate in a number of portions distributed over various parts of the substrate and/or in various configurations. The adhesive can be deposited at various localized regions on the conductive coating, whether continuous or discontinuous, for the purpose of e.g. spot sticking. Preferably, however, the conductive coating is deposited in a strip along the periphery of the substrate and the adhesive is deposited in at least one bead on the conductive coating.

By means of this feature, the panel can be efficiently secured to another component. It corresponds to the conventional method of manufacturing or assembling a double window or for securing the fixed windows in vehicles. The aforementioned conductive coating and bead system can also facilitate the removal of the panel, since the conductive coating is more accessible.

The conductive coating can be applied to the periphery of a single face of the substrate or it can be applied to the periphery of both faces and to its edge. If the conductive coating covers the edge of the substrate, the adhesive can be deposited on that part of the coating which covers the edge.

Preferably, however, the conductive coating is deposited on the periphery of at least one face of the substrate and extends onto at least part of an edge thereof, and the bead of adhesive material is deposited on the or a part of the coating disposed on the or a face of the substrate. It is particularly preferred to deposit the adhesive on electrically conductive material coated onto a substrate face which is an external face of the panel. Such embodiments are most convenient with regard to both the manufacture of the panel and the use thereof and facilitates access for supplying electricity during assembly or removal of the panel.

The advantages of the last mentioned embodiment of the invention can be realised by providing a bead or ribbon of heat-sensitive adhesive in combination with the coated substrate but not actually positioned on the conductive coating. In this case the adhesive can be positioned on the coating at the time when the substrate is to be assembled to another component by means of the adhesive.

Accordingly the invention includes a panel and mounting means combination characterised in that the panel comprises a substrate, e.g. a sheet of glass, having an electrically conductive coating which extends from a margin of at least one face of the substrate onto an edge thereof, and the mounting means comprises a bead or ribbon of heat-sensitive adhesive composition which has been or can be laid along a margin of the substrate in contact with said electrically conductive coating, leaving at least one portion of the electrically conductive coating exposed on an edge of the substrate so that such portion(s) can serve as a terminal via which the conductive coating can be connected to a source of EMF for heating such coating by Joule effect and thereby activating the adhesive in situ.

In such a panel and mounting means combination, the bead or ribbon of heat-sensitive adhesive composition can be protected, until it is used, by a protective covering, e.g. a covering strip or wrapper, which can be peeled off or otherwise removed from the adhesive when required.

In any such panel and mounting means combination any compatible feature or materials hereinbefore referred to can be used. For example: the panel can comprise a single sheet of glass or other material or it can comprise more than one sheet; the heat-sensitive material can be selected from the adhesives hereinbefore referred to; the electrically conductive coating can be and is preferably a metal coating. The coating can be made to extend onto the edge of the substrate either continuously or substantially continuously along the periphery, which is usually preferable, or it can extend onto such edge only at spaced e.g.

diametrically opposite locations or at locations on opposite sides of a micro-break in the conductive coating system. If the conductive coating has a micro-break at a certain spot, access to the conductive element is facilitated by partial deposition on the edge of the substrate, so that the element can be used as a dipole for receiving frequency-modulated radio waves.

The panel according to the invention can have various forms, inter alia can be flat or convex. It can e.g. be a single or multiple window for filling a glazed opening in a building or for being joined to another panel. Alternatively it can form the walls of an aquarium or various containers. Preferably, however, it constitutes a vehicle window, e.g. a windscreen, rear window or fixed side window.

The panel according to the invention, in short, is particularly suited to the car industry and to the manufacture of other kinds of vehicle. It can inter alia be used to avoid the difficult operation of fitting into an "H"-section joint. It is easy to work and does not require a complicated assembly installation. It can easily meet the tearing or wrenching standards in force in various countries.

In the USA, for example, the existing standards require that the windscreen must remain attached to the vehicle after striking a fixed obstacle at 25 mph. Sticking is the only method of assembly which can meet these conditions, and so the panel according to the invention solves this problem. In the case of a vehicle, it is particularly advantageous to facilitate removal of fixed windows in order to replace them. In a preferred embodiment of the panel according to the invention, using a thermoplastic as an adhesive, this condition is clearly fulfilled. In addition, the conductive coating can itself serve as an embellishment without the need fora subsequent component for this purpose, thus reducing the weight of the vehicle. In addition, the conductive coating can constitute a dipole for receiving radio waves.

The invention also relates to a method of securing a substrate to another component, using an adhesive, characterised in that at least one of the components in the assembly bears an electrically conductive element which can dissipate heat by the Joule effect and the adhesive material and the conductive element are placed together whereupon the adhesive is heated by the conductive element, the other components of the assembly being in contact or being placed in contact with the heated adhesive.

The method according to the invention is particularly advantageous since it can inter alia reduce the time required for assembly. Depending on the type of adhesive used, it can either reduce the polymerization or vulcanization time or can soften the adhesive so as to avoid complicated manipulation during assembly. In some embodiments, it can also be used to produce or increase the adhesion of the adhesive. It can also widen the choice of adhesives.

The method can therefore easily be adapted to large-scale manufacturing series.

The method according to the invention is advantageous when various elements are assembled, but is particularly applicable to the use of the aforementioned panels.

By means of the method according to the invention, multiple windows can easily be manufactured in the factory in a production series. Existing windows in a building or greenhouse can be doubled. Mirrors can be stuck to their support or any other element.

Preferably, however, the method according to the invention is characterised in that the substrate is a vehicle window and the other component is the part of the vehicle, e.g. strip, adapted to receive the window.

The method is used with particular advantage in the car industry, for reasons similar to those given hereinbefore with regard to the panel according to the invention.

In one embodiment of the method, the component for receiving the substrate is coated with an adhesive after which the substrate, provided with a conductive element, is pressed against the adhesive. The adhesive is then heated by Joule effect produced by a conductive element. More particularly, in an example where a windscreen is secured in the appropriate opening, the opening can be given a butyl bead. The windscreen, the edge of which has been metalcoated, is placed in position and the metal coating presses against the butyl bead. To secure the window, an electric current is conveyed through the coating.

For the reasons given previously, however, it is more advantageous to apply the method to a panel according to the invention.

The invention will now be described with reference to the accompanying diagrams, in which Fig. 1 (in continuous lines) shows a vertical section through a preferred embodiment of a panel according to the invention and Fig. 2 shows a section through a panel according to the invention secured to an existing pane.

A panel 1 comprises a substrate 2 consisting of a sheet of glass. An electrically conductive element 6 is disposed along the periphery of substrate 2. Its thickness can vary from 12 to 40 ,u and its electrical resistance from 2 to 5 ohm/m.

The conductive element is in the form of a continuous strip. If required, it can have a microbreak at any desired place on its periphery. If there is a micro-break, the conductive element can thus form a dipole for receiving radio waves.

As Fig. 1 also shows, the conductive element is deposited not only on the surface 3 of the substrate but also on its edge 4. The conductive element can be made to extend, e.g. to overflow onto the edge 4 of the substrate along the entire or substantially the entire periphery of the substrate. Alternatively, small localized deposits can be formed on the edge at diametrically opposite places or e.g. on either side of the aforementioned micro-break in the conductive element. This embodiment can be used to obtain small connecting lugs, which are accessible from the exterior when the panel is installed and can be used to supply electricity. A bead 7 of adhesive material is deposited on the conductive element 6, if required by using a securing layer applied on to the conductive element. The resulting panel 1 can be considered ready for installing. The adhesive can be protected by covering it with protective paper, e.g. silicone paper.

in Fig. 1, panel 1 is disposed in a groove 9 of another component 8 (shown by broken lines) such as a vehicle body. As before, the panel can be secured to component 8 via a securing layer if required. Advantageously, component 8 is formed with grooves 10 for receiving the excess adhesive.

The invention will be more clearly understood from the following practical examples, with reference to Fig. 1.

Example 1 In this Example, the substrate 2 was a laminated windscreen for Renault R14 motor vehicles. The windscreen periphery was coated with a continuous metal strip to obtain the conductive element 6. The metal coat was applied by using a flame pistol made by the Société Nouvelle de Metallisation Paris-France (S.N.M.). The metal sprayed on to the substrate was copper alloy having the following composition: Cu: 94%; Cr: 5%; Si: 1%. The width of the metallized strip on the window surface 3 was 18 mm. The edges of the window were likewise metal-coated. The thickness of the metallized strip was 22 4 and its ohmic resistance was 3 ohm/m, i.e. 0.33 Siemens/m.A thermoplastic bead 7, was deposited, without using a securing layer, on the strip 6 and had the following composition: Polyisobutylene LMMS ESSO 52 parts Isobutyleneisoprene copolymer 4 parts (Butyl 268 ESSO) Natural rubber 6 parts Carbon black F.E.F. 38 parts This thermoplastic joint had a Shore hardness Aof4to2O0C.

At 600C its Shore hardness A was less than 1.

The thermoplastic joint was protected by silicone pauper. The resulting panel was assembled as follows. The opening was cleaned and covered by a securing layer (Union Carbide A 1 87 in alcoholic solution). The silicone paper was removed and a potential difference of 36 V was applied for 13 minutes to the metallized strip, using 2 metal-plated copper terminals disposed at two diametrically opposite points. The glass was then pressed against the opening while the thermoplastic joint was hot. A press was used for this purpose. The assembly time was measured and found on average to be 5 minutes.For comparison, the time taken by other methods was measured, with the following results: Sticking by means of a cold butyl joint, using a press: 1 5 minutes Sticking by means of a cold polyurethane joint: 10 minutes Assembly by engagement, using an "H" section rubber joint: 7 minutes The adhesion was also measured, by the test described hereinafter.The following results were obtained: After application to the vehicle: R=2.5 kg/cm2 After aging: R=3 kg/cm2 By way of comparison, the following result is given by application by means of a butyl joint pressed when cold, the conventional method in the USA, measured under the same conditionse After application on the vehicle: R=1 kg/cm2 After aging: R=1.2 kg/cm2 Owing to the aesthetic effect of the resulting metallized strip round the windscreen, no external embellishment is required to hide the adhesive joint. The panel according to the invention saves appreciable weight.

The weight of adhesive for making the aforementioned windscreen was about 300 g, whereas for a windscreen having similar dimensions the weight of rubber and decorating means required for assembly by engagement is approx. 2.2 kg. The saving in weight is correspondingly greater if all the fixed windows in the vehicle are panels according to the invention.

One result can be to reduce the energy for driving the vehicle.

A laminated windscreen of the aforementioned kind was replaced in a garage in simple manner as follows. The inner glass sheet of the laminate was broken, so that the metallized strip had broken. A voltage of 24 V was applied for minutes to the edges of the conductive element, which had remained intact. Access to the conductive element was facilitated because the metal coating was applied not only to the surface but also to the edge of the glass. After 3 minutes, the thermoplastic joint heated by the conductive coating came loose from the vehicle body. The unstuck part of the joint was held by wedges and the non-softened joint was cut with a heated knife. If the conductive coating had remained intact, it would have been sufficient in this case to remove the window after the entire joint had sufficiently softened.

It is then only necessary to stick a new windscreen according to the invention in the opening in the same manner as previously described. The adhesive on the new window adheres easily to the adhesive remaining in the opening.

Example 2 A rear side panel was constructed for a Citroen CX 2000 motor vehicle. In this example, substrate 2 was a sheet of hardened glass. The conductive elements 6 was constructed in the same manner as in Example 1 except that the metal used was 99.6% aluminium. The adhesive 7 was a butyl joint having the following composition:- High molecular-weight polyisobutylene 48% LMMS: Low molecular-weight poly isobutylene (Butyl LM ESSO): 12% Escorez resin (Sob 8 ESSO): 8% Carbon black FEF 32% The thickness of the conductive coating was 20 mm and its ohmic resistance was 2.9 Q/metres, i.e. 0.35 Siemens/m.

An epoxy silane-based securing layer was used both on the conductive coating and on the opening in the vehicle. The panel was secured to the vehicle in the same manner as in Example 1.

The broken window was replaced as follows.

Since in the present example the substrate was a sheet of hardened glass, it was easy to reach the butyl joint and cut it with a heated knife after removing most of the fragments of glass as is conventionally done in garages. After all the pieces of glass had been removed, it was only necessary to apply a new glass in the same manner as in Example 1; the butyl in the replacement glass adhered easily to the butyl remaining in the opening. As a variant, the conductive element 6 was formed by depositing silver lacquer along the peripheral edges of the substrate. The lacquer cured during the operation of curving and hardening the window.

In Fig. 2, a panel 101 according to the invention comprises a substrate 102 in the form of a sheet of glass. Along the periphery of surface 103, the substrate bears an electrically conductive coating 106 on which an adhesive 107 is deposited. Coating 106 extends partly over the edge 104 of substrate 102 in order to give easy access to the conductive coating so that electricity can be supplied thereto. Panel 101 was pressed against another component 108 such as an existing window.

Example 3 A panel 101 as shown in Fig. 2 was constructed with a view to fitting it to the existing window in a greenhouse. The substrate 102 was a sheet of glass having a metal coating 106 along its periphery. The metal coat was a copper alloy as described in Example 1. A securing layer was applied to the conductive coating 106, and was covered with an adhesive 107 having the following composition.

Polyisobutylene LMMS: 52 parts Butyl 268 (Isobutylene-isoprene Copolymer): 8 parts Carbon black FEF 1 5 parts Levilite (Rhone Poulenc silica: 20 parts Molecular sieve: 5 parts The Shore hardness A at 200C of the aforementioned material was 6.

Panel 101 was placed on the existing greenhouse window as follows. Glass 108 was carefuily cleaned. Panel 101 was placed against glass 108, after which a voltage of 36 V was applied for 13 minutes at two diametrically opposite points on the conductive element 106 so as to raise its temperature slightly above 1000C. The applied voltage and the duration thereof depend of course on the dimensions of the panel.

Alternatively, the voltage can be applied to the coating before placing the panel 101 against glass 108.

Example 4 A double panel was constructed for use in a building. The panel 101 was similar to that in Example 3. In the present case, component 108 was a glass pane having edges metal-coated in the same manner as substrate 102. If required, a spacer can be placed between the two glass sheets so as to maintain a uniform spacing between them. The two parts were joined together without interposing a securing layer.

Next, a potential difference of 32 V was applied for 1 minute to each metallized strip. After cooling, the two glass sheets were secured to one another and formed a double window.

In another embodiment, the conductive element 106 comprised two spaced-apart metal plates disposed parallel to one another along the periphery of substrate 102. The adhesive 107 was deposited between the plates and in contact therewith. The same method of assembly was used as before.

Of course, the invention is in no way limited to the embodiments illustrated in the accompanying drawings or the cited examples. Numerous modifications can be made in the form, arrangement and construction of the elements used without departing from the scope of the invention as specified in the following claims.

The adhesion test mentioned hereinbefore is made as follows: A sheet of metal-coated glass is secured to a galvanized metal sheet painted with a layer of adhesive 2 mm thick. The adhesive surface is 4x 1.8 cm, i.e. 7.2 cm2. The resulting assembly is subjected to tensile force at a speed of 10 mm/min. The tensile force is recorded during the test. The maximum value reached by the force during the test is divided by the stuck area to give the adhesion stress.

Claims

1. A panel adapted to be assembled by sticking to another component, the panel being characterised in that it comprises a substrate (2, 102) bearing at least one heat-sensitive adhesive substance (7, 107) for securing the panel (1, 101) to the other component (8, 108) and in that it comprises at least one electrically conductive element (6, 106) which is adjacent the adhesive material and is adapted to supply the material with heat produced by the Joule effect in the .conductive element.

2. A panel according to claim 1, characterised in that the substrate comprises a glass sheet (2, 102).

3. A panel according to claim 1 or 2, characterised in that the electrically conductive element comprises at least one coating (6, 106) deposited on the substrate.

4. A panel according to claim 3, characterised in that the coating has a conductivity of at least 0.1 Siemens/m.

5. A panel according to claim 3 or 4, characterised in that the coating is deposited by spraying a metal such as copper, aluminium or alloys thereof.

6. A panel according to any of claims 3 to 5, characterised in that the adhesive material is deposited on the conductive coating.

7. A panel according to any of claims 1 to 6, characterised in that the adhesive material is a thermoplastic material, preferably chosen among elastomers in the butyl family.

8. A panel according to claim 7, characterised in that the thermoplastic material has a Shore hardness A above 2 at 200C and below 1 at 600 C.

9. A panel according to any of claims 6 to 8, characterised in that the conductive coating is deposited in the form of a strip along the periphery of the substrate and the adhesive material is deposited in the form of at least one bead (7, 107) on the conductive coating.

10. A panel according to claim 9, characterised in that the conductive coating is deposited on the periphery of at least one face (3, 103) of the substrate and extends onto at least one part of an edge (4, 104) thereof and the bead of adhesive material is deposited on the or a part of the coating which is disposed on the or a face of the substrate.

11. A panel according to claim 10, wherein the adhesive material is deposited on electrically conductive material coated onto a substrate face which is an external face of the panel.

1 2. A panel and mounting means combination characterised in that the panel comprises a substrate, e.g. a sheet of glass, having an electrically conductive coating which extends from a margin of at least one face of the substrate onto an edge thereof, and the mounting means comprises a bead or ribbon of heat-sensitive adhesive composition which has been or can be laid along a margin of the substrate in contact with said electrically conductive coating, leaving at least one portion of the electrically conductive coating exposed on an edge of the substrate so that such portion(s) can serve as a terminal via which the conductive coating can be connected to a source of EMF for heating such coating by Joule effect and thereby activating the adhesive in situ.

1 3. A panel and mounting means combination according to claim 12, wherein the bead or ribbon of adhesive composition is protected by a covering, e.g. a covering strip or wrapper, which can be peeled off or otherwise removed from the adhesive when it is required to mount the panel.

14. A panel and mounting means combination.

according to claim 12 or 1 3 and incorporating the feature(s) of any of claims 4 to 9 and 11.

1 5. A panel according to any of claims 1 to 14, characterised in that it comprises a vehicle window, e.g. a windscreen, a rear window or a fixed side window.

1 6. A method of securing a substrate to another component by means of an adhesive substance using e.g. a panel according to any of claims 1 to 15, characterised in that at least one of the elements (2, 7, 8, 102, 107, 108) used in the assembly process bears an electrically conductive element (6, 106) adapted to dissipate heat by the Joule effect and in that after the adhesive substance (7, 107) and the conductive element have been placed together, the adhesive is heated by the conductive element, the other components (2, 8, 102, 108) of the assembly being in contact or being placed in contact with the hot adhesive.

17. A method according to claim 16, characterised in that the substrate is a vehicle window and the other component is a part of the vehicle, e.g. a groove, rabbet (9, 109) or the like, adapted to receive the window.