LU85554A1 - PREFORMED GLAZING, AND METHOD FOR MANUFACTURING THE SAME - Google Patents

Description

The present invention relates to a transparent panel and a method for producing it. It relates more particularly to a transparent panel comprising a sheet of an optically transparent material, such as glass, and a joint of a polymeric material which is polymerized and hardened in situ to surround the peripheral edge of the sheet. The seal is typically formed by an injection and reaction molding process. The system can be shaped to form a vehicle windshield, for example, in which case it can be easily inserted to close a windshield opening surrounded by a frame of a suitable shape to cooperate with the system seal.

Initially, vehicle windshield systems were made up of a number of elements comprising adhesive obstructing compounds applied around the peripheral edges of the glass sheet, suitable mechanical fasteners, such as metal fasteners, and decorative framing strips arranged to cover the junction between the peripheral edges of the glass sheet and the adjacent part of the vehicle chassis.

Obviously, these structures are expensive both in terms of material and labor.

Next, transparent one-piece panels, of the type illustrated in United States Patent No. 4,072,340, were developed in an attempt to improve the structure. These transparent panels include a glass sheet, an adjacent frame, and a seal or liner of molded material, such as polyvinyl chloride, extending between the frame and the peripheral edge of the transparent element to hold the glass sheet together. and the frame. Fasteners are provided at a distance along the frame, so that the whole system can be guided in place over the opening of a chassis of a vehicle, in one piece, the fasteners passing through openings aligned in the vehicle chassis and being secured from inside the vehicle.

Other transparent panels, as illustrated in U.S. Patent No. 4,139,234, * include a gasket or trim molded around the edge of the glass panel, with fasteners molded into, and protruding from the joint or gasket for attachment to the chassis of a vehicle.

The relatively heavy frame elements of the foregoing systems, typically cast in zinc or other metals or alloys and / or the molded gasket or gasket to secure the frame to the transparent element gives significant weight to each transparent panel.

- Also, as illustrated in United States Patent No. 4,072,340, the decorative outer frame, which requires a means of attachment along its length to secure the assembly in a vehicle, requires costly techniques for the gasket or trim, making the frame elements expensive and time consuming to install.

In an attempt to reduce the overall weight of a transparent panel of the type discussed above, and to reduce its cost, other transparent panels of the general type illustrated in US Pat. Nos. Have been developed. 3,759,004 and 4,364,595, The structure of. first patent comprises a sheet of glass, the edge of which is surrounded by a framing strip, fixed in a suitably framed opening of a vehicle by means of an adhesive pressed between the glass and / or the framing strip and the adjacent part of the frame around. opening the vehicle. The framing strip is formed from a flexible plastic material with a hollow part which embraces the edge of the glass sheet, and a front part constituting a decorative strip which extends from and can be articulated on the edge of the front wall ΐ · 3 of the hollow part which is located on the internal side * of the framing strip when it is adjusted around the glass sheet. The framing strip can be held in place on the glass sheet by suitable retaining clips, of spring metal, for example.

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The second of the above-mentioned patents illustrates another transparent panel installed to close an opening of a vehicle, for example, in the form of a unit, preferably from the outside. The transparent panel comprises a glass sheet, a frame or decorative framing elements chosen from several types, surrounding the glass sheet, and one or more fastening elements fixed directly to the glass sheet, but hidden from view . Preferably, the attachment means are metal rods fixed firmly and rigidly directly to the surface of the glass by a suitable adhesive. The patent discloses that the decorative framing member can be injection molded around the glass sheet.

The invention relates to a transparent panel of comparatively low cost and weight, which can be assembled and installed in a vehicle with minimum handling cost.

The invention relates to a transparent panel or glazing and a method for manufacturing it, in which the material of the transparent element, typically a sheet of glass, carries a mounting element or gasket made of synthetic resin, which surrounds it, which surrounds the peripheral edge of the glass sheet. The mounting element or seal is applied to the periphery of the glass sheet by injecting into a molding cavity which surrounds the periphery of the glass sheet a composition which can polymerize and harden therein to produce the seal; by an autogenous mechanism resulting from its polymerization and hardening, the composition ensures, inside ί 4 the closed mold cavity, intimate contact with the walls which form the mold cavity, and with the glass sheet. Excellent results have been obtained by forming the mounting member into a polyurethane composition which hardens into a microcellular elastomer.

The process of the invention subjects the glass or other transparent sheet only to low pressures, and differs in this sense from the processes by which transparent panels with molded plastic frames have hitherto been produced, for example by molding by injection, a thermoplastic material such as polyvinyl chloride or the like being injected into contact with the surface of the material of the transparent element under extremely high pressures, typically in the range of 350 to 1400 kg / cm. In many cases, the preformed transparent panels include sheets of glass in which relatively small irregularities are formed during the manufacturing process. These irregularities are typically produced by the surface of the glass made up of areas in which the normally flat and flat shape is interrupted by a series of small undulations defined by a network of rapid, adjacent variations in the dimensions of the surface. In cases where this glass is used in the injection molding process, considerable breakage can be expected. The high pressures required in injection molding processes therefore require a substantially large pressure (clamp gauge) to hold the mold surface against the glass surface. Since the steel surfaces of the molds do not conform to the irregularities (and cannot be designed to do so, due to the non-repetitive nature of the irregularities), these high pressures frequently break the glass, particularly in the areas containing the irregularities. irregularities.

The preferred resins for use according to the invention are polyurethanes, preferably comprising diphenyl methane diisocyantes (MDI) and linear or weakly branched polypropylene glycol polyethers, which are slightly modified either by a carbodiimide or by reaction with glycols to give isocyanate compounds which are liquid at room temperature and have a viscosity sufficiently> low to meet the processing requirements of the feed system and high pressure mixing.

Resins are formulated to be polymerized when injected into the mold cavity, where polymerization and curing occur. The reactivity is controlled to ensure sufficient polymerization and stabilization of the cells, a relatively short residence time in the mold being sufficient for the production of the transparent panel. In this regard, although curing at room temperature is possible, the mold surfaces are typically maintained at 60 to 71 ° C, temperatures which laminated glass products can sustain.

It is an object of the invention to provide a preformed transparent panel comprising a sheet of glass or other transparent material and a wrapping molding of the type formed from a synthetic polymer, such as a polyurethane, which polymerizes to adhere in relation tight sealing with the adjacent surface of the glass, allowing the preformed assembly to be installed to close an opening of a vehicle or the like, with a minimum of manipulation.

Another object of the invention is to provide a preformed transparent panel which can be installed to close an opening, and be fixed without having to resort to accessory fixings and framing strips.

Another object of the invention is to provide a preformed transparent panel in which the external part 6 of a polymer / synthetic wrap molding is formed with an external framing part, intended to close the space between the surface exposed glass and the part of the vehicle or the like adjacent to the opening to be closed, to form an assembly, essentially flush.

In the drawings: FIG. 1 is a rear view of a preformed transparent panel according to the invention,

FIG. 2 is a fragmentary sectional view, on an enlarged scale, of the panel of FIG. 1, taken along line 2-2 thereof,

Figure 3 is a fragmentary sectional view, on an enlarged scale, of the peripheral edge of the panel. transparent of FIGS. 1 and 2, showing the application of a bead of adhesive before installing the panel,

FIG. 4 is a fragmentary vertical section view of the transparent panel of FIGS. 1, 2 and 3, after installation to close an opening,

FIG. 5 is a schematic view showing the preferred method for producing the preformed transparent panel of FIGS. 1 to 4,

FIG. 6 is a more detailed schematic view showing the basic components involved in the implementation of the method of FIG. 5,

FIG. 7 is a plan view of a typical mold designed to produce the preformed transparent panel of FIGS. 1 to 4,

FIG. 8 is a fragmentary sectional view, on an enlarged scale, of the mold structure of FIG. 7, taken along line 8-8 thereof,

FIG. 9 is a fragmentary sectional view, on an enlarged scale, of the suction part of the mold system of FIGS. 7 and 8, taken along the line 9-9 of FIG. 7, and

Figure 10 is a fragmentary sectional view, on an enlarged scale, showing the pads cooperating to support a glass article during the production of a panel according to the invention by the method of Figure 5; there are also mold cavities in the lower and upper sections.

According to the invention, a glazing unit is provided comprising a sheet of transparent material and a seal formed from a synthetic polymer adhering to predetermined parts of the sheet, characterized in that the seal has been polymerized in situ near the parts predetermined from the sheet and has taken by an autogenous mechanism arising from its polymerization and its setting in a confined state, intimate contact with the parts to which it adheres.

Also according to the invention, there is provided a method for producing an assembly formed of a transparent sheet material and of a seal adhering to its periphery, characterized in that it consists in a) positioning a transparent sheet material inside a mold cavity formed by several cooperating mold sections, the mold cavity having, with respect to the transparent sheet, the shape and position of the finished joint, and immediately surrounding the edge surfaces of the sheet adjacent to its periphery, b) injecting into the mold cavity a composition which can polymerize and harden to produce a joint and, when it has hardened in contact with them, adheres to the edge surfaces of the sheet material, c) order the pressure at which the composition is injected into the mold cavity so that it is low enough not to damage the sheet material, d) controlling the temperature of the mold cavity, the injection of the composite ion and the quantity of the composition injected so that the composition polymerized 8 after its injection and comes, by the autogenous pressure resulting from the polymerization, in intimate contact with the mold cavity and with the sheet material, and hardens during this contact, and e) removing the entire mold cavity.

Referring in more detail to the drawings, • Figures 1, 2, 3 and 4 show a preformed transparent panel according to the invention, produced by the process of the invention. More specifically, there is shown a preformed rear window 10 to be inserted into a suitable opening of a vehicle. The vehicle has a rear wall 12 which generally defines the opening to be closed. The rear wall 12 is typically formed from a stamped sheet, and is suitably fixed to a stiffening element 14, for example by electrical resistance welding. A wall portion 16 extends outwardly from the wall portion 12 and is typically integral therewith; with the wall part 12, it defines a cavity intended to receive the preformed transparent panel 10. The wall part 16 ends in a relatively steep fold; at this point, the material 18 is shaped, and is integral with the sheet defining the silhouette of the vehicle.

The preformed rear window system 10 comprises a suitably shaped transparent material 20, typically formed from an optically transparent glass sheet. A mounting element or seal, 22, made of synthetic resin, surrounds the front, rear and peripheral parts of the material 20. The bead or frame 24 of the seal 22, as best seen in FIG. 4, covers a space between the peripheral edge of the transparent material and the metal of the vehicle chassis which surrounds the opening, an example being the wall part 16 when the transparent panel 10 is installed on the vehicle.

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The part of the mounting element or seal 22 which extends towards the inside of the framing part 24 surrounds the peripheral edge and the rear edge of the material 20 of the transparent sheet and ends along its surface. back. A retaining element or rib 26 is also provided on the rear surface of the transparent material 20 and is spaced inward from the end of the mounting element or seal 22. The area between the end of the seal 22 and the rib 26 is provided to retain a bead of a suitable adhesive material used to mount the preformed transparent panel. In addition, there are provided lugs 28 integral with the seal 22 and the rib 26, and a bridge 30 between the seal 22 and the rib 26 and the lugs 28. The lugs 28 are useful means of positioning and location during mounting the system on a vehicle, and retaining the system in place until the adhesive sets to provide the desired connection between the preformed panel and the corresponding part of the vehicle.

The first stage of production of the rear window 10 involves perfect cleaning of the front, rear and peripheral edge of the glass sheet 20, to prepare the surfaces for adhesion of the mounting joint 22, the rib 26 and the tabs 28 associated. It has been found desirable in some cases to include a layer 32 of opaque paint, sintered enamel for glass or the like, on a portion of the back surface of the sheet 20. The opaque material of layer 32 is typically employed in cases where it is necessary to hide, from the outside, window mounting materials and structures, as well as, for example, wiper drive mechanisms, and in some cases where it is useful to provide protection against ultraviolet rays.

The next stage in the production of the rear window 10 consists in applying a base coating 10 to the surfaces of the glass previously cleaned. Satisfactory results have been obtained by initially using a layer 34 of a commercially available product under the designation "Betaseal, Glass Primer 435.18 Commercial Grade" from Essex Chemical Corporation, Clifton, New Jersey, E.U.A. The bonding area of the glass is first coated with the bottom coating to form the layer 34 which serves as a bonding agent. The material of the base layer is a clear, moisture-sensitive material comprising gamma-aminopropyltriethoxysilane, which promotes adhesion between other "Betaseal" products and glass.

After application of layer 34, a second base layer 36 is applied to layer 34. Satisfactory results have been obtained using a commercially available product under the designation "Betaseal, Glass Primer 435.20 Commercial Grade" from Essex Chemical Corporation . This material is a screen material preventing degradation by ultraviolet of polyurethane joints and adhesives, and facilitating the rapid formation of a stable hydrolytic bond between glass and urethane. Approximately 20 minutes after applying the superimposed layers 34 and 36, the system is placed in the mold cavity of a mold in which the seal 22, the rib 26 and the legs 28 made of polyurethane are produced; the mold is a part of the apparatus described below in detail in connection with FIGS. 5 to 10.

It is frequently desirable to apply a coating 38 to the exposed exterior surface of the gasket frame section 22, before installing the structure on a vehicle. Coating 38 may be a black urethane paint, such as that manufactured by PPG Industries, Inc., Pittsburg, Pennsylvania, E.U.A., under the designation "Purethane 700 HSE-848". The paint coating 38 is then cured 11 at approximately 60-71 ° C for about 20-30 minutes. Coating 38 is applied to protect the exposed material of the polyurethane seal from degradation that would otherwise result from exposure to the ultraviolet radiation normally present in unfiltered sunlight.

The preformed transparent panel can be installed in a suitable opening of a vehicle by applying a bead 40 of adhesive material, for example a urethane blocking compound such as that manufactured by Essex Chemical Corporation, designated by "Betaseal 551.2" with a water paste, on the rear peripheral surface between the joint 22 and the rib 26 apart, placing the panel in alignment with the opening of the vehicle, and pushing the panel into place. When the panel is aligned with the opening of the vehicle, the tabs 28 are aligned with cooperating spaced openings 42 in the rear wall 12 and the associated reinforcement element 14 of the vehicle. The legs 28 have tapered noses to facilitate alignment. When the panel is pushed into place, the tapered noses of the tabs 28 pass through the openings 42 and are caused to pinch in locked positions in which they maintain the bead of adhesive 40 in a compressed state (Figure 4). As soon as the adhesive 40 sets, the installation is complete.

Referring now to Figures 5 to 10, the apparatus for producing the panel 10 includes a station 50 for applying the base layer, and a station 52 for molding (Figure 5) which includes a bulk storage area 54 from which are supplied as necessary, to a station 56 for supplying urethane, a stream formed of a mixture of a polyol, of a chain extender, for example ethylene glycol, of a pigment and of a catalyst, and a separate stream of an isocyanate. The isocyanate from the bulk storage tank 54 is delivered to a conditioning tank 58, while the polyol blend is delivered to a tank 60. The outlets from tanks 58 and 60 communicate with displacement cylinders or pumps with high pressure flow rate 66 and 68, by recirculation pumps 62 and 64, for. maintain a flow of material at all times through the supply lines leading to a mixing head 74, and return it through the recirculation lines to the displacement cylinders 66 and 68. Heat exchangers 70 and 72 are used in the system to maintain the reagents at the desired temperature. Constant control of temperature and movement is essential to keep the various insoluble compounds in suspension at temperatures at which the reactants remain inert and liquid, but at which they will react quickly when put together.

An injection system is provided for injecting a charge composed of carefully controlled parts of the two streams circulating in the mold, with a uniform and regular flow. Measured charges of the two streams are delivered to the mixing head 74 from the outputs of the displacement cylinders 66 and 68, respectively, by the action of the pistons which are shown diagrammatically. The injection into the mixing head 74 is done by applying pressure in

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the range of approximately 70 to 210 kg / cm. The two streams are intimately mixed in the mixing head 74. The mixture is delivered therefrom to an associated mold 76 under a pressure of approximately 3.5 to 72 kg / cm. The mold is typically maintained at a temperature in the range of 60 to 66 ° C.

The mold 76 consists of a lower section 78 (FIG. 7) and an upper section 80. Suitable means, not shown, are provided for closing and opening the mold sections 78 and 80. When the 13 5 sections are open, the glass sheet 20 is disposed on the lower section 78 so that parts of the rear surface of the glass rest on pads 82 suitably positioned. After proper positioning of the glass sheet 20 on the pads 82 of the lower mold section 78, the upper section 80 is lowered into position so that the peripheral edges of the cooperating sections 78 and 80 can be clamped together with metal contact -metal, outside the molding cavity. The upper section 80 of the mold carries pads 84 which serve, in cooperation with the pads 82, to press elastically against the glass sheet 20 and retain the latter inside the mold cavity. The mold cavity 76 is larger than the formed glass sheet 20, to avoid any glass-metal contact.

Suction heads are shown in Figures 7 and 9 in the upper mold section 80 of the mold 76, to lift the glass with the section 80 when the molding is finished and it is desired to remove the glass sheet 20 from the mold 76. The suction head mainly consists of a suction bowl 86 which communicates with a suction source via a suction pipe 88.

Removable mold segments, generally indicated at 90, are provided at points spaced apart along the circumference of the mold, corresponding to the positions of the legs 28. All the mold segments are identical and are received by sliding in corresponding recesses 92 provided in the lower mold member 78. The outer end of each segment 90, relative to the mold, is fixed to a block 94 operatively connected to the distal end of a reciprocating piston rod 96 of a conventional fluid actuating cylinder 98. The opposite internal end of each segment 90 ends in a contour corresponding to the external profile of the seal 22 and includes an extension 100 which cuts out in the tab 28. In operation , the piston rod 96 is extended, moving the mold segment 90 forward (FIGS. 8 and 10), ready to receive the charge of resin for forming the seal. After polymerization and setting of the seal material, the piston rod 96 and the movable mold segment 90 are removed, as indicated in dotted lines in FIG. 10, removing the extension 100 from the cutout of the tab 28, releasing the tab and the rear window system to allow removal from the lower part of the mold 78 by the intake by suction of the upper mold element 80.

After discharging the transparent panel from the mold member 78, any excess sealant is removed at a station 100, the panel is washed and dried at station 110, and the paint coating 38 is applied to the section of external exposed frame of the joint 22 and is baked at station 120.

The example which follows constitutes the best embodiment currently envisaged by the inventor. It should be understood in the sense of an illustration, not as a limitation.

EXAMPLE

The surfaces of the upper section and of the lower section 80 and 78 of the mold, which surround the molding cavity therebetween after assembly, are treated with a solvent-based release agent which is a mixture of waxes; the particular release agent is commercially available from Park Chemical Company, Detroit, Michigan, E.U.A., under the trademark "PRC-789". A glass sheet 20 is then suitably placed on the lower mold 78, after which the upper mold 80 is fitted on the lower mold 78, and the two are clamped together. A charge composed of one part by weight of a polyol composition and 0.63 part by weight of an isocyanate is then removed into the head of 15 * 2 mixture 74 under a pressure of 175 kg / m and from there in the mold 76 under a pressure of approximately 3.5 * 2 kg / m. The polyol and isocyanate streams are at a temperature of 43 ° C, while the mold 76 is at a temperature of 63 ° C. The polyol and isocyanate streams are intimately mixed in the head 74 before reaching the mold 76. The urethane composition is injected into it approximately one and a half minutes later, the mold is opened, and the panel 10 is removed therefrom. .

The resulting elastomer seal 22 is microcellular, has a specific gravity of 1.07 g / cc, a hardness (Shore A) of 90, a tensile modulus of 105 kg / cm, an elongation at break of 279% and a flexural modulus (at 24 ° C) of approximately 345 kg / cm ^.

The polyol composition used for the implementation of the procedure described in the preceding example is formed from 45 kg of a base polyol, in fact a polyether triol with a molecular weight of 6000 with a "covering" ("capping") of ethylene oxide, sold under the registered trademark "Voranol" 5815 by Dow Chemical Company, Midland, Michigan, USA; 4.5 kg of ethylene glycol, and 1.4 kg of 20% carbon black in a polyol.

The isocyanate used in carrying out the procedure of the above example is a modified 4,4'-diphenylmethane diisocyanate sold under the brand "Rubinate LF 179" by Rubicon Chemicals Inc., Geismar, Louisiana.

The foregoing components are catalyzed by the addition of dibutyltin dilaurate, and a solution of triethylenediamine in dipropylene glycol.

It will be understood that various modifications can be made to the specific details of the invention as it has been described, without departing from the scope and the spirit of the invention as defined in the appended claims. For example, 16, although the preformed transparent panel 10 is a rear window structure for an automobile, it is understood that an assembly according to the invention will work equally well in any glazing application for vehicles such as automobiles, trucks, vans, buses, as well as many other applications including architecture, instruments and boats.

The configurations of the framing part 24 and the molded part 22 tend by themselves to obtain aerodynamic objectives for the automotive industry. Increasingly, an objective of automotive designers is to create aerodynamically cleaner forms of vehicles to increase the efficiency of the vehicle, and thus reduce the power required to reduce consumption. Since the rear window and the windshield of the vehicle are obvious sources of considerable resistance to a regular flow of air, constant attention has been paid to improving the aerodynamic design of the shape of the rear windows and the windshield, and fixing means and decorative framing associated therewith.

It will be understood, by considering the windshield structures of the currently known types, which have been discussed above, that the various fixing and framing means were imperfect from an aerodynamic point of view and created turbulent flows detrimental to the overall efficiency. of the vehicle, and producing annoying air flow noises inside the moving vehicle. The invention provides windshields which can be integrated into a flush mounting system, in which the framing portion corresponding to a portion 24 of the mounting element or seal 22 is substantially flush with the adjacent surfaces, thus very substantially improving the 17 'aerodynamic characteristics and reducing the turbulent flows and the resulting noise.

Although the preferred embodiment of the invention uses a polyurethane composition to achieve the desired results, other compositions of nylons, polyesters and epoxy can be used.

Claims (21)

18 1. Glazing comprising a sheet of transparent material and a seal formed of a synthetic polymer adhering to predetermined parts of the sheet, characterized in that the seal has been polymerized in situ near the predetermined parts of the sheet and has taken by an autogenous mechanism resulting from its polymerization and its taking in a confined state, intimate contact with the parts to which it adheres. 2. Glazing according to claim 1, characterized in that the seal comprises a framing section extending towards the outside of the sheet in a plane essentially parallel to the front, peripheral, marginal, adjacent surface of the sheet. 3. Glazing according to any one of claims 1 or 2, characterized in that the sheet material is glass. 4. Glazing according to any one of claims 1 to 3, characterized in that the sheet material is laminated glass. 5. Glazing according to claim 3, characterized in that the glass sheet is toughened. 6. Glazing according to any one of claims 1 to 5, characterized in that the seal extends completely around the periphery of the sheet and adheres to the surfaces of the adjacent edges thereof. 7. Glazing according to any one of claims 1 to 6, characterized in that the seal is formed of a polyurethane. 8. Glazing according to any one of claims 1 to 7, characterized in that the seal is formed from a microcellular polyurethane elastomer. 9. Glazing according to any one of claims 1 to 8, characterized by a coating absorbing the ultraviolet on the exposed surface of the seal. 19 · 10. Glazing according to any one of claims 1 to 9, characterized in that the seal comprises a hollow of generally U-shaped cross section, opening towards the outside of the rear edge surface of the sheet. 11. Glazing according to claim 10, characterized in that the recess is defined by a pair of rib elements forming between them an area intended to receive an adhesive. 12. A method of producing an assembly formed of a transparent sheet material and of a seal adhering to its periphery, characterized in that it consists in a) positioning a transparent sheet material inside a mold cavity formed by several cooperating mold sections, the mold cavity having, with respect to the transparent sheet, the shape and position of the finished joint, and surrounding the edge surfaces of the sheet immediately adjacent to its periphery, b) injecting into the molding cavity a composition which can polymerize and harden to produce a joint and, when it has hardened in contact with them, adheres to the edge surfaces of the sheet material, c) controlling the pressure at which the composition is - injected into the molding cavity so that it is sufficiently weak so as not to damage the sheet material, d) controlling the temperature of the molding cavity, the injection of the composition and the quantity of the composite tion injected so that the composition polymerizes after its injection and comes, by the autogenous pressure arising from the polymerization, into intimate contact with the mold cavity and with the sheet material, and hardens during this contact, and e) removing the assembly of the mold cavity. 13. Method according to claim 12, characterized in that a bottom coating is applied to the edge surfaces of the sheet material before positioning this material in the mold cavity, this bottom coating being effective for reinforcing the adhesion of the joint to the edge surfaces. 14. Method according to claim 12 or 13, characterized in that the composition forming the joint comprises an isocyanate and a polyol and, during polymerization and setting, forms a microcellular polyurethane elastomer. 15. The method of claim 14, characterized in that the mold sections surrounding the molding cavity are maintained at a temperature in the range of approximately 60-71 ° C. 16. Method according to any one of claims 14 or 15, characterized in that the composition is injected into the molding cavity at a pressure of approximately 3.5 to 7 kg / cm. 17. Method according to any one of claims 12 to 16, characterized in that the sheet material is laminated glass. 18. Method according to any one of claims 12 to 16, characterized in that the sheet material is tempered glass. 19. A method according to any one of claims 12 to 18, characterized by the step of applying an ultraviolet absorbent coating on the exposed surface of the joint, after its removal from the molding cavity. 20. Glazing, in substance as defined in conjunction with the accompanying drawings. 21. Method for producing an assembly formed from a sheet material and a seal adhering to its periphery, in substance as described in the description.