WO2025023817A1 - Method for producing a piece of reinforced laminated glass - Google Patents

Abstract

The present invention relates to a method for producing a piece of reinforced laminated glass (1) comprising: a piece of curved glass (1a), which has a first surface (2), a second surface (3) and an edge (4); at least one polycarbonate sheet (5); and at least one adhesive film (6), wherein the method comprises the following steps: subjecting the at least one polycarbonate sheet (5) to a shaping process such that it adopts the curvature of the curved glass (1a); forming an assembly (10) by placing the at least one adhesive film (6) between one of the surfaces (2, 3) of the curved glass (1a) and the at least one polycarbonate sheet (5) and, where appropriate, between contiguous polycarbonate sheets (5); subjecting the assembly (10) to a prelamination process and to a lamination process such that at least one of the surfaces (2, 3) of the curved glass (1a) is joined to one or more polycarbonate sheets (5), the sheets being joined together.

Description

METHOD FOR PRODUCING REINFORCED LAMINATED GLASS

FIELD OF INVENTION

The invention relates to the field of materials technology, specifically to methods for producing reinforced glass, such as safety glass, impact-resistant glass, bullet-proof glass, particularly applied to the automotive sector.

BACKGROUND OF THE INVENTION

Reinforced glass has been used for a long time to provide protection against different external situations for people who use spaces that require external lighting and in vehicles, such as assault vehicles, personnel transport, cars, aircraft, among others, as well as to provide protection to buildings and other structures, such as houses, bunkers, etc.

External situations may include, but are not limited to, impacts from projectiles such as bullets, shrapnel, impacts from hammers, axes, waves generated by nearby explosions, etc.

Such glasses are commonly laminated and are usually a combination of multiple sheets or films of glass, plastic, resin, and/or other hard or elastic materials. When a projectile impacts a reinforced glass, the glass sheet of the reinforced glass exposed to the impact must resist puncture, while the sheet on the opposite side, for example, an elastic film such as a polymer film, must prevent the fragments thrown back from the exposed sheet from penetrating completely through the reinforced glass.

A conventional reinforced glass capable of fulfilling the above-mentioned action typically includes a laminated glass comprising more than one glass sheet, which are bonded together by layers of polyvinyl butyral. On the inner face of said laminated glass, a polycarbonate sheet is arranged which is bonded to the innermost glass sheet by means of a film of thermoplastic polyurethane-based adhesive. However, despite said reinforced glass being able to fulfill its purpose, difficulties arise when temperature changes occur, and there is different thermal expansion between a glass sheet and, for example, a polycarbonate sheet, which causes deformations, even leading to delamination of the reinforced glass.

Delamination is a defect commonly observed in laminated glass and therefore in reinforced glass, which is defined as the gradual reduction of adhesion between some or all of the laminated glass sheets or films. This means that the intermediate sheet or film between the glass and the reinforcement, the energy-absorbing film or between the glass itself, loses adhesion to join these sheets or films in a homogeneous manner.

Delamination in reinforced glass can be caused by different factors, as mentioned above, one cause is the result of different rates of thermal expansion between the glass sheet and the polycarbonate. Other causes can be, for example, thermal changes, application of external forces such as ballistic projectiles, water penetration between the various sheets of a reinforced glass, etc., which can lead to the reduction of the life cycle of the reinforced glass.

It has also been observed that when it comes to curved reinforced glass, delamination occurs in shorter periods of time.

In addition to the above-mentioned factors that cause the presence of this defect, when it comes to curved reinforced glass, the sheets and films included in said reinforced glass must adopt the same curvature as the curved glass sheet to be used. In these cases, the polycarbonate sheets, which are initially rigid and flat, tend to return to their original flat shape gradually after adopting the curvature of the glass, causing delamination of the reinforced glass.

To address the problem of delamination of reinforced glass, other materials have been incorporated to prevent the appearance of this defect and improve the adhesion between glass and polycarbonate. For example, US patent application US 4,663,228 A describes a laminated glass incorporating an ionomer resin instead of a thermoplastic polyurethane-based adhesive film. The reinforced glass comprises different sheets of glass and polycarbonate, where the polycarbonate is adhered to a glass sheet by a layer of ionomer resin. However, this invention does not address the problems of delamination due to temperature changes and does not consider the early appearance of such a defect in curved glass.

German patent application DE 69429559 discloses armoured glass, in particular for cars, which consists of several glass sheets connected to each other by intermediate films of thermoplastic polymer and a sheet of impact-resistant plastic material which is applied with the aid of a thermoplastic adhesive film to the inner surface of the armoured glass. In order to reduce delamination of an armoured glass, a reflective layer is placed on the outermost glass sheet of the armoured glass, so that the thermal radiation to which the outermost glass sheet is exposed is projected towards the outermost glass sheet. the exterior, protecting the inner layers of the laminated armoured glass. However, this invention does not consider the early appearance of such a defect in curved glass.

Likewise, in the automotive field of application, where reinforced glass is usually used, it is common to replace the vehicle's glass with completely new toughened glass, which requires providing ironwork dies with the shape of the vehicle's original glass, with which the desired shape will be given to the new glass using a bending oven, considerably increasing manufacturing costs and times.

Reinforced glass applied to motor vehicles is usually composed of several sheets of glass that must go through their respective bending process, which considerably increases the weight of the motor vehicle, and at least one sheet of polycarbonate on the innermost side of the reinforced glass, which usually presents delamination when subjected to frequent temperature changes, either due to exposure to the sun or the use of air conditioning.

Due to the composition of reinforced glass mentioned above, it is common that its installation in the automotive vehicle requires structural changes, including modifications to the doors, in particular, to the space available in the vehicle frame for the insertion of the glass and to the vehicle lifting systems, when it comes to side window glass.

As an additional safety measure, a metalized polyester film is often applied to reinforced glass to polarize the windows of automotive vehicles and thus provide better visibility to the user when exposed to sunlight. This polyester film is applied to the polycarbonate sheet, allowing interaction between these two plastic materials, which, due to their exposure to temperature changes, generate gases between them, causing air bubbles to form and deteriorating visibility for the vehicle user, requiring the polyester film to be replaced frequently.

In view of the state of the art, there is a need to provide a reinforced glass that meets the requirements of impact resistance, that has a longer life cycle with respect to the presence of delamination defects, considering curved reinforced glass, that can be applied to a motor vehicle, that provides good visibility to the user and that can additionally be produced and installed more economically compared to already known reinforced glass. This need is covered by the method described and claimed in the present application. BRIEF DESCRIPTION OF THE INVENTION

In view of the disadvantages of the state of the art, the objective of the present invention is to provide a reinforced laminated glass, so that it can be used as safety glass, armored glass, impact-resistant or bullet-resistant, in particular that it can be applied to a motor vehicle, and that it offers a longer life cycle with respect to the appearance of delamination defects, considering that curved glass is used, good visibility and whose production involves less time and costs compared to the methods of manufacturing reinforced glass that are known in the state of the art.

In order to meet the objectives set forth in the present invention, a method is provided for producing reinforced laminated glass comprising: a curved glass having a first surface, a second surface and a contour, at least one polycarbonate sheet; and at least one adhesive film; wherein the method in its most general expression comprises the following steps: subjecting the at least one polycarbonate sheet to a shaping process so that it adopts the curvature of the curved glass; forming an assembly by placing the at least one adhesive film between at least one of the surfaces of the curved glass and the at least one polycarbonate sheet and, where appropriate, between adjacent polycarbonate sheets; subjecting the assembly to a pre-laminating process and a laminating process, such that one of the surfaces of the curved glass is bonded to one or more polycarbonate sheets, which in turn are bonded together.

In one embodiment, the method for producing reinforced laminated glass contemplates that the curved glass is a glass of an automotive vehicle.

The present invention also relates to a reinforced laminated glass obtained by the method as described above.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 illustrates an exploded top view of the components of a reinforced laminated glass (1) in accordance with one embodiment of the present invention.

Figure 2 illustrates an exploded top view of the components of a reinforced laminated glass (1) in accordance with one embodiment of the present invention.

Figure 3 illustrates an exploded perspective view of the components of a reinforced laminated glass (1) for a side window of an automotive vehicle in accordance with one embodiment of the present invention. Figure 4 illustrates an exploded perspective view of the components of a reinforced laminated glass (1) for a side window of an automotive vehicle in accordance with one embodiment of the present invention.

Figure 5 illustrates a side view of the reinforced laminated glass (1) of Figure 4.

Figure 6 illustrates a view from the inner side of the reinforced laminated glass (1) of Figure 4.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is described herein using exemplary embodiments and with reference to the accompanying figures, it is understood that other embodiments may be utilized, and that changes may be made using equivalent or similar elements or steps without departing from the spirit and scope of the present invention.

Referring to Figure 1, the invention relates generally to a method for producing a reinforced laminated glass (1) comprising a curved glass (1a), which has a first surface (2), a second surface (3) and a contour (4); at least one polycarbonate sheet (5); and at least one adhesive film (6), wherein the method comprises the following steps: subjecting the at least one polycarbonate sheet (5) to a forming process so that it adopts the curvature of the curved glass (1a); forming an assembly (10) by placing the at least one adhesive film (6) between one of the surfaces (2,3) of the curved glass (1a) and the at least one polycarbonate sheet (5) and, where appropriate, between adjacent polycarbonate sheets (5); subjecting the assembly (10) to a pre-laminating process and a laminating process such that at least one of the surfaces (2,3) of the curved glass (1 a) is joined to one or more polycarbonate sheets (5), which in turn remain joined together.

In the context of the present invention, there is no limitation to the type of glass that can be used in the claimed method. By way of example and not limitation, the curved glass (1 a) can be selected from any of tempered, float or toughened glass.

In the context of the present invention, the material of the at least one adhesive film (6) is not limited and can be selected from any adhesive material known in the field of the invention. Also, in case of using more than one adhesive film (6), they can be selected from the same or different adhesive materials.

Preferably, the at least one adhesive film (6) is a polyurethane (PU)-based adhesive film, and more preferably an adhesive film based on a polyether-based thermoplastic polyurethane, and more preferably an adhesive film based on a polyether-based thermoplastic polyurethane. Preferably the adhesive film is a film based on a polyether-based thermoplastic polyurethane commercially known as “KRYSTALFLEX® PE399”.

In the context of the present invention, the type and grade of the at least one polycarbonate sheet (5) are not particularly limited and may be selected from any type and grade of polycarbonate known in the field of the invention. Also, in case of using more than one polycarbonate sheet (5), they may be selected from the same or different types and grades.

Preferably, the at least one polycarbonate sheet (5) is of a type and grade that loses rigidity at a temperature of between 100°C and 300°C, depending on the thickness and characteristics thereof, preferably at approximately 175°C, and more preferably it is a high-impact UV-stabilized polycarbonate sheet for glazing commercially known as “LEXAN™ 9034”.

In the state of the art methods, the at least one polycarbonate sheet (5) with which the curved glass (1 a) will be reinforced must adopt the curvature of said glass (1 a) during a laminating process. Due to the nature of polycarbonate, once deformed, this material seeks to gradually recover its original flat shape. This effect can be accelerated by the temperature changes to which the reinforced laminated glass (1 ) is subjected during its use, thus promoting the appearance of delamination defects in short periods of time.

When delamination defects occur in reinforced laminated glass, its properties, such as impact resistance or good visibility, are deteriorated, requiring the complete replacement of said glass.

In the present invention it has been found that by subjecting at least one polycarbonate sheet (5) to a forming process prior to the lamination process, the time in which the polycarbonate manages to return to its original flat shape is prolonged, providing a longer life cycle of the reinforced laminated glass (1) with respect to the appearance of delamination defects.

The shaping process of the at least one polycarbonate sheet (5) is carried out by heating in a molding oven (not shown). Since the polycarbonate sheet (5) will be molded to the shape and curvature of the curved glass (1 a), said curved glass (1 a) is used as a mold, so that the polycarbonate sheet (5) is placed on at least one of the surfaces (2, 3) of the curved glass (1 a) and is introduced into the molding oven. In one embodiment, the curved glass (1 a) is reinforced only in one from its sides, so that the polycarbonate sheet (5) is placed on one of the surfaces (2, 3). The temperature of the molding oven is adjusted between 100 ° C and 300 ° C, and more preferably at 175 ° C, so that when this temperature is reached the polycarbonate sheet (5) begins to deform until it adopts the desired shape and curvature. The residence time of the polycarbonate sheet (5) inside the molding oven is not limited to a specific value, since it will remain there until it completely adopts the shape of the curved glass (1 a), carrying out visual inspections at defined time intervals.

Once the polycarbonate sheet (5) has adopted the desired curvature, the polycarbonate sheet (5) and the curved glass (1 a) are removed from the molding oven and the curved glass (1 a) is cleaned in order to remove any residue.

When the reinforced laminated glass (1) comprises more than one polycarbonate sheet (5), the forming process of said polycarbonate sheets (5) can be carried out jointly, preferably, the forming process is carried out individually.

Subsequently, an assembly (10) is formed comprising at least one adhesive film (6) arranged between one of the surfaces (2, 3) of the curved glass (1 a) and the at least one polycarbonate sheet (5), and in the event that two or more polycarbonate sheets (5) are comprised, at least one adhesive film (6) is arranged between said adjacent polycarbonate sheets (5), ensuring that there is no movement in the assembly (10) and placing adhesive tapes or fixing clips.

In this way, a polycarbonate sheet (5) will be joined to at least one of the surfaces (2, 3) of the curved glass (1 a) by means of one or more adhesive films (6) arranged intermediately between them and in case of having more than one polycarbonate sheet (5), these will be joined together by means of one or more adhesive films (6) arranged intermediately between them.

The dimensions of the at least one adhesive film (6) and the at least one polycarbonate sheet (5) may be the same or smaller than the dimensions of the curved glass (1 a), depending on the percentage of surface to be protected.

To adjust the dimensions and shape of the at least one polycarbonate sheet (5) and the at least one adhesive film (6), any suitable cutting method is used, for example, laser cutting, CNC router (computer numerical control), etc.

Once the assembly (10) is formed, it is subjected to a pre-laminating process that includes: introducing the assembly (10) into a vacuum bag and performing a vacuum operation; placing the vacuum bag with the assembly (10) into an autoclave and starting heating until reaching a temperature between 80°C and 125°C and a pressure of at least 3 Kg/cm ² , preferably a pressure of at least 7 Kg/cm ² , with a residence time of 10 to 15 minutes after reaching said temperature and pressure values; allowing the autoclave to cool for 25 to 35 minutes, evacuating all the air from the autoclave and removing the pre-laminated assembly (10) from the vacuum bag, verifying that the process has been carried out properly.

Subsequently, the pre-laminated assembly (10) is subjected to a laminating process comprising: placing the pre-laminated assembly (10) obtained in the previous step inside the autoclave equipped with a cooling water pump and pressurizing until reaching a pressure of at least 3 Kg/cm ² , preferably a pressure of at least 7 Kg/cm ² , starting the heating to reach a temperature between 100°C to 125°C for a residence time of 110 to 130 minutes; once the desired temperature and pressure values are reached and the process times are completed, the pressure of the autoclave is released causing the temperature to drop; after reaching an autoclave temperature between 89°C and 93°C; accelerate the cooling process by turning on the water pump; Once the temperature decreases to between 76°C and 78°C, remove the assembly (10) from the autoclave.

Finally, a thorough cleaning is carried out on the reinforced laminated glass (1) obtained.

Referring again to Figure 1, an exploded top view of the components of a reinforced laminated glass (1) made according to one embodiment of the method described above is illustrated. Said reinforced laminated glass (1) comprises an assembly (10) formed by: a curved glass (1a) having a first surface (2), a second surface (3) and a contour (4), an adhesive film (6) disposed on the first surface (2) of the curved glass (1a); and a polycarbonate sheet (5) disposed on said adhesive film (6). Figure 2 illustrates an exploded top view of the components of a reinforced laminated glass (1) made according to an embodiment of the method described above, wherein said reinforced laminated glass (1) comprises an assembly (10) formed by: a curved glass (1a) having a first surface (2), a second surface (3) and a contour (4); a first adhesive film (6) disposed on the first surface (2) of the curved glass (1a); a first polycarbonate sheet (5) disposed on said first adhesive film (6); a second adhesive film (6) disposed on the first polycarbonate film (5); and a second polycarbonate sheet (5) disposed on said second adhesive film (6).

The number of polycarbonate sheets (5) used to produce the reinforced laminated glass (1) according to the present invention is not particularly limited, and is defined according to the level of protection desired, as well as the dimensions of the housings in which it is to be placed. One of the advantages of the present invention is that it is possible to avoid making modifications to said housings due to the difference between normal glass and reinforced glass, which is commonly necessary, for example, in the case of armoured glass.

In one embodiment of the present invention, the method for producing a reinforced laminated glass (1) contemplates that the curved glass (1a) used is a glass of an automotive vehicle.

Said glass belonging to a motor vehicle is a curved glass (1 a) having a first surface (2), a second surface (3) and a contour (4). In this case the first surface (2) of the curved glass (1 a) corresponds to the inner surface and the second surface (3) of the curved glass (1 a) corresponds to the outer surface in reference to the vehicle cabin. That is, the term “interior” refers to the side of the curved glass (1 a) which, when installed, faces the inside of the vehicle cabin, while the term “exterior” refers to the side of the curved glass (1 a) which, when installed, faces the outside of the vehicle cabin.

To use the glass belonging to a motor vehicle (1 a) it is necessary to take the measurements of the dimensions of the surfaces (2, 3) of the curved glass (1 a) in its entirety, since said curved glasses (1 a) have measurements and/or dimensions for be properly fitted to the corresponding vehicle frame. It should also be noted that said frame has a space or slot, into which the glass is inserted, so that the reinforced laminated glass (1) must have an adequate thickness to allow it to be inserted into the corresponding frame space. Otherwise, modifications to the vehicle structure are necessary.

Also, measurements must be taken of the space surrounded by the frame, i.e. the contour of the vehicle window. These dimensions are smaller than those of the surfaces (2, 3) of the complete curved glass (1 a).

In the state of the art, the vehicle glass to be reinforced is replaced with a completely new glass. The reason for this is that vehicle glass is usually tempered glass, which breaks into small fragments after being hit. This effect is undesirable in safety glass, because small fragments of glass can enter the interior space protected by the glass, which is dangerous for the occupant of that space. Therefore, tempered or laminated glass is usually replaced with hardened glass.

In the present invention, preferably, curved glass (1 a) belonging to the motor vehicle is used, which is tempered glass. To prevent said curved glass (1 a) from fragmenting into small pieces that can enter the interior space of the vehicle after receiving an impact, the glass is reinforced on its entire first surface (2) with a polycarbonate sheet (5) that will cushion the impact and, in the event of breakage, the small pieces of glass cannot enter the interior of the vehicle.

In relation to the above, in this embodiment the assembly (10) composed of the curved glass (1 a) of the vehicle, at least one polycarbonate sheet (5) and at least one adhesive film (6) are joined on the first surface (2) of the curved glass (1 a); which corresponds to the surface facing the interior of the vehicle cabin and the dimensions of the assembly (10) coincide with the dimensions of said first surface (2).

Likewise, said assembly (10) is subjected to the pre-laminating and laminating processes described above.

The reinforced laminated glass (1 ) obtained in this modality has a thickness that allows it to fit into the space available in the frame of the vehicle for the insertion of the automotive vehicle glass without modifying said space. Therefore, the number of polycarbonate sheets (5) used to reinforce the curved glass (1 a) and their respective thicknesses are limited by the dimension of said space. With reference to Figures 4 to 6, in a further embodiment of the present invention, the method for producing a reinforced laminated glass (1) using a curved glass (1a) of an automotive vehicle comprises providing at least one additional polycarbonate sheet (5').

Since the previously formed assembly (10) provides the reinforced laminated glass (1) with the thickness that allows it to fit into the space available in the vehicle frame for the insertion of the automotive vehicle glass, the at least one additional polycarbonate sheet (5') is not inserted into said space of the vehicle frame, and as a consequence, the dimensions of its surfaces are smaller with respect to the surfaces (2, 3) of the curved glass (1 a), see Figure (6).

Preferably, the dimensions of the at least one additional polycarbonate sheet (5') coincide with the dimensions of the contour of the window of the motor vehicle, so that additional protection is provided to the entire space defined by the contour of said window.

The type and grade of said at least one additional polycarbonate sheet (5') is not particularly limited, and may be selected in the same manner as the polycarbonate sheet (5) as described above.

Said at least one additional polycarbonate sheet (5') is also subjected to the forming process described above and is aligned concentrically on the last polycarbonate sheet (5) of the assembly (10), that is, the innermost polycarbonate sheet with respect to the vehicle cabin, placing at least one adhesive film (6) intermediately between them and, in case two or more additional polycarbonate sheets (5') are comprised, at least one adhesive film (6) is arranged between the adjacent additional polycarbonate sheets (5'), such that a tab (7) is formed on the periphery of the reinforced laminated glass (1) obtained, wherein said tab (7) has a thickness and height that allows said reinforced laminated glass (1) to be fitted in the space available in the frame of the vehicle for the insertion of the automotive vehicle glass without modifying said space.

Once the at least one additional polycarbonate sheet (5') is aligned on the assembly (10), they are subjected to the pre-laminating and laminating processes described above, placing adhesive tapes or fixing clips to ensure that there is no movement between the sheets and films.

Likewise, preferably, the pre-laminating and laminating processes can be carried out individually first to the assembly (10) and, in the case of comprising more than one additional polycarbonate sheet (5'), to said polycarbonate sheets additional (5') joined together by at least one adhesive film (6), and subsequently carry out the alignment and subject the aligned product to an additional pre-laminating and laminating process comprising: introducing the aligned product into a vacuum bag and performing a vacuum operation; placing the vacuum bag with the aligned product inside an autoclave, and starting the heating until reaching a temperature between 80°C and 125°C and a pressure of at least 3 Kg/cm ² , preferably a pressure of at least 7 Kg/cm ² , with a residence time of 10 to 15 minutes after reaching said temperature and pressure values; allowing the autoclave to cool for 25 to 30 minutes; evacuating all the air from the autoclave and removing the aligned product from the vacuum bag, verifying that the process has been carried out properly.

Subsequently, the pre-laminated aligned product is subjected to a laminating process comprising: placing the pre-laminated aligned product obtained in the previous step inside the autoclave equipped with a cooling water pump and pressurizing until reaching a pressure of at least 3 Kg/cm ² , preferably a pressure of at least 7 Kg/cm ² , starting the heating to reach a temperature between 100 ° C and 125 ° C for a residence time of 110 to 130 minutes; once the desired temperature and pressure values are reached and the process times are completed, the pressure of the autoclave is released causing the temperature to drop; after reaching an autoclave temperature between 89 ° C and 93 ° C; accelerate the cooling process by turning on the water pump; Once the temperature drops to between 76°C and 78°C, remove the reinforced laminated glass (1) obtained from the autoclave and allow it to cool in the air.

Additionally, spray paint can be applied to the outline of the reinforced laminated glass (1), preferably a matte black paint is applied. At this point, carbon fiber or some other element can be applied to improve the appearance of the glass.

A high-performance polyurethane-based elastic sealant is applied to the contour of the reinforced laminated glass (1) and left to dry for approximately 10 to 12 hours. Preferably and without limitation, an elastic sealant commercially known as SICAFLEX®-1A is used. Preferably and without limitation, use can be made of glass fusion paints and/or enamels and a vitrification oven to reduce drying times.

Finally, the reinforced laminated glass (1) obtained is installed in the motor vehicle, where the thickness and height of the tab (7) formed by the alignment of the assembly (10) and the at least one additional polycarbonate sheet (5') is such that it allows it to fit into the space available in the frame of the vehicle corresponding to the insertion of said glass, without the need to make any modification to the structure of the vehicle.

The thickness of the tab (7) of the reinforced laminated glass (1) must be adequate to allow it to fit into the space available in the vehicle frame for the insertion of the automotive vehicle glass without modifying said space, so that the number of polycarbonate sheets (5) used to form the assembly (10) and their respective thicknesses are limited by the dimension of said space.

In an advantageous embodiment, at least one sheet of the at least one polycarbonate sheet (5) and the at least one additional polycarbonate sheet (5') comprises color.

Typically, a polarizing film consisting of polyester is applied to automotive vehicle windows to provide the vehicle user with better visibility when exposed to sunlight and greater privacy.

However, in the case of reinforced glass that includes at least one sheet of polycarbonate, the interaction between the polycarbonate and the polyester generates gases, which are trapped between the sheets, producing bubbles and limiting the user's visibility. This effect means that the polarization of the glass has to be changed constantly.

Therefore, when using tinted polycarbonate in the manufacture of reinforced laminated glass, the same polarizing effect can be produced, without the need to apply a polyester film. In this way, the negative effects caused by the interaction between polycarbonate and polyester will not occur.

Likewise, different levels or shades of polarization can be achieved by providing one or more polycarbonate sheets (5, 5') with different color intensities to reinforce the glass.

Figure 3 illustrates an exploded perspective view of the components of a reinforced laminated glass (1) for a side window of a motor vehicle made according to an embodiment of the method described above comprising an assembly (10) formed by: a curved glass (1 a) of a side window of a motor vehicle having a first surface (2), a second surface (3) and a contour (4); an adhesive film (6) disposed on the first surface (2) of the curved glass (1 a); and a polycarbonate sheet (5) disposed on said adhesive film (6).

Figure 4 illustrates an exploded perspective view of the components of a reinforced laminated glass (1) for a side window of a motor vehicle made according to an embodiment of the method described above comprising an assembly (10) formed by: a curved glass (1a) of a side window of a motor vehicle having a first surface (2), a second surface (3) and a contour (4); an adhesive film (6) disposed on the first surface (2) of the curved glass (1a); a polycarbonate sheet (5) disposed on said adhesive film (6); and a set of sheets disposed on the last polycarbonate sheet (5) of the assembly (10), the set formed by: two first and second adhesive films (6); a first additional polycarbonate sheet (5') disposed on said two first and second adhesive films (6); a third adhesive film (6) disposed on said first additional polycarbonate sheet (5'); a second additional polycarbonate sheet (5') disposed on said third adhesive film (6); a fourth adhesive film (6) disposed on said second additional polycarbonate sheet (5'); and a third additional polycarbonate sheet (5') disposed on said fourth adhesive film (6).

Figure 5 illustrates a side view of the reinforced laminated glass (1) for a side window of an automotive vehicle in Figure 4. Figure 5 shows the thickness and height of the flange (7) formed on the periphery of the reinforced laminated glass (1).

Figure 6 illustrates a view from the inner side of the reinforced laminated glass (1) for a side window of an automotive vehicle in Figure 4, where the height of the tab (7) formed on the periphery of the reinforced laminated glass (1) can be seen.

The number of additional polycarbonate sheets (5') is not particularly limited, and is defined based on the level of protection desired in the laminated glass. reinforced (1) of the motor vehicle.

The method described above is advantageous over the known state of the art because it allows obtaining a reinforced laminated glass (1) with a longer life cycle with respect to the presence of delamination defects, because the sheet or sheets of polycarbonate (5) and additional polycarbonate (5') used to reinforce the curved glass (1a) are subjected to a prior shaping treatment before being laminated with the curved glass (1a), where they are shaped to the desired curvature to prevent them from recovering their original flat shape during use in short periods of time.

The fact that the appearance of delamination defects in the reinforced laminated curved glass of the invention is delayed guarantees that the impact resistance and good visibility properties will be maintained, since once the polycarbonate begins to detach from the glass, air bubbles are generated between both sheets, deteriorating their properties and affecting visibility.

Furthermore, reinforcing the curved glass (1 a) only with polycarbonate sheets (5) and not with additional glass sheets offers a lighter glass that provides the same protection with a more economical manufacturing process. It is important to mention that in the automotive field, reducing the weight of any component has a significant impact on the performance of the vehicle.

In this sense, when using curved glass (1 a) belonging to the vehicle, the processes associated with the purchase or production of new glass are avoided, which must be deformed according to the dimensions of the vehicle to be reinforced, significantly reducing manufacturing times and costs.

Additionally, the formation of a tab (7), which is also protected by a polycarbonate sheet (5), allows the curved glass (1 a) of the vehicle, once reinforced, to be installed in the corresponding vehicle frame without the need to modify the structure of said frame or change the vehicle's lifting systems when it comes to side window glass. Usually, referring to bulletproof armoured glass, the glass resulting from processes known in the state of the art is very thick and heavy, since it comprises several sheets of glass, forcing cuts to be made in the vehicle door and completely replacing the lifting systems.

Finally, the use of colored polycarbonate in reinforced laminated glass produces a polarizing effect without the need to apply additional plastic films and avoiding the problems caused by them. Thus, with the present invention, a reinforced laminated glass (1) can be provided, which can be used in an automotive vehicle, which can be configured for anti-impact or bulletproof glass with a longer life cycle with respect to the appearance of delamination defects, good visibility and whose production involves less time and costs compared to the methods of manufacturing reinforced glass that are known in the state of the art.

Example

In a non-limiting example of the present invention, a curved glass (1 a) of a side window of an automotive vehicle was reinforced according to a method in accordance with the present invention, wherein before removing the curved glass (1 a) from the vehicle, measurements were taken with respect to the contour of the frame window supporting said glass.

Once the curved glass (1a) was removed from the vehicle, it was placed on a stand in order to remove any stickers, safety film or tinting. It was then cleaned with a residue-free towel and a second cleaning was performed with ethyl alcohol to ensure its transparency.

A first film of polyurethane-based adhesive (6) commercially called “KRYSTALFLEX® PE399” with a thickness of 0.3 mm was cut in such a way that it covered the entire first surface (2) of the curved glass (1 a).

A first polycarbonate sheet (5) commercially known as “LEXAN™ 9034” with a thickness of 0.75 mm was provided, after performing a visual inspection to verify that the sheet had no holes or scratches. Once the visual inspection was completed, the polycarbonate sheet (5) was cut so that it covered the entire surface of the curved glass (1 a).

The polycarbonate sheet (5) was subjected to a forming process by placing it on the first surface (2) of the curved glass (1 a) and was placed in a molding oven, whose temperature was set at 175°C, for the time necessary for the polycarbonate sheet (5) to completely adopt the shape of the curved glass (1 a).

Once the polycarbonate sheet (5) had adopted the desired curvature, the polycarbonate sheet (5) and the curved glass (1 a) were removed from the molding oven and the curved glass (1 a) was cleaned with alcohol in order to remove any residue.

Four films of polyurethane-based adhesive (6) commercially known as “KRYSTALFLEX® PE399” with a thickness of 0.3 mm were cut in such a way that they had the measurements of the contour of the frame window that supports the curved glass (1 a).

Two additional polycarbonate sheets (5') of a product were provided commercially known as “LEXAN™ 9034” 1.5 mm thick, after performing a visual inspection to verify that the sheet had no holes or scratches. Once the visual inspection was completed, the additional polycarbonate sheets (5') were cut so that they had the measurements of the contour of the frame window that supports the curved glass (1 a).

An additional polycarbonate sheet (5’) with color of the material commercially known as “LEXAN™ 9034” 3 mm thick was provided, after previously performing a visual inspection to verify that the sheet had no holes or scratches. Once the visual inspection was passed, the additional polycarbonate sheet (5’) with color was cut so that it had the measurements of the outline of the frame window that supports the curved glass (1 a).

Additional polycarbonate sheets (5’) were subjected to a forming process, as described above, individually.

An assembly (10) was then formed by placing the polyurethane-based adhesive film (6) having the same dimensions as the curved glass (1a) on the first surface (2) of said glass and the polycarbonate sheet (5) on said polyurethane-based adhesive film (6a) and adhesive tapes were placed to ensure that there was no movement between the components of the assembly (10).

An assembly was formed with the additional polycarbonate sheets (5’) comprising a first additional polycarbonate sheet (5’) 1.5 mm thick, a first polyurethane-based adhesive film (6), a second additional polycarbonate sheet (5’) 1.5 mm thick, a second polyurethane-based adhesive film (6) and the additional colored polycarbonate sheet (5’) 3 mm thick, in that order, placing adhesive tapes to ensure that there is no movement between the components of the assembly.

The assembly (10) and the set of additional polycarbonate sheets (5') were individually introduced into a vacuum bag and a vacuum operation was performed. Then, each vacuum bag was introduced into an autoclave for pre-laminating. The autoclave is equipped with a cooling water pump. The autoclave was started to heat up until a temperature of 94°C and a pressure of 6 Kg/cm ² were reached; once these temperature and pressure values were reached, they were kept in the autoclave for 12 min. Then the autoclave was allowed to cool for 30 minutes, all the air was evacuated from the autoclave and the assembly (10) and the set were removed from its respective vacuum bag, verifying that the process had been carried out properly.

Subsequently, the assembly (10) and the set were reintroduced into the autoclave and pressurized to reach a pressure of 6 Kg/cm ² , while a heating was started to reach a temperature of 120 ° C, the pressure of the autoclave was released when reaching these temperature and pressure, causing the temperature to drop. The residence time was 120 minutes. After reaching an autoclave temperature of 90 ° C, the water pump was turned on to accelerate the cooling process. When the temperature decreased to 77 ° C, the assembly (10) and the laminated set were removed.

A thorough cleaning was carried out and the set of additional polycarbonate sheets (5') was aligned concentrically on the polycarbonate sheet (5) of the assembly (10), placing the two remaining polyurethane-based adhesive films (6) between said set of additional polycarbonate sheets (5') and the assembly (10), placing adhesive tapes to ensure that there is no movement.

The aligned product was put into a vacuum bag and vacuum operation was performed. Then, the vacuum bag with the aligned product inside was put into an autoclave for preliminary. The autoclave is equipped with a cooling water pump. The autoclave was started to heat up until a temperature of 94°C and a pressure of 6 Kg/cm ² were reached. Once these temperature and pressure values were reached, the autoclave was kept for 12 minutes.

The autoclave was then allowed to cool for 30 minutes, all the air was evacuated from the autoclave and the aligned product was removed from the vacuum bag, verifying that the process had been carried out correctly.

The pre-laminated aligned product was then reintroduced into the autoclave for lamination and pressurized to a pressure of 6 Kg/cm ² , while heating was initiated to reach a temperature of 120°C. The autoclave pressure was released upon reaching these temperatures and pressures, causing the temperature to drop. The residence time was 120 minutes. After reaching an autoclave temperature of 90°C, the water pump was turned on to accelerate the cooling process. When the temperature dropped to 77°C, the reinforced laminated glass (1 ) was removed from the autoclave and allowed to cool in the air.

A thorough cleaning was carried out and matte black spray paint was applied on the outline of the reinforced laminated glass (1) and subsequently an elastic sealant commercially known as SICAFLEX®-1 A and left to dry for 12 hours.

Finally, the reinforced laminated glass (1) obtained was installed in the automotive vehicle, where the thickness and height of the tab (7), formed by the alignment of the assembly (10) and the set of additional polycarbonate sheets (5'), were suitable to fit into the space available in the frame of the corresponding vehicle for the insertion of said glass.

The method for reinforcing a reinforced laminated glass (1) for a motor vehicle described in this section corresponds to a specific modality where particular thickness values and quantity of films were used. However, the technical advantages of the present invention are achieved even if both the number of films and their thicknesses are increased or decreased, depending on the desired impact resistance.

REFERENCE LIST

1 Reinforced laminated glass

1 to Curved glass

2 First surface of curved glass

3 Second surface of curved glass

4 Curved glass outline

5 Polycarbonate sheet

5’ Additional polycarbonate sheet

6 Adhesive film

7 Tab

10 Assembly

Claims

1. A method for producing a reinforced laminated glass (1) comprising a curved glass (1a), which has a first surface (2), a second surface (3) and a contour (4); at least one polycarbonate sheet (5); and at least one adhesive film (6); said method characterized in that it comprises the following steps: subjecting the at least one polycarbonate sheet (5) to a forming process so that it adopts the curvature of the curved glass (1a); forming an assembly (10) by placing the at least one adhesive film (6) between at least one of the surfaces (2,3) of the curved glass (1a) and the at least one polycarbonate sheet (5) and, where appropriate, between the adjacent polycarbonate sheets (5); subjecting the assembly (10) to a pre-laminating process and a laminating process so that one of the surfaces (2,3) of the curved glass (1 a) is joined to one or more polycarbonate sheets (5), which in turn remain joined together. 2. The method according to claim 1, further characterized in that the curved glass (1a) is selected from the group consisting of float glass, tempered glass or toughened glass. 3. The method according to any of the preceding claims, further characterized in that at least one of the adhesive films (6) is a polyurethane-based adhesive film. 4. The method according to any of the preceding claims, further characterized in that the forming process of the at least one polycarbonate sheet (5) is carried out by subjecting the curved glass (1 a) together with the at least one polycarbonate sheet (5) arranged on at least one of the surfaces (2,3) of the curved glass (1 a) to heating at a temperature between 100°C and 300°C in a molding oven. 5. The method according to any of the preceding claims, further characterized in that the curved glass (1 a) is a glass of an automotive vehicle, such that the assembly (10) is formed on the first surface (2) of the curved glass (1 a); wherein said first surface (2) corresponds to the surface facing the interior of the vehicle and the dimensions of the assembly (10) coincide with the dimensions of said first surface (2), and wherein the reinforced laminated glass (1 ) obtained has a thickness that allows it to fit into the space available in the frame of the vehicle for the insertion of the automotive vehicle glass without modifying said space. 6. The method according to claim 5, further characterized in that the reinforced laminated glass (1) comprises at least one additional polycarbonate sheet (5') whose dimensions are smaller with respect to the surfaces (2, 3) of the curved glass (1a), such that the assembly forming step (10) additionally comprises: aligning said at least one additional polycarbonate sheet (5') concentrically on the last polycarbonate sheet (5) of the assembly (10), placing at least one adhesive film (6) between them and, where appropriate, between the adjacent additional polycarbonate sheets (5'), such that a flange (7) is formed on the periphery of the reinforced laminated glass (1) obtained, wherein said flange (7) has a thickness and height that allows said reinforced laminated glass (1) to be fitted in the space available in the vehicle frame for the insertion of the automotive vehicle glass without modifying said space. 7. The method according to claims 1 to 6, further characterized in that at least one of the polycarbonate sheets (5) or the additional polycarbonate sheets (5') is colored.