WO2023170609A1

WO2023170609A1 - Armored glass with improved aesthetics and daylight opening

Info

Publication number: WO2023170609A1
Application number: PCT/IB2023/052218
Authority: WO
Inventors: Bianca GUEDES; Jairton POZZEBON; Diornes DUARTE
Original assignee: AGP Worldwide Operations GmbH
Current assignee: AGP Worldwide Operations GmbH
Priority date: 2022-03-08
Filing date: 2023-03-08
Publication date: 2023-09-14
Anticipated expiration: 2024-09-08
Also published as: MX2024010939A

Abstract

The glazing of the disclosure utilizes a thin, chemically tempered, outer glass, strike face layer bonded to a metal reinforcing frame having a combined thickness and obscuration similar to the original OEM glazing being replaced. This reduces the modifications needed to install and gives the vehicle an OEM appearance.

Description

ARMORED GLASS WITH IMPROVED AESTHETICS AND DAYLIGHT OPENING

FIELD OF THE DISCLOSURE

The glazing of the disclosure relates to the field of transportation ballistic resistance glazing.

BACKGROUND OF THE DISCLOSURE

Ballistic resistant glazing, BRG, provides resistance to penetration by projectiles (bullets). BRG laminates work by combining various types of glass and plastics, bonded together by plastic interlayers in a laminate, to absorb and dissipate the energy of the projectile, preventing penetration, and protecting the occupants of the vehicle from the projectile and any spalling of the glass. In a BRG laminate, the glass layers may comprise various glass compositions such as borosilicate and aluminosilicate, in addition to soda-lime, as well as glass that has been strengthened. Rigid plastic, non-bonding layers, comprising but not limited to polyurethane, acrylic and polycarbonate are also used.

The market for BRG glazing for non-military civilian vehicles has been growing due to a number of trends.

One trend has resulted from the improvement in vehicle ignition systems and locks. In recent years, automotive vehicle ignition systems have been improved to the point where it has become virtually impossible to steal a car without having the keys or a tow truck. Similarly, the doors and locks have been improved making it extremely difficult to get into a car without the keys. While these improvements have decreased the incidence of vehicle related theft, they have led to an increase in more serious crimes known as “smash and grab” and “carjacking” as thieves have adapted to the new technology.

In a smash and grab, the thief breaks a window and grabs a purse, computer, GPS or other valuable. In a car-jacking, the driver is forced to hand overthe vehicle to the thief. Both types of crimes often occur while a vehicle is occupied and stopped in traffic.

Also, in many situations, the criminals are armed. In many parts of the world, criminals have easy access to firearms and are not hesitant to use them. Unfortunately, standard automotive glazing present virtually no resistance to even the smallest and least powerful firearm.

Abductions for ransom are also the rise. With high security in homes and offices, the automobile is often where the crime takes place. The typical automobile is especially vulnerable to these types of crimes due to the type of glass that is used in most of them. A closed window does not deter a determined thief due to the ease with which most car windows can be broken.

The glass used in the doors, rear window and side windows of most vehicles is made from tempered glass. Tempered glass is much stronger than ordinary glass. Heat strengthened, full temper, soda lime, float glass, with a compressive strength in the range of at least 70 MPa, can be used in all vehicle positions other than the windshield. Heat strengthened (tempered) glass has a layer of high compression on the outside surfaces of the glass, balanced by tension on the inside of the glass which is produced by the rapid cooling of the hot softened glass. When tempered glass breaks, the tension and compression are no longer in balance and the entire glass part breaks into small beads with dull edges. While tempered glass is very strong and can withstand high loads such as door slams, it can be easily broken by striking with a hard pointed object. A small, readily available, and inexpensive spring-loaded center punch can easily shatter a tempered glazing in a fraction of a second.

Another problem that tempered glass presents is its performance in an accident. When tempered glass fails, the entire window opening is left unprotected. In the event of a car wreck, and especially in a rollover accident, the glass disintegrates leaving the window opening with nothing to prevent ejection of the occupant. Ejection of the occupant and the extension of portions of the body through window openings is a major cause of traffic fatalities and injuries.

Not all of the automotive glazing is made from tempered glass. Windshields are made of laminated annealed glass. Annealed glass is glass that has been slowly cooled from the bending temperature down through the glass transition range. This is done to relieve any stress in the glass. Annealed glass breaks into large shards with sharp edges. In a laminate, two sheets of annealed glass are bonded together using a soft plastic layer (interlayer). For automotive applications, the most commonly used bonding layer or interlayer is polyvinyl butyl (PVB). In addition to polyvinyl butyl, ionoplast polymers, ethylene vinyl acetate (EVA), cast in place (CIP) liquid resin and thermoplastic polyurethane (TPU) can also be used.

When laminated glass breaks, the bonding layer holds the shards of glass together, helping to maintain the structural integrity of the glass. The shards of broken glass tend to interlock much like the pieces of a jigsaw puzzle. A vehicle with a broken windshield can still be operated, often for an extended period if the damage is not in the vision zones ortoo extensive. The bonding layer also helps to prevent penetration by the occupant in the event of a collision and by objects striking the laminate from the exterior of the vehicle. Due to the lower cost and higher strength of tempered glass, tempered glass has been favored for all but the windshield position where tempered glass is not permitted. However, on some higher end vehicles, laminated glass has been used for the doors rather than tempered glass. This is at least in part to improve the safety and security of the occupants but also for the improved sound dampening that a laminate provides and to facilitate the use of heat reflecting coatings for solar control. Laminated glass has also been used for the side windows on some passenger vans, primarily to improve occupant retention in the event of a rollover accident.

With a laminated side window, intrusion time into the vehicle by an attacker is significantly increased. However, the time that it takes for an aggressive, determined attacker to penetrate a conventional laminate is measured in several seconds. A significant enough delay that might help to overcome the advantage of surprise and provide sufficient time for escape but still less than ideal. In the event of a rollover accident, glass that is not glued into the vehicle opening, has been found to be little better than tempered glass. Once the laminated glass breaks, it offers little resistance to ejection.

Another method used to improve the security of automotive windows is by means of a security film. A film comprised of a tough transparent plastic layer, coated with a clear optical adhesive, is bonded to the inside surface of the window. They are especially effective when used in conjunction with laminated glazing. The added thickness of the film may cause problem on movable glass as the seals are sized for the normal unmodified thickness of the glass. In addition, unless the glass is removed when the film is installed, it is not possible to apply the film to the portion of the glass that is inaccessible. This leaves an unprotected area around the periphery of the opening. While a laminate with a security film is far better than a tempered glazing which offers virtually no resistance to intrusion, we still we are only looking at a delay of several seconds and none of these solutions offer any protection at all against firearms.

Standard OEM (original equipment manufacturer) automobile glazing provides virtually no ballistic protection. An inexpensive 0.22 caliber rim fire revolver can easily deliver a fatal injury through tempered or laminated glass.

To provide even minimal protection from the typical types of firearms employed by criminals a true BRG is needed. It should be noted that the “B” in BRG stands for “ballistic” not “bulletproof’. There is no such thing as bullet-proof glass. If enough bullets strike the glazing it will eventually be penetrated. Likewise, a single bullet may have enough energy to penetrate the thickest and toughest glazing. However, levels of ballistic protection have been established by ASTM, the Underwriters Laboratory (UL), Euro national (EN) and the National Institute of Justice (NIL) all of whom have defined specific tests that a glazing must pass to be certified. Each standard defines a set of increasing threat levels that define the type of bullet strikes that the glazing can survive under controlled conditions.

By careful selection of materials, a glazing with a thickness in the range of 19 mm - 21 mm can provide protection from both small arms fire as well as intrusion. An added benefit is that the thicker laminated glazing will retain its structural integrity and remain in place protecting the opening in the event of a rollover accident.

Due to increases in crime, rising crime rates, political and social unrest, and the proliferation of handguns in some part of the world, the market for civilian vehicles fitted with BRG has been growing. However, the added cost to retrofit a vehicle with BRG can be quite substantial. The high cost has damped the market. It would be desirable to have every law enforcement vehicle equipped with BRG, but it is rare to find a police car with anything other than the standard OEM glazing due to the high cost. While there are other factors, cost is certainly a major one.

Military vehicles are designed, from conception, to have some level of ballistic resistance. A typical minimum glazing thickness is 19 mm. Glazing of up to and sometimes greater than 150 mm (up to 350 kg/m²) is required to withstand the high threat levels found on the battlefield. The window openings in these vehicles are designed to accommodate the thick heavy glazings required. Non-military vehicles, on the other hand, are designed to have a much lighter glazing with thicknesses in the 3 mm - 6 mm range.

Some civilian vehicles are available from the OEM with a factory installed BRG option. The process used in designing a BRG version of a vehicle is to adapt the glazing to fit the standard sheet metal opening rather than adapting the vehicle to the glazing. Also, a substantial portion of the civilian market is served by aftermarket companies who perform BRG retrofits. The aftermarket suppliers have no choice but to adapt the glazing to fit in the OEM vehicle with as few modifications made to the vehicle as possible.

Figure 5A shows a typical BRG cross section. A common approach to design the BRG version of an OEM glazing is to have an exterior glass layer that is the same size and shape as the original glazing. This first layer of the glazing, positioned on the vehicle exterior is known as the strike face 22.

The strike face 22 is backed with and laminated to a package 30 comprising additional layers. These layers have an offset 38 partially inboard of the outer edge of the strike face 22, and have less surface area than the strike face 22. This smaller, offset 38 of additional layers of the laminate is known as the “package” 30. For a fixed glazing, the larger strike face 22 overlaps the sheet metal flange 34 (illustrated in Figure 7), to which the glazing is glued. The package 30 is located inboard of the flange 34 and is smaller that it.

While there are multiple layers in a BRG laminate, when we have a non-movable fixed BRG glazing, the exterior strike face 22 layer is the one that is bonded to the vehicle sheet metal 34 by means of a structural adhesive 36 (shown in Figure 7) and the layer that supports the weight of the part. A 19 mm thick BRG can weigh as much as 45 kg per square meter. This compares to 13 kg for a typical 5.4 mm windshield. As a result, the exterior strike face layer of the BRG must be very strong.

With movable glazing, such as door windows, the same approach is taken. The outer layer mounts into the window sheet metal and channel 32 (shown in Figure 6) used by the original glass to the greatest extent possible. The original channel 32 may need to be replaced or modified to accommodate the greater thickness of the BRG. The glazing may also need to become fixed as the window regulator motors and structure will not be strong enough for the greater weight of the BRG.

While the strength of glass can be increased by means of thermal tempering, this is not done for the strike face as a tempered layer will experience total failure upon impact.

Chemically tempered glass does not fail in the same way but also is not typically used for the strike face layer as it is necessary to print an obscuration 6 on the strike face to hide the mounting means and the outboard edges of the package. The typical black enamel frit obscuration 6 is screen printed on the flat glass prior to bending. However, once the glass has been printed and bent with a black enamel frit, it cannot be chemically tempered as the enamel will block the ion exchange required of the process. While black enamels are being developed that are compatible with the chemical tempering process, none are commercially available.

Black organic inks have been developed that can be applied to the bent glass after the chemical tempering process. However, the functional and aesthetic requirements of the black obscuration are difficult to meet with an organic ink. The organic inks are expensive as well as difficult and expensive to apply and not as durable as inorganic fired inks. The organic inks can only be applied after the glass has been bent and chemically tempered. The ink must be allowed to dry and cure before the laminate is assembled.

Other methods which have been tried including printing the obscuration on the plastic bonding interlayer or film and the use of an opaque plastic interlayer. However, these approaches require the use of an adhesion promoter as the dyes and pigments tend to interfere with the bonding of the interlayer to the glass and rigid plastic layers. It is also difficult to achieve the same level of opacity as achieved with a black frit. Another drawback is the much higher direct cost and lower throughput due to the added steps and higher labor required. In the case of a ballistic part where there is an offset between the outer layer edge of glass and the package 20, these solutions do not have the durability needed and tend to be easily damaged during handling and installation.

As a result, chemical tempering is not used for the strike face. For a 19 mm thick BRG, the strike face is typically comprised of soda-lime glass with a thickness in the range of 6 m - 8 mm with a black enamel frit obscuration.

Adding to the thickness is the additional reinforcement that is needed to provide ballistic protection along the edges of the package.

The glazing is especially vulnerable to attack along the portion of the strike face outboard of the package as only the thickness of the strike face stands between a bullet and the vehicle interior. To address this vulnerability, a thin metal frame 24 is bonded to the exterior glass layer. In the event of a projectile striking this area, the metal of the frame will stop it.

The frame, like a picture frame, surrounds and encloses an area. The frame has an outboard edge and an inboard edge. The portion of the frame enclosed and bounded by the inboard edge of the frame is typically filled by a filler layer of equal thickness. This layer may be comprised of glass, rigid plastic, or interlayer or any combination of glass, rigid plastic, and interlayer. This layer may itself be comprised of multiple layers. This filler layer and the frame are sandwiched between two layers of interlayer that bond them to the other layers of the laminate.

Therefore, in addition to the thickness of the outer glass layer, we have the thickness added by the frame and interlayer. While the frame may only be in the range of 1 mm - 3 mm thick, when added to the thickness of the glass, it becomes difficult to install without extensive and expensive modifications which leaves us with a glazing that is not flush if the sheet metal is not modified.

Another visual sign that a vehicle has BRG glazing comes from the typical wide black obscuration needed to hide the package and the frame. The problem with this wide obscuration is that this is yet another sign that the vehicle has been fitted with BRG. It also reduces the daylight opening and field of view of the glazing. On some small parts, such as rear quarter widows, very little is left of the visible area of the glazing. In part due to the relative low volume and minimal aesthetic requirements of most BRG programs, requirements for edge treatment, edge quality, mismatch, size control and surface control have all lagged that of OEM automotive parts. While the tolerances that high volume series production automotive glass must meet have been shrinking, BRG has remained largely the same. Much of the BRG in production today is produced on the same or equipment and by the same processes that were in use decades ago. As a result, there is noticeable mismatch between the layers of the BRG at the edge of each layer due to variation in size and shape. This is not an issue with military BRG where the primary criteria is the level of protection, but it is becoming increasingly undesirable on civilian BRG programs where the quality of standard automotive glazing has set higher expectations. To date this issue has been mitigated at least in part by camouflaging the edge of the package. Two methods are used to hide the mismatch and other irregularities. First, a black obscuration is printed on the strike face and made wide enough to hide the edge of the package from view from the exterior of the vehicle. Second, the package itself is sealed using a black plastic that fills the gaps making them less noticeable from the interior and exterior of the vehicle. Sealing is needed regardless as it also prevents the ingress of humidity and water which can result in delamination. A typical edge seal comprises a 3 mm thick black polyurethane.

It would be advantageous to be able to provide a BRG that did not have these limitations.

BRIEF SUMMARY OF THE DISCLOSURE

The BRG of the disclosure has a ballistic protection level of at least NIL lll-A. The BRG utilizes a thin chemically tempered strike face having a thickness of less than or equal to 3 mm rather than the 4 mm - 8 mm thick annealed glass typically used for BRG of similar rating. This thin strike face is bonded to a thin, rigid, ballistic frame. The combined thickness of the assembled strike face and frame, at the lll-A level, is less than 8 mm and preferably less than 7 mm and preferably less than 6 mm. The thickness of the typical automotive OEM glazing is in the 4 mm - 6 mm range which would be the ideal combined thickness of the frame and strike face.

The outer edge of the frame and strike face are substantially the same size and shape. With the added support of the frame, and through the use of chemically tempered glass, the thickness of the strike face is reduced. This allows the glazing to be installed without the extensive modification to the vehicle mounting means required with a thicker strike face and frame. The typical printed black enamel frit obscuration is replaced by a surface treatment applied to the frame. Treatments include but are not limited to engraving, etching, burnishing, brushing, printing, painting, patterning, embossing, and coating. Further multiple treatments may be needed. As an example, the frame can be painted and then have a complex graphic applied by water transfer printing on the frame.

The various layers of the laminate are cut and bent to automotive tolerances improving edge quality and layer alignment. During assembly, each layer is carefully aligned, and any excess interlayer is trimmed. This allows for a reduction in edge and lamination defects and for the width of the obscuration needed to be reduced. In addition, the obscuration width is further reduced by polishing the edges of the package to a smooth finish and applying a thin clear edge seal.

Higherthreat levels can be achieved by increasing the thickness of the package layers and/or by adding additional layers to the package. The thickness of the frame may also need to be increased to support the added weight.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1A Cross-section of a typical laminated glazing with black obscuration on surfaces 2 and 4.

Figure 1 B Cross-section of a typical laminated glazing with IR coating and film.

Figure 1C Cross-section of a typical tempered glazing.

Figure 2A Isometric view of the laminated glazing of the disclosure.

Figure 2B Side view of the laminated glazing of the disclosure.

Figure 3 Top view of the laminated glazing of the disclosure.

Figure 4 Exploded view of the laminated glazing of the disclosure.

Figure 5A Cross-section of the prior art.

Figure 5B Cross-section of the disclosure.

Figure 6 Cross-section showing interface with channel.

Figure 7 Cross-section showing interface with adhesive and sheet metal. Reference numerals of drawings

2 Glass.

4 Bonding/Adhesive layer/Plastic Interlayer.

6 Obscuration.

10 Rigid plastic layer.

12 Infrared reflecting film.

14 Chemically tempered glass.

16 Edge seal.

18 Infrared reflecting coating.

22 Strike face.

24 Frame.

26 Clear edge seal.

30 Package.

32 Channel.

34 Sheet metal.

36 Adhesive.

38 Offset.

66 Surface treatment.

68 Graphic.

101 Exterior side of glass layer 1 (201), number one surface.

102 Interior side of glass layer 1 (201), number two surface.

103 Exterior side of glass layer 2 (202), number three surface.

104 Interior side of glass layer 2 (202), number 4 surface.

201 Layer 1.

202 Layer 2.

203 Layer 3.

204 Layer 4. 205 Layer 5.

DETAILED DESCRIPTION

The present disclosure can be understood more readily by reference to the detailed descriptions, drawings, examples, and claims in this disclosure. However, it is to be understood that this disclosure is not limited to the specific compositions, articles, devices, and methods disclosed unless otherwise specified, as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing aspects only and is not intended to be limiting.

The following terminology is used to describe the laminated glazing of the disclosure.

The structure of the disclosure is described in terms of the layers comprising the glazing. The meaning of “layer,” as used in this context, shall include the common definition of the word: a sheet, quantity, or thickness, of material, typically of some homogeneous substance and one of several.

When multiple layers that vary widely in thickness are illustrated, it is not always possible to show the layer thicknesses to scale without losing clarity. Unless otherwise stated in the description, all figures are to be considered as for illustrative purposes and are not drawn to scale and thus shall not be construed as a limitation.

Typical automotive laminated glazing cross sections are illustrated in Figures 1A and 1 B. A laminate is comprised of two layers of glass, the exterior or outer, 201 and interior or inner, 202 that are permanently bonded together by a plastic layer 4 (interlayer). In a laminate, the glass surface that is on the exterior of the vehicle is referred to as surface one, 101 , or the number one surface. The opposite face of the exterior glass layer 201 is surface two, 102, or the number two surface. The glass 2 surface that is on the interior of the vehicle is referred to as surface four, 104, or the number four surface. The opposite face of the interior layer of glass 202 is surface three, 103, or the number three surface. Surfaces two, 102, and three, 103, are bonded together by the plastic layer 4. An obscuration 6 may be also applied to the glass. Obscurations are commonly comprised of black enamel frit printed on either the number two, 102, or number four surface, 104, or on both. The laminate may have a coating 18 on one or more of the surfaces. The laminate may also comprise a film 12 laminated between at least two plastic layers 4. In preferred embodiments, film 12 is an infrared reflecting film. Figure 1 C shows a typical tempered automotive glazing cross section. Tempered glazing is typically comprised of a single layer of glass 201 which has been heat strengthened. The glass surface that is on the exterior of the vehicle is referred to as surface one, 101 , or the number one surface. The opposite face of the exterior glass layer 201 is surface two, 102, or the numbertwo surface. The numbertwo surface, 102, of a tempered glazing is on the interior of the vehicle. An obscuration 6 may be also applied to the glass. Obscurations are commonly comprised of black enamel frit printed on the numbertwo, 102 surface. The glazing may have a coating 18 on the number one, 101 , and /or number two, 102 surfaces.

On laminated glazings with more than two layers, we shall continue the same numbing scheme incrementing the values from the last layer as each additional layer is added.

When describing the layers of a glazing, the convention used is to start with the layer that faces the exterior of the vehicle. This outermost layer is always layer one, 201 . Likewise, the major surface of layer one on the vehicle exterior is surface one, 101. The layer that faces the vehicle interior shall be the highest numbered layer and the interior major face (surface) of the layer shall be the highest numbered surface.

The term “glass” can be applied to many inorganic materials, include many that are not transparent. For this document we will only be referring to transparent glass. From a scientific standpoint, glass is defined as a state of matter comprising a non-crystalline amorphous solid that lacks the ordered molecular structure of true solids. Glasses have the mechanical rigidity of crystals with the random structure of liquids.

A glazing is an article comprised of at least one layer of a transparent material which serves to provide for the transmission of light and/or to provide for viewing of the side opposite the viewer and which is mounted in an opening in a building, vehicle, wall or roof or other framing member or enclosure.

The types of glass that may be used include but are not limited to the common soda-lime variety typical of automotive glazing as well as aluminosilicate, alkali aluminosilicate, lithium aluminosilicate, borosilicate, glass ceramics, and the various other inorganic solid amorphous compositions which undergo a glass transition and are classified as glass included those that are not transparent. The glass layers may be comprised of heat absorbing glass compositions as well as infrared reflecting and other types of coatings.

Laminated safety glass is made by bonding two layers of annealed glass together using a plastic bonding layer comprised of a thin sheet of transparent thermoplastic. Bullet Resistance Glazing is a type of safety glass that stops bullets by absorbing and dissipating the kinetic energy of the projectile and by deforming the projectile. Ideally, the bullet will not penetrate the glazing completely and neither will any fragments of the bullet or the glazing itself. Projectiles are made of metals that are relatively soft as compared to most types of glass. Upon impact with the harder surface, the bullet will begin to deform. Ordinary soda lime glass is brittle and has an extremely high compressive strength that the projectile must overcome before the glass will begin to yield. Once that occurs, the glass begins to crush and fracture. As the glass layer is crushed, the adjacent soft interlayer and rigid plastic layers undergo plastic and elastic deformation. As the plastic is displaced and compressed the energy is further absorbed. The discontinuity between the much greater mass of the glass versus the plastic also helps by reflecting the shockwave of the impact. If the first glass and rigid plastic set of layers is penetrated, the cycle repeats at a lower energy level at the next set of layers but with the projectile deformed and its surface area increased. By selectively placing layers of material with different properties, the energy of the bullet is absorbed and prevented from penetrating to the vehicle interior and from producing high energy spalling of the interior glazing layers sufficient to cause injury.

More problematic are multiple hits. Some of the standards dictate that to be certified to a certain threat level, the glazing must survive three strikes at maximum distance from each other of 120 mm forming an equilateral triangle. The U.S. National Institute of Justice (NIL) requires the glazing to take five equally spaced hits without penetration. At the NIL lll-A level, the BRG must provide protection against most handguns including 22 long rifle, 38 special, 9 mm submachine gun, 44 magnum, and 357 magnums as well as 12-gauge shotgun 00 buckshot.

The glass/ceramic/plastic protective layers are carefully selected based upon the threat level and standards that must be meet. While the performance of the various materials is well understood the challenge is producing compliant glazing while optimizing optical quality, weight, thickness, and cost.

The nominal threat level required for most civilian applications is lll-A which can be met with a typical BRG thickness of approximately 21 mm. Higher threat levels can be met by increasing the thickness of the layers and/or by adding additional layers.

Protective layers are bonded to one other using a thermo-plastic or laminating resin. Specifically, a plastic bonding layer 4, also referred as an interlayer, is employed to bond the major faces of adjacent layers together. This interlayer plays is typically a clear thermoset plastic material. In alternative embodiments, the interlayer material may be selected from a variety of options, such as polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), or ionomer resins. The choice of interlayer material may depend on various factors, including the desired level of transparency, durability, and resistance to impact or other types of stress. Additionally, different types of thermoplastic or laminating resins may be used to bond the protective layers, depending on the specific requirements of the application.

The present disclosure includes glass layers that may be either annealed or strengthened to increase the strength of glass. Strengthening can be achieved through two processes: thermal strengthening, which involves rapid cooling (quenching) of hot glass, or chemical tempering, which utilizes an ion exchange chemical treatment. This process is often referred to as toughening or tempering, rather than "strengthening."

Heat strengthened, full temper soda-lime float glass, with a compressive strength in the range of at least 70 MPa, can be used in all vehicle positions other than the windshield. Heat strengthened (tempered) glass has a layer of high compression on the outside surfaces of the glass, balanced by tension on the inside of the glass which is produced by the rapid cooling of the hot softened glass. When tempered glass breaks, the tension and compression are no longer in balance and the glass breaks into small beads with dull edges. Tempered glass is much stronger than annealed laminated glass. The thickness limits of the typical automotive heat strengthening process are in the 3.2 mm to 3.6 mm range. This is due to the rapid heat transfer that is required. It is not possible to achieve the high surface compression needed with thinner glass using the typical blower type low pressure air quenching systems.

In the chemical tempering process, ions in and near the outside surface of the glass are exchanged with ions that are larger. This places the outer layer of glass in compression. Compressive strengths of up to 1 ,000 MPa are possible. The typical methods involved submerging the glass in a tank of molten salt where the ion exchange takes place. The glass surface must not have any paint or coatings that will interfere with the ion exchange process.

The terms “left,” “right,” “front,” and “rear” are defined relative to an occupant of the vehicle seated and facing in the normal forward direction of the vehicle. This provides a consistent frame of reference for describing the various features of the disclosure. Inboard and outboard are relative to the center of the glazing with inboard being the direction from the edge of the glazing towards the center and outboard from the edge of glass in the direction away from the center of the glazing.

The black frit print obscuration on many automotive glazings serves both a functional and an aesthetic role. The opaque black print on the glass serves to protect the poly-urethane adhesive used to bond the glass to the vehicle from ultra-violet light and the degradation that it can cause. It also serves to hide the adhesive from view from the exterior of the vehicle. The black obscuration must be durable, lasting the life of the vehicle under all exposure and weather conditions. Part of the aesthetic requirement is that the black has a dark glossy appearance and a consistent appearance from part to part and overthe time. A part produced today must match up with one that was produced and in service 20 years ago. The parts must also match up with the other parts in the vehicle which may not have been fabricated by the same manufacturer or with the same formulation of frit. Standard automotive black enamel inks (frits) have been developed that can meet these requirements.

Other means are sometimes used to provide an obscuration when a black frit is not practical as is the case when the substrate will be chemically tempered, or the surface has been coated with a coating that is not compatible with the printing process. These include but are not limited to organic inks, primers and printed interlayer.

The water transfer printing process is a relatively new technology that was first commercialized in the 1980s. It has the primary advantage of being able to transfer complex graphics to curved or irregular surfaces. In the process, the graphic is printed on a PVA film. The film is then placed on the surface of water in a dipping tank. The film is then sprayed with an activator solution which dissolves the film. The substrate is then dipped into the tank, passing through the ink, and transferring the floating graphic to the substrate. The ink is formulated to adhere to the substrate. Other methods of painting and printing may be used with the water transfer process to achieve a wide range of aesthetics ranging from a glass black emulating a traditional black frit to simulated carbon fiber or stainless steel for a more modern, high-tech appearance.

The layers of the laminate may be cut to size by any suitable means. The most common method used to cut flat glass is the score and snap method. Glass, being a brittle material, cannot be cut in the same manner as non-brittle materials. Glass does not undergo plastic deformation at room temperature. A wheel or scribe comprised of a material that is harder than the glass being “cut” is used to create a shallow score line. Along the score line, the surface of the glass is in effect crushed. The score traces the desired shape upon the flat glass. The glass is then placed in tension and the score line acts as a stress concentrator, allowing the glass to fracture along the score line.

After cutting, especially with the score and snap method, a diamond wheel or similar abrasive wheel grinder is typically used to break the sharp edge of the cut glass and to improve the aesthetics, strength, and quality of the edge. Grinding wheels are also used to give the edge a specific shape, bevel, radius, or angle.

In most BRG glazing, a rigid plastic layer 10 is placed on the interior-facing side of the vehicle to prevent spalling, which can occur with a glass layer. In thinner Level lll-A BRG, typically with a thickness range of 19 mm, only one rigid plastic layer is used. However, to reduce weight, it has surprisingly been found that the total glass thickness can be reduced while maintaining or improving the level of protection by adding a second rigid plastic (as shown in Figures 6 and 7) to the laminate. As the rigid plastic is approximately half the density of glass, the reduction in weight can be substantial. A 45 kg per square meter laminate can be reduced to as little as 36 kg per square meter.

Thin, chemically tempered glass, with a thickness of less than 1 mm and typically less than 0.5 mm has become ubiquitous in cellular phones, table, and laptop screens due to its low weight, high strength, and resistance to scratching.

However, as discussed, chemically tempered glass is not typically been used in the strike face as it cannot be painted with a black enamel frit due to incompatibility with the chemical tempering process. A major drawback to ordinary annealed soda-lime glass is that no matter how thick the other layers may be, the exposed strike face is just as susceptible to damage from impact as ordinary OEM glazing. In some cases, there the OEM glazing is tempered, even more so.

With no need to print on surface two 102 of the strike face, the strike face 22 of the glazing of the disclosure is comprised of chemically tempered glass 14 with a thickness that is less than or equal to 3 mm. This thin chemically tempered glass layer is much stronger than the thicker annealed glass that it replaces. But it cannot but itself securely support the weight of the package, especially at the greater weight that comes with higher threat level cross sections. The thin outer glass strike face 22 layer is further strengthened and reinforced by bonding the glass to a rigid frame 24 which is designed to enable the strike face to fully support the weight of the package even at the highest threat levels. Thus, a strike face with a thickness that if far too thin to support a level IV package can be used. In effect, the thin glass of the strike face is more of a veneer used to give the BRG the appearance of a standard OEM glazing. As the weight of the package and the threat level increases, the metal frame thickness must increase and/or a stronger material must be used. A level lll-A mild steel frame may need to be increased in thickness or the steel upgraded to a tougher steel type. The thin strike face presents minimal resistance to the projectile but his is more than compensated for by the modifications made to the other layers. The frame 24 is comprised of metal but may also be fabricated from any other non-metal ballistic material or combination thereof. In some embodiments, the frame may be comprised of layers of more than one material, such as a high strength steel, a polyamide fabric or a combination thereof.

Additional embodiments of the frame may include other non-metallic materials, such as ceramics or composites. The specific materials used may depend on the desired ballistic performance and weight of the frame. In some embodiments, the frame may be designed to provide additional functions, such as mounting points for vehicle components or structural reinforcement.

The combined thickness of the frame 24, strike face 22 and the bonding interlayer 4 used to permanently bond the strike face to the frame, at a lll-A threat level is less than 8 mm, preferably less than 7 mm and preferably less than 6 mm. This same thickness range can be maintained at higher threat levels with the appropriate frame design.

In addition to its ballistics function, the surface of the frame 24 serves as the obscuration 6 in which case is treated to improve tis aesthetics . Any type of metal surface treatment 66 may be used, such as painting the frame with a gloss black, emulating a printed black enamel. For more complex designs, the water transfer printing process may be used to apply a complex, multi-color graphic on the frame. The painting may be applied to any side of the frame, but is preferably performed in the external face of the frame (as illustrated in Fig. 5b) or in the internal face of the frame (not shown in the figures). In preferred embodiments, the painting is applied by the water transfer process in the interior face of the frame.

Overlapping the inboard edge of the frame with the package decreases the daylight opening and so overlap is kept at a minimum. However, some overlap may be required to meet the rated threat level and to provide the level of stiffness needed to support the package. The inboard edge of the frame 24 may be flush with the package 30, or it may be inboard of the package 30 by some distance as shown in Figures 5B, 6 and 7. Preferably, no more than 18 mm, preferably no more than 12 mm, preferably no more than 6 mm. The exact value will depend upon the specific application and cross section.

The various layers of the laminated BRG glazing disclosed are cut to size from flat sheets.

The glass layers of the BRG laminate of the disclosure are first ground to a smooth stain finish with a diamond wheel grinder as is standard practice. The edges are further polished using a finer grit wheel or with a buffer and polishing compound. Polishing may be done prior to bending and lamination or after. The glass and rigid plastic layers are then bent to their final shape by a variety of methods known in the art.

Modern automated automotive glass manufacturing equipment and process are used to cut and form the glass layers.

The total tolerance range, for alignment between the layers of the laminate is preferably less than 6 mm, preferably less than 4 mm and preferably less than 3 mm.

The formed glass 2, rigid plastic layers 10 and plastic interlayers 4 are assembled and laminated.

After lamination, any excess interlayer is removed from the laminate.

The last step is to seal the edges of the package using a clear sealer.

In generally, with three glass layers including a chemically tempered strike face and two rigid plastic layers and with a total thickness of approximately 21 mm, the laminate will meet level lll-A. The thicknesses of each layer can vary over a narrow range from that of embodiments one and two. In embodiments, one and two, for the glass-to-glass interlayers, standard TPU in 0.5 mm to 1 .5 mm, preferably 0.5 mm or 1 .0 mm may be used. The strike face can range from 1 .0 to 3.0, preferably from 1 .5 mm to 3.0 mm. Layer two, 202, which can comprise, glass, rigid plastic, or interlayer, needs to be the same thickness as the frame. Glass layer three, 203 ranges from 4.5 mm to 5.5 mm. The two poly carbonate layers 204/205 range from 2.0 mm to 3.5 mm and do not need to be the same thickness. A thicker TPU layer ranging from 2.5 mm to 3.5 mm is needed between the poly carbonate layers.These thicknesses are suggested ranges and are not to be construed as limitations unless otherwise claimed.

Higher threat levels can be achieved by increasing the thickness of the layers, by changing the materials, by increasing the number of layer or by a combination of the three.

DESCRIPTION OF EMBODIMENTS

1 . Embodiment one: Corresponds to a large rear side window used in a full-sized civilian SUV. The original 5 mm thick tempered OEM glazing is fixed and glued to the flange of the body sheet metal 34 by a polyurethane adhesive 36. Various views of the BRG replacement are shown in Figures 2A, 2B, 3, 4 and 7.

The strike face 201 of the replacement BRG is comprised of a thick, chemically tempered, soda-lime glass 14 having a thickness between 1 to 3 mm, preferably 2 mm. The strike face 201 is cut to the same size as the original OEM glazing that it replaces. The strike face 22 is reinforced by a thick high strength steel frame 18 having a thickness between 1 to 3 mm, preferably 2mm.

Prior to assembly of the laminate, a gloss black coating 66 is applied to the frame 18. After the coating 66 is cured, a water transfer printing process is used to apply a graphic 68 to the frame 18. The graphic 68 gives the frame the appearance of carbon fiber. The strike face 22 and the frame 18 have the same size and shape along their outboard edges. The inboard edge of the frame 18 is offset 38 by 50 mm from the outboard edge giving it the same width as the black obscuration 6 printed on surface two 102 the OEM glazing.

The strike face 22 and the frame 18 are permanently bonded to each other during the lamination process by a sheet of TPU thermoplastic 4 having a thickness between 0.5 to 1 .5 mm, preferably 1 mm. The area inboard of the frame 18 is filled by a thick glass 2-layer 202 cut to exactly fit the opening in the frame having a thickness between 1 to 3 mm, preferably 2 mm. Layer three 203 of the laminate comprises a thick soda lime glass 2 having a thickness between 5 to 6 mm, preferably 5.5 mm. Layers four 204 and five 205 are comprised of thick polycarbonate having a thickness between 1 to 3 mm, preferably 2.5 mm. Layer two is bonded to layer three by a thick sheet of TPU having a thickness between 0.5 to 1 .5 mm, preferably 1 mm. Layer three 203 is bonded to layer four 204 by a thick layer of TPU 4 having a thickness between 0.5 to 1 .5 mm, preferably 1 mm. Layer four 204 is bonded to layer five 205 by a thick layer of TPU 4 having a thickness between 1 to 2 mm, preferably 2 mm. Layers three 203, four 204, and five 205 are each cut smaller than layers one 201 and two 202 offset 38 from the outboard edge of the strike face 22 by 40 mm. As a result of this offset 38, the frame 18 is partially embedded in the laminate by the overlap of the package 30. This overlap provides a high level of protection from projectiles impacting along point where the package 30 joins the strike face 22.

The total combined thickness of the strike face 22, TPU interlayer 4 and frame 18 is between 5 to 6.5 mm, preferably 5 mm, the exact same as the OEM glazing allowing the BRG to be mounted in the vehicle with surface one 101 flush with the vehicle exterior sheet metal 34. The total thickness of the BRG is between 18 to 20 mm, preferably 19.5 mm. While an additional rigid plastic layer and additional interlayer is added, the total thickness of the glass layers are reduced so as to allow the total thickness to remain approximately the same as the BRG of the prior art. The BRG is certified to full level lll-A ballistic protection. The flat sheets of the various materials are all machine cut by mean of computer controlled cutting machines holding a tolerance of +/- 0.25 mm. The edges of glass and plastic layers are ground and polished.

The layers are carefully assembled, minimizing any mismatch from layer to layer, holding variation from edge to edge to less than +/- 1 .5 mm.

After lamination of the glazing, the edge of the package 30 are sealed using the flexible polymer, such as clear polyurethane, and the rigid polymer, such as CPET. The distance of the total edge offset 38 is between 1 .5 to 2.5 mm. It should be noted that the total edge offset 38 distance can also be adjusted to meet specific requirements of the OEMs.

2. Embodiment two: shown in Figure 6, is similar to embodiment one. Embodiment two is the BRG that replaces the front door glass of the same large SUV of embodiment one. The shape is different, but the same cross section is maintained. The offset 38 of the package 30 in this case is smaller as the glazing along the front, rear, and top edges, is mounted into a channel in the door frame. The offset in this case is 12 mm. The width of the frame is 24 mm with an overlap of 12 mm with the package. The same clips and mounting rail, used with the original OEM glazing can be used to mount the BRG. The regulator motors must be replaced for the BRG to be able to move up and down. The top and sides of the door frame and the channel inside do not need to be modified or replaced. The same exterior belt line seal is used with the BRG although the interior door panel, trim and seals must be modified due to the greater thickness.

3. Embodiment three: is similar to embodiment one. The strike face glass layer thickness remains between 2 and 3 mm, preferably at 2 mm with the frame increases to a thickness between 5 to 7 mm, preferably 6mm. The area inboard of the frame 18 is filled by a 6 mm thick glass 2 layer 202 cut to exactly fit the opening in the frame. The thickness of the remaining glass and rigid plastic layers are each increased by 25%. This increases the level of protection. The inboard edge of the frame 18 is offset 38 by 60 mm from the outboard edge for a greater overlap with the package which is needed to meet the higher threat level and to support the increased package weight.

Claims

CLAIMS A vehicle laminated glazing, comprising: a strike face layer with two major surfaces and an edge; ; at least two rigid layers; a plurality of plastic bonding interlayers permanently bonding the layers of the laminate to each other; a metal frame bonded to said strike face layer having an inboard edge and an outboard edge, wherein said frame comprises a surface treatment; a package comprised of said plurality of plastic bonding interlayers and at least one glass layer and at least one rigid layer; wherein said package is bonded to said frame and first glass layer; and wherein the edge of said package is offset inboard from the edge of the fist glass layer along at least a portion of said edge. The laminated glazing of claim 1 , wherein the inboard edge of the frame overlaps the edge of the package by less than 24 mm. The laminated glazing of any of the preceding claims, wherein the combined thickness of said frame, first glass layer and interlayer is less than or equal to 8 mm, preferably less than or equal to 7 mm, preferably less than or equal to 6 mm. The laminated glazing of any of the preceding claims, wherein the edges of the layers of the package align to each other having a total tolerance range of no greater than 6.0 mm, preferably of no greater than 4.0 mm, preferably of no greater than 3 mm. The laminated glazing of any of the preceding claims, wherein the edges of the layers of the package or the edges of the glass and rigid plastic layers of said package are polished. The laminated glazing of any of the preceding claims, wherein the edges of the package are sealed by means of a clear edge sealer. The laminated glazing of any of the preceding claims, wherein the edges of the package are sealed using at least one of the materials including: CPET, clear PU or acrylic. The laminated glazing of any of the preceding claims, wherein the frame extends inboard of the package along a substantial portion of the inboard edge of the frame by 18 mm, preferably by 12 mm, preferably by 6 mm. The laminated glazing of any of the preceding claims, wherein the layer of the laminate inboard of edge of the frame, in the same plane as the frame and having an outboard edge adjacent to that of the inboard edge of the frame is comprised of at least one of the materials including: glass, hard plastic, interlayer or the combination thereof. The laminated glazing of any of the preceding claims, wherein the surface treatment of the frame is comprised at least one method selected from the following: printing, painting, patterning, embossing, or coating. The laminated glazing of any of the preceding claims, wherein a graphic is printed on the frame. The laminated glazing of any of the preceding claims, wherein the graphic is printed by means of a water transfer printing process. The laminated glazing of any of the preceding claims, wherein the frame obscures the outboard edge of the package when viewed from the exterior of the vehicle. The laminated glazing of any of the preceding claims, wherein the frame obscures the adhesive bonding the glazing to the vehicle from view from the exterior of the vehicle. The laminated glazing of any of the preceding claims, wherein the metal frame is bonded to the strike face layer by means of the plastic bonding interlayers. The laminated glazing of any of the preceding claims, wherein the metal frame serves to obscure at least a portion of the outboard edge of the package from view and serves to obscure at least a portion of the adhesive used to bond said laminated glazing to the vehicle opening. The laminated glazing of any of the preceding claims, wherein the outboard edge of the metal frame and the edge of the first glass layer have the same size and shape along at least half of the periphery. The laminated glazing of any of the preceding claims, wherein the thickness of the strike face layer is equal or less than 3 mm. The laminated glazing of any of the preceding claims, wherein the strike face layer is sized to fit the vehicle’s opening and mounting means. The laminated glazing of any of the preceding claims, wherein the strike face layer is chemically tempered. The laminated glazing of any of the preceding claims, wherein the at least two rigid layers are plastic.