AND THE ARTICLES MADE THEREFROM

CROSS REFERENCE TO TECHNICALLY RELATED CASE

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial

No. 62/168,070 filed May 29, 2015. The related application is incorporated herein in its entirety by reference.

BACKGROUND

[0002] Many glazing systems used in transportation vehicles are flat, though some glazing systems with a curvature have been formed. Currently, when three dimensional curves are desired for design or functional reasons, the individual curved layers (for example, a curved glass sheet and a curved polymer sheet) are laminated together to form the curved glazing. This process is cumbersome and requires multiple forming steps to form the respective curved sheets, where the curvature of the separate sheets has to match in order to ensure good adhesion.

[0003] An improved window system comprising a polymer is therefore desired, for example, that is less prone to scratches, chemical attack, and capable of passing one or more of the Federal Aviation Regulations, the European Regulations, the British Regulations, and the Federal Railway Regulations. It is also desirable for this window system to have the capability of being curved with a minimal number of process steps.

BRIEF DESCRIPTION

[0004] Disclosed herein is a method for making a multilayer article and the article.

[0005] In an embodiment, a method of making a curvilinear multilayer article comprising: preparing a multilayer stack comprising a first hardened glass layer, a first polymer layer, and a first interlayer located in between the first hardened glass layer and the first polymer layer; deforming the multilayer stack to form a curvilinear multilayer stack; increasing a temperature of the curvilinear multilayer stack from a first temperature to a second temperature and increasing a pressure exerted on the curvilinear multilayer stack from a first pressure to a second pressure; and reducing the temperature to a reduced temperature and reducing the pressure to a reduced pressure to form the curvilinear multilayer article; wherein the first hardened glass layer comprises a strengthened glass having a surface compressive stress of 250 to 1 ,000 MPa and a depth of layer of compressive stress of greater than or equal to 40 μηι; wherein the first polymer layer comprises a polysiloxane, a polyester, a polycarbonate, an acrylic, an acrylonitrile butylstyrene, a nylon, a polybutylterephthalate, a polyetherimide, a poly(ether ether ketone), a poly(l,4-cyclohexane-dimethanol-l,4-cyclohexanedicarboxylate ), or a composition comprising one or more of the foregoing; wherein the first hardened glass layer is 0.3 to 1.5 mm, the first interlayer is 0.2 to 1.4 mm, and the first polymer layer is 0.1 to 15 mm. [0006] In another embodiment, a curvilinear multilayer article comprises a first hardened glass layer, a first polymer layer, and a first interlayer located in between the first hardened glass layer and the first polymer layer; wherein the first hardened glass layer comprises a strengthened glass having a surface compressive stress of 250 to 1 ,000 MPa and a depth of layer of compressive stress of greater than or equal to 40 μηι; wherein the first polymer layer comprises a polysiloxane, a polyester, a polycarbonate, an acrylic, an acrylonitrile butylstyrene, a nylon, a polybutylterephthalate, a polyetherimide, a poly(ether ether ketone), a poly(l,4-cyclohexane- dimethanol-l,4-cyclohexanedicarboxylate), or a composition comprising one or more of the foregoing; wherein the first hardened glass layer is 0.3 to 1.5 mm, the first interlayer is 0.2 to 1.4 mm, and the first polymer layer is 0.1 to 15 mm.

[0007] The above described and other features are exemplified by the following figures and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The following is a brief description of the drawings wherein like elements are numbered alike and which are presented for the purposes of illustrating the exemplary embodiments disclosed herein and not for the purposes of limiting the same.

[0009] FIG. 1 is an illustration of a cross-section of a single sided multilayer article;

[0010] FIG. 2 is an illustration of a cross-section of a dual sided multilayer article;

[0011] FIG. 3 is an illustration of a cross-section of a double paned multilayer article comprising single sided articles;

[0012] FIG. 4 is an illustration of a cross-section of a double paned multilayer article comprising dual sided articles;

[0013] FIGs. 5-6 are illustrations of embodiments of multilayer articles; and

[0014] FIG. 7 is an illustration of a method of making a multilayer article.

DETAILED DESCRIPTION

[0015] Curved window panes comprising a polymer composition are difficult to form and curved window panes that can pass flammability tests according to one or more of the Federal Aviation Regulations (FAR), the European Regulations (ER), and British Regulations (BR) and/or that can meet one or both of the ballistic and block tests of the Federal Railway Regulations (FRR) are particularly desirable. It was surprisingly discovered that a curvilinear multilayer article (also referred to as a multilayer article or an article) could be formed by imparting a curvature to a multilayer stack comprising at least a hardened glass, an interlayer, and a polymer layer under increased temperature and pressure. The multilayer article can achieve a radius of curvature of less than or equal to 50 centimeters (cm), specifically, less than or equal to 25 cm, more specifically, less than or equal to 10 cm as determined by a three point bend test. The multilayer article can achieve a radius of curvature of greater than 0, specifically, greater than or equal to 0.5 cm, more specifically, greater than or equal to 1 cm as determined by a three point bend test. The multilayer layer article can have a curvature in more than one direction. For example, the curvature can have concave and a convex curvature with respect to an axis. The curvature can be with respect to two or more axes. The multilayer article is light weight as compared to their glass window pane counter parts, it provides good scratch resistance, and is surprisingly capable of maintaining its formation curvature without returning to its original flattened shape and, for example, without even springing back to a position that was flatter than the formation curvature. Without being bound by theory, it is believed that as long as the stress imparted on the multilayer article during the curving does not exceed the compressive stress in the glass layer, then the formation curvature can be maintained after forming.

[0016] It was surprisingly found that the multilayer article was capable of passing various impact tests, even in the curved portion of the article. For example, a dual sided multilayer article was able to pass an impact test according to a pendulum test, ANSI Z97.1-2009, with a 45.4 kg mass dropped from a height of 1 ,220 mm. The fact that the curvilinear article could pass an impact test was especially surprising as one skilled in the art would have thought that deforming (e.g., curving) a glass layer would add a stress to the glass layer that would inherently make the article weaker. This belief is in part why curved glass parts are initially formed in a curved position (i.e., they are not formed and then curved).

[0017] It was further surprisingly found that the multilayer article can pass one or more of the flammability tests according to one or more of the FAR, the ER, and BR and/or that can pass one or both of the ballistic and block tests of the FRR. These regulations are difficult for polymer compositions to pass and, to date, it is believed that all window panes comprising a polymer have failed the BR.

[0018] The multilayer article can be a piece of furniture or a part of a building. The multilayer article can be a window pane, for example, for use in a train, an aircraft, a bus, a car, a truck, an agricultural vehicle, a water vessel, a microwave oven door, an oven door, a light, a refrigerator shelf, a refrigerator door, or a display screen (such as a television screen, an entertainment screen (for example, on an airplane, specifically, on a seat back of an airplane seat), a mobile device, and the like). The multilayer article can be used as a door (such as rail, platform, elevator, and cabinet doors). It is envisioned that the multilayer article will meet the needs for building and construction glazing.

[0019] The multilayer article can be a single sided article that comprises a glass layer, a polymer layer, and an interlayer located in between. FIG. 1 illustrates a single sided multilayer article 2 with polymer layer 30 that has polymer side 32 and polymer side 34; interlayer 20 that has interlayer side 22 and interlayer side 24; and glass layer 10 that has glass side 12 and glass side 14. FIG. 1 illustrates that glass side 14 is in direct contact with interlayer side 22 and interlayer side 24 is in direct contact with polymer side 32. The total thickness of a single sided multilayer article can be 1 to 100 mm, specifically, 1 to 20 mm, more specifically, 2 to 14 mm. A decorative and/or functional layer can be disposed onto polymer side 32 and/or 34. A decorative and/or functional layer can be disposed onto interlayer side 22 and/or 24. A decorative and/or functional layer can be disposed onto glass side 14 and/or 12. A decorative and/or functional layer can be disposed onto polymer side 32 and/or 34 and glass side 14 and/or 12. A decorative and/or functional layer could be disposed onto glass side 12 and/or polymer side 34 separately or in addition to having decorative layers on the aforementioned layers of the multilayer article.

[0020] The multilayer article can be a dual sided article that comprises a polymer layer with a polymer side A and a polymer side B; a first glass layer located on the polymer side A with a first interlayer located in between the first glass layer and the polymer layer; and a second glass layer located on the polymer side B with a second interlayer located in between the first glass layer and the polymer layer. FIG. 2 illustrates a dual sided multilayer article 4 with polymer layer 30 that has polymer side 32 and polymer side 34; interlayer 20 that has interlayer side 22 and interlayer side 24; interlayer 40 that has interlayer side 42 and interlayer side 44; glass layer 50 that has glass side 52 and glass side 54; and glass layer 10 that has glass side 12 and glass side 14. FIG. 2 illustrates that glass side 14 is in direct contact with interlayer side 22; interlayer side 24 is in direct contact with polymer side 32; polymer side 34 is in direct contact with interlayer side 42; and interlayer side 44 is in direct contact with glass side 52. It is noted that one or both of glass layers 10 and 50 comprise hardened glass. The total thickness of a dual sided multilayer article can be 1 to 100 mm, specifically, 1 to 20 mm, more specifically, 2 to 14 mm. A decorative and/or functional layer can be disposed onto polymer side 32 and/or 34. A decorative and/or functional layer can be disposed onto glass side 14 and/or 52. A decorative and/or functional layer can be disposed onto interlayer side 22 and/or 24. A decorative and/or functional layer can be disposed onto interlayer side 42 and/or 44. A decorative and/or functional layer can be disposed onto polymer side 32 and/or polymer side 34 and/or glass side 14 and/or glass side 52. A decorative and/or functional layer can be disposed onto glass side 12 and/or 54 separately or in addition to having decorative layers on the aforementioned layers of the multilayer article.

[0021] The multilayer article can be a double pane article comprising a first and a second pane with a gap located therebetween. The double pane article comprises at least one single sided multilayer or at least one dual sided multilayer pane. The second pane can be, for example, a single sided multilayer, a dual sided multilayer pane, a glass pane, or a polymer pane. The gap can be 4 to 100 mm, specifically, 5 to 20 mm, more specifically, 6 to 14 mm. The gap can comprise a liquid or gas such as argon to improve insulation properties. It is also contemplated to decorate and/or functionalize any and/or all layers and sides within this construction.

[0022] The double pane article can comprise two single sided multilayers, where the polymer layers of each of the single sided multilayers can be in contact with a gap located in between the two panes. For example, FIG. 3 illustrates a double pane article comprising two single sided multilayers 2 and 102 with gap 90 located in between. FIG. 3 illustrates first glass layer 10 and first polymer layer 30 with first interlayer 20 located in between first glass layer 10 and first polymer layer 30; fourth glass layer 110 and second polymer layer 130 with fourth interlayer 120 located in between fourth glass layer 110 and second polymer layer 130; and gap 90 located in between polymer layers 30 and 130. It is noted that one or more of glass layers 10 and 110 can comprise hardened glass. It is also contemplated to decorate and/or functionalize any and/or all layers and sides within this construction.

[0023] The double pane article can comprise two dual sided multilayers with a gap located therebetween. For example, FIG. 4 illustrates a double pane article comprising two dual sided multilayers 4 and 104 comprising first polymer layer 30 and first polymer layer 130, respectively. Second glass layer 50 and third glass layer 150 are located next to gap 90 and first glass layer 10 and fourth glass layer 110 are the external surfaces of the double pane article. First interlayer 20 and second interlayer 40 are located in between first polymer layer 30 and first glass layer 10 and in between first polymer layer 30 and second glass layer 50, respectively. Fourth interlayer 120 and third interlayer 140 are located in between second polymer layer 130 and fourth glass layer 110 and in between second polymer layer 130 and third glass layer 150, respectively. It is noted that one or more of glass layers 10, 50, 150, and 110 can comprise hardened glass. It is also contemplated to decorate and/or functionalize any and/or all layers and sides within this construction.

[0024] The double pane article can have one pane with curvature and a second pane that is flat. The double pane article can comprise a frame or gasket around an outer edge of the first pane and the second pane, where the first pane, the second pane, and the frame or gasket can form a gap located in between the two panes.

[0025] FIG. 5 is an illustration of a multilayer article 200. Article 200 can be a single pane article or a double pane article. For example, line M of article 200 can be a cross-section line of any of the articles of FIGs. 1-4. FIG. 5 illustrates that multilayer article 200 can comprise a local region of curvature and a flat section. The hardened glass in the curved region can experience a tensile or compressive stress of greater than or equal to 170xl0 ⁶ pascals (Pa), or more specifically the tensile or compressive stress value of less than the value needed to break the glass due to bending.

[0026] One or more decorative layers for a single pane or double pane article can be applied to the polymer and/or interlayers and/or glass layers by methods including but not limited to screen printing, laser marking, roto gravure printing, pad printing, digital ink jet printing, hydrographies, laser etching, laser printing, decals, and transfer printing. If the polymer layer comprises two or more polymer layers, it is noted that one or more of the layers can comprise a decorative layer disposed on one or more sides of the respective polymer layers.

[0027] One or more functional layers for a single or double pane article can be applied to the polymer and/or interlayers and/or glass layers. The functional layer can include but is not limited to a conductive ink system, a dielectric ink system, a touch sensing system such as CIMA/SANTE technology, a defrost system, a reflective material (for example for a one-way or standard mirror), a heads up display system, an anti-glare coating, an anti-frost coating, an anti- fog coating, a haptic electronic, an LED lighting system, a printed electronic, an integrated circuit board, a wire mesh or otherwise conductive grid (for example, that is designed to block microwaves), or a combination comprising at least one of the foregoing.

[0028] The multilayer articles can be used in a confined or sealed area, such as, for example, the interior of an aircraft. In the airline transportation industry, useful flame retardant properties, in particular, the heat release rate, of thermoplastic materials is typically measured and regulated according to FARs, in particular FAR 25.853 (d). The heat release rate standard described in FAR F25.4 (FAR Section 25, Appendix F, Part IV) is one such specified property, and thermoplastic materials conforming to this standard are required to have a 2 minute (min) integrated heat release rate of less than or equal to 65 kilowatt-minutes per square meter (kW- min/m ² ) and a peak heat release rate of less than 65 kilowatts per square meter (kW/m ² ) determined using the Ohio State University (OSU) calorimeter, abbreviated as OSU 65/65 (2 min/peak). In some more stringent applications where a greater heat release rate performance is called for, a 2 minute integrated heat release rate of less than or equal to 55 kW-min/m ² and a peak heat release rate of less than 55 kW/m ² (abbreviated as OSU 55/55) can be required. In addition, for many applications, the thermoplastic materials need to have a smoke density (D _s ) as described in FAR F25.5 (FAR Section 25, Appendix F, Part V) of less than 200, measured after 4 minutes (min) in either flame or non-flame scenario, according to ASTM F814-83. In some embodiments, the multilayer articles can meet Bombardier SMP 800C and Boeing BSS 7239 for toxicity testing.

[0029] In some embodiments, the multilayer articles can meet the requirements of the Federal Railroad Administration (FRA) for ballistic threat and block threat. In some embodiments, the multilayer articles can pass the CFR 49, Chapter II, FRA, DOT, Part 223, Subpart B, Appendix A, Type I, Ballistic Threat using caliber .22 LR (long rifle), 40.0-grain, lead ammunition with a minimum impact velocity of 960 feet per second (fps) fired at the center of the test sample. In some embodiments, the multilayer article can pass CFR 49, Chapter II, FRA, DOT, Part 223, Subpart B, Appendix A, Type I, Block Threat using concrete blocks with a minimum weight of 25 pounds (lbs) suspended and then dropped 30 feet (9.14 meters (m)), 1 inch (2.54 cm) onto the center of the test sample.

[0030] In the transportation industry, useful flame retardant properties, in particular the heat release rate, of thermoplastic materials can be measured and regulated according to the European test standards EN45545 and ISO 5660. Accordingly, in some embodiments, the multilayer article can have a heat release according to EN45545 and ISO 5660 of less than 90 kilowatts (kW). In some embodiments, the multilayer article can have a fire propagation in accordance with EN45545 and ISO 5658-2 of greater than 20 kW. In some embodiments, the multilayer article can have a smoke density in accordance with EN 45545-2 and ISO 5659 for a smoke density at 240 seconds, where the multilayer article can have a smoke density of less than 300, and/or VOF ₄ , the article can have a the smoke density of less than 600. In some

embodiments, the multilayer article can have a toxicity level in accordance with ISO 5659-2 using Fourier Transform Infra Red (FT-IR) for gas analysis as required by EN45545-2 Annex C (50 kW) where the multilayer article can have a toxicity level with a conventional index of toxicity (CIT _G ), a summation term from the analysis of gases taken at 4 min and 8 min test duration of less than 0.9 for a hazard level (HL) 2 (HL2) rating or less than 1.2 for an HLl rating. There are four hazard levels (HL) with HL4 being the most stringent level and HLl being the least stringent level. Each hazard level has specific call outs for flame spread, ignitability, heat release, smoke emission, and toxic gas emissions. Hazard levels are based on 4 parameters that describe fire behavior: Ignitability-spread of flame (CFE: critical flux at extinguishment), maximum average heat release (MAHRE), Smoke emission (loss of visibility: DS4, VOF4), and Toxicity gas emission (CITQ).

[0031] In the transportation industry, useful flame retardant properties, in particular the flame spread and fire propagation, of thermoplastic materials can be measured and regulated according to the British test standards BS476 Part 7 and Part 6, respectively. Accordingly, in some embodiments, the multilayer article can have a flame spread of less than or equal to 165 mm according to BS476 Part 7. In some embodiments, the multilayer article can have a fire propagation of less than or equal to 12 according to BS476 Part 6.

[0032] In the transportation industry, useful flame retardant properties, in particular the smoke development and toxicity of the gases from a fire, of thermoplastic materials can be measured and regulated according to the British test standards BS 6853:1999 Annex D8.4 Panel Smoke test and Annex B.2 Toxicity test, respectively. Accordingly, in some embodiments, the multilayer article can have an Ao (On), where Ao is the Optical Density Value of the smoke of less than 2.6 and an Ao (off) of less than 3.9 according to BS 6853: 1999 Annex D8.4. Ao on stands for the maximum Ao value during the first phase of the test (the first 30 min) when the fire source is flaming; Ao off stands for the maximum Ao value during the second phase of the test (the last 10 min) when the fire source has gone out; and the higher the Ao value, the worse is the flame retardant properties. In some embodiments, the multilayer article can have a toxicity of less than 1 according to BS 6853:1999 Annex B.2.

[0033] The multilayer article can be opaque. The multilayer article can have excellent transparency. For example, the multilayer article can have a haze of less than 10% and a transmission greater than 70%, each measured using the color space CIE1931 (Illuminant C and a 2° observer), or according to ASTM D 1003 (2007) using illuminant C at a 0.125 inch (3.2 mm) thickness. A 1,467 mm by 1,215 mm test sample can have a maximum deflection of less than or equal to 5 mm at an applied load of 2,500 Newtons per meter squared (N/m ² ). A 1,512 mm by 842 mm test sample can have a maximum deflection of less than or equal to 5 mm at an applied load of 6,000 N/m ² .

[0034] At least one of the glass layers comprises a hardened glass. The hardened glass can be one or both of a chemically hardened glass and a heat strengthened glass. The hardened glass can have a surface compressive stress of 250 to 1,000 megaPascals (MPa), specifically, 400 to 900 MPa. The hardened glass can have a surface compressive stress of 200 to 400 MPa, specifically, 250 to 350 MPa. The hardened glass can have a depth of layer (DOL) of compressive stress of greater than or equal to 30 micrometers (μηι), specifically, greater than or equal to 60 μηι, more specifically, greater than or equal to 80 μηι, more specifically, greater than or equal to 90 μηι, or greater than or equal to 100 μπι. The depth of layer is measured from the surface of the hardened glass and refers to the depth into the glass that experiences the compressive strength. The hardened glass can have a surface compressive stress of 250 to 350 MPa with a depth of layer of compressive stress of greater than or equal to 40 μπι,

specifically, greater than or equal to 60 μηι.

[0035] The hardened glass can be prepared by placing a glass sheet in a solution comprising a replacement ion and exchanging sodium ions present in the glass sheet with the replacement ion. The glass sheet can comprise sodium oxide plus an oxide of silicon, calcium, aluminum, magnesium, boron, barium, lanthanum, cerium, lead, germanium, or a combination comprising one or more of the foregoing. The glass sheet can comprise sodium oxide plus an oxide of silicon, calcium, aluminum, boron, or a combination comprising one or more of the foregoing. The glass sheet can be, for example, a sodium aluminosilicate or a sodium aluminoborosilicate glass.

[0036] The replacement ion is an ion with a larger atomic radius than sodium, for example, a potassium ion, a rubidium ion, a cesium ion, or a combination comprising one or more of the foregoing. The replacement ion can be present in the solution as sulfates, halides, and the like. The solution can comprise KNO ₃ , specifically, the solution can consist of molten KNO ₃ . The replacing can occur at a temperature of 400 to 500 degrees Celsius (°C). The glass sheet can be in the solution for 4 to 24 hours (hrs), specifically, 6 to 10 hrs.

[0037] The ion exchange process produces: (i) an initial compressive stress at the surface of the hardened glass sheet, (ii) an initial depth of compressive layer into the hardened glass sheet, and (iii) an initial central tension within the hardened glass sheet. The initial compressive stress can be greater than or equal to 500 MPa, specifically, greater than or equal to 600 MPa, more specifically, greater than or equal to 1000 MPa. The initial depth of compressive layer can be less than or equal to 75 μηι. The initial central tension can be greater than a frangibility limit of the glass sheet, for example, greater than or equal to 40 MPa, specifically, greater than or equal to 48 MPa.

[0038] After replacement of the ions, the hardened sheet can be subjected to one or both of an acid etching step and an annealing step. In the annealing step, the hardened glass sheet is subjected to an elevated temperature, for example, of 400 to 500°C. The annealing step can occur in air or in an inert environment. The annealing step can occur for 4 to 24 hrs, specifically, 6 to 10 hrs. The annealing step can reduce the initial compressive stress to a final compressive stress. The annealing step can reduce the initial central tension to a final central tension. The final central tension can be below the frangibility limit of the glass sheet.

[0039] The glass layer can be 0.3 to 1.5 millimeters (mm), specifically, 0.4 to 1.5 mm, more specifically, 0.55 to 0.7 mm or 0.8 to 1 mm. If more than one glass layer is present, each glass layer individually can be greater than or equal to 0.3 mm, specifically, 0.4 to 1.5 mm, specifically, 0.55 to 0.7 mm or 0.8 to 1 mm.

[0040] The glass layer can provide improved resistance to scratching. For example, using a Vicker's indentor on a hardened glass, a load of 3,000 to 7,000 grams is needed to cause damage to the glass. As compared to a standard safety glass, a load of only 1,000 grams is enough to cause damage to the safety glass. The hardened glass can comprise GORILLA

GLASS™ commercially available from Corning Incorporated, New York. The hardened glass can comprise DRAGONTRAIL™ commercially available from Asahi, Japan. The hardened glass can comprise XENSATION™ cover glass commercially available from Schott

Incorporated, Kentucky. [0041] The interlayer can be a layer that adheres the polymer layer and the glass layer to each other. The interlayer can comprise a thermoplastic urethane (TPU), a poly(ethylene-co- vinyl acetate) (EVA), an ionoplast resin composition containing ethylene/methacrylic acid copolymers containing less than or equal to 3 wt% of a metal salt, a silicone, a polyvinyl butyral, or a combination comprising one or both of the foregoing. An example of an ionoplast resin is SENTRYGLAS™ commercially available from DUPPONT™.

[0042] The TPU can comprise long polyol chains that are tied together by shorter hard segments formed by the diisocyanate and chain extenders if present. Polyol chains are typically referred to as soft segments, which impart low-temperature flexibility and room-temperature elastomeric properties. Generally, the higher the soft segment concentration, the lower will be the modulus, tensile strength, hardness, while elongation will increase. Polyols for use as tie- layers in the multilayer article of the present invention can be generally broken into three categories: 1) polyether polyols, 2) polyester polyols, and 3) polyols based on polybutadiene. In one embodiment of the invention, tie-layers comprising polyols having polyether backbones are found to have excellent hydrolytic stability especially desired for automotive applications.

[0043] The interlayer can comprise EVA. The EVA can have a vinyl acetate content of 20 to 80 wt%, specifically, 20 to 50 wt%, more specifically, 25 to 35 wt% based on the total weight of the EVA. The EVA can comprise maleic anhydride functionalized EVA copolymers. The EVA can be free of hindered amine light stabilizers (HALS) so that it will not attack polycarbonate. As used herein, EVA that is free of hindered amine light stabilizers means that the EVA has less than or equal to 0.1 wt%, specifically, 0 to 0.01 wt% of hindered amine light stabilizers based on the total weight of the interlayer.

[0044] Examples of hindered amine light stabilizers that the interlayer can be free of include 4-piperidinol derivative having the general formula (2):

wherein X is oxygen, and Y is hydrogen, hydroxyalkyl, aminoalkyl, or Ci_2o alkyl substituted by both hydroxyl and amino groups. R ⁶ and R ⁷ are each independently selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, or an arylalkyl group. For example, R ⁶ and R ⁷ can each be hydrogen. R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ can each independently be selected from the group consisting of a Ci_6 alkyl group, phenyl, an arylalkyl group, a C5-6 aromatic heterocyclic group, and containing an oxygen, sulfur or nitrogen atom, or R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ respectively, together or with the carbon atom to which they are attached can represent a C ₅ _i ₂ cycloalkyl group. R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ can be methyl.

[0045] Z is an oxy radical, an alkyl group, an alkenyl group, an alkoxyalkyl group, an arylalkyl group that is unsubstituted or which has one or more substituents in its aryl moiety, including, for example, 2,3-epoxypropyl. Z can be represented by the formula

— CH ₂ COOR ¹² , wherein R ¹² is an alkyl group, an alkenyl group, a phenyl group, an aryf alkyl group, or a cyclohexyl group. Z can have the formula— CH ₂ CH(R ¹⁴ )OR ¹³ , wherein R ¹⁴ is a hydrogen atom, a methyl group or a phenyl group and R ¹³ is a hydrogen atom, an alkyl group, an ester, a carbonyl, an acyl group, an aliphatic acyl group, or a group represented by the formula— COOR ¹⁵ , or— OOCR ¹⁵ , wherein R ¹⁵ is an alkyl group, a benzyl group, a phenyl group, and the like.

[0046] Commercially available examples of HALS are TINUVIN™ 622 (Ciba Specialty Chemicals, Inc., Basel Switzerland), TINUVIN™770 (Ciba Specialty Chemicals, Inc., Basel Switzerland), CYASORB™ UV-3529 (Cytec), CYASORB™ UV-3631 (Cytec) CYASORB™ UV-3346 (Cytec), CYASORB™ UV-4593 (Cytec), UVINUL™ 5050H (BASF), and

SANDUVOR™ 3058 (Clariant).

[0047] The interlayer can be 0.2 to 1.4 mm, specifically, 0.2 to 0.7 mm, specifically, 0.3 to 0.6 mm, more specifically, 0.35 to 0.5 mm.

[0048] The polymer layer comprises a polymer composition that can comprise a polysiloxane, a polyester (such as polyethylene terephthalate), a nylon, an aliphatic polyamide, a semi-aromatic polyamide, a polycarbonate, an acrylic (for example, a solvent cast acrylic), an acrylonitrile butylstyrene, a polybutylterephthalate, a polyetherimide, a poly(ether ether ketone), a poly(l,4-cyclohexane-dimethanol-l,4-cyclohexanedicarboxylate ), or a composition comprising one or more of the foregoing. The polymer composition can comprise a polysiloxane, a polyester, a polycarbonate, a copolymer comprising one or more of the foregoing, or a combination comprising one or more of the foregoing. The polymer layer can comprise two or more polymer layers that are 0.1 to 15 mm thick, wherein each layer independently comprises a polymer composition, and wherein an interlayer can be located in between the respective polymer layers.

[0049] The polymer layer can comprise a polycarbonate. The polycarbonate can be polymerized by in an interfacial process. Although the reaction conditions for interfacial polymerization can vary, an exemplary process generally involves dissolving or dispersing a dihydric phenol reactant in an aqueous base, adding the resulting mixture to a water-immiscible solvent medium, and contacting the reactants with a carbonate precursor in the presence of a catalyst such as, for example, triethylamine or a phase transfer catalyst, under controlled pH conditions, e.g., 8 to 11. The water immiscible solvent can include one or more of methylene chloride, 1,2-dichloroethane, chlorobenzene, toluene, and the like. Generally, a chelant, such as an iron scavenger, can be used as well to remove impurities and contaminants. The methylene chloride can contain less than 10 ppm of calcium, less than 1 ppm of iron, less than 0.5% salt, and/or less than 0.1% degraded polymer.

[0050] Exemplary carbonate precursors include, for example, a carbonyl halide such as carbonyl bromide or carbonyl chloride, or a haloformate such as a bishaloformates of a dihydric phenol (e.g., the bischloroformates of bisphenol-A and hydroquinone) or a glycol (e.g., the bishaloformate of ethylene glycol, neopentyl glycol, and polyethylene glycol). Among the phase transfer catalysts that can be used are catalysts of the formula (R3) ₄ Q+X, wherein each R ₃ is the same or different, and is a Ci_io alkyl group; Q is a nitrogen or phosphorus atom; and X is a halogen atom or a Ci _-8 alkoxy group or C ₆ -i8 aryloxy group. Exemplary phase transfer catalysts include, for example, [CH ₃ (CH ₂ ) ₃ ] ₄ NX, [CH ₃ (CH ₂ ) ₃ ] ₄ PX, [CH ₃ (CH ₂ ) ₅ ] ₄ NX, [CH ₃ (CH ₂ )6] ₄ NX, [CH ₃ (CH ₂ ) ₄ ] ₄ NX, CH ₃ [CH ₃ (CH ₂ ) ₃ ] ₃ NX, and CH ₃ [CH ₃ (CH ₂ ) ₂ ] ₃ NX, wherein X is CI ^" , Br ^" , a C _1-8 alkoxy group or a C ₆ -i8 aryloxy group. An effective amount of a phase transfer catalyst can be 0.1 to 10 wt% based on the weight of bisphenol in the phosgenation mixture.

[0051] The BPA used as a polymer precursor polycarbonate grade BPA that is a high purity BPA with an APHA of less than 10. The BPA can have a purity of greater than or equal to 99.65%, specifically, greater than or equal to 99.80%. The organic purity can be defined as 100 wt% minus the sum of known and unknown impurities detected using ultraviolet radiation. The BPA can have a sulfur level of less than or equal to 4 parts per million by weight (ppm) as measured by a commercially available Total Sulfur Analysis based on combustion and coulometric detection.

[0052] The aqueous base can be aqueous sodium hydroxide (NaOH). NaOH can be used to maintain the reaction pH within a range of 9.5 to 10.0, and to neutralize the HC1 formed from the reaction of BPA with phosgene. The NaOH used in the present disclosure can contain less than 10 ppm of NaC10 ₃ . Additionally, solid particulates can be removed from the NaOH solution by filtration using 10 micron absolute media.

[0053] High quality phosgene can be used in the polymerization of the polycarbonate. Phosgene can be produced by the reaction of carbon monoxide and chlorine and the level of incorporated chlorine atoms in the polycarbonate resin can be less than 20 ppm when phosgene containing less than 100 ppm free chlorine is used.

[0054] The Mw of the polycarbonate powder can be controlled by adding a chain stopping or endcapping agent. Exemplary endcapping agents include phenol, para-t-butylphenol, and p-cumyl phenol (PCP). The amount of endcapping agent can be 2.25 to 5.5 mole% and can result in a Mw of 36,000 to 17,000 grams per mole (g/mol) as determined by gel permeation chromatography (GPC) using polycarbonate standards. More commonly, the amount of endcapping agent can be 2.9 to 4.3 mole percent (mol%) and can result in a Mw of 30,000 to 21,000 g/mol. An endcapping agent can be employed in the reaction such that the resultant composition comprising polycarbonate comprises a free hydroxyl level less than or equal to 150 ppm, more specifically, of 25 to 150 ppm, or 30 to 100 ppm.

[0055] The post reaction processing of the polycarbonate can be important in producing a low color and color stable polycarbonate resin. The reaction mixture, containing polycarbonate, brine, water immiscible solvent, and impurities, can be considered to be a batch. The batch can be discharged and purified through a series of purifying stages. Each stage can be made up, for example, of one or more liquid-liquid centrifuges.

[0056] In a first purifying stage, the brine phase can be separated from the methylene chloride phase that contains dissolved polycarbonate. In a second purifying stage, the catalyst can be extracted from the methylene chloride phase. This can be done using dilute aqueous hydrochloric acid. In a third purifying stage, residual ionic species can be removed by washing the methylene chloride phase using high quality water. High quality water has generally been condensed from steam or has been purified using de-ionization, such that few contaminants are present in the water. For example, the conductivity of the high quality water can be less than 10 micro-siemens per centimeter (micro-siemens/cm).

[0057] After purification, the non-aqueous phase containing the dissolved polycarbonate can be optionally filtered using 1 to 10 μηι absolute filters. The polycarbonate can then be concentrated and isolated by means of steam precipitation, which instantly flashes the dichloromethane solvent during direct contact with steam. The steam used for precipitation can be very low in mineral and ion content, preferably with a conductivity value of less than one micro-siemens/cm. The steam used for isolation, can optionally be filtered using 1 to 50 μηι absolute filters. Precipitation of resin using steam with high mineral or ion content (greater than 10 micro-siemens/cm) can result in high yellowness and poor melt stability for the polycarbonate resin.

[0058] Residual dichloromethane can be removed from the wet polycarbonate in a plug flow column using counter current steam flow. Residual water can be removed from the wet polycarbonate in a fluid bed dryer using heated air. The resulting polycarbonate powder can then be collected and optionally compounded.

[0059] The compounding of the polycarbonate powder can be performed in an extruder. An extruder can be used for compounding, molding, pelletization or forming films, sheets or profiles. Such extruders typically have a heated extrusion barrel and one or two screws revolving within the barrel to compress, melt, and extrude the polycarbonate through an orifice in an extrusion nozzle. The barrel can be divided into several different zones, such as feed, transition, mixing, dispersion, and metering zones.

[0060] The polycarbonate, along with additives, can be melt extruded at a controlled temperature. 58 mm or 70 mm extruders can be typically used for high-grade polycarbonate resins. The polycarbonate can be melt filtered through a 30 μηι filter stack to reduce particulate contamination. It is possible to use a smaller mesh filter (10 μιη) to further improve the quality of the product. Stainless steel water baths with 0.5 μm-filtered water can be used to minimize contamination. Polycarbonate resin exiting the extruder can be pelletized and collected in packaging such as bulk boxes or super sacks. Care can be taken during the extrusion and packaging processes to exclude particulates that can be present in air and water transfer systems.

[0061] "Polycarbonate" as used herein means a polymer or copolymer having repeating structural carbonate units of the formula -R ¹ -0-(C=0)-0-, wherein at least 60 percent of the total number of R ¹ groups are aromatic, or each R ¹ contains at least one C ₆ -3o aromatic group. Polycarbonates and their methods of manufacture are known in the art, being described, for example, in WO 2013/175448 Al, US 2014/0295363, and WO 2014/072923. Polycarbonates are generally manufactured from bisphenol compounds such as 2,2-bis(4-hydroxyphenyl) propane ("bisphenol-A" or "BPA"), 3,3-bis(4-hydroxyphenyl) phthalimidine, l,l-bis(4-hydroxy-3- methylphenyl)cyclohexane, or l,l-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane , or a combination comprising at least one of the foregoing bisphenol compounds can also be used. The polycarbonate can be a homopolymer derived from BPA; a copolymer derived from BPA and another bisphenol or dihydroxy aromatic compound such as resorcinol; or a copolymer derived from BPA and optionally another bisphenol or dihydroxyaromatic compound, and further comprising non-carbonate units, for example aromatic ester units such as resorcinol terephthalate or isophthalate, aromatic-aliphatic ester units based on C ₆ -2o aliphatic diacids, polysiloxane units such as polydimethylsiloxane units, or a combination comprising at least one of the foregoing.

[0062] Branched polycarbonate blocks can be prepared by adding a branching agent during polymerization. These branching agents include polyfunctional organic compounds containing at least three functional groups selected from hydroxyl, carboxyl, carboxylic anhydride, haloformyl, and mixtures of the foregoing functional groups. Specific examples include trimellitic acid, trimellitic anhydride, trimellitic trichloride (TMTC), tris-p-hydroxy phenyl ethane (THPE), 3,3-bis-(4-hydroxyphenyl)-oxindole (also known as isatin-bis-phenol), tris-phenol TC (l,3,5-tris((p-hydroxyphenyl)isopropyl)benzene), tris-phenol PA (4(4(1, l-bis(p- hydroxyphenyl)-ethyl) alpha, alpha-dimethyl benzyl)phenol), 4-chloroformyl phthalic anhydride, trimesic acid, and benzophenone tetracarboxylic acid. The branching agents can be added at a level of 0.05 to 2.0 wt%. Mixtures comprising linear polycarbonates and branched polycarbonates can be used.

[0063] Various types of end-capping agents can be utilized for embodiments

encompassed by this disclosure. The end-capping agent can be selected based upon the molecular weight of said polycarbonate and said branching level imparted by said branching agent. The end-capping agents can be selected from at least one of the following: phenol or a phenol containing one or more substitutions with at least one of the following: aliphatic groups, olefinic groups, aromatic groups, halogens, ester groups, and ether groups. The end-capping agents can be selected from at least one of the following: phenol, para-t-butylphenol or para- cumylphenol.

[0064] The polycarbonate encompassed by this disclosure can exclude the utilization of a melt polymerization process to make at least one of said polycarbonates.

[0065] The polymer composition can comprise a polyester. The polyester contains repeating units of formula (10): -(C=0)-T-(C=0)-D-0- wherein D is a divalent group derived from a dihydroxy compound, and can be, for example, a C _2- io alkylene group, a C ₆ -2o alicyclic group, a C ₆ -2o aromatic group or a polyoxyalkylene group in which the alkylene groups contain 2 to 6 carbon atoms, specifically, 2, 3, or 4 carbon atoms; and T is a divalent group derived from a dicarboxylic acid, and can be, for example, a C _2- io alkylene group, a C ₆ -2o alicyclic group, a C ₆ -2o alkyl aromatic group, or a C ₆ -2o aromatic group.

[0066] The polyester can comprise arylate ester units of the arylate-containing units and are derived from the reaction product of one equivalent of an isophthalic acid derivative and/or terephthalic acid derivative. Exemplary arylate ester units are aromatic polyester units such as isophthalate-terephthalate-resorcinol ester units, isophthalate-terephthalate-bisphenol ester units, or a combination comprising each of these. Specific arylate ester units include poly(isophthalate- terephthalate-resorcinol) esters, poly(isophthalate-terephthalate-bisphenol-A) esters ,

poly[(isophthalate-terephthalate-resorcinol) ester-co-(isophthalate -terephthalate -bisphenol- A)] ester, or a combination comprising at least one of these. A polyester copolymer can comprise poly(l,4-cyclohexanedimethylene terephthalate)-co-poly(ethylene terephthalate), abbreviated as PETG where the polymer comprises greater than or equal to 50 mole% of poly(ethylene terephthalate), and abbreviated as PCTG where the polymer comprises greater than 50 mole% of poly(l,4-cyclohexanedimethylene terephthalate). The polyester can comprise a poly(alkylene cyclohexanedicarboxylate). Of these, a specific example is poly(l,4-cyclohexane-dimethanol- 1 ,4-cyclohexanedicarboxylate) (PCCD). [0067] The polymer composition can comprise a polysiloxane or a polycarbonate- polysiloxane copolymer. The polysiloxane (also referred to herein as "polydiorganosiloxane") has repeat units of formula (11)

wherein each occurrence of R is same or different, and is a Ci-13 monovalent organic group. For example, each R can independently be a Ci-13 alkyl group, Ci-13 alkoxy group, C2-13 alkenyl group, C2-13 alkenyloxy group, C ₃ _ ₆ cycloalkyl group, C ₃ _ ₆ cycloalkoxy group, C ₆ -i4 aryl group, C ₆ - 10 aryloxy group, C7-13 arylalkyl group, C7-13 arylalkoxy group, C7-13 alkylaryl group, or C7-13 alkylaryloxy group. The foregoing groups can be fully or partially halogenated with fluorine, chlorine, bromine, or iodine, or a combination thereof. Combinations of the foregoing R groups can be used in the same copolymer. In an embodiment, the polysiloxane comprises R groups can have a minimum hydrocarbon content. E can have an average value of 2 to 1,000.

[0068] The polymer composition can comprise one or more copolymers. Examples of copolymers include polycarbonate-polyesters, polycarbonate -polysiloxanes, polyester- polysiloxanes, and polycarbonate-polyester-polysiloxanes.

[0069] The polycarbonate-polysiloxane copolymer can be a polycarbonate that is end group functionalized with polysiloxane repeat units. The polysiloxane end groups can have less than or equal to 15 siloxane units. The polycarbonate-polysiloxane copolymer can comprise 1 to 60 mol%, specifically, 3 to 50 mol% of polydiorganosiloxane blocks relative to the moles of polycarbonate blocks. The polysiloxane copolymer can comprise ester repeat units (such as isophthalate-terephthalate-resorcinol ester repeat units), carbonate units (such as bisphenol A repeat units), or a combination comprising one or both of the foregoing. The polysiloxane copolymer can comprise an arylate containing unit, for example, in a polyester and/or in a polycarbonate repeat unit. The arylate-containing polysiloxane copolymer can comprise of 50 to 99 mol% of arylate ester units, specifically, 58 to 90 mol% arylate ester units; 0 to 50 mol% aromatic carbonate units (e.g., resorcinol carbonate units, bisphenol carbonate units, and other carbonate units such as aliphatic carbonate units) based on the total moles of repeat units in the polysiloxane copolymer.

[0070] The polymer composition can comprise a polysiloxane -polycarbonate copolymer and a brominated polycarbonate. For example, the polymer composition can comprise greater than or equal to 5 wt%, specifically, 5 to 80 wt% of a poly(siloxane-co-carbonate); greater than or equal to 20 wt%, specifically, 20 to 95 wt% of a brominated polycarbonate (for example, a brominated polycarbonate derived from 2,2',6,6'-tetrabromo-4,4'-isopropylidenediphenol (2,2- bis(3,5-dibromo-4-hydroxyphenyl)propane (TBBPA) and carbonate units derived from at least one dihydroxy aromatic compound that is not TBBPA ("TBBPA copolymer")); and optionally a polycarbonate that is different from the poly(siloxane-co-carbonate) and the TBBPA copolymer. The third polycarbonate can be present in an amount of 8 to 12 wt% based on the total weight of the poly(siloxane -co-carbonate), TBBPA copolymer, and optional third polycarbonate.

[0071] The polymer composition can comprise a polysiloxane -polycarbonate copolymer and a brominated oligomer. The polymer composition can comprise greater than or equal to 5 wt%, specifically, 5 to 80 wt% of a poly(siloxane -co-carbonate); greater than or equal to 20 wt%, specifically, 20 to 95 wt% of a brominated oligomer; and optionally a polycarbonate that is different from the poly(siloxane -co-carbonate) and the brominated oligomer. The polymer composition can comprise greater than or equal to 0.3 wt% of siloxane and greater than or equal to 7.8 wt% of bromine based on the total weight of the poly(siloxane-co-carbonate), the brominated oligomer, and optional third polycarbonate. The third polycarbonate can be present in an amount of 8 to 12 wt% based on the total weight of the poly(siloxane-co-carbonate), the brominated oligomer, and optional third polycarbonate. The brominated oligomer can have a weight average molecular weight (Mw) of 1,000 to 10,000 g/mol based on polycarbonate standards.

[0072] The polymer layer can be 0.1 to 15 mm, or 2 to 13 mm, or 2 to 12 mm.

[0073] The polymer layer can comprise one or both of a heat stabilizer (for example a phosphite heat stabilizer) and a flame retardant. Flame retardants include organic compounds that include phosphorus, bromine, and/or chlorine. Non-brominated and non-chlorinated phosphorus-containing flame retardants can be preferred in certain applications for regulatory reasons, for example, organic phosphates and organic compounds containing phosphorus- nitrogen bonds. The polymer layer can comprise a flame retardant comprising a brominated polycarbonate, for example, a brominated bisphenol A polycarbonate. The brominated polycarbonate can be present in an amount of 1 to 10 wt%, specifically, 2 to 7 wt% based on the total weight of the polymer composition.

[0074] One type of organic phosphate is an aromatic phosphate of the formula

(GO)3P=0, wherein each G is independently an alkyl, cycloalkyl, aryl, alkylaryl, or aralkyl group, provided that at least one G is an aromatic group. Two of the G groups can be joined together to provide a cyclic group, for example, diphenyl pentaerythritol diphosphate. Aromatic phosphates include, phenyl bis(dodecyl) phosphate, phenyl bis(neopentyl) phosphate, phenyl bis(3,5,5'-trimethylhexyl) phosphate, ethyl diphenyl phosphate, 2-ethylhexyl di(p-tolyl) phosphate, bis(2-ethylhexyl) p-tolyl phosphate, tritolyl phosphate, bis(2-ethylhexyl) phenyl phosphate, tri(nonylphenyl) phosphate, bis(dodecyl) p-tolyl phosphate, dibutyl phenyl phosphate, 2-chloroethyl diphenyl phosphate, p-tolyl bis(2,5,5'-trimethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate, or the like. A specific aromatic phosphate is one in which each G is aromatic, for example, triphenyl phosphate, tricresyl phosphate, isopropylated triphenyl phosphate, and the like.

[0075] Di- or polyfunctional aromatic phosphorus-containing compounds are illustrated in the formulas below:

wherein each G ¹ is independently a hydrocarbon having 1 to 30 carbon atoms; each G ² is independently a hydrocarbon or hydrocarbonoxy having 1 to 30 carbon atoms; each X is independently a bromine or chlorine; m is 0 to 4, and n is 1 to 30. Di- or polyfunctional aromatic phosphorus-containing compounds of this type include resorcinol tetraphenyl diphosphate (RDP), the bis(diphenyl) phosphate of hydroquinone and the bis(diphenyl) phosphate of bisphenol A, their oligomeric and polymeric counterparts, and the like.

[0076] Flame retardant compounds containing phosphorus-nitrogen bonds include phosphonitrilic chloride, phosphorus ester amides, phosphoric acid amides, phosphonic acid amides, phosphinic acid amides, and tris(aziridinyl) phosphine oxide. Specific examples include phosphoramides of the formula (i) wherein each A moiety is a 2,6-dimethylphenyl moiety or a 2,4,6-trimethylphenyl moiety.

[0077] Other flame retardant compounds containing phosphorus-nitrogen bonds include phosphazenes. Specific examples include phosphazenes of the formula (ii), where X is -O- Phenyl, alkyl-phenyl, dialkylphenyl or trialkyl phenyl. An illustrative example of the

phosphazenes includes SPB-100 from Otsuka Chemical Co., Ltd., where X is phenyl.

[0078] When used, phosphorus-containing flame retardants can be present in amounts of 0.1 to 30 parts by weight, specifically, 1 to 20 parts by weight, based on 100 parts by weight of the total composition, excluding any filler.

[0079] Halogenated materials can also be used as flame retardants, for example, 2,2-bis- (3,5-dichlorophenyl)-propane; bis-(2-chlorophenyl)-methane; bis(2,6-dibromophenyl)-methane; 1 , 1 -bis-(4-iodophenyl)-ethane; 1 ,2-bis-(2,6-dichlorophenyl)-ethane; 1 , 1 -bis-(2-chloro-4- iodophenyl)ethane; l,l-bis-(2-chloro-4-methylphenyl)-ethane; l,l-bis-(3,5-dichloro phenyl)- ethane; 2,2-bis-(3-phenyl-4-bromophenyl)-ethane; 2,6-bis-(4,6-dichloro naphthyl)-propane; 2,2- bis-(2,6-dichlorophenyl)-pentane; 2,2-bis-(3,5-dibromo phenyl)-hexane; bis-(4-chlorophenyl)- phenyl-methane; bis-(3,5-dichlorophenyl)-cyclohexylmethane; bis-(3-nitro-4-bromophenyl)- methane; bis-(4-hydroxy-2,6-dichloro-3-methoxyphenyl)-methane; and 2,2-bis-(3,5-dichloro-4- hydroxyphenyl)-propane 2,2 bis-(3-bromo-4-hydroxyphenyl)-propane. Also included within the above structural formula are: 1,3-dichlorobenzene, 1,4-dibromo benzene, l,3-dichloro-4- hydroxybenzene, and biphenyls such as 2,2'-dichloro biphenyl, polybrominated 1 ,4- diphenoxybenzene, 2,4'-dibromobiphenyl, and 2,4'-dichloro biphenyl as well as decabromo diphenyl oxide, and the like.

[0080] Also useful are oligomeric and polymeric halogenated aromatic compounds, such as a copolycarbonate of bisphenol A and tetrabromobisphenol A and a carbonate precursor, e.g., phosgene. Metal synergists, e.g., antimony oxide, can also be used with the flame retardant. When present, the halogen containing flame retardant can be present in an amount of 1 to 25 parts by weight, specifically, 2 to 20 parts by weight, based on 100 parts by weight of the total composition, excluding any filler.

[0081] The polymer composition can be essentially free of chlorine and bromine.

Essentially free of chlorine and bromine refers to materials produced without the intentional addition of chlorine or bromine or chlorine or bromine containing materials. Essentially free of bromine and chlorine can be defined as having a bromine and/or chlorine content of less than or equal to 100 ppm, less than or equal to 75 ppm, or less than or equal to 50 ppm based on the total weight of the composition, excluding any filler.

[0082] Inorganic flame retardants can also be used, for example, salts of C2-16 alkyl sulfonates such as potassium perfluorobutane sulfonate (Rimar salt), potassium perfluoroctane sulfonate, and tetraethylammonium perfluorohexane sulfonate, salts of aromatic sulfonates such as sodium benzene sulfonate, sodium toluene sulfonate (NATS), and the like, salts of aromatic sulfone sulfonates such as potassium diphenylsulfone sulfonate (KSS), and the like; salts formed by reacting for example, an alkali metal or alkaline earth metal (e.g., lithium, sodium, potassium, magnesium, calcium and barium salts) and an inorganic acid complex salt, for example, an oxo- anion (e.g., alkali metal and alkaline-earth metal salts of carbonic acid, such as Na ₂ C(¾, K2CO ₃ , MgC03, CaCC>3, and BaCC>3, or a fluoro-anion complex such as Li ₃ AlF ₆ , BaSiF ₆ , KBF4, K ₃ AIF ₆ , KAIF4, K ₂ SiF ₆ , and/or Na ₃ AlF ₆ or the like. Rimar salt and KSS and NATS, alone or in combination with other flame retardants, are particularly useful. When present, inorganic flame retardant salts are generally present in amounts of 0.01 to 10 parts by weight, more specifically, 0.02 to 1 parts by weight, based on 100 parts by weight of polycarbonate and impact modifier. The perfluoroalkyl sulfonate salt can be present in an amount of 0.30 to 1.00 wt%, specifically, 0.40 to 0.80 wt%, more specifically, 0.45 to 0.70 wt%, based on the total weight of the polymer composition. The aromatic sulfonate salt can be present in the final polymer composition in an amount of 0.01 to 0.1 wt%, specifically, 0.02 to 0.06 wt%, and more specifically, 0.03 to 0.05 wt%. Exemplary amounts of aromatic sulfone sulfonate salt can be 0.01 to 0.6 wt%, specifically, 0.1 to 0.4 wt%, and more specifically, 0.25 to 0.35 wt%, based on the total weight of the polymer composition.

[0083] Anti-drip agents can also be used in the composition, for example, a fibril forming or non-fibril forming fluoropolymer such as polytetrafluoroethylene (PTFE). The anti-drip agent can be encapsulated by a rigid copolymer, for example, styrene-acrylonitrile copolymer (SAN). PTFE encapsulated in SAN is known as TSAN. TSAN can comprise 50 wt% PTFE and 50 wt% SAN, based on the total weight of the encapsulated fluoropolymer. The SAN can comprise, for example, 75 wt% styrene and 25 wt% acrylonitrile based on the total weight of the copolymer. An antidrip agent can be present in an amount of 0.1 to 10 percent by weight, based on 100 percent by weight of polycarbonate and impact modifier.

[0084] The flame retardant can comprise organophosphorus compound in an amount effective to provide 0.1 to 1.0 wt%, specifically, 0.3 to 0.8 wt% of phosphorus, based on the total weight of the polymer composition. The organophosphorus compound can comprise an aromatic organophosphorus compound having at least one organic aromatic group and at least one phosphorus-containing group, an organic compound having at least one phosphorus-nitrogen bond, or a combination comprising one or more of the foregoing. The aromatic

organophosphorus compound can comprise a C3-30 aromatic group and a phosphate group, phosphite group, phosphonate group, phosphinate group, phosphine oxide group, phosphine group, phosphazene, or a combination comprising at least one of the foregoing phosphorus- containing groups.

[0085] The flame retardant can comprise an organophosphite, (such as triphenyl phosphite, tris-(2,6-dimethylphenyl)phosphite and tris-(mixed mono-and di-nonylphenyl)), a phosphonate (such as dimethylbenzene phosphonate), a phosphate (such as trimethyl phosphate), or a combination comprising one or more of the foregoing, for example in an amount of 0.01 to 5 wt%, based on the total weight of polymer composition. The polymer can comprise tris(2,4-di-t- butylphenyl) phosphate available as IRGAPHOS™ 168.

[0086] The aromatic organophosphorus compound can comprise a compound of the formula

wherein R , R , R and R are each independently Ci _-8 alkyl, C ₅ _ ₆ cycloalkyl, C ₆ -2o aryl _> or C ₇ _ 12 arylalkylene, each optionally substituted by Ci_i ₂ alkyl, and X is a mono- or poly-nuclear aromatic C ₆ -3o moiety or a linear or branched C2-30 aliphatic radical, which can be OH-substituted and can contain up to 8 ether bonds, provided that at least one of R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , and X is aromatic; n is each independently 0 or 1, and q is 0.5 to 30. The aromatic organophosphorus compound can comprise bisphenol A bis(diphenyl phosphate), triphenyl phosphate, resorcinol bis(diphenyl phosphate), tricresyl phosphate, or a combination comprising at least one of the foregoing.

[0087] The polymer layer can comprise a phosphorous flame retardant such as

FYROLFLEX™ Sol-DP commercially available from ICL Industrial Products. The

phosphorous flame retardant can be present in an amount of 1 to 20 wt%, specifically 5 to 10 wt% based on the total weight of the polymer composition.

[0088] The polymer layer can comprise a colorant such as one or both of a pigment and a dye. The polymer layer can comprise, for example, one or both of solvent violet 36 and pigment blue 60.

[0089] As illustrated in FIG. 7, the multilayer article can be prepared by (I) preparing a multilayer stack comprising a first hardened glass layer, a first polymer layer, and a first interlayer located in between the first hardened glass layer and the first polymer layer; (II) deforming the multilayer stack to form a multilayer stack; (III) increasing a temperature of the multilayer stack from a first temperature to a second temperature to the multilayer stack and increasing a pressure exerted on the multilayer stack from a first pressure to a second pressure; and (IV) reducing the second temperature to a reduced temperature and reducing the second pressure to a reduced pressure to form the multilayer article. During this process the interlayer material softens such that it forms a bond between the glass and polymer layer.

[0090] The first temperature can be 15 to 25°C. The second temperature can be greater than or equal to 35°C, or 35 to 150°C, or greater than or equal to 70°C. The second temperature can be maintained for 3 minutes, or 3 to 20 minutes, or greater than or equal to 3 min prior to increasing the pressure. The second temperature can be increased to a third temperature, for example, after increasing the pressure. The third temperature can be the curing temperature of the interlayer material and can be greater than or equal to 100°C, or greater than or equal to 120°C, or more specifically greater than or equal to 130°C, or 130 to 145°C. The third temperature can be maintained for greater than or equal to 10 min, or more specifically greater than or equal to 30 minutes, or greater than or equal to 3.5 hrs.

[0091] The first pressure can be a vacuum pressure, for example, of -0.08 to -0.09 MPa. The first pressure can be maintained throughout the cycle until it is reduced when the temperature reaches the reduced temperature. The second pressure can be a volumetric pressure, for example, of 0.05 to 0.2 MPa, or 0.05 to 0.21 MPa. The second pressure can be maintained until the pressure is reduced. The second pressure can be greater than or equal to 0.03 MPa, specifically, 0.1 to 1 MPa. The second pressure can be increased to a third pressure. The third pressure can be greater than or equal to 0.2 MPa or more specifically greater than or equal to 0.25 MPa. The third pressure can be maintained until the pressure is reduced.

[0092] The reduced temperature can be less than or equal to 60°C. The reduced pressure can be less than or equal to 0.0005 MPa.

[0093] The article can retain its curvature. For example, retaining curvature can refer to the formed multilayer article with an article radius associated with a curvature, wherein the article radius is within 5%, specifically, within 1% of the imparted radius associated with an imparted curvature, for example, of a mold radius. The article can have a radius of curvature, R, without breaking of less than or equal to 50 cm, specifically, less than or equal to 20 centimeters, more specifically, less than or equal to 10 cm, more specifically, less than or equal to 5 cm. The article can have a R without breaking of greater than or equal to 0.5 cm, specifically, greater than or equal to 1 centimeters, more specifically, greater than or equal to 5 cm, more specifically, greater than or equal to 20 cm. The curvature can change along a length of the article. For example, the radius of curvature can increase or decrease along a length of the article. The multilayer article can comprise a local region of curvature and a flat section in an x-y plane, for example, as is illustrated in FIG. 5. The curvature can invert along a length of the article, for example, the curvature can change from convex to concave. For example, FIG. 6 illustrates a multilayer article comprising a concave portion and two convex portions. It is noted that the concave portion comprises a bend with a local radius of curvature. The article can comprise a curvature in one or more planes. For example, in an x-y and a y-z plane to form at least a portion of a spherical or ovoidal shape.

[0094] The multilayer stack can be prepared by placing an interlayer on one of a polymer layer or a glass layer and adding the other of the polymer layer and the glass layer. The multilayer stack can be prepared by layering a first interlayer on top of a first glass layer, placing a polymer layer onto the first interlayer, placing a second interlayer onto the polymer layer, and finally placing a second glass layer onto the second interlayer. A multilayer stack of the multilayer article can be prepared similarly by placing a first interlayer on top of a first glass layer, then placing a polymer layer onto the first interlayer.

[0095] The forming process can be performed by a variety of processes such as autoclave lamination, vacuum lamination (such as vacuum bag lamination), and/or parallel plate lamination.

[0096] The multilayer article can be formed by preparing a multilayer stack comprising a hardened glass layer, a polymer layer, and an interlayer located in between the glass layer and the polymer layer; placing the multilayer stack into a mold with a curved shape (referred to as a curved mold); and applying a vacuum by means of a vacuum bag or bladder that holds the multilayer stack into the curved mold shape and increasing a temperature of the multilayer stack in the mold so that the interlayer cures the multilayer stack to form the multilayer article having an area with a curvature. An additional pressure can be exerted on the mold during the forming. Upon removal of the multilayer stack from the mold, the multilayer stack surprisingly maintains the curvature of the mold and does not exhibit any spring back from the stress created by deforming (e.g., curving) the glass. Also, surprisingly, the hardened glass did not break after undergoing the vacuum bagging lamination process described which created a curvature that induced stress on the glass.

[0097] A method of making a multilayer article can comprise preparing a multilayer stack and deforming the multilayer stack. The multilayer stack can be vacuum bagged and a vacuum can be applied. The temperature of the multilayer stack can be increased from a first temperature to a second temperature. For example, the first temperature can be 15 to 25 °C and the second temperature can be 38 to 150°C. The second temperature can be maintained for greater than or equal to 3 min, more specifically, greater than or equal to 15 min, and more specifically, greater than or equal to 30 min. A pressure can be applied to the multilayer stack. The pressure exerted on the multilayer stack can be increased from a first pressure to a second pressure. The first pressure can be less than or equal to 1 atmosphere (atm) (i.e. less than or equal to 0.1 MPa). The second pressure can be greater than equal to 0.03 MPa, or greater than equal to 0.1 MPa and more specifically, greater than or equal 0.15 MPa, or greater than equal to 0.2 MPa, or greater than or equal to 0.4 MPa, or 0.1 to 1 MPa. The second pressure can be maintained for greater than or equal to 20 min. The temperature of the multilayer stack can be increased from the second temperature to a third temperature of greater than or equal to 120°C or greater than or equal 130°C, or 130 to 145°C after applying the vacuum or increasing the pressure. The third temperature can be maintained for greater than or equal to 10 min, or greater than or equal to 20 min, or greater than or equal to 30 min. The temperature can be decreased, for example, to a fourth temperature of less than or equal to 60°C and the pressure can be removed to form the multilayered article. [0098] The multilayer article can be formed by deforming the multilayer stack, for example, by placing the multilayer stack on a tool with a radius of curvature, for example, of 492 mm in the length direction. The multilayer stack can then be pressed onto the tool so that the multilayer stack takes the shape of the curvature. The multilayer stack can be vacuum bagged onto the curved mold to maintain the desired curvature. The multilayer stack can be placed into an autoclave. The temperature of the autoclave can be increased from a first temperature of 15 to 25°C to a second temperature of 35 to 150°C, for example, 48 to 145°C. The rate of increase of the autoclave temperature can be 1 to 3 degrees Celsius per minute (°C/min), for example, 1.4 to 2°C/min. The autoclave can be held at this second increased temperature for greater than or equal to 3 min, for example, 3 to 40 min, for example, 15 to 30 min. The holding of the second temperature is called a soak. The pressure exerted on the multilayer stack can be increased from a first pressure to a second pressure. The first pressure can be less than or equal to 1 atmosphere. The first pressure can be a vacuum pressure of -0.1 to -0.05 MPa. The pressure in the autoclave can then be increased to greater than or equal to 0.3 megaPascal (MPa), for example, 0.35 to 1.4 MPa or greater, and more specifically, 0.4 to 0.827 MPa or greater. The autoclave can be held at the increased pressure for greater than or equal to 20 min, for example, 20 to 50 min, for example, 30 to 40 min. The temperature in the autoclave can be gradually increased to greater than or equal to 120°C, for example, 125 to 150°C, for example, to 132 to 145°C, over a time of 30 min to 1.5 hr, for example, 45 to 55 min. The temperature can then be held at this temperature for greater than or equal to 10 min, for example, 10 to 60 min, for example, 10 to 30 min. The autoclave can then be cooled at -1 to -5°C/min, for example, -2 to -3°C/min. The autoclave can be cooled to less than or equal to 60°C, for example, 37 to 55°C, for example, 46 to 52°C where the pressure in the autoclave can then be released. The autoclave can then be opened and the multilayer article can then be allowed to return to room temperature.

[0099] The multilayer article can be prepared by placing the multilayer stack in a tool with a curvature (referred to herein as a curved tool) in a vacuum laminator. The multilayer stack can be placed in a vacuum laminator at room temperature, for example, 15 to 25°C, and a vacuum can be applied, for example, at a pressure of 0 to 0.11 MPa. The vacuum can be applied for greater than or equal to 10 min, for example, 10 to 20 min, for example, 12 to 17 min. The temperature can then be increased to greater than or equal to 50°C, for example, 60 to 100°C, for example, 85 to 95°C at l°C/min while a pressure of 0.2 to 1 MPa is added to the vacuum pressure. The multilayer stack can be held at this temperature and pressure for greater than or equal to 15 minutes, or greater than or equal to 1.5 hrs, for example, 2 to 6 hrs, for example, 3 to 5 hrs. The temperature can then be increased to a third temperature of greater than or equal to 100°C, for example, 100 to 125°C, for example, at a rate of 0.5 to 2.5°C/min. The multilayer stack can be held at this increased temperature for greater than or equal to 3.5 hrs, for example, 4 to 7 hrs, for example, 5 to 6 hrs. The vacuum and the pressure can then be released and the sample temperature can return to room temperature before removing from the vacuum laminator. The polymer layer can be dried in an oven for 1 to 14 hrs at the glass transition temperature of the polymer prior to lamination, specifically, 250°F (121 °C) for PC.

[0100] The multilayer article can be prepared by placing the multilayer stack in a curved tool in a vacuum bag or vacuum bladder frame and then placing everything in an air circulating oven. After drying any hydroscopic materials, the multilayer stack can be held in the curved shape of a tool using a vacuum bag or vacuum bladder at a pressure of 0 to 0.11 MPa and can be placed in an oven at room temperature, for example, 15 to 25°C. The vacuum can be applied for the duration of the curing process for example, 10 to 180 min, for example, 40 to 120 min. The temperature can then be increased to greater than or equal to 50°C, for example, 60 to 150°C, for example, 85 to 145°C at l°C/min. The multilayer stack can be held at this temperature under vacuum pressure for greater than or equal to 10 min, for example, 20 to 60 min, for example, 30 to 45 min. The sample temperature can then be allowed to return to room temperature before removing from the oven and releasing the vacuum pressure. The polymer layer can be dried in an oven for 1 to 14 hrs at the glass transition temperature of the polymer prior to lamination, specifically, 250°F (121 °C) for PC.

[0101] The multilayer article can be a window pane, a wind screen, a wind shield, a wall panel (such as a partition wall), a light fixture, a sign (such as a graphic sign), a door (such as a compartment, a cabinet, a trolley, a train, a platform edge door). The multilayer article can include one or more functional layers such as a vacuum metallization layer, a vapor deposition layer, or a metal foil, for example, for a mirror, a one way mirror, or a two way mirror. The multilayer article can include one or more functional layers such as a conductive ink system, a dielectric ink system, an integrated circuit board, and a touch sensing system like CIMA/SANTE technology that allows for is not limited to actuation of imbedded LED lights through touch or proximity sensing, actuation of haptic feedback through touch or proximity sensing. The multilayer article can include one or more functional layers such as a wire mesh or an otherwise conductive grid designed to block microwaves or radio waves.

[0102] The following examples are provided to illustrate the flame retardant properties of the multilayer article. The examples are merely illustrative and are not intended to limit devices made in accordance with the disclosure to the materials, conditions, or process parameters set forth therein. Examples

[0103] The materials listed in Table 1 were used in the below examples, where SIP is for

SABIC's Innovative Plastics business and STR is for Specialized Technology Resources.

Examples 1-6: FAR testing of dual sided multilayer articles.

[0104] Dual sided multilayer articles with hardened glass layer, TPU or HALS free EVA interlayers, and polycarbonate polymer layers were prepared and tested for compliance with FAR as shown in Table 2.

[0105] Heat release testing was performed on 15.2 x 15.2 cm plaques 1.5 mm thick using the OSU 65/65 rate-of-heat release apparatus, in accordance with the method shown in FAR

25.853 (d), and in Appendix F, section IV (FAR F25.4). Total heat release was measured up to the two-minute mark in kW-min/m ² . Peak heat release was measured as kW/m ² . The heat release test method is also described in the "Aircraft Materials Fire Test Handbook"

DOT/FAA/AR-00/12, Chapter 5 "Heat Release Test for Cabin Materials." In order to obtain a "pass," the two-minute total heat release had to be less than or equal to 65 kW-min/m ² and the peak heat release rate had to be less than or equal to 65 kW/m ² .

[0106] Flame Spread per the method shown in ASTM E-162 was performed on 15.24cm x 45.72cm samples with thicknesses ranging from 5 to 17 mm. In order to obtain a "pass", the Flame Spread Index had to be less than or equal to 100. Smoke density and toxicity testing per the methods shown in ASTM E-162, ASTM E-662-83, Bombardier SMP 800-C, ASTM F-814- 83, Airbus ABD0031, and Boeing BSS 7239 was performed on 7.5 x 7.5 cm plaques with thicknesses ranging from 5 to 17 mm. Smoke density was measured under flaming mode at 4.0 min. In order to obtain a "pass," the smoke density had to have an optical density of less than or equal to 200 at 4 min. In order to obtain a "pass" for the toxicity tests, the toxic gas generated from material combustion could not exceed the specified maxima as indicated here with for the associated toxic gasses: 3,500 for carbon monoxide, 90,000 for carbon dioxide, 100 for nitrogen oxides, 100 for sulfur dioxide, 500 for hydrogen chloride, 100 for hydrogen fluoride, 100 for hydrogen bromide, 100 for hydrogen cyanide. Smoke Generation according to the method shown in FAR 25.853 (d), Amendment No. 25-83, and in Appendix F, section V (DOT/FAA/AR- 00/12)(FAR F25.5) was performed on 7.62 cm x 30.48 cm samples with thicknesses ranging from 5 to 17 mm. In order to obtain a "pass," the specific optical density at 4.0 min of the smoke emission had to be less than or equal to 200.

[0107] Table 2 shows that the multilayer articles with glass layer thicknesses, TPU interlayers or HALS free EVA interlayers, and polycarbonates with and without bromine flame retardant polymer layer were able to pass the FAR for flame spread, smoke density, smoke generation, and toxicity.

Table 2

Example 1 2 3 4 5 6

Interlayer material TPU TPU EVA EVA EVA EVA

Polymer NonFRPC NonFRPC NonFRPC NonFRPC FRPC3 FRPC3 First glass layer (mm) 0.7 0.7 0.7 0.7 0.7 0.7

First TPU layer (mm) 0.38 1.27 0.46 0.46 0.46 0.46

Polymer layer (mm) 3.18 12.7 6.35 12.7 6.35 12.7

Second TPU layer (mm) 0.38 1.27 0.46 0.46 0.46 0.46

Second glass layer (mm) 0.7 0.7 0.7 0.7 0.7 0.7

Flame spread: ASTM El 62 Pass Pass Pass Pass Pass Pass

Smoke density: ASTM E662 Pass Pass Pass Pass Pass Pass

Smoke generation: FAR 25.853

Pass Pass Pass Pass Pass Pass (d) Appendix F Part V

Toxicity: SMP 800C and

Pass Pass Pass Pass Pass Pass Boeing BSS 7239

Examples 7-14: Ballistic testing of single and dual sided multilayer articles.

[0108] Single sided multilayer articles (Examples 7-8), dual sided multilayer articles (Example 9-12), and single polycarbonate layers (Examples 13 and 14) were prepared and tested for compliance with Ballistic and Block tests according to the FRR and are shown in Table 3.

[0109] Table 3 shows that for a single sided multilayer article, the glass layer should be greater than or equal to 0.7 mm and the polymer layer should be greater than or equal to 6 mm in order to pass the Ballistic and Block tests. Table 3 shows that for a dual sided multilayer article, the glass layer should be greater than or equal to 0.7 mm and the polymer layer should be greater than or equal to 9 mm in order to pass the Ballistic and Block tests. Table 3 shows that the polymer layer without any glass laminate should be greater than or equal to 12 mm in order to pass the Ballistic and Block tests.

Examples 15-18: Curved multilayer articles.

[0110] The fact that a multilayer article comprising a hardened glass layer could retain a curvature was surprising. In fact, it was theorized that glass layer would break when an outer strain produced a stress that exceeded the compressive stress of the glass. For example, using the equation, p=Et/2ab, it is possible to determine the maximum theoretical radius of curvature of the hardened glass layer that can be obtained, where the radius of curvature, p, is equal to the Young's Modulus multiplied by the thickness, t, of the glass and divided by two times the compressive stress, ab, in the glass.

[0111] Table 9 below shows the calculated theoretical radius of curvature of the glass layers based on the radius of curvature equation and ab values obtained from the datasheets of two commercially available chemically hardened glass products and one commercially available soda lime glass product. Table 9 also shows the actual measured radius of curvature of the glass layers as measured during a two point bend test that was used to test the theory. The actual radius of curvature is the maximum radius of curvature (where the smaller the radius the higher the curvature) achieved at break.

[0112] Table 4 shows that the radius of curvature, R, of the hardened glass was as little as 5.2 cm, where Examples 15 to 17 all had bending radii of less than 10 cm. This R is significantly smaller than the R of the soda lime glass of Example 18 of 72.1 cm. Table 4 further shows that the theoretical values for radius of curvature are within a factor of two of the actual radius of curvature values. It is noted that the difference between the theoretical bend radius and the actual bend radius can be attributed to one or more of four primary factors, including differences in the actual E for the given sample and the value reported in the datasheet, differences in the actual compressive stress and the value reported in the datasheet, error in measuring the bend radius at the time of failure, and flaws in the edge of the glass that cause premature failure of the glass when subjected to strain.

[0113] Curvature can be imparted into the multilayer article during a lamination process. The curvature can be such that a stress level in the glass does not exceed the compressive stress in the glass. For example, a multilayer article was prepared by laminating a polymer to a glass layer with an interlayer material. The article had a length of 3 feet (0.91 m), a width of 2 feet (0.61 m), a thickness of 0.25 inches (6.35 mm), a radius of curvature of 42.5 inches (107 cm) in the length direction and a radius of curvature of 144.25 inches (366 cm) in the width direction. The resulting calculated maximum stresses in the sample are 23.8 MPa and 7.00 MPa, respectively. [0114] An appropriate safety factor, S, can be applied to ensure robust performance to application specifications. A safety factor, S, can be factored into the minimum radius determination, for example, a safety factor of greater than or equal to 2X, greater than or equal to 3X, or greater than or equal to 4X. The safety factor or stress limit can accommodate for flaws in the glass, manufacturing inconsistencies, and stress that will be seen in the actual application environment. For example, various safety factors can be applied and are shown for Examples 15- 18 in Table 4.

Example 19: Impact test of a multilayer article.

[0115] A dual sided multilayer article having FST2 polymer layers laminated onto both sides of a hardened glass layer with HALS free EVA interlayers therebetween was prepared. The polymer layer was 3 mm thick and the interlayers were 0.45 mm thick. The article had a length of 1,075 mm, a width of 658 mm, a thickness of 5 mm, and a radius of curvature of 486.5 mm in the length direction. The resulting calculated stress in the sample was 53.58 MPa, which equates to a safety factor of 14.93. The impact resistance was tested according to a pendulum test, ANSI Z97.1-2009, with a 45.4 kg mass dropped from a height of 1,220 mm. Surprisingly, it was found that the article passed the impact test.

[0116] Set forth below are some embodiments of the present multilayer article and methods of making.

[0117] Embodiment 1: A method of making a curvilinear multilayer article comprising: preparing a multilayer stack comprising a first hardened glass layer, a first polymer layer, and a first interlayer located in between the first hardened glass layer and the first polymer layer;

deforming the multilayer stack to form a curvilinear multilayer stack; increasing a temperature of the curvilinear multilayer stack from a first temperature to a second temperature and increasing a pressure exerted on the curvilinear multilayer stack from a first pressure to a second pressure; and reducing the temperature to a reduced temperature and reducing the pressure to a reduced pressure to form the curvilinear multilayer article. The first hardened glass layer comprises a strengthened (e.g., chemically strengthened or heat strengthened, or both) glass having a surface compressive stress of 250 MPa to 1 ,000 MPa and a depth of layer of compressive stress of greater than or equal to 40 μηι. The first polymer layer comprises a polysiloxane, a polyester (such as polyethylene terephthalate), a nylon, an aliphatic polyamide, a semi-aromatic polyamide, a polycarbonate, an acrylic, a cast acrylic, an acrylonitrile butylstyrene, a polybutylterephthalate, a polyetherimide, a poly(ether ether ketone), a poly(l,4-cyclohexane-dimethanol-l,4- cyclohexanedicarboxylate), or a composition comprising one or more of the foregoing. The first hardened glass layer is 0.3 to 1.5 mm, the first interlayer is 0.2 to 1.4 mm, and the first polymer layer is 0.1 to 15 mm. [0118] Embodiment 2: The method of Embodiment 1, wherein the first temperature is 15 to 25°C.

[0119] Embodiment 3: The method of any of the preceding embodiments, wherein the second temperature is greater than or equal to 35°C, or greater than or equal to 70°C.

[0120] Embodiment 4: The method of any of the preceding embodiments, comprising holding the second temperature for greater than or equal to 3 minutes prior to increasing the pressure.

[0121] Embodiment 5: The method of any of the preceding embodiments, further comprising increasing the second temperature to a third temperature.

[0122] Embodiment 6: The method of Embodiment 5, wherein the third temperature is greater than or equal to 100°C, or greater than or equal to 120°C.

[0123] Embodiment 7: The method of any of Embodiments 5-6, further comprising maintaining the third temperature for greater than or equal to 10 min.

[0124] Embodiment 8: The method of any of Embodiments 5-7, further comprising increasing the second temperature to the third temperature after increasing the pressure.

[0125] Embodiment 9: The method of any of the preceding embodiments, wherein the second pressure is greater than or equal to 0.1 MPa, or greater than or equal to 0.4 MPa, or 0.1 to 1 MPa.

[0126] Embodiment 10: The method of any of the preceding embodiments, comprising maintaining the second pressure for greater than or equal to 20 min.

[0127] Embodiment 11: The method of any of the preceding embodiments, wherein the reduced temperature is less than or equal to 60°C.

[0128] Embodiment 12: The method of any of the preceding embodiments, further comprising vacuum bagging the multilayer stack prior to increasing the temperature and increasing the pressure.

[0129] Embodiment 13: The method of any of the preceding embodiments, wherein the increasing the pressure comprises increasing a vacuum pressure, wherein the second pressure is a vacuum second pressure; and reducing the pressure comprises reducing a vacuum pressure.

[0130] Embodiment 14: The method of Embodiment 13, wherein the vacuum second pressure is 0 to 0.11 MPa.

[0131] Embodiment 15: The method of any of Embodiments 13-14, wherein the second vacuum pressure is maintained for greater than or equal to 10 min.

[0132] Embodiment 16: The method of any of Embodiments 13-15, further comprising adding an additional pressure of 0.2 to 1 MPa to the vacuum pressure. [0133] Embodiment 17: The method of any of the preceding embodiments, further comprising, after increasing the temperature and the pressure, and prior to reducing the temperature and the pressure; waiting for greater than or equal to 15 minutes.

[0134] Embodiment 18: The method of any of the preceding embodiments, wherein the multilayer stack further comprises a second glass layer and a second interlayer.

[0135] Embodiment 19: The method of Embodiment 18, wherein the second glass layer is a hardened glass layer having a surface compressive stress of 250 to 1 ,000 MPa and a depth of layer of compressive stress greater than or equal to 40 μηι; wherein the second glass layer is 0.3 to 1.5 mm and the second interlayer is 0.2 to 1.4 mm.

[0136] Embodiment 20: The method of any of the preceding embodiments, wherein the first interlayer and/or the second interlayer of Embodiments 18 or 19 each independently comprises a TPU, an EVA, an ionoplast composition, a silicone, a polyvinyl butyral, or a combination comprising one or both of the foregoing; specifically, one or both of a TPU and an EVA, wherein the EVA comprises 0 to 0.01 wt% HALS.

[0137] Embodiment 21: The method of any of the preceding embodiments, wherein the polymer layer comprises one or more of a polysiloxane copolymer and an organophosphorus compound in an amount effective to provide 0.1 to 1.0 wt% of phosphorus, based on the total weight of the polymer layer.

[0138] Embodiment 22: The method of any of the preceding embodiments, wherein the multilayer stack further comprises a decorative and/or functional layer.

[0139] Embodiment 23: The curvilinear multilayer article formed by any of the preceding embodiments.

[0140] Embodiment 24: The curvilinear multilayer article of Embodiment 23, wherein the curvilinear multilayer article is a double paned article comprising two articles each formed independently from the method of any of Embodiments 1-22; a gap located in between the two articles; and a frame or gasket surrounding an edge of the two articles and forming the gap.

[0141] Embodiment 25: A curvilinear multilayer article comprising a first hardened glass layer, a first polymer layer, and a first interlayer located in between the first hardened glass layer and the first polymer layer; wherein the first hardened glass layer comprises a strengthened (e.g., chemically strengthened, heat strengthened, or both) glass having a surface compressive stress of 250 MPa to 1000 MPa and a depth of layer of compressive stress greater than or equal to 40 μηι; wherein the first polymer layer comprises a polysiloxane, a polyester (such as polyethylene terephthalate), a nylon, an aliphatic polyamide, a semi-aromatic polyamide, a polycarbonate, an acrylic, an acrylonitrile butylstyrene, a polybutylterephthalate, a

polyetherimide, a poly(ether ether ketone), a poly(l,4-cyclohexane-dimethanol-l,4- cyclohexanedicarboxylate), or a composition comprising one or more of the foregoing; wherein the first hardened glass layer is 0.3 to 1.5 mm, the first interlayer is 0.2 to 1.4 mm, and the first polymer layer is 0.1 to 15 mm.

[0142] Embodiment 26: The article of any of Embodiments 23-25, wherein the article is a pane, a wind screen, a windshield, a panel, a light fixture, a sign, or a door.

[0143] Embodiment 27: The article of any of Embodiments 23-26, further comprising one or both of a decorative layer and a functional layer (such as an ultraviolet resistant layer and an abrasion resistant layer).

[0144] Embodiment 28: The article of any of Embodiments 24-27, wherein the article can achieve a radius of curvature of less than or equal to 50 cm, specifically, less than or equal to 25 cm, more specifically, less than or equal to 10 cm as determined by a three point bend test.

[0145] Unless specified, the test methods (for example, ASTM or ISO tests) referred to herein are the most recent as of January 1, 2015.

[0146] In general, the invention may alternately comprise, consist of, or consist essentially of, any appropriate components herein disclosed. The invention may additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants or species used in the prior art compositions or that are otherwise not necessary to the achievement of the function and/or objectives of the present invention.

[0147] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of "up to 25 wt%, or, more specifically, 5 to 20 wt%", is inclusive of the endpoints and all intermediate values of the ranges of "5 to 25 wt%," etc.). "Combination" is inclusive of blends, mixtures, alloys, reaction products, and the like. Furthermore, the terms "first," "second," and the like, herein do not denote any order, quantity, or importance, but rather are used to denote one element from another. The terms "a" and "an" and "the" herein do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The suffix "(s)" as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., the film(s) includes one or more films). Reference throughout the specification to "one embodiment," "another embodiment," "an embodiment," and so forth, means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments. [0148] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to Applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.

[0149] Compounds are described using standard nomenclature. For example, any position not substituted by any indicated group is understood to have its valency filled by a bond as indicated, or a hydrogen atom. A dash ("-") that is not between two letters or symbols is used to indicate a point of attachment for a substituent. For example, -CHO is attached through carbon of the carbonyl group. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments.

[0150] With respect to the figures, it is noted that these figures (also referred to herein as "FIG.") are merely schematic representations based on convenience and the ease of

demonstrating the present disclosure, and are, therefore, not intended to indicate relative size and dimensions of the devices or components thereof and/or to define or limit the scope of the exemplary embodiments. Although specific terms are used in the description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the description herein, it is to be understood that like numeric designations refer to components of like function.

[0151] All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

[0152] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.

[0153] I/we claim: