阅读说明：本技术 多层聚合物膜及其制造方法 (Multilayer polymer film and method of making same ) 是由 阿德尔·法齐·巴斯塔罗斯 周渊 冯威 汤春桃 于 2018-06-04 设计创作，主要内容包括：一种多层聚合物膜,包括顶层,顶层包含聚(甲基丙烯酸甲酯)；底层,底层包含底层组合物,底层组合物包含聚(甲基丙烯酸甲酯)、聚碳酸酯、其共聚物或包括前述中的至少一种的组合,其中底层组合物的玻璃化转变温度小于或等于140℃；以及内层,内层设置在顶层的内表面和底层的内表面之间,其中内层包含聚碳酸酯。(A multilayer polymeric film comprising a top layer comprising poly (methyl methacrylate); a primer layer comprising a primer layer composition comprising poly (methyl methacrylate), polycarbonate, a copolymer thereof, or a combination comprising at least one of the foregoing, wherein the primer layer composition has a glass transition temperature of less than or equal to 140 ℃; and an inner layer disposed between the inner surface of the top layer and the inner surface of the bottom layer, wherein the inner layer comprises polycarbonate.)

1. A multilayer polymeric film comprising:

a top layer comprising poly (methyl methacrylate);

a base layer comprising a base layer composition comprising poly (methyl methacrylate), polycarbonate, a copolymer thereof, or a combination comprising at least one of the foregoing, wherein the base layer composition has a glass transition temperature of less than or equal to 140 ℃; and

an inner layer disposed between an inner surface of the top layer and an inner surface of the bottom layer, wherein the inner layer comprises polycarbonate.

2. The multilayer polymer film of claim 1, wherein the bottom layer has a glass transition temperature of from 100 ℃ to 140 ℃, preferably wherein the glass transition temperature is 100 ℃

To 110 ℃, more preferably wherein the glass transition temperature is 110 ℃.

3. The multilayer polymeric film of claim 1 or claim 2, wherein the underlayer composition comprises a copolymer of polycarbonate and polyester, preferably wherein the polyester comprises an amorphous polyester.

4. The multilayer polymeric film of any of the foregoing claims, wherein the underlayer composition comprises a poly (aliphatic ester) polycarbonate copolymer.

5. The multilayer polymeric film of any of the foregoing claims, wherein the thickness of the top layer is from 5 microns to 30 microns.

6. The multilayer polymeric film of any of the foregoing claims, wherein the thickness of the inner layer is from 50 microns to 200 microns.

7. The multilayer polymeric film of any of the foregoing claims, wherein the thickness of the bottom layer is from 1 micron to 10 microns.

8. The multilayer polymer film of any one of the preceding claims, wherein the outer surface of the base layer has an average surface roughness Rz measured according to ISO4287 of less than or equal to 0.75 microns, preferably wherein the average surface roughness Rz is less than or equal to 0.5 microns.

9. The multilayer polymeric film of any of the preceding claims, further comprising a film directly laminated to an outer surface of the base layer, preferably wherein the film is an optical film.

10. An article comprising the multilayer polymeric film of any of the foregoing claims, preferably wherein the article is an electronic display, a flat panel display, a window, or a light cover, preferably wherein the article is a computer screen, a tablet, a mobile device, a television screen, a projection display, a traffic signal, or a billboard, more preferably wherein the electronic display is a high definition display, most preferably wherein the high definition display is an ultra-high definition display, even more preferably wherein the ultra-high definition display is an ultra-high definition television screen.

11. An optical film for use in an electronic display, comprising:

an optical film and the multilayer polymeric film of any one of claims 1-9 disposed on a single-sided outer surface or both-sided outer surfaces of the optical film.

12. An electronic display, comprising:

a light guide;

an optical film disposed adjacent to the lightguide, wherein the multilayer polymeric film of any of claims 1-9 is disposed on either or both sides of the optical film;

an image generator disposed adjacent to the optical film; and

a substrate disposed adjacent to the image generator.

13. A method of making the multilayer polymeric film of any one of claims 1-9, comprising:

coextruding the top layer, the bottom layer, and the inner layer, the inner layer disposed between an inner surface of the top layer and an inner surface of the bottom layer.

14. The method of claim 13, further comprising laminating an outer surface of the bottom layer directly to an optical film.

15. The method of any one of claims 13-15, further comprising texturing an outer surface of the underlayer to an average surface roughness Rz measured according to ISO4287 of less than or equal to 0.75 microns, preferably wherein the average surface roughness Rz is less than or equal to 0.5 microns.

16. A multilayer polymeric film comprising:

a top layer comprising a material having a glass transition temperature of 100 ℃ to 150 ℃;

a bottom layer comprising a bottom layer composition; and

an inner layer disposed between an inner surface of the top layer and an inner surface of the bottom layer, wherein the inner layer has a glass transition temperature of 125 ℃ to 175 ℃;

wherein the glass transition temperature of the inner layer is 0.25 to 75 ℃ lower than the glass transition temperature of the top layer or the bottom layer.

17. The multilayer polymeric film of claim 16, wherein the top layer comprises poly (methyl methacrylate), the bottom layer comprises a bottom layer composition comprising poly (methyl methacrylate), polycarbonate, copolymers thereof, or a combination comprising at least one of the foregoing; and the inner layer comprises polycarbonate.

18. The multilayer polymeric film of claim 16 or claim 17, wherein the underlayer composition comprises a copolymer of polycarbonate and polyester, preferably wherein the polyester comprises an amorphous polyester, more preferably wherein the underlayer composition comprises a poly (aliphatic ester) polycarbonate copolymer.

19. The multilayer polymeric film of any of claims 16-18, further comprising a film directly laminated to an outer surface of the base layer, preferably wherein the film is an optical film.

20. The multilayer polymer film of any one of claims 16-19, wherein the outer surface of the base layer has an average surface roughness Rz measured according to ISO4287 of less than or equal to 0.75 microns, preferably wherein the average surface roughness Rz is less than or equal to 0.5 microns.

Background

Multilayer films are used in a variety of electronic and display products. Multilayer films can provide functionality and alternatives as compared to standard laminates consisting of multiple monolayer films adhered to each other with an adhesive or adhesive layer. To address performance challenges, cost reduction requirements, and customer demand for thinner thin film stacks, it is desirable to integrate different types of functional optical films into a single film. Such integration can provide thinner films, efficiency, and cost savings during assembly, and improve optical performance by reducing the amount of light lost through the film.

The film may be configured to direct, diffuse, or polarize light. Brightness Enhancing Films (BEFs) are used to direct light along a viewing axis by using structures such as prisms on their surfaces. Such BEF films enhance the brightness of the display viewed by the user and allow for less power to be consumed in creating the desired level of on-axis illumination. BEF films may be used in a wide variety of applications including, but not limited to, televisions, computer screens, projection displays, traffic signals, and other illuminated signs. A reflective polarizing film, such as a Dual Brightness Enhancement Film (DBEF), is a recycling light management film used to increase the brightness of a backlight used in a Liquid Crystal (LCD) display or Light Emitting Diode (LED). In other words, the reflective polarizing film is a thin film reflective polarizer that increases brightness over the entire viewing range. The reflective polarizing film is a component of the backlight module, which can increase brightness. The reflective polarizing film may capture and use light that is normally lost to absorption in the bottom LCD polarizer and redirect it to allow the light to exit the liquid crystal backlight assembly at a desired angle. The reflective polarizing film recycles light from the backlight by using a recycling optics mechanism that allows the light to pass through many layers of refractive index optical material and be totally reflected.

Thus, there is a need for integrated articles and films that provide superior functionality compared to current optical film stacks.

Disclosure of Invention

In various embodiments, a multilayer polymeric film and methods of making the same are disclosed.

A multilayer polymeric film includes a top layer comprising poly (methyl methacrylate); a primer layer comprising a primer layer composition comprising poly (methyl methacrylate), polycarbonate, a copolymer thereof, or a combination comprising at least one of the foregoing, wherein the primer layer composition has a glass transition temperature of less than or equal to 140 ℃; and an inner layer disposed between the inner surface of the top layer and the inner surface of the bottom layer, wherein the inner layer comprises polycarbonate.

A multilayer polymeric film comprising: a top layer comprising a material having a glass transition temperature of 100 ℃ to 150 ℃; a primer layer comprising a primer composition; and an inner layer disposed between the inner surface of the top layer and the inner surface of the bottom layer, wherein the inner layer has a glass transition temperature of 125 ℃ to 175 ℃; wherein the bottom layer has a glass transition temperature 0.25 to 75 ℃ lower than the glass transition temperature of the top or inner layer.

These and other features and characteristics will be described in more detail below.

Drawings

The following is a brief description of the drawings in which like elements are numbered alike and which are presented for the purpose of illustrating the exemplary embodiments disclosed herein and not for the purpose of limiting the same.

Fig. 1 is a sectional view of a liquid crystal display.

Fig. 2 is a cross-sectional view of a thin film transistor.

Fig. 3A is a side view of reflected light in a system without an optical film.

FIG. 3B is a side view of reflected light in a system with an optical film.

Fig. 3C is a view of light passing through a system having an optical film.

Fig. 4A is a view of light passing through a system without an optical film.

Fig. 4B is a view of light passing through a system having an optical film.

Fig. 5 is a view of the layers of the optical film and the multilayer polymeric film prior to attachment of the two to each other.

Fig. 6 is a view of a multilayer polymeric film attached to an optical film.

Fig. 7 is a view of two multilayer polymeric films attached to an optical film.

Fig. 8 is a schematic diagram of an extruder configuration for making the multilayer polymeric films disclosed herein.

Fig. 9 is a schematic view of a melt calendering system for making a multilayer polymeric film.

Fig. 10 is a detailed view of certain elements of the calendaring system of fig. 10.

Fig. 11 is a view of various end use products of the multilayer polymeric films disclosed herein.

Detailed Description

Adhesives are commonly used to bond films together. Without the adhesive, the adhesion is inadequate and/or the multiple layers must be heated to a temperature that adversely affects optical performance (e.g., results in an increase in yellowness index). When an adhesive is used, sufficient adhesive strength can be obtained. However, the adhesive can adversely affect the optical properties of the final article, creating defects between the films (e.g., bubbles, delamination, reduced brightness, reduced light transmittance, etc.). In the present disclosure, it is determined that surface texture is added to the surface of the layer to be bonded, and wherein the layer is made of a composition having a glass transition temperature (Tg) 0.25 ℃ to 75 ℃ lower than the glass transition temperature of the top layer or inner layer, an adhesive layer is not required, and optical properties can be maintained. The glass transition temperature of the base layer may be such that it can be heated to its softening during lamination to another film. Without wishing to be bound by theory, it is believed that during the lamination process, the heat from the lamination process softens the bottom layer, but does not affect the top or middle layers. Furthermore, the multilayer films disclosed herein may provide a simpler process without the additional steps required when using adhesives or bonding layers.

Disclosed herein are multilayer polymeric films and methods of making the same. Multilayer polymeric films can provide enhanced lamination properties when the film is attached to another film without the use of an adhesive layer therebetween. The multilayer polymeric film may be attached to another film, such as an optical film, wherein attachment of one side of the multilayer polymeric film layer to the other film will have a fine texture as defined below, and it will have a glass transition temperature of less than 140 ℃. For example, a multilayer polymeric film can include a top layer, a bottom layer, and an inner layer disposed between the top layer and the bottom layer. The glass transition temperature of the underlayer composition may allow lamination of a multilayer polymeric film to another film without including any structural or mechanical properties of one film and without an adhesive layer therebetween. The roughness value (e.g., Rz) of the outer surface (e.g., bottom surface) of the bottom layer can be less than or equal to 0.75 μm, such as less than or equal to 0.5 μm. These roughness levels can facilitate successful lamination of the multilayer film to another film without the use of an adhesive or adhesive layer. Higher roughness values can adversely affect the lamination of a multilayer polymer film to another film. The multilayer films disclosed herein may provide improved surface properties, such as pencil hardness, which may avoid the additional step of applying a coating on the multilayer film to prevent scratches and other markings.

The top layer of the multilayer film may be made of poly (methyl methacrylate). The top layer can be configured to provide scratch resistance to the multilayer polymeric film. The inner layer may be made of polycarbonate. The inner layer can be configured to provide mechanical strength and optical properties to the multilayer polymeric film. The base layer can be configured to provide enhanced lamination properties when the multilayer polymeric film is attached to another film. It has been unexpectedly discovered that the addition of a surface texture to the outer surface (i.e., bottom surface) of a base layer and the use of a base layer composition having a glass transition temperature of less than 140 c allows a multilayer polymeric film to be directly laminated to another optical film without the use of an adhesive or adhesive layer therebetween. For example, when a multilayer polymeric film is directly attached to an optical film, such as a Brightness Enhancing Film (BEF) or a reflective polarizing film (e.g., a Dual Brightness Enhancing Film (DBEF)), a base layer can provide enhanced lamination without an adhesive layer disposed therebetween.

The multilayer films described herein include at least three layers of transparent thermoplastic resin. As used herein, transparent means that each thermoplastic resin has a light transmission (Tvis) of at least 85%. As used herein, light transmittance and haze are measured according to a gardner haze-plus haze meter designed according to ASTM D1003-00, procedure a, equipped with a D65 illuminant and a 10 degree observation angle. For example, the multilayer film may include a top layer, a bottom layer, and an inner layer disposed between the top layer and the bottom layer. The top layer may be made of a material that provides scratch resistance and abrasion resistance while maintaining optical properties. The pencil hardness of the top layer can be greater than or equal to 2B, e.g., H, e.g., 2H, e.g., H-2H, at a thickness of 5 to 20 micrometers (μm). The top layer may be a material such as poly (methyl methacrylate). The top layer may include a major surface texture as described below. The primary surface texture on the outer surface (i.e., top surface) of the top layer affects the mechanical wear behavior of the multilayer article, and therefore requires an abrasion resistant material.

The inner layer may comprise a material comprising polycarbonate.

The bottom layer can include a bottom layer composition that includes a material that is transparent and has a Tg less than or equal to 140 ℃ (e.g., 95 ℃ to 130 ℃, e.g., 100 ℃ to 110 ℃). The base layer can include a base layer composition comprising PMMA, polycarbonate, polyester, or a combination comprising at least one of the foregoing, such as a polycarbonate-based copolymer, blend, or alloy. The base layer may include a base layer composition made of PMMA. The underlayer composition may include a copolymer of polycarbonate and polyester (e.g., amorphous polyester). The underlayer composition may include a poly (aliphatic ester) polycarbonate copolymer. The underlayer composition may have a lower glass transition temperature than ordinary polycarbonate. For example, the underlayer composition may have a lower glass transition temperature than the polycarbonate used in the inner layer. The glass transition temperature of the underlayer is less than or equal to 140 ℃. The glass transition temperature of the underlayer may be from 100 ℃ to 140 ℃. The glass transition temperature of the underlayer may be from 100 ℃ to 110 ℃. The glass transition temperature of the underlayer may be 110 ℃. The lower glass transition temperature of the bottom layer helps to allow the multilayer polymeric film to be laminated to another film without damaging the structural features of the multilayer film, such as the major surface texture, or the structural features of the film to which it is attached. The glass transition temperature may allow the underlying composition to soften at a sufficiently low temperature that it does not compromise the structural integrity, physical or mechanical properties of the multilayer film or film to which it is attached during lamination to an optical film.

The thickness of each layer depends on the characteristics of the layer. For example, the top layer has a top layer thickness sufficient to accommodate the texture of the major surface. The top layer thickness may be greater than 1.5 times Rz of the major surface texture. Rz can be generally described as the maximum height of the evaluation profile, given by the sum of the highest peak of the profile (Rp) and the deepest valley of the profile (Rv), averaged over the number of sample lengths within the evaluation length of the profile. In other words, the top layer thickness may be 1 micrometer (μm) to 50 μm, for example 1 μm to 30 μm or 5 μm to 30 μm. The thickness of the inner layer may be 25 μm to 300 μm, for example 50 μm to 200 μm. The thickness of the bottom layer may be 0.5 μm to 25 μm, for example 1 μm to 10 μm. The light management function of the multilayer film can be addressed with a surface texture having light management capabilities (e.g., diffusing capabilities or light turning/directing capabilities). For example, a primary surface texture for light management functions is created on the outer surface, i.e., the top surface, of the top layer.

When diffusing capability is desired, the generally random rough surface texture of the rough topography including non-specific geometric shaped peaks and valleys can provide a strong light diffusing function and a uniform light distribution over the surface area of the film. Typically a rough surface is generally characterized by standard surface finish properties, such as average roughness (Ra) or peak count (Rpc). The diffuser film has a generally rough surface (referred to herein as "fine texture") with Ra less than 1.2 micrometers (μm) and Rpc greater than 50 peaks/centimeter (peaks/cm), which is beneficial for excellent image quality, such as Ultra High Definition (UHD) displays. For example, for UHD displays and similar applications, a diffuser film having a rough surface with Ra less than 1.0 μm and Rpc greater than 80peaks/cm may be more advantageous. A diffuser film with a rough surface with Ra less than 0.7 μm and Rpc greater than 100peaks/cm is even more advantageous for displays. When the texture of the sheet has a relatively large average roughness (e.g., Ra >1.2 μm) and Rpc is below 50peaks/cm, for example, when used in display applications, the sheet may have a grainy appearance. Without being bound by theory, this is believed to be caused by the optical lensing of large peak or valley surface features at discrete and isolated surface locations. When the size of the peak or valley features is comparable to or larger than the pixel size of the display, the grainy appearance becomes visible and is considered a defect. The peak count (Rpc) refers to the number of locally rough peaks and valleys projected through the selectable band centered on the contour. This number was determined over the entire length of the assessment and reported as the number of peaks per centimeter. The surface roughness (Ra) and the number of peaks (Rpc) are measured using a standard surface profile meter, such as a Kosaka1700a profile meter from the tokyo Kosaka laboratory, japan. The instrument is configured and surface profile parameters such as Ra, Rp, Rv, Rz and Rpc are measured following the procedure specified in ISO 4287: 1997. According to ISO4287, Rz is given by the sum of the highest profile peak (Rp) and the deepest profile valley (Rv). A scan length of at least 5.6mm (giving a net evaluation length of at least 4.0 mm), a gaussian data filter, and a 0.8mm filter cutoff were used. For peak number, a symmetric band of ± 0.5 μm around the mean line of the profile is set as the report Rpc. For the examples and comparative examples in this application, the surface profile data of the surface texture was measured by 5 profile scans along the extrusion direction (i.e., machine direction) of the film/sheet web and another 5 profile scans along the cross direction of the web, and then the average surface profile data of a total of 10 scans was recorded as the result.

When light turning/directing capability is desired, a special structured surface texture comprising a plurality of uniquely geometrically shaped micro-structured elements (such as micro-lenses, prisms, pyramids or lenticular lenses) can provide, for example, light turning functionality while providing the hiding capability required to mask light source placement details or structured patterns on the display components. The surface texture of a particular structure is generally characterized by the geometric properties of the individual microstructure elements.

The top layer, the major surface texture on the top surface, can include a plurality of geometric microstructure elements including microlenses, polyhedral shapes (e.g., prisms, pyramidal shapes, cube-corner shapes, etc.), lenticular shapes, generally rough surface features, and combinations comprising at least one of the foregoing. The average aspect ratio (i.e., height to width) of these geometries is greater than or equal to 0.05. The major surface texture may include only generally rough surface textures having a Ra of 1.2 microns or less and a Rpc of 50peaks/cm or more. Alternatively, the major surface texture can be produced by including one or more protruding additive particles at least partially embedded in the top layer of the multilayer polymeric article.

The underlayer can have an outer surface with an average surface roughness Rz of less than or equal to 0.75 μm, for example less than or equal to 0.5 μm. The bottom layer may have a random surface texture because the bottom layer is not as responsible for light management as the top layer. The lower Rz of the bottom layer helps ensure successful lamination with another film. As described herein before, Rz is given by the sum of the highest profile peak (Rp) and the deepest profile valley (Rv) according to ISO 4287. A scan length of at least 5.6mm (giving a net evaluation length of at least 4.0 mm), a gaussian data filter and a 0.8mm filter cut-off were used. Without wishing to be bound by theory, it is believed that a lower Rz, e.g., less than or equal to 0.75 μm, e.g., less than or equal to 0.5 μm, can play an important role in successfully attaching, e.g., laminating, a multilayer polymeric film to another film, e.g., an optical film, such as a reflective polarizing film (e.g., DBEF).

A method of making a multilayer polymeric film can include coextruding a top layer, an inner layer, and a bottom layer. A single screw co-extrusion line may be used with a main extruder and two co-extruders. The extruder may include a vacuum vent, a screen changer, a melt pump, an adapter with distributor bolts, and a multi-layer die. Any commercial film extrusion line system can produce the multilayer films disclosed herein.

The extrusion may be performed with the polymeric material entering the first co-extruder, the second co-extruder, and the main extruder. The polymeric material will enter the barrel of each extruder through the feed throat and be heated until it is in a molten (flowing) state. Screws (e.g., single or twin screws) within the extruder barrel push the molten polymeric material out of the barrel outlet and toward the die. The die may be a multi-manifold die configured to accept multiple extrudates from multiple extruders. The extrudates from each extruder may be combined within a die to form a multilayer polymeric film. After exiting the die, the formed multilayer polymeric film can be passed through a calendering system, such as a melt calendering system, to provide texture to the top surface of the top layer and the bottom surface of the bottom layer.

It should be noted that the roller is not limited by its material structure. The texture on the multilayer film is replicated from the roll. For example, the surface texture of the top layer may come from a roll and the surface texture of the bottom layer may come from another roll. The rollers may be made of rubber or steel. The replication rate of each roll can reach 80% -95%.

As previously described, once the multilayer film has been formed, the multilayer polymeric film may be attached to another article, such as another film or structure. For example, the outer surface (e.g., bottom surface) of a bottom layer of a multilayer polymeric film can be directly laminated to another film. The base layer may be laminated to another film without the use of an adhesive or adhesive layer, or any other layer or material therebetween. The lamination process includes heating the bottom surface and the surface of the article to which the bottom surface will be attached to a temperature above the Tg of the bottom layer, such as greater than or equal to 110 ℃, such as greater than or equal to 120 ℃, such as 130 ℃ to 170 ℃, orienting the surfaces to be attached adjacent to each other, and once that temperature is reached, applying pressure to attach the multilayer film and the article together. The absence of an adhesive layer allows for direct attachment (e.g., lamination) to another article, which helps maintain or improve optical performance while simplifying the manufacturing process and reducing overall cost.

For example, a multilayer film may be attached to another film, such as an optical film (e.g., BEF, reflective polarizing film (DBEF), for example, in systems such as backlights and other display systems (e.g., reflective polarizing film (DBEF)), which may replace polycarbonate diffusion films and adhesive layers. With the multilayer polymeric films disclosed herein, the use of an adhesive layer can be avoided without compromising the ability of the multilayer polymeric film to successfully attach to another film, e.g., without bubbles or lines at the interface between the two films.

The multilayer polymeric film may be attached by a lamination process. The multilayer polymeric film may be attached to either or both sides of the optical film. The optical film may include a polyethylene terephthalate film.

The article may be made from a multilayer polymeric film. The article can be used in a variety of applications, such as UHD televisions, including thin film transistor LED UHD televisions. The article may also be used in computer monitors/displays, high definition televisions, billboards, projection displays, traffic signals, and other illuminated signs. An electronic display can include a light guide, an optical film surrounded on either or both sides by a multilayer polymeric film described herein, an image generator (e.g., a liquid crystal material, plasma, light emitting diode, etc.), and a substrate disposed adjacent to the liquid crystal material.

The multilayer articles are useful as light diffusing films or sheets for flat panel displays, digital displays, windows, lamp covers, and other applications where the light diffusing effect and mechanical or abrasion resistance of the article are advantageous.

A more complete understanding of the components, processes, and devices disclosed herein may be obtained by reference to the accompanying drawings. These drawings (also referred to herein as "figures") are merely schematic representations based on convenience and the ease of presenting the present disclosure, and are, therefore, not intended to indicate relative dimensions and specifications 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 following 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 following description, it is to be understood that like numerals refer to like features.

In fig. 1, a cross-section of a liquid crystal display 40 is shown. The liquid crystal display 40 comprises a liquid crystal material 44 surrounded on both sides by a first substrate 42 and a second substrate 48. The first substrate 42 and the second substrate 48 may be made of glass or a polymeric material. A sealing material 46 may surround the liquid crystal material 44 to hold the liquid crystal material 44 in place. The sealing material 46 may include a polymeric resin such as silicone, epoxy, uv curable resin, or the like. Spacers 58 may be present on either or both sides of the liquid crystal material 44. The top surface of the outermost layer of the liquid crystal display may be a first polarizing film 60 followed by a first barrier film 62 underneath (i.e., between the polarizing film 60 and the first substrate 42). The first barrier film 62 may be disposed adjacent to the first substrate 42. A second barrier film 64 may be disposed adjacent the second substrate 48, and a second polarizing film 66 is disposed adjacent the second barrier film 64. An optical film 68 (e.g., BEF, reflective polarizing film (DBEF), etc.) may be disposed between the polarization separation film 50 and the diffuser film 24, with the polarization separation film 50 disposed adjacent to the second polarizing film 66. Light guide plate 54 may be positioned below a multilayer polymer film 24 (e.g., diffuser film 24) and a reflector sheet 56 is disposed below light guide plate 54. Although not shown in fig. 1, it should be understood that another multilayer polymeric film 24 may be adjacent to another surface of the optical film 68 such that the optical film 68 is disposed between two multilayer polymeric films 24. The backlight 52 may be positioned adjacent to the light guide plate 54 and the reflective sheet 56. The backlight 52 may include Light Emitting Diodes (LEDs). The backlight 52 may include a Cold Cathode Fluorescent Lamp (CCFL).

Fig. 2 is a technique for a Thin Film Transistor (TFT) LCD. The TFT LCD is a type of LCD that uses TFT technology to improve image quality such as resolution and contrast. TFT LCDs may be used in a variety of appliances, including televisions, computer monitors, cell phones, handheld video game consoles, personal digital assistants, navigation systems, projection, and appliances such as refrigerators. TFTs are Field Effect Transistors (FETs) made by depositing thin films of active semiconductor layers, dielectric layers, and metal contacts on a supporting non-conductive substrate. The substrate may be glass or a polymeric material. In a TFT LCD, transistors are embedded in the LCD panel itself, reducing the amount of cross-talk between pixels, thereby improving image stability. The structure of the TFT display is shown in fig. 2. Fig. 2 does not include an actual light source (LED or CCFL).

As shown in fig. 2, the TFT display 100 includes a substrate 1 in which a vertical polarizing plate 2 and a horizontal polarizing plate 3 are the outermost surfaces of the TFT display 100. Color masks (e.g., red, green, blue ("RGB") color masks) 4 may be located between the substrates 1. The spacers 8 may be arranged between the polymer layers 7. A vertical command line 5 and a horizontal command line 6 may be located near the TFT 9. The front electrode 10 and the back electrode 11 may be used to contact non-metallic portions of the TFT display 100. Accordingly, the TFT display 100 may be arranged as follows: the liquid crystal display panel comprises a first polaroid, a first substrate, a color shadow mask, a front electrode, a first polymer layer, a spacer, a second polymer layer, a rear electrode, a second substrate and a second polaroid forming an angle of 90 degrees with the first polaroid. Also between the second polymer layer and the back electrode are command lines 5,6 and a TFT 9.

Turning now to fig. 3A and 3B, light output with and without BEF optics is shown. In fig. 3A, BEF is not present. It can be seen that the reflected beam 76 leaves the screen towards the viewer, but there are several areas of wasted light 72, 74 that are outside the viewing angle. Further, it should be noted that the reflected beam 76 exiting the optic 78 is not as bright as the reflected beam exiting the optic with the BEF due to wasted light 72, 74. In fig. 3B, BEF82 is present (see fig. 3C). It can be seen that the reflected light beam 77 exiting the optical device 80 is directed to the viewer while reducing or eliminating the wasted light shown in fig. 3A. Thus, it should be noted that beam 77 exiting optics 80 is brighter than beam 76. Fig. 3C illustrates how BEF82 refracts, reflects, and recycles the light beam toward the viewer, thereby reducing light waste. Backlight 84, including lamps 86 (which may be LCDs, CCFLs, etc.) may direct light to BEF 82. BEF82 may refract light toward a viewer with refracted light beam 90. The BEF may recycle the wasted off-axis light by reflecting the light back to the BEF82 to be recycled via the recycling beam 92. These light beams 92 are reflected from the reflector plate 56 back through the BEF82 toward the viewer. Fig. 3B and 3C demonstrate the effectiveness of BEFs in optical devices to enhance and improve the quality of refracted, reflected, and recycled light.

Fig. 4A and 4B illustrate various light outputs of optical devices with and without a reflective polarizing film (e.g., DBEF 94). In fig. 4A, the reflective polarizing film is not present. As shown in FIG. 4A, the light, after exiting the backlight 84, is transmitted through the LCD 88 via a first polarized light beam 102. The LCD may be surrounded by a first polarizer 96 and a second polarizer 98. The first and second polarizers 96, 98 may help reduce the amount of glare present in the light output to the viewer. The same amount of light (approximately 50%) is absorbed before reaching the LCD 88 through the second polarized light beam 104. In contrast, in fig. 4B, reflective polarizing film 94 is present, and multilayer polymer film 24 is disposed on either side of reflective polarizing film 94. The multilayer optical film 24 may be a diffuser film. Light exiting backlight 84 may be transmitted through LCD 88 by first and second polarized light beams 102, 104, greatly reducing the amount of light absorbed by the LED as compared to the absence of a reflective polarizing film. As shown in fig. 4A, the light from the lamp 86 is an electromagnetic wave. Light from the first polarized light beam 102 may pass through the second polarizer 98 and the first polarizer 96, and light from the second polarized light beam 104 may be absorbed by the first polarizer 96. However, in FIG. 4B, if reflective polarizing film 94 is added, reflective polarizing film 94 may reflect light from second polarized light beam 104 to backlight 84, passing only light from first polarized light beam 102, before second polarizer 98 and first polarizer 96 are able to absorb the light. The reflective polarizing film increases brightness and light output by reflecting and recycling polarized light, as shown in FIG. 4B, from the second polarized light beam 104 back to the backlight 84, where the polarized light is recycled and output as the bottom first polarized light beam 102 in FIG. 4B.

Turning now to FIG. 5, the structure of the multilayer polymeric film 24 is shown along with the optical sheets 28 before the multilayer polymeric film 24 is attached. The multilayer polymeric film 24 includes an inner layer 22, the inner layer 22 being disposed between and in direct physical contact with the top layer 14 and the bottom layer 18. The bottom layer 18 includes a bottom (outer) surface 17, the bottom surface 17 having a fine texture 21 therein. Top layer 14 includes a top (outer) surface 15, top surface 15 including optical microstructure elements 19 therein.

The multilayer polymeric film 24 may be attached to either or both sides of the optical film 28, for example, by a lamination process. Fig. 6 shows an optical film 28 with a multilayer polymeric film 24 attached to one surface of the optical film 28. Fig. 7 shows an optical film 28 with a multilayer polymeric film 24 attached to both surfaces of the optical film 28.

Turning now to fig. 8, an extruder arrangement 10 for making a multilayer polymeric film 24 is shown. In fig. 8, a first co-extruder 16 is used to extrude top layer 14. The second co-extruder 12 is used to extrude the bottom layer 18. The main extruder 20 is used to extrude the inner layer 22. It should be understood that first co-extruder 12 and second co-extruder 16 may produce either top layer 14 or bottom layer 18. Top layer 14, bottom layer 18, and inner layer 22 may be passed through a multi-manifold co-extrusion die 26 to form a multilayer polymeric film 24.

The texture may be applied to the top layer 14 and the bottom layer 18 by cylindrical rollers 30, 31, 32. A texture may be applied to the top surface 15 of the top layer 14 and the bottom surface 17 of the bottom layer 18. Texturing can be accomplished using various methods, such as calendaring, embossing, and other methods, as well as combinations comprising at least one of the foregoing methods. For example, Bastawros et al disclose some techniques, systems, and tools for texturing in U.S. patent No. 7,889,427, which is incorporated herein by reference in its entirety.

In the method of making the multilayer sheet 24, polymeric material in the form of pellets, granules, flakes, or powder is placed in the hopper 150 of each respective extruder 12, 16, 20. Polymeric material enters the barrel 154 of each extruder through feed port 152. While in barrel 154, the polymeric material is heated to a molten state, the heating elements and screw elements are located within barrel 154, and the screw elements, which are also located within barrel 154, are pushed through barrel 154. The screw elements may rotate within the barrel up to 120 revolutions per minute (rpm).

Any desired range of screw rotation may be used, based on the size of the extruder, the length to diameter ratio (L/D) of the screw, and any desired pressure within the barrel. Single screw extruders can be used to make optical films due to the lower shear forces imparted to the material. The co-extruder used is typically smaller than the main extruder used to provide the inner layer. The molten extrudate 166 exits the barrel 154 of each extruder 12, 16, 20 and passes through a screen changer/orifice plate assembly 156 to remove any contaminants from the extrudate 166. The screen changer may be reinforced by a perforated plate, which may be a metal disc with a plurality of holes. Screen changer/perforated plate assembly 156 can create a back pressure in barrel 154. The back pressure aids in uniform melting and proper mixing of the polymeric material. The back pressure may vary based on varying screen changer configurations, such as the number of screens, the size of the wire weave within the screens, and other parameters.

After passing through the screen changer/breaker plate assembly 156, the extrudate 166 may pass through a gear pump 158, after which the extrudate 166 passes through a connector, and then the extrudate 166 from each of the three extruders enters a multi-manifold co-extrusion die 26, such as a coat hanger die. Alternatively, the extrudate 166 (i.e., the inner layer 22) from the main extruder 20 may pass through the corner fittings before entering the backing plate 164 and finally entering the multi-manifold coextrusion die 26. Top layer 14, bottom layer 18, and inner layer 22 are combined with a multi-manifold co-extrusion die 26 to form a multilayer polymeric film 24. The mold is the device that imparts the final shape to the film. The mold should be shaped accordingly so that the molten polymeric material flows uniformly through the mold and exits the mold as a final shaped article. After exiting multi-manifold coextrusion die 24, multilayer polymer film 24 enters a melt calendering system to impart texture to top surface 15 of top layer 14 (see fig. 5) and bottom surface 17 of bottom layer 18 (see fig. 5).

Fig. 9 and 10 illustrate an exemplary melt calendering system 110 for producing a textured multilayer polymeric film 24. Topsheet 14 is in contact with a main roll 30 that carries the texture of the major surface of topsheet 14.

As shown in fig. 9, melt calendering system 110 includes three extruders 12, 16, 20 that extrude different polymeric materials for top layer 14, inner layer 22, and bottom layer 18, a multi-manifold co-extrusion die 26, cylindrical rolls 30, 31, 32, 33, 34, 35, 36, 37, 38, where rolls 30 and 31 are first calendering nip rolls, and roll 30 carries the major surface texture pattern of top layer 14 and roll 31 carries the surface texture pattern of bottom layer 18.

The extruders 12, 16, 20 may heat the polymer components above a predetermined temperature to facilitate the flow of the components (e.g., melt the plastic). The output of the extruder is operatively connected to a multi-manifold coextrusion die 26 through the speed setting of a gear pump. The mold 26 may be a vertical mold. The mold 26 may be a horizontal mold.

The cylindrical rolls 30, 31 are configured to receive the multi-layer molten web therebetween from the mold 26, and can form a primary surface texture on a top surface 36 (see fig. 8) of the top layer 14 of the multi-layer polymeric film 24 under nip pressure between the cylindrical rolls 30, 31, and also cool the textured molten web into a textured solid web. The cylindrical rollers 30, 31 may be constructed of metal (e.g., steel) with a rubber or steel surface layer surrounding the metal roller core and operatively connected to a roller cooling system. The roll cooling system maintains the temperature of the rolls 30, 31 below a predetermined temperature to cause the multi-layer molten polymer web to solidify or partially solidify as it passes between the cylindrical rolls 30, 31. The cylindrical roller 31 is configured to receive the multiple layers of polymeric web therebetween from the mold 26 and may form a surface texture on the bottom surface 34 of the bottom layer 18.

To produce an optical film having a structured texture, such as one comprising a plurality of linear prisms or microlenses, a high nip pressure (e.g., greater than 10 bar) is typically applied between the first calendering rolls 30, 31 to ensure that the texture replication from the main roll to the film surface is effective and also uniform across the width of the web. No nip pressure is required between roll 30 and roll 32.

The cylindrical roll 32 is configured to receive the partially cured plastic web after passing between the calendering rolls 30, 31. The position of the cylindrical roller 32 can be adjusted to vary the amount of surface area of the top layer 14 and the bottom layer 18 that contact the cylindrical roller 30. The cylindrical roller 32 is also operatively connected to a roller cooling system (not shown) that maintains the temperature of the cylindrical roller 32 below a predetermined temperature for curing the multilayer polymeric film. The cylindrical roller 32 may be rotated by a motor (rather than relying on friction between the web and the surface of the cylindrical roller 32) in order to minimize web tension that may be applied to the partially cured layers 14, 18, 22 along the machine direction 39. The cylindrical rollers 33 to 38 are downstream conveying rollers, wherein the rollers 35, 36, 37 and 38 are arranged to receive the layers 14, 18, 22 between them and to move the layers 14, 18, 22 downstream.

The speed of each roll as the film passes through the calendering system may depend on the throughput and the thickness of the film, and may be from 10 to 60 meters per minute. The nip pressure between roll 30 and roll 31 may depend on the cosmetic composition of the film and other properties of the film, such as roughness and transmittance. The nip pressure may be less than or equal to 10 megapascals (Mpa) (100 bar). The Ra of the roller 31 is typically higher than the desired Ra of the resulting surface 17, while the Ra of the roller 30 is typically higher than the resulting surface 15. It should be noted, however, that Ra can be any value that provides the desired surface roughness to the produced film. Each roller 30, 31, 32 may have its own motor to drive rotation. Before the start of the extrusion line, each roll 30, 31, 32 may be preheated by a temperature control unit using water as cooling and heating medium, respectively. Other methods may be used to provide the textured surface including, but not limited to, mechanical and chemical processes such as laser, sanding, sand blasting, diamond engraving, and the like.

As used herein, "polycarbonate" refers to a polymer or copolymer having repeating structural carbonate units of formula (1)

Wherein R is¹At least 60% of the total number of radicals being aromatic, or each R¹Comprising at least one C_6-30An aromatic group. Each R¹May be derived from a dihydroxy compound, for example an aromatic dihydroxy compound of formula (2) or a bisphenol of formula (3).

In the formula (2), each R^hIndependent of each otherIs a halogen atom, e.g. bromine, C_1-10Hydrocarbyl radicals (e.g. C)_1-10Alkyl), halogen substituted C_1-10Alkyl radical, C_6-10Aryl or halogen substituted C_6-10Aryl, and n is 0 to 4.

In the formula (3), R^aAnd R^bEach independently is halogen, C_1-12Alkoxy or C_1-12And p and q are each independently an integer of 0 to 4, such that when p or q is less than 4, the valency of each carbon in the ring is filled with hydrogen. In one embodiment, p and q are each 0, or p and q are each 1, and R is^aAnd R^bEach being C meta to the hydroxy group provided on each arylene group_1-3Alkyl groups, such as methyl. X^aIs a bridging group linking two hydroxy-substituted aromatic groups, wherein the bridging group and each C₆Hydroxy substituents of arylene radicals at C₆Ortho, meta or para (e.g. para) to each other on the arylene group, e.g. single bond, -O-, -S-, -S (O) -, -S (O)₂-, -C (O) -or C_1-18An organic group, which may be cyclic or acyclic, aromatic or non-aromatic, and may further comprise heteroatoms such as halogens, oxygen, nitrogen, sulfur, silicon, or phosphorus. For example, X^aC which may be substituted or unsubstituted_3-18A cycloalkylidene group; formula-C (R)^c)(R^d) C of (A-C)_1-25Alkylidene radical, wherein R^cAnd R^dEach independently is hydrogen, C_1-12Alkyl radical, C_1-12Cycloalkyl radical, C_7-12Arylalkyl radical, C_1-12Heteroalkyl or cyclic C_7-12A heteroarylalkyl group; or formula-C (═ R)^e) A group of (a) wherein R^eIs divalent C_1-12A hydrocarbyl group.

Examples of the bisphenol compound include 4, 4' -dihydroxybiphenyl, 1, 6-dihydroxynaphthalene, 2, 6-dihydroxynaphthalene, bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) -1-naphthylmethane, 1, 2-bis (4-hydroxyphenyl) ethane, 1-bis (4-hydroxyphenyl) -1-phenylethane, 2- (4-hydroxyphenyl) -2- (3-hydroxyphenyl) propane, bis (4-hydroxyphenyl) phenylmethane, 2-bis (4-hydroxy-3-bromophenyl) propane, 1-bis (hydroxyphenyl) cyclopentane, 1-bis (4-hydroxyphenyl) cyclohexane, 1, 6-dihydroxynaphthalene, 1, 2-dihydroxynaphthalene, 1-bis (4-hydroxyphenyl) ethane, 1, 2-bis (4-hydroxyphenyl) ethane, 1-bis (4-hydroxyphenyl) cyclohexane, and the like, 1, 1-bis (4-hydroxyphenyl) isobutylene, 1-bis (4-hydroxyphenyl) cyclododecane, trans-2, 3-bis (4-hydroxyphenyl) -2-butene, 2-bis (4-hydroxyphenyl) adamantane, α' -bis (4-hydroxyphenyl) toluene, bis (4-hydroxyphenyl) acetonitrile, 2-bis (3-methyl-4-hydroxyphenyl) propane, 2-bis (3-ethyl-4-hydroxyphenyl) propane, 2-bis (3-n-propyl-4-hydroxyphenyl) propane, 2-bis (3-isopropyl-4-hydroxyphenyl) propane, 2-bis (3-sec-butyl-4-hydroxyphenyl) propane, 2, 2-bis (3-tert-butyl-4-hydroxyphenyl) propane, 2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 2-bis (3-allyl-4-hydroxyphenyl) propane, 2-bis (3-methoxy-4-hydroxyphenyl) propane, 2-bis (4-hydroxyphenyl) hexafluoropropane, 1-dichloro-2, 2-bis (4-hydroxyphenyl) ethylene, 1-dibromo-2, 2-bis (4-hydroxyphenyl) ethylene, 1-dichloro-2, 2-bis (5-phenoxy-4-hydroxyphenyl) ethylene, 4' -dihydroxybenzophenone, methyl ethyl ketone, ethyl ketone, 3, 3-bis (4-hydroxyphenyl) -2-butanone, 1, 6-bis (4-hydroxyphenyl) -1, 6-hexanediol, ethylene glycol bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfone, 9-bis (4-hydroxyphenyl) fluorene, 2, 7-dihydroxypyrene, 6 ' -dihydroxy-3, 3,3 ', 3 ' -tetramethylspiro (bis) indane ("spirobiindane bisphenol"), 3, 3-bis (4-hydroxyphenyl) phthalimide, 2, 6-dihydroxydibenzop-dioxin, 2, 6-dihydroxythianthrene, 2, 7-dihydroxyphenoxafloxacin, 2, 7-dihydroxy-9, 10-dimethylphenazine, 3, 6-dihydroxydibenzofuran, 3, 6-dihydroxydibenzothiophene and 2, 7-dihydroxycarbazole; resorcinol, substituted resorcinol compounds such as 5-methyl resorcinol, 5-ethyl resorcinol, 5-propyl resorcinol, 5-butyl resorcinol, 5-tert-butyl resorcinol, 5-phenyl resorcinol, 5-cumyl resorcinol, 2,4,5, 6-tetrafluoro resorcinol, 2,4,5, 6-tetrabromo resorcinol, etc.; catechol; hydroquinone; substituted hydroquinones, for example, 2-methylhydroquinone, 2-ethylhydroquinone, 2-propylhydroquinone, 2-butylhydroquinone, 2-tert-butylhydroquinone, 2-phenylhydroquinone, 2-cumylhydroquinone, 2,3,5, 6-tetramethylhydroquinone, 2,3,5, 6-tetra-tert-butylhydroquinone, 2,3,5, 6-tetrafluorohydroquinone, 2,3,5, 6-tetrabromohydroquinone, and the like.

Dihydroxy compounds include resorcinol, 2-bis (4-hydroxyphenyl) propane ("bisphenol a" or "BPA"), 3-bis (4-hydroxyphenyl) phthalimide, 2-phenyl-3, 3' -bis (4-hydroxyphenyl) phthalimide (also known as n-phenylphenolphthalein bisphenol, "PPBP" or 3, 3-bis (4-hydroxyphenyl) -2-phenylisoindolin-1-one), 1-bis (4-hydroxy-3-methylphenyl) cyclohexane, and 1, 1-bis (4-hydroxyphenyl) -3,3, 5-trimethylcyclohexane (isophorone bisphenol).

As used herein, "polycarbonate" also includes copolymers comprising carbonate units and ester units ("poly (ester-carbonates)", also known as polyester-polycarbonates). The poly (ester-carbonate) comprises repeating ester units of formula (4) in addition to repeating carbonate chain units of formula (1)

Wherein J is a divalent radical derived from a dihydroxy compound (including reactive derivatives thereof) and may be, for example, C_2-10Alkylene radical, C_6-20Cycloalkylene radical, C_6-20Arylene or polyoxyalkylene groups in which the alkylene groups contain 2 to 6 carbon atoms, for example 2,3 or 4 carbon atoms; and T is a divalent radical derived from a dicarboxylic acid (including reactive derivatives thereof) and may be, for example, C_2-20Alkylene radical, C_6-20Cycloalkylene or C_6-20An arylene group. Copolyesters containing different combinations of T or J groups may be used. The polyester units may be branched or linear.

The dihydroxy compound includes an aromatic dihydroxy compound of formula (2) (e.g., resorcinol), a bisphenol of formula (3) (e.g., bisphenol A), C_1-8Aliphatic diols (e.g., ethylene glycol, n-propylene glycol, 1, 4-butanediol, 1, 6-cyclohexanediol, 1, 6-hydroxymethylcyclohexane), or a combination comprising at least one of the foregoing dihydroxy compounds. Aliphatic dicarboxylic acids which may be used include C_6-20Aliphatic dicarboxylic acids (including terminal carboxyl groups), e.g. straight-chain C_8-12Aliphatic dicarboxylic acids such as sebacic acid (sebacic acid); and alpha, omega-C₁₂Dicarboxylic acids, such as dodecanedioic acid (DDDA). Aromatic hydrocarbon capable of being usedAromatic dicarboxylic acids include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, 1, 6-cyclohexane dicarboxylic acid, or a combination comprising at least one of the foregoing acids. A combination of isophthalic acid and terephthalic acid may be used wherein the weight ratio of isophthalic acid to terephthalic acid is from 91:9 to 2: 98.

The ester units include ethylene terephthalate units, trimethylene terephthalate units, tetramethylene terephthalate units, ester units derived from isophthalic acid, terephthalic acid, and resorcinol (ITR ester units), and ester units derived from sebacic acid and bisphenol a. The molar ratio of ester units to carbonate units in the poly (ester-carbonate) can vary widely, for example from 1:99 to 99:1, such as from 10:90 to 90:10, such as from 25:75 to 75:25, or from 2:98 to 15: 85. In some embodiments, the molar ratio of ester units to carbonate units in the poly (ester-carbonate) can vary from 1:99 to 30:70, such as from 2:98 to 25:75, for example from 3:97 to 20:80, or from 5:95 to 15: 85.

In one embodiment, the polycarbonate is a linear homopolymer containing bisphenol A carbonate units (BPA-PC), available from SABIC under the LEXAN trade name^TMPurchasing; or branched, cyanophenol-terminated bisphenol A homopolycarbonate prepared by interfacial polymerization, containing 3 mole% of a1, 1, 1-tris (4-hydroxyphenyl) ethane (THPE) branching agent, available under the trade name LEXAN from SABIC^TMCFR was purchased.

Other polycarbonates that may be used include poly (aromatic ester-carbonates) comprising bisphenol a carbonate units and isophthalate-bisphenol a ester units, also commonly referred to as Polycarbonate (PCE) or polyphthalate (PPC), based on the relative proportions of carbonate units and ester units. Another poly (ester-carbonate) comprises resorcinol isophthalate and terephthalate units and bisphenol A carbonate units, such as LEXAN, under the trade name SABIC^TMThose available from SLX.

Other polycarbonates that may be used include poly (ester-carbonate-siloxane) s comprising bisphenol a carbonate units, isophthalate-bisphenol a ester units, and siloxane units, e.g., blocks containing 5 to 200 dimethylsiloxane units, such as those available under the trade name FST from SABIC.

Poly (aliphatic ester-carbonates), such as those comprising bisphenol A carbonate units and sebacic acid-bisphenol A ester units, may be used, for example under the trade name LEXAN from SABIC^TMHFD are those commercially available.

Copolycarbonates include bisphenol a and bulky bisphenol carbonate units, i.e., derived from bisphenols containing at least 12 carbon atoms, e.g., 12 to 60 carbon atoms or 20 to 40 carbon atoms. Examples of such copolycarbonates include copolycarbonates comprising bisphenol a carbonate units and 2-phenyl-3, 3' -bis (4-hydroxyphenyl) phthalimidine carbonate units (BPA-PPPBP copolymer, available from SABIC under the trade name XHT), copolymers comprising bisphenol a carbonate units and 1, 1-bis (4-hydroxy-3-methylphenyl) cyclohexane carbonate units (BPA-DMBPC copolymer available from SABIC under the trade name DMC), and copolymers comprising bisphenol a carbonate units and isophorone bisphenol carbonate units (e.g., available from Bayer under the trade name APEC).

Combinations of polycarbonate with other polymers may be used, for example, an alloy of bisphenol a polycarbonate with an ester such as poly (butylene terephthalate) or poly (ethylene terephthalate), each of which may be semi-crystalline or amorphous. Such combinations are available from SABIC under the trade names XENOY and XYLEX.

"polycarbonate" includes homopolycarbonates (wherein each R in the polymer is¹Same), contain different R in the carbonate¹Partial copolymers ("copolycarbonates") and copolymers comprising carbonate units and other types of polymer units, such as ester units or siloxane units.

One copolymer is a poly (ester-carbonate), also known as a polyester-polycarbonate. Such copolymers comprise, in addition to the recurring carbonate units of formula (1), recurring units of formula (5)

Wherein J is derived from a dihydroxy compound (including reactive derivatives thereof)Biological) and may be, for example, C_2-10Alkylene radical, C_6-20Cycloalkylene radical, C_6-20Arylene or polyoxyalkylene in which the alkylene contains 2 to 6 carbon atoms, for example 2,3 or 4 carbon atoms; and T is a divalent radical derived from a dicarboxylic acid (including reactive derivatives thereof) and may be, for example, C_2-20Alkylene radical, C_6-20Cycloalkylene or C_6-20An arylene group. Copolyesters containing different combinations of T or J groups may be used. The polyester units may be branched or linear.

In one embodiment, J is C having a linear, branched, or cyclic (including polycyclic) structure_2-30Alkylene, for example ethylene, n-propylene, i-propylene, 1, 4-butene, 1, 6-cyclohexene or 1, 4-methylenecyclohexane. In another embodiment, J is derived from a bisphenol of formula (3), such as bisphenol A. In another embodiment, J is derived from an aromatic dihydroxy compound of formula (6), such as resorcinol.

Aromatic dicarboxylic acids that may be used to prepare the polyester units include isophthalic or terephthalic acid, 1, 2-bis (p-carboxyphenyl) ethane, 4 '-dicarboxydiphenyl ether, 4' -bisbenzoic acid, or a combination comprising at least one of the foregoing acids. Acids containing fused rings may also be present, such as 1, 4-naphthalenedicarboxylic acid, 1, 5-naphthalenedicarboxylic acid or 2, 6-naphthalenedicarboxylic acid. The dicarboxylic acid comprises terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 1, 4-cyclohexanedicarboxylic acid, or a combination comprising at least one of the foregoing acids. The dicarboxylic acid comprises a combination of isophthalic acid and terephthalic acid wherein the weight ratio of isophthalic acid to terephthalic acid is 91:9 to 2: 98.

Ester units include ethylene terephthalate, n-propyl terephthalate, n-butyl terephthalate, 1, 4-cyclohexanedimethylene terephthalate, and ester units derived from isophthalic acid, terephthalic acid, and resorcinol (ITR). The molar ratio of ester units to carbonate units in the copolymer can vary widely, for example from 1:99 to 99:1, for example from 10:90 to 90:10, for example from 25:75 to 75:25, or from 2:98 to 15:85, depending on the desired properties of the final composition. Poly (ester-carbonates) are those comprising bisphenol a carbonate units and isophthalate-bisphenol a ester units, also commonly referred to as poly (carbonate-ester) (PCE), poly (phthalate-carbonate) (PPC), based on the molar ratio of carbonate units to ester units.

An example of a poly (ester-carbonate) is derived from linear C_6-20Poly (aliphatic ester-carbonates) of aliphatic dicarboxylic acids (including reactive derivatives thereof), e.g. linear C₆-C₁₂Aliphatic dicarboxylic acids (including reactive derivatives thereof). The dicarboxylic acids include n-hexanedioic acid (adipic acid), n-decanedioic acid (sebacic acid), and alpha, omega-C₁₂Dicarboxylic acids, such as dodecanedioic acid (DDDA). The poly (aliphatic ester) -polycarbonate has formula (6):

wherein each R¹Which may be the same or different, as described in formula (1), m is from 4 to 18, for example from 4 to 10, and the average molar ratio x: y of ester units to carbonate units is from 99:1 to 1:99, including from 13:87 to 2:98, or from 9:91 to 2:98, or from 8:92 to 2: 98. In one embodiment, the poly (aliphatic ester) -polycarbonate copolymer comprises bisphenol a sebacate ester units and bisphenol a carbonate units, having, for example, an average molar ratio x: y of 2:98 to 8:92, e.g., 6: 94. Such poly (aliphatic ester-carbonates) are available as LEXAN HFD from SABIC (LEXAN is a trademark of SABIC IP b.v.).

The poly (aliphatic ester-carbonate) can have a weight average molecular weight of 15,000 to 40,000 daltons (Da), including 20,000 to 38,000Da (as measured by GPC based on BPA polycarbonate standards).

Polycarbonates may be manufactured by processes such as interfacial polymerization and melt polymerization, which are known and described, for example, in WO 2013/175448 a1 and WO 2014/072923 a 1. Endcapping agents (also referred to as chain terminators or chain terminators) may be included during the polymerization to provide end groups, for example, monocyclic phenols such as phenol, paracyanophenol, and C₁-C₂₂Alkyl-substituted phenols, e.g. p-cumylphenol, resorcinol monobenzoate and p-tert-butylphenol, monoethers of diphenols, e.g. p-methoxyphenol, monoesters of diphenols, e.g. bisphenol AAcryloyl chloride and methyl chloride, and monochloroformates such as phenyl chloroformate, alkyl-substituted phenyl chloroformate, p-cumyl phenyl chloroformate, and toluene chloroformate. Combinations of different end groups may be used. The branched polycarbonate blocks can be prepared by adding branching agents during the polymerization, such as trimellitic acid, trimellitic anhydride, trimellitic trichloride, triparaben-ethyl ether, isatin-biphenol, trisphenol TC (1,3, 5-tris ((p-hydroxyphenyl) isopropyl) benzene), trisphenol PA (4(4(1, 1-bis (p-hydroxyphenyl) -ethyl) α, α -dimethylbenzyl) phenol), 4-chloroformylphthalic anhydride, trimesic acid and benzophenonetetracarboxylic acid. The branching agent may be added at a level of 0.05 wt.% to 2.0 wt.%. Combinations comprising linear polycarbonates and branched polycarbonates may be used.

Exemplary carbonate precursors include carbonyl halides such as carbonyl bromide or carbonyl chloride (phosgene), bishaloformates of dihydroxy compounds (e.g., the bischloroformate of bisphenol a, hydroquinone ethylene glycol, neopentyl glycol, etc.), and diaryl carbonates. Combinations comprising at least one of the foregoing types of carbonate precursors can also be used. The diaryl carbonate can be diphenyl carbonate, or an activated diphenyl carbonate having an electron-withdrawing substituent on each aryl group, such as bis (4-nitrophenyl) carbonate, bis (2-chlorophenyl) carbonate, bis (4-chlorophenyl) carbonate, bis (methyl salicyl) carbonate, bis (4-methylcarboxyphenyl) carbonate, bis (2-acetylphenyl) carboxylate, bis (4-acetylphenyl) carboxylate, or a combination comprising at least one of the foregoing.

In the preparation of poly (ester-carbonates) by interfacial polymerization, instead of using the dicarboxylic acid or diol directly, reactive derivatives of the diacid or diol, such as the corresponding acid halides, in particular the diacid chlorides and the dibrominated acid, may be used. Thus, for example, instead of using isophthalic acid, terephthalic acid, or a combination comprising at least one of the foregoing acids, isophthaloyl dichloride, terephthaloyl dichloride, or a combination comprising at least one of the foregoing dichlorides can be used.

In addition to the polycarbonates described above, combinations of the polycarbonates with other thermoplastic polymers may be used, for example homopolycarbonates, copolycarbonates and combinations of polycarbonate copolymers with polyesters. Useful polyesters include, for example, polyesters having repeating units of formula (7), including poly (alkylene dicarboxylates), liquid crystalline polyesters, and polyester copolymers. When blended, the polyesters described herein are generally completely miscible with the polycarbonate.

The polyesters may be obtained by interfacial polymerization or melt process condensation as described previously, by solution phase condensation or transesterification polymerization, wherein, for example, a dialkyl ester such as dimethyl terephthalate may be acid catalyzed to exchange with ethylene glycol to form polyethylene terephthalate. Branched polyesters may be used in which a branching agent, such as a glycol having three or more hydroxyl groups or a trifunctional or multifunctional carboxylic acid has been incorporated. Furthermore, depending on the end use of the composition, it may be desirable to have different concentrations of acid and hydroxyl end groups on the polyester.

Copolymers comprising alkylene terephthalate repeat ester units with other ester groups are also useful. Useful ester units may include different alkylene terephthalate units, which may be present in the polymer chain as a single unit or as blocks of polyalkylene terephthalate. Copolymers of this type comprise poly (cyclohexanedimethylene terephthalate) -co-poly (ethylene terephthalate), abbreviated PETG, wherein the polymer comprises greater than or equal to 50 mol% poly (ethylene terephthalate), abbreviated PCTG, wherein the polymer comprises greater than 50 mol% poly (1, 4-cyclohexanedimethylene terephthalate).

The poly (cycloalkylene diester) may also include a poly (alkylene cyclohexanedicarboxylate). One example is poly (1, 4-cyclohexane-dimethanol-1, 4-cyclohexanedicarboxylate) (PCCD), having repeating units of formula (7)

Wherein, as described using formula (5), J is a1, 4-cyclohexanedimethylene group derived from 1, 4-cyclohexanedimethanol, and T is a cyclohexane ring derived from cyclohexanedicarboxylate or a chemical equivalent thereof, and can comprise a cis isomer, a trans isomer, or a combination comprising at least one of the foregoing isomers.

Such polyester and polycarbonate blends are expected to have MVR values of 5 to 150cc/10min measured at 300 ℃ and 1.2 kilogram load according to ASTM D1238-04. For example, 7-125cc/10min, such as 9-110cc/10min, and such as 10-100cc/10 min.

The thermoplastic composition may further comprise an impact modifier. Examples of the impact modifier include natural rubber, fluorine-containing elastomer, ethylene-propylene rubber (EPR), ethylene-butene rubber, ethylene-propylene-diene monomer rubber (EPDM), acrylate rubber, hydrogenated nitrile rubber (HNBR), silicone elastomer, styrene-butadiene-styrene (SBS), styrene-butadiene rubber (SBR), styrene- (ethylene-butylene) -styrene (SEBS), acrylonitrile-butadiene-styrene (ABS), acrylonitrile-ethylene-propylene-diene-styrene (AES), styrene-isoprene-styrene (SIS), styrene- (ethylene-propylene) -styrene (SEPS), methyl methacrylate-butadiene-styrene (MBS), High Rubber Graft (HRG), and the like.

Additive compositions may be used that include one or more additives selected to achieve desired properties, provided that the additives are also selected so as not to significantly adversely affect the desired properties of the thermoplastic composition. The additive composition or individual additives may be mixed at a suitable time during the mixing of the components used to form the composition. The additives may be soluble or insoluble in the polycarbonate. The additive composition can include an impact modifier, a flow modifier, a filler (e.g., polytetrafluoroethylene Particles (PTFE), glass, carbon, mineral, or metal), a reinforcing agent (e.g., glass fibers), an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet light absorbing additive, a plasticizer, a lubricant, a mold release agent (e.g., a mold release agent), an antistatic agent, an antifogging agent, an antimicrobial agent, a colorant (e.g., a dye or pigment), a surface effect additive, a radiation stabilizer, a flame retardant, an anti-drip agent (e.g., a PTFE-encapsulated styrene-acrylonitrile copolymer (TSAN)), or a combination comprising one or more of the foregoing species. For example, a combination of a heat stabilizer, a mold release agent, and an ultraviolet light stabilizer may be used. Generally, the amount of additive is generally known to be effective. For example, the total amount of additive composition (other than any impact modifier, filler, or reinforcing agent) can be 0.001 wt% to 10.0 wt%, or 0.01 wt% to 5 wt%, each based on the total weight of the polymers in the composition.

The polycarbonate compositions can be made by various methods known in the art. For example, the powdered polycarbonate and other optional components are first mixed in a high speed mixer or by hand, optionally with any filler. The mixture is then fed through a hopper into the throat of a twin screw extruder. Alternatively, at least one component may be incorporated into the composition by feeding it directly into the extruder at the throat or downstream through a sidestuffer port, or by mixing it with the desired polymer into a masterbatch which is fed into the extruder. The extruder is typically operated at a temperature higher than that required to enable the composition to flow. The extrudate can be immediately quenched in a water bath and pelletized. The particles so prepared may be one-fourth inch long or shorter as desired. Such particles may be used for subsequent molding, shaping or forming.

Thermoplastic compositions can be made by various methods. For example, powdered polycarbonate, impact modifier, ultraviolet light stabilizer, or other optional components are first blended in

Optionally mixed with a filler in a high speed mixer. Other low shear processes, including but not limited to hand mixing, may also accomplish this mixing. The mixture is then fed through a hopper into the throat of a twin screw extruder. Alternatively, at least one component may be incorporated into the composition by feeding directly into the extruder at the throat or downstream through a sidestuffer. The additives may also be compounded with the desired polymer into a masterbatch which is then fed into the extruder. The extruder is typically operated at a temperature higher than that required to enable the composition to flow. The extrudate was immediately quenched in a water bath and pelletized. The particles so prepared may be one-fourth inch long or shorter as desired. Such particles may be used for subsequent molding, shaping or forming.

The transparent composition may be produced by manipulating the process used to make the polycarbonate composition. An example of such a method of producing a transparent polycarbonate composition is described in U.S. patent application No. 2003/0032725.

Fig. 11 illustrates various examples of electronic display devices in which the multilayer polymeric films described herein are useful. For example, the multilayer polymeric film can be used in mobile devices, television screens, computer monitors, tablet computers, mobile electronic devices such as laptops and automotive security screens.

The following examples are merely illustrative of the multilayer polymeric films disclosed herein and are not intended to limit the scope hereof.