Abstract: An embodiment can provide a method for producing a polyamide-imide film which is colorless and transparent and has excellent mechanical properties, the method comprising: a step of producing a polyamide-imide polymer solution by polymerizing an aromatic diamine compound, an aromatic dianhydride compound, and a dicarbonyl compound; a step of producing a gel sheet by extruding, casting and drying the polymer solution; and a step of producing a polyamide-imide film by heat-treating the gel sheet, wherein the viscosity of the polymer solution is 100,000 to 500,000 cps, and the polyamide-imide film has a yellowness index of 5 or lower, a haze of 2% or lower, a transmittance of 85% or above and a modulus of 5.0 GPa or above, at a thickness of 20 ?m to 75 ?m.

Abstract: An embodiment can provide a polyamide-imide film and a method for producing same, the film comprising a polyamide-imide polymer formed by polymerizing an aromatic diamine compound, an aromatic dianhydride compound and a dicarbonyl compound, wherein, in an XRD graph with a section in which 2?=8° to 32° as a baseline, the film shows a peak area of 50% or above around 2?=23° with respect to a peak area seen around 2?=15°.

Abstract: The embodiments relate to a polyamide-imide film excellent in optical properties and mechanical properties, to a process for preparing the same, and to a cover window and a display device comprising the same. There are provided a polyamide-imide film, which comprises a polyamide-imide polymer and has a reduced modulus of a top surface measured by the nanoindentation method according to the ISO 14577-2 standard of 5.6 GPa or more and a haze of 1% or less, a process for preparing the same, and a cover window and a display device comprising the same.

Abstract: Embodiments relate to a process for preparing a poly(amide-imide) film and a poly(amide-imide) film prepared thereby. The process is capable of preparing a poly(amide-imide) film that is excellent in optical properties and mechanical properties.

Abstract: Embodiments relate to a polyamide-imide film that secures excellent tensile toughness and elastic restoring force, and a process for preparing the same. The polyamide-imide film comprises a polyamide-imide polymer formed by polymerizing a diamine compound, a dianhydride compound, and a dicarbonyl compound, wherein the area value up to the yield point derived by the 0.2% off-set method on a stress-strain curve of the polyamide-imide film as measured using a universal testing machine (UTM) is 80 to 150 J/m2.

Abstract: Embodiments provide a polyamide-imide polymer film, which comprises a polyamide-imide polymer formed by polymerizing a diamine compound, a dianhydride compound, and a dicarbonyl compound; and silica particles, wherein the number of aggregates having an average diameter of 150 to 200 nm observed in a cross-section cut in the thickness direction of the polyamide-imide film is less than 0.5/?m2, and a process for preparing the same.

Abstract: The embodiments relate to a polyamide-based film excellent in optical properties, mechanical properties, and processing suitability and to a cover window and a display device comprising the same. The polyamide-based film comprises a polyamide-base polymer, wherein a dipolar solvent compatibility represented by the following equation is 18.5 to 24: Dipolar solvent compatibility=?{square root over ((?d??1d)2+(?p??1p)2)}. In the equation, ?d is a value of a dispersible component in surface energy of the polyamide-based film, ?p is a value of a polar component in surface energy of the polyamide-based film, ?1d is a value of a dispersible component in Hansen solubility parameter of the dipolar solvent, and ?1p a value of a dipolar component in Hansen solubility parameter of the dipolar solvent.

Abstract: One embodiment may provide a method for producing a polyimide film, the method comprising the steps of: polishing the surface of a casting body; producing a gel sheet by casting a precursor on the polished surface of the casting body, and drying same; and producing a polyimide film by heat-treating the gel sheet, wherein the roughness of the polished surface of the casting body is 0.1 nm to 160 nm, and when the area of the casting body onto which the precursor is casted is partitioned by 1 cm×1 cm, the area corresponding to a defect reduction region is at least 90%, and the polyimide film has a yellowness of at most 3, a haze of at most 1%, a permeability of at least 88%, a modulus of at least 5.0 GPa and a surface hardness of at least HB.

Abstract: The embodiments relate to a polyamide-based film excellent in optical properties such as transmittance, haze, and yellow index and mechanical properties such as modulus and thickness uniformity, to a process for preparing the same, and to a cover window and a display device comprising the same. The polyamide-based film comprises a polyamide-based polymer and has an XRD pattern comprising a first peak whose highest point is located in a section where 2? is 14° to 16°.

Abstract: The embodiments relate to a polyamide-based composite film that not only has excellent curl characteristics, mechanical properties, and optical properties, but also exhibits a privacy protection effect at a wide angle of view and glossiness characteristics similar to those glass at a main angle of view, and to a display device comprising the same. There are provided a polyamide-based composite film that comprises a base film comprising a polyamide-based polymer; and a functional layer disposed on the base film, wherein a glossiness control value according to Equation 1 is 0 or more, and a displace device comprising the same.

Abstract: One embodiment may provide a polyamide-imide film which is colorless and transparent while having an adequate level of solubility and excellent mechanical properties, the polyamide-imide film comprising a polyamide-imide polymer formed by polymerizing an aromatic diamine compound, an aromatic dianhydride compound and a dicarbonyl compound, wherein, for a square cross-section of 1 cm×1 cm and a thickness of 30 um to 100 mm, the polyamide-imide film has a dissolution time of 5-60 minutes in 10 ml of dimethylacetamide (DMAc), and for a thickness of 50 mm, the polyamide-imide film has a yellowness of at most 5, a haze of at most 2%, a permeability of at least 85% and a modulus of at least 5.0 GPa.

Abstract: Embodiments provide a polyamide-imide polymer film, which comprises a polyamide-imide polymer formed by polymerizing a diamine compound, a dianhydride compound, and a dicarbonyl compound; and silica particles, wherein the number of aggregates having an average diameter of 150 to 200 nm observed in a cross-section cut in the thickness direction of the polyamide-imide film is less than 0.5/?m2, and a process for preparing the same.

Abstract: Embodiments relate to a base film that is colorless, transparent, and excellent in mechanical properties and optical properties, particularly with low moisture permeability, a process for preparing the same, and a cover window and a display device comprising the same. The cover window comprises a base film comprising a polyamide-based polymer and having a moisture permeability of 300 g/m2·day or less; and a functional layer.

Abstract: Embodiments relate to a polymer film that is excellent in folding characteristics and transparency and maintains excellent mechanical properties even after repeated elongation and shrinkage in the elastic region, a process for preparing the same, and a front panel and a display device comprising the same. The polymer film comprises a polymer resin selected from the group consisting of a polyamide-based resin and a polyimide-based resin and has an MOR0/9 of Equation A of 2% or less.

Abstract: Embodiments relate to a polyamide-based film that is colorless and transparent, is excellent in mechanical properties and optical properties, has a wide angle of view by securing at least a certain level of luminance at various angles, and, in particular, has gloss characteristics similar to those of glass, a process for preparing the same, and a cover window comprising the same. The polyamide-based film comprises a polyamide-based polymer, wherein when the polyamide-based film is placed on a surface light source, light is irradiated from the surface light source, and the luminance value (L0) measured in the normal direction of the surface light source is 100%, the luminance value (L50) measured in the direction of 50° from the normal direction of the surface light source is 25% or more.

Abstract: Embodiments relate to a polymer film. The polymer film comprises a polymer resin selected from the group consisting of a polyamide-based resin and a polyimide-based resin and has a haze (HZ0) before autoclave treatment of 3% or less and a ?HZ24 represented by Equation 1a of 500% or less.

Abstract: Embodiments relate to a polyamide-imide film that maintains its mechanical properties at least at a certain level under the conditions of high temperatures and low temperatures and is excellent in transparency and folding characteristics, a process for preparing the same, and a cover window comprising the same. The polyamide-imide film comprises a polyamide-imide polymer and has an MOR value defined in Equation 1a of 75% or more.

Abstract: Embodiments relate to a polyamide-imide film that has a clean appearance and transparency and is excellent in antiblocking properties, a process for preparing the same, and a display front panel and a display device comprising the same. The polyamide-imide film comprises a polyamide-imide polymer formed by polymerizing a diamine compound, a dianhydride compound, and a dicarbonyl compound; and a filler, wherein the dicarbonyl compound comprises a first dicarbonyl compound and a second dicarbonyl compound, the first dicarbonyl compound and the second dicarbonyl compound are structural isomers to each other, and the FH value of Equation 1 is 0.5 or less.

Abstract: Embodiments relate to a polymer film for a display that maintains a clean appearance and transparency and is excellent in antiblocking properties by securing a certain range of optical slip index (OS), a process for preparing the same, and a front panel and a display device comprising the same. The polymer film comprises a polymer resin selected from the group consisting of a polyamide-based resin and a polyimide-based resin and a filler and has an optical slip index (0.5) of less than 0.5.

Abstract: The embodiments relate to a polyimide-based film, which comprises a first side and a second side opposite to the first side, wherein the modulus asymmetry (MA) according to Equation 1 is 0.03 to 0.2, a process for preparing the same, and a display device comprising the same.