Abstract: The present disclosure relates to a polyimide-based resin film comprising a polyimide-based resin containing a polyimide repeating unit represented by Chemical Formula 1 and a polyimide repeating unit represented by Chemical Formula 2, a substrate for display device, and an optical device using the same.

Abstract: A composition comprising a polyimide or a precursor thereof including a tetracarboxylic dianhydride residue and an amine residue having at least one aromatic group, and a clay mineral modified with an organic cation having at least one aromatic group, wherein the content of the clay mineral with respect to 100 parts by mass of the polyimide or a precursor thereof is more than 3.0 parts to 10 parts by mass, and wherein the cured product is colorless and transparent, or a polyimide film having a coefficient of linear expansion of 10 ppm or less, a glass transition temperature of 450° C. or more, a Yellow index of 10 or less, and a total light transmittance of 80% or more.

Abstract: Provided according to the present invention is a substrate for a flexible display device in which the problems of threshold voltage shift-induced current fluctuation and resultant image sticking can be solved by introducing an imide monomer as an organic filler into a polyamic acid composition to enhance thickness and surface direction densities in the film that is manufactured while vulcanization is performed at high temperatures, thereby enhancing thermal diffusivity and thermal conductivity of the film.

Abstract: The present disclosure relates to a polyimide-based polymer film comprising a polyimide-based polymer containing a polyimide repeating unit synthesized by the reaction of an acid anhydride compound having a specific structure and a diamine compound, wherein a glass transition temperature is 400° C. or more, and a thickness direction retardation value at a thickness of 10 ?m is 150 nm or less, and a substrate for a display device and an optical device using the same.

Abstract: The present disclosure relates to a polyimide-based polymer film comprising a polyimide-based polymer containing a polyimide repeating unit synthesized by the reaction of an acid anhydride compound having a specific structure and a diamine compound, wherein an average transmittance at a wavelength of 380 nm or more and 780 nm or less is 60% or more, and a thickness direction retardation value at a thickness of 10 pm is 150 nm or less, and a substrate for a display device, a circuit board, an optical device, and an electronic device using the same.

Abstract: The present disclosure is directed to providing a support substrate for a display device capable of obtaining high transparency while accomplishing thinning and flexibility of an organic EL display device. In view of the above, the present disclosure provides a support substrate for a display device including a TFT glass substrate having a thickness of 10 ?m to 150 ?m, and a polyimide resin layer having a thickness of 150 nm or less installed in contact with the TFT glass substrate.

Abstract: A polyimide film according to the present invention can be effectively used as a substrate for a flexible display device without a deterioration in heat resistance even at a temperature of 350° C. or higher since a coefficient of thermal expansion (A) in the section of 100-350° C., of the polyimide film, and a coefficient of thermal expansion (B) in the section of 350-450° C., of the polyimide film, meet 0<B/A<2.

Abstract: The present invention relates to a polyimide precursor composition, and a polyimide film manufactured using same. According to the present invention, since a polyimide film is manufactured from a mixture of a polyimide precursor having a structure that is advantageous to surface charge accumulation and a polyimide precursor having a structure capable of exhibiting high heat-resistant characteristics, a flexible device using the polyimide film as a substrate can have both improved charge accumulation characteristics caused by an electric field to be generated during the operation of a TFT device and heat high heat-resistant characteristics.

Abstract: According to the present invention, a stack comprises, between a carrier substrate and a flexible substrate layer, a peeling power adjustment layer comprising polyimide, which has a refractive index higher than that of the flexible substrate layer, so that a flexible substrate can be more easily peeled from a carrier substrate layer, and thus a flexible element can be manufactured without damage to the element through a simpler process.

Abstract: The present disclosure relates to a polyimide-based resin film which is synthesized by the reaction of an acid anhydride compound having a specific structure and a diamine compound, thereby capable of ensuring excellent optical properties even under high temperature heat treatment conditions, and stably maintaining optical properties even during further heat treatment, a substrate for display device, and an optical device using the same.

Abstract: The present disclosure relates to a polyimide-based resin film which is synthesized by the reaction of an acid anhydride compound and a diamine compound having a specific structure, thereby capable of ensuring excellent flatness even under high temperature heat treatment conditions, and stably maintaining flatness even during further heat treatment, a substrate for display device, and an optical device using the same.

Abstract: Provided according to the present invention is a substrate for a flexible display device in which the problems of threshold voltage shift-induced current fluctuation and resultant image sticking can be solved by introducing an imide monomer as an organic filler into a polyamic acid composition to enhance thickness and surface direction densities in the film that is manufactured while vulcanization is performed at high temperatures, thereby enhancing thermal diffusivity and thermal conductivity of the film.

Abstract: A method for producing a device substrate by obtaining a laminate comprising a carrier substrate with a first polyimide film disposed on at least one surface of the carrier substrate, a second polyimide film disposed on the first polyimide film, applying a physical stimulus to the second polyimide film without causing chemical changes in the first polyimide film such that the adhesive strength of the first polyimide to the second polyimide film decreases and separating the second polyimide film from the first polyimide film formed on the carrier substrate to obtain the device.

Abstract: A polyimide precursor solution containing a reaction product of tetracarboxylic acid anhydride and diamine in a molar ratio of 1:0.93 to 1:0.99. The polyimide precursor solution contains a polyimide precursor having a number average molecular weight of at least 38,000 g/mol and can thus produce a polyimide film having high heat resistance. A polyimide precursor solution having improved storage stability can be provided by quantifying the defoaming properties of the solution and controlling the content of bubbles. Moreover, a polyimide film produced therefrom has a reduced amount of bubbles in the film, and can thus suppress the formation of cracks that can form in an inorganic layer when forming a device.

Abstract: A polyimide film according to the present invention can be effectively used as a substrate for a flexible display device without a deterioration in heat resistance even at a temperature of 350° C. or higher since a coefficient of thermal expansion (A) in the section of 100-350° C., of the polyimide film, and a coefficient of thermal expansion (B) in the section of 350-450° C.

Abstract: The present invention relates to a laminate and a device fabricated using the laminate. The laminate includes a debonding layer including a polyimide resin between a carrier substrate and a flexible substrate. The adhesive strength of the debonding layer to the flexible substrate is changed by a physical stimulus. According to the present invention, the flexible substrate can be easily separated from the carrier substrate without the need for further processing such as laser or light irradiation. Therefore, the use of the laminate facilitates the fabrication of the device having the flexible substrate. The device may be, for example, a flexible display device. In addition, the device can be prevented from deterioration of reliability and occurrence of defects caused by laser or light irradiation. This ensures improved characteristics and high reliability of the device.

Abstract: The present invention can provide a method for manufacturing a polyimide with improved thermal stability that has no contraction even at a high temperature, by adjusting the amount of an acid anhydride in the preparation of a polyimide precursor, and a polyimide film manufactured by the method causes residual stress in a substrate during a high-temperature thermal treatment procedure, thereby suppressing the occurrence of problems, such as cracks in an inorganic film or delamination of a film.

Abstract: A method for producing a device substrate by obtaining a laminate comprising a carrier substrate, a first polyimide film comprising a first polyimide resin disposed on at least one surface of the carrier substrate, a second polyimide film disposed on the first polyimide film opposite to the surface of the first polyimide film formed on a surface of the carrier substrate; applying a physical stimulus to the second polyimide film without causing chemical changes in the first polyimide film such that the cross-sections of the second polyimide film are exposed and cross-sectional surfaces of the first polyimide film are not exposed and no physical stimulus is applied to the surface of the carrier substrate, wherein the adhesive strength of the first polyimide to the second polyimide film decreases when the second polyimide film in the laminate is cut to expose cross-sectional surfaces of the second polyimide film; and separating the second polyimide film from the first polyimide film formed on the carrier substra

Abstract: The present invention relates to a laminate and a device fabricated using the laminate. The laminate includes a first polyimide resin layer between a carrier substrate and a second polyimide resin layer, wherein the first polyimide resin layer has a coefficient of thermal expansion (CTE) equal to or lower than the CTE of the second polyimide-based resin layer at a temperature of 100 to 200° C., and the adhesive strength of the first resin layer to the second resin layer decreases when a physical stimulus causing no chemical changes in the first resin layer is applied to the laminate. According to the present invention, the flexible substrate can be easily separated from the carrier substrate without the need for further processing such as laser or light irradiation. Therefore, the use of the laminate facilitates the fabrication of the device having the flexible substrate. The device may be, for example, a flexible display device.

Abstract: The present invention relates to a laminate and a device fabricated using the laminate. The laminate includes a debonding layer including a polyimide resin having a similarity score not greater than 0.5, as calculated by Equation 1 defined in the detailed description, between a carrier substrate and a flexible substrate. According to the present invention, the flexible substrate can be easily separated from the carrier substrate without the need for further processing such as laser or light irradiation. Therefore, the use of the laminate facilitates the fabrication of the device having the flexible substrate. The device may be, for example, a flexible display device. In addition, the device can be prevented from deterioration of reliability and occurrence of defects caused by laser or light irradiation. This ensures improved characteristics and high reliability of the device.