Abstract: A polyamide acid which contains at least one diamine compound selected from among diamine compounds represented by general formula (8) within the range of 3-60 parts by mole in total per 100 parts by mole of all diamine components, while containing a biphenyl tetracarboxylic acid dianhydride within the range of 40-100 parts by mole and a pyromellitic acid dianhydride within the range of 0-60 parts by mole per 100 parts by mole of all acid anhydride components; and a thermoplastic polyimide which is obtained curing this polyamide acid. (In formula (8), linking group X represents a single bond or a divalent group selected from among —CONH—; each Y independently represents a hydrogen atom, a monovalent hydrocarbon group having 1-3 carbon atoms or an alkoxy group; n represents an integer of 0-2; and each of p and q independently represents an integer of 0-4.

Abstract: A polyamide acid which contains at least one diamine compound selected from among diamine compounds represented by general formula (8) within the range of 3-60 parts by mole in total per 100 parts by mole of all diamine components, while containing a biphenyl tetracarboxylic acid dianhydride within the range of 40-100 parts by mole and a pyromellitic acid dianhydride within the range of 0-60 parts by mole per 100 parts by mole of all acid anhydride components; and a thermoplastic polyimide which is obtained curing this polyamide acid. (In formula (8), linking group X represents a single bond or a divalent group selected from among —CONH—; each Y independently represents a hydrogen atom, a monovalent hydrocarbon group having 1-3 carbon atoms or an alkoxy group; n represents an integer of 0-2; and each of p and q independently represents an integer of 0-4.

Abstract: Provided is a display device that can be made thin, lightweight, and flexible, has no problems of cracks and peeling caused by thermal stress, and is excellent in dimension stability and the like. The display device includes: a supporting base including a polyimide film; and a gas barrier layer formed on the supporting base, in which the polyimide film has a transmittance of 80% or more in a wavelength region of from 440 nm to 780 nm, and a coefficient of thermal expansion of 15 ppm/K or less, and has a difference in coefficient of thermal expansion from the gas barrier layer of 10 ppm/K or less.

Abstract: Provided is a display device that can be made thin, lightweight, and flexible, has no problems of cracks and peeling caused by thermal stress, and is excellent in dimension stability and the like. The display device includes: a supporting base including a polyimide film; and a gas barrier layer formed on the supporting base, in which the polyimide film has a transmittance of 80% or more in a wavelength region of from 440 nm to 780 nm, and a coefficient of thermal expansion of 15 ppm/K or less, and has a difference in coefficient of thermal expansion from the gas barrier layer of 10 ppm/K or less.

Abstract: Provided is a display device that can be made thin, lightweight, and flexible, has no problems of cracks and peeling caused by thermal stress, and is excellent in dimension stability and the like. The display device includes: a supporting base including a polyimide film; and a gas barrier layer formed on the supporting base, in which the polyimide film has a transmittance of 80% or more in a wavelength region of from 440 nm to 780 nm, and a coefficient of thermal expansion of 15 ppm/K or less, and has a difference in coefficient of thermal expansion from the gas barrier layer of 10 ppm/K or less.

Abstract: Provided is a display device that can be made thin, lightweight, and flexible, has no problems of cracks and peeling caused by thermal stress, and is excellent in dimension stability and the like. The display device includes: a supporting base including a polyimide film; and a gas barrier layer formed on the supporting base, in which the polyimide film has a transmittance of 80% or more in a wavelength region of from 440 nm to 780 nm, and a coefficient of thermal expansion of 15 ppm/K or less, and has a difference in coefficient of thermal expansion from the gas barrier layer of 10 ppm/K or less.

Abstract: Provided is a display device that can be made thin, lightweight, and flexible, has no problems of cracks and peeling caused by thermal stress, and is excellent in dimension stability and the like. The display device includes: a supporting base including a polyimide film; and a gas barrier layer formed on the supporting base, in which the polyimide film has a transmittance of 80% or more in a wavelength region of from 440 nm to 780 nm, and a coefficient of thermal expansion of 15 ppm/K or less, and has a difference in coefficient of thermal expansion from the gas barrier layer of 10 ppm/K or less.

Abstract: Provided is a display device that can be made thin, lightweight, and flexible, has no problems of cracks and peeling caused by thermal stress, and is excellent in dimension stability and the like. The display device includes: a supporting base including a polyimide film; and a gas barrier layer formed on the supporting base, in which the polyimide film has a transmittance of 80% or more in a wavelength region of from 440 nm to 780 nm, and a coefficient of thermal expansion of 15 ppm/K or less, and has a difference in coefficient of thermal expansion from the gas barrier layer of 10 ppm/K or less.