Display device, method for manufacturing same, polyimide film for display device supporting bases, and method for producing polyimide film for display device supporting bases

A display device, comprising:

• a supporting base comprising a polyimide film;
• a gas barrier layer formed on the supporting base and to be brought into contact with the supporting base;
• and
• a stress relaxation layer formed on the gas barrier layer,
• wherein the polyimide him has a transmittance of 80% or more in a wavelength region of from 440 nm to 780 nm, and a transmittance of 80% or less at 400 nm, a retardation in an in-plane direction of 10 nm or less, 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,
• wherein the gas barrier layer comprises one kind or two or more kinds selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon oxycarbide, silicon carbonitride, and aluminum oxide, and the gas barrier layer has a coefficient of thermal expansion of from 0 ppm/K to 10 ppm/K,
• wherein the polyimide film comprising a single polyimide layer or a plurality of polyimide layers comprising a main polyimide layer containing polyimide having a structural unit represented by the following general formula (4) and a structural unit represented by the following general formula (5) at a molar ratio “(4):(5)” of from 50:50 to 100:0.