Polyamic acid, polyamic acid solution, polyimide, polyimide film, laminate and flexible device, and method for producing polyimide film

A polyamic acid which is a polyaddition reaction product of a diamine and a tetracarboxylic dianhydride,

• wherein:
• the diamine comprises 2,2′-bistrifluoromethylbenzidine,
• the tetracarboxylic dianhydride comprises 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride,
• the 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride is comprised in an amount of 0.5 mol % or more and 10 mol % or less based on a total amount of the tetracarboxylic anhydride,
• the tetracarboxylic dianhydride further comprises pyromellitic anhydride, and
• the pyromellitic anhydride is comprised in an amount of 10 mol % or more and 50 mol % or less based on the total amount of the tetracarboxylic anhydrides.

A polyimide which is a polycondensation reaction product of a diamine and tetracarboxylic dianhydride,

• wherein:
• the diamine comprises 2,2′-bistrifluoromethylbenzidine,
• the tetracarboxylic dianhydride comprises 3,3′,4,4′-biphenyltetracarboxylic dianhydride, and 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride,
• the 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride is comprised in an amount of 0.5 mol % or more and 10 mol % or less based on a total amount of the tetracarboxylic anhydrides, and
• an amount of the 2,2′-bistrifluoromethylbenzidine based on a total amount of the diamine is 90 mol % or more.

A polyimide which is a polycondensation reaction product of a diamine and tetracarboxylic dianhydride,

• wherein:
• the diamine comprises 2,2′-bistrifluoromethylbenzidine,
• the tetracarboxylic dianhydride comprises 3,3′,4,4′-biphenyltetracarboxylic dianhydride, and 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride,
• the 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride is comprised in an amount of 0.5 mol % or more and 10 mol % or less based on a total amount of the tetracarboxylic anhydrides,
• the tetracarboxylic dianhydride further comprises pyromellitic anhydride, and
• the pyromellitic anhydride is comprised in an amount of 10 mol % or more and 50 mol % or less based on the total amount of the tetracarboxylic anhydrides.