TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The solvent is a polar solvent or a mixed solvent comprising one or more polar solvents. The terminal carboxyl group and terminal amine group of the polyamide are end-capped. The amount of diamine containing a free carboxylic acid group in the polyamide is less than 1 mole% of the total of the polyamide. The aromatic copolyamide comprises at least two repeat units, where at least one repeat unit(s) is formed by reacting an aromatic diamine comprising 4,4'-diamino-2,2'-bistrifluoromethylbenzidine, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis(3-fluoro-4-aminophenyl)fluorene, 4,4'-diamino-2,2'-bistrifluoromethoxylbenzidine, 4,4'-diamino-2,2'-bistrifluoromethyldiphenyl ether, bis-(4-amino-2-trifluoromethylphenyloxyl) benzene, and bis-(4-amino-2-trifluoromethylphenyloxyl)biphenyl with at least one aromatic diacid dichloride. The solvent is cresol, N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, dimethylsulfoxide, or butyl cellosolve, a mixed solvent comprising at least one of cresol, N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, dimethylsulfoxide, Butyl cellosolve (RTM: Acetate solvent), methyl cellosolve, ethyl cellosolve, ethyleneglycol monobutylether, propyleneglycol monobutylether, diethyleneglycol monobutylether, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, and/or N,N-dimethylformamide , or a mixed solvent comprising at least one of polar solvent. The aromatic diacid dichloride is terephthaloyl dichloride, isophthaloyl dichloride, 2,6-naphthaloyl dichloride, or 4,4,-biphenyldicarbonyl dichloride. The reagent is organic neutralizing reagent and propylene oxide. The solvent is an organic and/or an inorganic solvent. The diamines contains one or more free carboxylic acid groups, such that the amount of diamine containing a carboxylic acid group is greater than 1 mole% and less than 30 mole% of the total diamine mixture. Preferred Process: The film is produced in the absence of inorganic salt. The process of forming display element using the solution, comprises (a2) applying the solution of an aromatic copolyamide onto a base, (b2) forming a polyamide film on the base after the applying step (a2), and (c2) forming the display element, the optical element or the illumination element on the surface of polyamide film. The reagent is added to the mixture before or during the reacting step (c). The reaction of the reagent with the hydrochloric acid forms a volatile product. The process of manufacturing solution of aromatic copolyamide, further comprises end-capping for one or both of the terminal carboxyl group and terminal amine group of the polyamide. EXAMPLE - 3.2024 g of 4,4'-Diamino-2,2'-bistrifluoromethylbenzidine and dried 45 ml of N,N-dimethylacetamide were added to a 250 ml, three necked, round bottom flask, equipped with a mechanical stirrer, a nitrogen inlet and an outlet. 0.6395 g of Isophthaloyl dichloride was added to the solution at room temperature under nitrogen, and the flask wall was washed with 1.5 ml of N,N-dimethylacetamide. After 15 minutes, 1.4211 g of terephthaloyl dichloride was added to the solution, and the flask wall was again washed with 1.5 ml of N,N-dimethylacetamide. The viscosity of the solution was increased, and after adding 1.4 g of propylene oxide, gel was broken up under stirring to form a viscous, homogenous solution. After stirring at room temperature for another 4 hours, the resulting copolymer solution was directly casted into the film.