NOVELTY - An aqueous solution composition of a polyimide precursor is obtained by reacting a tetracarboxylic dianhydride with a diamine having a solubility with respect to water of 0.1 g/L or more at 25 degrees C in the presence of imidazole by using water as reaction solvent.    USE - Manufacture of polyimide precursor aqueous solution composition (polyamic acid composition) useful for manufacturing aromatic-polyimide seamless belts and in binder resin compositions used in electrode mixture paste used for forming electrodes, and for manufacturing flexible devices (all claimed). The electrodes are used in lithium ion secondary batteries and electrical double layer capacitors. The flexible device includes LCDs, organic electroluminescent elements, electronic paper, and thin-film solar cells. The seamless belt is used as fixing belt or transfer belt in copiers, and in precision machinery and conveyors.    ADVANTAGE - The method enables easy and environmentally-friendly manufacture of polyimide precursor aqueous solution composition with reduced organic-solvent content, without requiring solvent other than water. The obtained composition has excellent heat resistance, mechanical strength, electrical property, and solvent resistance. The composition provides seamless belts having excellent toughness, heat resistance, and electrical resistance, and low linear expansion.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) manufacture of aromatic-polyimide seamless belt, which involves heat-processing a polyimide precursor aqueous solution obtained by dissolving polyamic acid consisting of a repeating unit of formula (I), obtained by reacting tetracarboxylic-acid component and diamine component, in an aqueous medium with 1.6 times mol or more imidazole with respect to dianhydride;    (2) binder resin composition containing polyamic acid dissolved in aqueous medium;    (3) electrode mixture paste containing an electrode active material and a binder resin composition;    (4) electrode obtained by applying the electrode mixture paste on a collector, heat-processing and removing solvent, and imidating;    (5) polyimide precursor resin composition obtained by dissolving polyamic acid in an aqueous medium; and    (6) manufacture of flexible device which is a display device or a light reception device, which involves applying the polyimide precursor resin composition on a carrier board, heat-processing and forming a solid-state polyimide resin film, forming a circuit on the polyimide resin film, and peeling the polyimide resin film from the carrier board.    A=tetravalent group obtained by removing carboxyl group from aromatic tetracarboxylic acid;and    B'=bivalent group obtained by removing amino group from aromatic diamine whose solubility with respect to water at 25 degrees C is 0.1 g/L or more.