| abstract |
A novel heat-fusible copolymer which has excellent mechanical strength, radiation resistance, chemical resistance, low-temperature characteristics, heat resistance, processability, and adhesion and can simultaneously meet requirements for low water absorption and excellent dielectric properties; and film, powder, laminated film, heat-fusible film for covering wires, laminated heat insulator, electronic module, and capacitor, each produced from a thermoplastic polyimide resin composed mainly of the above copolymer and suitable for use as electronic components, materials for electronic circuit components capable of coping with a need for high-density packaging and the like. The copolymer has a combination of a glass transition point of 100 to 250 °C, a water absorption of not more than 1 %, and a permittivity of not more than 3 and is represented by general formula (I), wherein Ar 1 represents a tetravalant organic group; Ar 2 represents a divalent organic group; R represents a divalent organic group; X is a trivalent bonding group; m and n are each an integer of 0 or more, provided that the sum of m and n is 1 or more; and 1 is an integer of 1 or more. |