Polyimide-based block copolymer and polyimide-based film comprising the same

A polyimide-based block copolymer including

• a first repeating unit represented by Chemical Formula 1 and a second repeating unit represented by Chemical Formula 2,
• wherein the copolymer has properties such that, when incorporated in a film having a thickness of 20 μm all to 80 μm, the film has 3% or less haze, and
• wherein the copolymer has a degree of branching of 1 to 100:
• in Chemical Formula 1,
• each R1 is the same as or different from each other in each repeating unit, and each is independently a single bond, —O—, —S—, —C(═O)—, —CH(OH)—, —S(═O)2—, —Si(CH3)2—, —(CH2)p—(wherein 1≤p≤10), —(CF2)q— (wherein 1≤q≤10), —C(CH3)2—, —C(CF3)2—, —C(═O)NH—, or a C6 to C30 divalent aromatic organic group;
• each R2 is independently —H, —F, —Cl, —Br, —I, —CF3, —CCl3, —CBr3, —CI3, —NO2, —CN, —COCH3, —CO2C2H5, a silyl group containing three C1 to C10 aliphatic organic groups, a C1 to C10 aliphatic organic group, or a C6 to C20 aromatic organic group;
• n1 and m1 are independently an integer of 0 to 3;
• each Y1 is the same as or different from each other in each repeating unit, and each independently comprises a divalent C6 to C30 aromatic organic group, and the aromatic organic group exists alone, or two or more aromatic organic groups are bonded to each other to form a divalent condensed ring, or two or more aromatic organic groups are linked by a single bond, a fluorenylene group, —O—, —S—, —C(═O)—, —CH(OH)—, —S(═O)2—, —Si(CH3)2—, —(CH2)p— (wherein 1≤p≤10), —(CF2)q— (wherein 1≤q≤10), —C(CH3)2—, —C(CF3)2—, —C(═O)NH—;
• E1, E2, and E3 are independently a single bond or —NH—;
• and
• each Z1 is the same as or different from each other in each repeating unit, and each is independently a trivalent linking group derived from at least one compound selected from the group consisting of triacyl halide, tricarboxylic acid, and tricarboxylate,
• [Chemical Formula 2]
• *E4-Y2-E5-Z2-E6*
• in Chemical Formula 2,
• each Y2 is the same as or different from each other in each repeating unit, and each independently comprises a C6 to C30 divalent aromatic organic group, and the aromatic organic group exists alone, or two or more aromatic organic groups are bonded to each other to form a divalent condensed ring, or two or more aromatic organic groups are linked by a single bond, a fluorenylene group, —O—, —S—, —C(═O)—, —CH(OH)—, —S(═O)2—, —Si(CH3)2—, —(CH2)p— (wherein 1≤p≤10), —(CF2)q— (wherein 1≤q≤10), —C(CH3)2—, —C(CF3)2—, —C(═O)NH—;
• E4, E5, and E6 are independently a single bond or —NH—;
• and
• each Z2 is the same as or different from each other in each repeating unit, and each is independently a divalent linking group derived from at least one compound selected from the group consisting of diacyl halide, dicarboxylic acid, and dicarboxylate in the form of —C(═O)-A-C(═O)—,
• wherein A of Z2 is a C6 to C20 divalent aromatic organic group, a C4 to C20 divalent heteroaromatic organic group, or a C6 to C20 divalent alicyclic organic group, and two of —C(═O)— are bonded at a para position with respect to A.