Polyamideimide resin, adhesive agent, material for flexible substrate, flexible laminate, and flexible print wiring board

A polyamide-imide resin obtained by a process comprising the step of reacting a diimide dicarboxylic acid with an aromatic diisocyanate, and further reacting therewith a further compound selected from the group consisting of phthalic acid, trimellitic acid, maleic acid, biphthalic acid, naphthalene dicarboxylic acid, aminonaphthalene acid, aminobenzoic acid, diaminonaphthalene, diaminobenzoic acid, phenyldiamine and derivatives thereof,

• wherein said diimide dicarboxylic acid contains 40 mol % or more of a compound represented by the following general formula (1),
• 20 mol % or more of a compound represented by the following general formula (2), and
• a compound produced by the reaction of an alicyclic diamine and a trimellitic anhydride,
• wherein n1 is an integer of 1 to 100 in the formula (1), and R1 and R2 each independently represent a divalent organic group, R3 and R4 each independently represent a C1-20 alkyl group or a C6-18 aryl group, a plurality of R3 and R4 in the same molecule may be the same or different, and n2 is an integer of 1 to 50 in the formula (2),
• wherein the polyamide-imide resin has at least one terminal functional group selected from the group consisting of a carboxyl group and an amino group, and
• wherein the polyamide-imide resin has a carboxylic acid equivalent of 3000 to 15000 g/eq or an amine equivalent of 3000 to 15000 g/eq.