Abstract: An addition type imide resin prepolymer is obtained by a reaction of unsaturated bisimide of 1.0 mol to diamine of 0.25 to 0.43 mol and an addition of polyamine having three or more benzene rings. The prepolymer is thereby made to contain substantially no unreacted diamine component which affects human body of operators, and to have remarkably excellent heat resistance and adhesive properties, while effective to restrain a production of any component of a molecular weight exceeding 15,000.

Abstract: A process for producing an unsaturated dicarboxylic acid imide compound of formula (I): ##STR1## wherein D represents a divalent organic group having at least one carbon/carbon double bond; R.sup.1 represents an n-valent organic group having at least one carbon atom; and n is an integer of 1 or above, which comprises reacting an unsaturated amide acid compound of formula (II): ##STR2## wherein D, R.sup.1, and n are as defined above, with an orthoester of formula (III): ##STR3## wherein R.sup.2 and R.sup.3, which may be the same or different, each represents a monovalent organic group having at least one carbon atom, to form an unsaturated dicarboxylic acid amide acid ester compound of formula (IV): ##STR4## wherein D, R.sup.1, R.sup.3, and n are as defined above, and then imidating the compound of formula (IV).