Patent ID: 7078477

Claim:
A process for producing a solvent-soluble polyimide, comprising a step of polycondensing at least one tetracarboxylic acid component with at least one diamine component in a solvent in the presence of a tertiary amine as a catalyst and being in addition to the solvent, said step of polycondensing being performed with a reaction mixture consisting essentially of said at least one tetracarboxylic acid component, said at least one diamine component, said solvent and said tertiary amine, said at least one tetracarboxylic acid component being selected from the group consisting of tetracarboxylic dianhydrides represented by the following formula 1: wherein R is a tetravalent group derived from a C 2 to C 12 compound that is selected from the group consisting of straight-chain hydrocarbons, branched hydrocarbons, alicyclic hydrocarbons, bialicyclic hydrocarbons, and spiro compounds optionally having oxygen constituting a spiro ring, and tetracarboxylic acids and their derivatives represented by the following formula 2: wherein R is the same as defined in the formula 1 and Y 4 to V 4 are the same or different and each independently hydrogen or a C 1 to C 8 hydrocarbon group.