Epoxy-modified polyimide, photosensitive composition, coverlay film, solder resist, and printed wiring board using the epoxy-modified polyimide

A method of producing an epoxy-modified polyimide comprising:

• reacting polyimide represented by the general formula (2):
• wherein R10 is a tetravalent organic group;
• R11 is a divalent organic group containing at least one of a carboxy group and a hydroxy group;
• R12 is a divalent organic group;
• m is an integer of one or more;
• and n is an integer of 0 or more, with a compound selected from the group consisting of an epoxy compound containing at least two epoxy groups, a compound containing an epoxy group and a carbon—carbon double bond, and a compound containing an epoxy group and a carbon—carbon triple bond.

A photosensitive composition, comprising:

• (A) an epoxy modified polyimide having a structural unit represented by the general formula (1):
• wherein R1 is a tetravalent organic group;
• R3 is a divalent organic group;
• and R2 is a divalent organic group containing 1 to 4 organic groups selected from the group consisting of:
• wherein R4 is a monovalent organic group containing at least one selected from the group consisting of an epoxy group, a carbon—carbon double bond, and a carbon—carbon triple bond;
• m is an integer of 1 or more;
• and
• n is an integer of 0 or more, and
• (B) at least one of a photoreaction initiator and a sensitizer.

A photosensitive composition comprising:

• (A) an epoxy modified polyimide having a structural unit represented by at least the general formula (1):
• wherein R1 is a tetravalent organic group;
• R3 is a divalent organic group;
• and R2 is a divalent organic group containing 1 to 4 organic groups selected from the group consisting of:
• wherein R4 is a monovalent organic group containing at least one selected from the group consisting of an epoxy group, a carbon—carbon double bond, and a carbon—carbon triple bond;
• m is an integer of 1 or more;
• and
• n is an integer of 0 or more,
• (B) at least one of a photoreaction initiator and a sensitizer, and
• (C) one of a reactive monomer or an oligomer containing a reactive carbon—carbon unsaturated bond.