FLAME-RETARDANT PHOTOCURABLE RESIN COMPOSITION, DRY FILM AND CURED PRODUCT OF THE SAME, AND PRINTED WIRING BOARD USING THE COMPOSITION, DRY FILM OR CURED PRODUCT

摘要

Disclosed is a flame-retardant photocurable resin composition which has a halogen-free composition and thus places little burden on the environment.  The flame-retardant photocurable resin composition has excellent flame retardancy and storage stability, and is capable of forming a cured coating film having excellent flexibility.  A dry film and cured product of the composition, and a printed wiring board provided with a flame-retardant cured coating film such as a solder resist obtained by using the composition, dry film or cured product are also disclosed. The flame-retardant photocurable resin composition contains (A) a phosphazene compound which is in a liquid state at room temperature, (B) a carboxyl group-containing resin, and (C) a photopolymerization initiator.  Preferably, the carboxyl group-containing resin (B) is a carboxyl group-containing polyurethane resin.  Preferably, the flame-retardant photocurable resin composition additionally contains (D) a photopolymerizable monomer or (E) a thermosetting resin.  The flame-retardant photocurable resin composition, particularly a flame-retardant photocurable/thermosetting resin composition containing the thermosetting resin (E) can be suitably used as a solder resist.