Crosslinking agent, curable composition, prepreg, multilayer body, metal clad laminate, wiring board, and novel organophosphorus compounds

Abstract

This invention provides a novel organophosphorus compound, a novel crosslinking agent, a curable composition, a prepreg, a laminate, a metal-coated laminate, and a wiring substrate, all of which can impart excellent electrical properties, flame retardancy, and heat resistance. The crosslinking agent of this invention is represented by the following formula (1). In formula (1), R1 represents a hydrocarbon group that may contain heteroatoms, L independently represents a single bond, an oxygen atom, or a divalent hydrocarbon group that may contain heteroatoms, n is 2 or 3, the benzene ring may independently have substituents, and the combination of each component satisfies a specific relationship.