| abstract |
(57) Abstract: A varnish showing good flame retardancy, excellent electrical insulation, and capable of forming an electrical insulating layer with little change in dielectric constant, an electrical insulating film obtained using the same, and a laminate having the same. Provide body. A curable varnish containing an insulating polymer, a curing agent, a flame retardant, and an organic solvent, wherein (1) the flame retardant is obtained by subjecting a flame retardant to a surface treatment with a coupling agent. (2) A varnish having a secondary particle size of 30 μm or less of particles present in the varnish is applied to a substrate, dried, and cured to form an electric insulating film, thereby obtaining a multilayer circuit board. In addition, the varnish, after contacting the flame retardant slurry obtained from contacting the flame retardant imparting agent and the coupling agent with a porous material with a flame retardant slurry comprising an organic solvent, the insulating polymer and In the case where the varnish is obtained by mixing with a curing agent, an increase in the viscosity of the varnish can be suppressed, and an electric insulating film having excellent flatness even after long-term storage can be obtained. |