Abstract: A coil for a rotating electrical machine, the coil comprising a coil conductor and an insulating layer that is disposed around an outer periphery of the coil conductor, the insulating layer comprising a mica tape, the mica tape comprising a mica layer including mica and a backing layer including a backing material, the mica comprising mica pieces having a particle size of 2.8 mm or more, as measured by a JIS standard sieve, at a proportion of less than 45% by mass of a total of the mica pieces that are obtained from the mica layer being separated from the backing layer.

Abstract: A coil for a rotary electrical machine comprising a coil conductor and an insulation layer disposed around an outer periphery of the coil conductor, the insulation layer comprising a cured product of a mica tape, the mica tape comprising mica, a reinforcing member and a thermosetting resin, and having a reaction heat generated by a curing reaction of the thermosetting resin, as measured by differential scanning calorimetry (DSC), of ?270 J/g or less.

Abstract: A pretreating solution for electroless plating comprising sulfuric acid, a halide, an organic acid and water as a diluent functions as an adhesion accelerating agent without generating etching corrosion, has a long life and provides excellent adhesiveness of plated copper to both glass cloth and substrate resins.

Abstract: An electroless copper plating solution comprising a cupric salt, a copper complexing agent, a reducing agent, a pH adjustor, L-arginine and at least one of .alpha.,.alpha.'-dipyridyl and a cyano complex compound can give plated films high in ductility and adhesive strength and excellent in mechanical properties.