Sheet-form insulating varnish and producing method therefor, electrical device, and rotary electric machine

A sheet-form insulating varnish to be disposed in a gap between insulation target members, at least a part of the gap having a fixed dimension, formed from a thermosetting resin composition in an uncured or semi-cured state, in a sheet form with predetermined film thickness,

• wherein the thermosetting resin composition contains:
• a thermosetting resin (A) that is in solid form at 25° C.;
• a thermosetting resin (B) that is in liquid form at 25° C.;
• a latent curing agent that is unreactive at 60° C. or lower;
• and
• an inorganic filler having a maximum particle diameter smaller than the dimension of the gap and having an average particle diameter smaller than 0.5 times the dimension of the gap, wherein
• an amount of the thermosetting resin (A) per a total of 100 parts by mass of the thermosetting resin (A) and the thermosetting resin (B) is in a range of 30 parts by mass to 70 parts by mass, and
• a volume ratio of the inorganic filler to an entirety of the composition is not higher than 50%,
• wherein the sheet-form insulating varnish has a compression rate that reduces the film thickness by at least 10% under a pressure of 25 MPa at 25° C.,
• wherein the sheet-form insulating varnish satisfies at least one of:
• (A) the sheet-form insulating varnish has, at 25° C., a storage shear modulus that is in a range of 1.0×103 Pa to 5.0×104 Pa, and a smallest value of the storage shear modulus is present in a range of 80° C. to 150° C. and is in a range of 10 Pa to 2.0×103 Pa, or
• (B) the sheet-form insulating varnish has, at 25° C., a complex viscosity that is in a range of 6.0×102 Pa·s to 1.0×104 Pa·s, and a smallest value of the complex viscosity is present in a range of 80° C. to 150° C. and is not greater than 5.0×102 Pa·s.