Patent ID: 7973243

Claim:
A coil insulator of an electrical rotating machine used as a main insulator for insulating a bundle of conductors formed of a plurality of insulated wires to form an armature coil provided in a slot of a rotor core or a stator core of an electrical rotating machine, wherein the coil insulator comprises: a mica layer including at least one of a peeled-off mica and a composite mica; a woven- or unwoven cloth formed of at least one of inorganic and organic materials; hexagonal crystal boron nitride particles having a graphitization index of 1.8 or higher; and thermosetting polymer organic resin for forming an integrated configuration of the mica layer and the hexagonal crystal boron nitride particles, and wherein the hexagonal crystal boron nitride particles is oriented in a longitudinal direction of the armature coil.