Insulating material and electric machine winding and method for manufacturing the same

An insulating material comprising:

• an insulating layer comprising a flake-shaped inorganic insulating material and a thermosetting resin;
• a reinforcement layer comprising a reinforcing material and said thermosetting resin;
• a filler layer comprising a filler material and said thermosetting resin;
• wherein said filler layer is bonded to said reinforcement layer and said insulating layer;
• and said thermosetting ream is semi-cured for bonding said insulating layer, said reinforcement layer, and said filler layer;
• wherein the amount of resin in said insulating layer is 10 wt % to 25 wt % of the total weight of said insulating material;
• wherein the amount of resin in said filler layer is 10 wt % to 25 wt % of the total weight of said insulating material;
• and
• wherein the difference between said amount of resin in said insulating layer and said amount of resin in said filler layer is not more than 10 wt %.