Electrophotographic member and heat fixing device

A heat fixing device comprising:

• a heating member;
• and
• a pressurizing member arranged to face the heating member,
• the heating member being an electrophotographic member,
• wherein the electrophotographic member
• has an endless shape, and
• includes a substrate and an elastic layer on an outer peripheral surface of the substrate,
• wherein the elastic layer contains a silicone rubber and metal silicon fillers dispersed in the silicone rubber,
• an average of area ratios of the fillers in respective first binarized images each having a size measuring 150 μm by 100 μm at 5 arbitrary sites of a first section in thickness-peripheral directions of the elastic layer, and
• an average of area ratios of the fillers in respective second binarized images each having a size measuring 150 μm by 100 μm at 5 arbitrary sites of a second section in thickness-axial directions of the elastic layer is 42% or less, and wherein
• the elastic layer has λ of 1.30 W/(m·K) or more, where λ is a thermal conductivity of the elastic layer in a thickness direction thereof, and
• the elastic layer has ρv of 9.0 LOG Ω·cm or more, where ρv is a common logarithm value of a volume resistivity thereof.