Fixing member and heat fixing apparatus
A fixing member for electrophotography having an endless shape has a base layer having an endless shape, and an elastic layer on the outer circumferential surface of the base layer. The elastic layer includes a silicone rubber and a filler dispersed in the silicone rubber. The total amount of the filler compounded in the elastic layer is 30 vol % or less based on the total volume of the elastic layer. The elastic layer satisfies the relation of λtd>λmd>λnd. λtd is a thermal conductivity of the elastic layer in the circumferential direction, λnd is a thermal conductivity of the elastic layer in the thickness direction, and λmd, is a thermal conductivity of the elastic layer in the longitudinal direction. λtd is 2.0 W/(m·K) or more, and λnd is 1.3 W/(m·K) or more.
1. A fixing member for electrophotography having an endless shape comprising:
a base layer having an endless shape, and
an elastic layer on an outer circumferential surface of the base layer,
the elastic layer including a silicone rubber and a filler dispersed in the silicone rubber,
wherein a content of the filler in the elastic layer is 30 vol % or less with respect to a volume of the elastic layer, wherein
the elastic layer satisfies following relation:
λ td>λmd>λnd,
where λtd is a thermal conductivity of the elastic layer in a circumferential direction, λnd is a thermal conductivity of the elastic layer in a thickness direction, and λmd is a thermal conductivity of the elastic layer in a longitudinal direction, and
wherein λtd is 2.0 W/(m·K) or more, and λnd is 1.3 W/(m·K) or more.
2. The fixing member according to claim 1 , further comprising a surface layer on an outer circumferential surface of the elastic layer.
3. The fixing member according to claim 1 , wherein the filler comprises hexagonal boron nitride.
4. The fixing member according to claim 3 , wherein a content of the hexagonal boron nitride is 20 vol % to 25 vol % based on a volume of the elastic layer.
5. The fixing member according to claim 1 , wherein the elastic layer has an elastic modulus of 0.20 MPa to 1.20 MPa.
6. The fixing member according to claim 1 , wherein the fixing member is a fixing belt having an inner diameter of 20 mm to 130 mm.
7. A heat fixing apparatus comprising a heating member and a pressurizing member disposed opposed to the heating member,
wherein the heating member is a fixing member, the fixing member comprising:
a base layer having an endless shape, and
an elastic layer on an outer circumferential surface of the base layer,
wherein the elastic layer includes a silicone rubber and a filler dispersed in the silicone rubber,
wherein a content of the filler in the elastic layer is 30 vol % or less based on a volume of the elastic layer,
wherein the elastic layer satisfies following relation:
λ td>λmd>λnd,
where λtd is a thermal conductivity of the elastic layer in a circumferential direction, λnd is a thermal conductivity of the elastic layer in a thickness direction, and λmd is a thermal conductivity of the elastic layer in a longitudinal direction, and wherein λtd is 2.0 W/(m·K) or more, and λnd is 1.3 W/(m·K) or more.
8. A heat fixing apparatus comprising a heating member, a pressurizing member disposed opposed to the heating member, and a heater for heating the heating member, wherein the heating member is the fixing member according to claim 6 , and the heater is disposed in contact with an inner circumferential surface of a substrate of the fixing member.