Heating element, process of producing heating element, heating device and image forming apparatus

Abstract

An endless-belt shaped heating element made of a heat resisting resin in which stainless-steel fibers subjected to annealing treatment is dispersed is prepared. The heating element is adopted as a heating belt of a fixing device of an image forming apparatus.

What is claimed is: 
     
         1 . A heating element comprising:
 an article comprising a heat-resistant resin; and   annealed stainless-steel fibers dispersed in the article.   
     
     
         2 . The heating element according to  claim 1 , wherein
 the heating element satisfies Expression (1):
   {( L 1− L 0)/ L 0}≦|0.0002|  (1)
 
   where L 0  represents a size of the heating element in an initial state, and L 1  represents a size of the heating element which is left under an environment of 200° C. for one week.   
     
     
         3 . The heating element according to  claim 1 , wherein the heating element comprises 10 to 60 volume percent of the annealed stainless-steel fibers. 
     
     
         4 . The heating element according to  claim 1 , wherein the heating element has a volume resistivity of 0.08×10 −4  to 10.00×10 −4  Ωcm. 
     
     
         5 . The heating element according to  claim 1 , wherein the heating element satisfies Expression (2):
   1≦(ρ s 1/ρ s 0)≦1.03   (2)
   where ρs 0  represents a resistance value (Ω) of the heating element in an initial state, and psi represents a resistance value (Ω) of the heating element which is left under an environment of 180° C. and 50 RH % for one week.   
     
     
         6 . A heating device comprising:
 a heat generation member having a sheet shape or an endless shape;   a fixing roller disposed inside the heat generation member, and configured to make contact with a portion of an inner periphery surface of the heat generation member;   a pressure roller disposed outside the heat generation member, and configured to press an outer peripheral surface of the heat generation member toward the fixing roller; and   a power supply device configured to supply electricity to the heat generation member, wherein   the heat generation member is the heating element according to  claim 1  which has a sheet shape or an endless shape.   
     
     
         7 . An image forming apparatus comprising a fixing device for applying heat and pressure to a recording medium to fix an unfixed toner image formed on the recording medium by an electrophotographic process on the recording medium, wherein
 the fixing device is the heating device according to  claim 6 .