FLUOROSILICONE FUSER ROLL COATING
Original Publication Date: 1986-Oct-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
In the fusing operation on electrostatographic reproducing device toner particles are elevated to a temperature at which the toner material coalesess and becomes tacky, flowing into the fibers or pores of the support members such as paper Typically this happens as the support member wlth the unfused toner image is passed through the nip formed between a roll pair It is important in the fusing process that no offset of the toner particles from the support to the fuser member takes place since such would lead to background on subsequent copies. A typical fuser roll would have a release surface of a condensation cured silicone rubber. It may also be advantageous to provide a release agent such as a polydimethyl silicone oil which is applied to the fuser roll to form an interface between the roll and the toner image providing a low surface energy easily parted layer However the typical silicone oils tend to migrate into or be absorbed by the silicone rubber thereby contributing to swelling of the silicone rubber roll leading to subsequent mechanical degradation of the €user roll Furthermore, this swelling may not be uniform in that silicone ail which is cyclically applied to the fuser roll 1s cont-nuously removed by the paper but not removed outside the paper path This results In a differential swelling and degradation between the areas Insrde and outside of the paper path For example, this further degradation outside the normal 11" paper path may be perceived when running 14" paper by the deposition on the paper of filler material used to increase the thermal conductivity or thermal stability of the sllicone rubber These difficulties can be minimized or overcome by employing an overcoabng on the silicone rubber fuser rolls which is made of a condensation cured fluorosilicone or a blend of fluorosilicone with dimethylsilicone which would swell less than the substrate silicone and thus would be less susceptible to degradation.