Varying fluoroelastomer cure across the roller to maximize fuser roller life

Abstract

In accordance with the invention, there are image forming apparatus, fuser members, and methods of making fuser members. The method of making a fuser member can include providing a substrate having a longitudinal axis, providing a first flow coating solution including a fluoroelastomer polymer, and providing a second flow coating solution including a crosslinking agent. The method can also include mixing the first flow coating solution and the second flow coating solution to form a third flow coating solution and forming a continuous fluoroelastomer layer over a surface of the substrate by applying the third flow coating solution onto the substrate in a spiral pattern, wherein the crosslinking agent concentration can be varied along the longitudinal axis by changing the ratio of the first flow coating solution and the second flow coating solution in the third flow coating solution.

1 . A method of making a fuser member comprising:
 providing a substrate having a longitudinal axis;   providing a first flow coating solution comprising a fluoroelastomer polymer;   providing a second flow coating solution comprising a crosslinking agent;
 mixing the first flow coating solution and the second flow coating solution to form a third flow coating solution; and 
 forming a continuous fluoroelastomer layer over a surface of the substrate by applying the third flow coating solution onto the substrate from an applicator in a spiral pattern by rotating the substrate in a horizontal position about the longitudinal axis and moving the applicator along the longitudinal axis, 
 wherein the crosslinking agent concentration is varied along the longitudinal axis by changing the ratio of the first flow coating solution and the second flow coating solution in the third flow coating solution. 
   
     
     
         2 . The method of  claim 1 , wherein the step of providing a first flow coating solution comprising a fluoroelastomer polymer comprises providing a first flow coating solution comprising fluoroelastomer polymer selected from the group consisting of copolymers of vinylidene fluoride, hexafluoropropylene, and tetrafluorothylene; and terpolymers of vinylidene fluoride, hexafluoropropylene, and tetrafluorothylene. 
     
     
         3 . The method of  claim 1 , wherein the step of providing a second flow coating solution comprising a crosslinking agent comprises providing a second flow coating solution comprising a bisphenol and a quarternary phosphonium salt. 
     
     
         4 . The method of  claim 1 , wherein the step of forming a continuous fluoroelastomer layer over a surface of the substrate comprises:
 forming a stain resistance region; and   forming one or more wear resistance regions.   
     
     
         5 . The method of  claim 4  further comprising mixing the first flow coating solution and the second flow coating solution to form a third flow coating solution such that the crosslinking agent concentration in the stain resistance region is higher than the crosslinking agent concentration in the one or more wear resistance regions. 
     
     
         6 . The method of  claim 4  further comprising curing the continuous fluoroelastomer layer, such that the crosslinking agent to fluoroelastomer polymer ratio is from about 0.03 to about 0.04 in the wear resistance region after curing. 
     
     
         7 . The method of  claim 4  further comprising curing the continuous fluoroelastomer layer, such that the crosslinking agent to fluoroelastomer polymer ratio is from about 0.09 to about 0.1 in the stain resistant region after curing. 
     
     
         8 . A method of making a fuser member comprising:
 providing a substrate having a longitudinal axis;   
       providing a first flow coating solution comprising a fluoroelastomer polymer and a first amount of a crosslinking agent; 
       providing a second flow coating solution comprising the fluoroelastomer polymer and a second amount of the crosslinking agent; 
       mixing the first flow coating solution and the second flow coating solution to form a third flow coating solution; and 
       forming a continuous fluoroelastomer layer over a surface of the substrate by applying the third flow coating solution onto the substrate from an applicator in a spiral pattern by rotating the substrate in a horizontal position about the longitudinal axis and moving the applicator along the longitudinal axis, 
       wherein the crosslinking agent concentration is varied along the longitudinal axis by changing the ratio of the first flow coating solution and the second flow coating solution in the third flow coating solution. 
     
     
         9 . The method of  claim 8 , wherein the step of providing a first flow coating solution comprising a fluoroelastomer polymer comprises providing a first flow coating solution comprising fluoroelastomer polymer selected from the group consisting of copolymers of vinylidene fluoride, hexafluoropropylene, and tetrafluorothylene; and terpolymers of vinylidene fluoride, hexafluoropropylene, and tetrafluorothylene. 
     
     
         10 . The method of  claim 8 , wherein the step of providing a second flow coating solution comprising a crosslinking agent comprises providing a second flow coating solution comprising a bisphenol and a quarternary phosphonium salt. 
     
     
         11 . The method of  claim 8 , wherein the step of forming a continuous fluoroelastomer layer over a surface of the substrate comprises:
 forming a stain resistance region; and   forming one or more wear resistance regions.   
     
     
         12 . The method of  claim 11  further comprising mixing the first flow coating solution and the second flow coating solution to form a third flow coating solution such that the crosslinking agent concentration in the stain resistance region is higher than the crosslinking agent concentration in the one or more wear resistance regions. 
     
     
         13 . The method of  claim 11  further comprising curing the continuous fluoroelastomer layer, such that the crosslinking agent to fluoroelastomer polymer ratio is from about 0.03 to about 0.04 in the wear resistance region after curing. 
     
     
         14 . The method of  claim 11  further comprising curing the continuous fluoroelastomer layer, such that the crosslinking agent to fluoroelastomer polymer ratio is from about 0.09 to about 0.1 in the stain resistant region after curing.