Fuser coating composition and method of manufacture

Abstract

The present teachings include a coating composition which includes a liquid, fluoropolymer particles, carbon nanotubes, and a dispersant. The dispersant has a thermal degradation temperature below the melting temperature of the fluoropolymer particles.

1 . A coating composition comprising a liquid, fluoropolymer particles, carbon nanotubes, and a dispersant, wherein the dispersant has a thermal degradation temperature below a melting temperature of the fluoropolymer particles. 
     
     
         2 . The coating composition of  claim 1 , wherein the liquid is selected from a group consisting of water, an alcohol, a C 5 -C 18  aliphatic hydrocarbon, a C 6 -C 18  aromatic hydrocarbon, an ether, an ester, a ketone, and an amide. 
     
     
         3 . A coating composition of  claim 1 , wherein the fluoropolymer particles are selected from the group consisting of polytetrafluoroethylene (PTFE); perfluoroalkoxy polymer resin (PFA); copolymer of tetrafluoroethylene (TFE) and hexafluoropropylene (HFP); copolymers of hexafluoropropylene (HFP) and vinylidene fluoride (VDF or VF2); terpolymers of tetrafluoroethylene (TFE), vinylidene fluoride (VDF), and hexafluoropropylene (HFP); and tetrapolymers of tetrafluoroethylene (TFE), vinylidene fluoride (VF2), and hexafluoropropylene (HFP). 
     
     
         4 . A coating composition of  claim 1 , wherein the carbon nanotubes are selected from the group consisting of single wall carbon nanotubes and multiple wall carbon nanotubes, and wherein the carbon nanotubes have an aspect ratio of at least about 10. 
     
     
         5 . A coating composition of  claim 1 , wherein the carbon nanotubes are present in an amount ranging from about 0.1 weight percent to about 50 weight percent based on the total weight of the carbon nanotubes and the fluoropolymer particles. 
     
     
         6 . A coating composition of  claim 1 , wherein the dispersant is selected from the group consisting of a polymeric amine, a polyethylene glycol, a polymeric acid, and a natural gum material. 
     
     
         7 . A coating composition of  claim 6 , wherein the dispersant is selected from a group consisting of a polyacrylic acid, a polymethacrylic acid, a polyethylene glycol containing surfactant, and a polyallylamine. 
     
     
         8 . A coating composition of  claim 1 , wherein the thermal degradation temperature of the dispersant is about 100° C. to about 280° C. 
     
     
         9 . A coating composition of  claim 1 , wherein the melting temperature of the fluoropolymer particles is from about 255° C. to about 360° C. 
     
     
         10 . A coating composition of  claim 1 , wherein the dispersant is present in an amount ranging from about 10 weight percent to about 50 weight percent of the total weight of the carbon nanotubes and the dispersant. 
     
     
         11 . A method of making a fuser member, comprising:
 obtaining a fuser member comprising a silicone resilient layer disposed on a substrate;   providing a coating dispersion comprising a liquid, fluoropolymer particles, carbon nanotubes, and a dispersant, wherein the dispersant has a thermal degradation temperature below a melting temperature of the fluoropolymer particles;   applying the coating dispersion over the silicone resilient layer to form a coating layer; and   heating the coating layer, including heating the coating layer to a temperature above the degradation temperature of the dispersant to allow removing the dispersant.   
     
     
         12 . A method of  claim 11 , wherein the liquid is selected from a group consisting of water, an alcohol, a C 5 -C 18  aliphatic hydrocarbon, a C 6 -C 18  aromatic hydrocarbon, an ether, an ester, a ketone, and an amide. 
     
     
         13 . A method of  claim 11 , wherein the fluoropolymer particles are selected from the group consisting of polytetrafluoroethylene (PTFE); perfluoroalkoxy polymer resin (PFA); copolymer of tetrafluoroethylene (TFE) and hexafluoropropylene (HFP); copolymers of hexafluoropropylene (HFP) and vinylidene fluoride (VDF or VF2); terpolymers of tetrafluoroethylene (TFE), vinylidene fluoride (VDF), and hexafluoropropylene (HFP); and tetrapolymers of tetrafluoroethylene (TFE), vinylidene fluoride (VF2), and hexafluoropropylene (HFP). 
     
     
         14 . A method of  claim 11 , wherein the carbon nanotubes are selected from the group consisting of single wall carbon nanotubes and multiple wall carbon nanotubes, and wherein the carbon nanotubes have an aspect ratio of at least about 10. 
     
     
         15 . A method of  claim 11 , wherein the dispersant is selected from a group consisting of a polyacrylic acid, a polymethacrylic acid, a polyethylene glycol containing surfactant, a polyallylamine, and a copolymer comprised thereof. 
     
     
         16 . A method of  claim 11 , wherein the release layer has an electrical surface resistivity of less than about 10 8  Ω/sq. 
     
     
         17 . A method of  claim 11 , wherein the step of applying the dispersion over the resilient layer to form a coated substrate comprises an application technique selected from the group consisting of spray coating, painting, dip coating, brush coating, roller coating, spin coating, casting, and flow coating. 
     
     
         18 . A method of  claim 11 , wherein the heating comprises a first step of heating the coating layer to a temperature above a degradation temperature of the dispersant to allow removing the dispersant; and
 a second step of heating the coating layer to a temperature above a melting temperature of the fluoropolymer particles to melt the fluoropolymer.   
     
     
         19 . A method of  claim 19 , wherein the degradation temperature ranges from about 150° C. to about 250° C. and the melting temperature for fluoropolymer ranges from 255° C. to about 360° C. 
     
     
         20 . A fuser member comprising:
 a substrate;   a silicone layer disposed on the substrate; and   an outer layer disposed on the silicone layer wherein the outer layer is formed from a coating dispersion comprised of a liquid, fluoropolymer particles, carbon nanotubes, and a thermally removable dispersant, wherein the thermally removable dispersant has a thermal degradation temperature below a melting temperature of the fluoropolymer particles.