Electrophotographic toner carrier with fluorinated polyimide coating - with good charging property, adhesion, abrasion resistance and solubility in polar solvent

摘要: Toner carrier for an electrophotographic printer has a coating of fluorinated polyimide resin (I) contg. 5-60 (wt.)% F atoms. Pref. solubility parameter 9-12. It pref. is based on units formula (II): R1 = tetravalent organic gp., (III) or deriv. this, which may be fluorinated; R2 divalent (IV) this: A alkene, -CO-, -O- combinatoin these; B -O-, -SO2 combination these. The contains over 20 (I). ADVANTAGE - prevents the toner sticking to and resistant abrasion, so that retains satisfactory electrical electrostatic charge properties long operating lifetime. Compared with PTFE, better in polar solvents, facilitates coating; higher adhesion core (e.g. Fe, ferrite, magnetite, etc.), attained just by drying at ca. 200 deg.C, rather than cure e.g. 300-400 reduced cost. No primer, acrylic epoxide resin, necessary.