Abstract

During xerographic printing processes, the electric charge properties of the paper surface are essential to obtain effective toner transfer and high image quality. Surface and volume resistance are indispensable to the accumulation of the surface charge and different resistance values generate different electrical fields with optical drum, and have a significant effect on toner transfer efficiency. In this paper, surface sizing was investigated to improve the surface properties for better toner transfer and image quality. Styrene acrylate emulsion (SAE) latex was successfully synthesized and fully characterized with a Fourier transform infrared (FT-IR) spectrometer, a laser particle analyzer and a scanning electron microscope (SEM). The results showed that under the conditions of emulsifier dosage at 3 wt%, initiator concentration at 0.5 wt% and the reaction temperature at 80°C, the monomer conversion can reach 80%. The effects of various factors including initiator dosage, emulsifier dosage and monomer ratio on the sizing performance were studied. The effects of different ratios of SAE to starch on surface and volume resistance of paper were also systematically investigated. The differences in electric properties of various paper samples were quantified and their influence on paper-toner adhesion and print quality was clarified. Relationships between electrical properties of paper and paper-toner adhesion force, and thus print quality were established. Strategies to improve printing performance through effective control of paper electrical properties were also developed. It is concluded that the best printing quality and toner adhesion were achieved when the ratio of SAE to starch is between 1:10 and 2:10.