Chemically Produced Toner Containing a Binary Polyester Binder

Abstract

The fuser roller is commonly used in electrophotograhic machines such as copiers, laser printers and multifunctional printers to fix toner image on paper. For improving printing speeds, image gloss and energy consumptions, an increasing number of printers are designed to adopt polyester toner. Polyester toner, with its low fusing temperatures, is aimed to accommodate fuser rollers operated at low temperatures to reduce energy consumption. Although polyester toner has the above advantages, low fusing temperatures on the other hand can cause hot-offset defects on the fuser roller. This paper reports the study of chemically produced toner (CPT) consisting of a binary polyester binder. The toner was prepared by phase-separation/aggregation (PSA) method. It was found a balance of low-temperature fixing and anti-offset characteristics can be achieved by incorporating a binary polymer mixture of low- and high-molecular weight polyesters. The addition of wax was also used to provide an option to tune the fixing and anti-offset characteristics. Wax content, however, was found to exhibit some threshold value, above which wax tends to separate from the toner and the resultant wax leaks can contaminate associated printer parts to cause streaking defects.