Toner to develop electrostatic latent images

摘要

A toner to develop electrostatic latent images which uses an appropriate combination of a high molecular weight binder resin and a low molecular weight binder resin, an appropriate amount of a releasing agent, and a combination of silica particles and iron oxide particles as external additives, and thus has the following effects: the toner may reduce a generation amount of ultra-fine particles (UFPs) and have enhanced fluidity, charging uniformity, charging stability, transfer efficiency, fixability, durability and a cleaning ability.

主权项

1. A toner to develop electrostatic latent images, the toner comprising a plurality of toner particles, wherein the toner particles comprise:
core particles including a binder resin, a colorant, and a releasing agent; and an external additive attached to outer surfaces of the core particles and including silica particles and iron oxide particles, wherein the releasing agent is carnauba-based wax, wherein an amount of the releasing agent is about 2 to about 2.5 parts by weight based on 100 parts by weight of the binder resin, wherein the binder resin includes a mixture of a high molecular weight binder resin having a number average molecular weight of about 100,000 to about 500,000 g/mol and a low molecular weight binder resin having a number average molecular weight of about 1,000 to less than about 100,000 g/mol in a weight ratio of 90:10 to 10:90, wherein the toner has an endothermic peak by melting of the releasing agent and a stepwise endothermic curve in a second heating curve which is obtained by conducting a differential scanning calorimetry (DSC) measurement of the toner, and wherein a melting temperature Tm determined as a location of the top of the endothermic peak, a glass transition temperature Tg determined as a central point of a linear portion in the stepwise endothermic curve going through glass transition, and a heat of melting ΔH determined as an area of the endothermic peak satisfy the following conditions: 71° C.≦Tm≦75° C., 0.2 J/g≦ΔH≦0.4 J/g, and 58° C.≦Tg≦62° C.