Toner, developer including the toner, and image forming method, image forming apparatus and process cartridge using the toner

A toner comprising:

• a binder resin;
• a colorant, and
• a fluorine-containing compound,
• wherein an atomic ratio (F/C) of a fluorine atom to a carbon atom at a surface of the toner is from 0.010 to 0.110,
• wherein the fluorine-containing compound adheres to the binder resin or an ion of the fluorine-containing compound bonds with the binder resin, and the ion contains the fluorine atom
• wherein a pellet of the toner which is prepared by applying a pressure of 15 kg/cm2 to the toner has a tensile strength of from 900 Pa to 10,000 Pa, and wherein the toner has a methanol wettability of from 25 to 65% by volume, wherein the methanol wettability is measured by a method in which (1) 0.5 g of the toner is dispersed in a mixture solvent of 42 ml of pure water and 18 ml of methanol;
• (2) the mixture is subjected to a dispersion treatment for 5 minutes using an ultrasonic dispersion machine to prepare a toner dispersion;
• and (3) methanol is added to the toner dispersion while checking a transparency of a mixture of methanol and the toner dispersion to determine a transparency dropping point of the toner dispersion, wherein the methanol wettability (MEW) is defined by the following equation:
• MEW(% by volume)={Vm/(Vm+Vw)}×100,
• wherein Vm represents a total volume (ml) of methanol in the mixture at the transparency dropping point, and Vw represents the total volume of pure water in the mixture.