Process cartridge

A process cartridge that is mountable on an image forming apparatus, the process cartridge comprising:

• a developing chamber,
• wherein the developing chamber includes
• a toner,
• a developing roller that develops an electrostatic latent image formed on a surface of a photosensitive drum using the toner to form a toner image,
• a toner supplying roller that supplies the toner to the developing roller, and
• a toner regulating member that regulates a layer thickness of the toner on the developing roller,
• wherein
• a surface of the developing roller is in contact with a surface of the toner supplying roller, a movement direction of the surface of the developing roller is opposite to a movement direction of the surface of the toner supplying roller in a position where the surface of the developing roller is in contact with the surface of the toner supplying roller,
• the movement direction of the surface of the toner supplying roller includes an upward component at the position where the surface of the developing roller is in contact with the surface of the toner supplying roller in a mounting state where the process cartridge is mounted on an apparatus main body of the image forming apparatus,
• the developing roller and the toner supplying roller are configured such that a peripheral speed ratio R represented by Equation (E1) satisfies
• 1.1
• ≤
• R
• ≤
• 2
• .5
• ,
• (
• E1
• )
• R
• =
• V
• R
• ⁢
• S
• /
• V
• D
• (in Equation (E1), VRS represents an absolute value [m/sec] of a peripheral speed of the surface of the toner supplying roller, and VD represents an absolute value [m/sec] of a peripheral speed of the surface of the developing roller),
• the toner contains a toner particle and a silica fine particle,
• the toner particle contains a crystalline resin component,
• a content of the silica fine particle is 1.5 parts by mass or greater and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particle,
• the toner has an aggregation degree of 70.0% or greater and 99.0% or less, and
• in a case where an average area ratio of a domain of the crystalline resin component in a surface layer region to a depth of 200 nm from a surface of the toner particle is defined as As when a cross section of the toner particle is observed using a transmission electron microscope, As is 1.0% by area or less.