Toner and two-component developer for electrophotographic process and image formation method and image formation apparatus using the toner

A toner comprising toner particles which comprise a binder resin and a coloring agent, wherein

• said toner particles have a weight-average particle size in a range of 6.0 to 9.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 12% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 3 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.70≦D25/D75≦0.85.

A two-component developer comprising a toner and a carrier, said toner comprising toner particles which comprise a binder resin and a coloring agent, wherein

• said toner particles have a weight-average particle size in a range of 6.0 to 11.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 15% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 5 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.60≦D25/D75≦0.85.

A two-component developer comprising a toner and a carrier, said toner comprising toner particles which comprise a binder resin and a coloring agent, wherein

• said toner particles have a weight-average particle size in a range of 6.0 to 9.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 12% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content-ratio of 3 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.70≦D25/D75≦0.85.

A toner cartridge holding therein a toner comprising toner particles which comprise a binder resin and a coloring agent, wherein

• said toner particles have a weight-average particle size in a range of 6.0 to 11.5 μm, and comprise;
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 15% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 5 wt % or less, and
• satisfy the conditions that;
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.60≦D25/D75≦0.85.

A toner cartridge holding therein a toner comprising toner particles which comprise a binder resin and a coloring agent, wherein

• said toner particles have a weight-average particle size in a range of 6.0 to 9.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 12% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 3 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.70≦D25/D75≦0.85.

An image formation method comprising the steps of forming a latent image on a latent image bearing member, developing said latent image to a visible image with a toner, transferring said visible image to an image receiving material, and cleaning said toner remaining on said latent image bearing member,

• said toner comprising toner particles which comprise a binder resin and a coloring agent, wherein
• said toner particles have a weight-average particle size in a range of 6.0 to 11.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 15% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 5 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.60≦D25/D75≦0.85.

An image formation method comprising the steps of forming a latent image on a latent image bearing member, developing said latent image to a visible image with a toner, transferring said visible image to an image receiving material, and cleaning said toner remaining on said latent image bearing member,

• said toner comprising toner particles which comprise a binder resin and a coloring agent, wherein
• said toner particles have a weight-average particle size in a range of 6.0 to 9.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 12% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 3 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.70≦D25/D75≦0.85.

An image formation method comprising the steps of forming a latent image on a latent image bearing member, developing said latent image to a visible image with a two-component developer, transferring said visible image to an image receiving material, and cleaning said toner remaining on said latent image bearing member,

• said two-component developer comprising a toner and a carrier, said toner comprising toner particles which comprise a binder resin and a coloring agent, wherein
• said toner particles have a weight-average particle size in a range of 6.0 to 11.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 15% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 5 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.60≦D25/D75≦0.85.

An image formation method comprising the steps of forming a latent image on a latent image bearing member, developing said latent image to a visible image with a two-component developer, transferring said visible image to an image receiving material, and cleaning said toner remaining on said latent image bearing member,

• said two-component developer comprising a toner and a carrier, said toner comprising toner particles which comprise a binder resin and a coloring agent, wherein
• said toner particles have a weight-average particle size in a range of 6.0 to 9.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 12% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 3 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.70≦D25/D75≦0.85.

An image formation apparatus capable of forming a toner image, using a toner comprising toner particles which comprise a binder resin and a coloring agent, wherein

• said toner particles have a weight-average particle size in a range of 6.0 to 11.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 15% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 5 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.60≦D25/D75≦0.85.

An image formation apparatus capable of forming a toner image, using a toner comprising toner particles which comprise a binder resin and a coloring agent, wherein

• said toner particles have a weight-average particle size in a range of 6.0 to 9.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 12% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 3 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.70≦D25/D75≦0.85.

An image formation apparatus capable of forming a toner image, using a two-component developer comprising a toner and a carrier, said toner comprising toner particles which comprise a binder resin and a coloring agent, wherein

• said toner particles have a weight-average particle size in a range of 6.0 to 11.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 15% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 5 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.60≦D25/D75≦0.85.

An image formation apparatus capable of forming a toner image, using a two-component developer comprising a toner and a carrier, said toner comprising toner particles which comprise a binder resin and a coloring agent, wherein

• said toner particles have a weight-average particle size in a range of 6.0 to 9.5 μm, and comprise:
• toner particles (a) with a particle diameter of 5 μm or less in a content ratio of 1 to 12% by number, and
• toner particles (b) with a particle diameter of twice or more said weight-average particle size in a content ratio of 3 wt % or less, and
• satisfy the conditions that:
• a number-average particle size D25 when the cumulative number of said toner particles reaches 25% at the measurement of a cumulative toner particle-distribution by number thereof, and a number-average particle size D75 when the cumulative number of said toner particles reaches 75% at the measurement of said cumulative toner particle distribution by number thereof are in the relationship of:
• 0.70≦D25/D75≦0.85.