Toner, two-component developer and image forming method

A two-component developer comprising a toner having at least toner particles and an external additive, and a carrier, wherein;

• said toner has;
• (a) in circularity distribution of particles measured with a flow type particle image analyzer, an average circularity of from 0.920 to 0.995, containing particles with a circularity of less than 0.950 in an amount of from 2% by number to 40% by number;
• and
• (b) a weight-average particle diameter of from 2.0 .mu.m to 9.0 .mu.m as measured by Coulter method;
• and
• said external additive has, on the toner particles, at least (i) an inorganic fine powder (A) present in the state of primary particles or secondary particles and having an average particle length of from 10 m.mu.m to 400 m.mu.m and a shape factor SF-1 of from 100 to 130 and (ii) a non-spherical inorganic fine powder (B) formed by coalescence of a plurality of particles and having a shape factor SF-1 of greater than 150.

An image forming method comprising;

• (I) a charging step of electrostatically charging a latent image bearing member on which an electrostatic latent image is to be held;
• (II) a latent image forming step of forming the electrostatic latent image on the latent image bearing member thus charged;
• (III) a developing step of developing the electrostatic latent image on the latent image bearing member by the use of a toner to form a color toner image;
• and
• (IV) a transfer step of transferring to a transfer medium the toner image formed on the latent image bearing member;
• wherein;
• said toner comprises toner particles and an external additive;
• and
• said toner has;
• (a) in circularity distribution of particles measured with a flow type particle image analyzer, an average circularity of from 0.920 to 0.995, containing particles with a circularity of less than 0.950 in an amount of from 2% by number to 40% by number;
• and
• (b) a weight-average particle diameter of from 2.0 .mu.m to 9.0 .mu.m as measured by Coulter method;
• and
• said external additive has, on the toner particles, at least (i) an inorganic fine powder (A) present in the state of primary particles or secondary particles and having an average particle length of from 10 m.mu.m to 400 m.mu.m and a shape factor SF-1 of from 100 to 130 and (ii) a non-spherical inorganic fine powder (B) formed by coalescence of a plurality of particles and having a shape factor SF-1 of greater than 150.