Toner for use in electrophotography, image formation method using the toner, method of producing the toner, and apparatus for producing the toner

A full-color image formation method for forming full-color images, using a toner comprising toner particles and a fluidity-imparting agent, said toner particles having an average circularity of 0.93 to 0.97, with a residue of said toner being in an amount of 10 mg or less when 100 g of said toner is sieved with a 500-mesh sieve, said full-color electrophotographic image formation method using an intermediate image transfer method comprising (1) a first image transfer step of repeating a plurality of times the transfer of a toner image formed on a toner image bearing member successively from said toner image bearing member to an endless-shaped intermediate image transfer member so as to form a superimposed toner image, and (2) a second image transfer step of transferring said superimposed toner image en bloc from said intermediate image transfer member to an image transfer material.

A method of producing a toner for use in electrophotography, comprising the step of mixing a fluidity-imparting agent with a classified toner preparation material, using a rotary agitator blade mixer equipped with a rotary agitator blade, under the conditions which satisfy a formula:

• 50≦(V·T)/M≦200
• wherein V is a peripheral speed (m/sec) of said rotary agitator blade of said rotary agitator blade mixer, T is a stirring and mixing time (sec), and M is a weight (kg) of said toner to be stirred and mixed.

An apparatus for producing a toner for use in electrophotoqraphy comprising:

• a rotor type crusher comprising a fixed container serving as an external wall and a rotor having the same rotary shaft as that for said fixed container, and
• a pneumatic conveying classifier which is connected to said rotor type crusher, through said rotor type crusher and said pneumatic conveying classifier, a classified toner preparation material being circulated.

A rotary toner supply container free of any rotary agitator blade, in which there is held a toner which comprises toner particles and a fluidity-imparting agent, said toner particles having an average circularity of 0.93 to 0.97, with a residue of said toner being in an amount of 10 mg or less when 100 g of said toner is sieved with a 500-mesh sieve, said toner being for use in an electrophotographic image formation method using an intermediate image transfer method which comprises (1) a first image transfer step of transferring a toner image formed on a toner image bearing member from said toner image bearing member to an endless-shaped intermediate image transfer member so as to form a toner image thereon, and (2) a second image transfer step of transferring said toner image from said intermediate image transfer member to an image transfer material.