Suspension polymerization method and toner for electrophotography obtained therewith

A toner for use in electrophotography comprising negatively or positively charged polymerized particles, produced by the steps of:

• preparing for a continuous phase component of an aqueous medium;
• preparing a dispersed phase component comprising a monomer composition and at least one solid compound which acts as a charge control agent for maintaining a negative or positive charge on said polymerized particle;
• preparing suspension polymerization means including a continuous phase vessel for holding a continuous phase component, a dispersed phase vessel for holding a dispersed phase component, shearing means for providing a shear force, and a polymerization vessel for a polymerization reaction;
• and in turn
• placing the continuous phase component in the continuous phase vessel and the dispersed phase component in the dispersed phase vessel;
• continuously and simultaneously supplying each of the dispersed phase component and the continuous phase component in the shearing means to form a suspension material including polymerizable liquid-drops of a desired size;
• leading the suspension material to the polymerization vessel;
• and
• subsequently subjecting the suspension material in the polymerization vessel to a polymerization reaction to form a polymerized material to obtain said negatively or positively charged polymerized particle.

A method for producing a toner for use in electrophotography which includes toner particles comprising the steps of:

• preparing a continuous phase component of an aqueous medium;
• preparing a dispersed phase component comprising a monomer composition and at least one solid compound which acts as a charge control agent for maintaining a negative or positive charge on said polyermized particle;
• preparing suspension polyermization means including a continuous phase vessel for holding a continuous phase component, a dispersed phase vessel for holding a dispersed phase component, shearing means for providing a shear force, and a polymerization vessel for polymerization reaction;
• and in turn
• placing the continuous phase component in the continuous phase vessel and the dispersed phase component in the dispersed phase vessel;
• continuously and simultaneously supplying each of the dispersed phase component and the continuous phase component, separately, to the shearing means for providing a shear force;
• exerting a shear force on the dispersed phase component and the continuous component in the shearing means to form a suspension material including polymerizable liquid drops of a desired size;
• leading the suspension material to the polymerization vessel;
• and
• subsequently subjecting the suspension material in the polymerization vessel to a polymerization reaction to form the negatively or positively charged polymerized particle.