Patent ID: 9696646
Date: 2017-07-04
CPC Classifications: G03G

Claim:
1. A preparation method of the suspension polymerization toner of core-shell structure with dense charges, comprising following steps: (1) preparing a low glass-transition temperature (low-Tg) monomer oil phase and aqueous dispersion liquid for dispersing the low-Tg monomer oil phase respectively; (2) mixing the low-Tg monomer oil phase with the aqueous dispersion liquid, and transferring mixture into a reactor after carrying out high-speed shearing and suspension granulation, then carrying out a first polymerization reaction to convert monomer oil droplet particles to polymer particles completely, and obtaining the soft toner core particles, the preparation process of the monomer oil phase includes the following step: adding the colorant, the release agent into a monomer forming the soft core resin monomer, after uniformly grinding and dispersing with a sand mil, further adding a crosslinker, a molecular weight regular and an initiator to prepare a monomer oil phase, the glass transition temperature of the toner core resin is 40˜60° C.; (3) adding a high glass-transition temperature (high-Tg) shell monomer forming the rigid shell layer into water containing a surfactant, after carrying out high-speed shearing or ultrasound to form a fine emulsion having an average particle diameter of 50-200 nm, adding a emulsion into a suspension dispersion system comprising the soft toner core particles, then adding resin-type charge control agent (CCA) dispersion liquid and a water-soluble initiator to carry out a second polymerization reaction, thereby obtaining the rigid shell layer with dense charges, the high-Tg monomer forming rigid shell layers have a glass-transition temperature greater than 80° C., the resin-type CCA is selected from a homopolymer or copolymer sulfonic acid group or a quaternary ammonium salt group; and (4) cleaning a product formed in the second polymerization reaction until a conductivity of a filtrate being no more than 10 μS/cm, carrying out a silica external additive treatment after a further filtration and dry, then obtaining the suspension polymerization toner of core-shell structure with dense charges.