The present invention pertains to a process for the preparation of a toner
powder, in which particles of one or more toner base compositions are
combined into larger particles. The toner base compositions may be in the
form of dry powders, e.g., manufactured by jet milling or by freeze
drying powder dispersions. In that case, the combination of the toner
base compositions into larger particles may be done by, e.g.,
mechanofusion. The toner base composition may also be in the form of an
aqueous emulsion or dispersion. In that case, the combination of the base
compositions into larger particles can be effected by spray-drying the
emulsion or dispersion. In a preferred embodiment, the toner base
composition in aqueous form is prepared via phase inversion
emulsification, which preferably is carried out in an extruder. The
invention also pertains to a toner powder comprising composite particles
in which individual particles of toner base composition(s) are fused or
bonded together in the form of cluster structures that do not break down
under the mechanical and electrostatic forces encountered during toner
use. This can be obtained by mechanofusion of dry toner base powders. The
invention also pertains to a toner powder comprising composite particles
in which individual particles of toner base composition(s) are fused or
bonded together to form single substantially spherical particles. This
can be obtained by spray drying of an aqueous emulsion or dispersion. The
toner powders of the present invention have increased fluidity as
compared to conventional powders. Toners with different colours can be
prepared in a simple and convenient manner.