Electrostatic latent image developing toner and method for production thereof

Claim 1

An electrostatic latent image developing toner comprising spherical core particles composed of at least a coloring agent and a thermoplastic resin and an outer shell layer containing at least a thermoplastic resin and applied in the form of a coating fast to said core particles, said outer shell layer applied in the form of a coating is formed by thermally fixing minute particles of a first thermoplastic resin and minute particles of a second thermoplastic resin satisfying the following conditional formulas I to IV on the surface of said core particles thereby enabling part of the minute particles of said second thermoplastic resin to retain the original particulate form thereof intact in the produced coating and impart a minutely rugged surface to said coating; -0.2≦R≦0.6 (I) -15≦ΔTm≦100 (II) -4≦Δgel≦60 (III) |100 R+ΔTm+4 Δgel|20 (IV) providing that in the expressions R=(R.sub.2 -R.sub.1)/(R.sub.2 +R.sub.1) ΔTm=Tm.sub.2 -Tm.sub.1 Δgel=gel.sub.2 -gel.sub.1 R 1 and R 2 are average particle diameters (micron) respectively of the minute particles of said first thermoplastic resin and the minute particles of said second thermoplastic resin, Tm 1 and Tm 2 are the softening points (°C.) respectively of the minute particles of the first thermoplastic resin and the minute particles of the second thermoplastic resin, and gel 1 and gel 2 are amounts of gel formed (% by weight) respectively of the minute particles of the first thermoplastic resin and the minute particles of said second thermoplastic resin.