Emulsion aggregation toners with improved particle size distribution

A toner composition comprising toner particles comprising:

• a core;
• and
• a shell surrounding the core;
• wherein:
• a ratio of an average particle diameter of the toner particles to an average particle diameter of the core is from about 1.1 to about 1.2;
• the toner particles have a particle size distribution with a lower number ratio geometric standard deviation (GSDn) of from about 1.18 to about 1.20, and an upper geometric standard deviation by volume (GSDv) of from about 1.16 to about 1.17.

A single component developer, comprising:

• a toner composition comprising toner particles comprising:
• a core comprising a styrene-butylacrylate latex resin, the core having a glass transition temperature Tg of from about 51° C. to about 59° C.;
• and
• a shell comprising a styrene-butylacrylate latex resin surrounding the core, the shell having a glass transition temperature Tg of from about 40° C. to about 70° C.;
• wherein:
• the volume average particle diameter of the core is from about 4.5 to about 5.5 μm;
• a ratio of an average particle diameter of the toner particles to an average particle diameter of the core is from about 1.1 to about 1.2;
• the toner particles have:
• a volume average particle diameter of from about 5.5 to about 5.9 μm;
• a weight average molecular weight (Mw) in a range of from about 20,000 pse to about 60,000 pse;
• a number average molecular weight (Mn) in a range of from about 8,000 pse to about 25,000 pse;
• a ratio of Mw to Mn of from about 1.2 to about 5.0;
• a particle size distribution with a lower number ratio geometric standard deviation (GSDn) of from about 1.05 to about 1.12, and an upper geometric standard deviation by volume (GSDv) of from about 1.05 to about 1.12;
• a circularity of from about 0.965 to about 0.999;
• a shape factor of from about 120 to about 150;
• and
• a surface area of from about 0.7 m2/g to about 1.0 m2/g;
• the toner composition has:
• a crease minimum fix temperature (MFT) of from about 155° C. to about 185° C.;
• an offset temperature of from about 205° C. to about 215° C.;
• a flow of from about 15% to about 40%;
• a compressibility of from about 9% to about 14%;
• a density of from about 1.3 to about 1.8;
• a fusing percentage of from about 60% to about 90%;
• a gloss, measured at the minimum fixing temperature (MFT), of from about 5 to about 20 gloss units;
• and
• a parent toner charge per mass ratio (Q/M) of from about −30 μC/g to about −65 μC/g.