Toner, toner stored unit, and image forming apparatus
A toner including a binder resin, wherein a toner extract obtained by drying an extraction liquid obtained through Soxhlet extraction of the toner with tetrahydrofuran (THF) has glass transition temperature Tg in a range of from 35° C. through 55° C., and a moisture-content change rate of the toner extract before and after leaving the toner extract to stand for 3 days in an environment of 40° C. and 70% RH is 0.5% or less, and wherein a specific-surface-area change rate of the toner before and after leaving the toner to stand for 3 days in an environment of 40° C. and 70% RH is in a range of from 15% through 50%.
1. A toner comprising:
a binder resin comprising a crystalline polyester resin and an amorphous polyester resin, the amorphous polyester resin having a terminal group blocked with benzoic acid, wherein:
the toner has an endothermic peak in a range of from 40° C. through 70° C. at a first heating, and an endothermic peak in a range of from 20° C. through 50° C. at a second heating, as measured by differential scanning calorimetry (DSC),
a toner extract obtained by drying an extraction liquid obtained through Soxhlet extraction of the toner with tetrahydrofuran (THF) has glass transition temperature Tg in a range of from 35° C. through 55° C., and a moisture-content change rate of the toner extract before and after leaving the toner extract to stand for 3 days in an environment of 40° C. and 70% RH calculated as:
moisture-content change rate (%)=((weight after leaving to stand-weight before leaving to stand)/weight before leaving to stand)×100
is 0.5% or less, and
a specific-surface-area change rate of the toner before and after leaving the toner to stand for 3 days in an environment of 40° C. and 70% RH calculated as:
toner specific surface area change rate (%)=((BET specific surface area before storage-BET specific surface area after storage)/BET specific surface area before storage)×100
is in a range of from 15% through 50%.
2. A toner stored unit comprising:
a toner stored in the toner stored unit,
wherein the toner is the toner of claim 1 .
3. The toner according to claim 1 , wherein the binder resin further comprises a urea-modified polyester resin.
4. The toner according to claim 1 , wherein a ratio (Dw/Dn) of a weight average particle diameter (Dw) of the toner to a number average particle diameter (Dn) of the toner is 1.00-1.20.
5. An image forming apparatus comprising:
an electrostatic latent image bearer;
an electrostatic latent image forming unit configured to form an electrostatic latent image on the electrostatic latent image bearer;
a developing unit containing a toner and configured to develop the electrostatic latent image with the toner to form a visible image;
a transferring unit configured to transfer the visible image onto a recording medium to form a transferred image; and
a fixing unit configured to fix the transferred image on the recording medium,
wherein the toner is the toner of claim 1 .