Toner
Provided is a toner having a toner particle containing a binder resin and a wax, wherein the wax concentrations near the outermost surface of the toner and in the surface layer region below the outermost surface are controlled, so that the wax moves with high efficiency to near the outermost surface during heating.
1. A toner comprising a toner particle containing a binder resin and a wax, wherein
a cross-section of the toner observed under a transmission electron microscope shows at least 5 wax domains having an aspect ratio of at least 5, and
the toner satisfies the following formulae (1) to (3):
Ps/Pd≤0.90 (1)
2.20≤Ph/Pd (2)
0.50≤Pd≤3.00 (3)
where Pd represents an intensity of the highest absorption peak in a range of 2843 cm −1 to 2853 cm −1 when an intensity of the highest absorption peak in a range of 3022 cm −1 to 3032 cm −1 is set to 1.00 in an FT-IR spectrum of the toner obtained by an attenuated total reflectance (ATR) method with an infrared light-incidence angle of 45° using diamond as the ATR crystal;
Ps represents an intensity of the highest absorption peak in a range of 2843 cm −1 to 2853 cm −1 when an intensity of the highest absorption peak in a range of 3022 cm −1 to 3032 cm −1 is set to 1.00 in an FT-IR spectrum of the toner obtained by the ATR method with an infrared light-incidence angle of 45° using germanium as the ATR crystal; and
Ph represents an intensity of the highest absorption peak in a range of 2843 cm −1 to 2853 cm −1 when an intensity of the highest absorption peak in a range of 3022 cm −1 to 3032 cm −1 is set to 1.00 in an FT-IR spectrum of a toner sample obtained by the ATR method with an infrared light-incidence angle of 45° using germanium as the ATR crystal, and the toner sample is obtained by heating the toner at 150° C. for 0.10 seconds and then leaving same to cool to 25° C.
2. The toner according to claim 1 , wherein the content of the wax is 2.0 to 30.0 mass parts per 100.0 mass parts of the binder resin.
3. The toner according to claim 1 , wherein the binder resin is a styrene acrylic resin.
4. The toner according to claim 1 , wherein the wax is a hydrocarbon wax.
5. The toner according to claim 1 , wherein the number of wax domains with an aspect ratio of at least 5 in a cross-section of the toner when the toner cross-section is observed under a transmission electron microscope is not more than 150.
6. The toner according to claim 1 , wherein the endothermic quantity per unit mass derived from the wax in differential scanning calorimetric (DSC) measurement of the toner is 80 to 100.0% given 100.0% as an endothermic quantity per unit mass of the wax alone in DSC measurement.
7. The toner according to claim 1 , wherein the toner particle has a core-shell structure, in which the core contains the binder resin and the wax, and the shell contains a polar resin.