Toner
A toner comprises a toner particle comprising a core particle comprising a resin component, a shell coating the surface of the core particle, and a polyvalent metal. The resin component comprises a polyester resin, and the shell comprises an amino resin; in an electron image of a cross section of the toner acquired using a transmission electron microscope, a polyvalent metal content P(M) obtained by energy-dispersive x-ray analysis at the core/shell interface and in the vicinity of this interface is 0.0010 to 2.00 atomic %; and the surface storage elastic modulus of the toner at a load of 30 μN at 25° C., according to nanoindentation measurement of the toner, is from 6.50 GPa to 12.00 GPa.
1. A toner, comprising:
a toner particle comprising a core particle, a shell coating a surface of the core particle, and a polyvalent metal;
the core particle comprising a polyester resin; and
the shell comprising an amino resin, wherein
in an electron image of a cross section of the toner particle acquired using a transmission electron microscope, the polyvalent metal has a content P (M) of 0.0010 to 2.0000 atomic %, according to energy-dispersive x-ray analysis during an execution of a line scan in a range of 0.85d to 1.15d from an outline of the cross section of the toner particle toward a central part of the cross section in a direction perpendicular to the outline, where d (nm) is a thickness of the shell; and
a surface storage elastic modulus of the toner at a load of 30 μN at 25° C. is 6.50 to 12.00 GPa, according to nanoindentation measurement of the toner.
2. The toner according to claim 1 , wherein a surface storage elastic modulus of the toner at a load of 50 μN at 25° C. is 0.20 to 12.00 GPa, according to nanoindentation measurement of the toner.
3. The toner according to claim 1 , wherein the amino resin is a thermosetting resin.
4. The toner according to claim 1 , wherein the amino resin is at least one member selected from the group consisting of melamine resins, urea resins, guanamine resins and aniline resins.
5. The toner according to claim 1 , wherein the polyvalent metal is at least one member selected from the group consisting of Al, Mg and Ca.
6. The toner according to claim 1 , wherein the shell has an average thickness of 1.0 to 30.0 nm.
7. The toner according to claim 1 , wherein the polyvalent metal is Mg derived from magnesium hydroxide.
8. The toner according to claim 1 , wherein the polyvalent metal is Al derived from aluminum sulfate.
9. The toner according to claim 1 , wherein the polyvalent metal is Mg derived from magnesium chloride.
10. The toner according to claim 1 , wherein the toner further comprises an external additive.
11. The toner according to claim 1 , wherein the amino resin is a melamine resin.