Toner
A toner includes a toner particle containing a binder resin and a silica fine particle A on a surface of the toner particle, wherein D50 on a number basis of the toner is 3.0 to 6.0 the silica fine particle A is a particle having a particle diameter of 80 to 500 nm, the particle diameter being confirmable by observing the toner with a SEM, and when the average coverage with the silica fine particle A determined by image analysis of a particle group of a small particle diameter side of the toner with a SEM is set to S s and the average coverage with the silica fine particle A determined by image analysis of a particle group of a large particle diameter side of the toner with a scanning electron microscope is set to S 1 , S s is 20 to 70 area %, S s and S 1 satisfy S 1 /S s ≤0.80.
1. A toner, comprising:
a toner particle containing a binder resin; and
a silica fine particle A on a surface of the toner particle, said silica fine particle A having a median diameter on a number basis of 80 to 500 nm by observing the toner with a scanning electron microscope, wherein
a median diameter (D50) on a number basis of the toner is 3.0 to 6.0 μm,
when the toner is divided into a first group including a smaller size of the toner particle, and a second group including a larger size of the toner particle, S 1 /S s ≤0.80 and S s is 20 to 70 area %, where S s is an average coverage with the silica fine particle A determined by image analysis of the first group with a scanning electron microscope and S 1 is an average coverage with the silica fine particle A determined by image analysis of the second group with a scanning electron microscope, and
25≤B s and 20≤(S s −B s )+(S 1 −B 1 )≤35 where B s (area %) is an average coverage with the silica fine particle A fixedly adhering to a surface of the toner particle in the first group and B 1 (area %) is an average coverage with the silica fine particle A fixedly adhering to a surface of the toner particle in the second group.
2. The toner according to claim 1 , wherein 0.30≤S 1 /S s ≤0.70.
3. The toner according to claim 1 , wherein the toner contains 4.0 to 7.0 parts by mass of silica fine particle A based on 100 parts by mass of the toner particle.
4. The toner according to claim 1 , wherein the silica fine particle A is fumed silica.
5. The toner according to claim 1 , having a span value of 0.2 to 0.7, where the span value is (D90−D10)/D50, when D90 is a cumulative 90% particle diameter on a number basis of the toner and D10 is a cumulative 10% particle diameter on a number basis of the toner.