Toner

A toner comprising a toner particle, said toner particle comprising:

• a binder resin comprising a polyester resin;
• and
• a polyolefin resin having a sulfonic acid group, the polyolefin resin being a polymer in which a vinyl polymer is bonded to a polyolefin;
• and
• a content ratio of a monomer unit containing a sulfonic acid group in the vinyl polymer being 1.0 to 20.0 mass %, wherein
• when the toner is divided using an inertial classification system into a first group having a large particle size and a second group having a small particle size so that the number of toner particles in the first and second groups are substantially equal, 1.10≤(As/Bs)/(Al/Bl)≤2.00
• where As is a ratio of an intensity of a maximum absorption peak in a range from 1130 to 1170 cm−1 assigned to a sulfonic acid group contained in the polyolefin resin with respect to an intensity of a maximum absorption peak in a range from 1713 to 1723 cm−1 assigned to carbonyl in the polyester resin in a FT-IR spectrum obtained by measuring the second group by an ATR method using Ge as an ATR crystal where an infrared light incidence angle is 45°,
• Bs is a ratio of an intensity of a maximum absorption peak in a range from 1130 to 1170 cm−1 assigned to a sulfonic acid group contained in the polyolefin resin with respect to an intensity of a maximum absorption peak in a range from 1713 to 1723 cm−1 assigned to carbonyl in the polyester resin in a FT-IR spectrum obtained by measuring the second group by an ATR method using diamond as an ATR crystal where an infrared light incidence angle is set to 45°,
• Al is a ratio of an intensity of a maximum absorption peak in a range from 1130 to 1170 cm−1 assigned to a sulfonic acid group contained in the polyolefin resin with respect to an intensity of a maximum absorption peak in a range from 1713 to 1723 cm−1 assigned to carbonyl in the polyester resin in a FT-IR spectrum obtained by measuring the first group by an ATR method using Ge as an ATR crystal where an infrared light incidence angle is set to 45°, and
• Bl is a ratio of an intensity of a maximum absorption peak in a range from 1130 to 1170 cm−1 assigned to a sulfonic acid group contained in the polyolefin resin with respect to an intensity of a maximum absorption peak in a range from 1713 to 1723 cm−1 assigned to carbonyl in the polyester resin in a FT-IR spectrum obtained by measuring the first group in accordance with an ATR method using diamond as an ATR crystal where an infrared light incidence angle is set to 45°;
• and
• the toner has a span value of 1.1 to 2.0 defined as (D90−D10)/D50
• when D90 is a particle diameter of the toner at which a cumulative number of particles in increasing order of particle diameter is 90%, D10 is a particle diameter of the toner at which a cumulative number of particles in increasing order of particle diameter is 10%, and a number-basis median diameter D50 of the toner is 3.0 to 6.0 um.