Toner and method of producing toner
A toner containing a toner particle that contains a binder resin including a polyester resin, and a polyolefin resin having —COOM that is a neutralized carboxy group with a monovalent metal ion M, wherein the polyolefin resin having —COOM is a polymer in which a vinyl polymer is bonded to a polyolefin, a content of a monomer unit containing —COOM in the polyolefin resin having —COOM is 1 to 20 mass %, and in a FT-IR spectrum obtained through measurement of a large particle size-side particle group and a small particle size-side particle group obtained by dividing the toner into two substantially equal parts, on a number basis, a ratio of the intensity of a maximum absorption peak in a range from 1545 cm −1 to 1555 cm −1 with respect to the intensity of a maximum absorption peak in a range from 1713 cm −1 to 1723 cm −1 exhibits a specific relationship.
1. A toner, comprising:
a toner particle that contains a binder resin and a polyolefin resin;
the binder resin including a polyester resin;
the polyolefin resin having a carboxy group neutralized with a monovalent metal ion M forming —COOM, the polyolefin resin having —COOM being a polymer in which a vinyl polymer is bonded to a polyolefin with a content ratio of a monomer unit containing —COOM being 1 to 20 mass %, wherein
when the toner is divided by an inertial classifier into a first including a larger size of the toner particles, and a second group including a smaller size of the toner particles, with the number of toner particles in the first group being substantially equal to the number of toner particles in the second group, the toner satisfies
1.50≤( As/Bs )/( Al/Bl )≤2.00
and
1.14≤σ s/σl≤ 1.50
where As denotes a ratio of an intensity of a maximum absorption peak in a range from 1545 cm −1 to 1555 cm −1 , assigned to —COOM contained in the polyolefin resin, with respect to an intensity of a maximum absorption peak in a range from 1713 cm −1 to 1723 cm −1 , assigned to carbonyl in the polyester resin, in a FT-IR spectrum obtained through measurement of the second group in accordance with an ATR method, using Ge as an ATR crystal, and under a condition where an infrared light incidence angle is set to 45°,
Bs denotes a ratio of an intensity of a maximum absorption peak in a range from 1545 cm −1 to 1555 cm −1 , assigned to —COOM contained in the polyolefin resin, with respect to an intensity of a maximum absorption peak in a range from 1713 cm −1 to 1723 cm −1 , assigned to carbonyl in the polyester resin, in a FT-IR spectrum obtained through measurement of the second group in accordance with an ATR method, using diamond as an ATR crystal, and under a condition where an infrared light incidence angle is set to 45°,
Al denotes a ratio of an intensity of a maximum absorption peak in a range from 1545 cm −1 to 1555 cm −1 , assigned to —COOM contained in the polyolefin resin, with respect to an intensity of a maximum absorption peak in a range from 1713 cm −1 to 1723 cm −1 , assigned to carbonyl in the polyester resin, in a FT-IR spectrum obtained through measurement of the first group in accordance with an ATR method, using Ge as an ATR crystal, and under a condition where an infrared light incidence angle is set to 45°,
Bl denotes a ratio of an intensity of a maximum absorption peak in a range from 1545 cm −1 to 1555 cm −1 , assigned to —COOM contained in the polyolefin resin, with respect to an intensity of a maximum absorption peak in a range from 1713 cm −1 to 1723 cm −1 , assigned to carbonyl in the polyester resin, in a FT-IR spectrum obtained through measurement of the first group in accordance with an ATR method, using diamond as an ATR crystal, and under a condition where an infrared light incidence angle is set to 45°,
σs denotes an absolute value of an average value of surface charge density of the second group, and
σl denotes an absolute value of an average value of surface charge density of the first group.
2. The toner according to claim 1 , wherein the toner has a number-basis median diameter D50 of 3.0 to 6.0 μm, and
( D 90- D 10)/ D 50 is 0.20to0.80
where D90 is a particle diameter of the toner at which a cumulative number of particles in increasing order of particle diameter is 90%, and D10 is a particle diameter of the toner at which a cumulative number of particles in increasing order of particle diameter is 10%.
3. The toner according to claim 1 , wherein a content ratio of the vinyl polymer in the polyolefin resin having —COOM is 80 to 95 mass %.
4. The toner according to claim 1 , wherein M is Li + .
5. The toner according to claim 1 , wherein a content ratio of the monomer unit containing —COOM in the polyolefin resin having —COOM is 6 to 20 mass %.
6. The toner according to claim 1 , wherein the vinyl polymer has a structure derived from a cycloalkyl (meth)acrylate.
7. The toner according to claim 1 , wherein 1.15≤σs/σl≤1.45 when σs is an absolute value of an average value of surface charge density of the second group and σl is an absolute value of an average value of surface charge density of the first group.
8. The toner according to claim 1 , wherein the monomer unit containing —COOM is represented by
where X is a hydrogen atom or —COOM, Y is —(CH 2 ) m —COOM, m is an integer from 0 to 3, and Z is a hydrogen atom, a C1 to C3 alkyl group or —COOM.
9. A method of producing the toner according to claim 1 , the method comprising the steps of:
melt-kneading a resin composition containing the polyolefin resin having —COOM and the binder resin including the polyester resin to obtain a kneaded product;
cooling the kneaded product to obtain a cooled product;
pulverizing the cooled product to obtain a toner particle; and
subjecting the toner particle to a thermal treatment by a hot air current having a temperature of 110° C. or higher.