Toner and toner production method
A toner comprises a toner particle that contains a binder resin having a crystalline resin and an amorphous resin, and a wax, wherein a matrix-domain structure made up of a matrix including the crystalline resin, and domains including the amorphous resin, is present in a cross-sectional observation of the toner, the crystalline resin has a specific monomer unit, in a differential curve, which is obtained through differentiation of a temperature-storage elastic modulus curve by temperature, with temperature being a horizontal axis and a common logarithm Log G′ of a storage elastic modulus G′ being a vertical axis as obtained in a viscoelasticity measurement of the toner, the differential curve has specific minimal values P1 and P2 within specific temperature ranges, and has storage elastic moduli G′ at the temperatures of the minimal values P1 and P2 lie in respective specific ranges.
1 . A toner comprising a toner particle comprising
a binder resin comprising a crystalline resin and an amorphous resin, and
a wax, wherein
a matrix-domain structure made up of a matrix including the crystalline resin, and domains including the amorphous resin, is present in a cross-sectional observation of the toner under a transmission electron microscope,
the crystalline resin has a first monomer unit represented by Formula (1) below;
in a differential curve, which is obtained through differentiation of a temperature-storage elastic modulus curve by temperature, with temperature as a horizontal axis and a common logarithm Log G′ of a storage elastic modulus G′ as a vertical axis as obtained in a viscoelasticity measurement of the toner,
the differential curve has a minimal value P1 in a range of 50 to 70° C., the minimal value P1 being −0.50 to −0.20, and
the differential curve has a minimal value P2 in a range of 80 to 120° C., the minimal value P2 being −0.20 to −0.03;
the storage elastic modulus G′ of the toner at the temperature of the minimal value P1 is 5.0×10 5 to 2.0×10 7 Pa; and
the storage elastic modulus G′ of the toner at the temperature of the minimal value P2 is 1.0×10 2 to 1.0×10 4 Pa;
in Formula (1), R Z1 represents a hydrogen atom or a methyl group, and R 1 represents an alkyl group having 18 to 36 carbon atoms.
2 . The toner according to claim 1 , wherein
with ΔH(T) as a total endothermic quantity J/g per 1 g of wax, derived from the wax, in an endothermic quantity measurement of the toner using a differential scanning calorimeter,
and with ΔH(W) as a total endothermic quantity J/g per 1 g of wax, derived from the wax, in an endothermic quantity measurement of the wax,
ΔH(T) and ΔH(W) satisfy 0.70≤ΔH(T)/ΔH(W)≤0.90.
3 . The toner according to claim 1 , wherein a content ratio of the first monomer unit in the crystalline resin is at least 30.0 mass %, relative to mass of all monomer units in the crystalline resin.
4 . The toner according to claim 1 , wherein the amorphous resin is an amorphous polyester resin.
5 . The toner according to claim 1 ,
wherein in a cross-sectional observation of the toner under a transmission electron microscope,
a number-average diameter of the domains is 0.05 to 3.00 μm.
6 . The toner according to claim 1 , wherein
in a cross-sectional observation of the toner under a transmission electron microscope,
a ratio of the domains relative to a combined surface area of the matrix and the domains is 30 to 65 area %.
7 . The toner according to claim 1 , wherein the crystalline resin contains a second monomer unit represented by Formula (2) below, and a third monomer unit represented by Formula (3) below:
in Formula (2), R 2 represents a hydrogen atom or a methyl group, and
in Formula (3), X represents —O— or —NH—, R 4 represents a hydrogen atom or a methyl group, and R 3 represents an alkylene having 2 to 6 carbon atoms.
8 . The toner according to claim 1 , wherein
the wax is a hydrocarbon wax, and
a melting point of the wax is 90° C. or higher.
9 . The toner according to claim 1 , wherein
with SP1 being an SP value (J/cm 3 ) 0.5 of the crystalline resin, SP2 being an SP value (J/cm 3 ) 0.5 of the amorphous resin, and SP3 being an SP value (J/cm 3 ) 0.5 of the wax,
the SP1, SP2 and SP3 satisfy the following relationships:
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10 . The toner according to claim 1 , wherein
the toner particle comprises an inorganic filler particle, and
a content ratio of the inorganic filler particle in the toner particle is 5 to 20 parts by mass, relative to 100 parts by mass of the binder resin.
11 . The toner according to claim 10 , wherein the inorganic filler particle is treated with a fatty acid.
12 . A method for producing the toner according to claim 1 ,
the method comprising:
a melt-kneading step of melt-kneading a mixture that contains the binder resin having the crystalline resin and the amorphous resin, and the wax; and
an annealing step of holding a melt-kneaded product obtained after the melt-kneading step at a temperature of 40 to 60° C., for 30 minutes or longer.