Toner and two-component developer
A toner includes a toner particle containing a binder resin containing a crystalline polyester. In differential scanning calorimetry (DSC), the toner is heated to 180° C. at a rate of 10° C./min, then cooled to 25° C. at a rate of 10° C./min and successively from 25° C. to 15° C. at a rate of 3° C./min, and heated again to 180° C. at a rate of 10° C./min. As a result, an exothermic amount P1 when the toner is cooled from 80° C. to 40° C. is 1.00 J/g or less, an exothermic amount P2 when the toner is cooled from 25° C. to 15° C. is 0.10 J/g or more, and when a sum of endothermic amounts P3 (J/g) when the toner is heated again from 40° C. to 180° C. and a sum of exothermic amounts P4 (J/g) when the toner is cooled from 180° C. to 40° C. satisfies 2.0≤P3-P4≤10.0.
1 . A toner, comprising:
a toner particle containing a binder resin,
the binder resin comprising a crystalline polyester, an amorphous resin A, an amorphous resin B, and an amorphous resin C;
amorphous resin A being a low-molecular-weight polyester;
amorphous resin B being a high-molecular-weight polyester; and
amorphous resin C being a hybrid resin obtained by combining a polyester resin and an acrylic resin, wherein
when differential scanning calorimetry (DSC) of the toner sequentially undergoes (i) a first temperature rise process of raising a temperature of the toner from normal temperature to 180° C. at a rate of 10° C./min, (ii) a first cooling process of cooling the toner from 180 to 25° C. at a rate of 10° C./min, (iii) a second cooling process of subsequently cooling the toner from 25 to 15° C. at a rate of 3° C./min, and (iv) a second temperature rise process of raising the temperature of the toner to 180° C. at a rate of 10° C./min,
an exothermic amount P1 of an exothermic peak derived from the crystalline polyester present at 40 to 80° C. observed in the first cooling process is 1.00 J/g or less,
an exothermic amount P2 of an exothermic peak derived from the crystalline polyester observed in the second cooling process is 0.10 J/g or more,
2.0≤P3−P4≤10.0 when P3 (J/g) is a sum of endothermic amounts of the endothermic peaks present at 40° C. or higher observed in the second temperature rise process, and P4 (J/g) is a sum of exothermic amounts of the exothermic peaks present at 40° C. or higher observed in the first cooling process, and
2.00≤SP1−SP4≤2.90
0.20≤SP2−SP1≤0.60
0.20≤SP3-SP2≤0.60 when SP1 [(J/cm 3 ) 0.5 ] is an SP value of amorphous resin A, SP2 [(J/cm 3 ) 0.5 ] is an SP value of amorphous resin B, SP3 [(J/cm 3 ) 0.5 ] is an SP value of amorphous resin C, and SP4 [(J/cm 3 ) 0.5 ] is an SP value of the crystalline polyester.
2 . The toner according to claim 1 , wherein P1 is 0.50 J/g or less.
3 . The toner according to claim 1 , wherein a content ratio of the crystalline polyester to the binder resin in the toner is 8.0 to 15.0% by mass.
4 . The toner according to claim 1 , wherein the toner contains a hydrocarbon-based wax, and
2≤T1−T2≤10 when T1 (° C.) is a melting point of the hydrocarbon-based wax and T2 (° C.) is a melting point of the crystalline polyester.
5 . A two-component developer comprising:
a toner; and
a magnetic carrier;
the toner comprising a toner particle containing a binder resin,
the binder resin comprising a crystalline polyester, an amorphous resin A, an amorphous resin B, and an amorphous resin C;
amorphous resin A being a low-molecular-weight polyester;
amorphous resin B being a high-molecular-weight polyester; and
amorphous resin C being a hybrid resin obtained by combining a polyester resin and an acrylic resin, wherein
when differential scanning calorimetry (DSC) of the toner sequentially undergoes (i) a first temperature rise process of raising a temperature of the toner from normal temperature to 180° C. at a rate of 10° C./min, (ii) a first cooling process of cooling the toner from 180 to 25° C. at a rate of 10° C./min, (iii) a second cooling process of subsequently cooling the toner from 25 to 15° C. at a rate of 3° C./min, and (iv) a second temperature rise process of raising the temperature of the toner to 180° C. at a rate of 10° C./min,
an exothermic amount P1 of an exothermic peak derived from the crystalline polyester present at 40 to 80° C. observed in the first cooling process is 1.00 J/g or less,
an exothermic amount P2 of an exothermic peak derived from the crystalline polyester observed in the second cooling process is 0.10 J/g or more,
2.0≤P3−P4≤10.0 when P3 (J/g) is a sum of endothermic amounts of the endothermic peaks present at 40° C. or higher observed in the second temperature rise process, and P4 (J/g) is a sum of exothermic amounts of the exothermic peaks present at 40° C. or higher observed in the first cooling process, and
2.00≤SP1-SP4≤2.90
0.20≤SP2-SP1≤0.60
0.20≤SP3-SP2≤0.60 when SP1 [(J/cm 3 ) 0.5 ] is an SP value of amorphous resin A, SP2 [(J/cm 3 ) 0.5 ] is an SP value of amorphous resin B, SP3 [(J/cm 3 ) 0.5 ] is an SP value of amorphous resin C, and SP4 [(J/cm 3 ) 0.5 ] is an SP value of the crystalline polyester.
6 . The toner according to claim 1 , wherein amorphous resin A and amorphous resin B differ in weight average molecular weight by a factor of 3 or more.