Patent ID: 8026030

Claim:
A toner, comprising at least: a binder resin which includes a high-molecular weight resin and a branched low molecular weight resin; and a colorant, wherein: a softening point of the high-molecular weight resin measured by using a flow tester is 110 to 150° C.; a softening point of the branched low molecular weight resin measured by using a flow tester is 80 to 105° C.; a square radius of inertia Rt at a peak top of a main peak in GPC-RALLS-viscometer analysis of tetrahydrofuran (THF) soluble matter when the toner is dissolved in a THF solvent at 25° C. for 24 hours is 1.0 nm to 3.8 nm; the square radius of inertia Rt and an square radius of inertia Rp at a peak top of a main peak in GPC-RALLS-viscometer analysis of THF soluble matter when linear polystyrene, having an absolute peak molecular weight value at the same value as a main peak value of the toner, is dissolved in a THF solvent at 25° C. for 24 hours satisfy the following expression 1 0.10 <Rt/Rp< 0.80 (Ex. 1); and a square radius of inertia RgL at a peak top of a main peak in GPC-RALLS-viscometer analysis of THF soluble matter when the branched low molecular weight resin is dissolved in a THF solvent at 25° C. for 24 hours and a square radius of inertia Rgp at a peak top of a main peak in GPC-RALLS-viscometer analysis of THF soluble matter when linear polystyrene, having an absolute peak molecular weight value at the same value as a main peak value of the branched low molecular weight resin, is dissolved in a THF solvent at 25° C. for 24 hours satisfy the following expression 2: 0.50 <RgL/Rgp< 0.80 (Ex. 2), wherein the low molecular weight resin has a peak molecular weight MpL according to the GPC-RALLS viscometer analysis of THF soluble matter of 5,000 to 20,000, wherein the high-molecular weight resin has a peak molecular weight MpH according to the GPC-RALLS viscometer analysis of THF soluble matter of 10,000 to 40,000, wherein the branched low molecular weight resin is a hybrid resin in which a polyester unit and a vinyl polymer unit are chemically bound to each other, and wherein the polyester unit is formed from a trivalent or more carboxylic acid monomer or an acid anhydride of the trivalent or more carboxylic acid monomer in an amount from 0.6 to 6.2 mol %.