Toner, two-component type developer, heat fixing method, image forming method and apparatus unit

Abstract

A toner is principally constituted by a binder resin, a colorant and a wax. The toner has a maximum heat-absorption peak of 60-135° C. as measured by differential scanning calorimetry (DSC). The toner further has a viscoelastic characteristic measured at an angular frequency of the toner of 6.28 rad/sec including: a temperature giving a loss molecules G″ of 3×10,Pa of 90-115° C., a temperature giving a loss modulus G″ of 2×10,Pa of 95-120° C., a temperature giving a loss modulus G″ of 1×10,Pa of 105-135° C., a tan &dgr; (loss modulus G″/storage modulus G′) when G″=1×10,-3×10,Pa of 0.6-2.0, a storage modulus at 170° C. (G′ (170° C.)) of 1×10,-1×10,Pa, a loss modulus at 170° C. (G″ (170° C.)) of 1×10,-1×10,Pa, and a ratio of a tan &dgr; at 170° C. (tan &dgr;,) to a tan &dgr; at 150° C. (tan &dgr;,) (tan &dgr;,/tan &dgr;,) of 1.05-1.6. The toner contains a tetrahydrofuran (THF)-soluble content exhibiting a molecular weight distribution according to gel permeation chromatography (GPC) chromatogram providing a main peak in a molecular weight region of 2,000-30,000 and a ratio (Mw/Mn) of above 100 between weight-average molecular weight (Mw) and number-average molecular weight (Mn). The resultant toner is effective in improving a low-temperature fixability and a high-temperature anti-offset characteristic while retaining an appropriate gloss of a fixed image in a broader temperature range.