Method for producing toner

摘要

A method for producing a toner including the step of melt-kneading a mixture containing a resin binder and a wax with a twin-screw kneader, wherein the resin binder contains three kinds of a resin R1, a resin R2 and a resin R3 having different softening points to each other, wherein the wax contains at least two kinds of a wax W2 and a wax W3 having different melting points to each other, wherein the softening points of R1, R2 and R3 and the melting point W2 meet certain relationships, and wherein the mixture is supplied to the twin-screw kneader in an amount of from 1.3 to 5.0 kg/hr·cm2 per unit cross-sectional area of the screw. The toner obtainable by the method of the present invention can be suitably used in, for example, the development or the like of latent image formed in electrophotography, an electrostatic recording method, an electrostatic printing method, or the like.

主权项

1. A method for producing a toner comprising melt-kneading a mixture comprising a resin binder and a wax with a twin-screw kneader,
wherein the resin binder comprises three kinds of a resin R1, a resin R2 and a resin R3 having different softening points from each other, wherein the resin R1 has a softening point Tm (R1) of from 145° to 160° C., the resin R2 has a softening point Tm (R2) of 122° C. or higher and lower than 145° C., and the resin R3 has a softening point Tm (R3) of 90° C. or higher and lower than 122° C., wherein the wax comprises at least two kinds of a wax W2 and a wax W3 having different melting points from each other, wherein the wax W2 has a melting point Mp (W2) of from 121° to 138° C., and the wax W3 has a melting point Mp (W3) of from 70° to 95° C., wherein Tm (R1), Tm (R2), Tm (R3) and Mp (W2) satisfy the formulas (I) to (3):
Tm(R1)−Tm(R2)>5  (1)Tm(R2)−Tm(R3)>20  (2)Mp(W2)+13>Tm(R2)>Mp(W2)−10  (3) and wherein the mixture is supplied to the twin-screw kneader in an amount of from 1.3 to 5.0 kg/hr·cm2 per unit cross-sectional area of the screw, wherein each of the resin R1, the resin R2 and the resin R3 is an amorphous polyester.