| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing toner, by which a toner with a small amount of fine power can be produced, as well a feeding rate of a raw material to a kneader is increased to reduce a mixing time, that is, a time period of a melting and kneading process, to improve the productivity, upon melt-kneading a toner raw material such as resin and wax. <P>SOLUTION: The method for producing a toner includes a step of melt-kneading a mixture containing a binder resin and wax in a twin-screw kneader. The binder resin comprises three kinds of a resin R1, a resin R2 and a resin R2 having different softening points from one another; the resin R1 having a softening point Tm(R1) of from 145 to 160°C, the resin R2 having a softening point Tm(R2) of 122°C or higher and lower than 145°C, and the resin R3 having a softening point Tm(R3) of 90°C or higher and lower than 122°C. The wax comprises at least two kinds of a wax W2 and a wax W3 having different melting points from each other; the wax W2 having a melting point Mp(W2) of from 121 to 138°C and the wax W3 having a melting point Mp(W3) of from 70 to 95°C. The temperatures Tm(R1), Tm(R2), Tm(R3) and Mp(W2) satisfy expressions (1):Tm(R1)-Tm(R2)>5, (2):Tm(R2)-Tm(R3)>20, and (3):Mp(W2)+13>Tm(R2)>Mp(W2)-10. The mixture is supplied to the twin-screw kneader in an amount of from 1.3 to 5.0 kg/hr/cm<SP POS="POST">2</SP>per unit cross-sectional area of the screw. <P>COPYRIGHT: (C)2013,JPO&INPIT |
