| 摘要 |
PURPOSE:To obtain a developer prevented from offset without using an offset preventing liquid and fixable at a lower fixing temp. by using a developer composed essentially of a binder resin consisting mainly of a vinyl type polymer and having a specified viscosity, and a colorant. CONSTITUTION:The binder resin is prepared by copolymerizing a styrene or its deriv. for forming the main skeleton of the resin, with an ethylenic monocarboxylic acid or its ester for controlling the thermal characteristics, such as softening point, triboelectrifiability and triboelectrification amt. The binder resin resin is tested with the flow tester of the KOBUNSHI KAGAKU KYOKAI Method; the sample 3 is heated at a constant temp. rise speed, a load of 20kg/cm<2> is applied with a plunger 1 to extrude it through a nozzle 4 of 1mm diameter and 1mm length, its apparent viscosity is calculated continuously, its natural logarithm is plotted versus the temp., the inclination of the straight line approximating to the plotted curve is obtained, and the absolute value of the inclination is regulated to <=0.15ln(poise)/ deg.C. The softening point of the flow tester is, preferably, within 100-160 deg.C. |
