TONER COMPOSITION COMPRISING ROSIN MODIFIED STYLENE ACRYLIC RESIN

摘要

PURPOSE: To obtain a toner compsn. requiring a relatively small amt. of an electric charge controlling agent by using a thermal reactional product of a soln.-polymerized styrene-acrylic copolymer with rosin and a solvent. CONSTITUTION: A mixture of a soln.-polymerized styrene-acrylic copolymer with rosin and a proper solvent such as toluene or xylene is subjected to steam stripping, cooled and pulverized to produce rosin modified styrene-acrylic resin. At this time, the amt. of the copolymer is 55-91wt.% and that of the rosin is 9-45wt.%. The rosin modified resin has at least prescribed specific positive charges and a dry toner compsn. using the resin is positively charged. This compsn. has specific positive charges and a relatively small amt. of an electric charge controlling agent is required so as to develop a positive image.