| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide such a toner for magnetic ink character recognition printing that a good printing image is obtd. and that a magnetic material is hardly peeled from the toner surface by using a polystyrene resin as an essential binder component and incorporating a specified magnetic material. SOLUTION: The toner contains a polystyrene resin as essential binder component and contains a magnetic material by 15 to 50wt.% which is subjected to surface treatment with a silane coupling agent by 0.1 to 2.0wt.% of the magnetic material. As for the polystyrene resin, a single styrene polymer or a copolymer of styrene and other monomers which can copolymerize with styrene can be used. As for the copolymerizable monomers, ethylene unsatd. monoolefin such as p-chlorostyrene can be used. The toner binder has at least two peaks in the distribution of mol.wt. The one peak ranges 3,000 to 20,000 weight average mol.wt. which influences the fixing strength, and the other peak ranges 3×10<5> to 15×10<5> weight average. mol.wt. which improves the offset resistance.</p> |
