| 摘要 |
<p>PROBLEM TO BE SOLVED: To ensure a large quantity of electric charges even in an environment of high temp. and humidity by using an ionic compd. consisting of an anion having plural hydroxyl groups and an onium ion. SOLUTION: This magnetic toner contains at least a bonding resin, a magnetic substance and an ionic compd. consisting of an anion having two or more hydroxyl groups and an onium ion. The principal skeleton of the anion is preferably a naphthalene ring to which one specified sulfonic acid group or none may be added. When a hydroxyl group exists at a position apart from the position of carbon atom having a sulfonic acid group by >=3 carbon atoms, the quantity of electric charges is increased and image density is made stable and high. A hydroxyl group exists preferably at a position apart from the position of carbon atom having a sulfonic acid group by >=4 carbon atoms. The electrostatically charged state of the toner is stabilized.</p> |
