| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a toner excellent in image reproducibility, fixing property, and offset resistance by regulating the gel fraction, glass transition temperature, and soluble molecular weight distribution of a toner binder to respectively specified ranges. SOLUTION: This electriophotographic toner is mainly composed of a coloring agent and a binder. The binder contains 1-40% of gel fraction and has a glass transition temperature of 45-70 deg.C. The gel fraction of the binder is more preferably 5-20%. When the gel fraction is too high, fixing property and developing property are deteriorated, and when it is reversely too low, a problem arises in offset property and image reproducibility. This binder is formed of a vinyl polymer which has only one peak in the molecular weight area of 4,000-50,000 in the molecular weight distribution by gel permeation chromatograph of the tetrahydrofurane soluble content of the binder and has other peak or shoulder in this area, and has no peak or shoulder in the molecular weight areas of 1,000-4,000 and 50,000 or more.</p> |
