| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a pressure sensitive adhesive sheet that a toner image as confidential information on the surface of the folded sheet is not transferred to the counter face and that the same adhesive face without contamination can be kept after peeled as during printing, by using toner particles with deposition of inorg. fine particles on the surface. SOLUTION: This toner is prepared by first mixing specified proportions of a binder resin and coloring agent or the like, melting, kneading, pulverizing, classifying and if required, heat treating to produce color fine particles. Then inorg. fine particles are deposited on the surfaces of the color fine particles by spraying inorg. fine particles to the color fine particles by a mixing machine. As for the inorg. fine particles, iron oxide and titanium oxide are preferably used because these particles are easily and uniformly deposited on the surfaces of the color fine particles. The average particle size of the inorg. fine particles is preferably 0.1 to 0.6μm. If it is less than 0.1μm, the effect to prevent the toner from transferring to the counter face of the pressure-sensitive sheet is not enough obtd. If the size is larger than 0.6μm, developing property of the toner decreases, which easily causes problems of the image quality of a printed image.</p> |
