| 摘要 |
<p>PURPOSE:To improve pulverizability, blocking resistance and offset resistance of the toner by using as a component of the toner a resin composition which contains as its principal constituent a crosslinked copolymer contg. residual unreacted acid groups and has a specific melt viscosity curve. CONSTITUTION:The copolymer which comprises as the principal constitutional units a styrene based monomer and a vinyl based monomer having an acid group is crosslinked by using a multivalent metallic compound so that the unreacted acid groups remain in the crosslinked copolymer. This resin composition for the toner shows a prescribed melt viscosity curve having the maximum by subjecting the unreacted acid groups to crosslinking reaction with the multivalent metallic compound at the time of melting and kneading the composition within a prescribed temp. range or at the time of heating the composition when the toner is used. The offset resistance of the toner is reduced as the temp., at which the melt viscosity curve shows the maximum, becomes lower and the pulverizability of the toner is reduced as the above temp. becomes higher. Therefore the temp., at which the melt viscosity curve shows the maximum, is limited within the range of 180 to 260 deg.C Preferably, the melt viscosity curve shows the maximum within the range of 180 to 260 deg.C and the minimum within the range or 160 to 240 deg.C.</p> |
