| 摘要 |
PURPOSE:To prevent the generation of offsetting even if the temp. of a fixing roller increases to a slightly higher temp. by providing an outside layer which does not contain a resin having a low average mol.wt to the outer periphery of an inside layer contg. a resin having a high average mol.wt. and resin having a low outside periphery. CONSTITUTION:The toner outside layer 2 is provided to the outer periphery of the toner inside layer 1. An AS resin, polystyrene and PP are incorporated as a resin into the toner inside layer 1. On the other hand, the polystyrene having the low weight average mol.wt. is not incorporated into the toner outside layer. More specifically, the inside layer 1 begins to melt when the temp. of the fixing roller rises higher even slightly from the melting temp. of the resin having the low average mol.wt. but the outside layer 2 which does not contain the resin having the low average mol.wt.; the layer consisting of the resin having the high average mol.wt. is provided on the outer periphery of the inside layer 1. Said resin has the high melting temp. and merely attains the softened state but does not melt; therefore, the generation of the offsetting is obviated. |
