To provide the subject method preventing that a charged main raw material or an additive impinges against the upper leading ends of stirring blades or the support part of the stirring blades to scatter to adhere to a reactor wall and capable of obtaining a product of high quality not mixed with discolored foreign matter comprising a deteriorated and peeled deposit.
A mark 9 for judging the stop position of a stirrer is provided to the outer part of a reactor 1 of a stirring shaft 4 wherein the upper leading ends 7 of stirring blades 5 and the position of the support 6 of the stirring blades 5 become the corresponding angle and the position of a charging nozzle 2 at a time of the charging of the main raw material or the additive into the reactor 1 and the mark 9 are regulated so as not to become a corresponding angle position to stop the stirrer to perform charging thereafter.
IMAI SANJI
MURAI MASUO
