| 摘要 |
PROBLEM TO BE SOLVED: To prevent the unstableness of extrusion caused by the content of moisture in a resin by measuring the moisture content of a thermoplastic polyester resin supplied to an extruder and quantitatively supplying a resin melt characteristic adjusting agent from the additive supply port provided on the way of the barrel of the extruder. SOLUTION: The moisture content of a thermoplastic polyester resin in an extrusion hopper is monitored and a resin melt characteristic adjusting agent is supplied to an extruder from the additive supply port provided on the way of the barrel of the extruder while the addition amt. thereof is matched with the moisture content of the resin. As the melt characteristic adjusting agent, acid anhydride, for example, a compd. having two or more acid anhydrides in one molecule thereof like pyromellitic acid dianhydride is used. Further pref., branched polyester is used as the thermoplastic polyester resin. That is, in order to form a branch structure in a main chain of thermoplastic polyester, a branch forming component having at least three hydroxyl groups and/or carboxyl groups is used. |
