Process for producing polyalkylene terephthalate, process for producing polyalkylene terephthalate molding and polyalkylene terephthalate molding

摘要

The present invention provides a method of producing polyalkylene terephthalate, which comprises: introducing a prepolymer of polyalkylene terephthalate that is in a molten state comprising 70 mol % or more of ethylene terephthalate or 1,4-butylene terephthalate repeating units and having an intrinsic viscosity [η] between 0.2 and 2 dl/g through a feed opening to a polymerization reactor; discharging the introduced prepolymer from holes of a perforated plate; and polymerizing the prepolymer under reduced pressure, while allowing the prepolymer to fall along the surface of a support that is open towards the outside at a temperature between the [crystalline melting point−10° C.] of the prepolymer or higher and the [crystalline melting point+30° C.] of the prepolymer or lower under the conditions represented by a formula S1/S2>1, wherein S1 is the surface area of falling polyalkylene terephthalate, and S2 is the area where the support is in contact with polyalkylene terephthalate.