BigPatents India

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 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.