Patent ID: 9221971
Filing Date: 2015-12-29
Classification: B32B,C08G,C08L,Y10T

Abstract:
1. A process for preparing an extrusion-blow-moldable co-polyester resin composition; the process comprising: (a) charging in a reactor to obtain a reaction mixture; (b) subjecting the reaction mixture to an esterification, an ester-interchange reaction, or glycolysation, to yield a pre-polymer; (c) charging a chain extender, in a proportion of about 0.05 wt. % to about 2.0 wt. % with respect to a total mass of the reaction mixture, in the reaction mixture during (b) in at least one portion or continuously at a controlled dosing rate when an intrinsic viscosity of the reaction mixture is <0.20; (d) subjecting the pre-polymer to polycondensation at a temperature in the range of about 270° C. to about 305° C. under a pressure of less than 10 mb, to obtain amorphous chips such that an intrinsic viscosity of the amorphous chips ranges from 0.40 to 0.80; (e) crystallizing the amorphous chips at a temperature ranging from about 110° C.-170° C., to obtain crystallized chips with a crystallinity of more than 30%; and (f) processing the crystallized chips in a solid state polymerizer at a temperature in the range of about 190° C. to about 225° C. until an intrinsic viscosity of processed chips ranging from about 0.70 to about 2.0 is achieved, to obtain an EBM grade co-polyester resin composition.