Apparatus and process for a polycondensation reaction
Patent 5677415 Issued on October 14, 1997. Estimated Expiration Date: 
March 28, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
March 28, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesInventorAssigneeApplicationNo. 625571 filed on 03/28/1996US Classes:528/176, With polycarboxylic acid or derivative as reactant528/190, Reactant contains a fused- or bridged-ring other than solely as a polycarboxylic acid anhydride group528/193, Two or more phenolic reactants528/194Two or more polycarboxylic acids or derivatives as reactantsExaminersPrimary: Mosley, TerressaForeign Patent References
International ClassC08G 063/00AbstractAn improved process and apparatus for the production of polyester or other polycondesation polymers is disclosed. In particular, polymerization is conducted in a reaction vessel equipped with a specially designed agitator that exposes the polymer melt partially filling the reaction vessel to inert gas flowing through the vessel. The agitator comprises a plurality of elements that lift a portion of a polymer melt in the reaction vessel and generate films of the polymer melt which films extends in planes that are substantially parallel to the axis of the agitator and the flow of gas through the reaction vessel. In a preferred process, a melt of dihydroxy ethyl terephthalate, or its low molecular oligomers, obtained by esterifying terephthalic acid or transesterifying dimethyl terephthalate with ethylene glycol, is intimately contacted with an inert gas at about atmospheric pressure in order to remove the reaction by-products and facilitate polymerization.Other References
Field of SearchWith polycarboxylic acid or derivative as reactantReactant contains a fused- or bridged-ring other than solely as a polycarboxylic acid anhydride group Two or more phenolic reactants Two or more polycarboxylic acids or derivatives as reactants POLYMERIZING IN REACTOR OF SPECIFIED MATERIAL, OR IN REACTOR IN WHICH SURFACE CONTACTING POLYMERIZING MATERIAL HAS BEEN TREATED REMOVING AND RECYCLING REMOVED MATERIAL FROM AN ONGOING POLYMERIZATION ZONE TO A POLYMERIZATION ZONE REMOVING ONLY NONPOLYMERIZED OR NONPOLYMERIZABLE MATERIAL DURING POLYMERIZATION PROCESS | |
