Process for preparing high molecular weight polyesters
Patent 5663281 Issued on September 2, 1997. Estimated Expiration Date: 
July 30, 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.
July 30, 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 ReferencesHigh molecular weight linear polyesters and method for their preparation Process for increasing the direct esterification reaction rate of a diacid with a glycol Patent #: 5015759 InventorAssigneeApplicationNo. 688477 filed on 07/30/1996US Classes:528/272, From di- or higher ester of a polycarboxylic acid as sole reactant, or from a polycarboxylic acid or derivative with a compound containing two or more hydroxyl groups or salts thereof528/176, With polycarboxylic acid or derivative as reactant528/190, Reactant contains a fused- or bridged-ring other than solely as a polycarboxylic acid anhydride group528/191, Reactant contains a halogen atom other than solely as halogen atom bonded to a carbonyl group528/192, Ethylenically unsaturated reactant528/193, Two or more phenolic reactants528/194, Two or more polycarboxylic acids or derivatives as reactants528/271FROM CARBOXYLIC ACID OR DERIVATIVE THEREOFExaminersPrimary: Mosley, TerressaAttorney, Agent or FirmForeign Patent References
International ClassC08G 063/02AbstractAn improved process for preparing high molecular weight polyester polymers, such as poly(butylene terephthalate), an alkylene glycol and a di- or tricarboxylic acid by first preparing a pre-polymer in the form of uniform solid particles having an intrinsic viscosity of from 0.1 to about 0.3 dL/gm and a chemical composition which contains greater than a 1% stoichiometric excess of the alkylene glycol above the amount required to produce a high molecular weight polymer, and polymerizing the pre-polymer in the solid state.Field of SearchWith polycarboxylic acid or derivative as reactantReactant contains a fused- or bridged-ring other than solely as a polycarboxylic acid anhydride group Reactant contains a halogen atom other than solely as halogen atom bonded to a carbonyl group Ethylenically unsaturated reactant Two or more phenolic reactants Two or more polycarboxylic acids or derivatives as reactants FROM CARBOXYLIC ACID OR DERIVATIVE THEREOF From di- or higher ester of a polycarboxylic acid as sole reactant, or from a polycarboxylic acid or derivative with a compound containing two or more hydroxyl groups or salts thereof | |
