Continuous polyester process
Patent 5434239 Issued on July 18, 1995. Estimated Expiration Date: 
July 18, 2012. 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 18, 2012. 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 References 2578660 2647885 2789972 2973341 3110547 3390135 3469618 3545520 3594356 Atmospheric pressure process for preparing pure cyclic esters Patent #: 4835293 InventorAssigneeApplicationNo. 138312 filed on 10/18/1983US Classes:528/274, Polymerizing in the presence of a specified material other than reactant528/272, 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 thereof528/279, Material contains a Group IVB metal atom (Ti, Zr, Hf)528/283, Material contains a Group IVA metal atom (Ge, Sn, Pb)528/285, Material contains a Group VA metal atom (As, Sb, Bi)528/308.3, Processes of preparing528/308.6, Contains terephthalic acid or substituted forms thereof528/481, Treating at O Deg C (32 Deg F) or below, or at 200 Deg C (392 Deg F) or above528/489, Oxide or hydroxide528/491, Contacting with organic material528/492, Nitrogen containing528/503Temperature maintaining, heating or coolingExaminersPrimary: Acquah, Samuel A.International ClassC08G 063/78AbstractAn atmospheric pressure process for the continuous production of polyester is disclosed wherein a melt of dihydroxy ethyl terphthalate, or its low molecular oligomers, obtained by esterifying terephthalic acid or transesterifying dimethyl terephthalate with ethylene glycol, is intimately contacted with an inert gas to facilitate polymerization and removal of the reaction by-products. The ethylene glycol evolved and the inert gas are recycled.Field of SearchFrom 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 thereofPolymerizing in the presence of a specified material other than reactant Material contains a Group IVB metal atom (Ti, Zr, Hf) Material contains a Group IVA metal atom (Ge, Sn, Pb) Material contains a Group VA metal atom (As, Sb, Bi) Oxide or hydroxide Treating at O Deg C (32 Deg F) or below, or at 200 Deg C (392 Deg F) or above Contacting with organic material Nitrogen containing Temperature maintaining, heating or cooling Processes of preparing Contains terephthalic acid or substituted forms thereof | |
