Process for polymerization of polyester oligomers
Patent 5811496 Issued on September 22, 1998. Estimated Expiration Date: 
December 21, 2015. 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.
December 21, 2015. 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 3480587 3496146 3590072 Polybutylene terephthalates having a low carboxyl content and continuous process for the production thereof Patent #: 4212963 InventorsAssigneeApplicationNo. 576657 filed on 12/21/1995US Classes:525/444, Mixed with polycarboxylic acid or derivative and polyhydroxy reactant or polymer thereof525/437, Solid polymer derived from polyhydroxy reactant and polycarboxylic acid or derivative reactant; or derived from di- or higher ester of a polycarboxylic acid as sole 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)528/298, Fused- or bridged-ring-containing reactant other than solely as cyclic acid anhydride group528/308.6, Contains terephthalic acid or substituted forms thereof528/491, Contacting with organic material528/492, Nitrogen containing528/503Temperature maintaining, heating or coolingExaminersPrimary: Acquah, Samuel A.Foreign Patent References
International ClassC08F 020/00AbstractThis invention is directed to an improved process for producing a polyester oligomer. The process employs a pipeline reactor, having at least two stages, in which the degree of polymerization of an oligomeric feed material is raised from about 2-10 to about 2-40 and the ratio of carboxyl to hydroxyl end groups in the product is reduced. In a first stage of the process, a monomeric diol or polyol, such as ethylene glycol, is added to a melt of the oligomeric feed material. In a second stage of the process, the molecular weight of the oligomer is increased by removal of volatile reaction by-products, including water and polyol. The oligomer produced by the present invention may be used in making higher molecular weight polyesters.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 thereofMaterial 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) Fused- or bridged-ring-containing reactant other than solely as cyclic acid anhydride group Contains terephthalic acid or substituted forms thereof Contacting with organic material Nitrogen containing Temperature maintaining, heating or cooling Solid polymer derived from polyhydroxy reactant and polycarboxylic acid or derivative reactant; or derived from di- or higher ester of a polycarboxylic acid as sole reactant Mixed with polycarboxylic acid or derivative and polyhydroxy reactant or polymer thereof | |
