Process of making polyester prepolymer
Patent 5786443 Issued on July 28, 1998. Estimated Expiration Date: 
December 12, 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.
December 12, 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 References 2802028 3192184 3506622 3551386 3590072 3676485 3697579 3819585 3927982 Process for preparing polyesters InventorAssigneeApplicationNo. 764370 filed on 12/12/1996US 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 thereof526/67, REMOVING AND RECYCLING REMOVED MATERIAL FROM AN ONGOING POLYMERIZATION ZONE TO A POLYMERIZATION ZONE526/68, Recycling monomer528/274, Polymerizing in the presence of a specified material other than reactant528/296, Reactant contains three or more carboxylic acid groups or is derivative thereof528/298, Fused- or bridged-ring-containing reactant other than solely as cyclic acid anhydride group528/300, Polyhydroxy-containing compound or salt thereof having an ether-oxygen atom as reactant528/301, Acyclic ether-oxygen compound528/302, Two or more carboxylic acid or derivatives or mixtures thereof528/307, Cycloaliphatic ring-containing reactant (other than aryl)528/308, Aryl-containing carboxylic acid or derivative of an aryl-containing dicarboxylic acid528/308.6, Contains terephthalic acid or substituted forms thereof528/484, Preventing or removing reactor or processing equipment buildup528/491, Contacting with organic material528/501, With distilling or pressured reduction step to remove material, e.g., flashing, autorefrigeration, etc.528/503Temperature maintaining, heating or coolingExaminersPrimary: Acquah, Samuel A.International ClassC08G 063/02AbstractA continuous process for preparing polyester prepolymer comprising the steps of esterifying a diacid with a diol, reacting the esterified product with additional diol, and passing the product downward through a countercurrent column reactor while inert gas flows upward through the column reactor. The resulting prepolymer product has fewer acid end groups than the esterified material.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 Reactant contains three or more carboxylic acid groups or is derivative thereof Fused- or bridged-ring-containing reactant other than solely as cyclic acid anhydride group Polyhydroxy-containing compound or salt thereof having an ether-oxygen atom as reactant Acyclic ether-oxygen compound Two or more carboxylic acid or derivatives or mixtures thereof Cycloaliphatic ring-containing reactant (other than aryl) Aryl-containing carboxylic acid or derivative of an aryl-containing dicarboxylic acid Contains terephthalic acid or substituted forms thereof Preventing or removing reactor or processing equipment buildup Contacting with organic material With distilling or pressured reduction step to remove material, e.g., flashing, autorefrigeration, etc. Temperature maintaining, heating or cooling REMOVING AND RECYCLING REMOVED MATERIAL FROM AN ONGOING POLYMERIZATION ZONE TO A POLYMERIZATION ZONE Recycling monomer | |
