Transesterification process using lanthanum compound catalyst
Patent 5840957 Issued on November 24, 1998. Estimated Expiration Date: 
March 16, 2018. 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 16, 2018. 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 2820023 3489722 3532671 3671379 3847873 Rare earth metal coordination compounds as lactone polymerization catalysts Patent #: 5208297 InventorsAssigneeApplicationNo. 042525 filed on 03/16/1998US Classes:560/92Preparing esters by ester interchangeExaminersPrimary: Barts, SamuelInternational ClassC07C 067/02AbstractThis invention relates to an improved transesterification process for the preparation of bis(3-hydroxypropyl) terephthalate monomer from 1,3-propanediol and a dialkyl terephthalate using a lanthanum compound transesterification catalyst.Other References
Field of SearchPreparing esters by ester interchange |
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