The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 2001
Filed:
Nov. 04, 1998
Charles J. Maurer, Matthews, NC (US);
Gordon Shaw, Charlotte, NC (US);
Vicky S. Smith, Greenville, SC (US);
Arteva North America S.A.R.L., Zurich, CH;
Abstract
A pressure process for preparing a hydroxyalkyl ester monomer and oligomer that can be used to prepare a polyester such as polyethylene terephthalate (PET) is disclosed. The process includes the steps of reacting, by ethoxylation, dicarboxylic acid and alkylene oxide in the presence of a compressed gas medium to form a specified mixture of monohydroxyalkyl ester and bishydroxyalkyl ester. The reaction pressure is such that the density of the gas medium is greater than or equal to half the critical density of the compressed gas medium. The mole ratio of the alkylene oxide to the dicarboxylic acid is less than about 2:1, and preferably 1.1:1.2. The DP of all reaction products is less than 5. The reactant product may be polymerized into a polyester. The process may optionally employ catalysts such as amines or amino acids. The compressed gas medium can be a solvent and an optional cosolvent. The temperature of reaction is from about 100° C. to 240° C. at a pressure of 50-5000 psi.