Abstract: An apparatus and a method for molding of polyester articles having low acetaldehyde content directly from a melt without intermediate solidification of the molten polyester. A melt to mold process is used wherein an acetaldehyde stripping agent is mixed into a polyester melt before devolatilization in a flash tank. The devolatilized polyester is pumped out of the flash tank and injected into a mold, thus forming a shaped article. The apparatus may include one or more flash tanks in one devolatilization line, or multiple devolatilization lines may be used stemming from one main polymerization reactor. The final shaped article should contain less than 10 ppm of acetaldehyde.
Type:
Grant
Filed:
October 24, 1997
Date of Patent:
November 9, 1999
Assignee:
Eastman Chemical Company
Inventors:
Marcus David Shelby, Lanney Calvin Treece, Max Lamar Carroll, Jr., Stephen Weinhold
Abstract: Disclosed herein is an esterification process characterized by the high dilution in situ addition of antimony catalyst compound and phosphorus stabilizer compound to the esterification reaction mixture. A high dilution polymerization process for producing antimony phosphate derivative-containing polymer is also disclosed. Further disclosed are high clarity polyesters containing sub visual antimony phosphate derivative particles.
Abstract: A process for producing polyester articles, which generates little or no polyester waste. The process provides esterification or transesterification of one or more dicarboxylic acids or their dialkyl esters, polycondensation to produce a high molecular weight polyester, and molding or shaping of the polyester for produce the desired product. Scrap produced during the molding process is recycled back to the esterification or transesterification or polycondensation portion of the process. Optionally, the scrap may also be recycled to intermediate steps prior to the molding operation.
Type:
Grant
Filed:
October 24, 1997
Date of Patent:
August 31, 1999
Assignee:
Eastman Chemical Company
Inventors:
Michael Paul Ekart, Max Lamar Carroll, Jr., Eric Gray Olsen, Lanney Calvin Treece