Patent · US Expired

Process of recovering components from scrap polyester

US5298530A · kind A · utility

29Cited by
8References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 25, 1992
Grant dateMar 29, 1994
Priority date
Expiry dateNov 25, 2012

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02W30/62
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

A process of recovering components such as ethylene glycol and dimethylterephthalate from scrap polyester. The process steps are: (a) introducing oligomers of ethylene glycol and terephthalate acid or dimethyl terephthalate to a first vessel and heating the oligomers; (b) introducing scrap polyester to the first vessel and forming a startup melt with the oligomers; (c) transferring melt from the first vessel to a second vessel; (d) passing super-heated methanol through the melt in the second vessel to form a final melt comprising low molecular weight polyesters and monomers; (e) transferring final melt from the second vessel to the first vessel; and (f) recovering components from the second vessel.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.