Production of terephthalate esters by degradative transesterification of scrap or virgin terephthalate polyesters

摘要

A process for the production of terephthalate diesters having the following formula (I). ##STR1## Substituents R and R' are the same or different and represent a straight chain, branched or cyclic aliphatic group, an aromatic group, an alkaryl group or an aralkyl group, each group having from 6 to 20 carbon atoms. The process involves reacting a terephthalate polyester with a high molecular weight alcohol or a mixture of high molecular weight alcohols each having from 6 to 20 carbon atoms, in the presence of a catalyst and recovering the desired compound according to formula (I). This process is particularly useful for recycling scrap terephthalate polyester products such as those produced from polyethylene terephthalate (PET), crystallized polyethylene terephthalate (CPET), glycol-modified polyethylene terephthalate copolyester (PETG), polybutylene terephthalate (PBT), polycyclohexanedimethylene terephthalate (PCT), as well as the acid- and glycol-modified copolyesters of PCT, respectively PCTA and PCTG.