Soil release promoting pet-poet copolymer, method of producing same and use thereof in detergent composition having soil release promoting property

摘要

A soil release promoting copolymer of polyethylene terephthalate and polyoxyethylene terephthalate (PET-POET) having a weight average molecular weight in the range of 15,000 to 35,000, and a PET:POET molar ratio of about 2:1 to 6:1, is prepared by reacting polyethylene terephthalate with polyethylene glycol in the presence of a catalyst system including both antimony trioxide and calcium acetate or both titanium isopropoxide and sodium isopropoxide. The PET-POET copolymer provides improved soil release properties for oily and greasy stains from polyester fabrics at high and low wash temperatures and is stable even at high alkalinity levels. The starting PET can advantageously be obtained from scrap bottles.