Application of 2-carboxyethyl (phenyl)phosphinic acid as phosphorus-containing flame-retardant on PET

Phosphorus-containing flame-retardant coPET is prepared using 2-carboxyethyl(phenyl)phosphinic acid as flame-retardant on 4 000 t/a semi-batch polyester plant.Compare with the adding method of flame-retardant,the results showed that the method that solution of flame retardant in EG,added after esterification and before polycondensation is superior to the method that solution of flame-retardant in slurry.It is suitable for the flame-retardant without drying.