The invention relates to a preparation method of
polyethylene therephthalate used in an
antimony-free environmentally-friendly
bottle. The technical process of the technology is that: fine
terephthalic acid and
ethylene glycol are stirred in a
slurry mixing can, are pumped into a
slurry feeding can, and then enter an esterification kettle through a
slurry injection
nozzle to generate
oligomer. Additives on
siphonium line of the esterified
oligomer are injected into a prepolymerization kettle through a pump and materials, after reaching the top of the prepolymerization kettle, and flow to a final
polymerization kettle. The method is characterized in that the additives on a pipeline from the
oligomer and into the prepolymerization kettle comprise a catalyst, a stabilizer and a dispersant, wherein, the catalyst is
titanium-
cobalt composite catalyst, the stabilizer is polyphosphoric acid and the dispersant is cage-type
silsesquioxane; a
pipe reactor is arranged on the pipeline from the oligomer and into the prepolymerization kettle, the additives are dissolved respectively in
ethylene glycol to prepare a mixture liquid, the mixture liquid, after being fed into the can, is injected into the pipeline from the oligomer and into the prepolymerization kettle by using the
nozzle, and enters the prepolymerization kettle after being mixed evenly in the
pipe reactor. The preparation method is excellent in decentrality and low in b value.