Features of Antimony Trioxide as Catalysts

Antimony compounds are excellent catalysts to accelerate the polymerization in polyester manufacturing.
Antimony trioxide is the most widely used polymerization catalyst in both domestic and overseas markets in the manufacture of polyethylene terephthalate(PET)from ethylene glycol(EG)and high purity terephthalic acid(TPA), or dimethyl terephthalete(DMT).
PATOX-C and PATOX-CF when used as polymerization catalysts have the following excellent physical properties.

  1. PATOX-C & -CF for use in polyester when it is required to be stable in heat. They are high purity products low in metallic impurities to safeguard against undesirable side-reactions in the manufacturing process.
  2. PATOX-C & -CF contain less insolubles when dissolved in ethylene glycol. This leads to lower production maintenance requirements by minimizing the clogging of filter taps, and also minimizing operation interruption by reducing yarn cuts in polyester yarn production.
  3. PATOX-C & -CF are produced in large homogeneous lot sizes with precise production standards and controls. This provides a stable quality product which facilitates the production of a polyester with high transparency and sharp coloring.
  4. PATOX-CF, a finer type of PATOX-C, dissolves into ethylene glycol at lower temperatures.

Catalyst grade of antimony trioxide should be used in accordance with the above process.

(A): CAT(Catalyst) dissolving tank 
(B): CAT storage tank 
(C): CAT measuring tank 
(D): Slurry preparing tank 
(E): Slurry storage tank

Preparation-methods of catalyst

  1. EG and catalyst are placed into CAT dissolving tanks(A).
    Concentration of Sb2O3 is around 2.0% (To maintain fixed concetration)
  2. The catalyst is dissolved by heating and stripping at 130-180℃ for 3-6 hours, cooled to 50-70℃, and then transferred to CAT storage tank(B).
  3. A fixed quantity of solution is charged to CAT measuring tank(C), and then transferred to Slurry preparing tank(D).