What is Antimony Trioxide Used for

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When antimony reacts with air through heating, it forms an inorganic compound known as antimony trioxide. Antimony trioxide is one of the essential compounds of antimony. It is gray or white and exists in a cubic crystalline form. The compound is also known as Atox B, Atox E, Antimony white, Flowers of Antimony, Blue star RG, and Antimony (III) oxide.

Physical & Chemical Properties of Antimony Oxide

The inorganic compound has a density of 5.7 g cm3 and a vapor density of 10 (air = 1). The boiling point is 1425°C, and the melting point is 1425°C. The substance is only soluble with hydrolysis, where it forms an aqueous solution. However, it is marginally water soluble.

Antimony Trioxide Structure

The antimony trioxide structure varies depending on the temperature of the sample. For instance, dimeric Sb4O6 is discovered under high temperatures. The Sb4O6 molecules appear as bicyclic cages that look the same as related oxides of phosphorous trioxide and phosphorous (III). This cage structure is maintained in a cubic habit. A more stable orthorhombic form with pairs of Sb-O chains is discovered if the compound is exposed to temperatures below 606 °C.

Uses of Antimony Trioxide

Flame Retardancy

A significant amount of antimony trioxide produced annually goes to enhance flame retardancy. It is added to certain flame retardants, making them efficient in consumer products such as textiles, upholstered furniture, children’s products, and plastics.
In its physical state, antimony trioxide has no flame-retardant properties. However, when combined with other compounds, it acts as a synergist. Typically, it combines with halogenated compounds to create chemical compounds with flame retardant properties.

The process involves:

  • Stopping the thermal decomposition reaction under gas
  • Sealing against oxygen
  • The carbonaceous char is formed under the solid phase

PET production

Antimony trioxide is also used as a catalyst in producing polyethylene terephthalate (PET). Polyethylene terephthalate is a polymer commonly used in bottles, films, and synthetic fibers. It is also among the most popular materials in the beverage and food packaging industry. It is a suitable material because it is lightweight and impermeable to CO2.

As with other compounds in PET, antimony can be used to migrate water into the bottles. However, current legislation establishes migration limits for antimony trioxide and other compounds.

The amount of antimony used in the preparation of PET may range from 100-300 mg/kg. This implies that a one-liter bottle can contain 3-9 milligrams of antimony. The high amount shows that the set limits can exceed if total migration occurs. For that reason, further studies have been carried out to determine the leaching or migration of the substance.

Order Quality Antimony Trioxide Today

Bisley International has vast experience supplying quality raw materials to manufacturers worldwide. Whether you want to produce flame-retardant products or PET bottles or glass, we will deliver the antimony trioxide you need to meet the demand. Browse our website or contact us today for more information and place your order.

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