Antimony Trioxide, Antimony Trioxide Masterbatch, Diantimony Trioxide, Antimony Oxide EVA, ATO, 1309-64-4, 1327-33-9

Antimony Trioxide, Antimony Trioxide Masterbatch, Diantimony Trioxide, Antimony Oxide EVA, ATO, 1309-64-4, 1327-33-9

ANTIMONY TRIOXIDE (Sb₂O₃)

1. PRODUCT DEFINITION AND CHEMICAL IDENTITY

Note: Antimony trioxide is the most widely used antimony compound in industry. It plays a critical role primarily as a flame retardant synergist, as well as in catalyst, glass-ceramic opacifier, and pigment applications. It is an inorganic compound with an amphoteric character and high thermal stability.

2. PHYSICAL AND CHEMICAL PROPERTIES

3. FLAME RETARDANT MECHANISM AND FUNCTIONAL PROPERTIES

Antimony trioxide is not a flame retardant on its own. It operates through a strong synergistic effect with halogenated compounds. This mechanism exponentially increases flame retardancy efficiency.

• Halogen Release (200–300 °C): The halogen source in the polymer matrix (e.g., brominated flame retardants, PVC) releases HX (HCl, HBr) upon thermal decomposition.

• Antimony Trihalide Formation: Sb₂O₃ reacts with HX: Sb₂O₃ + 6 HX → 2 SbX₃ + 3 H₂O

• Gas Phase Radical Trapping: The formed SbX₃ acts as a radical scavenger, trapping the high-energy H• and OH• radicals that sustain the combustion chain reaction, thereby suffocating the flame.

• Solid Phase Barrier: A portion of the SbX₃ condenses on the surface, forming a protective char layer that acts as a barrier, inhibiting oxygen diffusion and heat transfer.

Thanks to this synergy, high-performance ratings like UL94 V-0 can be achieved with only 4–8% Sb₂O₃ + halogenated flame retardant by weight of the polymer.

4. COMMERCIAL FORMS AND COMPARISON

Antimony trioxide is available in two main commercial forms:

5. SECTORAL APPLICATIONS AND USAGE RATES

6. ALTERNATIVES AND COMPARISON

Important Note: No single alternative is a direct "drop-in" replacement; formulation optimization is mandatory for each system.

7. SAFETY, TOXICOLOGY, AND REGULATIONS

• GHS Classification (EU CLP):

  • Signal Word: Warning

  • Hazard Statements: H351 (Suspected of causing cancer), H332 (Harmful if inhaled).

• IARC Classification: Group 2B (Possibly carcinogenic to humans). Lung tumours observed in animal studies via chronic inhalation.

• Occupational Exposure Limits (8-hour TWA): ACGIH: 0.5 mg/m³; EU Directive 2019/1831: 0.5 mg/m³ (respirable fraction).

• REACH (EU): Listed as a Substance of Very High Concern (SVHC); authorization may be required for specific uses.

• Transport: ADR/RID Class 6.1 (Toxic substances), UN No 1549.

• Storage: Store in a cool, dry, and well-ventilated area, in tightly sealed packaging. Avoid dust formation.

• Personal Protective Equipment (PPE): When working with the powder form, use a P3 particulate filter respirator, safety goggles, and gloves. The masterbatch form eliminates dust exposure.

8. QUICK REFERENCE TABLE