Brominated Flame Retardants for ABS, HIPS and Engineering Plastics
Flame Retardant Masterbatch: Benefits Over Powder Additives
Why antimony trioxide works
Antimony trioxide (ATO), CAS 1309-64-4, is not a flame retardant on its own. In the presence of a halogen source it forms antimony halides and oxyhalides in the flame, which scavenge radicals and interrupt combustion. This synergy means less brominated additive is needed.
Optimal bromine to antimony ratio
A bromine-to-antimony mass ratio near 3:1 is the classic optimum. For DBDPE at about 82% bromine, this translates to a DBDPE:ATO ratio of roughly 3:1 to 4:1. Going below a 2:1 bromine ratio wastes antimony; going far above it wastes bromine.
Particle size and quality
Finer ATO grades (around 0.3-1.5 micron) disperse better and give more consistent flame retardancy and colour. High-purity ATO above 99.5% Sb2O3 reduces discolouration in light-coloured compounds.
Frequently Asked Questions
What is the CAS number of antimony trioxide?
Antimony trioxide has CAS number 1309-64-4.
Is antimony trioxide a flame retardant by itself?
No. Antimony trioxide is a synergist. It boosts the performance of halogen flame retardants but has little flame-retardant effect on its own.
What is the best bromine to antimony ratio?
A bromine-to-antimony mass ratio of about 3:1 is the usual optimum for most brominated systems.
Need a quotation or technical data sheet?
Shandong Haiwang Chemical supplies brominated flame retardants, antimony trioxide and oilfield bromides worldwide. Tell us your product, grade, quantity and destination port and our team will reply quickly. Visit our products page or contact us — email mikeyang@haiwangchemical.com.