Zinc Borate
Zinc Borate 3.5 hydrate (CAS 1332-07-6), 45–48% B2O3, supplied wholesale by Zyntex. Halogen-free flame retardant synergist and smoke suppressant for PVC, cables, plastics, coatings and wood composites. CoA and SDS with every lot.
Description
Zinc Borate Product Overview
The most common commercial zinc borate has the composition 2ZnO·3B2O3·3.5H2O. It is a white, fine powder that does not dissolve in water. Because it keeps its water of crystallization up to about 290°C, compounders can process it in most plastics without decomposition.
In a fire, it releases water, forms a glassy protective layer and promotes char formation. As a result, it reduces smoke and afterglow. It rarely works alone: compounders combine it with Aluminum Hydroxide, with Melamine cyanurate or other nitrogen-phosphorus systems, or with halogenated flame retardants as a partial replacement for antimony trioxide. Typical applications include PVC, polyolefins, cables, rubber and coatings.
Wood composite producers also use it as a preservative against fungi and insects in OSB and particleboard. For other boron compounds, see Boric Acid and Barium Metaborate.
Key Applications of Zinc Borate
Main application areas:
🔌 Cables and PVC
Flame retardant synergist and smoke suppressant.
🏭 Plastics and Rubber
Synergist with ATH and halogen systems in compounds.
🎨 Coatings
Fire-retardant and anti-corrosion additive.
🪵 Wood Composites
Preservative against fungi and insects in OSB and particleboard.
Zinc Borate Technical Specifications
| Parameter | Standard Value |
|---|---|
| Product Name | Zinc Borate (3.5 Hydrate) |
| CAS Number | 1332-07-6 / 12767-90-7 |
| B2O3 Content | 45.0% – 48.0% |
| ZnO Content | 37.0% – 40.0% |
| Refractive Index | 1.58 |
| Appearance | White fine powder |
| Documents | CoA and SDS with every lot |
⚠️ Safety & Handling: Very toxic to aquatic life with long-lasting effects, and boron compounds may be classified as toxic for reproduction. Avoid dust formation and ingestion, and wear gloves, eye protection and dust protection. Prevent release to the environment and store in tightly closed bags in a dry place. Always consult the Safety Data Sheet (SDS) for full classification and handling instructions.
Frequently Asked Questions
Why is zinc borate used together with other flame retardants?
It works best as a synergist. It strengthens char formation and reduces smoke and afterglow when combined with aluminum hydroxide, nitrogen-phosphorus systems or halogenated flame retardants.
Can zinc borate replace antimony trioxide?
In many halogenated formulations it can partly replace antimony trioxide while also lowering smoke. The optimal ratio depends on the polymer and the target fire standard.
How can I get a price and documents?
Prices depend on quantity, packaging and destination. Contact us with your required volume to receive a quotation together with the CoA and SDS.
