Zinc Borate 2335

Zinc borate 2335 is a hydrated zinc-and-boron mineral additive for selected flame-retardant polymer systems. The 2335 designation describes the oxide and hydration ratio, 2ZnO·3B2O3·3.5H2O. It differs from anhydrous zinc borate and should be selected by hydrate form as well as CAS number.

The supply grade controls ZnO at 37–40%, B2O3 at 47–49%, bound water at 13–15.5% and D50 at 3–5 µm. Surface moisture and water of hydration are different measurements. The bulk-density unit is kg/m³; it must not be confused with the density of the solid itself.

PVC, polyolefin, polyamide and epoxy development should assess the mineral with the complete flame-retardant, filler and stabilizer package. Evaluate powder dispersion, processing, smoke production and the required final-article fire test. The additive alone cannot establish a flame rating or an electrical certification.

For elastomers, coatings and selected binder systems, evaluate compatibility, physical-property retention and exposure to moisture. Use dust control and prevent environmental release. The matched hydrated material is Class 9 dangerous goods, UN 3077; inorganic and non-flammable do not mean non-dangerous goods.

See related plastics and rubber chemicals in our catalog.