Zinc phosphate

Zinc phosphate (CAS 7779-90-0, EC 231-944-3) is an inorganic zinc salt also known as zinc orthophosphate, C.I. Pigment White 32, and C.I. 77964. It carries no E-code designation and is not classified as a food additive. The molecular formula is H3O4P·3/2Zn.

In anticorrosive coatings, zinc phosphate acts as a passivating pigment by reacting with moisture to form a protective phosphate layer on metal substrates, slowing electrochemical corrosion. In construction adhesives and sealants, it functions as a pH buffer, stabilising formulations against alkaline degradation. It also provides antimicrobial activity in treated textiles and leather through zinc ion release.

Zinc phosphate is available in standard powder grades and supplied under REACH compliance for the European market. Producers offer technical and pigment-grade material, with documentation typically including SDS and CoA aligned to customer specification requirements. Standard packaging formats include 25 kg bags and bulk quantities on request.