StructureAmmonium zirconium carbonate (AZC)
CAS No. 68309-95-5
EC No. 269-682-7
Synonyms Diazanium zirconium(4+) dicarbonate dihydroxide; Diammonium bis(carbonato-O)dihydroxyzirconate; diammonium zirconium(4+) dicarbonate dihydroxide; diazanium zirconium(4+) dicarbonate dihydroxide; Zirconate(2-), bis(carbonato(2-)-kappaO)dihydroxy-, diammonium, (T-4)-; Zirconate(2-), bis(carbonato(2-)-O)dihydroxy-, diammonium

Ammonium zirconium carbonate (AZC)

Ammonium Zirconium Carbonate (AZC) is a clear alkaline stabilized solution, containing anionic hydroxylated zirconium polymers. AZC is an effective inorganic crosslinker and suitable for practically all types of paper and paperboard applications. AZC is totally formaldehyde-free.

Effective with all commonly-used binders Ammonium Zirconium Carbonate (AZC)​ reacts rapidly with binder functionality as water is released in the drying section.

The advantage of Ammonium Zirconium Carbonate (AZC) is that there is no need for elevated temperatures or extended cure time.

Tests have proven that the use of Ammonium Zirconium Carbonate (AZC) is improving printability, achieved by optimal water resistance, reduction of coating angle, uniform distribution of binders within the coating and open coating structure.

The use of Ammonium Zirconium Carbonate (AZC) does not effect the optical properties: there are no adverse effects on optical properties and there is no time or heat exposure yellowing.

Regulatory information

Ammonium Zirconium Carbonate (AZC) is approved under FDA (21 cfr. 176.170) and BfR (XXXVI)regulations as a component of paper and paperboard in contact with aqueous and fatty foods.

Ammonium Zirconium Carbonate (AZC)can be used in the temperature range 0 – 70°C.


Ammonium Zirconium Carbonate (AZC) can be added to a coating or size press formulation, interacting weakly with oxygenated sites, mainly carboxyl or hydroxyl groups on the binder molecules.

Removal of water and carbon dioxide during the drying stage drives the reaction to completion due to the generation of reactive zirconium cations.

Covalent bonds are formed and the reaction is irreversible under normal coating conditions. The reaction is not heat dependent. The dried coating will exhibit optimal water resistance but will remain hydrophilic in nature and the microporous structure of the coating surface will be "open" or unblocked.

Ammonium Zirconium Carbonate (AZC) reacts directly with the binders present in the coating or size press formulation.

Ammonium Zirconium Carbonate (AZC) functions by the generation of cationic zirconium resulting from decomposition during drying. Solids content is therefore not applicable to addition levels.


  • Dosage level

The recommended addition level for Ammonium Zirconium Carbonate (AZC) is in the range 5–7% on total dry binder content. Optimization needs to be determined empirically based on the degree of property enhancement required.


  • pH level

Ammonium Zirconium Carbonate (AZC) should never be subject to a pH below 7.

The recommended way to use Ammonium Zirconium Carbonate (AZC) in any formulation is to add it as the last ingredient in formulation.

All components of the mix should be combined and a final pH adjustment made, if necessary, to bring the formulation into the range of pH 7.5 – 10.


Packaging & Shelf Life:

  • IBC 1250 kg net
  • Bulk in isotank 


Under proper storage conditions the shelf life is 12 months.


Health & Safety:

Detailed information on the product described can be found in our relevant Health and Safety Information (Material Safety Data Sheet).​