Borate Free
Since many years the starch adhesive suppliers for the corrugated board industry are trying to replace hazardous boron compounds. Boron derivatives, like borax, amino borate or boric acid are classified by the European Chemical Agency as Substances of Very High Concern suspected of damaging fertility and the unborn child, are formulated in the glue to make corrugated boards.
C-IP's Patented technology enables the use of acrylic polymers in starch-based adhesives. These polymers cross-link with the starch but also with AZC.
Resulting in a 100% borate-free adhesive formulation.
Patented formulation based on specific acrylic polymers cross-linked with AZC (Ammonium Zirconium Carbonate), enables great rheological behavior, high level shear-thinning, excellent water retention, a very stable viscosity and very short adhesive's structure, without classified borates.
Ammonium Zirconium Carbonate (AZC) is an alkaline solution of anionic hydroxylated zirconium polymers. AZC is a highly effective crosslinker for use in paper manufacturing and surface coatings.
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.
As an effective inorganic cross-linking agent, the zirconium salts can form complexes and crosslink starch. Combined with Carrier Gel polymers it generates a 'double' crosslink. First with the starch, second with the acrylic polymers.
This unique formulation results in a high thixotropic adhesive with zero borates.
A thixotropic fluid is a fluid which takes a finite time to attain equilibrium viscosity when introduced to a steep change in shear rate. Some thixotropic fluids return to a gel state almost instantly, such as ketchup, and are called pseudoplastic fluids.
For corrugated board production this results in a very thin glue film at the top of the fluting.