Waterborne Conversion Additive Checklist

Check One: Is The Dispersant Built For Water

A solventborne dispersant has nothing to anchor with in water, and the symptom is colour strength that will not build however long the grind runs. Move to a waterborne block copolymer: QK3770 or QK3755 at 40% active and VOC-free, QK3740 at 100% active where formulation space is tight, or QK3778 at 60% active where anti-corrosive pigments are involved.

Check Two: Is The Grind Resin-Free

This single procedural point accounts for more failed waterborne trials than any chemistry choice. QK3770 and QK3755 both specify grinding in water alone, with no resin, amine or co-solvent present, then letting down afterwards. Resin competes with the dispersant for the pigment surface, and once it has won there is no recovering the grind.

Check Three: Has Surface Tension Been Addressed

Water has far higher surface tension than solvent, so substrate wetting that was never a question becomes one. QK706E lowers both static and dynamic surface tension, and it is the dynamic number that governs behaviour at line speed. Add it before pigment and filler.

Check Four: Where Will The Foam Come From

Foam that did not exist in the solventborne version will appear at mixing, at pumping and at filling. QK706E suppresses foam while it wets, so one addition covers both jobs. Test on the actual mixing equipment; a beaker will not reproduce the shear that generates the foam.

Check Five: Has The Rheology Been Rebuilt

A solventborne thixotrope will not transfer. QK4200 is the waterborne polyurea grade, dosed 0.2-1% for anti-settling and 0.5-2% for anti-sag, and post-addable so a batch can be corrected. Allow 2 to 24 hours before judging the result.

Check Six: Does The Formulation Have Effect Pigment

If it does, orientation has to be rebuilt too. QK8521 at 5-10% with system pH raised to 9-9.5 first, or QK8330 at 1-5% pre-blended with water at 4:1. Metallic conversions that skip this step come out cloudy and get blamed on the binder.