Waterborne Coating Conversion
Moving a solventborne formulation to water breaks the additive package first. This is the order the pieces usually have to be replaced in.
The binder change is the part that gets planned. The additive package is the part that fails: dispersants that anchored in solvent have nothing to hold on to in water, surface tension goes up, foam appears where there was none, and the rheology profile that held a vertical film disappears. These six stages cover the replacements in the order they usually bite.
Waterborne Coating Conversion In 6 Steps
Rebuild the dispersion
Solventborne dispersants do not stabilise pigment in water, and colour strength collapses.
Move to a waterborne block copolymer. QK3770 and QK3755 are 40% active and VOC-free, QK3740 is 100% active where formulation space is tight, and QK3778 is the 60% active universal grade that also handles anti-corrosive pigments.
Fix the grinding procedure
A waterborne dispersant ground together with resin and amine loses most of its effect.
Grind in water alone, with no resin, amine or co-solvent present, then let down. This is stated on the QK3770 and QK3755 data sheets and it is the single most common waterborne conversion mistake.
Deal with surface tension
Water has high surface tension, so wetting fails on low-energy substrates and craters appear at speed.
QK706E lowers both static and dynamic surface tension, and dynamic is the one that matters on a fast wet film. Add it before pigment and filler so it also holds down mixing foam.
Deal with foam
Foam that never existed in solvent now slows the filling line.
QK706E suppresses foam as it wets, so one addition covers both. Check behaviour on the actual mixing equipment rather than in a beaker.
Rebuild the rheology
Waterborne systems settle and sag differently, and a solventborne thixotrope will not transfer.
QK4200 is the waterborne polyurea rheology additive, dosed 0.2-1% for anti-settling and 0.5-2% for anti-sag. It is post-addable, so a batch can be corrected rather than reworked.
Rebuild effect pigment orientation
Metallic and pearl finishes that looked right in solvent come out cloudy in water.
QK8521 is an EVA wax emulsion added at 5-10% at low shear after the effect pigment, with system pH raised to 9-9.5 first. QK8330 is the polyamide salt route at 1-5%, pre-blended with water at 4:1.
The Grades Referenced Above
QK3770 Wetting and Dispersing Agent
VOC-free block copolymer dispersant for waterborne wood and industrial coatings and resin-free concentrates.
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QK3778 Waterborne Dispersant
Universal waterborne dispersant at 60% active that handles every pigment class including anti-corrosive fillers.
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QK706E Wetting and Defoaming Agent
Gemini non-ionic surfactant that cuts dynamic surface tension and suppresses foam in waterborne coatings, inks and adhesives.
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QK4200 Liquid Rheological Agent
Liquid polyurea rheology additive for waterborne and water/glycol-ether systems, dosed for anti-settling or anti-sag.
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QK8521 Waterborne Aluminium Pigment Orientation Agent
VOC-free EVA wax emulsion that lays aluminium and pearl pigment flat in waterborne basecoats.
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QK8330 Waterborne Rheology Control Agent
Modified polyamide salt that orients effect pigments and stops settling in waterborne automotive and industrial coatings.
View technical dataWaterborne Coating Conversion Questions
What is the most common waterborne conversion mistake?
Which additives here are declared VOC-free?
Can the rheology be corrected after the batch is made?
Start On Waterborne Coating Conversion
Send the formulation details and the constraint you are working against. A recommended starting point with the matching data sheets comes back by email.