German technical background VOK-430 Rheological agent Used to improve sagging resistance and anti-settling properties in solventborne coatings replaces BYK-430

German technical background  VOK?-430 rheological agent

VOK?-430 liquid rheology agent for solventborne coatings, adhesives and sealants to improve anti-sag and anti-settling properties.

Product information 

Chemical composition 

High molecular weight urea modified medium polar polyamide solution 

Typical physicochemical data 

The data presented on this data page is typical and not a product specification. 

Density (20 °C): 0.86 g/ml 

Refractive index (20 °C): 1.43 

Non-volatile: 30% Solvent: isobutanol/solvent oil 9/1 

Flash point: 27 °C 

Storage and transportation 

At storage and transport temperatures below 10 °C, the product may delamination or turbidity. When the additive is added at a dispersion temperature of not less than 50 °C, its effectiveness is not affected. 

Application areas 

Coatings industry, adhesives and sealants 

Product features and benefits 

With the help of pigments and fillers, the additive produces a three-dimensional network structure. The entanglement of high molecular weight polymers can form pseudoplastic rheological behavior. Both the polarity of the system and the temperature at the time of addition affect the rheology. The rapid regain of viscosity after shear prevents the settling of pigments and fillers and produces good sag resistance. The additive has no "prosthesis effect", no adverse effect on interlayer adhesion, liquid form, easy to process.

Recommended dosage 

0.1-1.5 % of total formula (supplied form) for improved anti-settling. 

1-3 % of total formulation (supplied form) for improved stability. 

The above recommended dosage is for reference, and the appropriate dosage needs to be determined through a series of tests. 

Addition method and processing guidance 

VOK?-430 is added to the abrasive when dispersing pigments/fillers to achieve good results. This stage usually raises the temperature to 40-50 °C, which produces good results; There are no adverse effects on increasing the temperature.

It can be added later under normal stirring conditions at low shear rates, but only for binder systems of suitable polarity, and the additive must not be lower than 10 °C at any time. If the required temperature is not reached, it is only recommended to add to the abrasive of the coloring/filling system at least 50 °C. 

Special considerations 

The interaction of this additive with pigments and fillers can lead to an increase in viscosity and a decrease in gloss. Wetting and dispersing additives are used to ensure the stability of solid particles and thus avoid this effect.