Citroflex® is a range of citric acid esters from Vertellus with multiple functionalities and performance benefits for polymer systems. Citroflex® products are commonly known as plasticizers and plastics additives, but they are also very effective coalescing agents when used in paints and coating formulations.
What is a Coalescing Agent?
A coalescing agent's primary role is to soften the polymer, allowing a solid uniform continuous film as the paint dries. It acts as a stabilizer or a temporary plasticizer that provides an even dispersion for the polymer or the resin. Coalescing agents help with the formation of polymeric films at ambient temperatures and stabilize the coating when the water or solvent evaporates.
Criteria for selecting a Coalescent Agent
The coalescent agent must be compatible with the base polymer of the paint or the coating formulation.
Coalescent agents are used to decrease the MFFT of the polymer-coalescent system. The coalescing aid is selected based on the base polymer glass-transition (Tg) temperature, which defines the baseline minimum film formation temperature (MFFT).
Coalescent aids with low evaporation rates are much more effective coalescents, especially in water-based and low VOC coatings formulations.
Water and Polymer Solubility Balance
It is vital to select a coalescent agent with low water solubility and high polymer solubility. The optimal solubility ensures the film formation stability and prevents the coalescents from evaporating with the solvent (water).
Why Citroflex® Coalescing Agents for Your Paints and Coatings
Low evaporation rate and Low VOC of < 0.5%
Exceptional efficacy in Tg recovery
Excellent hardness development and superior anti-blocking properties
Broad compatibility with polymers, binders, and a variety of substrates
Resistance to dirt pick-up and staining for paints and coatings
Nontoxic and Eco Complaint: not classified as VOC material in Europe (1999/13/EC) and 2004/42/CE) and not as HAP in the U.S. (Clean Air Act 1990)