What is a Coalescing Agent?
About Citroflex™ from Vertellus
Vertellus™ is the leader in specialty chemicals that prides itself on being a Responsible Care® company for various consumer goods, agriculture, nutrition, fine chemicals, personal care, pharmaceutical, plastic, coatings, and industrial markets. As a lead supplier of natural-based citric acid esters in North America, Vertellus™ has the proprietary chemistry for sizing and coalescing agents that improve coating formulations.
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 used in paints and coating formulations.
A coalescing agent's primary role is to soften the polymer, allowing a solid uniform continuous film as the paint dries. They are stabilizers or temporary plasticizers that provide an even dispersion for polymer or resin. Coalescing agents help form polymeric films at ambient temperatures and stabilize the coating when the water or solvent evaporates.
| Leneta Card | Aluminum Panel |
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Why Citroflex™ Citric Acid Esters?
These natural citric acid esters provide excellent performance in coating and paint formulation used as a phthalate-free alternative to many other plasticizers. As bio-based raw materials, Citroflex™ Citric Acid Esters are biodegradable from microorganisms in the soil. They are non-VOCs (volatile organic compounds) and non-HAP (Hazardous Air Pollutant) that efficiently combine plasticization of polymers with both hydrophilic and lipophilic properties, low order of toxicity, and rapid biodegradability.
Criteria for selecting a Coalescent Agent
Compatibility
- The coalescent agent additives must be compatible with the base polymer of the paint or the coating formulation.
Efficiency
- Coalescent agents additives 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).
Evaporation Rate
- Coalescent agent additives with low evaporation rates are more effective coalescents, especially in formulations of water-based and low VOC coatings.
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 coalescent from evaporating with the solvent (water).
Why Citroflex™ Coalescing Agents for Your Paints and Coatings
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| Product | Chemistry | Abbr |
|---|---|---|
| Citroflex™ C2 | Triethyl Citrate | TEC |
| Citroflex™ A2 | Acetyltriethyl Citrate | ATEC |
| Citroflex™ C4 | Tri-n-butyl Citrate | TBC |
| Citroflex™ A4 | Acetyltri-n-butyl Citrate | ATBC |
