Recently, water-based industrial paint makers report frequent fish-eyes and craters after adding silicone leveling agents. Initial blame falls on contamination, but the real culprit is surface tension mismatch.
Acrylic resins typically exhibit surface tension of 30–40 mN/m, while conventional polydimethylsiloxane (PDMS) silicones sit at just 18–22 mN/m. When this gap is too wide, silicone migrates aggressively to the air-film interface, over-spreading and triggering micro-phase separation. The result: localized retraction and crater formation, especially under fast-drying conditions.
Experts stress that compatibility—not mere addition—is key. Polyether-modified silicones, with adjusted surface tension (24–28 mN/m), offer better harmony with aqueous systems. Precise dosing and high-shear dispersion further reduce defect risk. As one formulator noted, “It’s not about using silicone—it’s about using the right one.”
