Epoxy Coatings CAB-O-SIL Fumed Silica

Application Overview

Formulating epoxy paints that provide protection against corrosion and mechanical stress requires a complex combination of resins, additives, solvents and pigments. Formulators face the challenge of balancing rheological performance, adhesion, corrosion resistance, aesthetic properties and cost of the final formulation. CAB-O-SIL fumed silica can help overcome such difficulties by offering sag and flow resistance in epoxy paints, anti-settling, anti-corrosive performance, storage stability (shelf life) and mechanical reinforcement.   In epoxy paints, excellent sag and flow resistance and anti-settling performance with a rheology control additive are desired. CAB-O-SIL fumed silica also improves resistance to environmental factors, particularly water, moisture and corrosion resistance. In addition, CAB-O-SIL fumed silica provides mechanical reinforcement and can improve film durability.  

Rheology Control

CAB-O-SIL TS-720 fumed silica provides an ideal rheological profile. At low shear stress, the model epoxy formulation exhibits high viscosity that prevents pigment settling and provides excellent sag resistance. Under high shear conditions such as mixing, spraying or rolling, model formulations containing CAB-O-SIL TS-720 fumed silica exhibit low viscosity that facilitates paint application.   Enhanced Protection The addition of a hydrophobic silica particle increases the mechanical strength and water-repellent ability of the paint. The addition of CAB-O-SIL TS-720 fumed silica increases hardness to the point where the paint withstands between 5H and 6H pencil hardness for proper epoxy control. This increase in hardness can be attributed to the presence of silica particles on the surface of the cured paint and the network they create within the paint.   Including CAB-O-SIL TS-720 at 1.5 mil dry film thickness in the paint prevents blistering after 400 hours of salt spray corrosion testing. The hydrophobicity of CAB-O-SIL TS-720 fumed silica prevents water from penetrating the paint and reacting with the substrate. Including CAB-O-SIL TS-720 at 1.5 mil dry film thickness in the paint prevents blistering after 400 hours of salt spray corrosion testing. The hydrophobicity of CAB-O-SIL TS-720 fumed silica prevents water from penetrating the paint and reacting with the substrate. Melisa Ataç / Chemist - Paint Chemicals Sales Engineer - Univar Kimya