Hi-Mar DFC-21 Silica Hi-Mar Specialties Defoamer / Antifoaming agent >> Silicone-free >> Silica-based Acrylic/Acrylate Resins Vinyl General Industrial /Maintenance Dispersible in water Hi-Mar DFC-21 Organic/ Reacted Silica Defoamer Vinyl/ Acrylic 100% Acrylic Styrene/ Acrylic Traffic paint Organic reacted silica. Used as a defoamer for vinyl/acrylic, 100% acrylic and styrene/acrylic coatings and traffic paint.