Microtalc Talc Talc Specialty Minerals Extenders / Fillers >> Talc or Magnesium Silicate Rheology Modifiers / Thickeners >> Mineral SEALANT ADHESIVE The platy particle shape and highly oleophilic surface of MICROTALC® talc enhances its use in adhesive and sealant systems as a thixotropic building additive and functional filler. MICROTALC® talcs are available in a wide range of particle size distributions that allow formulators to maximize the materials' utility and cost benefit. Talc. Possesses platy particle shape and highly oleophilic surface. Used as thixotropic additive and functional filler in adhesives and sealants.