Nytal 400 Hydrous calcium magnesium silicate mineral mixture R. T. Vanderbilt Extenders / Fillers >> Calcium silicate Extenders / Fillers >> Talc or Magnesium Silicate Rubber - Elastomer (Chloroprene, Butyl …) Natural rubber (NR) SEALANT Used as fillers and extenders in specialized applications in NR and synthetic rubbers, sealants and mastics, especially latex compounds. NYTAL ® 400 Hydrous calcium magnesium silicate mineral mixture NYTAL 400 is a super fine talc pigment. Suggested for use in high paint fineness and film smoothness, such as semi-gloss paints. Used as filler and extender for natural and synthetic rubbers in specialized applications. Super fine talc pigment. Used as filler and extender in NR and synthetic rubber, sealants and mastics.