Tin octate T9 T-9 (divalent tin octate) is the main catalyst for the production of polyurethane foam., silicone rubber cured at room temperature, polyurethane rubber, polyurethane coating catalyst. The chemical properties are extremely unstable and easily oxidized.. The English name is Stannous octoate The chemical formula is C16H30O4Sn Molecular weight 405.1 CAS registration number 301-10-0 Density 1.251 The main tin content is 28+/-0.50%