Reaxis®  C248D - Dibutyltin Oxide/ Plasticizer Blend

REAXIS® C248D (Dibutyltin Oxide + Plasticizer) is a liquid version of dibutyltin oxide (DBTO) containing a phthalate-based plasticizer.  REAXIS® C248D contains 50% of the active tin catalyst content compared to the solid version of DBTO, REAXIS® C248. Other liquid versions using phthalates as the diluent include REAXIS® C248DP and REAXIS® C248DN. Liquid versions of DBTO-based silanes include REAXIS® C248VM and REAXIS® C248T. Other liquid grades are available upon request.  

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Technical Information

  • Product Category Organotin

  • Chemical Name Dibutyltin Oxide/ Plasticizer Blend

  • CAS Number 818-08-6

Typical Specifications

Parameter Range
Tin Content (%) 23.0 - 25.0
Refractive Index (nD @20°C) 1.5028 - 1.5109
Density (g/ml) 1.160 - 1.220
Color (Gardner Number) 4

International Regulatory Listings

  • TSCA (US) Yes

  • DSL (Canada) Yes

  • AICS (Australia) Yes

  • KECI (South Korea) Yes

  • IECSC (China) Yes

  • ENCS (Japan) Yes

  • TCSI (Taiwan) Yes

  • NZloC (New Zealand) Yes

  • PICCS (The Philippines) Yes

  • REACH (EU) No

  • NDSL (Canada) No


REAXIS® C248D and its alternatives can be used as a homogeneous catalyst in a wide spectrum of silicone and polyurethane applications including adhesives, sealants, and elastomers. Silicone-based applications include: acetoxy-, ethoxy- and oxime-based Room Temperature Vulcanizing (RTV) adhesives and sealants, polyethylene crosslinked silanes (PEX), and select silane modified polymers (SMPs). In regard to polyurethanes, REAXIS® C248D is typically used in adhesive, sealant, or elastomer formulations given the presence of a plasticizer.  


Given its high tin content, liquid form, and good compatibility with a wide range of raw materials, REAXIS® C248D tends to be a highly reactive catalyst across a broad range of silicone and polyurethane formulations. In regard to silicone reactions, REAXIS® C248D, like all tin-based catalysts, will catalyze the silanol/silane condensation reaction thus acting as both a polymerization and crosslinking catalyst. Typical of the organotin family of catalysts, REAXIS® C248D will catalyze most polyurethane reactions; it is primarily selective toward the polyol-isocyanate and water-isocyanate reactions. REAXIS® C248D is hydrolytically stable within typical formulation moisture levels, but this stability will break down with increasing moisture content.  

Package & Storage

  • 44 lb (20 kg) pails
  • 485 lb (220 kg) drums
  • 2425 lb (1100 kg) IBC

REAXIS® C248D should be stored in the original packaging. The container should be closed tightly after each use to maximize shelf life.

Safety and Handling

Before use of Reaxis products please refer to the relevant Safety Data Sheet (SDS) for safety and toxicological data as well as for the information on proper transportation, storage, and use. SDSs are available by request via our web site, contacting your local representative, or emailing direct to

This information is provided to the best of our knowledge but without obligation. Reaxis is not liable for any incorrect or missing information. This data sheet becomes invalid upon publication of a new version. Please contact us for the latest version.

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