Reaxis®  C248T - Dibutyltin Oxide + Silane Complex

REAXIS® C248T (Dibutyltin Oxide + Silane) is a liquid version of dibutyltin oxide (DBTO) which contains a silane and is commonly used as a catalyst for silicone chemistries.  REAXIS® C248T contains 50% of the active tin catalyst content compared to the solid version of dibutyltin oxide, REAXIS® C248. Another DBTO-based silanes grade that we offer is REAXIS® C248VM. Liquid versions of REAXIS® C248 utilizing phthalates as a non-reactive diluent include REAXIS® C248DP and REAXIS® C248DN. Other liquid grades are available upon request.

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Technical Information

  • Product Category Organotin

  • Chemical Name Dibutyltin Oxide + Silane Complex

  • CAS Number 818-08-6

Typical Specifications

Parameter Range
Tin Content (%) 22.0 - 23.5
Color (Gardner Number) 3 Max
Density (g/ml) 1.0 - 1.2

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

  • NDSL (Canada) No

  • REACH (EU) No


REAXIS® C248T and its alternatives can be used as a homogeneous catalyst in a wide spectrum of silicone applications including adhesives & sealants, as well as 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). 


Given its high tin content, liquid form, and good compatibility with a wide range of raw materials, REAXIS® C248T tends to be a highly reactive catalyst across a broad range of silicone formulations. REAXIS® C248T, like all tin-based catalysts, will catalyze the silanol/silane condensation reaction, acting as both a polymerization and crosslinking catalyst. REAXIS® C248T is hydrolytically stable within typical formulation moisture levels, but this stability will break down with increasing moisture content.  

Package & Storage

  • 44 lb (20 kg) plastic pail
  • 440 lb (200kg) steel drum

REAXIS® C248T should be stored in the original packaging at moderate temperatures. The container should be closed tightly after each use to maximize shelf life. Given the presence of a silane, hydrolytic instability could occur resulting in reduced catalytic performance.

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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