REAXIS® C248 (Dibutyltin Oxide) is a dialkyl organotin typically used as an esterification catalyst. Commonly referred as DBTO or Dibutyloxotin, REAXIS® C248 is characterized by a high tin content (~ 48%) and oxide ligand which imparts both high reactivity and high- temperature stability. REAXIS® C248 is supplied as a solid and can be supplied as a stable liquid with suitable diluents such as plasticizers and silanes. Related liquid-grade versions include REAXIS® C248D, which includes a plasticizer and a relatively high tin content, REAXIS® C248DP, which contains a plasticizer and lower tin content, REAXIS® C248DN, which also contains a plasticizer but has a lower overall tin volume, REAXIS® C248T, which contains a silane complex, and REAXIS® C248VM, which is another variant of our DBTO and silane compound. These liquid versions are used as catalysts for silicone condensation reactions. REAXIS® C248LC is a solid-grade version with improved particle size distribution and lower chloride content.
|Tin Content (%)||47.0 Min|
|Chloride (%)||0.2 Max|
|Loss On Drying (%)||0.5 Max|
REAXIS® C248 is primarily used as a homogenous catalyst for fatty acid -based saturated and unsaturated monomeric and polymeric esters. REAXIS® C248 can be used as a transesterification catalyst and is this used in the synthesis of alkyd resins. REAXIS® C248 and REAXIS® C248LC are used in electro-coat (E-coat) applications, where the latter is preferred given the more controlled particle size and lower chlorides. In its plasticizer and silane liquid forms, Dibutyltin Oxide DBTO is a good silicone condensation catalyst for adhesive, sealant, and coatings formulations, especially those formulations using silane terminated polymers (STPs).Alternative catalysts for esterification reactions include REAXIS® C220 (Monobutyltin Tris-(Ethylhexanaote)), REAXIS® C160 (Stannous Oxalate) and REAXIS® C129 (Stannous Octoate).
REAXIS® C248 has a few characteristics that make it a suitable catalyst for a wide range of high-temperature esterification reactions. These include a high active tin content, dialkyl content, and the presence of an oxide ligand. These characteristics result in a tin catalyst with good compatibility in a wide range of ester formulations, high reactivity leading to lower reaction times and the synthesis of low color end products, stability at typical reactions temperatures (180-230C), and hydrolytic stability in the presence of water generated during esterification.
REAXIS® C248 should be stored in the original packaging at moderate temperatures. The container should be closed tightly after each use to maximize shelf life.