REAXIS® C320 (Dioctyltin Dilauryl Mercaptide), also commonly known as Bis(dodecylthio)dioctyltin or Dioctyltin didodecylmercaptide, is an octyl-based dialkyl organotin with added functionality. REAXIS® C320 has the characteristic reactivity of a Sn (IV) organotin catalyst with improved upfront delay and improved hydrolytic stability due to the presence of a ligand with thiol functionality. Used primarily in polyurethanes, REAXIS® C320 imparts more controlled reactivity versus standard metal carboxylates such as REAXIS® C218 (Dibutyltin Dilaurate), REAXIS® C216 (Dioctyltin Dilaurate), and REAXIS® C325 (Dimethyltin Dineodecanoate). Catalysts similar to REAXIS® C320 include, REAXIS® C319 (Dibutyltin Dilauryl Mercaptide), REAXIS® C214 (Dioctyltin bis-(isooctyl Mercaptoacetate) and its isomer, REAXIS® C416 (Dioctyltin bis-(2-Ethylhexyl Mercaptocetate)).
For more information, we invite you to read our technical bulletins on Iron Catalysts for Urethane Chemistries and Strategies for Improving Back-End Reactivity of Bismuth Carboxylate Catalysts.
Parameter | Range |
---|---|
Tin Content (%) | 15.7 - 16.8 |
Color (Gardner Number) | 5 Max |
Viscosity (cP @ 20°C) | 20 - 60 |
Density (g/ml) | 0.95 - 1.05 |
Unlike standard organotin carboxylates, sulfur-bearing organotins like Dioctyltin Dilauryl Mercaptide are primarily used as a catalyst for polyurethanes. Reactivity of catalysts such REAXIS® C320, tend to be inactive in silicone and esterification-related applications. As the sulfur ligand acts as a blocking agent, thermal deblocking is required to initiate the back-end cure. Thus, catalysts such as REAXIS® C3320 tend to perform best in adhesive, elastomer, and foam applications with adequate exotherms. For coatings applications, REAXIS® C320 can be used in baked cured systems in contrast to ambient cured systems.
As is typical of most organotin and inorganic tin catalysts, the specific ligand in addition to the tin metal concentration contributes a major influence on overall reactivity. This is specifically highlighted in regard to sulfur- bearing ligands. In general, these sulfur ligands impart improved front-end delay and hydrolytic stability versus standard tin carboxylates. Standard ligands include thiols, mercaptides and mercaptoacetates. Reactivity as defined by delay, thermal availability, hydrolytic stability, and final cure will depend on the specific ligand, tin content, alkyl group and, most importantly, other raw materials used in the specific polyurethane formulation. As REAXIS® C320 is a mercaptan based catalyst, its delay should be less pronounced compared mercaptoacetates such REAXIS® C416, REAXIS® C214, and REAXIS® C322. In regard to the reactivity of the various urethane reactions, catalysts such as REAXIS® C320 will selectively catalyze the isocyanate-polyol reaction, with less of an effect on the water reaction. REAXIS® C320 tends to give longer delay and slower reactivity versus its butyl analogue, REAXIS® C319.
REAXIS® C320 should be stored in the original packaging at moderate temperatures and kept from freezing. The container should be closed tightly after each use to maximize shelf life. Characteristic of most Sn (IV) organotins, the primary cause of instability would be hydrolysis. Although more stable compared to organotin carboxylates, long-term contact with moisture could result in hydrolysis with the formation of tin oxide insolubles leading to deactivation of REAXIS® C320.
Section | Hazard Class | Category | Hazard Statement |
---|---|---|---|
A.10 | acute toxicity (oral) | 4 | H302 |
A.9 | specific target organ toxicity - repeated exposure | 1 | H372 |
DOT | IMDG | ICAO | Environment Hazard | |
---|---|---|---|---|
UN Number | not assigned | not assigned | not assigned | non-environmentally hazardous acc. to the dangerous goods regulations |
UN Proper Shipping Name | not relevant | not relevant | not relevant | |
Transport Class | none | none | none | |
Packing Group | not assigned | not assigned | not assigned |
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.
Are you unsure of what you are looking for? We want to hear your story. Maybe we can become a part of it.
Speak With An Expert