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Polyurethane and Polyurea Corner |
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Your source for information on products, technologies, and news pertaining to the Polyurethane and Polyurea market. Polyurethane and PUR Corner is updated monthly. Click hereto view archived issues.
Technology Review 
Metal Carboxylate Catalysts for Polyurethane Formulations Tin is coming under intense scrutiny in Europe over its toxicity. Consequently, there is renewed interest in metal carboxylate catalysts that could replace tin catalysts such as dibutyltin dilaurate in polyurethane formulations. Typical metal carboxylates are based on: Bismuth - non-toxic (used in cosmetics and pharaceuticals)
- selective urethane gelling catalyst
- more selective than tin and provides better mechanical properties
- gradual increase of the viscosity (no induction period of low viscosity as mercury)
- acidity is a critical factor : acceleration of the reaction rate
- rapid gelling catalyst in polar media
Zinc
- long reaction time
- not a selective catalyst
- cross-linking catalyst : modification of the final network
- affords tack-free surfaces, eliminates substantially the tackiness
- synergistic activity with bismuth Catalysts
Bismuth & Zinc Combinations - Participates in cross-linking reactions of isocyanates
- Zinc can be added to Bi to extend gel time
- Zinc can introduce an induction time period before the increase of viscosity
Zirconium
- Better selectivity than DBTDL: less gassing, fewer pinholes, longer pot life, higher gloss
- Synergistic with zinc and bismuth
- Supports NCO/OH reaction
Which Products are used where?
| TPU |
Bismuth is used instead of Tin.
BiCAT 8108 is a good replacement for DBTDL | | Coatings |
Zn reduces tackiness,
Zr is recommended (less gassing, fewer pinholes) | | Adhesives |
BiCAT 8108M and BiCAT 8118 are good replacements for DBTDL
Bismuth is often used as co-catalyst with amine
| | Sealants |
Bismuth is used as co-catalysts with amine to replace Tin and Lead. | | Elastomers |
Bismuth cataylsts were developed for elastomer applications as gelling catalysts
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For a full listing of products, please click here
Please contact your Tri-iso Technical Sales Representative if you would like additional information or samples of any of the catalysts offered by Tri-iso. Alternatively, please send an email to service@tri-iso.com
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