Phasing out MOCA with our MDI-based alternative
MOCA is commonly used in cast polyurethane processes as a crosslinker for prepolymers based on toluene diisocyanates (TDI). The European Union’s REACH legislation has categorized MOCA as a “substance of very high concern” (SVHC).
Given that MOCA may potentially be subject to greater regulation by the European Chemicals Agency (ECHA) in the near future, it could become harder and more expensive to source. That’s why our customer UW-ELAST has begun preparing to phase it out. They asked us to develop a high-performing alternative for their production lines that would be easy to process and improve the property profile of their applications.
The mechanical properties of TDI-based systems enable them to be used for a wide variety of applications. Systems based on methylene diphenyl diisocyanate (MDI) are equally as versatile, though they also offer benefits such as a large range of hardness and improved safety.
However, whereas TDI solutions facilitate a forgiving molding process that allows some margin for error, with MDI more care is required and it is necessary to respect the processing parameters. A switch to these systems therefore requires manufacturers to rethink the way their production processes are organized.
Covestro offered us a way to phase out MOCA that benefitted every aspect of our processing. The system based on Desmodur® MTX6076 not only makes it easier to handle the chemicals, it also allows us to enhance our molding process and it outperforms our previous TDI MOCA-based system.
After evaluating various alternatives, we established that MDI solutions offer the most advantages.
Our Desmodur® MTX6076 prepolymers are based on MDI isocyanates. These chemicals are less harmful to human health than MOCA and can be processed at below 50°C, so operators face less exposure to vapor emissions.
Desmodur® has an adjustable pot life and demolding time thanks to catalyst rate variations and offers a wide range of hardness. Our solution can be used to cast large volume parts and even outperforms MOCA-cured systems in terms of mechanical properties.
As trusted partners of UW-ELAST, we were able to demonstrate that these significant advantages make our innovative MDI-based system not only an ideal alternative, but also superior to conventional MOCA-cured systems.
We provided guidance and technical assistance to help UW-ELAST successfully switch from their TDI-based systems to our new MDI-based solution.
Key benefits
- Versatile: Large hardness range with the same components facilitates more applications.
- Wear-resistant: Better tear resistance and abrasion resistance compared to systems using MOCA.
- Flexible and fast: Adjustable pot life and shorter demolding times help to boost production.
- Cost-effective: Reduced heating costs thanks to low processing temperature.
- Safer: Less toxic raw materials and fewer vapor emissions for improved handling.
