Carbodiimides: safer and more sustainable cross-linkers
Monday, 14 November, 2022
Diisocyanates are the most widely used cross-linkers in the polyurethane sector.
Nevertheless, as of 24 August 2023, any substance or blend for industrial or professional use which contains a concentration of more than 0.1% free diisocyanate will need to declare this on its label.
Moreover, all workers in said product’s chain of use will need to have been given specific training on the handling of said products. Also, the product labels should specify that it is necessary to have undertaken said training in order to be able to handle it.
As a result, as part of our commitment to offer more sustainable, environmentally friendly products, Comindex would like to introduce you to an alternative to the use of diisocyanates: carbodiimides.
What are carbodiimides?
Carbodiimides are organic compounds that include the functional group
[– N = C = N –]
The carbodiimide group reacts with carbonylic acid groups, allowing for cross-linking with resins containing these functional groups. Some examples include polyurethane dispersions, acrylic emulsions, water dispersible polyesters, etc.
They are safe, sustainable cross-linkers that are dispersed in water and do not add VOCs to the formulation.
At Comindex we are distributing these carbodiimides under the CARBODILITE range, manufactured by Nisshinbo.
Discover other benefits of using carbodiimides as cross-linkers
In addition to being environmentally friendly, additional noteworthy properties afforded by these products include:
High open time
Reaction at room temperature
No impact on flexibility
Anti-hydrolysis in resins containing ester links
All in all, carbodiimides act as a safe, environmentally friendly solution that allows for cross-linking between resins and carboxylic groups, as well as providing a host of additional properties.