Polyisocyanates for high-performance polyurethanes : Desmodur®

Polyurethanes consist of two main components – polyols and polyisocyanates. By carefully selecting each raw material, an endless array of polyurethanes (PU) with wide-ranging properties is possible. Desmodur® from Covestro is proven as one of the highest quality polyisocyanate building blocks available.

We have been developing polyisocyanates since the 1940s. Today our comprehensive range of Desmodur® polyisocyanates for solventborne and high solids polyurethane (PU) coatings, adhesives and sealants offers tremendous formulating freedom.

In fact, polyurethane coatings based on Desmodur® polyisocyanates are used to protect many products we rely on every day such as:

• Cars, trucks and buses
• Appliances and electronics
• Wood furniture and cabinetry
• Interior and exterior walls, floors, window frames and more
• Bridges and other infrastructure
• Marine vessels
• Food packaging

The Desmodur® product line includes aromatic and aliphatic (light-stable) diisocyanates, polyisocyanates and prepolymers for the formulation of one- (1K) and two-component (2K) polyurethane systems. Our isocyanate chemistries include:

• Diphenylmethane diisocyanate (MDI)
• Toluene diisocyanate (TDI)
• Hexamethylene diisocyanate (HDI)
• Isophorone diisocyanate (IPDI)
• 4,4- dicyclohexyl methane diisocyanate (H12MDI)

Desmodur® quix crosslinker can reduce curing times for adhesives from two weeks to just two days – safely. These polyurethane building blocks for adhesives represent a new definition of time in high-performance flexible packaging for food safety.

Desmodur® eco N is a new nonsolvent aliphatic polyisocyanate PU crosslinker with significant (as much as 70 percent) renewable content and excellent performance. It is based on a new aliphatic isocyanate pentamethylene diisocyanate (PDI). PDI is an entirely new isocyanate that offers customers a hardener component based on renewable feedstock and with improved carbon footprint.

Desmodur® blulogiq provides a faster curing of 2K PU coatings for plastic parts and to raise the efficiency of the postcuring process. It also allows for a low-temperature curing on metal substrates, resulting in energy savings and enabling the coating of multi-material substrates on the same line. These capabilities allow for more efficient processing without sacrificing appearance.

At the heart of the technology is a thermolatent hardener Desmodur® blulogiq that separates film formation from curing. The coating initially flows smoothly on the substrate and forms an even film. When the temperature rises to approximately 80^o C the hardener activates and dries rapidly on the plastic substrate. Separation of film formation and curing enables perfect appearance of high gloss coatings. No significant changes to the coating formulation are required.