Desmodur® VP. PU1921 N

Recommended storage temperature: 10 - 30 °C
Shelf life (ex works): 6 months if stored in sealed, moisture-tight containers.
DESMODUR VP.PU 1921 N is moisture-sensitive and should therefore always be stored in tightly sealed original containers. Prolonged storage at temperatures above 30 °C results in a reduction in quality as the product becomes increasingly cloudy due to the deposition of low-solubility sediment (dimer formation). If the recommended storage temperature is exceeded for a long period (especially if the temperature of the product rises to above
30 °C), or if the recommended shelf life is exceeded, a chemical reaction may take place. In addition to a reduction in the NCO content and an increase in viscosity, carbon dioxide in particular may be generated. The resultant increase in pressure may cause the container to swell or burst. Storage at above 30 °C considerably shortens the shelf life. Storage at below
10 °C results in crystallization. DESMODUR VP.PU 1921 N should under no circumstances be stored in crystallized form as this will promote the formation of insoluble dimers and it will no longer be possible to melt the product completely. Delivered product should be spot-checked for crystallization, and cooling to below 10 °C must be avoided. If DESMODUR VP.PU 1921 N has been transported or stored below 10 °C for a short time, the material must immediately be melted at 60 - 70 °C. The melting point and the time required for this should not be exceeded as this also significantly promotes dimer formation. The entire container contents must be melted and homogenized before the container is immediately sealed and cooled to the recommended storage temperature. There is no risk that quality will be affected should the product have crystallized briefly, but it can be expected that the shelf life will be reduced. The melted material should be used as soon as possible.

Moisture access should be prevented when taking product samples.