Desmodur® VP.PU 20RE15

DESMODUR VP.PU 20RE15 is a modified isocyanate based on diphenylmethane-4,4'-diisocyanate. It is a solvent-free liquid which is slightly yellowish and of low viscosity at room temperature. It crystallizes at lower temperatures.It can be used in conjunction with polyols for the production of polyurethane products.

Exposure to moisture must be prevented when taking product samples.

Storage in original sealed Covestro containers.Recommended storage temperature: 20 – 25 °CProtect from moisture, heat and foreign material.Covestro represents that, for a period of 6 months following the day of shipment as stated in the respective delivery documents, the product will meet the values set forth in section "specification" above provided that the product is stored in full compliance with the storage conditions and is otherwise handled appropriately. The lapse of this period does not necessarily mean that the product no longer meets specifications. However, prior to using said product, Covestro recommends to test such a product if it still meets the specifications. Covestro does not make any representation regarding the product after the period and Covestro shall not be responsible or liable in any way for the product failing to meet specifications after the period.General information: The product 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 above70 °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 20 °C results in crystallization. The product 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 20 °C must be avoided. If the product has been transported or stored below 20 °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.Warning: If the recommended storage temperature is exceeded for a long period (especially if the temperature of the product rises to above 50 °C), or if the recommended shelf life is exceeded, or if the product comes in contact with water or bases such as amines, alkalis or metal compounds, 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 containers to swell or burst. Consequently, if the product is mixed with other components or processed into a prepolymer, it is advisable to check the shelf life of the mixture or prepolymer.

Complete exclusion of moisture is vital during compounding, transfer, etc., as even extremely small traces of moisture have an adverse effect on the shelf life. It must be ensured that the containers – including empty ones –are always tightly sealed. In particular, the product should never be allowed to come into contact with water, which reacts with DESMODUR VP.PU 20RE15 to form polyureas with liberation of carbon dioxide. Contact with water in any form (damp containers, water-containing solvents, moist air) must therefore be prevented during storage, transfer and processing ofDESMODUR VP.PU 20RE15. Failure to do so may lead to a dangerous build-up of pressure in tanks and containers due to the evolution of carbon dioxide. In addition, polyureas forming in DESMODUR VP.PU 20RE15 may cause the deposition of solids, leading to blockages and faults in filters, pumps and pipelines of the processing plant. If DESMODURVP.PU 20RE15 comes into contact with bases such as amines, alkalis or metal compounds, chemical reactions may occur. As a result, in addition to a reduction in the NCO content, an increase in viscosity and the precipitation of solids, carbon dioxide in particular may be generated, leading to an increase in pressure inside sealed containers. Consequently, if DESMODUR VP.PU 20RE15 is mixed with other components or processed into a prepolymer, it is advisable to check the shelf life of the mixture or prepolymer.