Mondur® 3694

Mondur 3694 isocyanate must be stored in tightly closed containers and protected from contamination with moisture and foreign materials, which can adversely affect processing. It will react slowly with water to form polyureas and carbon dioxide gas, which may cause sealed containers to expand and rupture. Long term storage temperatures should be maintained at 18° to 30°C (64° to 86°F). For additional questions on storage and handling, please contact your Covestro Technical Service Representative.
Mondur 3694 isocyanate must not be allowed to freeze. Exposure to temperatures less than 18°C (64°F), can result in the formation of solid material. During the winter months, appropriate precautions must be taken during shipment and storage.
If solids form because of exposure of Mondur 3694 isocyanate to low temperatures, it may be possible to reliquify the product by heating. Use a well-ventilated oven for the minimum time necessary to render it clear. The temperature of the product should not exceed 60°C (140°F).
Agitation or drum rollers are recommended to avoid excessive local heating, which will degrade the product. The use of drum heaters is not recommended since the excessive heating causes dimerization, loss of NCO, and an increase in viscosity. As a result, the re-melted product may be cloudy, and the processing behavior and/or properties of the final product may be affected.
Prolonged storage of solid or partially solid Mondur 3694 isocyanate may result in the formation of MDI dimer in amounts that exceed its solubility in the product at normal storage temperatures. This can make the product unusable.
The shelf life is six months after receipt of material by customer, when stored in sealed original containers under conditions stated above.