Desmodur® BL 4265 SN

- Storage in original sealed Covestro container.

- Recommended storage temperature: 0 - 30 °C.

- Protect from moisture, heat and foreign material.

General information: The product is sensitive to moisture and should therefore be stored in its sealed original containers. Prolonged storage at temperatures above 25 °C results in a deterioration in quality as the product becomes increasingly turbid owing to the formation of a sediment (dimers) that is not readily soluble. For example, storage stability at 40 °C is limited to a maximum of 4 months. Storage at too low a temperature results in crystallization which starts at around 15 °C. The storage of the crystallized product must be avoided as this promotes the formation of non-meltable dimers. As a result, the product can no longer be fully melted after around three weeks. To prevent crystallization, it must be ensured that the product does not cool to below 20 °C.
Upon receipt, samples of the product should be tested for crystallization. If crystallization has occurred during transportation or storage, the product must be remelted immediately. On no account should the temperature during melting (material temperature) exceed 70 °C nor should the time needed to reliquefy the product be exceeded as this will greatly promote the formation of non-meltable dimers. It should be ensured that the entire content of the container is remelted and homogenized.
The container must then be closed immediately and its content cooled to and kept at the standard storage temperature (20 - 25 °C). If the product is in a partially crystallized state for a brief period, there will be no significant effect on the product quality. Only the storage stability may be reduced slightly, i.e. remelted product should be used as soon as possible.