• Coatings

Desmodur® BL 4265 SN

Blocked, aliphatic polyisocyanate based on IPDI. In combination with polyol components to formulate lightfast one-component stoving coatings.

Contact an Expert
Market Switch
Selection will influence the results you get.
Copied to clipboard


Product Types

  • PIC
  • Crosslinkers
  • Hardeners
  • Aliphatic polyisocyanate
  • Isocyanate
  • Polyisocyanurate
  • Polyisocyanate


Hard, Thermally resistant, Solventborne

General Characterization

Desmodur BL 4265 SN is a blocked, aliphatic polyisocyanate based on isophorone diisocyanate (IPDI).
It is suitable for use in combination with polyol components to formulate lightfast one-component stoving coatings.

Storage Conditions

Desmodur BL 4265 SN should be stored in tightly sealed original containers and protected from moisture, heat, and foreign materials. Recommended storage temperature is 0º-30ºC.
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.


No data available

Packaging Type

No data available

Technical Properties & Datasheets


Property Name Test Method Unit Value
Non-volatile content (0.2 g / 60 min / 125^oC) % 65 ± 2
Free NCO content (modified) % < 0.2
Hazen color value ≤ 100
Viscosity at 23^oC mPa∙s 11,000 ± 3,000


Property Name Test Method Unit Value
Density at 20°C g/ml approx. 1.03
Flash point °C approx. 47
Viscosity at 25° mPa∙s approx. 10,500
Blocked NCO content % approx. 8.1
Equivalent weight approx. 520


Technical Data Sheet
Safety Data Sheet
No direct download available, please visit www.productsafetyfirst.covestro.com

Do you want to know more about Desmodur® BL 4265 SN?
Get in touch with our experts!

Contact form image Zoe

How can we contact you?

* Mandatory Fields