- Jun 06, 2018-

General Properties and Applications:

Desmodur® 3133 is a mixture of modified diphenylmethane-4,4'-diisocyanate

(MDI) with isomers and homologues of higher functionality used for the production of the flexible polyurethane cold-curing HR molded foam for automotive seating.At room temperature the product is a blownish black liquid.


Moisture access must be prevented when taking product samples.




Unit of measurement 


NCO content

32.5 ± 0.5

% by wt.


Viscosity 25 °C

25 ± 10







Packaging: Drums


Recommended storage temperature (°C): 20~40 Shelf life (ex works)

4 months if stored in sealed, moisture-tight containers

Partially used containers should be tightly resealed due to the nature of the product.

Recommended temperature for processing (°C): 20 - 25

Labeling and REACH applications :

This product data sheet is only valid in conjunction with the latest edition of the

corresponding Safety Data Sheet. Any updating of safety-relevant information

– in accordance with statutory requirements – will only be reflected in the Safety 

Data Sheet, copies of which will be revised and distributed. Information relating to the current classification and labeling,

 applications and processing methods and further data relevant to safety can be found in the currently valid Safety Data Sheet.

Directions for Processing:

Prolonged exposure to excessively high temperatures may cause insoluble

precipitates to form. Temperatures below 15 °C, on the other hand, lead to

crystallization. If drums containing crystallized Desmodur® 3133 are carefully warmed to a maximum of 70 °C, however,

 the material will return to the liquid state, although this may lead to an increase in the solids content. Once the product has been reliquefied, 

the contents of the drums must be homogenized.

Desmodur® containers - including empty ones - should always be kept tightly sealed. It is absolutely essential that water (which reacts with Desmodur® 3133 to form polyureas, 

giving off carbon dioxide) be excluded from the containers.

During storage, transfer to other containers and processing of Desmodur® 3133 , therefore, 

the access of water in any form (damp containers, aqueous solvents, moist air) must be prevented, otherwise carbon dioxide will evolve and produce a dangerous increase in pressure in the tanks and containers. 

In addition to this, any polyureas forming in Desmodur®3133 will cause turbidity and possibility precipitation of solids, leading to blockages in the filters, pumps and pipelines of the foaming equipment.