Desmodur-MDI based curing agent

Covestro Desmodur E21 MDI prepolymer for moisture-curing one-component coatings and adhesives

type	Aromatic polyisocyanate prepolymers based on diphenylmethane diisocyanate (MDI)
form of supply	Solvent-free medium viscosity liquid
use	A. As a binder for the preparation of moisture-curing one-component coatings and adhesives B. Curing agent as hydroxyl co-reactant

Product Specifications

characteristic

Numerical value

Units of measurement

method

NCO content

16.0±0.7

Internal testing method

2011-0248603-94

Viscosity, 25°C

5400±1300

mPa·s

Internal testing method

2011-0313703-95

other data*

characteristic	Numerical value	Units of measurement	method
equivalent	251-274
Flash point	>250	°C	DIN EN ISO 2719
Density@20℃	约1.15	g/ml	DIN EN ISO 2811-1

*The above values are general information and are not part of product specifications.

Solubility / Dilution
In general, Desmodur® E 21 is compatible with ethyl acetate, butyl acetate, propylene glycol methyl ether acetate, xylene, Shellsol® A and Solvesso® 100.
However, the storage stability of the diluted solution still needs to be tested. Long-term storage of low solids solutions may cause turbidity and precipitation. Polyurethane grade solvents should be used (less than 0.05% water content), which must not contain reactive groups.

compatibility
Generally, Desmodur® E 21 is compatible with Desmophen®/Baycoll® polyols and other Desmodur® products and tougheners.

Features/Applications
Desmodur® E 21 is suitable for the preparation of moisture-curing one-component coatings and can be used as a primer and sealer for porous substrates when diluted with suitable thinners, protecting substrates from moisture, oils, fuels and other chemicals .
This product can also be used as a resin for the preparation of synthetic resin mortar. When mixed with the appropriate Desmophen® polyols, this product produces tough, hardwearing coatings and sealers. Desmodur® E 21 is also suitable for the preparation of solvent-free moisture-curing one-component adhesives, or mixed with Baycoll® to prepare two-component adhesives. These two adhesives can be used to bond a variety of materials such as wood, metal and plastic.

store .
This product is sensitive to moisture and should be stored in the original airtight container. High temperature storage results in increased viscosity and reduced NCO content.
The shelf life of this product is at least 6 months when stored under proper conditions.

Safety: Hazard Identification
Harmful by inhalation, irritating to eyes, respiratory system and skin. Inhalation and skin contact can cause allergic reactions.
Product Safety Data Sheets (MSDS) should be strictly followed. This Safety Data Sheet includes information on labelling, transportation and storage, as well as information on product use, product safety and ecology.