Covestro certifies that the product meets specifications for 6 months from the date of shipment, provided it is stored and handled in accordance with the conditions specified in the ‘Storage’ section. After this period, product performance is not assured; Customers are responsible for retesting material before use. Covestro assumes no liability for product performance after 6 months.
Product description
Aromatic polyisocyanate prepolymer based on diphenylmethane diisocyanate (MDI).
(A)
As a binder for the formulation of moisture-curing, one-component coatings and adhesives.
(B)
As a hardener for hydroxyl-bearing co-reactants.
Applications
Desmodur® E 21 is suitable for use in the formulation of moisture-curing one-component systems which, when thinned with a suitable solvent, can be used as a primers and sealers for porous substrates to provide protection against moisture, oil, fuel and other chemicals.
It can also be used as a binder in the formulation of synthetic resin mortars.
In combination with suitable Desmophen polyols, Desmodur® E 21 yields tough but flexible, wear-resistant coatings and sealers.
Desmodur® E 21 is also suitable for use in the formulation of moisture-curing one-component adhesives or in combination with Baycoll® to formulate two-component adhesives. These can be used to bond many materials, e.g. wood, metal and plastic.
Form supplied
Brown liquid of medium viscosity.
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Dynamic viscosity | 25 °C | 4,100 - 6,700 | mPa·s | MDI-01-02 |
| NCO content | 15.3 - 16.7 | % | MDI-01-01 |
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Flash point | > 250 | °C | DIN EN 22719 | |
| Density | 20 °C | 1.15 | g/cm³ | DIN 53217 |
Solubility / thinnability
In general, Desmodur® E 21 has good compatibility with ethyl acetate, butyl acetate, 1-methoxypropylacetate-2, xylene, Shellsol® A and Solvesso® 100. However, the solutions formed must be tested for their storage stability. Prolonged storage of a solution with low binder content may result in turbidity and sedimentation. Only PU grade solvents should be used (< 0.05 % water). The solvent should not contain reactive groups.
Compatibility
In general, Desmodur® E 21 is compatible with Desmophen®/Baycoll® polyols, with other Desmodur® products and with flexibilizers.
Storage
- Storage in original sealed Covestro container.
- Recommended storage temperature: room temperature (approx. 23 °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. Storage at high temperatures will lead to an increase in viscosity and a reduction of the NCO content.
Storage time
Health and Safety Information
Before working with this product, you must read and become familiar with the available information regarding its risks, proper use, and safe handling. This information is provided in various formats, including the current Safety Data Sheet (SDS) and product label. SDS can be accessed via the following link:
Safety Data Sheets (SDS) for Covestro products | Covestro
For further questions, please use the contact information provided on this technical data sheet.
Disclaimer
Responsibility and Liability
The use of Covestro products, technical assistance, and information (regardless of how provided) is outside Covestro’s control and is solely the responsibility of the customer. The customer must conduct adequate testing to determine the suitability of products for its intended use, including but not limited to technical, health, safety, and environmental aspects. Unless otherwise agreed in writing, all products are sold exclusively under Covestro’s standard conditions of sale, which prevail in case of conflict and are available upon request.
The terms and conditions of sale and delivery are available via the following link:
https://order.covestro.com/covestrostorefront/saleConditions
All information is provided “as is” without warranties, express or implied, including merchantability or fitness for a particular purpose, and is subject to change without notice. To the maximum extent permitted by law, Covestro disclaims, and the customer assumes all liability for losses, damages, or claims arising out of use of Covestro products, technical assistance, or information. Any statement or recommendation not expressly contained in Covestro documentation is unauthorized and shall not bind Covestro. Nothing herein shall be construed as encouraging or recommending the use of any product in conflict with any claim of any patent. No license is implied or in fact granted under the claims of any patent.
Restrictions on Regulated Applications
This product is not intended for use in regulated applications such as agriculture, cosmetics, drinking water contact, food contact, medical products (e.g., medical devices), toys, or similar uses subject to specific regulatory requirements. Prior written approval from Covestro is required before this product may be used in any regulated application. The customer is solely responsible for ensuring compliance with all applicable laws and determining product suitability. Covestro disclaims all liability and warranties for unauthorized regulated uses.
Typical Value
The values provided are typical only and do not represent binding specifications. Unless expressly confirmed in a written contract, these values are not part of the contractual quality agreement and must not be relied upon as a warranty or guarantee of product performance.
Sample
Samples provided by Covestro are intended solely for evaluation and testing purposes by the customer and may not be used in commercial applications, resold, transferred to third parties (except qualified testing service providers acting on behalf of the customer), reverse engineered, modified, or used in any manner not explicitly authorized in writing by Covestro. Samples are provided ‘as-is’ without any warranties, express or implied, including fitness for a particular purpose. Customers are solely responsible for ensuring safe handling, regulatory compliance, and suitability of the material for their intended evaluations. Covestro disclaims all liability for damages or losses arising from the use of samples.
Contact Information
Please use our contact form or contact us directly by sending an e-mail to technical-datasheets@cx.covestro.com .
