Before working with this product, you must read and become familiar with the available information on its risks, proper use, and handling. Information is available in several forms, e.g., in particular in the currently valid safety data sheets and product labels. For further information contact your Covestro representative.
Product description
Desmodur® E 23500 is a diphenylmethane diisocyanate (MDI)-terminated polyether prepolymer based on polypropylene ether glycol (PPG).
Applications
Desmodur E 23500 is a very low isocyanate prepolymer and may be blended with suitable diluents to formulate one-component moisture cured sealants and ultrasoft elastomers. Typical applications include flexible caulks and sealants. As with any product, use of Desmodur E 23500 in a given application must be tested (including but not limited to field testing) in advance by the user to determine suitability.
Form supplied
Yellow, viscous liquid
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| NCO content | 3,5 | Wt. % | ||
| Viscosity (25°C) | approx. 12000 | mPa*s |
Storage
Desmodur E 23500 prepolymer must be stored in tightly closed containers and protected from contamination with moisture and foreign materials, which can adversely affect processing. It will slowly react with water to form ureas and carbon dioxide gas, which may cause sealed containers to expand and rupture. The headspace of partially filled containers should be blanketed with dry nitrogen. Storage temperatures should be maintained between 18° to 30°C (64.4° to 86° F). Within this range, a storage temperature of 25°C (77°F) will maximize the storage life of the product. Desmodur E 23500 prepolymer must not be allowed to freeze. Exposure to temperatures less than 15°C (60°F), even for short periods of time, can result in the formation of solid material. During the winter months, appropriate precautions must be taken during shipment and storage. Prolonged storage of solid or partially solid Desmodur E 23500 prepolymer may result in the formation of MDI dimer in amounts that exceed its solubility in the prepolymer at normal storage temperatures. This can make the product unusable. If solids should form because of exposure of Desmodur E 23500 prepolymer to low temperatures, it may be possible to reliquify the product by reheating. Use a well ventilated oven for the minimum time necessary to render it clear. The temperature of the product should not exceed 60°C (140°F) Agitation or drum rollers are recommended to avoid excessive local heating, which will degrade the product. Significant amounts of MDI dimer may form during the heating process. As a result, the remelted prepolymer may be cloudy and the processing behavior and/or properties of the final product may be affected.
Storage time
Desmodur E 23500 has a shelf life of six months from the date of receipt at customer, provided the material is stored in sealed original containers at the recommended storage temperature.
Health and Safety Information
Disclaimer
General
The manner in which you use our products, technical assistance and information (whether verbal, written or by way of production evaluations), including any suggested formulations and recommendations, are beyond our control. Therefore, it is imperative that you test our products to determine suitability for your processing and intended uses. Your analysis must at least include testing to determine suitability from a technical, health, safety, and environmental and regulatory standpoint. Such testing has not necessarily been done by Covestro, and Covestro has not obtained any approvals or licenses for a particular use or application of the product.
Unless we otherwise agree in writing, all products are sold strictly pursuant to the terms of our standard conditions of sale which are available upon request.
All information and including technical assistance is given without warranty or guarantee and is subject to change without notice. It is expressly understood and agreed by you that you assume and hereby expressly release indemnify us and hold us harmless from all liability, in tort, contract or otherwise, incurred in connection with the use of our products, technical assistance, and information. Any statement or recommendation not contained herein is unauthorized and shall not bind us. Nothing herein shall be construed as a recommendation to use any product in conflict with any claim of any patent relative to any material or its use. No license is implied or in fact granted under the claims of any patent.
Non Medical and non Food Contact
This product is not designated for the manufacture of a medical device or of intermediate products for medical devices (1). This product is also not designated for other specifically regulated applications (e.g. including cosmetics, plant protection, fertilisers, plant strengtheners, food processing, food contact and others). If the intended use of the product is for the manufacture of a medical device or of intermediate products for medical devices or for other specifically regulated applications Covestro must be contacted in advance to provide its agreement to sell such product for such purpose. Nonetheless, any determination as to whether a product is appropriate for use in a medical device or intermediate products for medical devices, for Food Contact products or cosmetic applications must be made solely by the purchaser of the product without relying upon any representations by Covestro.
1) Please see the Guidance on Use of Covestro Products in a Medical Application document.
Sample
Any samples provided by Covestro are for testing purposes only and not for commercial use.
Typical value
These values are typical values only. Unless explicitly agreed in written form, they do not constitute a binding material specification or warranted values
Contact
Please use our contact form or contact us directly by sending an e-mail to technical-datasheets@cx.covestro.com .
