Polyisocyanate prepolymer based on diphenylmethane diisocyanate.As a stabilizer for pigmented moisture-curing aromatic one-component polyurethane coatings.
Product description
Applications
Desmodur® MT reacts with water to release carbon dioxide. It serves as a dewatering agent to ensure the storage stability of moisture-curing pigmented one-component polyurethane coatings. The stoichiometric conversion of 1 g of water requires approx. 28 g of Desmodur® MT. Trials and experience have shown that the best results are obtained using two or three times this amount. The reactivity of Desmodur® MT with water is comparable with the reactivity of the Desmodur® E grades. The pigments, extenders and solvents should therefore be dewatered with Desmodur MT before addition to the main binder. This will prevent unwanted reactions and an in crease in viscosity. The Desmodur® MT content in the total binder of the ready-to-use coating should not exceed 30 %, calculated on the solvent-free resin.
Form supplied
brown solvent-free liquid of low viscosity
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| NCO content | 16,8 ± 0,5 | % | M105-ISO 11909 | |
| Viscosity | (23 °C) | 900 ± 300 | mPa*s | M014-ISO 3219/A.3 |
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Equivalent weight | approx. 250 | |||
| Flash point | approx. 217 | °C | EG A9 | |
| Density | at 20 °C | approx. 1,13 | g/ml | DIN EN ISO 2811 |
Solubility / thinnability
Generally speaking, Desmodur® MT has good solubility in esters such as ethyl acetate, butyl acetate and 1-methoxypropylacetate-2 and in aromatic hydrocarbons such as toluene, xylene, Solvesso® 100 and Shellsol® A. However, the solutions formed must be tested for their storage stability. The product is not compatible with white spirit.Alcohols react with Desmodur® MT and cannot therefore be used.Only PU grade solvents (< 0.05 % water) should be used. The solvents should not contain reactive groups.
Compatibility
Generally speaking, Desmodur® MT has good compatibility with other aromatic polyisocyanate prepolymers such as Desmodur® E 21, Desmodur® E 22 and Desmodur® E 1361.
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 time
Covestro represents that, for a period of six months following the day of shipment as stated in the respective transport documents, the product will meet the specifications or values set forth in section "specifications or characteristic data" above, what ever is applicable, provided that the product is stored in full compliance with the storage conditions set forth in and referenced under section "storage" above and is otherwise handled appropriately.The lapse of the six months period does not necessarily mean that the product no longer meets specifications or the set values. However, prior to using said product, Covestro recommends to test such a product if it still meets the specifications or the set values. Covestro does not make any representation regarding the product after the lapse of the six months period and Covestro shall not be responsible or liable in any way for the product failing to meet specifications or the set values after the lapse of the six months period.
Health and Safety Information
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.
Disclaimer
Contact
Please use our contact form or contact us directly by sending an e-mail to technical-datasheets@cx.covestro.com .
