Applications
Desmodur® BL 3272 MPA was developed as a hardener for lightfast one-component stoving polyurethane coatings whose stoving temperature can be reduced by the addition of a catalyst, e.g. 0.3 - 1.0 % DBTL, without influencing the storage stability of the ready-to-use formulation. For example, Desmodur® BL 3272 MPA can be combined with Desmophen® T 1665 to formulate high-quality coil coatings with outstanding flexibility and good hardness and resistance to scratching and abrasion.Thanks to the chemical composition of the product, the formulations also have good weather stability comparable with that yielded by using, e.g. Desmodur® BL 3175 or BL 4265.Desmodur® BL 3272 MPA can be used to formulate both primers and top coats with a dry film thickness up to approx. 40 µm. The total film thickness of a two-coat system can thus be 70 µm.
Form supplied
Approx. 72 % in 1-methoxypropyl-acetate-2 (MPA)
Specification
Property | Test Condition | Value | Unit | Standard |
---|---|---|---|---|
Non-volatile content | (0.2 g/60 min/80 °C) | 72 ± 2 | % | M020-ISO 3251 |
Viscosity at 23 °C | 2,700 ± 750 | mPa*s | M014-ISO 3219/A.3 | |
Color value (Hazen) | ≤ 60 | M017-EN 1557 |
Typical Values
Property | Test Condition | Value | Unit | Standard |
---|---|---|---|---|
NCO content, blocked | approx. 10,2 | % | ||
Viscosity at 25 °C | approx. 2,300 | mPa*s | M014-ISO 3219/A.3 | |
Equivalent weight | approx. 410 | |||
Flash point | approx. 50 | °C | DIN 53 213/1 | |
Density at 20 °C | approx. 1,1 | g/ml | DIN EN ISO 2811 |
Solubility / thinnability
Desmodur BL 3272 MPA can be thinned to a solids content of 35 % by wt. with ketones, esters, ether esters, ether alcohols and aromatics, including mixtures of higher boiling aromatics such as solvent naphtha 100, 150 and 200. Aliphatic hydrocarbons cannot be used as thinners. The compatibility and storage stability of the thinned solutions must always be tested.
Compatibility
Given equivalent crosslinking, Desmodur BL 3272 MPA is generally mixable with Desmophen T 1665, 650, 651, 670, 680, 690, 800, 1100, 1200, 1300, 1652, RD 181, various polyacrylates as well as Alkydal® F 300 and F 310. The combinations should always be tested for their compatibility.
Storage
- Storage in original sealed Covestro container. - Recommended storage temperature: 0 - 30 °C. - Protect from moisture, heat and foreign material. General information: Storage at higher temperatures will result in increase of color and viscosity. Storage at significant lower temperatures will result in solidification. This solidification is reversible by briefly heating the product without adversely affecting the quality of the product.
Storage time
Covestro represents that, for a period of nine 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 nine 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 nine 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 nine months period.
Processing
Stoving cycle, e.g. in combination with Desmophen® T 1665 (NCO/OH = 1.0)
Under coil-coating conditions, adequate crosslinking is achieved by the addition of 0.3 % DBTL, calculated on the solid resin, from approx. 232 °C PMT (peak metal temperature).