Paint & Coatings

Desmophen® T 1775 SN

Covestro (formerly Bayer MaterialScience) 科思创

Desmophen T 1775 SN is an oil free, hydroxyl-bearing polyester that is used in the formulation of lightfast one-component polyurethane baking coatings with blocked aliphatic polyisocyanates. It is binder certified for use in food-contact applications for the formulation of can coatings for food packaging. This product has a non-volatile content (2g resin/2ml toluene/1h 125°C/convection oven) of 75 ± 2%, a density at 20°C of approx. 1.08g/ml, and a viscosity at 23°C of 3,700 ± 600 mPa·s. Desmophen T 1775 SN was developed specially as a co-reactant for blocked polyisocyanates in coil coating applications. When combined with preferably Desmodur BL 4265, it yields one-component polyurethane coil coatings with a balanced hardness/flexibility ratio, good resistance to scratching and abrasion as well as excellent QUV/B stability. Dibutyltin dilaurate has proved suitable as the catalyst. The addition should be 0.1–1 %, calculated on the solid binder. The product can be combined with other blocked isocyanates and HMMM-type amino resins. However, such formulations do not generally achieve the same high surface hardness as is achieved with Desmodur BL 4265.