| Water-reducible, hydroxyfunctional polyacrylic dispersion. In combination with aliphatic polyisocyanates to formulate aqueous two-component clear- and topcoats for vehicle repair applications, heavy transport finishing and industrial coating. In combination with amino resins or blocked polyisocyanates for waterborne, one-component, industrial baking coatings. Properties / Applications:
General: Bayhydrol® A 145 is a hydroxyfunctional polyacrylic dispersion which can be thinned with water to application viscosity. Bayhydrol® A 145 has good pigment wetting properties and high shear stability. Bead mills have proved suitable as grinding equipment. Only pigments and extenders with a minimal water-soluble content should be used. Given the many pigments and extenders available, compatibility testing should always be carried out. Leveling and substrate wetting can be optimized by adding Byk® 380 or Byk® 348, for example. Byk® 011 has proved to be a suitable antifoam. Application and formulation equipment can be cleaned with water, alkaline cleaning agents or isopropanol.
Two-component industrial coatings: Bayhydrol® A 145 combined with aliphatic polyisocyanates yields high-gloss topcoats which can be dried at room temperature or force-dried, e.g. at 80 °C. The cured paint films are hard and flexible with good single-coat adhesion and good resistance to solvents and water. When properly formulated, e.g. in combination with Bayhydur® 3100 in an NCO/OH ratio of 1.5 : 1, the pot life is approximately 3 hours. The formulated coating should have a pH between 7.8 and 8.3. When mixing Bayhydur® or Desmodur® into the mill base, a thickener must be added to ensure a high shear effect. The addition of approx. 0.3 % Acrysol® RM 8 (calculated on the solid binder) has proved suitable for formulations based on Bayhydrol® A 145. Information provided by Covestro |
