Bayhydrol D 270 Saturated polyester resin Bayer MaterialScience Polyester >> Saturated Coatings >> Waterborne Automotive OEM >> Primer / Surfacer Automotive OEM >> Top coats General Industrial /Maintenance water/butyl diglycol and neutralised with dimethyl ethanol amine 11.5:13.3:5.2 Soluble in water, glycol ethers, glycols and alcohols Water-thinnable, oil-free, saturated polyester In combination with water-thinnable amino resins in the formulation of industrial stoving coatings and aqueous stoving primer surfacers for on-line automotive finishing, both with a low co-solvent content. Combined with water-thinnable amino resins, Bayhydrol D 270 is particularly suitable for the formulation of aqueous stoving primer surfacers with low co-solvent content for use in on-line automotive finishing. To ensure good intercoat adhesion to conventional automotive topcoats, a Bayhydrol/amino resin ratio of 90 : 10 to 85 : 15 (calculated on the solvent-free resin) is recommended. The paint films yielded have good hardness, flexibility and adhesion. If above-average stone-chip resistance is required, Bayhydrol D 270 should be combined with Bayhydrol polyurethane dispersions. Bayhydrol D 270 can also be used in general industrial finishing. Depending on the reactivity of the melamine resin used, a ratio of 85 : 15 to 70 : 30 can be used to formulate highly flexible primers and hard, well-crosslinked, high-gloss top coats. Bayhydrol D 270 has proved particularly suitable for the formulation of dip primers which are subsequently overcoated with powder coatings. The stoving conditions for Bayhydrol D 270 depend on the type of amino resin used. The stoving range is between 30 min at 120 °C and 60 min at 180 °C in the overbaking process. Because of the good shear stability of Bayhydrol D 270, the pigments can be added directly to the binder. Suitable grinding equipment includes the bead mill, dyno mill and red devil. However, the use of suitable wetting agents and antifoams is essential. Optimum pigment wetting is achieved if the entire amount of dimethyl ethanol amine required to adjust the coating to a pH of 8.5 - 8.8 is added to the mill base. Details are given in the guide formulations for Bayhydrol D 270. Water-thinnable, oil-free, saturated polyester resin. Used in combination with water-thinnable amino resins in the formulation of industrial stoving coatings and aqueous stoving primer surfacers for on-line automotive finishing, both with a low co-solvent content. Offers good hardness, flexibility and adhesion.