Bayhydrol D 155-BOE/iB/W Saturated polyester resin Bayer MaterialScience Polyester >> Saturated Coatings >> Waterborne 2-butoxyethanol/isobutanol/water and neutralised with dimethyl ethanol amine 16.5:6.8:18:3.7 Soluble in water, glycol ethers and alcohols Water-thinnable, oil-free, saturated polyester with good resistance to hydrolysis As a binder in the formulation of stoving top coats and primers. Bayhydrol D 155 is an oil-free polyester with extremely good resistance to hydrolysis which is already neutralised with dimethyl ethanol amine. It is thinned with water for application. Combined with hexamethoxymethyl melamine resins (HMMM) and partially methyletherified melamine resins, Bayhydrol D 155 can be used to formulate water-thinnable stoving top coats and primers. Combination with HMMM resins yields highly flexible primers and top coats. Bayhydrol D 155 has proved particularly suitable for dip primers applied beneath powder coatings. If Bayhydrol D 155 is combined with partially methyl-etherified amino resins, stoving systems can be formulated which cure in 30 minutes at 120 °C. As a rule, the ratio of Bayhydrol D 155/amino resin is between 85:15 and 75:25, calculated on the solid resin. Given the many different amino resins on the market, compatibility should always be tested. Coatings based on Bayhydrol D 155 will remain stable at room temperature for at least 6 months. It should be ensured that the pH is adjusted to 8.5 to 9 after formulation. Depending on the reactivity of the amino resin and the pigment/extender combination used, the viscosity of the coatings and primers may increase slightly after prolonged storage at room temperature. This increase may be minimised by checking the pH and adjusting it as necessary to 8.5 to 9. Formulation Bayhydrol D 155 is characterised by its good pigment wetting properties and high shear stability. Bead and sand mills have proved suitable for grinding. The pigments and extenders are ground in some of the Bayhydrol D 155 and deionised water to ensure the necessary dispersion viscosity. Because of the excellent shear stability, dispersion temperatures of up to 50 °C have no detrimental effect. The pigments and extenders used should have the lowest possible water-soluble content. Given the many different pigments and extenders available, the storage stability should always be tested. Water-thinnable, oil-free, saturated polyester resin. Used as a binder in the formulation of stoving top coats and primers. Provides very good resistance to hydrolysis. Can be combined with hexamethoxymethyl melamine resins (HMMM) and partially methyletherified melamine resins to formulate water-thinnable stoving top coats and primers. Offers good pigment wetting properties and high shear stability.