| 摘要 |
The invention relates to aqueous polyester-polyacrylate dispersions based on copolymers, to a process for their preparation, and to aqueous coating compositions based thereon and the use thereof as lacquers. The dispersions are prepared from a polyester component A) that comprises the reaction product of A1) one or more saturated, aliphatic and/or aromatic di-, tri- or tetra-carboxylic acids or their anhydrides, and A2)one ore more diols and/or polyols, and a polyacrylate component B) that comprises the reaction product of B1) one or more OH-group-free (meth)acrylic acid esters and/or vinyl aromatic compounds, B2) one or more hydroxy-functional vinyl monomers or hydroxy-functional (meth)acrylic acid esters, and B3) one or more acid-group-containing monomers capable of free-radical copolymerisation, herein te polyester component A) has a hydroxyl number of from 180 to 300 mg KOH/g substance and an acid number of from 0.5 to 30 mg KOH/g, and the polyacrylate component B) has a hydroxyl number of from 10 to 180 mg KOH/g and an acid number of from 10 to 100 mg KOH/g, and the copolymer has an OH number smaller than that of the polyester component A) and greater than 27 mg KOH/g.
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