| 摘要 |
The present invention related to a process for preparing aqueous polyester-polyacrylate dispersions having a cosolvent content of 0 to 5% by weight, based on the weight of the dispersion, by preparing a polymer P) in a first step by polymerizing A) a mixture of vinyl monomers that are capable of free-radical copolymerization, in the presence of B) one or more oligoesters prepared from compounds containing lactone groups and having a hydroxyl number of 145 to 710 mg KOH/g, an acid number of <=0.5 mg KOH/g solids and an average OH functionality of 2.5 to 5 mg KOH/g solids, and then mixing polymer P) in a second step with C) one or more polyester polyols having a hydroxyl number of 10 to 500 mg KOH/g solids and an acid number of >0.5 to <=30 mg KOH/g solids and dispersing the resulting polymer mixture in water in a further step, before or after addition of a neutralizing agent. The present invention also relates to the aqueous polyester-polyacrylate polymer dispersions obtained in accordance with the process of the invention and to aqueous coating compositions containing the aqueous polyester-polyacrylate polymer dispersions of the invention.
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