Wood or wood product coated with an aqueous, air-drying coating agent

A coated wood or wood product article which comprises a wood or wood product substrate coated with an aqueous, air-drying coating agent containing a water-soluble, air-drying binder wherein the binder is a polyacrylate having a molecular weight of more than 1,000 and having 5 to 40 weight per cent of chemically incorporated drying fatty acids, calculated as R--COO-- where R is the hydrocarbon portion of the drying fatty acid, and 50 to 200 milliequivalents per 100 grams of solid of chemically incorporated quaternary ammonium moieties which coating agent has been prepared by a process which comprises reacting

• A) excess polyacrylate containing epoxide groups and having an epoxide group equivalent weight of 200 to 1,300 with
• B) drying fatty acids, in an addition reaction with ester formation,
• C) reacting at least some of the remaining epoxide groups in the A)-B) reaction product with monoamine ammonium salts which contain one N--H bond in an addition reaction, and
• D) dissolving the reaction product obtained from step C) and containing quaternary ammonium groups in water.