| 摘要 |
<p>The invention relates to an air-drying aqueous polymer dispersion based on a core/shell polymer having an alkyd resin in the core and an addition polymer grafted thereon, with 50-90 wt.% of the core/shell polymer being comprised of alkyd resin and 50-10 wt.% being comprised of addition polymer, and with the alkyd resin containing more than 40 and up to 80 wt.% of unsaturated fatty acid, at least 5 mole% of which contains conjugated double bonds, having an acid number of not more than 5 (mg KOH/g), and having a number average molecular weight in the range of 400 to 5000, and with the addition polymer having an acid number in the range of 40 to 200 (mg KOH/g). The aqueous polymer dispersions according to the invention were found to be highly stable and to have a comparatively low viscosity, even at concentrations of 40 wt.% and above. It was found that topcoats obtained using dispersions with a high alkyd resin content are virtually identical in terms of properties with topcoats obtained in a traditional manner using alkyd paints based on organic solvents, while the gloss of topcoats obtained using the polymer dispersions according to the invention frequently is even higher.</p> |
