The invention relates to a polymer dispersion which contains water, at
least one polymer that has been produced by emulsion polymerisation, at
least one protective colloid, at least one water-soluble acidic metallic
salt and at least one cross-linking resin that is based on
phenol-formaldehyde condensation products, hydroxymethyl-substituted
imidazolidinones, such as 1,3-dimethylol-4,5-dihydroxy-imidazolidinone
(4,5-dihydroxy-N,N'-dimethylolethylene urea), hydroxymethyl-substituted
pyrimidinones, or hydroxymethyl-substituted triazinones or their
auto-condensation products, or mixed condensates from two or more of the
aforementioned compounds, or a mixture of two or more of the
aforementioned compounds.