Aqueous binder composition

An aqueous binder composition comprising as essential binder components

• a) at least one polymer P constructed from
• ≧0.1 and ≦10 wt % of at least one monoethylenically unsaturated compound having at least one silicon-containing group, an epoxy, hydroxyalkyl, N-methylol or carbonyl group, and/or of at least one compound which has at least two nonconjugated ethylenically unsaturated groups (monomers A)
• ≧0 and <5 wt % of at least one monoethylenically unsaturated C3 to C6 monocarboxylic and/or C4-C6-dicarboxylic acid and also the salts and anhydrides thereof (monomers B), and
• >85 and ≦99.9 wt % of further ethylenically unsaturated compounds, different from the monomers A and B, the nature and amount of these ethylenically unsaturated compounds being selected such that a polymer constructed solely from them in polymerized form would have a glass transition temperature in the range ≧10 and ≦50° C. (monomers C),
• in polymerized form, wherein the amounts of monomers A to C sum to 100 wt %, and
• b) at least one lignin compound L, the amount of which is determined such that it is ≧10 and ≦60 parts by weight per 100 parts by weight of polymer P.