Use of an aqueous polymer dispersion as a binding agent for cellulose fibers and for the production of filter materials

A process for impregnating or coating base paper or filter material comprising resinating by impregnating the paper or the filter material with an aqueous polymer dispersion obtainable by free-radical emulsion polymerization, wherein the polymer of said aqueous polymer dispersion is comprised of monomer units as follows:

• a) 0.1-5% by weight of methacrylic acid,
• c) 0.1-4% by weight of N-methylolacrylamide,
• d) 30-98.8% by weight of principal monomers M, and
• e) 0-20% by weight of monomers other than a, c-d
• wherein said polymer comprise 1-10% by weight of methyl methacrylate
• wherein the principal monomers M are selected from the group consisting of C1-C20 alkyl (meth)acrylates, vinyl esters of carboxylic acids comprising up to 20 carbon atoms, vinylaromatics having up to 20 carbon atoms, ethylenically un-saturated nitrites, vinyl halides, vinyl ethers of alcohols comprising 1 to 10 carbon atoms, aliphatic hydrocarbons having 2 to 8 carbon atoms and 1 or 2 double bonds, and mixtures thereof.