Use for substrates devoid of formaldehyde aqueous binder.

Using free aqueous binders of formaldehyde, with a wide molecular weight distribution, containing polymers composed of monomers A) and B), with (A) 5 to 50% by weight of an acid anhydride ethylenically unsaturated or a dicarboxylic acid ethylenically unsaturated whose carboxylic acid groups can form an anhydride group, mixtures thereof [monomers a)], (B) 50-95% by weight of an ethylenically unsaturated compound [monomers B)] different from a and (C) at least one polyfunctional crosslinker or mixtures thereof, and polymers obtained by radical polymerization of a) and B), to be classified in a coordinate system for its average Mw and polydispersity values ​​molecular weight are in the area by above a line defined by the equation y = 1.25x straight + 20000 and displaced in parallel direction and at least + 3000, and the x axis is called average molecular weight and the y axis It is called polydispersity multiplied by 10000.