Composition consisting of the components: (a) 1 to 30 wt% of a 1 to 90 wt.% aqueous phosphoric acid and/or at least one hydrogen phosphate selected from the group consisting of mono- and dihydrogen phosphates of sodium, potassium, ammonium, magnesium, calcium, aluminum, zinc, iron, cobalt and copper, (b) 1 to 40 wt.% of at least one compound selected from the group consisting of oxides, hydroxides and oxide hydrates of magnesium, calcium, iron, zinc and copper, (c) 40 to 95 wt.% of at least one particulate filler selected from the group consisting of: glass; mono-, oligo- and polyphosphates of magnesium, calcium, barium and aluminum; calcium sulfate; barium sulfate; simple and complex silicates comprising sodium, potassium, calcium, aluminum, magnesium, iron and/or zirconium; simple and complex aluminates comprising sodium, potassium, calcium, magnesium and/or zirconium; simple and complex titanates comprising sodium, potassium, calcium, aluminum, magnesium, barium and/or zirconium; simple and complex zirconates comprising sodium, potassium, calcium, aluminum and/or magnesium; zirconium dioxide; titanium dioxide; aluminum oxide; silicon dioxide; silicon carbide; aluminum nitride; boron nitride; and silicon dioxide, wherein the complex silicates, aluminates, titanates and zirconates are not complex compounds but rather silicates, aluminates, titanates and zirconates having more than one type of cation, (d) 1 to 10 wt.% of at least one urea compound selected from the group consisting of imidazolidin-2-one, allantoin and imidazolidinyl urea, and (e) 0 to 15 wt.% of at least one component different from the components (a) to (d), wherein the wt.% fractions of the components (a) to (e) add up to 100 wt.%. (a) 1 to 30 wt% of a 1 to 90 wt.% aqueous phosphoric acid and/or at least one hydrogen phosphate selected from the group consisting of mono- and dihydrogen phosphates of sodium, potassium, ammonium, magnesium, calcium, aluminum, zinc, iron, cobalt and copper, (b) 1 to 40 wt.% of at least one compound selected from the group consisting of oxides, hydroxides and oxide hydrates of magnesium, calcium, iron, zinc and copper, (c) 40 to 95 wt.% of at least one particulate filler selected from the group consisting of: glass; mono-, oligo- and polyphosphates of magnesium, calcium, barium and aluminum; calcium sulfate; barium sulfate; simple and complex silicates comprising sodium, potassium, calcium, aluminum, magnesium, iron and/or zirconium; simple and complex aluminates comprising sodium, potassium, calcium, magnesium and/or zirconium; simple and complex titanates comprising sodium, potassium, calcium, aluminum, magnesium, barium and/or zirconium; simple and complex zirconates comprising sodium, potassium, calcium, aluminum and/or magnesium; zirconium dioxide; titanium dioxide; aluminum oxide; silicon dioxide; silicon carbide; aluminum nitride; boron nitride; and silicon dioxide, wherein the complex silicates, aluminates, titanates and zirconates are not complex compounds but rather silicates, aluminates, titanates and zirconates having more than one type of cation, (d) 1 to 10 wt.% of at least one urea compound selected from the group consisting of imidazolidin-2-one, allantoin and imidazolidinyl urea, and (e) 0 to 15 wt.% of at least one component different from the components (a) to (d),