abstract |
Comprising medium a) a buffer solution having a pH of 2.0 to 5.5, b) a water-soluble polymer in an amount of 1 to 50 percent by weight, c) a surfactant selected from the group of ionic or nonionic fluorosurfactants in an amount of 0.001 to 10% by weight and d) optionally one of a), b) or c) different polyhydroxy compound. |