A security element for securing value documents comprises a first polymer containing a feature substance, which is at least partially surrounded by a second polymer, wherein the first polymer is a hydrophobic, water-insoluble polymer which, at an elevated pH value and at elevated ambient temperature at a treatment duration of less than 60 minutes can be converted into a hydrophilic, water-soluble polymer. The security elements also contains a second polymer, which is a hydrophilic, water-soluble polymer, wherein the elevated pH value is greater than 12 and the elevated ambient temperature is greater than 90° C.