Coating material

A coating material comprising:

• a) a carrier layer having a base material;
• b) at least one biocide layer containing a biocidic agent applied to the carrier layer;
• and
• c) a transport control layer applied to a biocide layer with a gas permeability for oxygen (O2) of between 50 and less than 100 (cm3 bar)/(day m2);
• wherein the biocidic agent is an inorganic biocidic agent comprising a first substance selected from the group consisting of silver, copper, zinc, their ions, their metal complexes, and a mixture comprising at least two of the first substances;
• wherein the transport control layer and the carrier layer each has a base material;
• wherein the base material of the transport control layer has the same composition as the base material of the carrier layer;
• wherein the biocidic agent has a mean particle size of 5-100 nm;
• wherein the biocide layer comprises a second substance selected from the group consisting of gold, platinum, palladium, iridium, tin, antimony, their ions, their metal complexes, and an alloy formed from the biocidic agent and one or more of the second substances;
• wherein the base material of each of the transport control layer and the carrier layer is selected from the group consisting of
• a) an organic base material, and
• b) an inorganic base material and a non-biocidic metal;
• wherein the transport control layer has a silicon content of between 20-60%, a carbon content of between 10-30% and an oxygen content of between 30-50%;
• wherein the biocide layer has an average thickness of between 5-100 nm;
• wherein the transport control layer has an average thickness of between 5-500 nm;
• wherein the carrier layer has a silicon content of 20-60%, a carbon content of 10-30% and an oxygen content of 30-50%;
• and
• wherein the coating material comprises a plurality of carrier layers and biocide layers, so that at least one biocide layer is embedded between two carrier layers.