The invention relates to a block copolymer which is produced by a controlled radical polymerization, has an individual composition and structure and is used for adhesion in a humid medium The inventive copolymer comprises a continuous flexible and water repellent matrix (of elastomer nature) and a dispersed phase in the form of hydrophilic nanodomains. Said copolymer exhibits an excellent adhesion as a result of the structure thereof also in a very humid medium.