Self-adhesive label containing biodegradable waterborne polyurethane pressure-sensitive adhesive

The self-adhesive label comprises a substrate material, a pressure-sensitive adhesive layer attached to the substrate material, and a release liner attached to the adhesive layer or a release coating layer on the other side of the substrate material. The substrate material is made of paper or a domestic compostable and biodegradable polymer film, and the pressure sensitive adhesive layer is made of an aqueous polyurethane dispersion pressure sensitive adhesive. At least 60% by weight of the polyurethane consists of a diisocyanate, a polyester diol and at least one difunctional carboxylic acid selected from the group consisting of dihydroxycarboxylic acids and diaminocarboxylic acids, the melting point of the polyurethane being not higher than 20 DEG C, or the melting point of the polyurethane being higher than 20 DEG C and the enthalpy of fusion being lower than 10 J/g, and wherein the film of polyurethane adhesive decomposes to CO2 and water in more than 90% by weight within 360 days under domestic compostin