Abstract: The invention consists of an adhesive element (1) of the type comprising a plastic laminar support (2), an adhesive layer (3) applied to the support (2) and a protective layer (5) applied in a removable manner to the adhesive layer (3), the adhesive layer (3) being defined by a cold-polymerised polyurethane mixture between the support (2) and the protective layer (5). The process provides for formation of the adhesive layer (3) by applying a polyurethane mixture (9a) on the support (2) and subsequently cold-polymerising at ambient temperature the polyurethane mixture (9a) between the support (2) and the protective layer (5).