Patent ID: 8657986

Claim:
A method for producing an active ingredient-containing polyurethane patch with a coating of a solvent-free, active ingredient-containing polyurethane composition on an elastic backing film, comprising the steps of: producing a dual web comprising said elastic backing film and at least one monoaxially inextensible auxiliary film, said at least monoaxially inextensible auxiliary film underlying and adhering to said elastic backing film thereby rendering said elastic backing film inextensible in at least a processing direction; feeding the dual web to a coating unit in the processing direction; reactive coating onto the elastic backing film of the dual web with the coating unit the solvent-free, active ingredient containing polyurethane composition, the solvent-free, active ingredient containing polyurethane composition being mixed before or with an application procedure of the coating unit, the reactive coating step producing a coated film on said dual web; and obtaining, from said dual web having said coated film, one or more individual patches containing at least a layer of said coated film and a layer of said elastic backing film.