A strip tape has a structure, in order, comprising the following layers: a first layer with an outwardly facing surface of polypropylene; a first adhesive layer; a core layer of an oxygen barrier polymer; a second adhesive layer; and a second layer with an outwardly facing surface of polypropylene. In addition, a packaging container is provided with the strip tape to protect a longitudinal joint of the container, on the inside thereof. A method of producing the strip tape involves joining a first film having an outwardly facing surface of polypropylene to a first side of a core layer film having an oxygen barrier polymer by adhesive lamination with a first adhesive layer and joining a second film having an outwardly facing surface of polypropylene to a second side of the core layer film by adhesive lamination with a second adhesive layer.