Butyl is a synthetic rubber used in many applications including as an adhesive product. When used on a tape it's used to join two butting or overlapping surfaces and left to set. Once dry it remains elastic and is water-resistant. Butyl tape is used in car windshields, roofing, boats, on PVC piping and to many other purposes. The only drawback is that it doesn't remove cleanly, often leaving behind dried or slightly elastic pieces of adhesive.
Scrap up the surface tape with a putty knife. Pull the tape up slowly and get as much adhesive as you can while removing.2
Cover the remaining adhesive with adhesive remover or paint thinner, such as Toulene. Allow the product to sit for several minutes.3
Scrape up the softened adhesive with the putty knife. Repeat step two as needed.4
Clean the adhesive free surface with a water soaked cloth. Allow to dry.