TAPES AND METHODS OF USE FOR MASKING ALUMINUM SURFACES IN ACID ANODIZATION

A tape includes: a flexible backing layer having two major surfaces, wherein the backing layer has a thickness of greater than 25 micrometers; and an acrylic-based pressure sensitive adhesive layer disposed on one major surface of the backing layer, wherein the acrylic-based pressure sensitive adhesive comprises the reaction of one or more (C8-C20)alkyl acrylates with one or more reinforcing monomers having a homopolymer Tg of at least 50° C., wherein the acrylic-based pressure sensitive adhesive has a tan δ of at least 0.5 measured at 80° C. and an oscillating frequency of 1 radian/second, and wherein the acrylic-based pressure sensitive adhesive layer has a thickness of at least 5 micrometers; wherein, when disposed on an aluminum substrate, the tape displays clean removal from the aluminum substrate according to the Clean Removal Test described in the Examples Section, and a leakage distance of less than 762 micrometers according to the Chromic Acid Anodization-Leakage Distance Test described in the Examples Section. A method of anodizing an aluminum surface includes: providing a substrate having an aluminum surface; applying a tape as described herein to mask the aluminum surface and form a masked substrate; and exposing the masked substrate to an electrolyte solution including chromic acid under conditions effective to form aluminum oxide.