THERMAL EXPANSION TYPE REMOVABLE ACRYLIC PRESSURE-SENSITIVE ANDHESIVE TAPE OR SHEET

摘要

The invention provides a thermal expansion type removable acrylic pressure-sensitive adhesive tape or sheet which exhibits high ordinary joint strength independent of whether the surface of an adherend is even or uneven and which permits easy disjoining or disjointing. The thermal expansion type removable acrylic pressure-sensitive adhesive tape or sheet is characterized by comprising a viscoelastic material containing both air bubbles and microparticles and a pressure-sensitive adhesive layer containing a thermal blowing agent which layer is formed on at least one side of the viscoelastic material. It is preferable that the acrylic pressure-sensitive adhesive tape or sheet contain air bubbles in an amount of 3 to 30vol% based on the whole volume of the viscoelastic material. Further, it is preferable that the viscoelastic material be a layer formed by polymerizing a polymerizable composition which comprises a vinyl monomer mixture comprising alkyl (meth)acrylates where the alkyl has 2 to 18 carbon atoms as the main component or a partial polymerizate thereof, a photopolymerization initiator, microparticles, a polyfunctional (meth)acrylate, and air bubbles.