Thermal expansion type removable acrylic pressure-sensitive andhesive tape or sheet

Abstract

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 30 vol% 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.

Description

technical field [0001] The present invention relates to a heat-foaming type re-peelable acrylic adhesive tape or adhesive that maintains a high normal adhesive force at the time of joining regardless of whether the adherend has a concave-convex surface or not, and that the adhesive force decreases by heating when peeled off. Composite. More specifically, it relates to maintaining high adhesive properties at the time of bonding regardless of whether the adherend has a concave-convex surface, and when disassembling for recycling or reprocessing after use, the adhesive force is reduced by heating, which can be easily bonded. Heat-foaming re-peelable acrylic adhesive tape or sheet that can be easily separated, and can maintain high adhesive properties at the time of joining, and can be easily separated by heating when peeling for reprocessing or recycling, etc. Heat-foaming re-peelable acrylic adhesive tape or sheet. Background technique [0002] Conventionally, base polymers ...

AI Technical Summary

Problems solved by technology

However, when the adhesive tape is peeled off in the reprocessing work caused by the poor adhesion of the adhesive tape during manufacture or the maintenance work when a defect is found in the inspection after the pasting, due to its strong adhesiveness, there is a problem that the adhesive tape cannot be peeled off. Problems that the tape is closed, or the member to which the adhesive tape is attached is damaged and cannot be reused even if it can be peeled off

[0008] In addition, as an acrylic foam-type pressure-sensitive adhesive tape, the acrylic foam-type pressure-sensitive adhesive tapes of Patent Documents 1 to 7 have been known so far, but it is difficult for these pressure-sensitive adhesive tapes to simultaneously achieve excellent Normal Adhesiveness and Easy Peelability

[0009] In addition, when the adherend is a metal such as SUS (stainless steel), although the acrylic adhesive tape with the acrylic component added shows high adhesive performance under normal conditions, the adhesive force increases after heating, and it is difficult to obtain good easy peelability.

In addition, there is also the problem that the acidic component corrodes the adherend

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