Debondable adhesive article

Abstract

An adhesive article is described that is debondable from substrates or adherends with the application of heat.

1 . A debondable adhesive article comprising:
 a) a shape memory polymer backing having a first surface and a second surface and having a temporary, deformed shape and pattern of latent projections on the first surface thereof; and   b) an amorphous pressure sensitive adhesive layer coated on patterned surface of the shape memory polymer backing;   wherein on exposure to heat the backing layer recovers to a permanent shape having a pattern of patent surface projections.   
     
     
         2 . The debondable adhesive article of  claim 1  wherein the amorphous adhesive layer has no crystallinity. 
     
     
         3 . The debondable adhesive article of  claim 1  wherein the shape memory polymer of the backing is a crosslinked thermoset polymer. 
     
     
         4 . The debondable adhesive article of  claim 3  wherein the crosslinked thermoset polymer is a dicyclopentadiene copolymer. 
     
     
         5 . The debondable adhesive article of  claim 1  wherein the shape memory polymer is a crystalline thermoplastic polymer. 
     
     
         6 . The debondable adhesive article of  claim 1  further comprising:
 a) a pattern of latent projections on the second surface of the backing; and 
 b) an amorphous pressure sensitive adhesive layer coated on the second surface of the shape memory polymer backing. 
 
     
     
         7 . The debondable adhesive article of  claim 1  wherein the pattern of latent projections comprise solid three and four-sided pyramids, truncated pyramids, cones, cylinders, straight lines, wavy lines, square or rectangular blocks, and hemispheres. 
     
     
         8 . The debondable adhesive article of  claim 1  wherein the article further comprises a resistive heating element embedded therein. 
     
     
         9 . The debondable adhesive article of  claim 1  wherein the depth of the projections is 0.01″ to 0.05″ (0.25 to 1.27 mm). 
     
     
         10 . The debondable adhesive article of  claim 1  wherein on exposure to heat the backing layer recovers to a permanent shape and the projections extend through the adhesive coated surface. 
     
     
         11 . The debondable adhesive article of  claim 1  further comprising an amorphous pressure sensitive adhesive layer coated on the second surface of the backing. 
     
     
         12 . The debondable adhesive article of  claim 1  wherein the article further comprises an induction heating element embedded therein. 
     
     
         13 . A method of preparing the debondable adhesive article of  claim 1  comprising:
 a) providing a shape memory polymeric backing having a temporary, deformed planar shape and latent projections on the first surface of thereof, and 
 b) providing the first surface of the backing with an amorphous pressure sensitive adhesive layer. 
 
     
     
         14 . The method of  claim 13  wherein the adhesive is coated on the backing. 
     
     
         15 . The method of  claim 13  wherein the adhesive is laminated on the backing. 
     
     
         16 . A method of using the debondable adhesive article of  claim 1  comprising:
 a) affixing the adhesive article to a substrate, and 
 b) heating the debondable adhesive article such that the article recovers the permanent shape and the projections become patent, the projections weakening the bond with the substrate. 
 
     
     
         17 . The method of  claim 16  wherein the weakening the bond with the substrate is a reduction in the peel strength. 
     
     
         18 . The method of  claim 16  wherein the weakening the bond with the substrate is a reduction in the shear strength. 
     
     
         19 . The method of  claim 16  wherein the step of heat is induction heating. 
     
     
         20 . The method of  claim 16  wherein the step of heat is resistive heating.