The use of acrylic pressure sensitive adhesives (PSAs) in flexible displays involves their attachment to each layered device. Due to the high industrial demand of flexible displays, acrylic PSAs must necessarily exhibit high flexibility. The effect of the crosslinking density of acrylic PSAs on their adhesion and flexibility properties has been investigated by incorporating a diisocyanate crosslinking agent into the PSA structure. As the content of the crosslinking agent increased, the measured peel strength and tack of the synthesized PSAs decreased, while the maximum value of the lap shear stress increased. In addition, the maximum stress and shear strain determined for the crosslinked PSA specimens decreased with an increase in the crosslinking agent concentration. The obtained data indicate that crosslinking generally improves the PSA properties related to their use in flexible display applications; however, very high crosslinking densities produce mostly a negative effect on the PSA flexibility and adhesion characteristics.
Volume 74, April 2017, Pages 137–143