The Preparation and Adhesion Performances of Transparent Acrylic Pressure Sensitive Adhesives Containing Acrylamide Monomer for Optical Applications

Abstract

Transparent acrylic pressure sensitive adhesives (PSAs) were successfully prepared by photopolymerization with 2-ethylhexyl acrylate (2-EHA) and 2-hydroxyethyl acrylate (2-HEA) as a default constituent and with isobornyl acrylate (IBOA) and N-(isobutoxymethyl)acrylamide (IBMA) as a variable constituent. The IBMA mole fraction effect in the acrylic PSAs was investigated on adhesion performances and the optical properties including 85/85 test as well as the characteristics (solid content, and molecular weight) of the PSA syrups were also investigated. Regardless increasing the IBMA mole fraction in the acrylic PSAs, the acrylic PSAs exhibited almost the same adhesion performance such as <TEX>$180^{\circ}$</TEX> peel strength (~4.0 kg/25 mm) and probe tack (~0.27 kg). All the acrylic PSA samples also showed high transmittance (more than 91%), low haze (less than 1.0%) and low color-difference (less than 1.0) before and after 85/85 test.