Effect of the stress relaxation property of acrylic pressure‐sensitive adhesive on light‐leakage phenomenon of polarizer in liquid crystal display

The acrylic pressure‐sensitive adhesive systems with the different stress relaxation abilities are prepared by varying the curing agent from 0.3% to 3.0% and the effect of the stress relaxation ability of pressure‐sensitive adhesive system on the durability of LCD polarizer was investigated. The stress relaxation ability of the crosslinked pressure‐sensitive adhesive systems was measured by transient tensile test and dynamic viscoelastic test. And the durability was evaluated by the light‐leakage test of polarizer coated with the pressure‐sensitive adhesive after it was aged under the condition of 60°C and the relative humidity of 95% for 72 h. It was observed that the stress relaxation ability of pressure‐sensitive system is decreased with the crosslinking density, as intended. And the pressure‐sensitive adhesive with the lower stress relaxation ability exhibited the lower light‐leakage and consequently the higher durability than the other PSA systems. This observation is obviously contradictory to the previous design strategy of PSA system and the reason for this observation was discussed briefly. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007