To evaluate the shearing properties of pressure sensitive adhesive (PSA) in the micro deformation range, a higher resolution test apparatus has been developed. The test apparatus can measure the micro displacement caused by a shear load with maximum resolution of 0.08 nm by specification of laser interferometer. By this apparatus, the shear displacement of an acrylic PSA was measured under very low shear load. The influences of cross-linking agent ratio of the specimen and the adherend temperature on the micro shear properties were evaluated as static shear properties using the coefficients of viscoelastic model. As a result of statistical analysis, the interaction between the cross-linking agent ratio and adherend temperature properties became highly loading time dependent.In addition, the dynamic test with bulk specimens was carried out for comparison with the static shear properties using the new test apparatus. In the exponential displacement stage, which is characterized by elastic and viscosity behavior, adherend temperature dependence of the static shear property is approximately shown similar profiles to the effects caused by measurement temperature for storage and loss modulus by the dynamics viscoelastic test. By these results, it has bee nsuggested that the new test apparatus is useful for evaluating the micro shear properties of PSA with loading time.
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