Force curve measurement of thin polydimethylsiloxane (PDMS) release layers was performed to estimate mechanical properties with atomic force microscopy (AFM). In addition, the relationships between mechanical properties and release force in the release layers were examined. The release layers having different organosiloxane content were formed on the PET substrate and their force curves were measured by AFM. The values of Young’s modulus and adhesive energy from these force curves in the release layers were calculated using JKR theory. An increase in the value of Young’s modulus was observed with an increase in the content of organosiloxane compound. Furthermore, a high correlation between Young’s modulus and release force was found. Therefore, it was suggested that Young’s modulus of the release layer influences the value of the release force of a model PSA. As a result, it was concluded that these measurements and analyses are extremely useful for the direct estimation of the mechanical properties of PDMS release layers.

In this study, in order to investigate experimentally cyclic torsion deformation behavior of acrylic adhesive, the torsion test of highly ductile acrylic adhesive with butt joint specimen was carried out under various testing speeds. The constitutive equation was proposed to consider the characteristic of shear stress-strain curve obtained by experiments, and was compared with numerical analysis. The acrylic adhesive shows the cyclic work softening behavior before the shear stress-strain curve obtained by the cyclic torsion test closed to that by the torsion test. The bauchinger effect and the increasing shear stress were indicated with increasing strain rate. The work softening at various shear strain rates could be almost described by viscoplastic constitutive model. It was also found at other results. It will be discussed the change of shear strain started inverse warping future.