Generally, pressure-sensitive adhesives used for labeling on window glass and inorganic materials are required to have long-term durability under high temperature and humidity. It is well known that adhesive properties of pressure-sensitive adhesives are improved by the addition of silane coupling agents. So, it would be possible to control adhesive properties by analyzing dispersion behavior of silane coupling agents in the adhesive sheet. Nevertheless, the knowledge on the thorough roles of silane coupling agents has been scarcely presented as far as we know. Therefore, in this paper, we will report on an examination of the relationship between dispersion behavior of silane coupling agents in adhesive sheets and peel strengths. Adhesives were prepared by mixing acrylic ester copolymers, cross-linkers, and (3-glycidyloxypropyl)-trimethoxysilane, which were dissolved in ethyl acetate. Then, adhesive sheets were obtained by coating adhesives on polyester films.These adhesive sheets, containing the different amounts of the silane coupling agents, were analyzed by X-ray photoelectron spectroscopy (XPS) and XPS with sputtering using C60 cluster ions in some cases. The results of the XPS measurements demonstrated that silane coupling agents showed a tendency to localize in the immediate vicinity of the adhesive sheets surface. Furthermore, the peel strengths increased with the amount of the silane coupling agent after allowing sufficient treatment time. These findings suggested that the dispersion behavior of silane coupling agents contributed to the adhesiveness for inorganic materials.

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In this paper, the effects of the thicknesses of adherend and adhesive layer on plastic forming of adhesively bonded sheet metals were investigated by experiments and the corresponding numerical simulation. The adhesive employed in the present work was acrylic adhesive Af-372-20 Hardrock (Denki Kagaku Kogyo, Co., Ltd.). In order to investigate the effect of the adherend thickness, an aluminium alloy sheets A5052P of thickness 0.8 mm, 1.2 mm and 1.6 mm were used for adherends. Furthermore, for the investigation on the effect of the adhesive layer, an aluminium alloy sheet A5083P-0 of 1.0 mm thick was used for adherend. The V-bending experiment (three point bending) was conducted at 23℃, where the punch speed was 1 mm/min and punch travel was 8 mm for all the testings. The main results obtained are as follows: 1) when the thickness of the adherends increases. The gull-wing bend and the shear strain become larger, which in some cases causes the delamination; 2) when the thickness of adhesive layer increases, the gull-wing bend is becomes larger, but the shear strain becomes smaller.

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Tack properties of poly(methyl methacrylate)-block-poly(n-butylacrylate)-block-poly(methy methacrylate) triblock copolymer (MAM) and a 1/1 blend with a diblock copolymer consisting of the same components (MA) were used asbase polymers, and tackifier added systems in amounts ranging from 10 to 30 wt% wereinvestigated in order to clarify the role of MA and tackifier. The temperature dependence of tack was measured by a probe tack test. The tack of MAM/MA at room temperaturewas significantly higher than that of MAM, and the improvement of MAM/MA upon the addition of the tackifier was greater than that of MAM. The peeling process at the probe/adhesive interface during the probe tack test was observed using a high speed microscope. It was found that for MAM/MA, cavitation wascausedin the entire adhesive layer, and peeling initiation was delayed by the absorption of strain energy due to deformation of the adhesive layer. In contrast, for MAM. peeling progressed linearly from the edge to the center of the probe. The greater flexibility of the chain in the diblock copolymer resulted in improved interfacial adhesion. 'H pulse nuclear magnetic resonance analysis showed that the presence of the tackifier reduced the molecular mobility of the base polymers and improved the cohesive strength of the adhesive. Adhesion strength is affected by two factors:the development of interfacial adhesion, and cohesive strength. In the MAM/MA/tackifier system, the presence of MA and the tackifier improved the interfacial adhesion and cohesive strength, respectively. This synergistic effect brought the higher adhesion strength

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