2019 年 68 巻 1 号 p. 20-25
We have succeeded in clarifying the influence of thermo-sensitive adhesive IntellimerTM consisting of polyacrylic acid whose main chain is polyacrylic acid and crystalline olefin with side chain on the surface structure and internal structure by tackifier by precise structural analysis. It was found that the tackifier has a role of controlling the peel properties after the high temperature treatment. For the case of the tackifier of polymerized rosin ester, it was found that the tackifier precipitates in granular-type form on the surface, and the size of the granular-type form structure increases as the concentration increases. The granular-type form structure did not show a large change even after the heat treatment, indicating that the granular structure precipitated on the surface had an influence on the peeling characteristics. On the other hand, in the internal structure, it was found that the tackifier, that is, the polymerized rosin ester was dissolved in the olefin portion of the side chain and had a large influence on the crystal structure and the nanometer scale structure. Furthermore, we discussed the case of the tackifier of a styrene oligomer having high heat resistance. In the heat treatment up to 200 °C, a scaly surface structure was observed, but a granular structure was observed on the surface by heat treatment at 250 °C. It was found that the heat treatment by high temperature caused the tackifier to precipitate more clearly and to improve the peelability after cooling. In the nanoscale structure, the styrene oligomer is present mainly in the olefin portion of the side chain from temperature dependence of the size of the phase separation.