2019 Volume 55 Issue 3 Pages 88-96
The purpose of this study is clarifying the contamination source and suitable cleaning method of stainlesssteel（ SS） standard adherend for peel test of pressure-sensitive adhesives（ PSA）. For this purpose, fourkinds of PSA tapes consisting of rubber, polyacrylic polymer, styrenic block copolymer and silicone polymeras base polymer and SS foil as model adherend were used. Two kinds of cleaning methods were employedbefore peel test: the heat cleaning（ the SS foil was wiped with nonwoven fabric containing methyl ethyl ketonethree times → the same process with toluene was done → heated at 175 °C for 1 h → the cleaning withmethyl ethyl ketone and toluene was repeated） and the ultrasonic cleaning in toluene for 1 h. As a result, thepeel strength increased after the heat cleaning for three kinds of tapes, on the other hand, hardly increasedafter the ultrasonic cleaning. From the X-ray photoelectron spectroscopy（ XPS） analysis, the content ratioof C element on SS foil surface was high even after the cleaning process. Further, it increased by the storageat room temperature. The estimated contamination source was the lubricating oil used in the cold-rolling ofSS. It was confined in the surface concave portion during the cold-rolling process and oozing out throughsurface fine pores gradually. It was found that the heat cleaning was effective for lessening the influence ofcontamination.
