2013 Volume 49 Issue 3 Pages 76-81
The objective of this study is to clarify the factor which influences the rising of tack with contact time in a pressure-sensitive adhesive tape. For this purpose, butyl acrylate-acrylic acid random copolymer with acrylic acid content of 5mol% was crosslinked with various crosslinking agent amounts. Contact time dependencies of tack and fracture energy (work of adhesion) were measured by probe tack test with two different peel rates. In the case of 10mm/s, tack increased with contact time, whereas decreased with an increase in the crosslinking agent amount. The rising rate of tack with contact time decreased with an increase in the crosslinking agent amount. The similar tendency was obtained for the fracture energy. On the contrary, the tendency for 1mm/s was quite different from that for 10mm/s. It was found that the rising of tack with contact time is greatly affected by the crosslinking and the difference in the relative contribution of interfacial adhesion and cohesive strength. Moreover, it was useful to plot the relation between the values of tack and fracture energy for various peeling rate in order to clarify the tack properties.
