Adhesion properties of electron-beam cured oligomers for pressure-sensitive-adhesives

The properties of non-solvent pressure-sensitive-adhesives of the cured oligomers were studied with relation to their structure. Two types of liquid oligomers having certain double bonds, namely the side-chain and telechelic types, were employed for the test. The telechelic pure oligomer was cured in lower concentration of double bonds than the side-chain oligomer. Peel strength of the oligomers was almost the same. In the addition of mercapto-functional chain transfer agent, however, the telechelic type resulted in remarkably better peel strength compared with the side-chain. Thus, it is suggested that, in the case of the telechelic oligomer, the polymerizing or crosslinking by ene-thiol addition occurs effectively, and the adhesives indicate rubberlike elasticity. (author)