Polymer Photochemistry 4 (1984) 451-458 Effect o| Monomer Composition on the Adhesion ot Pressure-sensitive Adhesives Prepared by Photoinitiated Polymerization Robert A. Shankst and Stephen R. Clarke$ Department of Applied Chemistry, Royal Melbourne Institute of Technology, Melbourne, Australia (Received: 11 August 1983) ABSTRACT A method has been developed for preparing pressure-sensitive adhe- sives directly on the backing substrate by photoinitiated polymeriza- tion. Oxygen inhibition is prevented by a transparent covering film which can then be peeled off prior to application of the adhesive to a substrate. The adhesive strength can be increased by incorporation of a crosslinking monomer, to improve cohesive strength, and a polar monomer, to increase interactions with the substrate surface. A range of each of these monomer types was tested. Adhesives have been prepared by this technique which have equal or better adhesive strength than a range of commercial pressure-sensitive tapes. INTRODUCTION Photoinitiated polymerization has found many applications in inks and coatings products. The applications require that the polymeriza- ble composition has the form of a thin layer which can readily be penetrated by ultraviolet radiation. 1 Adhesives are generally set between the substrates and so are not accessible to the ultraviolet radiation. Pressure-sensitive adhesives are a special category where t Author to whom correspondence should be addressed. Present address: Nonporite Pty. Ltd, Hawthorn, Victoria, Australia. 451 Polymer Photochemistry 0144-2880/84/$3-00 (~) Elsevier Applied Science Publishers Ltd, England, 1984. Printed in Northern Ireland