2015 Volume 51 Issue 2 Pages 49-57
Among the methods which does not use an organic solvent, the hot-melt method exhibits high productivitybut is somewhat limited in terms of performance. In order to resolve the disadvantages of conventional hot-melt pressure-sensitive adhesives, we have proposed thermally processable pressure-sensitive adhesives with a completely new structure which have the isocyanate dimer structure. Thedimer was known to dissociate to isocyanate at high temperature. In this report, in order to check thecompatibility of this system in industrial process, we estimated the material liquidity on the heatingby the Laboplast mill manufactured by Toyo Seiki, and we tried to make a pressure sensitive adhesivesheet by the extrusion machine on laboratory scale. We found that liquidity was dependent on thequantity of a heat dissociation part. And also we found that liquidity was dependent on the structureand quantity of the polyol which added in this process. In order to control a liquidity change in process,it was effective to reduce the ratio of the polyol having higher OH groups. By the examinationusing an extrusion machine, it was cleared to be able to apply a pressure-sensitive adhesive on a basematerial continuously. From these results, it was suggested by the new mechanism based on dissociationof a chemical bond that it is possible to produce a pressure sensitive adhesive sheet industrially.
