| abstract |
An uncured adhesive contains 2 to 10 weight percent of particles of a semi-crystalline organic material, preferably a polyester having a number-average molecular weight of 2000 to 10,000, a hydroxyl number of 10 to 60, and a melting temperature of 50 to 125 °C. The adhesive is applied by heating it just prior to application, to melt the particles. After application, the adhesive is cooled to below the melting temperature of the semi-crystalline organic material, and then cured. The process allows the adhesive to be stored and pumped at ambient temperatures, due to the moderate viscosity of the material. Upon melting and re-cooling the semi-crystalline organic material, the adhesive assumes a high yield stress that imparts very good wash-off resistance. In preferred embodiments, the adhesive composition includes an epoxy resin and an epoxy curing agent. |