Microwave-activatable hot-melt adhesive

Abstract

A hot-melt adhesive comprising at least one component which under the action of microwaves on the dry hot-melt adhesive leads to an increased heating-up rate compared with a corresponding dry hot-melt adhesive without said component contains with a view to universal application with highest possible activatability and constant property characteristic as microwave-activatable component electrically conductive substances with an electrical conductivity higher than that of the dry hot-melt adhesive without said component. Provided as electrically conductive substances are in particular carbon fibres, carbon black, graphite, antistatic agents and metal particles, either on their own or in mixtures adapted to the use. Hot-melt adhesive coatings or self-supporting hot-melt adhesive films having these additives have a heating-up rate by microwaves which is greater by a factor of up to 400 than that of conventional microwave-activatable adhesives. This results in an appreciable reduction of the consumption of electrical energy when adhering by microwave activation or a corresponding increase in the laying capacity of the material to be stuck. The new hot-melt adhesive is suitable preferably for microwave-activated hot-melt adhering of sheet substrates, in particular floor coverings, and by rendering the activatability largely independent of the water content of usual adhesives also achieves the uniformity and reproduceability of the activation and melting-on behavior necessary for industrial uses and production.

Dependencies are inferred from the claim text.