Asphalt & bitumen adhesives are low cost thermoplastic formulations that generally consist of asphaltic resin compounded with thermoplastic rubber such as butyl or polyisobutylene. These adhesives are inherently tacky. Adhesion is very good to a wide variety of materials, such as concrete, glass, metal, and paper products.
Asphalt adhesives should be used only where there is little or no stress. Bond strengths are low and fall rapidly as temperature is raised. The high temperature properties of asphalt adhesives are dependent on the particular asphalt used and on the compounding of the adhesive. Water and alkali resistance of asphalt adhesives are very good. Thick films are impermeable to moisture vapor. Oils, greases, and common solvents will soften asphalt products.
Water emulsion, solvent solutions, and hot melts are widely used forms of asphalt adhesives. Such mixtures are useful as sealants, but asphalt emulsions have also been used for laminating paper and other packing materials where a water barrier is needed. They are used in many applications where strength is secondary to resistance to water; alkali, or acid. Hot melts have been used for bonding insulation and for lamination of paper and foil. Emulsions have been used as binder, in roads, for installation of asphalt tile, and for bonding of waterproof packages. Another important application is in low cost roofing and flooring.