The purpose of Sealer/Rejuvenators are to:

    Shield the asphalt from sunlight (UV rays)

    Provide resistance to gasoline and other petroleum products

    Reduce the viscosity of the asphalt

    Restore the asphalt's flexibility

    Increase the binder quality of the asphalt

Click on links below for Sealer details:

FAA Engineering Brief 44 for Coal-Tar Sealer Rejuvenator

Sealer Types - Benefits and Costs

CBRT-S0  Asphalt Sealer