Bisphenol A liquid epoxy resin (DGEBA type)
The standard liquid epoxy resin found in floors, primers, linings and composites the world over: superb adhesion and chemical resistance, but not UV-stable.
Standard liquid epoxy resin is made by reacting bisphenol A with excess epichlorohydrin. The product is mostly the diglycidyl ether of bisphenol A (DGEBA) with a small fraction of higher oligomers, giving an EEW of about 182–192 g/eq and a viscosity of roughly 11,000–15,000 mPa·s at 25 °C.
BPA liquid epoxy is the base resin for floor coatings and self-levelers, concrete and steel primers, tank and pipe linings, adhesives and fiber-reinforced composites. It is often blended with BPF resin or reactive diluents to lower viscosity.
Two epoxide groups per molecule react with amine hardeners to form a dense, crosslinked network. The aromatic bisphenol backbone gives rigidity, adhesion and chemical resistance, but absorbs UV light, causing chalking and yellowing outdoors. Standard resins can also crystallize when stored cold.
Uncured epoxy resin is a skin and eye irritant and a common cause of allergic contact dermatitis. Avoid all skin contact. EU rules now restrict BPA in food-contact coatings, so check regulatory status for such uses.
Standard BPA epoxy can crystallize at low temperatures. Gently warming the container (around 50–60 °C) and stirring usually redissolves the crystals.
It works as a primer or intermediate coat outdoors but chalks and ambers in sunlight, so it is normally topcoated with a UV-stable polyurethane or polyaspartic.
