Epoxy resin is a kind of polymer, the molecular formula is (C11H12O3)n, refers to a kind of polymer containing more than two epoxy groups in the molecule. It is A polycondensation product of epichlorohydrin and bisphenol A or polyols. Due to the chemical activity of epoxy group, it can be opened by a variety of compounds containing active hydrogen, curing crosslinking to form a network structure, so it is a thermosetting resin. Bisphenol A type epoxy resin not only has the largest yield and full variety, but also the new modified varieties are still increasing, and the quality is constantly improving.
Epoxy resins have a secondary hydroxyl group and an epoxy group, and the secondary hydroxyl group can react with isocyanate. Epoxy resin as a polyol is directly added into the component containing the hydroxyl group of polyurethane adhesive. In this method, only the hydroxyl group takes part in the reaction, while the epoxy group does not react.
At present, the classification of epoxy resins has not been unified. Generally, they are classified according to strength, heat resistance grade and characteristics. There are 16 main varieties of epoxy resins. Including general adhesive, structural adhesive, high temperature resistant adhesive, low temperature resistant adhesive, water and wet surface adhesive, conductive adhesive, optical adhesive, spot welding adhesive, epoxy resin film, foam adhesive, strain adhesive, soft material bonding adhesive, sealant, special adhesive, latent curing adhesive, civil construction adhesive 16 kinds.