Material characteristics

Epoxy resin has secondary hydroxyl groups and epoxy groups, which can react with isocyanates. Epoxy resin, as a polyol, is directly added to the hydroxyl containing component of polyurethane adhesive. Using this method, only the hydroxyl group participates in the reaction, and the epoxy group fails to react.

Use the carboxyl group of acidic resin to open the epoxy ring, and then react with isocyanate in polyurethane adhesive. It is also possible to dissolve epoxy resin in ethyl acetate, add phosphoric acid for heating reaction, and add its adduct to polyurethane adhesive, which can improve the initial adhesion, heat resistance, and hydrolysis stability of the adhesive. Polyols can also be generated through alcohol amine or amine reactions, and the presence of tertiary nitrogen atoms in the adduct can accelerate the NCO reaction.

The use of epoxy resin as a multi hydroxyl component combines the advantages of polyurethane and epoxy resin, which has good bonding strength and chemical resistance. The epoxy resin used for manufacturing polyurethane adhesives generally adopts varieties such as EP-12, EP-13, EP-16, and EP-20.

Modification method

1. Select curing agent;

2. Add reactive diluent;

3. Adding fillers;

4. Add special thermosetting or thermoplastic resins;

5. Improve the epoxy resin itself.