Epoxyalkyl Ester Adhesives

Glycidyl compounds can be made by the reaction of epichlorohydrin with a substance other than an amino or hydroxyl compound, and the products of reaction with polycarboxylic acids or anhydrides known as epoxyalkyl ester are of some interest. These resins, wherein the important functional groups are epoxide, are quite unlike the polyester referred to.

In the development of the epoxyalkyl ester adhesives, Henkel and Cie of Germany have been prominent. Epoxyalkyl esters can be prepared by reacting a halide of a polybasic aromatic carboxylic acid with an epoxide compound containing a hydroxyl group such as glycidol, also by reacting a salt of such an acid, or the acid or anhydride itself in the presence of a catalyst with epichlorohydrin.

Adhesives based on epoxyalkyl esters can be hardened with aliphatic polyamine, or with an acid or acid anhydride. They show good adhesion to a wide veriety of materials including glass, marble, porcelain, rubber and metals, and they are resistant to hot and cold water. An example of the metal to metal strength of both a hot-cured and a room temperature cured epoxyalkyl ester is shown in the figure,.