Dry epoxy resin adhesive composition and process for preparing same

A pulverulent composition of a polyepoxide, a salt of a polyamine, and a strong base may be prepared by absorbing a liquid polyepoxide and a salt of a polyamine on a finely divided filler, and mixing the two products together with a strong base e.g. sodium or potassium hydroxide. Addition of a solvent, e.g. water or ethylalcohol for the amine salt and the base activates the composition which may be used as an adhesive, particularly for tiles. A suitable filler is a mixture of sand with a silica aerogel. In Examples I and VI crystals of diethylene triamine hydrochloride and powdered sodium hydroxide were mixed with sand and silica aerogel on which a liquid polyepoxide of formula: had been absorbed to yield stable free-flowing powders, which mixed with water could be trowelled on to a concrete floor as an adhesive bed for ceramic tiles. II and III are similar but use an adsorbate of N-octadicyl trimethylene diamine hydrochloride on silica aerogel. IV the acetate of N-octadecyl trimethylene diamine was cured. V the phosphate of the same diamine was used. VII is similar to II and III but uses a polyepoxide of formula: VIII is similar to II and III but uses Wollastonite in place of sand, and includes TiO2 to give a white finish. Other examples illustrate the use of the hydrochlorides of bases available commercially under the Trade Name "Duomeen". Specification 718,850 is referred to.