Sulfuric Acid → Diurea silicate

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Reaction Steps

Clay is reacted with sulfuric acid, thereby producing metasilicic acid, which is recovered by filtration. About one mol of said metasilicic acid is mixed with 2 mols of urea, heated to 90° to 150° C. for 20 to 30 minutes, thereby producing white granules of diurea silicate. The said diurea silicate is added to an aqueous solution of hexamethylene tetramine in the ratio of 1:1.5 mols, heated to 70° to 110° C. for 20 to 90 minutes, thereby producing a clear thick solution of poly (formaldehyde diurea silicate) resin, and, upon further heating, a white resin is produced. The said white resin is soluble in acetic acid and produces a clear solution; the unreacted silicic acid is precipitated. The solution of poly (formaldehyde diurea silicate) resin forms a clear tough coating on wood.

Provenance & Evidence