Abstract: Aqueous dispersions of aromatic polyisocyanates blocked with phenolic compounds are prepared by mixing the polyisocyanate and an aqueous solution containing an excess of the phenolic compound in the presence of a basic catalyst at a temperature above the melting point of the polyisocyanate.

Abstract: A process for the preparation of blocked polyisocyanate powders consisting of reacting the polyisocyanate and blocking agent in solution in the presence of a surfactant, whereby the product precipitates in extremely finely divided form.

Abstract: Aqueous dispersions of aromatic polyisocyanates blocked with phenolic compounds are prepared by mixing the polyisocyanate dissolved in an organic water-soluble solvent and an aqueous solution containing an excess of the phenolic compound in the presence of an alkali metal hydroxide catalyst. When the phenolic compound is resorcinol, the excess resorcinol in the dispersion may be reacted with formaldehyde to form a resorcinol-formaldehyde resin; when the phenolic compound is phenol, excess resorcinol may be added and formaldehyde reacted with it to form the resorcinol-formaldehyde resin, a polyepoxide and a rubber latex may be also dispersed thus forming a dispersion that may be used to form single dip adhesive coatings on polyester substrates which will adhere to rubber.