Preparation of aqueous dispersions of blocked aromatic polyisocyanates
AssigneeE. I. Du Pont de Nemours and Company
InventorCarl Albert Aufdermarsh, Jr.
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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.
Claims8
A process for the production of an aqueous dispersion of an aromatic polyisocyanate blocked with a phenolic compound which comprises mixing (a) an aromatic polyisocyanate and (b) an aqueous solution containing a dissolved phenolic compound selected from the class consisting of phenol, resorcinol and C.sub.1 to C.sub.15 alkyl derivatives of phenol and C.sub.1 to C.sub.15 alkyl derivatives of resorcinol, at a temperature above the melting point of the polyisocyanate, in the presence of an effective amount of a basic catalyst, the number of moles of phenolic compound being at least equal to the number of equivalents of isocyanate groups present.
Dependencies are inferred from the claim text.