GB891009A - Carbamic esters - Google Patents

Abstract

Carbamic esters are prepared by reacting a polyisocyanate with a phenol and a polyethenoxy monohydric alcohol, the reactants being mixed, simultaneously or consecutively in either order, in p such proportions that the products have no free-NCO groups and contain at least one carbamic ester group derived from the phenol and at least one carbamic ester group derived from the polyethenoxy alcohol. In Example 1, a mixture of phenol and a condensate of 1 mol of glycol monomethyl ether with 10 mols of ethylene oxide is made just acid to Congo Red with a solution of dry HCl in ethyl acetate. This mixture is then slowly added to 2,4-tolylene di-isocyanate, stirred at 100 DEG C. under a nitrogen atmosphere. The mixture is then heated at 165 DEG C. for 2 hours. On cooling, a viscous syrup is obtained as product. In Example 3, the condensate referred to in Example 1, is first reacted alone with tolylene di-isocyanate, and the intermediate product is then reacted with the phenol; while in Example 4, the phenol is first reacted with the di-isocyanate, and the intermediate product is then reacted with the condensate. In Examples 5 and 6, dichlorophenol and 4-hydroxydiphenyl, respectively, are used in place of phenol. In Example 7, a condensate of cetanol and ethylene oxide is used. A list of suitable polyisocyanates is given. Among the other phenols which may be used in the reaction are: methoxyphenols, 1 - and 2-naphthols, hydroquinone and resorcinol. The carbamic ester products may be used as coating agents for textiles (see Group VIII).