Reversible adducts of isocyanates with boron compounds

A process for storing and obtaining an isocyanate having the formula:

• R--N.dbd.C.dbd.O
• wherein R is a member selected from the group consisting of alkyl having from 1 to 10 carbon atoms and alkenyl having from 2 to 6 carbon atoms, consisting of the steps of reacting a carbonyl group containing compound selected from the group consisting of an isocyanate having the formula
• R--N.dbd.C.dbd.O
• wherein R is a member selected from the group consisting of alkyl having from 1 to 10 carbon atoms and alkenyl having 2 to 6 carbon atoms, and a carbamoyl chloride having the formula ##STR16## wherein R has the above assigned values, with a boron compound having at least one free .dbd.B--OH group selected from the group consisting of (a) polyol borates essentially free of alcoholic hydroxyl groups prepared from boric acid and polyols having at least two alcoholic hydroxyl groups selected from the group consisting of (i) compounds having the formula ##STR17## wherein R.sub.1 is a member selected from the group consisting of hydrogen, lower alkyl, and hydrocarbon aryl, n is 0 or an integer from 1 to 4, and m is 0 or an integer from 1 to 5, (ii) pentaerythritol, (iii) lower alkyl ethers of (i) or (ii), and (iv) lower alkanoic acid esters of (i) or (ii), and (b) metaboric acid, either in the presence or absence of a solvent inert to isocyanate, to form an adduct, maintaining said adduct at temperatures below the decomposition temperature for the time desired, and heating said adduct to decompose the same with evolution of said isocyanate as a vapor.