Preparation of biuret polyisocyanates

A process for the preparation of biuret polyisocyanates which comprises reacting at a temperature of from about 60.degree. to about 210.degree. C diisocyanates and up to about 0.4 mol per mol of diisocyanate of a tertiary alcohol selected from the group consisting of tertiary butyl alcohol, 2-methyl-2-butanol, 2-methyl-2-pentanol, 3-methyl-3-pentanol, 3-ethyl-3-pentanol, 1-methyl cyclopentanol, 1-methylcyclohexanol, 1-ethylcyclohexanol and 1,1-dimethylallyl alcohol in the presence of from about 0.001 to about 0.1 mol per mol of tertiary alcohol of a catalyst selected from the group consisting of ammonium chloride and hydrochloride acid salts containing between 1 and 8 carbon atoms derived from nitrogen containing aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic bases and wherein the nitrogen atoms of said bases are primary, secondary, or tertiary.

A process for the preparation of biuret polyisocyanates which comprises reacting at a temperature of from about 60.degree. C to about 210.degree. C diisocyanates and up to about 0.4 mol per mol of diisocyanate of a tertiary alcohol selected from the group consisting of tertiary butyl alcohol, 2-methyl-2-butanol, 2-methyl-2-pentanol, 3-methyl-3-pentanol, 3-ethyl-3-pentanol, 1-methyl cyclopentanol, 1-methylcyclohexanol, 1-ethylcyclohexanol and 1,1-dimethylallyl alcohol in the presence of from about 0.001 to about 0.1 mol per mol of tertiary alcohol of a catalyst wherein the catalyst is a mixture of N,N-dimethylhydrazine hydrochloride and dimethylamino hydrochloride.

A process for the preparation of biuret polyisocyanates which comprises reacting at a temperature of from about 60.degree. C. to about 210.degree. C. diisocyanates and up to about 0.4 mol per mol of diisocyanate of a tertiary alcohol selected from the group consisting of tertiary butyl alcohol, 2-methyl-2-butanol, 2-methyl-2-pentanol, 3-methyl-3-pentanol, 3-ethyl-3-pentanol, 1-methyl cyclopentanol, 1-methylcyclohexanol, 1-ethylcyclohexanol and 1,1-dimethylallyl alcohol in the presence of from about 0.001 to about 0.1 mol per mol of tertiary alcohol of a catalyst consisting of ammonium chloride, methylammonium chloride, dimethylammonium chloride, trimethylammonium chloride, ethylammonium chloride, diethylammonium chloride, propylammonium chloride, n-butylammonium chloride, di-n-butylammonium chloride, stearyl-methylammonium chloride, dimethylbenzylammonium chloride, and the hydrochloride salts of morpholine, piperazine, N-aminomorpholine, N-amino-N-methylpiperazine and N,N'-diaminopiperazine and mixtures of these catalysts.

The process of claim 11 wherein the catalyst is selected from the group consisting of diethylammonium chloride, dimethylammonium chloride, N,N'-dimethylhydrazinium chloride, triethylammonium chloride, dimethylbenzylammonium chloride and mixtures of these catalysts.