Process for the preparation of polycarbonate polyols

Abstract

The present invention provides a novel process for preparing specified amorphous polycarbonate polyols. The process comprises reacting phosgene, a branched-chain polyhydric alcohol, and a straight chain polyhydric alcohol in the presence of a solvent and in the absence of a catalyst at a temperature of about 60.degree. to 100.degree. C., and then contacting the amorphous polycarbonate product in the reaction mixture with a catalytic amount of a tertiary amine at reflux temperature for a period of time of at least about 30 minutes. The straight chain polyhydric alcohol is employed in an amount of about 3 to 40 mole percent, based upon the total amount of polyhydric alcohol present in the reaction system. A preferred branched-chain polyhydric alcohol is neopentyl glycol, and a preferred straight chain polyhydric alcohol is 1,6-hexanediol. Preferred solvents are xylene and toluene, and preferred tertiary amines are triethylamine and pyridine.

Dependencies are inferred from the claim text.