Process for the preparation of highly esterified alkoxylated polyol compositions

Reference Number: N 04-04

Inventors: Cooper, Charles F.

USPTO Link: 5399728

Invention Summary

This invention provides a process for producing a highly esterified alkoxylated polyol composition comprising contacting an epoxide, an alkali metal or alkaline earth salt of a aliphatic polyalcohol, and a triglyceride for a time and at a temperature effective to accomplish ring-opening of the epoxide and formation of fatty acid-esterified oxyalkylene groups. The ratio of the number of moles of epoxide to the total number of moles of triglyceride and aliphatic polyalcohol is from 1:1 to 64:1 and the molar ratio of triglyceride:aliphatic polyalcohol must be at least 9:3/m (more preferably, at least 19:3/m) wherein m is the number of hydroxyl groups in the aliphatic polyalcohol and is typically an integer of from 2 to 8. The process readily affords esterified alkoxylated polyol compositions wherein at least 90% (more preferably, at least 95%) of the end groups are acyl groups rather than hydroxy groups (i.e., the degree of esterification is 90 percent or greater).

The effectiveness of the process of this invention was unexpected since related reactions described in the prior art either require relatively low triglyceride:alcohol ratios or utilize an alkaline catalyst which is a component distinct from the alcohol and not associated with the alcohol as a salt. Moreover, the prior art failed to adequately characterize or describe the structures of the compounds thereby obtained, particularly the degree of esterification achievable. In contrast, we have discovered that by carefully controlling the relative ratios of epoxide, triglyceride, and polyalcohol salt and by deploying the polyalcohol in salt form it is possible to maintain surprisingly high rates of reaction while affording highly esterified products containing low levels of undesired organic impurities, unreacted triglyceride, and unreacted polyalcohol.