Trimethylolpropane color improvement

摘要

The present invention provides a process for improving the color of trimethylolpropane which comprises the steps of a) supplying a crude, aqueous base solution of trimethylolpropane, containing color causing impurities, and having a pH of less than about 9; b) contacting said base solution with an alkaline material for a period of time sufficient to increase the pH of said base solution to greater than 11 and at a sufficient temperature to allow the color causing impurities to react with said alkaline material; c) cooling the resulting solution from step (b) for a sufficient period of time; d) contacting said base solution of step (c) with an organic acid for a sufficient period of time to lower the pH thereof to less than about 9.5; e) extracting the trimethylolpropane from said base solution of step (d ) with an organic solvent; f) separating the trimethylolpropane from said organic solvent; and g) purifying said trimethylolpropane from step f) to form a trimethylolpropane having a phthalic color of less than 0.20 and an acid wash color of less than 8.