| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method in which formaldehyde can be efficiently removed from a crude thinner before secondary distillation to further reduce its content without using sodium borohydride, in a method for regenerating a recycled thinner from a waste coating material. Ž<P>SOLUTION: The recycled thinner is regenerated from the waste coating material by the steps of: adding sodium hydroxide to a crude distillate of the waste coating material followed by stirring the mixture to recover an organic layer having a formaldehyde concentration of 1 ppm or less; and subjecting the organic layer to secondary distillation to obtain a purified product. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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