| abstract |
(57) [PROBLEMS] To prepare THPE from phenol and 2,4-pentanedione, the reaction time is within 24 hours and the temperature is set to a temperature which minimizes a side reaction consuming 2,4-pentanedione. TH in a yield of at least 55% of theoretical Development of new methods to provide PE products. SOLUTION: 1,1,1-Tris (4-hydroxyphenyl) ethane, which is a branching agent for polycarbonate, contains sulfuric acid and at least one mercaptosulfonic acid such as 3-mercaptopropanesulfonic acid as a promoter. Prepared by reaction of phenol with 2,4-pentanedione below. By using the promoter and sulfuric acid in specific proportions, a high product yield can be obtained in a relatively short time. |