Abstract
Recently many crystalline intermediates of phenol-and urearesins have been isolated or synthesised. When they melt, often “thermosetting” or “decomposition” take place, according to the property of their parental resins. As the example of such abnormal melting point, first the following intermediates of phenol-resins are discussed : five phenolalcohols, 2, 4-and 2, 6-dimethylphenol-monoalcohols, four-ring-novolaks and dioxy-diphenyl-methane-tetraalcohols. Next from urea-resins : dimethylol-and methylene-urea and hydrochloric acid catalysed urea-and thiourea-resins. Lastly the articles of O. Diels and R. Lichte (1926), and A. E. Dixon (1918) are introduced from the historical standpoint of the urea-resin chemistry.
