1975 年 24 巻 261 号 p. 551-556
Studies on the synthetic thermosetting resins obtained by the reaction of p-sulfoamide-benzamide (SABA) and terephthalamide (TA) with formaldehyde (FA) were carried out.
The results were as follows.
(1) Colorless and transparent SABA resins were synthesized provided that the reaction temperature was more than 100°C and the molar ratio of FA to SABA was not less than 2.5 at the beginning of the reaction. When a proper quantity of ammonia or sodium hydroxide as a catalyst was added under the above mentioned condition, the similar resins were also obtained.
It seemed that the molecular weight of resins tended to be larger in the presence of ammonia, but smaller in the presence of sodium hydroxide than that of resins without any catalysts.
(2) Colorless and transparent TA resins were synthesized provided that the reaction temperature was more than 100°C and the molar ratio of FA to TA was not less than 7.5 at the beginning of the reaction, and that a proper quantity of ammonia was added as a catalyst.
(3) It was found that when the reaction temperature was higher than 140°C at SABA-FA or 150°C at TA-FA system, a hard, infusible and insoluble resin was formed due to relatively larger rate of the reaction.
(4) It was concluded that the relations between molecular weight and softening point of the resins, between molecular weight and reduced viscosity, and between softening point and reduced viscosity were linear.