| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a phosphorus-modified epoxy resin having a high phosphorus content and improved in flame retardancy, mechanical properties, electrical properties, and storage stability, which comprises structural units derived from an epoxy-containing polyepoxy compound and an organophosphinic or organophosphonous acid and has a specified epoxy value. SOLUTION: A polyepoxy compound having at least two epoxy groups in the molecule is reacted with an organophosphinic acid of formula I or an organophosphonous acid of formula II in a polar aprotic solvent. The equivalent ratio of the epoxy resin to the organophosphinic acid or organophosphonous acid is 1/0. 1 to 1/1. This reaction is performed by heating at 70-100 in the case of an organophosphinic acid or at 80-120 deg.C in the case of an organophospbonous acid until the functional groups are exhausted and further heating the reaction mixture at 150-180 deg.C in the presence of a catalyst. In the formulae, R1 and R2 are each a 1-10C alkyl or a 6-10C aryl. The polyepoxy compound is a compound produced by the polyaddition reaction of an epoxy resin component with a crosslinking component.</p> |
