Abstract: A curable thermosetting resin composition, including a multicomponent copolymer and an epoxy resin. The multicomponent copolymer is a ternary or quaternary copolymer having structural units selected from the group consisting of unit (I), unit (II), unit (III) and (IV). The structural unit (I) is the structural unit (II) is the structural unit (III) is and the structural unit (IV) is where m, n, r and s are natural numbers denoting the molar fraction of corresponding building blocks in the copolymers respectively, R is selected from the group consisting of hydrogen, aromatic group and aliphatic group, and AR is an aromatic group; and the epoxy resin is one or more selected from a group consisting of aromatic epoxy compound, alicyclic epoxy compound and aliphatic epoxy compound.

Abstract: The present invention relates to a curable thermosetting resin composition including a multicomponent copolymer of monomers represented by general formulas (I), (II), (III) and (IV), an epoxy resin, a curing agent, etc. In the present invention, the phosphorus element is creatively introduced into a ternary or quaternary copolymer that is capable of undergoing a cross-linking reaction with an epoxy resin, and the ternary or quaternary copolymer is mixed with the epoxy resin and the like to form a composition meeting all the requirements that the cured product has a high glass transition temperature, a low dielectric constant and dielectric loss factor, and a certain flame resistance. The multicomponent copolymer is prepared through two methods, in which one method includes direct copolymerization of corresponding monomers and the other method includes initial copolymerization with a hydroxyl-containing monomer and the following esterification with phosphoric acid.