| 摘要 |
PURPOSE:To obtain a flame-retarded curable cyanate ester resin which is free from a solvent and uniformly mixed, by adding a halogenated polycarbonate oligomer to a polyfunctional cyanate ester at an initial stage of the reaction and subjecting the mixture to a melt reaction. CONSTITUTION:In the production of an oligomer comprising reacting a polyfunctional cyanate ester with a polyfunctional maleimide with stirring in a molten state at 80-200 deg.C for 0.5-20hr, a ring -halogenated arom. polycarbonate oligomer is added at an initial stage of the reaction or at a point at which the viscosity of the reaction mixture is 100 poises or lower. Examples of said ring- halogenated polycarbonate oligomers are those of the formula wherein R<3> is bivalent lower alkyl, phenyl-substd. lower alkyl; Y<1>, Y<2> are each Cl, Br; q1, q2 are each 1-4; p is 2-30. The oligomers in which end groups are stabilized are preferred. |
