| 摘要 |
PURPOSE:Title laminated sheets, excellent in high-frequency electrical characteristics, humidity resistance and dimentional stability, formed by impregnation of base materials with a mixture of a butadiene polymer, a bismaleimide compound and a specified flame retardant in the presence of an organic peroxide, followed by laminate molding. CONSTITUTION:The mixture of (A) a butadine polymer containing >=50% of 1,2- butadiene unit with side chain double bonds in the polymer chain and (B) a bismaleimide compound of formula I (R is 2C or higher bivalent hydrocarbon group) with (c) a flame detardant selected from (a) 2,4,6-tribromophenyl compounds of formula II-IV (X is H or CH3) and (b) compounds of formula V [X is Br or Cl: Y is H or CH3: A is -, -0-, -CO-, -SO2-, -(CH2)5, -CH=CH- or formula VI: m, n, b are 1-4] having tow (meth)acryloly groups in the molecule, is dissolved in an organic solvent, and an organic peroxide is added to the resulting solution to prepare a varnish. Base materials are impregnated with the varnish, which are laminate molded and hot-cured to give laminated sheets. |
