| 摘要 |
<p>PURPOSE:To obtain the title prepreg with good balance between mechanical strength, flame retardancy and low smoking by providing a polyvinyl alcohol layer on one or both of the surfaces of a thermosetting phenolic resin as impregnated resin. CONSTITUTION:A fibrous cloth consisting of polyamide fiber, polyester fiber, etc., is impregnated with a thermosetting phenolic resin (e.g. novolak-type phenolic resin, resol-type phenolic resin) followed by drying, and one or both of the surfaces of the resin is(are) provided with polyvinyl alcohol layer (s) so as to be (on a solid basis) 10-40 pts.wt. based on 100 pts.wt. of said phenolic resin, thus obtaining the objective prepreg. The polyvinyl alcohol layer's) of the present prepreg is (are) laminated with honeycomb core(s) followed by bonding at 120-150 deg.C into the other objective sandwich panel.</p> |
