Abstract: A process for producing an inorganic fiber-based prepreg sheet, which comprises preparing a slurry containing 35-80% by weight of a phenolic resin powder of 0.01-100 .mu.m in average particle diameter, 65-20% by weight of an inorganic fiber (the amounts are based on the total amount of the two) and a nonionic high-molecular fixing agent, making the slurry into a sheet in the same manner as in the paper making, and allowing the sheet to contain a silane coupling agent; and a process for producing an insulating laminate, which comprises laminating a prepreg sheet produced by the above process.

Abstract: A composite material comprising a para-oriented aramide fiber sheet and a thermosetting resin matrix. The composite material is characterized in that the reinforcing para-oiented aramide fiber sheet is pre-treated with a reactive siloxane oligomer prior to impregnation with the thermosetting resin. The reactive siloxane oligomer is represented by the following general formula (1) of: ##STR1## wherein Z is ##STR2## CH.sub.2 --O--, HS, NH.sub.2 -- or CH.sub.2 .dbd.CH--; m is an integer of from zero to 4; n is an integer of from 1 to 9; and R.sub.1 is the same or different groups selected from methyl, ethyl and phenyl.The composite material is improved in electric resistance properties, particularly after being dipped in boiling water, and also improved in thermal resistance to soldering.

Abstract: A zinc-metallized base material for metallized capacitors and a process for its production in which a vacuum-deposited zinc layer being formed on at least one side of a base material composed of film or thin capacitor paper, and a surface protective layer composed of a substance which shows a predetermined vapor pressure at a predetermined temperature being provided thereon in a predetermined thickness to thereby improve the humidity resistance of the vacuum-deposited zinc layer.