WET NONWOVEN FABRIC CONTAINING META-ARAMID AND POLYPHENYLENE SULFIDE AND LAMINATED SHEET OF THE SAME

In order to provide electrical insulating paper and an electrical insulating sheet including the same which exhibit excellent dielectric breakdown strength， excellent hygroscopic dimensional stability and thermal dimensional stability， and excellent tear strength and wear durability， a nonwoven fabric is fabricated wherein the fabric is a wet nonwoven fabric containing a meta-aramid fiber and a polyphenylene sulfide short fiber and a proportion of the polyphenylene sulfide short fiber at least partially fused in the wet nonwoven fabric is 40% or less， and the wet nonwoven fabric has a dielectric breakdown strength of 17 kV/mm or more. This wet nonwoven fabric contains meta-aramid fibers and polyphenylene sulfide short fibers in order to provide an electrical insulation paper which has excellent dielectric breakdown strength， excellent dimensional stability against moisture absorption and excellent thermal dimensional stability， while exhibiting excellent tear strength and excellent wear durability， and an electrical insulation sheet which uses this electrical insulation paper. With respect to this wet nonwoven fabric， the mixing rate of polyphenylene sulfide short fibers that are at least partially fusion bonded is 40% or less; and the dielectric breakdown strength of this wet nonwoven fabric is 17 kV/mm or more.