Abstract: A laminated sheet suitable for high-frequency welding comprises a vinylidene fluoride resin layer (A), a bonding layer (B) consisting of a blend of vinylidene fluoride resin and a copolymer resin consisting of methyl methacrylate and alkyl ester of acrylate, whose alkyl group has 3-5 carbon atoms, a base-material layer (C) of vinyl chloride resin bonded to the bonding layer (B), and a base-cloth layer (D) bonded to the base-material layer (C). A bonded laminated sheet obtained by bonding two laminated sheets with high-frequency welding and the application of the bonded laminated sheet to tents are also disclosed.

Abstract: Abrasive filaments made of a composition which comprises 95-70 vol.% of a polyvinylidene fluoride resin, whose inherent viscosity (.eta..sub.inh) ranges from 0.9 to 1.4, and 5-30 vol.% of abrasive grains. They are produced by melt-spinning the composition and then stretching the resultant filaments at a draw ratio of 2.5 times-5.5 times within a temperature range of 100-200.degree. C.

Abstract: Abrasive filaments made of a composition which comprises 95-70 vol. % of a polyvinylidene fluoride resin, whose inherent viscosity (.eta..sub.inh) ranges from 0.9 to 1.4, and 5-30 vol. % of abrasive grains. They are produced by melt-spinning the composition and then stretching the resultant filaments at a draw ratio of 2.5 times-5.5 times within a temperature range of 100.degree.-200.degree. C.

Abstract: The dielectric film contains from 40 to 97% by volume of a thermoplastic resin, from 2 to 50% by volume of a ceramic dielectric and from 1 to 25% by volume of carbon black. The composite film contain a base film layer composed of said dielectric film and the dielectric film of the thermoplastic resin provided on at least one surface thereof.

Abstract: A piezoelectric and pyroelectric film made from a resin composition of polymer of vinylidene fluoride, which is characterized by an index of birefringence of larger than 3.times.10.sup.-3 and a ratio of d.sub.31 /d.sub.32 of 0.3 to 3.0, and which may be prepared by further stretching a biaxially stretched film made from the above-mentioned resin composition at a temperature lower than the temperature of the biaxially stretching by more than 20.degree. C. before or at the same time of a treatment for orientation polarization of the film.