Abstract: In the resin film forming method for extruding a fused resin from an extruder die to form a resin film, the second resin forming both ends in width direction of the resin film uses a resin greater in extension viscosity than the first resin forming the center in width direction of the resin film. Thereby, even if production conditions such as resin condition and operating conditions change, faults such as neck-in and its resultant thickening at both ends of the resin film can be suppressed. In the production of a laminate by nipping a support and a resin film of a thermoplastic resin by means of a nip roller and a cooling roller while coating the resin film onto the surface of the support, the accompanying air following the rotation of the cooling roller to the nip point is shut off by blowing a gas permeable through the resin film from a gas jet nozzle toward the surface of the cooling roller.

Abstract: A lead-free piezoelectric ceramic material is provided having a large piezoelectric strain constant which exhibits low temperature dependence. The piezoelectric ceramic material includes Ba, Bi, Na, Ti, and O, in the molar ratio of: 0.997≦Bi/Na≦1.003, and Ba/Bi=2x/(a-x) wherein 0.99≦a≦1.01, 0<x<a. The piezoelectric ceramic material may be employed for producing piezoelectric devices such as oscillators, actuators, sensors and filters.

Abstract: Disclosed is a dielectric ceramic material represented by composition formula: (uLi2O—vNa2O)—wSm2O3—xCaO—yTiO2, having a solid solution structure made up of perovskite crystals represented by Ca1−xSm2x/3TiO3, perovskite crystals represented by Li1/2Sm1/2TiO3, and perovskite crystals represented by Na1/2Sm1/2TiO3. Substitution of part of Ti in the composition with at least one of Ga and Al provides a dielectric ceramic material with a particularly increased value of unloaded quality coefficient. The absolute value of the temperature coefficient of resonance frequency is controlled to a small value by adjusting the proportions of Li and Na.

Abstract: A dielectric ceramic composition which comprises a composition represented by xBaO.yNd.sub.2 O.sub.3.zTiO.sub.2 (where 8.5.ltoreq.x.ltoreq.20, 5.ltoreq.y.ltoreq.23, 62.ltoreq.z.ltoreq.85, and x+y+z=100), Y.sub.2 O.sub.3 in an amount not more than 15 wt % of the amount of said composition, and Al.sub.2 O.sub.3 in an amount not more than 2 wt % of the total amount of the principal components BaO, Nd.sub.2 O.sub.3, TiO.sub.2, and Y.sub.2 O.sub.3. And a relative permittivity .epsilon.r of the dielectric ceramic is not less than 59, its dielectric loss (tan .delta.) is 3.times.10.sup.-4 .about.8.times.10.sup.-4 (2.7 GHz), and its temperature coefficient of resonant frequency .tau.f may be -30.about.+10 ppm/.degree.C. This microwave ceramic dielectric will be used for dielectric resonators in the microwave frequency region, microwave IC substrates, and impedance matching of microwave circuits.