Abstract: To provide a composition whereby it is possible to obtain a metal-clad laminate having low relative permittivity and dissipation factor and having adhesion of the composition layer to the metal layer improved, as well as the metal-clad laminate comprising a composition layer made of the composition, and a method for its production. A composition comprising a fluorinated polymer A1 containing units based on a fluoroolefin and units based on a monomer having an adhesive functional group, and an inorganic filler having a specific surface area of less than 5.5 m2/g, wherein the content of the inorganic filler in the solid content of the composition is at least 55 vol % to the entire volume of the solid content of the composition.

Abstract: To provide a substrate with low dielectric loss tangent, relative permittivity, transmission loss and thermal expansion coefficient and excellent in mechanical strength, and a metal laminated substrate using this substrate. A substrate comprising a tetrafluoroethylene polymer and an inorganic filler, wherein the rate of change in dielectric loss tangent at 10 GHz before and after 72 hours of unsaturated pressure cooker test at 120° C. under 85% RH on a 127-?m-thick specimen cut out from the substrate is at most 30%.

Abstract: A method for producing a silicon nitride filter including heat-treating in nitrogen a green body containing from 40 to 90% of metal silicon particles having an average particle diameter of from 1 to 200 ?m and from 10 to 60% of a pore-forming agent, where the total amount of the metal silicon particles and the pore-forming agent is at least 90%, forms a porous product made substantially of silicon nitride.

Abstract: A silicon nitride porous body which is a body having a generally columnar outer shape and at least two through-holes mutually parallel to one another and which has generally perpendicularly oriented columnar crystals on the surface of the through-holes.

Abstract: A method for the production of a silicon nitride filter includes heat treating in nitrogen a green body containing from 40 to 90% of metal silicon particles having an average particle size of from 1 to 200 &mgr;m and from 10 to 60% of a pore forming agent. The green body contains at least 90% of the metal silicon particles and the pore forming agent and forms a porous product. The filter is excellent in heat resistance, corrosion resistance, acid resistance and mechanical strength and suitable for dust arresting or dust removing and is particularly suitable as a filter for particulates. The porosity of the silicon nitride filter is from 40 to 70% and the cumulative pore volume of pores with diameters of at most 1 &mgr;m is from 1 to 15 vol % of the total pore volume.

Abstract: The present invention provides a silicon nitride filter which is a filter excellent in heat resistance, thermal shock resistance, corrosion resistance, acid resistance and mechanical strength and suitable for dust arresting or dust removing, and which is particularly useful as a filer for particulates, and a method for its production.

Abstract: The present invention provides a silicon nitride filter which is a filter excellent in heat resistance, thermal shock resistance, corrosion resistance, acid resistance and mechanical strength and suitable for dust arresting or dust removing, and which is particularly useful as a filer for particulates, and a method for its production.

Abstract: A silicon nitride porous body which is a body having a generally columnar outer shape and at least two through-holes mutually parallel to one another and which has generally perpendicularly oriented columnar crystals on the surface of the through-holes.

Abstract: Stable facsimile communications and reduced deterioration in image quality are achieved, when standard facsimile apparatuses communicate using a communication network composed a subnetwork with relatively good transmission quality such as a wire system and a subnetwork with relatively bad transmission quality such a mobile system subnetwork, both subnetworks being interspersed between the facsimile apparatuses, by inserting a pair of FAX signal converting apparatuses into the communication channel between the facsimile apparatuses for error control responsive to the quality of the channel in use.

Abstract: A radio phone equipment for credit card is adapted to transfer part or a whole of credit card or charge card information read by a card reader as well as a dial number dialed by a key pad to a mobile telecommunication switching office by means of a modem and a transmitter/receiver, and in case of said credit card or charge card being valid, switching, on the basis of a designation on a voice channel transmitted from said mobile telecommunication switching office, or transmitting and receiving frequency to said voice channel to construct a speech channel, and furthermore detecting on-hook of a handset produced upon finishing talking to reset the equipment.

Abstract: A mobile radio unit assures a wide area communication system having a function equal to a tracking exchange function and profitably employing an equipment of the existing exchange as it is. The mobile radio unit stores a secret number to assure a terminating limit service.