Abstract: A method of separating rhodium from platinum and/or palladium includes; chloridizing a raw material including rhodium and at least platinum and/or palladium in chlorine atmosphere and obtaining a soluble salt of platinum and/or palladium; water-leaching chloridized material and dissolving platinum and/or palladium into a solution; filtering the solution; and leaving rhodium in a filtered residue of the solution.

Abstract: The invention provides an apparatus for effectively removing ruthenium when ruthenium is removed from a solution containing platinum group metal by oxidation distillation. The invention provides an apparatus for selectively removing ruthenium from a solution containing ruthenium and other platinum group metal by adding an oxidizer to the solution to convert ruthenium into ruthenium tetroxide, wherein air is sucked into a reaction tank by reducing pressure within the reaction tank, and at least one outlet of the air is arranged in the apparatus such that the lowermost part thereof is located at the height of 5-20 m from the bottom of the reaction tank, whereby the solution within the reaction tank can be effectively stirred without ruthenium tetroxide, which has large specific gravity, being concentrated at the bottom of the reaction tank.

Abstract: A method of separating rhodium from platinum and/or palladium includes; chloridizing a raw material including rhodium and at least platinum and/or palladium in chlorine atmosphere and obtaining a soluble salt of platinum and/or palladium; water-leaching chloridized material and dissolving platinum and/or palladium into a solution; filtering the solution; and leaving rhodium in a filtered residue of the solution.

Abstract: The invention provides an apparatus for effectively removing ruthenium when ruthenium is removed from a solution containing platinum group metal by oxidation distillation. The invention provides an apparatus for selectively removing ruthenium from a solution containing ruthenium and other platinum group metal by adding an oxidizer to the solution to convert ruthenium into ruthenium tetroxide, wherein air is sucked into a reaction tank by reducing pressure within the reaction tank, and at least one outlet of the air is arranged in the apparatus such that the lowermost part thereof is located at the height of 5-20 m from the bottom of the reaction tank, whereby the solution within the reaction tank can be effectively stirred without ruthenium tetroxide, which has large specific gravity, being concentrated at the bottom of the reaction tank.

Abstract: Ammonium hexachlororuthenate is produced by adding ammonium chloride to a hydrochloric acid solution containing ruthenium. The ammonium hexachlororuthenate is baked to obtain the ruthenium powder. When the moisture content of the ammonium hexachlororuthenate is high, the baked product is so hard sintered product that its pulverization is not easy. In accordance with the present invention, the following steps are carried out. Hydrochloric acid solution containing ruthenium is held at a temperature of 80 to 95° C. for three hours or longer. The ammonium chloride is then added to the hydrochloric acid solution which is stirred by a stirring mill at the rotation of 200 revolutions per minute or more. The hydrochloric acid solution is held at a temperature of from 85 to 95° C. for 1 hour while being stirred at 200 rpm. The resultant precipitate of ammonium hexachlororuthenate is filtered. The inventive crystals of precipitated ammonium hexachlororuthenate has 10 mass % or less of moisture content.

Abstract: The invention provides an apparatus for effectively removing ruthenium when ruthenium is removed from a solution containing platinum group metal by oxidation distillation. The invention provides an apparatus for selectively removing ruthenium from a solution containing ruthenium and other platinum group metal by adding an oxidizer to the solution to convert ruthenium into ruthenium tetroxide, wherein air is sucked into a reaction tank by reducing pressure within the reaction tank, and at least one outlet of the air is arranged in the apparatus such that the lowermost part thereof is located at the height of 5-20 m from the bottom of the reaction tank, whereby the solution within the reaction tank can be effectively stirred without ruthenium tetroxide, which has large specific gravity, being concentrated at the bottom of the reaction tank.

Abstract: Ammonium hexachlororuthenate is produced by adding ammonium chloride to a hydrochloric acid solution containing ruthenium. The ammonium hexachlororuthenate is baked to obtain the ruthenium powder. When the moisture content of the ammonium hexachlororuthenate is high, the baked product is so hard sintered product that its pulverization is not easy. In accordance with the present invention, the following steps are carried out. Hydrochloric acid solution containing ruthenium is held at a temperature of 80 to 95° C. for three hours or longer. The ammonium chloride is then added to the hydrochloric acid solution which is stirred by a stirring mill at the rotation of 200 revolutions per minute or more. The hydrochloric acid solution is held at a temperature of from 85 to 95° C. for 1 hour while being stirred at 200 rpm. The resultant precipitate of ammonium hexachlororuthenate is filtered. The inventive crystals of precipitated ammonium hexachlororuthenate has 10 mass % or less of moisture content.

Abstract: For a three-layer flexible board, there is provided a copper alloy foil that requires no roughening processing, that has good adhesion with an adhesive containing an epoxy resin, that can be laminated to form a copper-clad laminate, that has a low surface roughness, and that has high conductivity and strength. The copper alloy of the foil contains at least one of 0.01-2.0 weight percent Cr and 0.01-1.0 weight percent Zr or contains 1.0-4.8 weight percent Ni and 0.2-1.4 weight percent Si. Good adhesion of the copper alloy foil to a resin substrate with an adhesive containing an epoxy resin is obtained by setting the thickness of the anticorrosive coating to less than 3 nm; the surface roughness of the copper alloy foil is below 2 ?m expressed as ten-point average surface roughness (Rz); and, without roughening processing, the 180° C. peel strength, after adhesion of the copper alloy foil to the board film by means of an adhesive containing an epoxy resin, is greater than 8.0 N/cm.

Abstract: For a two-layer printed wiring board including a polyimide substrate produced with varnish containing polyamic acid as the raw material for the polyimide and a copper alloy foil laminated with the polyimide substrate, there is provided, for the copper alloy foil, a copper alloy containing, in addition to copper and unavoidable impurities, either (1) 0.02 to 1.0 weight percent Ag and/or 0.01 to 0.5 weight percent In or (2) alloy composition (1) plus a total of 0.005 to 2.5 weight percent of at least one of the additional elements Al, Be, Co, Fe, Mg, Mn, Ni, P, Pb, Si, Ti and Zn, or (3) 0.001 to 0.5 weight percent Sn or (4) alloy composition (3) plus a total of 0.005 to 2.5 weight percent of at least one of the additional elements of alloy composition (2) and each of (1), (2), (3) and (4) preferably having a heat resistance of at least 300° C.

Abstract: A copper-alloy foil used for a laminate sheet achieves 5.0N/cm or more of 180° peeling strength when thermally fusion-bonded with liquid crystal polymer. The copper-alloy foil contains one or more of from 0.01 to 2.0% of Cr and from 0.01 to 1.0% of Zr. An oxide layer and occasionally a rust-proof film present on the outermost surface is 10 nm or less. The electrical conductivity is 50% IACS.

Abstract: For a three-layer flexible board, there is provided a copper alloy foil that requires no roughening processing, that has good adhesion with an adhesive containing an epoxy resin, that can be laminated to form a copper-clad laminate, that has a low surface roughness, and that has high conductivity and strength. The copper alloy of the foil contains at least one of 0.01-2.0 weight percent Cr and 0.01-1.0 weight percent Zr or contains 1.0-4-8 weight percent Ni and 0.2-1.4 weight percent Si. Good adhesion of the copper alloy foil to a resin substrate with an adhesive containing an epoxy resin is obtained by setting the thickness of the anticorrosive coating to less than 3 nm; the surface roughness of the copper alloy foil is below 2 &mgr;m expressed as ten-point average surface roughness (Rz); and, without roughening processing, the 180° C. peel strength, after adhesion of the copper alloy foil to the board film by means of an adhesive containing an epoxy resin, is greater than 8.0 N/cm.

Abstract: For a three-layer flexible board, there is provided a copper alloy foil that requires no roughening processing, that has good adhesion with an adhesive containing an epoxy resin, that can be laminated to form a copper-clad laminate, that has a low surface roughness, and that has high conductivity and strength. The copper alloy of the foil contains at least one of 0.01-2.0 weight percent Cr and 0.01-1.0 weight percent Zr or contains 1.0-4-8 weight percent Ni and 0.2-1.4 weight percent Si. Good adhesion of the copper alloy foil to a resin substrate with an adhesive containing an epoxy resin is obtained by setting the thickness of the anticorrosive coating to less than 3 nm; the surface roughness of the copper alloy foil is below 2 &mgr;m expressed as ten-point average surface roughness (Rz); and, without roughening processing, the 180° C. peel strength, after adhesion of the copper alloy foil to the board film by means of an adhesive containing an epoxy resin, is greater than 8.0 N/cm.

Abstract: For a two-layer printed wiring board including a polyimide substrate produced with varnish containing polyamic acid as the raw material for the polyimide and a copper alloy foil laminated with the polyimide substrate, there is provided, for the copper alloy foil, a copper alloy containing, in addition to copper and unavoidable impurities, either (1) 0.02 to 1.0 weight percent Ag and/or 0.01 to 0.5 weight percent In or (2) alloy composition (1) plus a total of 0.005 to 2.5 weight percent of at least one of the additional elements Al, Be, Co, Fe, Mg, Mn, Ni, P, Pb, Si, Ti and Zn, or (3) 0.001 to 0.5 weight percent Sn or (4) alloy composition (3) plus a total of 0.005 to 2.5 weight percent of at least one of the additional elements of alloy composition (2) and each of (1), (2), (3) and (4) preferably having a heat resistance of at least 300° C.

Abstract: For a two-layer printed wiring board including a polyimide substrate produced with varnish containing polyamic acid as the raw material for the polyimide and a copper alloy foil laminated with the polyimide substrate, there is provided, as the copper alloy foil, a copper alloy foil having good wettability with the varnish and a low surface roughness that enables direct bonding with polyimide without roughening plating processing of the copper alloy foil. The copper alloy of the foil contains at least one of 0.01-2.0 weight percent Cr and 0.01-1.0 weight percent Zr or contains 1.0-4.8 weight percent Ni and 0.2-1.4 weight percent Si. Good wettability with the varnish is obtained by setting the thickness of anticorrosive coating on the copper alloy foil to less than 5 nm; the surface roughness is less than 2 &mgr;m expressed as ten-point average surface roughness (Rz); and, without roughening and plating processing, the 180° C.

Abstract: A copper-alloy foil used for a laminate sheet achieves 5.0N/cm or more of 180° peeling strength when thermally fusion-bonded with liquid crystal polymer. The copper-alloy foil contains one or more of from 0.01 to 2.0% of Cr and from 0.01 to 1.0% of Zr. An oxide layer and occasionally a rust-proof film present on the outermost surface is 10 nm or less. The electrical conductivity is 50% IACS.

Abstract: A copper alloy foil to be used in a printed board comprising a polyimide substrate is provided. The copper foil is not subjected to roughening plating and has hence fine surface roughness and can be directly bonded with the polyimide substrate. The copper alloy contains (a) one or more of the additive elements of from 0.01 to 2.0% of Cr and from 0.01 to 1.0% of Zr, or (b) from 1.0 to 4.8% of Ni and from 0.2 to 1.4% of Si. The surface roughness in terms of the ten-point average surface-roughness (Rz) is 2 &mgr;m or less, the 180° peeling strength is 8.0 N/cm or more. The alloy (a) has 600 N/mm2 or more of tensile strength, and 50% ICAS or more of electric conductivity. The alloy (b) has 650 N/mm2 or more of tensile strength, and 50% ICAS or more of electric conductivity.

Abstract: A non-magnetic substrate for use in a magnetic head, consists of the basic composition consisting of CoO and NiO or NiO, and (a) from 0.1 to 7% by weight of ZrO.sub.2 and HfO.sub.2 based on 100% of the basic composition, or (b) from 0.1 to 7% by weight of ZrO.sub.2, and from 0.1 to 2% by weight of Al.sub.2 O.sub.3. Cracking of the magnetic-layer structure is prevented.