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Platinum Metals Rev., 1989, 33, (3), 149

NEW PATENTS: July 1989

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Metals And Alloys

Intermetallic Compound for Jewellery

s. steinemann European Appl. 284,699A

An intermetallic compound for use in jewellery production has the formula AB or AB2 in which A is Pt, Pd, Au, Fe, Co, Ni or a mixture of these with up to 15at.% being replaceable by Cu, and B is Al, Ga, Si or a mixture of these. Due to the grain size of less than 50μ m the compound has a certain ductility and fracture resistance, and is chemically stable in air and aqueous electrolytes.

Castable Palladium Alloy

elephant edelmetaal European Appl. 289,097A

A castable Pd alloy contains 20−50wt.% Pd, 20−50wt.% Ag and 20−45wt.% In, having a preferred Pd:In atomic ratio of 1.2 to 2.1. The alloy is castable, free from Au and has a desirable yellow colour, and is used in the manufacture of dental restorations, jewellery and ornaments.

ELECTROCHEMISTRY

Cathode for Sodium Chloride Electrolysis

permelec electrode European Appl. 298,055A

A cathode has a base with a Ni surface, and a single coating layer of (a) a platinum group metal and/or a platinum group metal (hydr)oxide, preferably Pt or Ru oxide, and (b) 30−70 mol% of Ce and/or Ce (hydr)oxide. The cathode is used in electrolysis of aqueous NaCl by an ion exchange membrane method, retains a greatly reduced H2 overpotential for an extended period, and has high resistance to electrolyte impurities.

Cathode Material for Electrolysis

kamioka kogyo k.k. Japanese Appl. 63/230,894

A cathode is prepared by applying an aqueous solution of metal, for example 0.15 mol/l Pd nitrate solution, to the porous surface of a C or graphite electrode material, firing, and if required reducing the metal oxide to metal. Optionally the coating and firing steps can be repeated. The method is used to provide an electrode which enables electrolysis at a lower electrolytic voltage.

Oxygen Generating Electrode with Iridium Oxide Layer

tdk corp. Japanese Appl. 63/235,493

An electrode consists of an electroconductive substrate with a base-coating layer containing Ir and Ta oxides (50−90mol% Ir and 10−50mol% Ta), and an Ir oxide layer containing 0.05−3 mg/cm3 Ir. The electrode is used as an O2 generating electrode in electrolysis under current densities as high as 100 A/dm2, and also has improved corrosion resistance.

Electrolytic Electrode with Lead Dioxide Coating

sasakura kikai seis. Japanese Appl. 63/238,293

An electrode consists of a laminate of Pt-coated Ti and untreated Ti, the surface of the Pt being selectively coated with electrodeposited PbO2. The electrode is used for electrolysis of H2O, using a solid polymer electrolyte membrane to produce concentrated O3 on the anode.

Photooxidation Catalyst for Cyanide Removal from Waste Water

agency of ind. sci. tech. Japanese Appl. 63/248,443

A catalyst for photooxidation consists of a porous glass membrane of specified porosity carrying TiO2 and a platinum group metal in its pores. Soluble platinum group metal compounds used in the preparation include H2PtCl6, RhCl3, OsCl3, or RuCl3. The catalyst is used for removing cyanide, dichromate and organic compounds from waste H2O, allowing photooxidation to proceed at a high rate.

Palladium Catalyst for Electrolysis Anodes

kamioka kogyo k.k. Japanese Appl. 63/262,491

Anodes for electrolysis are manufactured by applying fine-grained metal oxide catalyst particles to the porous surface of a C or graphite electrode. Typically, Pd nitrate solution is coated on a graphite board, dried at 90°C, fired at 350°C, and then the process is repeated. The anode formed allows electrolysis at low electrolytic voltage.

Alkaline Earth Metal Ruthenate Electrode Coating

techn. univ. dresden East German Patent 258,031

Electrodes for use in electrolysis cells have an electrocatalytic layer containing alkaline earth metal ruthenate, MRuO3, where M is an alkaline earth metal such as Sr, and the Ru loading is 0.5−5 mg/cm2. The coating can be applied in a one or two layer process with a glass-enamel layer, is high-temperature resistant, and has a low precious metal content which gives 40−50% savings compared with prior art electrodes.

Electrolysis Electrode with Increased Stability

busse-machukas v.b. Russian Patent 1,401,072

An electrode consists of a porous metal substrate which has been sand blasted, degreased and etched, with a coating layer applied by electrolysis containing oxides of Ir, Ru and Ti, at an Ir:Ru molar ratio of 0.75−3:1 and 50−75% Ti oxides. The electrode has increased stability, and is used in the production of Cl2, soda, chlorates and hypochlorites by electrolysing aqueous alkaline chloride solutions.

ELECTRODEPOSITION AND SURFACE COATINGS

Palladium Electroplating Bath

amer. chem. & refin. U.S. Patent 4,778,574

An aqueous bath for Pd electrodeposition contains 0.01−0.25 M Pd ion, 0.15−1.5 M soluble electrolyte, and 0.35−2.1 M amine complexing agent consisting of aliphatic and alicyclic amines in molar ratio 0.5−1.5:1. The plating baths produce a sound, ductile Pd deposit, do not liberate free NH3, and are effective over a range of current densities and at low temperatures to produce matte or bright deposits.

Electrodeposition of Rhodium

univ. of hong kong U.S. Patent 4,789,437

Electrodeposition of Rh is achieved using a pulse current, at 10−55°C, in an electrolyte containing 1−20 g/l Rh sulphate and 25−200 ml/l H2SO4 (95−98%). The anode is Pt or Ti plated with Pt or Rh, and the substrate is Au, Ag, Ni, brass, and so on. Rh sheet or foil of thickness 10−200μ m is produced, especially for contact point relays, and the product is crack free and has long life.

Electroless Plating Ceramic Substrates

mitsubishi denki k.k. Japanese Appl. 63/256,588

Electroless plating of a ceramic substrate involves applying a paste layer containing reaction-catalysing Pd ions, heat treating at 200−1200°C in a reducing atmosphere, and then electroless plating. The method is used to apply electroless plated coatings having good adherence and uniformity, on a ceramic substrate.

Stable Ruthenium Plating Solution

nippon mining k.k. Japanese Appl. 63/259,095

A stable Ru plating solution is provided by adding sulphamic acid to Ru sulphate to control the Ru valency. Generation of low valence Ru is avoided, and stable valency is achieved during anodisation or cathodic reduction. In an example Ru plating was effected using a current density of 5 A/dm2, a Pt-coated Ti anode, a Au-plated cathode, and a bath having 5 g/l of Ru sulphate and 100 g/l sulphamic acid.

APPARATUS AND TECHNIQUE

Electrode for Quantitative Determination of NADH

cambridge life sci. European Appl. 289,344A

Quantitative determination of NADH (1,4-dihydronicotinamide adenine dinucleotide) in solution involves measuring the current resulting from NADH oxidation at an electrode surface. The electrode has a layer of activated C or graphite particles with preadsorbed finely divided noble metals such as Pt, Pd or their oxides. The system is stable, reproducible, gives rapid response and can monitor NADH concentrations at relatively low potentials.

Depositing Metal Particles on a Marker for Specific Binding Assays

janssen pharmaceut. n.v. European Appl. 293,947A

A physical developer consisting of metal ions of Pt, Pd, Au, Ag or Tl, excess complexant, and a reducing agent, is used to deposit metal particles on a marker which catalyses metal ion reduction. The method is used in specific binding assays, for example in the determination of haptens, antigens, antibodies or nucleic acid. The complexant allows enough metal ions for growth of metal particles on the marker, while avoiding undesirable side effects.

Flow Cell with Electrical Noise Suppression

beckman instruments inc. World Appl. 88/8,973A

An ion selective electrode flow cell has at least two fluid conduits, the first of which contains a conductive member consisting of a Pt, Rh or Au wire which is connected to ground. The cell is used for measuring the ionic activity of fluids, and has reduced susceptibility to noise entering the cell via the various fluid flow conduits and other externally induced noise.

Radiation Detectors and Sources

colorado state univ. U.S. Patent 4,782,377

Electromagnetic radiation sources and detectors consist of a thin film of semiconducting metal silicide grown or deposited on a Si substrate, where the metal is one of Ir, Fe, Mn, Cr, Re, and so on. Uses include i.r. detector applications such as terrestrial imaging from space, missile detection and ranging, or in combination with fibre optic systems. An integrated systems capability offers increased speed, ruggedness and reliability.

Helium Gas Chromatograph Sensor

mark products inc. U.S. Patent 4,787,239

A wand held He gas chromatograph sensor has a detector with two identical Pt coils, one in an occluded chamber and the other in an isolated chamber. The coils are motion compensated, so that the only differential in electrical resistance across the bridge circuit is due to He. The sensor is used to detect underground leaks, and enables rapid repeated measurement without needing a prolonged warm up interval.

Discharge Electrode Material Containing Ruthenium

toho kinzoku k.k. Japanese Appl. 63/216,943

A discharge electrode material with excellent resistance to heat and oxidation contains 40−98wt.% Ru and 60−2wt.% Y. It is used for cutting metals in an oxidising atmosphere such as air or O2, for example in air plasma cutting, plasma spraying and heat/oxidation resistant electrodes, showing about 2–3 times the resistance to consumption of a Zr and Hf material.

Thick-Film Type Gas Sensor Element

ngk spark plug k.k. Japanese Appl. 63/231,255

A thick-film type gas sensor element is made by forming a porous thick film of gas responsive material on a ceramic substrate supporting Pt electrodes, impregnating with a Pt solution, and heat treating at 60−180°C in a H2 gas furnace to form conductive particles at the thick-film electrode interface, by separation of Pt. Interfacial fracture by differences in thermal expansion is prevented to improve durability.

Platinum Counter Electrode for Gas Sensor

osaka gas k.k. Japanese Appl. 63/233,358

A gas sensor has a ceramic insulating base, a counter electrode formed on this base which is a conductor with not less than 30wt.% Pt, and a gas sensing member consisting of a metallic oxide semiconductor thin film obtained by printing and thermally decomposing a paste. A gas sensor with high sensitivity and selectivity to a specific reducing gas (such as isobutane) can be obtained without using the sensitiser and catalyst layer.

Accurate Conductivity Measuring Cell

nippon genshiryoku jigyo Japanese Appl. 63/243,743

A conductivity measuring cell for a nuclear power plant consists of a stainless steel pressure resistant vessel, containing electrodes coated with an inert metal such as Pt or Au. The interval between electrode layers does not change due to heat of sample solution, so the cell fixed quantity can remain constant regardless of temperature, and there is no precipitation of the electrolyte ion, enabling measurements of high accuracy.

Platinum Catalyst for Impurity Analysis in Aluminium

nippon light metal k.k. Japanese Appl. 63/259,463

A small quantity of impurity in high purity Al is analysed by reacting with ethyl bromide in the presence of a Pt catalyst and bromide, distilling, and using the residue as a secondary sample for analysis. The Pt catalyst forms a battery with the Al, and accelerates reaction with ethyl bromide and dissolution of Al. Every element except Si and Ga can be detemined, and data of high accuracy can be obtained.

Platinum Anode for Combustion Control Sensor

dodensei muki kagob Japanese Appl. 63/261,150

A sensor is prepared by forming an anode mainly composed of Pt on the surface of an O2− ion electroconductive solid electrolyte, forming a perovskite composite oxide cathode on the other surface of the solid electrolyte and forming a gas diffusion layer of MgO on the cathode surface. A sensor having good output and stability can be obtained.

Spiral Spacer as Heater for Oxygen Sensor

matsushita elec. ind. k.k. Japanese Appl. 63/265,161

An O2 sensor includes a spiral spacer consisting of at least one of Pt, Ru oxide with heat-proof fine particles, Ni, and Ag-Pd printing films. The spacer surrounds one of the electrode films formed on both surfaces of a solid electrolyte plate having O2− ion conductivity. The spiral spacer acts as a heater and as part of a spiral diffusion hole, so that the heater can be formed simultaneously with the hole.

Inorganic Catalyst to Improve Hydrogen Peroxide Determination

meidensha elec. mfg. k.k. Japanese Appl. 63/271,141

Determination of H2O2 is used for analysis of glucose or cholesterol in body samples, and involves addition of a reagent such as luminol to the sample followed by chemiluminescent determination of the luminescence generated. An inorganic catalyst of Pt or Pd is added to the reagent to decompose H2O2 not involved with the reaction, which would otherwise affect the calibration curve. Sensitivity and accuracy can be improved.

Contact Combustion Type Carbon Monoxide Gas Sensor

osaka gas k.k. Japanese Appls. 63/271,150-51

A contact combustion type CO gas sensor includes either (a) a Pt or Rh/Al2O3 catalyst, or (b) a Rh catalyst in the detecting element, prepared from a paste of 0.1−5wt.% Rh/Al2O3 applied to a Pt wire coil, and a Pd or Mn oxide catalyst in the comparing element. The gas sensor has high sensitivity, selectively detects CO gas, and is used at high temperature with stability over time. Mis-operation caused by break of balance of the sensor output is prevented.

Methane Gas Sensor

fuji electric mfg. k.k. Japanese Appl. 63/275,942

A gas sensor with high sensitivity to CH4 includes a Rh and Sn oxide fine particle film used as the gas sensitive material, and Pt electrodes for measuring the resistance. The gas sensitive material has improved electrical resistance and is obtained by dipping an Al2O3 base with a Sn oxide fine particle film into 1wt.% aqueous Rh chloride solution, drying, and heating at 600°C for 3 hours.

Oxygen Sensor with Thin Film Electrode

hitachi k.k. Japanese Appl. 63/282,648

An O2 sensor for determining O2 concentration in a gas is formed by connecting an electrode lead wire with electrode leading parts on a thin film electrode of Pt, Pd, Rh, Ir, Au or Ni, formed on the surface of a stabilised ZrO2 ceramic electrolyte. Fused metallising metal solder on the electrode leading parts joins the thin film electrode to the electrode lead wire with tough binding and improved reliability.

Specific Uric Acid Determination

meidensha elec. mfg. k.k. Japanese Appl. 63/282,657

Determination of uric acid in a body sample involves decomposing H2O2 already present in the sample using a Pt, Pd, Mn oxide or Co oxide catalyst, selectively oxidising uric acid in the presence of uricase, measuring the H2O2 generated, and obtaining the amount of uric acid present from a calibration curve. Using this method uric acid can be determined with high sensitivity, accuracy, and specificity.

Platinum or Palladium Catalyst Used in Glucose Determination

meidensha elec. mfg. k.k. Japanese Appl. 63/291,597

Glucose is determined in a living body sample such as urine, blood, or lymph fluid by treating with anion-exchange resin, decomposing H2O2 using a catalyst of Pt, Pd, Co oxide or Mn oxide, treating with glucose oxidase to decompose glucose and form H2O2, and determining the H2O2 and hence the amount of glucose present. Selective determination, with high sensitivity and accuracy can be achieved, without interference from metabolic products in the sample.

Ozone Sensor for Continuous Operation

anseros k. nonnenmac German Appl. 3,711,071

A sensor measures O3 concentration by change in resistivity of a semiconductor when it reacts chemically with O3 in the presence of a catalyst. The catalyst metals are Pt, Pd, Rh, Ru, and others, and the sensor material is ZnO or oxides of Pd, Rh, and others. The sensor is easy to manufacture and is suitable for continuous operation, for example in environmental monitoring of O3 in gases or liquids.

Oxygen Sensor Element Containing Platinum Group Metals

ngk insulators k.k. German Appl. 3,813,930

The electrode structure of an O2 measurement sensor element is made up of a porous layer at least 3μ m thick, containing mainly an O2− ion conducting solid electrolyte, and at least 2 platinum group metals with specified amounts of Rh and total platinum group metals. The element measures the O2 content of exhaust gas to give an accurate air to fuel ratio, even when the exhaust contains unburnt components such as NOx.

Halogen Leakage Detector

veb hochvak dresden East German Patent 258,468

A halogen leak detecting apparatus has a Pt anode wound in a spiral on a ceramic tube, arranged concentrically inside a tubular cathode. The ceramic tube is heated to 900°C to realise the Rice effect, with a buzzer warning when the Pt anode emits alkali ions in the presence of halogen vapours. The apparatus only needs a small battery, can operate away from a mains supply, and can be used to detect leaks in portable refrigeration plant.

Preparing Iridium Solutions for Titration with Ferrocene

krasy univ. Russian Patent 1,394,100

Solutions containing Ir4+ are prepared for titration more efficiently by evaporating the sample to dryness in the presence of NaCl, adding HCl, then H2O2, boiling, cooling, acidifying, and adding dimethylformamide. The prepared solution is titrated potentiometrically with ferrocene, giving increased accuracy and reproducibility, and increased maximum determinable level of Ir4+.

JOINING

Silver Solder for Brazing

tanaka kikinzoku kogyo Japanese Appl. 63/97,394

A Ag solder consists of at least one of 3−27wt.% Pd, 2−18wt.% In and 2−15wt.% Sn, 45−75wt.% Ag, 0.001−0.5wt.% Fe, 0.01−3wt.% P, and balance Cu. The solder is used for brazing electronic parts, ornaments or similar metal articles in a vacuum, H2 atmosphere or similar gas. The solder has good wetting properties and usability, giving a brazed zone with improved surface smoothness and high bonding strength.

Production of a Soldering Iron Tip

v.p. maslov Russian Patent 1,386,398

The tip of a soldering rod consists of a Cu alloy with electrodeposited layers of Ni and Rh. The Rh layer is 3μ m thick and is deposited at a rate of 0.05 μ m/min from an electrolyte containing 2.6 g/l Rh and 50−80 g/l HCl. This method for production of a soldering iron tip gives high stability against molten solder.

HETEROGENEOUS CATALYSIS

Production of Silylated Aromatic Compounds

general electric co. European Appl. 284,873A

A SiO2-supported transition metal complex catalyst containing Pt, Pd or Ni is used for the reaction of a halogenated polysilane with an aromatic acyl halide, and can be readily recycled and regenerated. The products are silylated aromatic compounds having at least one Si atom bonded directly to a ring C atom, and can be hydrolysed to produce valuable intermediates such as bis(siloxane anhydrides).

Nitrogen Oxides Removal from Combustion Effluents

energy environ. res. European Appl. 287,224A

Removal of NOx from combustion effluents from automobile engines, furnaces and turbines involves a decomposition step and a step to reduce the NOx content by mixing with effluent at 250−1425°C, in a reaction zone with excess O2 using a promoter and a Pt, Pd or W catalyst. The process is low cost and NOx levels can be reduced to below 100 ppm, with simultaneous removal of S oxides.

Stereo-Selective Rhodium Hydrogenation Catalyst

nederland org. tno European Appl. 289,061A

A catalyst is prepared by applying Rh carbonyl clusters to a support, preferably SrTiO3, under an inert atmosphere to give 0.5−2.5wt.% Rh, pyrolysing at 100−300°C, and activating with O2 at 0−150°C. Very active catalysts with low Rh content and stereo-selectivity are obtained; used for hydrogenation of unsaturated organic compounds such as alkenes, alkynes and aromatics, under mild conditions.

Unsaturated Glycol Diester Production

mitsubishi kasei co. European Appl. 289,725A

A new method for production of unsaturated glycol diesters involves reaction of O2 with a carboxylic acid and a conjugated diene using a catalyst of Pd and Te supported on activated C of specified porosity. The catalyst has high activity, minimal tendency for deterioration, and is for use on an industrial scale. The product, especially butenediol diester, is used for manufacture of plastics, fibres and solvents.

Car Exhaust Catalyst Able to Remove Hydrogen Sulphide

w.r. grace co. U.S. Patent 4,780,447

A new car exhaust catalyst consists of an Al2O3 support with at least one platinum group metal such as Pt or Rh, up to 10wt.% of Ni and/or Fe oxides as H2S getters, 1−20wt.% CeO2 and 0.5−5wt.% of an alkali metal oxide as promoters, and a stabiliser of 1−10wt.% La2O3. The catalyst removes H2S from car exhausts while still being able to meet the requirements for CO, NOx and hydrocarbon emission levels.

Automotive Catalyst with Two Phases Containing Platinum

ford motor co. U.S. Patent 4,782,038

A catalyst for automotive exhaust gas treatment consists of a support with a codeposited first phase of 2−20wt.% CeO2 in atomic scale intimacy with 0.05−0.5wt.% Pt or Pt and Rh, and Al2O3, and a second phase with the platinum group metal, but devoid of CeO2. The catalyst is used for treating internal combustion engine exhaust, having the advantages of CeO2 as a stabiliser without the disadvantages, such as lack of tolerance to Pb poisoning.

Platinum Catalyst for Isomerisation Process

uop inc. U.S. Patent 4,783,575

In an isomerisation process a catalyst consisting of 0.1−0.25wt.% Pt, 2−10wt.% of a chloride component, and Al2O3 is contacted with a feedstream containing 4−6C isomerisable hydrocarbons and at least 2wt.% of cyclic hydrocarbons. The catalyst selectively opens the cyclic hydrocarbon rings, leading to improved catalyst activity, and increased liquid volume yields. The product is a high octane gasoline component.

Microencapsulated Platinum Group Metal Hydrosilation Catalysts

dow corning corp. U.S. Patent 4,784,879

A microencapsulated platinum group metal compound is prepared by depositing a polymer coating around finely divided metal compound particles to at least 50% of the coated particle weight. The products are useful as hydrosilation catalysts for one-part, heat-curable, organosiloxane compositions, giving storage stability of several months, and rapid curing at temperatures above the melting point of the encapsulant.

Surface Impregnated Dehydrogenation Catalyst

uop inc. U.S. Patent 4,786,625

A catalytic composite for hydrocarbon dehydrogenation contains a platinum group metal, a modifier metal selected from Sn, Ge, Re or their mixtures, and optionally other elements, on an Al2O3 support. The platinum group metal is surface impregnated so that its concentration on the outer 100μ m is twice that in the 200 μ m diameter centre core. The catalyst has improved activity, selectivity and stability.

Improved Naphtha Reforming Catalyst

exxon res. & eng. co. U.S. Patent 4,787,969

An improved reforming catalyst consists of 0.05−1wt.% of Pt and Re promoted with 0.01−1wt.% Ir agglomerated to show a crystallinity of 60−100% as measured by X-ray, 0.1−2.5wt.% halogen, and up to 0.2wt.% S, supported on Al2O3. The catalyst is used to improve the octane number of a hydrocarbon naphtha feed by reforming with H2 and has high activity, high S-tolerance, high C5 + liquid volume yield and rapid catalyst regeneration.

Catalytic Composite for Hydrocarbon Conversion

uop inc. U.S. Patent 4,791,087

A catalytic composite for the conversion of hydrocarbons consists of 0.05−1wt.% of uniformly dispersed Pt, 0.1−2wt.% of uniformly dispersed Ge or Pb, 0.05−1wt.% of surface impregnated Rh, Ir, Ru, Co or Ni, and 0.5−1.5wt.% of Cl, on an Al2O3 support. The catalyst is useful for production of high octane gasoline by reforming of naphtha, having improved activity, selectivity and activity stability.

Specific Rhodium Catalyst for Preparation of Oxygen-Containing Compounds

daicel chem. ind. k.k. Japanese Appl. 63/227,531

Oxygen-containing compounds such as acetic acid, acetaldehyde and ethanol are prepared by reacting CO with H2 over a 0.01−15wt.% Rh catalyst. The catalyst is prepared by a specific procedure which includes supporting Rh compound(s) and accelerator compounds of K, Li, Mn or Ir on a carrier, drying and heating under an inert gas atmosphere, and reducing. Selectivity and yield of products are improved by using the catalyst.

Oxidation Catalyst for Catalytic Combustion

tanaka kikinzoku kogyo Japanese Appl. 63/228,250

An oxidation catalyst is prepared by immersing an activated Al2O3 coated support in an aged solution containing 250−450 g/l of Pd(NH3)2(NO2)2 complex in HNO3, and then reducing the impregnated Pd complex. Uniformly and finely dispersed Pd particles can be obtained, providing higher initial activity. In an example the catalyst was used for combustion of natural gas containing 90% CH4, giving a lower ignition temperature of 300°C.

Durable Exhaust Gas Purification Catalyst

nippon shokubai kagaku Japanese Appl. 63/229,145

A catalyst for purifying exhaust gas consists of 5−30wt.% Pt and 1−20wt.% Rh supported on a refractory inorganic oxide of average particle size 0.5−20μ m, and Ce oxide, on a honeycomb support. The catalyst has good durability, even in high temperature oxidising atmospheres.

Oxidation Catalyst with Finely Dispersed Platinum

tanaka kikinzoku kogyo Japanese Appl. 63/236,540

An oxidation catalyst is prepared by immersing an active Al2O3 coated support in a matured solution containing Pt (NH3)2(NO2)2 and 250−450 g/l HNO3, and then reducing the Pt compound. A catalyst with finely dispersed Pt particles is produced; having improved initial activity, and useful for oxidation of hydrocarbon type fuels.

Three-Way Catalyst with Reduced Hydrogen Sulphide Generation

nissan motor k.k. Japanese Appl. 63/236,541

An exhaust gas purification catalyst has a carrier supporting active Al2O3, at least one of Pt, Rh and Pd or its oxide, CeO2 and an oxide of at least one of Ti, Nb, V, Ta and Mn. The weight ratio of the CeO2 and the metal oxide is 3:1−1:3. The catalyst shows good removal of CO, hydrocarbons and NOx, and can lower H2S from the exhaust gas under idling conditions after running for a long time at high speed.

Exhaust Purification Catalysts with Separate Alumina Coatings

nissan motor k.k. Japanese Appls. 63/240,946−47 and 63/240,949

Automobile exhaust purification catalysts consist of a support having two or more different coatings loaded separately. The first coating contains activated Al2O3 and Pt, Pd, Rh or Pd and Rh, and may contain CeO2, while the second coating contains activated Al2O3 with Ni, Fe or Co, or other oxides and optionally Pt, Pd, Rh or Pt and Rh. The catalysts are used to remove NOx, CO and HC from combustion exhaust.

Ruthenium Catalyst for Preparation of Cycloolefins

asahi chemical ind. k.k. Japanese Appls. 63/243,038–39

A hydrogenating catalyst consists of colloidal Ru with average particle size 40−100 Å coated on ZrO2, or 0.1−20wt.% Ru with average particle size 30−200 Å on ZrO2 or HfO2. Partial hydrogenation of monocyclic aromatic hydrocarbons in the presence of the catalyst, Zn compounds, and H2O is used to prepare cycloolefins, especially cyclohexene, in higher yield and selectivity, for use for various chemicals such as polyamides or lysine.

Steam Reforming Catalyst

tokyo gas k.k. Japanese Appl. 63/248,444

Steam reforming and/or partial oxidation of hydrocarbons uses a catalyst prepared by supporting 1−50wt.% Ni and/or Co on Al2O3, MgO or SiO2, firing, supporting a platinum group metal, and reducing. After firing, the Ni and/or Co form, for example, NiAl2O4, NiSiO3 or a solid solution. Steam reforming can continue for a long time without depositing C, at low steam to hydrocarbon ratio, and at low cost using the catalyst.

Palladium Hydropurification Catalyst

mitsubishi chem. ind. k.k. Japanese Appl. 63/251,494

Palladium supported on Al2O3 of radius 0.5−2.5 mm is used as a catalyst for hydropurification of hydrocarbon oil containing 10 ppm or less As, 200 ppm or less S, and 10 ppm or less basic N. The ratio of the Pd penetration distance to the radius of the Al2O3 catalyst support is 0.02–0.4. The process makes further apparatus for removing As in the raw oil unnecessary, and is economical and feasible at relatively low temperatures.

Catalyst with Defined Particle Size Alumina Coating

toyo kogyo k.k. Japanese Appl. 63/256,140

A new catalyst has a characteristic Al2O3 coating on the support, with Al2O3 particles of average diameter 3−5 μ m on the gas inlet side and 30−50 μ m on the gas outlet side, and is loaded with 3.0 g/l Pt and Rh (Pt/Rh=7/3). The catalyst is used for waste gas purification, has reduced heat capacity and is easy to warm, providing improved performance on cold or warming up driving.

Methanol Decomposition Catalyst

mitsubishi gas chem. k.k. Japanese Appl. 63/264,141

A CH3OH decomposition catalyst having higher activity and selectivity consists of a SiO2 support having 0.5−5.0wt.% Pd with Al, Zr or Nd, or with Al and La. The catalyst is used at 150−400°C under 0.01−50 atm to decompose CH3OH and produce H2 and CO2 containing gases, used as raw gas for Cl chemistry or a fuel gas for automobiles or fuel cells.

Improved Production of Hexafluoroacetone

mitsui fluorochemical k.k. Japanese Appl. 63/264,541

Hexafluoroacetone is prepared by contacting hexafluoropropene and molecular O2 with a catalyst consisting of 0.3wt.% of noble metal(s) selected from Pt, Pd, Rh, Ir and Ru, on active C. The catalyst gives improved yield and selectivity, and the product is used as a modifier of ethylene-tetrafluoroethylene copolymers, as a solvent, or as an intermediate for other chemicals.

High Temperature Resistant Oxidising Catalyst

mitsubishi heavy ind. k.k. Japanese Appls. 63/267,803–5

An oxidising catalyst consists of a base material with the front stage coated with Pd on Al2O3 or Pd on compound oxides such as BaO-Al2O3, SrO-Al2O3 and CaO-Al2O3; an optional medium stage coated with Pt or Pt-Rh on Al2O3; and the back stage having one of the compound oxides, optionally with Pt or Pt-Rh oxides, with base metals and/or La-containing compound oxides. The catalyst has high heat resistance even above 1000°C, and is used to oxidise CO, H2 and hydrocarbons at low temperatures.

Purification of Styrene

mitsubishi chem. ind. k.k. Japanese Appl. 63/277,639

Purification of styrene involves (a) controlling the moisture content to 2000 ppm wt. or less and (b) selective hydrogenation of highly unsaturated impurities such as phenylacetylene or diolefins over a supported Pt metal(s) catalyst at 10−100°C. Using this method, impurities which would inhibit polymerisation can be reduced without loss of styrene, which gives a good quality polymer.

Noble Metal Catalyst on Metal Support

tanaka kikinzoku kogyo Japanese Appl. 63/291,642

A Pt and/or Pd catalyst loaded on a metal support is prepared by treating a Zn or Al support with HNO3 to form an oxide film, forming a thin film of a reducible noble metal compound such as dinitroammine-Pt and/or -Pd on it, and reducing in H2. A noble metal catalyst with higher activity and good mechanical strength is prepared at a lower temperature, for example 200°C compared to 500°C conventionally.

Impregnation Solutions for Automobile Exhaust Catalysts

hoechst a.g. German Appl. 3,711,280

Automobile exhaust gas catalysts are impregnated in series with a solution containing Pt and Rh salts and also a V salt, present at 0.2–10 times the sum of the concentrations of the two noble metals. Alternatively separate solutions containing Pt and V salts, and Rh and V salts can be used. Lowering of the noble metal salt concentrations in the solution is prevented.

Ruthenium Catalyst for Preparation of Aromatics

veb chem. leipzig-gr. East German Patents 256,513–14

A catalyst for use in the preparation of benzene, toluene and xylenes contains more than 50wt.% of an H-pentasil zeolite, a binder, and 0.05−1% of Ru or Ru (at least 30at.%) with Pt, Rh, Ir, Os or Re. The aromatics are prepared either by cyclisation of ethane at 650−980K, or by conversion of CH4 to 2C hydrocarbons, then converting this gas stream over the catalyst at 650−1050K. The catalysts have long life, and give high selectivity and space/time yields.

Stable Flameless Combustion Element

w. brandenburg East German Patents 258,183–84

A combustion element has layers of glass fibre fabric, asbestos paper or flat ceramic materials, with at least the top layer infiltrated or sprayed with solutions of (a) Pt, Pd, or Re; or (b) Pt or Pd and hexavalent Cr, which are then reduced. The element is used as a heating pad for catalytic flameless combustion in camping stoves, battery heaters and so on, and has high stability and reliability, long catalyst service life and contains a reduced amount of precious metals.

Modified Zeolite Catalyst for Hydroisomerisation

as belo phys-org. ch. Russian Patent 1,015,582

Hydroisomerisation of light gasoline fractions is effected at 350−390°C and 25–30 atm using a Y-type zeolite catalyst in decationised or rare earth form, modified with 0.5−1.0wt.% Pd and 0.17−0.5wt.% Mn. The zeolite is contained in an amorphous aluminosilicate matrix at 5−30wt.%. The method gives 96.5−97.8% yield of high octane gasoline with octane number 77.6–80.4, from light oil fractions.

Purification of Gaseous Effluents Containing Organochlorine Compounds

nairit polymer prod. Russian Patent 1,398,893

Removal of organochlorine compounds from gaseous effluents involves passing through a layer of milled zeolite, and then through a layer of Al-Pd catalyst containing 0.05wt.% Pd. The process is conducted at 450−500°C, and is used for purification of effluents from chloroprene and chloroprene rubbers production, giving an increased degree of purification (90.7−100%).

HOMOGENEOUS CATALYSIS

Aromatic Carboxylic Acids Preparation

nihon noyaku k.k. European Appl. 283,194A

A new preparation of aromatic and heterocyclic carboxylic acids involves reaction of the corresponding organic chloride with CO, an organic base and a Pd-phosphine compound catalyst, at 150−300°C. The compounds are produced in good yields for manufacture of pharmaceuticals and agrochemicals.

Adipic Acid Diester Preparation by Two-Stage Carbonylation

shell int. res. mij. b.v. European Appl. 284,170A

Adipic acid diesters are prepared by (a) contacting 1,3-butadiene with CO and an OH-containing compound in the presence of a Pd compound combined with a polydentate ligand containing P, As or Sb as catalyst, (b) isolating the product, and (c) reacting with CO in the presence of a second carbonylation catalyst. This new preparation is for commercially important dimethyl adipate and overcomes problems of very high pressures.

Palladium Catalyst for Ibuprofen Production

hoechst celanese co. European Appl. 284,310A

Ibuprofen (2-(4-isobutylphenyl)propionic acid) is prepared by reacting 1-(4-isobutylphenyl)ethanol with CO, in the presence of a Pd catalyst and specified amounts of H+ and halide ions. The catalyst is a Pd compound complexed with at least one monodentate phosphine ligand, having a P:Pd mol ratio of at least 2:1. The specified amounts of ions improve yields of ibuprofen, which is a well known anti-inflammatory agent.

Preparation of Fluorine-Substituted Alicyclic Diols

daikin kogyo k.k. European Appl. 286,991A

A novel process for preparation of F-substituted alicyclic diols involves hydrogenation of a F-substituted aromatic diol in the presence of a Pt, Pd, Ru, Raney Ni or especially Rh catalyst. The product is obtained in high yield in a short time, with few byproducts, and is useful as a starting material for various resins; used as adhesives, packing materials for electronic devices, and in paints.

Palladium Catalyst for Bisphenol Hydrogenation

montedison spa. European Appl. 290,239A

A process for the hydrogenation of bisphenols involves reaction with H2 at 80−160°C and an H2 pressure of 50−150 atm, catalysed by 1−20wt.% Pd on activated C of surface area 400−900 m2/g. Reaction selectivity is above 99wt.% with a trans isomer product content of above 55wt.%, giving a product useful for preparation of thermosetting polyester resins.

Preparation of Carbamate Compounds

shell int. res. mij. b.v. European Appl. 296,686A

Carbamate compounds are prepared by reaction of an organic hydroxyl compound with CO and an organic nitrogenous compound in the presence of a catalyst system of Pd and/or a Pd compound and a H2O soluble sulphonated bipyridine or phenanthroline compound. The catalyst components can be recycled, and the products are obtained in high yield with high selectivity, for use as starting materials for agrochemicals, dyes, or organic isocyanates.

Novel Catalyst Precursors Containing Iridium

univ. of oregon World Appl. 88/6,489A

Novel catalyst precursors soluble in organic solvents contain Ir and also include an olefinic ligand or dioxygen, and other metals. Activation with H2 gives catalysts for use in hydrogenation reactions such as hydrogenation of olefins. The catalysts are stable and are readily recovered from hydrogenation products by binding to an anion exchange resin.

Preparation of Dialkylpiperazines

texaco inc. U.S. Patent 4,774,336

N,N′-dialkylpiperazines can be prepared by reaction of ethylene glycol with a primary amine in the presence of a homogeneous Ru trichloride tributylphosphine catalyst system and a solvent, at 150−250°C and 100−300 psi. Certain products can be prepared in good yields under mild conditions, and most are useful as acid scavengers and urethane catalysts.

Rhodium or Ruthenium Carbonylation Catalysts

eastman kodak co. U.S. Patents 4,778,917–18

Coproduction of an aromatic carboxylic acid ester and an alkyl iodide is effected by carbonylating an aromatic iodide in the presence of an ether and a Rh or Ru catalyst. The process uses less severe conditions than previously, gives a product with low H2O content and hence low acid formation, and allows ready recovery of the halide. The esters produced may be used for polymer precursors, and the alkyl iodides as a source of I2.

Platinum Catalyst Inhibitor

dow corning corp. U.S. Patent 4,785,066

Polyorganosiloxane compositions are curable by a Pt catalysed hydrosilation reaction. A new Pt catalyst inhibitor is claimed to extend the working time of the compositions at 25°C, without decreasing the cure rate at temperatures of at least 100°C. Inhibitor and polymer refractive indices can be matched.

Production of Rhodium Oxymetallate Complexes

minnesota mining mfg. co. U.S. Patent 4,788,308

Rhodium oxymetallate complexes are produced from a carbonyl complex cation and a Keggin anion by a multistep reaction. The products are useful as catalysts, for hydroformylation of olefins to aldehydes, oxidation of aldehydes to carboxylic acids.

Rhodium Carbonylation Catalyst

bp chemicals ltd. U.S. Patent 4,792,620

Carbonylation of alkyl esters and ethers is by reaction with CO at 50−4000°C, in the presence of a solution containing a Rh catalyst, and I2 or an I compound as promoter. The catalyst system is more stable and allows use of lower catalyst concentrations, temperatures, pressures and reaction times.

Rhodium Catalyst for Olefin Hydroformylation

mitsubishi chem. ind. k.k. Japanese Appl. 63/208,540

Hydroformylation of olefins involves reaction of the olefin with CO and H2 in a catalyst solution containing Rh and trivalent P compound oxides, and includes a new process in which the product mixture is separated into aldehydes and still residue by distillation. This new process greatly improves olefin conversion, aldehyde yield and catalytic activity.

Ester Production under Neutral Conditions

sumitomo chem. ind. k.k. Japanese Appl. 63/216,844

An ester is produced by reaction of a nitrile, an alcohol compound and H2O using a Ru or Rh catalyst, in molar ratio 1:0.9:1−3:0.03, respectively. Reaction is at 140−180°C, with catalysts such as RuH2(P(C6H5)3)4 or RuCl2.nH2O. Esters can be produced under neutral conditions without decomposing functional groups such as benzyloxy.

Noble Metal Complex Catalysts for Selective Reactions

nippon petrochem. k.k. Japanese Appls. 63/233,945 and 63/233,949

Reactions of (1-arylethenyl)vinylbenzene(s) with (a) H2 and CO or (b) CO and H2O or a low alcohol are effected using noble metal complexes of Pt, Pd, Rh, Ir or Ru as catalysts. Reaction (a) allows selective hydroformylation of the vinyl group to give α -((1-arylethenyl)phenyl)propionaldehyde(s), while (b) gives selective hydroesterification to α -((1-arylethenyl)phenyl)propionic acid.

Rhodium Compound for Production of Substituted Polyacetylenes

mitsubishi chem. ind. k.k. Japanese Appl. 63/275,613

Substituted polyacetylenes are produced by polymerising substituted acetylene compounds in the presence of a compound containing a Group VIII metal, especially Rh, an organophosphorus ligand, other ligands, and anions. Polyacetylene is useful for producing a film or conductive polymer.

FUEL CELLS

Active Catalysts for Methanol Fuel Cell Electrodes

yanmar diesel engine European Appl. 292,184A

High activity powder catalysts containing highly concentrated platinum group metals are formed by selective dissolution in HF of Ni, Co and other metals from an amorphous alloy containing one or more of Pt, Pd, Rh, Ir and Ru, Ni and/or Co, and one or more of Ti, Zr, Nb and Ta. The catalysts are used in the manufacture of highly active electrodes for a fuel cell.

Cathode for Fuel Cells

eltech. syst. corp. European Appl. 292,431A

A gas diffusion electrode consists of a porous gas diffusion layer and an electrolyte porous active layer having 10−65wt.% of a halogenated polymer, and 35−90wt.% of 1−25μ m C particles containing a platinum group metal or oxide as catalyst. The electrode is used as an O2 reduction cathode in fuel cells, and can operate at high current densities with acceptable durability.

Platinum-Ruthenium Anode Catalyst

fuji electric mfg. k.k. Japanese Appl. 63/213,260

An anode catalyst for a fuel battery is produced by adhering Ru hydroxide to a supported Pt catalyst, and heat treating in an inert gas atmosphere so that the Ru hydroxide is reduced to metal and simultaneously alloyed. Using this method Ru is efficiently adhered on the Pt particles, and a Pt-Ru catalyst with fine metal particles, good dispersivity and improved CO poison resistance can be produced.

Platinum-Boron Carbide Catalyst for Fuel Cell Air Electrodes

tanaka kikinzoku kogyo Japanese Appl. 63/256,138

A catalyst for fuel cell air electrodes consists of 3−20wt.% Pt and B4C loaded on an electroconductive C support, and is produced by mixing boric acid solution with a Pt/C catalyst and heating in an inert atmosphere at 600−1200°C to form and deposit the B4C on the support. The catalyst maintains a higher activity over a long time, with less increase in Pt particle size compared to conventional catalysts.

Platinum Electrode Catalyst for Fuel Cells

fuji electric mfg. k.k. Japanese Appl. 63/287,554

A Pt catalyst is prepared by contacting a Pt salt with the carrier subjected to a hydrophilic treatment, making alkaline, adding colloid flocculation inhibitor, gradually raising the temperature and adding a reducing agent having an aldehyde group. The catalyst has ultrafine crystallites, large specific surface area and high dispersion. The method can be used for mass production of electrode catalysts for fuel cells.

CHEMICAL TECHNOLOGY

Platinum Surface for Nozzle Holes of Spinning Nozzle

tanaka kikinzoku kogyo Japanese Appl. 63/227,805

A spinning nozzle is made of stainless steel with the surface of the nozzle holes composed of Pt jointed with electrical insulating material, Pt-Rh alloy or an oxide-dispersion type Pt. When the nozzle is used the surface section is uniformly heated to give crude filaments of C fibre with less thread cutting, non-curling and having stable cross-section and structure.

Metal Coated Carbon Fibre Production

nippon oil k.k. Japanese Appl. 63/275,781

A Pd complex compound able to lose Pd by heating is a complex of a divalent Pd compound with an amio compound such as an aminosilane. The Pd complex is adhered to the surface of the fibre, which is heated and then contacted with a Ni or Co halogenide and alkyl Li to cover the C fibre surface with Ni or Co. The product is used for C fibre reinforced metal complex material.

GLASS TECHNOLOGY

Glass Layer for Microwave Utensils

degussa a.g. European Appl. 294,503A

A glass layer is made from a paste containing a conductive material and an organic binder. The claimed composition of the conductive material is 5−95wt.% Ru oxide, 0−60wt.% Ag, 0−30wt.% Pd and/or PdAg, 0−10 wt.% Rh oxide and/or 0−10 wt.% Bi oxide. The layer combines high absorption with low reflectivity for the microwave energy used.

Corrosion Resistant Palladium Alloys for Use with Molten Glass

compt. lyon-alemand louyo European Appls. 298,822A–23A

New Pd alloys containing at least one addition element selected from Ag, Bi, Cu and In, or 2−20wt.% Sn are formulated to give a corrosion resistance equivalent to that of Pt-10% Rh alloy, while being less expensive to produce. The alloys are used especially in the glass industry for parts contacting molten glass, having acceptable resistance to corrosion by the molten glass.

ELECTRICAL AND ELECTRONIC ENGINEERING

Manufacture of Superconducting Oxide Compositions

massachusetts inst. tech. British Appl. 2,202,528A

A noble metal-metal oxide superconductor may be formed by oxidising a metallic alloy under conditions such that the noble metal component is not oxidised. The noble metal is preferably Pt, Pd, Au or Ag. The alloy can be made in a desired shape or form prior to oxidation, such as wire, ribbon or sheet.

Catalytic Burn-Out of Organic Material from Glass

corning glass works European Appl. 287,231A

Accelerated burn-out of organic substances, particularly from glass or ceramic materials, in a gaseous non-oxidising atmosphere is achieved by incorporating a catalyst consisting of at least one material containing Pt, Pd, Rh, Ir, Os or Ru. This process is useful in the fabrication of microelectronic circuits prepared through thick film technology.

Palladium-Zirconium Getter for Electric Lamp

philips gloeilampen n.v. European Appl. 291,123A

An electric lamp has a vacuum-tight vessel with a light source and a getter consisting of an intermetallic compound of Pd and Zr and/or Y. The getter particle size is mostly <40 μ m with Pd:total metal mol fraction of 0.02−0.1, and with O present in the O:(Zr+Y) mol ratio of 0.05−0.2:1. The getter binds O, H and also H2O at low temperatures such as 150−300°C, and has a higher working rate and capacity.

Porous Metal Cladding for Superconductors

american tel. & teleg. co. European Appl. 291,221A

Porous metal cladding selected from Pt, Pd, Au and Ag is used in metal-clad superconductors, such as ceramic superconductor wires. Preferably the metal cladding is changed from low to high porosity by selective etching. The porous cladding allows atmospheric access to the superconductor during the heating stage of the process, so there is no loss of O during sintering, which may affect superconductivity.

Laser Optical Recording Material

basf a.g. European Appl. 293,741A

A multilayer laser optical recording material has a flat support with a thin recording layer consisting of alternating layers of Au and at least one of Pt, Pd, Rh, Ir, Os, Ru, Ag, Re and Cu. The recording layer has 15−85wt.% Au, average depth 5−300 nm and specified surface granularity. The materials have high sensitivity, low signal to noise ratio, high durability, excellent storage stability and resistance, and can be used for storing and handling information.

Manufacture of Superconducting Inorganic Compounds

imi titanium ltd. European Appl. 293,981A

Inorganic superconductors with high critical temperature are made by electrophoretic deposition or coating of a number of components from solution onto a substrate, followed by heat treatment in an O2 containing atmosphere. The substrate may be Pt coated, Ag coated, Ag or an electrically conducting ceramic. The method is especially useful for the manufacture of superconducting wires and tapes.

Long Life Cathode Impregnated with Barium Osmiate

u.s. sec. of the army U.S. Patent Appl. 7,213,035

A cathode is formed by pressing and sintering a powder mixture of 70wt.% W, 29wt.% Os and 1wt.% Zr hydride activator to form a porous billet, and then impregnating by contacting with molten Ba3Os2O6 by firing in a dry H2 atmosphere at 1600°C for 22 min, and cooling and cleaning away any loose impregnants. A long life, high current density cathode is formed for use in mm and microwave devices.

Magnetic Head for Magnetic Encoder

nippon kogaku k.k. Japanese Appl. 63/222,216

The magnetic head for a magnetic encoder has a nonmagnetic base of Pt, Pd, Rh, Ru, Au, Ag, Cu, Al, and so on, with a non-magnetic insulating layer of A1N, SiC, BP, BeO or diamond formed between the base and the magneto-resistance effect elements. By using the non-magnetic metallic base of high heat conductivity, the temperature is uniform, and measuring accuracy can be improved.

Electroconductive Printing Paste

tamura kaken k.k. Japanese Appl. 63/226,811

An electroconductive printing paste contains a highly electroconductive powder of Pt, Pd, Au, Ag, Ni, Cr or Mo, and so on, a resin binder consisting of a polyimide- and/or polyamideimide-resin precursor, and a solvent. An electroconductive printed pattern with uniform thickness can be produced.

Reliable Conductive Paste

toyo ink mfg. k.k. Japanese Appl. 63/228,525

An electron rays-hardening type conductive paste contains a silane compound with an electron rays reactive group, a compound with one or more electron rays reactive groups, and 5−90wt.% of a conductive fine powder of Pt, Pd, Au, Ag, carbon black or graphite. The paste is used in the making of printed wiring circuits and hybrid thick film circuits, and has good reliability for conductivity and bonding.

Monocrystalline Thin Film of Whisther Alloy

hitachi k.k. Japanese Appl. 63/233,097

A monocrystalline thin film is a Whisther alloy film with a magneto-optic effect, consisting of at least one single crystal layer formed on a crystalline base plate. The alloy has the formula XYZ where X is Pt, Pd, Ni, Co and/or Cu, Y is Mn, and Z is Sb, Sn and/or Bi. Use of the monocrystalline base plate makes monocrystallisation of the Whisther alloy possible, enabling magnetisation of the thin films for magnetic and magneto-optic elements.

Fine Copper Wire for Use in Semiconductors

furukawa electric co. Japanese Appl. 63/238,233

A Cu fine wire contains 0.2−2000 ppm of one or more of 0.1−1000 ppm Pd, 0.1−1000 ppm In, 0.1−1000 ppm Nb, 0.1−2.5 ppm Cr and balance Cu. The wire is used particularly in making semiconductors, enabling good bonding to the Al of the electrode pads.

Corrosion Resistant Permanent Magnet

sumitomo spec. metal k.k. Japanese Appl. 63/238,240

A sintered permanent magnet has a metal coating consisting of at least one of Pt, Pd, Au and Ag, and at least one of Ni, Cu, Sn and Co. When left to stand for 500 hours under conditions of 80°C and 90% relative humidity the magnet showed 10% or less degradation of its magnetic characteristics compared with the initial values.

Preparation of a Multicoloured Surface Member

seiko denshi kogyo k.k. Japanese Appl. 63/240,503

A multicoloured surface member is prepared by forming several electrically conductive layers onto a base, and repeatedly electrocoating colouring layers selectively onto the electrically conductive layer, which includes conductive particles of at least one of Pt, Pd, Rh, Au, Ag, Cu, Ni, and so on. The uniformity of the electrocoating film can be improved, giving an improved surface member used for multicolouring of displaying devices.

Corrosion Resistant Permanent Magnet

sumitomo spec. metal k.k. Japanese Appls. 63/254,702 and 63/255,376

A sintered permanent magnet containing 65−80at.% Fe, 2−30at.% B and 10−30at.% other elements (R) has at least one of Pt, Pd, Au and/or Ag on the surface applied either by vapour deposition or adsorption of a precious metal colloid, followed by electroless plating of at least one of Ni, Cu, Sn and Co. An Fe-B-R system permanent magnet with good corrosion resistance and stable magnetic characteristics is obtained, with less degradation when left for a long time at 80°C in 90% relative humidity.

Corrosion Resistant Alloy for Thin Film Magnetic Elements

tohoku metal ind. ltd. Japanese Appl. 63/255,339

An Fe-Si-Ga alloy for soft magnetic thin films consists of 0.05−3wt.% of a platinum group metal, 4−12wt.% Si, 6−18wt.% Ga, 0.001−2wt.% of at least one rare earth element, and balance Fe. The alloy has good corrosion resistance, high mechanical strength, high permeability and is used for thin film magnetic elements such as thin film magnetic heads.

Surface Metallised Polymer

nisshin spinning k.k. Japanese Appl. 63/274,778

A polymer is surface metallised, for example with Pd, by dissolving the polymer and an organic metal complex − such as benzonitrile-Pd complex – in a solvent, forming the polymer to a desired form, and dipping into reducing solution. The method is used to make a polymer for plane heating elements, circuit boards, capacitors or reflectors, simply, in a short time, and at low cost.

Connecting Metal for Firing to Oxide Superconductors

nippon hybrid techn. Japanese Appl. 63/290,230

An oxide superconductor is connected to metal or other material by contacting with a connecting metal coating, and firing. The connecting metal consists of 30wt.% or less of Pt, Pd and/or Au, with balance Ag and impurities, and has a superconductivity transition temperature higher than liquid N temperature. Using the connecting material, multi-core or single wire, various sensors, or magnetic shielding material can be obtained.

Platinum-Iron-Niobium Permanent Magnet Alloy

res. inst. elec. magn. alloy German Appl. 3,810,678

A permanent magnet consists of an alloy of 33−47at.% Pt, 48−66.9at.% Fe, 0.1−10at.% Nb and <0.5at.% impurities, and has an incomplete γ -1 phase with face-centred tetragonal crystal structure. Manufacture involves high and medium temperature annealing, and gives a material suitable for intricate shapes with a much higher maximum energy-product. Use of Nb ensures improved reproducibility of magnetic properties.

Reliable Electrical Contact

veb bergbau funk a. East German Patent 258,736

A multilayer electrical contact has a contact layer of Pd and Au and an intermediate layer of Ni which has a second layer of thickness 1 to 4μ m and a hardness of 1.3 to 2.5 times the hardness of the Pd contact layer. The contact is formed galvanically and has high reliability, long life, and provides a saving in precious metal.

Palladium Paste for Ceramic Capacitors

viteb. as. belo hard Russian Patent 1,379,296

Preparation of ceramic capacitors prior to attaching the electrodes involves metal plating by applying a Pd containing paste to the non-fired surface, then firing in air for 4−6 hours at 1240−1420°C, followed by an additional reducing annealing step in N2 atmosphere. The method is used in electronics and radio-techniques, and permits reduced use of expensive Ag.

TEMPERATURE MEASUREMENT

Temperature Sensor with Improved Response

smiths ind. p.l.c. British Appl. 2,204,696A

A temperature sensor has a silk-screened Pt resistance track protected by an insulating glaze, on the outer surface of a ceramic tube, which also has a Pt band around one end. The track is exposed to air flowing over both surfaces of the tube, and the change in track resistance is used to measure air temperature. The sensor has improved response and can be used to detect the airstream outside an aircraft.

Resistor for Platinum Resistance Thermometers

danfoss a/s. British Appl. 2,206,741A

An electrical resistor used in Pt resistance thermometers is of laminar form and consists of a substrate carrying a metal film with separating zones spacing parts of the film from one another. The film defines a resistance track with connection zones at its ends. The method gives secure mechanical fixing of the connectors, and less danger of mechanical damage to the connections.

MEDICAL USES

Production of Substituted Oestradiene-3-one for Contraceptive Formulations

schering a.g. European Appl. 285,548A

An ethynyl-hydroxy-methyl substituted 4,15-oestradiene-3-one is produced by Pd catalysed conversion of the 17-substituted hydroxyoestratetraene to the 17-one, followed by reduction steps, oxidation, ethynylation, and splitting the ether. The Pd catalyst dehydrogenation step introduces the 15-double bond under relatively mild conditions, giving high yields of the product which is a powerful gestagen, used in contraception.

Radioactive Rhodium Complexes with Polyamine Chelants

dow chemical co. European Appl. 296,522A

New functionalised polyamine chelants are used to form complexes with radioactive Rh, and are also used for complexing Tc and Re. The complexes formed can be attached to a support, antibody or fragment and used for diagnostic or therapeutic purposes.

New Dihydrobenzofuran Derivative for Medical Use

sato seiyaku k.k. Japanese Appl. 63/196,575

A dihydrobenzofuran derivative and its base-addition salts are new, and its preparation is by a hydrogenation reaction in the presence of a reducing catalyst for catalytic hydrogenation, such as Pd-C. The new derivative is used for treating infectious diseases, having shown effectiveness against streptococcus mutans, bacteroides frailis, and so on.

Versatile Dental Cap Foil

h. truetsch German Appl. 3,711,486

A dental cap foil may be made of a 45-88% Au alloy containing one or more of Pt, Pd, As, Sn or In with traces of Ir, Zn and Ga. The foil is used for producing crown frames for metal-ceramic crowns and has at least one pair of diametrically opposed wings joined at the centre, which overlap when covering a tooth. The foil is easy to handle and can be adapted to different sized teeth.

Polychemotherapy with Supplementary cis-Platinum

a. med. medic radiolo. Russian Patent 1,264,431

Polychemotherapy includes administering cis-platinum dropwise and intra-arterially prior to endolymphatic administration of one dose of BCG vaccine and cessation of some radiation. The frequency of tumour regression is increased from 50% to 75% in the treatment of locally disseminating cancer of the urinary bladder in radiology and oncology.

The New Patents abstracts have been prepared from material published by Derwent Publications Limited.

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