Platinum Metals Rev., 1985, 29, (2), 91
NEW PATENTS: April 1985
METALS AND ALLOYS
Ruthenium Alloy
tokyo shibaura denki k.k. U.S. Patent 4,464,208
An amorphous alloy for a magnetic head contains, in specified proportions, Ru, Co, Fe, Si, B, and at least one of Ti, V, Cr, Mn, Ni, Zr, Nb, Mo, Hf, Ta and W.
Permanent Magnet Alloy
research institute of electric & magnetic alloys U.S. Patent 4,465,526
An easily workable alloy for permanent magnets of high coercive force has a crystalline structure with a fine grain dispersion of alpha phase and gamma phase in a matrix. It contains 19.5−41 at.% Pd, 0.1−27.5 at.% Ag, remainder Fe.
Platinum Group Metals in Hydrogen Storage Materials
ELECTROCHEMISTRY
Semiconductor Electrode
fujitsu ltd. European Appl. 127,281
An electrode has a three layer structure consisting of a contact layer (such as Pt silicide), an intermediate refractory layer and a surface layer (of Pt, Au, etc.).
Mixed Cyanide Functional Electrode
k.k. daini seikosha U.S. Patent 4,451,348
A functional electrode for use as an electrochromic display electrode or as a catalytic electrode for O2 or Cl2 production consists of a conductor coated with a film of ZM[M′(CN)6] or M4[M′(CN)6]3 where Z is a Group IA metal, M is trivalent Fe, Ru or Os and M′ is the divalent form of the same metal.
Platinum Group Metal-Coated Cathode
occidental chemical corp. U.S. Patent 4,456,518
A low H overvoltage Group IA metal halate cell cathode comprises a conductive substrate, an intermediate protective layer such as an intermetallic compound of Ti with a platinum group metal and an overcoating of a mixture of a major portion of Pt and a minor proportion of Rh, Pd, Ir or Os.
Reduced Platinum Oxide Electrocatalyst
general electric co. U.S. Patent 4,457,223
An apparatus for electrolytic production of halogens has a catalytic electrode which includes partially reduced oxides of at least one of Pt, Ir, Ru, Pd and Os and their alloys (and optionally graphite) heated in the presence of O2 to stabilise the reduced oxides.
Polarity Reversing Electrodes
ionics inc. U.S. Patent 4,461,693
The electrodes of a polarity reversing electrodialysis membrane stack are coated, plated or clad with Pt, Ir or Rh or their oxides.
Electrolytic Electrode
permelec electrode ltd. U.S. Patent 4,471,006
A platinum group metal-base metal oxide catalytic coating, for instance consisting of Ru, Ir and Ti oxides, has greater durability when it is applied to a valve metal body carrying an intermediate coating of Ti and/or Sn oxide plus Ta and/or Nb oxide.
Electrolysis Cathodes
permelec electrode ltd. U.S. Patent 4,473,454
Cathodes of improved corrosion resistance, for use in the electrolysis of acid solutions, consist of a valve metal substrate spray coated with a material containing at least 10% of W or WC which is then impregnated with a mixture of cathode-active material and an acid-resistant fluorinated resin. The cathode-active material is a platinum group metal and/or their alloys, mixtures or oxides.
ELECTRODEPOSITION AND SURFACE COATINGS
Solderable Palladium-Nickel Coatings
e. i. du pont de nemours & co. U.S. Patent 4,463,060
A permanently solderable Pd-Ni electroplated coating formed on an electrically conductive surface has a first alloy layer of 46−82 at.% Pd and 18−54 at.% Ni, covered by a continuous second layer of 96−100at.% Pd and 0−4at.% Ni, up to 20Å thick.
Noble Metal Coated Molybdenum
licentia patent-verwaltungs-g.m.b.h. U.S. Patent 4,464,441
A Mo disc suitable for use as a semiconductor is about 0.5 to several mm thick and is coated, via an intermediate 0.5–10 μ m thick layer of Cr, with a 0.02 μ m thick layer of a noble metal such as Pt, Pd, Rh, Ru, Au or Ag.
Palladium Electroplating
a. t. & t. bell laboratories U.S. Patent 4,468,296
In a high-speed Pd electroplating process, at least part of the Pd is added to the bath as an ammine hydroxide complex such as [Pd(NH3)2OH]n(OH)n.
Plating Activator Coating for Non-Conductors
okuno chemical industry co. ltd. U.S. Patent 4,469,714
Normal Sn-Pd salt activation of non-conducting surfaces for subsequent chemical plating is replaced by the application of an activator coating containing an organic binder, a refractory oxide filler and 0.5−20% Pd powder catalyst. One example shows a coating containing 30% epoxy resin plus curing agent, 66% Al2O3 and 1% Pd black.
High-Temperature Coatings
LABORATORY APPARATUS AND TECHNIQUE
Strain Sensor
tokyo electric co. ltd. British Appl. 2,142,776A
A strain sensor has a first conductive layer which constitutes a bridge circuit by coupling a plurality of strain gauge resistors and a new second thinner conductive layer of chemically stable metal such as Pt.
Iridium Crucibles
w. c. heraeus g.m.b.h. British Appl. 2,142,935A
Seamless Ir crucibles are made by cold isostatically compacting Ir powder on a mandrel, sintering the blank in stages at successively higher temperatures (while screening the blank from the heating element using Ir sheet or plate), then isostatically hot compacting the sintered blank.
Gas Detecting Apparatus
new cosmos electric co. ltd. European Appl. 120,605
In a gas detector of improved design a semiconductor is placed in close contact with a metallic heating element which may be a film of Pt or Pt alloy formed in a zigzag pattern on an insulating base.
Sensor for Hydrogen Determination
orbisphere corp. European Appl. 124,818
An electroanalytical sensor has two electrodes separated by an electrolyte and a membrane permeable to H2 but not electrolyte. The anodic H sensing electrode has a surface of polished Pt metal, such as pure Pt polished to mirror brightness.
Titration End Point Detection
mitsubishi kasei k.k.k. European Appl. 125,693
A pair of Pt wire electrodes are used in a constant DC pulse device for detecting titration end points.
Oxygen Partial Pressure in Gases
karl dungs g.m.b.h. & co. European Appl. 126,246
A Pd/Pd oxide probe is used in measuring an O2 partial pressure. The probe may be reversibly oxidised in given conditions of temperature and O2 partial pressure and this causes a change in its electrical resistance.
Gas Sensor
city technology ltd. European Appl. 126,623
H2 and CO may be separately measured, without interference from the other gas, by using porous sensing and counter Pt electrodes.
Hydrocarbon Gas Sensor
siemens a.g. European Appl. 131,731
A thin film sensor for hydrocarbon gas impurity detection and measurement is based on a semiconducting W oxide activated with a platinum group metal, such as Pt itself.
Thick Film Oxygen Sensor
HETEROGENEOUS CATALYSIS
Hydrocarbon Conversion Catalyst
research association for residual oil processing British Appl. 2,138,313A
A hydrocarbon conversion catalyst, particularly suitable for the catalytic cracking of heavy oils containing 0.5ppm or more of heavy metal, consists of 3−40% of a crystalline aluminosilicate zeolite, which may be partially ion exchanged with a lanthanide, Pt or Pd and 60−97% of an alumina-magnesia matrix having a magnesia content of 2−50%.
Carboxylic Acid or Anhydride Production
bp chemicals ltd. British Appl. 2,140,004A
A carboxylic acid or anhydride is prepared by reacting, at elevated temperature and superatmospheric pressure, an olefin with CO and a carboxylic acid in the liquid phase and in the presence of a supported Group VIII metal (preferably Rh) catalyst.
Acetic Acid, Acetaldehyde and Ethanol Production
agency of industrial science & technology British Appl. 2,142,012A
Acetic acid, acetaldehyde and ethanol are produced by reacting CO with H2 in the presence of a catalyst combination of Rh, Ir and Li.
Barium Stabilised Lead Tolerant Catalyst
johnson matthey p.l.c. British Appl. 2,142,253A
A process for making Pb tolerant motor vehicle exhaust purification catalysts, consisting of a platinum group metal catalyst supported on Al2O3 is described. The Al2O3 is impregnated with Ba moiety and fired at 400°C or above before subsequent impregnation with the metal catalyst moiety followed by a second firing at 400°C or above.
Air Purification
teledyne industries inc. British Appl. 2,142,325A
A catalyst consisting of a Pd(II) salt and a Cu(II) salt on a support is used to remove H2S and/or HCN, present in low concentrations from air, preferably at −20°C to 85°C.
Hydrocarbon Cracking Catalyst
chevron research co. British Appl. 2,142,551A
A catalyst composition for use in the fluid catalytic cracking of S-containing hydrocarbons includes an improved oxidation promoter for converting SO2 to SO3. It consists of Pd or one of its compounds, together with at least one of Pt, Os, Ir, Re and Rh as metal or compound.
Vapour Phase Ester Hydrogenation
british petroleum co. p.l.c. European Appl. 123,517
Alcohols are obtained when carboxylic esters are hydrogenated in the presence of a Rh, Ru or Ni catalyst supported on C with a Group IA, IIA, lanthanide or actinide promoter. In one example methanol is produced from ethyl acetate using a mixture of 8.9% Ru and 13.3% K on graphitised C.
Supported Platinum Group Phosphides
exxon research & engineering co. U.S. Patent 4,454,246
Highly dispersed platinum group metal phosphide crystallites, especially Pt phosphide, supported on C, Al2O3, SiO2, SiO2-Al2O3, zeolite, kieselguhr, vermiculite or a Group IVB or VB transition metal refractory oxide, are useful as catalysts for the selective hydrogenation of liquid hydrocarbons or as fuel cell electrodes.
Hydrogen Oxidation Catalyst
cjb developments ltd. and universal matthey products ltd. U.S. Patent 4,459,270
H2 present in moist air is oxidised over a catalyst consisting of an Al2O3/Sn oxide support impregnated with 0.25−2.5% each of Pt and Pd.
Liquid Phase Hydrogenation
johnson matthey p.l.c. U.S. Patent 4,464,482
A supported interstitial catalyst system suitable for trickle feed three phase reactions (such as the hydrogenation of crotonaldehyde or butyraldehyde) preferably has a noble metal catalyst component, such as a Pd or Ru catalyst, supported on a novel three dimensional wire interstitial support.
Three Component Hydrocarbon Reforming Catalyst
standard oil co. (indiana) U.S. Patent 4,469,812
Hydrocarbon reforming is catalysed in the presence of up to 80ppm S by a mixture of three different components, a platinum group metal, a Group VIII base metal and Ga, all separately placed on their own acidic oxide carriers.
Palladium-Loaded Nickel Mica Catalyst
shell oil co. U.S. Patent 4,469,813
A highly active and selective hydroisomerisation catalyst is prepared by heating a Ni synthetic mica montmorillonite with a hydroxy-aluminium chloride and then loading the pillared product with Pd.
Rhodium Synthesis Catalyst
HOMOGENEOUS CATALYSIS
Vehicle Seat
metzeler kautschuk g.m.b.h. British Appl. 2,137,492A
A plastics-covered vehicle seat has a textile covering to the inside of which is applied a layer of a flame-resistant polysiloxane which includes Pt.
Ethylene Glycol and Methanol Production
texaco development corp. British Appl. 2,143,229A
Low molecular weight oxygenated compounds, and particularly ethylene glycol and methanol, are prepared in good yield by contacting a mixture of CO and H2 with a catalyst system comprising a Rh-containing compound, an organic ligand and a sulphonium salt, preferably dissolved in a suitable solvent, at an elevated temperature and pressure.
Catalysed Silicone Rubber Photocuring
minnesota mng. & mfg. co. European Appl. 122,008
The curing of silicone rubber by u.v. radiation instead of heat may also be accelerated by Pt catalysts having a group which may be displaced by irradiation. An aryl Pt diene, such as diphenyl platinum cyclooctadiene, is preferred.
Carboxylic Acid and/or Ester Production
shell international research mij.b.v. European Appl. 124,160
Acids and/or esters are produced by reacting an alcohol with CO in the presence of a homogeneous Pd-containing catalyst, an I and/or Br source and a N compound containing a =N−CX− group (where X is O or S). Thus acetic acid may be produced in the presence of Pd acetate, CH3I and N-methyl pyrrolidone.
Platinum Hydroformylation Catalyst
sun tech inc. European Appl. 125,055
A new catalyst for olefin hydroformylation consists of a zerovalent Pt complex of a phosphine, arsine, etc., mixed with a Group IVB halide. Thus propylene may be hydroformylated by Pt(PPh3)4 and SnCl4.
Rhodium Complex in a Catalyst System
c. d. f. chimie specialites European Appl. 127,501
A catalyst system for the hydroformylation of olefins to aldehydes consists of H(CO)Rh(PPh3)3, PPh3, Co2(CO)8 and a conjugated diene derivative such as 2-ethyl-hex-2-enal.
Urethane Production Catalyst
bayer a.g. European Appl. 129,759
A new catalyst system for the production of urethanes from nitro compounds and hydroxyl compounds consists of (a) at least one noble metal or metal compound, (b) a combination of at least one Fe or Cu oxide or hydroxide with a chloride and (c) at least one organic base. A typical catalyst contains Pd chloride, Fe oxide, ferrous chloride and aniline.
Carboxylic Ester Production
british petroleum co. p.l.c. European Appl. 132,144
Carboxylic esters may be obtained from CO, a metal alkoxy and hydrocarbon halide in the presence of a Rh, Ir or Co catalyst. In one example ethyl phenylacetate is obtained from benzyl bromide, Al ethoxy and CO in the presence of hexadiene Rh chloride dimer.
Alcohol Production from Olefins and Synthesis Gas
standard oil co. (ohio) U.S. Patent 4,456,694
Olefins, CO and H2 are catalytically reacted to produce alcohols in a single step reaction using a catalyst of formula MaRhOx where M is Fe, Zn, Ir, Ru, Nb, Cr, Mn and/or Pt, a is 0.001–10 and x is >0 but less than the number required for full oxidation of the other elements.
Photocatalysts for Amine Production
pennwalt corp. U.S. Patent 4,459,191
A process for making amines by reacting NH3 or a primary or secondary amine with olefins under the action of u.v. light may be catalysed, for example, by RuCl2(PPh3)3 or RhCl(PPh3)3.
Hydrogen Peroxide Production
halcon sd group inc. U.S. Patent 4,462,978
H2O2 is produced from CO, O2 and H2O at −78 to +150°C in the presence of an organic solvent which is a carbonyl compound or nitrile. The catalyst is a platinum group metal such as Pd chloride, Ru trichloride, Rh chloride hydrate, Pt chloride or graphite supporting Pt, Pd or Ru.
ABS Polymer Hydrogenation
johnson matthey p.l.c. U.S. Patent 4,469,849
ABS polymers are hydrogenated in emulsion by contacting the copolymer with H2 and a catalyst dissolved in a solvent. The catalyst is RhCl(PPh3)3, [(PPh3)2Rh(CoD)]+[BF4]−, RhH(CO)(PPh3)3 or RhH(CO)(PPh3)2. The solvent is immiscible in the liquid forming the emulsion and also acts as a swelling agent for the copolymer increasing accessibility of the catalyst to the double bonds. Once the reaction is completed the two layers, one containing the catalyst and the other the polymer, are easily separated.
Linear Alcohols from Olefins
texaco inc. U.S. Patent 4,469,895
A new catalyst for the production of alcohols from olefins (such as nonanols from octene) consists of a Ru compound and an amine promoter dispersed in a low melting quaternary phosphonium salt.
Dimerisation Catalyst
FUEL CELLS
High Pressure Fuel Cell
prutec ltd. European Appl. 124,275
A high pressure cell is made with electrodes formed as thin films deposited on thin film porous membranes. Typically an electrode is formed by a layer of Pt 200−1000Å thick.
Fuel Cell Electrodes
electrochemische energieconversie n.v. European Appl. 126,511
The porous catalyst layer on an electrode is made from a binder mixture of 3–30 parts mouldable polymeric binder, 50–94 parts C particles and 3–47 parts hard hydrophobic polymer particles. In an example the C particles contain 5% Pt.
Negative Hydrogen Electrode
r.c.a. corp. U.S. Patent 4,460,660
An electrode suitable for use in a Ni-H fuel cell is based on a support structure carrying an alloy consisting of equal quantities of Pd and Ru (to 1 or 2%).
Fuel Cell
CHEMICAL TECHNOLOGY
GLASS TECHNOLOGY
Bushing Tip Preparation
p.p.g. industries inc. U.S. Patent 4,461,191
A method of supplying tips for a glass fibre forming bushing is provided which involves mating the tips to a hole in a bushing plate, applying pressure to the tip sidewalls against the plate to firmly seal them followed by a high temperature treatment to form a homogeneous metal bond. The bushings are typically made of Pt-Rh alloys.
ELECTRICAL AND ELECTRONIC ENGINEERING
Radioactive Krypton Fixation
deutsche gesellschaft fur wiederaufarbeitung von kernbrennstoffen m.b.h. British Appl. 2,142,466A
In fixing radioactive Kr by sputtering embedding metal, so as to deposit it on a suitable substrate in the presence of a Kr plasma, the sputtering electrode which forms the embedding metal comprises a radioactive metal, such as Pd, Ru or Rh.
Recording Element
eastman kodak co. European Appl. 120,167
An electrically activatable recording element for forming a non-Ag positive image consists of an electrically conductive support on which is deposited an electrically activatable layer of Pd(NH3)4Cl2 dispersed in a butylacrylate-sodium-2-acrylamido-2-methylpropane sulphonate copolymer.
Connector Using a Shape Memory Alloy
hitachi ltd. European Appl. 123,376
A connector has thin sheets of shape memory alloy located on a substrate surface and placed over holes in the substrate. A pin is inserted in the hole, penetrating the sheets, at a temperature where the sheets are easily deformed. The temperature is changed so that sheets regain their shape and create a good electrical connection. The alloy may be a Pt or Ag alloy, among others.
Screen Printable Resistor Paste
n.v. philips’ gloeilampenfabrieken European Appl. 124,948
A paste for producing printed resistors consists of a mixture of Pb2RhxRu2−xO7−y, where x is up to 0.95 and y is up to 0.5, a glass or other binder, a temporary binder and a solvent. The use of a borosilicate glass, for example, in the resistor enables the T.C.R. to be held at −10 to + 10 × 10−6/°C.
Print Head
ing. c. olivetti & co. s.p.a. European Appl. 129,330
A specified ink jet print head incorporates an Al2O3 base plate on which is deposited a thick film strip of conductive noble metal, preferably Pt.
Diesel Glow Plug
bendix corp. European Appl. 129,676
A glow plug is made from a hollow cylindrical metal shell with a protruding heater member. The member has a non-conductive cylindrical substrate coated with a surface heating film made of platinum group metal or its alloy, such as Pt. The new construction reduces the exposure of the film to high temperatures.
Electrochromic Display Device
citizen watch co. ltd. U.S. Patent 4,451,498
An anodic electrochromic layer is formed on a transparent electrode by ion plating Ir, Rh or Ni on the electrode to form an oxide film.
Semiconductor Devices
texas instruments inc. U.S. Patent 4,455,738
A metal deposited on a prepared Si substrate and converted to the metal silicide (in a method for fabrication of a MESFET device) is preferably Pt.
Semiconductor Strain Gauge
gulton industries inc. U.S. Patent 4,462,018
A semiconductor transducer having integral compensation resistors includes Pt alloy resistors formed on a SiO2 layer and Au conductive lines interconnecting the resistors.
Glass Frits for Ruthenium Dioxide Resistors
corning glass works U.S. Patent 4,464,421
Thick film RuO2-based resistors (T.C.R.<100 ppm) are made by mixing RuO2 powder with a glass frit containing in mol%, 32−39% PbO, 44−47% B2O3, 14−17% SiO2, and an effective amount up to 5% of WO3 or MoO3. The heat treatment of the frit is intended to crystallise PbWO4 or PbMoO3 in situ.
Sparking Plug
nippondenso co. ltd. and toyota jidosha kogyo k.k. U.S. Patent 4,465,952
In a sparking plug of more economical design only the tips of the electrodes are made from a noble metal which may be Pt, Pd, Ir or Au.
Thin Film Capacitor Electrode
MEDICAL USES
Palladium Dental Alloy
degussa a.g. European Appl. 124,750
Casting alloys for bridges, crowns, plates, etc., contain 65−85% Pd, 0−10% Au and/or 0−5% Pt, 0.1−10% Sn, 1−10% Ga, 1−12% Cu and 0.05−1.5% Ru and/or 0.05−0.7% Re.
Cochlear Implant System
australian department of science & technology European Appl. 124,930
Multiple Pt ring electrodes are used in a silastic carrier to be implanted in the cochlea of the ear.
Sensing Device
diamond shamrock chemicals corp. European Appl. 125,807
A transcutaneous blood CO2 and pH sensor has a Pd/Pd oxide junction as an active electrode and a Ag/Ag halide reference electrode applied to a nonconducting substrate and covered with a dielectric and a polymeric membrane.
Medical Electrode
medtronic inc. European Appl. 126,981
A low-polarisation, low-threshold electrode particularly suitable for cardiac pacing is Pt coated.
Magnetic Orthodontic Appliances
medical magnetics inc. European Appl. 127,710
PtCo, SmCo and other similar magnetic materials are used in integrated oral magnetic osteogenic and orthodontic appliances.
Diaminocyclohexane Platinum Complexes
research corp. European Appl. 130,482
New complexes for tumour treatment are 1:1 diaminocyclohexane Pt(II) complexes containing two anions of a monocarboxylic acid or sulphonic acid or one anion of a dicarboxylic acid, for example a bisprolinate or bis-isethionate or a monofuran dicarboxylate.
Dental Alloy
jeneric industries inc. U.S. Patent 4,451,639
An alloy for fusion to porcelain in dental restoration contains 35−85% Pd, 0−12% Cu, 5−15% Ga, 0−50% Au, 0−13% Co, 0.1−0.5% Ru and/or Re, up to 5% Al and up to 0.5% Zn. A typical alloy contains about 78.6% Pd, 10% Cu, 9% Ga, 2% Au, 0.1% Al, 0.1% Zn and 0.2% Ru and/or Re.