Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/06—Surface treatment of glass, not in the form of fibres or filaments, by coating with metals
  • C03C17/10—Surface treatment of glass, not in the form of fibres or filaments, by coating with metals by deposition from the liquid phase
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
  • B22F1/05—Metallic powder characterised by the size or surface area of the particles
  • B22F1/054—Nanosized particles
  • B22F1/0545—Dispersions or suspensions of nanosized particles
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/04—Making non-ferrous alloys by powder metallurgy
  • C22C1/0466—Alloys based on noble metals
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
  • H01B1/14—Conductive material dispersed in non-conductive inorganic material
  • H01B1/16—Conductive material dispersed in non-conductive inorganic material the conductive material comprising metals or alloys
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/20—Materials for coating a single layer on glass
  • C03C2217/25—Metals
  • C03C2217/251—Al, Cu, Mg or noble metals
  • C03C2217/254—Noble metals
  • C03C2217/256—Ag
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2218/00—Methods for coating glass
  • C03C2218/10—Deposition methods
  • C03C2218/11—Deposition methods from solutions or suspensions
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1343—Electrodes
  • G02F1/13439—Electrodes characterised by their electrical, optical, physical properties; materials therefor; method of making

Definitions

• composition comprising silver metal particles and a metal salt
• the invention pertains to a composition comprising silver metal particles and an additive, to temperature-resistant electrically-conductive layers, to an active matrix liquid crystalline display (AMLCD) comprising the said layers, and to the use of said composition in the manufacture of silver-containing layers in an article.
• Compositions comprising silver particles with or without other constituents, are well known in the art.
• EP 826,415 a method for preparing a silver sol has been disclosed. These silver sols are used for making a conductive film on a substrate. By spin-coating the sol onto a substrate, such films are made and these are then heated at 150°C.
• EP 276,459 a method for manufacturing cathode-ray tubes was disclosed.
• Antistatic silicon dioxide films were prepared that contained small amounts of (among others) silver.
• a solution or a colloidal solution containing metal particles a cationic or anionic surfactant was added as an additive for improving the stability of the solution, after which an antistatic film was produced by a spraying, dispensing, or dipping method of this material onto a substrate, followed by heating at 200°C for 15 min.
• silver-containing layers particularly layers that contain 80 vol.% or more silver, cannot be heated above 250°C, and preferably not above 200°C without serious appearance of irreversible hillocking/exfoliating and/or creep phenomena. Creep is a process wherein the film deteriorates into a plurality of small sections containing silver and section therein between containing no silver.
• Silver-containing layers (or films) that have undergone exfoliation and/or creep no longer have a low resistivity, and because of the low conductivity have become unsuitable for most of the applications that require a resistivity of less than 6 ⁇ .cm (microOhm.centimeter). Since silver-containing layers are usually made of compositions also comprising organic materials such as organic binder materials or stabilizers, and because only relatively low temperatures (less than 250°C, preferably less than 200°C) can be used for making silver-containing layers with sufficient conductivity, such layers usually contain amounts of organic materials that are not sufficiently removed at those temperatures. Also in further processing steps high temperatures (higher than 250°C) may be necessary.
• fritting a CRT-cone to a screen occurs at 450°C.
• a polymeric binder and frit glass particles can be mixed into a silver paste.
• the presence of the glass particles reduces the conductivity considerable.
• these added particles have sizes in the micron range, such mixed pastes are not longer suitable to make silver-containing layers thinner than 1 ⁇ m.
• Thin layers of well-conducting silver on an insulating surface such as on Corning® 1737 glass, which are used for active matrix liquid crystal displays (AMLCD), or on glass or any other substrate for use in infrared reflective stacks, can be made by using an electroless silver process, but the maximum temperature in the further reaction steps is limited to 250°C. At that temperature Si 3 N deposition takes place, and moreover, the electroless process is commercially not desired anyway since it is a slow non-equilibrium process with a short bath pot life.
• compositions comprising silver metal particles and an additive, which is a silane derivative comprising at least one methyl group and at least one alkoxy group, are very stable and can be applied onto a substrate and heated to temperatures as high as 450°C, usually as high as 700°C, and in many instances even as high as 1000°C.
• the resistivity of silver-containing layers of 200 nm thickness made of these compositions at these high temperatures remained as low as 2.5 to 6 ⁇ .cm, which values are completely comparable with the resistivity of silver-containing layers that are obtained by electroless depositing silver at 250°C, which was found to be 3-4 ⁇ .cm.
• the spin-coated glass plates were cured at 250°C for 30 min, followed by a further heat treatment for 30 min at 350, 450, 500, and 550°C. The results obtained with these silver-containing layers with respect of resistivity and layer thickness were depicted in the figures of said patent application.
• the silver-containing layers of the present invention still show improved adherence to inorganic substrates such as glass. It was further found that this composition was of particular use when applying a heat treatment between 250 and 450°C, more preferably between 250 and 350°C. These profitable properties make silver-containing films of the composition of the invention very suitable for application in AMLCD, passive integration, high temperature-resistant reflective layers (such as used in Fast Intelligent Tracking-FIT), and in reflective displays using substrates that cannot stand temperatures higher than about 350°C. It is stressed that addition of magnesium salt to silver has been described by Lee et al, Journal of the Korean Physical Society. 40(1 ⁇ ). January 2002, 110- 114. However, these authors have added as much as 5 atom% of Mg to the silver using a sputtering process.
• the obtained layers will contain crystallized magnesium salt and are unsuitable to be applied as silver layers in displays and the like. It was now found that it is essential to make layer containing less than 2 atom% of the metal in silver to obtain layers that can be used in displays.
• the metal salt can be an inorganic salt such as metal oxide, metal nitrate, metal carbonate, metal phosphate, and the like or an organic salt such as metal acetate, metal propionate, metal citrate, metal stearate, metal tartrate, and the like. It is also possible to use mixtures of such salts, including mixtures of inorganic and organic salts.
• these metal salts are magnesium salts, more preferably an organic salt of magnesium or magnesium nitrate. Most preferably the magnesium salt is magnesium acetate or magnesium nitrate.
• the composition comprises ⁇ 1 atom% of the metal, most preferably 0.25 to 0.5 atom%. At concentrations higher than 2 atom% the conductivity decreases as the result of disturbance of the silver metallic structure.
• composition of the invention is a colloidal silver sol comprising the metal salt. These sols are very stable and have a long pot life. Application of these sols onto a substrate can simply be performed in the manners known in the art, for instance by a spin-coating or printing process.
• the composition is usually brought onto a substrate, usually an inorganic substrate such as glass to form a temperature-resistant electrically-conductive silver- containing layer. These layer can be used, inter alia, in an active matrix liquid crystalline display (AMLCD).
• AMLCD active matrix liquid crystalline display
• compositions are also very suitable for making silver- containing layers for use in a device wherein the silver-containing layer is exposed to a temperature of 250°C to 350°C.
• Such conductive layers can also be applied to an article, such as an AMLCD, a organic electroluminescent (display) device or plasma display panel, or in IR reflective stacks.
• Fig. 1 shows a graph of the resistivity R (in ⁇ cm) versus the curing temperature T (in °C ) of a silver layer in accordance with the invention (triangles) and not in accordance with the invention (squares);
• Fig. 2 shows a graph of the relative density d (in dimensionless units) versus the curing temperature T (in °C ) of a silver layer in accordance with the invention (triangles) and not in accordance with the invention (squares).
• Magnesium acetate was added to a dispersion of silver colloids in water (obtained from Nippon Paint; sol contains 17 wt.% of silver and 13 wt.% of organic stabilizer) to obtain 0.25 atom% of magnesium in the silver.
• the mixture was diluted with water to obtain the desired viscosity.
• Comparative example MTMS-containing silver layers were made by mixing MTMS (methyl trimethoxy silane) and silver colloids in water (obtained from Nippon Paint as above) according to the method as described in NL 010800 to obtain a suspension containing 3 atom% of silicon in the silver.
• the layers of the Example and the comparative example were deposition onto a Corning® 1737 substrate by spin-coating and dried at 80°C for 5 min. After a pre-cure at 210°C in air the samples were cured in a tube oven under a 100% oxygen atmosphere. The heating rate was 25°C/min and the samples were held at the end temperature for 30 min.
• the sheet resistance was measured using a 4-point contact probe and the layer thickness was measured using an Alpha Step, from which values the resistances were calculated.
• RBS measurements were used to obtain quantitative measurements of silver.
• Fig. 1 the resistivity is depicted as function of the curing temperature.
• Fig. 2 the densification of the silver layer is depicted as function of the curing temperature.
• the metal salts Mg(N03)2- Ca(N03)2 Sr(N ⁇ 3)2 Ba(NC>3)2 and Y(Ac) 3 provided results similar the exemplary Mg-salt.
• Co(Ac) 2 also provided good results.
• Resistance to corrosion may be enhanced by adding further metal salts such as a copper and/or a palladium salt.
• an "APC" coating of silver comprising 0.9 at% Pd and 1.7 at% Cu can thus obtained by wet deposition instead of sputtering.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Nanotechnology (AREA)
• Materials Engineering (AREA)
• Dispersion Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Organic Chemistry (AREA)
• Metallurgy (AREA)
• Mechanical Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Physics & Mathematics (AREA)
• General Chemical & Material Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Composite Materials (AREA)
• Physics & Mathematics (AREA)
• Crystallography & Structural Chemistry (AREA)
• Conductive Materials (AREA)
• Surface Treatment Of Glass (AREA)
• Manufacture Of Metal Powder And Suspensions Thereof (AREA)
• Non-Insulated Conductors (AREA)
• Paints Or Removers (AREA)
• Laminated Bodies (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Devices For Indicating Variable Information By Combining Individual Elements (AREA)
• Powder Metallurgy (AREA)

Applications Claiming Priority (3)

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• 2004
  • 2004-01-20 WO PCT/IB2004/050037 patent/WO2004069452A2/en not_active Application Discontinuation
  • 2004-01-20 KR KR1020057014642A patent/KR20050098908A/ko not_active Application Discontinuation
  • 2004-01-20 JP JP2006502530A patent/JP2006521665A/ja not_active Withdrawn
  • 2004-01-20 US US10/545,122 patent/US20060075849A1/en not_active Abandoned
  • 2004-01-20 EP EP04703455A patent/EP1594996A2/de not_active Withdrawn
  • 2004-01-20 CN CNA200480003854XA patent/CN1748041A/zh active Pending
  • 2004-02-06 TW TW093102791A patent/TW200427532A/zh unknown

Non-Patent Citations (1)

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