Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/12—Selection of substances for gas fillings; Specified operating pressure or temperature
  • H01J61/18—Selection of substances for gas fillings; Specified operating pressure or temperature having a metallic vapour as the principal constituent
  • H01J61/20—Selection of substances for gas fillings; Specified operating pressure or temperature having a metallic vapour as the principal constituent mercury vapour
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C13/00—Alloys based on tin
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C7/00—Alloys based on mercury
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/24—Means for obtaining or maintaining the desired pressure within the vessel
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/24—Means for obtaining or maintaining the desired pressure within the vessel
  • H01J61/28—Means for producing, introducing, or replenishing gas or vapour during operation of the lamp
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]

Definitions

• the invention relates to amalgam beads for the introduction of mercury in modern energy-saving lamps.
• Modern energy-saving lamps of the TFL (Tube Fluorescent Lamp) or CFL (Compact Fluorescent Lamp) type belong to the low-pressure gas discharge lamps. They consist of a gas discharge flask filled with a mixture of mercury vapor and argon and internally coated with a fluorescent phosphor. The ultraviolet radiation of mercury emitted during operation is converted from fluorescence coating to visible light by the phosphor coating. The lamps are therefore also referred to as fluorescent lamps.
• the mercury required for the operation of the lamps was formerly metered as liquid metal into the gas discharge flask.
• US Pat. No. 4,145,634 describes the use of amalgam pellets with 36 atomic percent indium which, because of the high mercury content, already contain high liquid fractions at room temperature. The pellets tend to stick together when they get in contact with each other. By coating the pellets with suitable materials in powder form, this can be prevented. Stable metal oxides (titanium oxide, zirconium oxide, silica, magnesia and alumina), graphite, glass powder, phosphors, borax, antimony oxide and metal powders that do not form an amalgam with mercury (aluminum, iron and chromium) are suggested.
• WO 94/18692 describes the use of pellets of zinc amalgam with 5 to 60, preferably 40 to 60 wt .-%, mercury.
• the method described in US 4,216,178 is used, in which the molten amalgam is formed by a nozzle excited to vibration outlet into small Drop is divided and cooled in a cooling medium below the solidification temperature.
• the pellets are not coated according to WO 94/18692.
• amalgam balls from the melt the amalgam must be heated to a temperature at which the amalgam is completely melted. This is guaranteed with a zinc amalgam only at a temperature above 420 0 C with certainty. These high processing temperatures necessitate corresponding safety precautions because of the high mercury vapor pressure due to the toxicity of the mercury.
• JP 2000251836 describes the use of amalgam cells of tin amalgam for the production of fluorescent lamps.
• the tin amalgam preferably has only a low mercury content with a tin / mercury atomic ratio of between 90-80: 10-20. This corresponds to a mercury content of 15.8 to 29.7 wt .-%.
• JP 2000251836 gives no information about how spherical pellets are produced from the amalgam.
• a disadvantage of the Zinnamalgam described in JP 2000251836 is the low mercury content. This makes relatively large amalgam balls necessary if a certain amount of mercury is to be introduced into the discharge lamps. Because of the increasing miniaturization even in energy-saving lamps, this can lead to problems in the design and manufacture of the lamps.
• amalgam balls of a Zinnamalgam which has a mercury content between 30 and 70 wt .-%.
• the amalgam spheres preferably have a mercury content of from 30 to 60 and in particular from 40 to 55% by weight.
• the balls can be produced from a melt of the amalgam according to a method described in EP 1381485 B1. For this purpose, this will be fully molten amalgam dripped into a cooling medium at a temperature below the solidification temperature of the amalgam. Preferably, the temperature of the cooling medium is 10 to 20 0 C below the liquidus temperature of the amalgam. It is advantageous here that Zinnamalgame completely melt already at temperatures below 230 0 C. The expense of ensuring job security in the production of Zinnamalgam balls is therefore significantly lower than in the case of zinc amalgam balls.
• the cooling medium used is preferably a mineral, an organic or a synthetic oil.
• Well proven has a silicone oil. After formation of the amalgam balls in the cooling medium, they are separated from the cooling medium and degreased.
• amalgam spheres with diameters between 50 and 2000, preferably between 500 and 1500 microns are suitable.
• the tendency of the amalgam beads to adhere can be largely suppressed if the defatted beads are coated with a metal or alloy powder which forms an amalgam with mercury. Due to the amalgamation of the metal powder, a surface layer with a low mercury content is formed on the spheres, which no longer contains any liquid phases at the usual processing temperatures of the amalgam spheres and thus prevents the tendency to stick to the untreated spheres.
• the metal or alloy powder used for the coating should not contain particles with a grain diameter greater than 100 ⁇ m. Particles with larger grain diameters amalgamate only incomplete and lead to a rough surface of the balls, which makes it difficult to meter the balls.
• a meter used tall- or alloy powder whose powder particles have a particle diameter of less than 80 microns. Particular preference is given to metal or alloy powders having an average particle diameter d 50 between 5 and 15 ⁇ m.
• Suitable metals have been found to be tin and zinc or an alloy of tin or zinc. Tin or a tin alloy are preferred. Good results have been obtained with alloys of tin with silver and copper, especially with the alloy SnAg3CuO, 5.
• the balls can be presented for example in a rotating vessel and sprinkled with continuous circulation with the metal or alloy powder until no sticking of the balls is more detectable.
• the amount of metal or alloy powder applied here to the amalgam beads is between 1 and 10, preferably between 2 and 4,% by weight, based on the weight of the amalgam beads.
• the amalgam balls additionally contain a powder of a metal oxide in an amount of 0.001 to 1, preferably 0.01 to 0.5 and in particular in an amount of 0.1 wt .-%, based on the weight of the amalgam balls are coated.
• a powder of a metal oxide in an amount of 0.001 to 1, preferably 0.01 to 0.5 and in particular in an amount of 0.1 wt .-%, based on the weight of the amalgam balls are coated.
• Suitable metal oxides for this coating are, for example, titanium oxide, zirconium oxide, silicon oxide and aluminum oxide. Preference is given to using an aluminum oxide produced by flame pyrolysis with an average particle size of less than 5, preferably less than 1 micron.
• the applied powder layers improve the handling of the amalgam balls with dosing machines.
• the amalgam spheres can be on average for up to three hours at room temperature before they are filled in a fluorescent lamp. It has been shown that the coated with metal or alloy powder and metal oxide powder amalgam balls survive the mean residence time of 3 hours at temperatures of up to 40 0 C in dosing without complaint. If only one of the two layers applied, it comes even before the average duration of residence of 3 hours to isolated separation of the applied layers.
• the following table shows calculated values for the total mass (Sn + Hg) and the mercury mass (Hg) of tin amalgam spheres as a function of the diameter of the spheres and for tin amalgams with mercury contents between 20 and 50 wt%.
• the table also shows the densities p of the different amalgams used in the calculations.
• amalgam spheres made from a SnHg50 containing 50% by weight of mercury contain about three times the mass of mercury, such as amalgam spheres made of SnHg20 with only 20% by weight of mercury.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Manufacture Of Metal Powder And Suspensions Thereof (AREA)
• Powder Metallurgy (AREA)
• Discharge Lamp (AREA)
• Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Luminescent Compositions (AREA)
• Battery Electrode And Active Subsutance (AREA)

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Related Child Applications (2)

Publications (1)

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Citations (5)

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• 2007
  • 2007-04-28 PL PL07008717T patent/PL1985717T3/pl unknown
  • 2007-04-28 EP EP07008717A patent/EP1985717B1/de not_active Not-in-force
  • 2007-04-28 AT AT07008717T patent/ATE514797T1/de active
• 2008
  • 2008-04-22 DE DE502008000912T patent/DE502008000912D1/de active Active
  • 2008-04-22 JP JP2010504659A patent/JP5193285B2/ja not_active Expired - Fee Related
  • 2008-04-22 PL PL08736446T patent/PL2145028T3/pl unknown
  • 2008-04-22 CN CN2008800124670A patent/CN101960027B/zh not_active Expired - Fee Related
  • 2008-04-22 US US12/595,762 patent/US8497622B2/en not_active Expired - Fee Related
  • 2008-04-22 EP EP08736446A patent/EP2145028B1/de not_active Not-in-force
  • 2008-04-22 WO PCT/EP2008/054839 patent/WO2008132089A1/de not_active Ceased
  • 2008-04-22 CN CN2013101061972A patent/CN103194638A/zh active Pending
  • 2008-04-22 AT AT08736446T patent/ATE473307T1/de active
• 2012
  • 2012-12-14 JP JP2012273008A patent/JP5599449B2/ja not_active Expired - Fee Related
• 2013
  • 2013-06-27 US US13/929,096 patent/US9324555B2/en not_active Expired - Fee Related

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