Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B17/00—Forming molten glass by flowing-out, pushing-out, extruding or drawing downwardly or laterally from forming slits or by overflowing over lips
  • C03B17/04—Forming tubes or rods by drawing from stationary or rotating tools or from forming nozzles
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B32/00—Thermal after-treatment of glass products not provided for in groups C03B19/00, C03B25/00 - C03B31/00 or C03B37/00, e.g. crystallisation, eliminating gas inclusions or other impurities; Hot-pressing vitrified, non-porous, shaped glass products
  • C03B32/02—Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles
• • 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
  • C03C10/00—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
  • C03C10/0009—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing silica as main constituent
• • 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
  • C03C10/00—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
  • C03C10/0018—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing SiO2, Al2O3 and monovalent metal oxide as main constituents
  • C03C10/0027—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing SiO2, Al2O3 and monovalent metal oxide as main constituents containing SiO2, Al2O3, Li2O as main constituents
• • 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
  • C03C10/00—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
  • C03C10/0036—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing SiO2, Al2O3 and a divalent metal oxide as main constituents
  • C03C10/0045—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing SiO2, Al2O3 and a divalent metal oxide as main constituents containing SiO2, Al2O3 and MgO as main constituents
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B33/00—Engines characterised by provision of pumps for charging or scavenging
  • F02B33/32—Engines with pumps other than of reciprocating-piston type
  • F02B33/42—Engines with pumps other than of reciprocating-piston type with driven apparatus for immediate conversion of combustion gas pressure into pressure of fresh charge, e.g. with cell-type pressure exchangers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
  • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
  • F02M61/166—Selection of particular materials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
  • H01T13/00—Sparking plugs
  • H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
  • H01T13/38—Selection of materials for insulation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
  • F05C2203/00—Non-metallic inorganic materials
  • F05C2203/08—Ceramics; Oxides

Definitions

• the present invention relates to a method for producing a lighting device or components of a lighting device, in particular starting from glass ceramic green glass.
• the glass ceramics which are obtained from the glass ceramic green glass preferably have the shape of a glass ceramic tube. They can be used in a wide range of applications or in a wide variety of types of lamps, for example in the field of general lighting or automotive lighting or in temperature radiators such as halogen lamps or incandescent lamps or in high-pressure or low-pressure discharge lamps. In particular, the glass ceramics can also be used in miniaturized form for backlighting in connection with the backlighting of flat screens.
• the glass ceramics according to the invention are also preferably suitable as outer bulbs for high-pressure metal halide discharge lamps, for example those with burners made of Al 2 O 3 Ceramic, wherein the lamp bulb made of the glass ceramic according to the invention separates the space around the burner from the outside atmosphere.
• the transparent bulbs preferably made of glass or translucent ceramic in a stretched cylindrical or compact bulbous shape, essentially have two different tasks, as described below.
• lamps or applications are defined in which the glass bulb is used as the first envelope of the light-emitting unit, for example of the filament, and / or as a hermetically sealed body for protective or discharge gases.
• These applications are referred to as Type A applications in the present application.
• Type A applications are applications in which the glass bulb is the first envelope of the light-emitting unit.
• This includes in particular lamps of the type “light bulb” or “halogen spotlight” in which a current-carrying and therefore strongly heated tungsten filament emits light, for example light bulbs or halogen spotlights.
• the bulbs of such lamps are filled with “heavy” gases such as krypton, argon or xenon
• Halogen lamps are halides that guide tungsten that evaporates from the filament away from the colder inner walls of the bulb and separate it again on the tungsten filament. This is known as the halogen cycle. With the help of halogen additives, it is possible to reduce the bulb blackening within a certain temperature range due to the evaporation
• the glass bulb forms the reaction space of a gas discharge.
• the glass bulb can also act as a carrier for light-converting layers.
• Such lamps are, for example, low-pressure fluorescent lamps and high-pressure gas discharge lamps.
• liquid or gaseous substances often mercury (Hg) and / or xenon (Xe) and / or neon (Ne) - are excited by arc discharge between two electrodes protruding into the bulb and stimulated emission, mostly in the UV range brought.
• the discrete UV lines are partially converted into visible ones by means of fluorescent layers.
• the filling gases are put under high pressure up to 100 bar or more.
• the discrete lines degenerate into emission bands with the consequence that quasi white light is emitted.
• optically active substances for example halides of the rare earths, in particular dysprosium halides, or alkali halides, which lack spectral Fill up portions and increase color fastness.
• the dependence of white quality on printing is described in Derra et al. in "UHP lamps: light sources of extremely high luminance for projection television", Phys. Bl. 54 (1998) No. 9 817-820.
• the disclosure content of this publication is fully incorporated into the disclosure content of the present application.
• the glass bulb serves as a second envelope, for example for thermal encapsulation of the actual light-emitting unit and / or for breakage / explosion protection or for protecting materials and the lamp user from harmful rays, in particular from UV rays. Rays.
• Type B applications relate, for example, to high-pressure discharge lamps.
• the burners of high-pressure discharge lamps made of silica glass or translucent ceramics (eg Al 2 O 3 , YAG ceramics), are operated at the highest possible operating temperatures up to 1000 ° C or above. The higher the operating temperatures, the higher the color rendering index and the effectiveness and the smaller the differences in light quality from lamp to lamp.
• a second glass envelope bulb is placed around the actual reaction body, the space in between being mostly or essentially evacuated.
• the envelope bulb is also doped with UV blocking components.
• a high-pressure discharge lamp is to be operated directly in a lamp holder without further protective measures, i.e. if the lamp is not integrated in a luminaire with a cover plate, as is known from superstructures of low-voltage halogen lamps, further cylindrical transparent elements are inserted between the envelope bulb and the discharge bulb, which are to serve as explosion protection , Due to the different areas of application, there are different requirements for the piston glasses used for glasses in type A and type B applications.
• Type A applications require thermally very stable materials, for example glasses, which do not deform under the loads of the spatially close tungsten filament or the high operating temperatures under pressure, in particular the high pressure which results from HID (high intensity discharge).
• the glass bulbs are also under internal pressure between 2 and approx. 30 bar for halogen lamps or up to approx. 100 bar or more for HID lamps.
• the pistons must also be chemically very inert, ie they must not react in contact with the fillers. This means that no components from the glass may be released into the environment, in particular no alkalis or OH ions or H 2 O.
• the transparent materials can be permanently hermetically sealed with the feed metals.
• the glass bulb should be able to be fused with W or Mo metal or with Fe-Ni-Co alloys (eg Kovar.Alloy 42).
• the bushings fused in this way should also be stable with respect to temperature change cycles.
• Backlighf lamps are low-pressure discharge lamps that can be miniaturized in TFT (" thin film transistor ") displays, for example for screens, monitors, TV sets, for backlighting.
• TFT thin film transistor
• Multicomponent glasses based on silicate have previously been used “Backlighf lamps place high demands on the shielding of UV light through the glass of the lamp itself, as other components especially those made of plastic, quickly age and degenerate in the flat screen monitors.
• the requirements for temperature resistance and chemical composition / resistance are generally lower than in type A applications.
• the outside bulb temperature is around 300 - 700 ° C depending on the distance between the hot spot of the burner and the bulb. Accordingly, the bushing area is significantly colder than the piston volume directly adjacent to the burner.
• wall temperatures of up to 800 ° C or above can also prevail.
• these pistons should have a high UV blocking, especially in “backlighf applications”.
• materials for glass bulbs in type A applications are soft glasses for light bulbs, alkali-free hard glass for automotive halogen lamps or silica glass for halogen lamps or HID lamps for
• high-power discharge lamps also use translucent aluminum oxide which can be loaded up to 1100 ° C. or above.
• EP 748 780 B1 or Krell et al Transparent sintered corundum with high
• comparatively soft glass for example borosilicate glass, can be used as the glass bulb material.
• the materials used for the glass bulb for type B applications are currently mainly silica glass or multi-component glasses such as. B. of the Suprax type (SCHOTT Type 8655 or DURAN-Glass from SCHOTT GLAS Mainz).
• Glass ceramics with preferred properties for targeted use in special applications are known from the prior art and the prominent brands of the applicant, Ceran® and Robax®, may be mentioned by way of example. Glass ceramics such as those mentioned have a unitary spectrum of properties which result from targeted, controlled, temperature-controlled, partial crystallization. Depending on the composition, the way in which the starting glass, which is also called “green glass”, is produced and the temperature regime in hot post-processing (which also includes the so-called ceramization, i.e. the conversion of the green glass into a glass ceramic), different crystal phase types can be used in a glass ceramic , crystallographic species with different crystal morphology and size as well as different amounts of crystal.
• the patent specification DE 37 34 609 C2 relates to calcium phosphate glass ceramics, which can also be used in discharge tubes.
• the main crystal phase in these glass ceramics is apatite, as a result of which the glass ceramic has a high coefficient of thermal expansion, which is also desirable according to DE 37 34 609 C2.
• the patent does not disclose any glass ceramic which has a coefficient of thermal expansion smaller than 6 x 10 "6 / ° K.
• the glass ceramics described in DE 37 34 609 are highly expansive with at least 6 ppm / K, the glass ceramics containing calcium phosphate are generally not suitable for lamp applications due to their low chemical stability. This applies particularly to those
• US 4,045,156 describes the use of partially crystallized glass for applications in photoflash lamps. These lamps are characterized by a higher temperature resistance, higher thermal shock resistance and mechanical strength than conventional glass bulb lamps. The coefficient of expansion is mainly due to the precipitation of lithium disilicate crystals from the corresponding starting glasses at approx. 8.0-9.5 ppm / K. The reason for this is that, in US 4,045,156, the glass ceramic expands to high-expansion lead-through metals - or alloys, e.g. B. Cu leading Ni-Fe alloys is adjusted. The crystallites of the glass ceramic have a size in the range from 50 nm to 10 ⁇ m. US 4,045,156 also describes process steps from melt, tube drawing to ceramization processes. The fully ceramized pipe is described as sufficiently processable. A procedure for the production of a complete lamp is not described, in particular not how it can be achieved that such a lamp is guaranteed to have sufficient tightness in the area of the implementation.
• No. 3,960,533 describes the use of translucent ceramic-coated glass ceramics as shading in front of the bright tungsten filament in a light bulb.
• the glass ceramic used in US 3,960,533 in the composition of the glass ceramic known from US 4,045,156, but in a translucent ceramicized form.
• a glass ceramic comprising larger amounts of Ta 2 0 5 and / or Nb 2 Os (5 to 20% by weight in the starting glass) with more than 50% by volume of amorphous phases is described in US Pat. No. 4,047,960.
• it is disadvantageous that when recognizable amounts of Ta 2 0 5 - and / or Nb 2 0 5 are introduced, the formation of “charge transfer complexes” in the glass ceramic leads to undesired discoloration US 4,047,960 No information was given on pulling the green glasses into tubes and their further processing into a lamp body.
• GB 1260933 describes glass ceramics which are suitable for applications in sodium vapor lamps. They are chemically very stable to sodium vapor and, in addition to being used as sealing materials, can also be used as parts of lamp bodies.
• the glass ceramic is Si-free with the main components CaO and AI 2 O 3 and stable up to approx. 900 ° C.
• the glass ceramic bodies described in GB 1260933 are not suitable for Na high pressure lamps.
• DE 100 17 696 A1 and DE 100 17 701 C2 describe the use of glass ceramics as cover plates for radiation sources from lamps, in particular halogen lamps.
• a method for producing lamps comprising, for example, a glass ceramic as material for the glass bulb is not known from the prior art.
• a method has to be carried out in order to achieve a hermetically sealed bushing between the lamp bulb, for example made of glass ceramic, and a bushing material - for example a tungsten bushing.
• the object of the invention is to overcome the disadvantages of the prior art.
• methods are to be specified with which
• Lighting device in particular lamps comprising glass ceramics can be produced.
• the procedure should be carried out so that the implementation is largely hermetically sealed.
• the object is achieved by a method according to claim 1 or claim 13 and an apparatus according to claim 31.
• Advantageous refinements are the subject of the dependent claims.
• the invention is to be described below on the basis of exemplary embodiments comprehensively the possible individual process steps from drawn green glass to a lamp body.
• the steps are generally shown for specific lamp types, but are not limited to these.
• Combinations of the steps described in the individual exemplary embodiments can be put together in a suitable manner for the construction of lamps other than those specified in the exemplary embodiment.
• FIG 1 RAMAN spectrum of through-ceramized and glassy material
• Figure 2 Tubular glass that can be used to produce a "backlight lamp” Figure 3a, b bulbs, as they can be used to produce an HID lamp in different embodiments.
• glass-ceramic materials in lamp construction.
• highly stable, transparent glass ceramics which are tailored to other requirements and which far exceed conventional glasses in use according to the prior art.
• this is particularly the case with low-pressure lamps, e.g. B. backlight lamps, in which glass ceramics, for example, offer advantages in the field of "UV blocking" with high overall transparency.
• glass ceramics as outer bulbs for high-pressure metal halide lamps, for example those with Al 2 O 3 ceramic burners.
• combinations of properties can be used in the case of glass ceramics, since glass ceramics are partially crystallized glasses which use the advantageous properties of glass in combination with crystals.
• the Crystallites are so small, for example ⁇ 1 ⁇ m, preferably ⁇ 200 nm, particularly preferably ⁇ 100 nm, so that the material, like glass, remains transparent, but causes a number of improved properties, such as high temperature resistance, high resistance to temperature changes, high mechanical strength, and high chemical resistance and high UV blocking.
• the type, volume fraction and size distribution of the crystallites can be specifically adjusted with respect to other properties, depending on the chemical starting composition and the way the ceramization is carried out.
• the thermal expansion coefficient should be mentioned in particular, the z. B can be adapted to an implementation material.
• thermal expansion coefficients ⁇ 2 o / 3oo between 0 and ⁇ x 10 "6 / K, preferably between 3 x 10 " 6 / K and 5.5 x 10 "6 / K can be achieved with glass ceramics.
• Mergers with molybdenum expansion coefficients between 4.2 x 10 "6 / K and 5.3 x 10 " 6 / K are particularly preferred.
• expansion coefficients between 3.8 x 10 "6 / K and 5.2 x 10 " 6 / K are particularly preferred.
• Li 2 0-SiO 2 -AI 2 ⁇ 3 glass ceramics can also be produced in such a way that they have an expansion coefficient of 0 to 2 ppm / K or preferably ⁇ 1 ppm / K.
• This glass ceramic can then be easily adapted to common lamp glass materials such as SiO 2 , ie fused or ridden with the latter.
• Glass ceramics for lamp construction can be in the form of tubes, which is particularly useful if the glass ceramic is used as part of a lamp. If necessary, tubes can be converted into spherical or ellipsoidal shapes. Hollow spheres or hollow ellipsoids can regardless of a previous pipe shape, can also be produced directly by blowing and pressing.
• Glass ceramic tubes in tubular or tube-like form can also be used as outer bulbs in HID (high intensity discharge) lamps, e.g. B. high pressure
• tubular is understood to mean a hollow body with an outer wall and at least one opening, the cross section of which is circular, whereas “tubular” corresponding cross sections of other closed geometry, eg. B. elliptical, oval or rounded-angular.
• requirements for glass ceramics for use in lamp construction include, for example, good temperature stability with excellent transparency.
• Tg transformation temperatures
• Tg transformation temperature
• the viscous flow of a glass ceramic used in lamp construction only begins at higher temperatures than with silica glass. It is particularly preferred if the glass ceramic is similarly stable or even more stable than translucent ceramics, for example those based on Al 2 O 3 . In addition to the excellent temperature stability, the glass ceramics should have a high transmission in the visible range (between 380 nm and 780 nm) with a layer thickness of 0.3 mm, for example> 75%, preferably> 80%, particularly preferably> 90%. This property is important when using glass ceramics as parts of a lamp. Glass ceramics which have a wall thickness of 1 mm in the wavelength range between 400 and 780 nm, preferably> 75%, particularly preferably> 80% transmission, are also particularly preferred.
• Blocking means a transmission of less than 1% with a layer thickness of 0.3 mm.
• the blocking can be achieved for wavelengths ⁇ 260 nm, preferably ⁇ 300 or ⁇ 315 or ⁇ 365 nm.
• silica glass with a wall thickness of approximately 1-1.5 mm is currently used as the outer bulb material.
• the silica glass is usually doped with Ce0 2 in contents of ⁇ 1% by weight.
• the disadvantage is that the glass in the area of hard, high-energy UV C and D
• Radiation below 300 nm still has residual transmission in the order of 10% or more. This wavelength range can be completely blocked with a high-temperature resistant multi-component material such as glass ceramic. Glass ceramics therefore provide improved UV blocking and improved fusibility or joinability with lead-through metals compared to the glasses previously used in the prior art.
• the glass ceramic or green glass should be easily fusible with electrical ones
• Bushings which, depending on the application, are made of molybdenum, tungsten or alloys such as Vacon 11® from CRS Holdings Inc., also known as "Kovar” designated will exist.
• the inventive manufacturing such glass-ceramics can, '' enable a hermetic closure of an electrically and thermally conductive Met? “J” ch Entry and the piston material and problems of thermal expansion of glass and metal, are formed with respect to by different properties can be circumvented ,
• thermal expansion coefficients ⁇ 2 o / 3 oo between 0 and ⁇ 6 x 10 "6 / K, preferably between 3 x 10 " 6 / K and 5.5 x 10 "6 / K can be achieved.
• coefficients of expansion between 3.4 x 10 "6 / K and 4.4 x 10 " 6 / K and for mergers or joining with molybdenum expansion coefficients between 4.2 x 10 "6 / and 5.3 x 10 " 6 / K.
• the glass ceramic can preferably be designed such that the thermal expansion of the electrode material, consisting of metal, is approximated, so that it is advantageously achieved that no leaks occur even at operating temperature during lamp operation.
• the materials are chemically resistant, so that, for. As operations are not affected permanently in a lamp.
• a disturbance in the halogen circuit should be avoided in particular.
• the materials should not be penetrable by fillers, i.e. they should have good long-term tightness. Hot, pressurized fillers should not cause any corrosion.
• the glass ceramics can be used in lamps at least in the uppermost layers of the Inner tube surface, preferably in the entire lamp bulb body, should be alkali-free and meet the highest purity requirements.
• the ceramization takes place in a multi-stage process, which is characterized by heating ramps and holding times.
• the maximum temperature is 1200 ° C
• the holding times are adapted to the optimal crystallite growth - based on a given requirement profile of optical and thermal target values.
• the crystallite size is preferably in the order of 10 to 200 nm
• the crystal phase fraction is preferably at least 50% by volume, preferably more than 60% by volume, particularly preferably more than 70% by volume, in particular more than 80% by volume.
• glass ceramics are to be in tube form, for example, green glass tubes that were previously drawn are converted into glass ceramics by means of ceramicization programs known to the person skilled in the art.
• the ceramization programs are to be designed in such a way that the glass ceramic obtained is optimized for the respective application with regard to the properties required.
• the glass ceramic properties are a consequence, in particular, of the type, amount and size of crystal, as well as the composition and properties of the residual glass. For optimal thermal stability, it can be useful to minimize the glass content within the glass ceramic and / or to adjust the composition of the residual glass phase close to the pure silica glass.
• ceramization programs are adjusted with regard to the temperature and time regimes and matched to the desired crystal phases, as well as to the ratio of residual glass phase and crystal phase content as well as crystal litite size.
• the surface mechanism or a depth profile for certain elements can be set by the ceramization program, whereby a desired content of alkalis can be set in the course of the ceramization in areas close to the surface, even in the fine adjustment from “low in alkali” to “alkali-free”.
• a concentration gradient can also be built up for certain elements, which can be brought about by their incorporation into the crystal phase or by their remaining or enrichment in the residual glass phase, in particular by the formation of a glassy surface layer, the thickness of which depends on the composition of the starting glass and the Ceramization atmosphere can be determined.
• in-situ ceramization it is also possible to ceramize directly during lamp operation (“in-situ ceramization”) by setting certain current-voltage-time profiles, which lead to heat radiation through the lamp filament, with which corresponding nucleation and crystal growth temperatures as well as heating and Allow cooling rates in the lamp body to reach.
• Ceramization program is also, if necessary, regarding nucleation or crystal development regime adapted to the desired level of shielding from UV radiation.
• the UV blocking properties (ie the position / slope of the absorption edge) of the glass ceramic can be tailored by a number of measures: In addition to the introduction of UV blocking additives, such as. B. Ti0 2 , there are further setting options for glass ceramics compared to glasses: for example the particle size which is adapted with regard to maximum UV scatter, and the particle size distribution. In general, the more homogeneous the size of the particles, the steeper the UV edge.
• the glass ceramic can also be set with respect to the starting glass and the ceramization status such that the active dopant Ti is ideally distributed over the residual glass phase and crystal phase. The larger the crystal particles, the greater the UV blocking properties.
• Particle sizes in the range 10-100 nm are preferred, with a monomodal particle distribution being preferred and preferably at least 60% of the particles present being within this size range, the proportion of crystal phase in the total volume preferably being at least 50% by volume and at most 90% by volume. % is.
• the UV blocking can be adjusted.
• the ceramicized tube is superior to a non-ceramicized tube of the same composition, ie its green glass tube, in terms of UV blocking properties. It is therefore extremely suitable for the uses according to the invention.
• Ceramization regimes are also possible to generate a hermetically sealed transition from glass to an electrical feedthrough. It is conceivable that shrinkage of the material during the ceramization Develop favorable stress conditions (axial / radial) and thus provide a hermetically sealed connection.
• glass ceramic materials that are adapted in terms of their thermal expansion (preferably both in the glassy and in the ceramicized state)
• more massive metal bushings instead of very thin Mo sheets, used e.g. in halogen lamps based on silica glass
• a state in which the lamp “seals itself” during operation can also be set by suitable ceramization or the use of suitable heating methods for shaping the starting glass.
• GC Alkali-free glass ceramics
• AF-GC Alkali-free glass ceramics
• 35-70 preferably 35-60 Si0 2
• P 2 O 5 preferably ⁇ 4% by weight
• the glass ceramics are characterized by the main crystal phases spinel, sapphirine, high quartz mixed crystal (HQMK), alpha quartz, cordierite and corresponding mixed crystals (in particular Zn spinels / sapphirine; Mg / Zn-HQMK).
• a crystal phase is to be referred to as the main crystal phase, the proportion of which in the sum of all crystal phases is greater than 5% by volume.
• Secondary crystal phases are those crystal phases whose share in relation to the sum of all crystal phases is less than 5% by volume.
• llmenite M 2+ Ti0 3
• llenorutile M 3+ x Ti 4+ y
• rutile M 4+ ⁇ Tiy0 2 ⁇ + 2 y
• M denotes a metal.
• the metal M can be selected from the following group:
• Fe or other transition metals such as Cu, Mn, Co, Ni, which form divalent cations. If these metals are not included in the synthesis, they can be entered into the glass as impurities via the raw materials.
• Form cations such. B. Nb or Ta, such as. B. (Ti, Nb, Fe 3+ ) 3 0 6 or (Ti, Ta, Fe 3+ ) 3 O 6
• Calcium-containing crystal phases such as. B. anorthite (CaAI 2 Si 2 O 8 ) or calcium phosphate (especially apatite), are undesirable because of their known opacifying effect and low chemical resistance as main crystal phases, the formation of which is determined by the amounts Avoided phosphorus oxide and calcium oxide in the glass ceramic.
• Main crystal phases made from aluminum niobate and / or aluminum tantalate and / or aluminum niobate tantalate are also undesirable. Less than 5% by weight of niobium and / or tantalum oxide is preferably used in the starting melt.
• compositions (in% by weight) based on oxide are used as alkali-containing glass ceramics, referred to as “AH-GC”, for example when used as low-pressure discharge lamps, in particular as “backlighf lamps for use in TFT displays:
• 0-4 common refining agents are e.g. B. Sn0 2, Ce0 2 , S0 4 , Cl, As 2 0 3,
• the glass ceramics are characterized by the main crystal phases HQMK (high quartz mixed crystal), keatite.
• Both types of glass ceramics mentioned above can also be used with particular preference as outer bulbs for metal halide high-pressure discharge lamps.
• High-halogen halide high-pressure discharge lamps with a CDM-Tc type silica glass bulb are described, for example, on the Philips website at www.philips.com. The content of the disclosure of these documents is fully incorporated into the present application.
• compositions are to be regarded as examples of the glass ceramics indicated.
• Example 1 describes compositions of alkali-containing glass ceramics which have proven to be advantageous in tube drawing tests and which can be used in tube form in lamp construction:
• the thermal expansion changes from 3.9 ppm / K for the green glass to a value ⁇ 1 ppm / K for the ceramized glass, i. H. the glass ceramic.
• Example 2 describes compositions of an alkali-free glass ceramic which is suitable in tube form for use in lamp construction: % By weight component
• the ceramization changes the thermal expansion from 2.8 ppm / K for green glass to 3.8 ppm / K for glass ceramics.
• compositions given above are compositions of the starting glass, but are retained even after the ceramization.
• the thermal stability of the glass ceramic can be modified by synthesis and different ceramization programs.
• the viscosity of the material as a function of temperature can be used to assess the stability.
• the glass ceramics are superior to the aluminosilicate glass. Furthermore, by adjusting the ceramization conditions, glass ceramics with different optical properties can be produced from the same starting glass, in particular with regard to the UV edge position.
• the starting glasses of the glass ceramics can be produced by melting at a temperature 1, refining at a temperature 2, the temperature 2 being higher than the temperature 1, and then working out in a crucible in a one-step process.
• a two-stage process in a first step, the two-stage process is carried out at high temperatures, for example 1650 ° C., after which, in a second step, it is melted again, refined and worked out.
• Step 1 of the two-stage process should be carried out in a silica glass crucible, step 2 then being able to be carried out in the platinum crucible.
• the remelting can be carried out for two hours, followed by refining at 1450 ° C for twelve hours and then at 1500 ° C for four hours.
• the nozzle is "melted free” with a burner, with some of the glass ceramic starting glass being discarded.
• the hot molding is then carried out at, for example, 1475 ° C.-1485 ° C.
• the resulting glass ceramic tube is heated to 1080 ° C. by means of a subsequent muffle furnace It is important to form tubes in the nozzle located needle, which can protrude up to 10 mm from the nozzle.
• a suitable inner diameter of the nozzle can be 35 mm.
• Suitable tube dimensions for the glass ceramics obtained are, for example: total diameter of 8 mm with 1 mm wall thickness and 6 mm tube inner diameter, which can be obtained at take-off speeds of approximately 34 cm / min; Total diameter of 10.5 mm with 1.2 mm wall thickness, to be obtained at take-off speeds of approximately 16 cm / min; Overall diameter of 13.5 mm with a wall thickness of 1.2 - 1.4 mm, which can be obtained at take-off speeds of around 10 cm / min.
• the indication of the total diameter should in no way be understood as restricting the procedure. With only a few steps modified processes, in particular the use of drawing speeds below 10 cm / min and the use of optimized drawing nozzles, drawing muffle and drawing needle design, it is also possible to process outer diameters up to 25 mm or more crystal-free.
• a green glass tube is first drawn, tapered or melted. Then the tube melted on one side is fitted and the bushing is melted down. The green glass lamp body that is still present after the bushing is melted is then partially or completely ceramized.
• a green glass tube is tapered on one side in a conventional burner flame, for example, or - if no vacuum is required in the outer bulb - completely melted off.
• the tapering or melting takes place either by heating a terminal tube or by Heating in the middle of the pipe and pulling apart or twisting the pipe apart.
• the melting time As well as the geometry and gas and. 0 2 or air exposure to the burner flame, the melting takes place without the occurrence of uncontrolled crystallization phenomena, ie the tube is still in the desired green state after melting.
• the green glass tube which is open on one side, is equipped with a discharge body (in the case of an HID lamp formed from silica glass or translucent ceramic) and the metal feeds located thereon are melted into the outer bulb green glass, if necessary after the outer bulb has tapered.
• a discharge body in the case of an HID lamp formed from silica glass or translucent ceramic
• the metal feeds located thereon are melted into the outer bulb green glass, if necessary after the outer bulb has tapered.
• the green glass is brought to suitable temperatures and pressed against the metal electrodes, for example with a pressing device.
• the green glass's thermal expansion is matched to the metal of the bushing, for example W or Mo. If this is not the case, thin wires, e.g. B. with a diameter of ⁇ 1 mm, preferably ⁇ 0.5 mm or thin foils of thickness ⁇ 100 microns with the green glass tension-free and hermetically sealed. This is also a possible measure if the ceramicization causes an expansion that does not match the metal
• the glass of the composition in the green state has a thermal expansion matched to tungsten and can therefore be fused with it without stress
• the still open but tapered tube end can be melted off by applying a vacuum.
• the ceramization of the entire lamp structure can either be complete or partial, i.e. H. done partially. What is meant here is that the body remains locally green with a transition zone into a fully ceramicized area. The latter is partially crystallized by the temperature / time treatment (see definition at the beginning).
• the partial ceramization is particularly preferred when the ceramization produces a glass ceramic material which in the green state was tightly fused to the metal, but by the
• Ceramization changes the coefficient of expansion of the material significantly. This is the case, for example, with the glass ceramic according to exemplary embodiment 1.
• the thermal expansion coefficient of the green glass largely corresponds to the expansion coefficient of the material of the bushing, for example tungsten. If the green glass is ceramized, the coefficient of expansion changes, as can be seen from the table for exemplary embodiment 1.
• the ceramization is preferably carried out in the areas which do not form the bushing if the coefficient of expansion of the green glass largely corresponds to that of the metal of the bushing.
• the coefficient of expansion of the green glass largely corresponds to that of the metal of the bushing.
• the lamp body in the area of the fusion ie the implementation, has the character of a hard glass (Tg> 650 ° C.) in the hot area, however the required very high temperature stability> 800 ° C and UV blocking, due to the fact that there is ceramicized material in the form of a glass ceramic.
• Lamp body the maximum ceramization temperatures less than 1100 ° C.
• the lamp body here the lamp bulb
• the lamp body is rotated about its axis during the ceramization. In a further particular embodiment, this is done by mounting the lamp on a gas levitation bed.
• the lead-through area is z. B. partially cooled by blowing with air or embedding in water and thus the implementation area in the green state - kept.
• a glass ceramic is preferably selected whose thermal expansion coefficient is as close as possible to the expansion of the
• Implementation material is adapted.
• the glass of the composition according to Example 2 may be mentioned, the ceramized shape of which has the desired elongation of z. B. has tungsten wire.
• a hermetically sealed, low-stress feedthrough can be realized analogously to the case of the fusion of green glass with metal with a suitable choice of the ratio wire thickness / glass thickness.
• a ratio of wire thickness to glass thickness of at least 1: 2, advantageously at least 1: 5, particularly preferably of at least 1:10 perpendicular to the direction of execution is recommended.
• both sides of the bulb - after insertion of the discharge vessel - are fused with the metal feeder attached to the discharge vessel.
• a pump stem possibly also made of green glass, is melted onto the green glass piston tube on the outer bulb. After the metal is melted, vacuum is generated in the inner piston via the pump handle and the latter is melted down again. The ceramization takes place in a manner as described above.
• halogens - as liquids when cooling the lamp body or in the gaseous state under pressure - are introduced or pressed into the lamp body.
• the filled lamp bulb can then be completely or partially ceramized as described above.
• green glass tubes made of material with the composition according to Example 1 can be partially ceramized.
• a piece of pipe (outside diameter ⁇ 4 mm to 14 mm; wall thickness approx. 0.5 mm) with a length of approx. 300 mm was placed in a pipe furnace.
• the heating zone has an extension of approx. 23 cm, but can optionally be extended or shortened.
• a folding tube furnace with open heating elements (length 200 mm) is used.
• the sample chamber is formed by a quartz glass tube (length 400 mm) with inserted AI 2 O 3 ceramic tube (length 230 mm).
• the ceramic tube supports the selective heating of the samples by its absorber effect for the radiation of the heating elements.
• the edges of the heating zone thus become relatively sharp, so that the temperature drops drastically by up to 200 ° C. in a range from 5 mm to 15 mm, particularly preferably ⁇ 10 mm.
• the gradient can be influenced even further by varying the external cooling or letting the pipe ends (one-sided / two-sided) protrude from the furnace.
• the transition area from glass to glass ceramic can be extended by changing the ceramic tube (diameter, holes, length) in order to reduce tension in thick-walled tubes.
• the temperature homogeneity in the heated area is very high and is in the range of ⁇ 20 K, ideally ⁇ 10 K.
• a tube sample that is open on one or both sides is positioned in the tube furnace in such a way that the open ends / the open end protrudes from the heating zone and can be cooled with outside air in a controlled manner.
• FIG. 2 shows a tubular glass that can be used to produce a “backlighf lamp”.
• the central part, designated 20, is ceramicized.
• the metal wires 24.1, 24.2 of the bushings are already inserted into the two open ends 22.1, 22.2.
• the green glass is selected such that the coefficient of expansion of the green glass largely corresponds to the coefficient of expansion of the metal wire 24.1, 24.2. Appropriate guidance of the ceramization ensures that the central part 20 of the “backlighf lamp has a high UV-A blocking.
• a Li are 2 0-AI 2 ⁇ 3 -Si ⁇ 2 ceramic material and used as the implementation of tungsten. It appears, that with a suitable choice of tube dimensions with a diameter of ⁇ 5 mm, preferably ⁇ 3 mm and an oven gradient of> 120 ° C, the transition from the glassy end region 22.1, 22.2 to the ceramicized central part 20 can be largely stress-free, which means that the tube in the Transition area is sufficiently unbreakable. If the transition area is to be very short, this can be accomplished by local furnace cooling or by thermal insulation of the end piece from the remaining piece to be ceramized.
• outer bulbs can also be provided for HID lamps contacted on one side.
• the outer bulbs of such HID lamps in section are shown in FIGS. 3a and 3b.
• FIG. 3a also shows the burner system 1002, which can be designed as an A ⁇ Os burner.
• the burner system 1002 is attached to a nipple 1004.
• the nipple 1004 results when the pump stem is melted after applying the vacuum that exists in the outer bulb.
• the so-called former fusion point then acts as the upper fixed point of the burner system 1004, which is opposite z.
• B. a W filament in a halogen lamp has a significantly larger mass, so that a fixation in the outer bulb is advantageous.
• the lead and lead wires are stiff enough to hold the torch, but greater safety and reproducibility in positioning the torch is obtained when an extension 1010 of the lead wire 1008 is anchored at the top on the nipple 1004.
• the outer bulb 1000 is partially ceramized, namely that a glass ceramic 1000.1 is formed in the area of the burner system 1002, whereas the outer bulb 1000 is a green glass 1000.2 in the area of the bushings.
• the metal feeds on it are melted into the outer bulb green glass 1000.2, if necessary after the outer bulb has tapered.
• the green glass is brought to suitable temperatures and pressed against the metal electrodes, for example with a pressing device.
• FIG. 3b shows an outer bulb 1000 without a holder 1004 for a burner system.
• the same components are identified with the same reference numbers.
• the material can be completely ceramized and this already completely transparent ceramized material can subsequently be fused with metals.
• the open end of a ceramic tube melted on one side is brought into contact with a tungsten wire and melted over a gas flame.
• the glass ceramic locally melts again to form green glass, which, for example in the case of Li2 ⁇ -Al 2 ⁇ 3-Si0 2 glass ceramics, connects hermetically tight to the tungsten wire.
• the burner flame can e.g. B. be designed so that a central, very hot punctiform area> 1500 ° C is embedded in a wide burner tail that does not exceed 700 ° C. In this way, transition regions with low stress states can be generated which have sufficient mechanical breaking strength.
• the flame must have a suitable characteristic for this, characterized by a wide warm area (T less than approx. 700 ° C.) which encloses a hot local area.
• the feed-through wire to be fused lies within the ceramic tube, which is underneath
• Ceramic pipes can also be used without their direct melting with metal bushings.
• a base plate with suitable bushings is provided, the base plate being made, for example, from tempered glass, silica glass or also from glass ceramic.
• the connection to the piston can be made by direct fusion or by using suitable frits, ceramicizing solders or transition glasses. The separation of the glass ceramic bulb from the metal melt is advantageous in terms of a high production yield and process reliability / transparency
• the ceramization can also take place in lamp operation itself.
• for. B uses the thermal radiation emitted by the tungsten filament in type A applications or the residual heat prevailing in the interior of an outer bulb in type B applications to partially ceramize the bulb in situ.
• a lamp operating cycle corresponding to the external ceramization process should be run, for example, in order to achieve the desired one
• melting can also be done optically.
• One such method is kIR technology.
• kIR denotes short-wave infrared radiation.
• DE 199 38 807 describes the use of KLR radiation to form glass parts from a glass item, but is preferably shown on flat glass plates.
• DE 199 38 808, DE 199 38 811 and DE 101 18260 describe the use of kIR radiation for heating semi-transparent glass-ceramic starting glasses, but without reference to round shapes or glass-metal melts.
• An advantage of using kIR radiation compared to using a normal gas flame in connection with the lamp body shaping as described in this application lies in the very rapid and local heating of the glass items. For example, a simple one can be done very quickly and locally
• a particular advantage of using optical radiation, such as klR radiation in the field of lamp construction, is the targeted setting of
• the composite is conventionally heated up to about Tg of the glassy partner.
• the ceramization is carried out after switching over the flame heating to kIR radiation, the metal, here the tungsten wire, being hardly heated or cooled externally.
• the green glass changes into zero-stretching glass ceramic, with a crystallization shrinkage of the order of magnitude of ⁇ 5%.
• this process only lasts for a short time, preferably ⁇ 15 min.
• the composite is very quickly, ideally shock-cooled, and at the end of the process step there is a stress-free metal-glass ceramic composite of a zero-expanding glass ceramic with a W wire. If this composite is heated to operating conditions, the composite seals itself further due to expansion of the W-wire, making it particularly tight for gases under pressure inside a piston.
• AH-GC alkali-containing glass ceramic
• Example 2 Another advantage of the materials mentioned in this application, namely in particular the alkali-containing glass ceramic (AH-GC), which also includes Example 2, is that different crystal phases depending on the ceramization conditions (HQMK) and / or keatite or mixture of these phases can be obtained. This enables the thermal expansion to be set in a range from 0 to 2 ppm / K. In this way it is possible, depending on the choice of the ceramization conditions, to obtain an expansion adapted to the material of the bushing, for example an expansion adapted to the expansion of W.
• HQMK ceramization conditions
• an AF-GC glass ceramic which includes a glass ceramic according to exemplary embodiment 2, it is also possible again to set different crystal phases due to different ceramization conditions and thus also the coefficient of thermal expansion in the range between 2 to 6 ppm / K im Glass ceramic / metal feedthrough area.
• the part of the body that surrounds the illuminant can be a glass ceramic that is transparent, but in the area of the lead-through, a translucent glass ceramic is produced by post-ceramization or another type of ceramization, the expansion behavior of which is adapted to the material of the lead-through.

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• 2005
  • 2005-01-04 WO PCT/EP2005/000013 patent/WO2005067001A2/de active Application Filing
  • 2005-01-04 WO PCT/EP2005/000012 patent/WO2005066088A2/de active Application Filing
  • 2005-01-04 DE DE112005000116T patent/DE112005000116A5/de not_active Withdrawn
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  • 2005-01-04 WO PCT/EP2005/000014 patent/WO2005066082A1/de active Application Filing
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