Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G9/00—Compounds of zinc
  • C01G9/04—Halides
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G9/00—Compounds of zinc
  • C01G9/006—Compounds containing zinc, with or without oxygen or hydrogen, and containing two or more other elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
  • B23K35/36—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest
  • B23K35/3601—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest with inorganic compounds as principal constituents
  • B23K35/3603—Halide salts
  • B23K35/3605—Fluorides
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
  • C01D3/00—Halides of sodium, potassium or alkali metals in general
  • C01D3/02—Fluorides
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer

Definitions

• the invention relates to a process for the preparation of alkali metal fluorozudie, the product obtained and its use.
• Alkali metal fluorozelleses such as cesium fluorozoniae and especially potassium fluorozoniae can be used as fluxes for soldering aluminum components and components made of aluminum alloys. These compounds not only act as fluxes, they also cause the surface to be coated by depositing zinc on the surface of the components.
• the fluorozineses can also be used together with alkali fluoroaluminates, for example potassium fluoroaluminate and / or cesium fluoroaluminate. These compounds also act as fluxes in aluminum brazing.
• the German patent application DE 199 13 111 AI discloses such fluxes and their application.
• Alkali metal fluorozineses according to that published patent are produced by melting alkali metal fluoride and zinc fluoride, reacting alkali metal fluoride and zinc fluoride in the aqueous phase or reacting zinc oxide with adducts of hydrogen fluoride and alkali metal fluoride.
• the object of the present invention is to provide a method for producing alkali metal fluorozineses with which products with defined grain size distribution ranges can be achieved. It is also an object of the present invention to provide an alkali metal fluorozudie which is suitable particularly well suited as a flux or flux component. This object is achieved by the product according to the invention and the corresponding manufacturing process.
• the invention is based on the knowledge that alkali metal fluorozinese with certain properties with respect to the grain size can be produced depending on the type of the starting compounds and the order in which they are contacted with one another.
• the process according to the invention for producing alkali metal fluorozinese from alkali metal hydroxide, zinc oxide and alkali metal fluoride or hydrogen fluoride in the aqueous phase is characterized in that
• zinc oxide instead of zinc oxide, other zinc compounds such as zinc hydroxide, zinc carbonate or zinc chloride can be used, zinc oxide is preferred.
• finely divided denotes an alkali metal fluorozudie in which 50% of the particles have a grain size of less than 5 ⁇ m and 90% of the particles have a grain size of less than 9 ⁇ m; the remaining particles are then equal to or larger than the specified values. It is preferred to prepare finely divided alkali tallfluorozudie, in which 50% of all particles have a diameter of ⁇ 3.8 ⁇ m and 90% of all particles have a diameter of ⁇ 8 ⁇ m. The size is determined by means of laser diffraction.
• the term “medium-fine” means that 50% of the particles of the material produced have a grain size of less than 11 ⁇ m and 90% have a grain size of less than 27 ⁇ m. The remaining particles are at or above the values mentioned.
• the term preferably means that 50% of all particles produced have a grain size of less than 10 ⁇ m and 90% of all particles have a grain size of less than 26 ⁇ m.
• the particle analysis is again determined according to the principle of laser diffraction.
• the term “coarsely divided” means that 50% of all particles have a grain size of less than 22 ⁇ m and 90% have a grain size of less than 40 ⁇ m.
• the term “coarse” preferably means that 50% of all particles have a grain size of less than 21 ⁇ m and 90% have a grain size of less than 39 ⁇ m. The remaining particles correspond to the specified size or are larger.
• Alkali metal hydroxide, hydrogen fluoride and alkali metal fluoride are advantageously used in the form of an aqueous solution.
• the preferred alkali metal is potassium hydroxide.
• finely divided alkali metal fluorozinese is formed.
• the finely divided alkali metal fluorozellese is then preferably separated off and dried.
• the product obtained is more finely divided than that product which is obtained by the processes described in German Offenlegungsschrift 199 13 111.
• alkali metal fluorozellese can be produced in this way, which has a grain spectrum, in which 50% of all particles have a diameter of ⁇ 5 ⁇ m (measured by laser diffraction).
• potassium hydroxide As the alkali hydroxide and to produce potassium fluorozinese.
• the potassium hydroxide is preferably used in the form of an aqueous potassium hydroxide solution.
• concentration of KOH in this potassium hydroxide solution is advantageously in the range from 10 to 50% by weight.
• KZnF 3 is particularly preferably produced.
• potassium hydroxide, zinc oxide and hydrogen fluoride are preferably used in amounts such that the atomic ratio of K: Zn is in the range of 1: 1 ⁇ 0.05 and the atomic ratio of (K + Zn): F is in the range of 1: 3 ⁇ 0.05.
• the zinc oxide can also be used as a precursor, e.g. B. as ZnC0 3 or ZnCl 2 used.
• a suspension is formed, which is then further mixed with hydrogen fluoride to the desired alkali metal fluorozinese.
• a hydrofluoric acid with 10 to 99% by weight HF is preferably used, preferably 20 to 40% by weight HF.
• the suspension of alkali metal hydroxide and zinc oxide is preferably produced at a temperature in the range from 15 to 85 ° C., in particular at ambient temperature (approx. 20 ° C.).
• the reaction of the intermediate formed with hydrogen fluoride is advantageously carried out at a temperature in the range from about 20 ° C. to 90 ° C.
• medium-fine alkali metal fluorozinese is produced.
• Hydrogen fluoride and alkali hydroxide are preferably used as an aqueous solution.
• the preferred concentrations correspond to those of the first variant.
• Alkali is preferably potassium.
• Hydrogen fluoride and zinc oxide, which as a precursor in the form of z. B. zinc carbonate can be used in the temperature range of 20 (ambient temperature) to 95 ° C, the subsequent reaction with hydroxide is preferably carried out at a temperature in the range of 70 to 90 ° C.
• hydrogen fluoride is first reacted with zinc oxide and then alkali metal fluoride is added.
• alkali is preferably potassium.
• Hydrogen fluoride is preferably used in aqueous solution, the preferred concentration is as in the first variant.
• the alkali metal fluoride is also preferably used in aqueous solution.
• the preferred concentration is in the range from 25 to 40% by weight, in particular 28 to 32% by weight.
• the temperature of the first reaction stage is in the same range as in variant 1 and variant 2.
• the addition of alkali metal fluoride is then preferably carried out at a temperature of 70 to 90 ° C.
• Another object of the invention is the fine, medium-fine or coarse-particle alkali metal fluorozinese obtainable according to the variants of the method according to the invention with the parameters given above with respect to the grain size.
• Potassium fluorozudie in particular of the formula KZnF 3, is preferred.
• the grain sizes of the fine product - based on 50% of the particles, d x50 - are in the range from 3 to 5 ⁇ m, the medium-fine product in the range from 6 to 11 ⁇ m and the coarse-particle product in the range from 12 to 25 ⁇ m.
• B. Potassium luorzinkat can be produced with an even finer grain spectrum (for example, 50% of the particles have a diameter of less than 3.3 microns).
• mixed fluorozineses are also the subject of the invention.
• potassium cesium fluorozinese (the ratio of potassium to cesium is arbitrary) is preferred.
• the fluorozineses according to the invention are particularly suitable for use as fluxes when soldering aluminum and aluminum alloys. They are then used in a known manner, as disclosed, for example, in German Offenlegungsschrift 199 13 111.
• the fine-particle product is particularly suitable for application by wet fluxing, the coarse-particle product for dry fluxing.
• the medium-fine product works well for both purposes. Of course, one can also produce mixtures with predetermined properties.
• soldering flux additives to other fluxes, in particular as a flux additive to potassium fluoroaluminate and cesium fluoroaluminate.
• alkali metal fluorozinese according to the invention can of course also be mixed with alkali metal fluorozinese produced in a conventional manner in order to influence properties such as suspendability or fluidizability.
• solder metal or with a precursor for the solder metal, for example with 5-95% by weight, based on the total flux, of alkali metal fluorosilicate such as potassium hexafluorosilicate, see EP-A 810 057 and DE-OS 196 36 897, or with 10 to 80% by weight with copper, zinc or germanium, which form a eutectic with aluminum, see US Pat. No. 5,190,596.
• alkali metal fluorate e.g. B. with KA1F 4 or K 2 AIF 5 , as described analogously in DE-OS 199 13 111, or with cesium fluoroaluminate.
• the latter is favorable for Al alloys with a larger Mg content.
• auxiliaries may be included, e.g. B. as described in DE-OS 199 13 111, page 3.
• binders or dispersing agents can be included.
• the flux can be applied in a known manner to the components to be connected made of aluminum or aluminum alloys. Dry application based on electrostatic spray technology is possible due to the good fluidization properties of the flux.
• the flux can be applied to the materials to be joined in the form of aqueous or organic suspensions or as a paste.
• Aqueous or organic slurries advantageously contain 15 to 75% by weight of the flux.
• suspensions of the flux in organic liquids, expediently the substances usually used as organic solvents, such as alcohols, in particular methanol, ethanol, propanol or isopropanol, and polyols.
• organic liquids are ethers, e.g. B. diethylene glycol onobutyl ether, ketones such as acetone, esters of alcohols, diols or polyols.
• Binder for use as a paste is e.g. B. ethyl cellulose.
• film formers usually polymers, which are in organic solvents, e.g. B.
• acetone are soluble, flux with optionally solder or solder precursor can be applied to the workpiece and result in a firmly adhering film after evaporation of the solvent.
• Suitable polymers are e.g. B. (meth) acrylates. The film former then evaporates during soldering.
• the solder metal when used, can be contained in the flux (as an admixed powder), it can already be applied as a plating to the components to be soldered, or it can be applied in addition to the flux.
• a soldering temperature of 600 ° C is generally sufficient. Soldering is preferably carried out at 390 ° C. to 600 ° C., in particular at 420 ° to 590 ° C. There is ambient pressure. Soldering, e.g. B. in a vacuum, with evaporation of the flux, as described in JP-A 03/099795, is also possible. Flame or furnace soldering can be used, especially in an inert atmosphere (e.g. N 2 atmosphere).
• an inert atmosphere e.g. N 2 atmosphere
• Demineralized water (demineralized water) 30.6 ml
• batch 1 is prepared by reacting HF solution with zinc oxide
• batch 2 is the KOH solution.
• batch 1 is prepared by reacting HF solution with zinc oxide
• batch 2 is a solution of KF in water.
• Grain size x 50 20.50 ⁇ m
• Grain size x 90 38.18 ⁇ m

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Catalysts (AREA)
• Inorganic Compounds Of Heavy Metals (AREA)
• Nonmetallic Welding Materials (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Priority Applications (7)

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Related Child Applications (1)

Publications (1)

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Cited By (3)

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Citations (2)

Family Cites Families (9)

• 2000
  • 2000-04-03 DE DE10016257A patent/DE10016257A1/de not_active Withdrawn
• 2001
  • 2001-03-28 CZ CZ20023281A patent/CZ20023281A3/cs unknown
  • 2001-03-28 WO PCT/EP2001/003509 patent/WO2001074715A1/de not_active Ceased
  • 2001-03-28 JP JP2001572414A patent/JP4938196B2/ja not_active Expired - Fee Related
  • 2001-03-28 EP EP01938061A patent/EP1272429B1/de not_active Expired - Lifetime
  • 2001-03-28 KR KR1020027012725A patent/KR100753524B1/ko not_active Expired - Fee Related
  • 2001-03-28 DE DE50115516T patent/DE50115516D1/de not_active Expired - Lifetime
  • 2001-03-28 AU AU2001263821A patent/AU2001263821A1/en not_active Abandoned
  • 2001-03-28 BR BR0109781-4A patent/BR0109781A/pt not_active Application Discontinuation
• 2002
  • 2002-10-02 US US10/262,612 patent/US6743409B2/en not_active Expired - Lifetime
• 2003
  • 2003-12-31 US US10/747,956 patent/US20040151655A1/en not_active Abandoned

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