DE102006060974A1 - Preparing amorphous cesium fluoro aluminate complex, useful as fluxing agent, comprises bonding cesium fluoride on aluminum fluoride and adjusting to desired amorphous character with additive; adjusting basicity or acidity of end product - Google Patents

Abstract

Preparing an amorphous cesium fluoro aluminates (CsAlF) complex, comprises (a) bonding the cesium fluoride dissolved in water on the aluminum fluoride as solid substance and adjusting to desired amorphous character by adding acid and/or alkaline compounds as additives; (b) adjusting the desired basicity or acidity of the end product by adding acidic or basic compounds as additives; (c) applying strong vacuum after completing the reaction to evaporate the water in the reactor quickly; and (d) draining the product at increased temperature and at lower vacuum. An independent claim is included for an amorphous CsAlF complex obtained by the method.

Description

object The present invention is an amorphous cesium aluminum fluoride complex, a process for its production and the use of the complex as a flux, especially for soft soldering of aluminum.

It is known, cesium fluoroaluminates as a flux for soldering of aluminum materials. The low melting point and thus the ability also to solder magnesium-containing aluminum alloys, make many applications and developments are possible. In the automotive industry, for example, the trend was in In recent years, smaller and smaller coolers have been operating at ever higher pressures become. This increased the demands on the strength of the Cooler, resulting in a higher one Content of magnesium in the aluminum alloys reflected. These Development also caused higher Requirements for the flux. To meet these requirements it must be possible to tailor a flux specifically to the application. A crucial requirement is the melting point of a Flux over to be able to adjust a wide range and, above all, one allow low melting point or melting below 440 ° C. The flux should be stable, for example against oxidation, and process themselves into pastes and soldering rods to let.

was standing In the art are fluxes of crystalline complexes of cesium / aluminum / fluorine (Cs / Al / F), so-called cesium fluoroaluminates. A disadvantage of these crystalline substances for use as flux is that these defined compounds with narrow melting ranges or even exact melting points. In addition, additional substances, for example Additives with which the basicity or acidity can be adjusted and that influence the soldering behavior positively, not bound to the crystalline complex.

US-A-4689092 discloses a flux consisting of a cesium fluoroaluminate complex which with the appropriate ratio of cesium fluoride (CsF) to aluminum fluoride (AlF ₃₎ starts to melt at 440 ° C. The material shows strong crystallinity in the X-ray diffractogram and is not hygroscopic. The material can be easily hydrothermally produced from cesium fluoride and aluminum fluoride. However, melting points below 440 ° C can not be achieved, but only melting points in the range of 440 to 460 ° C can be set. Furthermore, the flux shows no good properties in the soldering of materials whose magnesium content is greater than 1%. In addition, this flux is not suitable for flame soldering because of its easy oxidizability and fast degradation (US-A-5171377).

US-A-4923530 describes the preparation of an oxygen-containing suspension of cesium fluoroaluminate which has good stability and a low melting point of 414 ° C. However, hydrofluoric acid is used at temperatures up to 90 ° C for the production. Dealing with highly toxic hydrofluoric acid under these conditions requires special requirements for materials and occupational safety. The use of cesium carbonate (Cs ₂ CO ₃ ) produces CO ₂ during the reaction, which forms hydrofluoric acid and fluoride aerosols. In addition, this method aims at producing a suspension. However, this is not suitable for the production of soldering rods or anhydrous pastes. This requires a dry powder.

US-A-5171377 describes the preparation of a cesium fluoride flux, Aluminum fluoride and crystalline aluminum hydroxide or alumina. The complex formed leaves a wide melting range and is for soldering magnesium-containing aluminum alloys suitable. However, it can not reach melting below 440 ° C become. Through the use of aluminum hydroxide or aluminum oxide as additives can be no acidity be achieved in the flux. The acidity of the flux affects the Oxidation of the flux contrary.

EP-A-0785045 describes the preparation of a flux consisting of a cesium fluoroaluminate reaction product having different ratios of CsF to AlF ₃ . Depending on the ratio of CsF to AlF _3, this flux can reach melting points below 440 ° C down to 427 ° C. However, the flux has distinct melting points, indicating that it is a crystalline substance.

The Fluxes known from the prior art thus correspond not the requirements described above. In particular, describes the prior art no amorphous Cäsiumfluoroaluminate as a flux.

task The present invention is therefore a flux on the Basis of a cesium fluoroaluminate which can be obtained as a dry powder, in which a start of melting is set below 440 ° C, the position and Above all, the width of the melting range varies and its acidity or basicity by Additives can be adjusted. Under the onset of melting is here to understand the lower end of the melting range. Under melting range is the temperature range to be understood from the first melting on to the utter liquefaction of the substance is enough.

According to the invention this Problem surprisingly through an amorphous cesium aluminum fluoride complex solved, which can be produced according to one or more of claims 1 to 25. Preferred embodiments can be found in the subclaims. there According to the invention, a cesium aluminum fluoride complex, CsAlF complex for short, is provided, the over a larger temperature range melts, i. has a wide melting range. This is possible because the complex according to the invention amorphous, i. is not crystalline. For amorphous solids are the molecular building blocks not in crystal lattices, but randomly arranged. As a result, amorphous solids have no sharp melting point, but a more or less wide melting range.

An elemental analysis of the amorphous CsAlF complex essentially gives the following composition (in% by weight):
Cs: 45-65
Al: 5-15
Q: 20-40

It is known that aluminum fluoride forms complex salts with metal fluorides, for example cesium fluoride. These complex salts are composed of AlF ₆ octahedra. These octahedra group depending on the size and number of metal ions present to different packages. The crystals of the compounds are formed: CsAlF ₄ , Cs ₂ AlF ₅ , Cs ₃ AlF ₆ . These then show the typical properties of crystalline compounds.

By skillful reaction is prevented according to the invention that it comes to this aggregation and compounding, so that an amorphous cesium aluminum fluoride complex arises.

To has as a suitable reactor, a known vacuum disc dryer proved. This is the implementation of several process steps possible in succession; Advantageously, all process steps of the manufacturing process carried out in a vacuum mixing dryer. As starting materials are a cesium fluoride solution and Aluminum fluoride used. Below is the implementation of the Process steps described by way of example, without the invention thereby restrict:

Process step 1:

• 1. die Reaktionszeit steuern,
• 2. die Amorphizität des Produkts einstellen,
• 3. die Farbe des Produkts von rotbraun bis hellweiß verändern,
• 4. die Eigenschaften des Produkts bei der Pastenherstellung vorgeben,
• 5. die Eignung für unterschiedliche Lötprozesse erreichen.

Cesium fluoride dissolved in water is bound to the solid aluminum fluoride. In this case, the product properties can be controlled during the reaction by adding additives. As has been shown, can be by the addition of alkaline or acidic compounds:

• 1. control the reaction time,
• 2. adjust the amorphicity of the product,
• 3. change the color of the product from reddish brown to light white,
• 4. specify the properties of the product in the paste production,
• 5. Achieve the suitability for different soldering processes.

The Temperature is between 95 and 175 ° C, preferably between 105 and 150 ° C. The pressure is between 0.4 and 2.5 bar absolute, preferably between 0.9 and 2.0 absolutely bar. The reaction time is between 15 minutes and 6 hours, preferably between 30 minutes and 5 hours.

The educts CsF and AlF ₃ are used in the molar ratio of CsF to AlF ₃ between 0.9: 1 and 3.0: 1, preferably in a molar ratio of between 1: 1 and 1.5: 1. In order to direct the reaction, it is possible to use additives such as CsHCO ₃ , Cs ₂ CO ₃ , CsOH, dilute hydrofluoric acid or cesium bifluoride, preferably dilute hydrofluoric acid or CsOH. These substances can be used individually or as a mixture. The amount of additive used is based on the used AlF ₃ . The molar ratio of additive to AlF ₃ is between 0.001: 1 and 0.2: 1, preferably between 0.008: 1 and 0.1: 1.

Process step 2:

Towards the end of the reaction time of process step 1, the desired basicity or acidity in the end product can be set by adding acidic or alkaline compounds. For this purpose, the above-mentioned additives CsHCO ₃ , Cs ₂ CO ₃ , CsOH, dilute hydrofluoric acid or cesium bifluoride are used, preferably dilute hydrofluoric acid or CsOH. The amount of additive used is based on the used AlF ₃ . The molar ratio of additive to AlF ₃ is between 0.0001: 1 and 0.3: 1, preferably between 0.01: 1 and 0.11: 1. The ranges of temperature and pressure correspond to those of method step 1.

Process step 3:

After completion of the reaction in process step 2, the water present in the reactor is evaporated very rapidly by applying strong vacuum in order, on the one hand, to maintain the amorphicity of the product as far as possible, and on the other hand to prevent unwanted by-products from forming. The reaction suspension turns into a solid. The pressure is lowered to values between 10 and 100 mbar, preferably between 20 and 40 mbar absolute. The time in which the water is evaporated to obtain the solid, is between 5 minutes and one hour, preferably between 15 and 30 minutes.

Process step 4:

If the solid is at elevated temperatures and lower Vacuum the product as far as desired dehydrated. It is thus possible, residual moisture of less than 0.1%. The temperature is to between 80 and 300 ° C, preferably between 100 and 180 ° C. The pressure is to be between 10 and 900 mbar, preferably between 20 and 100 mbar. This will eventually formed crystalline hydrates, the the amorphicity reduce the product, destroyed again. Instead of vacuum can for example, towing gas for the removal of moisture be used.

The Manufacturing process can also be used in other reactors than a vacuum mixing dryer carried out become. For Process steps 1 and 2 can be, for example also mixed reactors, kneaders or similar apparatus used become. For Step 3 can All dryers are used which allow quick drying allow, for example spray dryer, Belt dryers, fluidized bed dryers and similar aggregates. For process step 4 can all drying apparatus are used in which at elevated temperature, i.e. above 80 ° C, can be dried, for example, drying cabinets or Rotary kilns.

The inventive manufacturing method offers across from the prior art significant advantages, firstly with respect to the Options, to adjust the product characteristics, on the other hand with regard to work safety and equipment costs, preferably if that Process in only one reactor, particularly preferably only in one Vacuum mixing dryer performed becomes.

The process according to the invention makes it possible to prepare an amorphous CsAlF complex. This complex contains X-ray diffractometry only traces of crystalline CsAlF ₄ or Cs ₂ AlF ₅ × H ₂ O. The starting material CsF can not be detected in the product, AlF ₃ only in small amounts.

The melting range of the complex can be adjusted according to the invention by carrying out the reaction and varying the ratio of CsF to AlF ₃ . It can be set to a melting below 420 ° C. The product is hygroscopic and slowly absorbs moisture from the air.

These Advantages over The prior art allows the CsAlF complex according to the invention diverse use. Because of the variety of different soldering applications it is necessary, according to the individual soldering processes to provide specific suitable fluxes. With the present Invention it is possible to produce a wide variety of products.

• 1. bei der Herstellung von Fülldrähten das Flussmittel durch das Lot von der Umgebung abgeschirmt werden;
• 2. durch Aufpressen des Flussmittels eine geringe Oberfläche erreicht und damit die Feuchtigkeitsaufnahme verringert werden,
• 3. mit Hilfe von organischen Flüssigkeiten zur Herstellung von Suspensionen die Feuchtigkeitsaufnahme unterbunden werden.

The possibly disturbing hygroscopicity of the complexes according to the invention can optionally be compensated by measures during processing:
For example:

• 1. in the manufacture of cored wires, the flux is shielded from the environment by the solder;
• 2. achieved by pressing the flux a small surface and thus the moisture absorption can be reduced,
• 3. With the help of organic liquids for the production of suspensions the moisture absorption can be prevented.

• – ein Verfahren zur Herstellung eines amorphen CsAlF-Komplexes, das durch folgende Verfahrensschritte gekennzeichnet ist:
• a) Bindung des in Wasser gelösten Cäsiumfluorid an das als Feststoff vorliegende Aluminiumfluorid und Einstellen der gewünschten Amorphizität durch Zugabe von sauren bzw. alkalischen Verbindungen als Additive,
• b) Einstellen der gewünschten Basizität bzw. Acidität im Endprodukt durch Zugabe von sauren bzw. alkalischen Verbindungen als Additive,
• c) Anlegen von starkem Vakuum nach Beendigung der Reaktion, um sehr schnell das im Reaktor vorhandene Wasser zu verdampfen,
• d) Entwässerung des Produktes bei erhöhten Temperaturen und niedrigerem Vakuum, dabei ist bevorzugt:
• – im Verfahrensschritt a) eine Reaktionszeit zwischen 15 Minuten und 6 Stunden, bevorzugt zwischen 30 Minuten und 5 Stunden,
• – im Verfahrensschritt a) und/oder b) die Zugabe von Additiven zur Steuerung von Produkteigenschaften,
• – im Verfahrensschritt a) und/oder b) die Zugabe von sauren bzw. alkalischen Verbindungen als Additive zum Einstellen der gewünschten Basizität bzw. Acidität im Endprodukt,
• – im Verfahrensschritt a) die Zugabe von sauren bzw. alkalischen Verbindungen als Additive zum Einstellen der Amorphizität im Endprodukt,
• – im Verfahrensschritt a) und/oder b) die Zugabe der Additive CsHCO₃, Cs₂CO₃, CsOH, verdünnte Flusssäure oder Cäsiumbifluorid, besonders bevorzugt verdünnte Flusssäure oder CsOH,
• – im Verfahrensschritt a) und/oder b) ein molares Verhältnis von Additiv zu AlF₃ zwischen 0,0001:1 und 0,3:1, besonders bevorzugt zwischen 0,008:1 und 0,11:1,
• – in den Verfahrensschritten a) und b) eine Temperatur zwischen 95 und 175°C, besonders bevorzugt zwischen 105 und 150°C,
• – in den Verfahrensschritten a) und b) ein Druck zwischen 0,4 und 2,5 bar absolut, besonders bevorzugt zwischen 0,9 und 2,0 bar absolut,
• – im Verfahrensschritt c) das Anlegen von starkem Vakuum nach Beendigung der Reaktion, um das im Reaktor vorhandene Wasser sehr schnell zu verdampfen,
• – im Verfahrensschritt c) die Erniedrigung des Druckes auf Werte zwischen 10 und 100 mbar absolut, besonders bevorzugt zwischen 20 und 40 mbar absolut,
• – im Verfahrensschritt c) der Übergang der Reaktionssuspension in einen Feststoff,
• – im Verfahrensschritt c) eine Zeit zwischen 5 Minuten und einer Stunde, besonders bevorzugt zwischen 15 und 30 Minuten beträgt, in der das Wasser verdampft wird, um den Feststoff zu erhalten,
• – im Verfahrensschritt d) eine erhöhte Temperatur und ein niedrigeres Vakuum, um das Produkt so weit wie gewünscht zu entwässern,
• – im Verfahrensschritt d) das Erreichen von Restfeuchten von unter 0,1 %,
• – im Verfahrensschritt d) eine Temperatur zwischen 80 und 300°C, besonders bevorzugt zwischen 100 und 180°C zum Erreichen von Restfeuchten von unter 0,1 %,
• – im Verfahrensschritt d) ein Druck zwischen 10 und 900 mbar sein, besonders bevorzugt zwischen 20 und 100 mbar,
• – im Verfahrensschritt d) der Einsatz von Schleppgas zum Abtransport der Feuchtigkeit an Stelle von Vakuum;
• – ein Verfahren zur Herstellung eines amorphen CsAlF-Komplexes, wobei das Verfahren ausschließlich in ein und demselben Reaktor, bevorzugt in einem Vakuummischtrockner durchgeführt wird;
• – ein Verfahren zur Herstellung eines amorphen CsAlF-Komplexes, wobei die Verfahrensschritte a) und b) in Mischreaktoren und/oder Knetern durchgeführt werden;
• – ein Verfahren zur Herstellung eines amorphen CsAlF-Komplexes, wobei Verfahrensschritt c) in einem Trockenapparat durchgeführt wird, der eine schnelle Trocknung ermöglicht;
• – ein Verfahren zur Herstellung eines amorphen CsAlF-Komplexes, wobei Verfahrensschritt c) in einem Sprühtrockner, Bandtrockner oder Wirbelschichttrockner durchgeführt wird;
• – ein Verfahren zur Herstellung eines amorphen CsAlF-Komplexes, wobei Verfahrensschritt d) in einem Trockenapparat durchgeführt wird, in dem oberhalb von 80°C getrocknet werden kann;
• – ein Verfahren zur Herstellung eines amorphen CsAlF-Komplexes, wobei Verfahrensschritt d) in einem Trockenschrank oder Drehrohrofen durchgeführt wird;
• – ein Cäsiumalumiumfluorid-Komplex, der amorph ist, erhältlich nach einem der erfindungsgemäßen Verfahren;
• – ein amorpher CsAlF-Komplex mit einem Schmelzbeginn unterhalb von 440°C, bevorzugt unterhalb von 430°C, besonders bevorzugt unterhalb von 420°C;
• – ein amorpher CsAlF-Komplex mit einer Breite des Schmelzbereiches von mindestens 30°C, bevorzugt von mindestens 50°C, besonders bevorzugt von mindestens 60°C;
• – ein amorpher CsAlF-Komplex mit einer Breite des Schmelzbereiches von 30 bis 90°C, bevorzugt von 30 bis 80°C, besonders bevorzugt von 30 bis 70°C;
• – ein amorpher CsAlF-Komplex mit einem Schmelzbereich zwischen 400 und 500°C, bevorzugt zwischen 410 und 490°C, besonders bevorzugt zwischen 415 und 480°C;
• – ein amorpher CsAlF-Komplex, der 45 bis 65 Gew.-%, bevorzugt 50 bis 60 Gew.-%, besonders bevorzugt 55 bis 60 Gew.-% Cäsium, 5 bis 15 Gew.-%, bevorzugt 7 bis 13 Gew.-%, besonders bevorzugt 8 bis 12 Gew.-% Aluminium und 20 bis 40 Gew.-%, bevorzugt 25 bis 35 Gew.-%, besonders bevorzugt 27 bis 33 Gew.-% Fluor enthält;
• – die Verwendung eines amorphen CsAlF-Komplexes als Flussmittel zum Weichlöten von Aluminium.

The subject of the invention is in detail:

• A process for the preparation of an amorphous CsAlF complex characterized by the following process steps:
• a) binding of the cesium fluoride dissolved in water to the solid aluminum fluoride and setting the desired amorphicity by addition of acidic or alkaline compounds as additives,
• b) setting the desired basicity or acidity in the end product by adding acidic or alkaline compounds as additives,
• c) applying a strong vacuum after completion of the reaction in order to rapidly evaporate the water present in the reactor,
• d) dehydration of the product at elevated temperatures and lower vacuum, preference being given to:
• In process step a) a reaction time of between 15 minutes and 6 hours, preferably between 30 minutes and 5 hours,
• In process step a) and / or b) the addition of additives for controlling product properties,
• In process step a) and / or b) the addition of acidic or alkaline compounds as additives for adjusting the desired basicity or acidity in the end product,
• In process step a) the addition of acidic or alkaline compounds as additives for adjusting the amorphicity in the end product,
• In process step a) and / or b) the addition of the additives CsHCO ₃ , Cs ₂ CO ₃ , CsOH, dilute hydrofluoric acid or cesium bifluoride, particularly preferably dilute hydrofluoric acid or CsOH,
• In process step a) and / or b) a molar ratio of additive to AlF _{3 of} between 0.0001: 1 and 0.3: 1, more preferably between 0.008: 1 and 0.11: 1,
• - In the process steps a) and b) a temperature between 95 and 175 ° C, especially be preferably between 105 and 150 ° C,
• In the process steps a) and b), a pressure between 0.4 and 2.5 bar absolute, more preferably between 0.9 and 2.0 bar absolute,
• In step c) the application of strong vacuum after completion of the reaction in order to evaporate the water present in the reactor very quickly,
• In method step c), the reduction of the pressure to values between 10 and 100 mbar absolute, more preferably between 20 and 40 mbar absolute,
• In process step c), the transition of the reaction suspension into a solid,
• In process step c) is a time between 5 minutes and one hour, more preferably between 15 and 30 minutes, in which the water is evaporated to obtain the solid,
• In process step d) an elevated temperature and a lower vacuum in order to dewater the product as much as desired,
• In process step d) the achievement of residual moisture of less than 0.1%,
• In process step d) a temperature of between 80 and 300 ° C., more preferably between 100 and 180 ° C., to achieve residual moisture of less than 0.1%,
• In process step d), a pressure between 10 and 900 mbar, more preferably between 20 and 100 mbar,
• - In process step d) the use of towing gas to remove moisture in place of vacuum;
• A process for the preparation of an amorphous CsAlF complex, the process being carried out exclusively in one and the same reactor, preferably in a vacuum mixing dryer;
• A process for preparing an amorphous CsAlF complex, wherein process steps a) and b) are carried out in mixing reactors and / or kneaders;
• A process for producing an amorphous CsAlF complex, wherein process step c) is carried out in a drying apparatus which enables rapid drying;
• A process for producing an amorphous CsAlF complex, wherein process step c) is carried out in a spray dryer, belt dryer or fluidized bed dryer;
• A process for producing an amorphous CsAlF complex, wherein process step d) is carried out in a drying apparatus in which it can be dried above 80 ° C;
• A process for producing an amorphous CsAlF complex, wherein process step d) is carried out in a drying oven or rotary kiln;
• A cesium aluminum fluoride complex which is amorphous, obtainable by one of the processes according to the invention;
• An amorphous CsAlF complex having a melting beginning below 440 ° C, preferably below 430 ° C, more preferably below 420 ° C;
• An amorphous CsAlF complex having a melting range of at least 30 ° C, preferably of at least 50 ° C, more preferably of at least 60 ° C;
• An amorphous CsAlF complex having a melting range of from 30 to 90 ° C, preferably from 30 to 80 ° C, more preferably from 30 to 70 ° C;
• An amorphous CsAlF complex having a melting range between 400 and 500 ° C, preferably between 410 and 490 ° C, more preferably between 415 and 480 ° C;
• An amorphous CsAlF complex containing 45 to 65 wt.%, Preferably 50 to 60 wt.%, Particularly preferably 55 to 60 wt.% Cesium, 5 to 15 wt.%, Preferably 7 to 13 wt. -%, particularly preferably 8 to 12 wt .-% aluminum and 20 to 40 wt .-%, preferably 25 to 35 wt .-%, particularly preferably 27 to 33 wt .-% fluorine;
• The use of an amorphous CsAlF complex as a flux for soldering aluminum.

The Invention will be explained in more detail below by several embodiments, without to restrict it to:

Example 1: CsAlF complex with a narrow melting range

Process step a: 81 kg of an aqueous 71.4% strength cesium fluoride solution are introduced into a vacuum mixing dryer with vapor condenser and vacuum system and 21 kg of AlF _{3 are} added. It is stirred under normal conditions until a homogeneous suspension is formed. Then 50 kg of 0.2% hydrofluoric acid are added as an additive to the suspension. It is heated under stirring at atmospheric pressure to boiling and boiled under reflux for 4.5 hours.

step b: The boiling suspension is 5 kg of a 0.1% cesium hydroxide solution as Added additive. From the suspension will be within one Hour 80 kg of water evaporated. The vapor is condensed and the Volume used to determine the end point of evaporation.

Process step c: Vacuum is applied. Within 5 minutes, a residual pressure of 200 mbar is reached. The remaining water evaporates very quickly. After 30 minutes, the porridge becomes a free-flowing powder. The residual pressure is at End 35 mbar.

step d: Then stir and dried to maximum vacuum. This is a product temperature of 160 ° C reached. The drying process is stopped after 12 hours and the powder on Cooled to 30 ° C and deducted.

The CsAlF complex obtained has a pH of 6.9, a residual moisture content of 0.8% and a melting interval: onset = 474 ° C, end = 478 ° C. 1 : DSC (differential scanning calometry).

Example 2: CsAlF complex with a wide melting range

Process Step a: 76 kg of an aqueous 75.9% cesium fluoride solution are introduced into a vacuum mixing dryer with planetary stirrer, vapor condenser and vacuum system, and 22 kg of AlF _{3 are} added. It is stirred under normal conditions until a homogeneous suspension is formed. Then 0.9 kg of cesium carbonate are added as an additive to the suspension. It is heated with stirring under atmospheric pressure to boiling and boiled under reflux for one hour.

step b: 5 kg of 0.1% hydrofluoric acid are added to the boiling suspension. The suspension is heated to boiling under atmospheric pressure.

step c: Vacuum is applied. The pressure drops continuously up 50 mbar. After one hour, so much water has evaporated that one dry powder is present. The residual pressure is 20 mbar at the end.

step d: Then stir and maximum vacuum further dried. This is a product temperature from 180 ° C reached. The drying process is finished after 8 hours and the Powder at 40 ° C chilled and deducted.

The obtained CsAlF complex has a pH of 6.6, a residual moisture of 0.1% and a melting interval with multiple peaks of 419-472 ° C; 2 : DSC.

Claims (32)

Process for the preparation of an amorphous CsAlF complex, which is characterized by the following method steps: a) Binding of dissolved in water Cesium fluoride the solid aluminum fluoride and adjusting the desired amorphousness by adding acidic or alkaline compounds as additives; b) Setting the desired basicity or acidity in the End product by adding acidic or alkaline compounds as additives; c) application of strong vacuum after completion of the Reaction to evaporate very quickly the water present in the reactor; d) drainage of the product at elevated Temperatures and lower vacuum. Method according to claim 2, characterized in that that while the process steps a) and b) the temperature between 95 and 175 ° C, preferred between 105 and 150 ° C is. Method according to claim 1 or 2, characterized that while the process step a) and b) the pressure between 0.4 and 2.5 bar absolute, preferably between 0.9 and 2.0 bar absolute. Method according to at least one of claims 1 to 3, characterized in that during method step a) the reaction time is between 15 minutes and 6 hours, preferably between 30 minutes and 5 hours. Method according to at least one of claims 1 to 4, characterized in that during method step a) and / or b) the product properties by adding additives can be controlled. Method according to at least one of claims 1 to 5, characterized in that during method step a) by adding acidic or alkaline compounds as additives the desired amorphousness can be adjusted in the final product. Method according to at least one of claims 1 to 6, characterized in that during method step a) and / or b) by adding acidic or alkaline compounds as additives the desired basicity or acidity can be adjusted in the final product. Process according to at least one of Claims 1 to 7, characterized in that the additives CsHCO ₃ , Cs ₂ CO ₃ , CsOH, dilute hydrofluoric acid or cesium bifluoride, preferably dilute hydrofluoric acid or CsOH, are used during process step a) and / or b). Method according to at least one of claims 1 to 8, characterized in that the molar ratio of additive to AlF _{3 is} between 0.0001: 1 and 0.3: 1, preferably between 0.008: 1 and 0.11: 1. Method according to at least one of claims 1 to 9, characterized in that during process step c) after completion of the reac tion by applying strong vacuum very quickly the water present in the reactor is evaporated. Method according to at least one of claims 1 to 10, characterized in that during process step c) the pressure to values between 10 and 100 mbar, preferably between 20 and 40 mbar absolute is lowered. Method according to at least one of claims 1 to 11, characterized in that during method step c) the reaction suspension turns into a solid. Method according to at least one of claims 1 to 12, characterized in that during method step c) the time in which the water is evaporated to the solid obtained, between 5 minutes and one hour, preferably between 15 and 30 minutes. Method according to at least one of claims 1 to 13, characterized in that during process step d) at elevated Temperatures and lower vacuum the product is dewatered as much as desired. Method according to at least one of claims 1 to 14, characterized in that during process step d) Residual moisture of less than 0.1% can be achieved. Method according to at least one of claims 1 to 15, characterized in that during process step d) the temperature is between 80 and 300 ° C, preferably between 100 and 180 ° C. Method according to at least one of claims 1 to 16, characterized in that during process step d) the pressure should be between 10 and 900 mbar, preferably between 20 and 100 mbar. Method according to at least one of claims 1 to 17, characterized in that during method step d) instead of vacuum drag gas to remove the moisture can be used. Method according to at least one of claims 1 to 18, characterized in that the method exclusively in one and the same reactor, preferably in a vacuum mixing dryer carried out becomes. Method according to at least one of claims 1 to 19, characterized in that the method steps a) and / or b) be carried out in mixing reactors and / or kneaders. Method according to at least one of claims 1 to 20, characterized in that method step c) in a drying apparatus carried out which allows fast drying. Method according to at least one of claims 1 to 21, characterized in that method step c) in a spray dryer, Belt dryer or fluidized bed dryer is performed. Method according to at least one of claims 1 to 22, characterized in that method step d) in a drying apparatus carried out in which above 80 ° C can be dried. Method according to at least one of claims 1 to 23, characterized in that method step d) in a drying oven or rotary kiln performed becomes. Amorphous CsAlF complex, available after at least one the claims 1 to 24. CsAlF complex according to claim 25, characterized in that that the onset of fusion of the complex below 440 ° C, preferred below 430 ° C, more preferably below 420 ° C. CsAlF complex according to claim 25 or 26, characterized characterized in that the width of the melting region of the complex at least 30 ° C, preferred at least 50 ° C, more preferably at least 60 ° C is. CsAlF complex according to at least one of claims 25 to 27, characterized in that the width of the melting region of the complex 30 to 90 ° C, preferably from 30 to 80 ° C, more preferably 30 to 70 ° C is. CsAlF complex according to at least one of claims 25 to 28, characterized in that the melting range of the complex between 400 and 500 ° C, preferably from 410 to 490 ° C, more preferably between 415 and 480 ° C. CsAlF complex according to at least one of claims 25 to 29, characterized in that it is 45 to 65 wt .-%, preferably 50 to 60 wt .-%, particularly preferably 55 to 60 wt .-% cesium, 5 to 15 wt .-%, preferably 7 to 13 wt .-%, particularly preferably 8 to 12 wt .-% aluminum and 20 to 40 wt .-%, preferably 25 to 35 Wt .-%, particularly preferably 27 to 33 wt .-% fluorine. CsAlF complex according to at least one of claims 25 to 30, characterized in that the acidity or basicity of the complex by Ad can be adjusted. Use of a CsAlF complex at least one the claims 25 to 31 or available according to a method according to at least one of claims 1 to 24 as a flux, preferably for soldering aluminum.