AT332879B - METHOD OF MANUFACTURING MELON - Google Patents

METHOD OF MANUFACTURING MELON

Info

Publication number
AT332879B
AT332879B AT518475A AT518475A AT332879B AT 332879 B AT332879 B AT 332879B AT 518475 A AT518475 A AT 518475A AT 518475 A AT518475 A AT 518475A AT 332879 B AT332879 B AT 332879B
Authority
AT
Austria
Prior art keywords
melon
melamine
heated
dicyandiamide
suspended
Prior art date
Application number
AT518475A
Other languages
German (de)
Other versions
ATA518475A (en
Original Assignee
Chemie Linz Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AT646974A external-priority patent/AT333772B/en
Application filed by Chemie Linz Ag filed Critical Chemie Linz Ag
Priority to AT518475A priority Critical patent/AT332879B/en
Publication of ATA518475A publication Critical patent/ATA518475A/en
Application granted granted Critical
Publication of AT332879B publication Critical patent/AT332879B/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D487/00—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00
    • C07D487/12—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00 in which the condensed system contains three hetero rings
    • C07D487/16—Peri-condensed systems

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Description

  

   <Desc/Clms Page number 1> 
 



   Erhitzt man kleine Mengen von Dicyandiamid oder Melamin in pulverisierter Form bis zum Aufhören der   NHg-Entwicklung   auf 500 bis 600 C, so erhält man in mässiger Ausbeute Melon, eine Verbindung der nachstehenden Formel 
 EMI1.1 
 die in zunehmendem Ausmass an Stelle der giftigen Cyanide in Härtebädern verwendet wird. 



   Die Darstellung dieser Verbindung in technischem Massstab hat sich bisher jedoch als undurchführbar erwiesen, nicht nur, weil beim Schmelzen der pulverisierten Ausgangsprodukte in entsprechenden Apparaten grosse Mengen schwer entfernbarer Krusten aus den verschiedensten Pyrolyseprodukten entstehen, sondern auch, weil ein Teil der genannten Ausgangsprodukte ohne zu reagieren sublimiert. Ausserdem entstehen wäh-   rend des Erhitzens unregelmässig geformte, durch das Entweichen von NHg mehr oder weniger poröse Klumpen    verschiedener Grösse, in denen eine weitere Umsetzung zu Melon wegen der schlechten Wärmeleitung innerhalb tragbarer Reaktionszeiten gar nicht mehr stattfinden kann. 



   Überraschenderweise wurde nun gefunden, dass sich Melon in technischem Massstab und in sehr guter Ausbeute herstellen lässt, wenn man pulverisiertes Melamin und/oder Dicyandiamid in konzentrierten wässerigen   Harnstofflösungen   suspendiert, nach dem Abdampfen des Wassers die Ausgangsprodukte in üblicher Weise zu Granalien verformt und diese erhitzt. 



   Gegenstand der Erfindung ist somit ein Verfahren zur Herstellung von Melon, welches dadurch gekennzeichnet ist, dass man pulverisiertes Melamin und/oder Dicyandiamid in wässerigen Harnstofflösungen mit einem Harnstoffgehalt von 20 bis 80, vorzugsweise von 50 bis 70   Gew.-%   suspendiert, die Mischung nach dem Verdampfen des Wassers auf übliche Weise granuliert und anschliessend auf Temperaturen zwischen 450 bis   600OC,   vorzugsweise 500 bis 5700C erhitzt. 
 EMI1.2 
 : 500kg Melamin1 h erhitzt. Die Melonausbeute bezogen auf das eingesetzte Melamin betrug 78%. 



   Bei einem Harnstoffgehalt von 17% und einstündigem Erhitzen auf 5600C betrug die Melonausbeute bei guter Reinheit 84% bezogen auf das eingesetzte Melamin. Zur Granulierung können alle üblichen Apparaturen, wie Granulierteller oder-trommeln verwendet werden. Für die Umsetzung selbst sind gleichfalls die verschiedensten Öfen brauchbar wie z. B. Muffelöfen, Etagenöfen, Drehrohröfen, Tunnelöfen u. dgl. 

**WARNUNG** Ende DESC Feld kannt Anfang CLMS uberlappen**.



   <Desc / Clms Page number 1>
 



   If small amounts of dicyandiamide or melamine in powdered form are heated to 500 to 600 ° C. until the evolution of NHg has ceased, melon, a compound of the formula below, is obtained in moderate yield
 EMI1.1
 which is increasingly being used in place of the poisonous cyanides in hardening baths.



   The representation of this connection on an industrial scale has so far proven to be impracticable, not only because large quantities of hard-to-remove crusts from various pyrolysis products arise when the powdered starting products are melted in appropriate apparatus, but also because some of the starting products mentioned do not react sublimated. In addition, irregularly shaped lumps of various sizes, more or less porous due to the escape of NHg, arise during heating, in which further conversion to melon can no longer take place within acceptable reaction times due to poor heat conduction.



   Surprisingly, it has now been found that melon can be produced on an industrial scale and in very good yield if pulverized melamine and / or dicyandiamide is suspended in concentrated aqueous urea solutions, after the water has evaporated, the starting products are shaped into granules in the usual way and these are heated.



   The invention thus provides a process for the production of melon, which is characterized in that pulverized melamine and / or dicyandiamide is suspended in aqueous urea solutions with a urea content of 20 to 80, preferably 50 to 70% by weight, the mixture after the evaporation of the water is granulated in the usual way and then heated to temperatures between 450 to 600 ° C, preferably 500 to 5700C.
 EMI1.2
 : 500kg melamine heated for 1 h. The melon yield based on the melamine used was 78%.



   With a urea content of 17% and heating at 5600 ° C. for one hour, the melon yield with good purity was 84% based on the melamine used. All customary apparatus, such as granulating plates or drums, can be used for granulation. A wide variety of ovens can also be used for the implementation itself. B. muffle furnaces, deck furnaces, rotary kilns, tunnel ovens and. like

** WARNING ** End of DESC field may overlap beginning of CLMS **.

Claims (1)

PATENTANSPRUCH : Verfahren zur Herstellung von Melon, dadurch gekennzeichnet, dass man pulverisiertes Melamin und/oder Dicyandiamid in wässerigen Harnstofflösungen mit einem Harnstoffgehalt von 20 bis 80, vorzugsweise von 50 bis 70 Gew.-% suspendiert, die Mischung nach dem Verdampfen des Wassers auf übliche Weise granuliert und anschliessend auf Temperaturen zwischen 450 bis 600 C, vorzugsweise 500 bis 570 C erhitzt. **WARNUNG** Ende CLMS Feld Kannt Anfang DESC uberlappen**. PATENT CLAIM: Process for the production of melon, characterized in that pulverized melamine and / or dicyandiamide is suspended in aqueous urea solutions with a urea content of 20 to 80, preferably 50 to 70% by weight, and the mixture is granulated in the usual way after the water has evaporated and then heated to temperatures between 450 to 600 C, preferably 500 to 570 C. ** WARNING ** End of CLMS field may overlap beginning of DESC **.
AT518475A 1974-08-07 1975-07-04 METHOD OF MANUFACTURING MELON AT332879B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT518475A AT332879B (en) 1974-08-07 1975-07-04 METHOD OF MANUFACTURING MELON

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT646974A AT333772B (en) 1974-08-07 1974-08-07 METHOD OF MANUFACTURING MELON
AT518475A AT332879B (en) 1974-08-07 1975-07-04 METHOD OF MANUFACTURING MELON

Publications (2)

Publication Number Publication Date
ATA518475A ATA518475A (en) 1976-02-15
AT332879B true AT332879B (en) 1976-10-25

Family

ID=25601914

Family Applications (1)

Application Number Title Priority Date Filing Date
AT518475A AT332879B (en) 1974-08-07 1975-07-04 METHOD OF MANUFACTURING MELON

Country Status (1)

Country Link
AT (1) AT332879B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4211508A1 (en) * 1992-04-06 1993-10-07 Chemie Linz Deutschland Non-clumping urea granules - coated with a layer of melamine powder to prevent the granules sticking together

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4211508A1 (en) * 1992-04-06 1993-10-07 Chemie Linz Deutschland Non-clumping urea granules - coated with a layer of melamine powder to prevent the granules sticking together

Also Published As

Publication number Publication date
ATA518475A (en) 1976-02-15

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Legal Events

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