BE413723A - - Google Patents

Description

       

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  Process for preparing high molecular weight mercaptans.



   It has been found that high molecular weight saturated and unsaturated aliphatic and cycloaliphatic mercaptans are obtained by passing the corresponding high molecular weight alcohols, at elevated temperature and in the presence of hydrogen sulfide, over catalysts and in particular on those. which have a dehydrating action.



   As raw materials for the present process, high molecular weight saturated and unsaturated aliphatic and cycloaliphatic alcohols containing at least 12 carbon atoms or mixtures of such alcohols will be contemplated.



  These alcohols can be prepared, for example, by oxidizing paraffins or by hydrogenating fatty acids obtained from glycerides.

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 natural.



   Depending on the use envisaged for the mixture of mercaptans expected, it is also possible to start from mixtures of higher alcohols and lower alcohols. The reaction will advantageously be carried out at temperatures of between 150 and 450 ° C. and optionally under high or reduced pressure. Apart from raw materials, inert gases or vapors such as nitrogen, carbon dioxide or water vapor may also be present. Instead of pure hydrogen sulphide, it is also possible to use gases containing high proportions. A large number of substances will be considered as catalysts.

   Substances which act in a particularly favorable manner are known dehydrating agents such as for example the oxides and salts (phosphates, halides, sulphates or sulphides) of glucinium, magnesium, calcium, strontium, barium, manganese, cadmium, zinc, copper, nickel, iron, titanium, zirconium, cerium, thorium, lead, phosphorus, vanadium, chromium, molybdenum, tungsten and uranium, which use either singly or mixed together, where appropriate on large surface materials or on metals, minerals or pottery debris. These materials will be used as supplements in either ground or finely divided form in other ways or as carriers in the form of grains or fragments.

   In this order of ideas, we can cite, for example, alkaline, neutral and acid bleaching earths, permutites, zeolites and other silicates, pumice stone, bauxites, terracotta debris, magnesia, glass, wires metal, metal shot, slag and slag, coke, graphite,

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 active gels and activated carbons.



   The mercaptans obtainable by the present process are suitable above all for the preparation of auxiliary substances for dyeing and for coloring.



   EXAMPLE 1
Pass a mixture of 1 part by volume of octodecyl alcohol vapor and 20 to 30 parts by volume of hydrogen sulphide over granular zirconium dioxide at a temperature of about 320 ° C.. The liquid thus obtained, which gradually solidifies in the container, contains 90% of octodecyl-mercaptan in addition to. small amounts of octodecylene and dioctodecyl sulfide. This octodecyl-mercaptan boils at a temperature of 170 to 171 ° C. under a pressure of 1.5 mm. Of mercury; it melts at a temperature of 34-35 C.



   Instead of granulated zirconium dioxide, for example, a mixture of zirconium dioxide and powdered pumice stone can also be used. The activity of the catalysts does not weaken, even after several weeks of service.



   EXAMPLE 2
Pass a temperature of 300 ° C. as described in Example 1 with a mixture of octodecyl alcohol vapor and hydrogen sulphide over activated carbon which has been treated with phosphoric acid. To do this, circulate the hydrogen sulphide in a closed cycle. The crude product isolated from the gas carried out in a closed cycle contains approximately 80% octodecyl-mercaptan.



   EXAMPLE 3
Spray alcohol from white oil

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 whalebone (iodine number 68) in a stream of excess hydrogen sulphide and pass the vapors at a temperature of about 300 ° C over an aluminum oxide catalyst. By fractionally distilling the crude product obtained under reduced pressure, a fraction boiling at temperatures between 151 and 165 ° C. under a pressure of 1 mm is obtained. and which contains about 91 to 92% oleyl mercaptan.



   EXAMPLE 4
Spray dodecyl alcohol in a stream of excess hydrogen sulphide and pass these vapors at a temperature of 330 ° C. over a catalyst composed of granulated titanium dioxide. The crude product obtainable in this way consists of 80% dodecylmercaptan, which boils at temperatures between 95 and 100 ° C. under a pressure of 1 mm. of mercury.



   EXAMPLE 5
On a catalyst such as that employed according to Example 1, pass oleyl alcohol prepared by partial hydrogenation of oleyl aldehyde at a temperature of 300 to 340 C., this alcohol being mixed with forty times its volume of. hydrogen sulfide. The crude product obtained consists of 80% oleyl-mercaptan.



     EXAMPLE 6
Pass a mixture of cetyl alcohol in the vapor state and hydrogen sulfide at a temperature of 320 ° C. over granulated zirconium dioxide. Most of it can be collected by distillation under reduced pressure.



   It boils under a pressure of 0.8 mm. of mercury in the temperature zone between 140 and 155 C.



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Claims (1)

ABSTRACT 1) Process for preparing high molecular weight saturated and unsaturated aliphatic and cycloaliphatic mercaptans containing at least 12 carbon atoms, consisting of passing the alcohols over catalysts, at elevated temperature and in the presence of hydrogen sulfide, corresponding ones or their mixtures with each other or with lower molecular weight alcohols. 2) As new industrial products, the high molecular weight saturated and unsaturated aliphatic and cycloaliphatic mercaptans capable of being obtained by the above-defined process.