Snia Viscosa Societa Nazionale Industria Applicazioni Viscosa

Snia Visdosa Societa Nazionale Industria Applicazioni Viscosa S.p.a.

Mario De Gaetano

Pietro P Rossi

Francesco Siclari

Roberto Leoni

Luigi Canavesi

A process for recovering omega-amino-dodecanoic acid by separating the byoducts from the crude acid that comprises, in the sequence indicated (a) treating the crude acid in the presence of water with an acid (A) in such an amount as to obtain an acid (A)/amino acid molar ratio comprised of between 2:1 and 1:1, the amount of water being such as to dissolve at least part of the salt obtained and not to dissolve at least part of the by-products, (b) separating the phases into one containing most of the salt and another containing most of the by-products, (c) decomposing the salt by treatment with an organic or inorganic base (B) and isolating the amino acid in the free state.

Method for recovering omega-amino-dodecanoic acid from crystallization

A process for continuous or batch preparation of an .omega.-amino-acid is scribed, comprising the imination of an unsaturated aldehyde acid, the catalytic reduction in a single hydrogenation step of the imine of the ethylenically unsaturated straight chain .omega.-aldehyde acid in the presence of ammonia and an alkaline metal hydroxide whereby the alkaline salt of the imine is obtained, and the acidification of the alkaline salt of the .omega.-amino acid. The imine of formyl alkenoic acid is prepared at most at room temperature adding the acid to an ammonia solution of above 10%, then adding NaOH solution to the ammonia solution. The reductive imination is effectuated in two steps, first at 100.degree.-150.degree. C. and the second at 150.degree.-180.degree. C. under a 20-70 Ate pressure in the presence of a nickel catalyst. High yield and only few by-products are obtained.

Process for preparing saturated .omega.-amino acids

A method is disclosed for preparing .alpha., .omega.-diamines by reductive mination of corresponding .alpha., .omega.-dialdehydes with ammonia in an aqueous mixture of butyl alcohol.

Method for preparing .alpha., .omega.-diamines

Aliphatic, linear, saturated or unsaturated .alpha.,.omega.-diamines, conning from 8 to 12 carbon atoms, are prepared from the corresponding .alpha.,.omega.-dialdehydes by firstly converting the dialdehyde to di-imine by reaction with ammonia at less than 25.degree. C. and preferably less than 5.degree. C. in a mixture of water and of an organic solvent, and subsequently subjecting the di-imine to reduction with hydrogen in the presence of a catalyst which under the reaction conditions is capable of reducing all the iminic double bonds while leaving any olefinic bonds unchanged. When olefinic bonds are present and it is desired to obtain a saturated diamine, the unsaturated diamine obtained as hereinbefore stated is subjected to hydrogenation in the presence of a catalyst chosen among palladium, platinum, ruthenium and rodium. Preferred catalysts for the reduction of the di-imine are finely subdivided nickel and cobalt.

Process for the preparation of .alpha.,.zeta.diamines and products

There is described the preparation of a flameproofing compound useful in production of cellulosic fibres having a high resistance to combustion, said preparation comprising treating a phosphonitrile halide with a saturated alcohol, treating the halogen containing alkoxy derivative thus obtained with an unsaturated alcohol, and copolymerizing the alkyl substituted alkoxy derivative product thus obtained with an unsaturated acid, forming an alkaline aqueous solution-suspension adapted to be easily and intimately mixed with alkaline aqueous solutions of cellulose xantogenate to obtain a viscous mass of cospinnable components which are co-coagulable in a cellulose xantogenate coagulating bath. Obtaining essentially homogeneous yarns including the flameproofing compound in their cross-sections.

Method for the production of cellulosic fibres having a high resistance

The specification describes a process for preparing saturated omega-aminods from olefinically unsaturated omega-aldehydoacids. According to the invention, the starting aldehydoacid is transformed into the corresponding iminoacid, and this is subjected to the hydrogenation both of the imino function and of the ethylenic double bond or double bonds, in a single stage and in the presence of an hydrogenation catalyst. The catalyst is a transition metal of one of the first two sub-groups of the VIII group of the periodic system, viz. is chosen among Fe, Ru, Os, Co, Rh, and Ir, and is used in the metal state or as a compound.

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Seregno, Italy

Mario De Gaetano