| 摘要 |
The present invention consists of a process for the preparation of lactam by vapour-phase reaction of an aliphatic aminonitrile with water, in the presence of a solid catalyst, characterised in that the catalyst is a metal phosphate of general formula (II): (PO4)nHhM(Imp)p (II> in which: - M represents a divalent, trivalent, tetravalent or pentavalent element chosen from groups IIa, IIIb, IVb, Vb, VIb, VIIb, VIII, IIb, IIIa, IVa and Va of the periodic classification of the elements or a mixture of a number of these elements, or M=O, - Imp represents a basic impregnation compound consisting of an alkali metal or alkaline-earth metal, or of mixtures of a number of these metals, in combination with a counteranion to provide for electrical neutrality, - n represents 1, 2 or 3, - h represents 0, 1 or 2, - p represents a number between 0 and 1/3 and corresponds to a molar ratio of the impregnant (impregnating agent) Imp to the impregnated (PO4)nHhM. The aliphatic lactams, such as epsilon-caprolactam in particular, are base compounds in the preparation of polyamides (polyamide 6 from caprolactam). |
