Dsm N.v.

E.i. Dupont De Nemours and Company

Other

Dsm IP Assets B.v.

E. I. Du Pont Nemours and Co.

Wim Buijs

Samuel L Lane

Henricus F Wolters

Frank Edward Herkes

Nicolaas F Haasen

Rudolf P M Guit

Rudolf Pm Guit

Frank P W Agterberg

Leon H Frijns

Johannes A Kroon

Henricus F W Wolters

Henricus Franciscus Wilhelmus Wolters

Matthias R Offermanns

Ronald J H Hoenen

A process for the simultaneous preparation of polyamide-6 with at least two different viscosities comprising prepolymerisation of &#x3b5;-caprolactam and/or other polyamide-6 precursors in the presence of water, wherein at least part of the necessary water is supplied to the prepolymerisation via the gas phase and the obtained prepolymer is progressively moved and treated with an inert gas in at least two condensation reaction zones or reactors, placed in series, and the prepolymerisation and condensation are carried out in reactor(s) or reaction zones having a self-renewing interface between molten phase and gas phase with a large surface/volume ratio of the molten phase and the molten phase is relatively strong mixed.

Process for the simultaneous preparation of polyamides with at least two different viscosities

The invention relates to a process for the preparation &#x3b5;-caprolactam starting from 6-aminocapronitrile by hydrolysis/oligomerisation followed by de-oligomerisation/cyclisation using superheated steam characterized in that the hydrolysis/oligomerisation is performed with superheated steam converting 6-aminocapronitrile into a molten phase and a gas phase comprising ammonia, ammonia is continuously separated off and the de-oligomerisation/cyclisation is performed by treating the molten phase further with superheated steam. The invention also relates to a process for the preparation of &#x3b5;-caprolactam starting from 6-aminocapronitrile by hydrolysis/oligomerisation followed by de-oligomerisation/cyclisation characterized in that the preparation is performed in a horizontal scraped-surface reactor, the hydrolysis/oligomerisation is performed with superheated steam converting 6-aminocapronitrile into a molten phase and a gas phase comprising ammonia, ammonia is continuously separated off and the de-oligomerisation/cyclisation is performed by treating the molten phase further with superheated steam.

Process for the preparation of &#x3b5;-caprolactam

The invention relates to a method for the hydrolytic polymerisation of &egr;-caprolactam to polyamide-6, comprising a step (a) in which ring opening of part of the &egr;-caprolactam to the corresponding amino caproic acid is effected in the presence of water and a step (b) in which polyaddition and polycondensation are effected under preferably anhydrous reaction conditions, in which at least one of the steps (a) and (b) is carried out in a reactor in which a self-renewing interface between the molten phase and the gas phase with a large surface/volume ratio of the molten phase is effected. The method is preferably effected in an horizontal scraped-surface reactor, since relatively strong mixing of the molten phase can be achieved in these and the molten phase is present in a thin layer, a large gas volume is present having a relatively high partial pressure of the water vapour and the thin layer is constantly renewed by shear forces. The method can be carried out in one reactor, preferably with several reaction zones, or with several reactors in series.

Method for polymerising epsilon-caprolactam to polyamide-6

Process for the preparation of &egr;-caprolactam

Process to prepare &egr;-caprolactam by treating 6-aminocaproic acid, 6-aminocaproate ester or 6-aminocaproamide or mixtures comprising at least two of these compounds in the presence of superheated steam in which a gaseous mixture comprising &egr;-caprolactam and steam is obtained, wherein the process is carried out in the absence of a catalyst at a temperature between 250 and 400&deg; C. and at a pressure of between 0.5 and 2 MPa. The invention also encompasses a process to prepare &egr;-caprolactam starting from 6-aminocapronitrile by performing a hydrolysis and a subsequent step as described above.

Process to prepare &egr;-caprolactam

Process for the preparation of a mixture of .epsilon.-caprolactam, 6-aminocaproic acid and 6-aminocaproic amide by heating an aqueous mixture containing ammonia and oligomers of 6-aminocaproic acid and/or of 6-aminocaproic amide, the aqueous mixture containing 0.5-7 wt. % of equivalent ammonia (calculated as NH.sub.3) and the temperature lying between 280.degree. C. and 330.degree. C., in which by 'equivalent ammonia' is meant free ammonia and ammonia present in the form of a terminal amide group of one of the compounds present in the aqueous mixture.

Process for the preparation of a mixture of .epsilon.-caprolactam,

Process to prepare .epsilon.-caprolactam starting from a liquid aqueous mixture containing an alcohol and 6-aminocaproic acid by cyclization of 6-aminocaproic acid in the aqueous mixture at an elevated temperature. The alcohol is separated from the starting aqueous mixture before performing the cyclization to such extent that the concentration of alcohol in the aqueous mixture during the cyclization is less than 1 wt. %. The advantages include reduced amounts of undesirable by-product.

Process to prepare .epsilon.-caprolactam from 6-aminocaproic acid

Process for the preparation of .epsilon.-caprolactam starting from an aldehyde compound comprising at least one member from among 5-formylvaleric acid, ester or amide in which the aldehyde compound is allowed to react in the presence of ammonia and hydrogen and a subsequent cyclization of the reaction products thus formed (.epsilon.-caprolactam-precursors) to .epsilon.-caprolactam is performed in the presence of water, involved the combination of steps

Process for the preparation of E-caprolactam

A process for the preparation of .epsilon.-caprolactam and .epsilon.-caprolactam precursors, starting from the corresponding 5-formylvalerate ester, ammonia and hydrogen in the presence of a hydrogenation catalyst is disclosed, wherein in a step (a) 5-formylvalerate ester is reacted with ammonia under non-hydrogenating conditions, and in a step (b) the reaction product obtained in step (a) is converted to .epsilon.-caprolactam and the .epsilon.-caprolactam precursor(s) under hydrogenating conditions, in the presence of ammonia.

Process for the preparation of epsilon-caprolactam and

The invention relates to a process for the preparation of a phenol by oxidative decarboxylation of benzoic acid in the presence of a copper-containing catalyst, wherein accumulation of tar components in the reactor is avoided by continuously removing a portion of the reaction mixture from the reactor and subjecting the removed portion to an extraction by contacting the removed portion with water and an auxiliary liquid, which auxiliary liquid is not miscible with water, wherein after extraction an aqueous liquid is obtained with benzoic acid and copper salts and an inorganic solution with tar components, wherein the aqueous solution is recycled to the reactor, the extraction being performed with 0.2 to 14 volume parts of auxiliary liquid per volume part of removed reaction mixture and with 0.5 to 10 volume parts of water per volume part of removed reaction mixture, the quantity of auxiliary liquid being so chosen that the resulting organic solution, containing auxiliary liquid, has a lower density than the aqueous solution, and the temperature during the extraction being higher than 80.degree. C.

Process for removal of tar in a phenol preparation process

The invention relates to a process for the preparation of a phenol by oxidative decarboxylation of a corresponding arylcarboxylic acid in the presence of a Cu-containing catalyst, the phenol being obtained through a hydrolysis step. The characteristic part of the process is oxidation of a Cu(I)-containing catalyst and reduction and hydrolysis in the absence of oxygen. The process can be carried out under liquid phase or gas phase conditions in a one-step or multi-step process and nucleation agents can be added for crystallization during catalyst oxidation. In a preferred embodiment, at least 0.04 wt.% copper remains present as Cu(I) after oxidation.

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Schinnen, Netherlands

Wim Buijs