Basf Aktiengesellschaft

Rudi-Heinz Rotzoll

Paul Matthies

Georg Pilz

Albrecht Eckell

Werner Hoerauf

Guenter Valentin

Paul Duffner

Gerhard Thiel

Ernst Dietl

A process for the continuous preparation of polycaprolactam, which comprises polymerizing .epsilon.-caprolactam in a vertical tubular reactor through which the .epsilon.-caprolactam flows downward, wherein the .epsilon.-caprolactam is partially polymerized, at a nylon-forming temperature, in a mechanically mixed zone, the reaction mixture is circulated through a heat exchange zone in the lower part of the mechanically mixed reaction zone, and is polymerized further, in additional heat exchange zones, until the desired degree of polymerization is reached, and poly-.epsilon.-caprolactam is then discharged as a melt, and an apparatus for carrying out the process.

Continuous preparation of polycaprolactam in vertical tubular reactor

A process for the manufacture of nylons by heating an aqueous solution of a salt of an alkanedicarboxylic acid of 6 to 12 carbon atoms and a diamine of the formula NH.sub.2 RNH.sub.2, where R is alkylene of 6 to 12 carbon atoms or is a radical ##STR1## to a temperature at which a nylon is formed, under superatmospheric pressure and with removal of water. The solution used is an aqueous solution of from 75 to 90 percent strength by weight of a salt of a dicarboxylic acid and a diamine, which solution has been obtained by neutralizing a less concentrated salt solution, which contains an appropriate dissolved excess of the particular dicarboxylic acid, with the corresponding diamine. The nylons obtained are used for the manufacture of moldings.

Manufacture of nylon by adding liquid diamine to aqueous polyamide

A process for the continuous preparation of an aqueous solution of a salt of an alkanedicarboxylic acid of 6 to 12 carbon atoms and an alkanediamine of 6 to 12 carbon atoms by reacting the particular alkanedicarboxylic acid with the particular alkanediamine in an aqueous solution of the salt to be prepared. The aqueous salt solution is recycled from a first mixing zone via a transport zone and a second mixing zone into the first mixing zone, liquid alkanediamine and an aqueous solution of alkanedicarboxylic acid are introduced between the first and second mixing zones. Less than the equivalent amount of alkanediamine is introduced, the remaining amount of liquid alkanediamine is added after the second mixing zone, and aqueous salt solution is taken off the first mixing zone at the rate at which it is formed. The salt prepared is used for the manufacture of a nylon.

Continuous manufacture of an aqueous solution of a salt of an

A process for the manufacture of a highly concentrated aqueous solution of a salt of a dicarboxylic acid and a diamine, as well as of a nylon precondensate, by reacting an alkanedicarboxylic acid of 6 to 12 carbon atoms and a diamine of the formula NH.sub.2 RNH.sub.2, where R is alkylene of 6 to 12 carbon atoms or is ##STR1## An aqueous solution, of lower concentration, of a salt of a dicarboxylic acid and a diamine, containing an appropriate dissolved excess of the particular dicarboxylic acid, is reacted with the particular diamine in the molten state, in an equivalent amount to the dissolved dicarboxylic acid, the reaction being carried out under superatmospheric pressure and the final reaction temperature being kept at from 140.degree. to 210.degree. C. The solution obtained is used for the manufacture of a nylon.

Growing community of inventors

Limburgerhof, Germany

Rudi-Heinz Rotzoll