DE2003932C

DE2003932C -

Info

Publication number: DE2003932C
Application number: DE19702003932
Authority: DE
Filing date: 1970-01-29
Publication date: 1973-04-19

Description

Zusatzadditive OhneWithout %% RaumtemperaturRoom temperature Zcrsclzungsgrad des Bcn/ylchUirids
in "Ό beiDegree of decomposition of the bcn / ylchuride
in "Ό at 95 C95 C Pyrrolidon-(2)Pyrrolidone (2) 9696 50 C50 C nicht bestimmtnot determined 1010 nicht bestimmtnot determined 9696 0.10.1 88th 9191 6666 CaprolactamCaprolactam 0,50.5 1010 1515th 1313th 1,01.0 9494 1212th nicht bestimmtnot determined 0,10.1 1313th nicht bestimmtnot determined 8888 CapryllactamCaprylic lactam 0,50.5 1313th 3535 1616 1,01.0 8787 2121 nicht bestimmtnot determined 0.10.1 88th 9595 7575 LaurinlactamLaurolactam 0,50.5 88th 7070 1717th 1,01.0 7272 1414th nicht bestimmtnot determined 0,i0, i 2222nd 9494 nicht bestimmtnot determined 0,50.5 1010 9494 3030th !,0!, 0 1717th

Beim Destillieren von Benzylchlorid aus einem technischen Gemisch von Toluol, Benzylchlorid, Benzalchlorid und Benzotrichlorid tritt in Gegenwart von nur etwa 0,01 bis etwa 0,05 Gewichtsprozent Caprolactam eine nur kaum noch meßbare Zersetzung ein, da das Ausgangsmaleriai nur Spuren zersetzender Metallverbindungen enthält im Unterschied zu den obigen Tests, die mit einem vergleichsweise sehr hohen Eisenchloridgehalt durchgeführt wurden.When distilling benzyl chloride from a technical mixture of toluene, benzyl chloride, benzal chloride and benzotrichloride occurs in the presence of only about 0.01 to about 0.05 weight percent caprolactam a hardly measurable decomposition, since the initial maleria only traces of decomposing metal compounds In contrast to the tests above, it contains those with a comparatively very high ferric chloride content were carried out.

Da die Siedepunkte der Lactame viel höher liegen als die der Toluolchlorierungsprodukte, ist es praktisch ausgeschlossen, daß Lactamanteile mit überdestillieren. Auf diese Weise wird vermieden, daß die gewünschte zersetzungshemmende Wirkung während der Destillation zu einer unerwünschten reaktionshemmenden Wirkung bei der Weiterverwendung des Benzylchlorids wird.Since the boiling points of the lactams are much higher than those of the toluene chlorination products, it is convenient ruled out that lactam fractions also distill over. In this way it is avoided that the desired anti-decomposition effect during the distillation to an undesirable reaction-inhibiting effect when the benzyl chloride is reused.

Claims

Claim:

Process for the distillation of benzyl chloride or mixtures containing it, characterized in that in Presence of a lactam, suitably in an amount between about 0.01 and about 1 percent by weight, distilled.

It is known that benzyl chloride splits hydrogen chloride relatively easily, especially at high temperatures with the formation of worthless, mostly deeply colored condensation products. This decomposition is already caused by traces of metals and their compounds, especially iron oxides and salts, which can never be completely avoided in technology without great effort.

The decomposition of the benzyl chloride takes place on distillation of the same or more containing it Mixtures, e.g. B. Mixtures with benzal chloride and benzotrichloride, as used in industrial production of the benzyl chloride accumulate, particularly unpleasantly noticeable, since the distillation columns clog by the separation of the condensation products in a relatively short time and in the Enrich sump undistillable residues.

The invention is therefore an improved process for the distillation of benzyl chloride or of this containing mixtures, which is characterized in that in the presence of a Lactams, suitably in an amount between about 0.01 and about 1.0 percent by weight, distilled.

The decomposition of the benzyl chloride and the associated disadvantages when distilling are largely avoided by adding a lactam.

Suitable lactams are e.g. B. Pyrroidon- (2), f-caprolactam, capryllactam and «i-laurolactam.

The stabilizing effectiveness of the addition of lactams is shown by the following test:

1 percent by weight of sublimed ferric chloride and 0.1, 0.5 and 1.0 percent by weight were added to pure benzyl chloride various lactams added. Then the degree of decomposition of the benzyl chloride became in percent after 90 minutes, based on the amount of hydrogen chloride split off, at room temperature, determined at 50 and 95 ° C, as can be seen from the following table: