Hoechst Aktiengesellschaft

Cassella Aktiengesellschaft

Werner Lotz

Hermann Becker

Karlfried Keller

Ulrich Riegel

Fritz Engelhardt

Rolf Kleber

Walter Herwig

Siegfried Noetzel

Karl Hintermeier

Frank Wehowsky

Rudolf Kern

Kuno Reh

Manfred Muller

Heinrich Bathelt

Winfried Ehrl

Karlheinz Fuchs

Jan-Hilbert Mast

Hubert Herdt

Siegmund Haller

Lothar Jackel

Wolfgang Glenz

Helmut Croon

Frank Forster

Hides, skins and pelts are tanned by use of a tanning agent which comprises the reaction product of acetaldehyde, formaldehyde and a formylamino compound.

Tanning agent and a process for its preparation

An improved process for tanning leather by treating animal skins with a water-soluble melamine-formaldehyde resin in the presence of an acid catalyst towards the end is improved by using a melamine-formaldehyde resin which is at least partially etherified with a glycol ether, alkyl glycol ether, or both.

Processing for tanning leather

Use of a resin mixture of, or of a mixed resin from, a melamine-formaldehyde resin and an anionically modified melamine-formaldehyde resin for tanning leather. The anionic modification of the melamine-formaldehyde resin is obtained by preparing the resin in the presence of alkali metal sulfite, alkali metal hydrogensulfite or alkali metal sulfamate. By partial modification it is possible to obtain a mixed resin, while mixing a modified with an unmodified resin gives a resin mixture.

Process for tanning leather

Economy chrome tanning process wherein the pelts are pretreated before the tanning with 0.1 to 2% of an aldehyde- or keto-acid, preferably with glyoxylic acid or pyruvic acid, and are then tanned by customary methods. In this pretreatment, which is preferably carried out in the pickle, the tanning requires a chromium supply of only 1.25 to 1.5% of Cr.sub.2 O.sub.3 on weight of pelt. Despite this reduced amount of chrome tannin the results obtained are boil-resistant leathers with uniform chromium distribution, excellent color levelness and very good physical properties.

Economy chrome tanning process with aldehyde-acids and keto-acids

The novel urethanes correspond to the formula I below ##STR1## in which a denotes a number from 5 to 17 and b denotes a number from 1 to 7. These urethanes are prepared by reacting the corresponding perfluoroalkylethanol/epichlorohydrin adducts with toluelene diisocyanates. The novel aqueous dispersions are essentially composed of the novel urethanes, cationic or betaine emulsifiers and non-ionic emulsifiers, water-insoluble carboxylic and/or dicarboxylic acid esters and alkanediols or polyalkanediols which can be etherified on one or both sides, in water. The novel urethanes and the novel aqueous dispersions are used to impart an oleophobic and hydrophobic finish to textiles, leather and furs. They are also suitable for the treatment of unpainted timber, for example unpainted furniture.

Urethanes containing perfluoroalkyl and epichlorohydrin groups

The specification discloses flame retarding plastic materials which contain, as the flame retarding agent, a phosphinic, diphosphinic or tri-phosphinic acid derived from 2-alkyl-2,5-dioxo-1,2-oxaphospholane and an organic monoamine or diamine or triamine, respectively.

Flame retarding plastic materials

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Niedernhausen, Germany

Werner Lotz