Basf Aktiengesellschaft

Basf Se Corporation

Manfred Heckmann

Christoph Plachetta

Thomas Heitz

Jan-Martin Löning

Hans-Harald Hünger

Karl Hölemann

Robert Weiβ

Process for purifying and cooling a gas stream comprising a dialkyl ester A) of an aromatic dicarboxylic acid, which comprises treating the gas stream with an aliphatic dihydroxy compound B) at a temperature less than/equal to the melting point of the dialkyl ester A) in a 1st stage and treating the gas stream with an aliphatic dihydroxy compound B) at above the melting point of the dihydroxy compound B) in at least one 2nd stage.

Cooling and purification of gas streams

Disclosed is a method for producing a polyamide containing titanium dioxide pigments. Said method is characterized by the fact that titanium dioxide pigments are dispersed in an initial mixture containing water and caprolactam by means of a device comprising a dispersion chamber, a disk-shaped rotor that is disposed inside said dispersion chamber, a stator that is provided with radial openings, is arranged within the dispersion zone of the dispersion chamber, and is connected to the rotor, a substance inlet located on each side of the rotor, preferably with a respective axial duct section such that the two flows of substance are combined in the peripheral edge area of the rotor disk, and a product outlet which is placed on the outer edge of the dispersion zone of the dispersion chamber, by feeding the titanium dioxide pigments to the dispersion chamber through one of said substance inlets while feeding the initial mixture containing water and caprolactam to the dispersion chamber through the other of said substance inlets, whereby a product mixture containing water, caprolactam, and the used titanium dioxide pigment is obtained via the product outlet, and the product mixture is polymerized so as to obtain a polyamide containing titanium dioxide pigments. Also disclosed are polyamides obtained according to the inventive method and the use of such polyamides as a masterbatch.

Production of a titania-pigmented polyamide

Growing community of inventors

Kuantan, Malaysia

Manfred Heckmann