Bayer Aktiengesellschaft

Martin Ullrich

Heinrich Schuchardt

Ulrich Liesenfelder

Klaus Schebesta

Manfred Hederich

Erhard Tresper

Stephan Kirchmeyer

Frank Wingler

Roland Rupp

Viktor Trescher

Erhard Schellmann

Ernst Bocker

Wolfgang Kracht

Hanns P Muller

Uwe Hucks

Wolfgang Alewelt

Eberhard Zirngiebl

Steffen Kuhling

Gunter Sackmann

Alfred Eitel

Gottfried Zaby

Thomas Fischer

Rolf Bachmann

Karl-Heinrich Meyer

Hanns-Peter M&uuml;ller

Lothar Liebig

Ernst Meisert

Wolfgang M Eisermann

Helmut Brod

Franz Ferdinand Rhiel

Hanno Henkel

Sergej Schapowalow

Siegfried Gruhl

Klaus Holzer

Hans-Hermann Heins

Gerd Wassmuth

Claus Rathjen

Karl-Dieter Lohr

Werner Pusch

Rudolf Erdmenger

Peter Danz

Hans-J&uuml;rgen Thiem

Heinz Gemperlein

Karl-Friedrich Jerchel

The present invention relates to a continuous process for the production of impact resistance-modified thermoplastics. An elastomer, in particular a particulate graft polymer with a water moisture content of 1 to 50%, preferably 10 to 40%, is incorporated into a thermoplastics melt in a large volume kneader reactor. The mixing ratio of elastomer to thermoplastics melt is 4:1 to 1:4. The energy required to melt the elastomer and to evaporate the adhering water is added by heating the walls of the apparatus and via the kneading action of the installed rotating parts.

Process for the production of elastomer-modified thermoplastics

A process for the production of thermoplastic polyurethane elastomer is disclosed. The process entails (a) introducing and homogeneously mixing in a first static mixer (A) an isocyanate and (B) a mixture of compounds having an average of 1.8 to 3.0 Zerewitinoff active hydrogen atoms having a molecular weight of 400 to 10000 with and chain extenders having an average of 1.8 to 3.0 Zerewitinoff active hydrogen atoms and a molecular weight of 62 to 400 and optional auxiliaries to form a substantially unreacted mixture and (b) reacting said substantially unreacted mixture in a second static mixer to form thermoplastic polyurethane elastomer. The elastomer thus produced has improved mechanical properties and is suitable for the production of moldings.

Thermoplastic polyurethane elastomers

The invention relates to a fully self-cleaning reactor/mixer having a large freely usable volume, that cleans itself kinematically, consisting of two or more parallel shafts (2, 2') rotating in opposite directions, on which are located spirally arranged, axially offset paddles (3, 3') with scrapers (4, 4', 5, 5') on the front and rear of the paddles, and a surrounding housing (1). Since all the scrapers (4, 4') on the upstream side of the paddles (3, 3') convey the material concerned outwards and all the scrapers (5, 5') on the downstream side of the paddles convey the material inwards, axial conveyance is obtained.

Self-cleaning reactor/mixer for highly viscous and cohesive mixing

The invention relates to a two-step melt process for the production of thermoplastic, solvent-free, low-branching polycarbonates with low --OH terminal group content using a self-cleaning high-viscosity reactor.

Two-step process for the production of thermoplastic polycarbonate

Thermoplastic polyurethaneurea elastomers prepared from organic polyisocyanates (A) and a mixture (B) containing Zerewitinoff active hydrogen atoms are disclosed. The mixture (B) is prepared from 1) 40 to 85 equivalent-% (relative to isocyanate groups in (A)) of one or more compounds having an average of at least 1.8 Zerewitinoff active hydrogen atoms and a number average molecular weight of 400 to 10,000, 2) 10 to 60 equivalent-% (relative to isocyanate groups in (A)) of water and 3) 0 to 45 equivalent-% (relative to isocyanate groups in (A)) of one or more chain extenders having an average of at least 1.8 Zerewitinoff active hydrogen atoms and a molecular weight of 62 to 400. The preparation process comprise mixing (A) and (B) in a static mixer under conditions in which no reaction occurs between (A) and (B), and reacting the mixture in a second static mixer. The resulting polyurethaneurea elastomer is useful for the production of moldings.

Thermoplastic polyurethaneurea elastomers

A process for the continuous production of superabsorbent polymers, characterised in that aqueous emulsions of uncross-linked and cross-linked polyacrylonitrile homopolymers and/or copolymers, the polyacrylonitrile concentrations in the reaction mixture being from 10 to 45 w.t. %, are hydrolysed with aqueous alkali hydroxide solutions at 50.degree. to 100.degree. C. in a continuously operating reactor suitable for carrying out highly viscous reactions, and that from the highly viscous gels formed the products in the form of superabsorbent powders are continuously precipitated by means of continuous precipitation using low-boiling monoalcohols, and the use thereof in sanitary articles, as water-storing materials in agriculture or for sheathing electrical cables.

Process for the continuous production of superabsorbent polymers from

A multi-axis mixer/reactor with a large available useful capacity, which is kinematically self-cleaning, comprising at least one housing one, two or more parallel, contrarotating shafts 2, 2', on which intermeshing groups of gear wheels 3, 3' are disposed in an axially spaced-apart manner. The gear wheels 3, 3' are connected to one another by kneading bars 5, 5', while further kneading bars 4, 4' which are connected in each case only to one gear wheel are likewise disposed on the end faces of the gear wheels.

Completely self-cleaning mixer/reactor

A self-cleaning reactor/mixer, in particular a disk reactor, with a large available useful capacity, which cleans itself kinematically, comprising at least two or more parallel shafts rotating in the same direction, on which axially offset, not necessarily circular disks with scrapers distributed on their circumference are situated, and a surrounding housing. The reactor/mixer on account of the special geometry of its rotors, which extensively avoids acute product-side angles, is particularly suitable for processing solids-bearing materials to be mixed.

Self-cleaning reactor/mixer for highly viscous and solids-bearing

The invention relates to disc reactors with a large free usable volume which are kinematically self-cleaning, consisting of two or more parallel counterrotating shafts, on which toothed discs with scrapers, which are distributed over their circumference, are disposed, and a surrounding housing. The toothed discs are arranged perpendicularly to the axes of rotation in planes which are echeloned one behind the other such that they mesh with one another.

Fully self-cleaning reactor/mixer with a large usable volume

Disc reactors with large free useful volume which clean themselves kinematically, consisting of two or more parallel shafts, rotating in the same or opposite directions, on which are located axially staggered, circular discs with scrapers distributed over their periphery, and an enclosing casing.

Self-cleaning reactor/mixer with large useful volume

A carbon- and nitrogen-based catalyst consisting essentially of active carbon or active coke and comprising at least 90% by weight of graphite structures containing at least 10% of pores larger than 100 nm in diameter and having incorporated therein an isocyanate which forms C-N-ring structures, the percentage graphite content being at least 90% by weight. The catalayst is especially effective in the low temperature reduction of nitrogen oxides in waste gases.

Catalyst for the reduction of nitrogen oxides from waste gases and a

On a single-screw or multi-screw extruder, the part of the barrel lying between a front plate (1) and end plate (2) bounding the processing unit is subdivided into barrel discs (5) of ceramic materials, which are arranged on at least one guide rail (7). The barrel discs (5) are held together by an anchor (9) fixed on the front plate (1) and end plate (2) and at the same time secured against twisting. In addition, the screw elements (3) within the processing unit between front plate (1) and end plate (2) are also made from the same or from another ceramic material.

Extruder with ceramic processing unit

The isolation of polyarylene sulphides by freeing polyarylene sulphides of the type obtained in customary production processes from adherent water and any other volatile constituents by treating the polyarylene sulphides in screw machines and optionally melting them either simultaneously or subsequently.

Process for the isolation of polyarylene sulphide

The discharge apparatus comprises an at least four-shaft screw pump having engaging shafts (1,2,3,4) which rotate in opposite directions in pairs. The viscous product to be processed is caught up over a large area and removed by the screws. A double shaft screw pump is connected downstream of the actual collection zone as a pressure build-up zone. The two center screws (2, 3) of the collection zone merge equiaxially into the screw shafts (2a, 3a) of the pressure build-up zone. The collection zone and the pressure build-up zone are combined into one constructional unit. At least one screw shaft is driven. The resulting high viscosity product strands (7) are caught up by the screws in the collection zone and are moved on into the pressure build-up zone. The double shaft screw pump is used for the build up of a high operational pressure and thus provides the prerequisite for the subsequent connection of further procedural stages. The universal possibilities of use of this discharge apparatus are to be stressed in particular.

Apparatus for discharging high viscosity media in chemical engineering

Growing community of inventors

Leverkusen, Germany

Martin Ullrich