Abstract: An extruder system for degassing a mixture, comprising a first extruder, a second extruder arranged downstream of the first extruder and a transfer zone formed between these extruders, characterized by a pressure regulating device which can regulate the pressure at the outlet of the first extruder.

Abstract: The invention relates to an efficient process for the preparation of isoolefin polymers such as polyisobutene or butyl rubber by polymerization of a liquid medium comprising the monomer(s) and ethane or carbon dioxide that is substantially dissolved therein.

Abstract: The invention relates to an extruder system for degassing a mixture (5), comprising a first extruder (1), a second extruder (2) arranged downstream of the first extruder (1) and a transfer zone (6) formed between these extruders, characterized by a pressure regulating device which can regulate the pressure at the outlet of the first extruder (1).

Abstract: The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Abstract: The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Abstract: The invention relates to a method for degassing elastomer-containing media, such as elastomer solutions and dispersions in particular, and degassing devices (1) for carrying out said method.

Abstract: A stuffing screw (2) for use in an extruder system comprises a housing (7) and at least one conveying screw (5), which is mounted in a rotatable manner within the housing (7), wherein a conveying space is formed between an inner side of the housing (7) and the conveying screw (5). The stuffing screw (2) is characterized in that at least one portion of the inner side of the housing (7) is provided with one or more depressions, in particular in the form of a groove (13).

Abstract: The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Abstract: The present invention relates to a process for devolatilising polymer-containing media such as, in particular, polymer melts, polymer solutions and dispersions and also devolatilisation apparatuses for carrying out the abovementioned process.

Abstract: The present invention relates to a process for devolatilising polymer-containing media such as, in particular, polymer melts, polymer solutions and dispersions and also devolatilisation apparatuses for carrying out the abovementioned process.

Abstract: The present invention relates to water and solvent-free polymers, in particular water and solvent-free synthetic rubber products like non-halogenated and halogenated butyl rubber products as well as a process for the production thereof. The invention further relates to a device suitable to accomplish said process.

Abstract: The invention relates to an energy efficient, environmentally favourable process for preparing water and solvent-free rubber ionomers and/or polymer nanocomposites comprising said rubber ionomers.

Abstract: The present invention relates to a process for devolatilizing polymer-containing media such as, in particular, polymer melts, polymer solutions and dispersions and also devolatilisation apparatuses for carrying out the abovementioned process.

Abstract: The present invention relates to specific water and solvent-free nitrile rubbers having specific functional groups and/or end groups, a process for the production thereof and the use thereof. This process involves removing volatile compounds from a fluid (F) containing (1) at least one nitrile rubber and (2) at least one volatile compound, wherein the process comprises at least the steps of a.) treating the fluid (F) in at least one conversation unit, b.) retreating the concentrated fluid from step a.) in at least one retreating unit and c.) feeding the retreated concentrated fluid from step b.) into at least one retreating unit.

Abstract: The invention relates to a device for dispersing gas into a liquid. The devise has a number n of successive zones Z1, Z2, . . . , Zn having static mixing elements, wherein each zone Zi has a length Li and an effective diameter Di. The mechanical energy input Et, which is standardized to the particular ratio Li/Di and acts on the gas/liquid mixture, increases from zone to zone in the flow direction. In this connection n is a whole number greater than or equal to 3 and i is an index which runs through the whole numbers from 1 to the number n of zones. The invention further relates to a method for dispersing gas into a liquid using the device according to the invention.

Abstract: An integrated process for the solution polymerization and subsequent halogenation of butyl rubber in a common medium is disclosed. The process comprises providing a solution polymerization reactor containing a C6 medium mixed with a monomer mixture comprising at least an isoolefin monomer and a multiolefin monomer in a mass ratio of monomer mixture to medium of from 61:39 to 80:20. Once polymerized, residual unreacted monomer mixture is separated from the rubber solution using a distillation process. The residual monomers may then be purified and recycled back into the reactor. The separated rubber solution is then halogenated. The process obviates the need for separating the rubber from the medium following polymerization, then re-dissolving it in another solvent for halogenation, thereby saving energy cost. The process optionally employs heat exchangers for the reactor feed streams to further reduce energy consumption.

Abstract: The invention relates to a method for degassing elastomer-containing media, such as elastomer solutions and dispersions in particular, and degassing devices (1) for carrying out said method.

Abstract: The present invention relates to a process for devolatilising polymer-containing media such as, in particular, polymer melts, polymer solutions and dispersions and also devolatilisation apparatuses for carrying out the abovementioned process.

Abstract: The present invention relates to a reactor (10) and a process for continuous polymerization, where the reactor (10) has an essentially tubular reactor housing (16). The reactor housing (16) has a drive (38) which runs along the geometric central axis (12) in the flow direction (22) and is configured as a central shaft. A rotatably arranged scraper or wiper (36) is provided within the reactor housing (16); the scraper or wiper (36) has at least one scraper or wiper blade (42) to run along an interior side (44) of the reactor housing (16). The rotational movement of the scraper or wiper (36) results in radial mixing of a stream within the reactor housing (16) which dominates gravity effects and, by virtue of shaping of the scrapers or wipers, optionally makes plug flow or a loop flow or backflow within the reactor (10) or else via an additional external pumped circulation system (23) possible.

Abstract: The invention is directed to an extruder (10), particularly for extruding a synthetic rubber product, which comprises a barrel (24), one or several extruder elements (12, 14), particularly one or several extruder screws and/or a kneader elements (14), arranged inside the barrel (24) for conveying the product, optionally an inlet port for feeding a stripping agent into the barrel (24) and an outlet port for removing volatile compounds from the product and, where applicable, the stripping agent. According to the invention a perforated die plate (26) is fixed to the barrel (24) in flow direction before the outlet port. Since the die plate (26) is not fixed to the extruder elements (12, 14) but to the barrel (24) a circumferential clearance between the die plate (26) and the barrel (24) is prevented so that no extruded material is passing the die plate (26) radially outside.