Basf Aktiengesellschaft

Ehrenfried Baumgartner

Rainer Moors

Rudolf H Jung

Hansjoerg Schaech

Juergen Hofmann

Graham E McKee

Rainer Bueschl

Hermann Gausepohl

Klaus Bronstert

Erhard Seiler

Adolf Echte

Klaus Muehlbach

Klaus Boehlke

Karl Ruppmich

Rainer Neumann

Bertram Ostermayer

Klaus Benker

Hermann Brandt

Juergen Mertes

Baerbel Arnold-Mauer

Juergen Hormann

Rubber-modified, impact-resistant molding materials contain, based on the sum of A, B1 and B2,

ABS molding materials having a bimodal rubber particle size distribution

A process for the continuous preparation of high-impact polystyrene-acrylonitrile (ABS) by free radical-initiated polymerization of a mixture of from 60 to 90% by weight of at least one vinylaromatic monomer and from 10 to 40% by weight of least one further ethylenically unsaturated monomer, in the presence of from 5 to 30% by weight, based on the sum of the monomers, of polybutadiene having a solution viscosity (5% strength by weight in styrene at 25.degree. C.) from 25 to 95 mPa.s and in the presence or absence of a solvent, in at least three consecutive reactors operated essentially without back-mixing, at from 50.degree. to 170.degree. C., phase inversion taking place in one of the reactors, involves carrying out the polymerization as far as phase inversion at 90.degree. C. or below and initiating the polymerization by free radicals from the decomposition of tert-butyl peresters whose half life period at 90.degree. C. is not more than 20 minutes, the polybutadiene content, based on the total reaction mixture, being at least 10% by weight and at most 25% of the total amount of chain-transfer agent (regulator) required being added up to the time of phase inversion and the remainder being added thereafter.

Preparation of ABS molding materials

A process for the continuous preparation of ABS polymers by free-radical-initiated polymerization of, in particular, styrene and acrylonitrile in the presence of polybutadiene, in the presence or absence of a solvent, in a reactor cascade comprising at least 3 stirred reactors operating essentially without back-mixing, at least some of which contain internal cooling tubes for dissipating the heat of polymerization, at from 50 to 180.degree. C., phase inversion taking place in one of the reactors which contains means for generating a high shear force, and an apparatus for carrying out the process comprising an essentially cylindrical/tubular vessel jacket and a cylindrical internal element connected to a stirrer shaft by rotational force and having an external diameter which is slightly less than the internal diameter of the vessel jacket.

Impact-resistant polystyrene acrylonitrile (ABS) is prepared by free radical polymernation of monomeric styrene and acrylonitrile or equivalents thereof in the presence of preformed, dissolved polbutadiene as a grafting base, the solvents used being in particular ethylbenzene and, at least from time to time, the monomers, and phase inversion taking place when the process has progressed to a certain point, in two or more reaction zones, by a continuous process in which the first reaction zone is present at least in duplicate and is in the form of a stirred kettle in each case, so that one stirred kettle is operated batchwise and alternately with the other in such a way that the reaction mixture is polymerized until phase inversion is complete or the initiator has been consumed, and the particular kettle content is then fed continuously to a second reaction zone in the form of a tube reactor.

A rubber-modified, impactresistant acrylonitrile-butadiene-styrene (ABS) molding material, as obtained by polymerizing styrene and acrylonitrile in the presence of a preformed rubber, dissolved in monomeric styrene and acrylonitrile and, if necessary, a solvent, wherein the rubber is a styrene-butadiene block copolymer and at least one further polymer which is compatible with the styrene-butadiene block rubber or its polystyrene component and is incompatible with polystyrene-acrylonitrile.

ABS molding materials

Thermoplastic molding materials based on polyesters and polyphenylene

Thermoplastic molding materials having good low-temperature impact

Thermoplastic molding materials which are free of cyanuric acid or cyanuric acid derivatives contain as essential components,

Thermoplastic molding materials based on toughened polyamide and

A molding material is described which contains, in each based on the sum of A, B and C,

Heat distortion resistant, thermoplastic molding material containing a

Reinforced thermoplastic molding materials containing, as essential components,

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Roedersheim-Gronau, Germany

Ehrenfried Baumgartner