Basf Aktiengesellschaft

Karl Gerberding

Hermann Gausepohl

Erhard Seiler

Adolf Echte

Gerhard Fahrbach

Klaus Bronstert

Juergen Hambrecht

Dieter Stein

Helmut Jenne

Gerhard Hoffmann

Gerhard Heinz

Walter Heckmann

Franz Brandstetter

Peter Richter

Wolfgang F Mueller

Rudolf H Jung

Burghard Schmitt

Hans Mittnacht

Ingo H Dorn

Jurgen Pohrt

Juergen Pohrt

Paul Witimer

Ruediger Matern

Mixtures which can be crosslinked by photopolymerization and are based on binders, photopolymerizable monomers which are compatible with these, photoinitiators and thermal polymerization inhibitors contain, as the binder, polymers of the formula I ##STR1## where Pol is a radical of a block copolymer prepared by sequential anionic polymerization of conjugated dienes and vinyl aromatics,

Elements having layers containing mixtures which can be crosslinked by

Block polymers of vinylaromatic compounds and conjugated dienes which possess acidic terminal groups, are present in the form of lithium salts and form an aluminum complex. A process for the preparation of such complexes and the use of these block polymer complexes as molding materials and for modifying thermoplastic materials.

Transparent, impact-resistant styrene block polymers and their

A thermoplastic molding material comprises copolymers I and II. Copolymer I is a high-impact (graft) copolymer which is derived from a monovinyl-aromatic monomer and a polymer or copolymer predominantly containing polymerized 1,3-diene units, and is present in a proportion of 0.1-1.0% by weight, based on the molding material. Copolymer II is a block copolymer with star-shaped branching, ie. a radial block copolymer, having an average of more than two branches per molecule. It is substantially derived from 55-80% by weight of a monovinyl-aromatic monomer and 20-45% by weight of a 1,3-diene monomer. The molding material may contain conventional assistants and is used for the production of blown film.

Thermoplastic molding material

A process for the continuous preparation of rubber-modified polymers of vinyl-aromatics, wherein a mixture which contains a monomeric aromatic vinyl compound and from 3 to 30% by weight, based on the monomer, of an elastomeric polymer, with or without a solvent, is polymerized, in the presence of a free radical initiator and in the presence or absence of a mercaptan as chain transfer agent, at from 80.degree. to 180.degree. C., with stirring, in a cascade of two or more isothermally operated reaction zones and of one or more additional reaction zones which can be operated isothermally or with a rising temperature profile in such a way that the residence time of the reactants in the first reaction zone is .ltoreq.35 minutes. The polymer obtained is freed from vinyl-aromatic monomer, and from any solvent, in a devolatilization zone. The product is useful for the production of injection moldings.

Continuous preparation of rubber-modified polymers of vinyl-aromatics

Thermoplastic molding materials based on styrene polymers modified to be impact resistant with EPDM rubbers and polyphenylene ethers wherein the particles of the flexible components of the impact resistant styrene polymer have an average particle diameter range of 0.3 to 0.7 microns.

Thermoplastic molding materials

A process for making ABS polymer particles comprising continuous polymerization of a mixture of at least one of each of (a) an aromatic vinyl monomer, and (b) an ethylenically unsaturated monomer in a weight ratio of (a):(b) of 90:10 to 10:90 in the presence of at least one of each of (c) a rubber-like polymer in an amount of 3 to 35 percent by weight relative to the total weight of the monomers (a) and (b), (d) a solvent, (e) a radical initiator and (f) an optional chain transfer agent. The process is carried out at temperatures between 80.degree. C. to 180.degree. C. in two or more reaction zones while the reaction mixture is stirred and while the monomers and solvents are removed in a degassing zone. The rubber-like polymer (c) has a solution viscosity of less than 80 mPa.s and a ratio of the solution viscosity of (c) to a percent of solvent expressed by 100[(d)/(a+b+c+d)] equal to or less than 2.5 mPa.s/percent of solvent.

Process for the manufacture of ABS polymers and use thereof in

A process for the preparation of branched block copolymers of from 60 to 95% by weight of a monovinyl-aromatic monomer and from 40 to 5% by weight of a conjugated diene by polymerizing the monomers in an inert solvent in the presence of a monolithium-hydrocarbon as the initiator, wherein, in a first process stage (a), from 50 to 80, or where necessary at most 90, % by weight of the total amount of monovinyl-aromatic compound are polymerized to virtually complete conversion in the presence of a relatively small amount of the monolithium-hydrocarbon. This stage is carried out by starting with from 30 to 70% by weight of the vinyl-aromatic monomer and adding from 70 to 30% by weight in the feed, during the polymerization, in such a way that the polymerization temperature, which at the start of the polymerization is from 30.degree. to 40.degree. C., is kept at from 45.degree. to 70.degree. C., with use of reflux cooling. After all the monomer feed has been added, the reaction temperature is lowered to 30.degree.-40.degree. C. by evaporative cooling. In a second process stage (b), an additional amount of initiator is added to the reaction solution, after which from 1 to 30% by weight of the total amount of monovinyl-aromatic monomer can be added, the sum of the amounts of monovinyl-aromatic monomer added in the first and second process stages being at most 90% by weight of the total amount of monovinyl-aromatic monomer. The monovinyl-aromatic monomer added in the second process stage is polymerized to virtually complete conversion, employing the temperature profile described for stage (a). In process stage (c), the remainder of the monovinyl-aromatic monomer and all of the conjugated diene are added, at least predominantly in the form of a mixture, and polymerized so that the reaction temperature does not rise above 90.degree.-110.degree. C. Finally, after virtually complete conversion of the monomers, and preferably without prior cooling, a suitable liquid polyfunctional coupling agent is run in undiluted and the mixture of the linear block copolymers obtained, which still contain active terminal lithium-carbon bonds, is coupled, with stirring, to form branched block copolymers. The products prepared according to the invention are used for injection molding.

Preparation of branched block copolymers

A process for the preparation of a mixture of linear three-block copolymers which contain from 70 to 80% by weight of styrene units and from 20 to 30% by weight of elastomeric polymer segments based on a conjugated diene, in a total of three stages, specific conditions in respect of the initiator and of the monomers to be polymerized being essential in the individual stages in order to ensure the polymodal structure of the three-block copolymers. After complete reaction of the monomers, the mixture of the living polymers is treated with proton-active compounds, and the mixture of the block copolymers is isolated by removing the solvent. The compositions obtained by the novel process are transparent and clear and have good mechanical properties. They are furthermore readily processable by the methods conventionally used for thermoplastics. The compositions are particularly suitable for the production of moldings and of packaging materials.

Preparation of mixtures of linear three-block copolymers, and moldings

Branched block copolymers of from 60 to 95 percent by weight of a monovinyl-aromatic compound and from 40 to 5 percent by weight of a conjugated diene. The branched block copolymers have a structure of the general formula

Branched block copolymers and their manufacture

Branched block copolymers of from 60 to 95 percent by weight of a monovinyl-aromatic compound and from 40 to 5 percent by weight of a conjugated diene. The copolymers have a structure of the general formula

Block or graft copolymers consisting of a substantially linear elastomer block B and one or more copolymer blocks A of alternating structure. The ends of block B are joined to the blocks A by divinyl- or divinylidene-aromatic monomer units. The block or graft copolymers may be used as impact-resistant thermoplastic molding compositions for the manufacture of shaped articles or as emulsifiers in the solution graft polymerization of styrene and acrylonitrile to a rubber.

Growing community of inventors

Wachenheim, Germany

Karl Gerberding