Abstract: A Polymer compositions that features high degree of toughness, very good processability and extremely high gloss is disclosed. The composition contains (I) a graft rubber polymer obtained by emulsion polymerization of styrene and acrylonitrile in the presence of a mixture of (A) a butadiene polymer latex having a mean particle diameter d50?250 nm, a particle size distribution width of 20 to 80 nm and a gel content of 30 to 95 wt. %, (B) a butadiene polymer latex with a mean particle diameter d50>250 to 350 nm, a particle size distribution width of 30 to 100 nm and gel content of 30 to 80 wt. %, and (C) a butadiene polymer latex (C) with a mean particle diameter d50>350 nm, a particle size distribution width of 40 to 150 nm, and a gel content of 50 to 95 wt. %. and (II) a rubber-free copolymer of styrene and acrylonitrile. At least one of (A), (B) and (C) is a product of seed polymerization.

Abstract: A molding composition having good surface gloss, high elongation at break and good thermoplastic processability is disclosed. The composition contains (A) a graft polymer that is obtained by free-radical polymerization of resin-forming vinyl monomers in the presence of rubber in latex form, (B) a copolymer of styrene and acrylonitrile and an optional (C) a resin selected from the group consisting of polycarbonates, polyester-carbonates, polyesters and polyamides. The preparation of the graft polymer is characterized in that (i) before the start of the grafting polymerization reaction the rubber latex is brought to a pH of 9 to 11, (ii) the redox initiator components are employed in amounts of 0.1 to 2.5 wt. % (based on the monomers metered in) and (iii) during the entire grafting polymerization reaction the pH remains constant±0.5 and in the range of 11.0 to 8.8, and (iv) the temperature difference between the start and end of the reaction is at least 10° C.

Abstract: The invention relates to a process for the preparation of graft rubber polymers of the ABS type by emulsion polymerization according to the so-called fed batch process, in which latexes having markedly reduced residual monomer contents are obtained, and to compositions containing the mentioned graft rubber polymers.

Abstract: The invention provides compositions comprising a graft polymer obtainable by free-radical polymerization, a vinyl (co)polymer and optionally resins chosen from the group consisting of polycarbonates, polyester-carbonates, polyesters and polyamides, characterized in that the preparation of the graft polymer A) is carried out by a procedure in which before the start of the grafting polymerization reaction the rubber latex is brought to a pH of 9 to 11, the redox initiator components are employed in amounts of 0.1 to 2.5 wt. % (based on the monomers metered in) and during the entire grafting polymerization reaction the pH should not exceed a value of 11.0 and should not fall below a value of 8.8 and the pH remains constant during the reaction within a range of variation of ±0.5 units, and the temperature difference between the start and end of the reaction is at least 10° C.

Abstract: An elastic-thermoplastic graft polymer prepared by a multi-stage free radical polymerization is described. The elastic-thermoplastic graft polymer is prepared by polymerizing (i) one or more monomers containing vinyl groups, and (ii) at least one molecular weight regulating compound, in the presence of (iii) at least one rubber in latex form. The ratio of monomers (M) to the molecular weight regulating compound (MWR) is altered throughout the various stages of the polymerization method. The M:MWR ratio is: from 50:1 to 400:1 in the first stage; from 100:1 to 800:1 in the second stage; and from 200:1 to 2000:1 in the third stage of the polymerization. In at least one further reaction stage of the polymerization, the monomers, in the absence of the molecular weight regulating compound, are polymerized in the presence of the rubber. This further reaction stage occurs before the first stage and/or after the third stage of the polymerization.

Abstract: The invention relates to ABS moulding compositions, wherein the graft rubber polymers contain 3 butadiene polymer latices of defined particle size, particle size distribution and gel content, and wherein at least one polybutadiene latex has been produced by seed polymerisation.

Abstract: An elastic-thermoplastic graft polymer prepared by a multi-stage free radical polymerization is described. The elastic-thermoplastic graft polymer is prepared by polymerizing (i) one or more monomers containing vinyl groups, and (ii) at least one molecular weight regulating compound, in the presence of (iii) at least one rubber in latex form. The ratio of monomers (M) to the molecular weight regulating compound (MWR) is altered throughout the various stages of the polymerization method. The M:MWR ratio is: from 50:1 to 400:1 in the first stage; from 100:1 to 800:1 in the second stage; and from 200:1 to 2000:1 in the third stage of the polymerization. In at least one further reaction stage of the polymerization, the monomers, in the absence of the molecular weight regulating compound, are polymerized in the presence of the rubber. This further reaction stage occurs before the first stage and/or after the third stage of the polymerization.

Abstract: The invention relates to a process for the preparation of graft rubber polymers of the ABS type by emulsion polymerization according to the so-called fed batch process, in which latexes having markedly reduced residual monomer contents are obtained, and to compositions containing the mentioned graft rubber polymers.

Abstract: Organic carbonates containing at least one aromatic ester group can be obtained in a continuous manner from carbonates containing at least one aliphatic ester group and a phenolic compound in the presence of a transesterification catalyst known per se by carrying out the reaction in at least two stirred containers connected one behind the other in such a way that, in each case, the phenolic compound is metered in liquid form into the first stirred container and the carbonate containing at least one aliphatic ester group is metered in liquid form into one or more of the stirred containers. The carbonate containing at least one aromatic ester group is removed in liquid form from the last stirred container. Volatile reaction products, for example alcohol which has been cleaved out or a dialkyl carbonate are removed in gaseous form from one or more stirred containers.