Abstract: A process of producing a graft polymer of the ABS type by the emulsion method is disclosed. In the process wherein 5 to 95% by weight of a monomer mixture that contains A) 50 to 99 parts by weight of at least one vinyl aromatic compound and B) 1 to 50 parts by weight of at least one copolymer is polymerized in the presence of C) 95 to 5% by weight of one or more graft substrates having a glass transition temperature <10° C., the improvement includes monitoring continuously in the course of the reaction the Raman spectra of the reaction mixture, determining deviations from the specified desired course of the reaction and making corresponding adjustments.

Abstract: A thermoplastic molding composition that features a combination of good notched impact strength and thermoplastic processability is disclosed. The composition contains one or more thermoplastic (co)polymers, a graft polymer and a combination of at least 3 components chosen from a compound (I) having at least one structural unit conforming to where M=a metal, and n=the valence of the metal M, and a compound (II) having at least one structural unit conforming to and a compound (III) having at least one structural unit conforming to and a compound (IV) that contains none of the structural units of (I), (II) and (III).

Abstract: A thermoplastic molding composition that features constancy of properties, especially toughness and processability is disclosed. The composition contains a first graft rubber polymer that is a product of emulsion polymerisation of styrene and acrylonitrile in the presence of a butadiene polymer latex (A) with a mean particle diameter d50 of 80 to 220 nm, a second graft rubber polymer obtained by emulsion polymerisation of styrene and acrylonitrile in the presence of a butadiene polymer latex (B) with a mean particle diameter d50 of 340 to 480 nm, and a rubber-free copolymer of styrene and acrylonitrile. Importantly, the butadiene polymer latex (A) is the product of seed polymerization using a seed latex with a mean particle diameter of 10 to 100 nm, and the butadiene polymer latex (B) is the product of seed polymerisation using the butadiene polymer latex (A) as seed latex.

Abstract: A thermoplastic molding composition that contains a plurality of graft rubbers is disclosed. A first graft rubber is a product of emulsion polymerization of a mixture containing styrene and acrylonitrile in the presence of butadiene polymer latex (A) having an average particle diameter (d50) of 80 to 220 nm. An additional graft rubber is a product of emulsion polymerization of a mixture containing styrene and acrylonitrile in the presence of butadiene polymer latex (B) having an average particle diameter (d50) of 350 to 650 nm. The butadiene polymer latex (A) is the product of seed polymerization in which seed is butadiene polymer latex having a median particle diameter of 10 to 100 nm, and the butadiene polymer latex (B) is the product of agglomeration in which butadiene polymer latex (A) is the starting latex.

Abstract: A thermoplastic molding composition of the ABS type is disclosed. The composition that contains an elastic-thermoplastic graft polymer and a copolymer comprising styrene and acrylonitrile, is characterized in that the graft polymer is a product of radical emulsion polymerization process that is initiated by a combination of a persulfate compound and at least one azo compound and in that a first mixture that contains said azo compound and a first amount of monomers is fed in to a rubber in latex form and in a subsequent reaction step a second mixture is introduced that contains the persulfate compound and a second amount of monomers.

Abstract: A thermoplastic molding composition suitable for producing article having improved surface quality is disclosed. The composition includes A) at least one polymeric resin selected from the group consisting of polycarbonate, polyester carbonate, polyamide, polyalkylene terephthalate and polyoxymethylene, and B) a co-precipitated mixture of graft polymer B.1 the preparation of which entailed redox initiation and graft copolymer B.2 the preparation of which entailed persulfate initiation.

Abstract: A thermoplastic, flame-retardant moulding composition having improved mechanical properties is disclosed. The composition contains 40 to 99 parts by weight of a thermoplastic polycarbonate or polyester carbonate, 0.5 to 60 parts by weight of a graft polymer, 0 to 45 parts by weight of a thermoplastic vinyl copolymer, 0.5 to 20 parts by weight of a mixture of at least one mono- and at least one oligo-phosphorus conforming to the general formula and 0.05 to 5 parts by weight of a fluorinated polyolefine.

Abstract: A process for working up polymer components prepared by emulsion polymerization is disclosed. The process is characterized in that coagulation of the aqueous polymer latex present after emulsion polymerization is performed using a combination of A) an aqueous solution of at least one salt selected from the group consisting of sodium chloride, calcium chloride, magnesium chloride, aluminum chloride, sodium sulfate, magnesium sulfate and aluminum sulfate, B) an aqueous solution of at least one salt of an acid selected from the group consisting of hypophosphorous acid (H3PO2), phosphorous acid (H3PO3 or HPO2) and ascorbic acid and optionally C) an aqueous dilute acid selected from the group consisting of sulfuric acid, phosphoric acid and acetic acid.

Abstract: A thermoplastic molding composition having an improved profile of properties is disclosed. The composition contains A) a graft rubber that is a product of free-radical emulsion polymerization of vinyl monomers in the presence of rubber a) that is present in latex form and having a glass transition temperature below 0° C., using at least one peroxydisulfate compound as an initiator, and B) a graft rubber that is a product of free-radical emulsion polymerization of vinyl monomers in the presence of at least one rubber b) that is present in latex form and having a glass transition temperature below 0° C.

Abstract: A molding composition containing a graft polymer is disclosed. The graft is a product of a free-radical emulsion polymerization of resin-forming vinyl monomers in the presence of rubber present in latex form having a glass transition temperature of ≦0° C. using an initiator combination comprising a persulfate compound and a redox initiator system. The process for preparing the graft polymer entails adding the persulfate compound at the beginning of the graft polymerization reaction and a later addition of the redox initiator. The composition that features good gloss and flowability is suitable for the preparation of molded articles.

Abstract: A process for preparing a thermoplastic molding composition of the ABS type is described. The process includes: (A) forming at least one graft rubber A) using a rubber latex having a d50 value of <200 nm; (B) forming at least one graft rubber B) using a rubber latex having a d50 value of ≧200 nm; and forming a rubber-free thermoplastic polymer resin C). The method further includes: (D) forming precipitates of graft rubbers A) and B); (E) de-watering the precipitates to form water moist powders of graft rubbers A) and B); and mixing the water-moist powders of graft rubbers A) and B) with polymer C) in a kneader reactor. Graft rubbers A) and B) may be prepared separately or in a single step. The content in wt. % of rubber originating from graft rubber component A) based on the total amount of rubber in the molding composition is at least 5 wt. % lower than the content of rubber in wt.% originating from graft rubber component B), in each case based on 100 parts by wt. of graft rubber.

Abstract: A thermoplastic molding composition comprising A) a thermopolastic polymer, e.g., a copolymer of styrene and acyrlonitrile, B) a graft copolymer, e.g., a graft copolymer of styrene, acrylonitrile and polybutadiene, and C) an additive mixture is described. The additive mixture C) comprises a combination of at least three components selected from components (I), (II), (III) and (IV). Component (I) contains carboxylic acid metal salt groups, e.g., magnesium stearate. Component (II) contains both carboxylic acid ester linkages and thio linkages, e.g., esters of &bgr;-thiodipropionic acid with monhydric alcohols. Component (III) contains amide linkages, e.g., ethylenediamine bisstearyl amide. Component (IV) is a compound that is different than components (I)-(III), e.g., a low molecular weight styrene/acrylonitrile copolymer. Also described are molded articles prepared from the thermoplastic molding composition of the present invention.

Abstract: Thermoplastic molding compositions containing graft polymers produced with different initiator systems are disclosed. The compositions are distinguished by a combination of good toughness and reduced opacity. As a result, appreciably smaller quantities of pigment are needed to color the molding composition.

Abstract: A thermoplastic molding composition that exhibits antistatic properties and improved color stability is disclosed. The composition contains a major amount of resinous component that contains A) 0 to 100 % by weight of one or more graft polymers B) 100 to 0 % by weight of a thermoplastic vinyl (co)polymer, and a minor amount of a mixture of a) a modified or unmodified polyalkylene ethers and b) a phenolic oxidant wherein the weight ratio (a):(b) is 20:1 to 1:1.

Abstract: An additive mixture containing a dibenzoate and either or both of a compound containing at least one structural unit and a compound containing at least one structural unit is disclosed. The additive combination enhances the processability of a thermoplastic molding composition that contains a (co)polymer of styrene, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic anhydride and N-substituted maleimide and a graft copolymer.

Abstract: A stabilizing composition that contains as an antioxidant a compound having in its molecular structure at least one sterically hindered phenol and a water-soluble inorganic salt of a phosphorus acid is disclosed. The composition is suitable for providing stability to a variety of polymeric resins. Also disclosed is a process for the production of thermally stable graft rubber polymers and molding compositions containing such grafts. The molding compositions are characterised by improved odoriferous behavior after processing.

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: A thermoplastic molding composition suitable for preparing molded articles having improved mechanical properties is disclosed. The composition contains A) a (co)polymer of at least one monomer selected from the group consisting of styrene, &agr;-methylstyrene, nuclear-substituted styrene, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic anhydride and N-substituted maleimide , and B) a graft polymer of B.1) at least one member selected from the group consisting of styrene, &agr;-methylstyrene, nuclear-substituted styrene, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic anhydride and N-substituted maleimide on B.2) a rubber having a glass transition temperature of ≦10° C. and C) a mixture of at least 3 components selected from I) metallic compounds, II) esters III) amides and IV) certain specified compounds exemplified by oil or wax.

Abstract: A process of preparing a graft polymer (e.g., an ABS graft copolymer), which involves determining the concentration of at least one reaction component during the course of the reaction by means of Raman spectroscopy, is disclosed. The process, more particularly, comprises: (a) synthesizing the graft polymer from a reaction mixture comprising reactive components (e.g., monomers such as styrene and acrylonitrile, and a graft base); (b) analyzing the reaction mixture, at intervals, during the synthesis of the graft polymer, by means of Raman spectra; (c) recording the results of the Raman spectra analysis; (d) determining the concentration of at least one of said reactive components (e.g., styrene) by means of spectral evaluation of the recorded Raman spectra; and (e) terminating the synthesis reaction of the graft polymer when the concentration of at least one of the reactive components has reached a predetermined concentration value.