摘要:
Thermoplastic moulding compositions ofA. 90 to 30 parts by weight of a copolymer prepared by solution or bulk polymerization of a.sub.1 30 to 45% by weight of .alpha.-methylstyrene, a.sub.2 26 to 35% by weight of acrylonitrile and a.sub.3 44 to 20% by weight of styrene and/or p-methylstyrene, and with a content of incorporated acrylonitrile of 27-30% by weight,B. 5 to 60 parts by weight of a random copolymer of b.sub.1 18 to 24% by weight of maleic anhydride and b.sub.2 82 to 76% by weight of styrene and/or p-methylstyrene andC. 5 to 40 parts by weight of a graft polymer of 70 to 30% by weight of a mixture of c.sub.1 a vinylaromatic and/or C.sub.1 -C.sub.4 -alkyl and c.sub.2 acrylonitrile, on 30 to 70% by weight of a rubber with a glass transistion temperature of less than -10.degree. C.
摘要:
A process for the continuous processing of vinyl polymer latices to produce thermoplastically processible vinyl polymer powder by coagulating a stream of a vinyl polymer latex by the addition of a stream of a coagulant with intensive mixing and shearing in a cascade of vessels at an average residence time per vessel of 10 to 60 minutes and at temperatures from 50 to 120.degree. C., volatile auxiliary substances and residual monomers in the polymer being optionally removed by steam distillation and part of the serum separated from the vinyl polymer being added to the stream of coagulant.
摘要:
A process for processing polymers of the ABS type present in emulsion form and effectively stabilized against oxidative attack with optionally continuous recovery and direct reuse of untreated monomers, wherein a combination of at least one phenolic antioxidant having a molecular weight above 300 without ester groups in the molecule and at least one sulfur-containing co-stabilizer having a molecular weight above 500 without ester groups in the molecule is added to the ABS polymer emulsion for stabilization against oxidative degradation.
摘要:
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.
摘要:
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.
摘要:
The present invention provides polymer compositions of special graft rubber polymers, in the production of which are employed rubbers with defined particle diameters obtained by seed polymerization using seed latex particles with defined particle diameters.
摘要:
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.
摘要:
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. The polymers so obtained have no negative effects at all on other properties