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:
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:
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
摘要:
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. The multi-stage polymerization is conducted such that: M:MWR (first stage)≦M:MWR (second stage)
摘要:
Thermoplastic moulding materials containing A. 15 to 80 parts by weight of a thermoplastic polycarbonate or polyester carbonate, and B. 4 to 40 parts by weight of a graft polymer of B.1 20 to 60 weight % of one or more monomers on B.2 40 to 80 weight % of one or more graft bases having glass transition temperatures
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:
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 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:
ABS type thermoplastic moulding compounds obtainable by A) producing a rubber latex with an average particle diameter d.sub.50 of 30 to 160 nm and a gel content of 75 to 100 wt. % B) emulsion polymerization of an amount of butadiene and optionally up to 50 wt. % (with reference to the total amount of monomer in stage B) of a comonomer in the presence of the rubber obtained in stage A, such that a rubber latex (B) with an average particle diameter d.sub.50 =220 to 330 nm and a gel content of 25 to 70 wt. % is produced, C) emulsion polymerization of 40 to 95 parts by wt. of a mixture of styrene and acrylonitrile, which optionally contains up to 50 wt. % (with reference to the total amount of monomers used in stage C) of one or more comonomers, in the presence of 5 to 60 parts by wt. (with reference to the solids) of the rubber obtained in stage B by introducing the monomer in such a way that 55 to 90 wt. % of the monomers are added within the first half of the total monomer introduction time, and D) mixing the polymer obtained in stage C, preferably after first converting it into a powder, with at least one thermoplastic vinyl resin.