摘要:
The invention relates to a process for pelletizing polymer melts, at above ambient pressure, in a pelletizing chamber into which a cutting apparatus has been inserted. In a first step, the pelletizing chamber is flooded with a gas which is inert toward the polymer melt and whose pressure is that at which the pelletizing process is carried out. The polymer melt is then injected into the pelletizing chamber. Finally, the gas is displaced from the pelletizing chamber via a liquid as soon as the polymer melt begins to flow through the cutting apparatus, this melt being cut into pellets.
摘要:
The invention relates to a process for pelletizing polymer melts, at above ambient pressure, in a pelletizing chamber into which a cutting apparatus has been inserted. In a first step, the pelletizing chamber is flooded with a gas which is inert toward the polymer melt and whose pressure is that at which the pelletizing process is carried out. The polymer melt is then injected into the pelletizing chamber. Finally, the gas is displaced from the pelletizing chamber via a liquid as soon as the polymer melt begins to flow through the cutting apparatus, this melt being cut into pellets.
摘要:
Thermoplastic molding materials which are stable at high temperatures and are based on polyaryl ether sulfones and, if required, polyether ketones have a content of alkali metal salts of not more than 100 ppm, based on total polymer.
摘要:
Particulate polymers of aromatic diols I and aromatic dihalogen compound II are prepared by(A) producing a plurality of liquid jets from a solution of the polymer by means of a nozzle,(B) causing the liquid jet to divide into particles of equal size,(C) precipitating the drops by introduction into a precipitation bath and(D) removing solvent residues and other impurities.
摘要:
Thermoplastic molding materials of A) from 72 to 88.5% by weight of a thermoplastic styrene or &agr;-methylstyrene polymer or copolymer, B) from 10 to 20% by weight of a first graft polymer having an average particle diameter d50 from 400 to 600 nm, having an n-butyl acrylate based rubber-elastic graft core, and a styrene or &agr;-methylstyrene (co)polymer graft shell, C) from 1.5 to 8% by weight of a second graft polymer having a bimodal particle size distribution, the average particle diameter d50 being from 25 to 200 nm and from 350 to 550 nm, having a butadiene or isoprene polymer or copolymer based rubber-elastic graft core, and a styrene or &agr;-methylstyrene (co)polymer graft shell, D) from 0 to 50% by weight of conventional additives, where the graft polymers B) and C) constitute from 11.5 to 25% by weight of components A), B) and C), and components A) to D) amount to 100% by weight.
摘要:
A thermoplastic molding composition having little intrinsic color is produced from a graft copolymer and a thermoplastic polymer. The graft copolymer is produced from a soft elastomeric particulate graft base obtained by polymerization of a conjugated diene alone or with a small amount of a monoethylenically unsaturated monomer, upon which is grafted a vinylaromatic monomer and acrylonitrile and optionally another monoethylenically unsaturated monomer. The thermoplastic polymer is a copolymer of a vinylaromatic monomer and acrylonitrile and optionally an additional monoethylenically unsaturated monomer. The thermoplastic molding composition has a low level of intrinsic color coupled with good mechanical properties and can be processed by, for example, extrusion, injection molding, calendaring, blow molding, compression molding, or sintering.
摘要:
Flame-retardant thermoplastic molding compositions comprise A) at least one polyphenylene ether, andB) at least one vinylaromatic polymer, wherein the thermoplastic molding composition includesC) at least one oligomeric phosphorus compound as flame retardant andD) a mixture ofD.sub.1) at least one sterically hindered phenol andD.sub.2) at least one phosphonite as stabilizer,and are used to produce fibers, films and shaped articles.
摘要:
In the preparation of a rubber-modified molding material, in a first stage, a first mixture (A) contains at least one alkyl acrylate or methacrylate (a) of the formula (I) ##STR1## where R.sup.1 is hydrogen or methyl and R.sup.2 is alkyl of 1 to 32 carbon atoms, at least one first monomer (b) which forms free radicals on thermal decomposition and, if required, a second monomer (c) or a plurality thereof is polymerized, preferably with free radicals, to give a rubber (B),in a second stage, the resulting rubber (B) is mixed with a third monomer (d) or a plurality thereof, preferably dissolved or swollen therein, to form a second mixture (C), andin a third stage, the second mixture (C) is polymerized with free radicals to give the rubber-modified molding material (D).
摘要:
Thermoplastic molding materials contain A) from 5 to 97.9% by weight of a polyphenylene ether B) from 1 to 93.9% by weight of a vinylaromatic polymer C) from 1 to 50% by weight of an elastomeric polymer D) from 0.1 to 10% by weight of a stabilizer mixture comprising d1) at least one sterically hindered phenol, d2) at least one phosphonite and d3) at least one alkyl aryl phosphite, E) from 0 to 70% by weight of a polyamide and F)from 0 to 60% by weight of further additives and processing assistants, the sum of the percentages by weight of components A) to F) being 100%.
摘要:
Flame-retardant thermoplastic molding materials containing A) at least one polyphenylene ether and B) at least one vinyl aromatic polymer, comprise C) as a flameproofing agent, a mixture of C1) at least one oligophosphonate or oligophosphate compound and C2) at least one phosphine oxide.