摘要:
Nylons are prepared by a continuous process in which, in a precondensation zone, an aqueous solution of a salt of a dicarboxylic acid of 6 to 18 carbon atoms and a diamine of 6 to 18 carbon atoms is heated to 250.degree.-300.degree. C. under superatmospheric pressure, with simultaneous vaporization of water and formation of a prepolymer, the prepolymer and the vapor are separated, and the former is fed into a polycondensation zone and condensed under superatmospheric pressure of from 1 to 10 bar and at from 250.degree. to 300.degree. C., wherein the aqueous salt solution is condensed under superatomspheric pressure of from 1 to 10 bar in the first third of the tubular precondensation zone provided with baffles, until the degree of conversion is not less than 93%, and the prepolymer and the vapor phase are brought into intimate contact with one another in the remaining two thirds of the precondensation zone.
摘要:
A process for removing volatile constituents from polymer melts or pastes, wherein the polymer or paste containing the volatile constituents is passed, with continuous formation of fresh surfaces, through one or more zones in which the volatile constituents evaporate, and the volatile constituents are removed from the zone or zones in which they evaporate through, in each case, a plurality of porous orifices, and an apparatus for carrying out said process.
摘要:
Polylactams are prepared continuously by a process in which a lactam containing from 1 to 25% by weight of water is heated in a prepolymerization zone under a pressure of from 1 to 10 bar at from 220.degree. to 280.degree. C. for 1 to 10 minutes, water being vaporized at the same time, with the proviso that the degree of conversion on emergence from the prepolymerization zone is not less than 85%, the prepolymer and the vapor are separated continuously, and the prepolymer is passed into a polymerization zone and is polymerized further under superatmospheric pressure at from 240.degree. to 290.degree. C.
摘要:
Nylons are prepared by a continuous process in which, in an evaporator zone, an aqueous solution of a salt of a dicarboxylic acid of 6 to 18 carbon atoms and a diamine of 6 to 18 carbon atoms is heated to 250.degree.-300.degree. C. under superatmospheric pressure, with simultaneous vaporization of water and formation of a prepolymer, the prepolymer and the vapors are separated continuously, the vapors are rectified and the entrained diamines are recycled, and the prepolymer is fed to a polycondensation zone and subjected to polycondensation under superatmospheric pressure of from 1 to 10 bar and at from 250.degree. to 300.degree. C., wherein the aqueous salt solution is heated under superatmospheric pressure of from 1 to 10 bar during a residence time of less than 60 seconds, with the proviso that, on leaving the evaporator zone, the degree of conversion is not less than 93% and the water content of the prepolymer is not more than 7% by weight.
摘要:
Copolyamides are prepared by a continuous process in which(a) an aqueous solution of salts of equimolar amounts of diamines and dicarboxylic acids is passed, under superatmospheric pressure and with simultaneous evaporation of water, through a tubular precondensation zone with formation of a vapor phase and a prepolymer at above the melting point of the prepolymer,(b) the vapor phase is separated from the prepolymer melt,(c) the vapor phase is separated in a column into steam and an aqueous diamine solution, and the aqueous solution containing diamines is recycled to the polymerization,(d) the prepolymer melt is mixed with molten caprolactam at polyamide-forming temperatures, and(e) the mixture of prepolymer and caprolactam is passed downward through a vertical polymerization tube at polyamide-forming temperatures and a copolyamide is obtained.
摘要:
An apparatus (1) is proposed for drying and heat-treating pellets with a stream of inert gas, wherein the apparatus has a cuboid base unit (2) with a feed (3) for the pellets in its upper part and an outlet (4) in its lower part, with a feed (5) on one lateral surface and with an exhaust base (6) on the opposite lateral surface of the cuboid base unit (2) for the stream of inert gas, and also with distribution and retention equipment (7, 8) in the region of the feed (5) and, respectively, of the exhaust (6) for the stream of inert gas, where each of these extends essentially over the entire vertical cross section of the cuboid base unit (2).
摘要:
Thermoplastic molding materials containA) from 5 to 95% by weight of a semicrystalline, partly aromatic copolyamide composed ofa.sub.1) from 30 to 44 mol % of units which are derived from terephthalic acid,a.sub.2) from 6 to 20 mol % of units which are derived from isophthalic acid,a.sub.3) from 43 to 49.5 mol % of units which are derived from hexamethylenediamine anda.sub.4) from 0.5 to 7 mol % of units which are derived from aliphatic cyclic diamines of 6 to 30 carbon atoms, the molar percentages of the components a.sub.1) to a.sub.4) summing to 100%,B) from 5 to 95% by weight of a copolymer of vinylaromatic compounds with .alpha.,.beta.-unsaturated dicarboxylic anhydrides and .alpha.,.beta.-unsaturated dicarboximides,C) from 0 to 90% by weight of an SAN, ABS or ASA polymer or of a polymer of a C.sub.1 -C.sub.18 -alkyl ester of (meth)acrylic acid or of a mixture thereof,D) from 0 to 20% by weight of an elastomeric polymer,E) from 0 to 50% by weight of a fibrous or particulate filler andF) from 0 to 30% by weight of conventional additives and processing assistants,the percentages by weight of the components A) to F) summing to 100 %.
摘要:
The invention is directed to molding materials containingA) from 1 to 99% by weight of polyarylene ethers having repeating units I ##STR1## where t and q may each be an integer 0, 1, 2 or 3,T, Q and Z may each be a chemical bond or --O--, --S--, --SO.sub.2 --, S.dbd.O, C.dbd.O, --N.dbd.N--, R.sup.a C.dbd.CR.sup.b -- or --CR.sup.c R.sup.d --, with the proviso that at least one of the groups T, Q and Z is --SO.sub.2 -- or C.dbd.O,R.sup.a and R.sup.b,R.sup.c and R.sup.d, andAr and Ar.sup.1 are as defined in the specification,B) from 1 to 99% by weight of copolyamides containingb.sub.1) from 30 to 44 mol % of units which are derived from terephthalic acid,b.sub.2) from 6 to 20 mol % of units which are derived from isophthalic acid,b.sub.3) from 43 to 49.5 mol % of units which are derived from hexamethylenediamine,b.sub.4) from 0.5 to 7 mol % of units which are derived from aliphatic cyclic diamines of 6 to 30 carbon atoms andb.sub.5) from 0 to 4 mol % of further polyamide-forming monomers which differ from b.sub.1) to b.sub.4),along with other optional additives.
摘要:
Thermoplastic molding compositions are obtainable by mixingA) from 0.5 to 5% by weight of a thermoplastic polyester elastomer andB) from 0 to 50% by weight of fibrous or particulate fillers or mixtures thereof into a melt ofC) from 40 to 99.5% by weight of a polyamide prepolymer having a viscosity number of from 40 to 80 ml/g and subsequent postcondensation in solid phase.
摘要:
Aromatic polycondensates are prepared in a continuous process froma) aromatic hydroxy-, thio- and/or amino-carboxylic acids,b) aromatic dihydroxy-, dithio-, diamino- and/or hydroxy-amino compounds,c) urea as an optional component andd) a molar amount equivalent to the sum of components b) and c) of aromatic dicarboxylic acids,by1. reacting components a), b), d) and optionally c) with lower fatty acid anhydrides in excess at from 140.degree. to 280.degree. C. with distillative removal of fatty acids and fatty acid anhydrides,2. passing the oligomer mixture downward through a perpendicular precondensation zone to form a two-phase mixture of prepolymers and vaporous fatty acids,3. separating the prepolymers from the vaporous fatty acids and4. condensing the prepolymer in a condensation zone to give a granulable polycondensate.