Abstract: 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).

Abstract: A process for continuous production of copolyamides based on a lactam (I), a diamine (II) and a dicarboxylic acid (III) comprises reacting a mixture (IV) comprising a diamine (II), a dicarboxylic acid (III) and water in a first reaction zone at a pressure in the range from 1.3*105 to 2.5*105 Pa in the entry zone of the reaction zone and at a temperature above the melting point of polymer (V) to a conversion, based on the molar amounts of diamine (II) and dicarboxylic acid (III), of at least 80% to form a polymer (V), reacting a mixture (VI) comprising lactam (I) and water in a second reaction zone at a pressure in the range from 5*105 to 40*105 Pa and at a temperature above the melting point of polymer (VII) to a conversion, based on the molar amount of lactam (I), of at least 80% to form a polymer (VII), then reacting polymer (V) and polymer (VII) with each other in a third reaction zone at a pressure in the range from 1*105 to 1.

Abstract: 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).

Abstract: The disclosure is a process for preparing polyamides by concentrating the wash water extract from the extraction of polyamide to an extractables content of not more than 85% by weight, adding fresh lactam down to a water content of from 0.5 to 13% by weight, and effecting at least one adiabatic expansion during the polymerization.

Abstract: In a process for producing polyamides by polymerization of lactams in the presence of metal oxides as heterogeneous catalysts, the metal oxides are used in a form which permits mechanical removal from the reaction mixture and are removed from the reaction mixture in the course of or on completion of the polymerization.

Abstract: A process for continuous extraction of polyamide particles using a recirculating extractant in a vertical extraction column that is divided into two zones comprises treating the polyamide with an aqueous extractant comprising from 40 to 95% by weight of &egr;-caprolactam in a first zone at from 100 to 140° C., and then effecting an aftertreatment with water in a second zone. The caprolactam can then be extracted in a conventional manner. The process provides for economical production of polyamide having a low dimer content.

Abstract: A process for continuous extraction of polyamide particles in an essentially vertical extraction column using an aqueous extractant comprises using an extraction column that is divided into two zones and performing an extraction with a recirculating 15-40% strength by weight aqueous &egr;-caprolactam solution in the first zone and then with countercurrent water at a from 5 to 40° C. lower temperature in the second zone. The process provides for economical extraction of polyamides with a low level of monomers and oligomers.

Abstract: The molding composition comprises components A, B and, if desired, components C to E, the total weight of which is 100% by weight: a: as component A, from 5 to 95% by weight of a random copolyamide made from a1: from 95.1 to 99.9% by weight of component A1 made from equimolar amounts of at least one linear aliphatic diamine and at least one linear aliphatic dicarboxylic acid a2: from 0.1 to 4.

Abstract: A process for preparing a polyamide by reacting at least one aminonitrile with water comprises: (1) reacting at least one aminonitrile with water at a temperature from 100 to 360° C. and a pressure from 0.1 to 35×106 Pa to obtain a reaction mixture, (2) further reacting the reaction mixture at a temperature from 150 to 400° C. and a pressure which is lower than the pressure in step 1, the temperature and the pressure being selected so as to obtain a first gas phase and a first liquid or a first solid phase or a mixture of first solid and first liquid phase, and the first gas phase is separated from the first liquid or the first solid phase or from the mixture of first liquid and first solid phase, and (3) admixing the first liquid or the first solid phase or the mixture of first liquid and first solid phase with a gaseous or liquid phase comprising water at a temperature from 150 to 360° C. and a pressure from 0.1 to 30×106 Pa to obtain a product mixture.

Abstract: Biodegradable polyesters based onA) 95-99.99 mol % of at least one polyester A containing as monomeric building blocks of an acid component comprisinga.sub.11) 20-95 mol % of at least one aliphatic or cycloaliphatic dicarboxylic acid or its ester-forming derivative anda.sub.12) 5-80 mol % of at least one aromatic dicarboxylic acid or its ester-forming derivative andat least one dihydroxy compound or at least one amino alcohol or their mixtures, andB) 0.01-5 mol % of a mixture comprising mono-, bi-, tri-, tetra- and higher-nuclear isocyanurates or corresponding compounds containing two, three or four functional groups capable of reacting with the end groups of polyester A, or mixtures of the isocyanurates and the corresponding compounds,as well as molding compositions comprising said polyesters, their manufacture and their use in the manufacture of moldings, filsm, fibers and coatings.

Abstract: Thermoplastic molding compositions compriseA) from 5 to 97.9% by weight of a vinylaromatic polymer with syndiotactic structure,B) from 2 to 90% by weight of a low-viscosity polyamide with a viscosity number VN in the range from 50 to 150 ml/g andC) from 0.1 to 50% by weight of a polar-group-modified polyphenylene ether.

Abstract: Biodegradable polymers comprising a polyether ester P1 obtained by reactinga first mixture of20-95 mol% of adipic acid or ester-forming derivatives thereof or mixtures thereof,5-80 mol% of terephthalic acid or ester-forming derivatives thereof or mixtures thereof, and0-5 mol% of a compound containing sulfonate groups,and a second mixture of15-99.8 mol% of a dihydroxy compound selected from the group consisting of C.sub.2 -C.sub.6 -alkanediols and C.sub.5 -C.sub.10 -cycloalkanediols,85-0.2 mol% of a dihydroxy compound IHO--?(CH.sub.2).sub.n --O!.sub.m --H(n=2, 3 or 4, m=2-250)with0-5 mol%, based on the first mixture, of a compound D having at least three groups capable of ester formation,and a bisoxazoline C1, their preparation and their use in the manufacture of biodegradable molding materials.

Abstract: Biodegradable polyesters having a molecular weight (M.sub.n) of from 5000 to 50,000 g/mol (measured by gel permeation chromatography), a viscosity number of from 30 to 350 g/ml (measured in 50:50 by weight of o-dichlorobenzene/phenol at a concentration of 0.5% by weight of polyester at 25.degree. C.), and a melting point of from 50 to 170.degree. C., and having both hydroxyl and carboxyl end groups, the molar ratio of carboxyl end groups to hydroxyl end groups being greater than one, which is obtained by reacting a mixture consisting essentially ofa.sub.1) a mixture consisting essentially offrom 45 to 80 mol % of adipic acid or ester-forming derivatives thereof, or mixtures thereof,from 20 to 55 mol % of terephthalic acid or ester-forming derivatives thereof, or mixtures thereof, andfrom 0 to 5 mol % of a sulfonate compound,where the sum of the individual mole percentages is 100 mol %, anda.sub.2) a dihydroxy compound selected from the group consisting of C.sub.2 -C.sub.6 -alkanediols and C.sub.5 -C.sub.

Abstract: Thermoplastic molding materials containA) from 4 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 components a.sub.1) to a.sub.4) together giving 100%, andB) from 4 to 95% by weight of a polyolefin homo- or copolymer or a mixture thereof,C) from 1 to 20% by weight of a compatibilizer,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 components A to F together giving 100%.

Abstract: Thermoplastic molding materials containA) from 1 to 99% by weight of a 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 25 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 components a.sub.1) to a.sub.4) together giving 100%,B) from 1 to 99% by weight of an aromatic polycarbonate,C) from 0 to 30% by weight of a polymeric component having OH groups,D) from 0 to 60% by weight of fibrous or particulate fillers or of a mixture thereof,E) from 0 to 40% by weight of rubber impact modifiers andF) from 0 to 40% by weight of conventional additives and processing assistants.

Abstract: Thermoplastic molding materials containA) from 1 to 99% by weight of a 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 25 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 components a.sub.1) to a.sub.4) together giving 100%,B) from 1 to 99% by weight of a polyetherimide,C) from 0 to 30% by weight of a polymeric component having OH groups,D) from 0 to 60% by weight of fibrous or particulate fillers or mixtures thereof,E) from 0 to 40% by weight of rubber impact modifiers andF) from 0 to 40% by weight of conventional additives and processing assistants.

Abstract: Branched polyamides are prepared by mixingA) from 10 to 99.7% by weight of a melt of a polyamide prepolymer having a viscosity number of from 40 to 90 ml/g withB) from 0.3 to 6% by weight of a polybasic carboxylic acid, where the number n of the free carboxylic acid groups is 3.ltoreq.n.ltoreq.10, and alsoC) from 0 to 80% by weight of further additives and processing aids,where the percentages by weight of the components A) to C) add up to 100%, and subsequently further condensing the mixture in the solid phase.

Abstract: Thermoplastic molding materials containA) from 5 to 94% by weight of a partly aromatic, semicrystalline copolyamide composed essentially 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 components a.sub.1) to a.sub.4) together giving 100% andB) from 5 to 94% by weight of an ASA or ABS or SAN polymer or of a C.sub.1 -C.sub.18 -alkyl ester of (meth)acrylic acid or of a mixture thereof,C) from 1 to 30% by weight of an adhesion promoter which contains from 0.

Abstract: Thermoplastic molding materials containA) from 1 to 98.5% by weight of a partly aromatic copolyamide,B) from 1 to 98.5% by weight of a polymethacrylimide,C) from 0.5 to 30% by weight of a polymeric component having OH groups,D) from 0 to 60% by weight of fibrous or particulate fillers or mixtures thereof,E) from 0 to 40% by weight of rubber impact modifiers andF) from 0 to 40% by weight of conventional additives and processing assistants.

Abstract: Partly aromatic semicrystalline thermoplastic polyamide molding compositions containA) from 40 to 100% by weight of a 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 components a.sub.1) to a.sub.4) together giving 100%, andB) from 0 to 50% by weight of a fibrous or particulate filler,C) from 0 to 30% by weight of an elastomeric polymer andD) from 0 to 30% by weight of conventional additives and processing assistants,the percentages by weight of components A) to D) together giving 100%.