Abstract: The invention relates to a process for producing fiber-reinforced flat semifinished products based on a polyamide matrix, comprising the following steps: (a) saturation of textile structures with a mixture comprising molten lactam, catalyst, and optionally activator, (b) cooling of the saturated textile structures, and (c) finishing of the cooled textile structures to give the fiber-reinforced flat semifinished product. The invention further relates to a process for producing a component made of the fiber-reinforced flat semifinished product.

Abstract: The present invention relates to solid particles which comprise at least one lactam, and also at least one activator, and at least one catalyst, to a process for the production of these, and also to the use of these for the production of polyamide, and to a process for the production of polyamide.

Abstract: The invention relates to a process, comprising the following steps, for connecting two plastics elements to give a component, where a second plastics element is connected to a first plastics element by molding-on in a molding process or forming process: (a) inserting the first plastics element into a mold, where the first plastics element comprises at least one thermoplastic as matrix material, (b) introducing a plastics molding composition into the mold for molding the second plastics element, where the plastics molding composition comprises at least one thermoplastic having reactive groups or one mixture made of at least one thermoplastic and of a material having reactive groups which react chemically with reactive groups of the thermoplastic of the first plastics element.

Abstract: The invention relates to a process for producing moldings made of a fiber-reinforced polymer, comprising the following steps: (a) inserting a fiber structure into a mold and injecting a polymer precursor compound around the fiber structure or saturating a fiber structure with a polymer precursor compound and inserting the saturated fiber structure into a mold, where the viscosity of the polymer precursor compound is at most 2000 mPas, (b) polymerizing the polymer precursor compound to give the polymer, to produce the molding, (c) removing the molding from the mold as soon as the polymerization process has proceeded at least to the extent that the molding is in essence dimensionally stable.

Abstract: The present invention relates to a process for producing polyamides, preferably crosslinked polyamides, via anionic polymerization of lactams in the presence of an anionic catalyst and of a caprolactam-capped polyisocyanate, where said isocyanate comprises more than 3.5 capped isocyanate groups.

Abstract: The present invention relates to a process for preparing a composition comprising (A) at least one lactam, (B) at least one catalyst, (C) an activator from the group consisting of isocyanates, acid anhydrides, acyl halides, reaction products thereof with (A) and mixtures thereof, (D) at least one polyethyleneimine. The invention likewise relates to a composition comprising (i) 0.01 to 10 wt %, based on the sum total of components (A) and (D), of at least one polyethyleneimine, and (ii) 90 to 99.99 wt %, based on the sum total of components (A) and (D), of at least one lactam (A) and/or polyamide obtainable from (A).

Abstract: The present invention relates to a process for recycling multiphase moldings.

Abstract: The present invention relates to a process for preparing a polyamide based on dicarboxylic acids and diamines, comprising the following stages: A) providing an aqueous monomer mixture composed of dicarboxylic acids and diamines, where the molar ratio of dicarboxylic acids to diamines is adjusted such that, at the outlet of stage C), there is a molar deficiency of dicarboxylic acids or diamines of 1 to 10 mol%, based on the respective other component, B) transferring the aqueous mixture from stage A) into a continuous evaporator reactor in which diamines and dicarboxylic acids are converted at a temperature in the range from 100 to 370° C. and a pressure in the range from 1 to 50 bar, C) transferring the mixture from stage B) into a separator which is operated at a temperature in the range from 100 to 370° C.

Abstract: Semiaromatic, semicrystalline copolyamide molding compositions, comprising A) from 35 to 100% by weight of a copolyamide composed of a1) from 35 to 69% by weight of units which derive from hexamethylenediamine and from an aromatic dicarboxylic acid having from 8 to 16 carbon atoms, a2) from 31 to 65% by weight of units which derive from 3,3?-dimethyl-4,4?-diaminodicyclohexylmethane and from terephthalic acid, a3) from 0 to 30% by weight of units of a semicrystalline polyamide different from a1) and a2), B) from 0 to 65% by weight of further additives, where the total of the percentages by weight of A) and B) is 100%.

Abstract: The invention relates to a process for producing fiber-reinforced flat semifinished products (3) based on a polyamide matrix, comprising the following steps: (a) saturation of textile structures (15) with a mixture comprising molten lactam, catalyst, and optionally activator, (b) cooling of the saturated textile structures (25), and (c) finishing of the cooled textile structures to give the fiber-reinforced flat semifinished product (3). The invention further relates to a process for producing a component made of the fiber-reinforced flat semifinished product.

Abstract: A process for crosslinking polyamides by reacting a compound of the general formula R1R2C?CR3—X in which R1, R2 and R3 are each independently hydrogen or an organic radical with a lactam A at a temperature of (?30) to 150° C., and then reacting with a lactam B, a catalyst and an activator at a temperature of 40 to 240° C.

Abstract: The present invention relates to a novel process for the anionic polymerization of lactam monomers.

Abstract: The present invention relates to open-cell foams filled with polyamide and also to a production process therefor.

Abstract: A process for producing an activated monomer composition comprising at least one lactam and/or lactone, one catalyst, and one activator permits storage of the resultant monomer composition, since this is stable with respect to polymerization. Said monomer composition is used inter alia in producing a polyamide molding via ring-opening, anionic polymerization.

Abstract: The invention relates to thermoplastic molding compositions comprising: A) from 10 to 89% by weight of a polyethylene terephthalate or polybutylene terephthalate, B) from 10 to 60% by weight of a fibrous reinforcing material with a fiber length of from 2 to 24 mm, C) from 1 to 20% by weight of at least one polyester based on aliphatic and aromatic dicarboxylic acids and on an aliphatic dihydroxy compound, D) from 0 to 40% by weight of further additives, where the entirety of components A) to D) is 100%. The invention further relates to the use of thermoplastic molding compositions for producing long-fiber-reinforced pellets and to the pellets thus obtainable. The invention further relates to the use of pellets of this type for producing moldings of any type with good notched impact resistance, and to the resultant moldings.

Abstract: The present invention relates to an improved pultrusion process for producing semifinished products based on polymers, in particular polyesters or polyamides, which comprises adding reactive chain extenders during the process of saturation (impregnation) of the fibers.

Abstract: The invention relates to thermoplastic molding compositions comprising A) from 10 to 89% by weight of a polyamide, B) from 10 to 60% by weight of a fibrous reinforcing material with fiber length from 3 to 24 mm, C) from 1 to 20% by weight of at least one polyolefin composed of ethylene or propylene or a mixture of these, where polar functional groups are excluded, D) from 0 to 5% by weight of at least one nanoparticulate oxide or oxide hydrate, or a mixture of these, of at least one metal or semimetal, with a number-average primary-particle diameter of from 0.5 to 50 nm, and with a hydrophobic particle surface, and E) from 0 to 40% by weight of further additives, where the entirety of components A) to E) gives 100%.

Abstract: Polyamides based on dicarboxylic acids and on diamines are produced in a batch process by 1) feeding the entire amount of monomer composed of dicarboxylic acids, of diamines, and, if appropriate, of further polyamide-forming monomers, in the desired stoichiometry, in a closed stirred-tank reactor, 2) heating the monomer mixture in the stirred-tank reactor, with stirring, and with setting of a certain pressure, to a desired reaction temperature for the production of a prepolymer, 3) if appropriate, completely or partially depressurizing the reaction mixture from stage 2), 4) if appropriate, carrying out further thermal treatment of the reaction mixture from stage 2) or 3), and 5) reacting the reaction mixture from stage 2), 3), or 4) in the melt in a vented extruder for further increase of the molecular weight, with discharge of water vapor, and without use of additional polyamide-forming monomers or of polyamides.

Abstract: For the anionic polymerization of lactams: (a) (i) a catalyst capable of creating a lactamate and (ii) a regulator chosen from amides of formula R1-NH—CO-R2, in which R1 can be substituted by an R3-CO—NH— or R3-0— radical and in which R1, R2 and R3 denote an aryl, alkyl or cycloalkyl radical, are dissolved in the molten lactam, (a1) the solution from stage (a) is cooled, optionally to the solid state in a form which can be divided, (a2) the product from stage (a1) is optionally reheated to a temperature below the polymerization temperature of the lactam, (a3) optionally, the product from stage (a1) is reheated and is maintained at a temperature between the melting temperature of the lactam and 15° C. above, and (b) the produce from any one of stages (a1), (a2) or (a3) is introduced into a mixing device or mold and is then heated to a temperature sufficient to obtain the bulk polymerization of the lactam.

Abstract: For the anionic polymerization of lactams: (a) (i) a catalyst capable of creating a lactamate and (ii) a regulator chosen from amides of formula R1-NH—CO—R2, in which R1 can be substituted by an R3-CO—NH— or R3-0— radical and in which R1, R2 and R3 denote an aryl, alkyl or cycloalkyl radical, are dissolved in the molten lactam, (a1) the solution from stage (a) is cooled, optionally to the solid state in a form which can be divided, (a2) the product from stage (a1) is optionally reheated to a temperature below the polymerization temperature of the lactam, (a3) optionally, the product from stage (a1) is reheated and is maintained at a temperature between the melting temperature of the lactam and 15° C. above, and (b) the produce from any one of stages (a1), (a2) or (a3) is introduced into a mixing device or mold and is then heated to a temperature sufficient to obtain the bulk polymerization of the lactam.