Abstract: The present invention relates to a process for producing a polymer film (P) comprising at least one copolyamide by extrusion of the copolyamide through a ring die and subsequent stretching of the tube thus obtained by blowing in air. The present invention further relates to the polymer film (P) obtainable by the process of the invention and to a process for packing foods.

Abstract: The invention relates to a method for synthesizing a polyamide, in which method an aqueous solution is sprayed onto the polyamide before and/or during a solid-state post-condensation process. The aqueous solution comprises at least a first compound, selected from the group comprising phosphoric acid, fully neutralized salts of phosphoric acid, partially neutralized salts of phosphoric acid, and mixtures thereof, and a second compound, selected from the group comprising an acid, an anhydride, a lactone, ammonia, an amine, and mixtures thereof, with the stipulation that the second compound is not phosphoric acid and is not phosphoric acid anhydride. The spraying occurs at a temperature that lies below the boiling point of water. A polyamide that can be produced by means of the method according to the invention can be used in particular to produce films, monofilaments, fibers, threads, or textile sheet materials.

Abstract: The invention relates to a method for producing polyamide composite materials containing silicon, comprising the copolymerisation of: a) at least one silicon compound (SV) having at least one silicon atom, said silicon atom having at least one lactamyl group of formula (A) bonded by means of the nitrogen atom thereof; b) the method also comprises copolymerisation with at least one comonomer (CM) that is selected from among ammonium salts of dicarboxylic acids, amino acids, amino acid amides and lactams. In formula (A), m represents a whole number between 1 and 11, in particular in between 2 and 9, and specifically 3, and # represents the connection to the silicon atom of the compound (SV).

Abstract: A method produces a polyamide having an extractable fraction of oligomer of from 2 to 10 percent. The method includes introducing a monomer into a reactor and polymerizing the monomer to form a first intermediate having an extractable fraction of oligomer of greater than 10 percent, wherein the oligomer is a compound of 2 to 20 units of the monomer. The method includes transferring the first intermediate from the reactor into an extractor and introducing water into the extractor to form a second intermediate having an extractable fraction of oligomer that is less than the extractable fraction of the first intermediate, wherein the water is introduced at a temperature of less than 100° C. and wherein the water includes 0.1 to 3.0 weight percent of a plasticizer. Moreover, the method includes transferring the second intermediate into a dryer and applying air at a temperature of less than 125° C.

Abstract: Process for producing polyamides that are stable during processing, by treating the polyamide during the solid-phase postcondensation process with a gas which comprises carrier gas (inert gas), water, and acid, or an anhydride or lactone or a mixture of these or, respectively, comprises ammonia, or amine, or a mixture of these, at a temperature from 130 to 200° C. and at a pressure of from 0.01 to 10 bar.

Abstract: The invention relates to a method for producing polyamide composite materials containing silicon, comprising the copolymerisation of: a) at least one silicon compound (SV) having at least one silicon atom, said silicon atom having at least one lactamyl group of formula (A) bonded by means of the nitrogen atom thereof; b) the method also comprises copolymerisation with at least one comonomer (CM) that is selected from among ammonium salts of dicarboxylic acids, amino acids, amino acid amides and lactams. In formula (A), m represents a whole number between 1 and 11, in particular in between 2 and 9, and specifically 3, and # represents the connection to the silicon atom of the compound (SV).

Abstract: The invention relates to a method for synthesizing a polyamide, in which method an aqueous solution is sprayed onto the polyamide before and/or during a solid-state postcondensation process. The aqueous solution comprises at least a first compound, selected from the group comprising phosphoric acid, fully neutralized salts of phosphoric acid, partially neutralized salts of phosphoric acid, and mixtures thereof, and a second compound, selected from the group comprising an acid, an anhydride, a lactone, ammonia, an amine, and mixtures thereof, with the stipulation that the second compound is not phosphoric acid and is not phosphoric acid anhydride. The spraying occurs at a temperature that lies below the boiling point of water. A polyamide that can be produced by means of the method according to the invention can be used in particular to produce films, monofilaments, fibers, threads, or textile sheet materials.

Abstract: Process for producing polyamides that are stable during processing, by treating the polyamide during the solid-phase postcondensation process with a gas which comprises carrier gas (inert gas), water, and acid, or an anhydride or lactone or a mixture of these or, respectively, comprises ammonia, or amine, or a mixture of these, at a temperature from 130 to 200° C. and at a pressure of from 0.01 to 10 bar.

Abstract: A process for producing polyamides from the corresponding monomers and/or prepolymers comprises the steps of (a) reacting the monomers and/or prepolymers and optionally further components under polyamide-forming reaction conditions to form polyamide, (b) treating the polyamide obtained in step (a) in a kneader above the melting temperature of the polyamide, (c) further processing the polyamide from step (b) into pellet, film, fiber or moldings, preferably pelletizing the polyamide, (d) extracting some or all unconverted monomers and any product dimers and oligomers and also optionally further components from the polyamide and/or drying the polyamide.

Abstract: Process for producing polyamides that are stable during processing, by treating the polyamide during the solid-phase postcondensation process with a gas which comprises carrier gas (inert gas), water, and acid, or an anhydride or lactone or a mixture of these or, respectively, comprises ammonia, or amine, or a mixture of these, at a temperature from 130 to 200° C. and at a pressure of from 0.01 to 10 bar.