Abstract: The present invention relates to a process for producing a highly concentrated aqueous solution of a salt of a diamine and dicarboxylic acid by using a pre-salt aqueous solution having a high concentration of diacid/diamine salt and an excess of dicarboxylic acid; and adding additional diamine to obtain the final diacid/diamine solution. The final diacid/diamine salt solution obtained is suitable for the manufacture of a polyamide such as for example polyamide 66.

Abstract: The present invention relates to a process for the production of an aqueous solution of a salt of a diamine and a diacid for the manufacture of polyamide.

Abstract: The present invention relates to a polyamide ester obtainable by polymerizing a polyamide salt, a polyhydric alcohol containing at least three hydroxyl groups, a dicarboxylic acid, and a chain limiting agent, wherein the polyhydric alcohol and the dicarboxylic acid are used in such amounts that the molar ratio of the excess of carboxylic acid groups from the dicarboxylic acid used to the molar equivalent amount of hydroxyl groups from the polyhydric alcohol used is at least 0.1.

Abstract: The present invention relates to a novel process for the production of a copolyamide comprising a polymerization product of hexamethylene diamine, adipic acid and terephthalic acid. A process for the production of a copolyamide comprising less than 50 mol % of units of hexamethylene terephthalamide may include (a) introducing an aqueous solvent and the monomers adipic acid, terephthalic acid and hexamethylene diamine, or salts thereof, into an evaporator to obtain a mixture; (b) concentrating the mixture obtained in step (a) in the evaporator by evaporation of at least part of the solvent, to obtain a concentrated mixture; (c) transferring the concentrated mixture obtained in step (b) into an autoclave; (d) polymerizing the monomers in the autoclave at a pressure of at least 1.

Abstract: The present invention relates to a process for the production of an aqueous solution of a salt of a diamine and a diacid for the manufacture of polyamide.

Abstract: The invention pertains to A polyannide composition [composition (C)] comprising: —from 20 to 95% wt of at least one polyamide [polyamide (A)]; —from 1 to 30% wt of at least one branched polyamide different from polyamide (A), said branched polyamide comprising recurring units derived from polycondensation of a mixture [mixture (B)] comprising: —at least one polyamine monomer comprising at least three amine functional groups selected from the group consisting of secondary amine group of formula —NH— and primary amine group of formula -MH2 [monomer (FN)], and—?-caprolactam (or derivates thereof); said branched polyamide possessing a concentration of amine end groups (AEG) and a concentration of carboxylic end groups (CEG) such that the difference AEG?CEG is of at least 100 meq/kg [polyamide (B)]; and—from 0.01 to 3.

Abstract: The present invention relates to a method for preparing polyamide granules. This method comprises, in particular, steps of extruding the polymer, cooling and cutting the extruded material, and a step of cooling the granules. The method of the invention is simple and quick to implement.

Abstract: The invention pertains to A polyannide composition [composition (C)] comprising: —from 20 to 95% wt of at least one polyamide [polyamide (A)]; —from 1 to 30% wt of at least one branched polyamide different from polyamide (A), said branched polyamide comprising recurring units derived from polycondensation of a mixture [mixture (B)] comprising: —at least one polyamine monomer comprising at least three amine functional groups selected from the group consisting of secondary amine group of formula —NH— and primary amine group of formula -MH2 [monomer (FN)], and —?-caprolactam (or derivates thereof); said branched polyamide possessing a concentration of amine end groups (AEG) and a concentration of carboxylic end groups (CEG) such that the difference AEG?CEG is of at least 100 meq/kg [polyamide (B)]; and —from 0.01 to 3.

Abstract: Modified polyamides are prepared by polymerization of diacid and diamine monomers in the presence of a multifunctional compound having either at least three acid functions or at least three basic functions and, optionally, a monofunctional compound having either an acid function or a basic function. These polyamides can be formulated into molding compositions which can be converted into useful shaped articles.

Abstract: A process is described for producing a polyamide from at least one diacid and from at least one diamine. The process can include introducing a lactam and/or an amino acid after a step of concentrating an aqueous solution of a salt of diacid and diamine.

Abstract: The present invention relates to a method for preparing polyamide granules. This method comprises, in particular, steps of extruding the polymer, cooling and cutting the extruded material, and a step of cooling the granules. The method of the invention is simple and quick to implement.

Abstract: A method for manufacturing a solution of a diacid and diamine salt for manufacturing polyamide is described. A method for manufacturing an aqueous solution of diacid and diamine salts produced by mixing at least two diacids and at least one diamine, with a weight concentration of salt between 40% and 70%, including, in a first step, preparing an aqueous solution of diacid(s) and diamine(s) with a diacid/diamine mole ratio of less than 1 using one diacid and one diamine, and in a second step, adjusting the mole ratio of diacids/diamine(s) to a value of between 0.9 and 1.1, and fixing the weight concentration of salt by adding another diacid and, optionally, additional water and/or diamine is also described.

Abstract: Solutions of a salt of a diamine and of a diacid, more particularly concentrated solutions of hexamethylene diammonium adipate salt (“nylon salt”), useful starting materials for the production of polyamides, more specifically of PA66, are prepared by mixing a diacid and a diamine, at a salt concentration by weight of from 50% to 80%, in a first stage, to provide aqueous solutions of diacid and diamine having a diacid/diamine molar ratio of greater than 1.1 and, in a second stage, adjusting the diacid/diamine molar ratio, by adding diamine, to a value of from 0.9 to 1.1, preferably from 0.99 to 1.01, and in fixing the salt concentration by weight by, optionally, adding water thereto.

Abstract: Polyamides, e.g., polyhexamethylene adipamide, are continuously produced via the following stages: Stage 1: into and through a reactor, polycondensing a liquid stream which contain the polyamide monomer(s) at a pressure P1 greater than atmospheric pressure, the stream of material at the outlet of the reactor including a vapor phase which contains steam and a liquid phase which at least contains the product of polycondensation; Stage 2: feeding the outlet stream of material into a chamber, evacuating at least a portion of the vapor phase therefrom and recovering at least the liquid phase which at least contains the product of polycondensation, the pressure P2 in the chamber being regulated at a set value such that it is greater than atmospheric pressure and the residence time of said liquid phase in the chamber being less than 5 minutes; and Stage 3: pressure reducing at least the liquid phase which at least contains the stream of polycondensation product recovered during Stage 2.

Abstract: A method for making polyamide is described. More particularly, a method for making a polyamide from at least one diacid and one diamine, that includes a step of concentrating an aqueous solution of diacid and diamine salt up to a salt weight concentration higher than 85%, and a polymerization step up to a desired polymerization degree is described.

Abstract: The present invention relates to a process for the manufacture of polyamide. The invention relates more particularly to a process for the manufacture of polyamide from at least one diacid and from at least one diamine, comprising the introduction of lactam and/or of amino acid after a stage of concentration of an aqueous solution of salt of diacid and diamine.

Abstract: A method for manufacturing a solution of a diacid and diamine salt for manufacturing polyamide is described. A method for manufacturing an aqueous solution of diacid and diamine salts produced by mixing at least two diacids and at least one diamine, with a weight concentration of salt between 40% and 70%, including, in a first step, preparing an aqueous solution of diacid(s) and diamine(s) with a diacid/diamine mole ratio of less than 1 using one diacid and one diamine, and in a second step, adjusting the mole ratio of diacids/diamine(s) to a value of between 0.9 and 1.1, and fixing the weight concentration of salt by adding another diacid and, optionally, additional water and/or diamine is also described.

Abstract: A method for making polyamide is described. More particularly, a method for making a polyamide from at least one diacid and one diamine, that includes a step of concentrating an aqueous solution of diacid and diamine salt up to a salt weight concentration higher than 85%, and a polymerization step up to a desired polymerization degree is described.

Abstract: Novel modified polyamides are prepared by polymerization of diacid and diamine monomers in the presence of certain multifunctional and, optionally, monofunctional compounds; such novel polyamides are formulated into molding compositions which can be converted into useful shaped articles.

Abstract: Solutions of a salt of a diamine and of a diacid, more particularly concentrated solutions of hexamethylene diammonium adipate salt (“nylon salt”), useful starting materials for the production of polyamides, more specifically of PA66, are prepared by mixing a diacid and a diamine, at a salt concentration by weight of from 50% to 80%, in a first stage, to provide aqueous solutions of diacid and diamine having a diacid/diamine molar ratio of greater than 1.1 and, in a second stage, adjusting the diacid/diamine molar ratio, by adding diamine, to a value of from 0.9 to 1.1, preferably from 0.99 to 1.01, and in fixing the salt concentration by weight by, optionally, adding water thereto.