Provided are [1] a xylylenediamine composition containing xylylenediamine and a pyridine compound (A) having at least one substituent including an amino group, wherein the content of the pyridine compound (A) is 0.001 to 0.1 parts by mass based on 100 parts by mass of the xylylenediamine; and [2] a method for producing a polyamide resin including the steps of introducing a pyridine compound (A) having at least one substituent including an amino group, a diamine including xylylenediamine (but excluding a diamine corresponding to the above-mentioned pyridine compound (A)), and a dicarboxylic acid into a reaction system and performing a polycondensation reaction, wherein the amount of the pyridine compound (A) to be introduced is 0.001 to 0.1 parts by mass based on 100 parts by mass of xylylenediamine.

Provided are [1] a xylylenediamine composition containing xylylenediamine and a pyridine compound (A) having at least one substituent including an amino group, wherein the content of the pyridine compound (A) is 0.001 to 0.1 parts by mass based on 100 parts by mass of the xylylenediamine; and [2] a method for producing a polyamide resin including the steps of introducing a pyridine compound (A) having at least one substituent including an amino group, a diamine including xylylenediamine (but excluding a diamine corresponding to the above-mentioned pyridine compound (A)), and a dicarboxylic acid into a reaction system and performing a polycondensation reaction, wherein the amount of the pyridine compound (A) to be introduced is 0.001 to 0.1 parts by mass based on 100 parts by mass of xylylenediamine.

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.

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.

The present invention relates to a process for preparing a granular nylon salt material, wherein an aqueous mixture, comprising at least 65 wt. % of salt components, and at most 35 wt. % of an aqueous medium, the weight percentages (wt. %) being relative to the total weight of the aqueous mixture, is flashed from a pressure vessel via a flash valve into a flash chamber, thereby evaporating the aqueous medium in an amount sufficient to result in a residual moisture content of at most 7.5 wt. %, and forming a granular nylon salt material. The invention also relates to a process for preparing a nylon polymer, comprising direct solid state polymerization of the granular salt material prepared by flash granulation.

The present invention relates to a process for preparing a granular nylon salt material, wherein an aqueous mixture, comprising at least 65 wt. % of salt components, and at most 35 wt. % of an aqueous medium, the weight percentages (wt. %) being relative to the total weight of the aqueous mixture, is flashed from a pressure vessel via a flash valve into a flash chamber, thereby evaporating the aqueous medium in an amount sufficient to result in a residual moisture content of at most 7.5 wt. %, and forming a granular nylon salt material. The invention also relates to a process for preparing a nylon polymer, comprising direct solid state polymerization of the granular salt material prepared by flash granulation.

The present disclosure relates to a method for the production of polyamides having the benefit of simpler process control, lower thermal degradation and greater compositional flexibility. More particularly, it relates to processes of converting salts of diamines and dicarboxylic acids to polyamides in the solid state without a melt phase, by fluidizing solid diacid in a fluidizing gas.

A base polyamide composition comprising a nylon mixture having caprolactam units from 1 wppb to 50 wppm catalyst composition; and greater than 0.75 wt % residual caprolactam, wherein the base polyamide composition has a delta end group level ranging from 30 μeq/gram to 90 μeq/gram.

The disclosure relates to a synthesis method of long carbon chain semi-aromatic nylon. The synthesis method comprises the following steps: mixing a wet powdery nylon salt, an antioxidant, a catalyst, a surfactant and pellets, and carrying out a one-step solid state polymerization under dynamic mixing to obtain a powdery nylon; under dynamic mixing, enabling the pellets to promote the stirring and mixing of the material and reducing material adhesion to the wall; the one-step solid state polymerization comprises a pre-solid state polymerization and a post-solid state polymerization; in the pre-solid state polymerization, ensuring the nylon salt and the prepolymer not to be molten; in the post-solid state polymerization, gradually reducing the system pressure to vacuum, and keeping the system pressure in vacuum state for at least 1 hour; the temperature of the post-solid state polymerization is not lower than the termination temperature of the pre-solid state polymerization.

The disclosure relates to a synthesis method of long carbon chain semi-aromatic nylon. The synthesis method comprises the following steps: mixing a wet powdery nylon salt, an antioxidant, a catalyst, a surfactant and pellets, and carrying out a one-step solid state polymerization under dynamic mixing to obtain a powdery nylon; under dynamic mixing, enabling the pellets to promote the stirring and mixing of the material and reducing material adhesion to the wall; the one-step solid state polymerization comprises a pre-solid state polymerization and a post-solid state polymerization; in the pre-solid state polymerization, ensuring the nylon salt and the prepolymer not to be molten; in the post-solid state polymerization, gradually reducing the system pressure to vacuum, and keeping the system pressure in vacuum state for at least 1 hour; the temperature of the post-solid state polymerization is not lower than the termination temperature of the pre-solid state polymerization.