Abstract: Provided are a novel polyamide resin having a high melting point, and a composition and a molded article, for which the novel polyamide resin is used. A polyamide resin including a constituent unit derived from a diamine and a constituent unit derived from a dicarboxylic acid, where 70 mol % or more of the constituent unit derived from the diamine is derived from a xylylenediamine; and 70 mol % or more of the constituent unit derived from the dicarboxylic acid is derived from a phenylenediacetic acid; and where X+(Y/3) is 68 or more, when X mol % is defined as a proportion of a constituent unit derived from 1,4-phenylenediacetic acid in the constituent unit derived from the dicarboxylic acid, and Y mol % is defined as a proportion of a constituent unit derived from p-xylylenediamine in the constituent unit derived from the diamine.

Abstract: The polyamide pellet of the present invention includes a polyamide including diamine units and dicarboxylic acid units, 50% by mole or more of the diamine units being derived from m-xylylenediamine, wherein a spherulite density of a skin portion of the pellet is 40,000 to 250,000/mm2.

Abstract: Provided is a method for producing a polyamide resin including reacting a dicarboxylic acid component containing sebacic acid in an amount of 50 mol % or more and a diamine component containing xylylenediamine in an amount of 70 mol % or more, wherein the total content of the specific compounds in the sebacic acid is 100 ppm by mass or less.

Abstract: A method for producing a polyamide, comprising performing melt polycondensation of a diamine component comprising xylylenediamine in an amount of 70 mol % or more and a dicarboxylic acid component comprising a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms in an amount of 70 mol % or more in the presence of a phosphorus atom-containing compound (A), wherein the decomposition temperature of the phosphorus atom-containing compound (A) is not lower than the melting point of the polyamide, and an aqueous solution of the phosphorus atom-containing compound (A) and the diamine component are added to the dicarboxylic acid component being in a molten state to perform the melt polycondensation.

Abstract: Provided are [1] a xylylenediamine composition containing xylylenediamine and a 5-membered or 6-membered heterocyclic compound (A) having at least one nitrogen-containing substituent and having two nitrogen atoms as atoms constituting a ring, wherein the content of the heterocyclic compound (A) is 0.001 to 0.02 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 5-membered or 6-membered heterocyclic compound (A) having at least one nitrogen-containing substituent and having two nitrogen atoms as atoms constituting a ring, a diamine including xylylenediamine (but excluding a diamine corresponding to the above-mentioned heterocyclic compound (A)), and a dicarboxylic acid into a reaction system and performing a polycondensation reaction, wherein the amount of the heterocyclic compound (A) to be introduced is 0.001 to 0.02 parts by mass based on 100 parts by mass of xylylenediamine.

Abstract: Provided is a method for producing a polyamide resin including reacting a dicarboxylic acid component containing sebacic acid in an amount of 50 mol % or more and a diamine component containing xylylenediamine in an amount of 70 mol % or more, wherein the total content of the specific compounds in the sebacic acid is 100 ppm by mass or less.

Abstract: Provided are [1] a xylylenediamine composition containing xylylenediamine and 1,2-ditolylethane wherein the content of 1,2-ditolylethane is 0.001 to 0.02 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 diamine containing xylylenediamine, a dicarboxylic acid, and 1,2-ditolylethane into a reaction system and performing polycondensation reaction, wherein the amount of the 1,2-ditolylethane to be introduced is 0.001 to 0.02 parts by mass based on 100 parts by mass of the xylylenediamine.

Abstract: 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.

Abstract: The polyamide pellet of the present invention includes a polyamide including diamine units and dicarboxylic acid units, 50% by mole or more of the diamine units being derived from m-xylylenediamine, wherein a spherulite density of a skin portion of the pellet is 40,000 to 250,000/mm2.

Abstract: Provided are [1] a xylylenediamine composition containing xylylenediamine and a compound represented by the following general formula (1), wherein the content of the compound represented by the general formula (1) is 0.001 to 0.1 parts by mass based on 100 parts by mass of the xylylenediamine; and a method for producing a polyamide resin including the steps of introducing a compound represented by the following general formula (1), a diamine including xylylenediamine (but excluding the compound represented by the general formula (1)), and a dicarboxylic acid into a reaction system and performing a polycondensation reaction, wherein the amount of the compound represented by the general formula (1) to be introduced is 0.001 to 0.1 parts by mass based on 100 parts by mass of the xylylenediamine, where, in the general formula (1), n and m each independently represent an integer of 0 to 6, excluding the case where n and m are both 1.

Abstract: A method for producing a polyamide, comprising performing melt polycondensation of a diamine component comprising xylylenediamine in an amount of 70 mol % or more and a dicarboxylic acid component comprising a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms in an amount of 70 mol % or more in the presence of a phosphorus atom-containing compound (A), wherein the decomposition temperature of the phosphorus atom-containing compound (A) is not lower than the melting point of the polyamide, and an aqueous solution of the phosphorus atom-containing compound (A) and the diamine component are added to the dicarboxylic acid component being in a molten state to perform the melt polycondensation.

Abstract: Provided are a xylylenediamine composition containing xylylenediamine and bis(methylbenzyl)amine, a content of the bis(methylbenzyl)amine being 0.0005 to 0.1 parts by mass based on 100 parts by mass of the xylylenediamine; and a method for producing a polyamide resin including the steps of introducing a diamine containing xylylenediamine, a dicarboxylic acid, and bis(methylbenzyl)amine in an amount of 0.0005 to 0.1 parts by mass based on 100 parts by mass of the xylylenediamine into a reaction system and performing a polycondensation reaction.

Abstract: 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.

Abstract: Provided are [1] a xylylenediamine composition containing xylylenediamine and a 5-membered or 6-membered heterocyclic compound (A) having at least one nitrogen-containing substituent and having two nitrogen atoms as atoms constituting a ring, wherein the content of the heterocyclic compound (A) is 0.001 to 0.02 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 5-membered or 6-membered heterocyclic compound (A) having at least one nitrogen-containing substituent and having two nitrogen atoms as atoms constituting a ring, a diamine including xylylenediamine (but excluding a diamine corresponding to the above-mentioned heterocyclic compound (A)), and a dicarboxylic acid into a reaction system and performing a polycondensation reaction, wherein the amount of the heterocyclic compound (A) to be introduced is 0.001 to 0.02 parts by mass based on 100 parts by mass of xylylenediamine.

Abstract: Provided are [1] a xylylenediamine composition containing xylylenediamine and a compound represented by the following general formula (1), wherein the content of the compound represented by the general formula (1) is 0.001 to 0.1 parts by mass based on 100 parts by mass of the xylylenediamine; and a method for producing a polyamide resin including the steps of introducing a compound represented by the following general formula (1), a diamine including xylylenediamine (but excluding the compound represented by the general formula (1)), and a dicarboxylic acid into a reaction system and performing a polycondensation reaction, wherein the amount of the compound represented by the general formula (1) to be introduced is 0.001 to 0.1 parts by mass based on 100 parts by mass of the xylylenediamine, where, in the general formula (1), n and m each independently represent an integer of 0 to 6, excluding the case where n and m are both 1.

Abstract: Provided are [1] a xylylenediamine composition containing xylylenediamine and 1,2-ditolylethane wherein the content of 1,2-ditolylethane is 0.001 to 0.02 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 diamine containing xylylenediamine, a dicarboxylic acid, and 1,2-ditolylethane into a reaction system and performing polycondensation reaction, wherein the amount of the 1,2-ditolylethane to be introduced is 0.001 to 0.02 parts by mass based on 100 parts by mass of the xylylenediamine.

Abstract: The present invention is directed to a process for producing a polyamide, which process includes directly melt-polymerizing a diamine component including 70 mol % or more of p-xylylenediamine and a dicarboxylic acid component including 70 mol % or more of a C6 to C18 aliphatic dicarboxylic acid, in the absence of solvent in a batch-type reactor equipped with a stirring blade, the process including: (1) reacting the diamine component with the dicarboxylic acid component under a pressure condition of 0.2 to 0.5 MPa (Abs); (2) maintaining a vapor phase section of a reaction tank of the reactor at 200° C. or higher during reaction; (3) stirring the contents of the reaction tank, from the start of adding the diamine component until after completion of the addition and before the start of pressure falling, such that the stirring-related Froude number represented by a specific formula is adjusted to 0.0002 to 0.

Abstract: Provided are a xylylenediamine composition containing xylylenediamine and bis(methylbenzyl)amine, a content of the bis(methylbenzyl)amine being 0.0005 to 0.1 parts by mass based on 100 parts by mass of the xylylenediamine; and a method for producing a polyamide resin including the steps of introducing a diamine containing xylylenediamine, a dicarboxylic acid, and bis(methylbenzyl)amine in an amount of 0.0005 to 0.1 parts by mass based on 100 parts by mass of the xylylenediamine into a reaction system and performing a polycondensation reaction.

Abstract: The invention is a method for producing a polyamide having a melting point of 255° C. or higher through polycondensation of a mixed xylylenediamine containing paraxylylenediamine as a diamine component and a dicarboxylic acid component in a batch reactor, wherein when the diamine component is dropwise added to the dicarboxylic acid component kept in a melt state by heating it to a temperature not lower than a melting point thereof under a pressure of 0.1 MPaG or more with keeping the melt state of a reaction mixture, a temperature of the reaction mixture is maintained at 255° C. or lower until a molar ratio (diamine component/dicarboxylic acid component) of the reaction mixture reaches 0.8, and the temperature of the reaction mixture at the end of the dropwise addition is controlled to be not lower than the melting point of the polyamide. The method enables production of a polyamide having an improved hue and being advantageous with respect to quality.

Abstract: The present invention is directed to a process for producing a polyamide, which process includes directly melt-polymerizing a diamine component including 70 mol % or more of p-xylylenediamine and a dicarboxylic acid component including 70 mol % or more of a C6 to C18 aliphatic dicarboxylic acid, in the absence of solvent in a batch-type reactor equipped with a stirring blade, the process including: (1) reacting the diamine component with the dicarboxylic acid component under a pressure condition of 0.2 to 0.5 MPa (Abs); (2) maintaining a vapor phase section of a reaction tank of the reactor at 200° C. or higher during reaction; (3) stirring the contents of the reaction tank, from the start of adding the diamine component until after completion of the addition and before the start of pressure falling, such that the stirring-related Froude number represented by a specific formula is adjusted to 0.0002 to 0.