Abstract: An object of the present invention is to provide a copolymer polyamide which has excellent strength, high-temperature strength, low water absorbance, low blocking properties, releasability and plasticizing time stability, and a copolymer polyamide composition which has excellent vibration fatigue characteristics, surface appearance and continuous productivity. A copolymer polyamide of the present invention is obtained by polymerizing (a) at least one alicyclic dicarboxylic acid, (b) one diamine having 8 or more carbon atoms, and (c) at least one copolymer component selected from the group consisting of the following (c-1) to (c-3): a (c-1) dicarboxylic acid other than the alicyclic dicarboxylic acid; a (c-2) diamine having fewer carbon atoms than the (b) diamine; and a (c-3) lactam and/or aminocarboxylic acid, and the copolymer polyamide satisfies specific conditions.

Abstract: A polyamide composition containing a polyamide (A), 0.1 to 20% by mass of a metal hydroxide (C) and/or a metal oxide (D), and 0.1 to 20% by mass of a phosphorus-based compound (E).

Abstract: A polyamide comprising a unit containing at least one (a) alicyclic dicarboxylic acid and a unit containing a (b) diamine having 8 or more carbon atoms, wherein the polyamide satisfies the following conditions (1) and (2): (1) a sulfuric acid relative viscosity ?r at 25° C. is 2.3 or more; and (2) Mw (weight average molecular weight)/Mn (number average molecular weight) is 4.0 or less.

Abstract: It is an object of the present invention to provide a polyamide composition having excellent whiteness, reflow resistance, heat discoloration resistance, light discoloration resistance, and extrusion processability. A polyamide composition has: a polyamide (A) having a dicarboxylic acid unit (a) and a diamine unit (b); 20 to 70 mass % of titanium oxide (B); and 0.5 to 7.5 mass % of a phosphorus-based compound (C).

Abstract: The present invention relates to a polyamide obtainable by polymerizing an (a) dicarboxylic acid comprising at least 50 mol % of an alicyclic dicarboxylic acid and a (b) diamine comprising at least 50 mol % of a diamine having a substituent branched from a main chain.

Abstract: (Problems to be solved) Provision of a polyamide composition with good heat resistance, stability under heating, heat resistant color tone stability, reflow heat resistance properties and fogging properties. (Solution) A polyamide obtained by polymerizing (a) a dicarboxylic acid containing at least 50 mol % of an alicyclic dicarboxylic acid and (b) a diamine containing at least 50 mol % of a diamine having a pentamethylenediamine skeleton, wherein the polyamide has a cyclic amino end content of less than 30? equivalents/g.

Abstract: A polyamide comprising a unit containing at least one (a) alicyclic dicarboxylic acid and a unit containing a (b) diamine having 8 or more carbon atoms, wherein the polyamide satisfies the following conditions (1) and (2): (1) a sulfuric acid relative viscosity ?r at 25° C. is 2.3 or more; and (2) Mw (weight average molecular weight)/Mn (number average molecular weight) is 4.0 or less.

Abstract: [Problem to be Solved] To provide a polyamide having a high melting point, which has excellent strength, toughness, and stability under heating. [Solution] This polyamide is obtained by polymerizing an (a) dicarboxylic acid comprising at least 50 mol % of an alicyclic dicarboxylic acid and a (b) diamine comprising at least 50 mol % of a diamine having a pentamethylenediamine skeleton, wherein the polyamide has a cyclic amino end amount of 30 to 60? equivalents/g.

Abstract: (Problems to be solved) Provision of a polyamide composition with good heat resistance, stability under heating, heat resistant color tone stability, reflow heat resistance properties and fogging properties. (Solution) A polyamide obtained by polymerizing (a) a dicarboxylic acid containing at least 50 mol % of an alicyclic dicarboxylic acid and (b) a diamine containing at least 50 mol % of a diamine having a pentamethylenediamine skeleton, wherein the polyamide has a cyclic amino end content of less than 30? equivalents/g.

Abstract: The present invention relates to a polyamide obtainable by polymerizing an (a) dicarboxylic acid comprising at least 50 mol % of an alicyclic dicarboxylic acid and a (b) diamine comprising at least 50 mol % of a diamine having a substituent branched from a main chain.

Abstract: An object of the present invention is to provide a copolymer polyamide which has excellent strength, high-temperature strength, low water absorbance, low blocking properties, releasability and plasticizing time stability, and a copolymer polyamide composition which has excellent vibration fatigue characteristics, surface appearance and continuous productivity. A copolymer polyamide of the present invention is obtained by polymerizing (a) at least one alicyclic dicarboxylic acid, (b) one diamine having 8 or more carbon atoms, and (c) at least one copolymer component selected from the group consisting of the following (c-1) to (c-3): a (c-1) dicarboxylic acid other than the alicyclic dicarboxylic acid; a (c-2) diamine having fewer carbon atoms than the (b) diamine; and a (c-3) lactam and/or aminocarboxylic acid, and the copolymer polyamide satisfies specific conditions.

Abstract: The present invention relates to a polyamide obtainable by polymerizing an (a) dicarboxylic acid comprising at least 50 mol % of an alicyclic dicarboxylic acid and a (b) diamine comprising at least 50 mol % of a diamine having a substituent branched from a main chain.

Abstract: A method for producing an aqueous diamine dicarboxylic acid salt solution according to the present invention comprises a step of mixing a dicarboxylic acid diester and a diamine, wherein a mixing molar ratio of the diamine to the dicarboxylic acid diester (diamine/dicarboxylic acid diester) is 1.005 or more. In addition, a method for producing a polyamide according to the present invention comprises a step of mixing a dicarboxylic acid diester and a diamine and heating the formed aqueous diamine dicarboxylic acid salt solution to perform a polycondensation reaction of the diamine and a dicarboxylic acid, wherein a mixing molar ratio of the diamine to the dicarboxylic acid diester (diamine/dicarboxylic acid diester) is 1.005 or more.

Abstract: [Problem to be Solved] To provide a polyamide having a high melting point, which has excellent strength, toughness, and stability under heating. [Solution] This polyamide is obtained by polymerizing an (a) dicarboxylic acid comprising at least 50 mol % of an alicyclic dicarboxylic acid and a (b) diamine comprising at least 50 mol % of a diamine having a pentamethylenediamine skeleton, wherein the polyamide has a cyclic amino end amount of 30 to 60? equivalents/g.

Abstract: The present invention relates to a polyamide obtainable by polymerizing an (a) dicarboxylic acid comprising at least 50 mol % of an alicyclic dicarboxylic acid and a (b) diamine comprising at least 50 mol % of a diamine having a substituent branched from a main chain.

Abstract: Disclosed is an olefin polymerization catalyst comprising: a transition metal compound comprising one transition metal selected from the group consisting of Ti, Zr and Hf, and at least two ligands, wherein one ligand is a group having a cyclopentadienyl skeleton, and the remaining at least one ligand is a monovalent, bidentate, anionic chelating ligand having two coordinating atoms each coordinated to the transition metal, one of which atoms is selected from the group consisting of O, S, Se and Te, and the other of which atoms is selected from the group consisting of N, S, Se and Te, and wherein one of the remaining at least one ligand is optionally bonded to the group having a cyclopentadienyl skeleton through a bridging group. Also disclosed is a method for efficiently producing an olefin homopolymer or olefin copolymer by using this catalyst.