Abstract: The present invention relates to a polyamide that is a polyamide (A) having a dicarboxylic acid unit and a diamine unit, wherein more than 40 mol % and 100 mol % or less of the dicarboxylic acid unit is a naphthalenedicarboxylic acid unit, and 60 mol % or more and 100 mol % or less of the diamine unit is a branched aliphatic diamine unit and a linear aliphatic diamine unit of an arbitrary structural unit, and a proportion of the branched aliphatic diamine unit relative to the total 100 mol % of the branched aliphatic diamine unit and the linear aliphatic diamine unit is 60 mol % or more; and a polyamide composition containing the polyamide.

Abstract: There is provided a polyamide composition for an LED reflection plate, including a polyamide (A), a titanium oxide (B), a magnesium oxide (C), a phenolic antioxidant (D), and a phosphorus-containing antioxidant (E), wherein the polyamide (A) is a polyamide having a dicarboxylic acid unit comprising 50% by mol or more of terephthalic acid unit and a diamine unit and having a melting point of 280° C. or higher; the phenolic antioxidant (D) does not have 4 or more phenol structures in its molecule; wherein the content of the titanium oxide (B) is 10 to 100 parts by mass, the content of the magnesium oxide (C) is 0.50 to 15.0 parts by mass, and the content of the phenolic antioxidant (D) is 0.10 to 0.80 part by mass, with respect to 100 parts by mass of the polyamide (A); and the content of the phosphorus-containing antioxidant (E) satisfies the following expression (I): 0.25?mass ratio [(D)component/(E)component]?3.0??(I).

Abstract: There is provided a polyamide composition for an LED reflection plate, including a polyamide (A), a titanium oxide (B), a magnesium oxide (C), a phenolic antioxidant (D), and a phosphorus-containing antioxidant (E), wherein the polyamide (A) is a polyamide having a dicarboxylic acid unit comprising 50% by mol or more of terephthalic acid unit and a diamine unit and having a melting point of 280° C. or higher; the phenolic antioxidant (D) does not have 4 or more phenol structures in its molecule; wherein the content of the titanium oxide (B) is 10 to 100 parts by mass, the content of the magnesium oxide (C) is 0.50 to 15.0 parts by mass, and the content of the phenolic antioxidant (D) is 0.10 to 0.80 part by mass, with respect to 100 parts by mass of the polyamide (A); and the content of the phosphorus-containing antioxidant (E) satisfies the following expression (I): 0.25?mass ratio [(D)component/(E)component]?3.0??(I).

Abstract: The present invention relates to a polyester composition for an LED reflection plate containing a polyester (A), a titanium oxide (B), a phenolic antioxidant (C), and a phosphorus-based antioxidant (D), wherein the polyester (A) is a polyester having a structural unit derived from a dicarboxylic acid including 50 mol % or more of terephthalic acid and a structural unit derived from a diol including 50 mol % or more of 1,4-cyclohexanedimethanol; the phosphorus-based antioxidant (D) contains three or more groups represented by the formula (1) in a molecule thereof; the content of the titanium oxide (B) is 20 to 90 parts by mass, and the content of the phenolic antioxidant (C) is 0.1 to 0.8 parts by mass, on the basis of 100 parts by mass of the polyester (A); and the content of the phosphorus-based antioxidant (D) satisfies the following equation (I); an LED reflection plate composed of the foregoing composition; and a light-emitting device including the foregoing reflection plate. 0.

Abstract: The present invention is a polyamide resin composition containing a polyamide resin (A) that contains from 95 to 99.95% by mass of a polyamide (a-1) having a number-average molecular weight of 2000 or more and from 0.05 to 5% by mass of a polyamide oligomer (a-2) having a number-average molecular weight of from 500 to less than 2000, in which at least 25 mol % of all the monomer units constituting the polyamide (a-1) and the polyamide oligomer (a-2) are structural units derived from a specific alicyclic monomer and the content ratio of the trans isomer structural units derived from the alicyclic monomer is from 50 to 85 mol %, and containing an inorganic filler (B). The polyamide resin composition is excellent in heat resistance, low water absorption, high-temperature rigidity and flowability, and exhibits the effects of securing sufficient crystallization even when molded in a mold at 80° C. and causing minimal mold deposit during production.

Abstract: The present invention is a polyamide resin composition containing a polyamide resin (A) that contains from 95 to 99.95% by mass of a polyamide (a-1) having a number-average molecular weight of 2000 or more and from 0.05 to 5% by mass of a polyamide oligomer (a-2) having a number-average molecular weight of from 500 to less than 2000, in which at least 25 mol % of all the monomer units constituting the polyamide (a-1) and the polyamide oligomer (a-2) are structural units derived from a specific alicyclic monomer and the content ratio of the trans isomer structural units derived from the alicyclic monomer is from 50 to 85 mol %, and containing an inorganic filler (B). The polyamide resin composition is excellent in heat resistance, low water absorption, high-temperature rigidity and flowability, and exhibits the effects of securing sufficient crystallization even when molded in a mold at 80° C. and causing minimal mold deposit during production.