Polyamide block copolymer, polyamide block copolymer composition, and molded article

A polyamide block copolymer having a melting point of 230° C. or higher, which comprises a polymer block (A) comprising a constitutional unit derived from a polyamide in an amount of 50 mol % or more and a polymer block (B) having a glass transition temperature of 20° C. or lower,

• wherein, in a temperature-loss tangent (tan δ) curve obtained when a test piece having a length of 20 mm, a width of 5 mm, and a thickness of 100 μm is measured using a viscoelasticity measuring apparatus in a temperature range of −100° C. to 330° C. at a chuck-to-chuck distance of 10 mm, a frequency of 1 Hz, and a temperature raising rate of 3° C./min, a temperature T0[° C.] at which a loss tangent in the temperature range of −100° C. to 160° C. becomes a maximum value tan δ (max) satisfies the following formula (1):
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• a first temperature T1[° C.] which is lower than the temperature T0 and at which the loss tangent shows a half value of the maximum value tan δ (max) and a second temperature T2[° C.] which is higher than the temperature T0 and at which the loss tangent shows a half value of the maximum value tan δ (max) satisfy a relationship of the following formula (2):
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