Abstract: A core material has a core 12; a solder layer 16 made of a (Sn—Bi)-based solder alloy provided on an outer side of the core 12; and a Sn layer 20 provided on an outer side of the solder layer 16. The core contains metal or a resin. When a concentration ratio of Bi contained in the solder layer 16 is a concentration ratio (%)=a measured value of Bi (% by mass)/a target Bi content (% by mass), or a concentration ratio (%)=an average value of measured values of Bi (% by mass)/a target Bi content (% by mass), the concentration ratio is 91.4% to 106.7%. The thickness of the Sn layer 20 is 0.215% or more and 36% or less of the thickness of the solder layer 16.

Abstract: A membrane electrode assembly for a polymer electrolyte fuel cell has superior power generation characteristics under low humidity conditions and superior starting characteristics under low temperature conditions. In the membrane electrode assembly for a polymer electrolyte fuel cell in which a polymer electrolyte membrane is disposed between a pair of electrodes containing a catalyst, the polymer electrolyte membrane has a polymer segment A having an ion conductive component and a polymer segment B not having an ion conductive component. Furthermore, in the case in which the polymer electrolyte membrane is immersed in water at 90° C. for 30 minutes, absorbed water which exhibits a thawing temperature of from ?30 to 0° C. is in a range from 0.01 to 3.0 g per 1 g of the polymer.

Abstract: A membrane electrode assembly for a polymer electrolyte fuel cell has superior power generation characteristics under low humidity conditions and superior starting characteristics under low temperature conditions. In the membrane electrode assembly for a polymer electrolyte fuel cell in which a polymer electrolyte membrane is disposed between a pair of electrodes containing a catalyst, the polymer electrolyte membrane has a polymer segment A having an ion conductive component and a polymer segment B not having an ion conductive component. Furthermore, in the case in which the polymer electrolyte membrane is immersed in water at 90° C. for 30 minutes, absorbed water which exhibits a thawing temperature of from ?30 to 0° C. is in a range from 0.01 to 3.0 g per 1 g of the polymer.

Abstract: A membrane electrode assembly for a polymer electrolyte fuel cell has superior power generation characteristics under low humidity conditions and superior starting characteristics under low temperature conditions. In the membrane electrode assembly for a polymer electrolyte fuel cell in which a polymer electrolyte membrane is disposed between a pair of electrodes containing a catalyst, the polymer electrolyte membrane has a polymer segment A having an ion conductive component and a polymer segment B not having an ion conductive component. Furthermore, in the case in which the polymer electrolyte membrane is immersed in water at 90° C. for 30 minutes, absorbed water which exhibits a thawing temperature of from ?30 to 0° C. is in a range from 0.01 to 3.0 g per 1 g of the polymer.

Abstract: A membrane electrode assembly for a polymer electrolyte fuel cell has superior power generation characteristics under low humidity conditions and superior starting characteristics under low temperature conditions. In the membrane electrode assembly for a polymer electrolyte fuel cell in which a polymer electrolyte membrane is disposed between a pair of electrodes containing a catalyst, the polymer electrolyte membrane has a polymer segment A having an ion conductive component and a polymer segment B not having an ion conductive component. Furthermore, in the case in which the polymer electrolyte membrane is immersed in water at 90° C. for 30 minutes, absorbed water which exhibits a thawing temperature of from ?30 to 0° C. is in a range from 0.01 to 3.0 g per 1 g of the polymer.