Resin member and sheet using same, method for producing resin member, and heat storage material and heat control sheet using same

A resin member comprising:

• a copolymer of ethylene and an olefin having 3 or more carbon atoms;
• a straight-chain saturated hydrocarbon compound;
• and
• at least one selected from the group consisting of a carboxylic acid and a carboxylic acid metal salt, wherein the metal constituting the carboxylic acid metal salt is aluminum,
• wherein the resin member is in the form of a sheet, and
• wherein a content of the copolymer of ethylene and an olefin having 3 or more carbon atoms is 5% by mass or more and 50% by mass or less based on the total amount of the resin member, a content of the straight-chain saturated hydrocarbon compound is 40% by mass or more and 90% by mass or less based on the total amount of the resin member, and a content of the at least one selected from the group consisting of a carboxylic acid and a carboxylic acid metal salt is 3% by mass or more and 10% by mass or less based on the total amount of the resin member.