Double container and exterior sleeve used in double container

An external sleeve covering a barrel portion of a paper inner container having a cylindrical barrel portion formed to have a curled portion on an upper circumferential edge thereof, and a bottom portion provided on a lower end of the barrel portion so as to close a lower face thereof, the exterior sleeve forming a thermal insulating space between itself and an outer surface of the barrel portion;

• wherein the circumferential edge portion of the upper end portion of the exterior sleeve enters a gap on the inner side of the curled portion of the circumferential edge portion at the upper end of the inner container, and the thermal insulating space between the exterior sleeve and the inner container expands as the lower end is approached;
• wherein the exterior sleeve has a height that is smaller than that of the inner container and covers the inner container over an area extending partway from the curled portion of the inner container toward a lower edge of the inner container;
• and
• wherein the inner surface of the exterior sleeve is provided over the entire circumference thereof with a plurality of elongated projections, which consist of thermoplastic resin, arranged in a row and spaced apart in a circumferential direction, and the projections extend in an elongated fashion circumferentially and each has a projection amount of 1.0 to 2.0 mm,
• and the row of the plurality of elongated projections is situated at a location that is above half of the height of the inner container.