The ornamental design for leakproof carton, as shown and described.
FIG. 1 is a top plan view of the leakproof carton showing the design unfolded. The bottom plan view is a mirror image thereof.
FIG. 2 is a perspective view of the leakproof carton showing the assembled flap ready for assembly upon the carton. The opposite sides of the flap and the carton are mirror images thereof.
FIG. 3 is a perspective view of the leakproof carton assembled together. The opposite sides of the flap and the carton are mirror images thereof.
FIG. 4 is a perspective view of the leakproof carton shown in FIG. 1 showing the design folded. The opposite side is a mirror image thereof.
FIG. 5 is a side view of the leakproof carton shown in FIG. 1. The opposite side is a mirror image thereof; and,
FIG. 6 is an end view of the leakproof carton shown in FIG. 1. The opposite side is a mirror image thereof.
The fold lines shown in FIGS. 1, 2, and 3 by broken lines are fold lines and form part of the claim.
The broken lines in the figures represent unclaimed environmental subject matter.