US Patent 7637680 Coating tool

A coating tool that includes an ink containment tube, an oily ink and a backflow inhibiting material. The ink is in contact with the inhibiting material. The ink containment tube has a boundary which is in contact with the oily ink and the backflow inhibiting material. The boundary contains polyvinyl alcohol and fluorine-based surfactants, the oily ink contains a colorant, a resin, an organic solvent, and a gelling agent, and the backflow inhibiting material consists of base material components and a gelling agent which contains polyacrylic acid, the polyacrylic acid being present in an amount of 0.1 to 3 wt % with respect to the total amount of said backflow inhibiting material.