| 摘要 |
PURPOSE: To obtain a thermally recoverable article changed in its shape when the article is recovered by using a conductive polymer material wherein resistivity measured at least at a part of an expansion range in a current flow direction is reduced at a time of expansion. CONSTITUTION: In a tubular article having end parts 3, 4 and an intermediate main body part 5, the end parts 3, 4 are respectively expanded by Y1% and Y2% and the main body part is expanded by X%. The wall thicknesses of an article at the ends 3, 4 are larger than the wall thickness of the main body 5 before expansion and substantially same after expansion. The article is composed of a conductive polymer material having heat recovery in an expanded state and showing a PTC ratio of about 5. When the material is expanded to X% or more, for example, Y1 or Y2%, resistivity is reduced. When the electrodes 9, 10 provided to the ends 3, 4 are connected to separate power supplies, the resistivity of the end parts 3, 4 is smaller than that of the main body 5 and a current flows to the end parts to heat and recover the article. When recovery is generated, the electrodes of the end 3 approach mutually and a wall thickness is increased. |
