| 摘要 |
PURPOSE: To easily manufacture a safe road reflecting mirror hardly freezing and rusting by spirally arranging a heat reserving material enclosing body in which sodium acetate water solution is filled in a flexible tube, on the back of a specular plate. CONSTITUTION: Sodium acetate water solution as heat reserving material is received in a tubular container made of flexible resin, and the end part 2' is blockaded so as to form a heat reserving material enclosing body 2. The enclosing body 2 is uniformly spirally arranged on the back of a specular plate 1 while adjusting the space so as to meet the size of the specular plate 1. In addition, a back plate 4 is provided along the back side of the enclosing body 2 through a heat insulating material 3 or a plane-like heater connecting to a solar battery, and hence a road reflecting mirror is formed. The sodium acetate water solution maintains liquid phase in the wide range below the freezing point, has the sensible heat reserving action similar to water, hardly rusts the specular plate 1 or the back plate 4 even if it leaks out from the enclosing body 2, and hence safety is improved. |
