PROBLEM TO BE SOLVED: To improve heat insulation property by arranging an intermediate layer between a plurality of transparent synthetic resin plates.SOLUTION: Dry air is sealed in an intermediate layer and heat insulation effect is improved by transparent synthetic resin having heat conductivity approximately one fourth of that of the glass.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2020,JPO&INPIT【課題】 複数枚の透明な合成樹脂板で作り、その間に中間層を設けて断熱性能を向上した。【解決手段】中間層に乾燥空気を封入し、熱伝導率がガラスの約1/4の透明な合成樹脂で断熱効果をあげた。【選択図】図1